GBATEK
Gameboy Advance / Nintendo DS / DSi - Technical Info - Extracted from no$gba version 3.03
About this Document

GBA Reference
Overview GBA Technical Data GBA Memory Map GBA I/O Map Hardware Programming GBA LCD Video Controller GBA Sound Controller GBA Timers GBA DMA Transfers GBA Communication Ports GBA Keypad Input GBA Interrupt Control GBA System Control GBA Cartridges GBA Unpredictable Things Other ARM CPU Reference BIOS Functions External Connectors |
NDS Reference
Overview DS Technical Data DS I/O Maps DS Memory Maps Hardware Programming DS Memory Control DS Video DS 3D Video DS Sound DS System and Built-in Peripherals DS Cartridges, Encryption, Firmware DS Xboo DS Wireless Communications Other BIOS Functions ARM CPU Reference External Connectors
3DS Reference
3DS Reference (under construction) |
DSi Reference
DSi Basic Differences to NDS New Hardware Features DSi I/O Map DSi Control Registers (SCFG) DSi XpertTeak (DSP) DSi New Shared WRAM DSi New DMA (NDMA) DSi Microphone and SoundExt DSi Advanced Encryption Standard (AES) DSi Cartridge Header DSi Touchscreen/Sound Controller DSi I2C Bus DSi Cameras DSi SD/MMC Protocol and I/O Ports DSi SD/MMC Filesystem DSi Atheros Wifi SDIO Interface DSi Atheros Wifi Internal Hardware DSi GPIO Registers DSi Console IDs DSi Unknown Registers DSi Notes DSi Exploits DSi Regions

CPU Reference
General ARM7TDMI Information ARM CPU Overview ARM CPU Register Set ARM CPU Flags & Condition Field (cond) ARM CPU 26bit Memory Interface ARM CPU Exceptions ARM CPU Memory Alignments Further Information ARM Pseudo Instructions and Directives ARM CP15 System Control Coprocessor ARM CPU Instruction Cycle Times ARM CPU Versions ARM CPU Data Sheet |
CPU 32bit ARM Mode
ARM 32bit Opcodes (ARM Code) ARM Instruction Summary ARM Branch and Branch with Link (B, BL, BX, BLX, SWI, BKPT) ARM Data Processing (ALU) ARM Multiply and Multiply-Accumulate (MUL, MLA) ARM Special ARM9 Instructions (CLZ, QADD/QSUB) ARM PSR Transfer (MRS, MSR) ARM Memory: Single Data Transfer (LDR, STR, PLD) ARM Memory: Halfword, Doubleword, and Signed Data Transfer ARM Memory: Block Data Transfer (LDM, STM) ARM Memory: Single Data Swap (SWP) ARM Coprocessor (MRC/MCR, LDC/STC, CDP, MCRR/MRRC) |
CPU 16bit THUMB Mode
ARM 16bit Opcodes (THUMB Code) When operating in THUMB state, cut-down 16bit opcodes are used. THUMB is supported on T-variants of ARMv4 and up, ie. ARMv4T, ARMv5T, etc. THUMB Instruction Summary THUMB Register Operations (ALU, BX) THUMB Memory Load/Store (LDR/STR) THUMB Memory Addressing (ADD PC/SP) THUMB Memory Multiple Load/Store (PUSH/POP and LDM/STM) THUMB Jumps and Calls

GBA Reference

Overview
GBA Technical Data
GBA Memory Map
GBA I/O Map
Hardware Programming
GBA LCD Video Controller
GBA Sound Controller
GBA Timers
GBA DMA Transfers
GBA Communication Ports
GBA Keypad Input
GBA Interrupt Control
GBA System Control
GBA Cartridges
GBA Unpredictable Things
Other
ARM CPU Reference
BIOS Functions
External Connectors

GBA Technical Data

CPU Modes

      ARM Mode     ARM7TDMI 32bit RISC CPU, 16.78MHz, 32bit opcodes (GBA)
      THUMB Mode   ARM7TDMI 32bit RISC CPU, 16.78MHz, 16bit opcodes (GBA)
      CGB Mode     Z80/8080-style 8bit CPU, 4.2MHz or 8.4MHz  (CGB compatibility)
      DMG Mode     Z80/8080-style 8bit CPU, 4.2MHz (monochrome gameboy compatib.)

Internal Memory

      BIOS ROM     16 KBytes
      Work RAM     288 KBytes (Fast 32K on-chip, plus Slow 256K on-board)
      VRAM         96 KBytes
      OAM          1 KByte (128 OBJs 3x16bit, 32 OBJ-Rotation/Scalings 4x16bit)
      Palette RAM  1 KByte (256 BG colors, 256 OBJ colors)

Video

      Display      240x160 pixels (2.9 inch TFT color LCD display)
      BG layers    4 background layers
      BG types     Tile/map based, or Bitmap based
      BG colors    256 colors, or 16 colors/16 palettes, or 32768 colors
      OBJ colors   256 colors, or 16 colors/16 palettes
      OBJ size     12 types (in range 8x8 up to 64x64 dots)
      OBJs/Screen  max. 128 OBJs of any size (up to 64x64 dots each)
      OBJs/Line    max. 128 OBJs of 8x8 dots size (under best circumstances)
      Priorities   OBJ/OBJ: 0-127, OBJ/BG: 0-3, BG/BG: 0-3
      Effects      Rotation/Scaling, alpha blending, fade-in/out, mosaic, window
      Backlight    GBA SP only (optionally by light on/off toggle button)

Sound

      Analogue     4 channel CGB compatible (3x square wave, 1x noise)
      Digital      2 DMA sound channels
      Output       Built-in speaker (mono), or headphones socket (stereo)

Controls

      Gamepad      4 Direction Keys, 6 Buttons

Communication Ports

      Serial Port  Various transfer modes, 4-Player Link, Single Game Pak play

External Memory

      GBA Game Pak max. 32MB ROM or flash ROM + max 64K SRAM
      CGB Game Pak max. 32KB ROM + 8KB SRAM (more memory requires banking)

Case Dimensions

      Size (mm)    GBA: 145x81x25 - GBA SP: 82x82x24 (closed), 155x82x24 (stretch)

Power Supply

      Battery GBA  GBA: 2x1.5V DC (AA), Life-time approx. 15 hours
      Battery SP   GBA SP: Built-in rechargeable Lithium ion battery, 3.7V 600mAh
      External     GBA: 3.3V DC 350mA - GBA SP: 5.2V DC 320mA

     ----------------------------------------------------------------------------

Original Gameboy Advance (GBA)

            ____._____________...___.____
       ____/    :  CARTRIDGE  SIO   :    \____
      | L       _____________________  LED  R |
      |        |                     |        |
      |  _||_  |   2.9" TFT SCREEN   |    (A) |
      | |_  _| | 240x160pix  61x40mm | (B)    |
      |   ||   |    NO BACKLIGHT     |  ::::  |
      |        |                     | SPEAKR |
      | STRT() |_____________________|  ::::  |
      | SLCT()     GAME BOY ADVANCE    VOLUME |
      |____  OFF-ON  BATTERY 2xAA PHONES  _==_|
           \__.##.__________________,,___/

GBA SP (GBA SP)

       _______________________                                 _
      | _____________________ |                               / /
      ||                     ||                              / /
      ||   2.9" TFT SCREEN   ||                             / /
      || 240x160pix  61x40mm ||                            / /
      ||   WITH BACKLIGHT    ||                           / /
      ||                     ||     GBA SP SIDE VIEWS    / /
      ||_____________________||                         / /
      |  GAME BOY ADVANCE SP  |   _____________________(_)
      |_______________________|  |. . . . . . . .'.'.   _|
      |_|________|________|_|_|  |_CARTRIDGE_:_BATT._:_|_| <-- EXT1/EXT2
      |L    EXT1     EXT2    R|
      |          (*)      LEDSo   _____________________ _
      (VOL_||_           (A)  o  |_____________________(_)
      |  |_  _| ,,,,,(B)      |  |. . . . . . . .'.'.   _|
      |    ||   ;SPK;         |  |_CARTRIDGE_:_BATT._:_|_| <-- EXT1/EXT2
      |         '''''      ON #                         _ _____________________
      |       SLCT STRT    OFF#   _____________________(_)_____________________|
      | CART.  ()   ()        |  |. . . . . . . .'.'.   _|
      |_:___________________:_|  |_CARTRIDGE_:_BATT._:_|_| <-- EXT1/EXT2

Gameboy Micro (GBA Micro)

          ________________SIO_______________
         | L      __________________      R |
         |       |     GBA-MICRO    |       |
         | _||_  |  2.0" TFT SCREEN |    (A)| +
         ||_  _| |240x160pix 42x28mm| (B)   |VOL
         |  ||   |     BACKLIGHT    |       | -
         |       |__________________|  ...  |
         |___________SELECT__START__________|
           PWR   <--- CARTRIDGE SLOT ---> PHONES

Nintendo DS (NDS)

         _____________________________________
        |        _____________________        |
        |       |                     |       |
        |       |    3" TFT SCREEN    |       |
        |       | 256x192pix  61x46mm |       |
        |       |      BACKLIGHT      |       |
        | ::::: |    Original NDS     | ::::: |
        | ::::: |_____________________| ::::: |
       _|        _          ______   _        |_  <-- gap between screens: 22mm
      |L|_______| |________|      |_| |_______|R|     (equivalent to 90 pixels)
      |_______   _____________________   _______|
      |  PWR  | |                     | |SEL STA|
      |   _   | |    3" TFT SCREEN    | |       |
      | _| |_ | | 256x192pix  61x46mm | |   X   |
      ||_   _|| |      BACKLIGHT      | | Y   A |
      |  |_|  | |    TOUCH SCREEN     | |   B   |
      |       | |_____________________| |       |
      |_______|             NintendoDS  |_______|
      |         MIC                LEDS         |
      |_________________________________________|
           VOL        SLOT2(GBA)     MIC/PHONES

Nintendo DS Lite (NDS-Lite)

         _____________________________________
        |        _____________________        |
        |       |                     |       |
        |       |    3" TFT SCREEN    |       |
        |  ...  | 256x192pix  61x46mm |  ...  |
        |  ...  |      BACKLIGHT      |  ...  |
        |       |      NDS-LITE       |       |
        |       |_____________________|       |
        |___  _ _ _ _ _ _ _ _ _ _ _ _ _ _ ____|   <-- gap between screens: 23mm
       L| _ |_____________MIC____________|LEDS|R
        |   _    _____________________        |
        | _| |_ |                     |   X   |
        ||_   _||    3" TFT SCREEN    | Y   A |PWR
        |  |_|  | 256x192pix  61x46mm |   B   |
        |       |      BACKLIGHT      |       |
        |       |    TOUCH SCREEN     |oSTART |
        |       |_____________________|oSELECT|
        |_____________________________________|
           VOL        SLOT2(GBA)     MIC/PHONES

Nintendo DSi (DSi)

         _____________________________________
        |        _____________________        |
        |       |                     |   O o | <-- CAM (O) and LED (o)
        |       |   3.25" TFT SCREEN  |       |     (on backside)
        |       | 256x192pix  66x50mm |       |
        |       |      BACKLIGHT      |       |
        |  __   |         DSi         |   __  |
        | (__)  |_____________________|  (__) |
        |___  _ _ _ _ _ _ _ _ _ _ _ _ _ _ ____|  <-- gap between screens: 23mm
       L|LEDS|__________CAM__MIC_________| __ |R                   (88 pixels)
      + |   _    _____________________        |
     VOL| _| |_ |                     |   X   | <-- SD Card Slot
      - ||_   _||   3.25" TFT SCREEN  | Y   A |
        |  |_|  | 256x192pix  66x50mm |   B   |
        |       |      BACKLIGHT      |       |
        |       |    TOUCH SCREEN     |oSTART |
        | POWERo|_____________________|oSELECT|
        |_____________________________________|
                                     MIC/PHONES

Nintendo DSi XL

      As DSi, but bigger case, and bigger 4.2" screens

Gameboy Player (Gamecube Joypad) (GBA Player)

                       _________
           L____-------         -------____R
           /   ___   \           /   (Y)   \Z
          /   / O \   | (START) |        (X)\   Z      = Gameboy Player Menu
         |    \___/    \_______/      (A)    |  X or Y = Select button
         |\         _   \     /    (B)      /|
         | \___   _| |_  \   /   ___    ___/ |  optionally X/Y can be
         |    |\ |_   _| /   \  / C \  /|    |  swapped with L/R (?)
         |    | \  |_|  /     \ \___/ / |    |
         |    |  \_____/       \_____/  |    |  analogue sticks = ?
          \__/                           \__/

Gameboy Player (Gamecube Bongos) (GBA Player)

           _______     _______
          /   Y   \   /   X   \   Y/B = left bongo rear/front side
         | . . . . |_| . . . . |  X/A = right bongo rear/front side
         |    B    |R|    A    |  S   = start/pause button
         |\_______/|_|\_______/|  R   = microphone (triggers R button)
         |\_______/|S|\_______/|
         |         |_|         |  (the X/Y inputs can be assigned to
         |\_______/| |\_______/|  GBA R/L inputs in GBA player setup)
          \_______/   \_______/

The GBA's separate 8bit/32bit CPU modes cannot be operated simultaneously. Switching is allowed between ARM and THUMB modes only (that are the two GBA modes).
This manual does not describe CGB and DMG modes, both are completely different than GBA modes, and both cannot be accessed from inside of GBA modes anyways.
Gameboy Player
An GBA Adapter for the Gamecube console; allowing to play GBA games on a television set.
GBA Gameboy Player
GBA SP Notes
Deluxe version of the original GBA. With backlight, new folded laptop-style case, and built-in rechargeable battery. Appears to be 100% compatible with GBA, there seems to be no way to detect SPs by software.
Gameboy Micro (GBA Micro)
Minituarized GBA. Supports 32bit GBA games only (no 8bit DMG/CGB games). The 256K Main RAM is a bit slower than usually (cannot be "overclocked via port 4000800h).
Nintendo DS (Dual Screen) Notes
New handheld with two screens, backwards compatible with GBA games, it is NOT backwards compatible with older 8bit games (mono/color gameboys) though..
Also, the DS has no link port, so that GBA games will thus work only in single player mode, link-port accessoires like printers cannot be used, and most unfortunately multiboot won't work (trying to press Select+Start at powerup will just lock up the DS).
iQue Notes
iQue is a brand name used by Nintendo in China, iQue GBA and iQue DS are essentially same as Nintendo GBA and Nintendo DS.
The iQue DS contains a larger firmware chip (the charset additionally contains about 6700 simplified chinese characters), the bootmenu still allows to select (only) six languages (japanese has been replaced by chinese). The iQue DS can play normal international NDS games, plus chinese dedicated games. The latter ones won't work on normal NDS consoles (that, reportedly simply due to a firmware-version check contained in chinese dedicated games, aside from that check, the games should be fully compatible with NDS consoles).

GBA Memory Map

General Internal Memory

      00000000-00003FFF   BIOS - System ROM         (16 KBytes)
      00004000-01FFFFFF   Not used
      02000000-0203FFFF   WRAM - On-board Work RAM  (256 KBytes) 2 Wait
      02040000-02FFFFFF   Not used
      03000000-03007FFF   WRAM - On-chip Work RAM   (32 KBytes)
      03008000-03FFFFFF   Not used
      04000000-040003FE   I/O Registers
      04000400-04FFFFFF   Not used

Internal Display Memory

      05000000-050003FF   BG/OBJ Palette RAM        (1 Kbyte)
      05000400-05FFFFFF   Not used
      06000000-06017FFF   VRAM - Video RAM          (96 KBytes)
      06018000-06FFFFFF   Not used
      07000000-070003FF   OAM - OBJ Attributes      (1 Kbyte)
      07000400-07FFFFFF   Not used

External Memory (Game Pak)

      08000000-09FFFFFF   Game Pak ROM/FlashROM (max 32MB) - Wait State 0
      0A000000-0BFFFFFF   Game Pak ROM/FlashROM (max 32MB) - Wait State 1
      0C000000-0DFFFFFF   Game Pak ROM/FlashROM (max 32MB) - Wait State 2
      0E000000-0E00FFFF   Game Pak SRAM    (max 64 KBytes) - 8bit Bus width
      0E010000-0FFFFFFF   Not used

Unused Memory Area

      10000000-FFFFFFFF   Not used (upper 4bits of address bus unused)

Default WRAM Usage
By default, the 256 bytes at 03007F00h-03007FFFh in Work RAM are reserved for Interrupt vector, Interrupt Stack, and BIOS Call Stack. The remaining WRAM is free for whatever use (including User Stack, which is initially located at 03007F00h).
Address Bus Width and CPU Read/Write Access Widths
Shows the Bus-Width, supported read and write widths, and the clock cycles for 8/16/32bit accesses.

      Region        Bus   Read      Write     Cycles
      BIOS ROM      32    8/16/32   -         1/1/1
      Work RAM 32K  32    8/16/32   8/16/32   1/1/1
      I/O           32    8/16/32   8/16/32   1/1/1
      OAM           32    8/16/32   16/32     1/1/1 *
      Work RAM 256K 16    8/16/32   8/16/32   3/3/6 **
      Palette RAM   16    8/16/32   16/32     1/1/2 *
      VRAM          16    8/16/32   16/32     1/1/2 *
      GamePak ROM   16    8/16/32   -         5/5/8 **/***
      GamePak Flash 16    8/16/32   16/32     5/5/8 **/***
      GamePak SRAM  8     8         8         5     **

Timing Notes:

      *   Plus 1 cycle if GBA accesses video memory at the same time.
      **  Default waitstate settings, see System Control chapter.
      *** Separate timings for sequential, and non-sequential accesses.
      One cycle equals approx. 59.59ns (ie. 16.78MHz clock).

All memory (except GamePak SRAM) can be accessed by 16bit and 32bit DMA.
GamePak Memory
Only DMA3 (and the CPU of course) may access GamePak ROM. GamePak SRAM can be accessed by the CPU only - restricted to bytewise 8bit transfers. The SRAM region is supposed for as external FLASH backup memory, or for battery-backed SRAM.
For details about configuration of GamePak Waitstates, see:
GBA System Control
VRAM, OAM, and Palette RAM Access
These memory regions can be accessed during H-Blank or V-Blank only (unless display is disabled by Forced Blank bit in DISPCNT register).
There is an additional restriction for OAM memory: Accesses during H-Blank are allowed only if 'H-Blank Interval Free' in DISPCNT is set (which'd reduce number of display-able OBJs though).
The CPU appears to be able to access VRAM/OAM/Palette at any time, a waitstate (one clock cycle) being inserted automatically in case that the display controller was accessing memory simultaneously. (Ie. unlike as in old 8bit gameboy, the data will not get lost.)
CPU Mode Performance
Note that the GamePak ROM bus is limited to 16bits, thus executing ARM instructions (32bit opcodes) from inside of GamePak ROM would result in a not so good performance. So, it'd be more recommended to use THUMB instruction (16bit opcodes) which'd allow each opcode to be read at once.
(ARM instructions can be used at best performance by copying code from GamePak ROM into internal Work RAM)
Data Format
Even though the ARM CPU itself would allow to select between Little-Endian and Big-Endian format by using an external circuit, in the GBA no such circuit exists, and the data format is always Little-Endian. That is, when accessing 16bit or 32bit data in memory, the least significant bits are stored in the first byte (smallest address), and the most significant bits in the last byte. (Ie. same as for 80x86 and Z80 CPUs.)

GBA I/O Map

LCD I/O Registers

      4000000h  2    R/W  DISPCNT   LCD Control
      4000002h  2    R/W  -         Undocumented - Green Swap
      4000004h  2    R/W  DISPSTAT  General LCD Status (STAT,LYC)
      4000006h  2    R    VCOUNT    Vertical Counter (LY)
      4000008h  2    R/W  BG0CNT    BG0 Control
      400000Ah  2    R/W  BG1CNT    BG1 Control
      400000Ch  2    R/W  BG2CNT    BG2 Control
      400000Eh  2    R/W  BG3CNT    BG3 Control
      4000010h  2    W    BG0HOFS   BG0 X-Offset
      4000012h  2    W    BG0VOFS   BG0 Y-Offset
      4000014h  2    W    BG1HOFS   BG1 X-Offset
      4000016h  2    W    BG1VOFS   BG1 Y-Offset
      4000018h  2    W    BG2HOFS   BG2 X-Offset
      400001Ah  2    W    BG2VOFS   BG2 Y-Offset
      400001Ch  2    W    BG3HOFS   BG3 X-Offset
      400001Eh  2    W    BG3VOFS   BG3 Y-Offset
      4000020h  2    W    BG2PA     BG2 Rotation/Scaling Parameter A (dx)
      4000022h  2    W    BG2PB     BG2 Rotation/Scaling Parameter B (dmx)
      4000024h  2    W    BG2PC     BG2 Rotation/Scaling Parameter C (dy)
      4000026h  2    W    BG2PD     BG2 Rotation/Scaling Parameter D (dmy)
      4000028h  4    W    BG2X      BG2 Reference Point X-Coordinate
      400002Ch  4    W    BG2Y      BG2 Reference Point Y-Coordinate
      4000030h  2    W    BG3PA     BG3 Rotation/Scaling Parameter A (dx)
      4000032h  2    W    BG3PB     BG3 Rotation/Scaling Parameter B (dmx)
      4000034h  2    W    BG3PC     BG3 Rotation/Scaling Parameter C (dy)
      4000036h  2    W    BG3PD     BG3 Rotation/Scaling Parameter D (dmy)
      4000038h  4    W    BG3X      BG3 Reference Point X-Coordinate
      400003Ch  4    W    BG3Y      BG3 Reference Point Y-Coordinate
      4000040h  2    W    WIN0H     Window 0 Horizontal Dimensions
      4000042h  2    W    WIN1H     Window 1 Horizontal Dimensions
      4000044h  2    W    WIN0V     Window 0 Vertical Dimensions
      4000046h  2    W    WIN1V     Window 1 Vertical Dimensions
      4000048h  2    R/W  WININ     Inside of Window 0 and 1
      400004Ah  2    R/W  WINOUT    Inside of OBJ Window & Outside of Windows
      400004Ch  2    W    MOSAIC    Mosaic Size
      400004Eh       -    -         Not used
      4000050h  2    R/W  BLDCNT    Color Special Effects Selection
      4000052h  2    R/W  BLDALPHA  Alpha Blending Coefficients
      4000054h  2    W    BLDY      Brightness (Fade-In/Out) Coefficient
      4000056h       -    -         Not used

Sound Registers

      4000060h  2  R/W  SOUND1CNT_L Channel 1 Sweep register       (NR10)
      4000062h  2  R/W  SOUND1CNT_H Channel 1 Duty/Length/Envelope (NR11, NR12)
      4000064h  2  R/W  SOUND1CNT_X Channel 1 Frequency/Control    (NR13, NR14)
      4000066h     -    -           Not used
      4000068h  2  R/W  SOUND2CNT_L Channel 2 Duty/Length/Envelope (NR21, NR22)
      400006Ah     -    -           Not used
      400006Ch  2  R/W  SOUND2CNT_H Channel 2 Frequency/Control    (NR23, NR24)
      400006Eh     -    -           Not used
      4000070h  2  R/W  SOUND3CNT_L Channel 3 Stop/Wave RAM select (NR30)
      4000072h  2  R/W  SOUND3CNT_H Channel 3 Length/Volume        (NR31, NR32)
      4000074h  2  R/W  SOUND3CNT_X Channel 3 Frequency/Control    (NR33, NR34)
      4000076h     -    -           Not used
      4000078h  2  R/W  SOUND4CNT_L Channel 4 Length/Envelope      (NR41, NR42)
      400007Ah     -    -           Not used
      400007Ch  2  R/W  SOUND4CNT_H Channel 4 Frequency/Control    (NR43, NR44)
      400007Eh     -    -           Not used
      4000080h  2  R/W  SOUNDCNT_L  Control Stereo/Volume/Enable   (NR50, NR51)
      4000082h  2  R/W  SOUNDCNT_H  Control Mixing/DMA Control
      4000084h  2  R/W  SOUNDCNT_X  Control Sound on/off           (NR52)
      4000086h     -    -           Not used
      4000088h  2  BIOS SOUNDBIAS   Sound PWM Control
      400008Ah  ..   -    -         Not used
      4000090h 2x10h R/W  WAVE_RAM  Channel 3 Wave Pattern RAM (2 banks!!)
      40000A0h  4    W    FIFO_A    Channel A FIFO, Data 0-3
      40000A4h  4    W    FIFO_B    Channel B FIFO, Data 0-3
      40000A8h       -    -         Not used

DMA Transfer Channels

      40000B0h  4    W    DMA0SAD   DMA 0 Source Address
      40000B4h  4    W    DMA0DAD   DMA 0 Destination Address
      40000B8h  2    W    DMA0CNT_L DMA 0 Word Count
      40000BAh  2    R/W  DMA0CNT_H DMA 0 Control
      40000BCh  4    W    DMA1SAD   DMA 1 Source Address
      40000C0h  4    W    DMA1DAD   DMA 1 Destination Address
      40000C4h  2    W    DMA1CNT_L DMA 1 Word Count
      40000C6h  2    R/W  DMA1CNT_H DMA 1 Control
      40000C8h  4    W    DMA2SAD   DMA 2 Source Address
      40000CCh  4    W    DMA2DAD   DMA 2 Destination Address
      40000D0h  2    W    DMA2CNT_L DMA 2 Word Count
      40000D2h  2    R/W  DMA2CNT_H DMA 2 Control
      40000D4h  4    W    DMA3SAD   DMA 3 Source Address
      40000D8h  4    W    DMA3DAD   DMA 3 Destination Address
      40000DCh  2    W    DMA3CNT_L DMA 3 Word Count
      40000DEh  2    R/W  DMA3CNT_H DMA 3 Control
      40000E0h       -    -         Not used

Timer Registers

      4000100h  2    R/W  TM0CNT_L  Timer 0 Counter/Reload
      4000102h  2    R/W  TM0CNT_H  Timer 0 Control
      4000104h  2    R/W  TM1CNT_L  Timer 1 Counter/Reload
      4000106h  2    R/W  TM1CNT_H  Timer 1 Control
      4000108h  2    R/W  TM2CNT_L  Timer 2 Counter/Reload
      400010Ah  2    R/W  TM2CNT_H  Timer 2 Control
      400010Ch  2    R/W  TM3CNT_L  Timer 3 Counter/Reload
      400010Eh  2    R/W  TM3CNT_H  Timer 3 Control
      4000110h       -    -         Not used

Serial Communication (1)

      4000120h  4    R/W  SIODATA32 SIO Data (Normal-32bit Mode; shared with below)
      4000120h  2    R/W  SIOMULTI0 SIO Data 0 (Parent)    (Multi-Player Mode)
      4000122h  2    R/W  SIOMULTI1 SIO Data 1 (1st Child) (Multi-Player Mode)
      4000124h  2    R/W  SIOMULTI2 SIO Data 2 (2nd Child) (Multi-Player Mode)
      4000126h  2    R/W  SIOMULTI3 SIO Data 3 (3rd Child) (Multi-Player Mode)
      4000128h  2    R/W  SIOCNT    SIO Control Register
      400012Ah  2    R/W  SIOMLT_SEND SIO Data (Local of MultiPlayer; shared below)
      400012Ah  2    R/W  SIODATA8  SIO Data (Normal-8bit and UART Mode)
      400012Ch       -    -         Not used

Keypad Input

      4000130h  2    R    KEYINPUT  Key Status
      4000132h  2    R/W  KEYCNT    Key Interrupt Control

Serial Communication (2)

      4000134h  2    R/W  RCNT      SIO Mode Select/General Purpose Data
      4000136h  -    -    IR        Ancient - Infrared Register (Prototypes only)
      4000138h       -    -         Not used
      4000140h  2    R/W  JOYCNT    SIO JOY Bus Control
      4000142h       -    -         Not used
      4000150h  4    R/W  JOY_RECV  SIO JOY Bus Receive Data
      4000154h  4    R/W  JOY_TRANS SIO JOY Bus Transmit Data
      4000158h  2    R/?  JOYSTAT   SIO JOY Bus Receive Status
      400015Ah       -    -         Not used

Interrupt, Waitstate, and Power-Down Control

      4000200h  2    R/W  IE        Interrupt Enable Register
      4000202h  2    R/W  IF        Interrupt Request Flags / IRQ Acknowledge
      4000204h  2    R/W  WAITCNT   Game Pak Waitstate Control
      4000206h       -    -         Not used
      4000208h  2    R/W  IME       Interrupt Master Enable Register
      400020Ah       -    -         Not used
      4000300h  1    R/W  POSTFLG   Undocumented - Post Boot Flag
      4000301h  1    W    HALTCNT   Undocumented - Power Down Control
      4000302h       -    -         Not used
      4000410h  ?    ?    ?         Undocumented - Purpose Unknown / Bug ??? 0FFh
      4000411h       -    -         Not used
      4000800h  4    R/W  ?         Undocumented - Internal Memory Control (R/W)
      4000804h       -    -         Not used
      4xx0800h  4    R/W  ?         Mirrors of 4000800h (repeated each 64K)
      4700000h  4    W    (3DS)     Disable ARM7 bootrom overlay (3DS only)

All further addresses at 4XXXXXXh are unused and do not contain mirrors of the I/O area, with the only exception that 4000800h is repeated each 64K (ie. mirrored at 4010800h, 4020800h, etc.)

GBA LCD Video Controller

Registers
LCD I/O Display Control
LCD I/O Interrupts and Status
LCD I/O BG Control
LCD I/O BG Scrolling
LCD I/O BG Rotation/Scaling
LCD I/O Window Feature
LCD I/O Mosaic Function
LCD I/O Color Special Effects
VRAM
LCD VRAM Overview
LCD VRAM Character Data
LCD VRAM BG Screen Data Format (BG Map)
LCD VRAM Bitmap BG Modes
Sprites
LCD OBJ - Overview
LCD OBJ - OAM Attributes
LCD OBJ - OAM Rotation/Scaling Parameters
LCD OBJ - VRAM Character (Tile) Mapping
Other
LCD Color Palettes
LCD Dimensions and Timings

LCD I/O Display Control

4000000h - DISPCNT - LCD Control (Read/Write)

      Bit   Expl.
      0-2   BG Mode                (0-5=Video Mode 0-5, 6-7=Prohibited)
      3     Reserved / CGB Mode    (0=GBA, 1=CGB; can be set only by BIOS opcodes)
      4     Display Frame Select   (0-1=Frame 0-1) (for BG Modes 4,5 only)
      5     H-Blank Interval Free  (1=Allow access to OAM during H-Blank)
      6     OBJ Character VRAM Mapping (0=Two dimensional, 1=One dimensional)
      7     Forced Blank           (1=Allow FAST access to VRAM,Palette,OAM)
      8     Screen Display BG0  (0=Off, 1=On)
      9     Screen Display BG1  (0=Off, 1=On)
      10    Screen Display BG2  (0=Off, 1=On)
      11    Screen Display BG3  (0=Off, 1=On)
      12    Screen Display OBJ  (0=Off, 1=On)
      13    Window 0 Display Flag   (0=Off, 1=On)
      14    Window 1 Display Flag   (0=Off, 1=On)
      15    OBJ Window Display Flag (0=Off, 1=On)

The table summarizes the facilities of the separate BG modes (video modes).

      Mode  Rot/Scal Layers Size               Tiles Colors       Features
      0     No       0123   256x256..512x515   1024  16/16..256/1 SFMABP
      1     Mixed    012-   (BG0,BG1 as above Mode 0, BG2 as below Mode 2)
      2     Yes      --23   128x128..1024x1024 256   256/1        S-MABP
      3     Yes      --2-   240x160            1     32768        --MABP
      4     Yes      --2-   240x160            2     256/1        --MABP
      5     Yes      --2-   160x128            2     32768        --MABP

Features: S)crolling, F)lip, M)osaic, A)lphaBlending, B)rightness, P)riority.
BG Modes 0-2 are Tile/Map-based. BG Modes 3-5 are Bitmap-based, in these modes 1 or 2 Frames (ie. bitmaps, or 'full screen tiles') exists, if two frames exist, either one can be displayed, and the other one can be redrawn in background.
Blanking Bits
Setting Forced Blank (Bit 7) causes the video controller to display white lines, and all VRAM, Palette RAM, and OAM may be accessed.
"When the internal HV synchronous counter cancels a forced blank during a display period, the display begins from the beginning, following the display of two vertical lines." What ?
Setting H-Blank Interval Free (Bit 5) allows to access OAM during H-Blank time - using this feature reduces the number of sprites that can be displayed per line.
Display Enable Bits
By default, BG0-3 and OBJ Display Flags (Bit 8-12) are used to enable/disable BGs and OBJ. When enabling Window 0 and/or 1 (Bit 13-14), color special effects may be used, and BG0-3 and OBJ are controlled by the window(s).
Frame Selection
In BG Modes 4 and 5 (Bitmap modes), either one of the two bitmaps/frames may be displayed (Bit 4), allowing the user to update the other (invisible) frame in background. In BG Mode 3, only one frame exists.
In BG Modes 0-2 (Tile/Map based modes), a similar effect may be gained by altering the base address(es) of BG Map and/or BG Character data.
4000002h - Undocumented - Green Swap (R/W)
Normally, red green blue intensities for a group of two pixels is output as BGRbgr (uppercase for left pixel at even xloc, lowercase for right pixel at odd xloc). When the Green Swap bit is set, each pixel group is output as BgRbGr (ie. green intensity of each two pixels exchanged).

      Bit   Expl.
      0     Green Swap  (0=Normal, 1=Swap)
      1-15  Not used

This feature appears to be applied to the final picture (ie. after mixing the separate BG and OBJ layers). Eventually intended for other display types (with other pin-outs). With normal GBA hardware it is just producing an interesting dirt effect.
The NDS DISPCNT registers are 32bit (4000000h..4000003h), so Green Swap doesn't exist in NDS mode, however, the NDS does support Green Swap in GBA mode.

LCD I/O Interrupts and Status

4000004h - DISPSTAT - General LCD Status (Read/Write)
Display status and Interrupt control. The H-Blank conditions are generated once per scanline, including for the 'hidden' scanlines during V-Blank.

      Bit   Expl.
      0     V-Blank flag   (Read only) (1=VBlank) (set in line 160..226; not 227)
      1     H-Blank flag   (Read only) (1=HBlank) (toggled in all lines, 0..227)
      2     V-Counter flag (Read only) (1=Match)  (set in selected line)     (R)
      3     V-Blank IRQ Enable         (1=Enable)                          (R/W)
      4     H-Blank IRQ Enable         (1=Enable)                          (R/W)
      5     V-Counter IRQ Enable       (1=Enable)                          (R/W)
      6     Not used (0) / DSi: LCD Initialization Ready (0=Busy, 1=Ready)   (R)
      7     Not used (0) / NDS: MSB of V-Vcount Setting (LYC.Bit8) (0..262)(R/W)
      8-15  V-Count Setting (LYC)      (0..227)                            (R/W)

The V-Count-Setting value is much the same as LYC of older gameboys, when its value is identical to the content of the VCOUNT register then the V-Counter flag is set (Bit 2), and (if enabled in Bit 5) an interrupt is requested.
Although the drawing time is only 960 cycles (240*4), the H-Blank flag is "0" for a total of 1006 cycles.
4000006h - VCOUNT - Vertical Counter (Read only)
Indicates the currently drawn scanline, values in range from 160..227 indicate 'hidden' scanlines within VBlank area.

      Bit   Expl.
      0-7   Current Scanline (LY)      (0..227)                              (R)
      8     Not used (0) / NDS: MSB of Current Scanline (LY.Bit8) (0..262)   (R)
      9-15  Not Used (0)

Note: This is much the same than the 'LY' register of older gameboys.

LCD I/O BG Control

4000008h - BG0CNT - BG0 Control (R/W) (BG Modes 0,1 only)
400000Ah - BG1CNT - BG1 Control (R/W) (BG Modes 0,1 only)
400000Ch - BG2CNT - BG2 Control (R/W) (BG Modes 0,1,2 only)
400000Eh - BG3CNT - BG3 Control (R/W) (BG Modes 0,2 only)

      Bit   Expl.
      0-1   BG Priority           (0-3, 0=Highest)
      2-3   Character Base Block  (0-3, in units of 16 KBytes) (=BG Tile Data)
      4-5   Not used (must be zero) (except in NDS mode: MSBs of char base)
      6     Mosaic                (0=Disable, 1=Enable)
      7     Colors/Palettes       (0=16/16, 1=256/1)
      8-12  Screen Base Block     (0-31, in units of 2 KBytes) (=BG Map Data)
      13    BG0/BG1: Not used (except in NDS mode: Ext Palette Slot for BG0/BG1)
      13    BG2/BG3: Display Area Overflow (0=Transparent, 1=Wraparound)
      14-15 Screen Size (0-3)

Internal Screen Size (dots) and size of BG Map (bytes):

      Value  Text Mode      Rotation/Scaling Mode
      0      256x256 (2K)   128x128   (256 bytes)
      1      512x256 (4K)   256x256   (1K)
      2      256x512 (4K)   512x512   (4K)
      3      512x512 (8K)   1024x1024 (16K)

In case that some or all BGs are set to same priority then BG0 is having the highest, and BG3 the lowest priority.
In 'Text Modes', the screen size is organized as follows: The screen consists of one or more 256x256 pixel (32x32 tiles) areas. When Size=0: only 1 area (SC0), when Size=1 or Size=2: two areas (SC0,SC1 either horizontally or vertically arranged next to each other), when Size=3: four areas (SC0,SC1 in upper row, SC2,SC3 in lower row). Whereas SC0 is defined by the normal BG Map base address (Bit 8-12 of BGxCNT), SC1 uses same address +2K, SC2 address +4K, SC3 address +6K. When the screen is scrolled it'll always wraparound.
In 'Rotation/Scaling Modes', the screen size is organized as follows, only one area (SC0) of variable size 128x128..1024x1024 pixels (16x16..128x128 tiles) exists. When the screen is rotated/scaled (or scrolled?) so that the LCD viewport reaches outside of the background/screen area, then BG may be either displayed as transparent or wraparound (Bit 13 of BGxCNT).

LCD I/O BG Scrolling

4000010h - BG0HOFS - BG0 X-Offset (W)
4000012h - BG0VOFS - BG0 Y-Offset (W)

      Bit   Expl.
      0-8   Offset (0-511)
      9-15  Not used

Specifies the coordinate of the upperleft first visible dot of BG0 background layer, ie. used to scroll the BG0 area.
4000014h - BG1HOFS - BG1 X-Offset (W)
4000016h - BG1VOFS - BG1 Y-Offset (W)
Same as above BG0HOFS and BG0VOFS for BG1 respectively.
4000018h - BG2HOFS - BG2 X-Offset (W)
400001Ah - BG2VOFS - BG2 Y-Offset (W)
Same as above BG0HOFS and BG0VOFS for BG2 respectively.
400001Ch - BG3HOFS - BG3 X-Offset (W)
400001Eh - BG3VOFS - BG3 Y-Offset (W)
Same as above BG0HOFS and BG0VOFS for BG3 respectively.
The above BG scrolling registers are exclusively used in Text modes, ie. for all layers in BG Mode 0, and for the first two layers in BG mode 1.
In other BG modes (Rotation/Scaling and Bitmap modes) above registers are ignored. Instead, the screen may be scrolled by modifying the BG Rotation/Scaling Reference Point registers.

LCD I/O BG Rotation/Scaling

4000028h - BG2X_L - BG2 Reference Point X-Coordinate, lower 16 bit (W)
400002Ah - BG2X_H - BG2 Reference Point X-Coordinate, upper 12 bit (W)
400002Ch - BG2Y_L - BG2 Reference Point Y-Coordinate, lower 16 bit (W)
400002Eh - BG2Y_H - BG2 Reference Point Y-Coordinate, upper 12 bit (W)
These registers are replacing the BG scrolling registers which are used for Text mode, ie. the X/Y coordinates specify the source position from inside of the BG Map/Bitmap of the pixel to be displayed at upper left of the GBA display. The normal BG scrolling registers are ignored in Rotation/Scaling and Bitmap modes.

      Bit   Expl.
      0-7   Fractional portion (8 bits)
      8-26  Integer portion    (19 bits)
      27    Sign               (1 bit)
      28-31 Not used

Because values are shifted left by eight, fractional portions may be specified in steps of 1/256 pixels (this would be relevant only if the screen is actually rotated or scaled). Normal signed 32bit values may be written to above registers (the most significant bits will be ignored and the value will be cut-down to 28bits, but this is no actual problem because signed values have set all MSBs to the same value).
Internal Reference Point Registers
The above reference points are automatically copied to internal registers during each vblank, specifying the origin for the first scanline. The internal registers are then incremented by dmx and dmy after each scanline.
Caution: Writing to a reference point register by software outside of the Vblank period does immediately copy the new value to the corresponding internal register, that means: in the current frame, the new value specifies the origin of the <current> scanline (instead of the topmost scanline).
4000020h - BG2PA - BG2 Rotation/Scaling Parameter A (alias dx) (W)
4000022h - BG2PB - BG2 Rotation/Scaling Parameter B (alias dmx) (W)
4000024h - BG2PC - BG2 Rotation/Scaling Parameter C (alias dy) (W)
4000026h - BG2PD - BG2 Rotation/Scaling Parameter D (alias dmy) (W)

      Bit   Expl.
      0-7   Fractional portion (8 bits)
      8-14  Integer portion    (7 bits)
      15    Sign               (1 bit)

See below for details.
400003Xh - BG3X_L/H, BG3Y_L/H, BG3PA-D - BG3 Rotation/Scaling Parameters
Same as above BG2 Reference Point, and Rotation/Scaling Parameters, for BG3 respectively.
dx (PA) and dy (PC)
When transforming a horizontal line, dx and dy specify the resulting gradient and magnification for that line. For example:
Horizontal line, length=100, dx=1, and dy=1. The resulting line would be drawn at 45 degrees, f(y)=1/1*x. Note that this would involve that line is magnified, the new length is SQR(100^2+100^2)=141.42. Yup, exactly - that's the old a^2 + b^2 = c^2 formula.
dmx (PB) and dmy (PD)
These values define the resulting gradient and magnification for transformation of vertical lines. However, when rotating a square area (which is surrounded by horizontal and vertical lines), then the desired result should be usually a rotated <square> area (ie. not a parallelogram, for example).
Thus, dmx and dmy must be defined in direct relationship to dx and dy, taking the example above, we'd have to set dmx=-1, and dmy=1, f(x)=-1/1*y.
Area Overflow
In result of rotation/scaling it may often happen that areas outside of the actual BG area become moved into the LCD viewport. Depending of the Area Overflow bit (BG2CNT and BG3CNT, Bit 13) these areas may be either displayed (by wrapping the BG area), or may be displayed transparent.
This works only in BG modes 1 and 2. The area overflow is ignored in Bitmap modes (BG modes 3-5), the outside of the Bitmaps is always transparent.
--- more details and confusing or helpful formulas ---
The following parameters are required for Rotation/Scaling

      Rotation Center X and Y Coordinates (x0,y0)
      Rotation Angle                      (alpha)
      Magnification X and Y Values        (xMag,yMag)

The display is rotated by 'alpha' degrees around the center.
The displayed picture is magnified by 'xMag' along x-Axis (Y=y0) and 'yMag' along y-Axis (X=x0).
Calculating Rotation/Scaling Parameters A-D

      A = Cos (alpha) / xMag    ;distance moved in direction x, same line
      B = Sin (alpha) / xMag    ;distance moved in direction x, next line
      C = Sin (alpha) / yMag    ;distance moved in direction y, same line
      D = Cos (alpha) / yMag    ;distance moved in direction y, next line

Calculating the position of a rotated/scaled dot
Using the following expressions,

      x0,y0    Rotation Center
      x1,y1    Old Position of a pixel (before rotation/scaling)
      x2,y2    New position of above pixel (after rotation scaling)
      A,B,C,D  BG2PA-BG2PD Parameters (as calculated above)

the following formula can be used to calculate x2,y2:

      x2 = A(x1-x0) + B(y1-y0) + x0
      y2 = C(x1-x0) + D(y1-y0) + y0

LCD I/O Window Feature

The Window Feature may be used to split the screen into four regions. The BG0-3,OBJ layers and Color Special Effects can be separately enabled or disabled in each of these regions.
The DISPCNT Register
DISPCNT Bits 13-15 are used to enable Window 0, Window 1, and/or OBJ Window regions, if any of these regions is enabled then the "Outside of Windows" region is automatically enabled, too.
DISPCNT Bits 8-12 are kept used as master enable bits for the BG0-3,OBJ layers, a layer is displayed only if both DISPCNT and WININ/OUT enable bits are set.
4000040h - WIN0H - Window 0 Horizontal Dimensions (W)
4000042h - WIN1H - Window 1 Horizontal Dimensions (W)

      Bit   Expl.
      0-7   X2, Rightmost coordinate of window, plus 1
      8-15  X1, Leftmost coordinate of window

Garbage values of X2>240 or X1>X2 are interpreted as X2=240.
4000044h - WIN0V - Window 0 Vertical Dimensions (W)
4000046h - WIN1V - Window 1 Vertical Dimensions (W)

      Bit   Expl.
      0-7   Y2, Bottom-most coordinate of window, plus 1
      8-15  Y1, Top-most coordinate of window

Garbage values of Y2>160 or Y1>Y2 are interpreted as Y2=160.
4000048h - WININ - Control of Inside of Window(s) (R/W)

      Bit   Expl.
      0-3   Window 0 BG0-BG3 Enable Bits     (0=No Display, 1=Display)
      4     Window 0 OBJ Enable Bit          (0=No Display, 1=Display)
      5     Window 0 Color Special Effect    (0=Disable, 1=Enable)
      6-7   Not used
      8-11  Window 1 BG0-BG3 Enable Bits     (0=No Display, 1=Display)
      12    Window 1 OBJ Enable Bit          (0=No Display, 1=Display)
      13    Window 1 Color Special Effect    (0=Disable, 1=Enable)
      14-15 Not used

400004Ah - WINOUT - Control of Outside of Windows & Inside of OBJ Window (R/W)

      Bit   Expl.
      0-3   Outside BG0-BG3 Enable Bits      (0=No Display, 1=Display)
      4     Outside OBJ Enable Bit           (0=No Display, 1=Display)
      5     Outside Color Special Effect     (0=Disable, 1=Enable)
      6-7   Not used
      8-11  OBJ Window BG0-BG3 Enable Bits   (0=No Display, 1=Display)
      12    OBJ Window OBJ Enable Bit        (0=No Display, 1=Display)
      13    OBJ Window Color Special Effect  (0=Disable, 1=Enable)
      14-15 Not used

The OBJ Window
The dimension of the OBJ Window is specified by OBJs which are having the "OBJ Mode" attribute being set to "OBJ Window". Any non-transparent dots of any such OBJs are marked as OBJ Window area. The OBJ itself is not displayed.
The color, palette, and display priority of these OBJs are ignored. Both DISPCNT Bits 12 and 15 must be set when defining OBJ Window region(s).
Window Priority
In case that more than one window is enabled, and that these windows do overlap, Window 0 is having highest priority, Window 1 medium, and Obj Window lowest priority. Outside of Window is having zero priority, it is used for all dots which are not inside of any window region.

LCD I/O Mosaic Function

400004Ch - MOSAIC - Mosaic Size (W)
The Mosaic function can be separately enabled/disabled for BG0-BG3 by BG0CNT-BG3CNT Registers, as well as for each OBJ0-127 by OBJ attributes in OAM memory. Also, setting all of the bits below to zero effectively disables the mosaic function.

      Bit   Expl.
      0-3   BG Mosaic H-Size  (minus 1)
      4-7   BG Mosaic V-Size  (minus 1)
      8-11  OBJ Mosaic H-Size (minus 1)
      12-15 OBJ Mosaic V-Size (minus 1)
      16-31 Not used

Example: When setting H-Size to 5, then pixels 0-5 of each display row are colorized as pixel 0, pixels 6-11 as pixel 6, pixels 12-17 as pixel 12, and so on.
Normally, a 'mosaic-pixel' is colorized by the color of the upperleft covered pixel. In many cases it might be more desireful to use the color of the pixel in the center of the covered area - this effect may be gained by scrolling the background (or by adjusting the OBJ position, as far as upper/left rows/columns of OBJ are transparent).

LCD I/O Color Special Effects

Two types of Special Effects are supported: Alpha Blending (Semi-Transparency) allows to combine colors of two selected surfaces. Brightness Increase/Decrease adjust the brightness of the selected surface.
4000050h - BLDCNT - Color Special Effects Selection (R/W)

      Bit   Expl.
      0     BG0 1st Target Pixel (Background 0)
      1     BG1 1st Target Pixel (Background 1)
      2     BG2 1st Target Pixel (Background 2)
      3     BG3 1st Target Pixel (Background 3)
      4     OBJ 1st Target Pixel (Top-most OBJ pixel)
      5     BD  1st Target Pixel (Backdrop)
      6-7   Color Special Effect (0-3, see below)
             0 = None                (Special effects disabled)
             1 = Alpha Blending      (1st+2nd Target mixed)
             2 = Brightness Increase (1st Target becomes whiter)
             3 = Brightness Decrease (1st Target becomes blacker)
      8     BG0 2nd Target Pixel (Background 0)
      9     BG1 2nd Target Pixel (Background 1)
      10    BG2 2nd Target Pixel (Background 2)
      11    BG3 2nd Target Pixel (Background 3)
      12    OBJ 2nd Target Pixel (Top-most OBJ pixel)
      13    BD  2nd Target Pixel (Backdrop)
      14-15 Not used

Selects the 1st Target layer(s) for special effects. For Alpha Blending/Semi-Transparency, it does also select the 2nd Target layer(s), which should have next lower display priority as the 1st Target.
However, any combinations are possible, including that all layers may be selected as both 1st+2nd target, in that case the top-most pixel will be used as 1st target, and the next lower pixel as 2nd target.
4000052h - BLDALPHA - Alpha Blending Coefficients (R/W) (not W)
Used for Color Special Effects Mode 1, and for Semi-Transparent OBJs.

      Bit   Expl.
      0-4   EVA Coefficient (1st Target) (0..16 = 0/16..16/16, 17..31=16/16)
      5-7   Not used
      8-12  EVB Coefficient (2nd Target) (0..16 = 0/16..16/16, 17..31=16/16)
      13-15 Not used

For this effect, the top-most non-transparent pixel must be selected as 1st Target, and the next-lower non-transparent pixel must be selected as 2nd Target, if so - and only if so, then color intensities of 1st and 2nd Target are mixed together by using the parameters in BLDALPHA register, for each pixel each R, G, B intensities are calculated separately:

      I = MIN ( 31, I1st*EVA + I2nd*EVB )

Otherwise - for example, if only one target exists, or if a non-transparent non-2nd-target pixel is moved between the two targets, or if 2nd target has higher display priority than 1st target - then only the top-most pixel is displayed (at normal intensity, regardless of BLDALPHA).
4000054h - BLDY - Brightness (Fade-In/Out) Coefficient (W) (not R/W)
Used for Color Special Effects Modes 2 and 3.

      Bit   Expl.
      0-4   EVY Coefficient (Brightness) (0..16 = 0/16..16/16, 17..31=16/16)
      5-31  Not used

For each pixel each R, G, B intensities are calculated separately:

      I = I1st + (31-I1st)*EVY   ;For Brightness Increase
      I = I1st - (I1st)*EVY      ;For Brightness Decrease

The color intensities of any selected 1st target surface(s) are increased or decreased by using the parameter in BLDY register.
Semi-Transparent OBJs
OBJs that are defined as 'Semi-Transparent' in OAM memory are always selected as 1st Target (regardless of BLDCNT Bit 4), and are always using Alpha Blending mode (regardless of BLDCNT Bit 6-7).
The BLDCNT register may be used to perform Brightness effects on the OBJ (and/or other BG/BD layers). However, if a semi-transparent OBJ pixel does overlap a 2nd target pixel, then semi-transparency becomes priority, and the brightness effect will not take place (neither on 1st, nor 2nd target).
The OBJ Layer
Before special effects are applied, the display controller computes the OBJ priority ordering, and isolates the top-most OBJ pixel. In result, only the top-most OBJ pixel is recursed at the time when processing special effects. Ie. alpha blending and semi-transparency can be used for OBJ-to-BG or BG-to-OBJ , but not for OBJ-to-OBJ.

LCD VRAM Overview

The GBA contains 96 Kbytes VRAM built-in, located at address 06000000-06017FFF, depending on the BG Mode used as follows:
BG Mode 0,1,2 (Tile/Map based Modes)

      06000000-0600FFFF  64 KBytes shared for BG Map and Tiles
      06010000-06017FFF  32 KBytes OBJ Tiles

The shared 64K area can be split into BG Map area(s), and BG Tiles area(s), the respective addresses for Map and Tile areas are set up by BG0CNT-BG3CNT registers. The Map address may be specified in units of 2K (steps of 800h), the Tile address in units of 16K (steps of 4000h).
BG Mode 0,1 (Tile/Map based Text mode)
The tiles may have 4bit or 8bit color depth, minimum map size is 32x32 tiles, maximum is 64x64 tiles, up to 1024 tiles can be used per map.

      Item        Depth     Required Memory
      One Tile    4bit      20h bytes
      One Tile    8bit      40h bytes
      1024 Tiles  4bit      8000h (32K)
      1024 Tiles  8bit      10000h (64K) - excluding some bytes for BG map
      BG Map      32x32     800h (2K)
      BG Map      64x64     2000h (8K)

BG Mode 1,2 (Tile/Map based Rotation/Scaling mode)
The tiles may have 8bit color depth only, minimum map size is 16x16 tiles, maximum is 128x128 tiles, up to 256 tiles can be used per map.

      Item        Depth     Required Memory
      One Tile    8bit      40h bytes
      256  Tiles  8bit      4000h (16K)
      BG Map      16x16     100h bytes
      BG Map      128x128   4000h (16K)

BG Mode 3 (Bitmap based Mode for still images)

      06000000-06013FFF  80 KBytes Frame 0 buffer (only 75K actually used)
      06014000-06017FFF  16 KBytes OBJ Tiles

BG Mode 4,5 (Bitmap based Modes)

      06000000-06009FFF  40 KBytes Frame 0 buffer (only 37.5K used in Mode 4)
      0600A000-06013FFF  40 KBytes Frame 1 buffer (only 37.5K used in Mode 4)
      06014000-06017FFF  16 KBytes OBJ Tiles

Note
Additionally to the above VRAM, the GBA also contains 1 KByte Palette RAM (at 05000000h) and 1 KByte OAM (at 07000000h) which are both used by the display controller as well.

LCD VRAM Character Data

Each character (tile) consists of 8x8 dots (64 dots in total). The color depth may be either 4bit or 8bit (see BG0CNT-BG3CNT).
4bit depth (16 colors, 16 palettes)
Each tile occupies 32 bytes of memory, the first 4 bytes for the topmost row of the tile, and so on. Each byte representing two dots, the lower 4 bits define the color for the left (!) dot, the upper 4 bits the color for the right dot.
8bit depth (256 colors, 1 palette)
Each tile occupies 64 bytes of memory, the first 8 bytes for the topmost row of the tile, and so on. Each byte selects the palette entry for each dot.

LCD VRAM BG Screen Data Format (BG Map)

The display background consists of 8x8 dot tiles, the arrangement of these tiles is specified by the BG Screen Data (BG Map). The separate entries in this map are as follows:
Text BG Screen (2 bytes per entry)
Specifies the tile number and attributes. Note that BG tile numbers are always specified in steps of 1 (unlike OBJ tile numbers which are using steps of two in 256 color/1 palette mode).

      Bit   Expl.
      0-9   Tile Number     (0-1023) (a bit less in 256 color mode, because
                               there'd be otherwise no room for the bg map)
      10    Horizontal Flip (0=Normal, 1=Mirrored)
      11    Vertical Flip   (0=Normal, 1=Mirrored)
      12-15 Palette Number  (0-15)    (Not used in 256 color/1 palette mode)

A Text BG Map always consists of 32x32 entries (256x256 pixels), 400h entries = 800h bytes. However, depending on the BG Size, one, two, or four of these Maps may be used together, allowing to create backgrounds of 256x256, 512x256, 256x512, or 512x512 pixels, if so, the first map (SC0) is located at base+0, the next map (SC1) at base+800h, and so on.
Rotation/Scaling BG Screen (1 byte per entry)
In this mode, only 256 tiles can be used. There are no x/y-flip attributes, the color depth is always 256 colors/1 palette.

      Bit   Expl.
      0-7   Tile Number     (0-255)

The dimensions of Rotation/Scaling BG Maps depend on the BG size. For size 0-3 that are: 16x16 tiles (128x128 pixels), 32x32 tiles (256x256 pixels), 64x64 tiles (512x512 pixels), or 128x128 tiles (1024x1024 pixels).
The size and VRAM base address of the separate BG maps for BG0-3 are set up by BG0CNT-BG3CNT registers.

LCD VRAM Bitmap BG Modes

In BG Modes 3-5 the background is defined in form of a bitmap (unlike as for Tile/Map based BG modes). Bitmaps are implemented as BG2, with Rotation/Scaling support. As bitmap modes are occupying 80KBytes of BG memory, only 16KBytes of VRAM can be used for OBJ tiles.
BG Mode 3 - 240x160 pixels, 32768 colors
Two bytes are associated to each pixel, directly defining one of the 32768 colors (without using palette data, and thus not supporting a 'transparent' BG color).

      Bit   Expl.
      0-4   Red Intensity   (0-31)
      5-9   Green Intensity (0-31)
      10-14 Blue Intensity  (0-31)
      15    Not used in GBA Mode (in NDS Mode: Alpha=0=Transparent, Alpha=1=Normal)

The first 480 bytes define the topmost line, the next 480 the next line, and so on. The background occupies 75 KBytes (06000000-06012BFF), most of the 80 Kbytes BG area, not allowing to redraw an invisible second frame in background, so this mode is mostly recommended for still images only.
BG Mode 4 - 240x160 pixels, 256 colors (out of 32768 colors)
One byte is associated to each pixel, selecting one of the 256 palette entries. Color 0 (backdrop) is transparent, and OBJs may be displayed behind the bitmap.
The first 240 bytes define the topmost line, the next 240 the next line, and so on. The background occupies 37.5 KBytes, allowing two frames to be used (06000000-060095FF for Frame 0, and 0600A000-060135FF for Frame 1).
BG Mode 5 - 160x128 pixels, 32768 colors
Colors are defined as for Mode 3 (see above), but horizontal and vertical size are cut down to 160x128 pixels only - smaller than the physical dimensions of the LCD screen.
The background occupies exactly 40 KBytes, so that BG VRAM may be split into two frames (06000000-06009FFF for Frame 0, and 0600A000-06013FFF for Frame 1).
In BG modes 4,5, one Frame may be displayed (selected by DISPCNT Bit 4), the other Frame is invisible and may be redrawn in background.

LCD OBJ - Overview

General
Objects (OBJs) are moveable sprites. Up to 128 OBJs (of any size, up to 64x64 dots each) can be displayed per screen, and under best circumstances up to 128 OBJs (of small 8x8 dots size) can be displayed per horizontal display line.
Maximum Number of Sprites per Line
The total available OBJ rendering cycles per line are

      1210  (=304*4-6)   If "H-Blank Interval Free" bit in DISPCNT register is 0
      954   (=240*4-6)   If "H-Blank Interval Free" bit in DISPCNT register is 1

The required rendering cycles are (depending on horizontal OBJ size)

      Cycles per <n> Pixels    OBJ Type              OBJ Type Screen Pixel Range
      n*1 cycles               Normal OBJs           8..64 pixels
      10+n*2 cycles            Rotation/Scaling OBJs 8..64 pixels   (area clipped)
      10+n*2 cycles            Rotation/Scaling OBJs 16..128 pixels (double size)

Caution:
The maximum number of OBJs per line is also affected by undisplayed (offscreen) OBJs which are having higher priority than displayed OBJs.
To avoid this, move displayed OBJs to the begin of OAM memory (ie. OBJ0 has highest priority, OBJ127 lowest).
Otherwise (in case that the program logic expects OBJs at fixed positions in OAM) at least take care to set the OBJ size of undisplayed OBJs to 8x8 with Rotation/Scaling disabled (this reduces the overload).
Does the above also apply for VERTICALLY OFFSCREEN (or VERTICALLY not on CURRENT LINE) sprites ?
VRAM - Character Data
OBJs are always combined of one or more 8x8 pixel Tiles (much like BG Tiles in BG Modes 0-2). However, OBJ Tiles are stored in a separate area in VRAM: 06010000-06017FFF (32 KBytes) in BG Mode 0-2, or 06014000-06017FFF (16 KBytes) in BG Mode 3-5.
Depending on the size of the above area (16K or 32K), and on the OBJ color depth (4bit or 8bit), 256-1024 8x8 dots OBJ Tiles can be defined.
OAM - Object Attribute Memory
This memory area contains Attributes which specify position, size, color depth, etc. appearance for each of the 128 OBJs. Additionally, it contains 32 OBJ Rotation/Scaling Parameter groups. OAM is located at 07000000-070003FF (sized 1 KByte).

LCD OBJ - OAM Attributes

OBJ Attributes
There are 128 entries in OAM for each OBJ0-OBJ127. Each entry consists of 6 bytes (three 16bit Attributes). Attributes for OBJ0 are located at 07000000, for OBJ1 at 07000008, OBJ2 at 07000010, and so on.
As you can see, there are blank spaces at 07000006, 0700000E, 07000016, etc. - these 16bit values are used for OBJ Rotation/Scaling (as described in the next chapter) - they are not directly related to the separate OBJs.
OBJ Attribute 0 (R/W)

      Bit   Expl.
      0-7   Y-Coordinate           (0-255)
      8     Rotation/Scaling Flag  (0=Off, 1=On)
      When Rotation/Scaling used (Attribute 0, bit 8 set):
        9     Double-Size Flag     (0=Normal, 1=Double)
      When Rotation/Scaling not used (Attribute 0, bit 8 cleared):
        9     OBJ Disable          (0=Normal, 1=Not displayed)
      10-11 OBJ Mode  (0=Normal, 1=Semi-Transparent, 2=OBJ Window, 3=Prohibited)
      12    OBJ Mosaic             (0=Off, 1=On)
      13    Colors/Palettes        (0=16/16, 1=256/1)
      14-15 OBJ Shape              (0=Square,1=Horizontal,2=Vertical,3=Prohibited)

Caution: A very large OBJ (of 128 pixels vertically, ie. a 64 pixels OBJ in a Double Size area) located at Y>128 will be treated as at Y>-128, the OBJ is then displayed parts offscreen at the TOP of the display, it is then NOT displayed at the bottom.
OBJ Attribute 1 (R/W)

      Bit   Expl.
      0-8   X-Coordinate           (0-511)
      When Rotation/Scaling used (Attribute 0, bit 8 set):
        9-13  Rotation/Scaling Parameter Selection (0-31)
              (Selects one of the 32 Rotation/Scaling Parameters that
              can be defined in OAM, for details read next chapter.)
      When Rotation/Scaling not used (Attribute 0, bit 8 cleared):
        9-11  Not used
        12    Horizontal Flip      (0=Normal, 1=Mirrored)
        13    Vertical Flip        (0=Normal, 1=Mirrored)
      14-15 OBJ Size               (0..3, depends on OBJ Shape, see Attr 0)
              Size  Square   Horizontal  Vertical
              0     8x8      16x8        8x16
              1     16x16    32x8        8x32
              2     32x32    32x16       16x32
              3     64x64    64x32       32x64

OBJ Attribute 2 (R/W)

      Bit   Expl.
      0-9   Character Name          (0-1023=Tile Number)
      10-11 Priority relative to BG (0-3; 0=Highest)
      12-15 Palette Number   (0-15) (Not used in 256 color/1 palette mode)

Notes:
OBJ Mode
The OBJ Mode may be Normal, Semi-Transparent, or OBJ Window.
Semi-Transparent means that the OBJ is used as 'Alpha Blending 1st Target' (regardless of BLDCNT register, for details see chapter about Color Special Effects).
OBJ Window means that the OBJ is not displayed, instead, dots with non-zero color are used as mask for the OBJ Window, see DISPCNT and WINOUT for details.
OBJ Tile Number
There are two situations which may divide the amount of available tiles by two (by four if both situations apply):
1. When using the 256 Colors/1 Palette mode, only each second tile may be used, the lower bit of the tile number should be zero (in 2-dimensional mapping mode, the bit is completely ignored).
2. When using BG Mode 3-5 (Bitmap Modes), only tile numbers 512-1023 may be used. That is because lower 16K of OBJ memory are used for BG. Attempts to use tiles 0-511 are ignored (not displayed).
Priority
In case that the 'Priority relative to BG' is the same than the priority of one of the background layers, then the OBJ becomes higher priority and is displayed on top of that BG layer.
Caution: Take care not to mess up BG Priority and OBJ priority. For example, the following would cause garbage to be displayed:

      OBJ No. 0 with Priority relative to BG=1   ;hi OBJ prio, lo BG prio
      OBJ No. 1 with Priority relative to BG=0   ;lo OBJ prio, hi BG prio

That is, OBJ0 is always having priority above OBJ1-127, so assigning a lower BG Priority to OBJ0 than for OBJ1-127 would be a bad idea.

LCD OBJ - OAM Rotation/Scaling Parameters

As described in the previous chapter, there are blank spaces between each of the 128 OBJ Attribute Fields in OAM memory. These 128 16bit gaps are used to store OBJ Rotation/Scaling Parameters.
Location of Rotation/Scaling Parameters in OAM
Four 16bit parameters (PA,PB,PC,PD) are required to define a complete group of Rotation/Scaling data. These are spread across OAM as such:

      1st Group - PA=07000006, PB=0700000E, PC=07000016, PD=0700001E
      2nd Group - PA=07000026, PB=0700002E, PC=07000036, PD=0700003E
      etc.

By using all blank space (128 x 16bit), up to 32 of these groups (4 x 16bit each) can be defined in OAM.
OBJ Rotation/Scaling PA,PB,PC,PD Parameters (R/W)
Each OBJ that uses Rotation/Scaling may select between any of the above 32 parameter groups. For details, refer to the previous chapter about OBJ Attributes.
The meaning of the separate PA,PB,PC,PD values is identical as for BG, for details read the chapter about BG Rotation/Scaling.
OBJ Reference Point & Rotation Center
The OBJ Reference Point is the upper left of the OBJ, ie. OBJ X/Y coordinates: X+0, Y+0.
The OBJ Rotation Center is always (or should be usually?) in the middle of the object, ie. for a 8x32 pixel OBJ, this would be at the OBJ X/Y coordinates: X+4, and Y+16.
OBJ Double-Size Bit (for OBJs that use Rotation/Scaling)
When Double-Size is zero: The sprite is rotated, and then display inside of the normal-sized (not rotated) rectangular area - the edges of the rotated sprite will become invisible if they reach outside of that area.
When Double-Size is set: The sprite is rotated, and then display inside of the double-sized (not rotated) rectangular area - this ensures that the edges of the rotated sprite remain visible even if they would reach outside of the normal-sized area. (Except that, for example, rotating a 8x32 pixel sprite by 90 degrees would still cut off parts of the sprite as the double-size area isn't large enough.)

LCD OBJ - VRAM Character (Tile) Mapping

Each OBJ tile consists of 8x8 dots, however, bigger OBJs can be displayed by combining several 8x8 tiles. The horizontal and vertical size for each OBJ may be separately defined in OAM, possible H/V sizes are 8,16,32,64 dots - allowing 'square' OBJs to be used (such like 8x8, 16x16, etc) as well as 'rectangular' OBJs (such like 8x32, 64x16, etc.)
When displaying an OBJ that contains of more than one 8x8 tile, one of the following two mapping modes can be used. In either case, the tile number of the upperleft tile must be specified in OAM memory.
Two Dimensional Character Mapping (DISPCNT Bit 6 cleared)
This mapping mode assumes that the 1024 OBJ tiles are arranged as a matrix of 32x32 tiles / 256x256 pixels (In 256 color mode: 16x32 tiles / 128x256 pixels). Ie. the upper row of this matrix contains tiles 00h-1Fh, the next row tiles 20h-3Fh, and so on.
For example, when displaying a 16x16 pixel OBJ, with tile number set to 04h; The upper row of the OBJ will consist of tile 04h and 05h, the next row of 24h and 25h. (In 256 color mode: 04h and 06h, 24h and 26h.)
One Dimensional Character Mapping (DISPCNT Bit 6 set)
In this mode, tiles are mapped each after each other from 00h-3FFh.
Using the same example as above, the upper row of the OBJ will consist of tile 04h and 05h, the next row of tile 06h and 07h. (In 256 color mode: 04h and 06h, 08h and 0Ah.)

LCD Color Palettes

Color Palette RAM
BG and OBJ palettes are using separate memory regions:

      05000000-050001FF - BG Palette RAM (512 bytes, 256 colors)
      05000200-050003FF - OBJ Palette RAM (512 bytes, 256 colors)

Each BG and OBJ palette RAM may be either split into 16 palettes with 16 colors each, or may be used as a single palette with 256 colors.
Note that some OBJs may access palette RAM in 16 color mode, while other OBJs may use 256 color mode at the same time. Same for BG0-BG3 layers.
Transparent Colors
Color 0 of all BG and OBJ palettes is transparent. Even though palettes are described as 16 (256) color palettes, only 15 (255) colors are actually visible.
Backdrop Color
Color 0 of BG Palette 0 is used as backdrop color. This color is displayed if an area of the screen is not covered by any non-transparent BG or OBJ dots.
Color Definitions
Each color occupies two bytes (same as for 32768 color BG modes):

      Bit   Expl.
      0-4   Red Intensity   (0-31)
      5-9   Green Intensity (0-31)
      10-14 Blue Intensity  (0-31)
      15    Not used

Intensities
Under normal circumstances (light source/viewing angle), the intensities 0-14 are practically all black, and only intensities 15-31 are resulting in visible medium..bright colors.
Note: The intensity problem appears in the 8bit CGB "compatibility" mode either. The original CGB display produced the opposite effect: Intensities 0-14 resulted in dark..medium colors, and intensities 15-31 resulted in bright colors. Any "medium" colors of CGB games will appear invisible/black on GBA hardware, and only very bright colors will be visible.

LCD Dimensions and Timings

Horizontal Dimensions
The drawing time for each dot is 4 CPU cycles.

      Visible     240 dots,  57.221 us,    960 cycles - 78% of h-time
      H-Blanking   68 dots,  16.212 us,    272 cycles - 22% of h-time
      Total       308 dots,  73.433 us,   1232 cycles - ca. 13.620 kHz

VRAM and Palette RAM may be accessed during H-Blanking. OAM can accessed only if "H-Blank Interval Free" bit in DISPCNT register is set.
Vertical Dimensions

      Visible (*) 160 lines, 11.749 ms, 197120 cycles - 70% of v-time
      V-Blanking   68 lines,  4.994 ms,  83776 cycles - 30% of v-time
      Total       228 lines, 16.743 ms, 280896 cycles - ca. 59.737 Hz

All VRAM, OAM, and Palette RAM may be accessed during V-Blanking.
Note that no H-Blank interrupts are generated within V-Blank period.
System Clock
The system clock is 16.78MHz (16*1024*1024 Hz), one cycle is thus approx. 59.59ns.
(*) Even though vertical screen size is 160 lines, the upper 8 lines are not <really> visible, these lines are covered by a shadow when holding the GBA orientated towards a light source, the lines are effectively black - and should not be used to display important information.
Interlace
The LCD display is using some sort of interlace in which even scanlines are dimmed in each second frame, and odd scanlines are dimmed in each other frame (it does always render ALL lines in ALL frames, but half of them are dimmed).
The effect can be seen when displaying some horizontal lines in each second frame, and hiding them in each other frame: the hardware will randomly show the lines in dimmed or non-dimmed form (depending on whether the test was started in an even or odd frame).
Unknown if it's possible to determine the even/off frame state by software (or possibly to reset the hardware to this or that state by software).
Note: The NDS is applying some sort of frameskip to GBA games, about every 3 seconds there will by a missing (or maybe: inserted) frame, ie. a GBA game that is updating the display in sync with GBA interlace will get offsync on NDS consoles.

GBA Sound Controller

The GBA supplies four 'analogue' sound channels for Tone and Noise (mostly compatible to CGB sound), as well as two 'digital' sound channels (which can be used to replay 8bit DMA sample data).
GBA Sound Channel 1 - Tone & Sweep
GBA Sound Channel 2 - Tone
GBA Sound Channel 3 - Wave Output
GBA Sound Channel 4 - Noise
GBA Sound Channel A and B - DMA Sound
GBA Sound Control Registers
GBA Comparison of CGB and GBA Sound
The GBA includes only a single (mono) speaker built-in, each channel may be output to either left and/or right channels by using the external line-out connector (for stereo headphones, etc).

GBA Sound Channel 1 - Tone & Sweep

4000060h - SOUND1CNT_L (NR10) - Channel 1 Sweep register (R/W)

      Bit        Expl.
      0-2   R/W  Number of sweep shift      (n=0-7)
      3     R/W  Sweep Frequency Direction  (0=Increase, 1=Decrease)
      4-6   R/W  Sweep Time; units of 7.8ms (0-7, min=7.8ms, max=54.7ms)
      7-15  -    Not used

Sweep is disabled by setting Sweep Time to zero, if so, the direction bit should be set.
The change of frequency (NR13,NR14) at each shift is calculated by the following formula where X(0) is initial freq & X(t-1) is last freq:

      X(t) = X(t-1) +/- X(t-1)/2^n

4000062h - SOUND1CNT_H (NR11, NR12) - Channel 1 Duty/Len/Envelope (R/W)

      Bit        Expl.
      0-5   W    Sound length; units of (64-n)/256s  (0-63)
      6-7   R/W  Wave Pattern Duty                   (0-3, see below)
      8-10  R/W  Envelope Step-Time; units of n/64s  (1-7, 0=No Envelope)
      11    R/W  Envelope Direction                  (0=Decrease, 1=Increase)
      12-15 R/W  Initial Volume of envelope          (1-15, 0=No Sound)

Wave Duty:

      0: 12.5% ( -_______-_______-_______ )
      1: 25%   ( --______--______--______ )
      2: 50%   ( ----____----____----____ ) (normal)
      3: 75%   ( ------__------__------__ )

The Length value is used only if Bit 6 in NR14 is set.
4000064h - SOUND1CNT_X (NR13, NR14) - Channel 1 Frequency/Control (R/W)

      Bit        Expl.
      0-10  W    Frequency; 131072/(2048-n)Hz  (0-2047)
      11-13 -    Not used
      14    R/W  Length Flag  (1=Stop output when length in NR11 expires)
      15    W    Initial      (1=Restart Sound)
      16-31 -    Not used

GBA Sound Channel 2 - Tone

This sound channel works exactly as channel 1, except that it doesn't have a Tone Envelope/Sweep Register.
4000068h - SOUND2CNT_L (NR21, NR22) - Channel 2 Duty/Length/Envelope (R/W)
400006Ah - Not used
400006Ch - SOUND2CNT_H (NR23, NR24) - Channel 2 Frequency/Control (R/W)
For details, refer to channel 1 description.

GBA Sound Channel 3 - Wave Output

This channel can be used to output digital sound, the length of the sample buffer (Wave RAM) can be either 32 or 64 digits (4bit samples). This sound channel can be also used to output normal tones when initializing the Wave RAM by a square wave. This channel doesn't have a volume envelope register.
4000070h - SOUND3CNT_L (NR30) - Channel 3 Stop/Wave RAM select (R/W)

      Bit        Expl.
      0-4   -    Not used
      5     R/W  Wave RAM Dimension   (0=One bank/32 digits, 1=Two banks/64 digits)
      6     R/W  Wave RAM Bank Number (0-1, see below)
      7     R/W  Sound Channel 3 Off  (0=Stop, 1=Playback)
      8-15  -    Not used

The currently selected Bank Number (Bit 6) will be played back, while reading/writing to/from wave RAM will address the other (not selected) bank. When dimension is set to two banks, output will start by replaying the currently selected bank.
4000072h - SOUND3CNT_H (NR31, NR32) - Channel 3 Length/Volume (R/W)

      Bit        Expl.
      0-7   W    Sound length; units of (256-n)/256s  (0-255)
      8-12  -    Not used.
      13-14 R/W  Sound Volume  (0=Mute/Zero, 1=100%, 2=50%, 3=25%)
      15    R/W  Force Volume  (0=Use above, 1=Force 75% regardless of above)

The Length value is used only if Bit 6 in NR34 is set.
4000074h - SOUND3CNT_X (NR33, NR34) - Channel 3 Frequency/Control (R/W)

      Bit        Expl.
      0-10  W    Sample Rate; 2097152/(2048-n) Hz   (0-2047)
      11-13 -    Not used
      14    R/W  Length Flag  (1=Stop output when length in NR31 expires)
      15    W    Initial      (1=Restart Sound)
      16-31 -    Not used

The above sample rate specifies the number of wave RAM digits per second, the actual tone frequency depends on the wave RAM content, for example:

      Wave RAM, single bank 32 digits   Tone Frequency
      FFFFFFFFFFFFFFFF0000000000000000  65536/(2048-n) Hz
      FFFFFFFF00000000FFFFFFFF00000000  131072/(2048-n) Hz
      FFFF0000FFFF0000FFFF0000FFFF0000  262144/(2048-n) Hz
      FF00FF00FF00FF00FF00FF00FF00FF00  524288/(2048-n) Hz
      F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0  1048576/(2048-n) Hz

4000090h - WAVE_RAM0_L - Channel 3 Wave Pattern RAM (W/R)
4000092h - WAVE_RAM0_H - Channel 3 Wave Pattern RAM (W/R)
4000094h - WAVE_RAM1_L - Channel 3 Wave Pattern RAM (W/R)
4000096h - WAVE_RAM1_H - Channel 3 Wave Pattern RAM (W/R)
4000098h - WAVE_RAM2_L - Channel 3 Wave Pattern RAM (W/R)
400009Ah - WAVE_RAM2_H - Channel 3 Wave Pattern RAM (W/R)
400009Ch - WAVE_RAM3_L - Channel 3 Wave Pattern RAM (W/R)
400009Eh - WAVE_RAM3_H - Channel 3 Wave Pattern RAM (W/R)
This area contains 16 bytes (32 x 4bits) Wave Pattern data which is output by channel 3. Data is played back ordered as follows: MSBs of 1st byte, followed by LSBs of 1st byte, followed by MSBs of 2nd byte, and so on - this results in a confusing ordering when filling Wave RAM in units of 16bit data - ie. samples would be then located in Bits 4-7, 0-3, 12-15, 8-11.
In the GBA, two Wave Patterns exists (each 32 x 4bits), either one may be played (as selected in NR30 register), the other bank may be accessed by the users. After all 32 samples have been played, output of the same bank (or other bank, as specified in NR30) will be automatically restarted.
Internally, Wave RAM is a giant shift-register, there is no pointer which is addressing the currently played digit. Instead, the entire 128 bits are shifted, and the 4 least significant bits are output.
Thus, when reading from Wave RAM, data might have changed its position. And, when writing to Wave RAM all data should be updated (it'd be no good idea to assume that old data is still located at the same position where it has been written to previously).

GBA Sound Channel 4 - Noise

This channel is used to output white noise. This is done by randomly switching the amplitude between high and low at a given frequency. Depending on the frequency the noise will appear 'harder' or 'softer'.
It is also possible to influence the function of the random generator, so the that the output becomes more regular, resulting in a limited ability to output Tone instead of Noise.
4000078h - SOUND4CNT_L (NR41, NR42) - Channel 4 Length/Envelope (R/W)

      Bit        Expl.
      0-5   W    Sound length; units of (64-n)/256s  (0-63)
      6-7   -    Not used
      8-10  R/W  Envelope Step-Time; units of n/64s  (1-7, 0=No Envelope)
      11    R/W  Envelope Direction                  (0=Decrease, 1=Increase)
      12-15 R/W  Initial Volume of envelope          (1-15, 0=No Sound)
      16-31 -    Not used

The Length value is used only if Bit 6 in NR44 is set.
400007Ch - SOUND4CNT_H (NR43, NR44) - Channel 4 Frequency/Control (R/W)
The amplitude is randomly switched between high and low at the given frequency. A higher frequency will make the noise to appear 'softer'.
When Bit 3 is set, the output will become more regular, and some frequencies will sound more like Tone than Noise.

      Bit        Expl.
      0-2   R/W  Dividing Ratio of Frequencies (r)
      3     R/W  Counter Step/Width (0=15 bits, 1=7 bits)
      4-7   R/W  Shift Clock Frequency (s)
      8-13  -    Not used
      14    R/W  Length Flag  (1=Stop output when length in NR41 expires)
      15    W    Initial      (1=Restart Sound)
      16-31 -    Not used

Frequency = 524288 Hz / r / 2^(s+1) ;For r=0 assume r=0.5 instead
Noise Random Generator (aka Polynomial Counter)
Noise randomly switches between HIGH and LOW levels, the output levels are calculated by a shift register (X), at the selected frequency, as such:

      7bit:  X=X SHR 1, IF carry THEN Out=HIGH, X=X XOR 60h ELSE Out=LOW
      15bit: X=X SHR 1, IF carry THEN Out=HIGH, X=X XOR 6000h ELSE Out=LOW

The initial value when (re-)starting the sound is X=40h (7bit) or X=4000h (15bit). The data stream repeats after 7Fh (7bit) or 7FFFh (15bit) steps.

GBA Sound Channel A and B - DMA Sound

The GBA contains two DMA sound channels (A and B), each allowing to replay digital sound (signed 8bit data, ie. -128..+127). Data can be transferred from INTERNAL memory (not sure if EXTERNAL memory works also ?) to FIFO by using DMA channel 1 or 2, the sample rate is generated by using one of the Timers.
40000A0h - FIFO_A_L - Sound A FIFO, Data 0 and Data 1 (W)
40000A2h - FIFO_A_H - Sound A FIFO, Data 2 and Data 3 (W)
These two registers may receive 32bit (4 bytes) of audio data (Data 0-3, Data 0 being located in least significant byte which is replayed first).
Internally, the capacity of the FIFO is 8 x 32bit (32 bytes), allowing to buffer a small amount of samples. As the name says (First In First Out), oldest data is replayed first.
40000A4h - FIFO_B_L - Sound B FIFO, Data 0 and Data 1 (W)
40000A6h - FIFO_B_H - Sound B FIFO, Data 2 and Data 3 (W)
Same as above, for Sound B.
Initializing DMA-Sound Playback
- Select Timer 0 or 1 in SOUNDCNT_H control register.
- Clear the FIFO.
- Manually write a sample byte to the FIFO.
- Initialize transfer mode for DMA 1 or 2.
- Initialize DMA Sound settings in sound control register.
- Start the timer.
DMA-Sound Playback Procedure
The pseudo-procedure below is automatically repeated.

      If Timer overflows then
        Move 8bit data from FIFO to sound circuit.
        If FIFO contains only 4 x 32bits (16 bytes) then
          Request more data per DMA
          Receive 4 x 32bit (16 bytes) per DMA
        Endif
      Endif

This playback mechanism will be repeated forever, regardless of the actual length of the sample buffer.
Synchronizing Sample Buffers
The buffer-end may be determined by counting sound Timer IRQs (each sample byte), or sound DMA IRQs (each 16th sample byte). Both methods would require a lot of CPU time (IRQ processing), and both would fail if interrupts are disabled for a longer period.
Better solutions would be to synchronize the sample rate/buffer length with V-blanks, or to use a second timer (in count up/slave mode) which produces an IRQ after the desired number of samples.
The Sample Rate
The GBA hardware does internally re-sample all sound output to 32.768kHz (default SOUNDBIAS setting). It'd thus do not make much sense to use higher DMA/Timer rates. Best re-sampling accuracy can be gained by using DMA/Timer rates of 32.768kHz, 16.384kHz, or 8.192kHz (ie. fragments of the physical output rate).

GBA Sound Control Registers

4000080h - SOUNDCNT_L (NR50, NR51) - Channel L/R Volume/Enable (R/W)

      Bit        Expl.
      0-2   R/W  Sound 1-4 Master Volume RIGHT (0-7)
      3     -    Not used
      4-6   R/W  Sound 1-4 Master Volume LEFT (0-7)
      7     -    Not used
      8-11  R/W  Sound 1-4 Enable Flags RIGHT (each Bit 8-11, 0=Disable, 1=Enable)
      12-15 R/W  Sound 1-4 Enable Flags LEFT (each Bit 12-15, 0=Disable, 1=Enable)

4000082h - SOUNDCNT_H (GBA only) - DMA Sound Control/Mixing (R/W)

      Bit        Expl.
      0-1   R/W  Sound # 1-4 Volume   (0=25%, 1=50%, 2=100%, 3=Prohibited)
      2     R/W  DMA Sound A Volume   (0=50%, 1=100%)
      3     R/W  DMA Sound B Volume   (0=50%, 1=100%)
      4-7   -    Not used
      8     R/W  DMA Sound A Enable RIGHT (0=Disable, 1=Enable)
      9     R/W  DMA Sound A Enable LEFT  (0=Disable, 1=Enable)
      10    R/W  DMA Sound A Timer Select (0=Timer 0, 1=Timer 1)
      11    W?   DMA Sound A Reset FIFO   (1=Reset)
      12    R/W  DMA Sound B Enable RIGHT (0=Disable, 1=Enable)
      13    R/W  DMA Sound B Enable LEFT  (0=Disable, 1=Enable)
      14    R/W  DMA Sound B Timer Select (0=Timer 0, 1=Timer 1)
      15    W?   DMA Sound B Reset FIFO   (1=Reset)

4000084h - SOUNDCNT_X (NR52) - Sound on/off (R/W)
Bits 0-3 are automatically set when starting sound output, and are automatically cleared when a sound ends. (Ie. when the length expires, as far as length is enabled. The bits are NOT reset when an volume envelope ends.)

      Bit        Expl.
      0     R    Sound 1 ON flag (Read Only)
      1     R    Sound 2 ON flag (Read Only)
      2     R    Sound 3 ON flag (Read Only)
      3     R    Sound 4 ON flag (Read Only)
      4-6   -    Not used
      7     R/W  PSG/FIFO Master Enable (0=Disable, 1=Enable) (Read/Write)
      8-31  -    Not used

While Bit 7 is cleared, both PSG and FIFO sounds are disabled, and all PSG registers at 4000060h..4000081h are reset to zero (and must be re-initialized after re-enabling sound). However, registers 4000082h and 4000088h are kept read/write-able (of which, 4000082h has no function when sound is off, whilst 4000088h does work even when sound is off).
4000088h - SOUNDBIAS - Sound PWM Control (R/W, see below)
This register controls the final sound output. The default setting is 0200h, it is normally not required to change this value.

      Bit        Expl.
      0     -    Not used
      1-9   R/W  Bias Level (Default=100h, converting signed samples into unsigned)
      10-13 -    Not used
      14-15 R/W  Amplitude Resolution/Sampling Cycle (Default=0, see below)
      16-31 -    Not used

Amplitude Resolution/Sampling Cycle (0-3):

      0  9bit / 32.768kHz   (Default, best for DMA channels A,B)
      1  8bit / 65.536kHz
      2  7bit / 131.072kHz
      3  6bit / 262.144kHz  (Best for PSG channels 1-4)

For more information on this register, read the descriptions below.
400008Ch - Not used
400008Eh - Not used
Max Output Levels (with max volume settings)
Each of the two FIFOs can span the FULL output range (+/-200h).
Each of the four PSGs can span one QUARTER of the output range (+/-80h).
The current output levels of all six channels are added together by hardware.
So together, the FIFOs and PSGs, could reach THRICE the range (+/-600h).
The BIAS value is added to that signed value. With default BIAS (200h), the possible range becomes -400h..+800h, however, values that exceed the unsigned 10bit output range of 0..3FFh are clipped to MinMax(0,3FFh).
Resampling to 32.768kHz / 9bit (default)
The PSG channels 1-4 are internally generated at 262.144kHz, and DMA sound A-B could be theoretically generated at timer rates up to 16.78MHz. However, the final sound output is resampled to a rate of 32.768kHz, at 9bit depth (the above 10bit value, divided by two). If necessary, rates higher than 32.768kHz can be selected in the SOUNDBIAS register, that would result in a depth smaller than 9bit though.
PWM (Pulse Width Modulation) Output 16.78MHz / 1bit
Okay, now comes the actual output. The GBA can output only two voltages (low and high), these 'bits' are output at system clock speed (16.78MHz). If using the default 32.768kHz sampling rate, then 512 bits are output per sample (512*32K=16M). Each sample value (9bit range, N=0..511), would be then output as N low bits, followed by 512-N high bits. The resulting 'noise' is smoothed down by capacitors, by the speaker, and by human hearing, so that it will effectively sound like clean D/A converted 9bit voltages at 32kHz sampling rate.
Changing the BIAS Level
Normally use 200h for clean sound output. A value of 000h might make sense during periods when no sound is output (causing the PWM circuit to output low-bits only, which is eventually reducing the power consumption, and/or preventing 32KHz noise). Note: Using the SoundBias function (SWI 19h) allows to change the level by slowly incrementing or decrementing it (without hard scratch noise).
Low Power Mode
When not using sound output, power consumption can be reduced by setting both 4000084h (PSG/FIFO) and 4000088h (BIAS) to zero.

GBA Comparison of CGB and GBA Sound

The GBA sound controller is mostly the same than that of older monochrome gameboy and CGB. The following changes have been done:
New Sound Channels
Two new sound channels have been added that may be used to replay 8bit digital sound. Sample rate and sample data must be supplied by using a Timer and a DMA channel.
New Control Registers
The SOUNDCNT_H register controls the new DMA channels - as well as mixing with the four old channels. The SOUNDBIAS register controls the final sound output.
Sound Channel 3 Changes
The length of the Wave RAM is doubled by dividing it into two banks of 32 digits each, either one or both banks may be replayed (one after each other), for details check NR30 Bit 5-6. Optionally, the sound may be output at 75% volume, for details check NR32 Bit 7.
Changed Control Registers
NR50 is not supporting Vin signals (that's been an external sound input from cartridge).
Changed I/O Addresses
The GBAs sound register are located at 04000060-040000AE instead of at FF10-FF3F as in CGB and monochrome gameboy. However, note that there have been new blank spaces inserted between some of the separate registers - therefore it is NOT possible to port CGB software to GBA just by changing the sound base address.
Accessing I/O Registers
In some cases two of the old 8bit registers are packed into a 16bit register and may be accessed as such.

GBA Timers

The GBA includes four incrementing 16bit timers.
Timer 0 and 1 can be used to supply the sample rate for DMA sound channel A and/or B.
4000100h - TM0CNT_L - Timer 0 Counter/Reload (R/W)
4000104h - TM1CNT_L - Timer 1 Counter/Reload (R/W)
4000108h - TM2CNT_L - Timer 2 Counter/Reload (R/W)
400010Ch - TM3CNT_L - Timer 3 Counter/Reload (R/W)
Writing to these registers initializes the <reload> value (but does not directly affect the current counter value). Reading returns the current <counter> value (or the recent/frozen counter value if the timer has been stopped).
The reload value is copied into the counter only upon following two situations: Automatically upon timer overflows, or when the timer start bit becomes changed from 0 to 1.
Note: When simultaneously changing the start bit from 0 to 1, and setting the reload value at the same time (by a single 32bit I/O operation), then the newly written reload value is recognized as new counter value.
4000102h - TM0CNT_H - Timer 0 Control (R/W)
4000106h - TM1CNT_H - Timer 1 Control (R/W)
400010Ah - TM2CNT_H - Timer 2 Control (R/W)
400010Eh - TM3CNT_H - Timer 3 Control (R/W)

      Bit   Expl.
      0-1   Prescaler Selection (0=F/1, 1=F/64, 2=F/256, 3=F/1024)
      2     Count-up Timing   (0=Normal, 1=See below)  ;Not used in TM0CNT_H
      3-5   Not used
      6     Timer IRQ Enable  (0=Disable, 1=IRQ on Timer overflow)
      7     Timer Start/Stop  (0=Stop, 1=Operate)
      8-15  Not used

When Count-up Timing is enabled, the prescaler value is ignored, instead the time is incremented each time when the previous counter overflows. This function cannot be used for Timer 0 (as it is the first timer).
F = System Clock (16.78MHz).

GBA DMA Transfers

Overview
The GBA includes four DMA channels, the highest priority is assigned to DMA0, followed by DMA1, DMA2, and DMA3. DMA Channels with lower priority are paused until channels with higher priority have completed.
The CPU is paused when DMA transfers are active, however, the CPU is operating during the periods when Sound/Blanking DMA transfers are paused.
Special features of the separate DMA channels
DMA0 - highest priority, best for timing critical transfers (eg. HBlank DMA).
DMA1 and DMA2 - can be used to feed digital sample data to the Sound FIFOs.
DMA3 - can be used to write to Game Pak ROM/FlashROM (but not GamePak SRAM).
Beside for that, each DMA 0-3 may be used for whatever general purposes.
40000B0h,0B2h - DMA0SAD - DMA 0 Source Address (W) (internal memory)
40000BCh,0BEh - DMA1SAD - DMA 1 Source Address (W) (any memory)
40000C8h,0CAh - DMA2SAD - DMA 2 Source Address (W) (any memory)
40000D4h,0D6h - DMA3SAD - DMA 3 Source Address (W) (any memory)
The most significant address bits are ignored, only the least significant 27 or 28 bits are used (max 07FFFFFFh internal memory, or max 0FFFFFFFh any memory - except SRAM ?!).
40000B4h,0B6h - DMA0DAD - DMA 0 Destination Address (W) (internal memory)
40000C0h,0C2h - DMA1DAD - DMA 1 Destination Address (W) (internal memory)
40000CCh,0CEh - DMA2DAD - DMA 2 Destination Address (W) (internal memory)
40000D8h,0DAh - DMA3DAD - DMA 3 Destination Address (W) (any memory)
The most significant address bits are ignored, only the least significant 27 or 28 bits are used (max. 07FFFFFFh internal memory or 0FFFFFFFh any memory - except SRAM ?!).
40000B8h - DMA0CNT_L - DMA 0 Word Count (W) (14 bit, 1..4000h)
40000C4h - DMA1CNT_L - DMA 1 Word Count (W) (14 bit, 1..4000h)
40000D0h - DMA2CNT_L - DMA 2 Word Count (W) (14 bit, 1..4000h)
40000DCh - DMA3CNT_L - DMA 3 Word Count (W) (16 bit, 1..10000h)
Specifies the number of data units to be transferred, each unit is 16bit or 32bit depending on the transfer type, a value of zero is treated as max length (ie. 4000h, or 10000h for DMA3).
40000BAh - DMA0CNT_H - DMA 0 Control (R/W)
40000C6h - DMA1CNT_H - DMA 1 Control (R/W)
40000D2h - DMA2CNT_H - DMA 2 Control (R/W)
40000DEh - DMA3CNT_H - DMA 3 Control (R/W)

      Bit   Expl.
      0-4   Not used
      5-6   Dest Addr Control  (0=Increment,1=Decrement,2=Fixed,3=Increment/Reload)
      7-8   Source Adr Control (0=Increment,1=Decrement,2=Fixed,3=Prohibited)
      9     DMA Repeat                   (0=Off, 1=On) (Must be zero if Bit 11 set)
      10    DMA Transfer Type            (0=16bit, 1=32bit)
      11    Game Pak DRQ  - DMA3 only -  (0=Normal, 1=DRQ <from> Game Pak, DMA3)
      12-13 DMA Start Timing  (0=Immediately, 1=VBlank, 2=HBlank, 3=Special)
              The 'Special' setting (Start Timing=3) depends on the DMA channel:
              DMA0=Prohibited, DMA1/DMA2=Sound FIFO, DMA3=Video Capture
      14    IRQ upon end of Word Count   (0=Disable, 1=Enable)
      15    DMA Enable                   (0=Off, 1=On)

After changing the Enable bit from 0 to 1, wait 2 clock cycles before accessing any DMA related registers.
When accessing OAM (7000000h) or OBJ VRAM (6010000h) by HBlank Timing, then the "H-Blank Interval Free" bit in DISPCNT register must be set.
Source and Destination Address and Word Count Registers
The SAD, DAD, and CNT_L registers are holding the initial start addresses, and initial length. The hardware does NOT change the content of these registers during or after the transfer.
The actual transfer takes place by using internal pointer/counter registers. The initial values are copied into internal regs under the following circumstances:
Upon DMA Enable (Bit 15) changing from 0 to 1: Reloads SAD, DAD, CNT_L.
Upon Repeat: Reloads CNT_L, and optionally DAD (Increment+Reload).
DMA Repeat bit
If the Repeat bit is cleared: The Enable bit is automatically cleared after the specified number of data units has been transferred.
If the Repeat bit is set: The Enable bit remains set after the transfer, and the transfer will be restarted each time when the Start condition (eg. HBlank, Fifo) becomes true. The specified number of data units is transferred <each> time when the transfer is (re-)started. The transfer will be repeated forever, until it gets stopped by software.
Sound DMA (FIFO Timing Mode) (DMA1 and DMA2 only)
In this mode, the DMA Repeat bit must be set, and the destination address must be FIFO_A (040000A0h) or FIFO_B (040000A4h).
Upon DMA request from sound controller, 4 units of 32bits (16 bytes) are transferred (both Word Count register and DMA Transfer Type bit are ignored). The destination address will not be incremented in FIFO mode.
Keep in mind that DMA channels of higher priority may offhold sound DMA. For example, when using a 64 kHz sample rate, 16 bytes of sound DMA data are requested each 0.25ms (4 kHz), at this time another 16 bytes are still in the FIFO so that there's still 0.25ms time to satisfy the DMA request. Thus DMAs with higher priority should not be operated for longer than 0.25ms. (This problem does not arise for HBlank transfers as HBlank time is limited to 16.212us.)
Game Pak DMA
Only DMA 3 may be used to transfer data to/from Game Pak ROM or Flash ROM - it cannot access Game Pak SRAM though (as SRAM data bus is limited to 8bit units). In normal mode, DMA is requested as long until Word Count becomes zero. When setting the 'Game Pack DRQ' bit, then the cartridge must contain an external circuit which outputs a /DREQ signal. Note that there is only one pin for /DREQ and /IREQ, thus the cartridge may not supply /IREQs while using DRQ mode.
Video Capture Mode (DMA3 only)
Intended to copy a bitmap from memory (or from external hardware/camera) to VRAM. When using this transfer mode, set the repeat bit, and write the number of data units (per scanline) to the word count register. Capture works similar like HBlank DMA, however, the transfer is started when VCOUNT=2, it is then repeated each scanline, and it gets stopped when VCOUNT=162.
Transfer End
The DMA Enable flag (Bit 15) is automatically cleared upon completion of the transfer. The user may also clear this bit manually in order to stop the transfer (obviously this is possible for Sound/Blanking DMAs only, in all other cases the CPU is stopped until the transfer completes by itself).
Transfer Rate/Timing
Except for the first data unit, all units are transferred by sequential reads and writes. For n data units, the DMA transfer time is:

      2N+2(n-1)S+xI

Of which, 1N+(n-1)S are read cycles, and the other 1N+(n-1)S are write cycles, actual number of cycles depends on the waitstates and bus-width of the source and destination areas (as described in CPU Instruction Cycle Times chapter). Internal time for DMA processing is 2I (normally), or 4I (if both source and destination are in gamepak memory area).
DMA lockup when stopping while starting ???
Capture delayed, Capture Enable=AutoCleared ???

GBA Communication Ports

The GBAs Serial Port may be used in various different communication modes. Normal mode may exchange data between two GBAs (or to transfer data from master GBA to several slave GBAs in one-way direction).
Multi-player mode may exchange data between up to four GBAs. UART mode works much like a RS232 interface. JOY Bus mode uses a standardized Nintendo protocol. And General Purpose mode allows to mis-use the 'serial' port as bi-directional 4bit parallel port.
Note: The Nintendo DS does not include a Serial Port.
SIO Normal Mode
SIO Multi-Player Mode
SIO UART Mode
SIO JOY BUS Mode
SIO General-Purpose Mode
SIO Control Registers Summary
Wireless Adapter
GBA Wireless Adapter
Infrared Communication Adapters
Even though early GBA prototypes have been intended to support IR communication, this feature has been removed.
However, Nintendo is apparently considering to provide an external IR adapter (to be connected to the SIO connector, being accessed in General Purpose mode).
Also, it'd be theoretically possible to include IR ports built-in in game cartridges (as done for some older 8bit/monochrome Hudson games).

SIO Normal Mode

This mode is used to communicate between two units.
Transfer rates of 256Kbit/s or 2Mbit/s can be selected, however, the fast 2Mbit/s is intended ONLY for special hardware expansions that are DIRECTLY connected to the GBA link port (ie. without a cable being located between the GBA and expansion hardware). In normal cases, always use 256Kbit/s transfer rate which provides stable results.
Transfer lengths of 8bit or 32bit may be used, the 8bit mode is the same as for older DMG/CGB gameboys, however, the voltages for "GBA cartridges in GBAs" are different as for "DMG/CGB cartridges in DMG/CGB/GBAs", ie. it is not possible to communicate between DMG/CGB games and GBA games.
4000134h - RCNT (R) - Mode Selection, in Normal/Multiplayer/UART modes (R/W)

      Bit   Expl.
      0-3   Undocumented (current SC,SD,SI,SO state, as for General Purpose mode)
      4-8   Not used     (Should be 0, bits are read/write-able though)
      9-13  Not used     (Always 0, read only)
      14    Not used     (Should be 0, bit is read/write-able though)
      15    Must be zero (0) for Normal/Multiplayer/UART modes

4000128h - SIOCNT - SIO Control, usage in NORMAL Mode (R/W)

      Bit   Expl.
      0     Shift Clock (SC)        (0=External, 1=Internal)
      1     Internal Shift Clock    (0=256KHz, 1=2MHz)
      2     SI State (opponents SO) (0=Low, 1=High/None) --- (Read Only)
      3     SO during inactivity    (0=Low, 1=High) (applied ONLY when Bit7=0)
      4-6   Not used                (Read only, always 0 ?)
      7     Start Bit               (0=Inactive/Ready, 1=Start/Active)
      8-11  Not used                (R/W, should be 0)
      12    Transfer Length         (0=8bit, 1=32bit)
      13    Must be "0" for Normal Mode
      14    IRQ Enable              (0=Disable, 1=Want IRQ upon completion)
      15    Not used                (Read only, always 0)

The Start bit is automatically reset when the transfer completes, ie. when all 8 or 32 bits are transferred, at that time an IRQ may be generated.
400012Ah - SIODATA8 - SIO Normal Communication 8bit Data (R/W)
For 8bit normal mode. Contains 8bit data (only lower 8bit are used). Outgoing data should be written to this register before starting the transfer. During transfer, transmitted bits are shifted-out (MSB first), and received bits are shifted-in simultaneously. Upon transfer completion, the register contains the received 8bit value.
4000120h - SIODATA32_L - SIO Normal Communication lower 16bit data (R/W)
4000122h - SIODATA32_H - SIO Normal Communication upper 16bit data (R/W)
Same as above SIODATA8, for 32bit normal transfer mode respectively.
SIOCNT/RCNT must be set to 32bit normal mode <before> writing to SIODATA32.
Initialization
First, initialize RCNT register. Second, set mode/clock bits in SIOCNT with startbit cleared. For master: select internal clock, and (in most cases) specify 256KHz as transfer rate. For slave: select external clock, the local transfer rate selection is then ignored, as the transfer rate is supplied by the remote GBA (or other computer, which might supply custom transfer rates).
Third, set the startbit in SIOCNT with mode/clock bits unchanged.
Recommended Communication Procedure for SLAVE unit (external clock)
- Initialize data which is to be sent to master.
- Set Start flag.
- Set SO to LOW to indicate that master may start now.
- Wait for IRQ (or for Start bit to become zero). (Check timeout here!)
- Set SO to HIGH to indicate that we are not ready.
- Process received data.
- Repeat procedure if more data is to be transferred.
(or is so=high done automatically? would be fine - more stable - otherwise master may still need delay)
Recommended Communication Procedure for SLAVE unit (external clock)
- Initialize data which is to be sent to master.
- Set Start=0 and SO=0 (SO=LOW indicates that slave is (almost) ready).
- Set Start=1 and SO=1 (SO=HIGH indicates not ready, applied after transfer).

      (Expl. Old SO=LOW kept output until 1st clock bit received).
      (Expl. New SO=HIGH is automatically output at transfer completion).

- Set SO to LOW to indicate that master may start now.
- Wait for IRQ (or for Start bit to become zero). (Check timeout here!)
- Process received data.
- Repeat procedure if more data is to be transferred.
Recommended Communication Procedure for MASTER unit (internal clock)
- Initialize data which is to be sent to slave.
- Wait for SI to become LOW (slave ready). (Check timeout here!)
- Set Start flag.
- Wait for IRQ (or for Start bit to become zero).
- Process received data.
- Repeat procedure if more data is to be transferred.
Cable Protocol
During inactive transfer, the shift clock (SC) is high. The transmit (SO) and receive (SI) data lines may be manually controlled as described above.
When master sends SC=LOW, each master and slave must output the next outgoing data bit to SO. When master sends SC=HIGH, each master and slave must read out the opponents data bit from SI. This is repeated for each of the 8 or 32 bits, and when completed SC will be kept high again.
Transfer Rates
Either 256KHz or 2MHz rates can be selected for SC, so max 32KBytes (256Kbit) or 128KBytes (2Mbit) can be transferred per second. However, the software must process each 8bit or 32bit of transmitted data separately, so the actual transfer rate will be reduced by the time spent on handling each data unit.
Only 256KHz provides stable results in most cases (such like when linking between two GBAs). The 2MHz rate is intended for special expansion hardware (with very short wires) only.
Using Normal mode for One-Way Multiplayer communication
When using normal mode with multiplay-cables, data isn't exchanged between first and second GBA as usually. Instead, data is shifted from first to last GBA (the first GBA receives zero, because master SI is shortcut to GND).
This behaviour may be used for fast ONE-WAY data transfer from master to all other GBAs. For example (3 GBAs linked):

      Step         Sender      1st Recipient   2nd Recipient
      Transfer 1:  DATA #0 --> UNDEF      -->  UNDEF     -->
      Transfer 2:  DATA #1 --> DATA #0    -->  UNDEF     -->
      Transfer 3:  DATA #2 --> DATA #1    -->  DATA #0   -->
      Transfer 4:  DATA #3 --> DATA #2    -->  DATA #1   -->

The recipients should not output any own data, instead they should forward the previously received data to the next recipient during next transfer (just keep the incoming data unmodified in the data register).
Due to the delayed forwarding, 2nd recipient should ignore the first incoming data. After the last transfer, the sender must send one (or more) dummy data unit(s), so that the last data is forwarded to the 2nd (or further) recipient(s).

SIO Multi-Player Mode

Multi-Player mode can be used to communicate between up to 4 units.
4000134h - RCNT (R) - Mode Selection, in Normal/Multiplayer/UART modes (R/W)

      Bit   Expl.
      0-3   Undocumented (current SC,SD,SI,SO state, as for General Purpose mode)
      4-8   Not used     (Should be 0, bits are read/write-able though)
      9-13  Not used     (Always 0, read only)
      14    Not used     (Should be 0, bit is read/write-able though)
      15    Must be zero (0) for Normal/Multiplayer/UART modes

Note: Even though undocumented, many Nintendo games are using Bit 0 to test current SC state in multiplay mode.
4000128h - SIOCNT - SIO Control, usage in MULTI-PLAYER Mode (R/W)

      Bit   Expl.
      0-1   Baud Rate     (0-3: 9600,38400,57600,115200 bps)
      2     SI-Terminal   (0=Parent, 1=Child)                  (Read Only)
      3     SD-Terminal   (0=Bad connection, 1=All GBAs Ready) (Read Only)
      4-5   Multi-Player ID     (0=Parent, 1-3=1st-3rd child)  (Read Only)
      6     Multi-Player Error  (0=Normal, 1=Error)            (Read Only)
      7     Start/Busy Bit      (0=Inactive, 1=Start/Busy) (Read Only for Slaves)
      8-11  Not used            (R/W, should be 0)
      12    Must be "0" for Multi-Player mode
      13    Must be "1" for Multi-Player mode
      14    IRQ Enable          (0=Disable, 1=Want IRQ upon completion)
      15    Not used            (Read only, always 0)

The ID Bits are undefined until the first transfer has completed.
400012Ah - SIOMLT_SEND - Data Send Register (R/W)
Outgoing data (16 bit) which is to be sent to the other GBAs.
4000120h - SIOMULTI0 - SIO Multi-Player Data 0 (Parent) (R/W)
4000122h - SIOMULTI1 - SIO Multi-Player Data 1 (1st child) (R/W)
4000124h - SIOMULTI2 - SIO Multi-Player Data 2 (2nd child) (R/W)
4000126h - SIOMULTI3 - SIO Multi-Player Data 3 (3rd child) (R/W)
These registers are automatically reset to FFFFh upon transfer start.
After transfer, these registers contain incoming data (16bit each) from all remote GBAs (if any / otherwise still FFFFh), as well as the local outgoing SIOMLT_SEND data.
Ie. after the transfer, all connected GBAs will contain the same values in their SIOMULTI0-3 registers.
Initialization
- Initialize RCNT Bit 14-15 and SIOCNT Bit 12-13 to select Multi-Player mode.
- Read SIOCNT Bit 3 to verify that all GBAs are in Multi-Player mode.
- Read SIOCNT Bit 2 to detect whether this is the Parent/Master unit.
Recommended Transmission Procedure
- Write outgoing data to SIODATA_SEND.
- Master must set Start bit.
- All units must process received data in SIOMULTI0-3 when transfer completed.
- After the first successful transfer, ID Bits in SIOCNT are valid.
- If more data is to be transferred, repeat procedure.
The parent unit blindly sends data regardless of whether childs have already processed old data/supplied new data. So, parent unit might be required to insert delays between each transfer, and/or perform error checking.
Also, slave units may signalize that they are not ready by temporarily switching into another communication mode (which does not output SD High, as Multi-Player mode does during inactivity).
Transfer Protocol
Beginning
- The masters SI pin is always LOW.
- When all GBAs are in Multiplayer mode (ready) SD is HIGH.
- When master starts the transfer, it sets SC=LOW, slaves receive Busy bit.
Step A
- ID Bits in master unit are set to 0.
- Master outputs Startbit (LOW), 16bit Data, Stopbit (HIGH) through SD.
- This data is written to SIOMULTI0 of all GBAs (including master).
- Master forwards LOW from its SO to 1st childs SI.
- Transfer ends if next child does not output data after certain time.
Step B
- ID Bits in 1st child unit are set to 1.
- 1st Child outputs Startbit (LOW), 16bit Data, Stopbit (HIGH) through SD.
- This data is written to SIOMULTI1 of all GBAs (including 1st child).
- 1st child forwards LOW from its SO to 2nd childs SI.
- Transfer ends if next child does not output data after certain time.
Step C
- ID Bits in 2nd child unit are set to 2.
- 2nd Child outputs Startbit (LOW), 16bit Data, Stopbit (HIGH) through SD.
- This data is written to SIOMULTI2 of all GBAs (including 2nd child).
- 2nd child forwards LOW from its SO to 3rd childs SI.
- Transfer ends if next child does not output data after certain time.
Step D
- ID Bits in 3rd child unit are set to 3.
- 3rd Child outputs Startbit (LOW), 16bit Data, Stopbit (HIGH) through SD.
- This data is written to SIOMULTI3 of all GBAs (including 3rd child).
- Transfer ends (this was the last child).
Transfer end
- Master sets SC=HIGH, all GBAs set SO=HIGH.
- The Start/Busy bits of all GBAs are automatically cleared.
- Interrupts are requested in all GBAs (as far as enabled).
Error Bit
This bit is set when a slave did not receive SI=LOW even though SC=LOW signalized a transfer (this might happen when connecting more than 4 GBAs, or when the previous child is not connected). Also, the bit is set when a Stopbit wasn't HIGH.
The error bit may be undefined during active transfer - read only after transfer completion (the transfer continues and completes as normal even if errors have occurred for some or all GBAs).
Don't know: The bit is automatically reset/initialized with each transfer, or must be manually reset?
Transmission Time
The transmission time depends on the selected Baud rate. And on the amount of Bits (16 data bits plus start/stop bits for each GBA), delays between data for each GBA, plus final timeout (if less than 4 GBAs). That is, depending on the number of connected GBAs:

      GBAs    Bits    Delays   Timeout
      1       18      None     Yes
      2       36      1        Yes
      3       54      2        Yes
      4       72      3        None

(The average Delay and Timeout periods are unknown?)
Above is not counting the additional CPU time that must be spent on initiating and processing each transfer.
Fast One-Way Transmission
Beside for the actual SIO Multiplayer mode, you can also use SIO Normal mode for fast one-way data transfer from Master unit to all Child unit(s). See chapter about SIO Normal mode for details.

SIO UART Mode

This mode works much like a RS232 port, however, the voltages are unknown, probably 0/3V rather than +/-12V ?. SI and SO are data lines (with crossed wires), SC and SD signalize Clear to Send (with crossed wires also, which requires special cable when linking between two GBAs ?)
4000134h - RCNT (R) - Mode Selection, in Normal/Multiplayer/UART modes (R/W)

      Bit   Expl.
      0-3   Undocumented (current SC,SD,SI,SO state, as for General Purpose mode)
      4-8   Not used     (Should be 0, bits are read/write-able though)
      9-13  Not used     (Always 0, read only)
      14    Not used     (Should be 0, bit is read/write-able though)
      15    Must be zero (0) for Normal/Multiplayer/UART modes

4000128h - SCCNT_L - SIO Control, usage in UART Mode (R/W)

      Bit   Expl.
      0-1   Baud Rate  (0-3: 9600,38400,57600,115200 bps)
      2     CTS Flag   (0=Send always/blindly, 1=Send only when SC=LOW)
      3     Parity Control (0=Even, 1=Odd)
      4     Send Data Flag      (0=Not Full,  1=Full)    (Read Only)
      5     Receive Data Flag   (0=Not Empty, 1=Empty)   (Read Only)
      6     Error Flag          (0=No Error,  1=Error)   (Read Only)
      7     Data Length         (0=7bits,   1=8bits)
      8     FIFO Enable Flag    (0=Disable, 1=Enable)
      9     Parity Enable Flag  (0=Disable, 1=Enable)
      10    Send Enable Flag    (0=Disable, 1=Enable)
      11    Receive Enable Flag (0=Disable, 1=Enable)
      12    Must be "1" for UART mode
      13    Must be "1" for UART mode
      14    IRQ Enable          (0=Disable, 1=IRQ when any Bit 4/5/6 become set)
      15    Not used            (Read only, always 0)

400012Ah - SIODATA8 - usage in UART Mode (R/W)
Addresses the send/receive shift register, or (when FIFO is used) the send/receive FIFO. In either case only the lower 8bit of SIODATA8 are used, the upper 8bit are not used.
The send/receive FIFO may store up to four 8bit data units each. For example, while 1 unit is still transferred from the send shift register, it is possible to deposit another 4 units in the send FIFO, which are then automatically moved to the send shift register one after each other.
Send/Receive Enable, CTS Feedback
The receiver outputs SD=LOW (which is input as SC=LOW at the remote side) when it is ready to receive data (that is, when Receive Enable is set, and the Receive shift register (or receive FIFO) isn't full.
When CTS flag is set to always/blindly, then the sender transmits data immediately when Send Enable is set, otherwise data is transmitted only when Send Enable is set and SC is LOW.
Error Flag
The error flag is set when a bad stop bit has been received (stop bit must be 0), when a parity error has occurred (if enabled), or when new data has been completely received while the receive data register (or receive FIFO) is already full.
The error flag is automatically reset when reading from SIOCNT register.
Init & Initback
The content of the FIFO is reset when FIFO is disabled in UART mode, thus, when entering UART mode initially set FIFO=disabled.
The Send/Receive enable bits must be reset before switching from UART mode into another SIO mode!

SIO JOY BUS Mode

This communication mode uses Nintendo's standardized JOY Bus protocol. When using this communication mode, the GBA is always operated as SLAVE!
In this mode, SI and SO pins are data lines (apparently synchronized by Start/Stop bits?), SC and SD are set to low (including during active transfer?), the transfer rate is unknown?
4000134h - RCNT (R) - Mode Selection, in JOY BUS mode (R/W)

      Bit   Expl.
      0-3   Undocumented (current SC,SD,SI,SO state, as for General Purpose mode)
      4-8   Not used     (Should be 0, bits are read/write-able though)
      9-13  Not used     (Always 0, read only)
      14    Must be "1" for JOY BUS Mode
      15    Must be "1" for JOY BUS Mode

4000128h - SIOCNT - SIO Control, not used in JOY BUS Mode
This register is not used in JOY BUS mode.
4000140h - JOYCNT - JOY BUS Control Register (R/W)

      Bit   Expl.
      0     Device Reset Flag     (Command FFh)          (Read/Acknowledge)
      1     Receive Complete Flag (Command 14h or 15h?)  (Read/Acknowledge)
      2     Send Complete Flag    (Command 15h or 14h?)  (Read/Acknowledge)
      3-5   Not used
      6     IRQ when receiving a Device Reset Command  (0=Disable, 1=Enable)
      7-31  Not used

Bit 0-2 are working much like the bits in the IF register: Write a "1" bit to reset (acknowledge) the respective bit.
UNCLEAR: Interrupts can be requested for Send/Receive commands also?
4000150h - JOY_RECV_L - Receive Data Register low (R/W)
4000152h - JOY_RECV_H - Receive Data Register high (R/W)
4000154h - JOY_TRANS_L - Send Data Register low (R/W)
4000156h - JOY_TRANS_H - Send Data Register high (R/W)
Send/receive data registers.
4000158h - JOYSTAT - Receive Status Register (R/W)

      Bit   Expl.
      0     Not used
      1     Receive Status Flag   (0=Remote GBA is/was receiving) (Read Only?)
      2     Not used
      3     Send Status Flag      (1=Remote GBA is/was sending)   (Read Only?)
      4-5   General Purpose Flag  (Not assigned, may be used for whatever purpose)
      6-31  Not used

Bit 1 is automatically set when writing to local JOY_TRANS.
Bit 3 is automatically reset when reading from local JOY_RECV.
Below are the four possible commands which can be received by the GBA. Note that the GBA (slave) cannot send any commands itself, all it can do is to read incoming data, and to provide 'reply' data which may (or may not) be read out by the master unit.
Command FFh - Device Reset

      Receive FFh (Command)
      Send    00h (GBA Type number LSB (or MSB?))
      Send    04h (GBA Type number MSB (or LSB?))
      Send    XXh (lower 8bits of SIOSTAT register)

Command 00h - Type/Status Data Request

      Receive 00h (Command)
      Send    00h (GBA Type number LSB (or MSB?))
      Send    04h (GBA Type number MSB (or LSB?))
      Send    XXh (lower 8bits of SIOSTAT register)

Command 15h - GBA Data Write (to GBA)

      Receive 15h (Command)
      Receive XXh (Lower 8bits of JOY_RECV_L)
      Receive XXh (Upper 8bits of JOY_RECV_L)
      Receive XXh (Lower 8bits of JOY_RECV_H)
      Receive XXh (Upper 8bits of JOY_RECV_H)
      Send    XXh (lower 8bits of SIOSTAT register)

Command 14h - GBA Data Read (from GBA)

      Receive 14h (Command)
      Send    XXh (Lower 8bits of JOY_TRANS_L)
      Send    XXh (Upper 8bits of JOY_TRANS_L)
      Send    XXh (Lower 8bits of JOY_TRANS_H)
      Send    XXh (Upper 8bits of JOY_TRANS_H)
      Send    XXh (lower 8bits of SIOSTAT register)

SIO General-Purpose Mode

In this mode, the SIO is 'misused' as a 4bit bi-directional parallel port, each of the SI,SO,SC,SD pins may be directly controlled, each can be separately declared as input (with internal pull-up) or as output signal.
4000134h - RCNT (R) - SIO Mode, usage in GENERAL-PURPOSE Mode (R/W)
Interrupts can be requested when SI changes from HIGH to LOW, as General Purpose mode does not require a serial shift clock, this interrupt may be produced even when the GBA is in Stop (low power standby) state.

      Bit   Expl.
      0     SC Data Bit         (0=Low, 1=High)
      1     SD Data Bit         (0=Low, 1=High)
      2     SI Data Bit         (0=Low, 1=High)
      3     SO Data Bit         (0=Low, 1=High)
      4     SC Direction        (0=Input, 1=Output)
      5     SD Direction        (0=Input, 1=Output)
      6     SI Direction        (0=Input, 1=Output, but see below)
      7     SO Direction        (0=Input, 1=Output)
      8     SI Interrupt Enable (0=Disable, 1=Enable)
      9-13  Not used
      14    Must be "0" for General-Purpose Mode
      15    Must be "1" for General-Purpose or JOYBUS Mode

SI should be always used as Input to avoid problems with other hardware which does not expect data to be output there.
4000128h - SIOCNT - SIO Control, not used in GENERAL-PURPOSE Mode
This register is not used in general purpose mode. That is, the separate bits of SIOCNT still exist and are read- and/or write-able in the same manner as for Normal, Multiplay, or UART mode (depending on SIOCNT Bit 12,13), but are having no effect on data being output to the link port.

SIO Control Registers Summary

Mode Selection (by RCNT.15-14 and SIOCNT.13-12)

      R.15 R.14 S.13 S.12 Mode
      0    x    0    0    Normal 8bit
      0    x    0    1    Normal 32bit
      0    x    1    0    Multiplay 16bit
      0    x    1    1    UART (RS232)
      1    0    x    x    General Purpose
      1    1    x    x    JOY BUS

SIOCNT

      Bit    0      1    2     3      4 5 6   7     8    9      10   11
      Normal Master Rate SI/In SO/Out - - -   Start -    -      -    -
      Multi  Baud   Baud SI/In SD/In  ID# Err Start -    -      -    -
      UART   Baud   Baud CTS   Parity S R Err Bits  FIFO Parity Send Recv

GBA Wireless Adapter

GBA Wireless Adapter (AGB-015 or OXY-004)
GBA Wireless Adapter Games
GBA Wireless Adapter Login
GBA Wireless Adapter Commands
GBA Wireless Adapter Component Lists

GBA Wireless Adapter Games

GBA Wireless Adapter compatible Games

      bit Generations series (Japan only)
      Boktai 2: Solar Boy Django (Konami)
      Boktai 3: Sabata's Counterattack
      Classic NES Series: Donkey Kong
      Classic NES Series: Dr. Mario
      Classic NES Series: Ice Climber
      Classic NES Series: Pac-Man
      Classic NES Series: Super Mario Bros.
      Classic NES Series: Xevious
      Digimon Racing (Bandai) (No Wireless Adapter support in European release)
      Dragon Ball Z: Buu's Fury (Atari)
      Famicom Mini Series: #13 Balloon Fight
      Famicom Mini Series: #12 Clu Clu Land
      Famicom Mini Series: #16 Dig Dug
      Famicom Mini Series: #02 Donkey Kong
      Famicom Mini Series: #15 Dr. Mario
      Famicom Mini Series: #03 Ice Climber
      Famicom Mini Series: #18 Makaimura
      Famicom Mini Series: #08 Mappy
      Famicom Mini Series: #11 Mario Bros.
      Famicom Mini Series: #06 Pac-Man
      Famicom Mini Series: #30 SD Gundam World Scramble Wars
      Famicom Mini Series: #01 Super Mario Bros.
      Famicom Mini Series: #21 Super Mario Bros.
      Famicom Mini Series: #19 Twin Bee
      Famicom Mini Series: #14 Wrecking Crew
      Famicom Mini Series: #07 Xevious
      Hamtaro: Ham-Ham Games (Nintendo)
      Lord of the Rings: The Third Age, The (EA Games)
      Mario Golf: Advance Tour (Nintendo)
      Mario Tennis: Power Tour (Nintendo)
      Mega Man Battle Network 5: Team Protoman (Capcom)
      Mega Man Battle Network 5: Team Colonel (Capcom)
      Mega Man Battle Network 6: Cybeast Falzar
      Mega Man Battle Network 6: Cybeast Gregar
      Momotaro Dentetsu G: Make a Gold Deck! (Japan only)
      Pokemon Emerald (Nintendo)
      Pokemon FireRed (Nintendo)
      Pokemon LeafGreen (Nintendo)
      Sennen Kazoku (Japan only)
      Shrek SuperSlam
      Sonic Advance 3

GBA Wireless Adapter Login

GBA Wireless Adapter Login

      rcnt=8000h    ;\
      rcnt=80A0h    ;
      rcnt=80A2h    ; reset adapter or so
      wait          ;
      rcnt=80A0h    ;/
      siocnt=5003h  ;\set 32bit normal mode, 2MHz internal clock
      rcnt=0000h    ;/
      passes=0, index=0
     @@lop:
      passes=passes+1, if passes>32 then ERROR  ;give up (usually only 10 passses)
      recv.lo=siodata AND FFFFh    ;response from adapter
      recv.hi=siodata/10000h       ;adapter's own "NI" data
      if send.hi<>recv.lo then index=0, goto @@stuck  ;<-- fallback to index=0
      if (send.lo XOR FFFFh)<>recv.lo then goto @@stuck
      if (send.hi XOR FFFFh)<>recv.hi then goto @@stuck
      index=index+1
     @@stuck:
      send.lo=halfword[@@key_string+index*2]
      send.hi=recv.hi XOR FFFFh
      siodata=send.lo+(send.hi*10000h)
      siocnt.bit7=1                        ;<-- start transmission
      if index<4 then goto @@lop
      ret
     @@key_string db 'NINTENDO',01h,80h    ;10 bytes (5 halfwords; index=0..4)

Data exchanged during Login

                   GBA                         ADAPTER
                   xxxx494E ;\     <-->        xxxxxxxx
                   xxxx494E ; "NI" <--> "NI"/; 494EB6B1 ;\
      NOT("NI") /; B6B1494E ;/     <-->     \; 494EB6B1 ; NOT("NI")
                \; B6B1544E ;\"NT" <--> "NT"/; 544EB6B1 ;/
      NOT("NT") /; ABB1544E ;/     <-->     \; 544EABB1 ;\NOT("NT")
                \; ABB14E45 ;\"EN" <--> "EN"/; 4E45ABB1 ;/
      NOT("EN") /; B1BA4E45 ;/     <-->     \; 4E45B1BA ;\NOT("EN")
                \; B1BA4F44 ;\"DO" <--> "DO"/; 4F44B1BA ;/
      NOT("DO") /; B0BB4F44 ;/     <-->     \; 4F44B0BB ;\NOT("DO")
                \; B0BB8001 ;-fin  <-->  fin-; 8001B0BB ;/
                     \   \                      \   \
                      \   LSBs=Own               \   LSBs=Inverse of
                       \   Data.From.Gba          \   Prev.Data.From.Gba
                        \                          \
                         MSBs=Inverse of            MSBs=Own
                          Prev.Data.From.Adapter     Data.From.Adapter

GBA Wireless Adapter Commands

Wireless Command/Parameter Transmission

      GBA       Adapter
      9966ppcch 80000000h   ;-send command (cc), and num param_words (pp)
      <param01> 80000000h   ;\
      <param02> 80000000h   ; send "pp" parameter word(s), if any
      ...       ...         ;/
      80000000h 9966rraah   ;-recv ack (aa=cc+80h), and num response_words (rr)
      80000000? <reply01>   ;\
      80000000? <reply02>   ; recv "rr" response word(s), if any
      ...       ...         ;/

Wireless 32bit Transfers

      wait until [4000128h].Bit2=0  ;want SI=0
      set [4000128h].Bit3=1         ;set SO=1
      wait until [4000128h].Bit2=1  ;want SI=1
      set [4000128h].Bit3=0,Bit7=1  ;set SO=0 and start 32bit transfer

All command/param/reply transfers should be done at Internal Clock (except, Response Words for command 25h,27h,35h,37h should use External Clock).
Wireless Commands

      Cmd Para Reply Name
      10h -    -     Hello (send immediately after login)
      11h -    1     Good/Bad response to cmd 16h ?
      12h
      13h -    1
      14h
      15h
      16h 6    -     Introduce (send game/user name)
      17h 1    -     Config (send after Hello) (eg. param=003C0420h or 003C043Ch)
      18h
      19h
      1Ah
      1Bh
      1Ch -    -
      1Dh -    NN    Get Directory? (receive list of game/user names?)
      1Eh -    NN    Get Directory? (receive list of game/user names?)
      1Fh 1    -     Select Game for Download (send 16bit Game_ID)

      20h -    1
      21h -    1     Good/Bad response to cmd 1Fh ?
      22h
      23h
      24h -    -
      25h                                       ;use EXT clock!
      26h -    -
      27h -    -     Begin Download ?           ;use EXT clock!
      28h
      29h
      2Ah
      2Bh
      2Ch
      2Dh
      2Eh
      2Fh

      30h 1    -
      31h
      32h
      33h
      34h
      35h                                       ;use EXT clock!
      36h
      37h                                       ;use EXT clock!
      38h
      39h
      3Ah
      3Bh
      3Ch
      3Dh -    -     Bye (return to language select)
      3Eh
      3Fh

Special Response 996601EEh for error or so? (only at software side?)

GBA Wireless Adapter Component Lists

Main Chipset

      U1 32pin Freescale MC13190 (2.4 GHz ISM band transceiver)
      U2 48pin Freescale CT3000 or CT3001 (depending on adapter version)
      X3  2pin 9.5MHz crystal

The MC13190 is a Short-Range, Low-Power 2.4 GHz ISM band transceiver.
The processor is Motorola's 32-bit M-Core RISC engine. (?) MCT3000 (?)
See also: http://www.eetimes.com/document.asp?doc_id=1271943
Version with GERMAN Postal Code on sticker:

      Sticker on Case:
        "GAME BOY advance, WIRELESS ADAPTER"
        "Pat.Pend.Made in Philipines, CE0125(!)B"
        "MODEL NO./MODELE NO.AGB-015 D-63760 Grossosteim P/AGB-A-WA-EUR-2 E3"
      PCB: "19-C046-04, A-7" (top side) and "B-7" and Microchip ",\\" (bottom side)
      PCB: white stamp "3104, 94V-0, RU, TW-15"
      PCB: black stamp "22FDE"
      U1 32pin "Freescale 13190, 4WFQ" (MC13190) (2.4 GHz ISM band transceiver)
      U2 48pin "Freescale CT3001, XAC0445"  (bottom side)
      X3  2pin "D959L4I" (9.5MHz)           (top side) (ca. 19 clks per 2us)

Further components... top side (A-7)

      D1   5pin "D6F, 44"   (top side, below X3)
      U71  6pin ".., () 2"  (top side, right of X3, tiny black chip)
      B71  6pin "[]"        (top side, right of X3, small white chip)
      ANT  2pin on-board copper wings
      Q?   3pin             (top side, above CN1)
      Q?   3pin             (top side, above CN1)
      D?   2pin "72"        (top side, above CN1)
      D3   2pin "F2"        (top side, above CN1)
      U200 4pin "MSV"       (top side, above CN1)
      U202 5pin "LXKA"      (top side, right of CN1)
      U203 4pin "M6H"       (top side, right of CN1)
      CN1  6pin connector to GBA link port (top side)

Further components... bottom side (B-7)

      U201 5pin "LXVB"      (bottom side, near CN1)
      U72  4pin "BMs"       (bottom side, near ANT, tiny black chip)
      FL70 ?pin "[] o26"    (bottom side, near ANT, bigger white chip)
      B70  6pin "[]"        (bottom side, near ANT, small white chip)

Plus, resistors and capacitors (without any markings).
Version WITHOUT sticker:

      Sticker on Case: N/A
      PCB: "19-C046-03, A-1" (top side) and "B-1" and Microchip ",\\" (bottom side)
      PCB: white stamp "3204, TW-15, RU, 94V-0"
      PCB: black stamp "23MN" or "23NH" or so (smeared)
      U1 32pin "Freescale 13190, 4FGD"      (top side)
      U2 48pin "Freescale CT3000, XAB0425"  (bottom side) ;CT3000 (not CT3001)
      X3  2pin "9.5SKSS4GT"                 (top side)

Further components... top side (A-1)

      D1   5pin "D6F, 31"   (top side, below X3)
      U71  6pin "P3, () 2"  (top side, right of X3, tiny black chip)
      B71  6pin "[]"        (top side, right of X3, small white chip)
      ANT  2pin on-board copper wings
      Q70  3pin             (top side, above CN1)
      D?   2pin "72"        (top side, above CN1)
      D3   2pin "F2"        (top side, above CN1)
      U200 4pin "MSV"       (top side, above CN1)
      U202 5pin "LXKH"      (top side, right of CN1)
      U203 4pin "M6H"       (top side, right of CN1)
      CN1  6pin connector to GBA link port (top side)

Further components... bottom side (B-1)

      U201 5pin "LXV2"      (bottom side, near CN1)
      U70  6pin "AAG"       (bottom side, near ANT, tiny black chip)
      FL70 ?pin "[] o26"    (bottom side, near ANT, bigger white chip)
      B70  6pin "[]"        (bottom side, near ANT, small white chip)

Plus, resistors and capacitors (without any markings).
Major Differences

      Sticker      "N/A"                     vs "Grossosteim P/AGB-A-WA-EUR-2 E3"
      PCB-markings "19-C046-03, A-1, 3204"   vs "19-C046-04, A-7, 3104"
      U1           "CT3000, XAB0425"         vs "CT3001, XAC0445"
      Transistors  One transistor (Q70)      vs Two transistors (both nameless)
      U70/U72      U70 "AAG" (6pin)          vs U72 "BMs" (4pin)

Purpose of the changes is unknown (either older/newer revisions, or different regions with different FCC regulations).

GBA Infrared Communication

Early GBA prototypes have been intended to include a built-in IR port for sending and receiving IR signals. Among others, this port could have been used to communicate with other GBAs, or older CGB models, or TV Remote Controls, etc.
[ THE INFRARED COMMUNICATION FEATURE IS -NOT- SUPPORTED ANYMORE ]
Anyways, the prototype specifications have been as shown below...
Keep in mind that the IR signal may be interrupted by whatever objects moved between sender and receiver - the IR port isn't recommended for programs that require realtime data exchange (such like action games).
4000136h - IR - Infrared Register (R/W)

      Bit   Expl.
      0     Transmission Data  (0=LED Off, 1=LED On)
      1     READ Enable        (0=Disable, 1=Enable)
      2     Reception Data     (0=None, 1=Signal received) (Read only)
      3     AMP Operation      (0=Off, 1=On)
      4     IRQ Enable Flag    (0=Disable, 1=Enable)
      5-15  Not used

When IRQ is enabled, an interrupt is requested if the incoming signal was 0.119us Off (2 cycles), followed by 0.536us On (9 cycles) - minimum timing periods each.
Transmission Notes
When transmitting an IR signal, note that it'd be not a good idea to keep the LED turned On for a very long period (such like sending a 1 second synchronization pulse). The recipient's circuit would treat such a long signal as "normal IR pollution which is in the air" after a while, and thus ignore the signal.
Reception Notes
Received data is internally latched. Latched data may be read out by setting both READ and AMP bits.
Note: Provided that you don't want to receive your own IR signal, be sure to set Bit 0 to zero before attempting to receive data.
Power-consumption
After using the IR port, be sure to reset the register to zero in order to reduce battery power consumption.

GBA Keypad Input

The built-in GBA gamepad has 4 direction keys, and 6 buttons.
4000130h - KEYINPUT - Key Status (R)

      Bit   Expl.
      0     Button A        (0=Pressed, 1=Released)
      1     Button B        (etc.)
      2     Select          (etc.)
      3     Start           (etc.)
      4     Right           (etc.)
      5     Left            (etc.)
      6     Up              (etc.)
      7     Down            (etc.)
      8     Button R        (etc.)
      9     Button L        (etc.)
      10-15 Not used

It'd be usually recommended to read-out this register only once per frame, and to store the current state in memory. As a side effect, this method avoids problems caused by switch bounce when a key is newly released or pressed.
4000132h - KEYCNT - Key Interrupt Control (R/W)
The keypad IRQ function is intended to terminate the very-low-power Stop mode, it is not suitable for processing normal user input, to do this, most programs are invoking their keypad handlers from within VBlank IRQ.

      Bit   Expl.
      0     Button A        (0=Ignore, 1=Select)
      1     Button B        (etc.)
      2     Select          (etc.)
      3     Start           (etc.)
      4     Right           (etc.)
      5     Left            (etc.)
      6     Up              (etc.)
      7     Down            (etc.)
      8     Button R        (etc.)
      9     Button L        (etc.)
      10-13 Not used
      14    IRQ Enable Flag (0=Disable, 1=Enable)
      15    IRQ Condition   (0=Logical OR, 1=Logical AND)

In logical OR mode, an interrupt is requested when at least one of the selected buttons is pressed.
In logical AND mode, an interrupt is requested when ALL of the selected buttons are pressed.
Notes
In 8bit gameboy compatibility mode, L and R Buttons are used to toggle the screen size between normal 160x144 pixels and stretched 240x144 pixels.
The GBA SP is additionally having a * Button used to toggle the backlight on and off (controlled by separate hardware logic, there's no way to detect or change the current backlight state by software).

GBA Interrupt Control

4000208h - IME - Interrupt Master Enable Register (R/W)

      Bit   Expl.
      0     Disable all interrupts         (0=Disable All, 1=See IE register)
      1-31  Not used

4000200h - IE - Interrupt Enable Register (R/W)

      Bit   Expl.
      0     LCD V-Blank                    (0=Disable)
      1     LCD H-Blank                    (etc.)
      2     LCD V-Counter Match            (etc.)
      3     Timer 0 Overflow               (etc.)
      4     Timer 1 Overflow               (etc.)
      5     Timer 2 Overflow               (etc.)
      6     Timer 3 Overflow               (etc.)
      7     Serial Communication           (etc.)
      8     DMA 0                          (etc.)
      9     DMA 1                          (etc.)
      10    DMA 2                          (etc.)
      11    DMA 3                          (etc.)
      12    Keypad                         (etc.)
      13    Game Pak (external IRQ source) (etc.)
      14-15 Not used

Note that there is another 'master enable flag' directly in the CPUs Status Register (CPSR) accessible in privileged modes, see CPU reference for details.
4000202h - IF - Interrupt Request Flags / IRQ Acknowledge (R/W, see below)

      Bit   Expl.
      0     LCD V-Blank                    (1=Request Interrupt)
      1     LCD H-Blank                    (etc.)
      2     LCD V-Counter Match            (etc.)
      3     Timer 0 Overflow               (etc.)
      4     Timer 1 Overflow               (etc.)
      5     Timer 2 Overflow               (etc.)
      6     Timer 3 Overflow               (etc.)
      7     Serial Communication           (etc.)
      8     DMA 0                          (etc.)
      9     DMA 1                          (etc.)
      10    DMA 2                          (etc.)
      11    DMA 3                          (etc.)
      12    Keypad                         (etc.)
      13    Game Pak (external IRQ source) (etc.)
      14-15 Not used

Interrupts must be manually acknowledged by writing a "1" to one of the IRQ bits, the IRQ bit will then be cleared.
"[Cautions regarding clearing IME and IE]
A corresponding interrupt could occur even while a command to clear IME or each flag of the IE register is being executed. When clearing a flag of IE, you need to clear IME in advance so that mismatching of interrupt checks will not occur." ?
"[When multiple interrupts are used]
When the timing of clearing of IME and the timing of an interrupt agree, multiple interrupts will not occur during that interrupt. Therefore, set (enable) IME after saving IME during the interrupt routine." ?
BIOS Interrupt handling
Upon interrupt execution, the CPU is switched into IRQ mode, and the physical interrupt vector is called - as this address is located in BIOS ROM, the BIOS will always execute the following code before it forwards control to the user handler:

      00000018  b      128h                ;IRQ vector: jump to actual BIOS handler
      00000128  stmfd  r13!,r0-r3,r12,r14  ;save registers to SP_irq
      0000012C  mov    r0,4000000h         ;ptr+4 to 03FFFFFC (mirror of 03007FFC)
      00000130  add    r14,r15,0h          ;retadr for USER handler $+8=138h
      00000134  ldr    r15,[r0,-4h]        ;jump to [03FFFFFC] USER handler
      00000138  ldmfd  r13!,r0-r3,r12,r14  ;restore registers from SP_irq
      0000013C  subs   r15,r14,4h          ;return from IRQ (PC=LR-4, CPSR=SPSR)

As shown above, a pointer to the 32bit/ARM-code user handler must be setup in [03007FFCh]. By default, 160 bytes of memory are reserved for interrupt stack at 03007F00h-03007F9Fh.
Recommended User Interrupt handling
- If necessary switch to THUMB state manually (handler is called in ARM state)
- Determine reason(s) of interrupt by examining IF register
- User program may freely assign priority to each reason by own logic
- Process the most important reason of your choice
- User MUST manually acknowledge by writing to IF register
- If user wants to allow nested interrupts, save SPSR_irq, then enable IRQs.
- If using other registers than BIOS-pushed R0-R3, manually save R4-R11 also.
- Note that Interrupt Stack is used (which may have limited size)
- So, for memory consuming stack operations use system mode (=user stack).
- When calling subroutines in system mode, save LSR_usr also.
- Restore SPSR_irq and/or R4-R11 if you've saved them above.
- Finally, return to BIOS handler by BX LR (R14_irq) instruction.
Default memory usage at 03007FXX (and mirrored to 03FFFFXX)

      Addr.    Size Expl.
      3007FFCh 4    Pointer to user IRQ handler (32bit ARM code)
      3007FF8h 2    Interrupt Check Flag (for IntrWait/VBlankIntrWait functions)
      3007FF4h 4    Allocated Area
      3007FF0h 4    Pointer to Sound Buffer
      3007FE0h 16   Allocated Area
      3007FA0h 64   Default area for SP_svc Supervisor Stack (4 words/time)
      3007F00h 160  Default area for SP_irq Interrupt Stack (6 words/time)

Memory below 7F00h is free for User Stack and user data. The three stack pointers are initially initialized at the TOP of the respective areas:

      SP_svc=03007FE0h
      SP_irq=03007FA0h
      SP_usr=03007F00h

The user may redefine these addresses and move stacks into other locations, however, the addresses for system data at 7FE0h-7FFFh are fixed.
Not sure, is following free for user ?
Registers R8-R12_fiq, R13_fiq, R14_fiq, SPSR_fiq
Registers R13-R14_abt, SPSR_abt
Registers R13-R14_und, SPSR_und
Fast Interrupt (FIQ)
The ARM CPU provides two interrupt sources, IRQ and FIQ. In the GBA only IRQ is used. In normal GBAs, the FIQ signal is shortcut to VDD35, ie. the signal is always high, and there is no way to generate a FIQ by hardware. The registers R8..12_fiq could be used by software (when switching into FIQ mode by writing to CPSR) - however, this might make the game incompatible with hardware debuggers (which are reportedly using FIQs for debugging purposes).

GBA System Control

4000204h - WAITCNT - Waitstate Control (R/W)
This register is used to configure game pak access timings. The game pak ROM is mirrored to three address regions at 08000000h, 0A000000h, and 0C000000h, these areas are called Wait State 0-2. Different access timings may be assigned to each area (this might be useful in case that a game pak contains several ROM chips with different access times each).

      Bit   Expl.
      0-1   SRAM Wait Control          (0..3 = 4,3,2,8 cycles)
      2-3   Wait State 0 First Access  (0..3 = 4,3,2,8 cycles)
      4     Wait State 0 Second Access (0..1 = 2,1 cycles)
      5-6   Wait State 1 First Access  (0..3 = 4,3,2,8 cycles)
      7     Wait State 1 Second Access (0..1 = 4,1 cycles; unlike above WS0)
      8-9   Wait State 2 First Access  (0..3 = 4,3,2,8 cycles)
      10    Wait State 2 Second Access (0..1 = 8,1 cycles; unlike above WS0,WS1)
      11-12 PHI Terminal Output        (0..3 = Disable, 4.19MHz, 8.38MHz, 16.78MHz)
      13    Not used
      14    Game Pak Prefetch Buffer (Pipe) (0=Disable, 1=Enable)
      15    Game Pak Type Flag  (Read Only) (0=GBA, 1=CGB) (IN35 signal)
      16-31 Not used

At startup, the default setting is 0000h. Currently manufactured cartridges are using the following settings: WS0/ROM=3,1 clks; SRAM=8 clks; WS2/EEPROM: 8,8 clks; prefetch enabled; that is, WAITCNT=4317h, for more info see "GBA Cartridges" chapter.
First Access (Non-sequential) and Second Access (Sequential) define the waitstates for N and S cycles, the actual access time is 1 clock cycle PLUS the number of waitstates.
GamePak uses 16bit data bus, so that a 32bit access is split into TWO 16bit accesses (of which, the second fragment is always sequential, even if the first fragment was non-sequential).
GBA GamePak Prefetch
NOTES:
The GBA forcefully uses non-sequential timing at the beginning of each 128K-block of gamepak ROM, eg. "LDMIA [801fff8h],r0-r7" will have non-sequential timing at 8020000h.
The PHI Terminal output (PHI Pin of Gamepak Bus) should be disabled.
4000300h - POSTFLG - BYTE - Undocumented - Post Boot / Debug Control (R/W)
After initial reset, the GBA BIOS initializes the register to 01h, and any further execution of the Reset vector (00000000h) will pass control to the Debug vector (0000001Ch) when sensing the register to be still set to 01h.

      Bit   Expl.
      0     Undocumented. First Boot Flag  (0=First, 1=Further)
      1-7   Undocumented. Not used.

Normally the debug handler rejects control unless it detects Debug flags in cartridge header, in that case it may redirect to a cut-down boot procedure (bypassing Nintendo logo and boot delays, much like nocash burst boot for multiboot software). I am not sure if it is possible to reset the GBA externally without automatically resetting register 300h though.
4000301h - HALTCNT - BYTE - Undocumented - Low Power Mode Control (W)
Writing to this register switches the GBA into battery saving mode.
In Halt mode, the CPU is paused as long as (IE AND IF)=0, this should be used to reduce power-consumption during periods when the CPU is waiting for interrupt events.
In Stop mode, most of the hardware including sound and video are paused, this very-low-power mode could be used much like a screensaver.

      Bit   Expl.
      0-6   Undocumented. Not used.
      7     Undocumented. Power Down Mode  (0=Halt, 1=Stop)

The current GBA BIOS addresses only the upper eight bits of this register (by writing 00h or 80h to address 04000301h), however, as the register isn't officially documented, some or all of the bits might have different meanings in future GBA models.
For best forwards compatibility, it'd generally be more recommended to use the BIOS Functions SWI 2 (Halt) or SWI 3 (Stop) rather than writing to this register directly.
4000410h - Undocumented - Purpose Unknown ? 8bit (W)
The BIOS writes the 8bit value 0FFh to this address. Purpose Unknown.
Probably just another bug in the BIOS.
4000800h - 32bit - Undocumented - Internal Memory Control (R/W)
Supported by GBA and GBA SP only - NOT supported by DS (even in GBA mode).
Also supported by GBA Micro - but crashes on "overclocked" WRAM setting.
Initialized to 0D000020h (by hardware). Unlike all other I/O registers, this register is mirrored across the whole I/O area (in increments of 64K, ie. at 4000800h, 4010800h, 4020800h, ..., 4FF0800h)

      Bit   Expl.
      0     Disable 32K+256K WRAM (0=Normal, 1=Disable) (when off: empty/prefetch)
      1-3   Unknown          (Read/Write-able)
      4     Unknown          (Always zero, not used or write only)
      5     Enable 256K WRAM (0=Disable, 1=Normal) (when off: mirror of 32K WRAM)
      6-23  Unknown          (Always zero, not used or write only)
      24-27 Wait Control WRAM 256K (0-14 = 15..1 Waitstates, 15=Lockup)
      28-31 Unknown          (Read/Write-able)

The default value 0Dh in Bits 24-27 selects 2 waitstates for 256K WRAM (ie. 3/3/6 cycles 8/16/32bit accesses). The fastest possible setting would be 0Eh (1 waitstate, 2/2/4 cycles for 8/16/32bit), that works on GBA and GBA SP only, the GBA Micro locks up with that setting (it's on-chip RAM is too slow, and works only with 2 or more waitstates).
Note: One cycle equals approx. 59.59ns (ie. 16.78MHz clock).

GBA GamePak Prefetch

GamePak Prefetch can be enabled in WAITCNT register. When prefetch buffer is enabled, the GBA attempts to read opcodes from Game Pak ROM during periods when the CPU is not using the bus (if any). Memory access is then performed with 0 Waits if the CPU requests data which is already stored in the buffer. The prefetch buffer stores up to eight 16bit values.
GamePak ROM Opcodes
The prefetch feature works only with <opcodes> fetched from GamePak ROM. Opcodes executed in RAM or BIOS are not affected by the prefetch feature (even if that opcodes read <data> from GamePak ROM).
Prefetch Enable
For GamePak ROM opcodes, prefetch may occur in two situations:

      1) opcodes with internal cycles (I) which do not change R15, shift/rotate
         register-by-register, load opcodes (ldr,ldm,pop,swp), multiply opcodes
      2) opcodes that load/store memory (ldr,str,ldm,stm,etc.)

Prefetch Disable Bug
When Prefetch is disabled, the Prefetch Disable Bug will occur for all

      "Opcodes in GamePak ROM with Internal Cycles which do not change R15"

for those opcodes, the bug changes the opcode fetch time from 1S to 1N.
Note: Affected opcodes (with I cycles) are: Shift/rotate register-by-register opcodes, multiply opcodes, and load opcodes (ldr,ldm,pop,swp).

GBA Cartridges

ROM
GBA Cartridge Header
GBA Cartridge ROM
Backup Media
Aside from ROM, cartridges may also include one of the following backup medias, used to store game positions, highscore tables, options, or other data.
GBA Cart Backup IDs
GBA Cart Backup SRAM/FRAM
GBA Cart Backup EEPROM
GBA Cart Backup Flash ROM
GBA Cart Backup DACS
Add-Ons
GBA Cart I/O Port (GPIO)
GBA Cart Real-Time Clock (RTC)
GBA Cart Solar Sensor
GBA Cart Tilt Sensor
GBA Cart Gyro Sensor
GBA Cart Rumble
GBA Cart e-Reader
GBA Cart Unknown Devices
GBA Cart Protections
Other Accessoires
GBA Flashcards
GBA Cheat Devices

GBA Cartridge Header

The first 192 bytes at 8000000h-80000BFh in ROM are used as cartridge header. The same header is also used for Multiboot images at 2000000h-20000BFh (plus some additional multiboot entries at 20000C0h and up).
Header Overview

      Address Bytes Expl.
      000h    4     ROM Entry Point  (32bit ARM branch opcode, eg. "B rom_start")
      004h    156   Nintendo Logo    (compressed bitmap, required!)
      0A0h    12    Game Title       (uppercase ascii, max 12 characters)
      0ACh    4     Game Code        (uppercase ascii, 4 characters)
      0B0h    2     Maker Code       (uppercase ascii, 2 characters)
      0B2h    1     Fixed value      (must be 96h, required!)
      0B3h    1     Main unit code   (00h for current GBA models)
      0B4h    1     Device type      (usually 00h) (bit7=DACS/debug related)
      0B5h    7     Reserved Area    (should be zero filled)
      0BCh    1     Software version (usually 00h)
      0BDh    1     Complement check (header checksum, required!)
      0BEh    2     Reserved Area    (should be zero filled)
      --- Additional Multiboot Header Entries ---
      0C0h    4     RAM Entry Point  (32bit ARM branch opcode, eg. "B ram_start")
      0C4h    1     Boot mode        (init as 00h - BIOS overwrites this value!)
      0C5h    1     Slave ID Number  (init as 00h - BIOS overwrites this value!)
      0C6h    26    Not used         (seems to be unused)
      0E0h    4     JOYBUS Entry Pt. (32bit ARM branch opcode, eg. "B joy_start")

Note: With all entry points, the CPU is initially set into system mode.
000h - Entry Point, 4 Bytes
Space for a single 32bit ARM opcode that redirects to the actual startaddress of the cartridge, this should be usually a "B <start>" instruction.
Note: This entry is ignored by Multiboot slave GBAs (in fact, the entry is then overwritten and redirected to a separate Multiboot Entry Point, as described below).
004h..09Fh - Nintendo Logo, 156 Bytes
Contains the Nintendo logo which is displayed during the boot procedure. Cartridge won't work if this data is missing or modified.
In detail: This area contains Huffman compression data (but excluding the compression header which is hardcoded in the BIOS, so that it'd be probably not possible to hack the GBA by producing de-compression buffer overflows).
A copy of the compression data is stored in the BIOS, the GBA will compare this data and lock-up itself if the BIOS data isn't exactly the same as in the cartridge (or multiboot header). The only exception are the two entries below which are allowed to have variable settings in some bits.
09Ch Bit 2,7 - Debugging Enable
This is part of the above Nintendo Logo area, and must be commonly set to 21h, however, Bit 2 and Bit 7 may be set to other values.
When both bits are set (ie. A5h), the FIQ/Undefined Instruction handler in the BIOS becomes unlocked, the handler then forwards these exceptions to the user handler in cartridge ROM (entry point defined in 80000B4h, see below).
Other bit combinations currently do not seem to have special functions.
09Eh Bit 0,1 - Cartridge Key Number MSBs
This is part of the above Nintendo Logo area, and must be commonly set to F8h, however, Bit 0-1 may be set to other values.
During startup, the BIOS performs some dummy-reads from a stream of pre-defined addresses, even though these reads seem to be meaningless, they might be intended to unlock a read-protection inside of commercial cartridge. There are 16 pre-defined address streams - selected by a 4bit key number - of which the upper two bits are gained from 800009Eh Bit 0-1, and the lower two bits from a checksum across header bytes 09Dh..0B7h (bytewise XORed, divided by 40h).
0A0h - Game Title, Uppercase Ascii, max 12 characters
Space for the game title, padded with 00h (if less than 12 chars).
0ACh - Game Code, Uppercase Ascii, 4 characters
This is the same code as the AGB-UTTD code which is printed on the package and sticker on (commercial) cartridges (excluding the leading "AGB-" part).

      U  Unique Code          (usually "A" or "B" or special meaning)
      TT Short Title          (eg. "PM" for Pac Man)
      D  Destination/Language (usually "J" or "E" or "P" or specific language)

The first character (U) is usually "A" or "B", in detail:

      A  Normal game; Older titles (mainly 2001..2003)
      B  Normal game; Newer titles (2003..)
      C  Normal game; Not used yet, but might be used for even newer titles
      F  Famicom/Classic NES Series (software emulated NES games)
      K  Yoshi and Koro Koro Puzzle (acceleration sensor)
      P  e-Reader (dot-code scanner)
      R  Warioware Twisted (cartridge with rumble and z-axis gyro sensor)
      U  Boktai 1 and 2 (cartridge with RTC and solar sensor)
      V  Drill Dozer (cartridge with rumble)

The second/third characters (TT) are:

      Usually an abbreviation of the game title (eg. "PM" for "Pac Man") (unless
      that gamecode was already used for another game, then TT is just random)

The fourth character (D) indicates Destination/Language:

      J  Japan             P  Europe/Elsewhere   F  French          S  Spanish
      E  USA/English       D  German             I  Italian

0B0h - Maker code, Uppercase Ascii, 2 characters
Identifies the (commercial) developer. For example, "01"=Nintendo.
0B2h - Fixed value, 1 Byte
Must be 96h.
0B3h - Main unit code, 1 Byte
Identifies the required hardware. Should be 00h for current GBA models.
0B4h - Device type, 1 Byte
Normally, this entry should be zero. With Nintendo's hardware debugger Bit 7 identifies the debugging handlers entry point and size of DACS (Debugging And Communication System) memory: Bit7=0: 9FFC000h/8MBIT DACS, Bit7=1: 9FE2000h/1MBIT DACS. The debugging handler can be enabled in 800009Ch (see above), normal cartridges do not have any memory (nor any mirrors) at these addresses though.
0B5h - Reserved Area, 7 Bytes
Reserved, zero filled.
0BCh - Software version number
Version number of the game. Usually zero.
0BDh - Complement check, 1 Byte
Header checksum, cartridge won't work if incorrect. Calculate as such:
chk=0:for i=0A0h to 0BCh:chk=chk-[i]:next:chk=(chk-19h) and 0FFh
0BEh - Reserved Area, 2 Bytes
Reserved, zero filled.
Below required for Multiboot/slave programs only. For Multiboot, the above 192 bytes are required to be transferred as header-block (loaded to 2000000h-20000BFh), and some additional header-information must be located at the beginning of the actual program/data-block (loaded to 20000C0h and up). This extended header consists of Multiboot Entry point(s) which must be set up correctly, and of two reserved bytes which are overwritten by the boot procedure:
0C0h - Normal/Multiplay mode Entry Point
This entry is used only if the GBA has been booted by using Normal or Multiplay transfer mode (but not by Joybus mode).
Typically deposit a ARM-32bit "B <start>" branch opcode at this location, which is pointing to your actual initialization procedure.
0C4h (BYTE) - Boot mode
The slave GBA download procedure overwrites this byte by a value which is indicating the used multiboot transfer mode.

      Value  Expl.
      01h    Joybus mode
      02h    Normal mode
      03h    Multiplay mode

Typically set this byte to zero by inserting DCB 00h in your source.
Be sure that your uploaded program does not contain important program code or data at this location, or at the ID-byte location below.
0C5h (BYTE) - Slave ID Number
If the GBA has been booted in Normal or Multiplay mode, this byte becomes overwritten by the slave ID number of the local GBA (that'd be always 01h for normal mode).

      Value  Expl.
      01h    Slave #1
      02h    Slave #2
      03h    Slave #3

Typically set this byte to zero by inserting DCB 00h in your source.
When booted in Joybus mode, the value is NOT changed and remains the same as uploaded from the master GBA.
0C6h..0DFh - Not used
Appears to be unused.
0E0h - Joybus mode Entry Point
If the GBA has been booted by using Joybus transfer mode, then the entry point is located at this address rather than at 20000C0h. Either put your initialization procedure directly at this address, or redirect to the actual boot procedure by depositing a "B <start>" opcode here (either one using 32bit ARM code). Or, if you are not intending to support joybus mode (which is probably rarely used), ignore this entry.

GBA Cartridge ROM

ROM Size
The games F-ZERO and Super Mario Advance use ROMs of 4 MBytes each. Zelda uses 8 MBytes. Not sure if other sizes are manufactured.
ROM Waitstates
The GBA starts the cartridge with 4,2 waitstates (N,S) and prefetch disabled. The program may change these settings by writing to WAITCNT, the games F-ZERO and Super Mario Advance use 3,1 waitstates (N,S) each, with prefetch enabled.
Third-party flashcards are reportedly running unstable with these settings. Also, prefetch and shorter waitstates are allowing to read more data and opcodes from ROM is less time, the downside is that it increases the power consumption.
ROM Chip
Because of how 24bit addresses are squeezed through the Gampak bus, the cartridge must include a circuit that latches the lower 16 address bits on non-sequential access, and that increments these bits on sequential access. Nintendo includes this circuit directly in the ROM chip.
Also, the ROM must have 16bit data bus (or a circuit which converts two 8bit data units into one 16bit unit - by not exceeding the waitstate timings).

GBA Cart Backup IDs

Nintendo didn't include a backup-type entry in the ROM header, however, the required type can be detected by ID strings in the ROM-image. Nintendo's tools are automatically inserting these strings (as part of their library headers). When using other tools, you may insert ID strings by hand.
ID Strings
The ID string must be located at a word-aligned memory location, the string length should be a multiple of 4 bytes (padded with zero's).

      EEPROM_Vnnn    EEPROM 512 bytes or 8 Kbytes (4Kbit or 64Kbit)
      SRAM_Vnnn      SRAM 32 Kbytes (256Kbit)
      FLASH_Vnnn     FLASH 64 Kbytes (512Kbit) (ID used in older files)
      FLASH512_Vnnn  FLASH 64 Kbytes (512Kbit) (ID used in newer files)
      FLASH1M_Vnnn   FLASH 128 Kbytes (1Mbit)

For Nintendo's tools, "nnn" is a 3-digit library version number. When using other tools, best keep it set to "nnn" rather than inserting numeric digits.
Notes
No$gba does auto-detect most backup types, even without ID strings, except for 128K FLASH (without ID "FLASH1M_Vnnn", the FLASH size defaults to 64K). Ideally, for faster detection, the ID should be put into the first some bytes of the ROM-image (ie. somewhere right after the ROM header).

GBA Cart Backup SRAM/FRAM

SRAM - 32 KBytes (256Kbit) Lifetime: Depends on back-up battery
FRAM - 32 KBytes (256Kbit) Lifetime: 10,000,000,000 read/write per bit
Hyundai GM76V256CLLFW10 SRAM (Static RAM) (eg. F-Zero)
Fujitsu MB85R256 FRAM (Ferroelectric RAM) (eg. Warioware Twisted)
Addressing and Waitstates
SRAM/FRAM is mapped to E000000h-E007FFFh, it should be accessed with 8 waitstates (write a value of 3 into Bit0-1 of WAITCNT).
Databus Width
The SRAM/FRAM databus is restricted to 8 bits, it should be accessed by LDRB, LDRSB, and STRB opcodes only.
Reading and Writing
Reading from SRAM/FRAM should be performed by code executed in WRAM only (but not by code executed in ROM). There is no such restriction for writing.
Preventing Data Loss
The GBA SRAM/FRAM carts do not include a write-protect function (unlike older 8bit gameboy carts). This seems to be a problem and may cause data loss when a cartridge is removed or inserted while the GBA is still turned on. As far as I understand, this is not so much a hardware problem, but rather a software problem, ie. theoretically you could remove/insert the cartridge as many times as you want, but you should take care that your program does not crash (and write blindly into memory).
Recommended Workaround
Enable the Gamepak Interrupt (it'll most likely get triggered when removing the cartridge), and hang-up the GBA in an endless loop when your interrupt handler senses a Gamepak IRQ. For obvious reason, your interrupt handler should be located in WRAM, ie. not in the (removed) ROM cartridge. The handler should process Gamepak IRQs at highest priority. Periods during which interrupts are disabled should be kept as short as possible, if necessary allow nested interrupts.
When to use the above Workaround
A program that relies wholly on code and data in WRAM, and that does not crash even when ROM is removed, may keep operating without having to use the above mechanism.
Do NOT use the workaround for programs that run without a cartridge inserted (ie. single gamepak/multiboot slaves), or for programs that use Gamepak IRQ/DMA for other purposes.
All other programs should use it. It'd be eventually a good idea to include it even in programs that do not use SRAM/FRAM themselves (eg. otherwise removing a SRAM/FRAM-less cartridge may lock up the GBA, and may cause it to destroy backup data when inserting a SRAM/FRAM cartridge).
SRAM vs FRAM
FRAM (Ferroelectric RAM) is a newer technology, used in newer GBA carts, unlike SRAM (Static RAM), it doesn't require a battery to hold the data. At software side, it is accessed exactly like SRAM, ie. unlike EEPROM/FLASH, it doesn't require any Write/Erase commands/delays.
Note
In SRAM/FRAM cartridges, the /REQ pin (Pin 31 of Gamepak bus) should be a little bit shorter as than the other pins; when removing the cartridge, this causes the gamepak IRQ signal to get triggered before the other pins are disconnected.

GBA Cart Backup EEPROM

9853 - EEPROM 512 Bytes (0200h) (4Kbit) (eg. used by Super Mario Advance)
9854 - EEPROM 8 KBytes (2000h) (64Kbit) (eg. used by Boktai)
Lifetime: 100,000 writes per address
Addressing and Waitstates
The eeprom is connected to Bit0 of the data bus, and to the upper 1 bit (or upper 17 bits in case of large 32MB ROM) of the cartridge ROM address bus, communication with the chip takes place serially.
The eeprom must be used with 8 waitstates (set WAITCNT=X3XXh; 8,8 clks in WS2 area), the eeprom can be then addressed at DFFFF00h..DFFFFFFh.
Respectively, with eeprom, ROM is restricted to 8000000h-9FFFeFFh (max. 1FFFF00h bytes = 32MB minus 256 bytes). On carts with 16MB or smaller ROM, eeprom can be alternately accessed anywhere at D000000h-DFFFFFFh.
Data and Address Width
Data can be read from (or written to) the EEPROM in units of 64bits (8 bytes). Writing automatically erases the old 64bits of data. Addressing works in units of 64bits respectively, that is, for 512 Bytes EEPROMS: an address range of 0-3Fh, 6bit bus width; and for 8KByte EEPROMs: a range of 0-3FFh, 14bit bus width (only the lower 10 address bits are used, upper 4 bits should be zero).
Set Address (For Reading)
Prepare the following bitstream in memory:

      2 bits "11" (Read Request)
      n bits eeprom address (MSB first, 6 or 14 bits, depending on EEPROM)
      1 bit "0"

Then transfer the stream to eeprom by using DMA.
Read Data
Read a stream of 68 bits from EEPROM by using DMA,
then decipher the received data as follows:

      4 bits - ignore these
     64 bits - data (conventionally MSB first)

Write Data to Address
Prepare the following bitstream in memory, then transfer the stream to eeprom by using DMA, it'll take ca. 108368 clock cycles (ca. 6.5ms) until the old data is erased and new data is programmed.

      2 bits "10" (Write Request)
      n bits eeprom address (MSB first, 6 or 14 bits, depending on EEPROM)
     64 bits data (conventionally MSB first)
      1 bit "0"

After the DMA, keep reading from the chip, by normal LDRH [DFFFF00h], until Bit 0 of the returned data becomes "1" (Ready). To prevent your program from locking up in case of malfunction, generate a timeout if the chip does not reply after 10ms or longer.
Using DMA
Transferring a bitstreams to/from the EEPROM must be done via DMA3 (manual transfers via LDRH/STRH won't work; probably because they don't keep /CS=LOW and A23=HIGH throughout the transfer).
For using DMA, a buffer in memory must be used (that buffer would be typically allocated temporarily on stack, one halfword for each bit, bit1-15 of the halfwords are don't care, only bit0 is used).
The buffer must be transfered as a whole to/from EEPROM by using DMA3 (DMA0-2 can't access external memory), use 16bit transfer mode, both source and destination address incrementing (ie. DMA3CNT=80000000h+length).
DMA channels of higher priority should be disabled during the transfer (ie. H/V-Blank or Sound FIFO DMAs). And, of course any interrupts that might mess with DMA registers should be disabled.
Pin-Outs
The EEPROM chips are having only 8 pins, these are connected, Pin 1..8, to ROMCS, RD, WR, AD0, GND, GND, A23, VDD of the GamePak bus. Carts with 32MB ROM must have A7..A22 logically ANDed with A23.
Notes
There seems to be no autodection mechanism, so that a hardcoded bus width must be used.

GBA Cart Backup Flash ROM

64 KBytes - 512Kbits Flash ROM - Lifetime: 10,000 writes per sector
128 KBytes - 1Mbit Flash ROM - Lifetime: ??? writes per sector
Chip Identification (all device types)

      [E005555h]=AAh, [E002AAAh]=55h, [E005555h]=90h  (enter ID mode)
      dev=[E000001h], man=[E000000h]                  (get device & manufacturer)
      [E005555h]=AAh, [E002AAAh]=55h, [E005555h]=F0h  (terminate ID mode)

Used to detect the type (and presence) of FLASH chips. See Device Types below.
Reading Data Bytes (all device types)

      dat=[E00xxxxh]                                  (read byte from address xxxx)

Erase Entire Chip (all device types)

      [E005555h]=AAh, [E002AAAh]=55h, [E005555h]=80h  (erase command)
      [E005555h]=AAh, [E002AAAh]=55h, [E005555h]=10h  (erase entire chip)
      wait until [E000000h]=FFh (or timeout)

Erases all memory in chip, erased memory is FFh-filled.
Erase 4Kbyte Sector (all device types, except Atmel)

      [E005555h]=AAh, [E002AAAh]=55h, [E005555h]=80h  (erase command)
      [E005555h]=AAh, [E002AAAh]=55h, [E00n000h]=30h  (erase sector n)
      wait until [E00n000h]=FFh (or timeout)

Erases memory at E00n000h..E00nFFFh, erased memory is FFh-filled.
Erase-and-Write 128 Bytes Sector (only Atmel devices)

      old=IME, IME=0                                  (disable interrupts)
      [E005555h]=AAh, [E002AAAh]=55h, [E005555h]=A0h  (erase/write sector command)
      [E00xxxxh+00h..7Fh]=dat[00h..7Fh]               (write 128 bytes)
      IME=old                                         (restore old IME state)
      wait until [E00xxxxh+7Fh]=dat[7Fh] (or timeout)

Interrupts (and DMAs) should be disabled during command/write phase. Target address must be a multiple of 80h.
Write Single Data Byte (all device types, except Atmel)

      [E005555h]=AAh, [E002AAAh]=55h, [E005555h]=A0h  (write byte command)
      [E00xxxxh]=dat                                  (write byte to address xxxx)
      wait until [E00xxxxh]=dat (or timeout)

The target memory location must have been previously erased.
Terminate Command after Timeout (only Macronix devices, ID=1CC2h)

      [E005555h]=F0h                            (force end of write/erase command)

Use if timeout occurred during "wait until" periods, for Macronix devices only.
Bank Switching (devices bigger than 64K only)

      [E005555h]=AAh, [E002AAAh]=55h, [E005555h]=B0h  (select bank command)
      [E000000h]=bnk                                  (write bank number 0..1)

Specifies 64K bank number for read/write/erase operations.
Required because gamepak flash/sram addressbus is limited to 16bit width.
Device Types
Nintendo puts different FLASH chips in commercial game cartridges. Developers should thus detect & support all chip types. For Atmel chips it'd be recommended to simulate 4K sectors by software, though reportedly Nintendo doesn't use Atmel chips in newer games anymore. Also mind that different timings should not disturb compatibility and performance.

      ID     Name       Size  Sectors  AverageTimings  Timeouts/ms   Waits
      D4BFh  SST        64K   16x4K    20us?,?,?       10,  40, 200  3,2
      1CC2h  Macronix   64K   16x4K    ?,?,?           10,2000,2000  8,3
      1B32h  Panasonic  64K   16x4K    ?,?,?           10, 500, 500  4,2
      3D1Fh  Atmel      64K   512x128  ?,?,?           ...40..,  40  8,8
      1362h  Sanyo      128K  ?        ?,?,?           ?    ?    ?    ?
      09C2h  Macronix   128K  ?        ?,?,?           ?    ?    ?    ?

Identification Codes MSB=Device Type, LSB=Manufacturer.
Size in bytes, and numbers of sectors * sector size in bytes.
Average medium Write, Erase Sector, Erase Chips timings are unknown?
Timeouts in milliseconds for Write, Erase Sector, Erase Chips.
Waitstates for Writes, and Reads in clock cycles.
Accessing FLASH Memory
FLASH memory is located in the "SRAM" area at E000000h..E00FFFFh, which is restricted to 16bit address and 8bit data buswidths. Respectively, the memory can be accessed <only> by 8bit read/write LDRB/STRB opcodes.
Also, reading anything (data or status/busy information) can be done <only> by opcodes executed in WRAM (not from opcodes in ROM) (there's no such restriction for writing).
FLASH Waitstates
Use 8 clk waitstates for initial detection (WAITCNT Bits 0,1 both set). After detection of certain device types smaller wait values may be used for write/erase, and even smaller wait values for raw reading, see Device Types table.
In practice, games seem to use smaller values only for write/erase (even though those operations are slow anyways), whilst raw reads are always done at 8 clk waits (even though reads could actually benefit slightly from smaller wait values).
Verify Write/Erase and Retry
Even though device signalizes the completion of write/erase operations, it'd be recommended to read/confirm the content of the changed memory area by software. In practice, Nintendo's "erase-write-verify-retry" function typically repeats the operation up to three times in case of errors.
Also, for SST devices only, the "erase-write" and "erase-write-verify-retry" functions repeat the erase command up to 80 times, additionally followed by one further erase command if no retries were needed, otherwise followed by six further erase commands.
Note
FLASH (64Kbytes) is used by the game Sonic Advance, and possibly others.

GBA Cart Backup DACS

128 KBytes - 1Mbit DACS - Lifetime: 100,000 writes.
1024 KBytes - 8Mbit DACS - Lifetime: 100,000 writes.
DACS (Debugging And Communication System) is used in Nintendo's hardware debugger only, DACS is NOT used in normal game cartridges.
Parts of DACS memory is used to store the debugging exception handlers (entry point/size defined in cartridge header), the remaining memory could be used to store game positions or other data. The address space is the upper end of the 32MB ROM area, the memory can be read directly by the CPU, including for ability to execute program code in this area.

GBA Cart I/O Port (GPIO)

4bit General Purpose I/O Port (GPIO) - contained in the ROM-chip
Used by Boktai for RTC and Solar Sensor:
GBA Cart Real-Time Clock (RTC)
GBA Cart Solar Sensor
And by Warioware Twisted for Rumble and Z-Axis Sensor:
GBA Cart Rumble
GBA Cart Gyro Sensor
Might be also used by other games for other purposes, such like other sensors, or SRAM bank switching, etc.
The I/O registers are mapped to a 6-byte region in the ROM-area at 80000C4h, the 6-byte region should be zero-filled in the ROM-image. In Boktai, the size of the zero-filled region is 0E0h bytes - that probably due to an incorrect definition (the additional bytes do not contain any extra ports, nor mirrors of the ports in the 6-byte region). Observe that ROM-bus writes are limited to 16bit/32bit access (STRB opcodes are ignored; that, only in DS mode?).
80000C4h - I/O Port Data (selectable W or R/W)

      bit0-3  Data Bits 0..3 (0=Low, 1=High)
      bit4-15 not used (0)

80000C6h - I/O Port Direction (for above Data Port) (selectable W or R/W)

      bit0-3  Direction for Data Port Bits 0..3 (0=In, 1=Out)
      bit4-15 not used (0)

80000C8h - I/O Port Control (selectable W or R/W)

      bit0    Register 80000C4h..80000C8h Control (0=Write-Only, 1=Read/Write)
      bit1-15 not used (0)

In write-only mode, reads return 00h (or possible other data, if the rom contains non-zero data at that location).
Connection Examples

      GPIO       | Boktai  | Wario
      Bit Pin    | RTC SOL | GYR RBL
      -----------+---------+---------
      0   ROM.1  | SCK CLK | RES -
      1   ROM.2  | SIO RST | CLK -
      2   ROM.21 | CS  -   | DTA -
      3   ROM.22 | -   FLG | -   MOT
      -----------+---------+---------
      IRQ ROM.43 | IRQ -   | -   -

Aside from the I/O Port, the ROM-chip also includes an inverter (used for inverting the RTC /IRQ signal), and some sort of an (unused) address decoder output (which appears to be equal or related to A23 signal) (ie. reacting on ROM A23, or SRAM D7, which share the same pin on GBA slot).

GBA Cart Real-Time Clock (RTC)

S3511 - 8pin RTC with 3-wire serial bus (used in Boktai)
The RTC chip is (almost) the same as used in NDS consoles:
DS Real-Time Clock (RTC)
The chip is accessed via 4bit I/O port (only 3bits are used for RTC):
GBA Cart I/O Port (GPIO)
Comparision of RTC Registers

      NDS_________GBA_________GBA/Params___
      stat2       control     (1-byte)
      datetime    datetime    (7-byte)
      time        time        (3-byte)
      stat1       force reset (0-byte)
      clkadjust   force irq   (0-byte)
      alarm1/int1 always FFh  (boktai contains code for writing 1-byte to it)
      alarm2      always FFh  (unused)
      free        always FFh  (unused)

Control Register

      Bit Dir Expl.
      0   -   Not used
      1   R/W IRQ duty/hold related?
      2   -   Not used
      3   R/W Per Minute IRQ (30s duty)        (0=Disable, 1=Enable)
      4   -   Not used
      5   R/W Unknown?
      6   R/W 12/24-hour Mode                  (0=12h, 1=24h) (usually 1)
      7   R   Power-Off (auto cleared on read) (0=Normal, 1=Failure)

Setting after Battery-Shortcut is 82h. Setting after Force-Reset is 00h.
Unused bits seem to be always zero, but might be read-only or write-only?
Datetime and Time Registers
Same as NDS, except AM/PM flag moved from hour.bit6 (NDS) to hour.bit7 (GBA).
Force Reset/Irq Registers
Used to reset all RTC registers (all used registers become 00h, except day/month which become 01h), or to drag the IRQ output LOW for a short moment. These registers are strobed by ANY access to them, ie. by both writing to, as well as reading from these registers.
Pin-Outs / IRQ Signal
The package has identical pin-outs as in NDS, although it is slightly larger than the miniature chip in the DS.
For whatever reason, the RTC's /IRQ output is passed through an inverter (contained in the ROM-chip), the inverted signal is then passed to the /IRQ pin on the cartridge slot. So, IRQ's will be triggered on the "wrong" edge - possible somehow in relation with detecting cartridge-removal IRQs?

GBA Cart Solar Sensor

Uses a Photo Diode as Solar Sensor (used in Boktai, allowing to defeat vampires when the cartridge is exposed to sunlight). The cartridge comes in transparent case, and it's slightly longer than normal carts, so the sensor reaches out of the cartridge slot. According to the manual, the sensor works only with sunlight, but actually it works with any strong light source (eg. a 100 Watt bulb at 1-2 centimeters distance). The sensor is accessed via 4bit I/O port (only 3bits used), which is contained in the ROM-chip.
GBA Cart I/O Port (GPIO)
A/D Conversion
The cartridge uses a self-made A/D converter, which is (eventually) better than measuring a capacitor charge-up time, and/or less expensive than a real ADC-chip:
It contains a 74LV4040 12bit binary counter (clocked by CPU via the I/O port), of which only the lower 8bit are used, which are passed to a resistor ladder-type D/A converter, which is generating a linear increasing voltage, which is passed to a TLV272 voltage comparator, which is passing a signal to the I/O port when the counter voltage becomes greater than the sensor voltage.
Example Code

      strh  0001h,[80000c8h] ;-enable R/W mode
      strh  0007h,[80000c6h] ;-init I/O direction
      strh  0002h,[80000c4h] ;-reset counter to zero (high=reset) (I/O bit0)
      strh  0000h,[80000c4h] ;-clear reset (low=normal)
      mov   r0,0             ;-initial level
     @@lop:
      strh  0001h,[80000c4h] ;-clock high ;\increase counter      (I/O bit1)
      strh  0000h,[80000c4h] ;-clock low  ;/
      ldrh  r1,[80000c4h]    ;-read port                          (I/O bit3)
      tst   r1,08h           ;\
      addeq r0,1             ; loop until voltage match (exit with r0=00h..FFh),
      tsteq r0,100h          ; or until failure/timeout (exit with r0=100h)
      beq   @@lop            ;/

The results vary depending on the clock rate used. In above example, ensure that IRQs or DMAs do not interrupt the function. Alternately, use a super-slow clock rate (eg. like 666Hz used in Boktai) so that additional small IRQ/DMA delays have little effect on the overall timing. Results should be somewhat:

      E8h  total darkness (including LED light, or daylight on rainy days)
      Dxh  close to a 100 Watt Bulb
      5xh  reaches max level in boktai's solar gauge
      00h  close to a tactical nuclear bomb dropped on your city

The exact values may change from cartridge to cartridge, so it'd be recommened to include a darkness calibration function, prompting the user to cover the sensor for a moment (in Boktai, access Options by pressing left/right in title screen) (alternately, auto-calibration could theoretically memorize the darkest in-game level ever seen).

GBA Cart Tilt Sensor

Yoshi's Universal Gravitation / Yoshi Topsy Turvy (X/Y-Axis)
Koro Koro Puzzle (probably same as Yoshi, X/Y-Axis, too) (?)
Yoshi-Type (X/Y-Axis)
All of the registers are one byte wide, mapped into the top "half" of the SRAM memory range.

      E008000h (W) Write 55h to start sampling
      E008100h (W) Write AAh to start sampling
      E008200h (R) Lower 8 bits of X axis
      E008300h (R) Upper 4 bits of X axis, and Bit7: ADC Status (0=Busy, 1=Ready)
      E008400h (R) Lower 8 bits of Y axis
      E008500h (R) Upper 4 bits of Y axis

You must set SRAM wait control to 8 clocks to access it correctly.
You must also set the cartridge PHI terminal to 4 MHz to make it work.
Sampling routine (typically executed once a frame during VBlank):

      wait until [E008300h].Bit7=1 or until timeout ;wait ready
      x = ([E008300h] AND 0Fh)*100h + [E008200h]    ;get x
      y = ([E008500h] AND 0Fh)*100h + [E008400h]    ;get y
      [E008000h]=55h, [E008100h]=AAh                ;start next conversion

Example values (may vary on different carts and on temperature, etc):

      X ranged between 0x2AF to 0x477, center at 0x392.    Huh?
      Y ranged between 0x2C3 to 0x480, center at 0x3A0.    Huh?

Thanks to Flubba for Yoshi-Type information.
Unknown if the Yoshi-Type sensors are sensing rotation, or orientation, or motion, or something else? In case of rotation, rotation around X-axis would result in motion in Y-direction, so not too sure whether X and Y have which meaning?
Most probably, the sensors are measuring (both) static acceleration (gravity), and dynamic acceleration (eg. shaking the device left/right).
The X/Y values are likely to be mirrored depending on using a back-loading cartridge slot (original GBA), or front-loading cartridge slot (newer GBA SP, and NDS, and NDS-Lite).

GBA Cart Gyro Sensor

Warioware Twisted (Z-Axis Gyro Sensor, plus Rumble)
Wario-Type (Z-Axis)
Uses a single-axis sensor, which senses rotation around the Z-axis. The sensor is connected to an analogue-in, serial-out ADC chip, which is accessed via lower 3 bits of the GPIO,
GBA Cart I/O Port (GPIO)
The four I/O Lines are connected like so,

      GPIO.Bit0 (W) Start Conversion
      GPIO.Bit1 (W) Serial Clock
      GPIO.Bit2 (R) Serial Data
      GPIO.Bit3 (W) Used for Rumble (not gyro related)

There should be at least <three sequential 32bit ARM opcodes executed in WS0 region> between the STRH opcodes which toggle the CLK signal. Wario uses WAITCNT=45B7h (SRAM=8clks, WS0/WS1/WS2=3,1clks, Prefetch=On, PHI=Off).
The data stream consists of: 4 dummy bits (usually zero), followed by 12 data bits, followed by endless unused bits (usually zero).

     read_gyro:
      mov  r1,8000000h      ;-cartridge base address
      mov  r0,01h           ;\enable R/W access
      strh r0,[r1,0c8h]     ;/
      mov  r0,0bh           ;\init direction (gpio2=input, others=output)
      strh r0,[r1,0c6h]     ;/
      ldrh r2,[r1,0c4h]     ;-get current state (for keeping gpio3=rumble)
      orr  r2,3                     ;\
      strh r2,[r1,0c4h] ;gpio0=1    ; start ADC conversion
      bic  r2,1                     ;
      strh r2,[r1,0c4h] ;gpio0=0    ;/
      mov  r0,00010000h ;stop-bit           ;\
      bic  r2,2                             ;
     @@lop:                                 ;
      ldrh r3,[r1,0c4h] ;get gpio2=data     ; read 16 bits
      strh r2,[r1,0c4h] ;gpio1=0=clk=low    ; (4 dummy bits, plus 12 data bits)
      movs r3,r3,lsr 3  ;gpio2 to cy=data   ;
      adcs r0,r0,r0     ;merge data, cy=done;
      orr  r3,r2,2      ;set bit1 and delay ;
      strh r3,[r1,0c4h] ;gpio1=1=clk=high   ;
      bcc  @@lop                            ;/
      bic  r0,0f000h                 ;-strip upper 4 dummy bits (isolate 12bit adc)
      bx   lr

Example values (may vary on different carts, battery charge, temperature, etc):

      354h  rotated in anti-clockwise direction (shock-speed)
      64Dh  rotated in anti-clockwise direction (normal fast)
      6A3h  rotated in anti-clockwise direction (slow)
      6C0h  no rotation                         (stopped)
      6DAh  rotation in clockwise direction     (slow)
      73Ah  rotation in clockwise direction     (normal fast)
      9E3h  rotation in clockwise direction     (shock-speed)

For detection, values 000h and FFFh would indicate that there's no sensor.
The Z-axis always points into same direction; no matter of frontloading or backloading cartridge slots.
Thanks to Momo Vampire for contributing a Wario cartridge.
X/Y/Z-Axes
X-Axis and Y-Axis are meant to be following the screens X and Y coordinates, so the Z-Axis would point into the screens depth direction.
DSi Cameras
DSi consoles can mis-use the built-in cameras as Gyro sensor (as done by the System Flaw DSi game).

GBA Cart Rumble

Warioware Twisted (Rumble, plus Z-Axis Gyro Sensor)
Drill Dozer (Rumble only) <-- and ALSO supports Gameboy Player rumble?
GBA Rumble Carts are containing a small motor, which is causing some vibration when/while it is switched on (that, unlike DS Rumble, which must be repeatedly toggled on/off).
In Warioware Twisted, rumble is controlled via GPIO.Bit3 (Data 0=Low=Off, 1=High=On) (and Direction 1=Output), the other GPIO Bits are used for the gyro sensor.
GBA Cart I/O Port (GPIO)
Note: GPIO3 is connected to an external pulldown resistor (so the HighZ level gets dragged to Low=Off when direction is set to Input).
Unknown if Drill Dozer is controlled via GPIO.Bit3, too?
DS Rumble Pak
Additionally, there's a Rumble Pak for the NDS, which connects to the GBA slot, so it can be used also for GBA games (provided that the game doesn't require the GBA slot, eg. GBA multiboot games).
DS Cart Rumble Pak
Gamecube Rumble
Moreover, GBA games that are running on a Gameboy Player are having access to the Rumble function of Gamecube joypads.
GBA Gameboy Player

GBA Cart e-Reader

GBA Cart e-Reader Overview
GBA Cart e-Reader I/O Ports
GBA Cart e-Reader Dotcode Format
GBA Cart e-Reader Data Format
GBA Cart e-Reader Program Code
GBA Cart e-Reader API Functions
GBA Cart e-Reader VPK Decompression
GBA Cart e-Reader Error Correction
GBA Cart e-Reader File Formats

       ________________
      |   ShortStrip   |
      |L              L|
      |o    Center    o|
      |n    Region    n|
      |g              g|
      |  may contain   |
      |S   pictures,  S|
      |t instructions t|
      |r     etc.     r|
      |i              i|
      |p              p|
      |___ShortStrip___|

GBA Cart e-Reader Overview

The e-Reader is a large GBA cartridge (about as big as the GBA console), with built-in dotcode scanning hardware. Dotcodes are tiny strips of black and white pixels printed on the edges of cardboard cards. The cards have to be pulled through a slot on the e-Reader, which is giving it a feeling like using a magnet card reader. The binary data on the dotcodes contains small games, either in native GBA code (ARM/THUMB), or in software emulated 8bit Z80 or NES/Famicom (6502) code.
The e-Reader Hardware
The hardware consists of regular 8MByte ROM and 128KByte FLASH chips, two link ports, a custom PGA chip, the camera module (with two red LEDs, used as light source), and some analogue components for generating the LED voltages, etc. The camera supports 402x302 pixels with 7bit monochrome color depth, but the PGA clips it to max 320 pixels per scanline with 1bit color depth.
Link Port Plug/Socket
The e-Reader's two link ports are simply interconnected with each other; without connection to the rest of the e-Reader hardware. These ports are used only on the original GBA (where the large e-Reader cartridge would be covering the GBA's link socket). When trying to insert the e-Reader into an original NDS (or GBA-Micro), then the e-Reader's link plug will hit against the case of the NDS, so it works only with some minor modification to the hardware. There's no such problem with GBA-SP and NDS-Lite.
Region/Version
There are 3 different e-Reader's: Japanese/Original, Japanese/Plus, and Non-Japanese. The Original version has only 64K FLASH, no Link Port, and reportedly supports only Z80 code, but no NES/GBA code. The Plus and Non-Japanese versions should be almost identical, except that they reject cards from the wrong region, and that the title strings aren't ASCII in Japan, the Plus version should be backwards compatible to the Original one.
The Problem
Nintendo's current programmers are definetly unable to squeeze a Pac-Man style game into less than 4MBytes. Their solution has been: MORE memory. That is, they've put a whopping 8MByte BIOS ROM into the e-Reader, which contains the User Interface, and software emulation for running some of their 20 years old 8bit NES and Game&Watch titles, which do fit on a few dotcode strips.

GBA Cart e-Reader I/O Ports

DF80000h Useless Register (R/W)

      0     Output to PGA.Pin93 (which seems to be not connected to anything)
      1-3   Unknown, read/write-able (not used by e-Reader BIOS)
      4-15  Always zero (0)

DFA0000h Reset Register (R/W)

      0    Always zero              (0)
      1    Reset Something?         (0=Normal, 1=Reset)
      2    Unknown, always set      (1)
      3    Unknown, read/write-able (not used by e-Reader BIOS)
      4-7  Always zero              (0)
      8    Unknown, read/write-able (not used by e-Reader BIOS)
      9-15 Always zero              (0)

DFC0000h..DFC0027h Scanline Data (R)
Scanline data (40 bytes, for 320 pixels, 1bit per pixel, 0=black, 1=white).
The first (leftmost) pixel is located in the LSB of the LAST byte.
Port E00FFB1h.Bit1 (and [4000202h].Bit13) indicates when a new scanline is present, the data should be then transferred to RAM via DMA3 (SAD=DFC0000h, DAD=buf+y*28h, CNT=80000014h; a slower non-DMA transfer method would result in missed scanlines). After the DMA, software must reset E00FFB1h.Bit1.
Note: The scanning resolution is 1000 DPI.
DFC0028h+(0..2Fh*2) Brightest Pixels of 8x6 Blocks (R)

      0-6  Max Brightness (00h..7Fh; 00h=All black, 7Fh=One or more white)
      7-15 Always zero

Can be used to adjust the Port E00FF80h..E00FFAFh settings.
DFC0088h Darkest Pixel of whole Image (R)

      0-7  Max Darkness   (00h..7Fh; 00h=One or more black, 7Fh=All white)
      8-15 Always zero

Can be used to adjust the Port E00FF80h..E00FFAFh settings.
E00FF80h..E00FFAFh Intensity Boundaries for 8x6 Blocks (R/W)
The 320x246 pixel camera input is split into 8x6 blocks (40x41 pixels each), with Block00h=Upper-right, Block07h=Upper-left, ..., Block27h=Lower-left. The boundary values for the separate blocks are used for 128-grayscale to 2-color conversion, probably done like "IF Pixel>Boundary THEN white ELSE black".

      0-6  Block Intensity Boundaries (0..7Fh; 7Fh=Whole block gets black)
      7    Always zero

The default boundary values are stored in FLASH memory, the values are typically ranging from 28h (outer edges) to 34h (center image), that in respect to the light source (the two LEDs are emitting more light to the center region).
E00FFB0h Control Register 0 (R/W)

      0    Serial Data       (Low/High)
      1    Serial Clock      (Low/High)
      2    Serial Direction  (0=Input, 1=Output)
      3    Led/Irq Enable    (0=Off, 1=On; Enable LED and Gamepak IRQ)
      4    Start Scan        (0=Off, 1=Start) (0-to-1 --> Resync line 0)
      5    Phi 16MHz Output  (0=Off, 1=On; Enable Clock for Camera, and for LED)
      6    Power 3V Enable   (0=Off, 1=On; Enable 3V Supply for Camera)
      7    Not used          (always 0) (sometimes 1) (Read only)

E00FFB1h Control Register 1 (R/W)

      0    Not used          (always 0)
      1    Scanline Flag     (1=Scanline Received, 0=Acknowledge)
      2-3  Not used          (always 0)
      4    Strange Bit       (0=Normal, 1=Force Resync/Line0 on certain interval?)
      5    LED Anode Voltage (0=3.0V, 1=5.1V; requires E00FFB0h.Bit3+5 to be set)
      6    Not used          (always 0)
      7    Input from PGA.Pin22, always high (not used by e-Reader) (Read Only)

Bit1 can be SET by hardware only, software can only RESET that bit, the Gamepak IRQ flag (Port 4000202h.Bit13) becomes set on 0-to-1 transitions.
E00FFB2h Light Source LED Kathode Duration (LSB) (R/W)
E00FFB3h Light Source LED Kathode Duration (MSB) (R/W)
Selects the LED Kathode=LOW Duration, aka the LED=ON Duration. That does act as pulse width modulated LED brightness selection (the camera seems to react slowly enough to view the light as being dimmed to medium, rather than seeing the actual light ON and OFF states). The PWM timer seems to be clocked at 8MHz. The hardware clips timer values 2000h..FFFFh to max 2000h (=1ms). Additionally, the e-Reader BIOS clips values to max 11B3h. Default setting is found in FLASH calibration data. A value of 0000h disables the LED.
Serial Port Registers (Camera Type 1) (DV488800) (calib_data[3Ch]=1)
All 16bit values are ordered MSB,LSB. All registers are whole 8bit Read/Write-able, except 00h,57h-5Ah (read only), and 53h-55h (2bit only).

      Port     Expl.               (e-Reader Setting)
      00h      Maybe Chip ID (12h) (not used by e-Reader BIOS) (Read Only)
      01h                          (05h)    ;-Bit0: 1=auto-repeat scanning?
      02h                          (0Eh)
      10h-11h  Vertical Scroll     (calib_data[30h]+7)
      12h-13h  Horizontal Scroll   (0030h)
      14h-15h  Vertical Size       (00F6h=246)
      16h-17h  Horizontal Size     (0140h=320)
      20h-21h  H-Blank Duration    (00C4h)
      22h-23h                      (0400h)  ;-Upper-Blanking in dot-clock units?
      25h                          (var)    ;-bit1: 0=enable [57h..5Ah] ?
      26h                          (var)    ;\maybe a 16bit value
      27h                          (var)    ;/
      28h                          (00h)
      30h      Brightness/contrast (calib_data[31h]+/-nn)
      31h-33h                      (014h,014h,014h)
      34h      Brightness/contrast (02h)
      50h-52h  8bit Read/Write     (not used by e-Reader BIOS)
      53h-55h  2bit Read/Write     (not used by e-Reader BIOS)
      56h      8bit Read/Write     (not used by e-Reader BIOS)
      57h-58h  16bit value, used to autodetect/adjust register[30h] (Read Only)
      59h-5Ah  16bit value, used to autodetect/adjust register[30h] (Read Only)
      80h-FFh  Mirrors of 00h..7Fh (not used by e-Reader BIOS)

All other ports are unused, writes to those ports are ignored, and reads are returning data mirrored from other ports; that is typically data from 2 or more ports, ORed together.
Serial Port Registers (Camera Type 2) (calib_data[3Ch]=2)
All 16bit values are using more conventional LSB,MSB ordering, and port numbers are arranged in a more reasonable way. The e-Reader BIOS doesn't support (or doesn't require) brightness adjustment for this camera module.

      Port     Expl.             (e-Reader Setting)
      00h                        (22h)
      01h                        (50h)
      02h-03h  Vertical Scroll   (calib_data[30h]+28h)
      04h-05h  Horizontal Scroll (001Eh)
      06h-07h  Vertical Size     (00F6h)    ;=246
      08h-09h  Horizontal Size   (0140h)    ;=320
      0Ah-0Ch                    (not used by e-Reader BIOS)
      0Dh                        (01h)
      0Eh-0Fh                    (01EAh)    ;=245*2
      10h-11h                    (00F5h)    ;=245
      12h-13h                    (20h,F0h)  ;maybe min/max values?
      14h-15h                    (31h,C0h)  ;maybe min/max values?
      16h                        (00h)
      17h-18h                    (77h,77h)
      19h-1Ch                    (30h,30h,30h,30h)
      1Dh-20h                    (80h,80h,80h,80h)
      21h-FFh                    (not used by e-Reader BIOS)

This appears to be a Micron (aka Aptina) camera (resembling the DSi cameras).
My own e-Reader uses a Type 1 camera module. Not sure if Nintendo has ever manufactured any e-Readers with Type 2 cameras?
Calibration Data in FLASH Memory (Bank 0, Sector 0Dh)

      E00D000 14h  ID String ('Card-E Reader 2001',0,0)
      E00D014 2    Sector Checksum (NOT(x+x/10000h); x=sum of all other halfwords)

Begin of actual data (40h bytes)

      E00D016 8x6  [00h] Intensity Boundaries for 8x6 blocks ;see E00FF80h..AFh
      E00D046 1    [30h] Vertical scroll (0..36h)  ;see type1.reg10h/type2.reg02h
      E00D047 1    [31h] Brightness or contrast    ;see type1.reg30h
      E00D048 2    [32h] LED Duration              ;see E00FFB2h..B3h
      E00D04A 2    [34h] Not used?   (0000h)
      E00D04C 2    [36h] Signed value, related to adjusting the 8x6 blocks
      E00D04E 4    [38h] Not used?   (00000077h)
      E00D052 4    [3Ch] Camera Type (0=none,1=DV488800,2=Whatever?)

Remaining bytes in this Sector...

      E00D056 FAAh Not used (zerofilled) (included in above checksum)

Flowchart for Overall Camera Access
ereader_scan_camera:

     call ereader_power_on
     call ereader_initialize
     for z=1 to number_of_frames
      for y=0 to 245
       Wait until E00FFB1h.Bit1 gets set by hardware (can be handled by IRQ)
       Copy 14h halfwords from DFC0000h to buf+y*28h via DMA3
       Reset E00FFB1h.Bit1 by software
      next y
      ;(could now check DFC0028h..DFC0086h/DFC0088h for adjusting E00FF00h..2Fh)
      ;(could now show image on screen, that may require to stop/pause scanning)
     next z
     call ereader_power_off
     Ret

ereader_power_on:

     [4000204h]=5803h   ;Init waitstates, and enable Phi 16MHz
     [DFA0000h].Bit1=1
     Wait(10ms)
     [E00FFB0h]=40h     ;Enable Power3V and reset other bits
     [DFA0000h].Bit1=0
     [E00FFB1h]=20h     ;Enable Power5V and reset other bits
     Wait(40ms)
     [E00FFB1h].Bit4=0  ;...should be already 0 ?
     [E00FFB0h]=40h+27h ;Phi16MHz=On, SioDtaClkDir=HighHighOut
     Ret

ereader_power_off:

     [E00FFB0h]=04h    ;Power3V=Off, Disable Everything, SioDtaClkDir=LowLowOut
     [DFA0000h].Bit1=0 ;...should be already 0
     [E00FFB1h].Bit5=0 ;Power5V=Off
     Ret

ereader_initialize:

     IF calib_data[3Ch] AND 03h = 1 THEN init_camera_type1
     [E00FFB0h].Bit4=1 ;ScanStart
     IF calib_data[3Ch] AND 03h = 2 THEN init_camera_type2
     Copy calib_data[00h..2Fh] to [E00FF80h+00h..2Fh]  ;Intensity Boundaries
     Copy calib_data[32h..33h] to [E00FFB2h+00h..01h]  ;LED Duration LSB,MSB
     [E00FFB0h].Bit3=1                                 ;LedIrqOn
     Ret

init_camera_type1:

     x=MIN(0,calib_data[31h]-0Bh)
     Set Sio Registers (as shown for Camera Type 1, except below values...)
     Set Sio Registers [30h]=x [25h]=04h, [26h]=58h, [27h]=6Ch
     ;(could now detect/adjust <x> based on Sio Registers [57h..5Ah])
     Set Sio Registers [30h]=x [25h]=06h, [26h]=E8h, [27h]=6Ch
     Ret

init_camera_type2:

     Wait(0.5ms)
     Set Sio Registers (as shown for Camera Type 2)
     Ret

Accessing Serial Registers via E00FFB0h

          Begin   Write(A) Write(B) Read(C) Read(D) End     Idle    PwrOff
      Dir ooooooo ooooooo  ooooooo  iiiiiii iiiiiii ooooooo ooooooo ooooooo
      Dta ---____ AAAAAAA  BBBBBBB  xxxxxCx xxxxxDx ______- ------- _______
      Clk ------_ ___---_  ___---_  ___---_ ___---_ ___---- ------- _______

Flowchart for accessing Serial Registers via E00FFB0h (looks like I2C bus)

     Delay:
      Wait circa 2.5us, Ret
     SioBegin:
      SioDta=1, SioDir=Out, SioClk=1, Delay, SioDta=0, Delay, SioClk=0, Ret
     SioEnd:
      SioDta=0, SioDir=Out, Delay, SioClk=1, Delay, SioDta=1, Ret
     SioRead1bit:   ;out: databit
      SioDir=In, Delay, SioClk=1, Delay, databit=SioDta, SioClk=0, Ret
     SioWrite1bit:  ;in: databit
      SioDta=databit, SioDir=Out, Delay, SioClk=1, Delay, SioClk=0, Ret
     SioReadByte:   ;in: endflag - out: data
      for i=7 to 0, data.bit<i>=SioRead1bit, next i, SioWrite1bit(endflag), Ret
     SioWriteByte:  ;in: data - out: errorflag
      for i=7 to 0, Delay(huh/why?), SioWrite1bit(data.bit<i>), next i
      errorflag=SioRead1bit, SioDir=Out(huh/why?), Ret
     SioWriteRegisters:  ;in: index, len, buffer
      SioBegin
      SioWriteByte(22h)        ;command (set_index) (and write_data)
      SioWriteByte(index)      ;index
      for i=0 to len-1
       SioWriteByte(buffer[i]) ;write data (and auto-increment index)
      next
      SioEnd
      ret
     SioReadRegisters:   ;in: index, len - out: buffer
      SioBegin
      SioWriteByte(22h)        ;command (set_index) (without any write_data here)
      SioWriteByte(index)      ;index
      SioBegin
      SioWriteByte(23h)        ;command (read_data) (using above index)
      for i=0 to len-1
       if i=len-1 then endflag=1 else endflag=0
       buffer[i]=SioReadByte(endflag)  ;read data (and auto-increment index)
      next
      SioEnd
      Ret

Caution: Accessing the SIO registers appears highly unstable, and seems to require error handling with retries. Not sure what is causing that problem, possibly the registers cannot be accessed during camera-data-scans...?
WAITCNT
The e-Reader BIOS uses WAITCNT [4000204h]=5803h when accessing the PGA, that is, gamepak 16.78MHz phi output (bit11-12=3), 8 waits for SRAM region (bit0-1=3), gamepak prefetch enabled (bit14=1), also sets WS0 to 4,2 waits (bit2-4=0), and sets WS2 to odd 4,8 waits (bit8-10=0). The WS2 (probably WS0 too) settings are nonsense, and should work with faster timings (the e-Reader can be accessed in NDS mode, which doesn't support that slow timings).
e-Reader Memory and I/O Map (with all used/unused/mirrored regions)

      C000000h-C7FFFFFh  ROM (8MB)
      C800000h-DF7FFFFh  Open Bus
      DF80000h-DF80001h  Useless Register (R/W)
      DF80002h-DF9FFFFh  Mirrors of DF80000h-DF80001h
      DFA0000h-DFA0001h  Reset Register (R/W)
      DFA0002h-DFBFFFFh  Mirrors of DFA0000h-DFA0001h
      DFC0000h-DFC0027h  Scanline Data (320 Pixels) (R)
      DFC0028h-DFC0087h  Brightest Pixels of 8x6 Blocks (R)
      DFC0088h           Darkest Pixel of whole Image (R)
      DFC0089h-DFC00FFh  Always zero
      DFC0100h-DFDFFFFh  Mirrors of DFC0000h-DFC00FFh
      DFE0000h-DFFFFFFh  Open Bus
      E000000h-E00CFFFh  FLASH Bank 0 - Data
      E00D000h-E00DFFFh  FLASH Bank 0 - Calibration Data
      E00E000h-E00EFFFh  FLASH Bank 0 - Copy of Calibration Data
      E00F000h-E00FF7Fh  FLASH Bank 0 - Unused region
      E000000h-E00EFFFh  FLASH Bank 1 - Data
      E00F000h-E00FF7Fh  FLASH Bank 1 - Unused region
      E00FF80h-E00FFAFh  Intensity Boundaries for 8x6 Blocks (R/W)
      E00FFB0h           Control Register 0 (R/W)
      E00FFB1h           Control Register 1 (R/W)
      E00FFB2h-E00FFB3h  LED Duration (16bit) (R/W)
      E00FFB4h-E00FFBFh  Always zero
      E00FFC0h-E00FFFFh  Mirror of E00FF80h-E00FFBFh

Mind that WS2 should be accessed by LDRH/STRH, and SRAM region by LDRB/STRB.
Additionally about 32 serial bus registers are contained in the camera module.
Camera Module Notes
The Type 1 initial setting on power-on is 402x302 pixels, the e-Reader uses only 320x246 pixels. The full vertical resolution could be probably used without problems. Port DFC0000h-DFC0027h are restricted to 320 pixels, so larger horizontal resolutions could be probably obtained only by changing the horizontal scroll offset on each 2nd scan.
The camera output is 128 grayscales (via parallel 7bit databus), but the PGA converts it to 2 colors (1bit depth). For still images, it might be possible to get 4 grayshades via 3 scans with different block intensity boundary settings.
No idea if the camera supports serial commands other than 22h and 23h. Namely, it <would> be a quite obvious and basic feature to allow to receive the bitmap via the 2-wire serial bus (alternately to the 7bit databus), if supported, it'd allow to get 7bit images, bypassing 1bit PGA conversion.
When used as actual camera (by cutting an opening in the case), the main problem is the 1bit color depth, which allows only black and white schemes, when/if solving that problem, focusing might be also a problem.
Either the camera or the PGA seem to have a problem on white-to-black transitions in vertical direction, the upper some black pixels are sorts of getting striped or dithered. For example, scanning the large sync marks appears as:

      Actual Shape    Scanned Shape
         XXXXX            X  X
        XXXXXXX           X  X X
       XXXXXXXXX        X X  X XX
       XXXXXXXXX        X X  X XX
        XXXXXXX          XXXXXXX
         XXXXX            XXXXX

That appears only on large black shapes (the smaller data dots look better). Probably the image is scanned from bottom upwards (and the camera senses only the initial transition at the bottom, and then looses track of what it is doing).

GBA Cart e-Reader Dotcode Format

Resolution is 342.39 DPI (almost 10 blocks per inch).
Resolution is 134.8 dots/cm (almost 4 blocks per centimeter).
The width and height of each block, and the spacing to the bottom edge of the card is ca. 1/10 inch, or ca. 4 millimeters.

       XXX            BLOCK 1             XXX            BLOCK 2             XXX
      XXXXX                              XXXXX                              XXXXX
      XXXXX   X X X X X X  X X X X X X   XXXXX   X X X X X X  X X X X X X   XXXXX
      XXXXX                              XXXXX                              XXXXX
       XXX   HHHHHHHHHHHHHHHHHHHH......   XXX   HHHHHHHHHHHHHHHHHHHH......   XXX
             ..........................         ..........................
             ...... 3 short lines .....         ..........................
        A..................................A..................................A..
        A....      26 long lines       ....A........ X = Sync Marks   ........A..
        A....  (each 34 data dots)     ....A........ H = Block Header ........A..
        A....(not all lines shown here)....A........ . = Data Bits    ........A..
        A..................................A........ A = Address Bits ........A..
             ...... 3 short lines .....         ..........................
             ...(each 26 data dots)....         ..........................
       XXX   ..........................   XXX   ..........................   XXX
      XXXXX                              XXXXX                              XXXXX
      XXXXX   X X X X X X  X X X X X X   XXXXX   X X X X X X  X X X X X X   XXXXX
      XXXXX                              XXXXX                              XXXXX
       XXX                                XXX                                XXX
                 <ca. 35 blank lines>
      ___Snip____________________________________________________________________

Address Columns
Each Column consists of 26 dots. From top to bottom: 1 black dot, 8 blank dots, 16 address dots (MSB topmost), and 1 blank dot. The 16bit address values can be calculated as:

      addr[0] = 03FFh
      for i = 1 to 53
        addr[i] = addr[i-1] xor ((i and (-i)) * 769h)
        if (i and 07h)=0 then addr[i] = addr[i] xor (769h)
        if (i and 0Fh)=0 then addr[i] = addr[i] xor (769h*2)
        if (i and 1Fh)=0 then addr[i] = addr[i] xor (769h*4) xor (769h)
      next i

Short strips use addr[1..19], long strips use addr[25..53], left to right.
Block Header
The 18h-byte Block Header is taken from the 1st two bytes (20 dots) of the 1st 0Ch blocks (and is then repeated in the 1st two bytes of further blocks).

      00h      Unknown              (00h)
      01h      Dotcode type         (02h=Short, 03h=Long)
      02h      Unknown              (00h)
      03h      Address of 1st Block (01h=Short, 19h=Long)
      04h      Total Fragment Size  (40h) ;64 bytes per fragment, of which,
                                          ;48 bytes are actual data, the remaining
      05h      Error-Info Size      (10h) ;16 bytes are error-info
      06h      Unknown              (00h)
      07h      Interleave Value     (1Ch=Short, 2Ch=Long)
      08h..17h 16 bytes Reed-solomon error correction info for Block Header

Data 4-Bit to 5-bit Conversion
In the Block Header (HHHHH), and Data Region (.....), each 4bit are expanded to 5bit, so one byte occupies 10 dots, and each block (1040 data dots) contains 104 bytes.

      4bit  00h 01h 02h 03h 04h 05h 06h 07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh
      5bit  00h 01h 02h 12h 04h 05h 06h 16h 08h 09h 0Ah 14h 0Ch 0Dh 11h 10h

That formatting ensures that there are no more than two continous black dots (in horizontal direction), neither inside of a 5bit value, nor between two 5bit values, however, the address bars are violating that rule, and up to 5 continous black dots can appear at the (..A..) block boundaries.
Data Order
Data starts with the upper bit of the 5bit value for the upper 4bit of the first byte, which is located at the leftmost dot of the upper line of the leftmost block, it does then extend towards rightmost dot of that block, and does then continue in the next line, until reaching the bottom of the block, and does then continue in the next block. The 1st two bytes of each block contain a portion of the Block Header, the remaining 102 bytes in each block contain data.
Data Size
A long strip consists of 28 blocks (28*104 = 2912 bytes), a short strip of 18 blocks (18*104 = 1872 bytes). Of which, less than 75% can be actually used for program code, the remaining data contains error correction info, and various headers. See Data Format for more info.
Interleaved Fragments
The Interleave Value (I) specifies the number of fragments, and does also specify the step to the next byte inside of a fragment; except that, at the block boundaries (every 104 bytes), the step is 2 bigger (for skipping the next two Block Header bytes).

      RAW Offset  Content
      000h..001h  1st 2 bytes of RAW Header
      002h        1st byte of 1st fragment
      003h        1st byte of 2nd fragment
      ...         ...
      002h+I-1    1st byte of last fragment
      002h+I      2nd byte of 1st fragment
      003h+I      2nd byte of 2nd fragment
      ...         ...
      002h+I*2-1  2nd byte of last fragment
      ...         ...

Each fragment consists of 48 actual data bytes, followed by 16 error correction bytes, followed by 0..2 unused bytes (since I*40h doesn't exactly match num_blocks*102).

GBA Cart e-Reader Data Format

Data Strip Format
The size of the data region is I*48 bytes (I=Interleave Value, see Dotcode Format), the first 48-byte fragment contains the Data Header, the remaining (I-1) fragments are Data Fragments (which contain title(s), and VPK compressed program code).
First Strip

      Data Header  (48 bytes)
      Main-Title   (17 bytes, or 33 bytes)
      Sub-Title(s) (3+18 bytes, or 33 bytes) (for each strip) (optional)
      VPK Size     (2 byte value, total length of VPK Data in ALL strips)
      NULL Value   (4 bytes, contained ONLY in 1st strip of GBA strips)
      VPK Data     (length as defined in VPK Size entry, see above)

Further Strip(s)

      Data Header  (48 bytes)
      Main-Title   (17 bytes, or 33 bytes)
      Sub-Title(s) (3+18 bytes, or 33 bytes) (for each strip) (optional)
      VPK Data     (continued from previous strip)

Data Header (30h bytes) (1st fragment)

      00h-01h  Fixed         (00h,30h)
      02h      Fixed         (01h)     ;01h="Do not calculate Global Checksum" ?
      03h      Primary Type  (see below)
      04h-05h  Fixed         (00h,01h) (don't care)
      06h-07h  Strip Size    (0510h=Short, 0810h=Long Strip) ((I-1)*30h) (MSB,LSB)
      08h-0Bh  Fixed         (00h,00h,10h,12h)
      0Ch-0Dh  Region/Type   (see below)
      0Eh      Strip Type    (02h=Short Strip, 01h=Long Strip) (don't care)
      0Fh      Fixed         (00h) (don't care)
      10h-11h  Unknown       (whatever) (don't care)
      12h      Fixed         (10h)     ;10h="Do calculate Data Checksum" ?
      13h-14h  Data Checksum (see below) (MSB,LSB)
      15h-19h  Fixed         (19h,00h,00h,00h,08h)
      1Ah-21h  ID String     ('NINTENDO')
      22h-25h  Fixed         (00h,22h,00h,09h)
      26h-29h  Size Info     (see below)
      2Ah-2Dh  Flags         (see below)
      2Eh      Header Checksum (entries [0Ch-0Dh,10h-11h,26h-2Dh] XORed together)
      2Fh      Global Checksum (see below)

Primary Type [03h] is 8bit,

      0      Card Type (upper bit) (see below)
      1      Unknown (usually opposite of Bit0) (don't care)
      2-7    Unknown (usually zero)

Region/Type [0Ch..0Dh] is 16bit,

      0-3    Unknown (don't care)
      4-7    Card Type (lower bits) (see below)
      8-11   Region/Version (0=Japan/Original, 1=Non-japan, 2=Japan/Plus)
      12-15  Unknown (don't care)

Size Info [26h-29h] is 32bit,

      0      Unknown            (don't care)
      1-4    Strip Number       (01h..Number of strips)
      5-8    Number of Strips   (01h..0Ch) (01h..08h for Japan/Original version)
      9-23   Size of all Strips (excluding Headers and Main/Sub-Titles)
             (same as "VPK Size", but also including the 2-byte "VPK Size" value,
             plus the 4-byte NULL value; if it is present)
      24-31  Fixed              (02h) (don't care)

Flags [2Ah-2Dh] is 32bit,

      0      Permission to save (0=Start Immediately, 1=Prompt for FLASH Saving)
      1      Sub-Title Flag     (0=Yes, 1=None)    (Japan/Original: always 0=Yes)
      2      Application Type   (0=GBA/Z80, 1=NES) (Japan/Original: always 0=Z80)
      3-31   Zero (0) (don't care)

Data Checksum [13h-14h] is the complement (NOT) of the sum of all halfwords in all Data Fragments, however, it's all done in reversed byte order: checksum is calculated with halfwords that are read in MSB,LSB order, and the resulting checksum is stored in MSB,LSB order in the Header Fragment.
Global Checksum [2Fh] is the complement (NOT) of the sum of the first 2Fh bytes in the Data Header plus the sum of all Data Fragment checksums; the Data Fragment checksums are all 30h bytes in a fragment XORed with each other.
Titles (3+N bytes, or N bytes)
Titles can be 33 bytes for both Main and Sub (Format 0Eh), or Main=17 bytes and Sub=3+18 bytes (Formats 02h..05h). In the 3+N bytes form, the first 3 bytes (24bit) are are used to display "stats" information in form of "HP: h1 ID: i1-i2-i3", defined as:

      Bit    Expl.
      0-3    h1, values 1..15 shown as "10..150", value 0 is not displayed
      4-6    i3, values 0..7 shown as "A..G,#"
      7-13   i2, values 0..98 shown as "01..99" values 99..127 as "A0..C8"
      14-18  i1, values 0..31 shown as "A..Z,-,_,{HP},.,{ID?},:"
      19-22  Unknown
      23     Disable stats (0=Show as "HP: h1 ID: i1-i2-i3", 1=Don't show it)

The N bytes portion contains the actual title, which must be terminated by 00h (so the max length is N-1 characters, if it is shorter than N-1, then the unused bytes are padded by further 00h's). The character set is normal ASCII for non-Japan (see Region/Version entry in header), and 2-byte SHIFT-JIS for Japanese long-titles (=max 16 2-byte chars) with values as so:

      00h          --> end-byte
      81h,40h      --> SPC
      81h,43h..97h --> punctuation marks
      82h,4Fh..58h --> "0..9"
      82h,60h..79h --> "A..Z"
      82h,81h..9Ah --> "a..z"

And 1-byte chars for Japanese short-titles,

      00     = end-byte
      01     = spc
      02..0B = 0..9
      0C..AF = japanese
      B0..B4 = dash, male, female, comma, round-dot
      B5..C0 = !"%&~?/+-:.'
      C1..DA = A..Z
      DB..DF = unused (blank)
      E0..E5 = japanese
      E6..FF = a..z
      N/A    = #$()*;<=>@[\]^_`{|}

Additionally to the Main-Title, optional Sub-Titles for each strip can be included (see Sub-Title Flag in header). If enabled, then ALL strip titles are included in each strip (allowing to show a preview of which strips have/haven't been scanned yet).
The e-Reader can display maximum of 8 sub-titles, if the data consists of more than 8 strips, then sub-titles aren't displayed (so it'd be waste of space to include them in the dotcodes).
The Main Title gets clipped to 128 pixels width (that are, circa 22 characters), and, the e-Reader BIOS acts confused on multi-strip games with Main Titles longer than 26 characters (so the full 33 bytes may be used only in Japan; with 16bit charset).
If the title is empty (00h-filled), and there is only one card in the application, then the application is started immediately. That, without allowing the user to save it in FLASH memory.
Caution: Although shorter Titles do save memory, they do act unpleasant: the text "(C) P-Letter" will be displayed at the bottom of the loading screen.
On Japanese/Original, 8bit sub-titles can be up to 18 characters (without any end-byte) (or less when stats are enabled, due to limited screen width).
Card Types (Primary Type.Bit0 and Region/Type.Bit12-15)

      00h..01h  Blank Screen (?)
      02h..03h  Dotcode Application with 17byte-title, with stats, load music A
      04h..05h  Dotcode Application with 17byte-title, with stats, load music B
      06h..07h  P-Letter Attacks
      08h..09h  Construction Escape
      0Ah..0Bh  Construction Action
      0Ch..0Dh  Construction Melody Box
      0Eh       Dotcode Application with 33byte-title, without stats, load music A
      0Fh       Game specific cards
      10h..1Dh  P-Letter Viewer
      1Eh..1Fh  Same as 0Eh and 0Fh (see above)

The 'Application' types are meant to be executable GBA/Z80/NES programs.

GBA Cart e-Reader Program Code

The GBA/Z80/NES program code is stored in the VPK compressed area.
NES-type is indicated by header [2Ah].Bit2, GBA-type is indicated by the NULL value inserted between VPK Size and VPK Data, otherwise Z80-type is used.
GBA Format
Load Address and Entrypoint are at 2000000h (in ARM state). The 32bit word at 2000008h is eventually destroyed by the e-Reader. Namely,

      IF e-Reader is Non-Japanese,
      AND [2000008h] is outside of range of 2000000h..20000E3h,
      AND only if booted from camera (not when booted from FLASH?),
      THEN [2000008h]=[2000008h]-0001610Ch ELSE [2000008h] kept intact

Existing multiboot-able GBA binaries can be converted to e-Reader format by,

      Store "B 20000C0h" at 2000000h   ;redirect to RAM-entrypoint
      Zerofill 2000004h..20000BFh      ;erase header (for better compression rate)
      Store 01h,01h at 20000C4h        ;indicate RAM boot

The GBA code has full access to the GBA hardware, and may additionally use whatever API functions contained in the e-Reader BIOS. With the incoming LR register value, "mov r0,N, bx lr" returns to the e-Reader BIOS (with N being 0=Restart, or 2=To_Menu). No idea if it's necessary to preserve portions of RAM when returning to the e-Reader BIOS?
Caution: Unlike for normal GBA cartridges/multiboot files, the hardware is left uninitialized when booting dotcodes (among others: sound DMA is active, and brightness is set to zero), use "mov r0,0feh, swi 010000h" to get the normal settings.
NES Format
Emulates a NES (Nintendo Entertainment System) console (aka Family Computer).
The visible 240x224 pixel NES/NTSC screen resolution is resampled to 240x160 to match the smaller vertical resolution of the GBA hardware. So, writing e-Reader games in NES format will result in blurred screen output. The screen/sound/joypad is accessed via emulated NES I/O ports, program code is running on an emulated 6502 8bit CPU, for more info on the NES hardware, see no$nes debugger specifications, or

      http://problemkaputt.de/everynes.htm

The e-Reader's NES emulator supports only 16K PRG ROM, followed by 8K VROM. The emulation accuracy is very low, barely working with some of Nintendo's own NES titles; running the no$nes diagnostics program on it has successfully failed on ALL hardware tests ;-)
The load address for the 16K PRG-ROM is C000h, the 16bit NMI vector at [FFFAh] is encrypted like so:

      for i=17h to 0
       for j=07h to 0, nmi = nmi shr 1, if carry then nmi = nmi xor 8646h, next j
       nmi = nmi xor (byte[dmca_data+i] shl 8)
      next i
      dmca_data: db 0,0,'DMCA NINTENDO E-READER'

The 16bit reset vector at [FFFCh] contains:

      Bit0-14  Lower bits of Entrypoint (0..7FFFh = Address 8000h..FFFFh)
      Bit15    Nametable Mode (0=Vertical Mirroring, 1=Horizontal Mirroring)

reportedly,

       (NES limitations, 1 16K program rom + 1-2 8K CHR rom, mapper 0 and 1)
       ines mapper 1 would be MMC1, rather than CNROM (ines mapper 3)?
       but, there are more or less NONE games that have 16K PRG ROM + 16K VROM?

The L+R Button key-combination allows to reset the NES, however, there seems to be no way to return to the e-Reader BIOS.
Z80/8080 Format
The e-Reader doesn't support the following Z80 opcodes:

      CB [Prefix]     E0 RET PO   E2 JP PO,nn   E4 CALL PO,nn   27 DAA    76 HALT
      ED [Prefix]     E8 RET PE   EA JP PE,nn   EC CALL PE,nn   D3 OUT (n),A
      DD [IX Prefix]  F3 DI       08 EX AF,AF'  F4 CALL P,nn    DB IN A,(n)
      FD [IY Prefix]  FB EI       D9 EXX        FC CALL M,nn    xx RST 00h..38h

That is leaving not more than six supported Z80 opcodes (DJNZ, JR, JR c/nc/z/nz), everything else are 8080 opcodes. Custom opcodes are:

      76 WAIT A frames, D3 WAIT n frames, and C7/CF RST 0/8 used for API calls.

The load address and entrypoint are at 0100h in the emulated Z80 address space. The Z80 doesn't have direct access to the GBA hardware, instead video/sound/joypad are accessed via API functions, invoked via RST 0 and RST 8 opcodes, followed by an 8bit data byte, and with parameters in the Z80 CPU registers. For example, "ld a,02h, rst 8, db 00h" does return to the e-Reader BIOS.
The Z80/8080 emulation is incredibly inefficient, written in HLL code, developed by somebody whom knew nothing about emulation nor about ARM nor about Z80/8080 processors.
Running GBA-code on Japanese/Original e-Reader
Original e-Reader supports Z80 code only, but can be tweaked to run GBA-code:

      retry:
       ld bc,data // ld hl,00c8h      ;src/dst
      lop:
       ld a,[bc] // inc bc // ld e,a  ;lsb
       ld a,[bc] // inc bc // ld d,a  ;msb
       dw 0bcfh ;aka rst 8 // db 0bh  ;[4000000h+hl]=de (DMA registers)
       inc hl // inc  hl // ld a,l
       cp a,0dch // jr nz,lop
      mod1 equ $+1
       dw 37cfh ;aka rst 8 // db 37h  ;bx 3E700F0h
      ;below executed only on jap/plus... on jap/plus, above 37cfh is hl=[400010Ch]
       ld a,3Ah // ld [mod1],a                  ;bx 3E700F0h (3Ah instead 37h)
       ld hl,1 // ld [mod2],hl // ld [mod3],hl  ;base (0200010Ch instead 0201610Ch)
       jr retry
      data:
      mod2 equ $+1
       dd loader         ;40000C8h dma2sad (loader)            ;\
       dd 030000F0h      ;40000CCh dma2dad (mirrored 3E700F0h) ; relocate loader
       dd 8000000ah      ;40000D0h dma2cnt (copy 0Ah x 16bit)  ;/
      mod3 equ $+1
       dd main           ;40000D4h dma3sad (main)              ;\prepare main reloc
       dd 02000000h      ;40000D8h dma3dad (2000000h)          ;/dma3cnt see loader
       .align 2          ;alignment for 16bit-halfword
      org $+201600ch     ;jap/plus: adjusted to org $+200000ch
      loader:
       mov r0,80000000h  ;(dma3cnt, copy 10000h x 16bit)
       mov r1,04000000h  ;i/o base
       strb r1,[r1,208h] ;ime=0 (better disable ime before moving ram)
       str r0,[r1,0DCh]  ;dma3cnt (relocate to 2000000h)
       mov r15,2000000h  ;start relocated code at 2000000h in ARM state
      main:
       ;...insert/append whatever ARM code here...
       end

GBA Cart e-Reader API Functions

Z80 Interface (Special Opcodes)

      db 76h       ;Wait8bit A
      db D3h,xxh   ;Wait8bit xxh
      db C7h,xxh   ;RST0_xxh
      db CFh,xxh   ;RST8_xxh
      ld r,[00xxh]       ;get system values (addresses differ on jap/ori)
      ld r,[00C2h..C3h]  ;GetKeyStateSticky (jap/ori: 9F02h..9F03h)
      ld r,[00C4h..C5h]  ;GetKeyStateRaw    (jap/ori: 9F04h..9F05h)
      ld r,[00C0h..C1h]  ;see Exit and ExitRestart
      ld r,[00D0h..D3h]  ;see Mul16bit

For jap/ori, 9Fxxh isn't forwards compatible with jap/plus, so it'd be better to check joypad via IoRead.
GBA Interface

      bx [30075FCh] ;ApiVector ;in: r0=func_no,r1,r2,r3,[sp+0],[sp+4],[sp+8]=params
      bx lr         ;Exit      ;in: r0 (0=Restart, 2=To_Menu)

Wait8bit/Wait16bit
The various Wait opcodes and functions are waiting as many frames as specified. Many API functions have no effect until the next Wait occurs.
Z80 RST0_xxh Functions / GBA Functions 02xxh

      RST0_00h FadeIn, A speed, number of frames (0..x)
      RST0_01h FadeOut
      RST0_02h BlinkWhite
      RST0_03h  (?)
      RST0_04h  (?) blend_func_unk1
      RST0_05h  (?)
      RST0_06h  (?)
      RST0_07h  (?)
      RST0_08h  (?)
      RST0_09h  (?) _020264CC_check
      RST0_0Ah  (?) _020264CC_free
      RST0_0Bh N/A (bx 0)
      RST0_0Ch N/A (bx 0)
      RST0_0Dh N/A (bx 0)
      RST0_0Eh N/A (bx 0)
      RST0_0Fh N/A (bx 0)
      RST0_10h LoadSystemBackground, A number of background (1..101), E bg# (0..3)
      RST0_11h SetBackgroundOffset, A=bg# (0..3), DE=X, BC=Y
      RST0_12h SetBackgroundAutoScroll
      RST0_13h SetBackgroundMirrorToggle
      RST0_14h  (?)
      RST0_15h  (?)
      RST0_16h  (?) write_000000FF_to_02029494_
      RST0_17h  (?)
      RST0_18h  (?)
      RST0_19h SetBackgroundMode, A=mode (0..2)
      RST0_1Ah  (?)
      RST0_1Bh  (?)
      RST0_1Ch  (?)
      RST0_1Dh  (?)
      RST0_1Eh  (?)
      RST0_1Fh  (?)
      RST0_20h LayerShow
      RST0_21h LayerHide
      RST0_22h  (?)
      RST0_23h  (?)
      RST0_24h ... [20264DCh+A*20h+1Ah]=DE, [20264DCh+A*20h+1Ch]=BC
      RST0_25h  (?)
      RST0_26h  (?)
      RST0_27h  (?)
      RST0_28h  (?)
      RST0_29h  (?)
      RST0_2Ah  (?)
      RST0_2Bh  (?)
      RST0_2Ch  (?)
      RST0_2Dh LoadCustomBackground, A bg# (0..3), DE pointer to struct_background,
               max. tile data size = 3000h bytes, max. map data size = 1000h bytes
      RST0_2Eh GBA: N/A - Z80: (?)
      RST0_2Fh  (?)
      RST0_30h CreateSystemSprite, - -   (what "- -" ???)
      RST0_31h SpriteFree, HL sprite handle
      RST0_32h SetSpritePos, HL=sprite handle, DE=X, BC=Y
      RST0_33h  (?) sprite_unk2
      RST0_34h SpriteFrameNext
      RST0_35h SpriteFramePrev
      RST0_36h SetSpriteFrame, HL=sprite handle, E=frame number (0..x)
      RST0_37h  (?) sprite_unk3
      RST0_38h  (?) sprite_unk4
      RST0_39h SetSpriteAutoMove, HL=sprite handle, DE=X, BC=Y
      RST0_3Ah  (?) sprite_unk5
      RST0_3Bh  (?) sprite_unk6
      RST0_3Ch SpriteAutoAnimate
      RST0_3Dh  (?) sprite_unk7
      RST0_3Eh SpriteAutoRotateUntilAngle
      RST0_3Fh SpriteAutoRotateByAngle
      RST0_40h SpriteAutoRotateByTime
      RST0_41h  (?) sprite_unk8
      RST0_42h SetSpriteAutoMoveHorizontal
      RST0_43h SetSpriteAutoMoveVertical
      RST0_44h  (?) sprite_unk9
      RST0_45h SpriteDrawOnBackground
      RST0_46h SpriteShow, HL=sprite handle
      RST0_47h SpriteHide, HL=sprite handle
      RST0_48h SpriteMirrorToggle
      RST0_49h  (?) sprite_unk10
      RST0_4Ah  (?) sprite_unk11
      RST0_4Bh  (?) sprite_unk12
      RST0_4Ch GetSpritePos
      RST0_4Dh CreateCustomSprite
      RST0_4Eh  (?)
      RST0_4Fh  (?) sprite_unk14
      RST0_50h  (?) sprite_unk15
      RST0_51h  (?) sprite_unk16
      RST0_52h  (?) sprite_unk17
      RST0_53h  (?) sprite_unk18
      RST0_54h  (?)
      RST0_55h  (?) sprite_unk20
      RST0_56h  (?)
      RST0_57h SpriteMove
      RST0_58h  (?) sprite_unk22
      RST0_59h  (?) sprite_unk23
      RST0_5Ah  (?) sprite_unk24
      RST0_5Bh SpriteAutoScaleUntilSize, C=speed (higher value is slower),
               HL=sprite handle, DE=size (0100h = normal size,
               lower value = larger, higher value = smaller)
      RST0_5Ch SpriteAutoScaleBySize
      RST0_5Dh SpriteAutoScaleWidthUntilSize
      RST0_5Eh SpriteAutoScaleHeightBySize
      RST0_5Fh  (?)
      RST0_60h  (?)
      RST0_61h  (?)
      RST0_62h  (?)
      RST0_63h  (?)
      RST0_64h hl=[[2024D28h+a*4]+12h]
      RST0_65h  (?) sprite_unk25
      RST0_66h SetSpriteVisible, HL=sprite handle, E=(0=not visible, 1=visible)
      RST0_67h  (?) sprite_unk26
      RST0_68h  (?) set_sprite_unk27
      RST0_69h  (?) get_sprite_unk27
      RST0_6Ah  (?)
      RST0_6Bh  (?)
      RST0_6Ch  (?)
      RST0_6Dh  (?)
      RST0_6Eh hl=[hl+000Ah]  ;r0=[r1+0Ah]
      RST0_6Fh  (?)
      RST0_70h  (?)
      RST0_71h  (?)
      RST0_72h  (?)
      RST0_73h  (?)
      RST0_74h  (?)
      RST0_75h  (?)
      RST0_76h  (?)
      RST0_77h  (?)
      RST0_78h  (?)
      RST0_79h  (?)
      RST0_7Ah  (?)
      RST0_7Bh  (?)
      RST0_7Ch  (?) _0202FD2C_unk12
      RST0_7Dh Wait16bit ;HL=num_frames (16bit variant of Wait8bit opcode/function)
      RST0_7Eh SetBackgroundPalette, HL=src_addr, DE=offset, C=num_colors (1..x)
      RST0_7Fh GetBackgroundPalette(a,b,c)
      RST0_80h SetSpritePalette, HL=src_addr, DE=offset, C=num_colors (1..x)
      RST0_81h GetSpritePalette(a,b,c)
      RST0_82h ClearPalette
      RST0_83h  (?) _0202FD2C_unk11
      RST0_84h  (?)
      RST0_85h  (?)
      RST0_86h  (?)
      RST0_87h  (?) _0202FD2C_unk8
      RST0_88h  (?) _0202FD2C_unk7
      RST0_89h  (?)
      RST0_8Ah  (?) _0202FD2C_unk6
      RST0_8Bh  (?) _0202FD2C_unk5
      RST0_8Ch GBA: N/A - Z80: (?)
      RST0_8Dh GBA: N/A - Z80: (?)
      RST0_8Eh  (?)
      RST0_8Fh WindowHide
      RST0_90h CreateRegion, H=bg# (0..3), L=palbank# (0..15),
               D,E,B,C=x1,y1,cx,cy (in tiles), return: n/a (no$note: n/a ???)
      RST0_91h SetRegionColor
      RST0_92h ClearRegion
      RST0_93h SetPixel
      RST0_94h GetPixel
      RST0_95h DrawLine
      RST0_96h DrawRect
      RST0_97h  (?) _0202FD2C_unk4
      RST0_98h SetTextColor, A=region handle, D=color foreground (0..15),
               E=color background (0..15)
      RST0_99h DrawText, A=region handle, BC=pointer to text, D=X, E=Y
               (non-japan uses ASCII text, but japanese e-reader's use STH ELSE?)
      RST0_9Ah SetTextSize
      RST0_9Bh  (?) RegionUnk7
      RST0_9Ch  (?) _0202FD2C_unk3
      RST0_9Dh  (?) _0202FD2C_unk2
      RST0_9Eh  (?) _0202FD2C_unk1
      RST0_9Fh Z80: (?) - GBA: SetBackgroundModeRaw
      RST0_A0h  (?)
      RST0_A1h  (?)
      RST0_A2h  (?) RegionUnk6
      RST0_A3h GBA: N/A - Z80: (?)
      RST0_A4h GBA: N/A - Z80: (?)
      RST0_A5h  (?)
      RST0_A6h  (?)
      RST0_A7h  (?)
      RST0_A8h  (?)
      RST0_A9h  (?)
      RST0_AAh  (?)
      RST0_ABh  (?)
      RST0_ACh  (?)
      RST0_ADh  (?) RegionUnk5
      RST0_AEh [202FD2Ch+122h]=A
      RST0_AFh [202FD2Ch+123h]=A
      RST0_B0h [202FD2Ch+124h]=A
      RST0_B1h  (?)
      RST0_B2h  (?)
      RST0_B3h GBA: N/A - Z80: Sqrt   ;hl=sqrt(hl)
      RST0_B4h GBA: N/A - Z80: ArcTan ;hl=ArcTan2(hl,de)
      RST0_B5h Sine                   ;hl=sin(a)*de
      RST0_B6h Cosine                 ;hl=cos(a)*de
      RST0_B7h  (?)
      RST0_B8h  (?)
      RST0_B9h N/A (bx 0)
      RST0_BAh N/A (bx 0)
      RST0_BBh N/A (bx 0)
      RST0_BCh N/A (bx 0)
      RST0_BDh N/A (bx 0)
      RST0_BEh N/A (bx 0)
      RST0_BFh N/A (bx 0)
      Below Non-Japan and Japan/Plus only (not Japan/Ori)
      RST0_C0h GetTextWidth(a,b)
      RST0_C1h GetTextWidthEx(a,b,c)
      RST0_C2h  (?)
      RST0_C3h Z80: N/A (bx 0) - GBA: (?)
      RST0_C4h  (?)
      RST0_C5h  (?)
      RST0_C6h  (?)
      RST0_C7h  (?)
      RST0_C8h  (?)
      RST0_C9h  (?)
      RST0_CAh  (?)
      RST0_CBh  (?)
      RST0_CCh  (?)
      RST0_CDh N/A (bx lr)
      RST0_CEh ;same as RST0_3Bh, but with 16bit mask
      RST0_CFh ;same as RST0_3Eh, but with 16bit de
      RST0_D0h ;same as RST0_3Fh, but with 16bit de
      RST0_D1h ;same as RST0_5Bh, but with 16bit de
      RST0_D2h ;same as RST0_5Ch, but with 16bit de
      RST0_D3h ;same as RST0_5Dh, but with 16bit de
      RST0_D4h ;same as RST0_5Eh, but with 16bit de
      RST0_D5h  (?)
      RST0_D6h  (?)
      RST0_D7h ;[202FD2Ch+125h]=A
      RST0_D8h  (?)
      RST0_D9h  (?)
      RST0_DAh  (?)
      RST0_DBh ;A=[3003E51h]
      RST0_DCh ;[3004658h]=01h
      RST0_DDh DecompressVPKorNonVPK
      RST0_DEh FlashWriteSectorSingle(a,b)
      RST0_DFh FlashReadSectorSingle(a,b)
      RST0_E0h SoftReset
      RST0_E1h GetCartridgeHeader     ;[hl+0..BFh]=[8000000h..80000BFh]
      RST0_E2h GBA: N/A - Z80: bx hl  ;in: hl=addr, af,bc,de,sp=param, out: a
      RST0_E3h Z80: N/A (bx 0) - GBA: (?)
      RST0_E4h  (?)
      RST0_E5h  (?)
      RST0_E6h  (?)
      RST0_E7h  (?)
      RST0_E8h  (?)
      RST0_E9h ;[2029498h]=0000h
      RST0_EAh Z80: N/A (bx 0) - GBA: InitMemory(a)
      RST0_EBh  (?) BL_irq_sio_dma3
      RST0_ECh ;hl = [3003E30h]*100h + [3003E34h]
      RST0_EDh FlashWriteSectorMulti(a,b,c)
      RST0_EEh FlashReadPart(a,b,c)
      RST0_EFh ;A=((-([2029416h] xor 1)) OR (+([2029416h] xor 1))) SHR 31
      RST0_F0h  (?) _unk1
      RST0_F1h RandomInit     ;in: hl=random_seed
      RST0_F2h                         (?)
      Below Japan/Plus only
      RST0_F3h  (?)
      RST0_F4h  (?)
      RST0_F5h  (?)
      RST0_F6h  (?)
      RST0_F7h GBA: N/A - Z80: (?)
      Below is undefined/garbage (values as so in Z80 mode)
      Jap/Ori: RST0_C0h      N/A (bx 0)
      Jap/Ori: RST0_C1h..FFh Overlaps RST8 jump list
      Non-Jap: RST0_F3h..FFh Overlaps RST8 jump list
      Jap/Pls: RST0_F8h..FFh Overlaps RST8 jump list

Z80 RST8_xxh Functions / GBA Functions 01xxh

      RST8_00h GBA: N/A - Z80: Exit       ;[00C0h]=a ;(1=restart, 2=exit)
      RST8_01h GBA: N/A - Z80: Mul8bit    ;hl=a*e
      RST8_02h GBA: N/A - Z80: Mul16bit   ;hl=hl*de, s32[00D0h]=hl*de
      RST8_03h Div                        ;hl=hl/de
      RST8_04h DivRem                     ;hl=hl mod de
      RST8_05h PlaySystemSound            ;in: hl=sound_number
      RST8_06h  (?) sound_unk1
      RST8_07h Random8bit                 ;a=random(0..FFh)
      RST8_08h SetSoundVolume
      RST8_09h BcdTime                    ;[de+0..5]=hhmmss(hl*bc)
      RST8_0Ah BcdNumber                  ;[de+0..4]=BCD(hl), [de+5]=00h
      RST8_0Bh IoWrite                    ;[4000000h+hl]=de
      RST8_0Ch IoRead                     ;de=[4000000h+hl]
      RST8_0Dh GBA: N/A - Z80:  (?)
      RST8_0Eh GBA: N/A - Z80:  (?)
      RST8_0Fh GBA: N/A - Z80:  (?)
      RST8_10h GBA: N/A - Z80:  (?)
      RST8_11h DivSigned                  ;hl=hl/de, signed
      RST8_12h RandomMax                  ;a=random(0..a-1)
      RST8_13h SetSoundSpeed
      RST8_14h  hl=[202FD20h]=[2024CACh]
      RST8_15h  hl=[2024CACh]-[202FD20h]
      RST8_16h SoundPause
      RST8_17h SoundResume
      RST8_18h PlaySystemSoundEx
      RST8_19h IsSoundPlaying
      RST8_1Ah  (?)
      RST8_1Bh  (?)
      RST8_1Ch  (?)
      RST8_1Dh GetExitCount               ;a=[2032D34h]
      RST8_1Eh Permille                   ;hl=de*1000/hl
      RST8_1Fh GBA: N/A - Z80: ExitRestart;[2032D38h]=a, [00C0h]=0001h  ;a=?
      RST8_20h GBA: N/A - Z80: WaitJoypad ;wait until joypad<>0, set hl=joypad
      RST8_21h GBA: N/A - Z80:  (?)
      RST8_22h  (?) _sound_unk7
      RST8_23h  (?) _sound_unk8
      RST8_24h  (?) _sound_unk9
      RST8_25h  (?) _sound_unk10
      RST8_26h Mosaic     ;bg<n>cnt.bit6=a.bit<n>, [400004Ch]=de
      RST8_27h  (?)
      RST8_28h  (?)
      RST8_29h  (?)
      RST8_2Ah  (?) get_8bit_from_2030110h
      RST8_2Bh  (?)
      RST8_2Ch  (?) get_16bit_from_2030112h ;jap/ori: hl=[20077B2h]
      RST8_2Dh  (?) get_16bit_from_2030114h ;jap/ori: hl=[20077B4h]
      RST8_2Eh  (?)
      RST8_2Fh PlayCustomSound(a,b)
      Below not for Japanese/Original
      (the renumbered functions can be theoretically used on japanese/original)
      (but, doing so would blow forwards compatibility with japanese/plus)
      RST8_30h (ori: none)      GBA: N/A - Z80: (?)
      RST8_31h (ori: none)      PlayCustomSoundEx(a,b,c)
      RST8_32h (ori: RST8_30h)  BrightnessHalf   ;[4000050h]=00FFh,[4000054h]=0008h
      RST8_33h (ori: RST8_31h)  BrightnessNormal ;[4000050h]=0000h
      RST8_34h (ori: RST8_32h)  N/A (bx lr)
      RST8_35h (ori: RST8_33h)   (?)
      RST8_36h (ori: RST8_34h)  ResetTimer ;[400010Ch]=00000000h, [400010Eh]=A+80h
      RST8_37h (ori: RST8_35h)  GetTimer   ;hl=[400010Ch]
      RST8_38h (ori: none)      GBA: N/A - Z80:  (?)
      Below is undefined/reserved/garbage (values as so in Z80 mode)
      (can be used to tweak jap/ori to start GBA-code from inside of Z80-code)
      (that, after relocating code to 3000xxxh via DMA via IoWrite function)
      RST8_39h (ori: RST8_36h)  bx 0140014h
      RST8_3Ah (ori: RST8_37h)  bx 3E700F0h
      RST8_3Bh (ori: RST8_38h)  bx 3E70000h+1
      RST8_3Ch (ori: RST8_39h)  bx 3E703E6h+1
      RST8_3Dh (ori: RST8_3Ah)  bx 3E703E6h+1
      RST8_3Eh (ori: RST8_3Bh)  bx 3E703E6h+1
      RST8_3Fh (ori: RST8_3Ch)  bx 3E703E6h+1
      40h-FFh  (ori: 3Dh-FFh)   bx ...

GBA Functions 03xxh (none such in Z80 mode)

      RSTX_00h Wait8bit  ;for 16bit: RST0_7Dh
      RSTX_01h GetKeyStateSticky()
      RSTX_02h GetKeyStateRaw()
      RSTX_03h  (?)
      RSTX_04h  (?)

GBA Cart e-Reader VPK Decompression

vpk_decompress(src,dest)

      collected32bit=80000000h  ;initially empty (endflag in bit31)
      for i=0 to 3, id[i]=read_bits(8), next i, if id[0..3]<>'vpk0' then error
      dest_end=dest+read_bits(32)     ;size of decompressed data (of all strips)
      method=read_bits(8), if method>1 then error
      tree_index=0, load_huffman_tree, disproot=tree_index
      tree_index=tree_index+1, load_huffman_tree, lenroot=tree_index
      ;above stuff is contained only in the first strip. below loop starts at
      ;current location in first strip, and does then continue in further strips.
     decompress_loop:
      if read_bits(1)=0 then                   ;copy one uncompressed data byte,
        [dest]=read_bits(8), dest=dest+1       ;does work without huffman trees
      else
        if disproot=-1 or lenroot=-1 then error  ;compression does require trees
        disp=read_tree(disproot)
        if method=1   ;disp*4 is good for 32bit ARM opcodes
          if disp>2 then disp=disp*4-8 else disp=disp+4*read_tree(disproot)-7
        len=read_tree(lenroot)
        if len=0 or disp<=0 or dest+len-1>dest_end then error ;whoops
        for j=1 to len, [dest]=[dest-disp], dest=dest+1, next j
      if dest<dest_end then decompress_loop
      ret

read_bits(num)

      mov  data=0
      for i=1 to num
        shl collected32bit,1   ;move next bit to carry, or set zeroflag if empty
        if zeroflag
          collected32bit=[src+0]*1000000h+[src+1]*10000h+[src+2]*100h+[src+3]
          src=src+4            ;read data in 32bit units, in reversed byte-order
          carryflag=1          ;endbit
          rcl collected32bit,1 ;move bit31 to carry (and endbit to bit0)
        rcl data,1             ;move carry to data
      next i
      ret(data)

read_tree(root_index)

      i=root_index
      while node[i].right<>-1  ;loop until reaching data node
        if read_bits(1)=1 then i=node[i].right else i=node[i].left
      i=node[i].left           ;get number of bits
      i=read_bits(i)           ;read that number of bits
      ret(i)                   ;return that value

load_huffman_tree

      stacktop=sp
      if read_bits(1)=1 then tree_index=-1, ret  ;exit (empty)
      node[tree_index].right=-1                  ;indicate data node
      node[tree_index].left=read_bits(8)         ;store data value
      if read_bits(1)=1 then ret                 ;exit (only 1 data node at root)
      push tree_index                     ;save previous (child) node
      tree_index=tree_index+1
      jmp data_injump
     load_loop:
      push tree_index                     ;save previous (child) node
      tree_index=tree_index+1
      if read_bits(1)=1 then parent_node
     data_injump:
      node[tree_index].right=-1           ;indicate data node
      node[tree_index].left=read_bits(8)  ;store data value
      jmp load_loop
     parent_node:
      pop node[tree_index].right          ;store 1st child
      pop node[tree_index].left           ;store 2nd child
      if sp<>stacktop then jmp load_loop
      if read_bits(1)=0 then error        ;end bit (must be 1)
      ret

The best values for the huffman trees that I've found are 6,9,12-bit displacements for method 0 (best for NES/Z80 code), and two less for method 1, ie. 4,7,10-bit (best for GBA code). And 2,4,10-bit for the length values. The smallest value in node 0, and the other values in node 10 and 11.
Notes
The decompression works similar to the GBA BIOS'es LZ77 decompression function, but without using fixed bit-widths of length=4bit and displacement=12bit, instead, the bit-widths are read from huffman trees (which can also define fixed bit-widths; if data is located directly in the root node).
Unlike the GBA BIOS'es Huffman decompression function, the trees are starting with data entries, end are ending with the root entry. The above load function deciphers the data, and returns the root index.
With the variable bit-widths, the VPK compression rate is quite good, only, it's a pity that the length/disp values are zero-based, eg. for 2bit and 4bit lengths, it'd be much better to assign 2bit as 2..5, and 4bit as 6..21.
Non-VPK
The e-Reader additionally supports an alternate decompression function, indicated by the absence of the "vpk0" ID, which supports compression of increasing byte-values, which isn't useful for program code.
Bit15 of the VPK Size value seems to disable (de-)compression, the VPK Data field is then containing plain uncompressed data.

GBA Cart e-Reader Error Correction

The Error Correction Information that is appended at the end of the Block Header & Data Fragments consists of standard Reed-Solomon codes, which are also used for CD/DVD disks, DSL modems, and digital DVB television signals. That info allows to locate and repair a number of invalid data bytes.
Below code shows how to create and verify error-info (but not how to do the actual error correction). The dtalen,errlen values should be 18h,10h for the Block Header, and 40h,10h for Data Fragments; the latter settings might be possible to get changed to other values though?
append_error_info(data,dtalen,errlen)

      reverse_byte_order(data,dtalen)
      zerofill_error_bytes(data,errlen)
      for i=dtalen-1 to errlen  ;loop across data portion
        z = rev[ data[i] xor data[errlen-1] ] ;
        for j=errlen-1 to 0     ;loop across error-info portion
        if j=0 then x=00h else x=data[j-1]
          if z<>FFh then
            y=gg[j], if y<>FFh then
              y=y+z, if y>=FFh then y=y-FFh
              x=x xor pow[y]
          data[j]=x
        next j
      next i
      invert_error_bytes(data,errlen)
      reverse_byte_order(data,dtalen)

verify_error_info(data,dtalen,errlen)

      reverse_byte_order(data,dtalen)
      invert_error_bytes(data,errlen)
      make_rev(data,dtalen)
      for i=78h to 78h+errlen-1
        x=0, z=0
        for j=0 to dtalen-1
          y=data[j]
          if y<>FFh then
            y=y+z, if y>=FFh then y=y-FFh
            x=x xor pow[y]
          z=z+i, if z>=FFh then z=z-FFh
        next j
        if x<>0 then error
      next i
      ;(if errors occured, could correct them now)
      make_pow(data,dtalen)
      invert_error_bytes(data,errlen)
      reverse_byte_order(data,dtalen)

make_rev(data,len)

      for i=0 to len-1, data[i]=rev[data[i]], next i

make_pow(data,len)

      for i=0 to len-1, data[i]=pow[data[i]], next i

invert_error_bytes(data,len)

      for i=0 to len-1, data[i]=data[i] xor FFh, next i

zerofill_error_bytes(data,len)

      for i=0 to len-1, data[i]=00h, next i

reverse_byte_order(data,len)

      for i=0 to (len-1)/2, x=data[i], data[i]=data[len-i], data[len-i]=x, next i

create_pow_and_rev_tables

      x=01h, pow[FFh]=00h, rev[00h]=FFh
      for i=00h to FEh
        pow[i]=x, rev[x]=i, x=x*2, if x>=100h then x=x xor 187h
      next i

create_gg_table

      gg[0]=pow[78h]
      for i=1 to errlen-1
        gg[i]=01h
        for j=i downto 0
          if j=0 then y=00h else y=gg[j-1]
          x=gg[j], if x<>00h then
            x=rev[x]+78h+i, if x>=FFh then x=x-FFh
            y=y xor pow[x]
          gg[j]=y
        next j
      next i
      make_rev(gg,errlen)

With above value of 78h, and errlen=10h, gg[00h..0Fh] will be always:

      00h,4Bh,EBh,D5h,EFh,4Ch,71h,00h,F4h,00h,71h,4Ch,EFh,D5h,EBh,4Bh

So using a hardcoded table should take up less memory than calculating it.
Notes
The actual error correction should be able to fix up to "errlen" errors at known locations (eg. data from blocks that haven't been scanned, or whose 5bit-to-4bit conversion had failed due to an invalid 5bit value), or up to "errlen/2" errors at unknown locations. The corrected data isn't guaranteed to be correct (even if it looks okay to the "verify" function), so the Data Header checksums should be checked, too.
More Info
For more info, I've found Reed-Solomon source code from Simon Rockliff, and an updated version from Robert Morelos-Zaragoza and Hari Thirumoorthy to be useful. For getting started with that source, some important relationships & differences are:

      pow = alpha_to, but generated as shown above
      rev = index_of, dito
      b0  = 78h
      nn  = dtalen
      kk  = dtalen-errlen
      %nn = MOD FFh (for the ereader that isn't MOD dtalen)
      -1  = FFh

And, the ereader processes data/errinfo backwards, starting at the last byte.

GBA Cart e-Reader File Formats

.BMP Files (homebrew 300 DPI strips)
Contains a picture of the whole dotcode strip with address bars and sync marks (see Dotcode chapter) in Microsoft's Bitmap format. The image is conventionally surrounded by a blank 2-pixel border, resulting in a size of 989x44 pixels for long strips. The file should should have 1bit color depth. The pixels per meter entry should match the desired printing resolution, either 300 DPI or 360 DPI. But, resolution of printer hardware is typically specified in inch rather than in meters, so an exact match isn't supported by Microsoft. Most homebrew .BMP files contain nonsense resolutions like 200 DPI, or 300 dots per meter (ca. 8 DPI).
.JPG Files (scanned 1200 DPI strips)
Same as BMP, but should contain a dotcode scanned at 1200 DPI, with correct orientation (the card-edge side at the bottom of the image), and containing only the dotcode (not the whole card), so the JPG size should be about 3450x155 pixels for long strips.
No$gba currently doesn't work with progressive JPGs. Scans with white background can be saved as monochrome JPG. Scans with red/yellow background should contain a correct RED layer (due to the red LED light source) (the brightness of the green/blue layers can be set to zero for better compression).
.RAW Files
Contains the "raw" information from the BMP format, that is, 2-byte block header, 102-byte data, 2-byte block header, 102-byte data, etc. The data portion is interleaved, and includes the full 48-byte data header, titles, vpk compressed data, error-info, and unused bytes. RAW files are excluding Address Bars, Sync Marks, and 4bit-to-5bit encoding.
Each RAW file contains one or more strip(s), so the RAW filesize is either 18*104 bytes (short strip), or 28*104 bytes (long strip), or a multiple thereof (if it contains more than one strip) (although multi-strip games are often stored in separate files for each strip; named file1.raw, file2.raw, etc).
.BIN Files
Filesize should be I*30h, with I=1Ch for short strips, and I=2Ch for long strips, or a multiple thereof (if it contains more than one strip). Each strip consists of the 48-byte Data Header, followed by title(s), and vpk compressed data. Unlike .RAW files, .BIN files aren't interleaved, and do not contain Block Headers, nor error-info, nor unused bytes (in last block). The files do contain padding bytes to match a full strip-size of I*30h.
Caution: Older .BIN files have been using a size-reduced 12-byte header (taken from entries 0Dh, 0Ch, 10h-11h, 26h-2Dh of the 48-byte Data Header; in that order), that files have never contained more than one strip per file, so the filesize should be exactly I*30h-36, the size-reduced header doesn't contain a Primary Type entry, so it's everyone's bet which Card Type is to be used (hint: the 12-byte headers were based on the assumption that Primary Type would be always 01h on Short Strips, and 02h on Long Strips).
.SAV Files
Contains a copy of the e-Reader's 128Kbyte FLASH memory. With the saved e-Reader application being located in the 2nd 64K-bank, the data consists of a header with title and gba/nes/z80 format info, followed by the vpk compressed data. The FLASH memory does also contain e-Reader calibration settings, the remaining 100Kbytes are typically FFh-filled.

GBA Cart Unknown Devices

GBA Infra-Red Port (AGB-006)
No info?

GBA Cart Protections

Classic NES Series
These are some NES/Famicom games ported or emulated to work on GBA. The games are doing some uncommon stuff that can cause compatibility problems when not using original GBA consoles or cartridges.
- CPU pipeline (selfmodifying code that shall NOT affect prefetched opcodes)
- STMDA write to I/O ports (writes in INCREASING order, not DECREASING order)
- SRAM detection (refuses to run if SRAM exists; the games do contain EEPROM)
- ROM mirrors (instead of the usual increasing numbers in unused ROM area)
- RAM mirrors (eg. main RAM accessed at 2F00000h instead of 2000000h)
Note: These games can be detected by checking [80000ACh]="F" (ie. game code="Fxxx").

GBA Flashcards

Flashcards are re-writable cartridges using FLASH memory, allowing to test even multiboot-incompatible GBA software on real hardware, providing a good development environment when used in combination with a reasonable software debugger.
The carts can be written to from external tools, or directly from GBA programs.
Below are pseudo code flowcharts for detect, erase, and write operations.
All flash reads/writes are meant to be 16bit (ldrh/strh) memory accesses.
detect_flashcard:

     configure_flashcard(9E2468Ah,9413h)    ;unlock flash advance cards
     turbo=1, send_command(8000000h,90h)    ;enter ID mode (both chips, if any)
     maker=[8000000h], device=[8000000h+2]
     IF maker=device THEN device=[8000000h+4] ELSE turbo=0
     flashcard_read_mode                    ;exit ID mode
     search (maker+device*10000h) in device_list
     total/erase/write_block_size = list_entry SHL turbo

flashcard_erase(dest,len):

     FOR x=1 to len/erase_block_size
      send_command(dest,20h)        ;erase sector command
      send_command(dest,D0h)        ;confirm erase sector
      dest=dest+erase_block_size
     IF wait_busy=okay THEN NEXT x
     enter_read_mode                ;exit erase/status mode

flashcard_write(src,dest,len):

     siz=write_block_size
     FOR x=1 to len/siz
      IF siz=2 THEN send_command(dest,10h)  ;write halfword command
      IF siz>2 THEN send_command(dest,E8h)  ;write to buffer command
      IF siz>2 THEN send_command(dest,16-1) ;buffer size 16 halfwords (per chip)
      FOR y=1 TO siz/2
       [dest]=[src], dest=dest+2, src=src+2 ;write data to buffer
      NEXT y
      IF siz>2 THEN send_command(dest,D0h)  ;confirm write to buffer
     IF wait_busy=okay THEN NEXT x
     enter_read_mode                        ;exit write/status mode

send_command(adr,val):

     [adr]=val
     IF turbo THEN [adr+2]=val

enter_read_mode:

     send_command(8000000h,FFh)     ;exit status mode
     send_command(8000000h,FFh)     ;again maybe more stable (as in jeff's source)

flashcard_wait_busy:

     start=time
     REPEAT
      stat=[8000000h] XOR 80h
      IF turbo THEN stat=stat OR ([8000000h+2] XOR 80h)
      IF (stat AND 7Fh)>0 THEN error
      IF (stat AND 80h)=0 THEN ready
      IF time-start>5secs THEN timeout
     UNTIL ready OR error OR timeout
     IF error OR timeout THEN send_command(8000000h,50h)    ;clear status

configure_flashcard(adr,val): ;required for Flash Advance cards only

     [930ECA8h]=5354h
     [802468Ah]=1234h, repeated 500 times
     [800ECA8h]=5354h
     [802468Ah]=5354h
     [802468Ah]=5678h, repeated 500 times
     [930ECA8h]=5354h
     [802468Ah]=5354h
     [8ECA800h]=5678h
     [80268A0h]=1234h
     [802468Ah]=ABCDh, repeated 500 times
     [930ECA8h]=5354h
     [adr]=val

init_backup: ;no info how to use that exactly

     configure_flashcard(942468Ah,???)

device_list: (id code, total/erase/write sizes in bytes)

      ID Code    Total   Erase  Write  Name
      -??-00DCh      ?       ?      ?  Hudson Cart (???)
      00160089h     4M    128K     32  Intel i28F320J3A (Flash Advance)
      00170089h     8M    128K     32  Intel i28F640J3A (Flash Advance)
      00180089h    16M    128K     32  Intel i28F128J3A (Flash Advance)
      00E200B0h      ?     64K      2  Sharp LH28F320BJE ? (Nintendo)

Notes
All flashcards should work at 4,2 waitstates (power on default), most commercial games change waits to 3,1 which may work unstable with some/older FA flashcards. Intel FLASH specified to have a lifetime of 100,000 erases, and average block erase time 1 second (up to 5 second in worst cases).
Aside from the main FLASH memory, Flash Advance (FA) (aka Visoly) cards additionally contain battery buffered SRAM backup, and FLASH backup, and in some cases also EEPROM backup.
Turbo FA cards are containing two chips interlaced (at odd/even halfword addresses), allowing to write/erase both chips simultaneously, resulting in twice as fast programming time.
Standard Nintendo flash carts have to be modified before you can actually write to them. This is done by removing resistor R7 and putting it at empty location R8.
Mind that write/erase/detect modes output status information in ROM area, so that in that modes all GBA program code (and any interrupt handlers) must be executed in WRAM, not in ROM.
Thanks to Jeff Frohwein for his FAQ and CARTLIB sample in FLGBA at devrs.com

GBA Cheat Devices

Codebreaker (US) aka Xploder (EUR).
Gameshark (US) aka Action Replay (EUR).
GBA Cheat Codes - General Info
GBA Cheat Codes - Codebreaker/Xploder
GBA Cheat Codes - Gameshark/Action Replay V1/V2
GBA Cheat Codes - Pro Action Replay V3

GBA Cheat Codes - General Info

Cheat devices are external adapters, connected between the GBA and the game cartridge. The devices include a BIOS ROM which is, among others, used to prompt the user to enter cheat codes.
These codes are used to patch specified memory locations for a certain GBA game, allowing the user to gain goodies such like Infinite sex, 255 Cigarettes, etc.
ROM and RAM Patches
For ROM Patches, the device watches the address bus, if it matches a specified address then it outputs a patched value to the data bus, that mechanism is implemented by hardware, aside from the Hook Enable Code some devices also allow a limited number of cheats to use ROM patches.
Most cheat codes are RAM patches, each time when the hook procedure is executed it will process all codes and overwrite the specified addresses in RAM (or VRAM or I/O area) by the desired values.
Enable Codes (Must Be On)
Enable codes usually consist of the Game ID, Hook Address, and eventually a third code used to encrypt all following codes. The Game ID is used to confirm that the correct cartridge is inserted, just a verification, though the device may insist on the ID code.
The Hook Address specifies an address in cartridge ROM, and should point to an opcode which is executed several times per second (eg. once per frame, many codes place the hook in the joypad handler). At the hook address, the device redirects to its own BIOS, processes the RAM patches, and does then return control to the game cartridge.
Note: The hook address should not point to opcodes with relative addressing (eg. B, BL, LDR Rd,=Imm, ADD Rd,=Imm opcodes - which are all relative to PC program counter register).
Alignment
Addresses for 16bit or 32bit values should be properly aligned.

GBA Cheat Codes - Codebreaker/Xploder

Codebreaker Codes

      0000xxxx 000y  Enable Code 1 - Game ID
      1aaaaaaa 000z  Enable Code 2 - Hook Address
      2aaaaaaa yyyy  [aaaaaaa]=[aaaaaaa] OR yyyy
      3aaaaaaa 00yy  [aaaaaaa]=yy
      4aaaaaaa yyyy  [aaaaaaa+0..(cccc-1)*ssss]=yyyy+0..(cccc-1)*ssss
      iiiicccc ssss  parameters for above code
      5aaaaaaa cccc  [aaaaaaa+0..(cccc-1)]=11,22,33,44,etc.
      11223344 5566  parameter bytes 1..6 for above code (example)
      77880000 0000  parameter bytes 7..8 for above code (padded with zero)
      6aaaaaaa yyyy  [aaaaaaa]=[aaaaaaa] AND yyyy
      7aaaaaaa yyyy  IF [aaaaaaa]=yyyy THEN (next code)
      8aaaaaaa yyyy  [aaaaaaa]=yyyy
      9xyyxxxx xxxx  Enable Code 0 - Encrypt all following codes (optional)
      Aaaaaaaa yyyy  IF [aaaaaaa]<>yyyy THEN (next code)
      Baaaaaaa yyyy  IF [aaaaaaa]>yyyy THEN (next code) (signed comparison)
      Caaaaaaa yyyy  IF [aaaaaaa]<yyyy THEN (next code) (signed comparison)
      D0000020 yyyy  IF [joypad] AND yyyy = 0 THEN (next code)
      Eaaaaaaa yyyy  [aaaaaaa]=[aaaaaaa]+yyyy
      Faaaaaaa yyyy  IF [aaaaaaa] AND yyyy THEN (next code)

Codebreaker Enable Codes
Hook Address 'aaaaaaa' is a 25bit offset in ROM-image (0-1FFFFFFh).
Flag byte 'y' (usually 0Ah), Bit1=Disable IRQs, Bit3=CRC Exists.
Code Handler Store Address 'z' (0-7, usually 7) (8000100h+z*400000h).
Checksum 'xxxx' for first 64Kbytes of cartridge (no$gba pads by FFh if ROM is smaller than 64K). Calculated, by using unsigned 16bit values, as such:

      crc=FFFFh
      for i=0 to FFFFh
       x=byte[i] xor (crc/100h)
       x=x xor (x/10h)
       crc=(crc*100h) xor (x*1001h) xor (x*20h)
      next i

Codebreaker Encryption
codebreaker_change_encryption:
Encryption can be (optionally) activated by code "9xyyxxxx xxxx",

      for i=0 to 2Fh, swaplist[i]=i, next i
      randomizer = 1111h xor byte[code+4]                              ;LSB value
      for i=0 to 4Fh
        exchange swaplist[random MOD 30h] with swaplist[random MOD 30h]
      next i
      halfword[seedlist+0] = halfword[code+0]                          ;LSW address
      randomizer = 4EFAD1C3h
      for i=0 to byte[code+3]-91h, randomizer=random, next i           ;MSB address
      word[seedlist+2]=random, halfword[seedlist+6]=random
      randomizer = F254h xor byte[code+5]                              ;MSB value
      for i=0 to byte[code+5]-01h, randomizer=random, next i           ;MSB value
      word[seedlist+8]=random, halfword[seedlist+12]=random
      ;note: byte[code+2] = don't care
      ret

The above random function works like so:

      randomizer=randomizer*41C64E6Dh+3039h, x=(randomizer SHL 14 AND C0000000h)
      randomizer=randomizer*41C64E6Dh+3039h, x=(randomizer SHR 1  AND 3FFF8000h)+x
      randomizer=randomizer*41C64E6Dh+3039h, x=(randomizer SHR 16 AND 00007FFFh)+x
      return(x)

Once when encryption is activated, all following codes are decrypted like so:

      for i=2Fh to 0
        j=swaplist[i]
        bitno1=(i AND 7), index1=xlatlist[i/8]
        bitno2=(j AND 7), index2=xlatlist[j/8]
        exchange [code+index1].bitno1 with [code+index2].bitno2
      next i
      word[code+0] = word[code+0] xor word[seedlist+8]
      i = (byte[code+3]*1010000h + byte[code+0]*100h + byte[code+5])
      i = (halfword[code+1]*10001h) xor (word[seedlist+2]) xor i
      i = (byte[seedlist+0]*1010101h) xor (byte[seedlist+1]*1000000h) xor i
      j = (byte[code+5] + (byte[code+0] xor byte[code+4])*100h)
      j = (byte[seedlist+0]*101h) xor halfword[seedlist+6] xor j
      word[code+0] = i, halfword[code+4] = j

The above xlatlist is fixed: xlatlist[0..5] = 3,2,1,0,5,4

GBA Cheat Codes - Gameshark/Action Replay V1/V2

Gameshark RAW Codes (These codes must be encrypted before using them)

      0aaaaaaa 000000xx  [aaaaaaa]=xx
      1aaaaaaa 0000xxxx  [aaaaaaa]=xxxx
      2aaaaaaa xxxxxxxx  [aaaaaaa]=xxxxxxxx
      3000cccc xxxxxxxx  write xxxxxxxx to (cccc-1) addresses (list in next codes)
      aaaaaaaa aaaaaaaa  parameter for above code, containing two addresses each
      aaaaaaaa 00000000  last parameter for above, zero-padded if only one address
      60aaaaaa y000xxxx  [8000000h+aaaaaa*2]=xxxx (ROM Patch)
      8a1aaaaa 000000xx  IF GS_Button_Down THEN [a0aaaaa]=xx
      8a2aaaaa 0000xxxx  IF GS_Button_Down THEN [a0aaaaa]=xxxx
      80F00000 0000xxxx  IF GS_Button_Down THEN slowdown xxxx * ? cycles per hook
      Daaaaaaa 0000xxxx  IF [aaaaaaa]=xxxx THEN (next code)
      E0zzxxxx 0aaaaaaa  IF [aaaaaaa]=xxxx THEN (next 'zz' codes)
      Faaaaaaa 00000x0y  Enable Code - Hook Routine
      xxxxxxxx 001DC0DE  Enable Code - Game Code ID (value at [0ACh] in cartridge)
      DEADFACE 0000xxyy  Change Encryption Seeds

Enable Code - Hook Routine
Hook Address 'aaaaaaa' is a 28bit ROM address (8FFFFFFh-9FFFFFFh).
Used to insert the GS code handler routine where it will be executed at
least 20 times per second. Without this code, GSA can not write to RAM.

     y=1 - Executes code handler without backing up the LR register.
     y=2 - Executes code handler and backs up the LR register.
     y=3 - Replaces a 32-bit pointer used for long-branches.
     x=0 - Must turn GSA off before loading game.
     x=1 - Must not do that.

ROM Patch
This type allows GSA to intercept ROM reads and returns the value xxxx.

     y=0 wait for the code handler to enable the patch
     y=1 patch is enabled before the game starts
     y=2 unknown ?

Note: V1/V2 hardware can only have up to 1 user-defined rom patch max. V3 can have up to 4. Some enable code types can shorten the amount of user-defined rom patches available.
Gameshark Encryption
A=Left half, and V=Right half of code.

      FOR I=1 TO 32
        A=A + (V*16+S0) XOR (V+I*9E3779B9h) XOR (V/32+S1)
        V=V + (A*16+S2) XOR (A+I*9E3779B9h) XOR (A/32+S3)
      NEXT I

Upon startup, the initial encryption seeds are:

      S0=09F4FBBDh S1=9681884Ah S2=352027E9h S3=F3DEE5A7h

Upon DEADFACE 0000xxyy, the S0..S3 seeds are changed like so:

      FOR y=0 TO 3
       FOR x=0 TO 3
        z = T1[(xx+x) AND FFh] + T2[(yy+y) AND FFh]
        Sy = Sy*100h + (z AND FFh)
       NEXT x
      NEXT y

All calculations truncated to unsigned 32bit integer values.
T1 and T2 are translation tables contained in the gameshark cartridge.

GBA Cheat Codes - Pro Action Replay V3

Pro Action Replay V3 - RAW Codes

      C4aaaaaa 0000yyyy  Enable Code - Hook Routine at [8aaaaaa]
      xxxxxxxx 001DC0DE  Enable Code - ID Code [080000AC]
      DEADFACE 0000xxxx  Enable Code - Change Encryption Seeds
      00aaaaaa xxxxxxyy  [a0aaaaa..a0aaaaa+xxxxxx]=yy
      02aaaaaa xxxxyyyy  [a0aaaaa..a0aaaaa+xxxx*2]=yyyy
      04aaaaaa yyyyyyyy  [a0aaaaa]=yyyyyyyy
      40aaaaaa xxxxxxyy  [ [a0aaaaa] + xxxxxx ]=yy   (Indirect)
      42aaaaaa xxxxyyyy  [ [a0aaaaa] + xxxx*2 ]=yyyy (Indirect)
      44aaaaaa yyyyyyyy  [ [a0aaaaa] ]=yyyyyyyy      (Indirect)
      80aaaaaa 000000yy  [a0aaaaa]=[a0aaaaa]+yy
      82aaaaaa 0000yyyy  [a0aaaaa]=[a0aaaaa]+yyyy
      84aaaaaa yyyyyyyy  [a0aaaaa]=[a0aaaaa]+yyyyyyyy
      C6aaaaaa 0000yyyy  [4aaaaaa]=yyyy              (I/O Area)
      C7aaaaaa yyyyyyyy  [4aaaaaa]=yyyyyyyy          (I/O Area)
      iiaaaaaa yyyyyyyy  IF [a0aaaaa] <cond> <value> THEN <action>
      00000000 60000000  ELSE (?)
      00000000 40000000  ENDIF (?)
      00000000 0800xx00  AR Slowdown : loops the AR xx times
      00000000 00000000  End of the code list
      00000000 10aaaaaa 000000zz 00000000  IF AR_BUTTON THEN [a0aaaaa]=zz
      00000000 12aaaaaa 0000zzzz 00000000  IF AR_BUTTON THEN [a0aaaaa]=zzzz
      00000000 14aaaaaa zzzzzzzz 00000000  IF AR_BUTTON THEN [a0aaaaa]=zzzzzzzz
      00000000 18aaaaaa 0000zzzz 00000000  [8000000+aaaaaa*2]=zzzz  (ROM Patch 1)
      00000000 1Aaaaaaa 0000zzzz 00000000  [8000000+aaaaaa*2]=zzzz  (ROM Patch 2)
      00000000 1Caaaaaa 0000zzzz 00000000  [8000000+aaaaaa*2]=zzzz  (ROM Patch 3)
      00000000 1Eaaaaaa 0000zzzz 00000000  [8000000+aaaaaa*2]=zzzz  (ROM Patch 4)

      00000000 80aaaaaa 000000yy ssccssss  repeat cc times [a0aaaaa]=yy
       (with yy=yy+ss, a0aaaaa=a0aaaaa+ssss after each step)

      00000000 82aaaaaa 0000yyyy ssccssss  repeat cc times [a0aaaaa]=yyyy
       (with yyyy=yyyy+ss, a0aaaaa=a0aaaaa+ssss*2 after each step)

      00000000 84aaaaaa yyyyyyyy ssccssss  repeat cc times [a0aaaaa]=yyyyyyyy
       (with yyyy=yyyy+ss, a0aaaaa=a0aaaaa+ssss*4 after each step)

Warning: There is a bug on the real AR (v2 upgraded to v3, and maybe on real v3) with the 32bit Increment Slide code. You HAVE to add a code (best choice is 80000000 00000000 : add 0 to value at address 0) right after it, else the AR will erase the 2 last 8 digits lines of the 32 Bits Inc. Slide code when you enter it !!!
Final Notes
The 'turn off all codes' makes an infinite loop (that can't be broken, unless the condition becomes True). - How? By Interrupt? Huh?
ROM Patch1 works on real V3 and, on V1/V2 upgraded to V3.
ROM Patch2,3,4 work on real V3 hardware only.
Pro Action Replay V3 Conditional Codes - iiaaaaaa yyyyyyyy
The 'ii' is composed of <cond> + <value> + <action>.

      <cond>           <value>            <action>
      08 Equal =       00 8bit zz         00 execute next code
      10 Not equal <>  02 16bit zzzz      40 execute next two codes
      18 Signed <      04 32bit zzzzzzzz  80 execute all following
      20 Signed >      06 (always false)     codes until ELSE or ENDIF
      28 Unsigned <                       C0 normal ELSE turn off all codes
      30 Unsigned >
      38 Logical AND

For example, ii=18h+02h+40h=5Ah, produces IF [a0aaaaa]<zzzz THEN next 2 codes.
Always... Codes

      For the "Always..." codes:
      - XXXXXXXX can be any authorised address except 00000000 (eg. use 02000000).
      - ZZZZZZZZ can be anything.
      - The "y" in the code data must be in the [1-7] range (which means not 0).
      typ=y,sub=0,siz=3   Always skip next line.
      typ=y,sub=1,siz=3   Always skip next 2 lines.
      typ=y,sub=2,siz=3   Always Stops executing all the codes below.
      typ=y,sub=3,siz=3   Always turn off all codes.

Code Format (ttaaaaaa xxxxyyzz)

     adr mask = 003FFFFF
     n/a mask = 00C00000 ;not used
     xtr mask = 01000000 ;used only by I/O write, and MSB of Hook
     siz mask = 06000000
     typ mask = 38000000 ;0=normal, other=conditional
     sub mask = C0000000

Pro Action Replay V3 Encryption
Works exactly as for Gameshark Encryption, but with different initial seeds,

      S0=7AA9648Fh S1=7FAE6994h S2=C0EFAAD5h S3=42712C57h

And, the T1 and T2 translation tables are different, too.

GBA Gameboy Player

The Gameboy Player is an "adapter" for the Gamecube console. It's basicly is a GBA in a black box without LCD screen and without buttons, connected to an expansion port at the bottom of the Gamecube. The Gamecube is then capturing the GBA video output (and passing it to the television set), and in the other direction, passing the Gamecube joypad input to the GBA inputs.
Unlocking and Detecting Gameboy Player Functions
Both unlocking and detection requires to display the 240x160 pixel Gameboy Player logo (44 colors) for a number of frames... maybe at least 3-4 frames? not sure if it checks the color of the logo... so maybe it can be hidden by using dark gray on black background?
While displaying this logo, the joypad data will switch between values 03FFh (2 frames duration) and 030Fh (1 frame duration). The latter value (left, right, up, down all pressed) indicates that it's a Gameboy Player.
Palette
Knowing Nintendo, they've probably not reproduced the blurred GBA colors (?), so the games won't look as desired on the TV screen. Unless the game does detect the Gameboy Player, and adjust the colors accordingly by software.
Rumble
The only known existing special function is the joypad rumble function, controlled by sending data through the serial port (the normal GBA port, even though it also has the connectors).
The Game Boy Player added a rumble feature to certain Game Boy Advance games when played with a GameCube controller. Those games included:

     Drill Dozer (supports BOTH handheld-rumble and GBP-rumble?)
     Mario & Luigi: Superstar Saga
     Pokemon Pinball: Ruby & Sapphire
     Shikakui Atama wo Marukusuru Advance: Kokugo Sansu Rika Shakai
     Shikakui Atama wo Marukusuru Advance: Kanji Keisan
     Summon Night Craft Sword Monogatari: Hajimari no Ishi
     Super Mario Advance 4: Super Mario Bros. 3

Fredrik Olsson (aka Flubba) has implemented rumble in 3 applications now RumblePong (FluBBA) (homebrew)

      Remudvance (FluBBA) (homebrew)
      Goomba (FluBBA) (8bit Gameboy Color Emulator for 32bit GBA) (homebrew)
      and, supposedly in "Tetanus on Drugs" (Tepples) (homebrew)

The GBP can also use some of the extra controllers for the GC like the Bongas
from Donkey Konga.
The logo requires at least 256 colors, it doesn't matter if you use a tiled
screen mode or a bitmapped one, the logo can be ripped from either
"Pokemon Pinball" or "Super Mario Advance 4".
Rumble
After detecting/unlocking the Gameboy Player, init RCNT and SIOCNT to 32bit normal mode, external clock, SO=high, with IRQ enabled, and set the transfer start bit. You should then receive the following sequence (about once per frame), and your serial IRQ handler should send responses accordingly:

      Receive  Response
      0000494E 494EB6B1
      xxxx494E 494EB6B1
      B6B1494E 544EB6B1
      B6B1544E 544EABB1
      ABB1544E 4E45ABB1
      ABB14E45 4E45B1BA
      B1BA4E45 4F44B1BA
      B1BA4F44 4F44B0BB
      B0BB4F44 8000B0BB
      B0BB8002 10000010
      10000010 20000013
      20000013 40000004
      30000003 40000004
      30000003 40000004
      30000003 40000004
      30000003 400000yy
      30000003 40000004

The first part of the transfer just contains the string "NINTENDO" split into 16bit fragments, and bitwise inversions thereof (eg. 494Eh="NI", and B6B1h=NOT 494Eh). In the second part, <yy> should be 04h=RumbleOff, or 26h=RumbleOn.
Note
If it's having a similar range of functions as the 8bit Super Gameboy, then the Gameboy Player might be also able to access analogue joypad input, and to access other features of the Gamecube hardware, up to possibly executing code on the Gamecube CPU...?

GBA Unpredictable Things

Forward
Most of the below is caused by 'traces' from previous operations which have used the databus. No promises that the results are stable on all current or future GBA models, and/or under all temperature and interference circumstances.
Also, below specifies 32bit data accesses only. When reading units less than 32bit, data is rotated depending on the alignment of the originally specified address, and 8bit or 16bit are then isolated from the 32bit value as usually.
Reading from BIOS Memory (00000000-00003FFF)
The BIOS memory is protected against reading, the GBA allows to read opcodes or data only if the program counter is located inside of the BIOS area. If the program counter is not in the BIOS area, reading will return the most recent successfully fetched BIOS opcode (eg. the opcode at [00DCh+8] after startup and SoftReset, the opcode at [0134h+8] during IRQ execution, and opcode at [013Ch+8] after IRQ execution, and opcode at [0188h+8] after SWI execution).
Reading from Unused Memory (00004000-01FFFFFF,10000000-FFFFFFFF)
Accessing unused memory at 00004000h-01FFFFFFh, and 10000000h-FFFFFFFFh (and 02000000h-03FFFFFFh when RAM is disabled via Port 4000800h) returns the recently pre-fetched opcode. For ARM code this is simply:

      WORD = [$+8]

For THUMB code the result consists of two 16bit fragments and depends on the address area and alignment where the opcode was stored.
For THUMB code in Main RAM, Palette Memory, VRAM, and Cartridge ROM this is:

      LSW = [$+4], MSW = [$+4]

For THUMB code in BIOS or OAM (and in 32K-WRAM on Original-NDS (in GBA mode)):

      LSW = [$+4], MSW = [$+6]   ;for opcodes at 4-byte aligned locations
      LSW = [$+2], MSW = [$+4]   ;for opcodes at non-4-byte aligned locations

For THUMB code in 32K-WRAM on GBA, GBA SP, GBA Micro, NDS-Lite (but not NDS):

      LSW = [$+4], MSW = OldHI   ;for opcodes at 4-byte aligned locations
      LSW = OldLO, MSW = [$+4]   ;for opcodes at non-4-byte aligned locations

Whereas OldLO/OldHI are usually:

      OldLO=[$+2], OldHI=[$+2]

Unless the previous opcode's prefetch was overwritten; that can happen if the previous opcode was itself an LDR opcode, ie. if it was itself reading data:

      OldLO=LSW(data), OldHI=MSW(data)
      Theoretically, this might also change if a DMA transfer occurs.

Note: Additionally, as usually, the 32bit data value will be rotated if the data address wasn't 4-byte aligned, and the upper bits of the 32bit value will be masked in case of LDRB/LDRH reads.
Note: The opcode prefetch is caused by the prefetch pipeline in the CPU itself, not by the external gamepak prefetch, ie. it works for code in ROM and RAM as well.
Reading from Unused or Write-Only I/O Ports
Works like above Unused Memory when the entire 32bit memory fragment is Unused (eg. 0E0h) and/or Write-Only (eg. DMA0SAD). And otherwise, returns zero if the lower 16bit fragment is readable (eg. 04Ch=MOSAIC, 04Eh=NOTUSED/ZERO).
Reading from GamePak ROM when no Cartridge is inserted
Because Gamepak uses the same signal-lines for both 16bit data and for lower 16bit halfword address, the entire gamepak ROM area is effectively filled by incrementing 16bit values (Address/2 AND FFFFh).
Memory Mirrors
Most internal memory is mirrored across the whole 24bit/16MB address space in which it is located: Slow On-board RAM at 2XXXXXX, Fast On-Chip RAM at 3XXXXXXh, Palette RAM at 5XXXXXXh, VRAM at 6XXXXXXh, and OAM at 7XXXXXXh. Even though VRAM is sized 96K (64K+32K), it is repeated in steps of 128K (64K+32K+32K, the two 32K blocks itself being mirrors of each other).
BIOS ROM, Normal ROM Cartridges, and I/O area are NOT mirrored, the only exception is the undocumented I/O port at 4000800h (repeated each 64K).
The 64K SRAM area is mirrored across the whole 32MB area at E000000h-FFFFFFFh, also, inside of the 64K SRAM field, 32K SRAM chips are repeated twice.
Writing 8bit Data to Video Memory
Video Memory (BG, OBJ, OAM, Palette) can be written to in 16bit and 32bit units only. Attempts to write 8bit data (by STRB opcode) won't work:
Writes to OBJ (6010000h-6017FFFh) (or 6014000h-6017FFFh in Bitmap mode) and to OAM (7000000h-70003FFh) are ignored, the memory content remains unchanged.
Writes to BG (6000000h-600FFFFh) (or 6000000h-6013FFFh in Bitmap mode) and to Palette (5000000h-50003FFh) are writing the new 8bit value to BOTH upper and lower 8bits of the addressed halfword, ie. "[addr AND NOT 1]=data*101h".
Using Invalid Tile Numbers
In Text mode, large tile numbers (combined with a non-zero character base setting in BGnCNT register) may exceed the available 64K of BG VRAM.
On GBA and GBA SP, such invalid tiles are displayed as if the character data is filled by the 16bit BG Map entry value (ie. as vertically striped tiles). Above applies only if there is only one BG layer enabled, with two or more layers, things are getting much more complicated: tile-data is then somehow derived from the other layers, depending on their priority order and scrolling offsets.
On NDS (in GBA mode), such invalid tiles are displayed as if the character data is zero-filled (ie. as invisible/transparent tiles).
Accessing SRAM Area by 16bit/32bit
Reading retrieves 8bit value from specified address, multiplied by 0101h (LDRH) or by 01010101h (LDR). Writing changes the 8bit value at the specified address only, being set to LSB of (source_data ROR (address*8)).

NDS Reference

Overview
DS Technical Data
DS I/O Maps
DS Memory Maps
Hardware Programming
DS Memory Control
DS Video
DS 3D Video
DS Sound
DS System and Built-in Peripherals
DS Cartridges, Encryption, Firmware
DS Xboo
DS Wireless Communications
Other
BIOS Functions
ARM CPU Reference
External Connectors

DS Technical Data

Processors

      1x ARM946E-S 32bit RISC CPU, 66MHz (NDS9 video) (not used in GBA mode)
      1x ARM7TDMI  32bit RISC CPU, 33MHz (NDS7 sound) (16MHz in GBA mode)

Internal Memory

      4096KB Main RAM (8192KB in debug version)
      96KB   WRAM (64K mapped to NDS7, plus 32K mappable to NDS7 or NDS9)
      60KB   TCM/Cache (TCM: 16K Data, 32K Code) (Cache: 4K Data, 8K Code)
      656KB  VRAM (allocateable as BG/OBJ/2D/3D/Palette/Texture/WRAM memory)
      4KB    OAM/PAL (2K OBJ Attribute Memory, 2K Standard Palette RAM)
      248KB  Internal 3D Memory (104K Polygon RAM, 144K Vertex RAM)
      ?KB    Matrix Stack, 48 scanline cache
      8KB    Wifi RAM
      256KB  Firmware FLASH (512KB in iQue variant, with chinese charset)
      36KB   BIOS ROM (4K NDS9, 16K NDS7, 16K GBA)

Video

      2x LCD screens (each 256x192 pixel, 3 inch, 18bit color depth, backlight)
      2x 2D video engines (extended variants of the GBA's video controller)
      1x 3D video engine (can be assigned to upper or lower screen)
      1x video capture (for effects, or for forwarding 3D to the 2nd 2D engine)

Sound

      16 sound channels (16x PCM8/PCM16/IMA-ADPCM, 6x PSG-Wave, 2x PSG-Noise)
      2 sound capture units (for echo effects, etc.)
      Output: Two built-in stereo speakers, and headphones socket
      Input:  One built-in microphone, and microphone socket

Controls

      Gamepad      4 Direction Keys, 8 Buttons
      Touchscreen  (on lower LCD screen)

Communication Ports

      Wifi IEEE802.11b

Specials

      Built-in Real Time Clock
      Power Managment Device
      Hardware divide and square root functions
      CP15 System Control Coprocessor (cache, tcm, pu, bist, etc.)

External Memory

      NDS Slot (for NDS games) (encrypted 8bit data bus, and serial 1bit bus)
      GBA Slot (for NDS expansions, or for GBA games) (but not for DMG/CGB games)

Manufactured Cartridges

      ROM: 16MB, 32MB, or 64MB
      EEPROM/FLASH/FRAM: 0.5KB, 8KB, 64KB, 256KB, or 512KB

Can be booted from

      NDS Cartridge (NDS mode)
      Firmware FLASH (NDS mode) (eg. by patching firmware via ds-xboo cable)
      Wifi (NDS mode)
      GBA Cartridge (GBA mode) (without DMG/CGB support) (without SIO support)

Power Supply

      Built-in rechargeable Lithium ion battery, 3.7V 1000mAh (DS-Lite)
      External Supply: 5.2V DC

NDS-Lite
Slightly smaller than the original NDS, coming in a more decently elegant case. The LCDs are much more colorful (and thus not backwards compatible with any older NDS or GBA games), and the LCDs support wider viewing angles. Slightly different power managment device (with selectable backlight brightness, new external power source flag, lost audio amplifier mute flag). Slightly different Wifi controller (different chip ID, different dirt effects when accessing invalid wifi ports and unused wifi memory regions, different behaviour on GAPDISP registers, RF/BB chips replaced by a single chip). Slightly different touch screen controller (with new unused input, and slightly different powerdown bits).
Notice
NDS9 means the ARM9 processor and its memory and I/O ports in NDS mode
NDS7 means the ARM7 processor and its memory and I/O ports in NDS mode
GBA means the ARM7 processor and its memory and I/O ports in GBA mode
The two Processors
Most game code is usually executed on the ARM9 processor (in fact, Nintendo reportedly doesn't allow developers use the ARM7 processor, except by predefined API functions, anyways, even with the most likely inefficient API code, most of the ARM7's 33MHz horsepower is left unused).
The ARM9's 66MHz "horsepower" is a different tale - it seems Nintendo thought that a 33MHz processor would be too "slow" for 3D games, and so they (tried to) badge an additional CPU to the original GBA hardware.
However, the real 66MHz can be used only with cache and tcm, all other memory and I/O accesses are delayed to the 33MHz bus clock, that'd be still quite fast, but, there seems to be a hardware glitch that adds 3 waitcycles to all nonsequential accesses at the NDS9 side, which effectively drops its bus clock to about 8MHz, making it ways slower than the 33MHz NDS7 processor, it's even slower than the original 16MHz GBA processor.
Altogether, with the bugged 66MHz, and the unused 33MHz, Nintendo could have reached almost the same power when staying with the GBA's 16MHz processor :-)
Although, when properly using cache/tcm, then the 66MHz processor <can> be very fast, still, the NDS should have worked as well with a single processor, though using only an ARM9 might cause a lot of compatibility problems with GBA games, so there's at least one reason for keeping the ARM7 included.

DS I/O Maps

ARM9 I/O Map
ARM9 Display Engine A

      4000000h  4    2D Engine A - DISPCNT - LCD Control (Read/Write)
      4000004h  2    2D Engine A+B - DISPSTAT - General LCD Status (Read/Write)
      4000006h  2    2D Engine A+B - VCOUNT - Vertical Counter (Read only)
      4000008h  50h  2D Engine A (same registers as GBA, some changed bits)
      4000060h  2    DISP3DCNT - 3D Display Control Register (R/W)
      4000064h  4    DISPCAPCNT - Display Capture Control Register (R/W)
      4000068h  4    DISP_MMEM_FIFO - Main Memory Display FIFO (R?/W)
      400006Ch  2    2D Engine A - MASTER_BRIGHT - Master Brightness Up/Down

GBA I/O Map
ARM9 DMA, Timers, and Keypad

      40000B0h  30h  DMA Channel 0..3
      40000E0h  10h  DMA FILL Registers for Channel 0..3
      4000100h  10h  Timers 0..3
      4000130h  2    KEYINPUT
      4000132h  2    KEYCNT

ARM9 IPC/ROM

      4000180h  2  IPCSYNC - IPC Synchronize Register (R/W)
      4000184h  2  IPCFIFOCNT - IPC Fifo Control Register (R/W)
      4000188h  4  IPCFIFOSEND - IPC Send Fifo (W)
      40001A0h  2  AUXSPICNT - Gamecard ROM and SPI Control
      40001A2h  2  AUXSPIDATA - Gamecard SPI Bus Data/Strobe
      40001A4h  4  Gamecard bus timing/control
      40001A8h  8  Gamecard bus 8-byte command out
      40001B0h  4  Gamecard Encryption Seed 0 Lower 32bit
      40001B4h  4  Gamecard Encryption Seed 1 Lower 32bit
      40001B8h  2  Gamecard Encryption Seed 0 Upper 7bit (bit7-15 unused)
      40001BAh  2  Gamecard Encryption Seed 1 Upper 7bit (bit7-15 unused)

ARM9 Memory and IRQ Control

      4000204h  2  EXMEMCNT - External Memory Control (R/W)
      4000208h  2  IME - Interrupt Master Enable (R/W)
      4000210h  4  IE  - Interrupt Enable (R/W)
      4000214h  4  IF  - Interrupt Request Flags (R/W)
      4000240h  1  VRAMCNT_A - VRAM-A (128K) Bank Control (W)
      4000241h  1  VRAMCNT_B - VRAM-B (128K) Bank Control (W)
      4000242h  1  VRAMCNT_C - VRAM-C (128K) Bank Control (W)
      4000243h  1  VRAMCNT_D - VRAM-D (128K) Bank Control (W)
      4000244h  1  VRAMCNT_E - VRAM-E (64K) Bank Control (W)
      4000245h  1  VRAMCNT_F - VRAM-F (16K) Bank Control (W)
      4000246h  1  VRAMCNT_G - VRAM-G (16K) Bank Control (W)
      4000247h  1  WRAMCNT   - WRAM Bank Control (W)
      4000248h  1  VRAMCNT_H - VRAM-H (32K) Bank Control (W)
      4000249h  1  VRAMCNT_I - VRAM-I (16K) Bank Control (W)

ARM9 Maths

      4000280h  2  DIVCNT - Division Control (R/W)
      4000290h  8  DIV_NUMER - Division Numerator (R/W)
      4000298h  8  DIV_DENOM - Division Denominator (R/W)
      40002A0h  8  DIV_RESULT - Division Quotient (=Numer/Denom) (R)
      40002A8h  8  DIVREM_RESULT - Division Remainder (=Numer MOD Denom) (R)
      40002B0h  2  SQRTCNT - Square Root Control (R/W)
      40002B4h  4  SQRT_RESULT - Square Root Result (R)
      40002B8h  8  SQRT_PARAM - Square Root Parameter Input (R/W)
      4000300h  4  POSTFLG - Undoc
      4000304h  2  POWCNT1 - Graphics Power Control Register (R/W)

ARM9 3D Display Engine

      4000320h..6A3h

DS 3D I/O Map
ARM9 Display Engine B

      4001000h  4    2D Engine B - DISPCNT - LCD Control (Read/Write)
      4001008h  50h  2D Engine B (same registers as GBA, some changed bits)
      400106Ch  2    2D Engine B - MASTER_BRIGHT - 16bit - Brightness Up/Down

ARM9 DSi Extra Registers

      40021Axh  ..  DSi Registers
      4004xxxh  ..  DSi Registers

ARM9 IPC/ROM

      4100000h  4    IPCFIFORECV - IPC Receive Fifo (R)
      4100010h  4    Gamecard bus 4-byte data in, for manual or dma read

ARM9 DS Debug Registers (Emulator/Devkits)

      4FFF0xxh  ..   Ensata Emulator Debug Registers
      4FFFAxxh  ..   No$gba Emulator Debug Registers

ARM9 Hardcoded RAM Addresses for Exception Handling

      27FFD9Ch   ..  NDS9 Debug Stacktop / Debug Vector (0=None)
      DTCM+3FF8h 4   NDS9 IRQ Check Bits (hardcoded RAM address)
      DTCM+3FFCh 4   NDS9 IRQ Handler (hardcoded RAM address)

Main Memory Control

      27FFFFEh  2    Main Memory Control

Further Memory Control Registers
ARM CP15 System Control Coprocessor
ARM7 I/O Map

      4000004h  2   DISPSTAT
      4000006h  2   VCOUNT
      40000B0h  30h DMA Channels 0..3
      4000100h  10h Timers 0..3
      4000120h  4   Debug SIODATA32
      4000128h  4   Debug SIOCNT
      4000130h  2   KEYINPUT
      4000132h  2   KEYCNT
      4000134h  2   Debug RCNT
      4000136h  2   EXTKEYIN
      4000138h  1   RTC Realtime Clock Bus
      4000180h  2   IPCSYNC - IPC Synchronize Register (R/W)
      4000184h  2   IPCFIFOCNT - IPC Fifo Control Register (R/W)
      4000188h  4   IPCFIFOSEND - IPC Send Fifo (W)
      40001A0h  2   AUXSPICNT - Gamecard ROM and SPI Control
      40001A2h  2   AUXSPIDATA - Gamecard SPI Bus Data/Strobe
      40001A4h  4   Gamecard bus timing/control
      40001A8h  8   Gamecard bus 8-byte command out
      40001B0h  4   Gamecard Encryption Seed 0 Lower 32bit
      40001B4h  4   Gamecard Encryption Seed 1 Lower 32bit
      40001B8h  2   Gamecard Encryption Seed 0 Upper 7bit (bit7-15 unused)
      40001BAh  2   Gamecard Encryption Seed 1 Upper 7bit (bit7-15 unused)
      40001C0h  2   SPI bus Control (Firmware, Touchscreen, Powerman)
      40001C2h  2   SPI bus Data

ARM7 Memory and IRQ Control

      4000204h  2   EXMEMSTAT - External Memory Status
      4000206h  2   WIFIWAITCNT
      4000208h  4   IME - Interrupt Master Enable (R/W)
      4000210h  4   IE  - Interrupt Enable (R/W)
      4000214h  4   IF  - Interrupt Request Flags (R/W)
      4000218h  -   IE2  ;\DSi only (additional ARM7 interrupt sources)
      400021Ch  -   IF2  ;/
      4000240h  1   VRAMSTAT - VRAM-C,D Bank Status (R)
      4000241h  1   WRAMSTAT - WRAM Bank Status (R)
      4000300h  1   POSTFLG
      4000301h  1   HALTCNT (different bits than on GBA) (plus NOP delay)
      4000304h  2   POWCNT2  Sound/Wifi Power Control Register (R/W)
      4000308h  4   BIOSPROT - Bios-data-read-protection address

ARM7 Sound Registers

      4000400h 100h Sound Channel 0..15 (10h bytes each)
      40004x0h  4   SOUNDxCNT - Sound Channel X Control Register (R/W)
      40004x4h  4   SOUNDxSAD - Sound Channel X Data Source Register (W)
      40004x8h  2   SOUNDxTMR - Sound Channel X Timer Register (W)
      40004xAh  2   SOUNDxPNT - Sound Channel X Loopstart Register (W)
      40004xCh  4   SOUNDxLEN - Sound Channel X Length Register (W)
      4000500h  2   SOUNDCNT - Sound Control Register (R/W)
      4000504h  2   SOUNDBIAS - Sound Bias Register (R/W)
      4000508h  1   SNDCAP0CNT - Sound Capture 0 Control Register (R/W)
      4000509h  1   SNDCAP1CNT - Sound Capture 1 Control Register (R/W)
      4000510h  4   SNDCAP0DAD - Sound Capture 0 Destination Address (R/W)
      4000514h  2   SNDCAP0LEN - Sound Capture 0 Length (W)
      4000518h  4   SNDCAP1DAD - Sound Capture 1 Destination Address (R/W)
      400051Ch  2   SNDCAP1LEN - Sound Capture 1 Length (W)

ARM7 DSi Extra Registers

      40021Axh  ..  DSi Registers
      4004xxxh  ..  DSi Registers
      4004700h  2   DSi SNDEXCNT Register  ;\mapped even in DS mode
      4004C0xh  ..  DSi GPIO Registers     ;/

ARM7 IPC/ROM

      4100000h  4   IPCFIFORECV - IPC Receive Fifo (R)
      4100010h  4   Gamecard bus 4-byte data in, for manual or dma read

ARM7 3DS

      4700000h  4   Disable ARM7 bootrom overlay (W) (3DS only)

ARM7 WLAN Registers

      4800000h  ..  Wifi WS0 Region (32K) (Wifi Ports, and 8K Wifi RAM)
      4808000h  ..  Wifi WS1 Region (32K) (mirror of above, other waitstates)

ARM7 Hardcoded RAM Addresses for Exception Handling

      380FFC0h  4   DSi7 IRQ IF2 Check Bits (hardcoded RAM address) (DSi only)
      380FFDCh  ..  NDS7 Debug Stacktop / Debug Vector (0=None)
      380FFF8h  4   NDS7 IRQ IF Check Bits (hardcoded RAM address)
      380FFFCh  4   NDS7 IRQ Handler (hardcoded RAM address)

DS Memory Maps

NDS9 Memory Map

      00000000h  Instruction TCM (32KB) (not moveable) (mirror-able to 1000000h)
      0xxxx000h  Data TCM        (16KB) (moveable)
      02000000h  Main Memory     (4MB)
      03000000h  Shared WRAM     (0KB, 16KB, or 32KB can be allocated to ARM9)
      04000000h  ARM9-I/O Ports
      05000000h  Standard Palettes (2KB) (Engine A BG/OBJ, Engine B BG/OBJ)
      06000000h  VRAM - Engine A, BG VRAM  (max 512KB)
      06200000h  VRAM - Engine B, BG VRAM  (max 128KB)
      06400000h  VRAM - Engine A, OBJ VRAM (max 256KB)
      06600000h  VRAM - Engine B, OBJ VRAM (max 128KB)
      06800000h  VRAM - "LCDC"-allocated (max 656KB)
      07000000h  OAM (2KB) (Engine A, Engine B)
      08000000h  GBA Slot ROM (max 32MB)
      0A000000h  GBA Slot RAM (max 64KB)
      FFFF0000h  ARM9-BIOS (32KB) (only 3K used)

The ARM9 Exception Vectors are located at FFFF0000h. The IRQ handler redirects to [DTCM+3FFCh].
NDS7 Memory Map

      00000000h  ARM7-BIOS (16KB)
      02000000h  Main Memory (4MB)
      03000000h  Shared WRAM (0KB, 16KB, or 32KB can be allocated to ARM7)
      03800000h  ARM7-WRAM (64KB)
      04000000h  ARM7-I/O Ports
      04800000h  Wireless Communications Wait State 0 (8KB RAM at 4804000h)
      04808000h  Wireless Communications Wait State 1 (I/O Ports at 4808000h)
      06000000h  VRAM allocated as Work RAM to ARM7 (max 256K)
      08000000h  GBA Slot ROM (max 32MB)
      0A000000h  GBA Slot RAM (max 64KB)

The ARM7 Exception Vectors are located at 00000000h. The IRQ handler redirects to [3FFFFFCh aka 380FFFCh].
Further Memory (not mapped to ARM9/ARM7 bus)

      3D Engine Polygon RAM (52KBx2)
      3D Engine Vertex RAM (72KBx2)
      Firmware (256KB) (built-in serial flash memory)
      GBA-BIOS (16KB) (not used in NDS mode)
      NDS Slot ROM (serial 8bit-bus, max 4GB with default protocol)
      NDS Slot FLASH/EEPROM/FRAM (serial 1bit-bus)

Shared-RAM
Even though Shared WRAM begins at 3000000h, programs are commonly using mirrors at 37F8000h (both ARM9 and ARM7). At the ARM7-side, this allows to use 32K Shared WRAM and 64K ARM7-WRAM as a continous 96K RAM block.
Undefined I/O Ports
On the NDS (at the ARM9-side at least) undefined I/O ports are always zero.
Undefined Memory Regions
16MB blocks that do not contain any defined memory regions (or that contain only mapped TCM regions) are typically completely undefined.
16MB blocks that do contain valid memory regions are typically containing mirrors of that memory in the unused upper part of the 16MB area (only exceptions are TCM and BIOS which are not mirrored).

DS Memory Control

Memory Control
DS Memory Control - Cache and TCM
DS Memory Control - Cartridges and Main RAM
DS Memory Control - WRAM
DS Memory Control - VRAM
DS Memory Control - BIOS
Memory Access Time
DS Memory Timings

DS Memory Control - Cache and TCM

TCM and Cache are controlled by the System Control Coprocessor,
ARM CP15 System Control Coprocessor
The specifications for the NDS9 are:
Tightly Coupled Memory (TCM)

      ITCM 32K, base=00000000h (fixed, not move-able)
      DTCM 16K, base=moveable  (default base=27C0000h)

Note: Although ITCM is NOT moveable, the NDS Firmware configures the ITCM size to 32MB, and so, produces ITCM mirrors at 0..1FFFFFFh. Furthermore, the PU can be used to lock/unlock memory in that region. That trick allows to move ITCM anywhere within the lower 32MB of memory.
Cache

      Data Cache 4KB, Instruction Cache 8KB
      4-way set associative method
      Cache line 8 words (32 bytes)
      Read-allocate method (ie. writes are not allocating cache lines)
      Round-robin and Pseudo-random replacement algorithms selectable
      Cache Lockdown, Instruction Prefetch, Data Preload
      Data write-through and write-back modes selectable

Protection Unit (PU)
Recommended/default settings are:

      Region  Name            Address   Size   Cache WBuf Code Data
      -       Background      00000000h 4GB    -     -    -    -
      0       I/O and VRAM    04000000h 64MB   -     -    R/W  R/W
      1       Main Memory     02000000h 4MB    On    On   R/W  R/W
      2       ARM7-dedicated  027C0000h 256KB  -     -    -    -
      3       GBA Slot        08000000h 128MB  -     -    -    R/W
      4       DTCM            027C0000h 16KB   -     -    -    R/W
      5       ITCM            01000000h 32KB   -     -    R/W  R/W
      6       BIOS            FFFF0000h 32KB   On    -    R    R
      7       Shared Work     027FF000h 4KB    -     -    -    R/W

Notes: In Nintendo's hardware-debugger, Main Memory is expanded to 8MB (for that reason, some addresses are at 27NN000h instead 23NN000h) (some of the extra memory is reserved for the debugger, some can be used for game development). Region 2 and 7 are not understood? GBA Slot should be max 32MB+64KB, rounded up to 64MB, no idea why it is 128MB? DTCM and ITCM do not use Cache and Write-Buffer because TCM is fast. Above settings do not allow to access Shared Memory at 37F8000h? Do not use cache/wbuf for I/O, doing so might suppress writes, and/or might read outdated values.
The main purpose of the Protection Unit is debugging, a major problem with GBA programs have been faulty accesses to memory address 00000000h and up (due to [base+offset] addressing with uninitialized (zero) base values). This problem has been fixed in the NDS, for the ARM9 processor at least, still there are various leaks: For example, the 64MB I/O and VRAM area contains only ca. 660KB valid addresses, and the ARM7 probably doesn't have a Protection Unit at all. Alltogether, the protection is better than in GBA, but it's still pretty crude compared with software debugging tools.
Region address/size are unified (same for code and data), however, cachabilty and access rights are non-unified (and may be separately defined for code and data).
Note: The NDS7 doesn't have any TCM, Cache, or CP15.

DS Memory Control - Cartridges and Main RAM

4000204h - NDS9 - EXMEMCNT - 16bit - External Memory Control (R/W)
4000204h - NDS7 - EXMEMSTAT - 16bit - External Memory Status (R/W..R)

      0-1   32-pin GBA Slot SRAM Access Time    (0-3 = 10, 8, 6, 18 cycles)
      2-3   32-pin GBA Slot ROM 1st Access Time (0-3 = 10, 8, 6, 18 cycles)
      4     32-pin GBA Slot ROM 2nd Access Time (0-1 = 6, 4 cycles)
      5-6   32-pin GBA Slot PHI-pin out   (0-3 = Low, 4.19MHz, 8.38MHz, 16.76MHz)
      7     32-pin GBA Slot Access Rights     (0=ARM9, 1=ARM7)
      8-10  Not used (always zero)
      11    17-pin NDS Slot Access Rights     (0=ARM9, 1=ARM7)
      12    Not used (always zero)
      13    NDS:Always set?  ;set/tested by DSi bootcode: Main RAM enable, CE2 pin?
      14    Main Memory Interface Mode Switch (0=Async/GBA/Reserved, 1=Synchronous)
      15    Main Memory Access Priority       (0=ARM9 Priority, 1=ARM7 Priority)

Bit0-6 can be changed by both NDS9 and NDS7, changing these bits affects the local EXMEM register only, not that of the other CPU.
Bit7-15 can be changed by NDS9 only, changing these bits affects both EXMEM registers, ie. both NDS9 and NDS7 can read the current NDS9 setting.
Bit14=0 is intended for GBA mode, however, writes to this bit appear to be ignored?
DS Main Memory Control
GBA Slot (8000000h-AFFFFFFh)
The GBA Slot can be mapped to ARM9 or ARM7 via EXMEMCNT.7.
For the selected CPU, memory at 8000000h-9FFFFFFh contains the "GBA ROM" region, and memory at A000000h-AFFFFFFh contains the "GBA SRAM" region (repeated every 64Kbytes). If there is no cartridge in GBA Slot, then the ROM/SRAM regions will contain open-bus values: SRAM region is FFh-filled (High-Z). And ROM region is filled by increasing 16bit values (Addr/2), possibly ORed with garbage depending on the selected ROM Access Time:

      6 clks   --> returns "Addr/2"
      8 clks   --> returns "Addr/2"
      10 clks  --> returns "Addr/2 OR FE08h" (or similar garbage)
      18 clks  --> returns "FFFFh" (High-Z)

For the deselected CPU, all memory at 8000000h-AFFFFFFh becomes 00h-filled, this is required for bugged games like Digimon Story: Super Xros Wars (which is accidently reading deselected GBA SRAM at [main_ram_base+main_ram_addr*4], whereas it does presumably want to read Main RAM at [main_ram_base+index*4]).

DS Memory Control - WRAM

4000247h - NDS9 - WRAMCNT - 8bit - WRAM Bank Control (R/W)
4000241h - NDS7 - WRAMSTAT - 8bit - WRAM Bank Status (R)
Should not be changed when using Nintendo's API.

      0-1   ARM9/ARM7 (0-3 = 32K/0K, 2nd 16K/1st 16K, 1st 16K/2nd 16K, 0K/32K)
      2-7   Not used

The ARM9 WRAM area is 3000000h-3FFFFFFh (16MB range).
The ARM7 WRAM area is 3000000h-37FFFFFh (8MB range).
The allocated 16K or 32K are mirrored everywhere in the above areas.
De-allocation (0K) is a special case: At the ARM9-side, the WRAM area is then empty (containing undefined data). At the ARM7-side, the WRAM area is then containing mirrors of the 64KB ARM7-WRAM (the memory at 3800000h and up).

DS Memory Control - VRAM

4000240h - NDS7 - VRAMSTAT - 8bit - VRAM Bank Status (R)

      0     VRAM C enabled and allocated to NDS7  (0=No, 1=Yes)
      1     VRAM D enabled and allocated to NDS7  (0=No, 1=Yes)
      2-7   Not used (always zero)

The register indicates if VRAM C/D are allocated to NDS7 (as Work RAM), ie. if VRAMCNT_C/D are enabled (Bit7=1), with MST=2 (Bit0-2). However, it does not reflect the OFS value.
4000240h - NDS9 - VRAMCNT_A - 8bit - VRAM-A (128K) Bank Control (W)
4000241h - NDS9 - VRAMCNT_B - 8bit - VRAM-B (128K) Bank Control (W)
4000242h - NDS9 - VRAMCNT_C - 8bit - VRAM-C (128K) Bank Control (W)
4000243h - NDS9 - VRAMCNT_D - 8bit - VRAM-D (128K) Bank Control (W)
4000244h - NDS9 - VRAMCNT_E - 8bit - VRAM-E (64K) Bank Control (W)
4000245h - NDS9 - VRAMCNT_F - 8bit - VRAM-F (16K) Bank Control (W)
4000246h - NDS9 - VRAMCNT_G - 8bit - VRAM-G (16K) Bank Control (W)
4000248h - NDS9 - VRAMCNT_H - 8bit - VRAM-H (32K) Bank Control (W)
4000249h - NDS9 - VRAMCNT_I - 8bit - VRAM-I (16K) Bank Control (W)

      0-2   VRAM MST              ;Bit2 not used by VRAM-A,B,H,I
      3-4   VRAM Offset (0-3)     ;Offset not used by VRAM-E,H,I
      5-6   Not used
      7     VRAM Enable (0=Disable, 1=Enable)

There is a total of 656KB of VRAM in Blocks A-I.
Table below shows the possible configurations.

      VRAM    SIZE  MST  OFS   ARM9, Plain ARM9-CPU Access (so-called LCDC mode)
      A       128K  0    -     6800000h-681FFFFh
      B       128K  0    -     6820000h-683FFFFh
      C       128K  0    -     6840000h-685FFFFh
      D       128K  0    -     6860000h-687FFFFh
      E       64K   0    -     6880000h-688FFFFh
      F       16K   0    -     6890000h-6893FFFh
      G       16K   0    -     6894000h-6897FFFh
      H       32K   0    -     6898000h-689FFFFh
      I       16K   0    -     68A0000h-68A3FFFh
      VRAM    SIZE  MST  OFS   ARM9, 2D Graphics Engine A, BG-VRAM (max 512K)
      A,B,C,D 128K  1    0..3  6000000h+(20000h*OFS)
      E       64K   1    -     6000000h
      F,G     16K   1    0..3  6000000h+(4000h*OFS.0)+(10000h*OFS.1)
      VRAM    SIZE  MST  OFS   ARM9, 2D Graphics Engine A, OBJ-VRAM (max 256K)
      A,B     128K  2    0..1  6400000h+(20000h*OFS.0)  ;(OFS.1 must be zero)
      E       64K   2    -     6400000h
      F,G     16K   2    0..3  6400000h+(4000h*OFS.0)+(10000h*OFS.1)
      VRAM    SIZE  MST  OFS   2D Graphics Engine A, BG Extended Palette
      E       64K   4    -     Slot 0-3  ;only lower 32K used
      F,G     16K   4    0..1  Slot 0-1 (OFS=0), Slot 2-3 (OFS=1)
      VRAM    SIZE  MST  OFS   2D Graphics Engine A, OBJ Extended Palette
      F,G     16K   5    -     Slot 0  ;16K each (only lower 8K used)
      VRAM    SIZE  MST  OFS   Texture/Rear-plane Image
      A,B,C,D 128K  3    0..3  Slot OFS(0-3)   ;(Slot2-3: Texture, or Rear-plane)
      VRAM    SIZE  MST  OFS   Texture Palette
      E       64K   3    -     Slots 0-3                 ;OFS=don't care
      F,G     16K   3    0..3  Slot (OFS.0*1)+(OFS.1*4)  ;ie. Slot 0, 1, 4, or 5
      VRAM    SIZE  MST  OFS   ARM9, 2D Graphics Engine B, BG-VRAM (max 128K)
      C       128K  4    -     6200000h
      H       32K   1    -     6200000h
      I       16K   1    -     6208000h
      VRAM    SIZE  MST  OFS   ARM9, 2D Graphics Engine B, OBJ-VRAM (max 128K)
      D       128K  4    -     6600000h
      I       16K   2    -     6600000h
      VRAM    SIZE  MST  OFS   2D Graphics Engine B, BG Extended Palette
      H       32K   2    -     Slot 0-3
      VRAM    SIZE  MST  OFS   2D Graphics Engine B, OBJ Extended Palette
      I       16K   3    -     Slot 0  ;(only lower 8K used)
      VRAM    SIZE  MST  OFS   <ARM7>, Plain <ARM7>-CPU Access
      C,D     128K  2    0..1  6000000h+(20000h*OFS.0)  ;OFS.1 must be zero

Notes
In Plain-CPU modes, VRAM can be accessed only by the CPU (and by the Capture Unit, and by VRAM Display mode). In "Plain <ARM7>-CPU Access" mode, the VRAM blocks are allocated as Work RAM to the NDS7 CPU.
In BG/OBJ VRAM modes, VRAM can be accessed by the CPU at specified addresses, and by the display controller.
In Extended Palette and Texture Image/Palette modes, VRAM is not mapped to CPU address space, and can be accessed only by the display controller (so, to initialize or change the memory, it should be temporarily switched to Plain-CPU mode).
All VRAM (and Palette, and OAM) can be written to only in 16bit and 32bit units (STRH, STR opcodes), 8bit writes are ignored (by STRB opcode). The only exception is "Plain <ARM7>-CPU Access" mode: The ARM7 CPU can use STRB to write to VRAM (the reason for this special feature is that, in GBA mode, two 128K VRAM blocks are used to emulate the GBA's 256K Work RAM).
Other Video RAM
Aside from the map-able VRAM blocks, there are also some video-related memory regions at fixed addresses:

      5000000h Engine A Standard BG Palette (512 bytes)
      5000200h Engine A Standard OBJ Palette (512 bytes)
      5000400h Engine B Standard BG Palette (512 bytes)
      5000600h Engine B Standard OBJ Palette (512 bytes)
      7000000h Engine A OAM (1024 bytes)
      7000400h Engine B OAM (1024 bytes)

DS Memory Control - BIOS

4000308h - NDS7 - BIOSPROT - Bios-data-read-protection address
Used to double-protect the first some KBytes of the NDS7 BIOS. The BIOS is split into two protection regions, one always active, one controlled by the BIOSPROT register. The overall idea is that only the BIOS can read from itself, any other attempts to read from that regions return FFh-bytes.

      Opcodes at...      Can read from      Expl.
      0..[BIOSPROT]-1    0..3FFFh           Double-protected (when BIOSPROT is set)
      [BIOSPROT]..3FFFh  [BIOSPROT]..3FFFh  Normal-protected (always active)

The initial BIOSPROT setting on power-up is zero (disabled). Before starting the cartridge, the BIOS boot code sets the register to 1204h (actually 1205h, but the mis-aligned low-bit is ignored). Once when initialized, further writes to the register are ignored.
The double-protected region contains the exception vectors, some bytes of code, and the cartridge KEY1 encryption seed (about 4KBytes). As far as I know, it is impossible to unlock the memory once when it is locked, however, with some trickery, it is possible execute code before it gets locked. Also, the two THUMB opcodes at 05ECh can be used to read all memory at 0..3FFFh,

      05ECh  ldrb r3,[r3,12h]      ;requires incoming r3=src-12h
      05EEh  pop  r2,r4,r6,r7,r15  ;requires dummy values & THUMB retadr on stack

Additionally most BIOS functions (eg. CpuSet), include a software-based protection which rejects source addresses in the BIOS area (the only exception is GetCRC16, though it still cannot bypass the BIOSPROT setting).
Note
The NDS9 BIOS doesn't include any software or hardware based read protection.

DS Memory Timings

System Clock

      Bus clock  = 33MHz (33.513982 MHz) (1FF61FEh Hertz)
      NDS7 clock = 33MHz (same as bus clock)
      NDS9 clock = 66MHz (internally twice bus clock; for cache/tcm)

Most timings in this document are specified for 33MHz clock (not for the 66MHz clock). Respectively, NDS9 timings are counted in "half" cycles.
Memory Access Times
Tables below show the different access times for code/data fetches on arm7/arm9 cpus, measured for sequential/nonsequential 32bit/16bit accesses.

      NDS7/CODE             NDS9/CODE
      N32 S32 N16 S16 Bus   N32 S32 N16 S16 Bus
      9   2   8   1   16    9   9   4.5 4.5 16  Main RAM (read) (cache off)
      1   1   1   1   32    4   4   2   2   32  WRAM,BIOS,I/O,OAM
      2   2   1   1   16    5   5   2.5 2.5 16  VRAM,Palette RAM
      16  12  10  6   16    19  19  9.5 9.5 16  GBA ROM (example 10,6 access)
      -   -   -   -   -     0.5 0.5 0.5 0.5 32  TCM, Cache_Hit
      -   -   -   -   -     (--Load 8 words--)  Cache_Miss

      NDS7/DATA             NDS9/DATA
      N32 S32 N16 S16 Bus   N32 S32 N16 S16 Bus
      10  2   9   1   16    10  2   9   1   16  Main RAM (read) (cache off)
      1   1   1   1   32    4   1   4   1   32  WRAM,BIOS,I/O,OAM
      1?  2   1   1   16    5   2   4   1   16  VRAM,Palette RAM
      15  12  9   6   16    19  12  13  6   16  GBA ROM (example 10,6 access)
      9   10  9   10  8     13  10  13  10  8   GBA RAM (example 10 access)
      -   -   -   -   -     0.5 0.5 0.5 -   32  TCM, Cache_Hit
      -   -   -   -   -     (--Load 8 words--)  Cache_Miss
      -   -   -   -   -     11  11  11  -   32  Cache_Miss (BIOS)
      -   -   -   -   -     23  23  23  -   16  Cache_Miss (Main RAM)

All timings are counted in 33MHz units (so "half" cycles can occur on NDS9).
Note: 8bit data accesses have same timings than 16bit data.
*** DS Memory Timing Notes ***
The NDS timings are altogether pretty messed up, with different timings for CODE and DATA fetches, and different timings for NDS7 and NDS9...
NDS7/CODE
Timings for this region can be considered as "should be" timings.
NDS7/DATA
Quite the same as NDS7/CODE. Except that, nonsequential Main RAM accesses are 1 cycle slower, and more strange, nonsequential GBA Slot accesses are 1 cycle faster.
NDS9/CODE
This is the most messiest timing. An infamous PENALTY of 3 cycles is added to all nonsequential accesses (except cache, tcm, and main ram). And, all opcode fetches are forcefully made nonsequential 32bit (the NDS9 simply doesn't support fast sequential opcode fetches). That applies also for THUMB code (two 16bit opcodes are fetched by a single nonsequential 32bit access) (so the time per 16bit opcode is one half of the 32bit fetch) (unless a branch causes only one of the two 16bit opcodes to be executed, then that opcode will have the full 32bit access time).
NDS9/DATA
Allows both sequential and nonsequential access, and both 16bit and 32bit access, so it's faster than NDS9/CODE. Nethertheless, it's still having the 3 cycle PENALTY on nonsequential accesses. And, similar as NDS7/DATA, it's also adding 1 cycle to nonsequential Main RAM accesses.
*** More Timing Notes / Lots of unsorted Info ***
Actual CPU Performance
The 33MHz NDS7 is running more or less nicely at 33MHz. However, the so-called "66MHz" NDS9 is having <much> higher waitstates, and it's effective bus speed is barely about 8..16MHz, the only exception is code/data in cache/tcm, which is eventually reaching real 66MHz (that, assuming cache HITS, otherwise, in case of cache MISSES, the cached memory timing might even drop to 1.4MHz or so?).
*********************
ARM9 opcode fetches are always N32 + 3 waits.

      S16 and N16 do not exist (because thumb-double-fetching) (see there).
      S32 becomes N32 (ie. the ARM9 does NOT support fast sequential timing).

That N32 is having same timing as normal N32 access on NDS7, plus 3 waits.

      Eg. an ARM9 N32 or S32 to 16bit bus will take: N16 + S16 + 3 waits.
      Eg. an ARM9 N32 or S32 to 32bit bus will take: N32 + 3 waits.

Main Memory is ALWAYS having the nonsequential 3 wait PENALTY (even on ARM7).
*********************
ARM9 Data fetches however are allowed to use sequential timing, as well as raw 16bit accesses (which aren't forcefully expanded to slow 32bit accesses).
Nethertheless, the 3 wait PENALTY is added to any NONSEQUENTIAL accesses.
Only exceptions are cache and tcm which do not have that penalty.

     Eg. LDRH on 16bit-data-bus is N16+3waits.
     Eg. LDR  on 16bit-data-bus is N16+S16+3waits.
     Eg. LDM  on 16bit-data-bus is N16+(n*2-1)*S16+3waits.

Eventually, data fetches can take place parallel with opcode fetches.

     That is NOT true for LDM (works only for LDR/LDRB/LDRH).
     That is NOT true for DATA in SAME memory region than CODE.
     That is NOT true for DATA in ITCM (no matter if CODE is in ITCM).

*********************
NDS9 Busses
Unlike ARM7, the ARM9 has separate code and data busses, allowing it to perform code and data fetches simultaneously (provided that both are in different memory regions).
Normally, opcode execution times are calculated as "(codetime+datatime)", with the two busses, it can (ideally) be "MAX(codetime,datatime)", so the data access time may virtually take "NULL" clock cycles.
In practice, DTCM and Data Cache access can take NULL cycles (however, data access to ITCM can't).
When executing code in cache/itcm, data access to non-cache/tcm won't be any faster than with only one bus (as it's best, it could subtract 0.5 cycles from datatime, but, the access must be "aligned" to the bus-clock, so the "datatime-0.5" will be rounded back to the original "datatime").
When executing code in uncached main ram, and accessing data (elsewhere than in main memory, cache/tcm), then execution time is typically "codetime+datatime-2".
NDS9 Internal Cycles
Additionally to codetime+datatime, some opcodes include one or more internal cycles. Compared with ARM7, the behaviour of that internal cycles is slightly different on ARM9. First of, on the NDS9, the internal cycles are of course "half" cycles (ie. counted in 66MHz units, not in 33MHz units) (although they may get rounded to "full" cycles upon next memory access outside tcm/cache). And, the ARM9 is in some cases "skipping" the internal cycles, that often depending on whether or not the next opcode is using the result of the current opcode.
Another big difference is that the ARM9 has lost the fast-multiply feature for small numbers; in some cases that may result in faster execution, but may also result in slower execution (one workaround would be to manually replace MUL opcodes by the new ARM9 halfword multiply opcodes); the slowest case are MUL opcodes that do update flags (eg. MULS, MLAS, SMULLS, etc. in ARM mode, and all ALL multiply opcodes in THUMB mode).
NDS9 Thumb Code
In thumb mode, the NDS9 is fetching two 16bit opcodes by a single 32bit read. In case of 32bit bus, this reduces the amount of memory traffic and may result in faster execution time, of course that works only if the two opcodes are within a word-aligned region (eg. loops at word-aligned addresses will be faster than non-aligned loops). However, the double-opcode-fetching is also done on 16bit bus memory, including for unnecessary fetches, such like opcodes after branch commands, so the feature may cause heavy slowdowns.
Main Memory
Reportedly, the main memory access times would be 5 cycles (nonsequential read), 4 cycles (nonsequential write), and 1 cycle (sequential read or write). Plus whatever termination cycles. Plus 3 cycles on nonsequential access to the last 2-bytes of a 32-byte block.
That's of course all wrong. Reads are much slower than 5 cycles. Not yet tested if writes are faster. And, I haven't been able to reproduce the 3 cycles on last 2-bytes effect, actually, it looks more as if that 3 cycles are accidently added to ALL nonsequential accesses, at ALL main memory addresses, and even to most OTHER memory regions... which might be the source of the PENALTY which occurs on VRAM/WRAM/OAM/Palette and I/O accesses.
DMA
In some cases DMA main memory read cycles are reportedly performed simultaneously with DMA write cycles to other memory.
NDS9
On the NDS9, all external memory access (and I/O) is delayed to bus clock (or actually MUCH slower due to the massive waitstates), so the full 66MHz can be used only internally in the NDS9 CPU core, ie. with cache and TCM.
Bus Clock
The exact bus clock is specified as 33.513982 MHz (1FF61FEh Hertz). However, on my own NDS, measured in relation to the RTC seconds IRQ, it appears more like 1FF6231h, that inaccuary of 1 cycle per 657138 cycles (about one second per week) on either oscillator, isn't too significant though.
GBA Slot
The access time for GBA slot can be configured via EXMEMCNT register.
VRAM Waitstates
Additionally, on NDS9, a one cycle wait can be added to VRAM accesses (when the video controller simultaneously accesses it) (that can be disabled by Forced Blank, see DISPCNT.Bit7). Moreover, additional VRAM waitstates occur when using the video capture function.
Note: VRAM being mapped to NDS7 is always free of additional waits.

DS Video

The NDS has two 2D Video Engines, each basically the same as in GBA, see
GBA LCD Video Controller
NDS Specific 2D Video Features
DS Video Stuff
DS Video BG Modes / Control
DS Video OBJs
DS Video Extended Palettes
DS Video Capture and Main Memory Display Mode
DS Video Display System Block Diagram
NDS/DSi File Formats for 2D video
DS Files - 2D Video
For Display Power Control (and Display Swap), and VRAM Allocation, see
DS Power Control
DS Power Management Device
DS Memory Control - VRAM

DS Video Stuff

DS Display Dimensions / Timings
Dot clock = 5.585664 MHz (=33.513982 MHz / 6)
H-Timing: 256 dots visible, 99 dots blanking, 355 dots total (15.7343KHz)
V-Timing: 192 lines visible, 71 lines blanking, 263 lines total (59.8261 Hz)
The V-Blank cycle for the 3D Engine consists of the 23 lines, 191..213.
Screen size 62.5mm x 47.0mm (each) (256x192 pixels)
Vertical space between screens 22mm (equivalent to 90 pixels)
400006Ch - NDS9 - MASTER_BRIGHT - 16bit - Master Brightness Up/Down

      0-4   Factor used for 6bit R,G,B Intensities (0-16, values >16 same as 16)
              Brightness up:   New = Old + (63-Old) * Factor/16
              Brightness down: New = Old - Old      * Factor/16
      5-13  Not used
      14-15 Mode (0=Disable, 1=Up, 2=Down, 3=Reserved)
      16-31 Not used

DISPSTAT/VCOUNT
The LY and LYC values are in range 0..262, so LY/LYC values have been expanded to 9bit values: LY = VCOUNT Bit 0..8, and LYC=DISPSTAT Bit8..15,7.
VCOUNT register is write-able, allowing to synchronize linked DS consoles.
For proper synchronization:

      write new LY values only in range of 202..212
      write only while old LY values are in range of 202..212

DISPSTAT/VCOUNT supported by NDS9 (Engine A Ports, without separate Engine B Ports), and by NDS7 (allowing to synchronize NDS7 with display timings).
Similar as on GBA, the VBlank flag isn't set in the last line (ie. only in lines 192..261, but not in line 262).
Although the drawing time is only 1536 cycles (256*6), the NDS9 H-Blank flag is "0" for a total of 1606 cycles (and, for whatever reason, a bit longer, 1613 cycles in total, on NDS7).
VRAM Waitstates
The display controller performs VRAM-reads once every 6 clock cycles, a 1 cycle waitstate is generated if the CPU simultaneously accesses VRAM. With capture enabled, additionally VRAM-writes take place once every 6 cycles, so the total VRAM-read/write access rate is then once every 3 cycles.
DS Window Glitches
The DS counts scanlines in range 0..262 (0..106h), of which only the lower 8bit are compared with the WIN0V/WIN1V register settings. Respectively, Y1 coordinates 00h..06h will be triggered in scanlines 100h-106h by mistake. That means, the window gets activated within VBlank period, and will be active in scanline 0 and up (that is no problem with Y1=0, but Y1=1..6 will appear as if if Y1 would be 0). Workaround would be to disable the Window during VBlank, or to change Y1 during VBlank (to a value that does not occur during VBlank period, ie. 7..191).
Also, there's a problem to fit the 256 pixel horizontal screen resolution into 8bit values: X1=00h is treated as 0 (left-most), X2=00h is treated as 100h (right-most). However, the window is not displayed if X1=X2=00h; the window width can be max 255 pixels.
2D Engines
Includes two 2D Engines, called A and B. Both engines are accessed by the ARM9 processor, each using different memory and register addresses:

      Region______Engine A______________Engine B___________
      I/O Ports   4000000h              4001000h
      Palette     5000000h (1K)         5000400h (1K)
      BG VRAM     6000000h (max 512K)   6200000h (max 128K)
      OBJ VRAM    6400000h (max 256K)   6600000h (max 128K)
      OAM         7000000h (1K)         7000400h (1K)

Engine A additionally supports 3D and large-screen 256-color Bitmaps, plus main-memory-display and vram-display modes, plus capture unit.
Viewing Angles
The LCD screens are best viewed at viewing angles of 90 degrees. Colors may appear distorted, and may even become invisible at other viewing angles.
When the console is handheld, both screens can be turned into preferred direction. When the console is settled on a table, only the upper screen can be turned, but the lower screen is stuck into horizontal position - which results in rather bad visibility (unless the user moves his/her head directly above of it).
4000070h - NDS9 - TVOUTCNT - Unknown (W)

      Bit0-3  "COMMAND"  (?)
      Bit4-7  "COMMAND2" (?)
      Bit8-11 "COMMAND3" (?)

This register has been mentioned in an early I/O map from Nintendo, as far as I know, the register isn't used by any games/firmware/bios, not sure if it does really exist on release-version, or if it's been prototype stuff...?
DS-Lite Screens
The screens in the DS-Lite seem to allow a wider range of vertical angles.
The bad news is that the colors of the DS-Lite are (no surprise) not backwards compatible with older NDS and GBA displays. The good news is that Nintendo has finally reached near-CRT-quality (without blurred colors), so one could hope that they won't show up with more displays with other colors in future.
Don't know if there's an official/recommended way to detect DS-Lite displays (?) possible methods would be whatever values in Firmware header, or by functionality of Power Managment device, or (not too LCD-related) by Wifi Chip ID.

DS Video BG Modes / Control

4000000h - NDS9 - DISPCNT

      Bit  Engine Expl.
      0-2   A+B   BG Mode
      3     A     BG0 2D/3D Selection (instead CGB Mode) (0=2D, 1=3D)
      4     A+B   Tile OBJ Mapping        (0=2D; max 32KB, 1=1D; max 32KB..256KB)
      5     A+B   Bitmap OBJ 2D-Dimension (0=128x512 dots, 1=256x256 dots)
      6     A+B   Bitmap OBJ Mapping      (0=2D; max 128KB, 1=1D; max 128KB..256KB)
      7-15  A+B   Same as GBA
      16-17 A+B   Display Mode (Engine A: 0..3, Engine B: 0..1, GBA: Green Swap)
      18-19 A     VRAM block (0..3=VRAM A..D) (For Capture & above Display Mode=2)
      20-21 A+B   Tile OBJ 1D-Boundary   (see Bit4)
      22    A     Bitmap OBJ 1D-Boundary (see Bit5-6)
      23    A+B   OBJ Processing during H-Blank (was located in Bit5 on GBA)
      24-26 A     Character Base (in 64K steps) (merged with 16K step in BGxCNT)
      27-29 A     Screen Base (in 64K steps) (merged with 2K step in BGxCNT)
      30    A+B   BG Extended Palettes   (0=Disable, 1=Enable)
      31    A+B   OBJ Extended Palettes  (0=Disable, 1=Enable)

BG Mode
Engine A BG Mode (DISPCNT LSBs) (0-6, 7=Reserved)

      Mode  BG0      BG1      BG2      BG3
      0     Text/3D  Text     Text     Text
      1     Text/3D  Text     Text     Affine
      2     Text/3D  Text     Affine   Affine
      3     Text/3D  Text     Text     Extended
      4     Text/3D  Text     Affine   Extended
      5     Text/3D  Text     Extended Extended
      6     3D       -        Large    -

Of which, the "Extended" modes are sub-selected by BGxCNT bits:

      BGxCNT.Bit7 BGxCNT.Bit2 Extended Affine Mode Selection
      0           CharBaseLsb rot/scal with 16bit bgmap entries (Text+Affine mixup)
      1           0           rot/scal 256 color bitmap
      1           1           rot/scal direct color bitmap

Engine B: Same as above, except that: Mode 6 is reserved (no Large screen bitmap), and BG0 is always Text (no 3D support).
Affine = formerly Rot/Scal mode (with 8bit BG Map entries)
Large Screen Bitmap = rot/scal 256 color bitmap (using all 512K of 2D VRAM)
Display Mode (DISPCNT.16-17):

      0  Display off (screen becomes white)
      1  Graphics Display (normal BG and OBJ layers)
      2  Engine A only: VRAM Display (Bitmap from block selected in DISPCNT.18-19)
      3  Engine A only: Main Memory Display (Bitmap DMA transfer from Main RAM)

Mode 2-3 display a raw direct color bitmap (15bit RGB values, the upper bit in each halfword is unused), without any further BG,OBJ,3D layers, these modes are completely bypassing the 2D/3D engines as well as any 2D effects, however the Master Brightness effect can be applied to these modes. Mode 2 is particulary useful to display captured 2D/3D images (in that case it can indirectly use the 2D/3D engine).
BGxCNT
character base extended from bit2-3 to bit2-5 (bit4-5 formerly unused)

      engine A screen base: BGxCNT.bits*2K + DISPCNT.bits*64K
      engine B screen base: BGxCNT.bits*2K + 0
      engine A char base: BGxCNT.bits*16K + DISPCNT.bits*64K
      engine B char base: BGxCNT.bits*16K + 0

char base is used only in tile/map modes (not bitmap modes)
screen base is used in tile/map modes,
screen base used in bitmap modes as BGxCNT.bits*16K, without DISPCNT.bits*64K
screen base however NOT used at all for Large screen bitmap mode

      bgcnt size  text     rotscal    bitmap   large bmp
      0           256x256  128x128    128x128  512x1024
      1           512x256  256x256    256x256  1024x512
      2           256x512  512x512    512x256  -
      3           512x512  1024x1024  512x512  -

bitmaps that require more than 128K VRAM are supported on engine A only.
For BGxCNT.Bit7 and BGxCNT.Bit2 in Extended Affine modes, see above BG Mode description (extended affine doesn't include 16-color modes, so color depth bit can be used for mode selection. Also, bitmap modes do not use charbase, so charbase.0 can be used for mode selection as well).

      for BG0CNT, BG1CNT only: bit13 selects extended palette slot
                               (BG0: 0=Slot0, 1=Slot2, BG1: 0=Slot1, 1=Slot3)

Direct Color Bitmap BG, and Direct Color Bitmap OBJ
BG/OBJ Supports 32K colors (15bit RGB value) - so far same as GBAs BG.
However, the upper bit (Bit15) is used as Alpha flag. That is, Alpha=0=Transparent, Alpha=1=Normal (ie. on the NDS, Direct Color values 0..7FFFh are NOT displayed).
Unlike GBA bitmap modes, NDS bitmap modes are supporting the Area Overflow bit (BG2CNT and BG3CNT, Bit 13).

DS Video OBJs

DS OBJ Priority
The GBA has been assigning OBJ priority in respect to the 7bit OAM entry number, regardless of the OBJs 2bit BG-priority attribute (which allowed to specify invalid priority orders). That problem has been fixed in DS mode by combining the above two values into a 9bit priority value.
OBJ Tile Mapping (DISPCNT.4,20-21):

      Bit4  Bit20-21  Dimension Boundary Total ;Notes
      0     x         2D        32       32K   ;Same as GBA 2D Mapping
      1     0         1D        32       32K   ;Same as GBA 1D Mapping
      1     1         1D        64       64K
      1     2         1D        128      128K
      1     3         1D        256      256K  ;Engine B: 128K max

TileVramAddress = TileNumber * BoundaryValue
Even if the boundary gets changed, OBJs are kept composed of 8x8 tiles.
Bitmap OBJ Mapping (DISPCNT.6,5,22):
Bitmap OBJs are 15bit Direct Color data, plus 1bit Alpha flag (in bit15).

      Bit6 Bit5 Bit22 Dimension    Boundary   Total ;Notes
      0    0    x     2D/128 dots  8x8 dots   128K  ;Source Bitmap width 128 dots
      0    1    x     2D/256 dots  8x8 dots   128K  ;Source Bitmap width 256 dots
      1    0    0     1D           128 bytes  128K  ;Source Width = Target Width
      1    0    1     1D           256 bytes  256K  ;Engine A only
      1    1    x     Reserved

In 1D mapping mode, the Tile Number is simply multiplied by the boundary value.

      1D_BitmapVramAddress = TileNumber(0..3FFh) * BoundaryValue(128..256)
      2D_BitmapVramAddress = (TileNo AND MaskX)*10h + (TileNo AND NOT MaskX)*80h

In 2D mode, the Tile Number is split into X and Y indices, the X index is located in the LSBs (ie. MaskX=0Fh, or MaskX=1Fh, depending on DISPCNT.5).
OBJ Attribute 0 and 2
Setting the OBJ Mode bits (Attr 0, Bit10-11) to a value of 3 has been prohibited in GBA, however, in NDS it selects the new Bitmap OBJ mode; in that mode, the Color depth bit (Attr 0, Bit13) should be set to zero; also in that mode, the color bits (Attr 2, Bit 12-15) are used as Alpha-OAM value (instead of as palette setting).
OBJ Vertical Wrap
On the GBA, a large OBJ (with 64pix height, scaled into double-size region of 128pix height) located near the bottom of the screen has been wrapped to the top of the screen (and was NOT displayed at the bottom of the screen).
This problem has been "corrected" in the NDS (except in GBA mode), that is, on the NDS, the OBJ appears BOTH at the top and bottom of the screen. That isn't necessarily better - the advantage is that one can manually enable/disable the OBJ in the desired screen-half on IRQ level; that'd be required only if the wrapped portion is non-transparent.

DS Video Extended Palettes

Extended Palettes
When allocating extended palettes, the allocated memory is not mapped to the CPU bus, so the CPU can access extended palette only when temporarily de-allocating it.
Color 0 of all standard/extended palettes is transparent, color 0 of BG standard palette 0 is used as backdrop. extended palette memory must be allocated to VRAM.
BG Extended Palette enabled in DISPCNT Bit 30, when enabled,

     standard palette --> 16-color tiles (with 16bit bgmap entries) (text)
                          256-color tiles (with 8bit bgmap entries) (rot/scal)
                          256-color bitmaps
                          backdrop-color (color 0)
     extended palette --> 256-color tiles (with 16bit bgmap entries)(text,rot/scal)

Allocated VRAM is split into 4 slots of 8K each (32K used in total), normally BG0..3 are using Slot 0..3, however BG0 and BG1 can be optionally changed to BG0=Slot2, and BG1=Slot3 via BG0CNT and BG1CNT.
OBJ Extended Palette enabled in DISPCNT Bit 31, when enabled,

     16 colors x 16 palettes --> standard palette memory (=256 colors)
     256 colors x 16 palettes --> extended palette memory (=4096 colors)

Extended OBJ palette memory must be allocated to VRAM F, G, or I (which are 16K) of which only the first 8K are used for extended palettes (=1000h 16bit entries).

DS Video Capture and Main Memory Display Mode

4000064h - NDS9 - DISPCAPCNT - 32bit - Display Capture Control Register (R/W)
Capture is supported for Display Engine A only.

      0-4   EVA               (0..16 = Blending Factor for Source A)
      5-7   Not used
      8-12  EVB               (0..16 = Blending Factor for Source B)
      13-15 Not used
      16-17 VRAM Write Block  (0..3 = VRAM A..D) (VRAM must be allocated to LCDC)
      18-19 VRAM Write Offset (0=00000h, 0=08000h, 0=10000h, 0=18000h)
      20-21 Capture Size      (0=128x128, 1=256x64, 2=256x128, 3=256x192 dots)
      22-23 Not used
      24    Source A          (0=Graphics Screen BG+3D+OBJ, 1=3D Screen)
      25    Source B          (0=VRAM, 1=Main Memory Display FIFO)
      26-27 VRAM Read Offset  (0=00000h, 0=08000h, 0=10000h, 0=18000h)
      28    Not used
      29-30 Capture Source    (0=Source A, 1=Source B, 2/3=Sources A+B blended)
      31    Capture Enable    (0=Disable/Ready, 1=Enable/Busy)

Notes:
VRAM Read Block (VRAM A..D) is selected in DISPCNT Bits 18-19.
VRAM Read Block can be (or must be ?) allocated to LCDC (MST=0).
VRAM Read Offset is ignored (zero) in VRAM Display Mode (DISPCNT.16-17).
VRAM Read/Write Offsets wrap to 00000h when exceeding 1FFFFh (max 128K).
Capture Sizes less than 256x192 capture the upper-left portion of the screen.
Blending factors EVA and EVB are used only if "Source A+B blended" selected.
After setting the Capture Enable bit, capture starts at next line 0, and the capture enable/busy bit is then automatically cleared (in line 192, regardless of the capture size).
Capture data is 15bit color depth (even when capturing 18bit 3D-images).
Capture A: Dest_Intensity = SrcA_Intensitity ; Dest_Alpha=SrcA_Alpha.
Capture B: Dest_Intensity = SrcB_Intensitity ; Dest_Alpha=SrcB_Alpha.
Capture A+B (blending):

     Dest_Intensity = (  (SrcA_Intensitity * SrcA_Alpha * EVA)
                       + (SrcB_Intensitity * SrcB_Alpha * EVB) ) / 16
     Dest_Alpha = (SrcA_Alpha AND (EVA>0)) OR (SrcB_Alpha AND EVB>0))

Capture provides a couple of interesting effects.
For example, 3D Engine output can be captured via source A (to LCDC-allocated VRAM), in the next frame, either Graphics Engine A or B can display the captured 3D image in VRAM image as BG2, BG3, or OBJ (from BG/OBJ-allocated VRAM); this method requires to switch between LCDC- and BG/OBJ-allocation.
Another example would be to capture Engine A output, the captured image can be displayed (via VRAM Display mode) in the following frames, simultaneously the new Engine A output can be captured, blended with the old captured image; in that mode moved objects will leave traces on the screen; this method works with a single LCDC-allocated VRAM block.
DS Video Display System Block Diagram
4000068h - NDS9 - DISP_MMEM_FIFO - 32bit - Main Memory Display FIFO (R?/W)
Intended to send 256x192 pixel 32K color bitmaps by DMA directly

     - to Screen A             (set DISPCNT to Main Memory Display mode), or
     - to Display Capture unit (set DISPCAPCNT to Main Memory Source).

The FIFO can receive 4 words (8 pixels) at a time, each pixel is a 15bit RGB value (the upper bit, bit15, is unused).
Set DMA to Main Memory mode, 32bit transfer width, word count set to 4, destination address to DISP_MMEM_FIFO, source address must be in Main Memory.
Transfer starts at next frame.
Main Memory Display/Capture is supported for Display Engine A only.

DS Video Display System Block Diagram

                 _____________               __________
      VRAM A -->| 2D Graphics |--------OBJ->|          |
      VRAM B -->| Engine A    |--------BG3->| Layering |
      VRAM C -->|             |--------BG2->| and      |
      VRAM D -->|             |--------BG1->| Special  |
      VRAM E -->|             |   ___       | Effects  |
      VRAM F -->|             |->|SEL|      |          |          ______
      VRAM G -->| - - - - - - |  |BG0|-BG0->|          |----o--->|      |
                | 3D Graphics |->|___|      |__________|    |    |Select|
                | Engine      |                             |    |Video |
                |_____________|--------3D----------------.  |    |Input |
                 _______      _______              ___   |  |    |      |
                |       |    |       |<-----------|SEL|<-'  |    |and   |-->
                |       |    |       |    _____   |A  |     |    |      |
      VRAM A <--|Select |    |Select |   |     |<-|___|<----'    |Master|
      VRAM B <--|Capture|<---|Capture|<--|Blend|   ___           |Bright|
      VRAM C <--|Dest.  |    |Source |   |_____|<-|SEL|<----.    |A     |
      VRAM D <--|       |    |       |            |B  |     |    |      |
                |_______|    |_______|<-----------|___|<-.  |    |      |
                 _______                                 |  |    |      |
      VRAM A -->|Select |                                |  |    |      |
      VRAM B -->|Display|--------------------------------o------>|      |
      VRAM C -->|VRAM   |                                   |    |      |
      VRAM D -->|_______|   _____________                   |    |      |
                           |Main Memory  |                  |    |      |
      Main   ------DMA---->|Display FIFO |------------------o--->|______|
      Memory               |_____________|
                 _____________               __________           ______
      VRAM C -->| 2D Graphics |--------OBJ->| Layering |         |      |
      VRAM D -->| Engine B    |--------BG3->| and      |         |Master|
      VRAM H -->|             |--------BG2->| Special  |-------->|Bright|-->
      VRAM I -->|             |--------BG1->| Effects  |         |B     |
                |_____________|--------BG0->|__________|         |______|

DS Files - 2D Video

eg. used in DSi Launcher "rom:\layout\cmn\launcher_d.szs\.."
http://www.romhacking.net/documents/[469]nds_formats.htm

     ____________________________ Nitro Color Palette _____________________________

Header

      000h 4    Chunk ID "RLCN" (aka NCLR backwards, Nitro Color Resource)
      004h 2    Byte Order    (FEFFh)
      006h 2    Version       (0100h)
      008h 4    Total Filesize
      00Ch 2    Offset to "TTLP" Chunk, aka Size of "RLCN" Chunk (0010h)
      00Eh 2    Total number of following Chunks (1=TTLP) (or 2=TTLP+PMCP ?)

TTLP Chunk

      000h 4    Chunk ID "TTLP" (aka PLTT backwards, Palette data)
      004h 4    Chunk Size (eg. 0218h)
      008h 4    Reportedly Color Depth (ie. "tile usage info") (3=4bpp, 4=8bpp)
      00Ch 4    Zero
      010h 4    Palette Data Size in bytes (eg. 200h) (or 200h-N? no, blah!)
      014h 4    Offset from TTLP+8 to Palette Data? (always 10h)
      018h N*2  Palete Data (16bit colors, 0000h..7FFFh)

Most DSi titles use full 200h-byte palettes (Paper Plane has a smaller one in Graphics.NARC\Seq\pause.zcl). There seem to be no DSi titles with PMCP chunks.
PMCP Chunk (if any) (reportedly exists, but not in DSi Launcher...?)

      000h 4    Chunk ID "PMCP" (aka PCMP backwards, Palette CMP?)
      004h 4    Chunk Size (reportedly always 12h ???)
      008h 2    Number of palettes in file (uh?)
      00Ah 2    Unused (BEEFh=Bullshit)
      00Ch 4    Offset from PMCP+8 to Palette IDs? (always 08h)
      DATA N*2  "Palette ID numbers for each palette (starting from 0)"

     ___________________________ Nitro Character Tiles ____________________________

      eg. DSi Launcher "rom:\debug\DebugFont.NCGR"         -- with SOPC chunk
      eg. DSi Launcher "rom:\layout\cmn\launcher_d.szs\.." -- without SOPC chunk

Header

      000h 4    Chunk ID "RGCN" (aka NCGR backwards, Nitro Char Graphics Resource)
      004h 2    Byte Order    (FEFFh)
      006h 2    Version       (0101h) (unknown if 0100h does also exist?)
      008h 4    Total Filesize
      00Ch 2    Offset to "RAHC" Chunk, aka Size of "RGCN" Chunk (0010h)
      00Eh 2    Total number of following Chunks (1=RAHC, or 2=RAHC+SOPC)

RAHC Chunk

      000h 4    Chunk ID "RAHC" (aka CHAR backwards)
      004h 4    Chunk Size (eg. 1420h)
      008h 2    Tile Data Size in Kilobytes   ;\or both set to FFFFh
      00Ah 2    Unknown (always 20h)          ;/(when size<>N*1024)
      00Ch 4    Color Depth (3=4bpp, 4=8bpp)
      010h 2    Zero   ;or 10h (when SOPC not exists? kbyte size rounded up?)
      012h 2    Zero   ;or 20h (when SOPC not exists?)
      014h 4    Zero
      018h 4    Tile Data Size in Bytes (eg. 1400h)
      01Ch 4    Offset from RAHC+8 to Tile Data?  ;=always 18h
      020h ...  Tile Data (eg. 20h-byte zerofilled for 4bpp SPC char?)

Nonzero [10h,12h] spotted in Paper Plane "rom:\Graphics.NARC\Plane\plane.zcg".
SOPC Chunk (only present if Tile Data size is N*1024 bytes)

      000h 4    Chunk ID "SOPC" (aka CPOS backwards)
      004h 4    Chunk Size (10h)
      008h 4    Zero
      00Ch 2    Same as [00Ah] in RAHC chunk? (always 20h)
      00Eh 2    Same as [008h] in RAHC chunk? (size in kilobytes)

     __________________________ Unknown Character Tiles ___________________________

Apart from above NCGR, there is reportedly another tile format:

      NCGR (Nitro Character Graphic Resource) - Graphical Tiles --> see above
      NBGR (Nitro Basic Graphic Resource)     - Graphical Tiles --> what ???

If it does really exist for real... the header ID be "RGBN" (aka NBGR backwards), and file extension might be NBGR? But even if so, it's unknown if/when/where/why that NBGR format is used. If the "B" is for "Basic" then might have less features than NCGR, or maybe it might be "B" for non-tiled Bitmaps, or whatever?

     ___________________________ Nitro BG Maps Screens ____________________________

Header

      000h 4    Chunk ID "RCSN" (aka NSCR backwards, Nitro Screen Resource)
      004h 2    Byte Order    (FEFFh)
      006h 2    Version       (0100h)
      008h 4    Total Filesize
      00Ch 2    Offset to "NRCS" Chunk, aka Size of "RCSN" Chunk (0010h)
      00Eh 2    Total number of following Chunks (1=NRCS)

NRCS Chunk

      000h 4    Chunk ID "NRCS" (aka SCRN backwards, Screen)
      004h 4    Chunk Size
      008h 4    Screen Width in pixels
      00Ah 2    Screen Height in pixels
      00Ch 4    Zero
      010h 4    Screen Data Size (width/8)*(height/8)*2
      014h N*2  Screen Data (16bit BG Map entries, palette+xyflip+tileno)

     ____________________________ Nitro OBJ Animations ____________________________

Header

      000h 4    Chunk ID "RNAN" (aka NANR backwards, Nitro Animation Resource)
      004h 2    Byte Order    (FEFFh)
      006h 2    Version       (0100h)
      008h 4    Total Filesize
      00Ch 2    Offset to "KNBA" Chunk, aka Size of "RNAN" Chunk (0010h)
      00Eh 2    Total number of following Chunks (1=KNBA, or 3=KNBA+LBAL+TXEU)

One chunk exists in DSi Launcher
Three chunks exist in DSi Flipnote "rom:ManualData.Eu\md2res_narc.blz\data\obj
KNBA Chunk

      000h 4    Chunk ID "KNBA" (aka ABNK backwards, Animation Bank)
      004h 4    Chunk Size (always padded to 4-byte boundary if LABL chunk follows)
      008h 2    Number of 16-byte Animation Blocks ;implies NumLabels in LABL chunk
      00Ah 2    Number of 8-byte Frame Blocks
      00Ch 4    Offset from KNBA+8 to Animation Blocks ;=18h
      010h 4    Offset from KNBA+8 to Frame Blocks     ;=[0Ch]+[08h]*10h
      014h 4    Offset from KNBA+8 to Frame Data       ;=[10h]+[0Ah]*8
      018h 8    Zero
      DATA ..   Animation Blocks (16-byte entries)
       00h 4      Number of Frames
       04h 2      Unknown        (0)
       06h 2      Unknown Always (1)   ;reportedly "always unknown"
       08h 4      Unknown        (1..2)
       0Ch 4      Offset from FrameBlock+0 to First Frame
      DATA ..   Frame Blocks (8-byte entries)
       00h 4      Offset from FrameData+0 to whatever?   (always 4-byte aligned?)
       04h 2      Frame Width   ;3Ch or 01..06h   ;Time in 60Hz units? num meta's?
       06h 2      Unused (usually 0000h, or BEEFh=Bullshit)
      DATA ..   Frame Data (2-byte entries)
       00h 2      Unknown 16bit values? (maybe CELL index or whatever??)  (CCCCh=?)

LBAL Chunk

      000h 4    Chunk ID "LBAL" (aka LABL backwards, Labels)
      004h 4    Chunk Size (not padded to 4-byte size, following TXEU is unaligned)
      008h 4*N  Offsets from LabelArea+0 to Labels (for each Animation Block)
      ...  ..   Label Area (ASCII Strings, terminated by 00h)

The LabelArea starts at LBAL+8+NumLabels*4 (whereas, NumLabels is found in KNBA chunk).
TXEU Chunk
Caution: Not 4-byte aligned (the preceeding LBAL chunk can have odd size).

      000h 4    Chunk ID "TXEU" (aka UEXT backwards, Whatever Extension or so?)
      004h 4    Chunk Size (0Ch)
      008h 4    Unknown (usually 0) (reportedly 0 or 1)

     __________________________ Nitro OBJ Metatile Cells __________________________

Header

      000h 4    Chunk ID "RECN" (aka NCER backwards, Nitro Cell Resource)
      004h 2    Byte Order    (FEFFh)
      006h 2    Version       (0100h)
      008h 4    Total Filesize
      00Ch 2    Offset to "KBEC" Chunk, aka Size of "RECN" Chunk (0010h)
      00Eh 2    Total number of following Chunks (1=KBEC, or 3=KBEC+LBAL+TXEU)

KBEC Chunk

      000h 4    Chunk ID "KBEC" (aka CEBK backwards, Cell Bank)
      004h 4    Chunk Size (always padded to 4-byte boundary if LABL chunk follows)
      008h 2    Number of Metatiles
      00Ah 2    Metatiles Entry Size (0=Normal 8 bytes, 1=Extended 16 bytes)
                  (DSi Launcher ..layout\cmn\launcher_u\.. uses 16-byte size)
      00Ch 4    Offset from KBEC+8 to Metatile Table? (18h)
      010h 4    Boundary Size (?)       (but is ZERO in layout\cmn\launcher_u\)
                   "Specifies the area in which the image can be drawn,
                   multiplied by 64, ie. 2 means that the area is 128x128 pixels."
      014h 0Ch  Zero
      020h ..   Metatile Table (8 bytes each) (or 16 bytes)
      ...  ..   OBJ Attribute Table (6-bytes each)

Metatile Table entries are (8-byte or 16-byte):

      000h 2    Number of OBJs
      002h 2    Unknown
      004h 4    OBJ Data Offset (from begin of OBJ Attr Table)
     (008h 2)   Unknown (can be 02h,10h,48h,74h)
     (00Ah 2)   Unknown (can be 08h)
     (00Ch 2)   Unknown (can be FFA0h..FFF0h) ;\maybe extra coordinate offsets?
     (00Eh 2)   Unknown (can be FFF0h..FFF9h) ;/

OBJ Attribute Table...

      starts at Number of Cells * 8 | each cell is made up of 6 bytes)

The 6-byte OBJ Attributes seem to be in normal OAM format, containing the coordinates, tile number, tile size, and other flags (however, the coordinates contain signed values; ie. one needs to add the current OBJ position to those values). For details on the OBJ Attributes, see:
LCD OBJ - OAM Attributes
LBAL and TEXU Chunks (if any)
Same as in Animation files (see there). In fact, the content seems to be SAME as the corresponding Animation file (for pairs of filename.NANR and filename.NCER), and the number of labels must be obtained from the NANR file's KNBA chunk (as such, it's rather useless to have LBAL in NCER files, except perhaps for error checking that the correct file pair was loaded).
Note: DSi Launcher layout\cmn\logodemo.szs has KBEC Chunk Size 2B6h (although the filesize is padded as if it were 2B8h bytes) (the file has no LBAL chunk, so it's unclear if/how it were aligned if present).

     ____________________________ Nitro Unknown Files  ____________________________

DSi Deep Psyche has two extra file types:

      .NMAR file (with "RAMN" header ID, and "KNBA"+"LBAL" chunks)
      .NMCR file (with "RCMN" header ID, and "KBCM" chunk)

The purpose is unknown, but they are probably also animating something...

      OBJ with 16bit x/y (instead 9bit/8bit)?
      OBJ with fractional x/y-stepping (moving/motion)?
      OBJ rotation/scaling?
      BG scroll offsets?
      BG tile replacement?

Going by the filename (a01_obj01.NMAR) they seem to be OBJ related. Labels include things like "a01_upNN" and "a01_windowNN".
The chunks seem to resemble those in RNAN/RECN files (Animation+Cells). Except, the KBCM has 8-byte entries (unlike the 6-byte ones in KBEC):

      000h 2    Unknown (000xh..007Ah, maybe time or so?)
      002h 2    Unknown (signed 16bit?)
      004h 2    Unknown (signed 16bit?)
      006h 2    Unknown (0x21h, with x=0..8)

     _________________________ Nitro More Unknown Files  __________________________

Some 2D folders contain more unknown files (eg. DSi Camera "rom:layout\cmn\fusion_camera.szs"):
JNBL (whatever, with .bnbl extension)

      000h 4     ID "JNBL"
      004h 2     Zero
      006h 2     Number of 6-byte entries (01h or more)
      008h N*6   Unknown

JNCL (whatever, with .bncl extension)

      000h 4     ID "JNCL"
      004h 2     Zero (0000h)
      006h 2     Number of 8-byte entries (01h or more)
      008h N*8   Unknown (eg. 80h,10h,C0h,20h,00h,00h,00h,00h)

JNLL (whatever, with .bnll extension)

      000h 4     ID "JNLL"
      004h 2     Zero (0000h)
      006h 2     Number of 16-byte entries (01h or more)
      008h N*16  Unknown (eg. 80h,50h,60h,10h,7Ch,29h,FFh,FDh,0Dh,19h,0,0,0,0,0,0)

BNGL (whatever, with .bngl extension)

      000h 4   ID "BNGL"   ;this same as file extension (not JNGL)
      004h 2   Zero (0000h)
      006h 2   Number of ?-byte entries (01h or more)
      008h 2   Unknown (can be 02h,04h,06h,0Ah)
      00Ah 2   Number of ?-byte other entries maybe (01h or more)
      ...
      ...      Entries?
      ...      Other Entries?
      ...      Maybe More Other Entries?

Filesize can range from 18h bytes to 24Ah bytes (or maybe yet smaller/biggger).

     ______________________________ .ntft and .ntfp _______________________________

.ntft file
Probably texture data (maybe for use as extra 2D layer), size is usually/always a power of 2 (ranging from 80h bytes to at least 64Kbytes (or even 512Kbytes?). Color depth can be 16bit or 8bit (and maybe less). Files with less than 16bit are bundled with a .ntfp palette file.
.ntfp file
Probably texture palette, with 16bit color numbers. The files can be quite small (eg. only 6 or 8 bytes).

     ______________________________ .wmif and .wmpf _______________________________

DSi Sudoku rom:\Textures\ has "Wild Magic" .wmif and .wmpf (image+palette) files.
.wmif file

      000h 1Bh  ID "Wild Magic Image File 3.00",00h
      01Bh 4    Palette Filename Length (eg. 0Dh)
      01Fh LEN  Palette Filename        (eg. "BG_Board.wmpf")
      ...  4    Texture Format (6=4bpp, 7=8bpp)
      ...  4    Texture Width in pixels
      ...  4    Texture Height in pixels
      ...  ..   Texture data

.wmpf file

      000h 1Dh  ID "Wild Magic Palette File 1.00",00h
      01Dh 4    Zero?
      021h 4    Number of Colors
      025h ..   Colors, 16bit (0000h..7FFFh)

DS Files - 3D Video (mostly unknown)

Some Nintendo DS games are use the following set of Nitro Studio files for 3D Models:

      .NSBMD (ID="BMD0") - Nitro Polygon Model
      .NSBTX (ID="BTX0") - Nitro Texture and Palette
      .NSBCA (ID="BCA0") - Nitro Skeletal Character Animation
      .NSBTP (ID="BTP0") - Nitro Texture Pattern-swap Animation
      .NSBTA (ID="BTA0") - Nitro Texture UV-change Animation (aka texcoords?)
      .NSBMA (ID="BMA0") - Nitro Material-swap Animation (whut?)
      .NSBVA (ID="BVA0") - Nitro Vis... Animation?

Unknown which games are actually using that format... probably some mid-NDS-era titles from Nintendo (early NDS launch titles didn't use it, 3rd party NDS titles tend to use custom formats, and later DSi mini-games don't support 3D graphics at all).
Below is an attempt to clean up rather confusing specs (hopefully appearing less confusing, but probably containing some misinterpretations in cases where the original specs where too confusing; the much-too-much confusing parts are left intact and marked as unknown what they might be meant to mean).
DS Files - 3D Video BMD0 (Model Data)
DS Files - 3D Video BTX0 (Texture)
DS Files - 3D Video BCA0 (Character Skeletal Animation)
DS Files - 3D Video BTP0/BTA0/BMA0/NVA0 (Unknown Animations)
Note: The format resembles the later CGFX format used on 3DS.
Dict "typedef struct Header" - alike "DICT" on 3DS?

      000h 1   Dummy 0
      001h 1   Amount of "objects"
      002h 2   Size of this Header (that is... what? header up to names?)
      ...  ..  Probably followed by the three sections mentioned below...?

Unknown Section ;maybe Name lookup (Patricia Tree or Hash or so)?

     Sub-Header
      000h 2   Size of this Sub-Header, always = 8
      002h 2   Size of this Unknown Section (that is... N*?+8 ...?)
      004h 4   Constant = 0000017Fh
     Unknown Data (repeats * Amount of "objects")
      008h 4   Unknown     ;1st object
      00Ch 4   ...         ;2nd object? or 2nd word of 1st object?
      etc                  ;etc?

Data Info Section

     The Data content depends on what the Dict is used for. It can contain
     4 or 8 bytes of data stored directly, or it can contain a 2 or 4 byte
     offset to larger data).
      000h 2      Size of each Data entry (siz) (usually 4 or 8)
      002h 2      Size of this Data Info Section (that is... N*siz+8 ...?)
      004h N*siz  Data (siz bytes, for each "object")

Name Section

      000h N*16   Name String (in ASCII maybe?) (for each "object")

DS Files - 3D Video BMD0 (Model Data)

Aka NSBMD
BMD0 Header

      000h 4     ID "BMD0" (Basic Model Data)
      004h 2     Byte Order (FEFFh)
      006h 2     Version? (reportedly 1 or 2, in whatever audio/video files?)
      008h 4     Total Filesize
      00Ch 2     Size of this structure (always 16 ???)
      00Eh 2     Number of chunks (1=MDL0 or 2=MDL0+TEX0)
      010h 4     Offset to MDL0 Chunk
      014h 4     Offset to TEX0 Chunk (if any?) (otherwise TEX0 is in NSBTX file)

MDL0 Chunk

      000h 4     Chunk ID "MDL0" (Model Block)
      004h 4     Chunk Size
      008h ..    Model Dict (with 32bit offsets to Models from "Block_MDL0")
      ...  ..    Models

Model (all offsets are relative to this Model section)

      000h 4    Size of Model (including these 4 bytes)
      004h 4    Offset of Additional Model Data          ;whut?
      008h 4    Offset of Texture & Palette Offset       ;?
      00Ch 4    Offset of Display List Start             ;?
      010h 4    Offset of Display List End               ;?
      014h 1    Unknown
      015h 1    Unknown
      016h 1    Unknown
      017h 1    Amount of Objects           ;\
      018h 1    Amount of Materials         ; what for?
      019h 1    Amount of Polygons          ; is that just some usage comment,
      020h 4    Unknown                     ; for statistical purposes?
      024h 2    Amount of Vertices          ;
      026h 2    Amount of Surfaces          ;
      028h 2    Amount of Triangles         ;
      02Ah 2    Amount of Quads             ;/
      02Ch 2    Bounding box X      (signed fixed point 1.3.12)
      02Eh 2    Bounding box Y      (signed fixed point 1.3.12)
      030h 2    Bounding box Z      (signed fixed point 1.3.12)
      032h 2    Bounding box Width  (signed fixed point 1.3.12)
      034h 2    Bounding box Height (signed fixed point 1.3.12)
      036h 2    Bounding box Depth  (signed fixed point 1.3.12)
      038h 4    Runtime use data
      03Ch 4    Runtime use data
      040h ..   Polygonal Object Dict (with 32bit offsets to Objects from
                                                     "this Object Header")
      ...  ..   Object Definitions

Object Definition (repeats * Amount of objects)

     In each definition:
      000h 1   Transform Flag byte
      001h 1   Unknown
      002h 1   Unknown
      003h 1   Unknown
      ...  4   Translation X (s32 signed fixed point 1.3.12)  ;\
      ...  4   Translation Y (s32 signed fixed point 1.3.12)  ; when Flags.0=0
      ...  4   Translation Z (s32 signed fixed point 1.3.12)  ;/
      ...  4   Scale X       (s32 signed fixed point 1.3.12)  ;\
      ...  4   Scale Y       (s32 signed fixed point 1.3.12)  ; when Flags.2=0
      ...  4   Scale Z       (s32 signed fixed point 1.3.12)  ;/
      ...  4   Rotation A    (s32 whatever, fixed point?)     ;\
      ...  4   Rotation B    (s32 whatever, fixed point?)     ; when Flags.1=0
      ...  4   Rotation C    (s32 whatever, fixed point?)     ; and Flags.3=0
      ...  4   Rotation D    (s32 whatever, fixed point?)     ;/
      ...  2   Pivot Rotation A (signed fixed point 1.3.12)   ;\when Flags.1=0
      ...  2   Pivot Rotation B (signed fixed point 1.3.12)   ;/and Flags.3=1

Unknown how above "1.3.12" can be "s32" (maybe actually 17.3.12 ?)
The Transform Flag bits are:

      0    Translation   (0=Yes, 1=No)
      1    Rotation      (0=Yes, 1=No)
      2    Scaling       (0=Yes, 1=No)
      3    Rotation Type (0=Rotate A,B,C,D, 1=Pivot A,B)
      4-7  Pivot Matrix  (0..8, see below) (used when bit1=0 and bit3=1)

Pivot matrix type (0..8):

      0:  | 1  0  0|  1:  | 0  1  0|  2:  | 0  0  1|
          | 0  A  B|      | A  0  B|      | A  B  0|
          | 0  B -A|      | B  0 -A|      | B -A  0|

      3:  | 0  A  B|  4:  | A  0  B|  5:  | A  B  0|
          | 1  0  0|      | 0  1  0|      | 0  0  1|
          | 0  B -A|      | B  0 -A|      | B -A  0|

      6:  | 0  A  B|  7:  | A  0  B|  8:  | A  B  0|
          | 0  B -A|      | B  0 -A|      | B -A  0|
          | 1  0  0|      | 0  1  0|      | 0  0  1|

Non-Pivot does probably also use some kind of matrix made of A,B,C,D...?
Bone/Skeleton Section <-- what is that? does it follow after above?

      000h ..    Definitions

Each definition consists of 1 Command Byte + Parameters. Each Parameter is 1 byte.

      Cmd  Params  Description
      06h  3       params: Object ID, Parent ID, dummy 0
      26h  4       params: Object ID, Parent ID, dummy 0, Stack ID
      46h  4       params: Object ID, Parent ID, dummy 0, Stack ID
      66h  5       params: Object ID, Parent ID, dummy 0, Stack ID, Restore ID

      00h  0       NOP (empty command)
      01h  0       End of Bone/Skeleton Section
      02h  2       params: Node ID, Visibility
      03h  1       Set Polygon Stack ID?
      04h  3       params: Material ID, 05h, Polygon ID
      05h  1       ??
      06h  3       params: Object ID, Parent ID, Dummy 0
      07h  1       ??
      08h  1       ??
      09h  8       ??

      0Bh  0       BEGIN (indicate begin of Polygon/Material pairing)
      2Bh  0       END (indicate end of Polygon/Material pairing)

      These are Material/Polygon pairing commands, 4 bytes.
      The lower nibble of 2nd Parameter must be 5.
      04h  3       Material ID, 05, Polygon ID
      24h  3       ...
      44h  3       ...

Texture & Palette Offset <-- what is that, addressed from Model [008h] ?

        000h 2   Offset of Texture Section (relative to Texture & Palette Offset)
        002h 2   Offset of Palette Section (relative to Texture & Palette Offset)

Material Section <-- WHAT is THAT ??? and WHERE is it ???

        Dict struct Header;// Material Header: one Header object for each material
        {// The 'Data' for this Header is like so:
          000h 4   Offset of Material Definition, relative to the start of
                     this Material Section
        }

        Texture Section
          Dict struct Header;// Texture Header: one Header object for each texture
          {// The u32 'Data' for this Header is like so:
              000h 2   Offset of Matching Data (relative to Texture & Palette
                         Offset)
              002h 2   Amount of associated Materials (a texture can be in more
                         than one material)
          }

        Palette Section
          Dict struct Header;// Palette Header: one Header object for each palette
          {// The u32 'Data' for this Header is like so:
              000h 2   Offset of Matching Data (relative to Texture & Palette
                         Offset)
              002h 2   Amount of associated Materials (a palette can be in more
                         than one material)
          }

        Material Definition (repeats * Amount of Materials)
          ;// Usually 48 bytes for each material

Polygon Section

        Dict struct Header;// Polygon Header: one Header object for each material
        {// The 'Data' for this Header is like so:
            000h 4   Offset of Polygon Definition, relative to the start of this
                       Polygon Section
        }

        Polygon Definition (repeats * Amount of Polygons) (10h-bytes each)
          000h 4   Unknown
          004h 4   Unknown
          008h 4   Offset of Display List, relative to Polygon Definition
          00Ch 4   Size of Display List

        Display List
          // The Display List is actually packed geometry command.
          // See the DStek specification for more information:
          // http://www.akkit.org/info/gbatek.htm#ds3dvideo    ;uh?

TEX0 Chunk
Reportedly same as in BTX0 files, see there for details.

DS Files - 3D Video BTX0 (Texture)

The NSBTX file format stores texture image and palette information.
The "TEX0" Block can be found in certain NSBMD files, not just in NSBTX files.
BTX0 Header

      000h 4     ID "BTX0" (Basic Texture)
      004h 2     Byte Order (FEFFh)
      006h 2     Version? (reportedly 1 or 2, in whatever audio/video files?)
      008h 4     Total Filesize
      00Ch 2     Size of this structure (always 16 ???)
      00Eh 2     Number of chunks (1=TEX0)
      010h 4     Offset to TEX0 Chunk

TEX0 Chunk

      000h 4     Chunk ID "TEX0" (Texture Block)
      004h 4     Chunk Size
      008h 4     Padding (0)
      00Ch 2     Texture Data Size (bitshift << 3)             ;\
      00Eh 2     Texture Dict Offset (03Ch)                    ; Texture
      010h 4     Padding (0)                                   ;
      014h 4     Texture Data Offset                           ;/
      018h 4     Padding (0)
      01Ch 2     Compressed Texture Data Size (bitshift << 3)  ;\<-- Size
      01Eh 2     Compressed Texture Dict? Offset (03Ch, again?); <-- Dict?
      020h 4     Padding (0)                                   ;
      024h 4     Compressed Texture Data Offset                ; <-- Data
      028h 4     Compressed Texture Info Data Offset           ;/<-- InfoData?
      02Ch 4     Padding (0)
      030h 4     Palette Data Size (bitshift << 3)             ;\
      034h 4     Palette Dict Offset                           ; Palette
      038h 4     Palette Data Offset                           ;/
      03Ch ..    Texture Dict (with 8-byte entries, see below)
      N/A? ?     Compressed Texture Dict? (maybe here? with whatever entries?)
      ...  ..    Palette Dict (with 4-byte entries, see below)
      ...  ..    Texture Data Section     (unknown... maybe bitmap/pixels?)
      ...  ..    Compressed Texture Data Section            (unknown...)
      ...  ..    Compressed Texture Info Data Section       (unknown...)
      ...  ..    Palette Data Section     (unknown... maybe palette/colors?)

Format of 8-byte entries in Texture Dict:

      000h 2     Texture Offset (bitshift << 3), relative to the start
                                                 of Texture Data
      002h 2     Parameters   ;<-- probably "upper 16bit of TEXIMAGE_PARAM" ?
                    The format is, using knock-out description:
                    bit:  15..............0
                       0 b --CFFFHHHWWW-----   <-- uh, is that "0 b" and 17bits???
                    where:
                      C = Palette ID
                      F = Format (0-7)
                      H = Height (8 << Height)
                      W = Width (8 << Width)
                    To Calculate the Data Size of a Texture:
                    Bit Depth = Format: <0, 8, 2, 4, 8, 2, 8, 16>
                    Width * Height * BitDepth / 8
      004h 1     Width (should match W << 3)
      005h 1     Unknown (is 00h or 80h)
      006h 1     Height? (can be 0, 1, 2, 4, 8)
      007h 1     Unknown (is 80h)

Compressed Texture Dict? (maybe here? with whatever entries?)
Compressed Texture might have a Dict, too? with whatever entries?
Format of 4-byte entries in Palette Dict:

      000h   2   u16 ;// (bitshift << 3) Palette Offset, relative to the start
                                                         of Palette Data
      000h?  2   u16 ;// Unknown (is 0 or 1)

Texture Data Section:
Compressed Texture Data Section:
Compressed Texture Info Data Section:
Palette Data Section:

      Unknown

DS Files - 3D Video BCA0 (Character Skeletal Animation)

The NSBCA file format stores character skeletal/bone/joint animation data.
BCA0 Header

      000h 4     ID "BCA0" (Basic Character Animation)
      004h 2     Byte Order (FEFFh)
      006h 2     Version? (reportedly 1 or 2, in whatever audio/video files?)
      008h 4     Total Filesize
      00Ch 2     Size of this structure (always 16 ???)
      00Eh 2     Number of chunks (1=JNT0)
      010h 4     Offset to JNT0 Chunk

JNT0 Chunk

      000h 4     Chunk ID "JNT0" (Joint Block)
      004h 4     Chunk Size
      008h ..    Joint Dict (with 32bit offsets to Joints, from "Block_JNT0")

Joints
Reportedly Joints "repeats * Amount of Objects"
Uh, with Amount of Objects stored inside of below?
Maybe rather meant to mean that Joints exist for each Model (not Object)?

      000h 4    ID 'J.AC' (Joint Animation Content ?)
      004h 2    Amount of Frames
      006h 2    Amount of Objects (should be same as in BMD0 file)
      008h 4    Unknown
      00Ch 4    Offset to Unknown1 chunk. Relative to start of this block.
      010h 4    Offset to Unknown2 chunk. Relative to start of this block.
      014h 4    Object Info Offset (repeats * Amount of Objects), relative
                   to start of this Joint Section.
                   uh, is above meant to be Offset to first Object?
                   or an array with Offsets to all Objects?
      ...  ..   Object Info, for each object (supposedly here?)
      ...  ..   Unknown1
      ...  ..   Unknown2
      ...  ..   Reportedly "end of file" (is that possible with multiple joints?)

Object Info - Repeats * Number of Objects

        000h 2   Flag - Indicates what sort of Transformations are applied.
                  Bit0  -  Unused?
                  Bit1  T  Translate  (0=Yes; data follows, 1=No?)
                  Bit2  -  Unused?
                  Bit3  X  Affects how WHICH data is stored but dunno WHERE?
                  Bit4  Y  Affects how WHICH data is stored but dunno WHERE?
                  Bit5  Z  Affects how WHICH data is stored but dunno WHERE?
                  Bit6  R  Rotate     (0=Yes; data follows, 1=No?)
                  Bit7  -  Unused?
                  Bit8  r  Affects how WHICH data is stored but dunno WHERE?
                  Bit9  S  Scale      (0=Yes; data follows, 1=No?)
                  Bit10 -  Unused?
                  Bit11 x  Affects how WHICH data is stored but dunno WHERE?
                  Bit12 y  Affects how WHICH data is stored but dunno WHERE?
                  Bit13 z  Affects how WHICH data is stored but dunno WHERE?
                  Bit14 -  Unused?
                  Bit15 -  Unused?
        002h 1   Unknown   (reportedly u32, 1-byte wide ???)
        003h 1   ID Number (reportedly u32, 1-byte wide ???)
      *** (Unknown what below crap means, it does probably refer to multiple
      *** entries, for Translate, Rotate, and Scale; and possibly even to
      *** multiple sub-entries for X,Y,Z or whatever?)
      Transformation Info (Translation XYZ, Rotation, Scale XYZ) when WHAT=1
        000h 4   Actual value (uh, WHICH value?)
      Transformation Info (Translation XYZ, Rotation, Scale XYZ) when WHAT=0
        000h 2   Unknown - typically 0000h
        002h 2   Unknown
        004h 4   Offset to data. Relative to "(Object Info Offset + 4)".

Unknown1 - Repeats until Unknown2

      000h 2   Reportedly 36, 32 & 0.
      002h 2   Unknown (reportedly signed)
      004h 2   Unknown (reportedly signed)

Unknown2 - Repeats until end of file

      "All transformation offsets point somewhere in this section.
      It's clearly broken up into parts (Translation, Rotation & Scale),
      however I'm not totally sure how data is store in here yet."

DS Files - 3D Video BTP0/BTA0/BMA0/NVA0 (Unknown Animations)

     ____________ DS Files - 3D Video BTP0 (Texture Pattern Animation) ____________

BTP0 Header

      000h 4     ID "BTP0" (Texture Pattern Animation)
      ...  ..    XXX

PAT0 Chunk

      000h 4     Chunk ID "PAT0" (Pattern Block)
      004h 4     Chunk Size
      ...  ..    Unknown

     ________________ DS Files - 3D Video BTA0 (Texture Animation) ________________

BTA0 Header

      000h 4     ID "BTA0" (Texture Animation)
      ...  ..    XXX

SRT0 Chunk

      000h 4     Chunk ID "SRT0"   (maybe short for Scale/Rotate/Translate?)
      004h 4     Chunk Size
      ...  ..    Unknown

     _______________ DS Files - 3D Video BMA0 (Material Animation) ________________

BMA0 Header

      000h 4     ID "BMA0" (Material Animation)
      ...  ..    XXX

MAT0 Chunk

      000h 4     Chunk ID "MAT0" (Material Block)
      004h 4     Chunk Size
      ...  ..    Unknown

     ____________________ DS Files - 3D Video BVA0 (Unknown?) _____________________

BVA0 Header

      000h 4     ID "BVA0" (whatever Vis... Animation?)
      ...  ..    XXX

VIS0 Chunk

      000h 4     Chunk ID "VIS0" (Visibility...?)
      004h 4     Chunk Size
      ...  ..    Unknown

DS Files - Sound (SDAT etc.)

Sound data is often stored in a SDAT file (with SSEQ, SSAR, SBNK, SWAR, STRM blocks inside of the SDAT files). Samples can be stored in SWAV files (or be contained in SWAR's inside of SDAT files).
DS Sound Files - SDAT (Sound Data Archive)
DS Sound Files - SSEQ (Sound Sequence)
DS Sound Files - SSAR (Sound Sequence Archive)
DS Sound Files - SBNK (Sound Bank)
DS Sound Files - SWAR (Sound Wave Archive)
DS Sound Files - SWAV (Sound Wave Data)
DS Sound Files - STRM (Sound Wave Stream)
Thanks: http://www.feshrine.net/hacking/doc/nds-sdat.php - 2007 by kiwi.ds

DS 3D Video

DS 3D Overview
DS 3D I/O Map
DS 3D Display Control
DS 3D Geometry Commands
DS 3D Matrix Load/Multiply
DS 3D Matrix Types
DS 3D Matrix Stack
DS 3D Matrix Examples (Projection)
DS 3D Matrix Examples (Rotate/Scale/Translate)
DS 3D Matrix Examples (Maths Basics)
DS 3D Polygon Attributes
DS 3D Polygon Definitions by Vertices
DS 3D Polygon Light Parameters
DS 3D Shadow Polygons
DS 3D Texture Attributes
DS 3D Texture Formats
DS 3D Texture Coordinates
DS 3D Texture Blending
DS 3D Toon, Edge, Fog, Alpha-Blending, Anti-Aliasing
DS 3D Status
DS 3D Tests
DS 3D Rear-Plane
DS 3D Final 2D Output
3D is more or less (about 92%) understood and described.

DS 3D Overview

The NDS 3D hardware consists of a Geometry Engine, and a Rendering Engine.
Geometry Engine (Precalculate coordinates & assign polygon attributes)
Geometry commands can be sent via Ports 4000440h and up (or alternately, written directly to Port 4000400h).
The commands include matrix and vector multiplications, the purpose is to rotate/scale/translate coordinates (vertices), the resulting coordinates are stored in Vertex RAM.
Moreover, it allows to assign attributes to the polygons and vertices, that includes vertex colors (or automatically calculated light colors), texture attributes, number of vertices per polygon (three or four), and a number of flags, these attributes are stored in Polygon RAM. Polygon RAM also contains pointers to the corresponding vertices in Vertex RAM.
Swap Buffers (Pass data from the Geometry Engine to the Rendering Engine)
The hardware includes two sets of Vertex/Polygon RAM, one used by the Geometry Engine, one by the Rendering Engine. The SwapBuffers command simply exchanges these buffers (so the new Geometry Data is passed to the Rendering Engine) (and the old buffer is emptied, so the Geometry engine can write new data to it). Additionally, the two parameter bits from the <previous> SwapBuffers command are copied to the Geometry Engine.
Data that is NOT swapped: SwapBuffers obviously can't swap Texture memory (so software must take care that Texture memory is kept mapped throughout rendering). Moreover, the rendering control registers (ports 4000060h, and 4000330h..40003BFh) are not swapped (so that values must be kept intact during rendering, too).
Rendering Engine (Display Output)
The Rendering Engine draws the various Polygons, and outputs them as BG0 layer to the 2D Video controller (which may then output them to the screen, or to the video capture unit). The Rendering part is done automatically by hardware, so the software has little influence on it.
Rendering is done scanline-by-scanline, so there's only a limited number of clock cycles per scanline, which is limiting the maximum number of polygons per scanline. However, due to the 48-line cache (see below), some scanlines are allowed to exceed that maximum.
Rendering starts 48 lines in advance (while still in the Vblank period) (and does then continue throughout the whole display period), the rendered data is written to a small cache that can hold up to 48 scanlines.
Scanline Cache vs Framebuffer
Note: There's only the 48-line cache (not a full 192-line framebuffer to store the whole rendered image). That is perfectly reasonable since animated data is normally drawn only once (so there would be no need to store it). That, assuming that the Geometry Engine presents new data every frame (otherwise, if the Geometry software is too slow, or if the image isn't animated, then the hardware is automatically rendering the same image again, and again).

DS 3D I/O Map

3D I/O Map

      Address  Siz Name            Expl.
      Rendering Engine (per Frame settings)
      4000060h 2   DISP3DCNT       3D Display Control Register (R/W)
      4000320h 1   RDLINES_COUNT   Rendered Line Count Register (R)
      4000330h 10h EDGE_COLOR      Edge Colors 0..7 (W)
      4000340h 1   ALPHA_TEST_REF  Alpha-Test Comparision Value (W)
      4000350h 4   CLEAR_COLOR     Clear Color Attribute Register (W)
      4000354h 2   CLEAR_DEPTH     Clear Depth Register (W)
      4000356h 2   CLRIMAGE_OFFSET Rear-plane Bitmap Scroll Offsets (W)
      4000358h 4   FOG_COLOR       Fog Color (W)
      400035Ch 2   FOG_OFFSET      Fog Depth Offset (W)
      4000360h 20h FOG_TABLE       Fog Density Table, 32 entries (W)
      4000380h 40h TOON_TABLE      Toon Table, 32 colors (W)
      Geometry Engine (per Polygon/Vertex settings)
      4000400h 40h GXFIFO          Geometry Command FIFO (W)
      4000440h ... ...             Geometry Command Ports (see below)
      4000600h 4   GXSTAT          Geometry Engine Status Register (R and R/W)
      4000604h 4   RAM_COUNT       Polygon List & Vertex RAM Count Register (R)
      4000610h 2   DISP_1DOT_DEPTH 1-Dot Polygon Display Boundary Depth (W)
      4000620h 10h POS_RESULT      Position Test Results (R)
      4000630h 6   VEC_RESULT      Vector Test Results (R)
      4000640h 40h CLIPMTX_RESULT  Read Current Clip Coordinates Matrix (R)
      4000680h 24h VECMTX_RESULT   Read Current Directional Vector Matrix (R)

Geometry Commands (can be invoked by Port Address, or by Command ID)
Table shows Port Address, Command ID, Number of Parameters, and Clock Cycles.

      Address  Cmd Pa.Cy.
      N/A      00h -  -   NOP - No Operation (for padding packed GXFIFO commands)
      4000440h 10h 1  1   MTX_MODE - Set Matrix Mode (W)
      4000444h 11h -  17  MTX_PUSH - Push Current Matrix on Stack (W)
      4000448h 12h 1  36  MTX_POP - Pop Current Matrix from Stack (W)
      400044Ch 13h 1  17  MTX_STORE - Store Current Matrix on Stack (W)
      4000450h 14h 1  36  MTX_RESTORE - Restore Current Matrix from Stack (W)
      4000454h 15h -  19  MTX_IDENTITY - Load Unit Matrix to Current Matrix (W)
      4000458h 16h 16 34  MTX_LOAD_4x4 - Load 4x4 Matrix to Current Matrix (W)
      400045Ch 17h 12 30  MTX_LOAD_4x3 - Load 4x3 Matrix to Current Matrix (W)
      4000460h 18h 16 35* MTX_MULT_4x4 - Multiply Current Matrix by 4x4 Matrix (W)
      4000464h 19h 12 31* MTX_MULT_4x3 - Multiply Current Matrix by 4x3 Matrix (W)
      4000468h 1Ah 9  28* MTX_MULT_3x3 - Multiply Current Matrix by 3x3 Matrix (W)
      400046Ch 1Bh 3  22  MTX_SCALE - Multiply Current Matrix by Scale Matrix (W)
      4000470h 1Ch 3  22* MTX_TRANS - Mult. Curr. Matrix by Translation Matrix (W)
      4000480h 20h 1  1   COLOR - Directly Set Vertex Color (W)
      4000484h 21h 1  9*  NORMAL - Set Normal Vector (W)
      4000488h 22h 1  1   TEXCOORD - Set Texture Coordinates (W)
      400048Ch 23h 2  9   VTX_16 - Set Vertex XYZ Coordinates (W)
      4000490h 24h 1  8   VTX_10 - Set Vertex XYZ Coordinates (W)
      4000494h 25h 1  8   VTX_XY - Set Vertex XY Coordinates (W)
      4000498h 26h 1  8   VTX_XZ - Set Vertex XZ Coordinates (W)
      400049Ch 27h 1  8   VTX_YZ - Set Vertex YZ Coordinates (W)
      40004A0h 28h 1  8   VTX_DIFF - Set Relative Vertex Coordinates (W)
      40004A4h 29h 1  1   POLYGON_ATTR - Set Polygon Attributes (W)
      40004A8h 2Ah 1  1   TEXIMAGE_PARAM - Set Texture Parameters (W)
      40004ACh 2Bh 1  1   PLTT_BASE - Set Texture Palette Base Address (W)
      40004C0h 30h 1  4   DIF_AMB - MaterialColor0 - Diffuse/Ambient Reflect. (W)
      40004C4h 31h 1  4   SPE_EMI - MaterialColor1 - Specular Ref. & Emission (W)
      40004C8h 32h 1  6   LIGHT_VECTOR - Set Light's Directional Vector (W)
      40004CCh 33h 1  1   LIGHT_COLOR - Set Light Color (W)
      40004D0h 34h 32 32  SHININESS - Specular Reflection Shininess Table (W)
      4000500h 40h 1  1   BEGIN_VTXS - Start of Vertex List (W)
      4000504h 41h -  1   END_VTXS - End of Vertex List (W)
      4000540h 50h 1  392 SWAP_BUFFERS - Swap Rendering Engine Buffer (W)
      4000580h 60h 1  1   VIEWPORT - Set Viewport (W)
      40005C0h 70h 3  103 BOX_TEST - Test if Cuboid Sits inside View Volume (W)
      40005C4h 71h 2  9   POS_TEST - Set Position Coordinates for Test (W)
      40005C8h 72h 1  5   VEC_TEST - Set Directional Vector for Test (W)

All cycle timings are counted in 33.51MHz units. NORMAL commands takes 9..12 cycles, depending on the number of enabled lights in PolyAttr (Huh, 9..12 (four timings) cycles for 0..4 (five settings) lights?) Total execution time of SwapBuffers is Duration until VBlank, plus 392 cycles.
In MTX_MODE=2 (Simultanous Set), MTX_MULT/TRANS take additional 30 cycles.

DS 3D Display Control

4000060h - DISP3DCNT - 3D Display Control Register (R/W)

      0     Texture Mapping      (0=Disable, 1=Enable)
      1     PolygonAttr Shading  (0=Toon Shading, 1=Highlight Shading)
      2     Alpha-Test           (0=Disable, 1=Enable) (see ALPHA_TEST_REF)
      3     Alpha-Blending       (0=Disable, 1=Enable) (see various Alpha values)
      4     Anti-Aliasing        (0=Disable, 1=Enable)
      5     Edge-Marking         (0=Disable, 1=Enable) (see EDGE_COLOR)
      6     Fog Color/Alpha Mode (0=Alpha and Color, 1=Only Alpha) (see FOG_COLOR)
      7     Fog Master Enable    (0=Disable, 1=Enable)
      8-11  Fog Depth Shift      (FOG_STEP=400h shr FOG_SHIFT) (see FOG_OFFSET)
      12    Color Buffer RDLINES Underflow (0=None, 1=Underflow/Acknowledge)
      13    Polygon/Vertex RAM Overflow    (0=None, 1=Overflow/Acknowledge)
      14    Rear-Plane Mode                (0=Blank, 1=Bitmap)
      15-31 Not used

4000540h - Cmd 50h - SWAP_BUFFERS - Swap Rendering Engine Buffer (W)
SwapBuffers exchanges the two sets of Polygon/Vertex RAM buffers, that is, the newly defined polygons/vertices are passed to the rendering engine (and will be displayed in following frame(s)). The other buffer is emptied, and passed to the Geometry Engine (to be filled with new polygons/vertices by Geometry Commands).

      0     Translucent polygon Y-sorting (0=Auto-sort, 1=Manual-sort)
      1     Depth Buffering  (0=With Z-value, 1=With W-value)
            (mode 1 does not function properly with orthogonal projections)
      2-31  Not used

SwapBuffers isn't executed until next VBlank (Scanline 192) (the Geometry Engine is halted for that duration). SwapBuffers should not be issued within Begin/End. The two parameter bits of the SwapBuffers command are used for the following gxcommands (ie. not for the old gxcommands prior to SwapBuffers).
SwapBuffers does lock-up the 3D hardware if an incomplete polygon list has been defined (eg. a triangle with only 2 vertices). On lock-up, only 2D video is kept working, any wait-loops for GXSTAT.27 will hang the program. Once lock-up has occured, there seems to be no way to recover by software, not by sending the missing veric(es), and not even by pulsing POWCNT1.Bit2-3.
4000580h - Cmd 60h - VIEWPORT - Set Viewport (W)

      0-7   Screen/BG0 Coordinate X1 (0..255) (For Fullscreen: 0=Left-most)
      8-15  Screen/BG0 Coordinate Y1 (0..191) (For Fullscreen: 0=Bottom-most)
      16-23 Screen/BG0 Coordinate X2 (0..255) (For Fullscreen: 255=Right-most)
      24-31 Screen/BG0 Coordinate Y2 (0..191) (For Fullscreen: 191=Top-most)

Coordinate 0,0 is the lower-left (unlike for 2D where it'd be upper-left).
The 3D view-volume (size as defined by the Projection Matrix) is automatically scaled to match into the Viewport area. Although polygon vertices are clipped to the view-volume, some vertices may still exceed to X2,Y1 (lower-right) boundary by one pixel, due to some sort of rounding errors. The Viewport settings don't affect the size or position of the 3D Rear-Plane. Viewport should not be issued within Begin/End.
4000610h - DISP_1DOT_DEPTH - 1-Dot Polygon Display Boundary Depth (W)
1-Dot Polygons are very small, or very distant polygons, which would be rendered as a single pixel on screen. Polygons with a depth value greater (more distant) than DISP_1DOT_DEPTH can be automatically hidden; in order to reduce memory consumption, or to reduce dirt on the screen.

      0-14  W-Coordinate (Unsigned, 12bit integer, 3bit fractional part)
      15-31 Not used                 (0000h=Closest, 7FFFh=Most Distant)

The DISP_1DOT_DEPTH comparision can be enabled/disabled per polygon (via POLYGON_ATTR.Bit13), so "important" polygons can be displayed regardless of their size and distance.
Note: The comparision is always using the W-coordinate of the vertex (not the Z-coordinate) (ie. no matter if using Z-buffering, or W-buffering). The polygon is rendered if at least one of its vertices is having a w-coordinate less or equal than DISP_1DOT_DEPTH. NB. despite of checking the w-coords of ALL vertices, the polygon is rendered using the color/depth/texture of its FIRST vertex.
Note: The hardware does round-up the width and height of all polygons to at least 1, so polygons of 0x0, 1x0, 0x1, and 1x1 dots will be all rounded-up to a size of 1x1. Of which, the so-called "1dot" depth check is applied only to the 0x0 dot variant (so "0dot" depth check would be a better name for it).
Caution: Although DISP_1DOT_DEPTH is a Geometry Engine parameter, it is NOT routed through GXFIFO, ie. changes will take place immediately, and will affect all following polygons, including such that are still in GXFIFO. Workaround: ensure that GXFIFO is empty before changing this parameter.
4000340h - ALPHA_TEST_REF - Alpha-Test Comparision Value (W)
Alpha Test can be enabled in DISP3DCNT.Bit2. When enabled, pixels are rendered only if their Alpha value is GREATER than ALPHA_TEST_REF. Otherwise, when disabled, pixels are rendered only if their Alpha value is GREATER than zero. Alpha Test is performed on the final polygon pixels (ie. after texture blending).

      0-4   Alpha-Test Comparision Value (0..31) (Draw pixels if Alpha>AlphaRef)
      5-31  Not used

Value 00h is effectively the same as when Alpha Test is disabled. Value 1Fh hides all polygons, including opaque ones.

DS 3D Geometry Commands

4000400h - GXFIFO - Geometry Command FIFO (W) (mirrored up to 400043Fh?)
Used to send packed commands, unpacked commands,

      0-7   First  Packed Command (or Unpacked Command)
      8-15  Second Packed Command (or 00h=None)
      16-23 Third  Packed Command (or 00h=None)
      24-31 Fourth Packed Command (or 00h=None)

and parameters,

      0-31  Parameter data for the previously sent (packed) command(s)

to the Geometry engine.
FIFO / PIPE Number of Entries
The FIFO has 256 entries, additionally, there is a PIPE with four entries (giving a total of 260 entries). If the FIFO is empty, and if the PIPE isn't full, then data is moved directly into the PIPE, otherwise it is moved into the FIFO. If the PIPE runs half empty (less than 3 entries) then 2 entries are moved from the FIFO to the PIPE. The state of the FIFO can be obtained in GXSTAT.Bit16-26, observe that there may be still data in the PIPE, even if the FIFO is empty. Check the busy flag in GXSTAT.Bit27 to see if the PIPE or FIFO contains data (or if a command is still executing).
Each PIPE/FIFO entry consists of 40bits of data (8bit command code, plus 32bit parameter value). Commands without parameters occupy 1 entry, and Commands with N parameters occupy N entries.
Sending Commands by Ports 4000440h..40005FFh
Geometry commands can be indirectly sent to the FIFO via ports 4000440h and up.
For a command with N paramters: issue N writes to the port.
For a command without parameters: issue one dummy-write to the port.
That mechanism puts the 8bit command + 32bit parameter into the FIFO/PIPE.
If the FIFO is full, then a wait is generated until data is removed from the FIFO, ie. the STR opcode gets freezed, during the wait, the bus cannot be used even by DMA, interrupts, or by the NDS7 CPU.
GXFIFO Access via DMA
Larger pre-calculated data blocks can be sent directly to the FIFO. This is usually done via DMA (use DMA in Geometry Command Mode, 32bit units, Dest=4000400h/fixed, Length=NumWords, Repeat=0). The timings are handled automatically, ie. the system (should) doesn't freeze when the FIFO is full (see below Overkill note though). DMA starts when the FIFO becomes less than half full, the DMA does then write 112 words to the GXFIFO register (or less, if the remaining DMA transfer length gets zero).
GXFIFO Access via STR,STRD,STM
If desired, STR,STRD,STM opcodes can be used to write to the FIFO.
Opcodes that write more than one 32bit value (ie. STRD and STM) can be used to send ONE UNPACKED command, plus any parameters which belong to that command. After that, there must be a 1 cycle delay before sending the next command (ie. one cannot sent more than one command at once with a single opcode, each command must be invoked by a new opcode). STRD and STM can be used because the GXFIFO register is mirrored to 4000400h..43Fh (16 words).
As with Ports 4000440h and up, the CPU gets stopped if (and as long as) the FIFO is full.
GXFIFO / Unpacked Commands

      - command1 (upper 24bit zero)
      - parameter(s) for command1 (if any)
      - command2 (upper 24bit zero)
      - parameter(s) for command2 (if any)
      - command3 (upper 24bit zero)
      - parameter(s) for command3 (if any)

GXFIFO / Packed Commands

      - command1,2,3,4 packed into one 32bit value (all bits used)
      - parameter(s) for command1 (if any)
      - parameter(s) for command2 (if any)
      - parameter(s) for command3 (if any)
      - parameter(s) for command4 (top-most packed command MUST have parameters)
      - command5,6 packed into one 32bit value (upper 16bit zero)
      - parameter(s) for command5 (if any)
      - parameter(s) for command6 (top-most packed command MUST have parameters)
      - command7,8,9 packed into one 32bit value (upper 8bit zero)
      - parameter(s) for command7 (if any)
      - parameter(s) for command8 (if any)
      - parameter(s) for command9 (top-most packed command MUST have parameters)

Packed commands are first decompressed and then stored in command the FIFO.
GXFIFO DMA Overkill on Packed Commands Without Parameters
Normally, the 112 word limit ensures that the FIFO (256 entries) doesn't get full, however, this limit is much too high for sending a lot of "Packed Commands Without Parameters" (ie. PUSH, IDENTITY, or END) - eg. sending 112 x Packed(00151515h) to GXFIFO would write 336 x Cmd(15h) to the FIFO, which is causing the FIFO to get full, and which is causing the DMA (and CPU) to be paused (for several seconds, in WORST case) until enough FIFO commands have been processed to allow the DMA to finish the 112 word transfer.
Not sure if there's much chance to get Overkills in practice. Normally most commands DO have parameters, and so, usually even LESS than 112 FIFO entries are occupied (since 8bit commands with 32bit parameters are merged into single 40bit FIFO entries).
Invalid GX commands
Invalid commands (anything else than 10h..1Ch, 20h..2Bh, 30h..33h, 40h..41h, 50h, 60h, or 70h..72h) seem to be simply ignored by the hardware (at least, testing has confirmed that they do not fetch any parameters from the gxfifo).

DS 3D Matrix Load/Multiply

4000440h - Cmd 10h - MTX_MODE - Set Matrix Mode (W)

      0-1   Matrix Mode (0..3)
             0  Projection Matrix
             1  Position Matrix (aka Modelview Matrix)
             2  Position & Vector Simultaneous Set mode (used for Light+VEC_TEST)
             3  Texture Matrix (see DS 3D Texture Coordinates chapter)
      2-31  Not used

Selects the current Matrix, all following MTX commands (load, multiply, push, pop, etc.) are applied to that matrix. In Mode 2, all MTX commands are applied to both the Position and Vector matrices. There are two special cases:

      MTX_SCALE in Mode 2:                  uses ONLY Position Matrix
      MTX_PUSH/POP/STORE/RESTORE in Mode 1: uses BOTH Position AND Vector Matrices

Ie. the four stack commands act like mode 2 (even when in mode 1; keeping the two stacks somewhat in sync), and scale acts like mode 1 (even when in mode 2; keeping the light vector length's intact).

     vice-versa for the scale command.

For the above cases, the commands do always act like mode 1, even when they are i
4000454h - Cmd 15h - MTX_IDENTITY - Load Unit Matrix to Current Matrix (W)
Sets C=I. Parameters: None
The Identity Matrix (I), aka Unit Matrix, consists of all zeroes, with a diagonal row of ones. A matrix multiplied by the Unit Matrix is left unchanged.
4000458h - Cmd 16h - MTX_LOAD_4x4 - Load 4x4 Matrix to Current Matrix (W)
Sets C=M. Parameters: 16, m[0..15]
400045Ch - Cmd 17h - MTX_LOAD_4x3 - Load 4x3 Matrix to Current Matrix (W)
Sets C=M. Parameters: 12, m[0..11]
4000460h - Cmd 18h - MTX_MULT_4x4 - Multiply Current Matrix by 4x4 Matrix (W)
Sets C=M*C. Parameters: 16, m[0..15]
4000464h - Cmd 19h - MTX_MULT_4x3 - Multiply Current Matrix by 4x3 Matrix (W)
Sets C=M*C. Parameters: 12, m[0..11]
4000468h - Cmd 1Ah - MTX_MULT_3x3 - Multiply Current Matrix by 3x3 Matrix (W)
Sets C=M*C. Parameters: 9, m[0..8]
400046Ch - Cmd 1Bh - MTX_SCALE - Multiply Current Matrix by Scale Matrix (W)
Sets C=M*C. Parameters: 3, m[0..2]
Note: MTX_SCALE doesn't change Vector Matrix (even when in MTX_MODE=2) (that's done so for keeping the length of the light vector's intact).
4000470h - Cmd 1Ch - MTX_TRANS - Mult. Curr. Matrix by Translation Matrix (W)
Sets C=M*C. Parameters: 3, m[0..2] (x,y,z position)
4000640h..67Fh - CLIPMTX_RESULT - Read Current Clip Coordinates Matrix (R)
This 64-byte region (16 words) contains the m[0..15] values of the Current Clip Coordinates Matrix, arranged in 4x4 Matrix format. Make sure that the Geometry Engine is stopped (GXSTAT.27) before reading from these registers.
The Clip Matrix is internally used to convert vertices to screen coordinates, and is internally re-calculated anytime when changing the Position or Projection matrices:

      ClipMatrix = PositionMatrix * ProjectionMatrix

To read only the Position Matrix, or only the Projection Matrix: Use Load Identity on the OTHER matrix, so the ClipMatrix becomes equal to the DESIRED matrix (multiplied by the Identity Matrix, which has no effect on the result).
4000680h..6A3h - VECMTX_RESULT - Read Current Directional Vector Matrix (R)
This 36-byte region (9 words) contains the m[0..8] values of the Current Directional Vector Matrix, arranged in 3x3 Matrix format (the fourth row/column may contain any values).
Make sure that the Geometry Engine is stopped (GXSTAT.27) before reading from these registers.

DS 3D Matrix Types

Essentially, all matrices in the NDS are 4x4 Matrices, consisting of 16 values, m[0..15]. Each element is a signed fixed-point 32bit number, with a fractional part in the lower 12bits.
The other Matrix Types are used to reduce the number of parameters being transferred, for example, 3x3 Matrix requires only nine parameters, the other seven elements are automatically set to 0 or 1.0 (whereas "1.0" means "1 SHL 12" in 12bit fixed-point notation).

       _      4x4 Matrix       _        _    Identity Matrix    _
      | m[0]  m[1]  m[2]  m[3]  |      |  1.0   0     0     0    |
      | m[4]  m[5]  m[6]  m[7]  |      |  0     1.0   0     0    |
      | m[8]  m[9]  m[10] m[11] |      |  0     0     1.0   0    |
      |_m[12] m[13] m[14] m[15]_|      |_ 0     0     0     1.0 _|

       _      4x3 Matrix       _        _  Translation Matrix   _
      | m[0]  m[1]  m[2]   0    |      |  1.0   0     0     0    |
      | m[3]  m[4]  m[5]   0    |      |  0     1.0   0     0    |
      | m[6]  m[7]  m[8]   0    |      |  0     0     1.0   0    |
      |_m[9]  m[10] m[11]  1.0 _|      |_m[0]  m[1]  m[2]   1.0 _|

       _      3x3 Matrix       _        _     Scale Matrix      _
      | m[0]  m[1]  m[2]   0    |      | m[0]   0     0     0    |
      | m[3]  m[4]  m[5]   0    |      |  0    m[1]   0     0    |
      | m[6]  m[7]  m[8]   0    |      |  0     0    m[2]   0    |
      |_ 0     0     0     1.0 _|      |_ 0     0     0     1.0 _|

DS 3D Matrix Stack

Matrix Stack
The NDS has three Matrix Stacks, and two Matrix Stack Pointers (the Coordinate Matrix stack pointer is also shared for Directional Matrix Stack).

      Matrix Stack________Valid Stack Area____Stack Pointer___________________
      Projection Stack    0..0  (1 entry)     0..1  (1bit) (GXSTAT: 1bit)
      Coordinate Stack    0..30 (31 entries)  0..63 (6bit) (GXSTAT: 5bit only)
      Directional Stack   0..30 (31 entries)  (uses Coordinate Stack Pointer)
      Texture Stack       One..None?          0..1  (1bit) (GXSTAT: N/A)

Which of the stacks/matrices depends on the current Matrix Mode (as usually,
but with one exception; stack operations MTX_PUSH/POP/STORE/RESTORE in Mode 1 are acting same as in Mode 2):

      MTX_MODE = 0      --> Projection Stack
      MTX_MODE = 1 or 2 --> BOTH Coordinate AND Directional Stack
      MTX_MODE = 3      --> Texture Stack

The initial value of the Stack Pointers is zero, the current value of the pointers can be read from GXSTAT (read-only), that register does also indicate stack overflows (errors flag gets set on read/write to invalid entries, ie. entries 1 or 1Fh..3Fh). For all stacks, the upper half (ie. 1 or 20h..3Fh) are mirrors of the lower half (ie. 0 or 0..1Fh).
4000444h - Cmd 11h - MTX_PUSH - Push Current Matrix on Stack (W)
Parameters: None. Sets [S]=C, and then S=S+1.
4000448h - Cmd 12h - MTX_POP - Pop Current Matrix from Stack (W)
Sets S=S-N, and then C=[S].

      Parameter Bit0-5:  Stack Offset (signed value, -30..+31) (usually +1)
      Parameter Bit6-31: Not used

Offset N=(+1) pops the most recently pushed value, larger offsets of N>1 will "deallocate" N values (and load the Nth value into C). Zero or negative values can be used to pop previously "deallocated" values.
The stack has only one level (at address 0) in projection mode, in that mode, the parameter value is ignored, the offset is always +1 in that mode.
400044Ch - Cmd 13h - MTX_STORE - Store Current Matrix on Stack (W)
Sets [N]=C. The stack pointer S is not used, and is left unchanged.

      Parameter Bit0-4:  Stack Address (0..30) (31 causes overflow in GXSTAT.15)
      Parameter Bit5-31: Not used

The stack has only one level (at address 0) in projection mode, in that mode, the parameter value is ignored.
4000450h - Cmd 14h - MTX_RESTORE - Restore Current Matrix from Stack (W)
Sets C=[N]. The stack pointer S is not used, and is left unchanged.

      Parameter Bit0-4:  Stack Address (0..30) (31 causes overflow in GXSTAT.15)
      Parameter Bit5-31: Not used

The stack has only one level (at address 0) in projection mode, in that mode, the parameter value is ignored.
In Projection mode, the parameter for POP, STORE, and RESTORE is unused - not sure if the parameter (ie. a dummy value) is - or is not - to be written to the command FIFO?
There appear to be actually 32 entries in Coordinate & Directional Stacks, entry 31 appears to exist, and appears to be read/write-able (although the stack overflow flag gets set when accessing it).

DS 3D Matrix Examples (Projection)

The most important matrix is the Projection Matrix (to be initialized with MTX_MODE=0 via MTX_LOAD_4x4 command). It does specify the dimensions of the view volume.
With Perspective Projections more distant objects will appear smaller, with Orthogonal Projects the size of the objects is always same regardless of their distance.

      Perspective Projection     Orthogonal Projection
                       __                  __________
           top __..--''  |            top |          |
              |   view   |                |   view   |
      Eye ----|--------->|        Eye ----|--------->|
              |__volume  |                |  volume  |
         bottom  ''--..__|          bottom|__________|
            near        far             near        far

Correctly initializing the projection matrix (as shown in the examples below) can be quite difficult (mind that fixed point multiply/divide requires to adjust the fixed-point width before/after calculation). For beginners, it may be recommended to start with a simple Identity Matrix (MTX_IDENTITY command) used as Projection Matrix (ie. Ortho with t,b,l,r set to +/-1).
Orthogonal Projections (Ortho)

      | (2.0)/(r-l)       0             0            0     |
      |      0       (2.0)/(t-b)        0            0     |
      |      0            0        (2.0)/(n-f)       0     |
      | (l+r)/(l-r)  (b+t)/(b-t)   (n+f)/(n-f)      1.0    |

n,f specify the distance from eye to near and far clip planes. t,b,l,r are the coordinates of near clip plane (top,bottom,left,right). For a symmetrical view (ie. the straight-ahead view line centered in the middle of viewport) t,b,l,r should be usually t=+ysiz/2, b=-ysiz/2, r=+xsiz/2, l=-xsiz/2; the (xsiz/ysiz) ratio should be usually equal to the viewport's (width/heigh) ratio. Examples for a asymmetrical view would be b=0 (frog's view), or t=0 (bird's view).
Left-Right Asymmetrical Perspective Projections (Frustum)

      | (2*n)/(r-l)       0             0            0     |
      |      0       (2*n)/(t-b)        0            0     |
      | (r+l)/(r-l)  (t+b)/(t-b)   (n+f)/(n-f)     -1.0    |
      |      0            0       (2*n*f)/(n-f)      0     |

n,f,t,b,l,r have same meanings as above (Ortho), the difference is that more distant objects will appear smaller with Perspective Projection (unlike Orthogonal Projection where the size isn't affected by the distance).
Left-Right Symmetrical Perspective Projections (Perspective)

      | cos/(asp*sin)     0             0            0     |
      |      0         cos/sin          0            0     |
      |      0            0        (n+f)/(n-f)     -1.0    |
      |      0            0       (2*n*f)/(n-f)      0     |

Quite the same as above (Frustum), but with symmetrical t,b values (which are in this case obtained from a vertical view range specified in degrees), and l,r are matched to the aspect ratio of the viewport (asp=height/width).
Moving the Camera
After initializing the Projection Matrix, you may multiply it with Rotate and/or Translation Matrices to change camera's position and view direction.

DS 3D Matrix Examples (Rotate/Scale/Translate)

Identity Matrix
The MTX_IDENTITY command can be used to initialize the Position Matrix before doing any Translation/Scaling/Rotation, for example:

      Load(Identity)                           ;no rotation/scaling used
      Load(Identity), Mul(Rotate), Mul(Scale)  ;rotation/scaling (not so efficient)
      Load(Rotate), Mul(Scale)                 ;rotation/scaling (more efficient)

Rotation Matrices
Rotation can be performed with MTX_MULT_3x3 command, simple examples are:

      Around X-Axis          Around Y-Axis          Around Z-Axis
      | 1.0  0     0   |     | cos   0    sin |     | cos   sin   0   |
      | 0    cos   sin |     | 0     1.0  0   |     | -sin  cos   0   |
      | 0    -sin  cos |     | -sin  0    cos |     | 0     0     1.0 |

Scale Matrix
The MTX_SCALE command allows to adjust the size of the polygon. The x,y,z parameters should be normally all having the same value, x=y=z (unless if you want to change only the height of the object, for example). Identical results can be obtained with MTX_MULT commands, however, when using lighting (MTX_MODE=2), then scaling should be done ONLY with MTX_SCALE (which keeps the length of the light's directional vector intact).
Translation Matrix
The MTX_TRANS command allows to move polygons to the desired position. The polygon VTX commands are spanning only a small range of coordinates (near zero-coordinate), so translation is required to move the polygons to other locations in the world coordinates. Aside from that, translation is useful for moved objects (at variable coordinates), and for re-using an object at various locations (eg. you can create a forest by translating a tree to different coordinates).
Matrix Multiply Order
The Matrix must be set up BEFORE sending the Vertices (which are then automatically multiplied by the matrix). When using multiple matrices multiplied with each other: Mind that, for matrix maths A*B is NOT the same as B*A. For example, if you combine Rotate and Translate Matrices, the object will be either rotated around it's own zero-coordinate, or around world-space zero-coordinate, depending on the multiply order.

DS 3D Matrix Examples (Maths Basics)

Below is a crash-course on matrix maths. Most of it is carried out automatically by the hardware. So this chapter is relevant only if you are interested in details about what happens inside of the 3D engine.
Matrix-by-Matrix Multiplication
Matrix multiplication, C = A * B, is possible only if the number of columns in A is equal to the number of rows in B, so it works fine with the 4x4 matrices which are used in the NDS. For the multiplication, assume matrix C to consist of elements cyx, and respecitively, matrix A and B to consist of elements ayx and byx. So that C = A * B looks like:

      | c11 c12 c13 c14 |     | a11 a12 a13 a14 |     | b11 b12 b13 b14 |
      | c21 c22 c23 c24 |  =  | a21 a22 a23 a24 |  *  | b21 b22 b23 b24 |
      | c31 c32 c33 c34 |     | a31 a32 a33 a34 |     | b31 b32 b33 b34 |
      | c41 c42 c43 c44 |     | a41 a42 a43 a44 |     | b41 b42 b43 b44 |

Each element in C is calculated by multiplying the elements from one row in A by the elements from the corresponding column in B, and then taking the sum of the products, ie.

      cyx = ay1*b1x + ay2*b2x + ay3*b3x + ay4*b4x

In total, that requires 64 multiplications (four multiplications for each of the 16 cyx elements), and 48 additions (three per cyx element), the hardware carries out that operation at a relative decent speed of 30..35 clock cycles, possibly by performing several multiplications simultaneously with separate multiply units.
Observe that for matrix multiplication, A*B is NOT the same as B*A.
Matrix-by-Vector & Vector-by-Matrix Multiplication
Vectors are Matrices with only one row, or only one column. Multiplication works as for normal matrices; the number of rows/columns must match up, repectively, row-vectors can be multiplied by matrices; and matrices can be multiplied by column-vectors (but not vice-versa). Eg. C = A * B:

                                                      | b11 b12 b13 b14 |
      | c11 c12 c13 c14 |  =  | a11 a12 a13 a14 |  *  | b21 b22 b23 b24 |
                                                      | b31 b32 b33 b34 |
                                                      | b41 b42 b43 b44 |

The formula for calculating the separate elements is same as above,

      cyx = ay1*b1x + ay2*b2x + ay3*b3x + ay4*b4x

Of which, C and A have only one y-index, so one may replace "cyx and ayx" by "c1x and a1x", or completely leave out the y-index, ie. "cx and ax".
Matrix-by-Number Multiplication
Simply multiply all elements of the Matrix by the number, C = A * n:

      cyx = ayx*n

Of course, works also with vectors (matrices with only one row/column).
Matrix-to-Matrix Addition/Subtraction
Both matrices must have the same number of rows & columns, add/subtract all elements with corresponding elements in other matrix, C = A +/- B:

      cyx = ayx +/- byx

Of course, works also with vectors (two matrices with only one row/column).
Vectors
A vector, for example (x,y,z), consists of offsets along x-,y-, and z-axis. The line from origin to origin-plus-offset is having two characteristics: A direction, and a length.
The length (aka magnitude) can be calculated as L=sqrt(x^2+y^2+z^2).
Vector-by-Vector Multiplication
This can be processed as LineVector*RowVector, so the result is a number (aka scalar) (aka a matrix with only 1x1 elements). Multiplying two (normalized) vectors results in: "cos(angle)=vec1*vec2", ie. the cosine of the angle between the two vectors (eg. used for light vectors). Multiplying a vector with itself, and taking the square root of the result obtains its length, ie. "length=sqrt(vec^2)".
That stuff should be done with 3-dimensional vectors (not 4-dimensionals).
Normalized Vectors
Normalized Vectors (aka Unit Vectors) are vectors with length=1.0. To normalize a vector, divide its coordinates by its length, ie. x=x/L, y=y/L, z=z/L, the direction remains the same, but the length is now 1.0.
On the NDS, normalized vectors should have a length of something less than 1.0 (eg. something like 0.99) because several NDS registers are limited to 1bit sign, 0bit integer, Nbit fractional part (so vectors that are parallel to the x,y,z axes, or that become parallel to them after rotation, cannot have a length of 1.0).
Fixed-Point Numbers
The NDS uses fixed-point numbers (rather than floating point numbers). Addition and Subtraction works as with normal integers, provided that the fractional part is the same for both numbers. If it is not the same: Shift-left the value with the smaller fractional part.
For multiplication, the fractional part of result is the sum of the fractional parts (eg. 12bit fraction * 12bit fraction = 24bit fraction; shift-right the result by 12 to convert it 12bit fraction). The NDS matrix multiply unit is maintaining the full 24bit fraction when processing the

      cyx = ay1*b1x + ay2*b2x + ay3*b3x + ay4*b4x

formula, ie. the three additions are using full 24bit fractions (with carry-outs to upper bits), the final result of the additions is then shifted-right by 12.
For division, it's vice versa, the fractions of the operands are substracted, 24bit fraction / 12bit fraction = 12bit fraction. When dividing two 12bit numbers, shift-left the first number by 12 before division to get a result with 12bit fractional part.
Four-Dimensional Matrices
The NDS uses four-dimensional matrices and vectors, ie. matrices with 4x4 elements, and vectors with 4 elements. The first three elements are associated with the X,Y,Z-axes of the three-dimensional space. The fourth element is somewhat a "W-axis".
With 4-dimensional matrices, the Translate matrix can be used to move an object to another position. Ie. once when you've setup a matrix (which may consists of pre-multiplied scaling, rotation, translation matrices), then that matrix can be used on vertices to perform the rotation, scaling, translation all-at-once; by a single Vector*Matrix operation.
With 3-dimensional matrices, translation would require a separate addition, additionally to the multiply operation.

DS 3D Polygon Attributes

40004A4h - Cmd 29h - POLYGON_ATTR - Set Polygon Attributes (W)

      0-3   Light 0..3 Enable Flags (each bit: 0=Disable, 1=Enable)
      4-5   Polygon Mode  (0=Modulation,1=Decal,2=Toon/Highlight Shading,3=Shadow)
      6     Polygon Back Surface   (0=Hide, 1=Render)  ;Line-segments are always
      7     Polygon Front Surface  (0=Hide, 1=Render)  ;rendered (no front/back)
      8-10  Not used
      11    Depth-value for Translucent Pixels    (0=Keep Old, 1=Set New Depth)
      12    Far-plane intersecting polygons       (0=Hide, 1=Render/clipped)
      13    1-Dot polygons behind DISP_1DOT_DEPTH (0=Hide, 1=Render)
      14    Depth Test, Draw Pixels with Depth    (0=Less, 1=Equal) (usually 0)
      15    Fog Enable                            (0=Disable, 1=Enable)
      16-20 Alpha      (0=Wire-Frame, 1..30=Translucent, 31=Solid)
      21-23 Not used
      24-29 Polygon ID (00h..3Fh, used for translucent, shadow, and edge-marking)
      30-31 Not used

Writes to POLYGON_ATTR have no effect until next BEGIN_VTXS command.
Changes to the Light bits have no effect until lighting is re-calculated by Normal command. The interior of Wire-frame polygons is transparent (Alpha=0), and only the lines at the polygon edges are rendered, using a fixed Alpha value of 31.
4000480h - Cmd 20h - COLOR - Directly Set Vertex Color (W)

      Parameter 1, Bit 0-4    Red
      Parameter 1, Bit 5-9    Green
      Parameter 1, Bit 10-14  Blue
      Parameter 1, Bit 15-31  Not used

The 5bit RGB values are internally expanded to 6bit RGB as follows: X=X*2+(X+31)/32, ie. zero remains zero, all other values are X=X*2+1.
Aside from by using the Color command, the color can be also changed by MaterialColor0 command (if MaterialColor0.Bit15 is set, it acts identical as the Color Command), and by the Normal command (which calculates the color based on light/material parameters).
Depth Test
The Depth Test compares the depth of the pixels of the polygon with the depth of previously rendered polygons (or of the rear plane if there have been none rendered yet). The new pixels are drawn if the new depth is Less (closer to the camera), or if it is Equal, as selected by POLYGON_ATTR.Bit14.
Normally, Depth Equal would work only exact matches (ie. if the overlapping polygons have exactly the same coordinates; and thus have the same rounding errors), however, the NDS hardware is allowing "Equal" to have a tolerance of +/-200h (within the 24bit depth range of 0..FFFFFFh), that may bypass rounding errors, but it may also cause nearby polygons to be accidently treated to have equal depth.

DS 3D Polygon Definitions by Vertices

The DS supports polygons with 3 or 4 edges, triangles and quadliterals.
The position of the edges is defined by vertices, each consisting of (x,y,z) values.
For Line Segments, use Triangles with twice the same vertex, Line Segments are rendered always because they do not have any front and back sides.
The Prohibited Quad shapes may produce unintended results, namely, that are Quads with crossed sides, and quads with angles greater than 180 degrees.

      Separate Tri.     Triangle Strips   Line Segment
      v0                 v2___v4____v6
      |\      v3         /|\  |\    /\     v0    v1
      | \     /\      v0( | \ | \  /  \     ------
      |__\   /__\        \|__\|__\/____\         v2
      v1 v2 v4  v5       v1   v3  v5   v7

      Separate Quads          Quadliteral Strips         Prohibited Quads
        v0__v3                 v0__v2____v4     v10__    v0__v3     v4
         /  \   v4____v7        /  \     |\ _____ / /v11   \/       |\
        /    \   |    \        /    \    | |v6 v8| /       /\     v5| \
       /______\  |_____\      /______\___|_|_____|/       /__\     /___\
       v1    v2  v5    v6     v1    v3  v5 v7   v9       v2   v1   v6   v7

The vertices are normally arranged anti-clockwise, except that: in triangle-strips each second polygon uses clockwise arranged vertices, and quad-strips are sorts of "up-down" arranged (whereas "up" and "down" may be anywhere due to rotation). Other arrangements may result in quads with crossed lines, or may swap the front and back sides of the polygon (above examples are showing the front sides).
4000500h - Cmd 40h - BEGIN_VTXS - Start of Vertex List (W)

      Parameter 1, Bit 0-1    Primitive Type (0..3, see below)
      Parameter 1, Bit 2-31   Not used

Indicates the Start of a Vertex List, and its Primitive Type:

      0  Separate Triangle(s)    ;3*N vertices per N triangles
      1  Separate Quadliteral(s) ;4*N vertices per N quads
      2  Triangle Strips         ;3+(N-1) vertices per N triangles
      3  Quadliteral Strips      ;4+(N-1)*2 vertices per N quads

The BEGIN_VTX command should be followed by VTX_-commands to define the Vertices of the list, and should be then terminated by END_VTX command.
BEGIN_VTX additionally applies changes to POLYGON_ATTR.
4000504h - Cmd 41h - END_VTXS - End of Vertex List (W)
Parameters: None. This is a Dummy command for OpenGL compatibility. It should be used to terminate a BEGIN_VTX, VTX_<values> sequence. END_VTXS is possibly required for Nintendo's software emulator? On real NDS consoles (and in no$gba) it does have no effect, it can be left out, or can be issued multiple times inside of a vertex list, without disturbing the display.
400048Ch - Cmd 23h - VTX_16 - Set Vertex XYZ Coordinates (W)

      Parameter 1, Bit 0-15   X-Coordinate (signed, with 12bit fractional part)
      Parameter 1, Bit 16-31  Y-Coordinate (signed, with 12bit fractional part)
      Parameter 2, Bit 0-15   Z-Coordinate (signed, with 12bit fractional part)
      Parameter 2, Bit 16-31  Not used

4000490h - Cmd 24h - VTX_10 - Set Vertex XYZ Coordinates (W)

      Parameter 1, Bit 0-9    X-Coordinate (signed, with 6bit fractional part)
      Parameter 1, Bit 10-19  Y-Coordinate (signed, with 6bit fractional part)
      Parameter 1, Bit 20-29  Z-Coordinate (signed, with 6bit fractional part)
      Parameter 1, Bit 30-31  Not used

Same as VTX_16, with only one parameter, with smaller fractional part.
4000494h - Cmd 25h - VTX_XY - Set Vertex XY Coordinates (W)

      Parameter 1, Bit 0-15   X-Coordinate (signed, with 12bit fractional part)
      Parameter 1, Bit 16-31  Y-Coordinate (signed, with 12bit fractional part)

The Z-Coordinate is kept unchanged, and re-uses the value from previous VTX.
4000498h - Cmd 26h - VTX_XZ - Set Vertex XZ Coordinates (W)

      Parameter 1, Bit 0-15   X-Coordinate (signed, with 12bit fractional part)
      Parameter 1, Bit 16-31  Z-Coordinate (signed, with 12bit fractional part)

The Y-Coordinate is kept unchanged, and re-uses the value from previous VTX.
400049Ch - Cmd 27h - VTX_YZ - Set Vertex YZ Coordinates (W)

      Parameter 1, Bit 0-15   Y-Coordinate (signed, with 12bit fractional part)
      Parameter 1, Bit 16-31  Z-Coordinate (signed, with 12bit fractional part)

The X-Coordinate is kept unchanged, and re-uses the value from previous VTX.
40004A0h - Cmd 28h - VTX_DIFF - Set Relative Vertex Coordinates (W)

      Parameter 1, Bit 0-9    X-Difference (signed, with 9/12bit fractional part)
      Parameter 1, Bit 10-19  Y-Difference (signed, with 9/12bit fractional part)
      Parameter 1, Bit 20-29  Z-Difference (signed, with 9/12bit fractional part)
      Parameter 1, Bit 30-31  Not used

Sets XYZ-Coordinate relative to the XYZ-Coordinates from previous VTX. In detail: The 9bit fractional values are divided by 8 (sign expanded to 12bit fractions, in range +/-0.125), and that 12bit fraction is then added to the old vtx coordinates. The result of the addition should not overflow 16bit vertex coordinate range (1bit sign, 3bit integer, 12bit fraction).
Notes on VTX commands
On each VTX command, the viewport coordinates of the vertex are calculated and stored in Vertex RAM,

      ( xx, yy, zz, ww ) = ( x, y, z, 1.0 ) * ClipMatrix

The actual screen position (in pixels) is then,

      screen_x = (xx+ww)*viewport_width / (2*ww) + viewport_x1
      screen_y = (yy+ww)*viewport_height / (2*ww) + viewport_y1

Each VTX command that completes the definition of a polygon (ie. each 3rd for Separate Trangles) does additionally store data in Polygon List RAM.
VTX commands may be issued only between Begin and End commands.
Clipping
Polygons are clipped to the 6 sides of the view volume (ie. to the left, right, top, bottom, near, and far edges). If one or more vertic(es) exceed one of these sides, then these vertic(es) are replaced by two newly created vertices (which are located on the intersections of the polygon edges and the view volume edge).
Depending on the number of clipped vertic(es), this may increase or decrease the number of entries in Vertex RAM (ie. minus N clipped vertices, plus 2 new vertices). Also, clipped polygons which are part of polygon strips are converted to separate polygons (which does increase number of entries in Vertex RAM). Polygons that are fully outside of the View Volume aren't stored in Vertex RAM, nor in Polygon RAM (the only exception are polygons that are located exactly one pixel below of, or right of lower/right edges, which appear to be accidently stored in memory).

DS 3D Polygon Light Parameters

The lighting operation is performed by executing the Normal command (which sets the VertexColor based on the Light/Material parameters) (to the rest of the hardware it doesn't matter if the VertexColor was set by Color command or by Normal command). Light is calculated only for the Front side of the polygon (assuming that the Normal is matched to that side), so the Back side will be (incorrectly) using the same color.
40004C8h - Cmd 32h - LIGHT_VECTOR - Set Light's Directional Vector (W)
Sets direction of the specified light (ie. the light selected in Bit30-31).

      0-9   Directional Vector's X component (1bit sign + 9bit fractional part)
      10-19 Directional Vector's Y component (1bit sign + 9bit fractional part)
      20-29 Directional Vector's Z component (1bit sign + 9bit fractional part)
      30-31 Light Number                     (0..3)

Upon executing this command, the incoming vector is multiplied by the current Directional Matrix, the result is then applied as LightVector. This allows to rotate the light direction. However, normally, to keep the light unrotated, be sure to use LoadIdentity (in MtxMode=2) before setting the LightVector.
40004CCh - Cmd 33h - LIGHT_COLOR - Set Light Color (W)
Sets the color of the specified light (ie. the light selected in Bit30-31).

      0-4   Red          (0..1Fh)      ;\light color this will be combined with
      5-9   Green        (0..1Fh)      ; diffuse, specular, and ambient colors
      10-14 Blue         (0..1Fh)      ;/upon execution of the normal command
      15-29 Not used
      30-31 Light Number (0..3)

40004C0h - Cmd 30h - DIF_AMB - MaterialColor0 - Diffuse/Ambient Reflect. (W)

      0-4   Diffuse Reflection Red     ;\light(s) that directly hits the polygon,
      5-9   Diffuse Reflection Green   ; ie. max when NormalVector has opposite
      10-14 Diffuse Reflection Blue    ;/direction of LightVector
      15    Set Vertex Color (0=No, 1=Set Diffuse Reflection Color as Vertex Color)
      16-20 Ambient Reflection Red     ;\light(s) that indirectly hits the polygon,
      21-25 Ambient Reflection Green   ; ie. assuming that light is reflected by
      26-30 Ambient Reflection Blue    ;/walls/floor, regardless of LightVector
      31    Not used

With Bit15 set, the lower 15bits are applied as VertexColor (exactly as when when executing the Color command), the purpose is to use it as default color (eg. when outcommenting the Normal command), normally, when using lighting, the color setting gets overwritten (as soon as executing the Normal command).
40004C4h - Cmd 31h - SPE_EMI - MaterialColor1 - Specular Ref. & Emission (W)

      0-4   Specular Reflection Red    ;\light(s) reflected towards the camera,
      5-9   Specular Reflection Green  ; ie. max when NormalVector is in middle of
      10-14 Specular Reflection Blue   ;/LightVector and ViewDirection
      15    Specular Reflection Shininess Table (0=Disable, 1=Enable)
      16-20 Emission Red               ;\light emitted by the polygon itself,
      21-25 Emission Green             ; ie. regardless of light colors/vectors,
      26-30 Emission Blue              ;/and no matter if any lights are enabled
      31    Not used

Caution: Specular Reflection WON'T WORK when the ProjectionMatrix is rotated.
40004D0h - Cmd 34h - SHININESS - Specular Reflection Shininess Table (W)
Write 32 parameter words (each 32bit word containing four 8bit entries), entries 0..3 in the first word, through entries 124..127 in the last word:

      0-7   Shininess 0 (unsigned fixed-point, 0bit integer, 8bit fractional part)
      8-15  Shininess 1 ("")
      16-23 Shininess 2 ("")
      24-31 Shininess 3 ("")

If the table is disabled (by MaterialColor1.Bit15), then reflection will act as if the table would be filled with linear increasing numbers.
4000484h - Cmd 21h - NORMAL - Set Normal Vector (W)
In short, this command does calculate the VertexColor, based on the various light-parameters.
In detail, upon executing this command, the incoming vector is multiplied by the current Directional Matrix, the result is then applied as NormalVector (giving it the same rotation as used for the following polygon vertices).

      0-9   X-Component of Normal Vector (1bit sign + 9bit fractional part)
      10-19 Y-Component of Normal Vector (1bit sign + 9bit fractional part)
      20-29 Z-Component of Normal Vector (1bit sign + 9bit fractional part)
      30-31 Not used

Defines the Polygon's Normal. And, does then update the Vertex Color; by recursing the View Direction, the NormalVector, the LightVector(s), and Light/Material Colors. The execution time of the Normal command varies depending on the number of enabled light(s).
Additional Light Registers
Additionally to above registers, light(s) must be enabled in PolygonAttr (mind that changes to PolygonAttr aren't applied until next Begin command). And, the Directional Matrix must be set up correctly (in MtxMode=2) for the LightVector and NormalVector commands.
Normal Vector
The Normal vector must point "away from the polygon surface" (eg. for the floor, the Normal should point upwards). That direction is implied by the polygon vertices, however, the hardware cannot automatically calculate it, so it must be set manually with the Normal command (prior to the VTX-commands).
When using lighting, the Normal command must be re-executed after switching Lighting on/off, or after changing light/material parameters. And, of course, also before defining polygons with different orientation. Polygons with same orientation (eg. horizontal polygon surfaces) and same material color can use the same Normal. Changing the Normal per polygon gives differently colored polygons with flat surfaces, changing the Normal per vertex gives the illusion of curved surfaces.
Light Vector
Each light consists of parallel beams; similar to sunlight, which appears to us (due to the great distance) to consist of parallel beams, all emmitted into the same direction; towards Earth.
In reality, light is emitted into ALL directions, originated from the light source (eg. a candle), the hardware doesn't support that type of non-parallel light. However, the light vectors can be changed per polygon, so a polygon that is located north of the light source may use different light direction than a polygon that is east of the light source.
And, of course, Light 0..3 may (and should) have different directions.
Normalized Vectors
The Normal Vector and the Light Vectors should be normalized (ie. their length should be 1.0) (in practice: something like 0.99, since the registers have only fractional parts) (a length of 1.0 can cause overflows).
Lighting Limitations
The functionality of the light feature is limited to reflecting light to the camera (light is not reflected to other polygons, nor does it cast shadows on other polygons). However, independently of the lighting feature, the DS hardware does allow to create shadows, see:
DS 3D Shadow Polygons
Internal Operation on Normal Command

      IF TexCoordTransformMode=2 THEN TexCoord=NormalVector*Matrix (see TexCoord)
      NormalVector=NormalVector*DirectionalMatrix
      VertexColor = EmissionColor
      FOR i=0 to 3
       IF PolygonAttrLight[i]=enabled THEN
        DiffuseLevel = max(0,-(LightVector[i]*NormalVector))
        ShininessLevel = max(0,(-HalfVector[i])*(NormalVector))^2
        IF TableEnabled THEN ShininessLevel = ShininessTable[ShininessLevel]
        ;note: below processed separately for the R,G,B color components...
        VertexColor = VertexColor + SpecularColor*LightColor[i]*ShininessLevel
        VertexColor = VertexColor + DiffuseColor*LightColor[i]*DiffuseLevel
        VertexColor = VertexColor + AmbientColor*LightColor[i]
       ENDIF
      NEXT i

Internal Operation on Light_Vector Command (for Light i)

      LightVector[i] = (LightVector*DirectionalMatrix)
      HalfVector[i] = (LightVector[i]+LineOfSightVector)/2

LineOfSightVector (how it SHOULD work)
Ideally, the LineOfSightVector should point from the camera to the vertic(es), however, the vertic(es) are still unknown at time of normal command, so it is just pointing from the camera to the screen, ie.

      LineOfSightVector = (0,0,-1.0)

Moreover, the LineOfSightVector should be multiplied by the Projection Matrix (so the vector would get rotated accordingly when the camera gets rotated), and, after multiplication by a scaled matrix, it'd be required to normalize the resulting vector.
LineOfSightVector (how it DOES actually work)
However, the NDS cannot normalize vectors by hardware, and therefore, it does completely leave out the LineOfSightVector*ProjectionMatrix multiplication. So, the LineOfSightVector is always (0,0,-1.0), no matter of any camera rotation. That means,

      Specular Reflection WON'T WORK when the ProjectionMatrix is rotated (!)

So, if you want to rotate the "camera" (in MTX_MODE=0), then you must instead rotate the "world" in the opposite direction (in MTX_MODE=2).
That problem applies only to Specular Reflection, ie. only if Lighting is used, and only if the Specular Material Color is nonzero.
Maths Notes
Note on Vector*Vector multiplication: Processed as LineVector*RowVector, so the result is a number (aka scalar) (aka a matrix with only 1x1 elements), multiplying two (normalized) vectors results in: "cos(angle)=vec1*vec2", ie. the cosine of the angle between the two vectors.
The various Normal/Light/Half/Sight vectors are only 3-dimensional (x,y,z), ie. only the upper-left 3x3 matrix elements are used on multiplications with the 4x4 DirectionalMatrix.

DS 3D Shadow Polygons

The DS hardware's Light-function allows to reflect light to the camera, it does not reflect light to other polygons, and it does not cast any shadows. For shadows at fixed locations it'd be best to pre-calculate their shape and position, and to change the vertex color of the shaded polygons.
Additionally, the Shadow Polygon feature can be used to create animated shadows, ie. moved objects and variable light sources.
Shadow Polygons and Shadow Volume
The software must define a Shadow Volume (ie. the region which doesn't contain light), the hardware does then automatically draw the shadow on all pixels whose x/y/z-coordinates are inside of that region.
The Shadow Volume must be defined by several Shadow Polygons which are enclosing the shaded region. The 'top' of the shadow volume should be usually translated to the position of the object that casts the shadow, if the light direction changes then the shadow volume should be also rotated to match the light direction. The 'length' of the shadow volume should be (at least) long enough to reach from the object to the walls/floor where the shadow is to be drawn. The shadow volume must be passed TWICE to the hardware:
Step 1 - Shadow Volume for Mask
Set Polygon_Attr Mode=Shadow, PolygonID=00h, Back=Render, Front=Hide, Alpha=01h..1Eh, and pass the shadow volume (ie. the shadow polygons) to the geometry engine.
The Back=Render / Front=Hide setting causes the 'rear-side' of the shadow volume to be rendered, of course only as far as it is in front of other polygons. The Mode=Shadow / ID=00h setting causes the polygon NOT to be drawn to the Color Buffer - instead, flags are set in the Stencil Buffer (to be used in Step 2).
Step 2 - Shadow Volume for Rendering
Simply repeat step 1, but with Polygon_Attr Mode=Shadow, PolygonID=01h..3Fh, Back=Render(what/why?), Front=Render, Alpha=01h..1Eh.
The Front=Render setting causes the 'front-side' of the shadow volume to be rendered, again, only as far as it is in front of other polygons. The Mode=Shadow / ID>00h setting causes the polygon to be drawn to the Color Buffer as usually, but only if the Stencil Buffer bits are zero (ie. the portion from Step 1 is excluded) (additionally, Step 2 resets the stencil bits after checking them). Moreover, the shadow is rendered only if its Polygon ID differs from the ID in the Attribute Buffer.
Shadow Alpha and Shadow Color
The Alpha=Translucent setting in Step 1 and 2 ensures that the Shadow is drawn AFTER the normal (opaque) polygons have been rendered. In Step 2 it does additionally specify the 'intensity' of the shadow. For normal shadows, the Vertex Color should be usually black, however, the shadow volume may be also used as 'spotlight volume' when using other colors.
Rendering Order
The Mask Volume must be rendered prior to the Rendering Volume, ie. Step 1 and 2 must be performed in that order, and, to keep that order intact, Auto-sorting must have been disabled in the previous Swap_Buffers command.
The shadow volume must be rendered after the 'target' polygons have been rendered, for opaque targets this is done automatically (due to the translucent alpha setting; translucent polygons are always rendered last, even with auto-sort disabled).
Translucent Targets
Casting shadows on Translucent Polygons. First draw the translucent target (with update depth buffer enabled, required for the shadow z-coordinates), then draw the Shadow Mask/Rendering volumes.
Due to the updated depth buffer the shadow will be cast only on the translucent target (not on any other polygons underneath of the translucent polygon). If you want the shadow to appear on both: Draw draw the Shadow Mask/Rendering volume TWICE (once before, and once after drawing the translucent target).
Polygon ID and Fog Enable
The "Render only if Polygon ID differs" feature (see Step 2) allows to prevent the shadow to be cast on the object that casts the shadow (ie. the object and shadow should have the same IDs). The feature also allows to select whether overlapping shadows (with same/different IDs) are shaded once or twice.
The old Fog Enable flag in the Attribute Buffer is ANDed with the Fog Enable flag of the Shadow Polygons, this allows to exclude Fog in shaded regions.
Shadow Volume Open/Closed Shapes
Normally, the shadow volume should have a closed shape, ie. should have rear-sides (step 1), and corresponding front-sides (step 2) for all possible viewing angles. That is required for the shadow to be drawn correctly, and also for the Stencil Buffer to be reset to zero (in step 2, so that the stencil bits won't disturb other shadow volumes).
Due to that, drawing errors may occur if the shadow volume's front or rear side gets clipped by near/far clip plane.
One exception is that the volume doesn't need a bottom-side (with a suitable volume length, the bottom may be left open, since it vanishes in the floor/walls anyways).

DS 3D Texture Attributes

4000488h - Cmd 22h - TEXCOORD - Set Texture Coordinates (W)
Specifies the texture source coordinates within the texture bitmap which are to be associated with the next vertex.

      Parameter 1, Bit 0-15   S-Coordinate (X-Coordinate in Texture Source)
      Parameter 1, Bit 16-31  T-Coordinate (Y-Coordinate in Texture Source)
      Both values are 1bit sign + 11bit integer + 4bit fractional part.
      A value of 1.0 (=1 SHL 4) equals to one Texel.

With Position 0.0 , 0.0 drawing starts from upperleft of the Texture.
With positive offsets, drawing origin starts more "within" the texture.
With negative offsets, drawing starts "before" the texture.
"When texture mapping, the Geometry Engine works faster if you issue commands in the order TexCoord -> Normal -> Vertex."
40004A8h - Cmd 2Ah - TEXIMAGE_PARAM - Set Texture Parameters (W)

      0-15  Texture VRAM Offset div 8 (0..FFFFh -> 512K RAM in Slot 0,1,2,3)
            (VRAM must be allocated as Texture data, see Memory Control chapter)
      16    Repeat in S Direction (0=Clamp Texture, 1=Repeat Texture)
      17    Repeat in T Direction (0=Clamp Texture, 1=Repeat Texture)
      18    Flip in S Direction   (0=No, 1=Flip each 2nd Texture) (requires Repeat)
      19    Flip in T Direction   (0=No, 1=Flip each 2nd Texture) (requires Repeat)
      20-22 Texture S-Size        (for N=0..7: Size=(8 SHL N); ie. 8..1024 texels)
      23-25 Texture T-Size        (for N=0..7: Size=(8 SHL N); ie. 8..1024 texels)
      26-28 Texture Format        (0..7, see below)
      29    Color 0 of 4/16/256-Color Palettes (0=Displayed, 1=Made Transparent)
      30-31 Texture Coordinates Transformation Mode (0..3, see below)

Texture Formats:

      0  No Texture
      1  A3I5 Translucent Texture
      2  4-Color Palette Texture
      3  16-Color Palette Texture
      4  256-Color Palette Texture
      5  4x4-Texel Compressed Texture
      6  A5I3 Translucent Texture
      7  Direct Texture

Texture Coordinates Transformation Modes:

      0  Do not Transform texture coordinates
      1  TexCoord source
      2  Normal source
      3  Vertex source

The S-Direction equals to the horizontal direction of the source bitmap.
The T-Direction, T-repeat, and T-flip are the same in vertical direction.
For a "/" shaped texture, the S-clamp, S-repeat, and S-flip look like so:

      Clamp _____  Repeat       Repeat+Flip
      _____/       ///////////  /\/\/\/\/\/

With "Clamp", the texture coordinates are clipped to MinMax(0,Size-1), so the texels at the edges of the texture bitmap are repeated (to avoid that effect, fill the bitmap edges by texels with alpha=0, so they become invisible).
40004ACh - Cmd 2Bh - PLTT_BASE - Set Texture Palette Base Address (W)

      0-12   Palette Base Address (div8 or div10h, see below)
             (Not used for Texture Format 7: Direct Color Texture)
             (0..FFF8h/8 for Texture Format 2: ie. 4-color-palette Texture)
             (0..17FF0h/10h for all other Texture formats)
      13-31  Not used

The palette data occupies 16bit per color, Bit0-4: Red, Bit5-9: Green, Bit10-14: Blue, Bit15: Not used.
(VRAM must be allocated as Texture Palette, there can be up to 6 Slots allocated, ie. the addressable 18000h bytes, see Memory Control chapter)
TexImageParam and TexPlttBase
Can be issued per polygon (except within polygon strips).

DS 3D Texture Formats

Format 2: 4-Color Palette Texture
Each Texel occupies 2bit, the first Texel is located in LSBs of 1st byte.
In this format, the Palette Base is specified in 8-byte steps; all other formats use 16-byte steps (see PLTT_BASE register).
Format 3: 16-Color Palette Texture
Each Texel occupies 4bit, the 1st Texel is located in LSBs of 1st byte.
Format 4: 256-Color Palette Texture
Each Texel occupies 8bit, the 1st Texel is located in 1st byte.
Format 7: Direct Color Texture
Each Texel occupies 16bit, the 1st Texel is located in 1st halfword.
Bit0-4: Red, Bit5-9: Green, Bit10-14: Blue, Bit15: Alpha
Format 1: A3I5 Translucent Texture (3bit Alpha, 5bit Color Index)
Each Texel occupies 8bit, the 1st Texel is located in 1st byte.

      Bit0-4: Color Index (0..31) of a 32-color Palette
      Bit5-7: Alpha       (0..7; 0=Transparent, 7=Solid)

The 3bit Alpha value (0..7) is internally expanded into a 5bit Alpha value (0..31) as follows: Alpha=(Alpha*4)+(Alpha/2).
Format 6: A5I3 Translucent Texture (5bit Alpha, 3bit Color Index)
Each Texel occupies 8bit, the 1st Texel is located in 1st byte.

      Bit0-2: Color Index (0..7) of a 8-color Palette
      Bit3-7: Alpha       (0..31; 0=Transparent, 31=Solid)

Format 5: 4x4-Texel Compressed Texture
Consists of 4x4 Texel blocks in Slot 0 or 2, 32bit per block, 2bit per Texel,

      Bit0-7   Upper 4-Texel row (LSB=first/left-most Texel)
      Bit8-15  Next  4-Texel row ("")
      Bit16-23 Next  4-Texel row ("")
      Bit24-31 Lower 4-Texel row ("")

Additional Palette Index Data for each 4x4 Texel Block is located in Slot 1,

      Bit0-13  Palette Offset in 4-byte steps; Addr=(PLTT_BASE*10h)+(Offset*4)
      Bit14-15 Transparent/Interpolation Mode (0..3, see below)

whereas, the Slot 1 offset is related to above Slot 0 or 2 offset,

      slot1_addr = slot0_addr / 2           ;lower 64K of Slot1 assoc to Slot0
      slot1_addr = slot2_addr / 2 + 10000h  ;upper 64K of Slot1 assoc to Slot2

The 2bit Texel values (0..3) are intepreted depending on the Mode (0..3),

      Texel  Mode 0       Mode 1             Mode 2         Mode 3
      0      Color 0      Color0             Color 0        Color 0
      1      Color 1      Color1             Color 1        Color 1
      2      Color 2      (Color0+Color1)/2  Color 2        (Color0*5+Color1*3)/8
      3      Transparent  Transparent        Color 3        (Color0*3+Color1*5)/8

Mode 1 and 3 are using only 2 Palette Colors (which requires only half as much Palette memory), the 3rd (and 4th) Texel Colors are automatically set to above values (eg. to gray-shades if color 0 and 1 are black and white).
Note: The maximum size for 4x4-Texel Compressed Textures is 1024x512 or 512x1024 (which are both occupying the whole 128K in slot 0 or 2, plus 64K in slot1), a larger size of 1024x1024 cannot be used because of the gap between slot 0 and 2.

DS 3D Texture Coordinates

For textured polygons, a texture coordinate must be associated with each vertex of the polygon. The coordinates (S,T) are defined by TEXCOORD command (typically issued prior to each VTX command), and can be optionally automatically transformed, by the Transformation Mode selected in TEXIMAGE_PARAM register.
Texture Matrix
Although the texture matrix is 4x4, with values m[0..15], only the left two columns of this matrix are actually used. In Mode 2 and 3, the bottom row of the matrix is replaced by S and T values from most recent TEXCOORD command.
Texture Coordinates Transformation Mode 0 - No Transform
The values are set upon executing the TEXCOORD command,

      ( S' T' )  =  ( S  T )

Simple coordinate association, without using the Texture Matrix at all.
Texture Coordinates Transformation Mode 1 - TexCoord source
The values are calculated upon executing the TEXCOORD command,

                                         | m[0]  m[1]  |
      ( S' T' )  =  ( S  T 1/16 1/16 ) * | m[4]  m[5]  |
                                         | m[8]  m[9]  |
                                         | m[12] m[13] |

Can be used to produce a simple texture scrolling, rotation, or scaling, by setting a translate, rotate, or scale matrix for the texture matrix.
Texture Coordinates Transformation Mode 2 - Normal source
The values are calculated upon executing the NORMAL command,

                                         | m[0]  m[1]  |
      ( S' T' )  =  ( Nx  Ny  Nz 1.0 ) * | m[4]  m[5]  |
                                         | m[8]  m[9]  |
                                         | S     T     |

Can be used to produce spherical reflection mapping by setting the texture matrix to the current directional vector matrix, multiplied by a scaling matrix that expands the directional vector space from -1.0..+1.0 to one half of the texture size. For that purpose, translate the origin of the texture coordinate to the center of the spherical texture by using TexCoord command (spherical texture means a bitmap that contains some circle-shaped image).
Texture Coordinates Transformation Mode 3 - Vertex source
The values are calculated upon executing any VTX commands,

                                         | m[0]  m[1]  |
      ( S' T' )  =  ( Vx  Vy  Vz 1.0 ) * | m[4]  m[5]  |
                                         | m[8]  m[9]  |
                                         | S     T     |

Can be used to produce texture scrolls dependent on the View coordinates by copying the current position coordinate matrix into the texture matrix. For example, the PositionMatrix can be obtained via CLIPMTX_RESULT (see there for details), and that values can be then manually copied to the TextureMatrix.
Sign+Integer+Fractional Parts used in above Formulas

      Matrix    m[..]     1+19+12 (32bit)
      Vertex    Vx,Vy,Vz  1+3+12  (16bit)
      Normal    Nx,Ny,Nz  1+0+9   (10bit)
      Constant  1.0       0+1+0   (1bit)
      Constant  1/16      0+0+4   (4bit)
      TexCoord  S,T       1+11+4  (16bit)
      Result    S',T'     1+11+4  (16bit) <-------- clipped to that size !

Observe that the S',T' values are clipped to 16bit size. Ie. after the Vector*Matrix calaction, the result is shifted right (to make it having a 4bit fraction), and the value is then masked to 16bit size.

DS 3D Texture Blending

Polygon pixels consist of a Vertex Color, and of Texture Colors.
These colors can be blended as described below. Or, to use only either one:
To use only the Vertex Color: Select No Texture in TEXIMAGE_PARAM.
To use only the Texture Color: Select Modulation Mode and Alpha=31 in POLYGON_ATTR, and set COLOR to 7FFFh (white), or to gray values (to decrease brightness of the texture color).
Vertex Color (Rv,Gv,Bv,Av)
The Vertex Color (Rv,Gv,Bv) can be changed per Vertex (either by Color, Normal, or Material0 command), pixels between vertices are shaded to medium values of the surrounding vertices. The Vertex Alpha (Av), can be changed only per polygon (by PolygonAttr command).
Texture Colors (Rt,Gt,Bt,At)
The Texture Colors (Rt,Gt,Bt), and Alpha value (At), are defined by the Texture Bitmap. For formats without Alpha value, assume At=31 (solid), and for formats with 1bit Alpha assume At=A*31.
Shading Table Colors (Rs,Gs,Bs)
In Toon/Highlight Shading Mode, the red component of the Vertex Color (Rv) is mis-used as an index in the Shading Table, ie. Rv is used to read Shading Colors (Rs,Gs,Bs) from the table; the green and blue components of the Vertex Color (Gv,Bv) are unused in this mode. The Vertex Alpha (Av) is kept used.
Shading is used in Polygon Mode 2, whether it is Toon or Highlight Shading is selected in DISP3DCNT; this is a per-frame selection, so only either one can be used.
Texture Blending - Modulation Mode (Polygon Attr Mode 0)

      R = ((Rt+1)*(Rv+1)-1)/64
      G = ((Gt+1)*(Gv+1)-1)/64
      B = ((Bt+1)*(Bv+1)-1)/64
      A = ((At+1)*(Av+1)-1)/64

The multiplication result is decreased intensity (unless both factors are 63).
Texture Blending - Decal Mode (Polygon Attr Mode 1)

      R = (Rt*At + Rv*(63-At))/64  ;except, when At=0: R=Rv, when At=31: R=Rt
      G = (Gt*At + Gv*(63-At))/64  ;except, when At=0: G=Gv, when At=31: G=Gt
      B = (Bt*At + Bv*(63-At))/64  ;except, when At=0: B=Bv, when At=31: B=Bt
      A = Av

The At value is used (only) as ratio for Texture color vs Vertex Color.
Texture Blending - Toon Shading (Polygon Mode 2, DISP3DCNT=Toon)
The vertex color Red component (Rv) is used as an index in the toon table.

      R = ((Rt+1)*(Rs+1)-1)/64   ;Rs=ToonTableRed[Rv]
      G = ((Gt+1)*(Gs+1)-1)/64   ;Gs=ToonTableGreen[Rv]
      B = ((Bt+1)*(Bs+1)-1)/64   ;Bs=ToonTableBlue[Rv]
      A = ((At+1)*(Av+1)-1)/64

This is same as Modulation Mode, but using Rs,Gs,Bs instead Rv,Gv,Bv.
Texture Blending - Highlight Shading (Polygon Mode 2, DISP3DCNT=Highlight)

      R = ((Rt+1)*(Rs+1)-1)/64+Rs ;truncated to MAX=63
      G = ((Gt+1)*(Gs+1)-1)/64+Gs ;truncated to MAX=63
      B = ((Bt+1)*(Bs+1)-1)/64+Bs ;truncated to MAX=63
      A = ((At+1)*(Av+1)-1)/64

Same as Toon Shading, with additional addition offset, the addition may increase the intensity, however, it may also change the hue of the color.
Above formulas are for 6bit RGBA values, ie. 5bit values internally expanded to 6bit as such: IF X>0 THEN X=X*2+1.
Uni-Colored Textures
Although textures are normally containing "pictures", in some cases it makes sense to use "blank" textures that are filled with a single color:
Wire-frame polygons are always having Av=31, however, they can be made transparent by using Translucent Textures (ie. A5I3 or A3I5 formats) with At<31.
In Toon/Highlight shading modes, the Vertex Color is mis-used as table index, however, Toon/Highlight shading can be used on uni-colored textures, which is more or less the same as using Toon/Highlight shading on uni-colored Vertex-colors.

DS 3D Toon, Edge, Fog, Alpha-Blending, Anti-Aliasing

4000380h..3BFh - TOON_TABLE - Toon Table (W)
This 64-byte region contains the 32 toon colors (16bit per color), used for both Toon and Highlight Shading. In both modes, the Red (R) component of the RGBA vertex color is mis-used as index to obtain the new RGB value from the toon table, vertex Alpha (A) is kept used as is.

      Bit0-4: Red, Bit5-9: Green, Bit10-14: Blue, Bit15: Not Used

Shading can be enabled (per polygon) in Polygon_Attr, whether it is Toon or Highlight Shading is set (per frame) in DISP3DCNT. For more info on shading, see:
DS 3D Texture Blending
4000330h..33Fh - EDGE_COLOR - Edge Colors 0..7 (W)
This 16-byte region contains the 8 edge colors (16bit per color), Edge Color 0 is used for Polygon ID 00h..07h, Color 1 for ID 08h..0Fh, and so on.

      Bit0-4: Red, Bit5-9: Green, Bit10-14: Blue, Bit15: Not Used

Edge Marking allows to mark the edges of an object (whose polygons all have the same ID) in a wire-frame style. Edge Marking can be enabled (per frame) in DISP3DCNT. When enabled, the polygon edges are drawn at the edge color, but only if the old ID value in the Attribute Buffer is different than the Polygon ID of the new polygon, so no edges are drawn between connected or overlapping polygons with same ID values.
Edge Marking is applied ONLY to opaque polygons (including wire-frames).
Edge Marking increases the size of opaque polygons (see notes below).
Edge Marking doesn't work very well with Anti-Aliasing (see Anti-Aliasing).
Technically, when rendering a polygon, it's edges (ie. the wire-frame region) are flagged as possible-edges (but it's still rendered normally, without using the edge-color). Once when all opaque polygons (*) have been rendered, the edge color is applied to these flagged pixels, under following conditions: At least one of the four surrounding pixels (up, down, left, right) must have different polygon_id than the edge, and, the edge depth must be LESS than the depth of that surrounding pixel (ie. no edges are rendered if the depth is GREATER or EQUAL, even if the polygon_id differs). At the screen borders, edges seem to be rendered in respect to the rear-plane's polygon_id entry (see Port 4000350h).
(*) Actually, edge-marking is reportedly performed not until all opaque AND translucent polygons have been rendered. That brings up some effects/problems when edges are covered by translucent polys: The edge-color is probably drawn as is (ie. it'll overwrite the translucent color, rather than being blended with the translucent color). And, any translucent polygons that do update the depth buffer will cause total edge-marking malfunction (since edge-marking involves the comparision of the current/surrounding pixel's depth values).
4000358h - FOG_COLOR - Fog Color (W)
Fog can be used to let more distant polygons to disappear in foggy grayness (or in darkness, or other color). This is particulary useful to "hide" the far clip plane. Fog can be enabled in DISP3DCNT.Bit7, moreover, when enabled, it can be activated or deactivated per polygon (POLYGON_ATTR.Bit15), and per Rear-plane (see there).

      0-4    Fog Color, Red     ;\
      5-9    Fog Color, Green   ; used only when DISP3DCNT.Bit6 is zero
      10-14  Fog Color, Blue    ;/
      15     Not used
      16-20  Fog Alpha          ;-used no matter of DISP3DCNT.Bit6
      21-31  Not used

Whether or not fog is applied to a pixel depends on the Fog flag in the framebuffer, the initial value of that flag can be defined in the rear-plane. When rendering opaque pixels, the framebuffer's fog flag gets replaced by PolygonAttr.Bit15. When rendering translucent pixels, the old flag in the framebuffer gets ANDed with PolygonAttr.Bit15.
400035Ch - FOG_OFFSET - Fog Depth Offset (W)

      0-14   Fog Offset (Unsigned) (0..7FFFh)
      15-31  Not used

FogDepthBoundary[0..31] (for FogDensity[0..31]) are defined as:

      FogDepthBoundary[n] = FOG_OFFSET + FOG_STEP*(n+1)   ;with n = 0..31

Whereas FOG_STEP is derived from the FOG_SHIFT value in DISP3DCNT.Bit8-11 (FOG_STEP=400h shr FOG_SHIFT) (normally FOG_SHIFT should be 0..10 (bigger shift amounts of 11..15 would cause FOG_STEP to become zero, so only Density[0] and Density[31] would be used).
The meaning of the depth values depends on whether z-values or w-values are stored in the framebuffer (see SwapBuffers.Bit1).
For translucent polygons, the depth value (and therefore: the amount of fog) depends on the depth update bit (see PolygonAttr.Bit11).
4000360h..37Fh - FOG_TABLE - Fog Density Table (W)
This 32-byte region contains FogDensity[0..31] (used at FogDepthBoundary[n]),

      0-6    Fog Density (00h..7Fh = None..Full) (usually increasing values)
      7      Not used

FogDensity[0] is used for all pixels closer than FogDepthBoundary[0], FogDensity[31] is used for all pixels more distant than FogDepthBoundary[0].
Density is linear interpolated for pixels that are between two Density depth boundaries. The formula for Fog Blending is:

      FrameBuffer[R] = (FogColor[R]*Density + FrameBuffer[R]*(128-Density)) / 128
      FrameBuffer[G] = (FogColor[G]*Density + FrameBuffer[G]*(128-Density)) / 128
      FrameBuffer[B] = (FogColor[B]*Density + FrameBuffer[B]*(128-Density)) / 128
      FrameBuffer[A] = (FogColor[A]*Density + FrameBuffer[A]*(128-Density)) / 128

If DISP3DCNT.Bit6 is set (=Alpha Only), then only FrameBuffer[A] is updated, and FrameBuffer[RGB] are kepth unchanged. Density=127 is handled as if Density=128.
Fog Glitch: The fog_alpha value appears to be ignored (treated as fog_alpha=1Fh) in the region up to the first density boundary. However, normally that value will be multiplied by zero (assumung that density[0] is usually zero), so you won't ever notice that hardware glitch.
Alpha-Blending (Polygon vs FrameBuffer)
Alpha-Blending occurs for pixels of translucent polygons,

      FrameBuf[R] = (Poly[R]*(Poly[A]+1) + FrameBuf[R]*(31-(Poly[A])) / 32
      FrameBuf[G] = (Poly[G]*(Poly[A]+1) + FrameBuf[G]*(31-(Poly[A])) / 32
      FrameBuf[B] = (Poly[B]*(Poly[A]+1) + FrameBuf[B]*(31-(Poly[A])) / 32
      FrameBuf[A] = max(Poly[A],FrameBuf[A])

There are three situations in which Alpha-Blending is bypassed (the old Framebuf[R,G,B,A] value is then simply overwritten by Poly[R,G,B,A]):

      1) Alpha-Blending is disabled                       (DISP3DCNT.Bit3=0)
      2) The polygon pixel is opaque                      (Poly[A]=31)
      3) The old framebuffer value is totally transparent (FrameBuf[A]=0)

The third case can happen if the rear-plane was initialized with Alpha=0, which causes the polygon not to be blended with the rear-plane (which may give better results when subsequently blending the 3D layer with the 2D engine).
Note: Totally transparent pixels (with Poly[A]=0) are not rendered (ie. neither FrameBuf[R,G,B,A] nor FrameBuf[Depth,Fog,PolyID,etc.] are updated.
Anti-Aliasing
Anti-Aliasing can be enabled in DISP3DCNT, when enabled, the edges of opaque polygons will be anti-aliased (ie. the pixels at the edges may become translucent).
Anti-Aliasing is not applied on translucent polygons. And, Anti-Aliasing is not applied on the interiors of the poylgons (eg. an 8x8 chessboard texture will be anti-aliased only at the board edges, not at the edges of the 64 fields).
Anti-Aliasing is (accidently) applied to opaque 1dot polygongs, line-segments and wire-frames (which results in dirty lines with missing pixels, 1dot polys become totally invisible), workaround is to use translucent dots, lines and wires (eg. with alpha=30).
Anti-Aliasing is (correctly) not applied to edges of Edge-Marked polygons, in that special case even opaque line-segments and wire-frames are working even if anti-aliasing is enabled (provided that they are edge-marked, ie. if their polygon ID differs from the framebuffer's ID).
Anti-Aliasing is (accidently) making the edges of Edge-Marked polygons translucent (with alpha=16 or so?), that reduces the contrast of the edge colors. Moreover, if two of these translucent edges do overlap, then they are blended twice (even if they have the same polygon_id, and even if the depth_update bit in polygon_attr is set; both should normally prevent double-blending), that scatters the brightness of such edges.
Polygon Size
In some cases, the NDS hardware doesn't render the lower/right edges of certain polygons. That feature reduces rendering load, and, when rendering connected polygons (eg. strips), then it'd be unnecessary to render that edges (since they'd overlap with the upper/left edges of the other polygon). On the contrary, if there's no connected polygon displayed, then the polygon may appear smaller than expected. Small polygons with excluded edges are:

      Opaque polygons (except wire-frames) without Edge-Marking and Anti-Aliasing,
      and, all polygons with vertical right-edges (except line-segments).
      Plus, Translucent Polys when Alpha-Blending is disabled in DISP3DCNT.Bit3.

All other polygons are rendered at full size with all edges included (except vertical right edges). Note: To disable the small-polygon feature, you can enable edge-marking (which does increase the polygon size, even if no edges are drawn, ie. even if all polys do have the same ID).

DS 3D Status

4000600h - GXSTAT - Geometry Engine Status Register (R and R/W)
Bit 30-31 are R/W. Writing "1" to Bit15 does reset the Error Flag (Bit15), and additionally resets the Projection Stack Pointer (Bit13), and probably (?) also the Texture Stack Pointer. All other GXSTAT bits are read-only.

      0     BoxTest,PositionTest,VectorTest Busy (0=Ready, 1=Busy)
      1     BoxTest Result  (0=All Outside View, 1=Parts or Fully Inside View)
      2-7   Not used
      8-12  Position & Vector Matrix Stack Level (0..31) (lower 5bit of 6bit value)
      13    Projection Matrix Stack Level        (0..1)
      14    Matrix Stack Busy (0=No, 1=Yes; Currently executing a Push/Pop command)
      15    Matrix Stack Overflow/Underflow Error (0=No, 1=Error/Acknowledge/Reset)
      16-24 Number of 40bit-entries in Command FIFO  (0..256)
     (24)   Command FIFO Full (MSB of above)  (0=No, 1=Yes; Full)
      25    Command FIFO Less Than Half Full  (0=No, 1=Yes; Less than Half-full)
      26    Command FIFO Empty                (0=No, 1=Yes; Empty)
      27    Geometry Engine Busy (0=No, 1=Yes; Busy; Commands are executing)
      28-29 Not used
      30-31 Command FIFO IRQ (0=Never, 1=Less than half full, 2=Empty, 3=Reserved)

When GXFIFO IRQ is enabled (setting 1 or 2), the IRQ flag (IF.Bit21) is set while and as long as the IRQ condition is true (and attempts to acknowledge the IRQ by writing to IF.Bit21 have no effect). So that, the IRQ handler must either fill the FIFO, or disable the IRQ (setting 0), BEFORE trying to acknowledge the IRQ.
4000604h - RAM_COUNT - Polygon List & Vertex RAM Count Register (R)

      0-11   Number of Polygons currently stored in Polygon List RAM (0..2048)
      12-15  Not used
      16-28  Number of Vertices currently stored in Vertex RAM       (0..6144)
      13-15  Not used

If a SwapBuffers command has been sent, then the counters are reset 10 cycles (at 33.51MHz clock) after next VBlank.
4000320h - RDLINES_COUNT - Rendered Line Count Register (R)
Rendering starts in scanline 214, the rendered lines are stored in a buffer that can hold up to 48 scanlines. The actual screen output begins after scanline 262, the lines are then read from the buffer and sent to the display. Simultaneously, the rendering engine keeps writing new lines to the buffer (ideally at the same speed than display output, so the buffer would always contain 48 pre-calculated lines).

      0-5    Minimum Number (minus 2) of buffered lines in previous frame (0..46)
      6-31   Not used

If rendering becomes slower than the display output, then the number of buffered lines decreases. Smaller values in RDLINES indicate that additional load to the rendering engine may cause buffer underflows in further frames, if so, the program should reduce the number of polygons to avoid display glitches.
Even if RDLINES becomes zero, it doesn't indicate whether actual buffer underflows have occured or not (underflows are indicated in DISP3DCNT Bit12).

DS 3D Tests

40005C0h - Cmd 70h - BOX_TEST - Test if Cuboid Sits inside View Volume (W)
The BoxTest result indicates if one or more of the 6 faces of the box are fully or parts of inside of the view volume. Can be used to reduce unnecessary overload, ie. if the result is false, then the program can skip drawing of objects which are inside of the box.
BoxTest verifies only if the faces of the box are inside view volume, and so, it will return false if the whole view volume is located inside of the box (still objects inside of the box may be inside of view).

      Parameter 1, Bit 0-15   X-Coordinate
      Parameter 1, Bit 16-31  Y-Coordinate
      Parameter 2, Bit 0-15   Z-Coordinate
      Parameter 2, Bit 16-31  Width  (presumably: X-Offset?)
      Parameter 3, Bit 0-15   Height (presumably: Y-Offset?)
      Parameter 3, Bit 16-31  Depth  (presumably: Z-Offset?)
      All values are 1bit sign, 3bit integer, 12bit fractional part

The result of the "coordinate+offset" additions should not overflow 16bit vertex coordinate range (1bit sign, 3bit integer, 12bit fraction).
Before using BoxTest, be sure that far-plane-intersecting & 1-dot polygons are enabled, if they aren't: Send the PolygonAttr command (with bit12,13 set to enable them), followed by dummy Begin and End commands (required to apply the new PolygonAttr settings). BoxTest should not be issued within Begin/End.
After sending the BoxTest command, wait until GXSTAT.Bit0 indicates Ready, then read the result from GXSTAT.Bit1.
40005C4h - Cmd 71h - POS_TEST - Set Position Coordinates for Test (W)

      Parameter 1, Bit 0-15   X-Coordinate
      Parameter 1, Bit 16-31  Y-Coordinate
      Parameter 2, Bit 0-15   Z-Coordinate
      Parameter 2, Bit 16-31  Not used
      All values are 1bit sign, 3bit integer, 12bit fractional part.

Multiplies the specified line-vector (x,y,z,1) by the clip coordinate matrix.
After sending the command, wait until GXSTAT.Bit0 indicates Ready, then read the result from POS_RESULT registers. POS_TEST can be issued anywhere (except within polygon strips, huh?).
Caution: POS_TEST overwrites the internal VTX registers, so the next vertex should be <fully> defined by VTX_10 or VTX_16, otherwise, when using VTX_XY, VTX_XZ, VTX_YZ, or VTX_DIFF, then the new vertex will be relative to the POS_TEST coordinates (rather than to the previous vertex).
4000620h..62Fh - POS_RESULT - Position Test Results (R)
This 16-byte region (4 words) contains the resulting clip coordinates (x,y,z,w) from the POS_TEST command. Each value is 1bit sign, 19bit integer, 12bit fractional part.
40005C8h - Cmd 72h - VEC_TEST - Set Directional Vector for Test (W)

      Parameter 1, Bit 0-9    X-Component
      Parameter 1, Bit 10-19  Y-Component
      Parameter 1, Bit 20-29  Z-Component
      Parameter 1, Bit 30-31  Not used
      All values are 1bit sign, 9bit fractional part.

Multiplies the specified line-vector (x,y,z,0) by the directional vector matrix. Similar as for the NORMAL command, it does require Matrix Mode 2 (ie. Position & Vector Simultaneous Set mode).
After sending the command, wait until GXSTAT.Bit0 indicates Ready, then read the result ("the directional vector in the View coordinate space") from VEC_RESULT registers.
4000630h..635h - VEC_RESULT - Vector Test Results (R)
This 6-byte region (3 halfwords) contains the resulting vector (x,y,z) from the VEC_TEST command. Each value is 4bit sign, 0bit integer, 12bit fractional part. The 4bit sign is either 0000b (positive) or 1111b (negative).
There is no integer part, so values >=1.0 or <-1.0 will cause overflows.
(Eg. +1.0 aka 1000h will be returned as -1.0 aka F000h due to overflow and sign-expansion).

DS 3D Rear-Plane

Other docs seem to refer to this as Clear-plane, rather than Rear-plane, anyways, the plane can be an image, so it isn't always "cleared".
The view order is as such:

      --> 2D Layers --> 3D Polygons --> 3D Rear-plane --> 2D Layers --> 2D Backdrop

The rear-plane can be disabled (by making it transparent; alpha=0), so that the 2D layers become visible as background.
2D layers can be moved in front of, or behind the 3D layer-group (which is represented as BG0 to the 2D Engine), 2D layers behind BG0 can be used instead of, or additionally to the rear-plane.
The rear-plane can be initialized via below two registers (so all pixels in the plane have the same colors and attributes), this method is used when DISP3DCNT.14 is zero:
4000350h - CLEAR_COLOR - Clear Color Attribute Register (W)

      0-4    Clear Color, Red
      5-9    Clear Color, Green
      10-14  Clear Color, Blue
      15     Fog (enables Fog to the rear-plane) (doesn't affect Fog of polygons)
      16-20  Alpha
      21-23  Not used
      24-29  Clear Polygon ID (affects edge-marking, at the screen-edges?)
      30-31  Not used

4000354h - CLEAR_DEPTH - Clear Depth Register (W)

      0-14   Clear Depth (0..7FFFh) (usually 7FFFh = most distant)
      15     Not used
      16-31  See Port 4000356h, CLRIMAGE_OFFSET

The 15bit Depth is expanded to 24bit as "X=(X*200h)+((X+1)/8000h)*1FFh".
Rear Color/Depth Bitmaps
Alternately, the rear-plane can be initialized by bitmap data (allowing to assign different colors & attributes to each pixel), this method is used when DISP3DCNT.14 is set:
Consists of two bitmaps (one with color data, one with depth data), each containing 256x256 16bit entries, and so, each occupying a whole 128K slot,

      Rear Color Bitmap (located in Texture Slot 2)
        0-4    Clear Color, Red
        5-9    Clear Color, Green
        10-14  Clear Color, Blue
        15     Alpha (0=Transparent, 1=Solid) (equivalent to 5bit-alpha 0 and 31)
      Rear Depth Bitmap (located in Texture Slot 3)
        0-14   Clear Depth, expanded to 24bit as X=(X*200h)+((X+1)/8000h)*1FFh
        15     Clear Fog (Initial fog enable value)

This method requires VRAM to be allocated to Texture Slot 2 and 3 (see Memory Control chapter). Of course, in that case the VRAM is used as Rear-plane, and cannot be used for Textures.
The bitmap method is restricted to 1bit alpha values (the register-method allows to use a 5bit alpha value).
The Clear Polygon ID is kept defined in the CLEAR_COLOR register, even in bitmap mode.
4000356h - CLRIMAGE_OFFSET - Rear-plane Bitmap Scroll Offsets (W)
The visible portion of the bitmap is 256x192 pixels (regardless of the viewport setting, which is used only for polygon clipping). Internally, the bitmap is 256x256 pixels, so the bottom-most 64 rows are usually offscreen, unless scrolling is used to move them into view.

      Bit0-7   X-Offset (0..255; 0=upper row of bitmap)
      Bit8-14  Y-Offset (0..255; 0=left column of bitmap)

The bitmap wraps to the upper/left edges when exceeding the lower/right edges.

DS 3D Final 2D Output

The final 3D image (consisting of polygons and rear-plane) is passed to 2D Engine A as BG0 layer (provided that DISPCNT is configured to use 3D as BG0).
Scrolling
The BG0HOFS register (4000010h) can be used the scroll the 3D layer horizontally, the scroll region is 512 pixels, consisting of 256 pixels for the 3D image, followed by 256 transparent pixels, and then wrapped to the 3D image again. Vertical scrolling (and rotation/scaling) cannot be used on the 3D layer.
BG Priority Order
The lower 2bit of the BG0CNT register (4000008h) control the priority relative to other BGs and OBJs, so the 3D layer can be in front of or behind 2D layers. All other bits in BG0CNT have no effect on 3D, namely, mosaic cannot be used on the 3D layer.
Special Effects
Special Effects Registers (4000050h..54h) can be used as such:

      Brightness up/down with BG0 as 1st Target via EVY   (as for 2D)
      Blending with BG0 as 2nd Target via EVA/EVB         (as for 2D)
      Blending with BG0 as 1st Target via 3D Alpha-values (unlike as for 2D)

The latter method probably (?) uses per-pixel 3D alpha values as such: EVA=A/2, and EVB=16-A/2, without using the EVA/EVB settings in 4000052h.
Window Feature
Window Feature (4000040h..4Bh) can be used as for 2D.
"If the 3D screen has highest priority, then alpha-blending is always enabled, regardless of the Window Control register's color effect enable flag [ie. regardless of Bit5 of WIN0IN, WIN1IN, WINOBJ, WINOUT registers]"... not sure if that is true, and if it superseedes the effect selection in Port 4000050h...?

DS Sound

DS Sound Hardware
The DS contains 16 hardware sound channels.
The console contains two speakers, arranged left and right of the upper screen, and so, provides stereo sound even without using the headphone socket.
DS Sound Channels 0..15
DS Sound Control Registers
DS Sound Capture
DS Sound Block Diagrams
DS Sound Notes
DS Sound Files
DS Files - Sound (SDAT etc.)
Power control
When restoring power supply to the sound circuit, do not output any sound during the first 15 milliseconds.

DS Sound Channels 0..15

Each of the 16 sound channels occopies 16 bytes in the I/O region, starting with channel 0 at 4000400h..400040Fh, up to channel 15 at 40004F0h..40004FFh.
40004x0h - NDS7 - SOUNDxCNT - Sound Channel X Control Register (R/W)

      Bit0-6    Volume Mul   (0..127=silent..loud)
      Bit7      Not used     (always zero)
      Bit8-9    Volume Div   (0=Normal, 1=Div2, 2=Div4, 3=Div16)
      Bit10-14  Not used     (always zero)
      Bit15     Hold         (0=Normal, 1=Hold last sample after one-shot sound)
      Bit16-22  Panning      (0..127=left..right) (64=half volume on both speakers)
      Bit23     Not used     (always zero)
      Bit24-26  Wave Duty    (0..7) ;HIGH=(N+1)*12.5%, LOW=(7-N)*12.5% (PSG only)
      Bit27-28  Repeat Mode  (0=Manual, 1=Loop Infinite, 2=One-Shot, 3=Prohibited)
      Bit29-30  Format       (0=PCM8, 1=PCM16, 2=IMA-ADPCM, 3=PSG/Noise)
      Bit31     Start/Status (0=Stop, 1=Start/Busy)

All channels support ADPCM/PCM formats, PSG rectangular wave can be used only on channels 8..13, and white noise only on channels 14..15.
40004x4h - NDS7 - SOUNDxSAD - Sound Channel X Data Source Register (W)

      Bit0-26  Source Address (must be word aligned, bit0-1 are always zero)
      Bit27-31 Not used

40004x8h - NDS7 - SOUNDxTMR - Sound Channel X Timer Register (W)

      Bit0-15  Timer Value, Sample frequency, timerval=-(33513982Hz/2)/freq

The PSG Duty Cycles are composed of eight "samples", and so, the frequency for Rectangular Wave is 1/8th of the selected sample frequency.
For PSG Noise, the noise frequency is equal to the sample frequency.
40004xAh - NDS7 - SOUNDxPNT - Sound Channel X Loopstart Register (W)

      Bit0-15  Loop Start, Sample loop start position
               (counted in words, ie. N*4 bytes)

40004xCh - NDS7 - SOUNDxLEN - Sound Channel X Length Register (W)
The number of samples for N words is 4*N PCM8 samples, 2*N PCM16 samples, or 8*(N-1) ADPCM samples (the first word containing the ADPCM header). The Sound Length is not used in PSG mode.

      Bit0-21  Sound length (counted in words, ie. N*4 bytes)
      Bit22-31 Not used

Minimum length (the sum of PNT+LEN) is 4 words (16 bytes), smaller values (0..3 words) are causing hang-ups (busy bit remains set infinite, but no sound output occurs).
In One-shot mode, the sound length is the sum of (PNT+LEN).
In Looped mode, the length is (1*PNT+Infinite*LEN), ie. the first part (PNT) is played once, the second part (LEN) is repeated infinitely.

DS Sound Control Registers

4000500h - NDS7 - SOUNDCNT - Sound Control Register (R/W)

      Bit0-6   Master Volume       (0..127=silent..loud)
      Bit7     Not used            (always zero)
      Bit8-9   Left Output from    (0=Left Mixer, 1=Ch1, 2=Ch3, 3=Ch1+Ch3)
      Bit10-11 Right Output from   (0=Right Mixer, 1=Ch1, 2=Ch3, 3=Ch1+Ch3)
      Bit12    Output Ch1 to Mixer (0=Yes, 1=No) (both Left/Right)
      Bit13    Output Ch3 to Mixer (0=Yes, 1=No) (both Left/Right)
      Bit14    Not used            (always zero)
      Bit15    Master Enable       (0=Disable, 1=Enable)
      Bit16-31 Not used            (always zero)

4000504h - NDS7 - SOUNDBIAS - Sound Bias Register (R/W)

      Bit0-9   Sound Bias    (0..3FFh, usually 200h)
      Bit10-31 Not used      (always zero)

After applying the master volume, the signed left/right audio signals are in range -200h..+1FFh (with medium level zero), the Bias value is then added to convert the signed numbers into unsigned values (with medium level 200h).
BIAS output is always enabled, even when Master Enable (SOUNDCNT.15) is off.
The sampling frequency of the mixer is 1.04876 MHz with an amplitude resolution of 24 bits, but the sampling frequency after mixing with PWM modulation is 32.768 kHz with an amplitude resolution of 10 bits.

DS Sound Capture

The DS contains 2 built-in sound capture devices that can capture output waveform data to memory.
Sound capture 0 can capture output from left-mixer or output from channel 0.
Sound capture 1 can capture output from right-mixer or output from channel 2.
4000508h - NDS7 - SNDCAP0CNT - Sound Capture 0 Control Register (R/W)
4000509h - NDS7 - SNDCAP1CNT - Sound Capture 1 Control Register (R/W)

      Bit0     Control of Associated Sound Channels (ANDed with Bit7)
                SNDCAP0CNT: Output Sound Channel 1 (0=As such, 1=Add to Channel 0)
                SNDCAP1CNT: Output Sound Channel 3 (0=As such, 1=Add to Channel 2)
                Caution: Addition mode works only if BOTH Bit0 and Bit7 are set.
      Bit1     Capture Source Selection
                SNDCAP0CNT: Capture 0 Source (0=Left Mixer, 1=Channel 0/Bugged)
                SNDCAP1CNT: Capture 1 Source (0=Right Mixer, 1=Channel 2/Bugged)
      Bit2     Capture Repeat        (0=Loop, 1=One-shot)
      Bit3     Capture Format        (0=PCM16, 1=PCM8)
      Bit4-6   Not used              (always zero)
      Bit7     Capture Start/Status  (0=Stop, 1=Start/Busy)

4000510h - NDS7 - SNDCAP0DAD - Sound Capture 0 Destination Address (R/W)
4000518h - NDS7 - SNDCAP1DAD - Sound Capture 1 Destination Address (R/W)

      Bit0-26  Destination address (word aligned, bit0-1 are always zero)
      Bit27-31 Not used (always zero)

Capture start address (also used as re-start address for looped capture).
4000514h - NDS7 - SNDCAP0LEN - Sound Capture 0 Length (W)
400051Ch - NDS7 - SNDCAP1LEN - Sound Capture 1 Length (W)

      Bit0-15  Buffer length (1..FFFFh words) (ie. N*4 bytes)
      Bit16-31 Not used

Minimum length is 1 word (attempts to use 0 words are interpreted as 1 word).
SOUND1TMR - NDS7 - Sound Channel 1 Timer shared as Capture 0 Timer
SOUND3TMR - NDS7 - Sound Channel 3 Timer shared as Capture 1 Timer
There are no separate capture frequency registers, instead, the sample frequency of Channel 1/3 is shared for Capture 0/1. These channels are intended to output the captured data, so it makes sense that both capture and sound output use the same frequency.
For Capture 0, a=0, b=1, x=0.
For Capture 1, a=2, b=3, x=1.
Capture Bugs
The NDS contains two hardware bugs which do occur when capturing data from ch(a) (SNDCAPxCNT.Bit1=1), if so, either bug occurs depending on whether ch(a)+ch(b) addition is enabled or disabled (SNDCAPxCNT.Bit0).

      1) Both Negative Bug - SNDCAPxCNT Bit1=1, Bit0=0 (addition disabled)
       Capture data is accidently set to -8000h if ch(a) and ch(b) are both <0.
       Otherwise the correct capture result is returned, ie. plain ch(a) data,
       not being affected by ch(b) (since addition is disabled).
       Workaround: Ensure that ch(a) and/or ch(b) are >=0 (or disabled).
     2) Overflow Bug - SNDCAPxCNT Bit1=1, Bit0=1 (addition enabled)
       In this mode, Capture data isn't clipped to MinMax(-8000h,+7FFFh),
       instead, it is ANDed with FFFFh, so the sign bit is lost if the
       addition result ch(a)+ch(b) is less/greater than -8000h/+7FFFh.
       Workaround: Reduce ch(a)/ch(b) volume or data to avoid overflows.

These bugs occur only for capture (speaker output remains intact), and they occur only when capturing ch(a) (capturing mixer-output works flawless).
ch(a)+ch(b) Channel Addition
The ch(a)+ch(b) addition unit has 2 outputs, with slightly different results:

     1) Addition Result for Capture(x) when using capture source=ch(a):
      Addition is performed always, no matter of SOUNDCNT.Bit12/13.
      And, no matter of ch(a) enable, result is plain ch(b) if ch(a) is disabled.
      Result is 16bit (plus fraction) with overflow error (see Capture Bugs).
     2) Addition Result for Mixer (towards speakers, and capture source=mixer):
      Ch(b) is muted if ch(a) is disabled.
      Ch(b) is muted if ch(b) SOUNDCNT.Bit12/13 is set to "Ch(b) not to mixer".
      Result is 17bit (plus fraction) without overflow error.

Addition mode can be used only if the <corresponding> capture unit is enabled, ie. if SNDCAPxCNT (Bit0 AND Bit7)=1. If so, addition affects both mixers (and so, may also affect the <other> capture unit if it reads from mixer).

DS Sound Block Diagrams

Left Mixer with Capture 0
(Right Mixer with Capture 1, respectively)

                           _____
      Ch0.L ------------->|     |  .------------------------------> to Capture 0
                   ___    |     |  |                  ___
      Ch1.L ---o->|Sel|-->|     |  |       Ch0..Ch15 |   |
               |  |___|   |Left |--o---------------->|   |
      Ch2.L ---|--------->|Mixer|                    |Sel|   ______    ____
               |   ___    |     |                Ch1 |   |  |Master|  |Add |
      Ch3.L -o-|->|Sel|-->|     | .----------------->|   |->|Volume|->|Bias|-> L
             | |  |___|   |     | |                  |   |  |______|  |____|
      Ch4.L -|-|--------->|     | |              Ch3 |   |
      ...   -|-|--------->|     | | .--------------->|   |
      Ch15.L-|-|--------->|_____| | |   ___          |   |
             | '------------------o-|->|Add| Ch1+Ch3 |   |
             '----------------------o->|___|-------->|___|

Channel 0 and 1, Capture 0 with input from Left Mixer
(Channel 2 and 3, Capture 1 with input from Right Mixer, respectively)

      ____     _________     ___     ___      ___
     |FIFO|-->|Channel 0|-->|Vol|-->|Add|-o->|Pan|--> Ch0.L
     |____|   |_________|   |___|   |___| |  |___|--> Ch0.R
      ____     _________     ___      ^   |
     |FIFO|<--|Capture 0|<--|Sel|<----|---'
     |____|   |_ _____ _|   |___|<----|-------------- Left Mixer
      ____     _:Timer:_     ___     _|_      ___
     |FIFO|-->|Channel 1|-->|Vol|-->|Sel|--->|Pan|--> Ch1.L
     |____|   |_________|   |___|   |___|    |___|--> Ch1.R

Channel 4 (Channel 5..15, respectively)

      ____     _________     ___              ___
     |FIFO|-->|Channel 4|-->|Vol|----------->|Pan|--> Ch4.L
     |____|   |_________|   |___|            |___|--> Ch4.R

The FIFO isn't used in PSG/Noise modes (supported on channel 8..15).

DS Sound Notes

Sound delayed Start/Restart (timing glitch)
A sound will be started/restarted when changing its start bit from 0 to 1, however, the sound won't start immediately: PSG/Noise starts after 1 sample, PCM starts after 3 samples, and ADPCM starts after 11 samples (3 dummy samples as for PCM, plus 8 dummy samples for the ADPCM header).
Sound Stop (timing note)
In one-shot mode, the Busy bit gets cleared automatically at the BEGIN of the last sample period, nethertheless (despite of the cleared Busy bit) the last sample is kept output until the END of the last sample period (or, if the Hold flag is set, then the last sample is kept output infinitely, that is, until Hold gets cleared, or until the sound gets restarted).
Hold Flag (appears useless/bugged)
The Hold flag allows to keep the last sample being output infinitely after the end of one-shot sounds. This feature is probably intended to allow to play two continous one-shot sound blocks (without producing any scratch noise upon small delays between both blocks, which would occur if the output level would drop to zero).
However, the feature doesn't work as intended. As described above, PCM8/PCM16 sound starts are delayed by 3 samples. With Hold flag set, old output level is acually kept intact during the 1st sample, but the output level drops to zero during 2nd-3rd sample, before starting the new sound in 4th sample.
7bit Volume and Panning Values

      data.vol   = data*N/128
      pan.left   = data*(128-N)/128
      pan.right  = data*N/128
      master.vol = data*N/128/64

Register settings of 0..126,127 are interpreted as N=0..126,128.
Max Output Levels
When configured to max volume (and left-most or right-most panning), each channel can span the full 10bit output range (-200h..1FFh) on one speaker, as well as the full 16bit input range (-8000h..7FFFh) on one capture unit.
(It needs 2 channels to span the whole range on BOTH speakers/capture units.)
Together, all sixteen channels could thus reach levels up to -1E00h..21F0h (with default BIAS=200h) on one speaker, and -80000h..+7FFF0h on one capture unit. However, to avoid overflows, speaker outputs are clipped to MinMax(0,3FFh), and capture inputs to MinMax(-8000h..+7FFFh).
Channel/Mixer Bit-Widths

      Step                           Bits  Min        Max
      0 Incoming PCM16 Data          16.0  -8000h     +7FFFh
      1 Volume Divider (div 1..16)   16.4  -8000h     +7FFFh
      2 Volume Factor (mul N/128)    16.11 -8000h     +7FFFh
      3 Panning (mul N/128)          16.18 -8000h     +7FFFh
      4 Rounding Down (strip 10bit)  16.8  -8000h     +7FFFh
      5 Mixer (add channel 0..15)    20.8  -80000h    +7FFF0h
      6 Master Volume (mul N/128/64) 14.21 -2000h     +1FF0h
      7 Strip fraction               14.0  -2000h     +1FF0h
      8 Add Bias (0..3FFh, def=200h) 15.0  -2000h+0   +1FF0h+3FFh
      9 Clip (min/max 0h..3FFh)      10.0  0          +3FFh

Table shows integer.fractional bits, and min/max values (without fraction).
Capture Clipping/Rounding
Incoming ch(a) is NOT clipped, ch(a)+ch(b) may overflow (see Capture Bugs).
Incoming mixer data (20.8bits) is clipped to 16.8bits (MinMax -8000h..7FFFh).
For PCM8 capture format, the 16.8 bits are divided by 100h (=8.16 bits).
If the MSB of the fractional part is set, then data is rounded towards zero.
(Positive values are rounded down, negative values are rounded up.)
The fractional part is then discarded, and plain integer data is captured.
PSG Sound
The output volume equals to PCM16 values +7FFFh (HIGH) and -7FFFh (LOW).
PSG sound is always Infinite (the SOUNDxLEN Register, and the SOUNDxCNT Repeat Mode bits have no effect). The PSG hardware doesn't support sound length, sweep, or volume envelopes, however, these effects can be produced by software with little overload (or, more typically, with enormous overload, depending on the programming language used).
PSG Wave Duty (channel 8..13 in PSG mode)
Each duty cycle consists of eight HIGH or LOW samples, so the sound frequency is 1/8th of the selected sample rate. The duty cycle always starts at the begin of the LOW period when the sound gets (re-)started.

      0  12.5% "_______-_______-_______-"
      1  25.0% "______--______--______--"
      2  37.5% "_____---_____---_____---"
      3  50.0% "____----____----____----"
      4  62.5% "___-----___-----___-----"
      5  75.0% "__------__------__------"
      6  87.5% "_-------_-------_-------"
      7   0.0% "________________________"

The Wave Duty bits exist and are read/write-able on all channels (although they are actually used only in PSG mode on channels 8-13).
PSG Noise (channel 14..15 in PSG mode)
Noise randomly switches between HIGH and LOW samples, the output levels are calculated, at the selected sample rate, as such:

      X=X SHR 1, IF carry THEN Out=LOW, X=X XOR 6000h ELSE Out=HIGH

The initial value when (re-)starting the sound is X=7FFFh. The formula is more or less same as "15bit polynomial counter" used on 8bit Gameboy and GBA.
PCM8 and PCM16
Signed samples in range -80h..+7Fh (PCM8), or -8000h..+7FFFh (PCM16).
The output volume of PCM8=NNh is equal to PCM16=NN00h.
IMA-ADPCM Format
IMA-ADPCM is a Adaptive Differential Pulse Code Modulation (ADPCM) variant, designed by International Multimedia Association (IMA), the format is used, among others, in IMA-ADPCM compressed Windows .WAV files.
The NDS data consist of a 32bit header, followed by 4bit values (so each byte contains two values, the first value in the lower 4bits, the second in upper 4 bits). The 32bit header contains initial values:

      Bit0-15   Initial PCM16 Value (Pcm16bit = -7FFFh..+7FFF) (not -8000h)
      Bit16-22  Initial Table Index Value (Index = 0..88)
      Bit23-31  Not used (zero)

In theory, the 4bit values are decoded into PCM16 values, as such:

      Diff = ((Data4bit AND 7)*2+1)*AdpcmTable[Index]/8      ;see rounding-error
      IF (Data4bit AND 8)=0 THEN Pcm16bit = Max(Pcm16bit+Diff,+7FFFh)
      IF (Data4bit AND 8)=8 THEN Pcm16bit = Min(Pcm16bit-Diff,-7FFFh)
      Index = MinMax (Index+IndexTable[Data4bit AND 7],0,88)

In practice, the first line works like so (with rounding-error):

      Diff = AdpcmTable[Index]/8
      IF (data4bit AND 1) THEN Diff = Diff + AdpcmTable[Index]/4
      IF (data4bit AND 2) THEN Diff = Diff + AdpcmTable[Index]/2
      IF (data4bit AND 4) THEN Diff = Diff + AdpcmTable[Index]/1

And, a note on the second/third lines (with clipping-error):

      Max(+7FFFh) leaves -8000h unclipped (can happen if initial PCM16 was -8000h)
      Min(-7FFFh) clips -8000h to -7FFFh (possibly unlike windows .WAV files?)

Whereas, IndexTable[0..7] = -1,-1,-1,-1,2,4,6,8. And AdpcmTable [0..88] =

      0007h,0008h,0009h,000Ah,000Bh,000Ch,000Dh,000Eh,0010h,0011h,0013h,0015h
      0017h,0019h,001Ch,001Fh,0022h,0025h,0029h,002Dh,0032h,0037h,003Ch,0042h
      0049h,0050h,0058h,0061h,006Bh,0076h,0082h,008Fh,009Dh,00ADh,00BEh,00D1h
      00E6h,00FDh,0117h,0133h,0151h,0173h,0198h,01C1h,01EEh,0220h,0256h,0292h
      02D4h,031Ch,036Ch,03C3h,0424h,048Eh,0502h,0583h,0610h,06ABh,0756h,0812h
      08E0h,09C3h,0ABDh,0BD0h,0CFFh,0E4Ch,0FBAh,114Ch,1307h,14EEh,1706h,1954h
      1BDCh,1EA5h,21B6h,2515h,28CAh,2CDFh,315Bh,364Bh,3BB9h,41B2h,4844h,4F7Eh
      5771h,602Fh,69CEh,7462h,7FFFh

The closest way to reproduce the AdpcmTable with 32bit integer maths appears:

      X=000776d2h, FOR I=0 TO 88, Table[I]=X SHR 16, X=X+(X/10), NEXT I
      Table[3]=000Ah, Table[4]=000Bh, Table[88]=7FFFh, Table[89..127]=0000h

When using ADPCM and loops, set the loopstart position to the data part, rather than the header. At the loop end, the SAD value is reloaded to the loop start location, additionally index and pcm16 values are reloaded to the values that have originally appeared at that location. Do not change the ADPCM loop start position during playback.
Microphone Input
For Microphone (and Touchscreen) inputs, see
DS Touch Screen Controller (TSC)

DS Sound Files - SDAT (Sound Data Archive)

SDAT Header

      000h 4     ID "SDAT"           ;alike "CSAR" on 3DS
      004h 2     Byte Order    (FEFFh)
      006h 2     Version       (0100h)
      008h 4     Total Filesize
      00Ch 2     Header Size (usually 40h)
      00Eh 2     Number of Blocks (usually 4 = SYMB+INFO+FAT+FILE) (or 3=no SYMB)
      010h 4+4   SYMB Block (Offset from SDAT+0, Size) ;=0,0 if above is 3=no SYMB
      018h 4+4   INFO Block (Offset from SDAT+0, Size) ;\
      020h 4+4   FAT  Block (Offset from SDAT+0, Size) ; always present
      028h 4+4   FILE Block (Offset from SDAT+0, Size) ;/
      030h 10h   Padding to 20h-byte boundary (0)

The SYMB block exists in most SDAT files (except in some titles like Downhill Jam and Over the Hedge).

     _________________________________ SYMB Block _________________________________

Symbol Block (if present) (names for the corresponding items in INFO block)

      000h 4     ID "SYMB"
      004h 4     SYMB Block Size (rounded up to 4-byte boundary, unlike as in SDAT)
      008h 4     File List SSEQ    (Offset from SYMB+0) Sequences (songs)
      00Ch 4     Folder List SSAR  (Offset from SYMB+0) Sequence Archives (fx)
      010h 4     File List BANK    (Offset from SYMB+0) Banks
      014h 4     File List SWAR    (Offset from SYMB+0) Wave Archives (samples)
      018h 4     File List Player  (Offset from SYMB+0) Player (Group-related)
      01Ch 4     File List Group   (Offset from SYMB+0) Group (SSEQ+SSAR+BANK+SWAR)
      020h 4     File List Player2 (Offset from SYMB+0) Player2 (Stream-related)
      024h 4     File List STRM    (Offset from SYMB+0) Wave Stream
      028h 18h   Reserved (0)
      040h ..    File/Folder Lists (see below)
      ..   ..    File/Folder Name Strings (ASCII, terminated by 0)
      ..   ..    Padding to 4-byte boundary (0)

File List's are having following format:

      000h 4       Number of entries in this list (can be 0=None)
      004h N*4     File Name (Offset from SYMB+0)

Folder List (for SSAR):

      000h 4       Number of entries in this list (can be 0=None)
      004h N*(4+4) SSAR "Folder Name" and SSEQ "File List" (Offset's from SYMB+0)

     _________________________________ INFO Block _________________________________

Info Block

      000h 4     ID "INFO"
      004h 4     INFO Block Size (same as in SDAT header)
      008h 4     Info List SSEQ    (Offset from INFO+0) Sequences (songs)
      00Ch 4     Info List SSAR    (Offset from INFO+0) Sequence Archives (fx)
      010h 4     Info List BANK    (Offset from INFO+0) Banks
      014h 4     Info List SWAR    (Offset from INFO+0) Wave Archives (samples)
      018h 4     Info List Player  (Offset from INFO+0) Player (Group-related)
      01Ch 4     Info List Group   (Offset from INFO+0) Group (SSEQ+SSAR+BANK+SWAR)
      020h 4     Info List Player2 (Offset from INFO+0) Player2 (Stream-related)
      024h 4     Info List STRM    (Offset from INFO+0) Wave Stream
      028h 18h   Reserved (0)
      ..   ..    Info Lists (see below)
      ..   ..    Info Entries (see below)
      ..   ..    Padding to 4-byte boundary (0)

Info List's are having following format:

      000h 4     Number of entries in this list (can be 0=None)
      004h N*4   Info Entries (Offset from INFO+0)

SSEQ Info Entry (Sequences, eg. songs)

      000h 2   FAT fileID of SSEQ file      ;for accessing this file
      002h 2   Unknown
      004h 2   bnk         ;Associated BANK
      006h 1   vol         ;Volume
      007h 1   cpr
      008h 1   ppr
      009h 1   ply
      00Ah 2   Unknown (0)

SSAR Info Entry (Sequence Archives, eg. collections of sound effects)

      000h 2   FAT fileID of SSAR file
      002h 2   unknown

Note: bnk/vol/cpr/ppr/ply is stored in the SSAR file (instead of in Info). The actual sequences are also in SSAR? Or does the SSAR contain pointers to SSEQ files?
BANK Info Entry (Banks)

      000h 2   FAT fileID of SBNK file
      002h 2   unknown
      004h 2   1st SWAR   ;\
      006h 2   2nd SWAR   ; Associated Wave Archives (FFFFh=Unused entry)
      008h 2   3rd SWAR   ;
      00Ah 2   4th SWAR   ;/

SWAR Info Entry (Wave Archives, eg. collections of instruments or effects)

      000h 2   FAT fileID of SWAR file
      002h 2   unknown

Player Info Entry (whatever)

      000h 1   Unknown
      001h 3   Padding
      004h 4   Unknown

Group Info Entry (whatever, list of files that must be loaded to memory?)

      000h 4       Number of items in this group
      004h N*(4+4) Array (with ID+Index pairs)

ID values: 700h=SSEQ, 803h=SSAR, 601h=BANK, 402h=SWAR.
Index: Entry number in the corresponding SSEQ/SSAR/BANK/SWAR list.
Player2 Info Entry (whatever, Stream related?)

      000h 1   nCount             ;number of USED entries in below array
      001h 16  v[16]              ;unknown array (UNUSED entries are set to FFh
      011h 7   Reserved (0)

STRM Info Entry

      000h 2   FAT fileID of STRM file    ;for accessing the file
      002h 2   Unknown
      004h 1   vol            ;volume
      005h 1   pri            ;priority?
      006h 1   ply            ;play?
      007h 5   Reserved (0)

     ____________________________ FAT and FILE Blocks _____________________________

FAT Block

      000h 4         ID "FAT "
      004h 4         FAT Block Size (same as in SDAT header) (0Ch+N*10h)
      008h 4         Number of files
      00Ch N*(4+4+8) File Entries (Offset from SDAT+0, Size, Zero)

The 8-byte Zero entries can be used for storing data at runtime.
File Block

      000h 4         ID "FILE"
      004h 4         FILE Block Size (same as in SDAT header)
      008h 4         Number of files (same as in FAT block)
      00Ch 4         Reserved (0)
      010h ..        Files (SSEQ,SSAR,SBNK,SWAR,STRM) (at offsets specified in FAT)

DS Sound Files - SSEQ (Sound Sequence)

It is a converted MIDI sequence. Linked to a BANK for instruments.
SSEQ is usually found inside of SDAT files (but also exists as standalone file, eg. 3DS Circle Pad Pro test/calib, RomFS:\extrapad_bcwav_LZ.bin\*.sseq, and 3DS Picture Picker, RomFS:\sound\csnd.LZ\*).
SSEQ Header

      000h 4     ID "SSEQ"                                  ;\
      004h 2     Byte Order    (FEFFh)                      ;
      006h 2     Version       (0100h)                      ; Main header
      008h 4     Total Filesize                             ;
      00Ch 2     Header Size (usually 10h)                  ;
      00Eh 2     Number of Blocks (usually 1 = DATA)        ;/
      010h 4     ID "DATA"                                  ;\
      014h 4     Total Filesize, minus 10h                  ; Sub header
      018h 4     Offset to data (from SSEQ+0) (1Ch)         ;/
      01Ch ..    Arrays of sequence data..                  ;-

NB. For the details of the SSEQ file, please refer to loveemu's sseq2mid
Description
A SSEQ can have at maximum 16 tracks, notes in the range of 0..127 (middle C is 60). Each quartet note has a fixed tick length of 48. Tempo in the range of 1..240 BPM (default is 120). The SSEQ will not be played correctly if tempo higher than 240.
The SEQ player uses ARM7's Timer1 for timing. The ARM7's 4 Timers runs at 33MHz (approximately 2^25). The SEQ player sets Timer1 reload value to 2728, prescaler to F/64. So on about every 0.0052 sec (64*2728/33MHz) the SEQ Player will be notified (1 cycle). As a quartet note has fixed tick value of 48, the highest tempo that SEQ Player can handle is 240 BPM (60/(0.0052*48)).
During each cycle, the SEQ player adds the tempo value to a variable. Then it checks if the value exceeds 240. If it does, the SEQ player subtracts 240 from the variable, and process the SSEQ file. Using this method, the playback is not very precise but the difference is too small to be noticed.
Take an example with tempo = 160 BPM, the SSEQ file is processed twice in 3 notifications.

      cycle  variable action
      1       0       Add 160
      2       160     Add 160
      3       320     Subtract 240, process once, add 160
      4       240     Subtract 240, process once, add 160
      5       160     Add 160
      6       320     Subtract 240, process once, add 160
      7       240     Subtract 240, process once, add 160
      8       160     Add 160

Events

      ID      Parameter             Description
      00h-7Fh Velocity: 1 byte [0..127]
              Duration: Variable Length
                                    NOTE-ON. Duration is expressed in tick.
                                    48 for quartet note.
                                    Usually it is NOT a multiple of 3.
      80h     Duration: Variable Length
                                    REST. It tells the SSEQ-sequencer to wait for
                                    a certain tick. Usually it is a multiple of 3.
      81h     Bank & Program Number:
              Variable Length
                                    bits[0..7] is the program number,
                                    bits[8..14] is the bank number.
                                    Bank change is seldomly found,
                                    so usually bank 0 is used.
      FEh     2 bytes Indicates which tracks are used.
              Bit0 for track 0, ... Bit15 for track 15.
              If the bit is set, the corresponding track is used.
                                    Indication begin of multitrack. Must be in the
                                    beginning of the first track to work. A series
                                    of event 0x93 follows.
      93h     4 bytes 1st byte is track number [0..15]
              The other 3 bytes are the relative adress of track data.
              Add nDataOffset (usually 0x1C) to find out the absolute address.
                                    SSEQ is similar to MIDI in that track data are
                                    stored one after one track. Unlike mod music.
      94h     JUMP Address: 3 bytes
              (Add nDataOffset (usually 0x1C) to find out the absolute address.)
                                    JUMP. A jump must be backward. So that the
                                    song will loop forever.
      95h     CALL Address: 3 bytes
              (Add nDataOffset (usually 0x1C) to find out the absolute address.)
      A0h-BFh See loveemu's sseq2mid for more details.
                                    Some arithmetic operations / comparions.
                                    Affect how SSEQ is to be played.
      C0h     1 byte  PAN                (0..127, middle is 64, uh?)
      C1h     1 byte  VOLUME             (0..127)
      C2h     1 byte  MASTER VOLUME      (0..127)
      C3h     1 byte  TRANSPOSE (Channel Coarse Tuning) (0..64 = 64..128 in MIDI)
      C4h     1 byte  PITCH BEND
      C5h     1 byte  PITCH BEND RANGE
      C6h     1 byte  TRACK PRIORITY
      C7h     1 byte  MONO/POLY          (0=Poly, 1=Mono)
      C8h     1 byte  TIE (unknown)      (0=Off, 1=On)
      C9h     1 byte  PORTAMENTO CONTROL
      CAh     1 byte  MODULATION DEPTH   (0=Off, 1=On)
      CBh     1 byte  MODULATION SPEED
      CCh     1 byte  MODULATION TYPE    (0=Pitch, 1=Volume, 2=Pan)
      CDh     1 byte  MODULATION RANGE
      CEh     1 byte  PORTAMENTO ON/OFF
      CFh     1 byte  PORTAMENTO TIME
      D0h     1 byte  ATTACK RATE
      D1h     1 byte  DECAY RATE
      D2h     1 byte  SUSTAIN RATE
      D3h     1 byte  RELEASE RATE
      D4h     1 byte  LOOP START         (how many times to be looped)
      D5h     1 byte  EXPRESSION
      D6h     1 byte  PRINT VARIABLE     (unknown)
      E0h     2 byte  MODULATION DELAY
      E1h     2 byte  TEMPO
      E3h     2 byte  SWEEP PITCH
      FCh     -       LOOP END           (for LOOP START)
      FDh     -       RETURN from CALL command
      FFh     -       EOT: End Of Track

DS Sound Files - SSAR (Sound Sequence Archive)

It is a collection of SSEQ sequences (mainly for relative short sound effects) (longer sequences like music are usually stored in separate SSEQ files instead of in SSAR archives).
SSAR Header

      000h 4     ID "SSAR"                                  ;\
      004h 2     Byte Order    (FEFFh)                      ;
      006h 2     Version       (0100h)                      ; Main header
      008h 4     Total Filesize                             ;
      00Ch 2     Header Size (usually 10h)                  ;
      00Eh 2     Number of Blocks (usually 1 = DATA)        ;/
      010h 4     ID "DATA"                                  ;\
      014h 4     Total Filesize, minus 10h                  ;
      018h 4     Offset to data (from SSAR+0) (20h+N*0Ch)   ; Sub header
      01Ch 4     Number of records                          ;
      020h N*0Ch Records (12 bytes each)                    ;/
      ..   ..    data... unknown content? alike SSEQ?       ;-

SSAR Records

      000h 4   nOffset    ;relative offset of the archived SEQ file,
                               absolute offset = nOffset + SSAR::nDataOffset
      004h 2   bnk        ;bank
      006h 1   vol        ;volume
      007h 1   cpr        ;channel pressure
      008h 1   ppr        ;polyphonic pressure
      009h 1   ply        ;play
      00Ah 2   reserved (0)

SSAR Data (addressed via relative offset in above 0Ch-byte record)

      data... unknown content? alike SSEQ?

NB. Archived SSEQ files are not stored in sequence (order). So Rec[0].nOffset may point to 0x100 but Rec[1].nOffset points to 0x40.
NB. Archived SSEQ files cannot be readily extracted from SSAR file because data in one SSEQ may 'call' data in other SSEQ.

DS Sound Files - SBNK (Sound Bank)

This seems to assign ADSR patterns to each note of each SWAV instrument...?
"A bank is linked to up to 4 SWAR files which contain the samples. It defines the instruments which a SSEQ sequence can use. You may imagine SSEQ + SBNK + SWAR are similar to module music created by trackers." uh?
SBNK Header

      000h 4   ID "SBNK"                                    ;\
      004h 2   Byte Order    (FEFFh)                        ;
      006h 2   Version       (0100h)                        ; Main header
      008h 4   Total Filesize                               ;
      00Ch 2   Header Size (usually 10h)                    ;
      00Eh 2   Number of Blocks (usually 1 = DATA)          ;/
      010h 4   ID "DATA"                                    ;\
      014h 4   Total Filesize, minus 10h                    ;
      018h 20h Reserved (0) (for use at runtime)            ; Sub header
      038h 4   Number of Instruments (SWAV's)               ;
      03Ch N*4 Instrument Records (1+2+1 bytes per instr.)  ;/
      ...  ..  Instrument Data (depending of above records) ;-

Instrument Record

      000h 1   fRecord     ;can be either 0, 1..4, 16 or 17
      001h 2   nOffset     ;absolute offset of the data in file  ;uh, misaligned?
      003h 1   Reserved (0)

fRecord = 0, it is empty (unknown purpose, dummy? or maybe disable ADSR?)
nOffset will also = 0.
fRecord < 16, the record is a note/wave definition
"I have seen values 1, 2 and 3. But it seems the value does not affect the wave/note definition that follows. Instrument record size is 10 bytes."

      00h 10    SWAV, SWAR, Note, Attack, Decay, Sustain, Release, Pan

fRecord = 16, the record is a range of note/wave definitions

      00h      1   Lower note (0..127)          ;eg. 10 ;\notes 10..20
      01h      1   Upper note (0..127)          ;eg. 20 ;/
      02h+N*12 2   Unknown (usually 0001h)
      04h+N*12 10  SWAV, SWAR, Note, Attack, Decay, Sustain, Release, Pan

fRecord = 17, the record is a regional wave/note definition

      00h      1   End of 1st region (0..127)   ;eg. 25  = notes 0..25
      01h      1   End of 2nd region (0..127)   ;eg. 35  = notes 26..35
      02h      1   End of 3rd region (0..127)   ;eg. 45  = notes 36..45
      03h      1   End of 4th region (0..127)   ;eg. 55  = notes 46..55
      04h      1   End of 5th region (0..127)   ;eg. 65  = notes 56..65
      05h      1   End of 6th region (0..127)   ;eg. 127 = notes 66..last
      06h      1   End of 7th region (0..127)   ;eg. 0   = none
      07h      1   End of 8th region (0..127)   ;eg. 0   = none
      08h+N*12 2   Unknown (usually 0001h)
      08h+N*12 10  SWAV, SWAR, Note, Attack, Decay, Sustain, Release, Pan

REMARKS: Unknown bytes before wave/defnition definition = 5, not 1 in stage_04_bank.sbnk, stage_04.sdat, Rom No.1156, uh?
SWAV, SWAR, Note, Attack, Decay, Sustain, Release, Pan

      00h 2  SWAV Number   the swav used
      02h 2  SWAR Mumber   the swar used (see Info Block --> "BANK Info Entry")
      04h 1  Note Number   (0..127)
      05h 1  Attack Rate   (0..127, 127=fast)
      06h 1  Decay Rate    (0..127, 127=fast)
      07h 1  Sustain Level (0..127, 127=stay at max, no decay)
      08h 1  Release Rate  (0..127, 127=fast)
      09h 1  Pan           (0..127, 64=middle) (uh, what=left, what=right?)

Articulation Data

                 .                   <-- max level (127)
                / \
               /   \
              /     '---------.      <-- sustain level (0..127)
             /                 \
            /                   \
      -----'---------------------'-- <-- min level (0)
          Attack Decay Sustain Release

      "The SEQ Player treats 0 as the 100% amplitude value and -92544 (723*128)
      as the 0% amplitude value. The starting ampltitude is 0% (-92544)." uh?

      "During the attack phase, in each cycle, the SSEQ Player calculates the new
      amplitude value: amplitude value = attack rate * amplitude value / 255. The
      attack phase stops when amplitude reaches 0." THAT IS... NON-LINEAR attack?

      "During the decay phase, in each cycle, the SSEQ Player calculates the new
      amplitude value: amplitude value = amplitude value - decay rate.
      Note the starting amplitude value is 0. The decay phase stops when
      amplitude reaches sustain level." THAT IS... LINEAR decay/release?

DS Sound Files - SWAR (Sound Wave Archive)

It is a collection of mono wave (SWAV) samples only (which can be in either PCM8, PCM16 or ADPCM compression).
SWAR Header

      000h 4     ID "SWAR"                                  ;\
      004h 2     Byte Order    (FEFFh)                      ;
      006h 2     Version       (0100h)                      ; Main header
      008h 4     Total Filesize (including SWAV's)          ;
      00Ch 2     Header Size (usually 10h)                  ;
      00Eh 2     Number of Blocks (usually 1 = DATA)        ;/
      010h 4     ID "DATA"                                  ;\
      014h 4     Total Filesize, minus 10h                  ;
      018h 20h   Reserved (0) (for use at runtime)          ; Sub header
      038h 4     Number of SWAV sample blocks               ;
      03Ch N*4   Offsets to Sample blocks (from SWAR+0)     ;/
      ..   ..    Sample blocks... starting with Type (0=PCM8, 1=PCM16, 2=IMA-ADPCM)

When extracting single sample block, one can convert them to SWAV files (by inserting an 18h-byte SWAV header).
The sample blocks are usually (always?) stored at increasing offsets (so one can determine the size by computing the distance to next offset; or to filesize for last entry) (alternately, the size can be computed by looking at the Sound Length entry of sample block).

DS Sound Files - SWAV (Sound Wave Data)

SWAV Header (present only in standalone SWAV files) (not in SWAR archives)

      000h 4     ID "SWAV"                                  ;\
      004h 2     Byte Order    (FEFFh)                      ;
      006h 2     Version       (0100h)                      ; Main header
      008h 4     Total Filesize                             ;
      00Ch 2     Header Size (usually 10h)                  ;
      00Eh 2     Number of Blocks (usually 1 = DATA)        ;/
      010h 4     ID "DATA"                                  ;\Sub header
      014h 4     Total Filesize, minus 10h                  ;/
      018h ..    Sample block (see below)

Note: System Flaw has a lot of SWAV files (instead of using SWAR archives).
Sample Block Format (present in SWAV files and SWAR archives)

      000h 1    WaveType (0=PCM8, 1=PCM16, 2=IMA-ADPCM)
      001h 1    Loop flag = TRUE|FALSE   ;uh?
      002h 2    Sampling Rate
      004h 2    Time (ARM7_CLOCK / nSampleRate)
                    [ARM7_CLOCK: 33.513982MHz/2 = 1.6756991 E +7]
      006h 2    Loop Offset, in 4-byte units
      008h 4    Sound Length, in 4-byte units (exluding ADPCM header, if any)
      00Ch ...  Data... (samples) (with 32bit header in case of ADPCM)

DS Sound Files - STRM (Sound Wave Stream)

It is an individual mono/stereo wave file (PCM8, PCM16 or ADPCM) (eg. used in Ultimate Spiderman rom:\sound\sound_stream.sdat).
STRM Header

      000h 4     ID "STRM"                                          ;\
      004h 2     Byte Order    (FEFFh)                              ;
      006h 2     Version       (0100h)                              ; Main header
      008h 4     Total Filesize                                     ;
      00Ch 2     Header Size (usually 10h)                          ;
      00Eh 2     Number of Blocks (usually 2 = HEAD+DATA)           ;/
      010h 4     ID "HEAD"                                          ;\
      014h 4     Size of HEAD structure (uh, this is... 50h?)       ;
      018h 1     Type       (0=PCM8, 1=PCM16, 2=IMA-ADPCM)          ; Sub header
      019h 1     Loop flag  (?=TRUE|FALSE)  ;uh?                    ;
      01Ah 1     Channels   (?=What)        ;mono/stereo?           ;
      01Bh 1     Unknown    (always 0)                              ;
      01Ch 2     Sampling Rate (perhaps resampled from original)    ;
      01Eh 2     Time (1.0 / rate * ARM7_CLOCK / 32)                ;
                   [ARM7_CLOCK: 33.513982MHz/2 = 1.6756991e7]       ;
      020h 4     Loop Offset (samples)                              ;
      024h 4     Number of Samples                                  ;
      028h 4     Wave Data Offset (always 68h)                      ;
      02Ch 4     Number of Blocks       (per what?)                 ;
      030h 4     Block Length           (per Channel)               ;
      034h 4     Samples Per Block      (per Channel)               ;
      038h 4     Last Block Length      (per Channel)               ;
      03Ch 4     Samples Per Last Block (per Channel)               ;
      040h 20h   Reserved (always 0)                                ;/
      060h 4     ID "DATA"                                          ;\Data header
      064h 4     Data Size (8+N ?)                                  ;/
      068h N     Wave Data blocks...                                ;-Sample data

Mono blocks are ordered: Block1, Block2, Block3, etc.
Stereo blocks are ordered: LeftBlock1, RightBlock1, LeftBlock2, etc.

DS System and Built-in Peripherals

DS DMA Transfers
DS Timers
DS Interrupts
DS Maths
DS Inter Process Communication (IPC)
DS Keypad
DS Absent Link Port
DS Real-Time Clock (RTC)
DS Serial Peripheral Interface Bus (SPI)
DS Touch Screen Controller (TSC)
DS Power Management Device
DS Power Control
DS Backwards-compatible GBA-Mode
DS Debug Registers (Emulator/Devkits)

DS DMA Transfers

The DS includes four DMA channels for each CPU (ie. eight channels in total), which are working more or less the same as on GBA:
GBA DMA Transfers
All NDS9 and NDS7 DMA Registers are R/W. The gamepak bit (Bit 27) has been removed (on the NDS9 the bit is used to expand the mode setting to 3bits).
NDS9 DMA
Word count of all channels is expanded to 21bits (max 1..1FFFFFh units, or 0=200000h units), and SAD/DAD registers for all channels support ranges of 0..0FFFFFFEh. The transfer modes (DMACNT Bit27-29) are:

      0  Start Immediately
      1  Start at V-Blank
      2  Start at H-Blank (paused during V-Blank)
      3  Synchronize to start of display
      4  Main memory display
      5  DS Cartridge Slot
      6  GBA Cartridge Slot
      7  Geometry Command FIFO

NDS7 DMA
Word Count, SAD, and DAD are R/W, aside from that they do have the same restrictions as on GBA (max 4000h or 10000h units, some addresses limited to 0..07FFFFFEh). DMACNT Bit27 is unused on NDS7. The transfer modes (DMACNT Bit28-29) are:

      0  Start Immediately
      1  Start at V-Blank
      2  DS Cartridge Slot
      3  DMA0/DMA2: Wireless interrupt, DMA1/DMA3: GBA Cartridge Slot

40000E0h - NDS9 only - DMA0FILL - DMA 0 Filldata (R/W)
40000E4h - NDS9 only - DMA1FILL - DMA 1 Filldata (R/W)
40000E8h - NDS9 only - DMA2FILL - DMA 2 Filldata (R/W)
40000ECh - NDS9 only - DMA3FILL - DMA 3 Filldata (R/W)

      Bit0-31 Filldata

The DMA Filldata registers contain 16 bytes of general purpose WRAM, intended to be used as fixed source addresses for DMA memfill operations.
This is useful because DMA cannot read from TCM, and reading from Main RAM would require to recurse cache & write buffer.
The DMA Filldata is used with Src=Fixed and SAD=40000Exh (which isn't optimal because it's doing repeated reads from SAD, and, for that reason, a memfill via STMIA opcodes can be faster than DMA; the DSi's new NDMA channels are providing a faster fill method with Src=Fill and SAD=Unused).
NDS7 Sound DMA
The NDS additionally includes 16 Sound DMA channels, plus 2 Sound Capture DMA channels (see Sound chapter). The priority of these channels is unknown.
NDS9 Cache, Writebuffer, DTCM, and ITCM
Cache and tightly coupled memory are connected directly to the NDS9 CPU, without using the system bus. So that, DMA cannot access DTCM/ITCM, and access to cached memory regions must be handled with care: Drain the writebuffer before DMA-reads, and invalidate the cache after DMA-writes. See,
ARM CP15 System Control Coprocessor
The CPU can be kept running during DMA, provided that it is accessing only TCM (or cached memory), otherwise the CPU is halted until DMA finishes.
Respectively, interrupts executed during DMA will usually halt the CPU (unless the IRQ handler uses only TCM and cache; the IRQ vector at FFFF00xxh must be cached, or relocated to ITCM at 000000xxh, and the IRQ handler may not access IE, IF, or other I/O ports).
NDS Sequential Main Memory DMA
Main RAM has different access time for sequential and non-sequential access. Normally DMA uses sequential access (except for the first word), however, if the source and destination addresses are both in Main RAM, then all accesses become non-sequential. In that case it would be faster to use two DMA transfers, one from Main RAM to a scratch buffer in WRAM, and one from WRAM to Main RAM.

DS Timers

Same as GBA, except F = 33.513982 MHz (for both NDS9 and NDS7).
GBA Timers
Both NDS9 and NDS7 have four Timers each, eight Timers in total.
The NDS sound controller is having its own frequency generators (unlike GBA, which needed to use Timers to drive channel A/B sounds).

DS Interrupts

4000208h - NDS9/NDS7 - IME - Interrupt Master Enable (R/W)

      0     Disable all interrupts  (0=Disable All, 1=See IE register)
      1-31  Not used

4000210h - NDS9/NDS7 - IE - 32bit - Interrupt Enable (R/W)
4000214h - NDS9/NDS7 - IF - 32bit - Interrupt Request Flags (R/W)
Bits in the IE register are 0=Disable, 1=Enable.
Reading IF returns 0=No request, 1=Interrupt Request.
Writing IF acts as 0=No change, 1=Acknowledge (clears that bit).

      0     LCD V-Blank
      1     LCD H-Blank
      2     LCD V-Counter Match
      3     Timer 0 Overflow
      4     Timer 1 Overflow
      5     Timer 2 Overflow
      6     Timer 3 Overflow
      7     NDS7 only: SIO/RCNT/RTC (Real Time Clock)
      8     DMA 0
      9     DMA 1
      10    DMA 2
      11    DMA 3
      12    Keypad
      13    GBA-Slot (external IRQ source) / DSi: None such
      14    Not used                       / DSi9: NDS-Slot Card change?
      15    Not used                       / DSi: dito for 2nd NDS-Slot?
      16    IPC Sync
      17    IPC Send FIFO Empty
      18    IPC Recv FIFO Not Empty
      19    NDS-Slot Game Card Data Transfer Completion
      20    NDS-Slot Game Card IREQ_MC
      21    NDS9 only: Geometry Command FIFO
      22    NDS7 only: Screens unfolding
      23    NDS7 only: SPI bus
      24    NDS7 only: Wifi    / DSi9: XpertTeak DSP
      25    Not used           / DSi9: Camera
      26    Not used           / DSi9: Undoc, IF.26 set on FFh-filling 40021Axh
      27    Not used           / DSi:  Maybe IREQ_MC for 2nd gamecard?
      28    Not used           / DSi: NewDMA0
      29    Not used           / DSi: NewDMA1
      30    Not used           / DSi: NewDMA2
      31    Not used           / DSi: NewDMA3
      ?     DSi7: any further new IRQs on ARM7 side... in bit13-15,21,25-26?

Raw TCM-only IRQs can be processed even during DMA ?
Trying to set all IE bits gives FFFFFFFFh (DSi7) or FFFFFF7Fh (DSi9).
4000218h - DSi7 - IE2 - DSi7 Extra Interrupt Enable Bits
400021Ch - DSi7 - IF2 - DSi7 Extra Interrupt Flags

      0     DSi7: GPIO18[0]   ;\
      1     DSi7: GPIO18[1]   ; maybe 1.8V signals?
      2     DSi7: GPIO18[2]   ;/
      3     DSi7: Unused (0)
      4     DSi7: GPIO33[0] unknown (related to "GPIO330" testpoint on mainboard?)
      5     DSi7: GPIO33[1] Headphone connect (HP#SP) (static state)
      6     DSi7: GPIO33[2] Powerbutton interrupt (short pulse upon key-down)
      7     DSi7: GPIO33[3] sound enable output (ie. not a useful irq-input)
      8     DSi7: SD/MMC Controller   ;-Onboard eMMC and External SD Slot
      9     DSi7: SD Slot Data1 pin   ;-For SDIO hardware in External SD Slot
      10    DSi7: SDIO Controller     ;\Atheros Wifi Unit
      11    DSi7: SDIO Data1 pin      ;/
      12    DSi7: AES interrupt
      13    DSi7: I2C interrupt
      14    DSi7: Microphone Extended interrupt
      15-31 DSi7: Unused (0)

Trying to set all IE2 bits gives 00007FF7h (DSi7) or 00000000h (DSi9).
DTCM+3FFCh - NDS9 - IRQ Handler (hardcoded DTCM address)
380FFFCh - NDS7 - IRQ Handler (hardcoded RAM address)

      Bit 0-31  Pointer to IRQ Handler

NDS7 Handler must use ARM code, NDS9 Handler can be ARM/THUMB (Bit0=Thumb).
DTCM+3FF8h - NDS9 - IRQ Check Bits (hardcoded DTCM address)
380FFF8h - NDS7 - IRQ Check Bits (hardcoded RAM address)

      Bit 0-31  IRQ Flags (same format as IE/IF registers)

When processing & acknowleding interrupts via IF register, the user interrupt handler should also set the corresponding bits of the IRQ Check value (required for BIOS IntrWait and VBlankIntrWait SWI functions).
380FFC0h - DSi7 only - Extra IRQ Check Bits for IE2/IF2 (hardcoded RAM addr)
Same as the above 380FFF8h value, but for new IE2/IF2 registers, intended for use with IntrWait and VBlankIntrWait functions. However, that functions are BUGGED on DSi and won't actually work in practice (they do support only the new 380FFC0h bits, but do accidently ignore the old 380FFF8h bits).
--- Below for other (non-IRQ) exceptions ---
27FFD9Ch - RAM - NDS9 Debug Stacktop / Debug Vector (0=None)
380FFDCh - RAM - NDS7 Debug Stacktop / Debug Vector (0=None)
These addresses contain a 32bit pointer to the Debug Handler, and, memory below of the addresses is used as Debug Stack. The debug handler is called on undefined instruction exceptions, on data/prefetch aborts (caused by the protection unit), on FIQ (possibly caused by hardware debuggers). It is also called by accidental software-jumps to the reset vector, and by unused SWI numbers within range 0..1Fh.

DS Maths

4000280h - NDS9 - DIVCNT - Division Control (R/W)

      0-1   Division Mode    (0-2=See below) (3=Reserved; same as Mode 1)
      2-13  Not used
      14    Division by zero (0=Okay, 1=Division by zero error; 64bit Denom=0)
      15    Busy             (0=Ready, 1=Busy) (Execution time see below)
      16-31 Not used

Division Modes and Busy Execution Times

      Mode  Numer / Denom = Result, Remainder ; Cycles
      0     32bit / 32bit = 32bit , 32bit     ; 18 clks
      1     64bit / 32bit = 64bit , 32bit     ; 34 clks
      2     64bit / 64bit = 64bit , 64bit     ; 34 clks

Division is started when writing to any of the DIVCNT/NUMER/DENOM registers.
4000290h - NDS9 - DIV_NUMER - 64bit Division Numerator (R/W)
4000298h - NDS9 - DIV_DENOM - 64bit Division Denominator (R/W)
Signed 64bit values (or signed 32bit values in 32bit modes, the upper 32bits are then unused, with one exception: the DIV0 flag in DIVCNT is set only if the full 64bit DIV_DENOM value is zero, even in 32bit mode).
40002A0h - NDS9 - DIV_RESULT - 64bit Division Quotient (=Numer/Denom) (R)
40002A8h - NDS9 - DIVREM_RESULT - 64bit Remainder (=Numer MOD Denom) (R)
Signed 64bit values (in 32bit modes, the values are sign-expanded to 64bit).
Division Overflows
Overflows occur on "DIV0" and "-MAX/-1" (eg. -80000000h/-1 in 32bit mode):

      DIV0     -->  REMAIN=NUMER, RESULT=+/-1 (with sign opposite of NUMER)
      -MAX/-1  -->  RESULT=-MAX               (instead +MAX)

On overflows in 32bit/32bit=32bit mode: the upper 32bit of the sign-expanded 32bit result are inverted. This feature produces a correct 64bit (+MAX) result in case of the incorrect 32bit (-MAX) result. The feature also applies on DIV0 errors (which makes the sign-expanded 64bit result even more messed-up than the normal 32bit result).
The DIV0 flag in DIVCNT.14 indicates DENOM=0 errors (it does not indicate "-MAX/-1" errors). The DENOM=0 check relies on the full 64bit value (so, in 32bit mode, the flag works only if the unused upper 32bit of DENOM are zero).
40002B0h - NDS9 - SQRTCNT - Square Root Control (R/W)

      0     Mode (0=32bit input, 1=64bit input)
      1-14  Not used
      15    Busy (0=Ready, 1=Busy) (Execution time is 13 clks, in either Mode)
      16-31 Not used

Calculation is started when writing to any of the SQRTCNT/PARAM registers.
40002B4h - NDS9 - SQRT_RESULT - 32bit - Square Root Result (R)
40002B8h - NDS9 - SQRT_PARAM - 64bit - Square Root Parameter Input (R/W)
Unsigned 64bit parameter, and unsigned 32bit result.
IRQ Notes
Push all DIV/SQRT values (parameters and control registers) when using DIV/SQRT registers on interrupt level, and, after restoring them, be sure to wait until the busy flag goes off, before leaving the IRQ handler.
BIOS Notes
The NDS9 and NDS7 BIOSes additionally contain software based division and square root functions, which are NOT using above hardware registers (even the NDS9 functions are raw software).
Timing Notes
The Div/Sqrt timings are counted in 33.51MHz units. Although the calculations are quite fast, mind that reading/writing the result/parameter registers takes up additional clock cycles (especially due to the PENALTY cycle glitch for non-sequential accesses; parts of that problem can be eventually bypassed by using sequential STMIA/LDMIA opcodes) (nethertheless, in some cases, software may be actually faster than the hardware registers; eg. for small 8bit numbers; that of course NOT by using the BIOS software functions which are endless inefficient).

DS Inter Process Communication (IPC)

Allows to exchange status information between ARM7 and ARM9 CPUs.
The register can be accessed simultaneously by both CPUs (without violating access permissions, and without generating waitstates at either side).
4000180h - NDS9/NDS7 - IPCSYNC - IPC Synchronize Register (R/W)

      Bit   Dir  Expl.
      0-3   R    Data input from IPCSYNC Bit8-11 of remote CPU (00h..0Fh)
      4-7   -    Not used
      8-11  R/W  Data output to IPCSYNC Bit0-3 of remote CPU   (00h..0Fh)
      12    -    Not used
      13    W    Send IRQ to remote CPU      (0=None, 1=Send IRQ)
      14    R/W  Enable IRQ from remote CPU  (0=Disable, 1=Enable)
      15-31 -    Not used

4000184h - NDS9/NDS7 - IPCFIFOCNT - IPC Fifo Control Register (R/W)

      Bit   Dir  Expl.
      0     R    Send Fifo Empty Status      (0=Not Empty, 1=Empty)
      1     R    Send Fifo Full Status       (0=Not Full, 1=Full)
      2     R/W  Send Fifo Empty IRQ         (0=Disable, 1=Enable)
      3     W    Send Fifo Clear             (0=Nothing, 1=Flush Send Fifo)
      4-7   -    Not used
      8     R    Receive Fifo Empty          (0=Not Empty, 1=Empty)
      9     R    Receive Fifo Full           (0=Not Full, 1=Full)
      10    R/W  Receive Fifo Not Empty IRQ  (0=Disable, 1=Enable)
      11-13 -    Not used
      14    R/W  Error, Read Empty/Send Full (0=No Error, 1=Error/Acknowledge)
      15    R/W  Enable Send/Receive Fifo    (0=Disable, 1=Enable)
      16-31 -    Not used

4000188h - NDS9/NDS7 - IPCFIFOSEND - IPC Send Fifo (W)

      Bit0-31  Send Fifo Data (max 16 words; 64bytes)

4100000h - NDS9/NDS7 - IPCFIFORECV - IPC Receive Fifo (R)

      Bit0-31  Receive Fifo Data (max 16 words; 64bytes)

IPCFIFO Notes
When IPCFIFOCNT.15 is disabled: Writes to IPCFIFOSEND are ignored (no data is stored in the FIFO, the error bit doesn't get set though), and reads from IPCFIFORECV return the oldest FIFO word (as usually) (but without removing the word from the FIFO).
When the Receive FIFO is empty: Reading from IPCFIFORECV returns the most recently received word (if any), or ZERO (if there was no data, or if the FIFO was cleared via IPCFIFOCNT.3), and, in either case the error bit gets set.
The Fifo-IRQs are edge triggered, IF.17 gets set when the condition "(IPCFIFOCNT.2 AND IPCFIFOCNT.0)" changes from 0-to-1, and IF.18 gets set when "(IPCFIFOCNT.10 AND NOT IPCFIFOCNT.8)" changes from 0-to-1. The IRQ flags can be acknowledged even while that conditions are true.

DS Keypad

For the GBA-buttons: Same as GBA, both ARM7 and ARM9 have keyboard input registers, and each its own keypad IRQ control register.
GBA Keypad Input
For Touchscreen (and Microphone) inputs, see
DS Touch Screen Controller (TSC)
4000136h - NDS7 - EXTKEYIN - Key X/Y Input (R)

      0      Button X     (0=Pressed, 1=Released)
      1      Button Y     (0=Pressed, 1=Released)
      3      DEBUG button (0=Pressed, 1=Released/None such)
      6      Pen down     (0=Pressed, 1=Released/Disabled) (always 0 in DSi mode)
      7      Hinge/folded (0=Open, 1=Closed)
      2,4,5  Unknown / set
      8..15  Unknown / zero

The Hinge stuff is a magnetic sensor somewhere underneath of the Start/Select buttons (NDS) or between A/B/X/Y buttons (DSi), it will be triggered by the magnet field from the right speaker when the console is closed. The hinge generates an interrupt request (there seems to be no way to disable this, unlike as for all other IRQ sources), however, the interrupt execution can be disabled in IE register (as for other IRQ sources).
The Pen Down is the /PENIRQ signal from the Touch Screen Controller (TSC), if it is enabled in the TSC control register, then it will notify the program when the screen pressed, the program should then read data from the TSC (if there's no /PENIRQ then doing unneccassary TSC reads would just waste CPU power). However, the user may release the screen before the program performs the TSC read, so treat the screen as not pressed if you get invalid TSC values (even if /PENIRQ was LOW).
Not sure if the TSC /PENIRQ is actually triggering an IRQ in the NDS?
The Debug Button should be connected to R03 and GND (on original NDS, R03 is the large soldering point between the SL1 jumper and the VR1 potentiometer) (there is no R03 signal visible on the NDS-Lite board).
Interrupts are reportedly not supported for X,Y buttons.

DS Absent Link Port

The DS doesn't have a Serial Link Port Socket, however, internally, the NDS7 contains the complete set of Serial I/O Ports, as contained in the GBA:
GBA Communication Ports
In GBA mode, the ports are working as on real GBA (as when no cable is connected). In NDS mode, the ports are even containing some additional bits:
NDS7 SIO Bits (according to an early I/O map from Nintendo)

      NDS7 4000128h SIOCNT   Bit15 "CKUP"  New Bit in NORMAL/MULTI/UART mode (R/W)
      NDS7 4000128h SIOCNT   Bit14 "N/A"   Removed IRQ Bit in UART mode (?)
      NDS7 400012Ah SIOCNT_H Bit14 "TFEMP" New Bit (R/W)
      NDS7 400012Ah SIOCNT_H Bit15 "RFFUL" New Bit (always zero?)
      NDS7 400012Ch SIOSEL   Bit0  "SEL"   New Bit (always zero?)
      NDS7 4000140h JOYCNT   Bit7  "MOD"   New Bit (R/W)

The "CKUP" bit duplicates the internal clock transfer rate (selected in SIOCNT.1) (tested in normal mode) (probably works also in multi/uart mode?).
NDS7 DS-Lite 4001080h (W) (?)
DS-Lite Firmware writes FFFFh to this address (prior to accessing SIOCNT), so it's probably SIO or debugging related (might be as well a bug or so). Reading from the port always returns 0000h on both DS and DS-Lite.
NDS9 SIO Bits (according to an early I/O map from Nintendo)

      NDS9 4000120h SIODATA32 Bit0-31 Data            (always zero?)
      NDS9 4000128h SIOCNT    Bit2    "TRECV" New Bit (always zero?)
      NDS9 4000128h SIOCNT    Bit3    "TSEND" New Bit (always zero?)
      NDS9 400012Ch SIOSEL    Bit0    "SEL"   New Bit (always zero?)

Not sure if these ports really exist in the release-version, or if it's been prototype stuff?
RCNT
RCNT (4000134h) should be set to 80xxh (general purpose mode) before accessing EXTKEYIN (4000136h) or RTC (4000138h). No idea why (except when using RTC/SI-interrupt).
DS Serial Port
The SI line is labeled "INT" on the NDS mainboard, it is connected to Pin 1 of the RTC chip (ie. the /INT interrupt pin).
I have no idea where to find SO, SC, and SD. I've written a test proggy that pulsed all four RCNT bits - but all I could find was the SI signal. However, the BIOS contains some code that uses SIO normal mode transfers (for the debug version), so at least SI, SO, SC should exist...?
MAYBE that three signals are somehow replaced by EXTKEYIN bit0,1,3?

DS Real-Time Clock (RTC)

NDS
Seiko Instruments Inc. S-35180 (compatible with S-35190A)
Miniature 8pin RTC with 3-wire serial bus
DSi
Seiko S-35199A01 (12pin BGA, with some extra functions like FOUT and Alarm Date)
4000138h - NDS7 - Real Time Clock Register

      Bit  Expl.
      0    Data I/O   (0=Low, 1=High)
      1    Clock Out  (0=Low, 1=High)
      2    Select Out (0=Low, 1=High/Select)
      4    Data  Direction  (0=Read, 1=Write)
      5    Clock Direction  (should be 1=Write)
      6    Select Direction (should be 1=Write)
      3,8-11   Unused I/O Lines
      7,12-15  Direction for Bit3,8-11 (usually 0)
      16-31    Not used

Serial Transfer Flowchart
Chipselect and Command/Parameter Sequence:

      Init CS=LOW and /SCK=HIGH, and wait at least 1us
      Switch CS=HIGH, and wait at least 1us
      Send the Command byte (see bit-transfer below)
      Send/receive Parameter byte(s) associated with the command (see below)
      Switch CS to LOW

Bit transfer (repeat 8 times per cmd/param byte) (bits transferred LSB first):

      Output /SCK=LOW and SIO=databit (when writing), then wait at least 5us
      Output /SCK=HIGH, wait at least 5us, then read SIO=databit (when reading)
      In either direction, data is output on (or immediately after) falling edge.

Ideally, <both> commands and parameters should be transmitted LSB-first (unlike the original Seiko document, which recommends LSB-first for data, and MSB-first for commands) (actually, later Seiko datasheets are going so far to recommend MSB-first for everything, eg. to use bit-reversed Data=C8h for Year=13h).
Command Register

      Command Register
        Fwd  Rev
        0    7   Fixed Code (must be 0)
        1    6   Fixed Code (must be 1)
        2    5   Fixed Code (must be 1)
        3    4   Fixed Code (must be 0, or, DSi only: 1=Extended Command)
        4-6  3-1 Command
                 Fwd Rev Parameter bytes (read/write access)
                 0   0   1 byte, status register 1
                 4   1   1 byte, status register 2
                 2   2   7 bytes, date & time (year,month,day,day_of_week,hh,mm,ss)
                 6   3   3 bytes, time (hh,mm,ss)
                 1*  4*  1 byte, int1, frequency duty setting
                 1*  4*  3 bytes, int1, alarm time 1 (day_of_week, hour, minute)
                 5   5   3 bytes, int2, alarm time 2 (day_of_week, hour, minute)
                 3   6   1 byte, clock adjustment register
                 7   7   1 byte, free register
                 Extended command (when above "fourth bit" was set, DSi only)
                 Fwd Rev Parameter bytes (read/write access)
                 0   0   3 byte, up counter (msw,mid,lsw) (read only)
                 4   1   1 byte, FOUT register setting 1
                 2   2   1 byte, FOUT register setting 2
                 6   3   reserved
                 1   4   3 bytes, alarm date 1 (year,month,day)
                 5   5   3 bytes, alarm date 2 (year,month,day)
                 3   6   reserved
                 7   7   reserved
        7    0   Parameter Read/Write Access (0=Write, 1=Read)

* INT1: Type and number of parameters depend on INT1 setting in stat reg2.
The "Fwd" bit numbers and command values for LSB-first command transfers (ie. both commands and parameters use the same bit-order).
The "Rev" numbers/values are for MSB-first command transfers (ie. commands using opposite bit-order than parameters, as being suggested by Seiko).
Control and Status Registers

      Status Register 1
        0   W   Reset                (0=Normal, 1=Reset)
        1   R/W 12/24 hour mode      (0=12 hour, 1=24 hour)
        2-3 R/W General purpose bits
        4   R   Interrupt 1 Flag (1=Yes)                      ;auto-cleared on read
        5   R   Interrupt 2 Flag (1=Yes)                      ;auto-cleared on read
        6   R   Power Low Flag (0=Normal, 1=Power is/was low) ;auto-cleared on read
        7   R   Power Off Flag (0=Normal, 1=Power was off)    ;auto-cleared on read
        Power off indicates that the battery was removed or fully discharged,
        all registers are reset to 00h (or 01h), and must be re-initialized.
      Status Register 2
        0-3 R/W INT1 Mode/Enable
                0000b Disable
                0x01b Selected Frequency steady interrupt
                0x10b Per-minute edge interrupt
                0011b Per-minute steady interrupt 1 (duty 30.0 seconds)
                0100b Alarm 1 interrupt
                0111b Per-minute steady interrupt 2 (duty 0.0079 seconds)
                1xxxb 32kHz output
        4-5 R/W General purpose bits
        6   R/W INT2 Enable
                0b    Disable
                1b    Alarm 2 interrupt
        7   R/W Test Mode (0=Normal, 1=Test, don't use) (cleared on Reset)
      Clock Adjustment Register (to compensate oscillator inaccuracy)
        0-7 R/W Adjustment (00h=Normal, no adjustment)
      Free Register
        0-7 R/W General purpose bits

Date Registers

      Year Register
        0-7 R/W Year     (BCD 00h..99h = 2000..2099)
      Month Register
        0-4 R/W Month    (BCD 01h..12h = January..December)
        5-7 -   Not used (always zero)
      Day Register
        0-5 R/W Day      (BCD 01h..28h,29h,30h,31h, range depending on month/year)
        6-7 -   Not used (always zero)
      Day of Week Register (septenary counter)
        0-2 R/W Day of Week (00h..06h, custom assignment, usually 0=Monday?)
        3-7 -   Not used (always zero)

Time Registers

      Hour Register
        0-5 R/W Hour     (BCD 00h..23h in 24h mode, or 00h..11h in 12h mode)
        6   *   AM/PM    (0=AM before noon, 1=PM after noon)
                * 24h mode: AM/PM flag is read only (PM=1 if hour = 12h..23h)
                * 12h mode: AM/PM flag is read/write-able
                * 12h mode: Observe that 12 o'clock is defined as 00h (not 12h)
        7   -   Not used (always zero)
      Minute Register
        0-6 R/W Minute   (BCD 00h..59h)
        7   -   Not used (always zero)
      Second Register
        0-6 R/W Minute   (BCD 00h..59h)
        7   -   Not used (always zero)

Alarm 1 and Alarm 2 Registers

      Alarm1 and Alarm2 Day of Week Registers (INT1 and INT2 each)
        0-2 R/W Day of Week (00h..06h)
        3-6 -   Not used (always zero)
        7   R/W Compare Enable (0=Alarm every day, 1=Alarm only at specified day)
      Alarm1 and Alarm2 Hour Registers (INT1 and INT2 each)
        0-5 R/W Hour     (BCD 00h..23h in 24h mode, or 00h..11h in 12h mode)
        6   R/W AM/PM    (0=AM, 1=PM) (must be correct even in 24h mode?)
        7   R/W Compare Enable (0=Alarm every hour, 1=Alarm only at specified hour)
      Alarm1 and Alarm2 Minute Registers (INT1 and INT2 each)
        0-6 R/W Minute   (BCD 00h..59h)
        7   R/W Compare Enable (0=Alarm every min, 1=Alarm only at specified min)
      Selected Frequency Steady Interrupt Register (INT1 only) (when Stat2/Bit2=0)
        0   R/W Enable 1Hz Frequency  (0=Disable, 1=Enable)
        1   R/W Enable 2Hz Frequency  (0=Disable, 1=Enable)
        2   R/W Enable 4Hz Frequency  (0=Disable, 1=Enable)
        3   R/W Enable 8Hz Frequency  (0=Disable, 1=Enable)
        4   R/W Enable 16Hz Frequency (0=Disable, 1=Enable)
                The signals are ANDed when two or more frequencies are enabled,
                ie. the /INT signal gets LOW when either of the signals is LOW.
        5-7 R/W General purpose bits

Note: There is only one register shared as "Selected Frequency Steady Interrupt" (accessed as single byte parameter when Stat2/Bit2=0) and as "Alarm1 Minute" (accessed as 3rd byte of 3-byte parameter when Stat2/Bit2=1), changing either value will also change the other value.
Up Counter (DSi only)

      Up Counter Msw
        0-7 R   Up Counter bit16-23 (non-BCD, 00h..FFh)
      Up Counter Mid
        0-7 R   Up Counter bit8-15  (non-BCD, 00h..FFh)
      Up Counter Lsw
        0-7 R   Up Counter bit0-7   (non-BCD, 00h..FFh)

The 24bit Up Counter is incremented when seconds=00h (that is, once per minute; unless the Time is getting getting changed by write commands, which may cause some stuttering). The Up Counter starts at 000000h upon power-up, and, if the battery lasts that long: wraps from FFFFFFh to 000000h after about 30 years.
Alarm 1 and Alarm 2 Date Registers (DSi only)

      Alarm 1 and Alarm 2 Year Register
        0-7 R/W Year     (BCD 00h..99h = 2000..2099)
      Alarm 1 and Alarm 2 Month Register
        0-4 R/W Month    (BCD 01h..12h = January..December)
        5   -   Not used (always zero)
        6   R/W Year Compare Enable (0=Ignore, 1=Enable)
        7   R/W Month Compare Enable (0=Ignore, 1=Enable)
      Alarm 1 and Alarm 2 Day Register
        0-5 R/W Day      (BCD 01h..28h,29h,30h,31h, range depending on month/year)
        6   -   Not used (always zero)
        7   R/W Day Compare Enable (0=Ignore, 1=Enable)

XXX unspecified if above Alarm Date stuff is really R/W (or write only)
FOUT Register (DSi only)

      FOUT Register Setting 1
        0-7 R/W  Enable bits (bit0=256Hz, bit1=512Hz, ..., bit7=32768Hz)
      FOUT Register Setting 2
        0-7 R/W  Enable bits (bit0=1Hz,   bit1=2Hz, ...,   bit7=128Hz)
      The above sixteen FOUT signals are ANDed when two or more frequencies are
      enabled, ie. the FOUT signal gets LOW when either of the signals is LOW.

Note: The FOUT pin goes to the DSi's wifi daughterboard (FOUT is configured by firmware (needed if it was changed, or when the battery was removed), FOUT is required for exchanging Atheros WMI commands/events).
Interrupt
There's only one /INT signal, shared for both INT1 and INT2.
In the NDS, it is connected to the SI-input of the SIO unit (and so, also shared with SIO interrupts). To enable the interrupt, RCNT should be set to 8144h (Bit14-15=General Purpose mode, Bit8=SI Interrupt Enable, Bit6,2=SI Output/High).
The Output/High settings seems to be used as pullup (giving faster reactions on low-to-high transitions) (nethertheless, in most cases it seems to be also working okay as Input, ie. with RCNT=8100h).
The RCNT interrupt is generated on high-to-low transitions on the SI line (but only if the IRQ is enabled in RCNT.8, and only if RCNT is set to general purpose mode) (note: changing RCNT.8 from off-to-on does NOT generate IRQs, even when SI is LOW).
Pin-Outs

      1 /INT      8 VDD
      2 XOUT      7 SIO
      3 XIN       6 /SCK
      4 GND       5 CS

DS Serial Peripheral Interface Bus (SPI)

Serial Peripheral Interface Bus
SPI Bus is a 4-wire (Data In, Data Out, Clock, and Chipselect) serial bus.
The NDS supports the following SPI devices (each with its own chipselect).
DS Firmware Serial Flash Memory
DS Touch Screen Controller (TSC)
DS Power Management Device
40001C0h - NDS7 - SPICNT - SPI Bus Control/Status Register

      0-1   Baudrate (0=4MHz/Firmware, 1=2MHz/Touchscr, 2=1MHz/Powerman., 3=512KHz)
      2     DSi: Baudrate MSB   (4=8MHz, 5..7=None/0Hz) (when SCFG_EXT7.bit9=1)
      2     NDS: Not used       (Zero)
      3-6   Not used            (Zero)
      7     Busy Flag           (0=Ready, 1=Busy) (presumably Read-only)
      8-9   Device Select       (0=Powerman., 1=Firmware, 2=Touchscr, 3=Reserved)
      10    Transfer Size       (0=8bit/Normal, 1=16bit/Bugged)
      11    Chipselect Hold     (0=Deselect after transfer, 1=Keep selected)
      12-13 Not used            (Zero)
      14    Interrupt Request   (0=Disable, 1=Enable)
      15    SPI Bus Enable      (0=Disable, 1=Enable)

The "Hold" flag should be cleared BEFORE transferring the LAST data unit, the chipselect will be then automatically cleared after the transfer, the program should issue a WaitByLoop(3) manually AFTER the LAST transfer.
40001C2h - NDS7 - SPIDATA - SPI Bus Data/Strobe Register (R/W)
The SPI transfer is started on writing to this register, so one must <write> a dummy value (should be zero) even when intending to <read> from SPI bus.

      0-7   Data
      8-15  Not used (always zero, even in bugged-16bit mode)

During transfer, the Busy flag in SPICNT is set, and the written SPIDATA value is transferred to the device (via output line), simultaneously data is received (via input line). Upon transfer completion, the Busy flag goes off (with optional IRQ), and the received value can be then read from SPIDATA, if desired.
Notes/Glitches
SPICNT Bits 12,13 appear to be unused (always zero), although the BIOS (attempts to) set Bit13=1, and Bit12=Bit11 when accessing the firmware.
The SPIDATA register is restricted to 8bit, so that only each 2nd byte will appear in SPIDATA when attempting to use the bugged-16bit mode.
Cartridge Backup Auxiliar SPI Bus
The NDS Cartridge Slot uses a separate SPI bus (with other I/O Ports), see
DS Cartridge Backup

DS Touch Screen Controller (TSC)

Texas Instruments TSC2046 (NDS)
Asahi Kasei Microsystems AK4148AVT (NDS-Lite)
The Touch Screen Controller (for lower LCD screen) is accessed via SPI bus,
DS Serial Peripheral Interface Bus (SPI)
Control Byte (transferred MSB first)

      0-1  Power Down Mode Select
      2    Reference Select (0=Differential, 1=Single-Ended)
      3    Conversion Mode  (0=12bit, max CLK=2MHz, 1=8bit, max CLK=3MHz)
      4-6  Channel Select   (0-7, see below)
      7    Start Bit (Must be set to access Control Byte)

Channel

      0 Temperature 0 (requires calibration, step 2.1mV per 1'C accuracy)
      1 Touchscreen Y-Position  (somewhat 0B0h..F20h, or FFFh=released)
      2 Battery Voltage         (not used, connected to GND in NDS, always 000h)
      3 Touchscreen Z1-Position (diagonal position for pressure measurement)
      4 Touchscreen Z2-Position (diagonal position for pressure measurement)
      5 Touchscreen X-Position  (somewhat 100h..ED0h, or 000h=released)
      6 AUX Input               (connected to Microphone in the NDS)
      7 Temperature 1 (difference to Temp 0, without calibration, 2'C accuracy)

All channels can be accessed in Single-Ended mode.
In differential mode, only channel 1,3,4,5 (X,Z1,Z2,Y) can be accessed.
On AK4148AVT, channel 6 (AUX) is split into two separate channels, IN1 and IN2, separated by Bit2 (Reference Select). IN1 is selected when Bit2=1, IN2 is selected when Bit2=0 (despite of the Bit2 settings, both IN1 and IN2 are using single ended more). On the NDS-Lite, IN1 connects to the mircrophone (as on original NDS), and the new IN2 input is simply wired to VDD3.3 (which is equal to the external VREF voltage, so IN2 is always FFFh).
Power Down Mode

      Mode /PENIRQ   VREF  ADC   Recommended use
      0    Enabled   Auto  Auto  Differential Mode (Touchscreen, Penirq)
      1    Disabled  Off   On    Single-Ended Mode (Temperature, Microphone)
      2    Enabled   On    Off   Don't use
      3    Disabled  On    On    Don't use

Allows to enable/disable the /PENIRQ output, the internal reference voltage (VREF), and the Analogue-Digital Converter.
For AK4148AVT, Power Down modes are slightly different (among others, /PENIRQ is enabled in Mode 0..2).
Reference Voltage (VREF)
VREF is used as reference voltage in single ended mode, at 12bit resolution one ADC step equals to VREF/4096. The TSC generates an internal VREF of 2.5V (+/-0.05V), however, the NDS uses as external VREF of 3.33V (sinks to 3.31V at low battery charge), the external VREF is always enabled, no matter if internal VREF is on or off. Power Down Mode 1 disables the internal VREF, which may reduce power consumption in single ended mode. After conversion, Power Down Mode 0 should be restored to re-enable the Penirq signal.
Sending the first Command after Chip-Select
Switch chipselect low, then output the command byte (MSB first).
Reply Data
The following reply data is received (via Input line) after the Command byte has been transferred: One dummy bit (zero), followed by the 8bit or 12bit conversion result (MSB first), followed by endless padding (zero).
Note: The returned ADC value may become unreliable if there are longer delays between sending the command, and receiving the reply byte(s).
Sending further Commands during/after receiving Reply Data
In general, the Output line should be LOW during the reply period, however, once when Data bit6 has been received (or anytime later), a new Command can be invoked (started by sending the HIGH-startbit, ie. Command bit7), simultaneously, the remaining reply-data bits (bit5..0) can be received.
In other words, the new command can be output after receiving 3 bits in 8bit mode (the dummy bit, and data bits 7..6), or after receiving 7 bits in 12bit mode (the dummy bit, and data bits 11..6).
In practice, the NDS SPI register always transfers 8 bits at once, so that one would usually receive 8 bits (rather than above 3 or 7 bits), before outputting a new command.
Touchscreen Position
Read the X and Y positions in 12bit differential mode, then convert the touchscreen values (adc) to screen/pixel positions (scr), as such:

      scr.x = (adc.x-adc.x1) * (scr.x2-scr.x1) / (adc.x2-adc.x1) + (scr.x1-1)
      scr.y = (adc.y-adc.y1) * (scr.y2-scr.y1) / (adc.y2-adc.y1) + (scr.y1-1)

The X1,Y1 and X2,Y2 calibration points are found in Firmware User Settings,
DS Firmware User Settings
scr.x1,y1,x2,y2 are originated at 1,1 (converted to 0,0 by above formula).
Touchscreen Pressure (not supported on DSi)
To calculate the pressure resistance, in respect to X/Y/Z positions and X/Y plate resistances, either of below formulas can be used,

      Rtouch = (Rx_plate*Xpos*(Z2pos/Z1pos-1))/4096
      Rtouch = (Rx_plate*Xpos*(4096/Z1pos-1)-Ry_plate*(1-Ypos))/4096

The second formula requires less CPU load (as it doesn't require to measure Z2), the downside is that one must know both X and Y plate resistance (or at least their ratio). The first formula doesn't require that ratio, and so Rx_plate can be set to any value, setting it to 4096 results in

      touchval = Xpos*(Z2pos/Z1pos-1)

Of course, in that case, touchval is just a number, not a resistance in Ohms.
Touchscreen Notes
It may be impossible to press locations close to the screen borders.
When pressing two or more locations the TSC values will be somewhere in the middle of these locations.
The TSC values may be garbage if the screen becomes newly pressed or released, to avoid invalid inputs: read TSC values at least two times, and ignore BOTH positions if ONE position was invalid.
Microphone / AUX Channel
Observe that the microphone amplifier is switched off after power up, see:
DS Power Management Device
DS Power Control
Temperature Calculation (not supported on DSi)
TP0 decreases by circa 2.1mV per degree Kelvin. The voltage difference between TP1 minus TP0 increases by circa 0.39mV (1/2573 V) per degree Kelvin. At VREF=3.33V, one 12bit ADC step equals to circa 0.8mV (VREF/4096).
Temperature can be calculated at best resolution when using the current TP0 value, and two calibration values (an ADC value, and the corresponding temperature in degrees kelvin):

      K = (CAL.TP0-ADC.TP0) * 0.4 + CAL.KELVIN

Alternately, temperature can be calculated at rather bad resolution, but without calibration, by using the difference between TP1 and TP0:

      K = (ADC.TP1-ADC.TP0) * 8568 / 4096

To convert Kelvin to other formats,

      Celsius:     C = (K-273.15)
      Fahrenheit:  F = (K-273.15)*9/5+32
      Reaumur:     R = (K-273.15)*4/5
      Rankine:     X = (K)*9/5

The Temperature Range for the TSC 2046 chip is -40'C..+85'C (for AK4181AVT only -20'C..+70'C). According to Nintendo, the DS should not be exposed to "extreme" heat or cold, the optimal battery charging temperature is specified as +10'C..+40'C.
The original firmware does not support temperature calibration, calibration is supported by nocash firmware (if present). See Extended Settings,
DS Firmware Extended Settings
Pin-Outs

             ________
      VCC  1|o       |16 DCLK
      X+   2|        |15 /CS
      Y+   3|  TSC   |14 DIN
      X-   4|  2046  |13 BUSY
      Y-   5|        |12 DOUT
      GND  6|        |11 /PENIRQ
      VBAT 7|        |10 IOVDD
      AUX  8|________|9  VREF

For AK4181AVT, same pins as above, except that IOVDD replaced by the new IN2 input, the pin is wired to VDD3.3 (so IN2 is always equal to VREF, which is wired to VDD3.3, too) (and AUX is renamed to IN1, and is kept used for MIC input).
DSi Touchscreen Controller (in NDS mode)
DSi in NDS mode does support only X, Y, and MIC (all other channels do return FFFh in 12bit mode, and FFh in 8bit mode, ie. no pressure, no temperature, and no GNDed battery sensor). On DSi, MIC does return data in both single-ended and differential mode (unlike as on real NDS).
DSi Touchscreen Controller (in DSi mode)
The DSi touchscreen controller supports a NDS backwards compatibility mode. But, in DSi mode, it is working entirely different (it's still accessed via SPI bus, but with some new MODE/INDEX values).
DSi Touchscreen/Sound Controller
The NDS Touchscreen controller did additionally allow to read Temperature and Touchscreen Pressure - unknown if the DSi is also supporting such stuff (via whatever DSi-specific registers).
The touchscreen hardware can be switched to NDS compatibility mode (for older games), but unknown how to do that.

DS Power Control

The DS contains several Power Managment functions, some accessed via I/O ports (described below), and some accessed via SPI bus:
DS Power Management Device
4000304h - NDS9 - POWCNT1 - Graphics Power Control Register (R/W)

      0     Enable Flag for both LCDs (0=Disable) (Prohibited, see notes)
      1     2D Graphics Engine A      (0=Disable) (Ports 008h-05Fh, Pal 5000000h)
      2     3D Rendering Engine       (0=Disable) (Ports 320h-3FFh)
      3     3D Geometry Engine        (0=Disable) (Ports 400h-6FFh)
      4-8   Not used
      9     2D Graphics Engine B      (0=Disable) (Ports 1008h-105Fh, Pal 5000400h)
      10-14 Not used
      15    Display Swap (0=Send Display A to Lower Screen, 1=To Upper Screen)
      16-31 Not used

Use SwapBuffers command once after enabling Rendering/Geometry Engine.
Improper use of Bit0 may damage the hardware?
When disabled, corresponding Ports become Read-only, corresponding (palette-) memory becomes read-only-zero-filled.
4000304h - NDS7 - POWCNT2 - Sound/Wifi Power Control Register (R/W)

      Bit   Expl.
      0     Sound Speakers (0=Disable, 1=Enable) (Initial setting = 1)
      1     Wifi           (0=Disable, 1=Enable) (Initial setting = 0)
      2-31  Not used

Note: Bit0 disables the internal Speaker only, headphones are not disabled.
Bit1 disables Port 4000206h, and Ports 4800000h-480FFFFh.
4000206h - NDS7 - WIFIWAITCNT - Wifi Waitstate Control

      Bit   Expl.
      0-2   Wifi WS0 Control (0-7) (Ports 4800000h-4807FFFh)
      3-5   Wifi WS1 Control (0-7) (Ports 4808000h-480FFFFh)
      4-15  Not used (zero)

This register is initialized by firmware on power-up, don't change.
Note: WIFIWAITCNT can be accessed only when enabled in POWCNT2.
4000301h - NDS7 - HALTCNT - Low Power Mode Control (R/W)
In Halt mode, the CPU is paused as long as (IE AND IF)=0.
In Sleep mode, most of the hardware including sound and video are paused, this very-low-power mode could be used much like a screensaver.

      Bit   Expl.
      0-5   Not used (zero)
      6-7   Power Down Mode  (0=No function, 1=Enter GBA Mode, 2=Halt, 3=Sleep)

The HALTCNT register should not be accessed directly. Instead, the BIOS Halt, Sleep, CustomHalt, IntrWait, or VBlankIntrWait SWI functions should be used.
BIOS Halt Functions
ARM CP15 System Control Coprocessor
The NDS9 does not have a HALTCNT register, instead, the Halt function uses the co-processor opcode "mcr p15,0,r0,c7,c0,4" - this opcode locks up if interrupts are disabled via IME=0 (unlike NDS7 HALTCNT method which doesn't check IME).
4000300h - NDS7/NDS9 - POSTFLG - BYTE - Post Boot Flag (R/W)
The NDS7 and NDS9 post boot flags are usually set upon BIOS/Firmware boot completion, once when set the reset vector is redirected to the debug handler of Nintendo's hardware debugger. That allows the NDS7 debugger to capture accidental jumps to address 0, that appears to be a common problem with HLL-programmers, asm-coders know that (and why) they should not jump to 0.

      Bit   Expl.
      0     Post Boot Flag (0=Boot in progress, 1=Boot completed)
      1     NDS7: Not used (always zero), NDS9: Bit1 is read-writeable
      2-7   Not used (always zero)

There are some write-restrictions: The NDS7 register can be written to only from code executed in BIOS (done by NDS boot ROM, or by DSi firmware, whereas the DSi firmware is using the CpuSet SWI function to issue the POSTFLG write from within ROM). Bit0 of both NDS7 and NDS9 registers cannot be cleared (except by Reset) once when it is set. DSi games seem to run regardless of POSTFLG, whilst NDS games somewhat refuse to run when POSTFLG=0.
Memory Power Down Functions
DS Main Memory Control
DS Firmware Serial Flash Memory

DS Power Management Device

Power Management Device - Mitsumi 3152A (NDS) / Mitsumi 3205B (NDS-LITE)
The Power Management Device is accessed via SPI bus,
DS Serial Peripheral Interface Bus (SPI)
To access the device, write the Index Register, then read or write the data register, and release the chipselect line when finished.

      Index Register
      Bit0-6 Register Select          (0..3) (0..4 for DS-Lite) (0..7Fh for DSi)
      Bit7   Register Direction       (0=Write, 1=Read)
      Register 0 - Powermanagement Control (R/W)
      Bit0   Sound Amplifier Enable   (0=Disable, 1=Enable)
             (Old-DS:  Disabled: Sound is very silent, but still audible)
             (DS-Lite: Disabled: Sound is NOT audible)
             (DSi in NDS Mode: R/W, but effect is unknown yet)
             (DSi in DSi Mode: Not used, Bit0 is always 1)
      Bit1   Sound Amplifier Mute     (0=Normal, 1=Mute) (Old-DS Only, not DS-Lite)
             (Old-DS:  Muted: Sound is NOT audible, that works only if Bit0=1)
             (DS-Lite: Not used, Bit1 is always zero)
             (DSi in NDS Mode: R/W, but effect is unknown yet)
             (DSi in DSi Mode: R/W, but effect is unknown yet)
      Bit2   Lower Backlight          (0=Disable, 1=Enable)
      Bit3   Upper Backlight          (0=Disable, 1=Enable)
      Bit4   Power LED Blink Enable   (0=Always ON, 1=Blinking OFF/ON)
      Bit5   Power LED Blink Speed    (0=Slow, 1=Fast) (only if Blink enabled)
             (DSi: Power LED Blinking isn't supported, neither in NDS nor DSi mode)
      Bit6   DS System Power          (0=Normal, 1=Shut Down)
      Bit7   Not used                 (always 0)
      Register 1 - Battery Status (R)
      Bit0   Battery Power LED Status (0=Power Good/Green, 1=Power Low/Red)
             (DSi: Usually 0, not tested if it changes upon Power=Low)
      Bit1-7 Not used
      Register 2 - Microphone Amplifier Control (R/W)
      Bit0   Amplifier                (0=Disable, 1=Enable)
      Bit1-7 Not used                 (always 0)
      (DSi in NDS Mode: looks same as NDS, ie. only bit0 is R/W)
      (DSi in DSi Mode: Not used, always FFh)
      Register 3 - Microphone Amplifier Gain Control (R/W)
      Bit0-1 Gain                     (0..3=Gain 20, 40, 80, 160)
      Bit2-7 Not used                 (always 0)
      (DSi in NDS Mode: looks same as NDS, ie. only bit0-1 are R/W)
      (DSi in DSi Mode: Not used, always FFh)
      Register 4 - DS-Lite and DSi Only - Backlight Levels/Power Source (R/W)
      Bit0-1 Backlight Brightness (0..3=Low,Med,High,Max)   (R/W)
             (when bit2+3 are both set, then reading bit0-1 always returns 3)
      Bit2   Force Max Brightness when Bit3=1 (0=No, 1=Yes) (R/W)
      Bit3   External Power Present           (0=No, 1=Yes) (Read-Only)
      Bit4-7 Unknown (Always 4) (Read-Only)
      (DSi in NDS Mode: looks same as in DSi mode)
      (DSi in DSi Mode: Bit0-1 are R/W, but ignored, bit2-3 are always 0)
      Register 10h - DSi Only - Backlight Mirrors & Reset (R/W)
      Bit0   Reset (0=No, 1=Reboot DSi) (same/similar as BPTWL reset feature?)
      Bit1   Unknown (R/W) (note: whatever it is, it isn't warmboot flag)
      Bit2-3 Mirror of Register 0, bit2-3 (backlight enable bits) (R/W)
      Bit4-7 Not used (always 0)
      (This register works in NDS mode and DSi mode, though it's mainly intended
      for NDS mode, eg. DS Download Play uses the Reset bit to return to DSi menu)
      (note: writing bit2 seems to affect BOTH bit1 and bit2 in register 0)

On Old-DS, registers 4..7Fh are mirrors of 0..3. On DS-Lite, registers 5,6,7 are mirrors of 4, register 8..7Fh are mirrors of 0-7.
On DSi (in DS mode), index 0,1,2,3,4,10h are used (reads as 0Fh,00h,00h,01h,41h,0Fh - regardless of backlight level, and power source), index 5..0Fh and 11h..7Fh return 00h (ie. unlike DS and DS-Lite, there are no mirrors; aside from the mirrored bits in register 10h).
Backlight Dimming / Backlight caused Shut-Down(s)
The above bits are essentially used to switch Backlights on or off. However, there a number of strange effects. Backlight dimming is possible by pulse width modulation, ie. by using a timer interrupt to issue pulse widths of N% ON, and 100-N% OFF. Too long pulses are certainly resulting in flickering. Too short pulses are ignored, the backlights will remain OFF, even if the ON and OFF pulses are having the same length. Much too short pulses cause the power supply to shut-down; after changing the backlight state, further changes must not occur within the next (circa) 2500 clock cycles. The mainboard can be operated without screens & backlights connected, however, if so, the power supply will shut-down as soon as backlights are enabled.
Pulse width modulated dimming does also work on the DS-Lite, allowing to use smoother fade in/out effects as when using the five "hardware" levels (Off,Low,Med,High,Max).

DS Main Memory Control

Main Memory
The DS Main Memory is 2Mx16bit (4MByte), 1.8V Pseudo SRAM (PSRAM); all Dynamic RAM refresh is handled internally, the chip doesn't require any external refresh signals, and alltogether behaves like Static RAM. Non-sequential access time is 70ns, sequential (burst) access time is 12ns.
Main Memory Control
The memory chips contain built-in Control functions, which can be accessed via Port 27FFFFEh and/or by EXMEMCNT Bit 14. Nintendo is using at least two different types of memory chips in DS consoles, Fujitsu 82DBS02163C-70L, and ST M69AB048BL70ZA8, both appear to have different control mechanisms, other chips (with 8MB size) are used in the semi-professional DS hardware debuggers, and further chips may be used in future, so using the memory control functions may lead into compatibitly problems.
Power Consumption / Power Control
Power Consumption during operation (read/write access) is somewhat 30mA, in standby mode (no read/write access) consumption is reduced to 100uA.
Furthermore, a number of power-down modes are supported: In "Deep" Power Down mode the refresh is fully disabled, consumption is 10uA (and all data will be lost), in "Partial" Power Down modes only fragment of memory is refreshed, for smallest fragments, consumption goes to down to circa 50uA. The chip cannot be accessed while it is in Deep or Partial Power Down mode.
Fujitsu 82DBS02163C-70L
The Configuration Register (CR) can be written to by the following sequence:

      LDRH R0,[27FFFFEh]      ;read one value
      STRH R0,[27FFFFEh]      ;write should be same value as above
      STRH R0,[27FFFFEh]      ;write should be same value as above
      STRH R0,[27FFFFEh]      ;write any value
      STRH R0,[27FFFFEh]      ;write any value
      LDRH R0,[2400000h+CR*2] ;read, address-bits are defining new CR value

Do not access any other Main Memory addresses during above sequence (ie. disable interrupts, and do not execute the sequence by code located in Main Memory). The CR value is write-only. The CR bits are:

      Bit    Expl.
      0-6    Reserved         (Must be 7Fh)
      7      Write Control
               0=WE Single Clock Pulse Control without Write Suspend Function
               1=WE Level Control with Write Suspend Function)
              Burst Read/Single Write is not supported at WE Single Clock Mode.
      8      Reserved         (Must be 1)
      9      Valid Clock Edge (0=Falling Edge, 1=Rising Edge)
      10     Single Write     (0=Burst Read/Burst Write, 1=Burst Read/Single Write)
      11     Burst Sequence   (0=Reserved, 1=Sequential)
      12-14  Read Latency     (1=3 clocks, 2=4 clocks, 3=5 clocks, other=Reserved)
      15     Mode
               0=Synchronous:  Burst Read, Burst Write
               1=Asynchronous: Page Read, Normal Write
              In Mode 1 (Async), only the Partial Size bits are used,
              all other bits, CR bits 0..18, must be "1".
      16-18  Burst Length     (2=8 Words, 3=16Words, 7=Continous, other=Reserved)
      19-20  Partial Size     (0=1MB, 1=512KB, 2=Reserved, 3=Deep/0 bytes)

The Power Down mode is entered by setting CE2=LOW, this can be probably done by setting EXMEMCNT Bit14 to zero.
ST Microelectronics M69AB048BL70ZA8
The chip name decodes as PSRAM (M96), Asynchronous (A), 1.8V Burst (B), 2Mx16 (048), Two Chip Enables (B), Low Leakage (L), 70ns (70), Package (ZA), -30..+85'C (8).
There are three data sheets for different PSRAM chips available at www.st.com (unfortunately none for M69AB048BL70ZA8), each using different memory control mechanisms.
NDS9 BIOS
The NDS9 BIOS contains the following Main Memory initialization code, that method doesn't match up with any ST (nor Fujitsu) data sheets that I've seen. At its best, it looks like a strange (and presumably non-functional) mix-up of different ST control methods.

      STRH 2000h,[4000204h]    ;EXMEMCNT, enable RAM, async mode
      LDRH R0,[27FFFFEh]
      STRH R0,[27FFFFEh]
      STRH R0,[27FFFFEh]
      STRH FFDFh,[27FFFFEh]
      STRH E732h,[27FFFFEh]
      LDRH R0,[27E57FEh]
      STRH 6000h,[4000204h]    ;EXMEMCNT, enable RAM, normal mode

DS Backwards-compatible GBA-Mode

When booting a 32pin GBA cartridge, the NDS is automatically switched into GBA mode, in that mode all NDS related features are disabled, and the console behaves (almost) like a GBA.
GBA Features that are NOT supported on NDS in GBA Mode.
Unlike real GBA, the NDS does not support 8bit DMG/CGB cartridges.
The undocumented Internal Memory Control register (Port 800h) isn't supported, so the NDS doesn't allow to use 'overclocked' RAM.
The NDS doesn't have a link-port, so GBA games can be played only in single player mode, link-port accessories cannot be used, and the NDS cannot run GBA code via multiboot.
GBA Features that are slightly different on NDS in GBA Mode.
The CPU, Timers, and Sound Frequencies are probably clocked at 16.76MHz; 33.51MHz/2; a bit slower than the original GBA's 16.78MHz clock?
In the BIOS, a single byte in a formerly 00h-filled area has been changed from 00h to 01h, resulting in SWI 0Dh returning a different BIOS checksum.
The GBA picture can be shown on upper or lower screen (selectable in boot-menu), the backlight for the selected screen is always on, resulting in different colors & much better visibility than original GBA. Unlike GBA-SP, the NDS doesn't have a backlight-button.
Screen Border in GBA mode
The GBA screen is centered in the middle of the NDS screen. The surrounding pixels are defined by 32K-color bitmap data in VRAM Block A and B. Each frame, the GBA picture is captured into one block, and is displayed in the next frame (while capturing new data to the other block).
To get a flicker-free border, both blocks should be initialized to contain the same image before entering GBA mode (usually both are zero-filled, resulting in a plain black border).
Note: When using two different borders, the flickering will be irregular - so there appears to be a frame inserted or skipped once every some seconds in GBA mode?!
Switching from NDS Mode to GBA Mode

      --- NDS9: ---
      ZEROFILL VRAM A,B     ;init black screen border (or other color/image)
      POWCNT=8003h          ;enable 2D engine A on upper screen (0003h=lower)
      EXMEMCNT=...          ;set Async Main Memory mode (clear bit14)
      IME=0                 ;disable interrupts
      SWI 06h               ;halt with interrupts disabled (lockdown)
      --- NDS7: ---
      POWERMAN.REG0=09h     ;enable sound amplifier & upper backlight (05h=lower)
      IME=0                 ;disable interrupts
      wait for VCOUNT=200   ;wait until VBlank
      SWI 1Fh with R2=40h   ;enter GBA mode, by CustomHalt(40h)

After that, the GBA BIOS will be booted, the GBA Intro will be displayed, and the GBA cartridge (if any) will be started.

DS Debug Registers (Emulator/Devkits)

No$gba Emulator Pseudo I/O Ports (no$gba) (GBA,NDS9,NDS7)

      4FFFA00h..A0Fh R Emulation ID (16 bytes, eg. "no$gba v2.7", padded with 20h)
      4FFFA10h       W String Out (raw)
      4FFFA14h       W String Out (with %param's)
      4FFFA18h       W String Out (with %param's, plus linefeed)
      4FFFA1Ch       W Char Out (nocash)
      4FFFA20h..A27h R Clock Cycles (64bit)
      4FFFA28h..A3Fh - N/A

Note: Above ports can be disabled via the "Debug I/O" option in no$gba setup.
Ensata Emulator Pseudo I/O Ports (NDS9)

      4000640h (32bit) ;aka CLIPMTX_RESULT (mis-used to invoke detection)
      4000006h (16bit) ;aka VCOUNT (mis-used to get detection result)
      4FFF010h (32bit) ;use to initialize/unlock/reset something
      4FFF000h (8bit)  ;debug message character output (used when Ensata detected)

The Ensata detection works by mis-using CLIPMTX_RESULT and VCOUNT registers:

      [4000640h]=2468ACE0h      ;CLIPMTX_RESULT (on real hardware it's read-only)
      if ([4000006h] AND 1FFh)=10Eh ;VCOUNT (on real hardware it's 000h..106h)
        [4FFF010h]=13579BDFh        ;\initialize/reset something
        [4FFF010h]=FDB97531h        ;/
        Ensata=true
      else
        Ensata=false
      endif

Once when a commercial game has detected Ensata, it stops communicating with the ARM7, and instead it does seem to want to communicate with the Ensata executable (which has little to do with real NDS hardware). Ie. aside from "unlocking" port 4FFF000h, it does also "lock" access to the ARM7 hardware (like sound, touchscreen, RTC, etc).
ISD (Intelligent Systems Debugger or so) I/O Ports
The ISD ports seem to be real (non-emulated) debugging ports, mapped to the GBA Slot region at 8000000h-9FFFFFFh, and used to output text messages, and possible also other debugging stuff.
There are appear to be two variants: nitroemu and cgbemu (the latter appears to be dating back to old 8bit CGB hardware; which was apparently still used for the NDS two hardware generations later).
NDS Devkit
In Nintendo's devkit, debug messages are handled in file "os_printf.c", this file detects the available hardware/software based debug I/O ports, and redirects the [OS_PutString] vector to the corresponding string_out function (eg. to OS_PutStringAris for writing a 00h-terminated string to port 4FFF000h). With some minimal efforts, this could be redirected to the corresponding no$gba debug I/O ports.

DS Cartridges, Encryption, Firmware

Cartridges
DS Cartridge Header
DS Cartridge Secure Area
DS Cartridge Icon/Title
DS Cartridge Protocol
DS Cartridge Backup
DS Cartridge I/O Ports
DS Cartridge NitroROM and NitroARC File Systems
DS Cartridge PassMe/PassThrough
DS Cartridge GBA Slot
Cartridge File Formats
DS File Formats
Add-Ons
DS Cart Rumble Pak
DS Cart Slider with Rumble
DS Cart Expansion RAM
DS Cart Unknown Extras
Special Cartridges
DS Cart Cheat Action Replay DS
DS Cart Cheat Codebreaker DS
DS Cart DLDI Driver
Encryption
DS Encryption by Gamecode/Idcode (KEY1)
DS Encryption by Random Seed (KEY2)
Firmware / Wifi Flash
DS Firmware Serial Flash Memory
DS Firmware Header
DS Firmware Wifi Calibration Data
DS Firmware Wifi Internet Access Points
DS Firmware User Settings
DS Firmware Extended Settings

DS Cartridge Header

Header Overview (loaded from ROM Addr 0 to Main RAM 27FFE00h on Power-up)

      Address Bytes Expl.
      000h    12    Game Title  (Uppercase ASCII, padded with 00h)
      00Ch    4     Gamecode    (Uppercase ASCII, NTR-<code>)        (0=homebrew)
      010h    2     Makercode   (Uppercase ASCII, eg. "01"=Nintendo) (0=homebrew)
      012h    1     Unitcode    (00h=NDS, 02h=NDS+DSi, 03h=DSi) (bit1=DSi)
      013h    1     Encryption Seed Select (00..07h, usually 00h)
      014h    1     Devicecapacity         (Chipsize = 128KB SHL nn) (eg. 7 = 16MB)
      015h    7     Reserved    (zero filled)
      01Ch    1     Reserved    (zero)                      (except, used on DSi)
      01Dh    1     NDS Region  (00h=Normal, 80h=China, 40h=Korea) (other on DSi)
      01Eh    1     ROM Version (usually 00h)
      01Fh    1     Autostart (Bit2: Skip "Press Button" after Health and Safety)
                    (Also skips bootmenu, even in Manual mode & even Start pressed)
      020h    4     ARM9 rom_offset    (4000h and up, align 1000h)
      024h    4     ARM9 entry_address (2000000h..23BFE00h)
      028h    4     ARM9 ram_address   (2000000h..23BFE00h)
      02Ch    4     ARM9 size          (max 3BFE00h) (3839.5KB)
      030h    4     ARM7 rom_offset    (8000h and up)
      034h    4     ARM7 entry_address (2000000h..23BFE00h, or 37F8000h..3807E00h)
      038h    4     ARM7 ram_address   (2000000h..23BFE00h, or 37F8000h..3807E00h)
      03Ch    4     ARM7 size          (max 3BFE00h, or FE00h) (3839.5KB, 63.5KB)
      040h    4     File Name Table (FNT) offset
      044h    4     File Name Table (FNT) size
      048h    4     File Allocation Table (FAT) offset
      04Ch    4     File Allocation Table (FAT) size
      050h    4     File ARM9 overlay_offset
      054h    4     File ARM9 overlay_size
      058h    4     File ARM7 overlay_offset
      05Ch    4     File ARM7 overlay_size
      060h    4     Port 40001A4h setting for normal commands (usually 00586000h)
      064h    4     Port 40001A4h setting for KEY1 commands   (usually 001808F8h)
      068h    4     Icon/Title offset (0=None) (8000h and up)
      06Ch    2     Secure Area Checksum, CRC-16 of [[020h]..00007FFFh]
      06Eh    2     Secure Area Delay (in 131kHz units) (051Eh=10ms or 0D7Eh=26ms)
      070h    4     ARM9 Auto Load List Hook RAM Address (?) ;\endaddr of auto-load
      074h    4     ARM7 Auto Load List Hook RAM Address (?) ;/functions
      078h    8     Secure Area Disable (by encrypted "NmMdOnly") (usually zero)
      080h    4     Total Used ROM size (remaining/unused bytes usually FFh-padded)
      084h    4     ROM Header Size (4000h)
      088h    28h   Reserved (zero filled; except, [88h..93h] used on DSi)
      0B0h    10h   Reserved (zero filled; or "DoNotZeroFillMem"=unlaunch fastboot)
      0C0h    9Ch   Nintendo Logo (compressed bitmap, same as in GBA Headers)
      15Ch    2     Nintendo Logo Checksum, CRC-16 of [0C0h-15Bh], fixed CF56h
      15Eh    2     Header Checksum, CRC-16 of [000h-15Dh]
      160h    4     Debug rom_offset   (0=none) (8000h and up)       ;only if debug
      164h    4     Debug size         (0=none) (max 3BFE00h)        ;version with
      168h    4     Debug ram_address  (0=none) (2400000h..27BFE00h) ;SIO and 8MB
      16Ch    4     Reserved (zero filled) (transferred, and stored, but not used)
      170h    90h   Reserved (zero filled) (transferred, but not stored in RAM)

DSi Cartridges are using an extended cartridge header,
DSi Cartridge Header
Some of that new/changed DSi header entries are important even in NDS mode:
- On DSi, ARM9/ARM7 areas are restricted to 2.75MB (instead 3.8MB on real NDS)
- New NDS titles must have RSA signatures (and old titles must be in whitelist)
For more info about CRC-16, see description of GetCRC16 BIOS function,
BIOS Misc Functions
For the Logo checksum, the BIOS verifies only [15Ch]=CF56h, it does NOT verify the actual data at [0C0h-15Bh] (nor it's checksum), however, the data is verified by the firmware.
Secure Area Delay
The Secure Area Delay at header[06Eh] is counted in 130.912kHz units (which can be clocked via one of the hardware timers with prescaler=F/256 and reload=(10000h-((X AND 3FFFh)+2)); for some weird reason, in case of Header checksum it's ANDed with 1FFFh instead of 3FFFh). Commonly used values are X=051Eh (10ms), and X=0D7Eh (26ms).
The delay is used for all Blowfish encrypted commands, the actual usage/purpose differs depending on bit31 of the ROM Chip ID:
When ChipID.Bit31=0 (commands are sent ONCE): The delay is issued BEFORE sending the command:

      Delay,Cmd

Older/newer games are using delays of 10ms/26ms (although all known existing cartridges with Bit31=0 would actually work WITHOUT delays).
When ChipID.Bit31=1 (commands are repeated MULTIPLE times): The delay is issued AFTER sending the command for the FIRST time:

      Cmd,Delay,Cmd                                ;for 2x repeat
      Cmd,Delay,Cmd,Cmd,Cmd,Cmd,Cmd,Cmd,Cmd,Cmd    ;for 9x repeat

Known games are using delays of 26ms (although all known existing cartridges (=Cooking Coach) with Bit31=1 would actually work with shorter delays of ca. 7ms (but, better use 8ms for safety)).
NDS Gamecodes
This is the same code as the NTR-UTTD (NDS) or TWL-UTTD (DSi) code which is printed on the package and sticker on (commercial) cartridges (excluding the leading "NTR-" or "TWL-" part).

      U  Unique Code          (usually "A", "B", "C", or special meaning)
      TT Short Title          (eg. "PM" for Pac Man)
      D  Destination/Language (usually "J" or "E" or "P" or specific language)

The first character (U) is usually "A" or "B", in detail:

      A NDS common games
      B NDS common games
      C NDS common games
      D DSi-exclusive games
      H DSiWare (system utilities and browser) (eg. HNGP=browser)
      I NDS and DSi-enhanced games with built-in Infrared port
      K DSiWare (dsiware games and flipnote) (eg. KGUV=flipnote)
      N NDS nintendo channel demo's japan (NTR-NTRJ-JPN)
      T NDS many games
      U NDS utilities, educational games, or uncommon extra hardware?
      V DSi-enhanced games
      Y NDS many games

The second/third characters (TT) are:

      Usually an abbreviation of the game title (eg. "PM" for "Pac Man") (unless
      that gamecode was already used for another game, then TT is just random)

The fourth character (D) indicates Destination/Language:

      A Asian    E English/USA  I Italian   M Swedish  Q Danish   U Australian
      B N/A      F French       J Japanese  N Nor      R Russian  V EUR+AUS
      C Chinese  G N/A          K Korean    O Int      S Spanish  W..Z Europe #3..5
      D German   H Dutch        L USA #2    P Europe   T USA+AUS

DS Cartridge Secure Area

The Secure Area is located in ROM at 4000h..7FFFh, it can contain normal program code and data, however, it can be used only for ARM9 boot code, it cannot be used for ARM7 boot code, icon/title, filesystem, or other data.
Secure Area Size
The Secure Area exists if the ARM9 boot code ROM source address (src) is located within 4000h..7FFFh, if so, it will be loaded (by BIOS via KEY1 encrypted commands) in 4K portions, starting at src, aligned by 1000h, up to address 7FFFh. The secure area size if thus 8000h-src, regardless of the ARM9 boot code size entry in header.
Note: The BIOS silently skips any NDS9 bootcode at src<4000h.
Cartridges with src>=8000h do not have a secure area.
Secure Area ID
The first 8 bytes of the secure area are containing the Secure Area ID, the ID is required (verified by BIOS boot code), the ID value changes during boot process:

      Value                Expl.
      "encryObj"           raw ID before encryption (raw ROM-image)
      (encrypted)          encrypted ID after encryption (encrypted ROM-image)
      "encryObj"           raw ID after decryption (verified by BIOS boot code)
      E7FFDEFFh,E7FFDEFFh  destroyed ID (overwritten by BIOS after verify)

If the decrypted ID does match, then the BIOS overwrites the first 8 bytes by E7FFDEFFh-values (ie. only the ID is destroyed). If the ID doesn't match, then the first 800h bytes (2K) are overwritten by E7FFDEFFh-values.
Secure Area First 2K Encryption/Content
The first 2K of the Secure Area (if it exists) are KEY1 encrypted. In official games, this 2K region contains data like so (in decrypted form):

      000h..007h  Secure Area ID (see above)
      008h..00Dh  Fixed (FFh,DEh,FFh,E7h,FFh,DEh)
      00Eh..00Fh  CRC16 across following 7E0h bytes, ie. [010h..7FFh]
      010h..7FDh  Unknown/random values, mixed with some THUMB SWI calls
      7FEh..7FFh  Fixed (00h,00h)

Of which, only the ID in the first 8 bytes is verified. Neither BIOS nor (current) firmare versions are verifying the data at 008h..7FFh, so the 7F8h bytes may be also used for normal program code/data.
Avoiding Secure Area Encryption
WLAN files are reportedly same format as cartridges, but without Secure Area, so games with Secure Area cannot be booted via WLAN. No$gba can encrypt and decrypt Secure Areas only if the NDS BIOS-images are present. And, Nintendo's devkit doesn't seem to support Secure Area encryption of unreleased games.
So, unencrypted cartridges are more flexible in use. Ways to avoid encryption (which still work on real hardware) are:
1) Set NDS9 ROM offset to 4000h, and leave the first 800h bytes of the Secure Area 00h-filled, which can be (and will be) safely destroyed during loading; due to the missing "encryObj" ID; that method is used by Nintendo's devkit.
2) Set NDS9 ROM offset to 8000h or higher (cartridge has no Secure Area at all).
3) Set NDS9 ROM offset, RAM address, and size to zero, set NDS7 ROM offset to 200h, and point both NDS9 and NDS7 entrypoints to the loaded NDS7 region. That method avoids waste of unused memory at 200h..3FFFh, and it should be compatible with the NDS console, however, it is not comaptible with commercial cartridges - which do silently redirect address below 4000h to "addr=8000h+(addr AND 1FFh)". Still, it should work with inofficial flashcards, which do not do that redirection. No$gba emulates the redirection for regular official cartridges, but it disables redirection for homebrew carts if NDS7 rom offset<8000h, and NDS7 size>0.
[One possible problem: Newer "anti-passme" firmware versions reportedly check that the entrypoint isn't set to 80000C0h, that firmwares might also reject NDS9 entrypoints within the NDS7 bootcode region?]

DS Cartridge Icon/Title

The ROM offset of the Icon/Title is defined in CartHdr[68h]. The size was originally implied by the size of the original Icon/Title structure rounded to 200h-byte sector boundary (ie. A00h bytes for Version 1 or 2), however, later DSi carts are having a size entry at CartHdr[208h] (usually 23C0h).
If it is present (ie. if CartHdr[68h]=nonzero), then Icon/Title are displayed in the bootmenu.

      0000h 2     Version (0001h, 0002h, 0003h, or 0103h)
      0002h 2     CRC16 across entries 0020h..083Fh (all versions)
      0004h 2     CRC16 across entries 0020h..093Fh (Version 0002h and up)
      0006h 2     CRC16 across entries 0020h..0A3Fh (Version 0003h and up)
      0008h 2     CRC16 across entries 1240h..23BFh (Version 0103h and up)
      000Ah 16h   Reserved (zero-filled)
      0020h 200h  Icon Bitmap  (32x32 pix) (4x4 tiles, 4bit depth) (4x8 bytes/tile)
      0220h 20h   Icon Palette (16 colors, 16bit, range 0000h-7FFFh)
                  (Color 0 is transparent, so the 1st palette entry is ignored)
      0240h 100h  Title 0 Japanese  (128 characters, 16bit Unicode)
      0340h 100h  Title 1 English   ("")
      0440h 100h  Title 2 French    ("")
      0540h 100h  Title 3 German    ("")
      0640h 100h  Title 4 Italian   ("")
      0740h 100h  Title 5 Spanish   ("")
      0840h 100h  Title 6 Chinese   ("")                 (Version 0002h and up)
      0940h 100h  Title 7 Korean    ("")                 (Version 0003h and up)
      0A40h 800h  Zerofilled (probably reserved for Title 8..15)

Below for animated DSi icons only (Version 0103h and up):

      1240h 1000h Icon Animation Bitmap 0..7 (200h bytes each, format as above)
      2240h 100h  Icon Animation Palette 0..7 (20h bytes each, format as above)
      2340h 80h   Icon Animation Sequence (16bit tokens)

Unused/padding bytes:

      0840h 1C0h  Unused/padding (FFh-filled) in Version 0001h
      0940h C0h   Unused/padding (FFh-filled) in Version 0002h
      23C0h 40h   Unused/padding (FFh-filled) in Version 0103h

Versions

      0001h = Original
      0002h = With Chinese Title
      0003h = With Chinese+Korean Titles
      0103h = With Chinese+Korean Titles and animated DSi icon

Title Strings
Usually, for non-multilanguage games, the same (english) title is stored in all title entries. The title may consist of ASCII characters 0020h-007Fh, character 000Ah (linefeed), and should be terminated/padded by 0000h.
The whole text should not exceed the dimensions of the DS cart field in the bootmenu (the maximum number of characters differs due to proportional font).
The title is usually split into a primary title, optional sub-title, and manufacturer, each separated by 000Ah character(s). For example: "America", 000Ah, "The Axis of War", 000Ah, "Cynicware", 0000h.
Icon Animation Sequence (DSi)
The sequence is represented by 16bit tokens, in the following format:

      15    Flip Vertically   (0=No, 1=Yes)
      14    Flip Horizontally (0=No, 1=Yes)
      13-11 Palette Index     (0..7)
      10-8  Bitmap Index      (0..7)
      7-0   Frame Duration    (01h..FFh) (in 60Hz units)

Value 0000h indicates the end of the sequence. If the first token is 0000h, then the non-animated default image is shown.
Uh, actually, a non-animated icon uses values 01h,00h,00h,01h, followed by 7Ch zerofilled bytes (ie. 0001h, 0100h, 3Eh x 0000h)?
FAT16:\title\000300tt\4ggggggg\data\banner.sav ;if carthdr[1BFh].bit2=1
Some DSi games are having a separate "banner.sav" file stored in the eMMC filesystem, enabled via carthdr[1BFh].bit2 (allowing to indicate the game progress by overriding the default icon). The banner files are 4000h bytes in size, the animation data is same as above, but without title strings and without non-animated icon.

      0000h 2     Version (0103h)
      0002h 6     Reserved (zero-filled)
      0008h 2     CRC16 across entries 0020h..119Fh (with initial value FFFFh)
      000Ah 16h   Reserved (zero-filled)
      0020h 1000h Icon Animation Bitmap 0..7 (200h bytes each)  ;\same format as
      1020h 100h  Icon Animation Palette 0..7 (20h bytes each)  ; in Icon/Title
      1120h 80h   Icon Animation Sequence (16bit tokens)        ;/
      11A0h 2E60h Garbage (random values, maybe due to eMMC decryption)

The feature is used by some Brain Age Express games (for example, Brain Age Express Sudoku: 'title\00030004\4b4e3945\data\banner.sav').
The feature does probably work only for DSiware titles (unless there are any DSi carts with SD/MMC access enabled; or unless there is a feature for storing similar data in cartridge memory).

DS Cartridge Protocol

Communication with Cartridge ROM relies on sending 8 byte commands to the cartridge, after the sending the command, a data stream can be received from the cartridge (the length of the data stream isn't fixed, below descriptions show the default length in brackets, but one may receive more, or less bytes, if desired).
Cartridge Memory Map

      0000000h-0000FFFh Header (unencrypted)
      0001000h-0003FFFh Not read-able (zero filled in ROM-images)
      0004000h-0007FFFh Secure Area, 16KBytes (first 2Kbytes with extra encryption)
      0008000h-...      Main Data Area

DSi cartridges are split into a NDS area (as above), and a new DSi area:

      XX00000h XX02FFFh DSi Not read-able (XX00000h=first megabyte after NDS area)
      XX03000h-XX06FFFh DSi ARM9i Secure Area (usually with modcrypt encryption)
      XX07000h-...      DSi Main Data Area

Cartridge memory must be copied to RAM (the CPU cannot execute code in ROM).
Command Summary, Cmd/Reply-Encryption Type, Default Length

      Command/Params    Expl.                             Cmd  Reply Len
      -- Unencrypted Load --
      9F00000000000000h Dummy (read HIGH-Z bytes)         RAW  RAW   2000h
      0000000000000000h Get Cartridge Header              RAW  RAW   200h DSi:1000h
      9000000000000000h 1st Get ROM Chip ID               RAW  RAW   4
      A000000000000000h Get 3DS encryption type (3DS)     RAW  RAW   4
      00aaaaaaaa000000h Unencrypted Data (debug ver only) RAW  RAW   200h
      3Ciiijjjxkkkkkxxh Activate KEY1 Encryption (NDS)    RAW  RAW   0
      3Diiijjjxkkkkkxxh Activate KEY1 Encryption (DSi)    RAW  RAW   0
      3E00000000000000h Activate 16-byte commands (3DS)   RAW  RAW   0
      -- Secure Area Load --
      4llllmmmnnnkkkkkh Activate KEY2 Encryption Mode     KEY1 FIX   910h+0
      1lllliiijjjkkkkkh 2nd Get ROM Chip ID               KEY1 KEY2  910h+4
      xxxxxxxxxxxxxxxxh Invalid - Get KEY2 Stream XOR 00h KEY1 KEY2  910h+...
      2bbbbiiijjjkkkkkh Get Secure Area Block (4Kbytes)   KEY1 KEY2  910h+10A8h
      6lllliiijjjkkkkkh Optional KEY2 Disable             KEY1 KEY2  910h+?
      Alllliiijjjkkkkkh Enter Main Data Mode              KEY1 KEY2  910h+0
      -- Main Data Load --
      B7aaaaaaaa000000h Encrypted Data Read               KEY2 KEY2  200h
      B800000000000000h 3rd Get ROM Chip ID               KEY2 KEY2  4
      xxxxxxxxxxxxxxxxh Invalid - Get KEY2 Stream XOR 00h KEY2 KEY2  ...
      B500000000000000h Whatever NAND related? (DSi?)     KEY2 KEY2  0
      D600000000000000h Whatever NAND related? (DSi?)     KEY2 KEY2  4

The parameter digits contained in above commands are:

      aaaaaaaa     32bit ROM address (command B7 can access only 8000h and up)
      bbbb         Secure Area Block number (0004h..0007h for addr 4000h..7000h)
      x,xx         Random, not used in further commands (DSi: always zero)
      iii,jjj,llll Random, must be SAME value in further commands
      kkkkk        Random, must be INCREMENTED after FURTHER commands
      mmm,nnn      Random, used as KEY2-encryption seed

++++ Unencrypted Commands (First Part of Boot Procedure) ++++
Cartridge Reset
The /RES Pin switches the cartridge into unencrypted mode. After reset, the first two commands (9Fh and 00h) are transferred at 4MB/s CLK rate.
9F00000000000000h (2000h) - Dummy
Dummy command send after reset, returns endless stream of HIGH-Z bytes (ie. usually receiving FFh, immediately after sending the command, the first 1-2 received bytes may be equal to the last command byte).
0000000000000000h (200h) (DSi:1000h) - Get Header
Returns RAW unencrypted cartridge header, repeated every 1000h bytes. The interesting area are the 1st 200h bytes, the rest is typically zero filled (except on DSi carts, which do use the whole 1000h bytes).
The Gamecode header entry is used later on to initialize the encryption. Also, the ROM Control entries define the length of the KEY1 dummy periods (typically 910h clocks), and the CLK transfer rate for further commands (typically faster than the initial 4MB/s after power up).
9000000000000000h (4) - 1st Get ROM Chip ID
Returns RAW unencrypted Chip ID (eg. C2h,0Fh,00h,00h), repeated every 4 bytes.

      1st byte - Manufacturer (eg. C2h=Macronix) (roughly based on JEDEC IDs)
      2nd byte - Chip size (00h..7Fh: (N+1)Mbytes, F0h..FFh: (100h-N)*256Mbytes?)
      3rd byte - Flags (see below)
      4th byte - Flags (see below)

The Flag Bits in 3th byte can be

      0   Maybe Infrared flag? (in case ROM does contain on-chip infrared stuff)
      1   Unknown (set in some 3DS carts)
      2-7 Zero

The Flag Bits in 4th byte can be

      0-2 Zero
      3   Seems to be NAND flag (0=ROM, 1=NAND) (observed in only ONE cartridge)
      4   3DS Flag (0=NDS/DSi, 1=3DS)
      5   Zero   ... set in ... DSi-exclusive games? (support cmd B5h/D6h ?)
      6   DSi flag (0=NDS/3DS, 1=DSi)
      7   Cart Protocol Variant (0=older/smaller carts, 1=newer/bigger carts)

Existing/known ROM IDs are:

      C2h,07h,00h,00h NDS Macronix 8MB ROM  (eg. DS Vision)
      AEh,0Fh,00h,00h NDS Noname   16MB ROM (eg. Meine Tierarztpraxis)
      C2h,0Fh,00h,00h NDS Macronix 16MB ROM (eg. Metroid Demo)
      C2h,1Fh,00h,00h NDS Macronix 32MB ROM (eg. Over the Hedge)
      C2h,1Fh,00h,40h DSi Macronix 32MB ROM (eg. Art Academy, TWL-VAAV, SystemFlaw)
      80h,3Fh,01h,E0h ?            64MB ROM+Infrared (eg. Walk with Me, NTR-IMWP)
      AEh,3Fh,00h,E0h DSi Noname   64MB ROM (eg. de Blob 2, TWL-VD2V)
      C2h,3Fh,00h,00h NDS Macronix 64MB ROM (eg. Ultimate Spiderman)
      C2h,3Fh,00h,40h DSi Macronix 64MB ROM (eg. Crime Lab, NTR-VAOP)
      80h,7Fh,00h,80h NDS SanDisk  128MB ROM (DS Zelda, NTR-AZEP-0)
      80h,7Fh,01h,E0h ?            128MB ROM+Infrared? (P-letter Soul Silver, IPGE)
      C2h,7Fh,00h,80h NDS Macronix 128MB ROM (eg. Spirit Tracks, NTR-BKIP)
      C2h,7Fh,00h,C0h DSi Macronix 128MB ROM (eg. Cooking Coach/TWL-VCKE)
      ECh,7Fh,00h,88h NDS Samsung  128MB NAND (eg. Warioware D.I.Y.)
      ECh,7Fh,01h,88h NDS Samsung? 128MB NAND+What? (eg. Jam with the Band, UXBP)
      ECh,7Fh,00h,E8h DSi Samsung? 128MB NAND (eg. Face Training, USKV)
      80h,FFh,80h,E0h NDS          256MB ROM (Kingdom Hearts - Re-Coded, NTR-BK9P)
      C2h,FFh,01h,C0h DSi Macronix 256MB ROM+Infrared? (eg. P-Letter White)
      C2h,FFh,00h,80h NDS Macronix 256MB ROM (eg. Band Hero, NTR-BGHP)
      C2h,FEh,01h,C0h DSi Macronix 512MB ROM+Infrared? (eg. P-Letter White 2)
      C2h,FEh,00h,90h 3DS Macronix probably 512MB? ROM (eg. Sims 3)
      45h,FAh,00h,90h 3DS SunDisk? maybe... 1.5GB? ROM (eg. Starfox)
      C2h,F8h,00h,90h 3DS Macronix maybe... 2GB?   ROM (eg. Kid Icarus)
      C2h,7Fh,00h,90h 3DS Macronix 128MB ROM CTR-P-AENJ MMinna no Ennichi
      C2h,FFh,00h,90h 3DS Macronix 256MB ROM CTR-P-AFSJ Pro Yakyuu Famista 2011
      C2h,FEh,00h,90h 3DS Macronix 512MB ROM CTR-P-AFAJ Real 3D Bass FishingFishOn
      C2h,FAh,00h,90h 3DS Macronix 1GB ROM CTR-P-ASUJ Hana to Ikimono Rittai Zukan
      C2h,FAh,02h,90h 3DS Macronix 1GB ROM CTR-P-AGGW Luigis Mansion 2 ASiA CHT
      C2h,F8h,00h,90h 3DS Macronix 2GB ROM CTR-P-ACFJ Castlevania - Lords of Shadow
      C2h,F8h,02h,90h 3DS Macronix 2GB ROM CTR-P-AH4J Monster Hunter 4
      AEh,FAh,00h,90h 3DS          1GB ROM CTR-P-AGKJ Gyakuten Saiban 5
      AEh,FAh,00h,98h 3DS          1GB NAND CTR-P-EGDJ Tobidase Doubutsu no Mori
      45h,FAh,00h,90h 3DS          1GB ROM CTR-P-AFLJ Fantasy Life
      45h,F8h,00h,90h 3DS          2GB ROM CTR-P-AVHJ Senran Kagura Burst - Guren
      C2h,F0h,00h,90h 3DS Macronix 4GB ROM CTR-P-ABRJ Biohazard Revelations
      FFh,FFh,FFh,FFh None (no cartridge inserted)

The Samsung NAND chip appears to use a slightly different protocol (seems as if it allows to read ROM header and ID only once, or as if it gets confused when reading more than 4 ID bytes, or so) (and of course, the protocol is somehow extended, allowing to write data to the NAND memory). The official JEDEC ID for Samsung would be "CEh", but for some reason, Samsung's NDS chip does spit out "ECh" as Maker ID.
ID "45h" ("SunDisk" according to a JEDEC ID list) might refer to "SanDisk"?
3Ciiijjjxkkkkkxxh (0) - Activate KEY1 Encryption Mode
The 3Ch command returns endless stream of HIGH-Z bytes, all following commands, and their return values, are encrypted. The random parameters iii,jjj,kkkkk must be re-used in further commands; the 20bit kkkkk value is to be incremented by one after each <further> command (it is <not> incremented after the 3Ch command).
3Diiijjjxkkkkkxxh (0) - Activate KEY1 Encryption Mode and Unlock DSi Mode
Same as command 3Ch (but with different initial 1048h-byte encryption values), and works only on DSi carts. Command 3Dh is unlocking two features on DSi carts:

      1) Command 2bbbbiiijjjkkkkkh loads ARM9i secure area (instead of ARM9 area)
      2) Command B7aaaaaaaa000000h allows to read the 'whole' cartridge space

Without command 3Dh, DSi carts will allow to read only the first some megabytes (for example, the first 11 Mbyte of the System Flaw cartridge), and the remaining memory returns mirrors of "addr=8000h+(addr AND 1FFh)").
Note: After reset, the cartridge protocol allows to send only either one of the 3Ch/3Dh commands (DSi consoles can control the cartridge reset pin, so they can first send 3Ch and read the normal secure area, then issue a reset and 3Dh and read the DSi secure area) (on a NDS one could do the same by ejecting/inserting the cartridge instead of toggling the reset pin).
++++ KEY1 Encrypted Commands (2nd Part of Boot procedure) ++++
4llllmmmnnnkkkkkh (910h) - Activate KEY2 Encryption Mode
KEY1 encrypted command, parameter mmmnnn is used to initialize the KEY2 encryption stream. Returns 910h dummy bytes (which are still subject to old KEY2 settings; at pre-initialization time, this is fixed: HIGH-Z, C5h, 3Ah, 81h, etc.). The new KEY2 seeds are then applied, and the first KEY2 byte is then precomputed. The 910h dummy stream is followed by that precomputed byte value endless repeated (this is the same value as that "underneath" of the first HIGH-Z dummy-byte of the next command).
Secure1000h: Returns repeated FFh bytes (instead of the leading C5h, 3Ah, 81h, etc. stuff).
Secure1000h: Returns repeated FFh bytes (instead of the repeated precomputed value).
1lllliiijjjkkkkkh (914h) - 2nd Get ROM Chip ID / Get KEY2 Stream
KEY1 encrypted command. Returns 910h dummy bytes, followed by KEY2 encrypted Chip ID repeated every 4 bytes, which must be identical as for the 1st Get ID command. The BIOS randomly executes this command once or twice. Changing the first command byte to any other value returns an endless KEY2 encrypted stream of 00h bytes, that is the easiest way to retrieve encryption values and to bypass the copyprotection.
2bbbbiiijjjkkkkkh (19B8h) - Get Secure Area Block
KEY1 encrypted command. Used to read a secure area block (bbbb in range 0004h..0007h for addr 4000h..7000h) (or, after sending command 3Dh on a DSi: bbbb in range 0004h..0007h for addr XX03000h..XX06000h).
Each block is 4K, so it requires four Get Secure Area commands to receive the whole Secure Area (ROM locations 4000h-7FFFh), the BIOS is reading these blocks in random order.
Normally (if the upper bit of the Chip ID is set): Returns 910h dummy bytes, followed by 200h KEY2 encrypted Secure Area bytes, followed by 18h KEY2 encrypted 00h bytes, then the next 200h KEY2 encrypted Secure Area bytes, again followed by 18h KEY2 encrypted 00h bytes, and so on. That stream is repeated every 10C0h bytes (8x200h data bytes, plus 8x18h zero bytes).
Alternately (if the upper bit of the Chip ID is zero): Returns 910h dummy bytes, followed by 1000h KEY2 encrypted Secure Area bytes, presumably followed by 18h bytes, too.
Aside from above KEY2 encryption (which is done by hardware), the first 2K of the NDS Secure Area is additionally KEY1 encrypted; which must be resolved after transfer by software (and the DSi Secure Area is usually modcrypted, as specified in the cartridge header).
6lllliiijjjkkkkkh (0) - Optional KEY2 Disable
KEY1 encrypted command. Returns 910h dummy bytes (which are still KEY2 affected), followed by endless stream of RAW 00h bytes. KEY2 encryption is disabled for all following commands.
This command is send only if firmware[18h] matches encrypted string "enPngOFF", and ONLY if firmware get_crypt_keys had completed BEFORE completion of secure area loading, this timing issue may cause unstable results.
Alllliiijjjkkkkkh (910h) - Enter Main Data Mode
KEY1 encrypted command. Returns 910h dummy bytes, followed by endless KEY2 encrypted stream of 00h bytes. All following commands are KEY2 encrypted.
++++ KEY2 Encrypted Commands (Main Data Transfer) ++++
B7aaaaaaaa000000h (200h) - Get Data
KEY2 encrypted command. The desired ROM address is specifed, MSB first, in parameter bytes (a). Returned data is KEY2 encrypted.
There is no alignment restriction for the address. However, the datastream wraps to the begin of the current 4K block when address+length crosses a 4K boundary (1000h bytes).
The command can be used only for addresses 8000h and up. Addresses 0..7FFFh are silently redirected to address "8000h+(addr AND 1FFh)". DSi cartridges will also reject XX00000h..XX06FFFh in the same fashion (and also XX07000h and up if the DSi cartridge isn't unlocked via command 3Dh).
Addresses that do exceed the ROM size do mirror to the valid address range (that includes mirroring non-loadable regions like 0..7FFFh to "8000h+(addr AND 1FFh)"; some newer games are using this behaviour for some kind of anti-piracy checks).
B800000000000000h (4) - 3rd Get ROM Chip ID
KEY2 encrypted command. Returns KEY2 encrypted Chip ID repeated every 4 bytes.
xxxxxxxxxxxxxxxxh - Invalid Command
Any other command (anything else than above B7h and B8h) in KEY2 command mode causes communcation failures. The invalid command returns an endless KEY2 encrypted stream of 00h bytes. After the invalid command, the KEY2 stream is NOT advanced for further command bytes, further commands seems to return KEY2 encrypted 00h bytes, of which, the first returned byte appears to be HIGH-Z.
Ie. the cartridge seems to have switched back to a state similar to the KEY1-phase, although it doesn't seem to be possible to send KEY1 commands.
++++ Notes ++++
KEY1 Command Encryption / 910h Dummy Bytes
All KEY1 encrypted commands are followed by 910h dummy byte transfers, these 910h clock cycles are probably used to decrypt the command at the cartridge side; communication will fail when transferring less than 910h bytes.
The return values for the dummy transfer are: A single HIGH-Z byte, followed by 90Fh KEY2-encrypted 00h bytes. The KEY2 encryption stream is advanced for all 910h bytes, including for the HIGH-Z byte.
Note: Current cartridges are using 910h bytes, however, other carts might use other amounts of dummy bytes, the 910h value can be calculated based on ROM Control entries in cartridge header. For the KEY1 formulas, see:
DS Encryption by Gamecode/Idcode (KEY1)
KEY2 Command/Data Encryption
DS Encryption by Random Seed (KEY2)
Cart Protocol Variants (Chip ID.Bit31)
There are two protocol variants for NDS carts, indicated by Bit31 of the ROM Chip ID (aka bit7 of the 4th ID byte):

      1) Chip ID.Bit31=0  Used by older/smaller carts with up to 64MB ROM
      2) Chip ID.Bit31=1  Used by newer/bigger carts with 64MB or more ROM

The first variant (for older carts) is described above. The second second variant includes some differences for KEY1 encrypted commands:
GAPS: The commands have the same 910h-cycle gaps, but without outputting CLK pulses during those gaps (ie. used with ROMCTRL.Bit28=0) (the absence of the CLKs implies that there is no dummy data transferred during gaps, and accordingly, that the KEY2 stream isn't advanced during the 910h gap cycles).
REPEATED COMMANDS and SECURE AREA DELAY: All KEY1 encrypted commands must be sent TWICE (or even NINE times). First, send the command with 0-byte Data transfer length. Second, issue the Secure Area Delay (required; use the delay specified in cart header[06Eh]).
Third, send the command once again with 0-byte or 4-byte data transfer length (usually 0 bytes, or 4-bytes for Chip ID command), or sent it eight times with 200h-byte data transfer length (for the 1000h-byte secure area load command).
For those repeats, always resend exactly the same command (namely, kkkkk is NOT incremented during repeats, and there is no extra index needed to select 200h-byte portions within 1000h-byte blocks; the cartridge is automatically outputting the eight portions one after another).

DS Cartridge Backup

SPI Bus Backup Memory

      Type   Total Size  Page Size  Chip/Example      Game/Example
      EEPROM 0.5K bytes   16 bytes  ST M95040-W       (eg. Metroid Demo)
      EEPROM   8K bytes   32 bytes  ST M95640-W       (eg. Super Mario DS)
      EEPROM  64K bytes  128 bytes  ST M95512-W       (eg. Downhill Jam)
      FLASH  256K bytes  256 bytes  ST M45PE20        (eg. Skateland)
      FLASH  256K bytes             Sanyo LE25FW203T  (eg. Mariokart)
      FLASH  512K bytes  256 bytes  ST M25PE40?       (eg. which/any games?)
      FLASH  512K bytes             ST 45PE40V6       (eg. DS Zelda, NTR-AZEP-0)
      FLASH 1024K bytes             ST 45PE80V6       (eg. Spirit Tracks, NTR-BKIP)
      FLASH 8192K bytes             MX25L6445EZNI-10G (Art Academy only, TWL-VAAV)
      FRAM     8K bytes   No limit  ?                 (eg. which/any games?)
      FRAM    32K bytes   No limit  Ramtron FM25L256? (eg. which/any games?)

Lifetime Stats

      Type      Max Writes per Page    Data Retention
      EEPROM    100,000                40 years
      FLASH     100,000                20 years
      FRAM      No limit               10 years

SPI Bus Backup Memory is accessed via Ports 40001A0h and 40001A2h, see
DS Cartridge I/O Ports
Commands
For all EEPROM and FRAM types:

      06h WREN  Write Enable                Cmd, no parameters
      04h WRDI  Write Disable               Cmd, no parameters
      05h RDSR  Read Status Register        Cmd, read repeated status value(s)
      01h WRSR  Write Status Register       Cmd, write one-byte value
      9Fh RDID  Read JEDEC ID (not supported on EEPROM/FLASH, returns FFh-bytes)

For 0.5K EEPROM (8+1bit Address):

      03h RDLO  Read from Memory 000h-0FFh  Cmd, addr lsb, read byte(s)
      0Bh RDHI  Read from Memory 100h-1FFh  Cmd, addr lsb, read byte(s)
      02h WRLO  Write to Memory 000h-0FFh   Cmd, addr lsb, write 1..MAX byte(s)
      0Ah WRHI  Write to Memory 100h-1FFh   Cmd, addr lsb, write 1..MAX byte(s)

For 8K..64K EEPROM and for FRAM (16bit Address):

      03h RD    Read from Memory            Cmd, addr msb,lsb, read byte(s)
      02h WR    Write to Memory             Cmd, addr msb,lsb, write 1..MAX byte(s)

Note: MAX = Page Size (see above chip list) (no limit for FRAM).
For FLASH backup, commands should be same as for Firmware FLASH memory:
DS Firmware Serial Flash Memory
Status Register

      0   WIP  Write in Progress (1=Busy) (Read only) (always 0 for FRAM chips)
      1   WEL  Write Enable Latch (1=Enable) (Read only, except by WREN,WRDI)
      2-3 WP   Write Protect (0=None, 1=Upper quarter, 2=Upper Half, 3=All memory)

For 0.5K EEPROM:

      4-7 ONEs Not used (all four bits are always set to "1" each)

For 8K..64K EEPROM and for FRAM:

      4-6 ZERO Not used (all three bits are always set to "0" each)
      7   SRWD Status Register Write Disable (0=Normal, 1=Lock) (Only if /W=LOW)

WEL gets reset on Power-up, WRDI, WRSR, WRITE/LO/HI, and on /W=LOW.
The WRSR command allows to change ONLY the two WP bits, and the SRWD bit (if any), these bits are non-volatile (remain intact during power-down), respectively, the WIP bit must be checked to sense WRSR completion.
Detection (by examining hardware responses)
The overall memory type and bus-width can be detected by RDSR/RDID commands:

      RDSR  RDID          Type         (bus-width)
      FFh,  FFh,FFh,FFh   None         (none)
      F0h,  FFh,FFh,FFh   EEPROM       (with 8+1bit address bus)
      00h,  FFh,FFh,FFh   EEPROM/FRAM  (with 16bit address bus)
      00h,  xxh,xxh,xxh   FLASH        (usually with 24bit address bus)

And, the RD commands can be used to detect the memory size/mirrors (though that won't work if the memory is empty).
Pin-Outs for EEPROM and FRAM chips

      Pin Name Expl.
      1  /S    Chip Select
      2  Q     Data Out
      3  /W    Write-Protect (not used in NDS, wired to VCC)
      4  VSS   Ground
      5  D     Data In
      6  C     Clock
      7  /HOLD Transfer-pause (not used in NDS, wired to VCC)
      8  VCC   Supply 2.5 to 5.5V for M95xx0-W

FRAM (Ferroelectric Nonvolatile RAM) is fully backwards compatible with normal EEPROMs, but comes up with faster write/erase time (no delays), and with lower power consumption, and unlimited number of write/erase cycles. Unlike as for normal RAM, as far as I understand, the data remains intact without needing any battery.
Other special save memory

      DS Vision (NDS cart with microSD slot... and maybe ALSO with EEPROM?)
      Warioware D.I.Y. (uses a single NAND FLASH chip for both 'ROM' and 'SAVE')
        (the warioware chip is marked "SAMSUNG 004, KLC2811ANB-P204, NTR-UORE-0")
        (the warioware PCB is marked "DI X-7 C17-01")
      and, a few games are said to have "Flash - 64 Mbit" save memory?

DSi Internal eMMC and External SD Card
DSi cartridges are usually (maybe always) having SD/MMC access disabled, so they must stick using EEPROM/FLASH chips inside of the cartridges (which is required for NDS compatibility anyways).
However, DSiware games (downloaded from DSi Shop) are allowed to save data on eMMC, using "private.sav" or "public.sav" files in their data folder. The size of that files is preset in cartridge header.

DS Cartridge I/O Ports

The Gamecard bus registers can be mapped to NDS7 or NDS9 via EXMEMCNT, see
DS Memory Control
40001A0h - NDS7/NDS9 - AUXSPICNT - Gamecard ROM and SPI Control (R/W)

      0-1   SPI Baudrate        (0=4MHz/Default, 1=2MHz, 2=1MHz, 3=512KHz)
      2-5   Not used            (always zero)
      6     SPI Hold Chipselect (0=Deselect after transfer, 1=Keep selected)
      7     SPI Busy            (0=Ready, 1=Busy) (presumably Read-only)
      8-12  Not used            (always zero)
      13    NDS Slot Mode       (0=Parallel/ROM, 1=Serial/SPI-Backup)
      14    Transfer Ready IRQ  (0=Disable, 1=Enable) (for ROM, not for AUXSPI)
      15    NDS Slot Enable     (0=Disable, 1=Enable) (for both ROM and AUXSPI)

The "Hold" flag should be cleared BEFORE transferring the LAST data unit, the chipselect will be then automatically cleared after the transfer, the program should issue a WaitByLoop(12) on NDS7 (or longer on NDS9) manually AFTER the LAST transfer.
40001A2h - NDS7/NDS9 - AUXSPIDATA - Gamecard SPI Bus Data/Strobe (R/W)
The SPI transfer is started on writing to this register, so one must <write> a dummy value (should be zero) even when intending to <read> from SPI bus.

      0-7  Data
      8-15 Not used (always zero)

During transfer, the Busy flag in AUXSPICNT is set, and the written DATA value is transferred to the device (via output line), simultaneously data is received (via input line). Upon transfer completion, the Busy flag goes off, and the received value can be then read from AUXSPIDATA, if desired.
40001A4h - NDS7/NDS9 - ROMCTRL - Gamecard Bus ROMCTRL (R/W)

      Bit   Expl.
      0-12  KEY1 gap1 length  (0-1FFFh) (forced min 08F8h by BIOS) (leading gap)
      13    KEY2 encrypt data (0=Disable, 1=Enable KEY2 Encryption for Data)
      14     "SE" Unknown? (usually same as Bit13) (does NOT affect timing?)
      15    KEY2 Apply Seed   (0=No change, 1=Apply Encryption Seed) (Write only)
      16-21 KEY1 gap2 length  (0-3Fh)   (forced min 18h by BIOS) (200h-byte gap)
      22    KEY2 encrypt cmd  (0=Disable, 1=Enable KEY2 Encryption for Commands)
      23    Data-Word Status  (0=Busy, 1=Ready/DRQ) (Read-only)
      24-26 Data Block size   (0=None, 1..6=100h SHL (1..6) bytes, 7=4 bytes)
      27    Transfer CLK rate (0=6.7MHz=33.51MHz/5, 1=4.2MHz=33.51MHz/8)
      28    KEY1 Gap CLKs (0=Hold CLK High during gaps, 1=Output Dummy CLK Pulses)
      29    RESB Release Reset (0=Reset, 1=Release) (cannot be cleared once set)
      30     "WR"   Unknown, maybe data-write? (usually 0) (read/write-able)
      31    Block Start/Status (0=Ready, 1=Start/Busy) (IRQ See 40001A0h/Bit14)

The cartridge header is booted at 4.2MHz CLK rate, and following transfers are then using ROMCTRL settings specified in cartridge header entries [060h] and [064h], which are usually using 6.7MHz CLK rate for the main data transfer phase (whereof, older MROM carts can actually transfer 6.7Mbyte/s, but newer 1T-ROM carts default to reading 200h-byte blocks with gap1=657h, thus reaching only 1.6Mbyte/s).
Transfer length of null, four, and 200h..4000h bytes are supported by the console, however, retail cartridges cannot cross 1000h-byte boundaries.
Default cart header entries

      hdr[60h]   hdr[64h]   hdr[6Eh]
      00586000h  001808F8h  051Eh     ;older/faster MROM
      00416657h  081808F8h  0D7Eh     ;newer/slower 1T-ROM
      ?          ?          ?         ;whatever NAND

Older/Faster MROM
The romctrl values in cartheader[60h,64h] are okay, but the secure delay in [6Eh] is nonsense (should be zero).
Misdeclared MROM
Some carts like SystemFlaw and BiggestLoser are actually containing MROM chips despite of having 1T-ROM values in cart header (gap1=657h is making loading insane slow, gap2=01h causes errors on 1000h-byte blocks, and secure.clk=4.2MHz is slowing down secure area loading, combined with even slower secure area delay despite of not needing any delay for MROM).
As the cart header entries are wrong, some other detection is needed: This can be probably done by checking ChipID.bit31 (or otherwise by testing if 1000h-block reading works with gap1=01h, if so, then it's 1T-ROM).
Newer/Slower 1T-ROM
Actual 1T-ROM carts can be very slow, especially when using the insane cart header values and default firmware blocksize of 200h bytes which drops loading speed from 6.7Mbytes/s to 1.6Mbyte/s (as workaround, use gap1=180h, blocksize=1000h, also secure area delay should be 400h, not D7Eh) (tested/working for CookingCoach, unknown if that timings work for all other carts).
NAND
Some cartridges are said to contain NAND memory, unknown if that's accessed with the normal ROM reading commands, and if so, with which timings.
Cart Reset
Reset flag in bit29 can be set once only (to release reset), the only way to clear the bit is power-off. However, there are some ways to issue resets:
1) On NDS: Manually eject/insert the cart (that won't affect bit29, but the cart will reset itself anyways upon power loss) (eject on DSi will power-off the cart slot).
2) If one of the two ROMCTRL registers (on ARM7 and ARM9) is still zero: Temporarily toggle ARM7/ARM9 cart access via EXMEMCNT on ARM9 side.
3) On DSi: If the 2nd cart slot ROMCTRL register (40021A4h) is still zero: Temporarily swap 1ns/2nd cart slot via SCFG_MC.bit15 on ARM7 side.
4) On DSi: Use SCFG_MC to toggle cart power off/on; this will actually reset bit29, the DSi firmware is actually using that method, but it's very slow (takes about 300ms, for the power-off wait, plus (unneccassary) hardcoded power-on delays).
40001A8h - NDS7/NDS9 - Gamecard bus 8-byte Command Out
The separate commands are described in the Cartridge Protocol chapter, however, once when the BIOS boot procedure has completed, one would usually only need command "B7aaaaaaaa000000h", for reading data (usually 200h bytes) from address aaaaaaaah (which should be usually aligned by 200h).

      0-7   1st Command Byte (at 40001A8h) (eg. B7h) (MSB)
      8-15  2nd Command Byte (at 40001A9h) (eg. addr bit 24-31)
      16-23 3rd Command Byte (at 40001AAh) (eg. addr bit 16-23)
      24-31 4th Command Byte (at 40001ABh) (eg. addr bit 8-15) (when aligned=even)
      32-39 5th Command Byte (at 40001ACh) (eg. addr bit 0-7)  (when aligned=00h)
      40-47 6th Command Byte (at 40001ADh) (eg. 00h)
      48-57 7th Command Byte (at 40001AEh) (eg. 00h)
      56-63 8th Command Byte (at 40001AFh) (eg. 00h) (LSB)

Observe that the command/parameter MSB is located at the smallest memory location (40001A8h), ie. compared with the CPU, the byte-order is reversed.
4100010h - NDS7/NDS9 - Gamecard bus 4-byte Data In (R)

      0-7   1st received Data Byte (at 4100010h)
      8-15  2nd received Data Byte (at 4100011h)
      16-23 3rd received Data Byte (at 4100012h)
      24-31 4th received Data Byte (at 4100013h)

After sending a command, data can be read from this register manually (when the DRQ bit is set), or by DMA (with DMASAD=4100010h, Fixed Source Address, Length=1, Size=32bit, Repeat=On, Mode=DS Gamecard).
40001B0h - 32bit - NDS7/NDS9 - Encryption Seed 0 Lower 32bit (W)
40001B4h - 32bit - NDS7/NDS9 - Encryption Seed 1 Lower 32bit (W)
40001B8h - 16bit - NDS7/NDS9 - Encryption Seed 0 Upper 7bit (bit7-15 unused)
40001BAh - 16bit - NDS7/NDS9 - Encryption Seed 1 Upper 7bit (bit7-15 unused)
These registers are used by the NDS7 BIOS to initialize KEY2 encryption (and there's normally no need to change that initial settings). Writes to the Seed registers do not have direct effect on the internal encryption registers, until the Seed gets applied by writing "1" to ROMCTRL.Bit15.

     For more info:

DS Encryption by Random Seed (KEY2)
Note: There are <separate> Seed registers for both NDS7 and NDS9, which can be applied by ROMCTRL on NDS7 and NDS9 respectively (however, once when applied to the internal registers, the new internal setting is used for <both> CPUs).

DS Cartridge NitroROM and NitroARC File Systems

The DS hardware, BIOS, and Firmware do NOT contain any built-in filesystem functions. The ARM9/ARM7 boot code (together max 3903KB), and Icon/Title information are automatically loaded on power-up.
Programs that require to load additional data from cartridge ROM may do that either by implementing whatever functions to translate filenames to ROM addresses, or by reading from ROM directly.
NitroROM
The NitroROM Filesystem is used by many NDS games (at least those that have been developed with Nintendo's tools). It's used for ROM Cartridges, and, on the DSi, it's also used for DSiWare games (in the latter case, NitroROM acts as a 2nd virtual filesystem inside of the DSi's FAT16 filesystem).

      FNT = cart_hdr[040h]     ;\origin as defined in ROM cartridge header
      FAT = cart_hdr[048h]     ;/
      IMG = 00000000h          ;-origin at begin of ROM

Aside from using filenames, NitroROM files can be alternately accessed via Overlay IDs (see later on below).
NitroARC (Nitro Archive)
NARC Files are often found inside of NitroROM Filesystems (ie. NARC is a second virtual filesystem, nested inside of the actual filesystem). The NARC Format is very similar to the NitroROM Format, but with additional Chunk Headers (instead of the Cartridge ROM Header).

      ...  ...  Optional Header (eg. compression header, or RSA signature)
      000h 4    Chunk Name "NARC" (Nitro Archive)                   ;\
      004h 2    Byte Order (FFFEh) (unlike usually, not FEFFh)      ;
      006h 2    Version (0100h)                                     ; NARC
      008h 4    File Size (from "NARC" ID to end of file)           ; Header
      00Ch 2    Chunk Size (0010h)                                  ;
      00Eh 2    Number of following chunks (0003h)                  ;/
      010h 4    Chunk Name "BTAF" (File Allocation Table Block)     ;\
      014h 4    Chunk Size (including above chunk name)             ; File
      018h 2    Number of Files                                     ; Allocation
      01Ah 2    Reserved (0000h)                                    ; Table
      01Ch ...  FAT (see below)                                     ;/
      ...  4    Chunk Name "BTNF" (File Name Table Block)           ;\
      ...  4    Chunk Size (including above chunk name)             ; File Name
      ...  ...  FNT (see below)                                     ; Table
      ...  ..   Padding for 4-byte alignment (FFh-filled, if any)   ;/
      ...  4    Chunk Name "GMIF" (File Image Block)                ;\
      ...  4    Chunk Size (including above chunk name)             ; File Data
      ...  ...  IMG (File Data)                                     ;/

NARCless variant
There are a few NARC archives with crippled header, without "NARC" string (eg. rom:\dwc\utility.bin in Over the Hedge, Downhill Jam, and Tony Hawk's Skateland).

      000h 4   FNT Filename Table Offset (always at 10h)
      004h 4   FNT Filename Table Size
      008h 4   FAT Allocaton Table Offset (at above Offset+Size+Padding)
      00Ch 4   FAT Allocaton Table Size
      010h ..  FNT Filename Table Data
      ...  ..  FAT Allocaton Table Data
      ...  ..  IMG File Data

The offsets in FAT are relative to IMG=0 (as if IMG would start at begin of file).
File Allocation Table (FAT) (base/size defined in cart header)
Contains ROM addresses for up to 61440 files (File IDs 0000h and up).

      Addr Size Expl.
      00h  4    Start address (originated at IMG base) (0=Unused Entry)
      04h  4    End address   (Start+Len)              (0=Unused Entry)

For NitroROM, addresses must be after Secure Area (at 8000h and up).
For NitroARC, addresses can be anywhere in the IMG area (at 0 and up).
Directories are fully defined in FNT area, and do not require FAT entries.
File Name Table (FNT) (base/size defined in cart header)
Consists of the FNT Directory Table, followed by one or more FNT Sub-Tables.
To interprete the directory tree: Start at the 1st Main-Table entry, which is referencing to a Sub-Table, any directories in the Sub-Table are referencing to Main-Table entries, which are referencing to further Sub-Tables, and so on.
FNT Directory Main-Table (base=FNT+0, size=[FNT+06h]*8)
Consists of a list of up to 4096 directories (Directory IDs F000h and up).

      Addr Size Expl.
      00h  4    Offset to Sub-table             (originated at FNT base)
      04h  2    ID of first file in Sub-table   (0000h..EFFFh)

For first entry (ID F000h, root directory):

      06h  2    Total Number of directories     (1..4096)

Further entries (ID F001h..FFFFh, sub-directories):

      06h  2    ID of parent directory (F000h..FFFEh)

FNT Sub-tables (base=FNT+offset, ends at Type/Length=00h)
Contains ASCII names for all files and sub-directories within a directory.

      Addr Size Expl.
      00h  1    Type/Length
                  01h..7Fh File Entry          (Length=1..127, without ID field)
                  81h..FFh Sub-Directory Entry (Length=1..127, plus ID field)
                  00h      End of Sub-Table
                  80h      Reserved
      01h  LEN  File or Sub-Directory Name, case-sensitive, without any ending
                  zero, ASCII 20h..7Eh, except for characters \/?"<>*:;|

Below for Sub-Directory Entries only:

      LEN+1 2    Sub-Directory ID (F001h..FFFFh) ;see FNT+(ID AND FFFh)*8

File Entries do not have above ID field. Instead, File IDs are assigned in incrementing order (starting at the "First ID" value specified in the Directory Table).
ARM9 and ARM7 Overlay Tables (OVT) (base/size defined in cart header)
Somehow related to Nintendo's compiler, allows to assign compiler Overlay IDs to filesystem File IDs, and to define additional information such like load addresses.

      Addr Size Expl.
      00h  4    Overlay ID
      04h  4    RAM Address ;Point at which to load
      08h  4    RAM Size    ;Amount to load
      0Ch  4    BSS Size    ;Size of BSS data region
      10h  4    Static initialiser start address
      14h  4    Static initialiser end address
      18h  4    File ID  (0000h..EFFFh)
      1Ch  4    Reserved (zero)

Cartridge Header
The base/size of FAT, FNT, OVT areas is defined in cartridge header,
DS Cartridge Header

DS Cartridge PassMe/PassThrough

PassMe is an adapter connected between the DS and an original NDS cartridge, used to boot unencrypted code from a flash cartridge in the GBA slot, it replaces the following entries in the original NDS cartridge header:

      Addr  Siz Patch
      004h  4   E59FF018h  ;opcode LDR PC,[027FFE24h] at 27FFE04h
      01Fh  1   04h        ;set autostart bit
      022h  1   01h        ;set ARM9 rom offset to nn01nnnnh (above secure area)
      024h  4   027FFE04h  ;patch ARM9 entry address to endless loop
      034h  4   080000C0h  ;patch ARM7 entry address in GBA slot
      15Eh  2   nnnnh      ;adjust header crc16

After having verified the encrypted chip IDs (from the original cartridge), the console thinks that it has successfully loaded a NDS cartridge, and then jumps to the (patched) entrypoints.
GBA Flashcard Format
Although the original PassMe requires only the entrypoint, PassMe programs should additionally contain one (or both) of the ID values below, allowing firmware patches to identify & start PassMe games without real PassMe hardware.

      0A0h  GBA-style Title    ("DSBooter")
      0ACh  GBA-style Gamecode ("PASS")
      0C0h  ARM7 Entrypoint    (32bit ARM code)

Of course, that applies only to early homebrew programs, newer games should use normal NDS cartridge headers.
ARM9 Entrypoint
The GBA-slot access rights in the EXMEMCNT register are initially assigned to the ARM7 CPU, so the ARM9 cannot boot from the flashcard, instead it is switched into an endless loop in Main RAM (which contains a copy of the cartridge header at 27FFE00h and up). The ARM7 must thus copy ARM9 code to Main RAM, and then set the ARM9 entry address by writing to [027FFE24h].

DS Cartridge GBA Slot

Aside from the 17-pin NDS slot, the DS also includes a 32-pin GBA slot. This slot is used for GBA backwards compatibility mode. Additionally, in DS mode, it can be as expansion port, or for importing data from GBA games.

      NDS:     Normal 32pin slot
      DS Lite: Short 32pin slot (GBA cards stick out)
      DSi:     N/A (dropped support for GBA carts, and for DS-expansions)

In DS mode, ROM, SRAM, FLASH backup, and whatever peripherals contained in older GBA cartridges can be accessed (almost) identically as in GBA mode,
GBA Cartridges
Addressing
In DS mode, only one ROM-region is present at 8000000h-9FFFFFFh (ie. without the GBA's mirrored WS1 and WS2 regions at A000000h-DFFFFFFh). The expansion region (for SRAM/FLASH/etc) has been moved from E000000h-E00FFFFh (GBA-mode) to A000000h-A00FFFFh (DS-mode).
Timings
GBA timings are specified as "waitstates" (excluding 1 access cycle), NDS timings are specified as (total) "access time". And, the NDS bus-clock is twice as fast as for GBA. So, for "N" GBA waitstates, the NDS access time should be "(N+1)*2". Timings are controlled via NDS EXMEMCNT instead GBA WAITCNT,
DS Memory Control - Cartridges and Main RAM
GBA EEPROM
EEPROMs in GBA carts cannot be accessed in DS mode. The EEPROMs should be accessed with 8 waits on GBA, ie. 18 cycles on NDS on both 1st/2nd access. But, 2nd access is restricted to max 6 cycles in NDS mode, which is ways too fast.

DS Cart Rumble Pak

DS Rumble Option Pak
The Rumble Pak comes bundled with Metroid Prime Pinball. It contains a small actuator made by ALPS to make it rumble. The original device (NTR-008) is sized like a normal GBA cartridge, and there's also shorter variant for the DS-Lite (USG-006).
The rumble pak is pretty simple internally, it only wires up to a few pins on the GBA Cartridge Port:

      VCC, GND, /WR, AD1, and IRQ (grounded)

AD1 runs into a little 8 pin chip, which is probably just a latch on the rising edge of /WR. A line runs from this chip to a transistor that is directly connected to the actuator. The only other chip on the board is a 5 pin jobber, probably a power component.
For detection, AD1 seems to be pulled low when reading from it, the other AD lines are open bus (containing the halfword address), so one can do:

      for i=0 to 0FFFh
        if halfword[8000000h+i*2]<>(i and FFFDh) then <not_a_ds_rumble_pak>
      next i

The actuator doesn't have an on/off setting like a motor, it rumbles when you switch it between the two settings. Switch frequently for a fast rumble, and fairly slowly for more of a 'tick' effect. That should be done via timer irq:

      rumble_state = rumble_state xor 0002h
      halfword[8000000h]=rumble_state

Unknown if one of the two states has higher power-consumption than the other, ie. if it's a "pull/release" mechanism, if so, then disabling rumble should be done by using the "release" state, which would be AD1=0, or AD1=1...?
Note: The v3 firmware can detect the Rumble Pak as an option pak, but it does not provide an enable/disable rumble option in the alarm menu.
Other DS Rumble device
There's also another DS add-on with rumble. That device uses AD8 (instead AD1) to control rumble, and, it's using a classic motor (ie. it's rumbling while and as long as the latched AD8 value is "1").
DS Cart Slider with Rumble
GBA Rumble Carts
There are also a few GBA games that contain built-in Rumble, and which could be used by NDS games as well. To be user friendly, best support both types.
GBA Cart Rumble

DS Cart Slider with Rumble

Add-on device for the japanese title Magukiddo. The optical sensor is attached underneath of the console (connected to the GBA slot).
The sensor is an Agilent ADNS-2030 Low Power Optical Mouse Sensor (16pin DIP chip with built-in optical sensor, and external LED light source) with two-wire serial bus (CLK and DTA).
ADNS-2030 Registers (write 1 byte index, then read/write 1 byte data)
Index (Bit7=Direction; 0=Read, 1=Write):

      00h Product_ID (R) (03h)
      01h Revision_ID (R) (10h=Rev. 1.0) (20h=Used in DS-option-pak)
      02h Motion/Status Flags (R)
      03h Delta_X (R) (signed 8bit) (automatically reset to 00h after reading)
      04h Delta_Y (R) (signed 8bit) (automatically reset to 00h after reading)
      05h SQUAL (R) (surface quality) (unsigned 8bit)
      06h Average_Pixel (R) (unsigned 6bit, upper 2bit unused)
      07h Maximum_Pixel (R) (unsigned 6bit, upper 2bit unused)
      08h Reserved
      09h Reserved
      0Ah Configuration_bits (R/W)
      0Bh Reserved
      0Ch Data_Out_Lower (R)
      0Dh Data_Out_Upper (R)
      0Eh Shutter_Lower (R)
      0Fh Shutter_Upper (R)
      10h Frame_Period_Lower (R/W)
      11h Frame_Period_Upper (R/W)

Motion/Status Flags:

      7 Motion since last report or PD (0=None, 1=Motion occurred)
      6 Reserved
      5 LED Fault detected (0=No fault,  1=Fault detected)
      4 Delta Y Overflow (0=No overflow, 1=Overflow occured)
      3 Delta X Overflow (0=No overflow, 1=Overflow occured)
      2 Reserved
      1 Reserved
      0 Resolution in counts per inch (0=400, 1=800)

Configuration_bits:

      7 Reset Power up defaults (W) (0=No, 1=Reset)
      6 LED Shutter Mode (0=LED always on, 1=LED only on when shutter is open)
      5 Self Test (W) (0=No, 1=Perform all self tests)
      4 Resolution in counts per inch (0=400, 1=800)
      3 Dump 16x16 Pixel bitmap (0=No, 1=Dump via Data_Out ports)
      2 Reserved
      1 Reserved
      0 Sleep Mode (0=Normal/Sleep after 1 second, 1=Always awake)
                              _______
                             |74273  |
      /WR -----------------> |CLK    |                       _____
      AD1/SIO CLK ---------> |D1   Q1|--------------> CLK   |74125|
      AD2 power control ---> |D2   Q2|--->     ____         |     |
      AD3/SIO DIR ---------> |D3   Q3|------o-|7400\________|/EN  |
      AD8 rumble on/off ---> |D?   Q?|--->  '-|____/        |     |
      AD0/SIO DTA ----o----> |D5   Q5|----------------------|A   Y|--o--DTA
                      |      |_______|                      |- - -|  |
              ____    '-------------------------------------|Y   A|--'
      /RD ---|7400\______ ____                              |     |
      /RD ---|____/      |7400\_____________________________|/EN  |
      A19 _______________|____/                             |_____|

7400 Quad NAND Gate, 74273 8bit Latch
AD0 Optical Sensor Serial Data (0=Low, 1=High)
AD1 Optical Sensor Serial Clock (0=Low, 1=High)
AD2 Optical Sensor Power (0=Off, 1=On)
AD3 Optical Sensor Serial Direction (0=Read, 1=Write)
AD8 Rumble Motor (0=Off, 1=On)
Thanks: Daniel Palmer

DS Cart Expansion RAM

DS Memory Expansions
There are several RAM expansions for the NDS. The RAM cartridge connects to the GBA slot; can can be then accessed from cartridges in the DS slot.

      Opera         (8MB RAM) (official RAM expansion for Opera browser)
      EZ3/4/3-in-1  (8-16MB RAM, plus FLASH, plus rumble)
      Supercard     (32MB)
      M3            (32MB)
      G6            (32MB)

The recommended access time (waitstates) for all memory types is unknown. Unknown which programs do use these expansions for which purposes (aside from the Opera browser).
Thanks to Rick "Lick" Wong for info on detection and unlocking.
Opera / DS Memory Expansion Pak (NTR-011 or USG-007)

      base=9000000h, size=800000h (8MB)
      unlock=1, lock=0
      STRH [8240000h],lock/unlock

EZ

      base=8400000h, size=VAR (8MB..16MB)
      locking/unlocking/detection see below

Supercard

      base=8000000h, size=1FFFFFEh (32MB minus last two bytes?)
      unlock=5 (RAM_RW), lock=3 (MEDIA)
      STRH [9FFFFFEh],A55Ah
      STRH [9FFFFFEh],A55Ah
      STRH [9FFFFFEh],lock/unlock
      STRH [9FFFFFEh],lock/unlock

M3

      base=8000000h, size=2000000h (32MB)
      unlock=00400006h, lock=00400003h
      LDRH Rd,[8E00002h]
      LDRH Rd,[800000Eh]
      LDRH Rd,[8801FFCh]
      LDRH Rd,[800104Ah]
      LDRH Rd,[8800612h]
      LDRH Rd,[8000000h]
      LDRH Rd,[8801B66h]
      LDRH Rd,[8000000h+(lock/unlock)*2]
      LDRH Rd,[800080Eh]
      LDRH Rd,[8000000h]
      LDRH Rd,[80001E4h]
      LDRH Rd,[80001E4h]
      LDRH Rd,[8000188h]
      LDRH Rd,[8000188h]

G6

      base=8000000h, size=2000000h (32MB)
      unlock=6, lock=3
      LDRH Rd,[9000000h]
      LDRH Rd,[9FFFFE0h]
      LDRH Rd,[9FFFFECh]
      LDRH Rd,[9FFFFECh]
      LDRH Rd,[9FFFFECh]
      LDRH Rd,[9FFFFFCh]
      LDRH Rd,[9FFFFFCh]
      LDRH Rd,[9FFFFFCh]
      LDRH Rd,[9FFFF4Ah]
      LDRH Rd,[9FFFF4Ah]
      LDRH Rd,[9FFFF4Ah]
      LDRH Rd,[9200000h+(lock/unlock)*2]
      LDRH Rd,[9FFFFF0h]
      LDRH Rd,[9FFFFE8h]

Detection
For EZ, detection works as so:

     ez_ram_test:   ;Based on DSLinux Amadeus' detection
      ez_subfunc(9880000h,8000h) ;-SetRompage (OS mode)
      ez_subfunc(9C40000h,1500h) ;-OpenNorWrite
      [08400000h]=1234h          ;\
      if [08400000h]=1234h       ; test writability at 8400000h
        [8000000h]=4321h         ; and non-writability at 8000000h
        if [8000000h]<>4321h     ;
          return true            ;/
      ez_subfunc(9C40000h,D200h) ;CloseNorWrite
      ez_subfunc(9880000h,0160h) ;SetRompage (0160h)
      ez_subfunc(9C40000h,1500h) ;OpenNorWrite
      [8400000h]=1234h           ;\
      if [8400000h]=1234h        ; test writability at 8400000h
        return true              ;/
      return false               ;-failed
     ez_subfunc(addr,data):
      STRH [9FE0000h],D200h
      STRH [8000000h],1500h
      STRH [8020000h],D200h
      STRH [8040000h],1500h
      STRH [addr],data
      STRH [9FC0000h],1500h

For all other types (everything except EZ), simply verify that you can write (when unlocked), and that you can't (when locked).

DS Cart Unknown Extras

DS Cartridges with built-in Infrared Port
Some NDS and DSi games (those with NTR-Ixxx or TWL-Ixxx gamecodes) contain built-in Infrared ports; used to communicate with pedometers.
The IR-port is accessed via certain SPI bus commands; that bus is also shared to access FLASH memory via other commands.
The FLASH chip seems to return a nonsense chip ID (maybe the cartridge is using uncommon FLASH memory, or maybe the ID command is redirected to the IR-port hardware).
The ROM chip does also respond with an uncommon ID (with one special bit set, which is possibly indicating the presenence of the IR-hardware) (maybe the IR-port is contained in the ROM chip, or maybe the SPI-bus sharing is handled inside of the ROM chip.
The IR-related SPI commands are mostly unknown. Except that: command 08h should return 55h (or some other non-FFh value), otherwise the game won't work in emulators; this might be some IR-status byte.
DS Cartridges with NAND memory
Some NDS games (eg. Warioware D.I.Y.) contain NAND memory, this memory contains both the game and save memory (normal NDS games contain separate ROM and FLASH/EEPROM chips for that purposes) (the advantage is that NAND allows more storage than the usual FLASH chips).
The Warioware D.I.Y. PCB is marked "DI X-7 C17-01", and it does contain only one single chip, marked "SAMSUNG 004, KLC2811ANB-P204, NTR-UORE-0".
That NAND chip connects directly to the NDS parallel bus (the serial SPI chipselect is left unconnected). Unknown how to write to the chip, and unknown if certain regions are write-protected.
DS Cartridges with built-in MicroSD Card Slot
The DS Vision cartridge contains a built-in microSD card slot. Users can download videos from internet (against a few), store the videos on microSD cards, and then view them on the NDS via DS Vision cartridge.
Unknown how the microSD is accessed; via parallel 'ROM' bus and/or via serieal SPI bus; by which commands? Also unknown if the thing contains built-in video decoder hardware, or if videos are decoded on ARM cpus.

DS Cart Cheat Action Replay DS

The first commercial DS cheat code solution, this device was developed by Datel. It supports swapping out cartridges after loading the AR software. For updating, the user may either manually enter codes or use the included proprietary USB cable that comes with the device. The user has been able to manually update codes since firmware version 1.52.
Action Replay DS Codes

      ABCD-NNNNNNNN       Game ID ;ASCII Gamecode [00Ch] and CRC32 across [0..1FFh]
      00000000 XXXXXXXX   manual hook codes (rarely used) (default is auto hook)
      0XXXXXXX YYYYYYYY   word[XXXXXXX+offset] = YYYYYYYY
      1XXXXXXX 0000YYYY   half[XXXXXXX+offset] = YYYY
      2XXXXXXX 000000YY   byte[XXXXXXX+offset] = YY
      3XXXXXXX YYYYYYYY   IF YYYYYYYY > word[XXXXXXX]   ;unsigned    ;\
      4XXXXXXX YYYYYYYY   IF YYYYYYYY < word[XXXXXXX]   ;unsigned    ; for v1.54,
      5XXXXXXX YYYYYYYY   IF YYYYYYYY = word[XXXXXXX]                ; when X=0,
      6XXXXXXX YYYYYYYY   IF YYYYYYYY <> word[XXXXXXX]               ; uses
      7XXXXXXX ZZZZYYYY   IF YYYY > ((not ZZZZ) AND half[XXXXXXX])   ; [offset]
      8XXXXXXX ZZZZYYYY   IF YYYY < ((not ZZZZ) AND half[XXXXXXX])   ; instead of
      9XXXXXXX ZZZZYYYY   IF YYYY = ((not ZZZZ) AND half[XXXXXXX])   ; [XXXXXXX]
      AXXXXXXX ZZZZYYYY   IF YYYY <> ((not ZZZZ) AND half[XXXXXXX])  ;/
      BXXXXXXX 00000000   offset = word[XXXXXXX+offset]
      C0000000 YYYYYYYY   FOR loopcount=0 to YYYYYYYY  ;execute Y+1 times
      C4000000 00000000   offset = address of the C4000000 code           ;v1.54
      C5000000 XXXXYYYY   counter=counter+1, IF (counter AND YYYY) = XXXX ;v1.54
      C6000000 XXXXXXXX   [XXXXXXXX]=offset                               ;v1.54
      D0000000 00000000   ENDIF
      D1000000 00000000   NEXT loopcount
      D2000000 00000000   NEXT loopcount, and then FLUSH everything
      D3000000 XXXXXXXX   offset = XXXXXXXX
      D4000000 XXXXXXXX   datareg = datareg + XXXXXXXX
      D5000000 XXXXXXXX   datareg = XXXXXXXX
      D6000000 XXXXXXXX   word[XXXXXXXX+offset]=datareg, offset=offset+4
      D7000000 XXXXXXXX   half[XXXXXXXX+offset]=datareg, offset=offset+2
      D8000000 XXXXXXXX   byte[XXXXXXXX+offset]=datareg, offset=offset+1
      D9000000 XXXXXXXX   datareg = word[XXXXXXXX+offset]
      DA000000 XXXXXXXX   datareg = half[XXXXXXXX+offset]
      DB000000 XXXXXXXX   datareg = byte[XXXXXXXX+offset] ;bugged on pre-v1.54
      DC000000 XXXXXXXX   offset = offset + XXXXXXXX
      EXXXXXXX YYYYYYYY   Copy YYYYYYYY parameter bytes to [XXXXXXXX+offset...]
      44332211 88776655   parameter bytes 1..8 for above code  (example)
      0000AA99 00000000   parameter bytes 9..10 for above code (padded with 00s)
      FXXXXXXX YYYYYYYY   Copy YYYYYYYY bytes from [offset..] to [XXXXXXX...]

IF/ENDIF can be nested up to 32 times. FOR/NEXT cannot be nested, any FOR statement does forcefully terminate any prior loop. FOR does backup the current IF condidition flags, and NEXT does restore these flags, so ENDIF(s) aren't required inside of the loop. The NEXT+FLUSH command does (after finishing the loop) reset offset=0, datareg=0, and does clear all condition flags, so further ENDIF(s) aren't required after the loop.
Before v1.54, the DB000000 code did accidently set offset=offset+XXXXXXX after execution of the code. For all word/halfword accesses, the address should be aligned accordingly. For the COPY commands, addresses should be aligned by four (all data is copied with ldr/str, except, on odd lengths, the last 1..3 bytes do use ldrb/strb).
offset, datareg, loopcount, and counter are internal registers in the action replay software.
> The condition register is checked, for all code types
> but the D0, D1 and D2 code type
Makes sense.
> and for the C5 code type it's checked AFTER the counter has
> been incremented (so the counter is always incremented
I love that exceptions ;-)
Hook
The hook codes consist of a series of nine 00000000 XXXXXXXX codes, and must be marked as (M) code (for not being confused with normal 0XXXXXXX YYYYYYYY codes). For all nine codes, the left 32bit are actually don't care (but should be zero), the meaning of the right 32bit varies from 1st to 9th code.

      1st: Address used prior to launching game (eg. 23xxxxxh)
      2nd: Address to write the hook at (inside the ARM7 executable)
      3rd: Hook final address (huh?)
      4th: Hook mode selection (0=auto, 1=mode1, 2=mode2)
      5th: Opcode that replaces the hooked one (eg. E51DE004h)
      6th: Address to store important stuff  (default 23FE000h)
      7th: Address to store the code handler (default 23FE074h)
      8th: Address to store the code list    (default 23FE564h)
      9th: Must be 1 (00000001h)

For most games, the AR does automatically hook code on the ARM7. Doing that automatically is nice, but hooking ARM7 means that there is no access to VRAM, TCM and Cache, which <might> cause problems since efficient games <should> store all important data in TCM or Cache (though, in practice, I'd doubt that any existing NDS games are that efficient).
Thanks
To Kenobi and Dualscreenman from Kodewerx for above ARDS cheat info.

DS Cart Cheat Codebreaker DS

This is Pelican's entry into the DS cheat-device industry. It supports swapping out the cartridges, and alternately, also gives the user the option of connecting another gamecard onto it. For updating, the user may either manually enter codes, or use Wifi to connect to the Codebreaker update site (that updating will overwrite all manually entered codes though).
Codebreaker DS Codes

      ---Initialization---
      0000CR16 GAMECODE                    Specify Game ID, use Encrypted codes
      8000CR16 GAMECODE                    Specify Game ID, use Unencrypted codes
      BEEFC0DE XXXXXXXX                    Change Encryption Keys
      A0XXXXXX YYYYYYYY                    Bootup-Hook 1, X=Address, Y=Value
      A8XXXXXX YYYYYYYY                    Bootup-Hook 2, X=Address, Y=Value
      F0XXXXXX TYYYYYYY         Code-Hook 1 (T=Type,Y=CheatEngineAddr,X=HookAddr)
      F8XXXXXX TPPPPPPP         Code-Hook 2 (T=Type,X=CheatEngineHookAddr,P=Params)
      ---General codes---
      00XXXXXX 000000YY                    [X]=YY
      10XXXXXX 0000YYYY                    [X]=YYYY
      20XXXXXX YYYYYYYY                    [X]=YYYYYYYY
      60XXXXXX 000000YY ZZZZZZZZ 00000000  [[X]+Z]=YY
      60XXXXXX 0000YYYY ZZZZZZZZ 10000000  [[X]+Z]=YYYY
      60XXXXXX YYYYYYYY ZZZZZZZZ 20000000  [[X]+Z]=YYYYYYYY
      30XXXXXX 000000YY                    [X]=[X] + YY
      30XXXXXX 0001YYYY                    [X]=[X] + YYYY
      38XXXXXX YYYYYYYY                    [X]=[X] + YYYYYYYY
      70XXXXXX 000000YY                    [X]=[X] OR  YY
      70XXXXXX 001000YY                    [X]=[X] AND YY
      70XXXXXX 002000YY                    [X]=[X] XOR YY
      70XXXXXX 0001YYYY                    [X]=[X] OR  YYYY
      70XXXXXX 0011YYYY                    [X]=[X] AND YYYY
      70XXXXXX 0021YYYY                    [X]=[X] XOR YYYY
      ---Memory fill/copy---
      40XXXXXX 2NUMSTEP 000000YY 000000ZZ  byte[X+(0..NUM-1)*STEP*1]=Y+(0..NUM-1)*Z
      40XXXXXX 1NUMSTEP 0000YYYY 0000ZZZZ  half[X+(0..NUM-1)*STEP*2]=Y+(0..NUM-1)*Z
      40XXXXXX 0NUMSTEP YYYYYYYY ZZZZZZZZ  word[X+(0..NUM-1)*STEP*4]=Y+(0..NUM-1)*Z
      50XXXXXX YYYYYYYY ZZZZZZZZ 00000000  copy Y bytes from [X] to [Z]
      ---Conditional codes (bugged)---
      60XXXXXX 000000YY ZZZZZZZZ 01c100VV  IF [[X]+Z] .. VV   THEN [[X]+Z]=YY
      60XXXXXX 000000YY ZZZZZZZZ 01c0VVVV  IF [[X]+Z] .. VVVV THEN [[X]+Z]=YY
      60XXXXXX 0000YYYY ZZZZZZZZ 11c100VV  IF [[X]+Z] .. VV   THEN [[X]+Z]=YYYY
      60XXXXXX 0000YYYY ZZZZZZZZ 11c0VVVV  IF [[X]+Z] .. VVVV THEN [[X]+Z]=YYYY
      60XXXXXX YYYYYYYY ZZZZZZZZ 21c100VV  IF [[X]+Z] .. VV   THEN [[X]+Z]=YYYYYYYY
      60XXXXXX YYYYYYYY ZZZZZZZZ 21c0VVVV  IF [[X]+Z] .. VVVV THEN [[X]+Z]=YYYYYYYY
      ---Conditional codes (working)---
      D0XXXXXX NNc100YY                    IF [X] .. YY   THEN exec max(1,NN) lines
      D0XXXXXX NNc0YYYY                    IF [X] .. YYYY THEN exec max(1,NN) lines

The condition digits (c=0..7), have the following functions:

      0 IF [mem] =  imm THEN ...              4 IF ([mem] AND imm) =  0   THEN ...
      1 IF [mem] <> imm THEN ...              5 IF ([mem] AND imm) <> 0   THEN ...
      2 IF [mem] <  imm THEN ... (unsigned)   6 IF ([mem] AND imm) =  imm THEN ...
      3 IF [mem] >  imm THEN ... (unsigned)   7 IF ([mem] AND imm) <> imm THEN ...

Notes

      GAMECODE  Cartridge Header[00Ch] (32bit in reversed byte-order)
      CR16      Cartridge Header[15Eh] (16bit in normal byte-order)
      XXXXXX    27bit addr (actually 7 digits, XXXXXXX, overlaps 5bit code number)

The "bugged" conditional codes (60XXXXXX) are accidently skipping NN lines when the condition is false, where NN is taken from the upper 8bit of the code's last 32bit values (ie. exactly as for the D0XXXXXX codes). For byte-writes, that would be NN=01h, which can be eventually dealt with, although there may be compatibility problems which future versions that might fix that bug. For halfword/word writes, NN would be 11h or 21h, so that codes are about totally unusable.
Codebreaker DS / Encrypted Codes
The overall "address value" decryption works like so:

      for i=4Fh to 00h
        y=77628ECFh
        if i>13h then y=59E5DC8Ah
        if i>27h then y=054A7818h
        if i>3Bh then y=B1BF0855h
        address = (Key0-value) xor address
        value   = value - Key1 - (address ror 1Bh)
        address = (address xor (value + y)) ror 13h
        if (i>13h) then
          if (i<=27h) or (i>3Bh) then x=Key2 xor Key1 xor Key0
          else x=((Key2 xor Key1) and Key0) xor (Key1 and Key2)
          value=value xor (x+y+address)
          x = Secure[((i*4+00h) and FCh)+000h]
          x = Secure[((i*4+34h) and FCh)+100h] xor x
          x = Secure[((i*4+20h) and FCh)+200h] xor x
          x = Secure[((i*4+08h) and FCh)+300h] xor x
          address = address - (x ror 19h)
      next i

Upon startup, the initial key settings are:

      Secure[0..7FFh] = Copy of the ENCRYPTED 1st 2Kbytes of the game's Secure Area
      Key0 = 0C2EAB3Eh, Key1 = E2AE295Dh, Key2 = E1ACC3FFh, Key3 = 70D3AF46h
      scramble_keys

Upon BEEFC0DE XXXXXXXX, the keys get changed like so:

      Key0 = Key0 + (XXXXXXXX ror 1Dh)
      Key1 = Key1 - (XXXXXXXX ror 05h)
      Key2 = Key2 xor (Key3 xor Key0)
      Key3 = Key3 xor (Key2  -  Key1)
      scramble_keys

The above scramble_keys function works like so:

      for i=0 to FFh
        y = byte(xlat_table[i])
        Secure[i*4+000h] = (Secure[i*4+000h] xor Secure[y*4]) + Secure[y*4+100h]
        Secure[i*4+400h] = (Secure[i*4+400h] xor Secure[y*4]) - Secure[y*4+200h]
      next i
      for i=0 to 63h
        Key0 = Key0 xor (Secure[i*4] + Secure[i*4+190h])
        Key1 = Key1 xor (Secure[i*4] + Secure[i*4+320h])
        Key2 = Key2 xor (Secure[i*4] + Secure[i*4+4B0h])
        Key3 = Key3 xor (Secure[i*4] + Secure[i*4+640h])
      next i
      Key0 = Key0  -  Secure[7D0h]
      Key1 = Key1 xor Secure[7E0h]
      Key2 = Key2  +  Secure[7F0h]
      Key3 = Key3 xor Secure[7D0h] xor Secure[7F0h]

the xlat_table consists of 256 fixed 8bit values:

      34h,59h,00h,32h,7Bh,D3h,32h,C9h,9Bh,77h,75h,44h,E0h,73h,46h,06h
      0Bh,88h,B3h,3Eh,ACh,F2h,BAh,FBh,2Bh,56h,FEh,7Ah,90h,F7h,8Dh,BCh
      8Bh,86h,9Ch,89h,00h,19h,CDh,4Ch,54h,30h,01h,93h,30h,01h,FCh,36h
      4Dh,9Fh,FDh,D7h,32h,94h,AEh,BCh,2Bh,61h,DFh,B3h,44h,EAh,8Bh,A3h
      2Bh,53h,33h,54h,42h,27h,21h,DFh,A9h,DDh,C0h,35h,58h,EFh,8Bh,33h
      B4h,D3h,1Bh,C7h,93h,AEh,32h,30h,F1h,CDh,A8h,8Ah,47h,8Ch,70h,0Ch
      17h,4Eh,0Eh,A2h,85h,0Dh,6Eh,37h,4Ch,39h,1Fh,44h,98h,26h,D8h,A1h
      B6h,54h,F3h,AFh,98h,83h,74h,0Eh,13h,6Eh,F4h,F7h,86h,80h,ECh,8Eh
      EEh,4Ah,05h,A1h,F1h,EAh,B4h,D6h,B8h,65h,8Ah,39h,B3h,59h,11h,20h
      B6h,BBh,4Dh,88h,68h,24h,12h,9Bh,59h,38h,06h,FAh,15h,1Dh,40h,F0h
      01h,77h,57h,F5h,5Dh,76h,E5h,F1h,51h,7Dh,B4h,FAh,7Eh,D6h,32h,4Fh
      0Eh,C8h,61h,C1h,EEh,FBh,2Ah,FCh,ABh,EAh,97h,D5h,5Dh,E8h,FAh,2Ch
      06h,CCh,86h,D2h,8Ch,10h,D7h,4Ah,CEh,8Fh,EBh,03h,16h,ADh,84h,98h
      F5h,88h,2Ah,18h,ACh,7Fh,F6h,94h,FBh,3Fh,00h,B6h,32h,A2h,ABh,28h
      64h,5Ch,0Fh,C6h,23h,12h,0Ch,D2h,BAh,4Dh,A3h,F2h,C9h,86h,31h,57h
      0Eh,F8h,ECh,E1h,A0h,9Ah,3Ch,65h,17h,18h,A0h,81h,D0h,DBh,D5h,AEh

all used operations are unsigned 32bit integer.
Thanks
To Kenobi and Dualscreenman from Kodewerx for above CBDS cheat info.

DS Cart DLDI Driver

DLDI (Dynamically Linked Device Interface for libfat) is a popular yet undocumented flashcart driver for homebrew NDS software dating back to 2006. Below was reverse-engineered 11/2018.
file.dldi --> driver file (can be small like 1.5Kbyte, or max 32Kbyte)
file.nds --> ROM image (must contain 32Kbyte space with DLDI ID for patching)
Driver patch file standard header

      00h 4  DLDI ID       (EDh,A5h,8Dh,BFh) (aka BF8DA5EDh)  ;\patching tools will
      04h 8  DLDI String   (20h,"Chishm",00h)                 ; refuse any other
      0Ch 1  DLDI Version  (01h in .dldi, don't care in .nds) ;/values
      0Dh 1  Size of .dldi+BSS (rounded up to 1 SHL N bytes) (max 0Fh=32Kbytes)
      0Eh 1  Sections to fix/destroy (see FIX_xxx)
      0Fh 1  Space in .nds file (1 SHL N) (0Eh..0Fh in .nds, can be 0 in .dldi)
      10h 48 ASCII Full Driver Name (max 47 chars, plus zero padding)
      40h 4  Address of ALL start (text) ;-base address (BF800000h in .dldi)
      44h 4  Address of ALL end   (data) ;-for highly-unstable FIX_ALL addr.adjusts
      48h 4  Address of GLUE start       ;\for semi-stable FIX_GLUE addr.adjusts
      4Ch 4  Address of GLUE end         ;/  ("Interworking glue" for ARM-vs-THUMB)
      50h 4  Address of GOT start        ;\for semi-stable FIX_GOT addr.adjusts
      54h 4  Address of GOT end          ;/  ("Global Offset Table")
      58h 4  Address of BSS start        ;\for zerofilling "BSS" via FIX_BSS
      5Ch 4  Address of BSS end          ;/  ("Block Started by Symbol")
      60h 4  ASCII Short Driver/Device Name (4 chars, eg. "MYHW" for MyHardware)
      64h 4  Flags 2 (see FEATURE_xxx) (usually 13h=GbaSlot, or 23h=NdsSlot)
      68h 4  Address of Function startup() ;<-- must be at offset +80h !! ;\
      6Ch 4  Address of Function isInserted() ;out: 0=no/fail, 1=yes/okay ; all
      70h 4  Address of Function readSectors(sector,numSectors,buf)       ; return
      74h 4  Address of Function writeSectors(sector,numSectors,buf)      ; 0=fail,
      78h 4  Address of Function clearStatus()                            ; 1=okay
      7Ch 4  Address of Function shutdown()                               ;/
      80h .. Driver Code (can/must begin with "startup()")            ;\max 7F80h
      ..  .. Glue section (usually a small snippet within above code) ; bytes (when
      ..  .. GOT section (usually after above code) (pointer table)   ; having 32K
      ..  .. BSS section (usually at end, may exceed .dldi filesize)  ; allocated)
      ..  .. Optional two garbage NOPs at end of default.dldi         ;/

hdr[0Eh] - Sections to fix/destroy (FIX_xxx):

      0    FIX_ALL   ;-installer uses highly-unstable guessing in whole dldi file
      1    FIX_GLUE  ;-installer uses semi-stable address guessing in GLUE area
      2    FIX_GOT   ;-installer uses semi-stable address guessing in GOT area
      3    FIX_BSS   ;-installer will zerofill BSS area
      4-7  Reserved (0)

hdr[64h] - Flags 2 (FEATURE_xxx) (usually 13h=GbaSlot, or 23h=NdsSlot):

      0    FEATURE_MEDIUM_CANREAD          00000001h (usually set)
      1    FEATURE_MEDIUM_CANWRITE         00000002h (a few carts can't write)
      2-3  Reserved (0)
      4    FEATURE_SLOT_GBA                00000010h (need EXMEMCNT bit7 adjusted)
      5    FEATURE_SLOT_NDS                00000020h (need EXMEMCNT bit11 adjusted)
      6-31 Reserved (0)

Note: The allocated driver size in hdr[0Fh] was 0Fh=32Kbytes between 2006 and 2016, however, libnds has changed that to 0Eh=16Kbytes in January 2017 (maybe intending to free more RAM, especially when using ARM7 WRAM).
However, there's at least one driver exceeding 16K (rpg_nand.dldi in AKAIO package; the driver disguises itself as 8K driver in hdr[0Dh], but its BSS area actually needs ways MORE than 16K).
Required entries in .nds file
Officially, dldi could be at any 4-byte aligned location, however, for faster lookup, better use this locations:

      dldi area should be located at a 40h-byte aligned address in ROM image.
      dldi area should be located in ARM9 (or ARM7) bootcode area.

An "empty" driver needs to contain:

      dldi[00h..0Bh] must contain DLDI ID word/string
      dldi[0Fh]      must contain allocated size (0Eh=16Kbyte or 0Fh=32Kbyte)
      dldi[40h..43h] must contain RAM base address of DLDI block
      and other entries should contain valid dummy strings and dummy functions.

An installed driver should contain a copy of the .dldi file, with addresses adjusted to RAM locations, and BSS area zerofilled (if FIX_BSS was set)

      dldi[0Fh] must be kept as in the old .nds file (not as in .dldi file)

Some installers might try to detect homebrew by looking at nds carthdr for deciding whether or not to try to install dldi (unknown if/which ones are doing such things and looking at which carthdr entries).
Functions
startup, isInserted, clearStatus, shutdown can be dummy functions that do nothing (other than returning r0=1=okay).
Alternately startup/shutdown can initialize or power down the hardware, clearStatus is meant to be some sort of soft reset, and isInserted is allowing to test if the SD card is inserted & working.
read/write sectors are reading/writing one or more sectors. Sector size is 200h bytes, sector numbers is 0=First 200h bytes, 1=Next 200h bytes, and so on.
buf should be usually 4-byte aligned, however, some drivers do also support unaligned buffers using slower transfer code (better implement that when making .dldi drivers, but better don't rely on it being supported when making .nds files).
The driver functions can support SD and SDHC (or the flashcart manufacturer might release driver updates if SDHC wasn't supported).
Higher level FAT functions must be contained in the .nds file (so a driver update won't help if the .nds file lacks FAT32) (and ExFAT most unlikely to be supported).
Functions should be ARM7 compatible, ie. don't use BLX or POP r15 for mode switching, so the driver can be used on both ARM9 and ARM7 (or even on GBA).
SLOT_GBA/NDS
SLOT_GBA/NDS seem to relate to GBA and NDS slots, the driver can probably have only one of the SLOT bits set (the functions don't allow to select which slot to use).
Purpose is unclear to me, maybe just telling the .nds file that the flashcart is in the given slot (and thereby shouldn't expect other hardware in that slot). Or maybe telling telling the installer which hardware the driver is supposed for.
FIX_xxx does maybe relate to address adjustments made by the dldi installer. Unknown if/how that's working.
DS Cart DLDI Driver - Guessed Address-Adjustments
Some DLDI flashcarts support extra features like Rumble. However, that extra hardware is accessed via direct I/O, not via DLDI driver. Unknown which I/O ports are used for that stuff - probably something compatible with official GBA/NDS rumble cart(s).

DS Cart DLDI Driver - Guessed Address-Adjustments

The DLDI installer uses some guessing method for address-adjustments (the FIX_xxx flags are supposed to patch addresses, but not opcodes or other data).
Unaligned-Word patching and over-shooting bug
The central mistake in the official DLDI installer is that it is patching all words at [start..end-1], using 1-byte address increments instead of 4-byte increments. This includes patching words at non-word aligned locations, or patching words whose lower bytes were already patched, and over-shooting to words at [end-1..end+2].
ddmem Base BF800000h
Most or all .dldi files are using ddmem base BF800000h (defined in dldi.ld). That value was chosen because it won't conflict with opcodes (as NDS BIOS doesn't use SWI function 80h, BF80xxxxh would be an invalid SWI function in ARM; and BF80h would be an invalid opcode in THUMB).
So far, this would have worked well, but it doesn't work with unaligned-word patching bug (eg. THUMB opcodes 8000h,BF00h, or ARM opcodes xxBF80xxh or the like). And, even if it would have worked for opcodes - it might still fail for data values.
FIX_GOT
GOT does usually contain BF80xxxxh address pointers (plus some 00000000h words). The guessing works quite stable (the maximum for 32K files is xxxxh=7FFFh, so there's no risk to encounter xxxx=BF80h) (one could encounter xxxxh=xxBFh, but the previously patched word is usually in RAM area, eg. 02xxxxxxh, so this would form BF02h, without risk to be seen as BF80h).
BUG: The GOT table is usually located at the end of the .dldi file, meaning that the over-shooting bug will see three uninitialized bytes at [got_end+0..2], and may go amok if they are BF80xxh or xxBF80h. The value of those bytes depends on left-over from previously installed .dldi driver(s) and on the ddmem base used in the .nds file, so the bug may take place randomly depending on several factors.
FIX_GLUE
GLUE does usually contain a handful of opcodes and .pool values for switching between ARM and THUMB code. The intention is to patch the addresses in the .pool, and to leave the opcodes intact. This can be potentially stable, assuming that the used opcodes in the GLUE (and the next three bytes after glue_end) usually won't contain BF80h).
FIX_ALL
This is the mother of all bugs. Fortunately there aren't any .dldi drivers with FIX_ALL flag - and one should never make drivers that do use it.
ALL is covering the whole dldi space, including the 80h-byte DLDI header, the code area, including GLUE area, and GOT area, and probably also the yet uninitialized BSS area, and the next three bytes after end_all.
Patching the whole code area means an increased risk to hit opcodes or data values that contain BF80h. The over-shooting bug may even destroy the next three bytes after the 32Kbyte area.
Patching the DLDI header could destroy the header itself, the header in the .dldi file usually won't contain BF80h at unintended locations, however, the pointers in that header are adjusted before applying FIX_ALL, for example, RAM base 0200BF00h (in .nds file) combined with a function at BF800080h (in .dldi file) would result in 0200BF80h. The nasty thing is that the problem won't occur with other RAM base values (in other .nds files).
Avoiding the bugs
When making .dldi drivers: Never use FIX_ALL. And preferably avoid FIX_GOT and FIX_GLUE as well (ARM CPU can do relative jumps and relative addressing, eg. via ADR and ADRL pseudo opcodes, so there's no point in needing address adjustments). Or otherwise append padding after GOT area, and try to avoid using opcodes/data with BF80h in/after GLUE area.
When making dldi installers: Best patch only word-aligned words (ARM CPU can't access unaligned data, so there's little chance that DLDI drivers would ever contain unaligned words). Or, when maintaining unaligned patching: At the very least skip the 80h-byte header on FIX_ALL, and after patching a word at other locations, skip the next three bytes, and don't do the over-shooting at end.
When making .nds files: There isn't too much that could be done here. One could set ddmem to 64Kbyte aligned addresses (so functions won't end up at xxxxBF80h). Or one could even set ddmem to BF800000h (so patching will leave everything unchanged & intact - so one could then do the address adjustments manually, and hopefully more reliable than other DLDI installers).

DS Encryption by Gamecode/Idcode (KEY1)

KEY1 - Gamecode / Idcode Encryption
The KEY1 encryption relies only on the gamecode (or firmware idcode), it does not contain any random components. The fact that KEY1 encrypted commands appear random is just because the <unencrypted> commands contain random values, so the encryption result looks random.
KEY1 encryption is used for KEY1 encrypted gamecart commands (ie. for loading the secure area). It is also used for resolving the extra decryption of the first 2K of the secure area, and for firmware decryption, and to decode some encrypted values in gamecart/firmware header.
Initial Encryption Values
Below formulas can be used only with a copy of the 1048h-byte key tables from NDS/DSi BIOS. The values can be found at:

      NDS.ARM7 ROM: 00000030h..00001077h (values 99 D5 20 5F ..) Blowfish/NDS-mode
      DSi.ARM9 ROM: FFFF99A0h..FFFFA9E7h (values 99 D5 20 5F ..) ""
      DSi.TCM Copy: 01FFC894h..01FFD8DBh (values 99 D5 20 5F ..) ""
      DSi.ARM7 ROM: 0000C6D0h..0000D717h (values 59 AA 56 8E ..) Blowfish/DSi-mode
      DSi.RAM Copy: 03FFC654h..03FFD69Bh (values 59 AA 56 8E ..) ""
      DSi.Debug:    (stored in launcher) (values 69 63 52 05 ..) Blowfish/DSi-debug

The DSi ROM sections are disabled after booting, but the RAM/TCM copies can be dumped (eg. with some complex main memory hardware mods, or via unlaunch exploit). The DSi.Debug key is stored in launcher, and it's used when SCFG_OP is nonzero (as so on debugging on hardware).
encrypt_64bit(ptr) / decrypt_64bit(ptr)

      Y=[ptr+0]
      X=[ptr+4]
      FOR I=0 TO 0Fh (encrypt), or FOR I=11h TO 02h (decrypt)
        Z=[keybuf+I*4] XOR X
        X=[keybuf+048h+((Z SHR 24) AND FFh)*4]
        X=[keybuf+448h+((Z SHR 16) AND FFh)*4] + X
        X=[keybuf+848h+((Z SHR  8) AND FFh)*4] XOR X
        X=[keybuf+C48h+((Z SHR  0) AND FFh)*4] + X
        X=Y XOR X
        Y=Z
      NEXT I
      [ptr+0]=X XOR [keybuf+40h] (encrypt), or [ptr+0]=X XOR [keybuf+4h] (decrypt)
      [ptr+4]=Y XOR [keybuf+44h] (encrypt), or [ptr+4]=Y XOR [keybuf+0h] (decrypt)

apply_keycode(modulo)

      encrypt_64bit(keycode+4)
      encrypt_64bit(keycode+0)
      [scratch]=0000000000000000h   ;S=0 (64bit)
      FOR I=0 TO 44h STEP 4         ;xor with reversed byte-order (bswap)
        [keybuf+I]=[keybuf+I] XOR bswap_32bit([keycode+(I MOD modulo)])
      NEXT I
      FOR I=0 TO 1040h STEP 8
        encrypt_64bit(scratch)      ;encrypt S (64bit) by keybuf
        [keybuf+I+0]=[scratch+4]    ;write S to keybuf (first upper 32bit)
        [keybuf+I+4]=[scratch+0]    ;write S to keybuf (then lower 32bit)
      NEXT I

init_keycode(idcode,level,modulo,key)

      if key=nds then copy [nds_arm7bios+0030h..1077h] to [keybuf+0..1047h]
      if key=dsi then copy [dsi_arm7bios+C6D0h..D717h] to [keybuf+0..1047h]
      [keycode+0]=[idcode]
      [keycode+4]=[idcode]/2
      [keycode+8]=[idcode]*2
      IF level>=1 THEN apply_keycode(modulo) ;first apply (always)
      IF level>=2 THEN apply_keycode(modulo) ;second apply (optional)
      [keycode+4]=[keycode+4]*2
      [keycode+8]=[keycode+8]/2
      IF level>=3 THEN apply_keycode(modulo) ;third apply (optional)

firmware_decryption

      init_keycode(firmware_header+08h,1,0Ch,nds) ;idcode (usually "MACP"), level 1
      decrypt_64bit(firmware_header+18h)          ;rominfo
      init_keycode(firmware_header+08h,2,0Ch,nds) ;idcode (usually "MACP"), level 2
      decrypt ARM9 and ARM7 bootcode by decrypt_64bit (each 8 bytes)
      decompress ARM9 and ARM7 bootcode by LZ77 function (swi)
      calc CRC16 on decrypted/decompressed ARM9 bootcode followed by ARM7 bootcode

Note: The sizes of the compressed/encrypted bootcode areas are unknown (until they are fully decompressed), one way to solve that problem is to decrypt the next 8 bytes each time when the decompression function requires more data.
gamecart_decryption

      init_keycode(cart_header+0Ch,1,08h,nds)   ;gamecode, level 1, modulo 8
      decrypt_64bit(cart_header+78h)            ;rominfo (secure area disable)
      init_keycode(cart_header+0Ch,2,08h,nds)   ;gamecode, level 2, modulo 8
      encrypt_64bit all NDS KEY1 commands (1st command byte in MSB of 64bit value)
      after loading the secure_area, calculate secure_area crc, then
      decrypt_64bit(secure_area+0)              ;first 8 bytes of secure area
      init_keycode(cart_header+0Ch,3,08h,nds)   ;gamecode, level 3, modulo 8
      decrypt_64bit(secure_area+0..7F8h)        ;each 8 bytes in first 2K of secure
      init_keycode(cart_header+0Ch,1,08h,dsi)   ;gamecode, level 1, modulo 8
      encrypt_64bit all DSi KEY1 commands (1st command byte in MSB of 64bit value)

After secure area decryption, the ID field in the first 8 bytes should be "encryObj", if it matches then first 8 bytes are filled with E7FFDEFFh, otherwise the whole 2K are filled by that value.
Gamecart Command Register
Observe that the byte-order of the command register [40001A8h] is reversed. The way how the CPU stores 64bit data in memory (and the way how the "encrypt_64bit" function for KEY1-encrypted commands expects data in memory) is LSB at [addr+0] and MSB at [addr+7]. This value is to be transferred MSB first. However, the DS hardware transfers [40001A8h+0] first, and [40001A8h+7] last. So, the byte order must be reversed when copying the value from memory to the command register.
Note
The KEY1 encryption is based on Bruce Schneier's "Blowfish Encryption Algorithm".

DS Encryption by Random Seed (KEY2)

KEY2 39bit Seed Values
The pre-initialization settings at cartridge-side (after reset) are:

      Seed0 = 58C56DE0E8h
      Seed1 = 5C879B9B05h

The post-initialization settings (after sending command 4llllmmmnnnkkkkkh to the cartridge, and after writing the Seed values to Port 40001Bxh) are:

      Seed0 = (mmmnnn SHL 15)+6000h+Seedbyte
      Seed1 = 5C879B9B05h

The seedbyte is selected by Cartridge Header [013h].Bit0-2, this index value should be usually in range 0..5, however, possible values for index 0..7 are: E8h,4Dh,5Ah,B1h,17h,8Fh,99h,D5h.
The 24bit random value (mmmnnn) is derived from the real time clock setting, and also scattered by KEY1 encryption, anyways, it's just random and doesn't really matter where it comes from.
KEY2 Encryption
Relies on two 39bit registers (x and y), which are initialized as such:

      x = reversed_bit_order(seed0)  ;ie. LSB(bit0) exchanged with MSB(bit38), etc.
      y = reversed_bit_order(seed1)

During transfer, x, y, and transferred data are modified as such:

      x = (((x shr 5)xor(x shr 17)xor(x shr 18)xor(x shr 31)) and 0FFh)+(x shl 8)
      y = (((y shr 5)xor(y shr 23)xor(y shr 18)xor(y shr 31)) and 0FFh)+(y shl 8)
      data = (data xor x xor y) and 0FFh

DS Firmware Serial Flash Memory

ST Microelectronics SPI Bus Compatible Serial FLASH Memory

     Chips used as wifi-flash:
      ID 20h,40h,12h - ST M45PE20 - 256 KBytes (Nintendo DS) (in my old DS)
      ID 20h,50h,12h - ST M35PE20 - 256 KBytes (Nintendo DS) (in my DS-Lite)
      ID 20h,80h,13h - ST M25PE40 - 512 KBytes (iQue DS, with chinese charset)
      ID 20h,40h,11h - ST 45PE10V6 - 128 Kbytes (Nintendo DSi) (in my DSi)
      ID 20h,58h,0Ch?- 5A32        - 4 Kbytes (Nintendo DSi, newer models)
      ID ?           - 26FV032T    - (Nintendo DSi, J27H020) (this has big package)
      ID ?           - 5K32        - (3DS?)
      ID 62h,62h,0Ch - 32B, 3XH    - 4 Kbytes (New3DS)
     Other similar chips (used in game cartridges):
      ID 20h,40h,13h - ST 45PE40V6 - 512 KBytes (DS Zelda, NTR-AZEP-0)
      ID 20h,40h,14h - ST 45PE80V6 - 1024 Kbytes (eg. Spirit Tracks, NTR-BKIP)
     +ID 62h,11h,00h - Sanyo ?          - 512 Kbytes (P-Letter Diamond, ADAE)
      ID 62h,16h,00h - Sanyo LE25FW203T - 256 KBytes (Mariokart backup)
     +ID 62h,26h,11h - Sanyo ?          - ? Kbytes (3DS: CTR-P-AXXJ)
     +ID 62h,26h,13h - Sanyo ?          - ? Kbytes (3DS: CTR-P-APDJ)
      ID C2h,22h,11h - Macronix MX25L1021E? 128 Kbytes (eg. 3DS Starfox)
      ID C2h,22h,13h - Macronix ...? 512 Kbytes (eg. 3DS Kid Icarus, 3DS Sims 3)
      ID C2h,20h,17h - Macronix MX25L6445EZNI-10G 8192 Kbytes (DSi Art Academy)
      ID 01h,F0h,00h - Garbage/Infrared on SPI-bus? (eg. P-Letter White)
      ID 03h,F8h,00h - Garbage/Infrared on SPI-bus? (eg. P-Letter White 2)

FLASH has more than 100,000 Write Cycles, more than 20 Year Data Retention
The Firmware Flash Memory is accessed via SPI bus,
DS Serial Peripheral Interface Bus (SPI)
Instruction Codes

      06h  WREN Write Enable (No Parameters)
      04h  WRDI Write Disable (No Parameters)
      9Fh  RDID Read JEDEC Identification (Read 1..3 ID Bytes)
                 (Manufacturer, Device Type, Capacity)
      05h  RDSR Read Status Register (Read Status Register, endless repeated)
                 Bit7-2  Not used (zero)
                 Bit1    WEL Write Enable Latch             (0=No, 1=Enable)
                 Bit0    WIP Write/Program/Erase in Progess (0=No, 1=Busy)
      03h  READ Read Data Bytes (Write 3-Byte-Address, read endless data stream)
      0Bh  FAST Read Data Bytes at Higher Speed (Write 3-Byte-Address, write 1
                 dummy-byte, read endless data stream) (max 25Mbit/s)
      0Ah  PW   Page Write (Write 3-Byte-Address, write 1..256 data bytes)
                 (changing bits to 0 or 1) (reads unchanged data, erases the page,
                 then writes new & unchanged data) (11ms typ, 25ms max)
      02h  PP   Page Program (Write 3-Byte-Address, write 1..256 data bytes)
                 (changing bits from 1 to 0) (1.2ms typ, 5ms max)
      DBh  PE   Page Erase 100h bytes (Write 3-Byte-Address) (10ms typ, 20ms max)
      D8h  SE   Sector Erase 10000h bytes (Write 3-Byte-Address) (1s typ, 5s max)
      B9h  DP   Deep Power-down (No Parameters) (consumption 1uA typ, 10uA max)
                 (3us) (ignores all further instructions, except RDP)
      ABh  RDP  Release from Deep Power-down (No Parameters) (30us)

Write/Program may not cross page-boundaries. Write/Program/Erase are rejected during first 1..10ms after power up. The WEL bit is automatically cleared on Power-Up, on /Reset, and on completion of WRDI/PW/PP/PE/SE instructions. WEL is set by WREN instruction (which must be issued before any write/program/erase instructions). Don't know how RDSR behaves when trying to write to the write-protected region?
Communication Protocol

      Set Chip Select LOW to invoke the command
      Transmit the instruction byte
      Transmit any parameter bytes
      Transmit/receive any data bytes
      Set Chip Select HIGH to finish the command

All bytes (and 3-byte addresses) transferred most significant bit/byte first.
DSi "5A32" chip (32Kit aka 4Kbyte)
Early DSi DWM-W015 boards did have 128Kbyte FLASH, but later boards have custum 4Kbyte FLASH chips (these 4K chips are found on later DSi DWM-W015 boards, and DSi DWM-W024 boards, and 3DS DWM-W028 boards). The chips are having a 24bit address bus (needed for NDS compatibility), and, a weird non-writeable gap within a 128Kbyte memory are:

      000000h..0002FFh  Writeable only if /WP=HIGH (otherwise writes are ignored)
      000300h..01F2FFh  Not writeable (FFh-filled, writes are ignored)
      01F300h..01FFFFh  Writeable
      020000h and up    Mirrors of 0..01FFFFh (same read/write-ability as above)

There are several part numbers: "5A32" (DSi), "5K32" (3DS), "32B, 3XH" (3DS), and "26FV032T" (DSi), that chips are probably all the same size & functionally same; most of those 4Kbyte chips have tiny packages (except "26FV032T" which comes in classic large package).
Pin-Outs (Large Package, in NDS, and early DSi boards)

      1   D    Serial Data In (latched at rising clock edge)          _________
      2   C    Serial Clock (max 25MHz)                             /|o        |
      3   /RES Reset                                            1 -| |         |- 8
      4   /S   Chip Select (instructions start at falling edge) 2 -| |         |- 7
      5   /W   Write Protect (makes first 256 pages read-only)  3 -| |_________|- 6
      6   VCC  Supply (2.7V..3.6V typ) (4V max) (DS:VDD3.3)     4 -|/          |- 5
      7   VSS  Ground                                              |___________|
      8   Q    Serial Data Out (changes at falling clock edge)

Pin-Outs (Tiny Package, in newer DSi boards, and 3DS)

      1   /S   Chip Select (instructions start at falling edge)     ___________
      2   Q    Serial Data Out (changes at falling clock edge)  1 -| o         |- 8
      3   /W   Write Protect (makes first pages read-only)      2 -|           |- 7
      4   VSS  Ground                                           3 -|           |- 6
      5   D    Serial Data In (latched at rising clock edge)    4 -|___________|- 5
      6   C    Serial Clock
      7   /RES Reset
      8   VCC  Supply (2.7V..3.6V typ) (DSi: VDD33)

DS Firmware Header

Firmware Memory Map

      00000h-00029h  Firmware Header
      0002Ah-001FFh  Wifi Settings
      00200h-3F9FFh  Firmware Code/Data                       ;-NDS only (not DSi)
      00200h-002FEh  00h-filled                               ;\
      002FFh         80h                                      ;
      00300h-1F2FFh  FFh-filled (not write-able on 4K chips)  ; DSi only (not NDS)
      1F300h-1F3FEh  FFh-filled (write-able)                  ;
      1F3FFh         Whatever Debug/Bootflags                 ;
      1F400h-1F5FFh  Wifi Access Point 4  ;\with WPA/WPA2     ;
      1F600h-1F7FFh  Wifi Access Point 5  ; support           ;
      1F800h-1F9FFh  Wifi Access Point 6  ;/                  ;/
      3FA00h-3FAFFh  Wifi Access Point 1  ;\
      3FB00h-3FBFFh  Wifi Access Point 2  ; Open/WEP only
      3FC00h-3FCFFh  Wifi Access Point 3  ;/
      3FD00h-3FDFFh  Not used
      3FE00h-3FEFFh  User Settings Area 1
      3FF00h-3FFFFh  User Settings Area 2

On iQue DS (with 512K flash memory), user settings are moved to 7FE00h and up, and, there seems to be some unknown stuff at 200h..27Fh.
Firmware Header (00000h-001FFh)

      Addr Size Expl.
      000h 2    part3 romaddr/8 (arm9 gui code) (LZ/huffman compression)
      002h 2    part4 romaddr/8 (arm7 wifi code) (LZ/huffman compression)
      004h 2    part3/4 CRC16 arm9/7 gui/wifi code
      006h 2    part1/2 CRC16 arm9/7 boot code
      008h 4    firmware identifier (usually nintendo "MAC",nn) (or nocash "XBOO")
                the 4th byte (nn) occassionally changes in different versions
      00Ch 2    part1 arm9 boot code romaddr/2^(2+shift1) (LZSS compressed)
      00Eh 2    part1 arm9 boot code 2800000h-ramaddr/2^(2+shift2)
      010h 2    part2 arm7 boot code romaddr/2^(2+shift3) (LZSS compressed)
      012h 2    part2 arm7 boot code 3810000h-ramaddr/2^(2+shift4)
      014h 2    shift amounts, bit0-2=shift1, bit3-5=shift2, bit6-8=shift3,
                bit9-11=shift4, bit12-15=firmware_chipsize/128K
      016h 2    part5 data/gfx romaddr/8 (LZ/huffman compression)
      018h 8    Optional KEY1-encrypted "enPngOFF"=Cartridge KEY2 Disable
                (feature isn't used in any consoles, instead contains timestamp)
      018h 5    Firmware version built timestamp (BCD minute,hour,day,month,year)
      01Dh 1    Console type
                  FFh=Nintendo DS
                  20h=Nintendo DS-lite
                  57h=Nintendo DSi (also iQueDSi)
                  43h=iQueDS
                  63h=iQueDS-lite
                The entry was unused (FFh) in older NDS, ie. replace FFh by 00h)
                  Bit0   seems to be DSi/iQue related
                  Bit1   seems to be DSi/iQue related
                  Bit2   seems to be DSi related
                  Bit3   zero
                  Bit4   seems to be DSi related
                  Bit5   seems to be DS-Lite related
                  Bit6   indicates presence of "extended" user settings (DSi/iQue)
                  Bit7   zero
      01Eh 2    Unused (FFh-filled)
      020h 2    User Settings Offset (div8) (usually last 200h flash bytes)
      022h 2    Unknown (7EC0h or 0B51h)
      024h 2    Unknown (7E40h or 0DB3h)
      026h 2    part5 CRC16 data/gfx
      028h 2    unused (FFh-filled)
      02Ah-1FFh Wifi Calibration Data (see next chapter)

DSi

      000h 1Dh   Zerofilled (bootcode is in new eMMC chip, not on old FLASH chip)
      01Dh 6     Same as on DS (header: Console Type and User Settings Offset)
      022h 6     Zerofilled (bootcode is in new eMMC chip, not on old FLASH chip)
      028h..1FCh Same as on DS (wifi calibration)
      1FDh 1     Wifi Board (01h=DWM-W015, 02h=W024, 03h=W028)   ;\this was
      1FEh 1     Wifi Flash (20h=With access point 4/5/6)        ; FFh-filled
      1FFh 1     Same as on DS (FFh)                             ;/on DS
      200h FFh   Zerofilled                                      ;\
      2FFh 1     Unknown (80h)                                   ; this was
      300h   1F000h FFh's (not write-able on 4K chips)           ; bootcode
      1F300h FFh    FFh's (write-able) ;twl-debugger: 00h's      ; on DS
      1F3FFh 1      FFh                ;twl-debugger: 40h        ;/

The bytes [000h..027h] cannot be changed on DSi because they are part of the RSA signature in DSi's Boot Info Block (at eMMC offset 200h..3FFh).

DS Firmware Wifi Calibration Data

Wifi Calibration/Settings (located directly after Firmware Header)

      Addr Size Expl.
      000h-029h Firmware Header (see previous chapter)
      02Ah 2    CRC16 (with initial value 0) of [2Ch..2Ch+config_length-1]
      02Ch 2    config_length (usually 0138h, ie. entries 2Ch..163h)
      02Eh 1    Unused        (00h)
      02Fh 1    Version (0=v1..v4, 3=v5, 5=v6..v7,6=W006,15=W015,24=W024,34=N3DS)
      030h 6    Unused        (00h-filled) (DS-Lite and DSi: FF,FF,FF,FF,FF,00)
      036h 6    48bit MAC address (v1-v5: 0009BFxxxxxx, v6-v7: 001656xxxxxx)
      03Ch 2    list of enabled channels ANDed with 7FFE (Bit1..14 = Channel 1..14)
                (usually 3FFEh, ie. only channel 1..13 enabled)
      03Eh 2    Whatever Flags (usually FFFFh)
      040h 1    RF Chip Type (NDS: usually 02h) (DS-Lite and DSi/3DS: usually 03h)
      041h 1    RF Bits per entry at 0CEh (usually 18h=24bit=3byte) (Bit7=?)
      042h 1    RF Number of entries at 0CEh (usually 0Ch)
      043h 1    Unknown (usually 01h)
      044h 2    Initial Value for [4808146h]  ;W_CONFIG_146h
      046h 2    Initial Value for [4808148h]  ;W_CONFIG_148h
      048h 2    Initial Value for [480814Ah]  ;W_CONFIG_14Ah
      04Ah 2    Initial Value for [480814Ch]  ;W_CONFIG_14Ch
      04Ch 2    Initial Value for [4808120h]  ;W_CONFIG_120h
      04Eh 2    Initial Value for [4808122h]  ;W_CONFIG_122h
      050h 2    Initial Value for [4808154h]  ;W_CONFIG_154h
      052h 2    Initial Value for [4808144h]  ;W_CONFIG_144h
      054h 2    Initial Value for [4808130h]  ;W_CONFIG_130h
      056h 2    Initial Value for [4808132h]  ;W_CONFIG_132h
      058h 2    Initial Value for [4808140h]  ;W_CONFIG_140h
      05Ah 2    Initial Value for [4808142h]  ;W_CONFIG_142h
      05Ch 2    Initial Value for [4808038h]  ;W_POWER_TX
      05Eh 2    Initial Value for [4808124h]  ;W_CONFIG_124h
      060h 2    Initial Value for [4808128h]  ;W_CONFIG_128h
      062h 2    Initial Value for [4808150h]  ;W_CONFIG_150h
      064h 69h  Initial 8bit values for BB[0..68h]
      0CDh 1    Unused (00h)

Below for Type2 (ie. when [040h]=2) (Mitsumi MM3155 and RF9008):

      0CEh 24h  Initial 24bit values for RF[0,4,5,6,7,8,9,0Ah,0Bh,1,2,3]
      0F2h 54h  Channel 1..14 2x24bit values for RF[5,6]
      146h 0Eh  Channel 1..14 8bit values for BB[1Eh] (usually somewhat B1h..B7h)
      154h 0Eh  Channel 1..14 8bit values for RF[9].Bit10..14 (usually 10h-filled)

Below for Type3 (ie. when [040h]=3) (Mitsumi MM3218) (and AR6013G):

      --- Type3 values are originated at 0CEh, following addresses depend on:  ---
      1) number of initial values, found at [042h]        ;usually 29h
      2) number of BB indices,     found at [0CEh+[042h]] ;usually 02h
      3) number of RF indices,     found at [043h]        ;usually 02h
      --- Below example addresses assume above values to be set to 29h,02h,02h ---
      0CEh 29h  Initial 8bit values for RF[0..28h]
      0F7h 1    Number of BB indices per channel
      0F8h 1    1st BB index
      0F9h 14   1st BB data for channel 1..14
      107h 1    2nd BB index
      108h 14   2nd BB data for channel 1..14
      116h 1    1st RF index
      117h 14   1st RF data for channel 1..14
      125h 1    2nd RF index
      126h 14   2nd RF data for channel 1..14
      134h 46   Unused (FFh-filled)

Below for both Type2 and Type3:

      162h 1    Unknown (usually 19h..1Ch)
      163h 1    Unused (FFh) (Inside CRC16 region, with config_length=138h)
      164h 99h  Unused (FFh-filled) (Outside CRC16 region, with config_length=138h)
      1FDh 1    DSi/3DS Wifi Board (01h=W015, 02h=W024, 03h=W028);\this was
      1FEh 1    DSi/3DS Wifi Flash (20h=With access point 4/5/6) ; FFh-filled on DS
      1FFh 1    DSi/3DS Same as on DS (FFh)                      ;/

Most of the Wifi settings seem to be always the same values on all currently existing consoles. Except for:
Values that are (obviously) different are the CRC16, and 4th-6th bytes of the MAC address. Also, initial values for BB[01h] and BB[1Eh], and channel 1..14 values for BB[1Eh], and unknown entry [162h] contain different calibration settings on all consoles.
Firmware v5 is having a new wifi ID [2Fh]=03h, and different RF[9] setting.
Firmware v6 (dslite) has wifi ID [2Fh]=05h, and same RF[9] setting as v5, additionally, v6 and up have different 2nd-3rd bytes of the MAC address.
Moreover, a LOT of values are different with Type3 chips (ie. when [040h]=3).
Note
Unlike for Firmware User Settings, the Firmware Header (and Wifi Settings) aren't stored in RAM upon boot. So the data must be retrieved via SPI bus by software.

DS Firmware Wifi Internet Access Points

Connection data 1 at WifiFlash[00020h]*8-400h (eg. 01FA00h/03FA00h/07FA00h)
Connection data 2 at WifiFlash[00020h]*8-300h (eg. 01FB00h/03FB00h/07FB00h)
Connection data 3 at WifiFlash[00020h]*8-200h (eg. 01FC00h/03FC00h/07FC00h)
These three 100h byte regions are used to memorize known internet access points. The NDS firmware doesn't use these regions, but games that support internet are allowed to read (and configure/write) them. The DSi firmware also supports configuring these entries.

      Addr Siz Expl.
      000h 64  Unknown (usually 00h-filled) (no Proxy supported on NDS)
      040h 32  SSID (ASCII name of the access point) (padded with 00h's)
      060h 32  SSID for WEP64 on AOSS router (each security level has its own SSID)
      080h 16  WEP Key 1 (for type/size, see entry E6h)
      090h 16  WEP Key 2  ;\
      0A0h 16  WEP Key 3  ; (usually 00h-filled)
      0B0h 16  WEP Key 4  ;/
      0C0h 4   IP Address           (0=Auto/DHCP)
      0C4h 4   Gateway              (0=Auto/DHCP)
      0C8h 4   Primary DNS Server   (0=Auto/DHCP)
      0CCh 4   Secondary DNS Server (0=Auto/DHCP)
      0D0h 1   Subnet Mask (0=Auto/DHCP, 1..1Ch=Leading Ones) (eg. 6 = FC.00.00.00)
      0D1h ..  Unknown (usually 00h-filled)
      0E6h 1   WEP Mode (0=None, 1/2/3=5/13/16 byte hex, 5/6/7=5/13/16 byte ascii)
      0E7h 1   Status (00h=Normal, 01h=AOSS, FFh=connection not configured/deleted)
      0E8h 1   Zero (not SSID Length, ie. unlike as entry 4,5,6 on DSi)
      0E9h 1   Unknown (usually 00h)
      0EAh 2   DSi only: MTU (Max transmission unit) (576..1500, usually 1400)
      0ECh 3   Unknown (usually 00h-filled)
      0EFh 1   bit0/1/2 - connection 1/2/3 (1=Configured, 0=Not configured)
      0F0h 6   Nintendo Wifi Connection (WFC) 43bit User ID
               (ID=([F0h] AND 07FFFFFFFFFFh)*1000, shown as decimal string
               NNNN-NNNN-NNNN-N000) (the upper 5bit of the last byte are
               containing additional/unknown nonzero data)
      0F6h 8   Unknown (nonzero stuff !?!)
      0FEh 2   CRC16 for Entries 000h..0FDh (with initial value 0000h)

For connection 3: entries [0EFh..0FDh] - always zero-filled?
The location of the first data block is at the User Settings address minus 400h, ie. Firmware Header [00020h]*8-400h.
Connection data 4 at WifiFlash[00020h]*8-A00h (eg. 01F400h) (DSi only)
Connection data 5 at WifiFlash[00020h]*8-800h (eg. 01F600h) (DSi only)
Connection data 6 at WifiFlash[00020h]*8-600h (eg. 01F800h) (DSi only)
The DSi has three extra 200h-byte regions (for use DSi games, with the new WPA/WPA2 encryption support, and with additional proxy support), these extra regions are found under "Advanced Setup" in the DSi firmware's "Internet" configuration menu.

      Addr Siz Expl.
      000h 32  Proxy Authentication Username (ASCII string, padded with 00's)
      000h 32  Proxy Authentication Password (ASCII string, padded with 00's)
      040h 32  SSID (ASCII string, padded with 00's) (see [0E8h] for length)
      060h ..  Maybe same as NDS
      080h 16  WEP Key (zerofilled for WPA)
      0xxh ..  Maybe same as NDS
      0C0h 4   IP Address           (0=Auto/DHCP)
      0C4h 4   Gateway              (0=Auto/DHCP)
      0C8h 4   Primary DNS Server   (0=Auto/DHCP)
      0CCh 4   Secondary DNS Server (0=Auto/DHCP)
      0D0h 1   Subnet Mask (0=Auto/DHCP, 1..1Ch=Leading Ones) (eg. 6 = FC.00.00.00)
      0D1h ..  Unknown (zerofilled)
      0E6h 1   WEP (00h=None/WPA/WPA2, 01h/02h/03h/05h/06h/07h=WEP, same as NDS)
      0E7h 1   WPA (00h=Normal, 10h=WPA/WPA2, 13h=WPS+WPA/WPA2, FFh=unused/deleted)
      0E8h 1   SSID Length in characters (01h..20h, or 00h=unused)
      0E9h 1   Unknown (usually 00h)
      0EAh 2   MTU Value (Max transmission unit) (576..1500, usually 1400)
      0ECh 3   Unknown (usually 00h-filled)
      0EFh 1   bit0/1/2 - connection 4/5/6 (1=Configured, 0=Not configured)
      0F0h 14  Zerofilled (or maybe ID as on NDS, if any such ID exists for DSi?)
      0FEh 2   CRC16 for Entries 000h..0FDh (with initial value 0000h)
      100h 32  Precomputed PSK (based on WPA/WPA2 password and SSID) ;\all zero
      120h 64  WPA/WPA2 password (ASCII string, padded with 00's)    ;/for WEP
      160h 33  Zerofilled
      181h 1   WPA (0=None/WEP, 4=WPA-TKIP, 5=WPA2-TKIP, 6=WPA-AES, 7=WPA2-AES)
      182h 1   Proxy Enable         (00h=None, 01h=Yes)
      183h 1   Proxy Authentication (00h=None, 01h=Yes)
      184h 48  Proxy Name (ASCII string, max 47 chars, padded with 00's)
      1B4h 52  Zerofilled
      1E8h 2   Proxy Port (16bit)
      1EAh 20  Zerofilled
      1FEh 2   CRC16 for Entries 100h..1FDh (with initial value 0000h) (0=deleted)

The location of the first data block (aka settings number 4) is at the User Settings address minus A00h, ie. Firmware Header [00020h]*8-A00h.
Observe that NDS consoles do have NDS Firmware bootcode/data in that area, so those new regions can exist on DSi only (or on homebrew NDS firmwares). Presence of the new regions is indicated in Firmware Header [001FEh], that byte is usually FFh=NDS or 20h=DSi, the DSi browser does internally replace FFh by 10h, and does then check if byte>=20h (ie. the new areas exist if the byte is 20h..FEh).
Note that the Proxy feature can be used to redirect internet access (when using a custom proxy server, one could redirect commercial games to homebrew servers; as done by the http://pbsds.net/ project) (actually the same should be possible with the DNS server entry, possibly with less traffic).
Note
The location of the user settings & connection data varies (eg. 01Fxxxh=DSi, 03Fxxxh=NDS, 07Fxxxh=iQueDS).

DS Firmware User Settings

Current Settings (RAM 27FFC80h-27FFCEFh)
User Settings 0 (Firmware 3FE00h-3FEFFh) ;(DSi & iQue use different address,
User Settings 1 (Firmware 3FF00h-3FFFFh) ;see Firmware Header [020h])

      Addr Size Expl.
      000h  2   Version (5) (Always 5, for all NDS/DSi Firmware versions)
      002h  1   Favorite color (0..15) (0=Gray, 1=Brown, etc.)
      003h  1   Birthday month (1..12) (Binary, non-BCD)
      004h  1   Birthday day   (1..31) (Binary, non-BCD)
      005h  1   Not used (zero)
      006h  20  Nickname string in UTF-16 format
      01Ah  2   Nickname length in characters    (0..10)
      01Ch  52  Message string in UTF-16 format
      050h  2   Message length in characters     (0..26)
      052h  1   Alarm hour     (0..23) (Binary, non-BCD)
      053h  1   Alarm minute   (0..59) (Binary, non-BCD)
      054h  2
      056h  1   80h=enable alarm (huh?), bit 0..6=enable?
      057h  1   Zero (1 byte)
      058h  2x2 Touch-screen calibration point (adc.x1,y1) 12bit ADC-position
      05Ch  2x1 Touch-screen calibration point (scr.x1,y1) 8bit pixel-position
      05Eh  2x2 Touch-screen calibration point (adc.x2,y2) 12bit ADC-position
      062h  2x1 Touch-screen calibration point (scr.x2,y2) 8bit pixel-position
      064h  2   Language and Flags (see below)
      066h  1   Year (2000..2255) (when having entered date in the boot menu)
      067h  1   Unknown (usually 00h...08h or 78h..7Fh or so)
      068h  4   RTC Offset (difference in seconds when RTC time/date was changed)
      06Ch  4   Not used (FFh-filled, sometimes 00h-filled) (=MSBs of above?)

Below not stored in RAM (found only in FLASH memory)...

      070h  2   Update counter (used to check latest) (must be 0000h..007Fh)
      072h  2   CRC16 of entries 00h..6Fh (70h bytes)
      074h  8Ch Not used (FFh-filled) (or extended data, see below)

Below extended data was invented for iQue DS (for adding the chinese language setting), and is also included in Nintendo DSi models. Presence of extended data is indicated in Firmware Header entry [1Dh].Bit6.

      074h  1   Unknown (01h) (maybe version?)
      075h  1   Extended Language (0..5=Same as Entry 064h, plus 6=Chinese)
                (for language 6, entry 064h defaults to english; for compatibility)
                (for language 0..5, both entries 064h and 075h have same value)
      076h  2   Bitmask for Supported Languages (Bit0..6)
                (007Eh for iQue DS, ie. with chinese, but without japanese)
                (0042h for iQue DSi, chinese (and english, but only for NDS mode))
                (003Eh for DSi/EUR, ie. without chinese, and without japanese)
      078h  86h Not used (FFh-filled on iQue DS, 00h-filled on DSi)
      0FEh  2   CRC16 of entries 74h..FDh (8Ah bytes)

Note: The DSi has some more settings (eg. Country (additionally to Language), Parental Controls, and a surreal fake Wireless-Disable option; which does only disable the Wifi LED, the actual Wifi transmission does still work).
That new settings are stored in eMMC files. The old/above User Settings are stored in those files too (and copy of those User Settings is stored in Wifi FLASH, as described above; that copy is intended mainly for backwards compatibilty with NDS games).
DSi SD/MMC Firmware System Settings Data Files
DSi Backlight level and DSi sound volume seem to be stored in the BPTWL chip (or possibly in its attached I2C potentiometer).
Language and Flags (Entry 064h)

      Bit
      0..2 Language (0=Japanese, 1=English, 2=French, 3=German,
           4=Italian, 5=Spanish, 6..7=Reserved) (for Chinese see Entry 075h)
           (the language setting also implies time/data format)
      3    GBA mode screen selection (0=Upper, 1=Lower)
      4-5  Backlight Level    (0..3=Low,Med,High,Max) (DS-Lite only)
      6    Bootmenu Disable   (0=Manual/bootmenu, 1=Autostart Cartridge)
      9    Settings Lost (1=Prompt for User Info, and Language, and Calibration)
      10   Settings Okay (0=Prompt for User Info)
      11   Settings Okay (0=Prompt for User Info) (Same as Bit10)
      12   No function
      13   Settings Okay (0=Prompt for User Info, and Language)
      14   Settings Okay (0=Prompt for User Info) (Same as Bit10)
      15   Settings Okay (0=Prompt for User Info) (Same as Bit10)

The Health and Safety message is skipped if Bit9=1, or if one or more of the following bits is zero: Bits 10,11,13,14,15. However, as soon as entering the bootmenu, the Penalty-Prompt occurs.
Note: There are two User Settings areas in the firmware chip, at offset 3FE00h and 3FF00h, if both areas have valid CRCs, then the current/newest area is that whose Update Counter is one bigger than in the other/older area.

      IF count1=((count0+1) AND 7Fh) THEN area1=newer ELSE area0=newer

When changing settings, the older area is overwritten with new data (and incremented Update Counter). The two areas allow to recover previous settings in case of a write-error (eg. on a battery failure during write).
Battery Removal
Even though the battery is required only for the RTC (not for the firmware flash memory), most of the firmware user settings are reset when removing the battery. This appears to be a strange bug-or-feature of the DS bios, at least, fortunately, it still keeps the rest of the firmware intact.

DS Firmware Extended Settings

Extended Settings contain some additional information which is not supported by the original firmware (current century, date/time formats, temperature calibration, etc.), the settings are supported by Nocash Firmware, by the no$gba emulator, and may be eventually also supported by other emulators. If present, the values can be used by games, otherwise games should use either whatever default settings, or contain their own configuration menu.
Extended Settings - loaded to 23FEE00h (aka fragments of NDS9 boot code)

      Addr Siz Expl.
      00h  8  ID "XbooInfo"
      08h  2  CRC16 Value [0Ch..0Ch+Length-1]
      0Ah  2  CRC16 Length (from 0Ch and up)
      0Ch  1  Version (currently 01h)
      0Dh  1  Update Count (newer = (older+1) AND FFh)
      0Eh  1  Bootmenu Flags
                Bit6   Important Info  (0=Disable, 1=Enable)
                Bit7   Bootmenu Screen (0=Upper, 1=Lower)
      0Fh  1  GBA Border (0=Black, 1=Gray Line)
      10h  2  Temperature Calibration TP0 ADC value  (x16) (sum of 16 ADC values)
      12h  2  Temperature Calibration TP1 ADC value  (x16) (sum of 16 ADC values)
      14h  2  Temperature Calibration Degrees Kelvin (x100) (0=none)
      16h  1  Temperature Flags
                Bit0-1 Format (0=Celsius, 1=Fahrenheit, 2=Reaumur, 3=Kelvin)
      17h  1  Backlight Intensity (0=0ff .. FFh=Full)
      18h  4  Date Century Offset       (currently 20, for years 2000..2099)
      1Ch  1  Date Month Recovery Value (1..12)
      1Dh  1  Date Day Recovery Value   (1..31)
      1Eh  1  Date Year Recovery Value  (0..99)
      1Fh  1  Date/Time Flags
                Bit0-1 Date Format   (0=YYYY-MM-DD, 1=MM-DD-YYYY, 2=DD-MM-YYYY)
                Bit2   Friendly Date (0=Raw Numeric, 1=With Day/Month Names)
                Bit5   Time DST      (0=Hide DST, 1=Show DST=On/Off)
                Bit6   Time Seconds  (0=Hide Seconds, 1=Show Seconds)
                Bit7   Time Format   (0=24 hour, 1=12 hour)
      20h  1  Date Separator      (Ascii, usually Slash, or Dot)
      21h  1  Time Separator      (Ascii, usually Colon, or Dot)
      22h  1  Decimal Separator   (Ascii, usually Comma, or Dot)
      23h  1  Thousands Separator (Ascii, usually Comma, or Dot)
      24h  1  Daylight Saving Time (Nth)
                 Bit 0-3 Activate on (0..4 = Last,1st,2nd,3rd,4th)
                 Bit 4-7 Deactivate on (0..4 = Last,1st,2nd,3rd,4th)
      25h  1  Daylight Saving Time (Day)
                 Bit 0-3 Activate on (0..7 = Mon,Tue,Wed,Thu,Fri,Sat,Sun,AnyDay)
                 Bit 4-7 Deactivate on (0..7 = Mon,Tue,Wed,Thu,Fri,Sat,Sun,AnyDay)
      26h  1  Daylight Saving Time (of Month)
                 Bit 0-3 Activate DST in Month   (1..12)
                 Bit 4-7 Deactivate DST in Month (1..12)
      27h  1  Daylight Saving Time (Flags)
                 Bit 0   Current DST State (0=Off, 1=On)
                 Bit 1   Adjust DST Enable (0=Disable, 1=Enable)

Note: With the original firmware, the memory region at 23FEE00h and up contains un-initialized, non-zero-filled data (fragments of boot code).

DS File Formats

DS Files - 2D Video
DS Files - 3D Video (mostly unknown)
DS Files - Sound (SDAT etc.)
DS Files - Text Messages (MESG)
DS Files - Text Manuals
DS Cartridge Nitro Font Resource Format
DS Cartridge NitroROM and NitroARC File Systems
LZ Decompression Functions
LZ Decompression Functions ASH0
ZIP Decompression
DS Encrypted Arika Archives with ALZ1 compression

DS Files - Text Messages (MESG)

MESG files contain localized strings (like "Okay" and "Cancel" and longer text messages). Different languages are stored separate message files, usually with .bmg extension. MESG files are used in NDS/DSi titles (in little endian), and also on Wii (in big endian).
DSi titles are: DSi Shop, Launcher, System Settings, and DSi Camera (however, the DSi-to-3DS Transfer Tool uses the newer MsgPrjBn/MsgStdBn format; despite of being a DSi program).
MESG Header

      000h 8     ID "MESGbmg1"         ;or "GSEM1gmb" in Super Mario 64 DS
      008h 4     Total Filesize        ;or Filesize+1 in Super Mario 64 DS
      00Ch 4     Number of Chunks (2=INF1+DAT1, 3=INF1+DAT1+MID1)
      010h 1     Encoding (1=CP1252, 2=UTF-16, 3=Shift-JIS, 4=UTF-8)
      011h 15    Padding (0)

Encoding UTF-16 appears to be most common (Super Mario 64 DS uses Shift-JIS).
INF1 Chunk (Message Info)
It comes just after the BMG header. It contains information (like pointers) about the messages.

      000h 4     Chunk ID "INF1"       ;or "1FNI" in Super Mario 64 DS
      004h 4     Chunk Size
      008h 2     Number of messages (N)
      00Ah 2     Size of each INF data in bytes  ;or in BITs in Super Mario 64 DS
      00Ch 4     "BMG file ID = ID for this BMG file (usually 0)"
      010h N*siz Message Info (32bit offset from DAT1+8, and optional attributes)

For each message, there is a INF data about it. At Wii Fit, there is just the message offset. At Wii Fit Plus, there is two another fields.

      000h 4     Offset to the message (after DAT1+8 section header)
      004h siz-4 Attributes/flags (if entrysize is bigger than 4 bytes)

The optional Attribute bits could be used to select different font types or window styles.
DAT1 Chunk (Message Strings)

      000h 4     Chunk ID "DAT1"       ;or "1TAD" in Super Mario 64 DS
      004h 4     Chunk Size            ;or Size+1 in Super Mario 64 DS
      008h ..    Message strings (usually UTF-16, depending on Encoding in header)

The DSi Camera uses both char 001Ah and 0025h for escape codes.
UTF-16 string characters:

      0000                           End of String (except inside Escape sequences)
      000A                           Linebreak
      001A,nn,command,parameters     Escape Sequences (nn=length in bytes)
      001A,08,00,0000,00xx           Set font size (64h=100%=Normal Size)
      001A,08,00,0001,00xx           Set text color to xx
      001A,08,01,0000,24xx           Draw Unicode char U+2460..246E ;"(1)"..("15)"
      001A,08,01,0000,xxxx           Draw Unicode char U+E068..F12B ;custom?
      001A,06,02,0000                Draw Name of current player
      001A,0A,02,0010,000x,000w      Draw Integer from index x with w digits
      001A,08,02,0011,00xx           Unknown (with xx=0..8)
      001A,08,02,0012,0000           Draw Name of a player
      001A,08,02,0013,0000           Unknown
      001A,08,02,0014,0000           Unknown
      001A,08,02,0015,0000           Unknown
      001A,0A,02,0016,0000,0000      Unknown
      001A,08,02,0017,0000           Unknown
      001A,08,02,0020,0000           Draw Name of a Wii friend
      001A,08,03,0010,0000           Unknown
      001A,0C,04,0000,000x,yyyy,zzzz Unknown (x=0..1, y=0524..14A4, and z=y+1)
      0025,00xx,00yy,00zz            Escape codes in form of "%xyz" (or similar)
      00xx                           ASCII Characters 20h..7Eh
      E0xx                           Custom button symbols (eg. in DSi Launcher)

Shift-JIS (or whatever) strings in Super Mario 64 DS:

      0D       Linebreak?
      10..1F   Escape codes?
      xx,xx    Unknown (doesn't really look like english Shift-JIS characters)
      FF       End of String

MID1 Chunk (Message IDs) (if any)

      000h 4     Chunk ID "MID1"
      004h 4     Chunk Size
      008h 2     Number of messages (same as in INF1 block)
      00Ah 2     Unknown (usually 1000h)
      00Ch 4     Padding (0)
      010h 4*N   Message IDs

Messages can be repeated in the different files (such like menu and ingame), if so, all messages with the same message ID of the same language are always having the same text, no differences between the text files can be found.
"Elements with the same table index are attributes (not IDs?) for the same string."
FLW1 and FLT1 Chunks (if any)
Some games are reportedly having additional "FLW1" and "FLT1" chunks. Unknown which games, and unknown what for, and unknown if such chunks exist in any DS games (or only in Wii games or whatever).
Thanks to http://wiki.tockdom.com/wiki/BMG

DS Files - Text Manuals

Manual files are common in DSiware download titles, unknown if DS/DSi cartridges did also use that files (or if they did stick with print manuals).
Used in DSi Flipnote, Sudoku, Paper Plane, Deep Psyche, Dr. Mario, DSi-to-3DS Transfer Tool.
Usually found in "rom:\..\manpages_narc.blz" (with two folders in the .blz file, "arc" for the manual, and "gpArc" with a quick reference on how to read the manual; the latter containing only two "pages", without "content" file).
NTLI File (manual language info) (in "ntli" folder)

      000h 4     ID "NTLI"
      004h 2     Byte Order  (FEFFh)
      006h 2     Version     (can be 0200h)
      008h 4     Total Filesize
      00Ch 2     Header Size (10h)
      00Eh 4     Number of Chunks (usually 1 = mtl1)

mtl1 Chunk

      000h 4     Chunk ID "mtl1"
      004h 4     Chunk Size
      008h 4     Number of supported languages
      00Ch 2*N   Language IDs (two-letter ASCII spelled backwards)

Known IDs are ne=English, rf=French, se=Spanish, ti=Italian, ed=German.
EUR games do usually support 5 languages (Deep Psyche supports less).
IDs for Japanese/Chinese/Korean are unknown (also unknown if US has different IDs for english/spanish etc, and if portugese or so do exist on DSi).
Note: The two-letters do directly translate to the "ntmc\xx\" and "ntpg\xx\" folder names.
NTMC File (manual contents) (in "ntmc\xx\" folders)
The content contains "hyperlinks" to the actual chapters. A chapter can be divided into subsections (with the subsections being shown at the right of the main chapter name).

      000h 4     ID "NTMC"
      004h 2     Byte Order  (FEFFh)
      006h 2     Version     (can be 0200h)
      008h 4     Total Filesize
      00Ch 2     Header Size (10h)
      00Eh 4     Number of Chunks (usually 3 = nap1+txp1+mtc1)

nap1 Chunk

      000h 4     Chunk ID "nap1"
      004h 4     Chunk Size
      008h 4     Number of chapters (aka pages) minus 1?  (eg. 18h=19h)
      00Ch 4*N   Offsets to filenames (from nap+0Ch)
      ...  ..    Filenames (ASCII, terminated by 00h)

txp1 Chunk

      000h 4     Chunk ID "txp1"
      004h 4     Chunk Size
      008h 4     Number of something?? minus 1            (eg. 25h=26h)
      00Ch 4*N   Offsets to something?? (from txp1+0Ch)
      ...  ..    Somewhat corrupt UTF-16 strings (many aborted with char 20xxh)

mtc1 Chunk

      000h 4     Chunk ID "mtc1"
      004h 4     Chunk Size
      008h 4     Number of dunno what                  (eg. 0Dh=Much more?)
      00Ch 2*?   16bit Indices in txp1? (eg. 0000h..0025h)

NTPG File (manual pages) (or rather chapters?) (in "ntpg\xx\" folders)
The pages can contain text, tables, and symbols/images/screenshots (there appears to be no support for hyperlinks inside of the pages; probably because they default to be displayed on upper screen, without touchscreen support).

      000h 4     ID "NTPC"
      004h 2     Byte Order  (FEFFh)
      006h 2     Version     (can be 0200h)
      008h 4     Total Filesize
      00Ch 2     Header Size (10h)
      00Eh 4     Number of Chunks (usually 7 = nap1+txp1+pag1+pan1+pas1+txt1+pae1)

nap1 Chunk

      000h 4     Chunk ID "nap1"
      004h 4     Chunk Size (10h)
      008h 4     Zero (unlike as in NTMC file)
      00Ch 4     Unknown (4)

txp1 Chunk

      000h 4     Chunk ID "txp1"
      004h 4     Chunk Size
      008h 4     Number of something?? minus 1            (eg. 02h=03h)
      00Ch 4*N   Offsets to something?? (from txp1+0Ch)
      ...  ..    UTF-16 strings (Headline, Body, Footer?)

pag1 Chunk

      000h 4     Chunk ID "pag1"
      004h 4     Chunk Size (10h)
      008h 2?    0000h text color black?
      00Ah 2?    0160h link color or so?
      00Ch 2?    7FFFh bg color white?
      00Eh 2?    0000h

pan1 Chunk

      000h 4     Chunk ID "pan1"
      004h 4     Chunk Size (10h)
      008h 2?    0000h
      00Ah 2?    0000h
      00Ch 2?    0100h
      00Eh 2?    0160h link color or so?

pas1 Chunk (start?)

      000h 4     Chunk ID "pan1"
      004h 4     Chunk Size (0Ch)
      008h 4?    00000001h

txt1 Chunk

      000h 4     Chunk ID "txt1"
      004h 4     Chunk Size
      008h 2?    0008h
      00Ah 2?    0008h
      00Ch 2?    00F0h
      00Eh 2?    0150h
      010h 2?    0001h
      012h 2?    0015h  Number of 8-byte entries? start/end line-wrapping list?
      014h 2?    000Dh
      016h 2?    0010h
      018h 4?    00000000h
      01Ch 4?    00001CE7h
      020h 4?    00000000h
      024h 4?    00000000h
      028h N*8   Unknown 8-byte entries? (00xxh,0010h,0000h,00yyh)
                 Or maybe positioning for symbols/images/tables?

pae1 Chunk (end?)

      000h 4     Chunk ID "pae1"
      004h 4     Chunk Size (08h)

NTTF File (manual graphics/symbols) (in "nttf" folder)

      000h 2  Bitmap Width in bytes (eg. 0Fh, 10h, 14h, 40h, 60h)
      002h 2  Bitmap Height         (eg. 12h, 0Eh, 14h, 30h, 47h)
      004h 1  Unknown (04h) (maybe color depth)
      005h 1  Unknown (00h or 01h) (often same as [007h], but not always)
      006h 2  Number of Palette entries (usually 10h, 80h, or 100h)
      008h 8  Zerofilled
      010h .. Palette data (with 16bit values in range 0000h..7FFFh)
      ...  .. Bitmap data (seems to be always 8bpp)

Notes
DSi manuals are using the TWLFontTable.dat system font (Flipnote, at least).
3DS manuals consist of CLYT and CLIM files (inside of a manual BCMA darc archive in a NCCH file).

DS Wireless Communications

DS Wifi I/O Map
DS Wifi Control
DS Wifi Interrupts
DS Wifi Power-Down Registers
DS Wifi Receive Control
DS Wifi Receive Buffer
DS Wifi Receive Statistics
DS Wifi Transmit Control
DS Wifi Transmit Buffers
DS Wifi Transmit Errors
DS Wifi Status
DS Wifi Timers
DS Wifi Multiplay Master
DS Wifi Multiplay Slave
DS Wifi Configuration Ports
DS Wifi Baseband Chip (BB)
DS Wifi RF Chip
DS Wifi RF9008 Registers
DS Wifi Unknown Registers
DS Wifi Unused Registers
DS Wifi Initialization
DS Wifi Flowcharts
DS Wifi Hardware Headers
DS Wifi Nintendo Beacons
DS Wifi Nintendo DS Download Play
DS Wifi IEEE802.11 Frames
DS Wifi IEEE802.11 Managment Frames (Type=0)
DS Wifi IEEE802.11 Control and Data Frames (Type=1 and 2)
DS Wifi WPA/WPA2 Handshake Messages (EAPOL)
DS Wifi WPA/WPA2 Keys and MICs
DS Wifi WPA/WPA2 Encryption
DS Wifi FFC ID
DS Wifi Dslink/Wifiboot Protocol
DS Firmware Wifi Calibration Data
DS Firmware Wifi Internet Access Points
2.4GHz band, Wireless LAN (WLAN) IEEE802.11b protocol
Credits
A very large part of the DS Wifi chapters is based on Stephen Stair's great DS Wifi document, thanks there.

DS Wifi I/O Map

Notice
Wifi Registers & RAM cannot be written to by STRB opcodes (ignored).
Registers - NDS7 - 4808000h..4808FFFh

      Address  Dir   Name            r/w  [Init] Description
      4808000h R     W_ID            ---- [1440] Chip ID (1440h=DS, C340h=DS-Lite)
      4808004h R/W   W_MODE_RST      9fff [0000] Mode/Reset
      4808006h R/W   W_MODE_WEP      --7f [0000] Mode/Wep modes
      4808008h R/W   W_TXSTATCNT     ffff [0000] Beacon Status Request
      480800Ah R/W   W_X_00Ah        ffff [0000] [bit7 - ingore rx duplicates]
      4808010h R/W   W_IF            ackk [0000] Wifi Interrupt Request Flags
      4808012h R/W   W_IE            ffff [0000] Wifi Interrupt Enable
      4808018h R/W   W_MACADDR_0     ffff [0000] Hardware MAC Address, 1st 2 bytes
      480801Ah R/W   W_MACADDR_1     ffff [0000] Hardware MAC Address, next 2 bytes
      480801Ch R/W   W_MACADDR_2     ffff [0000] Hardware MAC Address, last 2 bytes
      4808020h R/W   W_BSSID_0       ffff [0000] BSSID (first 2 bytes)
      4808022h R/W   W_BSSID_1       ffff [0000] BSSID (next 2 bytes)
      4808024h R/W   W_BSSID_2       ffff [0000] BSSID (last 2 bytes)
      4808028h R/W   W_AID_LOW       ---f [0000] usually as lower 4bit of AID value
      480802Ah R/W   W_AID_FULL      -7ff [0000] AID value assigned by a BSS.
      480802Ch R/W   W_TX_RETRYLIMIT ffff [0707] Tx Retry Limit (set from 00h-FFh)
      480802Eh R/W   W_INTERNAL      ---1 [0000]
      4808030h R/W   W_RXCNT         ff0e [0000] Receive control
      4808032h R/W   W_WEP_CNT       ffff [0000] WEP engine enable
      4808034h R?    W_INTERNAL      0000 [0000] bit0,1 (see ports 004h,040h,1A0h)

Power-Down Registers (and Random Generator)

      4808036h R/W   W_POWER_US      ---3 [0001]
      4808038h R/W   W_POWER_TX      ---7 [0003]
      480803Ch R/W   W_POWERSTATE    -r-2 [0200]
      4808040h R/W   W_POWERFORCE    8--1 [0000]
      4808044h R     W_RANDOM        0xxx [0xxx]
      4808048h R/W   W_POWER_?       ---3 [0000]

WLAN Memory Ports

      4808050h R/W   W_RXBUF_BEGIN   ffff [4000]
      4808052h R/W   W_RXBUF_END     ffff [4800]
      4808054h R     W_RXBUF_WRCSR   0rrr [0000]
      4808056h R/W   W_RXBUF_WR_ADDR -fff [0000]
      4808058h R/W   W_RXBUF_RD_ADDR 1ffe [0000]
      480805Ah R/W   W_RXBUF_READCSR -fff [0000]
      480805Ch R/W   W_RXBUF_COUNT   -fff [0000]
      4808060h R     W_RXBUF_RD_DATA rrrr [xxxx]
      4808062h R/W   W_RXBUF_GAP     1ffe [0000]
      4808064h R/W   W_RXBUF_GAPDISP -fff [0000]
      4808068h R/W   W_TXBUF_WR_ADDR 1ffe [0000]
      480806Ch R/W   W_TXBUF_COUNT   -fff [0000]
      4808070h W     W_TXBUF_WR_DATA xxxx [xxxx]
      4808074h R/W   W_TXBUF_GAP     1ffe [0000]
      4808076h R/W   W_TXBUF_GAPDISP 0fff [0000]

xxx

      4808078h W     W_INTERNAL      mirr [mirr] Read: Mirror of 068h
      4808080h R/W   W_TXBUF_BEACON  ffff [0000] Beacon Transmit Location
      4808084h R/W   W_TXBUF_TIM     --ff [0000] Beacon TIM Index in Frame Body
      4808088h R/W   W_LISTENCOUNT   --ff [0000] Listen Count
      480808Ch R/W   W_BEACONINT     -3ff [0064] Beacon Interval
      480808Eh R/W   W_LISTENINT     --ff [0000] Listen Interval
      4808090h R/W   W_TXBUF_CMD     ffff [0000]    (used by firmware part4)
      4808094h R/W   W_TXBUF_REPLY1  ffff [0000]    (used by firmware part4)
      4808098h R     W_TXBUF_REPLY2  0000 [0000]    (used by firmware part4)
      480809Ch R/W   W_INTERNAL      ffff [0050] value 4x00h --> preamble+x*12h us?
      48080A0h R/W   W_TXBUF_LOC1    ffff [0000]
      48080A4h R/W   W_TXBUF_LOC2    ffff [0000]
      48080A8h R/W   W_TXBUF_LOC3    ffff [0000]
      48080ACh W     W_TXREQ_RESET   fixx [0050]
      48080AEh W     W_TXREQ_SET     fixx [0050]
      48080B0h R     W_TXREQ_READ    --1f [0010]
      48080B4h W     W_TXBUF_RESET   0000 [0000]    (used by firmware part4)
      48080B6h R     W_TXBUSY        0000 [0000]    (used by firmware part4)
      48080B8h R     W_TXSTAT        0000 [0000]
      48080BAh ?     W_INTERNAL      0000 [0000]
      48080BCh R/W   W_PREAMBLE      ---3 [0001]
      48080C0h R/W x W_CMD_TOTALTIME ffff [0000]    (used by firmware part4)
      48080C4h R/W x W_CMD_REPLYTIME ffff [0000]    (used by firmware part4)
      48080C8h ?     W_INTERNAL      0000 [0000]
      48080D0h R/W   W_RXFILTER      1fff [0401]
      48080D4h R/W   W_CONFIG_0D4h   ---3 [0001]
      48080D8h R/W   W_CONFIG_0D8h   -fff [0004]
      48080DAh R/W   W_RX_LEN_CROP   ffff [0602]
      48080E0h R/W   W_RXFILTER2     ---f [0008]

Wifi Timers

      48080E8h R/W   W_US_COUNTCNT   ---1 [0000] Microsecond counter enable
      48080EAh R/W   W_US_COMPARECNT ---1 [0000] Microsecond compare enable
      48080ECh R/W   W_CONFIG_0ECh   3f1f [3F03]
      48080EEh R/W   W_CMD_COUNTCNT  ---1 [0001]
      48080F0h R/W   W_US_COMPARE0   fc-- [FC00] Microsecond compare, bits 0-15
      48080F2h R/W   W_US_COMPARE1   ffff [FFFF] Microsecond compare, bits 16-31
      48080F4h R/W   W_US_COMPARE2   ffff [FFFF] Microsecond compare, bits 32-47
      48080F6h R/W   W_US_COMPARE3   ffff [FFFF] Microsecond compare, bits 48-63
      48080F8h R/W   W_US_COUNT0     ffff [0000] Microsecond counter, bits 0-15
      48080FAh R/W   W_US_COUNT1     ffff [0000] Microsecond counter, bits 16-31
      48080FCh R/W   W_US_COUNT2     ffff [0000] Microsecond counter, bits 32-47
      48080FEh R/W   W_US_COUNT3     ffff [0000] Microsecond counter, bits 48-63
      4808100h ?     W_INTERNAL      0000 [0000]
      4808102h ?     W_INTERNAL      0000 [0000]
      4808104h ?     W_INTERNAL      0000 [0000]
      4808106h ?     W_INTERNAL      0000 [0000]
      480810Ch R/W   W_CONTENTFREE   ffff [0000] ...
      4808110h R/W   W_PRE_BEACON    ffff [0000]
      4808118h R/W   W_CMD_COUNT     ffff [0000]
      480811Ch R/W   W_BEACONCOUNT1  ffff [0000] reloaded with W_BEACONINT

Configuration Ports (and some other Registers)

      4808120h R/W   W_CONFIG_120h   81ff [0048] init from firmware[04Ch]
      4808122h R/W   W_CONFIG_122h   ffff [4840] init from firmware[04Eh]
      4808124h R/W   W_CONFIG_124h   ffff [0000] init from firmware[05Eh], or 00C8h
      4808126h ?     W_INTERNAL      fixx [ 0080]
      4808128h R/W   W_CONFIG_128h   ffff [0000] init from firmware[060h], or 07D0h
      480812Ah ?     W_INTERNAL      fixx [1000] lower 12bit same as W_CONFIG_128h
      4808130h R/W   W_CONFIG_130h   -fff [0142] init from firmware[054h]
      4808132h R/W   W_CONFIG_132h   8fff [8064] init from firmware[056h]
      4808134h R/W   W_BEACONCOUNT2  ffff [FFFF] ...
      4808140h R/W   W_CONFIG_140h   ffff [0000] init from firmware[058h], or xx
      4808142h R/W   W_CONFIG_142h   ffff [2443] init from firmware[05Ah]
      4808144h R/W   W_CONFIG_144h   --ff [0042] init from firmware[052h]
      4808146h R/W   W_CONFIG_146h   --ff [0016] init from firmware[044h]
      4808148h R/W   W_CONFIG_148h   --ff [0016] init from firmware[046h]
      480814Ah R/W   W_CONFIG_14Ah   --ff [0016] init from firmware[048h]
      480814Ch R/W   W_CONFIG_14Ch   ffff [162C] init from firmware[04Ah]
      4808150h R/W   W_CONFIG_150h   ff3f [0204] init from firmware[062h], or 202h
      4808154h R/W   W_CONFIG_154h   7a7f [0058] init from firmware[050h]

Baseband Chip Ports

      4808158h W     W_BB_CNT        mirr [00B5] BB Access Start/Direction/Index
      480815Ah W     W_BB_WRITE      ???? [0000] BB Access data byte to write
      480815Ch R     W_BB_READ       00rr [00B5] BB Access data byte read
      480815Eh R     W_BB_BUSY       000r [0000] BB Access Busy flag
      4808160h R/W   W_BB_MODE       41-- [0100] BB Access Mode
      4808168h R/W   W_BB_POWER      8--f [800D] BB Access Powerdown

Internal Stuff

      480816Ah ?     W_INTERNAL      0000 [0001] (or 0000h?)
      4808170h ?     W_INTERNAL      0000 [0000]
      4808172h ?     W_INTERNAL      0000 [0000]
      4808174h ?     W_INTERNAL      0000 [0000]
      4808176h ?     W_INTERNAL      0000 [0000]
      4808178h W     W_INTERNAL      fixx [0800] Read: mirror of 17Ch

RF Chip Ports

      480817Ch R/W   W_RF_DATA2      ffff [0800]
      480817Eh R/W   W_RF_DATA1      ffff [C008]
      4808180h R     W_RF_BUSY       000r [0000]
      4808184h R/W   W_RF_CNT        413f [0018]

xxx

      4808190h R/W   W_INTERNAL      ffff [0000]
      4808194h R/W   W_TX_HDR_CNT    ---7 [0000] used by firmware part4 (0 or 6)
      4808198h R/W   W_INTERNAL      ---f [0000]
      480819Ch R     W_RF_PINS       fixx [0004]
      48081A0h R/W   W_X_1A0h        -933 [0000] used by firmware part4 (0 or 823h)
      48081A2h R/W   W_X_1A2h        ---3 [0001] used by firmware part4
      48081A4h R/W   W_X_1A4h        ffff [0000] "Rate used when signal test..."

Wifi Statistics

      48081A8h R     W_RXSTAT_INC_IF rrrr [0000] Stats Increment Flags
      48081AAh R/W   W_RXSTAT_INC_IE ffff [0000] Stats Increment IRQ Enable
      48081ACh R     W_RXSTAT_OVF_IF rrrr [0000] Stats Half-Overflow Flags
      48081AEh R/W   W_RXSTAT_OVF_IE ffff [0000] Stats Half-Overflow IRQ Enable
      48081B0h R/W   W_RXSTAT        --ff [0000]
      48081B2h R/W   W_RXSTAT        ffff [0000] RX_LengthRateErrorCount
      48081B4h R/W   W_RXSTAT        rrff [0000] ... firmware uses also MSB ... ?
      48081B6h R/W   W_RXSTAT        ffff [0000]
      48081B8h R/W   W_RXSTAT        --ff [0000]
      48081BAh R/W   W_RXSTAT        --ff [0000]
      48081BCh R/W   W_RXSTAT        ffff [0000]
      48081BEh R/W   W_RXSTAT        ffff [0000]
      48081C0h R/W   W_TX_ERR_COUNT  --ff [0000] TransmitErrorCount
      48081C4h R     W_RX_COUNT      fixx [0000]

[1D0 - 1DE are 15 entries related to multiplayer response errors]

      48081D0h R/W   W_CMD_STAT      ff-- [0000]
      48081D2h R/W   W_CMD_STAT      ffff [0000]
      48081D4h R/W   W_CMD_STAT      ffff [0000]
      48081D6h R/W   W_CMD_STAT      ffff [0000]
      48081D8h R/W   W_CMD_STAT      ffff [0000]
      48081DAh R/W   W_CMD_STAT      ffff [0000]
      48081DCh R/W   W_CMD_STAT      ffff [0000]
      48081DEh R/W   W_CMD_STAT      ffff [0000]

Internal Diagnostics Registers (usually not used for anything)

      48081F0h R/W   W_INTERNAL      ---3 [0000]
      4808204h ?     W_INTERNAL      fixx [0000]
      4808208h ?     W_INTERNAL      fixx [0000]
      480820Ch W     W_INTERNAL      fixx [0050]
      4808210h R     W_TX_SEQNO      fixx [0000]
      4808214h R     W_RF_STATUS     XXXX [0009]    (used by firmware part4)
      480821Ch W     W_IF_SET        fbff [0000] Force Interrupt (set bits in W_IF)
      4808220h R/W   W_INTERNAL      ffff [0000] Bit0-1: Enable/Disable WifiRAM
                                                 (locks memory at 4000h-5FFFh)
      4808224h R/W   W_INTERNAL      ---3 [0003]
      4808228h W     W_X_228h        fixx [0000]    (used by firmware part4) (bit3)
      4808230h R/W   W_INTERNAL      --ff [0047]
      4808234h R/W   W_INTERNAL      -eff [0EFF]
      4808238h R/W   W_INTERNAL      ffff [0000] ;rx_seq_no-60h+/-x   ;why that?
                                       ;other day: fixed value, not seq_no related?
      480823Ch ?     W_INTERNAL      fixx [0000] like W_TXSTAT... ONLY for beacons?
      4808244h R/W   W_X_244h        ffff [0000]    (used by firmware part4)
      4808248h R/W   W_INTERNAL      ffff [0000]
      480824Ch R     W_INTERNAL      fixx [0000] ;rx_mac_addr_0
      480824Eh R     W_INTERNAL      fixx [0000] ;rx_mac_addr_1
      4808250h R     W_INTERNAL      fixx [0000] ;rx_mac_addr_2
      4808254h ?     W_CONFIG_254h   fixx [0000] (read: FFFFh=DS, EEEEh=DS-Lite)
      4808258h ?     W_INTERNAL      fixx [0000]
      480825Ch ?     W_INTERNAL      fixx [0000]
      4808260h ?     W_INTERNAL      fixx [ 0FEF]
      4808264h R     W_INTERNAL      fixx [0000] ;rx_addr_1 (usually "rxtx_addr-x")
      4808268h R     W_RXTX_ADDR     fixx [0005] ;rxtx_addr
      4808270h R     W_INTERNAL      fixx [0000] ;rx_addr_2 (usually "rx_addr_1-1")
      4808274h ?     W_INTERNAL      fixx [ 0001]
      4808278h R/W   W_INTERNAL      ffff [000F]
      480827Ch ?     W_INTERNAL      fixx [ 000A]
      4808290h (R/W) W_X_290h        fixx [FFFF] bit 0 = ? (used by firmware part4)
      4808298h W     W_INTERNAL      fixx [0000]
      48082A0h R/W   W_INTERNAL      ffff [0000]
      48082A2h R     W_INTERNAL      XXXX [7FFF] 15bit shift reg (used during tx?)
      48082A4h R     W_INTERNAL      fixx [0000] ;rx_rate_1 not ALWAYS same as 2C4h
      48082A8h W     W_INTERNAL      fixx [0000]
      48082ACh ?     W_INTERNAL      fixx [ 0038]
      48082B0h W     W_INTERNAL      fixx [0000]
      48082B4h R/W   W_INTERNAL      -1-3 [0000]
      48082B8h ?     W_INTERNAL      fixx [0000]
      48082C0h R/W   W_INTERNAL      ---1 [0000]
      48082C4h R     W_INTERNAL      fixx [000A] ;rx_rate_2 (0Ah,14h = 1,2 Mbit/s)
      48082C8h R     W_INTERNAL      fixx [0000] ;rx_duration/length/rate (or so?)
      48082CCh R     W_INTERNAL      fixx [0000] ;rx_framecontrol; from ieee header
      48082D0h DIS   W_INTERNAL                  ;"W_POWERACK" (internal garbage)
                                                 ;normally DISABLED (unless FORCE)
      48082F0h R/W   W_INTERNAL      ffff [0000]
      48082F2h R/W   W_INTERNAL      ffff [0000]
      48082F4h R/W   W_INTERNAL      ffff [0000]
      48082F6h R/W   W_INTERNAL      ffff [0000]

All other ports in range 4808000h..4808FFFh are unused.
All registers marked as "W_INTERNAL" aren't used by Firmware part4, and are probably unimportant, except for whatever special diagnostics purposes.
Reading from write-only ports (W) often mirrors to data from other ports.
Additionally, there are 69h Baseband Chip Registers (BB), and 0Fh RF Chip Registers (see BB and RF chapters).
For Wifi Power Managment (POWCNT2), for Wifi Waitstates (WIFIWAITCNT), see:
DS Power Control
For the Power LED Blink Feature (conventionally used to indicate Wifi activity) see:
DS Power Management Device
For Wifi Configuration and Calibration data in Firmware Header, see:
DS Cartridges, Encryption, Firmware
Wifi RAM - NDS7 - Memory (4804000h..4805FFFh)

      4804000h W_MACMEM RX/TX Buffers (2000h bytes) (excluding below specials)
      4805F60h Used for something, not included in the rx circular buffer.
      4805F80h W_WEPKEY_0 (32 bytes)
      4805FA0h W_WEPKEY_1 (32 bytes)
      4805FC0h W_WEPKEY_2 (32 bytes)
      4805FE0h W_WEPKEY_3 (32 bytes)

Unlike all other NDS memory, Wifi RAM is left uninitialized after boot.
5F80h - W_WEPKEY_0 thru W_WEPKEY_3 - Wifi WEP keys (R/W)
These WEP key slots store the WEP keys that are used for encryption for 802.11 keys IDs 0-3.

DS Wifi Control

4808000h - W_ID - Wifi Chip ID (R)

      0-15   Chip ID (1440h on NDS, C340h on NDS-lite)

The NDS-lite is more or less backwards compatible with the original NDS (the W_RXBUF_GAPDISP and W_TXBUF_GAPDISP are different, and most of the garbage effects on unused/mirrored ports are different, too).
4808004h - W_MODE_RST - Wifi Hardware mode / reset (R/W)

      0     Adjust some ports (0/1=see lists below) (R/W)
            TX Master Enable for LOC1..3 and Beacon  (0=Disable, 1=Enable)
      1-12  Unknown (R/W)
      13    Reset some ports (0=No change, 1=Reset/see list below) (Write-Only)
      14    Reset some ports (0=No change, 1=Reset/see list below) (Write-Only)
      15    Unknown (R/W)

4808006h - W_MODE_WEP - Wifi Software mode / Wep mode (R/W)

      0-2   Unknown, specify a software mode for wifi operation
            (may be related to hardware but a correlation has not yet been found)
      3-5   WEP Encryption Key Size:
             0=Reserved (acts same as 1)
             1=64bit WEP  (IV=24bit + KEY=40bit)  (aka 3+5 bytes)   ;standard/us
             2=128bit WEP (IV=24bit + KEY=104bit) (aka 3+13 bytes)  ;standard/world
             3=152bit WEP (IV=24bit + KEY=128bit) (aka 3+16 bytes)  ;uncommon
             4=Unknown, mabye 256bit WEP (IV=24bit + KEY=232bit) (aka 3+29 bytes)?
             5=Reserved (acts same as 1)
             6=Reserved (acts same as 1)
             7=Reserved (acts same as 1)
      6     Unknown
      8-15  Always zero

4808018h - W_MACADDR_0 - MAC Address (R/W)
480801Ah - W_MACADDR_1 - MAC Address (R/W)
480801Ch - W_MACADDR_2 - MAC Address (R/W)
48bit MAC Address of the console. Should be initialized from firmware[036h]. The hardware receives only packets that are sent to this address (or to group addresses, like FF:FF:FF:FF:FF:FF).
4808020h - W_BSSID_0 - BSSID (R/W)
4808022h - W_BSSID_1 - BSSID (R/W)
4808024h - W_BSSID_2 - BSSID (R/W)
48bit BSSID stored here. Ie. the MAC address of the host, obtained from Beacon frames (on the host itself, that should be just same as W_MACADDR). See W_RXFILTER.
4808028h - W_AID_LOW (R/W)

      Bit0-3   Maybe player-number, assuming that HW supports such? (1..15, or 0)
      Bit4-15  Not used

Usually set equal to the lower 4bit of the W_AID_FULL value.
480802Ah - W_AID_FULL - Association ID (R/W)

      Bit0-10  Association ID (AID) (1..2007, or zero)
      Bit11-15 Not used

4808032h - W_WEP_CNT - WEP Engine Enable (R/W)

      0-14  Unknown (usually zero)
      15    WEP Engine Enable  (0=Disable, 1=Enable)

Normally, bit15 should be always set (but it will only affect WEP-encrypted packets, ie. packets with Frame Control bit14=1 in 802.11 header). When disabled, WEP packets aren't received at all (neither in encrypted nor decrypted form), and sending WEP packets might be also ignored(?).
The firmware contains some code that does toggle the bit off for a moment (apparently to reset something after transfer errors).
4808044h - W_RANDOM - Random Generator (R)

      0-10  Random
      11-15 Not used (zero)

The random generator is updated at 33.51MHz rate, as such:

      X = (X AND 1) XOR (X ROL 1)  ;(rotation within 11bit range)

That random sequence goes through 5FDh different values before it restarts.
When reading from the random register, the old latched value is returned to the CPU, and the new current random value is then latched, so reads always return the older value, timed from the previous read.
Occassionally, about once every some thousand reads, the latching appears to occur 4 cycles earlier than normally, so the value on the next read will be 4 cycles older than expected.
The random register has ACTIVE mirrors.
48080BCh - W_PREAMBLE - Preamble Control (R/W)

      Bit   Dir  Expl.
      0     R/W  Unknown                    (this does NOT affect TX)
      1     R/W  Preamble (0=Long, 1=Short) (this does NOT affect TX)
      2     W    Preamble (0=Long, 1=Short) (this does affect TX) (only at 2Mbit/s)
      3-15  -    Always zero

Short preamble works only with 2Mbit/s transfer rate (ie. when set like so in TX hardware header). 1Mbit/s rate always uses long preamble.

      Type   Carrier Signal  SFD Value     PLCP Header     Data
      Long   128bit, 1Mbit   16bit, 1Mbit  48bit, 1Mbit    N bits, 1Mbit or 2Mbit
      Short  56bit, 1Mbit    16bit, 1Mbit  48bit, 2Mbit    N bits, 2Mbit

Length of the Carrier+SFD+PLCP part is thus 192us (long) or 96us (short).
Note: The Carrier+SFD+PLCP part is sent between IRQ14 and IRQ07 (not between IRQ07 and IRQ01).
Writing "0-then-1" to W_MODE_RST.Bit0 does reset following ports:

      [4808034h]=0002h ;W_INTERNAL
      [480819Ch]=0046h ;W_RF_PINS
      [4808214h]=0009h ;W_RF_STATUS
      [480827Ch]=0005h ;W_INTERNAL
      [48082A2h]=?     ;...unstable?

Writing "1-then-0" to W_MODE_RST.Bit0 does reset following ports:

      [480827Ch]=000Ah ;W_INTERNAL

Writing "1" to W_MODE_RST.Bit13 does reset following ports:

      [4808056h]=0000h ;W_RXBUF_WR_ADDR
      [48080C0h]=0000h ;W_CMD_TOTALTIME
      [48080C4h]=0000h ;W_CMD_REPLYTIME
      [48081A4h]=0000h ;W_X_1A4h
      [4808278h]=000Fh ;W_INTERNAL
      ...Also, following may be affected (results are unstable though)...
      [48080AEh]=?     ;or rather the actual port (which it is an mirror of)
      [48080BAh]=?     ;W_INTERNAL (occassionally unstable)
      [4808204h]=?     ;W_INTERNAL
      [480825Ch]=?     ;W_INTERNAL
      [4808268h]=?     ;W_RXTX_ADDR
      [4808274h]=?     ;W_INTERNAL

Writing "1" to W_MODE_RST.Bit14 does reset following ports:

      [4808006h]=0000h ;W_MODE_WEP
      [4808008h]=0000h ;W_TXSTATCNT
      [480800Ah]=0000h ;W_X_00Ah
      [4808018h]=0000h ;W_MACADDR_0
      [480801Ah]=0000h ;W_MACADDR_1
      [480801Ch]=0000h ;W_MACADDR_2
      [4808020h]=0000h ;W_BSSID_0
      [4808022h]=0000h ;W_BSSID_1
      [4808024h]=0000h ;W_BSSID_2
      [4808028h]=0000h ;W_AID_LOW
      [480802Ah]=0000h ;W_AID_FULL
      [480802Ch]=0707h ;W_TX_RETRYLIMIT
      [480802Eh]=0000h ;W_INTERNAL
      [4808050h]=4000h ;W_RXBUF_BEGIN
      [4808052h]=4800h ;W_RXBUF_END
      [4808084h]=0000h ;W_TXBUF_TIM
      [48080BCh]=0001h ;W_PREAMBLE
      [48080D0h]=0401h ;W_RXFILTER
      [48080D4h]=0001h ;W_CONFIG_0D4h
      [48080E0h]=0008h ;W_RXFILTER2
      [48080ECh]=3F03h ;W_CONFIG_0ECh
      [4808194h]=0000h ;W_TX_HDR_CNT
      [4808198h]=0000h ;W_INTERNAL
      [48081A2h]=0001h ;W_X_1A2h
      [4808224h]=0003h ;W_INTERNAL
      [4808230h]=0047h ;W_INTERNAL

DS Wifi Interrupts

4808010h - W_IF - Wifi Interrupt Request Flags (R/W)

      0   Receive Complete  (packet received and stored in the RX fifo)
      1   Transmit Complete (packet is done being transmitted) (no matter if error)
      2   Receive Event Increment      (IRQ02, see W_RXSTAT_INC_IE)
      3   Transmit Error Increment     (IRQ03, see W_TX_ERR_COUNT)
      4   Receive Event Half-Overflow  (IRQ04, see W_RXSTAT_OVF_IE)
      5   Transmit Error Half-Overflow (IRQ05, see W_TX_ERR_COUNT.Bit7)
      6   Start Receive     (IRQ06, a packet has just started to be received)
      7   Start Transmit    (IRQ07, a packet has just started to be transmitted)
      8   Txbuf Count Expired  (IRQ08, see W_TXBUF_COUNT)
      9   Rxbuf Count Expired  (IRQ09, see W_RXBUF_COUNT)
      10  Not used (always zero, even when trying to set it with W_IF_SET)
      11  RF Wakeup            (IRQ11, see W_POWERSTATE)
      12  Multiplay ...?       (IRQ12, see W_CMD_COUNT)
      13  Post-Beacon Timeslot (IRQ13, see W_BEACONCOUNT2)
      14  Beacon Timeslot      (IRQ14, see W_BEACONCOUNT1/W_US_COMPARE)
      15  Pre-Beacon Timeslot  (IRQ15, see W_BEACONCOUNT1/W_PRE_BEACON)

Write a '1' to a bit to clear it. For the Half-Overflow flags that works ONLY if the counter MSBs are zero (ie. one must first read the counters (to reset them), and THEN acknowledge the corresponding W_IF bit).
The Transmit Start/Complete bits (Bit7,1) are set for EACH packet (including beacons, and including retries).
4808012h - W_IE - Wifi Interrupt Enable Flags (R/W)

      0-15  Enable Flags, same bits as W_IF  (0=Disable, 1=Enable)

In W_IE, Bit10 is R/W, but seems to have no function since IRQ10 doesn't exist.
480821Ch - W_IF_SET (W_INTERNAL) - Force Wifi Interrupt Flags (W)

      0-15  Set corresponding bits in W_IF  (0=No change, 1=Set Bit)

Notes: Bit10 cannot be set since no IRQ10 exists. This register does only set IRQ flags, but without performing special actions (such like W_BEACONCOUNT1 and W_BEACONCOUNT2 reloads that occur on real IRQ14's).
Wifi Primary IRQ Flag (IF.Bit24, Port 4000214h)
IF.Bit24 gets set <only> when (W_IF AND W_IE) changes from 0000h to non-zero.
IF.Bit24 can be reset (ack) <even> when (W_IF AND W_IE) is still non-zero.

      Caution  Caution  Caution  Caution  Caution
      That means, when acknowledging IF.Bit24, then NO FURTHER wifi IRQs
      will be executed whilst and as long as (W_IF AND W_IE) is non-zero.

One work-around is to process/acknowledge ALL wifi IRQs in a loop, including further IRQs that may occur inside of that loop, until (W_IF AND W_IE) becomes 0000h.
Another work-around (for single IRQs) would be to acknowledge IF and W_IF, and then to set W_IE temporarily to 0000h, and then back to the old W_IE setting.

DS Wifi Power-Down Registers

4808036h - W_POWER_US (R/W)

      0     Disable W_US_COUNT and W_BB_ports  (0=Enable, 1=Disable)
      1     Unknown (usually 0)
      2-15  Always zero

Bit0=0 enables RFU by setting RFU.Pin11=HIGH, which activates the 22.000MHz oscillator on the RFU board, the 22MHz clock is then output to RFU.Pin26.
4808038h - W_POWER_TX (R/W)
transmit-related power save or sth
init from firmware[05Ch]

      0     Auto Wakeup (1=Leave Idle Mode a while after IRQ15)
      1     Auto Sleep  (0=Enter Idle Mode on IRQ13)
      2     Unknown
      3     Unknown (Write-only) (used by firmware)
      4-15  Always zero

480803Ch - W_POWERSTATE (R/W)/(R)

      0     Unknown (usually 0)                         (R/W)
      1     Request Power Enable (0=No, 1=Yes/queued)   (R/W, but not always)
      2-7   Always zero
      8     Indicates that Bit9 is about the be cleared (Read only)
      9     Current power state (0=Enabled, 1=Disabled) (Read only)
      10-15 Always zero

[value =1: queue disable power state] ;<-- seems to be incorrect
[value =2: queue enable power state] ;<-- seems to be correct
Enabling causes wakeup interrupt (IRQ11).
Note: That queue stuff seems to work only if W_POWER_US=0 and W_MODE_RST=1.
4808040h - W_POWERFORCE - Force Power State (R/W)

      0     New value for W_POWERSTATE.Bit9  (0=Clear/Delayed, 1=Set/Immediately)
      1-14  Always zero
      15    Apply Bit0 to W_POWERSTATE.Bit9  (0=No, 1=Yes)

Setting W_POWERFORCE=8001h whilst W_POWERSTATE.Bit9=0 acts immediately:

      (Doing this is okay. Switches to power down mode. Similar to IRQ13.)
      [4808034h]=0002h ;W_INTERNAL
      [480803Ch]=02xxh ;W_POWERSTATE
      [48080B0h]=0000h ;W_TXREQ_READ
      [480819Ch]=0046h ;W_RF_PINS
      [4808214h]=0009h ;W_RF_STATUS (idle)

Setting W_POWERFORCE=8000h whilst W_POWERSTATE.Bit9=1 acts delayed:

      (Don't do this. After that sequence, the hardware seems to be messed up)
      W_POWERSTATE.Bit8 gets set to indicate the pending operation,
      while pending, changes to W_POWERFORCE aren't applied to W_POWERSTATE,
      while pending, W_POWERACK becomes Read/Write-able,
      writing 0000h to W_POWERACK does clear W_POWERSTATE.Bit8,
      and does apply POWERFORCE.Bit0 to W_POWERSTATE.Bit9
      and does deactivate Port W_POWERACK again.

4808048h - W_POWER_? (R/W)

      0     Unknown
      1     Unknown
      2-15  Always zero

At whatever time (during transmit or so) it gets set to 0003h by hardware.
See also: POWCNT2, W_BB_POWER.

DS Wifi Receive Control

4808030h - W_RXCNT - Wifi Receive Control (parts R/W and W)

      0     Copy W_RXBUF_WR_ADDR to W_RXBUF_WRCSR                               (W)
      1-3   Unknown                                                           (R/W)
      4-6   Always zero
      7     Copy W_TXBUF_REPLY1 to W_TXBUF_REPLY2, set W_TXBUF_REPLY1 to 0000h  (W)
      8-14  Unknown                                                           (R/W)
      15    Enable Queuing received data to RX FIFO                           (R/W)

48080D0h - W_RXFILTER - (R/W)

      0     (0=Insist on W_BSSID, 1=Accept no matter of W_BSSID)
      1-6   Unknown (usually zero)
      7     Unknown (0 or 1)
      8     Unknown (0 or 1)
      9     Unknown (0 or 1)
      10    Unknown (0 or 1)       (when set, receives beacons, and maybe others)
      11    Unknown (usually zero)     ;reportedly "allow toDS" ?
      12    (0=Normal, 1=Accept even whatever garbage)
      13-15 Not used (always zero)

Specifies what packets to allow.
0000h = Disable receive.
FFFFh = Enable receive.
0400h = Receives managment frames (and possibly others, too)
48080E0h - W_RXFILTER2 - (R/W)

      0     Unknown (0=Receive Data Frames, 1=Ignore Data Frames) (?)
      1     Unknown
      2     Unknown
      3     Unknown (usually set)
      4-15  Not used (always zero)

Firmware writes values 08h, 0Bh, 0Dh (aka 1000b, 1011b, 1101b).
Firmware usually has bit0 set, even when receiving data frames, so, in some situations data frames seem to pass-through even when bit0 is set...? Possibly that situation is when W_BSSID matches...?
Control/PS-Poll frames seem to be passed always (even if W_RXFILTER2=0Fh).

DS Wifi Receive Buffer

The dimensions of the circular Buffer are set with BEGIN/END values, hardware automatically wraps to BEGIN when an incremented pointer hits END address.
Write Area
Memory between WRCSR and READCSR is free for receiving data, the hardware writes incoming packets to this region (to WRCSR and up) (but without exceeding READCSR), once when it has successfully received a complete packet, the hardware moves WRCSR after the packet (aligned to a 4-byte boundary).
Read Area
Memory between READCSR and WRCSR contains received data, which can be read by the CPU via RD_ADDR and RD_DATA registers (or directly from memory). Once when having processed that data, the CPU must set READCSR to the end of it.
4808050h - W_RXBUF_BEGIN - Wifi RX Fifo start location (R/W)
4808052h - W_RXBUF_END - Wifi RX Fifo end location (R/W)

      0-15  Byte-offset in Wifi Memory (usually 4000h..5FFEh)

Although the full 16bit are R/W, only the 12bit halfword offset in Bit1-12 is actually used, the other bits seem to have no effect.
Some or all (?) of the below incrementing registers are automatically matched to begin/end, that is, after incrementing, IF adr=end THEN adr=begin.
4808054h - W_RXBUF_WRCSR - Wifi RX Fifo Write or "end" cursor (R)

      0-11  Halfword Address in RAM
      12-15 Always zero

This is a hardware controlled write location - it shows where the next packet will be written..
4808056h - W_RXBUF_WR_ADDR - Wifi RX Fifo Write Cursor Latch value (R/W)

      0-11  Halfword Address in RAM
      12-15 Always zero

This is a value that is latched into W_RXBUF_WRCSR, when the W_RXCNT latch bit (W_RXCNT.Bit0) is written.
4808058h - W_RXBUF_RD_ADDR - Wifi CircBuf Read Address (R/W)

      0     Always zero
      1-12  Halfword Address in RAM for reading via W_RXBUF_RD_DATA
      13-15 Always zero

The circular buffer limits are the same as the range specified for the receive FIFO, however the address can be set outside of that range and will only be affected by the FIFO boundary if it crosses the FIFO end location by reading from the circular buffer.
480805Ah - W_RXBUF_READCSR - Wifi RX Fifo Read or "start" cursor (R/W)

      0-11  Halfword Address in RAM
      12-15 Always zero

This value is specified the same as W_RXBUF_WRCSR - it's purely software controlled so it's up to the programmer to move the start cursor after loading a packet. If W_RXBUF_READCSR != W_RXBUF_WRCSR, then one or more packets exist in the FIFO that need to be processed (see the section on HW RX Headers, for information on calculating packet lengths). Once a packet has been processed, the software should advance the read cursor to the beginning of the next packet.
4808060h - W_RXBUF_RD_DATA - Wifi CircBuf Read Data (R)

      0-15  Data

returns the 16bit value at the address specified by W_RXBUF_RD_ADDR, and increments W_RXBUF_RD_ADDR by 2. If the increment causes W_RXBUF_RD_ADDR to equal the address specified in W_RXBUF_END, W_RXBUF_RD_ADDR will be reset to the address specified in W_RXBUF_BEGIN.
Ports 1060h, 6060h, 7060h are PASSIVE mirrors of 0060h, reading from these mirrors returns the old latched value from previous read from 0060h, but without reading a new value from RAM, and without incrementing the address.
4808062h - W_RXBUF_GAP - Wifi RX Gap Address (R/W)

      0     Always zero
      1-12  Halfword Address in RAM
      13-15 Always zero

Seems to be intended to define a "gap" in the circular buffer, done like so:

      Addr=Addr+2 and 1FFEh  ;address increment (by W_RXBUF_RD_DATA read)
      if Addr=RXBUF_END then ;normal begin/end wrapping (done before gap wraps)
         Addr=RXBUF_BEGIN
      if Addr=RXBUF_GAP then ;now gap-wrap (may include further begin/end wrap)
         Addr=RXBUF_GAP+RXBUF_GAPDISP*2
         if Addr>=RXBUF_END then Addr=Addr+RXBUF_BEGIN-RXBUF_END  ;wrap more

To disable the gap stuff, set both W_RXBUF_GAP and W_RXBUF_GAPDISP to zero.
4808064h - W_RXBUF_GAPDISP - Wifi RX Gap Displacement Offset (R/W)

      0-11  Halfword Offset, used with W_RXBUF_GAP (see there)
      12-15 Always zero

Caution: On the DS-Lite, after adding it to W_RXBUF_RD_ADDR, the W_RXBUF_GAPDISP setting is destroyed (reset to 0000h) by hardware. The original DS leaves W_RXBUF_GAPDISP intact.
480805Ch - W_RXBUF_COUNT (R/W)

      0-11  Decremented on reads from W_RXBUF_RD_DATA
      12-15 Always zero

Triggers IRQ09 when it reaches zero, and does then stay at zero (without further decrementing, and without generating further IRQs).
Note: Also decremented on (accidental) writes to read-only W_RXBUF_RD_DATA.

DS Wifi Receive Statistics

48081A8h - W_RXSTAT_INC_IF - Statistics Increment Flags (R)

      0-12   Increment Flags (see Port 48081B0h..1BFh)
      13-15  Always zero

Bitmask for which statistics have been increased at least once.
Unknown how to reset/acknowledge these bits... possibly by reading from 48081A8h, or by reading from 48081B0h..1BFh, or eventually/obscurely by writing to 48081ACh.
48081AAh - W_RXSTAT_INC_IE - Statistics Increment Interrupt Enable (R/W)

      0-12   Counter Increment Interrupt Enable (see 48081B0h..1BFh) (1=Enable)
      13-15  Unknown (usually zero)

Statistic Interrupt Enable Control register for Count Up.
Note: ------> seems to trigger IRQ02 ...?
48081ACh - W_RXSTAT_OVF_IF - Statistics Half-Overflow Flags (R)

      0-12   Half-Overflow Flags (see Port 48081B0h..1BFh)
      13-15  Always zero

The W_RXSTAT_OVF_IF bits are simply containing the current bit7-value of the corresponding counters, setting or clearing that counter bits is directly reflected to W_RXSTAT_OVF_IF.
The recommended way to acknowledge W_RXSTAT_OVF_IF is to read the corresponding counters (which are reset to 00h after reading). For some reason, the firmware is additionally writing FFFFh to W_RXSTAT_OVF_IF (that is possibly a bug, or it does acknowledge something internally?).
48081AEh - W_RXSTAT_OVF_IE - Statistics Half-Overflow Interrupt Enable (R/W)

      0-12   Half-Overflow Interrupt Enable (see Port 48081B0h..1BFh) (1=Enable)
      13-15  Unknown (usually zero)

Statistic Interrupt Enable for Overflow, bits same as in W_RXSTAT_INC_IE
Note: ------> seems to trigger IRQ04 ...?
48081B0h..1BFh - W_RXSTAT - Receive Statistics (R/W, except 1B5h: Read-only)
W_RXSTAT is a collection of 8bit counters, which are incremented upon certain events. These entries are automatically reset to 0000h after reading. Should be accessed with LDRH opcodes (using LDRB to read only 8bits does work, but the read is internally expanded to 16bit, and so, the whole 16bit value will be reset to 0000h).

      Port      Dir  Bit  Expl.
      48081B0h  R/W  0    W_RXSTAT  ?
      48081B1h  -    -    Always 0  -
      48081B2h  R/W  1    W_RXSTAT  ?    "RX_RateErrorCount"
      48081B3h  R/W  2    W_RXSTAT  Length>2348 error
      48081B4h  R/W  3    W_RXSTAT  RXBUF Full error
      48081B5h  R    4?   W_RXSTAT  ?    (R) (but seems to exist; used by firmware)
      48081B6h  R/W  5    W_RXSTAT  Length=0 or Wrong FCS Error
      48081B7h  R/W  6    W_RXSTAT  Packet Received Okay
                                 (also increments on W_MACADDR mis-match)
                                 (also increments on internal ACK packets)
                                 (also increments on invalid IEEE type=3)
                                 (also increments TOGETHER with 1BCh and 1BEh)
                                 (not incremented on RXBUF_FULL error)
      48081B8h  R/W  7    W_RXSTAT  ?
      48081B9h  -    -    Always 0  -
      48081BAh  R/W  8    W_RXSTAT  ?
      48081BBh  -    -    Always 0  -
      48081BCh  R/W  9    W_RXSTAT  WEP Error (when FC.Bit14 is set)
      48081BDh  R/W  10   W_RXSTAT  ?
      48081BEh  R/W  11   W_RXSTAT  (duplicated sequence control)
      48081BFh  R/W  12   W_RXSTAT  ?

48081C4h - W_RX_COUNT (W_INTERNAL) (R)

      0-?   Receive Okay Count (increments together with ports 48081B4h, 48081B7h)
      8-?   Receive Error Count (increments together with ports 48081B3h, 48081B6h)

Increments when receiving a packet. Automatically reset to zero after reading.
48081D0h..1DFh - W_CMD_STAT - Multiplay Response Error Counters (R/W)
The multiplay error counters are only used when sending a multiplay command (via W_TXBUF_CMD) to any connected slaves (which must be indicated by flags located in the second halfword of the multiplay command's frame body).

      48081D0h        Not used (always zero)
      48081D1h..1DFh  Client 1..15 Response Error (increments on missing replies)

If one or more of those slaves fail to respond, then the corresponding error counters get incremented (at the master side). Automatically reset to zero after reading.
Unknown if these counters do also increment at the slave side?

DS Wifi Transmit Control

48080ACh - W_TXREQ_RESET - Reset Transfer Request Bits (W)

      0-3   Reset corresponding bits in W_TXREQ_READ (0=No change, 1=Reset)
      4-15  Unknown (if any)

Firmware writes values 01h,02h,08h,0Dh, and FFFFh.
48080AEh - W_TXREQ_SET - Set Transfer Request Bits (W)

      0-3   Set corresponding bits in W_TXREQ_READ   (0=No change, 1=Set)
      4-15  Unknown (if any)

Firmware writes values 01h,02h,05h,08h,0Dh.
48080B0h - W_TXREQ_READ - Get Transfer Request Bits (R)

      0     Send W_TXBUF_LOC1  (1=Transfer, if enabled in W_TXBUF_LOC1.Bit15)
      1     Send W_TXBUF_CMD   (1=Transfer, if enabled in W_TXBUF_CMD.Bit15)
      2     Send W_TXBUF_LOC2  (1=Transfer, if enabled in W_TXBUF_LOC2.Bit15)
      3     Send W_TXBUF_LOC3  (1=Transfer, if enabled in W_TXBUF_LOC3.Bit15)
      4     Unknown (Beacon?)  (always 1, except when cleared via W_POWERFORCE)
      5-15  Unknown/Not used

Bit0-3 can be set/reset via W_TXREQ_SET/W_TXREQ_RESET. The setting in W_TXREQ_READ remains intact even after the transfer(s) have completed.
If more than one of the LOC1,2,3 bits is set, then LOC3 is transferred first, LOC1 last.
Beacons are transferred in every Beacon Timeslot (if enabled in W_TXBUF_BEACON.Bit15).
Bit0,2,3 are automatically reset upon IRQ14 (by hardware).
48080B6h - W_TXBUSY (R)

      0     W_TXBUF_LOC1  (1=Requested Transfer busy, or not yet started at all)
      1     W_TXBUF_CMD   (1=Requested Transfer busy, or not yet started at all)
      2     W_TXBUF_LOC2  (1=Requested Transfer busy, or not yet started at all)
      3     W_TXBUF_LOC3  (1=Requested Transfer busy, or not yet started at all)
      4     W_TXBUF_BEACON  (1=Beacon Transfer busy)
      5-15  Unknown (if any)

Busy bits. If all three W_TXBUF_LOC's are sent, then it goes through values 0Dh,05h,01h,00h; ie. LOC3 is transferred first, LOC1 last. The register is updated upon IRQ01 (by hardware).
Bit4 is set only in Beacon Timeslots.
48080B8h - W_TXSTAT - RESULT - Status of transmitted frame (R)
For LOC1-3, this register is updated at the end of a transfer (upon the IRQ01 request), if retries occur then it is updated only after the final retry.
For BEACON, this register is updated only if enabled in W_TXSTATCNT.Bit15, and only after successful transfers (since beacon errors result in infinite retries).
For CMD, this register is updated only if enabled in W_TXSTATCNT.Bit13,14).
Bit0/1 act similar to W_IF Bit1/3, however, the W_IF Bits are set after each transmit (including retries).

      0     One (or more) Packet has Completed (1=Yes)
            (No matter if successful, for that info see Bit1)
            (No matter if ALL packets are done, for that info see Bit12-13)
      1     Packet Failed (1=Error)
      2-7   Unknown/Not used
      8-11  Usually 0, ...but firmware is checking for values 03h,08h,0Bh
            (gets set to 07h when transferred W_TXBUF_LOC1/2/3 did have Bit12=set)
            (gets set to 00h otherwise)
            (gets set to 03h after beacons; if enabled in W_TXSTATCNT.Bit15)
            (gets set to 08h or 0Bh after CMD; depending on W_TXSTATCNT.Bit13,14)
      12-13 Packet which has updated W_TXSTAT (0=LOC1/BEACON/CMD, 1=LOC2, 2=LOC3)
      14-15 Unknown/Not used

No idea how to reset bit0/1 once when they are set?
4808008h - W_TXSTATCNT (R/W)

      0-12  Unknown (usually zero)
      13    Update W_TXSTAT=0B01h and trigger IRQ01 after CMD transmits    (1=Yes)
      14    Update W_TXSTAT=0800h and trigger IRQ01 after CMD transmits    (1=Yes)
      15    Update W_TXSTAT and trigger IRQ01 after BEACON transmits (0=No, 1=Yes)

If both Bit13 and Bit14 are set, then Bit13 is having priority.
Note: LOC1..3 transmits are always updating W_TXSTAT and triggering IRQ01.
4808194h - W_TX_HDR_CNT - Disable Transmit Header Adjustments (R/W)

      0     IEEE FC.Bit12 and Duration (0=Auto/whatever, 1=Manual/Wifi RAM)
      1     IEEE Frame Check Sequence  (0=Auto/FCS/CRC32, 1=Manual/Wifi RAM)
      2     IEEE Sequence Control      (0=Auto/W_TX_SEQNO, 1=Manual/Wifi RAM)
      3-15  Always zero

Allows to disable automatic adjustments of the IEEE header and checksum.
Note: W_TX_SEQNO can be also disabled by W_TXBUF_LOCn.Bit13 and by TXHDR[04h].
4808210h - W_TX_SEQNO - Transmit Sequence Number (R)

      0-11   Increments on IRQ07 (Transmit Start Interrupt)
      12-15  Always zero

Also incremented shortly after IRQ12.
When enabled in W_TXBUF_LOCn.Bit13, this value replaces the upper 12bit of the IEEE Frame Header's Sequence Control value (otherwise, when disabled, the original value in Wifi RAM is used, and, in that case, W_TX_SEQNO is NOT incremented).
Aside from W_TXBUF_LOCn.Bit13, other ways to disable W_TX_SEQNO are: Transmit Hardware Header entry TXHDR[04h], and W_TX_HDR_CNT.Bit2.

DS Wifi Transmit Buffers

4808068h - W_TXBUF_WR_ADDR - Wifi CircBuf Write Address (R/W)

      0     Always zero
      1-12  Halfword Address in RAM for Writes via W_TXBUF_WR_DATA
      13-15 Always zero

4808070h - W_TXBUF_WR_DATA - Wifi CircBuf Write Data (W)

      0-15  Data to be written to address specified in W_TXBUF_WR_ADDR

After writing to this register, W_TXBUF_WR_ADDR is automatically incremented by 2, and, if it gets equal to W_TXBUF_GAP, then it gets additonally incremented by W_TXBUF_GAPDISP*2.
4808074h - W_TXBUF_GAP - Wifi CircBuf Write Top (R/W)

      0     Always zero
      1-12  Halfword Address
      13-15 Always zero

4808076h - W_TXBUF_GAPDISP - CircBuf Write Offset from Top to Bottom (R/W)

      0-11  Halfword Offset (added to; if equal to W_TXBUF_GAP)
      12-15 Always zero

Should be "0-write_buffer_size" (wrap from end to begin), or zero (no wrapping).
Caution: On the DS-Lite, after adding it to W_TXBUF_WR_ADDR, the W_TXBUF_GAPDISP setting is destroyed (reset to 0000h) by hardware. The original DS leaves W_TXBUF_GAPDISP intact.
Note: W_TXBUF_GAP and W_TXBUF_GAPDISP may be (not TOO probably) also used by transmits via W_TXBUF_LOCn and W_TXBUF_BEACON (not tested).
4808080h - W_TXBUF_BEACON - Beacon Transmit Location (R/W)
4808090h - W_TXBUF_CMD - Multiplay Command Transmit Location (R/W)
48080A0h - W_TXBUF_LOC1 - Transmit location 1 (R/W)
48080A4h - W_TXBUF_LOC2 - Transmit location 2 (R/W)
48080A8h - W_TXBUF_LOC3 - Transmit location 3 (R/W)

      0-11  Halfword Address of TX Frame Header in RAM
      12    For LOC1-3: When set, W_TXSTAT.bit8-10 are set to 07h after transfer
                        And, when set, the transferred frame-body gets messed up?
            For BEACON: Unknown, no effect on W_TXSTAT
            For CMD: Unknown, no effect on W_TXSTAT
      13    IEEE Sequence Control (0=From W_TX_SEQNO, 1=Value in Wifi RAM)
            For BEACON: Unknown (always uses W_TX_SEQNO) (no matter of bit13)
      14    Unknown
      15    Transfer Request (1=Request/Pending)

For LOC1..3 and CMD, Bit15 is automatically cleared after (or rather: during?) transfer (no matter if the transfer was successful). For Beacons, bit15 is kept unchanged since beacons are intended to be transferred repeatedly.
The purpose of W_TXBUF_CMD is unknown... maybe for automatic replies...? Pictochat seems to use it for host-to-client data frames. W_TXBUF_CMD.Bit15 can be set ONLY while W_CMD_COUNT is non-zero.
48080B4h - W_TXBUF_RESET (W)

      0     Disable LOC1    (0=No change, 1=Reset W_TXBUF_LOC1.Bit15)
      1     Disable CMD     (0=No change, 1=Reset W_TXBUF_CMD.Bit15)
      2     Disable LOC2    (0=No change, 1=Reset W_TXBUF_LOC2.Bit15)
      3     Disable LOC3    (0=No change, 1=Reset W_TXBUF_LOC3.Bit15)
      4-5   Unknown/Not used
      6     Disable REPLY2  (0=No change, 1=Reset W_TXBUF_REPLY2.Bit15)
      7     Disable REPLY1  (0=No change, 1=Reset W_TXBUF_REPLY1.Bit15)
      8-15  Unknown/Not used

Firmware writes values FFFFh, 40h, 02h, xxxx, 09h, 01h, 02h, C0h.
4808084h - W_TXBUF_TIM - Beacon TIM Index in Frame Body (R/W)

      0-7   Location of TIM parameters within Beacon Frame Body
      8-15  Not used/zero

Usually set to 15h, that assuming that preceding Frame Body content is: Timestamp(8), BeaconInterval(2), Capability(2), SuppRatesTagLenParams(4), ChannelTagLenParam(3), TimTagLen(2); so the value points to TimParams (ie. after TimTagLen).
480806Ch - W_TXBUF_COUNT (R/W)

      0-11  Decremented on writes to W_TXBUF_WR_DATA
      12-15 Always zero

Triggers IRQ08 when it reaches zero, and does then stay at zero (without further decrementing, and without generating further IRQs).
Note: Not affected by (accidental) reads from write-only W_TXBUF_WR_DATA.

DS Wifi Transmit Errors

Automatic ACKs
Transmit errors occur on missing ACKs. The NDS hardware is automatically responding with an ACK when receiving a packet (if it has been addressed to the receipients W_MACADDR setting). And, when sending a packet, the NDS hardware is automatically checking for ACK responses.
The only exception are packets that are sent to group addresses (ie. Bit0 of the 48bit MAC address being set to "1", eg. Beacons sent to FF:FF:FF:FF:FF:FF), the receipient(s) don't need to respond to such packets, and the sender always passes okay without checking for ACKs.
480802Ch - W_TX_RETRYLIMIT (R/W)
Specifies the maximum number of retries on Transmit Errors (eg. 07h means one initial transmit, plus up to 7 retries, ie. max 8 transmits in total).

      0-7   Retry Count (usually 07h)
      8-15  Unknown     (usually 07h)

The Retry Count value is decremented on each Error (unless it is already 00h). There's no automatic reload, so W_TX_RETRYLIMIT should be reinitialized by software prior to each transmit (or, actually, there IS a reload?).
When sending multiple packets (by setting more than one bit with W_TXREQ_SET), then the first packet may eat-up all retries, leaving only a single try to the other packet(s).
48081C0h - W_TX_ERR_COUNT - TransmitErrorCount (R/W)

      0-7   TransmitErrorCount
      8-15  Always zero

Increments on Transmit Errors. Automatically reset to zero after reading.
IRQ03 triggered when W_TX_ERR_COUNT is incremented (for NON-beacons ONLY).
IRQ05 triggered when W_TX_ERR_COUNT > 7Fh (happens INCLUDING for beacons).
Error Notification
Transmit Errors can be sensed via W_TX_ERR_COUNT, IRQ03, IRQ05, TX Hardware Header entry [00h], and W_TXSTAT.Bit1.
W_TXBUF_BEACON Errors
As the name says, W_TXBUF_BEACON is intended for sending Beacons to group addresses (which do not require to respond by ACKs). So, transmit errors would occur only when mis-using W_TXBUF_BEACON to send packets to individual addresses, but the W_TXBUF_BEACON error handling isn't fully implemented:
First of, W_TX_RETRYLIMIT isn't used, instead, W_TXBUF_BEACON errors will result in infinite retries.
Moreover, W_TXBUF_BEACON errors seem to increment W_TX_ERR_COUNT, but without generating IRQ03, however, IRQ05 is generated when W_TX_ERR_COUNT>7Fh.
Other Errors
The NDS transmit hardware seems to do little error checking on the packet headers. The only known error-checked part is byte [04h] in the TX hardware header (which must be 00h, 01h, or 02h). Aside from that, when sent to a group address, it is passing okay even with invalid IEEE type/subtypes, and even with Length/Rate entries set to zero. However, when sending such data to an individual address, the receiving NDS won't respond by ACKs.
Note
Received ACKs aren't stored in WifiRAM (or, possibly, they ARE stored, but without advancing W_RXBUF_WRCSR, so that the software won't see them, and so that they will be overwritten by the next packet).

DS Wifi Status

480819Ch - W_RF_PINS - Status of RF-Chip Control Signals (R)

      0    Reportedly "carrier sense" (maybe 1 during RX.DTA?) (usually 0)
      1    TX.MAIN (RFU.Pin17) Transmit Data Phase          (0=No, 1=Active)
      2    Unknown (RFU.Pin3)  Seems to be always high      (Always 1=high?)
      3-5  Not used                                         (Always zero)
      6    TX.ON   (RFU.Pin14) Transmit Preamble+Data Phase (0=No, 1=Active)
             Uhhh, no that seems to be still wrong...
             Bit6 is often set, even when not transmitting anything...
      7    RX.ON   (RFU.Pin15) Receive Mode                 (0=No, 1=Enable)
      8-15 Not used                                         (Always zero)

Physical state of the RFU board's RX/TX pins. Similar to W_RF_STATUS.
4808214h - W_RF_STATUS - Current Transmit/Receive State (R)

      0-3  Current Transmit/Receive State:
            0 = Initial Value on power-up (before raising W_MODE_RST.Bit0)
            1 = RX Mode enabled (waiting for incoming data)
            2 = Switching from RX to TX (takes a few clock cycles)
            3 = TX Mode active  (sending preamble and data)
            4 = Switching from TX to RX (takes a few clock cycles)
            5 = Unknown, firmware checks for that value (maybe RX busy)
            6 = Unknown, firmware checks for that value (maybe RX busy)
            9 = Idle (upon IRQ13, and upon raising W_MODE_RST.Bit0)
            ----
            5 = Receive ACK phase ?
            6 =
            7 =
            8 = Multiplay related ? (when sending through W_TXBUF_CMD ?)
      4-15 Always zero?

Numeric Status Code. Similar to W_RF_PINS.
4808268h - W_RXTX_ADDR - Current Receive/Transmit Address (R)

      0-11   Halfword address
      12-15  Always zero

Indicates the halfword that is currently transmitted or received. Can be used by Start Receive IRQ06 handler to determine how many halfwords of the packet have been already received (allowing to pre-examine portions of the packet header even when the whole packet isn't fully received). Can be also used in Transmit Start IRQ07 handler to determine which packet is currently transmitted.

DS Wifi Timers

48080E8h - W_US_COUNTCNT - Microsecond counter enable (R/W)

      0     Counter Enable (0=Disable, 1=Enable)
      1-15  Always zero

Activates W_US_COUNT, and also W_BEACONCOUNT1 and W_BEACONCOUNT2 (which are decremented when lower 10bit of W_US_COUNT wrap from 3FFh to 000h). Note: W_POWER_US must be enabled, too.
48080F8h - W_US_COUNT0 - Microsecond counter, bits 0-15 (R/W)
48080FAh - W_US_COUNT1 - Microsecond counter, bits 16-31 (R/W)
48080FCh - W_US_COUNT2 - Microsecond counter, bits 32-47 (R/W)
48080FEh - W_US_COUNT3 - Microsecond counter, bits 48-63 (R/W)

      0-63  Counter Value in microseconds (incrementing)

Clocked by the 22.00MHz oscillator on the RFU board (ie. not by the 33.51MHz system clock). The 22.00MHz are divided by a 22-step prescaler.
48080EAh - W_US_COMPARECNT - Microsecond compare enable (R/W)

      0     Compare Enable (0=Disable, 1=Enable) (IRQ14/IRQ15)
      1     Force IRQ14    (0=No, 1=Force Now)   (Write-only)
      2-15  Always zero

Activates IRQ14 on W_US_COMPARE matches, and IRQ14/IRQ15 on W_BEACONCOUNT1.
48080F0h - W_US_COMPARE0 - Microsecond compare, bits 0-15 (R/W)
48080F2h - W_US_COMPARE1 - Microsecond compare, bits 16-31 (R/W)
48080F4h - W_US_COMPARE2 - Microsecond compare, bits 32-47 (R/W)
48080F6h - W_US_COMPARE3 - Microsecond compare, bits 48-63 (R/W)

      0     Always zero... firmware writes 1 though (maybe write-only flag?)
      1-9   Always zero
      10-63 Compare Value in milliseconds (aka microseconds/1024)

Triggers IRQ14 (see IRQ14 notes below) when W_US_COMPARE matches W_US_COUNT.
Usually set to FFFFFFFFFFFFFC00h (ie. almost/practically never). Instead, IRQ14 is usually derived via W_BEACONCOUNT1.
480811Ch - W_BEACONCOUNT1 (R/W)
Triggers IRQ14 and IRQ15 (see IRQ14/IRQ15 notes below) when it reaches 0000h (if W_PRE_BEACON is non-zero, then IRQ15 occurs that many microseconds in advance).

      0-15  Decrementing Millisecond Counter (reloaded with W_BEACONINT upon IRQ14)

Set to W_BEACONINT upon IRQ14 events (unlike the other W_US_COMPARE related actions, this is done always, even if W_US_COMPARECNT is zero).
When reaching 0000h, it is immediately reloaded (as for US_COUNT matches), so the counting sequence is ..,3,2,1,BEACONINT,.. (not 3,2,1,ZERO,BEACONINT).
4808134h - W_BEACONCOUNT2 - Post-Beacon Counter (R/W)

      0-15  Decrementing Millisecond Counter (reloaded with FFFFh upon IRQ14)

Triggers IRQ13 when it reaches 0000h (no matter of W_US_COMPARECNT), and does then stay fixed at 0000h (without any further decrement/wrapping to FFFFh).
Set to FFFFh upon IRQ14 (by hardware), the IRQ14 handler should then adjust the register (by software) by adding the Tag DDh Beacon header's Stepping value (usually 000Ah) to it.
Seems to be used to indicate beacon transmission time (possible including additional time being reserved for responses)?
480808Ch - W_BEACONINT - Beacon Interval (R/W)
Reload value for W_BEACONCOUNT1.

      0-9   Frequency in milliseconds of beacon transmission
      10-15 Always zero

Should be initialized randomly to 0CEh..0DEh or so. The random setting reduces risk of repeated overlaps with beacons from other hosts.
4808110h - W_PRE_BEACON - Pre-Beacon Time (R/W)

      0-15  Pre-Beacon Time in microseconds (static value, ie. NOT decrementing)

Allows to define the distance between IRQ15 and IRQ14. The setting doesn't affect the IRQ14 timing (which occurs at the W_BEACONCOUNT1'th millisecond boundary), but IRQ15 occurs in advance (at the W_BEACONCOUNT1'th millisecond boundary minus W_PRE_BEACON microseconds). If W_PRE_BEACON is zero, then both IRQ14 and IRQ15 occur exactly at the same time.
4808088h - W_LISTENCOUNT - Listen Count (R/W)

      0-7   Decremented by hardware at IRQ14 events (ie. once every beacon)
      8-15  Always zero

Reload occurs immediately BEFORE decrement, ie. with W_LISTENINT=04h, it will go through values 03h,02h,01h,00h,03h,02h,01h,00h,etc.
480808Eh - W_LISTENINT - Listen Interval (R/W)

      0-7   Listen Interval, counted in beacons (usually 02h)
      8-15  Always zero

Reload value for W_LISTENCOUNT.
480810Ch - W_CONTENTFREE (R/W)

      0-15  Decrementing microsecond counter

Operated always (no matter of W_US_COUNTCNT).
Once when it has reached 0000h, it seems to stay fixed at 0000h.
"[Set to the remaining duration of contention-free period when
receiving beacons - only *really* necessary for powersaving mode]"
IRQ13 Notes (Post-Beacon Interrupt)
IRQ13 is generated by W_BEACONCOUNT2. It's simply doing:

      W_IF.Bit13=1      ;interrupt request

If W_POWER_TX.Bit1=0, then additionally enter sleep mode:

      [4808034h]=0002h ;W_INTERNAL   ;(similar to W_POWERFORCE=8001h)
      [480803Ch]=02xxh ;W_POWERSTATE ;(W_TXREQ_READ.Bit4 is kept intact though)
      [480819Ch]=0046h ;W_RF_PINS.7=0;disable receive (enter idle mode) (RX.ON=Low)
      [4808214h]=0009h ;W_RF_STATUS=9;indicate idle mode

Unlike for IRQ14/IRQ15, that's done no matter of W_US_COMPARECNT.
IRQ14 Notes (Beacon Interrupt)
IRQ14 is generated by W_US_COMPARE, and by W_BEACONCOUNT1.
Aside from just setting the IRQ flag in W_IF, the hardware does:

      W_BEACONCOUNT1=W_BEACONINT                             ;next IRQ15/IRQ14
      (Above is NOT done when IRQ14 was forced via W_US_COMPARECNT.Bit1)

If W_US_COMPARECNT is 1, then the hardware does additionally:

      (Below IS ALSO DONE when IRQ14 was forced via W_US_COMPARECNT.Bit1)
      W_IF.Bit14=1
      W_BEACONCOUNT2=FFFFh ;about 64 secs (ie. almost never) ;next IRQ13 ("never")
      W_TXREQ_READ=W_TXREQ_READ AND FFF2h
      if W_TXBUF_BEACON.15 then W_TXBUSY.Bit4=1
      if W_LISTENCOUNT=00h then W_LISTENCOUNT=W_LISTENINT
      W_LISTENCOUNT=W_LISTENCOUNT-1

If W_TXBUF_BEACON.Bit15=1, then following is done shortly after IRQ14:

      W_RF_PINS.Bit7=0  ;disable receive (RX.ON=Low)
      W_RF_STATUS=2     ;indicate switching from RX to TX mode

If W_TXBUF_BEACON.Bit15=1, then following is done a bit later:

      W_RF_PINS.Bit6=1  ;transmit preamble start (TX.ON=High)
      W_RF_STATUS=3     ;indicate TX mode

The IRQ14 handler should then do the following (by software):

      W_BEACONCOUNT2 = W_BEACONCOUNT2 + TagDDhSteppingValue  ;next IRQ13

For using only ONE of the two IRQ14 sources: W_BEACONCOUNT1 can be disabled by setting both W_BEACONCOUNT1 and W_BEACONINT to zero. W_US_COMPARE can be sorts of "disabled" by setting it to value distant from W_US_COUNT, such like compare=count-400h.
IRQ07 Notes (Transmit Start Data; occurs after preamble)

      W_IF.Bit7=1       ;interrupt request
      W_RF_PINS.Bit1=1  ;start data transfer (preamble finished now) (TX.MAIN=High)

Below only if packet was sent through W_TXBUF_BEACON, or if it was sent via W_TXBUF_LOCn, with W_TXBUF_LOCn.Bit13 being zero:

      [TXBUF...] = W_TX_SEQNO*10h   ;auto-adjust IEEE Sequence Control
      W_TX_SEQNO=W_TX_SEQNO+1       ;increase sequence number

IRQ01 Notes (Transmit Done)
The following happens shortly before IRQ01:

      W_RF_PINS.Bit6=0  ;disable TX (TX.ON=Low)
      W_RF_STATUS=4     ;indicate switching from TX to RX mode

Then, upon IRQ01, the following happens:

      W_IF.Bit1=1       ;interrupt request
      W_RF_PINS.Bit1=0  ;disable TX (TX.MAIN=Low)
      W_RF_PINS.Bit7=1  ;enable RX (RX.ON=High)
      W_RF_STATUS=1     ;indicate RX mode

IRQ15 Notes (Pre-Beacon Interrupt)
IRQ15 is generated via W_BEACONCOUNT1 and W_PRE_BEACON. It's simply doing:

      if W_US_COMPARECNT=1 then W_IF.Bit15=1

If W_POWER_TX.Bit0=1, then additionally wakeup from sleep mode:

      W_RF_PINS.Bit7=1  ;enable RX (RX.ON=High) ;\gets set like so a good while
      W_RF_STATUS=1     ;indicate RX mode       ;/after IRQ15 (but not immediately)

Beacon IRQ Sequence

      IRQ15  Pre-Beacon  (beacon will be transferred soon)
      IRQ14  Beacon      (beacon will be transferred very soon) (carrier starts)
      IRQ07  Tx Start    (beacon transfer starts) (if enabled in W_TXBUF_BEACON.15)
      IRQ01  Tx End      (beacon transfer done) (if enabled in W_TXSTATCNT.15)
      IRQ13  Post-Beacon (beacon transferred) (unless next IRQ14 occurs earlier)

That, for tranmitting beacons. (For receiving, IRQ07/IRQ01 would be replaced by Rx IRQ's, provided that a remote unit is sending beacons).

DS Wifi Multiplay Master

These registers are used for multiplay host-to-client (aka master to slave) commands.
48080EEh - W_CMD_COUNTCNT (R/W)

      0     Enable W_CMD_COUNT (0=Disable, 1=Enable)
      1-15  Always Zero

4808118h - W_CMD_COUNT (R/W)

      0-15  Decremented once every 10 microseconds (Stopped at 0000h)

Written by firmware. Firmware IRQ14 handler checks for read value<=0Ah.
When it reaches zero, W_TXBUF_CMD is transferred (if enabled in W_TXBUF_CMD.Bit15, and in W_TXREQ_READ.Bit1), it does then trigger two (!) transfer start interrupts (IRQ07), transfer end is then indicated by a single IRQ12, optionally (when enabled in W_TXSTATCNT, IRQ01 (transfer done) is additionally generated (simultaneously with above IRQ12).
NOPE, above isn't quite right..... when W_CMD_COUNT is set to a very small value, then ONLY IRQ12 is triggered (so it might specify the duration during which the IRQ07's for W_TXBUF_CMD are allowed?)
48080C0h - W_CMD_TOTALTIME - (R/W)

      0-15  Duration per ALL slave response packet(s) in microseconds

Before sending a MASTER packet, this port should be set to the same value as the MASTER packet's IEEE header's Duration/ID entry.
48080C4h - W_CMD_REPLYTIME - (R/W)

      0-15  Duration per SINGLE slave response packet in microseconds

Before sending a MASTER packet, this port should be set to the expected per slave response time.
Note: Nintendo's multiboot/pictochat code is also putting this value in the 1st halfword of the MASTER packet's frame body.
At 2MBit/s transfer rate, the values should be set up sorts of like so:

      master_time = (master_bytes*4)+(60h)     ;60h = 96 decimal = short preamble
      slave_time = (slave_bytes*4)+(0D0h..0D2h)
      all_slave_time = (EAh..F0h)+(slave_time+0Ah)*num_slaves
      txhdr[2]   = slave_bits      ;hardware header (*)
      ieee[2]    = all_slave_time  ;ieee header (duration/id)
      body[0]    = slave_time      ;duration per slave (for multiboot/pictochat)
      body[2]    = slave_bits      ;frame body -- required (*)
      [48080C0h] = all_slave_time  ;
      [48080C4h] = slave_time      ;duration per slave
      [4808118h] = (388h+(num_slaves*slave_time)+master_time+32h)/10
      [4808090h] = 8000h+master_packet_address   ;start transmit

With the byte values counting the ieee frame header+body+fcs.
(*) The hardware doesn't actually seem to use the "slave_bits" entry in the hardware header, instead, it is using the "slave_bits" entry in the frame body(!)

DS Wifi Multiplay Slave

These registers are used for multiplay client-to-host (aka slave to master) responses.
4808094h - W_TXBUF_REPLY1 - Multiplay Response Transmit Location 1 (R/W)

      0-11  Halfword address
      12-14 Unknown (the bits can be set, ie. they DO exist)
      15    Enable

Response packet address. The register setting probably doesn't directly affect the hardware, it's sole purpose seems to initialize 4808098h (see there).
4808098h - W_TXBUF_REPLY2 - Multiplay Response Transmit Location 2 (R)

      0-11  Halfword address
      12-14 Unknown (the bits can be set, ie. they DO exist)
      15    Enable

This register seems to contain the actual response packet address. However, since it's read-only, software cannot set it directly. Instead, software must write the address to 4808094h, and then latch it from 4808094h to 4808098h (via. W_RXCNT.Bit7).
Notes
Not sure if there's also auto-latching (similar to manual W_RXCNT.Bit7)?
Unknown if W_TXBUF_REPLY2.Bit15 is automatically reset after transfer?
Not sure if/how the hardware determines WHEN to send reply packets (eg. it should NOT send them after receiving Beacons) (eventually the Start Receive IRQ handler must examine the incoming packet, and then software must decide if it wants to respond by sending the reply) (if there are multiple slaves, the response order is probably automatically handled in respect to the local W_AID_LOW setting) (although, if, for example, ONLY slave 5 exists, then it ought to know that slave 5 is the <first> slave; that might happen if slave 1..4 have left the communication; that, unless the slaves would be automatically renumbered by software (?), so slave 5 would be become slave 1). Some of the Unknown Registers (namely Ports W_X_244h and W_X_228h) are probably also related to the REPLY function.

DS Wifi Configuration Ports

4808120h - W_CONFIG_120h (R/W) ;init from firmware[04Ch] ;81ff 0048->SAME
4808122h - W_CONFIG_122h (R/W) ;init from firmware[04Eh] ;ffff 4840->SAME
4808124h - W_CONFIG_124h (R/W) ;init from firmware[05Eh] ;ffff 0000->0032
4808128h - W_CONFIG_128h (R/W) ;init from firmware[060h] ;ffff 0000->01F4
4808130h - W_CONFIG_130h (R/W) ;init from firmware[054h] ;0fff 0142->0140
4808132h - W_CONFIG_132h (R/W) ;init from firmware[056h] ;8fff 8064->SAME
4808140h - W_CONFIG_140h (R/W) ;init from firmware[058h] ;ffff 0000->E0E0
4808142h - W_CONFIG_142h (R/W) ;init from firmware[05Ah] ;ffff 2443->SAME
4808144h - W_CONFIG_144h (R/W) ;init from firmware[052h] ;00ff 0042->SAME
4808146h - W_CONFIG_146h (R/W) ;init from firmware[044h] ;00ff 0016->0002
4808148h - W_CONFIG_148h (R/W) ;init from firmware[046h] ;00ff 0016->0017
480814Ah - W_CONFIG_14Ah (R/W) ;init from firmware[048h] ;00ff 0016->0026
480814Ch - W_CONFIG_14Ch (R/W) ;init from firmware[04Ah] ;ffff 162C->1818
4808150h - W_CONFIG_150h (R/W) ;init from firmware[062h] ;ff3f 0204->0101
4808154h - W_CONFIG_154h (R/W) ;init from firmware[050h] ;7a7f 0058->SAME
These ports are to be initialized from firmware settings.
Above comments show the R/W bits (eg. 81FFh means bit15 and bit8-0 are R/W, bit14-9 are always zero), followed by the initial value on Reset (eg. 0048h), followed by new value after initialization from firmware settings (eg. 0032h, or SAME if the Firmware value is equal to the Reset value; these values seem to be identical in all currently existing consoles).
Note: Firmware part4 changes W_CONFIG_124h to C8h, and W_CONFIG_128h to 7D0h, and W_CONFIG_150h to 202h, and W_CONFIG_140h depending on tx rate and preamble:

      W_CONFIG_140h = firmware[058h]+0202h             ;1Mbit/s
      W_CONFIG_140h = firmware[058h]+0202h-6161h       ;2Mbit/s with long preamble
      W_CONFIG_140h = firmware[058h]+0202h-6161h-6060h ;2Mbit/s with short preamble

48080ECh - W_CONFIG_0ECh (R/W) ;firmware writes 3F03h (same as on power-up)
48080D4h - W_CONFIG_0D4h (R/W) ;firmware writes 0003h (affectd by W_MODE_RST)
48080D8h - W_CONFIG_0D8h (R/W) ;firmware writes 0004h (same as on power-up)
4808254h - W_CONFIG_254h (?) ;firmware writes 0000h (read: EEEEh on DS-Lite)
Firmware just initializes these ports with fixed values, without further using them after initialization.
48080DAh - W_RX_LEN_CROP (R/W) ;firmware writes 0602h (same as on power-up)

      0-7   Decrease RX Length by N halfwords for Non-WEP packets (usually 2)
      8-15  Decrease RX Length by N halfwords for WEP packets     (usually 6)

Used to exclude the FCS (and WEP IV+ICV) from the length entry in the Hardware RX Header.

DS Wifi Baseband Chip (BB)

BB-Chip Mitsumi MM3155 (DS), or BB/RF-Chip Mitsumi MM3218 (DS-Lite)
4808158h - W_BB_CNT - Baseband serial transfer control (W)

      0-7   Index     (00h-68h)
      8-11  Not used  (should be zero)
      12-15 Direction (5=Write BB_WRITE to Chip, 6=Read from Chip to BB_READ)

Transfer is started after writing to this register.
480815Ah - W_BB_WRITE - Baseband serial write data (W)

      0-7   Data to be sent to chip (by following W_BB_CNT transfer)
      8-15  Not used (should be zero)

480815Ch - W_BB_READ - Baseband serial read data (R)

      0-7   Data received from chip (from previous W_BB_CNT transfer)
      8-15  Not used (always zero)

480815Eh - W_BB_BUSY - Baseband serial busy flag (R)

      0     Transfer Busy (0=Ready, 1=Busy)
      1-15  Always zero

Used to sense transfer completion after writes to W_BB_CNT.
Not sure if I am doing something wrong... but the busy flag doesn't seem to get set immediately after W_BB_CNT writes, and works only after waiting a good number of clock cycles?
4808160h - W_BB_MODE (R/W)

      0-7   Always zero
      8     Unknown (usually 1) (no effect no matter what setting?)
      9-13  Always zero
      14    Unknown (usually 0) (W_BB_READ gets unstable when set)
      15    Always zero

This register is initialized by firmware bootcode - don't change.
4808168h - W_BB_POWER (R/W)

      0-3   Disable whatever   (usually 0Dh=disable)
      4-14  Always zero
      15    Disable W_BB_ports (usually 1=Disable)

Must be set to 0000h before accessing BB registers.
Read-Write-Ability of the BB-Chip Mitsumi MM3155 registers (DS)

      Index    Num Dir Expl.
      00h        1 R   always 6Dh (R) (Chip ID)
      01h..0Ch  12 R/W 8bit R/W
      0Dh..12h   6 -   always 00h
      13h..15h   3 R/W 8bit R/W
      16h..1Ah   5 -   always 00h
      1Bh..26h  12 R/W 8bit R/W
      27h        1 -   always 00h
      28h..4Ch     R/W 8bit R/W
      4Dh        1 R   always 00h or BFh (depending on other regs)
      4Eh..5Ch     R/W 8bit R/W
      5Dh        1 R   always 01h (R)
      5Eh..61h     -   always 00h
      62h..63h   2 R/W 8bit R/W
      64h        1 R   always FFh or 3Fh (depending on other regs)
      65h        1 R/W 8bit R/W
      66h        1 -   always 00h
      67h..68h   2 R/W 8bit R/W
      69h..FFh     -   always 00h

Read-Write-Ability of the BB/RF-Chip Mitsumi MM3218 (DS-Lite)
Same as above. Except that reading always seems to return [5Dh]=00h. And, for whatever reason, Nintendo initializes DS-Lite registers by writing [00h]=03h and [66h]=12h. Nethertheless, the registers always read as [00h]=6Dh and [66h]=00h, ie. same as on original DS.
Important BB Registers
Registers 0..68h are initialized by firmware bootcode, and (most) of these settings do not need to be changed by other programs, except for:

      Addr Initial Meaning
      01h 0x9E    [unsetting/resetting bit 7 initializes/resets the system?]
      02h         unknown (firmware is messing with this register)
      06h         unknown (firmware is messing with this register, too)
      13h 0x00    CCA operation - criteria for receiving
                        0=only use Carrier Sense (CS)
                        1=only use Energy Detection (ED)
                        2=receive if CS OR ED
                        3=receive only if CS AND ED
      1Eh 0xBB    see change channels flowchart (Ext. Gain when RF[09h].bit16=0)
      35h 0x1F    Energy Detection (ED) criteria
                  value 0..61 (representing energy levels of -60dBm to -80dBm)

DS Wifi RF Chip

RF-Chip RF9008 (compatible to RF2958 from RF Micro Devices, Inc.) (Original DS)
BB/RF-Chip Mitsumi MM3218 (DS-Lite)
480817Ch - W_RF_DATA2 - RF chip serial data/transfer enable (R/W)
For Type2 (ie. firmware[040h]<>3):

      0-1   Upper 2bit of 18bit data
      2-6   Index   (00h..1Fh) (firmware uses only 00h..0Bh)
      7     Command (0=Write data, 1=Read data)
      8-15  Should be zero (not used with 24bit transfer)

For Type3 (ie. firmware[040h]=3):

      0-3   Command (5=Write data, 6=Read data)
      4-15  Should be zero (not used with 20bit transfer)

Writing to this register starts the transfer.
480817Eh - W_RF_DATA1 - RF chip serial data (R/W)
For Type2 (ie. firmware[040h]<>3):

      0-15  Lower 16bit of 18bit data

For Type3 (ie. firmware[040h]=3):

      0-7   Data (to be written to chip) (or being received from chip)
      8-15  Index (usually 00h..28h) (index 40h..FFh are mirrors of 00h..3Fh)

This value should be set before setting W_RF_DATA2.
4808180h - W_RF_BUSY - RF chip serial busy flag (R)

      0     Transfer Busy (0=Ready, 1=Busy)
      1-15  Always zero

Used to sense transfer completion after writes to W_RF_DATA2.
4808184h - W_RF_CNT - RF chip serial control (R/W)

      0-5   Transfer length (init from firmware[041h].Bit0-5)
      6-7   Always zero
      8     Unknown         (init from firmware[041h].Bit7)
      9-13  Always zero
      14    Unknown         (usually 0)
      15    Always zero

This register is initialized by firmware bootcode - don't change.
Usually, Type2 has length=24bit and flag=0. Type3 uses length=20bit and flag=1.
Caution For Type2 (ie. firmware[040h]<>3)
Before accessing Type2 RF Registers, first BB[01h] must have been properly initialized (ie. BB[01h].Bit7 must have been toggled from 0-to-1).

DS Wifi RF9008 Registers

RF9008 (RF2958 compatible)
2.4GHz Spread-Spectrum Transceiver - RF Micro Devices, Inc.
RF chip data (Type2) (initial NDS settings from firmware, example)

      Firmware   Index   Data
      (24bit)    (4bit)  (18bit)
      00C007h  =  00h  + 0C007h ;-also set to 0C008h for power-down
      129C03h  =  04h  + 29C03h
      141728h  =  05h  + 01728h ;\these are also written when changing channels
      1AE8BAh  =  06h  + 2E8BAh ;/
      1D456Fh  =  07h  + 1456Fh
      23FFFAh  =  08h  + 3FFFAh
      241D30h  =  09h  + 01D30h ;-bit10..14 should be also changed per channel?
      """"50h  =  """  + """50h ;firmware v5 and up uses narrower tx filter
      280001h  =  0Ah  + 00001h
      2C0000h  =  0Bh  + 00000h
      069C03h  =  01h  + 29C03h
      080022h  =  02h  + 00022h
      0DFF6Fh  =  03h  + 1FF6Fh

RF[00h] - Configuration Register 1 (CFG1) (Power on: 00007h)

      17-16 Reserved, program to zero (0)
      15-14 Reference Divider Value (0=Div2, 1=Div3, 2=Div44, 3=Div1)
      3     Sleep Mode Current      (0=Normal, 1=Very Low)
      2     RF VCO Regulator Enable (0=Disable, 1=Enable)
      1     IF VCO Regulator Enable (0=Disable, 1=Enable)
      0     IF VGA Regulator Enable (0=Disable, 1=Enable)

RF[01h] - IF PLL Register 1 (IFPLL1) (Power on: 09003h)

      17    IF PLL Enable                      (0=Disable, 1=Enable)
      16    IF PLL KV Calibration Enable       (0=Disable, 1=Enable)
      15    IF PLL Coarse Tuning Enable        (0=Disable, 1=Enable)
      14    IF PLL Loop Filter Select          (0=Internal, 1=External)
      13    IF PLL Charge Pump Leakage Current (0=Minimum value, 1=2*Minimum value)
      12    IF PLL Phase Detector Polarity     (0=Positive, 1=Negative)
      11    IF PLL Auto Calibration Enable     (0=Disable, 1=Enable)
      10    IF PLL Lock Detect Enable          (0=Disable, 1=Enable)
      9     IF PLL Prescaler Modulus           (0=4/5 Mode, 1=8/9 Mode)
      8-4   Reserved, program to zero (0)
      3-0   IF VCO Coarse Tuning Voltage       (N=Voltage*16/VDD)

RF[02h] - IF PLL Register 2 (IFPLL2) (Power on: 00022h)

      17-16 Reserved, program to zero (0)
      15-0  IF PLL divide-by-N value

RF[03h] - IF PLL Register 3 (IFPLL3) (Power on: 1FF78h)

      17    Reserved, program to zero (0)
      16-8  IF VCO KV Calibration, delta N value (signed)  ;DeltaF=(DN/Fr)
      7-4   IF VCO Coarse Tuning Default Value
      3-0   IF VCO KV Calibration Default Value

RF[04h] - RF PLL Register 1 (RFPLL1) (Power on: 09003h)

      17-10 Same as for RF[01h] (but for RF, not for IF)
      9     RF PLL Prescaler Modulus (0=8/9 Mode, 1=8/10 Mode)
      8-0   Same as for RF[01h] (but for RF, not for IF)

RF[05h] - RF PLL Register 2 (RFPLL2) (Power on: 01780h)

      17-6  RF PLL Divide By N Value
      5-0   RF PLL Numerator Value (Bits 23-18)

RF[06h] - RF PLL Register 3 (RFPLL3) (Power on: 00000h)

      17-0  RF PLL Numerator Value (Bits 17-0)

RF[07h] - RF PLL Register 4 (RFPLL4) (Power on: 14578h)

      17-10 Same as for RF[03h] (but for RF, not for IF) ;and, DN=(deltaF/Fr)*256

RF[08h] - Calibration Register 1 (CAL1) (Power on: 1E742h)

      17-13  VCO1 Warm-up Time  ;TVCO1=(approximate warm-up time)*(Fr/32)
      12-8   VCO1 Tuning Gain Calibration ;TLOCK1=(approximate lock time)*(Fr/128)
      7-3    VCO1 Coarse Tune Calibration Reference  ;VALUE=(average time)*(Fr/32)
      2-0    Lock Detect Resolution (0..7)

RF[09h] - TXRX Register 1 (TXRX1) (Power on: 00120h)

      17    Receiver DC Removal Loop          (0=Enable DC Removal Loop, 1=Disable)
      16    Internal Variable Gain for VGA  (0=Disable/External, 1=Enable/Internal)
      15    Internal Variable Gain Source (0=From TXVGC Bits, 1=From Power Control)
      14-10 Transmit Variable Gain Select (TXVGC)   (0..1Fh = High..low gain)
      9-7   Receive Baseband Low Pass Filter     (0=Wide Bandwidth, 7=Narrow)
      6-4   Transmit Baseband Low Pass Filter    (0=Wide Bandwidth, 7=Narrow)
      3     Mode Switch            (0=Single-ended mode, 1=Differential mode)
      2     Input Buffer Enable TX (0=Input Buffer Controlled by TXEN, 1=By BBEN)
      1     Internal Bias Enable   (0=Disable/External, 1=Enable/Internal)
      0     TX Baseband Filters Bypass        (0=Not Bypassed, 1=Bypassed)

RF[0Ah] - Power Control Register 1 (PCNT1) (Power on: 00000h)

      17-15 Select MID_BIAS Level                          (1.6V through 2.6V)
      14-9  Desired output power at antenna                (N*0.5dBm)
      8-3   Power Control loop-variation-adjustment Offset (signed, N*0.5dB)
      2-0   Desired delay for using a single TX_PE line    (N*0.5us)

RF[0Bh] - Power Control Register 2 (PCNT2) (Power on: 00000h)

      17-12 Desired MAX output power when PABIAS=MAX=2.6V (N*0.5dBm)
      11-6  Desired MAX output power when PABIAS=MID_BIAS (N*0.5dBm)
      5-0   Desired MAX output power when PABIAS=MIN=1.6V (N*0.5dBm)

RF[0Ch] - VCOT Register 1 (VCOT1) (Power on: 00000h)

      17    IF VCO Band Current Compensation (0=Disable, 1=Enable)
      16    RF VCO Band Current Compensation (0=Disable, 1=Enable)
      15-0  Reserved, program to zero (0)

RF[0Dh..1Ah] - N/A (Power on: 00000h)

      Not used.

RF[1Bh] - Test Register 1 (TEST) (Power on: 0000Fh)

      17-0  This is a test register for internal use only.

RF[1Ch..1Eh] - N/A (Power on: 00000h)

      Not used.

RF[1Fh] - Reset Register (Power on: 00001h)

      17-0  Don't care (writing any value resets the chip)

DS Wifi Unknown Registers

480800Ah - W_X_00Ah (R/W)

      0-15  Unknown (usually zero)

"[bit7 - ingore rx duplicates]" <--- that is NOT correct (no effect).
Firmware writes 0000h to it. That, done many times. So, eventually some bits in this register are automatically set by hardware in whatever situations, otherwise repeatedly writing 0000h to it would be kinda useless...?
---
Below Ports W_X_244h and W_X_228h might be related to deciding when to send multiplay replies...?
4808244h - W_X_244h (R/W) x ffff [0000] (used by firmware part4)
Unknown. Seems to be W_IF/W_IE related. Firmware sets 4808Port 244h bits 6,7,12 to 1-then-0 upon IRQ06,IRQ07,IRQ12 respectively.
4808228h - W_X_228h (W) fixx [0000] (used by firmware part4) (bit3)
Unknown. Firmware writes 8-then-0 (done in IRQ06 handler, after Port 4808244h access).
---
Below Ports 48081A0h, 48081A2h, 48081A4h are somehow related to BB[02h]...
48081A0h - W_X_1A0h - (R/W) -933 [0000]

      0-1   Unknown
      2-3   Always zero
      4-5   Unknown
      6-7   Always zero
      8     Unknown
      9-10  Always zero
      11    Unknown
      12-15 Always zero

Firmware writes values 000h, 823h. Seems to be power-related. The following experimental code toggles RXTX.ON (RFU.Pin4): "x=0 / @@lop: / [48081A0h]=x / [4808036h]=0 / x=x XOR 3 / wait_by_loop(1000h) / b @@lop".
Also, writing to port 48081A0h affects ports 4808034h, 480819Ch, 480821Ch, and 48082A2h.
48081A2h - W_X_1A2h - (R/W) ---3 [0001] (used by firmware part4)

      0-1   Unknown. Firmware writes values 03h, 01h, and VAR.
      2-15  Always zero

Used in combination with Port 48081A0h, so it's probably power-related, too.
48081A4h - W_X_1A4h - (R/W) ffff [0000]
"Rate used when signal test is enabled (0x0A or 0x14 for 1 or 2 mbit)"
(Not too sure if that's correct, there is no visible relation to any rate.)
(This register seems to be R/W only on certain Port 48081A0h settings.)
Unknown. Firmware writes whatever.
---
4808290h - W_X_290h - (R/W or Disabled)
Reportedly, this is the "antenna" register, which should exist on official devkits, allowing to switch between wired Ethernet, and wireless Wifi mode.

      0     Unknown (R/W) (if present)
      1-15  Not used

On normal NDS release versions, this register seems to be disabled (if it is implemented at all), and trying to read from it acts as for unused registers, ie. reads return FFFFh (or probably 0000h on NDS-lite). The NDS firmware contains code for accessing this port, even in release versions.
W_INTERNAL
All registers marked as "W_INTERNAL" aren't used by Firmware part4, and are probably unimportant, except for whatever special diagnostics purposes.
Wifi DMA
Wifi RAM can be accessed with normal "Start Immediately" DMA transfers (typically by reading through W_RXBUF_RD_DATA, so the DMA automatically wraps from END to BEGIN).
Additionally, DMA0 and DMA2 can be reportedly synchronized to "Wireless Interrupt" (rather than using "Start Immediately" timing), no idea if/how that's working though... and if it gets started on any Wifi IRQ, or only on specific IRQs...?
Possibly some of the above unknown registers, or some unknown bits in other registers, are DMA related...?
Reportedly, early firmwares did use "Wireless Interrupt" DMAs (that'd be firmware v1/v2... or, only earlier unreleased prototype versions?).

DS Wifi Unused Registers

Wifi WS0 and WS1 Regions in NDS7 I/O Space
Wifi hardware occupies two 32K slots, but most of it is filled with unused or duplicated regions. The timings (waitstates) for WS0 and WS1 are initialized in WIFIWAITCNT (by firmware).

      4800000h-4807FFFh Wifi WS0 Region (32K)
      4808000h-4808000h Wifi WS1 Region (32K)
      4810000h-4FFFFFFh Not used (00h-filled)

Structure of the 32K Wifi Regions (WS0 and WS1)

      Wifi-WS0-Region    Wifi-WS1-Region    Content
      4800000h-4800FFFh  4808000h-4808FFFh  Registers
      4801000h-4801FFFh  4809000h-4809FFFh  Registers (mirror)
      4802000h-4803FFFh  480A000h-480BFFFh  Unused
      4804000h-4805FFFh  480C000h-480DFFFh  Wifi RAM  (8K)
      4806000h-4806FFFh  480E000h-480EFFFh  Registers (mirror)
      4807000h-4807FFFh  480F000h-480FFFFh  Registers (mirror)

Wifi Registers (recommended 4808000h-4808FFFh) appear more stable in WS1?
Wifi RAM (recommended 4804000h-4805FFFh) appears more stable in WS0?
Unused Ports (Original NDS)
Aside from those ports listed in the Wifi I/O Map, all other ports in range 4808000h..4808FFFh are unused. On the original DS, reading from these ports returns FFFFh.
Unused Ports (NDS-Lite)
Reading from unused I/O ports acts as PASSIVE mirror of W_RXBUF_RD_DATA. Exceptions are: Ports 4808188h, and 48082D8h..48082E6h; which always return 0000h.
Unused Memory (Original NDS)
Unused Wifi Memory is at 2000h..3FFFh. On the original DS, reading from that region returns FFFFh.
Unused Memory (NDS-Lite)
Reading from unused memory acts as PASSIVE mirror of WifiRAM (ie. reading from it returns the value being most recently read from 4000h..5FFFh) (that not affected by indirect WifiRAM reads via W_RXBUF_RD_DATA) (and, that not affected by writes to wifi memory, including writes that do overwrite the most recent read value) (and, that only if WifiRAM is properly enabled, ie. Port 220h.Bits0-1 should be 0).
Moreover, certain addresses are additionally ORed with mirrored I/O Ports. That addresses are:

      2030h, 2044h, 2056h, 2080h, 2090h, 2094h, 2098h, 209Ch, 20A0h, 20A4h,
      20A8h, 20AAh, 20B0h, 20B6h, 20BAh, 21C0h, 2208h, 2210h, 2244h, 31D0h,
      31D2h, 31D4h, 31D6h, 31D8h, 31DAh, 31DCh, 31DEh.

For example, 2044h is a PASSIVE mirror of WifiRAM, ORed with an ACTIVE mirror of W_RANDOM (Port 044h). Note that some mirrors are at 2000h-2FFFh, and some at 3000h-3FFFh. The W_CMD_STAT mirrors are PASSIVE (that, in unused memory region only) (in normal port-mirror regions like 1000h-1FFF, W_CMD_STAT mirrors are ACTIVE).
Known (W) Mirrors (when reading from Write-only ports)

      Read from (W)           Mirrors to (NDS)       Or to (NDS-Lite)
      070h W_TXBUF_WR_DATA    060h W_RXBUF_RD_DATA   074h W_TXBUF_GAP
      078h W_INTERNAL         068h W_TXBUF_WR_ADDR   074h W_TXBUF_GAP
      0ACh W_TXREQ_RESET      09Ch W_INTERNAL        ? (zero)
      0AEh W_TXREQ_SET        09Ch W_INTERNAL        ? (zero)
      0B4h W_TXBUF_RESET      0B6h W_TXBUSY          ? (zero)
      158h W_BB_CNT           15Ch W_BB_READ         ? (zero)
      15Ah W_BB_WRITE         ? (zero)               ? (zero)
      178h W_INTERNAL         17Ch W_RF_DATA2        ? (zero)
      20Ch W_INTERNAL         09Ch W_INTERNAL        ? (zero)
      21Ch W_IF_SET           010h W_IF              010h-OR-05Ch-OR-more?
      228h W_X_228h           ? (zero)               ? (zero)
      298h W_INTERNAL         084h W_TXBUF_TIM       084h W_TXBUF_TIM
      2A8h W_INTERNAL         238h W_INTERNAL        238h W_INTERNAL
      2B0h W_INTERNAL         084h W_TXBUF_TIM       084h W_TXBUF_TIM

Notes: The mirror to W_RXBUF_RD_DATA is a passive mirror.
The DS-Lite mirror at 21Ch consists of several ports ORed with each other (known components are Ports 010h and 05Ch, but there seem to be even more values ORed with it).
Port Mirror Regions
The Wifi Port region at 000h..FFFh is mirrored to 1000h..1FFFh, 6000h..6FFFh, and 7000h..7FFFh. Many of that mirrored ports are PASSIVE mirrors. Eg. reading from 1060h (mirror of Port 060h, W_RXBUF_RD_DATA) returns the old W_RXBUF_RD_DATA value (but without loading a new value from Wifi RAM, and without incrementing W_RXBUF_RD_ADDR). However, other registers, like W_RANDOM do have ACTIVE mirrors.

DS Wifi Initialization

Initialization sequence
These events must be done somewhat in sequence. There is some flexibility as to how they can be ordered but it's best to follow this order:

      [4000304h].Bit1 = 1 ;POWCNT2  ;-Enable power to the wifi system
      W_MACADDR = firmware[036h]    ;-Set 48bit Mac address
      reg[012h] = 0000h   ;W_IE     ;-Disable interrupts

Wake Up the wireless system:

      reg[036h] = 0000h ;W_POWER_US ;\clear all powerdown bits
      delay 8 ms                    ; (works without that killer-delay ?)
      reg[168h] = 0000h ;W_BB_POWER ;/
      IF firmware[040h]=02h         ;\
        temp=BB[01h]                ; for wifitype=02h only:
        BB[01h]=temp AND 7Fh        ; reset BB[01h].Bit7, then restore old BB[01h]
        BB[01h]=temp                ; (that BB setting enables the RF9008 chip)
      ENDIF                         ;/
      delay 30 ms                   ;-(more killer-delay now getting REALLY slow)
      call init_sub_functions       ;- same as "Init 16 registers by firmware[..]"
                                    ;  and "Init RF registers", below.
                                    ;  this or the other one probably not necessary

Init the Mac system:

      reg[004h] = 0000h   - W_MODE_RST       ;set hardware mode
      reg[008h] = 0000h   - W_TXSTATCNT      ;
      reg[00Ah] = 0000h   - ? W_X_00Ah       ;(related to rx filter)
      reg[012h] = 0000h   - W_IE             ;disable interrupts (again)
      reg[010h] = FFFFh   - W_IF             ;acknowledge/clear any interrupts
      reg[254h] = 0000h   - W_CONFIG_254h    ;
      reg[0B4h] = FFFFh   - W_TXBUF_RESET    ;--reset all TXBUF_LOC's
      reg[080h] = 0000h   - W_TXBUF_BEACON   ;disable automatic beacon transmission
      reg[02Ah] = 0000h   - W_AID_FULL       ;\clear AID
      reg[028h] = 0000h   - W_AID_LOW        ;/
      reg[0E8h] = 0000h   - W_US_COUNTCNT    ;disable microsecond counter
      reg[0EAh] = 0000h   - W_US_COMPARECNT  ;disable microsecond compare
      reg[0EEh] = 0001h   - W_CMD_COUNTCNT   ;(is 0001h on reset anyways)
      reg[0ECh] = 3F03h   - W_CONFIG_0ECh    ;
      reg[1A2h] = 0001h   - ?                ;
      reg[1A0h] = 0000h   - ?                ;
      reg[110h] = 0800h   - W_PRE_BEACON     ;
      reg[0BCh] = 0001h   - W_PREAMBLE       ;disable short preamble
      reg[0D4h] = 0003h   - W_CONFIG_0D4h    ;
      reg[0D8h] = 0004h   - W_CONFIG_0D8h    ;
      reg[0DAh] = 0602h   - W_RX_LEN_CROP    ;
      reg[076h] = 0000h   - W_TXBUF_GAPDISP  ;disable gap/skip (offset=zero)

Init 16 registers by firmware[044h..063h]

      reg[146h] = firmware[044h] ;W_CONFIG_146h
      reg[148h] = firmware[046h] ;W_CONFIG_148h
      reg[14Ah] = firmware[048h] ;W_CONFIG_14Ah
      reg[14Ch] = firmware[04Ah] ;W_CONFIG_14Ch
      reg[120h] = firmware[04Ch] ;W_CONFIG_120h
      reg[122h] = firmware[04Eh] ;W_CONFIG_122h
      reg[154h] = firmware[050h] ;W_CONFIG_154h
      reg[144h] = firmware[052h] ;W_CONFIG_144h
      reg[130h] = firmware[054h] ;W_CONFIG_130h
      reg[132h] = firmware[056h] ;W_CONFIG_132h
      reg[140h] = firmware[058h] ;W_CONFIG_140h
      reg[142h] = firmware[05Ah] ;W_CONFIG_142h
      reg[038h] = firmware[05Ch] ;W_POWER_TX
      reg[124h] = firmware[05Eh] ;W_CONFIG_124h
      reg[128h] = firmware[060h] ;W_CONFIG_128h
      reg[150h] = firmware[062h] ;W_CONFIG_150h

Init RF registers

      numbits = BYTE firmware[041h]    ;usually 18h
      numbytes = (numbits+7)/8         ;usually 3
      reg[0x184] = (numbits+80h) AND 017Fh  -- W_RF_CNT
      for i=0 to BYTE firmware[042h]-1 ;number of entries (usually 0Ch) (0..0Bh)
       if BYTE firmware[040h]=3
        RF[i]=firmware[0CEh+i]
       else
        RF_Write(numbytes at firmware[0CEh+i*numbytes])
       endif

Init the BaseBand System

      (this should be not required, already set by firmware bootcode)
      reg[160h] = 0100h  ;W_BB_MODE
      BB[0..68h] = firmware[64h+(0..68h)]

Set Mac address

      copy 6 bytes from firmware[036h] to mac address at 0x04800018  (why again ?)

Now just set some default variables

      reg[02Ch]=0007h  ;W_TX_RETRYLIMIT - XXX needs to be set for every transmit?
      Set channel (see section on changing channels)
      Set Mode 2 -- sets bottom 3 bits of W_MODE_WEP to 2
      Set Wep Mode / key -- Wep mode is bits 3..5 of W_MODE_WEP
      BB[13h] = 00h  ;CCA operation (use only carrier sense, without ED)
      BB[35h] = 1Fh  ;Energy Detection Threshold (ED)

-- To further init wifi to the point that you can properly send
-- and receive data, there are some more variables that need to be set.

      reg[032h] = 8000h -- W_WEP_CNT     ;Enable WEP processing
      reg[134h] = FFFFh -- W_BEACONCOUNT2;reset post-beacon counter to LONG time
      reg[028h] = 0000h -- W_AID_LOW     ;\clear W_AID value, again?!
      reg[02Ah] = 0000h -- W_AID_FULL    ;/
      reg[0E8h] = 0001h -- W_US_COUNTCNT ;enable microsecond counter
      reg[038h] = 0000h -- W_POWER_TX    ;disable transmit power save
      reg[020h] = 0000h -- W_BSSID_0     ;\
      reg[022h] = 0000h -- W_BSSID_1     ; clear BSSID
      reg[024h] = 0000h -- W_BSSID_2     ;/

-- TX prepare

      reg[0AEh] = 000Dh -- W_TXREQ_SET   ;flush all pending transmits (uh?)

-- RX prepare

      reg[030h] = 8000h    W_RXCNT         ;enable RX system (done again below)
      reg[050h] = 4C00h    W_RXBUF_BEGIN   ;(example values)
      reg[052h] = 5F60h    W_RXBUF_END     ;(length = 4960 bytes)
      reg[056h] = 0C00h/2  W_RXBUF_WR_ADDR ;fifo begin latch address
      reg[05Ah] = 0C00h/2  W_RXBUF_READCSR     ;fifo end, same as begin at start.
      reg[062h] = 5F60h-2  W_RXBUF_GAP     ;(set gap<end) (zero should work, too)
      reg[030h] = 8001h    W_RXCNT  ;enable, and latch new fifo values to hardware

--

      reg[030h] = 8000h    W_RXCNT       enable receive (again?)
      reg[010h] = FFFFh    W_IF          clear interrupt flags
      reg[012h] = whatever W_IE          set enabled interrupts
      reg[1AEh] = 1FFFh    W_RXSTAT_OVF_IE desired STAT Overflow interrupts
      reg[1AAh] = 0000h    W_RXSTAT_INC_IE desired STAT Increase interrupts
      reg[0D0h] = 0181h    W_RXFILTER set to 0x581 when you successfully connect
                            to an access point and fill W_BSSID with a mac
                            address for it. (W_RXFILTER) [not sure on the values
                            for this yet]
      reg[0E0h] = 000Bh  -- W_RXFILTER2     ;
      reg[008h] = 0000h  -- ? W_TXSTATCNT   ;(again?)
      reg[00Ah] = 0000h  -- ? W_X_00Ah      ;(related to rx filter) (again?)
      reg[004h] = 0001h  -- W_MODE_RST      ;hardware mode
      reg[0E8h] = 0001h  -- W_US_COUNTCNT   ;enable microsecond counter (again?)
      reg[0EAh] = 0001h  -- W_US_COMPARECNT ;enable microsecond compare
      reg[048h] = 0000h  -- W_POWER_?    ;[disabling a power saving technique]
      reg[038h].Bit1 = 0 -- W_POWER_TX   ;[this too]
      reg[048h] = 0000h  -- W_POWER_?    ;[umm, it's done again. necessary?]
      reg[0AEh] = 0002h  -- W_TXREQ_SET  ;
      reg[03Ch].Bit1 = 1 -- W_POWERSTATE ;queue enable power (RX power, we believe)
      reg[0ACh] = FFFFh  -- W_TXREQ_RESET;reset LOC1..3

That's it, the DS should be now happy to send and receive packets.
It's very possible that there are some unnecessary registers set in here.

DS Wifi Flowcharts

Wifi Transmit Procedure
To transmit data via wifi (Assuming you've already initialized wifi and changed channels to the channel you want):

     (1) Copy the TX Header followed by the 802.11 packet to send anywhere it
          will fit in MAC memory (halfword-aligned)
     (2) Take the offset from start of MAC memory that you put the packet,
          divide it by 2, and or with 0x8000 - store this in one of the
          W_TXBUF_LOC registers
     (3) Set W_TX_RETRYLIMIT, to allow your packet to be retried until an ack is
          received (set it to 7, or something similar)
     (4) Store the bit associated with the W_TXBUF_LOC register you used
          into W_TXREQ_SET - this will send the packet.
     (5) You can then read the result data in W_TXSTAT when the TX is over
          (you can tell either by polling or interrupt) to find out how many
          retries were used, and if the packet was ACK'd

Of course, this is just the simplest approach, you can be a lot more clever about it.
Wifi Receive Procedure
To receive data via wifi, you either need to handle the wifi received data interrupt, or you need to poll W_RXBUF_WRCSR - whenever it is != W_RXBUF_READCSR, there is a new packet. When there is a new packet, take the following approach:

     (1) Calculate the length of the new packet (read "received frame length"
          which is +8 bytes from the start of the packet) - total frame length
          is (12 + received frame length) padded to a multiple of 4 bytes.
     (2) Read the data out of the RX FIFO area (keep in mind it's a circular
          buffer and you may have to wrap around the end of the buffer)
     (3) Set the value of W_RXBUF_READCSR to the location of the next packet
          (add the length of the packet, and wrap around if necessary)

Keep in mind, W_RXBUF_READCSR and W_RXBUF_WRCSR must be multiplied by 2 to get a byte offset from the start of MAC memory.
Wifi Change Channels Procedure (ch=1..14)
For Type2 or Type5 (ie. firmware[040h]<>3): ;(Type2, used in Original-DS)

      RF[firmware[F2h+(ch-1)*6]/40000h] = firmware[F2h+(ch-1)*6] AND 3FFFFh
      RF[firmware[F5h+(ch-1)*6]/40000h] = firmware[F5h+(ch-1)*6] AND 3FFFFh
      delay a few milliseconds  ;huh?
      IF RF[09h].bit16=0     ;External Gain (default)
       BB[1Eh]=firmware[146h+(ch-1)]                         ;set BB.Gain register
      ELSEIF RF[09h].bit15=0 ;Internal Gain from TXVGC Bits
       RF[09h].Bit10..14 = (firmware[154h+(ch-1)] AND 1Fh)   ;set RF.TXVGC Bits
      ENDIF

For Type3 (ie. firmware[040h]=3): ;(Type3, used in DS-Lite)

      num_initial_regs = firmware[042h]
      addr=0CEh+num_initial_regs
      num_bb_writes = firmware[addr]
      num_rf_writes = firmware[43h]
      addr=addr+1
      for i=1 to num_bb_writes
        BB[firmware[addr]] = firmware[addr+ch]
        addr=addr+15
      next i
      for i=1 to num_rf_writes
        RF[firmware[addr]] = firmware[addr+ch]
        addr=addr+15
      next i

Congrats, you are now ready to transmit/receive on whatever channel you picked.
Channels
The IEEE802.11b standard (and the NDS hardware) support 14 channels (1..14).
Channels 1..13 use frequencies 2412MHz..2472MHz (in 5MHz steps). Channel 14 uses frequency 2484MHz. Which channels are allowed to be used varies from country to country, as indicated by Bit1..14 of firmware[03Ch]. Channel 14 is rarely used (dated back to an older japanese standard).
Caution: Nearby channels do overlap, you'll get transmission errors on packets that are transferred simultaneously with packets on nearby channels. But, you won't successfully receive packets from nearby channels (so you won't even "see" that they are there, which is bad, as it doesn't allow you to share the channel synchronized with other hosts; ie. it'd be better if two hosts are using the SAME channel, rather than to use nearby channels).
To avoid that problem, conventionally only channels 1,6,11 are used - however Nintendo uses channels 1,7,13 - which is causing conflicts between channel 6,7, and maybe also between 11,13.

DS Wifi Hardware Headers

Hardware TX Header (12 bytes) (TXHDR)
The TX header immediately precedes the data to be sent, and should be put at the location that will be given to the register activating a transmission.

      Addr Siz Expl.
      00h  2   Status - In: Don't care - Out: Status (0000h=Failed, 0001h=Okay)
      02h  2   Unknown - In: Don't care
                 Bit0: Usually zero.
                 Bit1..15 --------> flags for multiboot slaves number 1..15
                 (Should be usually zero, except when sending multiplay commands
                 via W_TXBUF_CMD. In that case, the slave flags should be ALSO
                 stored in the second halfword of the FRAME BODY. Actually, the
                 hardware seems to use only that entry (in the BODY), rather than
                 using this entry (in the hardware header)).
      04h  1   Unknown - In: Must be 00h..02h (should be 00h)
                 (03h..FFh result in error: W_TXSTAT.Bit1 gets set, but
                 nethertheless header entry[00h] is kept set to 0001h=Okay)
                 ;00h = use W_TX_SEQNO (if enabled in TXBUF_LOCn)
                 ;01h = force NOT to use W_TX_SEQNO (even if it is enabled in LOCn)
                 ;02h = seems to behave same as 01h
      05h  1   Unknown - In: Don't care - Out: Set to 00h
      06h  2   Unknown - In: Don't care
      08h  1   Transfer Rate (0Ah=1Mbit/s, 14h=2Mbit/s) (other values=1MBit/s, too)
      09h  1   Unknown - In: Don't care
      0Ah  2   Length of IEEE Frame Header+Body+checksum(s) in bytes
               (14bits, upper 2bits are unused/don't care)

The eight "Don't care" bytes should be usually set to zero (although setting them to FFh seems to be working as well). Entries [00h] and [05h] are modified by hardware, all other entries are kept unchanged.
Important note! TX length includes the length of a 4-byte "FCS" (checksum) for the packet. The hardware generates the FCS for you, but you still must include it in the packet length. Also note that if the 802.11 WEP enabled bit is set in the header, the packet will be automatically encrypted via the wep algorithm - however, the software is responsible for providing the 4-byte IV block with the WEP key ID and the 24bit IV value. - ALSO, you must include the length of the *encrypted* FCS used in packets that have wep enabled (increase the tx length by another 4 bytes) - this value is calculated automaticly for you, but you are responsible for including it in the length of your packet (if you have data there, it'll be replaced by the FCS.)
Hardware RX Header (12 bytes) (RXHDR)
The RX header is an informational structure that provides needed information about a received packet. It is written right before the received packet data in the rx circular buffer.

      Addr Siz Expl.
      00h  2   Flags
                 Bit0-3: Frame type/subtype:
                   0  managment/any frame (except beacon and invalid subtypes)
                   1  managment/beacon frame
                   5  control/ps-poll frame
                   8  data/any frame (subtype0..7) (ie. except invalid subtypes)
                   C,D,E,F  unknown (firmware is checking for that values)
                   ---
                   C    firmware uses it for data/cf-poll frame, FromDs (*)
                   D    firmware uses it for data/cf-ack frame, FromDs
                   E,F  firmware uses it for data/cf-ack frame, ToDs
                   (*) with DA=broadcast
                   ---
                 Bit4:   Seems to be always set
                 Bit5-7: Seems to be always zero
                 Bit8: Set when FC.Bit10 is set (more fragments)
                 Bit9: Set when the lower-4bit of Sequence Control are nonzero,
                       it is also set when FC.Bit10 is set (more fragments)
                       So, probably, it is set on fragment-mismatch-errors
                 Bit10-14: Seems to be always zero
                 Bit15: Set when Frame Header's BSSID value equals W_BSSID register
      02h  2   Unknown (usually 0040h)
      04h  2   Time since last packet (eg. when receiving beacons: total random on
                first some packets, but later on it gets equal to Beacon Interval)
                In other cases, this value is equal to the 1st 2 bytes of the DA ?
                [Above time/da effects might be explained by other reason: maybe
                this entry is left unchanged, simply containing old WifiRAM value?]
      06h  2   Transfer Rate (N*100kbit/s) (ie. 14h for 2Mbit/s)
      08h  2   Length of IEEE Frame Header+Body in bytes (excluding FCS checksum)
      0Ah  1   MAX RSSI   ;\Received Signal Strength Indicator
      0Bh  1   MIN RSSI   ;/

Important Note: Received frame lengths are always multiples of 4 bytes. While the actual header length + received frame length may be less, when incrementing the read cursor you must pad the length to a multiple of 4 bytes.
IEEE Header
The above Hardware headers should (must) be followed by valid IEEE headers. Although that headers are to be generated by software, the hardware does do some interaction with the IEEE headers, such like comparing address fields with W_MACADDR and W_BSSID. And, it does modify some entries of it:
1) The sequence control value is replaced by W_TX_SEQNO*10h (when enabled in W_TXBUF_LOCn.Bit13), this replacement does also overwrite the local TXBUF value.
2) The frame control value is modified, namely, the hardware tends to set Bit12 of it. This replacement does NOT modify the local TXBUF, but the remote RXBUF will receive the modified value. Also, Bit0-1 (protocol version) are forcefully set to 0.
3) Transmits via W_TXBUF_BEACON do additionally modify the 64bit timestamp (so W_TXBUF_BEACON should be used ONLY for packets WITH timestamp, ie. Beacons or Probe-Responses). The local TXBUF seems to be left unchanged, but the remote RXBUF will contain the (sender's) W_US_COUNT value.
C) For Control Frames, the hardware headers Length value is transferred as normally (ie. excluding the FCS length, remote RXBUF will contain TXBUF length minus 4), but - no matter of that length value - only 10 or 16 bytes (depending on the subtype) of the IEEE frame are actually transferred and/or stored in RXBUF.
X) For Control Frames with Subtype 0Ah, the AID entry is set to C000h, that, probably ORed with original value in WifiRAM, or with the W_AID_FULL register?
XX) No idea if it's possible to send Control Frames with subtype 0Bh..0Fh, as for now, it seems that either they aren't sent, or the receipient is ignoring them (or processing them internally, but without storing them in RXBUF).

DS Wifi Nintendo Beacons

Available Game Advertisement
WMB uses beacon frames to advertise available games for download. The beacon frames are normally used to advertise available access points in most 802.11 systems, but there is nothing preventing their use in this capacity. The advertisement data is fragmented and stored partially in each beacon frame as the payload of a custom information element (tag: 0xDD).
The DS Download Play menu only lists games when the beacons are broadcasted on one of the following channels: 1, 3, 4, 5, 7, 9, 10, 11, 13, and 14 (that is WRONG, firmware_v3 checks only channels 1,7,13). However, the DS hosting mechanism only seems to transmit on channels 1, 7, and 13 (apparently selected at random).
All beacon frames transmitted by a DS host have the following format

      802.11 management frame
      802.11 beacon header (Timestamp,BeaconInterval,Capability?)
      Supported rates (tagged IE, advertises 1 Mbit and 2 Mbit)
      DS parameter set (tagged IE, note: Distribution System, not Nintendo DS)
      TIM vector (tagged IE, transmitted as empty)
      Custom extension (tagged IE, tag DDh, see below)

Nintendo specific beacon fragment format (information element code DDh)

      Offset Description
      00h  Nintendo Beacon OUI (00h,09h,BFh,00h)
      04h  Stepping Offset for 4808134h/W_BEACONCOUNT2 (always 000Ah)
      06h  Strange Timestamp (W_US_COUNT*2-VCOUNT*7Fh)/128 (0000h for multiboot)
      08h  01 00
      0Ah  40 00
      0Ch  24 00
      0Eh  40 00
      10h  Randomly generated stream code
      12h  Number of bytes from entry 18h and up (70h for multiboot) (0 if Empty)
      13h  Beacon Type    (0Bh=Multiboot, 01h=Multicart/Pictochat, 09h=Empty)
      14h  0100 0008    (some kind of max,min values?)

For Empty (length zero, is used at very begin of multiboot)

      18h  No data.

For Multicart (variable length)

      18h  Custom data, usually containing the host name, either in 8bit ascii,
           or 16bit unicode format. Sometimes taken from Firmware User Settings,
           and sometimes from Cartridge Backup Memory.

For Pictochat (length 8)

      18h  Fixed (always 2348h)
      1Ah  xxxx
      1Ch  Chatroom number (00h..03h for Chatroom A..D)
      1Dh  Number of users already connected (01h..10h) (including host)
      1Eh  Fixed (always 0004h)

For Multiboot (always 70h bytes)

      18h  24 00 40 00 (varies from game to game)
      1Ch  End of advertisement flag (00 for non-end, 02 for end packets)
      1Dh  Always 00, 01, 02, or 04
      1Eh  Number of players already connected
      1Fh  Sequence number (0 .. total_advertisement_length)
      20h  Checksum (on entries 22h and up)
             chksum=0, for i=22h to 86h step 2, chksum=chksum+halfword[i], next i,
             chksum=FFFFh AND NOT (chksum+chksum/10000h)
      22h  Sequence number in non-final packet, # of players in final packet
      23h  Total advertisement length - 1 (in beacons)
      24h  Datasize in bytes (2 byte little-endian)
               (0062h for seq 0..7, 0048h for seq 8, 0001h for seq 9)
      26h  Data (always 62h bytes, padded with 00h if Datasize<62h)

Multiboot Advertisement Fragments
The advertisement fragments are reordered and assembled according to their internal sequence number, to form the overall advertisement payload, as defined below:

      Offset Size Description
      000h  32  Icon Palette (same as for ROM Cartridge Icon)
      020h  512 Icon Bitmap  (same as for ROM Cartridge Icon)
      220h  1   Unknown (0Bh)
      221h  1   Length of hosting name          ;(probably same as firmware
      222h  20  Name of hosting DS (10 UCS-2)   ;user name?)
      236h  1   Max number of players
      237h  1   Unknown (00h)
      238h  96  Game name (48 UCS-2)   (same as 1st line of ROM Cartridge Title)
      298h  192 Description (96 UCS-2) (same as further lines of ROM Cart Title)
      358h  64  00's if no users are connected  <---WRONG: LEN=1, not 64
      398h  0   End of data if no users are connected

Authentication process
Once a user B chooses a download offered by a host A, the following standard 802.11 authentication process observed.

      Host A advertises a game in beacon frames as described above
      Client B sends an authentication request (sequence 1) to A    ;\step 1
      Host A replies with an ACK                                    ;/
      Host A sends an authentication reply (sequence 2) to B        ;\step 2
      (uh, no ACK here?)                                            ;/
      Client B sends an association request                         ;\step 3
      Host A replies with an ACK                                    ;/
      Host A sends an association response                          ;\step 4
      Client B replies with an ACK                                  ;/

After this, the two are associated, and will remain so until the transfer is complete or one is idle for several seconds, at which point they will de-associate. For more information on the association process, see the 802.11 standard.

DS Wifi Nintendo DS Download Play

Before downloading: Receive beacons, display Icon/Title, prompt user whether to download that title, and, if so, connect to host (via authentication and association requests). See previous chapter for details.
Download process (after authentication)

      Host sends some Pings, client(s) send PongReplies
      Host sends more Pings, client(s) send UsernameReplies
      Host sends RSA frame, client(s) send RsaReply
      Host sends NDS header, client(s) send DataReply
      Host sends ARM9 binary, client(s) send DataReply
      Host sends ARM7 binary, client(s) send DataReply
      Host sends Done message, no reply from client(s)

The WMB protocol implements layers 3 to 7 of the OSI network model, but does not define a new type of network addresses. However, it does define a couple of special broadcast-like MAC addresses within the assigned Nintendo namespace (00:09:BF:xx:xx:xx).
Flows
The three channels or "flows" used for all communications after the MAC broadcast beacons take the form 03:09:BF:00:00:xx:

      03:09:BF:00:00:00  host to client main data flow ;via 4808090h/W_TXBUF_CMD
      03:09:BF:00:00:10  client to host replies        ;via 4808094h/W_TXBUF_REPLY1
      03:09:BF:00:00:03  host to client feedback flow  ;acknowledges the replies?

The host does something unusual with the 802.11 sequence control field, each packet sent out on the 03:09:BF:00:00:00 flow has a sequence control number 2 greater than the previous one, even if they are sent sequentially. When the host acknowledges a reply (on flow 03:09:BF:00:00:03) from the client about a particular packet, it uses the sequence number one after the original packet number it sent out on 00. This is the root of one of the major problems in finding a PC card that can transmit WMB packets, as very few cards provide user control over it. Even when a card is capable of 'raw' 802.11 transmission, it typically takes care of the sequence control field in hardware or firmware, filling it with a constantly incrementing number.
Host-to-client packets (on the 03:09:BF:00:00:00 flow)
Sent via via 4808090h/W_TXBUF_CMD (multiplayer master)

      00h 2   Value for W_CMD_REPLYTIME (0106h)
      02h 2   Slave Flags, bit1..15 for slave 1..15 (1=connected) (eg. 0002h)
      04h 1   Size in halfwords
      05h 1   Flags
      06h 1   Command (01h=Ping/NameRequest, 03h=RSA, 04h=DataPacket, 05h=Done)
     For Command 01h (Ping):                               ;\
      07h 4   Unused (zerofilled)                          ;
     For Command 03h (RSA):                                ;
      07h E0h RSA Signature Frame (see below)              ; Payload
     For Command 04h (Data Packet):                        ;
      07h 1   Unknown (zero)                               ;
      08h 2   Packet Number (0000h and up)                 ;
      0Ah ..  Data                                         ;
     For Command 05h (Done):                               ;
      07h ..  Unknown                                      ;/
     For all commands (whatever trailing three bytes):
      xxh 3   Unknown (00h,02h,00h)

The size field is in terms of half-words (16 bits), and includes the flags byte along with the payload (so a size of 0x03 represents a flag byte, a command byte, and 4 bytes of payload).
When flags is 0x11, the first byte of the payload is a command. There seems to be no important data when flags is not 0x11 (seen occasionally as 0x01), and ignoring them still results in a complete dump.
Data packets (type 0x04) include a transport-layer sequence number inside of the data packet itself, but no destination offset or other mechanism to allow the packets to be processed out-of-order. The only way to place the data at the correct location in memory is to re-order the packets according to the sequence number and process them sequentially. The sequence number is a zero based little-endian number. Each packet only contains data for one of the three destination blocks (header, ARM9, ARM7), so the change-of-destination check only needs to be made on packet boundaries.
Client to Host Replies (on the 03:09:BF:00:00:10 flow)
Sent via 4808094h/W_TXBUF_REPLY1 (multiplayer slave)
The client uses an incrementing sequence control number for all of its packets, with no unusual trickery. Each reply is sent as a standard 802.11 data frame (typically as a Data + CF-Acknowledgement), consisting of ten data bytes:

      00h 2  Unknown/fixed (8104h)
      02h 1  Reply Type (00h=Pong, 07h=Username, 08h=RsaReply, 09h=DataReply)
     For Reply Type 00h (PongReply):
      03h 7  Unused (zerofilled)
     For Reply Type 07h (UsernameReply):
      03h 1  Username fragment (01h..04h)
      04h 6  Username Char[0,1,2]                    ;for fragment 01h
      04h 6  Username Char[3,4,5]                    ;for fragment 02h
      04h 6  Username Char[6,7,8]                    ;for fragment 03h
      04h 6  Username Char[9], bytes 01h,00h,00h,00h ;for fragment 04h
     For Reply Type 08h (RsaReply):
      03h 7  Unused (garbage, usually same as Name fragment 02h)
     For Reply Type 09h (DataReply):
      03h 2  Last packet (the packet number being acknowledged)
      05h 2  Best packet (the highest continuous packet number seen so far)
      07h 3  Unused (zerofilled)

The NameReply is sent shortly after association is completed, although I am not certain what triggers it. There are a variable number of Pings preceding this reply, but most are replied via Pongs. The name reply sends the user-configured DS name (set in the firmware menu) split over four messages (with the 4th byte of the packet specifying which message fragment this is, 1 based). This can be a total length of 10 UCS-2 characters, although all four messages are still sent if it is shorter (padded with nulls to 10 characters, and then 01 and then nulls until the end of the frame).
Host to client acknowledgements (on the 03:09:BF:00:00:03 "feedback" flow)
Sent via UNKNOWN which port sends this?
Maybe "second half" of W_TXBUF_CMD? Or hardware auto-sends this as "ack"?

      00h 1  Unknown (random/garbage?) (unknown value... maybe per slave flags?)
      01h 3  Unused (zerofilled)

These packets contain four data bytes, but three are always zero. The first seems to be random, with no connection to the acknowledged data. The actual indication of acknowledgement is the sequence control number of the packet. It is set to be one greater than the sequence control number of the initial host packet (sent on flow 03:09:BF:00:00:00) that the client has just responded to, to indicate that the reply was received.
RSA signature frame payload (type 0x03)
The RSA frame format (type 0x03) sends a table of information about the game being downloaded (most of it redundant with the NDS header), as well as the RSA signature for the DS.
Notably: the RSA frame itself is not included as part of the data being signed, bringing up various security issues and making Nintendo's firmware engineers look amateurish at best.
There are several abortive sendings of empty RSA frames with a size field of 0x03, before the real frame is sent (always with a size field of 0x75).

      00h 4   ARM9 execute address
      04h 4   ARM7 execute address
      08h 4   Zerofilled
      0Ch 4   Header destination (temp)
      10h 4   Header destination (actual)
      14h 4   Header size (160h)
      18h 4   Zerofilled
      1Ch 4   ARM9 destination address (temp)
      20h 4   ARM9 destination address (actual)
      24h 4   ARM9 binary size
      28h 4   Zerofilled
      2Ch 4   ARM7 destination address (temp) (usually 22C0000h in Main RAM)
      30h 4   ARM7 destination address (actual) (usually somewhere in WRAM)
      34h 4   ARM7 binary size
      38h 4   Unknown (00000001h)
      3Ch 4   Signature ID (61h,63h,01h,00h) (aka "ac", or backwards "ca") ;\
      40h 80h Signature RSA (RSA signature in OpenPGP SHA1 format)         ;
      C0h 4   Signature Footer                                             ;/
      C4h 36  Zerofilled
      E8h -   End of frame payload

The offsets in the table are from after the command byte, ie. two bytes into the 234 bytes of payload including the flags.
The temp/actual destination addresses are usually identical, except for ARM7 which is loaded to a separate temp address in Main RAM (needed there for computing its SHA1 on ARM9 side).
The RSA signature is as so: First compute SHA1's on Header and ARM9 and ARM7 areas, and store them in a 40h-byte array:

      00h 14h SHA1 on Header
      14h 14h SHA1 on ARM9 bootcode
      28h 14h SHA1 on ARM7 bootcode
      3Ch 4   Signature Footer (the four bytes from [C0h])

Then compute a SHA1 on that 40h-byte array, that SHA1 value is then used in the RSA signature (in OpenPGP SHA1 format, ie. same as SWI 23h in DSi BIOS). The RSA private key is unknown, the RSA public key (9Eh,C1h,CCh,C0h,...) can be found in the NDS Firmware and in the DSi's DS Download Play utility.
Unknown if the 4-byte Footer value is having any special meaning (eg. it might be some checksum, or it might be just some random/timestamp).
The 4+80h+4 signature bytes at [3Ch..C3h] are conventionally stored at the "end" of the binary, ie. at the offset specified in cartheader[080h].
NDS format
The .NDS format is the standard format for Nintendo DS programs; it originated on original game cards and also appears to a limited extent in WMB binaries. The WMB process only transfers the first 0x160 bytes of the header, the ARM9 binary, and the ARM7 binary (in that order), ignoring the file name and file allocation tables, the overlay data, and some information stored in the banner (the rest is transmitted partially via the beacon advertisement process).
List of DS Download Play Games
Games with DS Download Play Support (single-cart multiplayer):

      Over the Hedge (download contains a 2D minigame)

Demos available from DS Download Stations:

      Eragon
      Lara Croft Tomb Raider Legend
      Magnetica
      Metroid Prime Hunters Demo
      Submarine Tech Demo
      (and many trailers with non-playable movie clips)

DS Wifi IEEE802.11 Frames

MAC Frame Format

      10..30 bytes    MAC Header
      0..2312 bytes   Frame Body (in practice, network MTU is circa 1500 bytes max)
      4 bytes         Frame Check Sequence (FCS) (aka checksum)

MAC Header (10..30 bytes)

      Size Content
      2    Frame Control Field (FC)
      2    Duration/ID
      6    Address 1
     (6)   Address 2 (if any)
     (6)   Address 3 (if any)
     (2)   Sequence Control (if any)
     (6)   Address 4 (if any)

Frame Control Field (FC)

      Bit  Expl.
      0-1  Protocol Version   (0=Current, 1..3=Reserved)
      2-3  Type               (0=Managment, 1=Control, 2=Data, 3=Reserved)
      4-7  Subtype            (see next chapters) (meaning depends on above Type)
      8    To Distribution System (DS)
      9    From Distribution System (DS)
      10   More Fragments
      11   Retry
      12   Power Managment    (0=Active, 1=STA will enter Power-Safe mode after..)
      13   More Data
      14   Wired Equivalent Privacy (WEP) Encryption (0=No, 1=Yes)
      15   Order

Bit 8-11 and Bit 13-15 are always 0 in Control Frames.
Duration/ID Field (16bit)

      0000h..7FFFh  Duration (0-32767)
      8000h         Fixed value within frames transmitted during the CFP
                    (CFP=Contention Free Period)
      8001h..BFFFh  Reserved
      C000h         Reserved
      C001h..C7D7h  Association ID (AID) (1..2007) in PS-Poll frames
      C7D8h..FFFFh  Reserved

48bit MAC Addresses
MAC Addresses are 48bit (6 bytes) (Bit0 is the LSB of the 1st byte),

      0     Group Flag (0=Individual Address, 1=Group Address)
      1     Local Flag (0=Universally Administered Address, 1=Locally Administered)
      2-23  22bit Manufacturer ID (assigned by IEEE)
      24-47 24bit Device ID (assigned by the Manufacturer)

Special NDS related Addresses:

      00 09 BF xx xx xx  NDS-Consoles (Original NDS with firmware v1-v5)
      00 16 56 xx xx xx  NDS-Consoles (Newer NDS-Lite with firmware v6 and up)
      00 23 CC xx xx xx  DSi-Consoles (Original DSi with early mainboard; nocash)
      00 24 1E xx xx xx  DSi-Consoles (Another DSi; scanlime)
      40 F4 07 xx xx xx  DSi-Consoles (with DWM-W024; nocash)
      E0 E7 51 xx xx xx  DSi-Consoles (with DWM-W024; nocash/desoldered)
      CC 9E 00 xx xx xx  DSi-Consoles (with J27H020; nocash)
      03 09 BF 00 00 00  NDS-Multiboot: host to client (main data flow)
      03 09 BF 00 00 10  NDS-Multiboot: client to host (replies)
      03 09 BF 00 00 03  NDS-Multiboot: host to client (acknowledges replies)
      FF FF FF FF FF FF  Broadcast to all stations (eg. Beacons)

Sequence Control Field

      Bit  Expl.
      0-3  Fragment Number (0=First (or only) fragment)
      4-15 Sequence Number

(increment by 1, except on retransmissions, ie. retries)
WEP Frame Body

      3 bytes     Initialization Vector (WEP IV)
      1 byte      Pad (6bit, all zero), Key ID (2bit)
      1..? bytes  Data (encrypted data)
      4 bytes     ICV (encrypted CRC32 across Data)

DS Wifi IEEE802.11 Managment Frames (Type=0)

All Managment Frames have 24-byte Frame Header, with following values:

      FC(2), Duration(2), DA(6), SA(6), BSSID(6), Sequence Control(2)

The content of the Frame Body depends on the FC's Subtype:

      Subtype                   Frame Body
      0 Association request     Capability, ListenInterval, SSID, SuppRates
      1 Association response    Capability, Status, AID, SuppRates
      2 Reassociation request   Capability, ListenInterval, CurrAP, SSID, SuppRates
      3 Reassociation response  Capability, Status, AID, SuppRates
      4 Probe request           SSID, SuppRates
      5 Probe response          Same as for Beacon (but without TIM)
      8 Beacon                  Timestamp,BeaconInterval,Capability,SSID,SuppRates,
                                 FH Parameter Set (when using Frequency Hopping),
                                 DS Parameter Set (when using Direct Sequence),
                                 CF Parameter Set (when supporting PCF),
                                 IBSS Parameter Set (when in an IBSS),
                                 TIM (when generated by AP)
      9 Announcement traffic indication message (ATIM)    Body is "null" (=none?)
      A Disassociation          ReasonCode
      B Authentication          AuthAlgorithm, AuthSequence, Status, ChallengeText
      C Deauthentication        ReasonCode

Subtypes 6..7, and D..F are Reserved.
The separate components of the Frame Body are...
64bit Parameters (8 bytes)

      Timestamp: value of the TSFTIMER (see 11.1) of a frame's source. Uh?

48bit Parameters (6 bytes)

      Current AP (Access Point): MAC Address of AP with which station is associated

16bit Parameters (2 bytes)

      Capability Information (see list below)
      Status code (see list below) (0000h=Successful, other=Error code)
      Reason code (see list below) (Error code)
      Association ID (AID) (C000h+1..2007)
      Authentication Algorithm (0=Open System, 1=Shared Key, 2..FFFFh=Reserved)
      Authentication Transaction Sequence Number (Open System:1-2, Shared Key:1-4)
      Beacon Interval (Time between beacons, N*1024 us)
      Listen Interval (see note below)

Information elements (1byte ID, 1byte LEN, followed by LEN byte(s) data)

      ID      LEN      Expl.
      00h     00h-20h  SSID Service Set Identity (LEN=0 for broadcast SSID) (ASCII)
      01h     01h-08h  Supported rates; each (nn AND 7Fh)*500kbit/s, bit7=flag
      02h     05h      FH (Frequency Hopping) Parameter Set
                         DwellTime(16bit), HopSet, HopPattern, HopIndex
      03h     01h      DS (Distribution System) Parameter Set; Channel (01h..0Eh)
      04h     06h      CF Parameter Set; Count, Period, MaxDuration, RemainDuration
      05h     04h..FEh TIM; Count,Period,Control, 1-251 bytes PartialVirtualBitmap
      06h     02h      IBSS Parameter Set; ATIM Window length (16bit)
      07h-0Fh -        Reserved
     (07h)    ..       802.11d Country
     (08h)    ..       802.11d Hopping Pattern Params
     (09h)    ..       802.11d Hopping Pattern Table
     (0Ah)    ..       802.11d Request
      10h     02h..FEh Challenge text; 1-253 bytes Authentication data
                        (Used only for Shared Key sequence no 2,3)
                        (none such for Open System)
                        (none such for Shared key sequence no 1,4)
      11h-1Fh -        Reserved for challenge text extension
      20h-FFh -        Reserved
     (20h)    ..       802.11h Power Constraint
     (21h)    ..       802.11h Power Capability
     (22h)    ..       802.11h TPC Request (Transmit Power Control)
     (23h)    ..       802.11h TPC Report
     (24h)    ..       802.11h Supported Channels
     (25h)    ..       802.11h Channel Switch Announcement
     (26h)    ..       802.11h Measurement Request
     (27h)    ..       802.11h Measurement Report
     (28h)    ..       802.11h Quiet
     (29h)    ..       802.11h IBSS DFS
      2Ah     ..       802.11g ERP Information (spotted in newer beacons)
      30h     var      802.11i Reserved but used for WPA2 RSNIE <-- officially
      32h     ..       802.11g Extended Supported Rates (spotted in newer beacons)
      DDh     var      Reserved but used for WPA RSNIE  <-- vendor specific
      DDh     var      Reserved but used by Nintendo for NDS-Multiboot beacons
      2Dh     ..       Unknown (spotted in newer beacons)
      2Fh     ..       Unknown (spotted in newer beacons)
      3Dh     ..       Unknown (spotted in newer beacons)
      7Fh     ..       Unknown (spotted in newer beacons)

IDs 20h-FFh are commonly used; I've received values 2xh..3xh and DDh (from non-nintendo network routers in the neighborhood); no idea if these "Reserved" IDs are somewhere officially documented?
Capability Information

      Bit0    ESS
      Bit1    IBSS
      Bit2    CF-Pollable
      Bit3    CF-Poll Request
      Bit4    Privacy
      Bit5    Short Preamble  (IEEE802.11b only)
      Bit6    PBCC            (IEEE802.11b only)
      Bit7    Channel Agility (IEEE802.11b only)
      Bit5-7  Reserved (0) (original IEEE802.11 specs)
      Bit8-15 Reserved (0)

Listen Interval

      ... used to indicate to the AP how often an STA wakes to listen to Beacon
      management frames. The value of this parameter is the STA's Listen Interval
      parameter of the MLME-Associate. request primitive and is expressed in
      units of Beacon Interval.

Reason codes

      00h Reserved
      01h Unspecified reason
      02h Previous authentication no longer valid
      03h Deauthenticated because sending station is leaving (or has left) IBSS
           or ESS
      04h Disassociated due to inactivity
      05h Disassociated because AP is unable to handle all currently associated
           stations
      06h Class 2 frame received from nonauthenticated station
      07h Class 3 frame received from nonassociated station
      08h Disassociated because sending station is leaving (or has left) BSS
      09h Station requesting (re)association is not authenticated with responding
           station
      0Ah..FFFFh Reserved

Status codes

      00h Successful
      01h Unspecified failure
      02h..09h Reserved
      0Ah Cannot support all requested cap's in the Capability Information field
      0Bh Reassociation denied due to inability to confirm that association exists
      0Ch Association denied due to reason outside the scope of this standard
      0Dh Responding station doesn't support the specified authentication algorithm
      0Eh Received an Authentication frame with authentication transaction sequence
           number out of expected sequence
      0Fh Authentication rejected because of challenge failure
      10h Authentication rejected due to timeout waiting for next frame in sequence
      11h Association denied because AP is unable to handle additional associated
           stations
      12h Association denied due to requesting station not supporting all of the
           data rates in the BSSBasicRateSet parameter
      13h Association denied due to requesting station not supporting
           the Short Preamble option (IEEE802.11b only)
      14h Association denied due to requesting station not supporting
           the PBCC Modulation option (IEEE802.11b only)
      15h Association denied due to requesting station not supporting
           the Channel Agility option (IEEE802.11b only)
      13h-15h Reserved (original IEEE802.11 specs)
      16h..FFFFh Reserved

DS Wifi IEEE802.11 Control and Data Frames (Type=1 and 2)

Control Frames (Type=1)
All Control Frames have 10-byte or 16-byte headers, depending on the Subtype:

      Subtype                          Frame Header
      0-9 Reserved                     -   -         -      -
      A   Power Save (PS)-Poll         FC  AID       BSSID  TA
      B   Request To Send (RTS)        FC  Duration  RA     TA
      C   Clear To Send (CTS)          FC  Duration  RA     -
      D   Acknowledgment (ACK)         FC  Duration  RA     -
      E   Contention-Free (CF)-End     FC  Duration  RA     BSSID
      F   CF-End + CF-Ack              FC  Duration  RA     BSSID

Control Frames do not have a Frame Body, so the Header is directly followed by the FCS.
Data Frames (Type=2)
All Data Frames consist of the following components:

      FC, Duration/ID, Address 1, Address 2, Address 3, Sequence Control,
      Address 4 (only on From DS to DS), Frame Body, FCS.

The meaning of the 3 or 4 addresses depends on Frame Control FromDS/ToDS bits:

      Frame Control    Address 1  Address 2  Address 3  Address 4
      From STA to STA  DA         SA         BSSID      -
      From DS  to STA  DA         BSSID      SA         -
      From STA to DS   BSSID      SA         DA         -
      From DS  to DS   RA         TA         DA         SA

Frame Control Subtypes for Data Frames (Type=2) are:

      0   Data
      1   Data + CF-Ack
      2   Data + CF-Poll
      3   Data + CF-Ack + CF-Poll
      4   Null function (no data)
      5   CF-Ack (no data)
      6   CF-Poll (no data)
      7   CF-Ack + CF-Poll (no data)
      8-F Reserved

Note: The Frame Header is 24 bytes (or 30 bytes if with Address 4). The Data in Frame Body is usually starting with LLC stuff, ie. AAh,AAh,03h,00h...

DS Wifi WPA/WPA2 Handshake Messages (EAPOL)

4-Way Handshake and Group Key Handshake messages
For WPA, the Group Key Handshake occurs immediately after the 4-way Handshake (effecitively making it a 6-way handshake). For WPA2, the Group Key is contained in the 4-way Handshake, so the Group Key Handshake isn't needed.
For both WPA and WPA2, the access point may change the Group Key every once and then, and invoke a new Group Key Handshake for the new key.
EAPOL Key Frame
This is preceeded by a LLC/SNAP header (AAh,AAh,03h,00h,00h,00h,88h,8Eh), the 888Eh in last two bytes indicates that following bytes to contain an EAPOL Key Frame:

      00h  2    Version/Type (or Type/Version?) (01 03)
      02h  2    Length of [04h..end] (005Fh+LEN)                      ;BIG-ENDIAN
      04h  1    Descriptor Type (FEh=WPA, 02h=WPA2)
      05h  2    Key Information (flags, see below)                    ;BIG-ENDIAN
      07h  2    Key Length (0=None, 20h=TKIP, 10h=CCMP, 05h/0Dh=WEP)  ;BIG-ENDIAN
      09h  8    Key Replay Counter (usually 0 or 1 in first message)  ;BIG-ENDIAN
      11h  32   Key Nonce (ANonce/SNonce)
      31h  16   Key Data IV (RC4 uses IV+KEK) (not used for AES-Key-Wrap)
      41h  8    Key RSC (TSC/PN) (whatever, for GTK)               ;LITTLE-ENDIAN
      49h  8    Reserved (zerofilled)
      51h  16   Key MIC on [00h..end] (with MIC initially zerofilled)       ;HMAC
      61h  2    Key Data Length (LEN) (00 nn)                         ;BIG-ENDIAN
      63h  LEN  Key Data (can be encrypted in certain messages)

Key Information flags

      0-2   Key Descriptor Version (1=WPA/MD5/RC4, 2=WPA2/SHA1/AESkeywrap)
      3     Key Type (0=Group, 1=Pairwise)
      4-5   Reserved (0) or WPA Group Key Index (1 or 2) (zero for WPA2)
      6     Install  (0=No, 1=Yes, configure temporal key)
      7     Key Ack  (0=No, 1=Yes, AP wants a reply; with same Key Replay Counter)
      8     Key MIC  (0=No, 1=Yes, key frame contains MIC)
      9     Secure   (0=No, 1=Yes, initial key-exchange complete)
      10    Error    (0=No, 1=Yes, MIC failure and Request=1)
      11    Request  (0=No, 1=Yes, request AP to invoke a new handshake)
      12    Encrypted(0=No, 1=Yes, Key Data is encrypted; via RC4 or AESkeywrap)
      13-15 Reserved (0)

Key Data
Key Data does usually consist of element(s) in following form:

      00h 1   Element ID (for WPA: DDh=RSNIE - for WPA2: 30h=RSNIE, DDh=KDE)
      01h 1   Element Length of [02h..end]
      02h ..  Element Data (OUI's etc.)

WPA and WPA2 assign different meanings to Element ID value DDh. The 3-byte maker prefix in OUI values does also differ for WPA/WPA2. And, the meaning of the OUI's varies depending on WHERE they are used (eg. 00-0F-AC-02 could be a Cipher Suite entry, or an Authentication entry):

      EAPOL Descriptor Type values
      WPA          WPA2         Meaning
      FEh          02h          Indicates if ElementIDs and OUIs are WPA or WPA2
      EAPOL Key Information flags/values
      0089h        008Ah        Handshake #1  ;\
      0109h        010Ah        Handshake #2  ; 4-way Handshake
      01C9h        13CAh        Handshake #3  ;
      0109h(again) 030Ah        Handshake #4  ;/
      0391h/03A1h  1382h        Handshake #5  ;\Group Key Handshake
      0311h/0321h  0302h        Handshake #6  ;/
      EAPOL Key Data Element IDs
      DDh          30h          Element ID for RSNIE (Robust Network Security info)
      -            DDh          Element ID for KDE (Key Data Encapsulation)
      -            DDh          Element ID for padding (followed by 00h-bytes)
      RSNIE Prefix OUI's (WPA only):
      00-50-F2-01  -            Element Vendor OUI for RSNIE
      RSNIE Group Cipher suite selector OUI's (aka Multicast):
      00-50-F2-01  00-0F-AC-01  RSNIE Group Cipher WEP-40  (default for US/NSA)
      00-50-F2-02  00-0F-AC-02  RSNIE Group Cipher TKIP    (default for WPA)
      00-50-F2-04  00-0F-AC-04  RSNIE Group Cipher CCMP    (default for WPA2)
      00-50-F2-05  00-0F-AC-05  RSNIE Group Cipher WEP-104 (default for WEP)
      RSNIE Pairwise Cipher suite selector OUI's (aka Unicast):
      00-50-F2-00  00-0F-AC-00  RSNIE Pairwise Cipher None (WEP, Group Cipher only)
      00-50-F2-02  00-0F-AC-02  RSNIE Pairwise Cipher TKIP (default for WPA)
      00-50-F2-04  00-0F-AC-04  RSNIE Pairwise Cipher CCMP (default for WPA2)
      RSNIE Authentication AKM suite selector OUI's :
      00-50-F2-01  00-0F-AC-01  RSNIE Authentication over IEEE 802.1X (radius?)
      00-50-F2-02  00-0F-AC-02  RSNIE Authentication over PSK (default/home use)
      KDE Key Data Encapsulation OUI's (WPA2 only):
      -            00-0F-AC-01  KDE GTK         (followed by 2+N bytes)
      -            00-0F-AC-02  KDE STAKey      (followed by 2+6+N bytes)
      -            00-0F-AC-03  KDE MAC address (followed by 6 bytes)
      -            00-0F-AC-04  KDE PMKID       (followed by 16 bytes)

RSNIE (Robust Network Security Information Element)
RSNIE allows to exchange information about the desired/supported encryption methods. RSNIE is found in handshake message 2/3 (and also in Beacons). In most cases one could just ignore the RSNIE stuff (eg. if Wifi FLASH is already configured to use a specific cipher type). A special case might be networks that use a weaker Group Cipher (for older devices) combined with offering stronger Pairwise Ciphers (for devices that support them).

      WPA2 RSNIE (Robust Network Security Information Element):
      00h  1  Element ID (30h=RSNIE for WPA2)
      01h  1  Element Len of [02h..end] (usually 14h)
      02h  2  RSNIE Version 1                        (01 00)     ;WHATEVER-ENDIAN?
      04h  4  RSNIE Group Cipher Suite OUI (CCMP)    (00 0F AC 04)
      08h  2  RSNIE Pairwise Cipher Suite Count (1)  (01 00)      ;LITTLE-ENDIAN
      0Ah  4  RSNIE Pairwise Cipher Suite OUI (CCMP) (00 0F AC 04)
      0Eh  2  RSNIE Authentication Count (1)         (01 00)      ;LITTLE-ENDIAN
      10h  4  RSNIE Authentication OUI (PSK)         (00 0F AC 02)
      14h  2  RSNIE Capabilities                     (00 00)      ;LITTLE-ENDIAN?
      16h (2) RSNIE Optional PMKID Count  ;\usually none such     ;LITTLE-ENDIAN
      18h (16)RSNIE Optional PMKID's      ;/
      WPA RSNIE (Robust Network Security Information Element):
      00h  1  Element ID (DDh=Vendor/RSNIE for WPA)
      01h  1  Element Len of [02h..end] (usually 16h or 18h)
      02h  4  Element Vendor OUI for RSNIE  (00 50 F2 01)       ;<-- WPA only
      06h  2  RSNIE Version value? (1)      (01 00)              ;WHATEVER-ENDIAN?
      08h  4  RSNIE Mcast OUI (TKIP)        (00 50 F2 02)
      0Ch  2  RSNIE Ucast Count (1)         (01 00)               ;LITTLE-ENDIAN
      0Eh  4  RSNIE Ucast OUI (TKIP)        (00 50 F2 02)
      12h  2  RSNIE Auth AKM Count (1)      (01 00)               ;LITTLE-ENDIAN
      14h  4  RSNIE Auth AKM OUI (PSK)      (00 50 F2 02)
      18h (2) RSNIE Capabilities maybe?     (00 00)               ;LITTLE-ENDIAN?
      RSN Capabilities flags (usually 0000h) (also spotted: 0C 00):
      0   RSN Pre-Auth capabilities
      1   RSN No Pairwise capabilities
      2-3 RSN PTKSA Replay Counters (0..3 = 1,2,4,16 replay counters)
      4-5 RSN GTKSA Replay Counters (0..3 = 1,2,4,16 replay counters)
      6   Managment Frame Protection Required
      7   Managment Frame Protection Capable
      8   Joint Multi-band RSNA
      9   PeerKey Enabled
      10  SPP A-MSDU Capable
      11  SPP A-MSDU Required
      12  PBAC
      13  Ext Key ID for Unicast
      14-15 Reserved (0)

KDE Key Data Encapsulation (or raw data for WPA)
KDE (or WPA's raw data) is mainly useful for transferring the GTK group key. Note that Key Data in WPA2 message 3 contains both RSNIE and KDE GTK (and KDE padding). Whilst the raw data in WPA cannot be mixed RSNIE.

      WPA2 KDE GTK (Key Data Encapsulation for Group Key, in encrypted Key Data):
      00h  1   Element ID (DDh=KDE for WPA2)
      01h  1   Element Len (16h)
      02h  4   KDE OUI GTK (00-0F-AC-01) (occurs in message 3/5)
      06h  1   KDE GTK Key ID (01h or 02h)      ;bit2: Tx ?
      07h  1   KDE GTK Reserved (00h)
      08h  16  KDE GTK Key GTK (for Key ID from above byte [06h])
      WPA2 KDE PKMID (Key Data Encapsulation for PKMID) (optional, not needed):
      00h  1   Element ID (DDh=KDE for WPA2)
      01h  1   Element Len (14h)
      02h  4   KDE OUI PMKID (00-0F-AC-04) (optionally occurs in message 1)
      06h  16  KDE PMKID (useless checksum on PMK, sometimes exposed in message 1)
      WPA2 KDE Padding (for padding Key Data to Nx8 bytes for AES-Key-wrap):
      00h  1   Element ID (DDh=KDE for WPA2)
      01h  0-6 Padding (00h) (aka Element Len=00h)
      WPA GTK (raw Group Key; without Element ID or KDE-style encapsulation):
      00h  16  Key GTK (for Key ID from Key Information bit4-5) (in message 5)

DS Wifi WPA/WPA2 Keys and MICs

Summary of WPA/WPA2 Keys

      PSK  Preshared Key (based on password and SSID)
      PMK  Pairwise Master Key (same as PSK)
      PTK  Pairwise Transient Key (based on PMK, AA, SPA, ANonce, SNonce)
      KCK  EAPOL Key Confirmation Key (PTK.bit0..127)    ;for handshake MIC's
      KEK  EAPOL Key Encryption Key   (PTK.bit128..255)  ;for handshake Key Data
      TK   Temporal Key (TKIP:PTK.bit256..511, CCMP:PTK.bit256..383)
      GMK  Group Master Key (don't care, used only internally by the access point)
      GTK  Group Transient Key (for multicast/broadcast) (based on GMK, AA, GNonce)

Summary of WPA/WPA2 Seeds

      password  ASCII password for the Wifi network
      SSID      ASCII name of access point
      AA        MAC address of access point (BSSID)
      SPA       MAC address of DSi console
      Anonce    Random number from access point (handshake message #1 and #3)
      Snonce    Random number from console      (handshake message #2)
      Gnonce    Random number internally used by access point (don't care)

Summary of WPA/WPA2 Checksums

      MIC       Message Integrity Code, checksum on EAPOL messages
      PMKID     PMK ID, checksum on PMK and AA, SPA (optional, don't care)

PRF(key,keylen, src,srclen, dst,dstlen, numrounds) ;Pseudo-Random Function

      for i=0 to (dstlen-1)/14
        call SHA1HMAC(src,srclen, key,keylen, tmpdst)
        tmpsum[0..13] = tmpdst[0..13]
        for j=1 to numrounds-1                        ;only if numrounds>1
          tmpsrc[0..13] = tmpdst[0..13], tmpsrclen=14
          call SHA1HMAC(tmpsrc,tmpsrclen, key,keylen, tmpdst)
          tmpsum[0..13] = tmpsum[0..13] XOR tmpdst[0..13]
        next j
        src[srclen-1] = src[srclen-1] + 01h           ;increase last byte of src
        len=min(14,(dstlen-i*14))
        dst[i*14+(0..(len-1))] = tmpsum[0..(len-1)]
      next i
      src[srclen-1] = src[srclen-1] - (dstlen+13)/14  ;undo increments, if desired

Note: This is using SHA1HMAC for both WPA and WPA2 (unlike the MIC, which is computed via MD5HMAC for WPA, and SHA1HMAC for WPA2).
PSK (Preshared Key) aka PMK (Pairwise Master Key)

      key = password,                      keylen = len(password)  ;ASCII string
      src = ssid + bytes(00h,00h,00h,01h), srclen = len(ssid)+4    ;ASCII string
      dst = PSK,                           dstlen = 32, numrounds=4096
      call PRF(key,keylen, src,srclen, dst,dstlen, numrounds)
      PMK=PSK

Computing the PSK/PMK requires 2x4096 SHA1HMAC calculations, which can be quite slow. The speed could be doubled by pre-computing the SHA1 states for "key XOR 36h's" and "key XOR 5Ch's". And, the PSK/PMK needs to be calculated only when changing the password/ssid (the DSi stores the PSK in Wifi-FLASH).
PTK (Pairwise Transient Key) and KCK/KEK/TK

      src[0..21]  = "Pairwise key expansion"
      src[22]     = byte(00h)
      src[23..28] = min(AA,SPA)         ;\MAC addresses (AA=BSSID, SPA=console)
      src[29..34] = max(AA,SPA)         ;/
      src[35..66] = min(ANonce,SNonce)  ;\nonces from 4-way handshake message 1+2
      src[67..98] = max(ANonce,SNonce)  ;/
      src[99]     = byte(00h)
      srclen = 22+1+6+6+32+32+1 = 100
      key=PSK, keylen=32, numrounds=1
      dst=PTK, dstlen=64  ;WPA needs dstlen=64 (WPA2 would also work with len=48)
      call PRF(key,keylen, src,srclen, dst,dstlen, numrounds)
      KCK    = PTK[00h..0Fh]   ;-for EAPOL handshake MIC checksums
      KEK    = PTK[10h..1Fh]   ;-for EAPOL handshake Key Data decryption
      TK.key = PTK[20h..2Fh]   ;-for data packets
      TX.tx  = PTK[30h..37h]   ;\needed for WPA/TKIP only (not WPA2/AES)
      TX.rx  = PTK[38h..3Fh]   ;/
      TK.keyindex = 0

GTK (Group Transient Key)

      GTK.key = GTK[00h..0Fh]  ;-for data packets
      GTX.tx  = GTK[10h..17h]  ;\needed for WPA/TKIP only (not WPA2/AES)
      GTX.rx  = GTK[18h..1Fh]  ;/
      GTK.keyindex = 1 or 2      ;WPA: from EAPOL Key Information bit4-5
      GTK.keyindex = 1 or 2      ;WPA2: from EAPOL Key Data KDE entry

MIC (Message Integrity Code)

      oldmic = EAPOL[51h..60h]
      EAPOL[51h..60h] = zerofill
      src=EAPOL, srclen=EAPOL[02h]*100h+EAPOL[03h]
      key=KCK, keylen=16
      if (EAPOL[06h] AND 07h)=1 then call MD5HMAC(src,srclen, key,keylen, dst)
      if (EAPOL[06h] AND 07h)=2 then call SHA1HMAC(src,srclen, key,keylen, dst)
      newmic = dst[0..0Fh]      ;16-byte MD5 result, or first 16byte of SHA1 result
      EAPOL[51h..60h] = newmic
      if newmic <> oldmic then error  ;when verifying MIC

PMKID (whatever ID, optional/useless, don't care)

      key=PMK, keylen=32
      src[0..7]   = "PMK Name"
      src[8..13]  = AA   ;aka MAC address of access point (BSSID)
      src[14..19] = SPA  ;aka MAC address of console
      srclen = 8+6+6 = 20
      call SHA1HMAC(src,srclen, key,keylen, dst)
      PMKID = dst[0..0Fh]   ;first 16byte of SHA1 result

Note: SHA1HMAC is used for WPA2. Unknown if WPA uses SHA1HMAC, or MD5HMAC, or if WPA does have PMKIDs at all.
Deriving GTK (done internally by access point, don't care)

      src[0..18]  = "Group key expansion"
      src[19]     = byte(00h)
      src[20..25] = AA                 ;MAC address (AA=BSSID)
      src[26..57] = GNonce             ;whaever random/timer/index
      src[58]     = byte(00h)
      srclen = 19+1+6+32+1 = 59
      key=GMK, keylen=32, numrounds=1  ;whatever random key
      dst=GTK, dstlen=32
      call PRF(key,keylen, src,srclen, dst,dstlen, numrounds)

This is the recommended way for creating the GTK, anyways, this is done internally by the access point, and everybody else doesn't need to worry about how the GTK was generated (ie. one just uses the GTK received in EAPOL messages).

DS Wifi WPA/WPA2 Encryption

Summary of Encryption/Decryption functions

      Encrypt/Decrypt WPA/WEP packets     --> RC4 (Rivest Cipher 4 aka ARC4)
      Encrypt/Decrypt WPA EAPOL key data  --> RC4 (Rivest Cipher 4 aka ARC4)
      Encrypt/Decrypt WPA2 EAPOL key data --> AES-Key-Wrap/Unwrap
      Encrypt/Decrypt WPA2 packets        --> AES-CCMP (AES-CTR-with-CBC-MAC)

RC4 (Rivest Cipher 4 aka ARC4) (WEP/WPA)
Both NDS-Wifi and DSi-Wifi have RC4 hardware support for encrypting and decrypting WEP/WPA packets, however, that's working only for full packets (not for the Key Data field in WPA EAPOL packets, so both NDS and DSi will require a RC4 software implementation for the EAPOL part).

      RC4(src,dst,len,preskip,key,keylen):
      for i=0 to FFh, sbox[i]=i, next i             ;-clear sbox
      j=0                                           ;\
      for i=0 to FFh                                ;
        j=(j+sbox[i]+key[i mod keylen]) and FFh     ; apply key
        swap(sbox[i],sbox[j]                        ;
      next i                                        ;/
      i=0, j=0
      for k=1 to preskip+len
        i=(i+1) and FFh, j=(j+sbox[i]) and FFh, swap(sbox[i],sbox[j])
        if preskip>0 then preskip=preskip-1
        else [dst]=[src] xor sbox[(sbox[i]+sbox[j]) and FFh], dst=dst+1, src=src+1
      next k
      parameters for WEP/WPA packets (done by hardware):
      key=iv(3)+password(5/13), keylen=3+5/13           ;WEP Key=WEP.IV+Password
      key=iv(3)+from PTK???,    keylen=3+???            ;WPA Key=WEP.IV+???
      src=data(n)+icv(4), srclen=n+4                    ;src, for WEP
      src=data(n)+mic(8)+icv(4), srclen=n+8+4           ;src, for WPA
      preskip=0
      parameters for WPA EAPOL key data (requires software implementation):
      key=EAPOL[31h..40h]+KEK[00h..0Fh], keylen=10h+10h ;Key = EAPOL Key IV + KEK
      src=EAPOL+63h, srclen=bigendian(EAPOL[61h])       ;src, for WPA
      preskip=100h

AES (Advanced Encryption Standard) (WPA2, DSi only)
NDS-Wifi doesn't have any AES hardware support at all, and a software implementation doesn't work because NDS-Wifi automatically applies WEP encryption (and adds/removes the WEP.IV field) when seeing the encryption flag in the frame header (and trying to disable the WEP hardware seems to cause encrypted packets not to be received at all).
DSi-Wifi has hardware support for AES-CCMP encrypted packets, however, AES-Key-Unwrap for Key Data in WPA2 EAPOL packets isn't supported by hardware, and does thus require a software implementation (the ARM7 AES hardware doesn't help because it supports AES-CTR and AES-CCM only).

      AES-Key-Wrap/Unwrap(src,dst,len,key,keylen,mode) (for WPA2 EAPOL Key Data)
      if (len and 7)<>0 then error  ;must be multiple of 8             ;-verify len
      aes_setkey(mode,key,keylen)                                      ;-init key
      if mode=ENCRYPT and [src+00h..07h]<>A6A6A6A6A6A6A6A6h then error ;-verify IV
      if mode=ENCRYPT then org=dst+8, count=1                   ;-for wrap
      if mode=DECRYPT then org=dst+len-8, count=((len-8)/8)*6   ;-for unwrap
      [dst+0..len-1] = [src+0..len-1]                  ;copy IV+DATA to dst
      [tmp+00h..07h] = [dst+00h..07h]                  ;read IV from dst+0
      for i=1 to 6
        ptr=org
        for j=1 to (len-8)/8
          [tmp+08h..0Fh] = [ptr+00h..07h]              ;read DATA from dst+index
          if mode=ENCRYPT then aes_crypt_block(ENCRYPT,tmp,tmp)  ;encrypt tmp
          [tmp+07h]=[tmp+07h] xor count                ;adjust byte[7]
          if mode=DECRYPT then aes_crypt_block(DECRYPT,tmp,tmp)  ;decrypt tmp
          [ptr+00h..07h] = [tmp+08h..0Fh]              ;writeback DATA to dst+index
          if mode=ENCRYPT then ptr=ptr+8, count=count+1
          if mode=DECRYPT then ptr=ptr-8, count=count-1
        next j
      next i
      [dst+00h..07h] = [tmp+00h..07h]                  ;writeback IV to dst+0
      if mode=DECRYPT and [dst+00h..07h]<>A6A6A6A6A6A6A6A6h then error ;-verify IV
      Parameters for Wrap/Unwrap:
      mode=ENCRYPT  ;<-- for Wrap (encrypt, used by access points)
      mode=DECRYPT  ;<-- for Unwrap (decrypt, used by clients)
      key=KEK, keylen=10h bytes (128bit)
      src=EAPOL+63h, srclen=bigendian(EAPOL[61h])

The "aes_setkey" and "aes_crypt_block" functions are same as the BIG-ENDIAN implementations described in DSi AES chapter:
DSi Advanced Encryption Standard (AES)
Access Points / Keys
Keys for different access points are stored in Wifi-FLASH. Access Point 1-3 can be configured as Open/WEP only, and Access Point 4-6 can be Open/WEP/WPA/WPA2 (these extra entries exist on DSi only, the standard NDS firmware doesn't have free memory for storing access point 4-6).
DS Firmware Wifi Internet Access Points
WPA/TKIP Encrypted Packets

      .. MAC Header         ;-Normal Header
      1  TSC1               ;\                   WEPSeed[1]=(TSC1 OR 20h) AND 7Fh
      1  WEPSeed[1]         ; WEP IV and Flags
      1  TSC0 (LSB)         ; (Flags: bit0-4=Rsvd, bit5=ExtIV, bit6-7=KeyID)
      1  Flags              ;/    (bit5: 0=No/WEP, 1=Yes/TKIP)
      1  TSC2               ;\
      1  TSC3               ; WPA Extended IV
      1  TSC4               ;
      1  TSC5 (MSB)         ;/
      .. Data               ;-Normal Data           ;\
      8  MIC                ;-WPA MIC "Michael"     ; encrypted area
      4  ICV                ;-WEP ICV               ;/
      4  FCS                ;-Normal FCS

WPA2/AES-CCMP Encrypted Packets

      .. MAC Header         ;-Normal Header
      1  PN0 (LSB)          ;\
      1  PN1                ; CCMP Header (IV and Flags)
      1  Rsvd               ; (Flags: bit0-4=Rsvd, bit5=ExtIV, bit6-7=KeyID)
      1  Flags              ;     (bit5: 0=No/WEP, 1=Yes/TKIP)
      1  PN2                ;
      1  PN3                ;
      1  PN4                ;
      1  PN5 (MSB)          ;/
      .. Data               ;-Normal Data           ;\encrypted area
      8  MIC                ;-CCMP MIC "AES MAC?"   ;/
      4  FCS                ;-Normal FCS

CCMP related: A2 (MPDU address 2), AAD, PN, Priority field of MPDU.
TKIP MIC

      6  DA
      6  SA
      1  Priority (0) (reserved for future)
      3  Zero (0) (also reserved for future)
      .. Data
      8  MIC (M0..M7) (aka L0..L3, R0..R3)

TKIP mixing

      TTAK     = Phase1 (TK, TA, TSC)
      WEP seed = Phase2 (TTAK, TK, TSC)

DS Wifi FFC ID

Wifi FCC ID
The wifi hardware has been registered by Mitsumi, Hon Hai, and Nintendo themselves:

      https://fccid.io/BKE - Nintendo
      https://fccid.io/EW4 - Mitsumi
      https://fccid.io/MCL - Hon Hai (Foxconn)

The above webpages include some unrelated stuff (like bluetooth), and some duplicate entries. The wifi/console related entries are:

      https://fccid.io/EW4-AGBWA      GBA        ;\GBA wireless adaptor
      https://fccid.io/EW4-OXYWA      GBA-Micro  ;/(not wifi/wlan compatible)
      https://fccid.io/BKENTR001      NDS (non-remove-able board)
      https://fccid.io/BKEUSG-001     NDS-Lite (old remove-able board, with MM3155)
      https://fccid.io/EW4DWMW006     NDS-Lite (new remove-able board, with MM3218)
      https://fccid.io/BKERVL036      Wii
      https://fccid.io/EW4DWMW004     Wii (mitsumi) (also W016, and maybe W014 ?)
      https://fccid.io/MCLJ27H010     Wii (foxconn) (also H003 ?)
      https://fccid.io/EW4DWMW015     DSi (old wifi board, mitsumi)
      https://fccid.io/EW4DWMW024     DSi (new wifi board, mitsumi)
      https://fccid.io/MCLJ27H020     DSi (new wifi board, foxconn)
      https://fccid.io/EW4DWMW028     3DS (mitsumi)
      https://fccid.io/MCLJ27H023     3DS (foxconn)
      https://fccid.io/MCLJ27H02301   2DS (foxconn)
      https://fccid.io/BKERED001      New3DS (on mainboard)

The pages include test reports, photos (including some prototypes), and most interestingly, the Mitsumi "Label location" pages are including pinout & signal names for most wifi boards.
DSi Wifi board pinout
https://fccid.io/EW4DWMW024/Label/Label-format-and-location-1137926.pdf
https://fccid.io/EW4DWMW015/Label/Label-Location-1031953.pdf

      1  MX_SD_CLK    2  GND
      3  GND          4  VDD_18
      5  SDIO_DATA0   6  VDD_18
      7  SDIO_DATA3   8  GND
      9  SDIO_DATA1   10 VDD_33
      11 SDIO_CMD     12 VDD_33
      13 SDIO_DATA2   14 GND
      15 JTAG_TDO     16 ATH_TX_H
      17 JTAG_TMS     18 SYS_RST_L
      19 GND          20 JTAG_TDI
      21 CLK32k       22 JTAG_TCK
      23 GND          24 JTAG_TRST_L
      25 NC(VDD28_TP) 26 SEL_ATH_L
      27 SPI_CS2      28 W_B
      29 BBP_SLEEP    30 SPI_CLK
      31 RF_SLEEP     32 SPI_DO   MISO
      33 RF_SCS       34 SPI_DI   MOSI
      35 BBP_SCS      36 CCA
      37 BB_RF_SDO    38 RXPE
      39 BB_RF_SDI    40 TRDATA
      41 BB_RF_SCLK   42 GND
      43 NC(VDD18_TP) 44 TRCLK
      45 GND          46 TRRDY
      47 MCLK         48 TXPE
      49 GND          50 RESET

DS-Lite Wifi board DWM-W006 pinout
https://fccid.io/EW4DWMW006/Label/ID-label-format-and-location-706511.pdf

      1  GND          16 +3.3V
      2  TXPE         17 GND
      3  RXPE         18 RF_SCS
      4  CCA          19 BBP_SLEEP
      5  TRRDY        20 BBP_SCS
      6  GND          21 RF_SLEEP
      7  TRCLK        22 RESET
      8  TRDATA       23 GND
      9  GND          24 SPI_CLK
      10 BB_RF_SDO    25 SPI_DI   MOSI
      11 BB_RF_SDI    26 SPI_DO   MISO
      12 BB_RF_SCLK   27 W_B
      13 GND          28 SPI_CS2
      14 MCLK         29 LD       ?
      15 GND          30 GND

Wii Wifi board
https://fccid.io/EW4DWMW004/Label/ID-Label-670426.pdf

      1  GND          12 VDD3.3
      2  SDIO_DATA_2  13 GND
      3  SDIO_DATA_1  14 GPIO_0
      4  GND          15 GND
      5  SDIO_CLK     16 SDIO_DATA_3
      6  GND          17 SDIO_DATA_0
      7  GPIO_1       18 GND
      8  GND          19 SDIO_CMD
      9  N.C.(VDD1.8) 20 GND
      10 N.C.(VDD1.8) 21 ANT_A (MAIN)
      11 VDD3.3       22 ANT_B (AUX)

3DS Wifi Board DWM-W028
https://fccid.io/EW4DWMW028/Label/ID-label-location-1272988.pdf

      1  MCLK         2  RF_CSRF
      3  GND          4  BB_CSBB
      5  RXPE         6  BB_RF_SDIN
      7  TXPE         8  BB_RF_SDOUT
      9  CCA          10 BB_RF_SCK
      11 TRDATA       12 GND
      13 TRCLK        14 BBP_SLEEP_L
      15 TRRDY        16 RF_SLEEP_L
      17 TRST_L       18 SEL_ATH_L
      19 GND          20 GND
      21 SDIO_DATA_0  22 JTAG_TDO
      23 SDIO_DATA_1  24 JTAG_TMS
      25 SDIO_DATA_2  26 JTAG_TDI
      27 SDIO_DATA_3  28 JTAG_TCK
      29 GND          30 SPI_CS2
      31 SDIO_CLK     32 W_B
      33 GND          34 SPI_CLK
      35 SDIO_CMD     36 SPI_DO   MISO
      37 UART_TXD     38 SPI_DI   MOSI
      39 UART_RXD     40 SYS_RST_L
      41 GND          42 ATH_TX_H
      43 CLK32k       44 RESET
      45 GND          46 GND
      47 VDD_18       48 VDD_33
      49 VDD_18       50 VDD_33

Functionally same as DSi, but not pin-compatible, and with two UART pins (instead of the NC pins).
GBA-Micro: device has two channels only: 2426.248MHz and 2456.576MHz.

DS Wifi Dslink/Wifiboot Protocol

Below is the transfer protocol for nocash "wifiboot" and devkitpro "dslink".
All UDP/TCP message are using Port 17491 (4453h).
Wifiboot UDP announce/reply and listen/connect/accept

      PC sends UPD announce message (repeatedly, as broadcast)  ;\
      console does TCP listen (if it isn't already listening)   ; UDP and
      console sends UDP reply message (repeatedly, to PC)       ; listen/accept
      PC does TCP connect (upon UDP reply)                      ;
      console does TCP accept (upon TCP connect)                ;/

The announce/reply strings in UDP messages depend on the file type:

      type      NDS/DSi    3DS.firm       3DS.3dsx
      announce  "dsboot"   "3dsfirmboot"  "3dsboot"
      reply     "bootds"   "bootfirm3ds"  "boot3ds"

After passing through the announce/reply phase, the actual data is transferred via TCP:
Wifiboot TCP blocks for NDS/DSi

      PC sends NDS header (170h bytes)                 ;SMALLER ;\
      PC sends Info Block (90h bytes)                      ;NEW ;
      console sends 32bit response word (4 bytes)               ;
      PC sends Icon/Title (optional, if response.bit17)    ;NEW ;
      PC sends DSi header (1000h bytes, if response.bit16)      ; TCP transfer
      PC sends ARM7 bootcode                                    ;
      PC sends ARM9 bootcode                                    ;
      PC sends ARM7i bootcode (optional, if response.bit16)     ;
      PC sends ARM9i bootcode (optional, if response.bit16)     ;
      PC sends commandline 32bit length (00000000h=none)        ;
      PC sends commandline string (if any)                      ;/

Wifiboot TCP blocks for 3DS.firm

      PC sends FIRM header (200h bytes)                         ;\
      PC sends Info Block (90h bytes)                           ;
      console sends 32bit response word (4 bytes)               ;
      PC sends Icon/Title (optional, if response.bit17)         ;
      PC sends Logo       (optional, if response.bit18)         ; TCP transfer
      PC sends Banner     (optional, if response.bit19)         ;
      PC sends FIRM section 0                                   ;
      PC sends FIRM section 1                                   ;
      PC sends FIRM section 2                                   ;
      PC sends FIRM section 3                                   ;
      PC sends commandline 32bit length (0=none)                ;
      PC sends commandline string (if any)                      ;/

Wifiboot TCP blocks for 3DS.3dsx
Not supported by wifiboot, but supported by devkitpro. The exact protocol is unknown, it seems to be similar to the above protocols, but with deflate compression (see "3dsboot" source code for details).
Response word (32bit)
This did originally contain 32bit error flags, and was later changed to contain request flags in bit16 and up (nonetheless, uploaders should keep treating any unexpected or unsupported request flags as errors).

      0-x   Error flags
      16    Request DSi header and ARM7i/ARM9i blocks (DSi)
      17    Request Icon/Title (NDS/DSi/3DS)
      18    Request Logo       (3DS)
      19    Request Banner     (3DS)
      20-31 Reserved (0)

The downloader should set request flags only if it wants to receive extra data, and only if the header or info block indicates that data to be available.
Info Block (90h bytes)
This did formerly contain NDS file bytes 170h..1FFh (ie. as if the cartheader were 200h bytes in size).

      00h 8   Overall ID "BootINFO" (if other: ignore all entries below)
      08h 24  Uploader name/version, zeropadded (eg. "nocash wifiboot v2.6")
      20h 1   Time Seconds    (BCD, 00h..59h)       ;\
      21h 1   Time Minutes    (BCD, 00h..59h)       ; current time (local timezone)
      22h 1   Time Hours      (BCD, 00h..23h)       ; (for updating lost RTC time)
      23h 1   Time DayOfWeek  (0..6, 0=Monday)      ; (or all zeroes = none)
      24h 1   Time Day        (BCD, 01h..31h)       ;
      25h 1   Time Month      (BCD, 01h..12h)       ;
      26h 1   Time Year       (BCD, 00h..99h)       ;
      27h 1   Time Century    (BCD, 00h..99h)       ;/
      28h 4   Icon/Title Size (0=None, 840h/940h/A40h/23C0h=NDS/DSi, 36C0h=3DS)
      2Ch 4   Logo Size       (0=None, Other=3DS only)
      30h 4   Banner Size     (0=None, Other=3DS only)
      34h 5Ch Reserved (0)

DS Xboo

The DS Xboo cable allows to upload NDS ROM-Images (max 3.9MBytes) to the console via parallel port connection. Should be the best, simpliest, easiest, and fastest way to test code on real hardware. And, at a relative decent price of 11 cents per diode it should be by far the least expensive way. You'll have to touch classic tools (screwdrivers, knifes, saws, tweezers, and solder) which will probably scare most of you to hell.
DS XBOO Connection Schematic

      Console Pin/Names             Parallel Port Pin/Names
      RFU.9    FMW.1 D    ---|>|--- DSUB.14    CNTR.14    AutoLF
      RFU.6    FMW.2 C    ---|>|--- DSUB.1     CNTR.1     Strobe
      RFU.10   FMW.3 /RES ---|>|--- DSUB.16    CNTR.31    Init
      RFU.7    FMW.4 /S   ---|>|--- DSUB.17    CNTR.36    Select
      RFU.5    FMW.5 /W   --. SL1A  -          -          N.C.
      RFU.28   FMW.6 VCC  __| SL1B  -          -          N.C.
      RFU.2,12 FMW.7 VSS  --------- DSUB.18-25 CNTR.19-30 Ground
      RFU.8    FMW.8 Q    --------- DSUB.11    CNTR.11    Busy
      P00 Joypad-A        ---|>|--- DSUB.2     CNTR.2     D0
      P01 Joypad-B        ---|>|--- DSUB.3     CNTR.3     D1
      P02 Joypad-Select   ---|>|--- DSUB.4     CNTR.4     D2
      P03 Joypad-Start    ---|>|--- DSUB.5     CNTR.5     D3
      P04 Joypad-Right    ---|>|--- DSUB.6     CNTR.6     D4
      P05 Joypad-Left     ---|>|--- DSUB.7     CNTR.7     D5
      P06 Joypad-Up       ---|>|--- DSUB.8     CNTR.8     D6
      P07 Joypad-Down     ---|>|--- DSUB.9     CNTR.9     D7
      RTC.1 INT aka SI    --------- DSUB.10    CNTR.10    /Ack

Parts List: 15 wires, four (DS) or twelve (DS-Lite) "BAT 85" diodes, 1 parallel port socket.
DS XBOO Connection Notes
The Firmware chip (FMW.Pins) hides underneath of the RFU shielding plate, so it'd be easier to connect the wires to the RFU.Pins (except DS-Lite: The RFU pins are terribly small (and have different pin-numbers), so either using FMW.Pins, or using mainboard vias (see below GIF) would be easier). The easiest way for the /W-to-VCC connection is to shortcut SL1 by putting some solder onto it.
The P00..P07 and INT signals are labeled on the switch-side of the mainboard, however, there should be more room for the cables when connecting them to via's at the bottom-side (except DS-Lite: P01 is found only at switch-side) image below may help to locate that pins,

      http://problemkaputt.de/nds-pins.gif (GIF-Image, 7.5KBytes)

At the parallel port side, DSUB.Pins or CNTR.Pins can be used for 25pin DSUB or 36pin Centronics sockets, the latter one allowing to use a standard printer cable.
The ring printed on the diodes is pointing towards parallel port side, the 4 diodes are required to prevent the parallel port to pull-up LOW levels on the NDS side, be sure to use BAT85 diodes, cheaper ones like 1N4148 are loosing too much voltage and won't gain stable LOW levels.
The power managment chip in the DS-Lite simply refuses to react to the Power-On button when P00..P07 are dragged high by the parallel port (even if it is in HighZ state), the 8 diodes in the data-lines are solving that problem (they are required on DS-Lite only, not on original DS).
DS XBOO Operation Notes
The main Upload function is found in no$gba Utility menu, together with further functions in Remote Access sub-menu.
Before uploading anything: download the original firmware, the file is saved as FIRMnnnn.BIN, whereas "nnnn" is equal to the last 16bit of the consoles 48bit MAC address, so Firmware-images from different consoles are having unique filenames. If you don't already have, also download the NDS BIOS, the BIOS contains encryption seed data required to encrypt/decrypt secure area; without having downloaded the BIOS, no$gba will be working only with unencrypted ROM-images. Next, select Patch Firmware to install the nocash firmware.
DS XBOO Troubleshooting
Be sure that the console is switched on, and that the XBOO cable is connected, and that you have selected the correct parallel port in no$gba setup (the "multiboot" options in Various Options screen), and, of course, try avoid to be fiddling with the joypad during uploads.
I've tested the cable on two computers, the overall upload/download stuff should work stable. The firmware access functions - which are required only for (un-)installation - worked only with one of the two computers; try using a different computer/parallel port in case of problems.
Nocash Firmware
The primary purpose is to receive uploaded NDS-images via parallel port connection, additionally it's containing bootmenu and setup screens similar to the original firmware. The user interface is having less cryptic symbols and should be alltogether faster and easier to use. Important Information about Whatever is supported (but it can be disabled). The setup contains a couple of additional options like automatic daylight saving time adjustment.
The bootmenu allows to boot normal NDS and GBA carts, it does additionally allow to boot NDS-images (or older PassMe-images) from flashcards in GBA slot. Furthermore, benefits of asm coding, the nocash firmware occupies less than 32KBytes, allowing to store (and boot) smaller NDS-images in the unused portion of the firmware memory (about 224KBytes), the zero-filled region between cart header and secure area, at 200h..3FFFh, is automatically excluded, so the image may be slightly bigger than the available free memory space.
Missing
Unlike the original firmware, the current version cannot yet boot via WLAN.

DSi Reference

Basic Hardware Features (mostly same as NDS)
NDS Reference
DSi Basic Differences to NDS
New Hardware Features
DSi I/O Map
DSi Control Registers (SCFG)
DSi XpertTeak (DSP)
DSi New Shared WRAM (for ARM7, ARM9, DSP)
DSi New DMA (NDMA)
DSi Microphone and SoundExt
DSi Advanced Encryption Standard (AES)
DSi Cartridge Header
DSi Touchscreen/Sound Controller
DSi I2C Bus
DSi Cameras
DSi SD/MMC Protocol and I/O Ports
DSi SD/MMC Filesystem
DSi Atheros Wifi SDIO Interface
DSi Atheros Wifi Internal Hardware
DSi GPIO Registers
DSi Console IDs
DSi Unknown Registers
DSi Notes
DSi Exploits
DSi Regions
General Info
ARM CPU Reference
BIOS Functions
External Connectors
Credits: http://www.dsibrew.org/wiki/Special:AllPages (now spammed)

DSi Basic Differences to NDS

Interrupts
There are several new interrupt sources in IE/IF registers, plus further ones in new IE2/IF2 registers.
DS Interrupts
Video
Essentially same as for NDS. Some details can be changed in SCFG_EXT. For the 2D Engine, DISPSTAT.Bit6 contains a new "LCD Initialization Ready" flag on both ARM7 and ARM9 side (the bit is checked by DSi System Menu) (the bit is supposedly used at power-up, maybe also for wake-up from certain sleep modes).
BIOS SWI Functions
Some SWI Functions are changed (bugged in some cases), new SHA1 and RSA functions are added, and the initial RAM contents are moved from 27FFxxxh to 2FFFxxxh (with some extra fields, eg. a copy of extended DSi cart header).
BIOS Functions
Revised Hardware Functions
Some hardware features have been slightly revised (for example, the division by 0 flag was fixed). The revised functions can be enabled/disabled via SCFG registers.
DSi Control Registers (SCFG)
NDS Slot / Cartridges
DSi carts are using an extended cart header (1000h bytes), with RSA signature (making it problematic to run unlicensed/homebrew code), the icon/title format has been also extended, and the cartridge protocol contains a new command (command 3Dh, for unlocking extra DSi regions on the cartridge, and for reading new DSi secure area blocks).
The NDS Slot's Reset signal can be controlled by software (required because otherwise one could use only command 3Ch or 3Dh, but not both). The Power supply pin can be also controlled by software (yet not 100% confirmed how?). Moreover, there's new cartridge inserted sensor. And, DSi prototypes did have two NDS slots; DSi retail consoles do have only one slot, but they do still contain prototype relicts internally (like extra registers and extra irq sources for second slot) (there appear to be also unused extra pins on the CPU, but they couldn't be used without desoldering the whole chip).
Enable Bits
One new DSi invention is that setting Enable Bits (eg. for NDMA or CAM registers) is write-protecting the corresponding registers (ie. those registers can be initialized only while the Enable Bits are off).
SPI Bus
The SPI bus works same as on NDS, except, one small change is added support for 8MHz SPI clock (in SPICNT.bit2).
SPI Touchscreen Controller
This chip is working entirely different in DSi mode. It's still accessed via SPI bus, but with some new PAGE/INDEX values.
DSi Touchscreen/Sound Controller
The touchscreen hardware can be switched to NDS compatibility mode.
SPI Power Managment Device
The Power Managment Device contains some changed register, and some new extra registers. Internally, it is actually split to two devices: The power managment chipselect signal connects to U3 and U4 chips. Ie. some SPI registers are processed by U3 (power down, and backlight enable), and others by R4 (audio out and microphone).
Further functions like LED control and backlight brightness are moved to the BPTWL chip, accessed via I2C bus instead of SPI bus - the power LED blink feature (which was used on Wifi access) seems to be no longer working, however, the Wifi LED seems to blink automatically on Wifi access; the changed backlight brightness mechanism shouldn't cause compatibility issuses since that feature is somewhat reserved for being controlled by the firmware.
SPI FLASH Memory (Wifi Calibration, User Settings, Firmware)
This memory does still exist, but it's only 128Kbytes in DSi (instead 256K), and most of it is empty (since the DSi Firmware is stored in the eMMC chip). Later DSi models do even the SPI FLASH capacity reduced to 4Kbytes.
RTC
Should be compatible with NDS. But seems to contain extra registers?
One of the RTC outputs does also seem to supply some (32kHz?) clock to some other mainboard components?
[XXX see Seiko S-35199A01 datasheet].
Wifi
Supports new WPA and WPA2 encryption and supports higher transfer rates (via a new SDIO wifi unit). For the old NDS-wifi mode, there are some new control registers:

      4004020h - SCFG_WL
      4004C04h - GPIO_WIFI
      BPTWL[30h] - Wifi LED related (also needed to enable Atheros Wifi SDIO)

SPI FLASH contains three new access point settings (for WPA/WPA2/proxy support):
DS Firmware Wifi Internet Access Points
The access point configuration can be done via Firmware (unlike as on NDS, where it needed to be done by the games).
GBA Slot
The GBA Slot has been removed. The memory regions and IRQ bits do still exist internally, but the DSi does basically behave as if there is no GBA cartridge inserted. Reading GBA ROM areas does return FFFFh halfwords instead of the usual open bus values though.
NDS Mode
In NDS mode, the DSi is basically working same as NDS: The new extra hardware is disabled, original NDS BIOS ROMs are mapped, and the hardware is simulating the old touchscreen controller.
Nonetheless, there are still a some small differences to real NDS consoles:
- Unlicensed NDS carts don't work (requires RSA, or whitelist for older games)
- GBA Slot is removed (more or less behaves as if no cart inserted)
- DSi ports 4004700h and 4004C0xh can be read (and written?) even in DS mode
- SPI Power Managment has some added/removed/changed registers
- SPI Touchscreen controller doesn't support pressure & temperature
- SPI FLASH exists, but it's smaller, and has extra access point info, etc.
- ARM7 BIOS has only first 20h bytes locked (instead first 1204h bytes)
- Power Button issues a Reset (goes to boot menu) (instead of plain power off)
- Power LED blink feature (for wifi) is replaced by a separate wifi LED
- RTC extra registers (if they do really exist) should exist in DS mode (?)
Unknown: does hot-swapping auto-power-off the nds-cart-slot in nds mode?

DSi I/O Map

DSi Memory Map
The overall memory map is same as on NDS. New/changed areas are:

      0000000h  64Kbyte ARM7 BIOS   (unlike NDS which had only 16KB)
      2000000h  16MByte Main RAM    (unlike NDS which had only 4MB)
      3000000h  800Kbyte Shared RAM (unlike NDS which had only 32KB)
      4004000h  New DSi I/O Ports
      8000000h  Fake GBA Slot (32MB+64KB) (FFh-filled; when mapped to current CPU)
      C000000h  Mirror of 16Mbyte Main RAM
      D000000h  Open Bus? in retail version, Extra 16Mbyte MainRAM in debug version
      FFFF000h  64Kbyte ARM9 BIOS   (unlike NDS which had only 4KB)

DSi I/O Maps
The overall DSi I/O Maps are same as on NDS,
DS I/O Maps
additional new/changed registers are:
ARM9 NDS Register that are changed in DSi mode

      4000004h 2   DISPSTAT (new Bit6, LCD Initialization Ready Flag)
      4000204h 2   EXMEMCNT (removed Bit0-7, ie. the GBA-slot related bits)
      4000210h 4   IE       (new interrupt sources, removed GBA-slot IRQ)
      4000214h 4   IF       (new interrupt sources, removed GBA-slot IRQ)
      40021A0h 4   Unknown, nonzero, probably same/silimar as on DSi7 side
      40021A4h 4   Unknown, zero, probably same/silimar as on DSi7 side
      40021A8h ..
      40021Bxh ..
      4102010h 4

ARM9 DSi System Control

      4004000h 2   SCFG_A9ROM DSi - NDS9 - ROM Status (R) [0000h]
      4004004h 2   SCFG_CLK   DSi - NDS9 - New Block Clock Control (R/W)
      4004006h 2   SCFG_RST   DSi - NDS9 - New Block Reset (R/W)
      4004008h 4   SCFG_EXT   DSi - NDS9 - Extended Features (R/W)
      4004010h 2   SCFG_MC    Memory Card Interface Status (16bit) (undocumented)

ARM9 DSi New Shared WRAM Bank Control

      4004040h 4   MBK1       WRAM-A Slots for Bank 0,1,2,3  ;\Global ARM7+ARM9
      4004044h 4   MBK2       WRAM-B Slots for Bank 0,1,2,3  ; Slot Mapping
      4004048h 4   MBK3       WRAM-B Slots for Bank 4,5,6,7  ; (R or R/W, depending
      400404Ch 4   MBK4       WRAM-C Slots for Bank 0,1,2,3  ; on MBK9 setting)
      4004050h 4   MBK5       WRAM-C Slots for Bank 4,5,6,7  ;/
      4004054h 4   MBK6       WRAM-A Address Range           ;\Local ARM9 Side
      4004058h 4   MBK7       WRAM-B Address Range           ; (R/W)
      400405Ch 4   MBK8       WRAM-C Address Range           ;/
      4004060h 4   MBK9       WRAM-A/B/C Slot Write Protect (R)

ARM9 DSi New DMA (NDMA)

      4004100h 4   NDMAGCNT   NewDMA Global Control                     ;-Control
      4004104h 4   NDMA0SAD   NewDMA0 Source Address                    ;\
      4004108h 4   NDMA0DAD   NewDMA0 Destination Address               ;
      400410Ch 4   NDMA0TCNT  NewDMA0 Total Length for Repeats          ; NewDMA0
      4004110h 4   NDMA0WCNT  NewDMA0 Logical Block Size                ;
      4004114h 4   NDMA0BCNT  NewDMA0 Block Transfer Timing/Interval    ;
      4004118h 4   NDMA0FDATA NewDMA0 Fill Data                         ;
      400411Ch 4   NDMA0CNT   NewDMA0 Control                           ;/
      4004120h 4   NDMA1SAD                                             ;\
      4004124h 4   NDMA1DAD                                             ;
      4004128h 4   NDMA1TCNT                                            ; NewDMA1
      400412Ch 4   NDMA1WCNT                                            ;
      4004130h 4   NDMA1BCNT                                            ;
      4004134h 4   NDMA1FDATA                                           ;
      4004138h 4   NDMA1CNT                                             ;/
      400413Ch 4   NDMA2SAD                                             ;\
      4004140h 4   NDMA2DAD                                             ;
      4004144h 4   NDMA2TCNT                                            ; NewDMA2
      4004148h 4   NDMA2WCNT                                            ;
      400414Ch 4   NDMA2BCNT                                            ;
      4004150h 4   NDMA2FDATA                                           ;
      4004154h 4   NDMA2CNT                                             ;/
      4004158h 4   NDMA3SAD                                             ;\
      400415Ch 4   NDMA3DAD                                             ;
      4004160h 4   NDMA3TCNT                                            ; NewDMA3
      4004164h 4   NDMA3WCNT                                            ;
      4004168h 4   NDMA3BCNT                                            ;
      400416Ch 4   NDMA3FDATA                                           ;
      4004170h 4   NDMA3CNT                                             ;/

ARM9 DSi Camera Module

      4004200h 2   CAM_MCNT   Camera Module Control (16bit)
      4004202h 2   CAM_CNT    Camera Control (16bit)
      4004204h 4   CAM_DAT    Camera Data (32bit)
      4004210h 4   CAM_SOFS   Camera Trimming Starting Position Setting (32bit)
      4004214h 4   CAM_EOFS   Camera Trimming Ending Position Setting (32bit)

ARM9 DSi DSP - XpertTeak processor

      4004300h 2   DSP_PDATA  DSP Transfer Data
      4004304h 2   DSP_PADR   DSP Transfer Address
      4004308h 2   DSP_PCFG   DSP Configuration
      400430Ch 2   DSP_PSTS   DSP Status
      4004310h 2   DSP_PSEM   DSP ARM9-to-DSP Semaphore          (R/W)
      4004314h 2   DSP_PMASK  DSP DSP-to-ARM9 Semaphore Mask     (R/W)
      4004318h 2   DSP_PCLEAR DSP DSP-to-ARM9 Semaphore Clear    (W)
      400431Ch 2   DSP_SEM    DSP DSP-to-ARM9 Semaphore Data     (R)
      4004320h 2   DSP_CMD0   DSP ARM9-to-DSP Command Register 0 (R/W)
      4004324h 2   DSP_REP0   DSP DSP-to-ARM9 Reply Register 0   (R)
      4004328h 2   DSP_CMD1   DSP ARM9-to-DSP Command Register 1 (R/W)
      400432Ch 2   DSP_REP1   DSP DSP-to-ARM9 Reply Register 1   (R)
      4004330h 2   DSP_CMD2   DSP ARM9-to-DSP Command Register 2 (R/W)
      4004334h 2   DSP_REP2   DSP DSP-to-ARM9 Reply Register 2   (R)
      4004340h C0h DSP_mirror Mirrors of above 40h-byte DSP register area

ARM7 DSi

      4000004h 2   DISPSTAT (new Bit6, LCD Initialization Ready Flag) (as DSi9?)
      40001C0h 2   SPICNT   (new Bit2, for 8MHz transfer clock)
      4000204h 2   EXMEMCNT (removed Bit0-7: GBA-slot related bits)   (as DSi9?)
      4000210h 4   IE       (new interrupt sources, removed GBA-slot IRQ)
      4000214h 4   IF       (new interrupt sources, removed GBA-slot IRQ)
      4000218h     IE2      (new register with more new interrupt sources)
      400021Ch     IF2      (new register with more new interrupt sources)

ARM7 DSi Maybe 2nd ROM slot (DSi prototypes did have 2 cartridge slots)

      40021A0h 4   Unknown, nonzero, probably related to below 40021A4h
      40021A4h 4   Unknown, related to 40001A4h (Gamecard Bus ROMCTRL)
      40021A8h ..
      40021Bxh ..
      4102010h 4

ARM7 DSi System Control

      4004000h 1   SCFG_A9ROM used by BIOS and SystemFlaw   (bit0,1)
      4004001h 1   SCFG_A7ROM used by BIOS and SystemFlaw   (bit0,1,2)
      4004004h 2   SCFG_CLK7  used by SystemFlaw
      4004006h 2   SCFG_JTAG  Debugger Control
      4004008h 4   SCFG_EXT7  used by SystemFlaw
      4004010h 2   SCFG_MC    Memory Card Interface Control (R/W)  ;\
      4004012h 2   SCFG_CARD_INSERT_DELAY (usually 1988h = 100ms)  ; Game Cartridge
      4004014h 2   SCFG_CARD_PWROFF_DELAY (usually 264Ch = 150ms)  ;/
      4004020h 2   SCFG_WL    Wireless Disable    ;bit0 = wifi?
      4004024h 2   SCFG_OP    Debugger Type (R)   ;bit0-1 = (0=retail, ?=debug)

ARM7 DSi New Shared WRAM Bank Control

      4004040h 4   MBK1       WRAM-A Slots for Bank 0,1,2,3  ;\
      4004044h 4   MBK2       WRAM-B Slots for Bank 0,1,2,3  ; Global ARM7+ARM9
      4004048h 4   MBK3       WRAM-B Slots for Bank 4,5,6,7  ; Slot Mapping (R)
      400404Ch 4   MBK4       WRAM-C Slots for Bank 0,1,2,3  ; (set on ARM9 side)
      4004050h 4   MBK5       WRAM-C Slots for Bank 4,5,6,7  ;/
      4004054h 4   MBK6       WRAM-A Address Range           ;\Local ARM7 Side
      4004058h 4   MBK7       WRAM-B Address Range           ; (R/W)
      400405Ch 4   MBK8       WRAM-C Address Range           ;/
      4004060h 4   MBK9       WRAM-A/B/C Slot Write Protect (R/W)

ARM7 DSi New DMA (NDMA)

      4004100h 74h NewDMA (new DMA, as on ARM9i, see there)

ARM7 DSi AES Encryption Unit

      4004400h 4   AES_CNT    (R/W)
      4004404h 4   AES_BLKCNT (W)
      4004408h 4   AES_WRFIFO (W)
      400440Ch 4   AES_RDFIFO (R)
      4004420h 16  AES_IV     (W)
      4004430h 16  AES_MAC    (W)
      4004440h 48  AES_KEY0   (W) ;used for modcrypt
      4004470h 48  AES_KEY1   (W) ;used for ?
      40044A0h 48  AES_KEY2   (W) ;used for JPEG signatures
      40044D0h 48  AES_KEY3   (W) ;used for eMMC sectors

ARM7 DSi I2C Bus

      4004500h 1   I2C_DATA
      4004501h 1   I2C_CNT

ARM7 DSi Microphone

      4004600h 2   MIC_CNT    Microphone Control
      4004604h 4   MIC_DATA   Microphone FIFO

ARM7 DSi SNDEX

      4004700h 2   SNDEXCNT             <-- can be read even in DS mode!

ARM7 DSi SD/MMC Registers for Memory Card access (SD Card and onboard eMMC)

      4004800h 2   SD_CMD              Command and Response/Data Type
      4004802h 2   SD_CARD_PORT_SELECT   (SD/MMC:020Fh, SDIO:010Fh)
      4004804h 4   SD_CMD_PARAM0-1     Argument (32bit, 2 halfwords)
      4004808h 2   SD_STOP_INTERNAL_ACTION
      400480Ah 2   SD_DATA16_BLK_COUNT        "Transfer Block Count"
      400480Ch 16  SD_RESPONSE0-7 (128bit, 8 halfwords)
      400481Ch 4   SD_IRQ_STATUS0-1  ;IRQ Status  (0=ack, 1=req)
      4004820h 4   SD_IRQ_MASK0-1    ;IRQ Disable (0=enable, 1=disable)
      4004824h 2   SD_CARD_CLK_CTL Card Clock Control
      4004826h 2   SD_DATA16_BLK_LEN  Memory Card Transfer Data Length
      4004828h 2   SD_CARD_OPTION Memory Card Option Setup (can be C0FFh)
      400482Ah 2   Fixed always zero?
      400482Ch 4   SD_ERROR_DETAIL_STATUS0-1   Error Detail Status
      4004830h 2   SD_DATA16_FIFO        Data Port  (SD_FIFO?)
      4004832h 2   Fixed always zero?       ;(TC6371AF:BUF1 Data MSBs?)
      4004834h 2   SD_CARD_IRQ_CTL          ;(SD_TRANSACTION_CTL)
      4004836h 2   SD_CARD_IRQ_STAT         ;(SD_CARD_INTERRUPT_CONTROL)
      4004838h 2   SD_CARD_IRQ_MASK         ;(SDCTL_CLK_AND_WAIT_CTL)
      400483Ah 2   Fixed always zero?       ;(SDCTL_SDIO_HOST_INFORMATION)
      400483Ch 2   Fixed always zero?       ;(SDCTL_ERROR_CONTROL)
      400483Eh 2   Fixed always zero?       ;(TC6387XB: LED_CONTROL)
      4004840h 2   Fixed always 003Fh?
      4004842h 2   Fixed always 002Ah?
      4004844h 6Eh Fixed always zerofilled?
      40048B2h 2   Fixed always FFFFh?
      40048B4h 6   Fixed always zerofilled?
      40048BAh 2   Fixed always 0200h?
      40048BCh 1Ch Fixed always zerofilled?
      40048D8h 2   SD_DATA_CTL
      40048DAh 6   Fixed always zerofilled?
      40048E0h 2   SD_SOFT_RESET  Software Reset (bit0=SRST=0=reset)
      40048E2h 2   Fixed always 0009h?      ;(RESERVED2/9, TC6371AF:CORE_REV)
      40048E4h 2   Fixed always zero?
      40048E6h 2   Fixed always zero?       ;(RESERVED3, TC6371AF:BUF_ADR)
      40048E8h 2   Fixed always zero?       ;(TC6371AF:Resp_Header)
      40048EAh 6   Fixed always zerofilled?
      40048F0h 2   Fixed always zero?       ;(RESERVED10)
      40048F2h 2   ? Can be 0003h
      40048F4h 2   ? Can be 0770h
      40048F6h 2   SD_WRPROTECT_2 (R)  ;Write protect for eMMC   (RESERVED4)
      40048F8h 4   SD_EXT_IRQ_STAT0-1  ;Insert/eject for eMMC    (RESERVED5-6)
      40048FCh 4   SD_EXT_IRQ_MASK0-1       ;(TC6371AF:Revision) (RESERVED7-8)
      4004900h 2   SD_DATA32_IRQ
      4004902h 2   Fixed always zero?
      4004904h 2   SD_DATA32_BLK_LEN
      4004906h 2   Fixed always zero?
      4004908h 2   SD_DATA32_BLK_COUNT
      400490Ah 2   Fixed always zero?
      400490Ch 4   SD_DATA32_FIFO
      4004910h F0h Fixed always zerofilled?

ARM7 DSi SD/MMC Registers for SDIO access (for Atheros Wifi)

      4004A00h 512 SDIO_xxx (same as SD_xxx at 4004800h..40049FFh, see there)
      4004A02h 2   SDIO_CARD_PORT_SELECT (slightly different than 4004802h)

ARM7 DSi General Purpose I/O (GPIO) (headphone connect, power button)

      4004C00h 1   GPIO Data In                (R)  (even in DS mode)
      4004C00h 1   GPIO Data Out               (W)
      4004C01h 1   GPIO Data Direction         (R/W)
      4004C02h 1   GPIO Interrupt Edge Select  (R/W)
      4004C03h 1   GPIO Interrupt Enable       (R/W)
      4004C04h 2   GPIO_WIFI                   (R/W)

ARM7 DSi CPU/Console ID (used as eMMC key)

      4004D00h 8   CPU/Console ID Code (64bit) (R)
      4004D08h 2   CPU/Console ID Flag (1bit)  (R)

ARM7 DSi Junk?

      8030200h 2   GBA area, accessed alongsides with SDIO port [4004A30h] (bug?)

Main Memory Control

      2FFFFFEh 2   Main Memory Control (for 16MByte RAM chip)
      DFFFFFEh 2   Main Memory Control (extra 16MByte RAM chip in debug version)

DSi Control Registers (SCFG)

4004000h - DSi9 - SCFG_A9ROM - ROM Status (R) [0000h]

      0     ARM9 BIOS Upper 32K half of DSi BIOS (0=Enabled, 1=Disabled)
      1     ARM9 BIOS for NDS Mode               (0=DSi BIOS, 1=NDS BIOS)
      2-15  Unused (0)
      16-31 Unspecified (0)

Possible values are:

      00h  DSi ROM mapped at FFFFxxxxh, full 64K enabled (during bootstage 1 only)
      01h  DSi ROM mapped at FFFFxxxxh, lower 32K only
      03h  NDS ROM mapped at FFFFxxxxh (internal setting)
      00h  NDS ROM mapped at FFFFxxxxh (visible setting due to SCFG_EXT.bit31=0)

Checking for A9ROM=01h is common for detecting if the console is a "DSi console running in DSi mode".
4004000h - DSi7 - SCFG_ROM - ROM Control (R/W, Set-Once)

      0     ARM9 BIOS Upper 32K half of DSi BIOS (0=Enabled, 1=Disabled)
      1     ARM9 BIOS for NDS Mode               (0=DSi BIOS, 1=NDS BIOS)
      2-7   Unused (0)
      8     ARM7 BIOS Upper 32K half of DSi BIOS (0=Enabled, 1=Disabled)
      9     ARM7 BIOS for NDS Mode               (0=DSi BIOS, 1=NDS BIOS)
      10    Access to Console ID registers       (0=Enabled, 1=Disabled) (4004Dxxh)
      11-31 Unused (0)

Bits in this register can be set once (cannot be changed back from 1 to 0).
Don't change bit1 while executing IRQs or SWI functions on ARM9 side.
The System Menu sets bit10 shortly before starting any Cartridges or DSiware files (except System Base Tools) (for NDS mode, after having set bit10, it's also setting bit1 and bit9).
4004004h - DSi9 - SCFG_CLK - New Block Clock Control (R/W) [0084h]

      0     ARM9 CPU Clock         (0=NITRO/67.03MHz, 1=TWL/134.06MHz) (TCM/Cache)
      1     Teak DSP Block Clock   (0=Stop, 1=Run)
      2     Camera Interface Clock (0=Stop, 1=Run)
      3-6   Unused (0)
      7     New Shared RAM Clock   (0=Stop, 1=Run)               (set via ARM7) (R)
      8     Camera External Clock  (0=Disable, 1=Enable) ("outputs at 16.76MHz")
      9-15  Unused (0)
      16-31 See below (Port 4004006h, SCFG_RST)

Change ARM9 clock only from code within ITCM (and wait at least 8 cycles before accessing any non-ITCM memory).
Disable the corresponding modules before stopping their clocks.
4004004h - DSi7 - SCFG_CLK7 (R/W)

      0     SD/MMC Clock      (0=Stop, 1=Run) (should be same as SCFG_EXT7.bit18)
      1     Unknown/used      (0=Stop, 1=Run) (backlight goes off when cleared?)
      2     Unknown/used      (0=Stop, 1=Run) (unknown effect?)
      3-6   Unused (0)
      7     New Shared RAM Clock   (0=Stop, 1=Run)
      8     Touchscreen Clock (0=Stop, 1=Run) (needed for touchscr input)
      9-15  Unused (0)
      16-31 See below (Port 4004006h, SCFG_JTAG)

4004006h - DSi9 - SCFG_RST - New Block Reset (R/W) [0000h]

      0     DSP Block Reset (0=Apply Reset, 1=Release Reset)
      1-15  Unused (0)

4004006h - DSi7 - SCFG_JTAG - Debugger Control (R/W? or Write-ONCE-only?)

      0     ARM7SEL (set when debugger can do ARM7 debugging)
      1     CPU JTAG Enable
      2-7   Unused (0)
      8     DSP JTAG Enable
      9-15  Unused (0)

Initialized as so: if SCFG_OP=2 then SCFG_JTAG=0102h, elseif SCFG_OP=1 then SCFG_JTAG=0103h, entrypoint=0, endif.
4004008h - DSi9 - SCFG_EXT - Extended Features (R/W) [8307F100h]

      0     Revised ARM9 DMA Circuit       (0=NITRO, 1=Revised)
      1     Revised Geometry Circuit       (0=NITRO, 1=Revised)
      2     Revised Renderer Circuit       (0=NITRO, 1=Revised)
      3     Revised 2D Engine Circuit      (0=NITRO, 1=Revised)
      4     Revised Divider Circuit        (0=NITRO, 1=Revised)
      5-6   Unused (0)
      7     Revised Card Interface Circuit (0=NITRO, 1=Revised)
      8     Extended ARM9 Interrupts       (0=NITRO, 1=Extended)
      9-11  Unused (0)
      12    Extended LCD Circuit           (0=NITRO, 1=Extended)
      13    Extended VRAM Access           (0=NITRO, 1=Extended)
      14-15 Main Memory RAM Limit (0..1=4MB/DS, 2=16MB/DSi, 3=32MB/DSiDebugger)
      16    Access to New DMA Controller   (0=Disable, 1=Enable) (40041xxh)
      17    Access to Camera Interface     (0=Disable, 1=Enable) (40042xxh)
      18    Access to Teak DSP Block       (0=Disable, 1=Enable) (40043xxh)
      19-23 Unused (0)
      24    Access to 2nd NDS Cart Slot   (0=Disable, 1=Enable)  (set via ARM7) (R)
      25    Access to New Shared WRAM     (0=Disable, 1=Enable)  (set via ARM7) (R)
      26-30 Unused (0)
      31    Access to SCFG/MBK registers  (0=Disable, 1=Enable) (4004000h-4004063h)

Bit24-25 are READ-ONLY (showing state set via ARM7 side). Note: Official specs for Bit24-25 are nonsense.
Default settings seem to be:

      8307F100h for DSi firmware, DSi cartridges and DSiware
      03000000h for NDS cartridges (and DSiware in NDS mode, eg. Pictochat)

Main RAM mapping depending on bit14-15:

      Mode         2000000h-2FFFFFFh   C000000h-CFFFFFFh   D000000h-DFFFFFFh
      4MB (0 or 1) 1st 4MB (+mirrors)  Zerofilled          Zerofilled
      16MB (2)     1st 16MB            1st 16MB (mirror)   1st 16MB (mirror)
      32MB (3)     1st 16MB            1st 16MB (mirror)   Open bus (or 2nd 16MB)

DSi9 SCFG_EXT.bit14-15 affect the Main RAM mapping on <both> ARM9 and ARM7 side (that, at least AFTER games have been booted, however, there's a special case DURING boot process: For NDS games, the firmware switches to 4MB mode on ARM9 side, whilst ARM7 is still relocating memory from the 16MB area at the same time - unknown how that is working exactly, maybe ARM7 isn't affected by ARM9 SCFG_EXT setting until ARM7 has configured/disabled its own SCFG_EXT register).
The 32MB mode requires an extra RAM chip (present in DSi debug version only; DSi retail consoles return 16bit open bus values instead of extra memory). RAM Size/Openbus detection is conventionally done by trying to read/write a BYTE at [0DFFFFFAh].
4004008h - DSi7 - SCFG_EXT7 - Extended Features (R/W)

      0     Revised ARM7 DMA Circuit       (0=NITRO, 1=Revised)
      1     Revised Sound DMA              (0=NITRO, 1=Revised)
      2     Revised Sound                  (0=NITRO, 1=Revised)
      3-6   Unused (0)
      7     Revised Card Interface Circuit (0=NITRO, 1=Revised) (set via ARM9) (R)
      8     Extended ARM7 Interrupts      (0=NITRO, 1=Extended) (4000218h)
      9     Extended SPI Clock (8MHz)     (0=NITRO, 1=Extended) (40001C0h)
      10    Extended Sound DMA        ?   (0=NITRO, 1=Extended) (?)
      11    Undocumented/Unknown      ??  (0=NITRO, 1=Extended) (?)
      12    Extended LCD Circuit          (0=NITRO, 1=Extended) (set via ARM9) (R)
      13    Extended VRAM Access          (0=NITRO, 1=Extended) (set via ARM9) (R)
      14-15 Main Memory RAM Limit    (0..1=4MB, 2=16MB, 3=32MB) (set via ARM9) (R)
      16    Access to New DMA Controller  (0=Disable, 1=Enable) (40041xxh)
      17    Access to AES Unit            (0=Disable, 1=Enable) (40044xxh)
      18    Access to SD/MMC registers    (0=Disable, 1=Enable) (40048xxh-40049xxh)
      19    Access to SDIO Wifi registers (0=Disable, 1=Enable) (4004Axxh-4004Bxxh)
      20    Access to Microphone regs     (0=Disable, 1=Enable) (40046xxh)
      21    Access to SNDEXCNT register   (0=Disable, 1=Enable) (40047xxh)
      22    Access to I2C registers       (0=Disable, 1=Enable) (40045xxh)
      23    Access to GPIO registers      (0=Disable, 1=Enable) (4004Cxxh)
      24    Access to 2nd NDS Cart Slot   (0=Disable, 1=Enable) (40021xxh)
      25    Access to New Shared WRAM     (0=Disable, 1=Enable) (3xxxxxxh)
      26-27 Unused (0)
      28    Undocumented/Unknown          (0=???, 1=Normal)     (?)
      29-30 Unused (0)
      31    Access to SCFG/MBK registers  (0=Disable, 1=Enable) (4004000h-4004063h)

Bit7,12-15 are READ-ONLY (showing state set via ARM9 side).
Default settings seem to be:

      93FFFB06h for DSi Firmware (Bootcode and SysMenu/Launcher)
      13FFFB06h for DSiware (eg. SysSettings, Flipnote, PaperPlane)
      13FBFB06h for DSi Cartridges (eg. System Flaw)            (bit18=0=sdmmc off)
      12A03000h for NDS cartridges (and DSiware in NDS mode, eg. Pictochat)

Bits 0,1,2,10,18,31 are taken from carthdr[1B8h].
4004010h - DSi9 - SCFG_MC - NDS Slot Memory Card Interface Status (R)
4004010h - DSi7 - SCFG_MC - NDS Slot Memory Card Interface Control (R/W)

      0     1st NDS Slot Game Cartridge (0=Inserted, 1=Ejected)               (R)
      1     1st NDS Slot Unknown/Unused (0)
      2-3   1st NDS Slot Power State (0=Off, 1=On+Reset, 2=On, 3=RequestOff)  (R/W)
      4     2nd NDS Slot Game Cartridge (always 1=Ejected) ;\DSi              (R)
      5     2nd NDS Slot Unknown/Unused (0)                ; prototype
      6-7   2nd NDS Slot Power State    (always 0=Off)     ;/relict           (R/W)
      8-14  Unknown/Undocumented (0)
      15    Swap NDS Slots (0=Normal, 1=Swap)                                 (R/W)
      16-31 ARM7: See Port 4004012h, ARM9: Unspecified (0)

Note: Additionally, the NDS slot Reset pin can be toggled (via ROMCTRL.Bit29; that bit is writeable on ARM7 side on DSi; which wasn't supported on NDS).
Power state values:

      0=Power is Off
      1=Power On and force Reset (shall be MANUALLY changed to state=2)
      2=Power On
      3=Request Power Off (will be AUTOMATICALLY changed to state=0)

cart_power_on: (official/insane 1+10+27+120ms, but also works with 1+1+0+1ms)

      wait until state<>3                   ;wait if pwr off busy
      exit if state<>0 AND no_reset_wanted  ;exit if already on & no reset wanted
      wait 1ms, then set state=1            ;pwr on & force reset
      wait 10ms, then set state=2           ;pwr on normal state   ;better: 1ms
      wait 27ms, then set ROMCTRL=20000000h ;release reset pin     ;better: 0ms
      wait 120ms (or 270ms on 3DS)          ;more insane delay?    ;better: 1ms

cart_power_off: (official 150ms, when using default [4004014h]=264Ch)

      wait until state<>3                   ;wait if pwr off busy
      exit if state<>2                      ;exit if already off
      set state=3                           ;request pwr off
      exit unless you want to know when below pointless delay has ellapsed
      wait until state=0    ;default=150ms  ;wait until pwr off    ;better: skip

Power Off is also done automatically by hardware when ejecting the cartridge.
The Power On sequence does reset ROMCTRL.bit29=0 (reset signal).
Bit15 swaps ports 40001A0h-40001BFh and 4100010h with 40021A0h-40021BFh? and 4102010h?, the primary purpose is mapping the 2nd Slot to the 4xx0xxxh registers (for running carts in 2nd slot in NDS mode; which of course doesn't work because the 2nd slot connector isn't installed), theoretically it would also allow to access the 1st slot via 4xx2xxxh registers (however, that doesn't seem to be fully implemented, cart reading does merely reply FFh's (cart inserted) or 00h's (no cart)). 4102010h can be read by manually polling DRQ in 40021A4h.bit23, and probably by NDMA (but not by old DMA which has no known DRQ mode for 2nd slot).
4004012h - DSi7 - SCFG_CARD_INSERT_DELAY (usually 1988h = 100ms) (R/W)
4004014h - DSi7 - SCFG_CARD_PWROFF_DELAY (usually 264Ch = 150ms) (R/W)

      0-15  Delay in 400h cycle units (at 67.027964MHz)  ;max FFFFh=ca. 1 second

Usually set to 1988h/264Ch by firmware. Power up default is FFFFh/FFFFh, with that setting it takes about 1 second to sense inserted carts (after power-up, or after cart-insert).
Insert delay defines the time until SCFG_MC.bit0 reacts upon cart insert, and until cart access works (cart eject works instantly regardless of the delay setting). The 3DS bootrom uses 051Dh=20ms, which may be good to avoid switch bounce. The DSi/3DS firmwares use 1988h=100ms, which might be reasonable if the switch triggers too early.
Power Off delay defines how fast SCGF_MC.bit2-3 are changing from state=3 (request power off) to state=0 (power off). The 3DS bootrom uses 051Dh=20ms, the DSi/3DS firmwares use 264Ch=150ms, which is both kinda pointless. If the VCC pin is kept powered during that time (?) then the delay might help to finish FLASH writes (which would make sense only if there was data written to cartridge).
4004020h - DSi7 - SCFG_WL - Wireless Disable (R/W)

      0     OFFB, related to Wifi Enable flag from TWLCFGn.dat files?
      1-15  Unknown/unused (0)

Unknown what that does. SDIO Wifi seems to work regardless of that bit.
4004024h - DSi7 - SCFG_OP - Debugger Type (R)

      0-1   Debug Hardware Type (0=Retail, other=debug variants)
      2-3   Unknown/unused (0)
      4     Unknown (maybe used, since it isn't masked & copied to RAM)
      5-15  Unknown/unused (0)

Changing this register would theoretically allow to install the debug firmware on retail consoles, however, it's unknown where bit0-1 come from (possibly from some external FLASH memory, internal PROM in the TWL CPU, solder pads underneath of the TWL CPU, or even from a physically different TWL CPU chip version).

DSi XpertTeak (DSP)

The DSi includes an XpertTeak Digital Signal Processor (DSP); which is consisting of a TeakLite II processor, plus some "expert" features (like DMA support). The thing appears to be intended for audio/video decoding, but it's left unused by most DSi games. However, it's used by the "Nintendo DSi Sound" and "Nintendo Zone" system utilities, and by the "Cooking Coach" cartridge.
DSi Teak Misc
XpertTeak I/O Registers (on ARM side)
DSi Teak I/O Ports (on ARM9 Side)
XpertTeak I/O Registers (on Teak side)
DSi Teak MMIO - Register Summary
DSi Teak MMIO[8000h] - Misc Registers (JAM/GLUE)
DSi Teak MMIO[8020h] - Timers (TMR)
DSi Teak MMIO[8050h] - Serial Port (SIO)
DSi Teak MMIO[8060h] - Debug (OCEM, On-chip Emulation Module)
DSi Teak MMIO[8080h] - PLL and Power (PMU, Power Management Unit)
DSi Teak MMIO[80C0h] - Host Port Interface (APBP aka HPI)
DSi Teak MMIO[80E0h] - AHBM - Advanced High Performance Bus Master
DSi Teak MMIO[8100h] - Memory Interface Unit (MIU)
DSi Teak MMIO[8140h] - Code Replacement Unit (CRU)
DSi Teak MMIO[8180h] - Direct Memory Access (DMA)
DSi Teak MMIO[8200h] - Interrupt Control Unit (ICU)
DSi Teak MMIO[8280h] - Audio (Buffered Time Division Multiplexing Port)
TeakLite II Processor
DSi Teak CPU Registers
DSi Teak CPU Control/Status Registers
DSi Teak CPU Address Config/Step/Modulo
DSi TeakLite II Instruction Set Encoding
DSi TeakLite II Operand Encoding

DSi Teak Misc

Teak Instruction Set References
There aren't any official references for the Teak instruction set. However, there's one document that has leaked into internet (plus some docs for older Oak instruction set):

      TeakLite Architecture Specification Revision 4.41 (DSP Group Inc.)
      OakDSPCore Technical Manuals for CWDSP1640 or CWDSP167x (LSI Logic)
      OakDSPCore DSP Subsystem AT75C (Atmel)

TeakLite II supports lots of additional opcodes, the only available info has leaked in form of .DLLs which were (apparently by mistake) bundled with a specific RVDS release version:

      TeakLite II disassembler dll in RVDS (RealView Developer Suite) 4.0 Pro

There's no known way to use the RVDS disassembler GUI to decipher Teak binaries. However, Normmatt found a way to get the .DLLs to disassemble code manually (via LoadLibrary and GetProcAddr), which in turn allowed to disassemble all possible 65536 combinations for all opcodes.
BUG: That RVDS tool disassembles "R0425" operands to "r6" (instead of "r5"), that's definetely wrong for the old "movr" opcode (TeakLite I didn't support any "r6" register at all), and, when looking at disassembled code, it does also look wrong for newer TL2 opcodes.
Actually, the registers CAN be redefined via ar0/ar1/arp0/arp1/arp2/arp3, so it isn't actually a bug.
Teak MMIO Registers
There aren't official docs, but wwylele has discovered a debugger at that contains definitions for most of the MMIO bits:

      searching for "teak" in the "search for chip" box on "www.lauterbach.com"
      should lead to this file: trace32_ceva-teak_r_2019_02_000108303_win64.zip

The zip contains a "perxteak.per" file that contains the MMIO bit definitions (in txt format). The definitions for OCEM do accidentally refer to an older version (without 18bit addresses). Definitions for GLUE, ICU, APBP, DMA, CRU, GPIO, and BTDMP are missing (whereof a similar/older ICU variant is defined in "peroak.per" in the same zip).
Teak COFF Files
The DSi Sound utility contains a COFF file called "aac.a" (inside of its nitro filesystem), and aside from the binary, the file is also including a COFF symbol table with labels in ASCII format.
Teak Undefined Opcodes
There are several "Undefined" opcodes: Any opcodes that have no instruction assigned in the opcode encoding table (or that are excplicitely assigned as "undefined" in the table). Opcodes with invalid parameters (eg. ArArp set to 6..7).
Some opcodes are also having "Unused" operand bits; these bits should be usually zero (nonzero would supposedly mirror to the same instruction, but one shouldn't do that).
Moreover, there are various special cases saying that certain opcodes may not be used with certain registers, eg. "addh" shall not be used with operands Ax,Bx,p (with unknown results when violating that rule).
Teak Memory
Memory is addressed in 16bit WORD units (not in bytes) with separate Instruction and Data busses. Before starting the Teak, store the Teak program code in New Shared WRAM, and then map that memory to Teak side via MBK registers:
DSi New Shared WRAM (for ARM7, ARM9, DSP)
At Teak side, 16bit is the smallest addressable unit (so there's no "byte-order" on Teak side - however, 16bit values should be stored in little endian format on ARM side).
Confusingly, the "movpdw" opcode is doing a 32bit read with two 16bit words ordered in big-endian (and, on ARM side, byte-fractions ordered in little-endian). There are a few more opcodes that can read/write 32bits, with optional address increment/decrement for the 2nd word, so endianness is selectable in that cases; it's also common to use the SAME address for both words (probably intended for scaling a 16bit memory value to 32bits).
Teak Code Memory
TeakLite II supports 18bit program memory addressing (unlike Teak/Oak which supported only 16bit addresses). The 18bits allow to address max 256Kwords (=512Kbytes) of code, whereas, the DSi can map only half that much memory to the DSP (ie. max 256Kbytes code).
Call/Ret are always pushing/popping 32bit return addresses (even when doing "near" calls within the same 16bit page).
Teak Data Memory (RAM and Memory Mapped I/O)
Teak Data Memory is addressed via 16bit address bus (via registers r0..r7), allowing to access max 64Kwords (2Kwords of MMIO, plus 62Kwords of RAM). The memory is divided into three sections (X/Z/Y-spaces), the size/location of that sections can be changed via Port 8114h (in 1Kword units), and alongsides, the MMIO base can be adjusted via Port 811Eh. The default areas are:

      0000h..7FFFh  X Space (for RAM, with 1-stage write-buffer)     ;min zero
      8000h..87FFh  Z Space (for Memory-mapped I/O, no write-buffer) ;min zero
      8800h..FFFFh  Y Space (for RAM, with 1-stage write-buffer))    ;min 1Kword

Confusingly, the DSi Sound utility is mapping 128Kwords of RAM as Teak Data memory, but it's unknown how to access all of that memory. The CPU opcodes, CPU registers, and MMIO registers don't seem to allow to access more than 64Kwords of Data. Maybe the extra memory is accessible via DMA, and maybe the CPU's [r7+imm16] operands might allow to exceed the 64Kbyte range (though they might as well wrap within 64Kbyte range, actually that's more likely, especially for "signed" immediates).
Teak Call Conventions (as done in "aac.a" from DSi Sound)
Functions are called with up to four parameters in a0,a1,b0,b1 (or a0l, a1l, b0l, b1l when needing only 16bits). Any further parameters are pushed on stack before the function call (and are deallocated via "rets Imm8" opcode upon return). Register r7 is often used as stack frame (for accessing pushed incoming parameters & locally allocated variables).
Functions may smash a0, a1, b0, b1. A return value (if any) is stored in a0 (or a0l). All other registers like r0..r7, sv, etc. should be left unchanged (or pushed/popped when needed).
Teak Speed
Cycles per opcode are defined in the TeakLite document (not covering TeakLite II opcodes though). Most instructions (even Multiply opcodes) can complete in a single clock cycle. The main bottleneck appear to be memory access cycles: Code and Data memory can be accessed in parallel, so the overall rule would be:

      NumCycles = max(NumberOfOpcodeWords, NumberOfDataReadsWrites)

Some exceptions with extra cycles are opcodes that are changing PC, or that do read/write program memory (movd and movp). Opcodes exp, max, maxd, min are having restrictions saying that the result may not be used by the "following instruction".
The overall clock speed in the DSi is unknown; some years ago somebody seems to have claimed it to be around 130MHz, but it's unclear where that info came from.

      Teak actual CPU clock(s) are...
      134.055928MHz (aka 134MHz)       <-- for Timer 0, SIO, DMA (no "waitstates")
      107.244742MHz (aka 134MHz/1.25)  <-- for Timer 1, CPU    (with "waitstates")

The ARM9 can access WRAM at 33MHz, whilst Teak seems to be capable of fetching 16bit opcodes and 16bit data at 107MHz from the same WRAM (apparently without even using a cache).

DSi Teak I/O Ports (on ARM9 Side)

4004300h - DSi9 - DSP_PDATA - DSP Transfer Data Read FIFO (R)

      0-15  Data (one stage of the 16-stage Read FIFO)

4004300h - DSi9 - DSP_PDATA - DSP Transfer Data Write FIFO (W)

      0-15  Data (one stage of the 16-stage Write FIFO)

4004304h - DSi9 - DSP_PADR - DSP Transfer Address (W)

      0-15  Lower 16bit of Address in DSP Memory (in 16bit units)

For MMIO, only lower 10bit are used (ie. MMIO[8000h-87FFh] can be accessed via 8000h-87FFh or 0000h-07FFh or other mirrors).
For Data, the 16bit address allows to access 64K-words.
For Code, the 16bit address allows to access 64K-words, but Code works only in write-direction?
For Data/Code, the upper 16bit of Address must be configured on DSP side, in DMA channel 0 registers:

      MMIO[81BEh]   - DMA Select Channel (must be 0 for below DMA 0 regisrers)
      MMIO[81C2h:0] - DMA Channel 0: Source Address, bit16-31 (R/W)
      MMIO[81C6h:0] - DMA Channel 0: Destination Address, bit16-31 (R/W)

The Auto-increment flag in DSP_PCFG.bit1 will increment the 16bit address after each DSP_PDATA unit (but doesn't seem to increment the upper bits after address xxFFFFh).
4004308h - DSi9 - DSP_PCFG - DSP Configuration (R/W)

      0     DSP Reset (0=Release, 1=Reset) ;should be held "1" for 8 DSP clks
      1     DSP Transfer Address Auto-Increment  (0=Off, 1=On)
      2-3   DSP Read Data Length (0=1 word, 1=8 words, 2=16 words, 3=FreeRun)
      4     DSP Read Start Flag (mem transfer via Read FIFO) (1=Start)
      5     Interrupt Enable Read FIFO Full      (0=Off, 1=On)
      6     Interrupt Enable Read FIFO Not-Empty (0=Off, 1=On)
      7     Interrupt Enable Write FIFO Full     (0=Off, 1=On)
      8     Interrupt Enable Write FIFO Empty    (0=Off, 1=On)
      9     Interrupt Enable Reply Register 0    (0=Off, 1=On)
      10    Interrupt Enable Reply Register 1    (0=Off, 1=On)
      11    Interrupt Enable Reply Register 2    (0=Off, 1=On)
      12-15 DSP Memory Transfer (0=DSP/Data, 1=DSP/MMIO, 5=DSP/Code, 7=ARM/AHBM)

400430Ch - DSi9 - DSP_PSTS - DSP Status (R)

      0     Read Transfer Underway Flag    (0=No, 1=Yes/From DSP Memory)
      1     Write Transfer Underway Flag   (0=No, 1=Yes/To DSP Memory)
      2     Peripheral Reset Flag          (0=No/Ready, 1=Reset/Busy)
      3-4   Unused (0)
      5     Read FIFO Full Flag            (0=No, 1=Yes/Full)
      6     Read FIFO Not-Empty Flag       (0=No, 1=Yes, ARM9 may read PDATA)
      7     Write FIFO Full Flag           (0=No, 1=Yes/Full)
      8     Write FIFO Empty Flag          (0=No, 1=Yes/Empty)
      9     Semaphore IRQ Flag             (0=None, 1=IRQ)
      10    Reply Register 0 Update Flag   (0=Was Written by DSP, 1=No)
      11    Reply Register 1 Update Flag   (0=Was Written by DSP, 1=No)
      12    Reply Register 2 Update Flag   (0=Was Written by DSP, 1=No)
      13    Command Register 0 Read Flag   (0=Was Read by DSP, 1=No)
      14    Command Register 1 Read Flag   (0=Was Read by DSP, 1=No)
      15    Command Register 2 Read Flag   (0=Was Read by DSP, 1=No)

Unknown if/when bit10-15 get reset... maybe after reading the status... or when reading a reply or writing a new command?
4004310h - DSi9 - DSP_PSEM - ARM9-to-DSP Semaphore (R/W)

      0-15  ARM9-to-DSP Semaphore 0..15 Flags (0=Off, 1=On)

Reportedly these flags are sent in ARM9-to-DSP direction (=seems correct).
Confusingly, the other DSP_Pxxx registers are for opposite direction?
4004314h - DSi9 - DSP_PMASK - DSP-to-ARM9 Semaphore Mask (R/W)

      0-15  DSP-to-ARM9 Semaphore 0..15 Interrupt Disable (0=Enable, 1=Disable)

4004318h - DSi9 - DSP_PCLEAR - DSP-to-ARM9 Semaphore Clear (W)

      0-15  DSP-to-ARM9 Semaphore 0..15 Clear (0=No Change, 1=Clear/Ack)

Reportedly clears bits in DSP_PSEM/4004310h. [that's probably nonsense, clearing bits in DSP_SEM/400431Ch would make more sense?]
400431Ch - DSi9 - DSP_SEM - DSP-to-ARM9 Semaphore Data (R)

      0-15  DSP-to-ARM9 Semaphore 0..15 Flags (0=Off, 1=On)

Reportedly these flags are received in DSP-to-ARM9 direction.
4004320h - DSi9 - DSP_CMD0 - DSP Command Register 0 (R/W) (ARM9 to DSP)
4004328h - DSi9 - DSP_CMD1 - DSP Command Register 1 (R/W) (ARM9 to DSP)
4004330h - DSi9 - DSP_CMD2 - DSP Command Register 2 (R/W) (ARM9 to DSP)

      0-15  Command/Data to DSP

4004324h - DSi9 - DSP_REP0 - DSP Reply Register 0 (R) (DSP to ARM9)
400432Ch - DSi9 - DSP_REP1 - DSP Reply Register 1 (R) (DSP to ARM9)
4004334h - DSi9 - DSP_REP2 - DSP Reply Register 2 (R) (DSP to ARM9)

      0-15  Reply/Data from DSP

Further Teak related registers
SCFG_CLK, SCFG_RST, SCFG_EXT registers, MBK registers, and SNDEXCNT register.
DSi Control Registers (SCFG)
DSi New Shared WRAM (for ARM7, ARM9, DSP)
DSi Microphone and SoundExt
And, for the final audio output and microphone input,
DSi Touchscreen/Sound Controller

DSi Teak MMIO - Register Summary

I/O ports are mapped in "data memory" at 8000h-87FFh (2Kwords). All ports are 16bit wide, located at even word addresses (words at odd addresses seem to be always 0000h, except, there ARE some odd ports used at 806xh).
8000h Mirrors

      8000h..8002h 3300 3300 3300 R   Mirror of Port 80D6h

8004h JAM

      8004h        0000 0000 87FF R/W JAM Unknown
      8006h        ?    ?    ?    ??  JAM Unknown/Crash, DANGER (crashes on read)
      8008h..800Eh 3300 3300 3300 R   Mirror of Port 80D6h

8010h GLUE

      8010h        0000 0000 0003 R/W GLUE CFG0
      8012h        0000 0000 0003 R/W GLUE Unknown 2bit
      8014h        0000 0000 FFFF R/W GLUE Unknown 16bit
      8016h        0000 0000 0000 R   GLUE Unknown (DSi=0000h, New3DS=00BAh)
      8018h        0000 0000 BDEF R/W GLUE Whatever Parity/Shuffle
      801Ah        C902 C902 C902 R   GLUE Chip config ID (for xpert_offsets_tbl)
      801Ch..801Eh 0003 0003 0003 R   Mirror of port 8010h

8020h Timers

      8020h        0000 0000 7xDF R/W Timer 0 Control (bit11=DANGER)      ;\
      8022h        0000 0000 0000 W   Timer 0 Trigger Event/Watchdog      ;
      8024h        0000 0000 FFFF R/W Timer 0 Reload value, bit0-15       ; Timer 0
      8026h        0000 0000 FFFF R/W Timer 0 Reload value, bit16-31      ;
      8028h        0000 0000 0000 R   Timer 0 Counter value, bit0-15      ;
      802Ah        0000 0000 0000 R   Timer 0 Counter value, bit16-31     ;
      802Ch        0000 0000 FFFF R/W Timer 0 PWM Reload value, bit0-15   ;
      802Eh        0000 0000 FFFF R/W Timer 0 PWM Reload value, bit16-31  ;/
      8030h        0200 0200 7xDF R/W Timer 1 Control (bit11=DANGER)      ;\
      8032h        0000 0000 0000 W   Timer 1 Trigger Event/Watchdog      ;
      8034h        0000 0000 FFFF R/W Timer 1 Reload value, bit0-15       ; Timer 1
      8036h        0000 0000 FFFF R/W Timer 1 Reload value, bit16-31      ;
      8038h        0000 0000 0000 R   Timer 1 Counter value, bit0-15      ;
      803Ah        0000 0000 0000 R   Timer 1 Counter value, bit16-31     ;
      803Ch        0000 0000 FFFF R/W Timer 1 PWM Reload value, bit0-15   ;
      803Eh        0000 0000 FFFF R/W Timer 1 PWM Reload value, bit16-31  ;/
      8040h..804Eh 3300 3300 3300 R   Mirror of Port 80D6h

8050h Serial Port (SIO)

      8050h        7000 0000 F03F R/W SIO Control
      8052h        0000 0000 7F7F R/W SIO Clock Divider
      8054h        0000 0000 0000 R+W SIO Data (R) and (W)
      8056h        0000 0000 0001 R/W SIO Enable
      8058h        0000 0000 0000 R   SIO Status
      805Ah..805Eh F03F F03F F03F R   Mirror of port 8050h

8060h Debug (OCEM, On-chip Emulation Module)

      8060h        0105 0105 0105 R   OCEM Program Flow Trace Buffer, bit0-15
      8061h        0000 0000 0000 R   OCEM Program Flow Trace Buffer, bit16-31
      8062h        FFFF 0000 FFFF R/W OCEM Program Break Address 1, bit0-15
      8063h        0F03 0000 0F03 R/W OCEM Program Break Address 1, bit16-31
      8064h        FFFF 0000 FFFF R/W OCEM Program Break Address 2, bit0-15
      8065h        0F03 0000 0F03 R/W OCEM Program Break Address 2, bit16-31
      8066h        FFFF 0000 FFFF R/W OCEM Program Break Address 3, bit0-15
      8067h        0F03 0000 0F03 R/W OCEM Program Break Address 3, bit16-31
      8068h        00FF 0000 00FF R/W OCEM Program Break Counter 1
      8069h        00FF 0000 00FF R/W OCEM Program Break Counter 2
      806Ah        00FF 0000 00FF R/W OCEM Program Break Counter 3
      806Bh        FFFF 0000 FFFF R/W OCEM Data Break Mask
      806Ch        FFFF 0000 FFFF R/W OCEM Data Break Address
      806Dh        0000 0000      R/W OCEM Breakpoint Enable Flags (DANGER)
      806Eh        3001 0000 FFFF R/W OCEM Mode/Indication?
      806Fh        0000 0000 BFFF R/W OCEM Breakpoint Status Flags
      8070h        0000 0000 0001 R/W OCEM Program Flow Trace Update Disable
      8072h        0000 0000 FFFF R/W Unknown 16bit?
      8074h        C000 C000 C000 R   OCEM Boot/Debug Mode
      8076h..807Eh 0105 0105 0105 R   Mirror of port 8060h

8080h PLL and Power (PMU, Power Management Unit)

      8080h        C00E 0000 FFFF R/W PMU PLL Multiplier
      8082h        0001 0000 0001 R/W PMU PLL Power-on config
      8084h        8000           R/W PMU PLL Divider/Bypass (DANGER)
      8086h        0000           R/W PMU Wake/Shutdown Module(s)
      8088h        0000 0000 07BF R/W PMU Recover Module(s) on interrupt 0
      808Ah        0000 0000 07BF R/W PMU Recover Module(s) on interrupt 1
      808Ch        0000 0000 07BF R/W PMU Recover Module(s) on interrupt 2
      808Eh        0000 0000 07BF R/W PMU Recover Module(s) on vectored interrupt
      8090h        0000 0000 06BF R/W PMU Recover Module(s) on Timer 0 (no bit8)
      8092h        0000 0000 05BF R/W PMU Recover Module(s) on Timer 1 (no bit9)
      8094h        0000 0000 07BF R/W PMU Recover Module(s) on NMI
      8096h        0000 0000 0002 R/W PMU Recover DMA on external signal (bit1)
      8098h        0000 0000 0302 R/W PMU Breakpoint mask module(s) (bit1,8,9 only)
      809Ah        0000 0000 0003 R/W PMU Wake/Shutdown BTDMP(s)
      809Ch        0000 0000 0003 R/W PMU Recover BTDMP(s) on interrupt 0
      809Eh        0000 0000 0003 R/W PMU Recover BTDMP(s) on interrupt 1
      80A0h        0000 0000 0003 R/W PMU Recover BTDMP(s) on interrupt 2
      80A2h        0000 0000 0003 R/W PMU Recover BTDMP(s) on vectored interrupt
      80A4h        0000 0000 0003 R/W PMU Recover BTDMP(s) on Timer 0
      80A6h        0000 0000 0003 R/W PMU Recover BTDMP(s) on Timer 1
      80A8h        0000 0000 0003 R/W PMU Recover BTDMP(s) on NMI (undoc?)
      80AAh        0000 0000 FFFF R/W Unknown 16bit
      80ACh        0000 0000 FFFF R/W Unknown 16bit
      80AEh        0000 0000 FFFF R/W Unknown 16bit
      80B0h..80BEh FFFF FFFF FFFF R   Mirror of port 8080h

80C0h APBP (aka HPI Host Port Interface)

      80C0h        xxxx xxxx xxxx R/W APBP DSP-to-ARM Reply 0
      80C2h        4300 4300 4300 R   APBP ARM-to-DSP Command 0
      80C4h        0000 0000 FFFF R/W APBP DSP-to-ARM Reply 1
      80C6h        3123 3123 3123 R   APBP ARM-to-DSP Command 1
      80C8h        0000 0000 FFFF R/W APBP DSP-to-ARM Reply 2
      80CAh        3223 3223 3223 R   APBP ARM-to-DSP Command 2
      80CCh        0000 0000 FFFF R/W APBP DSP-to-ARM Semaphore Set Flags
      80CEh        0000           R/W APBP ARM-to-DSP Semaphore Interrupt Mask
      80D0h        0000           W?  APBP ARM-to-DSP Semaphore Ack Flags
      80D2h        AFFE AFFE AFFE R   APBP ARM-to-DSP Semaphore Get Flags
      80D4h        0000           R/W APBP Control (DANGER: can crash cpu)
      80D6h        03C0 03C0 03C0 R   APBP DSP-side Status
      80D8h        3B00 3B00 3B00 R   APBP ARM-side Status (mirror of 400430Ch)
      80DAh..80DEh 0000 0000 0000 R   Fixed 0000h

80E0h Bus Config for DMA to external ARM-bus (AHBM)

      80E0h        0000 0000 0000 R   AHBM Status
      80E2h+N*6    0000 0000 0FBF R/W AHBM Channel 0..2 Configure Burst/Data
      80E4h+N*6    0000 0000 03FF R/W AHBM Channel 0..2 Configure Whatever
      80E6h+N*6    0000 0000 00FF R/W AHBM Channel 0..2 Configure DMA
      80F4h        0000 0000 FC00 R/W Unknown 6bit? bit10-15 are used
      80F6h        0000 0000 0000 R?  AHBM Internal FIFO (R) and maybe also (W?)
      80F8h        0000 0000 0000 R?  Unknown always zero?
      80FAh        0000 0000 FFFF R/W Read/write-able(!) mirror of MMIO[80FCh]
      80FCh        FFFF 0000 FFFF R/W Unknown 16bit?
      80FEh        0000 0000 FFFF R/W Unknown 16bit?

8100h MIU (memory limits for X-,Y-,Z-Space, and Memory Mapped I/O base)

      8100h        FFFF 0000 FFFF R/W MIU Waitstate Settings, bit0-15
      8102h        0FFF 0000 0FFF R/W MIU Waitstate Settings, bit16-31
      8104h        0000 0000 FFFF R/W MIU Waitstate Area Z0
      8106h        0000 0000 FFFF R/W MIU Waitstate Area Z1
      8108h        0000 0000 FFFF R/W MIU Waitstate Area Z2
      810Ah        0000 0000 FFFF R/W MIU Waitstate Area Z3
      810Ch        0014 0014 0014 R   Mirror of port 811Ah
      810Eh        0000 0000 FFFF R/W MIU X Page (16bit) (or unused)
      8110h        0000 0000 00FF R/W MIU Y Page (8bit)  (or unused)
      8112h        0000           R/W MIU Z Page (16bit) (or absolute page)(DANGER)
      8114h        1E20           R/W MIU X/Y Page Size for Page 0 (or all pages)
      8116h        1E20 0100 403F R/W MIU X/Y Page Size for Page 1 (or unused)
      8118h        1E20 0100 403F R/W MIU X/Y Page Size for Off-chip (or unused)
      811Ah        0014 00x4      R/W MIU Config for Misc stuff (DANGER)
      811Ch        0004 0000 007F R/W MIU Config for Program Page and Download Mem
      811Eh        8000           R/W MIU Base Address for MMIO Registers (DANGER)
      8120h        0000 0000 000F R/W MIU Observability Mode
      8122h        0000 0000 007F R/W MIU Pin Config?
      8124h..813Eh 0014 0014 0014 R   Mirror of port 811Ah

8140h Patch (CRU, Code Replacement Unit)

      8140h+N*4    0000 0000 FFFF R/W CRU Entry 0..14 Offset, bit0-15
      8142h+N*4    0000 0000 803F R/W CRU Entry 0..14 Offset, bit16-31
      817Ch        0000 0000 FFFF R/W CRU Entry 15 Offset, bit0-15  ;\with control
      817Eh        0000 0000 C03F R/W CRU Entry 15 Offset, bit16-31 ;/status bits

8180h DMA (eight channels, port 81C0h..81Exh are bank-switched via 81BEh)

      8180h        0000 0000 0000 R   DMA Internal: Channel Size0 Busy or so?
      8182h        0000 0000 0000 R   DMA Internal: Channel Size1 Busy or so?
      8184h        0001 0000 00FF R/W DMA Channel Start Flags (1=Start/Busy)
      8186h        0000 0000 00FF R/W DMA Channel Pause Flags (1=Pause)
      8188h        0000 0000 0000 R   DMA Channel End Flags for Size0
      818Ah        0000 0000 0000 R   DMA Channel End Flags for Size1
      818Ch        0000 0000 0000 R   DMA Channel End Flags for Size2 (all done)
      818Eh        3210 0000 7777 R/W DMA Whatever Slot Config, bit0-15
      8190h        7654 0000 7777 R/W DMA Whatever Slot Config, bit16-31
      8192h        0000 0000 7C03 R/W Unknown, R/W mask 7C03h
      8194h        0000 0000 0000 R   DMA Internal: contains SRC_ADDR_L after DMA
      8196h        0000 0000 0000 R   DMA Internal: contains DST_ADDR_L after DMA
      8198h..81B4h 0000 0000 0000 R   Fixed 0000h
      81B6h        0000 0000 FFFF R/W Unknown, 16bit
      81B8h        0000 0000 FFFF R/W Unknown, 16bit
      81BAh        0000 0000 FFFF R/W Unknown, 16bit
      81BCh        0000 0000 FFFF R/W Unknown, 16bit
      81BEh        0000 0000 0007 R/W DMA Select Channel (bank for 81C0h-81Exh)
      81C0h:0..7   0000 0000 FFFF R/W DMA Channel: Source Address, bit0-15
      81C2h:0..7   0000 0000 FFFF R/W DMA Channel: Source Address, bit16-31
      81C4h:0..7   0000 0000 FFFF R/W DMA Channel: Destination Address, bit0-15
      81C6h:0..7   0000 0000 FFFF R/W DMA Channel: Destination Address, bit16-31
      81C8h:0..7   FFFF 0001 FFFF R/W DMA Channel: Size0 (usually total len)
      81CAh:0..7   0001 0001 FFFF R/W DMA Channel: Size1 (usually 1)
      81CCh:0..7   0001 0001 FFFF R/W DMA Channel: Size2 (usually 1)
      81CEh:0..7   0001 0000 FFFF R/W DMA Channel: Source Step0      ;-2,4,2,1
      81D0h:0..7   0001 0000 FFFF R/W DMA Channel: Source Step1      ;-4,2,2,1
      81D2h:0..7   0001 0000 FFFF R/W DMA Channel: Source Step2      ;-2,4,0,1
      81D4h:0..7   0001 0000 FFFF R/W DMA Channel: Destination Step0 ;-4,2,0,1
      81D6h:0..7   0001 0000 FFFF R/W DMA Channel: Destination Step1 ;-0,0,0,1
      81D8h:0..7   0001 0000 FFFF R/W DMA Channel: Destination Step2 ;-0,0,0,1
      81DAh:0..7   F200 0000 F7FF R/W DMA Channel: Memory Area Config
      81DCh:0..7   0000 0000 1FF7 R/W DMA Channel: Unknown, usually set to 0300h?
      81DEh:0..7   0000 0000 00FF R/W DMA Channel: Start/Stop/Control
      81E0h:0..7   0000 0000 0000 R   DMA Internal: contains SRC_ADDR_L after DMA
      81E2h:0..7   0000 0000 0000 R   DMA Internal: contains DST_ADDR_L after DMA
      81E4h:0..7   0000 0000 0000 R   DMA Internal: contains SRC_ADDR_H after DMA
      81E6h:0..7   0000 0000 0000 R   DMA Internal: contains DST_ADDR_H after DMA
      81E8h..81FEh 0000 0000 0000 R   Fixed 0000h

8200h ICU (interrupts)

      8200h        4020 4020 4020 R   ICU Interrupt Pending Flags  (1=Pending)
      8202h        0000 0000 0000 W   ICU Interrupt Acknowledge    (1=Clear)
      8204h        0000 0000 FFFF R/W ICU Interrupt Manual Trigger (1=Set)
      8206h        0000 0000 FFFF R/W ICU Enable Interrupt as int0 (1=Enable)
      8208h        0000 0000 FFFF R/W ICU Enable Interrupt as int1 (1=Enable)
      820Ah        0000 0000 FFFF R/W ICU Enable Interrupt as int2 (1=Enable)
      820Ch        0000 0000 FFFF R/W ICU Enable Interrupt as vint (1=Enable)
      820Eh        2000 0000 FFFF R/W ICU Interrupt Trigger mode (0=Level, 1=Edge)
      8210h        2000 0000 FFFF R/W ICU Interrupt Polarity (0=Normal, 1=Invert)
      8212h+N*4    0003 0000 8003 R/W ICU Vectored Interrupt 0..15 Addr, bit16-31
      8214h+N*4    FC00 0000 FFFF R/W ICU Vectored Interrupt 0..15 Addr, bit0-15
      8252h        0000 0000 FFFF R/W ICU Interrupt Master Disable (1=Off/undoc)
      8254h        0000 0000 5555 R/W Unknown, R/W mask 5555h
      8256h        0000 0000 5555 R/W Unknown, R/W mask 5555h
      8258h..827Eh 0000 0000 0000 R   Mirror of Port 8200h

8280h BTDMP Audio (two channels N=0..1, each with speaker out and mic in)

      8280h+N*80h  0005 0000 FFFF R/W BTDMP Receive Control         ;\
      8282h+N*80h  0000 0000 7FE7 R/W BTDMP Receive Period          ;
      8284h+N*80h  0000 0000 0FE7 R/W BTDMP Receive Usually 0004h   ;
      8286h+N*80h  0000 0000 0003 R/W BTDMP Receive Usually 0021h   ; RX
      8288h+N*80h  1FFF 0000 1FFF R/W BTDMP Receive Usually 0000h   ; (microphone)
      828Ah+N*80h  0000 0000 0FFF R/W BTDMP Receive Usually 0000h   ;
      828Ch+N*80h  0000 0000 3FFF R/W BTDMP Receive Usually 0000h   ;
      828Eh+N*80h  0000 0000 FFFF R/W BTDMP Receive Usually unused  ;
      8290h+N*80h  0000 0000 FFFF R/W BTDMP Receive Usually unused  ;
      8292h+...    0000 0000 0000 R   Fixed 0000h                   ;
      829Eh+N*80h  0000 0000 8000 R/W BTDMP Receive Enable          ;/
      82A0h+N*80h  0005 0000 FFFF R/W BTDMP Transmit Control        ;\
      82A2h+N*80h  0000 0000 7FE7 R/W BTDMP Transmit Period         ;
      82A4h+N*80h  0000 0000 0FE7 R/W BTDMP Transmit Usually 0004h  ;
      82A6h+N*80h  0000 0000 0003 R/W BTDMP Transmit Usually 0021h  ; TX
      82A8h+N*80h  1FFF 0000 1FFF R/W BTDMP Transmit Usually 0000h  ; (audio out)
      82AAh+N*80h  0000 0000 0FFF R/W BTDMP Transmit Usually 0000h  ;
      82ACh+N*80h  0000 0000 3FFF R/W BTDMP Transmit Usually 0000h  ;
      82AEh+N*80h  0000 0000 FFFF R/W BTDMP Transmit Usually unused ;
      82B0h+N*80h  0000 0000 FFFF R/W BTDMP Transmit Usually unused ;
      82B2h+...    0000 0000 0000 R   Fixed 0000h                   ;
      82BEh+N*80h  0000 0000 8000 R/W BTDMP Transmit Enable         ;/
      82C0h+N*80h  001x 001F 001F R   BTDMP Receive FIFO Status     ;\
      82C2h+N*80h  0057 005x 0057 R   BTDMP Transmit FIFO Status    ;
      82C4h+N*80h  E0A1 FFFF E0A1 R   BTDMP Receive FIFO Data       ; RX/TX
      82C6h+N*80h  0000 0000 0000 W   BTDMP Transmit FIFO Data      ;
      82C8h+N*80h  0000 0000 0003 R/W BTDMP Receive FIFO Control    ;
      82CAh+N*80h  0000 0000 0003 R/W BTDMP Transmit FIFO Control   ;/
      82CCh+...    0000 0000 0000 R   Fixed 0000h
      8380h..867Eh 03C0 03C0 03C0 R   Mirror of Port 80D6h

8680h ? (listed in "xpert_offsets_tbl", but there are just mirrors)

      8680h..87FEh 03C0 03C0 03C0 R   Mirror of Port 80D6h

8800h ? (listed in "perxteak.per", but seems to be always 0) (dbg aka H2C)

      (this is called "Host-to-Core JAM protocol" and consists of 11bit values)
      (not sure if that are MMIO registers, or some 11bit data transfer protocol)
      8800h..8807h 0000 0000 0000 R?  Fixed 0 (reportedly H2C aka dbg stuff?)

xpert_offsets_tbl: (with baseIO=8000h)
The DSi's aac.c file contains a "xpert_offsets_tbl" with three sets of I/O regions, which are apparently related to different hardware versions:

         ?    JAM  GLUE TMR  SIO  OCEM PMU  APBP AHBM MIU  CRU  DMA  ICU AUDIO ?
      #0 3333 0000 0010 0020 0050 0060 0080 00A0 3333 00C0 3333 0100 0180 0200 3333
      #1 0000 0004 0010 0020 0050 0060 0080 00C0 00E0 0100 0140 0180 0200 0280 0680
      #2 3333 0004 0010 3333 3333 0020 0040 3333 3333 0060 3333 3333 0120 3333 3333

All addresses are relative to the MMIO base (usually 8000h), 3333h is apparently some dummy value for unsupported I/O areas.
The DSi does use set #1. The other two sets are probably relicts for older Teak hardware that was never used in DSi consoles (for example, set #2 doesn't event support the APBP region for cmd/reply/semaphore).

DSi Teak MMIO[8000h] - Misc Registers (JAM/GLUE)

MMIO[8004h] - JAM Unknown (R/W)

      0-10  Unknown (R/W) (0..7FFh=?)
      11-14 Unused (0)
      15    Unknown (R/W) (0..1=?)

Maybe this is for the 11bit "Host-to-Core JAM protocol"?
MMIO[8006h] - JAM Unknown/Crash, DANGER (crashes on read)
Crashes on read.
MMIO[8010h] - GLUE CFG0 (R/W)
GLUE_CFG0 - Number of wait-states for Z-space transactions in predefined zones
Uh, the above name does not match up with below descriptions?

      0     Timer 1 clock source (0=107MHz/Core, 1=Timer0_TOUT)
      1     Timer 0 force restart upon Timer 1 output (0=No, 1=Yes)
      2-15  Unused (0)

MMIO[8012h] - GLUE Unknown 2bit (R/W)

      0-1   Unknown (R/W) (0..3=?)
      2-15  Unused (0)

MMIO[8014h] - GLUE Unknown 16bit (R/W)

      0-15  Unknown (R/W) (0..FFFFh=?)

MMIO[8016h] - GLUE Unknown, DSi=0000h or New3DS=00BAh (R)

      0-15  Unknown (DSi: always 0000h, New3DS: always 00BAh)

MMIO[8018h] - GLUE Whatever Parity/Shuffle (R/W)

      0-3   Value A                                         (R/W)
      4     All four bits in Value A XORed together         (R)
      5-8   Value B                                         (R/W)
      9     All four bits in Value B XORed together         (R)
      10-13 Value C                                         (R/W)
      14    All four bits in Value C XORed together         (R)
      15    Value D                                         (R/W)

Unknown purpose, might be a randomizer/maths feature, or an interactive chip-detection feature, or something completely different, like memory-control function, or whatever.
MMIO[801Ah] - GLUE Chip config ID (R)

      0-15  Fixed, always C902h on DSi and New3DS

Used for chip detect (for xpert_offsets_tbl).
More Unknown Registers
XpertTeak was announced to support GPIO, unknown where those registers are located. Probably consist of 16bit direction and 16bit data registers (if it's similar as in older Oak chips). A few GPIO-style bits seem to be in st2/mod0/mod3 CPU registers.
Unknown what below is... maybe MMIO[8800h..8807h] or maybe 11bit values for JAM registers at MMIO[8004h..8006h]... and/or Input-only direction GPIO?
[dbg:800h] - H2C Host-to-Core JAM protocol h2c_0

      0     Reset                                           (0=No, 1=Yes)
      1     Boot                                            (0=No, 1=Yes)
      2     Debug                                           (0=No, 1=Yes)
      4     URST (user reset)                               (0=No, 1=Yes)
      5     -
      6     Internal Program (Load code to on-chip memory)  (0=No, 1=Yes)
      7-10  -

[dbg:801h] - H2C Host-to-Core JAM protocol h2c_1

      0-6   -
      7     Continue core's clock after stopped by software (0=No, 1=Yes)
      8     Stop (Stop core's clock)                        (0=No, 1=Yes)
      9     NMI                                             (0=No, 1=Yes)
      10    Abort                                           (0=No, 1=Yes)

[dbg:802h] - H2C Host-to-Core JAM protocol h2c_2

      0-10  Interrupt 0..10                                 (0=No, 1=Yes)

[dbg:803h] - H2C Host-to-Core JAM protocol h2c_3

      0-10  GPI (General Purpose Input) 0..10               (0=Low, 1=High)

[dbg:804h] - H2C Host-to-Core JAM protocol h2c_4

      0-4   GPI (General Purpose Input) 11..15              (0=Low, 1=High)
      5-8   -
      9-10  UI (User Input) 0..1                            (0=Low, 1=High)

[dbg:805h] - H2C Host-to-Core JAM protocol h2c_5

      0-10  Interrupt external/internal control 0..10       (0=Ext, 1=Int)

[dbg:806h] - H2C Host-to-Core JAM protocol h2c_6

      0-10  GPI Enable Control 0..10                        (0=Disable, 1=Enable)

[dbg:807h] - H2C Host-to-Core JAM protocol h2c_7

      0-4   GPI Enable Control 11..15                       (0=Disable, 1=Enable)
      5-8
      9-10  User Input Enable Control 0..1                  (0=Disable, 1=Enable)

DSi Teak MMIO[8020h] - Timers (TMR)

MMIO[8020h/8030h] - Timer 0/1 Control (R/W)

      0-1   Time prescaler (0=Div1, 1=Div2, 2=Div4, 3=Div16)
      2-4   Count mode
             0h: single count     Stop at zero
             1h: auto restart     Wrap from zero to Reload value
             2h: free running     Wrap from zero to FFFFFFFFh
             3h: event count      Decrement manually, and stop at zero
             4h: watchdog mode 1  Trigger Teak Reset at zero
             5h: watchdog mode 2  Trigger Teak NMI at zero
             6h: watchdog mode 3  Trigger Unacknowledgeable-Timer-IRQ at zero?
             7h: reserved         Same as mode 0 (stop at zero)
      5     Unused (0)
      6     Output signal polarity                (0=Normal, 1=Invert/Buggy?)
      7     Clear output signal; when bit14-15=0  (0=No change, 1=Clear)   (W)
      8     Pause the counter                     (0=Unpause, 1=Pause)
      9     Freeze COUNTER_L/H register value     (0=Freeze, 1=Update)
             Note: Bit8/Bit9 can be forced to always 1 via other Timer's Bit13
      10    Restart/Reload the counter            (0=No change, 1=Restart) (W)
      11    Breakpoint requests enable   (0=Disable, 1=Enable) (DANGER/TRAP)
      12    Clock source (0=InternalClk=134MHz/107MHz, 1=ExternalClk=None)
      13    General Purpose (somehow interact between Timer 0 and 1)
             Timer0: Force Timer1.Control.Bit9=1  (0=No, 1=Yes/ForceUpdate)
             Timer1: Force Timer0.Control.Bit8=1  (0=No, 1=Yes/ForcePause)
      14-15 Clear output signal automatically (0=No, 1/2/3=After 2/4/8 cycles)

The InternalClk is different for Timer 0 and 1, and depends on GLUE setting:

      For Timer 0 (no "waitstates")   --> 134.055928MHz
      For Timer 1 (with "waitstates") --> 107.244742MHz (aka 134.055928MHz/1.25)
      For Timer 1 (if GLUE_CFG0.bit0) --> Timer0_TOUT (bugs if Timer0_Reload<3)
      Unknown what "waitstates" refers to, probably not the Z0/Z1/Z2/Z3 waits?

Bit10 is automatically cleared after writing - however, when using prescaler other than Div1, it may take a few cycles until bit10 gets cleared (and perhaps also takes time until it is processed??? if so, one shouldn't clear bit10 in that timeslot).
Bit7 is usually cleared after writing - but not always, still unknown what/when that happens?
MMIO[8022h/8032h] - Timer 0/1 Trigger Event/Watchdog (W)

      0     In Event Mode: Decrement Counter (0=No change, 1=Decrement)
            In Watchdog Mode: Reload Counter (0=No change, 1=Reload)
      1-15  Unused (0)

MMIO[8024h/8034h] - Timer 0/1 Reload value, bit0-15 (R/W)
MMIO[8026h/8036h] - Timer 0/1 Reload value, bit16-31 (R/W)

      0-31  Start/Reload value for decrementing counter

Used as start/reload value; copied to counter when setting Control.bit10, or after reaching 0 in auto-restart mode, or when writting trigger bit in watchdog mode.
Not used in free-run mode (which starts at current counter value, and wraps from 0 to FFFFFFFFh).
MMIO[8028h/8038h] - Timer 0/1 Counter value, bit0-15 (R)
MMIO[802Ah/803Ah] - Timer 0/1 Counter value, bit16-31 (R)

      0-31  Current (or frozen) decrementing counter value

When using freeze, counter keeps decreasing in background, but reading the counter register returns the frozen value (latched when changing Control.bit9 from 1-to-0).
MMIO[802Ch/803Ch] - Timer 0/1 PWM Reload value, bit0-15 (R/W)
MMIO[802Eh/803Eh] - Timer 0/1 PWM Reload value, bit16-31 (R/W)

      0-31  Restart value for PWM counter (uh, maybe PWM duty?)

Unknown if/when/how this is used (maybe just goes to an unimplemented PWM output pin).

DSi Teak MMIO[8050h] - Serial Port (SIO)

This is a SPI-style serial I/O interface, allowing to connect some peripheral or debugging hardware (unused in DSi/3DS).
MMIO[8050h] - SIO Control (R/W)

      0     Chip Select Polarity       (0=Active High, 1=Active Low)
      1     Chip Select Output         (0=Disable/Hangs, 1=Enable) (for Master)
      2     Master/Slave Clock         (0=FromClkDivider, 1=ExternalClk/Hangs)
      3     Clock Polarity             (0=Idle Low, 1=Idle High)
      4     Clock Edge Phase           (0=InputOnRising, 1=OutputOnRising)
      5     Transfer End Interrupt     (0=Enable, 1=Disable/Hangs/NoStatusDone)
      6-11  Unused (0)
      12-15 Num data bits per transfer (0=Hangs, 1..15=2bit..16bit)

MMIO[8052h] - SIO Clock Divider (R/W)

      0-6   Clock Divider 1            (1..7Fh = Div1..Div127) (0=Div1, too)
      7     Unused (0)
      8-14  Clock Divider 2            (1..7Fh = Div1..Div127) (0=Div1, too)
      15    Unused (0)

The transfer shift clock is 134MHz/(Divider1*Divider2).
MMIO[8054h] - SIO Data (R) and (W)

      0-15  Transfer data (probably using only LSBs when NumBits<16)

Writing the transmit data starts the transfer, the reply data can be read when Transfer Done status flag gets set.
MMIO[8056h] - SIO Enable (R/W)

      0     Enable SIO operation       (0=Disable/Hangs, 1=Enable)
      1-15  Unused (0)

MMIO[8058h] - SIO Status (R)

      0     Transfer done   (0=No, 1=Done, Data can be read now)
      1     Overrun error   (0=No, 1=New data arrived before reading old data)
      2-15  Unused (0)

Bit0,1 are automatically cleared after reading the status register.
SIO Transfer Timing Bugs
After transfer end, one must apparently wait at least "Divider1*Divider2/2" cycles before starting another transfer, else the new transfer won't start.
There are two dummy transfer clocks inserted (so transferring 2..16 bits does actually take "(4..18)*Divider1*Divider2" cycles).
And, transfer start doesn't seem to take place until next clock boundary (that may take between "0 and 0.999*Divider1*Divider2" extra cycles).

DSi Teak MMIO[8060h] - Debug (OCEM, On-chip Emulation Module)

MMIO[8060h] - OCEM Program Flow Trace Buffer (PFT), bit0-15 (R)
MMIO[8061h] - OCEM Program Flow Trace Buffer (PFT), bit16-31 (R)
This buffer contains addresses of the 16 most recent jump opcodes, reading returns the oldest of those 16 addresses (or 16 random address/page values if read after reset). One can disable buffer updating via MMIO[8070h] (eg. to avoid jumps inside of a debug handler to be written to the buffer). There is "buffer full" condition that gets set 16 jumps after reset, and that can trap an optional buffer full exception.

      0-17   Program Flow Trace Address
      18-23  Unused (0)
      24-27  Program Flow Trace Page
      28-31  Unused (0)

Unknown if there is any way to "make the buffer empty", either by clearing the buffer, or by removing entries until it gets empty. Also, there is no known way to read the next buffer entry, except for one trick: temporarily re-enable buffer updates via MMIO[8070h] and issue a dummy jump; this will add a new entry, and reading will then return the next oldest entry; by that, the buffer won't get empty (but, when ignoring the address of the dummy jump, one can extract the actual non-dummy data from the buffer).
MMIO[8062h/8064h/8066h] - OCEM Program Break Address 1/2/3, bit0-15 (R/W)
MMIO[8063h/8065h/8067h] - OCEM Program Break Address 1/2/3, bit16-31 (R/W)

      0-17   Program Break Address
      18-23  Unused (0)
      24-27  Program Break Page (should be usually 00h)
      28-31  Unused (0)

MMIO[8068h/8069h/806Ah] - OCEM Program Break Counter 1/2/3 (R/W)

      0-7    Program Address Break Counter (decrements upon PC=break.addr)
      8-15   Unused (0)

Break triggers upon count zero. Writing count=NNh will trap after program counter had hit the break address NNh times (writing count=00h will trigger immediately, without even hitting the break address).
MMIO[806Bh] - OCEM Data Break Mask (R/W)
MMIO[806Ch] - OCEM Data Break Address (R/W)

      0-15   Mask/Address

MMIO[806Dh] - OCEM Breakpoint Enable Flags DANGER (0=Disable, 1=Enable/Trap)

      0      Data value break point on data write transaction
      1      Data value break point on data read transaction
      2      Data address break point as a result on data write transaction
      3      Data address break point as a result on data read transaction
      4      Simultaneous data address and data value match
      5      External register write transaction  ;\(aka ext0/1/2/3?)
      6      External register read transaction   ;/
      7      Program Address break 1 count zero
      8      Program Address break 2 count zero
      9      Program Address break 3 count zero
      10     Break on any program jumps instead of executing the next address
      11     Break on detection of interrupt service routine
      12     Break as a result of program flow trace buffer full
      13     Break when returning to the beginning of block repeat loop
      14     Break on illegal condition (uh, are that... illegal opcodes?)
      15     Single Step

Note: Data value refers to the "dvm" CPU-core register. Data write matches can occur on things like "mov r0,1234h" or "addv r0,1" (when r0 becomes equal to dvm).
MMIO[806Eh] - OCEM Mode/Indication? (R/W)

      0      Program Flow Trace Buffer full (0=Not full/OldestIsGarbage, 1=Full)
      1-11   Unknown (R/W)
      12     MOVD instruction detected (uh, usually 1, even when not using movd?)
      13     User reset activated while in break point service routine
      14     Boot mode   (0=No, 1=Yes)
      15     Debug mode  (0=No, 1=Yes)

Unknown if this is a mode or status register, or mixup thereof?
MMIO[806Fh] - OCEM Breakpoint Status Flags (R/W)

      0      Break caused by Data value match
      1      Break caused by Data address match
      2      Break caused by Data value and data address match
      3      Break caused by User defined register transaction (aka ext0/1/2/3?)
      4      Break caused by an external event (aka what?)
      5      Break caused by Program address break 1 count zero
      6      Break caused by Program address break 2 count zero
      7      Break caused by Program address break 3 count zero
      8-10   Unknown (R/W)
      11     Break caused by Branch break point
      12     Break caused by Interrupt break point
      13     Break caused by Program Flow Trace Buffer full
      14     Break caused by Illegal break point
      15     Break caused by Software trap

Uh, R/W mask is BFFFh, ie. bit14 is always 0, that doesn't match up with above description?
MMIO[8070h] - OCEM Program Flow Trace Update Disable (R/W)

      0      Disable Program Flow Buffer Updating (0=Enable, 1=Disable)
      1-15   Unused (0)

MMIO[8072h] - Unknown 16bit? (R/W)

      0-15   Unknown (R/W)

Maybe be "programming model signature" mentioned in perxteak.per (though that is claimed to use only upper 8bit)? That signature might be some general purpose value to notify the debugger what kind of code is executed?
MMIO[8074h] - OCEM Boot/Debug Mode (R)

      0-13   Unused? (0)
      14     Boot mode   (0=No, 1=Yes)
      15     Debug mode  (0=No, 1=Yes)

Usually contains the same mode bits as written to MMIO[806Eh].bit14/bit15 (maybe one of the registers contains the OLD mode bits; when entering a debug handler or so).

DSi Teak MMIO[8080h] - PLL and Power (PMU, Power Management Unit)

MMIO[8080h] - PMU PLL Multiplier (R/W)

      0-15  Configuration of the PLL clock multiplication (0..FFFFh=what?)

Power-up: C00Eh. Unknown what that does... multiplying clock by 16bit seems unlikely. Maybe alike CCR2 register in files peroak.per and pertklc.per?
Or maybe 0Ch and 0Eh translate to (14+1):12 ratio (ie. the 134MHz/1.25 divider; though changing this register doesn't seem to affect that)?
MMIO[8082h] - PMU PLL Power-on config (R/W)

      0     PLL power-on configuration value for PLL use (0..1=what)
      1-15  Unused (0)

Power-up: 0001h. Unknown what that is. Default value for PLB bit in next register? Or maybe something needed for powering-up the PLL (when clearing bypass flag)?
MMIO[8084h] - PMU PLL Divider/Bypass (R/W?)

      0-6   Clock Divider (0 or 1=Div1) (2..7Fh=Crashes?)
      7-14  Unused (0)
      15    Bypass PLL    (0=Use PLL/Crashes, 1=Bypass; works only if Div1)

Power-up: 8000h. Ie. PLL bypassed, and using 134MHz clock from DSi as is.
Unknown how to change/enable the PLL without crashing.
MMIO[8086h,809Ah] - PMU Wake/Shutdown module(s) (0=Wake-up, 1=Shutdown) (R/W)
MMIO[8088h,809Ch] - PMU Recover module(s) on interrupt 0 (R/W)
MMIO[808Ah,809Eh] - PMU Recover module(s) on interrupt 1 (R/W)
MMIO[808Ch,80A0h] - PMU Recover module(s) on interrupt 2 (R/W)
MMIO[808Eh,80A2h] - PMU Recover module(s) on vectored interrupt (R/W)
MMIO[8090h,80A4h] - PMU Recover module(s) on Timer 0 (except bit8) (R/W)
MMIO[8092h,80A6h] - PMU Recover module(s) on Timer 1 (except bit9) (R/W)
MMIO[8094h,80A8h] - PMU Recover module(s) on non-maskable interrupt (R/W)
MMIO[8096h] - PMU Recover DMA module on external signal (bit1 only) (R/W)

     For registers MMIO[8086h..8096h]:
      0     Core     ;aka cpu?
      1     DMA
      2     SIO
      3     GLUE
      4     APBP/HPI
      5     AHBM
      6     Unused (0)
      7     OCEM
      8     Timer 0
      9     Timer 1
      10    JAM
      11-15 Unused (0)
     For registers MMIO[809Ah..80A8h]:
      0     BTDMP 0
      1     BTDMP 1
      2-15  Unused (0)

Register 8090h.bit8 and 8092h.bit9 are unused, always 0 (ie. a disabled timer cannot wakeup itself).
Register 8096h supports bit1 only (DMA), all other bits are unused, always 0.
MMIO[8098h] - BM: PMU Breakpoint mask module(s) (bit1,8,9 only) (R/W)

      0     Unused (0)
      1     DMA
      2-7   Unused (0)
      8     Timer 0
      9     Timer 1
      10-15 Unused (0)

Unknown what this does. It looks similar to the "Recover" registers, but, going by the description, it is "breakpoink masking" something instead of "recovering".
MMIO[80AAh] - 16bit R/W ?
MMIO[80ACh] - 16bit R/W ?
MMIO[80AEh] - 16bit R/W ?

DSi Teak MMIO[80C0h] - Host Port Interface (APBP aka HPI)

The APBP (aka HPI Host Port Interface) registers are used to communicate between ARM and DSP.
MMIO[80C0h/80C4h/80C8h] - APBP DSP-to-ARM Reply 0/1/2 (R/W)
MMIO[80C2h/80C6h/80CAh] - APBP ARM-to-DSP Command 0/1/2 (R)

      0-15   Command/Reply Data

MMIO[80CCh] - APBP DSP-to-ARM Semaphore Set Flags (0=Clear, 1=Set) (R/W)
MMIO[80CEh] - APBP ARM-to-DSP Semaphore Interrupt Mask (?=On/Off) (R/W)
MMIO[80D0h] - APBP ARM-to-DSP Semaphore Ack Flags (0=No change, 1=Clear) (W?)
MMIO[80D2h] - APBP ARM-to-DSP Semaphore Get Flags (R)

      0-15   Semaphore Flag 0..15

MMIO[80D4h] - APBP Control (R/W)

      0-1    Unused (0)
      2      ARM-side register endianness (0=Normal, 1=Big-Endian/DANGER)
      3-7    Unused (0)
      8      Interrupt when CMD0 is written by ARM (0=Enable, 1=Disable)
      9-11   Unused (0)
      12     Interrupt when CMD1 is written by ARM (0=Enable, 1=Disable)
      13     Interrupt when CMD2 is written by ARM (0=Enable, 1=Disable)
      14-15  Unused (0)

MMIO[80D6h] - APBP DSP-side Status (R)

      0-4    Unused? (usually 0)
      5      Reply Register 0 Read Flag     (0=Was Read by ARM?, 1=No)
      6      Reply Register 1 Read Flag     (0=Was Read by ARM?, 1=No)
      7      Reply Register 2 Read Flag     (0=Was Read by ARM?, 1=No)
      8      Command Register 0 Update Flag (0=Was Written by ARM?, 1=No)
      9      Semaphore IRQ Flag             (0=No, 1=[80D2h] AND NOT [80CEh])
      10-11  Unused? (usually 0)
      12     Command Register 1 Update Flag (0=Was Written by ARM?, 1=No)
      13     Command Register 2 Update Flag (0=Was Written by ARM?, 1=No)
      14-15  Unused? (usually 0)

MMIO[80D8h] - APBP ARM-side Status (mirror of ARM9 Port 400430Ch) (R)

      0      Read Transfer Underway Flag    (0=No, 1=Yes/From DSP Memory)
      1      Write Transfer Underway Flag   (0=No, 1=Yes/To DSP Memory)
      2      Peripheral Reset Flag          (0=No/Ready, 1=Reset/Busy)
      3-4    Unused (0)
      5      Read FIFO Full Flag            (0=No, 1=Yes/Full)
      6      Read FIFO Not-Empty Flag       (0=No, 1=Yes, ARM9 may read PDATA)
      7      Write FIFO Full Flag           (0=No, 1=Yes/Full)
      8      Write FIFO Empty Flag          (0=No, 1=Yes/Empty)
      9      Semaphore IRQ Flag             (0=None, 1=IRQ)
      10     Reply Register 0 Update Flag   (0=Was Written by DSP, 1=No)
      11     Reply Register 1 Update Flag   (0=Was Written by DSP, 1=No)
      12     Reply Register 2 Update Flag   (0=Was Written by DSP, 1=No)
      13     Command Register 0 Read Flag   (0=Was Read by DSP, 1=No)
      14     Command Register 1 Read Flag   (0=Was Read by DSP, 1=No)
      15     Command Register 2 Read Flag   (0=Was Read by DSP, 1=No)

DSi Teak MMIO[80E0h] - AHBM - Advanced High Performance Bus Master

AHBM does allow the Teak CPU to access the ARM-side memory (in combination with DMA interface at MMIO[8180h]).
Supported ARM-side memory areas
DSi allows to access most of the ARM9 address space:

      02000000h/Main RAM     --> works
      03000000h/Shared RAM   --> works (maybe also New Shared RAM, if any mapped?)
      04000000h/ARM9 I/O     --> works
      05000000h/Palette      --> works
      06000000h/VRAM         --> works
      07000000h/OAM          --> works
      08000000h/GBA SLOT ROM --> works (with dummy FFFFFFFFh values)
      0A000000h/GBA SLOT RAM --> works (with dummy FFFFFFFFh values)
      FFFF0000h/ARM9 BIOS    --> works (lower 32K only, upper 32K is zerofilled)
      DTCM/ITCM              --> probably ignored?
      Any other              --> returns zero (but without MMIO[80E0h] error flag)

3DS in 3DS mode is more restrictive:

      20000000h/FCRAM        --> works
      1FF80000h/AXI          --> works
      1FF40000h/DSP/DATA     --> oddly mirrors to 1FF80000h/AXI
      Any other              --> rejected (and sets MMIO[80E0h].bit4 error flag)

MMIO[80E0h] - AHBM Status (R)

      0-1   Usually/always 0 ?
      2     Burst queue not empty  (0=Empty, 1=Not-empty)
      3     Usually/always 0 ?
      4     Busy/stuck/error?  (0=Normal, 1=Invalid ARM address)  ;3DS only?
      5-15  Usually/always 0 ?

"Applications wait for all bits to be 0 before connecting AHBM to DMA."
MMIO[80E2h+(0..2)*6] - AHBM Channel 0..2 Configure Burst/Data (R/W)

      0     Applications set this to 1 if BURST is non-zero, uh?
      1-2   Burst type     (0=x1, 1=x4, 2=x8, 3=?)
      3     Unknown (R/W)  (0=Normal, 1=Dunno/NoTransfer?)
      4-5   Data type      (0=8bit, 1=16bit, 2=32bit, 3=?)
      6     Unused (0)
      7     Unknown (R/W)  (0=Normal, 1=Dunno/TransferHangs/crashes?)
      8-11  Unknown (R/W)  (0..Fh=?) (usually 0)
      12-15 Unused (0)

Used values: 0010h=?,0020h=?,0025h=dma?
MMIO[80E4h+(0..2)*6] - AHBM Channel 0..2 Configure Whatever (R/W)

      0-7   Unknown (R/W)      (0..FFh=?) (usually 0)
      8     Transfer direction (0=Read external memory, 1=Write external memory)
      9     Applications always set this (usually 1=set) (but also works when 0)
      10-15 Unused (0)

Used values: 0200h=read, 0300h=write
MMIO[80E6h+(0..2)*6] - AHBM Channel 0..2 Configure DMA (R/W)

      0-7   Connect to DMA channel 0..7   (0=No, 1=Connect)
      8-15  Unused (0)

Used values: bit0-7=dma0..7, 0000h=All off.
MMIO[80F4h] - Unknown 6bit? bit10-15 are used (R/W)
MMIO[80F6h] - AHBM Internal FIFO (R) and maybe also (W?)
MMIO[80F8h] - Unknown always zero? (R?)
MMIO[80FAh] - Read/write-able(!) mirror of MMIO[80FCh] (R/W)
MMIO[80FCh] - Unknown 16bit? (R/W)
MMIO[80FEh] - Unknown 16bit? (R/W)
Unknown registers, normally left unused. The FIFO register seems to contain the most recent 8x16bit values that were transferred via AHBM. Unknown if that FIFO (and whatever address setting) could be used for manual (non-DMA) AHBM transfers.

DSi Teak MMIO[8100h] - Memory Interface Unit (MIU)

MMIO[8100h] - MIU Waitstate Settings, bit0-15 (R/W)
MMIO[8102h] - MIU Waitstate Settings, bit16-31 (R/W)

      0-3    Number of wait-states for off-chip Z0 block
      4-7    Number of wait-states for off-chip Z1 block
      8-11   Number of wait-states for off-chip Z2 block
      12-15  Number of wait-states for off-chip Z3 block
      16-19  Number of wait-states for off-chip Z blocks outside Z0/Z1/Z2/Z3
      20-23  Number of wait-states for off-chip X/Y memory transactions
      24-27  Number of wait-states for off-chip Program-memory transactions
      28-31  Unused (0)

Uh, what means "off-chip" exactly, what kind of memory, on what "chip"?
MMIO[8104h] - MIU Waitstate Area Z0 (R/W)
MMIO[8106h] - MIU Waitstate Area Z1 (R/W)
MMIO[8108h] - MIU Waitstate Area Z2 (R/W)
MMIO[810Ah] - MIU Waitstate Area Z3 (R/W)

      0-5    Wait-state block Start address in 1K-word units
      6-11   Wait-state block End address in 1K-word units
      12-15  Wait-state block Page (lower 4bit of page)

MMIO[810Eh] - MIU X Page (or unused) (16bit) (R/W)
MMIO[8110h] - MIU Y Page (or unused) (8bit) (R/W)
MMIO[8112h] - MIU Z Page (or "absolute" page) (16bit) (R/W)
The X/Z pages are 16bit wide:

      0-15   Memory Page (...base or so, in WHAT-units?)

The Y page is only 8bit wide:

      0-7    Memory Page (...base or so, in WHAT-units?)
      8-15   Unused (0)

The register meaning depends on the PGM paging mode:

      When PGM=0 --> MMIO[8112h] is the "absolute" data memory page
      When PGM=1 --> MMIO[810Eh/8110h/8112h] are the X/Y/Z pages

MMIO[8114h] - MIU X/Y Page Size for Page 0 (or all pages) (R/W)
MMIO[8116h] - MIU X/Y Page Size for Page 1 (or unused) (R/W)
MMIO[8118h] - MIU X/Y Page Size for Off-chip Pages (or unused) (R/W)

      0-5    X memory size (0..3Fh)
      6-7    Unused (0)
      8-14   Y memory size (1..40h)
      15     Unused (0)

The register meaning depends on the PGM paging mode:

      When PGM=0?--> MMIO[8114h,8116h,8118h] used for Page 0, 1, and Off-chip pages
      When PGM=1?--> MMIO[8114h] used for all pages

For Y memory size, the hardware does automatically replace the written value by min=01h or max=40h when trying to to write 00h or 41h-7Fh.
MMIO[811Ah] - MIU Config for Misc stuff (R/W)

      0      Program protection mechanism, uh, what is that? (0=Disable, 1=Enable)
      1      Program page for entire program space (from Test pin) (1=offchip)
      2      Program page for breakpoint handler (0=Page1/offchip, 1=Page0/onchip)
      3      Unknown (R/W)  (0..1=?)
      4      Core/DMA data use only Z-even address bus (single? PGM=0?) (1=Enable)
      5      Unknown (R/W)  (0..1=?)
      6      Paging mode (PGM) (for X/Y/Z pages)  (0=Normal, 1=DANGER)
      7-15   Unused (0)

Power-on default is 0014h. Bit1-2 are read-only (always bit1=0, bit2=1).
MMIO[811Ch] - MIU Config for Program Page and Download Memory (R/W)

      0      Select Z-space data memory (0=Regular Memory, 1=Download memory)
      1      Download mem is/was selected (bit1 can be cleared during Trap only)
      2-5    Alternative Program Page for movd/movp opcodes (PDLPAGE) (4bit)
      6      Select program page for movd/movp (0=2bit/movpd, 1=4bit/PDLPAGE)
      7-15   Unused (0)

Bit1 gets set when setting bit0=1 (bit1 is usually readonly, except, trap handler may clear bit1 by writing to it). Unknown what Download means, maybe off-chip data memory?
MMIO[811Eh] - MIU Base Address for MMIO Registers (R/W)

      0-9    Unused (0)
      10-15  MMIO Base Address (in 400h-word units)

Power-on default is 8000h, ie. mapping MMIO[8000h..87FFh] to 8000h..87FFh.
MMIO[8120h] - MIU Observability Mode (R/W)

      0      Observability Enable (0=Disable, 1=Enable)
      1-3    Observability Mode   (0..4=Mode, see below)
      4-15   Unused (0)

Observability modes (defines which Core/DMA address/data buses are reflected on the off-chip XZ buses):

      00h: Core XZ address/data buses
      01h: Core Y address/data buses
      02h: Core P address/data buses
      03h: DMA DST address/data buses
      04h: DMA SRC address/data buses

MMIO[8122h] - MIU Pin Config? (R/W)

      0     Z Read Polarity Bit   - for DRZON/DRZEN
      1     Z Write Polarity Bit  - for DWZON/DWZEN
      2     Z Strobe Polarity Bit - for ZSTRB
      3     X Strobe Polarity Bit - for XSTRB
      4     X Select Polarity Bit - for XS
      5     Z Select Polarity Bit - for ZS
      6     Signal Polarity Bit   - for RD_WR
      7-15  Unused (0)

DSi Teak MMIO[8140h] - Code Replacement Unit (CRU)

The CRU is intended to fix bugs in ROM-based programs (rather useless for RAM-based DSi code).
MMIO[8140h+(0..15)*4] - CRU Entry 0..15 Offset, bit0-15 (R/W)
MMIO[8142h+(0..15)*4] - CRU Entry 0..15 Offset, bit16-31 (R/W)

      0-17   Program Address                           (0..3FFFFh)            (R/W)
      18-21  Program Page (usually 0)                  (0..Fh)                (R/W)
      22-30  Unused (0) (except bit25-30 in entry 15)
      25-28  Entry 15: Match entry number              (0..15=Entry 0..15)    (R)
      29     Entry 15: Match flag (cleared after read) (0=None, 1=Yes/match)  (R)
      30     Entry 15: Master enable for all entries   (0=Disable, 1=Enable)  (R/W)
      31     Enable Entry                              (0=Disable, 1=Enable)  (R/W)

There are sixteen identical entries, resembling OCEM program breaks, with some extra control/status bits in last entry.
The feature is working in so far that the read-only status bits get set upon matches, but the match should reportedly insert "a branch instruction" or trigger a "trap" exception, which doesn't happen.
Unknown if there are further config/mode/enable bits elsewhere for activating that behaviour. To bypass ROM code, it might redirect to data RAM, or external AHBM memory?

DSi Teak MMIO[8180h] - Direct Memory Access (DMA)

     _____________________________ DMA Control/Status _____________________________

MMIO[8184h] - DMA Channel Start Flags (0=Stop/Done, 1=Start/Busy) (R/W)
MMIO[8186h] - DMA Channel Pause Flags (0=Normal, 1=Pause) (R/W)

      0-7    Channel 0..7 flags
      8-15   Unused (0)

Transfer start/stop should be done via [81DEh].bit14/15 (using RMW to change [8184h] directly could mess up other channels; if they finish during the RMW).
Channel 0 is automatically enabled on power up, because it is used for ARM-side data transfers via DSP_PDATA (Port 4004300h).
MMIO[8188h] - DMA Channel End Flags for Size0 (R)
MMIO[818Ah] - DMA Channel End Flags for Size1 (R)
MMIO[818Ch] - DMA Channel End Flags for Size2 (R) (all done)

      0-7    Channel 0..7 end flags (0=No, 1=End)
      8-15   Unused (0)

The COFF labels refer to these three registers as "seox", whatever that means.
The 3rd register can be used to check for transfer completion (transfer end does also clear the Start/Enable bit in MMIO[8184h]).
MMIO[818Eh] - DMA Whatever Slot Config, bit0-15 (R/W)
MMIO[8190h] - DMA Whatever Slot Config, bit16-31 (R/W)

      0-2    Whatever (0..7) (initially 0 on reset)
      4-6    Whatever (0..7) (initially 1 on reset)
      8-10   Whatever (0..7) (initially 2 on reset)
      12-14  Whatever (0..7) (initially 3 on reset)
      16-18  Whatever (0..7) (initially 4 on reset)
      20-22  Whatever (0..7) (initially 5 on reset)
      24-24  Whatever (0..7) (initially 6 on reset)
      28-30  Whatever (0..7) (initially 7 on reset)
      Bit3,7,11,15,19,23,25,31 are unused (always 0)

Reportedly "some sort of slots for channel 0..7" maybe priority for DMA 0..7?
transfer can hang (eg. when changing 1st word to 4444h or higher)?

     ________________________________ DMA Channels ________________________________

MMIO[81BEh] - DMA Select Channel (R/W)

      0-2    Select the channel to be mapped to MMIO[81C0h..81Exh] (0..7)
      3-15   Unused (0)

MMIO[81C0h:0..7] - DMA Channel: Source Address, bit0-15 (R/W)
MMIO[81C2h:0..7] - DMA Channel: Source Address, bit16-31 (R/W)
MMIO[81C4h:0..7] - DMA Channel: Destination Address, bit0-15 (R/W)
MMIO[81C6h:0..7] - DMA Channel: Destination Address, bit16-31 (R/W)

      0-31   Address (within the selected memory area, see MMIO[81DAh])

Unknown how/what works exactly...
DSP/data probably uses only lower 18bit & probably ignores X/Y/Z and MMIOBASE
DSP/code probably uses only lower 18bit & probably ignores prpage/movpd
DSP/mmio probably uses only lower 11bit & probably ignores MMIOBASE
ARM/ahbm uses full 32bit address, counted in BYTE-units (not 16bit-units)
MMIO[81C8h:0..7] - DMA Channel: Size0 (inner dimension) (R/W)
MMIO[81CAh:0..7] - DMA Channel: Size1 (middle dimension) (R/W)
MMIO[81CCh:0..7] - DMA Channel: Size2 (outer dimension) (R/W)

      0-15   Length (for each array dimension)   (0001h..FFFFh)

Trying to write size=0000h is automatically replaced by size=0001h.
Total transfer length is Size0*Size1*Size2 (that is always counted in 16bit units; Size0 should contain an even number when using 32bit mode).
Normal 1-dimensional transfer would use Size0=Len, Size1=Size2=1. Size1 can be useful for 2-dimensional arrays. Size2 was announced to be useful for re-ordering things like RGB values (uh, but that may require 8bit-addressing, and negative step values, or separate step-direction flags?).
MMIO[81CEh:0..7] - DMA Channel: Source Step0 (R/W)
MMIO[81D0h:0..7] - DMA Channel: Source Step1 (R/W)
MMIO[81D2h:0..7] - DMA Channel: Source Step2 (R/W)
MMIO[81D4h:0..7] - DMA Channel: Destination Step0 (R/W)
MMIO[81D6h:0..7] - DMA Channel: Destination Step1 (R/W)
MMIO[81D8h:0..7] - DMA Channel: Destination Step2 (R/W)

      0-15   Step (... in 8bit/16bit/32bit units?) (signed or unsigned?)

MMIO[81DAh:0..7] - DMA Channel: Memory Area Config (R/W)

      0-3    Source Memory Area      (0..0Fh, see below)
      4-7    Destination Memory Area (0..0Fh, see below)
      8      Unknown?                (0=Normal, 1=No Irq, No end, maybe repeat?)
      9      Different Memory Areas  (0=No/Slow, 1=Yes/Simultaneous Read+Write)
      10     Transfer Unit size      (0=16bit/Slow, 1=32bit/Fast)
      11     Unused (0)
      12-13  Unknown?                (0..3=?)
      12-15  Transfer Speed          (0=Slow, 1/2=Medium, 3=Fast) (or burst size?)

Source/Destination Memory Areas can be:

      00h DSP/Data memory                                 ;\
      01h DSP/MMIO registers                              ; 16bit-address units
      05h DSP/Code memory (only for DST_SPACE) (untested) ;/
      07h ARM/AHBM external memory (via AHBM registers)   ;-8bit-address units

Used values: 670h,607h,400h,250h. Reset value is F200h (and kept so for channel 0).
MMIO[81DCh:0..7] - DMA Channel: Unknown, usually set to 0300h? (R/W)

      0-2    Unknown (R/W)  (0..07h=?) (usually 0)
      3      Unused (0)
      4-7    Unknown (R/W)  (0..0Fh=?) (usually 0h)
      8-9    Unknown (R/W)  (0/1/2=Hangs?, 3=Normal)
      10-12  Unknown (R/W)  (0..07h=?) (usually 0h)
      13-15  Unused (0)

Usually set to 0300h or 0700h (or, set to 0011h for DSP_PDATA transfer for channel 0, though that does also work with reset value 0000h).
MMIO[81DEh:0..7] - DMA Channel: Start/Stop/Control (R/W)

      0-2   Interrupt upon Size 0..2 End (0=Disable, 1=Enable)                (R/W)
      3-5   Never set Size2 End flag? (0=Normal, 1=No end, maybe repeat?)     (R/W)
      6-7   Unknown (0..3)                                                    (R/W)
      8-13  Unused? (0)
      14-15 Start/Stop Transfer (0=No change, 1=Start, 2=Stop, 3=Same as 1)     (W)

     ______________________ DMA Unknown/Internal Registers ________________________

MMIO[8192h] - Unknown, one register with RW-mask 7C03h (R/W)
Unknown/internal stuff. Writing 0000h, 0001h, 0002h, 0800h, 1000h, 4000h, FFFFh passes okay, however, writing 0400h or 2000h causes TRAP exception. Note: Don't remember how that had happened; it might have been caused indirectly by dvm data matches.
MMIO[81B6h..81BCh] - Unknown, four registers with RW-mask FFFFh (R/W)
Unknown/internal stuff. The four 16bit R/W registers might be general purpose fill values (if they have no other purpose)?
MMIO[8180h] - DMA Internal: Channel Size0 Busy or so? (R)
MMIO[8182h] - DMA Internal: Channel Size1 Busy or so? (R)
Unknown, can contain similar busy flags as in [8184h], although in read-only form, and not exactly the same value (eg. bit0 tends to be zero despite of channel being enabled for DSP_PATA transfers). Maybe related to Size0/1, or maybe indicating which channel is RIGHT NOW transferring data (if so, only one bit should be seen set at a time; or maybe bits go off one after another during processing of multiple channels).
MMIO[8194h] - DMA Internal: initially 0, contains SRC_ADDR_L after DMA (R)
MMIO[8196h] - DMA Internal: initially 0, contains DST_ADDR_L after DMA (R)
MMIO[8198h..81B4h] - Unknown, fixed 0 (R)
MMIO[81E0h:0..7] - DMA Internal: initially 0, but SRC_ADDR_L(n) after DMA (R)
MMIO[81E2h:0..7] - DMA Internal: initially 0, but DST_ADDR_L(n) after DMA (R)
MMIO[81E4h:0..7] - DMA Internal: initially 0, but SRC_ADDR_H(n) after DMA (R)
MMIO[81E6h:0..7] - DMA Internal: initially 0, but DST_ADDR_H(n) after DMA (R)
MMIO[81E8h..81FEh] - Unknown, fixed 0 (R)
Unknown/internal stuff.

     _________________________________ DMA Notes _________________________________

STEP0, STEP1 and STEP2 specify the address stepping between elements for each dimension. Below is an example showing how it works.
With the source address configuration:

      SRC_ADDR = 0
      SIZE0 = 3
      SIZE1 = 5
      SIZE2 = 2
      SRC_STEP0 = 2
      SRC_STEP1 = 1
      SRC_STEP2 = 7

The data transfer copies data from the following addresses:

      <--------------------------size1-------------------------->
      <--size0--> <--size0--> <--size0--> <--size0--> <--size0-->
       0,  2,  4,  5,  7,  9, 10, 12, 14, 15, 17, 19, 20, 22, 24  <-- size2 (1st)
      31, 33, 35, 36, 38, 40, 41, 43, 45, 46, 48, 50, 51, 53, 55  <-- size2 (2nd)

The 32bit double word mode also automatically aligns down the addresses to 32bit boundaries.
When the memory space is specified as 7 (AHBM), it performs data transfer from/to external ARM memory.
The external memory has 8-bit addressing. Keep in mind that the STEP value is also added to the address as-is, so STEP = 1 means stepping 8-bit for FCRAM, while stepping 16-bit for DSP memory.
There are also more alignment requirement on the external memory address, but it is handled by AHBM.

DSi Teak MMIO[8200h] - Interrupt Control Unit (ICU)

MMIO[8200h] - ICU Interrupt Pending Flags (0=No, 1=IRQ Pending) (R)
MMIO[8202h] - ICU Interrupt Acknowledge (0=No change, 1=Set) (W)
MMIO[8204h] - ICU Interrupt Manual Trigger (0=Release, 1=Set) (R/W)
MMIO[8206h] - ICU Enable Interrupt routing to core interrupt 0 (R/W)
MMIO[8208h] - ICU Enable Interrupt routing to core interrupt 1 (R/W)
MMIO[820Ah] - ICU Enable Interrupt routing to core interrupt 2 (R/W)
MMIO[820Ch] - ICU Enable Interrupt routing to vectored interrupt (R/W)
MMIO[820Eh] - ICU Interrupt Trigger mode (0=Level, 1=Edge) (R/W)
MMIO[8210h] - ICU Interrupt Polarity (0=Normal, 1=Invert) (R/W)

      0-8   No hardware IRQs (but can be used as Software IRQs via Manual Trigger)
      9     Timer 1
      10    Timer 0
      11    BTDMP 0
      12    BTDMP 1
      13    SIO
      14    APBP
      15    DMA

MMIO[8212h+(0..15)*4] - ICU Vectored Interrupt 0..15 Address, bit16-31 (R/W)
MMIO[8214h+(0..15)*4] - ICU Vectored Interrupt 0..15 Address, bit0-15 (R/W)

      0-17  Address of interrupt handler for vectored interrupt 0..15
      18-30 Unused (0)
      31    Context switch on vectored interrupt 0..15 (0=Disable, 1=Enable)

Observe that upper/lower 16bit are arranged in BIG-ENDIAN style (unlike other registers with lower/upper 16bit).
Default values on reset are 0003FC00h.
Interrupt vector address for Interrupt 0..15, when using "vectored interrupt".
The core interrupts and NMI have fixed vector addresses.
MMIO[8252h] - ICU Interrupt Master Disable (0=Normal, 1=Off/undoc) (R/W)

      0-15  Master Disable for interrupt 0..15 (0=Normal, 1=Off, don't set pending)

MMIO[8254h] - Unknown, R/W mask 5555h (R/W)
MMIO[8256h] - Unknown, R/W mask 5555h (R/W)
Unknown.
Interrupt related CPU registers
DSi Teak CPU Control/Status Registers
teak exception vectors

      code:00000h    start (from reset or timer watchdog)
      code:00002h    trap_handler (trap/break) (from OCEM or Timers)
      code:00004h    nmi_handler (non-maskable interrupt) (from timer watchdog)
      code:00006h    int0_handler
      code:0000Eh    int1_handler
      code:00016h    int2_handler
      code:variable  vint_handler(s) (with context switch, instead of push/pop?)

Interrupt Behaviour
Pending flags are set somewhat as so:

      new_state=incoming_hw_signal             ;always 0 for interrupt 0..8
      if polarity=1 then new_state=new_state xor 1
      new_state=new_state OR manual_trigger    ;done AFTER above polarity invert
      new_state=new_state AND NOT master_disable
      if new_state=1 and old_state=0 then pending=1
      old_state=new_state

Acknowlege is required for clearing pending bits, this is required in both Egde- and Level-triggered modes (the difference is that Level-triggered mode will ignore the acknowledge if new_state is still on).
Manual Trigger won't appear in Pending until after two NOP opcodes (or similar delay).
IRQ-to-interrupt translator
The main job of ICU is to translate 16 IRQ signals to 4 processor interrupt signals (int0, int1, int2 and vint), specified by I0x, I1x, I2x and IVx registers. When an IRQ is signaled, ICU will generate interrupt signal and the processor starts to execute interrupt handling procedure if the core interrupt is enabled. The procedure is supposed check IPx reigster to know the exact IRQ index, and to set IAx registers to clear the IRQ signal.
Software interrupt
The processor can writes to ITx to generate a software interrupt manually. A use case for this in many 3DS games is that IRQ 0 is used as the reschedule procedure for multithreading. When a thread wants to yield, it triggers IRQ 0, which switches thread context and resume another thread.

DSi Teak MMIO[8280h] - Audio (Buffered Time Division Multiplexing Port)

There are two BTDMP units. The weird name "Buffered Time Division Multiplexing Port" does essentially mean "FIFO with sample rate timer".

      BTDMP 0 is used for Receive (microphone) and Transmit (audio out).
      BTDMP 1 isn't actually used for anything.

MMIO[8280h/82A0h+(0..1)*80h] - BTDMP Receive/Transmit Control (R/W)

      0-3    Unknown (0..Fh) (usually 0Dh/0Fh)
      4-7    Unknown (0..Fh) (usually 00h)
      8-11   Enable BTDMP Interrupt when non-zero (0=Off, AnyOther=On?)
      12-15  Unknown (0..Fh) (usually 00h)

DSi sets this to 020Dh (receive) or 010Fh (transmit).
MMIO[8282h/82A2h+(0..1)*80h] - BTDMP Receive/Transmit Period (R/W)

      0-2    Clock Divider? (0..7)    (usually 4)   (affects timing when bit13=1)
      3-4    Unused (0)
      5-12   Clock Divider? (0..FFh)  (usually 80h) (affects timing when bit13=1)
      13     Clock Select   (0=ExternalDSiAudioClk, 1=InternalClkDivider?)
      14     Unknown        (0..1)    (usually 0)
      15     Unused (0)

Usually set to 1004h, which does select ExternalClk (32.73kHz or 47.61kHz, as selected in SNDEXCNT on ARM side; per 2x16bit stereo data).
Unknown how InternalClk works exactly. Increasing the "dividers" doesn't consistently increase FIFO transfer time; it seems as if the max time gets truncated somehow; maybe that's caused by InternalClk being ANDed with still running ExternalClk.
MMIO[8284h/82A4h+(0..1)*80h] - BTDMP Receive/Transmit Usually 0004h (R/W)

      0-2    Unknown (0..7) (R/W)                                        (R/W)
      3-4    Unused? (0)
      5-11   Unknown (0..7Fh) (R/W)                                      (R/W)
      12-15  Unused? (0)

Hmmmm, the write-ability of bit0-11 resembles the Period register...?
MMIO[8286h/82A6h+(0..1)*80h] - BTDMP Receive/Transmit Usually 0021h (R/W)

      0-1    Unknown (0..3) (R/W)                                        (R/W)
      2-4    Unused? (0)
      5      Unknown/writeonly? (read=0) (code writes 1 here)            (W?)
      6-15   Unused? (0)

MMIO[8288h/82A8h+(0..1)*80h] - BTDMP Receive/Transmit Usually 0000h'a (R/W)

      0-12   Unknown (0..1FFFh) (R/W) (initially=1FFFh on reset)
      13-15  Unused (0)

MMIO[828Ah/82AAh+(0..1)*80h] - BTDMP Receive/Transmit Usually 0000h'b (R/W)

      0-11   Unknown (0..0FFFh) (R/W)
      12-15  Unused (0)

MMIO[828Ch/82ACh+(0..1)*80h] - BTDMP Receive/Transmit Usually 0000h'c (R/W)

      0-13   Unknown (0..3FFFh) (R/W)
      14-15  Unused (0)

MMIO[828Eh/82AEh+(0..1)*80h] - BTDMP Receive/Transmit Usually unused'a (R/W)
MMIO[8290h/82B0h+(0..1)*80h] - BTDMP Receive/Transmit Usually unused'b (R/W)

      0-15   Unknown (0..FFFFh) (R/W)

Some of the above unknown stuff might be... volume, bias, sample.size, mono/stereo, dummy-value-when-fifo-empty, beep generator, filter/equalizer, sample rate interpolation, whatever...?
MMIO[829Eh/82BEh+(0..1)*80h] - BTDMP Receive/Transmit Enable (R/W)

      0-14   Unused (0)
      15     Enable Transfer  (0=Off, 1=On, allow Transfer+IRQ's)

     ________________________________ BTDMP FIFOs _________________________________

MMIO[82C0h/82C2h+(0..1)*80h] - BTDMP Receive/Transmit FIFO Status (R)

      0      usually 0
      1      If transfer ENABLED usually set, sometimes 0
      2      If transfer ENABLED usually set
      3      FIFO Full  (0=No, 1=Full, 16x16bit words)
      4      FIFO Empty (0=No, 1=Empty, 0x16bit words)
      5      If transfer ENABLED usually set
      6      usually 0
      7      For TX: gets set when FIFO contains ONE word?
      8-15   usually 0

MMIO[82C4h/82C6h+(0..1)*80h] - BTDMP Receive/Transmit FIFO Data (R) and (W)

      0-15      Signed 16bit audio sample.

FIFO size is 16x16bit. The data is stereo, ie. one needs to write 2x16bit for a full stereo sample (the write-order for left/right is still unknown).
Software seems to be directly writing to the FIFO (rather than using DMA). If DMA is also supported, that would probably require whatever special settings in the BTDMP and/or DMA registers (ie. so that the DMA knows when it needs to transfer new FIFO data).
MMIO[82C8h/82CAh+(0..1)*80h] - BTDMP Receive/Transmit FIFO Control (R/W)

      0-1    Unknown     (0..3=?)                                          (R/W)
      2      Flush FIFO  (0=No change, 1=Clear FIFO)                       (W)
      3-15   Unused (0)

DSi Teak CPU Registers

36bit/40bit Accumulators: a0,a1,b0,b1

      a0e:a0h:a0l (4:16:16 bits) = a0 (36bit)    ;TL2: 40bit (8:16:16)
      a1e:a1h:a1l (4:16:16 bits) = a1 (36bit)    ;TL2: 40bit (8:16:16)
      b0e:b0h:b0l (4:16:16 bits) = b0 (36bit)    ;TL2: 40bit (8:16:16)
      b1e:b1h:b1l (4:16:16 bits) = b1 (36bit)    ;TL2: 40bit (8:16:16)

4bit snippets (bit32-35) of a0/a1 can be found in status registers (st0,st1). On TL2, the whole upper 8bit (bit32-39) of a0/a1/b0/b1 can be additionally accessed via push/pop (a0e,a1e,b0e,b1e).
Teak General Registers: r0,r1,r2,r3,r4,r5,r6,r7

      r0     ;TL  ;16bit  ;\
      r1     ;TL  ;16bit  ;
      r2     ;TL  ;16bit  ; old TL1 registers
      r3     ;TL  ;16bit  ;
      r4     ;TL  ;16bit  ;
      r5     ;TL  ;16bit  ;/
      r6     ;TL2 ;16bit  ;<-- new TL2 register
      r7     ;TL  ;16bit  ;<-- aka rb (with optional immediate, MemR7Imm)

32bit Multiply Result and 16bit Muliply Parameters: p0,p1, and x0,y0,x1,y1

      x0     ;TL  ;16bit  ;-
      y0     ;TL  ;16bit  ;-
      x1     ;TL2 ;16bit  ;-
      y1     ;TL2 ;16bit  ;-
      p0     ;TL  ;33bit! ;\Px   ;TL2: 33bit p0e:p0 ?  ;TL1: 32bit?
      p1     ;TL2 ;33bit! ;/     ;TL2: 33bit p1e:p1 ?  ;TL1: N/A
      p0h    ;TL  ;16bit  ; ;<-- aka ph ;<-- called "p0" (aka "p") in "RegisterP0"

The "load ps" and "load ps01" opcodes allow to specify a multiply shifter, this is useful when dealing with signed/unsigned parameters:

      Unsigned = Unsigned * Unsigned       ;use shift 0
      Unsigned = Unsigned * Signed         ;use shift +1
      Unsigned = Signed * Signed           ;use shift +2
      Signed = Unsigned * Unsigned         ;use shift -1
      Signed = Unsigned * Signed           ;use shift 0
      Signed = Signed * Signed             ;use shift +1

TeakLite Misc

      pc     ;TL  ;18bit! ;-program counter (TL2: 18bit, TL1: 16bit)
      sp     ;TL  ;16bit  ;-stack pointer (decreasing on push/call)
      sv     ;TL  ;16bit  ;-shift value (negative=right) (for shift-by-register)
      mixp   ;TL  ;16bit  ;-related to min/max/mind/maxd
      lc     ;TL  ;16bit  ;-Loop Counter (of block repeat)
      repc   ;TL  ;16bit  ;-Repeat Counter (for "rep" opcode)
      dvm    ;TL  ;16bit  ;-Data Value Match (OCEM data breakpoints) (and for trap)

TeakLiteII Misc: vtr0,vtr1,prpage

      vtr0   ;TL2 16bit   ;\related to vtrshr,vtrmov,vtrclr
      vtr1   ;TL2 16bit   ;/(saved C/C1 carry flags for Viterby decoding)
      prpage ;TL2 4bit    ;-??? (bit0-3 used/dangerous, bit4-15 always 0)

vtr0,vtr1 are related to vtrshr,vtrmov,vtrclr opcodes (and multi-function opcodes with "vtrshr" suffix).
prpage isn't used by existing DSi code, setting the four write-able bits to nonzero seems to screw-up opcode fetching, causing code to crash (unless one of the next 1-2 prefetched opcodes restores prpage=0, which causes opcode fetching to recover; after skipping some following prefetched opcodes, until prpage=0 is applied). Maybe it's related to code access rights or waitstates... it doesn't seem to be related to upper 2bit of the 18bit program counter (prpage is zero even when executing code above address 0FFFFh).
Old Control/Status registers (TeakLite): st0,st1,st2,icr
New Control/Status registers (TeakLiteII): stt0,stt1,stt2,mod0,mod1,mod2,mod3
DSi Teak CPU Control/Status Registers
Address Config (TeakLiteII): ar0,ar1,arp0,arp1,arp2,arp3
Address Step/Modulo: cfgi,cfgj (and TL2 stepi0,stepj0)
DSi Teak CPU Address Config/Step/Modulo
User-defined registers (optional off-core): ext0,ext1,ext2,ext3
The four ext registers are intended for custom hardware extensions (where they could be used as I/O ports, with faster & more direct access than memory mapped I/O).

      ext0   ;TL  ;16bit
      ext1   ;TL  ;16bit
      ext2   ;TL  ;16bit
      ext3   ;TL  ;16bit

In the DSi, the four register do exist (they are fully read/write-able), but unknown if they do have any special functions - or if they are just general-purpose data registers (existing DSi software isn't using the ext registers, and hardware is solely accessed via memory mapped I/O).
Bitfields for Control/Status registers and cfgi/cfgj registers

      page   ;TL  ;8bit "load" st1.bit0-7   (page for MemImm8)    ;aka "lpg"
      ps     ;TL  ;2bit "load" st1.bit10-11 (product shifter for multiply?)
      ps01   ;TL2 ;4bit "load" mod0...?     (maybe separate "ps" for p0 and p1 ?)
      movpd  ;TL2 ;2bit "load" stt2.bit6-7  (page for reading DATA from ProgMem)
      modi   ;TL  ;9bit "load" cfgi.bit7-15 =imm9
      modj   ;TL  ;9bit "load" cfgj.bit7-15 =imm9
      stepi  ;TL  ;7bit "load" cfgi.bit0-6  =imm7
      stepj  ;TL  ;7bit "load" cfgj.bit0-6  =imm7

Shadow Registers
Some registers (or in case of st0-st2: fractions thereof) exist as "shadows"... related to "cntx", "swap", "banke" (and maybe "bankr"?) opcodes, and "reti/retid" opcodes with "context" suffix, and interrupts with context switching enabled.

      st0  bit0,2-11                        ;\control/status (cntx)
      st1  bit10-11 (and "swap": bit0-7)    ; (TL2: probably also SttMod)
      st2  bit0-7                           ;/
      a0 <--> b0    manualswap only?        ;\accumulators (swap)
      a1 <--> b1    autoswapped?            ;/
      r0 <--> r0b                           ;\
      r1 <--> r1b                           ;
      r4 <--> r4b                           ; BankFlags (banke)
      r7 <--> r7b     ;TL2                  ;
      cfgi <--> cfgib                       ;
      cfgj <--> cfgjb ;TL2                  ;/
      Ar,Arp <--> ?   ;TL2                  ;-? (bankr and/or cntx)

Registers b0/b1 can be used as normal opcode operands, the other shadow registers are used only when doing bank/cntx stuff.
Suffix codes: dmod,dmodi,dmodj,dmodij,context,eu,dbrv,ebrv,s,r
Non-register assembler keywords.

      dmod   ;TL  ;suffix ;\
      dmodi  ;TL2 ;suffix ;
      dmodj  ;TL2 ;suffix ;
      dmodij ;TL2 ;suffix ;/
      context;TL  ;suffix ;<-- (related to "cntx")
      eu     ;TL  ;suffix ;<-- (aka "Axheu", now "Axh,eu")
      dbrv   ;TL2 ;suffix ;\for "bitrev"
      ebrv   ;TL2 ;suffix ;/
      s      ;TL  ;suffix ;\param for "cntx" opcode  ;"s" also for opcode 88D1h
      r      ;TL  ;suffix ;/

Condition codes: true,eq,neq,gt,ge,lt,le,nn,c,v,e,l,nr,niu0,iu0,iu1
The 16 condition codes can be used for all opcodes with "Cond" operand, whereas "true" can be omitted (as it means always/non-conditional), the four conditions "gt,ge,lt,le" can be also used with "min/max/maxd/cbs" opcodes.
Old pre-TeakLiteII keyword names (renamed in TeakLiteII)

      TL:   x    y    p    ph   rb   lpg   a0heu   a1heu
      TL2:  x0   y0   p0   p0h  r7   page  a0h,eu  a1h,eu

DSi Teak CPU Control/Status Registers

There are two sets of Control/Status registers

      Old registers (for TeakLite):   st0/st1/st2, and icr
      New registers (for TeakLiteII): stt0/stt1/stt2, and mod0/mod1/mod2/mod3

The new registers do contain only a few new bits, apart from that they are basically same as the old registers (with the old bits rearranged to different locations in the new registers).
The old registers do still exist on TeakLiteII, so one could use either old or new registers (all reads/writes will be mirrored to both register sets).
However, there are a few cases where writing the old registers may smash bits in new registers (writing the old "limit" bit will change BOTH of the new "limit" bits, changing "ps" versus "ps01" may also involve strange effects, and... changing "a0e/a1e" bits seems to have "weird" effects on a0l/a0h/a1l/a1h, or maybe that's some "wanted" saturation effect?).
CPU Flags (for Cond opcodes)
CPU Flags are stored in st0 register (with mirrors in stt0/stt1). The flags can be used for conditional opcodes (with "Cond" operand). According to TeakLite datasheet, the flags are affected somewhat like this:

      ZMNVCEL- add, addh, addl, cmp, cmpu, sub, subh, subl, inc, dec, neg
      ZMNVCEL- maa, maasu, mac, macsu, macus, macuu, msu, sqra, rnd, pacr, movr
      ZMN-C--- or
      ZM--C--- addv, cmpv, subv, and
      ZMN--E-- clr, clrr, copy, divs, swap, not, xor
      ZMN--0L- lim
      ZMNVCELR norm
      ZMN-CE-- rol, ror
      ZMN-CE-- movs, movsi, shfc, shfi, shl, shl4, shr, shr4  ;for logical shift
      ZMNVCEL- movs, movsi, shfc, shfi, shl, shl4, shr, shr4  ;for arithmetic shift
      ZMN--E-- mov, movp, pop        ;when dst=ac,bc (whut?)         ;\
      xxxxxxxx mov, movp, pop        ;when dst=st0                   ; mov etc.
      ------L- mov, push             ;when src=aXL,aXH,bXL,bXH       ;
      -------- mov, movp, pop, push  ;when src/dst neither of above  ;/
      ZMN--E-- cntx s  ;store shadows (new flags for a1)             ;\cntx
      ZMNVCELR cntx r  ;restore shadows (old flags)                  ;/
      ZM------ set, rst, chng
      Z------- tst0, tst1, tstb
      -M------ max, maxd, min
      -------R modr
      -------- mpy, mpyi, mpysu, sqr, exp
      -------- banke, dint, eint, load, nop, bkrep, rep, break, trap, movd
      -------- br, brr, call, calla, callr, ret, retd, reti, retid, rets

Flags for new TL2 opcodes aren't officially documented; some might follow the above rules (eg. the new "r6" register should act as old "r0-r5"), but other new opcodes might do this or that.

     __________________________ Old registers (TeakLite) __________________________

st0 - Old TL1 Status/Control Register st0

      0     SAT  R/W Saturation Mode  (0=Off, 1=Saturate "Ax to data") ;mod0.0
      1     IE   R/W Interrupt Enable (0=Disable, 1=Enable) ;dint/eint ;mod3.7
      2     IM0  R/W Interrupt INT0 Mask (0=Disable, 1=Enable if IE=1) ;mod3.8
      3     IM1  R/W Interrupt INT1 Mask (0=Disable, 1=Enable if IE=1) ;mod3.9
      4     R    R/W Flag: rN is Zero   ;see Cond nr                   ;stt1.4
      5     L    R/W Flag: Limit        ;see Cond l      ;L=(LM or VL) ;stt0.0+1
      6     E    R/W Flag: Extension    ;see Cond e                    ;stt0.2
      7     C    R/W Flag: Carry        ;see Cond c                    ;stt0.3
      8     V    R/W Flag: Overflow     ;see Cond v                    ;stt0.4
      9     N    R/W Flag: Normalized   ;see Cond nn                   ;stt0.5
      10    M    R/W Flag: Minus        ;see Cond gt,ge,lt,le          ;stt0.6
      11    Z    R/W Flag: Zero         ;see Cond eq,neq,gt,le         ;stt0.7
      12-15 a0e  R/W Accumulator 0 Extension Bits                      ;a0.32-35

st1 - Old TL1 Status/Control Register st1

      0-7   PAGE R/W Data Memory Page (for MemImm8) (see "load page")  ;mod1.0-7
      8-9   -    -   Reserved (read: always set)                       ;-
      10-11 PS   R/W Product Shifter for P0 (see "load ps")(multiply?) ;mod0.10-11
                       (0=No Shift, 1=SHR1, 2=SHL1, 3=SHL2)
      12-15 a1e  R/W Accumulator 1 Extension Bits                      ;a1.32-35

st2 - Old TL1 Status/Control Register st2

      0-3   MDn  R/W Enable cfgi.modi modulo for R0..R3 (0=Off, 1=On)  ;mod2.0-3
      4-5   MDn  R/W Enable cfgj.modj modulo for R4..R5 (0=Off, 1=On)  ;mod2.4-5
      6     IM2  R/W Interrupt INT2 Mask (0=Disable, 1=Enable if IE=1) ;mod3.10
      7     S    R/W Shift Mode (0=Arithmetic, 1=Logic)                ;mod0.7
      8     OU0  R/W OUSER0 User Output Pin                            ;mod0.8
      9     OU1  R/W OUSER1 User Output Pin                            ;mod0.9
      10    IU0  R   IUSER0 User Input Pin (zero)  ;see Cond iu0,niu0  ;stt1.??
      11    IU1  R   IUSER1 User Input Pin (zero)  ;see Cond iu1       ;stt1.??
      12    -    -   Reserved (read: always set)                       ;-
      13    IP2  R   Interrupt Pending INT2 (0=No, 1=IRQ)              ;stt2.2
      14    IP0  R   Interrupt Pending INT0 (0=No, 1=IRQ)              ;stt2.0
      15    IP1  R   Interrupt Pending INT1 (0=No, 1=IRQ)              ;stt2.1

icr - Old TL1 Interrupt Context and Repeat Nesting

      0     NMIC R/W NMI Context switching enable  (0=Off, 1=On)       ;mod3.0
      1     IC0  R/W INT0 Context switching enable (0=Off, 1=On)       ;mod3.1
      2     IC1  R/W INT1 Context switching enable (0=Off, 1=On)       ;mod3.2
      3     IC2  R/W INT2 Context switching enable (0=Off, 1=On)       ;mod3.3
      4     LP   R   InLoop (when inside one or more "bkrep" loops)    ;stt2.15
      5-7   BCn  R   Block repeat nest. counter ;see "bkrep"           ;stt2.12-14
      8-15  -    -   Reserved (read: always set)                       ;-

     _________________________ New registers (TeakLiteII) _________________________

stt0 - New TL2 Status/Control Register stt0 (CPU Flags)

      0     LM   R/W Flag: Limit, set if saturation has/had occured    ;st0.5
      1     VL   R/W Flag: LatchedV, set if overflow has/had occurred  ;st0.5, too
      2     E    R/W Flag: Extension    ;see Cond e                    ;st0.6
      3     C    R/W Flag: Carry        ;see Cond c                    ;st0.7
      4     V    R/W Flag: Overflow     ;see Cond v                    ;st0.8
      5     N    R/W Flag: Normalized   ;see Cond nn                   ;st0.9
      6     M    R/W Flag: Minus        ;see Cond gt,ge,lt,le          ;st0.10
      7     Z    R/W Flag: Zero         ;see Cond eq,neq,gt,le         ;st0.11
      8-10  -    -   Unknown (reads as zero)
      11    C1   R/W Flag: Carry1 (2nd carry, for dual-operation opcodes)
      12-15 -    -   Unknown (reads as zero)

stt1 - New TL2 Status/Control Register stt1 (whatever)

      0-3   -    -   Unknown (reads as zero)
      4     R    R/W Flag: rN is Zero   ;see Cond nr                   ;st0.4
      5-13  -    -   Unknown (reads as zero)  (IU1 and IU0 should be here!)
      14    P0E  R/W Upper bit of 33bit P0 register  ;\shifted-in on        ;p0.32
      15    P1E  R/W Upper bit of 33bit P1 register  ;/arith right shifts   ;p1.32

Note: bit14/bit15 are automatically sign-expanded when moving data to p0/p0h/p1.
stt2 - New TL2 Status/Control Register stt2 (Interrupt/ProgBank/Bkrep)

      0     IP0  R   Interrupt Pending INT0 (0=No, 1=IRQ)              ;st2.14
      1     IP1  R   Interrupt Pending INT1 (0=No, 1=IRQ)              ;st2.15
      2     IP2  R   Interrupt Pending INT2 (0=No, 1=IRQ)              ;st2.13
      3     IPV  R   Interrupt Pending VINT                            ;-
      4-5   -    -   Unknown (reads as zero)                           ;-
      6-7  PCMhi R/W Program Memory Bank (for ProgMemRn/ProgMemAxl) ("load movpd")
      8-11  -    -   Unknown (reads as zero)                           ;-
      12-14 BCn  R   Block repeat nest. counter ;see "bkrep"           ;icr.5-7
      15    LP   R   InLoop (when inside one or more "bkrep" loops)    ;icr.4

mod0 - New TL2 Status/Control Register mod0 (Misc)

      0     SAT  R/W Saturation Mode (0=Off, 1=Saturate "Ax to data"?) ;st0.0
      1     SATA R/W Saturation Mode on store (0=Off, 1="(Ax op data) to Ax"?)
      2     ?    R   Unknown (reads as one)
      3     -    -   Unknown (reads as zero)
      4     -    -   Unknown (reads as zero)
      5-6   HWM  R/W Halfword Multiply    ... Modify y0 (and y1?)
                      0=read y0/y1 directly (full 16bit words)
                      1=Takes y0>>8 and y1>>8 (logic shift)
                      2=Takes y0&0xFF and y1&0xFF
                      3=Takes y0>>8 and y1&&0xFF
      7     S    R/W Shift Mode (0=Arithmetic, 1=Logic)                ;st2.7
      8     OU0  R/W OUSER0 User Output Pin                            ;st2.8
      9     OU1  R/W OUSER1 User Output Pin                            ;st2.9
      10-11 PS0  R/W Product Shifter for P0 (see "load ps")(multiply?) ;st1.10-11
      12    -    -   Unknown (reads as zero)
      13-14 PS1  R/W Product Shifter for P1 (see "load ps")(multiply?)
      15    -    -   Unknown (reads as zero)

mod1 - New TL2 Status/Control Register mod1 (Data Page)

      0-7   PAGE R/W Data Memory Page (for MemImm8) (see "load page")  ;st1.0-7
      8-11  -    -   Unknown (reads as zero)
      12   STP16 R/W banke opcode (0=exchange cfgi/cfgj, 1=cfgi/cfgj+stepi0/stepj0)
                      1=use stepi0/j0 instead of stepi/j for stepping Rn registers
      13    CMD  R/W Change Modulo mode (0=New TL2 style, 1=TL1 style)
      14    EPI  R/W Unknown (1=Set R3=0 after any "modr R3" or "access[R3]"?)
      15    EPJ  R/W Unknown (1=Set R7=0 after any "modr R7" or "access[R7]"?)

mod2 - New TL2 Status/Control Register mod2 (Modulo Enable)

      0-3   MDn  R/W Enable cfgi.modi modulo for R0..R3 (0=Off, 1=On)  ;st2.0-3
      4-5   MDn  R/W Enable cfgj.modj modulo for R4..R5 (0=Off, 1=On)  ;st2.4-5
      6-7   MDn  R/W Enable cfgj.modj modulo for R6..R7 (0=Off, 1=On) ;TL2 only
      8-11  BRn  R/W Step +s for R0..R3 (0=cfgi.stepi, 1=stepi0)
      12-15 BRn  R/W Step +s for R4..R7 (0=cfgj.stepi, 1=stepj0)

XXX... bit8-9 seem to mess up my code (that uses r0/r1, but only with +0 step).
"When BRn=1, memory access through Rn will use the bit-reversed value of Rn as the address. Note that this also implies that stepi0/j0 will be used, regardless of what STP16 says."
mod3 - New TL2 Status/Control Register mod3 (Interrupt Control)

      0     NMIC R/W NMI Context switching enable  (0=Off, 1=On)       ;icr.0
      1     IC0  R/W INT0 Context switching enable (0=Off, 1=On)       ;icr.1
      2     IC1  R/W INT1 Context switching enable (0=Off, 1=On)       ;icr.2
      3     IC2  R/W INT2 Context switching enable (0=Off, 1=On)       ;icr.3
      4     OU2  R/W Unknown (R/W)
      5     OU3  R/W Unknown (R/W)
      6     OU4  ?   ---DANGER BIT--- (1=hangs/crashes when set)
      7     IE   R/W Interrupt Enable (0=Disable, 1=Enable) ;dint/eint ;st0.1
      8     IM0  R/W Interrupt INT0 Mask (0=Disable, 1=Enable if IE=1) ;st0.2
      9     IM1  R/W Interrupt INT1 Mask (0=Disable, 1=Enable if IE=1) ;st0.3
      10    IM2  R/W Interrupt INT2 Mask (0=Disable, 1=Enable if IE=1) ;st2.6
      11    IMV  R/W Interrupt VINT Mask (0=Disable, 1=Enable if IE=1?)
      12    -    -   Unknown (reads as zero)
      13   CCNTA R/W Unknown (R/W)
      14    CPC  R/W Stack word order for PC on call/ret (0=Normal, 1=Reversed)
      15    CREP R/W Unknown (R/W)

Bit14=0: push lowword then push highword on call; pop highword then pop lowword on ret.

DSi Teak CPU Address Config/Step/Modulo

     _______________________________ Address Config _______________________________

These registers allow to reconfigure opcodes. For example, opcodes with operand MemR45 can normally use only R4/R5 operands; if desired that can be changed to anything else like R3/R0. The selection if Offset/Step operands can be changed in similar way.

      Unknown which settings affect which opcodes exactly.

The DSi Sound code is using a default configuration for most of its code, but it does also have some functions with alternate configurations.
ar0/ar1

      0-2   R/W PM1/PM3 Post Modify Step    (0..7 = +0,+1,-1,+s,+2,-2,+2,-2)
      3-4   R/W CS1/CS3 Offset              (0..3 = +0,+1,-1,-1)
      5-7   R/W PM0/PM2 Post Modify Step    (0..7 = +0,+1,-1,+s,+2,-2,+2,-2)
      8-9   R/W CS0/CS2 Offset              (0..3 = +0,+1,-1,-1)
      10-12 R/W RN1/RN3 Register            (0..7 = R0..R7)
      13-15 R/W RN0/RN2 Register            (0..7 = R0..R7)

arp0/arp1/arp2/arp3

      0-2   R/W PIn     Post Modify Step I  (0..7 = +0,+1,-1,+s,+2,-2,+2,-2)
      3-4   R/W CIn     Offset I            (0..3 = +0,+1,-1,-1)
      5-7   R/W PJn     Post Modify Step J  (0..7 = +0,+1,-1,+s,+2,-2,+2,-2)
      8-9   R/W CJn     Offset J            (0..3 = +0,+1,-1,-1)
      10-11 R/W RIn     Register I          (0..3 = R0..R3)
      12    -   -       Unused              (always zero)
      13-14 R/W RJn     Register J          (0..3 = R4..R7)
      15    -   -       Unused              (always zero)

     ________________________________ Step/Modulo ________________________________

cfgi - Step and Mod I (for R0..R3)
cfgj - Step and Mod J (for R4..R7)

      0-6   stepi/stepj  (7bit) (see "load stepi/stepj")  ;step "Rn+s" ?
      7-15  modi/modj    (9bit) (see "load modi/modj")

The modulos can be enabled in Control/Status registers. Some opcodes do also allow to disable modulos via "dmod" suffix.
On TL2, the above 7bit stepi/stepj can be optionally replaced by new 16bit stepi0/stepj0 registers (via flags in mod2 register).
stepi0 ;TL2 16bit
stepj0 ;TL2 16bit

      0-16  stepi0/stepj0

more steps, probably for "modr" with "+s0" (stepII2D2S0)
and for STP16 and BRn?

DSi TeakLite II Instruction Set Encoding

The opcodes are 16bits wide (some followed by an additional 16bit parameter word, namely those with "@16" operands). The encoding is very messy (fixed opcode bits randomly mixed/interleaved with variable parameter bits, and with new TL2 opcodes squeezed in formerly unused locations), making it pretty much impossible to decode that unpleasant stuff by software/logic.
The only reasonable decoding way is using a huge table with 65536 entries (which could be generated temporarily from the information in below table, using the Base number plus all variable bit combinations, for example, "6100h TL mov MemImm8@0, Ab@11" has variable bits in bit0-7 and bit11-12, so the opcode would be mapped at 6100h-61FFh, 6900h-69FFh, 7100h-71FFh, 7900h-79FFh).
TeakLite I (TL) and TeakLite II (TL2) Opcodes

      Base  Ver Opcode (with parameter bits located at @bitnumber and up)
      D4FBh TL  add  MemImm16@16, Ax@8
      A600h TL  add  MemImm8@0, Ax@8
      86C0h TL  add  Imm16@16, Ax@8
      C600h TL  add  Imm8u@0, Ax@8
      D4DBh TL  add  MemR7Imm16@16, Ax@8
      4600h TL  add  MemR7Imm7s@0, Ax@8
      8680h TL  add  MemRn@0, Ax@8 || Rn@0stepZIDS@3
      86A0h TL  add  RegisterP0@0, Ax@8
      D2DAh TL2 add  Ab@10, Bx@0
      5DF0h TL2 add  Bx@1, Ax@0
      9070h TL2 add  MemR01@8, sv, Abh@2 || sub MemR01@8offsZI@0, sv, Abl@2
                 || mov Abl@2, MemR45@8 || R01@8stepII2@0, R45@8stepII2@1
      5DB0h TL2 add  MemR04@1, sv, Abh@2 || sub MemR04@1offsZI@0, sv, Abl@2
                 || R04@1stepII2@0
      6F80h TL2 add  MemR45@2, MemR01@2, Abh@3
                 || add MemR45@2offsZI@1, MemR01@2offsZI@0, Abl@3
                 || R01@2stepII2@0, R45@2stepII2@1
      6FA0h TL2 add  MemR45@2, MemR01@2, Abh@3
                 || sub MemR45@2offsZI@1, MemR01@2offsZI@0, Abl@3
                 || R01@2stepII2@0, R45@2stepII2@1
      5E30h TL2 add  MemR45@8, sv, Abh@2 || sub MemR45@8offsZI@1, sv, Abl@2
                 || mov Abl@2, MemR01@8 || R01@8stepII2@0, R45@8stepII2@1
      5DC0h TL2 add  p0, p1, Ab@2
      D782h TL2 add  p1, Ax@0
      5DF8h TL2 add  Px@1, Bx@0
      D38Bh TL2 add  r6, Ax@4
      4590h TL2 add3 p0, p1, Ab@2
      4592h TL2 add3a p0, p1, Ab@2
      4593h TL2 add3aa p0, p1, Ab@2
      5DC1h TL2 adda p0, p1, Ab@2
      B200h TL  addh MemImm8@0, Ax@8
      9280h TL  addh MemRn@0, Ax@8 || Rn@0stepZIDS@3
      92A0h TL  addh Register@0, Ax@8
      9464h TL2 addh r6, Ax@0
      90E0h TL2 addhp MemR0425@2, Px@4, Ax@8 || R0425@2stepII2D2S@0 ;p=ProgMem? Px?
      B400h TL  addl MemImm8@0, Ax@8
      9480h TL  addl MemRn@0, Ax@8 || Rn@0stepZIDS@3
      94A0h TL  addl Register@0, Ax@8
      9466h TL2 addl r6, Ax@0
      906Ch TL2 addsub  p0, p1, Ab@0
      49C2h TL2 addsub  p1, p0, Ab@4
      916Ch TL2 addsuba p0, p1, Ab@0
      49C3h TL2 addsuba p1, p0, Ab@4
      E700h TL  addv Imm16@16, MemImm8@0
      86E0h TL  addv Imm16@16, MemRn@0 || Rn@0stepZIDS@3
      87E0h TL  addv Imm16@16, Register@0
      47BBh TL2 addv Imm16@16, r6
      D4F9h TL  and  MemImm16@16, Ax@8
      A200h TL  and  MemImm8@0, Ax@8
      82C0h TL  and  Imm16@16, Ax@8
      C200h TL  and  Imm8u@0, Ax@8
      D4D9h TL  and  MemR7Imm16@16, Ax@8
      4200h TL  and  MemR7Imm7s@0, Ax@8
      8280h TL  and  MemRn@0, Ax@8 || Rn@0stepZIDS@3
      82A0h TL  and  RegisterP0@0, Ax@8
      6770h TL2 and  Ab@2, Ab@0, Ax@12                ;TL2 only
      D389h TL2 and  r6, Ax@4
      4B80h TL  banke BankFlags6@0  ;{r0}{,r1}{,r4}{,cfgi}{,r7}{,cfgj}
      8CDFh TL2 bankr       ;without operand ?
      8CDCh TL2 bankr Ar@0
      8CD0h TL2 bankr Ar@2, Arp@0
      8CD8h TL2 bankr Arp@0
      5EB8h TL2 bitrev Rn@0
      D7E8h TL2 bitrev Rn@0, dbrv
      D7E0h TL2 bitrev Rn@0, ebrv
      5C00h TL  bkrep NoReverse, Imm8u@0, Address16@16
      5D00h TL  bkrep NoReverse, Register@0, Address18@16and5
      8FDCh TL2 bkrep NoReverse, r6, Address18@16and0
      DA9Ch TL2 bkreprst MemR0425@0
      5F48h TL2 bkreprst MemSp, Unused2@0
      DADCh TL2 bkrepsto MemR0425@0, Unused1@10
      9468h TL2 bkrepsto MemSp, Unused3@0
      4180h TL  br   Address18@16and4, Cond@0
      D3C0h TL  break               ;break
      5000h TL  brr  RelAddr7@4, Cond@0
      41C0h TL  call Address18@16and4, Cond@0
      D480h TL  calla Axl@8
      D381h TL2 calla Ax@4
      1000h TL  callr RelAddr7@4, Cond@0
      9068h TL2 cbs  Axh@0, Axh@not0, r0, ge
      9168h TL2 cbs  Axh@0, Axh@not0, r0, gt
      D49Eh TL2 cbs  Axh@8, Bxh@5, r0, ge
      D49Fh TL2 cbs  Axh@8, Bxh@5, r0, gt
      D5C0h TL2 cbs  MemR01@2, MemR45@2, ge || R01@2stepII2@0, R45@2stepII2@1
      D5C8h TL2 cbs  MemR01@2, MemR45@2, gt || R01@2stepII2@0, R45@2stepII2@1
      E500h TL  chng Imm16@16, MemImm8@0
      84E0h TL  chng Imm16@16, MemRn@0 || Rn@0stepZIDS@3
      85E0h TL  chng Imm16@16, Register@0
      47BAh TL2 chng Imm16@16, r6
      0038h TL2 chng Imm16@16, SttMod@0
      6760h TL  clr  Implied ConstZero, Ax@12, Cond@0  ;aX=0
      6F60h TL  clr  Implied ConstZero, Bx@12, Cond@0  ;bX=0
      8ED0h TL2 clr  Implied ConstZero, Ab@2, Ab@0
      5DFEh TL2 clrp p0
      5DFFh TL2 clrp p0, p1
      5DFDh TL2 clrp p1
      67C0h TL  clrr Implied Const8000h, Ax@12, Cond@0 ;aX=8000h
      6F70h TL2 clrr Implied Const8000h, Bx@12, Cond@0 ;bX=8000h
      8DD0h TL2 clrr Implied Const8000h, Ab@2, Ab@0
      D4FEh TL  cmp  MemImm16@16, Ax@8
      AC00h TL  cmp  MemImm8@0, Ax@8
      8CC0h TL  cmp  Imm16@16, Ax@8
      CC00h TL  cmp  Imm8u@0, Ax@8
      D4DEh TL  cmp  MemR7Imm16@16, Ax@8
      4C00h TL  cmp  MemR7Imm7s@0, Ax@8
      8C80h TL  cmp  MemRn@0, Ax@8 || Rn@0stepZIDS@3
      8CA0h TL  cmp  RegisterP0@0, Ax@8
      4D8Ch TL2 cmp  Ax@1, Bx@0
      D483h TL2 cmp  b0, b1
      D583h TL2 cmp  b1, b0
      DA9Ah TL2 cmp  Bx@10, Ax@0
      8B63h TL2 cmp  p1, Ax@4
      D38Eh TL2 cmp  r6, Ax@4
      BE00h TL  cmpu MemImm8@0, Ax@8
      9E80h TL  cmpu MemRn@0, Ax@8 || Rn@0stepZIDS@3
      9EA0h TL  cmpu Register@0, Ax@8
      8A63h TL2 cmpu r6, Ax@3
      ED00h TL  cmpv Imm16@16, MemImm8@0
      8CE0h TL  cmpv Imm16@16, MemRn@0 || Rn@0stepZIDS@3
      8DE0h TL  cmpv Imm16@16, Register@0
      47BEh TL2 cmpv Imm16@16, r6
      D390h TL  cntx r  ;restore shadows
      D380h TL  cntx s  ;store shadows
      67F0h TL  copy Implied Ax@not12,   Ax@12, Cond@0 ;aX=aY
      67E0h TL  dec  Implied Const1,     Ax@12, Cond@0 ;aX=aX-1
      43C0h TL  dint        ;IE=0, interrupt disable
      0E00h TL  divs MemImm8@0, Ax@8
      4380h TL  eint        ;IE=1, interrupt enable
      9460h TL  exp  Bx@0, Implied sv
      9060h TL  exp  Bx@0, Implied sv, Ax@8
      9C40h TL  exp  MemRn@0, Implied sv || Rn@0stepZIDS@3
      9840h TL  exp  MemRn@0, Implied sv, Ax@8 || Rn@0stepZIDS@3
      9040h TL  exp  RegisterP0@0, Implied sv, Ax@8
      9440h TL  exp  RegisterP0@0, Implied sv
      D7C1h TL2 exp  r6, Implied sv
      D382h TL2 exp  r6, Implied sv, Ax@4
      67D0h TL  inc  Implied Const1,     Ax@12, Cond@0 ;aX=aX+1
      49C0h TL  lim  a0     ;aka a0,a0
      49D0h TL  lim  a0, a1
      49F0h TL  lim  a1     ;aka a1,a1
      49E0h TL  lim  a1, a0
      4D80h TL  load Imm2u@0, ps               ;st1.bit11-10=imm2
      DB80h TL  load Imm7s@0, stepi            ;cfgi.LSB=imm7
      DF80h TL  load Imm7s@0, stepj            ;cfgj.LSB=imm7
      0400h TL  load Imm8u@0, page             ;st1.LSBs=imm8 ;aka "lpg"
      0200h TL  load Imm9u@0, modi             ;cfgi.MSB=imm9
      0A00h TL  load Imm9u@0, modj             ;cfgj.MSB=imm9
      D7D8h TL2 load Imm2u@1, movpd, Unused1@0 ;stt2.bit6.7 (page for ProgMem)
      0010h TL2 load Imm4u@0, ps01             ;mod0.bit10-11,13-14 and st1.10-11 ?
      D400h TL  maa  MemR45@2, MemR0123@0, Ax@11
                 || R0123@0stepZIDS@3, R45@2stepZIDS@5
      8400h TL  maa  MemRn@0, Imm16@16, Ax@11 || Rn@0stepZIDS@3
      8420h TL  maa  y0, MemRn@0, Ax@11 || Rn@0stepZIDS@3
      8440h TL  maa  y0, Register@0, Ax@11
      E400h TL  maa  y0, MemImm8@0, Ax@11
      5EA8h TL2 maa  y0, r6, Ax@0
      D700h TL  maasu MemR45@2, MemR0123@0, Ax@11
                 || R0123@0stepZIDS@3, R45@2stepZIDS@5
      8700h TL  maasu MemRn@0, Imm16@16, Ax@11 || Rn@0stepZIDS@3
      8720h TL  maasu y0, MemRn@0, Ax@11 || Rn@0stepZIDS@3
      8740h TL  maasu y0, Register@0, Ax@11
      5EAEh TL2 maasu y0, r6, Ax@0
      D200h TL  mac  MemR45@2, MemR0123@0, Ax@11
                 || R0123@0stepZIDS@3, R45@2stepZIDS@5
      8200h TL  mac  MemRn@0, Imm16@16, Ax@11 || Rn@0stepZIDS@3
      8220h TL  mac  y0, MemRn@0, Ax@11 || Rn@0stepZIDS@3
      8240h TL  mac  y0, Register@0, Ax@11
      E200h TL  mac  y0, MemImm8@0, Ax@11
      5EA4h TL2 mac  y0, r6, Ax@0
      4D84h TL2 mac  y0, x1, Ax@1, Unused1@0
      5E28h TL2 mac1 MemR45@2, MemR01@2, Ax@8 || R01@2stepII2@0, R45@2stepII2@1
      D600h TL  macsu MemR45@2, MemR0123@0, Ax@11
                 || R0123@0stepZIDS@3, R45@2stepZIDS@5
      8600h TL  macsu MemRn@0, Imm16@16, Ax@11 || Rn@0stepZIDS@3
      E600h TL  macsu y0, MemImm8@0, Ax@11
      8620h TL  macsu y0, MemRn@0, Ax@11 || Rn@0stepZIDS@3
      8640h TL  macsu y0, Register@0, Ax@11
      5EACh TL2 macsu y0, r6, Ax@0
      D300h TL  macus MemR45@2, MemR0123@0, Ax@11
                 || R0123@0stepZIDS@3, R45@2stepZIDS@5
      8300h TL  macus MemRn@0, Imm16@16, Ax@11 || Rn@0stepZIDS@3
      8320h TL  macus y0, MemRn@0, Ax@11 || Rn@0stepZIDS@3
      8340h TL  macus y0, Register@0, Ax@11
      5EA6h TL2 macus y0, r6, Ax@0
      D500h TL  macuu MemR45@2, MemR0123@0, Ax@11
                 || R0123@0stepZIDS@3, R45@2stepZIDS@5
      8500h TL  macuu MemRn@0, Imm16@16, Ax@11 || Rn@0stepZIDS@3
      8520h TL  macuu y0, MemRn@0, Ax@11 || Rn@0stepZIDS@3
      8540h TL  macuu y0, Register@0, Ax@11
      5EAAh TL2 macuu y0, r6, Ax@0
      8460h TL  max  NoReverse, Ax@8, Implied Ax@not8, Bogus MemR0, ge,
                 Implied mixp, Implied r0 || R0stepZIDS@3   ;when aY >= aX
      8660h TL  max  NoReverse, Ax@8, Implied Ax@not8, Bogus MemR0, gt,
                 Implied mixp, Implied r0 || R0stepZIDS@3   ;when aY > aX
      5E21h TL2 max  a0h, a1h || max a0l, a1l || vtrshr
      5F21h TL2 max  a1h, a0h || max a1l, a0l || vtrshr
      D784h TL2 max  Axh@1, Bxh@0 || max Axl@1, Bxl@0 || vtrshr
      4A40h TL2 max  Axh@3, Bxh@4 || max Axl@3, Bxl@4 || mov Axl@not3, MemR04@1
                 || vtrshr || R04@1stepII2@0
      4A44h TL2 max  Axh@3, Bxh@4 || max Axl@3, Bxl@4 || mov Axh@not3, MemR04@1
                 || vtrshr || R04@1stepII2@0
      45A0h TL2 max  Axh@4, Bxh@3 || max Axl@4, Bxl@3 || mov Axh@not4, MemR45@2
                 || mov Axl@not4, MemR01@2 || vtrshr
                 || R01@2stepII2@0, R45@2stepII2@1
      D590h TL2 max  Axh@6, Bxh@5 || max Axl@6, Bxl@5 || mov Axh@not6, MemR01@2
                 || mov Axl@not6, MemR45@2 || vtrshr
                 || R01@2stepII2@0, R45@2stepII2@1
      4A60h TL2 max  Bxh@4, Axh@3 || max Bxl@4, Axl@3 || mov Bxl@not4, MemR04@1
                 || vtrshr || R04@1stepII2@0
      4A64h TL2 max  Bxh@4, Axh@3 || max Bxl@4, Axl@3 || mov Bxh@not4, MemR04@1
                 || vtrshr || R04@1stepII2@0
      8060h TL  maxd NoReverse, Ax@8, MemR0, ge, Implied mixp, Implied r0
                 || R0stepZIDS@3   ;when (r0) >= aX
      8260h TL  maxd NoReverse, Ax@8, MemR0, gt, Implied mixp, Implied r0
                 || R0stepZIDS@3   ;when (r0) > aX
      8860h TL  min  NoReverse, Ax@8, Implied Ax@not8, Bogus MemR0, le,
                 Implied mixp, Implied r0 || R0stepZIDS@3   ;when aY <= aX
      8A60h TL  min  NoReverse, Ax@8, Implied Ax@not8, Bogus MemR0, lt,
                 Implied mixp, Implied r0 || R0stepZIDS@3   ;when aY < aX
      43C2h TL2 min  Axh@0, Axh@not0 || min Axl@0, Axl@not0 || vtrshr
      D2B8h TL2 min  Axh@11, Bxh@10 || min Axl@11, Bxl@10
                 || mov Axh@not11, MemR01@2 || mov Axl@not11, MemR45@2
                 || vtrshr || R01@2stepII2@0, R45@2stepII2@1
      4A00h TL2 min  Axh@3, Bxh@4 || min Axl@3, Bxl@4 || mov Axl@not3, MemR04@1
                 || vtrshr || R04@1stepII2@0
      4A04h TL2 min  Axh@3, Bxh@4 || min Axl@3, Bxl@4 || mov Axh@not3, MemR04@1
                 || vtrshr || R04@1stepII2@0
      45E0h TL2 min  Axh@4, Bxh@3 || min Axl@4, Bxl@3 || mov Axh@not4, MemR45@2
                 || mov Axl@not4, MemR01@2 || vtrshr
                 || R01@2stepII2@0, R45@2stepII2@1
      D4BAh TL2 min  Axh@8, Bxh@0 || min Axl@8, Bxl@0 || vtrshr
      4A20h TL2 min  Bxh@4, Axh@3 || min Bxl@4, Axl@3 || mov Bxl@not4, MemR04@1
                 || vtrshr || R04@1stepII2@0
      4A24h TL2 min  Bxh@4, Axh@3 || min Bxl@4, Axl@3 || mov Bxh@not4, MemR04@1
                 || vtrshr || R04@1stepII2@0
      47A0h TL2 mind NoReverse, Ax@3, MemR0, le, Implied mixp, Implied r0
                 || R0stepZIDS@0
      47A4h TL2 mind NoReverse, Ax@3, MemR0, lt, Implied mixp, Implied r0
                 || R0stepZIDS@0
      0080h TL  modr MemRn@0stepZIDS@3
      00A0h TL  modr MemRn@0stepZIDS@3, dmod  ;Disable modulo
      D294h TL2 modr MemR0123@10stepII2D2S0@0 || modr MemR4567@10stepII2D2S0@5
      0D80h TL2 modr MemR0123@5stepII2D2S0@1  || modr MemR4567@5stepII2D2S0@3, dmod
      0D81h TL2 modr MemR0123@5stepII2D2S0@1, dmod
                 || modr MemR4567@5stepII2D2S0@3, dmod
      8464h TL2 modr MemR0123@8stepII2D2S0@0, dmod || modr MemR4567@8stepII2D2S0@3
      5DA0h TL2 modr MemRn@0stepD2
      5DA8h TL2 modr MemRn@0stepD2, dmod
      4990h TL2 modr MemRn@0stepI2
      4998h TL2 modr MemRn@0stepI2, dmod
      D290h TL  mov  Ab@10, Ab@5
      D298h TL  mov  Abl@10, dvm
      D2D8h TL  mov  Abl@10, x0
      3000h TL  mov  Ablh@9, MemImm8@0
      D4BCh TL  mov  Axl@8, MemImm16@16
      D49Ch TL  mov  Axl@8, MemR7Imm16@16
      DC80h TL  mov  Axl@8, MemR7Imm7s@0
      D4B8h TL  mov  MemImm16@16, Ax@8
      6100h TL  mov  MemImm8@0, Ab@11
      6200h TL  mov  MemImm8@0, Ablh@10
      6500h TL  mov  MemImm8@0, Axh@12, eu   ;aka Axheu
      6000h TL  mov  MemImm8@0, R0123457y0@10
      6D00h TL  mov  MemImm8@0, sv
      D491h TL  mov  dvm, Ab@5
      D492h TL  mov  icr, Ab@5
      5E20h TL  mov  Imm16@16, Bx@8
      5E00h TL  mov  Imm16@16, Register@0
      4F80h TL  mov  Imm5u@0, icr    ;uh, but icr is 8bit wide (only 4bit are R/W)?
      2500h TL  mov  Imm8s@0, Axh@12         ;signed!
      2900h TL  mov  Imm8s@0, ext0
      2D00h TL  mov  Imm8s@0, ext1
      3900h TL  mov  Imm8s@0, ext2
      3D00h TL  mov  Imm8s@0, ext3
      2300h TL  mov  Imm8s@0, R0123457y0@10  ;signed!
      0500h TL  mov  Imm8s@0, sv
      2100h TL  mov  Imm8u@0, Axl@12         ;unsigned!
      D498h TL  mov  MemR7Imm16@16, Ax@8
      D880h TL  mov  MemR7Imm7s@0, Ax@8
      98C0h TL  mov  MemRn@0, Bx@8 || Rn@0stepZIDS@3
      1C00h TL  mov  MemRn@0, Register@5 || Rn@0stepZIDS@3
      47E0h TL  mov  MemSp, Register@0
      47C0h TL  mov  mixp, Register@0
      2000h TL  mov  R0123457y0@9, MemImm8@0
      4FC0h TL  mov  Register@0, icr
      5E80h TL  mov  Register@0, mixp
      1800h TL  mov  Register@5, MemRn@0 || Rn@0stepZIDS@3
      5EC0h TL  mov  RegisterP0@0, Bx@5
      5800h TL  mov  RegisterP0@0, Register@5
      D490h TL  mov  repc, Ab@5
      7D00h TL  mov  sv, MemImm8@0
      D493h TL  mov  x0, Ab@5
      D49Bh TL2 mov  a0h, stepi0
      D59Bh TL2 mov  a0h, stepj0
      4390h TL2 mov  a0h, MemR0425@2 || mov y0, MemR0425@2offsZIDZ@0
                 || R0425@2stepII2D2S@0
      43D0h TL2 mov  a1h, MemR0425@2 || mov y0, MemR0425@2offsZIDZ@0
                 || R0425@2stepII2D2S@0
      8FD4h TL2 mov  Ab@0, p0
      43A0h TL2 mov  Abh@3, MemR01@2 || mov Abl@3, MemR45@2
                 || R01@2stepII2@0, R45@2stepII2@1
      43E0h TL2 mov  Abh@3, MemR45@2 || mov Abl@3, MemR01@2
                 || R01@2stepII2@0, R45@2stepII2@1
      9D40h TL2 mov  Abh@4, MemR04@1 || mov Abh@2, MemR04@1offsZI@0
                 || R04@1stepII2@0
      9164h TL2 mov  Abl@0, prpage
      9064h TL2 mov  Abl@0, repc
      D394h TL2 mov  Abl@0, x1
      D384h TL2 mov  Abl@0, y1
      9540h TL2 mov  Abl@3, ArArp@0
      9C60h TL2 mov  Abl@3, SttMod@0
      9560h TL2 mov  ArArp@0, Abl@3
      D488h TL2 mov  ArArp@0, MemR04@8 || R04@8stepII2@5
      5F50h TL2 mov  ArArpSttMod@0, MemR7Imm16@16
      886Bh TL2 mov  Ax@8, pc
      8C60h TL2 mov  Axh@4, MemR4567@8 || mov MemR0123@8, Axh@4
                 || R0123@8stepII2D2S@0, R4567@8stepII2D2S@2
      4800h TL2 mov  Axh@6, MemR0123@4 || movr MemR4567@4, Axh@6
                 || R0123@4stepII2D2S@0, R4567@4stepII2D2S@2
      4900h TL2 mov  Axh@6, MemR0123@4 || mov  MemR4567@4, Axh@6
                 || R0123@4stepII2D2S@0, R4567@4stepII2D2S@2
      7F80h TL2 mov  Axh@6, MemR4567@4 || movr MemR0123@4, Axh@6
                 || R0123@4stepII2D2S@0, R4567@4stepII2D2S@2
      8863h TL2 mov  Bx@8, pc
      0008h TL2 mov  Imm16@16, ArArp@0
      0023h TL2 mov  Imm16@16, r6
      0001h TL2 mov  Imm16@16, repc
      8971h TL2 mov  Imm16@16, stepi0
      8979h TL2 mov  Imm16@16, stepj0
      0030h TL2 mov  Imm16@16, SttMod@0
      5DD0h TL2 mov  Imm4u@0, prpage
      80C4h TL2 mov  MemR01@9, Abh@10 || mov MemR45@9, Abl@10
                 || R01@9stepII2@0, R45@9stepII2@8
      D292h TL2 mov  MemR0425@10_MemR0425@10offsZIDZ@5, Px@0
                 || R0425@10stepII2D2S@5
      D7D4h TL2 mov  MemR04@1, repc || R04@1stepII2@0
      5F4Ch TL2 mov  MemR04@1, sv || sub3 MemR04@1, p0, p1, b0 || R04@1stepII2@0
      D4B4h TL2 mov  MemR04@1, sv || sub3rnd MemR04@1, p0, p1, b1 || R04@1stepII2@0
      DE9Ch TL2 mov  MemR04@1, sv || sub3rnd MemR04@1, p0, p1, b0 || R04@1stepII2@0
      4B40h TL2 mov  MemR04@3, sv || addsub    MemR04@3, p1, p0, Bx@0
                 || R04@3stepII2@2
      4B42h TL2 mov  MemR04@3, sv || addsubrnd MemR04@3, p1, p0, Bx@0
                 || R04@3stepII2@2
      8062h TL2 mov  MemR04@4, ArArp@8  || R04@4stepII2@3
      8063h TL2 mov  MemR04@4, SttMod@8 || R04@4stepII2@3
      9960h TL2 mov  MemR04@4, sv || addsub    MemR04@4, p1, p0, Bx@2
                 || R04@4stepD2S@3  ;<-- ordered p1, p0 here !
      99E0h TL2 mov  MemR04@4, sv || addsubrnd MemR04@4, p1, p0, Bx@2
                 || R04@4stepD2S@3  ;<-- ordered p1, p0 here !
      9860h TL2 mov  MemR04@4, sv || sub3      MemR04@4, p0, p1, Bx@2
                 || R04@4stepD2S@3
      98E0h TL2 mov  MemR04@4, sv || sub3rnd   MemR04@4, p0, p1, Bx@2
                 || R04@4stepD2S@3
      8873h TL2 mov  MemR04@8, sv || sub3 MemR04@8, p0, p1, b1 || R04@8stepII2@3
      D4C0h TL2 mov  MemR45@5, Abh@2 || mov MemR01@5, Abl@2
                 || R01@5stepII2@0, R45@5stepII2@1
      4D90h TL2 mov  MemR7Imm16@16, ArArpSttMod@0
      D2DCh TL2 mov  MemR7Imm16@16, repc, Unused2@0, Unused1@10
      1B20h TL2 mov  MemRn@0, r6 || Rn@0stepZIDS@3 ;override 1800h (mov a1,MemRn@0)
      D29Ch TL2 mov  MemSp, r6, Unused2@0, Unused1@10
      8A73h TL2 mov  mixp, Bx@3
      4381h TL2 mov  mixp, r6
      4382h TL2 mov  p0h, Bx@0
      D3C2h TL2 mov  p0h, r6
      4B60h TL2 mov  p0h, Register@0     ;<-- here "p0h" as source
      8FD8h TL2 mov  p1, Ab@0
      88D0h TL2 mov  Px@1, MemR0425@8_MemR0425@8offsZIDZ@2   || R0425@8stepII2D2S@2
      88D1h TL2 mov  Px@1, MemR0425@8_MemR0425@8offsZIDZ@2,s || R0425@8stepII2D2S@2
      D481h TL2 mov  r6, Bx@8
      1B00h TL2 mov  r6, MemRn@0 || Rn@0stepZIDS@3 ;override 1800h (mov a0,MemRn@0)
      43C1h TL2 mov  r6, mixp
      5F00h TL2 mov  r6, Register@0
      5F60h TL2 mov  Register@0, r6
      D2D9h TL2 mov  repc, Abl@10
      D7D0h TL2 mov  repc, MemR04@1 || R04@1stepII2@0
      D3C8h TL2 mov  repc, MemR7Imm16@16, Unused3@0
      D482h TL2 mov  stepi0, a0h
      D582h TL2 mov  stepj0, a0h
      D2F8h TL2 mov  SttMod@0, Abl@10
      49C1h TL2 mov  x1, Ab@4
      D299h TL2 mov  y1, Ab@10
      5EB0h TL2 mov  prpage, Abl@0
      49A0h TL2 mov  SttMod@0, MemR04@4 || R04@4stepII2@3
      4DC0h TL2 mova Ab@4, MemR0425@2_MemR0425@2offsZIDZ@0 || R0425@2stepII2D2S@0
      4BC0h TL2 mova MemR0425@2_MemR0425@2offsZIDZ@0, Ab@4 || R0425@2stepII2D2S@0
      5F80h TL  movd MemR0123@0,ProgMemR45@2 || R0123@0stepZIDS@3, R45@2stepZIDS@5
      0040h TL  movp ProgMemAxl@5, Register@0
      0D40h TL2 movp ProgMemAx@5, Register@0
      0600h TL  movp ProgMemRn@0, MemR0123@5 || R0123@5stepZIDS@7, Rn@0stepZIDS@3
      D499h TL2 movpdw ProgMemAx@8_ProgMemAx@8offsI, pc
      8864h TL  movr MemR0425@3, Abh@8 || R0425@3stepII2D2S@0   ;op*10000h+8000h
      9CE0h TL  movr MemRn@0, Ax@8 || Rn@0stepZIDS@3
      9CC0h TL  movr RegisterP0@0, Ax@8
      5DF4h TL2 movr Bx@1, Ax@0
      8961h TL2 movr r6, Ax@3
      6300h TL  movs Implied sv, MemImm8@0, Ab@11
      0180h TL  movs Implied sv, MemRn@0, Ab@5 || Rn@0stepZIDS@3
      0100h TL  movs Implied sv, RegisterP0@0, Ab@5
      5F42h TL2 movs Implied sv, r6, Ax@0
      4080h TL  movsi Implied Imm5s@0, R0123457y0@9, Ab@5, Bogus Imm5s@0
      D000h TL  mpy  MemR45@2, MemR0123@0 || R0123@0stepZIDS@3, R45@2stepZIDS@5
      8000h TL  mpy  MemRn@0, Imm16@16    || Rn@0stepZIDS@3
      8020h TL  mpy  y0, MemRn@0          || Rn@0stepZIDS@3
      8040h TL  mpy  y0, Register@0
      E000h TL  mpy  y0, MemImm8@0
      5EA0h TL2 mpy  y0, r6
      CB00h TL2 mpy  MemR45@5, MemR01@5 || mpysu MemR45@5offsZI@4, MemR01@5offsZI@3
                 || sub3   p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CB01h TL2 mpy  MemR45@5, MemR01@5 || mpyus MemR45@5offsZI@4, MemR01@5offsZI@3
                 || sub3   p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CB02h TL2 mpy  MemR45@5, MemR01@5 || mpysu MemR45@5offsZI@4, MemR01@5offsZI@3
                 || sub3a  p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CB03h TL2 mpy  MemR45@5, MemR01@5 || mpyus MemR45@5offsZI@4, MemR01@5offsZI@3
                 || sub3a  p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CB04h TL2 mpy  MemR45@5, MemR01@5 || mpysu MemR45@5offsZI@4, MemR01@5offsZI@3
                 || add3   p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CB05h TL2 mpy  MemR45@5, MemR01@5 || mpyus MemR45@5offsZI@4, MemR01@5offsZI@3
                 || add3   p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CB06h TL2 mpy  MemR45@5, MemR01@5 || mpysu MemR45@5offsZI@4, MemR01@5offsZI@3
                 || add3a  p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CB07h TL2 mpy  MemR45@5, MemR01@5 || mpyus MemR45@5offsZI@4, MemR01@5offsZI@3
                 || add3a  p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      D5E0h TL2 mpy  MemR04@1, x1 || mpy y1, x0 || sub3 p0, p1, Ax@3
                 || R04@1stepII2@0
      D5E4h TL2 mpy  MemR04@1, x1 || mpy y1, x0 || add3 p0, p1, Ax@3
                 || R04@1stepII2@0
      C800h TL2 mpy  MemR4567@4, MemR0123@4
                 || mpy MemR4567@4offsZIDZ@2, MemR0123@4offsZIDZ@0
                 || add3 p0, p1, Ab@6 || R0123@4stepII2D2S@0, R4567@4stepII2D2S@2
      C900h TL2 mpy  MemR4567@4, MemR0123@4
                 || mpy MemR4567@4offsZIDZ@2, MemR0123@4offsZIDZ@0
                 || sub3 p0, p1, Ab@6 || R0123@4stepII2D2S@0, R4567@4stepII2D2S@2
      80C2h TL2 mpy  MemR45@0, MemR01@0 || mpy MemR45@0offsZI@9, MemR01@0offsZI@8
                 || add3a p0, p1, Ab@10 || R01@0stepII2@8, R45@0stepII2@9
      49C8h TL2 mpy  MemR45@2, MemR01@2 || mpy MemR45@2offsZI@1, MemR01@2offsZI@0
                 || sub3a p0, p1, Ab@4 || R01@2stepII2@0, R45@2stepII2@1
      80C8h TL2 mpy  MemR45@2, MemR01@2 || mpy MemR45@2offsZI@1, MemR01@2offsZI@0
                 || addsub  p0, p1, Ab@10 || R01@2stepII2@0, R45@2stepII2@1
      81C8h TL2 mpy  MemR45@2, MemR01@2 || mpy MemR45@2offsZI@1, MemR01@2offsZI@0
                 || addsuba p0, p1, Ab@10 || R01@2stepII2@0, R45@2stepII2@1
      82C8h TL2 mpy  MemR45@2, MemR01@2 || mpy MemR45@2offsZI@1, MemR01@2offsZI@0
                 || add     p0, p1, Ab@10 || R01@2stepII2@0, R45@2stepII2@1
      83C8h TL2 mpy  MemR45@2, MemR01@2 || mpy MemR45@2offsZI@1, MemR01@2offsZI@0
                 || adda    p0, p1, Ab@10 || R01@2stepII2@0, R45@2stepII2@1
      00C0h TL2 mpy  MemR45@3, MemR01@3 || mpy MemR45@3offsZI@2, MemR01@3offsZI@1
                 || sub  p0, p1, Ab@4 || R01@3stepII2@1, R45@3stepII2@2
      00C1h TL2 mpy  MemR45@3, MemR01@3 || mpy MemR45@3offsZI@2, MemR01@3offsZI@1
                 || suba p0, p1, Ab@4 || R01@3stepII2@1, R45@3stepII2@2
      0D20h TL2 mpy  MemR45@3, MemR01@3 || mpyus MemR45@3offsZI@2, MemR01@3offsZI@1
                 || add3a p0, p1, Ax@0, dmodi || R01@3stepII2@1, R45@3stepII2@2
      0D30h TL2 mpy  MemR45@3, MemR01@3 || mpyus MemR45@3offsZI@2, MemR01@3offsZI@1
                 || add3a p0, p1, Ax@0, dmodj || R01@3stepII2@1, R45@3stepII2@2
      4B50h TL2 mpy  MemR45@3, MemR01@3 || mpyus MemR45@3offsZI@2, MemR01@3offsZI@1
                 || add3a p0, p1, Ax@0, dmodij || R01@3stepII2@1, R45@3stepII2@2
      D7A0h TL2 mpy  MemR45@3, MemR01@3 || mpy MemR45@3offsZI@2, MemR01@3offsZI@1
                 || add3    sv, p0, p1, Ax@4 || R01@3stepII2@1, R45@3stepII2@2
      D7A1h TL2 mpy  MemR45@3, MemR01@3 || mpy MemR45@3offsZI@2, MemR01@3offsZI@1
                 || add3rnd sv, p0, p1, Ax@4 || R01@3stepII2@1, R45@3stepII2@2
      9861h TL2 mpy  MemR45@4, MemR01@4 || mpy MemR45@4offsZI@3, MemR01@4offsZI@2
                 || add3  p0, p1, Ax@8, dmodj  || R01@4stepII2@2, R45@4stepII2@3
      9862h TL2 mpy  MemR45@4, MemR01@4 || mpy MemR45@4offsZI@3, MemR01@4offsZI@2
                 || add3  p0, p1, Ax@8, dmodi  || R01@4stepII2@2, R45@4stepII2@3
      9863h TL2 mpy  MemR45@4, MemR01@4 || mpy MemR45@4offsZI@3, MemR01@4offsZI@2
                 || add3  p0, p1, Ax@8, dmodij || R01@4stepII2@2, R45@4stepII2@3
      98E1h TL2 mpy  MemR45@4, MemR01@4 || mpy MemR45@4offsZI@3, MemR01@4offsZI@2
                 || add3a p0, p1, Ax@8, dmodj  || R01@4stepII2@2, R45@4stepII2@3
      98E2h TL2 mpy  MemR45@4, MemR01@4 || mpy MemR45@4offsZI@3, MemR01@4offsZI@2
                 || add3a p0, p1, Ax@8, dmodi  || R01@4stepII2@2, R45@4stepII2@3
      98E3h TL2 mpy  MemR45@4, MemR01@4 || mpy MemR45@4offsZI@3, MemR01@4offsZI@2
                 || add3a p0, p1, Ax@8, dmodij || R01@4stepII2@2, R45@4stepII2@3
      4DA0h TL2 mpy  y0, MemR04@3 || mpyus y1, MemR04@3offsZI@2
                 || sub3  p0, p1, Ax@4 || R04@3stepII2@2
      4DA1h TL2 mpy  y0, MemR04@3 || mpyus y1, MemR04@3offsZI@2
                 || sub3a p0, p1, Ax@4 || R04@3stepII2@2
      4DA2h TL2 mpy  y0, MemR04@3 || mpyus y1, MemR04@3offsZI@2
                 || add3  p0, p1, Ax@4 || R04@3stepII2@2
      4DA3h TL2 mpy  y0, MemR04@3 || mpyus y1, MemR04@3offsZI@2
                 || add3a p0, p1, Ax@4 || R04@3stepII2@2
      94E0h TL2 mpy  y0, MemR04@4 || mpy   y1, MemR04@4offsZI@3
                 || sub3  p0, p1, Ax@8 || R04@4stepII2@3
      94E2h TL2 mpy  y0, MemR04@4 || mpy   y1, MemR04@4offsZI@3
                 || sub3a p0, p1, Ax@8 || R04@4stepII2@3
      94E4h TL2 mpy  y0, MemR04@4 || mpy   y1, MemR04@4offsZI@3
                 || add3  p0, p1, Ax@8 || R04@4stepII2@3
      94E6h TL2 mpy  y0, MemR04@4 || mpy   y1, MemR04@4offsZI@3
                 || add3a p0, p1, Ax@8 || R04@4stepII2@3
      94E1h TL2 mpy  y0, MemR04@4 || mpysu y1, MemR04@4offsZI@3
                 || sub3  p0, p1, Ax@8 || R04@4stepII2@3
      94E3h TL2 mpy  y0, MemR04@4 || mpysu y1, MemR04@4offsZI@3
                 || sub3a p0, p1, Ax@8 || R04@4stepII2@3
      94E5h TL2 mpy  y0, MemR04@4 || mpysu y1, MemR04@4offsZI@3
                 || add3  p0, p1, Ax@8 || R04@4stepII2@3
      94E7h TL2 mpy  y0, MemR04@4 || mpysu y1, MemR04@4offsZI@3
                 || add3a p0, p1, Ax@8 || R04@4stepII2@3
      8862h TL2 mpy  y0, x1 || mpy   MemR04@4, x0 || sub3  p0, p1, Ax@8
                 || R04@4stepII2@3
      8A62h TL2 mpy  y0, x1 || mpy   MemR04@4, x0 || add3  p0, p1, Ax@8
                 || R04@4stepII2@3
      4D88h TL2 mpy  y0, x1 || mpy   y1, x0 || sub p0, p1, Ax@1
      5E24h TL2 mpy  y0, x1 || mpy   y1, x0 || add p0, p1, Ab@0
      8061h TL2 mpy  y0, x1 || mpy   y1, x0 || add3  p0, p1, Ab@8
      8071h TL2 mpy  y0, x1 || mpy   y1, x0 || add3a p0, p1, Ab@8
      8461h TL2 mpy  y0, x1 || mpy   y1, x0 || sub3  p0, p1, Ab@8
      8471h TL2 mpy  y0, x1 || mpy   y1, x0 || sub3a p0, p1, Ab@8
      D484h TL2 mpy  y0, x1 || mpy   y1, x0 || add3aa p0, p1, Ab@0
      D49Dh TL2 mpy  y0, x1 || mpy   y1, x0 || sub p0, p1, Bx@5
      D4A0h TL2 mpy  y0, x1 || mpy   y1, x0 || addsub p0, p1, Ab@0
      4FA0h TL2 mpy  y0, x1 || mpy y1, x0 || add3 p0, p1, Ab@3
                 || mov Axh@6, MemR04@1 || mov Bxh@2, MemR04@1offsZI@0
                 || R04@1stepII2@0
      5818h TL2 mpy  y0, x1 || mpy y1, x0 || addsub    sv, p0, p1, Ax@0
                 || mov Axh@0, MemR0425@7 || mov Axh@not0, MemR0425@7offsZI@6
                 || R0425@7stepII2@6  ;override 5800h+18h (mov a0, Register)
      5838h TL2 mpy  y0, x1 || mpy y1, x0 || addsubrnd sv, p0, p1, Ax@0
                 || mov Axh@0, MemR0425@7 || mov Axh@not0, MemR0425@7offsZI@6
                 || R0425@7stepII2@6  ;override 5800h+38h (mov a1, Register)
      80D0h TL2 mpy  y0, x1 || mpy y1, x0 || addsub    sv, p0, p1, Ax@10
                 || mov Axh@9, MemR04@3 || mov Bxh@8, MemR04@3offsZI@2
                 || R04@3stepII2@2
      80D1h TL2 mpy  y0, x1 || mpy y1, x0 || addsubrnd sv, p0, p1, Ax@10
                 || mov Axh@9, MemR04@3 || mov Bxh@8, MemR04@3offsZI@2
                 || R04@3stepII2@2
      80D2h TL2 mpy  y0, x1 || mpy y1, x0 || add3      sv, p0, p1, Ax@10
                 || mov Axh@9, MemR04@3 || mov Bxh@8, MemR04@3offsZI@2
                 || R04@3stepII2@2
      80D3h TL2 mpy  y0, x1 || mpy y1, x0 || add3rnd   sv, p0, p1, Ax@10
                 || mov Axh@9, MemR04@3 || mov Bxh@8, MemR04@3offsZI@2
                 || R04@3stepII2@2
      D3A0h TL2 mpy  y0, x1 || mpy y1, x0 || addsub p0, p1, Ab@3
                 || mov Axh@6, MemR04@1 || mov Bxh@2, MemR04@1offsZI@0
                 || R04@1stepII2@0
      4D89h TL2 mpy  y0, x1 || mpyus y1, x0 || sub p0, p1, Ax@1
      5F24h TL2 mpy  y0, x1 || mpyus y1, x0 || add p0, p1, Ab@0
      8069h TL2 mpy  y0, x1 || mpyus y1, x0 || add3  p0, p1, Ab@8
      8079h TL2 mpy  y0, x1 || mpyus y1, x0 || add3a p0, p1, Ab@8
      8469h TL2 mpy  y0, x1 || mpyus y1, x0 || sub3  p0, p1, Ab@8
      8479h TL2 mpy  y0, x1 || mpyus y1, x0 || sub3a p0, p1, Ab@8
      D584h TL2 mpy  y0, x1 || mpyus y1, x0 || add3aa p0, p1, Ab@0
      D59Dh TL2 mpy  y0, x1 || mpyus y1, x0 || sub p0, p1, Bx@5
      D5A0h TL2 mpy  y0, x1 || mpyus y1, x0 || addsub p0, p1, Ab@0
      0800h TL  mpyi NoReverse, Implied p0, y0, Imm8s@0   ;multiply  ;aka "mpys"
      D100h TL  mpysu MemR45@2, MemR0123@0 || R0123@0stepZIDS@3, R45@2stepZIDS@5
      8100h TL  mpysu MemRn@0, Imm16@16    || Rn@0stepZIDS@3
      8120h TL  mpysu y0, MemRn@0          || Rn@0stepZIDS@3
      8140h TL  mpysu y0, Register@0
      CA00h TL2 mpysu MemR45@5, MemR01@5
                 || mpysu MemR45@5offsZI@4, MemR01@5offsZI@3
                 || sub3a  p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CA01h TL2 mpysu MemR45@5, MemR01@5
                 || mpyus MemR45@5offsZI@4, MemR01@5offsZI@3
                 || sub3a  p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CA02h TL2 mpysu MemR45@5, MemR01@5
                 || mpysu MemR45@5offsZI@4, MemR01@5offsZI@3
                 || sub3aa p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CA03h TL2 mpysu MemR45@5, MemR01@5
                 || mpyus MemR45@5offsZI@4, MemR01@5offsZI@3
                 || sub3aa p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CA04h TL2 mpysu MemR45@5, MemR01@5
                 || mpysu MemR45@5offsZI@4, MemR01@5offsZI@3
                 || add3a  p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CA05h TL2 mpysu MemR45@5, MemR01@5
                 || mpyus MemR45@5offsZI@4, MemR01@5offsZI@3
                 || add3a  p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CA06h TL2 mpysu MemR45@5, MemR01@5
                 || mpysu MemR45@5offsZI@4, MemR01@5offsZI@3
                 || add3aa p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      CA07h TL2 mpysu MemR45@5, MemR01@5
                 || mpyus MemR45@5offsZI@4, MemR01@5offsZI@3
                 || add3aa p0, p1, Ab@6 || R01@5stepII2@3, R45@5stepII2@4
      5EA2h TL2 mpysu y0, r6
      D080h TL  msu  MemR45@2,MemR0123@0,Ax@8 || R0123@0stepZIDS@3, R45@2stepZIDS@5
      90C0h TL  msu  MemRn@0, Imm16@16,  Ax@8 || Rn@0stepZIDS@3 ;multiply, subtract
      9080h TL  msu  y0, MemRn@0, Ax@8 || Rn@0stepZIDS@3
      90A0h TL  msu  y0, Register@0, Ax@8
      B000h TL  msu  y0,MemImm8@0, Ax@8
      9462h TL2 msu  y0, r6, Ax@0
      8264h TL2 msusu y0, MemR0425@3, Ax@8 || R0425@3stepII2D2S@0
      6790h TL  neg  Ax@12, Cond@0 ;aX=0-aX
      0000h TL  nop
      94C0h TL  norm Ax@8, Bogus MemRn@0 || Rn@0stepZIDS@3  ;if N=0 (aX=aX*2,rN+/-)
      6780h TL  not  Ax@12, Cond@0 ;aX=not aX
      D4F8h TL  or   MemImm16@16, Ax@8
      A000h TL  or   MemImm8@0, Ax@8
      80C0h TL  or   Imm16@16, Ax@8
      C000h TL  or   Imm8u@0, Ax@8
      D4D8h TL  or   MemR7Imm16@16, Ax@8
      4000h TL  or   MemR7Imm7s@0, Ax@8
      8080h TL  or   MemRn@0, Ax@8 || Rn@0stepZIDS@3
      80A0h TL  or   RegisterP0@0, Ax@8
      D291h TL2 or   Ab@10, Ax@6, Ax@5
      D4A4h TL2 or   Ax@8, Bx@1, Ax@0
      D3C4h TL2 or   b0, Bx@1, Ax@0
      D7C4h TL2 or   b1, Bx@1, Ax@0
      D388h TL2 or   r6, Ax@4
      67B0h TL  pacr Implied Const8000h, Implied p0, Ax@12, Cond@0 ;aX=shfP+8000h
      D7C2h TL2 pacr1 Implied Const8000h, Implied p1, Ax@0
      5E60h TL  pop  Register@0
      47B4h TL2 pop  Abe@0
      80C7h TL2 pop  ArArpSttMod@8
      0006h TL2 pop  Bx@5, Unused1@0
      D7F4h TL2 pop  prpage, Unused2@0
      D496h TL2 pop  Px@0
      0024h TL2 pop  r6, Unused1@0
      D7F0h TL2 pop  repc, Unused2@0
      D494h TL2 pop  x0
      D495h TL2 pop  x1
      0004h TL2 pop  y1, Unused1@0
      47B0h TL2 popa Ab@0
      5F40h TL  push Imm16@16
      5E40h TL  push Register@0
      D7C8h TL2 push Abe@1, Unused1@0
      D3D0h TL2 push ArArpSttMod@0
      D7FCh TL2 push prpage, Unused2@0
      D78Ch TL2 push Px@1, Unused1@0
      D4D7h TL2 push r6, Unused1@5
      D7F8h TL2 push repc, Unused2@0
      D4D4h TL2 push x0, Unused1@5
      D4D5h TL2 push x1, Unused1@5
      D4D6h TL2 push y1, Unused1@5
      4384h TL2 pusha Ax@6, Unused2@0
      D788h TL2 pusha Bx@1, Unused1@0
      0C00h TL  rep  Imm8u@0    ;repeat next opcode N+1 times
      0D00h TL  rep  Register@0 ;repeat next opcode N+1 times
      0002h TL2 rep  r6, Unused1@0
      4580h TL  ret  Cond@0      ;=pop pc
      D780h TL  retd    ;delayed return (after 2 clks)
      45C0h TL  reti Cond@0          ;Don't context switch
      45D0h TL  reti Cond@0, context ;Do context switch
      D7C0h TL  retid   ;delayed, from interrupt
      D3C3h TL2 retid context
      0900h TL  rets Imm8u@0          ;ret+dealloc sp (for INCOMING pushed params)
      67A0h TL  rnd  Implied Const8000h, Ax@12, Cond@0 ;aX=aX+8000h
      6750h TL  rol  Implied Const1,     Ax@12, Cond@0 ;aX=aX rcl 1 (37bit rotate)
      6F50h TL  rol  Implied Const1,     Bx@12, Cond@0 ;bX=bX rcl 1 (37bit rotate)
      6740h TL  ror  Implied Const1,     Ax@12, Cond@0 ;aX=aX rcr 1 (37bit rotate)
      6F40h TL  ror  Implied Const1,     Bx@12, Cond@0 ;bX=bX rcr 1 (37bit rotate)
      E300h TL  rst  Imm16@16, MemImm8@0
      82E0h TL  rst  Imm16@16, MemRn@0 || Rn@0stepZIDS@3
      83E0h TL  rst  Imm16@16, Register@0
      47B9h TL2 rst  Imm16@16, r6
      4388h TL2 rst  Imm16@16, SttMod@0
      E100h TL  set  Imm16@16, MemImm8@0
      80E0h TL  set  Imm16@16, MemRn@0 || Rn@0stepZIDS@3
      81E0h TL  set  Imm16@16, Register@0
      47B8h TL2 set  Imm16@16, r6
      43C8h TL2 set  Imm16@16, SttMod@0
      D280h TL  shfc Implied sv, Ab@10, Ab@5, Cond@0
      9240h TL  shfi Implied Imm6s@0, Ab@10, Ab@7, Bogus Imm6s@0
      6720h TL  shl  Implied Const1,     Ax@12, Cond@0 ;aX=aX*2
      6F20h TL  shl  Implied Const1,     Bx@12, Cond@0 ;bX=bX*2
      6730h TL  shl4 Implied Const4,     Ax@12, Cond@0 ;aX=aX*10h
      6F30h TL  shl4 Implied Const4,     Bx@12, Cond@0 ;bX=bX*10h
      6700h TL  shr  Implied Const1,     Ax@12, Cond@0 ;aX=aX/2
      6F00h TL  shr  Implied Const1,     Bx@12, Cond@0 ;bX=bX/2
      6710h TL  shr4 Implied Const4,     Ax@12, Cond@0 ;aX=aX/10h
      6F10h TL  shr4 Implied Const4,     Bx@12, Cond@0 ;bX=bX/10h
      BA00h TL  sqr  MemImm8@0
      9A80h TL  sqr  MemRn@0 || Rn@0stepZIDS@3
      9AA0h TL  sqr  Register@0
      D790h TL2 sqr  Abh@2 || sqr Abl@2 || add3 p0, p1, Ab@0
      49C4h TL2 sqr  Abh@4 || mpysu Abh@4, Abl@4 || add3a p0, p1, Ab@0
      4B00h TL2 sqr  MemR0425@4 || sqr MemR0425@4offsZIDZ@2 || add3 p0, p1, Ab@0
                 || R0425@4stepII2D2S@2
      5F41h TL2 sqr  r6
      BC00h TL  sqra MemImm8@0, Ax@8
      9C80h TL  sqra MemRn@0, Ax@8 || Rn@0stepZIDS@3
      9CA0h TL  sqra Register@0, Ax@8
      9062h TL2 sqra r6, Ax@8, Unused1@0
      D4FFh TL  sub  MemImm16@16, Ax@8
      AE00h TL  sub  MemImm8@0, Ax@8
      8EC0h TL  sub  Imm16@16, Ax@8
      CE00h TL  sub  Imm8u@0, Ax@8
      D4DFh TL  sub  MemR7Imm16@16, Ax@8
      4E00h TL  sub  MemR7Imm7s@0, Ax@8
      8E80h TL  sub  MemRn@0, Ax@8 || Rn@0stepZIDS@3
      8EA0h TL  sub  RegisterP0@0, Ax@8
      8A61h TL2 sub  Ab@3, Bx@8
      8861h TL2 sub  Bx@4, Ax@3
      8064h TL2 sub  MemR01@8, sv, Abh@3 || add MemR01@8offsZI@0, sv, Abl@3
                 || mov MemR45@8, sv || R01@8stepII2@0, R45@8stepII2@1
      5DE0h TL2 sub  MemR04@1, sv, Abh@2 || add MemR04@1offsZI@0, sv, Abl@2
                 || R04@1stepII2@0
      6FC0h TL2 sub  MemR45@2, MemR01@2, Abh@3
                 || add MemR45@2offsZI@1, MemR01@2offsZI@0, Abl@3
                 || R01@2stepII2@0, R45@2stepII2@1
      6FE0h TL2 sub  MemR45@2, MemR01@2, Abh@3
                 || sub MemR45@2offsZI@1, MemR01@2offsZI@0, Abl@3
                 || R01@2stepII2@0, R45@2stepII2@1
      5D80h TL2 sub  MemR45@2, sv, Abh@3 || add MemR45@2offsZI@1, sv, Abl@3
                 || mov MemR01@2, sv || R01@2stepII2@0, R45@2stepII2@1
      5DC2h TL2 sub  p0, p1, Ab@2
      D4B9h TL2 sub  p1, Ax@8
      8FD0h TL2 sub  Px@1, Bx@0
      D38Fh TL2 sub  r6, Ax@4
      80C6h TL2 sub3 p0, p1, Ab@10
      82C6h TL2 sub3a p0, p1, Ab@10
      83C6h TL2 sub3aa p0, p1, Ab@10
      5DC3h TL2 suba p0, p1, Ab@2
      B600h TL  subh MemImm8@0, Ax@8
      9680h TL  subh MemRn@0, Ax@8 || Rn@0stepZIDS@3
      96A0h TL  subh Register@0, Ax@8
      5E23h TL2 subh r6, Ax@8
      B800h TL  subl MemImm8@0, Ax@8
      9880h TL  subl MemRn@0, Ax@8 || Rn@0stepZIDS@3
      98A0h TL  subl Register@0, Ax@8
      5E22h TL2 subl r6, Ax@8
      EF00h TL  subv Imm16@16, MemImm8@0
      8EE0h TL  subv Imm16@16, MemRn@0 || Rn@0stepZIDS@3
      8FE0h TL  subv Imm16@16, Register@0
      47BFh TL2 subv Imm16@16, r6
      4980h TL  swap SwapTypes4@0
      0020h TL  trap                  ;software interrupt
      A800h TL  tst0 Axl@8, MemImm8@0
      8880h TL  tst0 Axl@8, MemRn@0 || Rn@0stepZIDS@3
      88A0h TL  tst0 Axl@8, Register@0
      E900h TL  tst0 Imm16@16, MemImm8@0
      88E0h TL  tst0 Imm16@16, MemRn@0 || Rn@0stepZIDS@3
      89E0h TL  tst0 Imm16@16, Register@0
      D38Ch TL2 tst0 Axl@4, r6
      47BCh TL2 tst0 Imm16@16, r6
      9470h TL2 tst0 Imm16@16, SttMod@0
      AA00h TL  tst1 Axl@8, MemImm8@0 Implied Not
      8A80h TL  tst1 Axl@8, MemRn@0 Implied Not || Rn@0stepZIDS@3
      8AA0h TL  tst1 Axl@8, Register@0 Implied Not
      EB00h TL  tst1 Imm16@16, MemImm8@0 Implied Not
      8AE0h TL  tst1 Imm16@16, MemRn@0 Implied Not || Rn@0stepZIDS@3
      8BE0h TL  tst1 Imm16@16, Register@0 Implied Not
      D38Dh TL2 tst1 Axl@4, r6 Implied Not
      47BDh TL2 tst1 Imm16@16, r6 Implied Not
      9478h TL2 tst1 Imm16@16, SttMod@0 Implied Not
      80C1h TL2 tst4b a0l, MemR0425@10 || R0425@10stepII2D2S@8
      4780h TL2 tst4b a0l, MemR0425@2, Ax@4 || R0425@2stepII2D2S@0
      F000h TL  tstb NoReverse, Implied Not MemImm8@0, Imm4bitno@8
      9020h TL  tstb NoReverse, Implied Not MemRn@0, Imm4bitno@8 || Rn@0stepZIDS@3
      9000h TL  tstb NoReverse, Implied Not Register@0, Imm4bitno@8
      9018h TL2 tstb NoReverse, Implied Not r6, Imm4bitno@8  ;override tstb a0,Imm4
      0028h TL2 tstb NoReverse, Implied Not SttMod@0, Imm4bitno@16, Unused12@20
      5F45h TL2 vtrclr vtr0         ;vtr0=0           ;for Viterbi decoding...
      5F47h TL2 vtrclr vtr0, vtr1   ;vtr0=0, vtr1=0   ;(saved C/C1 carry flags)
      5F46h TL2 vtrclr vtr1         ;vtr1=0
      D383h TL2 vtrmov Axl@4        ;Axl=(vtr1 and FF00h)+(vtr0/100h)
      D29Ah TL2 vtrmov vtr0, Axl@0  ;Axl=vtr0
      D69Ah TL2 vtrmov vtr1, Axl@0  ;Axl=vtr1
      D781h TL2 vtrshr              ;vtr0=vtr0/2+C*8000h, vtr1=vtr1/2+C1*8000h
      D4FAh TL  xor  MemImm16@16, Ax@8
      A400h TL  xor  MemImm8@0, Ax@8
      84C0h TL  xor  Imm16@16, Ax@8
      C400h TL  xor  Imm8u@0, Ax@8
      D4DAh TL  xor  MemR7Imm16@16, Ax@8
      4400h TL  xor  MemR7Imm7s@0, Ax@8
      8480h TL  xor  MemRn@0, Ax@8 || Rn@0stepZIDS@3
      84A0h TL  xor  RegisterP0@0, Ax@8
      D38Ah TL2 xor  r6, Ax@4
      8800h TL  undefined Unused5@0, Unused1@8 ;(mpy/mpys without A in bit11)
      8820h TL  undefined Unused5@0, Unused1@8 ;(mpy/mpys without A in bit11)
      8840h TL  undefined Unused5@0, Unused1@8 ;(mpy/mpys without A in bit11)
      D800h TL  undefined Unused7@0, Unused1@8 ;(mpy/mpys without A in bit11)
      9B80h TL  undefined Unused6@0  ;(sqr without A in bit8)
      BB00h TL  undefined Unused8@0  ;(sqr without A in bit8)
      E800h TL  undefined Unused8@0  ;(mpy without A in bit11)
      5EA1h TL2 undefined Unused1@1  ;(mpy/mpys without A in bit11)
      5DFCh TL2 undefined
      8CDEh TL2 undefined
      D3C1h TL2 undefined
      5EB4h TL2 undefined Unused2@0

DSi TeakLite II Operand Encoding

Syntax Notes
The official Teak syntax specifies all operands in "source,dest" order, that's opposite of most other ASM languages which use "dest,source" order (except 68000 processors, which the Teak is apparently inspired on). One exception are instructions tagged "NoReverse" in the opcode list: These ones do have the operands ordered as how one would usually expect them.
Operands tagged as "Implied xx" are effectively used by the hardware, although the official syntax doesn't specify them in source code. On the other hand, operands tagged as "Bogus xx" are specified in official source code syntax, although the hardware doesn't actually use that operands in that form.
The nocash (dis-)assembler syntax reverses the operand order (except those flagged as NoReverse), removes Bogus operands, and inserts Implied operands. Moreover, immediates and memory operands are specified differently...
Memory Operands

      name          native                  nocash
      MemRn         (Rn)                    [Rn]
      MemSp         (sp)                    [sp]
      ProgMemRn     (Rn)                    [code:movpd:Rn]
      ProgMemAxl    (Axl)                   [code:movpd:Axl]
      ProgMemAx     (Ax)                    [code:Ax]
      ProgMemAx_..  (Ax),(Ax+)              [code:Ax]:[code:Ax+]
      MemImm8       0xNN                    [page:NNh]
      MemImm16      [##0xNNNN]              [NNNNh]
      MemR7Imm7s    (r7+#0xNN), (r7+#-NNN)  [r7+/-NNh]
      MemR7Imm16    (r7+##0xNNNN)           [r7+NNNNh]

Immediates/Addresses

      Address18     0xNNNNN                 NNNNNh         ;for bkrep/br/call
      Address16     0xNNNN                  NNNNh          ;for bkrep
      RelAddr7      0xNNNN                  NNNNh          ;for jmp
      ImmN:         #0xNNNN                 NNNNh
      ImmNs:        #0xNN, #-NNN            +/-NNh
      Imm16:        ##0xNNNN                NNNNh
      Imm4bitno:    ...                     1 shl N
      ConstZero     <implied>               0000h
      Const1        <implied>               0001h
      Const4        <implied>               0004h
      Const8000h    <implied>               8000h

Operand Encoding
Below shows the binary encoding for registers/conditions. For example, "Ab@10" in the opcode list can be "b0,b1,a0,a1" encoded in bit10-11. Some instructions re-use the same bitfield for multiple operands (eg. when performing two operations on the SAME operand, or when expecting DIFFERENT operands: for "Ax@12,Ax@not12" one of the registers must "a0", and the other must be "a1").

      Register:  RegisterP0:  Ax:     Axl:    Axh:            Px:
      00: r0     00: r0       0: a0   0: a0l  0: a0h          0: p0
      01: r1     01: r1       1: a1   1: a1l  1: a1h          1: p1
      02: r2     02: r2
      03: r3     03: r3       Bx:     Bxl:    Bxh:            Ablh:
      04: r4     04: r4       0: b0   0: b0l  0: b0h          0: b0l
      05: r5     05: r5       1: b1   1: b1l  1: b1h          1: b0h
      06: r7     06: r7                                       2: b1l
      07: y0     07: y0       Ab:     Abl:    Abh:    Abe:    3: b1h
      08: st0    08: st0      0: b0   0: b0l  0: b0h  0: b0e  4: a0l
      09: st1    09: st1      1: b1   1: b1l  1: b1h  1: b1e  5: a0h
      0A: st2    0A: st2      2: a0   2: a0l  2: a0h  2: a0e  6: a1l
      0B: p0h !! 0B: p0 !!    3: a1   3: a1l  3: a1h  3: a1e  7: a1h
      0C: pc     0C: pc
      0D: sp     0D: sp       Cond:
      0E: cfgi   0E: cfgi     0: true  ;Always                    ;always
      0F: cfgj   0F: cfgj     1: eq    ;Equal to zero             ;Z=1
      10: b0h    10: b0h      2: neq   ;Not equal to zero         ;Z=0
      11: b1h    11: b1h      3: gt    ;Greater than zero         ;M=0 and Z=0
      12: b0l    12: b0l      4: ge    ;Greater or equal to zero  ;M=0
      13: b1l    13: b1l      5: lt    ;Less than zero            ;M=1
      14: ext0   14: ext0     6: le    ;Less or equal to zero     ;M=1 or Z=1
      15: ext1   15: ext1     7: nn    ;Normalize flag is cleared ;N=0
      16: ext2   16: ext2     8: c     ;Carry flag is set         ;C=1
      17: ext3   17: ext3     9: v     ;Overflow flag is set      ;V=1
      18: a0     18: a0       A: e     ;Extension flag is set     ;E=1
      19: a1     19: a1       B: l     ;Limit flag is set         ;L=1
      1A: a0l    1A: a0l      C: nr    ;R flag is cleared         ;R=0
      1B: a1l    1B: a1l      D: niu0  ;Input user pin 0 cleared  ;IUSER0=0
      1C: a0h    1C: a0h      E: iu0   ;Input user pin 0 set      ;IUSER0=1
      1D: a1h    1D: a1h      F: iu1   ;Input user pin 1 set      ;IUSER1=1
      1E: lc     1E: lc
      1F: sv     1F: sv

      R0123457y0:       Rn:                 ArArpSttMod:  ArArp:       SttMod:
      0: r0             0: r0               0: ar0        0: ar0       0: stt0
      1: r1             1: r1               1: ar1        1: ar1       1: stt1
      2: r2             2: r2               2: arp0       2: arp0      2: stt2
      3: r3             3: r3               3: arp1       3: arp1      3: reserved
      4: r4             4: r4               4: arp2       4: arp2      4: mod0
      5: r5             5: r5               5: arp3       5: arp3      5: mod1
      6: r7  ;aka rb    6: r6 ;TL2 only     6: reserved   6: reserved  6: mod2
      7: y0  ;aka y     7: r7 ;TL2 only     7: reserved   7: reserved  7: mod3
                                            8: stt0
      R01:     R04:     R45:                9: stt1       Ar:       BankFlags:
      0: r0    0: r0    0:r4                A: stt2       0: ar0    01h: cfgi
      1: r1    1: r4    1:r5                B: reserved   1: ar1    02h: r4
                                            C: mod0                 04h: r1
      R0123:   R0425:   R4567:              D: mod1       Arp:      08h: r0
      0: r0    0: r0    0: r4               E: mod2       0: arp0   10h: r7   ;TL2
      1: r1    1: r4    1: r5               F: mod3       1: arp1   20h: cfgj ;TL2
      2: r2    2: r2    2: r6                             2: arp2
      3: r3    3: r5    3: r7                             3: arp3

      SwapTypes:
      val native           nocash         ;meaning
      0:  (a0,b0)          a0,b0          ;a0 <--> b0                ;flags(a0)
      1:  (a0,b1)          a0,b1          ;a0 <--> b1                ;flags(a0)
      2:  (a1,b0)          a1,b0          ;a1 <--> b0                ;flags(a1)
      3:  (a1,b1)          a1,b1          ;a1 <--> b1                ;flags(a1)
      4:  (a0,b0),(a1,b1)  a0:a1,b0:b1    ;a0 <--> b0 and a1 <--> b1 ;flags(a0)
      5:  (a0,b1),(a1,b0)  a0:a1,b1:b0    ;a0 <--> b1 and a1 <--> b0 ;flags(a0)
      6:  (a0,b0,a1)       a1,b0,a0       ;a0 --> b0 --> a1          ;flags(a1)
      7:  (a0,b1,a1)       a1,b1,a0       ;a0 --> b1 --> a1          ;flags(a1)
      8:  (a1,b0,a0)       a0,b0,a1       ;a1 --> b0 --> a0          ;flags(a0)
      9:  (a1,b1,a0)       a0,b1,a1       ;a1 --> b1 --> a0          ;flags(a0)
      A:  (b0,a0,b1)       b1,a0,b0       ;b0 --> a0 --> b1          ;flags(a0)!
      B:  (b0,a1,b1)       b1,a1,b0       ;b0 --> a1 --> b1          ;flags(a1)!
      C:  (b1,a0,b0)       b0,a0,b1       ;b1 --> a0 --> b0          ;flags(a0)!
      D:  (b1,a1,b0)       b0,a1,b1       ;b1 --> a1 --> b0          ;flags(a1)!
      E:  reserved         reserved       ;-                         ;-
      F:  reserved         reserved       ;-                         ;-

offs and step
Memory operands with "offs" allow to read from [Rn], [Rn+1], or [Rn-1]. Operands with "step" allow to increment/decrement registers (for old TL opcodes this is usually specified alongsides with memory operands, for new TL2 opcodes it's typically specified as separate "||" instruction (eg. "|| Rn@0stepZIDS@3"; which can be omitted if the step is zero).
The official syntax wants "+1,-1" abbreviated to "+,-" in some cases (but not abbreviated in other cases). step "+s" does probably refer to "stepi or stepj", but it's rather unclear which one, maybe stepi is used for r0..r3, and stepj for r4..r7, or vice versa... or maybe it depends on each opcode (particulary opcodes that allow to use "Rn" (r0..r7) might use the same step in ALL cases).

     offsZI:                           ;maybe offsAr01 ?
      0: ''         ;Z  (zero)
      1: '+'        ;I  (increment)
     offsI:
      0: '+'        ;I  (increment)
     offsZIDZ:                         ;aka offsAr0123
      0: ''         ;Z  (zero)
      1: '+'        ;I  (increment)
      2: '-'        ;D  (decrement)
      3: ''         ;Z  (zero)
     stepZIDS:
      0: ''         ;Z  (zero)
      1: '+1'       ;I  (increment)
      2: '-1'       ;D  (decrement)
      3: '+s'       ;S  (add step)           ;XXX ?   see "stepi" and "stepj"
     modrstepZIDS:
      0: ''         ;Z  (zero)
      1: '+'        ;I  (increment)
      2: '-'        ;D  (decrement)
      3: '+s'       ;S  (add step)           ;XXX ?   see "stepi" and "stepj"
     stepII2D2S:                      ;aka stepAr0123@
      0: '+1'       ;I  (increment)
      1: '+2'       ;I2 (increment twice)
      2: '-2'       ;D2 (decrement twice)
      3: '+s'       ;S  (add step)           ;XXX ?   see "stepi" and "stepj"
     stepD2S:
      0: '-2'       ;D2 (decrement twice)
      1: '+s'     ' ;S  (add step)           ;XXX ?   see "stepi" and "stepj"
     modrstepII2D2S0:
      0: '+'        ;I  (increment)
      1: '+2'       ;I2 (increment twice)
      2: '-2'       ;D2 (decrement twice)
      3: '+s0'      ;S0 (add step0 ?)        ;XXX ??  see "stepi0" and "stepj0"
     stepII2:
      0: '+1'       ;I  (increment)
      1: '+2'       ;I2 (increment twice)
     modrstepI2:
      0: '+2'       ;I2 (increment twice)
     modrstepD2:
      0: '-2'       ;D2 (decrement twice)

Note: The "modr" opcodes are probably just incrementing/decrementing registers (with optional "modulo"), although the official syntax specifies their operands in brackets, ie. as if they were doing memory accesses.

DSi New Shared WRAM (for ARM7, ARM9, DSP)

Shared WRAM (total 800Kbytes)

      Old WRAM-0/1 32Kbytes (2x16K), mappable to ARM7, or ARM9
      New WRAM-A  256Kbytes (4x64K), mappable to ARM7, or ARM9
      New WRAM-B  256Kbytes (8x32K), mappable to ARM7, ARM9, or DSP-program memory
      New WRAM-C  256Kbytes (8x32K), mappable to ARM7, ARM9, or DSP-data memory

New WRAM mapping is done in three steps: First, releasing Slot Write Protect (on ARM7 side). Then, mapping the physical banks to logical slots (on ARM9 side). And finally, mapping those slots to actual memory addresses (on ARM7 and ARM9 sides). As an extra step, one may set Slot Write Protect flags (on ARM7 side) to prevent ARM9 from applying further changes.

     ____________________________ Slot Write Protect ______________________________

MBK9 is READ/WRITE-ABLE only on ARM7 side (and READ-ONLY on ARM7).
4004060h - DSi9 - MBK9, WRAM-A/B/C Slot Write Protect (undocumented) (R)
4004060h - DSi7 - MBK9, WRAM-A/B/C Slot Write Protect (undocumented) (R/W)

      0-3   WRAM-A, Port 4004040h-4004043h Write (0=Writeable by ARM9, 1=Read-only)
      4-7   Unknown/Unused (0)
      8-15  WRAM-B, Port 4004044h-400404Bh Write (0=Writeable by ARM9, 1=Read-only)
      16-23 WRAM-C, Port 400404Ch-4004053h Write (0=Writeable by ARM9, 1=Read-only)
      24-31 Unknown/Unused (0)   ;but, carthdr has nonzero data for it?

Selects whether ARM9 may write to WRAM slot registers at 4004040h-4004053h (in Read-only mode neither ARM7 nor ARM9 can write to those registers; that applies only to that registers, ie. the memory itself isn't write-protected).

     ______________________________ Slot Allocation ______________________________

MBK1-MBK5 are READ-ONLY on ARM7 side, and either READ-ONLY or READ/WRITE-ABLE on ARM9 side (depending on the MBK9 setting).
4004040h - DSi - MBK1.0, WRAM-A0 - 64K, mappable to ARM7, or ARM9
4004041h - DSi - MBK1.1, WRAM-A1 - 64K, mappable to ARM7, or ARM9
4004042h - DSi - MBK1.2, WRAM-A2 - 64K, mappable to ARM7, or ARM9
4004043h - DSi - MBK1.3, WRAM-A3 - 64K, mappable to ARM7, or ARM9

      0    Master (0=ARM9, 1=ARM7)
      1    Not used
      2-3  Offset (0..3) (slot 0..3) (LSB of address in 64Kbyte units)
      4-6  Not used
      7    Enable (0=Disable, 1=Enable)

In cooking coach, above four bytes are locked via MBK9 (not write-able, always 81h,85h,89h,8Dh)?
4004044h - DSi - MBK2.0, WRAM-B0 - 32K, mappable to ARM7, ARM9, or DSP/code
4004045h - DSi - MBK2.1, WRAM-B1 - 32K, mappable to ARM7, ARM9, or DSP/code
4004046h - DSi - MBK2.2, WRAM-B2 - 32K, mappable to ARM7, ARM9, or DSP/code
4004047h - DSi - MBK2.3, WRAM-B3 - 32K, mappable to ARM7, ARM9, or DSP/code
4004048h - DSi - MBK3.0, WRAM-B4 - 32K, mappable to ARM7, ARM9, or DSP/code
4004049h - DSi - MBK3.1, WRAM-B5 - 32K, mappable to ARM7, ARM9, or DSP/code
400404Ah - DSi - MBK3.2, WRAM-B6 - 32K, mappable to ARM7, ARM9, or DSP/code
400404Bh - DSi - MBK3.3, WRAM-B7 - 32K, mappable to ARM7, ARM9, or DSP/code

      0-1  Master (0=ARM9, 1=ARM7, 2 or 3=DSP/code)
      2-4  Offset (0..7) (slot 0..7) (LSB of address in 32Kbyte units)
      5-6  Not used (0)
      7    Enable (0=Disable, 1=Enable)

400404Ch - DSi - MBK4.0, WRAM-C0 - 32K, mappable to ARM7, ARM9, or DSP/data
400404Dh - DSi - MBK4.1, WRAM-C1 - 32K, mappable to ARM7, ARM9, or DSP/data
400404Eh - DSi - MBK4.2, WRAM-C2 - 32K, mappable to ARM7, ARM9, or DSP/data
400404Fh - DSi - MBK4.3, WRAM-C3 - 32K, mappable to ARM7, ARM9, or DSP/data
4004050h - DSi - MBK5.0, WRAM-C4 - 32K, mappable to ARM7, ARM9, or DSP/data
4004051h - DSi - MBK5.1, WRAM-C5 - 32K, mappable to ARM7, ARM9, or DSP/data
4004052h - DSi - MBK5.2, WRAM-C6 - 32K, mappable to ARM7, ARM9, or DSP/data
4004053h - DSi - MBK5.3, WRAM-C7 - 32K, mappable to ARM7, ARM9, or DSP/data

      0-1  Master (0=ARM9, 1=ARM7, 2 or 3=DSP/data)
      2-4  Offset (0..7) (slot 0..7) (LSB of address in 32Kbyte units)
      5-6  Not used (0)
      7    Enable (0=Disable, 1=Enable)

     ______________________________ Address Mapping ______________________________

MBK6-8 exist as separate READ/WRITE-ABLE registers on ARM7 and ARM9 side (making it six registers in total).
4004054h - DSi - MBK6, WRAM-A, 64K..256K mapping (R/W)

      0-3   Not used (0)
      4-11  Start Address (3000000h+N*10000h)     ;=3000000h..3FF0000h
      12-13 Image Size (0 or 1=64KB/Slot0, 2=128KB/Slot0+1+2??, 3=256KB/Slot0..3)
      14-19 Not used (0)
      20-28 End Address   (3000000h+N*10000h-1)   ;=2FFFFFFh..4FEFFFFh
      29-31 Not used (0)

4004058h - DSi - MBK7, WRAM-B (R/W)
400405Ch - DSi - MBK8, WRAM-C (R/W)

      0-2   Not used (0)
      3-11  Start Address (3000000h+N*8000h)      ;=3000000h..3FF8000h
      12-13 Image Size (0=32K/Slot0,1=64KB/Slot0-1,2=128KB/Slot0-3,3=256KB/Slot0-7)
      14-18 Not used (0)
      19-28 End Address   (3000000h+N*8000h-1)    ;=2FFFFFFh..4FF7FFFh
      29-31 Not used (0)

Uh, but, ARM7 3800000h..3FFFFFFh contains OTHER memory (ARM7-WRAM) !?

     ___________________________________ Notes ___________________________________

Slots and Image Size vs Start/End Addresses
When using Image Size of 4 slots, then Memory at 3000000h..3FFFFFFh is:

      Slots  0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,etc.

When start=6, and End=12, then (with above example), only following is mapped:

      Slots  -,-,-,-,-,-,2,3,0,1,2,3,-,-,-,-,etc.

Observe that the mapped region starts with Slot 2 (not Slot 0) in that case.
Moreover, some slots may be empty (disabled, or mapped to another CPU), so, if Slot 3 is empty (disabled or mapped to another CPU), then memory appears to look somewhat as so:

      Slots  -,-,-,-,-,-,2,z,0,1,2,z,-,-,-,-,etc.

Whereas, the "z" areas seem to read as zerofilled memory blocks (rather than mirroring to underlaying WRAM's of lower priority).
Overlapping WRAM regions

      New Shared-WRAM-A   Highest Priority
      New Shared-WRAM-B   High Priority
      New Shared-WRAM-C   Low Priority
      Old Shared-WRAM-0/1 Lowest Priority
      Old ARM7-WRAM       Whatever Priority (unknown...)
      I/O ports 4xxxxxxh  Whatever Priority (unknown...)

Overlapping WRAM slots

      Unknown what happens when selecting multiple WRAM blocks to the same slot?

The initial MBK values are derived from carthdr.
Exploits for DSi cartridges & DSiware usually have ARM7.MBK registers disabled via SCFG_EXT7, making it impossible to change that ARM7 registers; the ARM9.MBK registers are usually kept enabled, nethertheless, the ARM7.MBK9 setting can apply some restrictions to ARM9 side (for example, in Cooking Coach, WRAM-A is controlled via ARM7.MBK1, so ARM9 can control WRAM-B and WRAM-C via ARM9.MBK2-5 only).

DSi New DMA (NDMA)

The DSi has four New DMA channels for ARM7 and ARM9 each (eight New DMA channels in total). The old NDS-style DMA channels do still exist, too [though unknown which priority they have in relation to new channels].
4004100h - DSi - NDMAGCNT NewDMA Global Control (R/W) [00000000h]

      0-15  Unused (0)
      16-19 Cycle Selection (0=None, 1..15=1..16384 clks) ;1 SHL (N-1)
      20-30 Unused (0)
      31    DMA Arbitration Mode (0=NDMA0=HighestPriority, 1=RoundRobinPriority)

CycleSelection is used ONLY in RoundRobin mode; if so... then it does specify the number of cycles that can be executed by ARM9 and DSP <CPUs?> during NDMA?
4004104h+x*1Ch - NDMAxSAD - NewDMAx Source Address (R/W) [00000000h]
4004108h+x*1Ch - NDMAxDAD - NewDMAx Destination Address (R/W) [00000000h]

      0-1   Unused (0)
      2-31  DMA Source/Destination Address, in 4-byte steps

400410Ch+x*1Ch - NDMAxTCNT - NewDMAx Total Length for Repeats (R/W) [0]

      0-27  Total Number of Words to Transfer (1..0FFFFFFFh, or 0=10000000h)
      28-31 Unused (0)

Not used in "Start immediately" mode (which doesn't repeat).
Not used in "Repeat infinitely" mode (which repeats forever).
Used only in "Repeat until NDMAxTCNT" mode (for example, to define the total size of the Camera picture).
Total Length isn't required to be a multiple of the Logical or Physical Block Sizes (for example the DSi launcher uses Total=64h with Log=8/Phys=8; in that case only 4 words (instead of 8 words) are transferred for the last block).
4004110h+x*1Ch - NDMAxWCNT - NewDMAx Logical Block Size

      0-23  Number of Words to Transfer       (1..00FFFFFFh, or 0=01000000h)
      24-31 Unused (0)

Should be a multiple of the Physical Block Size specified in NDMAxCNT.Bit16-19.
The bus will be monopolized until the selected number of words for (physical) block transfers has completed, a single (physical) block transfer cycle will never be split up.
4004114h+x*1Ch - NDMAxBCNT - NewDMAx Block Transfer Timing/Interval

      0-15  Interval Timer (1..FFFFh, or 0=Infinite/TillTransferEnd)
      16-17 Prescaler (33.514MHz SHR (n*2)) ;0=33MHz, 1=8MHz, 2=2MHz, 3=0.5MHz
      18-31 Unused (0)

Allows to insert a delay after each (Physical?) Block.
4004118h+x*1Ch - NDMAxFDATA - NewDMAx Fill Data

      0-31  Fill Data (can be used as Fixed Source Data for memfill's)

This value is used when setting NDMAxCNT.Bit13-14=3, which causes the source data to be read directly (within 0 clock cycles) from the NDMAxFDATA (instead of from the address specified in NDMAxSAD; in this case, the NDMAxSAD is ignored/don't care).
400411Ch+x*1Ch - NDMAxCNT - NewDMAx Control

      0-9   Unused (0)
      10-11 Dest Address Update   (0=Increment, 1=Decrement, 2=Fixed, 3=Reserved)
      12    Dest Address Reload   (0=No, 1=Reload at (logical blk?) transfer end)
      13-14 Source Address Update (0=Increment, 1=Decrement, 2=Fixed, 3=FillData)
      15    Source Address Reload (0=No, 1=Reload at (logical blk?) transfer end)
      16-19 Physical Block Size   (0..0Fh=1..32768 words, aka (1 SHL n) words)
      20-23 Unused (0)
      24-28 DMA Startup Mode      (00h..1Fh, see ARM7/ARM9 startup lists below)
      29    DMA Repeat Mode       (0=Repeat until NDMAxTCNT, 1=Repeat infinitely)
      30    DMA Interrupt Enable  (0=Disable, 1=Enable)
      31    DMA Enable/Busy       (0=Disable, 1=Enable/Busy)

Startup Modes for ARM9:

      00h      Timer0                       ;\
      01h      Timer1                       ; new NDMA-specific modes
      02h      Timer2                       ;
      03h      Timer3                       ;/
      04h      DS Cartridge Slot
      05h      Reserved (maybe 2nd DS-Cart Slot, or GBA slot relict?)
      06h      V-Blank
      07h      H-Blank (but not during V-blank)
      08h      Display Sync (sync to H-blank drawing) ;Uh, what is BLANK-DRAWING ??
      09h      Work RAM (what?) (=probably Main memory display, as on NDS)
      0Ah      Geometry Command FIFO
      0Bh      Camera                       ;-new NDMA-specific mode
      0Ch..0Fh Reserved
      10h..1Fh Start immediately (without repeat)

Startup Modes for ARM7:

      00h      Timer0                       ;\
      01h      Timer1                       ; new NDMA-specific modes
      02h      Timer2                       ;
      03h      Timer3                       ;/
      04h      DS Cartridge Slot
      05h      Reserved? (maybe 2nd DS-Cart Slot, or GBA slot relict?)
      06h      V-Blank
      07h      NDS-Wifi
      08h      SD/MMC   (SD_DATA32_FIFO)    ;\
      09h      DSi-Wifi (SDIO_DATA32_FIFO)  ;
      0Ah      AES in   (AES_WRFIFO)        ; new NDMA-specific modes
      0Bh      AES out  (AES_RDFIFO)        ;
      0Ch      Microphone (MIC_DATA)        ;/
      0Dh..0Fh Reserved?
      10h..1Fh Start immediately (without repeat)

Start/repeat modes
There are three different transfer modes.
1) Start immediately (without repeat):
the transfer ends after one Logical Block, without repeat. With single IRQ (after last/only block).
2) Start by Hardware events, Repeat until NDMAxTCNT:
the transfer repeats Logical Blocks until reaching the Total Length. With single IRQ (after last block).
3) Start by Hardware events, Repeat infinitely:
the transfer repeats Logical Blocks infinitely. With multiple IRQs (one IRQ after EACH logical block).
Read-only Effect
There is something that can make port 4004104h..4004173h read-only. For example, when FFh-filling all DSi registers, and then 00h-filling them, then most DMA bits stay set (00h-filling them another time does clear them).
Maybe, during enabled transfers, ONLY the enable/busy bit is writeable?

DSi Microphone and SoundExt

4004600h - DSi7 - MIC_CNT - Microphone Control (can be 0000E10Fh)

      0-1   Data Format    (0=MakeStereo, 1=SameAsNormal?, 2=Normal, 3=None)  (R/W)
      2-3   Sampling Rate  (0..3=F/1, F/2, F/3, F/4)                          (R/W)
      4-7   Unused (0)                                                          (-)
      8     FIFO Empty     (0=No, 1=Empty)           ;0 words                   (R)
      9     FIFO Half-Full (0=No, 1=Half-Full)       ;8 or more words           (R)
      10    FIFO Full      (0=No, 1=Full)            ;16 words                  (R)
      11    FIFO Overrun   (0=No, 1=Overrun/Stopped) ;more than 16 words        (R)
      12    Clear FIFO     (0=No change, 1=Clear)    ;works only if bit15 was 0 (W)
      13-14 IRQ Enable     (0=Off, 1=Same as 3, 2=When Full, 3=When Half-Full)(R/W)
      15    Enable         (0=Disable, 1=Enable)                              (R/W)

The Sampling Rate depends on the I2S frequency in SNDEXCNT.Bit13,

      I2S=32.73kHz --> F/1=32.73kHz, F/2=16.36kHz, F/3=10.91kHz, F/4=8.18kHz
      I2S=47.61kHz --> F/1=47.61kHz, F/2=23.81kHz, F/3=15.87kHz, F/4=11.90kHz

The Sampling Rate becomes zero (no data arriving) when SNDEXCNT.Bit15=0, or when MIC_CNT.bit0-1=3, or when MIC_CNT.bit15=0, or when Overrun has occurred.
4004604h - DSi7 - MIC_DATA - Microphone Data (R)
The internal (and external) microphones are mono only. However, the "MakeStereo" data format can convert "mono to stereo" (ie. each sample is output twice, and 1st/2nd sample contain the same value; accordingly, the FIFO is getting full twice as fast).
MIC_DATA can be read by software, or via NDMA (with startup mode 0Ch and Blocksize 8 words).

      0-15  Signed 16bit Data, 1st sample    ;\16 words FIFO, aka 32 halfwords
      16-31 Signed 16bit Data, 2nd sample    ;/

Overrun Caution: If data isn't read fast enough then the Overrun flag will get set, and FIFO updates will be stopped. At that point one can still read the remaining 16 words from the FIFO, but no further words will be added to the FIFO (until clearing the FIFO and Overrun flag via MIC_CNT.bit12; which requires bit15=0 before setting bit12).
Microphone Touchscreen/sound control
DSi Touchscreen/Sound Init Flowcharts
The Sample Data tends to be 0000h or FFFFh if the microphone related TSC-registers aren't unmuted.
4004700h - DSi7 - SNDEXCNT (R/W)

      0-3     NITRO/DSP ratio                   (valid range is 0 to 8)       (R/W)
      4-12    Unknown/Unused (0)                                               (0?)
      13      Sound/Microphone I2S frequency (0=32.73 kHz, 1=47.61 kHz)  (R or R/W)
      14      Mute status (does NOT affect mic)          (?=Mute WHAT?)       (R/W)
      15      Enable Microphone (and Sound Output!)          (1=Enable)       (R/W)

Bit13 is write-able only if bit15 was zero before the write.
NITRO/DSP ratio
The DSP can generate sound output aswell, alongside the old NITRO sound mixer. The following settings configure the ratio between DSP and NITRO mixer output:

      00h      DSP sound 8/8, NITRO sound 0/8 (=DSP sound only)
      01h      DSP sound 7/8, NITRO sound 1/8
      02h      DSP sound 6/8, NITRO sound 2/8
      03h      DSP sound 5/8, NITRO sound 3/8
      04h      DSP sound 4/8, NITRO sound 4/8 (=half volume for DSP and NITRO each)
      05h      DSP sound 3/8, NITRO sound 5/8
      06h      DSP sound 2/8, NITRO sound 6/8
      07h      DSP sound 1/8, NITRO sound 7/8
      08h      DSP sound 0/8, NITRO sound 8/8 (=NITRO sound only)
      09h..0Fh Reserved

Uh, what is that? Hopefully, a volume-ratio? Preferably, no time-ratio!

DSi Advanced Encryption Standard (AES)

AES I/O Ports
DSi AES I/O Ports
AES Pseudo Code
Little Endian Code (as used in DSi hardware):
DSi AES Little-Endian High Level Functions
DSi AES Little-Endian Core Function and Key Schedule
DSi AES Little-Endian Tables and Test Values
Big Endian Code (as used more commonly, in non-DSi implementations):
DSi AES Big-Endian High Level Functions
DSi AES Big-Endian Core Function and Key Schedule
DSi AES Big-Endian Tables and Test Values
Most AES values are endian-free byte-strings, so different "endianness" does just mean to reverse the byte order of the 16/24/32-byte KEYs, the 16-byte data chunks, and the 16-byte CTR/CFB/CBC/MAC registers (in some of the latter cases it's also referring to actual endiannes, eg. for CTR increments).
AES Usage in DSi
AES-CCM is used for several SD/MMC files (using a custom Nintendo-specific CCM variant; consisting of 128K-byte data blocks with 32-byte footers):
DSi ES Block Encryption
AES-CTR is used for the Modcrypt areas defined in Cartridge Header, and for eMMC Boot Sectors and for eMMC MBR/Partitions.
AES Usage in DSi-Wifi
DSi Wifi is also supporting AES (and TKIP and WEP) encryption, the Wifi unit contains additional AES hardware for data packet encryption (however, Wifi EAPOL handshakes do require AES key unwrap implemented in software).
AES Usage in DSi-Shop
DSi Shop downloads (and system updates) are using big-endian AES-CBC, this does require an AES software implementation because the DSi's AES hardware couldn't decrypt that AES variant.

DSi AES I/O Ports

4004400h - DSi7 - AES_CNT (parts R/W)

      0-4   Write FIFO Count    (00h..10h words) (00h=Empty, 10h=Full)          (R)
      5-9   Read FIFO Count     (00h..10h words) (00h=Empty, 10h=Full)          (R)
      10    Write FIFO Flush    (0=No change, 1=Flush)                   (N/A or W)
      11    Read FIFO Flush     (0=No change, 1=Flush)                   (N/A or W)
      12-13 Write FIFO DMA Size (0..3 = 16,12,8,4 words) (2=Normal=8)    (R or R/W)
      14-15 Read FIFO DMA Size  (0..3 = 4,8,12,16 words) (1=Normal=8)    (R or R/W)
      16-18 CCM MAC Size, max(4,(N*2+2)) bytes, usually 7=16 bytes       (R or R/W)
      19    CCM Pass Associated Data to RDFIFO (0=No/Normal, 1=Yes)      (R or R/W)
              Bit19=1 is a bit glitchy: The data should theoretically arrive in
              RDFIFO immediately after writing 4 words to WRFIFO, but actually,
              Bit19=1 seems to cause 4 words held hidden in neither FIFO, until
              the first Payload block is written (at that point, the hidden
              associated words are suddenly appearing in RDFIFO)
      20    CCM MAC Verify Source (0=From AES_WRFIFO, 1=From AES_MAC)    (R or R/W)
      21    CCM MAC Verify Result (0=Invalid/Busy, 1=Verified/Okay)             (R)
      22-23 Unknown/Unused (0)                                                  (0)
      24    Key Select        (0=No change, 1=Apply key selected in Bit26-27)   (W)
      25    Key Schedule Busy (uh, always 0=ready?) (rather sth else busy?)     (R)
      26-27 Key Slot          (0..3=KEY0..KEY3, applied via Bit24)       (R or R/W)
      28-29 Mode (0=CCM/decrypt, 1=CCM/encrypt, 2=CTR, 3=Same as 2)      (R or R/W)
      30    Interrupt Enable  (0=Disable, 1=Enable IRQ on Transfer End)  (R or R/W)
      31    Start/Enable      (0=Disable/Ready, 1=Enable/Busy)                (R/W)

Bit31 gets cleared automatically shortly after all data (as indicated in AES_BLKCNT) is written to WRFIFO, and the IRQ is generated alongsides; the transfer isn't fully completed at that point since there may be still data (and CCM/encrypt MAC result) in RDFIFO.
4004404h - DSi7 - AES_BLKCNT (W)
Specifies the transfer length, counted in 16-byte blocks.

      0-15  Number of Extra associated data blocks for AES-CCM (unused for AES-CTR)
      16-31 Number of Payload data blocks (0..FFFFh = 0..FFFF0h bytes)

The length values are copied to internal counter registers on transfer start (the value in AES_BLKCNT is left unchanged during/after transfer).
4004408h - DSi7 - AES_WRFIFO (W)
400440Ch - DSi7 - AES_RDFIFO (R)

      0-31  Data

Writing to WRFIFO works even when AES_CNT.bit31=0 (the data does then stay in WRFIFO though, and doesn't arrive in RDFIFO).
4004420h - DSi7 - AES_IV (16 bytes) (W)
This contains the Initialization Vector (aka IV aka Nonce). The hardware does use that value to automatically initialize the internal CTR/CBC registers when starting encryption/decryption:

      For AES-CTR mode:  CTR[00h..0Fh] = AES_IV[00h..0Fh]
                         CBC[00h..0Fh] = not used by AES-CTR mode
      For AES-CCM mode:  CTR[00h..0Fh] = 00h,00h,00h,AES_IV[00h..0Bh],02h
                         CBC[00h..0Fh] = x0h,xxh,0xh,AES_IV[00h..0Bh],flg

The initial CTR/CBC values for AES-CCM mode are following the CCM specifications, but WITHOUT encoding the "extra associated data size" in upper bytes of first block (see CCM pseudo code chapter for details).
The CTR/CBC registers are manipulated during transfer, however, the AES_IV content is kept unchanged during/after transfer.
4004430h - DSi7 - AES_MAC (16 bytes) (W)
The MAC (Message Authentication Code) is an encrypted checksum, computed alongsides with the actual data encryption/decryption, and used only in AES-CCM mode. There are three ways how the DSi deals with MAC values:

      AES-CCM Encryption: MAC is returned in AES_RDFIFO after transfer
      AES-CCM Decryption, AES_CNT.20=0: MAC written to AES_WRFIFO after transfer
      AES-CCM Decryption, AES_CNT.20=1: MAC written to AES_MAC before transfer

The AES_MAC register and the RDFIFO/WRFIFO blocks are always 16-byte wide; when selecting a smaller MAC size in AES_CNT, then the lower bytes of that 16-byte value are 00h-padded (eg. a 6-byte MAC would appear as 00000000h, 00000000h, xxxx0000h, xxxxxxxxh), for ENCRYPT those 00h-bytes are returned in RDFIFO, for DECRYPT those padding bytes MUST be 00h (else the verification will fail).
The minimum MAC size is 4 bytes (trying to use 2 byte by setting AES_CNT.16-18 to 00h is producing the exact same result as when setting it to 01h, ie. 4-bytes)
4004440h - DSi7 - AES_KEY0 (48 bytes) (W)
4004470h - DSi7 - AES_KEY1 (48 bytes) (W)
40044A0h - DSi7 - AES_KEY2 (48 bytes) (W)
40044D0h - DSi7 - AES_KEY3 (48 bytes) (W)

      Byte 00h-0Fh  Normal 128bit Key      ;\use either normal key,
      Byte 10h-1Fh  Special 128bit Key_X   ; or special key_x/y
      Byte 20h-2Fh  Special 128bit Key_Y   ;/

Writing the last word of "Key_Y" (or any of its last four bytes, ie. byte(s) 2Ch..2Fh) causes the Normal Key to be overwritten by following values:

      Key = ((Key_X XOR Key_Y) + FFFEFB4E295902582A680F5F1A4F3E79h) ROL 42

After changing a key, one must (re-)apply it via AES_CNT.Bits 24,26-27.
DMA
The AES data would be usually transferred via two NDMA channels, one for WRFIFO, one for RDFIFO. The NDMAs should be started BEFORE setting AES_CNT.31 (else the DMA will miss the first WRFIFO data request; and DMA won't start). The DMAs 'Logical Block' sizes should match up with the block sizes selected in AES_CNT (a bigger logical block size would cause FIFO overruns/underruns, a smaller logical block size could work theoretically, but it practice it causes the DMA to hang after the first data request; apparently data requests are somewhat generated upon "empty-not-empty" transitions, rather than upon "enough data/space" status).
Reading Write-Only Values
The AES_IV register and the AES_KEY registers are fully write-able, including 8bit STRB writes; this allows to 'read' the write-only values via brute-force without any noticeable delay (ie. encrypt 16 bytes with original values, then change one byte to values 00h..FFh, and check which of those values gives same encryption result). AES_BLKCNT can be also dumped by simple counting.
Cartheader Key Request Byte
The firmware is usually destroying the AES_KEY registers before starting DSi programs. However, bits in CartHeader[1B4h] allow to "request" certain keys to be left intact.
DSi BIOS & Firmware Keys
The DSi BIOS contains several AES keys in the non-dumpable upper 32K halves; most of that keys are relocated to RAM/TCM, so they can be dumped via main memory hacks (there might be some further keys that cannot be dumped, in case they exist only in early boot stages).

DSi AES Little-Endian High Level Functions

AES-CTR (Counter)
aes_crypt_ctr(src,dst,len,nc_off,iv)

      aes_setkey(ENCRYPT,key,key_size]                                 ;-init key
      [ctr+0..15] = [iv+0..15]                                         ;-init ctr
      n=[nc_off]
      while len>0   ;code is 100% same for ENCRYPT and DECRYPT         ;\
        if n=0                                                         ; encrypt
          aes_crypt_block(ENCRYPT,ctr,tmp)                             ; or decrypt
          littleendian(ctr)=littleendian(ctr)+1   ;increment counter   ; message
        [dst] = [src] xor [tmp+n]                                      ;
        src=src+1, dst=dst+1, len=len-1, n=(n+1) and 0Fh               ;/
      [nc_off]=n

AES-CCM (Counter with CBC-MAC)
aes_ccm_crypt(mode,src,dst,msg_len,iv,iv_len,xtra,xtra_len,mac,mac_len)

      if mac_len<4 or mac_len>16 or (mac_len and 1)=1 then error       ;\limits
      if iv_len<7 or iv_len>13 then error                              ;/
      aes_setkey(ENCRYPT,key,key_size]                                 ;-init key
      ctr_len = 15-iv_len                                              ;\
      [ctr+15]=ctr_len-1          ;bit3..7=zero   ;1 byte (ctr_len)    ; init ctr
      [ctr+(15-iv_len)..14] = [iv+0..(iv_len-1)]  ;7..13 bytes (iv)    ;
      [ctr+0..(14-iv_len)]=littleendian(0)  ;8..2 bytes (counter=0)    ;/
      [cbc+0..15]=littleendian(msg_len)  ;-[(iv_len+1)..15]=msg_len    ;\
      if [cbc+15..15-iv_len]<>0 then error  ;msg_len overlaps iv/flags ;
      [cbc+(15-iv_len)..14]=[iv+0..iv_len-1] ;-[1..iv_len]=iv/nonce    ;
      [cbc+15].bit7=0  ;reserved/zero   ;\                             ; init cbc
      [cbc+15].bit6=(xtra_len>0)        ; [15]=flags                   ;
      [cbc+15].bit5..3=(mac_len/2-1)    ;                              ;
      [cbc+15].bit2..0=(ctr_len-1)      ;/                             ;
      aes_crypt_block(ENCRYPT,cbc,cbc)      ;UPDATE_CBC_MAC            ;/
      if NintendoDSi then                                              ;\
        a=0 ;the DSi hardware doesn't support xtra_len encoding at all ;
      elseif xtra_len<0FF00h then                                      ;
        [cbc+14..15]=[cbc+14..15] xor littleendian(xtra_len), a=2      ; weird
      elseif xtra_len<100000000h then                                  ; encoding
        [cbc+14..15]=[cbc+14..15] xor littleendian(FFFEh)              ; for
        [cbc+10..13]=[cbc+10..13] xor littleendian(xtra_len), a=6      ; xtra_len
      else                                                             ;
        [cbc+14..15]=[cbc+14..15] xor littleendian(FFFFh)              ;
        [cbc+6..13] =[cbc+6..13]  xor littleendian(xtra_len), a=10     ;/
      while xtra_len>0                                                 ;\scatter
        z=min(xtra_len,16-a)                                           ; cbc by
        [cbc+16-a-z..(15-a)]=[cbc+16-a-z..(15-a)] xor [xtra+0..(z-1)]  ; xtra
        aes_crypt_block(ENCRYPT,cbc,cbc)    ;UPDATE_CBC_MAC            ; (if any)
        xtra=xtra+z, xtra_len=xtra_len-z, a=0                          ;/
      while msg_len>0                                                  ;\
        littleendian(ctr)=littleendian(ctr)+1   ;increment counter     ;
        aes_crypt_block(ENCRYPT,ctr,tmp)    ;CTR_CRYPT                 ;
        z=min(msg_len,16)                                              ; encrypt
        if mode=ENCRYPT                                                ; or decrypt
          [cbc+(16-z)..15] = [cbc+(16-z)..15] xor [src+0..(z-1)]       ; message
        [dst+0..(z-1)] = [src+0..(z-1)] xor [tmp+(16-z)..15]           ; body
        if mode=DECRYPT                                                ;
          [cbc+(16-z)..15] = [cbc+(16-z)..15] xor [dst+0..(z-1)]       ;
        aes_crypt_block(ENCRYPT,cbc,cbc)    ;UPDATE_CBC_MAC            ;
        src=src+z, dst=dst+z, msg_len=msg_len-z                        ;/
      [ctr+0..(14-iv_len)]=littleendian(0)  ;reset counter=0           ;\
      aes_crypt_block(ENCRYPT,ctr,tmp)      ;CTR_CRYPT                 ; message
      [cbc+0..15] = [cbc+0..15] xor [tmp+0..15]                        ; auth code
      z=mac_len                                                        ; (mac)
      IF mode=ENCRYPT then [mac+0..(z-1)] = [cbc+(16-z)..15]           ;
      IF mode=DECRYPT and [mac+0..(z-1)] <> [cbc+(16-z)..15] then error;/

AES-Key-Wrap/Unwrap
This is used for EAPOL Key Data in WPA2 Wifi packets, however, neither DSi-ARM7 nor DSi-Wifi do support that by hardware, so the unwrap (decrypt) must be implemented by software. For details see:
DS Wifi WPA/WPA2 Encryption
Below are some other AES variants (just for curiosity - those variants aren't used in DSi):
AES-CBC (Cipher-block chaining)
aes_crypt_cbc(mode,src,dst,len,iv)

      aes_setkey(mode,key,key_size]                                    ;-init key
      [cbc+0..15] = [iv+0..15]                                         ;-init cbc
      if (len AND 0Fh)>0 then error
      while len>0                                                      ;\
        if mode=ENCRYPT                                                ;
          [dst+0..15] = [src+0..15] xor [cbc+0..15]                    ;
          aes_crypt_block(mode,dst,dst)                                ; encrypt
          [cbc+0..15] = [dst+0..15]                                    ; or decrypt
        if mode=DECRYPT                                                ; message
          [tmp+0..15] = [src+0..15]                                    ;
          aes_crypt_block(mode,src,dst)                                ;
          [dst+0..15] = [dst+0..15] xor [cbc+0..15]                    ;
          [cbc+0..15] = [tmp+0..15]                                    ;
        src=src+16, dst=dst+16, len=len-16                             ;/

AES-CFB128 (Cipher feedback on 128bits, aka 16 bytes)
aes_crypt_cfb128(mode,src,dst,len,iv_off,iv)

      aes_setkey(ENCRYPT,key,key_size]                                 ;-init key
      [cfb+0..15] = [iv+0..15]                                         ;-init cfb
      n=[iv_off]
      while len>0                                                      ;\
        if n=0 then aes_crypt_block(ENCRYPT,cfb,cfb)                   ; encrypt
        if mode=DECRYPT then c=[src], [dst]=c xor [cfb+n], [cfb+n]=c   ; or decrypt
        if mode=ENCRYPT then c=[cfb+n] xor [src], [cfb+n]=c, [dst]=c   ; message
        src=src+1, dst=dst+1, len=len-1, n=(n+1) and 0Fh               ;/
      [iv_off]=n

AES-CFB8 (Cipher feedback on 8bits, aka 1 byte, very inefficient)
aes_crypt_cfb8(mode,src,dst,len,iv)

      aes_setkey(ENCRYPT,key,key_size]                                 ;-init key
      [cfb+0..15] = [iv+0..15]                                         ;-init cfb
      n=[iv_off]
      while len>0                                                      ;\
        aes_crypt_block(ENCRYPT,cfb,tmp)                               ;
        [cfb+1..15] = [cfb+0..14]   ;shift with 8-bit step             ; encrypt
        if mode=DECRYPT then [cfb+0] = [src+(n xor 0Fh)]               ; or decrypt
        [dst+(n xor 0Fh)] = [src+(n xor 0Fh)] xor [tmp+15]  ;shift-in  ; message
        if mode=ENCRYPT then [cfb+0] = [dst+(n xor 0Fh)]               ;
        len=len-1, n=n+1                                               ;/
      [iv_off]=n

AES-ECB (Electronic codebook, very basic, very insecure)
aes_crypt_ecb(mode,src,dst,len)

      aes_setkey(mode,key,key_size]                                    ;-init key
      if (len AND 0Fh)>0 then error
      while len>0                                                      ;\encrypt
        aes_crypt_block(mode,src,dst)                                  ; or decrypt
        src=src+16, dst=dst+16, len=len-16                             ;/message

DSi AES Little-Endian Core Function and Key Schedule

     aes_crypt_block(mode,src,dst):
      Y0 = RK[0] xor [src+00h]
      Y1 = RK[1] xor [src+04h]
      Y2 = RK[2] xor [src+08h]
      Y3 = RK[3] xor [src+0Ch]
      ;below code depending on mode:      <---ENCRYPT--->  -or-  <---DECRYPT--->
      for i=1 to nr-1
        X0      = RK[i*4+0] xor scatter32(FT,Y1,Y2,Y3,Y0)  -or-  (RT,Y3,Y2,Y1,Y0)
        X1      = RK[i*4+1] xor scatter32(FT,Y2,Y3,Y0,Y1)  -or-  (RT,Y0,Y3,Y2,Y1)
        X2      = RK[i*4+2] xor scatter32(FT,Y3,Y0,Y1,Y2)  -or-  (RT,Y1,Y0,Y3,Y2)
        X3      = RK[i*4+3] xor scatter32(FT,Y0,Y1,Y2,Y3)  -or-  (RT,Y2,Y1,Y0,Y3)
        Y0=X0, Y1=X1, Y2=X2, Y3=X3
      [dst+00h] = RK[nr*4+0] xor scatter8(FSb,Y1,Y2,Y3,Y0) -or-  (RSb,Y3,Y2,Y1,Y0)
      [dst+04h] = RK[nr*4+1] xor scatter8(FSb,Y2,Y3,Y0,Y1) -or-  (RSb,Y0,Y3,Y2,Y1)
      [dst+08h] = RK[nr*4+2] xor scatter8(FSb,Y3,Y0,Y1,Y2) -or-  (RSb,Y1,Y0,Y3,Y2)
      [dst+0Ch] = RK[nr*4+3] xor scatter8(FSb,Y0,Y1,Y2,Y3) -or-  (RSb,Y2,Y1,Y0,Y3)

     scatter32(TAB,a,b,c,d):              scatter8(TAB,a,b,c,d):
      w=      (TAB[a.bit0..7] ror 24)      w.bit0..7   = TAB[a.bit0..7]
      w=w xor (TAB[b.bit8..15] ror 16)     w.bit8..15  = TAB[b.bit8..15]
      w=w xor (TAB[c.bit16..23] ror 8)     w.bit16..23 = TAB[c.bit16..23]
      w=w xor (TAB[d.bit24..31])           w.bit24..31 = TAB[d.bit24..31]
      return w                             return w

     aes_setkey(mode,key,keysize):  ;out: RK[0..43/51/59], nr=10/12/14
      aes_generate_tables   ;<-- unless tables are already initialized
      if keysize<>128 and keysize<>192 and keysize<>256 then error  ;size in bits
      rc=01h, j=0, jj=keysize/32, nr=jj+6   ;jj=4,6,8      ;\
      for i=0 to (nr+1)*4-1                 ;nr=10,12,14   ; copy 16/24/32-byte key
        if i<jj then w=[key+(jj-1-i)*4+0..3]               ; to RK[0..3/5/7]
        else w=w xor RK[(i-jj) xor 3]                      ; and, make
        RK[i xor 3]=w, j=j+1                               ; RK[4/6/8..43/51/59]
        if j=jj then                                       ;
          w=scatter8(FSb,w,w,w,w)                          ;
          w=(w rol 8) xor (rc shl 24)                      ;
          j=0, rc=rc*2, if rc>0FFh then rc=rc xor 11Bh     ;
        if j=4 and jj=8 then w=scatter8(FSb,w,w,w,w)       ;/
      if mode=DECRYPT then
        for i=0 to nr/2-1     ;swap entries (except middle one)
          for j=0 to 3
            w=RK[i*4+j], v=RK[nr*4-i*4+j]
            RK[i*4+j]=v, RK[nr*4-i*4+j]=w
        for i=4 to nr*4-1     ;modify entries (except RK[0..3] and RK[nr*4+0..3])
          w=RK[i], w=scatter8(FSb,w,w,w,w), RK[i]=scatter32(RT,w,w,w,w)

DSi AES Little-Endian Tables and Test Values

     aes_generate_tables:
      for i=0 to 0FFh               ;compute pow and log tables...
        if i=0 then x=01h, else x=x xor x*2, if x>0FFh then x=x xor 11Bh
        pow[i]=x, log[x]=i
      for i=0 to 0FFh               ;generate the forward and reverse S-boxes...
        x=pow[0FFh-log[i]]
        x=x xor (x rol 1) xor (x rol 2) xor (x rol 3) xor (x rol 4) xor 63h
        if i=0 then x=63h
        FSb[i]=x, RSb[x]=i
      for i=0 to 0FFh               ;generate the forward and reverse tables...
        x=FSb[i]*2, if x>0FFh then x=x xor 11Bh
        FT[i]=(FSb[i]*00010101h) xor (x*01000001h)
        w=00000000h, x=RSb[i]
        if x<>00h then   ;ie. not at i=63h
          w=w+pow[(log[x]+log[0Eh]) mod 00FFh]*1000000h
          w=w+pow[(log[x]+log[09h]) mod 00FFh]*10000h
          w=w+pow[(log[x]+log[0Dh]) mod 00FFh]*100h
          w=w+pow[(log[x]+log[0Bh]) mod 00FFh]*1h
        RT[i]=w

     aes_generate_tables_results:
      pow[00h..FFh] = 01,03,05,0F,11,..,C7,52,F6,01   ;pow  ;\needed temporarily
      log[00h..FFh] = 00,FF,19,01,32,..,C0,F7,70,07   ;log  ;/for table creation
      FSb[00h..FFh] = 63,7C,77,7B,F2,..,B0,54,BB,16   ;Forward S-box
      RSb[00h..FFh] = 52,09,6A,D5,30,..,55,21,0C,7D   ;Reverse S-box
      FT[00h..FFh] = C66363A5,F87C7C84,..,2C16163A    ;Forward Table
      RT[00h..FFh] = 51F4A750,7E416553,..,D0B85742    ;Reverse Table

     aes_setkey_results:
      key = "AES-Test-Key-Str-1234567-Abcdefg"  ;use only 1st bytes for 128/192bit
      128bit ENCRYPT --> RK[0..9..30..43] = 2D534541..2783080F..93AF7DF0..827EE10D
      192bit ENCRYPT --> RK[0..9..30..51] = 79654B2D..9708FA95..2529372B..C66C19FA
      256bit ENCRYPT --> RK[0..9..30..59] = 3332312D..DF5C92A5..74174E2E..3C8ADAE6
      128bit DECRYPT --> RK[0..9..30..43] = AEABCD4D..ECD33F19..8C87B246..7274532D
      192bit DECRYPT --> RK[0..9..30..51] = AFA9796F..72A3EFE5..455646C7..37363534
      256bit DECRYPT --> RK[0..9..30..59] = 0ED52830..4601F929..415A7D65..67666564

     aes_crypt_results:
      [key+0..15]    = "AES-Test-Key-Str-1234567-Abcdefg"
      [iv+0..15]     = "Nonce/InitVector"
      [xtra+0..20]   = "Extra-Associated-Data"  ;\for CCM
      iv_len=12, mac_len=16, xtra_len=xx        ;/
      Unencrypted:   [dta+0..113Fh] = "Unencrypted-Data", 190h x "TestPadding"
      AES-ECB:       [dta+0..113Fh] = 20,24,73,88,..,44,A8,D6,A8  ;\
      AES-CBC:       [dta+0..113Fh] = A4,6F,7A,F2,..,58,C9,02,B4  ;
      AES-CFB128:    [dta+0..113Fh] = 20,C6,DB,35,..,9A,83,7F,DB  ; keysize=128
      AES-CFB8:      [dta+0..113Fh] = 55,C7,75,1C,..,24,6E,A6,D1  ;
      AES-CTR:       [dta+0..113Fh] = 20,C6,DB,35,..,AB,09,0C,75  ;
      AES-CCM:       [dta+0..113Fh] = C8,37,D7,F1,..,7B,EF,FC,12  ;
      AES-CCM (ori): [mac+0..0Fh]   = xx,xx,xx,xx,..,xx,xx,xx,xx  ;
      AES-CCM (DSi): [mac+0..0Fh]   = xx,xx,xx,xx,..,xx,xx,xx,xx  ;/
      AES-ECB:       [dta+0..113Fh] = CC,B6,4D,17,..,D3,56,3E,64  ;-keysize=192
      AES-ECB:       [dta+0..113Fh] = A9,A9,9B,3E,..,8A,C6,13,A1  ;-keysize=256

DSi AES Big-Endian High Level Functions

AES-CTR (Counter)
aes_crypt_ctr(src,dst,len,nc_off,iv)

      aes_setkey(ENCRYPT,key,key_size]                                 ;-init key
      [ctr+0..15] = [iv+0..15]                                         ;-init ctr
      n=[nc_off]
      while len>0   ;code is 100% same for ENCRYPT and DECRYPT         ;\
        if n=0                                                         ; encrypt
          aes_crypt_block(ENCRYPT,ctr,tmp)                             ; or decrypt
          bigendian(ctr)=bigendian(ctr)+1     ;increment counter       ; message
        [dst] = [src] xor [tmp+n]                                      ;
        src=src+1, dst=dst+1, len=len-1, n=(n+1) and 0Fh               ;/
      [nc_off]=n

AES-CCM (Counter with CBC-MAC)
aes_ccm_crypt(mode,src,dst,msg_len,iv,iv_len,xtra,xtra_len,mac,mac_len)

      if mac_len<4 or mac_len>16 or (mac_len and 1)=1 then error       ;\limits
      if iv_len<7 or iv_len>13 then error                              ;/
      aes_setkey(ENCRYPT,key,key_size]                                 ;-init key
      ctr_len = 15-iv_len                                              ;\
      [ctr+0]=ctr_len-1     ;bit3..7=zero   ;1 byte (ctr_len)          ; init ctr
      [ctr+1..iv_len] = [iv+0..(iv_len-1)]  ;7..13 bytes (iv)          ;
      [ctr+(iv_len+1)..15]=bigendian(0)     ;8..2 bytes (counter=0)    ;/
      [cbc+0..15]=bigendian(msg_len)   ;-[(iv_len+1)..15]=msg_len      ;\
      if [cbc+0..iv_len]<>0 then error ;errif msg_len overlaps iv/flags;
      [cbc+1..iv_len]=[iv+0..iv_len-1] ;-[1..iv_len]=iv (aka nonce)    ;
      [cbc+0].bit7=0  ;reserved/zero   ;\                              ; init cbc
      [cbc+0].bit6=(xtra_len>0)        ; [0]=flags                     ;
      [cbc+0].bit5..3=(mac_len/2-1)    ;                               ;
      [cbc+0].bit2..0=(ctr_len-1)      ;/                              ;
      aes_crypt_block(ENCRYPT,cbc,cbc)      ;UPDATE_CBC_MAC            ;/
      if NintendoDSi then                                              ;\
        a=0 ;the DSi hardware doesn't support xtra_len encoding at all ;
      elseif xtra_len<0FF00h then                                      ;
        [cbc+0..1]=[cbc+0..1] xor bigendian(xtra_len), a=2             ; weird
      elseif xtra_len<100000000h then                                  ; encoding
        [cbc+0..1]=[cbc+0..1] xor bigendian(FFFEh)                     ; for
        [cbc+2..5]=[cbc+2..5] xor bigendian(xtra_len), a=6             ; xtra_len
      else                                                             ;
        [cbc+0..1]=[cbc+0..1] xor bigendian(FFFFh)                     ;
        [cbc+2..9]=[cbc+2..9] xor bigendian(xtra_len), a=10            ;/
      while xtra_len>0                                                 ;\scatter
        z=min(xtra_len,16-a)                                           ; cbc by
        [cbc+a..(a+z-1)]=[cbc+a..(a+z-1)] xor [xtra+0..(z-1)]          ; xtra
        aes_crypt_block(ENCRYPT,cbc,cbc)    ;UPDATE_CBC_MAC            ; (if any)
        xtra=xtra+z, xtra_len=xtra_len-z, a=0                          ;/
      while msg_len>0                                                  ;\
        bigendian(ctr)=bigendian(ctr)+1     ;increment counter         ;
        aes_crypt_block(ENCRYPT,ctr,tmp)    ;CTR_CRYPT                 ;
        z=min(msg_len,16)                                              ; encrypt
        if mode=ENCRYPT                                                ; or decrypt
          [cbc+0..(z-1)] = [cbc+0..(z-1)] xor [src+0..(z-1)]           ; message
        [dst+0..(z-1)] = [src+0..(z-1)] xor [tmp+0..(z-1)]             ; body
        if mode=DECRYPT                                                ;
          [cbc+0..(z-1)] = [cbc+0..(z-1)] xor [dst+0..(z-1)]           ;
        aes_crypt_block(ENCRYPT,cbc,cbc)    ;UPDATE_CBC_MAC            ;
        src=src+z, dst=dst+z, msg_len=msg_len-z                        ;/
      [ctr+(iv_len+1)..15]=bigendian(0)     ;reset counter=0           ;\
      aes_crypt_block(ENCRYPT,ctr,tmp)      ;CTR_CRYPT                 ; message
      [cbc+0..15] = [cbc+0..15] xor [tmp+0..15]                        ; auth code
      z=mac_len                                                        ; (mac)
      IF mode=ENCRYPT then [mac+0..(z-1)] = [cbc+0..(z-1)]             ;
      IF mode=DECRYPT and [mac+0..(z-1)] <> [cbc+0..(z-1)] then error  ;/

AES-Key-Wrap/Unwrap
This is used for EAPOL Key Data in WPA2 Wifi packets, however, neither DSi-ARM7 nor DSi-Wifi do support that by hardware, so the unwrap (decrypt) must be implemented by software. For details see:
DS Wifi WPA/WPA2 Encryption
Below are some other AES variants (just for curiosity - those variants aren't used in DSi):
AES-CBC (Cipher-block chaining)
aes_crypt_cbc(mode,src,dst,len,iv)

      aes_setkey(mode,key,key_size]                                    ;-init key
      [cbc+0..15] = [iv+0..15]                                         ;-init cbc
      if (len AND 0Fh)>0 then error
      while len>0                                                      ;\
        if mode=ENCRYPT                                                ;
          [dst+0..15] = [src+0..15] xor [cbc+0..15]                    ;
          aes_crypt_block(mode,dst,dst)                                ; encrypt
          [cbc+0..15] = [dst+0..15]                                    ; or decrypt
        if mode=DECRYPT                                                ; message
          [tmp+0..15] = [src+0..15]                                    ;
          aes_crypt_block(mode,src,dst)                                ;
          [dst+0..15] = [dst+0..15] xor [cbc+0..15]                    ;
          [cbc+0..15] = [tmp+0..15]                                    ;
        src=src+16, dst=dst+16, len=len-16                             ;/

AES-CFB128 (Cipher feedback on 128bits, aka 16 bytes)
aes_crypt_cfb128(mode,src,dst,len,iv_off,iv)

      aes_setkey(ENCRYPT,key,key_size]                                 ;-init key
      [cfb+0..15] = [iv+0..15]                                         ;-init cfb
      n=[iv_off]
      while len>0                                                      ;\
        if n=0 then aes_crypt_block(ENCRYPT,cfb,cfb)                   ; encrypt
        if mode=DECRYPT then c=[src], [dst]=c xor [cfb+n], [cfb+n]=c   ; or decrypt
        if mode=ENCRYPT then c=[cfb+n] xor [src], [cfb+n]=c, [dst]=c   ; message
        src=src+1, dst=dst+1, len=len-1, n=(n+1) and 0Fh               ;/
      [iv_off]=n

AES-CFB8 (Cipher feedback on 8bits, aka 1 byte, very inefficient)
aes_crypt_cfb8(mode,src,dst,len,iv)

      aes_setkey(ENCRYPT,key,key_size]                                 ;-init key
      [cfb+0..15] = [iv+0..15]                                         ;-init cfb
      while len>0                                                      ;\
        aes_crypt_block(ENCRYPT,cfb,tmp)                               ;
        [cfb+0..14] = [cfb+1..15]   ;shift with 8-bit step             ; encrypt
        if mode=DECRYPT then [cfb+15] = [src]                          ; or decrypt
        [dst] = [src] xor [tmp+0]   ;shift-in new 8-bits               ; message
        if mode=ENCRYPT then [cfb+15] = [dst]                          ;
        src=src+1, dst=dst+1, len=len-1                                ;/

AES-ECB (Electronic codebook, very basic, very insecure)
aes_crypt_ecb(mode,src,dst,len)

      aes_setkey(mode,key,key_size]                                    ;-init key
      if (len AND 0Fh)>0 then error
      while len>0                                                      ;\encrypt
        aes_crypt_block(mode,src,dst)                                  ; or decrypt
        src=src+16, dst=dst+16, len=len-16                             ;/message

DSi AES Big-Endian Core Function and Key Schedule

     aes_crypt_block(mode,src,dst):
      Y0 = RK[0] xor [src+00h]
      Y1 = RK[1] xor [src+04h]
      Y2 = RK[2] xor [src+08h]
      Y3 = RK[3] xor [src+0Ch]
      ;below code depending on mode:      <---ENCRYPT--->  -or-  <---DECRYPT--->
      for i=1 to nr-1
        X0      = RK[i*4+0] xor scatter32(FT,Y0,Y1,Y2,Y3)  -or-  (RT,Y0,Y3,Y2,Y1)
        X1      = RK[i*4+1] xor scatter32(FT,Y1,Y2,Y3,Y0)  -or-  (RT,Y1,Y0,Y3,Y2)
        X2      = RK[i*4+2] xor scatter32(FT,Y2,Y3,Y0,Y1)  -or-  (RT,Y2,Y1,Y0,Y3)
        X3      = RK[i*4+3] xor scatter32(FT,Y3,Y0,Y1,Y2)  -or-  (RT,Y3,Y2,Y1,Y0)
        Y0=X0, Y1=X1, Y2=X2, Y3=X3
      [dst+00h] = RK[nr*4+0] xor scatter8(FSb,Y0,Y1,Y2,Y3) -or-  (RSb,Y0,Y3,Y2,Y1)
      [dst+04h] = RK[nr*4+1] xor scatter8(FSb,Y1,Y2,Y3,Y0) -or-  (RSb,Y1,Y0,Y3,Y2)
      [dst+08h] = RK[nr*4+2] xor scatter8(FSb,Y2,Y3,Y0,Y1) -or-  (RSb,Y2,Y1,Y0,Y3)
      [dst+0Ch] = RK[nr*4+3] xor scatter8(FSb,Y3,Y0,Y1,Y2) -or-  (RSb,Y3,Y2,Y1,Y0)

     scatter32(TAB,a,b,c,d):              scatter8(TAB,a,b,c,d):
      w=      (TAB[a.bit0..7])             w.bit0..7   = TAB[a.bit0..7]
      w=w xor (TAB[b.bit8..15] rol 8)      w.bit8..15  = TAB[b.bit8..15]
      w=w xor (TAB[c.bit16..23] rol 16)    w.bit16..23 = TAB[c.bit16..23]
      w=w xor (TAB[d.bit24..31] rol 24)    w.bit24..31 = TAB[d.bit24..31]
      return w                             return w

     aes_setkey(mode,key,keysize):  ;out: RK[0..43/51/59], nr=10/12/14
      aes_generate_tables   ;<-- unless tables are already initialized
      if keysize<>128 and keysize<>192 and keysize<>256 then error  ;size in bits
      rc=01h, j=0, jj=keysize/32, nr=jj+6   ;jj=4,6,8      ;\
      for i=0 to (nr+1)*4-1                 ;nr=10,12,14   ; copy 16/24/32-byte key
        if i<jj then w=[key+i*4+0..3]                      ; to RK[0..3/5/7]
        else w=w xor RK[i-jj]                              ; and, make
        RK[i]=w, j=j+1                                     ; RK[4/6/8..43/51/59]
        if j=jj then                                       ;
          w=scatter8(FSb,w,w,w,w)                          ;
          w=(w ror 8) xor (rc)                             ;
          j=0, rc=rc*2, if rc>0FFh then rc=rc xor 11Bh     ;
        if j=4 and jj=8 then w=scatter8(FSb,w,w,w,w)       ;/
      if mode=DECRYPT then
        for i=0 to nr/2-1     ;swap entries (except middle one)
          for j=0 to 3
            w=RK[i*4+j], v=RK[nr*4-i*4+j]
            RK[i*4+j]=v, RK[nr*4-i*4+j]=w
        for i=4 to nr*4-1     ;modify entries (except RK[0..3] and RK[nr*4+0..3])
          w=RK[i], w=scatter8(FSb,w,w,w,w), RK[i]=scatter32(RT,w,w,w,w)

DSi AES Big-Endian Tables and Test Values

     aes_generate_tables:
      for i=0 to 0FFh               ;compute pow and log tables...
        if i=0 then x=01h, else x=x xor x*2, if x>0FFh then x=x xor 11Bh
        pow[i]=x, log[x]=i
      for i=0 to 0FFh               ;generate the forward and reverse S-boxes...
        x=pow[0FFh-log[i]]
        x=x xor (x rol 1) xor (x rol 2) xor (x rol 3) xor (x rol 4) xor 63h
        if i=0 then x=63h
        FSb[i]=x, RSb[x]=i
      for i=0 to 0FFh               ;generate the forward and reverse tables...
        x=FSb[i]*2, if x>0FFh then x=x xor 11Bh
        FT[i]=(FSb[i]*01010100h) xor (x*01000001h)
        w=00000000h, x=RSb[i]
        if x<>00h then   ;ie. not at i=63h
          w=w+pow[(log[x]+log[0Eh]) mod 00FFh]*1h
          w=w+pow[(log[x]+log[09h]) mod 00FFh]*100h
          w=w+pow[(log[x]+log[0Dh]) mod 00FFh]*10000h
          w=w+pow[(log[x]+log[0Bh]) mod 00FFh]*1000000h
        RT[i]=w

     aes_generate_tables_results:
      pow[00h..FFh] = 01,03,05,0F,11,..,C7,52,F6,01   ;pow  ;\needed temporarily
      log[00h..FFh] = 00,FF,19,01,32,..,C0,F7,70,07   ;log  ;/for table creation
      FSb[00h..FFh] = 63,7C,77,7B,F2,..,B0,54,BB,16   ;Forward S-box
      RSb[00h..FFh] = 52,09,6A,D5,30,..,55,21,0C,7D   ;Reverse S-box
      FT[00h..FFh] = A56363C6,847C7CF8,..,3A16162C    ;Forward Table
      RT[00h..FFh] = 50A7F451,5365417E,..,4257B8D0    ;Reverse Table

     aes_setkey_results:
      key = "AES-Test-Key-Str-1234567-Abcdefg"  ;use only 1st bytes for 128/192bit
      128bit ENCRYPT --> RK[0..9..30..43] = 2D534541..ED0DC6FA..43DAC81C..0F5026BB
      192bit ENCRYPT --> RK[0..9..30..51] = 2D534541..4AAB3D82..29CA38D2..CA4DFE3B
      256bit ENCRYPT --> RK[0..9..30..59] = 2D534541..1AA51359..CCB886C8..88956C9C
      128bit DECRYPT --> RK[0..9..30..43] = F653079B..47DD8A1C..1C2070A7..7274532D
      192bit DECRYPT --> RK[0..9..30..51] = 3CEC6AFF..C4F96B6F..AE36B4AE..7274532D
      256bit DECRYPT --> RK[0..9..30..59] = DE7ADCD9..8C559ADD..067A387E..7274532D

     aes_crypt_results:
      [key+0..15]    = "AES-Test-Key-Str-1234567-Abcdefg"
      [iv+0..15]     = "Nonce/InitVector"
      [xtra+0..20]   = "Extra-Associated-Data"  ;\for CCM
      iv_len=12, mac_len=16, xtra_len=21        ;/
      Unencrypted:   [dta+0..113Fh] = "Unencrypted-Data", 190h x "TestPadding"
      AES-ECB:       [dta+0..113Fh] = 5F,BD,04,DB,..,E4,07,F4,B6  ;\
      AES-CBC:       [dta+0..113Fh] = 0B,BB,53,FA,..,DD,28,6D,AE  ;
      AES-CFB128:    [dta+0..113Fh] = F4,75,4F,0E,..,73,B5,D7,E7  ; keysize=128
      AES-CFB8:      [dta+0..113Fh] = F4,10,6A,83,..,BF,1B,16,3E  ;
      AES-CTR:       [dta+0..113Fh] = F4,75,4F,0E,..,04,DF,EB,BA  ;
      AES-CCM:       [dta+0..113Fh] = FD,1A,6D,98,..,EE,FD,68,F6  ;
      AES-CCM (ori): [mac+0..0Fh]   = FD,F9,FE,85,..,4F,50,3C,AF  ;
      AES-CCM (DSi): [mac+0..0Fh]   = xx,xx,xx,xx,..,xx,xx,xx,xx  ;/
      AES-ECB:       [dta+0..113Fh] = 0E,69,F5,1A,..,9A,5F,7A,9A  ;-keysize=192
      AES-ECB:       [dta+0..113Fh] = C6,FB,68,C1,..,14,89,6C,E0  ;-keysize=256

DSi ES Block Encryption

ES Block Encryption, for lack of a better name, is a Nintendo DSi specific data encryption method. It's used for some SD/MMC files:

      FAT16:\sys\dev.kp
      FAT16:\ticket\000300tt\4ggggggg.tik (tickets)
      SD Card: .bin files (aka Tad Files) (contains multiple blocks)
      .twl-*.der files (within the "verdata" NARC file)

Block Layout

      00000h      BLKLEN   Data Block      (AES-CCM encrypted)
      BLKLEN+00h  10h      Data Checksum   (AES-CCM MAC value on above Data)
      BLKLEN+10h  1        Fixed 3Ah       (AES-CTR encrypted)
      BLKLEN+11h  0Ch      Nonce           (unencrypted)
      BLKLEN+1Dh  1        BLKLEN.bit16-23 (AES-CTR encrypted)
      BLKLEN+1Eh  1        BLKLEN.bit8-15  (AES-CTR encrypted)
      BLKLEN+1Fh  1        BLKLEN.bit0-7   (AES-CTR encrypted)

BLKLEN can be max 20000h. If the Data is bigger than 128Kbytes, then it's split into multiple block(s) with BLKLEN=20000h (the last block can have smaller BLKLEN).
Data Block Encryption/Decryption (AES-CCM)

      IV[00h..0Bh]=[BLKLEN+11h..1Ch]  ;Nonce
      IV[0Ch..0Fh]=Don't care (not used for CCM)

With that IV value, apply AES-CCM on the Data Block:

      00000h      BLKLEN   Data Block      (AES-CCM)

Observe that some DSi files have odd BLKLEN values, so you may need to append padding bytes to the Data Block (the DSi hardware requires full 16-byte chunks for encryption/decryption).
Alternately, one could use AES-CTR for decryption (this may be faster/easier, and allows random access, though without MAC verify), using this IV value:

      IV[00h..02h]=offset/10h + 1     ;CTR value for desired 16-byte block
      IV[03h..0Eh]=[BLKLEN+11h..1Ch]  ;Nonce for CTR
      IV[0Fh]=02h                     ;Indicate 3-byte wide CTR (fixed on DSi)

Data Block Padding (16-byte alignment)
For encryption, it's simple: Just append 00h byte(s) as padding value.
For decryption, it's more complicated: The padding values should be ENCRYPTED 00h-bytes (required to get the same MAC result as for encryption). If you don't want to verify the MAC, then you could append whatever dummy bytes. If you want to verify the MAC, then you could pre-calculate the padding values as so:

      IV[00h..02h]=BLKLEN/10h + 1     ;CTR value for last 16-byte block
      IV[03h..0Eh]=[BLKLEN+11h..1Ch]  ;Nonce
      IV[0Fh]=02h                     ;Indicate 3-byte wide CTR (fixed on DSi)

Then, use AES-CTR (not CCM) to encrypt sixteen 00h-bytes, the last byte(s) of the result can be then used as padding value(s). The padding values should be pre-calculated BEFORE starting the CCM decryption (the DSi hardware allows only one AES task at once, so they cannot be calculated via AES-CTR when AES-CCM decryption is in progress).
Verifying the Footer values (AES-CTR)
This step is needed only for verification purposes (encryption tools should create these values, but decryption tools may or may not verify them).

      IV[00h]=00h                     ;Zero
      IV[01h..0Ch]=[BLKLEN+11h..1Ch]  ;Nonce
      IV[0Dh..0Fh]=00h,00h,00h        ;Zero

With that IV value (and same Key as for AES-CCM), apply AES-CTR on the last 16 bytes of the block:

      BLKLEN+10h  1        Fixed 3Ah       (AES-CTR encrypted)
      BLKLEN+11h  0Ch      Nonce           (unencrypted)
      BLKLEN+1Dh  1        BLKLEN.bit16-23 (AES-CTR encrypted)
      BLKLEN+1Eh  1        BLKLEN.bit8-15  (AES-CTR encrypted)
      BLKLEN+1Fh  1        BLKLEN.bit0-7   (AES-CTR encrypted)

AES-CTR is XORing the data stream (encrypted bytes will turn into unencrypted bytes, and vice-versa), so the result would look as so:

      BLKLEN+10h  1        Fixed 3Ah       (unencrypted)       (to be verified)
      BLKLEN+11h  0Ch      Nonce           (AES-CTR encrypted) (useless/garbage)
      BLKLEN+1Dh  1        BLKLEN.bit16-23 (unencrypted)       (to be verified)
      BLKLEN+1Eh  1        BLKLEN.bit8-15  (unencrypted)       (to be verified)
      BLKLEN+1Fh  1        BLKLEN.bit0-7   (unencrypted)       (to be verified)

Mind that BLKLEN can be odd, so data at BLKLEN+00h..1Fh isn't necessarily located at 4-byte aligned addresses.

DSi Cartridge Header

Old NDS Header Entries
The first 180h bytes of the DSi Header are essentially same as on NDS:
DS Cartridge Header
New/changed entries in DSi carts are:

      012h 1    Unitcode (00h=NDS, 02h=NDS+DSi, 03h=DSi) (bit1=DSi)
      01Ch 1    NDS: Reserved / DSi: Flags (03h=Normal, 0Bh=Sys, 0Fh=Debug/Sys)
                  bit0 Has TWL-Exclusive Region      ;MUST be 1 for DSi titles?
                  bit1 Modcrypted (0=No, 1=Yes, see [220h..22Fh])
                  bit2 Modcrypt key select (0=Retail, 1=Debug)
                  bit3 Disable Debug ?
      01Dh 1    NDS: Region   / DSi: Permit jump (00h=Normal, 01h=System Settings)
                                 bit0 jump (always include title at [2FFD800h..])
                                 bit1 tmpjump (?)
      068h 4    Icon/Title offset (same as NDS, but with new extra entries)
      080h 4    Total Used ROM size, EXCLUDING DSi area
      088h 4    NDS: Reserved / ARM9 Parameters Table Offset ???  ;base=[028h]
      08Ch 4    NDS: Reserved / ARM7 Parameters Table Offset ???  ;base=[038h]
      090h 2    NDS: Reserved / NTR ROM Region End/80000h   ;\usually both same
      092h 2    NDS: Reserved / TWL ROM Region Start/80000h ;/(zero for DSiware)

NDS carts (that don't use DSi features, but are manufactured after DSi release) contains these extra entries:

     (012h)1    Unitcode (must be 00h for non-DSi carts)
     (020h)16   Changed ARM9/ARM7 areas (DSi-in-NDS-mode more restricted than NDS)
      088h 4    Unknown (B8h,4Bh,00h,00h) (similar as in DSi carts)
      1BFh 1    Flags (40h=RSA+TwoHMACs, 60h=RSA+ThreeHMACs)
      33Ch 14   HMAC for Icon/Title (only if [1BFh]=60h)      ;as Whitelist Phase 3
      378h 14   HMAC for 160h-byte header and ARM9+ARM7 areas ;as Whitelist Phase 1
      38Ch 14   HMAC for OverlayARM9+NitroFAT (zero if no overlay)      ;as Phase 2
      F80h 128  RSA signature

All other entries at 160h..FFFh are zerofilled in non-DSi carts.
Changed ARM9/ARM7 areas (and new ARM9i/ARM7i areas)
NDS allowed ARM9 or ARM7 to occupy about 3.8MB of main RAM. On DSi this is restriced to 2.5MB for ARM9 and 0.25MB for ARM7, ie. 2.75MB in total, this restriction applies even in NDS-mode, thus making DSi not fully backwards compatible with NDS games (officially licensed NDS titles hopefully don't conflict with that new restriction). In DSi mode, one can additionally load 2.5MB for ARM9i and 1MB for ARM7i, ie. 6.25MB in total for all four areas.
The DSi loading is a bit complicated, the areas are first loaded to DEDICATED areas:

      ARM9  2004000h..227FFFFh (siz=27C000h) (for NDS mode: 2000000h and up)
      ARM7  2380000h..23BFFFFh (siz=40000h)
      ARM9i 2400000h..267FFFFh (siz=280000h)
      ARM7i 2E80000h..2F87FFFh (siz=108000h)

If the cart header does match with those DEDICATED areas then the data is left in place, otherwise it gets relocated to GENERAL areas (shortly before jumping to the entrypoint). The GENERAL areas are allowed to be:

      Main  2000000h..2FFC000h (excluding bootstrap at 23FEE00h..23FF000h)
      WRAM  3000000h..380F000h (excluding bootstrap at 3FFF600h..3FFF800h)

The GENERAL areas may not overlap with another DEDICATED area (eg. ARM7 cannot be relocated to the ARM9+ARM9i+ARM7i areas). Concerning the 16K at 2000000h..2003FFFh: ARM7+ARM9i+ARM7i aren't allow to use that, but ARM9 seems to be relocatable to that address (usually that shouldn't be done as it would destroy some DSi system variables).
ARM9i+ARM7i areas can have "Size" and "ROM offset" set to zero (but still need to have a valid nonzero "RAM Load address").
ARM9/ARM7 entrypoints MUST be within ARM9/ARM7 area respectively (NDS allowed entrypoints being anywhere).
New DSi Header Entries

      180h 20   Global MBK1..MBK5 Setting, WRAM Slots
      194h 12   Local ARM9 MBK6..MBK8 Setting, WRAM Areas
      1A0h 12   Local ARM7 MBK6..MBK8 Setting, WRAM Areas
      1ACh 3    Global MBK9 Setting, WRAM Slot Write Protect
      1AFh 1    Global WRAMCNT Setting (usually 03h) (FCh/00h in SysMenu/Settings)
      1B0h 4    Region flags (bit0=JPN, bit1=USA, bit2=EUR, bit3=AUS, bit4=CHN,
                  bit5=KOR, bit6-31=Reserved) (FFFFFFFFh=Region Free)
      1B4h 4    Access control (AES Key Select)
                  bit0 Common Client Key ;want 380F000h=3FFC600h+00h "common key"
                  bit1 AES Slot B  ;380F010h=3FFC400h+180h and KEY1=unchanged
                  bit2 AES Slot C  ;380F020h=3FFC400h+190h and KEY2.Y=3FFC400h+1A0h
                  bit3 SD Card            ;want Device I
                  bit4 NAND Access        ;want Device A-H and KEY3=intact
                  bit5 Game Card Power On                 ;tested with bit8
                  bit6 Shared2 File                       ;used... but WHAT for?
                  bit7 Sign JPEG For Launcher (AES Slot B);select 1 of 2 jpeg keys?
                  bit8 Game Card NTR Mode                 ;tested with bit5
                  bit9 SSL Client Cert (AES Slot A) ;KEY0=3FFC600h+30h (twl-*.der)
                  bit10 Sign JPEG For User (AES Slot B) ;\
                  bit11 Photo Read Access               ; seems to be unused
                  bit12 Photo Write Access              ; (and, usually ZERO,
                  bit13 SD Card Read Access             ; even if the stuff is
                  bit14 SD Card Write Access            ; accessed)
                  bit15 Game Card Save Read Access      ; (bit11 set in flipnote)
                  bit16 Game Card Save Write Access     ;/
                  bit31 Debugger Common Client Key  ;want 380F000h=3FFC600h+10h
      1B8h 4    ARM7 SCFG_EXT7 setting (bit0,1,2,10,18,31)
      1BCh 3    Reserved/flags? (zerofilled)
      1BFh 1    Flags (usually 01h) (DSiware Browser: 0Bh)
                  bit0: TSC Touchscreen/Sound Controller Mode (0=NDS, 1=DSi)
                  bit1: Require EULA Agreement
                  bit2: Custom Icon  (0=No/Normal, 1=Use banner.sav)
                  bit3: Show Nintendo Wi-Fi Connection icon in Launcher
                  bit4: Show DS Wireless icon in Launcher
                  bit5: NDS cart with icon SHA1  (DSi firmware v1.4 and up)
                  bit6: NDS cart with header RSA (DSi firmware v1.0 and up)
                  bit7: Developer App
      1C0h 4    ARM9i ROM Offset (usually XX03000h, XX=1MB-boundary after NDS area)
      1C4h 4    Reserved (zero)
      1C8h 4    ARM9i RAM Load address
      1CCh 4    ARM9i Size
      1D0h 4    ARM7i ROM Offset
      1D4h 4    SD/MMC Device List ARM7 RAM Addr; 400h-byte initialized by firmware
      1D8h 4    ARM7i RAM Load address
      1DCh 4    ARM7i Size
      1E0h 4    Digest NTR region offset (usually same as ARM9 rom offs, 0004000h)
      1E4h 4    Digest NTR region length
      1E8h 4    Digest TWL region offset (usually same as ARM9i rom offs, XX03000h)
      1ECh 4    Digest TWL region length
      1F0h 4    Digest Sector Hashtable offset ;\SHA1-HMAC's on all sectors
      1F4h 4    Digest Sector Hashtable length ;/in above NTR+TWL regions
      1F8h 4    Digest Block Hashtable offset  ;\SHA1-HMAC's on each N entries
      1FCh 4    Digest Block Hashtable length  ;/in above Sector Hashtable
      200h 4    Digest Sector size       (eg. 400h bytes per sector)
      204h 4    Digest Block sectorcount (eg. 20h sectors per block)
      208h 4    Icon/Title size (usually 23C0h for DSi) (older 840h-byte works too)
      20Ch 1    SD/MMC size of "shared2\0000" file in 32Kbyte units? (dsi sound)
      20Dh 1    SD/MMC size of "shared2\0001" file in 32Kbyte units?
                    ;or are shared2 sizes rather counted in 16Kbyte cluster units?
      20Eh 1    EULA Version (01h)  ?                                     !
      20Fh 1    Use Ratings  (00h)  ?                                     !
      210h 4    Total Used ROM size, INCLUDING DSi area (optional, can be 0)
      214h 1    SD/MMC size of "shared2\0002" file in 32Kbyte units?
      215h 1    SD/MMC size of "shared2\0003" file in 32Kbyte units?
      216h 1    SD/MMC size of "shared2\0004" file in 32Kbyte units?
      217h 1    SD/MMC size of "shared2\0005" file in 32Kbyte units?
      218h 4    ARM9i Parameters Table Offset (84 D0 04 00) ???  ;base=[028h]
      21Ch 4    ARM7i Parameters Table Offset (2C 05 00 00) ???  ;base=[038h]
      220h 4    Modcrypt area 1 offset ;usually same as ARM9i rom offs (XX03000h)
      224h 4    Modcrypt area 1 size   ;usually min(4000h,ARM9iSize+Fh AND not Fh)
      228h 4    Modcrypt area 2 offset (0=None)
      22Ch 4    Modcrypt area 2 size   (0=None)
      230h 4    Title ID, Emagcode (aka Gamecode spelled backwards)
      234h 1    Title ID, Filetype (00h=Cartridge, 04h=DSiware, 05h=System Fun
                  Tools, [0Fh=Non-executable datafile without cart header],
                  15h=System Base Tools, 17h=System Menu)
      235h 1    Title ID, Zero     (00h=Normal)
      236h 1    Title ID, Three    (03h=DSi) (as opposed to Wii or 3DS)
      237h 1    Title ID, Zero     (00h=Normal)
      238h 4    SD/MMC (DSiware) "public.sav" filesize in bytes  (0=none)
      23Ch 4    SD/MMC (DSiware) "private.sav" filesize in bytes (0=none)
      240h 176  Reserved (zero-filled)

Parental Control Age Ratings (set all entries to 80h to allow any age)

      2F0h 10h  Parental Control Age Ratings (for different countries/areas)
                 Bit7: Rating exists for local country/area
                 Bit6: Game is prohibited in local country/area?
                 Bit5: Unused
                 Bit4-0: Age rating for local country/area (years)
      2F0h 1    CERO (Japan)       (0=None/A, 12=B, 15=C, 17=D, 18=Z)
      2F1h 1    ESRB (US/Canada)   (0=None, 3=EC, 6=E, 10=E10+, 13=T, 17=M)
      2F2h 1    Reserved           (0=None)
      2F3h 1    USK (Germany)      (0=None, 6=6+, 12=12+, 16=16+, 18=18+)
      2F4h 1    PEGI (Pan-Europe)  (0=None, 3=3+, 7=7+, 12=12+, 16=16+, 18=18+)
      2F5h 1    Reserved           (0=None)
      2F6h 1    PEGI (Portugal)    (0=None, 4=4+, 6=6+, 12=12+, 16=16+, 18=18+)
      2F7h 1    PEGI and BBFC (UK) (0=None, 3, 4=4+/U, 7, 8=8+/PG, 12, 15, 16, 18)
      2F8h 1    AGCB (Australia)   (0=None/G, 7=PG, 14=M, 15=MA15+, plus 18=R18+?)
      2F9h 1    GRB (South Korea)  (0=None, 12=12+, 15=15+, 18=18+)  (aka "BG"?)
      2FAh 6    Reserved (6x)      (0=None)
      ?    ?    OFLC (NZ) (unknown, exists in DSi System Settings rom:layout\cmn)
      N/A? -    DEJUS (Brazil) (L, 10, 12, 14, 16, 18)
      N/A? -    GSRMR (Taiwan) (formerly CSRR) (0,6,12,18) (and GSRMR: 15)
      N/A? -    PEGI (Finland) (discontinued 2007, shortly before DSi launch)
                 bit0-4 Rating (0..18)
                 bit6   Pending
                 bit7   Enabled

SHA1-HMAC's and RSA-SHA1

      300h 20   SHA1-HMAC hash ARM9 (with encrypted secure area)     ;[020h,02Ch]
      314h 20   SHA1-HMAC hash ARM7                                  ;[030h,03Ch]
      328h 20   SHA1-HMAC hash Digest master                         ;[1F8h,1FCh]
      33Ch 20   SHA1-HMAC hash Icon/Title (also in newer NDS titles) ;[068h,208h]
      350h 20   SHA1-HMAC hash ARM9i (decrypted)                     ;[1C0h,1CCh]
      364h 20   SHA1-HMAC hash ARM7i (decrypted)                     ;[1D0h,1DCh]
      378h 20   Reserved (zero-filled) (but used for non-whitelisted NDS titles)
      38Ch 20   Reserved (zero-filled) (but used for non-whitelisted NDS titles)
      3A0h 20   SHA1-HMAC hash ARM9 (without 16Kbyte secure area)    ;[020h,02Ch]
      3B4h 2636 Reserved (zero-filled)
      E00h 180h Reserved and unchecked region, always zero. Used for passing
                  arguments in debug environment.
      F80h 80h  RSA-SHA1 signature across header entries [000h..DFFh]

Reserved Area

      1000h..3FFFh  Non-Load area in ROMs... but contains sth in DSiWare files!?!

DSiware/System Utilities
Files saved on SD card or internal eMMC memory are having the same header as ROM carts, with some differences:

      No need for NDS backwards compatibility (since DSiware is DSi only)
      Entry 3A0h can be zero-filled (in LAUNCHER)

DSiware files are usually marked as [012h]=03h=DSi (exceptions are the DS Download Play and PictoChat utilities, which are marked [012h]=00h=NDS, since they are actually running in NDS mode (yet having at least two DSi-specific features: 1st is allowing to reboot into DSi menu via Powerman SPI, 2nd is requiring enabled wifi channels in 2FFFCFAh)).
SHA1-HMAC
The SHA1-HMAC's in cart header and Digest tables are SHA1 checksums with a 40h-byte HMAC key (values 21h, 06h, C0h, DEh, BAh, ..., 24h), the key is contained in the Launcher, and it's also stored in most DSi cartridges (probably used for verifying Digest values when loading additional data after booting). The key can be used for verifying checksums, but (due to the RSA signature) not for changing them. See BIOS chapter for SHA1/HMAC pseudo code.
RSA-SHA1
The RSA-SHA1 value is a normal SHA1 (not SHA1-HMAC) across header entries [000h..DFFh], the 20-byte value is padded to 127-byte size (01h, 105xFFh, 00h, followed by the 20 SHA1 bytes). It can be decrypted (via SWI 22h) using the 80h-byte RSA public keys located in ARM9BIOS (note that there are at least four different RSA keys, one is used for games, and others for system files), and can be then verfied against the SHA1 checksum (computed via SWI 27h).
BIOS RSA Functions (DSi only)
The private key needed for encryption is unknown, which is unfortunately preventing to boot unlicensed (homebrew) software.
Modcrypt (AES-CTR) (optional, carthdr[220h..22Fh] can be all zero)
Modcrypt is a new additional way of encrypting parts of the NDS ROM executable binary modules using AES CTR. It is mostly being used to encrypt the ARM9i and ARM7i binaries. DSi cartridges are usually having only the ARM9i binary encrypted (as area 1), while NAND based applications have both the ARM9i and ARM7i binaries encrypted (as area 1 and 2).
The initial AES Counter value (IV) is:

      Modcrypt Area 1 IV[0..F]: First 16 bytes of the ARM9 SHA1-HMAC   [300h..30Fh]
      Modcrypt Area 2 IV[0..F]: First 16 bytes of the ARM7 SHA1-HMAC   [314h..323h]

The AES key depends of flags in the cartridge header:

     IF header[01Ch].Bit1=0
      None (modcrypt disabled)
     ELSEIF header[01Ch].Bit2 OR header[1BFh].Bit7 THEN (probably for prototypes)
      Debug KEY[0..F]: First 16 bytes of the header                    [000h..00Fh]
     ELSE (commonly used for retail software)
      Retail KEY_X[0..7]: Fixed 8-byte ASCII string                    ("Nintendo")
      Retail KEY_X[8..B]: The 4-byte gamecode, forwards                [00Ch..00Fh]
      Retail KEY_X[C..F]: The 4-byte gamecode, backwards               [00Fh..00Ch]
      Retail KEY_Y[0..F]: First 16 bytes of the ARM9i SHA1-HMAC        [350h..35Fh]

Above does describe how modcrypted areas should look like. However, there are several circumstances where the firmware can't actually decrypt that areas...
Theoretically, the modcrypt areas can span over any of the ARM9i/ARM7i and ARM9/ARM7 areas (in practice, cartridges should never use modcrypt for the ARM9/ARM7 areas because NDS consoles would leave them undecrypted; that restriction doesn't apply to DSiware though).
Theoretically, a large modcrypt area could contain several data areas, but the launcher does decrypt only the first matching data area (areas are processed in order ARM9, ARM7, ARM9i, ARM7i). Moreover, matching data areas must be INSIDE of the modcrypt area (ie. the data area must be same size, or smaller than the modrypt area) (whereas, the launcher is weirdly rounding-up the data size to a multiple of 20h-bytes when checking that matches) (as a side-effect, each data area can be decrypted starting with "IV+0", rather than needing "IV+(offset_within_modcrypt_area/10h").
Theoretically, AES decryption could be done byte-wise, however, the AES hardware is doing it in 10h-byte chunks, unknown if the launcher does require 10h-byte alignments; however, in fact, the launcher seems to be rounding the modcrypt END address to 20h-byte boundary - so it's safest to stick with 20h-byte aligned start+size values for modcrypt areas, as well as for corresponding data areas.
Note: The size of the modcrypt areas can exceed the AES hardware's size limit of max FFFF0h bytes (eg. in DSi Sound utility), in such cases decryption must be split to smaller AES chunks; with manually increased IV.
Modcrypt area 1 and 2 can overlap each other (whereas, it doesn't matter which of them is processed first, since the encryption/decryption is done by XORing).
Note: The ARM9 code for modcrypt/data areas is at 26A6BB8h in Launcher v1.4E.
Digests (optional, carthdr[1E0h..207h] can be all zero)
The NDS format has been extended with a hash tree to verify the entire contents of an NDS ROM. The NDS ROM is divided into sectors, and each sector will be hashed and have its hash stored in the digest sector hashtable. The size of a sector is defined in the header aswell. Furthermore, the sector hashtable is partitioned and hashed again to form block hashes. This block hashtable is hashed again into a single hash called the digest master hash. These hashtables can be used to verify that the sectors of a NDS ROM have not been tampered with, since the integrity of a sector hash can be verified by a block hash, which in turn can be verified by the master hash. And this hash is part of the header, which is signed with RSA.
The sector hashtable reaches over the NTR and TWL regions, respectively.
Cartridge Protocol
The DSi cartridge protocol is same as on NDS; with one new command (3Dh) for unlocking DSi specific memory regions. For details,
DS Cartridge Protocol

DSi Touchscreen/Sound Controller

DSi Touchscreen Access
DSi Touchscreen/Sound Init Flowcharts
AIC3000D Registers
DSi TSC, Register Summary
DSi TSC[0:00h..1Ah], Basic PLL and Timing Control
DSi TSC[0:1Bh..23h], Codec Control
DSi TSC[0:24h..32h], Status and Interrupt Flags
DSi TSC[0:33h..3Bh], Pin Control
DSi TSC[0:3Ch..55h], DAC/ADC and Beep
DSi TSC[0:56h..7Fh], AGC and ADC
DSi TSC[1:xxh], DAC and ADC Routing, PGA, Power-Controls and MISC Logic
DSi TSC[3:xxh], Touchscreen/SAR Control and TSC[FCh:xxh], Buffer
DSi TSC[04h..05h:xxh], ADC Digital Filter Coefficient RAM
DSi TSC[08h..0Fh:xxh], DAC Digital Filter Coefficient RAM
DSi TSC[20h..2Bh:xxh], TSC[40h..5Fh:xxh] ADC/DAC Instruction RAM

DSi Touchscreen Access

The Touch Screen Controller (for lower LCD screen) is accessed via SPI bus,
DS Serial Peripheral Interface Bus (SPI)
so far, it's same as on NDS, but the SPI touchscreen commands are having an entirely different format in DSi mode:
The DSi touchscreen registers are selected via a combination of a PAGE byte and an INDEX byte. The PAGE byte is located at INDEX=00h, and it does somewhat 'bankswitch' the contents of INDEX=01h..7Fh. And INDEX can be incremented manually, or automatically (but, confusingly, the manual increment doesn't work for reading Y coordinates).
SPI clock should be set to 4MHz for DSi Mode touchscreen access (unlike NDS, which used 2MHz). The PENIRQ bit in port 4000136h is always zero in DSi mode.
When reading data: Write dummy 00h-bytes in output direction.
AIC3000D
DSi Touchscreen PAGE:INDEX values
The INDEX/Direction byte is written as first byte after SPI chip select:

      0     Direction for following data bytes (0=Write, 1=Read)
      1-7   INDEX (00h..7Fh) for following data bytes (auto-increasing)

However, the chip has more than 128 registers, stored in multiple pages.

      TSC[00h]=PAGE         ;<-- change page (at INDEX=0)
      TSC[PAGE:INDEX]       ;<-- access registers in select page

Pen Down Testing

      if (TSC[3:09h] AND 40h)<>0 then return(not_pressed)   ;ADC Ready Flag
      if (TSC[3:0Eh] AND 03h)<>0 then return(not_pressed)   ;Undocumented Flags?
      return(pressed)

Note: On NDS, this would be done by reading port 4000136h.bit6, which isn't supported in DSi mode.
X/Y Coordinate Reading

      touchdata[0..19] = TSC[FCh:01h..14h]     ;read page FCh, index(1..20)
      rawx=0, rawy=0
      for i=0 to 8 step 2
        x = touchdata[i+0]*100h+touchdata[i+1]
        y = touchdata[i+10]*100h+touchdata[i+11]
        if (x or y) and F000h then return(not_pressed)
        rawx=rawx+x, rawy=rawy+y
      return(rawx/5, rawy/5)

The resulting 12bit coordinates are same as on NDS (ie. they need to be further processed using the Calibration Points from User Settings).
Touchscreen X/Y Coordinates

      0-11   Coordinate (0..FFFh) (usually 000h when not pressed)
      12-14  State (0=Pressed, 7=Released) (or sometimes also 1 or 3=Released)
      15     State Changed (0=No, 1=Newly pressed/released; cleared after read)

Bit12-14 are usually set to 7 when releasing the screen (though sometimes they become 1 or 3 when releasing the screen, and do stay so until newly pressing it).
Bit15 is cleared after reading (so it will be usually seen only in the first MSB, ie. at INDEX=01h) (though maybe it can also occur elsewhere if it becomes newly set during the SPI transfer).
Microphone
The microphone input was part of the TSC on NDS. In DSi mode it is reportedly somehow changed, using a new "CODEC" (whatever that means). Maybe it's accessed directly via an ARM7 port (and/or TEAK port?), instead of via SPI bus?
NDS Backwards Compatibility Mode
The DSi hardware can emulate the NDS-style touchscreen protocol (with X/Y/MIC channels and with additional PENIRQ flag; but without Pressure or Temperature channels).
DS Touch Screen Controller (TSC)
DSi enhanced games should implement both modes, and use the new mode on DSi consoles, and the old mode on NDS consoles (alternately, CartHdr[1BFh].bit0=0 will activate the old mode for both NDS+DSi).
Unknown how to activate that backwards compatibility mode (might be done via some Touchscreen SPI register, or maybe some Powerman SPI register).
If the backwards compatibility mode isn't enabled, then trying to read the touchscreen in NDS fashion will return nothing but zeroes for all TSC channels (and also zero for the PENIRQ bit).

DSi Touchscreen/Sound Init Flowcharts

touch_enable_tsc_init_list:

      TSC[3:0Eh]=00h  ;Undoc (RMW: bit7=0)
      TSC[3:02h]=18h  ;SAR ADC clk divider, Div8 (12bit mode) (RMW bit34=3, bit7=?)
      TSC[3:0Fh]=A0h  ;Scan Mode Timer
      TSC[3:0Eh].28h  ;Undoc (RNW: bit345=5)
      TSC[3:0Eh].28h  ;Undoc (RMW: bit6=0)
      TSC[3:03h]=87h  ;SAR ADC Control 2 (SelfByPenDown, ScanXY, /PENIRQ)
      TSC[3:05h].04h  ;Stabilization time = 30us (RMW bit012=4)
      TSC[3:04h].02h  ;Sense time = 3us          (RMW bit012=2)
      TSC[3:04h].22h  ;Precharge time = 3us      (RMW bit456=2)
      TSC[3:12h].00h  ;Debounce Time = 0us       (RMW bit012=0)
      TSC[3:0Eh].A8h  ;Undoc                     (RMW bit7=1)

mic_enable_tsc_init_list:
This is needed to unmute the microphone (otherwise microphone will return only 0000h or FFFFh.

      TSC[1:2Eh]=03h  ;MICBIAS=AVDD
      TSC[0:51h]=80h  ;ADC Digital Mic, on
      TSC[0:52h]=00h  ;ADC Digital Volume Control Fine Adjust, unmute
      TSC[1:2Fh]=37h  ;MIC PGA=27.5dB (or use other value, if desired)

mic_disable_tsc_init_list:

      TSC[0:52h]=80h  ;ADC Digital Volume Control Fine Adjust, mute
      TSC[0:51h]=00h  ;ADC Digital Mic, off
      TSC[1:2Eh]=00h  ;MICBIAS=Off

basic_tsc_init_list:
This is done by DSi Launcher/Unlaunch (and other titles usually won't need to do this.

      TSC[0:01h]=01h  ;Software Reset
      TSC[0:39h]=66h  ;ADC DC Measurement 1
      TSC[1:20h]=16h  ;Class-D Speaker Amplifier (RMW:bit4=1)
      TSC[0:04h]=00h  ;Clock-Gen Muxing
      TSC[0:12h]=81h  ;ADC NADC Value
      TSC[0:13h]=82h  ;ADC MADC Value
      TSC[0:51h]=82h  ;ADC Digital Mic
      TSC[0:51h]=00h  ;ADC Digital Mic again
      TSC[0:04h]=03h  ;Clock-Gen Muxing
      TSC[0:05h]=A1h  ;PLL P and R-Values
      TSC[0:06h]=15h  ;PLL J-Value
      TSC[0:0Bh]=87h  ;DAC NDAC Value
      TSC[0:0Ch]=83h  ;DAC MDAC Value
      TSC[0:12h]=87h  ;ADC NADC Value
      TSC[0:13h]=83h  ;ADC MADC Value
      TSC[3:10h]=88h  ;Scan Mode Timer Clock (RMW:bit0-6)
      TSC[4:08h..0Dh]=7Fh,E1h,80h,1Fh,7Fh,C1h  ;some coeff's
      TSC[0:41h]=08h  ;DAC Left Volume Control
      TSC[0:42h]=08h  ;DAC Right Volume Control
      TSC[0:3Ah]=00h  ;GPI3 Pin Control
      TSC[4:08h..0Dh]=7Fh,E1h,80h,1Fh,7Fh,C1h  ;some coeff's ;again?
      TSC[1:2Fh]=2Bh  ;MIC PGA
      TSC[1:30h]=40h  ;P-Terminal Delta-Sigma Mono ADC Channel Fine-Gain Input
      TSC[1:31h]=40h  ;M-Terminal ADC Input Selection
      TSC[1:32h]=60h  ;Input CM Settings
      TSC[0:74h]=82h  ;VOL/MICDET-Pin SAR ADC - Volume Control (RMW)
      TSC[0:74h]=92h  ;VOL/MICDET-Pin SAR ADC - Volume Control (RMW)
      TSC[0:74h]=D2h  ;VOL/MICDET-Pin SAR ADC - Volume Control (RMW)
      TSC[1:21h]=20h  ;HP Output Drivers POP Removal Settings
      TSC[1:22h]=F0h  ;Output Driver PGA Ramp-Down Period Control
      TSC[0:3Fh]=D4h  ;DAC Data-Path Setup (RMW)
      TSC[1:23h]=44h  ;DAC_L and DAC_R Output Mixer Routing
      TSC[1:1Fh]=D4h  ;Headphone Drivers
      TSC[1:28h]=4Eh  ;HPL Driver (Left Headphone)
      TSC[1:29h]=4Eh  ;HPR Driver (Right Headphone)
      TSC[1:24h]=9Eh  ;Analog Volume to HPL (Left Headphone)
      TSC[1:25h]=9Eh  ;Analog Volume to HPR (Right Headphone)
      TSC[1:20h]=D4h  ;Class-D Speaker Amplifier
      TSC[1:2Ah]=14h  ;SPL Driver (Left Speaker)
      TSC[1:2Bh]=14h  ;SPR Driver (Right Speaker)
      TSC[1:26h]=A7h  ;Analog Volume to SPL (Left Speaker)
      TSC[1:27h]=A7h  ;Analog Volume to SPR (Right Speaker)
      TSC[0:40h]=00h  ;DAC Volume Control
      (should set DSi.GPIO.data.bit7 here, but can be also done elsewhere)
      TSC[0:3Ah]=60h  ;GPI3 Pin Control

nds_mode_tsc_init_list:
Switches to NDS Touchscreen/sound mode. Usually done when starting NDS titles (or DSi titles that request NDS-TSC mode in carthdr[1BFh]).

      TSC[1:26h]=ACh  ;\special setting (when found special gamecode)
      TSC[1:27h]=ACh  ;/
      TSC[1:26h]=A7h  ;\normal setting (for any other gamecodes)
      TSC[1:27h]=A7h  ;/
      TSC[1:2Eh]=03h  ;MICBIAS=AVDD
      TSC[3:03h]=00h  ;SAR ADC Control 2
      TSC[1:21h]=20h  ;HP Output Drivers POP Removal Settings
      TSC[1:22h]=F0h  ;Output Driver PGA Ramp-Down Period Control (70h OR 80h)
      TSC[1:22h]=70h  ;Output Driver PGA Ramp-Down Period Control (bit7=0)
      TSC[0:52h]=80h  ;ADC Digital Volume Control Fine Adjust
      TSC[0:51h]=00h  ;ADC Digital Mic
      READ[3:02h] (returns 00h)
      TSC[3:02h].Bit7=1 ;SAR ADC Control 1 (set to 80h) (or 98h?) (RMW)
      TSC[FFh:05h]=00h ;TSC final enter NDS mode

And, set powerman[0].bit0=1 (bit0=sound amplifier on) (this is actually part of TSC chip, accessed via "POWERMAN" SPI chipselect signal).

DSi TSC, Register Summary

The DSi's Touchscreen/Sound controller (AIC3000D) is essentially a Texas Instruments TSC2117 chip (possibly with some customizations for NDS backwards compatibility mode).
TSC[page:index] registers are accessed via SPI bus with 15bit address space:

      7bit index: selected via the first SPI byte, with direction flag in bit0
      8bit page:  selected by writing to index 00h, ie. to TSC[xxh:00h]

TSC page select (for "TSC[page:index]" addressing)

      TSC[xxh:00h] - Page Select Register (00h)

TSC Basic PLL and Timing Control

      TSC[0:01h] - Software Reset (00h)
      TSC[0:02h] - Reserved (xxh) (R)
      TSC[0:03h] - Overtemperature OT Flag (02h..FFh) (R)
      TSC[0:04h] - Clock-Gen Muxing (00h)
      TSC[0:05h] - PLL P and R-Values (11h)
      TSC[0:06h] - PLL J-Value (04h)
      TSC[0:07h,08h] - PLL D-Value MSB,LSB (0000h)
      TSC[0:09h,0Ah] - Reserved (xxh)
      TSC[0:0Bh] - DAC NDAC Value (01h)
      TSC[0:0Ch] - DAC MDAC Value (01h)
      TSC[0:0Dh,0Eh] - DAC DOSR Value MSB,LSB (0080h)
      TSC[0:0Fh] - DAC IDAC Value (80h)
      TSC[0:10h] - DAC miniDSP Engine Interpolation (08h)
      TSC[0:11h] - Reserved (xxh)
      TSC[0:12h] - ADC NADC Value (01h)
      TSC[0:13h] - ADC MADC Value (01h)
      TSC[0:14h] - ADC AOSR Value (80h)
      TSC[0:15h] - ADC IADC Value (80h)
      TSC[0:16h] - ADC miniDSP Engine Decimation (04h)
      TSC[0:17h,18h] - Reserved (xxh)
      TSC[0:19h] - CLKOUT MUX (00h)
      TSC[0:1Ah] - CLKOUT Divider M Value (01h)

TSC Codec Control

      TSC[0:1Bh] - Codec Interface Control 1 (00h) (R/W)
      TSC[0:1Ch] - Data-Slot Offset Programmability (00h)
      TSC[0:1Dh] - Codec Interface Control 2 (00h)
      TSC[0:1Eh] - BCLK Divider N Value (01h)
      TSC[0:1Fh] - Codec Secondary Interface Control 1 (00h)
      TSC[0:20h] - Codec Secondary Interface Control 2 (00h)
      TSC[0:21h] - Codec Secondary Interface Control 3 (00h)
      TSC[0:22h] - I2C Bus Condition (00h)
      TSC[0:23h] - Reserved (xxh)

TSC Status and Interrupt Flags

      TSC[0:24h] - ADC Flag Register (0xh) (R)
      TSC[0:25h] - DAC Flag Register (00h) (R)
      TSC[0:26h] - DAC Flag Register (00h) (R)
      TSC[0:27h] - Overflow Flags (00h) (R)
      TSC[0:28h..2Bh] - Reserved (xxh)
      TSC[0:2Ch] - Interrupt Flags DAC, sticky (00h..30h) (R)
      TSC[0:2Dh] - Interrupt Flags ADC, sticky (00h..18h) (R)
      TSC[0:2Eh] - Interrupt Flags DAC, non-sticky? (00h..30h) (R)
      TSC[0:2Fh] - Interrupt Flags ADC, non-sticky? (00h..18h) (R)
      TSC[0:30h] - INT1 Control Register (Select INT1 Sources) (00h)
      TSC[0:31h] - INT2 Control Register (Select INT2 Sources) (00h)
      TSC[0:32h] - INT1 and INT2 Control Register (00h)

TSC Pin Control

      TSC[0:33h] - GPIO1 In/Out Pin Control (00h..C2h)
      TSC[0:34h] - GPIO2 In/Out Pin Control (00h..C2h)
      TSC[0:35h] - SDOUT (OUT Pin) Control (12h)
      TSC[0:36h] - SDIN (IN Pin) Control (02h or 03h)
      TSC[0:37h] - MISO (OUT Pin) Control (02h)
      TSC[0:38h] - SCLK (IN Pin) Control (02h..03h)
      TSC[0:39h] - GPI1 and GPI2 Pin Control (00h..11h)
      TSC[0:3Ah] - GPI3 Pin Control (00h..10h)
      TSC[0:3Bh] - Reserved (xxh)

TSC DAC/ADC and Beep

      TSC[0:3Ch] - DAC Instruction Set (01h)
      TSC[0:3Dh] - ADC Instruction Set (04h)
      TSC[0:3Eh] - Programmable Instruction Mode-Control Bits (00h)
      TSC[0:3Fh] - DAC Data-Path Setup (14h)
      TSC[0:40h] - DAC Volume Control (0Ch)
      TSC[0:41h] - DAC Left Volume Control (00h)
      TSC[0:42h] - DAC Right Volume Control (00h)
      TSC[0:43h] - Headset Detection (00h..60h)
      TSC[0:44h] - DRC Control 1 (0Fh)
      TSC[0:45h] - DRC Control 2 (38h)
      TSC[0:46h] - DRC Control 3 (00h)
      TSC[0:47h] - Beep Generator and Left Beep Volume (00h)
      TSC[0:48h] - Beep Generator and Right Beep Volume (00h)
      TSC[0:49h,4Ah,4Bh] - Beep Length MSB,MID,LSB (0000EEh)
      TSC[0:4Ch,4Dh] - Beep Frequency Sin(x) MSB,LSB (10D8h)
      TSC[0:4Eh,4Fh] - Beep Frequency Cos(x) MSB,LSB (7EE3h)
      TSC[0:50h] - Reserved (xxh)
      TSC[0:51h] - ADC Digital Mic (00h)
      TSC[0:52h] - ADC Digital Volume Control Fine Adjust (80h)
      TSC[0:53h] - ADC Digital Volume Control Coarse Adjust (00h)
      TSC[0:54h,55h] - Reserved (xxh)

TSC AGC and ADC (Auto-Gain-Control & Analog-to-Digital Converter)

      TSC[0:56h] - AGC Control 1 (00h)
      TSC[0:57h] - AGC Control 2 (00h)
      TSC[0:58h] - AGC Maximum Gain (7Fh, uh that's 7Fh=Reserved?)
      TSC[0:59h] - AGC Attack Time (00h)
      TSC[0:5Ah] - AGC Decay Time (00h)
      TSC[0:5Bh] - AGC Noise Debounce (00h)
      TSC[0:5Ch] - AGC Signal Debounce (00h)
      TSC[0:5Dh] - AGC Gain-Applied Reading (xxh) (R)
      TSC[0:5Eh...65h] - Reserved (xxh)
      TSC[0:66h] - ADC DC Measurement 1 (00h)
      TSC[0:67h] - ADC DC Measurement 2 (00h)
      TSC[0:68h,69h,6Ah] - ADC DC Measurement Output MSB,MID,LSB (R) (000000h)
      TSC[0:6Bh...73h] - Reserved (xxh)
      TSC[0:74h] - VOL/MICDET-Pin SAR ADC - Volume Control (00h)
      TSC[0:75h] - VOL/MICDET-Pin Gain (xxh) (R)
      TSC[0:76h...7Fh] - Reserved (xxh)

TSC TSC, DAC and ADC Routing, PGA, Power-Controls and MISC Logic

      TSC[1:01h..1Dh] - Reserved (xxh)
      TSC[1:1Eh] - Headphone and Speaker Amplifier Error Control (00h)
      TSC[1:1Fh] - Headphone Drivers (04h)
      TSC[1:20h] - Class-D Speaker Amplifier (06h)
      TSC[1:21h] - HP Output Drivers POP Removal Settings (3Eh)
      TSC[1:22h] - Output Driver PGA Ramp-Down Period Control (00h)
      TSC[1:23h] - DAC_L and DAC_R Output Mixer Routing (00h)
      TSC[1:24h] - Analog Volume to HPL (Left Headphone) (7Fh)
      TSC[1:25h] - Analog Volume to HPR (Right Headphone) (7Fh)
      TSC[1:26h] - Analog Volume to SPL (Left Speaker) (7Fh)
      TSC[1:27h] - Analog Volume to SPR (Right Speaker) (7Fh)
      TSC[1:28h] - HPL Driver (Left Headphone) (02h)
      TSC[1:29h] - HPR Driver (Right Headphone) (02h)
      TSC[1:2Ah] - SPL Driver (Left Speaker) (00h)
      TSC[1:2Bh] - SPR Driver (Right Speaker) (00h)
      TSC[1:2Ch] - HP Driver Control (00h)
      TSC[1:2Dh] - Reserved (xxh)
      TSC[1:2Eh] - MICBIAS (00h)
      TSC[1:2Fh] - MIC PGA (80h)
      TSC[1:30h] - P-Terminal Delta-Sigma Mono ADC Channel Fine-Gain Input (00h)
      TSC[1:31h] - M-Terminal ADC Input Selection (00h)
      TSC[1:32h] - Input CM Settings (00h)
      TSC[1:33h..FFh] - Reserved (xxh)

Reserved Page

      TSC[2:01h..FFh] - Reserved (00h)

TSC Touchscreen/SAR Control

      TSC[3:01h] - Reserved (xxh)
      TSC[3:02h] - SAR ADC Control 1 (00h)
      TSC[3:03h] - SAR ADC Control 2 (00h)
      TSC[3:04h] - Precharge and Sense (00h)
      TSC[3:05h] - Panel Voltage Stabilization (00h)
      TSC[3:06h] - Voltage Reference (20h)
      TSC[3:07h,08h] - Reserved (xxh)
      TSC[3:09h] - Status Bits 1 (40h) (R)
      TSC[3:0Ah] - Status Bits 2 (00h) (R)
      TSC[3:0Bh,0Ch] - Reserved (xxh)
      TSC[3:0Dh] - Buffer Mode (03h)  ;DSi: Unused,seems to use TSC[3:0Eh] instead
      TSC[3:0Eh] - Reserved / Undocumented (read by DSi for Pen Down Test) (0Fh)
      TSC[3:0Fh] - Scan Mode Timer (40h)
      TSC[3:10h] - Scan Mode Timer Clock (81h)
      TSC[3:11h] - SAR ADC Clock (81h)
      TSC[3:12h] - Debounce Time for Pen-Up Detection (00h)
      TSC[3:13h] - Auto AUX Measurement Selection (00h)
      TSC[3:14h] - Touch-Screen Pen Down (00h)
      TSC[3:15h] - Threshold Check Flags Register (00h) (R)
      TSC[3:16h,17h] - AUX1 Maximum Value Check MSB,LSB (0000h)
      TSC[3:18h,19h] - AUX1 Minimum Value Check MSB,LSB (0000h)
      TSC[3:1Ah,1Bh] - AUX2 Maximum Value Check MSB,LSB (0000h)
      TSC[3:1Ch,1Dh] - AUX2 Minimum Value Check MSB,LSB (0000h)
      TSC[3:1Eh,1Fh] - Temperature(TEMP1/TEMP2) Maximum Value Check MSB,LSB (0000h)
      TSC[3:20h,21h] - Temperature(TEMP1/TEMP2) Minimum Value Check MSB,LSB (0000h)
      TSC[3:22h...29h] - Reserved (xxh)
      TSC[3:2Ah,2Bh] - Touchscreen X-Coordinate Data MSB,LSB (0000h) (R)
      TSC[3:2Ch,2Dh] - Touchscreen Y-Coordinate Data MSB,LSB (0000h) (R)
      TSC[3:2Eh,2Fh] - Touchscreen Z1-Pressure Register MSB,LSB (0000h) (R)
      TSC[3:30h,31h] - Touchscreen Z2-Pressure Register MSB,LSB (0000h) (R)
      TSC[3:32h...35h] - Reserved (xxh)
      TSC[3:36h,37h] - AUX1 Data MSB,LSB (0000h) (R)
      TSC[3:38h,39h] - AUX2 Data MSB,LSB (0000h) (R)
      TSC[3:3Ah,3Bh] - VBAT Data MSB,LSB (0000h) (R)
      TSC[3:3Ch...41h] - Reserved (xxh)
      TSC[3:42h,43h] - Temperature TEMP1 Data Register MSB,LSB (0000h) (R)
      TSC[3:44h,45h] - Temperature TEMP2 Data Register MSB,LSB (0000h) (R)
      TSC[3:46h...7Fh] - Reserved (xxh)

TSC Coefficient RAM and Instruction RAM for ADC/DAC

      TSC[04h..05h:xxh] - ADC Coefficient RAM (126 x 16bit)
      TSC[06h..07h:xxh] - Reserved (00h)
      TSC[08h:01h]      - DAC Coefficient RAM Control (00h)
      TSC[08h..0Bh:xxh] - DAC Coefficient RAM, DAC Buffer A (252 x 16bit)
      TSC[0Ch..0Fh:xxh] - DAC Coefficient RAM, DAC Buffer B (252 x 16bit)
      TSC[10h..1Fh:xxh] - Reserved (00h)
      TSC[20h..2Bh:xxh] - ADC DSP Engine Instruction RAM (384 x 24bit)
      TSC[2Ch..3Fh:xxh] - Reserved (00h)
      TSC[40h..5Fh:xxh] - DAC DSP Engine Instruction RAM (1024 x 24bit)
      TSC[60h..FBh:xxh] - Reserved (00h)

TSC Additional 3DS Registers (3DS onlly, and only on the 2nd SPI bus)

      TSC[64h:01h..xxh] - 3DS Config Registers for Sound (and Microphone?)
      TSC[65h:01h..xxh] - 3DS Config Registers for Sound (and Microphone?)
      TSC[67h:01h..xxh] - 3DS Config Registers for Touchscreen and Circle Pad
      TSC[FBh:01h..xxh] - 3DS Buffer Mode Data for Touchscreen and Circle Pad

TSC Touchscreen/SAR Buffer

      TSC[FCh:01h..xxh] - Buffer Mode Data MSB,LSB (xxxxh) (R)
      TSC[FCh:xxh..7Fh] - Reserved (xxh)

TSC Undocumented Registers

      TSC[FDh:xxh] - Contains some undocumented non-zero values (DSi specific?)
      TSC[FEh:xxh] - Reserved (00h)
      TSC[FFh:xxh] - Accessing this page changes operation (DSi specific?)

DSi TSC[0:00h..1Ah], Basic PLL and Timing Control

TSC[xxh:00h] - Page Select Register (00h)

      7-0   Page Select (00h..FEh) (FFh=Undocumented, enter special mode?)

Selects the "page" for the TSC[page:index] addresses.
TSC[0:01h] - Software Reset (00h)

      7-1   Reserved. Write only zeros to these bits.
      0     Software Reset (0=No change, 1=Reset)

TSC[0:02h] - Reserved (xxh) (R)

      7-0   Reserved. Do not write to this register.

TSC[0:03h] - Overtemperature OT Flag (02h..FFh) (R)

      7-2   Reserved. Do not write to these bits. (R)
      1     Overtemperature protection flag (0=Alert, 1=Normal) (R)
      0     Reserved. Do not write to these bits. (R/W?)

Bit1 is valid only if speaker amplifier is powered up.
TSC[0:04h] - Clock-Gen Muxing (00h)

      7-4   Reserved. Write only zeros to these bits.
      3-2   Select PLL_CLKIN   (0=MCLK, 1=BCLK, 2=GPIO1, 3=SDIN)
      1-0   Select CODEC_CLKIN (0=MCLK, 1=BCLK, 2=GPIO1, 3=PLL_CLK)

See Section 5.8 for more details on clock generation mutiplexing and dividers.
TSC[0:05h] - PLL P and R-Values (11h)

      7     PLL Enable        (0=Power down, 1=Power up)
      6-4   PLL Divider P     (1..7=Div1..7, or 0=Div8)
      3-0   PLL Multiplier R  (1..15=Mul1..15, or 0=Mul16)

TSC[0:06h] - PLL J-Value (04h)

      7-6   Reserved. Write only zeros to these bits.
      5-0   PLL Multiplier J  (1..63=Mul1..63, or 0=Reserved)

TSC[0:07h,08h] - PLL D-Value MSB,LSB (0000h)

      15-14 Reserved. Write only zeros to these bits.
      13-0  PLL fractional multiplier D-Val (14bit)

Note that LSB register must be written to immediately after writing to MSB.
TSC[0:09h,0Ah] - Reserved (xxh)

      7-0   Reserved. Write only zeros to these bits.

TSC[0:0Bh] - DAC NDAC Value (01h)

      7     DAC NDAC Divider Enable (0=Power down, 1=Power up)
      6-0   DAC NDAC Divider (1..127=Div1..127, or 0=Div128)

TSC[0:0Ch] - DAC MDAC Value (01h)

      7     DAC MDAC Divider Enable (0=Power down, 1=Power up)
      6-0   DAC MDAC Divider (1..127=Div1..127, or 0=Div128)

TSC[0:0Dh,0Eh] - DAC DOSR Value MSB,LSB (0080h)

      15-10 Reserved
      9-0   DAC OSR value "DOSR" (1..1023, or 0=1024)

DOSR should be an integral multiple of the interpolation ratio in TSC[0:10h].
Note that LSB register must be written to immediately after writing to MSB.
TSC[0:0Fh] - DAC IDAC Value (80h)

      7-0   Number of instructions for DAC miniDSP engine (IDAC=N*4)
            (1..255 = 4..1020 (N*4), or 0=1024)

IDAC should be an integral multiple of the interpolation ratio in TSC[0:10h].
TSC[0:10h] - DAC miniDSP Engine Interpolation (08h)

      7-4   Reserved. Do not write to these registers.
      3-0   Interpolation ratio in DAC miniDSP engine (1..15, or 0=16)

TSC[0:11h] - Reserved (xxh)

      7-0   Reserved. Do not write to this register.

TSC[0:12h] - ADC NADC Value (01h)

      7     ADC NADC divider is powered
              0: ADC NADC divider is powered down and ADC_DSP_CLK = DAC_DSP_CLK.
              1: ADC NADC divider is powered up.
      6-0   ADC NADC divider  (1..127, or 0=128)

TSC[0:13h] - ADC MADC Value (01h)

      7     ADC MADC divider is powered
              0: ADC MADC divider is powered down and ADC_MOD_CLK = DAC_MOD_CLK.
              1: ADC MADC divider is powered up.
      6-0   ADC MADC divider  (1..127, or 0=128)

TSC[0:14h] - ADC AOSR Value (80h)

      7-0   ADC OSR "AOSR" divider  (1..255, or 0=256)

AOSR should be an integral multiple of the decimation ratio in TSC[0:16h].
TSC[0:15h] - ADC IADC Value (80h)

      7-0   Number of instruction for ADC miniDSP engine (IADC=N*2)
            (1..192 = 2..384 (N*2), or 0,193..255=Reserved)

IADC should be an integral multiple of the decimation ratio in TSC[0:16h].
TSC[0:16h] - ADC miniDSP Engine Decimation (04h)

      7-4   Reserved
      3-0   Decimation ratio in ADC miniDSP engine  (1..15, or 0=16)

TSC[0:17h,18h] - Reserved (xxh)

      7-0   Reserved. Do not write to these registers.

TSC[0:19h] - CLKOUT MUX (00h)

      7-3   Reserved
      2-0   CDIV_CLKIN (0=MCLK, 1=BCLK, 2=SDIN, 3=PLL_CLK, 4=DAC_CLK(DSP),
            5=DAC_MOD_CLK, 6=ADC_CLK(DSP), 7=ADC_MOD_CLK)

TSC[0:1Ah] - CLKOUT Divider M Value (01h)

      7     CLKOUT divider M Enable (0=Powered down, 1=Powered up)
      6-0   CLKOUT divider M        (1..127, or 0=128)

DSi TSC[0:1Bh..23h], Codec Control

TSC[0:1Bh] - Codec Interface Control 1 (00h) (R/W)

      7-6   Codec interface type        (0=I2S, 1=DSP, 2=RJF, 3=LJF)
      5-4   Codec interface word length (0..3=16,20,24,32 bits)
      3     BCLK Direction              (0=Input, 1=Output)
      2     WCLK Direction              (0=Input, 1=Output)
      1     Reserved
      0     Driving SDOUT to High-Impedance for the Extra BCLK cycle when
             data is not being transferred (0=Disabled, 1=Enabled)

TSC[0:1Ch] - Data-Slot Offset Programmability (00h)

      7-0   Offset (0..255 = 0..255 BCLKs)

Note: Measured with respect to WCLK Rising Edge in DSP Mode.
TSC[0:1Dh] - Codec Interface Control 2 (00h)

      7-6   Reserved
      5     SDIN-to-SDOUT loopback (0=Disable, 1=Enable)
      4     ADC-to-DAC loopback    (0=Disable, 1=Enable)
      3     BCLK Invert            (0=No, 1=Invert)
      2     BCLK and WCLK active even with Codec powered down (0=No, 1=Yes)
      1-0   BDIV_CLKIN     (0=DAC_CLK, 1=DAC_MOD_CLK, 2=ADC_CLK, 3=ADC_MOD_CLK)

The BCLK settings in Bit2,3 do apply to both Primary and Secondary BCLK.
TSC[0:1Eh] - BCLK Divider N Value (01h)

      7     BCLK divider N Enable (0=Powered down, 1=Powered up)
      6-0   BCLK divider N        (1..127, or 0=128)

TSC[0:1Fh] - Codec Secondary Interface Control 1 (00h)

      7-5   Secondary BCLK is obtained from    ;\(0=GPIO1, 1=SCLK, 2=MISO, 3=SDOUT,
      4-2   Secondary WCLK is obtained from    ;/ 4=GPIO2, 5=GPI1, 6=GPI2, 7=GPI3)
      1-0   Secondary SDIN is obtained from (0=GPIO1, 1=SCLK, 2=GPIO2, 3=GPI1)

TSC[0:20h] - Codec Secondary Interface Control 2 (00h)

      7-5   ADC_WCLK is obtained from  (0=GPIO1, 1=SCLK, 2=MISO, 3=Reserved,
      4     Reserved                        4=GPIO2, 5=GPI1, 6=GPI2, 7=GPI3)
      3     Codec/ClockGen BCLK source (0=Primary BCLK, 1=Secondary BCLK)
      2     Codec WCLK source          (0=Primary WCLK, 1=Secondary WCLK)
      1     Codec ADC_WCLK source      (0=DAC_WCLK, 1=ADC_WCLK)
      0     Codec SDIN source          (0=Primary SDIN, 1=Secondary SDIN)

TSC[0:21h] - Codec Secondary Interface Control 3 (00h)

      7     Primary BCLK output   (0=Internally generated BCLK, 1=Secondary BCLK)
      6     Secondary BCLK output (0=Primary BCLK, 1=Internally generated BCLK)
      5-4   Primary WCLK output  (0=DAC_fS, 1=ADC_fS, 2=Secondary WCLK, 3=Reserved)
      3-2   Secondary WCLK output (0=Primary WCLK, 1=DAC_fS, 2=ADC_fS, 3=Reserved)
      1     Primary SDOUT         (0=SDOUT from codec, 1=Secondary SDIN)
      0     Secondary SDOUT       (0=Primary SDIN, 1=SDOUT from codec)

TSC[0:22h] - I2C Bus Condition (00h)

      7-6   Reserved. Write only the reset value to these bits.
      5     Accept I2C general-call address  (0=No/Ignore, 1=Yes/Accept)
      4-0   Reserved. Write only zeros to these bits.

TSC[0:23h] - Reserved (xxh)

      7-0   Reserved. Write only zeros to these bits.

DSi TSC[0:24h..32h], Status and Interrupt Flags

TSC[0:24h] - ADC Flag Register (0xh) (R)

      7     ADC PGA applied gain = programmed gain (0=Differs, 1=Equal) (R)
      6     ADC powered                  (0=Powered down, 1=Powered up) (R)
      5     AGC saturated        (0=No/inrange, 1=Yes/saturated to max) (R)
      4-0   Reserved. Write only zeros to these bits.

Note on D5(?): Sticky flag bIts. These are read-only bits. They are automatically cleared once they are read and are set only if the source trigger occurs again.
TSC[0:25h] - DAC Flag Register (00h) (R)

      7     Left-channel DAC powered             (0=Powered down, 1=Powered up) (R)
      6     Reserved. Write only zero to this bit.
      5     Left Headphone HPL driver powered    (0=Powered down, 1=Powered up) (R)
      4     Left-channel class-D driver powered  (0=Powered down, 1=Powered up) (R)
      3     Right-channel DAC powered            (0=Powered down, 1=Powered up) (R)
      2     Reserved. Write only zero to this bit.
      1     Right Headphone HPR driver powered   (0=Powered down, 1=Powered up) (R)
      0     Right-channel class-D driver powered (0=Powered down, 1=Powered up) (R)

TSC[0:26h] - DAC Flag Register (00h) (R)

      7-5   Reserved. Do not write to these bits.
      4     Left-channel DAC PGA applied gain=programmed gain  (0=Differs, 1=Equal)
      3-1   Reserved. Write only zeros to these bits.
      0     Right-channel DAC PGA applied gain=programmed gain (0=Differs, 1=Equal)

TSC[0:27h] - Overflow Flags (00h) (R)

      7     Left-Channel DAC Overflow Flag           (0=None, 1=Overflow) (R)
      6     Right-Channel DAC Overflow Flag          (0=None, 1=Overflow) (R)
      5     DAC Barrel Shifter Output Overflow Flag  (0=None, 1=Overflow) (R)
      4     Reserved. Write only zeros to these bits.
      3     Delta-Sigma Mono ADC Overflow Flag       (0=None, 1=Overflow) (R)
      2     Reserved. Write only zero to this bit.
      1     ADC Barrel Shifter Output Overflow Flag  (0=None, 1=Overflow) (R)
      0     Reserved. Write only zero to this bit.

Sticky flag bIts. These are read-only bits. They are automatically cleared once they are read and are set only if the source trigger occurs again.
TSC[0:28h..2Bh] - Reserved (xxh)

      7-0   Reserved. Write only the reset value to these bits.

TSC[0:2Ch] - Interrupt Flags DAC, sticky (00h..30h) (R)

      7     Short-circuit detected at HPL/left class-D driver         (0=No, 1=Yes)
      6     Short-circuit detected at HPR/right class-D driver        (0=No, 1=Yes)
      5     Headset button pressed                                    (0=No, 1=Yes)
      4     Headset insertion/removal is detected                     (0=No, 1=Yes)
      3     Left DAC signal power vs signal threshold of DRC (0=Less/Equal,1=Above)
      2     Right DAC signal power vs signal threshold of DRC(0=Less/Equal,1=Above)
      1     DAC miniDSP Engine Standard Interrupt-Port Output  (0=Read 0, 1=Read 1)
      0     DAC miniDSP Engine Auxiliary Interrupt-Port Output (0=Read 0, 1=Read 1)

Sticky flag bIts. These are read-only bits. They are automatically cleared once they are read and are set only if the source trigger occurs again.
TSC[0:2Dh] - Interrupt Flags ADC, sticky (00h..18h) (R)

      7     Reserved. Write only zero to this bit.
      6     ADC signal power vs noise threshold for AGC (0=Greater, 1=Less)
      5     Reserved. Write only zeros to these bits.
      4     ADC miniDSP Engine Standard Interrupt Port Output  (0=Read 0, 1=Read 1)
      3     ADC miniDSP Engine Auxiliary Interrupt Port Output (0=Read 0, 1=Read 1)
      2     DC measurement using Delta Sigma Audio ADC
              (0=Not available, 1=Not available, too, uh?)
      1-0   Reserved. Write only zeros to these bits.

Sticky flag bIts. These are read-only bits. They are automatically cleared once they are read and are set only if the source trigger occurs again.
TSC[0:2Eh] - Interrupt Flags DAC, non-sticky? (00h..30h) (R)

      7     Short circuit detected at HPL/left class-D driver         (0=No, 1=Yes)
      6     Short circuit detected at HPR/right class-D driver        (0=No, 1=Yes)
      5     Headset button pressed                                    (0=No, 1=Yes)
      4     Headset removal/insertion detected             (0=Removal, 1=Insertion)
      3     Left DAC signal power vs signal threshold of DRC     (0=Below, 1=Above)
      2     Right DAC signal power vs signal threshold of DRC    (0=Below, 1=Above)
      1     DAC miniDSP Engine Standard Interrupt Port Output  (0=Read 0, 1=Read 1)
      0     DAC miniDSP Engine Auxiliary Interrupt Port Output (0=Read 0, 1=Read 1)

This is (almost?) same as TSC[0:2Ch]. Maybe this is current state (non-sticky)?
TSC[0:2Fh] - Interrupt Flags ADC, non-sticky? (00h..18h) (R)

      7     Reserved
      6     Delta-sigma mono ADC signal power vs noise threshold for left AGC
      5     Reserved                                       (0=Greater, 1=Less)
      4     ADC miniDSP Engine Standard Interrupt Port Output  (0=Read 0, 1=Read 1)
      3     ADC miniDSP Engine Auxiliary Interrupt Port Output (0=Read 0, 1=Read 1)
      2     DC measurement using Delta Sigma Audio ADC
              (0=Not available, 1=Not available, too, uh?)
      1-0   Reserved. Write only zeros to these bits.

This is (almost?) same as TSC[0:2Dh]. Maybe this is current state (non-sticky)?
TSC[0:30h] - INT1 Control Register (Select INT1 Sources) (00h)
TSC[0:31h] - INT2 Control Register (Select INT2 Sources) (00h)

      7     Headset-insertion detect                                  (0=Off, 1=On)
      6     Button-press detect                                       (0=Off, 1=On)
      5     DAC DRC signal-power                                      (0=Off, 1=On)
      4     ADC AGC noise                                             (0=Off, 1=On)
      3     Short-circuit                                             (0=Off, 1=On)
      2     Engine-generated                                          (0=Off, 1=On)
      1     DC measurement using Delta Sigma Audio ADC data-available (0=Off, 1=On)
      0     INT duration (0=Pulse Once, 1=Pulse Repeatedly until Acknowledge)

Bit1-7 select which sources shall trigger INT1/INT2, a few more sources can be selected in TSC[0:32h].Bit5-7.
Bit0 selects how the INT1/INT2 signal shall be pulsed (once with 2ms length, or repeating every 4ms with 50% duty, until it gets acknowledged by reading TSC[0:2Ch,2Dh,32h]).
TSC[0:32h] - INT1 and INT2 Control Register (00h)

      7     INT1 upon SAR measurement data-out-of-threshold range   (0=Off, 1=Off?)
      6     INT1 upon Pen touch/SAR data-available                    (0=Off, 1=On)
      5     INT2 upon SAR measurement data-out-of-threshold range   (0=Off, 1=Off?)
      4     Reserved
      3     Pen touch detected                          (0=No, 1=Touch)     (R)
      2     Data available for read                     (0=No, 1=Available) (R)
      1     SAR data out of programmed threshold range  (0=No, 1=Out)       (R)
      0     Reserved. Write only the default value to this bit.             (R)

DSi TSC[0:33h..3Bh], Pin Control

TSC[0:33h] - GPIO1 In/Out Pin Control (00h..C2h)
TSC[0:34h] - GPIO2 In/Out Pin Control (00h..C2h)

      7-6   Reserved. Do not write any value other than reset value.
      5-2   GPIOx Mode                                                 (R/W)
              0 = GPIOx disabled (input and output buffers powered down)
              1 = GPIOx input mode (as secondary BCLK/WCLK/SDIN input, or
                       as ADC_WCLK input, Dig_Mic_In or in ClockGen block)
              2 = GPIOx input mode (as GPI general-purpose input)
              3 = GPIOx output = general-purpose output
              4 = GPIOx output = CLKOUT output
              5 = GPIOx output = INT1 output
              6 = GPIOx output = INT2 output
              7 = GPIOx output = ADC_WCLK output for codec interface
              8 = GPIOx output = secondary BCLK output for codec interface
              9 = GPIOx output = secondary WCLK output for codec interface
              10 = GPIOx output = ADC_MOD_CLK output for the digital microphone
              11 = GPIOx output = secondary SDOUT for codec interface
              12 = GPIOx output = TouchScreen/SAR ADC interrupt (active-low),
              13-15 = Reserved                              as PINTDAV signal
      1     GPIOx input buffer value (0 or 1)                         (R)
      0     GPIOx general-purpose output value (0 or 1)               (R/W)

TSC[0:35h] - SDOUT (OUT Pin) Control (12h)

      7-5   Reserved
      4     SDOUT bus keeper (0=Enabled, 1=Disabled)
      3-1   SDOUT Mode
              0 = SDOUT disabled (output buffer powered down)
              1 = SDOUT = primary SDOUT output for codec interface
              2 = SDOUT = general-purpose output
              3 = SDOUT = CLKOUT output
              4 = SDOUT = INT1 output
              5 = SDOUT = INT2 output
              6 = SDOUT = secondary BCLK output for codec interface
              7 = SDOUT = secondary WCLK output for codec interface
      0     SDOUT general-purpose output value (0 or 1)

TSC[0:36h] - SDIN (IN Pin) Control (02h or 03h)

      7-3   Reserved
      2-1   SDIN Mode
              0 = SDIN disabled (input buffer powered down)
              1 = SDIN enabled (as codec SDIN, Dig_Mic_In, or in ClockGen block)
              2 = SDIN enabled (as GPI general-purpose input)
              3 = Reserved
      0     SDIN input-buffer value (0 or 1)                          (R)

TSC[0:37h] - MISO (OUT Pin) Control (02h)

      7-5   Reserved
      4-1   MISO Mode
              0 = MISO disabled (output buffer powered down)
              1 = MISO = MISO output for SPI interface (or disabled for I2C)
              2 = General-purpose output
              3 = MISO = CLKOUT output
              4 = MISO = INT1 output
              5 = MISO = INT2 output
              6 = MISO = ADC_WCLK output for codec interface
              7 = MISO = ADC_MOD_CLK output for the digital microphone
              8 = MISO = secondary SDOUT for codec interface
              9 = MISO = secondary BCLK output for codec interface
              10 = MISO = secondary WCLK output for codec interface
              11-15 = Reserved
      0     MISO general-purpose output value (0 or 1)

TSC[0:38h] - SCLK (IN Pin) Control (02h..03h)

      7-3   Reserved
      2-1   SCLK Mode
              0 = SCLK disabled (input buffer powered down)
              1 = SCLK enabled (for the SPI interface)
              2 = SCLK enabled (as a GPI general-purpose input)
              3 = SCLK enabled (as secondary SDIN/BCLK/WCLK input,
                                or as ADC_WCLK input, or Dig_Mic_In)
      0     SCLK input buffer value (0 or 1)                         (R)

TSC[0:39h] - GPI1 and GPI2 Pin Control (00h..11h)

      7     Reserved. Write only zero to this bit.
      6-5   GPI1 Mode
              0 = GPI1 disabled (input buffer powered down)
              1 = GPI1 enabled (as secondary SDIN/BCLK/WCLK input, or ADC_WCLK inp)
              2 = GPI1 enabled (as a GPI general-purpose input)
              3 = Reserved (unlike below GPI2)
      4     GPI1 pin value (0 or 1)         (R)
      3     Reserved. Write only zero to this bit.
      2-1   GPI2 Mode
              0 = GPI2 disabled (input buffer powered down)
              1 = GPI2 enabled (as secondary BCLK/WCLK input, or ADC_WCLK input)
              2 = GPI2 enabled (as a GPI general-purpose input)
              3 = GPI2 enabled (as an HP_SP input)
      0     GPI2 pin value (0 or 1)         (R)

TSC[0:3Ah] - GPI3 Pin Control (00h..10h)

      7     Reserved. Write only zero to this bit.
      6-5   GPI3 Mode
              0 = GPI3 disabled (input buffer powered down)
              1 = GPI3 enabled (as secondary BCLK/WCLK input, or ADC_WCLK input)
              2 = GPI3 enabled (as a GPI general purpose input)
              3 = Reserved (Undocumented - used by DSi?)
      4     GPI3 pin value (0 or 1)         (R)
      3-0   Reserved. Write only zeros to these bits.

TSC[0:3Bh] - Reserved (xxh)

      7-0   Reserved. Write only zeros to these bits.

DSi TSC[0:3Ch..55h], DAC/ADC and Beep

TSC[0:3Ch] - DAC Instruction Set (01h)

      7-5   Reserved. Write only default value.
      4-0   DAC Signal Processing Block
              0      = DAC miniDSP is used for signal processing
              1..25  = DAC Signal Processing Block PRB_P1 .. PRB_P25
              26..31 = Reserved. Do not use.

TSC[0:3Dh] - ADC Instruction Set (04h)

      7-5   Reserved. Write only default values.
      4-0   ADC Signal Processing Block
              0      = ADC miniDSP is used for signal processing
              1..3   = Reserved
              4..6   = ADC Signal Processing Block PRB_R4 .. PRB_R6
              7..9   = Reserved
              10..12 = ADC Signal Processing Block PRB_R10 .. PRB_R12
              13..15 = Reserved
              16..18 = ADC Signal Processing Block PRB_R16 .. PRB_R18
              19..31 = Reserved. Do not write these sequences to these bits.

TSC[0:3Eh] - Programmable Instruction Mode-Control Bits (00h)

      7     Reserved
      6     ADC miniDSP Engine Auxiliary Control bit A (0 or 1)
      5     ADC miniDSP Engine Auxiliary Control bit B (0 or 1)
      4     Reset ADC miniDSP instruction counter at start of new frame (0=Yes)
      3     Reserved
      2     DAC miniDSP Engine Auxiliary Control bit A (0 or 1)
      1     DAC miniDSP Engine Auxiliary Control bit B (0 or 1)
      0     Reset DAC miniDSP instruction counter at start of new frame (0=Yes)

Above DAC/ADC bit A and B can be used for conditional instructions like JMP.
TSC[0:3Fh] - DAC Data-Path Setup (14h)

      7     Left-channel DAC            (0=Powered down, 1=Powered up)
      6     Right-channel DAC           (0=Powered down, 1=Powered up)
      5-4   Left-channel DAC data path  (0=Off, 1=Left Data, 2=Right Data, 3=Both)
      3-2   Right-channel DAC data path (0=Off, 1=Right Data, 2=Left Data, 3=Both)
      1-0   DAC channel volume control soft-stepping (0=One step per sample,
             1=One step per 2 samples, 2=Disabled, 3=Reserved)

Wheras, Both=((L+R)/2).
TSC[0:40h] - DAC Volume Control (0Ch)

      7-4   Reserved. Write only zeros to these bits.
      3     Left-channel DAC  (0=Not muted, 1=Muted)
      2     Right-channel DAC (0=Not muted, 1=Muted)
      1-0   DAC Mono/Stereo Volume
              0: Use Left/Right volume control for Left/Right channels ("stereo")
              1: Use Right volume control for Both channels            ("mono")
              2: Use Left volume control for Both channels             ("mono")
              3: Same as 0                                             ("stereo")

TSC[0:41h] - DAC Left Volume Control (00h)
TSC[0:42h] - DAC Right Volume Control (00h)

      7-0  Digital gain in 0.5dB units (-127..+48 = -63.5dB..+24dB, Other=Reserved)

TSC[0:43h] - Headset Detection (00h..60h)

      7     Headset detection Enable (0=Disabled, 1=Enabled)
      6-5   Headset detection (0=None, 1=Headset, 2=Reserved, 3=Headset+Mic) (R)
      4-2   Debounce for Glitch Rejection During Headset Detection
              (0..5 = 16ms, 32ms, 64ms, 128ms, 256ms, 512ms, 6..7=Reserved)
              (when TSC[3:10h] set to 1MHz)
      1-0   Debounce for Glitch Rejection During Headset Button-Press Detection
              (0..3 = 0ms, 8ms, 16ms, 32ms) (when TSC[3:10h] set to 1MHz)

Sampling is 8x faster than above timings (eg. time=32ms uses 4ms sampling).
TSC[0:44h] - DRC Control 1 (0Fh)

      7     Reserved. Write only the reset value to these bits.
      6     DRC for left channel  (0=Disabled, 1=Enabled)
      5     DRC for right channel (0=Disabled, 1=Enabled)
      4-2   DRC threshold  (0..7 = -3dB,-6dB,-9dB,-12dB,-15dB,-18dB,-21dB,-24dB)
      1-0   DRC hysteresis (0..3 = +0dB,+1dB,+2dB,+3dB)

TSC[0:45h] - DRC Control 2 (38h)

      7     Reserved. Write only the reset value to these bits.
      6-3   DRC Hold Time
              0  = DRC Hold Disabled        ;-disable
              1  = 32 DAC Word Clocks       ;\
              2  = 64 DAC Word Clocks       ;
              3  = 128 DAC Word Clocks      ;
              4  = 256 DAC Word Clocks      ; powers of 2
              5  = 512 DAC Word Clocks      ;
              6  = 1024 DAC Word Clocks     ;
              7  = 2048 DAC Word Clocks     ;
              8  = 4096 DAC Word Clocks     ;
              9  = 8192 DAC Word Clocks     ;
              10 = 16384 DAC Word Clocks    ;/
              11 = 1*32768 DAC Word Clocks  ;\
              12 = 2*32768 DAC Word Clocks  ;
              13 = 3*32768 DAC Word Clocks  ; multiples of 32768
              14 = 4*32768 DAC Word Clocks  ;
              15 = 5*32768 DAC Word Clocks  ;/
      2-0   Reserved. Write only the reset value to these bits.

TSC[0:46h] - DRC Control 3 (00h)

      7-4   DRC attack rate, "(4 SHR N) dB per DAC Word Clock"
            (0=4dB, 1=2dB, 2=1dB, ..., 15=0.000122dB per DAC Word Clock)
      3-0   DRC decay rate, "(1 SHR (N+6)) dB per DAC Word Clock"
            (0=0.0156dB, 1=0.00781dB, ..., 15=0.000000476dB per DAC Word Clock)

TSC[0:47h] - Beep Generator and Left Beep Volume (00h)

      7     Beep Generator Enable (0=Disabled/Duration ended, 1=Enabled/Busy)
              (self-clearing based on beep duration)
      6     Auto beep generator on pen touch (0=Disabled, 1=Enabled)
              (CODEC_CLKIN should be available for this and is
              used whenever touch is detected).
      5-0   Left-channel beep volume control "(2-N)dB" (0..63 = +2dB .. -61dB)

The beep generator is only available in PRB_P25 DAC processing mode.
TSC[0:48h] - Beep Generator and Right Beep Volume (00h)

      7-6   Beep Mono/Stereo Volume
              0: Use Left/Right volume control for Left/Right channels ("stereo")
              1: Use Right volume control for Both channels            ("mono")
              2: Use Left volume control for Both channels             ("mono")
              3: Same as 0                                             ("stereo")
      5-0   Right-channel beep volume control "(2-N)dB" (0..63 = +2dB .. -61dB)

The beep generator is only available in PRB_P25 DAC processing mode.
TSC[0:49h,4Ah,4Bh] - Beep Length MSB,MID,LSB (0000EEh)

      23-0  Number of samples for which beep need to be generated (24bit)

TSC[0:4Ch,4Dh] - Beep Frequency Sin(x) MSB,LSB (10D8h)
TSC[0:4Eh,4Fh] - Beep Frequency Cos(x) MSB,LSB (7EE3h)

      15-0  Beep Frequency sin/cos values (16bit, each)

These registers should be set to sin(2pi*fin/fS) and cos(2pi*fin/fS) accordingly; where fin is the beep frequency and fS is the DAC sample rate.
TSC[0:50h] - Reserved (xxh)

      7-0   Reserved. Write only the reset value to these bits.

TSC[0:51h] - ADC Digital Mic (00h)

      7     ADC channel   (0=Powered Down, 1=Powered Up)
      6     Reserved
      5-4   Digital microphone input  (0=GPIO1, 1=SCLK, 2=SDIN, 3=GPIO2)
      3     Digital microphone for delta-sigma mono ADC channel (0=Off, 1=On)
      2     Reserved
      1-0   ADC channel volume control soft-stepping (0=One step per sample,
             1=One step per 2 samples, 2=Disabled, 3=Reserved)

TSC[0:52h] - ADC Digital Volume Control Fine Adjust (80h)

      7     ADC channel   (0=Not muted, 1=Muted)
      6-4   Delta-Sigma Mono ADC Channel Volume Control Fine Gain
            (0=0dB, 1=-0.1dB, 2=-0.2dB, 3=-0.3dB, 4=-0.4dB, 5..7=Reserved)
      3-0   Reserved. Write only zeros to these bits.

TSC[0:53h] - ADC Digital Volume Control Coarse Adjust (00h)

      7     Reserved
      6-0   Delta-Sigma Mono ADC Channel Volume Control Coarse Gain
              0..39    = Reserved
              40       = -12 dB
              39       = -11.5 dB
              ...
              103      = +19.5 dB
              104      = +20 dB
              105..127 = Reserved

TSC[0:54h,55h] - Reserved (xxh)

      7-0   Reserved. Write only the reset value to these bits.

DSi TSC[0:56h..7Fh], AGC and ADC

Auto-Gain-Control & Analog-to-Digital Converter
TSC[0:56h] - AGC Control 1 (00h)

      7     AGC (0=Disabled, 1=Enabled)
      6-4   AGC target level     (0=-5.5dB, 1=-8dB, 2=-10dB, 3=-12dB,
                                  4=-14dB, 5=-17dB, 6=-20dB, 7=-24dB)
      3-0   Reserved. Write only zeros to these bits.

TSC[0:57h] - AGC Control 2 (00h)

      7-6   AGC hysterysis setting (0=1dB, 1=2dB, 2=4dB, 3=Disable AGC hysterysis)
      5-1   AGC noise threshold (and silence detection)
              0   = AGC noise/silence detection is disabled.
              1   = AGC noise threshold = -30dB
              2   = AGC noise threshold = -32dB
              3   = AGC noise threshold = -34dB
              ...
              29  = AGC noise threshold = -86dB
              30  = AGC noise threshold = -88dB
              31  = AGC noise threshold = -90dB
      0     Reserved. Write only zero to this bit.

TSC[0:58h] - AGC Maximum Gain (7Fh, uh that's 7Fh=Reserved?)

      7     Reserved. Write only zero to this bit.
      6-0   AGC maximum gain in 0.5dB units (0..119=0..+59.5dB, 120..127=Reserved)

TSC[0:59h] - AGC Attack Time (00h)
TSC[0:5Ah] - AGC Decay Time (00h)

      7-3   AGC attack/decay time, (N*2+1)*32/fS (0..31 = 1*32/fS .. 63*32/fS)
      2-0   AGC attack/decay time Multiply factor, 1 SHL N (0..7 = 1..128)

Whereas, fS is the ADC sample rate.
TSC[0:5Bh] - AGC Noise Debounce (00h)

      7-5   Reserved. Write only zeros to these bits.
      4-0   AGC noise debounce
              0..5   = 0/fS, 4/fS, 8/fS, 16/fS, 32/fS, 64/fS     ;\powers of 2
              6..10  = 128/fS, 256/fS, 512/fS, 1024/fS, 2048/fS  ;/
              11..14 = 1*4096/fS, 2*4096/fS, 3*4096/fS           ;\multiples
              14..31 = 4*4096/fS, .., 20*4096/fS, 21*4096/fS     ;/of 4096

TSC[0:5Ch] - AGC Signal Debounce (00h)

      7-4   Reserved. Write only zeros to these bits.
      3-0   AGC signal debounce
              0..5   = 0/fS, 4/fS, 8/fS, 16/fS, 32/fS, 64/fS     ;\powers of 2
              6..9   = 128/fS, 256/fS, 512/fS, 1024/fS           ;/
              10..13 = 1*2048/fS, 2*2048/fS, 3*2048/fS           ;\multiples
              13..15 = 4*2048/fS, 5*2048/fS, 6*2048/fS           ;/of 2048

TSC[0:5Dh] - AGC Gain-Applied Reading (xxh) (R)

      7-0   Gain applied by AGC in 0.5dB units (-24..+119 = -12dB..+59.5dB)   (R)

TSC[0:5Eh...65h] - Reserved (xxh)

      7-0   Reserved. Do not write to these registers.

TSC[0:66h] - ADC DC Measurement 1 (00h)

      7     DC measurement for mono ADC channel (0=Disabled, 1=Enabled)
      6     Reserved. Write only reset value.
      5     DC measurement is done based on
              0: 1st order sinc filter with averaging of 2^D.
              1: 1st order low-pass IIR filter whose coefficients
                  are calculated based on D value.
      4-0   DC Meaurement D setting (1..20 = D=1 .. D=20) (0 or 21..31=Reserved)

TSC[0:67h] - ADC DC Measurement 2 (00h)

      7     Reserved. Write only reset value.
      6     DC measurement data update (0=Enabled, 1=Disabled/allow stable reading)
            (Disabled: user can read the last updated data without corruption)
      5     For IIR based DC measurement, the measurment value is
              0: the instantaneous output of the IIR filter
              1: update before periodic clearing of the IIR filter
      4-0   IIR based DC measurment, average time setting:
              0       Infinite average is used
              1       Averaging time is 2^1 ADC modulator clock periods
              2       Averaging time is 2^2 ADC modulator clock periods
              ...
              19      Averaging time is 2^19 ADC modulator clock periods
              20      Averaging time is 2^20 ADC modulator clock periods
              21..31  Reserved. Don't use.

TSC[0:68h,69h,6Ah] - ADC DC Measurement Output MSB,MID,LSB (R) (000000h)

      23-0  ADC DC Measurement Output (24bit)

TSC[0:6Bh...73h] - Reserved (xxh)

      7-0   Reserved. Do not write to these registers.

TSC[0:74h] - VOL/MICDET-Pin SAR ADC - Volume Control (00h)

      7     DAC volume control is controlled by,
              0: controlled by control register (7-bit Vol ADC is powered down)
              1: controlled by pin (analog volume input)
      6     Clock for the 7-bit Vol ADC for pin volume control,
              0: Internal on-chip RC oscillator
              1: External MCLK
      5-4   Hysteresis
              0: No hysteresis for volume control ADC output
              1: Hysteresis of +/-1 bit
              2: Hysteresis of +/-2 bits
              3: Reserved. Do not write this sequence to these bits.
      3     Reserved. Write only reset value.
      2-0   Throughput of the 7-bit Vol ADC for pin volume control,
            When Bit6=1 and external MCLK is 12MHz:
              (0..7=15.625Hz, 31.25Hz, 62.5Hz, 125Hz, 250Hz, 500Hz, 1000Hz, 2000Hz)
            When Bit6=0 (use Internal oscillator):
              (0..7=10.68Hz, 21.35Hz, 42.71Hz, 85Hz?, 170Hz, 340Hz, 680Hz, 1370Hz)

TSC[0:75h] - VOL/MICDET-Pin Gain (xxh) (R)

      7     Reserved. Write only zero to this bit.
      6-0   Gain applied by pin volume control
              0   = +18 dB
              1   = +17.5 dB
              2   = +17 dB
              ...
              35  = +0.5 dB
              36  = 0 dB
              37  = -0.5 dB
              ...
              89  = -26.5 dB
              90  = -27 dB    ;below in 1dB steps instead of 0.5dB steps !
              91  = -28 dB
              ...
              125 = -62 dB
              126 = -63 dB
              127 = Reserved

TSC[0:76h...7Fh] - Reserved (xxh)

      7-0   Reserved. Do not write to these registers.

DSi TSC[1:xxh], DAC and ADC Routing, PGA, Power-Controls and MISC Logic

TSC[1:01h..1Dh] - Reserved (xxh)

      7-0  Reserved. Do not write to these registers.

TSC[1:1Eh] - Headphone and Speaker Amplifier Error Control (00h)

      7-2  Reserved
      1    Reset HPL/HPR power-up bits upon short-circuit detect (0=Yes, 1=No)
      0    Reset SPL/SPR power-up bits upon short-circuit detect (0=Yes, 1=No)

The HPL/HPR auto-reset occurs only if TSC[1:1Fh].Bit1=1 (action=power down).
TSC[1:1Fh] - Headphone Drivers (04h)

      7    HPL output driver (0=Powered down, 1=Powered up)
      6    HPR output driver (0=Powered down, 1=Powered up)
      5    Reserved. Write only zero to this bit.
      4-3  Output common-mode voltage (0=1.35V, 1=1.5V, 2=1.65V, 3=1.8V)
      2    Reserved. Write only 1 to this bit. (!!!)
      1    Action when short-circuit protection is enabled/detected,
               0=Limit the maximum current to the load.
               1=Power down the output driver.
      0    Short-circuit detected on the headphone driver (0=No, 1=Yes) (R)

TSC[1:20h] - Class-D Speaker Amplifier (06h)

      7    Left-channel class-D output driver  (0=Powered down, 1=Powered up)
      6    Right-channel class-D output driver (0=Powered down, 1=Powered up)
      5-1  Reserved. Write only the reset value (00011b) to these bits (!!!)
      0    Short-circuit is detected on the class-D driver (0=No, 1=Yes) (R)

Bit0 is Valid only if class-D amplifier is powered up. For short-circuit flag sticky bit, see TSC[0:2Ch].
TSC[1:21h] - HP Output Drivers POP Removal Settings (3Eh)

      7    If power down sequence is activated by device software power down
           using TSC[1:2Eh].Bit7 then power down DAC,
             0: simultaneously with the HP and SP amplifiers.
             1: after HP and SP amplifiers are completely powered down.
             (the latter setting is to optimize power-down POP).
      6-3  Driver power-on time (at 8.2MHz) (1=15.3us, 2=153us, 3=1.53ms,
             4=15.3ms,5=76.2ms, 6=153ms, 7=304ms, 8=610ms, 9=1.22s, 10=3.04s,
             11=6.1s, 12..15=Reserved)
      2-1  Driver ramp-up step time (8.2MHz) (0=0ms, 1=0.98ms, 2=1.95ms, 3=3.9ms)
      0    Weakly driven output common-mode voltage is generated from,
             0=resistor divider of the AVDD supply.
             1=band-gap reference.

TSC[1:22h] - Output Driver PGA Ramp-Down Period Control (00h)

      7    Reserved. Write only the reset value to this bit.    (USED on DSi!)
      6-4  Speaker Power-Up Wait Time (at 8.2MHz) (0=0 ms, 1=3.04 ms, 2=7.62 ms,
             3=12.2 ms, 4=15.3 ms, 5=19.8 ms, 6=24.4 ms, 7=30.5 ms)
      3-0  Reserved. Write only the reset value to these bits.

TSC[1:23h] - DAC_L and DAC_R Output Mixer Routing (00h)

      7-6  DAC_L route      (0=Nowhere, 1=To L-Mixer, 2=Direct to HPL, 3=Reserved)
      5    MIC input routed to the left-channel mixer amplifier      (0=No, 1=Yes)
      4    AUX1 input routed to the left-channel mixer amplifier     (0=No, 1=Yes)
      3-2  DAC_R route      (0=Nowhere, 1=To R-Mixer, 2=Direct to HPR, 3=Reserved)
      1    AUX1 input routed to the right-channel mixer amplifier    (0=No, 1=Yes)
      0    HPL driver output routed to HPR driver (for differential) (0=No, 1=Yes)

TSC[1:24h] - Analog Volume to HPL (Left Headphone) (7Fh)
TSC[1:25h] - Analog Volume to HPR (Right Headphone) (7Fh)
TSC[1:26h] - Analog Volume to SPL (Left Speaker) (7Fh)
TSC[1:27h] - Analog Volume to SPR (Right Speaker) (7Fh)

      7    Analog volume control routed to HPx/SPx output driver (0=No, 1=Yes)
      6-0  Analog volume control gain (non-linear) (0 dB to -78 dB)

See Table 5-37 and Table 5-38, uh?
TSC[1:28h] - HPL Driver (Left Headphone) (02h)
TSC[1:29h] - HPR Driver (Right Headphone) (02h)

      7    Reserved. Write only zero to this bit.
      6-3  HPx driver PGA  (0..9 = 0dB..9dB, 10..15=Reserved)
      2    HPx driver      (0=Muted, 1=Not muted)
      1    HPx driver during power down (0=Weakly driven to a common mode,
            1=High-impedance)
      0    All programmed gains to HPx have been applied (0=Not yet, 1=Yes/all) (R)

TSC[1:2Ah] - SPL Driver (Left Speaker) (00h)
TSC[1:2Bh] - SPR Driver (Right Speaker) (00h)

      7-5  Reserved. Write only zeros to these bits.
      4-3  SPx class-D driver output stage gain (0=6dB, 1=12dB, 2=18dB, 3=24dB)
      2    SPx class-D driver (0=Muted, 1=Not muted)
      1    Reserved. Write only zero to this bit.
      0    All programmed gains to SPx have been applied (0=Not yet, 1=Yes/all) (R)

TSC[1:2Ch] - HP Driver Control (00h)

      7-5  Debounce time for the headset short-circuit detection
             (0..7 = 0us, 8us, 16us, 32us, 64us, 128us, 256us)
             (when TSC[3:10h] set to 1MHz)
      4-3  DAC Performance (0=Normal, 1=Increased, 2=Reserved, 3=Further Increased)
           (increased: by increased current, further: by increased current gain)
      2    HPL output driver type (0=Headphone, 1=Lineout)
      1    HPR output driver type (0=Headphone, 1=Lineout)
      0    Reserved. Write only zero to this bit.

The clock used for the debounce has a clock period = debounce duration/8.
TSC[1:2Dh] - Reserved (xxh)

      7-0  Reserved. Do not write to these registers.

TSC[1:2Eh] - MICBIAS (00h)

      7    Device software power-down (0=Disabled, 1=PowerDown?-Enabled)
      6-4  Reserved. Write only zeros to these bits.
      3    Power up programmed MICBIAS  (0=Only if Headset inserted, 1=Always)
      2    Reserved. Write only zero to this bit.
      1-0  MICBIAS output (0=Off, 1=2V, 2=2.5V, 3=AVDD)

TSC[1:2Fh] - MIC PGA (80h)

      7    MIC PGA            (0=Controlled by bits6-0, 1=Force 0dB)
      6-0  PGA in 0.5dB units (0..119 = 0..59.5dB, 120..127=Reserved)

TSC[1:30h] - P-Terminal Delta-Sigma Mono ADC Channel Fine-Gain Input (00h)

      7-6  MIC to MIC PGA feed-forward    (0=Off, 1=10kOhm, 2=20kOhm, 3=40kOhm)
      5-4  AUX1 to MIC PGA feed-forward   (0=Off, 1=10kOhm, 2=20kOhm, 3=40kOhm)
      3-2  AUX2 to MIC PGA feed-forward   (0=Off, 1=10kOhm, 2=20kOhm, 3=40kOhm)
      1-0  Reserved. Write only zeros to these bits.

Program Bit7-6 of registers TSC[1:30h] and TSC[1:31h] with same value. Input impedance selection affects the microphone PGA gain. See the Analog Front End section for details.
TSC[1:31h] - M-Terminal ADC Input Selection (00h)

      7-6  CM to MIC PGA feed-forward     (0=Off, 1=10kOhm, 2=20kOhm, 3=40kOhm)
      5-4  AUX2 to MIC PGA feed-forward   (0=Off, 1=10kOhm, 2=20kOhm, 3=40kOhm)
      3-0  Reserved. Write only zeros to these bits.

Program Bit7-6 of registers TSC[1:30h] and TSC[1:31h] with same value. Input impedance selection affects the microphone PGA gain. See the Analog Front End section for details.
TSC[1:32h] - Input CM Settings (00h)

      7    MIC input  (0=Floating, 1=Connected to CM internally)
            (when not used for MIC PGA and analog bypass)
      6    AUX1 input (0=Floating, 1=Connected to CM internally)
            (when not used for MIC PGA and analog bypass)
      5    AUX2 input (0=Floating, 1=Connected to CM internally)
            (when not used for MIC PGA)
      4-1  Reserved. Write only zeros to these bits.
      0    All programmed gains to ADC have been applied (0=Not yet, 1=Yes/all) (R)

TSC[1:33h..FFh] - Reserved (xxh)

      7-0  Reserved. Write only the reset value to these bits.

DSi TSC[3:xxh], Touchscreen/SAR Control and TSC[FCh:xxh], Buffer

TSC[3:01h] - Reserved (xxh)

      7-0   Reserved. Write only the reset value to these bits.

TSC[3:02h] - SAR ADC Control 1 (00h)

      7     Stop  (0=Normal mode, 1=Stop conversion and power down SAR ADC)
      6-5   SAR ADC resolution   (0=12bit, 1=8bit, 2=10bit, 3=12bit)
      4-3   SAR ADC clock divider
              0 = Div1 (use for 8bit resolution mode only) (This divider is only
                        for the conversion clock generation, not for other logic)
              1 = Div2 (use for 8bit/10bit resolution mode only)
              2 = Div4 (recommended for better performance in 8bit/10bit mode)
              3 = Div8 (recommended for better performance in 12bit mode)
              (See Figure 5-40, uh?)
      2     Filter used for on-chip data averaging (0=Mean, 1=Median) (if enabled)
      1-0   On-chip data averaging for mean/median filter
              0 = On-chip data averaging disabled
              1 = 4-data averaging (mean),  or 5-data averaging (median)
              2 = 8-data averaging (mean),  or 9-data averaging (median)
              3 = 16-data averaging (mean), or 15-data averaging (median)

TSC[3:03h] - SAR ADC Control 2 (00h)

      7     Conversions controlled,
              0 = Host-controlled conversions
              1 = Self-controlled conversions for touch screen based on pen touch
      6     Reserved. Write only zero to this bit.
      5-2   Conversion Mode
              0 = No scan
              1 = Scan X/Y         ;\Even in host-controlled mode ;\until either
              2 = Scan X/Y/Z1/Z2   ;/                             ; pen is lifted,
              3 = Scan X           ;\                             ; or a stop bit
              4 = Scan Y           ; Only in self-controlled mode ; TSC[3:02h].Bit7
              5 = Scan Z1/Z2       ;/                             ;/is sent
              6 = VBAT measurement
              7 = AUX2 measurement
              8 = AUX1 measurement
              9 = Auto scan. Sequence used is AUX1, AUX2, VBAT.
                  Each of these inputs can be enabled or disabled independently
                  using TSC[3:13h], and with that sequence is modified accordingly.
                  Scan continues until stop bit TSC[3:02h].Bit7 is sent,
                  or Bit5-2 of this register are changed.
             10 = TEMP1 measurement
             11 = Port scan: AUX1, AUX2, VBAT
             12 = TEMP2 measurement
             13-15 = Reserved. Do not write these sequences to these bits.
      1-0   Interrupt pin (GPIO1 or GPIO2 pin)
              0 = PEN-interrupt    /PENIRQ (active low)
              1 = Data-available   /DATA_AVA (active low)
              2 = PEN-interrupt    PENIRQ and Data-available DATA_AVA (active high)
              3 = Reserved

TSC[3:04h] - Precharge and Sense (00h)

      7     Pen touch detection (0=Enabled, 1=Disabled)
      6-4   Precharge time before touch detection
            (0..7 = 0.25us, 1us, 3us, 10us, 30us, 100us, 300us, 1000us)
            (when TSC[3:11h] set to 8MHz)
      3     Reserved. Write only zero to this bit.
      2-0   Sense time during touch detection
            (0..7 = 1us, 2us, 3us, 10us, 30us, 100us, 300us, 1000us)
            (when TSC[3:11h] set to 8MHz)

TSC[3:05h] - Panel Voltage Stabilization (00h)

      7-6   SAR comparator bias current (0=Normal, 1..3=Increase by 25%, 50%, 100%)
            (use Increase to support higher conversion clock)
      5     Sample duration (0=Default, 1=Doubled; for higher impedance)
      4-3   Reserved. Write only zeroes to these bits.
      2-0   Panel voltage stabilization time before conversion
            (0..7 = 0.25us, 1us, 3us, 10us, 30us, 100us, 300us, 1000us)
            (when TSC[3:11h] set to 8MHz)

TSC[3:06h] - Voltage Reference (20h)

      7     Reference for Non-touch-screen Measurement  (0=External, 1=Internal)
      6     Internal reference voltage   (0=1.25V, 1=2.5V)
      5     Internal reference powered   (0=Always, 1=Only during conversion)
      4     Reserved
      3-2   Reference Stabilization Time before Conversion
            (0=0us, 1=100us, 2=500us, 3=1ms) (when TSC[3:11h] set to 8MHz)
      1     Reserved
      0     Battery measurement input (0=VBAT<=VREF, 1=VBAT=BAT)

TSC[3:07h,08h] - Reserved (xxh)

      7-0   Reserved. Write only the reset value to these bits.

TSC[3:09h] - Status Bits 1 (40h) (R)

      7     Pen Touch detected          (0=Not detected, 1=Detected) (R)
      6     ADC Ready                   (0=Busy, 1=Ready)            (R)
      5     New data is available       (0=None, 1=Yes)              (R)
      4     Reserved. Write only the reset value to this bit.
      3     New X data is available     (0=None, 1=Yes)              (R)
      2     New Y data is available     (0=None, 1=Yes)              (R)
      1     New Z1 data is available    (0=None, 1=Yes)              (R)
      0     New Z2 data is available    (0=None, 1=Yes)              (R)

Bit0-3 and Bit5 are not valid for the buffer mode.
Bit0-3 are cleared after reading the corresponding data.
Bit5 is cleared after completely reading ALL data.
TSC[3:0Ah] - Status Bits 2 (00h) (R)

      7     New AUX1 data is available  (0=None, 1=Yes)              (R)
      6     New AUX2 data is available  (0=None, 1=Yes)              (R)
      5     New VBAT data is available  (0=None, 1=Yes)              (R)
      4-2   Reserved. Write only zeros to these bits.
      1     New TEMP1 data is available (0=None, 1=Yes)              (R)
      0     New TEMP2 data is available (0=None, 1=Yes)              (R)

Bit0-1 and Bit5-7 are not valid for the buffer mode.
Bit0-1 and Bit5-7 are cleared after reading the corresponding data.
TSC[3:0Bh,0Ch] - Reserved (xxh)

      7-0   Reserved. Write only the reset value to these bits.

TSC[3:0Dh] - Buffer Mode (03h)

      7     Buffer Mode Enable (0=Disabled, 1=Enabled)
              (when disabled: RDPTR/WRPTR/TGPTR are set to their default values)
      6     Buffer Mode Type   (0=Countinuos-conversion, 1=Single-shot)
      5-3   Trigger level for conversion "(N+1)*8*number of converted data"
              0..7 = (8..64)*number of converted data
              uh, does "X*number of converted data" mean "after X conversions"?
      2     Reserved
      1     Buffer Full  (0=No, 1=Full; contains 64 unread converted data)   (R)
      0     Buffer Empty (0=No, 1=Empty; contains 0 unread converted data)   (R)

However, in DSi this register is unused, and DSi does instead use TSC[3:0Eh].
TSC[3:0Eh] - Reserved / Undocumented (read by DSi for Pen Down Test) (0Fh)

      7-0   Reserved. Write only the reset value to these bits.

However, in DSi this is used as so... (seems to resemble TSC[3:0Dh])...

      7     Undoc Enable   (0=Disabled, 1=Enabled)  (R/W)
      6     Undoc Whatever (0=Normal)               (R/W)
      5-3   Undoc Whatever (5=Normal)               (R/W)
      2     Undoc Unused                            (?)
      1     Undoc Pendown/DataAvailable?            (R?)
      0     Undoc Unused                            (R?)

TSC[3:0Fh] - Scan Mode Timer (40h)

      7     Programmable delay for Touch-screen measurement (0=Disable, 1=Enable)
      6-4   Programmable interval timer delay
              (0..7 = 8ms, 1ms, 2ms, 3ms, 4ms, 5ms, 6ms, 7ms)
              (when TSC[3:10h] set to 1MHz)
      3     Programmable delay for Non-touch-screen auto measurement   (1=Enable)
      2-0   Programmable interval timer delay (0..7 = 1.12min, 3.36min,
              5.59min, 7.83min, 10.01min, 12.30min, 14.54min, 16.78min)
              (uh, what is that? minutes? minimum? or what?)
              (when TSC[3:10h] set to 1MHz)

These delays are from the end of one data set of conversion to the start of another new data set of conversion.
Bit7: This interval timer mode is for all self-controlled modes. For host-controlled mode, it is valid only for (X/Y) or (X/Y/Z1/Z2) conversions.
TSC[3:10h] - Scan Mode Timer Clock (81h)

      7     Clock used for Programmable Delay Timer (0=Internal Osc/8, 1=Ext. MCLK)
      6-0   MCLK Divider to Generate 1-MHz Clock for the Programmable Delay Timer
            (1..127=Div1..127, or 0=Div128)

The timings marked "(when TSC[3:10h] set to 1MHz)" are assuming the MCLK division result to be 1MHz (1us). Other divider settings will cause those timings to change. Using Internal Osc/8 (Bit7=0) results in 1.025MHz (0.97us), which is almost same as the "1MHz" timings (internal osc isn't too accurate though).
Bit7: External clock is used only to control the delay programmed between the conversions and not used for doing the actual conversion. This is supported to get an accurate delay, because the internal oscillator frequency varies from device to device.
TSC[3:11h] - SAR ADC Clock (81h)

      7     Clock used for SAR ADC and TSC FSM (0=Internal Osc/1, 1=External MCLK)
      6-0   MCLK Divider for the SAR (min 40ns)  (1..127=Div1..127, or 0=Div128)

The timings marked "(when TSC[3:11h] set to 8MHz)" are assuming the MCLK division result to be 8MHz (125ns). Other divider settings will cause those timings to change. For the SAR unit, the division result should be max 25MHz (min 40ns). Using Internal Osc/1 (Bit7=0) results in 8.2MHz (122ns), which is almost same as the "8MHz" timings (internal osc isn't too accurate though).
TSC[3:12h] - Debounce Time for Pen-Up Detection (00h)

      7     Interface used for the buffer data reading   (0=SPI, 1=I2C)
      6     SAR/buffer data update is,
              0: held automatically (to avoid simultaneous buffer read and write
                   operations) based on internal detection logic.
              1: held using software control and TSC[3:12h].Bit5.
      5     SAR/buffer data update is (only if above Bit6=1),
               0: enabled all the time
               1: stopped so that user can read the last updated data
                     without any data corruption.
      4-3   Reserved. Write only zeros to these bits.
      2-0   Pen-touch removal detection with debounce
              (0..7 = 0us, 8us, 16us, 32us, 64us, 128us, 256us, 512us)
              (when TSC[3:10h] set to 1MHz)

The clock used for the debounce has a clock period = debounce duration/8.
TSC[3:13h] - Auto AUX Measurement Selection (00h)

      7     Auto AUX1 measurement during auto non-touch screen scan (0=Off, 1=On)
      6     Auto AUX2 measurement during auto non-touch screen scan (0=Off, 1=On)
      5     Auto VBAT measurement during auto non-touch screen scan (0=Off, 1=On)
      4     Auto TEMP measurement during auto non-touch screen scan (0=Off, 1=On)
      3     TEMP Measurement (0=Use TEMP1, 1=Use TEMP2)
      2     AUX1 Usage (0=Voltage measurement, 1=Resistance measurement)
      1     AUX2 Usage (0=Voltage measurement, 1=Resistance measurement)
      0     Resistance measurement bias (0=Internal bias, 1=External bias)

TSC[3:14h] - Touch-Screen Pen Down (00h)

      7-3   Reserved
      2-0   Debounce Time for Pen-Down Detection
              (0..7 = 0us, 64us, 128us, 256us, 512us, 1024us, 2048us, 4096us)
              (when TSC[3:10h] set to 1MHz)

The clock used for the debounce has a clock period = debounce duration/8.
TSC[3:15h] - Threshold Check Flags Register (00h) (R)

      7-6   Reserved. Write only zeros to these bits.
      5     AUX1 Maximum (0=Inrange, 1=Exceeds Limit; Equal/Above MAX)
      4     AUX1 Minimum (0=Inrange, 1=Exceeds Limit; Equal/Below MIN)
      3     AUX2 Maximum (0=Inrange, 1=Exceeds Limit; Equal/Above MAX)
      2     AUX2 Minimum (0=Inrange, 1=Exceeds Limit; Equal/Below MIN)
      1     TEMP Maximum (0=Inrange, 1=Exceeds Limit; Equal/Above MAX)
      0     TEMP Minimum (0=Inrange, 1=Exceeds Limit; Equal/Below MIN)

Sticky flag bIts. These are read-only bits. They are automatically cleared once they are read and are set only if the source trigger occurs again.
TSC[3:16h,17h] - AUX1 Maximum Value Check MSB,LSB (0000h)
TSC[3:18h,19h] - AUX1 Minimum Value Check MSB,LSB (0000h)
TSC[3:1Ah,1Bh] - AUX2 Maximum Value Check MSB,LSB (0000h)
TSC[3:1Ch,1Dh] - AUX2 Minimum Value Check MSB,LSB (0000h)
TSC[3:1Eh,1Fh] - Temperature(TEMP1/TEMP2) Maximum Value Check MSB,LSB (0000h)
TSC[3:20h,21h] - Temperature(TEMP1/TEMP2) Minimum Value Check MSB,LSB (0000h)

      15-13  Reserved
      12     Threshold check (0=Disabled, 1=Enabled)
             (valid for auto/non-auto scan measurement).
      11-0   Threshold code (12bit)

TSC[3:2Ah,2Bh] - Touchscreen X-Coordinate Data MSB,LSB (0000h) (R)
TSC[3:2Ch,2Dh] - Touchscreen Y-Coordinate Data MSB,LSB (0000h) (R)
TSC[3:2Eh,2Fh] - Touchscreen Z1-Pressure Register MSB,LSB (0000h) (R)
TSC[3:30h,31h] - Touchscreen Z2-Pressure Register MSB,LSB (0000h) (R)
TSC[3:36h,37h] - AUX1 Data MSB,LSB (0000h) (R)
TSC[3:38h,39h] - AUX2 Data MSB,LSB (0000h) (R)
TSC[3:3Ah,3Bh] - VBAT Data MSB,LSB (0000h) (R)
TSC[3:42h,43h] - Temperature TEMP1 Data Register MSB,LSB (0000h) (R)
TSC[3:44h,45h] - Temperature TEMP2 Data Register MSB,LSB (0000h) (R)

      15-0   Data... but, seems to be always zero on DSi?

Going by the datasheet, these registers should contain current sample values, but they seem to be always zero on DSi.
Instead, the samples for the currently selected Conversion Mode can be read from the buffer at TSC[FCh:01h,02h], using the buffer should also ensure that MSB/LSB-pairs won't change within 16bit reads.
TSC[3:22h...29h] - Reserved (xxh)
TSC[3:32h...35h] - Reserved (xxh)
TSC[3:3Ch...41h] - Reserved (xxh)
TSC[3:46h...7Fh] - Reserved (xxh)

      7-0    Reserved. Write only the reset value to these bits.

TSC[FCh:01h,02h] - Buffer Mode Data MSB,LSB (xxxxh) (R)

      15    Ring-buffer Full  (1=All 64 entries are unread)
      14    Ring-buffer Empty (1=All 64 entries are read)
      13    Reserved          (uh?)
      12    Data ID           (0=X/Z1/BAT/AUX2, 1=Y/Z2/AUX1/TEMP)
      11-0  Converted data (12bit), read from "RDPTR" ring-buffer location

Note: One can/must read multiple words from index 01h (the index will somewhat automatically toggle between 01h and 02h in that case (or perhaps it does increment to 03h and up, but those indices mirror to 01h and 02h)).
TSC[FCh:03h..7Fh] - Reserved (xxh) (actually mirrors of TSC[FCh:01h,02h])

      7-0   Reserved. Write only the reset value to these bits.

These are somewhat mirrors of the buffer at TSC[FCh:01h,02h]. Trying to select index=03h starts reading with the 1st buffer byte (ie. it won't start at the 3rd byte).

DSi TSC[04h..05h:xxh], ADC Digital Filter Coefficient RAM

Default values shown for this page only become valid 100us following a hardware or software reset.
TSC[04h-05h:xxh] - ADC Coefficient RAM (126 x 16bit)
Coefficients are signed 16bit (-32,768..+32,767), each occupying 2 bytes (MSB,LSB).
The MSB should always be written first, immediately followed by the LSB (even if only the MSB or LSB portion of the coefficient changes, both registers should be written in this sequence).

                       ADC miniDSP   ADC FIR Filter Special
                       Coefficients  Coefficients   Coefficients
      TSC[4:00h]       Page Select   -              -
      TSC[4:01h]       Reserved      -              -
      TSC[4:02h..07h]  C1..C3        -              N0,N1,D1 for AGC LPF
                                                      (first-order IIR, used
                                                      as averager to detect level)
      TSC[4:08h..0Dh]  C4..C6        -              N0,N1,D1 for ADC-programmable
                                                      first-order IIR
      TSC[4:0Eh..17h]  C7..C11       FIR0..FIR4     N0,N1,N2,D1,D2 for ADC Biquad A
      TSC[4:18h..21h]  C12..C16      FIR5..FIR9     N0,N1,N2,D1,D2 for ADC Biquad B
      TSC[4:22h..2Bh]  C17..C21      FIR10..FIR14   N0,N1,N2,D1,D2 for ADC Biquad C
      TSC[4:2Ch..35h]  C22..C26      FIR15..FIR19   N0,N1,N2,D1,D2 for ADC Biquad D
      TSC[4:36h..3Fh]  C27..C31      FIR20..FIR24   N0,N1,N2,D1,D2 for ADC Biquad E
      TSC[4:40h..7Fh]  C32..C63      -              -
      TSC[5:00h]       Page Select   -              -
      TSC[5:01h]       Reserved      -              -
      TSC[5:02h..7Fh]  C65..C127     -              -

Multi-order FIR Filter (Finite Impulse Response)

      input[n] ---o--MUL(F0)-->ADD-----------------> output[n]
                  |             ^
              input[n-1]        |                          ;\
                  |             |                          ; first order FIR
                  o--MUL(F1)-->ADD                         ;/
                  |             ^
              input[n-2]        |                          ;\
                  |             |                          ; second order FIR
                  o--MUL(F2)-->ADD                         ;/
                  :             ^
                  :             :                          ;-further order's

First-order IIR Filter (Infinite Impulse Response)

      input[n] ---o--MUL(N0)-->ADD-------------o---> output[n]
                  |             ^              |
              input[n-1]        |          output[n-1]     ;\
                  |             |              |           ; first order IIR
                  o--MUL(N1)-->ADD<--MUL(-D1)--o           ;/

Biquad Filter (IIR with 1st and 2nd order)

      input[n] ---o--MUL(N0)-->ADD-------------o---> output[n]
                  |             ^              |
              input[n-1]        |          output[n-1]     ;\
                  |             |              |           ; first order IIR
                  o--MUL(N1)-->ADD<--MUL(-D1)--o           ;/
                  |             ^              |
              input[n-2]        |          output[n-2]     ;\
                  |             |              |           ; second order IIR
                  o--MUL(N2)-->ADD<--MUL(-D2)--o           ;/

DSi TSC[08h..0Fh:xxh], DAC Digital Filter Coefficient RAM

Default values shown for this page only become valid 100us following a hardware or software reset.
TSC[08h:01h] - DAC Coefficient RAM Control (00h)

      7-4   Reserved. Write only the reset value.
      3     DAC miniDSP generated flag for toggling MSB of coefficient RAM address
            (only used in non-adaptive mode)                                (R)
      2     DAC Adaptive Filtering in DAC miniDSP (0=Disabled, 1=Enabled)   (R/W)
      1     DAC Adaptive Filter Buffer Control Flag                         (R)
              aka DAC Coefficient Buffers in adaptive filter mode
                 0: miniDSP accesses Buffer A,
                      external control interface (=the user?) accesses Buffer B
                 1: miniDSP accesses Buffer B,
                      external control interface (=the user?) accesses Buffer A
      0     DAC Adaptive Filter Buffer Switch Control                       (R/W)
             0: DAC coefficient buffers will not be switched at next frame boundary
             1: DAC coefficient buffers will     be switched at next frame boundary
                (only if adaptive filtering mode is enabled)
                This bit will self-clear on switching.

TSC[08h..0Bh:xxh] - DAC Coefficient RAM, DAC Buffer A (252 x 16bit)
Coefficients are signed 16bit (-32,768..+32,767), each occupying 2 bytes (MSB,LSB).
The MSB should always be written first, immediately followed by the LSB (even if only the MSB or LSB portion of the coefficient changes, both registers should be written in this sequence).

                       DAC miniDSP    Special
                      (DAC Buffer A)  DAC-programmable
                       Coefficient    Coefficient
      TSC[8:00h]       Page Select    -
      TSC[8:01h]       Control        - (see above)
      TSC[8:02h..0Bh]  C1..C5         N0,N1,N2,D1,D2 for Left Biquad A  ;N0=7FFFh
      TSC[8:0Ch..15h]  C6..C10        N0,N1,N2,D1,D2 for Left Biquad B  ;N1,N2,D1,
      TSC[8:16h..1Fh]  C11..C15       N0,N1,N2,D1,D2 for Left Biquad C  ;     D2=0
      TSC[8:20h..29h]  C16..C20       N0,N1,N2,D1,D2 for Left Biquad D
      TSC[8:2Ah..33h]  C21..C25       N0,N1,N2,D1,D2 for Left Biquad E
      TSC[8:34h..3Dh]  C26..C30       N0,N1,N2,D1,D2 for Left Biquad F
      TSC[8:3Eh..3Fh]  C31            -
      TSC[8:40h..41h]  C32            for 3D PGA for PRB_P23, PRB_P24 and PRB_P25
      TSC[8:42h..4Bh]  C33..C37       N0,N1,N2,D1,D2 for Right Biquad A
      TSC[8:4Ch..55h]  C38..C42       N0,N1,N2,D1,D2 for Right Biquad B
      TSC[8:56h..5Fh]  C43..C47       N0,N1,N2,D1,D2 for Right Biquad C
      TSC[8:60h..69h]  C48..C52       N0,N1,N2,D1,D2 for Right Biquad D
      TSC[8:6Ah..73h]  C53..C57       N0,N1,N2,D1,D2 for Right Biquad E
      TSC[8:74h..7Dh]  C58..C62       N0,N1,N2,D1,D2 for Right Biquad F
      TSC[8:7Eh..7Fh]  C63            -
      TSC[9:00h]       Page Select    -
      TSC[9:01h]       Reserved       - (do not write to this register)
      TSC[9:02h..07h]  C65..C67       N0,N1,D1 for Left first-order IIR
      TSC[9:08h..0Dh]  C68..C70       N0,N1,D1 for Right first-order IIR
      TSC[9:0Eh..13h]  C71..C73       N0,N1,D1 for DRC first-order high-pass filter
      TSC[9:14h..19h]  C74..C76       N0,N1,D1 for DRC first-order low-pass filter
      TSC[9:1Ah..7Fh]  C77..C127      -
      TSC[A:00h]       Page Select    -
      TSC[A:01h]       Reserved       - (do not write to this register)
      TSC[A:02h..7Fh]  C129..C191     -
      TSC[B:00h]       Page Select    -
      TSC[B:01h]       Reserved       - (do not write to this register)
      TSC[B:02h..7Fh]  C193..C255     -

TSC[0Ch..0Fh:xxh] - DAC Coefficient RAM, DAC Buffer B (252 x 16bit)
This is essentially same as above Buffer A. But it's unclear if Buffer B is having the same special Biquad/3DPGA/IIR/DRC functions (the official datasheet doesn't mention them, but it does specify the initial reset values same as for Buffer A, ie. with value 7FFFh for the locations that correspond to "N0" coefficients, which is suggesting that those special functions are present in Buffer B, too).

                       DAC miniDSP    Special
                      (DAC Buffer A)  DAC-programmable
                       Coefficient    Coefficient
      TSC[C:02h..0Bh]  C1..C5         Unknown  ;\
      TSC[C:0Ch..15h]  C6..C10        Unknown  ;
      TSC[C:16h..1Fh]  C11..C15       Unknown  ; maybe Left Biquad A..F
      TSC[C:20h..29h]  C16..C20       Unknown  ; as for Buffer A
      TSC[C:2Ah..33h]  C21..C25       Unknown  ;
      TSC[C:34h..3Dh]  C26..C30       Unknown  ;/
      TSC[C:3Eh..3Fh]  C31            -
      TSC[C:40h..41h]  C32            Unknown maybe 3D PGA as for Buffer A
      TSC[C:42h..4Bh]  C33..C37       Unknown  ;\
      TSC[C:4Ch..55h]  C38..C42       Unknown  ;
      TSC[C:56h..5Fh]  C43..C47       Unknown  ; maybe Right Biquad A..F
      TSC[C:60h..69h]  C48..C52       Unknown  ; as for Buffer A
      TSC[C:6Ah..73h]  C53..C57       Unknown  ;
      TSC[C:74h..7Dh]  C58..C62       Unknown  ;/
      TSC[C:7Eh..7Fh]  C63            -
      TSC[D:00h]       Page Select    -
      TSC[D:01h]       Reserved       - (do not write to this register)
      TSC[D:02h..07h]  C65..C67       Unknown  ;\
      TSC[D:08h..0Dh]  C68..C70       Unknown  ; maybe IIR and DRC
      TSC[D:0Eh..13h]  C71..C73       Unknown  ; as for Buffer A
      TSC[D:14h..19h]  C74..C76       Unknown  ;/
      TSC[D:1Ah..7Fh]  C77..C127      -
      TSC[E:00h]       Page Select    -
      TSC[E:01h]       Reserved       - (do not write to this register)
      TSC[E:02h..7Fh]  C129..C191     -
      TSC[F:00h]       Page Select    -
      TSC[F:01h]       Reserved       - (do not write to this register)
      TSC[F:02h..7Fh]  C193..C255     -

DSi TSC[20h..2Bh:xxh], TSC[40h..5Fh:xxh] ADC/DAC Instruction RAM

TSC[20h..2Bh:xxh] - ADC DSP Engine Instruction RAM (384 x 24bit)
ADC miniDSP Instructions are 20bit, each occupying 3 bytes (MSB,MID,LSB) (with dummy padding in upper 4bit of MSB).

      TSC[20h..2Bh:00h]       Page Select
      TSC[20h..2Bh:01h]       Reserved
      TSC[20h:02h...61h]      ADC Instructions 0...31
      TSC[21h:02h...61h]      ADC Instructions 32...63
      TSC[22h:02h...61h]      ADC Instructions 64...95
      TSC[23h:02h...61h]      ADC Instructions 96...127
      TSC[24h:02h...61h]      ADC Instructions 128...159
      TSC[25h:02h...61h]      ADC Instructions 160...191
      TSC[26h:02h...61h]      ADC Instructions 192...223
      TSC[27h:02h...61h]      ADC Instructions 224...255
      TSC[28h:02h...61h]      ADC Instructions 256...287
      TSC[29h:02h...61h]      ADC Instructions 288...319
      TSC[2Ah:02h...61h]      ADC Instructions 320...351
      TSC[2Bh:02h...61h]      ADC Instructions 352...383
      TSC[20h..2Bh:62h..7Fh]  Reserved

TSC[40h..5Fh:xxh] - DAC DSP Engine Instruction RAM (1024 x 24bit)
DAC miniDSP Instructions are 24bit (uh, unlike 20bit ADC ones?), each occupying 3 bytes (MSB,MID,LSB).

      TSC[40h..5Fh:00h]       Page Select
      TSC[40h..5Fh:01h]       Reserved
      TSC[40h:02h...61h]      DAC Instructions 0...31
      TSC[41h:02h...61h]      DAC Instructions 32...63
      TSC[42h:02h...61h]      DAC Instructions 64...95
      TSC[43h:02h...61h]      DAC Instructions 96...127
      TSC[44h:02h...61h]      DAC Instructions 128...159
      TSC[45h:02h...61h]      DAC Instructions 160...191
      TSC[46h:02h...61h]      DAC Instructions 192...223
      TSC[47h:02h...61h]      DAC Instructions 224...255
      TSC[48h:02h...61h]      DAC Instructions 256...287
      TSC[49h:02h...61h]      DAC Instructions 288...319
      TSC[4Ah:02h...61h]      DAC Instructions 320...351
      TSC[4Bh:02h...61h]      DAC Instructions 352...383
      TSC[4Ch:02h...61h]      DAC Instructions 384...415
      TSC[4Dh:02h...61h]      DAC Instructions 416...447
      TSC[4Eh:02h...61h]      DAC Instructions 448...479
      TSC[4Fh:02h...61h]      DAC Instructions 480...511
      TSC[50h:02h...61h]      DAC Instructions 512...543
      TSC[51h:02h...61h]      DAC Instructions 544...575
      TSC[52h:02h...61h]      DAC Instructions 576...607
      TSC[53h:02h...61h]      DAC Instructions 608...639
      TSC[54h:02h...61h]      DAC Instructions 640...671
      TSC[55h:02h...61h]      DAC Instructions 672...703
      TSC[56h:02h...61h]      DAC Instructions 704...735
      TSC[57h:02h...61h]      DAC Instructions 736...767
      TSC[58h:02h...61h]      DAC Instructions 768...799
      TSC[59h:02h...61h]      DAC Instructions 800...831
      TSC[5Ah:02h...61h]      DAC Instructions 832...863
      TSC[5Bh:02h...61h]      DAC Instructions 864...895
      TSC[5Ch:02h...61h]      DAC Instructions 896...927
      TSC[5Dh:02h...61h]      DAC Instructions 928...959
      TSC[5Eh:02h...61h]      DAC Instructions 960...991
      TSC[5Fh:02h...61h]      DAC Instructions 992...1023
      TSC[40h..5Fh:62h..7Fh]  Reserved

The miniDSP instruction set isn't officially documented anywhere. Texas Instruments has merely released an "assembler" for the miniDSP (that is, a graphical drag-and-drop utility referred to as PurePath Studio).

DSi I2C Bus

I2C Bus
DSi I2C I/O Ports
DSi I2C Signals
Device 4Ah (BPTWL chip) (LED/Volume/Powerbutton/Reset)
DSi I2C Device 4Ah (BPTWL chip)
Device 78h/7Ah (Aptina MT9V113 Cameras)
DSi Aptina Camera Initialization
Directly addressed I2C Registers (16bit index, 16bit data):
DSi Aptina Camera Registers: SYSCTL (0000h-0051h)
DSi Aptina Camera Registers: RX_SS, FUSE, XDMA (0100h-099Fh)
DSi Aptina Camera Registers: CORE (3000h-31FFh, 38xxh)
DSi Aptina Camera Registers: SOC1 (3210h-33FDh)
DSi Aptina Camera Registers: SOC2 (3400h-3729h)
Indirectly addressed MCU Variables (via above "XDMA" commands):
DSi Aptina Camera Variables: RAM/SFR/MON (GPIO/Monitor) (MCU:0000h-20xxh)
DSi Aptina Camera Variables: SEQ (Sequencer) (MCU:21xxh)
DSi Aptina Camera Variables: AE (Auto Exposure) (MCU:22xxh)
DSi Aptina Camera Variables: AWB (Auto White Balance) (MCU:23xxh)
DSi Aptina Camera Variables: FD (Anti-Flicker) (MCU:24xxh)
DSi Aptina Camera Variables: MODE (Mode/Context) (MCU:27xxh)
DSi Aptina Camera Variables: HG (Histogram) (MCU:2Bxxh)
I2C Bus Caution: The Camera I2C access requires the "16.76MHz Camera External Clock" enabled in Port 4004004h.Bit8 on ARM9 Side. For accessing registers other than SYSCTL/CORE, one must also clear the Standby flag in SYSCTL[0018h].
Device A0h/E0h (Unknown, maybe cameras from other manufacturer)
DSi Alternate Cameras from Unknown Manufacturer
Camera Data Transfers
Camera configuration is done on ARM7 side via serial I2C bus. However, the actual Camera Data transfers are done on ARM9 side through 8bit parallel bus:
DSi Cameras
Broken Cameras (defunct device 78h/7Ah/A0h/E0h)
Consoles should contain two Aptina cameras, or two Unknown cameras. The Unlaunch installer is throwing a warning when detecting Unknown cameras, so far nobody has reported that case, so Unknown cameras seem to be very rare (if they were ever used at all). However, two people reported that warning showing FFh's in the ID bytes for most or all cameras (caused by a broken camera with only one working camera, or broken camera connector with no working cameras at all).
Bottom line is that broken cameras are more common than unknown cameras, and games with optional/extra camera features should support that situation: ie. disable the feature in case of broken camera(s) instead of becoming unplayable.
Device 90h (Whatever)
Trying to read IC2 for this device just returns FFh? Maybe exists in debug version only. The firmware contains a few functions for accessing this register.

      Register  Width   Description
      02h       1       Used for DSi IRQ6 IF flags
                          uh, IF.Bit6 would be Timer3overflow ?
                          or, IF2.Bit6 would be PowerButton ?
      04h       1       Unknown (bit0 toggled)

Unknown purpose.
Device 40h (Whatever) (and New3DS QTM)
Trying to read IC2 for this device just returns FFh? Maybe exists in debug version only. The firmware doesn't use this register (it does only contain the device number in the device table).
Caution: New3DS does use device number 40h for the QTM IO Expander, this device will be visible in DSi mode (and shouldn't be mistaken for whatever DSi device 40h was originally used for).
DSi I2C Devices

      Device  Delay      Description
      7Ah     0       0  Camera0(internal)  ;Aptina MT9V113 (SelfPortrait)
      78h     0       1  Camera1(external)  ;Aptina MT9V113 (External)
      A0h     0       2  Camera0 config (Ext) ;\maybe for other manufacturer?
      E0h     0       3  Camera1 config (Self);/
      4Ah     180h    4  BPTWL Chip (LED/Volume/Powerbutton/Reset)
      40h     0       5  Debug?
      90h     0       6  Debug?

Delay: required swiWaitByLoop delay
DSi Secondary I2C Devices
There are also some internal/secondary I2C busses (not connected to the ARM CPUs).

      xxh   Power Managment Device                       (connected to BPTWL chip)
      50h   I2C bus potentiometer (volume D/A converter) (connected to BPTWL chip)
      A0h   I2C bus EEPROM                        (connected to Atheros wifi chip)
      -     I2C voltage translator                (between ARM CPU and BPTWL chip)

DSi I2C I/O Ports

4004500h - DSi7 - I2C_DATA (R/W)

      0-7  Data (or Device, or Register)

When sending data, I2C_DATA should be written <before> setting I2C_CNT.bit7.
When reading data, I2C_DATA should be read <after> I2C_CNT.bit7 goes off.
Alongsides with the 8bit data, an additional 1bit "Ack" flag is transferred as response to the data (ie. in opposite direction of data direction), the Ack is located in I2C_CNT.Bit4, and it's usually indicating errors (or in some cases it appears to be also used to indicate that no further data is to be transferred).
4004501h - DSi7 - I2C_CNT (R/W)

      0    Stop  (0=No, 1=Stop/last byte)
      1    Start (0=No, 1=Start/first byte)
      2    Error (0=No, 1=Pause/Flush? after Error, used with/after Stop)
      3    Unknown/unused (0)
      4    Ack Flag         (0=Error, 1=Okay)  (For DataRead: W, for DataWrite: R)
      5    Data Direction   (0=Write, 1=Read)
      6    Interrupt Enable (0=Disable, 1=Enable)
      7    Start/busy       (0=Ready, 1=Start/busy)

I2C Transfer Flowchart
The first byte (with the "Start" condition) contains the device number, which consists of a 7bit chip ID and a direction flag in bit0 (0=Write or 1=Read). The direction flag applies to all following bytes (until last byte with "Stop" condition), that rule means that "Write Index & Write Data" can be done in a single step, whilst "Write Index & Read Data" must be split into two separate steps (each with own "Start/Stop" conditions):

     For Writing:
      Write Device+0 (with Start condition)                 ;\
      Write Index byte(s)                                   ; write index + data
      Write Data byte(s) (last byte with Stop condition)    ;/
     For Reading:
      Write Device+0 (with Start condition)                 ;\1st step: write index
      Write Index byte(s) (last byte with Stop condition)   ;/
      Write Device+1 (with Start condition)                 ;\2nd step: read data
      Read Data byte(s) (last byte with Stop condition)     ;/

The index is usually a single byte (except for Aptina cameras, which do use 16bit indices transferred in two bytes; ordered MSB, LSB).
Per-byte transfer completion is indicated by the Start/busy flag, which should also indicate if the I2C chip is ready for next byte (I2C devices can hold the clock line low if they aren't ready), however, the BPTWL chip somehow doesn't support that, and it should be accessed with an extra delay:

      Invoke byte-transfer
      Do WaitByLoop (needed for the BPTWL device only)
      Wait for start/busy flag to get zero

Note: The DSi firmware is doing eight retries per I2C command (in case of receiving wrong ACK bytes), unknown if that's really required, a stable system should never need to do retries.

DSi I2C Signals

Below is some pseudo code for the I2C signal transmission. The DSi hardware is doing most of that stuff automatically. The pseudo code may be useful for understanding the purpose of the start/stop/ack flags in the control register.

           START D7  D6  D5  D4  D3  D2  D1  D0 ACK  D7  D6/ .. /D1  D0 ACK STOP
          __    ___ ___ ___ ___ ___ ___ ___ ___     ___ __/    /___ ___        ___
      SDA   |__|___|___|___|___|___|___|___|___|___|___|_/ .. /|___|___|______|
          ____   _   _   _   _   _   _   _   _   _   _  /    /   _   _   _   _____
      SCL     |_| |_| |_| |_| |_| |_| |_| |_| |_| |_| |/ .. / |_| |_| |_| |_|
                                                     /    /
           <--><------------------------------><--><--------------------><--><-->
           Start    Device/Direction Byte      Ack   Index/Data Byte(s)  Ack Stop

SDA should be changed at/after falling SCL edge (except for Start/Stop conditions, which are output during SCL=High).
The Device/Direction Byte is sent by master (the byte contains a 7bit device address in bit7-1, and a direction flag in bit0). The direction of the follwing index/data byte(s) depends on that direction flag (0=Write, 1=Read). The ACK bit responses are sent in opposite direction as the preceeding byte.
The SCL line is driven by master, however, when the master changes SCL from Low to HighZ, then the slave may keep SCL held Low to signalize that it isn't yet ready for the next bit.
i2c_write_byte(send_start,send_stop,databyte):

      if (send_start) then i2c_start_cond()                     ;-start (if so)
      for i=7 downto 0, i2c_write_bit(databyte.bit(i)), next i  ;-write 8bit
      nack = i2c_read_bit()                                     ;-read nack
      if (send_stop) then i2c_stop_cond()                       ;-stop (if so)
      return nack        ;return 0 if ack by the slave.         ;-return nack

i2c_read_byte(nack,send_stop):

      for i=7 downto 0, databyte.bit(i)=i2c_read_bit(), next i  ;-read 8bit
      i2c_write_bit(nack)                                       ;-write nack
      if (send_stop) then i2c_stop_cond()                       ;-stop (if so)
      return databyte                                           ;-return databyte

i2c_write_bit(bit):

      if (bit) then SDA=HighZ else SDA=Low          ;-
      I2C_delay()                                   ;-
      SCL=HighZ
      wait until SCL=High (or timeout)              ;-wait (for clock stretching)
      if (bit=1 and SDA=Low) then arbitration_lost();-errif other HW pulls SDA=low
      I2C_delay()                                   ;-
      SCL=Low                                       ;-

i2c_read_bit():

      SDA=HighZ                                     ;-let the slave drive data
      I2C_delay()                                   ;-delay (one half clk)
      SCL=HighZ
      wait until SCL=High (or timeout)              ;-wait (for clock stretching)
      bit = SDA                     ;-
      I2C_delay()                   ;-delay (one half clk)
      SCL=Low                       ;-
      return bit                    ;-

i2c_start_cond():

      if (started) then            ;if started, do a restart cond
        SDA=HighZ                   ;-set SDA to 1
        I2C_delay()
        SCL=HighZ
        wait until SCL=High (or timeout)         ;-wait (for clock stretching)
        I2C_delay()         ;Repeated start setup time, minimum 4.7us
      if (SDA=Low) then arbitration_lost()
      SDA=Low                       ;-
      I2C_delay()
      SCL=Low
      started = true

i2c_stop_cond():

      SDA=Low                               ;-
      I2C_delay()                           ;-
      SCL=HighZ                             ;-
      wait until SCL=High (or timeout)      ;-wait (for clock stretching)
      I2C_delay()   ;Stop bit setup time, minimum 4us
      if (SDA=Low) then arbitration_lost()
      I2C_delay()
      started = false

DSi I2C Device 4Ah (BPTWL chip)

I2C Bus Caution: The BPTWL chip requires swiWaitByLoop(180h) after each I2C byte transfer (if the Version/Speed byte at BPTWL[00h] indicates "Fast", then the delay can be reduced to 90h instead of 180h).
And, SPI bus Powerman chip does somehow interact with I2C BPTWL chip; there must be a similar delay between Powerman writes and BPTWL writes.
BPTWL Chip (LED/Volume/Powerbutton/Reset) (Device 4Ah)

      00h     R   Version/Speed (usually 33h) (00h..20h=Slow, 21h..FFh=Fast)
      01h     R   Unknown (00h)
      02h     R   Unknown (50h)
      03h-0Fh -   Reserved (5Ah-filled)
      10h     R   Power Button Status (bit0=WasWhat?, bit1=IsDown, bit3=WasDown?)
                    (bit0/3 are cleared after reading)
      11h     R/W Reset (00h=No, 01h=Force Reset, 02h=???)
      12h     R/W Power Button Tapping (00h=Auto-Reset, 01h=IRQ)
      13h-1Fh -   Reserved (5Ah-filled)
      20h     R   Battery State (bit0..3=Battery Level, bit7=Charge)
              W   On 3DS in DSi mode: Write 8=Shutdown, 4=Return to 3DS mode ?
      21h     R/W Unknown (07h)
      22h-2Fh -   Reserved (5Ah-filled)
      30h     R/W Wifi LED (0/2=Off, 1=On, 3=BlinkOnTraffic) and bit4=SDIO enable
      31h     R/W Camera LED (00h=Off, 01h=On, 02h=Blink)
      32h-3Fh -   Reserved (5Ah-filled)
      40h     R/W Volume Level (00h..1Fh)             ;\nonvolatile!
      41h     R/W Backlight Level (00h..04h)          ;/
      42h-5Fh -   Reserved (5Ah-filled)
      60h     ??  Unknown (00h) FFh: Disable I2C reading, and Purple Power LED?
      61h     R   Unknown (01h)
      62h     R   Unknown (50h)
      63h     R/W Unknown (00h) FFh: Purple Power LED (red+blue on)
      64h-6Fh -   Reserved (5Ah-filled)
      70h     R/W Bootflag (00h=Coldboot, 01h=Warmboot/SkipHealthSafety)
      71h     R/W Unknown (00h)
      72h-77h R/W Unknown (00h-filled)
      78h-7Fh -   Reserved (5Ah-filled)
      80h     R/W Unknown (10h)     ;\can affect/disable Power Button Tapping
      81h     R/W Unknown (64h)     ;/
      82h-FFh -   Reserved (5Ah-filled)

The R/W values can be set to 00h..FFh (except Index 40h/41h are quickly cropped to max 1Fh/04h, and Index 70h/71h are (after some time) cropped to 01h/02h).
Above should probably also include:

      Forced volume (for alerts) (ie. alternately to current "user volume")

BPTWL Emulation on 3DS
The 3DS MCU emulates the BPTWL chip for DSi mode (and the emulated registers can be also accessed in 3DS mode). The emulation supports only a few of the original BPTWL registers & bits though:

      00h     R   Version/Speed (35h on New3DS)
      10h     R   Power Button Status (only 2 bits?: bit3=WasDown?, bit6=?)
      11h     R/W Reset (01h=Reset, other=ignored) (read: always 00h)
      12h     R/W Power Button Tapping (bit0,1,7=?)
      20h     R   Battery State
      31h     R/W Camera LED (bit0,1)
      40h     R/W Volume Level
      70h     R/W Bootflag
      Other   -   Unused (FFh)

DSi Power Button
Logically, the Power Button has two functions:

      Short tap --> reset (warmboot, go to DSi menu, without health and safety)
      Hold 1 second --> power-off

Technically, the button can have three functions:

      Auto-Reset (used for NDS games)
      IRQ (supposed to be used with Manual-Reset) (used for DSi games)
      Forced Power-off (for games which fail to handle the IRQ within 5 seconds)

DSi games should handle the IRQ as follows: First, do some clean up (like finishing writes to SD/MMC storage; to avoid FAT corruption). Then, issue a Reset manually (via I2C/BPTWL registers [70h]=01h/Warmboot, [11h]=01h/Reset).
Power-Off can be implemented via SPI/Power Managment Device, however, games only need to implement Manual-Reset or Auto-Reset, but don't need to implement Power-Off (the firmware will do that automatically if the button is held down for 1 second after issuing the Reset).
Ideally, emulators should also reproduce the power button (when resetting or closing the emulator): Signalize power-button and keep the emulation running until the game responds by Reset (or until five second timeout). That will allow the game to finish writes to emulated SD/MMC storage.
DSi Autostart on Warmboot (20h-byte area) (also requires BPTWL[70h]=01h)
The DSi can be commanded to load a different title (eg. System Settings), instead of showing the Boot Menu after warmboot.
DSi Autoload on Warmboot
Older blurb...

      0x10    1       Power flags. When bit0 is set, arm7 does a system reset.
                        When bit1 or bit3 are set, arm7 does a shutdown. Bits 0-2
                        are used for DSi IRQ6 IF flags (uh, rather IF2 maybe?).
      0x20    1       Battery flags. When zero the battery is at critical level,
                        arm7 does a shutdown. Bit7 is set when the battery is
                        charging. Battery levels in the low 4-bits: battery icon
                        bars full 0xF, 3 bars 0xB, 2 bars 0x7, one solid red bar
                        0x3, and one blinking red bar 0x1. When plugging in or
                        removing recharge cord, this value increases/decreases
                        between the real battery level and 0xF, thus the battery
                        level while bit7 is set is useless.

BPTWL/BPUTL Chip Names

      DSi:      Renesas Electronics "BPTWL, KG07K"           ;reg[00h]=33h
      DSiXL:    Renesas Electronics "BP UTL-1, KG08"         ;reg[00h]=BBh or B7h
      3DS:      Renesas Electronics "UC CTR, 041KM73, KG10"  ;reg[00h]=?
      New3DSXL: Renesas Electronics "UC KTR, 423KM01, 'TK14" ;reg[00h]=35h

DSi Autoload on Warmboot

Overview
Launcher (and unlaunch) can be commanded to autoload a different title.

      2000000h  Autoload Parameters for newly loaded title  ;<-- optional extra
      2000300h  Autoload via numeric Title ID               ;<-- official method
      2000800h  Autoload via string "device:\path\filename" ;<-- alternate method
      2FFD800h  Title List (jump-able titles for use at 2000300h)
      BPTWL[70h].bit0  Warmboot flag                        ;<-- required flag
      BPTWL[11h].bit0  Trigger reset                        ;<-- trigger reset

Moreover, autoload can occur on warmboot & coldboot: Launcher autoloads any ROM cartridge with carthdr[01Fh].Bit2. Unlaunch defaults to autoload any file named "sdmc:\bootcode.dsi".
Examples
DSi Browser settings screen allows to autoload System Settings (via 2000300h), and automatically enter the Internet options page (via 2000000h).
Nintendo Zone, if started with Wireless Communications disabled, allows to reboot itself (via specifying it's own Title ID in 2000300h).
Homebrew frontends for unlaunch could start themselves (via bootcode.dsi) and then command unlaunch to load another title (via 2000800h or 2000300h).
2000000h - Optional Auto-load parameters (passed on to new title)

      2000000h 8    AutoParam Old Title ID (former title)    ;carthdr[230h]
      2000008h 1    AutoParam Unknown/Unused
      2000009h 1    AutoParam Flags (03h=Stuff is used?)
      200000Ah 2    AutoParam Old Maker code                 ;carthdr[010h]
      200000Ch 2    AutoParam Unknown (02ECh) ;\counter/length/indices/whatever?
      200000Eh 2    AutoParam Unknown (0000h) ;/
      2000010h 2    AutoParam CRC16 on [000h..2FFh], initial=FFFFh, [010h]=0000h
      2000012h 2    AutoParam Unknown/Unused (000Fh = want Internet Settings?)
      2000014h 2ECh AutoParam Unknown... some buffer... string maybe?

Above is the overall skeleton as intended by Nintendo, the purpose/format of the 2ECh bytes is unknown (there seems to be some relation to entries [0Ch] and [0Eh], but theoretically, each title could use that bytes as pleased).
2000300h - Nintendo Auto-load feature (via numeric Title ID)

      2000300h 4    AutoLoad ID ("TLNC")
      2000304h 1    AutoLoad Unknown/unused (usually 01h)
      2000305h 1    AutoLoad Length of data at 2000308h (01h..18h,for CRC,18h=norm)
      2000306h 2    AutoLoad CRC16 of data at 2000308h (with initial value FFFFh)
      2000308h 8    AutoLoad Old Title ID (former title) (can be 0=anonymous)
      2000310h 8    AutoLoad New Title ID (new title to be started,0=none/launcher)
      2000318h 4    AutoLoad Flags (bit0, 1-3, 4, 5,6,7) ;usually 16bit, once 32bit
      200031Ch 4    AutoLoad Unused (but part of checksummed area when CRC len=18h)
      2000320h E0h  AutoLoad Unused (but zerofilled upon erasing autoload area)

Flags (usually 13h or 17h):

      0     IsValid (somehow enables/disables HealthSafety when TitleID is wrong?)
      1-3   Boottype (01h=Cartridge, 02h=Landing, 03h=DSiware) (see below)
      4     Unknown
      5     Unknown
      6     LoadCompl (causes some error when set) (loading completed flag?)
      7     Unknown
      8-15  Unused
      16-31 Unused (usually not accessed at all, with normal 16bit reads)

Boottypes (in Flags.bit1-3):

      01h = Cartridge (with NewTitleID)    (with RSA signed header, or Whitelisted)
      02h = Landing ("nand:/tmp/jump.app") (with RSA signed DownloadPlay footer)
      03h = DSiware (with NewTitleID)      (with RSA signed header)

TitleID.LSW should match DSi cart header (or be reverse of NDS gamecode?)
TitleID.MSW should match DSi cart header (or be zero for NDS titles?)
Note: Many titles do create the above structure even when not requesting to boot a new file: with NewTitleID=0=none & flags=13h=cartridge (in that case flags should be ignored, and NewTitleID=0=none has priority).
2000800h - Unlaunch Auto-load feature (via "device:/Path/Filename.ext")

      2000800h 12   Unlaunch Auto-load ID ("AutoLoadInfo")
      200080Ch 2    Unlaunch Length for CRC16 (fixed, must be 3F0h)
      200080Eh 2    Unlaunch CRC16 (across 2000810h..2000BFFh, initial value FFFFh)
      2000810h 4    Unlaunch Flags
      2000814h 2    Unlaunch Upper screen BG color (0..7FFFh)
      2000816h 2    Unlaunch Lower screen BG color (0..7FFFh)
      2000818h 20h  Unlaunch Reserved (zero)
      2000838h 208h Unlaunch Device:/Path/Filename.ext (16bit Unicode,end by 0000h)
      2000A40h 1C0h Unlaunch Reserved (zero)

Unlaunch Flags (usually 01h):

      0    Load the title at 2000838h
      1    Use colors 2000814h (use if loaded title is KNOWN to use such colors)
      2-31 Reserved (zero)

The name can use slashes or backslashes for folders, and it can use both long or short filenames (LFN or 8.3). The total length should not exceed 260 characters including EOL (alike windows MAX_PATH, although WinNT seems to allow up to 32K characters, which isn't supported here).

      "nand:/path/name.ext",0000h   File on 1st partition of internal eMMC
      "sdmc:/path/name.ext",0000h   File on 1st partition of external SD/MMC
      "cart:",0000h      ROM cartridge (in NDS cartridge slot)
      "menu:",0000h      Force starting unlaunch filemenu
      "sett:",0000h      Force starting unlaunch options menu
      "wifi:",0000h      Force starting unlaunch wifiboot overlay

Case-sensitivity: device, path and file can use upper/lower case A-Z (not case-sensititive), however currently any other letters are case-sensitive (eg. umlaut's or accented letters) (that is, they must be uppercase for short names, or have matching case for long names).
For black colors, you should also disable backlights before issuing reset (else screen will flash white for a short moment during initial forced blank; before unlaunch gets started).
2FFD800h - Title List
Before autoloading a title, one should make sure that the title is actually installed (and which region code it is having, ie. one should use wildcards that ignore the lower 8bit of the Title ID when searching the title).
The offical way is to look up the Title List in RAM, this is faster than manually crawling the directory tree. However, there are some restrictions: The Title List contains only titles from the same Maker (as the currently loaded title), plus some special "jumpable" system titles.

      2FFD800h 1     Titles: Number of titles in below lists (max 76h)
      2FFD801h 0Fh   Titles: Zerofilled
      2FFD810h 10h   Titles: Pub Flags (1bit each) ;same maker plus public.sav
      2FFD820h 10h   Titles: Prv Flags (1bit each) ;same maker plus private.sav
      2FFD830h 10h   Titles: Jmp Flags (1bit each) ;jumpable or current-title
      2FFD840h 10h   Titles: Mkr Flags (1bit each) ;same maker
      2FFD850h 3B0h  Titles: Title IDs (8 bytes each)

Related carthdr entries are:

      [010h].bit0-15  Maker (must match current title for Mkr Flags)
      [01Dh].bir0     Jump (must be set for Jmp Flags)
      [230h].bit0-63  Title ID (must be nonzero for being listed)
      [238h].bit0-31  Public.sav size (must be nonzero for Pub Flags)
      [23Ch].bit0-31  Private.sav size (must be nonzero for Prv Flags)

The list can contain the hidden Nintendo Zone utility, and DSi ROM cartridges (both provided that Maker does match up with current title).
The jumpable titles with [01Dh].bit0 that are always in the list are:

      00030015484E42xxh  ;System Settings
      00030005484E4441h  ;DS Download Play
      00030005484E4541h  ;Pictochat
      00030004484E47xxh  ;Nintendo DSi Browser (if installed)

The list does NOT contain the Launcher itself, nor files from System Data folder (WifiFirmware, Whitelist, VersionData), nor NDS ROM cartridges, nor anything where Jmp+Mkr flags would be both zero.
If started via 2000300h, then the New Title (from 2000310h) does also receive the the Old Title ID (from 2000308h) with Jmp flag being set; ie. permitting to return to the Old Title (to know which title was the old title, one should probably look at 2000000h, or at 2000308h if that's still intact in memory?).
Also, the Jmp flag is always set for the current title; ie. permitting the title to reboot itself.

DSi Aptina Camera Initialization

Aptina I2C registers are accessed via 16bit index, and one or more data bytes at auto-increasing indices (usually, all transfers are done as big-endian 2-byte (16bit) values at even indices). Additional MCU Variables are accessed indirectly via XMDA registers.
aptina_get_chip_id:
Reading a 16bit value from index 0000h returns the CHIP_VERSION_REG (always 2280h=MT9V113 for DSi/3DS/New3DS), the DSi games are actually reading that register, but they seem to ignore it's value.
If the DSi isn't fitted with Aptina cameras, then reading anything from device 78h/7Ah would most likely return FFh-bytes.
brightness / low light environments
Below configurations are okay for daylight (without much sunshine), but the picture will be almost completely black at night (in rooms with small bulbs). There are probably numerous good/bad ways to manipulate the brightness. Some random solutions are:
Leave AE_MIN_INDEX/AE_MAX_INDEX at their power-on defaults (instead of using below settings) (the power-on defaults will greatly improve the brightness, but the conversion will be also much slower). Increasing COARSE_INTEGRATION_TIME to some big value (like 0800h) does also seem to raise the brightness.
aptina_code_list_init:
Below is some minimal initialization (though it might still include some unnecessary stuff). Most important sections are leaving standby mode, matching PLL to DSi timings, selecting desired resolution(s) and YUV color format.
DSi games are usually initializing further stuff like P0..P4 Coefficients, Gamma Tables, and Color Correction Matrices - but the cameras are also working when leaving those settings at their power-on defaults.
It's recommended to initialize both cameras in parallel (eg. issue Wakeup to <both> cameras, and <then> wait for Wakeup completion; this is faster than doing it separately for each camera).

      AptWr     ,0001Ah,00003h   ;RESET_AND_MISC_CONTROL (issue reset)   ;\reset
      AptWr     ,0001Ah,00000h   ;RESET_AND_MISC_CONTROL (release reset) ;/
      AptWr     ,00018h,04028h   ;STANDBY_CONTROL (wakeup)               ;\
      AptWr     ,0001Eh,00201h   ;PAD_SLEW                               ; wakeup
      AptWr     ,00016h,042DFh   ;CLOCKS_CONTROL                         ;
      AptWaitClr,00018h,04000h   ;STANDBY_CONTROL (wait for WakeupDone)  ;
      AptWaitSet,0301Ah,00004h   ;UNDOC_CORE_301A (wait for WakeupDone)  ;/
      AptWrMcu  ,002F0h,00000h   ;UNDOC! RAM?
      AptWrMcu  ,002F2h,00210h   ;UNDOC! RAM?
      AptWrMcu  ,002F4h,0001Ah   ;UNDOC! RAM?
      AptWrMcu  ,02145h,002F4h   ;UNDOC! SEQ?
      AptWrMcu  ,0A134h,  001h   ;UNDOC! SEQ?
      AptSetMcu ,0A115h,  002h   ;SEQ_CAP_MODE (set bit1=video)
      AptWrMcu  ,02755h,00002h   ;MODE_OUTPUT_FORMAT_A (bit5=0=YUV)      ;\select
      AptWrMcu  ,02757h,00002h   ;MODE_OUTPUT_FORMAT_B                   ;/YUV mode
      AptWr     ,00014h,02145h   ;PLL_CONTROL                            ;\
      AptWr     ,00010h,00111h   ;PLL_DIVIDERS                           ; match
      AptWr     ,00012h,00000h   ;PLL_P_DIVIDERS                         ; PLL
      AptWr     ,00014h,0244Bh   ;PLL_CONTROL                            ; to DSi
      AptWr     ,00014h,0304Bh   ;PLL_CONTROL                            ; timings
      AptWaitSet,00014h,08000h   ;PLL_CONTROL (wait for PLL Lock okay)   ;
      AptClr    ,00014h,00001h   ;PLL_CONTROL (disable PLL Bypass)       ;/
      AptWrMcu  ,02703h,00100h   ;MODE_OUTPUT_WIDTH_A              ;\Size A
      AptWrMcu  ,02705h,000C0h   ;MODE_OUTPUT_HEIGHT_A             ;/ 256x192
      AptWrMcu  ,02707h,00280h   ;MODE_OUTPUT_WIDTH_B              ;\Size B
      AptWrMcu  ,02709h,001E0h   ;MODE_OUTPUT_HEIGHT_B             ;/ 640x480
      AptWrMcu  ,02715h,00001h   ;MODE_SENSOR_ROW_SPEED_A          ;\
      AptWrMcu  ,02719h,0001Ah   ;MODE_SENSOR_FINE_CORRECTION_A    ;
      AptWrMcu  ,0271Bh,0006Bh   ;MODE_SENSOR_FINE_IT_MIN_A        ; Sensor A
      AptWrMcu  ,0271Dh,0006Bh   ;MODE_SENSOR_FINE_IT_MAX_MARGIN_A ;
      AptWrMcu  ,0271Fh,002C0h   ;MODE_SENSOR_FRAME_LENGTH_A       ;
      AptWrMcu  ,02721h,0034Bh   ;MODE_SENSOR_LINE_LENGTH_PCK_A    ;/
      AptWrMcu  ,0A20Bh,  000h   ;AE_MIN_INDEX                     ;\AE min/max
      AptWrMcu  ,0A20Ch,  006h   ;AE_MAX_INDEX                     ;/
      AptWrMcu  ,0272Bh,00001h   ;MODE_SENSOR_ROW_SPEED_B          ;\
      AptWrMcu  ,0272Fh,0001Ah   ;MODE_SENSOR_FINE_CORRECTION_B    ;
      AptWrMcu  ,02731h,0006Bh   ;MODE_SENSOR_FINE_IT_MIN_B        ; Sensor B
      AptWrMcu  ,02733h,0006Bh   ;MODE_SENSOR_FINE_IT_MAX_MARGIN_B ;
      AptWrMcu  ,02735h,002C0h   ;MODE_SENSOR_FRAME_LENGTH_B       ;
      AptWrMcu  ,02737h,0034Bh   ;MODE_SENSOR_LINE_LENGTH_PCK_B    ;/
      AptSet    ,03210h,00008h   ;COLOR_PIPELINE_CONTROL (PGA pixel shading..)
      AptWrMcu  ,0A208h,  000h   ;UNDOC! RESERVED_AE_08
      AptWrMcu  ,0A24Ch,  020h   ;AE_TARGETBUFFERSPEED
      AptWrMcu  ,0A24Fh,  070h   ;AE_BASETARGET
      If Device=7Ah                                                ;\
        AptWrMcu,02717h,00024h   ;MODE_SENSOR_READ_MODE_A          ; Read Mode
        AptWrMcu,0272Dh,00024h   ;MODE_SENSOR_READ_MODE_B          ; with x-flip
      Else (xflip)                                                 ; on internal
        AptWrMcu,02717h,00025h   ;MODE_SENSOR_READ_MODE_A          ; camera
        AptWrMcu,0272Dh,00025h   ;MODE_SENSOR_READ_MODE_B          ;/
      If Device=7Ah                                                ;\
        AptWrMcu,0A202h,  022h   ;AE_WINDOW_POS                    ;
        AptWrMcu,0A203h,  0BBh   ;AE_WINDOW_SIZE                   ;
      Else (?)                                                     ;
        AptWrMcu,0A202h,  000h   ;AE_WINDOW_POS                    ;
        AptWrMcu,0A203h,  0FFh   ;AE_WINDOW_SIZE                   ;/
      AptSet    ,00016h,00020h   ;CLOCKS_CONTROL (set bit5=1, reserved)
      AptWrMcu  ,0A115h,  072h   ;SEQ_CAP_MODE (was already manipulated above)
      AptWrMcu  ,0A11Fh,  001h   ;SEQ_PREVIEW_1_AWB                ;\
      If Device=7Ah                                                ;
        AptWr   ,0326Ch,00900h   ;APERTURE_PARAMETERS              ;
        AptWrMcu,0AB22h,  001h   ;HG_LL_APCORR1                    ;
      Else (?)                                                     ;
        AptWr   ,0326Ch,01000h   ;APERTURE_PARAMETERS              ;
        AptWrMcu,0AB22h,  002h   ;HG_LL_APCORR1                    ;/
      AptWrMcu     ,0A103h,  006h   ;SEQ_CMD (06h=RefreshMode)
      AptWaitMcuClr,0A103h,  00Fh   ;SEQ_CMD (wait above to become ZERO)
      AptWrMcu     ,0A103h,  005h   ;SEQ_CMD (05h=Refresh)
      AptWaitMcuClr,0A103h,  00Fh   ;SEQ_CMD (wait above to become ZERO)

Above does set two Mode/Contexts, 256x192 and 640x480. Yet unknown how to activate the latter one.
aptina_code_list_activate:

      AptClr    ,00018h,00001h   ;STANDBY_CONTROL (bit0=0=wakeup)       ;\
      AptWaitClr,00018h,04000h   ;STANDBY_CONTROL (wait for WakeupDone) ; Wakeup
      AptWaitSet,0301Ah,00004h   ;UNDOC_CORE_301A (wait for WakeupDone) ;/
      AptWr     ,03012h,000xxh   ;COARSE_INTEGRATION_TIME (Y Time)
      AptSet    ,0001Ah,00200h   ;RESET_AND_MISC_CONTROL (Parallel On)  ;-Data on

Also, don't forget to activate the Camera LED via BPTWL chip (when using the external camera).
aptina_code_list_deactivate:
Before activating another camera: First disable the Parallel output of the old camera (for avoiding collisions on the camera's parallel databus). When not using the camera for longer time, also enter standby mode (for reducing power consumption).

      AptClr    ,0001Ah,00200h  ;RESET_AND_MISC_CONTROL (Parallel Off)  ;-Data off
      AptSet    ,00018h,00001h  ;STANDBY_CONTROL (set bit0=1=Standby)   ;\
      AptWaitSet,00018h,04000h  ;STANDBY_CONTROL (wait for StandbyDone) ; Standby
      AptWaitClr,0301Ah,00004h  ;UNDOC_CORE_301A (wait for StandbyDone) ;/

References
There aren't any MT9V113 specs released, but info for MT9D113 (a higher resolution variant) does exist: a pdf datasheet, and an xml reference for the I2C registers.
There are several source code files for MT9V113 cameras (different files from different people; for use with linux/android/whatever) including samples for adjusting stuff like contrast and sharpness. However, observe that the source code may need some adjustments: PLL register matched to DSi timings, and, use YUV 8bit parallel databus transfer for DSi.

DSi Aptina Camera Registers: SYSCTL (0000h-0051h)

SYSCTL (0000h-0051h)

      0000h   2  CHIP_VERSION_REG       Model ID (2280h=MT9V113 on DSi/3DS) (R)
      0006h  ..  RESERVED_SYSCTL_06     Reserved
      0010h   2  PLL_DIVIDERS           PLL Dividers (def=0366h)
                   0-7   PLL M-Divider value (uh, actually a Multiplier?!)
                   8-13  PLL N-Divider value
                   14-15 Unused (0)
                 Because the input clock frequency is unknown, the sensor starts
                 up with the PLL disabled. The PLL takes time to power up. During
                 this time, the behavior of its output clock signal is not
                 guaranteed. The PLL output frequency is determined by two
                 constants, M and N, and the input clock frequency.
                   VCO = Fin * 2 * M / (N+1)
                   PLL_output_frequency = VCO / (P1+1)
                 The PLL can generate a master clock signal whose frequency is up
                 to 85 MHz (input clock from 6 MHz through 54 MHz).
      0012h   2  PLL_P_DIVIDERS         PLL P Dividers (def=00F5h)
                   0-3   P1 (00h..0Fh)
                   4-7   Unspecified
                   8-11  P3 (00h..0Fh)
                   12-13 Division ratio of word clock/clockn from bit_clock (0..3)
                   14    Unused (0)
                   15    Unspecified
      0014h   2  PLL_CONTROL            PLL Control (def=21F9h)
                   0     PLL Bypass
                   1     PLL Enable
                   2-3   Reserved (0..3)
                   4-7   Reserved (0..0Fh)
                   8     Reset_cntr
                   9     Reserved
                   10    Reserved
                   11    Reserved
                   12    Reserved
                   13    Reserved
                   14    Unused (0)
                   15    PLL Lock (R)
      0016h   2  CLOCKS_CONTROL         Clocks Control
                   0     Reserved
                   1     Reserved
                   2     Reserved
                   3     Reserved
                   4     Reserved
                   5     Reserved/UNDOC/USED (manipulated by DSi)
                   6     Reserved
                   7     Reserved
                   8     Reserved
                   9     clk_clkin_en
                   11-12 Reserved
                   13    Reserved
                   15    Reserved
      0018h   2  STANDBY_CONTROL        Standby Control and Status (def=4029h)
                   0     Ship (uh?) (0=Enable various regs, 1=Standby)
                   1     Reserved
                   2     Stop MCU
                   3     en_IRQ
                   4     Reserved
                   5     Reserved
                   6-13  Unused (0)
                   14    Standby_done (0=WakeupDone, 1=StandbyDone) (R?)
                           (takes MUCH time?)
                   15    Reserved (R)
      001Ah   2  RESET_AND_MISC_CONTROL Reset and Control (def=0050h) (0-0333h)
                   0     Reset SOC I2C
                   1     MIPI_TX_Reset
                   2     Unused (0)
                   3     MIPI_TX_en       (=Serial Data?)
                   4     IP_PD_en         (=Parallel Data or what?)
                   5     Reserved
                   6     Sensor_full_res
                   7     Unused (0)
                   8     OE_N_Enable
                   9     Parallel_enable  (=Parallel Data?)
                   10    Unused (0)
                   11    Reserved
                   12-15 Unused (0)
      001Ch   2  MCU_BOOT_MODE          MCU Boot Mode
                   0     Reset MCU
                   1     Reserved
                   2     Reserved
                   3     Reserved
                   4-7   Reserved  (0..0Fh)
                   8-15  Reserved  (0..FFh) (R)
      001Eh   2  PAD_SLEW               Pad Slew Control (def=0400h)
                   0-2   Parallel Data Output Slew Rate Control (0-7)
                   3     Unused (0)
                   4-6   GPIO Slew Rate Control (0-7)
                   7     Unused (0)
                   8-10  PCLK aka PXLCLK Slew Rate Control (0-7)
                   11-15 Unused (0)
      0020h  ..  RESERVED_SYSCTL_20     Reserved
      0022h   2  VDD_DIS_COUNTER        VDD_DIS_COUNTER (0..FFFFh, def=0438h)
      0024h   2  GPI_STATUS             GPI_STATUS      (0..000Fh) (R)
      0026h  ..  RESERVED_SYSCTL_26     Reserved
      0028h   2  EN_VDD_DIS_SOFT        EN_VDD_DIS_SOFT (0..0001h, def=0001h)
      0050h  ..  RESERVED_SYSCTL_50     Reserved

DSi Aptina Camera Registers: RX_SS, FUSE, XDMA (0100h-099Fh)

RX_SS (0100h-0117h)

      0100h  ..  RESERVED_RX_SS_100     Reserved
      0102h   2  TEST_PXL_RED           Test Pixel Red    ;\Default value is 1FFh
      0104h   2  TEST_PXL_G1            Test Pixel Green1 ; for Gray Flat Field
      0106h   2  TEST_PXL_G2            Test Pixel Green2 ; (0..03FFh, def=01FFh)
      0108h   2  TEST_PXL_BLUE          Test Pixel Blue   ;/
      010Ah  ..  RESERVED_RX_SS_10A-116 Reserved

FUSE_ROM (0800h-081Fh)
Reserved, unknown purpose, all zero in DSi.

      0800h  ..  RESERVED_FUSE_ROM_800-81E  Reserved

XDMA (0982h-099Fh)
Access to internal LOGICAL "driver" variables.

      0982h  ..  RESERVED_XDMA_982      Reserved
      098Ch   2  MCU_ADDRESS            MCU Address (0000h..FFFFh)
                   0-7   driver_variable (0..FFh)
                   8-12  driver_id       (0..1Fh) (eg. 3=AWB, 7=MODE, etc.)
                   13-14 address space   (0=Physical/RAM/SFR, 1=Logical/Variables)
                   15    access_8_bit    (0=16bit, 1=8bit; converted to 16bit)
      0990h 8x2  MCU_DATA_0-7           MCU Data 0..7 (8 x 16bit)

For reading, it's best to use "16bit" mode, no matter if reading an 8bit BYTE, or a 16bit MSB,LSB value. The "8bit" mode is converting bytes to 16bit values (MSB=00h, LSB=BYTE), which is a rather contraproductive idiotism; intended for I2C functions that implement only 16bit data transfers, but no 8bit transfers.
Unknown what exactly is mapped at MCU_DATA_0-7 (probably the 16 bytes at MCU_ADDRESS+0..15, probably with direct mapping / ie. without latching a copy of that memory).
MCU_ADDRESS doesn't seem to increment after reading data, however, the i2c index does increase, so one can probably read up to 16 bytes from MCU_DATA_0-7.

DSi Aptina Camera Registers: CORE (3000h-31FFh, 38xxh)

CORE (3000h-31FFh)

      3000h  ..  RESERVED_CORE_3000        Reserved (same as CHIP_VERSION_REG)
      3002h   2  Y_ADDR_START              Y1      ;\Image Position/Size ;def=0004h
      3004h   2  X_ADDR_START              X1      ; (up to including    ;def=0004h
      3006h   2  Y_ADDR_END                Y2      ; X2,Y2) (0-07FFh)    ;def=04BBh
      3008h   2  X_ADDR_END                X2      ;/                    ;def=064Bh
      300Ah   2  FRAME_LENGTH_LINES        Y Total ;\Total X/Y Size with ;def=0512h
      300Ch   2  LINE_LENGTH_PCK           X Total ;/blanking (0..FFFFh) ;def=0886h
      3010h  ..  RESERVED_CORE_3010        Reserved
      3012h   2  COARSE_INTEGRATION_TIME   Y Time  ;\Integration Time in ;def=0010h
      3014h   2  FINE_INTEGRATION_TIME     X Time  ;/lines/pix (0..FFFFh);def=00F6h
      3016h   2  ROW_SPEED                 Row Speed (def=0111h)
                   0-2   Pixclk_speed (0..7)
                   3     Unused (0)
                   4-6   Reserved
                   7     Unused (0)
                   8-10  Reserved
                   11-15 Unused (0)
      3018h  ..  RESERVED_CORE_3018-3019   Reserved
      301Ah      UNDOC_CORE_301A           Undocumented Status Reg (mask=D7FFh)
                   0-1   Unspecified
                   2     Undoc/USED (1=WakeupDone) (opposite of 0018h.bit14)
                   3-4   Unspecified
                   5     Whatever "demo_system, version_reg_write, value=1"
                   6-8   Unspecified
                   9     Mask_corrupted_frames     (alias of 3022h.bit0)
                   10    Unspecified
                   11    Unused (0)
                   12    Unspecified
                   13    Unused (0)
                   14    Unspecified
                   15    Grouped_parameter_hold    (alias of 3022h.bit8)
      301Ch  ..  RESERVED_CORE_301C-3020   Reserved
      3022h   2  GROUPED_PARAMETER_HOLD_MASK_CORRUPTED_FRAMES
                   0     Mask_corrupted_frames  (alias of Reg 301Ah.bit9)
                   1-7   Unused (0)
                   8     Grouped_parameter_hold (alias of Reg 301Ah.bit15)
                   9-15  Unused (0)
      3024h   2  PIXEL_ORDER                Pixel Order (mask=0300h, 0..0300h) (R)
      3026h  ..  RESERVED_CORE_3026         Reserved
      3028h   2  ANALOGUE_GAIN_CODE_GLOBAL  Analog Global   ;\
      302Ah   2  ANALOGUE_GAIN_CODE_GREENR  Analog GreenR   ; Analogue Gain Codes
      302Ch   2  ANALOGUE_GAIN_CODE_RED     Analog Red      ; with 3bit fraction
      302Eh   2  ANALOGUE_GAIN_CODE_BLUE    Analog Blue     ; (0..007Fh, def=000Bh)
      3030h   2  ANALOGUE_GAIN_CODE_GREENB  Analog GreenB   ;/
      3032h   2  DIGITAL_GAIN_GREENR        Digital GreenR  ;\Digital Gain with
      3034h   2  DIGITAL_GAIN_RED           Digital Red     ; 8bit dummy-fraction
      3036h   2  DIGITAL_GAIN_BLUE          Digital Blue    ; (bit8-10=Gain, 0..7)
      3038h   2  DIGITAL_GAIN_GREENB        Digital GreenB  ;/(mask=0700h,def=100h)
      303Ah  ..  RESERVED_CORE_303A-3C      Reserved
      3040h   2  READ_MODE                  Read Mode (0-DEFFh, def=0024h)
                   0    horiz_mirror
                   1    vert_flip
                   2-4  y_odd_inc (0..7)
                   5-7  x_odd_inc (0..7)
                   8    Unused (0)
                   9    low_power
                   10   xy_bin_en
                   11   x_bin_en
                   12   bin_sum (Enable summing mode for binning)
                   13   read_mode_y_sumen
                   14   Reserved
                   15   Reserved
      3044h  ..  RESERVED_CORE_3044-3048    Reserved
      304Ah   2  OTPM_CONTROL               One-time Programmable Memory? Control
                   0    auto_wr_start              ;\
                   1    auto_wr_end (finished) (R) ; automatic write sequence
                   2    auto_wr_success (okay) (R) ;/
                   3    unspecified
                   4    auto_rd_start              ;\
                   5    auto_rd_end (finished) (R) ; automatic read sequence
                   6    auto_rd_success (okay) (R) ;/
                   7-15 Unused (0)
      3050h  ..  RESERVED_CORE_3050-3054    Reserved
      3056h   2  GREEN1_GAIN                Gain Green1             ;\
      3058h   2  BLUE_GAIN                  Gain Blue               ; Gain Values
      305Ah   2  RED_GAIN                   Gain Red                ; (0..0FFFh,
      305Ch   2  GREEN2_GAIN                Gain Green2             ; def=022Ch)
                   0-6   Initial Gain (0..7Fh, with 5bit fraction)  ;
                   7-8   Analog Gain  (0..3)   (bit8+1)*(bit7+1)*(initial_gain/32)
                   9-11  Digital Gain (1..7)                        ;
                   12-15 Unused (0)                                 ;/
      305Eh  ..  RESERVED_CORE_305E-31DF    Reserved
      31E0h   2  UNDOC_CORE_31E0            (mask=E003h, 0..8001h, def=0001h) USED!
                   Used by DSi (set to 0001h) (reportedly "PIX_DEF_ID")
      31E2h  ..  RESERVED_CORE_31E2-31F9    Reserved
      31FAh   2  UNDOC_CORE_31FA            Whatever (mask=FFFFh, def=CDEFh)
                   0-4   Unspecified
                   5-11  Whatever "demo_system, version_reg_read, value=3"
                   12-15 Unspecified
      31FCh  ..  RESERVED_CORE_305E-31FE    Reserved

More CORE (3800h..3803h)

      3800h  ..  RESERVED_CORE_3800-3802   Reserved

DSi Aptina Camera Registers: SOC1 (3210h-33FDh)

SOC1 Registers (3210h-33FDh)

      3210h   2  COLOR_PIPELINE_CONTROL     (mask=05B8h, 0..05B0h, def=01B0h)
                   3   Enable PGA pixel shading correction
                         All coefficients and other configuration settings
                         (including other fields in this register) must be set up
                         before enabling shading correction.
                   4   Enable 2D aperture correction
                   5   Enable color correction
                   7   Enable gamma correction
                   8   Decimator (1=Enable scale)
                   10  Reserved
      3216h  ..  RESERVED_SOC1_3216-321A    Reserved
      321Ch   2  OFIFO_CONTROL_STATUS       Ofifo control status 1 (def=0003h)
                   0-3 txfifo_bypass
                         (0=tx_fifo, 1=sensor, 2=sam observe, 3=cpipe format,
                         4=test walking ones cpipe frequency,
                         5=test walking ones sensor frequency,
                         6=RESERVED, 7=test PIXCLK, 8..F=Unspecified)
                   4-6 Unused (0)
                   7   sensor_bypass (0=cpipe, 1=sensor)
                   8   Reserved
                   9   Reserved
                   10  Reserved
                   11  Reserved
                   12  Reserved (R)
                   13  Reserved (R)
                   14  Reserved (R)
                   15  Reserved (R)
      321Eh   2  OFIFO_CONTROL_STATUS_2     Ofifo control status 2 (def=0010h)
                   0-9   Reserved (0..3FFh)
                   10    Disable PV output clock during blank (1=disable)
                   11-15 Reserved (0..1Fh)
      3220h  ..  RESERVED_SOC1_3220         Reserved
      3222h   2  LOWER_X_BOUND_ZOOM_WINDOW  Lower X  ;def=?      ;\Zoom Window
      3224h   2  UPPER_X_BOUND_ZOOM_WINDOW  Upper X  ;def=063Fh  ; Boundaries
      3226h   2  LOWER_Y_BOUND_ZOOM_WINDOW  Lower Y  ;def=?      ; (0..07FFh)
      3228h   2  UPPER_Y_BOUND_ZOOM_WINDOW  Upper Y  ;def=04AFh  ;/
      322Ah   2  UNDOC_SOC1_322A            (mask=0016h, 0..0016h) USED by DSi!
      322Ch   2  WEIGHT_HORIZ_DECIMATION    Scaling Weight X ;\Scaling Weight X,Y
      322Eh   2  WEIGHT_VERTICAL_DECIMATION Scaling Weight Y ;/(0..0FFFh, def=800h)
      323Eh   2  UNDOC_SOC1_323E            (0..FFFFh, def=1A2Dh) (DSi: C22Ch)
      3240h   2  UNDOC_SOC1_3240            (0..FFFFh, def=C814h) (DSi: 6214h)
      3242h  ..  RESERVED_SOC1_3242         Reserved
      3244h   2  UNDOC_SOC1_3244            (mask=03FFh, range=0..00FFh?, def=0310)
      3254h  ..  RESERVED_SOC1_3254-326A    Reserved
      326Ch   2  APERTURE_PARAMETERS        Aperture Params (0..7FFFh, def=0A08h)
                   0-7   2D aperture threshold (knee) (00h-FFh)
                   8-10  2D aperture gain (0-7)
                   11-13 2D aperture gain's exponent (0-7)
                   14    Abs (1=force aperture gain be positive)
                   15    Unused (0)
      326Eh  ..  RESERVED_SOC1_326E-3276    Reserved
      327Ah   2  BLACK_LEVEL_1ST_RED        Offset Red     ;\Offsets subtracted
      327Ch   2  BLACK_LEVEL_1ST_GREEN1     Offset Green1  ; from RGB pixels
      327Eh   2  BLACK_LEVEL_1ST_GREEN2     Offset Green2  ; (0000-01FFh/03FFh,
      3280h   2  BLACK_LEVEL_1ST_BLUE       Offset Blue    ;/def=002Ah)
      328Eh   2  THRESH_EDGE_DETECT         Demosaic Edge Threshold (def=000Ch)
      3290h   2  TEST_PATTERN               Test Pattern Enable/Width
                   0-4   Unused (0)
                   5     en_walk_ones_tp  Enable Test Pattern (0=disable, 1=enable)
                   6     walk_ones_10     Pattern Width (0=8-bit, 1=10-bit)
                   7-15  Unused (0)
      329Eh  ..  RESERVED_SOC1_329E-32A0    Reserved
      32C0h   2  COLOR_CORR_MATRIX_SCALE_14 Exponents C11..C22 (0-7FFFh, def=3923h)
      32C2h   2  COLOR_CORR_MATRIX_SCALE_11 Exponents C23..C33 (0-0FFFh, def=0724h)
      32C4h   2  COLOR_CORR_MATRIX_1_2      Elements C11=LSB, C12=MSB   (def=7DCCh)
      32C6h   2  COLOR_CORR_MATRIX_3_4      Elements C13=LSB, C21=MSB   (def=2711h)
      32C8h   2  COLOR_CORR_MATRIX_5_6      Elements C22=LSB, C23=MSB   (def=62E5h)
      32CAh   2  COLOR_CORR_MATRIX_7_8      Elements C31=LSB, C32=MSB   (def=690Dh)
      32CCh   2  COLOR_CORR_MATRIX_9        Element C33=LSB, Signs=MSB  (def=2DCDh)
      32D4h   2  DIGITAL_GAIN_1_RED         Gain for Red channel    ;\Digital Gain1
      32D6h   2  DIGITAL_GAIN_1_GREEN1      Gain for Green1 channel ; (mul 128,
      32D8h   2  DIGITAL_GAIN_1_GREEN2      Gain for Green2 channel ; 0000h..03FFh,
      32DAh   2  DIGITAL_GAIN_1_BLUE        Gain for Blue channel   ;/def=0080h)
      32F4h  ..  RESERVED_SOC1_32F4-332E    Reserved
      3330h   2  OUTPUT_FORMAT_TEST         OUTPUT_FORMAT_TEST (0..0FFFh)
                   0     Disable Cr channel
                   1     Disable Y channel
                   2     Disable Cb channel
                   3-5   Test ramp output
                   6     8+2 bypass
                   7     Reserved
                   8     Enable Lens Correction Bypass
                   9     Reserved
                   10    Reserved
                   11    Reserved
                   12-15 Unused (0)
      3332h  ..  RESERVED_SOC1_3332-334A    Reserved
      337Ch   2  YUV_YCBCR_CONTROL          YUV_YCBCR_CONTROL (0..000Fh, def=0006h)
                   0     Mult_y_uv (normalize Y in 16-235; U and V in 16-240)
                   1     Coefficient control
                   2     Add 128 to U and V
                   3     Clip Y in 16-235; U and V in 16-240
                   4-15  Unused (0)
      337Eh   2  Y_RGB_OFFSET               Y_RGB Offset
                   0-7   Reserved (0..FFh)
                   8-15  Y offset (0..FFh)
      33E6h  ..  RESERVED_SOC1_33E6-33EE    Reserved
      33F4h   2  KERNEL_CONFIG              Kernel Config (0..01FFh, def=0003h)
                   0     Defect correction (DC) enable
                   1     Reserved
                   2     Reserved
                   3     Noise reduction (NR) enable
                   4     Reserved
                   5     Reserved
                   6     Reserved
                   7     Reserved
                   8     Reserved
      33F6h  ..  RESERVED_SOC1_33F6-33FC    Reserved

DSi Aptina Camera Registers: SOC2 (3400h-3729h)

SOC2 (3400h-3729h)

      3400h   2  MIPI_CONTROL              MIPI_Control (def=782Eh)
                   0     MIPI restart enable
                   1     MIPI standby
                   2     Continuous MIPI clock
                   3     Frame boundary sync bit (R)
                   4     Wait until eof to react to standby
                   5     Reserved
                   6-8   MIPI channel number
                   9     Unused (0) or Reserved (REV3)
                   10-15 Data Type (1Eh=YUV422_8bit, 20h=RGB444, 21h=RGB555,
                           22h=RGB565, 2Ah=RAW8, 2Bh=RAW10)
      3402h   2  MIPI_STATUS               MIPI_Status (def=0011h)
                   0     MIPI in standby (R)
                   1-3   Unused (0)
                   4     MIPI aka MIPICCP idle (R)
                   5     MIPI ready to receive data (R)
                   6-8   Unused (0)
                   9     Reserved (R)
                   10    Reserved (R)
                   11    Reserved
                   12    Reserved
                   13-15 Unused (0)
      3404h   2  CUSTOM_SHORT_PKT          MIPI_Custom_Short_Packet (0000h-3F00h)
                   0-5   Unused (0)
                   6     frame_cnt_reset (sent in frame start/end short packets)
                   7     frame_cnt_en (Insert frame counter value in WC field)
                   8-10  custom_short_packet_data_type
                   11    custom_short_packet_request
                   12    custom_short_packet_frame_sync
                   13    custom_short_packet_reset (R)
                   14-15 Unused (0)
      3408h   2  LINE_BYTE_CNT             MIPI line byte count (def=0C80h)
      340Ch   2  CUSTOM_SHORT_PKT_WC       WC field of a custom short packet
      340Eh  ..  RESERVED_SOC2_340E-341A   Reserved
      3580h   2  AE_ZONE_X                 AE Window/Zone X (def=1300h)
                   0-7:  ae_zone_x_start (00h..FFh) (div8)          ;for WINDOW
                   8-15: ae_zone_x_width (00h..FFh) (div8, minus 1) ;for each ZONE
      3582h   2  AE_ZONE_Y                 AE Window/Zone Y (def=0E00h)
                   0-7:  ae_zone_y_start (00h..FFh) (div8)          ;for WINDOW
                   8-15: ae_zone_y_width (00h..FFh) (div8, minus 1) ;for each ZONE
      3584h   2  AE_WINDOW_SIZE_LO         LSBs ;\Size of each AE zone in pixels
      3586h   2  AE_WINDOW_SIZE_HI         MSBs ;/(0..0001FFFFh, def=000x4B00h ?)
      3588h  ..  RESERVED_SOC2_3588-35AE   Reserved
      35B0h      UNDOC_SOC2_35B0           (mask=FFFFh, 0..FFFFh, def=05FAh) USED!
      35B2h  ..  RESERVED_SOC2_35B2-3602   Reserved
      3604h  20  R_GAMMA_CURVE_KNEES_0-18  Red Gamma Curve Knees 0..18   (1B00h,..)
      3618h  20  G_GAMMA_CURVE_KNEES_0-18  Green Gamma Curve Knees 0..18 (1B00h,..)
      362Ch  20  B_GAMMA_CURVE_KNEES_0-18  Blue Gamma Curve Knees 0..18  (1B00h,..)
                   Above 20-byte knees consist of ten 16bit values (Knee0 in LSB)
                   Due to the 16bit-big-endian format, the byte-order is:
                   Knee1,Knee0,Knee3,Knee2,...,Knee17,Knee16,UNUSED,Knee18
      3640h  ..  RESERVED_SOC2_3640        Reserved
      3642h   2  POLY_ORIGIN_R             Center Row    (max 07FFh, def=025Ch)
      3644h   2  POLY_ORIGIN_C             Center Column (max 07FFh, def=0324h)
      3646h  ..  RESERVED_SOC2_3646-364C   Reserved
      364Eh 5x2  P_GR_P0Q0-4               P0Q for Green1  ;\P0 Coefficients
      3658h 5x2  P_RD_P0Q0-4               P0Q for Red     ; (5 x float16 each)
      3662h 5x2  P_BL_P0Q0-4               P0Q for Blue    ; (0010h,... each)
      366Ch 5x2  P_GB_P0Q0-4               P0Q for Green2  ;/
      3676h 5x2  P_GR_P1Q0-4               P1Q for Green1  ;\
      3680h 5x2  P_RD_P1Q0-4               P1Q for Red     ; P1 Coefficients
      368Ah 5x2  P_BL_P1Q0-4               P1Q for Blue    ; (5 x float16 each)
      3694h 5x2  P_GB_P1Q0-4               P1Q for Green2  ;/
      369Eh 5x2  P_GR_P2Q0-4               P2Q for Green1  ;\
      36A8h 5x2  P_RD_P2Q0-4               P2Q for Red     ; P2 Coefficients
      36B2h 5x2  P_BL_P2Q0-4               P2Q for Blue    ; (5 x float16 each)
      36BCh 5x2  P_GB_P2Q0-4               P2Q for Green2  ;/
      36C6h 5x2  P_GR_P3Q0-4               P3Q for Green1  ;\
      36D0h 5x2  P_RD_P3Q0-4               P3Q for Red     ; P3 Coefficients
      36DAh 5x2  P_BL_P3Q0-4               P3Q for Blue    ; (5 x float16 each)
      36E4h 5x2  P_GB_P3Q0-4               P3Q for Green2  ;/
      36EEh 5x2  P_GR_P4Q0-4               P4Q for Green1  ;\
      36F8h 5x2  P_RD_P4Q0-4               P4Q for Red     ; P4 Coefficients
      3702h 5x2  P_BL_P4Q0-4               P4Q for Blue    ; (5 x float16 each)
      370Ch 5x2  P_GB_P4Q0-4               P4Q for Green2  ;/
      3716h  ..  RESERVED_SOC2_3716-3278   Reserved

DSi Aptina Camera Variables: RAM/SFR/MON (GPIO/Monitor) (MCU:0000h-20xxh)

Internal RAM (MCU:0000h..0xxxh)
Internal RAM is reserved for whatever internal purposes (probably including for storing the 'logical variables' at MCU:2xxxh at some physical memory locations at MCU:0xxxh). However, some of those undocumented reserved RAM cells are manipulated by DSi games:

      02F0h   2  UNDOC_RAM_02F0   (set to 0000h by DSi games)
      02F2h   2  UNDOC_RAM_02F2   (set to 0210h by DSi games)
      02F4h   2  UNDOC_RAM_02F4   (set to 001Ah by DSi games)

Exact RAM Size is unknown (around 2Kbyte or so)? Some Aptina chips do also contain some sort of User RAM (at 0800h or so) for unknown purpose (just general purpose storage maybe). Unknown if the DSi chips are having any such User RAM.
Special Function Registers SFR (MCU:1040h..10FEh)

      1040h  ..  RESERVED_SFR_1040-1050    Reserved
      1060h  ..  RESERVED_SFR_1060-1066    Reserved (REV3)
      1070h   2  GPIO_DATA                 GPIO Data  (0..1E00h)
                   0-8   Unused (0)
                   9-12  gpio_3_0_data
                   13-15 Unused (0)
      1072h   2  RESERVED_SFR_1072         Reserved
      1074h   2  GPIO_OUTPUT_SET           GPIO Set   (0..0C00h/1E00h?) (W)
                   0-8   Unused (0)
                   9-12  gpio_3_0_output_toggle (uh, toggle or set?)
                   13-15 Unused (0)
      1076h   2  GPIO_OUTPUT_CLEAR         GPIO Clear (0..0C00h/1E00h?) (W)
                   0-8   Unused (0)
                   9-12  gpio_3_0_output_clear
                   13-15 Unused (0)
      1078h   2  GPIO_DIR                  GPIO Direction (0..1E00h, def=1E00h)
                   0-8   Unused (0)
                   9     gpio_0_dir (0=Output, 1=Input) ;(LSB0 of 10bit Output)
                   10    gpio_1_dir (0=Output, 1=Input) ;(LSB1 of 10bit Output)
                   11    gpio_2_dir (0=Output, 1=Input) ;(Flash/Shutter Pulse)
                   12    gpio_3_dir (0=Output, 1=Input) ;(OE_BAR for Databus)
                   13-15 Unused (0)
      107Ah  ..  RESERVED_SFR_107A-10FD    Reserved

Monitor Variables MON (MCU:2000h..2025h)

      2000h   5  RESERVED_MON_00-04        Reserved
      2005h   1  MON_CMD                   Monitor Command (0..FFh)
      2006h   2  MON_ARG1                  Monitor First Argument (0..FFFFh)
      2008h  ..  RESERVED_MON_08-22        Reserved
      2024h   2  MON_PATCH_ID_0            Monitor First Patch (0..FFFFh) (REV1)
                   0-7   mon_patch_0_version (00h-0Fh)
                           The version number of the first patch (R)
                   8-15  mon_patch_0_number  (00h-0Fh)
                           Identifies which patch the first patch is (R)
      2024h   1  MON_PATCH_ID_0            (mask=FFh) (R) ;\unlike above  (REV3)
      2025h   1  MON_PATCH_ID_1            (0..FF)        ;/REV1 specs    (REV3)
      2026h   1  MON_PATCH_ID_2            (0..FF)                        (REV3)
      2027h   1  RESERVED_MON_27           Reserved                       (REV3)

DSi Aptina Camera Variables: SEQ (Sequencer) (MCU:21xxh)

Sequencer Variables SEQ (MCU:2100h..215Ah)

      2100h  ..  RESERVED_SEQ_00           Reserved
      2102h   1  SEQ_MODE                  SEQ Mode (enables "drivers") (def=0Fh)
                   0    Enable AE   (ID=2)
                   1    Enable FD   (ID=4)
                   2    Enable AWB  (ID=3)
                   3    Enable HG   (ID=11)
                   4-7  Unspecified
      2103h   1  SEQ_CMD                   SEQ Cmd   (0..FFh, def=01h)
                   0-7  Cmd   (0=Run, 1=Preview, 2=Capture, 3=Standby,
                              4=Lock, 5=Refresh, 6=Refresh Mode)
      2104h   1  SEQ_STATE                 SEQ State (0..FFh)
                   0-7  State (0=Run, 1=ToPreview, 2=Enter, 3=Preview
                               4=Leave, 5=ToCapture, 6=Enter, 7=Capture,
                               8=Leave, 9=Standby)
      2105h  ..  RESERVED_SEQ_05           Reserved
      2106h   1  SEQ_FLASHTYPE             Type of flash to be used
                   0-6 Flash Type (0=None, 1=LED, 2=Xenon, 3=XenonBurst)
                   7   Set flash to LOCK mode (0=Normal, 1=LOCK mode)
      2107h  ..  RESERVED_SEQ_07-08        Reserved
      2109h   1  SEQ_AE_FASTBUFF           AE Fast Buff  (0..FFh, def=10h)
      210Ah   1  SEQ_AE_FASTSTEP           AE Fast Step  (0..FFh, def=02h)
      210Bh   1  SEQ_AWB_CONTBUFF          AWB Cont Buff (0..FFh, def=08h)
      210Ch   1  SEQ_AWB_CONTSTEP          AWB Cont Step (0..FFh, def=02h)
      210Dh  ..  RESERVED_SEQ_0D-10        Reserved
      2111h   1  SEQ_OPTIONS               SEQ Options (0..FFh, def=08h)
                   0  Reserved
                   1  Reserved
                   2  Reserved
                   3  seq_crop_win_ae, Use crop window for AE statistics
                   4  seq_crop_win_awb, Use crop window for AWB statistics
                   7  Reserved
      2112h  ..  RESERVED_SEQ_12           Reserved
      2113h   2  SEQ_FLASH_TH              SEQ Flash TH (0..FFFFh)
      2115h   1  SEQ_CAP_MODE              Capture mode (in Capture state only)
                   0  Xenon Flash (Still Only)
                   1  Video
                   2  Turn Flash off before last frame in capture state
                   4  Video AE on
                   5  Video AWB on
                   6  Video HG on
      2116h   1  SEQ_CAP_NUMFRAMES         Num still frames captured (0..FFh,def=3)
      2117h   1  SEQ_PREVIEW_0_AE          Preview 0 AE (PREVIEW ENTER)     ;\
                   0-3  AE (0=Off, 1=Fast, 2=Manual, 3=Continuous, 4=MDR)   ;
                   4-7  Unspecified (0..5) (0..0Fh for PREVIEW_2/3)         ; Pre-
      2118h   1  SEQ_PREVIEW_0_FD          Preview 0 FD (PREVIEW ENTER)     ; view
                   0-7  FD (0=Off, 1=Continuous, 2=Manual)                  ; 0
      2119h   1  SEQ_PREVIEW_0_AWB         Preview 0 AWB (PREVIEW ENTER)    ;
                   0-7  AWB (0=Off, 1=On)                                   ; PRE-
      211Ah   1  SEQ_PREVIEW_0_HG          Preview 0 HG (PREVIEW ENTER)     ; VIEW
                   0-7  HG (0=Off, 1=Fast, 2=Manual, 3=Continuous)          ; ENTER
      211Bh   1  SEQ_PREVIEW_0_FLASH       Flash Config (0..FFh)            ;
                   0-6 Flash (0=Off,1=On,2=Locked,3=AutoEvaluate,7=UserDef) ;
                   7   Reserved                                             ;
      211Ch   1  SEQ_PREVIEW_0_SKIPFRAME   Skipframe State Config (def=40h) ;
                   0-3 Unspecified                                          ;
                   4   Unspecified (except PREVIEW_2: Reserved)             ;
                   5   Skip_led_on                                          ;
                   6   Skip_state (0=No skip state, 1=Skip state)           ;
                   7   Turn_off_fen                                         ;/
      211Dh   1  SEQ_PREVIEW_1_AE            ;\                             def=01h
      211Eh   1  SEQ_PREVIEW_1_FD            ; Preview 1 (PREVIEW)          def=01h
      211Fh   1  SEQ_PREVIEW_1_AWB           ; (same as Preview 0, but      def=01h
      2120h   1  SEQ_PREVIEW_1_HG            ; without AE=MDR,              def=01h
      2121h   1  SEQ_PREVIEW_1_FLASH         ; without HG=Manual/Continous)
      2122h   1  SEQ_PREVIEW_1_SKIPFRAME     ;/                             def=N/A
      2123h   1  SEQ_PREVIEW_2_AE            ;\
      2124h   1  SEQ_PREVIEW_2_FD            ; Preview 2 (PREVIEW LEAVE)
      2125h   1  SEQ_PREVIEW_2_AWB           ; (same as Preview 0, but
      2126h   1  SEQ_PREVIEW_2_HG            ; without HG=Manual/Continous)
      2127h   1  SEQ_PREVIEW_2_FLASH         ;
      2128h   1  SEQ_PREVIEW_2_SKIPFRAME     ;/
      2129h   1  SEQ_PREVIEW_3_AE            ;\
      212Ah   1  SEQ_PREVIEW_3_FD            ; Preview 3 (CAPTURE ENTER)
      212Bh   1  SEQ_PREVIEW_3_AWB           ; (same as Preview 0)
      212Ch   1  SEQ_PREVIEW_3_HG            ;
      212Dh   1  SEQ_PREVIEW_3_FLASH         ;
      212Eh   1  SEQ_PREVIEW_3_SKIPFRAME     ;/
      212Fh  ..  RESERVED_SEQ_2F-33        Reserved
      2134h   1  UNDOC_SEQ_34              (0..FFh)
      2135h  ..  RESERVED_SEQ_35-44        Reserved
      2145h   2  UNDOC_SEQ_45              (0..FFFFh)
      2147h  ..  RESERVED_SEQ_47-59        Reserved

DSi Aptina Camera Variables: AE (Auto Exposure) (MCU:22xxh)

Auto Exposure Variables AE (MCU:2200h-2261h)

      2200h  ..  RESERVED_AE_00            Reserved
      2202h   1  AE_WINDOW_POS             AE Window Position Y0 and X0
                   0-3  X0 (in units of 1/16th of frame width)  (0..0Fh)
                   4-7  Y0 (in units of 1/16th of frame height) (0..0Fh)
      2203h   1  AE_WINDOW_SIZE            AE Window Height and Width (def=FFh)
                   0-3  Width  (units of 1/16th of frame width, minus 1)  (0..0Fh)
                   4-7  Height (units of 1/16th of frame height, minus 1) (0..0Fh)
      2204h  ..  RESERVED_AE_04            Reserved
      2206h   1  AE_TARGET                 AE Target Brightness (0..FFh, def=32h)
      2207h   1  AE_GATE                   AE Sensitivity       (0..FFh, def=04h)
      2208h  ..  UNDOC_AE_08               (0..FFh, def=02h)
      2209h  ..  RESERVED_AE_09-0A         Reserved
      220Bh   1  AE_MIN_INDEX              Min                      (0-FFh)
      220Ch   1  AE_MAX_INDEX              Max allowed zone number  (0-FFh,def=18h)
      220Dh   1  AE_MIN_VIRTGAIN           Min allowed virtual gain (0-FFh,def=10h)
      220Eh   1  AE_MAX_VIRTGAIN           Max allowed virtual gain (0-FFh,def=80h)
      220Fh  ..  RESERVED_AE_0F-11         Reserved
      2212h   2  AE_MAX_DGAIN_AE1          Max digital gain pre-LC  (def=8000h)
      2214h  ..  RESERVED_AE_14-16         Reserved
      2217h   1  AE_STATUS                 AE Status
                   0   AE_at_limit (1=AE reached limit)
                   1   R9_changed  (1=Need to skip frame)
                   2   Ready       (0=AE not ready, 1=AE ready)
                   3-7 Unused (0)
      2218h   1  AE_CURRENT_Y              Last measured luma   (0-FFh,def=4Bh) (R)
      2219h   2  AE_R12                    Curr shutter delay       (def=0279h) (R)
      221Bh   1  AE_INDEX                  Curr zone integration time (def=04h) (R)
      221Ch   1  AE_VIRTGAIN               Curr virtual gain    (0-FFh,def=10h) (R)
      221Dh  ..  RESERVED_AE_1D-1E         Reserved
      221Fh   2  AE_DGAIN_AE1              Current digital gain pre-LC (def=0080h)
      2221h  ..  RESERVED_AE_21            Reserved
      2222h   2  AE_R9                     Current R9:0 value (0-FFFFh, def=0010h)
      2224h  ..  RESERVED_AE_24-2C         Reserved
      222Dh   2  AE_R9_STEP                Integration time per zone   (def=009Dh)
      222Fh  ..  RESERVED_AE_2F-49         Reserved
      224Ah   1  AE_TARGETMIN              Min value for target  (0..FFh, def=32h)
      224Bh   1  AE_TARGETMAX              Max value for target  (0..FFh, def=96h)
      224Ch   1  AE_TARGETBUFFERSPEED      Target Buffer Speed   (0..FFh, def=0Ch)
      224Dh  ..  RESERVED_AE_4D            Reserved
      224Fh   1  AE_BASETARGET             Target Base           (0..FFh, def=36h)
      2250h  ..  RESERVED_AE_50-61         Reserved
      2262h  ..  RESERVED_AE_62-64         Reserved (REV3)

DSi Aptina Camera Variables: AWB (Auto White Balance) (MCU:23xxh)

Auto White Balance Variables AWB (MCU:2300h..236Eh)

      2300h  ..  RESERVED_AWB_00           Reserved
      2302h   1  AWB_WINDOW_POS            AWB Window Position Y0 and X0
                   0-3  X0 (in units of 1/16th of frame width)  (0..0Fh)
                   4-7  Y0 (in units of 1/16th of frame height) (0..0Fh)
      2303h   1  AWB_WINDOW_SIZE           AWB Window Size (def=EFh)
                   0-3  Width  (units of 1/16th of frame width, minus 1)  (0..0Fh)
                   4-7  Height (units of 1/16th of frame height, minus 1) (0..0Fh)
      2304h  ..  RESERVED_AWB_04           Reserved
      2306h 3x2  AWB_CCM_L_0-2             Left CCM K11,K12,K13 (0180h,FF00h,0080h)
      230Ch 3x2  AWB_CCM_L_3-5             Left CCM K21,K22,K23 (FF66h,0180h,FFEEh)
      2312h 3x2  AWB_CCM_L_6-8             Left CCM K31,K32,K33 (FFCDh,FECDh,019Ah)
      2318h   2  AWB_CCM_L_9               Left CCM Red/Green gain  (0020h)
      231Ah   2  AWB_CCM_L_10              Left CCM Blue/Green gain (0033h)
      231Ch 3x2  AWB_CCM_RL_0-2            DeltaCCM D11,D12,D13 (0100h,FF9Ah,xxxxh)
      2322h 3x2  AWB_CCM_RL_3-5            DeltaCCM D21,D22,D23 (004Dh,FFCDh,FFB8h)
      2328h 3x2  AWB_CCM_RL_6-8            DeltaCCM D31,D32,D33 (004Dh,0080h,FF66h)
      232Eh   2  AWB_CCM_RL_9              DeltaCCM Red/Green gain  (0008h)
      2330h   2  AWB_CCM_RL_10             DeltaCCM Blue/Green gain (FFF7h)
      2332h 3x2  AWB_CCM_0-2               Curr CCM C11,C12,C13 (01BAh,FF5Bh,FFF1h)
      2338h 3x2  AWB_CCM_3-5               Curr CCM C21,C22,C23 (FFC7h,01B9h,FF87h)
      233Eh 3x2  AWB_CCM_6-8               Curr CCM C31,C32,C33 (FFF9h,FF32h,01DCh)
      2344h   2  AWB_CCM_9                 Curr CCM Red/Green gain  (003Ch)
      2346h   2  AWB_CCM_10                Curr CCM Blue/Green gain (002Bh)
      2348h   1  AWB_GAIN_BUFFER_SPEED     Gain Speed (1-20h, def=08h, 20h=fastest)
      2349h   1  AWB_JUMP_DIVISOR          Jump Divisor (1-FFh, def=02h, 1=fastest)
      234Ah   1  AWB_GAIN_MIN              Min AWB Red     (def=59h) ;\Digital Gain
      234Bh   1  AWB_GAIN_MAX              Max allowed Red (def=B6h) ; Min/max
      234Ch   1  AWB_GAINMIN_B             Min AWB         (def=59h) ; (0..FFh)
      234Dh   1  AWB_GAINMAX_B             Max allowed     (def=A6h) ;/
      234Eh   1  AWB_GAIN_R                Current R digital gain    ;\Current Gain
      234Fh   1  AWB_GAIN_G                Current G digital gain    ; (0..FFh,
      2350h   1  AWB_GAIN_B                Current B digital gain    ;/def=80h)
      2351h   1  AWB_CCM_POSITION_MIN      Min/Left  (def=?)   ;\(range 0..FFh,
      2352h   1  AWB_CCM_POSITION_MAX      Max/Right (def=7Fh) ; 00h=incandescent,
      2353h   1  AWB_CCM_POSITION          Position  (def=40h) ;/7Fh=daylight)
      2354h   1  AWB_SATURATION            Saturation (0..FFh, def=80h, 80h=100%)
      2355h   1  AWB_MODE                  Misc control for AWB (0..FFh)
                   0  Steady         (1=AWB is done)
                   1  Limits Reached (1=AWB limit is reached)
                   2  Reserved
                   3  Reserved
                   4  Reserved
                   5  Force_unit_dgains
                   6  NormCCM_off
      2356h   2  AWB_GAINR_BUF             Time-buffered R gain (0..FFFFh)
      2358h   2  AWB_GAINB_BUF             Time-buffered B gain (0..FFFFh)
      235Ah  ..  RESERVED_AWB_5A-5C        Reserved
      235Dh   1  AWB_STEADY_BGAIN_OUT_MIN  (0-FF, def=78h)
      235Eh   1  AWB_STEADY_BGAIN_OUT_MAX  (0-FF, def=86h)
      235Fh   1  AWB_STEADY_BGAIN_IN_MIN   (0-FF, def=7Eh)
      2360h   1  AWB_STEADY_BGAIN_IN_MAX   (0-FF, def=82h)
      2361h   2  UNDOC_AWB_61              (0..FFFFh, def=0040h)
      2363h   1  AWB_TG_MIN0               True Gray minimum (0..FFh, def=D2h)
      2364h   1  AWB_TG_MAX0               True Gray maximum (0..FFh, def=F6h)
      2365h   1  AWB_X0                    (0-FFh, def=10h)
      2366h   1  AWB_KR_L                  (0-FFh, def=80h)
      2367h   1  AWB_KG_L                  (0-FFh, def=80h)
      2368h   1  AWB_KB_L                  (0-FFh, def=80h)
      2369h   1  AWB_KR_R                  (0-FFh, def=80h)
      236Ah   1  AWB_KG_R                  (0-FFh, def=80h)
      236Bh   1  AWB_KB_R                  (0-FFh, def=80h)
      236Ch  ..  RESERVED_AWB_6C-6E        Reserved

DSi Aptina Camera Variables: FD (Anti-Flicker) (MCU:24xxh)

Anti-Flicker Variables FD (MCU:2400h..247Bh)

      2400h  ..  RESERVED_FD_00            Reserved
      2402h   1  FD_WINDOW_POSH            Window Pos H (0..FFh, def=1Dh)
                   0-3  Width (in units of 1/16th of frame width, minus 1) (0..0Fh)
                   4-7  X0 (=position/origin or so?) (0..0Fh)
      2403h   1  FD_WINDOW_HEIGHT          FlickerMeasurementWindowHeight (def=04h)
                   0-5  Flicker measurement window height in rows (0..3Fh)
                   6-7  Unspecified
      2404h   1  FD_MODE                   Flicked Detection switches/indicators
                   0-3  Reserved      (0..0Fh) (R)
                   4    Debug_mode    (0=Disable, 1=Enable single period mode)
                   5    Curr Flicker State (0=60Hz, 1=50Hz) (R)
                   6    Curr Settings (0=60Hz, 1=50Hz)
                   7    Manual Mode   (0=Disable, 1=Enable)
      2405h  ..  RESERVED_FD_05-07         Reserved
      2408h   1  FD_SEARCH_F1_50           Search F1 50Hz  (0..FFh, def=33h)
      2409h   1  FD_SEARCH_F2_50           Search F2 50Hz  (0..FFh, def=35h)
      240Ah   1  FD_SEARCH_F1_60           Search F1 60Hz  (0..FFh, def=29h)
      240Bh   1  FD_SEARCH_F2_60           Search F2 60Hz  (0..FFh, def=2Bh)
      240Ch   1  UNDOC_FD_0C               (0..FFh)
      240Dh   1  FD_STAT_MIN               Stat Min (0..FFh, def=03h)
      240Eh   1  FD_STAT_MAX               Stat Max (0..FFh, def=05h)
      240Fh  ..  RESERVED_FD_0F            Reserved
      2410h   1  FD_MIN_AMPLITUDE          Ignore Signals below Min (0..FFh, def=5)
      2411h   2  FD_R9_STEP_F60_A          60HzA (def=0D4h) ;\Minimal Shutter Width
      2413h   2  FD_R9_STEP_F50_A          50HzA (def=103h) ; Steps for 60Hz/50H AC
      2415h   2  FD_R9_STEP_F60_B          60HzB (def=09Dh) ; in Context A/B
      2417h   2  FD_R9_STEP_F50_B          50HzB (def=0B8h) ;/(0..FFFFh)
      2419h  ..  RESERVED_FD_19-7B         Reserved

DSi Aptina Camera Variables: MODE (Mode/Context) (MCU:27xxh)

Mode Variables MODE (MCU:2700h..2768h)

      2700h  ..  RESERVED_MODE_00-02              Reserved
      2703h   2  MODE_OUTPUT_WIDTH_A        (CX)  (0..FFFFh, def=0320h)  ;\Size A
      2705h   2  MODE_OUTPUT_HEIGHT_A       (CY)  (0..FFFFh, def=0258h)  ;/
      2707h   2  MODE_OUTPUT_WIDTH_B              (0..FFFFh, def=0640h)  ;\Size B
      2709h   2  MODE_OUTPUT_HEIGHT_B             (0..FFFFh, def=04B0h)  ;/
      270Bh   1  MODE_A_MIPI_VC                   (0..07h) (REV3)        ;-Mipi A
      270Ch   1  MODE_B_MIPI_VC                   (0..07h) (REV3)        ;-Mipi B
      270Dh   2  MODE_SENSOR_ROW_START_A    (Y1)  (0..FFFFh)             ;\
      270Fh   2  MODE_SENSOR_COL_START_A    (X1)  (0..FFFFh)             ;
      2711h   2  MODE_SENSOR_ROW_END_A      (Y2)  (0..FFFFh, def=040Dh)  ;
      2713h   2  MODE_SENSOR_COL_END_A      (X2)  (0..FFFFh, def=050Dh)  ; Sensor
      2715h   2  MODE_SENSOR_ROW_SPEED_A          (0..0777h, def=0112h)  ; A
                   0-2:  pixclk_speed (0..7)                             ;
                           1ADC: Pclk = 2 mclks * bits[0:2]              ;
                           2ADC: bits[0:2]                               ;
                   4-6:  Reserved (0..7)                                 ;
                   8-10: Reserved (0..7)                                 ;
      2717h   2  MODE_SENSOR_READ_MODE_A          (0..FFFFh, def=046Ch)  ;
                   0:   horiz_mirror                                     ;
                   1:   vert_flip                                        ;
                   2-4: y_odd_inc (0..7)                                 ;
                   5-7: x_odd_inc (0..7)                                 ;
                   9:   low_power                                        ;
                   10:  xy_bin_en                                        ;
                   11:  x_bin_en                                         ;
      2719h   2  MODE_SENSOR_FINE_CORRECTION_A    (0..FFFFh, def=007Bh)  ;
      271Bh   2  MODE_SENSOR_FINE_IT_MIN_A        (0..FFFFh, def=0408h)  ;
      271Dh   2  MODE_SENSOR_FINE_IT_MAX_MARGIN_A (0..FFFFh, def=00ABh)  ;
      271Fh   2  MODE_SENSOR_FRAME_LENGTH_A       (0..FFFFh, def=0293h)  ;
      2721h   2  MODE_SENSOR_LINE_LENGTH_PCK_A    (0..FFFFh, def=07D0h)  ;/
      2723h   2  MODE_SENSOR_ROW_START_B          (0..FFFFh, def=0004h)  ;\
      2725h   2  MODE_SENSOR_COL_START_B          (0..FFFFh, def=0004h)  ; Sensor
      2727h   2  MODE_SENSOR_ROW_END_B            (0..FFFFh, def=040Bh)  ; B
      2729h   2  MODE_SENSOR_COL_END_B            (0..FFFFh, def=050Bh)  ;
      272Bh   2  MODE_SENSOR_ROW_SPEED_B          (0..0777h, def=0111h)  ; (same
      272Dh   2  MODE_SENSOR_READ_MODE_B          (0..FFFFh, def=0024h)  ; as
      272Fh   2  MODE_SENSOR_FINE_CORRECTION_B    (0..FFFFh, def=00A4h)  ; Sensor
      2731h   2  MODE_SENSOR_FINE_IT_MIN_B        (0..FFFFh, def=0408h)  ; A, see
      2733h   2  MODE_SENSOR_FINE_IT_MAX_MARGIN_B (0..FFFFh, def=00A4h)  ; there)
      2735h   2  MODE_SENSOR_FRAME_LENGTH_B       (0..FFFFh, def=04EDh)  ;
      2737h   2  MODE_SENSOR_LINE_LENGTH_PCK_B    (0..FFFFh, def=0D06h)  ;/
      2739h   2  MODE_CROP_X0_A                   (0..FFFFh)             ;\
      273Bh   2  MODE_CROP_X1_A                   (0..FFFFh, def=031Fh)  ; Crop A
      273Dh   2  MODE_CROP_Y0_A                   (0..FFFFh)             ;
      273Fh   2  MODE_CROP_Y1_A                   (0..FFFFh, def=0257h)  ;/
      2741h  ..  RESERVED_MODE_41-45              Reserved
      2747h   2  MODE_CROP_X0_B                   (0..FFFFh)             ;\
      2749h   2  MODE_CROP_X1_B                   (0..FFFFh, def=063Fh)  ; Crop B
      274Bh   2  MODE_CROP_Y0_B                   (0..FFFFh)             ;
      274Dh   2  MODE_CROP_Y1_B                   (0..FFFFh, def=04AFh)  ;/
      274Fh  ..  RESERVED_MODE_4F-53              Reserved
      2755h   2  MODE_OUTPUT_FORMAT_A             Format A (0..FFFFh     ;\
      2757h   2  MODE_OUTPUT_FORMAT_B             Format B (0..FFFFh     ;
                   0     swap_channels (swap Cb/Cr in YUV and R/B in RGB);
                   1     swap_chrominance_luma                           ; Format
                   2     bayer_out (Progressive Bayer)                   ; A/B
                   3     monochrome (0..1)                               ;
                   4     Reserved                                        ;
                   5     output_mode (0=YUV, 1=RGB)                      ;
                   6-7   RGB Format (0=565, 1=555, 2=444xh, 3:x444h)     ;
                   8     Processed Bayer (0..1)                          ;
                   9     Invert out_clk (0..1) (REV3)                    ;
                   10-15 Unspecified                                     ;/
      2759h   2  MODE_SPEC_EFFECTS_A              Effects A  (def=6440h) ;\
      275Bh   2  MODE_SPEC_EFFECTS_B              Effects B  (def=6440h) ;
                   0-2  Selection (1=Mono, 2=Sepia, 3=Negative,          ; Effects
                          4=Solarization, 5=Solarization w/ UV)          ; A/B
                   3-5  Dither_bitwidth                                  ;
                   6    Dither_luma                                      ;
                   8-15 Solarization Threshold (0..7 for diff effects)   ;/
      275Dh   1  MODE_Y_RGB_OFFSET_A              Offset A (00h..FFh)    ;\Offset
      275Eh   1  MODE_Y_RGB_OFFSET_B              Offset B (00h..FFh)    ;/A/B
      275Fh   2  MODE_COMMON_MODE_SETTINGS_BRIGHT_COLOR_KILL             ;\
                   Shadow register for 35A4h in SOC2                     ;
                   0-2   Color kill saturation point (0..7)              ; Kill
                   3-5   Bright color kill gain      (0..7)              ; Bright
                   6-8   Bright color kill threshold (0..7)              ;
                   9     Signal_ctrl (1=use luma as min/max value)       ;
                   10    en_kl       (1=enable bright color kill)        ;
                   11-15 Unspecified                                     ;/
      2761h   2  MODE_COMMON_MODE_SETTINGS_DARK_COLOR_KILL               ;\
                   Shadow register for 35A2h in SOC2                     ;
                   0-2   Dark color kill gain      (0..7)                ; Kill
                   3-5   Dark color kill threshold (0..7)                ; Dark
                   6     Signal_ctrl (1=use luma as min/max value)       ;
                   7     en_dark_kl  (1=enable dark color kill)          ;
                   8-15  Unspecified                                     ;/
      2763h   2  MODE_COMMON_MODE_SETTINGS_FX_SEPIA_SETTINGS             ;\
                   0-7   Sepia constants for Cr (00h..FFh)               ; Sepia
                   8-15  Sepia constants for Cb (00h..FFh)               ;/
      2765h   1  MODE_COMMON_MODE_SETTINGS_FILTER_MODE                   ;\
                   Shadow register for 326Eh in SOC1                     ;
                   0-2   UV Filter mode (0..7)                           ; Filter
                   3-4   Y Filter mode  (0..3)                           ;
                   5     Enable_y_filter (enable y permanently)          ;
                   6     Threshold_switch, switch for adaptive Y filter threshold
                   7     Off_switch, B/W filter enable switch            ;/
      2766h   1  MODE_COMMON_MODE_SETTINGS_TEST_MODE   Test (00h..FFh)
                   0-?  Test Pattern (0=None?, 1=Flat, 2=Ramp, 3=ColorBars,
                        4=VertStripes, 5=Noise, 6=HoriStripes)
                   Output test pattern (instead camera image)
                   requires "Refresh Command" sent to Sequencer
      2767h  ..  RESERVED_MODE_67-68                   Reserved

DSi Aptina Camera Variables: HG (Histogram) (MCU:2Bxxh)

Histogram Variables HG (MCU:2B00h..2B61h)

      2B00h  ..  RESERVED_HG_00-03         Reserved
      2B04h   1  HG_MAX_DLEVEL             DarkLevel Limit (0..FFh, def=40h)
      2B05h  ..  RESERVED_HG_05            Reserved
      2B06h   1  HG_PERCENT                Percent?        (0..FFh, def=03h)
      2B07h  ..  RESERVED_HG_07            Reserved
      2B08h   1  HG_DLEVEL                 DarkLevel       (0..FFh, def=10h)
      2B09h  ..  RESERVED_HG_09-16         Reserved
      2B17h   1  HG_AVERAGELUMA            Average Luma      (0..FFh)
      2B18h  ..  RESERVED_HG_18-1A         Reserved
      2B1Bh   2  HG_BRIGHTNESSMETRIC       Brightness Metric (0..FFFFh)
      2B1Dh  ..  RESERVED_HG_1D            Reserved
      2B1Fh   1  HG_LLMODE                 Low Light mode controls (def=C4h)
                   0-3  Brightness Metric Prescaler (01h..0Fh)
                   4-5  Unused (0)
                   6    HG_2d_corr_vs_clusterdc
                   7    Clusterdc_vs_gains
      2B20h   1  HG_LL_SAT1                LL_SAT1            (0..FFh, def=43h)
      2B21h   1  UNDOC_HG_21               Whatever           (0..FFh, def=10h)
      2B22h   1  HG_LL_APCORR1             LL_APCORR1         (0..FFh, def=03h)
      2B23h   1  UNDOC_HG_23               Whatever           (0..FFh, def=04h)
      2B24h   1  HG_LL_SAT2                LL_SAT2            (0..FFh, def=0Ch)
      2B25h   1  HG_LL_INTERPTHRESH2       LL_INTERPTHRESH2   (0..FFh, def=23h)
      2B26h   1  HG_LL_APCORR2             LL_APCORR2         (0..FFh)
      2B27h   1  HG_LL_APTHRESH2           LL_APTHRESH2       (0..FFh, def=04h)
      2B28h   2  HG_LL_BRIGHTNESSSTART     LL_BRIGHTNESSSTART (0..FFFFh, def=0A8Ch)
      2B2Ah   2  HG_LL_BRIGHTNESSSTOP      LL_BRIGHTNESSSTOP  (0..FFFFh, def=34BCh)
      2B2Ch   1  HG_NR_START_R             NR_START_R         (0..FFh, def=06h)
      2B2Dh   1  HG_NR_START_G             NR_START_G         (0..FFh, def=0Eh)
      2B2Eh   1  HG_NR_START_B             NR_START_B         (0..FFh, def=06h)
      2B2Fh   1  HG_NR_START_OL            NR_START_OL        (0..FFh, def=06h)
      2B30h   1  HG_NR_STOP_R              NR_STOP_R          (0..FFh, def=1Eh)
      2B31h   1  HG_NR_STOP_G              NR_STOP_G          (0..FFh, def=1Eh)
      2B32h   1  HG_NR_STOP_B              NR_STOP_B          (0..FFh, def=1Eh)
      2B33h   1  HG_NR_STOP_OL             NR_STOP_OL         (0..FFh, def=1Eh)
      2B34h   1  HG_NR_GAINSTART           NR_GAINSTART       (0..FFh, def=08h)
      2B35h   1  HG_NR_GAINSTOP            NR_GAINSTOP        (0..FFh, def=80h)
      2B36h   1  HG_CLUSTERDC_TH           CLUSTERDC_TH       (0..FFh, def=1Eh)
      2B37h   1  HG_GAMMA_MORPH_CTRL       Gamma Morphing Control (0..FFh, def=3)
                   0-1 Enable Gamma Morph (0=Disable, 1=Use Table A, 2=Use Table B,
                       3=AutoMorph between Table A and B based on BrightnessMetric)
                   2-7 Unspecified
      2B38h   2  HG_GAMMASTARTMORPH        Gamma Start Morph (0..FFFFh, def=0A8Ch)
      2B3Ah   2  HG_GAMMASTOPMORPH         Gamma Stop Morph  (0..FFFFh, def=34BCh)
      2B3Ch  19  HG_GAMMA_TABLE_A_0-18     Gamma Table A for normal light condition
                  Default=xx,1B,2E,4C,78,98,B0,E8,CF,D9,E1,E8,EE,F2,F6,F9,FB,FD,FF
      2B4Fh  19  HG_GAMMA_TABLE_B_0-18     Gamma Table B for low light condition
                  Default=xx,0F,1A,2E,50,6A,80,91,A1,AF,BB,C6,D0,D9,E2,EA,F1,F9,FF
                  Above 2 tables have normal byte-order (Entry0,Entry1,...,Entry18)
      2B62h   2  HG_FTB_START_BM           (0..FFFFh, def=7FBCh) (REV3)
      2B64h   2  HG_FTB_STOP_BM            (0..FFFFh, def=82DCh) (REV3)
      2B66h   2  HG_CLUSTER_DC_BM          (0..FFFFh, def=4A38h) (REV3)

DSi Alternate Cameras from Unknown Manufacturer

Device A0h/E0h appear to be cameras from an alternate manufacturer. DSi games are supporting these devices, but as by now, there aren't any DSi consoles known to be actually fitted with these cameras.
The camera type & manufacturer are still unknown. Below initialization data is containing some characterstic info that should allow to identify them. For example, register 03h appears to be bank-switching the other registers.
unknown_cam_get_chip_id:
Reading an 8bit value from index 00h (in any bank?) seems to return some Chip ID, at least the DSi is reading that register before initialization (despite of reading it, the DSi does appear to ignore that value though).
Note: On a DSi with Aptina cameras, trying to read anything from IC2 devices A0h/E0h does just return FFh-bytes.
Formatting Note
Below tables consist of "Index,Length,Data[Length]" entries.
unknown_cam_type_code_list_init:

      003h, 1,001h               ;<-- bank maybe?
      009h, 3,0E2h,002h,002h
      004h, 1,010h
      004h, 1,0A0h
      004h, 2,090h,04Ch
      00Dh, 1,0FFh
      016h, 1,053h
      018h, 3,002h,001h,00Fh
      020h, 1,000h
      023h, 2,000h,000h
      034h, 8,000h,003h,000h,003h,001h,002h,000h,0C2h
      03Dh, 4,050h,050h,000h,067h
      042h, 1,01Ch
      04Ah, 2,043h,0F8h
      04Eh, 7,028h,0FCh,000h,024h,014h,008h,008h
      056h,13,000h,018h,028h,034h,044h,056h,06Eh,080h,0A4h,0C2h,0D6h,0E8h,0F4h
      065h,12,00Fh,038h,008h,000h,01Fh,01Fh,01Fh,01Fh,01Fh,01Fh,01Fh,01Fh
      07Ah,17,039h,03Bh,03Ah,036h,03Ch,03Ch,03Ah,03Ch,03Ch,03Ch,03Ah,03Ch,038h
              03Ah,031h,03Ah,082h
      08Dh,22,08Ah,090h,096h,09Ch,0A4h,0AAh,0B0h,0B6h,0BCh,0C4h,0CAh,0D0h,0D6h
              0DCh,0E4h,0EAh,0F0h,0F2h,0F4h,0F6h,0F8h,0FAh
      0A9h, 1,02Bh
      0ABh, 3,02Eh,000h,050h
      0AFh, 1,070h
      0B2h, 4,03Ch,068h,049h,070h
      0B7h,21,032h,000h,00Eh,0F8h,00Ch,07Ah,040h,000h,000h,010h,044h,064h,052h
              012h,001h,0D7h,004h,002h,024h,002h,024h
      0D4h, 5,004h,004h,008h,00Ah,010h
      016h, 1,0F7h
      0DEh, 2,002h,024h
      016h, 1,053h
      0E1h, 1,034h
      0FFh, 1,00Fh
      003h, 1,002h               ;<-- bank maybe?
      005h, 2,06Dh,004h
      011h, 4,004h,048h,004h,048h
      016h, 2,00Ch,0D8h
      019h, 2,00Ch,0D8h
      01Eh, 6,002h,024h,070h,000h,001h,06Eh
      026h, 7,008h,00Fh,00Fh,006h,0FFh,0FFh,003h
      02Eh,19,07Eh,088h,074h,07Eh,008h,010h,080h,008h,084h,078h,001h,003h,00Ah
              025h,060h,0B0h,006h,000h,000h
      042h, 7,080h,010h,010h,010h,040h,080h,0FFh
      04Ah,30,000h,000h,001h,0E5h,001h,0E0h,000h,070h,002h,0F0h,000h,02Eh,001h
              0F3h,000h,005h,000h,000h,001h,000h,000h,0C0h,000h,026h,000h,01Ch
              000h,0B3h,000h,086h
      069h,36,000h,000h,006h,014h,014h,01Fh,000h,000h,000h,000h,000h,01Fh,000h
              000h,010h,010h,010h,01Fh,000h,000h,004h,004h,004h,01Fh,000h,000h
              000h,000h,000h,01Fh,000h,000h,010h,010h,010h,01Fh
      095h, 1,084h
      097h,18,002h,000h,0FFh,0FFh,000h,0FFh,0FFh,000h,000h,0FFh,0FFh,000h,0FFh
              0FFh,000h,0F8h,014h,010h
      0AAh,13,044h,098h,08Ch,09Ch,048h,08Ch,08Ah,09Ch,046h,02Ah,080h,008h,026h
      0B8h, 8,02Ah,084h,000h,026h,02Ah,080h,008h,020h
      0C1h,10,038h,020h,01Fh,01Dh,034h,020h,01Fh,01Dh,045h,05Dh
      0CCh, 2,020h,020h
      0D0h, 3,080h,000h,0FFh
      003h, 1,000h               ;<-- bank maybe?
      013h, 2,000h,04Ch
      01Dh, 2,000h,04Ch
      015h, 2,001h,05Fh
      055h, 2,001h,05Eh
      031h, 6,006h,068h,00Ch,005h,004h,047h
      047h, 2,000h,003h
      04Ah, 3,0A0h,000h,003h
      04Fh, 2,000h,003h
      059h, 2,000h,001h
      05Fh, 2,000h,001h
      066h, 1,09Eh
      06Eh, 2,07Fh,003h
      075h, 1,050h
      07Ah, 2,000h,001h
      07Eh, 1,020h
      082h, 1,038h
      084h,14,003h,040h,003h,040h,000h,000h,040h,003h,0FFh,002h,008h,020h,018h,006h
      093h,11,020h,040h,040h,01Fh,002h,000h,000h,000h,000h,000h,000h
      003h, 1,001h               ;<-- bank maybe?
      00Fh, 1,0C9h                    ;or, for Device E0h: 00Fh, 1,0C8h
      052h, 3,004h,008h,008h          ;or, for Device E0h: N/A
      003h, 1,002h               ;<-- bank maybe?
      026h, 1,008h                    ;or, for Device E0h: 026h, 1,000h
      0CCh, 2,0C0h,0C0h               ;or, for Device E0h: N/A
      0B4h, 1,000h                    ;or, for Device E0h: N/A
      0B6h, 1,026h                    ;or, for Device E0h: N/A
      0B9h, 3,000h,008h,026h          ;or, for Device E0h: N/A
      0BDh, 1,000h                    ;or, for Device E0h: N/A
      026h, 1,008h                    ;or, for Device E0h: N/A
      003h, 1,001h               ;<-- bank maybe?
      02Dh, 1,0FFh
      004h, 1,020h

unknown_cam_type_code_list_activate:

      003h, 1,002h               ;<-- bank maybe?
      0A7h, 1,014h
      003h, 1,001h               ;<-- bank maybe?
      004h, 1,0A0h
      004h, 1,090h
      02Dh, 1,000h
      004h, 1,098h

Random Note
This info is probably not really helpful, but the DSi firmware contains code for setting Register C1h..C9h (within unknown bank) to one of the following twelve settings.

      C1h, 8,038h,030h,01Fh,01Fh,02Ch,030h,01Fh,01Fh
      C1h, 8,038h,030h,01Fh,01Fh,038h,030h,01Fh,01Fh
      C1h, 8,02Ch,030h,01Fh,01Fh,02Ch,030h,01Fh,01Fh
      C1h, 8,02Ch,030h,01Fh,01Fh,02Ch,030h,01Fh,01Fh
      C1h, 8,02Ch,030h,01Fh,01Fh,02Ch,030h,01Fh,01Fh
      C1h, 8,02Ch,030h,01Fh,01Fh,02Ch,030h,01Fh,01Fh
      C1h, 8,030h,028h,018h,018h,034h,028h,008h,018h
      C1h, 8,030h,028h,018h,018h,030h,028h,008h,018h
      C1h, 8,028h,028h,018h,018h,028h,028h,008h,018h
      C1h, 8,028h,028h,018h,018h,028h,028h,008h,018h
      C1h, 8,028h,028h,018h,018h,028h,028h,008h,018h
      C1h, 8,028h,028h,018h,018h,028h,028h,008h,018h

DSi Cameras

Camera registers
Cameras are controlled and initialized via I2C bus (on ARM7 side).
DSi I2C Bus
The actual camera data transfers are done with below registers (on ARM9 side).
4004200h - DSi9 - CAM_MCNT - Camera Module Control

      0     Unknown                                                      (R or R/W)
      1     Unknown (1=Enable?)                                          (R or R/W)
      2-4   Unknown                                                      (R or R/W)
      5     Unknown (1=Enable?) (0=CamI2C fails?)                        (R or R/W)
      6     Unknown                                                      (R or R/W)
      7     Unknown (gets set automatically?)                                  (R?)
      8-15  Unknown/Unused (00h)                                               (0?)

Written values are 0000h and 0022h.
Camera I2C access works only when bit5=1 (otherwise camera i2c reads just return FFh; maybe bit5=0 issues a reset to the camera devices or so?)
"Used for resetting cameras. Once cameras are reset by poking this register, all three 0x0400420X camera registers are set to zero." Uh, is that really true, and which "three" registers are that?
4004202h - DSi9 - CAM_CNT - Camera Control

      0-3   Number of DMA scanlines minus 1 (usually 3=Four Scanlines)   (R or R/W)
      4     Data request? or Data overrun? or so?                               (R)
      5     Clear bit4, and flush CAM_DAT till next Camera Vblank?              (W)
      6-7   Unknown/Unused (0)                                                 (0?)
      8-9    ? Set to 2 during init, 0 on cameras shutdown                    (R/W)
      10     ? Set to 1 during init, 0 on cameras shutdown                    (R/W)
      11    IRQ Enable      (0=Disable, 1=Enable)                             (R/W)
      12    Unknown/Unused (0)                                                 (0?)
      13    Color Format    (0=Direct/YUV422, 1=Convert YUV-to-RGB555)   (R or R/W)
      14    Trimming Enable (0=Normal/FullPicture, 1=Crop via SOFS/EOFS) (R or R/W)
      15    Transfer Enable (0=Disable/AllowConfig, 1=Enable/Transfer)        (R/W)

4004204h - DSi9 - CAM_DAT - Camera Data (R)
Transfers two camera pixels at once (from left-to-right, starting with upper scanline).
Pixel Format (in "YUV422" mode):

      0-7   First Pixel Luminance (Y)   (unsigned, 00h..FFh, FFh=white)
      8-15  Both Pixels Blue (Cb aka U) (unsigned, 00h..FFh, 80h=gray)
      16-23 Second Pixel Luminance (Y)  (unsigned, 00h..FFh, FFh=white)
      24-31 Both Pixels Red (Cr aka V)  (unsigned, 00h..FFh, 80h=gray)

Pixel Format (in YUV-to-RGB555 mode) (matches 2D Engine Bitmap format):

      0-4   First Pixel Red Intensity    (0..31)
      5-9   First Pixel Green Intensity  (0..31)
      10-14 First Pixel Blue Intensity   (0..31)
      15    First Pixel Alpha (always 1=NonTransparent)
      16-20 Second Pixel Red Intensity   (0..31)
      21-25 Second Pixel Green Intensity (0..31)
      26-30 Second Pixel Blue Intensity  (0..31)
      31    Second Pixel Alpha (always 1=NonTransparent)

The Aptina camera's MODE_OUTPUT_FORMAT registers and MIPI_CONTROL register can be configured to output stuff like YUV, RGB555, RGB444, BGR565, RAW8, etc. However, DSi games seem to be always using YUV mode at camera side (and the above RGB555 data is produced by activating YUV-to-RGB conversion in CAM_CNT.bit13 at console side).
YUV mode gives better quality with 8bit resolution (whilst RGB555 mode is having only 5bit, and, as it's converted from YUV, it's certainly having color information being shared for each two-pixel groups, too).
CAM_DAT should be usually read via NDMA (see below). Manually reading CAM_DAT for one block (eg. 256x4 pixels) does work, but it's unknown how to retrieve further blocks via manual reading (except, one further block arrives after around 40000h clock cycles, but that's much too slow, and it's only one extra block).
Formulas for converting YUV to RGB

      R = Y+(Cr-80h)*1.402
      G = Y-(Cr-80h)*0.714)-(Cb-80h)*0.344
      B = Y+(Cb-80h)*1.772

Clip results to MinMax(00h,FFh), and apply final divide by 8 for RGB555.
4004210h - DSi9 - CAM_SOFS Camera Trimming Starting Position Setting (32bit)
4004214h - DSi9 - CAM_EOFS Camera Trimming Ending Position Setting (32bit)

      0      Unused (0)                                                         (0)
      1-9    X-Offset  (0..1FFh)   in words (ie. 2-pixel units)?         (R or R/W)
      10-15  Unused (0)                                                         (0)
      16-24  Y-Offset  (0..1FFh)   in scanlines?                         (R or R/W)
      25-31  Unused (0)                                                         (0)

Crops the incoming camera picture before passing it to CAM_DAT, used only if enabled in CAM_CNT.14.
Write-Protected Camera Bits (R or R/W)
The "(R or R/W)" bits are getting Read-Only when camera transmission is enabled, ie. they can be changed only when CAM_CNT.Bit15=0.
Internal Camera Reflections from LCD Backlights
The LCD backlights can cause nasty reflections on the internal camera (particulary when wearing glasses). There isn't much that could be done during preview, but when taking photos, it might be recommended to output a black/dark picture on the LCDs during the capture.
Internal Camera Mirroring
The Internal Camera is conventionally having x-flip enabled (in Aptina MODE_SENSOR_READ_MODE registers), so the internal camera will behave as a mirror (which may appear more familar to most users in preview mode). The firmware's "Nintendo DSi Camera" utility is even saving jpg's in mirrored form instead of saving true authentic photos.
Camera Detection
There are four possible I2C camera devices, although usually only two of them should be installed. The firmware detects the cameras by reading their Chip ID registers (but without actually insisting on any specific ID values, instead, it's merely checking the ACK error flag in the I2C register - if all four devices are returning ACK=okay, then it's actually initializing all four cameras; though unknown if the GUI is actually supporting that many cameras).
Camera Init

      [4004004h]=[4004004h] OR 0004h             ;SCFG_CLK, CamInterfaceClock = ON
      [4004200h]=0000h, delay(1Eh)               ;CAM_MCNT, Camera Module Control
      [4004004h]=[4004004h] OR 0100h, delay(1Eh) ;SCFG_CLK, CamExternal Clock = ON
      [4004200h]=0022h, delay(2008h)             ;CAM_MCNT, Camera Module Control
      [4004004h]=[4004004h] AND NOT 0100h        ;SCFG_CLK, CamExternal Clock = OFF
      [4004202h]=[4004202h] AND NOT 8000h        ;CAM_CNT, allow changing params
      [4004202h]=[4004202h] OR 0020h             ;CAM_CNT, flush data fifo
      [4004202h]=([4004202h] AND NOT 0300h) OR 0200h
      [4004202h]=[4004202h] OR 0400h
      [4004202h]=[4004202h] OR 0800h             ;CAM_CNT, irq enable
      [4004004h]=[4004004h] OR 0100h, delay(14h) ;SCFG_CLK, CamExternal Clock = ON
      issue "aptina_code_list_init" via I2C bus on ARM7 side
      [4004004h]=[4004004h] AND NOT 0100h        ;SCFG_CLK, CamExternal Clock = OFF
      [4004004h]=[4004004h] OR 0100h, delay(14h) ;SCFG_CLK, CamExternal Clock = ON
      issue "aptina_code_list_activate" via I2C bus on ARM7 side
      [4004202h]=[4004202h] OR 2000h             ;CAM_CNT, enable YUV-to-RGB555
      [4004202h]=([4004202h] AND NOT 000Fh) OR 0003h
      [4004202h]=[4004202h] OR 0020h             ;CAM_CNT, flush data fifo
      [4004202h]=[4004202h] OR 8000h             ;CAM_CNT, start transfer
      [4004120h]=04004204h                       ;NDMA1SAD, source CAM_DTA
      [4004124h]=0xxxxxxxh                       ;NDMA1DAD, dest RAM/VRAM
      [4004128h]=00006000h                       ;NDMA1TCNT, len for 256x192 total
      [400412Ch]=00000200h                       ;NDMA1WCNT, len for 256x4 blocks
      [4004130h]=00000002h                       ;NDMA1BCNT, timing interval or so
      [4004138h]=8B044000h                       ;NDMA1CNT, start camera DMA

Specifications
The Nintendo DSi contains two cameras. The cameras can be used in the Nintendo DSi Camera application or DSi games that are compatible.

      640*480 VGA (0.3 Megapixel)
      No zoom and no flash.

Photos saved in JPG format (saved in DCIM/ folder on the SD/SDHC or in the internal memory).
Camera Applications

      Nintendo DSi Camera
      System Menu (can take photos, and can display JPG's with "Star" sticker)
      Flipnote (doesn't directly support camera hardware, but can import JPG's)

Camera Games

      Asphalt 4 : Elite Racing (DSiWare)
      Brain Challenge (DSiWare)
      Classic Word Games
      Cooking Coach
      Pop SuperStar : Road To Celebrity (DSiWare)
      Real Football 2009 (DSiWare)
      WarioWare : Snapped! (DSiWare)
      iCarly
      Pokemon Black,White (2010,JP)
      Castle of Magic (DSiWare)
      Photo Dojo (DSiWare)
      System Flaw (mis-uses camera as gyro sensor)

DSi SD/MMC Protocol and I/O Ports

I/O Ports
DSi SD/MMC I/O Ports: Command/Param/Response/Data
DSi SD/MMC I/O Ports: Interrupt/Status
DSi SD/MMC I/O Ports: Control Registers
DSi SD/MMC I/O Ports: Unknown/Unused Registers
DSi SD/MMC I/O Ports: Misc
SD/MMC Protocol
DSi SD/MMC Protocol: Command/Response/Register Summary
DSi SD/MMC Protocol: General Commands
DSi SD/MMC Protocol: Block Read/Write Commands
DSi SD/MMC Protocol: Special Extra Commands
DSi SD/MMC Protocol: CSR Register (32bit Card Status Register)
DSi SD/MMC Protocol: SSR Register (512bit SD Status Register)
DSi SD/MMC Protocol: OCR Register (32bit Operation Conditions Register)
DSi SD/MMC Protocol: CID Register (128bit Card Identification)
DSi SD/MMC Protocol: CSD Register (128bit Card-Specific Data)
DSi SD/MMC Protocol: EXT_CSD Register (4096bit Extended CSD Register) (MMC)
DSi SD/MMC Protocol: RCA Register (16bit Relative Card Address)
DSi SD/MMC Protocol: DSR Register (16bit Driver Stage Register) (Optional)
DSi SD/MMC Protocol: SCR Register (64bit SD Card Configuration Register)
DSi SD/MMC Protocol: PWD Register (128bit Password plus 8bit Password len)
DSi SD/MMC Protocol: State
DSi SD/MMC Protocol: Signals
SDIO Protocol
DSi SDIO Special SDIO Commands
DSi SDIO Memory and I/O Maps
DSi SDIO Common Control Registers (CCCR)
DSi SDIO Function Basic Registers (FBR)
DSi SDIO Card Information Structures (CIS)
The DSi is using SDIO for the new DSi Wifi interface,
DSi Atheros Wifi SDIO Interface
DSi Atheros Wifi Internal Hardware
Pinouts
AUX DSi SD/MMC Pin-Outs

DSi SD/MMC I/O Ports: Command/Param/Response/Data

4004800h/4004A00h - SD_CMD - Command and Response/Data Type (R/W)

      15    undoc   Unknown/undoc  (read/write-able)
      14    undoc   Security Cmd?  (0=Normal, 1=Whatever/Security?) (sdio?)
      13    undoc   Data Length    (0=Single Block, 1=Multiple Blocks)
      12    undoc   Data Direction (0=Write, 1=Read)
      11    NTDT    Data Transfer  (0=No data, 1=With data)
      10-8  REP2-0  Response Type  (0=Auto, 1..2=Unknown/Reserved, 3=None, 4=48bit,
                                    5=48bit+Busy, 6=136bit, 7=48bitOcrWithoutCRC7)
      7-6   CMD1-0  Command Type   (0=CMD, 1=ACMD, 2..3=unknown, maybe GEN WR/RD?)
      5-0   CIX     Command Index  (0..3Fh, command index)

Setting Command Type to "ACMD" is (NOT!!!) automatically sending an APP_CMD prefix prior to the command number (but: unknown what RCA value it's sending in the APP_CMD's parameter field).
For Multiple Blocks, the hardware supports automatically sending STOP_TRANSMISSION after the last block.
DSi software is usually setting Response Type to "Auto", which is causing the hardware to use the correct response/data type for standard SD/MMC commands (bit11-13 are ignored/should be zero when using "Auto"; and maybe same for bit14-15?).
One exception is that the DSi firmware isn't using "Auto" for SDIO commands (maybe the hardware isn't aware of them; or it's unable to distinguish between read/write direction of CMD53, which would require examining the command's PARAM bits).
There are some differences between some SD and MMC commands, unknown if/how "Auto" is working in that cases; unknown if there's a SD-or-MMC mode select bit for that purpose in some configuration register (note: The DSi firmware uses manual config instead of Auto for CMD8, which differs for SD vs MMC).
Invalid values can cause ILA error (particulary on setting NTDT for CMD12, or for CMD's Response=None). ILA error will also occur if an old CMD is still busy.
4004804h/4004A04h - SD_CMD_PARAM0-1 - Argument (32bit, 2 halfwords) (R/W)

      31-0  Parameter value for CMD

The parameter value should be written <before> sending the command via SD_CMD/SDIO_CMD.
400480Ch/4004A0Ch - SD_RESPONSE0-7 - Response (128bit, 8 halfwords) (R)
After sending a command, wait for the CMDRESPEND bit (IRQ_STATUS.bit0) to get set, then read the RESPONSE (if the command does have any response).
For normal 32bit responses:

      31-0      Response
      127-32    Older Responses

For CID/CSD responses:

      119-0     120bit Response
      127-120   Zero (always?)

The above stuff is left-shifted when receiving new response bits (hence moving older responses to MSBs).
DATA16 vs DATA32
Data can be transferred in 16bit or 32bit units (as selected in DATA_CTL.bit1 and DATA32_IRQ.bit1). There are separate data, block len, and block count registers for 16bit and 32bit mode. 16bit mode uses two FIFOs (each with 200h-byte capactity). 32bit adds another FIFO (also with 200h-byte capacity):

                      .----------.                                  CPU
                   o--| FIFO16_A |--o             o---------------- 4004830h
      serial          '----------'   \                              16bit
      SD/MMC  ---o                    o---------o
      bus         \   .----------.               \    .--------.    CPU/NDMA
                   o--| FIFO16_B |--o             o---| FIFO32 |--- 400490Ch
                      '----------'                    '--------'    32bit

The 32bit mode is some odd patchwork, apparently Nintendo/Toshiba considered it easier to add an extra 32bit FIFO (rather than to figure out how to add native 32bit access to Toshiba's original 16bit chip design).
The DSi firmware does use both 32bit and 16bit mode once and then; 32bit mode can be faster, and it's required for NDMA transfers (which don't support 16bit).
40048D8h/4004AD8h - SD_DATA_CTL

      15-13  Always zero
      12     Unknown (usually 1)                                             (R?)
      11-6   Always zero
      5      Unknown (read/write-able) (usually 0)                           (R/W)
      4      Unknown (usually 1)                                             (R?)
      3-2    Always zero
      1      Select 16bit/32bit Data Mode (0=DATA16, 1=DATA32, see 4004900h) (R/W)
      0      Always zero

DATA32 mode requires setting both 40048D8h.bit1 and 4004900h.bit1. For DATA16 mode, both bits should be zero (though DATA16 seems to be also working the same way when only either of the bits is zero).
400480Ah/4004A0Ah - SD_DATA16_BLK_COUNT - NumBlocks for 16/32 bit Modes (R/W)
4004908h/4004B08h - SD_DATA32_BLK_COUNT - NumBlocks for 32 bit Mode (R/W)

      15-0   Number of Data Blocks for multiple read/write commands (0..FFFFh)

SD_DATA16_BLK_COUNT needs to be initialized in both 16bit and 32bit mode, the written value is copied to a internal register, which gets decremented after each block, and (when enabled in STOP_INTERNAL_ACTION.bit8) the hardware will automatically send STOP_TRANSMISSION (CMD12) after the last block (otherwise the hardware would keep transferring blocks infinitely).
For Data32 mode, DATA32_BLK_COUNT should be set to the same value (it doesn't really affect the transfer though, the register is intended only for watching the transfer progress: DATA32_BLK_COUNT is decremented after each block (when FIFO32 gets empty); except when it would become zero, in that case it stays stuck at 0001h).
4004826h/4004A26h - SD_DATA16_BLK_LEN - FIFO16 Size for 16/32 bit Modes (R/W)
4004904h/4004B04h - SD_DATA32_BLK_LEN - FIFO32 Size for 32 bit Mode (R/W)

      15-10  Always zero
      9-0    Data Block Length in bytes (for DATA16: clipped to max 0200h by hw)

SD_DATA16_BLK_LEN needs to be initialized in both 16bit and 32bit mode. For 32bit mode, SD_DATA32_BLK_LEN should be also set to the same value (otherwise odd effects might occur when forwarding FIFO16 to/from FIFO32).
The block length should be usually 0200h (for 512-byte SD/MMC memory blocks). Other values may be needed for SDIO functions, or when accessing SSR/SCR/PWD registers via data transfers.
DATA32_BLK_LEN can be set to max=3FFh (unlike DATA16_BLK_LEN which is clipped to max=200h by hardware), though settings bigger than 200h won't work in practice (since the FIFOs are only 200h bytes in size).
4004830h/4004A30h - SD_DATA16_FIFO - Data FIFO for 16bit Mode (R/W)
400490Ch/4004B0Ch - SD_DATA32_FIFO - Data FIFO for 32bit Mode (R/W)
For Data16:

      15-0   Data (Read/Write one block (usually 100h halfwords) upon RXRDY/TXRQ)

For Data32:

      31-0   Data (Read/Write one block (usually 80h words) upon RX32RDY/TX32RQ)

See the RXRDY/TXRQ and RX32RDY/TX32RQ interrupt flags for details.
The first Data32 block may be written even before sending the command (the DSi firmware is actually doing that, although, performance-wise, it would make sense only when writing multiple clusters, ie. sending the first block of the next cluster while the previous write is still in progress).
Observe that RX32RDY/TX32RQ are actually FIFO full/empty flags (getting triggered any time when FIFO is full/empty, so you must know for yourself if you want to transfer data in that situations; eg. FIFO empty will trigger even after having written all data blocks, or when not intending to write any data at all).

DSi SD/MMC I/O Ports: Interrupt/Status

All SD/MMC IRQs are triggering IF2.8, CardIRQ does ADDITIONALLY trigger IF2.9
All SDIO IRQs are triggering IF2.10, CardIRQ does ADDITIONALLY trigger IF2.11?
400481Ch/4004A1Ch - SD_IRQ_STATUS0-1 - Interrupt Status (R/ack)
4004820h/4004A20h - SD_IRQ_MASK0-1 - Interrupt Mask (R/W)
The IRQ_STATUS registers contain acknowledge-able IRQ Flags (those bits that that are maskable in IRQ_MASK register), as well as static read-only status bits without IRQ function (eg. WRPROTECT).
IRQ Flags/Write (0=Acknowledge, 1=No change)
IRQ Flags/Read (0=No IRQ, 1=IRQ)
IRQ Mask (0=Enable, 1=Disable) (8B7F031Dh when all IRQs disabled)

      Bit Stat  Mask  Function
      0   SREP  MREP  CMDRESPEND    (response end) (or R1b: busy end)
      1   0     0     Unknown/unused (always 0)
      2   SRWA  MRWA  DATAEND       (set after (last) data block end)
      3   SCOT  MCOT  CARD_REMOVE (0=No event, 1=Is/was newly ejected)      ;\
      4   SCIN  MCIN  CARD_INSERT (0=No event, 1=Is/was newly inserted)     ; SD
      5   undoc 0     SIGSTATE    (0=Ejected, 1=Inserted) (SDIO: always 1)  ; Slot
      6   0     0     Unknown/unused (always 0)                             ; Sw's
      7   undoc 0     WRPROTECT   (0=Locked/Ejected, 1=Unlocked/HalfEjected);/
      8   undoc undoc CARD_REMOVE_A (0=No event, 1=High-to-Low occurred)    ;\SD
      9   undoc undoc CARD_INSERT_A (0=No event, 1=Low-to-High occurred)    ; Slot
      10  undoc 0     SIGSTATE_A    (usually 1=High) ;also as so for SDIO   ;/Data3
      11  0     0     Unknown/unused (always 0)
      12  0     0     Unknown/unused (always 0)
      13  0     0     Unknown/unused (always 0)
      14  0     0     Unknown/unused (always 0)
      15  0     0     Unknown/unused (always 0)
      16  SCIX  MCIX  CMD_IDX_ERR   Bad CMD-index in response      (RCMDE,SCMDE)
      17  SCRC  MCRC  CRCFAIL       CRC response error (WCRCE,RCRCE,SCRCE,CCRCE)
      18  SEND  MEND  STOPBIT_ERR   End bit error      (WEBER,REBER,SEBER,CEBER)
      19  SDTO  MDTO  DATATIMEOUT   Data Timeout                (NRCS,NWCS,KBSY)
      20  SFOF  MFOF  RXOVERFLOW    HOST tried write full
      21  SFUF  MFUF  TXUNDERRUN    HOST tried read empty
      22  SCTO  MCTO  CMDTIMEOUT    Response start-bit timeout         (NRS,NSR)
      23  ???   0     Unknown/undoc (usually set) (zero after sending TX data?)
      24  SBRE  MBRE  RXRDY         (fifo not empty) (request data read)
      25  SBWE  MBWE  TXRQ          (datafifoempty?) (request data write)
      26  0     0     Unknown/unused (always 0)
      27  undoc undoc Unknown/undoc  (bit27 is mask-able in IRQ_MASK)
      28  0     0     Unknown/unused (always 0)
      29  undoc 0     CMD_READY? (inverse of BUSY?) (unlike toshiba ILFSL/IFSMSK)
      30  undoc 0     CMD_BUSY   (CMD_BUSY=0 shortly before CMD_READY=1?)
      31  ILA   IMSK  Illegal Command Access (old CMD still busy, or wrong NTDT)

Normally, IRQs should be acknowledged by writing "FLAGS=NOT X", whilst the firmware is using an unstable "FLAGS=FLAGS AND NOT X" read-modify-write function (accidentally acknowledging any IRQs that have newly occurred during that operation).
4004836h/4004A36h - SD_CARD_IRQ_STAT (R/ack)
4004838h/4004A38h - SD_CARD_IRQ_MASK (R/W)
IRQ Flags/Write (0=Acknowledge, 1=No change)
IRQ Flags/Read (0=No IRQ, 1=IRQ)
IRQ Mask (0=Enable, 1=Disable) (C007h when all IRQs disabled)

      Bit  Stat  Mask   Function
      15   undoc undoc  SomeIRQ (triggered SOMETIMES on forced CMDTIMEOUT?)
      14   undoc undoc  SomeIRQ (triggered near DATAEND?)
      13-3 0     0      Always zero
      2    undoc undoc  SomeIRQ (triggered on forced TXUNDERRUN?)
      1    undoc undoc  SomeIRQ (triggered about once per datablock?)
      0    CINT0 CIMSK0 CardIRQ (triggered by /IRQ aka Data1 pin; for SDIO devices)

All stat bits (except bit1) are triggered only if enabled in SD_CARD_IRQ_CTL.
Bit0 is actually used (for SDIO hardware), the other bits aren't used by existing software (they don't seem to be useful; purpose might be error testing, or forcing commands to abort).
4004834h/4004A34h - SD_CARD_IRQ_CTL (R/W)
CardIRQ Enable works only when also writing SD_CARD_PORT_SELECT.bit10=0 and only with valid SD_CARD_CLK_CTL setting.

      15-10  Always zero
      9      Enable setting SD_CARD_IRQ_STAT.bit14 and cause nothing special? (R/W)
      8      Enable setting SD_CARD_IRQ_STAT.bit15 and cause CMDTIMEOUT?      (R/W)
      7-3    Always zero
      2      Enable setting SD_CARD_IRQ_STAT.bit2 and cause TXUNDERRUN?       (R/W)
      1      Always zero
      0      Enable setting SD_CARD_IRQ_STAT.bit0 (CardIRQ upon Data1=LOW)    (R/W)

Bit9 is autocleared at time when bit9 causes setting SD_CARD_IRQ_STAT.bit14.
Bit2 is autocleared shortly before bit8 causes CMDTIMEOUT.
SD_CARD_IRQ_STAT.bit15 is set only when setting bit8 AND bit2 DURING cmd/xfer.
40048F8h/40048FAh - SD_EXT_IRQ_STAT0-1 - Interrupt Status (R/ack)
40048FCh/40048FEh - SD_EXT_IRQ_MASK0-1 - Interrupt Mask (R/W)
The 3DS bootroom is using bit0-2 for eMMC insert/eject detection. DSi software isn't doing such stuff (though the registers seem to exist in DSi hardware, too). Either way, eMMC cannot be ejected on neither DSi nor 3DS, so the feature is kinda useless.

      Bit   Stat  Mask  Function
      0     SCOT  MCOT  CARD_REMOVE (0=No event, 1=Is/was newly ejected)     ;\eMMC
      1     SCIN  MCIN  CARD_INSERT (0=No event, 1=Is/was newly inserted)    ; Slot
      2     undoc 1     SIGSTATE    (MMC: Always 1=Inserted) (SDIO: always 0);/Sw
      3     0     RW    Unknown (stat always 0, but mask is R/W)   ;\maybe another
      4     0     RW    Unknown (stat always 0, but mask is R/W)   ; unimplemented
      5     0     1     Unknown (stat always 0, and mask always 1) ;/device?
      6     0     RW    Unknown (stat always 0, but mask is R/W)   ;\maybe yet one
      7     0     RW    Unknown (stat always 0, but mask is R/W)   ; more?
      8-15  0     0     Unknown/unused (always 0)                  ;/
      16    ??    RW    Unknown (stat can be 0/1)               (R/W? or rather R?)
      17    ??    RW    Unknown (stat can be 0/1)               (R/W? or rather R?)
      18    ??    1     Unknown (1=normal, 0=data/read from card to fifo busy?) (R)
      19    0     RW    Unknown (stat always 0, but mask is R/W)
      20    0     RW    Unknown (stat always 0, but mask is R/W)
      21    0     1     Unknown (stat always 0, and mask always 1)
      22    0     RW    Unknown (stat always 0, but mask is R/W)
      23    0     RW    Unknown (stat always 0, but mask is R/W)
      24-31 0     0     Unknown/unused (always 0)

Some of the unknown bits might be CD/Data3 or IRQ/Data1 pins for Device 1, in similar way as for Device 0 (maybe that is in bit16-18, which are observed to become nonzero in certain situations).
EXT_IRQ_STAT can be 00000000h..00070004h for MMC, or always 00000000h for SDIO (as there's only one device on SDIO bus). EXT_IRQ_MASK is R/W (can be 00240024h..00FF00FFh) for both SD/MMC and SDIO.
4004900h/4004B00h - SD_DATA32_IRQ

      15-13  Always zero
      12     TX32RQ IRQ Enable   (0=Disable, 1=Enable)                       (R/W)
      11     RX32RDY IRQ Enable  (0=Disable, 1=Enable)                       (R/W)
      10     Clear FIFO32        (0=No change, 1=Force FIFO32 Empty)         (W)
      9      TX32RQ IRQ Flag     (0=IRQ, 1=No) (0=FIFO32 Empty)              (R)
      8      RX32RDY IRQ Flag    (0=No, 1=IRQ) (1=FIFO32 Full)               (R)
      7-2    Always zero
      1      Select 16bit/32bit Data Mode (0=DATA16, 1=DATA32, see 40048D8h) (R/W)
      0      Always zero

Bit8,9 are extra IRQ flags, the flags get set ONLY in DATA32 mode (not in DATA16 mode).
Bit8,9 are somewhat edge-triggered (setting the IF2 bit only on NoIRQ-to-IRQ transitions; whilst Disable-to-Enable transitions don't trigger IF2).
Bit8,9 don't need to be acknowledged, they are automatically switched to "No IRQ" by hardware (when reading/writing DATA32_FIFO, ie. when the FIFO is no longer empty/full).
400482Ch/4004A2Ch - SD_ERROR_DETAIL_STATUS0-1 - Error Detail Status (R)
This register contains extra info about the error bits in SD_IRQ_STATUS. The error bits (except bit13/always set) are automatically cleared when sending a new command by writing to SD_CMD.

      31-23 0      Always zero
      22    KBSY   Timeout for CRC status busy                          ;\STAT.19
      21    NWCS   Timeout for CRC status   (can occur for Data Write)  ; (SDTO)
      20    NRCS   Timeout for Data start-bit, or for Post Data Busy    ;/
      19-18 0      Always zero
      17    NRS    Response Timeout for auto-issued CMD12               ;\STAT.22
      16    NCR    Response Timeout for non-auto-issued CMD's           ;/(SCTO)
      15-14 0      Always zero
      13    undoc  Unknown/undoc (always 1)                             ;-Always 1
      12    0      Always zero
      11    WCRCE  CRC error for Write CRC status for a write command   ;\
      10    RCRCE  CRC error for Read Data                              ; STAT.17
      9     SCRCE  CRC error for a Response for auto-issued CMD12       ; (SCRC)
      8     CCRCE  CRC error for a Response for non-auto-issued CMD's   ;/
      5     WEBER  End bit error for Write CRC status                   ;\
      4     REBER  End bit error for Read Data                          ; STAT.18
      3     SEBER  End bit error for Response for auto-issued CMD12     ; (SEND)
      2     CEBER  End bit error for Response for non-auto-issued CMD's ;/
      1?    SCMDE  Bad CMD-index in Response of auto-issued CMD12       ;\STAT.16
      0     RCMDE  Bad CMD-index in Response of non-auto-issued CMD's   ;/(SCIX)

Note: CMD12 is STOP_TRANSMISSION (automatically sent after BLK_COUNT blocks).
The four "auto-issued CMD12" bits exist for SD registers only (not for SDIO, going by old toshiba datasheets; which may be wrong).
SCMDE is probably in bit1 (though, official specs say bit0, which would be same as RCMDE).
Some error bits can be intentionally provoked: Bit8=1 when programming the controller to expect GET_STATUS to return a 136bit response. Bit16=1 when sending GET_CID in "tran" state. Bit20=1 when sending GET_STATUS configured to expect a data/read reply. Bit21=1 when sending GET_STATUS configured to expect a data/write block (and with actually sending a data block to it).
40048F6h/4004AF6h - SD_WRPROTECT_2 (RESERVED4) (R)

      15-1   Always zero
      0      WRPROTECT_2 for onboard eMMC (usually/always 0=Unlocked)           (R)

Bit0 is write-protect flag for onboard eMMC (equivalent to the SD/MMC slot's write-protect switch in 400481Ch.bit7, but in inverted form: 0=Unlocked for eMMC, instead of 0=Locked for SD/MMC). The firmware does check bit0 (and, if set, hangs shortly before starting games), unknown if the TWL CPU and DSi mainboard do actually have any solder pads for it.
IRQ Edge-Triggering
One nasty "feature" for both IRQ_STATUS and DATA32_IRQ is that the interrupts are edge-triggered (IF2.bit8 gets set only on No-IRQ-to-IRQ transitions) (IF2 can be acknowledged even if IRQ(s) are still requested, which would mean that those IRQ(s) would get lost). Workaround would be:

     - first acknowledge IF2.bit8 (must be done before next step)
     - then check for pending IRQs in IRQ_STATUS and DATA32_IRQ, and process
       all of them

Ie. if you would process only a single IRQ, then any other IRQs would get lost.
For IRQ_STATUS, one could also force unprocessed IRQs to re-trigger IF2 by temporarily disabling IRQ_MASK bits (disable-to-enable for pending IRQs is also edge-triggering IF2). That trick works for IRQ_STATUS only, not for DATA32_IRQ.

DSi SD/MMC I/O Ports: Control Registers

4004802h/4004A02h - SD_CARD_PORT_SELECT

      15-11 Always zero
      10    Unknown (should be set on write) (reads as zero) (1=CardIRQ off!) (W)
      9-8   Unknown (Always 2 for SD/4004802h, always 1 for SDIO/4004A02h)    (R)
      7-4   Always zero
      3-1   Unknown (read/write-able)                                         (R/W)
      0     Port Select (0=SD Card Slot, 1=Onboard eMMC) (for SDIO: Unknown)  (R/W)

Known written values are 0400h and 0401h for SD/MMC. The register is left uninitialized for SDIO.
4004828h/4004A28h - SD_CARD_OPTION - Card Option Setup

      15   undoc Bus Width (0=4bit, 1=1bit)                                   (R/W)
      14   undoc Unknown (usually set)                                        (R?)
      13-9 0     Always zero
      8    undoc Unknown (firmware tries to toggle this after CLK change?)    (W?)
      7-4  RTO   Data start/busy timeout (2000h SHL 0..14, or 15=100h SDCLK's)(R/W)
      0-3  TO?   Unknown (another timeout, maybe for SDIO? in 32KHz units?)   (R/W)

See Timeout Notes below for details.
4004824h/4004A24h - SD_CARD_CLK_CTL Card Clock Control

      15-11 Always zero          ;unlike Toshiba: no HCLK divider-disable in bit15)
      10    Unknown (0=Normal, 1=Unknown, doesn't affect SDCLK output?)       (R/W)
      9     SDCLK Freeze     (0=Normal, 1=Freezes SDCLK output)               (R/W)
      8     SDCLK Pin Enable (0=Force SDCLK=LOW, 1=Output SDCLK=HCLK/n)       (R/W)
      7-0   HCLK Div (0,1,2,4,8,16,32,64,128 = Div2,4,8,16,32,64,128,256,512) (R/W)

The DSi uses HCLK=33.513982 MHz, the SDCLK pin can range from HCLK/512=65kHz to HCLK/2=16.757MHz, max transfer rate would be thus 8MByte/s in 4bit mode.
Max CLK speed:
Observe that card detection/initialization should be done at lower CLK rate than during normal operation.
For SD/MMC initialization: The DSi firmware starts with HCLK/128=262kHz (max allowed would be 400kHz for MMC). This is actually required: The DSi's onboard Samsung KMAPF0000M-S998 eMMC chip won't respond to ALL_GET_CID when trying to use 16MHz CLK). Higher CLK can be used once when detecting max speed (see TRAN_SPEED in CSD register; when extracting bits from CSD: mind the different 120bit-without-CRC vs 128bit-with-CRC notations).
For SDIO/Wifi initialization: The DSi firmware starts with HCLK/256=131kHz, and switches to HCLK/2=16.757MHz after reading SDIO Bus Speed register (Function0:00013h).
After init, one can use the detected speeds (see above), it should be also safe to assume that HCLK/2=16.757MHz is always supported after initialization (all SD devices should support at least 25MHz, and all(?) MMC devices at least 26MHz, and all DSi SDIO/Wifi boards should be fast enough either).
Notes:
The SDCLK pins are permanently pulsed, even for devices deselected via SD_CARD_PORT_SELECT.0, and even if no CMD or DATA is being transferred. However, the DSi firmware is usually stopping SDCLK via Bit8=0 when not accessing SD/MMC (doing so may reduce noise and power consumption).
Trying to set bit9, or to set more than one bit in bit7-0 will freeze the SDCLK output (in this case SDCLK may get stuck HIGH or LOW, unlike Bit8=0 which forces LOW).
Odd Effect: Setting bit10-8 to ALL ones, combined with an invalid HDIV (eg. writing 0703h) does disable CardIRQ on Data1 pin.
4004808h/4004A08h - SD_STOP_INTERNAL_ACTION

      15-9   Always zero
      8      Auto-Stop (1=Automatically send CMD12 after BLK_COUNT blocks)  (R/W)
      7-1    Always zero
      0      Unknown (firmware often clears this bit, but never sets it?)   (R/W)

Existing code does set bit8 (prior to changing SD_DATA16_BLK_COUNT).
Existing code does clear bit0 (alongsides with IRQ enable/acknowledge or so).
Note: Bit8 MUST be also set for SDIO with multiple blocks (although SDIO doesn't literally have CMD12).
40048E0h/4004AE0h - SD_SOFT_RESET - Software Reset

      15-3 Always zero
      2    Unknown (always 1)                                            (R?)
      1    Unknown (always 1) (though firmware tries to toggle this bit) (R?)
      0    SRST Soft Reset (0=Reset, 1=Release)                          (R/W)

Software should apply reset after sensing card insertion/removal, and (thereafter) release reset in case of card insertion. Software reset does acknowledge all IRQs (except that from SDIO /IRQ pin?), and does probably also reinitialize some other registers.
Clearing bit0 does force following settings (while and as long as Bit0=0):

      SD_STOP_INTERNAL_ACTION   = 0000h
      SD_RESPONSE0-7            = zerofilled
      SD_IRQ_STATUS0-1          = all IRQ flags acknowledged
      SD_ERROR_DETAIL_STATUS0-1 = all bits cleared (except bit13/always set)
      SD_CARD_CLK_CTL           = bit 8 and 10 cleared
      SD_CARD_OPTION            = 40EEh
      SD_CARD_IRQ_STAT          = 0000h
      Internal FIFO16 address is reset to first halfword of FIFO_A
      Reading FIFO16 returns 0000h (but old content reappears when releasing reset)

All other registers seem to be left unaffected (including the extra IRQ flags in 4004900h); though there may be some further hidden effects (like aborting transfers or resetting internal registers).
Note: The DSi firmware does issue reset by toggling both bit0 and bit1, although bit1 does seem to be read-only (always 1), and trying to clear that bit doesn't seem to have any effect at all.
Timeout Notes
Timeouts are counted in SDCLK units (the CLK-Pin rate selected in SD_CARD_CLK_CTL register). For Response-Timeouts, the timeout is fixed: Around 290h SDCLK's (preceeded by 30h SDCLK's for sending the command). For Data-Timeouts, the timeout can be selected in SD_CARD_OPTION.bit4-7, which is apparently what toshiba tried to describe as "RTO" bits. Values 0..14 select timeout "2000h SHL 0..14 SDCLK's" and value 15 selects "100h SDCLK's" (that, oddly, resulting in Data-timeout getting triggered before Response-timeout, which is rather nonsense since it's opposite of the actual transfer order).
For data/read, the timeout starts counting after transferring Command+Response. For data/write it starts after transferring Command+Response+DataBlock. The maximum duration for data timeouts (with RTO=14) would be around 8 seconds (at SDCLK=HCLK/2), or up to about 30 minutes (at HCLK/512).
One odd effect is that Response-Timeouts can occur (after 290h SDCLKs, and recursing the selected SDCLK=HCLK/n rate) even if SDCLK is stopped via SD_CARD_CLK_CTL.Bit8 (ie. the selected clock is kept running internally, and only the CLK-Pin output is forced LOW when Bit8=0).

DSi SD/MMC I/O Ports: Unknown/Unused Registers

Below registers don't seem to be used by existing software...
40048F2h/4004AF2h - Can be 0003h

      15-2   Always zero
      1-0    Unknown (0..3)                                                   (R/W)

40048F4h/4004AF4h - Can be 0770h

      15-11  Always zero
      10-8   Unknown (0..7)                                                   (R/W)
      7      Always zero
      6-4    Unknown (0..7)                                                   (R/W)
      3-0    Always zero

Unused Registers with Fixed value (all bits read-only, or write-only)

      400482Ah/4004A2Ah 2    Fixed always zero?
      4004832h/4004A32h 2    Fixed always zero?   ;(TC6371AF:BUF1 Data MSBs?)
      400483Ah/4004A3Ah 2    Fixed always zero?   ;(SDCTL_SDIO_HOST_INFORMATION)
      400483Ch/4004A3Ch 2    Fixed always zero?   ;(SDCTL_ERROR_CONTROL)
      400483Eh/4004A3Eh 2    Fixed always zero?   ;(TC6387XB: LED_CONTROL)
      4004840h/4004A40h 2    Fixed always 003Fh?
      4004842h/4004A42h 2    Fixed always 002Ah?
      4004844h/4004A44h 6Eh  Fixed always zerofilled?
      40048B2h/4004AB2h 2    Fixed always FFFFh?
      40048B4h/4004AB4h 6    Fixed always zerofilled?
      40048BAh/4004ABAh 2    Fixed always 0200h?
      40048BCh/4004ABCh 1Ch  Fixed always zerofilled?
      40048DAh/4004ADAh 6    Fixed always zerofilled?
      40048E2h/4004AE2h 2    Fixed always 0009h?  ;(RESERVED2/9, TC6371AF:CORE_REV)
      40048E4h/4004AE4h 2    Fixed always zero?
      40048E6h/4004AE6h 2    Fixed always zero?   ;(RESERVED3, TC6371AF:BUF_ADR)
      40048E8h/4004AE8h 2    Fixed always zero?   ;(TC6371AF:Resp_Header)
      40048EAh/4004AEAh 6    Fixed always zerofilled?
      40048F0h/4004AF0h 2    Fixed always zero?   ;(RESERVED10)
      4004902h/4004B02h 2    Fixed always zero?
      4004906h/4004B06h 2    Fixed always zero?
      400490Ah/4004B0Ah 2    Fixed always zero?
      4004910h/4004B10h F0h  Fixed always zerofilled?

DSi SD/MMC I/O Ports: Misc

Toshiba Chips
The DSi SDIO/MMC port addresses and status bits appear to be identical to those on Toshiba SD/MMC/SDIO controller chips.
One small difference is that the DSi can set SD_IRQ_MASK.Bit27 (which wasn't used on (older) Toshiba chips). The Toshiba chips seem to include additional "CNF" configuration registers (which seem to be missing on DSi).

      Chip             Year   Pages Features
      Toshiba TC6371AF 2000-2002 58 SD/MMC/Smart/PCI (old/basic specs, no SDIO)
      Toshiba TC6380AF 2001-2002 90 SD/MMC/SDIO/SmartMedia
      Toshiba TC6387XB 2001-2002 62 SD/MMC/SDIO/SDLED
      Toshiba TC6391XB 2002     202 SD/MMC/SDIO/SmartMedia/USB/LCD/etc.
      Toshiba TC6393XB ?  ;\unknown features, no datasheet exists (the chips
      Toshiba T7L66XB  ?  ;/are mentioned in tmio_mmc.h and tmio_mmc.c source)

The TC6380AF/TC6387XB/TC6391XB datasheets are more or less identical on the SD/MMC/SDIO section, TC6387XB is probably the best reference because it doesn't contain offtopic extras like SmartMedia, USB, LCD, etc. The datasheets contain I/O Maps with port addresses, but no description tables for the bits in those ports (though some bits are mentioned here and there in the text, scattered across many different pages, and other bits are left completely undocumented).

DSi SD/MMC Protocol: Command/Response/Register Summary

Basic Commands (class 0)

      CMD0     sd/mmc spi GO_IDLE_STATE (CMD0 with arg=stuff) (type=bc)
      CMD0     mmc        GO_PRE_IDLE_STATE (CMD0 with arg=F0F0F0F0h) (type=bc)
      CMD0     mmc        BOOT_INITIATION (CMD0 with arg=FFFFFFFAh, type=N/A)
      CMD1     sd/mmc spi SEND_OP_COND (On SD Cards: SPI only)
      CMD2     sd/mmc     ALL_GET_CID (type=bcr)
      CMD3     sd         GET_RELATIVE_ADDR (type=bcr)
      CMD3     mmc        SET_RELATIVE_ADDR (type=ac)
      CMD4     sd/mmc     SET_DSR (type=bc)
      CMD5     sd     spi Reserved for I/O cards (see "SDIO Card Specification")
      CMD5     mmc    ?   SLEEP_AWAKE (type=ac) (MMC only, IO_SEND_OP_COND on SDIO)
      CMD7     sd/mmc     SELECT_DESELECT_CARD (type=ac) ;actually: (type=bcr)
      CMD8     sd     spi SET_IF_COND (type=bcr)
      CMD8     mmc    spi GET_EXT_CSD (type=adtc)
      CMD9     sd/mmc spi GET_CSD (type=ac) (SPI: type=adtc)
      CMD10    sd/mmc spi GET_CID (type=ac) (SPI: type=adtc)
      CMD11    sd         VOLTAGE_SWITCH (type=ac)
      CMD12    sd/mmc spi STOP_TRANSMISSION (type=ac)
      CMD13    sd/mmc spi GET_STATUS (type=ac) (sends 16bit status in SPI Mode)
      CMD14    mmc        BUSTEST_R (type=adtc) (MMC only, Reserved on SD)
      CMD19    mmc        BUSTEST_W (type=adtc) (MMC only, SET_TUNING_BLOCK on SD)
      CMD15    sd/mmc     GO_INACTIVE_STATE (type=ac)

Block-Oriented Read Commands (class 2)

      CMD16    sd/mmc spi SET_BLOCKLEN (type=ac)
      CMD17    sd/mmc spi READ_SINGLE_BLOCK (type=adtc)
      CMD18    sd/mmc spi READ_MULTIPLE_BLOCK (type=adtc)
      CMD19    sd         SET_TUNING_BLOCK (type=adtc)
      CMD20    sd         SPEED_CLASS_CONTROL (type=ac)
      CMD22    sd         Reserved
      CMD23    sd/mmc-spi SET_BLOCK_COUNT (type=ac) (SPI supported ONLY on MMC?)

Block-Oriented Write Commands (class 4)

      CMD16    sd/mmc spi SET_BLOCKLEN (type=ac)
      CMD20    sd         SPEED_CLASS_CONTROL (type=ac)
      CMD23    sd/mmc-spi SET_BLOCK_COUNT (type=ac) (SPI supported ONLY on MMC?)
      CMD24    sd/mmc spi WRITE_BLOCK (type=adtc)
      CMD25    sd/mmc spi WRITE_MULTIPLE_BLOCK (type=adtc)
      CMD26    sd/mmc     Reserved For Manufacturer (MMC: PROGRAM_CID)
      CMD27    sd/mmc spi PROGRAM_CSD (type=adtc)

Block-Oriented Write-Protection Commands (class 6)

      CMD28    sd/mmc spi SET_WRITE_PROT (type=ac)
      CMD29    sd/mmc spi CLR_WRITE_PROT (type=ac)
      CMD30    sd/mmc spi GET_WRITE_PROT (type=adtc)
      CMD31    -          SD: Reserved
      CMD31    mmc        MMC: SEND_WRITE_PROT_TYPE (type=adtc)

Erase Commands (class 5)

      CMD32    sd     spi ERASE_WR_BLK_START (type=ac)
      CMD33    sd     spi ERASE_WR_BLK_END (type=ac)
      CMD32-34 mmc    spi Reserved for compatibility with older MMC cards (uh?)
      CMD35    mmc    spi ERASE_GROUP_START (type=ac)
      CMD36    mmc    spi ERASE_GROUP_END (type=ac)
      CMD37    mmc    spi Reserved for compatibility with older MMC cards (uh?)
      CMD38    sd/mmc spi ERASE (type=ac)
      CMD39    -          Reserved
      CMD41    -          Reserved

Lock Card (class 7)

      CMD16    sd/mmc spi SET_BLOCKLEN (type=ac)
      CMD40    sd         Defined by DPS Spec (Data Protection System) (type=adtc)
      CMD42    sd/mmc spi LOCK_UNLOCK (type=adtc)
      CMD43-47 -          Reserved
      CMD51    -          Reserved

Application-Specific Commands (class 8)

      CMD39-40 mmc        MMCA Optional Command, currently not supported
      CMD55-56 mmc        MMCA Optional Command, currently not supported
      CMD55    sd     spi APP_CMD (type=ac)    ;\also defined for MMC,
      CMD56    sd     spi GEN_CMD (type=adtc)  ;/but ONLY in SPI mode !!??
      CMD60-63 sd/mmc spi Reserved for manufacturer

I/O Mode Commands (class 9) (Refer to "SDIO Card Specification")

      CMD5     sdio   spi SDIO: IO_SEND_OP_COND
      CMD52    sdio   spi SDIO: IO_RW_DIRECT
      CMD53    sdio   spi SDIO: IO_RW_EXTENDED
      CMD54    -          SDIO: Reserved
      CMD39    mmcio      MMCIO: FAST_IO (type=ac)
      CMD40    mmcio      MMCIO: GO_IRQ_STATE (type=bcr)

Switch Function Commands (class 10) (version 1.10+)

      CMD6     mmc    spi SWITCH      (type=ac)   ;related to EXT_CSD register
      CMD6     sd     spi SWITCH_FUNC (type=adtc)
      CMD34-37 sd+spi     Reserved for Command Systems from CMD6  ;\SPI
      CMD50,57 sd+spi     Reserved for Command Systems from CMD6  ;/
      CMD34-35 sd         Reserved                                ;\
      CMD36-37 sd         Undoc (description field is held blank) ; Non-SPI
      CMD50,57 sd         Undoc (description field is held blank) ;/

Function Extension Commands (class 11)

      CMD21    sd         Reserved for DPS Specification (Data Protection System)
      CMD48    sd         READ_EXTR_SINGLE (type=adtc)
      CMD49    sd         WRITE_EXTR_SINGLE (type=adtc)
      CMD58    sd         READ_EXTR_MULTI (type=adtc)   ;SPI: READ_OCR
      CMD59    sd         WRITE_EXTR_MULTI (type=adtc)  ;SPI: CRC_ON_OFF

MMC Data Streaming Commands (class 1/class 3)

      CMD11    mmc        READ_DAT_UNTIL_STOP (class 1) (type=adtc)
      CMD20    mmc        WRITE_DAT_UNTIL_STOP (class 3) (type=adtc)

Below CMD58-59 SPI-only (in Non-SPI mode: MMC=Reserved, SD=EXTR_MULTI)

      CMD58    sd/mmc+spi READ_OCR     ;SPI-only ;SD Mode: READ_EXTR_MULTI
      CMD59    sd/mmc+spi CRC_ON_OFF   ;SPI-only ;SD Mode: WRITE_EXTR_MULTI

Above two commands are supported in SPI mode only, and are supported for both SD and MMC (though newer MMC docs are no longer mentioning them since JEDEC dropped SPI support).
Application Specific Commands (prefixed by CMD55 aka APP_CMD)

      ACMD6     sd        SET_BUS_WIDTH (type=ac)
      ACMD13    sd    spi SD_STATUS (type=adtc) (get 512bit SSR)
      ACMD22    sd    spi GET_NUM_WR_BLOCKS (type=adtc)
      ACMD23    sd    spi SET_WR_BLK_ERASE_COUNT (type=ac)
      ACMD41    sd    spi SD_SEND_OP_COND (type=bcr)  ;SPI: reduced functionality
      ACMD42    sd    spi SET_CLR_CARD_DETECT (type=ac)
      ACMD51    sd    spi GET_SCR (type=adtc)
      ACMD1-5   -         Reserved
      ACMD7-12  -         Reserved
      ACMD14-16 sd        Reserved for DPS Specification (Data Protection System)
      ACMD17    -         Reserved
      ACMD18    sd    spi Reserved for SD security applications
      ACMD19-21 -         Reserved
      ACMD24    -         Reserved
      ACMD25    sd    spi Reserved for SD security applications
      ACMD26    sd    spi Reserved for SD security applications
      ACMD27    -         Shall not use this command
      ACMD28    sd        Reserved for DPS Specification (Data Protection System)
      ACMD29    -         Reserved
      ACMD30-35 sd        Reserved for Security Specification
      ACMD36-37 -         Reserved
      ACMD38    sd    spi Reserved for SD security applications
      ACMD39-40 -         Reserved
      ACMD43-49 sd    spi Reserved for SD security applications
      ACMD52-54 sd        Reserved for Security Specification
      ACMD55    -         Not exist (equivalent to CMD55)
      ACMD56-59 sd        Reserved for Security Specification
      ACMD0     -         Unknown/Unused/Undocumented
      ACMD50    -         Unknown/Unused/Undocumented
      ACMD60-63 -         Unknown/Unused/Undocumented

Card Registers

      CSR       32bit  sd/mmc spi Card Status: command error & state information
      OCR       32bit  sd/mmc spi Operation Conditions Register
      CID      128bit  sd/mmc spi Card Identification
      CSD      128bit  sd/mmc spi Card-Specific Data (CSD Version 1.0 and 2.0)
      RCA       16bit  sd/mmc     Relative Card Address (not used in SPI mode)
      DSR       16bit  sd/mmc spi Driver Stage Register (optional)
      SSR      512bit  sd     spi SD Card Status Register: Extended status field
      SCR       64bit  sd     spi SD Card Configuration Register
      EXT_CSD 4096bit  mmc    spi MMC Extended CSD Register (status & config)
      PWD      128bit  sd/mmc spi Password (Card Lock) (max 16 bytes)
      PWD_LEN    8bit  sd/mmc spi Password Length (0..16 max) (0=no password)

SD Mode Response Types

      N/A    0bit  CMD0, CMD4, CMD15   No response
      R1    48bit  Normal CMDs/ACMDs   32bit CSR Card Status
      R1b   48bit  Busy CMDs/ACMDs     32bit CSR Card Status (and DATA=busy)
      R2   136bit  CMD9                120bit CSD Card-Specific Data
      R2   136bit  CMD2, CMD10         120bit CID Card Identification
      R3    48bit  ACMD41, MMC:CMD1    32bit OCR Register (without crc7)
      R4        -  -                   Reserved for SDIO
      R5        -  -                   Reserved for SDIO
      R6    48bit  CMD3                16bit RCA and cut-down 16bit CSR
      R7    48bit  CMD8                32bit Card interface condition

SPI Mode Response Types

      R1     8bit  Normal CMDs/ACMDs   8bit CSR Card Status
      R1b    8bit  Busy CMDs/ACMDs     8bit CSR Card Status (and DATA=busy)
      R2    16bit  CMD13, ACMD13       16bit CSR Card Status
      R3    40bit  CMD58               8bit CSR and 32bit OCR
      R4        -  -                   Reserved for SDIO
      R5        -  -                   Reserved for SDIO
      R6        -  -                   Reserved
      R7    40bit  CMD8                8bit CSR and 32bit Card interface condition
      ERROR  8bit  Only first 8bit sent upon Illegal Command or Command CRC Error

Commands with Data Transfers (additionally to command/response) (type=adtc)

      CMD17,18 R   sd/mmc spi READ_SINGLE_BLOCK, READ_MULTIPLE_BLOCK
      CMD24,25 W   sd/mmc spi WRITE_BLOCK, WRITE_MULTIPLE_BLOCK
      CMD8     R   mmc    spi GET_EXT_CSD (4096bit)
      CMD9     R   sd/mmc spi GET_CSD (128bit)  ;\in SPI Mode only (Non-SPI mode
      CMD10    R   sd/mmc spi GET_CID (128bit)  ;/sends that info as CMD response)
      ACMD13   R   sd     spi SD_STATUS (512bit SSR register)
      ACMD22   R   sd     spi GET_NUM_WR_BLOCKS (32bit counter)
      ACMD51   R   sd     spi GET_SCR (64bit SCR register)
      CMD14,19 R/W mmc        BUSTEST_R, BUSTEST_W
      CMD19    W?  sd         SET_TUNING_BLOCK (512bit tuning pattern)
      CMD27    W   sd/mmc spi PROGRAM_CSD (128bit CSD register)
      CMD30    R   sd/mmc spi GET_WRITE_PROT (32bit write-protect flags)
      CMD31    R   mmc        GET_WRITE_PROT_TYPE (32x2bit write-protect types)
      CMD42    W   sd/mmc spi LOCK_UNLOCK (password header/data)
      CMD6     ??  sd     spi SWITCH_FUNC
      CMD40    ?   sd         Defined by DPS Spec (Data Protection System)
      CMD48,49 R/W sd         READ_EXTR_SINGLE, WRITE_EXTR_SINGLE
      CMD58,59 R/W sd         READ_EXTR_MULTI, WRITE_EXTR_MULTI
      CMD56    R/W sd     spi GEN_CMD
      CMD11    R   mmc        READ_DAT_UNTIL_STOP (class 1) (type=adtc)
      CMD20    W   mmc        WRITE_DAT_UNTIL_STOP (class 3) (type=adtc)
     xR1b      R   sd/mmc spi Busy signal for commands with "R1b" response

Misnamed Commands
Official command names include various SEND_xxx commands, which are misleading because they don't indicate if they "send" information <to> or <from> the card (or both). Better naming would be GET_xxx, SET_xxx, or GET_SET_xxx.

      Official Name         Renamed
      ALL_SEND_CID          ALL_GET_CID
      SEND_CID              GET_CID
      SEND_CSD              GET_CSD
      SEND_STATUS           GET_STATUS
      SEND_RELATIVE_ADDR    GET_RELATIVE_ADDR
      SEND_SCR              GET_SCR
      SEND_EXT_CSD          GET_EXT_CSD
      SEND_WRITE_PROT       GET_WRITE_PROT
      SEND_WRITE_PROT_TYPE  GET_WRITE_PROT_TYPE
      SEND_NUM_WR_BLOCKS    GET_NUM_WR_BLOCKS
      SEND_IF_COND          SET_IF_COND             ;-to card
      SEND_TUNING_BLOCK     SET_TUNING_BLOCK        ;-to card
      SEND_OP_COND          ...
      SD_SEND_OP_COND       ...

Other misnamed commands include SET_BLOCKLEN occassionally spelled SET_BLOCK_LEN in SD specs. SELECT_DESELECT_CARD is officially spelled SELECT/DESELECT_CARD.
Difference of SD Commands Definition in UHS-II
SD-TRAN driver of host should manage the difference of SD commands functions. Not supported commands should not issue to UHS-II card. CMD13 shall not be issued during data transfer. Normally, data transfer should be stopped by setting TLEN instead of using CMD12.
CMD23 and CMD55 functions are included in UHS-II packet functions.

     CMD0   Terminate SD transaction and reset SD-TRAN state.
     CMD3   Returns Device ID in the response instead of RCA
     CMD4   Illegal
     CMD6   Function Group 1 and 3 are not used.
     CMD7   Device ID is set to the argument instead of RCA
     CMD13  Device operation is up to implementation during data transfer (eg. CTS)
     CMD11  Illegal
     CMD12  Normally, TLEN (data length) in UHS-II packet is used to stop data
            transfer.
     CMD12  Should be used to abort an operation when illegal situation occurs.
     CMD15  Illegal
     CMD19  Illegal
     CMD23  Not Affected. TLEN in UHS-II packet is used to specify data length.
     CMD55  Not Affected. ACMD is set by APP field in UHS-II packet.
     ACMD6  Illegal
     ACMD42 Illegal

Not Affected means that the command is not executed in any card state, and response is returned (response type is up to implementation).
Illegal means that card returns response with NACK=1.
As SDHC/SDXC Cards do not support CMD28, 29 and 30, these commands are also illegal in UHS-II mode.
Note
All future reserved commands shall have a codeword length of 48 bits, as well as their responses (if there are any).

DSi SD/MMC Protocol: General Commands

CMD0 - SD/MMC - SPI - GO_IDLE_STATE (type=bc)
Parameter bits:

      31-0  stuff bits

SD Mode Response: N/A
SPI Mode Response: R1
Resets all cards to idle state, it's usually sent to (re-)invoke card detection and initialization. The command does also seem to reset many further registers (for example, TRAN_SPEED is said to be reset to 25MHz, and, although not officially specified, the DSi's eMMC chip appears to get forced back to 1bit data bus mode).
Observe that card detection/initialization should be done at lower CLK rate than usually (MMC specifies max 400kHz - this is actually required - the DSi's onboard Samsung KMAPF0000M-S998 eMMC chip won't respond to ALL_GET_CID when trying to use 16MHz CLK), higher CLK can be used once when detecting max speed (TRAN_SPEED in CSD register).
The command is also used to enter SPI mode (in SPI mode, the /CS pin is held low, while in 1bit/4bit mode that pin would be DAT3=floating/high), SPI commands can be sent without CRCs, however, at time when entering SPI mode, memory cards may still insist on checksums, CMD0 should be thus always sent with CRC7.
CMD8 - SD (SD v2.00 and up) - SPI - SET_IF_COND (type=bcr)
Parameter bits:

      31-12 reserved bits
      11-8  supply voltage (VHS)
      7-0   check pattern

SD Mode Response: R7:

      47      Start Bit (0)                                 ;\
      46      Transmission To Host (0)                      ; 1st byte
      45-40   Command (the 6bit CMD being responded to)     ;/
      39-20   Reserved (zero filled)           (20bit)      ;\2nd..4th byte
      19-16   Voltage accepted (see below)     (4bit)       ;/
      23-8    Echo-back of check pattern       (8bit)       ;-5th byte
      7-1     CRC7                                          ;\6th byte
      0       End Bit (1)                                   ;/

SPI Mode Response: R7:

      39-32  R1 (8bit Card Status, same as in normal SPI command responses)
      31-28  Command version (???)         (4bit)
      27-12  Reserved (0)                  (16bit)
      11-8   Voltage Accepted (see below)  (4bit)
      7-0    Echo-back of check pattern    (8bit)

Sends SD Memory Card interface condition, which includes host supply voltage information and asks the card whether card supports voltage.
Voltage Accepted values:

      0001b  = 2.7-3.6V
      0010b  = Reserved for Low Voltage Range
      0100b  = Reserved
      1000b  = Reserved
      Others = Not Defined

The card supported voltage information of 3.3V range power pin is sent by the response of CMD8. Bits 19-16 indicate the voltage range that the card supports. The card that accepted the supplied voltage returns R7 response. In the response, the card echoes back both the voltage range and check pattern set in the argument.
CMD11 - SD - VOLTAGE_SWITCH (type=ac)
Parameter bits:

      31-0  reserved bits (0)

Response: R1
Switch to 1.8V bus signaling level.
CMD12 - SD/MMC - SPI - STOP_TRANSMISSION (type=ac)
Parameter bits:

      31-0  stuff bits

Response: R1b
Additional Data Transfer (from card): Busy signal for "R1b" response
Forces the card to stop transmission (SPI: in Multiple Block Read Operation).
Note: Toshiba SD/MMC controllers are sending STOP_TRANSMISSION automatically.
CMD15 - SD/MMC - GO_INACTIVE_STATE (type=ac)
Parameter bits:

      31-16 RCA
      15-0  reserved bits (0)

Response: N/A
Sends an addressed card into the Inactive State. This command is used when the host explicitly wants to deactivate a card once and forever (and won't even react to GO_IDLE_STATE) until next power-up (aka until ejecting/reinserting the card).
CMD59 - SD/MMC - SPI-ONLY (not Non-SPI Mode) - CRC_ON_OFF
Supported in SPI Mode only (in Non-SPI mode, CMD59 would be: MMC=Reserved, SD=WRITE_EXTR_MULTI)!
Parameter bits:

      31-1  stuff bits
      0     CRC option (0=off, 1=on)

SPI Mode Response: R1
Default on power up is unknown. Also unknown if this does completely prevent transmission of both CRC7 and CRC-CCITT values (especially in case of CID/CSD registers that have the CRC7 "inside" of the "128bit" register). Also unknown if CID/CSD are having "double" checksums (CRC7 plus CRC-CCITT) when transferring them as DATA packet (instead of as normal command/response).
ACMD6 - SD - SET_BUS_WIDTH (type=ac)

      31-2  stuff bits
      1-0   Bus width for Data transfers (0=1bit, 2=4bit, 1/3=reserved).

Response: R1
The supported widths can be found in SCR register. The current width is stored in SSR register. Default width is 1bit on power up.
Note: MMC uses a different mechanism to change the bus-width (via EXT_CSD).
ACMD42 - SD - SPI - SET_CLR_CARD_DETECT (type=ac)

      31-1  stuff bits
      0     set_cd (0=Disconnect, 1=Connect)

Response: R1
Connect/Disconnect the 50 KOhm pull-up resistor on CD/DAT3 pin of the card.
The pull-up might be intended for card detection (other than by using the slot's card detect switch), and/or for sensing SPI mode (which would drag that pin to LOW level when asserting /CS chip select).
During operation, disabling the pull-up might improve 4bit mode data transfers (unless for card controllers which do rely on the card pull-up to be present). The TC6387XB datasheet recommends external 100K pull-ups on DAT0-2, and only 47K on DAT3 (not quite sure why, unless Toshiba believed the parallel 50K+47K pull-ups to sum up to 100K, rather than to 25K).
CMD55 - SD/MMC (MMC: only in SPI-mode?) - SPI - APP_CMD (type=ac)

      31-16  RCA (SPI Mode: stuff bits)
      15-0   stuff bits

Response: R1
Used as prefix for application specific commands, ie. the next command will be treated as "ACMDnn" rather than as normal "CMDnn".
As the name says, this was originally intended for "application specific" extensions, however, in the SD Card protocol, it's also used for some ACMD's that are part of the SD protocol.
CMD56 - SD/MMC (MMC: only in SPI-mode?) - SPI - GEN_CMD (type=adtc)

      31-1  stuff bits
      0     RD/WR Direction (0=Write to Card, 1=Read from Card)

Response: R1
Additional Data Transfer (to/from card, depending on above R/W bit):

      General purpose data
      For SDSC, block length is set via SET_BLOCKLEN command.
      For SDHC/SDXC, block length is fixed to 512 bytes.

Used to transfer a data block to/from the card for general purpose/application specific commands.
CMD14 - MMC - BUSTEST_R (type=adtc) (MMC only, Reserved on SD)
CMD19 - MMC - BUSTEST_W (type=adtc) (MMC only, SET_TUNING_BLOCK on SD)

      31-0  stuff bits

Response: R1
Additional Data Transfer (to/from card):

      test pattern (2bit per DATA line? eg. 8bit pattern in 4bit-mode?)

MMC only. And, that, in Non-SPI mode only.
BUSTEST_W: Host sends the "bus TEST Data pattern" to card.
BUSTEST_R: Host reads the "REVERSED bus TESTING data pattern" from card.
The reversing is said to change a 2bit value of "01" into "10", unknown if that means that the bit-order is reversed, or that the bits are inverted.

DSi SD/MMC Protocol: Block Read/Write Commands

CMD16 - SD/MMC - SPI - SET_BLOCKLEN (type=ac)

      31-0  Block length (for Block Read, Block Write, Lock, and GEN_CMD)

Response: R1
In the case of SDSC Card, this command sets the block length (in bytes) for all following block commands (read, write, lock). Default block length is fixed to 512 Bytes. Set length is valid for memory access commands only if partial block read operation are allowed in CSD.
In the case of SDHC/SDXC Cards, block length set by CMD16 command does not affect memory read and write commands. Always 512 Bytes fixed block length is used. This command is effective for LOCK_UNLOCK command.
In both cases, if block length is set larger than 512 Bytes, the card sets the BLOCK_LEN_ERROR bit.
In DDR50 mode, block length must be even (because data is sampled on both clock edges).
CMD20 - SD (optional, see SCR.Bit32) - SPEED_CLASS_CONTROL (type=ac)

      31-28  Speed Class Control (for Block Read, and Block Write commands)
      27-0   Reserved (0)

Response: R1b
Additional Data Transfer (from card): Busy signal for "R1b" response
Speed Class control command. Refer to Section 4.13.2.8.
CMD23 - SD/MMC - SPI (but only on MMC) - SET_BLOCK_COUNT (type=ac)
Supported by SD and MMC Cards. However, in SPI-mode it's supported only for MMC? And, for SD it's optional (see SCR.Bit33).

      31-0  Block Count (MMC: only lower 16bit used, upper 16bit=reserved)

Response: R1
Specify block count for CMD18 and CMD25.

     ________________________ Block-Oriented READ Commands ________________________

CMD17 - SD/MMC - SPI - READ_SINGLE_BLOCK (type=adtc)

      31-0  data address (SDSC: in 1-byte units, SDHC/SDXC: in 512-byte units)

Response: R1
Additional Data Transfer (from card):

      data

In the case of SDSC Card, this command reads a block of the size selected by the SET_BLOCKLEN command. The data transferred shall not cross a physical block boundary unless READ_BLK_MISALIGN is set in the CSD.
In case of SDHC and SDXC Cards, block length is fixed 512 Bytes regardless of the SET_BLOCKLEN command.
CMD18 - SD/MMC - SPI - READ_MULTIPLE_BLOCK (type=adtc)

      31-0  data address (SDSC: in 1-byte units, SDHC/SDXC: in 512-byte units)

Response: R1
Additional Data Transfer (from card):

      data

Continuously transfers data blocks from card to host until interrupted by a STOP_TRANSMISSION command.
Block length is specified the same as READ_SINGLE_BLOCK command.
CMD19 - SD - SET_TUNING_BLOCK (type=adtc) (SD only, BUSTEST_W on MMC)

      31-0  reserved bits (0)

Response: R1
Additional Data Transfer (to card):

      64 bytes (512bit) tuning pattern is sent for SDR50 and SDR104.

     _______________________ Block-Oriented WRITE Commands _______________________

CMD24 - SD/MMC - SPI - WRITE_BLOCK (type=adtc)

      31-0  data address (SDSC: in 1-byte units, SDHC/SDXC: in 512-byte units)

Response: R1
Additional Data Transfer (to card):

      data

In case of SDSC Card, block length is set by the SET_BLOCKLEN command. The data transferred shall not cross a physical block boundary unless WRITE_BLK_MISALIGN is set in the CSD. In the case that write partial blocks is not supported, then the block length=default block length (given in CSD).
In case of SDHC and SDXC Cards, block length is fixed 512 Bytes regardless of the SET_BLOCKLEN command.
CMD25 - SD/MMC - SPI - WRITE_MULTIPLE_BLOCK (type=adtc)

      31-0  data address (SDSC: in 1-byte units, SDHC/SDXC: in 512-byte units)

Response: R1
Additional Data Transfer (to card):

      data

Continuously writes blocks of data until a STOP_TRANSMISSION follows.
Block length is specified the same as WRITE_BLOCK command.
ACMD22 - SD - SPI - GET_NUM_WR_BLOCKS (type=adtc)

      31-0  stuff bits

Response: R1
Additional Data Transfer (from card):

      31-0  Number of the written (without errors) write blocks (32bit)

Responds with 32bit+CRC data block.
If WRITE_BL_PARTIAL='0', the unit of ACMD22 is always 512 byte.
If WRITE_BL_PARTIAL='1', the unit of ACMD22 is a block length which was used when the write command was executed.
ACMD23 - SD - SPI - SET_WR_BLK_ERASE_COUNT (type=ac)

      31-23  stuff bits
      22-0   Number of blocks

Response: R1
Set the number of write blocks to be pre-erased before writing (to be used for faster Multiple Block WR command). "1"=default (one wr block).
Command STOP_TRAN (CMD12) shall be used to stop the transmission in Write Multiple Block whether or not the pre-erase (ACMD23) feature is used.

     _____________________ Byte-Streaming READ/WRITE Commands _____________________

CMD11 - MMC - READ_DAT_UNTIL_STOP (class 1) (type=adtc)
CMD20 - MMC - WRITE_DAT_UNTIL_STOP (class 3) (type=adtc)

      31-0  data address (SDSC: in 1-byte units, SDHC/SDXC: in 512-byte units)

Response: R1
Additional Data Transfer (to/from card):

      data

Similar to read/write multiple blocks, but transferring the data as an endless byte stream (instead of splitting it into separate blocks). Transfer is terminated by sending STOP_TRANSMISSION.

DSi SD/MMC Protocol: Special Extra Commands

     _________________________ Write PROTECTION Commands _________________________

CMD28 - SDSC/MMC (not SDHC/SDXC) - SPI - SET_WRITE_PROT (type=ac)
CMD29 - SDSC/MMC (not SDHC/SDXC) - SPI - CLR_WRITE_PROT (type=ac)

      31-0  data address (SDSC: in 1-byte units, SDHC/SDXC: Unsupported)

Response: R1b
Additional Data Transfer (from card): Busy signal for "R1b" response
Write protection support is indicated in CSD(WP_GRP_ENABLE), and additionally "class 6" should be flagged in CSD(CCC). The group size is indicated in CSD(WP_GRP_SIZE), observe that that field is 5bit/7bit wide for SD/MMC accordingly.
CMD30 - SDSC/MMC (not SDHC/SDXC) - SPI - GET_WRITE_PROT (type=adtc)

      31-0  data address (SDSC: in 1-byte units, SDHC/SDXC: Unsupported)

Response: R1
Additional Data Transfer (from card):

      31-0  Flags (1=write-protected) (bit0=addressed group, bit1..31=next groups)

If the card provides write protection features, this command asks the card to send the status of the write protection bits: 32 write protection bits (representing 32 write protect groups starting at the specified address) followed by 16 CRC bits are transferred in a payload format via the DATA line. The last (least significant) bit of the protection bits corresponds to the first addressed group. If the addresses of the last groups are outside the valid range, then the corresponding write protection bits shall be set to 0.
CMD31 - MMC - GET_WRITE_PROT_TYPE (type=adtc)

      31-0  data address (SDSC: in 1-byte units, SDHC/SDXC: Unsupported)

Response: R1
Additional Data Transfer (from card):

      63-0  Flags (1=write-protected) (bit0-1=addressed group, bit2..63=next)

Returns thirty-two 2bit values (0=not protected, 1=temporary write protection, 2=power-on write protection, 3=permanent write protection).
Further Write-Protection Mechanisms
The whole card can be write-protected via PERM_WRITE_PROTECT and TMP_WRITE_PROTECT bits in CSD register (supported for MMC and SDSC/SDHC/SDXC).
SD Cards (and SD Card adaptors for miniSD and microSD cards) are additionally having a mechanical "LOCK" write protection tab (MMC cards don't have that feature).
The PWD feature provides Read/Write-protection (when not knowing the password).

     _______________________________ Erase Commands _______________________________

CMD32 - SD - SPI - ERASE_WR_BLK_START (type=ac)
CMD33 - SD - SPI - ERASE_WR_BLK_END (type=ac)

      31-0  data address (SDSC: in 1-byte units, SDHC/SDXC: in 512-byte units)

Response: R1
Sets the address of the first/last write block of the continuous range to be erased.
CMD35 - MMC - SPI - ERASE_GROUP_START (type=ac)
CMD36 - MMC - SPI - ERASE_GROUP_END (type=ac)

      31-0  data address (MMC: in WHAT units?)

Response: R1
MMC only. Unknown, maybe similar to above SD commands?
CMD32-34,37 - SPI - MMC - Reserved for compatibility with older MMC cards
MMC only. Unknown, maybe also Erase related?
CMD38 - SD/MMC - SPI - ERASE (type=ac)

      31-0  stuff bits

Response: R1b
Additional Data Transfer (from card): Busy signal for "R1b" response
Erases all previously selected write blocks.
Further Erase Commands
Sectors are automatically erased on-the-fly when writing data blocks, so manually using above erase commands isn't really necessary; it may be useful for shreddering private data though, and it might also speed up subsequent writes since the writes can omit the on-the-fly erasing step.
The SET_WR_BLK_ERASE_COUNT (ACMD23) can be used to notify the card that it may pre-erase multiple sectors upon write commands (eg. to speed-up cluster writes that are spanning across multiple sectors).
The password lock feature includes a Forced Erase function, which will reset the password, and ERASE THE WHOLE CARD, this may be useful if the user has forgot the password, but will destroy data (possibly including the pre-formatted filesystem headers; which would be bad, because that headers should contain cluster sizes somewhat matched to the physical sector sizes).

     ________________________________ I/O Commands ________________________________

CMD5 - SD - SPI - Reserved for I/O cards
CMD52-54 - SD - SPI - Commands for SDIO

      CMD5  SDIO: IO_SEND_OP_COND
      CMD52 SDIO: IO_RW_DIRECT
      CMD53 SDIO: IO_RW_EXTENDED

Refer to the "SDIO Card Specification". SDIO is an extension to the SD protocol that allows to access non-memory-card hardware (such like cameras or network adaptors).

     __________________________ Switch Function Commands __________________________

CMD6 - SD (SD v1.10 and up) - SPI - SWITCH_FUNC (type=adtc)

      31     Mode (0=Check function, 1=Switch function)
      30-24  reserved (All '0')
      23-20  function group 6: Reserved (0h or Fh)
      19-16  function group 5: Reserved (0h or Fh)
      15-12  function group 4: Power Limit     ;SPI Mode: Reserved (0h or Fh)
      11-8   function group 3: Drive Strength  ;SPI Mode: Reserved (0h or Fh)
      7-4    function group 2: Command System
      3-0    function group 1: Access Mode

Response: R1
Additional Data Transfer (to/from whatever):

      unknown

Checks switch-able function (mode 0) and switch card function (mode 1). See Chapter 4.3.10.
CMD34-35 - SD - Reserved
Reserved for each command system set by switch function command (CMD6).
Detailed definition is referred to each command system specification.
Maybe related to above "function group 5..6"?
CMD36,37 - SD - Undoc (description field is held blank)
CMD50,57 - SD - Undoc (description field is held blank)
Undoc. Maybe related to above "function group 1..4"?
SPI: CMD34-37 - SD - SPI - Reserved for Command Systems from CMD6
SPI: CMD50,57 - SD - SPI - Reserved for Command Systems from CMD6
Described as so for SPI Mode. Maybe related to above "function group 1..6"?

     ________________________ Function Extension Commands ________________________

CMD21 - SD - Reserved for DPS Specification (Data Protection System)
Reserved.
CMD48 - SD (optional, see SCR.Bit34) - READ_EXTR_SINGLE (type=adtc)

      31     MIO (0=Memory, 1=I/O)
      30-27  FNO
      26     Reserved (0)
      25-9   ADDR
      8-0    LEN

Response: R1
Additional Data Transfer (from card):

      whatever

Single block read type. Refer to Section 5.7.2.1.
CMD49 - SD (optional, see SCR.Bit34) - WRITE_EXTR_SINGLE (type=adtc)

      31     MIO (0=Memory, 1=I/O)
      30-27  FNO
      26     MW
      25-9   ADDR
      8-0    LEN/MASK

Response: R1
Additional Data Transfer (to card):

      whatever

Single block write type. Refer to Section 5.7.2.2.
CMD58 - SD (optional, see SCR.Bit35) - READ_EXTR_MULTI (type=adtc)

      31     MIO (0=Memory, 1=I/O)
      30-27  FNO
      26     BUS (0=512B, 1=32KB)
      25-9   ADDR
      8-0    BUC

Response: R1
Additional Data Transfer (from card):

      whatever

Multi-block read type. Refer to Section 5.7.2.4.
CMD59 - SD (optional, see SCR.Bit35) - WRITE_EXTR_MULTI (type=adtc)

      31     MIO (0=Memory, 1=I/O)
      30-27  FNO
      26     BUS (0=512B, 1=32KB)
      25-9   ADDR
      8-0    BUC

Response: R1
Additional Data Transfer (to card):

      whatever

Multi-block write type. Refer to Section 5.7.2.5.
Note: CCC bit 11 is set to 1 when any command of class 11 is supported. Supporting of these commands is indicated in SCR register.

DSi SD/MMC Protocol: CSR Register (32bit Card Status Register)

CMD13 - SD/MMC - SPI - GET_STATUS (type=ac)
Parameter bits:

      31-16 RCA (SPI Mode: stuff bits)
      15-0  stuff bits

SD Mode Response: R1 (32bit Card Status):

      47      Start Bit (0)                                 ;\
      46      Transmission To Host (0)                      ; 1st byte
      45-40   Command (the 6bit CMD being responded to)     ;/
      39-8    CSR Card Status Register (32bit) (see below)  ;-2nd..5th byte
      7-1     CRC7                                          ;\6th byte
      0       End Bit (1)                                   ;/

SPI Mode Response: R2 (16bit Card Status):

      15-0    CSR Card Status Register (16bit) (see below)  ;-1st..2nd byte

Addressed card sends its status register.
CMDxx/ACMDxx - Other Commands
Most other commands are also returning the Card Status in their responses:
SD Mode Response: R1 (32bit Card Status)
SPI Mode Response: R1 (8bit Card Status; most SPI commands return only 8bit)
SPI Mode Response: R2 (16bit Card Status; SPI commands CMD13/ACMD return 16bit)
CMDxx/ACMDxx - Other Commands with R1b Response
R1b is identical to R1, with an optional busy signal transmitted on the DATA line (R1b occurs for CMD7, CMD12, CMD20, CMD28, CMD29, CMD38) (and for MMC: also for CMD5, CMD6). The card may become busy after receiving these commands based on its state prior to the command reception. The Host shall check for busy at the response.
In SD Mode, the busy signal is sent on DAT0 line (DAT1-3 aren't used, even if the card is in 4bit mode). The busy signal does consist of BITs? (not bytes?), and has a "start bit"?, followed by what-value-when-busy? and what-final-value-when-ready?
In SPI Mode, the busy signal is sent as BYTEs (00h=Busy, xxh=Nonzero=Ready).
CSR Card Status Register (full 32bit, as returned in SD Mode Response: R1)

      Bit  Typ Clr Identifier         Meaning
      31   ERX  C  OUT_OF_RANGE       (1=Command's argument was out of range)
      30   ERX  C  ADDRESS_ERROR      (1=Misaligned address/block len mismatch)
      29   ERX  C  BLOCK_LEN_ERROR    (1=Wrong block length, bytelen mismatch)
      28   ER   C  ERASE_SEQ_ERROR    (1=Error in erase command sequence)
      27   ERX  C  ERASE_PARAM        (1=Wrong erease selection of write-blocks)
      26   ERX  C  WP_VIOLATION       (1=Write failed due to write-protection)
      25   SX   A  CARD_IS_LOCKED     (1=Card is locked by the host)
      24   ERX  C  LOCK_UNLOCK_FAILED (1=Lock/unlock sequence or password error)
      23   ER   B  COM_CRC_ERROR      (1=CRC check of previous command failed)
      22   ER   B  ILLEGAL_COMMAND    (1=Command not legal for the card state)
      21   ERX  C  CARD_ECC_FAILED    (1=Internal error correction failed)
      20   ERX  C  CC_ERROR           (1=Internal card controller error)
      19   ERX  C  ERROR              (1=General error, or Unknown error)
      18   -    -  Reserved (eMMC: UNDERRUN)
      17   -    -  Reserved (eMMC: OVERRUN) (eSD: DEFERRED_RESPONSE)
      16   ERX  C  CSD_OVERWRITE      (1=read-only CSD section doesn't match card
                                      content, or attempted to reverse the
                                      Copy/WP bits)
      15   ERX  C  WP_ERASE_SKIP      (1=partial erase error due to write-protect)
      14   SX   A  CARD_ECC_DISABLED  (1=Internal error correction wasn't used)
      13   SR   C  ERASE_RESET        (1=Erase sequence was aborted)
      12-9 SX   B  CURRENT_STATE      (00h..0Fh=state, see below)
      8    SX   A  READY_FOR_DATA     (1=Ready/buffer is empty)
      7    EX   C  SWITCH_ERROR       (1=SWITCH command refused, MMC only)
      6    -    -  Reserved/Unspecified (description is left blank)
      5    SR   C  APP_CMD            (1=Card will expect ACMD)
      4    -    -  Reserved for SD I/O Card
      3    ER   C  AKE_SEQ_ERROR      (1=Authentication Sequence Error)
      2    -    -  Reserved for application specific commands
      1-0  -    -  Reserved for manufacturer test mode

Values for CURRENT_STATE (bit12-9):

      These bits indicate the OLD state of card when receiving the command,
      (ie. if the command does change the state, then the NEW state won't be
      seen until the NEXT command returns the new updated status bits)
      00h     = idle
      01h     = ready
      02h     = ident
      03h     = stby
      04h     = tran    ;<-- normal state (when waiting for read/write commands)
      05h     = data    ;data read  (CMD8,CMD11,CMD17,CMD18,CMD30,CMD56/R)
      06h     = rcv     ;data write (CMD20?,CMD24,CMD25,CMD26,CMD27,CMD42,CMD56/W)
      07h     = prg     ;erase/wprot (CMD6,CMD28,CMD29,CMD38)
      08h     = dis
      09h     = btst    ;bus test write (CMD19, MMC only)
      0Ah     = slp     ;sleep (CMD5, MMC only)
      0Bh-0Eh = reserved
      0Fh     = reserved for I/O mode (SDIO-only devices, without SD-memory)
      N/A     = ina     ;inactive (CMD15) (card is killed, and can't send status)
      N/A     = irq     ;interrupt mode (CMD40, MMC only)
      N/A     = pre     ;pre-idle (MMC only)

Type aka Typ column (in above table):

      E: Error bit.
      S: Status bit.
      R: Flag may get set within response of current command.
      X: Flag may get set within response of NEXT command (with R1 response)

Clear Condition aka Clr column (in above table):

      A: According to the card current state.
      B: Always related to the previous command. Reception of a valid command
         will clear it (with a delay of one command).
      C: Clear by read.

SPI Responses (8bit "R1" Responses, and 16bit "R2" Responses)

     FIRST BYTE of all SPI Responses:
      7  always 0                          ;\
      6  parameter error                   ; These 8bit are returned in ALL normal
      5  address error                     ; SPI commands (with 8bit "R1" response)
      4  erase sequence error              ; and,
      3  com crc error                     ; the same 8bits are also returned
      2  illegal command                   ; as FIRST BYTE in SPI commands with
      1  erase reset                       ; longer responses
      0  in idle state                     ;/
     SECOND BYTE of SPI "R2" Response:
      7  out of range, or csd overwrite           ;\
      6  erase param                              ;
      5  wp violation                             ; These extra 8bits are returned
      4  card ecc failed                          ; as SECOND BYTE in SPI commands
      3  CC error                                 ; with 16bit "R2" status response
      2  error                                    ; (ie. in CMD13 and ACMD13)
      1  wp erase skip, or lock/unlock cmd failed ;
      0  Card is locked                           ;/

Card Status Field/Command - Cross Reference
For each command responded by R1 response, following table defines the affected bits in the status field. An 'x' means the error/status bit may be set in the response to the respective command.

      Bits     31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12-9 8 5
      CMD3                             x  x        x                    x
      CMD6     x                 x     x  x  x  x  x                    x
      CMD7                 x  x  x  x  x  x  x  x  x        x  x  x  x  x    x
      CMD11                      x     x  x        x                    x
      CMD12    x  x           x  x     x  x  x  x  x              x     x
      CMD13    x  x        x  x  x  x  x  x  x  x  x        x  x  x     x    x
      CMD16          x     x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD17    x  x        x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD18    x  x        x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD19    x  x        x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD20    x  x  x     x  x  x  x  x  x  x  x  x        x  x  x  x  x    x
      CMD23    x  x  x     x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD24    x  x  x     x  x  x  x  x  x  x  x  x        x  x  x  x  x    x
      CMD25    x  x  x     x  x  x  x  x  x  x  x  x        x  x  x  x  x    x
      CMD26                x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD27                x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD28    x           x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD29    x           x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD30    x           x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD32    x        x  x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD33    x        x  x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD38             x  x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD42                x  x  x  x  x  x  x  x  x        x  x  x  x  x
      CMD48    x  x  x     x  x  x  x  x  x  x  x  x        x  x  x  x  x    x
      CMD49    x  x  x     x  x  x  x  x  x  x  x  x        x  x  x  x  x    x
      CMD55                x  x  x  x  x  x  x  x  x        x  x  x  x  x       x
      CMD56                x  x  x  x  x  x  x  x  x        x  x  x  x  x    x  x
      CMD58    x  x  x     x  x  x  x  x  x  x  x  x        x  x  x  x  x    x
      CMD59    x  x  x     x  x  x  x  x  x  x  x  x        x  x  x  x  x    x
      ACMD6    x           x  x  x  x  x  x  x  x  x        x  x  x  x  x       x
      ACMD13               x  x  x  x  x  x  x  x  x        x  x  x  x  x       x
      ACMD22               x  x  x  x  x  x  x  x  x        x  x  x  x  x       x
      ACMD23               x  x  x  x  x  x  x  x  x        x  x  x  x  x       x
      ACMD42               x  x  x  x  x  x  x  x  x        x  x  x  x  x       x
      ACMD51               x  x  x  x  x  x  x  x  x        x  x  x  x  x       x

Note: The response to CMD3 is R6 that includes only bits 23, 22, 19 and 12:9 out of the Card Status.

DSi SD/MMC Protocol: SSR Register (512bit SD Status Register)

ACMD13 - SD - SPI - SD_STATUS (type=adtc)

      31-0   stuff bits

SD Mode Response: R1 (32bit Card Status)
SPI Mode Response: R2 (16bit Card Status) (same as for CMD13, see there)
Additional Data Transfer (from card):

      511-0  SSR Register (512bit)

Send the SD Status. The status fields are given in Table 4-43.
SD Status (transferred on DATA line after ACMD13)
The size of the SD Status is one data block of 512 bit. The content of this register is transmitted to the Host over the DAT bus along with a 16-bit CRC.
ACMD13 can be sent to a card only in 'tran_state' (card is selected).

      Bits   Type Clr Identifier
      511-510  SR A   DAT_BUS_WIDTH (0..3, see below)
      509      SR A   SECURED_MODE  (0=Normal, 1=Secured) (Part 3 Security Specs)
      508-502  -  -   Reserved for Security Functions     (Part 3 Security Specs)
      501-496  -  -   Reserved
      495-480  SR A   SD_CARD_TYPE  (0..FFFFh, see below)
      479-448  SR A   SIZE_OF_PROTECTED_AREA   Size of protected area (see below)
      447-440  SR A   SPEED_CLASS      Speed Class of the card (see below)
      439-432  SR A   PERFORMANCE_MOVE Performance of move indicated by 1 MB/s step
      431-428  SR A   AU_SIZE          Size of AU (see below)
      427-424  -  -   Reserved
      423-408  SR A   ERASE_SIZE       Number of AUs to be erased at a time
      407-402  SR A   ERASE_TIMEOUT    Timeout value for erasing areas
                                       specified by UNIT_OF_ERASE_AU (see below)
      401-400  SR A   ERASE_OFFSET     Fixed offset value added to erase time
      399-396  SR A   UHS_SPEED_GRADE  Speed Grade for UHS mode  (see below)
      395-392  SR A   UHS_AU_SIZE      Size of AU  for UHS mode  (see below)
      391-312  -  -   Reserved
      311-0    -  -   Reserved for manufacturer

Values for DAT_BUS_WIDTH (as set via SET_BUS_WIDTH command):

      00h = 1 bit width (default)
      01h = reserved
      02h = 4 bit width
      03h = reserved

Values for SD_CARD_TYPE

      0000h = Regular SD RD/WR Card
      0001h = SD ROM Card
      0002h = OTP
      0004h,0008h,0010h,0020h,0040h,0080h = Reserved for future variations
      01xxh..FFxxh = Reserved for Cards that don't comply to Physical Layer Specs

Values for SIZE_OF_PROTECTED_AREA
Setting this field differs between SDSC and SDHC/SDXC.
In case of SDSC Card, the capacity of protected area is calculated as follows:

      Protected Area = SIZE_OF_PROTECTED_AREA_* MULT * BLOCK_LEN.
      SIZE_OF_PROTECTED_AREA is specified by the unit in MULT*BLOCK_LEN.

In case of SDHC and SDXC Cards, the capacity of protected area is calculated as follows:

      Protected Area = SIZE_OF_PROTECTED_AREA
      SIZE_OF_PROTECTED_AREA is specified by the unit in byte.

Values for SPEED_CLASS
This 8-bit field indicates the Speed Class. Classes lower than indicated by this field are also effective.

      00h      Speed Class 0
      01h      Speed Class 2
      02h      Speed Class 4
      03h      Speed Class 6
      04h      Speed Class 10
      05h-FFh  Reserved for future/faster classes

Application Note:
If a Class value indicated in SD Status (including reserved value) is larger than that of host supported, the host should read as any Class can be used with the card.
For example, Class 10 is indicated, host should consider Class 2 to 6 is also effective.
Values for PERFORMANCE_MOVE
This 8-bit field indicates Pm and the value can be set by 1 [MB/sec] step.
If the card does not move used RUs, Pm should be considered as infinity.
Setting to FFh means infinity.
Pm is defined for Class 2 to 6 in Default Speed Mode. When host uses Class 10, Pm indicated in SD Status shall be ignored and treated as 0.

      00h    Sequential Write
      01h    1 [MB/sec]
      02h    2 [MB/sec]
      ...    ...
      FEh    254 [MB/sec]
      FFh    Infinity

Values for AU_SIZE
This 4-bit field indicates AU Size and the value can be selected from 16 KB.

      00h    Not Defined
      01h    16 KB
      02h    32 KB
      03h    64 KB
      04h    128 KB
      05h    256 KB
      06h    512 KB
      07h    1 MB
      08h    2 MB
      09h    4 MB
      0Ah    8 MB
      0Bh    12 MB (!)
      0Ch    16 MB
      0Dh    24 MB (!)
      0Eh    32 MB
      0Fh    64 MB

Maximum AU size (depending on card capacity):

      Card Capacity     up to 64MB  up to 256MB  up to 512MB  up to 32GB  up to 2TB
      Maximum AU Size   512 KB      1 MB         2 MB         4 MB1       64MB

The card can set any AU size (up to above maximum AU size values).
The card should set smaller AU size as much as possible.
Application Notes:
The host should determine host buffer size based on total busy time of 4MB and the card supported class. The host can treat multiple AUs combined as one unit.
Values for ERASE_SIZE
This 16-bit field indicates NERASE. When NERASE numbers of AUs are erased, the timeout value is specified by ERASE_TIMEOUT (Refer to ERASE_TIMEOUT).
The host should determine proper number of AUs to be erased in one operation so that the host can indicate progress of erase operation.

      0000h    Erase Time-out Calculation is not supported.
      0001h    1 AU
      0002h    2 AU
      0003h    3 AU
      ...      ...
      FFFFh    65535 AU

Values for ERASE_TIMEOUT
This 6-bit field indicates the TERASE and the value indicates erase timeout from offset when multiple AUs are erased as specified by ERASE_SIZE. The range of ERASE_TIMEOUT can be defined as up to 63 seconds and the card manufacturer can choose any combination of ERASE_SIZE and ERASE_TIMEOUT depending on the implementation. Once ERASE_TIMEOUT is determined, it determines the ERASE_SIZE. The host can determine timeout for any number of AU erase by the Equation (6). Refer to 4.14 for the concept of calculating erase timeout. If ERASE_SIZE field is set to 0, this field shall be set to 0.

      00h      Erase Time-out Calculation is not supported.
      01h      1 [sec]
      02h      2 [sec]
      03h      3 [sec]
      ...      ...
      3Fh      63 [sec]

Values for ERASE_OFFSET
This 2-bit field indicates the TOFFSET and one of four values can be selected. The erase offset adjusts the line by moving in parallel on the upper side. Refer to Figure 4-57 and Equation (6) in 4.14. This field is meaningless if ERASE_SIZE and ERASE_TIMEOUT fields are set to 0.

      00h      0 [sec]
      01h      1 [sec]
      02h      2 [sec]
      03h      3 [sec]

Values for UHS_SPEED_GRADE
This 4-bit field indicates the UHS mode Speed Grade. Reserved values are for future speed grades larger than the highest defined value. Host shall treat reserved values (undefined) as highest grade defined.

      00h      Less than 10MB/sec
      01h      10MB/sec and above
      02h-0Fh  Reserved

Values for UHS_AU_SIZE
This 4-bit field indicates AU Size for UHS-I and UHS-II cards. Card should set smaller value as much as possible. Host shall refer to UHS_AU_SIZE instead of AU_SIZE when the card is operating in UHS-I or UHS-II bus speed modes.

      00h      Not Defined
      01h-06h  Not Used
      07h      1 MB
      08h      2 MB
      09h      4 MB
      0Ah      8 MB
      0Bh      12 MB (!)
      0Ch      16 MB
      0Dh      24 MB (!)
      0Eh      32 MB
      0Fh      64 MB

DSi SD/MMC Protocol: OCR Register (32bit Operation Conditions Register)

CMD1 (MMC) and ACMD41 (SD) are intended to exchange OCR information. That is, the OCR parameter bits should indicate the host conditions (eg. for DSi: 40100000h, ie. bit20=3.3V supply, and bit30=HCS support for High Capacity carts with more than 2GBytes). The OCR response may then return something like 007f8000h when busy, and 807f8000h when ready (bit20 indicating the voltage being actually supported, bit30 indicating if it's High Capacity card, and bit31 indicating if the card is ready & switched from "idle" to "ready" state).
Cards do usually send at least one response with bit31=0 (busy), one should repeat sending CMD1/ACMD51 until bit31=1 (ready).
Note: All card(s) on the bus will respond to CMD1/ACMD51: with the response bits ANDed together (thus returning nonsense in bit30=HCS when actually sharing the same bus for multiple cards).
Note: The card switches to "ina" state if the voltage in param bits isn't supported.
CMD1 - SD/MMC (For SD Cards: SPI-only) - SPI - SEND_OP_COND
Parameter For MMC Cards (supported in SPI and Non-SPI mode):

      31-0  OCR without busy (ie. without the power-up busy flag in bit31)

Parameter For SD Cards (supported in SPI mode only, not in Non-SPI mode):

      31    Reserved (0)                            ;\special case (applies
      30    HCS (Host Capacity Support information) ; to SD-cards in SPI-mode
      29-0  Reserved (0)                            ;/only)

SD Response: R1
MMC Response: R3 (same/similar as SD Mode's ACMD41 response, see below)
Sends host capacity support information and activates the card's initialization process. HCS is effective when card receives SET_IF_COND command.
ACMD41 - SD - SPI - SD_SEND_OP_COND (type=bcr)

      31     reserved bit
      30     HCS(OCR[30]) (Host Capacity Support information)
      29     reserved for eSD                 ;\
      28     XPC Max Power Consumption (watts); SPI Mode: Reserved
      27-25  reserved bits                    ; (ie. only bit30 is used for SPI)
      24     S18R                             ; (ie. ACMD41 is SAME as SPI CMD1 ?)
      23-0   VDD Voltage Window(OCR[23-0])    ;/

SD Mode Response: R3:

      47     Start Bit (0)                                 ;\
      46     Transmission To Host (0)                      ; 1st byte
      45-40  Reserved (111111) (instead of Command value)  ;/
      39-8   OCR (32bit)                                   ;-2nd..5th byte
      7-1    Reserved (111111) (instead of CRC7)           ;\6th byte
      0      End Bit (1)                                   ;/

SPI Mode Response: R1 (without extra Data transfer? use READ_OCR instead?)
Sends host capacity support information (HCS) and asks the accessed card to send its operating condition register (OCR) content in the response on the CMD line. HCS is effective when card receives SET_IF_COND command (uh, but IF_COND should be set BEFORE setting OP_COND?).
Sends request to switch to 1.8V signaling (S18R).
Reserved bit shall be set to '0'. CCS bit is assigned to OCR[30].
XPC controls the maximum power in the default speed mode of SDXC card.

      XPC=0: 0.36W (100mA at 3.6V on VDD1) (max) but speed class is not supported.
      XPC=1: 0.54W (150mA at 3.6V on VDD1) (max) and speed class is supported.

CMD58 - SD/MMC - SPI-ONLY (not Non-SPI Mode) - READ_OCR
Supported on SD Cards in SPI Mode only (in Non-SPI mode, CMD58 would be: MMC=Reserved, SD=READ_EXTR_MULTI)!
Parameter bits:

      31-0  stuff bits

SPI Mode Response: R3:

      39-32  R1 (8bit Card Status, same as in normal SPI command responses)
      31-0   OCR (32bit)

OCR register
The 32-bit operation conditions register stores the VDD voltage profile of the non UHS-II card and VDD1 voltage profile of the UHS-II card. Additionally, this register includes status information bits. One status bit is set if the card power up procedure has been finished. This register includes another status bit indicating the card capacity status after set power up status bit. The OCR register shall be implemented by the cards.
The 32-bit operation conditions register stores the VDD voltage profile of the card.
Bit 7 of OCR is newly defined for Dual Voltage Card and set to 0 in default. If a Dual Voltage Card does not receive CMD8, OCR bit 7 in the response indicates 0, and the Dual Voltage Card which received CMD8, sets this bit to 1.

      31     Card power up status bit (0=Busy, 1=Ready)
      30     Card Capacity Status (CCS) (valid only if above Bit31 indicates Ready)
              CCS=0   SDSC Card      (addressed in 1-byte units)   ;MMC max 2GB
              CCS=1   SDHC/SDXC card (addressed in 512-byte units) ;MMC > 2GB
      29     UHS-II Card Status
      28-25  Reserved
      24     Switching to 1.8V Accepted (S18A) (Only UHS-I card supports this bit)
      23     3.5-3.6                        ;\
      22     3.4-3.5                        ;
      21     3.3-3.4                        ;
      20     3.2-3.3 ;<-- this used by DSi  ;
      19     3.1-3.2                        ; VDD Voltage Window
      18     3.0-3.1                        ;
      17     2.9-3.0                        ;
      16     2.8-2.9                        ;
      15     2.7-2.8                        ;
      14-8   Reserved (MMC: 2.0V .. 2.6V)   ;  ;<-- uh, probably in opposite order?
      7      Reserved for Low Voltage Range ;
      6-4    Reserved                       ;
      3-0    Reserved                       ;/

The supported voltage range is coded as shown in Table 5-1. A voltage range is not supported if the corresponding bit value is set to LOW. As long as the card is busy, the corresponding bit (31) is set to LOW.
VDD Voltage Window of OCR indicates VDD1 voltage range in case of UHS-II Card.
UHS-II Card Status bit is added in Bit 29 to indicate whether the card supports UHS-II Interface. Non UHS-II Card sets Bit 29 to 0 and UHS-II Card sets Bit 29 to 1. This bit is not affected by whether VDD2 is supplied or not.

DSi SD/MMC Protocol: CID Register (128bit Card Identification)

CMD2 - SD/MMC - ALL_GET_CID (type=bcr)
CMD2 is/was intended for multiple MMC cards on the same SD/MMC bus, the connected card(s) should compare the CMD2 response bits seen on the bus, and the card with the smallest CID number is switched to "ident" state (and any other cards stay in "ready" state until sending further CMD2's).
CMD2 is still required for both SD and MMC during initialization, although actually sharing the same bus for multiple cards is rather uncommon/depracted (and might envolve various problems: Like conflicting OCR responses, conflicting pull-ups on DAT3 pin, signal noise/spikes on insertion/removal of a second card while accessing another card, problems with (shared) Write Protect and Card Detect switches, and so on).
Parameter bits:

      31-0  stuff bits

SD Mode Response: R2 (same 136bit response as for CMD10, see there)
Asks any card to send the CID numbers on the CMD line (any card that is connected to the host will respond - until it sees a "0" bit from another card while itself outputting a "1" bit).
Observe that CMD2 (and other card detection/initialization commands) should be done at lower CLK rate than usually (MMC specifies max 400kHz - this is actually required - the DSi's onboard Samsung KMAPF0000M-S998 eMMC chip won't respond to ALL_GET_CID when trying to use 16MHz CLK), higher CLK can be used once when detecting max speed (TRAN_SPEED in CSD register).
CMD10 - SD/MMC - SPI - GET_CID (type=ac)
This command should be used for actually READING the CID (as opposed to ALL_GET_CID which is primarily intended for the connected card(s) to COMPARE their CIDs with each other).
Parameter bits:

      31-16 RCA (SPI Mode: stuff bits)
      15-0  stuff bits

SD Mode Response: R2:

      135     Start Bit (0)                                 ;\
      134     Transmission To Host (0)                      ; 1st byte
      133-128 Reserved (111111) (instead of Command value)  ;/
      127-8   CID (120bit) (15 bytes)     ;\aka 128bit      ;-2nd..16th byte
      7-1     CRC7                        ; when including  ;\17th byte
      0       End Bit (1)                 ;/CRC7+EndBit     ;/

SPI Mode Response: R1, plus DATA line,
SPI Mode Additional Data Transfer (from card):

      127-0   CID (128bit) ... or 120bit ?

Addressed card sends its card identification (CID).
CID register
The Card IDentification (CID) register is 128 bits wide. It contains the card identification information used during the card identification phase. Every individual Read/Write (RW) card shall have a unique identification number.
For SD Cards (short product name, but bigger date field, 2000..2255?):

      Bit     Siz  Field  Name
      127-120   8  MID    Manufacturer ID    (binary) ;\assigned by SD-3C, LLC
      119-104  16  OID    OEM/Application ID (ASCII)  ;/
      103-64   40  PNM    Product name       (ASCII)
      63-56     8  PRV    Product revision   (BCD, 00h-99h) (eg 62h = rev 6.2)
      55-24    32  PSN    Product serial number (32bit)
      23-20     4  -      Reserved (zero)
      19-8     12  MDT    Manufacturing date (yymh) (m=1..12, yy=0..255?; +2000)
      7-1       7  CRC    CRC7 checksum
      0         1  1      Stop bit (always 1)

For MMC Cards (smaller date field, range 1997..2012 only):

      Bit     Siz  Field  Name
      127-120   8  MID    Manufacturer ID    (binary)   ;\assigned by MMCA
      119-104  16  OID    OEM/Application ID (binary)   ;/  ... or ...
      127-120   8  MID    Manufacturer ID    (binary)   ;\assigned by MMCA/JEDEC
      119-114   6  -      Reserved (0)                  ;
      113-112   2  CBX    Device (0=Card, 1=BGA, 2=POP) ;
      119-104   8  OID    OEM/Application ID (binary)   ;/
      103-56   48  PNM    Product name       (ASCII)
      55-48     8  PRV    Product revision   (BCD, 00h-99h) (eg 62h = rev 6.2)
      47-16    32  PSN    Product serial number (32bit)
      15-8      8  MDT    Manufacturing date (myh) (m=1..12, y=0..15; +1997)
      7-1       7  CRC    CRC7 checksum
      0         1  1      Stop bit (always 1)

Known CID's for DSi eMMC chips (excluding CRC in LSB, padded 00 in MSB)

      MY ss ss ss ss 03 4D 30 30 46 50 41 00 00 15 00  ;DSi Samsung KMAPF0000M-S998
      MY ss ss ss ss 32 57 37 31 36 35 4D 00 01 15 00  ;DSi Samsung KLM5617EFW-B301
      MY ss ss ss ss 30 36 35 32 43 4D 4D 4E 01 FE 00  ;DSi ST NAND02GAH0LZC5 rev30
      MY ss ss ss ss 31 36 35 32 43 4D 4D 4E 01 FE 00  ;DSi ST NAND02GAH0LZC5 rev31
      MY ss ss ss ss 03 47 31 30 43 4D 4D 00 01 11 00  ;3DS whatever chiptype?
      MY ss ss ss ss 07 43 59 31 47 34 4D 00 01 15 00  ;3DS Samsung KLM4G1YE0C-B301

See also:
DSi Console IDs

DSi SD/MMC Protocol: CSD Register (128bit Card-Specific Data)

CMD9 - SD/MMC - SPI - GET_CSD (type=ac)
Parameter bits:

      31-16 RCA (SPI Mode: stuff bits)
      15-0  stuff bits

SD Mode Response: R2:

      135     Start Bit (0)                                 ;\
      134     Transmission To Host (0)                      ; 1st byte
      133-128 Reserved (111111) (instead of Command value)  ;/
      127-8   CSD (120bit) (15 bytes)     ;\aka 128bit      ;-2nd..16th byte
      7-1     CRC7                        ; when including  ;\17th byte
      0       End Bit (1)                 ;/CRC7+EndBit     ;/

SPI Mode Response: R1, plus DATA line,
SPI Mode Additional Data Transfer (from card):

      127-0   CID (128bit) ... or 120bit ?

Addressed card sends its card-specific data (CSD).
CMD27 - SD/MMC - SPI - PROGRAM_CSD (type=adtc)

      31-0  stuff bits

Response: R1
Additional Data Transfer (to card):

      128-0  CSD register (whole 128bit) (read-only bits must be unchanged)

Programming of the programmable bits of the CSD, ie. the "R/W" bits, the "R" bits must be kept unchanged (read via CMD9, and write-back same values via CMD27).
The writable once "R/W(1)" bits can be changed only from 0-to-1, or vice-versa, they can be really written only ONCE, by the manufacturer?
Most of the "R/W(1)" bits are probably set by the manufacturer at time when pre-formatting the card, so they aren't actually user-writeable.
CSD Register
The types of the entries in the table below are coded as follows: R=readable, W(1)=writable once, W=multiple writable.

      Bit    Siz Type   Name                             Field             Value
      127-126 2  R      CSD structure version            CSD_STRUCTURE     00b
      125-122 4  R      MMC: System spec version         SPEC_VERS         ..
      125-122 4  R      SD: reserved                     -                 0000b
      121-120 2  R      reserved                         -                 00b
      119-112 8  R      data read access-time-1          TAAC              xxh
      111-104 8  R      data read access-time-2          NSAC              xxh
      103-96  8  R      max data transfer rate           TRAN_SPEED   32h or 5Ah
      95-84  12  R      card command classes             CCC          01x110110101b
      83-80   4  R      max read data block len          READ_BL_LEN          xh
      79      1  R      partial blocks for read allowed  READ_BL_PARTIAL      1b
      78      1  R      write block misalignment         WRITE_BLK_MISALIGN   xb
      77      1  R      read block misalignment          READ_BLK_MISALIGN    xb
      76      1  R      DSR implemented                  DSR_IMP              xb
      75-74   2  R      reserved                              -               00b
      73-70   4  R      SDHC/SDXC: reserved                   -               0000b
      69-48  22  R      SDHC/SDXC: device size                C_SIZE          ...
      47      1  R      SDHC/SDXC: reserved                   -               0
      73-62  12  R      MMC/SDSC: device size                 C_SIZE          xxxh
      61-59   3  R      MMC/SDSC: max read current @VDD min   VDD_R_CURR_MIN  xxxb
      58-56   3  R      MMC/SDSC: max read current @VDD max   VDD_R_CURR_MAX  xxxb
      55-53   3  R      MMC/SDSC: max write current @VDD min  VDD_W_CURR_MIN  xxxb
      52-50   3  R      MMC/SDSC: max write current @VDD max  VDD_W_CURR_MAX  xxxb
      49-47   3  R      MMC/SDSC: device size multiplier      C_SIZE_MULT     xxxb
      46-42   5  R      MMC: Erase Group Size             ERASE_GRP_SIZE   ..
      41-37   5  R      MMC: Erase Group Multiplier       ERASE_GRP_MULT   ..
      36-32   5  R      MMC: Write Protect Grp Size       WP_GRP_SIZE      ..
      46      1  R      SD: erase single block enable     ERASE_BLK_EN     xb
      45-39   7  R      SD: erase sector size             SECTOR_SIZE      xxxxxxxb
      38-32   7  R      SD: write protect group size      WP_GRP_SIZE      xxxxxxxb
      31      1  R      write protect group enable        WP_GRP_ENABLE    xb
      30-29   2  R      MMC: Manufacturer default ECC     DEFAULT_ECC      ..
      30-29   2  R      SD: reserved (do not use)         -                00b
      28-26   3  R      write speed factor                R2W_FACTOR       xxxb
      25-22   4  R      max write data block len          WRITE_BL_LEN     xxxxb
      21      1  R      partial blocks for write allowed  WRITE_BL_PARTIAL xb
      20-17   4  R      reserved                          -                0000b
      16      1  R      SD: reserved                      -                0
      16      1  R      MMC: Content Protection Applicat. CONTENT_PROP_APP ..
      15      1  R/W(1) File format group                 FILE_FORMAT_GRP  xb
      15      1  R      SDHC/SDXC: reserved               (FILE_FORMAT_GRP)0
      14      1  R/W(1) copy flag                         COPY             xb
      13      1  R/W(1) permanent write protection     PERM_WRITE_PROTECT  xb
      12      1  R/W    temporary write protection     TMP_WRITE_PROTECT   xb
      11-10   2  R/W(1) File format                    FILE_FORMAT         xxb
      11-10   2  R      SDHC/SDXC: reserved            (FILE_FORMAT)       00b
      9-8     2  R/W    MMC: ECC Code                  ECC                 ..
      9-8     2  R/W    SDSC: reserved, R/W            -                   00b
      9-8     2  R      SDHC/SDXC: reserved, R         -                   00b
      7-1     7  R/W    CRC                            CRC                 xxxxxxxb
      0       1  -      not used, always '1'           -                   1b

Known CSD's for DSi eMMC chips (excluding CRC in LSB, padded 00 in MSB)

      8  16 24 32 40 48 56 64 72 80 88 96 104112120pad ;<--bit numbers
      40 40 96 E9 7F DB F6 DF 01 59 0F 2A 01 26 90 00  ;DSi Samsung KMAPF0000M-S998
      40 40 8E FF 03 DB F6 DF 01 59 0F 32 01 27 90 00  ;DSi Samsung KLM5617EFW-B301
      00 40 8A E0 BF FF 7F F5 80 59 0F 32 01 2F 90 00  ;DSi ST NAND02GAH0LZC5 rev30
      00 40 8A E0 BF FF 7F F5 80 59 0F 32 01 2F 90 00  ;DSi ST NAND02GAH0LZC5 rev31
      ?                                            00  ;3DS whatever chiptype?
      40 40 8A E7 FF DB F6 6B 02 5A 0F 32 01 27 D0 00  ;3DS Samsung KLM4G1YE0C-B301

That is, differences are:

      bit     name            KMAPF0000M  KLM5617EFW NAND02GAH0LZC5 KLM4G1YE0C
      126-127 CSD_STRUCTURE   2=v1.2      2=v1.2     2=v1.2         3=SeeEXT_CSD
      112-119 TAAC            26h=1.5ms   27h=15ms   2Fh=20ms       27h=15ms
      96-103  TRAN_SPEED      2Ah=20MHz   32h=25MHz  32h=25MHz      32h=25MHz
      80-83   READ_BL_LEN     9=512       9=512      9=512          0Ah=1024
      79      READ_BL_PARTIAL 0=No(?)     0=No(?)    1=Yes          0=No(?)
      62-73   C_SIZE          77Fh=240MB  77Fh=240MB 3D5h=245.5MB   9AFh=1240MB
      59-61   VDD_R_CURR_MIN  6=60mA      6=60mA     7=100mA        6=60mA
      56-58   VDD_R_CURR_MAX  6=80mA      6=80mA     7=200mA        6=80mA
      53-55   VDD_W_CURR_MIN  6=60mA      6=60mA     7=100mA        6=60mA
      50-52   VDD_W_CURR_MAX  6=80mA      6=80mA     7=200mA        6=80mA
      47-49   C_SIZE_MULT     6=256       6=256      7=512          7=512
      42-46   ERASE_GRP_SIZE  1Fh=32x32   00h=1x32   1Fh=32x32      1Fh=32x32
      32-36   WP_GRP_SIZE     09h=10      1Fh=32     00h=1          07h=8
      26-28   R2W_FACTOR      05h=32x     03h=8x     02h=4x         02h=4x
      14      COPY            1=Copy      1=Copy     0=Original     1=Copy

Not sure if that values are really correct, or if the manufacturer has screwed up some bits. TAAC being 10x slower in newer chips looks weird, 20MHz would be for 1bit MCC (whilst 4bit MMCplus/MMCmobile should support 26MHz), erase group 32x32x512 bytes would somewhat require 512Kbyte clusters, write protect group size 10 decimal looks a bit odd (though it could be true), and, well, faster writing in newer chips looks plausible.
CSD_STRUCTURE (upper 2bit of CSD register)
Field structures of the CSD register are different depend on the Physical Layer Specification Version and Card Capacity.
The CSD_STRUCTURE field in the CSD register indicates its structure version.
For MMC:

      00h      CSD version No. 1.0    MMC Version 1.0 - 1.2
      01h      CSD version No. 1.1    MMC Version 1.4 - 2.2
      02h      CSD version No. 1.2    MMC Version 3.1 - 3.2 - 3.31 - 4.0 - 4.1- 4.2
      03h      Version is coded in the CSD_STRUCTURE byte in the EXT_CSD register

For SD:

      00h      CSD Version 1.0   SDSC (Standard Capacity)
      01h      CSD Version 2.0   SDHC/SDXC (High Capacity and Extended Capacity)
      02h-03h  Reserved

SDHC/SDXC applies major changes to CSD register (C_SIZE is expanded, and many other fields are removed or set to dummy values), for details see:
DSi SD/MMC Protocol: CSD Register (128bit Card-Specific Data) Version 2.0
SPEC_VERS (MMC only)

      00h       MMC System Specification Version 1.0 - 1.2
      01h       MMC System Specification Version 1.4
      02h       MMC System Specification Version 2.0 - 2.2
      03h       MMC System Specification Version 3.1 - 3.2 - 3.31
      04h       MMC System Specification Version 4.0 - 4.1 - 4.2
      05h-0Fh   Reserved

TAAC
Defines the asynchronous part of the data access time.

      7    Reserved
      6-3  Time value
             0=reserved, 1=1.0, 2=1.2, 3=1.3, 4=1.5, 5=2.0, 6=2.5, 7=3.0,
             8=3.5, 9=4.0, A=4.5, B=5.0, C=5.5, D=6.0, E=7.0, F=8.0
      2-0  Time unit
             0=1ns, 1=10ns, 2=100ns, 3=1us, 4=10us, 5=100us, 6=1ms, 7=10ms

NSAC
Defines the worst case for the clock-dependent factor of the data access time. The unit for NSAC is 100 clock cycles. Therefore, the maximal value for the clock-dependent part of the data access time is 25500 clock cycles.
The total access time NAC is the sum of TAAC and NSAC. It should be computed by the host for the actual clock rate. The read access time should be interpreted as a typical delay for the first data bit of a data block or stream.
TRAN_SPEED
The following table defines the maximum data transfer rate PER ONE data line:

      7    Reserved
      6-3  Time value
             0=reserved, 1=1.0, 2=1.2, 3=1.3, 4=1.5, 5=2.0, 6=2.5, 7=3.0,
             8=3.5, 9=4.0, A=4.5, B=5.0, C=5.5, D=6.0, E=7.0, F=8.0
      2-0  Transfer rate unit
             0=100kbit/s, 1=1Mbit/s, 2=10Mbit/s, 3=100Mbit/s, 4..7=reserved
             MMC: same as above, but specified in <Hz> instead of <bits/s>

Note that for current SD Memory Cards, this field shall be always 32h which is equal to 25 MHz - the mandatory maximum operating frequency of SD Memory Card.
In High-Speed mode, this field shall be always 5Ah which is equal to 50 MHz, and when the timing mode returns to the default by CMD6 or CMD0 command, its value will be 32h.
CCC (Card Command Class)
The SD Memory Card command set is divided into subsets (command classes). A value of 1 in a CCC bit means that the corresponding command class is supported. For command class definitions, refer to Table 4-21.

      11   Supports Command Class 11 - Function Extension Commands (SD)
      10   Supports Command Class 10 - Switch Function Commands (SD)
      9    Supports Command Class 9 - I/O Mode Commands (SDIO/MMCIO)
      8    Supports Command Class 8 - Application-Specific Commands
      7    Supports Command Class 7 - Password Lock Commands
      6    Supports Command Class 6 - Block-Oriented Write Protection Commands
      5    Supports Command Class 5 - Erase Commands
      4    Supports Command Class 4 - Block-Oriented Write Commands
      3    Supports Command Class 3 - WRITE_DAT_UNTIL_STOP (MMC)
      2    Supports Command Class 2 - Block-Oriented Read Commands
      1    Supports Command Class 1 - READ_DAT_UNTIL_STOP (MMC)
      0    Supports Command Class 0 - Basic Commands

Same for MMC (though on MMC the classes may have different meaning?)
READ_BL_LEN
The maximum read data block length is computed as 2^READ_BL_LEN. The maximum block length might therefore be in the range 512...2048 bytes (Refer to 4.3.3 for details). Note that in an SD Memory Card the WRITE_BL_LEN is always equal to READ_BL_LEN.

      3-0  Setting

Values:

      00h..08h  Reserved
      09h       Block length 512 Bytes (2^9)
      0Ah       Block length 1024 Bytes (2^10)
      0Bh       Block length 2048 Bytes (2^11)
      0Ch..0Fh  Reserved

MMC allows any values from 2^0 to 2^14, and uses 0Fh for Extension (see TBD field in EXT_CSD) (uh, but "TBD" isn't yet defined in KMCEN0000M datasheet, maybe TBD means to-be-defined?).
READ_BL_PARTIAL (always = 1 in SDSC Memory Card)
Partial Block Read is always allowed in an SDSC Memory Card. It means that smaller blocks can be used as well. The minimum block size will be one byte.
WRITE_BLK_MISALIGN
Defines if the data block to be written by one command can be spread over more than one physical block of the memory device. The size of the memory block is defined in WRITE_BL_LEN.

      WRITE_BLK_MISALIGN=0   crossing physical block boundaries is invalid
      WRITE_BLK_MISALIGN=1   crossing physical block boundaries is allowed

READ_BLK_MISALIGN
Defines if the data block to be read by one command can be spread over more than one physical block of the memory device. The size of the memory block is defined in READ_BL_LEN.

      READ_BLK_MISALIGN=0    crossing physical block boundaries is invalid
      READ_BLK_MISALIGN=1    crossing physical block boundaries is allowed

DSR_IMP
Defines if the configurable driver stage is integrated on the card. If set, a driver stage register (DSR) shall be implemented (also see Chapter 5.5).

      DSR_IMP=0    no DSR implemented
      DSR_IMP=1    DSR implemented

C_SIZE (for max 2GB)
This parameter is used to compute the user's data card capacity (not include the security protected area). The memory capacity of the card is computed from the entries C_SIZE, C_SIZE_MULT and READ_BL_LEN as follows:

      memory capacity = BLOCKNR * BLOCK_LEN

Whereas,

      BLOCKNR = (C_SIZE+1) * MULT
      MULT = 2^(C_SIZE_MULT+2)    ;(C_SIZE_MULT < 8)
      BLOCK_LEN = 2^READ_BL_LEN   ;(READ_BL_LEN < 12)

To indicate 2 GByte card, BLOCK_LEN shall be 1024 bytes.
Therefore, the maximal capacity that can be coded is 4096*512*1024 = 2 G bytes.
Example: A 32 Mbyte card with BLOCK_LEN = 512 can be coded by C_SIZE_MULT = 3 and C_SIZE = 2000.
The Maximum Data Area size of SDSC Standard Capacity Card is 4,153,344 sectors (2028MB).
C_SIZE (for MMC above 2GB)
The 12bit C_SIZE field should be set 0FFFh. Use "SEC_COUNT" in EXT_CSD to specify actual size.
VDD_R_CURR_MIN, VDD_W_CURR_MIN
Maximum values for read and write currents at the MINIMAL power supply VDD:

      2-0   0=0.5mA, 1=1mA, 2=5mA, 3=10mA, 4=25mA, 5=35mA, 6=60mA, 7=100mA

VDD_R_CURR_MAX, VDD_W_CURR_MAX
Maximum values for read and write currents at the MAXIMAL power supply VDD:

      2-0   0=1mA, 1=5mA, 2=10mA, 3=25mA, 4=35mA, 5=45mA, 6=80mA, 7=200mA

C_SIZE_MULT
This parameter is used for coding a factor MULT for computing the total device size (see 'C_SIZE'). Defined as "MULT = 2^(C_SIZE_MULT+2)".

      2-0   Device Size Factor (0..7 = Factor 4,8,16,32,64,128,256,512)

SD: ERASE_BLK_EN
The ERASE_BLK_EN defines the granularity of the unit size of the data to be erased. The erase operation can erase either one or multiple units of 512 bytes or one or multiple units (or sectors) of SECTOR_SIZE (see definition below).
If ERASE_BLK_EN=0, the host can erase one or multiple units of SECTOR_SIZE. The erase will start from the beginning of the sector that contains the start address to the end of the sector that contains the end address. For example, if SECTOR_SIZE=31 and the host sets the Erase Start Address to 5 and the Erase End Address to 40, the physical blocks from 0 to 63 will be erased as shown in Figure 5-1.

      Figure 5-1: ERASE_BLK_EN = 0 Example
      Physical Block (per CSD)
      0          1          2          3          4          5          6
      0123456789 0123456789 0123456789 0123456789 0123456789 0123456789 0123456789
           <----- Host Erase Address Range ------->
      <---------- Erase Area ---------------------------------------------->
      <---------- Erase Unit Size ------><------- Erase Unit Size --------->

If ERASE_BLK_EN=1 the host can erase one or multiple units of 512 bytes. All blocks that contain data from start address to end address are erased. For example, if the host sets the Erase Start Address to 5 and the Erase End Address to 40, the physical blocks from 5 to 40 will be erased as shown in Figure 5-2.

      Figure 5-2: ERASE_BLK_EN = 1 Example
      Physical Block (per CSD)
      0          1          2          3          4          5          6
      0123456789 0123456789 0123456789 0123456789 0123456789 0123456789 0123456789
           <----- Host Erase Address Range ------->
           <----- Erase Area --------------------->

SD: SECTOR_SIZE
The size of an erasable sector. The content of this register is a 7-bit binary coded value, defining the number of write blocks (see WRITE_BL_LEN). The actual size is computed by increasing this number by one. A value of zero means one write block, 127 means 128 write blocks.
MMC: ERASE_GRP_SIZE
The contents of this register is a 5 bit binary coded value, used to calculate the size of the erasable unit of the moviNAND. The size of the erase unit (also referred to as erase group) is determined by the ERASE_GRP_SIZE and the ERASE_GRP_MULT entries of the CSD, using the following equation:

      size of erasable unit = (ERASE_GRP_SIZE + 1) * (ERASE_GRP_MULT + 1)

This size is given as minimum number of write blocks that can be erased in a single erase command.
MMC: ERASE_GRP_MULT
A 5 bit binary coded value used for calculating the size of the erasable unit of the moviNAND. See ERASE_GRP_SIZE section for detailed description.
MMC: DEFAULT_ECC
Set by the moviNAND manufacturer. It defines the ECC code which is recommended for use. The field definition is the same as for the ECC field described later.
MMC: CONTENT_PROT_APP
This field in the CSD indicates whether the content protection application is supported. MultiMediaCards which implement the content protection application will have this bit set to '1'.
MMC: ECC
Defines the ECC code that was used for storing data on the moviNAND. This field is used by the host (or application) to decode the user data. The following table defines the field format:

      ECC      ECC type         Maximum number of correctable bits per block
      00h      None (default)   Mone
      01h      BCH (542,512)    3
      02h-03h  Reserved         -

MMC: WP_GRP_SIZE (5bit)
The size of a write protected group. The contents of this register is a 5 bit binary coded value, defining the number of erase groups which can be write protected.
The actual size is computed by increasing this number by one. A value of zero means 1 erase group, 31 means 32 erase groups. (Refer to the chapter 4.11.1 on page 48)
SD: WP_GRP_SIZE (7bit)
The size of a write protected group. The content of this register is a 7-bit binary coded value, defining the number of erase sectors (see SECTOR_SIZE). The actual size is computed by increasing this number by one. A value of zero means one erase sector, 127 means 128 erase sectors.
WP_GRP_ENABLE
A value of 0 means no group write protection possible.
R2W_FACTOR
Defines the typical block program time as a multiple of the read access time.

      2-0   Multiples of read access time (0..5=Mul 1,2,4,8,16,32, 6..7=Reserved)

For example, value 5 means that writing is 32 times slower than reading.
WRITE_BL_LEN
The maximum write data block length is computed as 2^WRITE_BL_LEN. The maximum block length might therefore be in the range from 512 to 2048 bytes. Write Block Length of 512 bytes is always supported.
Note that in the SD Memory Card, the WRITE_BL_LEN is always equal to READ_BL_LEN.

      3-0    Block Length

Values:

      00h..08h  Reserved
      09h       512 bytes (2^9)
      0Ah       1024 Bytes (2^10)
      0Bh       2048 Bytes (2^11)
      0Ch..0Fh  Reserved

MMC: See READ_BL_LEN
WRITE_BL_PARTIAL
Defines whether partial block sizes can be used in block write commands.
WRITE_BL_PARTIAL=0 means that only the WRITE_BL_LEN block size and its partial derivatives, in resolution of units of 512 bytes, can be used for block oriented data write.
WRITE_BL_PARTIAL=1 means that smaller blocks can be used as well. The minimum block size is one byte.
COPY
Defines whether the contents is original (=0) or has been copied (=1). Setting this bit to 1 indicates that the card content is a copy. The COPY bit is a one time programmable bit except ROM card.
PERM_WRITE_PROTECT
TMP_WRITE_PROTECT
Permanently/temporarily write-protects the entire card (by disabling all write and erase commands). The default values are 0, ie. not write protected.
FILE_FORMAT
FILE_FORMAT_GRP
Indicates the file format on the card. These fields are read-only for ROM. The following formats are defined:

      FILE_FORMAT_GRP  FILE_FORMAT  Type
      0                0            Hard disk-like file system with partition table
      0                1            DOS FAT (floppy-like) with boot sector only
                                      (no partition table)
      0                2            Universal File Format
      0                3            Others/Unknown
      1                0, 1, 2, 3   Reserved

A more detailed description is given in the Filesystem Specification.

DSi SD/MMC Protocol: CSD Register (128bit Card-Specific Data) Version 2.0

CSD Register (CSD Version 2.0) (SDHC/SDXC)
The field name in parenthesis is set to fixed value and indicates that the host is not necessary to refer these fields. The fixed values enables host, which refers to these fields, to keep compatibility to CSD Version 1.0.
The Cell Type field is coded as follows: R=readable, W(1)=writable once, W=multiple writable.

      Bit   Siz Type   Name                        Field          Value
      127-126 2 R      CSD structure               CSD_STRUCTURE  01b
      125-120 6 R      reserved                    -              000000b
      119-112 8 R      data read access-time-1     (TAAC)         0Eh
      111-104 8 R      data read access-time-2     (NSAC)         00h
      103-96  8 R      max data transfer rate      (TRAN_SPEED)   32h,5Ah,0Bh,2Bh
      95-84  12 R      card command classes        CCC            x1x110110101b
      83-80   4 R      max read data block length       (READ_BL_LEN)        9
      79      1 R      partial blocks for read allowed  (READ_BL_PARTIAL)    0
      78      1 R      write block misalignment         (WRITE_BLK_MISALIGN) 0
      77      1 R      read block misalignment          (READ_BLK_MISALIGN)  0
      76      1 R      DSR implemented                  DSR_IMP              x
      75-70   6 R      reserved                         -                   000000b
      69-48  22 R      device size                      C_SIZE              xxxxxxh
      47      1 R      reserved                         -                    0
      46      1 R      erase single block enable        (ERASE_BLK_EN)       1
      45-39   7 R      erase sector size                (SECTOR_SIZE)        7Fh
      38-32   7 R      write protect group size         (WP_GRP_SIZE)        00h
      31      1 R      write protect group enable       (WP_GRP_ENABLE)      0
      30-29   2 R      reserved                         -                    00b
      28-26   3 R      write speed factor               (R2W_FACTOR)         010b
      25-22   4 R      max write data block length      (WRITE_BL_LEN)       9
      21      1 R      partial blocks for write allowed (WRITE_BL_PARTIAL)   0
      20-16   5 R      reserved                         -                    00000b
      15      1 R      File format group                (FILE_FORMAT_GRP)    0
      14      1 R/W(1) copy flag                        COPY                 x
      13      1 R/W(1) permanent write protection       PERM_WRITE_PROTECT   x
      12      1 R/W    temporary write protection       TMP_WRITE_PROTECT    x
      11-10   2 R      File format                      (FILE_FORMAT)        00b
      9-8     2 R      reserved                         -                    00b
      7-1     7 R/W    CRC                              CRC                  xxh
      0       1 -      not used, always '1'             -                    1

C_SIZE
This field is expanded to 22 bits and can indicate up to 2 TBytes (that is the same as the maximum memory space specified by a 32-bit block address.)
This parameter is used to calculate the user data area capacity in the SD memory card (not include the protected area). The user data area capacity is calculated from C_SIZE as follows:

      memory capacity = (C_SIZE+1) * 512KByte

The Minimum user area size of SDHC Card is 4,211,712 sectors (2GB + 8.5MB).
The Minimum value of C_SIZE for SDHC in CSD Version 2.0 is 001010h (4112).
The Maximum user area size of SDHC Card is (32GB - 80MB).
The Maximum value of C_SIZE for SDHC in CSD Version 2.0 is 00FF5Fh (65375).
The Minimum user area size of SDXC Card is 67,108,864 sectors (32GB).
The Minimum value of C_SIZE for SDXC in CSD Version 2.0 is 00FFFFh (65535).
TRAN_SPEED
TRAN_SPEED is variable depends on bus speed mode of SD Interface.
When CMD0 is received, this field is reset to 32h.
On SDSC (but not SDHC/SDXC), CMD6 does the same reset stuff?

      32h   SDSC/SDHC/SDXC in Default Speed mode (25MHz)
      5Ah   SDSC/SDHC/SDXC in High Speed mode    (50MHz)
      0Bh   SDHC/SDXC in SDR50 or DDR50 mode     (100Mbit/sec)
      2Bh   SDHC/SDXC in SDR104 mode             (200Mbit/sec)

UHS-II mode is not related to this field.
CCC, DSR_IMP, COPY, PERM_WRITE_PROTECT, TMP_WRITE_PROTECT
Definition of these fields is same as in CSD Version 1.0.
TAAC, NSAC, R2W_FACTOR
In SDHC/SDXC, these fields should be fixed to TAAC=0Eh (1 ms), NSAC=00h, and R2W_FACTOR=02h (mul4).
The host should not use TAAC, NSAC, and R2W_FACTOR to calculate timeout and should uses fixed timeout values for read and write operations (See 4.6.2).
READ_BL_LEN, WRITE_BL_LEN
These two fields are fixed to 9h (which indicates 512 Bytes).
READ_BL_PARTIAL, WRITE_BL_PARTIAL, READ_BLK_MISALIGN, WRITE_BLK_MISALIGN
These four fields are fixed to 0 (partial block read and physical page crossing prohibited for block read/write).
SECTOR_SIZE
This field is fixed to 7Fh, which indicates 64 KBytes. This value is not related to erase operation. SDHC and SDXC Cards indicate memory boundary by AU size and this field should not be used.
ERASE_BLK_EN
This field is fixed to 1, which means the host can erase one or multiple units of 512 bytes.
WP_GRP_SIZE, WP_GRP_ENABLE
These field are fixed to WP_GRP_SIZE=00h, and WP_GRP_ENABLE=0.
SDHC and SDXC Cards do not support write protected groups.
FILE_FORMAT_GRP
FILE_FORMAT
These fields are set to 0. Host should not use these fields.

DSi SD/MMC Protocol: EXT_CSD Register (4096bit Extended CSD Register) (MMC)

CMD8 - MMC - SPI - GET_EXT_CSD (type=adtc)

      31-0  stuff bits

Response: R1
Additional Data Transfer (from card):

      4095-0  EXT_CSD Register (4096bit)

MMC only.
CMD6 - MMC - SPI - SWITCH (type=ac)

      31-26  6bit  Reserved (0)
      25-24  2bit  Access
                     00h  Change Command Set (EXT_CSD[191] = parameter bit2-0)
                     01h  Set bits (EXT_CSD[index] = EXT_CSD[index] OR value)
                     02h  Clr bits (EXT_CSD[index] = EXT_CSD[index] AND NOT value)
                     03h  Write    (EXT_CSD[index] = value)
      23-16  8bit  Index (0..191)   ;\used only if "Access=1..3"
      15-8   8bit  Value (0..255)   ;/
      7-3    5bit  Reserved (0)
      2-0    3bit  Cmd Set (0..7)   ;-used only if "Access=0"

Response: R1b
Additional Data Transfer (from card): Busy signal for "R1b" response
MMC only.
Extended CSD Register (MMC only)
The Extended CSD register defines the card properties and selected modes. It is 512 bytes (4096 bits) long.
The most significant 320 bytes are the Properties segment, which defines the card capabilities and cannot be modified by the host. The lower 192 bytes are the Modes segment, which defines the configuration the card is working in. These modes can be changed by the host by means of the SWITCH command.

      Properties Segment
      Byte    Siz  Type  Name                                  Field
      511-505   7  -     Reserved(1)                           -
      504       1  R     Supported Command Sets                S_CMD_SET
      503-216 288  -     Reserved(1)                           -
      215-212   4  R     moviNAND only: Sector Count           SEC_COUNT
      211       1  -     Reserved                              -
      210       1  R     Min Write Performance for 8bit @52MHz MIN_PERF_W_8_52
      209       1  R     Min Read Performance for 8bit @52MHz  MIN_PERF_R_8_52
      208       1  R     Min Write Perf. for 8/4bit @26/52MHz  MIN_PERF_W_8_26_4_52
      207       1  R     Min Read Perf. for 8/4bit @26/52MHz   MIN_PERF_R_8_26_4_52
      206       1  R     Min Write Performance for 4bit @26MHz MIN_PERF_W_4_26
      205       1  R     Min Read Performance for 4bit @26MHz  MIN_PERF_R_4_26
      204       1  -     Reserved(1)                           -
      203       1  R     Power Class for 26MHz @ 3.6V          PWR_CL_26_360
      202       1  R     Power Class for 52MHz @ 3.6V          PWR_CL_52_360
      201       1  R     Power Class for 26MHz @ 1.95V         PWR_CL_26_195
      200       1  R     Power Class for 52MHz @ 1.95V         PWR_CL_52_195
      199-197   3  -     Reserved(1)                           -
      196       1  R     Card Type                             CARD_TYPE
      195       1  -     Reserved(1)                           -
      194       1  R     CSD Structure Version                 CSD_STRUCTURE
      193       1  -     Reserved(1)                           -
      192 C0h   1  R     Extended CSD Revision                 EXT_CSD_REV
      Modes Segment
      191 BFh   1  R/W   Command Set                           CMD_SET
      190 BEh   1  -     Reserved(1)                           -
      189 BDh   1  RO    Command Set Revision                  CMD_SET_REV
      188 BCh   1  -     Reserved(1)                           -
      187 BBh   1  R/W   Power Class                           POWER_CLASS
      186 BAh   1  -     Reserved(1)                           -
      185 B9h   1  R/W   High Speed Interface Timing           HS_TIMING
      184 B8h   1  -     Reserved(1)                           -
      183 B7h   1  WO    Bus Width Mode                        BUS_WIDTH
      182 B6h      ?     ?
      181 B5h   1  -     Reserved                              -
      180 B4h   1  RO    moviNAND only: Erased Memory Content  ERASED_MEM_CONT
      180-0   181  -     Reserved(a)                           -

(a) Reserved(a) bits should read as '0'.
(1) Reserved(1) bits should be probably ZERO, too.
The above table is transferred "most significant first", which does probably mean that it starts with BYTE 0, not with byte 511. ALTHOUGH, the 4-byte SEC_COUNT appears to be LITTLE-ENDIAN?
Note: JEDEC Standard No. 84-A44 contains MANY additional fields in EXT_CSD.
S_CMD_SET
This field defines which command sets are supported by the card.

      Bit   Command Set
      7-5   Reserved
      4     moviNAND only: ATA on MMC
      3     moviNAND only: SecureMCC 2.0
      2     Content Protection SecureMMC
      1     SecureMMC
      0     Standard MMC

SEC_COUNT (moviNAND and newer JEDEC specs only)
The device density is calculated from the register by multiplying the value of the register (sector count) by 512B/sector. The maximum density possible to be indicated is thus 2 Tera bytes (minus 512 bytes) (4,294,967,295 x 512B). The least significant byte (LSB) of the sector count value is the byte [212].
MIN_PERF_a_b_ff
These fields defines the overall minimum performance value for the read and write access with different bus width and max clock frequency modes. The value in the register is coded as follows. Other than defined values are illegal.

      Value Performance
      0x00  For Cards not reaching the 2.4MB/s minimum value
      0x08  Class A: 2.4MB/s and is the lowest allowed value for MMCplus and
             MMCmobile(16x150kB/s)
      0x0A  Class B: 3.0MB/s and is the next allowed value (20x150kB/s)
      0x0F  Class C: 4.5MB/s and is the next allowed value (30x150kB/s)
      0x14  Class D: 6.0MB/s and is the next allowed value (40x150kB/s)
      0x1E  Class E: 9.0MB/s and is the next allowed value (60x150kB/s)
             This is also the highest class which any MMCplus or MMCmobile card
             is needed to support in low bus category operation mode (26MHz with
             4bit data bus).
             A MMCplus or MMCmobile card supporting any higher class than this
             have to support this class also (in low category bus operation mode).
      0x28  Class F: Equals 12.0MB/s and is the next allowed value (80x150kB/s)
      0x32  Class G: Equals 15.0MB/s and is the next allowed value (100x150kB/s)
      0x3C  Class H: Equals 18.0MB/s and is the next allowed value (120x150kB/s)
      0x46  Class J: Equals 21.0MB/s and is the next allowed value (140x150kB/s)
             This is also the highest class which any MMCplus or MMCmobile card
             is needed to support in mid bus category operation mode (26MHz with
             8bit data bus or 52MHz with 4bit data bus).
             A MMCplus or MMCmobile card supporting any higher class than this
             have to support this Class (in mid category bus operation mode) and
             Class E also (in low category bus operation mode).
      0x50  Class K: Equals 24.0MB/s and is the next allowed value (160x150kB/s)
      0x64  Class M: Equals 30.0MB/s and is the next allowed value (200x150kB/s)
      0x78  Class O: Equals 36.0MB/s and is the next allowed value (240x150kB/s)
      0x8C  Class R: Equals 42.0MB/s and is the next allowed value (280x150kB/s)
      0xA0  Class T: Equals 48.0MB/s and is the last defined value (320x150kB/s)

PWR_CL_ff_vvv
These fields define the supported power classes by the card. By default, the card has to operate at maximum frequency using 1 bit bus configuration, within the default max current consumption, as stated in the table below. If 4 bit/8 bits bus configurations, require increased current consumption, it has to be stated in these registers.
By reading these registers the host can determine the power consumption of the card in different bus modes. Bits [7:4] code the current consumption for the 8 bit bus configuration. Bits [3:0] code the current consumption for the 4 bit bus configuration.
The PWR_52_vvv registers are not defined for 26MHz MultiMediaCards.

      Voltage Value Max RMS Current   Max Peak Current   Remarks
      3.6V    0     100 mA            200 mA             Default current
              1     120 mA            220 mA             consumption for
              2     150 mA            250 mA             high voltage cards
              3     180 mA            280 mA
              4     200 mA            300 mA
              5     220 mA            320 mA
              6     250 mA            350 mA
              7     300 mA            400 mA
              8     350 mA            450 mA
              9     400 mA            500 mA
              10    450 mA            550 mA
              11-15 Reserved for future use
      1.95V   0     65 mA             130 mA             Default current
              1     70 mA             140 mA             consumption for
              2     80 mA             160 mA             Dual voltage cards
              3     90 mA             180 mA             (if any, not moviNAND)
              4     100 mA            200 mA
              5     120 mA            220 mA
              6     140 mA            240 mA
              7     160 mA            260 mA
              8     180 mA            280 mA
              9     200 mA            300 mA
              10    250 mA            350 mA
              6-15  Reserved for future use

The measurement for max RMS current is done as average RMS current consumption over a period of 100ms.
Max peak current is defined as absolute max value not to be exceeded at all.
The conditions under which the power classes are defined are:

      - Maximum bus frequency
      - Maximum operating voltage
      - Worst case functional operation
      - Worst case environmental parameters (temperature,...)

These registers define the maximum power consumption for any protocol operation in data transfer mode, Ready state and Identification state.
CARD_TYPE
This field defines the type of the card. The only currently valid values for this field are 0x01 and 0x03.

      Bit Card Type
      7-2 Reserved
      1   High Speed MultiMediaCard @ 52MHz
      0   High Speed MultiMediaCard @ 26MHz

CSD_STRUCTURE
This field is a continuation of the CSD_STRUCTURE field in the CSD register.

      CSD_STRUCTURE CSD structure version   Valid for System Specification Version
      0             CSD version No. 1.0     Version 1.0 - 1.2
      1             CSD version No. 1.1     Version 1.4 - 2.2
      2             CSD version No. 1.2     Version 3.1-3.2-3.31-4.0-4.1-4.2
      3             Reserved for future use
      4-255         Reserved for future use

EXT_CSD_REV
Defines the fixed parameters. related to the EXT_CSD, according to its revision.

      EXT_CSD_REV   Extended CSD Revision
      0             Revision 1.0
      1             Revision 1.1
      2             Revision 1.2 (moviNAND)
      3-255         Reserved

CMD_SET
Contains the binary code of the command set that is currently active in the card. It is set to '0' (Standard MMC) after power up and can be changed by a SWITCH command.
CMD_SET_REV
Contains a binary number reflecting the revision of the currently active command set. For Standard MMC command set it is:

      Code    MMC Revisions
      0       v4.0
      1-255   Reserved

This field, though in the Modes segment of the EXT_CSD, is read only.
POWER_CLASS
This field contains the 4 bit value of the selected power class for the card. The power classes are defined in Table. The host should be responsible of properly writing this field with the maximum power class it allows the card to use. The card uses this information to, internally, manage the power budget and deliver an optimized performance.
This field is 0 after power-on or software reset.

      Bits    Description
      7-4     Reserved
      3-0     Card power class code (See Table 5-29)

HS_TIMING
This field is 0 after power-on, or software reset, thus selecting the backwards compatibility interface timing for the card. If the host writes 1 to this field, the card changes its timing to high speed interface timing (refer to Chapter 5.4.8).
BUS_WIDTH
It is set to '0' (1 bit data bus) after power up and can be changed by a SWITCH command.

      Value   Bus Mode
      0       1 bit data bus (MMC, with old 7pin connector)
      1       4 bit data bus (MMCplus, with SD-card-compatible 9pin connector)
      2       8 bit data bus (MMCplus, with special 13pin connector)
      3-255   Reserved

For detecting cards with 4bit/8bit data bus support: Switch the SD/MMC controller to 4bit/8bit modes, and use BUSTEST_W and BUSTEST_R to test if the card sends a proper response, see https://www.mikrocontroller.net/attachment/101561/AN_MMCA050419.pdf
Note: The SD/MMC controller in the DSi supports 1bit/4bit modes only (no 8bit mode). For the DSi's onboard eMMC it's safe to assume 4bit being supported, however, external MMC cards do require detecting 4bit support.
ERASED_MEM_CONT (moviNAND) (but, RESERVED in newer JEDEC specs!)
This Field defines the content of an explicitly erased memory range.

      Value   Erased Memory content
      00h     Erased memory range shall be '0'
      01h     Erased memory range shall be '1'
      02h-FFh Reserved

Looks like a mis-definition, since value 00h should have been kept reserved for cards that do not specify whether they set erased bits to 0 or 1.

DSi SD/MMC Protocol: RCA Register (16bit Relative Card Address)

The RCA was intended for connecting multiple cards to the same host, possibly even sharing the same signal wires for multiple cards. The multi-card feature isn't used to often though.
Most hosts are having only a single card slot. And, hosts that <do> support multiple cards may use separate busses and even separate controllers for each card (eg. Nintendo DSi is doing so for onboard NAND and external SD slot).
However, even single-card systems will need to obtain a "dummy" RCA, and use that RCA value for selecting the card.
The only exception is SPI mode: SPI isn't using RCA, and doesn't support RCA commands at all - instead, in SPI mode, the cards are selected via /CS signal (which may include multiple /CS signals for multiple cards).
CMD3 - SD - GET_RELATIVE_ADDR (type=bcr)
Parameter bits:

      31-0  stuff bits

Response: R6:

      47      Start Bit (0)                                 ;\
      46      Transmission To Host (0)                      ; 1st byte
      45-40   Command (the 6bit CMD being responded to)     ;/
      39-24   New published RCA of the card   ;-16bit       ;-2nd..3th byte
      23-22   CSR Card Status, bit 23-22      ;\            ;\
      21      CSR Card Status, bit 19         ; 16bit       ; 4nd..5th byte
      20-8    CSR Card Status, bit 12-0       ;/            ;/
      7-1     CRC7                                          ;\6th byte
      0       End Bit (1)                                   ;/

Ask the card to publish a new relative address (RCA).
Dunno how this is intended to work with multiple cards. The goal should be to assign <different> RCAs to each card. The command should be probably repeatedly used until all cards respond with different RCAs. This would require the cards to contain some sort of analog random generator - or maybe to use the CID register as random seed (the CID seems to contain unique serial numbers per card)?
CMD3 - MMC - SET_RELATIVE_ADDR (type=ac)
Parameter bits:

      31-16 RCA
      15-0  stuff bits

Response: R1
Assigns an RCA value TO the card (ie. the opposite of CMD3 on SD Cards).
Dunno how this is intended to work with multiple cards. The goal should be to assign <different> RCAs to each card. But actually, the command appears to assign the <same> RCA to all cards?
CMD7 - SD/MMC - SELECT_DESELECT_CARD (type=ac) ;actually: (type=bcr)
Parameter bits:

      31-16 RCA
      15-0  stuff bits

Response: R1b (only from the selected card)
Additional Data Transfer (from card): Busy signal for "R1b" response
Command toggles a card between the stand-by and transfer states or between the programming and disconnect states. In both cases, the card is selected by its own relative address and gets deselected by any other address; address 0 deselects all.
In the case that the RCA equals 0, then the host may do one of the following:
- Use other RCA number to perform card de-selection.
- Re-send CMD3 to change its RCA number to other than 0 and then use CMD7 with RCA=0 for card deselection.
CMD5 - MMC - SLEEP_AWAKE (type=ac)
Parameter bits:

      31-16 RCA
      15    Sleep/Awake flag (0=Awake/stby, 1=Sleep/slp)
      14-0  stuff bits

Response: R1b
RCA register
The writable 16-bit relative card address register carries the card address that is published by the card during the card identification. This address is used for the addressed host-card communication after the card identification procedure. The default value of the RCA register is 0000h. The value 0000h is reserved to set all cards into the Stand-by State with CMD7.
In UHS-II mode, Node ID is used as RCA. Refer to SD-TRAN Section of UHS-II Addendum for more details.
Note
Commands GET_CSD, GET_CID, APP_CMD, GO_INACTIVE_STATE, and GET_STATUS allow/require to specify RCA in parameter field.
Other commands are either processed by all cards (broadcast commands), or processed only be cards that have been previously selected via CMD7 (most normal commands).
Broadcast Commands

      CMD0     sd/mmc spi GO_IDLE_STATE (type=bc)
      CMD2     sd/mmc     ALL_GET_CID (type=bcr)
      CMD3     sd         GET_RELATIVE_ADDR (type=bcr)
      CMD4     sd/mmc     SET_DSR (type=bc)
      CMD7     sd/mmc     SELECT_DESELECT_CARD (type=ac) ;actually: (type=bcr)
      CMD8     sd     spi SET_IF_COND (type=bcr)
      ACMD41   sd     spi SD_SEND_OP_COND (type=bcr)  ;SPI: reduced functionality

Some broadcast commands are sending responses.
SD specs are suggesting to use separate CMD lines for each card (so the host would broadcast the same command on all CMD lines, and would receive separate responses in parallel from each CMD line).
MMC cards are said to support open-collector CMD lines (so responses from separate cards would be logically ORed, though, dunno what that would be good for).

DSi SD/MMC Protocol: DSR Register (16bit Driver Stage Register) (Optional)

CMD4 - SD/MMC - SET_DSR (type=bc)
Parameter bits:

      31-16 DSR
      15-0  stuff bits

Response: N/A
Programs the DSR of all cards.
DSR register (Optional)
The 16-bit driver stage register is described in detail in Chapter 0 (uh, where?). It can be optionally used to improve the bus performance for extended operating conditions (depending on parameters like bus length, transfer rate or number of cards). The CSD register carries the information about the DSR register usage. The default value of the DSR register is 0404h.

DSi SD/MMC Protocol: SCR Register (64bit SD Card Configuration Register)

ACMD51 - SD - SPI - GET_SCR (type=adtc)

      31-0  stuff bits

Response: R1
Additional Data Transfer (from card):

      63-0  SCR Register (8bytes, aka 64bit)

SD Configuration Register (SCR)
In addition to the CSD register, there is another configuration register named SD CARD Configuration Register (SCR). SCR provides information on the SD Memory Card's special features that were configured into the given card. The size of SCR register is 64 bits. This register shall be set in the factory by the SD Memory Card manufacturer.

      Bit  Siz  Typ Description                      Field                 ;common
      63-60  4  R   SCR Structure                    SCR_STRUCTURE         ;\00h or
      59-56  4  R   SD Memory Card - Spec. Version   SD_SPEC               ;/01h
      55     1  R   data_status_after erases         DATA_STAT_AFTER_ERASE ;\
      54-52  3  R   CPRM Security Support            SD_SECURITY           ; A5h
      51-48  4  R   DAT Bus widths supported         SD_BUS_WIDTHS         ;/
      47     1  R   Spec. Version 3.00 or higher     SD_SPEC3              ;\
      46-43  4  R   Extended Security Support        EX_SECURITY           ; 0000h
      42     1  R   Spec. Version 4.00 or higher     SD_SPEC4              ;
      41-36  6  R   Reserved                         -                     ;
      35-32  4  R   Command Support bits             CMD_SUPPORT           ;/
      31-0  32  R   reserved for manufacturer usage  -                     ;-var

SCR Register Structure Version

      SCR_STRUCTURE  SCR Structure Version  SD Physical Layer Specification Version
      00h            SCR version 1.0        Version 1.01-4.00
      01h..0Fh       reserved

Note: SD_SPEC is used to indicate SCR Structure Version instead of this field.
SD_SPEC, SD_SPEC3, SD_SPEC4
The Physical Layer Specification Version is indicated in combination with SD_SPEC, SD_SPEC3 and SD_SPEC4 as described Table 5-19.

      SD_SPEC  SD_SPEC3  SD_SPEC4   Physical Layer Specification Version Number
      0        0         0          Version 1.0 and 1.01
      1        0         0          Version 1.10
      2        0         0          Version 2.00
      2        1         0          Version 3.0X
      2        1         1          Version 4.XX
             Others                 Reserved

(1) Version 2.00 hosts do not recognize SD_SPEC3 and SD_SPEC4.
(2) Version 3.00 hosts do not recognize SD_SPEC4.
Hosts recognize Physical Layer Specification Version shall also recognize including future version. Next version will be defined in SD_SPEC field.
The card manufacturer determines SD_SPEC value by conditions indicated below. All conditions shall be satisfied for each version. The other combination of conditions is not allowed.
Essential conditions to indicate Version 1.01 Card (SD_SPEC=0, SD_SPEC3=0 and SD_SPEC4=0):

      (1) The card does not support CMD6
      (2) The card does not support CMD8
      (3) User area capacity shall be up to 2GB

Essential conditions to indicate Version 1.10 Card (SD_SPEC=1, SD_SPEC3=0 and SD_SPEC4=0):

      (1) The card shall support CMD6
      (2) The card does not support CMD8
      (3) User area capacity shall be up to 2GB

Essential conditions to indicate Version 2.00 Card (SD_SPEC=2, SD_SPEC3=0 and SD_SPEC4=0):

      (1) The card shall support CMD6
      (2) The card shall support CMD8
      (3) The card shall support CMD42
      (4) User area capacity shall be up to 2GB (SDSC) or 32GB (SDHC)
      (5) Speed Class shall be supported (SDHC)

Essential conditions to indicate Version 3.00 Card (SD_SPEC=2, SD_SPEC3=1 and SD_SPEC4=0):

      (1) The card shall support CMD6
      (2) The card shall support CMD8
      (3) The card shall support CMD42
      (4) User area capacity shall be up to 2GB (SDSC) or 32GB (SDHC)
        User area capacity shall be more than or equal to 32GB and up to 2TB (SDXC)
      (5) Speed Class shall be supported (SDHC or SDXC)

Optional conditions to indicate Version 3.00 Card:

      A card supports any of following functions shall satisfy essential
      conditions of Version 3.00 Card
      (1) Speed Class supported under the conditions defined in Version 3.00
      (2) UHS-I supported card
      (3) CMD23 supported card

Essential conditions to indicate Version 4.XX Card (SD_SPEC=2, SD_SPEC3=1 and SD_SPEC4=1):

      (1) Same as the essential conditions of Version 3.00 device
      (2) Support any of additional functions defined by Version 4.XX:
          Followings functions (a) to (c) are defined by Version 4.00.
            (a) Support of CMD48 and CMD49
            (b) Support of UHS-II mode
            (c) Support of DPS (Data Protection System)
          Followings functions (d) to (f) are defined by Version 4.10.
            (d) Support of CMD58 and CMD59
            (e) Support of Power Management Functions
            (f) Support of Speed Grade 1 for UHS-II mode

The requirements of supporting commands mentioned above are for the optional commands, the support of which depends on versions (SD_SPEC, SD_SPEC3 and SD_SPEC4). Refer to Table 4-21 (and Notes below the table) about the mandatory and optional commands in the card.
DATA_STAT_AFTER_ERASE
Defines the data status after erase, whether it is 0 or 1 (the status is card vendor dependent).
SD_SECURITY
This field indicates CPRM Security Specification Version for each capacity card. The definition of Protected Area is different in each capacity card.

      00h           No Security
      01h           Not Used
      02h           SDSC Card (CPRM Security Version 1.01)
      03h           SDHC Card (CPRM Security Version 2.00)
      04h           SDXC Card (CPRM Security Version 3.xx)
      05h-07h       Reserved

The basic rule of setting this field:

      SDSC Card sets this field to 2 (Version 1.01).
      SDHC Card sets this field to 3 (Version 2.00).
      SDXC Card sets this field to 4 (Version 3.xx).

Note that it is mandatory for a regular writable SD Memory Card to support Security Protocol. For ROM (Read Only) and OTP (One Time Programmable) types of the SD Memory Card, the security feature is optional.
SD_BUS_WIDTHS
Describes all the DAT bus widths that are supported by this card.

      Bit 3          Reserved
      Bit 2          4 bit (DAT0-3)
      Bit 1          Reserved
      Bit 0          1 bit (DAT0)

Since the SD Memory Card shall support at least the two bus modes 1-bit or 4-bit width, then any SD Card shall set at least bits 0 and 2 (SD_BUS_WIDTH="0101").
EX_SECURITY
This field indicates Extended Security which is defined by the Part A4 Data Protection System Specification Version 1.00 or will be defined by a later version of the Part 3 Security Specification Version 3.00.

      00h          Extended Security is not supported.
      01h..0Fh     Extended Security is supported. SCR[44-43] is defined by the
                     Part A4 Data Protection System Specification. SCR[46-45] is
                     reserved for future extension.

CMD_SUPPORT
Support bit of new commands are defined to Bit 33-32 (uh, 35-32?) of SCR.

      Bit Supported Command               Command  CCC  Remark
      35  Extension Register Multi-Block  CMD58/59 11   Optional.
      34  Extension Register Single Block CMD48/49 11   Optional.
      33  Set Block Count                 CMD23    2,4  Mandatory for UHS104 card
      32  Speed Class Control             CMD20    2,4  Mandatory for SDXC card

If CMD58/59 is supported, then CMD48/49 shall be also supported.

DSi SD/MMC Protocol: PWD Register (128bit Password plus 8bit Password len)

CMD40 - SD - Defined by DPS Spec (Data Protection System) (type=adtc)

      Defined by DPS Spec.

Response: R1
Additional Data Transfer (to/from whatever):

      unknown

Single block read type. Intended to read whatever "public" data, which is available even if the card is locked.
CMD42 - SD/MMC (SD v2.00 and up) - SPI - LOCK_UNLOCK (type=adtc)

      31-0  Reserved bits (0)

Response: R1 (MMC: R1b?)
MMC?: Additional Data Transfer (from card): Busy signal for "R1b" response
Additional Data Transfer (to card):

      Note: Before using this command, the size of the following data block (ie.
            "1st..Nth/Extra" byte) must be set via SET_BLOCKLEN command (CMD16).
      1st byte: Flags
        Bit7-4 Reserved (0)
        Bit3   ERASE       Force Erase (1=Erase WHOLE CARD and clear password)
        Bit1   LOCK_UNLOCK Lock card (0=Unlock, 1=Lock) (default on power up: Lock)
        Bit1   CLR_PWD     Clears password  (0=no, 1=yes)
        Bit0   SET_PWD     Set new password (0=no, 1=yes)
      2nd byte: PWDS_LEN   Length of the Password(s) in bytes ("3rd..Nth" byte)
      3rd..Nth byte: Password (old password, if SET_PWD: followed by new password)
      Extra byte: Alignment padding (only in DDR50 mode, if above is odd num bytes)

Used to set/clear the password (=to change the password), or to lock/unlock the card (=to log out/log in). If the password exists, then the default state on power-up is Locked (user is logged out).
In locked state, the card will accept only "Basic Commands" (class 0), plus CMD16,40,42, plus ACMD41,42. Observe that this will prevent some initialization commands (for example, switching to 4bit bus via SET_BUS_WIDTH (ACMD6) isn't possible on locked cards).
The password is stored in a 128bit PWD register, so password can be max 16 bytes long. The PWDS_LEN value can be max 32 bytes (when sending old+new password). The length of the current/old password is stored in an 8bit PWD_LEN register (though due to the above limit, that "8bit" value can be in range 0..16 only; PWD_LEN=0 means that there is no password, which is somewhat equivalent to what happens when setting the CLR_PWD bit?).
PWD Notes:
Related CSR status bits are: CARD_IS_LOCKED and LOCK_UNLOCK_FAILED. Presence of the locking feature is indicated by the CCC "class 7" bit in CSD register.
Many SD cards are internally containing separate controller and memory chips, so it might be quite easy to bypass the locking by desoldering one of those chips.

DSi SD/MMC Protocol: State

SD/MMC State
The "state" is an important SD/MMC feature to deal with - most commands can be send only in certain states:
For normal operation, the card should be in "tran" state (and it may then temporarily switch to "data/rcv/prg" states during read/write/erase commands).
For initialization, the card should be first forced to "idle" state, and the init commands should then go through "ready/ident/stby" states, until finally reaching "tran" state.
Less important states are "dis/ina", and, on MMC only, "btst/slp/irq" and "pre-idle".
Both SD and MMC specs are leaving state undocumented for SPI mode (meaning that SPI specific commands like CMD58/CMD59 are supported only in "unknown" state).
SD Card State Transition Table

      Command       old state --> idle readyidentstby tran data rcv  prg  dis  ina
      DONE  Operation Complete    ---- ---- ---- ---- ---- tran ---- tran stby ----
      class 0
      CMD0  GO_IDLE_STATE         ok   idle idle idle idle idle idle idle idle ----
      CMD2  ALL_SEND_CID          ---- ident---- ---- ---- ---- ---- ---- ---- ----
      CMD3  SEND_RELATIVE_ADDR    ---- ---- stby ok   ---- ---- ---- ---- ---- ----
      CMD4  SET_DSR               ---- ---- ---- ok   ---- ---- ---- ---- ---- ----
      CMD7  SELECT_DESELECT_CARD
            card is addressed     ---- ---- ---- tran ---- ---- ---- ---- prg  ----
            card is not addr.     ---- ---- ---- ok   stby stby ---- dis  ---- ----
      CMD8  SEND_IF_COND          ok   ---- ---- ---- ---- ---- ---- ---- ---- ----
      CMD9  SEND_CSD              ---- ---- ---- ok   ---- ---- ---- ---- ---- ----
      CMD10 SEND_CID              ---- ---- ---- ok   ---- ---- ---- ---- ---- ----
      CMD11 VOLTAGE_SWITCH        ---- ok   ---- ---- ---- ---- ---- ---- ---- ----
      CMD12 STOP_TRANSMISSION     ---- ---- ---- ---- ---- tran prg  ---- ---- ----
      CMD13 SEND_STATUS           ---- ---- ---- ok   ok   ok   ok   ok   ok   ----
      CMD15 GO_INACTIVE_STATE     ---- ---- ---- ina  ina  ina  ina  ina  ina  ----
      class 2
      CMD16 SET_BLOCKLEN          ---- ---- ---- ---- ok   ---- ---- ---- ---- ----
      CMD17 READ_SINGLE_BLOCK     ---- ---- ---- ---- data ---- ---- ---- ---- ----
      CMD18 READ_MULTIPLE_BLOCK   ---- ---- ---- ---- data ---- ---- ---- ---- ----
      CMD19 SEND_TUNING_BLOCK     ---- ---- ---- ---- data ---- ---- ---- ---- ----
      CMD20 SPEED_CLASS_CONTROL   ---- ---- ---- ---- prg  ---- ---- ---- ---- ----
      CMD23                       ---- ---- ---- ---- ok   ---- ---- ---- ---- ----
      class 4
      CMD16 SET_BLOCKLEN       (2)---- ---- ---- ---- ok   ---- ---- ---- ---- ----
      CMD20 SPEED_CLASS_CONTROL(2)---- ---- ---- ---- prg  ---- ---- ---- ---- ----
      CMD23 SET_BLOCK_COUNT       ---- ---- ---- ---- ok   ---- ---- ---- ---- ----
      CMD24 WRITE_BLOCK           ---- ---- ---- ---- rcv  ---- ---- ---- ---- ----
      CMD25 WRITE_MULTIPLE_BLOCK  ---- ---- ---- ---- rcv  ---- ---- ---- ---- ----
      CMD27 PROGRAM_CSD           ---- ---- ---- ---- rcv  ---- ---- ---- ---- ----
      class 6
      CMD28 SET_WRITE_PROT        ---- ---- ---- ---- prg  ---- ---- ---- ---- ----
      CMD29 CLR_WRITE_PROT        ---- ---- ---- ---- prg  ---- ---- ---- ---- ----
      CMD30 SEND_WRITE_PROT       ---- ---- ---- ---- data ---- ---- ---- ---- ----
      class 5
      CMD32 ERASE_WR_BLK_START    ---- ---- ---- ---- ok   ---- ---- ---- ---- ----
      CMD33 ERASE_WR_BLK_END      ---- ---- ---- ---- ok   ---- ---- ---- ---- ----
      CMD38 ERASE                 ---- ---- ---- ---- prg  ---- ---- ---- ---- ----
      class 7
      CMD40 Read Block (DPS Spec) ---- ---- ---- ---- data ---- ---- ---- ---- ----
      CMD42 LOCK_UNLOCK           ---- ---- ---- ---- rcv  ---- ---- ---- ---- ----
      class 8
      CMD55 APP_CMD               ok   ---- ---- ok   ok   ok   ok   ok   ok   ----
      CMD56 GEN_CMD, RD/WR=0      ---- ---- ---- ---- rcv  ---- ---- ---- ---- ----
            GEN_CMD, RD/WR=1      ---- ---- ---- ---- data ---- ---- ---- ---- ----
      ACMD6  SET_BUS_WIDTH        ---- ---- ---- ---- ok   ---- ---- ---- ---- ----
      ACMD13 SD_STATUS            ---- ---- ---- ---- data ---- ---- ---- ---- ----
      ACMD22 SEND_NUM_WR_BLOCKS   ---- ---- ---- ---- data ---- ---- ---- ---- ----
      ACMD23 SET_WR_BLK_ERASE_CO. ---- ---- ---- ---- ok   ---- ---- ---- ---- ----
      ACMD41 SD_SEND_OP_COND
           OCR check is OK
           and card is not busy   ready---- ---- ---- ---- ---- ---- ---- ---- ----
           OCR check is OK
           and card is busy(2)    ok   ---- ---- ---- ---- ---- ---- ---- ---- ----
           OCR check fails
           query mode             ina  ---- ---- ---- ---- ---- ---- ---- ---- ----
      ACMD42 SET_CLR_CARD_DETECT  ---- ---- ---- ---- ok   ---- ---- ---- ---- ----
      ACMD51 SEND_SCR             ---- ---- ---- ---- data ---- ---- ---- ---- ----
      class 9
      class 10 (1)
      CMD6  SWITCH_FUNC           ---- ---- ---- ---- data ---- ---- ---- ---- ----
      class 11
      CMD48 READ_EXTR_SINGLE      ---- ---- ---- ---- data ---- ---- ---- ---- ----
      CMD49 WRITE_EXTR_SINGLE     ---- ---- ---- ---- rcv  ---- ---- ---- ---- ----
      CMD58 READ_EXTR_MULTI       ---- ---- ---- ---- data ---- ---- ---- ---- ----
      CMD59 WRITE_EXTR_MULTI      ---- ---- ---- ---- rcv  ---- ---- ---- ---- ----
      ACMD14-16               Refer to DPS Specification (class 8)
      ACMD28                  Refer to DPS Specification (class 8)
      ACMD18,25,26,38,
      43,44,45,46,47,48,49    Refer to the "Part3 Security Specification" for
                              information about the SD Security Features (class 8)
      CMD52-CMD54             Refer to the "SDIO Card Specification" (class 9)
      CMD21                   Refer to DPS Specification (class 11)
      CMD34-37,50,57          Refer to each command system specification (class 10)
      CMD41,CMD43-47          reserved (class 11)
      CMD60...CMD63           reserved for manufacturer (class 11)
      SPI Mode
      CMD1 SEND_OP_COND       SPI-only
      CMD58 READ_OCR          SPI-only
      CMD59 CRC_ON_OFF        SPI-only

Note (1): Class 10 commands were defined in Version 1.10.
Note (2): Card returns busy in case of following:

      - Card executes internal initialization process
      - When HCS in the argument is set to 0 to SDHC or SDXC Card.

The state transitions of the SD Memory Card application-specific commands are given under Class 8, above.

      ----  command is treated as illegal command
      ok    command is accepted, and card stays in SAME state
      xxx   command is accepted, and card switches to "xxx" state

MMC Card State Transition Table (JEDEC)

      Command     old state --> idl rdy idt stb trn dta tst rcv prg dis ina slp irq
      Class Independent
      ERR  CRC error            --- --- --- --- --- --- --- --- --- --- --- --- stb
      ERR  command not supported--- --- --- --- --- --- --- --- --- --- --- --- stb
      Class 0
      CMD0  (arg=00000000h)     ok  idl idl idl idl idl idl idl idl idl --- idl stb
            GO_IDLE_STATE
      CMD0  (arg=F0F0F0F0h)     pre pre pre pre pre pre pre pre pre pre --- pre stb
            GO_PRE_IDLE_STATE
      CMD0  (arg=FFFFFFFAh)     initiate alternative boot operation
            BOOT_INITIATION
      CMD1  SEND_OP_COND
            card VDD range ok   rdy --- --- --- --- --- --- --- --- --- --- --- stb
            card is busy        ok  --- --- --- --- --- --- --- --- --- --- --- stb
            card VDD range bad  ina --- --- --- --- --- --- --- --- --- --- --- stb
      CMD2  ALL_SEND_CID
             card wins bus      --- idt --- --- --- --- --- --- --- --- --- --- stb
             card loses bus     --- ok  --- --- --- --- --- --- --- --- --- --- stb
      CMD3  SET_RELATIVE_ADDR   --- --- stb --- --- --- --- --- --- --- --- --- stb
      CMD4  SET_DSR             --- --- --- ok  --- --- --- --- --- --- --- --- stb
      CMD5  SLEEP_AWAKE         --- --- --- slp -?- -?- -?- -?- -?- -?- -?- stb stb
      CMD6  SWITCH              --- --- --- --- prg --- --- --- --- --- --- --- stb
      CMD7  SELECT_DESELECT_CARD
            card is addressed   --- --- --- trn --- --- --- --- --- prg --- --- stb
            card is not addr.   --- --- --- --- stb stb --- --- dis --- --- --- stb
      CMD8  SEND_EXT_CSD        --- --- --- --- dta --- --- --- --- --- --- --- stb
      CMD9  SEND_CSD            --- --- --- ok  --- --- --- --- --- --- --- --- stb
      CMD10 SEND_CID            --- --- --- ok  --- --- --- --- --- --- --- --- stb
      CMD12 STOP_TRANSMISSION   --- --- --- --- --- trn --- prg --- --- --- --- stb
      CMD13 SEND_STATUS         --- --- --- ok  ok  ok  ok  ok  ok  ok  --- --- stb
      CMD14 BUSTEST_R           --- --- --- --- --- --- trn --- --- --- --- --- stb
      CMD15 GO_INACTIVE_STATE   --- --- --- ina ina ina ina ina ina ina --- --- stb
      CMD19 BUSTEST_W           --- --- --- --- tst --- --- --- --- --- --- --- stb
      Class 1
      CMD11 READ_DAT_UNTIL_STOP --- --- --- --- dta --- --- --- --- --- --- --- stb
      Class 2
      CMD16 SET_BLOCKLEN        --- --- --- --- ok  --- --- --- --- --- --- --- stb
      CMD17 READ_SINGLE_BLOCK   --- --- --- --- dta --- --- --- --- --- --- --- stb
      CMD18 READ_MULTIPLE_BLOCK --- --- --- --- dta --- --- --- --- --- --- --- stb
      CMD23 SET_BLOCK_COUNT     --- --- --- --- ok  --- --- --- --- --- --- --- stb
      Class 3
      CMD20 WRITE_DAT_UNTIL_STOP--- --- --- --- rcv --- --- --- --- --- --- --- stb
      Class 4
      CMD16 SET_BLOCKLEN        see class 2
      CMD23 SET_BLOCK_COUNT     see class 2
      CMD24 WRITE_BLOCK         --- --- --- --- rcv --- --- --- rcv1--- --- --- stb
      CMD25 WRITE_MULTIPLE_BL.  --- --- --- --- rcv --- --- --- rcv2--- --- --- stb
      CMD26 PROGRAM_CID         --- --- --- --- rcv --- --- --- --- --- --- --- stb
      CMD27 PROGRAM_CSD         --- --- --- --- rcv --- --- --- --- --- --- --- stb
      Class 6
      CMD28 SET_WRITE_PROT      --- --- --- --- prg --- --- --- --- --- --- --- stb
      CMD29 CLR_WRITE_PROT      --- --- --- --- prg --- --- --- --- --- --- --- stb
      CMD30 SEND_WRITE_PROT     --- --- --- --- dta --- --- --- --- --- --- --- stb
      CMD31 SEND_WRITE_PROT_TYPE--- --- --- --- dta --- --- --- --- --- --- --- stb
      Class 5
      CMD35 ERASE_GROUP_START   --- --- --- --- ok  --- --- --- --- --- --- --- stb
      CMD36 ERASE_GROUP_END     --- --- --- --- ok  --- --- --- --- --- --- --- stb
      CMD38 ERASE               --- --- --- --- prg --- --- --- --- --- --- --- stb
      Class 7
      CMD16 SET_BLOCKLEN        see class 2
      CMD42 LOCK_UNLOCK         --- --- --- --- rcv --- --- --- --- --- --- --- stb
      Class 8
      CMD55 APP_CMD             --- --- --- ok  ok  ok  ok  ok  ok  ok  --- --- ok
      CMD56 GEN_CMD, RD/WR=0    --- --- --- --- rcv --- --- --- --- --- --- --- stb
            GEN_CMD, RD/WR=1    --- --- --- --- dta --- --- --- --- --- --- --- stb
      Class 9
      CMD39 FAST_IO             --- --- --- ok  --- --- --- --- --- --- --- --- stb
      CMD40 GO_IRQ_STATE        --- --- --- irq --- --- --- --- --- --- --- --- stb
      Class 10-11
      CMD41, CMD43..CMD54       Reserved
      CMD57..CMD59              Reserved
      CMD60..CMD63              Reserved for Manufacturer
      SPI Mode
      CMD58 READ_OCR            SPI-only
      CMD59 CRC_ON_OFF          SPI-only

NOTE 1. Due to legacy considerations, a card may treat CMD24/25 during a prg state_while busy is active_as a legal or an illegal command. A card that treats CMD24/25 during a prg-state_while busy is active_as an illegal command will not change its state to the rcv state. A host should not send CMD24/25 while the card is in prg state and busy is active.
NOTE 2. Due to legacy considerations, a card may treat CMD24/25 during a prg state_while busy is active_as a legal or an illegal command. A card that treats CMD24/25 during a prg state_while busy is active_as an illegal command will not change its state to the rcv state. A host should not send CMD24/25 while the card is in prg state and busy is active.
NOTE 3. As there is no way to obtain state information in boot mode, boot-mode states are not shown in this table.

      pre  Pre-idle
      idl  idle
      rdy  ready
      idt  ident
      stb  stby
      trn  tran
      dta  data
      tst  btst

DSi SD/MMC Protocol: Signals

XXX...
SD Mode 1-bit data transfer mode

              __ start bit                             __ checksum bits (CRC-CCITT)
             |                                        |
             |  <------------data bits------------->  |   __ stop bit
             |                                        |  |
      DAT0   0  1st 2nd 3rd 4th 5th 6th 7th ... last crc 1

SD Mode 4-bit data transfer mode

              __ start bit         __ checksum bits (CRC-CCITT)
             |                    |
             |  <--data bits-->   |   __ stop bit
             |                    |  |
      DAT3   0  1st 5th ... ...  crc 1
      DAT2   0  2nd 6th ... ...  crc 1
      DAT1   0  3rd 7th ... ...  crc 1
      DAT0   0  4th 8th ... last crc 1

DSi SDIO Special SDIO Commands

CMD52 - SDIO: IO_RW_DIRECT
Read/write single byte. Mostly used for detection/configuration via SDIO Function 0 commands.

      31     R/W Flag               (0=Read, 1=Write)
      30-28  Function Number (3bit)
      27     Read-after-write (RAW) Flag (if Bit31=1=Write, and Bit27=1)
      26     Stuff (unspecified, should be probably 0, but is 1 on DSi)
      25-9   Register Address (17bit)
      8      Stuff (unspecified, should be probably 0, but is 1 on DSi)
      7-0    Write Data (8bit), or Stuff bits (for read)

SD Mode Response: R5:

      47      Start Bit (0)                                 ;\
      46      Transmission To Host (0)                      ; 1st byte
      45-40   Command (the 6bit CMD being responded to)     ;/
      39-24   Stuff Bits                                    ;-2nd..3rd byte
      23-16   Response Flags                                ;-4th byte
               7   COM_CRC_ERROR
               6   ILLEGAL_COMMAND
               5-4 IO_CURRENT STATE (0=dis, 1=cmd, 2=trn(cmd53), 3=rfu)
               3   ERROR
               2   RFU (reserved for future use)
               1   INVALID_FUNCTION_NUMBER
               0   OUT_OF_RANGE
      15-8    Read or Write Data (8bit)                     ;-5th byte
      7-1     CRC7                                          ;\6th byte
      0       End Bit (1)                                   ;/

SPI Mode Response: R5:

      8bit  modified R1 response
               7  start bit (0)
               6  parameter error       (0=okay, 1=error)
               5  RFU (0)
               4  function number error (0=okay, 1=error)
               3  COM CRC error         (0=okay, 1=error)
               2  illegal command       (0=okay, 1=error)
               1  RFU (0)
               0  in idle state         (0=no, 1=idle)
      8bit  Read or Write Data

CMD53 - SDIO: IO_RW_EXTENDED
Mostly used for actual command/data transfers via SDIO Function 1 commands.

      31     R/W Flag               (0=Read, 1=Write)
      30-28  Function Number (3bit) (0=CIA)
      27     Block Mode             (0=Bytes, 1=Blocks/optional)
      26     OP Code                (0=Fixed Address, 1=Incrementing Address)
      25-9   Register Address (17bit)
      8-0    Byte/Block Count (9bit) (1..511) (0=512 Bytes, or 0=Infinite Blocks)

Response: R5: Same as for CMD52 (with 8bit data = 00h)
Data Transfer:

      For Byte Mode: Similar to CMD17/CMD24 (single block)
      For Block Mode: Similar to CMD18/CMD25 (multiple block)
      For Block Mode: CMD52:STOP_TRANSMISSION only needed if using "InfiniteBlocks"

CMD5 - SPI - SDIO: IO_SEND_OP_COND
Similar to SD Memory Card's ACMD41.

      31-25  stuff bits (0)
      24     Switching to 1.8V Request (S18R)
      23     I/O OCR VDD Voltage Window 3.5V-3.6V
      22     I/O OCR VDD Voltage Window 3.4V-3.5V
      21     I/O OCR VDD Voltage Window 3.3V-3.4V
      20     I/O OCR VDD Voltage Window 3.2V-3.3V
      19     I/O OCR VDD Voltage Window 3.1V-3.2V
      18     I/O OCR VDD Voltage Window 3.0V-3.1V
      17     I/O OCR VDD Voltage Window 2.9V-3.0V
      16     I/O OCR VDD Voltage Window 2.8V-2.9V
      15     I/O OCR VDD Voltage Window 2.7V-2.8V
      14     I/O OCR VDD Voltage Window 2.6V-2.7V
      13     I/O OCR VDD Voltage Window 2.5V-2.6V
      12     I/O OCR VDD Voltage Window 2.4V-2.5V
      11     I/O OCR VDD Voltage Window 2.3V-2.4V
      10     I/O OCR VDD Voltage Window 2.2V-2.3V
      9      I/O OCR VDD Voltage Window 2.1V-2.2V
      8      I/O OCR VDD Voltage Window 2.0V-2.1V
      7-4    I/O OCR VDD Voltage Window Reserved
      3-0    I/O OCR VDD Voltage Window Reserved

SD Mode Response: R4:

      47     Start Bit (0)                                 ;\
      46     Transmission To Host (0)                      ; 1st byte
      45-40  Reserved (111111) (instead of Command value)  ;/
      39     Card is ready to operate after init           ;\
      38-36  Number of I/O Functions                       ;
      35     Memory Present                                ; 2nd byte
      34-33  Stuff bits (0)                                ;
      32     Switching to 1.8V Accepted (S18R) (not SPI)   ;/
      31-8   I/O OCR (24bit)                               ;-3rd..5th byte
      7-1    Reserved (111111) (instead of CRC7)           ;\6th byte
      0      End Bit (1)                                   ;/

SPI Mode Response: R4:

      8bit   modified R1 Response
               7  start bit (0)
               6  parameter error       (0=okay, 1=error)
               5  RFU (0)
               4  function number error (0=okay, 1=error)
               3  COM CRC error         (0=okay, 1=error)
               2  illegal command       (0=okay, 1=error)
               1  RFU (0)
               0  in idle state         (0=no, 1=idle)
      32bit  same as SD Response bit39-8 (but without S18R bit)

DSi SDIO Wifi Init
Related required registers/bits are:

     - SCFG_EXT7.bit19 needed for SDIO controller (else 4004Axxh-4004Bxxh disabled)
     - SCFG_CLK7 seems to be NOT needed for SDIO clock enable (unlike SDMMC)
     - SCFG_WL.bit0 seems to be wifi-related (but effect is unknown)
     - GPIO_WIFI.bit8 needed for AR6013G chips (else SDIO Function 1 fails)
     - BPTWL[30h] needed for LED and SDIO (else SDIO fails badly)
     - RTC.FOUT pin as configured by firmware (else WMI commands/events fail)

DSi init sequence is trying to send one CMD52 command first; if that fails, then the DSi is sending several CMD5's, followed by CMD3+CMD7.
SDIO State

      Command                 ini  stb  cmd  trn  ina
      CMD3  SET_RELATIVE_ADDR stb  ok   ---  ---  ---
      CMD5  IO_SEND_OP_COND   ok   ---  ---  ---  ---
             ocr bad          ina  ---  ---  ---  ---
      CMD7  SELECT_CARD       ---  cmd  ok   ---  ---
            DESELECT_CARD     ---  ok   stb  ---  ---
      CMD15 GO_INACTIVE_STATE ina  ina  ina  ---  ---
      CMD52 IO_RW_DIRECT      ---  ---  ok   (cmd)---
      CMD53 IO_RW_EXTENDED    ---  ---  trn  ---  ---

Note: In CMD52, state "dis" can mean state "ini","stb","ina" (though, theoretically CMD52 cannot be used in that states, so one should never see the "dis" state at all).
More SD commands that are (occassionally) used for SDIO

      CMD0  GO_IDLE_STATE     for entering SPI mode only (but does NOT reset SDIO)
      CMD8  SEND_IF_COND      optional for SDHC/SDXC
      CMD11 VOLTAGE_SWITCH    optional for UHS-I
      CMD19 SEND_TUNING_BLOCK optional for UHS-I
      CMD59 CRC_ON_OFF        spi-only

Moreover a combo card (a SDIO device with built-in SD memory card) may implement various SD commands; these commands will affect only the SD memory card side, not the SDIO device).
SDIO doesn't have CID or CSD registers, nor commands for STOP_TRANSMISSION, SET_BUSWIDTH, or SET_BLOCKLEN (but CMD52 can do equivalent stuff via SDIO Function 0 registers).

     ____________________________ I/O Commands for MMC____________________________

CMD39 - MMCIO: FAST_IO (type=ac)

      31-16  RCA
      15     Register Write Flag
      14-8   Register Address
      7-0    Register Data

MMC Response: R4:

      47      Start Bit (0)                                 ;\
      46      Transmission To Host (0)                      ; 1st byte
      45-40   Command (the 6bit CMD being responded to)     ;/
      39-24   RCA                                           ;-2nd..3rd byte
      23      Status (0=Bad, 1=Successful)                  ;\4th byte
      22-16   Register Address                              ;/
      15-8    Read Register Contents                        ;-5th byte
      7-1     CRC7                                          ;\6th byte
      0       End Bit (1)                                   ;/

CMD40 - MMCIO: GO_IRQ_STATE (type=bcr)

      31-0   Stuff Bits

MMC Response: R5:

      47      Start Bit (0)                                 ;\
      46      Transmission To Host (0)                      ; 1st byte
      45-40   Command (the 6bit CMD being responded to)     ;/
      39-24   RCA                                           ;-2nd..3rd byte
      23-8    Not defined (may be used for IRQ data)        ;-4th..5th byte
      7-1     CRC7                                          ;\6th byte
      0       End Bit (1)                                   ;/

DSi SDIO Memory and I/O Maps

Function 0 - Common I/O Area (CIA)

      0:00000h..000FFh  Card Common Control Registers (CCCR)
      0:00100h..001FFh  Function Basic Registers (FBR) for Function 1
      0:00200h..002FFh  Function Basic Registers (FBR) for Function 2
      0:00300h..003FFh  Function Basic Registers (FBR) for Function 3
      0:00400h..004FFh  Function Basic Registers (FBR) for Function 4
      0:00500h..005FFh  Function Basic Registers (FBR) for Function 5
      0:00600h..006FFh  Function Basic Registers (FBR) for Function 6
      0:00700h..007FFh  Function Basic Registers (FBR) for Function 7
      0:00800h..00FFFh  Reserved for Future
      0:01000h..17FFFh  Card Information Structures (Common CIS and Func 1-7 CIS)
      0:18000h..1FFFFh  Reserved for Future

Function 1..7 - Function specific Register Space

      n:00000h..1FFFFh  Registers (seven 128K spaces, one for each function)

Code Storage Area (CSA) (optional, R or R/W)

      CSA:00000h..FFFFFh  16Mbyte FAT12/FAT16 (accessed indirectly via "Window")

Card Common Control Registers (CCCR)

      0:00000h 2   CCCR: Revision (R)
      0:00002h 2   CCCR: I/O Function Enable/Ready (R/W)
      0:00004h 2   CCCR: Interrupt Enable/Pending (R/W)
      0:00006h 1   CCCR: I/O Abort (W)
      0:00007h 1   CCCR: Bus Interface Control (R/W)
      0:00008h 1   CCCR: Card Capability
      0:00009h 3   CCCR: Common CIS Pointer, Lo/Mid/Hi
      0:0000Ch 1   CCCR: Bus Suspend
      0:0000Dh 1   CCCR: Function Select (R/W)
      0:0000Eh 2   CCCR: Exec/Ready Flags (R)
      0:00010h 2   CCCR: CMD53 Block Size for Function 0, Lo/Hi (R/W)
      0:00012h 1   CCCR: Power Control
      0:00013h 2   CCCR: Bus Speed Select
      0:00015h 1   CCCR: Driver Strength
      0:00016h 1   CCCR: Interrupt Extension
      0:00017h D9h CCCR: Reserved for Future
      0:000F0h 10h CCCR: Reserved for Vendors

Function Basic Registers (FBR) for Function n (n=1..7)

      0:00n00h 1    FBR(n): Misc
      0:00n01h 1    FBR(n): Extended standard SDIO Function interface code
      0:00n02h 1    FBR(n): Misc
      0:00n02h 7    FBR(n): Reserved for Future
      0:00n09h 3    FBR(n): Pointer to Card Information Structure (CIS), Lo/Mid/Hi
      0:00n0Ch 3    FBR(n): Code Storage Area (CSA) Address, Lo/Mid/Hi
      0:00n0Fh 1    FBR(n): Code Storage Area (CSA) Data "Window"
      0:00n10h 2    FBR(n): CMD53 Block Size for Function n, Lo/Hi
      0:00n12h EEh  FBR(n): Reserved for Future

DSi SDIO Common Control Registers (CCCR)

0:00000h - CCCR: Revision (R)

      0-3   CCCR/FBR Format Version      (0=v1.00, 1=v1.10, 2=v2.00, 3=v3.00) (R)
      4-7   SDIO Spec Version   (0=v1.00, 1=v1.10, 2=v1.20, 3=v2.00, 4=v3.00) (R)
      8-11  SD Physical Layer Spec       (0=v1.01, 1=v1.10, 2=v2.00, 3=v3.0x) (R)
      12-15 Reserved for Future                                               (-)

0:00002h - CCCR: I/O Function Enable/Ready (R/W)

      0     Reserved for Future                                               (-)
      1-7   SDIO Function 1..7 Enable Flags             (0=Disable, 1=Enable) (R/W)
      8     Reserved for Future                                               (-)
      9-15  SDIO Function 1..7 Ready Flags         (0=Disabled/Busy, 1=Ready) (R)

0:00004h - CCCR: Interrupt Enable/Pending (R/W)

      0     SDIO Interrupt Master Enable                (0=Disable, 1=Enable) (R/W)
      1-7   SDIO Function 1..7 Interrupt Enable         (0=Disable, 1=Enable) (R/W)
      8     Reserved for Future                                               (-)
      9-15  SDIO Function 1..7 Interrupt Pending                (0=No, 1=IRQ) (R)

0:00006h - CCCR: I/O Abort (W)

      0-2   SDIO Function Number to be Aborted  (0=None?, 1..7=Function 1..7) (W)
                XXXsee pg 35
      3     Reset SDIO Card                               (0=Normal, 1=Reset) (W)
      4-7   Reserved for Future                                               (-)

0:00007h - CCCR: Bus Interface Control (R/W)

      0-1   Bus Width       (0=1bit, 1=Reserved, 2=4bit, 3=EmbeddedSDIO/8bit) (R/W)
      2     Support 8bit Bus Flag             (0=No, 1=Yes/EmbeddedSDIO only) (R)
      3-4   Reserved for Future                                               (-)
      5     Enable Continous SPI Interrupt              (0=Disable, 1=Enable) (R/W)
      6     Support Continous SPI Interrupt                     (0=No, 1=Yes) (R)
      7     Card Detect Disable     (0=Enable Pull-up on DAT3 pin, 1=Disable) (R/W)

0:00008h - CCCR: Card Capability

      0     Support Direct Command (CMD52) during Data Transfer (0=No, 1=Yes) (R)
      1     Support Multi-Block transfer (CMD53.block mode)     (0=No, 1=Yes) (R)
      2     Support Read Wait Control (RWC via DAT2 pin)        (0=No, 1=Yes) (R)
      3     Support Bus Control Suspend/Resume                  (0=No, 1=Yes) (R)
      4     Support Block Gap Interrupt during Multi-Block      (0=No, 1=Yes) (R)
      5     Enable Block Gap Interrupt during Multi-Block    (0=No, 1=Enable) (R/W)
      6     Low Speed Card                        (0=Full-Speed, 1=Low-Speed) (R)
      7     Support 4bit Mode for Low-Speed Card                (0=No, 1=Yes) (R)

0:00009h - CCCR: Common CIS Pointer, Lo
0:0000Ah - CCCR: Common CIS Pointer, Mid
0:0000Bh - CCCR: Common CIS Pointer, Hi

      0-16  Pointer to Card Common Card Information Structure (Common CIS)    (R)
      17-23 Unspecified (probably reserved)                                   (-)

0:0000Ch - CCCR: Bus Suspend

      0     Bus Status              XXX see pg 37                             (R)
      1     Bus Release Request     XXX see pg 38                             (R)
      2-7   Reserved for Future                                               (-)

0:0000Dh - CCCR: Function Select (R/W)

      0-3   Select Function (0=CIA, 1..7=Function 1..7, 8=Memory Card)        (R/W)
      4-6   Reserved for Future                                               (-)
      7     Data Flag (more data after resuming) (0=No, 1=Yes)                (R)

0:0000Eh - CCCR: Exec/Ready Flags (R)

      0     Command Execution Flag for Memory (=SD/Combo? or CSA?)            (R)
      1-7   Command Execution Flags for Function 1..7       (0=Busy, 1=Ready) (R)
      8     Read/Write Ready Flag for Memory (=SD/Combo? or CSA?)             (R)
      9-15  Read/Write Ready Flags for Function 1..7        (0=Busy, 1=Ready) (R)

0:00010h - CCCR: CMD53 Block Size for Function 0, Lo (R/W)
0:00011h - CCCR: CMD53 Block Size for Function 0, Hi (R/W)

      0-15  CMD53 Block size for Function(0)          (0001h..0800h) (0=None) (R/W)

0:00012h - CCCR: Power Control

      0     Support Master Power Control                        (0=No, 1=Yes) (R)
      1     Enable Master Power Control    (0=No/max 720mW, 1=Yes/allow more) (R/W)
      2-7   Reserved for Future                                               (-)

0:00013h,00014h - CCCR: Bus Speed Select

      0     Support High-Speed Mode (SDR25 or higher)           (0=No, 1=Yes) (R)
      1-3   Bus Speed Select   (0=SDR12, 1=SDR25, 2=SDR50, 3=SDR104, 4=DDR50) (R/W)
      4-7   Reserved for Future                                               (-)
      8     Support UHS-I SDR50  (usable in 1.8V mode only)     (0=No, 1=Yes) (R)
      9     Support UHS-I SDR104 (usable in 1.8V mode only)     (0=No, 1=Yes) (R)
      10    Support UHS-I DDR50  (usable in 1.8V mode only)     (0=No, 1=Yes) (R)
      11-15 Reserved for Future

0:00015h - CCCR: Driver Strength

      0     Support Driver Type A ;\see Physical Layer Specs    (0=No, 1=Yes) (R)
      1     Support Driver Type C ; version 3.0x for details    (0=No, 1=Yes) (R)
      2     Support Driver Type D ;/                            (0=No, 1=Yes) (R)
      3     Reserved for Future                                               (-)
      5-4   Driver Type Select    (0=Default/B, 1=Type A, 2=Type C, 3=Type D) (R/W)
      7-6   Reserved for Future                                               (-)

0:00016h - CCCR: Interrupt Extension

      0     Support Asynchronous Interrupt in 4bit mode         (0=No, 1=Yes) (R)
      1     Enable Asynchronous Interrupt in 4bit mode       (0=No, 1=Enable) (R/W)
      7-2   Reserved for Future                                               (-)

DSi SDIO Function Basic Registers (FBR)

0:00n00h - FBR(n): Interface Type

      0-3   Standard SDIO Function Interface Code                             (R)
      4-5   Reserved for Future                                               (-)
      6     Code Storage Area (CSA) Supported                   (0=No, 1=Yes) (R)
      7     Code Storage Area (CSA) Enable   (0=Block reads/writes, 1=Enable) (R/W)
      8-15  Extended standard SDIO Function interface code  (when bit0-3=0Fh) (R)

The interface type is merged of bit0-3 and bit8-15:

      0h:00h = No SDIO standard interface (eg. Atheros Wifi in DSi)
      1h:00h = SDIO Standard UART
      2h:00h = SDIO Bluetooth Type-A standard interface
      3h:00h = SDIO Bluetooth Type-B standard interface
      4h:00h = SDIO GPS standard interface
      5h:00h = SDIO Camera standard interface
      6h:00h = SDIO PHS standard interface
      7h:00h = SDIO WLAN interface
      8h:00h = Embedded SDIO-ATA standard interface
      9h:00h = SDIO Bluetooth Type-A Alternate MAC PHY (AMP) standard interface
      Ah:00h = Reserved for Future
      Bh:00h = Reserved for Future
      Ch:00h = Reserved for Future
      Dh:00h = Reserved for Future
      Eh:00h = Reserved for Future
      Fh:00h..FFh = Reserved for Future

0:00n02h - FBR(n): Power

      0     Support Power Selection                             (0=No, 1=Yes) (R)
      1     Enable Power Selection        (0=Normal Current, 1=Lower Current) (R/W)
      2-3   Reserved for Future                                               (-)
      4-7   Power State                                                       (R/W)

0:00n09h-00n0Bh - FBR(n): Pointer to Card Information Structure (CIS)

      0-16  Pointer to Function(n)'s Card Information Structure (Function CIS)(R)
      17-23 Unspecified (probably reserved)                                   (-)

Should point to "End-of-Chain Tuple" for unsupported functions?
0:00n0Ch-00n0Eh - FBR(n): Code Storage Area (CSA) Address (R/W)

      0-23  Pointer to CSA memory (incremented after CSA data read/write)     (R/W)

0:00n0Fh - FBR(n): Code Storage Area (CSA) Data "Window" (R or R/W)

      0-7   Data (to/from auto-incrementing CSA Address) (R for ROM, R/W otherwise)

0:00n10h-00n11h - FBR(n): CMD53 Block Size (R/W)

      0-15  CMD53 Block size for Function(n)          (0001h..0800h) (0=None) (R/W)

DSi SDIO Card Information Structures (CIS)

The CIS used by SDIO is based directly upon the metaformat specification used by PCMCIA and Compact Flash. For details on the metaformat, refer to:

      PC Card Standard, Volume 4, Metaformat Specification

Published by: PCMCIA (Personal Computer Memory Card International Association)
Basic Format

      00h           CISTPL_code
      01h           Offset to next tuple (n) (aka size of body)
      02h+(0..n-1)  Body (n bytes)

Summary

      00h = CISTPL_NULL          Null Tuple
      10h = CISTPL_CHECKSUM      Checksum Control
      15h = CISTPL_VERS_1        Level 1 Version/Product Information
      16h = CISTPL_ALTSTR        Alternate Language String
      20h = CISTPL_MANFID        Manufacturer ID
      21h = CISTPL_FUNCID        Function ID
      22h = CISTPL_FUNCE         Function Extensions
      80h-8Fh = Vendor specific  Vendor specific
      91h = CISTPL_SDIO_STD      Info for Standard SDIO Functions
      92h = CISTPL_SDIO_EXT      Reserved for future SDIO stuff
      FFh = CISTPL_END           End-of-chain

Tuple 00h - Null Tuple (meaningless, unknown purpose)

      00h Tuple ID   (00h)
      01h Tuple Size (00h)

Unspecified in SDIO reference... but maybe defined in PCMIA specs?)
Tuple 10h - Checksum Control

      00h Tuple ID   (10h)
      01h Tuple Size (?)
      ... Unknown

Unspecified in SDIO reference... but maybe defined in PCMIA specs?)
Tuple 15h - Level 1 Version/Product Information

      00h Tuple ID   (15h)
      01h Tuple Size (?)
      ... Unknown

Unspecified in SDIO reference... but maybe defined in PCMIA specs?)
Tuple 20h - Manufacturer ID

      00h      Tuple ID   (20h)
      01h      Tuple Size (at least 4)
      02h-03h  Manufacturer ID (assigned by JEIDA or PCMCIA)
      04h-05h  Part Number/Revision (manufacturer specific)

Tuple 21h - Function ID

      00h      Tuple ID   (21h)
      01h      Tuple Size (2)
      02h      Card Function Code (0Ch for SDIO)
      03h      System initialization bit mask (Not used, 00h)

Tuple 22h - Function Extension

      00h      Tuple ID   (22h)
      01h      Tuple Size (..)
      02h      Type of extended data
      03h..xxh Function information

Tuple 22h - Function Extension, Type 00h, for Function 0

      00h      Tuple ID   (22h)
      01h      Tuple Size (04h+2*N)
      02h      Type of extended data (00h=Type 00h)
      03h-04h  Max Block Size for Function 0 (0001h or higher)
      05h      Max Transfer Speed for Function 0-7 (specified as Value*Unit bits/s)
               bit0-2: Unit  (0=0.1M, 1=1M, 2=10M, 3=100M, 4..7=Reserved)
               bit3-6: Value (0=Reserved, 1=1, 2=1.2, 3=1.3, 4=1.5, 5=2, 6=2.5,
                       7=3, 8=3.5, 9=4, 10=4.5, 11=5, 12=5.5, 13=6, 14=7, 15=8)
               bit7:   Reserved
      06h...   N two-byte pairs (TC,CP) for 1..N   ;(N=([01h]-4)/2)

Tuple 22h - Function Extension, Type 01h, for Function 1-7

      00h      Tuple ID   (22h)
      01h      Tuple Size (2Ah)
      02h      Type of extended data (01h=Type 01h)
      03h      Function Info (bit0=WakeUpSupport, bit1..7=Reserved)
      04h      Standard SDIO Function version (2x4bit maj.min, or 00h=Nonstandard)
      05h-08h  Card Product Serial Number PSN (32bit) (unique value, or 0=None)
      09h-0Ch  CSA Size in bytes available for this Function (32bit)
      0Dh      CSA Property (bit0=WriteProtected/ReadOnly, bit1=NoReformatting)
      0Eh-0Fh  Max Block Size for this Function (0001h or higher)
      10h-13h  Operation Condition OCR (same as in ACMD41 for SD Memory devices)
      14h-16h  3x8bit Operation Power (Min/Average/Max) (0..254mA, or 255=more)
      17h-19h  3x8bit Standby Power   (Min/Average/Max) (0..254mA, or 255=more)
      1Ah-1Dh  2x16bit Bandwidth      (Min/Optimal) (1..65535 KB/sec, or 0=None)
      1Eh-1Fh  Timeout for Enable-till-Ready in 10ms units (max 655.35 seconds)
      20h-23h  2x16bit Operation 3.3V         (Average/Max) (1..65535mA, or 0=?)
      24h-25h  2x16bit High-Current-Mode 3.3V (Average/Max) (1..65535mA, or 0=?)
      28h-2Bh  2x16bit Low-Current-Mode 3.3V  (Average/Max) (1..65535mA, or 0=?)

Tuple 22h - Function Extension, Type 02h, for Function 1-7 (Power State)

      00h      Tuple ID   (22h)
      01h      Tuple Size (02h+N*2) (N=1..15, for up to 15 power states)
      02h      Type of extended data (02h=Type 02h)
      03h      Fixed value (00h)
      04h..xxh Nx16bit Max consumption in Power State 1..N (0..65535mW)

Tuple 91h - SDIO_STD - Info about Standard SDIO Functions

      00h      Tuple ID   (91h)
      01h      Tuple Size (02h..FFh)
      02h      SDIO STD ID (the 4+8bit Interface Type in FBR, squeezed into 8bits?)
      03h      SDIO STD Type           ;\depends on Interface Type
      04h...   SDIO STD Data (if any)  ;/

Tuple 92h - SDIO_EXT

      00h      Tuple ID   (92h)
      01h      Tuple Size (?)
      02h...   Reserved (if any)

Tuple FFh - END

      00h      Tuple ID   (FFh)

Indicates the end of tuple's list. Unlike all other tuple's, this is only a single FFh-byte (without "Tuple Size" entry).
01 CISTPL_DEVICE
14 CISTPL_NO_LINK
1A CISTPL_CONFIG
1B CISTPL_CFTABLE_ENTRY

DSi SD/MMC Filesystem

DSi Partition Table and FAT Filesystems
DSi SD/MMC Partition Table (aka Master Boot Record aka MBR)
DSi SD/MMC Filesystem (FAT)
System Tools and DSiware games are having regular "ROM Cartridge" headers, with NitroROM filesystem defined in that headers (ie. the ".app" files are internally containing a 2nd filesystem inside of the FAT filesystem; eventually there can be also NARC files as 3rd filesystem inside of the NitroROM filesystem).
DSi Cartridge Header
DS Cartridge NitroROM and NitroARC File Systems
Savedata for DSiWare games is usually stored in "public.sav" or "private.sav" files. That .sav files are usually containing a FAT12 with its own VBR, FAT, and Directories (so they use some virtual FAT12 inside of the real FAT16).
DSi Filesystem Overview
DSi SD/MMC Internal NAND Layout
DSi SD/MMC Bootloader
DSi SD/MMC Device List
DSi SD/MMC Complete List of SD/MMC Files/Folders
DSi SD/MMC Summary of SD/MMC Files/Folders
DSi SD/MMC Images
DSi Autoload on Warmboot
DSi Files
DSi SD/MMC DSiware Files on Internal eMMC Storage
DSi SD/MMC DSiware Files on External SD Card (.bin aka Tad Files)
DSi SD/MMC DSiware Files from Nintendo's Server
DSi SD/MMC DSiware Tickets and Title metadata
DSi SD/MMC Firmware dev.kp and cert.sys Certificate Files
DSi SD/MMC Firmware Certificate/Keys (DER)
DSi SD/MMC Firmware Font File
DSi SD/MMC Firmware Log Files
DSi SD/MMC Firmware Misc Files
DSi SD/MMC Firmware Wifi Firmware
DSi SD/MMC Firmware System Settings Data Files
DSi SD/MMC Firmware Version Data File
DSi SD/MMC Firmware Nintendo DS Cart Whitelist File
DSi SD/MMC Camera Files - Overview
DSi SD/MMC Camera Files - JPEG's
DSi SD/MMC Camera Files - pit.bin
DSi SD/MMC Flipnote Files
DS File Formats

DSi SD/MMC Partition Table (aka Master Boot Record aka MBR)

DSi eMMC Partition table
The decrypted DSi MBR contains (for 240MB chips; 3rd part differs for 245.5MB):

      0000  00 00 00 00 00 00 00 00 .. .. .. .. 00 00        ;bootcode (zero)
      01BE  00 03 18 04 06 0F E0 3B 77 08 00 00 89 6F 06 00  ;1st partition (main)
      01CE  00 02 CE 3C 06 0F E0 BE 4D 78 06 00 B3 05 01 00  ;2nd partition (photo)
      01DE  00 02 DE BF 01 0F E0 BF 5D 7E 07 00 A3 01 00 00  ;3rd partition (extra)
      01EE  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ;4th partition (none)
      01FE  55 AA                                            ;mbr id (55h,AAh)

Above values are following the classical standard MBR format:

      000h      446  bootcode (zerofilled on DSi)                   ;-bootcode
      1BEh+n*10h  1  status (00h)                                   ;\
      1BFh+n*10h  3  chsFirst                                       ; four
      1C2h+n*10h  1  type (00h=unused, 01h=FAT12, 06h=FAT16B)       ; partitions
      1C3h+n*10h  3  chsLast                                        ; (n=0..3)
      1C6h+n*10h  4  lbaFirst  ;\logical block addresses/sizes      ;
      1CAh+n*10h  4  lbaSize   ;/counted in 200h-byte sectors       ;/
      1FEh        2  mbrsig (55h,AAh)                               ;-MBR ID

The CHS and LBA values are essentially containing the same information (CHS being an older standard, and LBA being invented in 1996). The 24bit CHS values are encoded as:

      0-7    Head Bit0-7     (00h..FEh) (or less common, 00h..FFh)
      8-13   Sector Bit0-5   (01h..3Fh)
      14-15  Cylinder Bit8-9
      16-23  Cylinder Bit0-7 (000h..3FFh, with above bit8-7)

To convert CHS to LBA, one must know the number of (logical) heads and sectors per cylinder (that info isn't stored in the MBR). The DSi's eMMC uses 32 sectors, 16 heads, 1024 cylinders:

      LBA = (Cylinder*32*16) + (Head*32) + (Sector-1)

Anyways, it's better/easier to use the LBA values directly, and ignore the CHS values.
3DS eMMC Partition table
Contents are unknown. The 3DS is said to have more than four partitions, so it must be using some extended MBR variant. Reportedly there's some extra "NCSD" header in the MBR sector.
SD/MMC Card Partition table
SD/MMC Cards are shipped with pre-formatted filesystem, so they should stick to some standarized MBR variant, with only a single partition used, possibly with additional date/id fields(?).
Note that SD/MMC Cards may or may not use partition tables (see CSD Register, FILE_FORMAT entry).
Formatting and Reformatting
SD/MMC cards are usually pre-formatted with empty filesystems. Reformatting should be avoided, or should be done only with tools that are aware of some memory card specific requirements:
The cluster size should not be less than the physical sector size (otherwise, when writing smaller clusters, sectors may get erased multiple times, which would result in slower writing and reduced lifetime).
Many devices do support only the standard FAT filesystems (for example, cameras or mp3-players may be unable to access memory cards with NTFS filesystem).
More info
For more info on MBR variants (and on the Partition Type value at 1C2h+n*10h), see:

      http://en.wikipedia.org/wiki/Master_Boot_Record
      http://en.wikipedia.org/wiki/Partition_type <-- rather meaningless

DSi SD/MMC Filesystem (FAT)

Volume Boot Record (VBR) (FAT12/FAT16) (DOS 4.0 EBPB)

      000h 3   80x86 jump opcode       (DSi: E9h,00h,00h)
      003h 8   ascii disk name         (DSi: "TWL     ")
      00Bh 2   bytes / sector          (DSi: 0200h)
      00Dh 1   sectors / cluster       (DSi: 20h)
      00Eh 2   sectors / boot-record   (DSi: 0001h)
      010h 1   number of FAT-copys     (DSi: 02h)
      011h 2   entrys / root-directory (DSi: 0200h)
      013h 2   sectors / disk          (DSi: 0000h)
      015h 1   ID                      (DSi: F8h=HDD)
      016h 2   sectors / FAT           (DSi: A:0034h, B:0009h)
      018h 2   sectors / track         (DSi: 0020h)
      01Ah 2   heads / disk            (DSi: 0010h)
      01Ch 2   number of reserved sectors    (DSi: None such entry!)
      01Ch 4   LBA First "hidden"      (DSi: A:00000877h, B:0006784Dh)
      020h 4   LBA Size (total sectors)(DSi: A:00066F89h, B:000105B3h)
      024h 1   Drive Number            (DSi: A:00h, B:01h)
      025h 1   Flags (reserved)        (DSi: 00h)
      026h 1   EBPB Version            (DSi: 29h) (that is, DOS 4.0 EBPB)
      027h 4   Volume Serial Number    (DSi: 12345678h)
      02Bh 11  Volume Label            (DSi: "           ")
      036h 8   Filesystem Type         (DSi: 00h-filled)
      03Eh 448 Bootcode                (DSi: 00h-filled)
      1FEh 2   Signature               (DSi: 55h,AAh)

SDHC carts use FAT32, which differs in entries 011h, 016h and 024h-059h:

      011h 2   Must be 0 (number of root entries, is variable-length FAT chain)
      016h 2   Must be 0 (sectors per fat, instead use 32bit value at 024h)
      024h 4   sectors / FAT  (new 32bit value instead of old entry 016h)
      028h 2   ExtFlags (related to "active" FAT copy)
      02Ah 2   Version of FAT32 filesystem (minor, major) (should be 0.0)
      02Ch 4   Cluster number of first Root directory cluster (usually/often 2)
      030h 2   Sector number of FSINFO in reserved area (usually 0001h)
      032h 2   Sector number of VBR backup copy in reserved area (usually 0006h)
      034h 12  Reserved for future   ;Should be zerofilled
      040h 1   Drive Number                                               ;\
      041h 1   Flags (reserved)                                           ; as old
      042h 1   EBPB Version          ;Must be 29h (that is, DOS 4.0 EBPB) ; entries
      043h 4   Volume Serial Number                                       ; at 024h
      047h 11  Volume Label                                               ;
      052h 8   Filesystem Type       ;Must be "FAT32   "                  ;/

Moreover, FAT32 has the "FSINFO" at sector number VBR[30h]:

      000h 4   Value 41615252h (aka "RRaA")
      004h 480 Reserved (should be 0)
      1E4h 4   Value 61417272h (aka "rrAa")
      1E8h 4   Hint on number of free clusters   (or FFFFFFFFh=unknown)
      1ECh 4   Hint on first free cluster number (or FFFFFFFFh=unknown)
      1F0h 12  Reserved (should be 0)
      1FCh 4   Value AA550000h

For more info see http://en.wikipedia.org/wiki/BIOS_Parameter_Block and fatgen103.pdf (official specs from microsoft).
File Allocation Table - FAT and FAT copy(s)
The following sectors are occupied by the File Allocation Table (FAT), which contains 12bit, 16bit, or 32bit entries (for FAT12/16/32) for each cluster:

      (x000)(0)000      unused, free
      (x000)(0)001      ???
      (x000)(0)002...   pointer to next cluster in chain (0)002..(F)FEF
      (xFFF)(F)FF0-6    reserved (no part of chain, not free)
      (xFFF)(F)FF7      defect cluster, don't use
      (xFFF)(F)FF8-F    last cluster of chain

The "x" in MSB of FAT32 entries is reserved (ie. FAT32 is restricted to 28bit cluster numbers).
Number and size of FATs can be calculated by the information in the boot sector.
Note on The first two FAT entries:
"The first cluster of the data area is cluster #2. That leaves the first two entries of the FAT unused. In the first byte of the first entry a copy of the media descriptor is stored. The remaining bits of this entry are 1. In the second entry the end-of-file marker is stored. The high order two bits of the second entry are sometimes, in the case of FAT16 and FAT32, used for dirty volume management: high order bit 1: last shutdown was clean; next highest bit 1: during the previous mount no disk I/O errors were detected.
(Historically this description has things backwards: DOS 1.0 did not have a BIOS Parameter Block, and the distinction between single-sided and double-sided 5.25" 360K floppies was indicated by the first byte in the FAT. DOS 2.0 introduced the BPB with media descriptor byte.)"
Root directory
The following sectors are the Root directory, again, size depends on the info in bootsector (on FAT32 is it's a normal cluster chain with variable size). Each entry consists of 32 bytes:

      00-07  8    Filename (first byte: 00=free entry, 2E=dir, E5=deleted entry)
      08-0A  3    Filename extension
      0B     1    Fileattribute
                    bit0 read only
                    bit1 hidden
                    bit2 system
                    bit3 volume label
                    bit4 subdirectory
                    bit5 archive-flag
                    bit6 reserved
                    bit7 reserved
      0C-0D  2    Reserved, or stuff
      0E-0F  2    Reserved, or Creation Timestamp
      10-11  2    Reserved, or Creation Datestamp
      12-13  2    Reserved, or Last Access Datestamp
      14-15  2    Reserved, or MSBs of Cluster (for FAT32)
      16-17  2    Last Modify Timestamp: HHHHHMMM, MMMSSSSS
      18-19  2    Last Modify Datestamp: YYYYYYYM, MMMDDDDD
      1A-1B  2    Pointer to first Cluster of file
      1C-1F  4    Filesize in bytes (always 0 for directories)

The 'cluster' entry points to the first used cluster of the file. The FAT entry for that cluster points to the next used cluster (if any), the FAT entry for that cluster points to the next cluster, and so on.
Long File Names (LFNs)
Long File Names (LFNs) are occupying multiple continous directory entries, consisting of a normal short filename entry, preceeded by one or more LFN prefix entries (with Attribute=0Fh). Each LFN prefix can hold 13 characters, the total length should not exceed 255 characters. The name should be terminated by 0000h, and any remaining unused characters should be padded by FFFFh. The LFN prefix entries are using the following format:

      00h  1  Sequence Number (bit6: last logical, first physical LFN entry,
              bit5: 0, bit4-0: number 01h..14h (1Fh)) (or E5h=deleted entry)
      01h  10 Long Filename characters (five UCS-2 characters)
      0Bh  1  Attributes (always 0Fh for LFN prefix)
      0Ch  1  Type (always 00h)
      0Dh  1  Short Filename Checksum
              sum=00h, for i=0 to 10, sum = (sum ROR 1) + shortname_char[i], next i
      0Eh  12 Long Filename characters (six UCS-2 characters)
      1Ah  2  First cluster (always 0000h)
      1Ch  4  Long Filename characters (two UCS-2 characters)

For example, "File with very long filename.ext" would be formatted as so:

      Entry 1: LFN Prefix (43h) "me.ext", 0000h, 6xFFFFh
      Entry 2: LFN Prefix (02h) "y long filena"
      Entry 3: LFN Prefix (01h) "File with ver"
      Entry 4: Normal 8.3 short filename entry "FILEWI~1.EXT"

http://en.wikipedia.org/wiki/Design_of_the_FAT_file_system#VFAT_long_file_names
Reserved Sectors (if any)
Usually the number of reserved sectors is zero. If it is non-zero, then the following sector(s) are reserved (and could be used by the boot procedure for whatever purposes).
Data Clusters 0002..nnnn
Finally all following sectors are data clusters. The first cluster is called cluster number (000)(0)002, followed by number (000)(0)003, (000)(0)004, and so on.
http://en.wikipedia.org/wiki/Design_of_the_FAT_file_system

DSi SD/MMC Internal NAND Layout

The DSi uses a 256MB Samsung eMMC moviNAND(?) flash chip, which is a NAND flash chip with a built-in controller that implements a MMC (SDIO?) interface. In many ways, it's like an SD card (or actually: MMC card) in BGA packaging, and some people have successfully read it with modified(why/how?) SD(/MMC?) card readers (is there any standard software that can be used for doing that?). The last 16MB is used for wear-leveling purposes (such as replacing bad blocks), while the first 240MB is used for storing actual data.
Addressing is done in terms of 512-bytes sectors. All wear-levelling and bad-block-mapping is handled transparently inside the chip by the controller. Most sectors are encrypted with a per-console key.
Overall eMMC Layout

      Offset     Size     Description
      00000000h  200h     PC-style MBR, encrypted with a per-console key
      00000200h  200h     Stage 2 Boot Info Block 1 (used)
      00000400h  200h     Stage 2 Boot Info Block 2 (unused, same as above)
      00000600h  200h     Stage 2 Boot Info Block 3 (unused, nonsense NAND offsets)
      00000800h  26600h   Stage 2 ARM9 Bootcode (encrypted with universal key)
      00026E00h  27600h   Stage 2 ARM7 Bootcode (encrypted with universal key)
      0004E400h  400h     Stage 2 Footer -- unknown format, but first 10 bytes
                            are (unencrypted) build number of Stage 2 bootloader
      0004E800h  B1000h   Unused (all 00h)
      000FF800h  200h     Unused (all 00h) (or No$gba Footer with CID & Console ID)
      000FFA00h  400h     Diagnostic area. (often contains build date of
                            device in plaintext) Blank in never-before-booted
                            DSi. Might be written to during firmware updates.
      000FFE00h  200h     Unused (all FFh)
      00100000h  EE00h    Unused (all 00h)
      0010EE00h  CDF1200h 1st partition (205.9Mbyte) (main, encrypted, FAT16)
      0CF00000h  9A00h    Unused (all 00h)
      0CF09A00h  20B6600h 2nd partition (32.7Mbyte)  (photo, encrypted, FAT12)
     For 240.0MB chips (Samsung KMAPF0000M-S998 or KLM5617EFW-B301):
      0EFC0000h  BA00h    Unused (all 00h)
      0EFCBA00h  34600h   3rd partition (0.2Mbyte)   (extra, unformatted)
      0F000000h  -        End of 240MByte Address Space
     For 245.5MB chips (ST NAND02GAH0LZC5, both rev30 and rev31):
      0EFC0000h  B600h    Unused (all 00h?) (smaller unused area as in 240MB chip)
      0EFCB600h  5B4A00h  3rd partition (5.7Mbyte)   (extra, unformatted)
      0F580000h  -        End of 245.5MByte Address Space

Stage 2 Boot Info Blocks 1, 2, 3 (unencrypted, aside from the RSA block)

      000h 20h Zerofilled
      020h 4   ARM9 Bootcode NAND Offset         (800h)      (Info Block 3: 80400h)
      024h 4   ARM9 Bootcode Size actual         (26410h)
      028h 4   ARM9 Bootcode RAM Address / Entry (37B8000h)
      02Ch 4   ARM9 Bootcode Size rounded-up     (26600h)
      030h 4   ARM7 Bootcode NAND Offset         (26E00h)    (Info Block 3: A6A00h)
      034h 4   ARM7 Bootcode Size actual         (27588h)
      038h 4   ARM7 Bootcode RAM Address / Entry (37B8000h)
      03Ch 4   ARM7 Bootcode Size rounded-up     (27600h)
      040h BFh Zerofilled
      0FFh 1   Unknown (0Ch)
      100h 80h RSA Block (B3,FF,EC,E5,..)       (Boot Info Block 3: 5B,E1,7A,9F,..)
      180h 14h Global MBK1..MBK5 Slot Settings
      194h 0Ch Local ARM9 MBK6..MBK8 Settings
      1A0h 0Ch Local ARM7 MBK6..MBK8 Settings
      1ACh 4   Global MBK9 Slot Write Protect (FF000000h)
      1B0h 50h Zerofilled

The above RSA Block contains 74h bytes of information (plus 0Bh bytes padding):

      Pre  0Bh  Leading RSA Padding (01,FF,FF,FF,FF,FF,FF,FF,FF,FF,00)
      00h  10h  AES_Engine Key Y for ARM9/ARM7 Bootcode (EC,07,00,00,...)
      10h  14h  SHA1 on WifiFlash[00h..27h] and eMMCBootInfo[00h..FFh,180h..1FFh]
                3DS: reportedly NAND/MBR[00h..27h] instead of WifiFlash[00h..27h]??
      24h  14h  SHA1 on decrypted ARM9 Bootcode, with the actual binary size
      38h  14h  SHA1 on decrypted ARM7 Bootcode, with the actual binary size
      4Ch  14h  Zerofilled
      60h  14h  SHA1 on above 60h-byte area at [00h..5Fh] (63,D2,FC,6E,...)

eMMC Encryption for Boot Sectors (AES-CTR, with fixed key; from RSA block)
The ARM9/ARM7 bootcode is encrypted via AES-CTR:

      RSA_KEY  = F1,F5,1A,FF,...         ;-from 3DS TWL_FIRM (for RSA Block)
      IV[0..3] = +size                   ;\
      IV[4..7] = -size                   ; size rounded up to 200h boundary, ie.
      IV[8..B] = -size-1                 ; from Boot Info Block entries [02Ch,03Ch]
      IV[C..F] = 00000000h               ;/
      KEY_X[0..F] = "Nintendo DS",...    ;-same as Key X for "Tad Files"
      KEY_Y[0..F] = EC,07,00,00,...      ;-from RSA Block (see above)

The RSA_KEY key is stored in some non-dumpable area of the DSi BIOS, making it impossible to obtain that key without chip decapping. However, Nintendo has included the same RSA_KEY in the "TWL_FIRM" firmware update for 3DS.
eMMC Encryption for MBR/Partitions (AES-CTR, with console-specific key)
The MBR and both partitions are encrypted via AES-CTR:

      IV[0..F]:    SHA1(CID)+Address/10h                    ;-eMMC Chip ID
      KEY_X[0..3]: [4004D00h]                               ;\
      KEY_X[4..7]: [4004D00h] XOR 24EE6906h                 ; CPU/Console ID, for
      KEY_X[8..B]: [4004D04h] XOR E65B601Dh                 ; DSi partitions on DSi
      KEY_X[C..F]: [4004D04h]                               ;/
      KEY_X[0..3]: [4004D00h]                               ;\CPU/Console ID, for
      KEY_X[4..B]: "NINTENDO"                               ; DSi partitions on 3DS
      KEY_X[C..F]: [4004D04h]                               ;/
      KEY_Y[0..F]: 0AB9DC76h,BD4DC4D3h,202DDD1Dh,E1A00005h  ;-Constant

The CID value (eMMC Chip ID) should be in same format as stored in RAM at 2FFD7BCh: little-endian 120bit (without crc7), padded to 128bit (with MSB=00h), ie. it should look like this (dd/ss being date/serial numbers):

      CID = [2FFD7BCh] = dd,ss,ss,ss,ss,03,4D,30,30,46,50,41,00,00,15,00
      SHA1(CID) = SWI_27h(SHA1value,2FFD7BCh,10h)

The resulting SHA1value is 14h-bytes, the first 10h-bytes are used as IV value, whereas the DSi doesn't adjust the endianness (it does just use the SWI's "big-endian" SHA1value as "little-endian" AES/IV value).
The CTR gets incremented after each 10h bytes (ie. to access a random address: "IV=SHA1value+(address/10h)".
For more info on obtaining the CID and Port [4004D00h] values, see:
DSi Console IDs
See also:
DSi SD/MMC Images
Related Decryption Tools

      "NUS Downloader" allows to download and decrypt system updates
      "DSi SRL Extract" allows to decrypt DSiware files (when copied to SD card)
      "TWLTool" decrypt/encrypt eMMC images (firmware downgrading, dsiware-hax)
      "TWLbf" and "bfCL" bruteforce Console ID or CID (or both) from eMMC images

DSi SD/MMC Bootloader

Stages

      Stage 1: Load Stage 2 from NAND Boot Sectors (via code in BIOS ROM)
      Stage 2: Load Stage 3 from NAND Filesystem
      Stage 3: Contains GUI and allows to boot Cartridges or NAND files

Stage 1
The first stage of the DSi's bootloader lives in ROM, presumably on the CPU die. It loads further encrypted (and probably signed) stages from NAND flash, starting with a (partially unencrypted) offset table in the sector at 0x200.
Not much is known about this bootloader yet, but it presumably knows how to:

      Initialize the encryption hardware
      Read the contents of NVRAM
      Initialize both LCDs
      Read blocks (but not files) from the NAND flash
      Perform some variety of integrity check on all data it reads(signature,CRC,?)
      Display basic hexadecimal error codes
      Possibly factory-programming the NAND flash?
      Might also do basic power-on self test of peripherals

When the Stage 1 bootloader (in ROM) fails, it displays a 32-bit hexadecimal number on the top screen, known Stage 1 error codes are:

      Error Code Description
      0000FE00   Error communicating NAND chip (It's missing, CLK shorted, etc.)
      0000FEFC   Integrity error in first block of Stage 2 (address at 220h)
      0000FEFD   Integrity error in second block of Stage 2 (address at 230h)
      0000FEFE   Boot sector integrity error (Sector 200h not valid), or error
                   in NVRAM contents.

Stage 2
Unlike the stage1 bootloader, which must be small enough to fit in ROM (probably several kilobytes), the stage2 bootloader has about a megabyte of NAND flash reserved for it. The stage2 bootloader understands partitions and filesystems, and it is capable of loading the DSi menu. It also must understand the encryption used on filesystem blocks in the NAND, and it must understand how to load and validate title metadata.
The Stage 2 loader was not modified by the System Menu 1.4 update. This is still earlier in the boot process than the "Health and Safety" warning.
The first stage bootloader reads sector 0x200 in order to find a table of offsets to the Stage 2 bootloader:

      00000220  00 08 00 00 10 64 02 00  00 80 7b 03 00 66 02 00 |.....d....{..f..|
      00000230  00 6e 02 00 88 75 02 00  00 80 7b 03 00 76 02 00 |.n...u....{..v..|
      00000240  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00 |................|

This appears to be describing two chunks of the stage2 loader, one 0x26410 bytes in length at address 0x800, and one 0x27588 bytes at address 0x26e00.
Note that this sector (and two similar ones at 0x400 and 0x600) appear to be the only unencrypted blocks on the NAND flash.
It is unclear why there are two pieces which are nearly but not quite the same size. Passive traces of the boot sequence confirm that the 0x26e00 chunk is slightly larger, and it's loaded first. The 0x800 chunk is read immediately after the 0x26e00 chunk.
Whereas the filesystem data in NAND is encrypted using a unique key for every DSi, the stage2 bootloader is identical on every DSi tested so far. This probably means that it is encrypted using a fixed key included in stage1.
After Stage 2 is loaded:

      1. The NAND flash is partially re-initialized
      2. Sector 0 is read from the NAND. Appears to be (encrypted) DOS-style MBR.
      3. The MBR signature and the type of the first partition are verified.
      4. Filesystem metadata is read from sectors starting around 0x100000. The
           metadata appears to be in FAT format with long filenames.
      5. Multiple files are loaded from the filesystem. The exact read addresses
           will vary depending on your DSi's firmware version and the state of
           its filesystem when you performed the last firmware update. On a brand
           new DSi, it appears that the DSi Menu itself is loaded from 0xb20000
           after two small metadata files are read from 0xb1c000 and 0x7a0000.

All Stage 2 errors show before the health and safety screen. It appears that Stage 2 errors from a cold power-on always cause the DSi to hang at a black screen, whereas Stage 2 errors after reset (pressing but not holding the power button) will give an error message screen. Known Stage 2 errors:

      Text                    Description
      "Error: 1-2435-8325"    Invalid signature or partition type in MBR,
                                invalid starting LBA.
      "Error: 2-2435-8325"    Error reading fat/sectors from eMMC
      "Error: 3-2435-8325"    DSi Menu integrity checks failed

Boot Sectors in DSi Debug version
Debug version bootsectors are almost same as in retail version: There's an extra RSA key inserted at ARM9:37CEADCh, and lots of B/BL/BLX/LDR addresses have changed due to the inserted bytes, but, apart from that changes, only 5 opcodes are really different, ARM9:37C07A0h, ARM9:37C0864h, ARM7:37B9110h, ARM7:37B9200h do trigger errors when SCFG_DEBUG bit0-1 are zero (opposite of retail version), and ARM9:37B8BA4h uses the extra RSA key at 37CEADCh for Debug Launcher (instead of the retail key at 1FFC400h).

DSi SD/MMC Device List

The Device List is automatically copied to ARM7 RAM address defined in cartheader[1D4h] by firmware. The 400h-byte list is mainly used for DSiware/firmware titles (DSi ROM titles will usually just receive an empty zerofilled 400h-byte list; unless maybe if they are flagged to use SD/MMC hardware in cartheader?). There appears to be no range check for the cartheader[1D4h] entry (setting it to zero causes the list to be 'written' to ARM7 ROM area).
Device List, 400h-bytes, loaded to ARM7/RAM address from cartheader[1D4h]

      000h 54h*11 Device List (max 11 entries)
      39Ch 24h    Zerofilled
      3C0h 40h    Name 'nand:/title/000300tt/4ggggggg/content/000000vv.app' + 00h's

Format of the 54h-byte device list entries:

      00h  1    Drive Letter ("A".."I")
      01h  1    Flags (see below)
      02h  1    Access Rights (bit1=Write, bit2=Read)
      03h  1    Zero
      04h  10h  Device Name (eg. "nand" or "dataPub") (zeropadded)
      14h  40h  Path        (eg. "/" or "nand:/shared1") (zeropadded)

Bits in Flags byte:

      0    Physical Drive (0=External SD/MMC Slot, 1=Internal eMMC)
      1-2  Zero (maybe MSBs of Drive)
      3-4  Device Type (0=Physical, 1=Virtual/File, 2=Virtual/Folder, 3=Reserved)
      5    Partition (0=1st, 1=2nd)
      6    Zero (maybe MSB of Partition)
      7    Encrypt? (set for eMMC physical devices; not for virtual, not for SD)

The DSi has 9 default devices ("A"-"I"):

      Letter/Flags     Name       Path                   ;Notes
      'A',81h,06h,00h  'nand'     '/'                    ;eMMC Cart Partition 1
      'B',A1h,06h,00h  'nand2'    '/'                    ;eMMC Cart Partition 2
      'C',11h,04h,00h  'content'  'nand:/title/000300tt/4ggggggg/content'
      'D',11h,04h,00h  'shared1'  'nand:/shared1'        ;TWLCFGn.dat
      'E',11h,06h,00h  'shared2'  'nand:/shared2'        ;Sound and wrap.bin
      'F',31h,06h,00h  'photo'    'nand2:/photo'         ;Camera photos/frames
      'G',09h,06h,00h  'dataPrv'  'nand:/title/000300tt/4ggggggg/data/private.sav'
      'H',09h,06h,00h  'dataPub'  'nand:/title/000300tt/4ggggggg/data/public.sav'
      'I',00h,06h,00h  'sdmc'     '/'                    ;SD Cart Partition 1

Depending on the cartheader, usually only 5-8 of that 9 devices are copied to the device list in RAM, and Access Rights for some devices can be crippled in the RAM list entries).
Caution: The list may not contain forward references (eg. one can redirect "dataPub" to "sdmc:/flipnote.pub", but that works only if "sdmc" was already defined in one of the previous entries).
A and B: These physical eMMC partitions are always included in the list (because they are needed as parent entries for Virtual devices), however, their Access Rights are usually set to 00h (unless Title ID indicates a system file; with cartheader[234h].bit4=1).
C and E: These virtual devices are passed ONLY to System Menu (Launcher)... hmmm, or actually, the Launcher doesn't receive ANY device list at all?
G and H: Present only if Title ID indicates DSiware/firmware; with cartheader[234h].bit2=1 (ie. not ROM carts), and only if public/private.sav sizes are nonzero in carthdr[238h/23Ch].
A-H: removed from list if carthdr[1B4h].4=0 (no eMMC access).
I: removed from list if carthdr[1B4h].3=0 (no SD card access).
Some games may adjust the Device List AFTER booting. For example, Flipnote changes the "photo" (F) Access Rights to 04h, and appends an extra device at the end of the list, using a spare drive letter (C):

      'C',09h,06h,00h  'share'    'nand:/shared2/0000'   ;Sound file

Other device names that have been spotted here or there:

      'verdata'   for Version Data NARC file
      'rom'       for executable's NitroROM filesystem
      'otherPub'
      'otherPrv'

Apart from Virtual Devices, there are also some Virtual Filename Placeholders:

      'nand:/<tmpjump>'     --> 'nand:/tmp/jump.app'
      'nand:/<sharedFont>'  --> 'nand:/sys/TWLFontTable.dat'
      'nand:/<verdata>'     --> 'nand:/title/0003000f/484e4c%02x/content/%08x.app'
      'nand:/<banner>'      --> ..... '/data/banner.sav'
      ':<srl>'              --> .....

public & private savedata
If the file is in a folder named "CONTENT", then savedata is stored in a separata "DATA" folder (this is as how Nintendo is doing it officially):

      "nand:/../CONTENT/title.tmd"
      "nand:/../CONTENT/00000002.app"
      "nand:/../DATA/public.sav"
      "nand:/../DATA/private.sav"

If the file is anywhere else (not in a CONTENT folder), then savedata should be stored in the same folder & same name, with extension changed to .pub or .prv (this homebrew convention allows to use more descriptive non-numeric filenames, and doesn't require "title.tmd"):

      "sdmc:/../My Folder Name/Filpnote Studio (EUR.AUS).dsi"
      "sdmc:/../My Folder Name/Filpnote Studio (EUR.AUS).pub"
      "sdmc:/../My Folder Name/Filpnote Studio (EUR.AUS).prv"

As seen above, names can exceed the 8.3 character shortfilename limit (and can use 16bit unicode), however, using such long filenames can quickly exceed the 64 character limit of the DSi's Device List (or it's 8bit character space), as a workaround, unlaunch is converting the above names to 8.3 character format before storing them in the Device List:

      "sdmc:/../MYFOLD~1/FLIPN~12.DSI"
      "sdmc:/../MYFOLD~1/FLIPN~10.PUB"
      "sdmc:/../MYFOLD~1/FLIPNO~2.PRV"

With those short 8-character folder names, one can have up to five folders nested (or only three folders with extension alike "MYFOLD~1.EXT", or more than five folders if folder/filename are shorter than 8 characters).
As shown in the above examples, the longname ("Filpnote Studio (EUR.AUS)") is same for all three files, but the ~NN suffix may vary for shortnames.

DSi SD/MMC Complete List of SD/MMC Files/Folders

DSi eMMC Partition 1 (FAT16)

      SYS          <DIR>    sys
      LOG          <DIR>     log
      PRODUCT  LOG 0000023D   product.log
      SYSMENU  LOG 00004000   sysmenu.log
      SHOP     LOG 00000020   shop.log
      HWINFO_S DAT 00004000  HWINFO_S.dat
      HWINFO_N DAT 00004000  HWINFO_N.dat
      CERT     SYS 00000F40  cert.sys
      HWID     SGN 00000100  HWID.sgn
      TWLFON~1 DAT 000D2C40  TWLFontTable.dat
      DEV      KP  000001BE  dev.kp
      TITLE        <DIR>    title
      00030017     <DIR>     00030017 (aka System Menu)
      484E4150     <DIR>      484e4150 (aka Launcher)
      DATA         <DIR>       data
      PRIVATE  SAV 00004000     private.sav
      CONTENT      <DIR>       content
      TITLE    TMD 00000208     title.tmd
      00000002 APP 0019E400     00000002.app
      00030015     <DIR>     00030015 (aka System Base Tools)
      484E4250     <DIR>      484e4250 (aka System Settings)
      DATA         <DIR>       data
      CONTENT      <DIR>       content
      TITLE    TMD 00000208     title.tmd
      00000002 APP 00285C00     00000002.app
      484E4650     <DIR>      484e4650 (aka Nintendo DSi Shop)
      DATA         <DIR>       data
      PRIVATE  SAV 00004000     private.sav
      EC       CFG 00000134     ec.cfg
      CONTENT      <DIR>       content
      00000004 APP 00526400     00000004.app
      TITLE    TMD 00000208     title.tmd
      0003000F     <DIR>     0003000f (aka System Data)
      484E4341     <DIR>      484e4341 (aka Wifi Firmware)
      DATA         <DIR>       data
      CONTENT      <DIR>       content
      TITLE    TMD 00000208     title.tmd
      00000002 APP 00017E60     00000002.app
      484E4841     <DIR>      484e4841 (aka Nintendo DS Cart Whitelist)
      DATA         <DIR>       data
      CONTENT      <DIR>       content
      TITLE    TMD 00000208     title.tmd
      00000001 APP 0004B1D0     00000001.app
      484E4C50     <DIR>      484e4c50 (aka Version Data)
      DATA         <DIR>       data
      CONTENT      <DIR>       content
      00000004 APP 00001B50     00000004.app
      TITLE    TMD 00000208     title.tmd
      00030005     <DIR>     00030005 (aka System Fun Tools)
      484E4441     <DIR>      484e4441 (aka DS Download Play)
      DATA         <DIR>       data
      CONTENT      <DIR>       content
      TITLE    TMD 00000208     title.tmd
      00000001 APP 00069BC0     00000001.app
      484E4541     <DIR>      484e4541 (aka Pictochat)
      DATA         <DIR>       data
      CONTENT      <DIR>       content
      00000000 APP 00074FC0     00000000.app
      TITLE    TMD 00000208     title.tmd
      484E4950     <DIR>      484e4950 (aka Nintendo DSi Camera)
      DATA         <DIR>       data
      PRIVATE  SAV 00080000     private.sav
      CONTENT      <DIR>       content
      TITLE    TMD 00000208     title.tmd
      00000002 APP 00443C00     00000002.app
      484E4A50     <DIR>      484e4a50 (aka Nintendo Zone)
      DATA         <DIR>       data
      PRIVATE  SAV 00100000     private.sav
      CONTENT      <DIR>       content
      00000003 APP 0014D000     00000003.app
      TITLE    TMD 00000208     title.tmd
      484E4B50     <DIR>      484e4b50 (aka Nintendo DSi Sound)
      DATA         <DIR>       data
      PRIVATE  SAV 00080000     private.sav
      CONTENT      <DIR>       content
      00000002 APP 00451000     00000002.app
      TITLE    TMD 00000208     title.tmd
      00030004     <DIR>     00030004 (aka DSiware)
      484E4750     <DIR>      484e4750 (aka Nintendo DSi Browser)
      DATA         <DIR>       data
      PRIVATE  SAV 00200000     private.sav
      CONTENT      <DIR>       content
      00000001 APP 008F1C00     00000001.app
      TITLE    TMD 00000208     title.tmd
      4B475556     <DIR>      4b475556 (aka Flipnote Studio)
      DATA         <DIR>       data
      PUBLIC   SAV 007F0000     public.sav
      CONTENT      <DIR>       content
      00000000 APP 00348400     00000000.app
      TITLE    TMD 00000208     title.tmd
      TICKET       <DIR>    ticket
      00030017     <DIR>     00030017 (aka System Menu)
      484E4150 TIK 000002C4   484e4150.tik (aka Launcher)
      00030015     <DIR>     00030015 (aka System Base Tools)
      484E4250 TIK 000002C4   484e4250.tik (aka System Settings)
      484E4650 TIK 000002C4   484e4650.tik (aka Nintendo DSi Shop)
      0003000F     <DIR>     0003000f (aka System Data)
      484E4341 TIK 000002C4   484e4341.tik (aka Wifi Firmware)
      484E4841 TIK 000002C4   484e4841.tik (aka Nintendo DS Cart Whitelist)
      484E4C50 TIK 000002C4   484e4c50.tik (aka Version Data)
      00030005     <DIR>     00030005 (aka System Fun Tools)
      484E4441 TIK 000002C4   484e4441.tik (aka DS Download Play)
      484E4541 TIK 000002C4   484e4541.tik (aka Pictochat)
      484E4950 TIK 000002C4   484e4950.tik (aka Nintendo DSi Camera)
      484E4A50 TIK 000002C4   484e4a50.tik (aka Nintendo Zone)
      484E4B50 TIK 000002C4   484e4b50.tik (aka Nintendo DSi Sound)
      00030004     <DIR>     00030004 (aka DSiware)
      484E4750 TIK 000002C4   484e4750.tik (aka Nintendo DSi Browser)
      4B414D56 TIK 000002C4   4b414d56.tik (aka Paper Plane)
      4B443956 TIK 000002C4   4b443956.tik (aka Dr. Mario)
      4B475556 TIK 000002C4   4b475556.tik (aka Flipnote Studio)
      4B4D3958 TIK 000002C4   4b4d3958.tik (aka Magic Made Fun: Deep Psyche)
      SHARED1      <DIR>    shared1
      TWLCFG0  DAT 00004000  TWLCFG0.dat
      TWLCFG1  DAT 00004000  TWLCFG1.dat
      SHARED2      <DIR>    shared2
      LAUNCHER     <DIR>     launcher
      WRAP     BIN 00004000   wrap.bin
      0000         00200000  0000
      IMPORT       <DIR>    import
      TMP          <DIR>    tmp
      ES           <DIR>     es
      WRITE        <DIR>      write
      PROGRESS     <DIR>    progress

DSi eMMC Partition 2 (FAT12)

      PHOTO        <DIR>    photo
      PRIVATE      <DIR>     private
      DS           <DIR>      ds
      APP          <DIR>       app
      484E494A     <DIR>        484E494A (aka Nintendo DSi Camera Stuff)
      PIT      BIN 00001F60      pit.bin
      DCIM         <DIR>     DCIM
      100NIN02     <DIR>      100NIN02
      HNI_0008 JPG 0000AB51    HNI_0008.JPG
      HNI_0009 JPG 00009A96    HNI_0009.JPG
      HNI_0010 JPG 0000932B    HNI_0010.JPG
      HNI_0011 JPG 00009CB8    HNI_0011.JPG
      HNI_0012 JPG 00009CA9    HNI_0012.JPG
      HNI_0013 JPG 00009A3B    HNI_0013.JPG

DSi eMMC Partition 3 (unformatted)
There's a small 3rd partition in MBR, but it's left unformatted (the VBR and FAT and everything is left zero-filled). Unknown if there are any cases where this partition is used, and if so: if it's meant to be encrypted or unencrypted. In case it's meant to be encrypted: Observe that the unformatted partition contains UNENCRYPTED zeroes (so trying to "decrypt" those zeroes would produce random garbage data).
SD Card
DSiware (including Browser and Flipnote) can be exported to SD Card (via System Menu, Data Managment).
Camera Photos and Frames can be exported (via Nintendo DSi Camera, Options, Copy) (Frames are some sort of gaudi-masks that can be used (and created) via one of the Camera special effect features; the mask uses YELLOW as transparent color). As on eMMC storage, all photos from internal camera are mirrored horizontally.

      PRIVATE      <DIR>    private
      DS           <DIR>     ds
      TITLE        <DIR>      title                                     ;\
      484E4750 BIN 9.180K      484E4750.bin (aka Nintendo DSi Browser)  ; dsiware
      4B475556 BIN 11.510K     4B475556.bin (aka Flipnote Studio)       ; games
      HNB_     LST 2K          HNB_.lst     (content: "VUGKPGNH")       ;/
      APP          <DIR>      app
      484E494A     <DIR>       484E494A (aka Nintendo DSi Camera Stuff) ;\
      PIT      BIN 47K          pit.bin                                 ; camera
      DCIM         <DIR>        DCIM                                    ; frames
      100NIN02     <DIR>         100NIN02                               ;
      HNI_0001 JPG 45K            HNI_0001.JPG  ;-frame/mask            ;/
      4B475556     <DIR>       4B475556 (aka Flipnote Studio Stuff)     ;\
      RECENT10 PLS 4K           recent10.pls                            ;
      MARK0    PLS 8K           mark0.pls                               ; flipnote
      MARK1    PLS 8K           mark1.pls                               ; stuff
      MARK2    PLS 8K           mark2.pls                               ;
      MARK3    PLS 8K           mark3.pls                               ;
      001          <DIR>        001                                     ;
      DIRMEMO2 LST 157K         dirmemo2.lst                            ;
      F08243~1 PPM 467K         F08243_0E5E2296197E5_000.ppm            ;/
      DCIM         <DIR>    DCIM
      101NIN02     <DIR>     101NIN02           ;<-- can be 100NIN02 thru 999NIN02
      HNI_0001 JPG 43K        HNI_0001.JPG      ;\dsi camera photos
      HNI_0002 JPG 17K        HNI_0002.JPG      ; (names are numbered differently
      HNI_0003 JPG 39K        HNI_0003.JPG      ;/as on eMMC where they came from)

Reportedly, the "Nintendo DSi Sound" application can also access audio files in AAC format, saved in any folders on SD Card.
Aside from DSi-related files, the SD Card can also contain whatever files from other computers.
Blocks
The System Menu, Data Management feature is referring to filesizes & free space in "Blocks" (aka 128Kbytes units, aka 1Mbit units).

DSi SD/MMC Summary of SD/MMC Files/Folders

File/folder names
The DSi is using weird numeric strings as file/folder names:

      000000vv Title Version (lowercase hex32bit) from tmd[1E4h] as carthdr[1Eh]
      4ggggggg Title ID Gamecode (hex) as carthdr[230h..233h]
      000300tt Title ID Filetype (hex) as carthdr[234h..237h]
      HNI_nnnn Camera photo/frame files (nnnn = 0001..0100 decimal)
      nnnNIN02 Camera photo/frame folders (nnn = 100..999 decimal)

The "000300tt" can be:

      00030000 ROM Cartridges (as so for ROMs, doesn't appear in SD/MMC files)
      00030004 DSiware (browser, flipnote, and games) (if any installed)
      00030005 System Fun Tools (camera, sound, zone, pictochat, ds download play)
      0003000f System Data (non-executable, without carthdr)
      00030015 System Base Tools (system settings, dsi shop, 3ds transfer tool)
      00030017 System Menu (launcher)

The "4ggggggg" can be (last two digits are region(s), or "41" for all regions):

      484e41gg System Menu (Launcher)
      484e42gg System Settings
      484e4341 Wifi Firmware (non-executable datafile) (all regions)
      484e4441 DS Download Play (all regions)
      484e4541 Pictochat (all regions) (no update available)
      484e46gg Nintendo DSi Shop
      484e47gg Nintendo DSi Browser
      484e4841 Nintendo DS Cart Whitelist (non-executable datafile) (all regions)
      484e49gg Nintendo DSi Camera
      484e4agg Nintendo Zone (doesn't exist in Korea)
      484e4bgg Nintendo DSi Sound
      484e4cgg Version Data (non-executable datafile)
      484e4fgg Nintendo 3DS Transfer Tool
      484E494A Nintendo DSi Camera Data (uppercase) ("japan") (aka all regions)
      4b44474a Dokodemo Wii no Ma (japan only)
      4b4755gg Flipnote Studio (doesn't exist in Korea/China)
      42383841 DS Internet settings (a new DSi tool on 3DS consoles)
      4bgggggg DSiware games... (whatever games you have purchased, if any)

These files can be stored in Internal eMMC, or on external SD card, and can be downloaded from Nintendo's server (when buying games, or updating system files).
DSi Internal eMMC
Internal eMMC can contain System files and any purchased DSiware games:

      FAT16:\ticket\000300tt\4ggggggg.tik (encrypted)      ;ticket (708 bytes)
      FAT16:\title\000300tt\4ggggggg\content\title.tmd     ;tmd (520 bytes)
      FAT16:\title\000300tt\4ggggggg\content\000000vv.app  ;executable (decrypted)
      FAT16:\title\000300tt\4ggggggg\data\public.sav       ;size as carthdr[238h]
      FAT16:\title\000300tt\4ggggggg\data\private.sav      ;size as carthdr[23Ch]
      FAT16:\title\000300tt\4ggggggg\data\ec.cfg           ;dsi shop only
      FAT16:\title\000300tt\4ggggggg\data\banner.sav       ;if carthdr[1BFh].bit2=1

Note that some of the above files are containing their own virtual filesystem inside of the eMMC's FAT16 filesystem (NitroROM filesystems in "000000vv.app" files, and FAT12 filesystems in "public.sav" and "private.sav" files).
The System tools (menu, settings, and shop) are also storing further data on FAT16 (outside of the ticket and title folders):

      FAT16:\shared1\TWLCFG0.dat            ;16K
      FAT16:\shared1\TWLCFG1.dat            ;16K
      FAT16:\shared2\launcher\wrap.bin      ;16K
      FAT16:\shared2\0000                   ;2048K (sound recorder)
      FAT16:\sys\log\product.log            ;573 bytes
      FAT16:\sys\log\sysmenu.log            ;16K
      FAT16:\sys\log\shop.log               ;32 bytes
      FAT16:\sys\HWINFO_S.dat               ;16K
      FAT16:\sys\HWINFO_N.dat               ;16K
      FAT16:\sys\cert.sys                   ;3904 bytes (or 2560 bytes)
      FAT16:\sys\HWID.sgn                   ;256 bytes (unknown purpose/content)
      FAT16:\sys\TWLFontTable.dat           ;843.1K (D2C40h bytes) (compressed)
      FAT16:\sys\dev.kp                     ;446 bytes (encrypted)
      FAT16:\import\                        ;empty folder
      FAT16:\progress\                      ;empty folder
      FAT16:\tmp\es\write\                  ;empty folder

The Camera is storing further data on the eMMC FAT12 partition:

      FAT12:\photo\DCIM\100NIN02\HNI_nnnn.JPG                        ;camera photos
      FAT12:\photo\private\ds\app\484E494A\pit.bin                   ;camera info
      FAT12:\photo\private\ds\app\484E494A\DCIM\100NIN02\HNI_nnnn.JPG;camera frames

And, there's a small 3rd eMMC partition in MBR, but it's left unformatted (the VBR and FAT and everything is left zero-filled).
DSi External SD Card
DSiware games (and browser and flipnote) can be copied to SD card (via System Menu, Data Managment) (however, the DSi doesn't seem to allow to execute files on SD card, so they can be used only if they are copied back to the DSi):

      SD:\private\ds\title\4GGGGGGG.bin    ;executable/data in one file (encrypted)
      SD:\private\ds\title\HNB_.lst        ;list of gamecodes

Camera data can be copied to SD card (via Nintendo DSi Camera, Options, Copy):

      SD:\DCIM\nnnNIN02\HNI_nnnn.JPG                            ;camera photos
      SD:\private\ds\app\484E494A\pit.bin                       ;camera info
      SD:\private\ds\app\484E494A\DCIM\nnnNIN02\HNI_nnnn.JPG    ;camera frames

Flipnote "movies" can be also saved on SD card:

      SD:\private\ds\app\4B4755GG\recent10.pls     ;Recently saved path/filenames
      SD:\private\ds\app\4B4755GG\mark0.pls        ;Heart sticker path/filenames
      SD:\private\ds\app\4B4755GG\mark1.pls        ;Crown sticker path/filenames
      SD:\private\ds\app\4B4755GG\mark2.pls        ;Music sticker path/filenames
      SD:\private\ds\app\4B4755GG\mark3.pls        ;Skull sticker path/filenames
      SD:\private\ds\app\4B4755GG\001\dirmemo2.lst ;List of all files in folder
      SD:\private\ds\app\4B4755GG\001\XNNNNN_NNNNNNNNNNNNN_NNN.ppm          ;normal
      SD:\private\ds\app\4B4755GG\YYYYMMDD\NNN\XNNNNN_NNNNNNNNNNNNN_NNN.ppm ;backup
      SD:\private\ds\app\4B4755GG\gif\XNNNNN_NNNNNNNNNNNNN_NNN.gif          ;gif

The Nintendo DSi Sound utility can read .AAC (and .M4A) files from SD card (though it doesn't seem to allow to save your own recordings to SD card?). There appears to be no special folder location, ie. the AAC/M4A files can be anywhere:

      SD:\...\*.aac
      SD:\...\*.m4a

DSi Shop and System Update Download URLs

      http://nus.cdn.t.shop.nintendowifi.net/ccs/download/000300tt4ggggggg/tmd
      http://nus.cdn.t.shop.nintendowifi.net/ccs/download/000300tt4ggggggg/cetk
      http://nus.cdn.t.shop.nintendowifi.net/ccs/download/000300tt4ggggggg/000000vv

The "cetk" file contains the encrypted ticket. The "cetk" file is available only for freeware downloads (eg. system updates). Commercial DSi Shop titles can be downloaded the same way, except that the ticket must be somehow purchased/downloaded separetely.
Nintendo does keep hosting older "00000vv" versions (except, the original version, "00000000" isn't available in all cases; namely if the title was pre-installed on all DSi's then it would be pointless to provide it as update).
NUS Downloader Notation
The homebrew NUS Downloader utility for PCs comes up with its own renaming scheme:

      d:\...\TITLES\000300tt4ggggggg\ddd\000000vv      ;executable (encrypted)
      d:\...\TITLES\000300tt4ggggggg\ddd\000000vv.APP  ;executable (decrypted)
      d:\...\TITLES\000300tt4ggggggg\ddd\CETK          ;cetk (2468 bytes)
      d:\...\TITLES\000300tt4ggggggg\ddd\TMD           ;tmd (520 bytes)

Whereas, "ddd" is same as "000000vv" multiplied by 256 decimal (which is nonsense and redundant). The decrypted ".APP" file is generated only if the "common key" is found in 16-byte file "dsikey.bin".

DSi SD/MMC Images

Filesystem Viewer
no$gba debug version is allowing to view the filesystem tree from encrypted eMMC images (via menubar: Window, Filesystem), the filesystem viewer is also able to export single files from eMMC and SD images (by double-clicking separate files).

      XXX    currently, the double-clicked file will be saved as "TEMP.TMP",
      XXX    in no$gba folder (there is no "Save as" dialog yet)

Emulation
No$gba emulates read/write-accesses to eMMC images.
Another idea for future would be using files & folders on the PC filesystem instead of a single image file (that might be easier to deal with in some cases, but for the reverse-engineering stage it's better to stick with original authentic images).
Encrypted eMMC Images
no$gba can emulate up to 12 consoles simultaneously, and expects the eMMC images having following filename(s), in no$gba folder:

      DSi-#.mmc             ;eMMC for machine 1..12 (# = 1..C hex)

the eMMC images are encrypted with per-console keys, so decryption won't work without knowing the console ID values. no$gba expects that info to be stored in a 40h-byte Footer at the end of the file:

      00000000h .. Encrypted eMMC image (usually 240Mbyte for DSi)
      0F000000h 16 Footer ID      ("DSi eMMC CID/CPU")
      0F000010h 16 eMMC CID       (dd ss ss ss ss 03 4D 30 30 46 50 41 00 00 15 00)
      0F000020h 8  CPU/Console ID (nn n1 nn nn nn nn xn 08)
      0F000028h 24 Reserved       (zerofilled)

Alternately, the "footer" can be stored in the zerofilled area at eMMC offset 000FF800h..000FF83Fh (using that area, the data can be kept in place even when using other tools; that were getting confused by the data appended at end of file).
SD Card Images
no$gba supports SD Card images in similar fashion as above eMMC images, but without needing any footer since there's encryption on SD cards. The image should contain a pre-formatted MBR and FAT (as real SD cards do).

      DSi-#.sd              ;SD Card for machine 1..12 (# = 1..C hex)

note: no$gba does currently support only 128MB SDSC images (the CID, CSD, OCR, SCR, SSR registers are hardcoded for images with 125698048 byte size), there is a .zip file with an empty pre-formatted SD image in the no$gba package (if you want to use that image: unzip it to the no$gba folder).
Dumping eMMC Images
DSiware exploits like sudokuhax are allowing to access SD/MMC hardware (so one could simply copy all eMMC sectors to a file on SD Card).
Unfortunately, most/other exploits don't have SD/MMC access, so dumping would work only when the eMMC chip to a SD/MMC card reader. For details, see:
AUX DSi SD/MMC Pin-Outs
For obtaining the Console IDs, see:
DSi Console IDs

DSi SD/MMC DSiware Files on Internal eMMC Storage

DSiware games (downloaded from DSi Shop), and pre-installed System Tools are consisting of following files:
FAT16:\title\000300tt\4ggggggg\content\000000vv.app ;executable (decrypted)
Contains the executable, with same header as used in Cartridge ROM images, and usually with a NitroROM File System (ie. a second virtual filesystem inside of the FAT16 filesystem).
DSi Cartridge Header
DS Cartridge NitroROM and NitroARC File Systems
Note: There are also three non-executable ".app" files without cartridge headers (Wifi Firmware, Version Data, and DS Cart Whitelist).
FAT16:\title\000300tt\4ggggggg\data\public.sav ;size as carthdr[238h]
FAT16:\title\000300tt\4ggggggg\data\private.sav ;size as carthdr[23Ch]
These files can contain whatever save data. The .sav files are usually containing a FAT12 with its own VBR, FAT, and Directories (so they use some virtual FAT12 inside of the real FAT16).
When exporting a game to SD Card (via System Settings, Data Managment), then public.sav (eg. used by Flipnote) will be included in the exported image, whilst private.sav (eg. used by DSi Browser) won't be included.
FAT16:\title\000300tt\4ggggggg\data\ec.cfg ;dsi shop only
Whatever extra file, encrypted, 134h bytes, used by DSi Shop only.
FAT16:\title\000300tt\4ggggggg\data\banner.sav ;if carthdr[1BFh].bit2=1
Custom icon, used by some games to indicate the game progress. Format is similar as Icon/Title, but containing only animated icon data (without title). For details, see:
DS Cartridge Icon/Title
FAT16:\title\000300tt\4ggggggg\content\title.tmd ;tmd (520 bytes)
FAT16:\ticket\000300tt\4ggggggg.tik (encrypted) ;ticket (708 bytes)
FAT16:\ticket\000300tt\00000000.tik (encrypted) ;multi-tik? (N*708 bytes?)
These files do contain title metadata (.tmd) and tickets (.tik).
DSi SD/MMC DSiware Tickets and Title metadata
The .tik files are encrypted with ES Block Encryption (using same key X/Y as for dev.kp):

      KEY_X[00h..03h] = 4E00004Ah                           ;\
      KEY_X[04h..07h] = 4A00004Eh                           ; same as for Tad
      KEY_X[08h..0Bh] = Port[4004D00h+4] xor C80C4B72h      ;
      KEY_X[0Ch..0Fh] = Port[4004D00h+0]                    ;/
      KEY_Y[00h..0Fh] = Constant (E5,CC,5A,8B,...)  ;from ARM7BIOS

DSi ES Block Encryption
Caution: There are some ways to modify .tmd files, but that can cause the whole title to be deleted when starting one of the following three tools:

      Data Management (in System Settings), DSi Shop, and 3DS transfer tool

These tools will delete the titles "content" folder (with .app and .tmd files) and the "data" folder (with .sav files). As a workaroung: Set read-only attribute for .tmd and .app files (the deletion aborts once when hitting a read-only file; with the files being processed as ordered in the directory).
Note: Tickets are kept stored in eMMC even after deleting titles (that's allowing to redownload the titles for free; at least that's been the case when the DSi shop was still online).
Below "wrap.bin" and "menusave.dat" files are containing lists of installed titles, however, it isn't neccessary to edit those files when manually installing .tmd/.app/.tik files.
FAT16:\shared2\launcher\wrap.bin (16Kbytes)
Contains a list of installed DSiware Title IDs (in no specific order).

      0000h 14h   SHA1 on entries [014h..03Fh]
      0014h 14h   SHA1 on entries [040h..177h]
      0028h 4     ID ("APWR") (aka 'WRAP' with mis-ordered letters)
      002Ch 4     Size of entries at [040h..177h] (00000138h, aka 39*8)
      0030h 10h   Zerofilled
      0040h 138h  Space for 39 Title IDs (as at cart[230h]) (8x00h=unused entry)
      0178h 3E88h Unknown (looks like random/garbage, or encrypted junk)

FAT16:\title\00030017\484e41gg\data\private.sav:\menusave.dat (System Menu)
This private.sav file contains a 4000h-byte FAT12 image. The FAT12 contains only one file: menusave.dat (154h bytes), containing a list of Title IDs (and their sort-order how they are arranged in System Menu; users can drag the icons to rearrange their ordering):

      0000h 4     ID ("TSSV")
      0004h 4     Zerofilled (used somehow, can be nonzero?)
      0008h 2     CRC16 on [000h..0153h], initial value 5356h, assume [008h]=0000h
      000Ah 6     Zerofilled
      0010h 39x8  Title IDs (gg,gg,gg,gg,tt,00,03,00) (0=NDS CartSlot or Unused)
      0148h 8     Zerofilled
      0150h 4     Index of NDS CartSlot Entry (0..39)

The current selection isn't stored in this file (instead, the Title ID of the most recently selected title is stored in the TWLCFGn.dat files).
Note that the "Nintendo Zone" utility isn't included in this list (even though it's present in title & ticket folders, and listed in wrap.bin).
The System Menu works even if data\private.sav doesn't exist (however, the sort-order is stored only if data\private.sav does exist).

DSi SD/MMC DSiware Files on External SD Card (.bin aka Tad Files)

The DSi can export applications from NAND to SD (via System Settings --> Data Managment). The ".bin" files created on SD are using the "Tad file structure", and alongsides, there's a "HNB_.lst" file containing a list of game codes.
SD:\private\ds\title\HNB_.lst (list of gamecodes) (1208 bytes)

      000h 1200  List of 300 gamecodes, spelled backwards (or zero = unused entry)
      4B0h 1     Language (0=Jap, 1=Eng, 2=Fre, 3=Ger, 4=Ita, 5=Spa, 6=Chi, 7=Kor?)
      4B1h 3     Zero
      4B4h 2     CRC16 on entries [000h..4B3h] (with initial value FFFFh)
      4B6h 2     Zero

For example, "VUGK" in HNB_.lst would indicate gamecode KGUV aka "Flipnote Studio" for EUR/AUS regions. And the corresponding SD Card file would be "SD:\private\ds\title\4B475556.bin" (with the 4-letter gamecode encoded as 8-digit uppercase HEX number). The full 16-digit on eMMC storage would be "00030004\4b475556" (in lowercase, and with the "00030004" implied for the DSiWare folder; files from system folders cannot be exported to SD Card).
The Language byte reflects the System Settings's language selection at time when the HNB_.lst was created or modified (unknown why that info is stored in the file).
SD:\private\ds\title\4GGGGGGG.bin (encrypted executable/data in one file)

      Offset   Size       Key  Description
      000000h  4000h+20h  FIX  Icon/Title
      004020h  B4h+20h    FIX  Header
      0040F4h  440h+20h   FIX  Cert (certificates/hashes)
      004554h  208h+20h   VAR  title.tmd (usually 208h bytes; but could be bigger)
      00477Ch  size+N*20h VAR  000000vv.app
      ...      0          ?    seven N/A parts (unknown if/when they are used)
      ...      size+N*20h FIX  public.sav  (if any)
      ...      ?          ?    banner.sav  (if any)

ES Block Encryption is used to encrypt the header block, cert block, and the 11 content parts. Each are their own seperate ES blocks.
DSi ES Block Encryption
Some of the above blocks use fixed keys (FIX):

      KEY_X[00h..0Fh] = Constant ("Nintendo DS",...)
      KEY_Y[00h..0Fh] = Constant (66,82,32,04,...)  ;from ARM7BIOS
      since above X/Y are constant, that gives a fixed normal key:
      KEY[00h..0Fh]   = Constant (3D,A3,EA,33,...)  ;as used in "dsi srl extract"

Other blocks use variable per-console keys (VAR):

      KEY_X[00h..03h] = 4E00004Ah                           ;\
      KEY_X[04h..07h] = 4A00004Eh                           ; same as for dev.kp
      KEY_X[08h..0Bh] = Port[4004D00h+4] xor C80C4B72h      ;
      KEY_X[0Ch..0Fh] = Port[4004D00h+0]                    ;/
      KEY_Y[00h..0Fh] = Constant (CC,FC,A7,03,...)  ;from ARM7BIOS

Without knowing the console-specifc Port[4004D00h] value, the data could be decrypted only by the DSi console that has originally exported the file to SD card.
However, Nintendo has somehow (maybe accidently) managed to store the Port[4004D00h] value as 16-digit ASCII string in the "TW cert"; which can be decrypted right from the SD card file (as done by the homebrew "dsi srl extract" utility).
Decrypted Icon/Title (at 0000h, size 4000h)

      0000h 23C0h  Icon/Title (usually 23C0h bytes) ;see carthdr[068h,208h]
      23C0h 1C40h  Zerofilled (padding to get 4000h byte size)

Decrypted Header block (at 4020h, size B4h)

      000h  4      Fixed ID "4ANT" (aka TNA4, spelled backwards)
      004h  2      Maker Code, spelled backwards ("10"=Nintendo) ;carthdr[010h]
      006h  1      Zero
      007h  1      Title version (vv)                            ;carthdr[01Eh]
      008h  6      DSi MAC Address, spelled backwards            ;wifi_flash[036h]
      00Eh  2      Zero
      010h  16     Some console ID from HWINFO_N.dat             ;datfile[8Ch..9Bh]
      020h  8      Title ID (gg gg gg gg 04 00 03 00)            ;carthdr[230h]
      028h  4      Size of title.tmd    (usually 208h+20h)
      02Ch  4      Size of 000000vv.app (size+N*20h)             ;carthdr[210h]
      030h  4*7    Size of seven N/A parts (0)
      04Ch  4      Size of public.sav   (size+N*20h)             ;carthdr[238h]
      050h  4      Size of banner.sav?  (usually 0)       ;carthdr[1BFh].bit2=1
      054h  4*8    List of eight Content IDs in same order as title.tmd
      074h  3Eh    Reserved section per tmds, uh? (mostly zero, plus garbage?)
      0B2h  2      Unknown (zero)

Decrypted Cert block (at 40F4h, size 460h)

      000h  20     SHA1 of Icon/Title
      014h  20     SHA1 of TNA4
      028h  20     SHA1 of title.tmd
      03Ch  20     SHA1 of 000000vv.app
      040h  20*7   SHA1 of seven N/A parts (unused, can be whatever garbage)
      0DCh  20     SHA1 of public.sav
      0F0h  20     SHA1 of banner.sav
      104h  3Ch    ECC signature of [000h..103h] with AP cert
      140h  180h   AP cert, signed by TW cert
      2C0h  180h   TW cert, specific to a console (see dev.kp)

More in depth, the above two cert's look as so:

      140h 4    Signature Type (00,01,00,02) (ECC, sect233r1, non-RSA)  ;\
      144h 3Ch  Signature Hex numbers... across... below?               ; AP cert
      180h 40h  Signature padding/alignment (zerofilled)                ; 180h-byte
      1C0h 40h  Signature Name "Root-CA..-MS..-TW..-08..", 00h-padded   ;
                "Root-CA00000001-MS00000008-TWxxxxxxxx-08nnnnnnnnnnn1nn";
      200h 4    Key Type (00,00,00,02)       (ECC, sect233r1, non-RSA)  ;
      204h 40h  Key Name "AP00030015484e42gg", 00h-padded ;sys.settings ;
      244h 4    Key Random/time/type/flags/chksum?   ;<-- ZERO here     ;
      248h 3Ch  Key Public ECC Key (point X,Y) (random/per game?)       ;
      284h 3Ch  Key padding/alignment (zerofilled)                      ;/
      2C0h 4    Signature Type (00,01,00,02) (ECC, sect233r1, non-RSA)  ;\
      2C4h 3Ch  Signature Hex numbers... across... below?               ; TW cert
      300h 40h  Signature padding/alignment (zerofilled)                ; 180h-byte
      340h 40h  Signature Name "Root-CA00000001-MS00000008", 00h-padded ; (same as
      380h 4    Key Type (00,00,00,02)       (ECC, sect233r1, non-RSA)  ; dev.kp,
      384h 40h  Key Name "TWxxxxxxxx-08nnnnnnnnnnn1nn", 00h-padded      ; excluding
      3C4h 4    Key Random/time/type/flags/chksum?                      ; private
      3C8h 3Ch  Key Public ECC Key (point X,Y)                          ; key)
      404h 3Ch  Key padding/alignment (zerofilled)                      ;/

Much like the Wii, the DSi carries with it a private ECC key that it can use to sign things, and a certificate signed by Nintendo that attests to the fact that the public ECC key belongs to a genuine DSi.

DSi SD/MMC DSiware Files from Nintendo's Server

http://nus.cdn.t.shop.nintendowifi.net/ccs/download/000300tt4ggggggg/000000vv
The "000000vv" file contains the ".app" file (in encrypted form).

      Server:  "000000vv"      (AES-CBC encrypted, raw)
      eMMC:    "000000vv.app"  (decrypted, raw)
      SD Card: "GGGGGGGG.bin"  (ES-block encrypted, with extra data)

First, the encrypted Title Key must be decrypted (via AES-CBC):

      KEY[00h..0Fh] = Common Key (AF,1B,F5,16,...)        ;from ARM7BIOS
      IV[00h..07h]  = Title ID (00,03,00,tt,gg,gg,gg,gg)  ;from tik/cetk[1DCh]
      IV[08h..0Fh]  = Zerofilled                          ;padding
      Input: Encrypted Title Key                          ;from tik/cetk[1BFh]
      Output: Decrypted Title Key                         ;for use in next step

Then, the actual executable/file can be decrypted (also via AES-CBC):

      KEY[00h..0Fh] = Decrypted Title Key                 ;from above step
      IV[00h..01h]  = Usually Zero (or "Index" from tmd?) ;from tmd[1E8h+N*24h] ?
      IV[02h..0Fh]  = Zerofilled                          ;padding
      Input: Encrypted file "000000vv"                    ;from http download
      Output: Decrypted file "000000vv.app"               ;saved on eMMC

The above decryption steps do require a big-endian AES-CBC software implementation (the DSi hardware supports only little-endian, and it supports only AES-CTR and AES-CCM, and, especially, it supports only the "encrypt" key schedule, whilst AES-CBC would require a different "decrypt" key schedule).
http://nus.cdn.t.shop.nintendowifi.net/ccs/download/000300tt4ggggggg/cetk
http://nus.cdn.t.shop.nintendowifi.net/ccs/download/000300tt4ggggggg/tmd
http://nus.cdn.t.shop.nintendowifi.net/ccs/download/000300tt4ggggggg/tmd.nn
These files do contain tickets ("cetk"), and title metadata ("tmd" for newest version, plus "tmd.nn" for older versions; with nn=0,1,256,257,512 and the like).
DSi SD/MMC DSiware Tickets and Title metadata
The "cetk" file is available only for free system updates (not for titles sold commercially in DSi Shop).
Downloading
The files can be downloaded with normal web browsers. The homebrew "NUS Downloader" utility is also allowing to download those files (and to decrypt them, provided that the "cetk" is available).
For free system updates, tickets can be downloaded as "cetk" files. For titles sold commercially in DSi ship, tickets must be purchased somehow differently.
For example, the updates for DSi System Settings (EUR) can be downloaded from:

      http://nus.cdn.t.shop.nintendowifi.net/ccs/download/00030015484e4250/tmd
      http://nus.cdn.t.shop.nintendowifi.net/ccs/download/00030015484e4250/cetk
      http://nus.cdn.t.shop.nintendowifi.net/ccs/download/00030015484e4250/00000002
      http://nus.cdn.t.shop.nintendowifi.net/ccs/download/00030015484e4250/00000003

The tmd and cetk files are unencrypted. The 00000002 and 00000003 files are encrypted executables (containing System Settings v2 and v3).
Older Versions
Nintendo is usually keeping older "000000vv" files on their server, so one could still download those older versions.
The oldest/original version would be usually "00000000", however, in case of system files that are pre-installed on all consoles, only later versions are available as updates (ie. starting with "00000001", or for some reason, with "00000002", in case of system settings).
The tmd/cetk files are available only for the newest version (meaning that some cosmetic values like title size & title version are adjusted for the newest version; the cetk's AES-CBC key usually doesn't change for updates, so older versions can be still decrypted with newer cetk's).
Older versions are usually deleted on internal eMMC storage, so only the "000000vv.app" file exists.

DSi SD/MMC DSiware Tickets and Title metadata

Below describes the "raw" ticket+tmd formats. For more info on the data being stored/encrypted in various locations, see these chapters:
DSi SD/MMC DSiware Files on Internal eMMC Storage
DSi SD/MMC DSiware Files on External SD Card (.bin aka Tad Files)
DSi SD/MMC DSiware Files from Nintendo's Server
Ticket (cetk aka .tik)
Tickets exist as "cetk" files (as found on Nintendo's server), and as ".tik" files (as found in nand/ticket folder):

      Server:  "cetk"         unencrypted, 2468 bytes (2A4h+700h), tik+certificate
      eMMC:    "gggggggg.tik" encrypted,   708 bytes  (2A4h+20h),  tik+es_block
      SD Card: N/A            N/A, tickets aren't exported to SD card

Tickets are used for decrypting downloads from DSi shop. They are essentially containing a 16-byte AES-CBC decryption key, plus signatures and some other stuff.

      000h  4    Signature Type (00h,01h,00h,01h) (100h-byte RSA)
      004h  100h Signature RSA-OpenPGP-SHA1 across 140h..2A3h
      104h  3Ch  Signature padding/alignment (zerofilled)
      140h  40h  Signature Name "Root-CA00000001-XS00000006", 00h-padded
      180h  3Ch  ECDH data for one-time installation keys?   ;zero for free tik's
      1BCh  1    Zero (3DS: Ticket Version=1)
      1BDh  1    Zero (3DS: CaCrl Version=0)
      1BEh  1    Zero (3DS: SignerCrl Version=0)
      1BFh  10h  Encrypted AES-CBC Title Key
      1CFh  1    Zero
      1D0h  8    Ticket ID  (00,03,xx,xx,xx,xx,xx,xx) ?
      1D8h  4    Console ID (see dev.kp "TWxxxxxxxx", zero for free system updates)
      1DCh  8    Title ID       (00,03,00,17,"HNAP")                   ;cart[230h]
      1E4h  2    Zero (Wii: mostly FFFFh)
      1E6h  2    Title Version (vv,00) (LITTLE-ENDIAN!?)       ;NEWEST ;cart[01Eh]
      1E8h  4    Zero (Wii: Permitted Titles Mask)
      1ECh  4    Zero (Wii: Permit mask)
      1F0h  1    Zero (Wii: Allow Title Export using PRNG key, 0=No, 1=Yes)
      1F1h  1    Zero (Wii: Common Key Index, 0=Normal, 1=Korea) (DSi: Always 0)
      1F2h  2Ah  Zero
      21Ch  4    Zero (3DS: eShop Account ID?)
      220h  1    Zero
      221h  1    Unknown (01h) (Wii: Unknown, 00h=Non-VC, 01h=VC=VirtualConsole?)
      222h  20h  FFh-filled (Wii: Content access permissions, 1 bit per content)
      242h  20h  00h-filled (Wii: Content access permissions, 1 bit per content)
      262h  2    Zero
      264h  4    Zero   ;Wii: Time Limit Enable  (0=Disable, 1=Enable)
      268h  4    Zero   ;Wii: Time Limit Seconds (uh, seconds since/till when?)
      26Ch  38h  Zero   ;Wii: Seven more Time Limits (Enable, Seconds)
      2A4h  700h Certificates (see below) (only in "cetk", not in ".tik)

The Launcher checks some of the permission entries, but it doesn't check RSA for tickets, so one can create own/dummy tickets. The Console ID and Title ID might be also unchecked, so one could possibly simply copy/rename existing tickets (from the same console), or decrypt/copy/re-encrypt tickets (from other consoles).
Note: It seems to be possible to store multiple tickets in one .tik file (in that case each ticket is separately encrypted in 2A4h+20h bytes).
Title metadata (tmd aka .tmd)
Title metadata exists as "tmd" file (as found on Nintendo's server), and as ".tmd" file (as found in eMMC title folders), and it's also included in ".bin" files (in files exported to SD cards):

      Server:  "tmd"          unencrypted, 2312 bytes (208h+700h), tmd+certificate
      Server:  "tmd.nn"       as above, OLDER tmd versions (nn=0,1,256,257,512,etc)
      eMMC:    "title.tmd"    unencrypted, 520 bytes  (208h+0),    tmd
      SD Card: "GGGGGGGG.bin" encrypted, huge file, contains .app+tmd+sav files

Title metadata contains signatures and other useless stuff. One possibly useful feature is that it allows to define more than one "content" per title, however, that feature appears to be only used on Wii. DSi titles are usually having only one content (the ".app" file).

      000h        4    Signature Type (00h,01h,00h,01h) (100h-byte RSA)
      004h        100h Signature RSA-OpenPGP-SHA1 across 140h..207h
      104h        3Ch  Signature padding/alignment (zerofilled)
      140h        40h  Signature Name "Root-CA00000001-CP00000007", 00h-padded
      180h        1    TMD Version           (00h) (unlike 3DS)
      181h        1    ca_crl_version        (00h)
      182h        1    signer_crl_version    (00h)
      183h        1    Zero       (padding/align 4h)
      184h        8    System Version (0)
      18Ch        8    Title ID       (00,03,00,17,"HNAP")             ;cart[230h]
      194h        4    Title Type     (0)
      198h        2    Group ID       (eg. "01"=Nintendo)              ;cart[010h]
      19Ah        4    SD/MMC "public.sav" filesize in bytes  (0=none) ;cart[238h]
      19Eh        4    SD/MMC "private.sav" filesize in bytes (0=none) ;cart[23Ch]
      1A2h        4    Zero
      1A6h        1    Zero (3DS: SRL Flag)
      1A7h        3    Zero
      1AAh        10h  Parental Control Age Ratings                    ;cart[2F0h]
      1BAh        1Eh  Zerofilled
      1D8h        4    Access rights (0)
      1DCh        2    Title Version (vv,00) (LITTLE-ENDIAN!?) ;NEWEST ;cart[01Eh]
      1DEh        2    Number of contents (at 1E4h and up) (usually 00h,01h)
      1E0h        2    boot content index (0)
      1E2h        2    Zerofilled (padding/align 4h)
      1E4h+N*24h  4    Content ID    (00,00,00,vv) ;lowercase/hex ;"0000000vv.app"
      1E8h+N*24h  2    Content Index (00,00)
      1EAh+N*24h  2    Content Type  (00,01)  ;aka DSi .app
      1ECh+N*24h  8    Content Size  (00,00,00,00,00,19,E4,00) ;NEWEST ;cart[210h]
      1F4h+N*24h  14h  Content SHA1  (on decrypted ".app" file);NEWEST
      208h+..     700h Certificates (see below) (only in "tmd", not in ".tmd)

The Launcher does verify the .tmd's RSA signature, and uses the Title/Content IDs to create the path/filename for the .app file. The Version, Size, SHA1 entries are not verified, so one could use any .tmd version with any .app version (when renaming the .app to match the .tmd's Content ID, but that'd be a messy solution, and it's better to use the correct .tmd per .app).
Note: title.tmd is usually/always 208h bytes (one content), max permitted size is 49E4h (200h contents), a larger filesize can crash the firmware (used by Unlaunch.dsi exploit).
Certificates (at end of "cetk" and "tmd) (not in ".tik" or ".tmd)

      cert cetk tmd  siz  content
      000h 2A4h 208h 4    Signature Type (00h,01h,00h,01h)             ;\
      004h 2A8h 20Ch 100h Signature                                    ;
      104h 3A8h 30Ch 3Ch  Signature padding/alignment (zerofilled)     ;
      140h 3E4h 348h 40h  Signature Name "Root-CA00000001", 00h-padded ; 300h bytes
      180h 424h 388h 4    Key Type (00,00,00,01) (100h-byte RSA)       ;
      184h 428h 38Ch 40h  Key Name "XS00000006", 00h-padded            ;
      1C4h 468h 3CCh 4    Key Random/time/type/flags/chksum?           ;
      1C8h 46Ch 3D0h 100h Key Public RSA Key                           ;
      2C8h 56Ch 4D0h 4    Key Public RSA Exponent? (00,01,00,01)       ;
      2CCh 570h 4D4h 34h  Key padding/alignment (zerofilled)           ;/
      300h 5A4h 508h 4    Signature Type (00h,01h,00h,00h)             ;\
      304h 5A8h 50Ch 200h Signature                                    ;
      504h 7A8h 70Ch 3Ch  Signature padding/alignment (zerofilled)     ;
      540h 7E4h 748h 40h  Signature Name "Root" (padded with 00h)      ; 400h bytes
      580h 824h 788h 4    Key Type (00,00,00,01) (100h-byte RSA)       ;
      584h 828h 78Ch 40h  Key Name "CA00000001", 00h-padded            ;
      5C4h 868h 7CCh 4    Key Random/time/type/flags/chksum?           ;
      5C8h 86Ch 7D0h 100h Key Public RSA Key                           ;
      6C8h 86Ch 8D0h 4    Key Public RSA Exponent? (00,01,00,01)       ;
      6CCh 970h 8D4h 34h  Key padding/alignment (zerofilled)           ;/

Note: Above certificates should be just a 1:1 copy of the entries in cert.sys.
Note: "XS00000006" or "XS00000003" is found in cetk/tik's, in tmd's it's called "CP00000007".
Notes
The Title Version and Content Size/SHA1 entries are reflecting the NEWEST ".app" version (but the AES-CBC key should usually/always also work for older versions).
The homebrew NUS Downloader utility is saving TMD (520 bytes; with REMOVED certificate) and CETK (2468 bytes; with included certificate).

DSi SD/MMC Firmware dev.kp and cert.sys Certificate Files

FAT16:\sys\cert.sys ;3904 bytes (or 2560 bytes before DSi-Shop connection)
Data in this file is same on all retail DSi consoles (even for different regions like US and EUR and KOR).

      000h 300h  Public RSA Key "XS00000006" signed by "Root-CA00000001"
      300h 400h  Public RSA Key "CA00000001" signed by "Root"
      700h 300h  Public RSA Key "CP00000007" signed by "Root-CA00000001"
     Below NOT in Korea? Or NOT when notyet connected to DSi Shop?
      A00h 240h  Public ECC Key "MS00000008" signed by "Root-CA00000001"
      C40h 300h  Public RSA Key "XS00000003" signed by "Root-CA00000001"

The cert.sys for DSi debug version is different:

      000h 300h  Public RSA Key "CP00000005" signed by "Root-CA00000002"
      300h 300h  Public RSA Key "XS00000006" signed by "Root-CA00000002"
      600h 400h  Public RSA Key "CA00000002" signed by "Root"
      A00h 300h  Public RSA Key "CP00000007" signed by "Root-CA00000002"

More detailed, the retail version of cert.sys looks as so:

      000h 4    Signature Type (00,01,00,01) (100h-byte RSA)        ;\
      004h 100h Signature RSA-OpenPGP-SHA1 across 140h..2FFh        ;
      104h 3Ch  Signature padding/alignment (zerofilled)            ;
      140h 40h  Signature Name "Root-CA00000001", 00h-padded        ;
      180h 4    Key Type (00,00,00,01) (100h-byte RSA)              ;
      184h 40h  Key Name "XS00000006", 00h-padded                   ;
      1C4h 4    Key Random/time/type/flags/chksum?                  ;
      1C8h 100h Key Public RSA Key (92,FF,96,40..)                  ;
      2C8h 4    Key Public RSA Exponent? (00,01,00,01)              ;
      2CCh 34h  Key padding/alignment (zerofilled)                  ;/
      300h 4    Signature Type (00,01,00,00) (200h-byte RSA) (!)    ;\
      304h 200h Signature RSA-OpenPGP-SHA1 across 540h..6FFh        ;
      504h 3Ch  Signature padding/alignment (zerofilled)            ;
      540h 40h  Signature Name "Root", 00h-padded                   ;
      580h 4    Key Type (00,00,00,01) (100h-byte RSA)              ;
      584h 40h  Key Name "CA00000001", 00h-padded                   ;
      5C4h 4    Key Random/time/type/flags/chksum?                  ;
      5C8h 100h Key Public RSA Key (B2,79,C9,E2..)                  ;
      6C8h 4    Key Public RSA Exponent? (00,01,00,01)              ;
      6CCh 34h  Key padding/alignment (zerofilled)                  ;/
      700h 4    Signature Type (00,01,00,00) (100h-byte RSA)        ;\
      704h 100h Signature RSA-OpenPGP-SHA1 across 840h..9FFh        ;
      804h 3Ch  Signature padding/alignment (zerofilled)            ;
      840h 40h  Signature Name "Root-CA00000001", 00h-padded        ;
      880h 4    Key Type (00,00,00,01) (100h-byte RSA)              ;
      884h 40h  Key Name "CP00000007", 00h-padded                   ;
      8C4h 4    Key Random/time/type/flags/chksum?                  ;
      8C8h 100h Key Public RSA Key (93,BC,0D,1F..)                  ;
      9C8h 4    Key Public RSA Exponent? (00,01,00,01)              ;
      9CCh 34h  Key padding/alignment (zerofilled)                  ;/
     Below NOT when notyet connected to DSi Shop:
      A00h 4    Signature Type (00,01,00,01) (100h-byte RSA)        ;\
      A04h 100h Signature RSA-OpenPGP-SHA1 across B40h..C3Fh        ;
      B04h 3Ch  Signature padding/alignment (zerofilled)            ;
      B40h 40h  Signature Name "Root-CA00000001", 00h-padded        ;
      B80h 4    Key Type (00,00,00,02)   (ECC, sect233r1, non-RSA)  ;
      B84h 40h  Key Name "MS00000008", 00h-padded                   ;
      BC4h 4    Key Random/time/type/flags/chksum?                  ;
      BC8h 3Ch  Key Public ECC Key (point X,Y) (01,93,6D,08..)      ;
      C04h 3Ch  Key padding/alignment (zerofilled)                  ;/
      C40h 4    Signature Type (00,01,00,01) (100h-byte RSA)        ;\
      C44h 100h Signature RSA-OpenPGP-SHA1 across D80h..F3Fh        ;
      D44h 3Ch  Signature padding/alignment (zerofilled)            ;
      D80h 40h  Signature Name "Root-CA00000001", 00h-padded        ;
      DC0h 4    Key Type (00,00,00,01) (100h-byte RSA)              ;
      DC4h 40h  Key Name "XS00000003", 00h-padded                   ;
      E04h 4    Key Random/time/type/flags/chksum?                  ;
      E08h 100h Key Public RSA Key (AD,07,A9,37..)                  ;
      F08h 4    Key Public RSA Exponent? (00,01,00,01)              ;
      F0Ch 34h  Key padding/alignment (zerofilled)                  ;/

Cert chain for the DSi. Contains certificates with signed keys:

      Root-CA00000001:            used for signing the four certificates below
      Root-CA00000001-CP00000007: used for signing TMDs ("Content Protection"?)
      Root-CA00000001-MS00000008: used for signing per-console ECC keys ("Master"?)
      Root-CA00000001-XS00000003: used for signing tickets from the DSiWare Shop
      Root-CA00000001-XS00000006: used for signing (common) tickets ("access"?)

A similar file with the same name exists on the Wii.
FAT16:\sys\dev.kp ;446 bytes (encrypted), 414 bytes (when decrypted)
The dev.kp file is encrypted with ES Block Encryption (using same key X/Y as for .tik files):

      KEY_X[00h..03h] = 4E00004Ah                           ;\
      KEY_X[04h..07h] = 4A00004Eh                           ; same as for Tad
      KEY_X[08h..0Bh] = Port[4004D00h+4] xor C80C4B72h      ;
      KEY_X[0Ch..0Fh] = Port[4004D00h+0]                    ;/
      KEY_Y[00h..0Fh] = Constant (E5,CC,5A,8B,...)  ;from ARM7BIOS

DSi ES Block Encryption
The decrypted dev.kp contains following entries:

      000h 4    Signature Type (00,01,00,02) (ECC, sect233r1, non-RSA)  ;\
      004h 3Ch  Signature Hex numbers... across... below?               ;
      040h 40h  Signature padding/alignment (zerofilled)                ;
      080h 40h  Signature Name "Root-CA00000001-MS00000008", 00h-padded ;
      0C0h 4    Key Type (00,00,00,02)       (ECC, sect233r1, non-RSA)  ;
      0C4h 40h  Key Name "TWxxxxxxxx-08nnnnnnnnnnn1nn", 00h-padded      ;
      104h 4    Key Random/time/type/flags/chksum?                      ;
      108h 3Ch  Key Public ECC Key (point X,Y)       ;<-- public key    ;
      144h 3Ch  Key padding/alignment (zerofilled)                      ;
      180h 1Eh  Key Private ECC Key                  ;<-- private key   ;/

The "TWxxxxxxxx-08nnnnnnnnnnn1nn" string may vary:

      "TW" might be for DSi only (ie. it might be different on DSi XL or 3DS?)
      "xxxxxxxx" is 8-digit lower-case hex number (unknown where from; for .tik)
      "08nnnnnnnnnnn1nn" is 16-digit lower-case hex number (from Port 4004D00h)

Example:

      Signature across rest of block -- type = 0x00010002, ECC
      0000000: 00 01 00 02 00 db da 21 3b e1 f1 bf bb 4d dc 1d
      0000010: 60 29 da 19 42 1e 66 4f a8 e5 27 a1 d4 ea 46 7d
      0000020: 9b b4 00 95 c5 0d e8 fa ef a7 8d e9 bc 54 da c1
      0000030: 24 94 0b 7c ad a8 61 d5 05 97 c2 64 38 ad 18 f9

      0000040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
      0000050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
      0000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
      0000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

      Key used to sign this cert (Root-CA00000001-MS00000008)
      0000080: 52 6f 6f 74 2d 43 41 30 30 30 30 30 30 30 31 2d  Root-CA00000001-
      0000090: 4d 53 30 30 30 30 30 30 30 38 00 00 00 00 00 00  MS00000008
      00000a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
      00000b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

      Console ID string
      00000c0: 00 00 00 02 54 57 63 37 39 64 63 65 63 39 2d 30  ....TWc79dcec9-0
      00000d0: 38 61 32 30 32 38 37 30 31 30 38 34 31 31 38 00  8a2028701084118.
      00000e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
      00000f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

      Public ECC key (30 bytes, starting at 0x108)
      0000100: 00 00 00 00 6f dd de 42 01 e0 34 a3 19 bc a9 af
      0000110: 50 fe 8a ac 75 08 07 a9 3a 2c 21 51 93 ae 4a 90
      0000120: 6e 62 41 f1 a2 fe 00 00 3d 0a 13 97 da 53 17 98
      0000130: 69 38 65 67 ca f4 9c 87 ec 44 b7 eb d0 ec b8 3d
      0000140: 23 cf 7a 35 00 00 00 00 00 00 00 00 00 00 00 00
      0000150: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
      0000160: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
      0000170: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

      Private per-console ECC key, used for signing files on SD
      0000180: 01 12 9d e0 77 82 44 d3 ee 99 ad ce e5 fa fa ed
      0000190: c9 ab 8e a1 f9 b5 c8 14 3c 74 74 f8 19 3a

Note that the console id itself is burned in an OTP area of the TWL CPU, and changing the contents of this file will not actually change the console id.
This file contains the unique per-console ECC private-public key pair, along with a certificate issued by Nintendo.
This file is created by the DSi Shop, with data from a SOAP reply. The SOAP request data includes the hw console id, and the 0x100-byte RSA signature stored in NAND file "HWID.sgn". Trying to send that request would require a NAND dump, but when you have a NAND dump already sending that request is pointless since you can grab dev.kp from NAND.
Sending that request is pointless anyway since the dev.kp data from the server is random. The returned dev.kp data from the server for the EC private/public keys are random, the ticket consoleID immediately following TW before - in the twcert keyid is random as well. DSi Shop and System Settings don't contain any code for deleting dev.kp. If you try to delete/rename dev.kp manually from NAND a new dev.kp will be generated by the shop, but then the server will return an error since the server account public dev.kp cert won't match.
Data management can't be accessed when dev.kp doesn't exist since you'd have no twcert to sign/verify tads with, like when you never connected the DSi Shop server.

DSi SD/MMC Firmware Certificate/Keys (DER)

.der files (ASN.1)

      DSi Version Data, narc:\NintendoCA-G2.der           (unencrypted)
      DSi Version Data, narc:\.twl-*.der                  (ES Block encrypted)
      DSi Browser, rom:\ca\*.ca                           (unencrypted)
      DSi is-twl-update, *.der (dev unit public keys)     (unencrypted, stringless)
      DSi Dokodemi, rom:key\pubkey.der (only 162 bytes)   (unencrypted, stringless)
      3DS browser applet, RomFS:\browser\rootca.pem       (ASCII BASE64 .der's)
      3DS Syste, Data Archives 1, offline... cave.pem     (ASCII BASE64 .der)
      3DS Shared Data Archives, Non-Nintendo TLS, *.der   (unencrypted)
      3DS System Data Archives 1, ClCertA, RomFS:*.bin    (AES-CBC encrypted)
      3DS Nintendo Zone, RomFS:\certs\*.der               (unencrypted)
      3DS Nintendo Zone, RomFS:\certs\dev.pem             (ASCII BASE64 .der)
      3DS Nintendo Zone, RomFS:\certs\client.key          (ASCII BASE64 .der)
      3DS Miiverse olv applet, RomFS:\browser\cave.pem    (ASCII BASE64 .der)
      3DS Miiverse olv applet, RomFS:\browser\*.p12       (nested der-inside-der?)

For the BASE64 .pem variant, see:
3DS Files - BASE64 Encoding
There are two types of .der files:
Public keys with Certificates (these do usually contain lots of entries with many OIDs and name strings for certificate, company, country, email, etc).
Private keys (these do usually contain only a few entries, often without any OIDs at all, apart from the private key, they do usually also contain the public key & original prime numbers).

     _________________________ Tag,Length,Value Encoding __________________________

The files consist of several Tag-Length-Value (TLV) triplets. All data is in BIG-ENDIAN.
Tag

      bit6-7 class  (0=Universal, 1=Application, 2=Context-defined, 3=Private)
      bit5   form   (0=Primitive, 1=Constructed)
      bit4-0 number (0..1Fh)

Common are:

      BOOLEAN           UNIVERSAL  Primitive    00000001 (01h)
      INTEGER           UNIVERSAL  Primitive    00000010 (02h)
      BIT STRING        UNIVERSAL  Primitive    00000011 (03h)
      OCTET STRING      UNIVERSAL  Primitive    00000100 (04h)
      NULL              UNIVERSAL  Primitive    00000101 (05h)
      OBJECT IDENTIFIER UNIVERSAL  Primitive    00000110 (06h)
      UTF8String        UNIVERSAL  Primitive    00001100 (0Ch)
      PrintableString   UNIVERSAL  Primitive    00010011 (13h)
      TeletexString     UNIVERSAL  Primitive    00010100 (14h)
      IA5String         UNIVERSAL  Primitive    00010110 (16h)
      Time String                                        (17h)  in dsi version data
      BMPString         UNIVERSAL  Primitive    00011110 (1Eh)
      SEQUENCE          UNIVERSAL  Constructed  00110000 (30h)
      SEQUENCE OF       UNIVERSAL  Constructed  00110000 (30h)
      SET               UNIVERSAL  Constructed  00110001 (31h)
      SET OF            UNIVERSAL  Constructed  00110001 (31h)
      -unknown-         CONTEXT    Primitive             (80h) ;3ds miiverse .p12
      -unknown-         CONTEXT    Constructed           (A0h) ;dsi version (small)
      -unknown-         CONTEXT    Constructed           (A3h) ;dsi browser (big)

Length
The length encoding depends on bit7 of the first byte:

      when bit7=0 --> bit6-0 contain length (0..127 bytes)
      when bit7=1 --> bit6-0 contain number of following length bytes

The length does rarely exceed 16bits, the most common lengths are:

      len          = Length 0..127 bytes     (with len<80h)
      81h,len      = Length 128..255 bytes   (with len>7Fh)
      82h,msb,lsb  = Length 256..65535 bytes (with msb:len>00FFh)

     ___________________________________ Tag's ____________________________________

01h,Len,Value - BOOLEAN
Allows to define a boolean flag. Len is always 1, and value must be:

      value[0] = flag (00h=False, or FFh=True)

02h,Len,Value - INTEGER
Allows to define integer, including "large" values like RSA keys. Bit7 of the first byte is treated as sign bit, when storing unsigned values one must insert a leading 00h byte if the high bit is set.

      value[0..(len-1)] = data   ;(len)*8 bits (with sign bit in MSB of 1st byte)

03h,Len,Value - BIT STRING
Allows to define data that isn't a multiple of 8 bits. Or multiples of 8 bits are also working (when first byte is 00h), this sometimes used to store RSA keys as unsigned integers, or, more weirdly, it can also contain further Tag,Len,Value items (eg. SEQUENCE tags with separate RSA key and RSA exponent enclosed in the BIT string) (... somewhat as if the BIT string contains a child .der file?).

      value[0] = number of unused bits in LSB of last byte (0..7)
      value[1..(len-1)] = data   ;(len-1)*8-unused bits

04h,Len,Value - OCTET STRING
Allows to define data that is a multiple of 8 bits. This can contain general purpose stuff, including mixup's of flags, integers, arrays, text strings.

      value[1..(len-1)] = data   ;(len-1)*8 bits

05h,Len - NULL
Allows to define empty/zero data, Len must be 00h, and accordingly, value is 0-byte tall.
06h,Len,Value - OBJECT IDENTIFIER (OID)
OIDs can be used as prefix for other tags (eg. to indicate that the following tag(s) contain a username or email address). The OIDs are usually expressed as a series of decimal numbers separated by dots. In binary form, these are stored as follows:

      value[0] = 2nd+(1st*40)       ;\
      value[1] = 3rd                ; basic encoding for 7bit values
      value[2] = 4th                ;
      etc.                          ;/

There are some special cases: The 1st number must be 0..2. The 2nd number must be 0..39 when 1st=0..1 (there is no such limit when 1st=2).
Values bigger than 7bit are split into two or more 7bit fragments (with bit7=1 in the leading fragments, and bit7=0 in the last fragment), that variable-length encoding is used whenever "2nd+(1st*40)" or "3rd,4th,etc." are exceeding 7bits. For example,

      1.2.3.4.255        --> 2Ah, 03h, 04h, 81h,7Fh
      2.999.1234.1.2.3.4 --> 88h,37h, 89h,52h, 01h, 02h, 03h, 04h

There are millions of OID values (assigned by thousands of organizations), the OID's can be deciphered with online databases, for example,

      http://oidref.com/

However, DER certificates are usually containing only a few standard OID values. See the "OID Values" list below for the OID's found in DSi/3DS certificates.
0Ch,Len,Value - UTF8 String (Unicode byte & multibyte chars)
13h,Len,Value - Printable String (some ASCII A-Z,a-z,0-9,space,'()+,-./:=?)
14h,Len,Value - T61 Teletext String (ITU T.61) (extended 8bit ASCII)
16h,Len,Value - IA5 String (aka ISO 646, full 7bit ASCII with @&{}[] etc.)
17h,Len,Value - Time String (numeric chars "0-9" and timezone suffix)
1Eh,Len,Value - BMP String (aka UTF-16 Unicode) (two-byte chars)
Allows to define things like company/address/country strings, using various extended or restriceted variants of the ASCII character set. The most common type is Printable String (Tag=13h) for basic english, or IA5 String(Tag=16h) for email addresses with "@" characters.

      value[0..(len-1)] = text string

The Time String (Tag=17h) can contain UTC (GMT) time in different variants (without seconds, with seconds, or with seconds+century; and optional seconds fraction; terminated by a "Z" character, or by +/-HHMM timezone info):

      "YYMMDDHHMMZ"           ;\
      "YYMMDDHHMM+HHMM"       ; UTC Time without seconds, and optional timezone
      "YYMMDDHHMM-HHMM"       ;/
      "YYMMDDHHMMSSZ"         ;\
      "YYMMDDHHMMSS+HHMM"     ; UTC Time with seconds, and optional timezone
      "YYMMDDHHMMSS-HHMM"     ;/
      "YYYYMMDDHHMMSSZ"       ;\Generalized Time with seconds and century, and
      "YYYYMMDDHHMMSS.SSSSZ"  ;/optional seconds fraction (no trailing zeroes)

30h,Len,Value - Sequence (or Sequence of)
31h,Len,Value - Set (or Set of)
A0h,Len,Value - Undoc_A0h
A3h,Len,Value - Undoc_A3h

      value[0..(len-1)] = contains further Tag,Length,Data values

XXX

     _________________________________ OID Values _________________________________

      0.9.2342.19200300.100.1.*  /itu-t/data/pss/ucl/pilot/pilotAttributeType/..
      0.9.2342.19200300.100.1.1  ../userid                 ;unused
      0.9.2342.19200300.100.1.25 ../domainComponent        ;unused
      1.2.840.113533.7.65.*  /iso/member-body/us/nortelnetworks/entrust/nsn-ce/..
      1.2.840.113533.7.65.0  ../0                    ;dsi browser equifax_s_ca.ca
      1.2.840.113549.1.1.*   /iso/member-body/us/rsadsi/pkcs/pkcs-1/..
      1.2.840.113549.1.1.1   ../rsaEncryption
      1.2.840.113549.1.1.2   ../rsaEncryptionWithMD2       ;dsi browser rsa.ca
      1.2.840.113549.1.1.3   ../rsaEncryptionWithMD4       ;unused
      1.2.840.113549.1.1.4   ../rsaEncryptionWithMD5       ;dsi browser thawte.ca
      1.2.840.113549.1.1.5   ../rsaEncryptionWithSHA1
      1.2.840.113549.1.1.11  ../rsaEncryptionWithSHA256
      1.2.840.113549.1.1.12  ../rsaEncryptionWithSHA384    ;unused
      1.2.840.113549.1.1.13  ../rsaEncryptionWithSHA512    ;unused
      1.2.840.113549.1.1.14  ../rsaEncryptionWithSHA224    ;unused
      1.2.840.113549.1.7.*   /iso/member-body/us/rsadsi/pkcs/pkcs-7/..
      1.2.840.113549.1.7.1   ../data   ;for nested .der?   ;3ds miiverse olv applet
      1.2.840.113549.1.7.6   ../encryptedData              ;"inside" pkcs-7
      1.2.840.113549.1.9.*   /iso/member-body/us/rsadsi/pkcs/pkcs-9/..
      1.2.840.113549.1.9.1   ../emailAddress
      1.2.840.113549.1.9.21  ../localKeyID                 ;"inside" pkcs-7
      1.2.840.113549.1.12.1.*  /iso/member-body/us/rsadsi/pkcs/pkcs-12/PbeIds/..
      1.2.840.113549.1.12.1.3  ../pbeWithSHAAnd3-KeyTripleDES-CBC ;\inside pkcs-7
      1.2.840.113549.1.12.1.6  ../pbeWithSHAAnd40BitRC2-CBC       ;/
      1.2.840.113549.1.12.10.* /iso/member-body/us/rsadsi/pkcs/pkcs-12/Version1/.
      1.2.840.113549.1.12.10.1.2 ../BagIds/ShroudedKeyBag         ;-inside pkcs-7
      1.3.6.1.4.1.311.*      /iso/org/dod/internet/prv/enterprise/microsoft/..
      1.3.6.1.4.1.311.20.2   ../20/2/?  ;incomplete blurp? ;3ds browser securetrust
      1.3.6.1.4.1.311.21.1   ../21.1    ;unknown blurp?    ;3ds browser securetrust
      1.3.6.1.5.5.7.1.*      /iso/org/dod/internet/security/mechanisms/pkix/pe/..
      1.3.6.1.5.5.7.1.12     ../id-pe-logotype     ;3ds shared data TLS, CA_8.der
      1.3.14.3.2.*           /iso/org/oiw/secsig/algorithms/..
      1.3.14.3.2.26          ../hashAlgorithmIdentifier    ;3ds miiverse olv applet
      2.5.4.*                /joint/ds/attributeType/..
      2.5.4.3                ../commonName
      2.5.4.4                ../surname
      2.5.4.5                ../serialNumber
      2.5.4.6                ../countryName
      2.5.4.7                ../localityName
      2.5.4.8                ../stateOrProvinceName
      2.5.4.9                ../streetAddress
      2.5.4.10               ../organizationName
      2.5.4.11               ../organizationalUnit
      2.5.4.12               ../title
      2.5.4.42               ../givenName
      2.5.29.*               /joint/ds/certificateExtension/..
      2.5.29.14              ../subjectKeyIdentifier
      2.5.29.15              ../keyUsage
      2.5.29.16              ../privateKeyUsagePeriod  ;dsi browser equifax_s_ca.ca
      2.5.29.17              ../subjectAltName             ;3ds browser japnese gov
      2.5.29.18              ../issuerAltName              ;unused
      2.5.29.19              ../basicConstraints
      2.5.29.20              ../cRLNumber                  ;unused
      2.5.29.21              ../reasonCode                 ;unused
      2.5.29.22              ../expirationDate             ;unused
      2.5.29.23              ../instructionCode            ;unused
      2.5.29.24              ../invalidityDate             ;unused
      2.5.29.25              ../cRLDistributionPoints      ;unused
      2.5.29.26              ../issuingDistributionPoint   ;unused
      2.5.29.27              ../deltaCRLIndicator          ;unused
      2.5.29.28              ../issuingDistributionPoint   ;unused
      2.5.29.29              ../certificateIssuer          ;unused
      2.5.29.30              ../nameConstraints            ;unused
      2.5.29.31              ../cRLDistributionPoints
      2.5.29.32              ../certificatePolicies        ;dsi browser swiss_g2.ca
      2.5.29.33              ../policyMappings             ;unused
      2.5.29.34              ../policyConstraints          ;unused
      2.5.29.35              ../authorityKeyIdentifier
      2.5.29.36              ../policyConstraints          ;unused
      2.5.29.37              ../extKeyUsage                ;3ds browser usertrust
      2.16.840.1.113730.1.*  /joint/country/us/organization/netscape/cert-ext/..
      2.16.840.1.113730.1.1  ../cert-type               ;dsi browser tc_c2_ca.ca
      2.16.840.1.113730.1.8  ../ca-policy-url           ;dsi browser tc_c2_ca.ca
      2.16.840.1.113730.1.13 ../comment

DSi SD/MMC Firmware Font File

FAT16:\sys\TWLFontTable.dat ;843.1K (D2C40h bytes) (compressed) (Normal)
FAT16:\sys\TWLFontTable.dat ;568.1K (8E020h bytes) (compressed) (China)
FAT16:\sys\TWLFontTable.dat ;158.9K (27B80h bytes) (compressed) (Korea)
This file contains LZrev-compressed fonts in the NFTR (Nitro font) format.
This is the only real long filename that exceeds the 8.3 limit on the DSi (alternate short name is TWLFON~1.DAT). DSi software is often using a virtual filename "nand:/<sharedFont>" on ARM9 side, which is then replaced by "nand:/sys/TWLFontTable.dat" on ARM7 side.
The font can be used by DSiware titles (DSi ROM cartridges usually don't have eMMC access, and thus cannot use the font).

      0000h       80h  RSA-SHA1 on entries [0080h..009Fh] (23h,8Bh,F9h,08h,...)
      0080h       4    Date? (00h,31h,07h,08h=Normal, 00h,27h,05h,09h=China/Korea)
      0084h       1    Number of NFTR resources (NUM) (3=Normal, 9=China/Korea)
      0085h       1    Zerofilled
      0086h       1    Unknown (0=Normal, 4=China, 5=Korea)
      0087h       5    Zerofilled
      008Ch       14h  SHA1 on below resource headers at [00A0h+(0..NUM*40h-1)]
      00A0h+N*40h 20h  Resource Name in ASCII, padded with 00h
      00C0h+N*40h 4    Compressed Resource Size in .dat file   ;\compressed
      00C4h+N*40h 4    Compressed Resource Start in .dat file  ;/
      00C8h+N*40h 4    Decompressed Resource Size              ;-decompressed
      00CCh+N*40h 14h  SHA1 on Compressed Resource at [Start+0..Size-1]
      ...         ..   Compressed Font Resources (with 16-byte alignment padding)

The resources are containing the same font thrice (at three different sizes), normal consoles have only three resources (0,1,2), chinese/korean consoles have nine resources (six zerofilled 40h-byte entries, and three actually used entries: 3,4,5 for china, or 6,7,8 for korea). The name strings of the resources are:

      "TBF1_l.NFTR"     ;0 Large  16x21 pixels ;\Normal (blurry: 4 colors used)
      "TBF1_m.NFTR"     ;1 Medium 12x16 pixels ; 2bpp, 7365 characters, Unicode
      "TBF1_s.NFTR"     ;2 Small  10x12 pixels ;/
      "TBF1-cn_l.NFTR"  ;3 Large  16x21 pixels ;\China (crisp-clear: 2 colors used)
      "TBF1-cn_m.NFTR"  ;4 Medium 12x16 pixels ; 2bpp, 7848 characters, Unicode
      "TBF1-cn_s.NFTR"  ;5 Small  12x13 pixels ;/
      "TBF1-kr_l.NFTR"  ;6 Large  16x21 pixels ;\Korea (crisp-clear: 2 colors used)
      "TBF1-kr_m.NFTR"  ;7 Medium 12x16 pixels ; 2bpp, 3679 characters, Unicode
      "TBF1-kr_s.NFTR"  ;8 Small  12x12 pixels ;/

All characters have proportional width (as defined in the Character Width chunk), eg. the width of the 16x21 font can be max 16 pixels (plus spacing), but most of the characters are less than 16 pixels wide.
The character numbers in the Char Map chunks are 16bit Unicode, supporting ASCII, plus extra punctuation marks, european letters with accent marks, greek, cyrillic, math symbols, and thousands of japanese letters. There are also some custom nintendo-specific symbols (like buttons and Wii symbols).
Notes
The blurry japanese letters aren't actually legible (especially for the smaller font sizes). Also note that the size of small font varies for the three regions (ie. 10x12, 12x13, or 12x12).
LZrev Compressed Font Resource Format

      ..   uncompressed area (usually 15h bytes)
      ...  compressed area (decompressed backwards)
      ..   footer: padding (to 4-byte boundary)
      3    footer: size of footer+compressed area (offset to compressed.bottom)
      1    footer: size of footer (offset to compressed.top)
      4    footer: extra DEST size (offset to decompressed.top)
      ..   zeropadding to 10h-byte boundary

LZ Decompression Functions
The original decompression function can be found in Flipnote (EUR) at address 20BF8E4h (which is mainly doing error checking, and then calling the actual decompression function at 20BF938h) (Flipnote does also contain several custom fonts, the TWLFontTable.dat file is used only for Flipnote's "Help" function).
Nitro Font Resources
The format of the decompressed data is Nintendo's standard Nitro Font format:
DS Cartridge Nitro Font Resource Format

DS Cartridge Nitro Font Resource Format

Nitro Font Resource File formats (compressed & uncompressed)
Nitro Fonts are often found as .NFTR or .ZFTR files (within NitroROM filesystems). The DSi firmware does additionally contain Nitro Fonts in a .dat file (in the eMMC FAT16 filesystem).

      .NFTR  Raw uncompressed Nitro Font Resource
      .ZFTR  LZ11-compressed Nitro Font Resource
      .dat   Archive with three LZrev-compressed Nitro Font Resources (used on DSi)

The .ZFTR files are containing a 4-byte compression header, followed by the compressed data (starting with the first compression flag byte, following by the first chunk header). For details, see:
LZ Decompression Functions
The DSi's "\sys\TWLFontTable.dat" contains three fonts, using a special LZ compression variant (with the data decompressed backwards, starting at highest memory address). For details, see:
DSi SD/MMC Firmware Font File
Either way, the decompressed fonts are looking as follows:
Nitro Font Resource Header Chunk

      00h 4    Chunk ID "RTFN" (aka NFTR backwards, Nitro Font Resource)
      04h 2    Byte Order    (FEFFh) (indicates that above is to be read backwards)
      06h 2    Version       (0100h..0102h) (usually 0101h or 0102h)
      08h 4    Decompressed Resource Size (000A3278h) (including the NFTR header)
      0Ch 2    Offset to "FNIF" Chunk, aka Size of "RTFN" Chunk (0010h)
      0Eh 2    Total number of following Chunks (0003h+NumCharMaps) (0018h)

Font Info Chunk

      00h      4    Chunk ID "FNIF" (aka FINF backwards, Font Info)
      04h      4    Chunk Size (1Ch or 20h)
      08h      1    Unknown/unused (zero)
      09h xxx  1    Height                       ;or Height+/-1
      0Ah xxx  1    Unknown (usually 00h, or sometimes 1Fh maybe for chr(3Fh)="?")
      0Bh      2    Unknown/unused (zero)
      0Dh xxx  1    Width           ;\or Width+1
      0Eh xxx  1    Width_bis (?)   ;/
      0Fh      1    Encoding (0=UTF8, 1=Unicode, 2=SJIS, 3=CP1252) (usually 1)
      10h      4    Offset to Character Glyph chunk, plus 8
      14h      4    Offset to Character Width chunk, plus 8
      18h      4    Offset to first Character Map chunk, plus 8
      1Ch      (1)  Tile Height                                ;\present only
      1Dh xxx  (1)  Max Width or so +/-?                       ; when above
      1Eh      (1)  Underline location                         ; Chunk Size = 20h
      1Fh      (1)  Unknown/unused (zero)                      ;/(version 0102h)

Character Glyph Chunk (Tile Bitmaps)

      00h      4    Chunk ID "PLGC" (aka CGLP backwards, Character Glyph)
      04h      4    Chunk Size (10h+NumTiles*siz+padding)
      08h      1    Tile Width in pixels
      09h      1    Tile Height in pixels
      0Ah      2    Tile Size in bytes (siz=width*height*bpp+7)/8)
      0Ch      1    Underline location
      0Dh      1    Max proportional Width including left/right spacing
      0Eh      1    Tile Depth (bits per pixel) (usually 1 or 2, sometimes 3)
      0Fh      1    Tile Rotation (0=None/normal, other=see below)
      10h      ...  Tile Bitmaps
      ...      ...  Padding to 4-byte boundary (zerofilled)

All tiles are starting on a byte boundary. However, the separate scanlines aren't necessarily byte-aligned (for example, at 10pix width, a byte may contain rightmost pixels of one line, followed by leftmost pixels of next line).
Bit7 of the first byte of a bitmap is the MSB of the upper-left pixel, bit6..0 are then containing the LSB(s) of the pixel (if bpp>1), followed by the next pixels of the scanline, followed by further scanlines; the data is arranged as straight Width*Height bitmap (without splitting into 8x8 sub-tiles).
Colors are ranging from Zero (transparent/background color) to all bit(s) set (solid/text color).
The meaning of the Tile Rotation entry is unclear (one source claims 0=0', 1=90', 2=270', 3=180', and another source claims 0=0', 2=90', 4=180', 6=270', and for both sources, it's unclear if the rotation is meant to be clockwise or anti-clockwise).
Character Width Chunk

      00h      4    Chunk ID "HDWC" (aka CWDH backwards, Character Width)
      04h      4    Chunk Size (10h+NumTiles*3+padding)
      08h      2    First Tile Number (should be 0000h)
      0Ah      2    Last Tile Number  (should be NumTiles-1)
      0Ch      4    Unknown/unused (zero)
      10h+N*3  1    Left Spacing (to be inserted left of character bitmap)
      11h+N*3  1    Width of Character Bitmap (excluding left/right spacing)
      12h+N*3  1    Total Width of Character (including left/right spacing)
      ...      ...  Padding to 4-byte boundary (zerofilled)

Defines the proportional character width for each tile. Entry [11h+N*3] defines the width of the non-transparent character area (which left-aligned in the Tile Bitmap; any further pixels in the Bitmap are unused/zero). The other two entries define the left/right spacing that is needed to be added to the character.
Character Map(s) - Translation Tables for ASCII/JIS/etc to Tile Numbers?

      00h      4    Chunk ID "PAMC" (aka CMAP backwards, Character Map)
      04h      4    Chunk Size (14h+...+padding)
      08h      2    First Character (eg. 0020h=First ASCII Char)
      0Ah      2    Last Character  (eg. 007Eh=Last ASCII Char)
      0Ch      4    Map Type (0..2, for entry 14h and up, see there)
      10h      4    Offset to next Character Map, plus 8   (0=None, no further)

For Map Type0, Increasing TileNo's assigned to increasing CharNo's:

      14h      2    TileNo for First Char (and increasing for further chars)
      16h      2    Padding to 4-byte boundary (zerofilled)

For Map Type1, Custom TileNo's assigned to increasing CharNo's:

      14h+N*2  2    TileNo's for First..Last Char (FFFFh=None; no tile assigned)
      ...      0/2  Padding to 4-byte boundary (zerofilled)

For Map Type2, Custom TileNo's assigned to custom CharNo's:

      14h      2    Number of following Char=Tile groups...
      16h+N*4  2    Character Number
      18h+N*4  2    Tile Number
      ...      2    Padding to 4-byte boundary (zerofilled)

These chunks are containing tables for translating character numbers (eg. Unicode numbers, or whatever format is selected in the Font Info chunk) to actual Tile Numbers (ie. the way how tiles are ordered in the Glyph and Width chunks).
Font files can contain several Character Map chunks (eg. some Type0 chunks for Char 0020h..007Eh and Char 00A0h..00FFh, plus some Type1 chunks for areas like Char 037Eh..0451h, plus one large Type2 chunk for everything that wasn't defined in the other chunks; the First/Last Character entries are don't care for Type2, they are usually set to First=0000h and Last=FFFFh in that case). Characters that are NOT included in any of the tables should be treated as undefined (as so for any characters that are assigned as Tile=FFFFh in Type1 chunks).
Unicode character numbers are stored as 16bit values. Unknown how other character numbers like UTF8 or SJIS are stored.

LZ Decompression Functions

LZSS, Yaz0, LZ11 - Decompression for BIOS/SWI and ZFTR Font Files
LZSS/Yaz0/LZ11 are very similar formats, with small differences in the header and compression codes, which could be summarized as so:

      10,ss,ss,Ss   ;ID(10h), Size(Ssssss)          ;-LZSS header
      11,ss,ss,Ss   ;ID(11h), Size(Ssssss)          ;-LZ11 header
      "Yaz0",Ss,ss,ss,ss,0,0,0,0,0,0,0,0            ;-Yaz0 header
      Ff            ;Flags(Ff), each 8 entries      ;-Flags (bit7=first)
      1N,nn,nP,pp   ;Disp(Ppp)+1, Len(Nnnn)+111h    ;\
      0N,nP,pp      ;Disp(Ppp)+1, Len(Nn)+11h       ; LZ11, when flag=1
      NP,pp         ;Disp(Ppp)+1, Len(N)+1          ;/
      0P,pp,Nn      ;Disp(Ppp)+1, Len(Nn)+12h       ;\Yaz0, when flag=0
      NP,pp         ;Disp(Ppp)+1, Len(N)+2          ;/
      NP,pp         ;Disp(Ppp)+1, Len(N)+3          ;-LZSS, when flag=1
      Dd            ;Databyte(Dd)                   ;-When flag other than above

Below function can decompress LZSS data (as used by BIOS SWIs), and the LZ11 variant (with 11h in the header; as used by ZFTR font files, but not being compatible with the BIOS SWI functions on neither GBA nor NDS nor DSi).

      if src has "LZ77" or "CMPR" prefix then src=src+4    ;skip prefix (if any)
      typ=byte[src]
      if typ=59h                            ;YAZ0
        errif (bytes[src+0..3]<>"Yaz0") OR (bytes[src+8..15]<>0)
        fin=dst+BigEndian(word[src+04h]), src=src+16
      else                                  ;LZSS/LZ11
        fin=dst+(word[src]/100h), src=src+4
      endif
     @@collect_more:
      flagbits=[src], src=src+1, numflags=8
      if typ=59h then flagbits=flagbits XOR 0FFh    ;-invert for YAZ0
     @@decompress_lop:
      if dst>=fin then goto @@decompress_done
      if numflags=0 then goto @@collect_more
      numflags=numflags-1, flagbits=flagbits*2
      if (flagbits AND 100h)=0 then
        [dst]=[src], dst=dst+1, src=src+1
      else
        if typ=10h        ;LZ10 aka LZSS (BIOS SWI compatible)
          len=3
          len=len+[src]/10h, disp=001h+([src] AND 0Fh)*100h+[src+1], src=src+2
        elseif typ=11h    ;LZ11 (special extended format)
          if [src]/10h>1 then len=001h
          if [src]/10h<1 then len=011h+([src] AND 0Fh)*10h, src=src+1
          if [src]/10h=1 then len=111h+([src] AND 0Fh)*1000h+[src+1]*10h, src=src+2
          len=len+[src]/10h, disp=001h+([src] AND 0Fh)*100h+[src+1], src=src+2
        elseif typ=59h    ;YAZ0 (special extended format)
          len=[src]/10h, disp=001h+([src] AND 0Fh)*100h+[src+1], src=src+2
          if len=0 then len=[src]+12h, src=src+1, else len=len+02h
        endif
        for i=1 to len, [dst]=[dst-disp], dst=dst+1, next i
      endif
      goto @@decompress_lop
     @@decompress_done:
      ret

The LZSS variant is implemented in GBA/NDS/DSi BIOS SWI functions:
BIOS Decompression Functions
LZSS and LS11 are used with many NDS/DSi/3DS files. LZSS/LZ11 can be detected by checking for 10h/11h in first byte, and additionally checking for:

      Extension is ".lz", ".lz77", ".LZ", or extension is preceeded by "_LZ."
      Less common extensions are ".l", ".lex", ".cmp" (and various others)
      Bytes[5..10] (after header+flags) contain IDs alike "NARC",FFFEh etc.
      File starts with "LZ77",10h or "CMPR",10h (both rather uncommon)

Prefix strings exist in a few LZSS files ("LZ77" in Super Mario 64 DS, or "CMPR" in Nanostray), then followed by normal LZSS data starting with type=10h.
Yaz0 files can be detected by checking for "Yaz0" in first 4 bytes. Yaz0 is used by a few titles only (eg. used by DSi Sound, rom:\texture.szs). Yaz0 is widely believed to use RLE compression (don't ask why).
LZrev - Reverse Decompression

      Used for DSi Font (within TWLFontTable.dat)
      Used for 3DS .code files (within NCCH ExeFS filesystems)
      Used for files with .blz extension (eg. in DSi Flipnote, DSi Paper Plane)
      Used for ALZ1+LZrev double compression with .blz extension (eg. DSi Dr Mario)

This function resembles LZSS, but with src/dst processed in reversed order (starting at highest memory location). Further differences are that the header is replaced by a footer, and, weirdly, data is copied from "disp+3" instead of "disp+1". The decompression is intended to use a single buffer for src/dst (so the source data will be overwritten during decompression) (in order to avoid overwriting still unprocessed data, some bytes near start of file are usually left uncompressed, eg. for the font files, decompression usually ends somewhere at fin=buf+15h rather than at fin=buf+0).

      dest_size=src_size+[src+src_size-4]   ;when dest_size is unknown (for 3DS)
      allocate buf(dest_size), copy "src_size" bytes from file to buf
      src=buf+src_size                      ;origin = pointing after footer
      dst=src+(word[src-4])-1               ;dst = src plus extra len
      fin=src-(word[src-8] AND 00FFFFFFh)   ;fin = src minus compressed_len
      src=src-(byte[src-5])-1               ;src = src minus footer_len
     @@collect_more:
      flagbits=[src], src=src-1, numflags=8
     @@decompress_lop:
      if src<=fin then goto @@decompress_done
      if numflags=0 then goto @@collect_more
      numflags=numflags-1, flagbits=flagbits*2
      if (flagbits AND 100h)=0 then
        [dst]=[src], dst=dst-1, src=src-1
      else
        len=([src]/10h)+3, disp=([src] AND 0Fh)*100h+([src-1])+3, src=src-2
        for i=1 to len, [dst]=[dst+disp], dst=dst-1, next i
      endif
      goto @@decompress_lop
     @@decompress_done:
      ret

Note: The footer_len at [src-5] is usually 08h+0..3 (with 0..3 padding bytes to make the footer entries & file size word aligned).
LZ/Huffman
Apart from the above chubby functions, there are at least two compression schemes trying to implement real serious compression:
GBA Cart e-Reader VPK Decompression
LZ Decompression Functions ASH0
Some titles contain regular .zip files (with Stored and Deflated files):

      DSi Browser (rom:\skin\std_skin.zip) -- corrupted .zip (with 0D,0A appended)
      DSi Shop    (rom:\skin\std_skin.zip) -- intact .zip (unlike above)
      3DS Browser applet (RomFS:\browser\page\..\*.zip)

ZIP Decompression
Others
Arika has brewed up a obscure compression+archive+encryption format:
DS Encrypted Arika Archives with ALZ1 compression

LZ Decompression Functions ASH0

ASH0 is used by several games on different consoles (eg. DSi Flipnote, rom:\SampleData.Eu\*.ash).
ash_decompress(source,dest)

      collected[0]=80000000h          ;stream 0 initially empty (endflag in bit31)
      collected[1]=80000000h          ;stream 1 initially empty (endflag in bit31)
      src[0]=source+0                 ;stream 0 start
      for i=0 to 3, id[i]=read_bits(0,8), next i, if id[0..3]<>'ASH0' then error
      dest_end=dest+read_bits(0,32)   ;size of decompressed data
      src[1]=source+read_bits(0,32)   ;stream 1 start
      load_huffman_tree(0,9)          ;load stream 0 tree (9bit len/data values)
      load_huffman_tree(1,11)         ;load stream 1 tree (11bit disp values)
     decompress_loop:
      temp=0, while temp<8000h do temp=tree[0][temp+read_bits(0,1)]
      if temp<8100h then
        [dest]=temp AND FFh, dest=dest+1      ;store one uncompressed data byte
      else
        disp=0, while disp<8000h do disp=tree[1][disp+read_bits(1,1)]
        len=temp+3-8100h, disp=disp+1-8000h
        for j=1 to len, [dest]=[dest-disp], dest=dest+1, next j
      if dest<dest_end then decompress_loop
      ret

read_bits(s,num)

      data=0
      for i=1 to num
       shl collected[s],1    ;move next bit to carry, or set zeroflag if empty
       if zeroflag
        collected[s]=[src[s]]*1000000h+[src[s]+1]*10000h+[src[s]+2]*100h+[src[s]+3]
        src[s]=src[s]+4      ;read data in 32bit units, in reversed byte-order
        carryflag=1          ;endbit
        rcl collected[s],1   ;move bit31 to carry (and endbit to bit0)
       rcl data,1            ;move carry to data
      next i
      ret(data)

load_huffman_tree(s,width)

      stacktop=sp
      tree_index=0
     load_lop:
      if getbits(0,1)=1
       push tree_index+1   ;right (bit0=right)      ;\
       push tree_index     ;left                    ; memorize left/right indices
       tree_index=tree_index+2                      ; and load more
       goto load_lop                                ;/
      dta=getbits(0,width)+8000h           ;get data (bit15=data)
     resolve_lop:
      pop idx                              ;parent index
      tree[s][idx]=dta                     ;store data (or child_index)
      if (idx AND 1)=0 then goto load_lop  ;load more (if it was left node)
      dta=idx-1   ;child_index (to be stored at next parent_index)
      if stacktop<>sp then goto resolve_lop
      ret

Note: The official max tree sizes appear to be:

      tree[0] = about 200h*6 halfwords
      tree[1] = about 800h*6 halfwords

ZIP Decompression

Overall ZIP structure

      Local file headers, with file data
      Central directory, with file headers, and optional signature
      End of central directory record, with optional comment

ZIP Local file header

      000h 4    local file header signature (04034B50h)
      004h 2    version needed to extract (os*256+major*10+minor) (common=14h=v2.0)
      006h 2    general purpose bit flag  (common=0)
      008h 2    compression method (0=stored, 8=deflated, other=rare?)
      00Ah 2    last mod file time
      00Ch 2    last mod file date
      00Eh 4    crc32 of uncompressed file data (zero when size=0)
      012h 4    compressed size
      016h 4    uncompressed size
      01Ah 2    file name length
      01Ch 2    extra field length
      01Eh ..   file name (or "folder/file" name)
      ...  ..   extra field
      ...  ..   compressed file data

ZIP Central directory structure
Central directory entries:

      000h 4    central file header signature (02014B50h)
      004h 2    version made by
      006h 2    version needed to extract
      008h 2    general purpose bit flag
      00Ah 2    compression method (0=stored, 8=deflated, other=rare?)
      00Ch 2    last mod file time
      00Eh 2    last mod file date
      010h 4    crc32 of uncompressed file data
      014h 4    compressed size
      018h 4    uncompressed size
      01Ch 2    file name length
      01Eh 2    extra field length
      020h 2    file comment length
      022h 2    disk number start
      024h 2    internal file attributes
      026h 4    external file attributes
      02Ah 4    offset of local file header (from begin of disk number [022h])
      02Eh ..   file name (or "folder/file" name)
      ...  ..   extra field
      ...  ..   file comment (usually ASCII text, if any)

Central directory signature (optional, after last directory entry)

      000h 4    header signature (05054B50h)
      004h 2    size of data
      006h ..   signature data (variable size, whatever crap)

ZIP End of central directory record

      000h 4    end of central dir signature (06054B50h)
      004h 2    number of this disk (usually 0000h)
      006h 2    number of disk with the start of central directory
      008h 2    total number of entries in the central directory on this disk
      00Ah 2    total number of entries in the central directory
      00Ch 4    size of the central directory
      010h 4    offset of start of central directory, on disk number [006h]
      014h 2    .ZIP file comment length (can be zero even if comment/junk follows)
      016h ..   .ZIP file comment (usually ASCII text, if any)

Official specs
The official ZIP specs can be reportedly found on pkware.com (but it's unknown which browsers are capable of viewing that webpage):

      http://support.pkware.com/home/pkzip/developer-tools/appnote

Alternately, the currently latest specs can be found here:

      http://pkware.cachefly.net/webdocs/APPNOTE/APPNOTE-6.3.9.TXT  ;July 2020

That specs include info on rarely used things (including other compression methods, encryption, compressed directory entries, and support for 64bit offset/size values).
Inflate/Deflate
Inflate/Deflate is a common (de-)compression algorithm, used in ZIP files since 1991. And also used by ZLIB and GZIP. In the PSX world, it's also used by the .CDZ cdrom-image format.
Inflate - Core Functions
Inflate - Initialization & Tree Creation
Inflate - Headers and Checksums
Note: Very old ZIP versions from 1989/1990 did use Shrink and Implode instead of Deflate.

Inflate - Core Functions

tinf_uncompress(dst,src)

     tinf_init()                    ;init constants (needed to be done only once)
     tinf_align_src_to_byte_boundary()
     repeat
      bfinal=tinf_getbit()          ;read final block flag (1 bit)
      btype=tinf_read_bits(2)       ;read block type (2 bits)
      if btype=0 then tinf_inflate_uncompressed_block()
      if btype=1 then tinf_build_fixed_trees(), tinf_inflate_compressed_block()
      if btype=2 then tinf_decode_dynamic_trees(), tinf_inflate_compressed_block()
      if btype=3 then ERROR         ;reserved
     until bfinal=1
     tinf_align_src_to_byte_boundary()
     ret

tinf_inflate_uncompressed_block()

     tinf_align_src_to_byte_boundary()
     len=LittleEndian16bit[src+0]                             ;get len
     if LittleEndian16bit[src+2]<>(len XOR FFFFh) then ERROR  ;verify inverse len
     src=src+4                                                ;skip len values
     for i=0 to len-1, [dst]=[src], dst=dst+1, src=src+1, next i    ;copy block
     ret

tinf_inflate_compressed_block()

     repeat
      sym1=tinf_decode_symbol(tinf_len_tree)
      if sym1<256
       [dst]=sym1, dst=dst+1
      if sym1>256
       len  = tinf_read_bits(length_bits[sym1-257])+length_base[sym1-257]
       sym2 = tinf_decode_symbol(tinf_dist_tree)
       dist = tinf_read_bits(dist_bits[sym2])+dist_base[sym2]
       for i=0 to len-1, [dst]=[dst-dist], dst=dst+1, next i
     until sym1=256
     ret

tinf_decode_symbol(tree)

     sum=0, cur=0, len=0
     repeat                         ;get more bits while code value is above sum
      cur=cur*2 + tinf_getbit()
      len=len+1
      sum=sum+tree.table[len]
      cur=cur-tree.table[len]
     until cur<0
     return tree.trans[sum+cur]

tinf_read_bits(num) ;get N bits from source stream

     val=0
     for i=0 to num-1, val=val+(tinf_getbit() shl i), next i
     return val

tinf_getbit() ;get one bit from source stream

     bit=tag AND 01h, tag=tag/2
     if tag=00h then tag=[src], src=src+1, bit=tag AND 01h, tag=tag/2+80h
     return bit

tinf_align_src_to_byte_boundary()

     tag=01h   ;empty/end-bit (discard any bits, align src to byte-boundary)
     ret

Inflate - Initialization & Tree Creation

tinf_init()

     tinf_build_bits_base(length_bits, length_base, 4, 3)
     length_bits[28]=0, length_base[28]=258
     tinf_build_bits_base(dist_bits, dist_base, 2, 1)
     ret

tinf_build_bits_base(bits,base,delta,base_val)

     for i=0 to 29
      bits[i]=min(0,i-delta)/delta
      base[i]=base_val
      base_val=base_val+(1 shl bits[i])
     ret

tinf_build_fixed_trees()

     for i=0 to 6, tinf_len_tree.table[i]=0, next i       ;[0..6]=0   ;len tree...
     tinf_len_tree.table[7,8,9]=24,152,112                ;[7..9]=24,152,112
     for i=0 to 23,  tinf_len_tree.trans[i+0]  =i+256, next i  ;[0..23]   =256..279
     for i=0 to 143, tinf_len_tree.trans[i+24] =i+0,   next i  ;[24..167] =0..143
     for i=0 to 7,   tinf_len_tree.trans[i+168]=i+280, next i  ;[168..175]=280..287
     for i=0 to 111, tinf_len_tree.trans[i+176]=i+144, next i  ;[176..287]=144..255
     for i=0 to 4, tinf_dist_tree.table[i]=0, next i   ;[0..4]=0,0,0,0,0 ;\dist
     tinf_dist_tree.table[5]=32                        ;[5]=32           ; tree
     for i=0 to 31, tinf_dist_tree.trans[i]=i, next i  ;[0..31]=0..31    ;/
     ret

tinf_decode_dynamic_trees()

     hlit  = tinf_read_bits(5)+257           ;get 5 bits HLIT (257-286)
     hdist = tinf_read_bits(5)+1             ;get 5 bits HDIST (1-32)
     hclen = tinf_read_bits(4)+4             ;get 4 bits HCLEN (4-19)
     for i=0 to 18, lengths[i]=0, next i
     for i=0 to hclen-1                      ;read lengths for code length alphabet
      lengths[clcidx[i]]=tinf_read_bits(3)   ;get 3 bits code length (0-7)
     tinf_build_tree(code_tree, lengths, 19) ;build code length tree
     for num=0 to hlit+hdist-1               ;decode code lengths for dynamic trees
      sym = tinf_decode_symbol(code_tree)
      len=1, val=sym                         ;default (for sym=0..15)
      if sym=16 then len=tinf_read_bits(2)+3, val=lengths[num-1] ;3..6 previous
      if sym=17 then len=tinf_read_bits(3)+3, val=0              ;3..10 zeroes
      if sym=18 then len=tinf_read_bits(7)+11, val=0             ;11..138 zeroes
      for i=1 to len, lengths[num]=val, num=num+1, next i
     tinf_build_tree(tinf_len_tree,  0,      hlit)    ;\build trees
     tinf_build_tree(tinf_dist_tree, 0+hlit, hdist)   ;/
     ret

tinf_build_tree(tree, first, num)

     for i=0 to 15, tree.table[i]=0, next i     ;clear code length count table
     ;scan symbol lengths, and sum code length counts...
     for i=0 to num-1, x=lengths[i+first], tree.table[x]=tree.table[x]+1, next i
     tree.table[0]=0
     sum=0          ;compute offset table for distribution sort
     for i=0 to 15, offs[i]=sum, sum=sum+tree.table[i], next i
     for i=0 to num-1  ;create code to symbol xlat table (symbols sorted by code)
      x=lengths[i+first], if x<>0 then tree.trans[offs[x]]=i, offs[x]=offs[x]+1
     next i
     ret

tinf_data

     clcidx[0..18] = 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15   ;constants

     typedef struct TINF_TREE:
       unsigned short table[16]     ;table of code length counts
       unsigned short trans[288]    ;code to symbol translation table

     TINF_TREE tinf_len_tree   ;length/symbol tree
     TINF_TREE tinf_dist_tree  ;distance tree
     TINF_TREE code_tree       ;temporary tree (for generating the dynamic trees)
     unsigned char lengths[288+32]   ;temporary 288+32 x 8bit ;\for dynamic tree
     unsigned short offs[16]         ;temporary 16 x 16bit    ;/creation

     unsigned char  length_bits[30]
     unsigned short length_base[30]
     unsigned char  dist_bits[30]
     unsigned short dist_base[30]

Inflate - Headers and Checksums

tinf_gzip_uncompress(dst, destLen, src, sourceLen)

     src_start=src, dst_start=dst                 ;memorize start addresses
     if (src[0]<>1fh or src[1]<>8Bh) then ERROR   ;check id bytes
     if (src[2]<>08h) then ERROR                  ;check method is deflate
     flg=src[3]                                   ;get flag byte
     if (flg AND 0E0h) then ERROR                 ;verify reserved bits
     src=src+10                                                 ;skip base header
     if (flg AND 04h) then src=src+2+LittleEndian16bit[src]     ;skip extra data
     if (flg AND 08h) then repeat, src=src+1, until [src-1]=00h ;skip file name
     if (flg AND 10h) then repeat, src=src+1, until [src-1]=00h ;skip file comment
     hcrc=(tinf_crc32(src_start, src-src_start) & 0000ffffh))   ;calc header crc
     if (flg AND 02h) then x=LittleEndian16bit[src], src=src+2  ;get header crc
     if (flg AND 02h) then if x<>hcrc then ERROR                ;verify header
     tinf_uncompress(dst, destLen, src, src_start+sourceLen-src-8)  ;----> inflate
     crc32=LittleEndian32bit[src], src=src+4   ;get crc32 of decompressed data
     dlen=LittleEndian32bit[src], src=src+4    ;get decompressed length
     if (dlen<>destLen) then ERROR                              ;verify dest len
     if (crc32<>tinf_crc32(dst_start,dlen)) then ERROR          ;verify crc32
     ret

tinf_zlib_uncompress(dst, destLen, src, sourceLen)

     src_start=src, dst_start=dst         ;memorize start addresses
     hdr=BigEndian16bit[src], src=src+2   ;get header
     if (hdr MOD 31)<>0 then ERROR        ;check header checksum (modulo)
     if (hdr AND 20h)>0 then ERROR        ;check there is no preset dictionary
     if (hdr AND 0F00h)<>0800h then ERROR ;check method is deflate
     if (had AND 0F000h)>7000h then ERROR ;check window size is valid
     tinf_uncompress(dst, destLen, src, sourceLen-6)      ;------> inflate
     chk=BigEndian32bit[src], src=src+4                   ;get data checksum
     if src-src_start<>sourceLen then ERROR               ;verify src len
     if dst-dst_start<>destLen then ERROR                 ;verify dst len
     if a32<>tinf_adler32(dst_start,destLen)) then ERROR  ;verify data checksum
     ret

tinf_adler32(src, length)

     s1=1, s2=0
     while (length>0)
      k=max(length,5552)
      for i=0 to k-1, s1=s1+[src], s2=s2+s1, src=src+1, next i
      s1=s1 mod 65521, s2=s2 mod 65521, length=length-k
     return (s2*10000h+s1)

DS Encrypted Arika Archives with ALZ1 compression

Used in Arika's DSi Dr. Mario and reportedly also in other Arika titles.

      rom:\INFO.DAT - contains encrypted directory
      rom:\GAME.DAT - contains ALZ1 compressed files, and some uncompressed files

Arika INFO.DAT header

      000h 10h   Title (eg. "*Dr.Mario-DSi!!!" used as decryption key)
      010h 14h   Zerofilled                                     ;\
      024h 4     Sector size (100h) (if zero: default to 800h)  ;
      028h 4     Unknown, maybe version (1)                     ; encrypted
      02Ch 4     Number of used Directory entries (eg. 288h)    ;
      030h N*30h Directory entries (see below)                  ;/
      ...  ..    Ununsed Directory entries (40h-filled)         ;-unencrypted

Arika Directory Entry format:

      000h 20h   Filename (ASCII, max 31 chars, plus zeropadding)
      020h 4     File Size in bytes
      024h 4     File Offset in sector units (in GAME.DAT file)
      028h 4     File Size in sector units
      02Ch 4     Decompressed File Size in bytes (same as [20h] when uncompressed)

The file names must contain lowercase "a..z" in first character (the software is generating a not-so-fast "quick lookup table" based on the 1st char, and produces memory corruption if it's outside of the "a..z" range).
Arika archives contain only files, not folders. However, the filenames do usually contain slashes (eg. "com/chr/e_eff_vy01.dat"), so software could split those names into folder+filename, if desired.
Arika INFO.DAT decryption

      if buf[0]=00h then exit ;unencrypted
      for i=10h to filesize-1, buf[i]=((buf[i] ror 4) xor FFh)-buf[i AND 0Fh]

The strength of the 10h-byte key pattern is that people will have a hard time to realize that the file is encrypted at all; otherwise they could easily decrypt it by just gazing at it in a hex editor.
Arika ALZ1 compression
ALZ1 is almost identical to LZss, with some useless changes:
The 4-byte fileheader contains "ALZ1", without any info about the decompressed size (which must be taken from INFO.DAT instead).
The compression flags are inverted (0=compressed), and processed backwards (LSB first).
The dictionary is stored in separate 1000h-byte ringbuffer (which is initially zerofilled, so the files can directly start with compressed 00h bytes).
The 16bit compression codes are byte-swapped (1st byte is dict.lsb, 2nd byte is dict.msb*10h+(len-3)), with dict being the dictionary's read index.
The dictionary's initial write index is FEEh, all compressed/uncompressed data written to dest is also written to the dictionary.
Arika ALZ1+LZrev double compression
The file "com/m2dres_narc.blz" is double compressed (LZrev inside of ALZ1, which can actually reduce the size because LZrev or ALZ1 alone are having rather poor compression ratios) (whereas, LZrev can be only detected via the ".blz" extension, so make sure not to forget the extension after handling the first compression layer).
Other files like "lng/eur/fr/man/man_narc.blz" are only LZrev compressed.

DSi SD/MMC Firmware Log Files

FAT16:\sys\log\shop.log (32 bytes)

      0000h 20h   Zerofilled

Unknown if this file can contain anything else.
FAT16:\sys\log\product.log (573 bytes)
Contains some ASCII text with version, date (YY/MM/DD), and time (HH:SS) info (using 0Ah as CRLF):

      0,BOARD,START,1.5,09/01/14,14:52,000055, ,
      0,BOARD,OK,1.5,09/01/14,14:53,000055, ,
      0,TP_CAL,OK,2.0, , , ,(647 811)-(3478 3245),
      0,AGING,OK,1.0, , , ,Time=60:20(m:s)
      Count=32,
      0,FINAL,START,1.5,09/01/15,09:52,000084,TWL Ver.2.0,
      0,FINAL,OK,1.5,09/01/15,09:52,000084,TWL Ver.2.0,
      0,MIC,OK,2.1, , , ,All Test Passed,
      0,CAMERA,OK,2.1, , , , ,
      0,WRFU,START,0.60,09/01/15,10:03,000143,P000063 G000143 717cfde74f5ef6763473,
      0,WRFU,OK,0.60,09/01/15,10:04,000143,PCVer:1.7f
      R-53 -55 E0.00 0.00,
      0,IMPORT,START,1.0, , , , ,
      0,IMPORT,OK,1.0, , , ,Region=EUR,
      0,NCHECK,OK,1.0, , , , ,

FAT16:\sys\log\sysmenu.log (16Kbytes)
Contains several groups of three text lines. Each "#FFT" group begins with two 0Ah characters, and is followed by space padding for 256-byte alignment of the next group).
Below is some example (with blank space removed, original 40-digit hash strings abbreviated to "xxxx..xx", and some lines are replaced by "...").

      #FFT 13-08-18[SUN] 12:37:10
      title: HNAP
      DHT_PAHSE1_FAILED (sub info): hash1     - 8dfc..59
      #FFT 13-08-18[SUN] 12:37:10
      title: HNAP
      DHT_PAHSE1_FAILED (sub info): calc_hash - 7eca..f5
      #FFT 13-08-18[SUN] 12:37:11
      title: HNAP
      menuRedIplManager.cpp [l.514] RED FATAL 0000000010000000 (0000000041575445)
      #FFT 13-08-18[SUN] 12:37:11
      title: HNAP
      menuResetCallback.cpp [l.50] type 0
      #FFT 13-08-18[SUN] 13:44:16
      title: HNAP
      DHT_PAHSE1_FAILED (sub info): hash1Addr-02799e38
      #FFT 13-08-18[SUN] 13:44:16
      title: HNAP
      DHT_PAHSE1_FAILED (sub info): hash1     - 8dfc..59
      ...
      ...
      #FFT 13-09-10[TUE] 22:07:39
      title: HNAP
      menuResetCallback.cpp [l.50] type 0
      #FFT 13-09-14[SAT] 14:59:16
      title: HNAP
      SYSMi_LoadTitleThreadFunc: some error has occurred.
      #FFT 13-09-14[SAT] 14:59:16
      title: HNAP
      SYSMi_AuthenticateTitleThreadFunc: loaded 1 times.
      #FFT 13-09-14[SAT] 14:59:17
      title: HNAP
      menuRedIplManager.cpp [l.514] RED FATAL 0000800000002100 (0003000049524544)
      #FFT 13-09-14[SAT] 14:59:17
      title: HNAP
      menuResetCallback.cpp [l.50] type 0
      #FFT 00-01-03[MON] 20:50:18
      title: HNAP
      WHITELIST_NOTFOUND (sub info): no entry for phase 1/2.
      #FFT 00-01-03[MON] 20:50:18
      title: HNAP
      WHITELIST_NOTFOUND (sub info): no entry for phase 3.
      #FFT 00-01-03[MON] 20:50:18
      title: HNAP
      SYSMi_LoadTitleThreadFunc: some error has occurred.
      #FFT 00-01-03[MON] 20:50:18
      title: HNAP
      SYSMi_AuthenticateTitleThreadFunc: loaded 1 times.
      #FFT 00-01-03[MON] 20:50:19
      title: HNAP
      menuRedIplManager.cpp [l.514] RED FATAL 0000800008000100 (000000004143454b)
      #FFT 00-01-03[MON] 20:50:19
      title: HNAP
      menuResetCallback.cpp [l.50] type 0
      #FFT 00-01-05[WED] 01:03:16
      title: HNAP
      WHITELIST_NOTFOUND (sub info): no entry for phase 1/2.
      ...
      ...
      #FFT 00-01-01[SAT] 00:02:37
      title: HNAP
      SYSMi_AuthenticateTitleThreadFunc: loaded 1 times.
      #FFT 00-01-01[SAT] 00:02:38
      title: HNAP
      menuRedIplManager.cpp [l.514] RED FATAL 0002004000000100 (00000000414e5045)
      #FFT 00-01-01[SAT] 00:02:38
      title: HNAP
      menuResetCallback.cpp [l.50] type 0

DSi SD/MMC Firmware Misc Files

FAT16:\sys\HWINFO_S.dat (aka Serial/Barcode) (16Kbytes)

      0000h 80h   RSA-SHA1-HMAC across entries [0088h..00A3h]
                  (with RSA key from Bootsectors, and also from Launcher)
                  (with SHA1-HMAC key = SHA1([4004D00h..4004D07h], aka Console ID)
      0080h 4     Header, Version or so (00000001h)
      0084h 4     Header, Size of entries at [0088h..00A3h] (0000001Ch)
      0088h 4     Bitmask for Supported Languages (3Eh for Europe) (as wifi_flash)
      008Ch 4     Unknown (00,00,00,00)  (bit0=flag for 4004020h.bit0=wifi ?)
      0090h 1     Console Region (0=JPN, 1=USA, 2=EUR, 3=AUS, 4=CHN, 5=KOR)
      0091h 12    Serial/Barcode (ASCII, 11-12 characters; see console sticker)
      009Dh 3     Unknown (00,00,3C)                     ;"<"
      00A0h 4     Title ID LSBs for Launcher ("PANH", aka HNAP spelled backwards)
      00A4h 3F5Ch Unused (FFh-filled)

Entries [0088h..009Fh] are copied to [2FFFD68h..2FFFD7Fh]. Entry [00A0h] is used to construct the region-specific filename of the Launcher (System Menu).
The RSA with Console ID means that one cannot change the region/language stuff.
The 3DS has similar data stored in file SecureInfo_A on 3DS partition.
FAT16:\sys\HWINFO_N.dat (16Kbytes)

      0000h 14h   SHA1 on entries [088h..09Bh]
      0014h 6Ch   Zerofilled
      0080h 4     Header, Version or so (00000001h)
      0084h 4     Header, Size of entries at [0088h..009Bh] (00000014h)
      0088h 4     Some per-console ID (used what for?)
      008Ch 10h   Some per-console ID (used in "Tad Files")
      009Ch 3F64h Unused (FFh-filled)

Entries [0088h..009Bh] are copied to [2000600h..2000613h].
FAT16:\sys\HWID.sgn (256 bytes)

      0000h 100h  RSA-OpenPGP-SHA1 across... whatever?

Seems to be used only by DSi Shop. The RSA keys are unknown for retail version. Also unknown WHAT the SHA1 is computed on (probably some console and/or region IDs).
The System Updater tool (for debug version) contains both public and private RSA keys for the file; the keys don't work for retail version though.
The OpenPGP bytes are same as for SWI 23h (but with more FFh padding bytes due to the 100h-byte RSA size).
FAT16:\shared2\0000 (2048K) (sound recorder)
Huge 2Mbyte file with several used areas (and many zerofilled areas).
Contains a FAT12 filesystem with several voice .dat files for the Sound Recorder of the Nintendo DSi Sound utility. Unused clusters seem to contain garbage (maybe un-encrypted eMMC sectors).

      voice18111008215651000010001.dat  ;14402h bytes
      voice20131018211242000010001.dat  ;14402h bytes
      voice19111008215708000010001.dat  ;14402h bytes
      voice00131018211411003110001.dat  ;14402h bytes
      voice01150418144405002110001.dat  ;14402h bytes
      voiceNNYYMMDDHHMMSS00NN10001.dat  ;14402h bytes

Note: The DSi Sound utility is additionally having a 512Kbyte private.sav file (also containing a FAT12 filesystem; although it seems to contain only a MBR, FATs, and an empty Root directory - plus garbage in unused clusters).
FAT16:\import\
FAT16:\progress\
FAT16:\tmp\es\write\
Empty folders.

DSi SD/MMC Firmware Wifi Firmware

FAT16:\title\0003000f\484e4341\content\000000vv.app (aka Wifi Firmware)
WLFIRM aka WLANFIRM (compressed, non-executable datafile, for all regions, v0:13B80h bytes, v1:13BA0h bytes, v2:17E60h bytes). This file contains Wifi Firmwares for the Xtensa CPU in the Atheros AR60xxG chips on the DWM-W0xx Wifi Daughterboards.

      DSi Firmware 1.0            --> Wifi Firmware v0 (supports AR6002)
      DSi Firmware 1.1 thru 1.2   --> Unknown (presumably v0 or v1)
      DSi Firmware 1.3            --> Wifi Firmware v1 (supports AR6002)
      DSi Firmware 1.4 thru 1.4.5 --> Wifi Firmware v2 (supports AR6002+AR6013)
      Note: The AR6002 part is exact same in v1 and v2 (with same SHA1 in Part 1)
      However, part 1.c was slightly smaller in v0, apparently some small bugfix.

The BIOS ROM in the AR60xxG chips can be extended/upgraded by uploading the firmware into RAM (the RAM isn't nonvolatile, so this must be done each time after power-up, that is done by the System Menu (launcher), so DSi games won't need to upload the firmware themselves.

      00000h 80h    RSA-SHA1    (on [00080h..0009Fh]) (via RSA key from BIOS) ;\
      00080h 14h    Header SHA1 (on [000A0h..000FFh])                         ; SHA
      00094h 4      Header Size (00000060h, for entries 000A0h..000FFh)       ;
      00098h 8      Zerofilled                                                ;/
      000A0h 2      Version (0000h,0001h,0002h for v0,v1,v2)          ;\
      000A2h 1      Number of parts (01h..02h)   ;(02h in v2 only)    ; Header
      000A3h 1      Unknown/zero?    (00h)                            ;
      000A4h 4      Part 1 Start (00000100h) ;(in v1: E0h)  ;\Part 1  ; with IDs
      000A8h 4      Part 1 Size  (00013AC0h)                ; DWM-W015; as in wifi
      000ACh 4      Part 1 ID    (00000001h) (=DWM-W015)    ; AR6002G ; flash[1FDh]
      000B0h 14h    Part 1 SHA1  (on [00100h..13BBFh])      ;/        ;
      000C4h 4      Part 2 Start (00013BC0h)                ;\Part 2  ; ;\
      000C8h 4      Part 2 Size  (000042A0h)                ; DWM-W024; ; not in
      000CCh 4      Part 2 ID    (00000002h) (=DWM-W024)    ; AR6013G ; ; version 1
      000D0h 14h    Part 2 SHA1  (on [13BC0h..17E5Fh])      ;/        ; ;/
      000E4h 1Ch    Zerofilled (padding to 20h-byte boundary)         ;/
      00100h 1      Part 1 num subheader's    (04h) (a/b/c/d)                    ;\
      00101h 1      Part 1 num ChipID's       (02h)                              ;
      00102h 2      Part 1 offset to ChipID's (0044h)                            ;
      00104h 10h    Part 1.a firm/main (00000080h,00013458h,80000001h,00502400h) ;
      00114h 10h    Part 1.b database  (000134E0h,000002BCh,00000002h,0052D944h) ;
      00124h 10h    Part 1.c stub/code (000137A0h,000002DEh,00000004h,00515000h) ;
      00134h 10h    Part 1.d stub/data (00013A80h,00000030h,00000005h,00502400h) ;
      00144h 8      Part 1 ChipID 1 ;alternate IDs ?       (02010001h,20000188h) ;
      0014Ch 8      Part 1 ChipID 2 ;CHIP_ID, ROM_VERSION  (02000001h,20000188h) ;
      00154h 4      Part 1 Firmware Version: 2.1.0.123               (2100007Bh) ;
      00158h 0Ch    Part 1 RAM vars/base/size    (00500400h,00500000h,0002E000h) ;
      00164h 1Ch    Zerofilled                                                   ;
      00180h 13460h Part 1.a data (13458h compressed bytes, +8 bytes zeropadding);
      135E0h 2C0h   Part 1.b data (2BCh bytes, +04h bytes zeropadding) ;database ;
      138A0h 2E0h   Part 1.c data (2DEh bytes, +02h bytes zeropadding) ;stubcode ;
      13B80h 40h    Part 1.d data (30h bytes, +10h bytes zeropadding)  ;stubdata ;/
      13BC0h 1      Part 2 num subheader's    (04h)                              ;\
      13BC1h 1      Part 2 num ChipID's       (02h)                              ;
      13BC2h 2      Part 2 offset to ChipID's (0044h)                            ;
      13BC4h 10h    Part 2.a firm/main (00000080h,00002EECh,80000001h,00524C00h) ;
      13BD4h 10h    Part 2.b database  (00002F80h,00000FC0h,00000002h,0053F040h) ;
      13BE4h 10h    Part 2.c stub/code (00003F40h,00000312h,00000004h,00527000h) ;
      13BF4h 10h    Part 2.d stub/data (00004260h,00000038h,00000005h,00524C00h) ;
      13C04h 8      Part 2 ChipID 1 ;CHIP_ID, ROM_VERSION  (0D000000h,23000024h) ;
      13C0Ch 8      Part 2 ChipID 2 ;alternate IDs?        (0D000001h,23000024h) ;
      13C14h 4      Part 2 Firmware Version: 2.3.0.108               (2300006Ch) ;
      13C18h 0Ch    Part 2 RAM vars/base/size    (00520000h,00520000h,00020000h) ;
      13C24h 1Ch    Zerofilled                                                   ;
      13C40h 2F00h  Part 2.a data (2EECh compressed bytes,+14h bytes zeropadding);
      16B40h FC0h   Part 2.b data (FC0h bytes, +00h bytes zeropadding)           ;
      17B00h 320h   Part 2.c data (312h bytes, +0Eh bytes zeropadding)           ;
      17E20h 40h    Part 2.d data (38h bytes, +08h bytes zeropadding)            ;/

The a/b/c/d subheaders consist of File Source Offset (relative to Start of Part 1/2 accordingly), Length, ID/Flags, and RAM Destination Address.
The stub/code and stub/data parts are loaded and executed first (the stub is reading calibration data from I2C bus EEPROM; this is decoupled from the main firmware because hardware implementations could use different calibration sources like I2C chips or SPI chips or mass-storage devices).
Thereafter, firm/main and database are loaded and executed. The "LZ" compressed firm/main part is automatically decompressed on the Xtensa side, the "LZ" stuff is some kind of "tag,len,disp" format:

      Part 1.a data: 9F,FF,FF,FF,FF,FF,FF,00,00,00,00,9F,04,04,..
      Part 2.a data: 5E,00,00,00,00,5E,04,04,5E,08,08,41,5F,49,..

The first byte identifies the "tag" value (this should be the value used least often in the uncompressed data). The following bytes are plain uncompressed data, mixed with "tag,len,disp" values (which will copy "len" bytes from "dest-disp" to "dest"). A special case is "tag,00h", which will store the "tag" value at dest. The len and disp values can consist of one or more byte(s) each (the LSB aka last byte is indicated by bit7=0; for example, "84h,86h,0Fh" would mean 01030Fh). For some odd reason, the values are always "len<=disp" (even for zerofilled regions where "len>disp" would be useful).

DSi SD/MMC Firmware System Settings Data Files

The DSi stores System Settings (and Title ID of most recent System Menu index) on eMMC in two identical files: TWLCFG0.dat and TWLCFG1.dat.
If both files are intact then the newer file is taken (as indicated by the update counter; for some weird reason, the DSi System Menu is always updating BOTH files, so they are usually both "newer").
For NDS compatibility, some of the data is additionally stored on Wifi FLASH:
DS Firmware User Settings
The TWL data and the NDS-style data are also copied to RAM:

      2000400h 128h   TWLCFGn.dat bytes [088h..1AFh]
      2FFFC80h 70h    Wifi FLASH User Settings (fmw[newest_user_settings])
      2FFFDFCh 4      Pointer to 2000400h

For some reason, most DSi games are containing some initialization code for repairing or initializing the above pointer, as so:

      if [2FFFDFCh]=0 then [2FFFDFCh]=2000400h

The RAM data at 2000400h isn't actually used by too many games though (one program that is using it is Flipnote).
Some games are attempting to adopt the System Setting's language selection as game language, games should do that only if they do support that language (a bad example is the german version of Magic Made Fun: Deep Psyche, which defaults to French when using English as system language).
FAT16:\shared1\TWLCFG0.dat (16Kbytes) (System Settings Data)
FAT16:\shared1\TWLCFG1.dat (16Kbytes) (System Settings Data)

      File RAM  Siz   Description
      000h -    14h   SHA1 on entries [088h..1AFh]
      014h -    6Ch   Zerofilled
      080h -    1     Version or so (01h)
      081h -    1     Update Counter (0..7Fh, wraps after 7bit)     ;fmw_user[070h]
      082h -    2     Zero (0000h)
      084h -    4     Size of below RAM area (00000128h)
      088h 000h 1     Unknown (0Fh) (bit3 set when wireless comms are enabled)
      089h 001h 2     Zerofilled
      08Bh 003h 1     Unknown (01h) (happens to be 00h after.. country change?)
      08Ch 004h 1     Zero
      08Dh 005h 1     Country code, same as Wii country codes (eg. 40h=Albania)
      08Eh 006h 1     Selected Language (eg. 1=English)        ;fmw_user[064h,075h]
      08Fh 007h 1     RTC Year (last date change) (max 63h=2099)    ;fmw_user[066h]
      090h 008h 4     RTC Offset (difference in seconds on change)  ;fmw_user[068h]
      094h 00Ch 4     Zerofilled (or FFh-filled) (=MSBs of above?)
      098h 010h 1     Flags (01h) (bit0 set when EULA was accepted) (0=newcountry?)
                      ...or EULA version (to be same/higher than carthdr[20Eh])?
      099h 011h 9     Zerofilled
      0A2h 01Ah 1     Alarm Hour   (0..17h)                         ;fmw_user[052h]
      0A3h 01Bh 1     Alarm Minute (0..3Bh)                         ;fmw_user[053h]
      0A4h 01Ch 2     Zerofilled
      0A6h 01Eh 1     Alarm Enable (0=Off, 1=On)                    ;fmw_user[056h]
      0A7h 01Fh 2     Zerofilled
      0A9h 021h 4     Unknown (09 1E 00 03)  (2nd.byte.LSB E=English, F=French ??)
      0ADh 025h 3     Zerofilled
      0B0h 028h 8     Title ID (most recent System Menu selection)      ;cart[230h]
      0B8h 030h 2x2   TSC calib (adc.x1,y1) 12bit ADC-position      ;fmw_user[058h]
      0BCh 034h 2x1   TSC calib (scr.x1,y1) 8bit pixel-position     ;fmw_user[05Ch]
      0BEh 036h 2x2   TSC calib (adc.x2,y2) 12bit ADC-position      ;fmw_user[05Eh]
      0C2h 03Ah 2x1   TSC calib (scr.x2,y2) 8bit pixel-position     ;fmw_user[062h]
      0C4h 03Ch 4     Unknown (9C 20 01 02)
      0C8h 040h 4     Zerofilled
      0CCh 044h 1     Favorite color (also Sysmenu Cursor Color)    ;fmw_user[002h]
      0CDh 045h 1     Zero
      0CEh 046h 2     Birthday (month, day)                   ;fmw_user[003h..004h]
      0D0h 048h 14h+2 Nickname (UCS-2), max 10 chars+EOL      ;fmw_user[006h..019h]
      0E6h 05Eh 34h+2 Message (UCS-2), max 26 chars+EOL       ;fmw_user[01Ch..04Fh]
      11Ch 094h 1     Parental Controls Flags (bit0=Parental, bit1-6=Pictochat,etc)
      11Dh 095h 6     Zero
      123h 09Bh 1     Parental Controls Region (0=Off, 3=German/USK, 4=French?)
      124h 09Ch 1     Parental Controls Years of Age Rating (00h..14h)  ;cart[2F0h]
      125h 09Dh 1     Parental Controls Secret Question (00h..05h)
      126h 09Eh 1     Parental Controls Unknown (can be 00h, 06h, or 07h)
      127h 09Fh 2     Zero
      129h 0A1h 4+1   Parental Controls PIN (ASCII digits) 4 digits+EOL
      12Eh 0A6h 80h+2 Parental Controls Secret Answer (UCS-2), max 64 chars+EOL
      1B0h -    3E50h Unused (FFh-filled)

Additionally, there's some stuff in RAM (maybe current Wifi Firmware version):

      -    1E0h 1     WlFirm Type (1=DWM-W015, 2=DWM-W024) (as wifi_flash[1FDh])
      -    1E1h 1     WlFirm Unknown (zero)
      -    1E2h 2     WlFirm CRC16 with initial value FFFFh on [1E4h..1EFh]
      -    1E4h 0Ch   WlFirm Version? RAM_area? (as from "Wifi Firmware" file)
      -    1F0h 10h   WlFirm Unknown (zero)
      -    200h 14h   Hexvalues from HWINFO_N.dat
      -    214h 0Ch   Unused/padding? (zero)

Unknown TWLCFG entries:

      Language and Flags  2  fmw_user[064h] (particulary: Flags)
      More Parental Control stuff

Parental controls fields are all zero when not in use.

DSi SD/MMC Firmware Version Data File

verdata (00030005-HNLx) is a bundle of data which corresponds to a release of the "System Menu" -- every time Nintendo announces a new version of the system menu, they will update one or more other titles and then update this title. The verdata filesize is constant for all versions/regions (1B50h bytes). Existing verdata downloads on Nintendo's server are:

      00000001..00000009  jpn         (9 versions)
      00000003..00000009  usa/eur/aus (7 versions)
      00000001..00000006  chn         (6 versions)
      00000002..00000006  kor         (5 versions)

Apart from those downloads/updates, each region did probably originally have an older version pre-installed. The japanese 1.0J firmware did oddly have 00000000.app files for BOTH japan and usa installed (whereof the latter contained 0.1A instead of 1.0A as version string).
FAT16:\title\0003000f\484e4cgg\content\000000vv.app (aka Version Data)

      0000h 80h  RSA-SHA1 on entries [0080h..end of file]
      0080h ...  NARC (Nitro Archive) ...

The NARC is a nintendo-specific virtual filesystem. For details, see:
DS Cartridge NitroROM and NitroARC File Systems
The NARC archive contains the following files:

     .twl-nup-cert.der    - server cert for software update server
     .twl-nup-prvkey.der  - client-side private key for software update server
     .twl-shop-cert.der   - server cert for Shopping Channel server
     .twl-shop-prvkey.der - client-side private key for Shopping Channel server
     NintendoCA-G2.der    - Certificate Authority cert, used to sign other certs
     eula_url.bin         - URL to the EULA text for this system update,
                            generally https://cfh.t.app.nintendowifi.net/eula/
     nup_host.bin         - server to query for the next system update,
                            generally nus.t.shop.nintendowifi.net:443
     time_stamp.bin       - build date for this version, eg. 00281108 (28 Nov 2008)
     user_area_size.bin   - eg. 08000000h (signed) (=128Mbyte? aka 1024 "blocks"?)
     version.bin          - firmware version (and version/region string)

The NARC is usually mounted as "verdata:" device (eg. "verdata:/version.bin").
The four ".twl-*.der" files are encrypted with ES Block Encryption (using a fixed key):

      KEY[00h..0Fh] = Constant (08,2F,61,38,...)  ;from ARM7BIOS

DSi ES Block Encryption
For the decrypted .der files (and unecrypted NintendoCA-G2.der file), see
DSi SD/MMC Firmware Certificate/Keys (DER)
The version.bin file contains the firmare version:

      000h 2    Major Version (0001h)                       (eg. 1)
      002h 2    Minor Version (0000h..0004h)                (eg. 4)
      004h 1Ch  Version/Region string in UTF-16, zeropadded (eg. "1.4.5E")

The Version/Region string is displayed in System Settings.
DSi Firmware Versions

      0.1    31 Jul 2008  Pre-release v0.1A (accidentally included in v1.0J)
      1.0    09 Sep 2008  Pre-installed v1.0J version (the actual file in v1.0J)
      1.0?   22 Oct 2008? First Update(??) to Japanese Region DSi System Menu
      1.1?   ?            dsibrew:NoneSuch?, wikipedia:Preinstalled1stJpnVersion??
      1.2    18 Dec 2008  Second Update to Japanese Region DSi System Menu
      1.3    03 Apr 2009  Launch Day (USA, EUR, AUS), new "start DSi Camera" button
      1.4    29 Jul 2009  Blocks NDS flashcarts, Facebook support to share photos
      1.4.1  07 Sep 2010  Blocks more NDS flashcarts
      1.4.2  10 May 2011  Blocks DSiWare exploits on SD card (sudokuhax etc.)
      1.4.3  29 Jun 2011  Blocks more NDS flashcarts (only whitelist was updated)
      1.4.4  21 Mar 2012  Blocks DSi cart exploits (CookingCoach/ClassicWordGames)
      1.4.5  11 Dec 2012  Blocks more NDS flashcards

JAP region launched first (unknown if there was any pre-installed version prior to the v1.0 update (or if v1.0 was really released as "update" at all), unknown if v1.1 did also exist).
USA/EUR/AUS regions launched on 03 Apr 2009 (so only v1.3 and up exist as update?; but they had an older version pre-installed: v1.2U is known to exist).
CHN region launched on 11 Sep 2010 with firmware v1.4.2C (or more probably with v1.4.1C pre-installed?).
KOR region launched at unknown date (probably near chinese launch date) (korean v1.4.1K is known to exist).
CHN and KOR do have version numbers one step higher than normal regions (ie. v1.4 through v1.4.5 are called v1.4.1 through v1.4.6 in china/korea).

DSi SD/MMC Firmware Nintendo DS Cart Whitelist File

FAT16:\title\0003000f\484e4841\content\00000001.app (aka NDS Cart Whitelist)
The NDS Cart Whitelist contains checksums of all officially released licensed NDS cartridges (newer NDS Carts that aren't included in the list must contain extended NDS Cart Headers with RSA signatures).
That means, unlike the original NDS, the DSi refuses to boot any unlicensed/homebrew NDS software (though some "DSi compatible" FLASH carts are bypassing that restriction via exploits in licensed NDS games).
Below Whitelist example is from firmware v1.4E:

     Part 1 ("NDHT") is same in v1.0 through v1.4.5:
      00000h 4          ID "NDHT"                                                ;\
      00004h 80h        RSA-SHA1 on [00084h..286A7h]                             ;
      00084h 4          Number of titles (00000D76h) (=3446)                     ;
      00088h D76h*30h   Titles (30h bytes each, with two SHA1s)                  ;/
     Part 2 ("NDHX") is same in v1.4 through v1.4.5 (doesn't exist in v1.3):
      286A8h 4          ID "NDHX"                                                ;\
      286ACh 80h        RSA-SHA1 on [2872Ch..4AFBFh]                             ;
      2872Ch 4          Number of titles (000013BCh) (=5052)                     ;
      28730h 13BCh*1Ch  Titles (1Ch bytes each, only one SHA1)                   ;/
     Part 3 ("NDHI") differs in v1.4 versus v1.4.5 (doesn't exist in v1.3):
      4AFC0h 4          ID "NDHI"                                                ;\
      4AFC4h 80h        RSA-SHA1 on [4B044h..4B1B7h]                             ;
      4B044h 4          Number of titles (04h in v1.4E)    ;60h in v1.4.5E       ;
      4B048h 4*5Ch      Specials for A3TE,A6WE,YF7E,YOUF   ;210h on New3DS       ;/
     Footer:
      4B1B8h 13         Version String ("2832",0Dh,0Ah,"10619",0Dh,0Ah in v1.4E) ;\
      4B1C5h 11         Random garbage (padding to 10h-byte boundary)            ;/

The Version String at the end can be:

      00000000.app v1.0J   (at 286A8h) "2435",0Ah,"8325",0Ah          ;with LF's
      00000000.app v1.3U   (at 286A8h) "2435",0Ah,"8325",0Ah          ;with LF's
      00000001.app v1.4E   (at 4B1B8h) "2832",0Dh,0Ah,"10619",0Dh,0Ah ;with CRLF's
      0000000x.app v...    (?)
      00000006.app v1.4.5E (at 4D2C8h) "3067",0Ah,"11437",0Ah         ;with LF's
      0000000x.app v...    (?)
      0000000e.app New3DS  (at 56E08h) "3106",0Ah,"11437",0Ah         ;with LF's

BUG: The Whitelist's RSA signatures are NOT checked in firmware v1.4E (whilst other older/newer firmwares like 1.3U, 1.4.2E, and 1.4.5E are checking those signatures).
NDHT Title Structure (30h bytes each):

     This contains all NDS titles released prior to DSi firmware v1.0.
      Start Length  Description
      000h  4   Title ID (Gamecode)
      004h  4   Title version
      008h  20  Phase 1 SHA1-HMAC on 160h-byte cartheader and ARM9+ARM7 areas (?)
      01Ch  20  Phase 2 SHA1-HMAC on ARM9 Overlay and NitroFAT (zero if no overlay)

NDHX Title Structure (1Ch bytes each):

     This contains all NDS titles released prior to DSi firmware v1.4.
      000h  4   Title ID (Gamecode)
      004h  4   Title version
      008h  20  Phase 3 SHA1-HMAC on Icon/Title

NDHI Title Structure (5Ch bytes each):

     This contains extra checks for detecting hacked/exploited NDS titles.
      000h  4   Title ID (Gamecode)
      004h  4   Title version
      008h  8*8 Offset+Length for up to 8 regions (or 0,0=None)
      048h  20  Phase 4 SHA1-HMAC on above region(s)

The 40h-byte SHA1-HMAC keys are contained in Launcher (61h,BDh,DDh,72h,... for Phase 1+2, and 85h,29h,48h,F3h,... for Phase 3+4). The RSA key is also contained in Launcher (C7h,F4h,1Dh,27h,... for all Phases; though the RSA key is missing in firmwares where Nintendo forgot to implement the RSA check, eg. in v1.4E).
Example values for Metroid Demo ("AMFE"):

      41 4D 46 45 00 00 00 00                                     ;\
      95 9A B3 09 B7 4E AF 29 2E 97 61 B9 DC E9 5F FE 86 5C 91 4E ; NDHT
      D3 94 43 02 64 3A AF C5 D1 E1 3B C0 47 4A A2 98 AB 5D 71 8F ;/
      41 4D 46 45 00 00 00 00                                     ;\NDHX
      51 24 FE EF D4 3C 22 42 CC 17 13 0A 72 F8 FA 3B 4D 83 2A B1 ;/

Specials related to games:

      NTR-A3TE-USA = Tak: The Great Juju Challenge
      NTR-A6WE-USA = FIFA World Cup 2006
      NTR-YF7E-USA = Fish Tycoon
      NTR-YOUF-FRA = Samantha Oups!

Newer NDS Carts with RSA
NDS games released after DSi firmware v1.0 have RSA headers without Icon SHA1
NDS games released after DSi firmware v1.4 have RSA headers with Icon SHA1
Accordingly, NDS games released between DSi firmware v1.0 and v1.4 do have whitelist NDHX entries (for the icon), but don't need NDHT entries (since that's already covered by the RSA header).
Related carthdr flags are:

      cart[1BFh].bit6 = Cart Header RSA Signature exists
      cart[1BFh].bit5 = Cart Header has Icon SHA1 at [33Ch]
      cart[378h]      = SHA1 (same as whitelist Phase 1)
      cart[38Ch]      = SHA1 (same as whitelist Phase 2)
      cart[33Ch]      = SHA1 (same as whitelist Phase 3) (if above bit5=1)

DSi SD/MMC Camera Files - Overview

Photos/Frames
Photos can be taken via Nintendo DSi Camera utitilty (or alternately, directly via hotkeys in System Menu; which will be automatically flagging the photos with "Star" stickers, which will cause them to be shown as System Menu background image).
Frames are masks (with transparent pixels) that can be put onto photos. The Frames can be created via Nintendo DSi Camera utility (Camera, select Frame (upper-right Lens option), accept that Lens, then click Create Frame; the procedure then is to take a photo, and to rub-out pixels on touchscreen to make them transparent).
Internal/External Storage
The Camera is storing further data on the eMMC FAT12 partition:

      FAT12:\photo\DCIM\100NIN02\HNI_nnnn.JPG                        ;camera photos
      FAT12:\photo\private\ds\app\484E494A\pit.bin                   ;camera info
      FAT12:\photo\private\ds\app\484E494A\DCIM\100NIN02\HNI_nnnn.JPG;camera frames

Camera data can be copied to SD card (via Nintendo DSi Camera, Options, Copy):

      SD:\DCIM\nnnNIN02\HNI_nnnn.JPG                            ;camera photos
      SD:\private\ds\app\484E494A\pit.bin                       ;camera info
      SD:\private\ds\app\484E494A\DCIM\nnnNIN02\HNI_nnnn.JPG    ;camera frames

And, in internal eMMC only (not on SD), the DSi is somewhere storing Calendar entries (some sort of bitmaps with optional handwritten comments drawn via touchscreen).
File/Folder Numbers
The "nnnNIN02" folders are numbered "100NIN02" through "999NIN02". The first folder is usually 100NIN02, unless another "100xxxxx" folder did already exist (eg. if the SD card contains a "100CANON" folder, then DSi would start at 101NIN02 or higher).
The trailing "02" of the "nnnNIN02" folders appears to be fixed for DSi photos (folder name "nnnNIN01" is reserved for Wii screenshots).
The "HNI_nnnn.JPG" filenames are numbered "HNI_0001.JPG" through "HNI_0100.JPG", thereafter, the DSi will switch to next higher folder number, and wrap to using "HNI_0001.JPG" as first filename in that folder.
The weird "484E494A" folder name is based on the japanese Nintendo DSi Camera's gamecode (HNIJ) converted to an 8-digit uppercase HEX string (this appears to be always the japanese gamecode, even on european DSi consoles).

DSi SD/MMC Camera Files - JPEG's

Overall JPEG Format (big-endian)

      Offs   ID    Len   Data
      0000h  FFD8h                                      ;(start of image)    ;SOI
      0002h  FFE1h,10C4h,"Exif",00h,00h,<Exif Body>     ;(extra "Exif" data) ;APP1
      10C8h  FFC0h,0011h,08h,01E0h,0280h,03h,012100h,021101h,031101h         ;SOF0
      10DBh  FFDBh,0084h, 00 06 04 05 06 05 04 06 06 05 06 07 07 .. 28 28 28 ;DQT
      1161h  FFC4h,01A2h, 00 00 01 05 01 01 01 .. .. F8 F9 FA                ;DHT
      1305h  FFDAh,000Ch,03h,010002h,110311h,003F00h    ;(start of scan)     ;SOS
      1313h  E6 76 F4 DD 4F 0A 3B 60 0F 4C D7 9E 9A 93 3D 4B EE 98 B8 .. ..
      AB4Fh  FFD9h                                      ;(end of image)      ;EOI

Exif Body for Nintendo DSi Photos
The Exif data consists of several headers/footers and data blocks, mixed with several "IFD" tables.

      Offs  Siz  ExID  Type  Length    Offset    ;<-- Format for "IFD" Tables
      0000h 4    "MM",002Ah                      ;Big-Endian (aka Motorola)
      0004h 4    00000008h                       ;first IFD offset (IFD0)

IFD0 (Main Image):

      0008h 2    0009h                           ;number of IFD0 entries
      000Ah 12   010Fh,0002h,00000009h,0000007Ah ;Maker ("Nintendo",0)
      0016h 12   0110h,0002h,0000000Bh,00000084h ;Model ("NintendoDS",0)
      0022h 12   011Ah,0005h,00000001h,00000090h ;Resolution X (72 dpi)
      002Eh 12   011Bh,0005h,00000001h,00000098h ;Resolution Y (72 dpi)
      003Ah 12   0128h,0003h,00000001h,00020000h ;Resolution Unit (2=Inches)
      0046h 12   0131h,0002h,00000005h,000000A0h ;Firmware (Gamecode backwards)
      0052h 12   0132h,0002h,00000014h,000000A6h ;Date/Time Modified
      005Eh 12   0213h,0003h,00000001h,00020000h ;Subsampling (2=datum point)
      006Ah 12   8769h,0004h,00000001h,000000BAh ;Exif SubIFD offset
      0076h 4    000001DEh                       ;next IFD offset (IFD1)
      007Ah 9+1  "Nintendo",00h,00h              ;Maker ("Nintendo",0,0)
      0084h 11+1 "NintendoDS",00h,00h            ;Model ("NintendoDS",0,0)
      0090h      00000048h,00000001h             ;Resolution X (72 dpi)
      0098h      00000048h,00000001h             ;Resolution Y (72 dpi)
      00A0h 5+1  "PINH",00h,00h   ;aka HNIP      ;Firmware (Gamecode backwards)
      00A6h 20   "YYYY:MM:DD HH:MM:SS",00h       ;Date/Time Modified

Sub IFD:

      00BAh 2    000Ah                           ;number of Sub IFD entries
      00BCh 12   9000h,0007h,00000004h,30323230h ;Exif Version ("0220")
      00C8h 12   9003h,0002h,00000014h,00000138h ;Date/Time Original
      00D4h 12   9004h,0002h,00000014h,0000014Ch ;Date/Time Digitized
      00E0h 12   9101h,0007h,00000004h,01020300h ;Components (Y,Cb,Cr)
      00ECh 12   927Ch,0007h,00000042h,00000160h ;Maker dependent internal data
      00F8h 12   A000h,0007h,00000004h,30313030h ;Flashpix Version ("0100")
      0104h 12   A001h,0003h,00000001h,00010000h ;Color Space (1=Normal=sRGB)
      0110h 12   A002h,0004h,00000001h,00000280h ;Pixel Dimension X (640)
      011Ch 12   A003h,0004h,00000001h,000001E0h ;Pixel Dimension Y (480)
      0128h 12   A005h,0004h,00000001h,000001A2h ;Interoperability IFD (R98)
      0134h 4    00000000h                       ;next IFD offset (none)
      0138h 20   "YYYY:MM:DD HH:MM:SS",00h       ;Date/Time Original
      014Ch 20   "YYYY:MM:DD HH:MM:SS",00h       ;Date/Time Digitized

Maker dependent IFD (DSi specific):

      0160h 2    0002h                           ;number of IFD entries
      0162h 12   1000h,0007h,0000001Ch,0000017Eh ;DSi Signature (IV+MAC)
      016Eh 12   1001h,0007h,00000008h,0000019Ah ;DSi Whatever Zero (Frame info?)
      017Ah 4    00000000h                       ;next IFD offset (none)
      017Eh 12   2E AB A5 D1 FD A8 .. ..         ;DSi Signature (IV)  ;\
      018Ah 16   xx xx xx xx xx xx .. ..         ;DSi Signature (MAC) ;/
      019Ah 8    0000000000000000h               ;<-- different for Frames

Interoperability IFD (R98) (some common/useless stuff for JPEGs):

      01A2h 2    0003h                           ;number of IFD entries
      01A4h 12   0001h,0002h,00000004h,52393800h ;Stipulated File ("R98",0)
      01B0h 12   0002h,0007h,00000004h,30313030h ;Whatever ("0100")
      01BCh 12   1000h,0002h,00000012h,000001CCh ;Whatever (JPEG Exif Ver 2.2",0)
      01C8h 4    00000000h                       ;next IFD offset (none)
      01CCh 18   "JPEG Exif Ver 2.2",00h         ;Whatever (JPEG Exif Ver 2.2",0)

IFD1 (Thumbnail Image):

      01DEh 2    0006h                           ;number of IFD1 entries
      01E0h 12   0103h,0003h,00000001h,00060000h ;Compression (1=JPEG)
      01ECh 12   011Ah,0005h,00000001h,0000022Ch ;Resolution X (72 dpi)
      01F8h 12   011Bh,0005h,00000001h,00000234h ;Resolution Y (72 dpi)
      0204h 12   0128h,0003h,00000001h,00020000h ;Resolution Unit (2=Inches)
      0210h 12   0201h,0004h,00000001h,0000023Ch ;Jpeg Offset
      021Ch 12   0202h,0004h,00000001h,00000xxxh ;Jpeg Size (eg. E80h)
      0228h 4    00000000h                       ;next IFD offset (none)
      022Ch 8    00000048h,00000001h             ;Resolution X (72 dpi)
      0234h 8    00000048h,00000001h             ;Resolution Y (72 dpi)

Thumbnail Data (160x120pix, in JPEG Format):

      023Ch 2    FFD8h                           ;(start of thumbnail/image) ;SOI
      023Eh 13h  FFC0h,0011h,08h,0078h,00A0h,03h,012100h,021101h,031101h     ;SOF0
      0251h 86h  FFDBh,0084h, 00 0A 07 07 08 07 .. ..                        ;DQT
      02D7h 1A4h FFC4h,01A2h, 00 00 01 05 01 .. .. F8 F9 FA                  ;DHT
      047Bh 0Eh  FFDAh,000Ch,03h,010002h,110311h,003F00h   ;(start of scan)  ;SOS
      0489h ...  CC 55 14 F0 3D 2B 8B 4B 9D C2 E3 BD 18 A5 B0 09 B6 .. ..
      10xxh 2    FFD9h                           ;(end of thumbnail/image)   ;EOI

The above european gamecode entry differs for other regions. Above offsets are usually as so for DSi jpeg's, but they might change if Nintendo adds/removes some entries, or changes size of some entries (for example, the Model string is said to be different for 3DS, and "Frames" are including a bigger entry, as described below).
DSi Signature (IV+MAC)
The 1Ch-byte Signature is split into a 0Ch-byte IV value (this might be just a random number?), and a 10h-byte MAC value. The MAC is computed via AES-CCM:

      IV[00h..0Bh]  = First 0Ch-bytes of signature
      KEY[00h..0Fh] = Constant (70,88,52,06,...)   ;from BIOS ROM
      Zerofill the 1Ch-byte signature area in the JPEG file
      Probably zeropad(?) the JPEG file (if filesize isn't a multiple of 16 bytes)
      Pass the whole JPEG as "extra associated data" to the AES-CCM hardware
      Copy the IV value and computed MAC value back to the JPEG's signature area

Unknown if the IV value is just random, and unknown if there are further requirements (such like using same Maker/Model strings or same resolution as in original DSi files).
Locating "ldr rx,=927Ch" opcodes at various locations in Nintendo DSi Camera is easy; but the stuff is handled via numerous sub-functions, including IPC stuff with both ARM7 and ARM9 envolved; which isn't too easy to disassemble.
Exif Body for Nintendo DSi Frames
Frames are using same format above, but with the 8-byte zero entry at [019Ah] replaced by a bigger 8FCh-byte entry (accordingly, the size in IFD entry [016Eh] is also adjusted, and offsets for entries [01A2h..10xxh] are moved up).
The actual change is that 0000000000000000h is changed from 8 byte size to 8FCh-byte size, containing 0000000000000001h, followed by 8F4h extra bytes (with unknown content; maybe the frame mask for transparent pixels; the data doesn't really look like a mask though, unless it's compressed, but then the fixed size would be strange).
IFD Type Values (and Length/Offset)

      0001h = 8bit Unsigned
      0002h = 7bit ASCII
      0003h = 16bit Unsigned
      0004h = 32bit Unsigned
      0005h = 64bit Unsigned Rational (32bit numerator, plus 32bit denominator)
      0006h = Reserved
      0007h = 8bit General Purpose
      0009h = 32bit Signed
      000Ah = 64bit Signed Rational (32bit numerator, plus 32bit denominator)
      000Bh..FFFFh = Reserved

The "Length" value indicates the number of type units, eg. type=16bit, length=3 would mean 6 bytes. If the information fits into 4 bytes then it's stored directly in the 4-byte "Offset" field, otherwise "Offset" is a pointer to the actual information.

DSi SD/MMC Camera Files - pit.bin

FAT12:\photo\private\ds\app\484E494A\pit.bin (8K) (camera info)
SD:\private\ds\app\484E494A\pit.bin (47K) (camera info)

      0000h       8  ID ("0TIP00_1") (maybe meant to read as PIT01_00 or so)
      0008h       2  Number of pit.bin entries (3000 for SD Card) (500 for eMMC)
      000Ah       2  Unknown (0001h)
      000Ch       2  Next Photo Folder-Number minus 100  (xxxNIN02)
      000Eh       2  Next Photo File-Number minus 1      (HNB_0xxx.JPG)
      0010h       2  Next Frame Folder-Number minus 100  (xxxNIN02)
      0012h       2  Next Frame File-Number minus 1      (HNB_0xxx.JPG)
      0014h       2  CRC16 of whole file (with initial value 0000h, and with
                     entry [0014h] being treated as 0000h for calculation)
      0016h       2  Size of Header (0018h)
      0018h+N*10h 4  Entry N, Time/Date (seconds since 01 Jan 2000)
      001Ch+N*10h 8  Entry N, Unknown (zerofilled)
      0024h+N*10h 4  Entry N, Flags (see below)
                      0     Used Entry Flag (0=Unused/Deleted, 1=Used)
                      1-10  Folder-Number minus 100 (xxxNIN02)
                      11-17 File-Number minus 1     (0..99 = HNB_0001..0100.JPG)
                      18-19 Sticker (0=None, 1=Star, 2=Clover, 3=Heart)
                      20-21 Type (0,3=Photo, 1=Frame, 2=?)
                      22-23 Unknown (0,2=Normal?, 1=?, 3=Error)
                      24-31 Unused (zero)
      xxx8h       8  Padding for 16-byte filesize alignment (zerofilled)

The "Next Photo/Frame" entries contain File/Folder Numbers where the next images will be saved; that file numbers increase after saving, and do eventually wrap to next higher folder number.
The Nintendo DSi Camera utility shows only photos listed in "pit.bin", when manually copying jpg's to SD Card one could:

     - Delete "pit.bin" (it'll be recreated with ALL jpgs, sticker flags are lost)
     - Replace an existing 'listed' file by a new file with same filename
     - Manually edit "pit.bin" and adjust its CRC16 checksum

Photos are region free, can be viewed from any other DSi's (as long as they are listed in pit.bin). However, they do require some signature in Exif header, so in general, the DSi accepts only images that come from DSi consoles; not images from other sources.
Stickers
Photos with "Star" sticker are shown as background picture in System Menu; this works only for images stored in internal eMMC memory (images on SD Card can have stickers, too, but they are ignored by System Menu).

DSi SD/MMC Flipnote Files

FAT16:\title\00030004\4b4755gg\data\public.sav
This .sav file contains a FAT12 filesystem with following files:

      Flipnote(public.sav):\eula.txt     ;128 Kbytes, 20000h - zerofilled
      Flipnote(public.sav):\option.bin   ;256 bytes, 100h    - options
      Flipnote(public.sav):\mark0.pls    ;8000 bytes, 1F40h  - Heart sticker
      Flipnote(public.sav):\mark1.pls    ;8000 bytes, 1F40h  - Crown sticker
      Flipnote(public.sav):\mark2.pls    ;8000 bytes, 1F40h  - Music sticker
      Flipnote(public.sav):\mark3.pls    ;8000 bytes, 1F40h  - Skull sticker
      Flipnote(public.sav):\recent10.pls ;4000 bytes, FA0h   - Recently saved
      Flipnote(public.sav):\friend.pls   ;28800 bytes, 7080h - F7,A0,CD,zeroes..
      Flipnote(public.sav):\remind.pls   ;10240 bytes, 2800h - F7,A0,CD,zeroes..
      Flipnote(public.sav):\latest1.pls  ;256 bytes, 100h    - xxxxxxxx,zeroes..
      Flipnote(public.sav):\nand.pls     ;160000 bytes, 27100h - All files
      Flipnote(public.sav):\ugo\0NN\XNNNNN_NNNNNNNNNNNNN_NNN.ppm - flipnotes

Flipnote(public.sav):\option.bin (256 bytes, 100h)

      0000h 1   Unknown (02h)        (?)
      0001h 1   Stylus               (00h=Right Hand, 01h=Left Hand)
      0002h 1   Sound Effects        (00h=On, 01h=Off)
      0003h 1   Unknown (01h)        (?)
      0004h 1   Unknown (00h)        (?)
      0005h 1   Unknown (01h)        (?)
      0006h 1   Unknown (01h)        (?)
      0007h 1   Unknown (03h)        (?)
      0008h 1   Unknown (02h)        (?)
      0009h 1   Unknown (01h)        (?)
      000Ah 1   Unknown (00h)        (?)
      000Bh 1   Unknown (01h)        (?)
      000Ch 1   Advanced Tools       (00h=Off, 01h=On)
      000Dh 1   Pages to Trace       (01h..04h=1..4)
      000Eh 1   Frog Display         (01h=Off, 01h=On)
      000Fh 1   Start on Calendar    (00h=Off, 01h=On)
      0010h 8   Flipnote Studio ID   (64bit User ID) (fixed)
      0018h 2   Checksum             (see below)
      001Ah 2   Date of Birth, Year  (076Ch..0840h=1900..2112)
      001Bh 1   Date of Birth, Month (01h..0Ch=1..12)
      001Ch 1   Date of Birth, Day   (01h..1Fh=1..31)
      001Eh E2h Unknown/unused       (zerofilled)

Checksum is computed as "chk=0000h, halfword[18h]=0000h, for i=0 to FFh, chk=chk+(byte[i] xor i), next i, halfword[18h]=chk".
SD:\private\ds\app\4B4755GG\mark0.pls (Heart sticker), 8000 bytes (1F40h)
SD:\private\ds\app\4B4755GG\mark1.pls (Crown sticker), 8000 bytes (1F40h)
SD:\private\ds\app\4B4755GG\mark2.pls (Music sticker), 8000 bytes (1F40h)
SD:\private\ds\app\4B4755GG\mark3.pls (Skull sticker), 8000 bytes (1F40h)
SD:\private\ds\app\4B4755GG\recent10.pls (Recently saved), 4000 bytes (FA0h)
Recently saved files list, and four files with flipnotes that have "stickers" assigned to them (which can be done when clicking "Details" in the flipnote file menu).

      0000h   N*3Fh       List of filenames (if any)               ;\encrypted
      N*3Fh+0 1           End of filename list (00h)               ;/
      N*3Fh+1 2           Crippled MD5 checksum bytes [6,8]        ;\unencrypted
      N*3Fh+3 SIZ-N*3Fh-3 Padding to end of file (zerofilled)      ;/

The filenames are formatted as so (consisting of device, path, and name):

      "sdmc:/private/ds/app/4B4755GG/001/XNNNNN_NNNNNNNNNNNNN_NNN.ppm",0Ah

The files are encrypted using a fixed XOR pattern (repeated every 40h bytes):

      F7h,4Ch,6Ah,3Ah,FBh,82h,A6h,37h,6Eh,11h,38h,CFh,A0h,DDh,85h,C0h
      C7h,9Bh,C4h,D8h,DDh,28h,8Ah,87h,53h,20h,EEh,E0h,0Bh,EBh,43h,A0h
      DBh,55h,0Fh,75h,36h,37h,EBh,35h,6Ah,34h,7Fh,B5h,0Fh,99h,F7h,EFh
      43h,25h,CEh,A0h,29h,46h,D9h,D4h,4Dh,BBh,04h,66h,68h,08h,F1h,F8h

The checksum is derived by computing the MD5 checksum across the data bytes (in unencrypted form), and then crippling the 16-byte MD5 value to 2 bytes.
For example, an empty file contains only three bytes: F7h,A0h,CDh (plus zero padding).
SD:\private\ds\app\4B4755GG\001\dirmemo2.lst (files), 160000 bytes (27100h)

      0000h   N*1Dh       List of filenames (if any)               ;\encrypted
      N*1Dh+0 1           End of filename list (00h)               ;/
      N*1Dh+1 2           MD5 checksum bytes [6,8]                 ;\unencrypted
      N*1Dh+3 SIZ-N*1Dh-3 Padding to end of file (zerofilled)      ;/

The filenames are formatted as so (raw names, without path):

      "XNNNNN_NNNNNNNNNNNNN_NNN.ppm",0Ah

Checksum and encryption is same as for the ".pls" files, however, the ".lst" file contains only raw filenames (without path's).
SD:\private\ds\app\4B4755GG\gif\XNNNNN_NNNNNNNNNNNNN_NNN.gif
Flipnotes exported to GIF format. Supported are animated GIFs, and separate GIFs for each frame. There appears to be no way to view GIFs, or to convert them back to PPM format.
SD:\private\ds\app\4B4755GG\001\XNNNNN_NNNNNNNNNNNNN_NNN.ppm ;normal
SD:\private\ds\app\4B4755GG\YYYYMMDD\NNN\XNNNNN_NNNNNNNNNNNNN_NNN.ppm ;backup
Flipnotes animation files.

      0000h  4       File ID ("PARA")
      0004h  4       Size of Animation Data (vid)
      0008h  4       Size of Audio Data     (aud) (0=none)
      000Ch  2       Number of Frames minus 1    (NF-1)
      000Eh  2       Unknown (always 24h,00h)
      0010h  2       Lock Flag (0=Open, 1=Locked, prevent editing)
      0012h  2       Preview frame number
      0014h  22      Nickname of Original Author (UCS-2)  ;\max 10 characters
      002Ah  22      Nickname of Last Editor     (UCS-2)  ; (plus ending zero)
      0040h  22      Nickname of User (?)        (UCS-2)  ;/
      0056h  8       User ID of Original Author  (Flipnote Studio ID)
      005Eh  8       User ID of Last Editor      (Flipnote Studio ID)
      0066h  18      Filename of Original File   (3xHEX, 13xASCII, 2xVER)
      0078h  18      Filename of Current File    (3xHEX, 13xASCII, 2xVER)
      008Ah  8       User ID of Previous Editor  (Flipnote Studio ID)
      0092h  8       Filename Fragment           (3xHEX, 5xHEX)
      009Ah  4       Time/Date (seconds since 1st Jan 2000)
      009Eh  2       Zerofilled
      00A0h  600h    Preview Bitmap (8x6 tiles, aka 64x48 pixels, 4bpp)
      06A0h  2       Size of Animation Table (4*NF)
      06A2h  4       Zerofilled
      06A6h  2       Flags (bit0=Can be set?, bit1=Loop/Repeat, bit6=Set?)
      06A8h  4*NF    Animation Table (offsets in Animation Data for each frame)
      ...    (vid)   Animation Data Frame(s)
      ...    1*NF    Audio Flags for each Frame (bit0-2: Effect 1-3, bit3-7: Zero)
      ...    ..      Padding (0..3 bytes zerofilled, for alignment of next entry)
      ...    4       Size of Background music in bytes (0=not used/empty)
      ...    4       Size of Sound effect #1 in bytes (0=not used/empty, max 2000h)
      ...    4       Size of Sound effect #2 in bytes (0=not used/empty, max 2000h)
      ...    4       Size of Sound effect #3 in bytes (0=not used/empty, max 2000h)
      ...    1       Framespeed for playback          (1..8) aka "8 minus N"
      ...    1       Framespeed when BGM was recorded (1..8) aka "8-decimal"
      ...    14      Zerofilled
      ...    (aud)   Audio Data (BGM, followed by Effects 1, 2, 3) (if any)
      ...    80h     RSA-OpenPGP-SHA1 across all preceeding bytes
      ...    10h     Zerofilled

The RSA signature is in OpenPGP SHA1 format (as used by SWI 23h, however Flipnote is using it's own RSA functions instead of the BIOS SWIs). The RSA public/private keys are contained in the Flipnote executable (in the modcrypted area).
Animation Data Frame(s)

      Start  Length  Description
      0000h  1       Pen and Paper information
      0001h  48      Layer 1 Line Encoding (48 bytes = 2bit per 192 lines)
      0031h  48      Layer 2 Line Encoding (48 bytes = 2bit per 192 lines)
      0061h  ...     Frame Data for Layer 1
      ...    ...     Frame Data for Layer 2

The pen and paper byte at the start is encoded as follows:

      0    Paper     (0=Black, 1=White)
      1-2  Layer 1   (0=None, 1=Inverse of Paper, 2=Red, 3=Blue)
      3-4  Layer 2   (0=None, 1=Inverse of Paper, 2=Red, 3=Blue)
      5-6  Unknown
      7    New Frame (0=Change between last frame, 1=Totally new frame)

The Line Encoding contains 2bit values for all 192 scanlines (starting with bit0-1 of the first byte; for the top-most(?) scanline). The meaning of the 2bit values is:

      0 = Skip Line    (0 bytes)   (0 pixels)
      1 = Packed Line  (4+N bytes) (32bit flags, plus Nx8 pixels)
      2 = Inverse Line (4+N bytes) (32bit flags, plus Nx8 inverted pixels)
      3 = Raw Line     (32 bytes)  (256 pixels)

The packed lines contain a 32bit header (with flags for each 8-pixel fragment of the line, bit31 being the left-most fragment), followed by data bytes for each flagged fragment (with 8 pixels per fragment, bit0 being the left-most pixel). The Inverse lines have the same 32bit flags, but for whatever reason, the following data byte(s) are to be XORed with FFh.
Audio Data

      First comes the BGM (if used)
      Then comes sound effect #1 (if used)
      Then comes sound effect #2 (if used)
      Then comes sound effect #3 (if used)

The sound data seems to be a variant of VOX ADPCM at around 8KHz.
IDs and Filenames
Half of the Flipnote Studio ID is same as the last 4 bytes of the wifi MAC address. The filenames are also containing the last 3 bytes of the MAC address. The "XNNNNN_NNNNNNNNNNNNN_NNN.ppm" filename is also encoded in three header entries:

      Header  = Filename      = Meaning
      3xHEX   = XNNNNN        = Based on MAC address (the "X" in "XNNNNN" is what?)
      13xASCII= NNNNNNNNNNNNN = Some 13-digit random number or so as ASCII string
      5xHEX   = NNNNNNNNNN    = First 10-digits of above 13-digit string
      2xVER   = NNN.ppm       = Trailing version(?) number (hex, decimal?)

For the file name "G35B20_0909841CDBEB1_002.ppm":

                       <-hex--> <-----ascii-----------------> <-asc--> <-n->
      Filename (ori)   D3 5B 20 30 39 30 39 38 34 31 43 44 42 45 42 31 00 00
      Filename (curr)  D3 5B 20 30 39 30 39 38 34 31 43 44 42 45 42 31 02 00
                       <-hex--> <--hex------->
      Filename (frag)  D3 5B 20 09 09 84 1C DB

Preview Palette (fixed)
Fullscreen flipnotes can have only four colors: Black, White, Red, Blue). Additional shades like gray, magenta, or dark/light colors exist only in resampled preview images. The Preview List uses pale colors, with higher contrast for the Selected icon.

      Color  Purpose    (appearance)  Preview   Selected
      00h    N/A       (transparent)  1F-1F-1F  1F-1F-1F
      01h    Black       (dark grey)  13-13-13  0A-0A-0A
      02h    White           (white)  1F-1F-1F  1F-1F-1F
      03h    White+Black      (grey)  19-19-19  13-13-13
      04h    Red               (red)  1F-12-12  1F-09-09
      05h    Red+Black    (dark red)  1B-13-13  18-0A-0A
      06h    Red+White        (pink)  1F-19-19  1F-15-15
      07h    N/A             (green)  0E-1F-0E  02-1F-02
      08h    Blue             (blue)  12-12-1F  09-09-1F
      09h    Blue+Black  (dark blue)  13-13-1A  0A-0A-16
      0Ah    Blue+White (light blue)  19-19-1F  15-15-1F
      0Bh    N/A             (green)  0E-1F-0E  02-1F-02
      0Ch    Red+Blue      (magenta)  1A-13-1A  16-0B-16
      0Dh    N/A             (green)  0E-1F-0E  02-1F-02
      0Eh    N/A             (green)  0E-1F-0E  02-1F-02
      0Fh    N/A             (green)  0E-1F-0E  02-1F-02

FAT12:\photo\DCIM\100NIN02\HNI_nnnn.JPG ;camera photos
Flipnote doesn't contain an own camera function. However, the drawing utility does allow to import JPGs from the camera partition (ie. images that have been previously taken via the DSi Camera utility).

DSi Atheros Wifi SDIO Interface

AR6002 SDIO Registers
DSi Atheros Wifi SDIO Function 0 Register Summary
DSi Atheros Wifi SDIO Function 1 Register Summary
DSi Atheros Wifi - SDIO Function 1 I/O - mbox_wlan_host_reg
DSi Atheros Wifi Misc
For general info about SDIO protocol and I/O ports, and SDIO Function 0, see
DSi SD/MMC Protocol and I/O Ports
Transfer Protocol (Commands/Events)
DSi Atheros Wifi - Command Summary
DSi Atheros Wifi - Response Summary
DSi Atheros Wifi - Host Interest Area in RAM
DSi Atheros Wifi - BMI Bootloader Commands
DSi Atheros Wifi - MBOX Transfer Headers
DSi Atheros Wifi - WMI Misc Commands
DSi Atheros Wifi - WMI Misc Events
DSi Atheros Wifi - WMI Connect Functions
DSi Atheros Wifi - WMI Channel and Cipher Functions
DSi Atheros Wifi - WMI Scan Functions
DSi Atheros Wifi - WMI Bit Rate Functions
DSi Atheros Wifi - WMI Threshold Functions
DSi Atheros Wifi - WMI Error, Retry and Debug Functions
DSi Atheros Wifi - WMI Priority Stream Functions
DSi Atheros Wifi - WMI Roam Functions
DSi Atheros Wifi - WMI Power Functions
DSi Atheros Wifi - WMI Statistics Function
DSi Atheros Wifi - WMI Bluetooth Coexistence (older AR6002)
DSi Atheros Wifi - WMI Wake on Wireless (WOW) Functions
DSi Atheros Wifi - WMI General Purpose I/O (GPIO) Functions
Additional WMI Functions (NOT implemented in DSi with AR6002, but maybe exist in DSi/3DS with AR6013/AR6014):
DSi Atheros Wifi - Unimplemented WMI Misc Functions
DSi Atheros Wifi - Unimplemented WMI Bluetooth Coexistence (newer AR6002)
DSi Atheros Wifi - Unimplemented WMI Bluetooth Coexistence (AR6003)
DSi Atheros Wifi - Unimplemented WMI DataSet Functions
DSi Atheros Wifi - Unimplemented WMI AP Mode Functions (exists on 3DS)
DSi Atheros Wifi - Unimplemented WMI DFS Functions
DSi Atheros Wifi - Unimplemented WMI P2P Functions
DSi Atheros Wifi - Unimplemented WMI WAC Functions
DSi Atheros Wifi - Unimplemented WMI RF Kill and Store/Recall Functions
DSi Atheros Wifi - Unimplemented WMI THIN Functions
DSi Atheros Wifi - Unimplemented WMI Pyxis Functions
Aside from WMI Commands/Events, it should be obviously also possible to transfer actual data packets, but unknown to do that... maybe it's done through MBOX0 too, and maybe related to WMI_DATA_HDR, WMI_TX_META_V0..3, WMI_RX_META_V0..2 in "wmi.h" and/or to stuff in "htc.h".
DSi Atheros Wifi I2C EEPROM

DSi Atheros Wifi SDIO Function 0 Register Summary

Atheros SDIO "Function 0" area

      0:00000 2      Revision       (0011h = CCCRv1.10, SDIOv1.10, SDv1.01)  ;\
      0:00002 2      Function       (0202h = Function 1 enabled/ready)       ;
      0:00004 2      Interrupt Flags(0000h = None enabled/pending)           ;
      0:00006 1      Abort/Reset    (00h)                                    ;
      0:00007 1      Bus Interface  (82h = 4bit mode, pulldown=off)          ;
      0:00008 1      Card Capability(17h)                                    ; CCCR
      0:00009 3      CIS0 Pointer   (001000h = CIS0 at 0:01000h)             ;
      0:0000C ..       ..suspend..? (zero-filled)                            ;
      0:00010 2      Block Size     (0000h = Function 0 Block Size, variable);
      0:00012 1      Power Control  (03h = supports/uses more than 720mW)    ;
      0:00013 2      Bus Speed      (0000h = Supports only SDR12)            ;
      0:00015 1      Driver Strength(00h)                                    ;
      0:00016 1      Interrupt Ext  (00h = No aysnc IRQ support in 4bit mode);
      0:00017 E9h    Reserved       (zero-filled)                            ;/
      0:00100 2      Interface Type (0000h=Not SDIO standard, no CSA)        ;\
      0:00102 1      Power          (00h=No power selection)                 ;
      0:00103 6      Reserved       (zero-filled)                            ;
      0:00109 3      CIS1 Pointer   (001100h = CIS1 at 0:01100h)             ; FBR1
      0:0010C 4      CSA Stuff      (zero-filled, CSA isn't supported)       ;
      0:00110 2      Block Size     (0080h = Function 1 Block Size, variable);
      0:00112 EEh    Reserved       (zero-filled)                            ;/
      0:00200 600h   FBR2..FBR7     (zero-filled)                            ;-FBRn
      0:00800 800h   Reserved       (zero-filled)                            ;-N/A
      0:01000         01 03 D9 01 FF    ;DEVICE (D9h=FUNCSPEC,01h=Siz,FFh=End;\
      0:01005         20 04 71 02 00 02 ;MANFID (0271h=Atheros, 0200h=AR6002);
      0:0100B         21 02 0C 00       ;FUNCID (0Ch,00h=Standard for SDIO)  ;
      0:0100F         22 04 00 00 08 32 ;FUNCE (0800h=MaxBlkSiz,32h=25Mbit/s); CIS0
      0:01015         1A 05 01 01 00 02 07            ;\       ;CONFIG       ;
      0:0101C         1B 08 C1 41 30 30 FF FF 32 00   ; PROM?  ;CFTABLE_ENTRY;
      0:01026         14 00                           ; RAM?   ;NO_LINK      ;
      0:01028..01044  FF-filled (1Dh bytes) ;uh?      ;/       ;END          ;
      0:01045..010FF  00-filled (BBh bytes) ;unused                          ;/
      0:01100         20 04 71 02 00 02 ;MANFID (0271h=Atheros, 0200h=AR6002);\
      0:01106         21 02 0C 00     ;FUNCID (0Ch,00h=Standard for SDIO)    ;
      0:0110A         22 2A 01        ;FUNCE                                 ;
      0:0110D          01 11          ;FUNCE WakeUpSupport(01h), v1.1(11h)   ;
      0:0110F          00 00 00 00    ;FUNCE Serial Number (00000000h=None)  ;
      0:01113          00 00 00 00 00 ;FUNCE CSA Stuff (00000000h,00h=None)  ;
      0:01118          00 08          ;FUNCE Max Block Size (0800h)          ; CIS1
      0:0111A          00 00 FF 80    ;FUNCE OCR (80FF0000h)                 ;
      0:0111E          00 00 00       ;FUNCE Operate Min/Avg/Max (00,00,00)  ;
      0:01121          00 01 0A       ;FUNCE Standby Min/Avg/Max (00,01,0A)  ;
      0:01124          00 00 00 00    ;FUNCE Bandwidth Min/Opt (0000h,0000h) ;
      0:01128          00 00          ;FUNCE Timeout Enable-till-Rdy (0000h) ;
      0:0112A          00 00 00 00    ;FUNCE Operation  Avg/Max (0000h,0000h);
      0:0112E          00 01 00 01    ;FUNCE HighCurrentAvg/Max (0100h,0100h);
      0:01132          00 01 00 01    ;FUNCE LowCurrent Avg/Max (0100h,0100h);
      0:01136         80 01 06        ;VENDOR                                ;
      0:01139         81 01 07        ;VENDOR                                ;
      0:0113C         82 01 DF        ;VENDOR                                ;
      0:0113F         FF              ;END                                   ;
      0:01140         01              ;Garbage?                              ;
      0:01141..011FF  00-filled (BFh bytes) ;unused                          ;/
      0:01200..02FFF  mirrors of 01000h..011FFh (CIS0 and CIS1) (1E00h bytes);\N/A
      0:03000..       00-filled (.... bytes) ;unused... reserved             ;/

Briefly

      0:00000         11 00 02 02 00 00 00 82  17 00 10 00 00 00 00 00  ;\
      0:00010         00 00 03 00 00 00 00                              ;
      0:00017..000FF  unused (zerofilled)                               ;/
      0:00100         00 00 00 00 00 00 00 00  00 00 11 00 00 00 00 00  ;\
      0:00110         80 00                                             ;
      0:00112..00FFF  unused (zerofilled)                               ;/
      0:01000         01 03 D9 01 FF                          ;\
      0:01005         20 04 71 02 00 02       ;hif.h: 271h    ;
      0:0100B         21 02 0C 00                             ;
      0:0100F         22 04 00 00 08 32                       ;
      0:01015         1A 05 01 01 00 02 07            ;\      ;
      0:0101C         1B 08 C1 41 30 30 FF FF 32 00   ; PROM? ;
      0:01026         14 00                           ; RAM?  ;
      0:01028..01044  FF-filled (1Dh bytes) uh?       ;/      ;
      0:01045..010FF  00-filled                               ;/
      0:01100         20 04 71 02 00 02                       ;\
      0:01106         21 02 0C 00                             ;
      0:0110A         22 2A 01 01 11 00  00 00 00 00  00 00 00 00  00 08 00 00
      0:0111C               FF 80 00 00  00 00 01 0A  00 00 00 00  00 00 00 00
      0:0112C               00 00 00 01  00 01 00 01  00 01
      0:01136         80 01 06                                ;
      0:01139         81 01 07                                ;
      0:0113C         82 01 DF                                ;
      0:0113F         FF 01 00                                ;
      0:01142..011FF  00-filled                               ;/
      0:01200..02FFF  mirrors of 01000..011FF (common cis and function 1 cis) ?
      0:03000..       00-filled

DSi Atheros Wifi SDIO Function 1 Register Summary

Atheros SDIO "Function 1" area

      1:00000..000FF  Mbox0 (100h bytes) <--DMA----------> Internal 256MB
      1:00100..001FF  Mbox1 (100h bytes) <--DMA----------> Internal 256MB
      1:00200..002FF  Mbox2 (100h bytes) <--DMA----------> Internal 256MB
      1:00300..003FF  Mbox3 (100h bytes) <--DMA----------> Internal 256MB
      1:00400..005FF  Control Registers  <--WINDOW_DATA--> Internal 256MB
      1:00600..007FF  CIS Window; Window ---huh???-------> Internal 256MB ???
      1:00800..00FFF  Mbox0 Alias (bigger 800h bytes alias)
      1:01000..017FF  Mbox1 Alias (bigger 800h bytes alias)
      1:01800..01FFF  Mbox2 Alias (bigger 800h bytes alias)
      1:02000..027FF  Mbox3 Alias (bigger 800h bytes alias)
      1:02800..03FFF  Extra Mbox0 Alias "for future usage" (1800h bytes)
      1:04000..1FFFF  Unspecified

mbox_wlan_host_reg.h -- in SDIO Function 1 address space

      1:00000h 100h    Mbox0 (100h bytes) <--DMA----------> Internal 256MB
      1:00100h 100h    Mbox1 (100h bytes) <--DMA----------> Internal 256MB
      1:00200h 100h    Mbox2 (100h bytes) <--DMA----------> Internal 256MB
      1:00300h 100h    Mbox3 (100h bytes) <--DMA----------> Internal 256MB
      1:00400h 1       HOST_INT_STATUS    (R)
      1:00401h 1       CPU_INT_STATUS     (R/W)
      1:00402h 1       ERROR_INT_STATUS   (R/W)
      1:00403h 1       COUNTER_INT_STATUS (R)
      1:00404h 1       MBOX_FRAME         (R)
      1:00405h 1       RX_LOOKAHEAD_VALID (R)
      1:00406h 1       HOST_INT_STATUS2             ;\GMBOX related, hw4/hw6 only
      1:00407h 1       GMBOX_RX_AVAIL               ;/
      1:00408h 1x4     RX_LOOKAHEAD0[0..3] (R)
      1:0040Ch 1x4     RX_LOOKAHEAD1[0..3] (R)
      1:00410h 1x4     RX_LOOKAHEAD2[0..3] (R)
      1:00414h 1x4     RX_LOOKAHEAD3[0..3] (R)
      1:00418h 1       (HOST_)INT_STATUS_ENABLE  (R/W)
      1:00419h 1       CPU_INT_STATUS_ENABLE     (R/W)
      1:0041Ah 1       ERROR_(INT_)STATUS_ENABLE (R/W)
      1:0041Bh 1       COUNTER_INT_STATUS_ENABLE (R/W)
      1:0041Ch 1x4     PAD1                 (FFh,6Eh,D7h,BFh - maybe some mirror?)
      1:00420h 1x8     COUNT[0..7]         (R/W)
      1:00428h 1x24    PAD2
        00428h 4       -   (mirror of 1:00468h?)
        0042Ch 4       -   (mirror of 1:0041Ch?)
        00430h 4       -   (mirror of 1:00410h?)
        00434h 4       -   (mirror of 1:00...h?)
        00438h 4       -   (mirror of 1:00468h?)
        0043Ch 4       -   (mirror of 1:0041Ch?)
      1:00440h 4x8     COUNT_DEC[0..7]     (R, or Write=any)
      1:00460h 1x8     SCRATCH[0..7]       (R/W)
      1:00468h 1       FIFO_TIMEOUT        (R/W)
      1:00469h 1       FIFO_TIMEOUT_ENABLE (R/W)
      1:0046Ah 1       DISABLE_SLEEP       (R/W)
      1:0046Bh 1x3     -
      1:0046Eh 1       LOCAL_BUS_ENDIAN    (R/W) (AR6001 only, not hw2/hw4/hw6)
      1:0046Fh 1       -
      1:00470h 1       LOCAL_BUS           (R and R/W)
      1:00471h 1x1     PAD4
      1:00472h 1       INT_WLAN            (R/W)
      1:00473h 1x1     PAD5
      1:00474h 4       WINDOW_DATA         (R/W)    ;\
      1:00478h 4       WINDOW_WRITE_ADDR   (W)      ;
      1:0047Ch 4       WINDOW_READ_ADDR    (W)      ;/
      1:00480h 1       HOST_CTRL_SPI_CONFIG (R/W)
      1:00481h 1       HOST_CTRL_SPI_STATUS (R/W)
      1:00482h 1       NON_ASSOC_SLEEP_EN ;hw2/hw4/hw6 (but didn't exist on AR6001)
      1:00483h 1       CPU_DBG_SEL                    ;\DBG, hw4/hw6 only
      1:00484h 1x4     CPU_DBG[0..3]                  ;/
      1:00488h 1       (HOST_)INT_STATUS2_ENABLE (R/W);\
      1:00489h 1x7     PAD6                           ; GMBOX related, hw4/hw6 only
      1:00490h 1x8     GMBOX_RX_LOOKAHEAD[0..7]       ;
      1:00498h 1       GMBOX_RX_LOOKAHEAD_MUX         ;/
      1:00499h 1x359   PAD7
      1:00600h 1x512   CIS_WINDOW[0..511]   (R/W?!)       ;SDIO 0:01000h..0:011FFh
      1:00800h 800h    Mbox0 Alias (bigger 800h bytes alias)
      1:01000h 800h    Mbox1 Alias (bigger 800h bytes alias)
      1:01800h 800h    Mbox2 Alias (bigger 800h bytes alias)
      1:02000h 800h    Mbox3 Alias (bigger 800h bytes alias)
      1:02800h 1800h   Extra Mbox0 Alias "for future usage" (1800h bytes)
      1:04000h 1C000h  Unspecified

DSi Atheros Wifi - SDIO Function 1 I/O - mbox_wlan_host_reg

Differences between hw2 versus hw4/hw6 (hw4 and hw6 are exactly same):

      added several new "GMBOX" registers (hw4/hw6)
      added new CPU_DBG registers (hw4/hw6)
      added three new "UART_HCI_FRAMER_xxx" error bits (hw4/hw6)
      renamed "DRAGON_INT" (hw2) to "INT" (hw4/hw6)
      renamed "SPI_xxx" (hw2) to "HOST_CTRL_SPI_xxx" (hw4/hw6)

1:00000h..000FFh - Mbox0 (100h bytes)
1:00100h..001FFh - Mbox1 (100h bytes)
1:00200h..002FFh - Mbox2 (100h bytes)
1:00300h..003FFh - Mbox3 (100h bytes)
1:00800h..00FFFh - Mbox0 Alias (bigger 800h bytes alias)
1:01000h..017FFh - Mbox1 Alias (bigger 800h bytes alias)
1:01800h..01FFFh - Mbox2 Alias (bigger 800h bytes alias)
1:02000h..027FFh - Mbox3 Alias (bigger 800h bytes alias)
1:02800h..03FFFh - Extra Mbox0 Alias "for future usage" (1800h bytes)
The MBOXes are some sort of FIFOs for transferring data blocks to/from wifi controller. Transfer end seems to be indicated by reading/writing the LAST byte (eg. when sending 4 bytes via Mbox0, data would be usually written to increasing addresses at 1:000FCh..000FFh, or 1:00FFCh..00FFFh when using the bigger Mbox alias) (technically, those addresses are just mirrors of each other, so one could as well write all bytes to the same address, or to random addresses at 1:00000h..000FFh and/or 1:00800h..00FFFh in no specific order; the only special case is that the last byte at 1:000FFh/1:00FFFh seems to be triggering something... like maybe throwing an IRQ at remote side or so).
In total, there appear to be eight MBOXes for SDIO: Four TXFIFOs (from SDIO to Xtensa side), plus four RXFIFOs (from Xtensa to SDIO side). The capacity of the FIFOs is unknown; the 800h-byte spaces would suggest 800h bytes, but the firmware uploader seems to use only max 200h bytes for whatever reason. Hardware tests suggest only 80h bytes MBOX1-3 TXFIFOs, and 8Ah or 3CD0h bytes for MBOX0 TXFIFO (8Ah when writing LAST bytes, 3CD0h otherwise); that results may be disturbed by the firmware trying to process incoming data.
Reading from EMPTY FIFO keeps returning the most recently read value (the last byte before the FIFO got empty).
Writes to FULL FIFO... results are unknown... maybe ignored, and/or producing TIMEOUTs?
1:00400h - HOST_INT_STATUS (R)
1:00418h - (HOST_)INT_STATUS_ENABLE (R/W)
Status.read: 0=No IRQ, 1=IRQ
Enable.read/write: 0=Disable, 1=Enable

      0-3    MBOX_DATA  MBOX0..3 Data pending (RX FIFO not empty)
      4      COUNTER    Secondary IRQ from COUNTER_INT_STATUS
      5      INT        Copy of internal CPU's interrupt line (aka DRAGON_INT)
      6      CPU        Secondary IRQ from CPU_INT_STATUS
      7      ERROR      Secondary IRQ from ERROR_INT_STATUS

The status register is read-only (to reset the status bits: read/reset the corresponding MBOXes, or acknowledge the corresponding Secondary IRQ sources).
1:00401h - CPU_INT_STATUS (R/W)
1:00419h - CPU_INT_STATUS_ENABLE (R/W)
Status.read: 0=No IRQ, 1=IRQ
Status.write: 0=No change, 1=Acknowledge
Enable.read/write: 0=Disable, 1=Enable

      0-7    BIT        Interrupt 0..7 from internal CPU

These bits are eight general purpose IRQ signals from the internal CPU (the meaning of the bits depends on software/firmware) (see WLAN_INT_HOST).
1:00402h - ERROR_INT_STATUS (R/W)
1:0041Ah - ERROR_(INT_)STATUS_ENABLE (R/W)
Status.read: 0=No IRQ, 1=IRQ
Status.write: 0=No change, 1=Acknowledge (except bit3)
Enable.read/write: 0=Disable, 1=Enable (except bit3)

      0      TX_OVERFLOW  (host tried to write to a full MBOX)
      1      RX_UNDERFLOW (host tried to read from an empty MBOX)
      2      WAKEUP (client has entered ON-state)
      3      SPI Error Interrupt   ;STATUS only (not STATUS_ENABLE)  (R)
      4      hw4/hw6: UART_HCI_FRAMER_UNDERFLOW             ;\
      5      hw4/hw6: UART_HCI_FRAMER_OVERFLOW              ; hw4/hw6 only
      6      hw4/hw6: UART_HCI_FRAMER_SYNC_ERROR            ;/
      7      -

Bit3 can be acknowledged or disabled only via SPI-specific registers from SPI host (that is, probably referring to the HOST_CTRL_SPI_CONFIG and HOST_CTRL_SPI_STATUS registers).
1:00403h - COUNTER_INT_STATUS (R)
1:0041Bh - COUNTER_INT_STATUS_ENABLE (R/W)
Status.read: 0=No IRQ, 1=IRQ
Enable.read/write: 0=Disable, 1=Enable

      0-7    COUNT[0..7] is nonzero

The status register is read-only (to reset the status bits: decrease the COUNT values via COUNT_DEC[0..7]) (unknown if directly writing to COUNT[0..7] does also affect the interrupt bits; probably it does, although official specs suggests that only 00h <--> 01h transitions affect IRQ bits).
1:00406h - HOST_INT_STATUS2 - hw4/hw6 only
1:00488h - (HOST_)INT_STATUS2_ENABLE (R/W) - hw4/hw6 only

      0      hw4/hw6: GMBOX_DATA                            ;\
      1      hw4/hw6: GMBOX_TX_OVERFLOW                     ; hw4/hw6 only
      2      hw4/hw6: GMBOX_RX_UNDERFLOW                    ;/
      3-7    -

1:00404h - MBOX_FRAME (R)

      0-3    MBOX0..3 contains a SOM (start of message) byte in RX FIFO (1=Yes)
      4-7    MBOX0..3 contains a EOM (end of message) byte in RX FIFO   (1=Yes)

Note: A SOM byte always follows an EOM byte from the previous message.
1:00405h - RX_LOOKAHEAD_VALID (R)

      0-3    MBOX0..3 contains at least 4 bytes in RX FIFO (1=Yes)
      4-7    -

1:00407h - GMBOX_RX_AVAIL - hw4/hw6 only

      0-6    hw4/hw6: BYTE                                  ;-hw4/hw6 only
      7      -

uh, a "7bit-byte"? ... or maybe "number of bytes"?
1:00408h..0040Bh - RX_LOOKAHEAD0[0..3] (R)
1:0040Ch..0040Fh - RX_LOOKAHEAD1[0..3] (R)
1:00410h..00413h - RX_LOOKAHEAD2[0..3] (R)
1:00414h..00417h - RX_LOOKAHEAD3[0..3] (R)

      0-7    MBOX RX FIFO Head-3 byte   ;\what is that?
      8-15   MBOX RX FIFO Head-2 byte   ; head "minus" N, or maybe
      16-23  MBOX RX FIFO Head-1 byte   ;/head "plus index" N?
      24-31  MBOX RX FIFO Head byte

Allows to preview the first 1..4 byte(s) from MBOX0..3, without removing the data from the FIFO. The first byte is valid when HOST_INT_STATUS indicates FIFO not empty. The first four bytes are valid when RX_LOOKAHEAD_VALID indicates at least 4 bytes in FIFO.
1:00420h..00427h - COUNT[0..7] (R/W)
This are eight 8bit counter registers for communicating with internal CPU (see LOCAL_COUNT and COUNT_INC in internal I/O map).

      0-7    Credit Counter Value

1:00440h..0045Fh - COUNT_DEC[0..7] (R, or Write=any)
This are eight 32bit registers. Reading or writing the LSB of the 32bit values does decrement the correspondig COUNT register by one. The written value is ignored, reading returns the old COUNT value (before decrement). The decrement doesn't occur if the COUNT is already zero. The corresponding IRQ bit is cleared when COUNT becomes zero.

      0-7    Credit Counter Value
      8-31   Zero? (dummy padding for 32bit access)

1:00460h..00467h - SCRATCH[0..7] (R/W)
This are eight 8bit general-purpose registers for communicating with internal CPU (see LOCAL_SCRATCH in internal I/O map).

      0-7    General Purpose Value

1:00468h - FIFO_TIMEOUT (R/W)
Timeout (SDIO Wait duration) for cases when reading from empty MBOXes or writing to full MBOXes. On AR6001, timeout is counted in 1ms units (when CORE_CLK=40MHz) or 0.5ms units (when CORE_CLK=80MHz). Timings for AR6002 are probably same/similar?

      0-7    Timeout (01h..FFh) (00h=Reserved/don't use)

1:00469h - FIFO_TIMEOUT_ENABLE (R/W)

      0      Enable FIFO Timeouts (0=Disable, 1=Enable)
      1-7    -

1:0046Ah - DISABLE_SLEEP (R/W)

      0      Prevent Sleep                       (0=Allow Sleep, 1=Prevent Sleep)
      1      Prevent Sleep when Host IRQ pending (0=Allow Sleep, 1=Prevent Sleep)
      2-7    -

1:0046Eh - LOCAL_BUS_ENDIAN (R/W) (AR6001 only, not hw2/hw4/hw6)

      0      AR6001 only: (0=Little Endian, 1=Big Endian)   ;-not hw2/hw4/hw6
      1-7    -

1:00470h - LOCAL_BUS (R and R/W)

      0-1    Current Chip State (0=Shutdown, 1=On, 2=Sleep, 3=Wakeup) (R)
      2      AR6001 only: KEEP_AWAKE (R/W)                  ;\
      3      AR6001 only: IO_ENABLE  (R/W)                  ; not hw2/hw4/hw6
      4      AR6001 only: SOFT_RESET (R/W)                  ;/
      5-7    -

1:00472h - INT_WLAN (R/W)

      0-7    "VECTOR" or interrupt 0..7 ?  (0=No change, 1=Set)

Sends IRQs to internal CPU (see WLAN_MBOX_INT_STATUS bit0-7).
1:00474h..00477h - WINDOW_DATA

      0-31   DATA

Used to access the internal Xtensa memory space. The actual memory access occurs when writing the WINDOW_xxx_ADDR registers (see below).
1:00478h..0047Bh - WINDOW_WRITE_ADDR (W) (read: crashes hardware?)
1:0047Ch..0047Fh - WINDOW_READ_ADDR (W) (read: crashes hardware?)

      0-1    Ignored
      2-27   ADDR (in 4-byte steps)
      28-31  ?

Writing an address to these registers causes 32bit data to be transferred to/from WINDOW_DATA register.

      For a memory write: First write WINDOW_DATA, then write WINDOW_WRITE_ADDR
      For a memory read: First write WINDOW_READ_ADDR, then read WINDOW_DATA

The memory transfers seem to occur on writing address LSB (ie. one must first write the upper three ADDR bytes, then write the lower ADDR byte; that requires sending two separate SDIO commands, except, for accesses within the same 100h-byte block, one may get away with a single SDIO command for changing the LSB only, and leaving the MSBs unchanged).
Caution: Trying to read the ADDR registers seems to be somehow crashing the SDIO hardware (causing errors when trying to send any further SDIO commands).
1:00480h - HOST_CTRL_SPI_CONFIG (R/W)
This register can be accessed only via SPI interface.

      0-1    DATA_SIZE (0=8bit, 1=16bit, 2=32bit, 3=Reserved) (addr = always 16bit)
      2      TEST_MODE (0=Normal, 1=Loopback/Echo)
      3      INTERRUPT_ENABLE (0=Disable, 1=Enable)
      4      SPI_RESET (0=Normal Operation, 1=Reset SPI core)
      5      AR6001 only, not AR6002? - SPI_CLK_OFFSET (R)
      6      -
      7      AR6001 only, not AR6002? - ENDIAN (R/W)

1:00481h - HOST_CTRL_SPI_STATUS (R/W)
This register is automatically output on SPI bus after completion of SPI data transfers.

      0      READY    (0=Command Pending, 1=Completed/Ready)                (R)
      1      WR_ERR   (0=Okay, 1=Write-Error)  (write: 0=No change, 1=Ack)  (R/ack)
      2      RD_ERR   (0=Okay, 1=Read-Error)   (write: 0=No change, 1=Ack)  (R/ack)
      3      ADDR_ERR (0=Okay, 1=Addr-Error)   (write: 0=No change?, 1=Ack?)
      4      AR6001 only, not AR6002? - IFF_ERR
      5      AR6001 only, not AR6002? - DMA_OVER
      6-7    -

1:00482h - NON_ASSOC_SLEEP_EN ;hw2/hw4/hw6 (but didn't exist on AR6001)

      0      BIT
      1-7    -

1:00483h - CPU_DBG_SEL - hw4/hw6 only

      0-5    BIT                                            ;-hw4/hw6 only
      6-7    -

1:00484h..00487h - CPU_DBG[0..3] - hw4/hw6 only

      0-7    DATA                                           ;-hw4/hw6 only

1:00490h..00497h - GMBOX_RX_LOOKAHEAD[0..7] - hw4/hw6 only

      0-7    DATA                                           ;-hw4/hw6 only

1:00498h - GMBOX_RX_LOOKAHEAD_MUX - hw4/hw6 only

      0      SEL                                            ;-hw4/hw6 only
      1-7    -

1:00600h..007FFh - CIS_WINDOW[0..511] (R/W?!)

      0-7    DATA

DSi Atheros Wifi Misc

Atheros chip References
Related Atheros chips:

      AR6001  with MIPS CPU, 18x18 pin BGA package    ;not used in DSi/3DS
      AR6002  with Xtensa CPU, 13x13 pin BGA package  ;used in early DSi
      AR6013  unknown details (built-in MM3218?)      ;used in later DSi
      AR6014  unknown details (similar to AR6013?)    ;used in 3DS

There are some datasheets & source code:

      http://www.datasheetspdf.com/PDF/AR6002/705769/6  ;AR6002 datasheet 56 pages
      http://www.datasheetspdf.com/PDF/AR6001X/900300/1 ;AR6001 datasheet 148 pages
      http://svn.openmoko.org/developers/nbd/ar6k/      ;AR6K source code

The overall hardware registers appear to be same for all AR60xx chips (no matter if they contain MIPS or Xtensa CPUs). The AR6002 datasheet doesn't contain ANY details about hardware registers. The AR6001 datasheet describes SOME hardware registers. And, the AR6K source code contains details about MORE undocumented hardware registers (in some cases listing DIFFERENT addresses as in the datasheet).
The AR6013/AR6014 chips are probably custom designs with some extra MM3218 emulation for NDS games (and possible with some unknown extra hardware features).
BPTWL
Apart from SDIO bus, some wifi functions are also controlled by the BPTWL chip (accessed via I2C bus). The wifi related BPTWL signals are:

      ATH_TX_H              ;\maybe some/all of these do just indicate traffic
      WL_RXPE               ; (for blinking the wifi LED, if it is enabled)
      WL_TXPE               ;/
      /WIFI_RST             ;-Reset or so

That signals seem to be used with BPTWL register 30h, which is allowing to disable the Wifi LED, and might also allow to do things like restting the Wifi hardware, and/or switching between NDS and DSi wifi-modes.

DSi Atheros Wifi - Command Summary

BMI Command Summary (Bootloader Messaging Interface)

      00h   BMI_NO_COMMAND                             Invalid (ignored)
      01h   BMI_DONE                                   Launch Firmware
      02h   BMI_READ_MEMORY                            Read Memory
      03h   BMI_WRITE_MEMORY (normal)                  Write Memory
      03h   BMI_WRITE_MEMORY (with dest=00001234h)     Segmented Write (not in DSi)
      04h   BMI_EXECUTE                                Execute
      05h   BMI_SET_APP_START                          Set App Start
      06h   BMI_READ_SOC_REGISTER                      Read Register
      07h   BMI_WRITE_SOC_REGISTER                     Write Register
      08h   BMI_GET_TARGET_ID aka BMI_GET_TARGET_INFO  Get Version
      09h   BMI_ROMPATCH_INSTALL                       TCAM/BCAM_xxxxx
      0Ah   BMI_ROMPATCH_UNINSTALL                     TCAM/BCAM_Clr_index_and_xxx
      0Bh   BMI_ROMPATCH_ACTIVATE                      TCAM/BCAM_Set_indices   ;\
      0Ch   BMI_ROMPATCH_DEACTIVATE                    TCAM/BCAM_Clr_indices   ;/
      0Dh   BMI_LZ_STREAM_START                        LZ Uncompress Stream Start
      0Eh   BMI_LZ_DATA                                LZ Data Input
      0Fh   BMI_NVRAM_PROCESS ;not implemented in DSi  Invalid (ignored)
      10h..FFFFFFFFh  Unused                           Invalid (ignored)

HTC Services/Handshake
After BMI, and before WMI, there is a "HTC_SERVICES" handshake with following values:

      RSVD_SERVICE_GROUP     = 0
      WMI_SERVICE_GROUP      = 1
      HTC_TEST_GROUP         = 254
      HTC_SERVICE_GROUP_LAST = 255

MAKE_SERVICE_ID(group,index) = group*100h + index
NOTE: service ID of 0000h is reserved and should never be used

      HTC_CTRL_RSVD_SVC = MAKE_SERVICE_ID(RSVD_SERVICE_GROUP,1)
      WMI_CONTROL_SVC   = MAKE_SERVICE_ID(WMI_SERVICE_GROUP,0)  ;control
      WMI_DATA_BE_SVC   = MAKE_SERVICE_ID(WMI_SERVICE_GROUP,1)  ;best effort
      WMI_DATA_BK_SVC   = MAKE_SERVICE_ID(WMI_SERVICE_GROUP,2)  ;background
      WMI_DATA_VI_SVC   = MAKE_SERVICE_ID(WMI_SERVICE_GROUP,3)  ;video
      WMI_DATA_VO_SVC   = MAKE_SERVICE_ID(WMI_SERVICE_GROUP,4)  ;voice
      WMI_MAX_SERVICES  = 5

raw stream service (i.e. flash, tcmd, calibration apps):

      HTC_RAW_STREAMS_SVC = MAKE_SERVICE_ID(HTC_TEST_GROUP,0)

WMI Command Summary (Wireless Module Interface)

      0001h  WMI_CONNECT_CMD
      0002h  WMI_RECONNECT_CMD
      0003h  WMI_DISCONNECT_CMD
      0004h  WMI_SYNCHRONIZE_CMD
      0005h  WMI_CREATE_PSTREAM_CMD      ;aka WMI_CRE_PRIORITY_STREAM
      0006h  WMI_DELETE_PSTREAM_CMD      ;aka WMI_DEL_PRIORITY_STREAM
      0007h  WMI_START_SCAN_CMD
      0008h  WMI_SET_SCAN_PARAMS_CMD
      0009h  WMI_SET_BSS_FILTER_CMD      ;aka WMI_BSS_FILTER_CMD
      000Ah  WMI_SET_PROBED_SSID_CMD
      000Bh  WMI_SET_LISTEN_INT_CMD
      000Ch  WMI_SET_BMISS_TIME_CMD
      000Dh  WMI_SET_DISC_TIMEOUT_CMD    ;aka WMI_SET_DISCONNECT_TIMEOUT
      000Eh  WMI_GET_CHANNEL_LIST_CMD    ;reply 000Eh  ;aka WMI_CHANNEL_LIST
      000Fh  WMI_SET_BEACON_INT_CMD
      0010h  WMI_GET_STATISTICS_CMD      ;reply WMI_REPORT_STATISTICS
      0011h  WMI_SET_CHANNEL_PARAMS_CMD  ;aka WMI_CHANNEL_PARAMS_CMD
      0012h  WMI_SET_POWER_MODE_CMD      ;aka WMI_POWER_MODE_CMD
      0013h  WMI_SET_IBSS_PM_CAPS_CMD    ;aka WMI_IBSS_PM_CAPS_CMD
      0014h  WMI_SET_POWER_PARAMS_CMD    ;aka WMI_POWER_PARAMS_CMD
      0015h  WMI_SET_POWERSAVE_TIMERS_POLICY_CMD  ;aka WMI_POWERSAVE...
      0016h  WMI_ADD_CIPHER_KEY_CMD
      0017h  WMI_DELETE_CIPHER_KEY_CMD   ;\
      0018h  WMI_ADD_KRK_CMD             ; ignored dummy commands on DSi
      0019h  WMI_DELETE_KRK_CMD          ;/
      001Ah  WMI_SET_PMKID_CMD
      001Bh  WMI_SET_TX_PWR_CMD
      001Ch  WMI_GET_TX_PWR_CMD          ;aka WMI_TX_PWR ;reply 001Ch
      001Dh  WMI_SET_ASSOC_INFO_CMD
      001Eh  WMI_ADD_BAD_AP_CMD
      001Fh  WMI_DELETE_BAD_AP_CMD
      0020h  WMI_SET_TKIP_COUNTERMEASURES_CMD
      0021h  WMI_RSSI_THRESHOLD_PARAMS_CMD
      0022h  WMI_TARGET_ERROR_REPORT_BITMASK_CMD
      0023h  WMI_SET_ACCESS_PARAMS_CMD
      0024h  WMI_SET_RETRY_LIMITS_CMD
      0025h  WMI_SET_OPT_MODE_CMD
      0026h  WMI_OPT_TX_FRAME_CMD
      0027h  WMI_SET_VOICE_PKT_SIZE_CMD
      0028h  WMI_SET_MAX_SP_LEN_CMD
      0029h  WMI_SET_ROAM_CTRL_CMD
      002Ah  WMI_GET_ROAM_TBL_CMD ;aka REPORT_ROAM_TBL,TARGET_ROAM_TBL ;reply 100Fh
      002Bh  WMI_GET_ROAM_DATA_CMD       ;reply 1015h ?    ;\
      002Ch  WMI_ENABLE_RM_CMD                             ; not implemented in DSi
      002Dh  WMI_SET_MAX_OFFHOME_DURATION_CMD              ;/
      002Eh  WMI_EXTENSION_CMD   ;prefix for WMIX "Non-wireless extensions"...
      002Eh:2001h  WMIX_DSETOPEN_REPLY_CMD ;reply to 3001h ;\not implemented in DSi
      002Eh:2002h  WMIX_DSETDATA_REPLY_CMD ;reply to 3003h ;/
      002Eh:2003h  WMIX_GPIO_OUTPUT_SET_CMD   ;reply=3006h          ;\
      002Eh:2004h  WMIX_GPIO_INPUT_GET_CMD    ;reply=3005h          ;
      002Eh:2005h  WMIX_GPIO_REGISTER_SET_CMD ;reply=3006h, too     ; GPIO
      002Eh:2006h  WMIX_GPIO_REGISTER_GET_CMD ;reply=3005h, too     ;
      002Eh:2007h  WMIX_GPIO_INTR_ACK_CMD ;reply to 3004h           ;/
      002Eh:2008h  WMIX_HB_CHALLENGE_RESP_CMD ;reply=3007h          ;-HB=heartbeat
      002Eh:2009h  WMIX_DBGLOG_CFG_MODULE_CMD
      002Eh:200Ah  WMIX_PROF_CFG_CMD                       ;\
      002Eh:200Bh  WMIX_PROF_ADDR_SET_CMD                  ;
      002Eh:200Ch  WMIX_PROF_START_CMD                     ; not implemented in DSi
      002Eh:200Dh  WMIX_PROF_STOP_CMD                      ;
      002Eh:200Eh  WMIX_PROF_COUNT_GET_CMD ;reply 3009h    ;/
      002Fh  WMI_SNR_THRESHOLD_PARAMS_CMD
      0030h  WMI_LQ_THRESHOLD_PARAMS_CMD
      0031h  WMI_SET_LPREAMBLE_CMD
      0032h  WMI_SET_RTS_CMD
      0033h  WMI_CLR_RSSI_SNR_CMD
      0034h  WMI_SET_FIXRATES_CMD   ;aka WMI_FIX_RATES_CMD
      0035h  WMI_GET_FIXRATES_CMD        ;reply 0035h
      0036h  WMI_SET_AUTH_MODE_CMD  ;aka WMI_SET_RECONNECT_AUTH_MODE_CMD

;below not in AR6001

      0037h  WMI_SET_REASSOC_MODE_CMD
      0038h  WMI_SET_WMM_CMD
      0039h  WMI_SET_WMM_TXOP_CMD
     ;NOT!   WMI_SET_QOS_SUPP_CMD     ;<-- this NOT here!
      003Ah  WMI_TEST_CMD                                  ;-not implemented in DSi
      003Bh  WMI_SET_BT_STATUS_CMD    ;\AR6002 Bluetooth Coexistence only?
      003Ch  WMI_SET_BT_PARAMS_CMD    ;/
      003Dh  WMI_SET_KEEPALIVE_CMD
      003Eh  WMI_GET_KEEPALIVE_CMD       ;reply 003Eh
      003Fh  WMI_SET_APPIE_CMD  ;aka SET_APP_IE
      0040h  WMI_GET_APPIE_CMD  ;aka GET_APP_IE ;reply=?   ;-not implemented in DSi
      0041h  WMI_SET_WSC_STATUS_CMD   ;aka WSC_REG
      0042h  WMI_SET_HOST_SLEEP_MODE_CMD                   ;\
      0043h  WMI_SET_WOW_MODE_CMD                          ;
      0044h  WMI_GET_WOW_LIST_CMD        ;reply=1018h      ; Wake on Wireless (WOW)
      0045h  WMI_ADD_WOW_PATTERN_CMD                       ;
      0046h  WMI_DEL_WOW_PATTERN_CMD                       ;/
     ;below four as of "AR6kSDK.build_sw.18/include/wmi.h" (from 2006)
     ;0047h  WMI_SET_MAC_ADDRESS_CMD (later moved to F003h)
     ;0048h  WMI_SET_AKMP_PARAMS_CMD (later moved to F004h)
     ;0049h  WMI_SET_PMKID_LIST_CMD  (later moved to F005h)
     ;004Ah  WMI_GET_PMKID_LIST_CMD  (later moved to F006h)
     ;below two are almost always supported (but DSi is somewhat different)
     ;0047h  WMI_SET_FRAMERATES_CMD    ;aka WMI_FRAME_RATES_CMD  ;-cmd 48h on DSi!
     ;0048h  WMI_SET_AP_PS_CMD         ;aka WMI_AP_PS_CMD        ;-not on DSi

Special DSi commands:

      0047h  WMI_START_WHATEVER_TIMER_CMD                        ;-whatever on DSi!
      0048h  WMI_SET_FRAMERATES_CMD    ;aka WMI_FRAME_RATES_CMD  ;-cmd 48h on DSi!
      0049h  WMI_HOST_EXIT_NOTIFY_CMD  ;special DSi/3DS command

Special 3DS commands (for Type4 firmware):

      004Ah  WMI_AP_HIDDEN_SSID_CMD                         ;01h bytes (1)
      004Bh  WMI_AP_SET_NUM_STA_CMD aka WMI_AP_NUM_STA_CMD  ;01h bytes (1)
      004Ch  WMI_AP_ACL_POLICY_CMD                          ;01h bytes (1)
      004Dh  WMI_AP_ACL_MAC_LIST_CMD aka WMI_AP_ACL_MAC_CMD ;09h bytes (1+1+6+1)
      004Eh  WMI_AP_CONFIG_COMMIT_CMD                       ;34h bytes (..)
      004Fh  WMI_AP_SET_MLME_CMD                            ;09h bytes (6+2+1)
      0050h  WMI_AP_SET_PVB_CMD     ;ignored on 3DS         ;06h bytes (ignored)
      0051h  WMI_AP_CONN_INACT_CMD                          ;04h bytes (4)
      0052h  WMI_AP_PROT_SCAN_TIME_CMD                      ;08h bytes (4+4)
      0053h  WMI_?                                      ;01h bytes (1)
      0054h  N/A
      0055h  WMI_?                                      ;04h bytes (2+2)
      0056h  WMI_ignored_?                              ;01h bytes (ignored)
      0057h  WMI_?  ;with EVENT_1022h                   ;00h bytes
      0058h  WMI_?     <-- with optional params?        ;var       (2+2+1+1+N)
      0059h  WMI_?       ;only lower 8bit used          ;04h bytes (4; only 1 used)
      005Ah  WMI_?                                      ;01h bytes (1)
      005Bh  WMI_?                                      ;04h bytes (2+1+1)
      005Ch  WMI_?                                      ;04h bytes (1+3)
      005Dh  WMI_?                                      ;0Ah bytes (1+1+2+1+1+2+2)
      005Eh  WMI_?                                      ;01h bytes (1)
      005Fh  WMI_?                                      ;04h bytes (4)

Special 3DS commands (for Type5 firmware):

      0060h  WMI_?                             ;3Ah bytes
      0061h  WMI_?                             ;28h bytes
      0062h  WMI_?                             ;12h bytes
      0063h  WMI_?                             ;02h bytes
      0064h  WMI_?                             ;03h bytes
      0065h  WMI_?                             ;07h bytes
      0066h  WMI_?                             ;07h bytes
      0067h  WMI_?                             ;03h bytes
      0068h  WMI_?  ;can be with EVENT_1023h   ;01h bytes
      0069h  WMI_?                             ;00h bytes
      006Ah  WMI_?                             ;00h bytes
      006Bh  WMI_?                             ;01h bytes
      006Ch  WMI_?                             ;06h bytes
      006Dh  WMI_?  ;with EVENT_1026h          ;00h bytes
      006Eh  WMI_?                             ;01h bytes
      006Fh  WMI_?                             ;06h bytes
      0070h  WMI_?                             ;01h bytes
      0071h  WMI_?                             ;08h bytes
      0072h  WMI_?                             ;02h bytes
      0073h  WMI_?  ;with EVENT_1027h          ;01h bytes

Newer commands

      0049h  WMI_SET_QOS_SUPP_CMD  ;<-- this shall be HERE ;\
      004Ah  WMI_SET_IE_CMD  ;new cmd from 2012            ; not implemented in DSi
      08xxh  WILOCITY types         ;\wil6210 stuff        ;
      09xxh  Performance monitoring ;/                     ;/
      8000h  WMI_THIN_RESERVED_START                       ;\
      8000h  WMI_THIN_CONFIG_CMD                           ;
      8001h  WMI_THIN_SET_MIB_CMD                          ; not implemented in DSi
      8002h  WMI_THIN_GET_MIB_CMD ;reply=8001h             ; (thin commands
      8003h  WMI_THIN_JOIN_CMD      ;\newer                ; from wmi_thin.h)
      8004h  WMI_THIN_CONNECT_CMD   ; versions             ;
      8005h  WMI_THIN_RESET_CMD     ;/only                 ;
      8FFFh  WMI_THIN_RESERVED_END                         ;/

Developer commands

      F000h  WMI_SET_BITRATE_CMD    ;aka WMI_BIT_RATE_CMD
      F001h  WMI_GET_BITRATE_CMD                         ;reply=F001h
      F002h  WMI_SET_WHALPARAM_CMD  ;aka WHAL_PARAMCMD
      F003h  WMI_SET_MAC_ADDRESS_CMD   ;formerly 0047h     ;-not implemented in DSi
      F004h  WMI_SET_AKMP_PARAMS_CMD   ;formerly 0048h
      F005h  WMI_SET_PMKID_LIST_CMD    ;formerly 0049h
      F006h  WMI_GET_PMKID_LIST_CMD    ;formerly 004Ah   ;reply 1019h

Below stuff (F007h..F05Eh) is not implemented in DSi...

      F007h  WMI_ABORT_SCAN_CMD
      F008h  WMI_SET_TARGET_EVENT_REPORT_CMD
      F009h  WMI_UNUSED1 or WMI_PYXIS_CONFIG_CMD    ;\Unused (or Pyxis specific
      F00Ah  WMI_UNUSED2 or WMI_PYXIS_OPERATION_CMD ;/commands)
      F00Bh  WMI_AP_HIDDEN_SSID_CMD                          ;\
      F00Ch  WMI_AP_SET_NUM_STA_CMD aka WMI_AP_NUM_STA_CMD   ; AP mode commands
      F00Dh  WMI_AP_ACL_POLICY_CMD                           ;
      F00Eh  WMI_AP_ACL_MAC_LIST_CMD aka WMI_AP_ACL_MAC_CMD  ; (not on DSi, but
      F00Fh  WMI_AP_CONFIG_COMMIT_CMD                        ; 3DS type4 supports
      F010h  WMI_AP_SET_MLME_CMD                             ; F00Ah..F013h,
      F011h  WMI_AP_SET_PVB_CMD                              ; renumbered to
      F012h  WMI_AP_CONN_INACT_CMD                           ; 004Ah..0052h)
      F013h  WMI_AP_PROT_SCAN_TIME_CMD                       ;
      F014h  WMI_AP_SET_COUNTRY_CMD ;aka WMI_SET_COUNTRY_CMD ;
      F015h  WMI_AP_SET_DTIM_CMD                             ;
      F016h  WMI_AP_MODE_STAT_CMD      ;formerly N/A         ;/
      F017h  WMI_SET_IP_CMD            ;formerly F016h                      ;\
      F018h  WMI_SET_PARAMS_CMD        ;formerly F017h   ;reply=101Fh       ;
      F019h  WMI_SET_MCAST_FILTER_CMD  ;formerly F018h                      ;
      F01Ah  WMI_DEL_MCAST_FILTER_CMD  ;formerly F019h                      ;/
      F01Bh  WMI_ALLOW_AGGR_CMD                                             ;\
      F01Ch  WMI_ADDBA_REQ_CMD                                              ;
      F01Dh  WMI_DELBA_REQ_CMD                                              ;
      F01Eh  WMI_SET_HT_CAP_CMD                                             ;
      F01Fh  WMI_SET_HT_OP_CMD                                              ;
      F020h  WMI_SET_TX_SELECT_RATES_CMD                                    ;
      F021h  WMI_SET_TX_SGI_PARAM_CMD                                       ;
      F022h  WMI_SET_RATE_POLICY_CMD                                        ;/
      F023h  WMI_HCI_CMD_CMD aka WMI_HCI_CMD                                ;\
      F024h  WMI_RX_FRAME_FORMAT_CMD                                        ;
      F025h  WMI_SET_THIN_MODE_CMD                                          ;
      F026h  WMI_SET_BT_WLAN_CONN_PRECEDENCE_CMD                            ;/
      F027h  WMI_AP_SET_11BG_RATESET_CMD                                    ;\
      F028h  WMI_SET_PMK_CMD                                                ;
      F029h  WMI_MCAST_FILTER_CMD                                           ;/
      F02Ah  WMI_SET_BTCOEX_FE_ANT_CMD                      ;\
      F02Bh  WMI_SET_BTCOEX_COLOCATED_BT_DEV_CMD            ;
      F02Ch  WMI_SET_BTCOEX_SCO_CONFIG_CMD                  ; AR6003
      F02Dh  WMI_SET_BTCOEX_A2DP_CONFIG_CMD                 ; Bluetooth Coexistence
      F02Eh  WMI_SET_BTCOEX_ACLCOEX_CONFIG_CMD              ;
      F02Fh  WMI_SET_BTCOEX_BTINQUIRY_PAGE_CONFIG_CMD       ;
      F030h  WMI_SET_BTCOEX_DEBUG_CMD                       ;
      F031h  WMI_SET_BTCOEX_BT_OPERATING_STATUS_CMD         ;
      F032h  WMI_GET_BTCOEX_STATS_CMD  ;reply=1026h..1028h  ;
      F033h  WMI_GET_BTCOEX_CONFIG_CMD ;reply=1027h..1029h  ;/
      F034h  WMI_SET_DFS_ENABLE_CMD        ;aka WMI_SET_DFS_CMD maybe ?   ;\
      F035h  WMI_SET_DFS_MINRSSITHRESH_CMD ;aka WMI_SET_DFS_CMD too ??    ; DFS
      F036h  WMI_SET_DFS_MAXPULSEDUR_CMD   ;aka WMI_SET_DFS_CMD too ??    ;
      F037h  WMI_DFS_RADAR_DETECTED_CMD    ;aka WMI_RADAR_DETECTED_CMD    ;/
      F038h  WMI_P2P_SET_CONFIG_CMD                 ;\  ;<-- confirmed to be F038h
      F039h  WMI_WPS_SET_CONFIG_CMD   ;P2P related  ;
      F03Ah  WMI_SET_REQ_DEV_ATTR_CMD ;P2P related  ; P2P CMDS
      F03Bh  WMI_P2P_FIND_CMD                       ;
      F03Ch  WMI_P2P_STOP_FIND_CMD                  ;
      F03Dh  WMI_P2P_GO_NEG_START_CMD               ;
      F03Eh  WMI_P2P_LISTEN_CMD                     ;/
      F03Fh  WMI_CONFIG_TX_MAC_RULES_CMD            ;\  ;<-- claimed to be F040h ?
      F040h  WMI_SET_PROMISCUOUS_MODE_CMD           ;
      F041h  WMI_RX_FRAME_FILTER_CMD                ;
      F042h  WMI_SET_CHANNEL_CMD                    ;/
      F043h  WMI_WAC_ENABLE_CMD aka WMI_ENABLE_WAC_CMD      ;\
      F044h  WMI_WAC_SCAN_REPLY_CMD                         ; WAC commands
      F045h  WMI_WAC_CTRL_REQ_CMD                           ;/
      F046h  WMI_SET_DIV_PARAMS_CMD aka WMI_DIV_PARAMS_CMD
      F047h  WMI_GET_PMK_CMD         ;reply?                ;\
      F048h  WMI_SET_PASSPHRASE_CMD                         ;/
      F049h  WMI_SEND_ASSOC_RES_CMD      ;aka WMI_SEND_ASSOCRES_CMD     ;\ASSOC
      F04Ah  WMI_SET_ASSOC_REQ_RELAY_CMD ;aka WMI_SET_ASSOCREQ_RELAY    ;/

Below uses entirely different numbering in code from 2010 vs 2012...

      F04Bh or F04Dh WMI_ACS_CTRL_CMD ;aka WMI_ACS_CTRL_MSG  ;-ACS sub-commands
      F04Ch or F052h WMI_SET_EXCESS_TX_RETRY_THRES_CMD
      F04Dh or N/A   WMI_SET_TBD_TIME_CMD   ;-added for wmiconfig command for TBD
      F04Eh or N/A   WMI_PKTLOG_ENABLE_CMD                ;\Pktlog cmds
      F04Fh or N/A   WMI_PKTLOG_DISABLE_CMD               ;/(code from 2012 only)
      F050h or F053h WMI_P2P_GO_NEG_REQ_RSP_CMD           ;\
      F051h or F054h WMI_P2P_GRP_INIT_CMD                 ;
      F052h or F055h WMI_P2P_GRP_FORMATION_DONE_CMD       ;
      F053h or F056h WMI_P2P_INVITE_CMD                   ; More P2P commands
      F054h or F057h WMI_P2P_INVITE_REQ_RSP_CMD           ;
      F055h or F058h WMI_P2P_PROV_DISC_REQ_CMD            ;
      F056h or F059h WMI_P2P_SET_CMD                      ;/
      F057h or F04Bh WMI_GET_RFKILL_MODE_CMD                          ;\RFKILL
      F058h or F04Ch WMI_SET_RFKILL_MODE_CMD ;aka WMI_RFKILL_MODE_CMD ;/
      F059h or F05Ah WMI_AP_SET_APSD_CMD                  ;\More AP commands
      F05Ah or F05Bh WMI_AP_APSD_BUFFERED_TRAFFIC_CMD     ;/
      F05Bh or F05Ch WMI_P2P_SDPD_TX_CMD                  ;\
      F05Ch or F05Dh WMI_P2P_STOP_SDPD_CMD                ; More P2P commands
      F05Dh or F05Eh WMI_P2P_CANCEL_CMD                   ;/
      F05Eh or F04Eh WMI_STORERECALL_CONFIGURE_CMD        ;\Ultra low power
      F05Fh or F04Fh WMI_STORERECALL_RECALL_CMD           ; store/recall commands
      F060h or F050h WMI_STORERECALL_HOST_READY_CMD       ;/
      F061h or F051h WMI_FORCE_TARGET_ASSERT_CMD          ;-
      F062h or N/A   WMI_SET_PROBED_SSID_EX_CMD           ;\
      F063h or N/A   WMI_SET_NETWORK_LIST_OFFLOAD_CMD     ;
      F064h or N/A   WMI_SET_ARP_NS_OFFLOAD_CMD           ;
      F065h or N/A   WMI_ADD_WOW_EXT_PATTERN_CMD          ; NEW stuff
      F066h or N/A   WMI_GTK_OFFLOAD_OP_CMD               ; (code from 2012 only)
      F067h or N/A   WMI_REMAIN_ON_CHNL_CMD               ;
      F068h or N/A   WMI_CANCEL_REMAIN_ON_CHNL_CMD        ;
      F069h or N/A   WMI_SEND_ACTION_CMD                  ;
      F06Ah or N/A   WMI_PROBE_REQ_REPORT_CMD             ;
      F06Bh or N/A   WMI_DISABLE_11B_RATES_CMD            ;
      F06Ch or N/A   WMI_SEND_PROBE_RESPONSE_CMD          ;
      F06Dh or N/A   WMI_GET_P2P_INFO_CMD                 ;
      F06Eh or N/A   WMI_AP_JOIN_BSS_CMD                  ;/
      ?              WMI_SET_ADHOC_BSSID_CMD              ;-old, not implemented?
      F0AFh          WMI_AP_PSBUFF_OFFLOAD  ;-QCA4002 chipset on GT202 WiFi module

DSi Atheros Wifi - Response Summary

Unknown yet HOW events are transferred; the DSi does send some events via MBOX0, apparently with whatever header(s), which MIGHT be defined in "htc.h". The events spotted on DSi are formatted as so:

      00h 2        Values 01h,02h      ;or 00h,02h in case of "obscure values"
      02h 2        Length (excluding trailing zerofilled area)
      04h 2        Values 08h,00h      ;or 0Ch,00h
      06h 2        Event ID (100xh)    ;or "obscure values" (0001h, 0003h, 0201h)
      08h LEN-0Ah  Event/Response Data (Length-0Ah bytes)
      ..  2        Values 02h,06h
      ..  80h-LEN  Zerofilled (till 80h-byte size)  ;sometimes contains a D0h-byte?

Some 'events' may occur due to actual hardware events. Other 'events' may occur as response to certain commands - other commands are THEORETICALLY not having any responses, though MAYBE they do still send some sort of confirmation/error values, which MIGHT explain the above "obscure values".
WMI Events/Responses
Events/Responses with same ID as corresponding command

      000Eh  WMI_GET_CHANNEL_LIST_CMD
      001Ch  WMI_GET_TX_PWR_CMD
      0035h  WMI_GET_FIXRATES_CMD
      003Eh  WMI_GET_KEEPALIVE_CMD
      F001h  WMI_GET_BITRATE_CMD

Events/Responses that could/should exist (but aren't documented)

      ?      WMI_GET_APPIE_CMD  ;aka GET_APP_IE            ;\not implemented in DSi
      ?      WMI_AP_MODE_STAT_CMD  ;has reply?             ;/

Events/Responses that have REPLY structs defined (but CMDs don't send reply?)

      ?      WMI_CRE_PRIORITY_STREAM_REPLY                 ;\
      ?      WMI_DEL_PRIORITY_STREAM_REPLY                 ; not implemented in DSi
      ?      WMI_FRAME_RATES_REPLY                         ;/

Events/Responses with special IDs

      1001h  WMI_READY_EVENT
      1002h  WMI_CONNECT_EVENT
      1003h  WMI_DISCONNECT_EVENT
      1004h  WMI_BSSINFO_EVENT   ;aka WMI_BSS_INFO
      1005h  WMI_CMDERROR_EVENT  ;aka WMI_CMD_ERROR_EVENT  ;for CMD 01h,11h,16h,26h
      1006h  WMI_REGDOMAIN_EVENT ;aka WMI_REG_DOMAIN_EVENT
      1007h  WMI_PSTREAM_TIMEOUT_EVENT
      1008h  WMI_NEIGHBOR_REPORT_EVENT
      1009h  WMI_TKIP_MICERR_EVENT
      100Ah  WMI_SCAN_COMPLETE_EVENT
      100Bh  WMI_REPORT_STATISTICS_EVENT    ;related to CMD 0010h ?
      100Ch  WMI_RSSI_THRESHOLD_EVENT
      100Dh  WMI_ERROR_REPORT_EVENT ;aka WMI_TARGET_ERROR_REPORT_EVENT
      100Eh  WMI_OPT_RX_FRAME_EVENT ;aka WMI_OPT_RX_INFO
      100Fh  WMI_REPORT_ROAM_TBL_EVENT           ;related to CMD 002Ah ?
      1010h  WMI_EXTENSION_EVENT   ;prefix for WMIX events...
      1010h:3001h  WMIX_DSETOPENREQ_EVENT ;request 2001h   ;\
      1010h:3002h  WMIX_DSETCLOSE_EVENT   ;request close   ; not implemented in DSi
      1010h:3003h  WMIX_DSETDATAREQ_EVENT ;request 2002h   ;/
      1010h:3004h  WMIX_GPIO_INTR_EVENT         ;used (interrupt)
      1010h:3005h  WMIX_GPIO_DATA_EVENT         ;used (reply to 2004h and 2006h)
      1010h:3006h  WMIX_GPIO_ACK_EVENT          ;used (reply to 2003h and 2005h)
      1010h:3007h  WMIX_HB_CHALLENGE_RESP_EVENT ;used (reply to 2008h)
      1010h:3008h  WMIX_DBGLOG_EVENT            ;used (probably related to 2009h)
      1010h:3009h  WMIX_PROF_COUNT_EVENT                   ;-not implemented in DSi
      1011h  WMI_CAC_EVENT
      1012h  WMI_SNR_THRESHOLD_EVENT
      1013h  WMI_LQ_THRESHOLD_EVENT
      1014h  WMI_TX_RETRY_ERR_EVENT
      1015h  WMI_REPORT_ROAM_DATA_EVENT ;related to 002Bh? ;\not implemented in DSi
      1016h  WMI_TEST_EVENT                                ;/
      1017h  WMI_APLIST_EVENT
      1018h  WMI_GET_WOW_LIST_EVENT              ;reply to CMD 0044h
      1019h  WMI_GET_PMKID_LIST_EVENT            ;reply to CMD F006h

Below not in AR6kSDK.build_sw.18, however, "101Ah" is USED on DSi...

      101Ah  WMI_CHANNEL_CHANGE_EVENT            ;<-- used on DSi

Below some are spotted on 3DS (possibly inofficial stuff?)
(type4=3ds/internet?, macfilter=3ds/localmultiplay?)

      101Dh     type4, len=0
      101Fh     type4, len=N*4
      1020h     type4, len=8
      1021h     macfilter, len=10h+?      ;"succes"
      1022h     type4, len=0          ;reply to cmd 0057h ?
      1023h     macfilter, len=4+?    ;reply to cmd 0068h
      1024h     type4, len=0Eh
      1025h     type4, len=1   ;thrown by 3DS type4 variant (works when ignored)
      1026h     macfilter, len=0Ch    ;reply to cmd 006Dh
      1027h     macfilter, len=2+?    ;reply to cmd 0073h

Below (101Bh..9004h) not implemented in DSi...

      101Bh  WMI_PEER_NODE_EVENT
      101Ch  WMI_PSPOLL_EVENT ;aka WMI_PS_POLL_EVENT  ;AP mode related?
      101Dh  WMI_DTIMEXPIRY_EVENT
      101Eh  WMI_WLAN_VERSION_EVENT
      101Fh  WMI_SET_PARAMS_REPLY_EVENT  ;reply to CMD F018h (reply to "SET" cmd!)
      1020h  WMI_ADDBA_REQ_EVENT
      1021h  WMI_ADDBA_RESP_EVENT
      1022h  WMI_DELBA_REQ_EVENT aka WMI_DELBA_EVENT
      1023h  WMI_TX_COMPLETE_EVENT
      1024h  WMI_HCI_EVENT_EVENT aka WMI_HCI_EVENT
      1025h  WMI_ACL_DATA_EVENT
      1026h  WMI_REPORT_SLEEP_STATE_EVENT   ;formerly N/A
      1027h  WMI_WAPI_REKEY_EVENT           ;formerly N/A, or 1026h if WAPI_ENABLE
      1028h  WMI_REPORT_BTCOEX_STATS_EVENT  ;formerly 1026h/1027h  ;reply to F032h
      1029h  WMI_REPORT_BTCOEX_CONFIG_EVENT ;formerly 1027h/1028h  ;reply to F033h
      102Ah  WMI_GET_PMK_EVENT aka WMI_GET_PMK_REPLY
      102Bh  WMI_DFS_HOST_ATTACH_EVENT              ;\
      102Ch  WMI_DFS_HOST_INIT_EVENT                ;
      102Dh  WMI_DFS_RESET_DELAYLINES_EVENT         ;
      102Eh  WMI_DFS_RESET_RADARQ_EVENT             ;
      102Fh  WMI_DFS_RESET_AR_EVENT                 ; DFS Events
      1030h  WMI_DFS_RESET_ARQ_EVENT                ;
      1031h  WMI_DFS_SET_DUR_MULTIPLIER_EVENT       ;
      1032h  WMI_DFS_SET_BANGRADAR_EVENT            ;
      1033h  WMI_DFS_SET_DEBUGLEVEL_EVENT           ;
      1034h  WMI_DFS_PHYERR_EVENT                   ;/
      1035h  WMI_CCX_RM_STATUS_EVENT                ;-CCX Evants  ;uh, EvAntS?
      1036h  WMI_P2P_GO_NEG_RESULT_EVENT            ;-P2P Events  ;uh, EventS?
      1037h  WMI_WAC_SCAN_DONE_EVENT                ;\
      1038h  WMI_WAC_REPORT_BSS_EVENT               ; WAC
      1039h  WMI_WAC_START_WPS_EVENT                ;
      103Ah  WMI_WAC_CTRL_REQ_REPLY_EVENT           ;/
      103Bh  WMI_RFKILL_STATE_CHANGE_EVENT          ;\RFKILL Events
      103Ch  WMI_RFKILL_GET_MODE_CMD_EVENT          ;/
      103Dh  WMI_P2P_GO_NEG_REQ_EVENT               ;\
      103Eh  WMI_P2P_INVITE_REQ_EVENT               ;
      103Fh  WMI_P2P_INVITE_RCVD_RESULT_EVENT       ;
      1040h  WMI_P2P_INVITE_SENT_RESULT_EVENT       ; More P2P Events
      1041h  WMI_P2P_PROV_DISC_RESP_EVENT           ;
      1042h  WMI_P2P_PROV_DISC_REQ_EVENT            ;
      1043h  WMI_P2P_START_SDPD_EVENT               ;
      1044h  WMI_P2P_SDPD_RX_EVENT                  ;/
      1045h  WMI_SET_HOST_SLEEP_MODE_CMD_PROCESSED_EVENT  ;-avoid AR6003 crash
      8000h  WMI_THIN_EVENTID_RESERVED_START        ;\
      8001h  WMI_THIN_GET_MIB_EVENT                 ; THIN events (wmi_thin.h)
      8002h  WMI_THIN_JOIN_EVENT                    ;
      8FFFh  WMI_THIN_EVENTID_RESERVED_END          ;/
      9000h  WMI_SET_CHANNEL_EVENT                            ;\
      9001h  WMI_ASSOC_REQ_EVENT aka WMI_ASSOCREQ_EVENT       ; More events,
      9002h  WMI_ACS_EVENT    ;generic ACS event              ; somehow located
      9003h  WMI_REPORT_WMM_PARAMS_EVENT                      ; after THIN area
      9004h  WMI_STORERECALL_STORE_EVENT                      ;/

code from 2012 has WMI_WAPI_REKEY_EVENT re-removed again, the two RFKILL Events moved around (placed into the P2P event area), and WMI_REPORT_WMM_PARAMS_EVENT moved to 10xxh, a new WMI_WAC_REJECT_WPS_EVENT at 10xxh, and WMI_SET_HOST_SLEEP_MODE_CMD_PROCESSED_EVENT removed, and WMI_STORERECALL_STORE_EVENT moved to 9003h, and adds more NEW stuff at 9004h-900Dh:

      10xxh WMI_REPORT_WMM_PARAMS_EVENT     ;-moved to 10xxh or so
      10xxh WMI_WAC_REJECT_WPS_EVENT        ;-NEW
      9003h WMI_STORERECALL_STORE_EVENT     ;-move to HERE
      9004h WMI_WOW_EXT_WAKE_EVENT          ;\
      9005h WMI_GTK_OFFLOAD_STATUS_EVENT    ;
      9006h WMI_NETWORK_LIST_OFFLOAD_EVENT  ;
      9007h WMI_REMAIN_ON_CHNL_EVENT        ; NEW
      9008h WMI_CANCEL_REMAIN_ON_CHNL_EVENT ;
      9009h WMI_TX_STATUS_EVENT             ;
      900Ah WMI_RX_PROBE_REQ_EVENT          ;
      900Bh WMI_P2P_CAPABILITIES_EVENT      ;
      900Ch WMI_RX_ACTION_EVENT             ;
      900Dh WMI_P2P_INFO_EVENT              ;/

DSi Atheros Wifi - Host Interest Area in RAM

Host Interest Area (aka Target Addresses)
Apart from sending BMI and WMI commands via MBOX0, some communication is also done by directly accessing the 100h-byte "Host Interest" area in RAM, this can be done via WINDOW_DATA register (or via BMI commands).
The format of this memory area (defined in "targaddrs.h") is held to be same on all AR60xx chips, however, its BASE ADDRESS may vary on different chips:

      AR6002_HOST_INTEREST_ADDRESS   = 00500400h  ;older DSi
      AR6013_HOST_INTEREST_ADDRESS   = 00520000h  ;newer DSi
      AR6014_HOST_INTEREST_ADDRESS   = 00520000h  ;3DS and New3DS
      AR6003_HOST_INTEREST_ADDRESS   = 00540600h
      MCKINLEY_HOST_INTEREST_ADDRESS = 00400600h

That base address can be also found in the DSi's "Wifi Firmware" fileheader.
Aside from the 100h bytes in RAM, there's also another host interest byte in the LOCAL_SCRATCH[0] register; the CHIP_ID register could be also considered as interesting to the host.
Host Interest Entries in RAM ("host_interest_s" structure, 64 words)

      00h  hi_app_host_interest ;-Pointer to application-defined area, if any.
                                ; (set by Target application during startup)
      04h  hi_failure_state ;-Pointer to register dump area after Target crash
      08h  hi_dbglog_hdr    ;-Pointer to debug logging header
      0Ch  hi_flash_is_present ;Indicates whether or not flash is present on Target
             ;NB: flash_is_present indicator is here not just because it might be
             ;of interest to the Host; but also because it's set early on by
             ;Target's startup asm code and we need it to have a special RAM
             ;address so that it doesn't get reinitialized with the rest of data.
      10h  hi_option_flag     ;-Various flags (see below)
      14h  hi_serial_enable   ;-Boolean whether to output (additional) TTY messages
      18h  hi_dset_list_head  ;-Start address of DataSet index, if any
      1Ch  hi_app_start       ;-Override BMI_DONE Target application start address
      20h  hi_skip_clock_init          ;\
      24h  hi_core_clock_setting       ;
      28h  hi_cpu_clock_setting        ; Clock and voltage tuning
      2Ch  hi_system_sleep_setting     ;
      30h  hi_xtal_control_setting     ;
      34h  hi_pll_ctrl_setting_24ghz   ;
      38h  hi_pll_ctrl_setting_5ghz    ;
      3Ch  hi_ref_voltage_trim_setting ;
      40h  hi_clock_info               ;/
      44h  hi_bank0_addr_value         ;\Flash configuration overrides, used only
      48h  hi_bank0_read_value         ; when firmware is not executing from flash
      4Ch  hi_bank0_write_value        ; (when using flash, modify the global
      50h  hi_bank0_config_value       ;/variables with equivalent names)
      54h  hi_board_data               ;\Pointer to Board Data (eg. from I2C
      58h  hi_board_data_initialized   ;/EEPROM) and data present/init flag
      5Ch  hi_dset_RAM_index_table     ;-
      60h  hi_desired_baud_rate        ;\ ;<-- for TTY/UART (default=9600 decimal)
      64h  hi_dbglog_config            ;
      68h  hi_end_RAM_reserve_sz       ;
      6Ch  hi_mbox_io_block_sz         ;/
      70h  hi_num_bpatch_streams       ;-Unused (supposedly was used before 2010)
      74h  hi_mbox_isr_yield_limit     ;-
      78h  hi_refclk_hz                ;-OSC  ;NN,000,000 decimal (26MHz/40MHz)
     Below seems to be newer stuff... not implemented in DSi... (?)
      7Ch  hi_ext_clk_detected         ;\
      80h  hi_dbg_uart_txpin           ;
      84h  hi_dbg_uart_rxpin           ;
      88h  hi_hci_uart_baud            ;     <-- used in 3DS WMI_READY_EVENT ?
      8Ch  hi_hci_uart_pin_assignments ;/ ;<-- byte[0]=tx, [1]=rx, [2]=rts, [3]=cts
      90h  hi_hci_uart_baud_scale_val  ;\
      94h  hi_hci_uart_baud_step_val   ;/
      98h  hi_allocram_start           ;\
      9Ch  hi_allocram_sz              ;/
      A0h  hi_hci_bridge_flags         ;\
      A4h  hi_hci_uart_support_pins    ;/
             ;NOTE: byte[0]=RESET pin (bit7 is polarity), byte[1..3]=for future use
      A8h  hi_hci_uart_pwr_mgmt_params ;-
             ;Bit[1]:     0=UART FC active low, 1=UART FC active high
             ;Bit[16-31]: wakeup timeout in ms
      ACh  hi_board_ext_data           ;\Pointer to extended board Data, and
      B0h  hi_board_ext_data_config    ;/Config/flags (bit0=valid, bit16-31=size)
      B4h  hi_reset_flag               ;\warmboot flags, valid when [B8h]=12345678h
      B8h  hi_reset_flag_valid         ;/
      BCh  hi_hci_uart_pwr_mgmt_params_ext  ;-bit[0-31]: idle timeout in ms
      C0h  hi_acs_flags                     ;-ACS flags
      C4h  hi_console_flags         ;
      C8h  hi_nvram_state           ;
      CCh  hi_option_flag2          ;
      D0h  hi_sw_version_override   ;\If non-zero, override values sent to Host
      D4h  hi_abi_version_override  ;/in WMI_READY event
      D8h  hi_test_apps_related     ;-test applications flags
      DCh  hi_ota_testscript        ;-location of test script
      E0h  hi_cal_data              ;-location of CAL data
      E4h..FFh      ;reserved
      FCh  reserved, but 3DS sets this to 00000003h along hi_board_data_initialized

LOCAL_SCRATCH[0] - AR6K option bits, to enable/disable various features
By default, all option bits are 0.

      AR6K_OPTION_BMI_DISABLE   = 01h  ;bit0 Disable BMI comm with Host
      AR6K_OPTION_SERIAL_ENABLE = 02h  ;bit1 Enable UART serial port TTY messages
      AR6K_OPTION_WDT_DISABLE   = 04h  ;bit2 WatchDog Timer override
      AR6K_OPTION_SLEEP_DISABLE = 08h  ;bit3 Disable system sleep
      AR6K_OPTION_STOP_BOOT     = 10h  ;bit4 Stop boot processes (for ATE)
      AR6K_OPTION_ENABLE_NOANI  = 20h  ;bit5 Operate without ANI
      AR6K_OPTION_DSET_DISABLE  = 40h  ;bit6 Ignore DataSets
      AR6K_OPTION_IGNORE_FLASH  = 80h  ;bit7 Ignore flash during bootup

targaddr[10h] - hi_option_flag

      0     HI_OPTION_TIMER_WAR         ;Enable timer workaround
      1     HI_OPTION_BMI_CRED_LIMIT    ;Limit BMI command credits
      2     HI_OPTION_RELAY_DOT11_HDR   ;Relay Dot11 hdr to/from host
      3     HI_OPTION_MAC_ADDR_METHOD   ;MAC addr method 0=locally administred
                                        ;                1=globally unique addrs
      4     HI_OPTION_ENABLE_RFKILL     ;RF Kill Enable Feature
      5     HI_OPTION_ENABLE_PROFILE    ;Enable CPU profiling
      6     HI_OPTION_DISABLE_DBGLOG    ;Disable debug logging
      7     HI_OPTION_SKIP_ERA_TRACKING ;Skip Era Tracking
      8     HI_OPTION_PAPRD_DISABLE     ;Disable PAPRD (debug)
      9-11  HI_OPTION_NUM_DEV           ;num dev (3bit)
      12-27 HI_OPTION_DEV_MODE          ;dev mode (16bit) (aka 4xMODE, 4xSUBMODE?)
      28    HI_OPTION_NO_LFT_STBL       ;Disable LowFreq LF Timer Stabilization
      29    HI_OPTION_SKIP_REG_SCAN     ;Skip regulatory scan
      30    HI_OPTION_INIT_REG_SCAN     ;Do regulatory scan during init before
                                        ; sending WMI ready event to host
      31    HI_OPTION_FW_BRIDGE         ;Firmware bridging

Two bits of hi_option_flag are used to represent 3 (three?) modes

      HI_OPTION_FW_MODE_IBSS         = 00h   ;IBSS Mode
      HI_OPTION_FW_MODE_BSS_STA      = 01h   ;STA Mode
      HI_OPTION_FW_MODE_AP           = 02h   ;AP Mode
      HI_OPTION_FW_MODE_BT30AMP      = 03h   ;BT30 AMP Mode

Two bits of hi_option flag are used to represent 4 submodes (aka DEV_MODE?)

      HI_OPTION_FW_SUBMODE_NONE      = 00h   ;Normal mode
      HI_OPTION_FW_SUBMODE_P2PDEV    = 01h   ;p2p device mode
      HI_OPTION_FW_SUBMODE_P2PCLIENT = 02h   ;p2p client mode
      HI_OPTION_FW_SUBMODE_P2PGO     = 03h   ;p2p go mode

Fw Mode/SubMode Mask

      .--------.-------.-------.-------.-------.-------.-------.-------.
      |  SUB   |  SUB  |  SUB  | SUB   |       |       |       |       |
      |MODE[3] |MODE[2]|MODE[1]|MODE[0]|MODE[3]|MODE[2]|MODE[1]|MODE[0]|
      |  (2)   |  (2)  |  (2)  |  (2)  |  (2)  |  (2)  |  (2)  |  (2)  |
      '--------'-------'-------'-------'-------'-------'-------'-------'
      HI_OPTION_FW_MODE_BITS         0x2                                    ;\
      HI_OPTION_FW_MODE_MASK         0x3                                    ; MODE
      HI_OPTION_FW_MODE_SHIFT        0xC    ;bit12-13 (2bit) per device?    ;
      HI_OPTION_ALL_FW_MODE_MASK     0xFF   ;bit12-19 (8bit) per 4 devices? ;/
      HI_OPTION_FW_SUBMODE_BITS      0x2                                    ;\
      HI_OPTION_FW_SUBMODE_MASK      0x3                                    ; SUB-
      HI_OPTION_FW_SUBMODE_SHIFT     0x14   ;bit20-21 (2bit) per device?    ; MODE
      HI_OPTION_ALL_FW_SUBMODE_MASK  0xFF00 ;bit20-27 (8bit) per 4 devices? ;
      HI_OPTION_ALL_FW_SUBMODE_SHIFT 0x8                                    ;/

targaddr[CCh] - hi_option_flag2

      0     HI_OPTION_OFFLOAD_AMSDU  ;aka OFFLAOD
      1     HI_OPTION_DFS_SUPPORT              ;-only in newer code from 2011 or so
      2     HI_OPTION_ENABLE_RFKILL            ;\
      3     HI_OPTION_RADIO_RETENTION_DISABLE  ;
      4     HI_OPTION_EARLY_CFG_DONE           ; only in newer code from 2015 or so
      5     HI_OPTION_DISABLE_CDC_MAX_PERF_WAR ;
      6     HI_OPTION_USE_EXT_LDO              ;
      7     HI_OPTION_DBUART_SUPPORT           ;
      8     Reserved?                          ;
      9     HT_OPTION_GPIO_WAKEUP_SUPPORT ;HT? ;/
      10-31 Reserved

targaddr[B4h] - hi_reset_flag (warmboot flags, valid when [B8h]=12345678h)
hi_reset_flag is used to do some stuff when target reset. such as restore app_start after warm reset or preserve host Interest area, or preserve ROM data, literals, etc.

      0     HI_RESET_FLAG_PRESERVE_APP_START     ;preserve App Start address
      1     HI_RESET_FLAG_PRESERVE_HOST_INTEREST ;preserve Host Interest
      2     HI_RESET_FLAG_PRESERVE_ROMDATA       ;preserve ROM data
      3     HI_RESET_FLAG_PRESERVE_NVRAM_STATE
      4     HI_RESET_FLAG_PRESERVE_BOOT_INFO   ;\only in newer code from 2015 or so
      5     HI_RESET_FLAG_WARM_RESET           ;/
      6-31  Reserved

targaddr[C0h] - hi_acs_flags

      0     HI_ACS_FLAGS_ENABLED            ;ACS is enabled
      1     HI_ACS_FLAGS_USE_WWAN           ;Use physical WWAN device
      2     HI_ACS_FLAGS_TEST_VAP           ;Use test VAP
      3-31  Reserved

targaddr[C4h] - hi_console_flags

      0-2   HI_CONSOLE_FLAGS_UART           ;UART ID     (0=Default)
      3     HI_CONSOLE_FLAGS_BAUD_SELECT    ;Baud Select (0=9600, 1=115200)
      4-30  Reserved
      31    HI_CONSOLE_FLAGS_ENABLE         ;Enable Console

targaddr[D8h] - Bitmap for hi_test_apps_related

      0     HI_TEST_APPS_TESTSCRIPT_LOADED
      1     HI_TEST_APPS_CAL_DATA_AVAIL
      2-31  Reserved

Convert a Target virtual address into a Target physical address

      AR6002_VTOP(vaddr)   = ((vaddr) & 0x001fffff)  ;\uh, 2Mbyte space?
      AR6003_VTOP(vaddr)   = ((vaddr) & 0x001fffff)  ;/(shouldn't that be 4Mbyte?)
      MCKINLEY_VTOP(vaddr) = ((vaddr))   ;whatever, maybe uses a different CPU/HW

Override REV2 ROM's app start address (whatever crap, doesn't apply to DSi)

      AR6002_REV2_APP_START_OVERRIDE      0x911A00  ;\
      AR6002_REV2_DATASET_PATCH_ADDRESS   0x52D8B0  ; AR6002
      AR6002_REV2_APP_LOAD_ADDRESS        0x502070  ;/
      AR6003_REV2_APP_START_OVERRIDE      0x944C00  ;\
      AR6003_REV2_APP_LOAD_ADDRESS        0x543180  ;
      AR6003_REV2_BOARD_EXT_DATA_ADDRESS  0x57E500  ; AR6003 REV2
      AR6003_REV2_DATASET_PATCH_ADDRESS   0x57E884  ;
      AR6003_REV2_RAM_RESERVE_SIZE        6912      ;/
      AR6003_REV3_APP_START_OVERRIDE      0x945D20  ;\
      AR6003_REV3_APP_LOAD_ADDRESS        0x545000  ;
      AR6003_REV3_BOARD_EXT_DATA_ADDRESS  0x542330  ; AR6003 REV3
      AR6003_REV3_DATASET_PATCH_ADDRESS   0x57FEC8  ;
      AR6003_REV3_RAM_RESERVE_SIZE        512       ;
      AR6003_REV3_RAM_RESERVE_SIZE_TCMD   4352      ;/

DSi Atheros Wifi - BMI Bootloader Commands

The BMI commands are used to upload the Wifi Firmware to RAM. Doing that is required because the ROM functions themselves aren't fully functional, and the chip can process only BMI commands or WMI commands (not both at once):

      BMI Commands --> After RESET
      WMI Commands --> After uploading and sending BMI_DONE

The AR6002 ROM contains about 40-50% of the program code needed to operate the chip (and most of that ROM code is left unused, until it is getting initialized by the firmware; so the firmware isn't just an "update", it's absolutely required to get the chip working).
DSi Wifi Firmware
On the DSi, the Wifi Firmware is stored in a eMMC file, and it's automatically uploaded by the DSi System Menu (Launcher), so DSi games should be always started with Firmware already installed, and don't need to deal with BMI commands.
DSi SD/MMC Firmware Wifi Firmware
If desired, one could force the chip back to BMI state by issuing a reset, eg. via RESET_CONTROL.Bit8; there might be further ways to issue resets, like SDIO CCCR maybe).
Note: The BMI uploader in DSi is reffering to BMI as "PRE-AUTH" phase, the system menu will be shown even in case of BMI failure, but any such failure will later cause a "WLFIRM 2" error (in sysmenu.log) at time when trying to start a title from within system menu.
BMI Transfer
Before each BMI command, wait for LOCAL_COUNT[4] to become nonzero. Then, write the command and parameters to MBOX0. Then read the response (if any) from MBOX0 (ideally with checking MBOX empty flag before reading response bytes; DSi code doesn't seem to do that though - maybe the SDIO controller is automatically waiting while MBOX empty?).

     ____________________________ Execute Functions ____________________________

BMI_CMD(01h) - BMI_DONE - Launch Firmware

      Send 32bit Command (00000001h)

Starts the firmware by calling its entrypoint. The default entry is 915000h for AR6002G (or 927000h for AR6013G and AR6014G), alternately a custom entrypoint can be set via BMI_CMD(05h).
BMI_CMD(04h) - BMI_EXECUTE - Execute

      Send 32bit Command (00000004h)
      Send 32bit Entrypoint
      Send 32bit Argument
      Receive 32bit Return Value

Calls a function on Xtensa CPU. On DSi, this is used to execute the boot stub (for reading the I2C EEPROM data). The main firmware should be started via BMI_DONE, not via BMI_EXECUTE.
BMI_CMD(05h) - BMI_SET_APP_START - Set App Start

      Send 32bit Command (00000005h)
      Send 32bit Entrypoint

Changes the default entrypoint for BMI_DONE. The DSi doesn't use this feature (and uses the default entrypoint).

     ___________________________ Read/Write Functions ___________________________

BMI_CMD(02h) - BMI_READ_MEMORY - Read Memory

      Send 32bit Command (00000002h)
      Send 32bit Address
      Send 32bit Length (should be max 80h or 200h or so (?) due to MBOX size)
      Receive LEN bytes, read from [address and up]

Allows to read Xtensa RAM or ROM in byte-units (I/O ports should be read in 32bit units, via BMI_READ_SOC_REGISTER).
BMI_CMD(03h) - BMI_WRITE_MEMORY - Write Memory

      Send 32bit Command (00000003h)
      Send 32bit Address (or special value for "Segmented Write", see below)
      Send 32bit Length (should be max 1F4h due to MBOX size)
      Send LEN bytes, written to [address and up]

Allows to write Xtensa RAM. Used to upload the stub and data parts of the firmware (the main part of the firmware is uploaded via BMI_LZ_xxx functions).
BMI_CMD(06h) - BMI_READ_SOC_REGISTER - Read Register

      Send 32bit Command (00000006h)
      Send 32bit Address
      Receive 32bit Word from [address]

Allows to read Xtensa I/O Ports (or RAM or ROM) in 32bit-units. The same effect can be gained via WINDOW_DATA register (which is also working when the Xtensa CPU isn't in BMI bootloader state).
BMI_CMD(07h) - BMI_WRITE_SOC_REGISTER - Write Register

      Send 32bit Command (00000007h)
      Send 32bit Address
      Send 32bit Word to [address]

Allows to write Xtensa I/O Ports (or RAM) in 32bit-units.
BMI_CMD(0Dh) - BMI_LZ_STREAM_START - LZ Uncompress Stream Start

      Send 32bit Command (0000000Dh)
      Send 32bit Destination Start Address for BMI_CMD(0Eh)

Sets the destination start address for following BMI_LZ_DATA command(s). Also resets the decompressor to expect the "tag" value in first byte.
BMI_CMD(0Eh) - BMI_LZ_DATA - LZ Data Input

      Send 32bit Command (0000000Eh)
      Send 32bit Length (should be max 1F8h due to MBOX size)
      Send LEN compressed bytes, decompressed to incrementing destination address

     ___________________________ ROM Patch Functions ___________________________

ROM Patches using the hardware's TCAM/BCAM registers (implemented in hardware, but not actually used by DSi firmware).
BMI_CMD(09h) - BMI_ROMPATCH_INSTALL - TCAM/BCAM_xxxxx

      Send 32bit Command (00000009h)
      Send 32bit Target ROM Address
      Send 32bit Target RAM Address or Value (depending on Target Type)
      Send 32bit Size (in bytes)
      Send 32bit Activate (0=Install without activate, 1=Install and activate)
      Receive 32bit PatchID

The DSi/3DS do contain TCAM hardware. The TCAM hardware's eight size settings are probably 20h,40h,80h,100h,200h,400h,800h,1000h. For the BCAM hardware, the size must be probably always set to 04h.
BMI_CMD(0Ah) - BMI_ROMPATCH_UNINSTALL - TCAM/BCAM_Clr_index_and_xxx
Uninstall (and deactivate) a previously-installed ROM Patch.

      Send 32bit Command (0000000Ah)
      Send 32bit PatchID (to be uninstalled & deactivated)

BMI_CMD(0Bh) - BMI_ROMPATCH_ACTIVATE - TCAM/BCAM_Set_indices
BMI_CMD(0Ch) - BMI_ROMPATCH_DEACTIVATE - TCAM/BCAM_Clr_indices
Activate/Deactivate a list of previously-installed ROM Patches.

      Send 32bit Command (0000000Bh/0000000Ch)
      Send 32bit Number of patches (N)
      Send Nx32bit List of PatchID's (to be activated/deactivated)

     ______________________________ Misc Functions ______________________________

BMI_CMD(08h) - BMI_GET_TARGET_ID aka BMI_GET_TARGET_INFO - Get Version

      Send 32bit Command (00000008h)
      Receive 32bit Value (FFFFFFFFh) ;ROM version (or FFFFFFFFh)
     If above value is FFFFFFFFh then following extra data is appended:
      Receive 32bit Value (0000000Ch) ;total size of extra data
      Receive 32bit Value (20000188h) ;ROM version
      Receive 32bit Value (00000002h) ;TARGET_TYPE (2=AR6002)

BMI_CMD(0Fh) - BMI_NVRAM_PROCESS ;not implemented in DSi, Invalid (ignored)
Unknown purpose, said to "process or execute" something in "NVRAM" with a name in "LE format":
"Cause Target to search NVRAM (if any) for a segment with the specified name and process it according to NVRAM metadata."

      Send 32bit Command (0000000Fh)
      Send 16x8bit Name (16 characters, in "LE format", uh?)
      Receive 32bit Value returned from last executed NVRAM segment (or 0=None)

BMI_CMD(00h) - BMI_NO_COMMAND - Invalid (ignored)
BMI_CMD(0Fh..FFFFFFFFh) - N/A - Invalid (ignored)

      Send 32bit Command (00000000h, or 0000000Fh..FFFFFFFFh)

Segmented Write
The Segmented Write feature is implemented only in newer ROMs (not in DSi with AR6002). It is invoked via BMI_CMD(03h) with destination address set to special value 00001234h.

      Send 32bit Command (00000003h) <-- same as Write Memory command
      Send 32bit Address (00001234h) <-- special value for Segmented Write
      Send 32bit Length (should be max 1F4h due to MBOX size)
      Send LEN bytes, as described below...

The transferred data should contain a file header:

      00h 4    File ID (544D4753h) ("SGMT")
      04h 4    File Flags (0=Raw, 1=BMI_SGMTFILE_FLAG_COMPRESS)

Followed by one or more segments:

      00h 4    Destination Address (the actual address, no special value here)
      04h 4    Segment Length (N) (or special value FFFFFFFxh)
      08h N    Data (N bytes)     (no data when N=FFFFFFFxh)

Special values for "Segment Length" (all with bit31=1):

      FFFFFFFFh ;End of segmented data file (should occur as last segment)
      FFFFFFFEh ;Board Data (write "hi_board_data+Address", instead raw "Address")
      FFFFFFFDh ;Set App Start=Addresss; like BMI_CMD(05h)
      FFFFFFFCh ;Call Address; like BMI_CMD(04h), but without param/return value

Compressed Segmented data is said to work in two ways (?):

      1) Use BMI_LZ_STREAM_START with Addr=00001234h, followed by BMI_LZ_DATA, or
      2) Use BMI_WRITE_MEMORY with Addr=00001234h and file header Flags=1.

Atheros has invented that weird feature for "backwards compatibility & darn convenience", which is both sad and funny because Atheros is definitely unable to <maintain> backwards compatibility (such as keeping the same WMI command/event numbering in firmware revisions), but as it seems, Atheros is believing that "backwards compatibility" is something that can be <invented> by adding obscure features.

DSi Atheros Wifi - MBOX Transfer Headers

MBOX transfers include a small header for distinguishing between Data Packets and Commands/Events, and for indicating the actual length (as opposed to the MBOX transfer length, which is usually garbage-padded to 80h-byte boundary).
The exception are BMI Bootloader commands/responses (which don't have such headers or padding).
SDIO Functions used after BMI init

      Func[0:00005h]        R   1     Interrupt Flags (bit1=Function 1 IRQ)
      Func[1:00400h]        R   10h   Interrupt Status, etc. and Lookahead
      Func[1:00800h..00FFF] R/W ..    MBOX0

MBOX Send Header/Body

      00h 1    Type        (00h=BootInfo, 01h=WMI Command, 02h=Data Packet)
      01h 1    Request Ack (00h=No, 01h=Yes)
      02h 2    Length of entries [06h..end]  (LEN)
      04h 2    ?
      06h LEN  Body (BootInfo/Event/Data)
      ..  ..   Padding to 80h-byte boundary (for SDIO block size 80h)

Send Body for BootInfo:

      06h ..   related to BE/BK/VI/VO stuff (best effort, background, video, voice)

Send Body for WMI Commands:

      06h 2  WMI Command Number
      08h .. Parameters

Send Body for Data Packets:

      06h 2  <Unknown6>?? 0000h or 1C00h    ;maybe whatever ?
      08h 6  Destination (MAC Addr of Router) (or FF:FF:FF:FF:FF:FF=Broadcast)
      0Eh 6  Source      (MAC Addr of DSi console)
      14h 2  Length Data at [16h...]  ;(LEN1-10h)   ;<-- BIG-ENDIAN !!!
      16h .. Data (usually starting with LLC stuff, ie. AAh,AAh,03h,00h...)

Send Body for empty Data Packets (used when changing WPA/WPA2 CIPHER keys):

      06h 1  Garbage (usually LSB of a previously used WMI command number)
      07h 1  Unknown (02h)

MBOX Receive Header/Body

      00h      1    Type        (00h=Ack only, 01h=WMI Event, 02h=Data Packet)
      01h      1    Ack Present (00h=No, 02h=Yes)
      02h      2    Length of entries [06h..end]     (LEN1+LEN2)
      04h      1    Length of Ack at [06h+LEN1..end] (LEN2) ;garbage when [01h]=00h
      05h      1    ? (00h,20h?,7Fh,F4h,FFh)
      06h      LEN1 Body (Event/Data)
      06h+LEN1 LEN2 Ack List
      ..       ..   Padding to 80h-byte boundary (for SDIO block size 80h)

Receive Body for Ack only:

      06h -  N/A (or boot request info; occurs only shortly after BMI)

Receive Body for Events:

      06h 2  WMI Event Number
      08h .. Parameters

Receive Body for Data Packets:

      06h 1  RSSI (Received Signal Strength Indicator) (00h..3Ch) (aka 0..60)
      07h 1  <Unknown7> 00h
      08h 6  Destination (MAC Addr of DSi console) (or FF:FF:FF:FF:FF:FF=Broadcast)
      0Eh 6  Source      (MAC Addr of Router)
      14h 2  Length of Data entries at [16h..(end-xtracrap)]   ;<-- BIG-ENDIAN !!!
      16h .. Data (usually LLC stuff, ie. AAh,AAh,03h.. or, once F0h,F0h,03h..??)

Ack List (aka Trailer) (can contain multiple List items):

      X+00h  List Item Type (01h=Ack, 02h=Lookahead)
      X+01h  List Item Len (02h*N for Ack's, 06h for Lookahead)
      X+02h  List Item data

Ack Items (can contain multiple Ack items):

      Y+00h  Ack Item Type (01h=Command Ack, 02h=Data Ack, 05h=Data Ack, too?)
      Y+01h  Ack Item Count? (usually 1) (or 2 for double-ack?)

Lookahead Item (if valid: allows to omit reading Func[1:00408h]):

      Z+00h  Lookahead valid ID1 (00h=No, 55h=Valid)
      Z+01h  Lookahead MBOX0 (or garbage if ID1/ID2 not valid)
      Z+05h  Lookahead valid ID2 (00h=No, AAh=Valid)

Notes
The send/receive DATA headers are apparently containing incomplete wifi "Frame Headers":

      without 3rd address field
      without WEP entries (those are apparently automatically inserted)
      without Frame Control, Duration/ID, Sequence Control
      there seem to be only Data Frames (no Managment/Control Frames)

That, unless some of the missing info would be encoded in the <Unknown> header entries.

DSi Atheros Wifi - WMI Misc Commands

WMIcmd(0004h) - WMI_SYNCHRONIZE_CMD
Parameters (01h bytes):

      00h  A_UINT8  1  dataSyncMap          ;00h, 01h, or 09h used?

WMIcmd(0009h) - WMI_SET_BSS_FILTER_CMD ;aka WMI_BSS_FILTER_CMD
Parameters (08h bytes):

      00h  A_UINT8  1  bssFilter;                      /* see WMI_BSS_FILTER
      01h  A_UINT8  1  reserved1;                      /* For alignment
      02h  A_UINT16 2  reserved2;                      /* For alignment
      04h  A_UINT32 4  ieMask;

WMI_BSS_FILTER values:

      NONE_BSS_FILTER        = 00h  ;no beacons forwarded
      ALL_BSS_FILTER         = 01h  ;all beacons forwarded
      PROFILE_FILTER         = 02h  ;only beacons matching profile
      ALL_BUT_PROFILE_FILTER = 03h  ;all but beacons matching profile
      CURRENT_BSS_FILTER     = 04h  ;only beacons matching current BSS
      ALL_BUT_BSS_FILTER     = 05h  ;all but beacons matching BSS
      PROBED_SSID_FILTER     = 06h  ;beacons matching probed ssid
      LAST_BSS_FILTER        = 07h  ;marker only

WMIcmd(000Ah) - WMI_SET_PROBED_SSID_CMD
Parameters (23h bytes):

      00h  A_UINT8  1   entryIndex;      /* 0 to MAX_PROBED_SSID_INDEX
      01h  A_UINT8  1   flag;            /* WMI_SSID_FLG
      02h  A_UINT8  1   ssidLength;
      03h  A_UINT8  32  ssid[32];

#define MAX_PROBED_SSID_INDEX = 15
WMI_SSID_FLAG values:

      DISABLE_SSID_FLAG  = 00h    /* disables entry
      SPECIFIC_SSID_FLAG = 01h    /* probes specified ssid
      ANY_SSID_FLAG      = 02h    /* probes for any ssid

WMIcmd(000Bh) - WMI_SET_LISTEN_INT_CMD
Parameters (04h bytes):

      00h  A_UINT16 2   listenInterval;
      02h  A_UINT16 2   numBeacons;

The Listen interval is between 15 and 3000 TUs

      MIN_LISTEN_INTERVAL = 15     ;min = 15
      MAX_LISTEN_INTERVAL = 5000   ;max = 5000 or 3000, uh?
      MIN_LISTEN_BEACONS  = 1
      MAX_LISTEN_BEACONS  = 500

WMIcmd(000Ch) - WMI_SET_BMISS_TIME_CMD
Parameters (04h bytes):

      00h  A_UINT16 2   bmissTime;
      02h  A_UINT16 2   numBeacons;

Valid values are between 1000 and 5000 TUs

      MIN_BMISS_TIME    = 1000
      MAX_BMISS_TIME    = 5000
      MIN_BMISS_BEACONS = 1
      MAX_BMISS_BEACONS = 50

WMIcmd(000Fh) - WMI_SET_BEACON_INT_CMD
Parameters (02h bytes):

      00h  A_UINT16 2    beaconInterval;

WMIcmd(001Ah) - WMI_SET_PMKID_CMD
Parameters:

      00h  A_UINT8  6   bssid[ATH_MAC_LEN];
      06h  A_UINT8  1   enable;                 /* PMKID_ENABLE_FLG
      07h  A_UINT8  16  pmkid[WMI_PMKID_LEN];

#define WMI_PMKID_LEN = 16
PMKID_ENABLE_FLG values:

      PMKID_DISABLE = 0
      PMKID_ENABLE  = 1

WMIcmd(001Dh) - WMI_SET_ASSOC_INFO_CMD
Parameters:

      00h  A_UINT8  1   ieType
      01h  A_UINT8  1   bufferSize
      02h  A_UINT8  N*1 assocInfo[1]         ;up to WMI_MAX_ASSOC_INFO_LEN

A maximum of 2 private IEs can be sent in the [Re]Assoc request.
A 3rd one, the CCX version IE can also be set from the host.

      WMI_MAX_ASSOC_INFO_TYPE   = 2
      WMI_CCX_VER_IE            = 2   /* ieType to set CCX Version IE
      WMI_MAX_ASSOC_INFO_LEN    = 240

WMIcmd(001Eh) - WMI_ADD_BAD_AP_CMD
Parameters (07h bytes):

      00h  A_UINT8  1  badApIndex            ;0 to WMI_MAX_BAD_AP_INDEX
      01h  A_UINT8  6  bssid[ATH_MAC_LEN]
     WMI_MAX_BAD_AP_INDEX     = 1

WMIcmd(001Fh) - WMI_DELETE_BAD_AP_CMD
Parameters (01h bytes):

      00h  A_UINT8  1  badApIndex            ;0 to WMI_MAX_BAD_AP_INDEX

WMIcmd(0023h) - WMI_SET_ACCESS_PARAMS_CMD
Parameters:

      00h  A_UINT16 2  txop           ;in units of 32 usec
      02h  A_UINT8  1  eCWmin
      03h  A_UINT8  1  eCWmax
      04h  A_UINT8  1  aifsn
      05h  A_UINT8  1  ac
     WMI_DEFAULT_TXOP_ACPARAM   = 0       /* implies one MSDU
     WMI_DEFAULT_ECWMIN_ACPARAM = 4       /* corresponds to CWmin of 15
     WMI_DEFAULT_ECWMAX_ACPARAM = 10      /* corresponds to CWmax of 1023
     WMI_MAX_CW_ACPARAM         = 15      /* maximum eCWmin or eCWmax
     WMI_DEFAULT_AIFSN_ACPARAM  = 2
     WMI_MAX_AIFSN_ACPARAM      = 15

WMIcmd(0025h) - WMI_SET_OPT_MODE_CMD
Parameters (01h bytes on DSi?, but parameter structure is undocumented):

      00h  A_UINT8     optMode (documented in code from 2008 only)

OPT_MODE_TYPE values:

      SPECIAL_OFF      = unknown (maybe 0 or 1 or so)  ;\
      SPECIAL_ON       = SPECIAL_OFF+1                 ; code from 2008 only
      PYXIS_ADHOC_ON   = SPECIAL_OFF+2                 ; (removed/undoc in 2010)
      PYXIS_ADHOC_OFF  = SPECIAL_OFF+3                 ;/

WMIcmd(0026h) - WMI_OPT_TX_FRAME_CMD
Unknown/undocumented purpose. Unknown if/how this is implemented in DSi. The DSi does redirect cmd 0026h to a function handler, but that handler does just trigger a misalign exception. However, the DSi does also have a function for handling the command (with "opt_tx_frame_cmd" string in AR6013/AR6014), but that function doesn't seem to be called upon command number 0026h. Maybe the CMD is triggered upon special flags in the SDIO transfer block header, rather than by the command number?
Parameters (11h bytes on DSi)

      Unknown (11h bytes, but parameter structure is undocumented)

See also: WMI_OPT_RX_FRAME_EVENT (counterpart in opposite direction), and WMI_SET_OPT_MODE_CMD.
WMIcmd(0027h) - WMI_SET_VOICE_PKT_SIZE_CMD
Parameters (02h bytes):

      00h  A_UINT16 2   voicePktSize

WMIcmd(0028h) - WMI_SET_MAX_SP_LEN_CMD
Parameters (01h bytes):

      00h  A_UINT8  1  maxSPLen

APSD_SP_LEN_TYPE values:

        DELIVER_ALL_PKT = 00h
        DELIVER_2_PKT   = 01h
        DELIVER_4_PKT   = 02h
        DELIVER_6_PKT   = 03h

WMIcmd(002Eh) - WMI_EXTENSION_CMD ;prefix for WMIX "Non-wireless extensions"
Parameters:

      00h  UNIT32?  4    WMIX Command (values 2001h and up)  ;WMIX_CMD_HDR
      04h  ...      ..   WMIX Parameter(s)

Prefix for WMIX commands.
WMIcmd(002Eh:2008h) - WMIX_HB_CHALLENGE_RESP_CMD ;reply=3007h ;HB=heartbeat

      00h  A_UINT32 4    cookie    ;usually increasing 1,2,3,4,5,etc.
      04h  A_UINT32 4    source    ;usually 0

Heartbeat Challenge Response command, this is said to be an "Error Detection support" feature.
There's also a WMI_SET_HB_CHALLENGE_RESP_PARAMS_CMD structure defined in wmi.h (not in wmix.h):

      00h  A_UINT32 frequency    ;\unknown purpose, sounds like command/params,
      04h  A_UINT8  threshold    ;/but there's no WMIcmd(xxxxh) value assigned

See also: WMIX_HB_CHALLENGE_RESP_EVENT
WMIcmd(0031h) - WMI_SET_LPREAMBLE_CMD
Parameters (01h bytes on DSi?, but other sources claim 02h bytes):

      01h 02h   <---- total size (on DSi it's 01h, ie. left column)
      00h 00h  A_UINT8  1   status
      --  01h  A_UINT8  1   preamblePolicy

WMI_LPREAMBLE_STATUS values:

      WMI_LPREAMBLE_DISABLED = 0
      WMI_LPREAMBLE_ENABLED  = 1

WMI_PREAMBLE_POLICY values:

      WMI_IGNORE_BARKER_IN_ERP       = 0
      WMI_DONOT_IGNORE_BARKER_IN_ERP = 1

WMIcmd(0032h) - WMI_SET_RTS_CMD
Parameters (02h bytes):

      00h  A_UINT16 2   threshold

WMIcmd(0036h) - WMI_SET_AUTH_MODE_CMD ;aka WMI_SET_RECONNECT_AUTH_MODE_CMD
Parameters (01h bytes):

      00h  A_UINT8  1   mode

WMI_AUTH_MODE values:

      RECONN_DO_AUTH  = 00h
      RECONN_NOT_AUTH = 01h

Set authentication mode
WMIcmd(0037h) - WMI_SET_REASSOC_MODE_CMD
Parameters (01h bytes):

      00h  A_UINT8  1   mode

WMI_REASSOC_MODE values:

      REASSOC_DO_DISASSOC    = 00h
      REASSOC_DONOT_DISASSOC = 01h

Set authentication(?) mode (uh, so SET_REASSOC is same as SET_AUTH?)
WMIcmd(0038h) - WMI_SET_WMM_CMD
Parameters (01h bytes):

      00h  A_UINT8  1   status

WMI_WMM_STATUS values:

      WMI_WMM_DISABLED = 0
      WMI_WMM_ENABLED  = 1

WMM stands for Wi-Fi Multimedia (WMM) aka Wireless Multimedia Extensions (WME) aka some QOS related stuff?
"WMM prioritizes traffic according to four Access Categories (AC): voice (AC_VO), video (AC_VI), best effort (AC_BE), and background (AC_BK)."
WMIcmd(0039h) - WMI_SET_WMM_TXOP_CMD
Parameters (01h bytes):

      00h  A_UINT8  1   txopEnable

WMI_TXOP_CFG values:

      WMI_TXOP_DISABLED = 0
      WMI_TXOP_ENABLED  = 1

WMIcmd(003Dh) - WMI_SET_KEEPALIVE_CMD
Parameters (01h bytes):

      00h  A_UINT8  1   keepaliveInterval

WMIcmd(003Eh) - WMI_GET_KEEPALIVE_CMD ;reply 003Eh
Parameters (claimed to be as so?):

        A_BOOL   4   configured
        A_UINT8  1   keepaliveInterval

Uh, the command does probably not have any parameters at all, and above is probably meant to be the Reply structure, not the Parameter structure?
WMIcmd(003Fh) - WMI_SET_APPIE_CMD ;aka WMI_SET_APP_IE_CMD
Can be used to add custom Information Elements (IE) to beacons?
Parameters (old=2+N bytes, or new=4+N bytes):

     Older version (used on DSi, and on older 3DS firmwares):
      00h  A_UINT8  1    mgmtFrmType ;one of WMI_MGMT_FRAME_TYPE
      01h  A_UINT8  1    ieLen     ;Length of the IE to be added to the MGMT frame
      02h  A_UINT8  N*1  ieInfo[1] ;
     Newer version (used on newer 3DS firmwares):
      00h  A_UINT8  1    mgmtFrmType ;one of WMI_MGMT_FRAME_TYPE
      01h  A_UINT8  1    reserved (zero, actually USED as MSB of above type value)
      02h  A_UINT16 2    ieLen     ;Length of the IE to be added to the MGMT frame
      04h  A_UINT8  N*1  ieInfo[1]

WMI_MGMT_FRAME_TYPE values:

      WMI_FRAME_BEACON     = 0   ;\old version (with 8bit ieLen):
      WMI_FRAME_PROBE_REQ  = 1   ;  supports type 0,1,2,3,4 (or 5..FFh=same as 4)
      WMI_FRAME_PROBE_RESP = 2   ; new version (with 16bit ieLen):
      WMI_FRAME_ASSOC_REQ  = 3   ;  supports type 1,3 only (ignores all other)
      WMI_FRAME_ASSOC_RESP = 4   ;/

Add Application specified IE to a management frame

      WMI_MAX_IE_LEN = 78    ;older versions (with 8bit ieLen) ;<-- actual limit
      WMI_MAX_IE_LEN = 255   ;older versions (with 8bit ieLen) ;<-- incorrect
      WMI_MAX_IE_LEN = 1024  ;newer versions (with 16bit ieLen) (from 2014)

Uh, if that newer 3DS firmware is also used in DSi mode (?) then the changed parameter format would be incompatible with DSi software (the APPIE command is rarely (perhaps never) used though).
WMIcmd(0041h) - WMI_SET_WSC_STATUS_CMD ;aka WSC_REG
Parameters:

      Unknown (none? or maybe UINT8 or so, maybe with values listed below)
      DSi uses 1 byte parameter.
     WSC_REG_ACTIVE   = 1
     WSC_REG_INACTIVE = 0

Notify the WSC registration status to the target.
WSC means Wifi Simple Config?
WMIcmd(0049h) - WMI_HOST_EXIT_NOTIFY_CMD ;special DSi/3DS command
Parameters:

      None

This is apparently a special nintendo command, supported on DSi and 3DS (supported on AR6002/AR6013/AR6014, whereof, AR6013/AR6014 have it bundled with a "wmi_host_exit_notify_cmd" message, so, this is apparently not the official WMI_SET_QOS_SUPP_CMD from atheros).
WMIcmd(0049h) - WMI_SET_QOS_SUPP_CMD ;not implemented in DSi/3DS...?
Parameters:

      00h  A_UINT8  1   status;

QOS or QoS stands for "Quality of service"?
Note: Some older source code from 2008 did have this command accidently inserted between WMIcmd(0039h and 003Ah), thereby smashing the numbering for WMIcmd(003Ah..004xh), that issue is fixed in newer source code from 2010.
...Developer commands...
WMIcmd(F002h) - WMI_SET_WHALPARAM_CMD ;aka WHAL_PARAMCMD
Parameters:

      00h  A_UINT8  1   whalCmdId;    ;see WHAL_CMDID enumeration
      01h  A_UINT8  ..  data[1];      ;aka SETCABTO structure ?

Generic Hal Interface for setting hal parameters.
Add new Set HAL Param cmdIds here for newer params.
WHAL_CMDID values (only one defined):

      WHAL_SETCABTO_CMDID = 1

WHAL_SETCABTO_PARAM structure:

      A_UINT8 cabTimeOut;

WMIcmd(F004h, or formerly 0048h) - WMI_SET_AKMP_PARAMS_CMD
Parameters (04h bytes):

      00h  A_UINT32 4  akmpInfo;

WMI_AKMP_MULTI_PMKID_EN = 000001h
WMIcmd(F005h, or formerly 0049h) - WMI_SET_PMKID_LIST_CMD
Parameters (01h bytes on DSi?, but below would be 4+N*? bytes?):

      00h  A_UINT32  4     numPMKID;
      04h  WMI_PMKID N*..  pmkidList[WMI_MAX_PMKID_CACHE];

#define WMI_MAX_PMKID_CACHE = 8
WMI_PMKID structure:

      A_UINT8  pmkid[WMI_PMKID_LEN];

WMIcmd(F006h, or formerly 004Ah) - WMI_GET_PMKID_LIST_CMD ;reply 1019h
Parameters:

      Unknown (none?)

Reply: WMI_GET_PMKID_LIST_EVENT ;aka WMI_PMKID_LIST_REPLY

      00h  A_UINT32  4    numPMKID;
      04h  A_UINT8   N*6  bssidList[ATH_MAC_LEN][1];
      ..   WMI_PMKID N*1  pmkidList[1];

"Following the Number of PMKIDs is the list of PMKIDs" uh, what exactly?
WMI_PMKID structure:

        A_UINT8 pmkid[WMI_PMKID_LEN];

DSi Atheros Wifi - WMI Misc Events

WMIevent(000Eh) - WMI_GET_CHANNEL_LIST_CMD
WMIevent(001Ch) - WMI_GET_TX_PWR_CMD
WMIevent(0035h) - WMI_GET_FIXRATES_CMD
WMIevent(003Eh) - WMI_GET_KEEPALIVE_CMD
WMIevent(F001h) - WMI_GET_BITRATE_CMD
Events/Responses with same ID as corresponding command.
See corresponding commands for description of reply data.
WMIevent(1001h) - WMI_READY_EVENT
This event exists with numerous (incorrect) definitions, claiming the event data to be 07h, 0Bh, 0Ch, 0Fh, or 10h bytes in length:
Event Data (0Ch bytes on DSi, as returned by DSi firmware):

      00h  A_UINT8  6  macaddr[ATH_MAC_LEN]   ;MAC addr of DSi console
      06h  A_UINT8  1  phyCapability    (=02h aka "11G")  ;WMI_PHY_CAPABILITY
      07h  A_UINT8  1  unused/padding
      08h  A_UINT32 4  version (=2100007Bh/2300006Ch) (firmware version)

Event Data (07h bytes, exists in AR6002 ROM, but overridden by DSi firmware):

      00h  A_UINT8  6  macaddr[ATH_MAC_LEN]
      06h  A_UINT8  1  phyCapability                      ;WMI_PHY_CAPABILITY

Event Data (0Bh bytes, accidently claimed to be so in source code from 2008):

      00h  A_UINT32 4  version
      04h  A_UINT8  6  macaddr[ATH_MAC_LEN]
      0Ah  A_UINT8  1  phyCapability                      ;WMI_PHY_CAPABILITY

Event Data (0Fh bytes, accidently claimed to be so in source code from 2010):

      00h  A_UINT32 4  sw_version
      04h  A_UINT32 4  abi_version
      08h  A_UINT8  6  macaddr[ATH_MAC_LEN]
      0Eh  A_UINT8  1  phyCapability                      ;WMI_PHY_CAPABILITY

Event Data (10h bytes, as done by 3DS function in wifi firmware RAM):

      00h  A_UINT8  6  macaddr[ATH_MAC_LEN]   ;MAC addr of DSi console
      06h  A_UINT8  1  phyCapability    (=02h aka "11G")  ;WMI_PHY_CAPABILITY
      07h  A_UINT8  1  unused/padding
      08h  A_UINT32 4  version (230000B3h) (firmware version)
      0Ch  A_UINT16 2  whus         ;=[004134h] ;some I/O register ???
      0Eh  A_UINT16 2  what         ;=[520088h] ;hi_hci_uart_baud  ???

WMI_PHY_CAPABILITY values (maybe the "11" is related to "IEEE 802.11"?):

      WMI_11A_CAPABILITY   = 1
      WMI_11G_CAPABILITY   = 2
      WMI_11AG_CAPABILITY  = 3
      WMI_11NA_CAPABILITY  = 4
      WMI_11NG_CAPABILITY  = 5
      WMI_11NAG_CAPABILITY = 6

WMIevent(1004h) - WMI_BSSINFO_EVENT aka WMI_BSS_INFO
Event Data (0Ch+N bytes or 10h+N bytes on DSi, depending on version setting):

     When version<2:
      00h  A_UINT16 2   channel      ;in MHz                ;\
      02h  A_UINT8  1   frameType    ;see WMI_BI_FTYPE      ;
      03h  A_UINT8  1   snr      ;eg. 33h                   ; WMI_BSS_INFO_HDR
      04h  A_INT16  2   rssi     ;eg. FFD4h aka "33h-95"    ; version 1 (10h bytes)
      06h  A_UINT8  6   bssid[ATH_MAC_LEN]                  ;
      0Ch  A_UINT32 4   ieMask                              ;/
      10h  BODY     ... beacon or probe-response frame body ;-Body (timestamp etc)
     When version>=2:
      00h  A_UINT16 2   channel      ;in MHz                ;\
      02h  A_UINT8  1   frameType    ;see WMI_BI_FTYPE      ; WMI_BSS_INFO_HDR2
      03h  A_UINT8  1   snr   (implies "rssi=snr-95" in v2) ; version 2 (0Ch bytes)
      04h  A_UINT8  6   bssid[ATH_MAC_LEN]                  ;
      0Ah  A_UINT16 2   ieMask         (only 2 bytes in v2) ;/
      0Ch  BODY     ... beacon or probe-response frame body ;-Body (timestamp etc)

BUG: The "snr" value can be negative, but isn't sign-expanded to 16bit, and the and the rssi value at [04h] does then contain nonsense (eg. spotted bytes at[03h..05h] are "FC 9D 00").
The BODY starts with 64bit Timestamp, 16bit BeaconInterval, etc. For details, see:
DS Wifi IEEE802.11 Managment Frames (Type=0)
The size of the BODY varies per access point (from around 64 bytes to exceeding 256 bytes).
The DSi firmware contains code for both of the above HDR versions (unknown if/when/how it does use which version; the DSi Browser receives the older type, with 10h+N bytes).
BSS Info Event.
Mechanism used to inform host of the presence and characteristic of wireless networks present. Consists of bss info header followed by the beacon or probe-response frame body. The 802.11 header is not included.
BSS INFO HDR version 2.0:
With 6 bytes HTC header and 6 bytes of WMI header WMI_BSS_INFO_HDR cannot be accomodated in the removed 802.11 management header space.

      - Reduce the ieMask to 2 bytes as only two bit flags are used
      - Remove rssi and compute it on the host. rssi = snr - 95

WMI_BI_FTYPE values:

      BEACON_FTYPE      = 01h
      PROBERESP_FTYPE   = 02h
      ACTION_MGMT_FTYPE = 03h
      PROBEREQ_FTYPE    = 04h

BSS_ELEMID values (unclear WHAT that is, maybe the "ieMask" stuff, which said to use "two bit flags"):

      BSS_ELEMID_CHANSWITCH = 01h    ;value for bit0? (or bit-number for bit1?)
      BSS_ELEMID_ATHEROS    = 02h    ;value for bit1? (or bit-number for bit2?)

WMIevent(1006h) - WMI_REGDOMAIN_EVENT ;aka WMI_REG_DOMAIN_EVENT
Event Data (04h bytes):

      00h  A_UINT32 4   regDomain  ;80000188h on DSi (after firmware upload)

New Regulatory Domain Event.
Value 80000188h on DSi/AR6002 and 80000348h on DSi/AR6013 (these are based on the wifi firmware's "RGBD" DataSet, with 0188h="JP" and 0348h="US").
The country code seems to be derived from I2C EEPROM[008h], and the database is used to translate the country code to enabled channels.
WMIevent(1008h) - WMI_NEIGHBOR_REPORT_EVENT
Event Data:
typedef PREPACK struct {

      00h  A_INT8              1     numberOfAps;
      01h  WMI_NEIGHBOR_INFO   N*7   neighbor[1];

WMI_NEIGHBOR_INFO structure:

        A_UINT8 6    bssid[ATH_MAC_LEN];
        A_UINT8 1    bssFlags;            /* see WMI_BSS_FLAGS

WMI_BSS_FLAGS values:

      WMI_DEFAULT_BSS_FLAGS   = 00h
      WMI_PREAUTH_CAPABLE_BSS = 01h
      WMI_PMKID_VALID_BSS     = 02h

The WMI_NEIGHBOR_REPORT Event is generated by the target to inform the host of BSS's it has found that matches the current profile.
It can be used by the host to cache PMKs and/to initiate pre-authentication if the BSS supports it. The first bssid is always the current associated BSS.
The bssid and bssFlags information repeats according to the number or APs reported.
WMIevent(100Eh) - WMI_OPT_RX_FRAME_EVENT aka WMI_OPT_RX_INFO
Event Data (10h+N bytes):

      00h  A_UINT16 2   channel                        ;\
      02h  A_UINT8  1   frameType  ;see WMI_OPT_FTYPE  ; special frame info header
      03h  A_INT8   1   snr                            ;
      04h  A_UINT8  6   srcAddr[ATH_MAC_LEN]           ;
      0Ah  A_UINT8  6   bssid[ATH_MAC_LEN]             ;/
      10h  ...      ..  body (having WHAT length?)     ;-special frame body

Special frame receive Event.
Mechanism used to inform host of the receiption of the special frames.
The 802.11 header is not included.
See also: WMI_OPT_TX_FRAME_CMD
WMIevent(1010h) - WMI_EXTENSION_EVENT ;prefix for WMIX events...
Unknown, probably similar prefix as "WMIX_CMD_HDR" with 32bit WMIX value.
WMIevent(1010h:3007h) - WMIX_HB_CHALLENGE_RESP_EVENT ;used (reply to 2008h)
Event Data:

      00h  A_UINT32  4    cookie;   ;\same reply-format as command parameters
      04h  A_UINT32  4    source;   ;/

Actually, there are TWO or THREE more 32bit words appended on DSi... in relation to flags in MBOX0[04h], or actually MBOX0[04h] is the LENGTH in bytes of that extra stuff?!?!!
WMIevent(1011h) - WMI_CAC_EVENT
Supposedly related to Call Admission Control (CAC), eg. for VoIP.
Event Data (42h bytes):

      00h  A_UINT8  1    ac;
      01h  A_UINT8  1    cac_indication;
      02h  A_UINT8  1    statusCode;
      03h  A_UINT8  3Fh  tspecSuggestion[WMM_TSPEC_IE_LEN];

CAC_INDICATION values:

      CAC_INDICATION_ADMISSION      = 00h
      CAC_INDICATION_ADMISSION_RESP = 01h
      CAC_INDICATION_DELETE         = 02h
      CAC_INDICATION_NO_RESP        = 03h

#define WMM_TSPEC_IE_LEN = 63
WMIevent(1017h) - WMI_APLIST_EVENT
Event Data:

      00h  A_UINT8      1    apListVer;
      01h  A_UINT8      1    numAP;
      02h  WMI_AP_INFO  N*8  apList[1];

APLIST_VER values (only one defined):

        APLIST_VER1 = 1,

WMI_AP_INFO structure:

      typedef PREPACK union {
        WMI_AP_INFO_V1  8   apInfoV1;
      } POSTPACK WMI_AP_INFO;

WMI_AP_INFO_V1 structure:

        A_UINT8  6   bssid[ATH_MAC_LEN];
        A_UINT16 2   channel;

WMIevent(1019h) - WMI_GET_PMKID_LIST_EVENT ;reply to CMD F006h
See WMI_GET_PMKID_LIST_CMD for response details.

DSi Atheros Wifi - WMI Connect Functions

WMIcmd(0001h) - WMI_CONNECT_CMD
Parameters (34h bytes):

      00h  A_UINT8  1   networkType          ;somewhat NETWORK_TYPE related ?   (1)
      01h  A_UINT8  1   dot11AuthMode        ;aka DOT11_AUTH_MODE ? (1=Open, 2=WEP)
      02h  A_UINT8  1   authMode             ;aka AUTH_MODE ?                   (1)
      03h  A_UINT8  1   pairwiseCryptoType   ;aka CRYPTO_TYPE       (1=Open, 2=WEP)
      04h  A_UINT8  1   pairwiseCryptoLen                                       (0)
      05h  A_UINT8  1   groupCryptoType      ;aka CRYPTO_TYPE       (1=Open, 2=WEP)
      06h  A_UINT8  1   groupCryptoLen                                          (0)
      07h  A_UINT8  1   ssidLength
      08h  A_UCHAR  32  ssid[WMI_MAX_SSID_LEN]
      28h  A_UINT16 2   channel              ;in MHz
      2Ah  A_UINT8  6   bssid[ATH_MAC_LEN]
      30h  A_UINT32 4   ctrl_flags                                              (0)

Returns WMI_CONNECT_EVENT (or WMI_DISCONNECT_EVENT, eg. upon bad WEP password).
NETWORK_TYPE values:

      INFRA_NETWORK       = 01h      ;DSi uses 01h for Open/WEP/WPA/WPA2
      ADHOC_NETWORK       = 02h
      ADHOC_CREATOR       = 04h
      AP_NETWORK          = 10h

NETWORK_SUBTYPE values (unknown purpose, and unknown if they start at 0 or 1 or so):

      SUBTYPE_NONE        = unknown (maybe 0 or 1 or so?)
      SUBTYPE_BT          = SUBTYPE_NONE+1
      SUBTYPE_P2PDEV      = SUBTYPE_NONE+2
      SUBTYPE_P2PCLIENT   = SUBTYPE_NONE+3
      SUBTYPE_P2PGO       = SUBTYPE_NONE+4

DOT11_AUTH_MODE values:

      OPEN_AUTH           = 01h      ;DSi uses 01h for Open/WPA/WPA2
      SHARED_AUTH         = 02h      ;DSi uses 02h for WEP
      LEAP_AUTH           = 04h  /* different from IEEE_AUTH_MODE definitions

AUTH_MODE values:

      WMI_NONE_AUTH       = 01h      ;DSi uses 01h for Open/WEP
      WMI_WPA_AUTH        = 02h  ;\whatever maybe for RADIUS?
      WMI_WPA2_AUTH       = 04h  ;/
      WMI_WPA_PSK_AUTH    = 08h      ;DSi uses 03h (not 08h) for WPA-PSK
      WMI_WPA2_PSK_AUTH   = 10h      ;DSi uses 05h (not 10h) for WPA2-PSK
      WMI_WPA_AUTH_CCKM   = 20h  ;\whatever for "Cisco Centralized Key Management"?
      WMI_WPA2_AUTH_CCKM  = 40h  ;/

CRYPTO_TYPE values:

      NONE_CRYPT          = 01h      ;DSi uses 01h for Open
      WEP_CRYPT           = 02h      ;DSi uses 02h for WEP
      TKIP_CRYPT          = 04h      ;DSi uses 03h (not 04h) for WPA
      AES_CRYPT           = 08h      ;DSi uses 04h (not 08h) for WPA2
      WAPI_CRYPT          = 10h  ;only if WAPI_ENABLE

connect "ctrl_flags":

      0   CONNECT_ASSOC_POLICY_USER           = 0001h
      1   CONNECT_SEND_REASSOC                = 0002h
      2   CONNECT_IGNORE_WPAx_GROUP_CIPHER    = 0004h
      3   CONNECT_PROFILE_MATCH_DONE          = 0008h
      4   CONNECT_IGNORE_AAC_BEACON           = 0010h
      5   CONNECT_CSA_FOLLOW_BSS              = 0020h
      6   CONNECT_PYXIS_REMOTE                = 0040h  ;-old code from 2008
      6   CONNECT_DO_WPA_OFFLOAD              = 0040h  ;\
      7   CONNECT_DO_NOT_DEAUTH               = 0080h  ; new code from 2010
      8   CONNECT_WPS_FLAG                    = 0100h  ;
      9   CONNECT_IGNORE_BSSID_HINT           = 0200h  ;
      16  AP_NO_DISASSOC_UPON_DEAUTH          = 10000h ;/ <--AP configuration flags

DEFAULT_CONNECT_CTRL_FLAGS = (CONNECT_CSA_FOLLOW_BSS)
WMIcmd(0002h) - WMI_RECONNECT_CMD
Parameters (optional...?... 08h bytes):

      00h  A_UINT16 2   channel                     ;hint
      02h  A_UINT8  6   bssid[ATH_MAC_LEN]          ;mandatory if set

WMIcmd(0003h) - WMI_DISCONNECT_CMD
Parameters:

      Unknown (none?)

Returns WMI_DISCONNECT_EVENT. Uhm, or seems to crash on AR6013...?
WMIcmd(000Dh) - WMI_SET_DISC_TIMEOUT_CMD ;aka WMI_SET_DISCONNECT_TIMEOUT
Parameters (01h bytes):

      00h  A_UINT8  1   disconnectTimeout           ;seconds

WMIevent(1002h) - WMI_CONNECT_EVENT
First 10h bytes of response can be "infra_ibss_bss" or "ap_sta" or "ap_bss" (unclear which selects/indicates which it is, maybe the parameters from preceeding WMI_CONNECT_CMD, or from WMI_BSSINFO_EVENT's frame body?)
Also unknown what is sent in case of connect ERROR (maybe DISCONNECT_EVENT?)
Event Data:

     When "infra_ibss_bss":                      ;<-- occurs for my WPA2 connect
      00h  A_UINT16 2   channel                     ;in MHz
      02h  A_UINT8  6   bssid[ATH_MAC_LEN]          ;
      08h  A_UINT16 2   listenInterval              ;0064h
      0Ah  A_UINT16 2   beaconInterval              ;0064h
      0Ch  A_UINT32 4   networkType                 ;00000001h
     When "ap_sta":
      00h  A_UINT8  1   phymode
      01h  A_UINT8  1   aid
      02h  A_UINT8  6   mac_addr[ATH_MAC_LEN]
      08h  A_UINT8  1   auth
      09h  A_UINT8  1   keymgmt
      0Ah  A_UINT16 2   cipher
      0Ch  A_UINT8  1   apsd_info
      0Dh  A_UINT8  3   unused[3]
     When "ap_bss":
      00h  A_UINT16 2   channel
      02h  A_UINT8  6   bssid[ATH_MAC_LEN]
      08h  A_UINT8  8   unused[8]
     And, in all three cases:
      10h  A_UINT8  1   beaconIeLen                 ;16h
      11h  A_UINT8  1   assocReqLen                 ;2Fh
      12h  A_UINT8  1   assocRespLen                ;16h
      13h  A_UINT8  ..  assocInfo[1]                ;whatever 100 bytes?

In STA mode networkType comes along with connected phy mode.
To get networkType, WMI_NETWORK_TYPE (networkType).
To get connected phymode, WMI_CONNECTED_PHYMODE(networkType) will give the phymode value.
WMIevent(1003h) - WMI_DISCONNECT_EVENT
This event can occur when using WMI_CONNECT with wrong WEP password (instead of WMI_CONNECT_EVENT), or when failing to respond to WPA/WPA2 handshake messages, or when using WMI_DISCONNECT.
Event Data (0Ah+N bytes):

      00h  A_UINT16 2    protocolReasonStatus ;reason code, see 802.11 spec.
      02h  A_UINT8  6    bssid[ATH_MAC_LEN]   ;set if known
      08h  A_UINT8  1    disconnectReason     ;see WMI_DISCONNECT_REASON
      09h  A_UINT8  1    assocRespLen (00h=none)
      0Ah  A_UINT8  N*1  assocInfo[1]

WMI_DISCONNECT_REASON values:

      NO_NETWORK_AVAIL      = 01h  ;-occurs on wrong WEP key
      LOST_LINK             = 02h  ;-bmiss
      DISCONNECT_CMD        = 03h  ;-requested via disconnect command
      BSS_DISCONNECTED      = 04h  ;-occurs after some minutes of inactivity?
      AUTH_FAILED           = 05h  ;-reportedly occurs if AP was already connected?
      ASSOC_FAILED          = 06h
      NO_RESOURCES_AVAIL    = 07h
      CSERV_DISCONNECT      = 08h
      INVALID_PROFILE       = 0Ah
      DOT11H_CHANNEL_SWITCH = 0Bh
      PROFILE_MISMATCH      = 0Ch
      PYXIS_VIRT_ADHOC_DISC = 0Dh  ;-old code from 2008
      CONNECTION_EVICTED    = 0Dh  ;\
      IBSS_MERGE            = 0Eh  ; new code from 2010
      EXCESS_TX_RETRY       = 0Fh  ;/  <--TX frames failed after excessive retries

DSi Atheros Wifi - WMI Channel and Cipher Functions

WMIcmd(000Eh) - WMI_GET_CHANNEL_LIST_CMD ;reply 000Eh ;aka WMI_CHANNEL_LIST
Parameters:

      None

WMI_GET_CHANNEL_LIST_CMD reply ;aka WMI_CHANNEL_LIST_REPLY

      00h  A_UINT8  1    reserved1          ;whatever (zero)
      01h  A_UINT8  1    numChannels        ;number of channels in reply (N)
      02h  A_UINT16 N*2  channelList[1]     ;channels in MHz
      02h+N*2       2    Zero (0000h)       ;undocumented (end of list or so)

Reply size is 1Ah bytes on DSi (2+(11*2)+2 bytes, for 11 channels, plus ending 0000h; that ending halfward isn't officially mentioned to exist).
WMIcmd(0011h) - WMI_SET_CHANNEL_PARAMS_CMD ;aka WMI_CHANNEL_PARAMS_CMD
Parameters (04h+N*2 bytes):

      00h  A_UINT8  1   reserved1           ;whatever (?)
      01h  A_UINT8  1   scanParam           ;set if enable scan
      02h  A_UINT8  1   phyMode             ;see WMI_PHY_MODE
      03h  A_UINT8  1   numChannels         ;how many channels follow
      04h  A_UINT16 N*2 channelList[1]      ;channels in MHz

WMI_PHY_MODE values:

      WMI_11A_MODE     = 01h
      WMI_11G_MODE     = 02h
      WMI_11AG_MODE    = 03h
      WMI_11B_MODE     = 04h
      WMI_11GONLY_MODE = 05h

#define WMI_MAX_CHANNELS = 32
Some (or all?) DSi's have only channel 1-11 enabled, and throw WMI_CMDERROR_EVENT when trying to set channel 12,13,14. Unknown what defines which channels are enabled (probably something in EEPROM).
The enabled channels can be obtained via WMI_GET_CHANNEL_LIST_CMD (which is probably related to the country reported in WMI_REGDOMAIN_EVENT).
WMIevent(101Ah) - WMI_CHANNEL_CHANGE_EVENT ;<-- used on DSi ?
Event Data (06h bytes):

      00h  A_UINT16  2  oldChannel;   ;\uh, old is 16bit, new is misaligned 32bit?
      02h  A_UINT32  4  newChannel;   ;/(DSi does really send 6 bytes)

This event is not defined in "AR6kSDK.build_sw.18", however, "101Ah" is USED on DSi.
WMIcmd(0016h) - WMI_ADD_CIPHER_KEY_CMD
Parameters (2Dh bytes on DSi?, but other sources claim 2Ch or 33h bytes):

      2Ch 2Dh 33h   <---- total size (on DSi it's 2Dh, ie. middle column)
      00h 00h 00h  A_UINT8  1   keyIndex ;aka WMI_MAX_KEY_INDEX ?
      01h 01h 01h  A_UINT8  1   keyType  ;aka CRYPTO_TYPE
      02h 02h 02h  A_UINT8  1   keyUsage      ;KEY_USAGE
      03h 03h 03h  A_UINT8  1   keyLength
      04h 04h 04h  A_UINT8  8   keyRSC[8]     ;key replay sequence counter
      0Ch 0Ch 0Ch  A_UINT8  32  key[WMI_MAX_KEY_LEN]    ;aka password
      --  2Ch 2Ch  A_UINT8  1   key_op_ctrl   ;Additional Key Control information
      --  --  2Dh  A_UINT8  6   key_macaddr[ATH_MAC_LEN]

KEY_USAGE values:

      PAIRWISE_USAGE     = 00h ;<-- DSi browser uses THIS for WPA/WPA2 key 0
      GROUP_USAGE        = 01h ;<-- DSi browser uses THIS for WEP/WPA/WPA2 key 1..3
      TX_USAGE           = 02h ;<-- reportedly "default Tx Key - Static WEP only"
      Undoc (or 01h+02h) = 03h ;<-- DSi browser uses THIS for WEP key 0

Bit Flag. (aka key_op_ctrl values?):

      Bit 0 - Initialise TSC - default is Initialize
      KEY_OP_INIT_TSC    = 01h
      KEY_OP_INIT_RSC    = 02h
      KEY_OP_INIT_WAPIPN = 10h (only if "WAPI_ENABLE")
      KEY_OP_INIT_VAL    = 03h  ;<-- Default Initialise the TSC & RSC ;used by DSi
      KEY_OP_VALID_MASK  = 03h

More constants:

      WMI_MIN_KEY_INDEX = 0
      WMI_MAX_KEY_INDEX = 3  ;<-- when not "WAPI_ENABLE"
      WMI_MAX_KEY_INDEX = 7  ;<-- when "WAPI_ENABLE" (wapi grpKey 0-3, prwKey 4-7)
      WMI_MAX_KEY_LEN   = 32

WEP Cipher Keys
All four keys (with KeyIndex=0..3) must be set before WMI_CONNECT_CMD. The NDS/DSi user interface allows to define only one WEP key 0, but one must add dummy keys for key 1..3, else connect will fail.
WPA/WPA2 Cipher Keys
For WPA/WPA2, WMI_CONNECT_CMD isn't working fully automated: After WMI_CONNECT_EVENT, one must manually receive & reply EAPOL handshake messages, and then add the cipher keys based on the message contents. The used keys are key 0 (for pairwise cipher), and key 1 or 2 (for the current group cipher key).
DS Wifi WPA/WPA2 Handshake Messages (EAPOL)
DS Wifi WPA/WPA2 Keys and MICs
DS Wifi WPA/WPA2 Encryption
DS Firmware Wifi Calibration Data
DS Firmware Wifi Internet Access Points
Moreover, the access point may throw further EAPOL messages for assigning new group keys every once and then, and one must also manually apply that new key via ADD_CIPHER (the group key index switches between 1 and 2 on each update).

      KeyIndex=0,   key=PTK[20h..2Fh]+PTK[38h..3Fh]+PTK[30h..37h], RSC=0
      KeyIndex=1/2, key=GTK[00h..0Fh]+PTK[18h..1Fh]+PTK[10h..17h], RSC=EAPOL RSC

WAPI Cipher Keys
Some atheros firmwares have "WAPI_ENABLE" with eight key indices (grpKey=0..3, prwKey=4..7). The DSi firmware probably doesn't have that WAPI stuff.
WMIcmd(0017h) - WMI_DELETE_CIPHER_KEY_CMD ;ignored dummy command on DSi
Parameters (01h bytes):

      00h  A_UINT8  1   keyIndex

WMIcmd(0018h) - WMI_ADD_KRK_CMD ;ignored dummy command on DSi
Parameters (10h bytes):

      00h  A_UINT8  16  krk[WMI_KRK_LEN]

#define WMI_KRK_LEN = 16
KRK maybe means "Key Registration with Knowledge"?
WMIcmd(0019h) - WMI_DELETE_KRK_CMD ;ignored dummy command on DSi
Parameters:

      Unknown (none?) (or maybe same as for ADD_KRK ?) (seems to be NONE on DSi)

WMIcmd(0020h) - WMI_SET_TKIP_COUNTERMEASURES_CMD
Parameters (01h bytes):

      00h  A_UINT8  1  cm_en                      ;WMI_TKIP_CM_CONTROL

WMI_TKIP_CM_CONTROL values:

      WMI_TKIP_CM_DISABLE = 00h
      WMI_TKIP_CM_ENABLE  = 01h

Note: There are also "CM_CONNECT_TYPE" values in "cnxmgmt.h", is THAT related?
WMIevent(1009h) - WMI_TKIP_MICERR_EVENT
Event Data (02h bytes):

      00h  A_UINT8  1  keyid
      01h  A_UINT8  1  ismcast

TKIP MIC Error Event

DSi Atheros Wifi - WMI Scan Functions

WMIcmd(0007h) - WMI_START_SCAN_CMD
Parameters (theoretically 12h+N*2 bytes, but 14h bytes when N=0 ?):

      00h  A_BOOL   4   forceFgScan
      04h  A_BOOL   4   isLegacy            For Legacy Cisco AP compatibility
      08h  A_UINT32 4   homeDwellTime       Max duration in the home channel (msec)
      0Ch  A_UINT32 4   forceScanInterval   Time interval between scans (msec)
      10h  A_UINT8  1   scanType            WMI_SCAN_TYPE
      11h  A_UINT8  1   numChannels         how many channels follow
      12h  A_UINT16 N*2 channelList[1]      channels in MHz

WMI_SCAN_TYPE values:

      WMI_LONG_SCAN  = 0
      WMI_SHORT_SCAN = 1

Old code from 2008 did (additionally) use value 0 and 1 as so:

      WMI_PYXIS_PAS_DSCVR = 0
      WMI_PYXIS_ACT_DSCVR = 1

The DSi Browser receives one or more WMI_BSSINFO_EVENT's (if there are any beacons on the current channel), and, once when the DwellTime (mul5?) has ellapsed, finally receives WMI_SCAN_COMPLETE_EVENT.
WMIcmd(0008h) - WMI_SET_SCAN_PARAMS_CMD
Parameters (14h bytes):

      00h  A_UINT16 2  fg_start_period         ;seconds
      02h  A_UINT16 2  fg_end_period           ;seconds
      04h  A_UINT16 2  bg_period               ;seconds
      06h  A_UINT16 2  maxact_chdwell_time     ;msec
      08h  A_UINT16 2  pas_chdwell_time        ;msec
      0Ah  A_UINT8  1  shortScanRatio          ;how many shorts scan for one long
      0Bh  A_UINT8  1  scanCtrlFlags
      0Ch  A_UINT16 2  minact_chdwell_time     ;msec
      0Eh  A_UINT16 2  maxact_scan_per_ssid    ;max active scans per ssid
      10h  A_UINT32 4  max_dfsch_act_time      ;msec

#define WMI_SHORTSCANRATIO_DEFAULT = 3
Warning: ScanCtrlFlag value of FFh is used to disable all flags in WMI_SCAN_PARAMS_CMD
Do not add any more flags to WMI_SCAN_CTRL_FLAG_BITS
WMI_SCAN_CTRL_FLAGS_BITS:

      CONNECT_SCAN_CTRL_FLAGS   = 01h  ;set if can scan in the Connect cmd
      SCAN_CONNECTED_CTRL_FLAGS = 02h  ;set if scan for the SSID it is
                                       ;  already connected to
      ACTIVE_SCAN_CTRL_FLAGS    = 04h  ;set if enable active scan
      ROAM_SCAN_CTRL_FLAGS      = 08h  ;set if enable roam scan when bmiss
                                       ;  and lowrssi
      REPORT_BSSINFO_CTRL_FLAGS = 10h  ;set if follows customer BSSINFO
                                       ;  reporting rule
      ENABLE_AUTO_CTRL_FLAGS    = 20h  ;if disabled, target doesn't
                                       ;  scan after a disconnect event
      ENABLE_SCAN_ABORT_EVENT   = 40h  ;Scan complete event with canceled status
                                       ;  will be generated when a scan is
                                       ;  prempted before it gets completed
     #define CAN_SCAN_IN_CONNECT(flags)      (flags & CONNECT_SCAN_CTRL_FLAGS)
     #define CAN_SCAN_CONNECTED(flags)       (flags & SCAN_CONNECTED_CTRL_FLAGS)
     #define ENABLE_ACTIVE_SCAN(flags)       (flags & ACTIVE_SCAN_CTRL_FLAGS)
     #define ENABLE_ROAM_SCAN(flags)         (flags & ROAM_SCAN_CTRL_FLAGS)
     #define CONFIG_REPORT_BSSINFO(flags)    (flags & REPORT_BSSINFO_CTRL_FLAGS)
     #define IS_AUTO_SCAN_ENABLED(flags)     (flags & ENABLE_AUTO_CTRL_FLAGS)
     #define SCAN_ABORT_EVENT_ENABLED(flags) (flags & ENABLE_SCAN_ABORT_EVENT)

#define DEFAULT_SCAN_CTRL_FLAGS = (CONNECT_SCAN_CTRL_FLAGS | SCAN_CONNECTED_CTRL_FLAGS | ACTIVE_SCAN_CTRL_FLAGS | ROAM_SCAN_CTRL_FLAGS | ENABLE_AUTO_CTRL_FLAGS)
WMIevent(100Ah) - WMI_SCAN_COMPLETE_EVENT
Event Data (old: None, or new: status, 04h bytes):

      00h  A_INT32  4  status;    ;aka "staus"

(whatever, usually/always zero)
(can be 10h... when already connected maybe?)
Note: There are several "SCAN_xxx" and "xxx_SCPRI" values defined in "discovery.h" - purpose is unknown (maybe that stuff is used only internally).

DSi Atheros Wifi - WMI Bit Rate Functions

WMIcmd(0034h) - WMI_SET_FIXRATES_CMD ;aka WMI_FIX_RATES_CMD
Parameters (02h bytes on DSi?, but other sources claim 08h bytes):

      02h 08h   <---- total size (on DSi it's 02h, ie. left column)
      00h --  A_UINT16 2   fixRateMask     ;0..0FFFh          ;see WMI_BIT_RATE
      --  00h A_UINT32 4   fixRateMask(0)  ;0..0FFFFFFFh      ;see WMI_BIT_RATE
      --  04h A_UINT32 4   fixRateMask(1)  ;0..0FFFFFFFh      ;see WMI_BIT_RATE

WMIcmd(0035h) - WMI_GET_FIXRATES_CMD ;reply 0035h
Parameters:

      Unknown (none?)

Reply: WMI_GET_FIXRATES aka WMI_FIX_RATES_REPLY
Event Data (02h bytes on DSi?, but other sources claim 08h bytes):

      02h 08h   <---- total size (on DSi it's 02h, ie. left column)
      00h --  A_UINT16 2   fixRateMask     ;0..0FFFh           ;see WMI_BIT_RATE
      --  00h A_UINT32 4   fixRateMask(0)  ;0..0FFFFFFFh       ;see WMI_BIT_RATE
      --  04h A_UINT32 4   fixRateMask(1)  ;0..0FFFFFFFh       ;see WMI_BIT_RATE

See "FIX_RATE_xxx" values.
WMIcmd(0048h or 0047h) - WMI_SET_FRAMERATES_CMD ;aka WMI_FRAME_RATES_CMD
DSi uses command number 0048h for this (whilst most or all official Atheros code is using number 0047h).
Parameters (04h bytes, or 0Ch bytes on hardware with more rates):

      04h 0Ch   <---- total size (on DSi it's 04h, ie. left column)
      00h 00h  A_UINT8  1   bEnableMask               (used: 01h) ;whatever?
      01h 01h  A_UINT8  1   frameType  (D4h=special?) (used: A4h) ;type and subtype
      02h --   A_UINT16 2   frameRateMask ;0..0FFFh (used: FFF7h) ;see WMI_BIT_RATE
      --  02h  A_UINT8  2   reserved[2]                           ;for alignment
      --  04h  A_UINT32 4   frameRateMask(0)  ;0..0FFFFFFFh       ;see WMI_BIT_RATE
      --  08h  A_UINT32 4   frameRateMask(1)  ;0..0FFFFFFFh       ;see WMI_BIT_RATE

Note: FRAMERATE is apparently meant to be "bitrate" for certain "packet types" (frames). The type and subtype values are maybe meant to resemble those in Frame Control (FC) field, or the FTYPE_xxx constants in some atheros source code?
Reportedly there is a "WMI_FRAME_RATES_REPLY" with same Reply structure as above Parameter structure, the DSi doesn't support that feature (and it's rather unknown if/when/how that Reply would be sent if the feature were implemented... maybe as event, or as reply to SET_FRAMERATES, or as reply to whatever other cmd).
WMIcmd(F000h) - WMI_SET_BITRATE_CMD ;aka WMI_BIT_RATE_CMD
Parameters (03h bytes):

      00h  A_INT8  1   rateIndex      (FFh=Auto)     ;see WMI_BIT_RATE
      01h  A_INT8  1   mgmtRateIndex  (00h=1Mbit/s)
      02h  A_INT8  1   ctlRateIndex   (00h=1Mbit/s)

Note: This doesn't really work. Using rateIndex=FFh (or 0Bh) does currently reach only max 600Kbyte/s upload speed (which MIGHT be a bug in my software). However, using rateIndex=00h is slower, but still reaches more than 200Kbyte/s (which is outright wrong and impossible at 1Mbit/s).
WMIcmd(F001h) - WMI_GET_BITRATE_CMD ;reply F001h
Parameters:

      Unknown (none?)

Reply:

      00h  A_INT8   1    rateIndex           ;see WMI_BIT_RATE

WMI_BIT_RATE values

      Mbit/s        = Index      Mbit/s            = Mask
      RATE_AUTO     = -1         -                 = -
      RATE_1Mb      = 0          FIX_RATE_1Mb      = 1h
      RATE_2Mb      = 1          FIX_RATE_2Mb      = 2h
      RATE_5_5Mb    = 2          FIX_RATE_5_5Mb    = 4h
      RATE_11Mb     = 3          FIX_RATE_11Mb     = 8h
      RATE_6Mb      = 4          FIX_RATE_6Mb      = 10h
      RATE_9Mb      = 5          FIX_RATE_9Mb      = 20h
      RATE_12Mb     = 6          FIX_RATE_12Mb     = 40h
      RATE_18Mb     = 7          FIX_RATE_18Mb     = 80h
      RATE_24Mb     = 8          FIX_RATE_24Mb     = 100h
      RATE_36Mb     = 9          FIX_RATE_36Mb     = 200h
      RATE_48Mb     = 10         FIX_RATE_48Mb     = 400h
      RATE_54Mb     = 11         FIX_RATE_54Mb     = 800h

Below only for newer (non-DSi) revisions (with 32bit RATE_MASK values):

      RATE_MCS_0_20 = 12         FIX_RATE_MCS_0_20 = 1000h
      RATE_MCS_1_20 = 13         FIX_RATE_MCS_1_20 = 2000h
      RATE_MCS_2_20 = 14         FIX_RATE_MCS_2_20 = 4000h
      RATE_MCS_3_20 = 15         FIX_RATE_MCS_3_20 = 8000h
      RATE_MCS_4_20 = 16         FIX_RATE_MCS_4_20 = 10000h
      RATE_MCS_5_20 = 17         FIX_RATE_MCS_5_20 = 20000h
      RATE_MCS_6_20 = 18         FIX_RATE_MCS_6_20 = 40000h
      RATE_MCS_7_20 = 19         FIX_RATE_MCS_7_20 = 80000h
      RATE_MCS_0_40 = 20         FIX_RATE_MCS_0_40 = 100000h
      RATE_MCS_1_40 = 21         FIX_RATE_MCS_1_40 = 200000h
      RATE_MCS_2_40 = 22         FIX_RATE_MCS_2_40 = 400000h
      RATE_MCS_3_40 = 23         FIX_RATE_MCS_3_40 = 800000h
      RATE_MCS_4_40 = 24         FIX_RATE_MCS_4_40 = 1000000h
      RATE_MCS_5_40 = 25         FIX_RATE_MCS_5_40 = 2000000h
      RATE_MCS_6_40 = 26         FIX_RATE_MCS_6_40 = 4000000h
      RATE_MCS_7_40 = 27         FIX_RATE_MCS_7_40 = 8000000h

Get bit rate cmd uses same definition as set bit rate cmd

DSi Atheros Wifi - WMI Threshold Functions

Below commands allow to define thresholds for RSSI, SNR, LQ.

      RSSI  Received Signal Strength Indicator
      SNR   Signal to Noise Ratio
      LQ    Link Quality

WMIcmd(0021h) - WMI_RSSI_THRESHOLD_PARAMS_CMD
Parameters (20h bytes):

      00h  A_UINT32 4  pollTime                ;Polling time as a factor of LI
      04h  A_INT16  2  thresholdAbove1_Val     ;lowest of upper
      06h  A_INT16  2  thresholdAbove2_Val
      08h  A_INT16  2  thresholdAbove3_Val
      0Ah  A_INT16  2  thresholdAbove4_Val
      0Ch  A_INT16  2  thresholdAbove5_Val
      0Eh  A_INT16  2  thresholdAbove6_Val     ;highest of upper
      10h  A_INT16  2  thresholdBelow1_Val     ;lowest of bellow
      12h  A_INT16  2  thresholdBelow2_Val
      14h  A_INT16  2  thresholdBelow3_Val
      16h  A_INT16  2  thresholdBelow4_Val
      18h  A_INT16  2  thresholdBelow5_Val
      1Ah  A_INT16  2  thresholdBelow6_Val     ;highest of bellow
      1Ch  A_UINT8  1  weight                  ;"alpha"
      1Dh  A_UINT8  3  reserved[3]
     Setting the polltime to 0 would disable polling.
     Threshold values are in the ascending order, and should agree to:
       (lowThreshold_lowerVal < lowThreshold_upperVal < highThreshold_lowerVal
         < highThreshold_upperVal)

See also: WMI_RSSI_THRESHOLD_EVENT
WMIcmd(002Fh) - WMI_SNR_THRESHOLD_PARAMS_CMD
Parameters (10h bytes):

      00h  A_UINT32 4  pollTime                ;Polling time as a factor of LI
      04h  A_UINT8  1  weight                  ;"alpha"
      05h  A_UINT8  1  thresholdAbove1_Val     ;lowest of uppper   ;uh, ppper?
      06h  A_UINT8  1  thresholdAbove2_Val
      07h  A_UINT8  1  thresholdAbove3_Val
      08h  A_UINT8  1  thresholdAbove4_Val     ;highest of upper
      09h  A_UINT8  1  thresholdBelow1_Val     ;lowest of bellow   ;uh bell?
      0Ah  A_UINT8  1  thresholdBelow2_Val
      0Bh  A_UINT8  1  thresholdBelow3_Val
      0Ch  A_UINT8  1  thresholdBelow4_Val     ;highest of bellow  ;uh bell?
      0Dh  A_UINT8  3  reserved[3]

Setting the polltime to 0 would disable polling.
See also: WMI_SNR_THRESHOLD_EVENT
WMIcmd(0030h) - WMI_LQ_THRESHOLD_PARAMS_CMD
Parameters (0Ch bytes):

      00h  A_UINT8  1  enable              ;<-- enable (unlike SNR command)
      01h  A_UINT8  1  thresholdAbove1_Val   ;\these parameters seem to be same as
      02h  A_UINT8  1  thresholdAbove2_Val   ; for WMI_SNR_THRESHOLD_PARAMS_CMD
      03h  A_UINT8  1  thresholdAbove3_Val   ;
      04h  A_UINT8  1  thresholdAbove4_Val   ;
      05h  A_UINT8  1  thresholdBelow1_Val   ;
      06h  A_UINT8  1  thresholdBelow2_Val   ;
      07h  A_UINT8  1  thresholdBelow3_Val   ;
      08h  A_UINT8  1  thresholdBelow4_Val   ;
      09h  A_UINT8  3  reserved[3]           ;/

See also: WMI_LQ_THRESHOLD_EVENT
WMIcmd(0033h) - WMI_CLR_RSSI_SNR_CMD
Parameters:

      Unknown (none?)

Probably somehow related to RSSI_THRESHOLD and SNR_THRESHOLD.
WMIevent(100Ch) - WMI_RSSI_THRESHOLD_EVENT
Event Data (03h bytes):

      00h  A_INT16  2   rssi;
      02h  A_UINT8  1   range;

WMI_RSSI_THRESHOLD_VAL values (which are probably meant to occurr in one of above fields, unclear which one though):

      WMI_RSSI_THRESHOLD1_ABOVE = 0
      WMI_RSSI_THRESHOLD2_ABOVE = 1
      WMI_RSSI_THRESHOLD3_ABOVE = 2
      WMI_RSSI_THRESHOLD4_ABOVE = 3
      WMI_RSSI_THRESHOLD5_ABOVE = 4
      WMI_RSSI_THRESHOLD6_ABOVE = 5
      WMI_RSSI_THRESHOLD1_BELOW = 6
      WMI_RSSI_THRESHOLD2_BELOW = 7
      WMI_RSSI_THRESHOLD3_BELOW = 8
      WMI_RSSI_THRESHOLD4_BELOW = 9
      WMI_RSSI_THRESHOLD5_BELOW = 10
      WMI_RSSI_THRESHOLD6_BELOW = 11

Indicate the RSSI events to host. Events are indicated when we breach a thresold value. (uh, how old do we breach?)
WMIevent(1012h) - WMI_SNR_THRESHOLD_EVENT
Event Data (02h bytes):

      00h  A_UINT8  1  range        ;WMI_SNR_THRESHOLD_VAL
      01h  A_UINT8  1  snr

WMI_SNR_THRESHOLD_VAL values:

      WMI_SNR_THRESHOLD1_ABOVE = 1
      WMI_SNR_THRESHOLD1_BELOW = 2
      WMI_SNR_THRESHOLD2_ABOVE = 3
      WMI_SNR_THRESHOLD2_BELOW = 4
      WMI_SNR_THRESHOLD3_ABOVE = 5
      WMI_SNR_THRESHOLD3_BELOW = 6
      WMI_SNR_THRESHOLD4_ABOVE = 7
      WMI_SNR_THRESHOLD4_BELOW = 8

WMIevent(1013h) - WMI_LQ_THRESHOLD_EVENT
Event Data (05h bytes):

      00h  A_INT32  4  lq
      04h  A_UINT8  1  range        ;WMI_LQ_THRESHOLD_VAL

WMI_LQ_THRESHOLD_VAL values:

      WMI_LQ_THRESHOLD1_ABOVE = 1
      WMI_LQ_THRESHOLD1_BELOW = 2
      WMI_LQ_THRESHOLD2_ABOVE = 3
      WMI_LQ_THRESHOLD2_BELOW = 4
      WMI_LQ_THRESHOLD3_ABOVE = 5
      WMI_LQ_THRESHOLD3_BELOW = 6
      WMI_LQ_THRESHOLD4_ABOVE = 7
      WMI_LQ_THRESHOLD4_BELOW = 8

DSi Atheros Wifi - WMI Error, Retry and Debug Functions

WMIcmd(0024h) - WMI_SET_RETRY_LIMITS_CMD
Parameters:

      00h  A_UINT8  1  frameType          ;WMI_FRAMETYPE
      01h  A_UINT8  1  trafficClass       ;applies only to DATA_FRAMETYPE
      02h  A_UINT8  1  maxRetries
      03h  A_UINT8  1  enableNotify

This command is used to customize the number of retries the wlan device will perform on a given frame.

      WMI_MIN_RETRIES = 2
      WMI_MAX_RETRIES = 13

WMI_FRAMETYPE values:

      MGMT_FRAMETYPE    = 0
      CONTROL_FRAMETYPE = 1
      DATA_FRAMETYPE    = 2

WMIcmd(0022h) - WMI_TARGET_ERROR_REPORT_BITMASK_CMD
Parameters (04h bytes):

      00h  A_UINT32 4   bitmask    ;... probably "WMI_TARGET_ERROR_VAL" ?

Sets the error reporting event bitmask in target. Target clears it upon an error. Subsequent errors are counted, but not reported via event, unless the bitmask is set again.
See also: WMI_TARGET_ERROR_REPORT_EVENT
WMIevent(1005h) - WMI_CMDERROR_EVENT ;aka WMI_CMD_ERROR_EVENT
Event Data (03h bytes):

      00h  A_UINT16 2   commandId    ;on DSi, this can be: 0001h,0011h,0016h,0026h
      02h  A_UINT8  1   errorCode    ;on DSi, this can be: 01h,02h

WMI_ERROR_CODE values:

      INVALID_PARAM  = 01h
      ILLEGAL_STATE  = 02h
      INTERNAL_ERROR = 03h
      DFS_CHANNEL    = 04h

Command Error Event
WMIevent(100Dh) - WMI_ERROR_REPORT_EVENT ;aka WMI_TARGET_ERROR_REPORT_EVENT
Event Data (04h bytes):

      00h  A_UINT32  4  errorVal

WMI_TARGET_ERROR_VAL values:

      WMI_TARGET_PM_ERR_FAIL      = 00000001h
      WMI_TARGET_KEY_NOT_FOUND    = 00000002h
      WMI_TARGET_DECRYPTION_ERR   = 00000004h
      WMI_TARGET_BMISS            = 00000008h
      WMI_PSDISABLE_NODE_JOIN     = 00000010h
      WMI_TARGET_COM_ERR          = 00000020h
      WMI_TARGET_FATAL_ERR        = 00000040h
      WMI_TARGET_BCN_FOUND        = 00000080h

WMIevent(1014h) - WMI_TX_RETRY_ERR_EVENT
Event Data (01h bytes):

      00h  A_UINT8  1   retrys

WMIcmd(002Eh:2009h) - WMIX_DBGLOG_CFG_MODULE_CMD
Parameters (said to be as so):

      00h  A_UINT32 4   cfgvalid        ;mask with valid config bits (uh, what?)
     When some case:
      04h  A_UINT32 4   dbglog_config   ;see "dbglog_config" description below
     When some other case:
      04h  A_UINT32 4   value           ;uh, what "value" (maybe alias for above?)

dbglog_config value:

      Bit0-15   DBGLOG_MODULE_LOG_ENABLE     ;logging enable flags for module 0-15
      Bit16     DBGLOG_REPORTING_ENABLED     ;reporting enable flag
      Bit17-19  DBGLOG_TIMESTAMP_RESOLUTION  ;timestamp resolution (default=1 ms)
      Bit20-29  DBGLOG_REPORT_SIZE           ;report size in number of messages
      Bit30-31  Reserved                     ;reserved

dbglog message value (with numeric "message" IDs):

      Bit0-15    DBGLOG_TIMESTAMP  ;contains bit8-23 of the LF0 timer (0..FFFFh)
      Bit16-25   DBGLOG_DBGID      ;minor ID (defined in "dbglog_id.h")
      Bit26-29   DBGLOG_MODULEID   ;major ID (defined in "dbglog.h")
      Bit30-31   DBGLOG_NUM_ARGS   ;whatever "num args"

WMIevent(1010h:3008h) - WMIX_DBGLOG_EVENT ;used (probably related to 2009h)
Event Data:

      Unknown (?) (probably related/enabled by WMIX_DBGLOG_CFG_MODULE_CMD)

DSi Browser does receive this - with LOTs of data (almost 1.5Kbyte)

DSi Atheros Wifi - WMI Priority Stream Functions

WMIcmd(0005h) - WMI_CREATE_PSTREAM_CMD ;aka WMI_CRE_PRIORITY_STREAM
Parameters (3Fh bytes in DSi, but other variants exist, too):

      old 3Fh 40h  <---- total size (on DSi it's 3Fh, ie. middle column)
      0Bh 00h 00h  A_UINT32 4  minServiceInt      ;in msec (14h=20)
      0Fh 04h 04h  A_UINT32 4  maxServiceInt      ;in msec (14h=20)
      13h 08h 08h  A_UINT32 4  inactivityInt      ;in msec (98967Fh=9999999)
      17h 0Ch 0Ch  A_UINT32 4  suspensionInt      ;in msec (-1)
      1Bh 10h 10h  A_UINT32 4  serviceStartTime            (0)
      1Fh 14h 14h  A_UINT32 4  minDataRate        ;in bps  (14500h=83200)
      23h 18h 18h  A_UINT32 4  meanDataRate       ;in bps  (14500h=83200)
      27h 1Ch 1Ch  A_UINT32 4  peakDataRate       ;in bps  (14500h=83200)
      2Bh 20h 20h  A_UINT32 4  maxBurstSize                (0)
      2Fh 24h 24h  A_UINT32 4  delayBound                  (0)
      33h 28h 28h  A_UINT32 4  minPhyRate         ;in bps  (5B8D80h=6000000)
      37h 2Ch 2Ch  A_UINT32 4  sba                         (2000h=8192)
      3Bh 30h 30h  A_UINT32 4  mediumTime                  (0)
      07h 34h 34h  A_UINT16 2  nominalMSDU        ;in octeCts   (80D0h=?)
      09h 36h 36h  A_UINT16 2  maxMSDU            ;in octeCts   (00D0h=?)
      00h 38h 38h  A_UINT8  1  trafficClass                     (00h)
      01h 39h 39h  A_UINT8  1  trafficDirection   ;DIR_TYPE     (02h=Bidir)
      02h 3Ah 3Ah  A_UINT8  1  rxQueueNum                       (FFh)
      03h 3Bh 3Bh  A_UINT8  1  trafficType        ;TRAFFIC_TYPE (01h=Periodic)
      04h 3Ch 3Ch  A_UINT8  1  voicePSCapability  ;VOICEPS_CAP_TYPE      (00h)
      05h 3Dh 3Dh  A_UINT8  1  tsid                                      (05h)
      06h 3Eh 3Eh  A_UINT8  1  userPriority       ;802.1D user priority  (00h)
      -   -   3Fh  A_UINT8  1  nominalPHY         ;nominal phy rate

Old wmi.h source code from 2006 used 8bit/16bit/32bit parameter ordering, later source code reversed that to 32bit/16bit/8bit and added an extra "nominalPHY" entry. DSi uses the new ordering, but without the extra entry.
DIR_TYPE values:

      UPLINK_TRAFFIC         = 0
      DNLINK_TRAFFIC         = 1
      BIDIR_TRAFFIC          = 2

TRAFFIC_TYPE values:

      TRAFFIC_TYPE_APERIODIC = 0
      TRAFFIC_TYPE_PERIODIC  = 1

VOICEPS_CAP_TYPE values:

      DISABLE_FOR_THIS_AC    = 0
      ENABLE_FOR_THIS_AC     = 1
      ENABLE_FOR_ALL_AC      = 2

XXX see WMI_CRE_PRIORITY_STREAM_REPLY ????
WMIcmd(0006h) - WMI_DELETE_PSTREAM_CMD ;aka WMI_DEL_PRIORITY_STREAM
Parameters (05h bytes):

      00h  A_UINT8  1   txQueueNumber
      01h  A_UINT8  1   rxQueueNumber
      02h  A_UINT8  1   trafficDirection
      03h  A_UINT8  1   trafficClass
      04h  A_UINT8  1   tsid

XXX see WMI_DEL_PRIORITY_STREAM_REPLY ????
WMIevent(1007h) - WMI_PSTREAM_TIMEOUT_EVENT
Event Data (04h bytes):

      00h  A_UINT8  1  txQueueNumber
      01h  A_UINT8  1  rxQueueNumber
      02h  A_UINT8  1  trafficDirection
      03h  A_UINT8  1  trafficClass

DSi Atheros Wifi - WMI Roam Functions

WMIcmd(0029h) - WMI_SET_ROAM_CTRL_CMD
Parameters (09h bytes on DSi?, but would be greater if "numBss>1"):

          PREPACK union {
      ..    A_UINT8  bssid[ATH_MAC_LEN]       ;WMI_FORCE_ROAM
      ..    A_UINT8  roamMode                 ;WMI_SET_ROAM_MODE
      ..    WMI_BSS_BIAS_INFO bssBiasInfo     ;WMI_SET_HOST_BIAS
      ..    WMI_LOWRSSI_SCAN_PARAMS lrScanParams
          } POSTPACK info
      ..  A_UINT8    roamCtrlType

This command is used to influence the Roaming behaviour.
Set the host biases of the BSSs before setting the roam mode as bias based.
WMI_ROAM_CTRL_TYPE, Different types of Roam Control:

            WMI_FORCE_ROAM              = 1  ;Roam to the specified BSSID
            WMI_SET_ROAM_MODE           = 2  ;default, progd bias, no roam
            WMI_SET_HOST_BIAS           = 3  ;Set the Host Bias
            WMI_SET_LOWRSSI_SCAN_PARAMS = 4  ;Set lowrssi Scan parameters

WMI_ROAM_MODE, aka ROAM MODES:

            WMI_DEFAULT_ROAM_MODE       = 1  ;RSSI based ROAM
            WMI_HOST_BIAS_ROAM_MODE     = 2  ;HOST BIAS based ROAM
            WMI_LOCK_BSS_MODE           = 3  ;Lock to the Current BSS - no Roam

BSS HOST BIAS INFO structures:

      WMI_BSS_BIAS typedef PREPACK struct:
            6    A_UINT8  bssid[ATH_MAC_LEN]
            1    A_INT8   bias
      WMI_BSS_BIAS_INFO typedef PREPACK struct:
        00h 1    A_UINT8  numBss
        01h 7*N  WMI_BSS_BIAS bssBias[1]
      WMI_LOWRSSI_SCAN_PARAMS typedef PREPACK struct WMI_LOWRSSI_SCAN_PARAMS:
        00h 2    A_UINT16 lowrssi_scan_period
        02h 2    A_INT16  lowrssi_scan_threshold
        04h 2    A_INT16  lowrssi_roam_threshold
        06h 1    A_UINT8  roam_rssi_floor
        07h 1    A_UINT8  reserved[1]               ;for alignment

WMIcmd(002Ah) - WMI_GET_ROAM_TBL_CMD ;aka WMI_REPORT_ROAM_TBL ;reply 100Fh
Parameters:

      Unknown (none?)

Reply: See WMI_REPORT_ROAM_TBL_EVENT
WMIevent(100Fh) - WMI_REPORT_ROAM_TBL_EVENT ;related to CMD 002Ah ?
Event Data (14h bytes on DSi, might be more on other systems if numEntries>1):

      00h  A_UINT16           2      roamMode
      02h  A_UINT16           2      numEntries
      04h  WMI_BSS_ROAM_INFO  N*10h  bssRoamInfo[1]

WMI_BSS_ROAM_INFO structure:

        A_INT32 4  roam_util
        A_UINT8 6  bssid[ATH_MAC_LEN]
        A_INT8  1  rssi
        A_INT8  1  rssidt
        A_INT8  1  last_rssi
        A_INT8  1  util
        A_INT8  1  bias
        A_UINT8 1  reserved         ;for alignment

MAX_ROAM_TBL_CAND = 5
Names: WMI_GET_ROAM_TBL aka WMI_REPORT_ROAM_TBL aka WMI_TARGET_ROAM_TBL

DSi Atheros Wifi - WMI Power Functions

WMIcmd(0012h) - WMI_SET_POWER_MODE_CMD ;aka WMI_POWER_MODE_CMD
Parameters (01h bytes):

      00h  A_UINT8  1   powerMode           ;WMI_POWER_MODE

WMI_POWER_MODE values:

      REC_POWER      = 01h     ;recommended,receive,record,rectal?
      MAX_PERF_POWER = 02h     ;maximum performance,perforation?

WMIcmd(0013h) - WMI_SET_IBSS_PM_CAPS_CMD ;aka WMI_IBSS_PM_CAPS_CMD
Parameters (06h bytes):

      00h  A_UINT8  1  power_saving
      01h  A_UINT8  1  ttl                  ;number of beacon periods
      02h  A_UINT16 2  atim_windows         ;msec
      04h  A_UINT16 2  timeout_value        ;msec

Adhoc power save types aka WMI_ADHOC_PS_TYPE:

      ADHOC_PS_DISABLE = 1
      ADHOC_PS_ATH     = 2
      ADHOC_PS_IEEE    = 3
      ADHOC_PS_OTHER   = 4

WMIcmd(0014h) - WMI_SET_POWER_PARAMS_CMD ;aka WMI_POWER_PARAMS_CMD
Parameters (06h bytes on DSi?, but other sources claim 0Ch bytes):

      06h 0Ch   <---- total size (on DSi it's 06h, ie. left column)
      00h 00h  A_UINT16 2   idle_period             ;msec
      02h 02h  A_UINT16 2   pspoll_number
      04h 04h  A_UINT16 2   dtim_policy
      --  06h  A_UINT16 2   tx_wakeup_policy
      --  08h  A_UINT16 2   num_tx_to_wakeup
      --  0Ah  A_UINT16 2   ps_fail_event_policy

WMI_DTIM_POLICY values:

      IGNORE_DTIM = 01h
      NORMAL_DTIM = 02h
      STICK_DTIM  = 03h
      AUTO_DTIM   = 04h

WMI_TX_WAKEUP_POLICY_UPON_SLEEP values (Policy to determnine (Nine?) whether TX should wakeup WLAN if sleeping):

      TX_WAKEUP_UPON_SLEEP      = 1
      TX_DONT_WAKEUP_UPON_SLEEP = 2

POWER_SAVE_FAIL_EVENT_POLICY values (Policy to determnine (Nine?) whether power save failure event should be sent to host during scanning):

      SEND_POWER_SAVE_FAIL_EVENT_ALWAYS        = 1
      IGNORE_POWER_SAVE_FAIL_EVENT_DURING_SCAN = 2

WMIcmd(0015h) - WMI_SET_POWERSAVE_TIMERS_POLICY_CMD ;aka WMI_POWERSAVE...
Parameters (0Ch bytes):

      00h  A_UINT16 2  psPollTimeout (msec)
      02h  A_UINT16 2  triggerTimeout (msec)
      04h  A_UINT32 4  apsdTimPolicy (TIM behavior with ques (=?) APSD enabled.
                        Default is IGNORE_TIM_ALL_QUEUES_APSD)
      08h  A_UINT32 4  simulatedAPSDTimPolicy (TIM behavior with simulated APSD
                        enabled. Default is PROCESS_TIM_SIMULATED_APSD)

APSD_TIM_POLICY values:

      IGNORE_TIM_ALL_QUEUES_APSD  = 0
      PROCESS_TIM_ALL_QUEUES_APSD = 1
      IGNORE_TIM_SIMULATED_APSD   = 2
      PROCESS_TIM_SIMULATED_APSD  = 3

WMIcmd(001Bh) - WMI_SET_TX_PWR_CMD
Parameters:

      00h  A_UINT8  1   dbM                 ;in dbM units

WMIcmd(001Ch) - WMI_GET_TX_PWR_CMD ;aka WMI_TX_PWR ;reply 001Ch
Parameters:

      None

Reply:

      00h  A_UINT8  1   dbM                 ;in dbM units

WMIcmd(0047h) - WMI_START_WHATEVER_TIMER_CMD ;-special DSi command?
This seems to be a nintendo-specific command. It seems to be related to power control functions (maybe similar to WMI_SET_AP_PS_CMD, but with changed command number and fewer parameters). The command seems to start a timer, and the firmware perhaps does something when the timer has ellapsed?
Parameters (04h bytes):

      -   00h  A_UINT32 4   time           ;in msec or so?   ;used: 00000002h

WMIcmd(0048h) - WMI_SET_AP_PS_CMD ;aka WMI_AP_PS_CMD ;not implemented on DSi
This supported in most or all atheros code versions, but DSi doesn't support it.
Parameters (0Ah bytes):

      -   00h  A_UINT32 4   idle_time      ;in msec
      -   04h  A_UINT32 4   ps_period      ;in usec
      -   08h  A_UINT8  1   sleep_period   ;in ps_period's (=above "ps_period"?)
      -   09h  A_UINT8  1   psType         ;AP power save type

WMI_AP_PS_TYPE, AP power save types:

      AP_PS_DISABLE = 1
      AP_PS_ATH     = 2

DSi Atheros Wifi - WMI Statistics Function

WMIcmd(0010h) - WMI_GET_STATISTICS_CMD ;reply WMI_REPORT_STATISTICS
Parameters:

      Unknown (none?)

WMIevent(100Bh) - WMI_REPORT_STATISTICS_EVENT ;related to CMD 0010h
Event Data (D5h bytes on DSi, although other sources claim A9h or EDh bytes):

      A9h D5h EDh  <---- total size (on DSi it's D5h, ie. middle column)
      --  00h 00h A_UINT32 4  lqVal                    ;-  <-- newer version only
      --  04h 04h A_INT32  4  noise_floor_calibation   ;-  <-- newer version only
      --  08h 08h A_UINT32 4  power_save_failure_cnt   ;\pm_stats_t (new)
      --  --  0Ch A_UINT16 2  stop_tx_failure_cnt      ;   <-- NEWEST version only
      --  --  0Eh A_UINT16 2  atim_tx_failure_cnt      ;   <-- NEWEST version only
      --  --  10h A_UINT16 2  atim_rx_failure_cnt      ;   <-- NEWEST version only
      --  --  12h A_UINT16 2  bcn_rx_failure_cnt       ;/  <-- NEWEST version only
      00h 0Ch 14h A_UINT32 4  tx_packets               ;\
      04h 10h 18h A_UINT32 4  tx_bytes                 ;
      08h 14h 1Ch A_UINT32 4  tx_unicast_pkts          ;
      0Ch 18h 20h A_UINT32 4  tx_unicast_bytes         ; tx_stats_t
      10h 1Ch 24h A_UINT32 4  tx_multicast_pkts        ;
      14h 20h 28h A_UINT32 4  tx_multicast_bytes       ;
      18h 24h 2Ch A_UINT32 4  tx_broadcast_pkts        ;
      1Ch 28h 30h A_UINT32 4  tx_broadcast_bytes       ;
      20h 2Ch 34h A_UINT32 4  tx_rts_success_cnt       ;
      24h 30h 38h A_UINT32 16 tx_packet_per_ac[4]      ;
      --  40h 48h A_UINT32 16 tx_errors_per_ac[4]      ;   <-- newer version only
      34h 50h 58h A_UINT32 4  tx_errors                ;
      38h 54h 5Ch A_UINT32 4  tx_failed_cnt            ;
      3Ch 58h 60h A_UINT32 4  tx_retry_cnt             ;
      --  --  64h A_UINT32 4  tx_mult_retry_cnt        ;   <-- NEWEST version only
      40h 5Ch 68h A_UINT32 4  tx_rts_fail_cnt          ;
      --  60h 6Ch A_INT32  4  tx_unicast_rate          ;/  <-- newer version only
      44h 64h 70h A_UINT32 4  rx_packets               ;\
      48h 68h 74h A_UINT32 4  rx_bytes                 ;
      4Ch 6Ch 78h A_UINT32 4  rx_unicast_pkts          ;
      50h 70h 7Ch A_UINT32 4  rx_unicast_bytes         ;
      54h 74h 80h A_UINT32 4  rx_multicast_pkts        ; rx_stats_t
      58h 78h 84h A_UINT32 4  rx_multicast_bytes       ;
      5Ch 7Ch 88h A_UINT32 4  rx_broadcast_pkts        ;
      60h 80h 8Ch A_UINT32 4  rx_broadcast_bytes       ;
      64h 84h 90h A_UINT32 4  rx_fragment_pkt          ;
      68h 88h 94h A_UINT32 4  rx_errors                ;
      6Ch 8Ch 98h A_UINT32 4  rx_crcerr                ;
      70h 90h 9Ch A_UINT32 4  rx_key_cache_miss        ;
      74h 94h A0h A_UINT32 4  rx_decrypt_err           ;
      78h 98h A4h A_UINT32 4  rx_duplicate_frames      ;
      --  9Ch A8h A_INT32  4  rx_unicast_rate          ;/  <-- newer version only
      7Ch A0h ACh A_UINT32 4  tkip_local_mic_failure         ;\
      80h A4h B0h A_UINT32 4  tkip_counter_measures_invoked  ;
      84h A8h B4h A_UINT32 4  tkip_replays                   ; tkip_ccmp_stats_t
      88h ACh B8h A_UINT32 4  tkip_format_errors             ;
      8Ch B0h BCh A_UINT32 4  ccmp_format_errors             ;
      90h B4h C0h A_UINT32 4  ccmp_replays                   ;/
      --  B8h C4h A_UINT32 4  wow_num_pkts_dropped           ;\
      --  BCh C8h A_UINT16 2  wow_num_events_discarded       ; wlan_wow_stats_t
      --  BEh CAh A_UINT8  1  wow_num_host_pkt_wakeups       ;
      --  BFh CBh A_UINT8  1  wow_num_host_event_wakeups     ;/
      --  --  CCh A_UINT32 4  arp_received                   ;\
      --  --  D0h A_UINT32 4  arp_matched                    ; arp_stats_t
      --  --  D4h A_UINT32 4  arp_replied                    ;/
      94h C0h D8h A_UINT32 4  cs_bmiss_cnt             ;\
      98h C4h DCh A_UINT32 4  cs_lowRssi_cnt           ;
      9Ch C8h E0h A_UINT16 2  cs_connect_cnt           ; cserv_stats_t
      9Eh CAh E2h A_UINT16 2  cs_disconnect_cnt        ;
      A0h CCh E4h A_INT16  2  cs_aveBeacon_rssi        ;
      --  CEh E6h A_UINT16 2  cs_roam_count            ;   <-- newer version only
      --  D0h E8h A_INT16  2  cs_rssi                  ;   <-- newer version only
      --  D2h EAh A_UINT8  1  cs_snr                   ;   <-- newer version only
      --  D3h EBh A_UINT8  1  cs_aveBeacon_snr         ;   <-- newer version only
      A2h D4h ECh A_UINT8  1  cs_lastRoam_msec         ;/
      A3h --  --  A_UINT32 4  power_save_failure_cnt   ;-pm_stats_t (old)
      A7h --  --  A_INT16  2  noise_floor_calibation   ;-old version only

The D5h-byte structure was found in AR6kSDK.build_sw.18 from 2006.
The A9h-byte structure was found in older (AR6001?) source from 2006.
The EDh-byte structure was found in newer source from 2008 and up.
Names: WMI_GET_STATISTICS aka WMI_REPORT_STATISTICS aka WMI_TARGET_STATS

DSi Atheros Wifi - WMI Bluetooth Coexistence (older AR6002)

Bluetooth Coexistence support has underwent significant changes:

      Older AR6002 from 2008 ;-original Bluetooth COEX version
      Newer AR6002 from 2008 ;\same commands as above, but with entirely different
      Newer AR6002 from 2010 ;/parameters (and minor changes for 2008 vs 2010)
      AR6003 from 2010       ;-completely different commands for Bluetooth COEX

Below are Bluetooth COEX functions for OLDER AR6002 - as used on DSi - and as defined in "AR6kSDK.build_sw.18".
On DSi, AR6002 does handle command 003Ch and 003Ch, but AR6013/AR6014 do merely redirect them to dummy handlers; despite of also having (unused) actual handlers for those commands.
WMIcmd(003Bh) - WMI_SET_BT_STATUS_CMD ;AR6002 Bluetooth Coexistence only?
Parameters (02h bytes):

      00h  A_UINT8  1   streamType          ;aka BT_STREAM_TYPE ?
      01h  A_UINT8  1   status              ;aka BT_STREAM_STATUS ?

BT_STREAM_TYPE values:

      BT_STREAM_UNDEF = 0                   ;\
      BT_STREAM_SCO   = 1 ;SCO stream       ; only this three types in Older AR6002
      BT_STREAM_A2DP  = 2 ;A2DP stream      ;/

BT_STREAM_STATUS values:

      BT_STATUS_UNDEF        = 0  ;\
      BT_STATUS_START        = 1  ; this five states in Older AR6002
      BT_STATUS_STOP         = 2  ; (Newer A6002 has added/removed/renamed states)
      BT_STATUS_RESUME       = 3  ;
      BT_STATUS_SUSPEND      = 4  ;/

AR6002 only? (although other comment says "COMMON to AR6002 and AR6003"?)
WMIcmd(003Ch) - WMI_SET_BT_PARAMS_CMD ;AR6002 Bluetooth Coexistence only?
Parameters (16h bytes on DSi?, whatever that might match up with below?):

     when paramType=1=BT_PARAM_SCO:    ;SCO stream parameters (BT_PARAMS_SCO)
      00h  A_UINT8  1   noSCOPkts
      01h  A_UINT8  1   pspollTimeout
      02h  A_UINT8  1   stompbt
      03h  PAD      12h undefined/padding
     when paramType=2=BT_PARAM_A2DP:   ;whatever (BT_PARAMS_A2DP)
      00h  A_UINT32 4   period
      04h  A_UINT32 4   dutycycle
      08h  A_UINT8  1   stompbt
      09h  PAD      0Ch undefined/padding
     when paramType=3=BT_PARAM_MISC and paramSubType=1=WLAN_PROTECT_POLICY:
      00h  A_UINT32 4   period
      04h  A_UINT32 4   dutycycle
      08h  A_UINT8  1   stompbt
      09h  A_UINT8  1   policy
      0Ah  A_UINT8  1   paramSubType  (=1 in this case)
      0Bh  PAD      0Ah undefined/padding
     when paramType=3=BT_PARAM_MISC and paramSubType=2=WLAN_COEX_CTRL_FLAGS:
      00h  A_UINT16 2   wlanCtrlFlags
      02h  PAD      8   undefined/padding
      0Ah  A_UINT8  1   paramSubType  (=2 in this case)
      0Bh  PAD      0Ah undefined/padding
     when paramType=4=BT_PARAM_REGS:   ;co-existence register params (BT_COEX_REGS)
      00h  A_UINT32 4   mode
      04h  A_UINT32 4   scoWghts
      08h  A_UINT32 4   a2dpWghts
      0Ch  A_UINT32 4   genWghts
      10h  A_UINT32 4   mode2
      14h  A_UINT8  1   setVal
     and, in all cases:
      15h  A_UINT8  1   paramType    ;<-- selects which of the above to use

Below might be "policy" for WLAN_PROTECT_POLICY(?):

      WLAN_PROTECT_PER_STREAM = 01h   /* default
      WLAN_PROTECT_ANY_TX     = 02h

Below might be "wlanCtrlFlags" for WLAN_COEX_CTRL_FLAGS(?):

      WLAN_DISABLE_COEX_IN_DISCONNECT = 0001h   ;default
      WLAN_KEEP_COEX_IN_DISCONNECT    = 0002h
      WLAN_STOMPBT_IN_DISCONNECT      = 0004h
      WLAN_DISABLE_COEX_IN_ROAM       = 0010h   ;default
      WLAN_KEEP_COEX_IN_ROAM          = 0020h
      WLAN_STOMPBT_IN_ROAM            = 0040h
      WLAN_DISABLE_COEX_IN_SCAN       = 0100h   ;default
      WLAN_KEEP_COEX_IN_SCAN          = 0200h
      WLAN_STOMPBT_IN_SCAN            = 0400h
      WLAN_DISABLE_COEX_BT_OFF        = 1000h   ;default
      WLAN_KEEP_COEX_BT_OFF           = 2000h
      WLAN_STOMPBT_BT_OFF             = 4000h

DSi Atheros Wifi - WMI Wake on Wireless (WOW) Functions

WMIcmd(0042h) - WMI_SET_HOST_SLEEP_MODE_CMD
Parameters (08h bytes on DSi?, so, a BOOL must be 4 bytes?):

      00h  A_BOOL   4  awake;
      04h  A_BOOL   4  asleep;

See also: WMI_SET_HOST_SLEEP_MODE_CMD_PROCESSED_EVENT
WMIcmd(0043h) - WMI_SET_WOW_MODE_CMD
Event Data (04h bytes on DSi?, but other sources claim MORE bytes?):

      04h ??h   <---- total size (on DSi it's 04h, ie. left column)
      00h 00h  A_BOOL         4   enable_wow
      --  04h  WMI_WOW_FILTER ..  filter ;UINTx or so? with "WMI_WOW_FILTER" value?
      --  ..   A_UINT16       2   hostReqDelay

WMI_WOW_FILTER values (only one defined):

      WOW_FILTER_SSID = 01h

WMIcmd(0044h) - WMI_GET_WOW_LIST_CMD ;reply 1018h (!)
Parameters:

      00h  A_UINT8  1   filter_list_id;

Reply (88h bytes on DSi): WMI_GET_WOW_LIST_EVENT:

      00h  A_UINT8    1      num_filters     /* number of patterns in reply
      01h  A_UINT8    1      this_filter_num /* filter # x of total num_filters
      02h  A_UINT8    1      wow_mode
      03h  A_UINT8    1      host_mode
      04h  WOW_FILTER N*84h  wow_filters[1]

WOW_FILTER structure:

        A_UINT8 1    wow_valid_filter;
        A_UINT8 1    wow_filter_id;
        A_UINT8 1    wow_filter_size;
        A_UINT8 1    wow_filter_offset;
        A_UINT8 40h  wow_filter_mask[WOW_MASK_SIZE];
        A_UINT8 40h  wow_filter_pattern[WOW_PATTERN_SIZE];

There's also a "WOW_FILTER_LIST" structure (unknown purpose):

        A_UINT8    1      wow_valid_list;
        A_UINT8    1      wow_list_id;
        A_UINT8    1      wow_num_filters;
        A_UINT8    1      wow_total_list_size;
        WOW_FILTER 4*84h  list[WOW_MAX_FILTERS_PER_LIST];
     #define WOW_MAX_FILTER_LISTS     = 1     /*  4  */
     #define WOW_MAX_FILTERS_PER_LIST = 4
     #define WOW_PATTERN_SIZE         = 64
     #define WOW_MASK_SIZE            = 64

WMIcmd(0045h) - WMI_ADD_WOW_PATTERN_CMD
Parameters:

      00h  A_UINT8  1   filter_list_id;
      01h  A_UINT8  1   filter_size;
      02h  A_UINT8  1   filter_offset;
      03h  A_UINT8  ..  filter[1];

WMIcmd(0046h) - WMI_DEL_WOW_PATTERN_CMD
Parameters (04h bytes):

      00h  A_UINT16 2   filter_list_id;
      02h  A_UINT16 2   filter_id;

WMIevent(1018h) - WMI_GET_WOW_LIST_EVENT ;reply to CMD 0044h
See WMI_GET_WOW_LIST_CMD for response details.

DSi Atheros Wifi - WMI General Purpose I/O (GPIO) Functions

WMIcmd(002Eh:2003h) - WMIX_GPIO_OUTPUT_SET_CMD ;reply=3006h
Parameters:

      00h  A_UINT32  4     set_mask;             /* pins to set
      04h  A_UINT32  4     clear_mask;           /* pins to clear
      08h  A_UINT32  4     enable_mask;          /* pins to enable for output
      0Ch  A_UINT32  4     disable_mask;         /* pins to disable/tristate

Set GPIO pin output state.
In order for output to be driven, a pin must be enabled for output.
This can be done during initialization through the GPIO Configuration DataSet, or during operation with the enable_mask.
If a request is made to simultaneously set/clear or set/disable or clear/disable or disable/enable, results are undefined.
NB: Some of the WMIX APIs use a 32-bit mask. On Targets that support more than 32 GPIO pins, those APIs only support the first 32 GPIO pins.
WMIcmd(002Eh:2004h) - WMIX_GPIO_INPUT_GET_CMD ;reply=3005h
Parameters:

      Unknown (none?)

WMIcmd(002Eh:2005h) - WMIX_GPIO_REGISTER_SET_CMD ;reply=3006h, too
Parameters:

      00h  A_UINT32  4    gpioreg_id;           /* GPIO register ID
      04h  A_UINT32  4    value;                /* value to write

Set a GPIO register. For debug/exceptional cases.
Values for gpioreg_id are GPIO_ID_*, defined in a platform-dependent header, gpio.h.
WMIcmd(002Eh:2006h) - WMIX_GPIO_REGISTER_GET_CMD ;reply=3005h, too
Parameters:

      00h  A_UINT32  4    gpioreg_id;           /* GPIO register to read

Get a GPIO register. For debug/exceptional cases.
WMIcmd(002Eh:2007h) - WMIX_GPIO_INTR_ACK_CMD
Parameters:

        A_UINT32              ack_mask;             /* interrupts to acknowledge

Host acknowledges and re-arms GPIO interrupts. A single message should be used to acknowledge all interrupts that were delivered in an earlier WMIX_GPIO_INTR_EVENT message.
WMIevent(1010h:3004h) - WMIX_GPIO_INTR_EVENT ;used (interrupt)
Event Data:

      00h  A_UINT32  4   intr_mask;            /* pending GPIO interrupts
      04h  A_UINT32  4   input_values;         /* recent GPIO input values

Target informs Host of GPIO interrupts that have ocurred since the last WMIX_GIPO_INTR_ACK_CMD was received. Additional information -- the current GPIO input values is provided -- in order to support use of a GPIO interrupt as a Data Valid signal for other GPIO pins.
WMIevent(1010h:3005h) - WMIX_GPIO_DATA_EVENT ;used (reply to 2004h and 2006h)
Event Data:

      00h  A_UINT32  4   value;
      04h  A_UINT32  4   reg_id;

Target responds to Host's earlier WMIX_GPIO_INPUT_GET_CMD request using a GPIO_DATA_EVENT with value set to the mask of GPIO pin inputs and reg_id set to GPIO_ID_NONE.
Target responds to Hosts's earlier WMIX_GPIO_REGISTER_GET_CMD request using a GPIO_DATA_EVENT with value set to the value of the requested register and reg_id identifying the register (reflects the original request).
NB: reg_id supports the future possibility of unsolicited WMIX_GPIO_DATA_EVENTs (for polling GPIO input), and it may simplify Host GPIO support.
WMIevent(1010h:3006h) - WMIX_GPIO_ACK_EVENT ;used (reply to 2003h and 2005h)
Event Data:

      Unknown (none?) (confirms GPIO_xxx_SET commands)

GPIO Constants

      AR6001_GPIO_PIN_COUNT   = 18
      AR6002_GPIO_PIN_COUNT   = 18  ;aka hw2.0
      AR6003_GPIO_PIN_COUNT   = 28  ;aka hw4.0 ;XXX shouldn't that be 26 ?
      MCKINLEY_GPIO_PIN_COUNT = 57  ;aka hw6.0

Values of gpioreg_id in the WMIX_GPIO_REGISTER_SET_CMDID and WMIX_GPIO_REGISTER_GET_CMDID commands come in two flavors. If the upper bit of gpioreg_id is CLEAR, then the remainder is interpreted as one of these values. This provides platform-independent access to GPIO registers. If the upper bit (GPIO_ID_OFFSET_FLAG) of gpioreg_id is SET, then the remainder is interpreted as a platform-specific GPIO register offset.

      GPIO_ID_OUT         = 00000000h
      GPIO_ID_OUT_W1TS    = 00000001h
      GPIO_ID_OUT_W1TC    = 00000002h
      GPIO_ID_ENABLE      = 00000003h
      GPIO_ID_ENABLE_W1TS = 00000004h
      GPIO_ID_ENABLE_W1TC = 00000005h
      GPIO_ID_IN          = 00000006h
      GPIO_ID_STATUS      = 00000007h
      GPIO_ID_STATUS_W1TS = 00000008h
      GPIO_ID_STATUS_W1TC = 00000009h
      GPIO_ID_PIN0        = 0000000Ah
      GPIO_ID_PIN(n)      = (GPIO_ID_PIN0+(n))  ;=0000000Ah and up
      GPIO_ID_NONE        = FFFFFFFFh
      GPIO_ID_OFFSET_FLAG       = 80000000h
      GPIO_ID_REG_MASK          = 7fffffffh
      GPIO_ID_IS_OFFSET(reg_id) = (((reg_id) & GPIO_ID_OFFSET_FLAG) != 0)

DSi Atheros Wifi - Unimplemented WMI Misc Functions

Not implemented in DSi.
WMIcmd(002Bh) - WMI_GET_ROAM_DATA_CMD ;reply 1015h ? ;not implemented in DSi
Parameters:

      Unknown (none?)

Reply: See WMI_REPORT_ROAM_DATA_EVENT
WMIevent(1015h) - WMI_REPORT_ROAM_DATA_EVENT

      ;-not implemented in DSi ;related to 002Bh?

Event Data:

           PREPACK union {
      00h      WMI_TARGET_ROAM_TIME roamTime;
           } POSTPACK u;
      14h  A_UINT8 roamDataType ;

ROAM_DATA_TYPE values (only one defined)

      ROAM_DATA_TIME = 1          /* Get The Roam Time Data

WMI_TARGET_ROAM_TIME structure:

      00h  A_UINT32  4     disassoc_time
      04h  A_UINT32  4     no_txrx_time
      08h  A_UINT32  4     assoc_time
      0Ch  A_UINT32  4     allow_txrx_time
      10h  A_UINT8   6     disassoc_bssid[ATH_MAC_LEN]
      16h  A_INT8    1     disassoc_bss_rssi
      17h  A_UINT8   6     assoc_bssid[ATH_MAC_LEN]      ;UNALIGNED!!!
      1Dh  A_INT8    1     assoc_bss_rssi

Names: WMI_GET_ROAM_DATA aka WMI_REPORT_ROAM_DATA aka WMI_TARGET_ROAM_DATA
WMIcmd(002Ch) - WMI_ENABLE_RM_CMD ;not implemented in DSi
Parameters:

      00h  A_BOOL   4    enable_radio_measurements;

WMIcmd(002Dh) - WMI_SET_MAX_OFFHOME_DURATION_CMD ;not implemented in DSi
Parameters:

      00h  A_UINT8  1    max_offhome_duration;

WMIcmd(002Eh:200Ah) - WMIX_PROF_CFG_CMD
WMIcmd(002Eh:200Bh) - WMIX_PROF_ADDR_SET_CMD
WMIcmd(002Eh:200Ch) - WMIX_PROF_START_CMD
WMIcmd(002Eh:200Dh) - WMIX_PROF_STOP_CMD
WMIcmd(002Eh:200Eh) - WMIX_PROF_COUNT_GET_CMD ;reply 3009h
Not implemented in DSi. Said to be "Target Profiling support".
Parameter structures are defined only for WMIX_PROF_CFG_CMD and WMIX_PROF_ADDR_SET_CMD.
Parameters for WMIX_PROF_CFG_CMD:

      00h  A_UINT32 4   period;     /* Time (in 30.5us ticks) between samples
      04h  A_UINT32 4   nbins;

Parameters for WMIX_PROF_ADDR_SET_CMD:

      00h  A_UINT32 4   addr;

Maybe the other three WMIX_PROF_xxx_CMD's don't have any parameters.
See also: WMIX_PROF_COUNT_EVENT
WMIevent(1010h:3009h) - WMIX_PROF_COUNT_EVENT ;-not implemented in DSi
Not implemented in DSi. Response to WMIX_PROF_COUNT_GET_CMD.
Event Data:

      00h  A_UINT32  4     addr;
      04h  A_UINT32  4     count;

Target responds to Hosts's earlier WMIX_PROF_COUNT_GET_CMD request using a WMIX_PROF_COUNT_EVENT with addr set to the next address count set to the corresponding count.
WMIcmd(003Ah) - WMI_TEST_CMD ;not implemented in DSi
Parameters:

      Unknown (maybe related to file "testcmd.h"?)

WMIevent(1016h) - WMI_TEST_EVENT ;not implemented in DSi
Event Data:

      Unknown (maybe related to file "testcmd.h"?) (or general purpose?)

WMIcmd(0040h) - WMI_GET_APPIE_CMD ;aka GET_APP_IE ;not implemented in DSi
Parameters:

      Unknown (none?)

Reply: Unknown:

      EVENTID is unknown (maybe 0040h, ie. same as GET_APPIE_CMD)
      Reply structure is unknown (maybe same parameter structure for SET_APPIE_CMD)

WMIcmd(004Ah) - WMI_SET_IE_CMD ;not implemented in DSi (newer 2012 stuff)
Parameters:

      00h   u8  1   ie_id;
      01h   u8  1   ie_field;    /* enum wmi_ie_field_type
      02h   u8  1   ie_len;
      03h   u8  1   reserved;
      04h   u8  ..  ie_info[0];

wmi_ie_field_type:

      WMI_RSN_IE_CAPB = 01h
      WMI_IE_FULL     = FFh  /* indicats full IE    ;uh, kittykats?

See also: WMI_SET_APP_IE_CMD (similar older command)
WMIcmd(08xxh) - wil6210: WILOCITY types ;not implemented in DSi
WMIcmd(09xxh) - wil6210: Performance monitoring ;not implemented in DSi

      not implemented in DSi

WMIcmd(F003h, or formerly 0047h) - WMI_SET_MAC_ADDRESS_CMD
Parameters:

      00h  A_UINT8  6   macaddr[ATH_MAC_LEN];

WMIcmd(F007h) - WMI_ABORT_SCAN_CMD ;not implemented in DSi
Parameters:

      Unknown (none?)

Reply: Unknown, if any (see (optional?) SCAN_ABORT_EVENT)
WMIcmd(F008h) - WMI_SET_TARGET_EVENT_REPORT_CMD ;not implemented in DSi
Parameters:

      00h  A_UINT32 1   evtConfig;

TARGET_EVENT_REPORT_CONFIG values:

      DISCONN_EVT_IN_RECONN    = 0   ;default
      NO_DISCONN_EVT_IN_RECONN = 1

Apparently related to cases where to throw WMI_DISCONNECT_EVENT.
WMIcmd(F017h or formerly F016h) - WMI_SET_IP_CMD
Parameters:

      00h  A_UINT32 4*2  ips[MAX_IP_ADDRS]   ;IP in Network Byte Order

#define MAX_IP_ADDRS 2
WMIcmd(F018h or formerly F017h) - WMI_SET_PARAMS_CMD ;reply=101Fh
Parameters:

      00h  A_UINT32 4   opcode;
      04h  A_UINT32 4   length;
      08h  A_CHAR   ... buffer[1];      /* WMI_SET_PARAMS

Reply: See WMI_SET_PARAMS_REPLY_EVENT
WMIevent(101Fh) - WMI_SET_PARAMS_REPLY_EVENT ;reply to "SET" CMD F018h
Event Data:

      00h  A_INT8  1   status;      /* WMI_SET_PARAMS_REPLY

Reply to WMI_SET_PARAMS_CMD (?) aka WMI_SET_PARAMS_REPLY aka WMI_SET_PARAMS_REPLY_EVENT.
WMIcmd(F019h or formerly F018h) - WMI_SET_MCAST_FILTER_CMD
Parameters:

      00h  A_UINT8  6   multicast_mac[ATH_MAC_LEN];   /* WMI_SET_MCAST_FILTER

WMIcmd(F01Ah or formerly F019h) - WMI_DEL_MCAST_FILTER_CMD
Parameters:

      Unknown (None?) (or maybe same as for WMI_SET_MCAST_FILTER_CMD ?)

WMIcmd(F029h) - WMI_MCAST_FILTER_CMD ;related to SET/DEL "MCAST" commands?
Parameters:

      00h  A_UINT8  1  enable;      /* WMI_MCAST_FILTER

Related to SET/DEL "MCAST" commands?
WMIcmd(F01Bh) - WMI_ALLOW_AGGR_CMD
Parameters:

      00h  A_UINT16 2   tx_allow_aggr (16bit mask to allow tx/uplink ADDBA
                         negotiation - bit position indicates tid)
      02h  A_UINT16 2   rx_allow_aggr (16bit mask to allow rx/donwlink ADDBA
                         negotiation - bit position indicates tid)

Configures tid's to allow ADDBA negotiations on each tid, in each direction.
uh, donwlink?
WMIcmd(F01Ch) - WMI_ADDBA_REQ_CMD
Parameters:

      00h  A_UINT8  1   tid

"f/w starts performing ADDBA negotiations with peer on the given tid"
"f/w" means FirmWare? ForWard? Fail/Wrong? or What?
WMIcmd(F01Dh) - WMI_DELBA_REQ_CMD
Parameters:

      00h  A_UINT8  1   tid
      01h  A_UINT8  1   is_sender_initiator

"f/w would teardown BA with peer." - uh, "f/w"?
"is_send_initiator indicates if it's or tx or rx side" - uh, "it's or"?
WMIevent(1020h) - WMI_ADDBA_REQ_EVENT
Event Data:

      00h  A_UINT8  1   tid
      01h  A_UINT8  1   win_sz
      02h  A_UINT16 2   st_seq_no
      04h  A_UINT8  1   status  "f/w response for ADDBA Req; OK(0) or failure(!=0)"

WMIevent(1021h) - WMI_ADDBA_RESP_EVENT
Event Data:

      00h  A_UINT8  1   tid
      01h  A_UINT8  1   status      /* OK(0), failure (!=0)
      02h  A_UINT16 2   amsdu_sz    /* Three values: Not supported(0), 3839, 8k

Uhm, does "8k" mean 8192 or 8000 or so?
WMIevent(1022h) - WMI_DELBA_REQ_EVENT aka WMI_DELBA_EVENT
Event Data:

      00h  A_UINT8  1   tid;
      01h  A_UINT8  1   is_peer_initiator;
      02h  A_UINT16 2   reason_code;

"f/w received a DELBA for peer and processed it. Host is notified of this."
WMIcmd(F01Eh) - WMI_SET_HT_CAP_CMD
Parameters:

      00h  A_UINT8 1  band (specifies which band to apply these values)
      01h  A_UINT8 1  enable (allows 11n to be disabled on a per band basis)
      02h  A_UINT8 1  chan_width_40M_supported
      03h  A_UINT8 1  short_GI_20MHz
      04h  A_UINT8 1  short_GI_40MHz
      05h  A_UINT8 1  intolerance_40MHz
      06h  A_UINT8 1  max_ampdu_len_exp

WMIcmd(F01Fh) - WMI_SET_HT_OP_CMD
Parameters:

      00h  A_UINT8  1   sta_chan_width;

WMIcmd(F020h) - WMI_SET_TX_SELECT_RATES_CMD
Parameters:

      00h  A_UINT32 4*8*2  rateMasks[WMI_MODE_MAX * WMI_MAX_RATE_MASK];

WMIcmd(F021h) - WMI_SET_TX_SGI_PARAM_CMD
Parameters:

      00h  A_UINT32 4*2  sgiMask[WMI_MAX_RATE_MASK];
      08h  A_UINT8  1    sgiPERThreshold;

DEFAULT_SGI_MASK_L32 = 08080000h
DEFAULT_SGI_MASK_U32 = 00000000h
DEFAULT_SGI_PER = 10
WMIcmd(F022h) - WMI_SET_RATE_POLICY_CMD
Parameters:

      00h  A_UINT32 4*2  rateField[WMI_MAX_RATE_MASK]
                          (rateField: "1 bit per rate corresponding to index")
      08h  A_UINT8  1    id    ;range 1..5 (aka 1..WMI_RATE_POLICY_ID_MAX)
      09h  A_UINT8  1    shortTrys
      0Ah  A_UINT8  1    longTrys
      0Bh  A_UINT8  1    reserved   ;padding

WMI_RATE_POLICY_ID_MAX = 5
WMIcmd(F023h) - WMI_HCI_CMD_CMD aka WMI_HCI_CMD
Parameters:

      00h  A_UINT16 2   cmd_buf_sz      ;HCI cmd buffer size
      02h  A_UINT8  ..  buf[1]          ;Absolute HCI cmd (see file "hci.h")

WMIevent(1024h) - WMI_HCI_EVENT_EVENT aka WMI_HCI_EVENT
Event Data:

      00h  A_UINT16 2   evt_buf_sz      ;HCI event buffer size
      02h  A_UINT8  ..  buf[1]          ;HCI event (see file "hci.h")

WMIcmd(F024h) - WMI_RX_FRAME_FORMAT_CMD
Parameters:

      00h  A_UINT8  1  metaVersion  ;version of meta data for rx packets
                                    ;(0-7=valid, 0=default)
      01h  A_UINT8  1  dot11Hdr  ;1=leave .11 header intact,
                                 ;0=default/replace .11 header with .3
      02h  A_UINT8  1  defragOnHost  ;1=defragmentation is performed by host,
                                     ;0=performed by target <default>
      03h  A_UINT8  1  reserved[1]     ;alignment

WMIcmd(F025h) - WMI_SET_THIN_MODE_CMD
Parameters:

      00h  A_UINT8  1  enable      ;0=default/normal mode, 1=operate in thin mode
      01h  A_UINT8  3  reserved[3]

WMIcmd(F026h) - WMI_SET_BT_WLAN_CONN_PRECEDENCE_CMD
Parameters:

      00h  A_UINT8  1  precedence;

BT_WLAN_CONN_PRECEDENCE values:

      BT_WLAN_CONN_PRECDENCE_WLAN = 0  ;default
      BT_WLAN_CONN_PRECDENCE_PAL  = 1

Unknown purpose. Maybe related to BT=Bluetooth? CONN=Connect? PAL=What?
WMIcmd(F03Fh) - WMI_CONFIG_TX_MAC_RULES_CMD
Parameters:

      00h  A_UINT32 4  rules  ;combination of WMI_WRT_xxx values (see "wmi_thin.h")

WMIcmd(F040h) - WMI_SET_PROMISCUOUS_MODE_CMD
Parameters:

      00h  A_UINT8  1  enable (0=default/normal mode, 1=promiscuous mode)

WMIcmd(F041h) - WMI_RX_FRAME_FILTER_CMD
Parameters:

      00h  A_UINT16 2  filtermask(0)      ;WMI_FILTERMASK_MGMT
      02h  A_UINT16 2  filtermask(1)      ;WMI_FILTERMASK_CTRL
      04h  A_UINT16 2  filtermask(2)      ;WMI_FILTERMASK_DATA
      06h  A_UINT16 2  reserved           ;alignment

WMIcmd(F042h) - WMI_SET_CHANNEL_CMD
Parameters:

      00h  A_UINT16 2  channel   ;frequency in MHz
      --  //A_UINT8 -  mode      ;outcommented (HT20 or HT40 flag?)
      --  //A_UINT8 -  secondary ;outcommented (HT40 2nd channel above/below flag?)

See also: WMI_SET_CHANNEL_EVENT
WMIevent(9000h) - WMI_SET_CHANNEL_EVENT
Event Data:

      00h  A_UINT8 1  result       ;WMI_SET_CHANNEL_RES (or WMI_THIN_JOIN_RESULT??)
      01h  A_UINT8 3  reserved[3]  ;alignment

WMI_SET_CHANNEL_RES values:

      WMI_SET_CHANNEL_RES_SUCCESS = 0
      WMI_SET_CHANNEL_RES_FAIL    = 1

This is probably the reply to WMI_SET_CHANNEL_CMD (although official comments claim it to be WMI_THIN_JOIN related; probably because of copying/pasting the WMI_THIN_JOIN parameter structure without adjusting the comments).
WMIcmd(F046h) - WMI_SET_DIV_PARAMS_CMD aka WMI_DIV_PARAMS_CMD
Parameters:

      00h  A_UINT32 4  divIdleTime;
      04h  A_UINT8  1  antRssiThresh;
      05h  A_UINT8  1  divEnable;
      06h  A_UINT16 2  active_treshold_rate;

WMIcmd(F028h) - WMI_SET_PMK_CMD
Parameters:

      00h  A_UINT8  20h  pmk[WMI_PMK_LEN];

WMI_PMK_LEN = 32
WMIcmd(F047h) - WMI_GET_PMK_CMD ;reply?
Parameters:

      Unknown (none?)

Reply: See WMI_GET_PMK_EVENT aka WMI_GET_PMK_REPLY
WMIevent(102Ah) - WMI_GET_PMK_EVENT aka WMI_GET_PMK_REPLY
Event Data:

      00h  A_UINT8  20h  pmk[WMI_PMK_LEN];

WMIcmd(F048h) - WMI_SET_PASSPHRASE_CMD
Parameters:

      00h  A_UCHAR  20h  ssid[WMI_MAX_SSID_LEN];
      20h  A_UINT8  40h  passphrase[WMI_PASSPHRASE_LEN];
      60h  A_UINT8  1    ssid_len;
      61h  A_UINT8  1    passphrase_len;

WMI_PASSPHRASE_LEN = 64
WMIcmd(F049h) - WMI_SEND_ASSOC_RES_CMD ;aka WMI_SEND_ASSOCRES_CMD
Parameters:

      00h  A_UINT8 1  host_accept;
      01h  A_UINT8 1  host_reasonCode;
      02h  A_UINT8 1  target_status;
      03h  A_UINT8 6  sta_mac_addr[ATH_MAC_LEN];
      09h  A_UINT8 1  rspType;

WMIcmd(F04Ah) - WMI_SET_ASSOC_REQ_RELAY_CMD ;aka WMI_SET_ASSOCREQ_RELAY
Parameters:

      00h  A_UINT8 1  enable;

WMIevent(9001h) - WMI_ASSOC_REQ_EVENT aka WMI_ASSOCREQ_EVENT
Event Data:

      00h  A_UINT8 1  status;
      01h  A_UINT8 1  rspType;

WMIcmd(F04Bh or F04Dh) - WMI_ACS_CTRL_CMD ;aka WMI_ACS_CTRL_MSG
Parameters:

      00h  A_UINT8 1   ctrl_id;     /* control identifier (aka sub-command?)
      01h  A_UINT8 1   length;      /* number of bytes of data to follow
      02h  A_UINT8 ..  data[1];     /* start of control data

WMI_ACS_CTRL_HDR_LEN = (sizeof(WMI_ACS_CTRL_MSG) - sizeof(A_UINT8))
WMIevent(9002h) - WMI_ACS_EVENT ;generic ACS event
Event Data:

      00h  A_UINT8 1   event_id;    /* event identifier
      01h  A_UINT8 1   length;      /* number of bytes of data that follows
      02h  A_UINT8 ..  data[1];     /* start of event data

WMI_ACS_EVENT_HDR_LEN = (sizeof(WMI_ACS_EVENT_MSG) - sizeof(A_UINT8))
WMIcmd(F04Ch or F052h) - WMI_SET_EXCESS_TX_RETRY_THRES_CMD
Parameters:

      00h  A_UINT32 4  threshold;

WMIcmd(F061h or F051h) - WMI_FORCE_TARGET_ASSERT_CMD
Parameters:

      Unknown (None?)

WMIcmd(F04Dh or N/A) - WMI_SET_TBD_TIME_CMD ;added for wmiconfig cmd for TBD
WMIcmd(F04Eh or N/A) - WMI_PKTLOG_ENABLE_CMD
WMIcmd(F04Fh or N/A) - WMI_PKTLOG_DISABLE_CMD
WMIcmd(F062h or N/A) - WMI_SET_PROBED_SSID_EX_CMD
WMIcmd(F063h or N/A) - WMI_SET_NETWORK_LIST_OFFLOAD_CMD
WMIcmd(F064h or N/A) - WMI_SET_ARP_NS_OFFLOAD_CMD
WMIcmd(F065h or N/A) - WMI_ADD_WOW_EXT_PATTERN_CMD
WMIcmd(F066h or N/A) - WMI_GTK_OFFLOAD_OP_CMD
WMIcmd(F067h or N/A) - WMI_REMAIN_ON_CHNL_CMD
WMIcmd(F068h or N/A) - WMI_CANCEL_REMAIN_ON_CHNL_CMD
WMIcmd(F069h or N/A) - WMI_SEND_ACTION_CMD
WMIcmd(F06Ah or N/A) - WMI_PROBE_REQ_REPORT_CMD
WMIcmd(F06Bh or N/A) - WMI_DISABLE_11B_RATES_CMD
WMIcmd(F06Ch or N/A) - WMI_SEND_PROBE_RESPONSE_CMD
Unknown/undocumented (invented 2012 or so).
WMIevent(?) - WMI_GET_APPIE_CMD ;aka GET_APP_IE ;-not implemented in DSi
The "GET_APP" command name suggests that there should be some reply, but:

      EVENTID is unknown (maybe 0040h, ie. same as GET_APPIE_CMD)
      Reply structure is unknown (maybe same parameter structure for SET_APPIE_CMD)

WMIevent(?) - WMI_CRE_PRIORITY_STREAM_REPLY ;-not implemented in DSi
Unknown crap. The DSi doesn't send a reply to WMI_CREATE_PSTREAM_CMD, nonetheless, existing source code does have a WMI_CRE_PRIORITY_STREAM_REPLY structure for whatever reason, maybe it's send only in certain firmware version(s), with whatever/unknown WMIevent(xxxx) number. The reply structure is:

      00h  A_UINT8  1  status;                 /* PSTREAM_REPLY_STATUS
      01h  A_UINT8  1  txQueueNumber;
      02h  A_UINT8  1  rxQueueNumber;
      03h  A_UINT8  1  trafficClass;
      04h  A_UINT8  1  trafficDirection;       /* DIR_TYPE

PSTREAM_REPLY_STATUS values:

      A_SUCCEEDED = A_OK                   = 0
      A_FAILED_DELETE_STREAM_DOESNOT_EXIST = 250
      A_SUCCEEDED_MODIFY_STREAM            = 251
      A_FAILED_INVALID_STREAM              = 252
      A_FAILED_MAX_THINSTREAMS             = 253
      A_FAILED_CREATE_REMOVE_PSTREAM_FIRST = 254

WMIevent(?) - WMI_DEL_PRIORITY_STREAM_REPLY ;-not implemented in DSi
Unknown crap. See above for details. The WMI_DEL_PRIORITY_STREAM_REPLY structure is:

      00h  A_UINT8  1   status;            ;\
      01h  A_UINT8  1   txQueueNumber;     ; same as WMI_CRE_PRIORITY_STREAM_REPLY
      02h  A_UINT8  1   rxQueueNumber;     ;/
      03h  A_UINT8  1   trafficDirection;  ;\unlike WMI_CRE_PRIORITY_STREAM_REPLY
      04h  A_UINT8  1   trafficClass;      ;/(entries are swapped)

WMIevent(?) - WMI_FRAME_RATES_REPLY ;-not implemented in DSi
Unknown crap. WMI_FRAME_RATES_REPLY is said to have same structure as WMI_SET_FRAMERATES_CMD parameter structure. But WMIevent(?) number is unknown, and DSi doesn't seem to send any such REPLY.
WMIevent(101Bh) - WMI_PEER_NODE_EVENT
Event Data:

      00h  A_UINT8  1  eventCode;
      01h  A_UINT8  6  peerMacAddr[ATH_MAC_LEN];

Below PEER values are probably meant to be the "eventCode" values(?):

      PEER_NODE_JOIN_EVENT       = 00h
      PEER_NODE_LEAVE_EVENT      = 01h
      PEER_FIRST_NODE_JOIN_EVENT = 10h
      PEER_LAST_NODE_LEAVE_EVENT = 11h

WMIevent(101Dh) - WMI_DTIMEXPIRY_EVENT
Event Data:

      Unknown (if any)

WMIevent(101Eh) - WMI_WLAN_VERSION_EVENT
Event Data:

      00h  A_UINT32 4  version;

Whatever event with whatever version?
WMIevent(1023h) - WMI_TX_COMPLETE_EVENT
Event Data:

      00h  A_UINT8  1  numMessages ;number of tx comp msgs following
      01h  A_UINT8  1  msgLen   ;length in bytes for each individual msg following
      02h  A_UINT8  1  msgType  ;version of tx complete msg data following
      03h  A_UINT8  1  reserved
     When msgType=01h=WMI_TXCOMPLETE_VERSION_1
      04h  ...      .. individual message(s) (see TX_COMPLETE_MSG_V1 structure)
     When msgType=Other
      04h  ...      .. reserved for other MSG types (none such defined yet)

TX_COMPLETE_MSG_V1 structure:

      00h  A_UINT8 1   status      /* one of TX_COMPLETE_STATUS_xxx values
      01h  A_UINT8 1   pktID       /* packet ID to identify parent packet
      02h  A_UINT8 1   rateIdx     /* rate index on successful transmission
      03h  A_UINT8 1   ackFailures /* number of ACK failures in tx attempt
           #if 0  ;optional "host delivery time" params currently ommitted...
      --     A_UINT32  queueDelay  /* usec delay measured Tx Start time
      --     A_UINT32  mediaDelay  /* usec delay measured ACK rx time
           #endif

TX_COMPLETE_STATUS_xxx values:

      TX_COMPLETE_STATUS_SUCCESS = 0
      TX_COMPLETE_STATUS_RETRIES = 1
      TX_COMPLETE_STATUS_NOLINK  = 2
      TX_COMPLETE_STATUS_TIMEOUT = 3
      TX_COMPLETE_STATUS_OTHER   = 4

Transmit complete event.
WMIevent(1025h) - WMI_ACL_DATA_EVENT
Event Data:

      Unknown (what?)

ACL is what? Is that somehow related to "ACLCOEX"?
WMIevent(1026h, or formerly N/A, or N/A) - WMI_REPORT_SLEEP_STATE_EVENT
Event Data:

      00h  A_UINT32 4  sleepState;

Values for "sleepState":

      WMI_REPORT_SLEEP_STATUS_IS_DEEP_SLEEP = 0
      WMI_REPORT_SLEEP_STATUS_IS_AWAKE      = 1

Names: WMI_REPORT_SLEEP_STATE_EVENT aka WMI_REPORT_SLEEP_STATUS
WMIevent(1027h, or formerly 1026h, or N/A) - WMI_WAPI_REKEY_EVENT
This event is added/removed randomly in different source code versions.
Event Data:

      00h  A_UINT8  1   type;
      01h  A_UINT8  6   macAddr[ATH_MAC_LEN];

Values (probably for above "type" field?):

      WAPI_REKEY_UCAST = 1
      WAPI_REKEY_MCAST = 2

The numbering for WMIevent(1026h..1029h) does vary in older source versions because WMI_REPORT_SLEEP_STATE_EVENT originally didn't exist, and WMI_WAPI_REKEY_EVENT originally did exist only if "WAPI_ENABLE". Later source code did always include WMI_WAPI_REKEY_EVENT, and even later code did re-remove it completely.
Names: WMI_WAPI_REKEY_EVENT aka WMI_WAPIREKEY_EVENT
WMIevent(1035h) - WMI_CCX_RM_STATUS_EVENT ;CCX Evants, uh, EvAntS?
Event Data:

      00h  A_INT32 4  rm_type   ;\one of these MIGHT be "WMI_CCX_RM_STATUS_TYPE" ?
      04h  A_INT32 4  status    ;/

WMI_CCX_RM_STATUS_TYPE values (probably for the "rm_type" field?):

      WMI_CCX_RM_STATUS_UNKNOWN     = 0
      WMI_CCX_RM_REPORT_SENT        = 1
      WMI_CCX_RM_REFUSE_REPORT_SENT = 2

Uh, "CCX" means... What?
Uh, "RM" means... maybe "radio_measurements" or What?
Maybe this is somehow related to "WMI_ENABLE_RM_CMD"?
WMIevent(1045h) - WMI_SET_HOST_SLEEP_MODE_CMD_PROCESSED_EVENT
Event Data:

      Unknown (if any?)

This event exists ONLY in source code from 2010, not in older code, and it's removed in newer code from 2012.
Special event used to notify host that AR6003 has processed sleep command (aka WMI_SET_HOST_SLEEP_MODE_CMD?) (needed to prevent a late incoming credit report from crashing the system).
WMIevent(9003h) - WMI_REPORT_WMM_PARAMS_EVENT
Event Data:

      00h  wmm_params  6*4  wmm_params[4];

"wmm_params" structure:

      00h  A_UINT8     1    acm;           /* ACM parameter
      01h  A_UINT8     1    aifsn;         /* AIFSN parameters
      02h  A_UINT8     1    logcwmin;      /* cwmin in exponential form
      03h  A_UINT8     1    logcwmax;      /* cwmax in exponential form
      04h  A_UINT16    2    txopLimit;     /* txopLimit

WMIcmd(?) - WMI_SET_ADHOC_BSSID_CMD
Parameters:

      00h  A_UINT8  6   bssid[ATH_MAC_LEN];

The above parameter structure is defined in "wmi.h", but there's no WMIcmd(xxxxh) command ID for it. Maybe the command did exist only in older versions (from dates before 2006)?

DSi Atheros Wifi - Unimplemented WMI Bluetooth Coexistence (newer AR6002)

/*----------------------COMMON to AR6002 and AR6003 -------------------------*/
BT_PARAMS_SCO_PSPOLL_LATENCY values:

      BT_PARAM_SCO_PSPOLL_LATENCY_ONE_FOURTH   = 1     ;aka 25%
      BT_PARAM_SCO_PSPOLL_LATENCY_HALF         = 2     ;aka 50%
      BT_PARAM_SCO_PSPOLL_LATENCY_THREE_FOURTH = 3     ;aka 75%

BT_PARAMS_SCO_STOMP_RULES values:

      BT_PARAMS_SCO_STOMP_SCO_NEVER      = 1
      BT_PARAMS_SCO_STOMP_SCO_ALWAYS     = 2
      BT_PARAMS_SCO_STOMP_SCO_IN_LOWRSSI = 3

BT_ANT_FRONTEND_CONFIG values:

      BT_ANT_TYPE_UNDEF         = 0   ;aka "Disabled (default)"
      BT_ANT_TYPE_DUAL          = 1
      BT_ANT_TYPE_SPLITTER      = 2
      BT_ANT_TYPE_SWITCH        = 3
      BT_ANT_TYPE_HIGH_ISO_DUAL = 4    ;<-- not in "code aurora"

BT_COLOCATED_DEV_TYPE values:

      BT_COLOCATED_DEV_BTS4020  = 0
      BT_COLCATED_DEV_CSR       = 1
      BT_COLOCATED_DEV_VALKYRIE = 2   ;aka BT_COLOCATED_DEV_VALKYRIe

/*********************** Applicable to AR6002 ONLY ***************************/
WMIcmd(003Bh) - WMI_SET_BT_STATUS_CMD ;AR6002 Bluetooth Coexistence only?
Parameters (02h bytes):

      00h  A_UINT8  1   streamType;         ;aka BT_STREAM_TYPE ?
      01h  A_UINT8  1   status;             ;aka BT_STREAM_STATUS ?

BT_STREAM_TYPE values:

      BT_STREAM_UNDEF = 0
      BT_STREAM_SCO   = 1 ;SCO stream
      BT_STREAM_A2DP  = 2 ;A2DP stream
      BT_STREAM_SCAN  = 3 ;BT Discovery or Page ;\"Newer AR6002 from 2008-2010"
      BT_STREAM_ESCO  = 4 ;Whatever             ;/
      BT_STREAM_ALL   = 5 ;Whatever             ;-"Newer AR6002 from 2008 only"

BT_STREAM_STATUS values:

      BT_STATUS_UNDEF        = 0
      BT_STATUS_START        = 1  ;-renamed to BT_STATUS_ON in code from 2010
      BT_STATUS_STOP         = 2  ;-renamed to BT_STATUS_OFF in code from 2010
      BT_STATUS_RESUME       = 3  ;\defined in "Older/Newer AR6002 from 2008"
      BT_STATUS_SUSPEND      = 4  ;/(not in "Newer AR6002 for 2010")
      BT_STATUS_SUSPEND_A2DP = 5  ;\defined in "Newer AR6002 from 2008")
      BT_STATUS_SUSPEND_SCO  = 6  ; (not in "Older AR6002 for 2008")
      BT_STATUS_SUSPEND_ACL  = 7  ; (not in "Newer AR6002 for 2010")
      BT_STATUS_SUSPEND_SCAN = 8  ;/

AR6002 only? (although other comment says "COMMON to AR6002 and AR6003"?)
WMIcmd(003Ch) - WMI_SET_BT_PARAMS_CMD ;AR6002 Bluetooth Coexistence only?
Parameters (1Fh or 19h bytes, for "Newer AR6002" code from 2008 or 2010):

      1Fh 19h  <--- total size (1Fh for code from 2008, 19h for code from 2010)
     when paramType=1=BT_PARAM_SCO:  ;SCO stream parameters (BT_PARAMS_SCO)
      00h 00h A_UINT32 4  numScoCyclesForceTrigger (Number SCO cycles after which
                           force a pspoll, default=10)
      04h 04h A_UINT32 4  dataResponseTimeout (Timeout Waiting for Downlink pkt in
                           response for ps-poll, default=10 ms)
      08h 08h A_UINT32 4  stompScoRules    ;aka BT_PARAMS_SCO_STOMP_RULES ?
      0Ch 0Ch A_UINT32 4  scoOptFlags (SCO Options Flags)
      10h --  A_UINT32 4  p2lrpOptModeBound     ;\PacketToLowRatePacketRatio's
      14h --  A_UINT32 4  p2lrpNonOptModeBound  ;/
      18h 10h A_UINT8  1  stompDutyCyleVal (SCO cycles to limit ps-poll queuing
                           if stomped)
      19h 11h A_UINT8  1  stompDutyCyleMaxVal (firmware increases stomp duty cycle
                           gradually uptill this value on need basis)
      1Ah 12h A_UINT8  1  psPollLatencyFraction (Fraction of idle period, within
                           which additional ps-polls can be queued)
      1Bh 13h A_UINT8  1  noSCOSlots (Number of SCO Tx/Rx slots. HVx,EV3,2EV3=2)
      1Ch 14h A_UINT8  1  noIdleSlots (Number of Bluetooth idle slots between
                           consecutive SCO Tx/Rx slots. HVx,EV3=4, 2EV3=10)
      1Dh --  A_UINT8  1  reserved8 (maintain word algnment) (uh, really?)
      --  15h A_UINT8  1  scoOptOffRssi (RSSI value below which we go to ps poll)
      --  16h A_UINT8  1  scoOptOnRssi (RSSI value above which we reenter opt mode)
      --  17h A_UINT8  1  scoOptRtsCount
     when paramType=2=BT_PARAM_A2DP: ;whatever (BT_PARAMS_A2DP)
      00h 00h A_UINT32 4  a2dpWlanUsageLimit (MAX time firmware uses the medium for
                           wlan, after it identifies the idle time, default=30 ms)
      04h 04h A_UINT32 4  a2dpBurstCntMin (Minimum number of bluetooth data frames
                           to replenish Wlan Usage limit, default 3)
      08h 08h A_UINT32 4  a2dpDataRespTimeout
      0Ch 0Ch A_UINT32 4  a2dpOptFlags (A2DP Option flags)
      10h --  A_UINT32 4  p2lrpOptModeBound     ;\PacketToLowRatePacketRatio's
      14h --  A_UINT32 4  p2lrpNonOptModeBound  ;/
      18h --  A_UINT16 2  reserved16 (maintain word alignment)
      1Ah 10h A_UINT8  1  isCoLocatedBtRoleMaster
      1Bh --  A_UINT8  1  reserved8 (maintain word alignment)
      1Ch --  PAD      2  undefined/padding
      --  11h A_UINT8  1  a2dpOptOffRssi (RSSI value below which we go to ps poll)
      --  12h A_UINT8  1  a2dpOptOnRssi(RSSI value above which we reenter opt mode)
      --  13h A_UINT8  1  a2dpOptRtsCount
      --  14h PAD      4  undefined/padding
     when paramType=3=BT_PARAM_ANTENNA_CONFIG:
      00h 00h A_UINT8  1   antType          aka BT_ANT_FRONTEND_CONFIG
      01h --  PAD      1Dh undefined/padding
      --  01h PAD      17h undefined/padding
     when paramType=4=BT_PARAM_COLOCATED_BT_DEVICE:
      00h 00h A_UINT8  1   coLocatedBtDev   aka BT_COLOCATED_DEV_TYPE
      01h --  PAD      1Dh undefined/padding
      --  01h PAD      17h undefined/padding
     when paramType=5=BT_PARAM_ACLCOEX: ;whatever (BT_PARAMS_ACLCOEX)
      ;During BT ftp/ BT OPP or any another data based acl profile on bluetooth
      ;(non a2dp).
      00h 00h A_UINT32 4   aclWlanMediumUsageTime (Wlan usage time during
                            Acl (non-a2dp) coexistence, default=30 ms)
      04h 04h A_UINT32 4   aclBtMediumUsageTime (Bt usage time during
                            acl coexistence, default=30 ms)
      08h 08h A_UINT32 4   aclDataRespTimeout
      0Ch 0Ch A_UINT32 4   aclDetectTimeout (ACL coexistence enabled if we get
                            10 Pkts in X ms, default=100 ms)
      10h 10h A_UINT32 4   aclmaxPktCnt (No of ACL pkts to receive before
                            enabling ACL coex)
      14h --  PAD      0Ah undefined/padding
      --  14h PAD      4   undefined/padding
     when paramType=6=BT_PARAM_11A_SEPARATE_ANT:
      00h 00h UNKNOWN  ?   unknown (maybe same as antType ?)
      xxh --  PAD      ..  undefined/padding
      --  xxh PAD      ..  undefined/padding
     and, in all cases:
      1Eh 18h A_UINT8  1   paramType

Values for "scoOptFlags" and "a2dpOptFlags":

      Bit0       Allow Close Range Optimization             ;\all versions
      Bit1       Force awake during close range             ;/
      Bit2       If set use (host supplied) threshold       ;\Newer AR6002
      Bit3..23   Unused                                     ;/from 2008
      Bit2       If set use host supplied RSSI for OPT      ;\
      Bit3       If set use host supplied RTS COUNT for OPT ; Newer AR6002
      Bit4..7    Unused                                     ; from 2010
      Bit8..15   Low Data Rate Min Cnt                      ;
      Bit16..23  Low Data Rate Max Cnt                      ;/
      Bit24..31  Undocumented (unused?)                     ;-all versions

PacketToLowRatePacketRatio's (p2lrp) entries (in code from 2008 only):

      p2lrpOptModeBound:    Minimum ratio required to STAY IN opt mode
      p2lrpNonOptModeBound: Minimum ratio required to SWITCH TO opt mode

DSi Atheros Wifi - Unimplemented WMI Bluetooth Coexistence (AR6003)

WMIcmd(003Bh) - WMI_SET_BT_STATUS_CMD ;AR6002 Bluetooth Coexistence only?
This command does maybe exist for AR6003 too (conflicting comments claim that it is for AR6002 only, or for both AR6002 and AR6003). See "Newer AR6002" description for details.
Also possible that it's replaced by "WMI_SET_BTCOEX_BT_OPERATING_STATUS_CMD".
WMIcmd(003Ch) - WMI_SET_BT_PARAMS_CMD ;AR6002 Bluetooth Coexistence only?
This command is used for AR6002 only. On AR6003, it's replaced by the new commands described below:
WMIcmd(F02Ah) - WMI_SET_BTCOEX_FE_ANT_CMD
Parameters:

      00h  A_UINT8  1  btcoexFeAntType
                        1 - WMI_BTCOEX_FE_ANT_SINGLE for single antenna front end
                        2 - WMI_BTCOEX_FE_ANT_DUAL for dual antenna front end
                            (for isolations less 35dB, for higher isolation there
                            is not need to pass this command).
                            (not implemented)

WMI_BTCOEX_FE_ANT_TYPE values:

      WMI_BTCOEX_NOT_ENABLED          = 0
      WMI_BTCOEX_FE_ANT_SINGLE        = 1
      WMI_BTCOEX_FE_ANT_DUAL          = 2
      WMI_BTCOEX_FE_ANT_DUAL_HIGH_ISO = 3
      WMI_BTCOEX_FE_ANT_BYPASS_MODE   = 4
      WMI_BTCOEX_FE_ANT_COMBINE_MODE  = 5

Indicates front end antenna configuration. This command needs to be issued right after initialization and after WMI_SET_BTCOEX_COLOCATED_BT_DEV_CMD. AR6003 enables coexistence and antenna switching based on the configuration.
WMIcmd(F02Bh) - WMI_SET_BTCOEX_COLOCATED_BT_DEV_CMD
Parameters:

      00h  A_UINT8  1  btcoexCoLocatedBTdev;   1 - Qcom BT (3 -wire PTA)
                                               2 - CSR BT  (3 wire PTA)
                                               3 - Atheros 3001 BT (3 wire PTA)
                                               4 - STE bluetooth (4-wire ePTA)
                                               5 - Atheros 3002 BT (4-wire MCI)
                                               default=3 (Atheros 3001 BT )

Indicate the bluetooth chip to the firmware. Firmware can have different algorithm based bluetooth chip type. Based on bluetooth device, different coexistence protocol would be used.
WMIcmd(F02Ch) - WMI_SET_BTCOEX_SCO_CONFIG_CMD
Parameters:

      --------------- BTCOEX_SCO_CONFIG scoConfig;
      00h  A_UINT32 4  scoSlots (Number of SCO Tx/Rx slots: HVx,EV3,2EV3 = 2)
      04h  A_UINT32 4  scoIdleSlots (Number of Bluetooth idle slots between
                        consecutive SCO Tx/Rx slots: HVx,EV3 = 4, 2EV3 = 10)
      08h  A_UINT32 4  scoFlags;  SCO Options Flags:
                                  Bit0   Allow Close Range Optimization
                                  Bit1   Is EDR capable or Not
                                  Bit2   IS Co-located Bt role Master
                                  Bit3   Firmware determines the periodicity of SCO
      0Ch  A_UINT32 4  linkId (applicable to STE-BT - not used)
      --------------- BTCOEX_PSPOLLMODE_SCO_CONFIG scoPspollConfig;
      10h  A_UINT32 4  scoCyclesForceTrigger (Number SCO cycles after which
                        force a pspoll, default=10)
      14h  A_UINT32 4  scoDataResponseTimeout (Timeout Waiting for Downlink pkt
                        in response for ps-poll, default=20 ms)
      18h  A_UINT32 4  scoStompDutyCyleVal (not implemented)
      1Ch  A_UINT32 4  scoStompDutyCyleMaxVal (not implemented)
      20h  A_UINT32 4  scoPsPollLatencyFraction (Fraction of idle period, within
                        which additional ps-polls can be queued
                          1 - 1/4 of idle duration
                          2 - 1/2 of idle duration
                          3 - 3/4 of idle duration
                          default=2 (1/2)
      --------------- BTCOEX_OPTMODE_SCO_CONFIG scoOptModeConfig;
      24h  A_UINT32 4  scoStompCntIn100ms (max number of SCO stomp in 100ms
                        allowed in opt mode. If exceeds the configured value,
                        switch to ps-poll mode, default=3)
      28h  A_UINT32 4  scoContStompMax (max number of continous stomp allowed in
                        opt mode. if excedded switch to pspoll mode, default=3)
      2Ch  A_UINT32 4  scoMinlowRateMbps (Low rate threshold)

      30h  A_UINT32 4  scoLowRateCnt (number of low rate pkts (< scoMinlowRateMbps)
                        allowed in 100 ms. If exceeded switch/stay to ps-poll mode,
                        lower stay in opt mode, default=36)
      34h  A_UINT32 4  scoHighPktRatio "(Total Rx pkts in 100 ms + 1)/((Total tx
                        pkts in 100 ms - No of high rate pkts in 100 ms) + 1) in
                        100 ms"
                        if exceeded switch/stay in opt mode and if lower
                        switch/stay in pspoll mode.
                        default=5 (80% of high rates)
      38h  A_UINT32 4  scoMaxAggrSize (Max number of Rx subframes allowed in this
                        mode. (Firmware re-negogiates max number of aggregates if
                        it was negogiated to higher value, default=1,
                        Recommended value Basic rate headsets = 1, EDR (2-EV3) =4.
      --------------- BTCOEX_WLANSCAN_SCO_CONFIG scoWlanScanConfig;
      3Ch  A_UINT32 4  scanInterval;
      40h  A_UINT32 4  maxScanStompCnt;

Configure SCO parameters. These parameters would be used whenever firmware is indicated of (e)SCO profile on bluetooth (via WMI_SET_BTCOEX_BT_OPERATING_STATUS_CMD).
Configration of BTCOEX_SCO_CONFIG data structure are common configuration and applies ps-poll mode and opt mode.
Ps-poll Mode - Station is in power-save and retrieves downlink data between sco gaps.
Opt Mode - station is in awake state and access point can send data to station any time.
BTCOEX_PSPOLLMODE_SCO_CONFIG - Configuration applied only during ps-poll mode.
BTCOEX_OPTMODE_SCO_CONFIG - Configuration applied only during opt mode.

      Aliases for "scoFlags":
      #define WMI_SCO_CONFIG_FLAG_ALLOW_OPTIMIZATION   (1 << 0)
      #define WMI_SCO_CONFIG_FLAG_IS_EDR_CAPABLE       (1 << 1)
      #define WMI_SCO_CONFIG_FLAG_IS_BT_MASTER         (1 << 2)
      #define WMI_SCO_CONFIG_FLAG_FW_DETECT_OF_PER     (1 << 3)

WMIcmd(F02Dh) - WMI_SET_BTCOEX_A2DP_CONFIG_CMD
Parameters:

      --------------- BTCOEX_A2DP_CONFIG a2dpConfig;
      00h  A_UINT32 4  a2dpFlags;  2DP Option flags:
                                    Bit0   Allow Close Range Optimization
                                    Bit1   IS EDR capable
                                    Bit2   IS Co-located Bt role Master
                                    Bit3   a2dp traffic is high priority
                                    Bit4   Fw detect the role of bluetooth.
      04h  A_UINT32 4  linkId (Applicable only to STE-BT - not used)
      --------------- BTCOEX_PSPOLLMODE_A2DP_CONFIG a2dppspollConfig;
      08h  A_UINT32 4  a2dpWlanMaxDur (MAX time firmware uses the medium for
                        wlan, after it identifies the idle time, default=30 ms)
      0Ch  A_UINT32 4  a2dpMinBurstCnt (Minimum number of bluetooth data frames
                        to replenish Wlan Usage limit, default=3)
      10h  A_UINT32 4  a2dpDataRespTimeout (Max duration firmware waits for
                        downlink by stomping on  bluetooth after ps-poll is
                        acknowledged, default=20 ms)
      --------------- BTCOEX_OPTMODE_A2DP_CONFIG a2dpOptConfig;
      14h  A_UINT32 4  a2dpMinlowRateMbps (Low rate threshold)
      18h  A_UINT32 4  a2dpLowRateCnt (number of low rate pkts
                        (<a2dpMinlowRateMbps) allowed in 100 ms.
                        If exceeded switch/stay to ps-poll mode, lower stay in
                        opt mode, default=36)
      1Ch  A_UINT32 4  a2dpHighPktRatio "(Total Rx pkts in 100 ms + 1)/
                        ((Total tx pkts in 100 ms - No of high rate pkts in 100 ms)
                        + 1) in 100 ms",    if exceeded switch/stay in opt mode and
                        if lower switch/stay in pspoll mode.
                        default=5 (80% of high rates)
      20h  A_UINT32 4  a2dpMaxAggrSize (Max number of Rx subframes allowed in this
                        mode. (Firmware re-negogiates max number of aggregates if
                        it was negogiated to higher value, default=1.
                        Recommended value Basic rate headsets = 1, EDR (2-EV3) =8)
      24h  A_UINT32 4  a2dpPktStompCnt (number of a2dp pkts that can be stomped
                        per burst, default=6)

Configure A2DP profile parameters. These parameters would be used whenver firmware is indicated of A2DP profile on bluetooth (via WMI_SET_BTCOEX_BT_OPERATING_STATUS_CMD).
Configuration of BTCOEX_A2DP_CONFIG data structure are common configuration and applies to ps-poll mode and opt mode.
Ps-poll Mode - Station is in power-save and retrieves downlink data between a2dp data bursts.
Opt Mode - station is in power save during a2dp bursts and awake in the gaps.
BTCOEX_PSPOLLMODE_A2DP_CONFIG - Configuration applied only during ps-poll mode.
BTCOEX_OPTMODE_A2DP_CONFIG - Configuration applied only during opt mode.

      Aliases for "a2dpFlags":
      #define WMI_A2DP_CONFIG_FLAG_ALLOW_OPTIMIZATION    (1 << 0)
      #define WMI_A2DP_CONFIG_FLAG_IS_EDR_CAPABLE        (1 << 1)
      #define WMI_A2DP_CONFIG_FLAG_IS_BT_ROLE_MASTER     (1 << 2)
      #define WMI_A2DP_CONFIG_FLAG_IS_A2DP_HIGH_PRI      (1 << 3)
      #define WMI_A2DP_CONFIG_FLAG_FIND_BT_ROLE          (1 << 4)

WMIcmd(F02Eh) - WMI_SET_BTCOEX_ACLCOEX_CONFIG_CMD
Parameters:

      --------------- BTCOEX_ACLCOEX_CONFIG aclCoexConfig;
      00h A_UINT32 4  aclWlanMediumDur (Wlan usage time during Acl (non-a2dp)
                       coexistence, default=30 ms)
      04h A_UINT32 4  aclBtMediumDur (Bt usage time during acl coexistence,
                       default=30 ms)
      08h A_UINT32 4  aclDetectTimeout (BT activity observation time limit.
                       In this time duration, number of bt pkts are counted.
                       If the Cnt reaches "aclPktCntLowerLimit" value for
                       "aclIterToEnableCoex" iteration continuously, firmware gets
                       into ACL coexistence mode. Similarly, if bt traffic count
                       during ACL coexistence has not reached "aclPktCntLowerLimit"
                       continuously for "aclIterToEnableCoex", then ACL coexistence
                       is disabled, default=100 ms)
      0Ch A_UINT32 4  aclPktCntLowerLimit (Acl Pkt Cnt to be received in duration
                       of "aclDetectTimeout" for "aclIterForEnDis" times to
                       enabling ACL coex. Similar logic is used to disable acl
                       coexistence. (If "aclPktCntLowerLimit" cnt of acl pkts
                       are not seen by the for "aclIterForEnDis" then acl
                       coexistence is disabled), default=10)
      10h  A_UINT32 4  aclIterForEnDis (number of Iteration of
                        "aclPktCntLowerLimit" for Enabling and Disabling Acl
                        Coexistence, default=3)
      14h A_UINT32 4  aclPktCntUpperLimit (This is upperBound limit, if there is
                        more than "aclPktCntUpperLimit" seen in "aclDetectTimeout",
                        ACL coexistence is enabled right away, default=15)
      18h A_UINT32 4  aclCoexFlags   A2DP Option flags:
                                     Bit0  Allow Close Range Optimization
                                     Bit1  disable Firmware detection
                           (Currently supported configuration is aclCoexFlags=0)
      1Ch A_UINT32 4  linkId;           ;Applicable only for STE-BT - not used
      --------------- BTCOEX_PSPOLLMODE_ACLCOEX_CONFIG aclCoexPspollConfig;
      20h  A_UINT32 4  aclDataRespTimeout (Max duration firmware waits for downlink
                        by stomping on bluetooth after ps-poll is acknowledged,
                        default=20 ms)
      --------------- BTCOEX_OPTMODE_ACLCOEX_CONFIG aclCoexOptConfig;
      24h  A_UINT32 4  aclCoexMinlowRateMbps        ;\
      28h  A_UINT32 4  aclCoexLowRateCnt            ;
      2Ch  A_UINT32 4  aclCoexHighPktRatio          ; Not implemented yet
      30h  A_UINT32 4  aclCoexMaxAggrSize           ;
      34h  A_UINT32 4  aclPktStompCnt               ;/

Configure non-A2dp ACL profile parameters.The starts of ACL profile can either be indicated via WMI_SET_BTCOEX_BT_OPERATING_STATUS_CMD or enabled via firmware detection which is configured via "aclCoexFlags".
Configration of BTCOEX_ACLCOEX_CONFIG data structure are common configuration and applies ps-poll mode and opt mode.
Ps-poll Mode - Station is in power-save and retrieves downlink data during wlan medium.
Opt Mode - station is in power save during bluetooth medium time and awake during wlan duration.

                 (Not implemented yet)    (uh, what?)

BTCOEX_PSPOLLMODE_ACLCOEX_CONFIG - Configuration applied only during ps-poll mode.
BTCOEX_OPTMODE_ACLCOEX_CONFIG - Configuration applied only during opt mode.

      Aliases for "aclCoexFlags":
      #define WMI_ACLCOEX_FLAGS_ALLOW_OPTIMIZATION   (1 << 0)
      #define WMI_ACLCOEX_FLAGS_DISABLE_FW_DETECTION (1 << 1)

WMIcmd(F02Fh) - WMI_SET_BTCOEX_BTINQUIRY_PAGE_CONFIG_CMD
Parameters:

      00h  A_UINT32 4  btInquiryDataFetchFrequency (The frequency of querying the
                        AP for data (via pspoll) is configured by this parameter,
                        default=10 ms)
      04h  A_UINT32 4  protectBmissDurPostBtInquiry (The firmware will continue to
                        be in inquiry state for configured duration, after inquiry
                        completion. This is to ensure other bluetooth transactions
                        (RDP, SDP profiles, link key exchange, etc.) goes through
                        smoothly without wifi stomping, default=10 secs)
      08h  A_UINT32 4  maxpageStomp (Applicable only for STE-BT interface.
                        Currently not used)
      0Ch  A_UINT32 4  btInquiryPageFlag (Not used)

Configuration parameters during bluetooth inquiry and page. Page configuration is applicable only on interfaces which can distinguish page (applicable only for ePTA - STE bluetooth).
Bluetooth inquiry start and end is indicated via WMI_SET_BTCOEX_BT_OPERATING_STATUS_CMD. During this the station will be power-save mode.
WMIcmd(F030h) - WMI_SET_BTCOEX_DEBUG_CMD
Parameters:

      00h  A_UINT32 4  btcoexDbgParam1      ;\
      04h  A_UINT32 4  btcoexDbgParam2      ; Used for firmware development
      08h  A_UINT32 4  btcoexDbgParam3      ; and debugging
      0Ch  A_UINT32 4  btcoexDbgParam4      ;
      10h  A_UINT32 4  btcoexDbgParam5      ;/

WMIcmd(F031h) - WMI_SET_BTCOEX_BT_OPERATING_STATUS_CMD
Parameters:

      00h  A_UINT32 4  btProfileType (1=SCO, 2=A2DP, 3=INQUIRY_PAGE, 4=ACLCOEX)
      04h  A_UINT32 4  btOperatingStatus    ;aka BT_STREAM_STATUS on AR6002 ?
      08h  A_UINT32 4  btLinkId

WMI_BTCOEX_BT_PROFILE values:

      WMI_BTCOEX_BT_PROFILE_SCO          = 1
      WMI_BTCOEX_BT_PROFILE_A2DP         = 2
      WMI_BTCOEX_BT_PROFILE_INQUIRY_PAGE = 3
      WMI_BTCOEX_BT_PROFILE_ACLCOEX      = 4

This command is probably equivalent to WMI_SET_BT_STATUS_CMD on AR6002.
WMIcmd(F032h) - WMI_GET_BTCOEX_STATS_CMD ;reply WMI_REPORT_BTCOEX_STATS_EVENT
Parameters:

      Unknown (none?)

WMIcmd(F033h) - WMI_GET_BTCOEX_CONFIG_CMD ;reply WMI_REPORT_BTCOEX_CONFIG_EV.
Parameters:

      00h  A_UINT32 4  btProfileType (1=SCO, 2=A2DP, 3=INQUIRY_PAGE, 4=ACLCOEX)
      04h  A_UINT32 4  linkId (not used) (reserved/dummy?)

Command to firmware to get configuration parameters of the bt profile reported via WMI_BTCOEX_CONFIG_EVENTID.
WMIevent(1029h, or formerly 1028h, or 1027h) - WMI_REPORT_BTCOEX_CONFIG_EVENT
Event Data:

      00h A_UINT32 4  btProfileType (1=SCO, 2=A2DP, 3=INQUIRY_PAGE, 4=ACLCOEX)
      04h A_UINT32 4  linkId (not used)
          PREPACK union -- below are same as parameters from corresponding CMD's:
      08h ..  WMI_SET_BTCOEX_SCO_CONFIG_CMD            scoConfigCmd;
      08h ..  WMI_SET_BTCOEX_A2DP_CONFIG_CMD           a2dpConfigCmd;
      08h ..  WMI_SET_BTCOEX_ACLCOEX_CONFIG_CMD        aclcoexConfig;
      08h ..  WMI_SET_BTCOEX_BTINQUIRY_PAGE_CONFIG_CMD btinquiryPageConfigCmd;

Event from firmware to host, sent in response to WMI_GET_BTCOEX_CONFIG_CMD.
WMIevent(1028h, or formerly 1027h, or 1026h) - WMI_REPORT_BTCOEX_STATS_EVENT
Event Data:

      ---------------  BTCOEX_GENERAL_STATS coexStats;
      00h A_UINT32 4  highRatePktCnt;
      04h A_UINT32 4  firstBmissCnt;
      08h A_UINT32 4  psPollFailureCnt;
      0Ch A_UINT32 4  nullFrameFailureCnt;
      10h A_UINT32 4  optModeTransitionCnt;
      ---------------  BTCOEX_SCO_STATS scoStats;
      14h A_UINT32 4  scoStompCntAvg;
      18h A_UINT32 4  scoStompIn100ms;
      1Ch A_UINT32 4  scoMaxContStomp;
      20h A_UINT32 4  scoAvgNoRetries;
      24h A_UINT32 4  scoMaxNoRetriesIn100ms;
      ---------------  BTCOEX_A2DP_STATS a2dpStats;
      28h A_UINT32 4  a2dpBurstCnt;
      2Ch A_UINT32 4  a2dpMaxBurstCnt;
      30h A_UINT32 4  a2dpAvgIdletimeIn100ms;
      34h A_UINT32 4  a2dpAvgStompCnt;
      ---------------  BTCOEX_ACLCOEX_STATS aclCoexStats;
      38h A_UINT32 4  aclPktCntInBtTime;
      3Ch A_UINT32 4  aclStompCntInWlanTime;
      40h A_UINT32 4  aclPktCntIn100ms;

Used for firmware development and debugging.
Names: WMI_GET_BTCOEX_STATS aka WMI_REPORT_BTCOEX_STATS_EVENT aka WMI_REPORT_BTCOEX_BTCOEX_STATS_EVENT

DSi Atheros Wifi - Unimplemented WMI DataSet Functions

Not implemented in DSi.
The "DataSet" feature allows the firmware to read external data from host memory for whatever purpose (maybe intended for cases where the wifi board doesn't contain an EEPROM, or for cases where Xtensa RAM/ROM is too small to hold the whole firmware, or just to make it easier to modify data for testing/debugging).
For the "DataSet" stuff, the normal Command/Response flow is reversed: the firmware does send an EVENT to request data, and the host must respond by a REPLY_CMD (except for the CLOSE_EVENT, which requires no reply).
WMIevent(1010h:3001h) - WMIX_DSETOPENREQ_EVENT

      00h  A_UINT32 4   dset_id          ;-ID of requested DataSet (see "dsetid.h")
      04h  A_UINT32 4   targ_dset_handle ;\to be echo'ed in REPLY_CMD
      08h  A_UINT32 4   targ_reply_fn    ; (host doesn't need to deal with this)
      0Ch  A_UINT32 4   targ_reply_arg   ;/

DataSet Open Request Event. The host should open the DataSet and send a WMIX_DSETOPEN_REPLY_CMD.
WMIevent(1010h:3003h) - WMIX_DSETDATAREQ_EVENT

      00h  A_UINT32 4   access_cookie    ;-some kind of "filehandle" on host side
      04h  A_UINT32 4   offset           ;\source offset & length of requested data
      08h  A_UINT32 4   length           ;/
      0Ch  A_UINT32 4   targ_buf         ;\to be echo'ed in REPLY_CMD
      10h  A_UINT32 4   targ_reply_fn    ; (host doesn't need to deal with this)
      14h  A_UINT32 4   targ_reply_arg   ;/

DataSet Data Request Event. The host should send the requested data via WMIX_DSETDATA_REPLY_CMD.
WMIevent(1010h:3002h) - WMIX_DSETCLOSE_EVENT

      00h  A_UINT32 4   access_cookie       ;-some kind of "filehandle" on host side

DataSet Close Event. The host should close the DataSet (and doesn't need to send any REPLY_CMD).
WMIcmd(002Eh:2001h) - WMIX_DSETOPEN_REPLY_CMD

      00h  A_UINT32 4   status            ;-what status ?
      04h  A_UINT32 4   targ_dset_handle  ;\
      08h  A_UINT32 4   targ_reply_fn     ; to be echo'ed from open EVENT
      0Ch  A_UINT32 4   targ_reply_arg    ;/
      10h  A_UINT32 4   access_cookie     ;-some kind of "filehandle" on host side
      14h  A_UINT32 4   size              ;-what size ?
      18h  A_UINT32 4   version           ;-what version ?

This REPLY_CMD should be send in response to WMIX_DSETOPENREQ_EVENTs.
WMIcmd(002Eh:2002h) - WMIX_DSETDATA_REPLY_CMD

      00h  A_UINT32 4   status            ;-what status ?
      04h  A_UINT32 4   targ_buf          ;\
      08h  A_UINT32 4   targ_reply_fn     ; to be echo'ed from data EVENT
      0Ch  A_UINT32 4   targ_reply_arg    ;/
      10h  A_UINT32 4   length            ;\requested data
      14h  A_UINT8  LEN buf[length]       ;/

This REPLY_CMD should be send in response to WMIX_DSETDATAREQ_EVENTs.

DSi Atheros Wifi - Unimplemented WMI AP Mode Functions (exists on 3DS)

AP Mode
Whatever that is... probably something where the AR600x acts as Access Point (AP) for other Stations (STA).
The DSi doesn't support AP Mode stuff, however, 3DS firmware type4 does support most of them (but with F00Ah..F013h renumbered to 004Ah..0052h).
AP Mode definitions
Changing the following values needs compilation of both driver and firmware.

      AP_MAX_NUM_STA = 4   ;for old AR6002_REV2 version
      AP_MAX_NUM_STA = 10  ;for newer versions
      NUM_DEV        = 3   ;Maximum no. of virtual interface supported
      NUM_CONN       = (AP_MAX_NUM_STA + NUM_DEV)
      AP_ACL_SIZE         = 10
      IEEE80211_MAX_IE    = 256
      MCAST_AID           = 0FFh   ;Spl. AID used to set DTIM flag in the beacons
      DEF_AP_COUNTRY_CODE = "US "
      DEF_AP_WMODE_G      = WMI_11G_MODE
      DEF_AP_WMODE_AG     = WMI_11AG_MODE
      DEF_AP_DTIM         = 5
      DEF_BEACON_INTERVAL = 100
      AP_DISCONNECT_STA_LEFT     = 101  ;\
      AP_DISCONNECT_FROM_HOST    = 102  ;
      AP_DISCONNECT_COMM_TIMEOUT = 103  ; AP mode disconnect reasons
      AP_DISCONNECT_MAX_STA      = 104  ; (101..107 decimal):
      AP_DISCONNECT_ACL          = 105  ;
      AP_DISCONNECT_STA_ROAM     = 106  ;
      AP_DISCONNECT_DFS_CHANNEL  = 107  ;/

WMIcmd(F00Bh or 004Ah) - WMI_AP_HIDDEN_SSID_CMD
Parameters:

      00h  A_UINT8  1   hidden_ssid;

#define HIDDEN_SSID_FALSE = 0
#define HIDDEN_SSID_TRUE = 1
WMIcmd(F00Ch or 004Bh) - WMI_AP_SET_NUM_STA_CMD aka WMI_AP_NUM_STA_CMD
Parameters:

      00h  A_UINT8  1   num_sta;

WMIcmd(F00Dh or 004Ch) - WMI_AP_ACL_POLICY_CMD
Parameters:

      00h  A_UINT8  1   policy;
     #define AP_ACL_DISABLE          = 00h
     #define AP_ACL_ALLOW_MAC        = 01h
     #define AP_ACL_DENY_MAC         = 02h
     #define AP_ACL_RETAIN_LIST_MASK = 80h

WMIcmd(F00Eh or 004Dh) - WMI_AP_ACL_MAC_LIST_CMD aka WMI_AP_ACL_MAC_CMD
Parameters:

      00h  A_UINT8  1   action;
      01h  A_UINT8  1   index;
      02h  A_UINT8  6   mac[ATH_MAC_LEN];
      08h  A_UINT8  1   wildcard;

ADD_MAC_ADDR = 1
DEL_MAC_ADDR = 2
There is also a "WMI_AP_ACL" structure with unknown purpose (maybe internally used in Xtensa memory or whatever):

      A_UINT16 2   index;
      A_UINT8  ... acl_mac[AP_ACL_SIZE][ATH_MAC_LEN];
      A_UINT8  ..  wildcard[AP_ACL_SIZE];
      A_UINT8  1   policy;

WMIcmd(F00Fh or 004Eh) - WMI_AP_CONFIG_COMMIT_CMD
Unknown/undocumented? Except, see this:
sp.chip1stop.com/sp/wp-content/uploads/2015/05/gt202wifimoduleapiguidev13.pdf
Parameters: 34h bytes on 3DS.
Command Parameters: WMI_AP_CONFIG_COMMIT_CMD

      Type Name Comment
      00h  A_UINT8 networktype NETWORK_TYPE
             0x01 INFRA_NETWORK
             0x02 ADHOC_NETWORK
             0x04 ADHOC_CREATOR
      01h  A_UINT8 dot11authmode DOT11_AUTH_MODE
             0x01 OPEN_AUTH
             0x02 SHARED_AUTH
      02h  A_UINT8 authmode AUTH_MODE
             0x01 NONE_AUTH
             0x02 WPA_AUTH
             0x04 WPA2_AUTH
             0x08 WPA_PSK_AUTH
             0x10 WPA2_PSK_AUTH
             0x20 WPA_AUTH_CCKM
             0x40 WPA2_AUTH_CCKM
      03h  A_UINT8 pairwiseCryptoType CRYPTO_TYPE
             0x01 NONE_CRYPT
             0x02 WEP_CRYPT
             0x04 TKIP_CRYPT
             0x08 AES_CRYPT
      04h  A_UINT8 pairwiseCryptoLen Length in bytes. Valid when the type is
             WEP_CRYPT, otherwise this should be 0
      05h  A_UINT8 groupCryptoType CRYPTO_TYPE
      06h  A_UINT8 groupCryptoLen Length in bytes. Valid when the type is
             WEP_CRYPT, otherwise this should be 0
      07h  A_UINT8 ssidLength SSID length for the AP mode
      08h  A_UCHAR ssid[32] SSID value for the SoftAP mode
      28h  A_UINT16 channel Channel in which the AP mode has to be started
      2Ah  A_UINT8 bssid[6]
      30h  A_UINT8 ctrl_flags WMI_CONNECT_CTRL_FLAGS_BITS
        0x0001 CONNECT_ASSOC_POLICY_USER  Associative frames are sent using
                 the policy specified by the CONNECT_SEND-_REASSOC flag
        0x0004 CONNECT_IGNORE_WPAx-_GROUP_CIPHER  Ignore the WPAx group cipher
                 for WPA/WPA2
        0x0040 CONNECT_DO_WPA_OFFLOAD  Use the authenticator in the QCA4002(=chip)
        0x0100 CONNECT_WPS_FLAG   Set to indicate that the AP will add WPS IE to
                 its beacon
        0xFFFF                    Reset all control flags

Uh, the flags are said to be 8bit... but can be as large as FFFFh?
Also, 3DS seems to use 34h bytes total... so flags would be 32bit maybe?
Whereof, 3DS seems to be simply ignoring param [2Ah..33h].
WMIcmd(F010h or 004Fh) - WMI_AP_SET_MLME_CMD
Parameters:

      00h  A_UINT8  6  mac[ATH_MAC_LEN];
      06h  A_UINT16 2  reason;              /* 802.11 reason code
      08h  A_UINT8  1  cmd;                 /* operation to perform

MLME Commands (aka above "cmd"):

      WMI_AP_MLME_ASSOC       1   /* associate station
      WMI_AP_DISASSOC         2   /* disassociate station
      WMI_AP_DEAUTH           3   /* deauthenticate station
      WMI_AP_MLME_AUTHORIZE   4   /* authorize station
      WMI_AP_MLME_UNAUTHORIZE 5   /* unauthorize station

WMIcmd(F011h or 0050h) - WMI_AP_SET_PVB_CMD
Parameters (06h bytes on 3DS, but other variant exists, too):

      06h 08h  <---- total size (on 3DS it's 06h)
      00h 00h  A_BOOL   4  flag;
      --  04h  A_UINT16 2  rsvd;
      04h 06h  A_UINT16 2  aid;

Note: The 3DS command list does support the 6-byte variant, but it seem to be simply ignoring the command & parameters.
WMIcmd(F012h or 0051h) - WMI_AP_CONN_INACT_CMD
Parameters:

      00h  A_UINT32 4  period;

WMIcmd(F013h or 0052h) - WMI_AP_PROT_SCAN_TIME_CMD
Parameters:

      00h  A_UINT32 4  period_min;
      04h  A_UINT32 4  dwell_ms;

     _____________________ Below doesn't seem to exist on 3DS _____________________

WMIcmd(F014h) - WMI_AP_SET_COUNTRY_CMD ;aka formerly WMI_SET_COUNTRY_CMD
Parameters:

      00h  A_UCHAR  3  countryCode[3]      ;two letter ASCII... plus ending 00h?

WMI_DISABLE_REGULATORY_CODE = "FF" ;uh, are that THREE chars?
WMIcmd(F015h) - WMI_AP_SET_DTIM_CMD
Parameters:

      00h  A_UINT8  1  dtim;   ;wake up each N beacon interval units

DTIM interval used to check for multicast packets.
WMIcmd(F016h or N/A) - WMI_AP_MODE_STAT_CMD
Parameters:

      Unknown (if any)

Reply:

      Unknown (if any)

There is an "WMI_AP_MODE_STAT" structure (said to be an event, although there is no WMIevent(xxxxh) number defined for it anywhere) (and, the "action" entry sounds more like an command/parameter than like an event/response?):
WMI_AP_MODE_STAT structure:

      00h  A_UINT32            action;
      04h  WMI_PER_STA_STAT    sta[AP_MAX_NUM_STA];

Mysterious values (probably for the "action" entry:

      AP_GET_STATS   = 0
      AP_CLEAR_STATS = 1

WMI_PER_STA_STAT structure (for the "sta" entries):

      00h  A_UINT32 tx_bytes;
      04h  A_UINT32 tx_pkts;
      08h  A_UINT32 tx_error;
      0Ch  A_UINT32 tx_discard;
      10h  A_UINT32 rx_bytes;
      14h  A_UINT32 rx_pkts;
      18h  A_UINT32 rx_error;
      1Ch  A_UINT32 rx_discard;
      20h  A_UINT32 aid;

WMIcmd(F027h or N/A) - WMI_AP_SET_11BG_RATESET_CMD
Parameters:

      00h  A_UINT8  1  rateset;
     AP_11BG_RATESET1    = 1
     AP_11BG_RATESET2    = 2
     DEF_AP_11BG_RATESET = AP_11BG_RATESET1

WMIcmd(F05Ah or F059h or N/A) - WMI_AP_SET_APSD_CMD
Parameters:

      00h  A_UINT8  1  enable;

WMI_AP_APSD_DISABLED = 0
WMI_AP_APSD_ENABLED = 1
WMIcmd(F05Bh or F05Ah or N/A) - WMI_AP_APSD_BUFFERED_TRAFFIC_CMD
Parameters:

      00h  A_UINT16 2  aid;
      02h  A_UINT16 2  bitmap;
      04h  A_UINT32 4  flags;

WMI_AP_APSD_BUFFERED_TRAFFIC_FLAGS values (only one defined)

      WMI_AP_APSD_NO_DELIVERY_FRAMES_FOR_THIS_TRIGGER = 01h

WMIcmd(F06Eh or N/A) - WMI_AP_JOIN_BSS_CMD
Unknown/undocumented (some new command, invented in 2012 or so).
WMIevent(?) - WMI_AP_MODE_STAT_EVENT ;reply to WMI_AP_MODE_STAT_CMD ?
Maybe there is an event/reply for the "WMI_AP_MODE_STAT_CMD" command (see above).
WMIevent(101Ch) - WMI_PSPOLL_EVENT ;aka WMI_PS_POLL_EVENT ;AP mode related?
Event Data:

      00h  A_UINT16 2  aid;

Whatever. Said to be an "AP mode event". Maybe WMI_SET_AP_PS_CMD related?
WMIcmd(F0AFh) - WMI_AP_PSBUFF_OFFLOAD ;QCA4002 chipset on GT202 WiFi module

      00h  A_UINT8 Enable
              0 Enable buffering mechanism in firmware to handle power save clients
              1 Disable buffering mechanism
      01h  A_UINT8 psBufCount  Range: 1-3,
              Specifies number of buffers allowed to buffer power save packets.

DSi Atheros Wifi - Unimplemented WMI DFS Functions

WMIcmd(F034h) - WMI_SET_DFS_ENABLE_CMD ;aka WMI_SET_DFS_CMD maybe ?
WMIcmd(F035h) - WMI_SET_DFS_MINRSSITHRESH_CMD ;aka WMI_SET_DFS_CMD too ??
WMIcmd(F036h) - WMI_SET_DFS_MAXPULSEDUR_CMD ;aka WMI_SET_DFS_CMD too ??
Parameters:

      Unknown (maybe WMI_SET_DFS_CMD structure?)

There is a "WMI_SET_DFS_CMD" structure defined:

      00h  A_UINT8  1   enable;

Maybe that structure is meant to be used with one of the WMI_SET_DFS_xxx_CMD commands, or maybe it's even meant to be used with ALL of that THREE commands.

      XXX see file "dfs_common.h"

WMIcmd(F037h) - WMI_DFS_RADAR_DETECTED_CMD ;aka WMI_RADAR_DETECTED_CMD
Parameters:

      00h  A_UINT16 2  chan_index;
      02h  A_INT8   1  bang_radar;

WMIevent(102Bh) - WMI_DFS_HOST_ATTACH_EVENT
Event Data:

      00h  A_UINT64 8  ext_chan_busy_ts;
      08h  A_UINT8  1  enable_ar;
      09h  A_UINT8  1  enable_radar;

WMIevent(102Ch) - WMI_DFS_HOST_INIT_EVENT
Event Data:

      00h  A_UINT32 4  dfs_domain;

WMIevent(102Dh) - WMI_DFS_RESET_DELAYLINES_EVENT
WMIevent(102Eh) - WMI_DFS_RESET_RADARQ_EVENT
WMIevent(102Fh) - WMI_DFS_RESET_AR_EVENT
WMIevent(1030h) - WMI_DFS_RESET_ARQ_EVENT
WMIevent(1031h) - WMI_DFS_SET_DUR_MULTIPLIER_EVENT
WMIevent(1032h) - WMI_DFS_SET_BANGRADAR_EVENT
WMIevent(1033h) - WMI_DFS_SET_DEBUGLEVEL_EVENT
Event Data:

      Unknown (if any) (not defined in file "dfs_common.h")

WMIevent(1034h) - WMI_DFS_PHYERR_EVENT
Event Data:

      00h  A_UINT8         1     num_events;
      01h  dfs_event_info  ..    ev_info[WMI_DFS_EVENT_MAX_BUFFER_SIZE];

WMI_DFS_EVENT_MAX_BUFFER_SIZE = ((255)/sizeof(struct dfs_event_info))
Format of the above "dfs_event_info" structure:

      00h  A_UINT64 8  full_ts;       /* 64-bit full timestamp from interrupt time
      08h  A_UINT32 4  ts;            /* Original 15 bit recv timestamp
      0Ch  A_UINT32 4  ext_chan_busy; /* Ext chan busy %
      10h  A_UINT8  1  rssi;          /* rssi of radar event
      11h  A_UINT8  1  dur;           /* duration of radar pulse
      12h  A_UINT8  1  chanindex;     /* Channel of event
      13h  A_UINT8  1  flags;

Values for "flags":

      PRIMARY_CH = 0  ;\flags.bit0
      EXT_CH     = 1  ;/
      AR_EVENT   = 0  ;\flags.bit1
      DFS_EVENT  = 2  ;/

Some more DFS related constants (unknown purpose):

      DFS_UNINIT_DOMAIN = 0     ;Uninitialized dfs domain
      DFS_FCC_DOMAIN    = 1     ;FCC3 dfs domain
      DFS_ETSI_DOMAIN   = 2     ;ETSI dfs domain
      DFS_MKK4_DOMAIN   = 3     ;Japan dfs domain
      MAX_BIN5_DUR      = 131   ;rounded from 131.25=(105*1.25)   ;DFS related
      TRAFFIC_DETECTED = 1      ;whatever                         ;DFS related
      ATH_DEBUG_DFS  = 00000100h  ;Minimal DFS debug        ;\
      ATH_DEBUG_DFS1 = 00000200h  ;Normal DFS debug         ; should match the
      ATH_DEBUG_DFS2 = 00000400h  ;Maximal DFS debug        ; table from if_ath.c
      ATH_DEBUG_DFS3 = 00000800h  ;matched filterID display ;/

DSi Atheros Wifi - Unimplemented WMI P2P Functions

P2P module definitions
P2P_SSID structure:

      00h  A_UINT8  1    ssidLength;
      01h  A_UINT8  20h  ssid[WMI_MAX_SSID_LEN];

WMIcmd(F038h) - WMI_P2P_SET_CONFIG_CMD
Parameters:

      00h  A_UINT8  1  go_intent;
      01h  A_UINT8  3  country[3];
      04h  A_UINT8  1  reg_class;
      05h  A_UINT8  1  listen_channel;
      06h  A_UINT8  1  op_reg_class;
      07h  A_UINT8  1  op_channel;
      09h  A_UINT16 2  config_methods;

WMIcmd(F039h) - WMI_WPS_SET_CONFIG_CMD ;P2P related
Parameters:

      00h  device_type_tuple 4     pri_dev_type;
      --   outcommented?     0     //A_UINT8 pri_device_type[8];
      04h  device_type_tuple 4*5   sec_dev_type[MAX_P2P_SEC_DEVICE_TYPES];
      18h  A_UINT8           10h   uuid[WPS_UUID_LEN];
      28h  A_UINT8           20h   device_name[WPS_MAX_DEVNAME_LEN];
      48h  A_UINT8           1     dev_name_len;

"device_type_tuple" structure (4 bytes):

      00h  A_UINT16 2  categ;
      02h  A_UINT16 2  sub_categ;

MAX_P2P_SEC_DEVICE_TYPES = 5
WPS_UUID_LEN = 16
WPS_MAX_DEVNAME_LEN = 32
WMIcmd(F03Ah) - WMI_SET_REQ_DEV_ATTR_CMD ;P2P related
Parameters:

      00h  device_type_tuple 4     pri_dev_type;
      04h  device_type_tuple 4*5   sec_dev_type[MAX_P2P_SEC_DEVICE_TYPES];
      18h  A_UINT8           6     device_addr[ATH_MAC_LEN];

WMIcmd(F03Bh) - WMI_P2P_FIND_CMD
Parameters:
typedef PREPACK struct {

      00h  A_UINT32 4     timeout;
      04h  A_ENUM   ..    type;  ;A_UINTx or so?  ;aka WMI_P2P_DISC_TYPE

WMI_P2P_DISC_TYPE values:

      WMI_P2P_FIND_START_WITH_FULL = Unknown (0 or 1 or so)
      WMI_P2P_FIND_ONLY_SOCIAL     = WMI_P2P_FIND_START_WITH_FULL+1
      WMI_P2P_FIND_PROGRESSIVE     = WMI_P2P_FIND_START_WITH_FULL+2

WMIcmd(F03Ch) - WMI_P2P_STOP_FIND_CMD
Parameters:

      Unknown (none?)

WMIcmd(F03Dh) - WMI_P2P_GO_NEG_START_CMD
Parameters:

      00h  A_UINT16 2   listen_freq;
      02h  A_UINT16 2   force_freq;
      04h  A_UINT16 2   go_oper_freq;
      06h  A_UINT8  1   dialog_token;
      07h  A_UINT8  6   peer_addr[ATH_MAC_LEN];
      0Dh  A_UINT8  6   own_interface_addr[ATH_MAC_LEN];
      13h  A_UINT8  6   member_in_go_dev[ATH_MAC_LEN];
      19h  A_UINT8  1   go_dev_dialog_token;
      1Ah  P2P_SSID 21h peer_go_ssid;
      3Bh  A_UINT8  1   wps_method;
      3Ch  A_UINT8  1   dev_capab;
      3Dh  A_INT8   1   go_intent;
      3Eh  A_UINT8  1   persistent_grp;

WMIcmd(F03Eh) - WMI_P2P_LISTEN_CMD
Parameters:

      00h  A_UINT32 4   timeout;

WMIcmd(F050h or F053h) - WMI_P2P_GO_NEG_REQ_RSP_CMD
Parameters:

      000h  A_UINT16 2    listen_freq;
      002h  A_UINT16 2    force_freq;
      004h  A_UINT8  1    status;
      005h  A_INT8   1    go_intent;
      006h  A_UINT8  200h wps_buf[512];
      206h  A_UINT16 2    wps_buflen;
      208h  A_UINT8  200h p2p_buf[512];
      408h  A_UINT16 2    p2p_buflen;
      40Ah  A_UINT8  1    dialog_token;
      40Bh  A_UINT8  1    wps_method;
      40Ch  A_UINT8  1    persistent_grp;
      40Dh  A_UINT8  6    sa[ATH_MAC_LEN];

WMIcmd(F051h or F054h) - WMI_P2P_GRP_INIT_CMD
Parameters:

      00h  A_UINT8  1  persistent_group;
      01h  A_UINT8  1  group_formation;

WMIcmd(F052h or F055h) - WMI_P2P_GRP_FORMATION_DONE_CMD
Parameters:

      00h  A_UINT8  6  peer_addr[ATH_MAC_LEN];
      06h  A_UINT8  1  grp_formation_status;

WMIcmd(F053h or F056h) - WMI_P2P_INVITE_CMD
Parameters:

      00h  A_ENUM   ..   role;   ;A_UINTx or so?  ;WMI_P2P_INVITE_ROLE
      ..   A_UINT16 2    listen_freq;
      ..   A_UINT16 2    force_freq;
      ..   A_UINT8  1    dialog_token;
      ..   A_UINT8  6    peer_addr[ATH_MAC_LEN];
      ..   A_UINT8  6    bssid[ATH_MAC_LEN];
      ..   A_UINT8  6    go_dev_addr[ATH_MAC_LEN];
      ..   P2P_SSID 21h  ssid;
      ..   A_UINT8  1    is_persistent;
      ..   A_UINT8  1    wps_method;

WMI_P2P_INVITE_ROLE values:

      WMI_P2P_INVITE_ROLE_GO        = Unknown (0 or 1 or so)
      WMI_P2P_INVITE_ROLE_ACTIVE_GO = WMI_P2P_INVITE_ROLE_GO+1
      WMI_P2P_INVITE_ROLE_CLIENT    = WMI_P2P_INVITE_ROLE_GO+2

WMIcmd(F054h or F057h) - WMI_P2P_INVITE_REQ_RSP_CMD
Parameters:

      000h  A_UINT16 2    force_freq;
      002h  A_UINT8  1    status;
      003h  A_UINT8  1    dialog_token;
      004h  A_UINT8  200h p2p_buf[512];
      204h  A_UINT16 2    p2p_buflen;
      206h  A_UINT8  1    is_go;
      207h  A_UINT8  6    group_bssid[ATH_MAC_LEN];

WMIcmd(F055h or F058h) - WMI_P2P_PROV_DISC_REQ_CMD
Parameters:

      00h  A_UINT16 2    wps_method;
      02h  A_UINT16 2    listen_freq;
      04h  A_UINT8  1    dialog_token;
      05h  A_UINT8  6    peer[ATH_MAC_LEN];
      0Bh  A_UINT8  6    go_dev_addr[ATH_MAC_LEN];
      11h  P2P_SSID 21h  go_oper_ssid;

WMIcmd(F056h or F059h) - WMI_P2P_SET_CMD
Parameters:

      00h  A_UINT8  1    config_id;           ;set to one of WMI_P2P_CONF_ID
     When config_id=1=WMI_P2P_CONFID_LISTEN_CHANNEL  ;WMI_P2P_LISTEN_CHANNEL
      01h  A_UINT8  1    reg_class;
      02h  A_UINT8  1    listen_channel;
     When config_id=2=WMI_P2P_CONFID_CROSS_CONNECT   ;WMI_P2P_SET_CROSS_CONNECT
      01h  A_UINT8  1    flag;
     When config_id=3=WMI_P2P_CONFID_SSID_POSTFIX    ;WMI_P2P_SET_SSID_POSTFIX
      01h  A_UINT8  17h  ssid_postfix[WMI_MAX_SSID_LEN-9];
      18h  A_UINT8  1    ssid_postfix_len;
     When config_id=4=WMI_P2P_CONFID_INTRA_BSS       ;WMI_P2P_SET_INTRA_BSS
      01h  A_UINT8  1    flag;
     When config_id=5=WMI_P2P_CONFID_CONCURRENT_MODE ;WMI_P2P_SET_CONCURRENT_MODE
      01h  A_UINT8  1    flag;
     When config_id=6=WMI_P2P_CONFID_GO_INTENT       ;WMI_P2P_SET_GO_INTENT
      01h  A_UINT8  1    value;
     When config_id=7=WMI_P2P_CONFID_DEV_NAME        ;WMI_P2P_SET_DEV_NAME
      01h  A_UINT8  20h  dev_name[WPS_MAX_DEVNAME_LEN];
      21h  A_UINT8  1    dev_name_len;

WMIcmd(F05Bh or F05Ch) - WMI_P2P_SDPD_TX_CMD
Parameters:

      000h  A_UINT8  1    type;
      001h  A_UINT8  1    dialog_token;
      002h  A_UINT8  1    frag_id;
      003h  A_UINT8  1    reserved1;          /* alignment
      004h  A_UINT8  6    peer_addr[ATH_MAC_LEN];
      00Ah  A_UINT16 2    freq;
      00Ch  A_UINT16 2    status_code;
      00Eh  A_UINT16 2    comeback_delay;
      010h  A_UINT16 2    tlv_length;
      012h  A_UINT16 2    update_indic;
      014h  A_UINT16 2    total_length;
      016h  A_UINT16 2    reserved2;         /* future
      018h  A_UINT8  400h tlv[WMI_P2P_MAX_TLV_LEN];

WMI_P2P_SDPD_TYPE values:

      WMI_P2P_SD_TYPE_GAS_INITIAL_REQ   = 01h
      WMI_P2P_SD_TYPE_GAS_INITIAL_RESP  = 02h
      WMI_P2P_SD_TYPE_GAS_COMEBACK_REQ  = 03h
      WMI_P2P_SD_TYPE_GAS_COMEBACK_RESP = 04h
      WMI_P2P_PD_TYPE_RESP              = 05h
      WMI_P2P_SD_TYPE_STATUS_IND        = 06h

WMI_P2P_SDPD_TRANSACTION_STATUS values:

      WMI_P2P_SDPD_TRANSACTION_PENDING  = 01h
      WMI_P2P_SDPD_TRANSACTION_COMP     = 02h

WMI_P2P_MAX_TLV_LEN = 1024
WMIcmd(F05Ch or F05Dh) - WMI_P2P_STOP_SDPD_CMD
Parameters:

      Unknown (none?)

WMIcmd(F05Dh or F05Eh) - WMI_P2P_CANCEL_CMD
Parameters:

      Unknown (none?)

WMIcmd(F06Dh or N/A) - WMI_GET_P2P_INFO_CMD
Unknown/undocumented (invented around 2012).
...P2P Events...
WMIevent(1036h) - WMI_P2P_GO_NEG_RESULT_EVENT
Event Data:

      00h  A_UINT16 2   freq;
      02h  A_INT8   1   status;
      03h  A_UINT8  1   role_go;
      04h  A_UINT8  20h ssid[WMI_MAX_SSID_LEN];
      24h  A_UINT8  1   ssid_len;
      25h  A_CHAR   9   pass_phrase[WMI_MAX_PASSPHRASE_LEN];
      2Eh  A_UINT8  6   peer_device_addr[ATH_MAC_LEN];
      34h  A_UINT8  6   peer_interface_addr[ATH_MAC_LEN];
      3Ah  A_UINT8  1   wps_method;
      3Bh  A_UINT8  1   persistent_grp;

WMI_MAX_PASSPHRASE_LEN = 9
WMIevent(103Dh) - WMI_P2P_GO_NEG_REQ_EVENT
Event Data:

      000h  A_UINT8  6    sa[ATH_MAC_LEN];
      006h  A_UINT8  200h wps_buf[512];
      206h  A_UINT16 2    wps_buflen;
      208h  A_UINT8  200h p2p_buf[512];
      408h  A_UINT16 2    p2p_buflen;
      40Ah  A_UINT8  1    dialog_token;

WMIevent(103Eh) - WMI_P2P_INVITE_REQ_EVENT
Event Data:

      000h  A_UINT8  200h p2p_buf[512];
      200h  A_UINT16 2    p2p_buflen;
      202h  A_UINT8  6    sa[ATH_MAC_LEN];
      208h  A_UINT8  6    bssid[ATH_MAC_LEN];
      20Eh  A_UINT8  6    go_dev_addr[ATH_MAC_LEN];
      214h  P2P_SSID 21h  ssid;
      235h  A_UINT8  1    is_persistent;
      236h  A_UINT8  1    dialog_token;

WMIevent(103Fh) - WMI_P2P_INVITE_RCVD_RESULT_EVENT
Event Data:

      00h  A_UINT16 2   oper_freq;
      02h  A_UINT8  6   sa[ATH_MAC_LEN];
      08h  A_UINT8  6   bssid[ATH_MAC_LEN];
      0Eh  A_UINT8  1   is_bssid_valid;
      0Fh  A_UINT8  6   go_dev_addr[ATH_MAC_LEN];
      15h  P2P_SSID 21h ssid;
      36h  A_UINT8  1   status;

WMIevent(1040h) - WMI_P2P_INVITE_SENT_RESULT_EVENT
Event Data:

      00h  A_UINT8  1   status;
      01h  A_UINT8  6   bssid[ATH_MAC_LEN];
      07h  A_UINT8  1   is_bssid_valid;

WMIevent(1041h) - WMI_P2P_PROV_DISC_RESP_EVENT
Event Data:

      00h  A_UINT8  6   peer[ATH_MAC_LEN];
      06h  A_UINT16 2   config_methods;

WMIevent(1042h) - WMI_P2P_PROV_DISC_REQ_EVENT
Event Data:

      00h  A_UINT8  6   sa[ATH_MAC_LEN];
      06h  A_UINT16 2   wps_config_method;
      08h  A_UINT8  6   dev_addr[ATH_MAC_LEN];
      0Eh  A_UINT8  8   pri_dev_type[WPS_DEV_TYPE_LEN];
      16h  A_UINT8  20h device_name[WPS_MAX_DEVNAME_LEN];
      36h  A_UINT8  1   dev_name_len;
      37h  A_UINT16 2   dev_config_methods;
      39h  A_UINT8  1   device_capab;
      3Ah  A_UINT8  1   group_capab;

WPS_DEV_TYPE_LEN = 8
WMIevent(1043h) - WMI_P2P_START_SDPD_EVENT
Event Data:

      Unknown (none?)

WMIevent(1044h) - WMI_P2P_SDPD_RX_EVENT
Event Data:

      00h  A_UINT8  1   type;
      01h  A_UINT8  1   transaction_status;
      02h  A_UINT8  1   dialog_token;
      03h  A_UINT8  1   frag_id;
      04h  A_UINT8  6   peer_addr[ATH_MAC_LEN];
      0Ah  A_UINT16 2   freq;
      0Ch  A_UINT16 2   status_code;
      0Eh  A_UINT16 2   comeback_delay;
      10h  A_UINT16 2   tlv_length;
      12h  A_UINT16 2   update_indic;
      14h  VAR      ..  Variable length TLV will be placed after the event

DSi Atheros Wifi - Unimplemented WMI WAC Functions

WMIcmd(F043h) - WMI_WAC_ENABLE_CMD aka WMI_ENABLE_WAC_CMD
Parameters:

      00h  A_UINT32 4   period;
      04h  A_UINT32 4   threshold;
      08h  A_INT32  4   rssi;
      0Ch  A_BOOL   4   enable;
      10h  A_CHAR   8   wps_pin[8];     ;WPS related?

WMIcmd(F044h) - WMI_WAC_SCAN_REPLY_CMD
Parameters:

      00h  A_ENUM   ..  cmdid ;A_UINTx or so?  (WAC_SUBCMD)

WAC_SUBCMD values:

      WAC_MORE_SCAN      = -1
      WAC_SEND_PROBE_IDX = 0

WMIcmd(F045h) - WMI_WAC_CTRL_REQ_CMD
Parameters:

      00h  A_UINT8  1   req;     ;aka WAC_REQUEST_TYPE
      01h  A_UINT8  1   cmd;     ;aka WAC_COMMAND
      02h  A_UINT8  1   frame;   ;aka WAC_FRAME_TYPE
      03h  A_UINT8  11h ie[17];
      14h  A_INT32  4   status;  ;aka WAC_STATUS

WAC related constants (from wac_defs.h):
WAC_REQUEST_TYPE values:

      WAC_SET        = Unknown (0 or 1 or so)
      WAC_GET        = WAC_SET+1

WAC_COMMAND values:

      WAC_ADD        = Unknown (0 or 1 or so)
      WAC_DEL        = WAC_ADD+1
      WAC_GET_STATUS = WAC_ADD+2
      WAC_GET_IE     = WAC_ADD+3

WAC_FRAME_TYPE values:

      PRBREQ         = Unknown (0 or 1 or so)
      PRBRSP         = PRBREQ+1
      BEACON         = PRBREQ+2

WAC_STATUS values:

      WAC_FAILED_NO_WAC_AP      = -4
      WAC_FAILED_LOW_RSSI       = -3
      WAC_FAILED_INVALID_PARAM  = -2
      WAC_FAILED_REJECTED       = -1
      WAC_SUCCESS               = 0
      WAC_DISABLED              = 1
      WAC_PROCEED_FIRST_PHASE   = 2
      WAC_PROCEED_SECOND_PHASE  = 3

WMIevent(1037h) - WMI_WAC_SCAN_DONE_EVENT
WMIevent(1038h) - WMI_WAC_REPORT_BSS_EVENT
WMIevent(1039h) - WMI_WAC_START_WPS_EVENT
WMIevent(103Ah) - WMI_WAC_CTRL_REQ_REPLY_EVENT
Event Data:

      Unknown (if any?)

WAC Events. Event data format is unknown, maybe related to below two structs:
WMI_GET_WAC_INFO structure (UNION):

     When some case:
      00h  A_UINT8  11h  ie[17];
     When some other case:
      00h  A_INT32  4    wac_status;

WMI_WPS_PIN_INFO structure: ;"WPS" might be WAC_START_WPS related?

      00h  A_UINT8  6  bssid[ATH_MAC_LEN];
      06h  A_UINT8  8  pin[8];        ;aka "wps_pin[8]" presumably?

DSi Atheros Wifi - Unimplemented WMI RF Kill and Store/Recall Functions

WMIcmd(F057h or F04Bh) - WMI_GET_RFKILL_MODE_CMD
Parameters:

      Unknown (none?)

Reply: See WMI_RFKILL_GET_MODE_CMD_EVENT
WMIcmd(F058h or F04Ch) - WMI_SET_RFKILL_MODE_CMD ;aka WMI_RFKILL_MODE_CMD
Parameters:

      00h  A_UINT8  1  GPIOPinNumber  ;GPIO related
      01h  A_UINT8  1  IntrType       ;?
      02h  A_UINT8  1  RadioState     ;RFKILL_RADIO_STATE

RFKILL_RADIO_STATE values:

      RADIO_STATE_OFF     = 01h
      RADIO_STATE_ON      = 02h
      RADIO_STATE_INVALID = FFh

WMIevent(103Bh) - WMI_RFKILL_STATE_CHANGE_EVENT
Event Data:

      Unknown (if any?)

WMIevent(103Ch) - WMI_RFKILL_GET_MODE_CMD_EVENT
Event Data:

      Unknown (maybe some format as in "SET_RFKILL" command parameters?)

WMIcmd(F05Eh or F04Eh) - WMI_STORERECALL_CONFIGURE_CMD
Parameters:

      00h  A_UINT8 1  enable (probably some flag)
      01h  A_UINT8 1  recipient (only one value defined: STRRCL_RECIPIENT_HOST = 1)

Ultra low power store/recall feature. Seems to be intended to memorize data in HOST memory... allowing the AR600x chip to power-down its on memory, or so?
WMIcmd(F05Fh or F04Fh) - WMI_STORERECALL_RECALL_CMD
Parameters:

      00h  A_UINT32 4  length;      ;number of bytes of data to follow
      04h  A_UINT8  .. data[1];     ;start of "RECALL" data

Ultra low power store/recall feature. Maybe RECALL is meant to restore data that was formerly memorized from a WMI_STORERECALL_STORE_EVENT.
WMIcmd(F060h or F050h) - WMI_STORERECALL_HOST_READY_CMD
Parameters:

      00h  A_UINT32 4  sleep_msec;
      04h  A_UINT8  1  store_after_tx_empty;
      05h  A_UINT8  1  store_after_fresh_beacon_rx;

Ultra low power store/recall feature. Whatever parameters.
WMIevent(9004h) - WMI_STORERECALL_STORE_EVENT
Event Data:

      00h  A_UINT32 4  msec_sleep;   ;time between power off/on
      04h  A_UINT32 4  length;       ;length of following data
      08h  A_UINT8  .. data[1];      ;start of "STORE" data

Ultra low power store/recall feature. Maybe this requests to memorize the "STORE" data in host memory?

DSi Atheros Wifi - Unimplemented WMI THIN Functions

WMIcmd(8000h) - WMI_THIN_RESERVED_START
WMIcmd(8FFFh) - WMI_THIN_RESERVED_END
Area for Thin commands. These command IDs can be found in "wmi_thin.h".
WMIcmd(8000h) - WMI_THIN_CONFIG_CMD
Parameters:

      00h  A_UINT32 4   cfgField      ;combination of WMI_THIN_CFG_...
      04h  A_UINT16 2   length        ;length in bytes of appended sub-command(s)
      06h  A_UINT8  2   reserved[2]   ;align padding
      08h  ...      ..  structure(s) selected in "cfgField"...

When cfgField.Bit0 set: append WMI_THIN_CONFIG_TXCOMPLETE struct:
Used to configure the params and content for TX Complete messages the will come from the Target. these messages are disabled by default but can be enabled using this structure and the WMI_THIN_CONFIG_CMDID.

      +00h  A_UINT8  1  version (the versioned type of messages to use, 0=disable)
      +01h  A_UINT8  1  countThreshold (msg count threshold triggering a tx
                         complete message)
      +02h  A_UINT16 2  timeThreshold (timeout interval in MSEC triggering a
                         tx complete message)

When cfgField.Bit1 set: append WMI_THIN_CONFIG_DECRYPT_ERR struct:
Used to configure behavior for received frames that have decryption errors. The default behavior is to discard the frame without notification. Alternately, the MAC Header is forwarded to the host with the failed status.

      +00h  A_UINT8  1  enable (1=send decrypt errors to the host, 0=don't)
      +01h  A_UINT8  3  reserved[3] (align padding)

When cfgField.Bit2 set: Unused --- NEW VERSION

      Unused.

When cfgField.Bit2 set: append WMI_THIN_CONFIG_TX_MAC_RULES --- OLD VERSION
Used to configure behavior for transmitted frames that require partial MAC header construction. These rules are used by the target to indicate which fields need to be written.

      +00h  A_UINT32 4  rules (combination of WMI_WRT_... values)

When cfgField.Bit3 set: append WMI_THIN_CONFIG_RX_FILTER_RULES struct:
Used to configure behavior for received frames as to which frames should get forwarded to the host and which should get processed internally.

      +00h  A_UINT32 4  rules (combination of WMI_FILT_... values)

When cfgField.Bit4 set: append WMI_THIN_CONFIG_CIPHER_ENCAP struct:
Used to configure behavior for both TX and RX frames regarding security cipher encapsulation. The host may specify whether or not the firmware is responsible for cipher encapsulation. If the firmware is responsible it will add the security header and trailer for TX frames and remove the header and trailer for Rx frames. Also, the firmware will examine the resource counter if any and behave appropriately when a bad value is detected. If the host indicates responsibility for encapsulation then it is responsible for all aspects of encapsulation, however the device will still perform the encryption and decryption of the frame payload if a key has been provided.

      +00h  A_UINT8  1  enable (enables/disables firmware cipher encapsulation)
      +01h  A_UINT8  3  reserved[3] (align padding)

Summary of values for "cfgField":

      WMI_THIN_CFG_TXCOMP       = 00000001h
      WMI_THIN_CFG_DECRYPT      = 00000002h
      WMI_THIN_CFG_MAC_RULES    = 00000004h ;old version (or planned for future?)
      WMI_THIN_UNUSED1          = 00000004h ;current version
      WMI_THIN_CFG_FILTER_RULES = 00000008h
      WMI_THIN_CFG_CIPHER_ENCAP = 00000010h

WMIcmd(8001h) - WMI_THIN_SET_MIB_CMD
Parameters:

      00h  A_UINT16 2  length;     /* the length in bytes of the appended MIB data
      02h  A_UINT8  1  mibID;      /* the ID of the MIB element being set
      03h  A_UINT8  1  reserved;   /* align padding

WMIcmd(8002h) - WMI_THIN_GET_MIB_CMD ;reply?
Parameters:

      00h  A_UINT8  1   mibID;        /* the ID of the MIB element being set
      01h  A_UINT8  3   reserved[3];  /* align padding

Reply: See WMI_THIN_GET_MIB_EVENT
WMIcmd(8003h) - WMI_THIN_JOIN_CMD ;newer ver only
Parameters:

      00h  A_UINT32 4   basicRateMask;    /* bit mask of basic rates
      04h  A_UINT32 4   beaconIntval;     /* TUs
      08h  A_UINT16 2   atimWindow;       /* TUs
      0Ah  A_UINT16 2   channel;          /* frequency in MHz
      0Ch  A_UINT8  1   networkType;      /* INFRA_NETWORK | ADHOC_NETWORK
      0Dh  A_UINT8  1   ssidLength;       /* 0 - 32
      0Eh  A_UINT8  1   probe;            /* != 0 : issue probe req at start
      0Fh  A_UINT8  1   reserved;         /* alignment
      10h  A_UCHAR  20h ssid[WMI_MAX_SSID_LEN];
      30h  A_UINT8  6   bssid[ATH_MAC_LEN];

Reply: See WMI_THIN_JOIN_EVENT
WMIcmd(8004h) - WMI_THIN_CONNECT_CMD ;newer ver only
Parameters:

      00h  A_UINT16 2  dtim;   /* dtim interval in num beacons
      02h  A_UINT16 2  aid;    /* 80211 association ID from Assoc resp

WMIcmd(8005h) - WMI_THIN_RESET_CMD ;newer ver only
Parameters:

      00h  A_UINT8  4  reserved[4];

WMIevent(8000h) - WMI_THIN_EVENTID_RESERVED_START
WMIevent(8FFFh) - WMI_THIN_EVENTID_RESERVED_END
Events/Responses with special IDs for THIN stuff (wmi_thin.h)
WMIevent(8001h) - WMI_THIN_GET_MIB_EVENT
Event Data:

      Unknown (maybe same/similar format as for "SET_MIB" command parameters?)

WMIevent(8002h) - WMI_THIN_JOIN_EVENT
Event Data:

      00h  A_UINT8 1  result (the result of the join command)
      01h  A_UINT8 3  reserved[3]; /* alignment

WMI_THIN_JOIN_RESULT values (aka above "result" value):

      WMI_THIN_JOIN_RES_SUCCESS    = 0  ;device has joined the network
      WMI_THIN_JOIN_RES_FAIL       = 1  ;failed for unspecified reason
      WMI_THIN_JOIN_RES_TIMEOUT    = 2  ;failed due to no beacon rx in time limit
      WMI_THIN_JOIN_RES_BAD_PARAM  = 3  ;failed due to bad cmd param
      WMI_THIN_JOIN_RES_IBSS_START = 4  ;device started new IBSS network

MIB Access Identifiers tailored for Symbian - mibID
Below are "mibID" values for SET_MIB and GET_MIB commands, with corresponding data structures. GET/SET works only if the corresponding structure is read/write-able, as indicated by (R), (W), and (R/W). Some structures aren't actually implemented (-), ie. not read/write-able.

     When mibID=01h=MIB_ID_STA_MAC; WMI_THIN_MIB_STA_MAC struct:                (R)
      00h  A_UINT8  6  addr[ATH_MAC_LEN];
     When mibID=02h=MIB_ID_RX_LIFE_TIME; WMI_THIN_MIB_RX_LIFE_TIME struct:      (-)
      00h  A_UINT32 4  time (units = msec)
     When mibID=03h=MIB_ID_SLOT_TIME; WMI_THIN_MIB_SLOT_TIME struct:          (R/W)
      00h  A_UINT32 4  time (units = usec)
     When mibID=04h=MIB_ID_RTS_THRESHOLD; WMI_THIN_MIB_RTS_THRESHOLD struct:  (R/W)
      00h  A_UINT16 2  length (units = bytes)
     When mibID=05h=MIB_ID_CTS_TO_SELF; WMI_THIN_MIB_CTS_TO_SELF struct:      (R/W)
      00h  A_UINT8  1  enable (1=on, 0=off)
     When mibID=06h=MIB_ID_TEMPLATE_FRAME; WMI_THIN_MIB_TEMPLATE_FRAME struct:  (W)
      00h  A_UINT8  1  type (type of frame, 0..5, see below "FRM" values)
      01h  A_UINT8  1  rate (tx rate to be used, one of WMI_BIT_RATE)
      02h  A_UINT16 2  length (num bytes following this structure as template data)
      04h  ..       .. template data
      Frame "type" values:          frame max length:
      TEMPLATE_FRM_PROBE_REQ = 0    FRM_LEN_PROBE_REQ  = 256  ;\Symbian dictates a
      TEMPLATE_FRM_BEACON    = 1    FRM_LEN_BEACON     = 256  ; minimum of 256 for
      TEMPLATE_FRM_PROBE_RESP= 2    FRM_LEN_PROBE_RESP = 256  ;/these 3 frame types
      TEMPLATE_FRM_NULL      = 3    FRM_LEN_NULL       = 32
      TEMPLATE_FRM_QOS_NULL  = 4    FRM_LEN_QOS_NULL   = 32
      TEMPLATE_FRM_PSPOLL    = 5    FRM_LEN_PSPOLL     = 32
      Total sum of above lengths: TEMPLATE_FRM_LEN_SUM = 256+256+256+32+32+32
     When mibID=07h=MIB_ID_RXFRAME_FILTER; WMI_THIN_MIB_RXFRAME_FILTER struct:(R/W)
      00h  A_UINT32 4  filterMask;
      FRAME_FILTER_PROMISCUOUS = 00000001h
      FRAME_FILTER_BSSID       = 00000002h
     When mibID=08h=MIB_ID_BEACON_FILTER_TABLE; Several structure(s)...?        (W)
      There are three related sturctures; the actual "TABLE", and additional
      "TABLE_OUI" and "TABLE_HEADER"; unknown which of those structure(s) are
      meant to be used here...
      WMI_THIN_MIB_BEACON_FILTER_TABLE structure:
      00h  A_UINT8  1  ie;
      01h  A_UINT8  1  treatment;
      IE_FILTER_TREATMENT_CHANGE = 1
      IE_FILTER_TREATMENT_APPEAR = 2
      WMI_THIN_MIB_BEACON_FILTER_TABLE_OUI structure:
      00h  A_UINT8  1  ie;
      01h  A_UINT8  1  treatment;
      02h  A_UINT8  3  oui[3];
      05h  A_UINT8  1  type;
      06h  A_UINT16 2  version;
      WMI_THIN_MIB_BEACON_FILTER_TABLE_HEADER structure:
      00h  A_UINT16 2  numElements
      02h  A_UINT8  1  entrySize (sizeof(WMI_THIN_MIB_BEACON_FILTER_TABLE) on
      03h  A_UINT8  1  reserved                    host cpu may be 2 may be 4)
     When mibID=09h=MIB_ID_BEACON_FILTER; WMI_THIN_MIB_BEACON_FILTER struct:  (R/W)
      00h  A_UINT32 4  count (num beacons between deliveries)
      04h  A_UINT8  1  enable;
      05h  A_UINT8  3  reserved[3];
     When mibID=0Ah=MIB_ID_BEACON_LOST_COUNT; WMI_THIN_MIB_BEACON_LOST_COUNT:   (W)
      00h  A_UINT32 4  count (num consec lost beacons after which send event)
     When mibID=0Bh=MIB_ID_RSSI_THRESHOLD; WMI_THIN_MIB_RSSI_THRESHOLD struct:  (W)
      00h  A_UINT8 1   rssi (the low threshold which can trigger an event warning)
      01h  A_UINT8 1   tolerance (the range above and below the threshold to
                        prevent event flooding to the host)
      02h  A_UINT8 1   count (the sample count of consecutive frames necessary to
                        trigger an event)
      03h  A_UINT8 1   reserved[1] (padding)
     When mibID=0Ch=MIB_ID_HT_CAP; WMI_THIN_MIB_HT_CAP struct:                  (-)
      00h  A_UINT32 4  cap;
      04h  A_UINT32 4  rxRateField;
      08h  A_UINT32 4  beamForming;
      0Ch  A_UINT8  6  addr[ATH_MAC_LEN];
      12h  A_UINT8  1  enable;
      13h  A_UINT8  1  stbc;
      14h  A_UINT8  1  maxAMPDU;
      15h  A_UINT8  1  msduSpacing;
      16h  A_UINT8  1  mcsFeedback;
      17h  A_UINT8  1  antennaSelCap;
     When mibID=0Dh=MIB_ID_HT_OP; WMI_THIN_MIB_HT_OP struct:                    (-)
      00h  A_UINT32 4  infoField;
      04h  A_UINT32 4  basicRateField;
      08h  A_UINT8  1  protection;
      09h  A_UINT8  1  secondChanneloffset;
      0Ah  A_UINT8  1  channelWidth;
      0Bh  A_UINT8  1  reserved;
     When mibID=0Eh=MIB_ID_HT_2ND_BEACON; WMI_THIN_MIB_HT_2ND_BEACON struct:    (-)
      00h  A_UINT8  1  cfg (see below SECOND_BEACON_xxx values)
      01h  A_UINT8  3  reserved[3] (padding)
      SECOND_BEACON_PRIMARY   = 1
      SECOND_BEACON_EITHER    = 2
      SECOND_BEACON_SECONDARY = 3
     When mibID=0Fh=MIB_ID_HT_BLOCK_ACK; WMI_THIN_MIB_HT_BLOCK_ACK struct:      (-)
      00h  A_UINT8  1  txTIDField
      01h  A_UINT8  1  rxTIDField
      02h  A_UINT8  2  reserved[2] (padding)
     When mibID=10h=MIB_ID_PREAMBLE; WMI_THIN_MIB_PREAMBLE struct:            (R/W)
      00h  A_UINT8  1  enableLong (1=long preamble, 0=short preamble)
      01h  A_UINT8  3  reserved[3]
     When mibID=N/A=MIB_ID_GROUP_ADDR_TABLE    ;[NOT IMPLEMENTED]               (-)
     When mibID=N/A=MIB_ID_WEP_DEFAULT_KEY_ID  ;satisfied by wmi_addKey_cmd()   (-)
     When mibID=N/A=MIB_ID_TX_POWER            ;[NOT IMPLEMENTED]               (-)
     When mibID=N/A=MIB_ID_ARP_IP_TABLE        ;[NOT IMPLEMENTED]               (-)
     When mibID=N/A=MIB_ID_SLEEP_MODE          ;[NOT IMPLEMENTED]               (-)
     When mibID=N/A=MIB_ID_WAKE_INTERVAL       ;[NOT IMPLEMENTED]               (-)
     When mibID=N/A=MIB_ID_STAT_TABLE          ;[NOT IMPLEMENTED]               (-)
     When mibID=N/A=MIB_ID_IBSS_PWR_SAVE       ;[NOT IMPLEMENTED]               (-)
     When mibID=N/A=MIB_ID_COUNTERS_TABLE      ;[NOT IMPLEMENTED]               (-)
     When mibID=N/A=MIB_ID_ETHERTYPE_FILTER    ;[NOT IMPLEMENTED]               (-)
     When mibID=N/A=MIB_ID_BC_UDP_FILTER       ;[NOT IMPLEMENTED]               (-)
      N/A

THIN related constants...
MAC Header Build Rules
These values allow the host to configure the target code that is responsible for constructing the MAC header. In cases where the MAC header is provided by the host framework, the target has a diminished responsibility over what fields it must write. This will vary from framework to framework.
Symbian requires different behavior from MAC80211 which requires different behavior from MS Native Wifi.

      WMI_WRT_VER_TYPE  = 00000001h
      WMI_WRT_DURATION  = 00000002h
      WMI_WRT_DIRECTION = 00000004h
      WMI_WRT_POWER     = 00000008h
      WMI_WRT_WEP       = 00000010h
      WMI_WRT_MORE      = 00000020h
      WMI_WRT_BSSID     = 00000040h
      WMI_WRT_QOS       = 00000080h
      WMI_WRT_SEQNO     = 00000100h
      WMI_GUARD_TX      = 00000200h ;prevent TX ops that are not allowed for a
                                    ; current state
      WMI_WRT_DEFAULT_CONFIG = 3FFh             ;<-- default all bits set

See also: WMI_SET_THIN_MODE_CMD

DSi Atheros Wifi - Unimplemented WMI Pyxis Functions

WMIcmd(F009h) - WMI_UNUSED1 or WMI_PYXIS_CONFIG_CMD
Parameters:

     Config Header:
      00h  A_UINT16 2  pyxisConfigType ;One of WMI_PYXIS_CONFIG_TYPE
      02h  A_UINT16 2  pyxisConfigLen  ;Length in Bytes of Information that follows
     When pyxisConfigType=0=WMI_PYXIS_GEN_PARAMS
      04h  A_UINT32 2  dataWindowSizeMin
      08h  A_UINT32 2  dataWindowSizeMax
      0Ch  A_UINT8  1  maxJoiners
     When pyxisConfigType=1=WMI_PYXIS_DSCVR_PARAMS
      04h  A_UINT32 4  dscvrWindow
      08h  A_UINT32 4  dscvrInterval
      0Ch  A_UINT32 4  dscvrLife
      10h  A_UINT32 4  probeInterval
      14h  A_UINT32 4  probePeriod
      18h  A_UINT16 2  dscvrChannel
     When pyxisConfigType=2=WMI_PYXIS_SET_TX_MODE
      04h  A_BOOL   4  mode

Whatever "Pyxis specific".
WMIcmd(F00Ah) - WMI_UNUSED2 or WMI_PYXIS_OPERATION_CMD
Parameters:

     Command Header:
      00h  A_UINT16 2  pyxisCmd
      02h  A_UINT16 2  pyxisCmdLen   ;Length following this header
     When pyxisCmd=0=WMI_PYXIS_DISC_PEER
      04h  A_UINT8  6  peerMacAddr[ATH_MAC_LEN]
     When pyxisCmd=1=WMI_PYXIS_JOIN_PEER
      04h  A_UINT32 4  ctrl_flags (One of the Bits determines if it
                        is Virt Adhoc/the device is to join a BSS)
      08h  A_UINT16 2  channel                  ;Data Channel
      0Ah  A_UINT8  1  networkType              ;network type
      0Bh  A_UINT8  1  dot11AuthMode            ;OPEN_AUTH
      0Ch  A_UINT8  1  authMode                 ;NONE_AUTH
      0Dh  A_UINT8  1  pairwiseCryptoType       ;One of NONE_CRYPT, AES_CRYPT
      0Eh  A_UINT8  1  pairwiseCryptoLen        ;0 since ADD_KEY passes the length
      0Fh  A_UINT8  1  groupCryptoType          ;One of NONE_CRYPT, AES_CRYPT
      10h  A_UINT8  1  groupCryptoLen           ;0 since ADD_KEY passes the length
      11h  A_UINT8  6  peerMacAddr[ATH_MAC_LEN] ;BSSID of peer network
      17h  A_UINT8  6  nwBSSID[ATH_MAC_LEN]     ;BSSID of the Pyxis Adhoc Network
     When pyxisCmd=?=WHAT? below is also "incompletely-defined" as pyxisCmd:
      04h  A_BOOL   4  mode (what is this here? dupe of WMI_PYXIS_CONFIG_CMD?)

Whatever "Pyxis specific".

DSi Atheros Wifi I2C EEPROM

The I2C EEPROM is read via the wifi firmware's bootstub (prior to executing the main firmware) via the SI_xxx registers. The DSi wifi boards are usually containing a HN58X2408F chip (1Kx8, with 8bit index). However, the bootstub contains code for also supporting HN58X24xx chips with bigger capacity (including such with 16bit index) (although actually using only 300h bytes regardless of the capacity). The I2C device number is A0h, or, in case of EEPROMs with 8bit index, the device number is misused to contain the upper address bits as so:

      device = A0h + direction_flag + (addr/100h)*2  ;for devices with 8bit index
      device = A0h + direction_flag                  ;for devices with 16bit index

I2C EEPROM Content for AR6002G

      000h 4     Maybe Size, ID, or Version? (00000300h)
      004h 2     Checksum (all halfwords at [0..2FFh] XORed shall give FFFFh)
      006h 2     Unknown
      008h 2     Country+8000h  ;eg. 8000h+188h=JP, 8000h+348h=US (REG_DOMAIN)
      00Ah 6     MAC Address (must be same as in SPI FLASH)
      010h 4     Type/version? (MSB must be 60h, verified by ARM7)
      014h 4     Zerofilled
      018h 5     Unknown
      01Dh 1Fh   Zerofilled
      03Ch 70h   FFh-filled
      0ACh 8     Zerofilled
      0B4h 12    Unknown
      0C0h 20    Unknown
      0D4h 18h   Zerofilled
      0ECh 4     Unknown
      0F0h 4     Unknown, overwritten by [0ECh] after loading
      0F4h 12    Unknown, similar to data at 0B4h ?
      100h 20    Unknown, similar to data at 0C0h ?
      114h 2Ch   Zerofilled
      140h 8     FFh-filled
      148h 4     Unknown
      14Ch 88h   Zerofilled
      1D4h 3x18  Unknown
      212h 18    Zerofilled
      224h 4x4   Unknown       ;\
      234h 2x4   Unknown       ;
      23Ch 3x4   Unknown       ; together 15x4 maybe ?
      248h 12    Unknown       ;
      254h 3x4   Unknown       ;/
      260h 60h   Unknown
      2C0h 40h   Zerofilled
      300h 100h  Not used (not loaded to RAM)

The presence of the I2C EEPROM appears to be some mis-conception. It might make sense to store the wifi calibration data on the daughterboard (rather than in eMMC storage on mainboard), however, it could be as well stored in the SPI FLASH chip, but Nintendo apparently didn't knew how to do that.

DSi Atheros Wifi Internal Hardware

Below describes the internal Atheros hardware. The hardware registers can be accessed via WINDOW_DATA, or by uploading custom code to the Xtensa CPU via BMI Bootloader commands.
Anyways, normally, the Wifi unit should be accessed via WMI commands, so one won't need to deal with internal hardware (except cases like reading the CHIP_ID, or for better understanding of the inner workings of the hardware).
Internal Xtensa CPU
DSi Atheros Wifi - Xtensa CPU Registers
DSi Atheros Wifi - Xtensa CPU Core Opcodes
DSi Atheros Wifi - Xtensa CPU Optional General Opcodes
DSi Atheros Wifi - Xtensa CPU Optional Exception/Cache/MMU Opcodes
DSi Atheros Wifi - Xtensa CPU Optional Floating-Point Opcodes
DSi Atheros Wifi - Xtensa CPU Optional MAC16 Opcodes
DSi Atheros Wifi - Xtensa CPU Opcode Encoding Tables
Internal Memory and I/O Maps
DSi Atheros Wifi - Internal Memory Map
DSi Atheros Wifi - Internal I/O Map Summary (hw2)
DSi Atheros Wifi - Internal I/O Map Summary (hw4)
DSi Atheros Wifi - Internal I/O Map Summary (hw6)
Note: All DSi/3DS boards are using hw2 (though with minor changes between AR6002 and AR6013/AR6014 on the GPIO I2C pin wiring, and external oscillator). The hw4/hw6 variants are shown here only for curiosity, they aren't used anywhere in DSi/3DS).
AR60XX Internal Registers
DSi Atheros Wifi - Internal I/O - Unknown and Unused Registers (hw2)
DSi Atheros Wifi - Internal I/O - 004000h - RTC/Clock SOC (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 00x000h - RTC/Clock WLAN (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 0xx240h - RTC/Clock SYNC (hw6)
DSi Atheros Wifi - Internal I/O - 006000h - WLAN Coex (MCI) (hw6)
DSi Atheros Wifi - Internal I/O - 00x000h - Bluetooth Coex (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 00x000h - Memory Control (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 00C000h - Serial UART (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 00E000h - UMBOX Registers (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 010000h - Serial I2C/SPI (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 014000h - GPIO 18/26/57 pin (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 018000h - MBOX Registers (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 01C000h - Analog Intf (hw2)
DSi Atheros Wifi - Internal I/O - 01C000h - Analog Intf (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 020000h - WMAC DMA (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 020080h - WMAC IRQ Interrupt (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 020800h - WMAC QCU Queue (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 021000h - WMAC DCU (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 028000h - WMAC PCU (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 029800h - BB Baseband (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 0xxx00h - RDMA Registers (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 03x000h - EFUSE Registers (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 034000h - More Stuff (hw6)

DSi Atheros Wifi - Xtensa CPU Registers

Xtensa Core Registers

      -              AR      Address registers A0..A15 (general purpose registers)
      -              PC      Program Counter

The AR registers are used as so:

      A0       general purpose (and return address for CALL/RET opcodes)
      A1       general purpose (commonly used as stack pointer)
      A2..A15  general purpose

Chips with Windowed Code option are actually having more than sixteen AR registers, and the register window is rotated by CALL4/CALL8/CALL12/RETW opcodes (allowing to save/restore registers without needing to push/pop them in memory):

      CALL4   saves A0..A3 and moves A4..A15 to A0..A11  ;\and, probably copies
      CALL8   saves A0..A7 and moves A8..A15 to A0..A7   ; old A1 to new A1 (?),
      CALL12  saves A0..A11 and moves A12..A15 to A0..A3 ;/and new A0=ret_addr
      ENTRY   used at begin of sub-functions (allocate local variables on stack)
      RETW    windowed return (deallocate locals, and undo the CALL4/8/12 rotation)

The sub-functions will have retaddr/stack in A0/A1, and incoming parameters in A2 and up, and return value in A2. However, due to the rotation, the caller will see parameters/return value elsewhere (eg. for CALL8, parameters in A10 and up, and return value in A10).
The ENTRY opcode is used to allocate local variables on stack. For some weird reason ENTRY is usually also allocating "N*4 bytes" dummy space for the "N" saved words (as if they were intended to be pushed on stack, rather than being saved via rotation, maybe some exception handler is actually USING that dummy space when the register window gets full(?), the AR6002 BIOS contains a few functions that aren't allocating enough dummy words though, eg. 8EDE44h uses "entry a1,10h" although being called via CALL8).
Xtensa Special Registers

      0        00h   LBEG    Loop Begin                  ;\
      1        01h   LEND    Loop End                    ; Loop option
      2        02h   LCOUNT  Loop Count                  ;/
      3        03h   SAR     Shift-Amount Register       ;-Core
      4        04h   BR      Boolean Registers (16x1bit) ;-Boolean option
      5        05h   LITBASE Literal Base                ;-Literal base option
      12       0Ch   SCOMPARE1                      ;-Multiprocessor... vs S32C1I
      16       10h   ACCLO   Accumulator low (32bit)     ;\
      17       11h   ACCHI   Accumulator high (8bit)     ;
      32       20h   MR0     MAC16 register m0 (32bit)   ; MAC16 option
      33       21h   MR1     MAC16 register m1 (32bit)   ;
      34       22h   MR2     MAC16 register m2 (32bit)   ;
      35       23h   MR3     MAC16 register m3 (32bit)   ;/
      177      B1h   EPC[1]  Exception Program Counter   ;\
      232      E8h   EXCAUSE Cause of last Exception     ;
      209      D1h   EXCSAVE[1]                          ;
      230      E6h   PS                                  ; Exception option
      230      E6h   PS.EXCM                             ;
      238      EEH   EXCVADDR                            ;
      192      C0h   DEPC                                ;/
      see            PS.INTLEVEL                         ;-Interrupt option
      178..183 B2h.. EPC[2..7]                    ;\
      194..199 C2h.. EPS[2..7]                    ; High-Priority Interrupt option
      210..215 D2h.. EXCSAVE[2..7]                ;/
      234      EAh   CCOUNT                       ;\Timer Interrupt option
      240-242  F0h   CCOMPARE                     ;/
      -              AR[NAREG]                    ;\
      72       48h   WindowBase                   ; Windowed Register option
      73       49h   WindowStart                  ;
      230      E6h   PS.CALLINC                   ;
      230      E6h   PS.OWB                       ;
      230      E6h   PS.WOE                       ;/
      244-247  F4h.. MISC                         ;-Misc Special Register option
      236      ECh   ICOUNT                       ;\
      237      EDh   ICOUNTLEVEL                  ;
      128-129  80h.. IBREAKA                      ;
      96       60h   IBREAKENABLE                 ; Debug option
      144-145  90h.. DBREAKA                      ;
      160-161  A0h.. DBREAKC                      ;
      233      E9h   DEBUGCAUSE                   ;
      104      68h   DDR                          ;/
      230      E6h   PS.RING                      ;\
      83       53h   PTEVADDR                     ;
      90       5Ah   RASID                        ; MMU option
      91       5Bh   ITLBCFG                      ;
      92       5Ch   DTLBCFG                      ;
      see            ITLB                         ;
      see            DTLB                         ;/
      98       62h   CACHEATTR    ;-
      99       63h   ATOMCTL      ;-
      224      E0h   CPENABLE     ;-
      226      E2h   INTERRUPT (R);\
      226      E2h   INTSET    (W); Interrupt
      227      E3h   INTCLEAR     ;
      228      E4h   INTENABLE    ;/
      106      6Ah   MEPC         ;\
      107      6Bh   MEPS         ;
      108      6Ch   MESAVE       ; Memory ECC/Parity
      109      6Dh   MESR         ;
      110      6Eh   MECR         ;
      111      6Fh   MEVADDR      ;/
      89       59h   MMID         ;-Trace Port
      231      E7h   VECBASE      ;-
      235      EBh   PRID         ;-Processor ID

XSR with >=64 is privileged.
Xtensa User Registers

      0-223    0-DFh Available for designer extensions
      192-255  C0h.. Reserved by Tensilica (conflicts with above "available" info?)
      231      E7h   THREADPTR                      ;-Thread Pointer
      232      E8h   FCR        (float control)     ;\
      233      E9h   FSR        (float status)      ; Float
      -              FR         (f0..f15?)          ;/

DSi Atheros Wifi - Xtensa CPU Core Opcodes

Core Opcodes - Move/Load/Store

      Opcode   Native               Nocash                  Expl.
      ii0st2h  L8UI   at,as,imm     movb   at,[as+imm8]     Load 8bit Unsigned
      ii1st2h  L16UI  at,as,imm*2   movh   at,[as+imm8*2]   Load 16bit Unsigned
      ii9st2h  L16SI  at,as,imm*2   movsh  at,[as+imm8*2]   Load 16bit Signed
      ii2st2h  L32I   at,as,imm*4   mov    at,[as+imm8*4]   Load 32bit
      ii4st2h  S8I    at,as,imm     movb   [as+imm8],at     Store 8bit
      ii5st2h  S16I   at,as,imm*2   movh   [as+imm8*2],at   Store 16bit
      ii6st2h  S32I   at,as,imm*4   mov    [as+imm8*4],at   Store 32bit
      iiiit1h  L32R   at,adr        movp   at,literal       Load 32bit literal pool
      iiAit2h  MOVI   at,imm12      mov    at,+/-imm12      Move Immediate(signed)
      83rst0h  MOVEQZ ar,as,at      movz   at,ar,as         Move if at=0  ;zero
      93rst0h  MOVNEZ ar,as,at      movnz  at,ar,as         Move if at<>0 ;nonzero
      A3rst0h  MOVLTZ ar,as,at      movs   at,ar,as         Move if at<0  ;negative
      B3rst0h  MOVGEZ ar,as,at      movns  at,ar,as         Move if at>=0 ;positive

Core Opcodes - ALU

      Opcode   Native               Nocash                  Expl.
      iiCst2h  ADDI   at,as,imm8    add  at,as,+/-imm8      Add Immediate (signed)
      iiDst2h  ADDMI  at,as,imm     add  at,as,+/-imm8*256  Add Immediate*100h
      80rst0h  ADD    ar,as,at      add  ar,as,at           Add        (as+at)
      90rst0h  ADDX2  ar,as,at      add  ar,at,as*2         Add shift1 (as*2+at)
      A0rst0h  ADDX4  ar,as,at      add  ar,at,as*4         Add shift2 (as*4+at)
      B0rst0h  ADDX8  ar,as,at      add  ar,at,as*8         Add shift3 (as*8+at)
      C0rst0h  SUB    ar,as,at      sub  ar,as,at           Subtract   (as-at)
      D0rst0h  SUBX2  ar,as,at      sub  ar,as*2,at         Sub shift1 (as*2-at)
      E0rst0h  SUBX4  ar,as,at      sub  ar,as*4,at         Sub shift2 (as*4-at)
      F0rst0h  SUBX8  ar,as,at      sub  ar,as*8,at         Sub shift3 (as*8-at)
      60r0t0h  NEG    ar,at         neg  ar,at              Negate
      60r1t0h  ABS    ar,at         abs  ar,at              Absolute Value
      10rst0h  AND    ar,as,at      and  ar,as,at           Bitwise Logical And
      20rst0h  OR     ar,as,at      or   ar,as,at  ;akaMOV  Bitwise Logical Or
      30rst0h  XOR    ar,as,at      xor  ar,as,at           Bitwise Logical Xor

Core Opcodes - Shift

      Opcode   Native               Nocash                  Expl.
      01rsi0h  SLLI   ar,as,32-imm5 shl  ar,as,32-imm5      Shift Left Logical
      21rit0h  SRAI   ar,at,imm5    sar  ar,at,imm5         Shift Right Arithmetic
      41rit0h  SRLI   ar,at,imm4    shr  ar,at,imm4         Shift Right Logical
      m4rst0h  EXTUI  ar,at,s,m     shrmask ar,at,imm5,mask ExtractUnsignedImm
      81rst0h  SRC    ar,as,at      shr  ar,as,at,shiftreg  Shift Right Combined
      91r0t0h  SRL    ar,at         shr  ar,at,shiftreg     Shift Right Logical
      A1rs00h  SLL    ar,as         shl  ar,as,shiftreg ??  Shift Left Logical
      B1r0t0h  SRA    ar,at         sar  ar,at,shiftreg     Shift Right Arithmetic
      400s00h  SSR    as            mov  shiftreg,as        SetShiftAm for RightSh
      401s00h  SSL    as            sub  shiftreg,32,as     SetShiftAm for LeftSh
      402s00h  SSA8L  as            mov  shiftreg,as*8      SetShiftAmFor LE shift
      403s00h  SSA8B  as            sub  shiftreg,32,as*8   SetShiftAmFor BE shift
      404i.0h  SSAI   imm5          mov  shiftreg,imm5sar   SetShiftAm Immediate

Core Opcodes - Jump/Call

      Opcode   Native               Nocash                  Expl.
      iiii06h  J      adr           jmp    rel18            Unconditional Jump
      000sA0h  JX     as            jmp    as               Unconditional Jump Reg
      iiii05h  CALL0  adr           call0  rel18x4          Non-windowed Call
      000sC0h  CALLX0 as            call0  as               Non-windowed Call Reg
      000080h  RET        ;(jx a0)  ret          ;(jx a0)   Non-Windowed Return

Core Opcodes - Conditional Jump

      Opcode   Native               Nocash                  Branch if...
      iiis16h  BEQZ   as,adr        jz     as,rel12         as=0
      iiis56h  BNEZ   as,adr        jnz    as,rel12         as<>0
      iiis96h  BLTZ   as,adr        js     as,rel12         as<0         (signed)
      iiisD6h  BGEZ   as,adr        jns    as,rel12         as>=0        (signed)
      iics26h  BEQI   as,c,adr      je     as,const4,rel8   as=Imm4(c)
      iics66h  BNEI   as,c,adr      jne    as,const4,rel8   as<>Imm4(c)
      iicsA6h  BLTI   as,c,adr      jl     as,const4,rel8   as<Imm4(c)   (signed)
      iicsE6h  BGEI   as,c,adr      jge    as,const4,rel8   as>=Imm4(c)  (signed)
      iicsB6h  BLTUI  as,c,adr      jb     as,const4u,rel8  as<UnsiImm4  (unsigned)
      iicsF6h  BGEUI  as,c,adr      jae    as,const4u,rel8  as>=UnsiImm4 (unsigned)
      ii1st7h  BEQ    as,at,adr     je     as,at,rel8       as=at  equal
      ii9st7h  BNE    as,at,adr     jne    as,at,rel8       as<>at not equal
      ii2st7h  BLT    as,at,adr     jl     as,at,rel8       as<at  less  (signed)
      iiAst7h  BGE    as,at,adr     jge    as,at,rel8       as>=at gt/eq (signed)
      ii3st7h  BLTU   as,at,adr     jb     as,at,rel8       as<at  less  (unsigned)
      iiBst7h  BGEU   as,at,adr     jae    as,at,rel8       as>=at gt/eq (unsigned)
      ii0st7h  BNONE  as,at,adr     tstjz  as,at,rel8       (as AND at)=0  ;none
      ii8st7h  BANY   as,at,adr     tstjnz as,at,rel8       (as AND at)<>0 ;any set
      ii4st7h  BALL   as,at,adr     tstje  as,at,rel8       (as AND at)=at ;all set
      iiCst7h  BNALL  as,at,adr     tstjne as,at,rel8       (as AND at)<>at;not all
      ii5st7h  BBC    as,at,adr     tstjz  as,1 shl at,rel8 (as AND (1 shl at))=0
      ii6sb7h  BBCI   as,b,adr      tstjz  as,1 shl imm5,r8 (as AND (1 shl imm))=0
      iiDst7h  BBS    as,at,adr     tstjnz as,1 shl at,rel8 (as AND (1 shl at))<>0
      iiEsb7h  BBSI   as,b,adr      tstjnz as,1 shl imm5,r8 (as AND (1 shl imm))<>0

Core Opcodes - Misc

      Opcode   Native               Nocash                  Expl.
      406st0h  RER    at,as         mov  at,ext[as]         ReadExternal Register
      407st0h  WER    at,as         mov  ext[as],at         WriteExternalRegister
      03iit0h  RSR    at,imm8       mov  at,special[imm8]   ReadSpecial Register
      13iit0h  WSR    at,imm8       mov  special[imm8],at   WriteSpecialRegister
      61iit0h  XSR    at,imm8       xchg at,special[imm8]   ExchangeSpecialRegister
      002000h  ISYNC                isync                   Instruction Fetch Sync
      002010h  RSYNC                rsync                   Register Read Sync
      002020h  ESYNC                esync                   Execute Synchronize
      002030h  DSYNC                dsync                   Load/Store Synchronize
      0020C0h  MEMW                 memwait                 Memory Wait
      0020D0h  EXTW                 extwait                 External Wait
      0020F0h  NOP                  nop                     No-Operation

Pseudo Opcodes

      MOV    ar,as       Macro (=OR ar,as,as)
      NOP                Alias for "OR An,An,An" (alternate, instead of 0020F0h)
      J.L    adr,as      Macro (J or LiteralLoad+JX)
      BBCI.L as,b,adr    Macro Branch Bit Clear Imm5 LE
      BBSI.L as,b,adr    Macro Branch Bit Set Imm5 LE
      SRLI ar,at,imm5    Alias for "SRLI ar,at,imm4" or EXTUI (when imm5>=16)

More (inofficial) pseudos...

      mov    br,bs       or  br,bs,bs
      mov    br,0        and br,bs,not bs
      mov    br,1        or  br,bs,not bs
      sub    at,as,imm   add at,as,-imm
      mov    sfr_xxx     mov special[imm8]
      alu    ax,...      alu ax,ax,...

DSi Atheros Wifi - Xtensa CPU Optional General Opcodes

Boolean Option

      Opcode   Native               Nocash
      008st0h  ANY4  bt,bs          or     bt,bs..bs+3      Any 4 Booleans True
      009st0h  ALL4  bt,bs          and    bt,bs..bs+3      All 4 Booleans True
      00Ast0h  ANY8  bt,bs          or     bt,bs..bs+7      Any 8 Booleans True
      00Bst0h  ALL8  bt,bs          and    bt,bs..bs+7      All 8 Booleans True
      02rst0h  ANDB  br,bs,bt       and    br,bs,bt         BooleanAnd
      12rst0h  ANDBC br,bs,bt       and    br,bs,not bt     BooleanAndComplement(t)
      22rst0h  ORB   br,bs,bt       or     br,bs,bt         BooleanOr
      32rst0h  ORBC  br,bs,bt       or     br,bs,not bt     BooleanOrComplement(t)
      42rst0h  XORB  br,bs,bt       xor    br,bs,bt         Boolean Xor
      C3rst0h  MOVF  ar,as,bt       movz   bt,ar,as         Move if False
      D3rst0h  MOVT  ar,as,bt       movnz  bt,ar,as         Move if True
      ii0s76h  BF    bs,adr         jz     bs,rel8          Branch if False
      ii1s76h  BT    bs,adr         jnz    bs,rel8          Branch if True

Misc Option

      40Est0h  NSA    at,as         nsa    at,as            Normaliz.ShiftAmount
      40Fst0h  NSAU   at,as         nsau   at,as            Norma.ShiftAmUnsigned
      23rsi0h  SEXT   ar,as,imm     sext   ar,as,imm4+7     Sign Extend 7..22
      33rsi0h  CLAMPS ar,as,imm     clamps ar,as,imm4+7     Signed Clamp minmax
      43rst0h  MIN    ar,as,at      min    ar,as,at         Minimum Value Signed
      53rst0h  MAX    ar,as,at      max    ar,as,at         Maximum Value Signed
      63rst0h  MINU   ar,as,at      minu   ar,as,at         Minimum Value Unsigned
      73rst0h  MAXU   ar,as,at      maxu   ar,as,at         Maximum Value Unsigned

Loop Option

      ii8s76h  LOOP    as,adr       loop    as,rel8abs      Loop
      ii9s76h  LOOPNEZ as,adr       loopnz  as,rel8abs      Loop if NotEqual zero
      iiAs76h  LOOPGTZ as,adr       loopgtz as,rel8abs      Loop if Greater zero

Windowed Code Option

      iiii15h  CALL4   adr          call4   rel18x4         Call RotateWinBy4
      iiii25h  CALL8   adr          call8   rel18x4         Call RotateWinBy8
      iiii35h  CALL12  adr          call12  rel18x4         Call RotateWinBy12
      000sD0h  CALLX4  as           call4   as              Call RegRotateBy4
      000sE0h  CALLX8  as           call8   as              Call RegRotateBy8
      000sF0h  CALLX12 as           call12  as              Call RegRotateBy12
      iiis36h  ENTRY   as,imm*8     entry   as,imm12*8      Subroutine Entry
      000090h  RETW                 retw                    Windowed-Return
      003400h  RFWO                 ret_wo                  RetFromWinOverflow
      003500h  RFWU                 ret_wu                  RetFromWinUnderflw
      001st0h  MOVSP   at,as        movsp   at,as           Move to Stack Ptr
      4080i0h  ROTW    imm4         rotw    imm4            Rotate Window -8..+7
      09ist0h  L32E    at,as,imm    mov_e   at,[as-imm*4]   Load32bitException
      49ist0h  S32E    at,as,imm    mov_e   [as-imm*4],at   StrWinForExcepts

Narrow Code Option

      --ist8h  L32I.N at,as,imm4*4  mov  at,[as+imm4*4]     Load 32bit
      --ist9h  S32I.N at,as,imm4*4  mov  [as+imm4*4],at     Store 32bit
      --rstAh  ADD.N  ar,as,at      add  ar,as,at           Add
      --rsiBh  ADDI.N ar,as,imm4    add  ar,as,imm4         Add Imm (0=-1 or 1..15)
      --is0Ch  MOVI.N as,imm        mov  as,imm7            Move Imm (-32..95)
      --is8Ch  BEQZ.N as,adr        jz   as,rel6abs         Branch if as=0
      --isCCh  BNEZ.N as,adr        jnz  as,rel6abs         Branch if as<>0
      --0stDh  MOV.N  at,as         mov  at,as              Move
      --F00Dh  RET.N     ;(jx a0)   ret        ;jx a0       Non-Windowed Return
      --F01Dh  RETW.N               retw                    Windowed Return
      --F06Dh  ILL.N                ill                     Xcept Illegal Instr.
      --Fi2Dh  BREAK.N imm4         break imm4              Debug Breakpoint
      --F03Dh  NOP.N                nop                     No-Operation

Mul16 Option

      C1rst0h  MUL16U ar,as,at      umul16  ar,as,at        Multiply16bitUnsigned
      D1rst0h  MUL16S ar,as,at      smul16  ar,as,at        Multiply16bitSigned

Mul32 Option

      82rst0h  MULL  ar,as,at       mul     ar,as,at        Multiply Low
      A2rst0h  MULUH ar,as,at       umulhi  ar,as,at        MultiplyUnsignedHigh
      B2rst0h  MULSH ar,as,at       smulhi  ar,as,at        MultiplySignedHigh

Div32 Option

      C2rst0h  QUOU ar,as,at        udiv    ar,as,at        Quotient Unsigned
      D2rst0h  QUOS ar,as,at        sdiv    ar,as,at        Quotient Signed
      E2rst0h  REMU ar,as,at        udivrem ar,as,at        Remainder Unsigned
      F2rst0h  REMS ar,as,at        sdivrem ar,as,at        Remainder Signed

DSi Atheros Wifi - Xtensa CPU Optional Exception/Cache/MMU Opcodes

Interrupt Option

      006it0h  RSIL  at,level       xchg  at,ps,intlevel i  Read/Set IntLevel
      007i00h  WAITI level          waiti ps,intlevel i     Set IntLevel and Wait

High-Priority Interrupt Option

      003i10h  RFI   level          ret_i level             RetFromHiPrioInt

Exception Option

      000000h  ILL                  ill                     Illegal Instruction
      002080h  EXCW                 xceptwait               Exception Wait
      003000h  RFE                  ret_e                   RetFromException
      003100h  RFUE                 ret_ue                  RetFromUserModeExcept
      003200h  RFDE                 ret_de                  RetFromDoubleExcept
      005000h  SYSCALL              syscall                 System Call

Debug Option

      004xy0h  BREAK imm4,imm4      break  imm8             Breakpoint
      F1E000h  RFDO                 ret_do                  RetFromDebugOperat.
      F1Es10h  RFDD    ;s=???       rer_dd imm1             RetFromDebugDispatch

MemECC/Parity Option

      003020h  RFME                 ret_me                  RetFromMemError

No Option

      E3rii0h  RUR ar,imm8          mov    ar,user[imm8]    Read User Register
      F3iit0h  WUR at,imm8          mov    user[imm8],at    WriteUserRegister

Region/MMU Option

      503st0h  RITLB0 at,as         mov    at,itlb0[as]     Read InstTLB Virtual
      507st0h  RITLB1 at,as         mov    at,itlb1[as]     Read InstTLB Translat
      50Bst0h  RDTLB0 at,as         mov    at,dtlb0[as]     Read DataTLB Virtual
      50Fst0h  RDTLB1 at,as         mov    at,dtlb1[as]     Read DataTLB Translat
      504s00h  IITLB  as            inv    itlb[as]         Invalidate InstTLB
      50Cs00h  IDTLB  as            inv    dtlb[as]         Invalidate DataTLB
      505st0h  PITLB  at,as         probe  at,itlb[as]      Probe InstTLB
      50Dst0h  PDTLB  at,as         probe  at,dtlb[as]      Probe DataTLB
      506st0h  WITLB  at,as         mov    itlb[as],at      Write InstTLB Entry
      50Est0h  WDTLB  at,as         mov    dtlb[as],at      Write DataTLB Entry

Multiprocessor Option

      iiBst2h  L32AI at,as,i*4      mov_m at,[as+imm8*4]    Load 32bit Acquire
      iiFst2h  S32RI at,as,imm*4    mov_m [as+imm8*4],at    Store 32bit Release

Multiprocessor Conditional Store Option

      iiEst2h  S32C1I at,as,imm*4   s32c1i at,[as+imm8*4]   CompareCond

Data Cache Option

      i07s82h  DPFL  as,imm4*16     cach_dpfl  [as+imm4*16] PrefetchAndLock *
      i27s82h  DHU   as,imm4*16     cach_dhu   [as+imm4*16] HitUnlock
      i37s82h  DIU   as,imm4*16     cach_diu   [as+imm4*16] Index Unlock
      i47s82h  DIWB  as,imm4*16     cach_diwb  [as+imm4*16] Index Writeback
      i57s82h  DIWBI as,imm4*16     cach_diwbi [as+imm4*16] Index WbInvali.
      ii7s02h  DPFR  as,imm8*4      cach_dpfr  [as+imm8*4]  PrefetchForRead
      ii7s12h  DPFW  as,imm8*4      cach_dpfw  [as+imm8*4]  PrefetchForWrite
      ii7s22h  DPFRO as,imm8*4      cach_dpfro [as+imm8*4]  PrefetchForRdOnce
      ii7s32h  DPFWO as,imm8*4      cach_dpfwo [as+imm8*4]  PrefetchForWrOnce
      ii7s42h  DHWB  as,imm8*4      cach_dhwb  [as+imm8*4]  HitWriteback
      ii7s52h  DHWBI as,imm8*4      cach_dhwbi [as+imm8*4]  HitWritebackInv.
      ii7s62h  DHI   as,imm8*4      cach_dhi   [as+imm8*4]  HitInvalidate
      ii7s72h  DII   as,imm8*4      cach_dii   [as+imm8*4]  Index Invalidate

Instruction Cache Option

      i07sD2h  IPFL as,imm4*16      cach_ipfl  [as+imm4*16] PrefetchAndLock *
      i27sD2h  IHU  as,imm4*16      cach_ihu   [as+imm4*16] Hit Unlock
      i37sD2h  IIU  as,imm4*16      cach_iiu   [as+imm4*16] Index Unlock
      ii7sC2h  IPF  as,imm8*4       cach_ipf   [as+imm8*4]  Prefetch
      ii7sE2h  IHI  as,imm8*4       cach_ihi   [as+imm8*4]  Hit Invalidate
      ii7sF2h  III  as,imm8*4       cach_iii   [as+imm8*4]  Index Invalidate

Data/Instruction Cache Test Options

      F18st0h  LDCT  at,as          cach_mov at,dCachTag[as]  LoadDataCacheTag
      F10st0h  LICT  at,as          cach_mov at,iCachTag[as]  LoadInstCacheTag
      F12st0h  LICW  at,as          cach_mov at,iCachDta[as]  LoadInstCacheWord
      F19st0h  SDCT  at,as          cach_mov dCachTag[as],at  StoreDataCacheTag
      F11st0h  SICT  at,as          cach_mov iCachTag[as],at  StoreInstCacheTag
      F13st0h  SICW  at,as          cach_mov iCachDta[as],at  StoreInstCacheWord

Unknown

      71xxx0h  ACCER ...            accer ...               Unknown/Unspecified

Custom Designer-Defined Opcode Option

      x6xxx0h  CUST ...             cust ...                DesignerDefinedOpcodes

Simcall Option

      005100h  SIMCALL              simcall                 Non-HW Simulator-Call

DSi Atheros Wifi - Xtensa CPU Optional Floating-Point Opcodes

Float Option

      08rst0h  LSX      fr,as,at    f_mov    fr,[as+at]     LoadSingleIndexed
      ii0st3h  LSI      ft,as,imm*4 f_mov    ft,[as+imm8*4] LoadSingleImmediate
      48rst0h  SSX      fr,as,at    f_mov    [as+at],fr     Store Single Indexed
      ii4st3h  SSI      ft,as,imm*4 f_mov    [as+imm8*4],ft Store Single Immedia.
      18rst0h  LSXU     fr,as,at    f_movupd fr,[as+at]     LoadSingleIndexed+Upd
      ii8st3h  LSIU     ft,as,imm*4 f_movupd ft,[as+imm8*4] LoadSingleImm+Update
      58rst0h  SSXU     fr,as,at    f_movupd [as+at],fr     Store Single Indx+Upd
      iiCst3h  SSIU     ft,as,imm*4 f_movupd [as+imm8*4],ft Store Single Imm+Upd.
      0Arst0h  ADD.S    fr,fs,ft    f_add      fr,fs,ft     Add Single
      1Arst0h  SUB.S    fr,fs,ft    f_sub      fr,fs,ft     Subtract Single
      2Arst0h  MUL.S    fr,fs,ft    f_mul      fr,fs,ft     Multipy Single
      4Arst0h  MADD.S   fr,fs,ft    f_muladd   fr,fs,ft     Multiply+Add Single
      5Arst0h  MSUB.S   fr,fs,ft    f_mulsub   fr,fs,ft     Multiply+Sub Single
      8Arsi0h  ROUND.S  ar,fs,imm4  f_round    ar,fs,pow4   Round Single to Fixed
      9Arsi0h  TRUNC.S  ar,fs,imm4  f_trunc    ar,fs,pow4   TruncateSingleToFixed
      EArsi0h  UTRUNC.S ar,fs,imm4  f_utrunc   ar,fs,pow4   UnsignedTruncatetoFix
      AArsi0h  FLOOR.S  ar,fs,imm4  f_floor    ar,fs,pow4   FloorSingleToFixed
      BArsi0h  CEIL.S   ar,fs,imm4  f_ceil     ar,fs,pow4   Ceiling SingleToFixed
      CArsi0h  FLOAT.S  fr,as,imm4  f_float    fr,as,frac4  ConvertFixedToSingle
      DArsi0h  UFLOAT.S fr,as,imm4  f_ufloat   fr,as,frac4  UnsignedFixedToSingle
      FArs00h  MOV.S    fr,fs       f_mov      fr,fs        Move Single
      FArs10h  ABS.S    fr,fs       f_abs      fr,fs        Absolute Value Single
      FArs40h  RFR      ar,fs       f_mov      ar,fs        Move FR to AR
      FArs50h  WFR      fr,as       f_mov      fr,as        Move AR to FR
      FArs60h  NEG.S    fr,fs       f_neg      fr,fs        Negate Single
      1Brst0h  UN.S     br,fs,ft    f_cmp_un   br,fs,ft     CompareSingle Unord
      2Brst0h  OEQ.S    br,fs,ft    f_cmp_oeq  br,fs,ft     CompareSingle Equal
      3Brst0h  UEQ.S    br,fs,ft    f_cmp_ueq  br,fs,ft     CompareSingle UnordEq
      4Brst0h  OLT.S    br,fs,ft    f_cmp_olt  br,fs,ft     CompareSingle OrdLt
      5Brst0h  ULT.S    br,fs,ft    f_cmp_ult  br,fs,ft     CompareSingle UnorLt
      6Brst0h  OLE.S    br,fs,ft    f_cmp_ole  br,fs,ft     CompareSingle OrdLt/Eq
      7Brst0h  ULE.S    br,fs,ft    f_cmp_ule  br,fs,ft     CompareSingle UnorLtEq
      8Brst0h  MOVEQZ.S fr,fs,at    f_movz     at,fr,fs     Move Single if at=0
      9Brst0h  MOVNEZ.S fr,fs,at    f_movnz    at,fr,fs     Move Single if at<>0
      ABrst0h  MOVLTZ.S fr,fs,at    f_movs     at,fr,fs     Move Single if at<0
      BBrst0h  MOVGEZ.S fr,fs,at    f_movns    at,fr,fs     Move Single if at>=0
      CBrst0h  MOVF.S   fr,fs,bt    f_movz     bt,fr,fs     Move Single if bt=0
      DBrst0h  MOVT.S   fr,fs,bt    f_movnz    bt,fr,fs     Move Single if bt=1

pow4: (imm: opcode.bit7..4 = 0..15 aka (1 shl 0..15) aka 1..8000h)
frac4: (imm: opcode.bit7..4 = 0..15 aka (1 shr 0..15) aka 1..1/8000h)

DSi Atheros Wifi - Xtensa CPU Optional MAC16 Opcodes

MAC16 Option

      mw = m0..m3
      mx = m0..m1
      my = m2..m3
      as,at = a0..a15
      acc = special register acchi(8bit):acclo(32bit)
      700st4h  UMUL.AA.LL as,at             umul    acc,as_l,at_l   ;\
      710st4h  UMUL.AA.HL as,at             umul    acc,as_h,at_l   ; Unsigned Mul
      720st4h  UMUL.AA.LH as,at             umul    acc,as_l,at_h   ; acc=as*at
      730st4h  UMUL.AA.HH as,at             umul    acc,as_h,at_h   ;/
      24x0y4h  MUL.DD.LL  mx,my             smul    acc,mx_l,my_l   ;\
      25x0y4h  MUL.DD.HL  mx,my             smul    acc,mx_h,my_l   ; Signed Mul
      26x0y4h  MUL.DD.LH  mx,my             smul    acc,mx_l,my_h   ; acc=mx*my
      27x0y4h  MUL.DD.HH  mx,my             smul    acc,mx_h,my_h   ;/
      340sy4h  MUL.AD.LL  as,my             smul    acc,as_l,my_l   ;\
      350sy4h  MUL.AD.HL  as,my             smul    acc,as_h,my_l   ; Signed Mul
      360sy4h  MUL.AD.LH  as,my             smul    acc,as_l,my_h   ; acc=as*my
      370sy4h  MUL.AD.HH  as,my             smul    acc,as_h,my_h   ;/
      64x0t4h  MUL.DA.LL  mx,at             smul    acc,mx_l,at_l   ;\
      65x0t4h  MUL.DA.HL  mx,at             smul    acc,mx_h,at_l   ; Signed Mul
      66x0t4h  MUL.DA.LH  mx,at             smul    acc,mx_l,at_h   ; acc=mx*at
      67x0t4h  MUL.DA.HH  mx,at             smul    acc,mx_h,at_h   ;/
      740st4h  MUL.AA.LL  as,at             smul    acc,as_l,at_l   ;\
      750st4h  MUL.AA.HL  as,at             smul    acc,as_h,at_l   ; Signed Mul
      760st4h  MUL.AA.LH  as,at             smul    acc,as_l,at_h   ; acc=as*at
      770st4h  MUL.AA.HH  as,at             smul    acc,as_h,at_h   ;/
      28x0y4h  MULA.DD.LL mx,my             smuladd acc,mx_l,my_l   ;\
      29x0y4h  MULA.DD.HL mx,my             smuladd acc,mx_h,my_l   ; Signed MulAdd
      2Ax0y4h  MULA.DD.LH mx,my             smuladd acc,mx_l,my_h   ; acc=acc+mx*my
      2Bx0y4h  MULA.DD.HH mx,my             smuladd acc,mx_h,my_h   ;/
      380sy4h  MULA.AD.LL as,my             smuladd acc,as_l,my_l   ;\
      390sy4h  MULA.AD.HL as,my             smuladd acc,as_h,my_l   ; Signed MulAdd
      3A0sy4h  MULA.AD.LH as,my             smuladd acc,as_l,my_h   ; acc=acc+as*my
      3B0sy4h  MULA.AD.HH as,my             smuladd acc,as_h,my_h   ;/
      68x0t4h  MULA.DA.LL mx,at             smuladd acc,mx_l,at_l   ;\
      69x0t4h  MULA.DA.HL mx,at             smuladd acc,mx_h,at_l   ; Signed MulAdd
      6Ax0t4h  MULA.DA.LH mx,at             smuladd acc,mx_l,at_h   ; acc=acc+mx*at
      6Bx0t4h  MULA.DA.HH mx,at             smuladd acc,mx_h,at_h   ;/
      780st4h  MULA.AA.LL as,at             smuladd acc,as_l,at_l   ;\
      790st4h  MULA.AA.HL as,at             smuladd acc,as_h,at_l   ; Signed MulAdd
      7A0st4h  MULA.AA.LH as,at             smuladd acc,as_l,at_h   ; acc=acc+as*at
      7B0st4h  MULA.AA.HH as,at             smuladd acc,as_h,at_h   ;/
      2Cx0y4h  MULS.DD.LL mx,my             smulsub acc,mx_l,my_l   ;\
      2Dx0y4h  MULS.DD.HL mx,my             smulsub acc,mx_h,my_l   ; Signed MulSub
      2Ex0y4h  MULS.DD.LH mx,my             smulsub acc,mx_l,my_h   ; acc=acc-mx*my
      2Fx0y4h  MULS.DD.HH mx,my             smulsub acc,mx_h,my_h   ;/
      3C0sy4h  MULS.AD.LL as,my             smulsub acc,as_l,my_l   ;\
      3D0sy4h  MULS.AD.HL as,my             smulsub acc,as_h,my_l   ; Signed MulSub
      3E0sy4h  MULS.AD.LH as,my             smulsub acc,as_l,my_h   ; acc=acc-as*my
      3F0sy4h  MULS.AD.HH as,my             smulsub acc,as_h,my_h   ;/
      6Cx0t4h  MULS.DA.LL mx,at             smulsub acc,mx_l,at_l   ;\
      6Dx0t4h  MULS.DA.HL mx,at             smulsub acc,mx_h,at_l   ; Signed MulSub
      6Ex0t4h  MULS.DA.LH mx,at             smulsub acc,mx_l,at_h   ; acc=acc-mx*at
      6Fx0t4h  MULS.DA.HH mx,at             smulsub acc,mx_h,at_h   ;/
      7C0st4h  MULS.AA.LL as,at             smulsub acc,as_l,at_l   ;\
      7D0st4h  MULS.AA.HL as,at             smulsub acc,as_h,at_l   ; Signed MulSub
      7E0st4h  MULS.AA.LH as,at             smulsub acc,as_l,at_h   ; acc=acc-as*at
      7F0st4h  MULS.AA.HH as,at             smulsub acc,as_h,at_h   ;/
      80ws04h  LDINC      mw,as             movupd  mw,[as+4]       ;Load+AutoInc
      90ws04h  LDDEC      mw,as             movupd  mw,[as-4]       ;Load+AutoDec

Below opcodes are doing two separate things:
1. acc=acc+x*y ;Signed MulAdd
2. as=as+/-4, mw=[as] ;Load mw from memory (for use by NEXT opcode)

      08wsy4h  MULA.DD.LL.LDINC mw,as,mx,my smuladd_movupd acc,mx_l,my_l,mw,[as+4]
      09wsy4h  MULA.DD.HL.LDINC mw,as,mx,my smuladd_movupd acc,mx_h,my_l,mw,[as+4]
      0Awsy4h  MULA.DD.LH.LDINC mw,as,mx,my smuladd_movupd acc,mx_l,my_h,mw,[as+4]
      0Bwsy4h  MULA.DD.HH.LDINC mw,as,mx,my smuladd_movupd acc,mx_h,my_h,mw,[as+4]
      18wsy4h  MULA.DD.LL.LDDEC mw,as,mx,my smuladd_movupd acc,mx_l,my_l,mw,[as-4]
      19wsy4h  MULA.DD.HL.LDDEC mw,as,mx,my smuladd_movupd acc,mx_h,my_l,mw,[as-4]
      1Awsy4h  MULA.DD.LH.LDDEC mw,as,mx,my smuladd_movupd acc,mx_l,my_h,mw,[as-4]
      1Bwsy4h  MULA.DD.HH.LDDEC mw,as,mx,my smuladd_movupd acc,mx_h,my_h,mw,[as-4]
      48wst4h  MULA.DA.LL.LDINC mw,as,mx,at smuladd_movupd acc,mx_l,at_l,mw,[as+4]
      49wst4h  MULA.DA.HL.LDINC mw,as,mx,at smuladd_movupd acc,mx_h,at_l,mw,[as+4]
      4Awst4h  MULA.DA.LH.LDINC mw,as,mx,at smuladd_movupd acc,mx_l,at_h,mw,[as+4]
      4Bwst4h  MULA.DA.HH.LDINC mw,as,mx,at smuladd_movupd acc,mx_h,at_h,mw,[as+4]
      58wst4h  MULA.DA.LL.LDDEC mw,as,mx,at smuladd_movupd acc,mx_l,at_l,mw,[as-4]
      59wst4h  MULA.DA.HL.LDDEC mw,as,mx,at smuladd_movupd acc,mx_h,at_l,mw,[as-4]
      5Awst4h  MULA.DA.LH.LDDEC mw,as,mx,at smuladd_movupd acc,mx_l,at_h,mw,[as-4]
      5Bwst4h  MULA.DA.HH.LDDEC mw,as,mx,at smuladd_movupd acc,mx_h,at_h,mw,[as-4]

DSi Atheros Wifi - Xtensa CPU Opcode Encoding Tables

Xtensa Opcodes
Xtensa opcodes are 24bit wide (or 16bit for "narrow" opcodes), the opcodes consist of several 4bit fields (or 2bit, 8bit, 12bit, 16bit, 18bit fields in some cases):

      23-20  19-16  15-12  11-8  7-4   3-0   Type
      op2    op1    r      s     t     op0   RRR
      imm4   op1    r      s     t     op0   RRI4
      imm8--------> r      s     t     op0   RRI8
      imm16------------------->  t     op0   RRI16
      op2    op1    rs-------->  t     op0   RSR
      offset----------------------> n  op0   CALL
      op2    op1    r      s     m  n  op0   CALLX
      imm8--------> r      s     m  n  op0   BRI8
      imm12------------->  s     m  n  op0   BRI8
                    r      s     t     op0   RRRN
                    imm.l  s     imm.h op0   RI7  (bit7="i")
                    imm.l  s     imm.h op0   RI6  (bit7="i", bit6="z")

Xtensa Opcode Root- and Subtables (Summary)
Opcode decoding can be done in 4bit units, starting at the "op0" field, and then decoding further 4bit field(s) depending on the opcode. Decoding speed could be improved by grouping two 4bit fields into a 8bit field (eg. op2 and op1; that won't work out perfectly for all opcodes though).

      ROOT\                        op0
      ROOT\QRST                    op0=0, op1
      ROOT\QRST\RST0               op0=0, op1=0, op2
      ROOT\QRST\RST0\ST0           op0=0, op1=0, op2=0, r
      ROOT\QRST\RST0\ST0\SNM0      op0=0, op1=0, op2=0, r=0, mn
      ROOT\QRST\RST0\ST0\SYNC      op0=0, op1=0, op2=0, r=2, t
      ROOT\QRST\RST0\ST0\RFEI      op0=0, op1=0, op2=0, r=3, t
      ROOT\QRST\RST0\ST0\RFEI\RFET op0=0, op1=0, op2=0, r=3, t=0, s
      ROOT\QRST\RST0\ST1           op0=0, op1=0, op2=4, r
      ROOT\QRST\RST0\TLB           op0=0, op1=0, op2=5, r
      ROOT\QRST\RST0\RT0           op0=0, op1=0, op2=6, s
      ROOT\QRST\RST1               op0=0, op1=1, op2
      ROOT\QRST\RST1\IMP           op0=0, op1=1, op2=F, r
      ROOT\QRST\RST1\IMP\RFDX      op0=0, op1=1, op2=F, r=E, t
      ROOT\QRST\RST2               op0=0, op1=2, op2
      ROOT\QRST\RST3               op0=0, op1=3, op2
      ROOT\QRST\LSCX               op0=0, op1=8, op2
      ROOT\QRST\LSC4               op0=0, op1=9, op2
      ROOT\QRST\FP0                op0=0, op1=A, op2
      ROOT\QRST\FP0\FP1OP          op0=0, op1=A, op2=F, t
      ROOT\QRST\FP1                op0=0, op1=B, op2
      ROOT\LSAI                    op0=2, r
      ROOT\LSAI\CACHE              op0=2, r=7, t
      ROOT\LSAI\CACHE\DCE          op0=2, r=7, t=8, op1
      ROOT\LSAI\CACHE\ICE          op0=2, r=7, t=D, op1
      ROOT\LSCI                    op0=3, r
      ROOT\MAC16                   op0=4, op2
      ROOT\MAC16\MACID             op0=4, op2=0, op1
      ROOT\MAC16\MACCD             op0=4, op2=1, op1
      ROOT\MAC16\MACDD             op0=4, op2=2, op1
      ROOT\MAC16\MACAD             op0=4, op2=3, op1
      ROOT\MAC16\MACIA             op0=4, op2=4, op1
      ROOT\MAC16\MACCA             op0=4, op2=5, op1
      ROOT\MAC16\MACDA             op0=4, op2=6, op1
      ROOT\MAC16\MACAA             op0=4, op2=7, op1
      ROOT\MAC16\MACI              op0=4, op2=8, op1
      ROOT\MAC16\MACC              op0=4, op2=9, op1
      ROOT\CALLN                   op0=5, mn
      ROOT\SI                      op0=6, mn   (and \SI\BZ, \SI\BI0, \SI\BI1)
      ROOT\SI\BI1\B1               op0=6, mn=7, r
      ROOT\B                       op0=7, r
      ROOT\ST2                     op0=C, t
      ROOT\ST3                     op0=D, r
      ROOT\ST3\S3                  op0=D, r=F, t

Xtensa Opcode Root- and Subtables (Complete)
Below is showing the whole opcode "tree", starting with the root table (indexed via op0). Entries with "-->" are referencing to child tables, the other entries are indicating the actual opcodes (or reserved opcodes). The lower-case suffices are somewhat indicating optional opcodes.

        ROOT\             ROOT\QRST         ROOT\QRST\RS      ROOT\QRST\RST0\ST0
        op0               op1               op2               r
      0 --> QRST          --> RST0          --> ST0           --> SNM0
      1 L32R              --> RST1          AND               MOVSP
      2 --> LSAI          --> RST2          OR                --> SYNC
      3 --> LSCIp         --> RST3          XOR               --> RFEIx
      4 --> MAC16d        EXTUI ;\          --> ST1           BREAKx
      5 --> CALLN         EXTUI ;/          --> TLB           SYSCALLx
      6 --> SI            CUST0 ;\          --> RT0           RSILx
      7 --> B             CUST1 ;/          reserved          WAITIx (t=0)
      8 L32I.Nn  ;\       --> LSCXp         ADD               ANY4p
      9 S32I.Nn  ;        --> LSC4          ADDX2             ALL4p
      A ADD.Nn   ; narrow --> FP0f          ADDX4             ANY8p
      B ADDI.Nn  ; 16bit  --> FP1f          ADDX8             ALL8p
      C --> ST2n ;        reserved          SUB               reserved
      D --> ST3n ;/       reserved          SUBX2             reserved
      E reserved          reserved          SUBX4             reserved
      F reserved          reserved          SUBX8             reserved

        ..\RST0\ST0\SNM0  ..\RST0\ST0\SYNC  ..\RST0\ST0\RFEI  ..\ST0\RFEI\RFET
        mn                t                 t                 s
      0 ILL      ;\       ISYNC             --> RFETx         RFEx
      1 reserved ; ILL    RSYNC             RFIx              RFUEx
      2 reserved ;        ESYNC             RFME (s=0)        RFDEx
      3 reserved ;/       DSYNC             reserved          reserved
      4 reserved ;\       reserved          reserved          RFWOw
      5 reserved ; N/A    reserved          reserved          RFWUw
      6 reserved ;        reserved          reserved          reserved
      7 reserved ;/       reserved          reserved          reserved
      8 RET      ;\       EXCW              reserved          reserved
      9 RETWw    ; JR     reserved          reserved          reserved
      A JX       ;        reserved          reserved          reserved
      B reserved ;/       reserved          reserved          reserved
      C CALLX0   ;\       MEMW              reserved          reserved
      D CALLX4w  ; CALLX  EXTW              reserved          reserved
      E CALLX8w  ;        reserved          reserved          reserved
      F CALLX12w ;/       NOP/reserved      reserved          reserved

        ..\RST0\ST1       ..\RST0\TLB       ..\RST0\RT0       ROOT\QRST\RST1
        r                 r                 s                 op2
      0 SSR (t=0)         reserved          NEG               SLLI ;\
      1 SSL (t=0)         reserved          ABS               SLLI ;/
      2 SSA8L (t=0)       reserved          reserved          SRAI ;\
      3 SSA8B (t=0)       RITLB0            reserved          SRAI ;/
      4 SSAI (t=0)        IITLB (t=0)       reserved          SRLI ;-
      5 reserved          PITLB             reserved          reserved
      6 RER               WITLB             reserved          XSR
      7 WER               RITLB1            reserved          --> ACCER (?)
      8 ROTWw (s=0)       reserved          reserved          SRC
      9 reserved          reserved          reserved          SRL (s=0)
      A reserved          reserved          reserved          SLL (t=0)
      B reserved          RDTLB0            reserved          SRA (s=0)
      C reserved          IDTLB (t=0)       reserved          MUL16U
      D reserved          PDTLB             reserved          MUL16S
      E NSAu              WDTLB             reserved          reserved
      F NSAUu             RDTLB1            reserved          --> IMP

        ..\RST1\IMP       ..\RST1\IMP\RFDX  ROOT\QRST\RST2    ROOT\QRST\RST3
        r                 t                 op2               op2
      0 LICT              RFDO (s=0)        ABDBp             RSR
      1 SICT              RFDD (s=0,1)      ANDBCp            WSR
      2 LICW              reserved          ORBp              SEXTu
      3 SICW              reserved          ORBCp             CLAMPSu
      4 reserved          reserved          XORBp             MINu
      5 reserved          reserved          reserved          MAXu
      6 reserved          reserved          reserved          MINUu
      7 reserved          reserved          reserved          MAXUu
      8 LDCT              reserved          MULLi             MOVEQZ
      9 SDCT              reserved          reserved          MOVNEZ
      A reserved          reserved          MULUHi            MOVLTZ
      B reserved          reserved          MULSHi            MOVGEZ
      C reserved          reserved          QUOUi             MOVFp
      D reserved          reserved          QUOSi             MOVTp
      E --> RFDX          reserved          REMUi             RUR
      F reserved          reserved          REMSi             WUR

        ROOT\QRST\LSCX    ROOT\QRST\LSC4    ROOT\QRST\FP0     ROOT\QRST\FP0\FP1OP
        op2               op2               op2               t
      0 LSXf              L32E              ADD.Sf            MOV.Sf
      1 LSXUf             reserved          SUB.Sf            ABS.Sf
      2 reserved          reserved          MUL.Sf            reserved
      3 reserved          reserved          reserved          reserved
      4 SSXf              S32E              MADD.Sf           RFRf
      5 SSXUf             reserved          MSUB.Sf           WFRf
      6 reserved          reserved          reserved          NEG.Sf
      7 reserved          reserved          reserved          reserved
      8 reserved          reserved          ROUND.Sf          reserved
      9 reserved          reserved          TRUNC.Sf          reserved
      A reserved          reserved          FLOOR.Sf          reserved
      B reserved          reserved          CEIL.Sf           reserved
      C reserved          reserved          FLOAT.Sf          reserved
      D reserved          reserved          UFLOAT.Sf         reserved
      E reserved          reserved          UTRUNC.Sf         reserved
      F reserved          reserved          --> FP1OPf        reserved

        ROOT\QRST\FP1     ROOT\LSAI         ROOT\LSAI\CACHE   ..\CACHE\DCE
        op2               r                 t                 op1
      0 reserved          L8UI              DPFRc             DPFLl
      1 UN.Sf             L16UI             DPFWc             reserved
      2 OEQ.Sf            L32I              DPFROc            DHUl
      3 UEQ.Sf            reserved          DPFWOc            DIUl
      4 OLT.Sf            S8I               DHWBc             DIWBc
      5 ULT.Sf            S16I              DHWBIc            DIWBIc
      6 OLE.Sf            S32I              DHIc              reserved
      7 ULE.Sf            --> CACHEc        DIIc              reserved
      8 MOVEQZ.Sf         reserved          --> DCEc          reserved
      9 MOVNEZ.Sf         L16SI             reserved          reserved
      A MOVLTZ.Sf         MOVI              reserved          reserved
      B MOVGEZ.Sf         L32AIy            reserved          reserved
      C MOVF.Sf           ADDI              IPFc              reserved
      D MOVT.Sf           ADDMI             --> ICEc          reserved
      E reserved          S32C1Iy           IHIc              reserved
      F reserved          S32RIy            IIIc              reserved

        ..\CACHE\ICE      ROOT\LSCI         ROOT\CALLN        ROOT\SI
        op1               r                 mn                mn
      0 IPFLl             LSIf              CALL0  ;\         J
      1 reserved          reserved          CALL4  ;          BEQZ
      2 IHUl              reserved          CALL8  ;          BEQI
      3 IIUl              reserved          CALL12 ;/         ENTRYw
      4 reserved          SSIf              CALL0  ;\         J
      5 reserved          reserved          CALL4  ;          BNEZ
      6 reserved          reserved          CALL8  ;          BNEI
      7 reserved          reserved          CALL12 ;/         --> B1
      8 reserved          LSIUf             CALL0  ;\         J
      9 reserved          reserved          CALL4  ;          BLTZ
      A reserved          reserved          CALL8  ;          BLTI
      B reserved          reserved          CALL12 ;/         BLTUI
      C reserved          SSIUf             CALL0  ;\         J
      D reserved          reserved          CALL4  ;          BGEZ
      E reserved          reserved          CALL8  ;          BGEI
      F reserved          reserved          CALL12 ;/         BGEUI

        ROOT\SI\BI1\B1    ROOT\B            ROOT\ST2          ROOT\ST3
        r                 r                 t                 r
      0 BFp               BNONE             MOVI.Nn ;\        MOV.Nn
      1 BTp               BEQ               MOVI.Nn ;         reserved
      2 reserved          BLT               MOVI.Nn ;         reserved
      3 reserved          BLTU              MOVI.Nn ;         reserved
      4 reserved          BALL              MOVI.Nn ;         reserved
      5 reserved          BBC               MOVI.Nn ;         reserved
      6 reserved          BBCI ;\           MOVI.Nn ;         reserved
      7 reserved          BBCI ;/           MOVI.Nn ;/        reserved
      8 LOOP              BANY              BEQZ.Nn ;\        reserved
      9 LOOPNEZ           BNE               BEQZ.Nn ;         reserved
      A LOOPGTZ           BGE               BEQZ.Nn ;         reserved
      B reserved          BGEU              BEQZ.Nn ;/        reserved
      C reserved          BNALL             BNEZ.Nn ;\        reserved
      D reserved          BBS               BNEZ.Nn ;         reserved
      E reserved          BBSI ;\           BNEZ.Nn ;         reserved
      F reserved          BBSI ;/           BNEZ.Nn ;/        --> S3

        ROOT\ST3\S3       ROOT\MAC16        ROOT\MAC16\MACI   ROOT\MAC16\MACC
        t                 op2               op1               op1
      0 RET.Nn            --> MACID         LDINC             LDDEC
      1 RETW.Nwn          --> MACCD         reserved          reserved
      2 BREAK.Nn          --> MACDD         reserved          reserved
      3 NOP.Nn            --> MACAD         reserved          reserved
      4 reserved          --> MACIA         reserved          reserved
      5 reserved          --> MACCA         reserved          reserved
      6 ILL.Nn            --> MACDA         reserved          reserved
      7 reserved          --> MACAA         reserved          reserved
      8 reserved          --> MACI          reserved          reserved
      9 reserved          --> MACC          reserved          reserved
      A reserved          reserved          reserved          reserved
      B reserved          reserved          reserved          reserved
      C reserved          reserved          reserved          reserved
      D reserved          reserved          reserved          reserved
      E reserved          reserved          reserved          reserved
      F reserved          reserved          reserved          reserved

        ROOT\MAC16\MACID  ROOT\MAC16\MACCD  ROOT\MAC16\MACIA  ROOT\MAC16\MACCA
        op1               op1               op1               op1
      0 reserved          reserved          reserved          reserved
      1 reserved          reserved          reserved          reserved
      2 reserved          reserved          reserved          reserved
      3 reserved          reserved          reserved          reserved
      4 reserved          reserved          reserved          reserved
      5 reserved          reserved          reserved          reserved
      6 reserved          reserved          reserved          reserved
      7 reserved          reserved          reserved          reserved
      8 MULA.DD.LL.LDINC  MULA.DD.LL.LDDEC  MULA.DA.LL.LDINC  MULA.DA.LL.LDDEC
      9 MULA.DD.HL.LDINC  MULA.DD.HL.LDDEC  MULA.DA.HL.LDINC  MULA.DA.HL.LDDEC
      A MULA.DD.LH.LDINC  MULA.DD.LH.LDDEC  MULA.DA.LH.LDINC  MULA.DA.LH.LDDEC
      B MULA.DD.HH.LDINC  MULA.DD.HH.LDDEC  MULA.DA.HH.LDINC  MULA.DA.HH.LDDEC
      C reserved          reserved          reserved          reserved
      D reserved          reserved          reserved          reserved
      E reserved          reserved          reserved          reserved
      F reserved          reserved          reserved          reserved

        ROOT\MAC16\MACDD  ROOT\MAC16\MACAD  ROOT\MAC16\MACDA  ROOT\MAC16\MACAA
        op1               op1               op1               op1
      0 reserved          reserved          reserved          UMUL.AA.LL
      1 reserved          reserved          reserved          UMUL.AA.HL
      2 reserved          reserved          reserved          UMUL.AA.LH
      3 reserved          reserved          reserved          UMUL.AA.HH
      4 MUL.DD.LL         MUL.AD.LL         MUL.DA.LL         MUL.AA.LL
      5 MUL.DD.HL         MUL.AD.HL         MUL.DA.HL         MUL.AA.HL
      6 MUL.DD.LH         MUL.AD.LH         MUL.DA.LH         MUL.AA.LH
      7 MUL.DD.HH         MUL.AD.HH         MUL.DA.HH         MUL.AA.HH
      8 MULA.DD.LL        MULA.AD.LL        MULA.DA.LL        MULA.AA.LL
      9 MULA.DD.HL        MULA.AD.HL        MULA.DA.HL        MULA.AA.HL
      A MULA.DD.LH        MULA.AD.LH        MULA.DA.LH        MULA.AA.LH
      B MULA.DD.HH        MULA.AD.HH        MULA.DA.HH        MULA.AA.HH
      C MULS.DD.LL        MULS.AD.LL        MULS.DA.LL        MULS.AA.LL
      D MULS.DD.HL        MULS.AD.HL        MULS.DA.HL        MULS.AA.HL
      E MULS.DD.LH        MULS.AD.LH        MULS.DA.LH        MULS.AA.LH
      F MULS.DD.HH        MULS.AD.HH        MULS.DA.HH        MULS.AA.HH

DSi Atheros Wifi - Internal Memory Map

Overall Memory Map (Internal Xtensa memory)
Internal Memory contains I/O Ports, ROM, and RAM. Arranged as so:

      00000000h  I/O Ports
      000E0000h  ROM        ;\as so on AR6002 (other AR60xx chips may use
      00100000h  RAM        ;/slightly different addresses).

The whole memory is repeated every 400000h bytes (4MByte), this is just dumb mirroring (although Atheros is referring to it as "virtual memory"). The first three mirrors (in first 12Mbytes) are commonly used as so:

      00000000h..003FFFFh  used for I/O Port read/write             ;1st mirror
      00400000h..007FFFFh  used for ROM and RAM data read/write     ;2nd mirror
      00800000h..00BFFFFh  used for ROM and RAM opcode read         ;3rd mirror
      00C00000h..FFFFFFFh  normally unused                          ;4th..1024th

Unknown how far it is really required to use the mirrors that way. The different areas might be related to different access rights, or caching (although the AR6002/AR6003/AR6004 chips don't have any cache at all).
The AR6002 BIOS does usually read ROM data from 4E0000h..4F3FFFh, however, in one case it's accidently reading ROM data from 8EEFF8h..8EF73Bh, so that's apparently possible & working, too.
Using WINDOW_DATA to read memory works well for address 00000000h..FFFFFFFFh (apart from some dangerous read-locations in the I/O area; as well as mirrors of those I/O locations).
RAM/ROM address/size, IDs, and various stuff for different chips

      AR60xx chip name    AR6002    AR6003    AR6004    AR6013    AR6014
      AR6002_rev alias    REV2      REV4      REV6      REV2      REV2
      hw name             hw2       hw4       hw6       hw2       hw2
      Nintendo DSi/3DS    Old DSi   N/A       N/A       New DSi   3DS/New3DS
      Wifi Board          DWM-W015  N/A       N/A       DWM-W024  DWM-W028
      SPI FLASH ID Byte   01h       N/A       N/A       02h       03h
      SPI FLASH Size      4 or 128K N/A       N/A       4K        4K
      I2C EEPROM SizeUsed 300h      ?         ?         300h      300h
      ROM Size (Kbyte)    80K       256K      512K      256K      256K
      RAM Size (Kbyte)    184K      256K      256-288K? 128K      128K
      IRAM Size (Kbyte)   N/A       N/A       160K?     N/A       N/A
      ROM Date            23nov2007 ?         ?         18jul2008 25jun2009
      ROM ID version      2.0.0.392 ?         ?         2.3.0.36  2.3.0.111
      Firmware version    2.1.0.123 ?         ?         2.3.0.108 2.3.0.179+
      ROM Base            0E0000h   0E0000h   100000h   0E0000h   0E0000h
      ROM Reset Entry     8E0000h   ?         ?         8E0000h   8E0000h
      RAM Base            100000h   140000h?  000000h?? 120000h   120000h
      RAM Host Interest   500400h   540600h   400600h?? 520000h   520000h
      RAM Start of Free   502400h   ?         ?         524C00h   524C00h
      RAM BMI_DONE Entry  915000h   ?         ?         927000h   927000h
      CPU Litbase         52F000h+1 ?         ?         54C000h+1 54C000h+1
      IRAM Base           N/A       N/A       998000h   N/A       N/A
      ROM Size (hex)      14000h    40000h    80000h    40000h    40000h
      RAM Size (hex)      2E000h    40000h    4xxxxh?   20000h    20000h
      ROM ID hex          20000188h ?         ?         23000024h 2300006Fh
      Firm ID hex         2100007Bh ?         ?         2300006Ch 230000B3h+
      CHIP_ID used        02000001h ?         ?         0D000000h 0D000001h
      CHIP_ID alternate?  02010001h ?         ?         0D00000xh ?
      BB_D2_CHIP_ID       has any?  ?         ?         has any?  has any?
      SDIO MANFID         02000271h ?         ?         02010271h 02010271h
      OSC                 26MHz     ?         ?         40MHz     40MHz

Special ROM Addresses
There are only a few ROM locations with fixed/standarized addresses:

      Entrypoint:        ROM_Base+0
      Exception Vectors: ROM_Base+xxx ?
      DataSet Address:   ROM_Base+ROM_Size-8
      MBIST Cksum:       ROM_Base+ROM_Size-4  ;MBIST = memory built-in-self-test ?

The firmware may call ROM functions, but the firmware code must be matched to specific ROM versions: There is some call table in RAM, allowing to call (or change) function vectors, but the table's location/indices vary for different ROM versions. The RAM table doesn't contain entries for all ROM functions though, so the firmware must use hardcoded addresses (like "8E35A0h") for functions that aren't in the table.
Note that it's possible to patch ROM via TCAM/BCAM registers.
Special RAM Addresses
The first some kilobytes of RAM contain stuff like stack, call table, variables, and host interest area (but the exact addresses of that regions depend on the ROM version).
The remaining RAM could be more or less freely used by the firmware (whereas, one should probably use ROM's memory allocation function for that purpose).
The CPU's "litbase" is dictacted by the ROM, so the firmware must adapt its literal pool offsets to that value. The default BMI_DONE entrypoint is also dictated by the ROM (although one could override it if neccessary).
Hardware I/O Addresses
The hardware I/O addresses are defined in source code folder "include\AR6002\hw*". Whereas, the folder is called "AR6002", but it does also contain defintions for AR6003 and AR6004. In a similar fashion, the source code does also contain definitions like AR6002_REVn, whereas some of that "AR6002 revisions" are actually referring to AR6003 and AR6004. The naming scheme appears to be as so:

      AR6002 = AR6002_REV2 = include\AR6002\hw2.0
      AR6003 = AR6002_REV4 = include\AR6002\hw4.0
      AR6004 = AR6002_REV6 = include\AR6002\hw6.0

The above folders are included in all source code versions (newer atheros code from 2010 is definetly no longer compatible with the DSi's AR6002 firmware, however, concerning the hardware definitions, the "hw2.0" folder appears to have stayed intact and should be still compatible with real hardware, even in newer source code versions).
However, there are at least two different "hw4.0" versions, the newer one containing some additional registers, and some changed register addresses. There's also some AR6002_REV42 definition in some files, which might be related to that "hw4.0" variant. Current theory would be that "hw4.0" means AR6003, and the newer "hw4.0" should be actually "hw4.2" and means some different chip with unknown name. Or whatever.
There's also a "include\AR6002\hw" folder, this is just some useless dupe, containing the exact same files as "include\AR6002\hw2.0".
There's also something called "MCKINLEY", which seems to same (or similar) as "AR6004".
The actual files in the above folders are containing some very ugly bloated auto-generated definitions, definetly not suitable for human reading (except by using some software parser for extracting relevant definitions).

DSi Atheros Wifi - Internal I/O Map Summary (hw2)

Overall Summary (hw2.0)

      004000h 1C4h    Clock/RTC Registers (rtc_reg.h) (hw2.0)
      008000h 208h    Memory Controller (TCAM) (vmc_reg.h) (hw2.0)
      00C000h 40h     Serial UART (uart_reg.h) (hw2.0)
      010000h 18h     Serial I2C/SPI Interface (si_reg.h) (hw2.0)
      0140F4h 4       GPIO Registers (gpio_reg.h) (hw2.0)
      018000h 114h    MBOX Registers (mbox_reg.h) (hw2.0)
      01A000h 2000h   HOST_IF_WINDOW (mbox_reg.h) (hw2.0)
      01C000h 64h     Analog Intf Registers (analog_reg.h) (hw2.0)
      01C080h 10h     Analog Intf Registers (analog_intf_reg.h) (hw2.0)
      020000h ?       MAC DMA maybe, if any ?
      028000h 1800h   MAC PCU Registers (mac_pcu.h) (hw2.0)
      029800h ...     BB/LC maybe...
      029800h ?       Used in hw2, but undocumented... maybe BASEBAND_0 alike hw4?
      02A000h ?       Used in hw2, but undocumented... maybe BASEBAND_1 alike hw4?
      030000h ?       Used in hw2, but undocumented... maybe RDMA or EFUSE or so?

Clock/RTC Registers (rtc_reg.h) (hw2.0)

      004000h 4       (WLAN_)RESET_CONTROL
      004004h 4       (WLAN_)XTAL_CONTROL
      004008h 4       (WLAN_)TCXO_DETECT
      00400Ch 4       (WLAN_)XTAL_TEST
      004010h 4       (WLAN_)QUADRATURE
      004014h 4       (WLAN_)PLL_CONTROL
      004018h 4       (WLAN_)PLL_SETTLE
      00401Ch 4       (WLAN_)XTAL_SETTLE
      004020h 4       (WLAN_)CPU_CLOCK
      004024h 4       (WLAN_)CLOCK_OUT
      004028h 4       (WLAN_)CLOCK_CONTROL
      00402Ch 4       (WLAN_)BIAS_OVERRIDE
      004030h 4       (WLAN_)WDT_CONTROL            ;\
      004034h 4       (WLAN_)WDT_STATUS             ;
      004038h 4       (WLAN_)WDT                    ; Watchdog Timer
      00403Ch 4       (WLAN_)WDT_COUNT              ;
      004040h 4       (WLAN_)WDT_RESET              ;/
      004044h 4       (WLAN_)INT_STATUS             ;-Interrupt Status
      004048h 4       (WLAN_)LF_TIMER0              ;\
      00404Ch 4       (WLAN_)LF_TIMER_COUNT0        ; Low-Freq Timer
      004050h 4       (WLAN_)LF_TIMER_CONTROL0      ;
      004054h 4       (WLAN_)LF_TIMER_STATUS0       ;/
      004058h 4       (WLAN_)LF_TIMER1              ;\
      00405Ch 4       (WLAN_)LF_TIMER_COUNT1        ; Low-Freq Timer
      004060h 4       (WLAN_)LF_TIMER_CONTROL1      ;
      004064h 4       (WLAN_)LF_TIMER_STATUS1       ;/
      004068h 4       (WLAN_)LF_TIMER2              ;\
      00406Ch 4       (WLAN_)LF_TIMER_COUNT2        ; Low-Freq Timer
      004070h 4       (WLAN_)LF_TIMER_CONTROL2      ;
      004074h 4       (WLAN_)LF_TIMER_STATUS2       ;/
      004078h 4       (WLAN_)LF_TIMER3              ;\
      00407Ch 4       (WLAN_)LF_TIMER_COUNT3        ; Low-Freq Timer
      004080h 4       (WLAN_)LF_TIMER_CONTROL3      ;
      004084h 4       (WLAN_)LF_TIMER_STATUS3       ;/
      004088h 4       (WLAN_)HF_TIMER               ;\
      00408Ch 4       (WLAN_)HF_TIMER_COUNT         ; High-Freq Timer
      004090h 4       (WLAN_)HF_LF_COUNT      ;<--  ;
      004094h 4       (WLAN_)HF_TIMER_CONTROL       ;
      004098h 4       (WLAN_)HF_TIMER_STATUS        ;/
      00409Ch 4       (WLAN_)RTC_CONTROL            ;\
      0040A0h 4       (WLAN_)RTC_TIME               ;
      0040A4h 4       (WLAN_)RTC_DATE               ;
      0040A8h 4       (WLAN_)RTC_SET_TIME           ; Real-Time Clock
      0040ACh 4       (WLAN_)RTC_SET_DATE           ;
      0040B0h 4       (WLAN_)RTC_SET_ALARM          ;
      0040B4h 4       (WLAN_)RTC_CONFIG             ;
      0040B8h 4       (WLAN_)RTC_ALARM_STATUS       ;/
      0040BCh 4       (WLAN_)UART_WAKEUP
      0040C0h 4       (WLAN_)RESET_CAUSE
      0040C4h 4       (WLAN_)SYSTEM_SLEEP
      0040C8h 4       (WLAN_)SDIO_WRAPPER
      0040CCh 4       (WLAN_)MAC_SLEEP_CONTROL
      0040D0h 4       (WLAN_)KEEP_AWAKE
      0040D4h 4       (WLAN_)LPO_CAL_TIME                 ;\
      0040D8h 4       (WLAN_)LPO_INIT_DIVIDEND_INT        ;
      0040DCh 4       (WLAN_)LPO_INIT_DIVIDEND_FRACTION   ;
      0040E0h 4       (WLAN_)LPO_CAL                      ;
      0040E4h 4       (WLAN_)LPO_CAL_TEST_CONTROL         ;
      0040E8h 4       (WLAN_)LPO_CAL_TEST_STATUS          ;/
      0040ECh 4       (WLAN_)CHIP_ID
      0040F0h 4       (WLAN_)DERIVED_RTC_CLK
      0040F4h 4       MAC_PCU_SLP32_MODE
      0040F8h 4       MAC_PCU_SLP32_WAKE
      0040FCh 4       MAC_PCU_SLP32_INC
      004100h 4       MAC_PCU_SLP_MIB1
      004104h 4       MAC_PCU_SLP_MIB2
      004108h 4       MAC_PCU_SLP_MIB3
      00410Ch 4       MAC_PCU_SLP_BEACON          ;<-- hw2.0 only (not hw4.0)
      004110h 4       (WLAN_)POWER_REG            ;\located here in hw2.0
      004114h 4       (WLAN_)CORE_CLK_CTRL        ;/
      004118h 1x8     PAD0                        ;\
      004120h 4x8     SDIO_SETUP_CIRCUIT[8]       ;
      004140h 4       SDIO_SETUP_CONFIG           ;
      004144h 4       CPU_SETUP_CONFIG            ; hw2.0 only (not hw4.0)
      004148h 1x24    PAD1                        ;
      004160h 4x8     CPU_SETUP_CIRCUIT[8]        ;
      004180h 4       BB_SETUP_CONFIG             ;
      004184h 1x28    PAD2                        ;
      0041A0h 4x8     BB_SETUP_CIRCUIT[8]         ;/
      0041C0h 4       (WLAN_)GPIO_WAKEUP_CONTROL  ;-located here in hw2.0

Memory Controller (vmc_reg.h) (hw2.0)

      008000h 4x32    (WLAN_)MC_TCAM_VALID[0..31]         ;\
      008080h 4x32    (WLAN_)MC_TCAM_MASK[0..31]          ; ROM Patches
      008100h 4x32    (WLAN_)MC_TCAM_COMPARE[0..31]       ;
      008180h 4x32    (WLAN_)MC_TCAM_TARGET[0..31]        ;/
      008200h 4       (WLAN_)ADDR_ERROR_CONTROL           ;\ADDR_ERROR
      008204h 4       (WLAN_)ADDR_ERROR_STATUS            ;/

Serial UART (uart_reg.h) (hw2.0)

      00C000h 4       (WLAN_UART_)RBR  - RX Data FIFO (R)           (when DLAB=0)
      00C000h 4       (WLAN_UART_)THR  - TX Data FIFO (W)           (when DLAB=0)
      00C000h 4       (WLAN_UART_)DLL  - Baudrate Divisor LSB (R/W) (when DLAB=1)
      00C004h 4       (WLAN_UART_)IER  - Interrupt Control (R/W)    (when DLAB=0)
      00C004h 4       (WLAN_UART_)DLH  - Baudrate Divisor MSB (R/W) (when DLAB=1)
      00C008h 4       (WLAN_UART_)IIR  - Interrupt Status (R)
      00C008h 4       (WLAN_UART_)FCR  - FIFO Control (W)
      00C00Ch 4       (WLAN_UART_)LCR  - Character Format Control (R/W)
      00C010h 4       (WLAN_UART_)MCR  - Handshaking Control (R/W)
      00C014h 4       (WLAN_UART_)LSR  - RX/TX Status (R) (W=don't do)
      00C018h 4       (WLAN_UART_)MSR  - Handshaking Status (R) (W=don't do)
      00C01Ch 4       (WLAN_UART_)SCR  - Scratch (R/W)
      00C020h 4       (WLAN_UART_)SRBR - (mirror of RBR?)          (when DLAB=0?)
      00C024h 1x4     PAD0
      00C028h 4       (WLAN_UART_)SIIR - (mirror or IIR?)
      00C02Ch 4       (WLAN_UART_?)MWR - Whatever "M Write Register?"
      00C030h 1x4     PAD1
      00C034h 4       (WLAN_UART_)SLSR - (mirror or LSR?) <-- used by AR6002 ROM
      00C038h 4       (WLAN_UART_)SMSR - (mirror of MSR?)
      00C03Ch 4       (WLAN_UART_?)MRR - Whatever "M Read Register?"

Serial I2C/SPI Interface (si_reg.h) (hw2.0)

      010000h 4       SI_CONFIG
      010004h 4       SI_CS
      010008h 4       SI_TX_DATA0
      01000Ch 4       SI_TX_DATA1
      010010h 4       SI_RX_DATA0
      010014h 4       SI_RX_DATA1

GPIO Registers (gpio_reg.h) (hw2.0)

      014000h 4       (WLAN_)GPIO_OUT          ;\GPIO Output Data
      014004h 4       (WLAN_)GPIO_OUT_W1TS     ; (direct, and Write-1-To-Set/Clr)
      014008h 4       (WLAN_)GPIO_OUT_W1TC     ;/
      01400Ch 4       (WLAN_)GPIO_ENABLE       ;\GPIO Output Enable
      014010h 4       (WLAN_)GPIO_ENABLE_W1TS  ; (direct, and Write-1-To-Set/Clr)
      014014h 4       (WLAN_)GPIO_ENABLE_W1TC  ;/
      014018h 4       (WLAN_)GPIO_IN           ;-GPIO Input
      01401Ch 4       (WLAN_)GPIO_STATUS       ;\GPIO Interrupt Status
      014020h 4       (WLAN_)GPIO_STATUS_W1TS  ; (direct, and Write-1-To-Set/Clr)
      014024h 4       (WLAN_)GPIO_STATUS_W1TC  ;/
      014028h 4       (WLAN_)GPIO_PIN0   ;GPIO0  Bluetooth coex BT_PRIORITY
      01402Ch 4       (WLAN_)GPIO_PIN1   ;GPIO1  Bluetooth coex WLAN_ACTIVE
      014030h 4       (WLAN_)GPIO_PIN2   ;GPIO2  Bluetooth coex BT_FREQ    ;I2C SCL
      014034h 4       (WLAN_)GPIO_PIN3   ;GPIO3  Bluetooth coex BT_ACTIVE  ;I2C SDA
      014038h 4       (WLAN_)GPIO_PIN4   ;GPIO4  SDIO/GSPI interface select
      01403Ch 4       (WLAN_)GPIO_PIN5   ;GPIO5  SDIO/GSPI interface select
      014040h 4       (WLAN_)GPIO_PIN6   ;GPIO6  -
      014044h 4       (WLAN_)GPIO_PIN7   ;GPIO7  TRST for JTAG debug
      014048h 4       (WLAN_)GPIO_PIN8   ;GPIO8  external 32kHz clock in
      01404Ch 4       (WLAN_)GPIO_PIN9   ;GPIO9  I2C SCL  or SPI CLK
      014050h 4       (WLAN_)GPIO_PIN10  ;GPIO10 I2C SDA  or SPI MISO
      014054h 4       (WLAN_)GPIO_PIN11  ;GPIO11 UART RXD or SPI MOSI
      014058h 4       (WLAN_)GPIO_PIN12  ;GPIO12 UART TXD or SPI /CS
      01405Ch 4       (WLAN_)GPIO_PIN13  ;GPIO13 Reset in for JTAG debug
      014060h 4       (WLAN_)GPIO_PIN14  ;GPIO14 UART CTS
      014064h 4       (WLAN_)GPIO_PIN15  ;GPIO15 UART RTS
      014068h 4       (WLAN_)GPIO_PIN16  ;GPIO16 -
      01406Ch 4       (WLAN_)GPIO_PIN17  ;GPIO17 -
      014070h 4       SDIO_PIN    - Config: Pad Pull/Strength
      014074h 4       CLK_REQ_PIN - Config: Pad Pull/Strength/AteOeLow
      014078h 4       (WLAN_)SIGMA_DELTA
      01407Ch 4       (WLAN_)DEBUG_CONTROL
      014080h 4       (WLAN_)DEBUG_INPUT_SEL
      014084h 4       (WLAN_)DEBUG_OUT
      014088h 4       LA_CONTROL
      01408Ch 4       LA_CLOCK
      014090h 4       LA_STATUS
      014094h 4       LA_TRIGGER_SAMPLE
      014098h 4       LA_TRIGGER_POSITION
      01409Ch 4       LA_PRE_TRIGGER
      0140A0h 4       LA_POST_TRIGGER
      0140A4h 4       LA_FILTER_CONTROL
      0140A8h 4       LA_FILTER_DATA
      0140ACh 4       LA_FILTER_WILDCARD
      0140B0h 4       LA_TRIGGERA_DATA
      0140B4h 4       LA_TRIGGERA_WILDCARD
      0140B8h 4       LA_TRIGGERB_DATA
      0140BCh 4       LA_TRIGGERB_WILDCARD
      0140C0h 4       LA_TRIGGER
      0140C4h 4       LA_FIFO
      0140C8h 4x2     LA[0..1]
      0140D0h 4       ANT_PIN     - Config: Pad Pull/Strength
      0140D4h 4       ANTD_PIN    - Config: Pad Pull
      0140D8h 4       GPIO_PIN    - Config: Pad Pull/Strength
      0140DCh 4       GPIO_H_PIN  - Config: Pad Pull
      0140E0h 4       BT_PIN      - Config: Pad Pull/Strength
      0140E4h 4       BT_WLAN_PIN - Config: Pad Pull
      0140E8h 4       SI_UART_PIN - Config: Pad Pull/Strength
      0140ECh 4       CLK32K_PIN  - Config: Pad Pull
      0140F0h 4       (WLAN_)RESET_TUPLE_STATUS

MBOX Registers (mbox_reg.h) (hw2.0)

      018000h 4x4     (WLAN_)MBOX_FIFO[0..3]
      018010h 4       (WLAN_)MBOX_FIFO_STATUS
      018014h 4       (WLAN_)MBOX_DMA_POLICY
      018018h 4       (WLAN_)MBOX0_DMA_RX_DESCRIPTOR_BASE   ;\
      01801Ch 4       (WLAN_)MBOX0_DMA_RX_CONTROL           ; MBOX 0
      018020h 4       (WLAN_)MBOX0_DMA_TX_DESCRIPTOR_BASE   ;
      018024h 4       (WLAN_)MBOX0_DMA_TX_CONTROL           ;/
      018028h 4       (WLAN_)MBOX1_DMA_RX_DESCRIPTOR_BASE   ;\
      01802Ch 4       (WLAN_)MBOX1_DMA_RX_CONTROL           ; MBOX 1
      018030h 4       (WLAN_)MBOX1_DMA_TX_DESCRIPTOR_BASE   ;
      018034h 4       (WLAN_)MBOX1_DMA_TX_CONTROL           ;/
      018038h 4       (WLAN_)MBOX2_DMA_RX_DESCRIPTOR_BASE   ;\
      01803Ch 4       (WLAN_)MBOX2_DMA_RX_CONTROL           ; MBOX 2
      018040h 4       (WLAN_)MBOX2_DMA_TX_DESCRIPTOR_BASE   ;
      018044h 4       (WLAN_)MBOX2_DMA_TX_CONTROL           ;/
      018048h 4       (WLAN_)MBOX3_DMA_RX_DESCRIPTOR_BASE   ;\
      01804Ch 4       (WLAN_)MBOX3_DMA_RX_CONTROL           ; MBOX 3
      018050h 4       (WLAN_)MBOX3_DMA_TX_DESCRIPTOR_BASE   ;
      018054h 4       (WLAN_)MBOX3_DMA_TX_CONTROL           ;/
      018058h 4       (WLAN_)MBOX_INT_STATUS                ;\Interrupt
      01805Ch 4       (WLAN_)MBOX_INT_ENABLE                ;/
      018060h 4       (WLAN_)INT_HOST
      018064h 1x28    PAD0
      018080h 4x8     (WLAN_)LOCAL_COUNT[0..7]
      0180A0h 4x8     (WLAN_)COUNT_INC[0..7]
      0180C0h 4x8     (WLAN_)LOCAL_SCRATCH[0..7]
      0180E0h 4       (WLAN_)USE_LOCAL_BUS
      0180E4h 4       (WLAN_)SDIO_CONFIG
      0180E8h 4       (WLAN_)MBOX_DEBUG
      0180ECh 4       (WLAN_)MBOX_FIFO_RESET
      0180F0h 4x4     (WLAN_)MBOX_TXFIFO_POP[0..3]
      018100h 4x4     (WLAN_)MBOX_RXFIFO_POP[0..3]
      018110h 4       (WLAN_)SDIO_DEBUG
      018114h 1x7916  PAD1
      01A000h 4x2048  (WLAN_)HOST_IF_WINDOW[0..2047]

Analog Intf Registers (analog_reg.h) (hw2.0)

      01C000h 4       SYNTH_SYNTH1        ;\
      01C004h 4       SYNTH_SYNTH2        ;
      01C008h 4       SYNTH_SYNTH3        ;
      01C00Ch 4       SYNTH_SYNTH4        ; also defined in "synth_reg.h"
      01C010h 4       SYNTH_SYNTH5        ;
      01C014h 4       SYNTH_SYNTH6        ;
      01C018h 4       SYNTH_SYNTH7        ;
      01C01Ch 4       SYNTH_SYNTH8        ;/
      01C020h 4       RF5G_RF5G1          ;\also defined in "rf5G_reg.h"
      01C024h 4       RF5G_RF5G2          ;/
      01C028h 4       RF2G_RF2G1          ;\also defined in "rf2G_reg.h"
      01C02Ch 4       RF2G_RF2G2          ;/
      01C030h 4       TOP_GAIN            ;\also defined in "top_reg.h"
      01C034h 4       TOP_TOP             ;/
      01C038h 4       BIAS_BIAS_SEL       ;\
      01C03Ch 4       BIAS_BIAS1          ; also defined in "bias_reg.h"
      01C040h 4       BIAS_BIAS2          ;
      01C044h 4       BIAS_BIAS3          ;/
      01C048h 4       TXPC_TXPC           ;\also defined in "txpc_reg.h"
      01C04Ch 4       TXPC_MISC           ;/
      01C050h 4       RXTXBB_RXTXBB1      ;\
      01C054h 4       RXTXBB_RXTXBB2      ; also defined in "rxtxbb_reg.h"
      01C058h 4       RXTXBB_RXTXBB3      ;
      01C05Ch 4       RXTXBB_RXTXBB4      ;/
      01C060h 4       ADDAC_ADDAC1        ;-also defined in "addac.h"
      01C064h 1x1Ch   -

More Analog Intf Registers (analog_intf_reg.h) (hw2.0)

      01C080h 4       SW_OVERRIDE         ;\
      01C084h 4       SIN_VAL             ; defined ONLY in "analog_intf_reg.h"
      01C088h 4       SW_SCLK             ;
      01C08Ch 4       SW_CNTL             ;/

MAC PCU Registers (mac_pcu.h) (hw2.0)

      028000h (00h) - REG_STA_ID0             ;aka MAC_PCU_STA_ADDR_L32
      028004h (01h) - REG_STA_ID1             ;aka MAC_PCU_STA_ADDR_U16
      028008h (02h) - REG_BSS_ID0             ;aka MAC_PCU_BSSID_L32
      02800Ch (03h) - REG_BSS_ID1             ;aka MAC_PCU_BSSID_U16
      028010h (04h) - MAC_PCU_REG_BCNRSSI     ;aka MAC_PCU_BCN_RSSI_AVE
      028014h (05h) - REG_TIME_OUT            ;aka MAC_PCU_ACK_CTS_TIMEOUT
      028018h (06h) - MAC_PCU_REG_BCNSIG      ;aka MAC_PCU_BCN_RSSI_CTL
      02801Ch (07h) - REG_USEC                ;aka MAC_PCU_USEC_LATENCY
      028020h (08h) - REG_BEACON
      028024h (09h) - REG_CFP_PERIOD          ;aka (MAC_???)PCU_MAX_CFP_DUR (?)
      028028h (0Ah) - REG_TIMER0
      02802Ch (0Bh) - REG_TIMER1
      028030h (0Ch) - REG_TIMER2
      028034h (0Dh) - REG_TIMER3
      028038h (0Eh) - REG_CFP_DUR             ;aka (MAC_???)PCU_MAX_CFP_DUR (?)
      02803Ch (0Fh) - REG_RX_FILTER           ;aka MAC_PCU_RX_FILTER
      028040h (10h) - REG_MCAST_FIL0          ;aka MAC_PCU_MCAST_FILTER_L32
      028044h (11h) - REG_MCAST_FIL1          ;aka MAC_PCU_MCAST_FILTER_U32
      028048h (12h) - MAC_PCU_REG_DIAGSW      ;aka MAC_PCU_DIAG_SW
      02804Ch (13h) - REG_TSF_L32
      028050h (14h) - REG_TSF_U32
      028054h (15h) - REG_TST_ADDAC           ;aka MAC_PCU_TST_ADDAC
      028058h (16h) - REG_DEF_ANT             ;aka MAC_PCU_DEF_ANTENNA
      02805Ch (17h) - MAC_PCU_REG_MUTE_MASKS0 ;aka MAC_PCU_AES_MUTE_MASK_0
      028060h (18h) - MAC_PCU_REG_MUTE_MASKS1 ;aka MAC_PCU_AES_MUTE_MASK_1
      028064h (19h) - MAC_PCU_REG_GATED_CLKS  ;aka MAC_PCU_GATED_CLKS
      028068h (1Ah) - MAC_PCU_REG_OBS2        ;aka MAC_PCU_OBS_BUS_2
      02806Ch (1Bh) - MAC_PCU_REG_OBS1        ;aka MAC_PCU_OBS_BUS_1
      028070h (1Ch..1Fh) - N/A
      028080h (20h) - REG_LAST_TSTP           ;aka MAC_PCU_LAST_BEACON_TSF (?)
      028084h (21h) - REG_NAV                 ;aka MAC_PCU_NAV
      028088h (22h) - REG_RTS_OK              ;aka MAC_PCU_RTS_SUCCESS_CNT
      02808Ch (23h) - REG_RTS_FAIL            ;aka MAC_PCU_RTS_FAIL_CNT
      028090h (24h) - REG_ACK_FAIL            ;aka MAC_PCU_ACK_FAIL_CNT
      028094h (25h) - REG_FCS_FAIL            ;aka MAC_PCU_FCS_FAIL_CNT
      028098h (26h) - REG_BEACON_CNT          ;aka MAC_PCU_BEACON_CNT
      02809Ch (27h..2Fh) - N/A
      0280C0h (30h) - MAC_PCU_REG_XRMODE      ;aka MAC_PCU_XRMODE
      0280C4h (31h) - MAC_PCU_REG_XRDEL       ;aka MAC_PCU_XRDEL
      0280C8h (32h) - MAC_PCU_REG_XRTO        ;aka MAC_PCU_XRTO
      0280CCh (33h) - MAC_PCU_REG_XRCRP       ;aka MAC_PCU_XRCRP
      0280D0h (34h) - MAC_PCU_REG_XRSTMP      ;aka MAC_PCU_XRSTMP
      0280D4h (35h) - MAC_PCU_REG_SLP1        ;aka MAC_PCU_SLP1 ;\moved to
      0280D8h (36h) - MAC_PCU_REG_SLP2        ;aka MAC_PCU_SLP2 ; 004xxxh/005xxxh
      0280DCh (37h) - (//MAC_PCU_REG_SLP3)    ;aka MAC_PCU_SLP3 ;/in hw4/hw6 (!)
      0280E0h (38h) - MAC_PCU_REG_BSSMSKL     ;aka MAC_PCU_ADDR1_MASK_L32
      0280E4h (39h) - MAC_PCU_REG_BSSMSKH     ;aka MAC_PCU_ADDR1_MASK_U16
      0280E8h (3Ah) - MAC_PCU_REG_TPC         ;aka MAC_PCU_TPC
      0280ECh (3Bh) - MAC_PCU_REG_TFC         ;aka MAC_PCU_TX_FRAME_CNT
      0280F0h (3Ch) - MAC_PCU_REG_RFC         ;aka MAC_PCU_RX_FRAME_CNT
      0280F4h (3Dh) - MAC_PCU_REG_RCC         ;aka MAC_PCU_RX_CLEAR_CNT
      0280F8h (3Eh) - MAC_PCU_REG_CC          ;aka MAC_PCU_CYCLE_CNT
      0280FCh (3Fh) - MAC_PCU_REG_QT1         ;aka MAC_PCU_QUIET_TIME_1
      028100h (40h) - MAC_PCU_REG_QT2         ;aka MAC_PCU_QUIET_TIME_2
      028104h (41h) - MAC_PCU_REG_TSF
      028108h (42h) - MAC_PCU_REG_NOACK       ;aka MAC_PCU_QOS_NO_ACK
      02810Ch (43h) - MAC_PCU_REG_PHYERR      ;aka MAC_PCU_PHY_ERROR_MASK
      028110h (44h) - MAC_PCU_REG_XRLAT       ;aka MAC_PCU_XRLAT
      028114h (45h) - MAC_PCU_REG_ACKSIFS_RESERVED
      028118h (46h) - MAC_PCU_REG_MICQOSCTL   ;aka MAC_PCU_MIC_QOS_CONTROL
      02811Ch (47h) - MAC_PCU_REG_MICQOSSEL   ;aka MAC_PCU_MIC_QOS_SELECT
      028120h (48h) - MAC_PCU_REG_MISCMODE    ;aka MAC_PCU_MISC_MODE
      028124h (49h) - MAC_PCU_REG_FILTOFDM    ;aka MAC_PCU_FILTER_OFDM_CNT
      028128h (4Ah) - MAC_PCU_REG_FILTCCK     ;aka MAC_PCU_FILTER_CCK_CNT
      02812Ch (4Bh) - MAC_PCU_REG_PHYCNT1     ;aka MAC_PCU_PHY_ERR_CNT_1
      028130h (4Ch) - MAC_PCU_REG_PHYCNTMASK1 ;aka MAC_PCU_PHY_ERR_CNT_1_MASK
      028134h (4Dh) - MAC_PCU_REG_PHYCNT2     ;aka MAC_PCU_PHY_ERR_CNT_2
      028138h (4Eh) - MAC_PCU_REG_PHYCNTMASK2 ;aka MAC_PCU_PHY_ERR_CNT_2_MASK
      02813Ch (4Fh) - MAC_PCU_REG_TSFTHRESH   ;aka MAC_PCU_TSF_THRESHOLD
      028140h (50h) - outcommented:MAC_PCU_REG_TSFCAL ;Misc
      028144h (51h) - MAC_PCU_REG_PHYERR_EIFS ;aka MAC_PCU_PHY_ERROR_EIFS_MASK
      028148h (52h) - outcommented:MAC_PCU_REG_SYNC1 ;Time
      02814Ch (53h) - outcommented:MAC_PCU_REG_SYNC2 ;Misc
      028150h (54h) - outcommented:MAC_PCU_REG_SYNC3 ;MCAST Addr_L
      028154h (55h) - outcommented:MAC_PCU_REG_SYNC4 ;MCAST Addr_U
      028158h (56h) - outcommented:MAC_PCU_REG_SYNC5 ;RX Time
      02815Ch (57h) - outcommented:MAC_PCU_REG_SYNC6 ;INC
      028160h (58h) - outcommented:MAC_PCU_REG_SYNC7 ;Last Time
      028164h (59h) - outcommented:MAC_PCU_REG_SYNC8 ;Updated Time
      028168h (5Ah) - MAC_PCU_REG_PHYCNT3     ;aka MAC_PCU_PHY_ERR_CNT_3
      02816Ch (5Bh) - MAC_PCU_REG_PHYCNTMASK3 ;aka MAC_PCU_PHY_ERR_CNT_3_MASK
      028170h (5Ch) - MAC_PCU_REG_BTMODE      ;aka MAC_PCU_BLUETOOTH_MODE
      028174h (5Dh) - MAC_PCU_REG_BTWEIGHT    ;aka MAC_PCU_BLUETOOTH_WEIGHTS
      028178h (5Eh) - MAC_PCU_REG_HCF         ;aka MAC_PCU_HCF_TIMEOUT
      02817Ch (5Fh) - MAC_PCU_REG_BTMODE2     ;aka MAC_PCU_BLUETOOTH_MODE2
      028180h (60h..67h) - MAC_PCU_REG_BFCOEF1[0..7]
      0281A0h (68h..6Fh) - N/A
      0281C0h (70h) - MAC_PCU_REG_BFCOEF2
      0281C4h (71h) - MAC_PCU_REG_KCMASK
      0281C8h (72h..73h) - N/A
      0281D0h (74h) - MAC_PCU_REG_TXSIFS      ;aka MAC_PCU_TXSIFS
      0281D4h (75h..7Ah) - N/A
      0281ECh (7Bh) - MAC_PCU_REG_TXOP_X      ;aka MAC_PCU_TXOP_X
      0281F0h (7Ch) - MAC_PCU_REG_TXOP_0_3    ;aka MAC_PCU_TXOP_0_3
      0281F4h (7Dh) - MAC_PCU_REG_TXOP_4_7    ;aka MAC_PCU_TXOP_4_7
      0281F8h (7Eh) - MAC_PCU_REG_TXOP_8_11   ;aka MAC_PCU_TXOP_8_11
      0281FCh (7Fh) - MAC_PCU_REG_TXOP_12_15  ;aka MAC_PCU_TXOP_12_15
      028200h (80h..87h) - MAC_PCU_REG_GNRCTMR_N[0..7]  ;aka GENERIC_TIMERSxxx?
      028220h (88h..8Fh) - MAC_PCU_REG_GNRCTMR_P[0..7]  ;aka GENERIC_TIMERSxxx?
      028240h (90h) - MAC_PCU_REG_GNRCTMR_M   ;aka MAC_PCU_GENERIC_TIMERS_MODE
      028244h (91h) - MAC_PCU_REG_SLP32_MODE
      028248h (92h) - MAC_PCU_REG_SLP32_WAKE
      02824Ch (93h) - MAC_PCU_REG_SLP32_TSF_INC
      028250h (94h) - MAC_PCU_REG_SLPMIB1
      028254h (95h) - MAC_PCU_REG_SLPMIB2
      028258h (96h) - MAC_PCU_REG_SLPMIB3
      02825Ch (97h) - MAC_PCU_REG_MISCMODE2   ;aka MAC_PCU_MISC_MODE2
      028260h (98h) - MAC_PCU_REG_SLP4
      028264h (99h) - MAC_PCU_REG_SLP5
      028268h (9Ah) - MAC_PCU_REG_MCICTL   ;\
      02826Ch (9Bh) - MAC_PCU_REG_MCIISR   ;
      028270h (9Ch) - MAC_PCU_REG_MCIIER   ;
      028274h (9Dh) - MAC_PCU_REG_MCIWLP   ;
      028278h (9Eh) - MAC_PCU_REG_MCIARW   ;
      02827Ch (9Fh) - MAC_PCU_REG_MCIARR   ; whatever MCI stuff
      028280h (A0h) - MAC_PCU_REG_MCIADW   ;
      028284h (A1h) - MAC_PCU_REG_MCIADR   ;
      028288h (A2h) - MAC_PCU_REG_MCIFRW   ;
      02828Ch (A3h) - MAC_PCU_REG_MCIFRR   ;
      028290h (A4h) - MAC_PCU_REG_MCIQRW   ;
      028294h (A5h) - MAC_PCU_REG_MCIQRR   ;
      028298h (A6h) - MAC_PCU_REG_MCIGRW   ;
      02829Ch (A7h) - MAC_PCU_REG_MCIGRR   ;
      0282A0h (A8h) - MAC_PCU_REG_MCISTAT  ;/
      0282A4h (A9h) - MAC_PCU_REG_BASIC_RATE_SET0 ;aka MAC_PCU_BASIC_RATE_SET0
      0282A8h (AAh) - MAC_PCU_REG_BASIC_RATE_SET1 ;aka MAC_PCU_BASIC_RATE_SET1
      0282ACh (ABh) - MAC_PCU_REG_BASIC_RATE_SET2 ;aka MAC_PCU_BASIC_RATE_SET2
      0282B0h (ACh) - MAC_PCU_REG_SEC_BSSID_L32   ;aka MAC_PCU_BSSID2_L32
      0282B4h (ADh) - MAC_PCU_REG_SEC_BSSID_U16   ;aka MAC_PCU_BSSID2_U16
      0282B8h (AEh..13Fh) - N/A
      028500h (140h..17Fh) - MAC_PCU_REG_FTYPE[0..3Fh]
      028600h (180h..19Fh) - N/A
      028680h (1A0h..1BFh) - MAC_PCU_REG_ACKSIFSMEM_RESERVED[0..1Fh]
      028700h (1C0h..1DFh) - MAC_PCU_REG_DUR[0..1Fh]
      028780h (1E0h..1EFh) - N/A
      0287C0h (1F0h..1F7h) - MAC_PCU_REG_RTD[0..7]
      0287E0h (1F8h..1FFh) - MAC_PCU_REG_DTR[0..7]
      028800h (200h..5FFh) - MAC_PCU_REG_KC[0..3FFh]  ;aka KC = KEY_CACHE ?

Undocumented hw2 registers

      029800h ?       Used in hw2, but undocumented... maybe BASEBAND_0 alike hw4?
      02A000h ?       Used in hw2, but undocumented... maybe BASEBAND_1 alike hw4?
      030000h ?       Used in hw2, but undocumented... maybe mode switch?

Note: 030000h seems to be used only in AR6013/AR6014 (not AR6002), maybe RDMA or EFUSE alike hw4, or maybe for atheros/mitsumi mode switch.

DSi Atheros Wifi - Internal I/O Map Summary (hw4)

Overall Summary (hw4.0)

      004000h 2E8h    (rtc_wlan_reg.h)
      008000h 630h    Memory Controller (BCAM) (vmc_wlan_reg.h)
      00C000h 14h     (uart_reg.h)
      00D000h ..      DBG_UART_BASE_ADDRESS  ;another UART, as above, for debug?
      00E000h 38h     (umbox_wlan_reg.h)
      010000h 18h     (si_reg.h)
      014000h BCh     (gpio_athr_wlan_reg.h)
      018000h 12Ch    (mbox_wlan_reg.h)
      01A000h 20000h  WLAN_HOST_IF_WINDOW (mbox_wlan_reg.h)
      01C000h 748h    (analog_intf_athr_wlan_reg.h)
      020000h DCh     WMAC DMA and IRQ   (mac_dma_reg.h)
      020800h 244h    WMAC QCU Queue     (mac_dma_reg.h)
      021000h 274h    WMAC DCU           (mac_dma_reg.h)
      028000h C00h    MAC_PCU            (mac_pcu_reg.h)
      029800h 800h    MAC_PCU_BASEBAND_0 (bb_lc_reg.h)
      02A000h 1210h   MAC_PCU_BASEBAND_1 (bb_lc_reg.h)
      02C000h 1000h   MAC_PCU_BASEBAND_2 (mac_pcu_reg.h)
      02D000h 1000h   MAC_PCU_BASEBAND_3 (mac_pcu_reg.h)
      02E000h 800h    MAC_PCU_BUF        (mac_pcu_reg.h)
      030100h 68h     (rdma_reg.h)
      031000h 1000h   (efuse_reg.h)

rtc_wlan_reg.h (hw4.0)

      004000h 4       WLAN_RESET_CONTROL
      004004h 4       WLAN_XTAL_CONTROL
      004008h 4       WLAN_TCXO_DETECT
      00400Ch 4       WLAN_XTAL_TEST
      004010h 4       WLAN_QUADRATURE
      004014h 4       WLAN_PLL_CONTROL
      004018h 4       WLAN_PLL_SETTLE
      00401Ch 4       WLAN_XTAL_SETTLE
      004020h 4       WLAN_CPU_CLOCK
      004024h 4       WLAN_CLOCK_OUT
      004028h 4       WLAN_CLOCK_CONTROL
      00402Ch 4       WLAN_BIAS_OVERRIDE
      004030h 4       WLAN_WDT_CONTROL            ;\
      004034h 4       WLAN_WDT_STATUS             ;
      004038h 4       WLAN_WDT                    ; Watchdog Timer
      00403Ch 4       WLAN_WDT_COUNT              ;
      004040h 4       WLAN_WDT_RESET              ;/
      004044h 4       WLAN_INT_STATUS             ;-Interrupt Status
      004048h 4       WLAN_LF_TIMER0              ;\
      00404Ch 4       WLAN_LF_TIMER_COUNT0        ; Low-Freq Timer 0
      004050h 4       WLAN_LF_TIMER_CONTROL0      ;
      004054h 4       WLAN_LF_TIMER_STATUS0       ;/
      004058h 4       WLAN_LF_TIMER1              ;\
      00405Ch 4       WLAN_LF_TIMER_COUNT1        ; Low-Freq Timer 1
      004060h 4       WLAN_LF_TIMER_CONTROL1      ;
      004064h 4       WLAN_LF_TIMER_STATUS1       ;/
      004068h 4       WLAN_LF_TIMER2              ;\
      00406Ch 4       WLAN_LF_TIMER_COUNT2        ; Low-Freq Timer 2
      004070h 4       WLAN_LF_TIMER_CONTROL2      ;
      004074h 4       WLAN_LF_TIMER_STATUS2       ;/
      004078h 4       WLAN_LF_TIMER3              ;\
      00407Ch 4       WLAN_LF_TIMER_COUNT3        ; Low-Freq Timer 3
      004080h 4       WLAN_LF_TIMER_CONTROL3      ;
      004084h 4       WLAN_LF_TIMER_STATUS3       ;/
      004088h 4       WLAN_HF_TIMER               ;\
      00408Ch 4       WLAN_HF_TIMER_COUNT         ; High-Freq Timer
      004090h 4       WLAN_HF_LF_COUNT      ;<--  ;
      004094h 4       WLAN_HF_TIMER_CONTROL       ;
      004098h 4       WLAN_HF_TIMER_STATUS        ;/
      00409Ch 4       WLAN_RTC_CONTROL            ;\
      0040A0h 4       WLAN_RTC_TIME               ;
      0040A4h 4       WLAN_RTC_DATE               ;
      0040A8h 4       WLAN_RTC_SET_TIME           ; Real-Time Clock
      0040ACh 4       WLAN_RTC_SET_DATE           ;
      0040B0h 4       WLAN_RTC_SET_ALARM          ;
      0040B4h 4       WLAN_RTC_CONFIG             ;
      0040B8h 4       WLAN_RTC_ALARM_STATUS       ;/
      0040BCh 4       WLAN_UART_WAKEUP
      0040C0h 4       WLAN_RESET_CAUSE
      0040C4h 4       WLAN_SYSTEM_SLEEP
      0040C8h 4       WLAN_SDIO_WRAPPER
      0040CCh 4       WLAN_MAC_SLEEP_CONTROL
      0040D0h 4       WLAN_KEEP_AWAKE
      0040D4h 4       WLAN_LPO_CAL_TIME                   ;\
      0040D8h 4       WLAN_LPO_INIT_DIVIDEND_INT          ;
      0040DCh 4       WLAN_LPO_INIT_DIVIDEND_FRACTION     ; LPO
      0040E0h 4       WLAN_LPO_CAL                        ;
      0040E4h 4       WLAN_LPO_CAL_TEST_CONTROL           ;
      0040E8h 4       WLAN_LPO_CAL_TEST_STATUS            ;/
      0040ECh 4       WLAN_CHIP_ID                        ;-Chip ID
      0040F0h 4       WLAN_DERIVED_RTC_CLK
      0040F4h 4       MAC_PCU_SLP32_MODE          ;\
      0040F8h 4       MAC_PCU_SLP32_WAKE          ;
      0040FCh 4       MAC_PCU_SLP32_INC           ;
      004100h 4       MAC_PCU_SLP_MIB1            ;
      004104h 4       MAC_PCU_SLP_MIB2            ;
      004108h 4       MAC_PCU_SLP_MIB3            ;/
      00410Ch 4       WLAN_POWER_REG              ;\located here in hw4.0
      004110h 4       WLAN_CORE_CLK_CTRL          ; (other address as in hw2.0)
      004114h 4       WLAN_GPIO_WAKEUP_CONTROL    ;/
      (below 4118h..42E8h is new in hw4.0, didn't exist in hw2.0)
      004118h 4       (WLAN_)HT
      00411Ch 4       MAC_PCU_TSF_L32
      004120h 4       MAC_PCU_TSF_U32
      004124h 4       MAC_PCU_WBTIMER
      004128h 1x24    PAD0
      004140h 4x16    MAC_PCU_GENERIC_TIMERS[0..15]
      004180h 4       MAC_PCU_GENERIC_TIMERS_MODE
      004184h 1x60    PAD1
      0041C0h 4x16    MAC_PCU_GENERIC_TIMERS2[0..15]
      004200h 4       MAC_PCU_GENERIC_TIMERS_MODE2
      004204h 4       MAC_PCU_SLP1
      004208h 4       MAC_PCU_SLP2
      00420Ch 4       MAC_PCU_RESET_TSF
      004210h 4       MAC_PCU_TSF_ADD_PLL
      004214h 4       SLEEP_RETENTION
      004218h 4       BTCOEXCTRL                          ;\
      00421Ch 4       WBSYNC_PRIORITY1                    ;
      004220h 4       WBSYNC_PRIORITY2                    ;
      004224h 4       WBSYNC_PRIORITY3                    ;
      004228h 4       BTCOEX0  ;SYNC_DUR                  ;
      00422Ch 4       BTCOEX1  ;CLK_THRES                 ;
      004230h 4       BTCOEX2  ;FRAME_THRES               ; Bluetooth
      004234h 4       BTCOEX3  ;CLK_CNT                   ; Coexistance
      004238h 4       BTCOEX4  ;FRAME_CNT                 ;
      00423Ch 4       BTCOEX5  ;IDLE_CNT                  ;
      004240h 4       BTCOEX6  ;IDLE_RESET_LVL_BITMAP     ;
      004244h 4       LOCK                                ;
      004248h 4       NOLOCK_PRIORITY                     ;
      00424Ch 4       WBSYNC                              ;
      004250h 4       WBSYNC1                             ;
      004254h 4       WBSYNC2                             ;
      004258h 4       WBSYNC3                             ;
      00425Ch 4       WB_TIMER_TARGET                     ;
      004260h 4       WB_TIMER_SLOP                       ;
      004264h 4       BTCOEX_INT_EN                       ;
      004268h 4       BTCOEX_INT_STAT                     ;
      00426Ch 4       BTPRIORITY_INT_EN                   ;
      004270h 4       BTPRIORITY_INT_STAT                 ;
      004274h 4       BTPRIORITY_STOMP_INT_EN             ;
      004278h 4       BTPRIORITY_STOMP_INT_STAT           ;/
      00427Ch 4       MAC_PCU_BMISS_TIMEOUT
      004280h 4       MAC_PCU_CAB_AWAKE
      004284h 4       LP_PERF_COUNTER
      004288h 4       LP_PERF_LIGHT_SLEEP
      00428Ch 4       LP_PERF_DEEP_SLEEP
      004290h 4       LP_PERF_ON
      004294h 4       ST_64_BIT                           ;\
      004298h 4       MESSAGE_WR                          ; also Bluetooth Coex
      00429Ch 4       MESSAGE_WR_P                        ; related? (sorted as
      0042A0h 4       MESSAGE_RD                          ; so in hw6 files)
      0042A4h 4       MESSAGE_RD_P                        ;/
      0042A8h 4       CHIP_MODE
      0042ACh 4       CLK_REQ_FALL_EDGE
      0042B0h 4       OTP
      0042B4h 4       OTP_STATUS
      0042B8h 4       PMU
      0042BCh 1x4     PAD2
      0042C0h 4x2     PMU_CONFIG[0..1]
      0042C8h 4       PMU_BYPASS
      0042CCh 4       MAC_PCU_TSF2_L32
      0042D0h 4       MAC_PCU_TSF2_U32
      0042D4h 4       MAC_PCU_GENERIC_TIMERS_MODE3
      0042D8h 4       MAC_PCU_DIRECT_CONNECT
      0042DCh 4       THERM_CTRL1
      0042E0h 4       THERM_CTRL2
      0042E4h 4       THERM_CTRL3
      0042E8h -       unused/unspecified

vmc_wlan_reg.h (hw4.0)

      008000h 4x128   WLAN_MC_BCAM_VALID[0..127]          ;\
      008200h 4x128   WLAN_MC_BCAM_COMPARE[0..127]        ; ROM Patches
      008400h 4x128   WLAN_MC_BCAM_TARGET[0..127]         ;/
      008600h 4       WLAN_APB_ADDR_ERROR_CONTROL         ;\
      008604h 4       WLAN_APB_ADDR_ERROR_STATUS          ; ADDR_ERROR
      008608h 4       WLAN_AHB_ADDR_ERROR_CONTROL         ;
      00860Ch 4       WLAN_AHB_ADDR_ERROR_STATUS          ;/
      008610h 4       WLAN_BCAM_CONFLICT_ERROR
      008614h 4       WLAN_CPU_PERF_CNT
      008618h 4       WLAN_CPU_INST_FETCH
      00861Ch 4       WLAN_CPU_DATA_FETCH
      008620h 4       WLAN_CPU_RAM1_CONFLICT
      008624h 4       WLAN_CPU_RAM2_CONFLICT
      008628h 4       WLAN_CPU_RAM3_CONFLICT
      00862Ch 4       WLAN_CPU_RAM4_CONFLICT
      008630h -       unused/unspecified

uart_reg.h (hw4.0)

      00C000h 4       UART_DATA
      00C004h 4       UART_CONTROL
      00C008h 4       UART_CLKDIV
      00C00Ch 4       UART_INT
      00C010h 4       UART_INT_EN
      00C014h -       unused/unspecified
      00D000h ..      DBG_UART_BASE_ADDRESS  ;another UART, as above, for debug?
      00Dxxxh -       unused/unspecified

umbox_wlan_reg.h (hw4.0)

      00E000h 4x2     UMBOX_FIFO[0..1]
      00E008h 4       UMBOX_FIFO_STATUS
      00E00Ch 4       UMBOX_DMA_POLICY
      00E010h 4       UMBOX0_DMA_RX_DESCRIPTOR_BASE
      00E014h 4       UMBOX0_DMA_RX_CONTROL
      00E018h 4       UMBOX0_DMA_TX_DESCRIPTOR_BASE
      00E01Ch 4       UMBOX0_DMA_TX_CONTROL
      00E020h 4       UMBOX_FIFO_TIMEOUT
      00E024h 4       UMBOX_INT_STATUS
      00E028h 4       UMBOX_INT_ENABLE
      00E02Ch 4       UMBOX_DEBUG
      00E030h 4       UMBOX_FIFO_RESET
      00E034h 4       UMBOX_HCI_FRAMER
      00E038h -       unused/unspecified

si_reg.h (hw4.0)

      010000h 4       SI_CONFIG
      010004h 4       SI_CS
      010008h 4       SI_TX_DATA0
      01000Ch 4       SI_TX_DATA1
      010010h 4       SI_RX_DATA0
      010014h 4       SI_RX_DATA1
      010018h -       unused/unspecified

gpio_athr_wlan_reg.h (hw4.0)

      014000h 4       WLAN_GPIO_OUT            ;\GPIO Output Data
      014004h 4       WLAN_GPIO_OUT_W1TS       ; (direct, and Write-1-To-Set/Clr)
      014008h 4       WLAN_GPIO_OUT_W1TC       ;/
      01400Ch 4       WLAN_GPIO_ENABLE         ;\GPIO Output Enable
      014010h 4       WLAN_GPIO_ENABLE_W1TS    ; (direct, and Write-1-To-Set/Clr)
      014014h 4       WLAN_GPIO_ENABLE_W1TC    ;/
      014018h 4       WLAN_GPIO_IN             ;-GPIO Input
      01401Ch 4       WLAN_GPIO_STATUS         ;\GPIO Interrupt Status
      014020h 4       WLAN_GPIO_STATUS_W1TS    ; (direct, and Write-1-To-Set/Clr)
      014024h 4       WLAN_GPIO_STATUS_W1TC    ;/
      014028h 4       WLAN_GPIO_PIN0     ;GPIO0  Bluetooth coex BT_FREQUENCY
      01402Ch 4       WLAN_GPIO_PIN1     ;GPIO1  Bluetooth coex WLAN_ACTIVE
      014030h 4       WLAN_GPIO_PIN2     ;GPIO2  Bluetooth coex BT_ACTIVE
      014034h 4       WLAN_GPIO_PIN3     ;GPIO3  Bluetooth coex BT_PRIORITY
      014038h 4       WLAN_GPIO_PIN4     ;GPIO4  -
      01403Ch 4       WLAN_GPIO_PIN5     ;GPIO5  JTAG TMS input
      014040h 4       WLAN_GPIO_PIN6     ;GPIO6  JTAG TCK input
      014044h 4       WLAN_GPIO_PIN7     ;GPIO7  JTAG TDI input
      014048h 4       WLAN_GPIO_PIN8     ;GPIO8  JTAG TDO output
      01404Ch 4       WLAN_GPIO_PIN9     ;GPIO9  SDIO CMD
      014050h 4       WLAN_GPIO_PIN10    ;GPIO10 SDIO D3
      014054h 4       WLAN_GPIO_PIN11    ;GPIO11 SDIO D2
      014058h 4       WLAN_GPIO_PIN12    ;GPIO12 SDIO D1
      01405Ch 4       WLAN_GPIO_PIN13    ;GPIO13 SDIO D0
      014060h 4       WLAN_GPIO_PIN14    ;GPIO14 SDIO CLK
      014064h 4       WLAN_GPIO_PIN15    ;GPIO15 HCI UART TXD
      014068h 4       WLAN_GPIO_PIN16    ;GPIO16 HCI UART RTS
      01406Ch 4       WLAN_GPIO_PIN17    ;GPIO17 HCI UART RXD
      014070h 4       WLAN_GPIO_PIN18    ;GPIO18 HCI UART CTS
      014074h 4       WLAN_GPIO_PIN19    ;GPIO19 SDIO/GSPI interface select
      014078h 4       WLAN_GPIO_PIN20    ;GPIO20 SDIO/GSPI interface select
      01407Ch 4       WLAN_GPIO_PIN21    ;GPIO21 external input sleep clock
      014080h 4       WLAN_GPIO_PIN22    ;GPIO22 wake on wireless input (WOW)
      014084h 4       WLAN_GPIO_PIN23    ;GPIO23 reference clk output to BT chip
      014088h 4       WLAN_GPIO_PIN24    ;GPIO24 request clk from BT chip
      01408Ch 4       WLAN_GPIO_PIN25    ;GPIO25 request reference clk (CLK_REQ)
      014090h 4       SDIO
      014094h 4       FUNC_BUS
      014098h 4       WL_SOC_APB
      01409Ch 4       WLAN_SIGMA_DELTA
      0140A0h 4       WL_BOOTSTRAP
      0140A4h 4       CLOCK_GPIO
      0140A8h 4       WLAN_DEBUG_CONTROL
      0140ACh 4       WLAN_DEBUG_INPUT_SEL
      0140B0h 4       WLAN_DEBUG_OUT
      0140B4h 4       WLAN_RESET_TUPLE_STATUS
      0140B8h 4       ANTENNA_SLEEP_CONTROL
      0140BCh -       unused/unspecified

MBOX Registers (mbox_wlan_reg.h) (hw4.0)

      018000h 4x4     WLAN_MBOX_FIFO[0..3]
      018010h 4       WLAN_MBOX_FIFO_STATUS
      018014h 4       WLAN_MBOX_DMA_POLICY
      018018h 4       WLAN_MBOX0_DMA_RX_DESCRIPTOR_BASE   ;\
      01801Ch 4       WLAN_MBOX0_DMA_RX_CONTROL           ; MBOX 0
      018020h 4       WLAN_MBOX0_DMA_TX_DESCRIPTOR_BASE   ;
      018024h 4       WLAN_MBOX0_DMA_TX_CONTROL           ;/
      018028h 4       WLAN_MBOX1_DMA_RX_DESCRIPTOR_BASE   ;\
      01802Ch 4       WLAN_MBOX1_DMA_RX_CONTROL           ; MBOX 1
      018030h 4       WLAN_MBOX1_DMA_TX_DESCRIPTOR_BASE   ;
      018034h 4       WLAN_MBOX1_DMA_TX_CONTROL           ;/
      018038h 4       WLAN_MBOX2_DMA_RX_DESCRIPTOR_BASE   ;\
      01803Ch 4       WLAN_MBOX2_DMA_RX_CONTROL           ; MBOX 2
      018040h 4       WLAN_MBOX2_DMA_TX_DESCRIPTOR_BASE   ;
      018044h 4       WLAN_MBOX2_DMA_TX_CONTROL           ;/
      018048h 4       WLAN_MBOX3_DMA_RX_DESCRIPTOR_BASE   ;\
      01804Ch 4       WLAN_MBOX3_DMA_RX_CONTROL           ; MBOX 3
      018050h 4       WLAN_MBOX3_DMA_TX_DESCRIPTOR_BASE   ;
      018054h 4       WLAN_MBOX3_DMA_TX_CONTROL           ;/
      018058h 4       WLAN_MBOX_INT_STATUS                ;\Interrupt
      01805Ch 4       WLAN_MBOX_INT_ENABLE                ;/
      018060h 4       WLAN_INT_HOST            ;IRQ to sdio/host
      018064h 1x28    PAD0
      018080h 4x8     WLAN_LOCAL_COUNT[0..7]        ;SDIO func1 ?
      0180A0h 4x8     WLAN_COUNT_INC[0..7]          ;SDIO func1 ?
      0180C0h 4x8     WLAN_LOCAL_SCRATCH[0..7]      ;SDIO func1 ?
      0180E0h 4       WLAN_USE_LOCAL_BUS
      0180E4h 4       WLAN_SDIO_CONFIG              ;SDIO func0 ?
      0180E8h 4       WLAN_MBOX_DEBUG
      0180ECh 4       WLAN_MBOX_FIFO_RESET
      0180F0h 4x4     WLAN_MBOX_TXFIFO_POP[0..3]
      018100h 4x4     WLAN_MBOX_RXFIFO_POP[0..3]
      018110h 4       WLAN_SDIO_DEBUG
      018114h 4       WLAN_GMBOX0_DMA_RX_DESCRIPTOR_BASE  ;\
      018118h 4       WLAN_GMBOX0_DMA_RX_CONTROL          ;
      01811Ch 4       WLAN_GMBOX0_DMA_TX_DESCRIPTOR_BASE  ; new (unlike hw2.0)
      018120h 4       WLAN_GMBOX0_DMA_TX_CONTROL          ;
      018124h 4       WLAN_GMBOX_INT_STATUS               ;
      018128h 4       WLAN_GMBOX_INT_ENABLE               ;/
      01812Ch 1x7892  PAD1
      01A000h 4x2048  WLAN_HOST_IF_WINDOW[0..2047]

analog_intf_athr_wlan_reg.h (hw4.0)

      01C000h 4       RXRF_BIAS1
      01C004h 4       RXRF_BIAS2
      01C008h 4       RXRF_GAINSTAGES
      01C00Ch 4       RXRF_AGC
      01C010h 1x48    PAD__0
      01C040h 4       TXRF1
      01C044h 4       TXRF2
      01C048h 4       TXRF3
      01C04Ch 4       TXRF4
      01C050h 4       TXRF5
      01C054h 4       TXRF6
      01C058h 4       TXRF7 ;PADRVGNTAB_0..4    ;\
      01C05Ch 4       TXRF8 ;PADRVGNTAB_5..9    ;
      01C060h 4       TXRF9 ;PADRVGNTAB_10..14  ;/
      01C064h 4       TXRF10
      01C068h 4       TXRF11
      01C06Ch 4       TXRF12
      01C070h 1x16    PAD__1
      01C080h 4       SYNTH1
      01C084h 4       SYNTH2
      01C088h 4       SYNTH3
      01C08Ch 4       SYNTH4
      01C090h 4       SYNTH5
      01C094h 4       SYNTH6
      01C098h 4       SYNTH7
      01C09Ch 4       SYNTH8
      01C0A0h 4       SYNTH9
      01C0A4h 4       SYNTH10
      01C0A8h 4       SYNTH11
      01C0ACh 4       SYNTH12
      01C0B0h 4       SYNTH13
      01C0B4h 4       SYNTH14
      01C0B8h 1x8     PAD__2
      01C0C0h 4       BIAS1
      01C0C4h 4       BIAS2
      01C0C8h 4       BIAS3
      01C0CCh 4       BIAS4
      01C0D0h 1x48    PAD__3
      01C100h 4       RXTX1
      01C104h 4       RXTX2
      01C108h 4       RXTX3
      01C10Ch 1x52    PAD__4
      01C140h 4       BB1
      01C144h 4       BB2
      01C148h 4       BB3
      01C14Ch 1x308   PAD__5
      01C280h 4       PLLCLKMODA
      01C284h 4       PLLCLKMODA2
      01C288h 4       TOP
      01C28Ch 4       THERM
      01C290h 4       XTAL
      01C294h 1x236   PAD__6
      01C380h 4       RBIST_CNTRL         ;with extra bit in newer revision
      01C384h 4       TX_DC_OFFSET
      01C388h 4       TX_TONEGEN0
      01C38Ch 4       TX_TONEGEN1
      01C390h 4       TX_LFTONEGEN0
      01C394h 4       TX_LINEAR_RAMP_I
      01C398h 4       TX_LINEAR_RAMP_Q
      01C39Ch 4       TX_PRBS_MAG
      01C3A0h 4       TX_PRBS_SEED_I
      01C3A4h 4       TX_PRBS_SEED_Q
      01C3A8h 4       CMAC_DC_CANCEL
      01C3ACh 4       CMAC_DC_OFFSET
      01C3B0h 4       CMAC_CORR
      01C3B4h 4       CMAC_POWER
      01C3B8h 4       CMAC_CROSS_CORR
      01C3BCh 4       CMAC_I2Q2
      01C3C0h 4       CMAC_POWER_HPF
      01C3C4h 4       RXDAC_SET1
      01C3C8h 4       RXDAC_SET2
      01C3CCh 4       RXDAC_LONG_SHIFT
      01C3D0h 4       CMAC_RESULTS_I
      01C3D4h 4       CMAC_RESULTS_Q
      01C3D8h 1x872   PAD__7
      01C740h 4       PMU1
      01C744h 4       PMU2
      01C748h -       unused/unspecified

mac_dma_reg.h (hw4.0)

      020000h 1x8     -
      020008h 4       MAC_DMA_CR      - MAC Control Register
      02000Ch 4       MAC_DMA_RXDP    - MAC receive queue descriptor pointer
      020010h 4       -
      020014h 4       MAC_DMA_CFG     - MAC configuration and status register
      020018h 4       -
      02001Ch 4       -
      020020h 4       MAC_DMA_MIRT    - Maximum rate threshold register
      020024h 4       MAC_DMA_IER     - MAC Interrupt enable register
      020028h 4       MAC_DMA_TIMT    - Transmit Interrupt Mitigation Threshold
      02002Ch 4       MAC_DMA_RIMT    - Receive Interrupt Mitigation Threshold
      020030h 4       MAC_DMA_TXCFG   - MAC tx DMA size config register
      020034h 4       MAC_DMA_RXCFG   - MAC rx DMA size config register
      020038h 4       -
      02003Ch 4       -
      020040h 4       MAC_DMA_MIBC    - MAC MIB control register
      020044h 4       MAC_DMA_TOPS    - MAC timeout prescale count
      020048h 4       MAC_DMA_RXNPTO  - MAC no frame received timeout
      02004Ch 4       MAC_DMA_TXNPTO  - MAC no frame trasmitted timeout
      020050h 4       MAC_DMA_RPGTO   - MAC receive frame gap timeout
      020054h 4       MAC_DMA_RPCNT   - MAC receive frame count limit
      020058h 4       MAC_DMA_MACMISC - MAC miscellaneous control/status register
      02005Ch ..      -
     MAC IRQ...
      020080h 4       MAC_DMA_ISR    - Primary Interrupt Status Register         ;\
      020084h 4       MAC_DMA_ISR_S0 - Secondary Interrupt 0 Status TX OK/DESC   ;
      020088h 4       MAC_DMA_ISR_S1 - Secondary Interrupt 1 Status TX ERR/EOL   ;
      02008Ch 4       MAC_DMA_ISR_S2 - Secondary Interrupt 2 Status TX URN/MISC  ;
      020090h 4       MAC_DMA_ISR_S3 - Secondary Interrupt 3 Status QCBR OVF/URN ;
      020094h 4       MAC_DMA_ISR_S4 - Secondary Interrupt 4 Status QTRIG        ;
      020098h 4       MAC_DMA_ISR_S5 - Secondary Interrupt 5 Status TIMERS       ;/
      02009Ch 4       -
      0200A0h 4       MAC_DMA_IMR    - Primary Interrupt Mask Register           ;\
      0200A4h 4       MAC_DMA_IMR_S0 - Secondary Interrupt 0 Mask TX OK/DESC     ;
      0200A8h 4       MAC_DMA_IMR_S1 - Secondary Interrupt 1 Mask TX ERR/EOL     ;
      0200ACh 4       MAC_DMA_IMR_S2 - Secondary Interrupt 2 Mask TX URN/MISC    ;
      0200B0h 4       MAC_DMA_IMR_S3 - Secondary Interrupt 3 Mask QCBR OVF/URN   ;
      0200B4h 4       MAC_DMA_IMR_S4 - Secondary Interrupt 4 Mask QTRIG          ;
      0200B8h 4       MAC_DMA_IMR_S5 - Secondary Interrupt 5 Mask TIMERS         ;/
      0200BCh 4       -
      0200C0h 4       MAC_DMA_ISR_RAC  - Primary Interrupt Read-and-Clear        ;\
      0200C4h 4       MAC_DMA_ISR_S0_S - Secondary 0 Read-and-Clear TX OK/DESC   ;
      0200C8h 4       MAC_DMA_ISR_S1_S - Secondary 1 Read-and-Clear TX ERR/EOL   ;
      0200CCh 4       MAC_DMA_ISR_S2_S - Secondary 2 Read-and-Clear TX URN/MISC  ;
      0200D0h 4       MAC_DMA_ISR_S3_S - Secondary 3 Read-and-Clear QCBR OVF/URN ;
      0200D4h 4       MAC_DMA_ISR_S4_S - Secondary 4 Read-and-Clear QTRIG        ;
      0200D8h 4       MAC_DMA_ISR_S5_S - Secondary 5 Read-and-Clear TIMERS       ;/
      0200DCh ..      -
     MAC QCU...
      020800h 4x10    MAC_DMA_Q(0..9)_TXDP         ;MAC Transmit Queue descr.ptr
      020828h ..      -
      020840h 4       MAC_DMA_Q_TXE                ;MAC Transmit Queue enable
      020844h ..      -
      020880h 4       MAC_DMA_Q_TXD                ;MAC Transmit Queue disable
      020884h ..      -
      0208C0h 4x10    MAC_DMA_Q(0..9)_CBRCFG       ;MAC CBR configuration
      0208E8h ..      -
      020900h 4x10    MAC_DMA_Q(0..9)_RDYTIMECFG   ;MAC ReadyTime configuration
      020928h ..      -
      020940h 4       MAC_DMA_Q_ONESHOTMAC_DMAM_SC ;MAC OneShotArm set control
      020944h ..      -
      020980h 4       MAC_DMA_Q_ONESHOTMAC_DMAM_CC ;MAC OneShotArm clear control
      020984h ..      -
      0209C0h 4x10    MAC_DMA_Q(0..9)_MISC         ;MAC Misc QCU settings
      0209E8h ..      -
      020A00h 4x10    MAC_DMA_Q(0..9)_STS          ;MAC Misc QCU status/counter
      020A28h ..      -
      020A40h 4       MAC_DMA_Q_RDYTIMESHDN        ;MAC ReadyTimeShutdown status
      020A44h ..      -
     MAC DCU...
      021000h 4x10    MAC_DMA_D(0..9)_QCUMASK - MAC QCU Mask (DCU-to-QCU or so?)
      021028h 8       -
      021030h 4       MAC_DMA_D_GBL_IFS_SIFS  - DCU global SIFS settings
      021034h 12      -
      021040h 4x10    MAC_DMA_D(0..9)_LCL_IFS - MAC DCU-specific IFS settings
      021068h 8       -
      021070h 4       MAC_DMA_D_GBL_IFS_SLOT   - DC global slot interval
      021074h 12      -
      021080h 4x10    MAC_DMA_D(0..9)_RETRY_LIMIT - MAC Retry limits
      0210A8h 8       -
      0210B0h 4       MAC_DMA_D_GBL_IFS_EIFS   - DCU global EIFS setting
      0210B4h 12      -
      0210C0h 4x10    MAC_DMA_D(0..9)_CHNTIME  - MAC ChannelTime settings
      0210E8h 8       -
      0210F0h 4       MAC_DMA_D_GBL_IFS_MISC   - DCU global misc. IFS settings
      0210F4h 12      -
      021100h 4x10    MAC_DMA_D(0..9)_MISC     - MAC Misc DCU-specific settings
      021128h ..      -
      021140h 4       MAC_DMA_D_SEQNUM         - MAC Frame sequence number
      021144h ..      -
      021180h 4x10    MAC_DMA_D(0..9)_EOL     -
      0211A8h ..      -
      021230h 4       MAC_DMA_D_FPCTL         - DCU frame prefetch settings
      021234h ..      -
      021270h 4       MAC_DMA_D_TXPSE         - DCU transmit pause control/status
      021274h ..      -

mac_pcu_reg.h (1) (hw4.0)

      028000h 4       MAC_PCU_STA_ADDR_L32
      028004h 4       MAC_PCU_STA_ADDR_U16
      028008h 4       MAC_PCU_BSSID_L32
      02800Ch 4       MAC_PCU_BSSID_U16
      028010h 4       MAC_PCU_BCN_RSSI_AVE
      028014h 4       MAC_PCU_ACK_CTS_TIMEOUT
      028018h 4       MAC_PCU_BCN_RSSI_CTL
      02801Ch 4       MAC_PCU_USEC_LATENCY
      028020h 4       PCU_MAX_CFP_DUR
      028024h 4       MAC_PCU_RX_FILTER
      028028h 4       MAC_PCU_MCAST_FILTER_L32
      02802Ch 4       MAC_PCU_MCAST_FILTER_U32
      028030h 4       MAC_PCU_DIAG_SW
      028034h 4       MAC_PCU_TST_ADDAC
      028038h 4       MAC_PCU_DEF_ANTENNA
      02803Ch 4       MAC_PCU_AES_MUTE_MASK_0
      028040h 4       MAC_PCU_AES_MUTE_MASK_1
      028044h 4       MAC_PCU_GATED_CLKS
      028048h 4       MAC_PCU_OBS_BUS_2
      02804Ch 4       MAC_PCU_OBS_BUS_1
      028050h 4       MAC_PCU_DYM_MIMO_PWR_SAVE
      028054h 4       MAC_PCU_LAST_BEACON_TSF
      028058h 4       MAC_PCU_NAV
      02805Ch 4       MAC_PCU_RTS_SUCCESS_CNT
      028060h 4       MAC_PCU_RTS_FAIL_CNT
      028064h 4       MAC_PCU_ACK_FAIL_CNT
      028068h 4       MAC_PCU_FCS_FAIL_CNT
      02806Ch 4       MAC_PCU_BEACON_CNT
      028070h 4       MAC_PCU_XRMODE
      028074h 4       MAC_PCU_XRDEL
      028078h 4       MAC_PCU_XRTO
      02807Ch 4       MAC_PCU_XRCRP
      028080h 4       MAC_PCU_XRSTMP
      028084h 4       MAC_PCU_ADDR1_MASK_L32
      028088h 4       MAC_PCU_ADDR1_MASK_U16
      02808Ch 4       MAC_PCU_TPC
      028090h 4       MAC_PCU_TX_FRAME_CNT
      028094h 4       MAC_PCU_RX_FRAME_CNT
      028098h 4       MAC_PCU_RX_CLEAR_CNT
      02809Ch 4       MAC_PCU_CYCLE_CNT
      0280A0h 4       MAC_PCU_QUIET_TIME_1
      0280A4h 4       MAC_PCU_QUIET_TIME_2
      0280A8h 4       MAC_PCU_QOS_NO_ACK
      0280ACh 4       MAC_PCU_PHY_ERROR_MASK
      0280B0h 4       MAC_PCU_XRLAT
      0280B4h 4       MAC_PCU_RXBUF
      0280B8h 4       MAC_PCU_MIC_QOS_CONTROL
      0280BCh 4       MAC_PCU_MIC_QOS_SELECT
      0280C0h 4       MAC_PCU_MISC_MODE
      0280C4h 4       MAC_PCU_FILTER_OFDM_CNT
      0280C8h 4       MAC_PCU_FILTER_CCK_CNT
      0280CCh 4       MAC_PCU_PHY_ERR_CNT_1
      0280D0h 4       MAC_PCU_PHY_ERR_CNT_1_MASK
      0280D4h 4       MAC_PCU_PHY_ERR_CNT_2
      0280D8h 4       MAC_PCU_PHY_ERR_CNT_2_MASK
      0280DCh 4       MAC_PCU_TSF_THRESHOLD
      0280E0h 4       MAC_PCU_PHY_ERROR_EIFS_MASK
      0280E4h 4       MAC_PCU_PHY_ERR_CNT_3
      0280E8h 4       MAC_PCU_PHY_ERR_CNT_3_MASK
      0280ECh 4       MAC_PCU_BLUETOOTH_MODE
      0280F0h 4       MAC_PCU_BLUETOOTH_WEIGHTS
      0280F4h 4       MAC_PCU_BLUETOOTH_MODE2
      0280F8h 4       MAC_PCU_TXSIFS
      0280FCh 4       MAC_PCU_TXOP_X
      028100h 4       MAC_PCU_TXOP_0_3
      028104h 4       MAC_PCU_TXOP_4_7
      028108h 4       MAC_PCU_TXOP_8_11
      02810Ch 4       MAC_PCU_TXOP_12_15
      028110h 4       MAC_PCU_LOGIC_ANALYZER
      028114h 4       MAC_PCU_LOGIC_ANALYZER_32L
      028118h 4       MAC_PCU_LOGIC_ANALYZER_16U
      02811Ch 4       MAC_PCU_PHY_ERR_CNT_MASK_CONT
      028120h 4       MAC_PCU_AZIMUTH_MODE
      028124h 4       MAC_PCU_20_40_MODE
      028128h 4       MAC_PCU_RX_CLEAR_DIFF_CNT
      02812Ch 4       MAC_PCU_SELF_GEN_ANTENNA_MASK
      028130h 4       MAC_PCU_BA_BAR_CONTROL
      028134h 4       MAC_PCU_LEGACY_PLCP_SPOOF
      028138h 4       MAC_PCU_PHY_ERROR_MASK_CONT
      02813Ch 4       MAC_PCU_TX_TIMER
      028140h 4       MAC_PCU_TXBUF_CTRL
      028144h 4       MAC_PCU_MISC_MODE2     ;with extra bit in newer revision
      028148h 4       MAC_PCU_ALT_AES_MUTE_MASK
      02814Ch 4       MAC_PCU_AZIMUTH_TIME_STAMP
      028150h 4       MAC_PCU_MAX_CFP_DUR
      028154h 4       MAC_PCU_HCF_TIMEOUT
      028158h 4       MAC_PCU_BLUETOOTH_WEIGHTS2
      02815Ch 4       MAC_PCU_BLUETOOTH_TSF_BT_ACTIVE
      028160h 4       MAC_PCU_BLUETOOTH_TSF_BT_PRIORITY
      028164h 4       MAC_PCU_BLUETOOTH_MODE3
      028168h 4       MAC_PCU_BLUETOOTH_MODE4
      02816Ch 1x148   PAD0
      028200h 4x64    MAC_PCU_BT_BT[0..63]
      028300h 4       MAC_PCU_BT_BT_ASYNC
      028304h 4       MAC_PCU_BT_WL_1
      028308h 4       MAC_PCU_BT_WL_2
      02830Ch 4       MAC_PCU_BT_WL_3
      028310h 4       MAC_PCU_BT_WL_4
      028314h 4       MAC_PCU_COEX_EPTA
      028318h 4       MAC_PCU_COEX_LNAMAXGAIN1
      02831Ch 4       MAC_PCU_COEX_LNAMAXGAIN2
      028320h 4       MAC_PCU_COEX_LNAMAXGAIN3
      028324h 4       MAC_PCU_COEX_LNAMAXGAIN4
      028328h 4       MAC_PCU_BASIC_RATE_SET0
      02832Ch 4       MAC_PCU_BASIC_RATE_SET1
      028330h 4       MAC_PCU_BASIC_RATE_SET2
      028334h 4       MAC_PCU_BASIC_RATE_SET3
      028338h 4       MAC_PCU_RX_INT_STATUS0
      02833Ch 4       MAC_PCU_RX_INT_STATUS1
      028340h 4       MAC_PCU_RX_INT_STATUS2
      028344h 4       MAC_PCU_RX_INT_STATUS3
      028348h 4       HT_HALF_GI_RATE1
      02834Ch 4       HT_HALF_GI_RATE2
      028350h 4       HT_FULL_GI_RATE1
      028354h 4       HT_FULL_GI_RATE2
      028358h 4       LEGACY_RATE1
      02835Ch 4       LEGACY_RATE2
      028360h 4       LEGACY_RATE3
      028364h 4       RX_INT_FILTER          ;with extra bit in newer revision
      028368h 4       RX_INT_OVERFLOW
      02836Ch 4       RX_FILTER_THRESH(0)
      028370h 4       RX_FILTER_THRESH1
      028374h 4       RX_PRIORITY_THRESH0
      028378h 4       RX_PRIORITY_THRESH1
      02837Ch 4       RX_PRIORITY_THRESH2
      028380h 4       RX_PRIORITY_THRESH3
      028384h 4       RX_PRIORITY_OFFSET0
      028388h 4       RX_PRIORITY_OFFSET1
      02838Ch 4       RX_PRIORITY_OFFSET2
      028390h 4       RX_PRIORITY_OFFSET3
      028394h 4       RX_PRIORITY_OFFSET4
      028398h 4       RX_PRIORITY_OFFSET5
      02839Ch 4       MAC_PCU_BSSID2_L32
      0283A0h 4       MAC_PCU_BSSID2_U16
      0283A4h 4       MAC_PCU_TSF1_STATUS_L32
      0283A8h 4       MAC_PCU_TSF1_STATUS_U32
      0283ACh 4       MAC_PCU_TSF2_STATUS_L32
      0283B0h 4       MAC_PCU_TSF2_STATUS_U32
      0283B4h 1x76    PAD1
      028400h 4x64    MAC_PCU_TXBUF_BA[0..63]
      028500h 1x768   PAD2
      028800h 4x256   MAC_PCU_KEY_CACHE_1[0..255]
      028C00h 1x3072  PAD3
      029800h 4x512   MAC_PCU_BASEBAND_0[0..511]   ;\aka BB_xxx ports
      02A000h 4x2048  MAC_PCU_BASEBAND_1[0..2047]  ;/(see below)
      02C000h 4x1024  MAC_PCU_BASEBAND_2[0..1023]  ;\
      02D000h 4x1024  MAC_PCU_BASEBAND_3[0..1023]  ; after BB registers
      02E000h 4x512   MAC_PCU_BUF[0..511]          ;/
      02E800h -       unused/unspecified

bb_lc_reg.h (hw4.0)

     "BASEBAND_0"
      029800h 4       BB_TEST_CONTROLS
      029804h 4       BB_GEN_CONTROLS
      029808h 4       BB_TEST_CONTROLS_STATUS
      02980Ch 4       BB_TIMING_CONTROLS_1
      029810h 4       BB_TIMING_CONTROLS_2
      029814h 4       BB_TIMING_CONTROLS_3
      029818h 4       BB_D2_CHIP_ID
      02981Ch 4       BB_ACTIVE
      029820h 4       BB_TX_TIMING_1
      029824h 4       BB_TX_TIMING_2
      029828h 4       BB_TX_TIMING_3
      02982Ch 4       BB_ADDAC_PARALLEL_CONTROL
      029830h 1x4     PAD__1
      029834h 4       BB_XPA_TIMING_CONTROL
      029838h 4       BB_MISC_PA_CONTROL
      02983Ch 4       BB_TSTDAC_CONSTANT
      029840h 4       BB_FIND_SIGNAL_LOW
      029844h 4       BB_SETTLING_TIME
      029848h 4       BB_GAIN_FORCE_MAX_GAINS_B0
      02984Ch 4       BB_GAINS_MIN_OFFSETS_B0
      029850h 4       BB_DESIRED_SIGSIZE
      029854h 4       BB_TIMING_CONTROL_3A
      029858h 4       BB_FIND_SIGNAL
      02985Ch 4       BB_AGC
      029860h 4       BB_AGC_CONTROL
      029864h 4       BB_CCA_B0
      029868h 4       BB_SFCORR
      02986Ch 4       BB_SELF_CORR_LOW
      029870h 1x4     PAD__2
      029874h 4       BB_SYNTH_CONTROL
      029878h 4       BB_ADDAC_CLK_SELECT
      02987Ch 4       BB_PLL_CNTL
      029880h 1x128   PAD__3
      029900h 4       BB_VIT_SPUR_MASK_A
      029904h 4       BB_VIT_SPUR_MASK_B
      029908h 4       BB_PILOT_SPUR_MASK
      02990Ch 4       BB_CHAN_SPUR_MASK
      029910h 4       BB_SPECTRAL_SCAN
      029914h 4       BB_ANALOG_POWER_ON_TIME
      029918h 4       BB_SEARCH_START_DELAY
      02991Ch 4       BB_MAX_RX_LENGTH
      029920h 4       BB_TIMING_CONTROL_4
      029924h 4       BB_TIMING_CONTROL_5
      029928h 4       BB_PHYONLY_WARM_RESET
      02992Ch 4       BB_PHYONLY_CONTROL
      029930h 1x4     PAD__4
      029934h 4       BB_POWERTX_RATE1   ;Power TX 0..3
      029938h 4       BB_POWERTX_RATE2   ;Power TX 4..7
      02993Ch 4       BB_POWERTX_MAX     ;Power TX Flags
      029940h 4       BB_EXTENSION_RADAR
      029944h 4       BB_FRAME_CONTROL
      029948h 4       BB_TIMING_CONTROL_6
      02994Ch 4       BB_SPUR_MASK_CONTROLS
      029950h 4       BB_RX_IQ_CORR_B0
      029954h 4       BB_RADAR_DETECTION
      029958h 4       BB_RADAR_DETECTION_2
      02995Ch 4       BB_TX_PHASE_RAMP_B0
      029960h 4       BB_SWITCH_TABLE_CHN_B0
      029964h 4       BB_SWITCH_TABLE_COM1
      029968h 4       BB_CCA_CTRL_2_B0
      02996Ch 4       BB_SWITCH_TABLE_COM2
      029970h 4       BB_RESTART
      029974h 1x4     PAD__5
      029978h 4       BB_SCRAMBLER_SEED
      02997Ch 4       BB_RFBUS_REQUEST
      029980h 1x32    PAD__6
      0299A0h 4       BB_TIMING_CONTROL_11
      0299A4h 4       BB_MULTICHAIN_ENABLE
      0299A8h 4       BB_MULTICHAIN_CONTROL
      0299ACh 4       BB_MULTICHAIN_GAIN_CTRL
      0299B0h 1x4     PAD__7
      0299B4h 4       BB_ADC_GAIN_DC_CORR_B0
      0299B8h 4       BB_EXT_CHAN_PWR_THR_1
      0299BCh 4       BB_EXT_CHAN_PWR_THR_2_B0
      0299C0h 4       BB_EXT_CHAN_SCORR_THR
      0299C4h 4       BB_EXT_CHAN_DETECT_WIN
      0299C8h 4       BB_PWR_THR_20_40_DET
      0299CCh 1x4     PAD__8
      0299D0h 4       BB_SHORT_GI_DELTA_SLOPE
      0299D4h 1x8     PAD__9
      0299DCh 4       BB_CHANINFO_CTRL
      0299E0h 4       BB_HEAVY_CLIP_CTRL
      0299E4h 4       BB_HEAVY_CLIP_20
      0299E8h 4       BB_HEAVY_CLIP_40
      0299ECh 4       BB_RIFS_SRCH
      0299F0h 4       BB_IQ_ADC_CAL_MODE
      0299F4h 1x8     PAD__10
      0299FCh 4       BB_PER_CHAIN_CSD
      029A00h 4x128   BB_RX_OCGAIN[0..127]
      029C00h 4       BB_TX_CRC
      029C04h 1x12    PAD__11
      029C10h 4       BB_IQ_ADC_MEAS_0_B0
      029C14h 4       BB_IQ_ADC_MEAS_1_B0
      029C18h 4       BB_IQ_ADC_MEAS_2_B0
      029C1Ch 4       BB_IQ_ADC_MEAS_3_B0
      029C20h 4       BB_RFBUS_GRANT
      029C24h 4       BB_TSTADC
      029C28h 4       BB_TSTDAC
      029C2Ch 1x4     PAD__12
      029C30h 4       BB_ILLEGAL_TX_RATE
      029C34h 4       BB_SPUR_REPORT_B0
      029C38h 4       BB_CHANNEL_STATUS
      029C3Ch 4       BB_RSSI_B0
      029C40h 4       BB_SPUR_EST_CCK_REPORT_B0
      029C44h 1x104   PAD__13  ;(old 1x172)
      029CF0h 4       BB_CHAN_INFO_NOISE_PWR              ;\
      029CF4h 4       BB_CHAN_INFO_GAIN_DIFF              ; located HERE in
      029CF8h 4       BB_CHAN_INFO_FINE_TIMING            ; older revision
      029CFCh 4       BB_CHAN_INFO_GAIN_B0                ; (unlike below)
      029D00h 4x60    BB_CHAN_INFO_CHAN_TAB_B0[0..59]     ;/
      029CACh 4       BB_CHAN_INFO_NOISE_PWR              ;\
      029CB0h 4       BB_CHAN_INFO_GAIN_DIFF              ; located HERE in
      029CB4h 4       BB_CHAN_INFO_FINE_TIMING            ; newer revision
      029CB8h 4       BB_CHAN_INFO_GAIN_B0                ; (unlike above)
      029CBCh 4x60    BB_CHAN_INFO_CHAN_TAB_B0[0..59]     ;/
      029DACh 1x56    PAD__14  ;(old 1x528 at 9DF0h)
      029DE4h 4       BB_PAPRD_AM2AM_MASK                 ;\
      029DE8h 4       BB_PAPRD_AM2PM_MASK                 ;
      029DECh 4       BB_PAPRD_HT40_MASK                  ;
      029DF0h 4       BB_PAPRD_CTRL0                      ; exists ONLY in
      029DF4h 4       BB_PAPRD_CTRL1                      ; newer revision
      029DF8h 4       BB_PA_GAIN123                       ;
      029DFCh 4       BB_PA_GAIN45                        ;
      029E00h 4x8     BB_PAPRD_PRE_POST_SCALE_(0..7)      ;
      029E20h 4x120   BB_PAPRD_MEM_TAB[....]              ;/
     "BASEBAND_1"
      02A000h 4       BB_PEAK_DET_CTRL_1
      02A004h 4       BB_PEAK_DET_CTRL_2
      02A008h 4       BB_RX_GAIN_BOUNDS_1
      02A00Ch 4       BB_RX_GAIN_BOUNDS_2
      02A010h 4       BB_PEAK_DET_CAL_CTRL
      02A014h 4       BB_AGC_DIG_DC_CTRL
      02A018h 4       BB_AGC_DIG_DC_STATUS_I_B0
      02A01Ch 4       BB_AGC_DIG_DC_STATUS_Q_B0
      02A020h 1x468   PAD__15
      02A1F4h 4       BB_BBB_TXFIR_0
      02A1F8h 4       BB_BBB_TXFIR_1
      02A1FCh 4       BB_BBB_TXFIR_2
      02A200h 4       BB_MODES_SELECT
      02A204h 4       BB_BBB_TX_CTRL
      02A208h 4       BB_BBB_SIG_DETECT
      02A20Ch 4       BB_EXT_ATTEN_SWITCH_CTL_B0
      02A210h 4       BB_BBB_RX_CTRL_1
      02A214h 4       BB_BBB_RX_CTRL_2
      02A218h 4       BB_BBB_RX_CTRL_3
      02A21Ch 4       BB_BBB_RX_CTRL_4
      02A220h 4       BB_BBB_RX_CTRL_5
      02A224h 4       BB_BBB_RX_CTRL_6
      02A228h 4       BB_BBB_DAGC_CTRL
      02A22Ch 4       BB_FORCE_CLKEN_CCK
      02A230h 4       BB_RX_CLEAR_DELAY
      02A234h 4       BB_POWERTX_RATE3   ;Power TX 1L,2L,2S
      02A238h 4       BB_POWERTX_RATE4   ;Power TX 55L,55S,11L,11S
      02A23Ch 1x4     PAD__16
      02A240h 4       BB_CCK_SPUR_MIT
      02A244h 4       BB_PANIC_WATCHDOG_STATUS
      02A248h 4       BB_PANIC_WATCHDOG_CTRL_1
      02A24Ch 4       BB_PANIC_WATCHDOG_CTRL_2
      02A250h 4       BB_IQCORR_CTRL_CCK      ;with extra bit in newer revision
      02A254h 4       BB_BLUETOOTH_CNTL
      02A258h 4       BB_TPC_1
      02A25Ch 4       BB_TPC_2
      02A260h 4       BB_TPC_3
      02A264h 4       BB_TPC_4_B0
      02A268h 4       BB_ANALOG_SWAP
      02A26Ch 4       BB_TPC_5_B0
      02A270h 4       BB_TPC_6_B0
      02A274h 4       BB_TPC_7
      02A278h 4       BB_TPC_8
      02A27Ch 4       BB_TPC_9
      02A280h 4x32    BB_PDADC_TAB_B0[0..31]
      02A300h 4x16    BB_CL_TAB_B0[0..15]
      02A340h 4       BB_CL_MAP_0_B0
      02A344h 4       BB_CL_MAP_1_B0
      02A348h 4       BB_CL_MAP_2_B0
      02A34Ch 4       BB_CL_MAP_3_B0
      02A350h 1x8     PAD__17
      02A358h 4       BB_CL_CAL_CTRL
      02A35Ch 4       BB_CL_MAP_PAL_0_B0            ;\
      02A360h 4       BB_CL_MAP_PAL_1_B0            ; exists ONLY in
      02A364h 4       BB_CL_MAP_PAL_2_B0            ; newer revision
      02A368h 4       BB_CL_MAP_PAL_3_B0            ;/
      02A36Ch 1x28    PAD__18  ;(old 1x44 at A35Ch)
      02A388h 4       BB_RIFS
      02A38Ch 4       BB_POWERTX_RATE5   ;Power TX HT20_0..3
      02A390h 4       BB_POWERTX_RATE6   ;Power TX HT20_4..7
      02A394h 4       BB_TPC_10
      02A398h 4       BB_TPC_11_B0
      02A39Ch 4       BB_CAL_CHAIN_MASK
      02A3A0h 1x28    PAD__19
      02A3BCh 4       BB_POWERTX_SUB     ;Power TX Sub_for_2chain
      02A3C0h 4       BB_POWERTX_RATE7   ;Power TX HT40_0..3
      02A3C4h 4       BB_POWERTX_RATE8   ;Power TX HT40_4..7
      02A3C8h 4       BB_POWERTX_RATE9   ;Power TX DUP40/EXT20_CCK/OFDM
      02A3CCh 4       BB_POWERTX_RATE10  ;Power TX HT20_8..11
      02A3D0h 4       BB_POWERTX_RATE11  ;Power TX HT20/40_12/13
      02A3D4h 4       BB_POWERTX_RATE12  ;Power TX HT40_8..11
      02A3D8h 4       BB_FORCE_ANALOG
      02A3DCh 4       BB_TPC_12
      02A3E0h 4       BB_TPC_13
      02A3E4h 4       BB_TPC_14
      02A3E8h 4       BB_TPC_15
      02A3ECh 4       BB_TPC_16
      02A3F0h 4       BB_TPC_17
      02A3F4h 4       BB_TPC_18
      02A3F8h 4       BB_TPC_19
      02A3FCh 4       BB_TPC_20
      02A400h 4x32    BB_TX_GAIN_TAB_(1..32)
      02A480h 4x32    BB_TX_GAIN_TAB_PAL_(1..32)
      02A500h 1x24    PAD__20
      02A518h 4x16    BB_CALTX_GAIN_SET_(0,2,4,6,..,28,30)
      02A558h 4x96    BB_TXIQCAL_MEAS_B0[0..95]
      02A6D8h 4       BB_TXIQCAL_START
      02A6DCh 4       BB_TXIQCAL_CONTROL_0
      02A6E0h 4       BB_TXIQCAL_CONTROL_1
      02A6E4h 4       BB_TXIQCAL_CONTROL_2
      02A6E8h 4       BB_TXIQCAL_CONTROL_3
      02A6ECh 4       BB_TXIQ_CORR_COEFF_01_B0
      02A6F0h 4       BB_TXIQ_CORR_COEFF_23_B0
      02A6F4h 4       BB_TXIQ_CORR_COEFF_45_B0
      02A6F8h 4       BB_TXIQ_CORR_COEFF_67_B0
      02A6FCh 4       BB_TXIQ_CORR_COEFF_89_B0
      02A700h 4       BB_TXIQ_CORR_COEFF_AB_B0
      02A704h 4       BB_TXIQ_CORR_COEFF_CD_B0
      02A708h 4       BB_TXIQ_CORR_COEFF_EF_B0
      02A70Ch 4       BB_CAL_RXBB_GAIN_TBL_0
      02A710h 4       BB_CAL_RXBB_GAIN_TBL_4
      02A714h 4       BB_CAL_RXBB_GAIN_TBL_8
      02A718h 4       BB_CAL_RXBB_GAIN_TBL_12
      02A71Ch 4       BB_CAL_RXBB_GAIN_TBL_16
      02A720h 4       BB_CAL_RXBB_GAIN_TBL_20
      02A724h 4       BB_CAL_RXBB_GAIN_TBL_24
      02A728h 4       BB_TXIQCAL_STATUS_B0
      02A72Ch 4       BB_PAPRD_TRAINER_CNTL1        ;\
      02A730h 4       BB_PAPRD_TRAINER_CNTL2        ;
      02A734h 4       BB_PAPRD_TRAINER_CNTL3        ; exists ONLY in
      02A738h 4       BB_PAPRD_TRAINER_CNTL4        ; newer revision
      02A73Ch 4       BB_PAPRD_TRAINER_STAT1        ;
      02A740h 4       BB_PAPRD_TRAINER_STAT2        ;
      02A744h 4       BB_PAPRD_TRAINER_STAT3        ;/
      02A748h 1x144   PAD__21  ;(old 1x172 at A72Ch)
      02A7D8h 4       BB_FCAL_1
      02A7DCh 4       BB_FCAL_2_B0
      02A7E0h 4       BB_RADAR_BW_FILTER
      02A7E4h 4       BB_DFT_TONE_CTRL_B0
      02A7E8h 4       BB_THERM_ADC_1
      02A7ECh 4       BB_THERM_ADC_2
      02A7F0h 4       BB_THERM_ADC_3
      02A7F4h 4       BB_THERM_ADC_4
      02A7F8h 4       BB_TX_FORCED_GAIN
      02A7FCh 4       BB_ECO_CTRL
      02A800h 1x72    PAD__22
      02A848h 4       BB_GAIN_FORCE_MAX_GAINS_B1
      02A84Ch 4       BB_GAINS_MIN_OFFSETS_B1
      02A850h 1x432   PAD__23
      02AA00h 4x128   BB_RX_OCGAIN2[0..127]
      02AC00h 1x1548  PAD__24
      02B20Ch 4       BB_EXT_ATTEN_SWITCH_CTL_B1
      02B210h -       unused/unspecified

mac_pcu_reg.h (2) (hw4.0)

      02C000h 4x1024  MAC_PCU_BASEBAND_2[0..1023]  ;\
      02D000h 4x1024  MAC_PCU_BASEBAND_3[0..1023]  ; after BB registers
      02E000h 4x512   MAC_PCU_BUF[0..511]          ;/
      02E800h -       unused/unspecified

rdma_reg.h (hw4.0)

      030100h 4       DMA_CONFIG
      030104h 4       DMA_CONTROL
      030108h 4       DMA_SRC
      03010Ch 4       DMA_DEST
      030110h 4       DMA_LENGTH
      030114h 4       VMC_BASE
      030118h 4       INDIRECT_REG
      03011Ch 4       INDIRECT_RETURN
      030120h 4x16    RDMA_REGION_(0..15)_
      030160h 4       DMA_STATUS
      030164h 4       DMA_INT_EN
      030168h -       unused/unspecified

efuse_reg.h (hw4.0)

      031000h 4       EFUSE_WR_ENABLE_REG
      031004h 4       EFUSE_INT_ENABLE_REG
      031008h 4       EFUSE_INT_STATUS_REG
      03100Ch 4       BITMASK_WR_REG
      031010h 4       VDDQ_SETTLE_TIME_REG
      031014h 4       RD_STROBE_PW_REG
      031018h 4       PG_STROBE_PW_REG
      03101Ch 1x2020  PAD0
      031800h 4x512   EFUSE_INTF[0..511]
      032000h -       unused/unspecified

DSi Atheros Wifi - Internal I/O Map Summary (hw6)

Overall Summary (hw6.0)

      004000h 33Ch    (rtc_soc_reg.h)
      xxx240h 1Ch     (rtc_sync_reg.h)    ;-unknown base address
      005000h 164h    (rtc_wlan_reg.h)
      006000h 264h    (wlan_coex_reg.h)
      007000h 94h     (bt_coex_reg.h)
      008000h ..      MIT (what is that...?) (maybe related to MITSUMI mode?)
      00C000h 14h     (uart_reg.h)
      00D000h ...     DBG_UART (another UART ?)
      00E000h 38h     (umbox_wlan_reg.h)
      010000h 18h     Serial I2C/SPI (si_reg.h)
      010018h 18h     ADDR_ERROR (si_reg.h)
      014000h 170h    (gpio_athr_wlan_reg.h)
      018000h 130h    (mbox_wlan_reg.h)
      01A000h 2000h   WLAN_HOST_IF_WINDOW (mbox_wlan_reg.h)
      01C000h 748h    (analog_intf_athr_wlan_reg.h)
      020000h 130h    (wmac_dma_reg.h)
      020800h 24Ch    (wmac_qcu_reg.h)
      021000h 7FCh    (wmac_dcu_reg.h)
      028000h 1000h   (wmac_pcu_reg.h)
      029800h 3F8h    bb_reg.h (1) - bb_chn_reg_map
      029C00h 24h     bb_reg.h (2) - bb_mrc_reg_map
      029D00h 1Ch     bb_reg.h (3) - bb_bbb_reg_map
      029E00h 400h    bb_reg.h (4) - bb_agc_reg_map
      02A200h 5F8h    bb_reg.h (5) - bb_sm_reg_map
      02A800h 3F8h    bb_reg.h (6) - bb_chn1_reg_map
      02AE00h 400h    bb_reg.h (7) - bb_agc1_reg_map
      02B200h 5F8h    bb_reg.h (8) - bb_sm1_reg_map
      02C800h 400h    bb_reg.h (9) - bb_chn3_reg_map (DUMMY)
      02CE00h 184h    bb_reg.h (10) - bb_agc3_reg_map (mostly DUMMY)
      02D200h 600h    bb_reg.h (11) - bb_sm3_reg_map (DUMMY)
      02D800h 20h     bb_reg.h (12) - mit_local_reg_map, aka bb_mit_reg_map
      02E000h 4x2048  MAC_PCU_BUF (wmac_pcu_reg.h)
      030000h 1800h   EFUSE (efuse_wlan_reg.h)
      034000h 1Ch     STEREO 0 (stereo_reg.h)
      035000h 58h     (chk_sum_seg_acc_reg.h)
      036000h ?       STEREO 1 (maybe same format as STEREO 0 ?)
      038000h 3Ch     (mmac_reg.h)
      039000h 0Ch     (fpga_reg.h)
      040000h 8       (bridge_intr_reg.h)
      040100h 8       (mii_reg.h)
      040200h 28h     (mdio_reg.h)
      040800h 20h     (bridge_chain_gmac_0_rx_reg.h)
      040C00h 1Ch     (bridge_chain_gmac_0_tx_reg.h)
      050000h ..      SVD (what is that...?)
      054000h ...     (usb_cast_reg.h)    ;<--- located at 54000h (?)
      054100h ..      usb RX chain 0..5 at 00054100h+(0..5)*100h  (?)
      054700h ..      usb TX chain 0..5 at 00054700h+(0..5)*100h  (?)
      054C00h ...     UART2 (yet another UART ?)
      054D00h A8h     (rdma_reg.h)
      054E00h 50h     (athrI2cSlaveApbCsr.h)
      055000h 40h     I2S (mbox_i2s_reg.h)
      056000h ..      I2S_1 (maybe same format as above "mbox_i2s_reg.h"?)
      xxxxxxh A00h    (map_rf_reg.h)      ;\unknown base address
      xxxxxxh 20h     (odin_reg.h)        ;/

rtc_soc_reg.h (hw6.0)

      004000h 4       SOC_RESET_CONTROL
      004004h 4       SOC_TCXO_DETECT
      004008h 4       SOC_XTAL_TEST
      00400Ch 1x20    PAD0
      004020h 4       SOC_CPU_CLOCK
      004024h 1x4     PAD1
      004028h 4       SOC_CLOCK_CONTROL
      00402Ch 1x4     PAD2
      004030h 4       SOC_WDT_CONTROL             ;\
      004034h 4       SOC_WDT_STATUS              ;
      004038h 4       SOC_WDT                     ; Watchdog Timer
      00403Ch 4       SOC_WDT_COUNT               ;
      004040h 4       SOC_WDT_RESET               ;/
      004044h 4       SOC_INT_STATUS              ;-Interrupt Status
      004048h 4       SOC_LF_TIMER0               ;\
      00404Ch 4       SOC_LF_TIMER_COUNT0         ; Low-Freq Timer
      004050h 4       SOC_LF_TIMER_CONTROL0       ;
      004054h 4       SOC_LF_TIMER_STATUS0        ;/
      004058h 4       SOC_LF_TIMER1               ;\
      00405Ch 4       SOC_LF_TIMER_COUNT1         ; Low-Freq Timer
      004060h 4       SOC_LF_TIMER_CONTROL1       ;
      004064h 4       SOC_LF_TIMER_STATUS1        ;/
      004068h 4       SOC_LF_TIMER2               ;\
      00406Ch 4       SOC_LF_TIMER_COUNT2         ; Low-Freq Timer
      004070h 4       SOC_LF_TIMER_CONTROL2       ;
      004074h 4       SOC_LF_TIMER_STATUS2        ;/
      004078h 4       SOC_LF_TIMER3               ;\
      00407Ch 4       SOC_LF_TIMER_COUNT3         ; Low-Freq Timer
      004080h 4       SOC_LF_TIMER_CONTROL3       ;
      004084h 4       SOC_LF_TIMER_STATUS3        ;/
      004088h 4       SOC_HF_TIMER                ;\
      00408Ch 4       SOC_HF_TIMER_COUNT          ; High-Freq Timer
      004090h 4       SOC_HF_LF_COUNT       ;<--  ;
      004094h 4       SOC_HF_TIMER_CONTROL        ;
      004098h 4       SOC_HF_TIMER_STATUS         ;/
      00409Ch 4       SOC_RTC_CONTROL             ;\
      0040A0h 4       SOC_RTC_TIME                ;
      0040A4h 4       SOC_RTC_DATE                ;
      0040A8h 4       SOC_RTC_SET_TIME            ; Real-Time Clock
      0040ACh 4       SOC_RTC_SET_DATE            ;
      0040B0h 4       SOC_RTC_SET_ALARM           ;
      0040B4h 4       SOC_RTC_CONFIG              ;
      0040B8h 4       SOC_RTC_ALARM_STATUS        ;/
      0040BCh 4       SOC_UART_WAKEUP
      0040C0h 4       SOC_RESET_CAUSE
      0040C4h 4       SOC_SYSTEM_SLEEP
      0040C8h 4       SOC_SDIO_WRAPPER
      0040CCh 4       SOC_INT_STATUS1
      0040D0h 1x4     PAD3
      0040D4h 4       SOC_LPO_CAL_TIME                    ;\
      0040D8h 4       SOC_LPO_INIT_DIVIDEND_INT           ;
      0040DCh 4       SOC_LPO_INIT_DIVIDEND_FRACTION      ; LPO
      0040E0h 4       SOC_LPO_CAL                         ;
      0040E4h 4       SOC_LPO_CAL_TEST_CONTROL            ;
      0040E8h 4       SOC_LPO_CAL_TEST_STATUS             ;/
      0040ECh 4       LEGACY_SOC_CHIP_ID                  ;\Chip ID
      0040F0h 4       SOC_CHIP_ID                         ;/
      0040F4h 1x24    PAD4
      00410Ch 4       SOC_POWER_REG
      004110h 4       SOC_CORE_CLK_CTRL
      004114h 4       SOC_GPIO_WAKEUP_CONTROL
      004118h 1x252   PAD5
      004214h 4       SLEEP_RETENTION
      004218h 1x108   PAD6
      004284h 4       LP_PERF_COUNTER                     ;\
      004288h 4       LP_PERF_LIGHT_SLEEP                 ; Perf
      00428Ch 4       LP_PERF_DEEP_SLEEP                  ;
      004290h 4       LP_PERF_ON                          ;/
      004294h 1x20    PAD7
      0042A8h 4       CHIP_MODE
      0042ACh 4       CLK_REQ_FALL_EDGE
      0042B0h 4       OTP                                 ;\OTP
      0042B4h 4       OTP_STATUS                          ;/
      0042B8h 4       PMU
      0042BCh 4       PMU_CONFIG
      0042C0h 4       PMU_PAREG
      0042C4h 4       PMU_BYPASS
      0042C8h 1x20    PAD8
      0042DCh 4       THERM_CTRL1                         ;\
      0042E0h 4       THERM_CTRL2                         ; Therm
      0042E4h 4       THERM_CTRL3                         ;/
      0042E8h 4       LISTEN_MODE1
      0042ECh 4       LISTEN_MODE2
      0042F0h 4       AUDIO_PLL_CONFIG
      0042F4h 4       AUDIO_PLL_MODULATION
      0042F8h 4       AUDIO_PLL_MOD_STEP
      0042FCh 4       CURRENT_AUDIO_PLL_MODULATION
      004300h 4       ETH_PLL_CONFIG
      004304h 4       CPU_PLL_CONFIG
      004308h 4       BB_PLL_CONFIG
      00430Ch 4       ETH_XMII
      004310h 4       USB_PHY_CONFIG
      004314h 4       MITSUMI_INT_CONTROL_REG
      004318h 4       MITSUMI_INT_STATUS_REG
      00431Ch 4       CURRENT_WORKING_MODE
      004320h 4       RTC_SLEEP_COUNT
      004324h 4       MIT2_VAP
      004328h 4       SECOND_HOST_INFT
      00432Ch 4       SDIO_HOST
      004330h 4       ENTERPRISE_CONFIG
      004334h 4       RTC_DEBUG_BUS
      004338h 4       RTC_EXT_CLK_BUF

rtc_sync_reg.h (hw6.0)

      000000h 1x576   PAD__0
      000240h 4       RTC_SYNC_RESET
      000244h 4       RTC_SYNC_STATUS
      000248h 4       RTC_SYNC_DERIVED
      00024Ch 4       RTC_SYNC_FORCE_WAKE
      000250h 4       RTC_SYNC_INTR_CAUSE
      000254h 4       RTC_SYNC_INTR_ENABLE
      000258h 4       RTC_SYNC_INTR_MASK
      00025Ch ..      -

rtc_wlan_reg.h (hw6.0)

      005000h 4       WLAN_RESET_CONTROL
      005004h 4       WLAN_XTAL_CONTROL
      005008h 4       WLAN_REG_CONTROL0
      00500Ch 4       WLAN_REG_CONTROL1
      005010h 4       WLAN_QUADRATURE
      005014h 4       WLAN_PLL_CONTROL
      005018h 4       WLAN_PLL_SETTLE
      00501Ch 4       WLAN_XTAL_SETTLE
      005020h 4       WLAN_CLOCK_OUT
      005024h 4       WLAN_BIAS_OVERRIDE
      005028h 4       WLAN_RESET_CAUSE
      00502Ch 4       WLAN_SYSTEM_SLEEP
      005030h 4       WLAN_MAC_SLEEP_CONTROL
      005034h 4       WLAN_KEEP_AWAKE
      005038h 4       WLAN_DERIVED_RTC_CLK
      00503Ch 4       MAC_PCU_SLP32_MODE
      005040h 4       MAC_PCU_SLP32_WAKE
      005044h 4       MAC_PCU_SLP32_INC
      005048h 4       MAC_PCU_SLP_MIB1
      00504Ch 4       MAC_PCU_SLP_MIB2
      005050h 4       MAC_PCU_SLP_MIB3
      005054h 4       MAC_PCU_TSF_L32
      005058h 4       MAC_PCU_TSF_U32
      00505Ch 4       MAC_PCU_WBTIMER_0
      005060h 4       MAC_PCU_WBTIMER_1
      005064h 4x16    MAC_PCU_GENERIC_TIMERS[0..15]
      0050A4h 1x24    PAD__0
      0050BCh 4       MAC_PCU_GENERIC_TIMERS_MODE
      0050C0h 4       MAC_PCU_SLP1
      0050C4h 4       MAC_PCU_SLP2
      0050C8h 4       MAC_PCU_SLP3
      0050CCh 4       MAC_PCU_SLP4
      0050D0h 4       MAC_PCU_RESET_TSF
      0050D4h 4       MAC_PCU_TSF2_L32
      0050D8h 4       MAC_PCU_TSF2_U32
      0050DCh 4x16    MAC_PCU_GENERIC_TIMERS2[0..15]
      00511Ch 1x24    PAD__1
      005134h 4       MAC_PCU_GENERIC_TIMERS_MODE2
      005138h 1x12    PAD__2
      005144h 4       MAC_PCU_TSF_THRESHOLD
      005148h 4       WLAN_HT
      00514Ch 1x4     PAD__3
      005150h 4       MAC_PCU_GENERIC_TIMERS_TSF_SEL
      005154h 4       MAC_PCU_BMISS_TIMEOUT
      005158h 4       MAC_PCU_BMISS2_TIMEOUT
      00515Ch 4       RTC_AXI_AHB_BRIDGE
      005160h 4       UNIFIED_MAC_REVID
      005164h ..      -

wlan_coex_reg.h (hw6.0)

      006000h 4       MCI_COMMAND0
      006004h 4       MCI_COMMAND1
      006008h 4       MCI_COMMAND2
      00600Ch 4       MCI_RX_CTRL
      006010h 4       MCI_TX_CTRL
      006014h 4       MCI_MSG_ATTRIBUTES_TABLE
      006018h 4       MCI_SCHD_TABLE_0
      00601Ch 4       MCI_SCHD_TABLE_1
      006020h 4       MCI_GPM_0
      006024h 4       MCI_GPM_1
      006028h 4       MCI_INTERRUPT_RAW
      00602Ch 4       MCI_INTERRUPT_EN
      006030h 4       MCI_REMOTE_CPU_INT
      006034h 4       MCI_REMOTE_CPU_INT_EN
      006038h 4       MCI_INTERRUPT_RX_MSG_RAW
      00603Ch 4       MCI_INTERRUPT_RX_MSG_EN
      006040h 4       MCI_CPU_INT
      006044h 4       MCI_RX_STATUS
      006048h 4       MCI_CONT_STATUS
      00604Ch 4       MCI_BT_PRI0
      006050h 4       MCI_BT_PRI1
      006054h 4       MCI_BT_PRI2
      006058h 4       MCI_BT_PRI3
      00605Ch 4       MCI_BT_PRI
      006060h 4       MCI_WL_FREQ0
      006064h 4       MCI_WL_FREQ1
      006068h 4       MCI_WL_FREQ2
      00606Ch 4       MCI_GAIN
      006070h 4       MCI_WBTIMER1
      006074h 4       MCI_WBTIMER2
      006078h 4       MCI_WBTIMER3
      00607Ch 4       MCI_WBTIMER4
      006080h 4       MCI_MAXGAIN
      006084h 1x40    PAD__0
      0060ACh 4       BTCOEX_CTRL
      0060B0h 1x156   PAD__1
      00614Ch 4       BTCOEX_CTRL2
      006150h 1x260   PAD__2
      006254h 4       BTCOEX_DBG
      006258h 4       MCI_LAST_HW_MSG_HDR
      00625Ch 4       MCI_LAST_HW_MSG_BDY
      006260h 4       MCI_MAXGAIN_RST
      006264h ..      -

bt_coex_reg.h (hw6.0)

      007000h 4       BTCOEXCTRL                      ;\
      007004h 4       WBSYNC_PRIORITY1                ;
      007008h 4       WBSYNC_PRIORITY2                ;
      00700Ch 4       WBSYNC_PRIORITY3                ;
      007010h 4       BTCOEX0  ;SYNC_DUR              ;
      007014h 4       BTCOEX1  ;CLK_THRES             ;
      007018h 4       BTCOEX2  ;FRAME_THRES           ;
      00701Ch 4       BTCOEX3  ;CLK_CNT               ; moved from 004218h (hw4)
      007020h 4       BTCOEX4  ;FRAME_CNT             ; to 007000h (hw6)
      007024h 4       BTCOEX5  ;IDLE_CNT              ;
      007028h 4       BTCOEX6  ;IDLE_RESET_LVL_BITMAP ;
      00702Ch 4       LOCK                            ;
      007030h 4       NOLOCK_PRIORITY                 ;
      007034h 4       WBSYNC                          ;
      007038h 4       WBSYNC1                         ;
      00703Ch 4       WBSYNC2                         ;
      007040h 4       WBSYNC3                         ;
      007044h 4       WB_TIMER_TARGET                 ;
      007048h 4       WB_TIMER_SLOP                   ;
      00704Ch 4       BTCOEX_INT_EN                   ;
      007050h 4       BTCOEX_INT_STAT                 ;
      007054h 4       BTPRIORITY_INT_EN               ;
      007058h 4       BTPRIORITY_INT_STAT             ;
      00705Ch 4       BTPRIORITY_STOMP_INT_EN         ;
      007060h 4       BTPRIORITY_STOMP_INT_STAT       ;/
      007064h 4       ST_64_BIT                       ;\
      007068h 4       MESSAGE_WR                      ; moved from 004294h (hw4)
      00706Ch 4       MESSAGE_WR_P                    ; to 007064h (hw6)
      007070h 4       MESSAGE_RD                      ;
      007074h 4       MESSAGE_RD_P                    ;/
      007078h 4       BTPRIORITY_INT                  ;\
      00707Ch 4       SCO_PARAMS                      ;
      007080h 4       SCO_PRIORITY                    ;
      007084h 4       SCO_SYNC                        ; new, hw6.0 only
      007088h 4       BTCOEX_RAW_STAT                 ;
      00708Ch 4       BTPRIORITY_RAW_STAT             ;
      007090h 4       BTPRIORITY_STOMP_RAW_STAT       ;/

uart_reg.h (hw6.0)

      00C000h 4       UART_DATA
      00C004h 4       UART_CONTROL
      00C008h 4       UART_CLKDIV
      00C00Ch 4       UART_INT
      00C010h 4       UART_INT_EN
      00C014h ..      -
      00D000h ..      ??

umbox_wlan_reg.h (hw6.0)

      00E000h 4x2     UMBOX_FIFO[0..1]
      00E008h 4       UMBOX_FIFO_STATUS
      00E00Ch 4       UMBOX_DMA_POLICY
      00E010h 4       UMBOX0_DMA_RX_DESCRIPTOR_BASE
      00E014h 4       UMBOX0_DMA_RX_CONTROL
      00E018h 4       UMBOX0_DMA_TX_DESCRIPTOR_BASE
      00E01Ch 4       UMBOX0_DMA_TX_CONTROL
      00E020h 4       UMBOX_FIFO_TIMEOUT
      00E024h 4       UMBOX_INT_STATUS
      00E028h 4       UMBOX_INT_ENABLE
      00E02Ch 4       UMBOX_DEBUG
      00E030h 4       UMBOX_FIFO_RESET
      00E034h 4       UMBOX_HCI_FRAMER

Serial I2C/SPI (si_reg.h) (hw6.0)

      010000h 4       SI_CONFIG
      010004h 4       SI_CS
      010008h 4       SI_TX_DATA0
      01000Ch 4       SI_TX_DATA1
      010010h 4       SI_RX_DATA0
      010014h 4       SI_RX_DATA1

ADDR_ERROR (si_reg.h) (hw6.0)

      010018h 4       WLAN_APB_ADDR_ERROR_CONTROL ;\
      01001Ch 4       WLAN_APB_ADDR_ERROR_STATUS  ; ADDR_ERROR
      010020h 4       WLAN_AHB_ADDR_ERROR_CONTROL ; (located at 8xxxh in hw4)
      010024h 4       WLAN_AHB_ADDR_ERROR_STATUS  ;/
      010028h 4       WLAN_AHB_CONFIG
      01002Ch 4       WLAN_MEMORY_MAP

gpio_athr_wlan_reg.h (hw6.0)

      014000h 4       WLAN_GPIO_OUT_LOW        ;\
      014004h 4       WLAN_GPIO_OUT_W1TS_LOW   ;
      014008h 4       WLAN_GPIO_OUT_W1TC_LOW   ; GPIO Output Data
      01400Ch 4       WLAN_GPIO_OUT_HIGH       ; (direct, and Write-1-To-Set/Clr)
      014010h 4       WLAN_GPIO_OUT_W1TS_HIGH  ;
      014014h 4       WLAN_GPIO_OUT_W1TC_HIGH  ;/
      014018h 4       WLAN_GPIO_ENABLE_LOW                ;\
      01401Ch 4       WLAN_GPIO_ENABLE_W1TS_LOW           ;
      014020h 4       WLAN_GPIO_ENABLE_W1TC_LOW           ; GPIO Output Enable
      014024h 4       WLAN_GPIO_ENABLE_HIGH               ; (direct, and Set/Clr)
      014028h 4       WLAN_GPIO_ENABLE_W1TS_HIGH          ;
      01402Ch 4       WLAN_GPIO_ENABLE_W1TC_HIGH          ;/
      014030h 4       WLAN_GPIO_IN_LOW                       ;\
      014034h 4       WLAN_GPIO_STATUS_LOW                ;\ ; GPIO Input
      014038h 4       WLAN_GPIO_IN_HIGH                   ;  ;/
      01403Ch 4       WLAN_GPIO_STATUS_HIGH               ;
      014040h 4       WLAN_GPIO_STATUS_W1TS_LOW           ; GPIO Interrupt Status
      014044h 4       WLAN_GPIO_STATUS_W1TC_LOW           ; (direct, and Set/Clr)
      014048h 4       WLAN_GPIO_STATUS_W1TS_HIGH          ;
      01404Ch 4       WLAN_GPIO_STATUS_W1TC_HIGH          ;/
      014050h 4       WLAN_GPIO_PIN0   ;GPIO0 or SDIO_CMD
      014054h 4       WLAN_GPIO_PIN1   ;GPIO1 or SDIO_D3
      014058h 4       WLAN_GPIO_PIN2   ;GPIO2 or SDIO_D2
      01405Ch 4       WLAN_GPIO_PIN3   ;GPIO3 or SDIO_D1
      014060h 4       WLAN_GPIO_PIN4   ;GPIO4 or SDIO_D0
      014064h 4       WLAN_GPIO_PIN5   ;GPIO5 or SDIO_CLK
      014068h 4       WLAN_GPIO_PIN6   ;GPIO6
      01406Ch 4       WLAN_GPIO_PIN7   ;GPIO7
      014070h 4       WLAN_GPIO_PIN8   ;...
      014074h 4       WLAN_GPIO_PIN9   ;..
      014078h 4       WLAN_GPIO_PIN10
      01407Ch 4       WLAN_GPIO_PIN11
      014080h 4       WLAN_GPIO_PIN12
      014084h 4       WLAN_GPIO_PIN13
      014088h 4       WLAN_GPIO_PIN14
      01408Ch 4       WLAN_GPIO_PIN15
      014090h 4       WLAN_GPIO_PIN16
      014094h 4       WLAN_GPIO_PIN17
      014098h 4       WLAN_GPIO_PIN18
      01409Ch 4       WLAN_GPIO_PIN19
      0140A0h 4       WLAN_GPIO_PIN20
      0140A4h 4       WLAN_GPIO_PIN21
      0140A8h 4       WLAN_GPIO_PIN22
      0140ACh 4       WLAN_GPIO_PIN23
      0140B0h 4       WLAN_GPIO_PIN24
      0140B4h 4       WLAN_GPIO_PIN25
      0140B8h 4       WLAN_GPIO_PIN26
      0140BCh 4       WLAN_GPIO_PIN27
      0140C0h 4       WLAN_GPIO_PIN28
      0140C4h 4       WLAN_GPIO_PIN29
      0140C8h 4       WLAN_GPIO_PIN30
      0140CCh 4       WLAN_GPIO_PIN31
      0140D0h 4       WLAN_GPIO_PIN32
      0140D4h 4       WLAN_GPIO_PIN33
      0140D8h 4       WLAN_GPIO_PIN34
      0140DCh 4       WLAN_GPIO_PIN35
      0140E0h 4       WLAN_GPIO_PIN36
      0140E4h 4       WLAN_GPIO_PIN37
      0140E8h 4       WLAN_GPIO_PIN38
      0140ECh 4       WLAN_GPIO_PIN39
      0140F0h 4       WLAN_GPIO_PIN40
      0140F4h 4       WLAN_GPIO_PIN41
      0140F8h 4       WLAN_GPIO_PIN42
      0140FCh 4       WLAN_GPIO_PIN43
      014100h 4       WLAN_GPIO_PIN44
      014104h 4       WLAN_GPIO_PIN45
      014108h 4       WLAN_GPIO_PIN46
      01410Ch 4       WLAN_GPIO_PIN47
      014110h 4       WLAN_GPIO_PIN48
      014114h 4       WLAN_GPIO_PIN49
      014118h 4       WLAN_GPIO_PIN50
      01411Ch 4       WLAN_GPIO_PIN51
      014120h 4       WLAN_GPIO_PIN52
      014124h 4       WLAN_GPIO_PIN53
      014128h 4       WLAN_GPIO_PIN54
      01412Ch 4       WLAN_GPIO_PIN55
      014130h 4       WLAN_GPIO_PIN56
      014134h 4       SDIO
      014138h 4       WL_SOC_APB
      01413Ch 4       WLAN_SIGMA_DELTA
      014140h 4       WL_BOOTSTRAP
      014144h 4       CORE_BOOTSTRAP_LOW
      014148h 4       CORE_BOOTSTRAP_HIGH
      01414Ch 4       WLAN_DEBUG_CONTROL
      014150h 4       WLAN_DEBUG_INPUT_SEL
      014154h 4       WLAN_DEBUG_OUT
      014158h 4       WLAN_RESET_TUPLE_STATUS
      01415Ch 4       ANTENNA_CONTROL
      014160h 4       SDIO2
      014164h 4       SDHC
      014168h 4       AMBA_DEBUG_BUS
      01416Ch 4       CPU_MBIST

MBOX Registers (mbox_wlan_reg.h) (hw6.0)

      018000h 4x4     WLAN_MBOX_FIFO[0..3]
      018010h 4       WLAN_MBOX_FIFO_STATUS
      018014h 4       WLAN_MBOX_DMA_POLICY
      018018h 4       WLAN_MBOX0_DMA_RX_DESCRIPTOR_BASE   ;\
      01801Ch 4       WLAN_MBOX0_DMA_RX_CONTROL           ; MBOX 0
      018020h 4       WLAN_MBOX0_DMA_TX_DESCRIPTOR_BASE   ;
      018024h 4       WLAN_MBOX0_DMA_TX_CONTROL           ;/
      018028h 4       WLAN_MBOX1_DMA_RX_DESCRIPTOR_BASE   ;\
      01802Ch 4       WLAN_MBOX1_DMA_RX_CONTROL           ; MBOX 1
      018030h 4       WLAN_MBOX1_DMA_TX_DESCRIPTOR_BASE   ;
      018034h 4       WLAN_MBOX1_DMA_TX_CONTROL           ;/
      018038h 4       WLAN_MBOX2_DMA_RX_DESCRIPTOR_BASE   ;\
      01803Ch 4       WLAN_MBOX2_DMA_RX_CONTROL           ; MBOX 2
      018040h 4       WLAN_MBOX2_DMA_TX_DESCRIPTOR_BASE   ;
      018044h 4       WLAN_MBOX2_DMA_TX_CONTROL           ;/
      018048h 4       WLAN_MBOX3_DMA_RX_DESCRIPTOR_BASE   ;\
      01804Ch 4       WLAN_MBOX3_DMA_RX_CONTROL           ; MBOX 3
      018050h 4       WLAN_MBOX3_DMA_TX_DESCRIPTOR_BASE   ;
      018054h 4       WLAN_MBOX3_DMA_TX_CONTROL           ;/
      018058h 4       WLAN_MBOX_INT_STATUS                ;\Interrupt
      01805Ch 4       WLAN_MBOX_INT_ENABLE                ;/
      018060h 4       WLAN_INT_HOST
      018064h 1x28    PAD0
      018080h 4x8     WLAN_LOCAL_COUNT[0..7]
      0180A0h 4x8     WLAN_COUNT_INC[0..7]
      0180C0h 4x8     WLAN_LOCAL_SCRATCH[0..7]
      0180E0h 4       WLAN_USE_LOCAL_BUS
      0180E4h 4       WLAN_SDIO_CONFIG
      0180E8h 4       WLAN_MBOX_DEBUG
      0180ECh 4       WLAN_MBOX_FIFO_RESET
      0180F0h 4x4     WLAN_MBOX_TXFIFO_POP[0..3]
      018100h 4x4     WLAN_MBOX_RXFIFO_POP[0..3]
      018110h 4       WLAN_SDIO_DEBUG
      018114h 4       WLAN_GMBOX0_DMA_RX_DESCRIPTOR_BASE  ;\
      018118h 4       WLAN_GMBOX0_DMA_RX_CONTROL          ;
      01811Ch 4       WLAN_GMBOX0_DMA_TX_DESCRIPTOR_BASE  ; hw4.0 and hw6.0
      018120h 4       WLAN_GMBOX0_DMA_TX_CONTROL          ;
      018124h 4       WLAN_GMBOX_INT_STATUS               ;
      018128h 4       WLAN_GMBOX_INT_ENABLE               ;/
      01812Ch 4       STE_MODE                            ;<-- hw6.0 only
      018130h 1x7888  PAD1
      01A000h 4x2048  WLAN_HOST_IF_WINDOW[0..2047]

analog_intf_athr_wlan_reg.h (hw6.0)

      01C000h 4       RXRF_BIAS1
      01C004h 4       RXRF_BIAS2
      01C008h 4       RXRF_GAINSTAGES
      01C00Ch 4       RXRF_AGC
      01C010h 1x48    PAD__0
      01C040h 4       TXRF1
      01C044h 4       TXRF2
      01C048h 4       TXRF3
      01C04Ch 4       TXRF4
      01C050h 4       TXRF5
      01C054h 4       TXRF6
      01C058h 4       TXRF7
      01C05Ch 4       TXRF8
      01C060h 4       TXRF9
      01C064h 4       TXRF10
      01C068h 4       TXRF11
      01C06Ch 4       TXRF12
      01C070h 1x16    PAD__1
      01C080h 4       SYNTH1
      01C084h 4       SYNTH2
      01C088h 4       SYNTH3
      01C08Ch 4       SYNTH4
      01C090h 4       SYNTH5
      01C094h 4       SYNTH6
      01C098h 4       SYNTH7
      01C09Ch 4       SYNTH8
      01C0A0h 4       SYNTH9
      01C0A4h 4       SYNTH10
      01C0A8h 4       SYNTH11
      01C0ACh 4       SYNTH12
      01C0B0h 4       SYNTH13
      01C0B4h 4       SYNTH14
      01C0B8h 1x8     PAD__2
      01C0C0h 4       BIAS1
      01C0C4h 4       BIAS2
      01C0C8h 4       BIAS3
      01C0CCh 4       BIAS4
      01C0D0h 1x48    PAD__3
      01C100h 4       RXTX1
      01C104h 4       RXTX2
      01C108h 4       RXTX3
      01C10Ch 1x52    PAD__4
      01C140h 4       BB1
      01C144h 4       BB2
      01C148h 4       BB3
      01C14Ch 1x308   PAD__5
      01C280h 4       PLLCLKMODA
      01C284h 4       PLLCLKMODA2
      01C288h 4       TOP
      01C28Ch 4       THERM
      01C290h 4       XTAL
      01C294h 1x236   PAD__6
      01C380h 4       RBIST_CNTRL
      01C384h 4       TX_DC_OFFSET
      01C388h 4       TX_TONEGEN0
      01C38Ch 4       TX_TONEGEN1
      01C390h 4       TX_LFTONEGEN0
      01C394h 4       TX_LINEAR_RAMP_I
      01C398h 4       TX_LINEAR_RAMP_Q
      01C39Ch 4       TX_PRBS_MAG
      01C3A0h 4       TX_PRBS_SEED_I
      01C3A4h 4       TX_PRBS_SEED_Q
      01C3A8h 4       CMAC_DC_CANCEL
      01C3ACh 4       CMAC_DC_OFFSET
      01C3B0h 4       CMAC_CORR
      01C3B4h 4       CMAC_POWER
      01C3B8h 4       CMAC_CROSS_CORR
      01C3BCh 4       CMAC_I2Q2
      01C3C0h 4       CMAC_POWER_HPF
      01C3C4h 4       RXDAC_SET1
      01C3C8h 4       RXDAC_SET2
      01C3CCh 4       RXDAC_LONG_SHIFT
      01C3D0h 4       CMAC_RESULTS_I
      01C3D4h 4       CMAC_RESULTS_Q
      01C3D8h 1x872   PAD__7
      01C740h 4       PMU1
      01C744h 4       PMU2

wmac_dma_reg.h (hw6.0)

      020000h 1x8     PAD__0
      020008h 4       MAC_DMA_CR
      020004h 1x4     PAD__1
      02000Ch 1x4     PAD__1
      020014h 4       MAC_DMA_CFG
      020018h 4       MAC_DMA_RXBUFPTR_THRESH
      02001Ch 4       MAC_DMA_TXDPPTR_THRESH
      020020h 4       MAC_DMA_MIRT
      020024h 4       MAC_DMA_GLOBAL_IER
      020028h 4       MAC_DMA_TIMT_0
      02002Ch 4       MAC_DMA_RIMT
      020030h 4       MAC_DMA_TXCFG
      020034h 4       MAC_DMA_RXCFG
      020038h 4       MAC_DMA_RXJLA
      02003Ch 1x4     PAD__2
      020040h 4       MAC_DMA_MIBC
      020044h 4       MAC_DMA_TOPS
      020048h 4       MAC_DMA_RXNPTO
      02004Ch 4       MAC_DMA_TXNPTO
      020050h 4       MAC_DMA_RPGTO
      020054h 1x4     PAD__3
      020058h 4       MAC_DMA_MACMISC
      02005Ch 4       MAC_DMA_INTER
      020060h 4       MAC_DMA_DATABUF
      020064h 4       MAC_DMA_GTT
      020068h 4       MAC_DMA_GTTM
      02006Ch 4       MAC_DMA_CST
      020070h 4       MAC_DMA_RXDP_SIZE
      020074h 4       MAC_DMA_RX_QUEUE_HP_RXDP
      020078h 4       MAC_DMA_RX_QUEUE_LP_RXDP
      02007Ch 1x4     PAD__4
      020080h 4       MAC_DMA_ISR_P  - Primary Interrupt Status Register         ;\
      020084h 4       MAC_DMA_ISR_S0 - Secondary Interrupt 0 Status TX OK/DESC   ;
      020088h 4       MAC_DMA_ISR_S1 - Secondary Interrupt 1 Status TX ERR/EOL   ;
      02008Ch 4       MAC_DMA_ISR_S2 - Secondary Interrupt 2 Status TX URN/MISC  ;
      020090h 4       MAC_DMA_ISR_S3 - Secondary Interrupt 3 Status QCBR OVF/URN ;
      020094h 4       MAC_DMA_ISR_S4 - Secondary Interrupt 4 Status QTRIG        ;
      020098h 4       MAC_DMA_ISR_S5 - Secondary Interrupt 5 Status TIMERS       ;
      02009Ch 4       MAC_DMA_ISR_S6 - Secondary Interrupt 6 Status UNKNOWN?     ;/
      0200A0h 4       MAC_DMA_IMR_P  - Primary Interrupt Mask Register           ;\
      0200A4h 4       MAC_DMA_IMR_S0 - Secondary Interrupt 0 Mask TX OK/DESC     ;
      0200A8h 4       MAC_DMA_IMR_S1 - Secondary Interrupt 1 Mask TX ERR/EOL     ;
      0200ACh 4       MAC_DMA_IMR_S2 - Secondary Interrupt 2 Mask TX URN/MISC    ;
      0200B0h 4       MAC_DMA_IMR_S3 - Secondary Interrupt 3 Mask QCBR OVF/URN   ;
      0200B4h 4       MAC_DMA_IMR_S4 - Secondary Interrupt 4 Mask QTRIG          ;
      0200B8h 4       MAC_DMA_IMR_S5 - Secondary Interrupt 5 Mask TIMERS         ;
      0200BCh 4       MAC_DMA_IMR_S6 - Secondary Interrupt 6 Mask UNKNOWN?       ;/
      0200C0h 4       MAC_DMA_ISR_P_RAC - Primary Interrupt Read-and-Clear       ;\
      0200C4h 4       MAC_DMA_ISR_S0_S  - Secondary 0 Read-and-Clr TX OK/DESC    ;
      0200C8h 4       MAC_DMA_ISR_S1_S  - Secondary 1 Read-and-Clr TX ERR/EOL    ;
      0200CCh 4       MAC_DMA_ISR_S6_S  - Secondary 6? Read-and-Clr UNKNOWN? <-- ;
      0200D0h 4       MAC_DMA_ISR_S2_S  - Secondary 2? Read-and-Clr TX URN/MISC  ;
      0200D4h 4       MAC_DMA_ISR_S3_S  - Secondary 3? Read-and-Clr QCBR OVF/URN ;
      0200D8h 4       MAC_DMA_ISR_S4_S  - Secondary 4? Read-and-Clr QTRIG        ;
      0200DCh 4       MAC_DMA_ISR_S5_S  - Secondary 5? Read-and-Clr TIMERS       ;/
      0200E0h 4       MAC_DMA_DMADBG_0
      0200E4h 4       MAC_DMA_DMADBG_1
      0200E8h 4       MAC_DMA_DMADBG_2
      0200ECh 4       MAC_DMA_DMADBG_3
      0200F0h 4       MAC_DMA_DMADBG_4
      0200F4h 4       MAC_DMA_DMADBG_5
      0200F8h 4       MAC_DMA_DMADBG_6
      0200FCh 4       MAC_DMA_DMADBG_7
      020100h 4       MAC_DMA_QCU_TXDP_REMAINING_QCU_7_0
      020104h 4       MAC_DMA_QCU_TXDP_REMAINING_QCU_9_8
      020108h 4       MAC_DMA_TIMT_1       ;note: "MAC_DMA_TIMT_0" is at 020028h
      02010Ch 4       MAC_DMA_TIMT_2
      020110h 4       MAC_DMA_TIMT_3
      020114h 4       MAC_DMA_TIMT_4
      020118h 4       MAC_DMA_TIMT_5
      02011Ch 4       MAC_DMA_TIMT_6
      020120h 4       MAC_DMA_TIMT_7
      020124h 4       MAC_DMA_TIMT_8
      020128h 4       MAC_DMA_TIMT_9
      02012Ch 4       MAC_DMA_CHKACC

wmac_qcu_reg.h (hw6.0)

      020800h 4x10    MAC_QCU_TXDP[0..9]
      020828h 1x8     PAD__1
      020830h 4       MAC_QCU_STATUS_RING_START
      020834h 4       MAC_QCU_STATUS_RING_END
      020838h 4       MAC_QCU_STATUS_RING_CURRENT
      02083Ch 1x4     PAD__2
      020840h 4       MAC_QCU_TXE
      020844h 1x60    PAD__3
      020880h 4       MAC_QCU_TXD
      020884h 1x60    PAD__4
      0208C0h 4x10    MAC_QCU_CBR[0..9]
      0208E8h 1x24    PAD__5
      020900h 4x10    MAC_QCU_RDYTIME[0..9]
      020928h 1x24    PAD__6
      020940h 4       MAC_QCU_ONESHOT_ARM_SC
      020944h 1x60    PAD__7
      020980h 4       MAC_QCU_ONESHOT_ARM_CC
      020984h 1x60    PAD__8
      0209C0h 4x10    MAC_QCU_MISC[0..9]
      0209E8h 1x24    PAD__9
      020A00h 4x10    MAC_QCU_CNT[0..9]
      020A28h 1x24    PAD__10
      020A40h 4       MAC_QCU_RDYTIME_SHDN
      020A44h 4       MAC_QCU_DESC_CRC_CHK
      020A48h 4       MAC_QCU_EOL

wmac_dcu_reg.h (hw6.0)

      021000h 4x10    MAC_DCU_QCUMASK[0..9]
      021028h 1x8     PAD__1
      021030h 4       MAC_DCU_GBL_IFS_SIFS
      021034h 1x4     PAD__2
      021038h 4       MAC_DCU_TXFILTER_DCU0_31_0
      02103Ch 4       MAC_DCU_TXFILTER_DCU8_31_0
      021040h 4x10    MAC_DCU_LCL_IFS[0..9]
      021068h 1x8     PAD__3
      021070h 4       MAC_DCU_GBL_IFS_SLOT
      021074h 1x4     PAD__4
      021078h 4       MAC_DCU_TXFILTER_DCU0_63_32
      02107Ch 4       MAC_DCU_TXFILTER_DCU8_63_32
      021080h 4x10    MAC_DCU_RETRY_LIMIT[0..9]
      0210A8h 1x8     PAD__5
      0210B0h 4       MAC_DCU_GBL_IFS_EIFS
      0210B4h 1x4     PAD__6
      0210B8h 4       MAC_DCU_TXFILTER_DCU0_95_64
      0210BCh 4       MAC_DCU_TXFILTER_DCU8_95_64
      0210C0h 4x10    MAC_DCU_CHANNEL_TIME[0..9]
      0210E8h 1x8     PAD__7
      0210F0h 4       MAC_DCU_GBL_IFS_MISC
      0210F4h 1x4     PAD__8
      0210F8h 4       MAC_DCU_TXFILTER_DCU0_127_96
      0210FCh 4       MAC_DCU_TXFILTER_DCU8_127_96
      021100h 4x10    MAC_DCU_MISC[0..9]
      021128h 1x16    PAD__9
      021138h 4       MAC_DCU_TXFILTER_DCU1_31_0
      02113Ch 4       MAC_DCU_TXFILTER_DCU9_31_0
      021140h 4       MAC_DCU_SEQ
      021144h 1x52    PAD__10
      021178h 4       MAC_DCU_TXFILTER_DCU1_63_32
      02117Ch 4       MAC_DCU_TXFILTER_DCU9_63_32
      021180h 1x56    PAD__11
      0211B8h 4       MAC_DCU_TXFILTER_DCU1_95_64
      0211BCh 4       MAC_DCU_TXFILTER_DCU9_95_64
      0211C0h 1x56    PAD__12
      0211F8h 4       MAC_DCU_TXFILTER_DCU1_127_96
      0211FCh 4       MAC_DCU_TXFILTER_DCU9_127_96
      021200h 1x56    PAD__13
      021238h 4       MAC_DCU_TXFILTER_DCU2_31_0
      02123Ch 1x52    PAD__14
      021270h 4       MAC_DCU_PAUSE
      021274h 1x4     PAD__15
      021278h 4       MAC_DCU_TXFILTER_DCU2_63_32
      02127Ch 1x52    PAD__16
      0212B0h 4       MAC_DCU_WOW_KACFG
      0212B4h 1x4     PAD__17
      0212B8h 4       MAC_DCU_TXFILTER_DCU2_95_64
      0212BCh 1x52    PAD__18
      0212F0h 4       MAC_DCU_TXSLOT
      0212F4h 1x4     PAD__19
      0212F8h 4       MAC_DCU_TXFILTER_DCU2_127_96
      0212FCh 1x60    PAD__20
      021338h 4       MAC_DCU_TXFILTER_DCU3_31_0          ;\
      02133Ch 1x60    PAD__21                             ;
      021378h 4       MAC_DCU_TXFILTER_DCU3_63_32         ;
      02137Ch 1x60    PAD__22                             ;
      0213B8h 4       MAC_DCU_TXFILTER_DCU3_95_64         ;
      0213BCh 1x60    PAD__23                             ;
      0213F8h 4       MAC_DCU_TXFILTER_DCU3_127_96        ;/
      0213FCh 1x60    PAD__24
      021438h 4       MAC_DCU_TXFILTER_DCU4_31_0
      02143Ch 4       MAC_DCU_TXFILTER_CLEAR
      021440h 1x56    PAD__25
      021478h 4       MAC_DCU_TXFILTER_DCU4_63_32
      02147Ch 4       MAC_DCU_TXFILTER_SET
      021480h 1x56    PAD__26
      0214B8h 4       MAC_DCU_TXFILTER_DCU4_95_64
      0214BCh 1x60    PAD__27
      0214F8h 4       MAC_DCU_TXFILTER_DCU4_127_96
      0214FCh 1x60    PAD__28
      021538h 4       MAC_DCU_TXFILTER_DCU5_31_0          ;\
      02153Ch 1x60    PAD__29                             ;
      021578h 4       MAC_DCU_TXFILTER_DCU5_63_32         ;
      02157Ch 1x60    PAD__30                             ;
      0215B8h 4       MAC_DCU_TXFILTER_DCU5_95_64         ;
      0215BCh 1x60    PAD__31                             ;
      0215F8h 4       MAC_DCU_TXFILTER_DCU5_127_96        ;/
      0215FCh 1x60    PAD__32
      021638h 4       MAC_DCU_TXFILTER_DCU6_31_0          ;\
      02163Ch 1x60    PAD__33                             ;
      021678h 4       MAC_DCU_TXFILTER_DCU6_63_32         ;
      02167Ch 1x60    PAD__34                             ;
      0216B8h 4       MAC_DCU_TXFILTER_DCU6_95_64         ;
      0216BCh 1x60    PAD__35                             ;
      0216F8h 4       MAC_DCU_TXFILTER_DCU6_127_96        ;/
      0216FCh 1x60    PAD__36
      021738h 4       MAC_DCU_TXFILTER_DCU7_31_0          ;\
      02173Ch 1x60    PAD__37                             ;
      021778h 4       MAC_DCU_TXFILTER_DCU7_63_32         ;
      02177Ch 1x60    PAD__38                             ;
      0217B8h 4       MAC_DCU_TXFILTER_DCU7_95_64         ;
      0217BCh 1x60    PAD__39                             ;
      0217F8h 4       MAC_DCU_TXFILTER_DCU7_127_96        ;/

wmac_pcu_reg.h (1) (hw6.0)

      028000h 4       MAC_PCU_STA_ADDR_L32
      028004h 4       MAC_PCU_STA_ADDR_U16
      028008h 4       MAC_PCU_BSSID_L32
      02800Ch 4       MAC_PCU_BSSID_U16
      028010h 4       MAC_PCU_BCN_RSSI_AVE
      028014h 4       MAC_PCU_ACK_CTS_TIMEOUT
      028018h 4       MAC_PCU_BCN_RSSI_CTL
      02801Ch 4       MAC_PCU_USEC_LATENCY
      028020h 4       MAC_PCU_BCN_RSSI_CTL2
      028024h 4       MAC_PCU_BT_WL_1
      028028h 4       MAC_PCU_BT_WL_2
      02802Ch 4       MAC_PCU_BT_WL_3
      028030h 4       MAC_PCU_BT_WL_4
      028034h 4       MAC_PCU_COEX_EPTA
      028038h 4       MAC_PCU_MAX_CFP_DUR
      02803Ch 4       MAC_PCU_RX_FILTER
      028040h 4       MAC_PCU_MCAST_FILTER_L32
      028044h 4       MAC_PCU_MCAST_FILTER_U32
      028048h 4       MAC_PCU_DIAG_SW
      02804Ch 1x8     PAD__1
      028054h 4       MAC_PCU_TST_ADDAC
      028058h 4       MAC_PCU_DEF_ANTENNA
      02805Ch 4       MAC_PCU_AES_MUTE_MASK_0
      028060h 4       MAC_PCU_AES_MUTE_MASK_1
      028064h 4       MAC_PCU_GATED_CLKS
      028068h 4       MAC_PCU_OBS_BUS_2
      02806Ch 4       MAC_PCU_OBS_BUS_1
      028070h 4       MAC_PCU_DYM_MIMO_PWR_SAVE
      028074h 1x12    PAD__2
      028080h 4       MAC_PCU_LAST_BEACON_TSF
      028084h 4       MAC_PCU_NAV
      028088h 4       MAC_PCU_RTS_SUCCESS_CNT
      02808Ch 4       MAC_PCU_RTS_FAIL_CNT
      028090h 4       MAC_PCU_ACK_FAIL_CNT
      028094h 4       MAC_PCU_FCS_FAIL_CNT
      028098h 4       MAC_PCU_BEACON_CNT
      02809Ch 4       MAC_PCU_BEACON2_CNT
      0280A0h 4       MAC_PCU_BASIC_SET
      0280A4h 4       MAC_PCU_MGMT_SEQ
      0280A8h 4       MAC_PCU_BF_RPT1
      0280ACh 4       MAC_PCU_BF_RPT2
      0280B0h 4       MAC_PCU_TX_ANT_1
      0280B4h 4       MAC_PCU_TX_ANT_2
      0280B8h 4       MAC_PCU_TX_ANT_3
      0280BCh 4       MAC_PCU_TX_ANT_4
      0280C0h 4       MAC_PCU_XRMODE
      0280C4h 4       MAC_PCU_XRDEL
      0280C8h 4       MAC_PCU_XRTO
      0280CCh 4       MAC_PCU_XRCRP
      0280D0h 4       MAC_PCU_XRSTMP
      0280D4h 1x8     PAD__3
      0280DCh 4       MAC_PCU_SELF_GEN_DEFAULT
      0280E0h 4       MAC_PCU_ADDR1_MASK_L32
      0280E4h 4       MAC_PCU_ADDR1_MASK_U16
      0280E8h 4       MAC_PCU_TPC
      0280ECh 4       MAC_PCU_TX_FRAME_CNT
      0280F0h 4       MAC_PCU_RX_FRAME_CNT
      0280F4h 4       MAC_PCU_RX_CLEAR_CNT
      0280F8h 4       MAC_PCU_CYCLE_CNT
      0280FCh 4       MAC_PCU_QUIET_TIME_1
      028100h 4       MAC_PCU_QUIET_TIME_2
      028104h 1x4     PAD__4
      028108h 4       MAC_PCU_QOS_NO_ACK
      02810Ch 4       MAC_PCU_PHY_ERROR_MASK
      028110h 4       MAC_PCU_XRLAT
      028114h 4       MAC_PCU_RXBUF
      028118h 4       MAC_PCU_MIC_QOS_CONTROL
      02811Ch 4       MAC_PCU_MIC_QOS_SELECT
      028120h 4       MAC_PCU_MISC_MODE
      028124h 4       MAC_PCU_FILTER_OFDM_CNT
      028128h 4       MAC_PCU_FILTER_CCK_CNT
      02812Ch 4       MAC_PCU_PHY_ERR_CNT_1
      028130h 4       MAC_PCU_PHY_ERR_CNT_1_MASK
      028134h 4       MAC_PCU_PHY_ERR_CNT_2
      028138h 4       MAC_PCU_PHY_ERR_CNT_2_MASK
      02813Ch 1x8     PAD__5
      028144h 4       MAC_PCU_PHY_ERROR_EIFS_MASK
      028148h 1x8     PAD__6
      028150h 4       MAC_PCU_COEX_LNAMAXGAIN1
      028154h 4       MAC_PCU_COEX_LNAMAXGAIN2
      028158h 4       MAC_PCU_COEX_LNAMAXGAIN3
      02815Ch 4       MAC_PCU_COEX_LNAMAXGAIN4
      028160h 1x8     PAD__7
      028168h 4       MAC_PCU_PHY_ERR_CNT_3
      02816Ch 4       MAC_PCU_PHY_ERR_CNT_3_MASK
      028170h 4       MAC_PCU_BLUETOOTH_MODE
      028174h 1x4     PAD__8
      028178h 4       MAC_PCU_HCF_TIMEOUT
      02817Ch 4       MAC_PCU_BLUETOOTH_MODE2
      028180h 1x72    PAD__9
      0281C8h 4       MAC_PCU_BLUETOOTH_TSF_BT_ACTIVE
      0281CCh 4       MAC_PCU_BLUETOOTH_TSF_BT_PRIORITY
      0281D0h 4       MAC_PCU_TXSIFS
      0281D4h 4       MAC_PCU_BLUETOOTH_MODE3
      0281D8h 4       MAC_PCU_BLUETOOTH_MODE4
      0281DCh 4       MAC_PCU_BLUETOOTH_MODE5
      0281E0h 4       MAC_PCU_BLUETOOTH_WEIGHTS
      0281E4h 4       MAC_PCU_BT_BT_ASYNC
      0281E8h 1x4     PAD__10
      0281ECh 4       MAC_PCU_TXOP_X
      0281F0h 4       MAC_PCU_TXOP_0_3
      0281F4h 4       MAC_PCU_TXOP_4_7
      0281F8h 4       MAC_PCU_TXOP_8_11
      0281FCh 4       MAC_PCU_TXOP_12_15
      028200h 4       MAC_PCU_TDMA_TXFRAME_START_TIME_TRIGGER_LSB
      028204h 4       MAC_PCU_TDMA_TXFRAME_START_TIME_TRIGGER_MSB
      028208h 4       MAC_PCU_TDMA_SLOT_ALERT_CNTL
      02820Ch 1x80    PAD__11
      02825Ch 4       MAC_PCU_WOW1                ;WOW Misc
      028260h 4       MAC_PCU_WOW2                ;WOW AIFS/SLOT/TRY_CNT
      028264h 4       MAC_PCU_LOGIC_ANALYZER
      028268h 4       MAC_PCU_LOGIC_ANALYZER_32L
      02826Ch 4       MAC_PCU_LOGIC_ANALYZER_16U
      028270h 4       MAC_PCU_WOW3_BEACON_FAIL    ;WOW Beacon Fail Enable
      028274h 4       MAC_PCU_WOW3_BEACON         ;WOW Beacon Timeout
      028278h 4       MAC_PCU_WOW3_KEEP_ALIVE     ;WOW Keep-Alive Timeout
      02827Ch 4       MAC_PCU_WOW_KA        ;WOW Auto/Fail/BkoffCs Enable/Disable
      028280h 1x4     PAD__12
      028284h 4       PCU_1US
      028288h 4       PCU_KA
      02828Ch 4       WOW_EXACT                   ;WOW Exact Length/Offset 1
      028290h 1x4     PAD__13
      028294h 4       PCU_WOW4                    ;WOW Offset 0..3
      028298h 4       PCU_WOW5                    ;WOW Offset 4..7
      02829Ch 4       MAC_PCU_PHY_ERR_CNT_MASK_CONT
      0282A0h 1x96    PAD__14
      028300h 4       MAC_PCU_AZIMUTH_MODE
      028304h 1x16    PAD__15
      028314h 4       MAC_PCU_AZIMUTH_TIME_STAMP
      028318h 4       MAC_PCU_20_40_MODE
      02831Ch 4       MAC_PCU_H_XFER_TIMEOUT
      028320h 1x8     PAD__16
      028328h 4       MAC_PCU_RX_CLEAR_DIFF_CNT
      02832Ch 4       MAC_PCU_SELF_GEN_ANTENNA_MASK
      028330h 4       MAC_PCU_BA_BAR_CONTROL
      028334h 4       MAC_PCU_LEGACY_PLCP_SPOOF
      028338h 4       MAC_PCU_PHY_ERROR_MASK_CONT
      02833Ch 4       MAC_PCU_TX_TIMER
      028340h 4       MAC_PCU_TXBUF_CTRL
      028344h 4       MAC_PCU_MISC_MODE2
      028348h 4       MAC_PCU_ALT_AES_MUTE_MASK
      02834Ch 4       MAC_PCU_WOW6                ;;WOW RX Buf Start Addr (R)
      028350h 4       ASYNC_FIFO_REG1
      028354h 4       ASYNC_FIFO_REG2
      028358h 4       ASYNC_FIFO_REG3
      02835Ch 4       MAC_PCU_WOW5                ;WOW RX Abort Enable
      028360h 4       MAC_PCU_WOW_LENGTH1         ;WOW Pattern 0..3
      028364h 4       MAC_PCU_WOW_LENGTH2         ;WOW Pattern 4..7
      028368h 4       WOW_PATTERN_MATCH_LESS_THAN_256_BYTES
      02836Ch 1x4     PAD__17
      028370h 4       MAC_PCU_WOW4                ;WOW Pattern Enable/Detect
      028374h 4       WOW2_EXACT                  ;WOW Exact Length/Offset 2 ;\
      028378h 4       PCU_WOW6                    ;WOW Offset 8..11          ;
      02837Ch 4       PCU_WOW7                    ;WOW Offset 12..15         ;
      028380h 4       MAC_PCU_WOW_LENGTH3         ;WOW Pattern 8..11         ;
      028384h 4       MAC_PCU_WOW_LENGTH4         ;WOW Pattern 12..15        ;/
      028388h 4       MAC_PCU_LOCATION_MODE_CONTROL
      02838Ch 4       MAC_PCU_LOCATION_MODE_TIMER
      028390h 1x8     PAD__18
      028398h 4       MAC_PCU_BSSID2_L32
      02839Ch 4       MAC_PCU_BSSID2_U16
      0283A0h 4       MAC_PCU_DIRECT_CONNECT
      0283A4h 4       MAC_PCU_TID_TO_AC
      0283A8h 4       MAC_PCU_HP_QUEUE
      0283ACh 1x16    PAD__19
      0283BCh 4       MAC_PCU_AGC_SATURATION_CNT0
      0283C0h 4       MAC_PCU_AGC_SATURATION_CNT1
      0283C4h 4       MAC_PCU_AGC_SATURATION_CNT2
      0283C8h 4       MAC_PCU_HW_BCN_PROC1
      0283CCh 4       MAC_PCU_HW_BCN_PROC2
      0283D0h 4       MAC_PCU_MISC_MODE3
      0283D4h 4       MAC_PCU_MISC_MODE4
      0283D8h 1x4     PAD__20
      0283DCh 4       MAC_PCU_PS_FILTER
      0283E0h 4       MAC_PCU_BASIC_RATE_SET0
      0283E4h 4       MAC_PCU_BASIC_RATE_SET1
      0283E8h 4       MAC_PCU_BASIC_RATE_SET2
      0283ECh 4       MAC_PCU_BASIC_RATE_SET3
      0283F0h 1x16    PAD__21
      028400h 4x64    MAC_PCU_TXBUF_BA[0..63]
      028500h 4x64    MAC_PCU_BT_BT[0..63]
      028600h 4       MAC_PCU_RX_INT_STATUS0
      028604h 4       MAC_PCU_RX_INT_STATUS1
      028608h 4       MAC_PCU_RX_INT_STATUS2
      02860Ch 4       MAC_PCU_RX_INT_STATUS3
      028610h 4       HT_HALF_GI_RATE1
      028614h 4       HT_HALF_GI_RATE2
      028618h 4       HT_FULL_GI_RATE1
      02861Ch 4       HT_FULL_GI_RATE2
      028620h 4       LEGACY_RATE1
      028624h 4       LEGACY_RATE2
      028628h 4       LEGACY_RATE3
      02862Ch 4       RX_INT_FILTER
      028630h 4       RX_INT_OVERFLOW
      028634h 4       RX_FILTER_THRESH0
      028638h 4       RX_FILTER_THRESH1
      02863Ch 4       RX_PRIORITY_THRESH0
      028640h 4       RX_PRIORITY_THRESH1
      028644h 4       RX_PRIORITY_THRESH2
      028648h 4       RX_PRIORITY_THRESH3
      02864Ch 4       RX_PRIORITY_OFFSET0
      028650h 4       RX_PRIORITY_OFFSET1
      028654h 4       RX_PRIORITY_OFFSET2
      028658h 4       RX_PRIORITY_OFFSET3
      02865Ch 4       RX_PRIORITY_OFFSET4
      028660h 4       RX_PRIORITY_OFFSET5
      028664h 4       MAC_PCU_LAST_BEACON2_TSF
      028668h 4       MAC_PCU_PHY_ERROR_AIFS
      02866Ch 4       MAC_PCU_PHY_ERROR_AIFS_MASK
      028670h 4       MAC_PCU_FILTER_RSSI_AVE
      028674h 4       MAC_PCU_TBD_FILTER
      028678h 4       MAC_PCU_BT_ANT_SLEEP_EXTEND
      02867Ch 1x388   PAD__22
      028800h 4x512   MAC_PCU_KEY_CACHE[0..511]
      029000h 1x20480 PAD__23                     ;<-- this includes BB regs
      02E000h 4x2048  MAC_PCU_BUF[0..2047]        ;<-- this after BB regs

bb_reg.h (1) - bb_chn_reg_map (hw6.0)

      029800h 4       BB_TIMING_CONTROLS_1
      029804h 4       BB_TIMING_CONTROLS_2
      029808h 4       BB_TIMING_CONTROLS_3
      02980Ch 4       BB_TIMING_CONTROL_4
      029810h 4       BB_TIMING_CONTROL_5
      029814h 4       BB_TIMING_CONTROL_6
      029818h 4       BB_TIMING_CONTROL_11
      02981Ch 4       BB_SPUR_MASK_CONTROLS
      029820h 4       BB_FIND_SIGNAL_LOW
      029824h 4       BB_SFCORR
      029828h 4       BB_SELF_CORR_LOW
      02982Ch 4       BB_EXT_CHAN_SCORR_THR
      029830h 4       BB_EXT_CHAN_PWR_THR_2_B0
      029834h 4       BB_RADAR_DETECTION
      029838h 4       BB_RADAR_DETECTION_2
      02983Ch 4       BB_EXTENSION_RADAR
      029840h 1x64    PAD__0
      029880h 4       BB_MULTICHAIN_CONTROL
      029884h 4       BB_PER_CHAIN_CSD
      029888h 1x24    PAD__1
      0298A0h 4       BB_TX_CRC
      0298A4h 4       BB_TSTDAC_CONSTANT
      0298A8h 4       BB_SPUR_REPORT_B0
      0298ACh 1x4     PAD__2
      0298B0h 4       BB_TXIQCAL_CONTROL_3
      0298B4h 1x8     PAD__3
      0298BCh 4       BB_GREEN_TX_CONTROL_1
      0298C0h 4       BB_IQ_ADC_MEAS_0_B0
      0298C4h 4       BB_IQ_ADC_MEAS_1_B0
      0298C8h 4       BB_IQ_ADC_MEAS_2_B0
      0298CCh 4       BB_IQ_ADC_MEAS_3_B0
      0298D0h 4       BB_TX_PHASE_RAMP_B0
      0298D4h 4       BB_ADC_GAIN_DC_CORR_B0
      0298D8h 1x4     PAD__4
      0298DCh 4       BB_RX_IQ_CORR_B0
      0298E0h 1x4     PAD__5
      0298E4h 4       BB_PAPRD_AM2AM_MASK
      0298E8h 4       BB_PAPRD_AM2PM_MASK
      0298ECh 4       BB_PAPRD_HT40_MASK
      0298F0h 4       BB_PAPRD_CTRL0_B0
      0298F4h 4       BB_PAPRD_CTRL1_B0
      0298F8h 4       BB_PA_GAIN123_B0
      0298FCh 4       BB_PA_GAIN45_B0
      029900h 4       BB_PAPRD_PRE_POST_SCALE_0_B0
      029904h 4       BB_PAPRD_PRE_POST_SCALE_1_B0
      029908h 4       BB_PAPRD_PRE_POST_SCALE_2_B0
      02990Ch 4       BB_PAPRD_PRE_POST_SCALE_3_B0
      029910h 4       BB_PAPRD_PRE_POST_SCALE_4_B0
      029914h 4       BB_PAPRD_PRE_POST_SCALE_5_B0
      029918h 4       BB_PAPRD_PRE_POST_SCALE_6_B0
      02991Ch 4       BB_PAPRD_PRE_POST_SCALE_7_B0
      029920h 4x120   BB_PAPRD_MEM_TAB_B0[0..119]
      029B00h 4x60    BB_CHAN_INFO_CHAN_TAB_B0[0..59]
      029BF0h 4       BB_CHN_TABLES_INTF_ADDR
      029BF4h 4       BB_CHN_TABLES_INTF_DATA

bb_reg.h (2) - bb_mrc_reg_map (hw6.0)

      029C00h 4       BB_TIMING_CONTROL_3A
      029C04h 4       BB_LDPC_CNTL1
      029C08h 4       BB_LDPC_CNTL2
      029C0Ch 4       BB_PILOT_SPUR_MASK
      029C10h 4       BB_CHAN_SPUR_MASK
      029C14h 4       BB_SHORT_GI_DELTA_SLOPE
      029C18h 4       BB_ML_CNTL1
      029C1Ch 4       BB_ML_CNTL2
      029C20h 4       BB_TSTADC

bb_reg.h (3) - bb_bbb_reg_map (hw6.0)

      029D00h 4       BB_BBB_RX_CTRL_1
      029D04h 4       BB_BBB_RX_CTRL_2
      029D08h 4       BB_BBB_RX_CTRL_3
      029D0Ch 4       BB_BBB_RX_CTRL_4
      029D10h 4       BB_BBB_RX_CTRL_5
      029D14h 4       BB_BBB_RX_CTRL_6
      029D18h 4       BB_FORCE_CLKEN_CCK

bb_reg.h (4) - bb_agc_reg_map (hw6.0)

      029E00h 4       BB_SETTLING_TIME
      029E04h 4       BB_GAIN_FORCE_MAX_GAINS_B0
      029E08h 4       BB_GAINS_MIN_OFFSETS
      029E0Ch 4       BB_DESIRED_SIGSIZE
      029E10h 4       BB_FIND_SIGNAL
      029E14h 4       BB_AGC
      029E18h 4       BB_EXT_ATTEN_SWITCH_CTL_B0
      029E1Ch 4       BB_CCA_B0
      029E20h 4       BB_CCA_CTRL_2_B0
      029E24h 4       BB_RESTART
      029E28h 4       BB_MULTICHAIN_GAIN_CTRL
      029E2Ch 4       BB_EXT_CHAN_PWR_THR_1
      029E30h 4       BB_EXT_CHAN_DETECT_WIN
      029E34h 4       BB_PWR_THR_20_40_DET
      029E38h 4       BB_RIFS_SRCH
      029E3Ch 4       BB_PEAK_DET_CTRL_1
      029E40h 4       BB_PEAK_DET_CTRL_2
      029E44h 4       BB_RX_GAIN_BOUNDS_1
      029E48h 4       BB_RX_GAIN_BOUNDS_2
      029E4Ch 4       BB_PEAK_DET_CAL_CTRL
      029E50h 4       BB_AGC_DIG_DC_CTRL
      029E54h 4       BB_BT_COEX_1
      029E58h 4       BB_BT_COEX_2
      029E5Ch 4       BB_BT_COEX_3
      029E60h 4       BB_BT_COEX_4
      029E64h 4       BB_BT_COEX_5
      029E68h 4       BB_REDPWR_CTRL_1
      029E6Ch 4       BB_REDPWR_CTRL_2
      029E70h 1x272   PAD__0
      029F80h 4       BB_RSSI_B0
      029F84h 4       BB_SPUR_EST_CCK_REPORT_B0
      029F88h 4       BB_AGC_DIG_DC_STATUS_I_B0
      029F8Ch 4       BB_AGC_DIG_DC_STATUS_Q_B0
      029F90h 4       BB_DC_CAL_STATUS_B0
      029F94h 1x44    PAD__1
      029FC0h 4       BB_BBB_SIG_DETECT
      029FC4h 4       BB_BBB_DAGC_CTRL
      029FC8h 4       BB_IQCORR_CTRL_CCK
      029FCCh 4       BB_CCK_SPUR_MIT
      029FD0h 4       BB_MRC_CCK_CTRL
      029FD4h 4       BB_CCK_BLOCKER_DET
      029FD8h 1x40    PAD__2
      02A000h 4x128   BB_RX_OCGAIN[0..127]

bb_reg.h (5) - bb_sm_reg_map (hw6.0)

      02A200h 4       BB_D2_CHIP_ID
      02A204h 4       BB_GEN_CONTROLS
      02A208h 4       BB_MODES_SELECT
      02A20Ch 4       BB_ACTIVE
      02A210h 1x16    PAD__0
      02A220h 4       BB_VIT_SPUR_MASK_A
      02A224h 4       BB_VIT_SPUR_MASK_B
      02A228h 4       BB_SPECTRAL_SCAN
      02A22Ch 4       BB_RADAR_BW_FILTER
      02A230h 4       BB_SEARCH_START_DELAY
      02A234h 4       BB_MAX_RX_LENGTH
      02A238h 4       BB_FRAME_CONTROL
      02A23Ch 4       BB_RFBUS_REQUEST
      02A240h 4       BB_RFBUS_GRANT
      02A244h 4       BB_RIFS
      02A248h 4       BB_SPECTRAL_SCAN_2
      02A24Ch 1x4     PAD__1
      02A250h 4       BB_RX_CLEAR_DELAY
      02A254h 4       BB_ANALOG_POWER_ON_TIME
      02A258h 4       BB_TX_TIMING_1
      02A25Ch 4       BB_TX_TIMING_2
      02A260h 4       BB_TX_TIMING_3
      02A264h 4       BB_XPA_TIMING_CONTROL
      02A268h 1x24    PAD__2
      02A280h 4       BB_MISC_PA_CONTROL
      02A284h 4       BB_SWITCH_TABLE_CHN_B0
      02A288h 4       BB_SWITCH_TABLE_COM1
      02A28Ch 4       BB_SWITCH_TABLE_COM2
      02A290h 1x16    PAD__3
      02A2A0h 4       BB_MULTICHAIN_ENABLE
      02A2A4h 1x28    PAD__4
      02A2C0h 4       BB_CAL_CHAIN_MASK
      02A2C4h 4       BB_AGC_CONTROL
      02A2C8h 4       BB_IQ_ADC_CAL_MODE
      02A2CCh 4       BB_FCAL_1
      02A2D0h 4       BB_FCAL_2_B0
      02A2D4h 4       BB_DFT_TONE_CTRL_B0
      02A2D8h 4       BB_CL_CAL_CTRL
      02A2DCh 4       BB_CL_MAP_0_B0
      02A2E0h 4       BB_CL_MAP_1_B0
      02A2E4h 4       BB_CL_MAP_2_B0
      02A2E8h 4       BB_CL_MAP_3_B0
      02A2ECh 4       BB_CL_MAP_PAL_0_B0
      02A2F0h 4       BB_CL_MAP_PAL_1_B0
      02A2F4h 4       BB_CL_MAP_PAL_2_B0
      02A2F8h 4       BB_CL_MAP_PAL_3_B0
      02A2FCh 1x4     PAD__5
      02A300h 4x16    BB_CL_TAB_B0[0..15]
      02A340h 4       BB_SYNTH_CONTROL
      02A344h 4       BB_ADDAC_CLK_SELECT
      02A348h 4       BB_PLL_CNTL
      02A34Ch 4       BB_ANALOG_SWAP
      02A350h 4       BB_ADDAC_PARALLEL_CONTROL
      02A354h 1x4     PAD__6
      02A358h 4       BB_FORCE_ANALOG
      02A35Ch 1x4     PAD__7
      02A360h 4       BB_TEST_CONTROLS
      02A364h 4       BB_TEST_CONTROLS_STATUS
      02A368h 4       BB_TSTDAC
      02A36Ch 4       BB_CHANNEL_STATUS
      02A370h 4       BB_CHANINFO_CTRL
      02A374h 4       BB_CHAN_INFO_NOISE_PWR
      02A378h 4       BB_CHAN_INFO_GAIN_DIFF
      02A37Ch 4       BB_CHAN_INFO_FINE_TIMING
      02A380h 4       BB_CHAN_INFO_GAIN_B0
      02A384h 4       BB_SM_HIST
      02A388h 1x8     PAD__8
      02A390h 4       BB_SCRAMBLER_SEED
      02A394h 4       BB_BBB_TX_CTRL
      02A398h 4       BB_BBB_TXFIR_0
      02A39Ch 4       BB_BBB_TXFIR_1
      02A3A0h 4       BB_BBB_TXFIR_2
      02A3A4h 4       BB_HEAVY_CLIP_CTRL
      02A3A8h 4       BB_HEAVY_CLIP_20
      02A3ACh 4       BB_HEAVY_CLIP_40
      02A3B0h 4       BB_ILLEGAL_TX_RATE
      02A3B4h 1x12    PAD__9
      02A3C0h 4       BB_POWERTX_RATE1   ;Power TX 0..3
      02A3C4h 4       BB_POWERTX_RATE2   ;Power TX 4..7
      02A3C8h 4       BB_POWERTX_RATE3   ;Power TX 1L,2L,2S
      02A3CCh 4       BB_POWERTX_RATE4   ;Power TX 55L,55S,11L,11S
      02A3D0h 4       BB_POWERTX_RATE5   ;Power TX HT20_0..3
      02A3D4h 4       BB_POWERTX_RATE6   ;Power TX HT20_4..7
      02A3D8h 4       BB_POWERTX_RATE7   ;Power TX HT40_0..3
      02A3DCh 4       BB_POWERTX_RATE8   ;Power TX HT40_4..7
      02A3E0h 4       BB_POWERTX_RATE9   ;Power TX DUP40/EXT20_CCK/OFDM
      02A3E4h 4       BB_POWERTX_RATE10  ;Power TX HT20_8..11
      02A3E8h 4       BB_POWERTX_RATE11  ;Power TX HT20/40_12/13
      02A3ECh 4       BB_POWERTX_RATE12  ;Power TX HT40_8..11
      02A3F0h 4       BB_POWERTX_MAX     ;Power TX Flags
      02A3F4h 4       BB_POWERTX_SUB     ;Power TX Sub_for_2chain
      02A3F8h 4       BB_TPC_1
      02A3FCh 4       BB_TPC_2
      02A400h 4       BB_TPC_3
      02A404h 4       BB_TPC_4_B0
      02A408h 4       BB_TPC_5_B0
      02A40Ch 4       BB_TPC_6_B0
      02A410h 4       BB_TPC_7
      02A414h 4       BB_TPC_8
      02A418h 4       BB_TPC_9
      02A41Ch 4       BB_TPC_10
      02A420h 4       BB_TPC_11_B0
      02A424h 4       BB_TPC_12
      02A428h 4       BB_TPC_13
      02A42Ch 4       BB_TPC_14
      02A430h 4       BB_TPC_15
      02A434h 4       BB_TPC_16
      02A438h 4       BB_TPC_17
      02A43Ch 4       BB_TPC_18
      02A440h 4       BB_TPC_19_B0
      02A444h 4       BB_TPC_20
      02A448h 4       BB_THERM_ADC_1
      02A44Ch 4       BB_THERM_ADC_2
      02A450h 4       BB_THERM_ADC_3
      02A454h 4       BB_THERM_ADC_4
      02A458h 4       BB_TX_FORCED_GAIN
      02A45Ch 1x36    PAD__10
      02A480h 4x32    BB_PDADC_TAB_B0[0..31]
      02A500h 4x32    BB_TX_GAIN_TAB_(1..32)
      02A580h 4       BB_RTT_CTRL
      02A584h 4       BB_RTT_TABLE_SW_INTF_B0
      02A588h 4       BB_RTT_TABLE_SW_INTF_1_B0
      02A58Ch 4       BB_TX_GAIN_TAB_1_16_LSB_EXT
      02A590h 4       BB_TX_GAIN_TAB_17_32_LSB_EXT
      02A594h 1x108   PAD__11
      02A600h 4x16    BB_CALTX_GAIN_SET_(0,2,4,6,..,28,30)
      02A640h 1x4     PAD__12
      02A644h 4       BB_TXIQCAL_CONTROL_0
      02A648h 4       BB_TXIQCAL_CONTROL_1
      02A64Ch 4       BB_TXIQCAL_CONTROL_2
      02A650h 4       BB_TXIQ_CORR_COEFF_01_B0
      02A654h 4       BB_TXIQ_CORR_COEFF_23_B0
      02A658h 4       BB_TXIQ_CORR_COEFF_45_B0
      02A65Ch 4       BB_TXIQ_CORR_COEFF_67_B0
      02A660h 4       BB_TXIQ_CORR_COEFF_89_B0
      02A664h 4       BB_TXIQ_CORR_COEFF_AB_B0
      02A668h 4       BB_TXIQ_CORR_COEFF_CD_B0
      02A66Ch 4       BB_TXIQ_CORR_COEFF_EF_B0
      02A670h 4       BB_CAL_RXBB_GAIN_TBL_0
      02A674h 4       BB_CAL_RXBB_GAIN_TBL_4
      02A678h 4       BB_CAL_RXBB_GAIN_TBL_8
      02A67Ch 4       BB_CAL_RXBB_GAIN_TBL_12
      02A680h 4       BB_CAL_RXBB_GAIN_TBL_16
      02A684h 4       BB_CAL_RXBB_GAIN_TBL_20
      02A688h 4       BB_CAL_RXBB_GAIN_TBL_24
      02A68Ch 4       BB_TXIQCAL_STATUS_B0
      02A690h 4       BB_PAPRD_TRAINER_CNTL1
      02A694h 4       BB_PAPRD_TRAINER_CNTL2
      02A698h 4       BB_PAPRD_TRAINER_CNTL3
      02A69Ch 4       BB_PAPRD_TRAINER_CNTL4
      02A6A0h 4       BB_PAPRD_TRAINER_STAT1
      02A6A4h 4       BB_PAPRD_TRAINER_STAT2
      02A6A8h 4       BB_PAPRD_TRAINER_STAT3
      02A6ACh 1x276   PAD__13
      02A7C0h 4       BB_WATCHDOG_STATUS
      02A7C4h 4       BB_WATCHDOG_CTRL_1
      02A7C8h 4       BB_WATCHDOG_CTRL_2
      02A7CCh 4       BB_BLUETOOTH_CNTL
      02A7D0h 4       BB_PHYONLY_WARM_RESET
      02A7D4h 4       BB_PHYONLY_CONTROL
      02A7D8h 1x4     PAD__14
      02A7DCh 4       BB_ECO_CTRL
      02A7E0h 1x16    PAD__15
      02A7F0h 4       BB_TABLES_INTF_ADDR_B0
      02A7F4h 4       BB_TABLES_INTF_DATA_B0

bb_reg.h (6) - bb_chn1_reg_map (hw6.0)

      02A800h 1x48    PAD__0
      02A830h 4       BB_EXT_CHAN_PWR_THR_2_B1
      02A834h 1x116   PAD__1
      02A8A8h 4       BB_SPUR_REPORT_B1
      02A8ACh 1x20    PAD__2
      02A8C0h 4       BB_IQ_ADC_MEAS_0_B1
      02A8C4h 4       BB_IQ_ADC_MEAS_1_B1
      02A8C8h 4       BB_IQ_ADC_MEAS_2_B1
      02A8CCh 4       BB_IQ_ADC_MEAS_3_B1
      02A8D0h 4       BB_TX_PHASE_RAMP_B1
      02A8D4h 4       BB_ADC_GAIN_DC_CORR_B1
      02A8D8h 1x4     PAD__3
      02A8DCh 4       BB_RX_IQ_CORR_B1
      02A8E0h 1x16    PAD__4
      02A8F0h 4       BB_PAPRD_CTRL0_B1
      02A8F4h 4       BB_PAPRD_CTRL1_B1
      02A8F8h 4       BB_PA_GAIN123_B1
      02A8FCh 4       BB_PA_GAIN45_B1
      02A900h 4       BB_PAPRD_PRE_POST_SCALE_0_B1
      02A904h 4       BB_PAPRD_PRE_POST_SCALE_1_B1
      02A908h 4       BB_PAPRD_PRE_POST_SCALE_2_B1
      02A90Ch 4       BB_PAPRD_PRE_POST_SCALE_3_B1
      02A910h 4       BB_PAPRD_PRE_POST_SCALE_4_B1
      02A914h 4       BB_PAPRD_PRE_POST_SCALE_5_B1
      02A918h 4       BB_PAPRD_PRE_POST_SCALE_6_B1
      02A91Ch 4       BB_PAPRD_PRE_POST_SCALE_7_B1
      02A920h 4x120   BB_PAPRD_MEM_TAB_B1[0..119]
      02AB00h 4x60    BB_CHAN_INFO_CHAN_TAB_B1[0..59]
      02ABF0h 4       BB_CHN1_TABLES_INTF_ADDR
      02ABF4h 4       BB_CHN1_TABLES_INTF_DATA

bb_reg.h (7) - bb_agc1_reg_map (hw6.0)

      02AE00h 1x4     PAD__0
      02AE04h 4       BB_GAIN_FORCE_MAX_GAINS_B1
      02AE08h 1x16    PAD__1
      02AE18h 4       BB_EXT_ATTEN_SWITCH_CTL_B1
      02AE1Ch 4       BB_CCA_B1
      02AE20h 4       BB_CCA_CTRL_2_B1
      02AE24h 1x348   PAD__2
      02AF80h 4       BB_RSSI_B1
      02AF84h 4       BB_SPUR_EST_CCK_REPORT_B1
      02AF88h 4       BB_AGC_DIG_DC_STATUS_I_B1
      02AF8Ch 4       BB_AGC_DIG_DC_STATUS_Q_B1
      02AF90h 4       BB_DC_CAL_STATUS_B1
      02AF94h 1x108   PAD__3
      02B000h 4x128   BB_RX_OCGAIN2[0..127]

bb_reg.h (8) - bb_sm1_reg_map (hw6.0)

      02B200h 1x132   PAD__0
      02B284h 4       BB_SWITCH_TABLE_CHN_B1
      02B288h 1x72    PAD__1
      02B2D0h 4       BB_FCAL_2_B1
      02B2D4h 4       BB_DFT_TONE_CTRL_B1
      02B2D8h 1x4     PAD__2
      02B2DCh 4       BB_CL_MAP_0_B1
      02B2E0h 4       BB_CL_MAP_1_B1
      02B2E4h 4       BB_CL_MAP_2_B1
      02B2E8h 4       BB_CL_MAP_3_B1
      02B2ECh 4       BB_CL_MAP_PAL_0_B1
      02B2F0h 4       BB_CL_MAP_PAL_1_B1
      02B2F4h 4       BB_CL_MAP_PAL_2_B1
      02B2F8h 4       BB_CL_MAP_PAL_3_B1
      02B2FCh 1x4     PAD__3
      02B300h 4x16    BB_CL_TAB_B1[0..15]
      02B340h 1x64    PAD__4
      02B380h 4       BB_CHAN_INFO_GAIN_B1
      02B384h 1x128   PAD__5
      02B404h 4       BB_TPC_4_B1
      02B408h 4       BB_TPC_5_B1
      02B40Ch 4       BB_TPC_6_B1
      02B410h 1x16    PAD__6
      02B420h 4       BB_TPC_11_B1
      02B424h 1x28    PAD__7
      02B440h 4       BB_TPC_19_B1
      02B444h 1x60    PAD__8
      02B480h 4x32    BB_PDADC_TAB_B1[0..31]
      02B500h 1x132   PAD__9
      02B584h 4       BB_RTT_TABLE_SW_INTF_B1
      02B588h 4       BB_RTT_TABLE_SW_INTF_1_B1
      02B58Ch 1x196   PAD__10
      02B650h 4       BB_TXIQ_CORR_COEFF_01_B1
      02B654h 4       BB_TXIQ_CORR_COEFF_23_B1
      02B658h 4       BB_TXIQ_CORR_COEFF_45_B1
      02B65Ch 4       BB_TXIQ_CORR_COEFF_67_B1
      02B660h 4       BB_TXIQ_CORR_COEFF_89_B1
      02B664h 4       BB_TXIQ_CORR_COEFF_AB_B1
      02B668h 4       BB_TXIQ_CORR_COEFF_CD_B1
      02B66Ch 4       BB_TXIQ_CORR_COEFF_EF_B1
      02B670h 1x28    PAD__11
      02B68Ch 4       BB_TXIQCAL_STATUS_B1
      02B690h 1x352   PAD__12
      02B7F0h 4       BB_TABLES_INTF_ADDR_B1
      02B7F4h 4       BB_TABLES_INTF_DATA_B1

bb_reg.h (9) - bb_chn3_reg_map (hw6.0)

      02C800h 4x256   BB_DUMMY1[0..255]

bb_reg.h (10) - bb_agc3_reg_map (hw6.0)

      02CE00h 4       BB_DUMMY
      02CE04h 1x380   PAD__0
      02CF80h 4       BB_RSSI_B3

bb_reg.h (11) - bb_sm3_reg_map (hw6.0)

      02D200h 4x384   BB_DUMMY2[0..383]

bb_reg.h (12) - mit_local_reg_map, aka bb_mit_reg_map (hw6.0)

      02D800h 4       BB_MIT_RF_CNTL
      02D804h 4       BB_MIT_CCA_CNTL
      02D808h 4       BB_MIT_RSSI_CNTL_1
      02D80Ch 4       BB_MIT_RSSI_CNTL_2
      02D810h 4       BB_MIT_TX_CNTL
      02D814h 4       BB_MIT_RX_CNTL
      02D818h 4       BB_MIT_OUT_CNTL
      02D81Ch 4       BB_MIT_SPARE_CNTL

wmac_pcu_reg.h (2) (hw6.0)

      02E000h 4x2048  MAC_PCU_BUF[0..2047]

efuse_wlan_reg.h (hw6.0)

      030000h 4       EFUSE_WR_ENABLE_REG
      030004h 4       EFUSE_INT_ENABLE_REG
      030008h 4       EFUSE_INT_STATUS_REG
      03000Ch 4       BITMASK_WR_REG
      030010h 4       VDDQ_SETTLE_TIME_REG
      030014h 4       VDDQ_HOLD_TIME_REG
      030018h 4       RD_STROBE_PW_REG
      03001Ch 4       PG_STROBE_PW_REG
      030020h 4       PGENB_SETUP_HOLD_TIME_REG
      030024h 4       STROBE_PULSE_INTERVAL_REG
      030028h 4       CSB_ADDR_LOAD_SETUP_HOLD_REG
      03002Ch 1x2004  PAD0
      030800h 4x512   EFUSE_INTF0[0..511]
      031000h 4x512   EFUSE_INTF1[0..511]

stereo_reg.h (hw6.0)

      034000h 4       STEREO0_CONFIG              ;\Stereo 0
      034004h 4       STEREO0_VOLUME              ;/
      034008h 4       STEREO_MASTER_CLOCK         ;-Stereo Master
      03400Ch 4       STEREO0_TX_SAMPLE_CNT_LSB   ;\
      034010h 4       STEREO0_TX_SAMPLE_CNT_MSB   ; Stereo 0
      034014h 4       STEREO0_RX_SAMPLE_CNT_LSB   ;
      034018h 4       STEREO0_RX_SAMPLE_CNT_MSB   ;/

chk_sum_seg_acc_reg.h (hw6.0)

      035000h 4       CHKSUM_ACC_DMATX_CONTROL0
      035004h 4       CHKSUM_ACC_DMATX_CONTROL1
      035008h 4       CHKSUM_ACC_DMATX_CONTROL2
      03500Ch 4       CHKSUM_ACC_DMATX_CONTROL3
      035010h 4       CHKSUM_ACC_DMATX_DESC0
      035014h 4       CHKSUM_ACC_DMATX_DESC1
      035018h 4       CHKSUM_ACC_DMATX_DESC2
      03501Ch 4       CHKSUM_ACC_DMATX_DESC3
      035020h 4       CHKSUM_ACC_DMATX_DESC_STATUS
      035024h 4       CHKSUM_ACC_DMATX_ARB_CFG
      035028h 4       CHKSUM_ACC_RR_PKTCNT01
      03502Ch 4       CHKSUM_ACC_RR_PKTCNT23
      035030h 4       CHKSUM_ACC_TXST_PKTCNT
      035034h 4       CHKSUM_ACC_DMARX_CONTROL
      035038h 4       CHKSUM_ACC_DMARX_DESC
      03503Ch 4       CHKSUM_ACC_DMARX_DESC_STATUS
      035040h 4       CHKSUM_ACC_INTR
      035044h 4       CHKSUM_ACC_IMASK
      035048h 4       CHKSUM_ACC_ARB_BURST
      03504Ch 1x4     PAD__0
      035050h 4       CHKSUM_ACC_RESET_DMA
      035054h 4       CHKSUM_CONFIG

mmac_reg.h (hw6.0)

      038000h 4       RX_FRAME0
      038004h 4       RX_FRAME_0
      038008h 4       RX_FRAME1
      03800Ch 4       RX_FRAME_1
      038010h 4       MMAC_INTERRUPT_RAW
      038014h 4       MMAC_INTERRUPT_EN
      038018h 4       RX_PARAM1
      03801Ch 4       RX_PARAM0
      038020h 4       TX_COMMAND0
      038024h 4       TX_COMMAND
      038028h 4       TX_PARAM
      03802Ch 4       BEACON_PARAM
      038030h 4       BEACON
      038034h 4       TSF_L
      038038h 4       TSF_U

fpga_reg.h (hw6.0)

      039000h 4       FPGA_REG1
      039004h 4       FPGA_REG2
      039008h 4       FPGA_REG4

bridge_intr_reg.h (hw6.0)

      040000h 4       INTERRUPT
      040004h 4       INTERRUPT_MASK

mii_reg.h (hw6.0)

      040100h 4       MII0_CNTL
      040104h 4       STAT_CNTL

mdio_reg.h (hw6.0)

      040200h 4x8     MDIO_REG[0..7]
      040220h 4       MDIO_ISR
      040224h 4       PHY_ADDR

bridge_chain_gmac_0_rx_reg.h (hw6.0)

      040800h 4       GMAC_RX_0_DESC_START_ADDRESS
      040804h 4       GMAC_RX_0_DMA_START
      040808h 4       GMAC_RX_0_BURST_SIZE
      04080Ch 4       GMAC_RX_0_PKT_OFFSET
      040810h 4       GMAC_RX_0_CHECKSUM
      040814h 4       GMAC_RX_0_DBG_RX
      040818h 4       GMAC_RX_0_DBG_RX_CUR_ADDR
      04081Ch 4       GMAC_RX_0_DATA_SWAP

bridge_chain_gmac_0_tx_reg.h (hw6.0)

      040C00h 4       GMAC_TX_0_DESC_START_ADDRESS
      040C04h 4       GMAC_TX_0_DMA_START
      040C08h 4       GMAC_TX_0_INTERRUPT_LIMIT
      040C0Ch 4       GMAC_TX_0_BURST_SIZE
      040C10h 4       GMAC_TX_0_DBG_TX
      040C14h 4       GMAC_TX_0_DBG_TX_CUR_ADDR
      040C18h 4       GMAC_TX_0_DATA_SWAP

usb_cast_reg.h (hw6.0)

      054000h 4       ENDP0
      054004h 1x4     PAD0
      054008h 4       OUT1ENDP
      05400Ch 4       IN1ENDP
      054010h 4       OUT2ENDP
      054014h 4       IN2ENDP
      054018h 4       OUT3ENDP
      05401Ch 4       IN3ENDP
      054020h 4       OUT4ENDP
      054024h 4       IN4ENDP
      054028h 4       OUT5ENDP
      05402Ch 4       IN5ENDP
      054030h 1x92    PAD1
      05408Ch 4       USBMODESTATUS
      054090h 1x248   PAD2
      054188h 4       EPIRQ
      05418Ch 4       USBIRQ
      054190h 1x4     PAD3
      054194h 4       EPIEN
      054198h 4       PIEN
      05419Ch 1x8     PAD4
      0541A4h 4       FNCTRL
      0541A8h 1x20    PAD5
      0541BCh 4       OTGREG
      0541C0h 1x12    PAD6
      0541CCh 4       DMASTART
      0541D0h 4       DMASTOP
      0541D4h 1x556   PAD7
      054400h 4       EP0DMAADDR
      054404h 1x28    PAD8
      054420h 4       EP1DMAADDR
      054424h 1x8     PAD9
      05442Ch 4       OUT1DMACTRL
      054430h 1x16    PAD10
      054440h 4       EP2DMAADDR
      054444h 1x8     PAD11
      05444Ch 4       OUT2DMACTRL
      054450h 1x16    PAD12
      054460h 4       EP3DMAADDR
      054464h 1x8     PAD13
      05446Ch 4       OUT3DMACTRL
      054470h 1x16    PAD14
      054480h 4       EP4DMAADDR
      054484h 1x8     PAD15
      05448Ch 4       OUT4DMACTRL
      054490h 1x16    PAD16
      0544A0h 4       EP5DMAADDR
      0544A4h 1x8     PAD17
      0544ACh 4       OUT5DMACTRL
      0544B0h 1x539472 PAD18            ;pad to BASE + 84000h
      0D8000h 4       USB_IP_BASE

rdma_reg.h (formerly at 00030100h in hw4.0) (hw6.0)

      054D00h 4       DMA_CONFIG
      054D04h 4       DMA_CONTROL
      054D08h 4       DMA_SRC
      054D0Ch 4       DMA_DEST
      054D10h 4       DMA_LENGTH
      054D14h 4       VMC_BASE
      054D18h 4       INDIRECT_REG
      054D1Ch 4       INDIRECT_RETURN
      054D20h 4x16    RDMA_REGION_(0..15)_
      054DA0h 4       DMA_STATUS
      054DA4h 4       DMA_INT_EN

athrI2cSlaveApbCsr.h (hw6.0)

      054E00h 4       I2CFIFOCONTROL
      054E04h 4       I2CFIFOREADPTR
      054E08h 4       I2CFIFOREADUPDATE
      054E0Ch 4       I2CFIFOREADBASEADDR
      054E10h 4       I2CFIFOWRITEPTR
      054E14h 4       I2CFIFOWRITEUPDATE
      054E18h 4       I2CFIFOWRITEBASEADDR
      054E1Ch 4       I2CMEMCONTROL
      054E20h 4       I2CMEMBASEADDR
      054E24h 4       I2CREGREADDATA
      054E28h 4       I2CREGWRITEDATA
      054E2Ch 4       I2CREGCONTROL
      054E30h 4       I2CCSRREADDATA
      054E34h 4       I2CCSRWRITEDATA
      054E38h 4       I2CCSRCONTROL
      054E3Ch 4       I2CFILTERSIZE
      054E40h 4       I2CADDR
      054E44h 4       I2CINT
      054E48h 4       I2CINTEN
      054E4Ch 4       I2CINTCSR

mbox_i2s_reg.h (hw6.0)

      055000h 4x1     MBOX_FIFO    ;<-- defined as array of ONE word (?)
      055004h 4       MBOX_FIFO_STATUS
      055008h 4       MBOX_DMA_POLICY
      05500Ch 4       MBOX0_DMA_RX_DESCRIPTOR_BASE
      055010h 4       MBOX0_DMA_RX_CONTROL
      055014h 4       MBOX0_DMA_TX_DESCRIPTOR_BASE
      055018h 4       MBOX0_DMA_TX_CONTROL
      05501Ch 4       MBOX_FRAME
      055020h 4       FIFO_TIMEOUT
      055024h 4       MBOX_INT_STATUS
      055028h 4       MBOX_INT_ENABLE
      05502Ch 4       MBOX_FIFO_RESET
      055030h 4       MBOX_DEBUG_CHAIN0
      055034h 4       MBOX_DEBUG_CHAIN1
      055038h 4       MBOX_DEBUG_CHAIN0_SIGNALS
      05503Ch 4       MBOX_DEBUG_CHAIN1_SIGNALS

map_rf_reg.h (hw6.0)

      xxx000h 4x256   RAM1[0..255]
      xxx400h 4x12    INT_PENDING[0..11]
      xxx430h 4       BB_WR_MASK_0                ;\
      xxx434h 4       BB_WR_MASK_1                ; BB Write Mask 0..3
      xxx438h 4       BB_WR_MASK_2                ;
      xxx43Ch 4       BB_WR_MASK_3                ;/
      xxx440h 4       RF_WR_MASK_0                ;\RF Write Mask 0..1
      xxx444h 4       RF_WR_MASK_1                ;/
      xxx448h 4       BB_RD_MASK_0                ;\
      xxx44Ch 4       BB_RD_MASK_1                ; BB Read Mask 0..3
      xxx450h 4       BB_RD_MASK_2                ;
      xxx454h 4       BB_RD_MASK_3                ;/
      xxx458h 4       RF_RD_MASK_0                ;\RF Read Mask 0..1
      xxx45Ch 4       RF_RD_MASK_1                ;/
      xxx460h 4       INT_SRC
      xxx464h 1x924   PAD__0
      xxx800h 4x128   RAM2[0..127]

odin_reg.h (hw6.0)

      xxx000h 4       PHY_CTRL0
      xxx004h 4       PHY_CTRL1
      xxx008h 4       PHY_CTRL2
      xxx00Ch 4       PHY_CTRL3
      xxx010h 4       PHY_CTRL4
      xxx014h 4       PHY_CTRL5
      xxx018h 4       PHY_CTRL6
      xxx01Ch 4       PHY_STATUS

DSi Atheros Wifi - Internal I/O - Unknown and Unused Registers (hw2)

hw4.0 would have the following extra registers

      00D000h - DBG_UART Registers   ;\don't exist in hw2.0 ?
      00E000h - UMBOX Registers      ;/
      020000h - WMAC DMA and IRQ     ;\
      020800h - WMAC QCU Queue       ; these MIGHT EXIST in hw2.0, too ?
      021000h - WMAC DCU             ; (not defined in hw2.0 source code though)
      029800h - BB/LC Registers      ;/
      030100h - RDMA Registers       ;\don't exist in hw2.0 ?
      031000h - EFUSE Registers      ;/

some partial hw2.0 memory dump...

      000000 Deadc0de
      004000 sth (01 00 00 00, 00 00 00 00)                        ;"RTC"
      005000 Deadc0de
      008000 sth (00 00 00 00, 00 00 00 00)                        ;"VMC?"
      009000 Deadc0de           ;should contain UART etc. (maybe disabled?)
      014000 sth (00 00 00 00, 00 00 00 00) (--crash-- at 0140cx)  ;"GPIO?"
      015000 Deadc0de
      018000 sth (00 01 0E 00, 00 01 0E 00)                        ;\MBOX
      019000 sth (00 01 0E 00, 00 01 0E 00)                        ;/
      01A000 sth (00 01 0E 00, 00 01 0E 00)                        ;\MBOX:HOST_IF?
      01B000 sth (--crash-- at 01B00x)                             ;/
      01C000 sth (00 00 14 00, D8 48 45 0E)                        ;-ANALOG?
      01D000 Deadc0de
      020000 sth (00's)                                            ;\DMA?
      021000 sth (01 00 00 00, 02 00 00 00)                        ;/
      022000 sth (00's)                                            ;\   ;\same as
      023000 sth (01 00 00 00, 02 00 00 00)                        ;    ;/DMA?
      024000 sth (00's)                                            ; ??
      025000 sth (00's)                                            ;
      026000 sth (00's)                                            ;
      027000 sth (00's)                                            ;/
      028000 sth (<--- mac addr ---> 86 38)            ;\MAC_PCU?     mac_pcu.h ?
      029000 sth (14 E1 38 8A, 80 73 00 00)            ;/          ;\
      02A000 sth (00's)                                            ; BB at 29800h?
      02B000 sth (00's)                                            ;/
      02C000 sth (00's)                                            ;-
      02D000 sth (00's)                                            ;-
      02E000 sth (00's)                                            ;-
      02F000 sth (00's)                                            ;-
      030000 Deadc0de              ;RDMA?? and (not?) EFUSE??
      040000 Deadbeef        ;\
      050000 Deadbeef        ;
      060000 Deadbeef        ;
      070000 Deadbeef        ;/
      080000 004F1B74        ;\
      090000 004F1B74        ;
      0A0000 004F1B74        ; mirror of ROM word at [0F3FF8] (second-last-word)
      0B0000 004F1B74        ;
      0C0000 004F1B74        ;
      0D0000 004F1B74        ;/
      0E0000 sth (06 10 00 00, 21 22 22 22)   ;\80K ROM (14000h bytes)
      0F0000 sth (00 00 05 60, FF DF FF FF)   ;/
      0F4000 004F1B74        ;-mirror of ROM word at [0F3FF8] (second-last-word)
      100000 sth (48 0F 8E 00, 70 14 50 00)   ;\
      110000 sth                              ; 184K RAM (2E000h bytes)
      120000 sth                              ;/
      12E000 98A8A2AA        ;\
      ...                    ;
      1FF000 98A8A2AA        ;/
      200000 Deadbeef        ;\
      300000 Deadbeef        ;/
      00400000 looks like mirror of 000000
      0041B000 looks like mirror of 01B000 --crash--
      ...      probably more mirrors...
      FFC00000 looks like mirror of 000000
      FFC1B000 looks like mirror of 01B000 --crash--
      ...      probably more mirrors till FFFFFFFF

some partial hw4.0 memory dump...

      000000 zerofilled
      004000 sth (01 00 00 00, 00 00 00 00)                        ;"RTC"
      005000 zerofilled
      040000 Deadbeef
      080000 zerofilled
      0E0000 06 10 00 00 21 22 22 22 00 00 00 E0 83 00 8E 00 ...   ;ROM?
      109DC0 zerofilled                                            ;ROM?
      10C000 14 19 52 00 ...                                       ;ROM?
      114000 zerofilled                                            ;ROM?
      120000 A0 B2 52 00     ;=52B2A0h (app_defined_area)   ;RAM
      140000 zerofilled
      200000 Deadbeef
      400000..FFFFFFFF not checked (probably mirrors of above?)

DSi Atheros Wifi - Internal I/O - 004000h - RTC/Clock SOC (hw2/hw4/hw6)

ATH:004000h - WLAN/SOC_RESET_CONTROL ;hw2/hw4/hw6

      0      SI0_RST
      1      UART_RST
      2      MBOX_RST
      3      -
      4      hw2/hw4: MAC_WARM_RST  ;-moved to 005000h.bit0 in hw6  ;\hw2/hw4 only
      5      hw2/hw4: MAC_COLD_RST  ;-moved to 005000h.bit1 in hw6  ;/
      6      CPU_WARM_RST
      7      hw2/hw4: WARM_RST      ;-moved to 005000h.bit2 in hw6  ;-hw2/hw4 only
      8      COLD_RST (0=no change, 1=reset)  ;-also in 005000h.bit3 in hw6
      9      RST_OUT
      10     hw2/hw4: VMC_REMAP_RESET   ;removed in hw6             ;-hw2/hw4 only
      11     CPU_INIT_RESET
      12     hw4: BB_WARM_RST       ;-moved to 005000h.bit4 in hw6  ;\hw4 only
      13     hw4: BB_COLD_RST       ;-moved to 005000h.bit5 in hw6  ; (not hw2, and
      14     hw4: DEBUG_UART_RST    ;-moved to bit16 in hw6         ;/moved in hw6)
      12     hw6: MIT_ADAPTOR_RST                           ;\
      13     hw6: MIT_REG_MAPPING_RST                       ;
      14-15  hw6: -                                         ;
      16     hw6: DEBUG_UART_RST ;<-- moved from old bit14  ;
      17     hw6: UART2_RST                                 ;
      18     hw6: CHECKSUM_ACC_RST                          ;
      19     hw6: I2S_MBOX_RST                              ;
      20     hw6: I2S_RST                                   ;
      21     hw6: GE0_RST                                   ;
      22     hw6: MDIO_RST                                  ; hw6
      23     hw6: MMAC_RST                                  ;
      24     hw6: USB_RST                                   ;
      25     hw6: USB_PHY_RST                               ;
      26     hw6: USB_PHY_ARST                              ;
      27     hw6: I2C_SLAVE_RST                             ;
      28     hw6: I2S_1_MBOX_RST                            ;
      29     hw6: I2S_1_RST                                 ;
      30     hw6: SPI2_RST                                  ;
      31     hw6: SDIO2_RST                                 ;/

ATH:004008h - WLAN_TCXO_DETECT ;hw2/hw4 at this address
ATH:004004h - SOC_TCXO_DETECT ;hw6 at this address (unlike hw2/hw4)

      0      PRESENT

ATH:00400Ch - WLAN_XTAL_TEST ;hw2/hw4 at this address
ATH:004008h - SOC_XTAL_TEST ;hw6 at this address (unlike hw2/hw4)

      0      NOTCXODET

ATH:004020h - WLAN/SOC_CPU_CLOCK ;hw2/hw4/hw6

      0-1    STANDARD

ATH:004028h - WLAN/SOC_CLOCK_CONTROL ;hw2/hw4/hw6

      0      SI0_CLK
      1      hw2: UART_CLK      ;0=enable?    ;<-- hw2 only (removed in hw4/hw6)
      2      LF_CLK32

     ______________________________ Watchdog Timer ______________________________

ATH:004030h - WLAN/SOC_WDT_CONTROL - Watchdog Timer Control ;hw2/hw4/hw6

      0-2    ACTION

ATH:004034h - WLAN/SOC_WDT_STATUS - Watchdog Interrupt Status ;hw2/hw4/hw6

      0      INTERRUPT

ATH:004038h - WLAN/SOC_WDT - Watchdog Timer Target ;hw2/hw4/hw6

      0-21   TARGET

ATH:00403Ch - WLAN/SOC_WDT_COUNT - Watchdog Timer Count ;hw2/hw4/hw6

      0-21   VALUE

ATH:004040h - WLAN/SOC_WDT_RESET - Watchdog Timer Reset ;hw2/hw4/hw6

      0      VALUE

     _____________________________ Interrupt Status _____________________________

ATH:004044h - WLAN/SOC_INT_STATUS ;hw2/hw4/hw6

      0      WDT_INT        ;-Watchdog Timer
      1      ERROR
      2      UART           ;-Serial UART
      3      GPIO           ;-GPIO
      4      SI             ;-Serial I2C/SPI
      5      KEYPAD
      6      LF_TIMER0      ;\
      7      LF_TIMER1      ; Low-Freq Timer 0..3
      8      LF_TIMER2      ; and
      9      LF_TIMER3      ; High-Freq Timer
      10     HF_TIMER       ;/
      11     RTC_ALARM      ;-Real-Time Clock Alarm
      12     MAILBOX
      13     MAC            ;-maybe this is "MAC's INTA#" (see WMAC IRQ) ?
      14     RTC_POWER
      15     hw4/hw6: BTCOEX   ;Bluetooth Coex      ;\
      16     hw4/hw6: RDMA                          ;
      17     hw4/hw6: GENERIC_MBOX  (aka GMBOX)     ; hw4/hw6
      18     hw4/hw6: UART_MBOX                     ;
      19     hw4/hw6: EFUSE_OVERWRITE               ;
      20     hw4/hw6: THERM                         ;
      21     hw4/hw6: HCI_UART                      ;/
      22     hw6: MODE_SWITCH                       ;\
      23     hw6: RF_SLEEP_RISING                   ;
      24     hw6: BBP_SLEEP_RISING                  ;
      25     hw6: FLIGHT_MODE                       ;
      26     hw6: MIT_REG_ACCESS                    ; hw6 only
      27     hw6: MMAC                              ;
      28     hw6: USBIP                             ;
      29     hw6: USBDMA                            ;
      30     hw6: SDIO2_MBOX                        ;
      31     hw6: STE_MBOX                          ;/

ATH:0040CCh - WLAN/SOC_INT_STATUS1 ;hw6

      0      MAC_1                                  ;\
      1      MAC_2                                  ;
      2      MAC_3                                  ;
      3      MAC_4                                  ; hw6 only
      4      CKSUM                                  ; (additional bits, extending
      5      I2C_S                                  ; the bits in port 004044h)
      6      GMAC                                   ;
      7      MDIO                                   ;
      8      I2S                                    ;
      9      I2S_1                                  ;/

     __________________ Low-Freq Timer 0-3 and High-Freq Timer __________________

ATH:004048h - WLAN/SOC_LF_TIMER0 ;hw2/hw4/hw6
ATH:004058h - WLAN/SOC_LF_TIMER1 ;hw2/hw4/hw6
ATH:004068h - WLAN/SOC_LF_TIMER2 ;hw2/hw4/hw6
ATH:004078h - WLAN/SOC_LF_TIMER3 ;hw2/hw4/hw6
ATH:004088h - WLAN/SOC_HF_TIMER ;hw2/hw4/hw6

     For LF Timer 0-3:
      0-31   TARGET
     For HF Timer:
      12-31  TARGET      ;<-- not bit0-31 for HF timer

ATH:00404Ch - WLAN/SOC_LF_TIMER_COUNT0 ;hw2/hw4/hw6
ATH:00405Ch - WLAN/SOC_LF_TIMER_COUNT1 ;hw2/hw4/hw6
ATH:00406Ch - WLAN/SOC_LF_TIMER_COUNT2 ;hw2/hw4/hw6
ATH:00407Ch - WLAN/SOC_LF_TIMER_COUNT3 ;hw2/hw4/hw6
ATH:00408Ch - WLAN/SOC_HF_TIMER_COUNT ;hw2/hw4/hw6

     For LF Timer 0-3:
      0-31   VALUE
     For HF Timer:
      12-31  VALUE       ;<-- not bit0-31 for HF timer

ATH:004090h - WLAN/SOC_HF_LF_COUNT ;hw2/hw4/hw6

      0-31   VALUE       ;<-- extra for HF timer

ATH:004050h - WLAN/SOC_LF_TIMER_CONTROL0 ;hw2/hw4/hw6
ATH:004060h - WLAN/SOC_LF_TIMER_CONTROL1 ;hw2/hw4/hw6
ATH:004070h - WLAN/SOC_LF_TIMER_CONTROL2 ;hw2/hw4/hw6
ATH:004080h - WLAN/SOC_LF_TIMER_CONTROL3 ;hw2/hw4/hw6
ATH:004094h - WLAN/SOC_HF_TIMER_CONTROL ;hw2/hw4/hw6

     For both LF and HF:
      0      RESET
      1      AUTO_RESTART
     For LF Timer 0-3:
      2      ENABLE
     For HF Timer:
      2      ON          ;<-- extra bit for HF timer
      3      ENABLE      ;<-- moved to bit3

ATH:004054h - WLAN/SOC_LF_TIMER_STATUS0 ;hw2/hw4/hw6
ATH:004064h - WLAN/SOC_LF_TIMER_STATUS1 ;hw2/hw4/hw6
ATH:004074h - WLAN/SOC_LF_TIMER_STATUS2 ;hw2/hw4/hw6
ATH:004084h - WLAN/SOC_LF_TIMER_STATUS3 ;hw2/hw4/hw6
ATH:004098h - WLAN/SOC_HF_TIMER_STATUS ;hw2/hw4/hw6

      0      INTERRUPT

     _____________________________ Real-Time Clock _____________________________

The DSi does have a battery-backed RTC accessed via Port 4000138h on ARM7 side. Below SOC_RTC would offer a second RTC, but it isn't actually used in DSi (the SOC_RTC registers aren't battery-backed, and the DSi firmware isn't initializing them from the ARM7 time either).
ATH:00409Ch - WLAN/SOC_RTC_CONTROL ;hw2/hw4/hw6

      0      LOAD_ALARM
      1      LOAD_RTC
      2      ENABLE

ATH:0040A0h - WLAN/SOC_RTC_TIME ;hw2/hw4/hw6
ATH:0040A8h - WLAN/SOC_RTC_SET_TIME ;hw2/hw4/hw6

      0-6    SECOND
      8-14   MINUTE
      16-21  HOUR
      24-26  WEEK_DAY

ATH:0040A4h - WLAN/SOC_RTC_DATE ;hw2/hw4/hw6
ATH:0040ACh - WLAN/SOC_RTC_SET_DATE ;hw2/hw4/hw6

      0-5    MONTH_DAY
      8-12   MONTH
      16-23  YEAR

ATH:0040B0h - WLAN/SOC_RTC_SET_ALARM ;hw2/hw4/hw6

      0-6    SECOND
      8-14   MINUTE
      16-21  HOUR

ATH:0040B4h - WLAN/SOC_RTC_CONFIG ;hw2/hw4/hw6

      0      DSE
      1      TWELVE_HOUR
      2      BCD

ATH:0040B8h - WLAN/SOC_RTC_ALARM_STATUS ;hw2/hw4/hw6

      0      INTERRUPT
      1      ENABLE

     _________________________________ Chip ID _________________________________

ATH:0040ECh - WLAN_CHIP_ID ;hw2/hw4 - single ID in hw2/hw4
ATH:0040ECh - LEGACY_SOC_CHIP_ID ;hw6 - first/legacy/old ID in hw6
ATH:0040F0h - SOC_CHIP_ID ;hw6 - second/actual/new ID in hw6

      0-3    VERSION_ID (4bit, usually 0 or 1)
      4-15   CONFIG_ID (12bit, usually 0)
      16-31  DEVICE_ID (16bit, usually xx00h or xx01h for AR60xx, eg. 0D00h=AR6013)

The DSi Wifi Firmware file contains a list of supported ID(s) for each chip:

      AR6002: 02010001h or 02000001h (the latter one being actually used in DSi)
      AR6013: 0D000000h or 0D000001h (unknown which one is actually used in DSi)

For 3DS:

      AR6014: returns 0D000001h=[0040ECh]

Whereas, the DSi is using that value only for verification, not for actually detecting the installed chip type (that is done by a byte in SPI FLASH).
Note: There's also a "BB_D2_CHIP_ID" register in the Baseband section.

     ___________________________________ Misc ___________________________________

ATH:0040BCh - WLAN/SOC_UART_WAKEUP ;hw2/hw4/hw6

      0      ENABLE

ATH:0040C0h - WLAN/SOC_RESET_CAUSE ;hw2/hw4/hw6

      0-2    Cause of most recent Reset event (LAST)

Possible values are (according to AR6001 datasheet - might be different in hw2/hw4/hw6):

      00h = SYS_RST_L pin was asserted
      01h = Host wrote to the SDIO reset register
      02h = Software wrote RTC_CONTROL_COLD_RST register (aka COLD_RST bit?)
      03h = Software wrote RTC_CONTROL_WARM_RST register (aka WARM_RST bit?)
      04h = Software wrote RTC_CONTROL_CPU_RST register  (aka CPU_WARM_RST bit?)
      05h = Watchdog Timer has expired
      06h..07h = Reserved

ATH:0040C4h - WLAN/SOC_SYSTEM_SLEEP ;hw2/hw4/hw6

      0      DISABLE
      1      LIGHT
      2      MAC_IF
      3      MBOX
      4      HOST_IF
      5      hw6: MCI                               ;-hw6 only

ATH:0040C8h - WLAN/SOC_SDIO_WRAPPER ;hw2/hw4/hw6

      0      ON
      1      SOC_ON
      2      WAKEUP
      3      SLEEP

ATH:004110h - WLAN/SOC_POWER_REG - located here in hw2
ATH:00410Ch - WLAN/SOC_POWER_REG - located here in hw4/hw6

      0      POWER_EN
      1      WLAN_PWD_EN
      2      hw2: WLAN_SCALE_EN             ;\
      2      hw4: WLAN_ISO_EN               ; hw2/hw4 (renamed from hw2:SCALE
      3      hw2: SOC_SCALE_EN              ; to hw4:ISO, and removed in hw6)
      3      hw4: SOC_ISO_EN                ;/
      4      RADIO_PWD_EN
      5      hw2/hw4: WLAN_ISO_CNTL         ;\hw2/hw4 (removed? in hw6)
      6      hw2/hw4: WLAN_ISO_DIS          ;/
      7      CPU_INT_ENABLE
      8-11   hw2/hw4: VLVL                  ;-hw2/hw4 (removed? in hw6)
      12     hw4/hw6: WLAN_MAC_PWD_EN       ;\
      13     hw4/hw6: WLAN_BB_PWD_EN        ; hw4/hw6
      14     hw4/hw6: DEBUG_EN              ;/
      15     hw4: SLEEP_MAKE_N_BREAK_EN     ;\hw4+hw6, but changed/renamed?
      15     hw6: DEEP_SLEEP_EN             ;/
      16     hw6: DISCON_MODE_EN            ;\hw6
      17     hw6: SWREG_VS_EN               ;/

ATH:004114h - WLAN/SOC_CORE_CLK_CTRL - located here in hw2
ATH:004110h - WLAN/SOC_CORE_CLK_CTRL - located here in hw4/hw6

      0-2    DIV

ATH:0041C0h - WLAN/SOC_GPIO_WAKEUP_CONTROL - located here in hw2
ATH:004114h - WLAN/SOC_GPIO_WAKEUP_CONTROL - located here in hw4/hw6

      0      ENABLE

ATH:004214h - SLEEP_RETENTION ;hw4/hw6

      0      ENABLE
      1      MODE
      2-9    TIME

     ___________________________________ LPO ___________________________________

ATH:0040D4h - WLAN/SOC_LPO_CAL_TIME ;hw2/hw4/hw6

      0-13   LENGTH

ATH:0040D8h - WLAN/SOC_LPO_INIT_DIVIDEND_INT ;hw2/hw4/hw6

      0-23   VALUE

ATH:0040DCh - WLAN/SOC_LPO_INIT_DIVIDEND_FRACTION ;hw2/hw4/hw6

      0-10   VALUE

ATH:0040E0h - WLAN/SOC_LPO_CAL ;hw2/hw4/hw6

      0-19   COUNT
      20     ENABLE

ATH:0040E4h - WLAN/SOC_LPO_CAL_TEST_CONTROL ;hw2/hw4/hw6

      0-4    hw2/hw4: RTC_CYCLES (5bit)     ;\hw2/hw4 (5bit)
      5      hw2/hw4: ENABLE                ;/
      0-15   hw6:     RTC_CYCLES (16bit)    ;\hw6 (expanded to 16bit)
      16     hw6:     ENABLE                ;/(and moved enable flag)

ATH:0040E8h - WLAN/SOC_LPO_CAL_TEST_STATUS ;hw2/hw4/hw6

      0-15   COUNT
      16     READY

     __________________________ below in hw4/hw6 only __________________________

ATH:004284h - LP_PERF_COUNTER ;hw4/hw6

      0      EN

ATH:004288h - LP_PERF_LIGHT_SLEEP ;hw4/hw6
ATH:00428Ch - LP_PERF_DEEP_SLEEP ;hw4/hw6
ATH:004290h - LP_PERF_ON - hw4 only

      0-31   CNT

     ___________________________________ MISC ___________________________________

ATH:0042A8h - CHIP_MODE ;hw4/hw6

      0-1    BIT

ATH:0042ACh - CLK_REQ_FALL_EDGE ;hw4/hw6

      0-7    DELAY
      31     EN

     ___________________________________ OTP ___________________________________

ATH:0042B0h - OTP ;hw4/hw6

      0      VDD12_EN
      1      LDO25_EN

ATH:0042B4h - OTP_STATUS ;hw4/hw6

      0      VDD12_EN_READY
      1      LDO25_EN_READY

     ___________________________________ PMU ___________________________________

ATH:0042B8h - PMU ;hw4/hw6

      0-1    REG_WAKEUP_TIME_SEL

ATH:0042C0h..42C4h - PMU_CONFIG[0..1] ;hw4

      0-15   VALUE ... whatever... (2x16bit)
      16-31  -

Maybe this arrary entries are equivalent/similar to the PMU_CONFIG and PMU_PAREG registers in hw6? The hw4 source code is claiming the array entries to be 16bit wide each, which doesn't match up with the two 5bit/3bit registers on hw6 though.
ATH:0042BCh - PMU_CONFIG ;hw6

      0-4    VALUE

Maybe equivalent/similar to one of the PMU_CONFIG[0..1] entries in hw4?
ATH:0042C0h - PMU_PAREG ;hw6

      0-2    LVL_CTR

Maybe equivalent/similar to one of the PMU_CONFIG[0..1] entries in hw4?
ATH:0042C8h - PMU_BYPASS ;hw4 at this address
ATH:0042C4h - PMU_BYPASS ;hw6 at this address (unlike hw4)

      0      hw4/hw6: PAREG                         ;-hw4/hw6 ;\
      1      hw4: DREG      ;-removed in hw6        ;\hw4     ; hw4/hw6 only
      2      hw4: SWREG     ;-moved to bit1 in hw6  ;/        ; (not hw2)
      1      hw6: SWREG     ;-formerly in bit2      ;-hw6     ;/

     ________________________________ THERM CTRL ________________________________

ATH:0042DCh - THERM_CTRL1 ;hw4/hw6

      0      INT_STATUS
      1      INT_EN
      2      MEASURE
      3-4    TYPE
      5-11   WIDTH
      12-15  WIDTH_ARBITOR
      16     BYPASS

ATH:0042E0h - THERM_CTRL2 ;hw4/hw6

      0-7    LOW
      8-15   HIGH
      16-23  SAMPLE
      24     ADC_ON
      25     ADC_OFF

ATH:0042E4h - THERM_CTRL3 ;hw4/hw6

      0-7    ADC_OFFSET
      8-16   ADC_GAIN

     ____________________________ below in hw6 only ____________________________

ATH:0042E8h - LISTEN_MODE1 ;hw6

      0      ENABLE
      1      CLOCK_GATE
      2      TIMER_OVERFLOW_WAKE
      3-18   TIMER_THRESH_WAKE
      19     TIMER_CLEAR

ATH:0042ECh - LISTEN_MODE2 ;hw6

      0-15   TIMER_TRIGGER_WAKE

ATH:0042F0h - AUDIO_PLL_CONFIG ;hw6

      0-3    REFDIV
      4      BYPASS
      5      PLLPWD
      7-9    POSTPLLDIV
      12-14  EXT_DIV
      31     UPDATING

ATH:0042F4h - AUDIO_PLL_MODULATION ;hw6

      0      START
      1-6    TGT_DIV_INT
      11-28  TGT_DIV_FRAC

ATH:0042F8h - AUDIO_PLL_MOD_STEP ;hw6

      0-3    UPDATE_CNT
      4-13   INT
      14-31  FRAC

ATH:0042FCh - CURRENT_AUDIO_PLL_MODULATION ;hw6

      1-6    INT
      10-27  FRAC

ATH:004300h - ETH_PLL_CONFIG ;hw6

      0-4    REFDIV
      5      BYPASS
      6      PLLPWD
      7-9    OUTDIV
      12-17  INT
      18-27  FRAC
      28     RANGE
      29     GE0
      30     GE0_MASTER

ATH:004304h - CPU_PLL_CONFIG ;hw6

      0-4    REFDIV
      6      PLLPWD
      7-9    OUTDIV
      12-17  INT
      20-25  FRAC
      28     RANGE

ATH:004308h - BB_PLL_CONFIG ;hw6

      0-17   FRAC

ATH:00430Ch - ETH_XMII ;hw6

      0-7    PHASE0_COUNT
      8-15   PHASE1_COUNT
      16-23  OFFSET_COUNT
      24     OFFSET_PHASE
      25     GIGE
      26-27  TX_DELAY
      28-29  RX_DELAY
      30     GIGE_QUAD
      31     TX_INVERT

ATH:004310h - USB_PHY_CONFIG ;hw6

      0      HOSTMODE
      1      PLL_PWD
      2      TESTMODE
      3      REFDIV
      4-7    REFCLK_SEL

ATH:004314h - MITSUMI_INT_CONTROL_REG ;Mitsumi Interrupt Enable ;hw6
ATH:004318h - MITSUMI_INT_STATUS_REG ;Mitsumi Interrupt Status ;hw6

      0      MODE_SWITCH
      1      RF_SLEEP
      2      BBP_SLEEP
      3      FLIGHT_MODE

Maybe this is related to the Nintendo DSi's backwards compatibilty mode (in which, the Atheros chip is simulating a Mitsumi BB/RF chip for use with older NDS games)? Or maybe it's unrelated to that (DSi/3DS don't seem to have hw6 at all).
ATH:00431Ch - CURRENT_WORKING_MODE ;hw6

      0      VALUE
      1      NOT_FIRST_MIT_MODE
      2      MIT_REG_WR_TRIGGER_EN
      5      MIT_FORCE_ACTIVE_ON

ATH:004320h - RTC_SLEEP_COUNT ;hw6

      0-5    THRESHOLD

ATH:004324h - MIT2_VAP ;hw6

      0      MODE

ATH:004328h - SECOND_HOST_INFT ;hw6

      0      SDIO_MODE

ATH:00432Ch - SDIO_HOST ;hw6

      0      RESET

ATH:004330h - ENTERPRISE_CONFIG ;hw6

      0      LOCATION_DISABLE
      1      LOOPBACK_DISABLE
      2      MIN_PKT_SIZE_DISABLE
      3      TXBF_DISABLE
      4      CH_10MHZ_DISABLE
      5      CH_5MHZ_DISABLE
      6      CHAIN1_DISABLE
      7      DUAL_BAND_DISABLE
      8      GREEN_TX_DISABLE
      9      LDPC_DISABLE
      10     STBC_DISABLE
      11     SWCOM_IDLE_MODE
      12     TPC_LOWER_PERFORMANCE

ATH:004334h - RTC_DEBUG_BUS ;hw6

      0      SEL

ATH:004338h - RTC_EXT_CLK_BUF ;hw6

      0      EN

DSi Atheros Wifi - Internal I/O - 00x000h - RTC/Clock WLAN (hw2/hw4/hw6)

ATH:004004h/004004h/005004h - WLAN_XTAL_CONTROL ;hw2/hw4/hw6

      0      TCXO

ATH:004010h/004010h/005010h - WLAN_QUADRATURE ;hw2/hw4/hw6

      0-1    hw2/hw4: DAC (2bit)   ;\expanded DAC from 2bit (hw2/hw4) to 3bit (hw6)
      0-2    hw6:     DAC (3bit)   ; (and removed SEL bit in hw6)
      2      hw2/hw4: SEL          ;/
      4-5    hw2:     ADC (2bit)   ;\expanded ADC from 2bit (hw2) to 4bit (hw4)
      4-7    hw4/hw6: ADC (4bit)   ;/

ATH:004014h/004014h/005014h - WLAN_PLL_CONTROL ;hw2/hw4/hw6

      0-9    DIV
      12-15  hw2/hw4: REFDIV (4bit)
      10-13  hw6:     REFDIV (4bit, now here)
      14-15  hw6:     CLK_SEL ;<-- maybe replaces removed "SEL" in WLAN_QUADRATURE?
      16     BYPASS
      17     UPDATING                       (R)
      18     NOPWD
      19     MAC_OVERRIDE
      20     DIG_TEST_CLK

ATH:004018h/004018h/005018h - WLAN_PLL_SETTLE ;hw2/hw4/hw6

      0-11   hw2/hw4: TIME (12bit)          ;\decreased from 12bit to 11bit in hw6
      0-10   hw6:     TIME (11bit)          ;/

ATH:00401Ch/00401Ch/00501Ch - WLAN_XTAL_SETTLE ;hw2/hw4/hw6

      0-7    hw2/hw4: TIME (8bit)           ;\decreased from 8bit to 7bit in hw6
      0-6    hw6:     TIME (7bit)           ;/

ATH:004020h/004020h/005020h - WLAN_CLOCK_OUT ;hw2/hw4/hw6

      0-3    hw2/hw4: SELECT (4bit)         ;\raised from 4bit to 5bit in hw6,
      0-4    hw6:     SELECT (5bit)         ; and added new DELAY field in hw6
      5-7    hw6:     DELAY (3bit, new)     ;/

ATH:00402Ch/00402Ch/005024h - WLAN_BIAS_OVERRIDE ;hw2/hw4/hw6

      0      ON

ATH:0040CCh/0040CCh/005030h - WLAN_MAC_SLEEP_CONTROL ;hw2/hw4/hw6

      0-1    hw2/hw4: ENABLE                ;\
      0      hw6:     ENABLE                ; reduced from 2bit to 1bit in hw6
      1      hw6:     RESERVED              ;/
      2      hw6:     HSEL_WMAC_ENABLE      ;-new in hw6

ATH:0040D0h/0040D0h/005034h - WLAN_KEEP_AWAKE ;hw2/hw4/hw6

      0-7    COUNT

ATH:0040F0h/0040F0h/005038h - WLAN_DERIVED_RTC_CLK ;hw2/hw4/hw6

      1-15   PERIOD
      16-17  hw2/hw4: FORCE                 ;-hw2/hw4 only (removed in hw6)
      18     EXTERNAL_DETECT            (R)
      20     EXTERNAL_DETECT_EN

     ________________________ SLP or SLOP or SLEEP or so ________________________

ATH:0040F4h/0040F4h/00503Ch - MAC_PCU_SLP32_MODE ;hw2/hw4/hw6
ATH:028244h (mirror of 0040F4h) - MAC_PCU_REG_SLP32_MODE (ini:10F424h) ;hw2

      0-19   HALF_CLK_LATENCY
      20     ENABLE    ;<-- see hw2 note    ;-hw2/hw4/hw6 (on hw2 in mirror only)
      21     hw2:     TSF_WRITE_PENDING     ;\changed/renamed in hw2/hw4
      21     hw4/hw6: TSF_WRITE_STATUS  (R) ;/
      22     hw4/hw6: DISABLE_32KHZ         ;\
      23     hw4/hw6: FORCE_BIAS_BLOCK_ON   ; hw4/hw6 only (unspecified in hw2)
      24     hw4/hw6: TSF2_WRITE_STATUS (R) ;/

In hw2, this register appears to be mirrored to 0040F4h (without ENABLE flag in bit20) and 028244h (bit ENABLED flag in bit20).
ATH:0040F8h/0040F8h/005040h - MAC_PCU_SLP32_WAKE ;hw2/hw4/hw6
ATH:028248h (mirror of 0040F8h) - MAC_PCU_REG_SLP32_WAKE (ini:07EFh) ;hw2

      0-15   XTL_TIME

ATH:0040FCh/0040FCh/005044h - MAC_PCU_SLP32_INC ;hw2/hw4/hw6
ATH:02824Ch (mirror of 0040FCh) - MAC_PCU_REG_SLP32_TSF_INC (ini:1E848h) ;hw2

      0-19   TSF_INC

ATH:004100h/004100h/005048h - MAC_PCU_SLP_MIB1 ;hw2/hw4/hw6
ATH:028250h (mirror of 004100h) - MAC_PCU_REG_SLPMIB1 ;hw2

      0-31   SLEEP_CNT

ATH:004104h/004104h/00504Ch - MAC_PCU_SLP_MIB2 ;hw2/hw4/hw6
ATH:028254h (mirror of 004104h) - MAC_PCU_REG_SLPMIB2 ;hw2

      0-31   CYCLE_CNT

ATH:004108h/004108h/005050h - MAC_PCU_SLP_MIB3 ;hw2/hw4/hw6
ATH:028258h (mirror of 004108h) - MAC_PCU_REG_SLPMIB3 ;hw2

      0      CLR_CNT
      1      PENDING                    (R)

In hw2, this register appears to be mirrored to 004108h (with bit1 called "PENDING") and 028258h (with bit1 called "PEND" for whatever reason).
ATH:0280D4h/004204h/0050C0h - MAC_PCU_SLP1 ;hw2/hw4/hw6

      0-18   hw2: outcommented: NEXT_DTIM)   (hw2: ini:2AAAAh) ;\outcommented
      20     hw2: outcommented: ENH_SLEEP_ENABLE) (hw2: ini:1) ;/
      0-4    hw2/hw6: CAB_TIMEOUT_EXT             (hw2: ini:0) ;-hw2/hw6
      0-15   hw4: CAB_TIMEOUT                                  ;-hw4
      19     ASSUME_DTIM                          (hw2: ini:0) ;-hw2/hw4/hw6
      20     hw6: BUG_59985_FIX_ENABLE                         ;-hw6
      21-31  hw2/hw6: CAB_TIMEOUT                 (hw2: ini:5) ;-hw2/hw6

ATH:0280D8h/004208h/0050C4h - MAC_PCU_SLP2 ;hw2/hw4/hw6

      0-18   hw2: outcommented: NEXT_TIM  (hw2: ini:55555h) ;-outcommented
      0-15   hw4: BEACON_TIMEOUT                            ;-hw4
      0-4    hw2/hw6: BEACON_TIMEOUT_EXT  (hw2: ini:0)      ;\hw2/hw6
      21-31  hw2/hw6: BEACON_TIMEOUT      (hw2: ini:2)      ;/

ATH:0280DCh - (outcommented) ;aka MAC_PCU_REG_SLP3 ;hw2 (but outcommented)

      0-15   hw2: outcommented: TIM_PERIOD  (hw2: ini:2)    ;\outcommented
      16-31  hw2: outcommented: DTIM_PERIOD (hw2: ini:3)    ;/

ATH:028260h/0050C8h - MAC_PCU_SLP3 ;hw2/hw6

      0-15   hw2/hw6: CAB_AWAKE_DUR        (hw2: ini:0005h) ;\hw2/hw6
      16     hw2/hw6: CAB_AWAKE_ENABLE     (hw2: ini:0)     ;/

ATH:0050CCh - MAC_PCU_SLP4 ;hw6

      0-15   hw6: BEACON2_TIMEOUT
      16-30  hw6: CAB2_TIMEOUT
      31     hw6: ASSUME_DTIM2

     ______________________________ Generic Timers ______________________________

ATH:028200h..02821Ch - MAC_PCU_REG_GNRCTMR_N[0..7] ;hw2
ATH:028220h..02823Ch - MAC_PCU_REG_GNRCTMR_P[0..7] ;hw2
ATH:004140h..417Ch/005064h..50A0h - MAC_PCU_GENERIC_TIMERS[0..15] ;hw4/hw6
ATH:0041C0h..41FCh/0050DCh..5118h - MAC_PCU_GENERIC_TIMERS2[0..15] ;hw4/hw6

      0-31   hw2, for "GNRCTMR_N" entries: GNRCTMR_N (32bit)
      0-27   hw2, for "GNRCTMR_P" entries: GNRCTMR_P (only 28bit here)
      0-31   hw4/hw6: DATA (32bit)

Unknown how that stuff is related...

      - hw2   has "8xTMR_N"  plus "8xTMR_P"
      - hw4/6 has "16xTIMER" plus "16xTIMER2"

maybe TIMER and TIMER2 are equivalent to TMR_N and TMR_P, or maybe TIMER is meant to contain "eight N+P pairs" (and TIMER2 another eight pairs), or maybe the "N" and "P" stuff was completely dropped in hw4/hw6. The ENABLE bits are also weird:

      - hw2 has 1x8 ENABLE bits  (for 8+8 timer entries)
      - hw4 has 2x16 ENABLE bits (for 16+16 timer entries)
      - hw6 has 2x8 ENABLE bits  (for 16+16 timer entries, too)

Note that hw2 has the generic timers in the WMAC PCU area at 028xxxh.
ATH:028240h/004180h/0050BCh - MAC_PCU_GENERIC_TIMERS_MODE ;hw2/hw4/hw6

      0-15   hw4: ENABLE         (16bit)            ;\hw4 (the other bits are
      16-31  hw4: -                                 ;/moved to "MODE3" in hw4)
      0-7    hw6: ENABLE         (8bit)             ;\
      8-10   hw6: OVERFLOW_INDEX (3bit)        (R)  ; hw2/hw6
      11     hw6: -                                 ;
      12-31  hw6: THRESH         (20bit)            ;/

ATH:004200h/005134h - MAC_PCU_GENERIC_TIMERS_MODE2 ;hw4/hw6 (not hw2)

      0-15   hw4: ENABLE          (16bit)           ;-hw4
      0-7    hw6: ENABLE          (8bit)            ;\
      8-11   hw6: OVERFLOW_INDEX  (4bit)        (R) ; hw6
      12-15  hw6: OVERFLOW_INDEX2 (4bit)        (R) ;/

ATH:0042D4h - MAC_PCU_GENERIC_TIMERS_MODE3 ;hw4 only

      0-19   hw4: THRESH                    ;\hw4 only (in hw2/hw6 this stuff is
      24-27  hw4: OVERFLOW_INDEX            ;/located in "MODE" instead of "MODE3")

ATH:005150h - MAC_PCU_GENERIC_TIMERS_TSF_SEL ;hw6 only

      0-15   VALUE

     __________________________ below in hw4/hw6 only __________________________

ATH:004118h/005148h - WLAN_HT (aka HT) ;hw4/hw6

      0      MODE

ATH:00411Ch/005054h - MAC_PCU_TSF_L32 ;hw4/hw6 (hw2: see REG_TSF_L32)
ATH:004120h/005058h - MAC_PCU_TSF_U32 ;hw4/hw6

      0-63   VALUE

ATH:0042CCh/0050D4h - MAC_PCU_TSF2_L32 ;hw4/hw6
ATH:0042D0h/0050D8h - MAC_PCU_TSF2_U32 ;hw4/hw6

      0-63   VALUE

ATH:00505Ch - MAC_PCU_WBTIMER_0 ;hw6

      0      ENABLE                                 ;-hw6 only

ATH:004124h/005060h - MAC_PCU_WBTIMER_1 (aka MAC_PCU_WBTIMER) ;hw4/hw6

      0-31   VALUE

ATH:00420Ch/0050D0h - MAC_PCU_RESET_TSF ;hw4/hw6

      24     ONE_SHOT    ;aka "one shot RESET_TSF"   ;<-- see "REG_BEACON" in hw2
      25     ONE_SHOT2

ATH:00427Ch/005154h - MAC_PCU_BMISS_TIMEOUT ;hw4/hw6
ATH:005158h - MAC_PCU_BMISS2_TIMEOUT ;hw6 only

      0-23   VALUE  (aka BMISS_TIMEOUT)
      24     ENABLE (aka BMISS_TIMEOUT_ENABLE)

     ____________________________ below in hw2 only ____________________________

ATH:00410Ch - MAC_PCU_SLP_BEACON - hw2 only (removed or renamed in hw4)
ATH:028264h (mirror of 00410Ch) - MAC_PCU_REG_SLP5 (ini: 0FFFFFFh) ;hw2

      0-23   hw2: BMISS_TIMEOUT                  ;\hw2 only
      24     hw2: BMISS_TIMEOUT_ENABLE           ;/

See also: - MAC_PCU_BMISS_TIMEOUT <--- is that equivalent on hw4/hw6!?!
ATH:004120h..413Ch - SDIO_SETUP_CIRCUIT[8] - hw2 only (removed in hw4/hw6)
ATH:004160h..417Ch - CPU_SETUP_CIRCUIT[8] - hw2 only (removed in hw4/hw6)
ATH:0041A0h..41BCh - BB_SETUP_CIRCUIT[8] - hw2 only (removed in hw4/hw6)

      0-7    hw2: VECTOR

ATH:004140h - SDIO_SETUP_CONFIG - hw2 only (removed in hw4/hw6)
ATH:004144h - CPU_SETUP_CONFIG - hw2 only (removed in hw4/hw6)
ATH:004180h - BB_SETUP_CONFIG - hw2 only (removed in hw4/hw6)

      0      hw2: CLEAR
      1      hw2: ENABLE

     ____________________________ below in hw4 only ____________________________

ATH:004210h - MAC_PCU_TSF_ADD_PLL ;hw4

      0-7    hw4: VALUE

ATH:004280h - MAC_PCU_CAB_AWAKE ;hw4

      0-15   hw4: DURATION
      16     hw4: ENABLE

ATH:0042D8h - MAC_PCU_DIRECT_CONNECT ;hw4

      0      hw4: AP_STA_ENABLE
      1      hw4: AP_TSF_1_2_SEL
      2      hw4: STA_TSF_1_2_SEL

ATH:004218h..004278h - Bluetooth Coex related ;hw4
ATH:004294h..0042A4h - Bluetooth Coex related, too? ;hw4
These hw4 ports have been moved to 007xxxh in hw6. See Bluetooth Coex chapter for details.

     ____________________________ below in hw6 only ____________________________

ATH:005000h - WLAN_RESET_CONTROL ;hw6

      0      MAC_WARM_RST           ;-moved from 004000h.bit4   ;\
      1      MAC_COLD_RST           ;-moved from 004000h.bit5   ;
      2      WARM_RST               ;-moved from 004000h.bit7   ;
      3      COLD_RST               ;-also in 004000h.bit8      ;
      4      BB_WARM_RST            ;-moved from 004000h.bit12  ;
      5      BB_COLD_RST            ;-moved from 004000h.bit13  ;/
      6      RADIO_SRESET           ;-new hw6 bit               ;\
      7      MCI_RESET              ;-new hw6 bit               ;/

ATH:005008h - WLAN_REG_CONTROL0 ;hw6

      0-31   SWREG_BITS

ATH:00500Ch - WLAN_REG_CONTROL1 ;hw6

      0      SWREG_PROGRAM
      1-2    OTPREG_LVL

ATH:005028h - WLAN_RESET_CAUSE ;hw6 ;<--- mirror of SOC_RESET_CAUSE?

      0-2    LAST                           (R)

ATH:00502Ch - WLAN_SYSTEM_SLEEP ;hw6 ;<--partial mirror of SOC_SYSTEM_SLEEP?

      0      DISABLE
      1      LIGHT
      2      MAC_IF                         (R)

ATH:00515Ch - RTC_AXI_AHB_BRIDGE ;hw6 only

      0-1    hw6: MAX_BEATS

ATH:005160h - UNIFIED_MAC_REVID (R) ;hw6 only

      0-31   hw6: VALUE                          (R)

DSi Atheros Wifi - Internal I/O - 0xx240h - RTC/Clock SYNC (hw6)

ATH:xxx240h - RTC_SYNC_RESET

      0      RESET_L

ATH:xxx244h - RTC_SYNC_STATUS

      0      SHUTDOWN_STATE                 (R)
      1      ON_STATE                       (R)
      2      SLEEP_STATE                    (R)
      3      WAKEUP_STATE                   (R)
      4      WRESET                         (R)
      5      PLL_CHANGING                   (R)

ATH:xxx248h - RTC_SYNC_DERIVED

      0      BYPASS
      1      FORCE
      2      FORCE_SWREG_PWD                (W)
      3      FORCE_LPO_PWD                  (W)

ATH:xxx24Ch - RTC_SYNC_FORCE_WAKE

      0      ENABLE                         (R)
      1      INTR

ATH:xxx250h - RTC_SYNC_INTR_CAUSE

      0      SHUTDOWN_STATE
      1      ON_STATE
      2      SLEEP_STATE
      3      WAKEUP_STATE
      4      SLEEP_ACCESS
      5      PLL_CHANGING

ATH:xxx254h - RTC_SYNC_INTR_ENABLE

      0      SHUTDOWN_STATE
      1      ON_STATE
      2      SLEEP_STATE
      3      WAKEUP_STATE
      4      SLEEP_ACCESS
      5      PLL_CHANGING

ATH:xxx258h - RTC_SYNC_INTR_MASK

      0      SHUTDOWN_STATE
      1      ON_STATE
      2      SLEEP_STATE
      3      WAKEUP_STATE
      4      SLEEP_ACCESS
      5      PLL_CHANGING

DSi Atheros Wifi - Internal I/O - 006000h - WLAN Coex (MCI) (hw6)

ATH:006000h - MCI_COMMAND0 ;hw6

      0-7    HEADER
      8-12   LEN
      13     DISABLE_TIMESTAMP

ATH:006004h - MCI_COMMAND1 ;hw6

      0-31   ADDR

ATH:006008h - MCI_COMMAND2 ;hw6

      0      RESET_TX
      1      RESET_RX
      2-9    RESET_RX_NUM_CYCLES

ATH:00600Ch - MCI_RX_CTRL ;hw6

      0      DISABLE_TIMESTAMP
      1      DISABLE_MAXGAIN_RESET
      2      DISABLE_MAXGAIN_WBTIMER_RESET

ATH:006010h - MCI_TX_CTRL ;hw6

      0-1    CLK_DIV
      2      DISABLE_LNA_UPDATES
      3-23   GAIN_UPDATE_FREQ
      24-27  GAIN_UPDATE_NUM

ATH:006014h - MCI_MSG_ATTRIBUTES_TABLE ;hw6

      0-15   CHECKSUM_EN
      16-31  INVALID_HDR

ATH:006018h - MCI_SCHD_TABLE_0 ;hw6

      0-31   BASE_ADDR

ATH:00601Ch - MCI_SCHD_TABLE_1 ;hw6

      0-15   OWN
      16-31  SW_REQ_OWN

ATH:006020h - MCI_GPM_0 ;hw6

      0-31   START_ADDR

ATH:006024h - MCI_GPM_1 ;hw6

      0-15   LEN
      16-31  WRITE_PTR                      (R)

ATH:006028h - MCI_INTERRUPT_RAW ;Interrupt Flags ;hw6
ATH:00602Ch - MCI_INTERRUPT_EN ;Interrupt Enable ;hw6

      0      SW_MSG_DONE
      1      CPU_INT_MSG
      2      RX_CKSUM_FAIL
      3      RX_INVALID_HDR
      4      RX_HW_MSG_FAIL
      5      RX_SW_MSG_FAIL
      7      TX_HW_MSG_FAIL
      8      TX_SW_MSG_FAIL
      9      RX_MSG
      10     REMOTE_SLEEP_UPDATE
      11-26  BT_PRI
      27     BT_PRI_THRESH
      28     BT_FREQ
      29     BT_STOMP

ATH:006030h - MCI_REMOTE_CPU_INT ;Flags ;hw6
ATH:006034h - MCI_REMOTE_CPU_INT_EN ;Enable ;hw6

      0-31   BODY

ATH:006038h - MCI_INTERRUPT_RX_MSG_RAW ;Flags ;hw6
ATH:00603Ch - MCI_INTERRUPT_RX_MSG_EN ;Enable ;hw6

      0      REMOTE_RESET
      1      LNA_CTRL
      2      CONT_NACK
      3      CONT_INFO
      4      CONT_RST
      5      SCHD_INFO
      6      CPU_INT
      8      GPM
      9      LNA_INFO
      10     SYS_SLEEPING
      11     SYS_WAKING
      12     REQ_WAKE

ATH:006040h - MCI_CPU_INT ;hw6

      0-31   MSG

ATH:006044h - MCI_RX_STATUS ;hw6

      8-11   SCHD_MSG_INDEX                 (R)
      12     REMOTE_SLEEP                   (R)

ATH:006048h - MCI_CONT_STATUS ;hw6

      0-7    RSSI_POWER                     (R)
      8-15   PRIORITY                       (R)
      16     TX                             (R)
      17-20  LINKID                         (R)
      21-27  CHANNEL                        (R)
      28-31  OWNER                          (R)

ATH:00604Ch - MCI_BT_PRI0 ;hw6
ATH:006050h - MCI_BT_PRI1 ;hw6
ATH:006054h - MCI_BT_PRI2 ;hw6
ATH:006058h - MCI_BT_PRI3 ;hw6

      0-7    VAL0
      8-15   VAL1
      16-23  VAL2
      24-31  VAL3

ATH:00605Ch - MCI_BT_PRI ;hw6

      0-7    THRESH

ATH:006060h - MCI_WL_FREQ0 ;hw6

      0-31   MASK

ATH:006064h - MCI_WL_FREQ1 ;hw6

      0-31   MASK

ATH:006068h - MCI_WL_FREQ2 ;hw6

      0-15   MASK

ATH:00606Ch - MCI_GAIN ;hw6

      0-7    OFFSET1
      8-15   OFFSET2

ATH:006070h - MCI_WBTIMER1 ;hw6
ATH:006074h - MCI_WBTIMER2 ;hw6
ATH:006078h - MCI_WBTIMER3 ;hw6
ATH:00607Ch - MCI_WBTIMER4 ;hw6

      0-31   TARGET

ATH:006080h - MCI_MAXGAIN ;hw6

      0-7    GAIN1
      8-15   GAIN2
      16-23  GAIN3
      24-31  GAIN4

ATH:0060ACh - BTCOEX_CTRL ;hw6

      2      MCI_MODE_ENABLE

ATH:00614Ch - BTCOEX_CTRL2 ;hw6

      0-7    RESERVED2
      8-10   OBS_SEL

ATH:006254h - BTCOEX_DBG ;hw6

      0-31   OBS                            (R)

ATH:006258h - MCI_LAST_HW_MSG_HDR ;hw6

      0-7    HDR                            (R)
      8-10   LEN                            (R)

ATH:00625Ch - MCI_LAST_HW_MSG_BDY ;hw6

      0-31   BDY                            (R)

ATH:006260h - MCI_MAXGAIN_RST ;hw6

      0-31   TARGET

DSi Atheros Wifi - Internal I/O - 00x000h - Bluetooth Coex (hw4/hw6)

ATH:004218h/007000h - BTCOEXCTRL - hw4/hw6

      0-7    GAP
      8      CLK_CNT_EN
      9      FRAME_CNT_EN
      10     IDLE_CNT_EN
      11     SYNC_DET_EN
      12-17  PRIORITY_TIME
      18-22  FREQ_TIME
      23-24  PTA_MODE
      25     WBSYNC_ON_BEACON
      26     hw4: WBTIMER_ENABLE            ;hw4 only
      27     unspecified
      28     hw6: RFGAIN_VALID_SRC          ;hw6 only

ATH:004228h/007010h - BTCOEX0 ;SYNC_DUR - hw4/hw6

      0-7    SYNC_DUR

ATH:00422Ch/007014h - BTCOEX1 ;CLK_THRES - hw4/hw6

      0-20   CLK_THRES

ATH:004230h/007018h - BTCOEX2 ;FRAME_THRES - hw4/hw6

      0-7    FRAME_THRES

ATH:004234h/00701Ch - BTCOEX3 ;CLK_CNT - hw4/hw6

      0-20   CLK_CNT

ATH:004238h/007020h - BTCOEX4 ;FRAME_CNT - hw4/hw6

      0-7    FRAME_CNT

ATH:00423Ch/007024h - BTCOEX5 ;IDLE_CNT - hw4/hw6

      0-15   IDLE_CNT

ATH:004240h/007028h - BTCOEX6 ;IDLE_RESET_LVL_BITMAP - hw4/hw6

      0-31   IDLE_RESET_LVL_BITMAP

ATH:004244h/00702Ch - LOCK - hw4/hw6

      0-7    TUNLOCK_MASTER
      8-15   TLOCK_MASTER
      16-23  TUNLOCK_SLAVE
      24-31  TLOCK_SLAVE

ATH:00421Ch/007004h - WBSYNC_PRIORITY1 - hw4/hw6
ATH:004220h/007008h - WBSYNC_PRIORITY2 - hw4/hw6
ATH:004224h/00700Ch - WBSYNC_PRIORITY3 - hw4/hw6
ATH:004248h/007030h - NOLOCK_PRIORITY - hw4/hw6

      0-31   BITMAP

ATH:00424Ch/007034h - WBSYNC - hw4/hw6
ATH:004250h/007038h - WBSYNC1 - hw4/hw6
ATH:004254h/00703Ch - WBSYNC2 - hw4/hw6
ATH:004258h/007040h - WBSYNC3 - hw4/hw6

      0-31   BTCLOCK                        (R) (read-only, according to hw6)

ATH:00425Ch/007044h - WB_TIMER_TARGET - hw4/hw6

      0-31   VALUE

ATH:004260h/007048h - WB_TIMER_SLOP - hw4/hw6

      0-9    VALUE

ATH:004264h/00704Ch - BTCOEX_INT_EN - hw4/hw6
ATH:004268h/007050h - BTCOEX_INT_STAT - hw4/hw6

      0      CLK_CNT
      1      FRAME_CNT
      2      END
      3      SYNC
      4      NOSYNC
      5      BTPRIORITY       ;<-- for INT_STAT (but, N/A for INT_EN)       (R)
      6      BTPRIORITY_STOMP ;<-- for INT_STAT (but, N/A for INT_EN)       (R)
      7      WB_TIMER
      8      I2C_MESG_RECV    ;<-- for INT_STAT  (but, "ST_MESG_RECV" for INT_EN?)
      9      I2C_MESG_SENT
      10     I2C_TX_FAILED
      11     I2C_RECV_OVERFLOW

ATH:00426Ch/007054h - BTPRIORITY_INT_EN - hw4/hw6
ATH:004270h/007058h - BTPRIORITY_INT_STAT - hw4/hw6

      0-31   BITMAP

ATH:004274h/00705Ch - BTPRIORITY_STOMP_INT_EN - hw4/hw6
ATH:004278h/007060h - BTPRIORITY_STOMP_INT_STAT - hw4/hw6

      0-31   BITMAP

ATH:004294h/007064h - ST_64_BIT - hw4/hw6

      0      MODE
      1-5    SOC_CLK_DIVIDE_RATIO
      6      CLOCK_GATE
      7      DRIVE_MODE
      8      REQ_ACK_NOT_PULLED_DOWN
      9-26   TIMEOUT

ATH:004298h/007068h - MESSAGE_WR - hw4/hw6
ATH:0042A0h/007070h - MESSAGE_RD - hw4/hw6

      0-31   TYPE

ATH:00429Ch/00706Ch - MESSAGE_WR_P - hw4/hw6
ATH:0042A4h/007074h - MESSAGE_RD_P - hw4/hw6

      0-31   PARAMETER

     _________ below hw6 only _________

ATH:007078h - BTPRIORITY_INT - hw6 only

      0-7    DELAY

ATH:00707Ch - SCO_PARAMS - hw6 only

      0-13   PERIOD
      14-23  SLOP

ATH:007080h - SCO_PRIORITY - hw6 only

      0-31   BITMAP

ATH:007084h - SCO_SYNC - hw6 only

      0-31   BTCLOCK

ATH:007088h - BTCOEX_RAW_STAT - hw6 only

      0      CLK_CNT
      1      FRAME_CNT
      2      END
      3      SYNC
      4      NOSYNC
      7      WB_TIMER

ATH:00708Ch - BTPRIORITY_RAW_STAT - hw6 only

      0-31   BITMAP

ATH:007090h - BTPRIORITY_STOMP_RAW_STAT - hw6 only

      0-31   BITMAP

DSi Atheros Wifi - Internal I/O - 00x000h - Memory Control (hw2/hw4/hw6)

TCAM/BCAM (Ternary/Binary Content Addressable Memory) (ROM Patches)
TCAM/BCAM registers are allowing to patch ROM (in a similar fashion as Game Genie cheat devices). The ROM patches can be initialized via BMI commands:
DSi Atheros Wifi - BMI Bootloader Commands
Many ROM functions are called via a Table in RAM, which can be patched without needing the TCAM/BCAM feature (actually, the DSi's AR6002 firmware is patching only three of that RAM Table entries, and leaves the TCAM feature completely unused).

     ______________________ hw2 ROM Patches (TCAM) ______________________

ATH:008000h..807Ch - (WLAN_)MC_TCAM_VALID[0..31] ;hw2

      0      BIT    (?=Patch Enable)

ATH:008080h..80FCh - (WLAN_)MC_TCAM_MASK[0..31] ;hw2

      0-2    SIZE   (... patch area, selectable 32-bytes or bigger or so?)

The eight size settings are probably 20h,40h,80h,100h,200h,400h,800h,1000h.
ATH:008100h..817Ch - (WLAN_)MC_TCAM_COMPARE[0..31] ;hw2

      5-21   KEY    (Patch ROM Address in 32-byte steps) (probably 0E0000h and up?)

ATH:008180h..81FCh - (WLAN_)MC_TCAM_TARGET[0..31] ;hw2

      5-21   ADDR   (Patch RAM Address in 32-byte steps) (probably 100000h and up?)

     ______________________ hw4 ROM Patches (BCAM) ______________________

The hw4 ROM patching is done in 32bit Data units, but 16bit/24bit Xtensa opcodes aren't neccessarily 32bit aligned, so one may need 1-2 patch slots per opcode.
ATH:008000h..0081FCh - WLAN_MC_BCAM_VALID[0..127] ;hw4

      0      BIT    some "bit" (128 x 1bit)    (?=Patch Enable)
      1-31   -

ATH:008200h..0083FCh - WLAN_MC_BCAM_COMPARE[0..127] ;hw4

      0-1    -
      2-19   KEY    some "key" (128 x 18bit)   (Patch Address in 4-byte steps)
      20-31  -

ATH:008400h..0085FCh - WLAN_MC_BCAM_TARGET[0..127] ;hw4

      0-31   INST   some "inst" (128 x 32bit)  (Patch Data)

ATH:008610h - WLAN_BCAM_CONFLICT_ERROR ;hw4

      0      DPORT_FLAG
      1      IPORT_FLAG
      2-31   -

     _______________________ hw6 ROM Patches (?) _______________________

Unknown if or how ROM Patches are supported on hw6 (the hw6 source code doesn't define any TCAM/BCAM registers).

     ______________________ ADDR_ERROR Registers ______________________

ATH:008200h - (WLAN_)ADDR_ERROR_CONTROL ;hw2
ATH:008600h - WLAN_APB_ADDR_ERROR_CONTROL ;hw4
ATH:010018h - WLAN_APB_ADDR_ERROR_CONTROL ;hw6

      0      ENABLE
      1      QUAL_ENABLE
      2-31   -

ATH:008204h - (WLAN_)ADDR_ERROR_STATUS ;hw2
ATH:008604h - WLAN_APB_ADDR_ERROR_STATUS ;hw4
ATH:01001Ch - WLAN_APB_ADDR_ERROR_STATUS ;hw6

      0-24   ADDRESS
      25     WRITE
      26-31  -

ATH:008608h - WLAN_AHB_ADDR_ERROR_CONTROL ;hw4
ATH:010020h - WLAN_AHB_ADDR_ERROR_CONTROL ;hw6

      0      ENABLE
      1-31   -

ATH:00860Ch - WLAN_AHB_ADDR_ERROR_STATUS ;hw4
ATH:010024h - WLAN_AHB_ADDR_ERROR_STATUS ;hw6

      0-23   ADDRESS
      24-29  -
      30     MBOX
      31     MAC

     ______________________ hw4 MISC Registers ______________________

ATH:008614h - WLAN_CPU_PERF_CNT ;hw4

      0      EN
      1-31   -

ATH:008618h - WLAN_CPU_INST_FETCH ;hw4
ATH:00861Ch - WLAN_CPU_DATA_FETCH ;hw4

      0-31   CNT

ATH:008620h - WLAN_CPU_RAM1_CONFLICT ;hw4
ATH:008624h - WLAN_CPU_RAM2_CONFLICT ;hw4
ATH:008628h - WLAN_CPU_RAM3_CONFLICT ;hw4
ATH:00862Ch - WLAN_CPU_RAM4_CONFLICT ;hw4

      0-11   CNT
      12-31  -

     ______________________ hw6 MISC Registers ______________________

ATH:010028h - WLAN_AHB_CONFIG ;hw6

      0      MAX_BURST_4
      1      MAX_BURST_8
      2      MAX_BURST_16

ATH:01002Ch - WLAN_MEMORY_MAP ;hw6

      0      ONE_IRAM_BANK
      1      TWO_IRAM_BANKS
      2      THREE_IRAM_BANKS
      3      FOUR_IRAM_BANKS

     ______________________ Xtensa CPU ______________________

Xtensa Region/MMU (hw2)
The Xtensa CPU is additionally having a Region/MMU unit with ITLB and DTLB. The AR6002 ROM is doing some basic initialization via mmu-opcodes:

      set ITLB[(0..7)*20000000h] to values (1,2,2,2,2,2,2,2)
      set DTLB[(0..7)*20000000h] to values (1,2,2,2,2,2,2,2)

Alongsides, it's issuing an "isync" opcode after setting the first ITLB entry, and a "dsync" opcode after setting the last DTLB entry. After that initialization, the ROM and Firmware aren't using any further mmu-opcodes.

DSi Atheros Wifi - Internal I/O - 00C000h - Serial UART (hw2/hw4/hw6)

The UART_xxx registers are used to output TTY messages (ASCII strings) when enabled in the "Host Interest" area:

      LOCAL_SCRATCH[0].bit1 AR6K_OPTION_SERIAL_ENABLE --> TTY master enable
      targaddr[14h] hi_serial_enable --> enable additional TTY msg's during BMI
      targaddr[60h] hi_desired_baud_rate --> for TTY/UART (default=9600 decimal)
      targaddr[C4h] hi_console_flags - whatever, UART related, maybe newer firmware

     ______________________ hw2 UART Registers ______________________

Texas Instruments TL16C550AN - Asynchronous Communications Element (ACE)
The hw2 UART is based on the TL16C550AN chip (which is also found in the SNES "Exertainment Bicycle" add-on).
ATH:00C000h (when DLAB=0) - (WLAN_UART_)RBR - RX Data FIFO (R) ;hw2
ATH:00C020h (when DLAB=0) - (WLAN_UART_)SRBR (mirror of RBR?) ;hw2

      0-7  Data (with 16-byte FIFO)

ATH:00C000h (when DLAB=0) - (WLAN_UART_)THR - TX Data FIFO (W) ;hw2

      0-7  Data (with 16-byte FIFO)

ATH:00C004h (when DLAB=0) - (WLAN_UART_)IER - Interrupt Control (R/W) ;hw2

      0    ERBFI Received Data Available Interrupt            (0=Disable, 1=Enable)
      1    ETBEI Transmitter Holding Register Empty Interrupt (0=Disable, 1=Enable)
      2    ELSI  Receiver Line Status Interrupt               (0=Disable, 1=Enable)
      3    EDDSI Modem Status Interrupt                       (0=Disable, 1=Enable)
      4-7  -     Not used (always zero)

ATH:00C000h (when DLAB=1) - (WLAN_UART_)DLL - Baudrate Divisor LSB (R/W) ;hw2
ATH:00C004h (when DLAB=1) - (WLAN_UART_)DLH - Baudrate Divisor MSB (R/W) ;hw2

      0-7  Divisor Latch LSB/MSB, should be set to "divisor = XIN / (baudrate*16)"

ATH:00C008h - (WLAN_UART_)IIR - Interrupt Status (R) ;hw2
ATH:00C028h - (WLAN_UART_)SIIR (mirror or IIR?) ;hw2

      0    Interrupt Pending Flag (0=Pending, 1=None)                       ;\IID
      1-3  Interrupt ID, 3bit     (0..7=see below) (always 00h when Bit0=1) ;/
      4-5  Not used (always zero)
      6    FIFOs Enabled (always zero in TL16C450 mode) ;\these bits have same
      7    FIFOs Enabled (always zero in TL16C450 mode) ;/value as "FIFO Enable"

The 3bit Interrupt ID can have following values:

      ID Prio Expl.
      00h 4   Handshaking inputs CTS,DSR,RI,DCD have changed      (Ack: Read MSR)
      01h 3   Transmitter Holding Register Empty     (Ack: Write THR or Read IIR)
      02h 2   RX FIFO has reached selected trigger level          (Ack: Read RBR)
      03h 1   RX Overrun/Parity/Framing Error, or Break Interrupt (Ack: Read LSR)
      06h 2   RX FIFO non-empty & wasn't processed for longer time(Ack: Read RBRh)

Interrupt ID values 04h,05h,07h are not used.
ATH:00C008h - (WLAN_UART_)FCR - FIFO Control (W) ;hw2

      0    FIFO Enable (0=Disable, 1=Enable) (Enables access to FIFO related bits)
      1    Receiver FIFO Reset      (0=No Change, 1=Clear RX FIFO) (RCVR_FIFO_RST)
      2    Transmitter FIFO Reset   (0=No Change, 1=Clear TX FIFO) (XMIT_FIFO_RST)
      3    DMA Mode Select (Mode for /RXRDY and /TXRDY) (0=Mode 0, 1=Mode 1)
      4-5  Not used (should be zero)
      6-7  Receiver FIFO Trigger    (0..3 = 1,4,8,14 bytes) (RCVR_TRIG)

ATH:00C00Ch - (WLAN_UART_)LCR - Character Format Control (R/W) ;hw2

      0-1  Character Word Length    (0..3 = 5,6,7,8 bits) (CLS)
      2    Number of Stop Bits      (0=1bit, 1=2bit; for 5bit chars: only 1.5bit)
      3    Parity Enable (PEN)      (0=None, 1=Enable Parity or 9th data bit)
      4    Parity Type/9th Data bit (0=Odd, 1=Even) (EPS)
      5    Unused in hw2? ;for TL16C550AN: Bit4-5 can be 2=Set9thBit, 3=Clear9thBit
      6    Set Break                (0=Normal, 1=Break, Force SOUT to Low)
      7    Divisor Latch Access     (0=Normal I/O, 1=Divisor Latch I/O) (DLAB)

ATH:00C010h - (WLAN_UART_)MCR - Handshaking Control (R/W) ;hw2

      0    DTR  Output Level for /DTR pin  (Data Terminal Ready) (0=High, 1=Low)
      1    RTS  Output Level for /RTS pin  (Request to Send)     (0=High, 1=Low)
      2    OUT1 Output Level for /OUT1 pin (General Purpose)     (0=High, 1=Low)
      3    OUT2 Output Level for /OUT2 pin (General Purpose)     (0=High, 1=Low)
      4/5? LOOP Loopback Mode (0=Normal, 1=Testmode, loopback TX to RX)
      5-7  Not used (always zero)

The Loopback bit should be Bit4 (according to TL16C550AN datasheet), but hw2 source code claims it to be in bit5.
ATH:00C014h - (WLAN_UART_)LSR - RX/TX Status (R) (W=don't do) ;hw2
ATH:00C034h - (WLAN_UART_)SLSR (mirror of LSR?) ;hw2

      0    RX Data Ready (DR)       (0=RX FIFO Empty, 1=RX Data Available)
      1    RX Overrun Error (OE)    (0=Okay, 1=Error) (RX when RX FIFO Full)
      2    RX Parity Error (PE)     (0=Okay, 1=Error) (RX parity bad)
      3    RX Framing Error (FE)    (0=Okay, 1=Error) (RX stop bit bad)
      4    RX Break Interrupt (BI)  (0=Normal, 1=Break) (RX line LOW for long time)
      5    Transmitter Holding Register (THRE) (1=TX FIFO is empty)
      6    Transmitter Empty (TEMT) (0=No, 1=Yes, TX FIFO and TX Shift both empty)
      7    At least one Overrun/Parity/Framing Error in RX FIFO (0=No, 1=Yes/Error)

Bit7 is always zero in TL16C450 mode. Bit1-3 are automatically cleared after reading. In FIFO mode, bit2-3 reflect to status of the current (=oldest) character in the FIFO (unknown/unclear if bit2-3 are also auto-cleared when in FIFO mode).
Note: The AR6002 BIOS ROM is using "SLSR" (instead of "LSR") for testing bit0,5,6. And, before each read from SLSR register, the AR6002 BIOS BIOS does first write 0 to SLSR (for whatever unknown purpose).
Basically, "SLSR" (and other "Sxxx" registers) seems to be some sort of a mirror of "LSR" (and other "xxx" registers)? Maybe one of them omits automatic IRQ acknowledge or so?
ATH:00C018h - (WLAN_UART_)MSR - Handshaking Status (R) (W=don't do) ;hw2
ATH:00C038h - (WLAN_UART_)SMSR (mirror or MSR?) ;hw2

      0    DCTS Change flag for /CTS pin ;ClearToSend       ;\change flags (0=none,
      1    DDSR Change flag for /DSR pin ;DataSetReady      ; 1=changed since last
      2    TERI Change flag for /RI pin  ;RingIndicator     ; read) (automatically
      3    DDCD Change flag for /DCD pin ;DataCarrierDetect ;/cleared after read)
      4    CTS  Input Level on /CTS pin ;ClearToSend        ;\
      5    DSR  Input Level on /DSR pin ;DataSetReady       ; current levels
      6    RI   Input Level on /RI pin  ;RingIndicator      ; (inverted ?)
      7    DCD  Input Level on /DCD pin ;DataCarrierDetect  ;/

ATH:00C01Ch - (WLAN_UART_)SCR - Scratch (R/W) ;hw2

      0-7  General Purpose Storage (eg. read/write-able for UART chip detection)

ATH:00C02Ch - (WLAN_UART_?)MWR ;whatever "M Write Register?" ;hw2
ATH:00C03Ch - (WLAN_UART_?)MRR ;whatever "M Read Register?" ;hw2

      0-31 whatever... 32bit wide (unlike other UART registers) (?) (UART related?)

     ______________________ hw4/hw6 UART Registers ______________________

Multiple UARTs ;hw4/hw6
There appear to be multiple hw4/hw6 UARTs: one normal, one for debug, one for hw6:

      WLAN_UART_BASE_ADDRESS     = 0000C000h ;hw4/hw6
      WLAN_DBG_UART_BASE_ADDRESS = 0000D000h ;hw4/hw6
      WLAN_UART2_BASE_ADDRESS    = 00054C00h ;hw6

Maybe the UARTs are all using the same register format with differerent base?
ATH:00C000h - UART_DATA ;hw4/hw6

      0-7    TXRX_DATA
      8      RX_CSR
      9      TX_CSR

ATH:00C004h - UART_CONTROL ;hw4/hw6

      0      PARITY_EVEN
      1      PARITY_ENABLE
      2      IFC_DCE
      3      IFC_ENABLE
      4      FLOW_INVERT
      5      FLOW_ENABLE
      6      DMA_ENABLE
      7      RX_READY_ORIDE
      8      TX_READY_ORIDE
      9      SERIAL_TX_READY
      10     RX_BREAK
      11     TX_BREAK
      12     HOST_INT
      13     HOST_INT_ENABLE
      14     TX_BUSY
      15     RX_BUSY

ATH:00C008h - UART_CLKDIV ;hw4/hw6

      0-15   CLK_STEP
      16-23  CLK_SCALE

ATH:00C00Ch - UART_INT ;hw4/hw6
ATH:00C010h - UART_INT_EN ;hw4/hw6

      0      RX_VALID_INT
      1      TX_READY_INT
      2      RX_FRAMING_ERR_INT
      3      RX_OFLOW_ERR_INT
      4      TX_OFLOW_ERR_INT
      5      RX_PARITY_ERR_INT
      6      RX_BREAK_ON_INT
      7      RX_BREAK_OFF_INT
      8      RX_FULL_INT
      9      TX_EMPTY_INT

DSi Atheros Wifi - Internal I/O - 00E000h - UMBOX Registers (hw4/hw6)

ATH:00E000h..00E004h - UMBOX_FIFO[0..1]

      0-8    DATA   ... uh, twice[0..1], with 9bit each ?

ATH:00E008h - UMBOX_FIFO_STATUS

      0      RX_FULL
      1      RX_EMPTY
      2      TX_FULL
      3      TX_EMPTY

ATH:00E00Ch - UMBOX_DMA_POLICY

      0      RX_ORDER
      1      RX_QUANTUM
      2      TX_ORDER
      3      TX_QUANTUM

ATH:00E010h - UMBOX0_DMA_RX_DESCRIPTOR_BASE
ATH:00E018h - UMBOX0_DMA_TX_DESCRIPTOR_BASE

      2-27   ADDRESS

ATH:00E014h - UMBOX0_DMA_RX_CONTROL
ATH:00E01Ch - UMBOX0_DMA_TX_CONTROL

      0      STOP
      1      START
      2      RESUME

ATH:00E020h - UMBOX_FIFO_TIMEOUT

      0-7    VALUE
      8      ENABLE_SET

ATH:00E024h - UMBOX_INT_STATUS
ATH:00E028h - UMBOX_INT_ENABLE

      0      RX_NOT_FULL
      1      TX_NOT_EMPTY
      2      RX_UNDERFLOW
      3      TX_OVERFLOW
      4      HCI_SYNC_ERROR
      5      TX_DMA_COMPLETE
      6      TX_DMA_EOM_COMPLETE
      7      RX_DMA_COMPLETE
      8      HCI_FRAMER_OVERFLOW
      9      HCI_FRAMER_UNDERFLOW

ATH:00E02Ch - UMBOX_DEBUG

      0-2    SEL

ATH:00E030h - UMBOX_FIFO_RESET

      0      INIT

ATH:00E034h - UMBOX_HCI_FRAMER

      0-1    CONFIG_MODE
      2      OVERFLOW
      3      UNDERFLOW
      4      SYNC_ERROR
      5      ENABLE
      6      CRC_OVERRIDE

DSi Atheros Wifi - Internal I/O - 010000h - Serial I2C/SPI (hw2/hw4/hw6)

These registers are providing a general purpose I2C/SPI serial bus. The SI_xxx registers are exactly same in hw2/hw4/hw6.
In the DSi, they are used in I2C mode - for reading wifi calibration data:
DSi Atheros Wifi I2C EEPROM
ATH:010000h - SI_CONFIG

      0-3    DIVIDER            (probably transfer rate, should be 6 on DSi)
      4      INACTIVE_CLK       (whatever, should be 1 for I2C)
      5      INACTIVE_DATA      (whatever, should be 1 for I2C)
      6      POS_DRIVE          (whatever, should be zero for I2C)
      7      POS_SAMPLE         (whatever, should be 1 for I2C)
      8-15   -
      16     I2C                (0=SPI, 1=I2C)
      17     -
      18     BIDIR_OD_DATA      (whatever, should be 1 for I2C)
      19     ERR_INT            (whatever, enable or status?)

On DSi, this is register is set to 500B6h.
ATH:010004h - SI_CS

      0-3    TX_CNT    Number of TX bytes (0..8) (should be 1..8 for I2C device)
      4-7    RX_CNT    Number of RX bytes (0..8)
      8      START     Write 1 to start transfer
      9      DONE_INT  Status (0=Busy, 1=Done/Okay)
      10     DONE_ERR  Status (1=Error)
      11-13  BIT_CNT_IN_LAST_BYTE (0=Normal/8bit, 1..7=whatever)

For I2C with TX_CNT and RX_CNT both nonzero: TX data is transferred first.
Unknown when the DONE flags are cleared (possibly when writing 0 to bit9,10, or when writing 1 to bit8, or maybe automatically after reading).
ATH:010008h..01000Ch - SI_TX_DATA0/SI_TX_DATA1

      0-7    DATA0  1st TX byte (device number in case of I2C mode)
      8-15   DATA1  2nd TX byte (if any)
      16-23  DATA2  ...
      24-31  DATA3  ..
      32-39  DATA4
      40-47  DATA5
      48-55  DATA6
      56-63  DATA7

ATH:010010h..010014h - SI_RX_DATA0/SI_RX_DATA1

      0-7    DATA0  1st RX byte (if any)
      8-15   DATA1  2nd RX byte (if any)
      16-23  DATA2  ...
      24-31  DATA3  ..
      32-39  DATA4
      40-47  DATA5
      48-55  DATA6
      56-63  DATA7

DSi Atheros Wifi - Internal I/O - 014000h - GPIO 18/26/57 pin (hw2/hw4/hw6)

ATH:014000h/014000h/014000h - WLAN_GPIO_OUT ;GPIO Data Out ;hw2/hw4/hw6
ATH:014004h/014004h/014004h - WLAN_GPIO_OUT_W1TS ;Write-1-to-Set ;hw2/hw4/hw6
ATH:014008h/014008h/014008h - WLAN_GPIO_OUT_W1TC ;Write-1-to-Clr ;hw2/hw4/hw6
ATH:01400Ch - WLAN_GPIO_OUT_HIGH ;for pin32 and up ;hw6
ATH:014010h - WLAN_GPIO_OUT_W1TS_HIGH ;for pin32 and up ;hw6
ATH:014014h - WLAN_GPIO_OUT_W1TC_HIGH ;for pin32 and up ;hw6

      0-17   hw2: DATA (for pin 0..17)
      0-25   hw4: DATA (for pin 0..25)
      0-63   hw6: DATA (for pin 0..56) (and bit57-63=unused or so?)

ATH:01400Ch/01400Ch/014018h - WLAN_GPIO_ENABLE ;GPIO Out Enable ;hw2/hw4/hw6
ATH:014010h/014010h/01401Ch - WLAN_GPIO_ENABLE_W1TS ;Wr-1-to-Set ;hw2/hw4/hw6
ATH:014014h/014014h/014020h - WLAN_GPIO_ENABLE_W1TC ;Wr-1-to-Clr ;hw2/hw4/hw6
ATH:014024h - WLAN_GPIO_ENABLE_HIGH ;for pin32 and up ;hw6
ATH:014028h - WLAN_GPIO_ENABLE_W1TS_HIGH ;for pin32 and up ;hw6
ATH:01402Ch - WLAN_GPIO_ENABLE_W1TC_HIGH ;for pin32 and up ;hw6

      0-17   hw2: DATA (for pin 0..17)
      0-25   hw4: DATA (for pin 0..25)
      0-63   hw6: DATA (for pin 0..56) (and bit57-63=unused or so?)

ATH:014018h/014018h/014030h - WLAN_GPIO_IN - GPIO Data In ;hw2/hw4/hw6
ATH:014038h - WLAN_GPIO_IN_HIGH ;for pin32 and up ;hw6

      0-17   hw2: DATA (for pin 0..17)
      0-25   hw4: DATA (for pin 0..25)
      0-63   hw6: DATA (for pin 0..56) (and bit57-63=unused or so?)

ATH:01401Ch/01401Ch/014034h - WLAN_GPIO_STATUS - GPIO Interrupt ;hw2/hw4/hw6
ATH:014020h/014020h/014040h - WLAN_GPIO_STATUS_W1TS ;Wr-1-to-Set ;hw2/hw4/hw6
ATH:014024h/014024h/014044h - WLAN_GPIO_STATUS_W1TC ;Wr-1-to-Clr ;hw2/hw4/hw6
ATH:01403Ch - WLAN_GPIO_STATUS_HIGH ;for pin32 and up ;hw6
ATH:014048h - WLAN_GPIO_STATUS_W1TS_HIGH ;for pin32 and up ;hw6
ATH:01404Ch - WLAN_GPIO_STATUS_W1TC_HIGH ;for pin32 and up ;hw6

      0-17   hw2: INTERRUPT (for pin 0..17)
      0-25   hw4: INTERRUPT (for pin 0..25)
      0-63   hw6: INTERRUPT (for pin 0..56) (and bit57-63=unused or so?)

     ______________________________ hw2 GPIO ports ______________________________

ATH:014028h - GPIO_PIN0 ;GPIO0 Bluetooth coex BT_PRIORITY
ATH:01402Ch - GPIO_PIN1 ;GPIO1 Bluetooth coex WLAN_ACTIVE
ATH:014030h - GPIO_PIN2 ;GPIO2 Bluetooth coex BT_FREQUENCY ;I2C SCL
ATH:014034h - GPIO_PIN3 ;GPIO3 Bluetooth coex BT_ACTIVE ;I2C_SDA
ATH:014038h - GPIO_PIN4 ;GPIO4 SDIO/GSPI interface select
ATH:01403Ch - GPIO_PIN5 ;GPIO5 SDIO/GSPI interface select
ATH:014040h - GPIO_PIN6 ;GPIO6 -
ATH:014044h - GPIO_PIN7 ;GPIO7 TRST for JTAG debug
ATH:014048h - GPIO_PIN8 ;GPIO8 external 32kHz clock in
ATH:01404Ch - GPIO_PIN9 ;GPIO9 I2C SCL or SPI CLK
ATH:014050h - GPIO_PIN10 ;GPIO10 I2C SDA or SPI MISO
ATH:014054h - GPIO_PIN11 ;GPIO11 UART RXD or SPI MOSI
ATH:014058h - GPIO_PIN12 ;GPIO12 UART TXD or SPI /CS
ATH:01405Ch - GPIO_PIN13 ;GPIO13 Reset in for JTAG debug
ATH:014060h - GPIO_PIN14 ;GPIO14 UART CTS
ATH:014064h - GPIO_PIN15 ;GPIO15 UART RTS
ATH:014068h - GPIO_PIN16 ;GPIO16 -
ATH:01406Ch - GPIO_PIN17 ;GPIO17 -

      0      SOURCE
      1      -
      2      PAD_DRIVER
      3-6    -
      7-9    INT_TYPE
      10     WAKEUP_ENABLE
      11-12  CONFIG

Note: The I2C EEPROM in DSi/3DS is accessed via Pin9/10 on AR6002, and Pin2/3 on AR6013/AR6014.

     ______________________________ hw4 GPIO ports ______________________________

ATH:014028h - WLAN_GPIO_PIN0 ;GPIO0 Bluetooth coex BT_FREQUENCY
ATH:01402Ch - WLAN_GPIO_PIN1 ;GPIO1 Bluetooth coex WLAN_ACTIVE
ATH:014030h - WLAN_GPIO_PIN2 ;GPIO2 Bluetooth coex BT_ACTIVE
ATH:014034h - WLAN_GPIO_PIN3 ;GPIO3 Bluetooth coex BT_PRIORITY
ATH:014038h - WLAN_GPIO_PIN4 ;GPIO4 -
ATH:01403Ch - WLAN_GPIO_PIN5 ;GPIO5 JTAG TMS input
ATH:014040h - WLAN_GPIO_PIN6 ;GPIO6 JTAG TCK input
ATH:014044h - WLAN_GPIO_PIN7 ;GPIO7 JTAG TDI input
ATH:014048h - WLAN_GPIO_PIN8 ;GPIO8 JTAG TDO output
ATH:01404Ch - WLAN_GPIO_PIN9 ;GPIO9 SDIO CMD
ATH:014050h - WLAN_GPIO_PIN10 ;GPIO10 SDIO D3
ATH:014054h - WLAN_GPIO_PIN11 ;GPIO11 SDIO D2
ATH:014058h - WLAN_GPIO_PIN12 ;GPIO12 SDIO D1
ATH:01405Ch - WLAN_GPIO_PIN13 ;GPIO13 SDIO D0
ATH:014060h - WLAN_GPIO_PIN14 ;GPIO14 SDIO CLK
ATH:014064h - WLAN_GPIO_PIN15 ;GPIO15 HCI UART TXD
ATH:014068h - WLAN_GPIO_PIN16 ;GPIO16 HCI UART RTS
ATH:01406Ch - WLAN_GPIO_PIN17 ;GPIO17 HCI UART RXD
ATH:014070h - WLAN_GPIO_PIN18 ;GPIO18 HCI UART CTS
ATH:014074h - WLAN_GPIO_PIN19 ;GPIO19 SDIO/GSPI interface select
ATH:014078h - WLAN_GPIO_PIN20 ;GPIO20 SDIO/GSPI interface select
ATH:01407Ch - WLAN_GPIO_PIN21 ;GPIO21 external input sleep clock
ATH:014080h - WLAN_GPIO_PIN22 ;GPIO22 wake on wireless input (WOW)
ATH:014084h - WLAN_GPIO_PIN23 ;GPIO23 reference clk output to BT chip
ATH:014088h - WLAN_GPIO_PIN24 ;GPIO24 request clk from BT chip
ATH:01408Ch - WLAN_GPIO_PIN25 ;GPIO25 request reference clk (CLK_REQ)

      0      SOURCE
      1      -
      2      PAD_DRIVER
      3-4    PAD_STRENGTH   ;\pull/strength supported for PIN0..PIN22 only
      5-6    PAD_PULL       ;/(bit3-6 are unused in PIN23..PIN25 registers)
      7-9    INT_TYPE
      10     WAKEUP_ENABLE
      11-13  CONFIG

AR6003 datasheet assigns only the above stuff with a single UART, although the AR6003 should additionally support a DBG_UART (and I2C).

     ______________________________ hw6 GPIO ports ______________________________

ATH:014050h - WLAN_GPIO_PIN0 ;GPIO0 or SDIO_CMD
ATH:014054h - WLAN_GPIO_PIN1 ;GPIO1 or SDIO_D3
ATH:014058h - WLAN_GPIO_PIN2 ;GPIO2 or SDIO_D2
ATH:01405Ch - WLAN_GPIO_PIN3 ;GPIO3 or SDIO_D1
ATH:014060h - WLAN_GPIO_PIN4 ;GPIO4 or SDIO_D0
ATH:014064h - WLAN_GPIO_PIN5 ;GPIO5 or SDIO_CLK
ATH:014068h - WLAN_GPIO_PIN6
ATH:01406Ch - WLAN_GPIO_PIN7
ATH:014070h - WLAN_GPIO_PIN8
ATH:014074h - WLAN_GPIO_PIN9
ATH:014078h - WLAN_GPIO_PIN10
ATH:01407Ch - WLAN_GPIO_PIN11
ATH:014080h - WLAN_GPIO_PIN12
ATH:014084h - WLAN_GPIO_PIN13
ATH:014088h - WLAN_GPIO_PIN14
ATH:01408Ch - WLAN_GPIO_PIN15
ATH:014090h - WLAN_GPIO_PIN16
ATH:014094h - WLAN_GPIO_PIN17
ATH:014098h - WLAN_GPIO_PIN18
ATH:01409Ch - WLAN_GPIO_PIN19
ATH:0140A0h - WLAN_GPIO_PIN20
ATH:0140A4h - WLAN_GPIO_PIN21
ATH:0140A8h - WLAN_GPIO_PIN22
ATH:0140ACh - WLAN_GPIO_PIN23
ATH:0140B0h - WLAN_GPIO_PIN24
ATH:0140B4h - WLAN_GPIO_PIN25
ATH:0140B8h - WLAN_GPIO_PIN26
ATH:0140BCh - WLAN_GPIO_PIN27
ATH:0140C0h - WLAN_GPIO_PIN28
ATH:0140C4h - WLAN_GPIO_PIN29
ATH:0140C8h - WLAN_GPIO_PIN30
ATH:0140CCh - WLAN_GPIO_PIN31
ATH:0140D0h - WLAN_GPIO_PIN32
ATH:0140D4h - WLAN_GPIO_PIN33
ATH:0140D8h - WLAN_GPIO_PIN34
ATH:0140DCh - WLAN_GPIO_PIN35
ATH:0140E0h - WLAN_GPIO_PIN36
ATH:0140E4h - WLAN_GPIO_PIN37
ATH:0140E8h - WLAN_GPIO_PIN38
ATH:0140ECh - WLAN_GPIO_PIN39
ATH:0140F0h - WLAN_GPIO_PIN40
ATH:0140F4h - WLAN_GPIO_PIN41
ATH:0140F8h - WLAN_GPIO_PIN42
ATH:0140FCh - WLAN_GPIO_PIN43
ATH:014100h - WLAN_GPIO_PIN44
ATH:014104h - WLAN_GPIO_PIN45
ATH:014108h - WLAN_GPIO_PIN46
ATH:01410Ch - WLAN_GPIO_PIN47
ATH:014110h - WLAN_GPIO_PIN48
ATH:014114h - WLAN_GPIO_PIN49
ATH:014118h - WLAN_GPIO_PIN50
ATH:01411Ch - WLAN_GPIO_PIN51
ATH:014120h - WLAN_GPIO_PIN52
ATH:014124h - WLAN_GPIO_PIN53
ATH:014128h - WLAN_GPIO_PIN54
ATH:01412Ch - WLAN_GPIO_PIN55
ATH:014130h - WLAN_GPIO_PIN56

      0      SOURCE
      1      -
      2      PAD_DRIVER
      3-4    PAD_STRENGTH
      5-6    PAD_PULL
      7-9    INT_TYPE
      10     WAKEUP_ENABLE
      11-14  CONFIG

AR6004 datasheet assigns only six SDIO signals to GPIO pins. However, signals similar as on AR6002/AR6003 should exist (I2C/SPI, UART, etc.), plus TWO additional UARTs).

     _____________________________ hw2/hw4/hw6 stuff _____________________________

ATH:014078h/01409Ch/01413Ch - WLAN_SIGMA_DELTA ;hw2/hw4/hw6

      0-7    TARGET
      8-15   PRESCALAR      ;uh, scalar?
      16     ENABLE

ATH:01407Ch/0140A8h/01414Ch - WLAN_DEBUG_CONTROL ;hw2/hw4/hw6

      0      ENABLE                 ;-hw2/hw4/hw6
      1      hw2: OBS_OE_L          ;-hw2 only (bit1 removed in hw4/hw6)

ATH:014080h/0140ACh/014150h - WLAN_DEBUG_INPUT_SEL ;hw2/hw4/hw6

      0-3    SRC                    ;-hw2/hw4/hw6
      4-5    hw4/hw6: SHIFT         ;-hw4/hw6

ATH:014084h/0140B0h/014154h - WLAN_DEBUG_OUT ;hw2/hw4/hw6

      0-17   DATA (whatever) (always 18bit, no matter if GPIO with 18,25,57 pins)

ATH:0140F0h/0140B4h/014158h - WLAN_RESET_TUPLE_STATUS ;hw2/hw4/hw6

      0-7    PIN_RESET_TUPLE
      8-11   TEST_RESET_TUPLE

     _______________________________ hw4/hw6 stuff _______________________________

ATH:014090h/014134h - SDIO ;hw4/hw6
ATH:014160h - SDIO2 ;hw6
ATH:014164h - SDHC ;hw6

      0      PINS_EN

ATH:014098h/014138h - WL_SOC_APB ;hw4/hw6

      0      TOGGLE

ATH:0140A0h/014140h - WL_BOOTSTRAP ;hw4/hw6

      0-22   hw4: STATUS (23bit) ;maybe for pin 0..22 (but not pin 23-25 ?)
      0-11   hw6: STATUS (12bit) ;maybe for pin 0..57 (with below "CORE_BOOTSTRAP")
      12     hw6: CPU_MBIST_EN

ATH:014144h - CORE_BOOTSTRAP_LOW ;hw6

      0-31   hw6: STATUS (32bit) (extra bits, expanding STATUS in "WL_BOOTSTRAP"?)

ATH:014148h - CORE_BOOTSTRAP_HIGH ;hw6

      0-12   hw6: STATUS (13bit) (extra bits, expanding STATUS in "WL_BOOTSTRAP"?)

ATH:0140B8h/01415Ch - ANTENNA_SLEEP_CONTROL/ANTENNA_CONTROL ;hw4/hw6

      0-4    hw4: ENABLE   (5bit)           ;\
      5-9    hw4: VALUE    (5bit)           ; hw4 "ANTENNA_SLEEP_CONTROL"
      10-14  hw4: OVERRIDE (5bit)           ;/
      0-3    hw6: ENABLE   (4bit)           ;\
      4-7    hw6: VALUE    (4bit)           ;
      8-11   hw6: OVERRIDE (4bit)           ;
      12-13  hw6: LED_SEL  (2bit)           ; hw6 "ANTENNA_CONTROL"
      14     hw6: SPI_MODE                  ;
      15     hw6: SPI_CS                    ;
      16     hw6: RX_CLEAR                  ;/

     _________________________________ hw6 stuff _________________________________

ATH:014168h - AMBA_DEBUG_BUS ;hw6

      0-4    SEL

ATH:01416Ch - CPU_MBIST ;hw6

      0      DONE
      1      GLOBAL_FAIL
      2-10   BLOCK_FAIL

     _________________________________ hw4 stuff _________________________________

ATH:014094h - FUNC_BUS ;hw4

      0-21   OE_L
      22     GPIO_MODE

ATH:0140A4h - CLOCK_GPIO ;hw4

      0      hw4: BT_CLK_OUT_EN
      1      hw4: BT_CLK_REQ_EN
      2      hw4: CLK_REQ_OUT_EN

     ____________________________ hw2 GPIO PIN config ____________________________

ATH:0140D4h - ANTD_PIN - Config: Pad Pull ;hw2
ATH:0140DCh - GPIO_H_PIN - Config: Pad Pull ;hw2
ATH:0140E4h - BT_WLAN_PIN - Config: Pad Pull ;hw2
ATH:0140ECh - CLK32K_PIN - Config: Pad Pull ;hw2

      0-1    hw2: PAD_PULL

ATH:014070h - SDIO_PIN - Config: Pad Pull/Strength ;hw2
ATH:0140D0h - ANT_PIN - Config: Pad Pull/Strength ;hw2
ATH:0140D8h - GPIO_PIN - Config: Pad Pull/Strength ;hw2
ATH:0140E0h - BT_PIN - Config: Pad Pull/Strength ;hw2
ATH:0140E8h - SI_UART_PIN - Config: Pad Pull/Strength ;hw2

      0-1    hw2: PAD_STRENGTH
      2-3    hw2: PAD_PULL

ATH:014074h - CLK_REQ_PIN - Config: Pad Pull/Strength/AteOeLow ;hw2

      0-1    hw2: PAD_STRENGTH
      2-3    hw2: PAD_PULL
      4      hw2: ATE_OE_L

     _______________________________ hw2 LA stuff _______________________________

ATH:014088h - LA_CONTROL ;hw2

      0      hw2: TRIGGERED
      1      hw2: RUN

ATH:01408Ch - LA_CLOCK ;hw2

      0-7    hw2: DIV

ATH:014090h - LA_STATUS ;hw2

      0      hw2: INTERRUPT

ATH:014094h - LA_TRIGGER_SAMPLE ;hw2

      0-15   hw2: COUNT

ATH:014098h - LA_TRIGGER_POSITION ;hw2

      0-15   hw2: VALUE

ATH:01409Ch - LA_PRE_TRIGGER ;hw2
ATH:0140A0h - LA_POST_TRIGGER ;hw2

      0-15   hw2: COUNT

ATH:0140A4h - LA_FILTER_CONTROL ;hw2

      0      hw2: DELTA

ATH:0140A8h - LA_FILTER_DATA ;hw2
ATH:0140B0h - LA_TRIGGERA_DATA ;hw2
ATH:0140B8h - LA_TRIGGERB_DATA ;hw2
ATH:0140ACh - LA_FILTER_WILDCARD ;hw2
ATH:0140B4h - LA_TRIGGERA_WILDCARD ;hw2
ATH:0140BCh - LA_TRIGGERB_WILDCARD ;hw2

      0-17   hw2: MATCH                 ... maybe related to GPIO_PIN0..17 ?

ATH:0140C0h - LA_TRIGGER ;hw2

      0-2    hw2: EVENT

ATH:0140C4h - LA_FIFO ;hw2

      0      hw2: EMPTY
      1      hw2: FULL

ATH:0140C8h..0140CCh - LA[0..1] ;hw2

      0-17   hw2: DATA

DSi Atheros Wifi - Internal I/O - 018000h - MBOX Registers (hw2/hw4/hw6)

These registers are same in hw2/hw4/hw6, except that:

      GMBOX registers exist in hw4/hw6 only
      STE_MODE register exists in hw6 only
      WLAN_MBOX_INT_xxx bit18,19 exist in hw6 only

And, register names didn't have had the "WLAN_" prefix in hw2.

     ___________________________ Manual MBOX Transfer ___________________________

ATH:018000h..01800Ch - WLAN_MBOX_FIFO[0..3]

      0-7    DATA: DATABYTE
      8-11   DATA: zero?
      12-15  DATA: zero? maybe copy of MBOX_FIFO_STATUS bit12-15 ? (FULL)
      16-19  DATA: looks like copy of MBOX_FIFO_STATUS bit16-19 ?  (EMPTY)
      20-31  -

READ: Allows to read incoming MBOX data; before reading this register, the data MUST be manually copied to this register via WLAN_MBOX_TXFIFO_POP[n], then read this register, and check the EMPTY flag; this requires "double indexing" as so: for MBOX(n), test "WLAN_MBOX_FIFO[n].bit(16+n)", if the bit is zero, then bit0-7 contains valid data.
WRITE: Allows to send outgoing MBOX data (write the databyte, with zeroes in bit8-31); before doing so, one SHOULD check if the FIFO is full via WLAN_MBOX_FIFO_STATUS.
ATH:0180F0h..0180FCh - WLAN_MBOX_TXFIFO_POP[0..3]

      0      DATA  ... uh 4x1bit ?   for MBOX0..3 ?
      1-31   -

Writing 0 to WLAN_MBOX_TXFIFO_POP[n] does remove the oldest "TXFIFO" entry (the data transmitted from SDIO side to xtensa side via MBOXn), and stores that value (and a copy of the WLAN_MBOX_FIFO_STATUS bits) in WLAN_MBOX_FIFO[n].
ATH:018100h..01810Ch - WLAN_MBOX_RXFIFO_POP[0..3]

      0      DATA  ... uh 4x1bit ?   for MBOX0..3 ?
      1-31   -

Probably similar as above, but for opposite direction (ie. allowing to read data that was "sent-to-the-host"; normally such data should be read by the host, so one would use this feature only if one wants to screw up the normal transfer flow).

     ____________________________ DMA MBOX Transfer ____________________________

ATH:018014h - WLAN_MBOX_DMA_POLICY

      0      RX_ORDER
      1      RX_QUANTUM
      2      TX_ORDER
      3      TX_QUANTUM
      4-31   -

ATH:018018h - WLAN_MBOX0_DMA_RX_DESCRIPTOR_BASE
ATH:018020h - WLAN_MBOX0_DMA_TX_DESCRIPTOR_BASE
ATH:018028h - WLAN_MBOX1_DMA_RX_DESCRIPTOR_BASE
ATH:018030h - WLAN_MBOX1_DMA_TX_DESCRIPTOR_BASE
ATH:018038h - WLAN_MBOX2_DMA_RX_DESCRIPTOR_BASE
ATH:018040h - WLAN_MBOX2_DMA_TX_DESCRIPTOR_BASE
ATH:018048h - WLAN_MBOX3_DMA_RX_DESCRIPTOR_BASE
ATH:018050h - WLAN_MBOX3_DMA_TX_DESCRIPTOR_BASE
ATH:018114h - WLAN_GMBOX0_DMA_RX_DESCRIPTOR_BASE - hw4/hw6 only
ATH:01811Ch - WLAN_GMBOX0_DMA_TX_DESCRIPTOR_BASE - hw4/hw6 only

      0-1    -
      2-27   ADDRESS
      28-31  -

ATH:01801Ch - WLAN_MBOX0_DMA_RX_CONTROL
ATH:018024h - WLAN_MBOX0_DMA_TX_CONTROL
ATH:01802Ch - WLAN_MBOX1_DMA_RX_CONTROL
ATH:018034h - WLAN_MBOX1_DMA_TX_CONTROL
ATH:01803Ch - WLAN_MBOX2_DMA_RX_CONTROL
ATH:018044h - WLAN_MBOX2_DMA_TX_CONTROL
ATH:01804Ch - WLAN_MBOX3_DMA_RX_CONTROL
ATH:018054h - WLAN_MBOX3_DMA_TX_CONTROL
ATH:018118h - WLAN_GMBOX0_DMA_RX_CONTROL - hw4/hw6 only
ATH:018120h - WLAN_GMBOX0_DMA_TX_CONTROL - hw4/hw6 only

      0      STOP
      1      START
      2      RESUME
      3-31   -

     __________________________________ Status __________________________________

ATH:018010h - WLAN_MBOX_FIFO_STATUS

      0-11   -
      12-15  FULL flags for MBOX 0..3
      16-19  EMPTY flags for MBOX 0..3
      20-31  -

ATH:018058h - WLAN_MBOX_INT_STATUS
ATH:01805Ch - WLAN_MBOX_INT_ENABLE

      0-7    HOST           Interrupt 0..7 from Host        ;SDIO 1:00472h.bit0..7
      8-11   RX_NOT_FULL    MBOX0..3 RX FIFO Not Full
      12-15  TX_NOT_EMPTY   MBOX0..3 TX FIFO Not Empty
      16     RX_UNDERFLOW   MBOX RX Underflow (tried to read from empty fifo)
      17     TX_OVERFLOW    MBOX TX Overflow (tried to write to full fifo)
      18     hw6: FRAME_DONE                            ;\hw6.0 only
      19     hw6: NO_RX_MBOX_DATA_AVA                   ;/
      20-23  TX_DMA_COMPLETE      MBOX0..3 TX DMA Complete
      24-27  TX_DMA_EOM_COMPLETE  MBOX0..3 TX DMA Complete .. End of message?
      28-31  RX_DMA_COMPLETE      MBOX0..3 RX DMA Complete

ATH:018124h - WLAN_GMBOX_INT_STATUS - hw4/hw6 only
ATH:018128h - WLAN_GMBOX_INT_ENABLE - hw4/hw6 only

      0      RX_NOT_FULL
      1      TX_NOT_EMPTY
      2      TX_DMA_COMPLETE
      3      TX_DMA_EOM_COMPLETE
      4      RX_DMA_COMPLETE
      5      RX_UNDERFLOW
      6      TX_OVERFLOW
      7-31   -

     ______________________________ SDIO Handshake ______________________________

ATH:018060h - WLAN_INT_HOST

      0-7    VECTOR   Interrupt 0..7 to Host                ;SDIO 1:00401h.bit0..7
      8-31   -

ATH:018080h..01809Ch - WLAN_LOCAL_COUNT[0..7]
ATH:0180A0h..0180BCh - WLAN_COUNT_INC[0..7]

      0-7    VALUE (credit counter)                         ;SDIO 1:00420h..00427h
      8-31   -

ATH:0180C0h..0180DCh - WLAN_LOCAL_SCRATCH[0..7]

      0-7    VALUE (scratch)                                ;SDIO 1:00460h..00467h
      8-31   -

ATH:0180E0h - WLAN_USE_LOCAL_BUS

      0      PIN_INIT       ;whatever, maybe PCI bus related (non-SDIO) ?
      1-31   -

ATH:0180E4h - WLAN_SDIO_CONFIG

      0      CCCR_IOR1       ;SDIO Func I/O Ready bit1 ?    ;SDIO 0:00002h.bit1
      1-31   -

ATH:01A000h..01BFFCh - WLAN_HOST_IF_WINDOW[0..2047]

      0-7    DATA                                           ;SDIO 1:00000h..007FFh
      8-31   -

Allows to access the SDIO Host registers via Internal registers, should be done only for testing purposes.

     ___________________________________ Misc ___________________________________

ATH:0180E8h - WLAN_MBOX_DEBUG

      0-2    SEL
      3-31   -

ATH:0180ECh - WLAN_MBOX_FIFO_RESET

      0      INIT
      1-31   -

ATH:018110h - WLAN_SDIO_DEBUG

      0-3    SEL
      4-31   -

ATH:01812Ch - STE_MODE - hw6.0 only

      0      SEL
      1-2    PHA_POL
      3      SEL_16BIT
      4      SWAP
      5      RST
      6      SPI_CTRL_EN

DSi Atheros Wifi - Internal I/O - 01C000h - Analog Intf (hw2)

ATH:01C000h - SYNTH_SYNTH1 ;aka - PHY_ANALOG_SYNTH1

      0      MONITOR_SYNTHLOCKVCOK
      1      MONITOR_VC2LOW
      2      MONITOR_VC2HIGH
      3      MONITOR_FB_DIV2
      4      MONITOR_REF
      5      MONITOR_FB
      6      PWUP_LOBUF5G_PD
      7      PWUP_LOMIX_PD
      8      PWUP_LODIV_PD
      9      PWUP_VCOBUF_PD
      10-12  SEL_VCMONABUS
      13     CON_IVCOBUF
      14     CON_IVCOREG
      15     CON_VDDVCOREG
      16     SPARE_PWD
      17     SLIDINGIF
      18-19  VCOREGBIAS
      20-21  VCOREGLEVEL
      22     VCOREGBYPASS
      23     PWD_LOBUF5G
      24     FORCE_LO_ON
      25     PWD_LOMIX
      26     PWD_LODIV
      27     PWD_PRESC
      28     PWD_VCO
      29     PWD_VCMON
      30     PWD_CP
      31     PWD_BIAS

ATH:01C004h - SYNTH_SYNTH2 ;aka - PHY_ANALOG_SYNTH2 (one part)

      0-2    SPARE_BITS
      3-4    LOOP_CS
      5-9    LOOP_RS
      10-14  LOOP_CP
      15-19  LOOP_3RD_ORDER_R
      20-22  VC_LOW_REF
      23-25  VC_MID_REF
      26-28  VC_HI_REF
      29-31  VC_CAL_REF

ATH:01C008h - SYNTH_SYNTH3 ;aka - PHY_ANALOG_SYNTH3

      0-5    WAIT_VC_CHECK
      6-11   WAIT_CAL_LIN
      12-17  WAIT_CAL_BIN
      18-23  WAIT_PWRUP
      24-29  WAIT_SHORTR_PWRUP
      30     SEL_CLK_DIV2
      31     DIS_CLK_XTAL

ATH:01C00Ch - SYNTH_SYNTH4 ;aka - PHY_ANALOG_SYNTH4

      0      FORCE_SHIFTREG
      1      LONGSHIFTSEL
      2-3    SPARE_MISC
      4      SEL_CLKXTAL_EDGE
      5      PSCOUNT_FBSEL
      6-7    SDM_DITHER
      8      SDM_MODE
      9      SDM_DISABLE
      10     RESET_PRESC
      11-12  PRESCSEL
      13     PFD_DISABLE
      14     PFDDELAY
      15-16  REFDIVSEL
      17     VCOCAPPULLUP
      18-25  VCOCAP_OVR
      26     FORCE_VCOCAP
      27     FORCE_PINVC
      28     SHORTR_UNTIL_LOCKED
      29     ALWAYS_SHORTR
      30     DIS_LOSTVC
      31     DIS_LIN_CAPSEARCH

ATH:01C010h - SYNTH_SYNTH5 ;aka - PHY_ANALOG_SYNTH2 (other part)

      0-1    SPARE
      2-3    LOBUF5GTUNE_OVR
      4      FORCE_LOBUF5GTUNE
      5-8    CAPRANGE3
      9-12   CAPRANGE2
      13-16  CAPRANGE1
      17-20  LOOPLEAKCUR
      21     CPLOWLK
      22     CPSTEERING_EN
      23-24  CPBIAS
      25-27  SLOPE_IP
      28-31  LOOP_IP0

ATH:01C014h - SYNTH_SYNTH6

      0-2    SPARE_BIAS
      3-4    VCOBUFBIAS
      5-7    ICVCO
      8-10   ICSPAREB
      11-13  ICSPAREA
      14-16  ICLOMIX
      17-19  ICLODIV
      20-22  ICPRESC
      23-25  IRSPARE
      26-28  IRVCMON
      29-31  IRCP

ATH:01C018h - SYNTH_SYNTH7 ;aka "PHY_ANALOG_SYNTH6" (six) on later hw

      0-2    SPARE_READ
      3-4    LOBUF5GTUNE
      5-8    LOOP_IP
      9      VC2LOW
      10     VC2HIGH
      11     RESET_SDM_B
      12     RESET_PSCOUNTERS
      13     RESET_PFD
      14     RESET_RFD
      15     SHORT_R
      16-23  VCO_CAP_ST
      24     PIN_VC
      25     SYNTH_LOCK_VC_OK
      26     CAP_SEARCH
      27-30  SYNTH_SM_STATE
      31     SYNTH_ON

ATH:01C01Ch - SYNTH_SYNTH8 ;aka "PHY_ANALOG_SYNTH7" (seven) on later hw

      0      FORCE_FRACLSB
      1-17   CHANFRAC
      18-26  CHANSEL
      27     SPARE
      28-29  AMODEREFSEL
      30     FRACMODE
      31     LOADSYNTHCHANNEL

ATH:01C020h - RF5G_RF5G1

      0-1    SPARE
      2      REGLO_BYPASS5
      3      LO5CONTROL
      4-6    LO5_ATB_SEL
      7      PDREGLO5
      8      PDLO5AGC
      9      PDQBUF5
      10     PDLO5MIX
      11     PDLO5DIV
      12-14  TX5_ATB_SEL
      15-17  OB5
      18-20  DB5
      21-23  PWDTXPKD
      24-26  TUNE_PADRV5
      27     PDPAOUT5
      28     PDPADRV5
      29     PDTXBUF5
      30     PDTXMIX5
      31     PDTXLO5

ATH:01C024h - RF5G_RF5G2

      0-1    SPARE
      2-4    TUNE_LO
      5      ENABLE_PCA
      6-7    LNA5_ATTENMODE
      8      REGFE_BYPASS5
      9-11   BVGM5
      12-14  BCSLNA5
      15-17  BRFVGA5
      18-20  TUNE_RFVGA5
      21     PDREGFE5
      22     PDRFVGA5
      23     PDCSLNA5
      24     PDVGM5
      25     PDCMOSLO5
      26-28  RX5_ATB_SEL
      29-31  AGCLO_B

ATH:01C028h - RF2G_RF2G1

      0-4    SPARE
      5      SHORTLNA2
      6      LOCONTROL
      7      SELLNA
      8-10   RF_ATB_SEL
      11-13  FE_ATB_SEL
      14-16  OB
      17-19  DB
      20-22  BLNA2
      23-25  BLNA1BUF
      26-28  BLNA1F
      29-31  BLNA1

ATH:01C02Ch - RF2G_RF2G2

      0-16   SPARE
      17     ENABLE_PCB
      18     REGLO_BYPASS
      19     REGLNA_BYPASS
      20     PDTXMIX
      21     PDTXLO
      22     PDRXLO
      23     PDRFGM
      24     PDREGLO
      25     PDREGLNA
      26     PDPAOUT
      27     PDPADRV
      28     PDDIV
      29     PDCSLNA
      30     PDCGLNABUF
      31     PDCGLNA

ATH:01C030h - TOP_GAIN

      0      SPARE
      1-2    RX6DBHIQGAIN
      3-5    RX1DBLOQGAIN
      6-7    RX6DBLOQGAIN
      8-10   RFGMGN
      11-12  RFVGA5GAIN
      13-16  LNAGAIN
      17     LNAON
      18-20  PAOUT2GN
      21-23  PADRVGN
      24     PABUF5GN
      25-26  TXV2IGAIN
      27-29  TX1DBLOQGAIN
      30-31  TX6DBLOQGAIN

ATH:01C034h - TOP_TOP

      0      FORCE_XPAON
      1      INT2GND
      2      PAD2GND
      3      INTH2PAD
      4      INT2PAD
      5-7    REVID
      8-9    DATAOUTSEL
      10     PDBIAS
      11     SYNTHON_FORCE
      12     SCLKEN_FORCE
      13     OSCON
      14     PWDCLKIN
      15     LOCALXTAL
      16     PWDDAC
      17     PWDADC
      18     PWDPLL
      19     LOCALADDAC
      20     CALTX
      21     PAON
      22     TXON
      23     RXON
      24     SYNTHON
      25     BMODE
      26     CAL_RESIDUE
      27     CALDC
      28     CALFC
      29     LOCALMODE
      30     LOCALRXGAIN
      31     LOCALTXGAIN

ATH:01C038h - BIAS_BIAS_SEL

      0      PWD_ICLDO25
      1-3    PWD_ICTXPC25
      4-6    PWD_ICTSENS25
      7-9    PWD_ICXTAL25
      10-12  PWD_ICCOMPBIAS25
      13     PWD_ICCPLL25
      14     PWD_ICREFOPAMPBIAS25
      15     PWD_IRREFMASTERBIAS12P5
      16     PWD_IRDACREGREF12P5
      17-19  PWD_ICREFBUFBIAS12P5
      20     SPARE
      21-24  SEL_SPARE
      25-30  SEL_BIAS
      31     PADON

ATH:01C03Ch - BIAS_BIAS1

      0-1    SPARE
      2-4    PWD_IC5GMIXQ25
      5-7    PWD_IC5GQB25
      8-10   PWD_IC5GTXBUF25
      11-13  PWD_IC5GTXPA25
      14     PWD_IC5GRXRF25
      15     PWD_ICDETECTORA25
      16     PWD_ICDETECTORB25
      17-19  PWD_IC2GLNAREG25
      20-22  PWD_IC2GLOREG25
      23-25  PWD_IC2GRFFE25
      26-28  PWD_IC2GVGM25
      29-31  PWD_ICDAC2BB25

ATH:01C040h - BIAS_BIAS2

      0-2    PWD_IR5GRFVREF2525
      3-5    PWD_IR2GLNAREG25
      6-8    PWD_IR2GLOREG25
      9-11   PWD_IR2GTXMIX25
      12     PWD_IRLDO25
      13-15  PWD_IRTXPC25
      16-18  PWD_IRTSENS25
      19-21  PWD_IRXTAL25
      22     PWD_IRPLL25
      23-25  PWD_IC5GLOREG25
      26-28  PWD_IC5GDIV25
      29-31  PWD_IC5GMIXI25

ATH:01C044h - BIAS_BIAS3

      0      SPARE
      1-3    PWD_ICDACREG12P5
      4-6    PWD_IR25SPARE2
      7-9    PWD_IR25SPARE1
      10-12  PWD_IC25SPARE2
      13-15  PWD_IC25SPARE1
      16     PWD_IRBB50
      17     PWD_IRSYNTH50
      18-20  PWD_IC2GDIV50
      21     PWD_ICBB50
      22     PWD_ICSYNTH50
      23-25  PWD_ICDAC50
      26-28  PWD_IR5GAGC25
      29-31  PWD_IR5GTXMIX25

ATH:01C048h - TXPC_TXPC

      0-1    ATBSEL
      2      SELCOUNT
      3-4    SELINIT
      5      ON1STSYNTHON
      6-13   N
      14-15  TSMODE
      16     SELCMOUT
      17     SELMODREF
      18     CLKDELAY
      19     NEGOUT
      20     CURHALF
      21     TESTPWDPC
      22-27  TESTDAC
      28-29  TESTGAIN
      30     TEST
      31     SELINTPD

ATH:01C04Ch - TXPC_MISC

      0-5    SPARE
      6-7    XTALDIV
      8-17   DECOUT
      18-20  SPARE_A
      21     SELTSN
      22     SELTSP
      23     LOCALBIAS2X
      24     LOCALBIAS
      25     PWDXINPAD
      26     PWDCLKIND
      27     NOTCXODET
      28     LDO_TEST_MODE
      29-30  LEVEL
      31     FLIPBMODE

ATH:01C050h - RXTXBB_RXTXBB1

      0      PDHIQ
      1      PDLOQ
      2      PDOFFSETI2V
      3      PDOFFSETHIQ
      4      PDOFFSETLOQ
      5      PDRXTXBB
      6      PDI2V
      7      PDV2I
      8      PDDACINTERFACE
      6-16   SEL_ATB
      17-18  FNOTCH
      19-31  SPARE

ATH:01C054h - RXTXBB_RXTXBB2

      0      PATH_OVERRIDE
      1      PATH1LOQ_EN
      2      PATH2LOQ_EN
      3      PATH3LOQ_EN
      4      PATH1HIQ_EN
      5      PATH2HIQ_EN
      6      FILTERDOUBLEBW
      7      LOCALFILTERTUNING
      8-12   FILTERFC
      13-14  CMSEL
      15     SEL_I2V_TEST
      16     SEL_HIQ_TEST
      17     SEL_LOQ_TEST
      18     SEL_DAC_TEST
      19     SELBUFFER
      20     SHORTBUFFER
      21-22  SPARE
      23-25  IBN_37P5_OSI2V_CTRL
      26-28  IBN_37P5_OSLO_CTRL
      29-31  IBN_37P5_OSHI_CTRL

ATH:01C058h - RXTXBB_RXTXBB3

      0-2    IBN_100U_TEST_CTRL
      3-5    IBRN_12P5_CM_CTRL
      6-8    IBN_25U_LO2_CTRL
      9-11   IBN_25U_LO1_CTRL
      12-14  IBN_25U_HI2_CTRL
      15-17  IBN_25U_HI1_CTRL
      18-20  IBN_25U_I2V_CTRL
      21-23  IBN_25U_BKV2I_CTRL
      24-26  IBN_25U_CM_BUFAMP_CTRL
      27-31  SPARE

ATH:01C05Ch - RXTXBB_RXTXBB4

      0-4    OFSTCORRI2VQ
      5-9    OFSTCORRI2VI
      10-14  OFSTCORRLOQ
      15-19  OFSTCORRLOI
      20-24  OFSTCORRHIQ
      25-29  OFSTCORRHII
      30     LOCALOFFSET
      31     SPARE

ATH:01C060h - ADDAC_ADDAC1 ;aka "A/D and D/A Converter"

      0-5    SPARE
      6      DISABLE_DAC_REG
      7-8    CM_SEL
      9      INV_CLK160_ADC
      10     SELMANPWDS
      11     FORCEMSBLOW
      12     PWDDAC
      13     PWDADC
      14     PWDPLL
      15-22  PLL_FILTER
      23-25  PLL_ICP
      26-27  PLL_ATB
      28-30  PLL_SCLAMP
      31     PLL_SVREG

ATH:01C080h - SW_OVERRIDE

      0      ENABLE
      1      SUPDATE_DELAY

ATH:01C084h - SIN_VAL

      0      SIN

ATH:01C088h - SW_SCLK

      0      SW_SCLK

ATH:01C08Ch - SW_CNTL

      0      SW_SOUT
      1      SW_SUPDATE
      2      SW_SCAPTURE

DSi Atheros Wifi - Internal I/O - 01C000h - Analog Intf (hw4/hw6)

These registers are same in hw4/hw6, except for some small differences:

      0001C050h  one new bit in hw6.0
      0001C148h  several new bits in hw6.0
      0001C740h  added/removed/renumbered bits in hw6.0
      0001C744h  two changed/renamed bits in hw6.0

ATH:01C000h - PHY_ANALOG_RXRF_BIAS1

      0      SPARE
      1-3    PWD_IR25SPARE
      4-6    PWD_IR25LO18
      7-9    PWD_IC25LO36
      10-12  PWD_IC25MXR2_5GH
      13-15  PWD_IC25MXR5GH
      16-18  PWD_IC25VGA5G
      19-21  PWD_IC75LNA5G
      22-24  PWD_IR25LO24
      25-27  PWD_IC25MXR2GH
      28-30  PWD_IC75LNA2G
      31     PWD_BIAS

ATH:01C004h - PHY_ANALOG_RXRF_BIAS2

      0      SPARE
      1-3    PKEN
      4-6    VCMVALUE
      7      PWD_VCMBUF
      8-10   PWD_IR25SPAREH
      11-13  PWD_IR25SPARE
      14-16  PWD_IC25LNABUF
      17-19  PWD_IR25AGCH
      20-22  PWD_IR25AGC
      23-25  PWD_IC25AGC
      26-28  PWD_IC25VCMBUF
      29-31  PWD_IR25VCM

ATH:01C008h - PHY_ANALOG_RXRF_GAINSTAGES

      0      SPARE
      1      LNAON_CALDC
      2-3    VGA5G_CAP
      4-5    LNA5G_CAP
      6      LNA5G_SHORTINP
      7      PWD_LO5G
      8      PWD_VGA5G
      9      PWD_MXR5G
      10     PWD_LNA5G
      11-12  LNA2G_CAP
      13     LNA2G_SHORTINP
      14     LNA2G_LP
      15     PWD_LO2G
      16     PWD_MXR2G
      17     PWD_LNA2G
      18-19  MXR5G_GAIN_OVR
      20-22  VGA5G_GAIN_OVR
      23-25  LNA5G_GAIN_OVR
      26-27  MXR2G_GAIN_OVR
      28-30  LNA2G_GAIN_OVR
      31     RX_OVERRIDE

ATH:01C00Ch - PHY_ANALOG_RXRF_AGC

      0      RF5G_ON_DURING_CALPA
      1      RF2G_ON_DURING_CALPA
      2      AGC_OUT                        (R)
      3      LNABUFGAIN2X
      4      LNABUF_PWD_OVR
      5      PWD_LNABUF
      6-8    AGC_FALL_CTRL
      9-14   AGC5G_CALDAC_OVR
      15-18  AGC5G_DBDAC_OVR
      19-24  AGC2G_CALDAC_OVR
      25-28  AGC2G_DBDAC_OVR
      29     AGC_CAL_OVR
      30     AGC_ON_OVR
      31     AGC_OVERRIDE

ATH:01C040h - PHY_ANALOG_TXRF1

      0      PDLOBUF5G
      1      PDLODIV5G
      2      LOBUF5GFORCED
      3      LODIV5GFORCED
      4-7    PADRV2GN5G
      8-11   PADRV3GN5G
      12-15  PADRV4GN5G
      16     LOCALTXGAIN5G
      17     PDOUT2G
      18     PDDR2G
      19     PDMXR2G
      20     PDLOBUF2G
      21     PDLODIV2G
      22     LOBUF2GFORCED
      23     LODIV2GFORCED
      24-30  PADRVGN2G
      31     LOCALTXGAIN2G

ATH:01C044h - PHY_ANALOG_TXRF2

      0-2    D3B5G
      3-5    D4B5G
      6-8    OCAS2G
      9-11   DCAS2G
      12-14  OB2G_PALOFF
      15-17  OB2G_QAM
      18-20  OB2G_PSK
      21-23  OB2G_CCK
      24-26  DB2G
      27-30  PDOUT5G
      31     PDMXR5G

ATH:01C048h - PHY_ANALOG_TXRF3

      0-1    FILTR2G
      2      PWDFB2_2G
      3      PWDFB1_2G
      4      PDFB2G
      5-6    RDIV5G
      7-9    CAPDIV5G
      10     PDPREDIST5G
      11-12  RDIV2G
      13     PDPREDIST2G
      14-16  OCAS5G
      17-19  D2CAS5G
      20-22  D3CAS5G
      23-25  D4CAS5G
      26-28  OB5G
      29-31  D2B5G

ATH:01C04Ch - PHY_ANALOG_TXRF4

      0-1    PK1B2G_CCK
      2-4    MIOB2G_QAM
      5-7    MIOB2G_PSK
      8-10   MIOB2G_CCK
      11-13  COMP2G_QAM
      14-16  COMP2G_PSK
      17-19  COMP2G_CCK
      20-22  AMP2B2G_QAM
      23-25  AMP2B2G_PSK
      26-28  AMP2B2G_CCK
      29-31  AMP2CAS2G

ATH:01C050h - PHY_ANALOG_TXRF5

      0      hw4: SPARE5
      0      hw6: TXMODPALONLY      ;-hw6.0 only
      1      PAL_LOCKED                     (R)
      2      FBHI2G                         (R)
      3      FBLO2G                         (R)
      4      NOPALGAIN2G
      5      ENPACAL2G
      6-12   OFFSET2G
      13     ENOFFSETCAL2G
      14-16  REFHI2G
      17-19  REFLO2G
      20-21  PALCLAMP2G
      22-23  PK2B2G_QAM
      24-25  PK2B2G_PSK
      26-27  PK2B2G_CCK
      28-29  PK1B2G_QAM
      30-31  PK1B2G_PSK

ATH:01C054h - PHY_ANALOG_TXRF6

      0      PALCLKGATE2G
      1-8    PALFLUCTCOUNT2G
      9-10   PALFLUCTGAIN2G
      11     PALNOFLUCT2G
      12-14  GAINSTEP2G
      15     USE_GAIN_DELTA2G
      16-19  CAPDIV_I2G
      20-23  PADRVGN_INDEX_I2G
      24-26  VCMONDELAY2G
      27-30  CAPDIV2G
      31     CAPDIV2GOVR

ATH:01C058h - PHY_ANALOG_TXRF7 ;PADRVGNTAB_0..4

      0-1    SPARE7
      2-7    PADRVGNTAB_4
      8-13   PADRVGNTAB_3
      14-19  PADRVGNTAB_2
      20-25  PADRVGNTAB_1
      26-31  PADRVGNTAB_0

ATH:01C05Ch - PHY_ANALOG_TXRF8 ;PADRVGNTAB_5..9

      0-1    SPARE8
      2-7    PADRVGNTAB_9
      8-13   PADRVGNTAB_8
      14-19  PADRVGNTAB_7
      20-25  PADRVGNTAB_6
      26-31  PADRVGNTAB_5

ATH:01C060h - PHY_ANALOG_TXRF9 ;PADRVGNTAB_10..14

      0-1    SPARE9
      2-7    PADRVGNTAB_14
      8-13   PADRVGNTAB_13
      14-19  PADRVGNTAB_12
      20-25  PADRVGNTAB_11
      26-31  PADRVGNTAB_10

ATH:01C064h - PHY_ANALOG_TXRF10

      0-2    SPARE10
      3      PDOUT5G_3CALTX
      4-6    D3B5GCALTX
      7-9    D4B5GCALTX
      10-16  PADRVGN2GCALTX
      17-19  DB2GCALTX
      20     CALTXSHIFT
      21     CALTXSHIFTOVR
      22-27  PADRVGN2G_SMOUT                (R)
      28-31  PADRVGN_INDEX2G_SMOUT          (R)

ATH:01C068h - PHY_ANALOG_TXRF11

      0-1    SPARE11
      2-4    PWD_IR25MIXDIV5G
      5-7    PWD_IR25PA2G
      8-10   PWD_IR25MIXBIAS2G
      11-13  PWD_IR25MIXDIV2G
      14-16  PWD_ICSPARE
      17-19  PWD_IC25TEMPSEN
      20-22  PWD_IC25PA5G2
      23-25  PWD_IC25PA5G1
      26-28  PWD_IC25MIXBUF5G
      29-31  PWD_IC25PA2G

ATH:01C06Ch - PHY_ANALOG_TXRF12

      0-7    SPARE12_2                      (R)
      8-9    SPARE12_1
      10-13  ATBSEL5G
      14-16  ATBSEL2G
      17-19  PWD_IRSPARE
      20-22  PWD_IR25TEMPSEN
      23-25  PWD_IR25PA5G2
      26-28  PWD_IR25PA5G1
      29-31  PWD_IR25MIXBIAS5G

ATH:01C080h - PHY_ANALOG_SYNTH1

      0-2    SEL_VCMONABUS
      3-5    SEL_VCOABUS
      6      MONITOR_SYNTHLOCKVCOK
      7      MONITOR_VC2LOW
      8      MONITOR_VC2HIGH
      9      MONITOR_FB_DIV2
      10     MONITOR_REF
      11     MONITOR_FB
      12     SEVENBITVCOCAP
      13-15  PWUP_PD
      16     PWD_VCOBUF
      17-18  VCOBUFGAIN
      19-20  VCOREGLEVEL
      21     VCOREGBYPASS
      22     PWUP_LOREF
      23     PWD_LOMIX
      24     PWD_LODIV
      25     PWD_LOBUF5G
      26     PWD_LOBUF2G
      27     PWD_PRESC
      28     PWD_VCO
      29     PWD_VCMON
      30     PWD_CP
      31     PWD_BIAS

ATH:01C084h - PHY_ANALOG_SYNTH2

      0-3    CAPRANGE3
      4-7    CAPRANGE2
      8-11   CAPRANGE1
      12-15  LOOPLEAKCUR_INTN
      16     CPLOWLK_INTN
      17     CPSTEERING_EN_INTN
      18-19  CPBIAS_INTN
      20-22  VC_LOW_REF
      23-25  VC_MID_REF
      26-28  VC_HI_REF
      29-31  VC_CAL_REF

ATH:01C088h - PHY_ANALOG_SYNTH3

      0-5    WAIT_VC_CHECK
      6-11   WAIT_CAL_LIN
      12-17  WAIT_CAL_BIN
      18-23  WAIT_PWRUP
      24-29  WAIT_SHORTR_PWRUP
      30     SEL_CLK_DIV2
      31     DIS_CLK_XTAL

ATH:01C08Ch - PHY_ANALOG_SYNTH4

      0      PS_SINGLE_PULSE
      1      LONGSHIFTSEL
      2-3    LOBUF5GTUNE_OVR
      4      FORCE_LOBUF5GTUNE
      5      PSCOUNT_FBSEL
      6-7    SDM_DITHER1
      8      SDM_MODE
      9      SDM_DISABLE
      10     RESET_PRESC
      11-12  PRESCSEL
      13     PFD_DISABLE
      14     PFDDELAY_FRACN
      15     FORCE_LO_ON
      16     CLKXTAL_EDGE_SEL
      17     VCOCAPPULLUP
      18-25  VCOCAP_OVR
      26     FORCE_VCOCAP
      27     FORCE_PINVC
      28     SHORTR_UNTIL_LOCKED
      29     ALWAYS_SHORTR
      30     DIS_LOSTVC
      31     DIS_LIN_CAPSEARCH

ATH:01C090h - PHY_ANALOG_SYNTH5

      0-1    VCOBIAS
      2-4    PWDB_ICLOBUF5G50
      5-7    PWDB_ICLOBUF2G50
      8-10   PWDB_ICVCO25
      11-13  PWDB_ICVCOREG25
      14     PWDB_IRVCOREG50
      15-17  PWDB_ICLOMIX
      18-20  PWDB_ICLODIV50
      21-23  PWDB_ICPRESC50
      24-26  PWDB_IRVCMON25
      27-29  PWDB_IRPFDCP
      30-31  SDM_DITHER2

ATH:01C094h - PHY_ANALOG_SYNTH6

      0-1    LOBUF5GTUNE                    (R)
      2-8    LOOP_IP                        (R)
      9      VC2LOW                         (R)
      10     VC2HIGH                        (R)
      11     RESET_SDM_B                    (R)
      12     RESET_PSCOUNTERS               (R)
      13     RESET_PFD                      (R)
      14     RESET_RFD                      (R)
      15     SHORT_R                        (R)
      16-23  VCO_CAP_ST                     (R)
      24     PIN_VC                         (R)
      25     SYNTH_LOCK_VC_OK               (R)
      26     CAP_SEARCH                     (R)
      27-30  SYNTH_SM_STATE                 (R)
      31     SYNTH_ON                       (R)

ATH:01C098h - PHY_ANALOG_SYNTH7

      0      OVRCHANDECODER
      1      FORCE_FRACLSB
      2-18   CHANFRAC
      19-27  CHANSEL
      28-29  AMODEREFSEL
      30     FRACMODE
      31     LOADSYNTHCHANNEL

ATH:01C09Ch - PHY_ANALOG_SYNTH8

      0      CPSTEERING_EN_FRACN
      1-7    LOOP_ICPB
      8-11   LOOP_CSB
      12-16  LOOP_RSB
      17-21  LOOP_CPB
      22-26  LOOP_3RD_ORDER_RB
      27-31  REFDIVB

ATH:01C0A0h - PHY_ANALOG_SYNTH9

      0      PFDDELAY_INTN
      1-3    SLOPE_ICPA0
      4-7    LOOP_ICPA0
      8-11   LOOP_CSA0
      12-16  LOOP_RSA0
      17-21  LOOP_CPA0
      22-26  LOOP_3RD_ORDER_RA
      27-31  REFDIVA

ATH:01C0A4h - PHY_ANALOG_SYNTH10

      0-1    SPARE10A
      2-4    PWDB_ICLOBIAS50
      5-7    PWDB_IRSPARE25
      8-10   PWDB_ICSPARE25
      11-13  SLOPE_ICPA1
      14-17  LOOP_ICPA1
      18-21  LOOP_CSA1
      22-26  LOOP_RSA1
      27-31  LOOP_CPA1

ATH:01C0A8h - PHY_ANALOG_SYNTH11

      0-4    SPARE11A
      5      FORCE_LOBUF5G_ON
      6-7    LOREFSEL
      8-9    LOBUF2GTUNE
      10     CPSTEERING_MODE
      11-13  SLOPE_ICPA2
      14-17  LOOP_ICPA2
      18-21  LOOP_CSA2
      22-26  LOOP_RSA2
      27-31  LOOP_CPA2

ATH:01C0ACh - PHY_ANALOG_SYNTH12

      0-9    SPARE12A
      10-13  LOOPLEAKCUR_FRACN
      14     CPLOWLK_FRACN
      15-16  CPBIAS_FRACN
      17     SYNTHDIGOUTEN
      18     STRCONT
      19-22  VREFMUL3
      23-26  VREFMUL2
      27-30  VREFMUL1
      31     CLK_DOUBLER_EN

ATH:01C0B0h - PHY_ANALOG_SYNTH13

      0      SPARE13A
      1-3    SLOPE_ICPA_FRACN
      4-7    LOOP_ICPA_FRACN
      8-11   LOOP_CSA_FRACN
      12-16  LOOP_RSA_FRACN
      17-21  LOOP_CPA_FRACN
      22-26  LOOP_3RD_ORDER_RA_FRACN
      27-31  REFDIVA_FRACN

ATH:01C0B4h - PHY_ANALOG_SYNTH14

      0-1    SPARE14A
      2-3    LOBUF5GTUNE_3
      4-5    LOBUF2GTUNE_3
      6-7    LOBUF5GTUNE_2
      8-9    LOBUF2GTUNE_2
      10     PWD_LOBUF5G_3
      11     PWD_LOBUF2G_3
      12     PWD_LOBUF5G_2
      13     PWD_LOBUF2G_2
      14-16  PWUPLO23_PD
      17-19  PWDB_ICLOBUF5G50_3
      20-22  PWDB_ICLOBUF2G50_3
      23-25  PWDB_ICLOBUF5G50_2
      26-28  PWDB_ICLOBUF2G50_2
      29-31  PWDB_ICLVLSHFT

ATH:01C0C0h - PHY_ANALOG_BIAS1

      0-6    SPARE1
      7-9    PWD_IC25V2IQ
      10-12  PWD_IC25V2II
      13-15  PWD_IC25BB
      16-18  PWD_IC25DAC
      19-21  PWD_IC25FIR
      22-24  PWD_IC25ADC
      25-31  BIAS_SEL

ATH:01C0C4h - PHY_ANALOG_BIAS2

      0-4    SPARE2
      5-7    PWD_IC25XPA
      8-10   PWD_IC25XTAL
      11-13  PWD_IC25TXRF
      14-16  PWD_IC25RXRF
      17-19  PWD_IC25SYNTH
      20-22  PWD_IC25PLLREG
      23-25  PWD_IC25PLLCP2
      26-28  PWD_IC25PLLCP
      29-31  PWD_IC25PLLGM

ATH:01C0C8h - PHY_ANALOG_BIAS3

      0-1    SPARE3
      2-4    PWD_IR25SAR
      5-7    PWD_IR25TXRF
      8-10   PWD_IR25RXRF
      11-13  PWD_IR25SYNTH
      14-16  PWD_IR25PLLREG
      17-19  PWD_IR25BB
      20-22  PWD_IR50DAC
      23-25  PWD_IR25DAC
      26-28  PWD_IR25FIR
      29-31  PWD_IR50ADC

ATH:01C0CCh - PHY_ANALOG_BIAS4

      0-10   SPARE4
      11-13  PWD_IR25SPARED
      14-16  PWD_IR25SPAREC
      17-19  PWD_IR25SPAREB
      20-22  PWD_IR25XPA
      23-25  PWD_IC25SPAREC
      26-28  PWD_IC25SPAREB
      29-31  PWD_IC25SPAREA

ATH:01C100h - PHY_ANALOG_RXTX1

      0      SCFIR_GAIN
      1      MANRXGAIN
      2-5    AGC_DBDAC
      6      OVR_AGC_DBDAC
      7      ENABLE_PAL
      8      ENABLE_PAL_OVR
      9-11   TX1DB_BIQUAD
      12-13  TX6DB_BIQUAD
      14     PADRVHALFGN2G
      15-18  PADRV2GN
      19-22  PADRV3GN5G
      23-26  PADRV4GN5G
      27-30  TXBB_GC
      31     MANTXGAIN

ATH:01C104h - PHY_ANALOG_RXTX2

      0      BMODE
      1      BMODE_OVR
      2      SYNTHON
      3      SYNTHON_OVR
      4-5    BW_ST
      6      BW_ST_OVR
      7      TXON
      8      TXON_OVR
      9      PAON
      10     PAON_OVR
      11     RXON
      12     RXON_OVR
      13     AGCON
      14     AGCON_OVR
      15-17  TXMOD
      18     TXMOD_OVR
      19-21  RX1DB_BIQUAD
      22-23  RX6DB_BIQUAD
      24-25  MXRGAIN
      26-28  VGAGAIN
      29-31  LNAGAIN

ATH:01C108h - PHY_ANALOG_RXTX3

      0-2    SPARE3
      3      SPURON
      4      PAL_LOCKEDEN
      5      DACFULLSCALE
      6      ADCSHORT
      7      DACPWD
      8      DACPWD_OVR
      9      ADCPWD
      10     ADCPWD_OVR
      11-16  AGC_CALDAC
      17     AGC_CAL
      18     AGC_CAL_OVR
      19     LOFORCEDON
      20     CALRESIDUE
      21     CALRESIDUE_OVR
      22     CALFC
      23     CALFC_OVR
      24     CALTX
      25     CALTX_OVR
      26     CALTXSHIFT
      27     CALTXSHIFT_OVR
      28     CALPA
      29     CALPA_OVR
      30     TURBOADC
      31     TURBOADC_OVR

ATH:01C140h - PHY_ANALOG_BB1

      0      I2V_CURR2X
      1      ENABLE_LOQ
      2      FORCE_LOQ
      3      ENABLE_NOTCH
      4      FORCE_NOTCH
      5      ENABLE_BIQUAD
      6      FORCE_BIQUAD
      7      ENABLE_OSDAC
      8      FORCE_OSDAC
      9      ENABLE_V2I
      10     FORCE_V2I
      11     ENABLE_I2V
      12     FORCE_I2V
      13-15  CMSEL
      16-17  ATBSEL
      18     PD_OSDAC_CALTX_CALPA
      19-23  OFSTCORRI2VQ
      24-28  OFSTCORRI2VI
      29     LOCALOFFSET
      30-31  RANGE_OSDAC

ATH:01C144h - PHY_ANALOG_BB2

      0-3    SPARE
      4-7    MXR_HIGHGAINMASK
      8-9    SEL_TEST
      10-14  RCFILTER_CAP
      15     OVERRIDE_RCFILTER_CAP
      16-19  FNOTCH
      20     OVERRIDE_FNOTCH
      21-25  FILTERFC
      26     OVERRIDE_FILTERFC
      27     I2V2RXOUT_EN
      28     BQ2RXOUT_EN
      29     RXIN2I2V_EN
      30     RXIN2BQ_EN
      31     SWITCH_OVERRIDE

ATH:01C148h - PHY_ANALOG_BB3

      0-7    SPARE
      8-15   hw4: SPARE
      8-9    hw6: SEL_OFST_READBK           ;\
      10     hw6: OVERRIDE_RXONLY_FILTERFC  ; hw6.0 only
      11-15  hw6: RXONLY_FILTERFC           ;/
      16-20  FILTERFC                       (R)
      21-25  OFSTCORRI2VQ                   (R)
      26-30  OFSTCORRI2VI                   (R)
      31     EN_TXBBCONSTCUR

ATH:01C280h - PHY_ANALOG_PLLCLKMODA

      0      PWD_PLLSDM
      1      PWDPLL
      2-16   PLLFRAC
      17-20  REFDIV
      21-30  DIV
      31     LOCAL_PLL

ATH:01C284h - PHY_ANALOG_PLLCLKMODA2

      0-3    SPARE
      4      DACPWD
      5      ADCPWD
      6      LOCAL_ADDAC
      7-8    DAC_CLK_SEL
      9-12   ADC_CLK_SEL
      13     LOCAL_CLKMODA
      14     PLLBYPASS
      15     LOCAL_PLLBYPASS
      16-17  PLLATB
      18     PLL_SVREG
      19     HI_FREQ_EN
      20     RST_WARM_INT_L
      21     RST_WARM_OVR
      22-23  PLL_KVCO
      24-26  PLLICP
      27-31  PLLFILTER

ATH:01C288h - PHY_ANALOG_TOP

      0-2    SPARE
      3      PWDBIAS
      4      FLIP_XPABIAS
      5      XPAON2
      6      XPAON5
      7      XPASHORT2GND
      8-11   XPABIASLVL
      12     XPABIAS_EN
      13     ATBSELECT
      14     LOCAL_XPA
      15     XPABIAS_BYPASS
      16     TEST_PADQ_EN
      17     TEST_PADI_EN
      18     TESTIQ_RSEL
      19     TESTIQ_BUFEN
      20     PAD2GND
      21     INTH2PAD
      22     INTH2GND
      23     INT2PAD
      24     INT2GND
      25     PWDPALCLK
      26     INV_CLK320_ADC
      27     FLIP_REFCLK40
      28     FLIP_PLLCLK320
      29     FLIP_PLLCLK160
      30-31  CLK_SEL

ATH:01C28Ch - PHY_ANALOG_THERM

      0-2    LOREG_LVL
      3-5    RFREG_LVL
      6      SAR_ADC_DONE                   (R)
      7-14   SAR_ADC_OUT                    (R)
      15-22  SAR_DACTEST_CODE
      23     SAR_DACTEST_EN
      24     SAR_ADCCAL_EN
      25-26  THERMSEL
      27     SAR_SLOW_EN
      28     THERMSTART
      29     SAR_AUTOPWD_EN
      30     THERMON
      31     LOCAL_THERM

ATH:01C290h - PHY_ANALOG_XTAL

      0-5    SPARE
      6      XTAL_NOTCXODET
      7      LOCALBIAS2X
      8      LOCAL_XTAL
      9      XTAL_PWDCLKIN
      10     XTAL_OSCON
      11     XTAL_PWDCLKD
      12     XTAL_LOCALBIAS
      13     XTAL_SHRTXIN
      14-15  XTAL_DRVSTR
      16-22  XTAL_CAPOUTDAC
      23-29  XTAL_CAPINDAC
      30     XTAL_BIAS2X
      31     TCXODET                        (R)

ATH:01C380h - PHY_ANALOG_RBIST_CNTRL

      0      ATE_TONEGEN_DC_ENABLE
      1      ATE_TONEGEN_TONE0_ENABLE
      2      ATE_TONEGEN_TONE1_ENABLE
      3      ATE_TONEGEN_LFTONE0_ENABLE
      4      ATE_TONEGEN_LINRAMP_ENABLE_I
      5      ATE_TONEGEN_LINRAMP_ENABLE_Q
      6      ATE_TONEGEN_PRBS_ENABLE_I
      7      ATE_TONEGEN_PRBS_ENABLE_Q
      8      ATE_CMAC_DC_WRITE_TO_CANCEL
      9      ATE_CMAC_DC_ENABLE
      10     ATE_CMAC_CORR_ENABLE
      11     ATE_CMAC_POWER_ENABLE
      12     ATE_CMAC_IQ_ENABLE
      13     ATE_CMAC_I2Q2_ENABLE
      14     ATE_CMAC_POWER_HPF_ENABLE
      15     ATE_RXDAC_CALIBRATE
      16     ATE_RBIST_ENABLE
      17     ATE_ADC_CLK_INVERT             ;-newer revision only

ATH:01C384h - PHY_ANALOG_TX_DC_OFFSET

      0-10   ATE_TONEGEN_DC_I
      16-26  ATE_TONEGEN_DC_Q

ATH:01C388h - PHY_ANALOG_TX_TONEGEN0
ATH:01C38Ch - PHY_ANALOG_TX_TONEGEN1
ATH:01C390h - PHY_ANALOG_TX_LFTONEGEN0

      0-6    ATE_TONEGEN_TONE_FREQ
      8-11   ATE_TONEGEN_TONE_A_EXP
      16-23  ATE_TONEGEN_TONE_A_MAN
      24-30  ATE_TONEGEN_TONE_TAU_K

ATH:01C394h - PHY_ANALOG_TX_LINEAR_RAMP_I
ATH:01C398h - PHY_ANALOG_TX_LINEAR_RAMP_Q

      0-10   ATE_TONEGEN_LINRAMP_INIT
      12-21  ATE_TONEGEN_LINRAMP_DWELL
      24-29  ATE_TONEGEN_LINRAMP_STEP

ATH:01C39Ch - PHY_ANALOG_TX_PRBS_MAG

      0-9    ATE_TONEGEN_PRBS_MAGNITUDE_I
      16-25  ATE_TONEGEN_PRBS_MAGNITUDE_Q

ATH:01C3A0h - PHY_ANALOG_TX_PRBS_SEED_I

      0-30   ATE_TONEGEN_PRBS_SEED

ATH:01C3A4h - PHY_ANALOG_TX_PRBS_SEED_Q

      0-30   ATE_TONEGEN_PRBS_SEED

ATH:01C3A8h - PHY_ANALOG_CMAC_DC_CANCEL

      0-9    ATE_CMAC_DC_CANCEL_I
      16-25  ATE_CMAC_DC_CANCEL_Q

ATH:01C3ACh - PHY_ANALOG_CMAC_DC_OFFSET

      0-3    ATE_CMAC_DC_CYCLES

ATH:01C3B0h - PHY_ANALOG_CMAC_CORR

      0-4    ATE_CMAC_CORR_CYCLES
      8-13   ATE_CMAC_CORR_FREQ

ATH:01C3B4h - PHY_ANALOG_CMAC_POWER

      0-3    ATE_CMAC_POWER_CYCLES

ATH:01C3B8h - PHY_ANALOG_CMAC_CROSS_CORR

      0-3    ATE_CMAC_IQ_CYCLES

ATH:01C3BCh - PHY_ANALOG_CMAC_I2Q2

      0-3    ATE_CMAC_I2Q2_CYCLES

ATH:01C3C0h - PHY_ANALOG_CMAC_POWER_HPF

      0-3    ATE_CMAC_POWER_HPF_CYCLES
      4-7    ATE_CMAC_POWER_HPF_WAIT

ATH:01C3C4h - PHY_ANALOG_RXDAC_SET1

      0-1    ATE_RXDAC_MUX
      4      ATE_RXDAC_HI_GAIN
      8-13   ATE_RXDAC_CAL_WAIT
      16-19  ATE_RXDAC_CAL_MEASURE_TIME

ATH:01C3C8h - PHY_ANALOG_RXDAC_SET2

      0-4    ATE_RXDAC_I_HI
      8-12   ATE_RXDAC_Q_HI
      16-20  ATE_RXDAC_I_LOW
      24-28  ATE_RXDAC_Q_LOW

ATH:01C3CCh - PHY_ANALOG_RXDAC_LONG_SHIFT

      0-4    ATE_RXDAC_I_STATIC
      8-12   ATE_RXDAC_Q_STATIC

ATH:01C3D0h - PHY_ANALOG_CMAC_RESULTS_I

      0-31   ATE_CMAC_RESULTS

ATH:01C3D4h - PHY_ANALOG_CMAC_RESULTS_Q

      0-31   ATE_CMAC_RESULTS

ATH:01C740h - PHY_ANALOG_PMU1
This register differs in hw4/hw6 (in hw6, bits are renumbered, new OVERRIDE bits are added, and the SREG_LVLCTR bit is removed):

      hw4    hw6    name
      0-10   0-3    SPARE                         ;-unused
      11     4      OTP_V25_PWD                   ;-OTP V25
      12     5      PAREGON_MAN                   ;\PA REG
      -      6      PAREGON_OVERRIDE_EN           ;/
      13     7      OTPREGON_MAN                  ;\OTP REG
      -      8      OTPREGON_OVERRIDE_EN          ;/
      14     9      DREGON_MAN                    ;\DREG
      -      10     DREGON_OVERRIDE_EN            ;/
      15     11     DISCONTMODEEN                 ;\DISCONT MODE
      -      12     SWREGDISCONT_OVERRIDE_EN      ;/
      16     13     SWREGON_MAN                   ;\
      -      14     SWREGON_OVERRIDE_EN           ;
      17-18  15-16  SWREG_FREQCUR                 ;
      19-21  17-19  SWREG_FREQCAP                 ; SW REG
      -      20     SWREGFREQ_OVERRIDE_EN         ;
      22-23  21-22  SWREG_LVLCTR                  ;
      -      23     SWREGLVL_OVERRIDE_EN          ;/
      24-25  -      hw4:SREG_LVLCTR               ;-SREG  ;<---- removed in hw6 (!)
      26-27  24-25  DREG_LVLCTR                   ;\DREG
      -      26     DREGLVL_OVERRIDE_EN           ;/
      28     27     PAREG_XPNP                    ;\
      29-31  28-30  PAREG_LVLCTR                  ; PA REG
      -      31     PAREGLVL_OVERRIDE_EN          ;/

ATH:01C744h - PHY_ANALOG_PMU2

      0-7    SPARE
      8      VBATT_1_3TOATB
      9      VBATT_1_2TOATB
      10     VBATT_2_3TOATB
      11     PWD_BANDGAP_MAN
      12     PWD_LFO_MAN
      13     VBATT_LT_3P2
      14     VBATT_LT_2P8
      15     VBATT_GT_4P2
      16     hw4: PMU_MAN_OVERRIDE_EN               ;\changed/renamed in hw4/hw6
      16     hw6: PMU_XPNP_OVERRIDE_EN              ;/
      17-18  VBATT_GT_LVLCTR
      19     SWREGVSSL2ATB
      20-21  SWREGVSSL_LVLCTR
      22     SWREGVDDH2ATB
      23-24  SWREGVDDH_LVLCTR
      25-27  SWREG2ATB
      28     OTPREG2ATB
      29-30  OTPREG_LVLCTR
      31     hw4: DREG_LVLCTR_MANOVR_EN             ;\changed/renamed in hw4/hw6
      31     hw6: OTPREG_LVLCTR_MANOVR_EN           ;/

DSi Atheros Wifi - Internal I/O - 020000h - WMAC DMA (hw4/hw6)

ATH:020008h - MAC_DMA_CR - MAC Control Register

      0-1    -
      2      hw4: Receive enable (RXE)            (R)       ;\one bit in hw4,
      2      hw6: Receive LP enable (RXE_LP)      (R)       ; two bits in hw6
      3      hw6: Receive HP enable (RXE_HP)      (R)       ;/
      4      -
      5      Receive disable (RXD)
      6      One-shot software interrupt (SWI)    (R)

ATH:02000Ch - MAC_DMA_RXDP - MAC receive queue descriptor pointer ;hw4 only

      ..     Pointer                           <------------ HW4 ONLY

ATH:020014h - MAC_DMA_CFG - MAC configuration and status register

      0      Byteswap TX descriptor words (BE_MODE_XMIT_DESC)
      1      Byteswap TX data buffer words (BE_MODE_XMIT_DATA)
      2      Byteswap RX descriptor words (BE_MODE_RCV_DESC)
      3      Byteswap RX data buffer words (BE_MODE_RCV_DATA)
      4      Byteswap register access data words (BE_MODE_MMR)
      5      AP/adhoc indication (ADHOC) (0=AP, 1=Adhoc)
      6-7    -
      8      PHY OK status (PHY_OK)                    (R)
      9      hw6: EEPROM_BUSY                          (R)  ;-hw6 only
      10     Clock gating disable (CLKGATE_DIS)
      11     hw6: HALT_REQ                                  ;\
      12     hw6: HALT_ACK                             (R)  ;
      13-16  -                                              ;
      17-18  hw6: REQ_Q_FULL_THRESHOLD                      ; hw6 only
      19     hw6: MISSING_TX_INTR_FIX_ENABLE                ;
      20     hw6: LEGACY_INT_MIT_MODE_ENABLE                ;
      21     hw6: RESET_INT_MIT_CNTRS                       ;/

ATH:020018h - MAC_DMA_RXBUFPTR_THRESH ;hw6 only

      0-3    hw6: HP_DATA                                   ;\hw6 only
      8-14   hw6: LP_DATA                                   ;/

ATH:02001Ch - MAC_DMA_TXDPPTR_THRESH ;hw6 only

      0-3    DATA                                           ;-hw6 only

ATH:020020h - MAC_DMA_MIRT - Maximum rate threshold register

      0-15   Threshold (RATE_THRESH)

ATH:020024h - MAC_DMA_IER aka MAC_DMA_GLOBAL_IER - MAC Interrupt enable

      0      Global interrupt enable (0=Disable, 1=Enable)

ATH:020028h - MAC_DMA_TIMT_0 - Transmit Interrupt Mitigation Threshold
ATH:02002Ch - MAC_DMA_RIMT - Receive Interrupt Mitigation Threshold

      0-15   Last packet threshold (LAST_PKT_THRESH)
      16-31  First packet threshold (FIRST_PKT_THRESH)

ATH:020030h - MAC_DMA_TXCFG - MAC Transmit DMA size config register
In hw4, most bits are left undefined, however, hw4 DOES refer to the register as "MAC tx DMA size config", so one may assume that at least the SIZE value in bit0-2 does exist in hw4, too.

      0-2    hw6: DMA_SIZE (maybe as in RXCFG below?)       ;-hw6 only (???)
      3      -
      4-9    Frame trigger level (TRIGLVL)
      10     hw6: JUMBO_EN                                  ;-hw6 only (??)
      11     ADHOC_BEACON_ATIM_TX_POLICY (hw6name: BCN_PAST_ATIM_DIS)
      12     hw6: ATIM_DEFER_DIS                            ;\
      13     -                                              ;
      14     hw6: RTCI_DIS                                  ; hw6 only (?)
      15-16  -                                              ;
      17     hw6: DIS_RETRY_UNDERRUN                        ;
      18     hw6: DIS_CW_INC_QUIET_COLL                     ;
      19     hw6: RTS_FAIL_EXCESSIVE_RETRIES                ;/

Blurb...

      MAC_DMA_FTRIG_IMMED = 0x00000000 ;bytes in PCU TX FIFO before air
      MAC_DMA_FTRIG_64B   = 0x00000010 ;default
      MAC_DMA_FTRIG_128B  = 0x00000020
      MAC_DMA_FTRIG_192B  = 0x00000030
      MAC_DMA_FTRIG_256B  = 0x00000040 ;5 bits total

ATH:020034h - MAC_DMA_RXCFG - MAC rx DMA size config register

      0-2    DMA Size (0..7 = 4,8,16,32,64,128,256,512 bytes)
      3-4    hw6: ZERO_LEN_DMA_EN                           ;-hw6: two bits?
      4      hw4: Enable DMA of zero-length frame           ;-hw4: one bit?
      5      hw6: JUMBO_EN                                  ;\
      6      hw6: JUMBO_WRAP_EN                             ; hw6 only (?)
      7      hw6: SLEEP_RX_PEND_EN                          ;/

Blurb...

      MAC_DMA_RXCFG_DMASIZE_4B   = 0x00000000 ;DMA size 4 bytes (TXCFG + RXCFG)
      MAC_DMA_RXCFG_DMASIZE_8B   = 0x00000001 ;DMA size 8 bytes
      MAC_DMA_RXCFG_DMASIZE_16B  = 0x00000002 ;DMA size 16 bytes
      MAC_DMA_RXCFG_DMASIZE_32B  = 0x00000003 ;DMA size 32 bytes
      MAC_DMA_RXCFG_DMASIZE_64B  = 0x00000004 ;DMA size 64 bytes
      MAC_DMA_RXCFG_DMASIZE_128B = 0x00000005 ;DMA size 128 bytes
      MAC_DMA_RXCFG_DMASIZE_256B = 0x00000006 ;DMA size 256 bytes
      MAC_DMA_RXCFG_DMASIZE_512B = 0x00000007 ;DMA size 512 bytes

ATH:020038h - MAC_DMA_RXJLA (R) ;hw6 only

      31-2   DATA                                       (R) ;-hw6 only

ATH:020040h - MAC_DMA_MIBC - MAC MIB control register

      0     counter overflow warning (WARNING)          (R)
      1     freeze MIB counters (FREEZE)
      2     clear MIB counters (CLEAR)
      3     MIB counter strobe, increment all (STROBE)  (R)

ATH:020044h - MAC_DMA_TOPS - MAC timeout prescale count

      0-15  Timeout prescale (TIMEOUT)

ATH:020048h - MAC_DMA_RXNPTO - MAC no frame received timeout

      0-9   No frame received timeout (TIMEOUT)

ATH:02004Ch - MAC_DMA_TXNPTO - MAC no frame trasmitted timeout

      0-9   No frame transmitted timeout (TIMEOUT)
      10-19 QCU Mask (QCU 0-9)  ;QCU's for which frame completions will cause
              a reset of the no frame xmit'd timeout

ATH:020050h - MAC_DMA_RPGTO - MAC receive frame gap timeout

      0-9   Receive frame gap timeout (TIMEOUT)

ATH:020054h - MAC_DMA_RPCNT - MAC receive frame count limit ;hw4 only

      0-4   Receive frame count limit                       ;-hw4 only

ATH:020058h - MAC_DMA_MACMISC - MAC miscellaneous control/status register

      4      hw6: FORCE_PCI_EXT                             ;-hw6 only
      5-8    DMA observation bus mux select (DMA_OBS_MUXSEL)
      9-11   MISC observation bus mux select (MISC_OBS_MUXSEL)
      12-14  MAC observation bus mux select (lsb) (MISC_F2_OBS_LOW_MUXSEL)
      15-17  MAC observation bus mux select (msb) (MISC_F2_OBS_HIGH_MUXSEL)

     ____________ below in hw6 only ____________

ATH:02005Ch - MAC_DMA_INTER ;hw6 only

      0      REQ
      1-2    MSI_RX_SRC
      3-4    MSI_TX_SRC

ATH:020060h - MAC_DMA_DATABUF ;hw6 only

      0-11   LEN

ATH:020064h - MAC_DMA_GTT ;hw6 only
ATH:02006Ch - MAC_DMA_CST ;hw6 only

      0-15   COUNT
      16-31  LIMIT

ATH:020068h - MAC_DMA_GTTM ;hw6 only

      0      USEC_STROBE
      1      IGNORE_CHAN_IDLE
      2      RESET_ON_CHAN_IDLE
      3      CST_USEC_STROBE
      4      DISABLE_QCU_FR_ACTIVE_GTT
      5      DISABLE_QCU_FR_ACTIVE_BT

ATH:020070h - MAC_DMA_RXDP_SIZE ;hw6 only

      0-7    LP                             (R)
      8-12   HP                             (R)

ATH:020074h - MAC_DMA_RX_QUEUE_HP_RXDP ;hw6 only
ATH:020078h - MAC_DMA_RX_QUEUE_LP_RXDP ;hw6 only

      0-31   ADDR

ATH:0200E0h - MAC_DMA_DMADBG_0 (R) - hw6 only
ATH:0200E4h - MAC_DMA_DMADBG_1 (R) - hw6 only
ATH:0200E8h - MAC_DMA_DMADBG_2 (R) - hw6 only
ATH:0200ECh - MAC_DMA_DMADBG_3 (R) - hw6 only
ATH:0200F0h - MAC_DMA_DMADBG_4 (R) - hw6 only
ATH:0200F4h - MAC_DMA_DMADBG_5 (R) - hw6 only
ATH:0200F8h - MAC_DMA_DMADBG_6 (R) - hw6 only
ATH:0200FCh - MAC_DMA_DMADBG_7 (R) - hw6 only

      0-31   DATA                                      (R)  ;-hw6 only

ATH:020100h - MAC_DMA_QCU_TXDP_REMAINING_QCU_7_0 (R) ;hw6 only
ATH:020104h - MAC_DMA_QCU_TXDP_REMAINING_QCU_9_8 (R) ;hw6 only

      0-39   For QCU 0-9 (4bits each)                  (R)  ;\hw6 only
      40-63  -                                              ;/

(see above) - MAC_DMA_TIMT_0 - hw4/hw6
ATH:020108h - MAC_DMA_TIMT_1 - hw6 only
ATH:02010Ch - MAC_DMA_TIMT_2 - hw6 only
ATH:020110h - MAC_DMA_TIMT_3 - hw6 only
ATH:020114h - MAC_DMA_TIMT_4 - hw6 only
ATH:020118h - MAC_DMA_TIMT_5 - hw6 only
ATH:02011Ch - MAC_DMA_TIMT_6 - hw6 only
ATH:020120h - MAC_DMA_TIMT_7 - hw6 only
ATH:020124h - MAC_DMA_TIMT_8 - hw6 only
ATH:020128h - MAC_DMA_TIMT_9 - hw6 only

      0-15   LAST_PKT_THRESH
      16-31  FIRST_PKT_THRESH

ATH:02012Ch - MAC_DMA_CHKACC - hw6 only

      0      CHKSUM_SEL

DSi Atheros Wifi - Internal I/O - 020080h - WMAC IRQ Interrupt (hw4/hw6)

ATH:020080h - MAC_DMA_ISR(_P) - MAC Primary interrupt status register
ATH:0200A0h - MAC_DMA_IMR(_P) - MAC Primary interrupt mask register
ATH:0200C0h - MAC_DMA_ISR(_P)_RAC - MAC Primary interrupt read-and-clear
Interrupt Status Registers
Only the bits in the ISR_P register and the IMR_P registers control whether the MAC's INTA# output is asserted. The bits in the secondary interrupt status/mask registers control what bits are set in the primary interrupt status register; however the IMR_S* registers DO NOT determine whether INTA# is asserted. That is INTA# is asserted only when the logical AND of ISR_P and IMR_P is non-zero. The secondary interrupt mask/status registers affect what bits are set in ISR_P but they do not directly affect whether INTA# is asserted.
Interrupt Mask Registers
Only the bits in the IMR control whether the MAC's INTA# output will be asserted. The bits in the secondary interrupt mask registers control what bits get set in the primary interrupt status register; however the IMR_S* registers DO NOT determine whether INTA# is asserted.
Read-and-Clear Registers
The read-and-clear registers are read-only (R) "shadow copies" of the interrupt status registers, with read-and-clear access.

      0     At least one frame received sans errors  ;\
      1     Receive interrupt request                ;
      2     Receive error interrupt                  ; RX
      3     No frame received within timeout clock   ;
      4     Received descriptor empty interrupt      ;
      5     Receive FIFO overrun interrupt           ;/
      6     Transmit okay interrupt                  ;\       ;<-- ISR_S0.Bit0..9
      7     Transmit interrupt request               ;
      8     Transmit error interrupt                 ; TX     ;<-- ISR_S1.Bit0..9
      9     No frame transmitted interrupt           ;
      10    Transmit descriptor empty interrupt      ;
      11    Transmit FIFO underrun interrupt         ;/       ;<-- ISR_S2.Bit0..9
      12    MIB interrupt - see MIBC
      13    Software interrupt
      14    PHY receive error interrupt
      15    Key-cache miss interrupt
      16    Beacon rssi high threshold interrupt  ;aka Beacon rssi hi threshold
      17    Beacon threshold interrupt            ;aka Beacon rssi lo threshold
      18    Beacon missed interrupt
      19    Maximum transmit interrupt rate
      20    Beacon not ready interrupt            ;aka BNR interrupt
      21    An unexpected bus error has occurred
      22    -
      23    Beacon Misc (TIM, CABEND, DTIMSYNC, BCNTO)        ;<-- ISR_S2.Bit24..27
      24    Maximum receive interrupt rate
      25    QCU CBR overflow interrupt                        ;<-- ISR_S3.Bit0..9
      26    QCU CBR underrun interrupt                        ;<-- ISR_S3.Bit16..27
      27    QCU scheduling trigger interrupt                  ;<-- ISR_S4.Bit0..9
      28    GENTMR interrupt (aka GENERIC_TIMERS... and/or ISR_S5?)
      29    HCFTO interrupt
      30    Transmit completion mitigation interrupt
      31    Receive completion mitigation interrupt

ATH:020084h - MAC_DMA_ISR_S0 - MAC Secondary Interrupt 0 Stat TX OK/DESC
ATH:0200A4h - MAC_DMA_IMR_S0 - MAC Secondary Interrupt 0 Mask TX OK/DESC
ATH:0200C4h - MAC_DMA_ISR_S0_S - MAC Secondary Interrupt 0 Read-and-Clear

      0-9   TXOK (QCU 0-9)                                   ;--> Primary_ISR.Bit6
      16-27 TXDESC (QCU 0-9)                                 ;--> Primary_ISR. ??

ATH:020088h - MAC_DMA_ISR_S1 - MAC Secondary Interrupt 1 Stat TX ERR/EOL
ATH:0200A8h - MAC_DMA_IMR_S1 - MAC Secondary Interrupt 1 Mask TX ERR/EOL
ATH:0200C8h - MAC_DMA_ISR_S1_S - MAC Secondary Interrupt 1 Read-and-Clear

      0-9   TXERR (QCU 0-9)                                  ;--> Primary_ISR.Bit8
      16-27 TXEOL (QCU 0-9)

ATH:02008Ch - MAC_DMA_ISR_S2 - MAC Secondary Interrupt 2 Stat TX URN/MISC
ATH:0200ACh - MAC_DMA_IMR_S2 - MAC Secondary Interrupt 2 Mask TX URN/MISC
ATH:0200CCh (hw6:000200D0h?) - MAC_DMA_ISR_S2_S - MAC .. 2 Read-and-Clear

      0-9   TXURN (QCU 0-9)                                  ;--> Primary_ISR.Bit11
      10    -
      11    RX_INT                  ;RX
      12    WL_STOMPED
      13    RX_PTR_BAD              ;RX
      14    BT_LOW_PRIORITY_RISING
      15    BT_LOW_PRIORITY_FALLING
      16    BB_PANIC_IRQ
      17    BT_STOMPED
      18    BT_ACTIVE_RISING
      19    BT_ACTIVE_FALLING
      20    BT_PRIORITY_RISING
      21    BT_PRIORITY_FALLING
      22    CST
      23    GTT
      24    TIM                                 ;\
      25    CABEND                              ; Beacon Misc --> Primary_ISR.Bit23
      26    DTIMSYNC                            ;
      27    BCNTO                               ;/
      28    CABTO
      29    DTIM
      30    TSFOOR
      31    -

ATH:020090h - MAC_DMA_ISR_S3 - MAC Secondary Interrupt 3 Stat QCBR OVF/URN
ATH:0200B0h - MAC_DMA_IMR_S3 - MAC Secondary Interrupt 3 Mask QCBR OVF/URN
ATH:0200D0h (hw6:000200D4h?) - MAC_DMA_ISR_S3_S - MAC .. 3 Read-and-Clear

      0-9   QCBROVF (QCU 0-9)                                ;--> Primary_ISR.Bit25
      16-27 QCBRURN (QCU 0-9)                                ;--> Primary_ISR.Bit26

ATH:020094h - MAC_DMA_ISR_S4 - MAC Secondary Interrupt 4 Stat QTRIG
ATH:0200B4h - MAC_DMA_IMR_S4 - MAC Secondary Interrupt 4 Mask QTRIG
ATH:0200D4h (hw6:000200D8h?) - MAC_DMA_ISR_S4_S - MAC .. 4 Read-and-Clear

      0-9   QTRIG (QCU 0-9)                                  ;--> Primary_ISR.Bit27

ATH:020098h - MAC_DMA_ISR_S5 - MAC Secondary Interrupt 5 Stat TIMERS
ATH:0200B8h - MAC_DMA_IMR_S5 - MAC Secondary Interrupt 5 Mask TIMERS
ATH:0200D8h (hw6:000200DCh?) - MAC_DMA_ISR_S5_S - MAC .. 5 Read-and-Clear

      0     TBTT_TIMER_TRIGGER              ;-TBTT timer
      1     DBA_TIMER_TRIGGER               ;\
      2     SBA_TIMER_TRIGGER               ;
      3     HCF_TIMER_TRIGGER               ;
      4     TIM_TIMER_TRIGGER               ; timer's
      5     DTIM_TIMER_TRIGGER              ;
      6     QUIET_TIMER_TRIGGER             ;
      7     NDP_TIMER_TRIGGER               ;
      8-15  GENERIC_TIMER2_TRIGGER          ;/
      16    TIMER_OVERFLOW                  ;<-- which timer overflow ?
      17    DBA_TIMER_THRESHOLD             ;\
      18    SBA_TIMER_THRESHOLD             ;
      19    HCF_TIMER_THRESHOLD             ;
      20    TIM_TIMER_THRESHOLD             ; threshold's
      21    DTIM_TIMER_THRESHOLD            ;
      22    QUIET_TIMER_THRESHOLD           ;
      23    NDP_TIMER_THRESHOLD             ;
      24-31 GENERIC_TIMER2_THRESHOLD        ;/

ATH:02009Ch - MAC_DMA_ISR_S6 - hw6 only ;Interrupt 6 Stat UNKNOWN(?)
ATH:0200BCh - MAC_DMA_IMR_S6 - hw6 only ;Interrupt 6 Mask UNKNOWN(?)
ATH:0200CCh (hw6:really?) - MAC_DMA_ISR_S6_S (R) shadow - hw6 only

      0-31   ?? (probably related to the new "hw6" registers in MAC DMA chapter)

Note: According to hw6.0 source code, "S6_S" has been accidently inserted between "S1_S" and "S2_S" (thus smashing the old hw4-style port numbering for "S2_S thru S5_S") (not checked if that's a source code bug, or if it's actually implemented as so in real hardware).
The hw6.0 source code leaves ALL primary and secondary IRQ bits undocumented, thw above descriptions are based on hw4 (but hw6 might have some added/changed bits here and there).

DSi Atheros Wifi - Internal I/O - 020800h - WMAC QCU Queue (hw4/hw6)

ATH:020800h..020824h - MAC_QCU_TXDP[0..9] aka MAC_DMA_Q(0..9)_TXDP

      0-31   DATA  ...   unspecified     ;MAC Transmit Queue descriptor pointer

ATH:020840h - MAC_QCU_TXE aka MAC_DMA_Q_TXE - MAC Transmit Queue enable (R)
ATH:020880h - MAC_QCU_TXD aka MAC_DMA_Q_TXD - MAC Transmit Queue disable

      0-9    DATA

ATH:0208C0h..0208E4h - MAC_QCU_CBR[0..9] aka MAC_DMA_Q(0..9)_CBRCFG

      0-23  CBR interval (us)      (INTERVAL)       ;\MAC CBR configuration
      24-31 CBR overflow threshold (OVF_THRESH)     ;/

ATH:020900h..020924h - MAC_QCU_RDYTIME[0..9] aka MAC_DMA_Q(0..9)_RDYTIMECFG

      0-23  CBR interval (us)      (DURATION)       ;\MAC ReadyTime configuration
      24    CBR enable             (EN)             ;/

ATH:020940h - MAC_QCU_ONESHOT_ARM_SC aka MAC_DMA_Q_ONESHOTMAC_DMAM_SC - Set
ATH:020980h - MAC_QCU_ONESHOT_ARM_CC aka MAC_DMA_Q_ONESHOTMAC_DMAM_CC - Clr
MAC OneShotArm set/clear control

      0-9    SET/CLEAR

ATH:0209C0h..0209E4h - MAC_QCU_MISC[0..9] aka MAC_DMA_Q(0..9)_MISC
MAC Miscellaneous QCU settings

      0-3   Frame Scheduling Policy mask (FSP):
              0=ASAP                    ;\
              1=CBR                     ; defined as so for
              2=DMA Beacon Alert gated  ; hw4 (maybe same
              3=TIM gated               ; for hw6)
              4=Beacon-sent-gated       ;/
      4     OneShot enable (ONESHOT_EN)
      5     CBR expired counter disable incr (NOFR, empty q)
      6     CBR expired counter disable incr (NOBCNFR, empty beacon q)
      7     Beacon use indication (IS_BCN)
      8     CBR expired counter limit enable (CBR_EXP_INC_LIMIT)
      9     Enable TXE cleared on ReadyTime expired or VEOL (TXE_CLR_ON_CBR_END)
      10    CBR expired counter reset (MMR_CBR_EXP_CNT_CLR_EN)
      11    FR_ABORT_REQ_EN         DCU frame early termination request control

ATH:020A00h..020A24h - MAC_QCU_CNT[0..9] aka MAC_DMA_Q(0..9)_STS

      0-1    FR_PEND: Pending Frame Count (R)        ;\MAC Misc QCU status/counter
      8-15   CBR_EXP: CBR expired counter (R)        ;/

ATH:020A40h - MAC_QCU_RDYTIME_SHDN aka MAC_DMA_Q_RDYTIMESHDN

      0-9    SHUTDOWN: MAC ReadyTimeShutdown status (flags for QCU 0-9 ?)

     _____________ below in hw6 only _____________

ATH:020830h - MAC_QCU_STATUS_RING_START ;hw6 only

      0-31   ADDR

ATH:020834h - MAC_QCU_STATUS_RING_END ;hw6 only

      0-31   ADDR

ATH:020838h - MAC_QCU_STATUS_RING_CURRENT (R) ;hw6 only

      0-31   ADDRESS                        (R)

ATH:020A44h - MAC_QCU_DESC_CRC_CHK ;hw6 only

      0      EN

ATH:020A48h - MAC_QCU_EOL ;hw6 only

      0-9    DUR_CAL_EN

DSi Atheros Wifi - Internal I/O - 021000h - WMAC DCU (hw4/hw6)

ATH:021000h..021024h - MAC_DCU_QCUMASK[0..9] aka MAC_DMA_D(0..9)_QCUMASK
The "DCU_QCU" Mask is some two-dimensional array: An array of ten DCU registers, each containing an array of ten QCU bits.

      0-9   QCU Mask (QCU 0-9)

ATH:021030h - MAC_DCU_GBL_IFS_SIFS aka MAC_DMA_D_GBL_IFS_SIFS

      0-15   DURATION                       ;-DCU global SIFS settings

ATH:021040h..021064h - MAC_DCU_LCL_IFS[0..9] aka MAC_DMA_D(0..9)_LCL_IFS

      0-9    CW_MIN                                 ;\
      10-19  CW_MAX                                 ; MAC DCU-specific IFS settings
      20-27  AIFS                                   ;
      28     hw6: LONG_AIFS     ;-hw6 only          ;
      29-31  -                                      ;/

Note: Even though this field is 8 bits wide the maximum supported AIFS value is FCh. Setting the AIFS value to FDh,FEh,FFh will not work correctly and will cause the DCU to hang (said to be so; at least for hw4).
ATH:021070h - MAC_DCU_GBL_IFS_SLOT aka MAC_DMA_D_GBL_IFS_SLOT

      0-15   DURATION       ;DC global slot interval

ATH:021080h..0210A4h - MAC_DCU_RETRY_LIMIT[0..9] aka MAC_DMA_D(0..9)_RETR..

      0-3   frame RTS failure limit (FRFL)          ;\
      4-7   -                                       ; MAC Retry limits
      8-13  station RTS failure limit (SRFL)        ;
      14-19 station short retry limit (SDFL)        ;
      20-31 -                                       ;/

ATH:0210B0h - MAC_DCU_GBL_IFS_EIFS aka MAC_DMA_D_GBL_IFS_EIFS

      0-15   DURATION                               ;-DCU global EIFS setting

ATH:0210C0h..0210E4h - MAC_DCU_CHANNEL_TIME[0..9] aka MAC_DMA_D(0..9)_CH..

      0-15  ChannelTime duration (us) (DURATION)    ;\MAC ChannelTime settings
      16    ChannelTime enable        (ENABLE)      ;/

ATH:0210F0h - MAC_DCU_GBL_IFS_MISC aka MAC_DMA_D_GBL_IFS_MISC

      0-2    LFSR slice select (LFSR_SLICE_SEL)       ;\
      3      Turbo mode indication (TURBO_MODE)       ;
      4-9    hw6: SIFS_DUR_USEC           ;-hw6 only  ;
      10-19  -                                        ;
      20-21  DCU arbiter delay (ARB_DLY)              ; DCU global misc.
      22     hw6: SIFS_RST_UNCOND         ;\          ; IFS settings
      23     hw6: AIFS_RST_UNCOND         ;           ;
      24     hw6: LFSR_SLICE_RANDOM_DIS   ; hw6 only  ;
      25-26  hw6: CHAN_SLOT_WIN_DUR       ;           ;
      27     hw6: CHAN_SLOT_ALWAYS        ;/          ;
      28     IGNORE_BACKOFF                           ;
      29     hw6: SLOT_COUNT_RST_UNCOND   ;-hw6 only  ;
      30-31  -                                        ;/

ATH:021100h..021124h - MAC_DCU_MISC[0..9] aka MAC_DMA_D(0..9)_MISC

      0-5    BKOFF_THRESH                   ;\
      6      SFC_RST_AT_TS_END_EN           ;
      7      CW_RST_AT_TS_END_DIS           ;
      8      FRAG_BURST_WAIT_QCU_EN         ;
      9      FRAG_BURST_BKOFF_EN            ; MAC Miscellaneous
      10     -                              ; DCU-specific settings
      11     HCF_POLL_EN                    ;
      12     BKOFF_PF                       ; (specified as so for hw6)
      13     -                              ; (hw4 bit numbers are undocumented,
      14-15  VIRT_COLL_POLICY               ; although... actually the SAME bits
      16     IS_BCN                         ; ARE documented, but for the "EOL"
      17     ARB_LOCKOUT_IF_EN              ; registers instead of for "MISC"...?)
      18     LOCKOUT_GBL_EN                 ;
      19     LOCKOUT_IGNORE                 ;
      20     SEQNUM_FREEZE                  ;
      21     POST_BKOFF_SKIP                ;
      22     VIRT_COLL_CW_INC_EN            ;
      23     RETRY_ON_BLOWN_IFS_EN          ;
      24     SIFS_BURST_CHAN_BUSY_IGNORE    ;
      25-31  -                              ;/

ATH:021140h - MAC_DCU_SEQ aka MAC_DMA_D_SEQNUM - MAC Frame sequence number

      0-31   NUM

BUG: The original hw4 header file used sorted addresses, but it's been having 00021140h placed between 000211A4h and 00021230h... either it's just mis-sorted, or the address is mis-spelled? Probably just mis-sorted, because hw6 does confirm the address.
ATH:021270h - MAC_DCU_PAUSE aka MAC_DMA_D_TXPSE

      0-9    REQUEST                      ;\DCU transmit pause control/status
      16     STATUS               (R)     ;/

     _____________ below in hw4 only _____________

ATH:021230h - MAC_DMA_D_FPCTL - DCU frame prefetch settings - hw4 only?

      ...   unspecified

ATH:021180h..021xx4h - MAC_DMA_D(0..9)_EOL - hw4 only (removed in hw6)
;BUG: entry D(8..9) are officially at 21200h..21204h ;\which is implemented
;BUG: entry D(8..9) are *intended* at 211A0h..211A4h ;/in actual hardware?
;BUG: below bits are probably meant to be "MISC" (not "EOL") ?

      0-5   Backoff threshold
      6     End of transmission series station RTS/data failure count reset policy
      7     End of transmission series CW reset policy
      8     Fragment Starvation Policy
      9     Backoff during a frag burst
      10    -
      11    HFC poll enable
      12    Backoff persistence factor setting
      13
      14-15 Mask for Virtual collision handling policy
              (0=Normal, 1=Ignore, 2..3=Unspecified)
      16    Beacon use indication
      17-18 Mask for DCU arbiter lockout control
              (0=No Lockout, 1=Intra-frame, 2=Global, 3=Unspecified)
      19    DCU arbiter lockout ignore control
      20    Sequence number increment disable
      21    Post-frame backoff disable
      22    Virtual coll. handling policy
      23    Blown IFS handling policy
      24-31 -

BUG: The official source code assigns incorrect "BCD-style" values to MAC_DMA_D8_EOL and MAC_DMA_D9_EOL, the source code does also have a MAC_DMA_DEOL_ADDRESS(i) macro function; that function would work okay even with i=8..9.

     _____________ below in hw6 only _____________

ATH:0212B0h - MAC_DCU_WOW_KACFG - hw6 only

      0      TX_EN
      1      TIM_EN
      4-11   BCN_CNT
      12-23  RX_TIMEOUT_CNT

ATH:0212F0h - MAC_DCU_TXSLOT - hw6 only

      0-15   MASK

ATH:02143Ch - MAC_DCU_TXFILTER_CLEAR - hw6 only

      0-31   DATA

ATH:02147Ch - MAC_DCU_TXFILTER_SET - hw6 only

      0-31   DATA

ATH:021038h - MAC_DCU_TXFILTER_DCU0_31_0 - hw6 only
ATH:021078h - MAC_DCU_TXFILTER_DCU0_63_32 - hw6 only
ATH:0210B8h - MAC_DCU_TXFILTER_DCU0_95_64 - hw6 only
ATH:0210F8h - MAC_DCU_TXFILTER_DCU0_127_96 - hw6 only

      0-31   DATA

ATH:02103Ch - MAC_DCU_TXFILTER_DCU8_31_0 - hw6 only (R)
ATH:02107Ch - MAC_DCU_TXFILTER_DCU8_63_32 - hw6 only (R)
ATH:0210BCh - MAC_DCU_TXFILTER_DCU8_95_64 - hw6 only (R)
ATH:0210FCh - MAC_DCU_TXFILTER_DCU8_127_96 - hw6 only (R)

      0-31   DATA                           (R)

ATH:021138h - MAC_DCU_TXFILTER_DCU1_31_0 - hw6 only (R)
ATH:021178h - MAC_DCU_TXFILTER_DCU1_63_32 - hw6 only (R)
ATH:0211B8h - MAC_DCU_TXFILTER_DCU1_95_64 - hw6 only (R)
ATH:0211F8h - MAC_DCU_TXFILTER_DCU1_127_96 - hw6 only (R)

      0-31   DATA                           (R)

ATH:02113Ch - MAC_DCU_TXFILTER_DCU9_31_0 - hw6 only (R)
ATH:02117Ch - MAC_DCU_TXFILTER_DCU9_63_32 - hw6 only (R)
ATH:0211BCh - MAC_DCU_TXFILTER_DCU9_95_64 - hw6 only (R)
ATH:0211FCh - MAC_DCU_TXFILTER_DCU9_127_96 - hw6 only (R)

      0-31   DATA                           (R)

ATH:021238h - MAC_DCU_TXFILTER_DCU2_31_0 - hw6 only (R)
ATH:021278h - MAC_DCU_TXFILTER_DCU2_63_32 - hw6 only (R)
ATH:0212B8h - MAC_DCU_TXFILTER_DCU2_95_64 - hw6 only (R)
ATH:0212F8h - MAC_DCU_TXFILTER_DCU2_127_96 - hw6 only (R)

      0-31   DATA                           (R)

ATH:021338h - MAC_DCU_TXFILTER_DCU3_31_0 - hw6 only (R)
ATH:021378h - MAC_DCU_TXFILTER_DCU3_63_32 - hw6 only (R)
ATH:0213B8h - MAC_DCU_TXFILTER_DCU3_95_64 - hw6 only (R)
ATH:0213F8h - MAC_DCU_TXFILTER_DCU3_127_96 - hw6 only (R)

      0-31   DATA                           (R)

ATH:021438h - MAC_DCU_TXFILTER_DCU4_31_0 - hw6 only (R)
ATH:021478h - MAC_DCU_TXFILTER_DCU4_63_32 - hw6 only (R)
ATH:0214B8h - MAC_DCU_TXFILTER_DCU4_95_64 - hw6 only (R)
ATH:0214F8h - MAC_DCU_TXFILTER_DCU4_127_96 - hw6 only (R)

      0-31   DATA                           (R)

ATH:021538h - MAC_DCU_TXFILTER_DCU5_31_0 - hw6 only (R)
ATH:021578h - MAC_DCU_TXFILTER_DCU5_63_32 - hw6 only (R)
ATH:0215B8h - MAC_DCU_TXFILTER_DCU5_95_64 - hw6 only (R)
ATH:0215F8h - MAC_DCU_TXFILTER_DCU5_127_96 - hw6 only (R)

      0-31   DATA                           (R)

ATH:021638h - MAC_DCU_TXFILTER_DCU6_31_0 - hw6 only (R)
ATH:021678h - MAC_DCU_TXFILTER_DCU6_63_32 - hw6 only (R)
ATH:0216B8h - MAC_DCU_TXFILTER_DCU6_95_64 - hw6 only (R)
ATH:0216F8h - MAC_DCU_TXFILTER_DCU6_127_96 - hw6 only (R)

      0-31   DATA                           (R)

ATH:021738h - MAC_DCU_TXFILTER_DCU7_31_0 - hw6 only (R)
ATH:021778h - MAC_DCU_TXFILTER_DCU7_63_32 - hw6 only (R)
ATH:0217B8h - MAC_DCU_TXFILTER_DCU7_95_64 - hw6 only (R)
ATH:0217F8h - MAC_DCU_TXFILTER_DCU7_127_96 - hw6 only (R)

      0-31   DATA                           (R)

DSi Atheros Wifi - Internal I/O - 028000h - WMAC PCU (hw2/hw4/hw6)

ATH:028000h - MAC_PCU_STA_ADDR_L32 (aka hw2: REG_STA_ID0) ;hw2/hw4/hw6
ATH:028004h - MAC_PCU_STA_ADDR_U16 (aka hw2: REG_STA_ID1) ;hw2/hw4/hw6

      0-47   ADDR (called STA_ADDR in hw2) (local MAC address)
      48     STA_AP (called AP in hw2)
      49     ADHOC
      50     PW_SAVE (called PWR_SV in hw2)
      51     KEYSRCH_DIS (called NO_KEYSRCH in hw2)
      52     PCF
      53     USE_DEFANT (called USE_DEF_ANT in hw2)
      54     DEFANT_UPDATE (called DEF_ANT_UPDATE in hw2)
      55     RTS_USE_DEF (called RTS_DEF_ANT in hw2)
      56     ACKCTS_6MB
      57     BASE_RATE_11B (called RATE_11B in hw2)
      58     SECTOR_SELF_GEN
      59     CRPT_MIC_ENABLE
      60     KSRCH_MODE
      61     PRESERVE_SEQNUM
      62     CBCIV_ENDIAN
      63     ADHOC_MCAST_SEARCH

ATH:028008h - MAC_PCU_BSSID_L32 (aka hw2: REG_BSS_ID0) ;hw2/hw4/hw6
ATH:02800Ch - MAC_PCU_BSSID_U16 (aka hw2: REG_BSS_ID1) ;hw2/hw4/hw6

      0-47   ADDR (called BSSID in hw2)
      48-58  AID (11bit, although claimed to be 16bit wide, bit48-63 in hw2)

ATH:0282B0h/02839Ch/028398h - MAC_PCU_BSSID2_L32 ;hw2/hw4/hw6
ATH:0282B4h/0283A0h/02839Ch - MAC_PCU_BSSID2_U16 ;hw2/hw4/hw6

      0-47   ADDR    (hw2: SEC_BSSID, ini:0)                ;\hw2/hw4/hw6
      48     ENABLE  (hw2: SEC_BSSID_ENABLE, ini:0)         ;/
      49-51  -
      52-62  hw6: AID                                       ;-hw 6 only
      63     -

Observe that hw2/hw6 port addresses are different here (unlike as usually).
ATH:028010h - MAC_PCU_BCN_RSSI_AVE (aka hw2:BCNRSSI) (R) ;hw2/hw4/hw6

      0-11   AVE_VALUE (aka hw2:BCN_RSSI_AVE ini:800h) (R)  ;-hw2/hw4/hw6
      16-27  hw6: AVE_VALUE2                           (R)  ;-hw6 only

ATH:028014h - MAC_PCU_ACK_CTS_TIMEOUT (aka hw2:REG_TIME_OUT) ;hw2/hw4/hw6

      0-13   ACK_TIMEOUT (aka 16bit wide, bit0-15: ACK_TIME_OUT in hw2)
      16-29  CTS_TIMEOUT (aka 16bit wide, bit16-31: CTS_TIME_OUT in hw2)

ATH:028018h - MAC_PCU_BCN_RSSI_CTL (aka hw2:BCNSIG) ;hw2/hw4/hw6

      0-7    RSSI_LOW_THRESH  (aka hw2: BCN_RSSI_LO_THR, ini:0)
      8-15   MISS_THRESH      (aka hw2: BCN_MISS_THR, ini:FFh)
      16-23  RSSI_HIGH_THRESH (aka hw2: BCN_RSSI_HI_THR, ini:7Fh)
      24-28  WEIGHT           (aka hw2: BCN_RSSI_WEIGHT, ini:0)
      29     RESET            (aka hw2: BCN_RSSI_RESET)

ATH:02801Ch - MAC_PCU_USEC_LATENCY (aka hw2:REG_USEC) ;hw2/hw4/hw6

      <-- hw2 (REG_USEC) -->    <--- hw4/hw6 ---------->
      0-6    USEC     (7bit)    0-7    USEC       (8bit)
      7-13   USEC32   (7bit)    8-13   -          (-)
      14-18  TX_DELAY (5bit)    14-22  TX_LATENCY (9bit)
      19-24  RX_DELAY (6bit)    23-28  RX_LATENCY (6bit)

ATH:02803Ch/028024h/02803Ch - MAC_PCU_RX_FILTER ;hw2/hw4/hw6

      0      UNICAST
      1      MULTICAST
      2      BROADCAST
      3      CONTROL
      4      BEACON
      5      PROMISCUOUS
      6      XR_POLL
      7      PROBE_REQ
      8      hw2: outcommented: SYNC        ;\hw4 and hw6 (outcommented in hw2)
      8      hw4/hw6: SYNC_FRAME            ;/
      9      MY_BEACON
      10     hw4/hw6: COMPRESSED_BAR        ;\
      11     hw4/hw6: COMPRESSED_BA         ;
      12     hw4/hw6: UNCOMPRESSED_BA_BAR   ; hw4 and hw6
      13     hw4/hw6: ASSUME_RADAR          ;
      14     hw4/hw6: PS_POLL               ;
      15     hw4/hw6: MCAST_BCAST_ALL       ;
      16     hw4/hw6: RST_DLMTR_CNT_DISABLE ;/
      17     hw4: FROM_TO_DS                ;\
      18-23  hw4: GENERIC_FTYPE             ; hw4 only (moved to bit20-28 in hw6)
      24-25  hw4: GENERIC_FILTER            ;/
      17     hw6: HW_BCN_PROC_ENABLE        ;\
      18     hw6: MGMT_ACTION_MCAST         ; hw6 only
      19     hw6: CONTROL_WRAPPER           ;
      20     hw6: FROM_TO_DS                ;   ;\these bits were formerly
      21-26  hw6: GENERIC_FTYPE             ;   ; in bit17-25 in hw4)
      27-28  hw6: GENERIC_FILTER            ;   ;/
      29     hw6: MY_BEACON2                ;/

ATH:028040h/028028h/028040h - MAC_PCU_MCAST_FILTER_L32 ;hw2/hw4/hw6
ATH:028044h/02802Ch/028044h - MAC_PCU_MCAST_FILTER_U32 ;hw2/hw4/hw6

      0-63   VALUE (aka hw2: unspecified)

ATH:028048h/028030h/028048h - MAC_PCU_DIAG_SW ;hw2/hw4/hw6

      0      INVALID_KEY_NO_ACK        (aka hw2:DIS_WEP_ACK          ;ini:0)
      1      NO_ACK                    (aka hw2:DIS_ACK              ;ini:0)
      2      NO_CTS                    (aka hw2:DIS_CTS              ;ini:0)
      3      NO_ENCRYPT                (aka hw2:DIS_ENC              ;ini:0)
      4      NO_DECRYPT                (aka hw2:DIS_DEC              ;ini:0)
      5      HALT_RX                   (aka hw2:DIS_RX               ;ini:0)
      6      LOOP_BACK                 (aka hw2:LOOP_BACK            ;ini:0)
      7      CORRUPT_FCS               (aka hw2:CORR_FCS             ;ini:0)
      8      DUMP_CHAN_INFO            (aka hw2:CHAN_INFO            ;ini:0)
      9-16   - (aka hw2: RESERVED)     (aka hw2:RESERVED             ;ini:0)
      17     ACCEPT_NON_V0             (aka hw2:ACCEPT_NONV0         ;ini:0)
      18-19  OBS_SEL_1_0               (aka hw2:OBS_SEL_0_1          ;ini:0)
      20     RX_CLEAR_HIGH             (aka hw2:RXCLR_HIGH           ;ini:0)
      21     IGNORE_NAV                (aka hw2:IGNORE_NAV           ;ini:0)
      22     CHAN_IDLE_HIGH            (aka hw2:CHANIDLE_HIGH        ;ini:0)
      23     PHYERR_ENABLE_EIFS_CTL    (aka hw2:PHYERR_ENABLE_NEW    ;ini:0)
      24     DUAL_CHAIN_CHAN_INFO      (aka hw2:DUAL_CHAIN_CHAN_INFO ;ini:0)
      25     FORCE_RX_ABORT            (aka hw2:FORCE_RX_ABORT       ;ini:0)
      26     SATURATE_CYCLE_CNT        (aka hw2:SATURATE_CYCLE_CNT   ;ini:0)
      27     OBS_SEL_2                 (aka hw2:OBS_SEL_2            ;ini:0)
      28     hw4/hw6: RX_CLEAR_CTL_LOW              ;\
      29     hw4/hw6: RX_CLEAR_EXT_LOW              ; hw4/hw6 only
      30-31  hw4/hw6: DEBUG_MODE                    ;/

ATH:028054h/028034h/028054h - MAC_PCU_TST_ADDAC ;hw2/hw4/hw6

      0      hw2: TEST_MODE                 ;\
      1      hw2: TEST_LOOP                 ; hw2 (moved to bit1-14 in hw4/hw6)
      2-12   hw2: LOOP_LEN                  ;
      13     hw2: TEST_UPPER_8B             ;/
      14     hw2: TEST_MSB                  ;-hw2 only
      15     hw2: TEST_CAPTURE              ;-hw2 (moved to bit19 in hw4/hw6)

Differently arranged in hw4/hw6:

      0      hw4/hw6: CONT_TX               ;-hw4/hw6 only
      1      hw4/hw6: TESTMODE              ;\
      2      hw4/hw6: LOOP                  ; hw4/hw6 (formerly bit0-13 in hw2)
      3-13   hw4/hw6: LOOP_LEN              ;
      14     hw4/hw6: UPPER_8B              ;/
      15     hw6:     SAMPLE_SIZE_2K        ;-hw6 only
      16     hw4/hw6: TRIG_SEL              ;\
      17     hw4/hw6: TRIG_POLARITY         ; hw4/hw6 only
      18     hw4/hw6: CONT_TEST         (R) ;/
      19     hw4/hw6: TEST_CAPTURE          ;-hw4/hw6 (formerly bit15 in hw2)
      20     hw4/hw6: TEST_ARM              ;-hw4/hw6 only

ATH:028058h/028038h/028058h - MAC_PCU_DEF_ANTENNA ;hw2/hw4/hw6

      0-23   VALUE                          ;\hw4/hw6 (and maybe hw2, too)
      24     TX_DEF_ANT_SEL                 ;/
      25     hw6: SLOW_TX_ANT_EN            ;\
      26     hw6: TX_CUR_ANT                ; hw6 only
      27     hw6: FAST_DEF_ANT              ;/
      28     RX_LNA_CONFIG_SEL              ;-hw4/hw6 (and maybe hw2, too)
      29     hw6: FAST_TX_ANT_EN            ;\
      30     hw6: RX_ANT_EN                 ; hw6 only
      31     hw6: RX_ANT_DIV_ON             ;/

ATH:02805Ch/02803Ch/02805Ch - MAC_PCU_AES_MUTE_MASK_0 ;hw2/hw4/hw6

      0-15   FC      (hw2: ini:C7FFh)
      16-31  QOS     (hw2: ini:FFFFh)

ATH:028060h/028040h/028060h - MAC_PCU_AES_MUTE_MASK_1 ;hw2/hw4/hw6

      0-15   SEQ     (hw2: ini:000Fh)
      16-31  FC_MGMT (hw2: ini:E7FFh)

ATH:028064h/028044h/028064h - MAC_PCU_GATED_CLKS ;hw2/hw4/hw6

      0      -         (aka hw2: outcommented: SYNC, ini:1)
      1      GATED_TX  (aka hw2: TX, ini:0)
      2      GATED_RX  (aka hw2: RX, ini:0)
      3      GATED_REG (aka hw2: REG, ini:0)

ATH:028068h/028048h/028068h - MAC_PCU_OBS_BUS_2 (R) ;hw2/hw4/hw6

      0-17   VALUE (aka hw2: OBS_BUS)               (R)  ;-hw2/hw4/hw6
      18-21  hw6: WCF_STATE                         (R)  ;\
      22     hw6: WCF0_FULL                         (R)  ;
      23     hw6: WCF1_FULL                         (R)  ; hw6 only
      24-28  hw6: WCF_COUNT                         (R)  ;
      29     hw6: MACBB_ALL_AWAKE                   (R)  ;/

ATH:02806Ch/02804Ch/02806Ch - MAC_PCU_OBS_BUS_1 (R) ;hw2/hw4/hw6

      0      PCU_DIRECTED                           (R)
      1      PCU_RX_END                             (R)
      2      RX_WEP                                 (R)
      3      RX_MY_BEACON                           (R)
      4      FILTER_PASS                            (R)
      5      TX_HCF                                 (R)
      6      TM_QUIET_TIME    (aka hw2: QUIET_TIME) (R)
      7      PCU_CHANNEL_IDLE (aka hw2: CHAN_IDLE)  (R)
      8      TX_HOLD                                (R)
      9      TX_FRAME                               (R)
      10     RX_FRAME                               (R)
      11     RX_CLEAR                               (R)
      12-17  WEP_STATE                              (R)
      20-23  hw2: RX_STATE (4bit)                   (R)  ;\hw2 (less bits)
      24-28  hw2: TX_STATE (5bit)                   (R)  ;/
      20-24  hw4/hw6: RX_STATE (5bit)               (R)  ;\hw4/hw6 (one more
      25-30  hw4/hw6: TX_STATE (6bit)               (R)  ;/bit than hw2 each)

ATH:028080h/028054h/028080h - MAC_PCU_LAST_BEACON_TSF (R) ;hw2/hw4/hw6
ATH:028664h - MAC_PCU_LAST_BEACON2_TSF ;extra beacon (R) ;hw6 only

      0-31   VALUE (hw2: unspecified/LAST_TSTP)          (R)

ATH:028084h/028058h/028084h - MAC_PCU_NAV ;hw2/hw4/hw6

      0-25   VALUE (hw2: unspecified/NAV)

ATH:028088h/02805Ch/028088h - MAC_PCU_RTS_SUCCESS_CNT (R) ;hw2/hw4/hw6
ATH:02808Ch/028060h/02808Ch - MAC_PCU_RTS_FAIL_CNT (R) ;hw2/hw4/hw6
ATH:028090h/028064h/028090h - MAC_PCU_ACK_FAIL_CNT (R) ;hw2/hw4/hw6
ATH:028094h/028068h/028094h - MAC_PCU_FCS_FAIL_CNT (R) ;hw2/hw4/hw6
ATH:028098h/02806Ch/028098h - MAC_PCU_BEACON_CNT (R) ;hw2/hw4/hw6
ATH:02809Ch - MAC_PCU_BEACON2_CNT (R) ;hw6 only

      0-15   VALUE (COUNT or so?) (hw2: unspecified)     (R)

ATH:0280C0h/028070h/0280C0h - MAC_PCU_XRMODE ;hw2/hw4/hw6

      0-5    POLL_TYPE             (hw2: ini:1Ah)
      7      WAIT_FOR_POLL         (hw2: ini:0)
      20-31  FRAME_HOLD            (hw2: ini:680 decimal)

ATH:0280C4h/028074h/0280C4h - MAC_PCU_XRDEL ;hw2/hw4/hw6

      0-15   SLOT_DELAY            (hw2: ini:360 (decimal)
      16-31  CHIRP_DATA_DELAY      (hw2: ini:1680 decimal)

ATH:0280C8h/028078h/0280C8h - MAC_PCU_XRTO ;hw2/hw4/hw6

      0-15   CHIRP_TIMEOUT         (hw2: ini:7200 decimal)
      16-31  POLL_TIMEOUT          (hw2: ini:5000 decimal)

ATH:0280CCh/02807Ch/0280CCh - MAC_PCU_XRCRP ;hw2/hw4/hw6

      0      SEND_CHIRP            (hw2: ini:0)
      16-31  CHIRP_GAP             (hw2: ini:500 decimal)

ATH:0280D0h/028080h/0280D0h - MAC_PCU_XRSTMP ;hw2/hw4/hw6

      0      RX_ABORT_RSSI         (hw2: ini:0)
      1      RX_ABORT_BSSID        (hw2: ini:0)
      2      TX_STOMP_RSSI         (hw2: ini:0)
      3      TX_STOMP_BSSID        (hw2: ini:0)
      4      TX_STOMP_DATA         (hw2: ini:0)
      5      RX_ABORT_DATA         (hw2: ini:0)
      8-15   TX_STOMP_RSSI_THRESH  (hw2: ini:25h)
      16-23  RX_ABORT_RSSI_THRESH  (hw2: ini:25h)

ATH:0280E0h/028084h/0280E0h - MAC_PCU_ADDR1_MASK_L32 ;hw2/hw4/hw6
ATH:0280E4h/028088h/0280E4h - MAC_PCU_ADDR1_MASK_U16 ;hw2/hw4/hw6

      0-47   VALUE   (aka hw2:BSSID_MASK, ini:FFFFFFFFFFFFh)

This should be 48bit (as so in hw2/hw6, though hw4 claims 64bit, bit0-63).
ATH:0280E8h/02808Ch/0280E8h - MAC_PCU_TPC ;hw2/hw4/hw6

      0-5    ACK_PWR   (hw2: ini:3Fh)
      8-13   CTS_PWR   (hw2: ini:3Fh)
      16-21  CHIRP_PWR (hw2: ini:3Fh)
      24-29  hw6: RPT_PWR                                   ;-hw6 only

ATH:0280ECh/028090h/0280ECh - MAC_PCU_TX_FRAME_CNT ;hw2/hw4/hw6
ATH:0280F0h/028094h/0280F0h - MAC_PCU_RX_FRAME_CNT ;hw2/hw4/hw6
ATH:0280F4h/028098h/0280F4h - MAC_PCU_RX_CLEAR_CNT ;hw2/hw4/hw6
ATH:0280F8h/02809Ch/0280F8h - MAC_PCU_CYCLE_CNT ;hw2/hw4/hw6

      0-31   VALUE (aka COUNT or so?) (aka hw2: CNT, ini:0)

ATH:0280FCh/0280A0h/0280FCh - MAC_PCU_QUIET_TIME_1 ;hw2/hw4/hw6

      0-15   hw2: NEXT_QUIET   (hw2: ini:0)                ;\hw2 only (not hw4/hw6)
      16     hw2: QUIET_ENABLE (hw2: ini:0)                ;/
      17     ACK_CTS_ENABLE    (hw2: ini:1)                ;-hw2/hw4/hw6

ATH:028100h/0280A4h/028100h - MAC_PCU_QUIET_TIME_2 ;hw2/hw4/hw6

      0-15   hw2: QUIET_PERIOD            (hw2: ini:0002h) ;\differs in
      0-15   hw4: -                                        ; hw2, hw4, hw6
      0-15   hw6: DURATION2         ;-hw6 only             ;/
      16-31  DURATION (aka hw2: QUIET_DURATION, ini:0001h) ;-hw2/hw/hw6

ATH:028108h/0280A8h/028108h - MAC_PCU_QOS_NO_ACK ;hw2/hw4/hw6

      0-3    TWO_BIT_VALUES (hw2: NOACK_2_BIT_VALUES, ini:2)
      4-6    BIT_OFFSET     (hw2: NOACK_BIT_OFFSET, ini:5)
      7-8    BYTE_OFFSET    (hw2: NOACK_BYTE_OFFSET, ini:0)

ATH:02810Ch/0280ACh/02810Ch - MAC_PCU_PHY_ERROR_MASK ;hw2/hw4/hw6

      0-31   VALUE          (hw2: PHYERR_MASK, ini:0)

ATH:028110h/0280B0h/028110h - MAC_PCU_XRLAT ;hw2/hw4/hw6

      0-11   VALUE          (hw2: XR_TX_DELAY, ini:168h)

ATH:0280B4h/028114h - MAC_PCU_RXBUF ;hw4/hw6 (not hw2)

      0-10   HIGH_PRIORITY_THRSHD                          ;\hw4/hw6 only (not hw2)
      11     REG_RD_ENABLE                                 ;/

Note: hw2 does have a "MAC_PCU_REG_TSF" register in this place, which seems to be something different than the hw4/hw6 stuff (unless the hw4/hw6 "RXBUF" is related to the hw2 "ACKSIFSMEM" array?).
ATH:028118h/0280B8h/028118h - MAC_PCU_MIC_QOS_CONTROL ;hw2/hw4/hw6

      0-15   VALUE_0..7 (2bit each)  (aka hw2: MICQOSCTL, ini:00AAh)
      16     ENABLE                  (aka hw2: MICQOSCTL_ENABLE, ini:1)

ATH:02811Ch/0280BCh/02811Ch - MAC_PCU_MIC_QOS_SELECT ;hw2/hw4/hw6

      0-31   VALUE_0..7 (4bit each)  (aka hw2: MICQOSSEL, ini:00003210h)

ATH:028124h/0280C4h/028124h - MAC_PCU_FILTER_OFDM_CNT ;hw2/hw4/hw6
ATH:028128h/0280C8h/028128h - MAC_PCU_FILTER_CCK_CNT ;hw2/hw4/hw6

      0-23   VALUE (count or so?)    (hw2: CNT, ini:0)

ATH:02812Ch/0280CCh/02812Ch - MAC_PCU_PHY_ERR_CNT_1 ;hw2/hw4/hw6
ATH:028134h/0280D4h/028134h - MAC_PCU_PHY_ERR_CNT_2 ;hw2/hw4/hw6
ATH:028168h/0280E4h/028168h - MAC_PCU_PHY_ERR_CNT_3 ;hw2/hw4/hw6

      0-23   VALUE (count or so?)    (hw2: PHYCNT, ini:0)

ATH:028130h/0280D0h/028130h - MAC_PCU_PHY_ERR_CNT_1_MASK ;hw2/hw4/hw6
ATH:028138h/0280D8h/028138h - MAC_PCU_PHY_ERR_CNT_2_MASK ;hw2/hw4/hw6
ATH:02816Ch/0280E8h/02816Ch - MAC_PCU_PHY_ERR_CNT_3_MASK ;hw2/hw4/hw6

      0-31   VALUE (mask or so?)     (hw2: PHYCNTMASK, ini:0)

ATH:02813Ch/0280DCh/005144h - MAC_PCU_TSF_THRESHOLD ;hw2/hw4/hw6

      0-15   VALUE                   (hw2: TSFTHRESH, ini:FFFFh)

Observe that hw2/hw6 port addresses are different here (unlike as usually).
ATH:028144h/0280E0h/028144h - MAC_PCU_PHY_ERROR_EIFS_MASK ;hw2/hw4/hw6

      0-31   VALUE                   (hw2: MASK, ini:0)

     ________________________________ Misc Mode ________________________________

ATH:028120h/0280C0h/028120h - MAC_PCU_MISC_MODE ;hw2/hw4/hw6

      0      BSSID_MATCH_FORCE              (hw2: ini:0)
      1      hw2: ACKSIFS_MEMORY_RESERVED   (hw2: ini:0)
      1      hw4/hw6: DEBUG_MODE_AD
      2      MIC_NEW_LOCATION(_ENABLE)      (hw2: ini:0)
      3      TX_ADD_TSF                     (hw2: ini:0)
      4      CCK_SIFS_MODE                  (hw2: ini:0)
      5      hw2: BFCOEF_MODE_RESERVED      (hw2: ini:0)
      6      hw2: BFCOEF_ENABLE             (hw2: ini:0)
      7      hw2: BFCOEF_UPDATE_SELF_GEN    (hw2: ini:1)
      8      hw2: BFCOEF_MCAST              (hw2: ini:1)
      9      hw2: DUAL_CHAIN_ANT_MODE       (hw2: ini:0)
      10     hw2: FALCON_DESC_MODE          (hw2: ini:0)
      5-8    hw4: -
      5      hw6: RXSM2SVD_PRE_RST
      6      hw6: RCV_DELAY_SOUNDING_IM_TXBF
      7-8    hw6: -
      9      hw4/hw6: DEBUG_MODE_BA_BITMAP
      10     hw4/hw6: DEBUG_MODE_SIFS
      11     KC_RX_ANT_UPDATE               (hw2: ini:1)
      12     TXOP_TBTT_LIMIT(_ENABLE)       (hw2: ini:0)
      13     hw2: FALCON_BB_INTERFACE       (hw2: ini:0)
      14     MISS_BEACON_IN_SLEEP           (hw2: ini:1)
      15-16  -
      17     hw2: BUG_12306_FIX_ENABLE      (hw2: ini:1)
      18     FORCE_QUIET_COLLISION          (hw2: ini:0)
      19     hw2: BUG_12549_FORCE_TXBF      (hw2: ini:0)
      20     BT_ANT_PREVENTS_RX             (hw2: ini:1)
      21     TBTT_PROTECT                   (hw2: ini:1)
      22     HCF_POLL_CANCELS_NAV           (hw2: ini:1)
      23     RX_HCF_POLL_ENABLE             (hw2: ini:1)
      24     CLEAR_VMF                      (hw2: ini:0)
      25     CLEAR_FIRST_HCF                (hw2: ini:0)
      26     hw2: ADHOC_MCAST_KEYID_ENABLE  (hw2: ini:0)
      27     hw2: ALLOW_RAC                 (hw2: ini:0)
      28-31  hw2: -
      26     hw4/hw6: CLEAR_BA_VALID
      27     hw4/hw6: SEL_EVM
      28     hw4/hw6: ALWAYS_PERFORM_KEY_SEARCH
      29     hw4/hw6: USE_EOP_PTR_FOR_DMA_WR
      30-31  hw4/hw6: DEBUG_MODE

ATH:02825Ch/028144h/028344h - MAC_PCU_MISC_MODE2 ;hw2/hw4/hw6

      0      hw2: MGMT_CRYPTO_ENABLE        (ini:0) ;moved to bit1 in hw4 ;\
      1      hw2: NO_CRYPTO_FOR_NON_DATA_PKT(ini:0) ;moved to bit2 in hw4 ; hw2
      2-7    hw2: RESERVED                                                ;/
      0      hw4/hw6: BUG_21532_FIX_ENABLE                                ;\
      1      hw4/hw6: MGMT_CRYPTO_ENABLE                                  ; hw4/hw6
      2      hw4/hw6: NO_CRYPTO_FOR_NON_DATA_PKT                          ;/
      3      hw4: RESERVED
      3      hw6: BUG_58603_FIX_ENABLE                                    ;-hw6
      4      hw6 and hw4.2: BUG_58057_FIX_ENABLE ;-hw4.2 and up (not hw2 and hw4.0)
      5      hw4/hw6: RESERVED                                            ;\
      6      hw4/hw6: ADHOC_MCAST_KEYID_ENABLE                            ; hw4/hw6
      7      hw4/hw6: CFP_IGNORE                                          ;/
      8-15   MGMT_QOS                                                     ;-all hw
      16     hw2: BC_MC_WAPI_MODE          (ini:0) ;moved to bit18 in hw4 ;\
      17     hw2: IGNORE_TXOP_FOR_1ST_PKT  (ini:0) ;moved to bit22 in hw4 ; hw2
      18     hw2: IGNORE_TXOP_IF_ZERO      (ini:0) ;moved to bit23 in hw4 ;
      19-31  hw2_ RESERVED                                                ;/
      16     hw4/hw6: ENABLE_LOAD_NAV_BEACON_DURATION                     ;\
      17     hw4/hw6: AGG_WEP                                             ;
      18     hw4/hw6: BC_MC_WAPI_MODE                                     ;
      19     hw4/hw6: DUR_ACCOUNT_BY_BA                                   ; hw4/hw6
      20     hw4/hw6: BUG_28676                                           ;
      21     hw4/hw6: CLEAR_MORE_FRAG                                     ;
      22     hw4/hw6: IGNORE_TXOP_1ST_PKT                                 ;/
      23     hw4: IGNORE_TXOP_IF_ZERO  ;moved to MISC_MODE3.bit22 in hw6  ;\
      24     hw4: PM_FIELD_FOR_DAT     ;moved to MISC_MODE3.bit24 in hw6  ;
      25     hw4: PM_FIELD_FOR_MGMT    ;moved to MISC_MODE3.bit25 in hw6  ; hw4
      26     hw4: BEACON_FROM_TO_DS    ;moved to MISC_MODE3.bit23 in hw6? ;
      27     hw4: RCV_TIMESTAMP_FIX    ;moved to bit25 in hw6             ;
      28-31  hw4: RESERVED                                                ;/
      23     hw6: MPDU_DENSITY_STS_FIX                                    ;\
      24     hw6: MPDU_DENSITY_WAIT_WEP                                   ;
      25     hw6: RCV_TIMESTAMP_FIX    ;moved from bit27 in hw4           ;
      27     hw6: DECOUPLE_DECRYPTION                                     ; hw6
      28     hw6: H_TO_SW_DEBUG_MODE                                      ;
      29     hw6: TXBF_ACT_RPT_DONE_PASS                                  ;
      30     hw6: PCU_LOOP_TXBF                                           ;
      31     hw6: CLEAR_WEP_TXBUSY_ON_TXURN                               ;/

Observe that hw2/hw6 port addresses are different here (unlike as usually).
ATH:0283D0h - MAC_PCU_MISC_MODE3 ;hw6

      0      BUG_55702_FIX_ENABLE
      1      AES_3STREAM
      2      REGULAR_SOUNDING
      3      BUG_58011_FIX_ENABLE
      4      BUG_56991_FIX_ENABLE
      5      WOW_ADDR1_MASK_ENABLE
      6      BUG_61936_FIX_ENABLE
      7      CHECK_LENGTH_FOR_BA
      8-15   BA_FRAME_LENGTH
      16     MATCH_TID_FOR_BA
      17     WAPI_ORDER_MASK
      18     BB_LDPC_EN
      19     SELF_GEN_SMOOTHING
      20     SMOOTHING_FORCE
      21     ALLOW_RAC
      22     IGNORE_TXOP_IF_ZER0  ;uh, ZerNull or Zero?   ;moved from MODE2.bit23
      23     BEACON_FROM_TO_DS_CHECK                      ;moved from MODE2.bit26?
      24     PM_FIELD_FOR_DAT                             ;moved from MODE2.bit24
      25     PM_FIELD_FOR_MGMT                            ;moved from MODE2.bit25
      26     PM_FIELD2_FOR_CTL
      27     PM_FIELD2_FOR_DAT
      28     PM_FIELD2_FOR_MGT
      29     KEY_MISS_FIX
      30     PER_STA_WEP_ENTRY_ENABLE
      31     TIME_BASED_DISCARD_EN

ATH:0283D4h - MAC_PCU_MISC_MODE4 ;hw6

      0      BC_MC_WAPI_MODE2_EN
      1      BC_MC_WAPI_MODE2
      2      SYNC_TSF_ON_BEACON
      3      SYNC_TSF_ON_BCAST_PROBE_RESP
      4      SYNC_TSF_ON_MCAST_PROBE_RESP
      5      SYNC_TSF_ON_UCAST_MOON_PROBE_RESP
      6      SYNC_TSF_ON_UCAST_PROBE_RESP

     ______________________________ Basic Rate Set ______________________________

ATH:0282A4h - MAC_PCU_BASIC_RATE_SET0 ;hw2 (other as in hw4/hw6)
ATH:0282A8h - MAC_PCU_BASIC_RATE_SET1 ;hw2 (other as in hw4/hw6)
ATH:0282ACh - MAC_PCU_BASIC_RATE_SET2 ;hw2 (other as in hw4/hw6)

     Bitfields for hw2 RATE_SET0 register:
      0-4    BRATE_1MB_L             (hw2: ini:#CCK_RATE_1Mb_L)
      5-9    BRATE_2MB_L             (hw2: ini:#CCK_RATE_2Mb_L)
      10-14  BRATE_2MB_S             (hw2: ini:#CCK_RATE_2Mb_S)
      15-19  BRATE_5_5MB_L           (hw2: ini:#CCK_RATE_5_5Mb_L)
      20-24  BRATE_5_5MB_S           (hw2: ini:#CCK_RATE_5_5Mb_S)
      25-29  BRATE_11MB_L            (hw2: ini:#CCK_RATE_11Mb_L)
     Bitfields for hw2 RATE_SET1 register:
      0-4    BRATE_11MB_S            (hw2: ini:#CCK_RATE_11Mb_S)
      5-9    BRATE_6MB               (hw2: ini:#OFDM_RATE_6Mb)
      10-14  BRATE_9MB               (hw2: ini:#OFDM_RATE_6Mb, too?)
      15-19  BRATE_12MB              (hw2: ini:#OFDM_RATE_12Mb)
      20-24  BRATE_18MB              (hw2: ini:#OFDM_RATE_12Mb, too?)
      25-29  BRATE_24MB              (hw2: ini:#OFDM_RATE_24Mb)
     Bitfields for hw2 RATE_SET2 register:
      0-4    BRATE_36MB              (hw2: ini:#OFDM_RATE_24Mb, too?)
      5-9    BRATE_48MB              (hw2: ini:#OFDM_RATE_24Mb, too?)
      10-14  BRATE_54MB              (hw2: ini:#OFDM_RATE_24Mb, too?)

Alongsides, hw2 source code defines following "Rate" values:

      OFDM_RATE_6Mb    = 0Bh     CCK_RATE_1Mb_L   = 1Bh      XR_RATE_0_25Mb   = 03h
      OFDM_RATE_9Mb    = 0Fh     CCK_RATE_2Mb_L   = 1Ah      XR_RATE_0_5Mb    = 07h
      OFDM_RATE_12Mb   = 0Ah     CCK_RATE_2Mb_S   = 1Eh      XR_RATE_1Mb      = 02h
      OFDM_RATE_18Mb   = 0Eh     CCK_RATE_5_5Mb_L = 19h      XR_RATE_2Mb      = 06h
      OFDM_RATE_24Mb   = 09h     CCK_RATE_5_5Mb_S = 1Dh      XR_RATE_3Mb      = 01h
      OFDM_RATE_36Mb   = 0Dh     CCK_RATE_11Mb_L  = 18h      (the XR_stuff might be
      OFDM_RATE_48Mb   = 08h     CCK_RATE_11Mb_S  = 1Ch      unrelated to RATE_SET)
      OFDM_RATE_54Mb   = 0Ch

Note: The hw2 RATE_SET registers contain 75bit (30+30+15bit), hw4/hw6 has similar RATE_SET registers with 100bit (4x25bit), that registers may have similar functions - but their content is obviously differently arranged.
ATH:028328h/0283E0h - MAC_PCU_BASIC_RATE_SET0 ;hw4/hw6 (other as in hw2)
ATH:02832Ch/0283E4h - MAC_PCU_BASIC_RATE_SET1 ;hw4/hw6 (other as in hw2)
ATH:028330h/0283E8h - MAC_PCU_BASIC_RATE_SET2 ;hw4/hw6 (other as in hw2)
ATH:028334h/0283ECh - MAC_PCU_BASIC_RATE_SET3 ;hw4/hw6 (new in hw4/hw6)

      0-24   VALUE (maybe this 25bit value is meant to contain 5 rates of 5bit ?)

Note: The hw4/hw6 RATE_SET registers contain 100bit (4x25bit), hw2 has similar RATE_SET registers with 75bit (30+30+15bit), that registers may have similar functions - but their content is obviously differently arranged.

     ______________________________ Bluetooth Mode ______________________________

ATH:028170h/0280ECh/028170h - MAC_PCU_BLUETOOTH_MODE ;hw2/hw4/hw6

      0-7    TIME_EXTEND            (hw2: ini:20h)
      8      TX_STATE_EXTEND        (hw2: ini:1)
      9      TX_FRAME_EXTEND        (hw2: ini:1)
      10-11  MODE                   (hw2: ini:3)
      12     QUIET                  (hw2: ini:1)
      13-16  QCU_THRESH             (hw2: ini:1)
      17     RX_CLEAR_POLARITY      (hw2: ini:0)
      18-23  PRIORITY_TIME          (hw2: ini:05h)
      24-31  FIRST_SLOT_TIME        (hw2: ini:9Bh)

ATH:02817Ch/0280F4h/02817Ch - MAC_PCU_BLUETOOTH_MODE2 ;hw2/hw4/hw6

      0-7    BCN_MISS_THRESH (hw2: ini:0)
      8-15   BCN_MISS_CNT                           (R)
      16     HOLD_RX_CLEAR (hw2: ini:0)
      17     SLEEP_ALLOW_BT_ACCESS (hw2: WL_CONTROL_ANT, ini:0)
      18     hw2: RESPOND_TO_BT_ACTIVE (hw2: ini:0)                 ;-hw2 only
      19     PROTECT_BT_AFTER_WAKEUP (hw2: ini:0)
      20     DISABLE_BT_ANT (hw2: ini:0)
      21     hw4/hw6: QUIET_2_WIRE                                  ;\
      22-23  hw4/hw6: WL_ACTIVE_MODE                                ;
      24     hw4/hw6: WL_TXRX_SEPARATE                              ;
      25     hw4/hw6: RS_DISCARD_EXTEND                             ; hw4/hw6 only
      26-27  hw4/hw6: TSF_BT_ACTIVE_CTRL                            ;
      28-29  hw4/hw6: TSF_BT_PRIORITY_CTRL                          ;
      30     hw4/hw6: INTERRUPT_ENABLE                              ;
      31     hw4/hw6: PHY_ERR_BT_COLL_ENABLE                        ;/

ATH:028164h/0281D4h - MAC_PCU_BLUETOOTH_MODE3 ;hw4/hw6 (not hw2)

      0-7    WL_ACTIVE_TIME                                ;\
      8-15   WL_QC_TIME                                    ;
      16-19  ALLOW_CONCURRENT_ACCESS                       ;
      20     hw4: SHARED_RX                      ;<-- hw4  ;
      20     hw6: AGC_SATURATION_CNT_ENABLE      ;<-- hw6  ; hw4/hw6 only (not hw2)
      21     WL_PRIORITY_OFFSET_EN                         ;
      22     RFGAIN_LOCK_SRC                               ;
      23     DYNAMIC_PRI_EN                                ;
      24     DYNAMIC_TOGGLE_WLA_EN                         ;
      25-26  SLOT_SLOP                                     ;
      27     BT_TX_ON_EN                                   ;
      28-31  BT_PRIORITY_EXTEND_THRES                      ;/

ATH:028168h/0281D8h - MAC_PCU_BLUETOOTH_MODE4 ;hw4/hw6 (not hw2)

      0-15   BT_ACTIVE_EXTEND                              ;\hw4/hw6 only (not hw2)
      16-31  BT_PRIORITY_EXTEND                            ;/

ATH:0281DCh - MAC_PCU_BLUETOOTH_MODE5 ;hw6 (not hw2/hw4)

      0-2    MCI_WL_LEVEL_MULT                             ;\
      3      TX_ON_SRC                                     ;
      4-19   TIMER_TARGET                                  ; hw6 only (not hw2/hw4)
      20     SHARED_RX                                     ;
      21     USE_BTP_EXT                                   ;/

ATH:028174h/0280F0h/0281E0h - MAC_PCU_BLUETOOTH_WEIGHTS ;hw2/hw4/hw6

      0-15   BT_WEIGHT              (hw2: ini:FA50h)
      16-31  WL_WEIGHT              (hw2: ini:FAA4h)

Observe that hw2/hw6 port addresses are different here (unlike as usually).
For hw4 only: There's also a "WL_WEIGHT_CONTD" in a "WEIGHTS" register.
ATH:028158h - MAC_PCU_BLUETOOTH_WEIGHTS2 ;hw4 only (not hw2/hw6)

      16-31  WL_WEIGHT_CONTD (extends "WL_WEIGHT" or so)   ;-hw4 only (not hw2/hw6)

     _______________________________ hw2/hw6 only _______________________________

ATH:028178h/028154h/028178h - MAC_PCU_HCF_TIMEOUT ;hw2/hw6 (not hw4)

      0-15   VALUE      (hw2: TIMEOUT, ini:100h)           ;-hw2/hw6 only (not hw4)

ATH:0281D0h/0280F8h/0281D0h - MAC_PCU_TXSIFS ;hw2/hw6 (not hw4)

      0-7    SIFS_TIME               (hw2: ini: 16 decimal)
      8-11   TX_LATENCY              (hw2: ini:2)
      12-14  ACK_SHIFT               (hw2: ini:3)

ATH:0281ECh/0280FCh/0281ECh - MAC_PCU_TXOP_X ;hw2/hw6 (not hw4)

      0-7    VALUE                   (hw2: TXOP_X, ini:0)

ATH:0281F0h/028100h/0281F0h - MAC_PCU_TXOP_0_3 ;hw2/hw6 (not hw4)
ATH:0281F4h/028104h/0281F4h - MAC_PCU_TXOP_4_7 ;hw2/hw6 (not hw4)
ATH:0281F8h/028108h/0281F8h - MAC_PCU_TXOP_8_11 ;hw2/hw6 (not hw4)
ATH:0281FCh/02810Ch/0281FCh - MAC_PCU_TXOP_12_15 ;hw2/hw6 (not hw4)

      0-7    TXOP_0 / TXOP_4 / TXOP_8  / TXOP_12   (hw2: ini:0)
      8-15   TXOP_1 / TXOP_5 / TXOP_9  / TXOP_13   (hw2: ini:0)
      16-23  TXOP_2 / TXOP_6 / TXOP_10 / TXOP_14   (hw2: ini:0)
      24-31  TXOP_3 / TXOP_7 / TXOP_11 / TXOP_15   (hw2: ini:0)

     _______________________________ hw4/hw6 only _______________________________

ATH:028304h/028024h - MAC_PCU_BT_WL_1 ;hw4/hw6
ATH:028308h/028028h - MAC_PCU_BT_WL_2 ;hw4/hw6
ATH:02830Ch/02802Ch - MAC_PCU_BT_WL_3 ;hw4/hw6
ATH:028310h/028030h - MAC_PCU_BT_WL_4 ;hw4/hw6

      0-31   WEIGHT

ATH:028314h/028034h - MAC_PCU_COEX_EPTA ;hw4/hw6 only

      0-5    LINKID
      6-12   WT_IDX

ATH:028300h/0281E4h - MAC_PCU_BT_BT_ASYNC ;hw4/hw6 (not hw2)

      0-3    TXHP_WEIGHT                            ;\
      4-7    TXLP_WEIGHT                            ; hw4/hw6 only (not hw2)
      8-11   RXHP_WEIGHT                            ;
      12-15  RXLP_WEIGHT                            ;/

ATH:028110h/028264h - MAC_PCU_LOGIC_ANALYZER ;hw4/hw6 (not hw2)

      0      HOLD                                   ;\
      1      CLEAR                                  ;
      2      STATE                          (R)     ; hw4/hw6 only (not hw2)
      3      ENABLE                                 ;
      4-7    QCU_SEL                                ;
      8-17   INT_ADDR                       (R)     ;
      18-31  DIAG_MODE                              ;/

ATH:028114h/028268h - MAC_PCU_LOGIC_ANALYZER_32L ;hw4/hw6 (not hw2)
ATH:028118h/02826Ch - MAC_PCU_LOGIC_ANALYZER_16U ;hw4/hw6 (not hw2)

      0-47   MASK                                   ;\hw4/hw6 only (not hw2)
      48-31  -                                      ;/

ATH:02815Ch/0281C8h - MAC_PCU_BLUETOOTH_TSF_BT_ACTIVE ;hw4/hw6 (not hw2)

      0-31   VALUE                          (R)     ;-hw4/hw6 only (not hw2)

ATH:028160h/0281CCh - MAC_PCU_BLUETOOTH_TSF_BT_PRIORITY ;hw4/hw6 (not hw2)

      0-31   VALUE                          (R)     ;-hw4/hw6 only (not hw2)

ATH:028318h/028150h - MAC_PCU_COEX_LNAMAXGAIN1 ;hw4/hw6 (not hw2)
ATH:02831Ch/028154h - MAC_PCU_COEX_LNAMAXGAIN2 ;hw4/hw6 (not hw2)
ATH:028320h/028158h - MAC_PCU_COEX_LNAMAXGAIN3 ;hw4/hw6 (not hw2)
ATH:028324h/02815Ch - MAC_PCU_COEX_LNAMAXGAIN4 ;hw4/hw6 (not hw2)

      0-7    MAXGAIN1     ;\that are 4 gain value          ;\
      8-15   MAXGAIN2     ; for each of the 4 registers    ; hw4/hw6 only (not hw2)
      16-23  MAXGAIN3     ; (ie. 16 values in total)       ;
      24-31  MAXGAIN4     ;/                               ;/

ATH:028050h/028070h - MAC_PCU_DYM_MIMO_PWR_SAVE ;hw4/hw6 only

      0      hw4/hw6: USE_MAC_CTRL                          ;\
      1      hw4/hw6: HW_CTRL_EN                            ;
      2      hw4/hw6: SW_CHAIN_MASK_SEL                     ; hw4/hw6 only
      4-6    hw4/hw6: LOW_PWR_CHAIN_MASK                    ;
      8-10   hw4/hw6: HI_PWR_CHAIN_MASK                     ;/

ATH:02811Ch/02829Ch - MAC_PCU_PHY_ERR_CNT_MASK_CONT ;hw4/hw6 (not hw2)

      0-7    MASK1
      8-15   MASK2
      16-23  MASK3

ATH:028120h/028300h - MAC_PCU_AZIMUTH_MODE ;hw4/hw6 (not hw2)

      0      DISABLE_TSF_UPDATE
      1      KEY_SEARCH_AD1
      2      TX_TSF_STATUS_SEL
      3      RX_TSF_STATUS_SEL
      4      CLK_EN
      5      TX_DESC_EN
      6      ACK_CTS_MATCH_TX_AD2
      7      BA_USES_AD1
      8      hw6: WMAC_CLK_SEL
      9      hw6: FILTER_PASS_HOLD

ATH:02814Ch/028314h - MAC_PCU_AZIMUTH_TIME_STAMP ;hw4/hw6 (not hw2)

      0-31   VALUE

ATH:028124h/028318h - MAC_PCU_20_40_MODE ;hw4/hw6 (not hw2)

      0      JOINED_RX_CLEAR
      1      EXT_PIFS_ENABLE
      2      TX_HT20_ON_EXT_BUSY
      3      SWAMPED_FORCES_RX_CLEAR_CTL_IDLE
      4-15   PIFS_CYCLES

ATH:028128h/028328h - MAC_PCU_RX_CLEAR_DIFF_CNT ;hw4/hw6 (not hw2)

      0-31   VALUE

ATH:02812Ch/02832Ch - MAC_PCU_SELF_GEN_ANTENNA_MASK ;hw4/hw6 (not hw2)

      0-2    VALUE
      3      hw6: ONE_RESP_EN
      4      hw6: FORCE_CHAIN_0

ATH:028130h/028330h - MAC_PCU_BA_BAR_CONTROL ;hw4/hw6 (not hw2)

      0-3    COMPRESSED_OFFSET
      4-7    ACK_POLICY_OFFSET
      8      COMPRESSED_VALUE
      9      ACK_POLICY_VALUE
      10     FORCE_NO_MATCH
      11     TX_BA_CLEAR_BA_VALID
      12     UPDATE_BA_BITMAP_QOS_NULL

ATH:028134h/028334h - MAC_PCU_LEGACY_PLCP_SPOOF ;hw4/hw6 (not hw2)

      0-7    EIFS_MINUS_DIFS
      8-12   MIN_LENGTH

ATH:028138h/028338h - MAC_PCU_PHY_ERROR_MASK_CONT ;hw4/hw6 (not hw2)

      0-7    MASK_VALUE
      16-23  EIFS_VALUE
      24-31  hw6: AIFS_VALUE

ATH:02813Ch/02833Ch - MAC_PCU_TX_TIMER ;hw4/hw6 (not hw2)

      0-14   TX_TIMER
      15     TX_TIMER_ENABLE
      16-19  RIFS_TIMER
      20-24  QUIET_TIMER
      25     QUIET_TIMER_ENABLE

ATH:028140h/028340h - MAC_PCU_TXBUF_CTRL ;hw4/hw6 (not hw2)

      0-11   USABLE_ENTRIES
      16     TX_FIFO_WRAP_ENABLE

ATH:028148h/028348h - MAC_PCU_ALT_AES_MUTE_MASK ;hw4/hw6 (not hw2)

      16-31  QOS

ATH:028338h/028600h - MAC_PCU_RX_INT_STATUS0 ;hw4/hw6

      0-7    FRAME_CONTROL_L                (R)
      8-15   FRAME_CONTROL_H                (R)
      16-23  DURATION_L                     (R)
      24-31  DURATION_H                     (R)

ATH:02833Ch/028604h - MAC_PCU_RX_INT_STATUS1 ;hw4/hw6

      0-17   VALUE                          (R)

ATH:028340h/028608h - MAC_PCU_RX_INT_STATUS2 ;hw4/hw6

      0-26   VALUE                          (R)

ATH:028344h/02860Ch - MAC_PCU_RX_INT_STATUS3 ;hw4/hw6

      0-23   VALUE                          (R)

ATH:028348h/028610h - HT_HALF_GI_RATE1 ;MCS0..3 ;hw4/hw6
ATH:02834Ch/028614h - HT_HALF_GI_RATE2 ;MCS4..7 ;hw4/hw6

      0-7    MCS0 / MCS4
      8-15   MCS1 / MCS5
      16-23  MCS2 / MCS6
      24-31  MCS3 / MCS7

ATH:028350h/028618h - HT_FULL_GI_RATE1 ;MCS0..3 ;hw4/hw6
ATH:028354h/02861Ch - HT_FULL_GI_RATE2 ;MCS4..7 ;hw4/hw6

      0-7    MCS0 / MCS4
      8-15   MCS1 / MCS5
      16-23  MCS2 / MCS6
      24-31  MCS3 / MCS7

ATH:028358h/028620h - LEGACY_RATE1 ;RATE 8..12 ;hw4/hw6
ATH:02835Ch/028624h - LEGACY_RATE2 ;RATE 13..15 and RATE 24..25 ;hw4/hw6
ATH:028360h/028628h - LEGACY_RATE3 ;RATE 26..30 ;hw4/hw6

      0-5    RATE8  / RATE13 / RATE26
      6-11   RATE9  / RATE14 / RATE27
      12-17  RATE10 / RATE15 / RATE28
      18-23  RATE11 / RATE24 / RATE29
      24-29  RATE12 / RATE25 / RATE30

ATH:028364h/02862Ch - RX_INT_FILTER ;hw4/hw6

      0      ENABLE
      1      DIRECTED
      2      BCAST
      3      MCAST
      4      RTS
      5      ACK
      6      CTS
      7      RETRY
      8      MORE_DATA
      9      MORE_FRAG
      10     RATE_HIGH
      11     RATE_LOW
      12     RSSI
      13     LENGTH_HIGH
      14     LENGTH_LOW
      15     EOSP
      16     AMPDU
      17     hw4.2: BEACON                  ;-hw6 and newer "hw4.2" revision only
      18     hw6:   RSSI_HIGH               ;-hw6 only

ATH:028368h/028630h - RX_INT_OVERFLOW ;hw4/hw6

      0      STATUS

ATH:02836Ch/028634h - RX_FILTER_THRESH0 ;hw4/hw6

      0-7    RATE_HIGH
      8-15   RATE_LOW
      16-23  RSSI_LOW
      24-31  hw6: RSSI_HIGH

ATH:028370h/028638h - RX_FILTER_THRESH1 ;hw4/hw6

      0-11   LENGTH_HIGH
      12-23  LENGTH_LOW

ATH:028374h/02863Ch - RX_PRIORITY_THRESH0 ;hw4/hw6

      0-7    RATE_HIGH
      8-15   RATE_LOW
      16-23  RSSI_HIGH
      24-31  RSSI_LOW

ATH:028378h/028640h - RX_PRIORITY_THRESH1 ;hw4/hw6

      0-11   LENGTH_HIGH
      12-23  LENGTH_LOW
      24-31  XCAST_RSSI_HIGH

ATH:02837Ch/028644h - RX_PRIORITY_THRESH2 ;hw4/hw6

      0-7    PRESP_RSSI_HIGH
      8-15   MGMT_RSSI_HIGH
      16-23  BEACON_RSSI_HIGH
      24-31  NULL_RSSI_HIGH

ATH:028380h/028648h - RX_PRIORITY_THRESH3 ;hw4/hw6

      0-7    PREQ_RSSI_HIGH
      8-15   PS_POLL_RSSI_HIGH

ATH:028384h/02864Ch - RX_PRIORITY_OFFSET0 ;hw4/hw6

      0-5    PHY_RATE_HIGH
      6-11   PHY_RATE_LOW
      12-17  RSSI_HIGH
      18-23  RSSI_LOW
      24-29  XCAST_RSSI_HIGH

ATH:028388h/028650h - RX_PRIORITY_OFFSET1 ;hw4/hw6

      0-5    LENGTH_HIGH
      6-11   LENGTH_LOW
      12-17  PRESP_RSSI_HIGH
      18-23  RETX
      24-29  RTS

ATH:02838Ch/028654h - RX_PRIORITY_OFFSET2 ;hw4/hw6

      0-5    XCAST
      6-11   PRESP
      12-17  ATIM
      18-23  MGMT
      24-29  BEACON

ATH:028390h/028658h - RX_PRIORITY_OFFSET3 ;hw4/hw6

      0-5    MORE
      6-11   EOSP
      12-17  AMPDU
      18-23  AMSDU
      24-29  PS_POLL

ATH:028394h/02865Ch - RX_PRIORITY_OFFSET4 ;hw4/hw6

      0-5    PREQ
      6-11   NULL
      12-17  BEACON_SSID
      18-23  MGMT_RSSI_HIGH
      24-29  BEACON_RSSI_HIGH

ATH:028398h/028660h - RX_PRIORITY_OFFSET5 ;hw4/hw6

      0-5    NULL_RSSI_HIGH
      6-11   PREQ_RSSI_HIGH
      12-17  PS_POLL_RSSI_HIGH

ATH:028200h..0282FCh - MAC_PCU_BT_BT[0..63] ;hw4 (at 028200h)
ATH:028500h..0285FCh - MAC_PCU_BT_BT[0..63] ;hw6 (at 028500h)

      0-31   WEIGHT

ATH:028400h..0284FCh - MAC_PCU_TXBUF_BA[0..63] ;hw4/hw6

      0-31   DATA

ATH:028800h..028BFCh - MAC_PCU_KEY_CACHE_1[0..255] ;hw4 (256 words)
ATH:028800h..028FFCh - MAC_PCU_KEY_CACHE[0..511] ;hw6 (512 words)

      0-31   DATA

ATH:02E000h..02E7FCh - MAC_PCU_BUF[0..511] ;hw4 (512 words)
ATH:02E000h..02FFFCh - MAC_PCU_BUF[0..2047] ;hw6 (2048 words)

      0-31   DATA

     _________________________________ hw6 only _________________________________

ATH:0280A0h - MAC_PCU_BASIC_SET ;hw6 only

      0-31   MCS                                            ;-hw6 only

ATH:0280A4h - MAC_PCU_MGMT_SEQ ;hw6 only

      0-11   MIN                                            ;\hw6 only
      16-27  MAX                                            ;/

ATH:0280A8h - MAC_PCU_BF_RPT1 ;hw6 only

      0-7    V_ACTION_VALUE                                 ;\
      8-15   CV_ACTION_VALUE                                ; hw6 only
      16-23  CATEGORY_VALUE                                 ;
      24-27  FRAME_SUBTYPE_VALUE                            ;
      28-29  FRAME_TYPE_VALUE                               ;/

ATH:0280ACh - MAC_PCU_BF_RPT2 ;hw6 only

      0-3    FRAME_SUBTYPE_VALUE                            ;-hw6 only

ATH:0280B0h - MAC_PCU_TX_ANT_1 ;hw6 only
ATH:0280B4h - MAC_PCU_TX_ANT_2 ;hw6 only
ATH:0280B8h - MAC_PCU_TX_ANT_3 ;hw6 only
ATH:0280BCh - MAC_PCU_TX_ANT_4 ;hw6 only

      0-31   VALUE                                          ;-hw6 only

ATH:028038h - MAC_PCU_MAX_CFP_DUR ;hw6 only (merged two hw4 registers here)

      0-15   VALUE                     ;-formerly bit0-15 of "PCU_MAX_CFP_DUR"
      16-19  USEC_FRAC_NUMERATOR       ;-formerly bit0-3 of "MAC_PCU_MAX_CFP_DUR"
      24-27  USEC_FRAC_DENOMINATOR     ;-formerly bit4-7 of "MAC_PCU_MAX_CFP_DUR"

ATH:028020h - MAC_PCU_BCN_RSSI_CTL2 ;hw6 only

      0-7    RSSI2_LOW_THRESH
      16-23  RSSI2_HIGH_THRESH
      29     RESET2

ATH:0280DCh - MAC_PCU_SELF_GEN_DEFAULT ;hw6 only

      0-2    MMSS                                           ;\
      3-4    CEC                                            ; hw6 only
      5      STAGGER_SOUNDING                               ;/

ATH:02831Ch - MAC_PCU_H_XFER_TIMEOUT ;hw6 only

      0-4    VALUE                                          ;\
      5      DISABLE                                        ;
      6      EXTXBF_IMMEDIATE_RESP                          ; hw6 only
      7      DELAY_EXTXBF_ONLY_UPLOAD_H                     ;
      8      EXTXBF_NOACK_NORPT                             ;/

ATH:028200h - MAC_PCU_TDMA_TXFRAME_START_TIME_TRIGGER_LSB ;hw6

      0-31   VALUE

ATH:028204h - MAC_PCU_TDMA_TXFRAME_START_TIME_TRIGGER_MSB ;hw6

      0-31   VALUE

ATH:028208h - MAC_PCU_TDMA_SLOT_ALERT_CNTL ;hw6

      0-15   VALUE

ATH:028284h - PCU_1US ;hw6

      0-6    SCALER

ATH:028288h - PCU_KA ;hw6

      0-11   DEL

ATH:028350h - ASYNC_FIFO_REG1 ;hw6

      0-29   DBG

ATH:028354h - ASYNC_FIFO_REG2 ;hw6

      0-27   DBG

ATH:028358h - ASYNC_FIFO_REG3 ;hw6

      0-9    DBG
      10     DATAPATH_SEL
      31     SFT_RST_N

ATH:028388h - MAC_PCU_LOCATION_MODE_CONTROL ;hw6

      0      ENABLE
      1      UPLOAD_H_DISABLE

ATH:02838Ch - MAC_PCU_LOCATION_MODE_TIMER ;hw6

      0-31   VALUE

ATH:0283A0h - MAC_PCU_DIRECT_CONNECT ;hw6

      0      TSF2_ENABLE
      1      TS_TSF_SEL
      2      TSF1_UPDATE
      3      TSF2_UPDATE
      4      MY_BEACON_OVERRIDE
      5      MY_BEACON2_OVERRIDE
      6      BMISS_CNT_TSF_SEL
      7      BMISS_CNT_OVERRIDE
      8-31   RESERVED

ATH:0283A4h - MAC_PCU_TID_TO_AC ;hw6

      0-31   DATA

ATH:0283A8h - MAC_PCU_HP_QUEUE ;hw6

      0      ENABLE
      1      AC_MASK_BE
      2      AC_MASK_BK
      3      AC_MASK_VI
      4      AC_MASK_VO
      5      HPQON_UAPSD
      6      FRAME_FILTER_ENABLE0
      7      FRAME_BSSID_MATCH0
      8-9    FRAME_TYPE0
      10-11  FRAME_TYPE_MASK0
      12-15  FRAME_SUBTYPE0
      16-19  FRAME_SUBTYPE_MASK0
      20     UAPSD_EN
      21     PM_CHANGE
      22     NON_UAPSD_EN
      23     UAPSD_AC_MUST_MATCH
      24     UAPSD_ONLY_QOS

ATH:0283BCh - MAC_PCU_AGC_SATURATION_CNT0 ;hw6
ATH:0283C0h - MAC_PCU_AGC_SATURATION_CNT1 ;hw6
ATH:0283C4h - MAC_PCU_AGC_SATURATION_CNT2 ;hw6

      0-31   VALUE

ATH:0283C8h - MAC_PCU_HW_BCN_PROC1 ;hw6

      0      CRC_ENABLE
      1      RESET_CRC
      2      EXCLUDE_BCN_INTVL
      3      EXCLUDE_CAP_INFO
      4      EXCLUDE_TIM_ELM
      5      EXCLUDE_ELM0
      6      EXCLUDE_ELM1
      7      EXCLUDE_ELM2
      8-15   ELM0_ID
      16-23  ELM1_ID
      24-31  ELM2_ID

ATH:0283CCh - MAC_PCU_HW_BCN_PROC2 ;hw6

      0      FILTER_INTERVAL_ENABLE
      1      RESET_INTERVAL
      2      EXCLUDE_ELM3
      8-15   FILTER_INTERVAL
      16-23  ELM3_ID

ATH:0283DCh - MAC_PCU_PS_FILTER ;hw6

      0      ENABLE
      1      PS_SAVE_ENABLE

ATH:028668h - MAC_PCU_PHY_ERROR_AIFS ;hw6

      0      MASK_ENABLE

ATH:02866Ch - MAC_PCU_PHY_ERROR_AIFS_MASK ;hw6

      0-31   VALUE

ATH:028670h - MAC_PCU_FILTER_RSSI_AVE ;hw6

      0-7    AVE_VALUE
      8-10   NUM_FRAMES_EXPONENT
      11     ENABLE
      12     RESET

ATH:028674h - MAC_PCU_TBD_FILTER ;hw6

      0      USE_WBTIMER_TX_TS
      1      USE_WBTIMER_RX_TS

ATH:028678h - MAC_PCU_BT_ANT_SLEEP_EXTEND ;hw6

      0-15   CNT

     _____________________ Wake on Wireless (WOW) hw6 only _____________________

ATH:02825Ch - MAC_PCU_WOW1 ;WOW Misc ;hw6

      0-7    PATTERN_ENABLE
      8-15   PATTERN_DETECT                 (R)
      16     MAGIC_ENABLE
      17     MAGIC_DETECT                   (R)
      18     INTR_ENABLE
      19     INTR_DETECT                    (R)
      20     KEEP_ALIVE_FAIL                (R)
      21     BEACON_FAIL                    (R)
      28-31  CW_BITS

ATH:028260h - MAC_PCU_WOW2 ;WOW AIFS/SLOT/TRY_CNT ;hw6

      0-7    AIFS
      8-15   SLOT
      16-23  TRY_CNT

ATH:028270h - MAC_PCU_WOW3_BEACON_FAIL ;WOW Beacon Fail Enable ;hw6

      0      ENABLE

ATH:028274h - MAC_PCU_WOW3_BEACON ;WOW Beacon Timeout ;hw6
ATH:028278h - MAC_PCU_WOW3_KEEP_ALIVE ;WOW Keep-Alive Timeout ;hw6

      0-31   TIMEOUT

ATH:028370h - MAC_PCU_WOW4 ;WOW Pattern Enable/Detect ;hw6

      0-7    PATTERN_ENABLE
      8-15   PATTERN_DETECT                 (R)

ATH:02835Ch - MAC_PCU_WOW5 ;WOW RX Abort Enable ;hw6

      0-15   RX_ABORT_ENABLE

ATH:02834Ch - MAC_PCU_WOW6 (R) ;WOW RX Buf Start Addr ;hw6

      0-15   RXBUF_START_ADDR               (R)

ATH:02827Ch - MAC_PCU_WOW_KA ;WOW Auto/Fail/BkoffCs Enable/Disable ;hw6

      0      AUTO_DISABLE
      1      FAIL_DISABLE
      2      BKOFF_CS_ENABLE

ATH:028294h - PCU_WOW4 ;WOW Offset 0..3 ;hw6
ATH:028298h - PCU_WOW5 ;WOW Offset 4..7 ;hw6
ATH:028378h - PCU_WOW6 ;WOW Offset 8..11 ;hw6
ATH:02837Ch - PCU_WOW7 ;WOW Offset 12..15 ;hw6

      0-7    OFFSET0 / OFFSET4 / OFFSET8  / OFFSET12        ;<-- 1st offset in LSBs
      8-15   OFFSET1 / OFFSET5 / OFFSET9  / OFFSET13
      16-23  OFFSET2 / OFFSET6 / OFFSET10 / OFFSET14
      24-31  OFFSET3 / OFFSET7 / OFFSET11 / OFFSET15

ATH:028360h - MAC_PCU_WOW_LENGTH1 ;WOW Pattern 0..3 ;hw6
ATH:028364h - MAC_PCU_WOW_LENGTH2 ;WOW Pattern 4..7 ;hw6
ATH:028380h - MAC_PCU_WOW_LENGTH3 ;WOW Pattern 8..11 ;hw6
ATH:028384h - MAC_PCU_WOW_LENGTH4 ;WOW Pattern 12..15 ;hw6

      0-7    PATTERN_3 / PATTERN_7 / PATTERN_11 / PATTERN_15
      8-15   PATTERN_2 / PATTERN_6 / PATTERN_10 / PATTERN_14
      16-23  PATTERN_1 / PATTERN_5 / PATTERN_9  / PATTERN_13
      24-31  PATTERN_0 / PATTERN_4 / PATTERN_8  / PATTERN_12   ;1st pattern in MSBs

ATH:02828Ch - WOW_EXACT ;WOW Exact Length/Offset 1 ;hw6
ATH:028374h - WOW2_EXACT ;WOW Exact Length/Offset 2 ;hw6

      0-7    LENGTH
      8-15   OFFSET

ATH:028368h - WOW_PATTERN_MATCH_LESS_THAN_256_BYTES ;hw6

      0-15   EN

     _________________________________ hw4 only _________________________________

ATH:028020h - PCU_MAX_CFP_DUR ;hw4 only

      0-15   VALUE

Note: This register does have (almost) the same name as the register below, but without the "MAC_" prefix. In hw6, these two registers have been merged into a single register (called MAC_PCU_MAX_CFP_DUR). In hw2, registers REG_CFP_PERIOD and REG_CFP_DUR might be equivalent?
ATH:028150h - MAC_PCU_MAX_CFP_DUR ;hw4 only

      0-3    USEC_FRAC_NUMERATOR
      4-7    USEC_FRAC_DENOMINATOR

Note: See "PCU_MAX_CFP_DUR" (other register with similar name, but without "MAC_" prefix).
ATH:0283A4h - MAC_PCU_TSF1_STATUS_L32 ;hw4 only
ATH:0283A8h - MAC_PCU_TSF1_STATUS_U32 ;hw4 only

      0-63   VALUE

ATH:0283ACh - MAC_PCU_TSF2_STATUS_L32 ;hw4 only
ATH:0283B0h - MAC_PCU_TSF2_STATUS_U32 ;hw4 only

      0-63   VALUE

ATH:029800h..029FFCh - MAC_PCU_BASEBAND_0[0..511] ;hw4
ATH:02A000h..02BFFCh - MAC_PCU_BASEBAND_1[0..2047] ;hw4

      0-31   DATA

These two "MAC_PCU" areas are just placeholders for the Baseband Registers at 029800h and up (see BB chapter for details).
ATH:02C000h..02CFFCh - MAC_PCU_BASEBAND_2[0..1023] ;hw4
ATH:02D000h..02DFFCh - MAC_PCU_BASEBAND_3[0..1023] ;hw4

      0-31   DATA

Unknown what these two "MAC_PCU" areas are intended for.

     _________________________________ hw2 only _________________________________

ATH:028500h.. (140h..17Fh) - MAC_PCU_REG_FTYPE[0..3Fh] ;hw2

      0      BFCOEF_RX_UPDATE_NORMAL
      1      BFCOEF_RX_UPDATE_SELF_GEN
      2      BFCOEF_TX_ENABLE_NORMAL
      3      BFCOEF_TX_ENABLE_SELF_GEN
      4      BFCOEF_TX_ENABLE_GEN
      5      BFCOEF_TX_ENABLE_MCAST
      6      FILTER_PASS_IF_ALL
      7      FILTER_PASS_IF_DIRECTED
      8      FILTER_PASS_IF_MCAST
      9      FILTER_PASS_IF_BCAST
      10     FILTER_PASS_MC_BC_BSSID

ATH:028020h - REG_BEACON ;hw2 only

      0-15   BEACON_PERIOD
      16-22  TIM_OFFSET
      23     unspecified
      24     RESET_TSF           <--- related to hw4/hw6: see MAC_PCU_RESET_TSF ?

ATH:028024h - REG_CFP_PERIOD ;hw2 only
ATH:028038h - REG_CFP_DUR ;hw2 only

      unspecified

These two hw2 registers have unspecified content and purpose. Going by the names, they might be similar or equivalent to "MAC_PCU_MAX_CFP_DUR" and "PCU_MAX_CFP_DUR" on hw4 (although if so, unknown which one would be which).
ATH:028028h - REG_TIMER0 ;hw2 only
ATH:02802Ch - REG_TIMER1 ;hw2 only
ATH:028030h - REG_TIMER2 ;hw2 only
ATH:028034h - REG_TIMER3 ;hw2 only

      unspecified         ;MAYBE related to MAC_PCU_BT_WL_1..4 or so in hw4/hw6 (?)

ATH:02804Ch - REG_TSF_L32 ;hw2 only ... aka MAC_PCU_TSF_L32 ?
ATH:028050h - REG_TSF_U32 ;hw2 only ... aka MAC_PCU_TSF_U32 ?

      unspecified

ATH:028104h - MAC_PCU_REG_TSF ;hw2 only ;aka MAC_PCU_TSF_ADD_PLL on hw4?

      0-7    TSF_INCREMENT          (hw2: ini:1)                    ;-hw2 only

ATH:028114h - MAC_PCU_REG_ACKSIFS_RESERVED ;hw2 only

      0-7    ACKSIFS_INCREMENT_RESERVED     (hw2: ini:0)            ;-hw2 only

Related to the "MAC_PCU_REG_ACKSIFSMEM_RESERVED[0..1Fh]" array?
ATH:028680h.. (1A0h..1BFh) - MAC_PCU_REG_ACKSIFSMEM_RESERVED[0..1Fh] ;hw2

      0-9    NORMAL_RESERVED
      10-19  TURBO_RESERVED

ATH:028700h.. (1C0h..1DFh) - MAC_PCU_REG_DUR[0..1Fh] ;hw2

      0-15   DUR_RATE_TO_DURATION

ATH:0287C0h.. (1F0h..1F7h) - MAC_PCU_REG_RTD[0..7] ;hw2

      0-4    RTD_RATE_TO_DB_0
      8-12   RTD_RATE_TO_DB_1
      16-20  RTD_RATE_TO_DB_2
      24-28  RTD_RATE_TO_DB_3

ATH:0287E0h.. (1F8h..1FFh) - MAC_PCU_REG_DTR[0..7] ;hw2

      0-4    DTR_DB_TO_RATE_0
      8-12   DTR_DB_TO_RATE_1
      16-20  DTR_DB_TO_RATE_2
      24-28  DTR_DB_TO_RATE_3

ATH:028800h.. (200h..5FFh) - MAC_PCU_REG_KC[0..3FFh] ;hw2
Below bitfields are supposedly somehow stored in multiple words...?

      0-31   KC_KEY_31_0                ;aka byte 00h..03h ?
      0-15   KC_KEY_47_32               ;aka byte 04h..05h (and 06h..07h unused?) ?
      0-31   KC_KEY_79_48               ;aka byte 08h..0Bh ?
      0-15   KC_KEY_95_80               ;aka byte 0Ch..0Dh (and 0Eh..0Fh unused?) ?
      0-31   KC_KEY_127_96              ;aka byte 10h..13h ?
      0-2    KC_KEY_TYPE                ;\
      3      KC_LAST_ANTENNA            ;
      4-8    KC_ASYNC_ACK_OFFSET        ;
      9      KC_UPDATE_BEAM_FORMING     ;aka byte 14h..15h (and 16h..17h unused?) ?
      10     KC_RX_CHAIN_0_ACK_ANT      ;
      11     KC_RX_CHAIN_1_ACK_ANT      ;
      12     KC_TX_CHAIN_0_ANT_SEL      ;
      13     KC_TX_CHAIN_1_ANT_SEL      ;
      14     KC_TX_CHAIN_SEL            ;/
      0-31   KC_ADDR_32_1               ;aka byte 18h..1Bh ? (no bit 0 ?)
      0-14   KC_ADDR_47_33              ;aka byte 1Ch..1Dh (and 1Eh..1Fh unused?) ?
      1      KC_VALID                   ;aka byte 20h      (and 21h..xxh unused?) ?

ATH:028180h..02819Ch - MAC_PCU_REG_BFCOEF1[0..7] ;hw2

      0-23   TSF
      24-30  KEYIDX
      31     KEY_VALID                    (hw2: ini:0)

ATH:0281C0h - MAC_PCU_REG_BFCOEF2 ;hw2

      0-22   THRESH                       (hw2: ini:0)
      23     unspecified
      24-31  LOCK                         (hw2: ini:0)

ATH:0281C4h - MAC_PCU_REG_KCMASK ;hw2

      0-15   KCMASK_47_32                 (hw2: ini:0000h)
      16     KCMASK_31_0                  (hw2: ini:0)

     ___________________________ hw2 "MCI" registers ___________________________

Below "MCIxxx" registers exist on hw2 only. Purpose is unknown. There seems to be nothing equivalent in hw4. However, hw6 is having several "MCI_xxx" registers (see WLAN Coex section; unknown if that's related to hw2 MCI stuff).
ATH:028268h - MAC_PCU_REG_MCICTL ;Control ;hw2

      0      MCI_ENABLE              (hw2: ini:0)
      1      OLA_ENABLE              (hw2: ini:1)
      2      PREEMPT_ENABLE          (hw2: ini:1)
      3      CHANNEL_BUSY_ENABLE     (hw2: ini:1)
      4-9    EARLY_NOTIFY_DELAY      (hw2: ini:5)
      10     BMISS_FORCE_WL          (hw2: ini:0)
      11     SLEEP_FORCE_BT          (hw2: ini:1)
      12     HP_QCU_STOMP_BT         (hw2: ini:0)
      31     MCI_BUSY

ATH:02826Ch - MAC_PCU_REG_MCIISR ;Interrupt Status ;hw2
ATH:028270h - MAC_PCU_REG_MCIIER ;Interrupt Enable ;hw2

      0      ACT_RPT_RCV_INT         (hw2: stat and enable: ini:0)
      1      ACT_DEN_RCV_INT         (hw2: stat and enable: ini:0)
      2      FRQ_RPT_RCV_INT         (hw2: stat and enable: ini:0)
      3      QOS_RPT_RCV_INT         (hw2: stat and enable: ini:0)
      4      GEN_RPT_RCV_INT         (hw2: stat and enable: ini:0)

ATH:028274h - MAC_PCU_REG_MCIWLP ;WLP ?? ;hw2 (hw2: ini:0)

      unspecified

ATH:028278h - MAC_PCU_REG_MCIARW ;AR Write? ;hw2 (hw2: ini:0)
ATH:02827Ch - MAC_PCU_REG_MCIARR ;AR Read? ;hw2
ATH:028280h - MAC_PCU_REG_MCIADW ;AD Write? ;hw2 (hw2: ini:0)
ATH:028284h - MAC_PCU_REG_MCIADR ;AD Read? ;hw2
ATH:028288h - MAC_PCU_REG_MCIFRW ;FR Write? ;hw2 (hw2: ini:0)
ATH:02828Ch - MAC_PCU_REG_MCIFRR ;FR Read? ;hw2
ATH:028290h - MAC_PCU_REG_MCIQRW ;QR Write? ;hw2 (hw2: ini:0)
ATH:028294h - MAC_PCU_REG_MCIQRR ;QR Read? ;hw2
ATH:028298h - MAC_PCU_REG_MCIGRW ;GR Write? ;hw2 (hw2: ini:0)
ATH:02829Ch - MAC_PCU_REG_MCIGRR ;GR Read? ;hw2

      unspecified

ATH:0282A0h - MAC_PCU_REG_MCISTAT ;Status (counters?) ;hw2

      0-7    ACT_RPT_RCV_CNT         (hw2: ini:0)
      8-15   QC_CNT                  (hw2: ini:0)
      16-23  OLA_CNT                 (hw2: ini:0)
      24-31  PREEMPT_CNT             (hw2: ini:0)

     ___________ hw2 MAC_PCU registers (moved to RTC WLAN in hw4/hw6) ___________

ATH:028200h..02821Ch - MAC_PCU_REG_GNRCTMR_N[0..7] ;hw2
ATH:028220h..02823Ch - MAC_PCU_REG_GNRCTMR_P[0..7] ;hw2
ATH:028240h - MAC_PCU_GENERIC_TIMERS_MODE ;aka MAC_PCU_REG_GNRCTMR_M ;hw2
ATH:0280D4h - MAC_PCU_SLP1 ;aka MAC_PCU_REG_SLP1 ;hw2
ATH:0280D8h - MAC_PCU_SLP2 ;aka MAC_PCU_REG_SLP2 ;hw2
ATH:0280DCh - (outcommented) ;aka MAC_PCU_REG_SLP3 ;hw2 (but outcommented)
ATH:028260h - MAC_PCU_SLP3 ;aka old name: MAC_PCU_REG_SLP4 (four) ;hw2
This stuff is located in "WMAC PCU" at 028xxxh in hw2 only. Later versions have it moved to the "RTC WLAN" area (at 004xxxh or 005xxxh), see there for details.
ATH:028244h (mirror of 0040F4h) - MAC_PCU_REG_SLP32_MODE (ini:10F424h) ;hw2
ATH:028248h (mirror of 0040F8h) - MAC_PCU_REG_SLP32_WAKE (ini:07EFh) ;hw2
ATH:02824Ch (mirror of 0040FCh) - MAC_PCU_REG_SLP32_TSF_INC (ini:1E848h) ;hw2
ATH:028250h (mirror of 004100h) - MAC_PCU_REG_SLPMIB1 ;hw2
ATH:028254h (mirror of 004104h) - MAC_PCU_REG_SLPMIB2 ;hw2
ATH:028258h (mirror of 004108h) - MAC_PCU_REG_SLPMIB3 ;hw2
ATH:028264h (mirror of 00410Ch) - MAC_PCU_REG_SLP5 (ini: 0FFFFFFh) ;hw2
These hw2 registers seem to be just mirrors of other hw2 registers in the RTC area at 004xxxh (see RTC WLAN chapter for details).
In hw4/hw6, the mirrors at 028xxxh are removed (and only the registers at 004xxxh are kept; whereas, in hw6 that part moved to 005xxxh).

     __________________________ outcommented hw2 stuff __________________________

Below outcommented stuff is found in hw2 source code, maybe it was used in older hw2 revisions (in case there multiple hw2 revisions), or maybe it was used in even older pre-hw2 chips, or maybe it's just some experimental stuff that was never implemented in hardware.
ATH:028140h - outcommented:MAC_PCU_REG_TSFCAL ;Misc ;hw2

      0-3    outcommented:COUNT          (hw2: ini:8)       ;\
      4-7    outcommented:INTERVAL       (hw2: ini:0Ah)     ; hw2 only
      8      outcommented:ENABLE         (hw2: ini:1)       ; (although it's
      9      outcommented:AUTO_CAL       (hw2: ini:1)       ; outcommented even
      10     outcommented:VALUE_WE       (hw2: ini:0)       ; in hw2 source code)
      16-31  outcommented:VALUE          (hw2: ini:8000h)   ;/

ATH:02814Ch - outcommented:MAC_PCU_REG_SYNC2 ;Misc ;hw2

      0-7    outcommented:TIME_OFFSET     (hw2: ini:0)
      8      outcommented:MASTER          (hw2: ini:0)
      9      outcommented:REPLACE         (hw2: ini:0)
      10     outcommented:TUNE            (hw2: ini:0)
      11     outcommented:CLEAR           (hw2: ini:0)
      16-31  outcommented:INTR_THRESH     (hw2: ini:FFFFh)

ATH:028148h - outcommented:MAC_PCU_REG_SYNC1 ;Time (ini:0) ;hw2
ATH:028158h - outcommented:MAC_PCU_REG_SYNC5 ;RX Time ;hw2
ATH:028160h - outcommented:MAC_PCU_REG_SYNC7 ;Last Time ;hw2
ATH:028164h - outcommented:MAC_PCU_REG_SYNC8 ;Updated Time ;hw2

      0-30   outcommented:TIME
      31     -

ATH:028150h - outcommented:MAC_PCU_REG_SYNC3 ;MCAST Addr_L ;hw2
ATH:028154h - outcommented:MAC_PCU_REG_SYNC4 ;MCAST Addr_U ;hw2

      0-47   outcommented:MCAST_ADDR      (hw2: ini:0)
      48-63  -

ATH:02815Ch - outcommented:MAC_PCU_REG_SYNC6 ;INC ;hw2

      0-31   outcommented:INC

DSi Atheros Wifi - Internal I/O - 029800h - BB Baseband (hw4/hw6)

ATH:029800h/02A360h - BB_TEST_CONTROLS ;hw4/hw6

      0-3    CF_TSTTRIG_SEL
      4      CF_TSTTRIG
      5-6    CF_RFSHIFT_SEL
      8-9    CARDBUS_MODE
      10     CLKOUT_IS_CLK32
      13     ENABLE_RFSILENT_BB
      15     ENABLE_MINI_OBS
      17     SLOW_CLK160
      18     AGC_OBS_SEL_3
      19-22  CF_BBB_OBS_SEL
      23     RX_OBS_SEL_5TH_BIT
      24     AGC_OBS_SEL_4
      28     FORCE_AGC_CLEAR
      30-31  TSTDAC_OUT_SEL

ATH:029804h/02A204h - BB_GEN_CONTROLS ;hw4/hw6

      0      TURBO
      1      CF_SHORT20
      2      DYN_20_40
      3      DYN_20_40_PRI_ONLY
      4      DYN_20_40_PRI_CHN
      5      DYN_20_40_EXT_CHN
      6      HT_ENABLE
      7      ALLOW_SHORT_GI
      8      CF_2_CHAINS_USE_WALSH
      9      hw4: CF_SINGLE_HT_LTF1                         ;-hw4
      9      hw6: CF_3_CHAINS_USE_WALSH                     ;-hw6
      10     GF_ENABLE
      11     hw4: BYPASS_DAC_FIFO_N                         ;-hw4
      11     hw6: ENABLE_DAC_ASYNC_FIFO                     ;\
      14     hw6: BOND_OPT_CHAIN_SEL                        ;
      15     hw6: STATIC20_MODE_HT40_PACKET_HANDLING        ;
      16     hw6: STATIC20_MODE_HT40_PACKET_ERROR_RPT       ; hw6
      17     hw6: ENABLE_CSD_PHASE_DITHERING                ;
      18-24  hw6: UNSUPP_HT_RATE_THRESHOLD                  ;
      25     hw6: EN_ERR_TX_CHAIN_MASK_ZERO                 ;
      26     hw6: IS_MCKINLEY_TPC                           ;/

ATH:029808h/02A364h - BB_TEST_CONTROLS_STATUS ;hw4/hw6

      0      CF_TSTDAC_EN
      1      CF_TX_SRC_IS_TSTDAC
      2-4    CF_TX_OBS_SEL
      5-6    CF_TX_OBS_MUX_SEL
      7      CF_TX_SRC_ALTERNATE
      8      CF_TSTADC_EN
      9      CF_RX_SRC_IS_TSTADC
      10-13  RX_OBS_SEL
      14     DISABLE_A2_WARM_RESET
      15     RESET_A2
      16-18  AGC_OBS_SEL
      19     CF_ENABLE_FFT_DUMP
      23     CF_DEBUGPORT_IN
      27     DISABLE_AGC_TO_A2
      28     CF_DEBUGPORT_EN
      29-30  CF_DEBUGPORT_SEL

ATH:02980Ch/029800h - BB_TIMING_CONTROLS_1 ;hw4/hw6

      0-6    STE_THR
      7-12   STE_TO_LONG1
      13-16  TIMING_BACKOFF
      17     ENABLE_HT_FINE_PPM
      18-19  HT_FINE_PPM_STREAM
      20-21  HT_FINE_PPM_QAM
      22     ENABLE_LONG_CHANFIL
      23     ENABLE_RX_STBC
      24     ENABLE_CHANNEL_FILTER
      25-26  FALSE_ALARM
      27     ENABLE_LONG_RESCALE
      28     TIMING_LEAK_ENABLE
      29-30  COARSE_PPM_SELECT
      31     FFT_SCALING

ATH:029810h/029804h - BB_TIMING_CONTROLS_2 ;hw4/hw6

      0-11   FORCED_DELTA_PHI_SYMBOL
      12     FORCE_DELTA_PHI_SYMBOL
      13     ENABLE_MAGNITUDE_TRACK
      14     ENABLE_SLOPE_FILTER
      15     ENABLE_OFFSET_FILTER
      16-22  DC_OFF_DELTAF_THRES
      24-26  DC_OFF_TIM_CONST
      27     ENABLE_DC_OFFSET
      28     ENABLE_DC_OFFSET_TRACK
      29     ENABLE_WEIGHTING
      30     TRACEBACK128
      31     ENABLE_HT_FINE_TIMING

ATH:029814h/029808h - BB_TIMING_CONTROLS_3 ;hw4/hw6

      0-7    PPM_RESCUE_INTERVAL
      8      ENABLE_PPM_RESCUE
      9      ENABLE_FINE_PPM
      10     ENABLE_FINE_INTERP
      11     CONTINUOUS_PPM_RESCUE
      12     ENABLE_DF_CHANEST
      13-16  DELTA_SLOPE_COEF_EXP
      17-31  DELTA_SLOPE_COEF_MAN

ATH:029818h/02A200h - BB_D2_CHIP_ID (R) ;hw4/hw6

      0-7    OLD_ID            (R)
      8-31   ID                (R)

ATH:02981Ch/02A20Ch - BB_ACTIVE ;hw4/hw6

      0      CF_ACTIVE

ATH:029820h/02A258h - BB_TX_TIMING_1 ;hw4/hw6

      0-7    TX_FRAME_TO_ADC_OFF
      8-15   TX_FRAME_TO_A2_RX_OFF
      16-23  TX_FRAME_TO_DAC_ON
      24-31  TX_FRAME_TO_A2_TX_ON

ATH:029824h/02A25Ch - BB_TX_TIMING_2 ;hw4/hw6

      0-7    TX_FRAME_TO_TX_D_START
      8-15   TX_FRAME_TO_PA_ON
      16-23  TX_END_TO_PA_OFF
      24-31  TX_END_TO_A2_TX_OFF

ATH:029828h/02A260h - BB_TX_TIMING_3 ;hw4/hw6

      0-7    TX_END_TO_DAC_OFF
      8-15   TX_FRAME_TO_THERM_CHAIN_ON
      16-23  TX_END_TO_A2_RX_ON
      24-31  TX_END_TO_ADC_ON

ATH:02982Ch/02A350h - BB_ADDAC_PARALLEL_CONTROL ;hw4/hw6

      12     OFF_DACLPMODE
      13     OFF_PWDDAC
      15     OFF_PWDADC
      28     ON_DACLPMODE
      29     ON_PWDDAC
      31     ON_PWDADC

ATH:029834h/02A264h - BB_XPA_TIMING_CONTROL ;hw4/hw6

      0-7    TX_FRAME_TO_XPAA_ON
      8-15   TX_FRAME_TO_XPAB_ON
      16-23  TX_END_TO_XPAA_OFF
      24-31  TX_END_TO_XPAB_OFF

ATH:029838h/02A280h - BB_MISC_PA_CONTROL ;hw4/hw6

      0      XPAA_ACTIVE_HIGH
      1      XPAB_ACTIVE_HIGH
      2      ENABLE_XPAA
      3      ENABLE_XPAB

ATH:02983Ch/0298A4h - BB_TSTDAC_CONSTANT ;hw4/hw6

      0-10   CF_TSTDAC_CONSTANT_I
      11-21  CF_TSTDAC_CONSTANT_Q

ATH:029840h/029820h - BB_FIND_SIGNAL_LOW ;hw4/hw6

      0-5    RELSTEP_LOW
      6-11   FIRSTEP_LOW
      12-19  FIRPWR_LOW
      20-23  YCOK_MAX_LOW
      24-30  LONG_SC_THRESH

ATH:029844h/029E00h - BB_SETTLING_TIME ;hw4/hw6

      0-6    AGC_SETTLING
      7-13   SWITCH_SETTLING
      14-19  ADCSAT_THRL
      20-25  ADCSAT_THRH
      26-29  LBRESET_ADVANCE

ATH:029848h/029E04h - BB_GAIN_FORCE_MAX_GAINS_B0 ;hw4/hw6
ATH:02A848h/02AE04h - BB_GAIN_FORCE_MAX_GAINS_B1 ;hw4/hw6

      7-13   hw4: XATTEN1_HYST_MARGIN_0/1   ;\      ;\separate settings in B0/B1
      14-20  hw4: XATTEN2_HYST_MARGIN_0/1   ; hw4   ;/
      21     hw4: GAIN_FORCE                ;       ;\global setting (not in B1)
      31     hw4: ENABLE_SHARED_RX          ;/      ;/
      0-7    hw6: RF_GAIN_F_0/1             ;\      ;\
      8-15   hw6: MB_GAIN_F_0/1             ;       ;
      16     hw6: XATTEN1_SW_F_0/1          ; hw6   ; separate settings in B0/B1
      17     hw6: XATTEN2_SW_F_0/1          ;       ;
      18-24  hw6: XATTEN1_HYST_MARGIN_0/1   ;       ;
      25-31  hw6: XATTEN2_HYST_MARGIN_0/1   ;/      ;/

ATH:02984Ch - BB_GAINS_MIN_OFFSETS_B0 ;hw4
ATH:02A84Ch - BB_GAINS_MIN_OFFSETS_B1 ;hw4
ATH:029E08h - BB_GAINS_MIN_OFFSETS ;hw6 (only global setting for B0 and B1)

      0-6    OFFSETC1                       ;\              ;\global setting
      7-11   OFFSETC2                       ; hw4/hw6       ; (not in B1 register)
      12-16  OFFSETC3                       ;/              ;/
      17-24  hw4: RF_GAIN_F_0/1             ;\              ;\separate settings
      25     hw4: XATTEN1_SW_F_0/1          ; hw4           ; in B0/B1 registers
      26     hw4: XATTEN2_SW_F_0/1          ;/              ;/
      17     hw6: GAIN_FORCE                ;\              ;\
      18     hw6: CF_AGC_HIST_ENABLE        ;               ; global setting
      19     hw6: CF_AGC_HIST_GC            ; hw6           ; (hw6 doesn't have
      20     hw6: CF_AGC_HIST_VOTING        ;               ; a B1 register at all)
      21     hw6: CF_AGC_HIST_PHY_ERR       ;/              ;/

ATH:029850h/029E0Ch - BB_DESIRED_SIGSIZE ;hw4/hw6

      0-7    ADC_DESIRED_SIZE
      20-27  TOTAL_DESIRED
      28-29  INIT_GC_COUNT_MAX
      30     REDUCE_INIT_GC_COUNT
      31     ENA_INIT_GAIN

ATH:029854h/029C00h - BB_TIMING_CONTROL_3A ;hw4/hw6

      0-6    STE_THR_HI_RSSI                        ;-hw4/hw6
      7      hw6: USE_HTSIG1_20_40_BW_VALUE         ;-hw6

ATH:029858h/029E10h - BB_FIND_SIGNAL ;hw4/hw6

      0-5    RELSTEP
      6-11   RELPWR
      12-17  FIRSTEP
      18-25  FIRPWR
      26-31  M1COUNT_MAX

ATH:02985Ch/029E14h - BB_AGC ;hw4/hw6

      0-6    COARSEPWR_CONST
      7-14   COARSE_LOW
      15-21  COARSE_HIGH
      22-29  QUICK_DROP
      30-31  RSSI_OUT_SELECT

ATH:029860h/02A2C4h - BB_AGC_CONTROL ;hw4/hw6

      0      DO_CALIBRATE
      1      DO_NOISEFLOOR
      3-5    MIN_NUM_GAIN_CHANGE
      6-9    YCOK_MAX
      10     LEAKY_BUCKET_ENABLE
      11     CAL_ENABLE
      12     USE_TABLE_SEED
      13     AGC_UPDATE_TABLE_SEED
      15     ENABLE_NOISEFLOOR
      16     ENABLE_FLTR_CAL
      17     NO_UPDATE_NOISEFLOOR
      18     EXTEND_NF_PWR_MEAS
      19     CLC_SUCCESS                    (R)
      20     ENABLE_PKDET_CAL

ATH:029864h/029E1Ch - BB_CCA_B0 ;hw4/hw6
ATH:02AE1Ch - BB_CCA_B1 ;hw6

      0-8    CF_MAXCCAPWR_0                         ;-separate settings (on hw6)
      9-11   CF_CCA_COUNT_MAXC                      ;\global setting (not in B1)
      12-19  CF_THRESH62                            ;/
      20-28  MINCCAPWR_0                        (R) ;-separate settings (on hw6)

ATH:029868h/029824h - BB_SFCORR ;hw4/hw6

      0-4    M2COUNT_THR
      5-10   ADCSAT_THRESH
      11-16  ADCSAT_ICOUNT
      17-23  M1_THRES
      24-30  M2_THRES

ATH:02986Ch/029828h - BB_SELF_CORR_LOW ;hw4/hw6

      0      USE_SELF_CORR_LOW
      1-7    M1COUNT_MAX_LOW
      8-13   M2COUNT_THR_LOW
      14-20  M1_THRESH_LOW
      21-27  M2_THRESH_LOW

ATH:029874h/02A340h - BB_SYNTH_CONTROL ;hw4/hw6

      0-16   RFCHANFRAC
      17-25  RFCHANNEL
      26-27  RFAMODEREFSEL
      28     RFFRACMODE
      29     RFBMODE
      30     RFSYNTH_CTRL_SSHIFT

ATH:029878h/02A344h - BB_ADDAC_CLK_SELECT ;hw4/hw6

      2-3    BB_DAC_CLK_SELECT
      4-5    BB_ADC_CLK_SELECT

ATH:02987Ch/02A348h - BB_PLL_CNTL ;hw4/hw6

      0-9    BB_PLL_DIV
      10-13  BB_PLL_REFDIV
      14-15  BB_PLL_CLK_SEL
      16     BB_PLLBYPASS
      17-27  BB_PLL_SETTLE_TIME

ATH:029900h/02A220h - BB_VIT_SPUR_MASK_A ;CF_PUNC_MASK_A ;hw4/hw6
ATH:029904h/02A224h - BB_VIT_SPUR_MASK_B ;CF_PUNC_MASK_B ;hw4/hw6

      0-9    CF_PUNC_MASK_A     / CF_PUNC_MASK_B
      10-16  CF_PUNC_MASK_IDX_A / CF_PUNC_MASK_IDX_B

ATH:029908h/029C0Ch - BB_PILOT_SPUR_MASK ;CF_PILOT_MASK_A/B ;hw4/hw6
ATH:02990Ch/029C10h - BB_CHAN_SPUR_MASK ;CF_CHAN_MASK_A/B ;hw4/hw6

      0-4    CF_PILOT_MASK_A     / CF_CHAN_MASK_A
      5-11   CF_PILOT_MASK_IDX_A / CF_CHAN_MASK_IDX_A
      12-16  CF_PILOT_MASK_B     / CF_CHAN_MASK_B
      17-23  CF_PILOT_MASK_IDX_B / CF_CHAN_MASK_IDX_B

ATH:029910h/02A228h - BB_SPECTRAL_SCAN ;hw4/hw6

      0      SPECTRAL_SCAN_ENA
      1      SPECTRAL_SCAN_ACTIVE
      2      DISABLE_RADAR_TCTL_RST
      3      DISABLE_PULSE_COARSE_LOW
      4-7    SPECTRAL_SCAN_FFT_PERIOD
      8-15   SPECTRAL_SCAN_PERIOD
      16-27  SPECTRAL_SCAN_COUNT
      28     SPECTRAL_SCAN_SHORT_RPT
      29     SPECTRAL_SCAN_PRIORITY
      30     SPECTRAL_SCAN_USE_ERR5
      31     hw6: SPECTRAL_SCAN_COMPRESSED_RPT      ;-hw6

ATH:02A248h - BB_SPECTRAL_SCAN_2 ;hw6

      0      hw6: SPECTRAL_SCAN_RPT_MODE            ;\hw6
      1-8    hw6: SPECTRAL_SCAN_NOISE_FLOOR_REF     ;/

ATH:029914h/02A254h - BB_ANALOG_POWER_ON_TIME ;hw4/hw6

      0-13   ACTIVE_TO_RECEIVE

ATH:029918h/02A230h - BB_SEARCH_START_DELAY ;hw4/hw6

      0-11   SEARCH_START_DELAY
      12     ENABLE_FLT_SVD
      13     ENABLE_SEND_CHAN
      14     hw6: RX_SOUNDING_ENABLE
      15     hw6: RM_HCSD4SVD

ATH:02991Ch/02A234h - BB_MAX_RX_LENGTH ;hw4/hw6

      0-11   MAX_RX_LENGTH
      12-29  MAX_HT_LENGTH

ATH:029920h/02980Ch - BB_TIMING_CONTROL_4 ;hw4/hw6

      12-15  CAL_LG_COUNT_MAX
      16     DO_GAIN_DC_IQ_CAL
      17-20  USE_PILOT_TRACK_DF
      21-27  EARLY_TRIGGER_THR
      28     ENABLE_PILOT_MASK
      29     ENABLE_CHAN_MASK
      30     ENABLE_SPUR_FILTER
      31     ENABLE_SPUR_RSSI

ATH:029924h/029810h - BB_TIMING_CONTROL_5 ;hw4/hw6

      0      ENABLE_CYCPWR_THR1
      1-7    CYCPWR_THR1
      15     ENABLE_RSSI_THR1A
      16-22  RSSI_THR1A
      23-29  LONG_SC_THRESH_HI_RSSI
      30     FORCED_AGC_STR_PRI
      31     FORCED_AGC_STR_PRI_EN

ATH:029928h/02A7D0h - BB_PHYONLY_WARM_RESET ;hw4/hw6

      0      PHYONLY_RST_WARM_L

ATH:02992Ch/02A7D4h - BB_PHYONLY_CONTROL ;hw4/hw6

      0      RX_DRAIN_RATE
      1      LATE_TX_SIGNAL_SYMBOL
      2      GENERATE_SCRAMBLER
      3      TX_ANTENNA_SELECT
      4      STATIC_TX_ANTENNA
      5      RX_ANTENNA_SELECT
      6      STATIC_RX_ANTENNA
      7      EN_LOW_FREQ_SLEEP

ATH:02993Ch/02A3F0h - BB_POWERTX_MAX ;hw4/hw6

      6      USE_PER_PACKET_POWERTX_MAX
      7      hw6: USE_PER_PACKET_OLPC_GAIN_DELTA_ADJ

ATH:029940h/02983Ch - BB_EXTENSION_RADAR ;hw4/hw6

      8-13   BLOCKER40_MAX_RADAR
      14     ENABLE_EXT_RADAR
      15-22  RADAR_DC_PWR_THRESH
      23-30  RADAR_LB_DC_CAP
      31     DISABLE_ADCSAT_HOLD

ATH:029944h/02A238h - BB_FRAME_CONTROL ;hw4/hw6

      0-1    CF_OVERLAP_WINDOW
      2      CF_SCALE_SHORT
      3-5    CF_TX_CLIP
      6-7    CF_TX_DOUBLESAMP_DAC
      8-15   TX_END_ADJUST
      16     PREPEND_CHAN_INFO
      17     SHORT_HIGH_PAR_NORM
      18     EN_ERR_GREEN_FIELD
      19     hw4: EN_ERR_XR_POWER_RATIO
      19     hw6: EN_ERR_STATIC20_MODE_HT40_PACKET
      20     EN_ERR_OFDM_XCORR
      21     EN_ERR_LONG_SC_THR
      22     EN_ERR_TIM_LONG1
      23     EN_ERR_TIM_EARLY_TRIG
      24     EN_ERR_TIM_TIMEOUT
      25     EN_ERR_SIGNAL_PARITY
      26     EN_ERR_RATE_ILLEGAL
      27     EN_ERR_LENGTH_ILLEGAL
      28     hw4: EN_ERR_HT_SERVICE
      28     hw6: NO_6MBPS_SERVICE_ERR
      29     EN_ERR_SERVICE
      30     EN_ERR_TX_UNDERRUN
      31     EN_ERR_RX_ABORT

ATH:029948h/029814h - BB_TIMING_CONTROL_6 ;hw4/hw6

      0-7    HI_RSSI_THRESH
      8-14   EARLY_TRIGGER_THR_HI_RSSI
      15-20  OFDM_XCORR_THRESH
      21-27  OFDM_XCORR_THRESH_HI_RSSI
      28-31  LONG_MEDIUM_RATIO_THR

ATH:02994Ch/02981Ch - BB_SPUR_MASK_CONTROLS ;hw4/hw6

      0-7    SPUR_RSSI_THRESH
      8      EN_VIT_SPUR_RSSI
      17     ENABLE_MASK_PPM
      18-25  MASK_RATE_CNTL
      26     hw6: ENABLE_NF_RSSI_SPUR_MIT

ATH:029950h/0298DCh - BB_RX_IQ_CORR_B0 ;hw4/hw6
ATH:02A8DCh - BB_RX_IQ_CORR_B1 ;hw6

      0-6    RX_IQCORR_Q_Q_COFF_0/1         ;\separate settings (on hw6)
      7-13   RX_IQCORR_Q_I_COFF_0/1         ;/
      14     RX_IQCORR_ENABLE               ;-global setting (not in B1)
      15-21  LOOPBACK_IQCORR_Q_Q_COFF_0/1   ;\separate settings (on hw6)
      22-28  LOOPBACK_IQCORR_Q_I_COFF_0/1   ;/
      29     LOOPBACK_IQCORR_ENABLE         ;-global setting (not in B1)

ATH:029954h/029834h - BB_RADAR_DETECTION ;hw4/hw6

      0      PULSE_DETECT_ENABLE
      1-5    PULSE_IN_BAND_THRESH
      6-11   PULSE_RSSI_THRESH
      12-17  PULSE_HEIGHT_THRESH
      18-23  RADAR_RSSI_THRESH
      24-30  RADAR_FIRPWR_THRESH
      31     ENABLE_RADAR_FFT

ATH:029958h/029838h - BB_RADAR_DETECTION_2 ;hw4/hw6

      0-7    RADAR_LENGTH_MAX
      8-12   PULSE_RELSTEP_THRESH
      13     ENABLE_PULSE_RELSTEP_CHECK
      14     ENABLE_MAX_RADAR_RSSI
      15     ENABLE_BLOCK_RADAR_CHECK
      16-21  RADAR_RELPWR_THRESH
      22     RADAR_USE_FIRPWR_128
      23     ENABLE_RADAR_RELPWR_CHECK
      24-26  CF_RADAR_BIN_THRESH_SEL
      27     ENABLE_PULSE_GC_COUNT_CHECK

ATH:02995Ch/0298D0h - BB_TX_PHASE_RAMP_B0 ;hw4/hw6
ATH:02A8D0h - BB_TX_PHASE_RAMP_B1 ;hw6

      0      CF_PHASE_RAMP_ENABLE
      1-6    CF_PHASE_RAMP_BIAS
      7-16   CF_PHASE_RAMP_INIT
      17-24  CF_PHASE_RAMP_ALPHA

ATH:029960h/02A284h - BB_SWITCH_TABLE_CHN_B0 ;hw4/hw6
ATH:02B284h - BB_SWITCH_TABLE_CHN_B1 ;hw6

      0-1    SWITCH_TABLE_IDLE
      2-3    SWITCH_TABLE_T
      4-5    SWITCH_TABLE_R
      6-7    SWITCH_TABLE_RX1
      8-9    SWITCH_TABLE_RX12
      10-11  SWITCH_TABLE_B

ATH:029964h/02A288h - BB_SWITCH_TABLE_COM1 ;hw4/hw6

      0-3    SWITCH_TABLE_COM_IDLE
      4-7    SWITCH_TABLE_COM_T1
      8-11   SWITCH_TABLE_COM_T2
      12-15  SWITCH_TABLE_COM_B
      16-19  hw6: SWITCH_TABLE_COM_IDLE_ALT         ;\hw6
      20-23  hw6: SWITCH_TABLE_COM_SPDT             ;/

ATH:029968h/029E20h - BB_CCA_CTRL_2_B0 ;hw4/hw6
ATH:02AE20h - BB_CCA_CTRL_2_B1 ;hw6

      0-8    MINCCAPWR_THR_0/1              ;-separate settings (on hw6)
      9      ENABLE_MINCCAPWR_THR           ;-global setting (not in B1)
      10-17  NF_GAIN_COMP_0/1               ;-separate settings (on hw6)
      18     THRESH62_MODE                  ;-global setting (not in B1)

ATH:02996Ch/02A28Ch - BB_SWITCH_TABLE_COM2 ;hw4/hw6

      0-3    hw4: SWITCH_TABLE_COM_RA1NXAL1         ;\
      4-7    hw4: SWITCH_TABLE_COM_RA2NXAL1         ;
      8-11   hw4: SWITCH_TABLE_COM_RA1XAL1          ;
      12-15  hw4: SWITCH_TABLE_COM_RA2XAL1          ; hw4
      16-19  hw4: SWITCH_TABLE_COM_RA1NXAL2         ;
      20-23  hw4: SWITCH_TABLE_COM_RA2NXAL2         ;
      24-27  hw4: SWITCH_TABLE_COM_RA1XAL2          ;
      28-31  hw4: SWITCH_TABLE_COM_RA2XAL2          ;/
      0-3    hw6: SWITCH_TABLE_COM_RA1L1            ;\
      4-7    hw6: SWITCH_TABLE_COM_RA2L1            ;
      8-11   hw6: SWITCH_TABLE_COM_RA1L2            ; hw6
      12-15  hw6: SWITCH_TABLE_COM_RA2L2            ;
      16-19  hw6: SWITCH_TABLE_COM_RA12             ;/

ATH:029970h/029E24h - BB_RESTART ;hw4/hw6

      0      ENABLE_RESTART
      1-5    RESTART_LGFIRPWR_DELTA
      6      ENABLE_PWR_DROP_ERR
      7-11   PWRDROP_LGFIRPWR_DELTA
      12-17  OFDM_CCK_RSSI_BIAS
      18-20  ANT_FAST_DIV_GC_LIMIT
      21     ENABLE_ANT_FAST_DIV_M2FLAG
      22-28  WEAK_RSSI_VOTE_THR
      29     ENABLE_PWR_DROP_ERR_CCK
      30     DISABLE_DC_RESTART
      31     RESTART_MODE_BW40

ATH:029978h/02A390h - BB_SCRAMBLER_SEED ;hw4/hw6

      0-6    FIXED_SCRAMBLER_SEED

ATH:02997Ch/02A23Ch - BB_RFBUS_REQUEST ;hw4/hw6

      0      RFBUS_REQUEST

ATH:0299A0h/029818h - BB_TIMING_CONTROL_11 ;hw4/hw6

      0-19   SPUR_DELTA_PHASE
      20-29  SPUR_FREQ_SD
      30     USE_SPUR_FILTER_IN_AGC
      31     USE_SPUR_FILTER_IN_SELFCOR

ATH:0299A4h/02A2A0h - BB_MULTICHAIN_ENABLE ;hw4/hw6

      0-2    RX_CHAIN_MASK

ATH:0299A8h/029880h - BB_MULTICHAIN_CONTROL ;hw4/hw6

      0      FORCE_ANALOG_GAIN_DIFF
      1-7    FORCED_GAIN_DIFF_01
      8      SYNC_SYNTHON
      9      USE_POSEDGE_REFCLK
      10-20  CF_SHORT_SAT
      22-28  FORCED_GAIN_DIFF_02
      29     FORCE_SIGMA_ZERO

ATH:0299ACh/029E28h - BB_MULTICHAIN_GAIN_CTRL ;hw4/hw6

      0-7    QUICKDROP_LOW
      8      ENABLE_CHECK_STRONG_ANT
      9-14   ANT_FAST_DIV_BIAS
      15-20  CAP_GAIN_RATIO_SNR
      21     CAP_GAIN_RATIO_ENA
      22     CAP_GAIN_RATIO_MODE
      23     ENABLE_ANT_SW_RX_PROT
      24     ENABLE_ANT_DIV_LNADIV
      25-26  ANT_DIV_ALT_LNACONF
      27-28  ANT_DIV_MAIN_LNACONF
      29     ANT_DIV_ALT_GAINTB
      30     ANT_DIV_MAIN_GAINTB

ATH:0299B4h/0298D4h - BB_ADC_GAIN_DC_CORR_B0 ;hw4/hw6
ATH:02A8D4h - BB_ADC_GAIN_DC_CORR_B1 ;hw6

      0-5    ADC_GAIN_CORR_Q_COEFF_0/1      ;\
      6-11   ADC_GAIN_CORR_I_COEFF_0/1      ; separate settings (on hw6)
      12-20  ADC_DC_CORR_Q_COEFF_0/1        ;
      21-29  ADC_DC_CORR_I_COEFF_0/1        ;/
      30     ADC_GAIN_CORR_ENABLE           ;\global setting (not in B1)
      31     ADC_DC_CORR_ENABLE             ;/

ATH:0299B8h/029E2Ch - BB_EXT_CHAN_PWR_THR_1 ;hw4/hw6

      0-7    THRESH62_EXT
      8-15   ANT_DIV_ALT_ANT_MINGAINIDX
      16-20  ANT_DIV_ALT_ANT_DELTAGAINIDX
      21-26  ANT_DIV_ALT_ANT_DELTANF

ATH:0299BCh/029830h - BB_EXT_CHAN_PWR_THR_2_B0 ;hw4/hw6
ATH:02A830h - BB_EXT_CHAN_PWR_THR_2_B1 ;hw6

      0-8    CF_MAXCCAPWR_EXT_0/1           ;-separate settings (on hw6)
      9-15   CYCPWR_THR1_EXT                ;-global setting (not in B1)
      16-24  MINCCAPWR_EXT_0/1         (R)  ;-separate settings (on hw6)

ATH:0299C0h/02982Ch - BB_EXT_CHAN_SCORR_THR ;hw4/hw6

      0-6    M1_THRES_EXT
      7-13   M2_THRES_EXT
      14-20  M1_THRES_LOW_EXT
      21-27  M2_THRES_LOW_EXT
      28     SPUR_SUBCHANNEL_SD

ATH:0299C4h/029E30h - BB_EXT_CHAN_DETECT_WIN ;hw4/hw6

      0-3    DET_DIFF_WIN_WEAK
      4-7    DET_DIFF_WIN_WEAK_LOW
      8-12   DET_DIFF_WIN_WEAK_CCK
      13-15  DET_20H_COUNT
      16-18  DET_EXT_BLK_COUNT
      19-24  WEAK_SIG_THR_CCK_EXT
      25-28  DET_DIFF_WIN_THRESH

ATH:0299C8h/029E34h - BB_PWR_THR_20_40_DET ;hw4/hw6

      0-4    PWRDIFF40_THRSTR
      5-10   BLOCKER40_MAX
      11-15  DET40_PWRSTEP_MAX
      16-23  DET40_THR_SNR
      24-28  DET40_PRI_BIAS
      29     PWRSTEP40_ENA
      30     LOWSNR40_ENA

ATH:0299D0h/029C14h - BB_SHORT_GI_DELTA_SLOPE ;hw4/hw6

      0-3    DELTA_SLOPE_COEF_EXP_SHORT_GI
      4-18   DELTA_SLOPE_COEF_MAN_SHORT_GI

ATH:0299DCh/02A370h - BB_CHANINFO_CTRL ;hw4/hw6

      0      CAPTURE_CHAN_INFO
      1      DISABLE_CHANINFOMEM
      2      hw6: CAPTURE_SOUNDING_PACKET
      3      hw6: CHANINFOMEM_S2_READ

ATH:0299E0h/02A3A4h - BB_HEAVY_CLIP_CTRL ;hw4/hw6

      0-8    CF_HEAVY_CLIP_ENABLE
      9      PRE_EMP_HT40_ENABLE
      10-17  hw6: HEAVY_CLIP_FACTOR_XR   ;-hw6 (moved from hw4's BB_RIFS_SRCH)

ATH:0299E4h/02A3A8h - BB_HEAVY_CLIP_20 ;FACTOR_0..3 ;hw4/hw6
ATH:0299E8h/02A3ACh - BB_HEAVY_CLIP_40 ;FACTOR_4..7 ;hw4/hw6

      0-7    HEAVY_CLIP FACTOR_0 / FACTOR_4
      8-15   HEAVY_CLIP FACTOR_1 / FACTOR_5
      16-23  HEAVY_CLIP FACTOR_2 / FACTOR_6
      24-31  HEAVY_CLIP FACTOR_3 / FACTOR_7

ATH:0299ECh/029E38h - BB_RIFS_SRCH ;hw4/hw6

      0-7    hw4: HEAVY_CLIP_FACTOR_XR   ;-hw4 (moved to BB_HEAVY_CLIP_CTRL in hw6)
      8-15   INIT_GAIN_DB_OFFSET
      16-25  RIFS_INIT_DELAY
      26     RIFS_DISABLE_PWRLOW_GC
      27     RIFS_DISABLE_CCK_DET

ATH:0299F0h/02A2C8h - BB_IQ_ADC_CAL_MODE ;hw4/hw6

      0-1    GAIN_DC_IQ_CAL_MODE
      2      TEST_CALADCOFF

ATH:0299FCh/029884h - BB_PER_CHAIN_CSD ;hw4/hw6

      0-4    CSD_CHN1_2CHAINS
      5-9    CSD_CHN1_3CHAINS
      10-14  CSD_CHN2_3CHAINS

ATH:029A00h..029BFCh - BB_RX_OCGAIN[0..127] (W) ;hw4
ATH:02A000h..02A1FCh - BB_RX_OCGAIN[0..127] (R/W?) ;hw6
ATH:02AA00h..02ABFCh - BB_RX_OCGAIN2[0..127] (W) ;hw4
ATH:02B000h..02B1FCh - BB_RX_OCGAIN2[0..127] (R/W?) ;hw6

      0-31   GAIN_ENTRY

ATH:029C00h/0298A0h - BB_TX_CRC (R) ;hw4/hw6

      0-15   TX_CRC                         (R)

ATH:029C10h/0298C0h - BB_IQ_ADC_MEAS_0_B0 (R) ;hw4/hw6
ATH:029C14h/0298C4h - BB_IQ_ADC_MEAS_1_B0 (R) ;hw4/hw6
ATH:029C18h/0298C8h - BB_IQ_ADC_MEAS_2_B0 (R) ;hw4/hw6
ATH:029C1Ch/0298CCh - BB_IQ_ADC_MEAS_3_B0 (R) ;hw4/hw6
ATH:02A8C0h - BB_IQ_ADC_MEAS_0_B1 (R) ;hw6
ATH:02A8C4h - BB_IQ_ADC_MEAS_1_B1 (R) ;hw6
ATH:02A8C8h - BB_IQ_ADC_MEAS_2_B1 (R) ;hw6
ATH:02A8CCh - BB_IQ_ADC_MEAS_3_B1 (R) ;hw6

      0-31   GAIN_DC_IQ_CAL_MEAS            (R)

ATH:029C20h/02A240h - BB_RFBUS_GRANT (R) ;hw4/hw6

      0      RFBUS_GRANT                    (R)
      1      BT_ANT                         (R)

ATH:029C24h/029C20h - BB_TSTADC (R) ;hw4/hw6

      0-9    TSTADC_OUT_Q                   (R)
      10-19  TSTADC_OUT_I                   (R)

ATH:029C28h/02A368h - BB_TSTDAC (R) ;hw4/hw6

      0-9    TSTDAC_OUT_Q                   (R)
      10-19  TSTDAC_OUT_I                   (R)

ATH:029C30h/02A3B0h - BB_ILLEGAL_TX_RATE (R) ;hw4/hw6

      0      ILLEGAL_TX_RATE                (R)

ATH:029C34h/0298A8h - BB_SPUR_REPORT_B0 (R) ;hw4/hw6
ATH:02A8A8h - BB_SPUR_REPORT_B1 (R) ;hw6

      0-7    SPUR_EST_I                     (R)
      8-15   SPUR_EST_Q                     (R)
      16-31  POWER_WITH_SPUR_REMOVED        (R)

ATH:029C38h/02A36Ch - BB_CHANNEL_STATUS (R) ;hw4/hw6

      0      BT_ACTIVE                      (R)
      1      RX_CLEAR_RAW                   (R)
      2      RX_CLEAR_MAC                   (R)
      3      RX_CLEAR_PAD                   (R)
      4-5    BB_SW_OUT_0                    (R)
      6-7    BB_SW_OUT_1                    (R)
      8-9    BB_SW_OUT_2                    (R)
      10-13  BB_SW_COM_OUT                  (R)
      14-16  ANT_DIV_CFG_USED               (R)

ATH:029C3Ch/029F80h - BB_RSSI_B0 (R) ;hw4/hw6
ATH:02AF80h - BB_RSSI_B1 (R) ;hw6
ATH:02CF80h - BB_RSSI_B3 (R) ;hw6

      0-7    RSSI                           (R)
      8-15   RSSI_EXT                       (R)

ATH:029C40h/029F84h - BB_SPUR_EST_CCK_REPORT_B0 (R) ;hw4/hw6
ATH:02AF84h - BB_SPUR_EST_CCK_REPORT_B1 (R) ;hw6

      0-7    SPUR_EST_SD_I_CCK              (R)
      8-15   SPUR_EST_SD_Q_CCK              (R)
      16-23  SPUR_EST_I_CCK                 (R)
      24-31  SPUR_EST_Q_CCK                 (R)

ATH:029CF0h/029CACh/02A374h - BB_CHAN_INFO_NOISE_PWR ;hw4/hw4.2/hw6

      0-11   NOISE_POWER                    (R)

ATH:029CF4h/029CB0h/02A378h - BB_CHAN_INFO_GAIN_DIFF ;hw4/hw4.2/hw6

      0-11   FINE_PPM                       (R)
      12-18  hw6: ANALOG_GAIN_DIFF_01       (R)     ;-hw6

ATH:029CF8h/029CB4h/02A37Ch - BB_CHAN_INFO_FINE_TIMING ;hw4/hw4.2/hw6

      0-11   COARSE_PPM                     (R)
      12-21  FINE_TIMING                    (R)

ATH:029CFCh/029CB8h/02A380h - BB_CHAN_INFO_GAIN_B0 ;hw4/hw4.2/hw6
ATH:02B380h - BB_CHAN_INFO_GAIN_B1 ;hw6

      0-7    CHAN_INFO_RSSI                 (R)
      8-15   CHAN_INFO_RF_GAIN              (R)
      16     hw4: CHAN_INFO_XATTEN1_SW      (R)     ;\hw4 (and hw4.2)
      17     hw4: CHAN_INFO_XATTEN2_SW      (R)     ;/
      16-22  hw6: CHAN_INFO_MB_GAIN         (R)     ;\
      23     hw6: CHAN_INFO_XATTEN1_SW      (R)     ; hw6
      24     hw6: CHAN_INFO_XATTEN2_SW      (R)     ;/

ATH:029D00h.. - BB_CHAN_INFO_CHAN_TAB_B0[0..59] ;hw4
ATH:029CBCh.. - BB_CHAN_INFO_CHAN_TAB_B0[0..59] ;hw4.2
ATH:029B00h.. - BB_CHAN_INFO_CHAN_TAB_B0[0..59] ;hw6
ATH:02AB00h.. - BB_CHAN_INFO_CHAN_TAB_B1[0..59] ;hw6

      0-5    hw4: MAN_Q_0    ;\             (R)     ;\
      6-11   hw4: MAN_I_0    ; aka B0 ?     (R)     ;
      12-15  hw4: EXP_0      ;/             (R)     ; hw4 (and hw4.2)
      16-21  hw4: MAN_Q_1    ;\             (R)     ;
      22-27  hw4: MAN_I_1    ; aka B1 ?     (R)     ;
      28-31  hw4: EXP_1      ;/             (R)     ;/
      0-31   hw6: CHANINFO_WORD             (R)     ;-hw6

ATH:02A000h/029E3Ch - BB_PEAK_DET_CTRL_1 ;hw4/hw6

      0      USE_OC_GAIN_TABLE
      1      USE_PEAK_DET
      2-7    PEAK_DET_WIN_LEN
      8-12   PEAK_DET_TALLY_THR_LOW(_0)
      13-17  PEAK_DET_TALLY_THR_MED(_0)
      18-22  PEAK_DET_TALLY_THR_HIGH(_0)
      23-29  PEAK_DET_SETTLING
      30     PWD_PKDET_DURING_CAL
      31     PWD_PKDET_DURING_RX

ATH:02A004h/029E40h - BB_PEAK_DET_CTRL_2 ;hw4/hw6

      0-9    RFSAT_2_ADD_RFGAIN_DEL
      10-14  RF_GAIN_DROP_DB_LOW(_0)
      15-19  RF_GAIN_DROP_DB_MED(_0)
      20-24  RF_GAIN_DROP_DB_HIGH(_0)
      25-29  RF_GAIN_DROP_DB_NON(_0)
      30     hw6: ENABLE_RFSAT_RESTART

ATH:02A008h/029E44h - BB_RX_GAIN_BOUNDS_1 ;hw4/hw6

      0-7    RX_MAX_MB_GAIN
      8-15   RX_MAX_RF_GAIN_REF
      16-23  RX_MAX_RF_GAIN
      24     RX_OCGAIN_SEL_2G
      25     RX_OCGAIN_SEL_5G

ATH:02A00Ch/029E48h - BB_RX_GAIN_BOUNDS_2 ;hw4/hw6

      0-7    GC_RSSI_LOW_DB
      8-15   RF_GAIN_REF_BASE_ADDR
      16-23  RF_GAIN_BASE_ADDR
      24-31  RF_GAIN_DIV_BASE_ADDR

ATH:02A010h/029E4Ch - BB_PEAK_DET_CAL_CTRL ;hw4/hw6

      0-5    PKDET_CAL_WIN_THR
      6-11   PKDET_CAL_BIAS
      12-13  PKDET_CAL_MEAS_TIME_SEL

ATH:02A014h/029E50h - BB_AGC_DIG_DC_CTRL ;hw4/hw6

      0      USE_DIG_DC
      1-3    DIG_DC_SCALE_BIAS
      4-9    DIG_DC_CORRECT_CAP
      10     hw6: DIG_DC_SWITCH_CCK         ;-hw6
      16-31  DIG_DC_MIXER_SEL_MASK

ATH:02A018h/029F88h - BB_AGC_DIG_DC_STATUS_I_B0 (R) ;DIG_DC RES_I_0 ;hw4/hw6
ATH:02A01Ch/029F8Ch - BB_AGC_DIG_DC_STATUS_Q_B0 (R) ;DIG_DC RES_Q_0 ;hw4/hw6
ATH:02AF88h - BB_AGC_DIG_DC_STATUS_I_B1 (R) ;hw6
ATH:02AF8Ch - BB_AGC_DIG_DC_STATUS_Q_B1 (R) ;hw6

      0-8    DIG_DC_C1 RES_I_0 / RES_Q_0 / RES_I_1 / RES_Q_1    (R)
      9-17   DIG_DC_C2 RES_I_0 / RES_Q_0 / RES_I_1 / RES_Q_1    (R)
      18-26  DIG_DC_C3 RES_I_0 / RES_Q_0 / RES_I_1 / RES_Q_1    (R)

ATH:02A1F4h/02A398h - BB_BBB_TXFIR_0 ;TXFIR_COEFF_H0..H3 ;hw4/hw6
ATH:02A1F8h/02A39Ch - BB_BBB_TXFIR_1 ;TXFIR_COEFF_H4..H7 ;hw4/hw6
ATH:02A1FCh/02A3A0h - BB_BBB_TXFIR_2 ;TXFIR_COEFF_H8..H11 ;hw4/hw6

      0-7    TXFIR COEFF_H0 (4bit) / COEFF_H4 (6bit) / COEFF_H8 (8bit)
      8-15   TXFIR COEFF_H1 (4bit) / COEFF_H5 (6bit) / COEFF_H9 (8bit)
      16-23  TXFIR COEFF_H2 (5bit) / COEFF_H6 (7bit) / COEFF_H10 (8bit)
      24-31  TXFIR COEFF_H3 (5bit) / COEFF_H7 (7bit) / COEFF_H11 (8bit)

Note: The entries are aligned to 8bit boundaries, but not all entries are 8bit wide (eg. COEFF H0 and H1 are located in bit0-3 and bit8-11, with bit4-7 left unused).
ATH:02A200h/02A208h - BB_MODES_SELECT ;hw4/hw6

      0      CCK_MODE
      2      DYN_OFDM_CCK_MODE
      5      HALF_RATE_MODE
      6      QUARTER_RATE_MODE
      7      MAC_CLK_MODE
      8      DISABLE_DYN_CCK_DET
      9      hw6: SVD_HALF_RATE_MODE        ;\hw6
      10     hw6: DISABLE_DYN_FAST_ADC      ;/

ATH:02A204h/02A394h - BB_BBB_TX_CTRL ;hw4/hw6

      0      DISABLE_SCRAMBLER
      1      USE_SCRAMBLER_SEED
      2-3    TX_DAC_SCALE_CCK
      4      TXFIR_JAPAN_CCK
      5      ALLOW_1MBPS_SHORT
      6-8    TX_CCK_DELAY_1
      9-11   TX_CCK_DELAY_2

ATH:02A208h/029FC0h - BB_BBB_SIG_DETECT ;hw4/hw6

      0-5    WEAK_SIG_THR_CCK
      6-12   ANT_SWITCH_TIME
      13     ENABLE_ANT_FAST_DIV
      14     LB_ALPHA_128_CCK
      15     LB_RX_ENABLE_CCK
      16     CYC32_COARSE_DC_EST_CCK
      17     CYC64_COARSE_DC_EST_CCK
      18     ENABLE_COARSE_DC_CCK
      19     CYC256_FINE_DC_EST_CCK
      20     ENABLE_FINE_DC_CCK
      21     DELAY_START_SYNC_CCK
      22     USE_DC_EST_DURING_SRCH
      23     hw6: BBB_MRC_OFF_NO_SWAP               ;\hw6
      24     hw6: SWAP_DEFAULT_CHAIN_CCK            ;/
      31     ENABLE_BARKER_TWO_PHASE

ATH:02A20Ch/029E18h - BB_EXT_ATTEN_SWITCH_CTL_B0 ;hw4/hw6
ATH:02B20Ch/02AE18h - BB_EXT_ATTEN_SWITCH_CTL_B1 ;hw4/hw6

      0-5    XATTEN1_DB
      6-11   XATTEN2_DB
      12-16  XATTEN1_MARGIN
      17-21  XATTEN2_MARGIN
      22-26  hw6: XLNA_GAIN_DB                      ;-hw6

ATH:02A210h/029D00h - BB_BBB_RX_CTRL_1 ;hw4/hw6

      0-2    COARSE_TIM_THRESHOLD_2
      3-7    COARSE_TIM_THRESHOLD
      8-10   COARSE_TIM_N_SYNC
      11-15  MAX_BAL_LONG
      16-20  MAX_BAL_SHORT
      21-23  RECON_LMS_STEP
      24-30  SB_CHECK_WIN
      31     EN_RX_ABORT_CCK

ATH:02A214h/029D04h - BB_BBB_RX_CTRL_2 ;hw4/hw6

      0-5    FREQ_EST_N_AVG_LONG
      6-11   CHAN_AVG_LONG
      12-16  COARSE_TIM_THRESHOLD_3
      17-21  FREQ_TRACK_UPDATE_PERIOD
      22-25  FREQ_EST_SCALING_PERIOD
      26-31  LOOP_COEF_DPSK_C2_DATA

ATH:02A218h/029D08h - BB_BBB_RX_CTRL_3 ;hw4/hw6

      0-7    TIM_ADJUST_FREQ_DPSK
      8-15   TIM_ADJUST_FREQ_CCK
      16-23  TIMER_N_SFD

ATH:02A21Ch/029D0Ch - BB_BBB_RX_CTRL_4 ;hw4/hw6

      0-3    TIMER_N_SYNC
      4-15   TIM_ADJUST_TIMER_EXP
      16     FORCE_UNLOCKED_CLOCKS
      17     DYNAMIC_PREAM_SEL
      18     SHORT_PREAMBLE
      19-24  FREQ_EST_N_AVG_SHORT
      25-30  CHAN_AVG_SHORT
      31     hw6: USE_MRC_WEIGHT                    ;-hw6

ATH:02A220h/029D10h - BB_BBB_RX_CTRL_5 ;hw4/hw6

      0-4    LOOP_COEF_DPSK_C1_DATA
      5-9    LOOP_COEF_DPSK_C1_HEAD
      10-15  LOOP_COEF_DPSK_C2_HEAD
      16-20  LOOP_COEF_CCK_C1
      21-26  LOOP_COEF_CCK_C2

ATH:02A224h/029D14h - BB_BBB_RX_CTRL_6 ;hw4/hw6

      0-9    SYNC_START_DELAY
      10     MAP_1S_TO_2S
      11-20  START_IIR_DELAY
      21     hw6: USE_MCORR_WEIGHT                  ;\
      22     hw6: USE_BKPWR_FOR_CENTER_INDEX        ;
      23     hw6: CCK_SEL_CHAIN_BY_EO               ; hw6
      24     hw6: FORCE_CCK_SEL_CHAIN               ;
      25     hw6: FORCE_CENTER_INDEX                ;/

ATH:02A228h/029FC4h - BB_BBB_DAGC_CTRL ;hw4/hw6

      0      ENABLE_DAGC_CCK
      1-8    DAGC_TARGET_PWR_CCK
      9      ENABLE_BARKER_RSSI_THR
      10-16  BARKER_RSSI_THR
      17     ENABLE_FIRSTEP_SEL
      18-23  FIRSTEP_2
      24-27  FIRSTEP_COUNT_LGMAX
      28-29  hw6: FORCE_RX_CHAIN_CCK_0              ;\hw6
      30-31  hw6: FORCE_RX_CHAIN_CCK_1              ;/

ATH:02A22Ch/029D18h - BB_FORCE_CLKEN_CCK ;hw4/hw6

      0      FORCE_RX_ENABLE0
      1      FORCE_RX_ENABLE1
      2      FORCE_RX_ENABLE2
      3      FORCE_RX_ENABLE3
      4      FORCE_RX_ALWAYS
      5      FORCE_TXSM_CLKEN

ATH:02A230h/02A250h - BB_RX_CLEAR_DELAY ;hw4/hw6

      0-9    OFDM_XR_RX_CLEAR_DELAY

ATH:02A240h/029FCCh - BB_CCK_SPUR_MIT ;hw4/hw6

      0      USE_CCK_SPUR_MIT
      1-8    SPUR_RSSI_THR
      9-28   CCK_SPUR_FREQ
      29-30  SPUR_FILTER_TYPE

ATH:02A244h/02A7C0h - BB_PANIC_WATCHDOG_STATUS/BB_WATCHDOG_STATUS ;hw4/hw6

      0-2    (PANIC_)WATCHDOG_STATUS_1
      3      hw4: (PANIC_)WATCHDOG_DET_HANG         ;-hw4
      3      hw6: (PANIC_)WATCHDOG_TIMEOUT          ;-hw6
      4-7    (PANIC_)WATCHDOG_STATUS_2
      8-11   (PANIC_)WATCHDOG_STATUS_3
      12-15  (PANIC_)WATCHDOG_STATUS_4
      16-19  (PANIC_)WATCHDOG_STATUS_5
      20-23  (PANIC_)WATCHDOG_STATUS_6
      24-27  (PANIC_)WATCHDOG_STATUS_7
      28-31  (PANIC_)WATCHDOG_STATUS_8

ATH:02A248h/02A7C4h - BB_PANIC_WATCHDOG_CTRL_1/BB_WATCHDOG_CTRL_1 ;hw4/hw6

      0      ENABLE_(PANIC_)WATCHDOG_(TIMEOUT_RESET_)NON_IDLE
      1      ENABLE_(PANIC_)WATCHDOG_(TIMEOUT_RESET_)IDLE
      2-15   (PANIC_)WATCHDOG_(TIMEOUT_RESET_)NON_IDLE_LIMIT
      16-31  (PANIC_)WATCHDOG_(TIMEOUT_RESET_)IDLE_LIMIT

ATH:02A24Ch/02A7C8h - BB_PANIC_WATCHDOG_CTRL_2/BB_WATCHDOG_CTRL_2 ;hw4/hw6

      0      FORCE_FAST_ADC_CLK
      1      (PANIC_)WATCHDOG_(TIMEOUT_)RESET_ENA
      2      (PANIC_)WATCHDOG_IRQ_ENA

ATH:02A250h/029FC8h - BB_IQCORR_CTRL_CCK ;hw4/hw6

      0-4    IQCORR_Q_Q_COFF_CCK
      5-10   IQCORR_Q_I_COFF_CCK
      11     ENABLE_IQCORR_CCK
      12-13  RXCAL_MEAS_TIME_SEL
      14-15  CLCAL_MEAS_TIME_SEL
      16-20  CF_CLC_INIT_RFGAIN
      21     hw4.2: CF_CLC_PAL_MODE         ;-hw4.2 only (removed again in hw6)

ATH:02A254h/02A7CCh - BB_BLUETOOTH_CNTL ;hw4/hw6

      0      BT_BREAK_CCK_EN
      1      BT_ANT_HALT_WLAN
      2      hw6:ENABLE_RFBUS_GRANT_WAKEUP          ;-hw6

ATH:02A258h/02A3F8h - BB_TPC_1 ;hw4/hw6

      0      FORCE_DAC_GAIN
      1-5    FORCED_DAC_GAIN
      6-13   PD_DC_OFFSET_TARGET
      14-15  NUM_PD_GAIN
      16-17  PD_GAIN_SETTING1
      18-19  PD_GAIN_SETTING2
      20-21  PD_GAIN_SETTING3
      22     ENABLE_PD_CALIBRATE
      23-28  PD_CALIBRATE_WAIT
      29     FORCE_PDADC_GAIN
      30-31  FORCED_PDADC_GAIN

ATH:02A25Ch/02A3FCh - BB_TPC_2 ;hw4/hw6

      0-7    TX_FRAME_TO_PDADC_ON
      8-15   TX_FRAME_TO_PD_ACC_OFDM
      16-23  TX_FRAME_TO_PD_ACC_CCK

ATH:02A260h/02A400h - BB_TPC_3 ;hw4/hw6

      0-7    TX_END_TO_PDADC_ON
      8-15   TX_END_TO_PD_ACC_ON
      16-18  PD_ACC_WINDOW_DC_OFF
      19-21  PD_ACC_WINDOW_CAL
      22-24  PD_ACC_WINDOW_OFDM
      25-27  PD_ACC_WINDOW_CCK
      31     TPC_CLK_GATE_ENABLE

ATH:02A264h/02A404h - BB_TPC_4_B0 ;hw4/hw6
ATH:02B404h - BB_TPC_4_B1 ;hw6

      0      PD_AVG_VALID_0/1               (R)     ;\
      1-8    PD_AVG_OUT_0/1                 (R)     ;
      9-13   DAC_GAIN_0/1                   (R)     ; separate settings (on hw6)
      14-19  TX_GAIN_SETTING_0/1            (R)     ;
      20-24  RATE_SENT_0/1                  (R)     ;/
      25-30  ERROR_EST_UPDATE_POWER_THRESH          ;-global setting (not in B1)

ATH:02A268h/02A34Ch - BB_ANALOG_SWAP ;hw4/hw6

      0-2    ANALOG_RX_SWAP_CNTL
      3-5    ANALOG_TX_SWAP_CNTL
      6      SWAP_ALT_CHN
      7      ANALOG_DC_DAC_POLARITY
      8      ANALOG_PKDET_DAC_POLARITY

ATH:02A26Ch/02A408h - BB_TPC_5_B0 ;hw4/hw6
ATH:02B408h - BB_TPC_5_B1 ;hw6

      0-3    PD_GAIN_OVERLAP                        ;-global setting (not in B1)
      4-9    PD_GAIN_BOUNDARY_1_0/1                 ;\
      10-15  PD_GAIN_BOUNDARY_2_0/1                 ; separate settings (on hw6)
      16-21  PD_GAIN_BOUNDARY_3_0/1                 ;
      22-27  PD_GAIN_BOUNDARY_4_0/1                 ;/

ATH:02A270h/02A40Ch - BB_TPC_6_B0 ;hw4/hw6
ATH:02B40Ch - BB_TPC_6_B1 ;hw6

      0-5    PD_DAC_SETTING_1
      6-11   PD_DAC_SETTING_2
      12-17  PD_DAC_SETTING_3
      18-23  PD_DAC_SETTING_4
      24-25  ERROR_EST_MODE
      26-28  ERROR_EST_FILTER_COEFF

ATH:02A274h/02A410h - BB_TPC_7 ;hw4/hw6

      0-5    TX_GAIN_TABLE_MAX
      6-11   INIT_TX_GAIN_SETTING
      12     EN_CL_GAIN_MOD
      13     USE_TX_PD_IN_XPA
      14     EXTEND_TX_FRAME_FOR_TPC
      15     USE_INIT_TX_GAIN_SETTING_AFTER_WARM_RESET

ATH:02A280h..02A2FCh - BB_PDADC_TAB_B0[0..31] (W) ;hw4
ATH:02A480h..02A4FCh - BB_PDADC_TAB_B0[0..31] (W) ;hw6
ATH:02B480h..02B4FCh - BB_PDADC_TAB_B1[0..31] (W) ;hw6

      0-31   TAB_ENTRY                      (W)

ATH:02A300h..02A33Ch - BB_CL_TAB_B0[0..15] ;hw4
ATH:02A300h..02A33Ch - BB_CL_TAB_B0[0..15] ;hw6
ATH:02B300h..02B33Ch - BB_CL_TAB_B1[0..15] ;hw6 only (B1)

      0-4    CL_GAIN_MOD
      5-15   CARR_LK_DC_ADD_Q
      16-26  CARR_LK_DC_ADD_I
      27-30  BB_GAIN

ATH:02A340h/02A2DCh - BB_CL_MAP_0_B0 ;hw4/hw6
ATH:02A344h/02A2E0h - BB_CL_MAP_1_B0 ;hw4/hw6
ATH:02A348h/02A2E4h - BB_CL_MAP_2_B0 ;hw4/hw6
ATH:02A34Ch/02A2E8h - BB_CL_MAP_3_B0 ;hw4/hw6
ATH:02B2DCh - BB_CL_MAP_0_B1 ;hw6
ATH:02B2E0h - BB_CL_MAP_1_B1 ;hw6
ATH:02B2E4h - BB_CL_MAP_2_B1 ;hw6
ATH:02B2E8h - BB_CL_MAP_3_B1 ;hw6

      0-31   CL_MAP

ATH:02A358h/02A2D8h - BB_CL_CAL_CTRL ;hw4/hw6

      0      ENABLE_PARALLEL_CAL
      1      ENABLE_CL_CALIBRATE
      2-3    CF_CLC_TEST_POINT
      4-7    CF_CLC_FORCED_PAGAIN
      8-15   CARR_LEAK_MAX_OFFSET
      16-21  CF_CLC_INIT_BBGAIN
      22-29  CF_ADC_BOUND
      30     USE_DAC_CL_CORRECTION
      31     CL_MAP_HW_GEN

ATH:02A388h/02A244h - BB_RIFS ;hw4/hw6

      25     DISABLE_FCC_FIX
      26     ENABLE_RESET_TDOMAIN
      27     DISABLE_FCC_FIX2
      28     DISABLE_RIFS_CCK_FIX
      29     DISABLE_ERROR_RESET_FIX
      30     RADAR_USE_FDOMAIN_RESET

ATH:029934h/02A3C0h - BB_POWERTX_RATE1 ;Power TX_0..3 ;hw4/hw6
ATH:029938h/02A3C4h - BB_POWERTX_RATE2 ;Power TX_4..7 ;hw4/hw6
ATH:02A234h/02A3C8h - BB_POWERTX_RATE3 ;Power TX_1L,2L,2S ;hw4/hw6
ATH:02A238h/02A3CCh - BB_POWERTX_RATE4 ;Power TX_55L,55S,11L,11S ;hw4/hw6

      0-5    POWERTX_0 / POWERTX_4 / POWERTX_1L / POWERTX_55L
      8-13   POWERTX_1 / POWERTX_5 / -          / POWERTX_55S
      16-21  POWERTX_2 / POWERTX_6 / POWERTX_2L / POWERTX_11L
      24-29  POWERTX_3 / POWERTX_7 / POWERTX_2S / POWERTX_11S

ATH:02A38Ch/02A3D0h - BB_POWERTX_RATE5 ;Power TX HT20_0..3 ;hw4/hw6
ATH:02A390h/02A3D4h - BB_POWERTX_RATE6 ;Power TX HT20_4..7 ;hw4/hw6
ATH:02A3CCh/02A3E4h - BB_POWERTX_RATE10 ;Power TX HT20_8..11 ;hw4/hw6
ATH:02A3D0h/02A3E8h - BB_POWERTX_RATE11 ;Power TX HT20/40_12/13 ;hw4/hw6

      0-5    POWERTX HT20_0 / HT20_4 / HT20_8  / HT20_12
      8-13   POWERTX HT20_1 / HT20_5 / HT20_9  / HT20_13
      16-21  POWERTX HT20_2 / HT20_6 / HT20_10 / HT40_12
      24-29  POWERTX HT20_3 / HT20_7 / HT20_11 / HT40_13

ATH:02A3C0h/02A3D8h - BB_POWERTX_RATE7 ;Power TX HT40_0..3 ;hw4/hw6
ATH:02A3C4h/02A3DCh - BB_POWERTX_RATE8 ;Power TX HT40_4..7 ;hw4/hw6
ATH:02A3D4h/02A3ECh - BB_POWERTX_RATE12 ;Power TX HT40_8..11 ;hw4/hw6
ATH:02A3C8h/02A3E0h - BB_POWERTX_RATE9 ;PowerTX DUP40/EXT20_CCK/OFDM ;hw4/hw6

      0-5    POWERTX HT40_0 / HT40_4 / HT40_8  / DUP40_CCK
      8-13   POWERTX HT40_1 / HT40_5 / HT40_9  / DUP40_OFDM
      16-21  POWERTX HT40_2 / HT40_6 / HT40_10 / EXT20_CCK
      24-29  POWERTX HT40_3 / HT40_7 / HT40_11 / EXT20_OFDM

ATH:02A3BCh/02A3F4h - BB_POWERTX_SUB ;Power TX Sub_for_2chain ;hw4/hw6

      0-5    POWERTX SUB_FOR_2CHAIN

ATH:02A278h/02A414h - BB_TPC_8 ;DESIRED_SCALE_0..5 ;hw4/hw6

      0-4    DESIRED_SCALE_0
      5-9    DESIRED_SCALE_1
      10-14  DESIRED_SCALE_2
      15-19  DESIRED_SCALE_3
      20-24  DESIRED_SCALE_4
      25-29  DESIRED_SCALE_5

ATH:02A27Ch/02A418h - BB_TPC_9 ;DESIRED_SCALE_6,7,CCK and MISC ;hw4/hw6

      0-4    DESIRED_SCALE_6
      5-9    DESIRED_SCALE_7
      10-14  DESIRED_SCALE_CCK
      20     EN_PD_DC_OFFSET_THR
      21-26  PD_DC_OFFSET_THR
      27-30  WAIT_CALTX_SETTLE
      31     DISABLE_PDADC_RESIDUAL_DC_REMOVAL

ATH:02A394h/02A41Ch - BB_TPC_10 ;DESIRED_SCALE HT20_0..5 ;hw4/hw6
ATH:02A3E4h/02A42Ch - BB_TPC_14 ;DESIRED_SCALE HT20_8..13 ;hw4/hw6
ATH:02A3DCh/02A424h - BB_TPC_12 ;DESIRED_SCALE HT40_0..5 ;hw4/hw6
ATH:02A3E0h/02A428h - BB_TPC_13 ;DESIRED_SCALE HT40_6..7 ;hw4/hw6
ATH:02A3E8h/02A430h - BB_TPC_15 ;DESIRED_SCALE HT40_8..13 ;hw4/hw6

      0-4    DESIRED_SCALE HT20_0 / HT20_8  / HT40_0 / HT40_6 / HT40_8
      5-9    DESIRED_SCALE HT20_1 / HT20_9  / HT40_1 / HT40_7 / HT40_9
      10-14  DESIRED_SCALE HT20_2 / HT20_10 / HT40_2 / -      / HT40_10
      15-19  DESIRED_SCALE HT20_3 / HT20_11 / HT40_3 / -      / HT40_11
      20-24  DESIRED_SCALE HT20_4 / HT20_12 / HT40_4 / -      / HT40_12
      25-29  DESIRED_SCALE HT20_5 / HT20_13 / HT40_5 / -      / HT40_13

ATH:02A398h/02A420h - BB_TPC_11_B0 ;DESIRED_SCALE HT20_6..7 and OLPC ;hw4/hw6
ATH:02B420h - BB_TPC_11_B1 ;hw6

      0-4    DESIRED_SCALE HT20_6                   ;\global setting (not in B1)
      5-9    DESIRED_SCALE HT20_7                   ;/
      16-23  OLPC_GAIN_DELTA_0/1                    ;\
      24-31  hw4: OLPC_GAIN_DELTA_0/1_PAL_ON  ;-hw4 ; separate settings (on hw6)
      24-25  hw6: OLPC_GAIN_DELTA_0/1_LSB_EXT ;-hw6 ;/

ATH:02A39Ch/02A2C0h - BB_CAL_CHAIN_MASK ;hw4/hw6

      0-2    CAL_CHAIN_MASK

ATH:02A3D8h/02A358h - BB_FORCE_ANALOG ;hw4/hw6

      0      FORCE_XPAON
      1-3    FORCED_XPAON
      4      FORCE_PDADC_PWD
      5-7    FORCED_PDADC_PWD

ATH:02A3ECh/02A434h - BB_TPC_16 ;hw4/hw6

      8-13   PDADC_PAR_CORR_CCK
      16-21  PDADC_PAR_CORR_OFDM
      24-29  PDADC_PAR_CORR_HT40

ATH:02A3F0h/02A438h - BB_TPC_17 ;hw4/hw6

      0      ENABLE_PAL
      1      ENABLE_PAL_CCK
      2      ENABLE_PAL_OFDM_20
      3      ENABLE_PAL_OFDM_40
      4-9    PAL_POWER_THRESHOLD
      10     FORCE_PAL_LOCKED
      11-16  INIT_TX_GAIN_SETTING_PAL_ON

ATH:02A3F4h/02A43Ch - BB_TPC_18 ;hw4/hw6

      0-7    THERM_CAL_VALUE
      8-15   VOLT_CAL_VALUE
      16     USE_LEGACY_TPC
      17-22  hw6: MIN_POWER_THERM_VOLT_GAIN_CORR    ;-hw6

ATH:02A3F8h/02A440h - BB_TPC_19/BB_TPC_19_B0 ;hw4/hw6
ATH:02B440h - BB_TPC_19_B1 ;hw6

      0-7    ALPHA_THERM
      8-15   ALPHA_THERM_PAL_ON
      16-20  ALPHA_VOLT
      21-25  ALPHA_VOLT_PAL_ON

ATH:02A3FCh/02A444h - BB_TPC_20 ;hw4/hw6

      0-23   ENABLE_PAL_MCS_0..23

ATH:02A518h..02A554h - BB_CALTX_GAIN_SET_(0,2,4,6,..,28,30) ;hw4
ATH:02A600h..02A63Ch - BB_CALTX_GAIN_SET_(0,2,4,6,..,28,30) ;hw6
Contains 32 table entries (numbered 0..31), with two 14bit entries per word.

      0-13   CALTX_GAIN_SET_nn   table entry 0,2,4,6,...,28,30 accordingly
      14-27  CALTX_GAIN_SET_nn   table entry 1,3,5,7,...,29,31 accordingly
      28-31  -

ATH:02A400h..02A47Ch - BB_TX_GAIN_TAB_(1..32) ;hw4
ATH:02A500h..02A57Ch - BB_TX_GAIN_TAB_(1..32) ;hw6
Contains 32 table entries (numbered 1..32), with one 32bit entry per word.

      0-31   TG_TABLE entry   entry 1..32 accordingly

On hw6, the 32bit entries are expanded to 34bit size (with extra 2bits in the BB_TX_GAIN_TAB_xxx_LSB_EXT registers).
ATH:02A58Ch - BB_TX_GAIN_TAB_1_16_LSB_EXT ;hw6
ATH:02A590h - BB_TX_GAIN_TAB_17_32_LSB_EXT ;hw6
Contains 32 table entries (numbered 1..32), with sixteen 2bit entries per word.

      0-31   TG_TABLE_LSB_EXT  (sixteen 2bit entries per word)

These 2bit values are used to expand the 32bit entries in BB_TX_GAIN_TAB_(1..32) to 34bit size.
ATH:02A6DCh/02A644h - BB_TXIQCAL_CONTROL_0 ;hw4/hw6

      0      IQC_TX_TABLE_SEL
      1-6    BASE_TX_TONE_DB
      7-12   MAX_TX_TONE_GAIN
      13-18  MIN_TX_TONE_GAIN
      19-22  CALTXSHIFT_DELAY
      23-29  LOOPBACK_DELAY
      30     hw6: ENABLE_COMBINED_CARR_IQ_CAL       ;\hw6
      31     hw6: ENABLE_TXIQ_CALIBRATE             ;/

ATH:02A6E0h/02A648h - BB_TXIQCAL_CONTROL_1 ;hw4/hw6

      0-5    RX_INIT_GAIN_DB
      6-11   MAX_RX_GAIN_DB
      12-17  MIN_RX_GAIN_DB
      18-24  IQCORR_I_Q_COFF_DELPT

ATH:02A6E4h/02A64Ch - BB_TXIQCAL_CONTROL_2 ;hw4/hw6

      0-3    IQC_FORCED_PAGAIN
      4-8    IQCAL_MIN_TX_GAIN
      9-13   IQCAL_MAX_TX_GAIN

ATH:02A6E8h/0298B0h - BB_TXIQCAL_CONTROL_3 ;hw4/hw6

      0-5    PWR_HIGH_DB
      6-11   PWR_LOW_DB
      12-21  IQCAL_TONE_PHS_STEP
      22-23  DC_EST_LEN
      24     ADC_SAT_LEN
      25-26  ADC_SAT_SEL
      27-28  IQCAL_MEAS_LEN
      29-30  DESIRED_SIZE_DB
      31     TX_IQCORR_EN

ATH:02A6ECh/02A650h - BB_TXIQ_CORR_COEFF_01_B0 ;hw4/hw6
ATH:02A6F0h/02A654h - BB_TXIQ_CORR_COEFF_23_B0 ;hw4/hw6
ATH:02A6F4h/02A658h - BB_TXIQ_CORR_COEFF_45_B0 ;hw4/hw6
ATH:02A6F8h/02A65Ch - BB_TXIQ_CORR_COEFF_67_B0 ;hw4/hw6
ATH:02A6FCh/02A660h - BB_TXIQ_CORR_COEFF_89_B0 ;hw4/hw6
ATH:02A700h/02A664h - BB_TXIQ_CORR_COEFF_AB_B0 ;hw4/hw6
ATH:02A704h/02A668h - BB_TXIQ_CORR_COEFF_CD_B0 ;hw4/hw6
ATH:02A708h/02A66Ch - BB_TXIQ_CORR_COEFF_EF_B0 ;hw4/hw6
ATH:02B650h - BB_TXIQ_CORR_COEFF_01_B1 ;hw6
ATH:02B654h - BB_TXIQ_CORR_COEFF_23_B1 ;hw6
ATH:02B658h - BB_TXIQ_CORR_COEFF_45_B1 ;hw6
ATH:02B65Ch - BB_TXIQ_CORR_COEFF_67_B1 ;hw6
ATH:02B660h - BB_TXIQ_CORR_COEFF_89_B1 ;hw6
ATH:02B664h - BB_TXIQ_CORR_COEFF_AB_B1 ;hw6
ATH:02B668h - BB_TXIQ_CORR_COEFF_CD_B1 ;hw6
ATH:02B66Ch - BB_TXIQ_CORR_COEFF_EF_B1 ;hw6
The B0 (and B1) table each contain 16 entries (numbered 0..F), with two 14bit entries per word.

      0-13   IQC_COEFF_TABLE_n      ;table entry (n=0,2,4,6,8,A,C,E) accordingly
      14-27  IQC_COEFF_TABLE_n      ;table entry (n=1,3,5,7,9,B,D,F) accordingly
      28-31  -

ATH:02A70Ch/02A670h - BB_CAL_RXBB_GAIN_TBL_0 ;hw4/hw6
ATH:02A710h/02A674h - BB_CAL_RXBB_GAIN_TBL_4 ;hw4/hw6
ATH:02A714h/02A678h - BB_CAL_RXBB_GAIN_TBL_8 ;hw4/hw6
ATH:02A718h/02A67Ch - BB_CAL_RXBB_GAIN_TBL_12 ;hw4/hw6
ATH:02A71Ch/02A680h - BB_CAL_RXBB_GAIN_TBL_16 ;hw4/hw6
ATH:02A720h/02A684h - BB_CAL_RXBB_GAIN_TBL_20 ;hw4/hw6
ATH:02A724h/02A688h - BB_CAL_RXBB_GAIN_TBL_24 ;hw4/hw6
Contains 25 table entries (numbered 0..24), with four 6bit entries per word (except, only one entry in the last word).

      0-5    TXCAL_RX_BB_GAIN_TABLE_n   ;table entry (n=0,4, 8,12,16,20,24)
      6-11   TXCAL_RX_BB_GAIN_TABLE_n   ;table entry (n=1,5, 9,13,17,21)
      12-17  TXCAL_RX_BB_GAIN_TABLE_n   ;table entry (n=2,6,10,14,18,22)
      18-23  TXCAL_RX_BB_GAIN_TABLE_n   ;table entry (n=3,7,11,15,19,23)
      24-31  -

ATH:02A728h/02A68Ch - BB_TXIQCAL_STATUS_B0 (R) ;hw4/hw6
ATH:02B68Ch - BB_TXIQCAL_STATUS_B1 (R) ;hw6

      0      TXIQCAL_FAILED                 (R)
      1-5    CALIBRATED_GAINS               (R)
      6-11   TONE_GAIN_USED                 (R)
      12-17  RX_GAIN_USED                   (R)
      18-24  hw4: LAST_MEAS_ADDR (7bit)     (R)     ;-hw4
      18-23  hw6: LAST_MEAS_ADDR (6bit)     (R)     ;-hw6

ATH:02A7D8h/02A2CCh - BB_FCAL_1 ;hw4/hw6

      0-9    FLC_PB_FSTEP
      10-19  FLC_SB_FSTEP
      20-24  FLC_PB_ATTEN
      25-29  FLC_SB_ATTEN

ATH:02A7DCh/02A2D0h - BB_FCAL_2_B0 ;hw4/hw6
ATH:02B2D0h - BB_FCAL_2_B1 ;hw6

      0-2    FLC_PWR_THRESH                         ;-global setting (not in B1)
      3-7    FLC_SW_CAP_VAL_0/1                     ;-separate settings (on hw6)
      8-9    FLC_BBMISCGAIN                         ;\
      10-12  FLC_BB1DBGAIN                          ;
      13-14  FLC_BB6DBGAIN                          ; global setting (not in B1)
      15     FLC_SW_CAP_SET                         ;
      16-18  FLC_MEAS_WIN                           ;/
      20-24  FLC_CAP_VAL_STATUS_0/1         (R)     ;-separate settings (on hw6)

ATH:02A7E0h/02A22Ch - BB_RADAR_BW_FILTER ;hw4/hw6

      0      RADAR_AVG_BW_CHECK
      1      RADAR_DC_SRC_SEL
      2-3    RADAR_FIRPWR_SEL
      4-5    RADAR_PULSE_WIDTH_SEL
      8-14   RADAR_DC_FIRPWR_THRESH
      15-20  RADAR_DC_PWR_BIAS
      21-26  RADAR_BIN_MAX_BW

ATH:02A7E4h/02A2D4h - BB_DFT_TONE_CTRL_B0 ;hw4/hw6
ATH:02B2D4h - BB_DFT_TONE_CTRL_B1 ;hw6

      0      DFT_TONE_EN
      2-3    DFT_TONE_AMP_SEL
      4-12   DFT_TONE_FREQ_ANG

ATH:02A7E8h/02A448h - BB_THERM_ADC_1 ;hw4/hw6

      0-7    INIT_THERM_SETTING
      8-15   INIT_VOLT_SETTING
      16-23  INIT_ATB_SETTING
      24-25  SAMPLES_CNT_CODING
      26     USE_INIT_THERM_VOLT_ATB_AFTER_WARM_RESET
      27     FORCE_THERM_VOLT_ATB_TO_INIT_SETTINGS
      28     hw6: CHECK_DONE_FOR_1ST_ADC_MEAS_OF_EACH_FRAME   ;\hw6
      29     hw6: THERM_MEASURE_RESET                         ;/

ATH:02A7ECh/02A44Ch - BB_THERM_ADC_2 ;hw4/hw6

      0-11   MEASURE_THERM_FREQ
      12-21  MEASURE_VOLT_FREQ
      22-31  MEASURE_ATB_FREQ

ATH:02A7F0h/02A450h - BB_THERM_ADC_3 ;hw4/hw6

      0-7    THERM_ADC_OFFSET
      8-16   THERM_ADC_SCALED_GAIN
      17-29  ADC_INTERVAL

ATH:02A7F4h/02A454h - BB_THERM_ADC_4 ;hw4/hw6

      0-7    LATEST_THERM_VALUE             (R)
      8-15   LATEST_VOLT_VALUE              (R)
      16-23  LATEST_ATB_VALUE               (R)
      24     hw6: FORCE_THERM_CHAIN                           ;\hw6
      25-27  hw6: PREFERRED_THERM_CHAIN                       ;/

ATH:02A7F8h/02A458h - BB_TX_FORCED_GAIN ;hw4/hw6

      0      FORCE_TX_GAIN
      1-3    FORCED_TXBB1DBGAIN
      4-5    FORCED_TXBB6DBGAIN
      6-9    FORCED_TXMXRGAIN
      10-13  FORCED_PADRVGNA
      14-17  FORCED_PADRVGNB
      18-21  FORCED_PADRVGNC
      22-23  FORCED_PADRVGND
      24     FORCED_ENABLE_PAL
      25-27  hw6: FORCED_OB                         ;\
      28-30  hw6: FORCED_DB                         ; hw6
      31     hw6: FORCED_GREEN_PAPRD_ENABLE         ;/

ATH:02A7FCh/02A7DCh - BB_ECO_CTRL ;hw4/hw6

      0-7    ECO_CTRL

     ______________ below in hw4.2 and hw6 only (not original hw4) ______________

ATH:029DE4h/0298E4h - BB_PAPRD_AM2AM_MASK ;hw4.2/hw6 (not original hw4)

      0-24   PAPRD_AM2AM_MASK                       ;-newer revision only

ATH:029DE8h/0298E8h - BB_PAPRD_AM2PM_MASK ;hw4.2/hw6 (not original hw4)

      0-24   PAPRD_AM2PM_MASK                       ;-newer revision only

ATH:029DECh/0298ECh - BB_PAPRD_HT40_MASK ;hw4.2/hw6 (not original hw4)

      0-24   PAPRD_HT40_MASK                        ;-newer revision only

ATH:029DF0h - BB_PAPRD_CTRL0 ;hw4.2 (not original hw4)
ATH:0298F0h - BB_PAPRD_CTRL0_B0 ;hw6
ATH:02A8F0h - BB_PAPRD_CTRL0_B1 ;hw6

      0      PAPRD_ENABLE                           ;\
      1      PAPRD_ADAPTIVE_USE_SINGLE_TABLE        ; newer revision only
      2-26   PAPRD_VALID_GAIN                       ;
      27-31  PAPRD_MAG_THRSH                        ;/

ATH:029DF4h - BB_PAPRD_CTRL1 ;hw4.2 (not original hw4)
ATH:0298F4h - BB_PAPRD_CTRL1_B0 ;hw6
ATH:02A8F4h - BB_PAPRD_CTRL1_B1 ;hw6

      0      PAPRD_ADAPTIVE_SCALING_ENABLE          ;\
      1      PAPRD_ADAPTIVE_AM2AM_ENABLE            ;
      2      PAPRD_ADAPTIVE_AM2PM_ENABLE            ; newer revision only
      3-8    PAPRD_POWER_AT_AM2AM_CAL               ;
      9-16   PA_GAIN_SCALE_FACTOR                   ;
      17-26  PAPRD_MAG_SCALE_FACTOR                 ;
      27     PAPRD_TRAINER_IANDQ_SEL                ;/

ATH:029DF8h - BB_PA_GAIN123 ;hw4.2 (not original hw4)
ATH:0298F8h - BB_PA_GAIN123_B0 ;hw6
ATH:02A8F8h - BB_PA_GAIN123_B1 ;hw6

      0-9    PA_GAIN1                               ;\
      10-19  PA_GAIN2                               ; newer revision only
      20-29  PA_GAIN3                               ;/

ATH:029DFCh - BB_PA_GAIN45 ;hw4.2 (not original hw4)
ATH:0298FCh - BB_PA_GAIN45_B0 ;hw6
ATH:02A8FCh - BB_PA_GAIN45_B1 ;hw6

      0-9    PA_GAIN4                               ;\
      10-19  PA_GAIN5                               ; newer revision only
      20-24  PAPRD_ADAPTIVE_TABLE_VALID             ;/

ATH:029E00h..029E1Ch - BB_PAPRD_PRE_POST_SCALE_(0..7) ;hw4.2 (not hw4)
ATH:029900h..02991Ch - BB_PAPRD_PRE_POST_SCALE_(0..7)_B0 ;hw6
ATH:02A900h..02A91Ch - BB_PAPRD_PRE_POST_SCALE_(0..7)_B1 ;hw6

      0-17   PAPRD_PRE_POST_SCALING                 ;-newer revision only

ATH:029E20h.. - BB_PAPRD_MEM_TAB[......] ;hw4.2 (not original hw4)
ATH:029920h.. - BB_PAPRD_MEM_TAB_B0[0..119] ;hw6
ATH:02A920h.. - BB_PAPRD_MEM_TAB_B1[0..119] ;hw6

      0-21   PAPRD_MEM                              ;-newer revision only

ATH:02A35Ch/02A2ECh - BB_CL_MAP_PAL_0_B0 ;hw4.2/hw6 (not original hw4)
ATH:02A360h/02A2F0h - BB_CL_MAP_PAL_1_B0 ;hw4.2/hw6 (not original hw4)
ATH:02A364h/02A2F4h - BB_CL_MAP_PAL_2_B0 ;hw4.2/hw6 (not original hw4)
ATH:02A368h/02A2F8h - BB_CL_MAP_PAL_3_B0 ;hw4.2/hw6 (not original hw4)
ATH:02B2ECh - BB_CL_MAP_PAL_0_B1 ;hw6
ATH:02B2F0h - BB_CL_MAP_PAL_1_B1 ;hw6
ATH:02B2F4h - BB_CL_MAP_PAL_2_B1 ;hw6
ATH:02B2F8h - BB_CL_MAP_PAL_3_B1 ;hw6

      0-31   CL_MAP_PAL

ATH:02A72Ch/02A690h - BB_PAPRD_TRAINER_CNTL1 ;hw4.2/hw6 (not original hw4)

      0      CF_PAPRD_TRAIN_ENABLE                  ;\
      1-7    CF_PAPRD_AGC2_SETTLING                 ;
      8      CF_PAPRD_IQCORR_ENABLE                 ; newer revision only
      9      CF_PAPRD_RX_BB_GAIN_FORCE              ;
      10     CF_PAPRD_TX_GAIN_FORCE                 ;
      11     CF_PAPRD_LB_ENABLE                     ;
      12-18  CF_PAPRD_LB_SKIP                       ;/

ATH:02A730h/02A694h - BB_PAPRD_TRAINER_CNTL2 ;hw4.2/hw6 (not original hw4)

      0-31   CF_PAPRD_INIT_RX_BB_GAIN               ;-newer revision only

ATH:02A734h/02A698h - BB_PAPRD_TRAINER_CNTL3 ;hw4.2/hw6 (not original hw4)

      0-5    CF_PAPRD_ADC_DESIRED_SIZE              ;\
      6-11   CF_PAPRD_QUICK_DROP                    ;
      12-16  CF_PAPRD_MIN_LOOPBACK_DEL              ;
      17-19  CF_PAPRD_NUM_CORR_STAGES               ; newer revision only
      20-23  CF_PAPRD_COARSE_CORR_LEN               ;
      24-27  CF_PAPRD_FINE_CORR_LEN                 ;/
      28     hw4.2: CF_PAPRD_BBTXMIX_DISABLE        ;-hw4.2
      28     hw6: CF_PAPRD_REUSE_CORR               ;\hw6
      29     hw6: CF_PAPRD_BBTXMIX_DISABLE          ;/

ATH:02A738h/02A69Ch - BB_PAPRD_TRAINER_CNTL4 ;hw4.2/hw6 (not original hw4)

      0-11   CF_PAPRD_MIN_CORR                      ;\
      12-15  CF_PAPRD_SAFETY_DELTA                  ; newer revision only
      16-25  CF_PAPRD_NUM_TRAIN_SAMPLES             ;/

ATH:02A73Ch/02A6A0h - BB_PAPRD_TRAINER_STAT1 ;hw4.2/hw6 (not original hw4)

      0      PAPRD_TRAIN_DONE                       ;\
      1      PAPRD_TRAIN_INCOMPLETE         (R)     ;
      2      PAPRD_CORR_ERR                 (R)     ; newer revision only
      3      PAPRD_TRAIN_ACTIVE             (R)     ;
      4-8    PAPRD_RX_GAIN_IDX              (R)     ;
      9-16   PAPRD_AGC2_PWR                 (R)     ;/

ATH:02A740h/02A6A4h - BB_PAPRD_TRAINER_STAT2 ;hw4.2/hw6 (not original hw4)

      0-15   PAPRD_FINE_VAL                 (R)     ;\
      16-20  PAPRD_COARSE_IDX               (R)     ; newer revision only
      21-22  PAPRD_FINE_IDX                 (R)     ;/

ATH:02A744h/02A6A8h - BB_PAPRD_TRAINER_STAT3 ;hw4.2/hw6 (not original hw4)

      0-19   PAPRD_TRAIN_SAMPLES_CNT        (R)     ;-newer revision only

     ____________________________ below on hw4 only ____________________________

ATH:02A480h..02A4FCh - BB_TX_GAIN_TAB_PAL_(1..32) ;hw4 only (not hw6)
Contains 32 table entries (numbered 1..32), with one 32bit entry per word.

      0-31   TG_TABLE_PAL_ON   entry 1..32 accordingly

Seems to be some extra table, alternately to "BB_TX_GAIN_TAB_(1..32)". In hw6, this has been replaced by the "LSB_EXT" feature (see BB_TPC_11).
ATH:02A558h..02A6D4h - BB_TXIQCAL_MEAS_B0[0..95] (R) ;hw4 only (not hw6)

      0-11   TXIQC_MEAS_DATA0_0             (R)   ;entry 0,2,4,...,190 (?)
      12-23  TXIQC_MEAS_DATA1_0             (R)   ;entry 1,3,5,...,191 (?)
      24-31  -

ATH:02A6D8h - BB_TXIQCAL_START ;hw4 only (not hw6)

      0      DO_TX_IQCAL

     ____________________________ below on hw6 only ____________________________

ATH:029C04h - BB_LDPC_CNTL1 ;hw6

      0-31   LDPC_LLR_SCALING0

ATH:029C08h - BB_LDPC_CNTL2 ;hw6

      0-15   LDPC_LLR_SCALING1
      16-26  LDPC_LATENCY

ATH:029C18h - BB_ML_CNTL1 ;hw6

      0-23   CF_ML_2S_WEIGHT_TABLE
      24-25  CF_IS_FLAT_CH_THR_ML
      26-27  CF_IS_FLAT_CH_THR_ZF

ATH:029C1Ch - BB_ML_CNTL2 ;hw6

      0-23   CF_ML_3S_WEIGHT_TABLE

ATH:029E54h - BB_BT_COEX_1 ;hw6

      0-4    PEAK_DET_TALLY_THR_LOW_1
      5-9    PEAK_DET_TALLY_THR_MED_1
      10-14  PEAK_DET_TALLY_THR_HIGH_1
      15-19  RF_GAIN_DROP_DB_LOW_1
      20-24  RF_GAIN_DROP_DB_MED_1
      25-29  RF_GAIN_DROP_DB_HIGH_1
      30     BT_TX_DISABLE_NF_CAL

ATH:029E58h - BB_BT_COEX_2 ;hw6

      0-4    PEAK_DET_TALLY_THR_LOW_2
      5-9    PEAK_DET_TALLY_THR_MED_2
      10-14  PEAK_DET_TALLY_THR_HIGH_2
      15-19  RF_GAIN_DROP_DB_LOW_2
      20-24  RF_GAIN_DROP_DB_MED_2
      25-29  RF_GAIN_DROP_DB_HIGH_2
      30-31  RFSAT_RX_RX

ATH:029E5Ch - BB_BT_COEX_3 ;hw6

      0-1    RFSAT_BT_SRCH_SRCH
      2-3    RFSAT_BT_RX_SRCH
      4-5    RFSAT_BT_SRCH_RX
      6-7    RFSAT_WLAN_SRCH_SRCH
      8-9    RFSAT_WLAN_RX_SRCH
      10-11  RFSAT_WLAN_SRCH_RX
      12-13  RFSAT_EQ_SRCH_SRCH
      14-15  RFSAT_EQ_RX_SRCH
      16-17  RFSAT_EQ_SRCH_RX
      18-22  RF_GAIN_DROP_DB_NON_1
      23-27  RF_GAIN_DROP_DB_NON_2
      28-31  BT_RX_FIRPWR_INCR

ATH:029E60h - BB_BT_COEX_4 ;RFGAIN_EQV_LNA_0..3 ;hw6
ATH:029E64h - BB_BT_COEX_5 ;RFGAIN_EQV_LNA_4..7 ;hw6

      0-7    RFGAIN_EQV_LNA_0 / RFGAIN_EQV_LNA_4
      8-15   RFGAIN_EQV_LNA_1 / RFGAIN_EQV_LNA_5
      16-23  RFGAIN_EQV_LNA_2 / RFGAIN_EQV_LNA_6
      24-31  RFGAIN_EQV_LNA_3 / RFGAIN_EQV_LNA_7

ATH:029E68h - BB_REDPWR_CTRL_1 ;hw6

      0-1    REDPWR_MODE
      2      REDPWR_MODE_CLR
      3      REDPWR_MODE_SET
      4-8    GAIN_CORR_DB2
      9-12   SCFIR_ADJ_GAIN
      13-17  QUICKDROP_RF
      18     BYPASS_FIR_F
      19     ADC_HALF_REF_F

ATH:029E6Ch - BB_REDPWR_CTRL_2 ;hw6

      0-6    SC01_SW_INDEX
      7-13   SC10_SW_INDEX
      14-20  LAST_SC0_INDEX

ATH:029FD0h - BB_MRC_CCK_CTRL ;hw6

      0      BBB_MRC_EN
      1      AGCDP_CCK_MRC_MUX_REG
      2-4    AGCDP_CCK_PD_ACCU_THR_HI
      5-7    AGCDP_CCK_PD_ACCU_THR_LOW
      8-11   AGCDP_CCK_BARKER_RSSI_THR
      12-16  AGCDP_CCK_MRC_BK_THR_HI
      17-21  AGCDP_CCK_MRC_BK_THR_LOW
      22-27  AGCDP_CCK_MIN_VALUE

ATH:029FD4h - BB_CCK_BLOCKER_DET ;hw6

      0      CCK_FREQ_SHIFT_BLOCKER_DETECTION
      1      CCK_BLOCKER_DET_RESTART_WEAK_SIG
      2-5    CCK_BLOCKER_DET_BKSUM_NUM
      6-8    BK_VALID_DELAY
      9-13   CCK_BLOCKER_DET_THR
      14-19  CCK_BLOCKER_DET_DELAY_THR
      20-25  CCK_BLOCKER_MONITOR_TIME
      26     SKIP_RAMP_ENABLE
      27-31  CCK_DET_RAMP_THR

ATH:02A384h - BB_SM_HIST ;hw6

      0      SM_REC_EN
      1      SM_REC_MODE
      2-3    SM_REC_TIME_RES
      4-11   SM_REC_PART_EN
      12-14  SM_REC_CHN_EN
      15-18  SM_REC_DATA_NUM
      19     SM_REC_AGC_SEL
      20-22  SM_REC_MAC_TRIG
      24-29  SM_REC_LAST_ADDR               (R)

ATH:02A580h - BB_RTT_CTRL ;hw6

      0      ENA_RADIO_RETENTION
      1-6    RESTORE_MASK
      7      FORCE_RADIO_RESTORE

ATH:0298BCh - BB_GREEN_TX_CONTROL_1 ;hw6

      0      GREEN_TX_ENABLE
      1      GREEN_CASES

ATH:02D800h - BB_MIT_RF_CNTL ;hw6

      0      MIT_FORCE_SYNTH_ON
      1      MIT_FORCE_SYNTH_ON_EN
      2      MIT_FORCE_ACTIVE_ON

ATH:02D804h - BB_MIT_CCA_CNTL ;hw6

      0-2    MIT_CCA_MODE_SEL
      3-20   MIT_CCA_COUNT

ATH:02D808h - BB_MIT_RSSI_CNTL_1 ;hw6

      0-5    MIT_RSSI_TH
      6-11   MIT_RX_RF_ATT_TH_H
      12-17  MIT_RX_RF_ATT_TH_L
      18-23  MIT_RX_RF_ATT_OFFSET
      24-29  MIT_AGC_LIMIT

ATH:02D80Ch - BB_MIT_RSSI_CNTL_2 ;hw6

      0      MIT_AGC_SEL
      1-11   MIT_RSSI_BASE

ATH:02D810h - BB_MIT_TX_CNTL ;hw6

      0-7    MIT_TX_STA_CNT
      8-21   MIT_TX_END_DLY_CNT
      22     MIT_TX_THROUGH_ENA
      23-25  MIT_TXHDR_CHAIN_MASK_CCK
      26-28  MIT_TXHDR_PAPRD_TRAIN_MASK_CCK
      29-30  MIT_TXHDR_CHAN_MODE_CCK

ATH:02D814h - BB_MIT_RX_CNTL ;hw6

      0-7    MIT_RX_END_DLY_CNT
      8      MIT_RX_THROUGH_ENA

ATH:02D818h - BB_MIT_OUT_CNTL ;hw6

      0-1    MIT_CLK_TUNE_MOD
      2      MIT_NO_DATA_TO_ATH

ATH:02D81Ch - BB_MIT_SPARE_CNTL ;hw6

      0-30   MIT_SPARE_IN
      31     MIT_SPARE_OUT                  (R)

ATH:029F90h - BB_DC_CAL_STATUS_B0 (R) ;hw6
ATH:02AF90h - BB_DC_CAL_STATUS_B1 (R) ;hw6

      0-4    OFFSETC1I                      (R)
      5-9    OFFSETC1Q                      (R)
      10-14  OFFSETC2I                      (R)
      15-19  OFFSETC2Q                      (R)
      20-24  OFFSETC3I                      (R)
      25-29  OFFSETC3Q                      (R)

ATH:02A584h - BB_RTT_TABLE_SW_INTF_B0 ;hw6
ATH:02B584h - BB_RTT_TABLE_SW_INTF_B1 ;hw6

      0      SW_RTT_TABLE_ACCESS
      1      SW_RTT_TABLE_WRITE
      2-4    SW_RTT_TABLE_ADDR

ATH:02A588h - BB_RTT_TABLE_SW_INTF_1_B0 ;hw6
ATH:02B588h - BB_RTT_TABLE_SW_INTF_1_B1 ;hw6

      4-31   SW_RTT_TABLE_DATA

ATH:02A7F0h - BB_TABLES_INTF_ADDR_B0 ;hw6
ATH:02B7F0h - BB_TABLES_INTF_ADDR_B1 ;hw6
ATH:029BF0h - BB_CHN_TABLES_INTF_ADDR ;hw6
ATH:02ABF0h - BB_CHN1_TABLES_INTF_ADDR ;hw6

      2-17   TABLES_ADDR
      31     ADDR_AUTO_INCR

ATH:02A7F4h - BB_TABLES_INTF_DATA_B0 ;hw6
ATH:02B7F4h - BB_TABLES_INTF_DATA_B1 ;hw6
ATH:029BF4h - BB_CHN_TABLES_INTF_DATA ;hw6
ATH:02ABF4h - BB_CHN1_TABLES_INTF_DATA ;hw6

      0-31   TABLES_DATA

ATH:02CE00h - BB_DUMMY (R) ;hw6
ATH:02C800h - BB_DUMMY1[0..255] (R) ;hw6
ATH:02D200h - BB_DUMMY2[0..383] (R) ;hw6

      0      DUMMY                          (R)

Whatever "dummy" registers, maybe intended only for padding purposes; to get the three BB_RSSI_B0/B1/B3 registers mapped to 029F80h+(0,1,3)*1000h on hw6.

     _______________________ missing B1 registers in hw4 _______________________

hw4 does have only a few "B1" registers defined, although it does have a lot of "B0" registers - which would suggest the presence of corresponding "B1" registers, but those seem to exist only on hw6.
Maybe the hw4 designed was already aimed at adding "B1" registers in future.
Or maybe the "B1" registers DO EXIST even on hw4, being accessd by using something like "address of B0 register PLUS some offset", or by using the so-called "BASEBAND_2" and/or "BASEBAND_3" regions - and without mentioning that anywhere in hw4 source code?

DSi Atheros Wifi - Internal I/O - 0xxx00h - RDMA Registers (hw4/hw6)

These registers are same in hw4/hw6, except that:

     - base address changed from 30100h (hw4) to 54D00h (hw6)
     - number of regions has increased from 16 (hw4) to 32 (hw6)
     - accordingly, index for STATUS and INT_EN has has changed

ATH:030100h/054D00h - DMA_CONFIG ;hw4/hw6

      0      DMA_TYPE
      1      RTC_PRIORITY
      2      ENABLE_RETENTION
      3      WLMAC_PWD_EN
      4      WLBB_PWD_EN
      5-31   -

ATH:030104h/054D04h - DMA_CONTROL ;hw4/hw6

      0      STOP
      1      START
      2-31   -

ATH:030108h/054D08h - DMA_SRC ;hw4/hw6
ATH:03010Ch/054D0Ch - DMA_DEST ;hw4/hw6

      0-1    -
      2-31   ADDR

ATH:030110h/054D10h - DMA_LENGTH ;hw4/hw6

      0-11   WORDS
      12-31  -

ATH:030114h/054D14h - VMC_BASE ;hw4/hw6

      0-1    -
      2-31   ADDR

ATH:030118h/054D18h - INDIRECT_REG ;hw4/hw6

      0-1    -
      2-31   ID

ATH:03011Ch/054D1Ch - INDIRECT_RETURN ;hw4/hw6

      0-1    -
      2-31   ADDR

ATH:030120h..3015Ch - RDMA_REGION_(0..15)_ - located here in hw4, 16 regions
ATH:054D20h..54D9Ch - RDMA_REGION_(0..31)_ - located here in hw6, 32 regions

      0      NEXT
      1      INDI
      2-12   LENGTH
      13-31  ADDR

ATH:030160h/054DA0h - DMA_STATUS ;hw4/hw6
ATH:030164h/054DA4h - DMA_INT_EN ;hw4/hw6

      0      RUNNING       ;STATUS only (not INT_EN)
      1      STOPPED
      2      DONE
      3      ERROR
      4-14   ERROR_CODE    ;STATUS only (not INT_EN)
      15-31  -

DSi Atheros Wifi - Internal I/O - 03x000h - EFUSE Registers (hw4/hw6)

EFUSE exists in hw4/hw6, with some differences

     - base address changed from 31000h (hw4) to 30000h (hw6)
     - the single INTF region (hw4) replaced by two INTF regions (hw6)
     - four new registers added in hw6
     - indices for the two STROBE registers have changed

ATH:031000h/030000h - EFUSE_WR_ENABLE_REG ;hw4/hw6

      0      V
      1-31   -

ATH:031004h/030004h - EFUSE_INT_ENABLE_REG ;hw4/hw6
ATH:031008h/030008h - EFUSE_INT_STATUS_REG ;hw4/hw6

      0      V
      1-31   -

ATH:03100Ch/03000Ch - BITMASK_WR_REG ;hw4/hw6

      0-31   V

ATH:031010h/030010h - VDDQ_SETTLE_TIME_REG ;hw4/hw6

      0-31   V

ATH:031014h/030018h - RD_STROBE_PW_REG ;hw4/hw6

      0-31   V

ATH:031018h/03001Ch - PG_STROBE_PW_REG ;hw4/hw6

      0-31   V

ATH:031800h..031FFCh - EFUSE_INTF[0..511] - only one single area in hw4
ATH:030800h..030FFCh - EFUSE_INTF0[0..511] - first area in hw6 here
ATH:031000h..0317FCh - EFUSE_INTF1[0..511] - second area in hw6 here

      0-31   R

ATH:030014h - VDDQ_HOLD_TIME_REG ;hw6 only

      0-31   V

ATH:030020h - PGENB_SETUP_HOLD_TIME_REG ;hw6 only

      0-31   V

ATH:030024h - STROBE_PULSE_INTERVAL_REG ;hw6 only

      0-31   V

ATH:030028h - CSB_ADDR_LOAD_SETUP_HOLD_REG ;hw6 only

      0-31   V

DSi Atheros Wifi - Internal I/O - 034000h - More Stuff (hw6)

     __________________________________ STEREO __________________________________

ATH:034000h - STEREO0_CONFIG

      0-7    POSEDGE
      8      MASTER
      9      SAMPLE_CNT_CLEAR_TYPE
      10     MCK_SEL
      11     I2S_WORD_SIZE
      12-13  DATA_WORD_SIZE
      14-15  STEREO_MONO
      16     MIC_WORD_SIZE
      17     PCM_SWAP
      18     I2S_DELAY
      19     RESET
      20     MIC_RESET
      21     ENABLE
      22     REFCLK_SEL
      23     SPDIF_ENABLE

ATH:034004h - STEREO0_VOLUME

      0-4    CHANNEL0
      8-12   CHANNEL1

ATH:034008h - STEREO_MASTER_CLOCK

      0      MCK_SEL

ATH:03400Ch - STEREO0_TX_SAMPLE_CNT_LSB
ATH:034010h - STEREO0_TX_SAMPLE_CNT_MSB
ATH:034014h - STEREO0_RX_SAMPLE_CNT_LSB
ATH:034018h - STEREO0_RX_SAMPLE_CNT_MSB

      0-15   CH0
      16-31  CH1

     ________________________________ CHKSUM SEG ________________________________

ATH:035000h - CHKSUM_ACC_DMATX_CONTROL0
ATH:035004h - CHKSUM_ACC_DMATX_CONTROL1
ATH:035008h - CHKSUM_ACC_DMATX_CONTROL2
ATH:03500Ch - CHKSUM_ACC_DMATX_CONTROL3

      0      TXEN
      1      LITTLEENDIAN

ATH:035010h - CHKSUM_ACC_DMATX_DESC0
ATH:035014h - CHKSUM_ACC_DMATX_DESC1
ATH:035018h - CHKSUM_ACC_DMATX_DESC2
ATH:03501Ch - CHKSUM_ACC_DMATX_DESC3

      0-31   ADDR

ATH:035020h - CHKSUM_ACC_DMATX_DESC_STATUS

      0      UNDERRUN0
      1      UNDERRUN1
      2      UNDERRUN2
      3      UNDERRUN3
      4      BUSERROR
      5-8    DESC_INTR
      16-23  PKTCNT0
      24-25  CHAIN_NUM                      (R)

ATH:035024h - CHKSUM_ACC_DMATX_ARB_CFG

      0      RRMODE
      8-13   WGT0
      14-19  WGT1
      20-25  WGT2
      26-31  WGT3

ATH:035028h - CHKSUM_ACC_RR_PKTCNT01 ;PKT CNT0..1
ATH:03502Ch - CHKSUM_ACC_RR_PKTCNT23 ;PKT CNT2..3

      0-8    PKTCNT0 / PKTCNT2   ;9bit each
      16-24  PKTCNT1 / PKTCNT3

ATH:035030h - CHKSUM_ACC_TXST_PKTCNT

      0-7    N/A ?
      8-15   PKTCNT1             ;8bit each
      16-23  PKTCNT2
      24-31  PKTCNT3

ATH:035034h - CHKSUM_ACC_DMARX_CONTROL

      0      RXEN
      1      LITTLEENDIAN

ATH:035038h - CHKSUM_ACC_DMARX_DESC

      0-31   ADDR

ATH:03503Ch - CHKSUM_ACC_DMARX_DESC_STATUS

      0      OVERFLOW
      1      BUSERROR
      2      DESC_INTR
      16-23  PKTCNT

ATH:035040h - CHKSUM_ACC_INTR (R) ;ACC Interrupt (readonly)
ATH:035044h - CHKSUM_ACC_IMASK ;ACC Interrupt Mask

      0-3    RX_VAL
      4-16   TX_VAL

ATH:035048h - CHKSUM_ACC_ARB_BURST

      0-9    MAX_TX
      10     INCR16_EN
      11     INCR8_EN
      16-25  MAX_RX

ATH:035050h - CHKSUM_ACC_RESET_DMA

      0      TX
      1      RX

ATH:035054h - CHKSUM_CONFIG

      0      CHKSUM_SWAP
      4-9    TXFIFO_MAX_TH
      16-21  TXFIFO_MIN_TH
      22-31  SPARE

     ___________________________________ MMAC ___________________________________

ATH:038000h - RX_FRAME0
ATH:038008h - RX_FRAME1

      0      OWN
      1-12   LEN                            (R)
      13-14  SEQ_NUM                        (R)

ATH:038004h - RX_FRAME_0
ATH:03800Ch - RX_FRAME_1

      0-31   ADDR

ATH:038010h - MMAC_INTERRUPT_RAW
ATH:038014h - MMAC_INTERRUPT_EN

      0      RX_DONE0
      1      RX_CRC_FAIL0
      2      ACK_RESP_FAIL0
      3      RX_DONE1
      4      RX_CRC_FAIL1
      5      ACK_RESP_FAIL1
      6      RX_ERR_OVERFLOW
      7      TX_DONE
      8      TX_DONE_ACK_MISSING
      9      TX_DONE_ACK_RECEIVED
      10     TX_ERROR

ATH:038018h - RX_PARAM1

      0-31   VAP_ADDR_L

ATH:03801Ch - RX_PARAM0

      0-15   VAP_ADDR_U
      16-21  SIFS
      22-23  CAPTURE_MODE
      24-26  TYPE_FILTER
      27     LIVE_MODE

ATH:038020h - TX_COMMAND0

      0-11   LEN
      12     CRC
      13     EXP_ACK

ATH:038024h - TX_COMMAND

      0-31   ADDR

ATH:038028h - TX_PARAM

      0      ACK_MODE_EN
      1-6    ACK_TIMEOUT
      7-14   BACKOFF
      15     FORCE_ACKF_RSSI
      16-23  ACKF_RSSI

ATH:03802Ch - BEACON_PARAM

      0-15   INTERVAL
      16-27  LEN
      28     EN
      29     CRC
      30     RESET_TS

ATH:038030h - BEACON

      0-31   ADDR

ATH:038034h - TSF_L
ATH:038038h - TSF_U

      0-31   COUNT

     ___________________________________ FPGA ___________________________________

ATH:039000h - FPGA_REG1

      2      DCM_RELEASE
      4-7    EMUL_RADIO_CLOCK_RATIO
      8-9    LONG_SHIFT_CHAIN_OVERRIDE_INDEX
      10     ENABLE_LONG_SHIFT_CHAIN_OVERRIDE_INDEX
      11-15  LONG_SHIFT_DRIVE_PHASE
      16-20  LONG_SHIFT_SAMPLE_PHASE
      21-30  SPARE_FPGA_REG1
      31     FPGA_SRIF_DELAY

ATH:039004h - FPGA_REG2

      0-3    FPGA_PLATFORM_TYPE
      4-7    FPGA_IP_RELEASE_VERSION
      8-11   FPGA_IP_REVISION
      12     FPGA_OWL_PLL_ENABLED
      13     FPGA_LOOPBACK_I2C
      14-31  FPGA_SPARE

ATH:039008h - FPGA_REG4

      0      RADIO_0_TCK
      1      RADIO_0_TDI
      2      RADIO_0_TMS
      3      RADIO_0_TDO

     _______________________________ BRIDGE INTR _______________________________

ATH:040000h - INTERRUPT
ATH:040004h - INTERRUPT_MASK

      0-7    RX_(0..7)_COMPLETE
      8-15   RX_(0..7)_END
      16-23  TX_(0..7)_COMPLETE
      24-31  TX_(0..7)_END

     ___________________________________ MII ___________________________________

ATH:040100h - MII0_CNTL

      0-1    SELECT
      2      MASTER
      4-5    SPEED
      8-9    RGMII_DELAY

ATH:040104h - STAT_CNTL (whatever, MII related?)

      0      AUTOZ
      1      CLRCNT
      2      STEN
      3      GIG

     ___________________________________ MDIO ___________________________________

ATH:040200h - MDIO_REG[0..7]

      0-15   VALUE

ATH:040220h - MDIO_ISR

      0-7    REGS
      8-15   MASK

ATH:040224h - PHY_ADDR (whatever, MDIO related?)

      0-2    VAL

     _______________________________ BRIDGE RX/TX _______________________________

ATH:040800h - GMAC_RX_0_DESC_START_ADDRESS
ATH:040C00h - GMAC_TX_0_DESC_START_ADDRESS

      0-31   ADDRESS

ATH:040804h - GMAC_RX_0_DMA_START
ATH:040C04h - GMAC_TX_0_DMA_START

      0      START
      4      RESTART

ATH:040C08h - GMAC_TX_0_INTERRUPT_LIMIT

      0-3    COUNT
      4-15   TIMEOUT

ATH:040808h - GMAC_RX_0_BURST_SIZE
ATH:040C0Ch - GMAC_TX_0_BURST_SIZE

      0-1    BURST

ATH:04080Ch - GMAC_RX_0_PKT_OFFSET

      0-7    OFFSET

ATH:040810h - GMAC_RX_0_CHECKSUM

      0      TCP
      1      UDP

ATH:040814h - GMAC_RX_0_DBG_RX

      0-3    STATE

ATH:040C10h - GMAC_TX_0_DBG_TX

      16-31  FIFO_TOTAL_LEN
      0-2    STATE

ATH:040818h - GMAC_RX_0_DBG_RX_CUR_ADDR
ATH:040C14h - GMAC_TX_0_DBG_TX_CUR_ADDR

      0-31   ADDR

ATH:04081Ch - GMAC_RX_0_DATA_SWAP
ATH:040C18h - GMAC_TX_0_DATA_SWAP

      0      SWAP
      1      SWAPD

     _________________________________ USB CAST _________________________________

ATH:054000h - ENDP0

      0-7    MAXP
      16     STALL
      17     HSNAK
      20     DSTALL
      23     CHGSETUP

ATH:054008h - OUT1ENDP
ATH:054010h - OUT2ENDP
ATH:054018h - OUT3ENDP
ATH:054020h - OUT4ENDP
ATH:054028h - OUT5ENDP
ATH:05400Ch - IN1ENDP
ATH:054014h - IN2ENDP
ATH:05401Ch - IN3ENDP
ATH:054024h - IN4ENDP
ATH:05402Ch - IN5ENDP

      0-10   MAXP
      18-19  TYPE
      20-21  ISOD
      22     STALL
      23     VAL
      24     ISOERR
      28     HCSET          ;<-- for INxENDP registers only (not OUTxENDP)

ATH:05408Ch - USBMODESTATUS

      0      LS
      1      FS
      2      HS
      4      HOST
      5      DEVICE

ATH:054188h - EPIRQ ;Endpoint Interrupt Request
ATH:054194h - EPIEN ;Endpoint Interrupt Enable

      0-15   IN 0..15
      16-31  OUT 0..15

ATH:05418Ch - USBIRQ ;USB Interrupt Request
ATH:054198h - PIEN ;P Interrupt Enable

      0      SUDAV          IR
      1      SOF            IR
      2      SUTOK          IR
      3      SUSP           IR
      4      URES           IR
      5      HSPEED         IR
      6      OVERFLOW       IR
      7      LPM            IR
      16-31  OUTP           NGIRQ ?

ATH:0541A4h - FNCTRL

      0-2    MFR
      3-7    FRMNR0
      8-13   FRMNR1
      16-22  FNADDR
      24-31  CLKGATE

ATH:0541BCh - OTGREG

      0      OTGIRQ_IDLEIRQ
      1      OTGIRQ_SRPDETIRQ
      2      OTGIRQ_LOCSOFIRQ
      3      OTGIRQ_VBUSERRIRQ
      4      OTGIRQ_PERIPHIRQ
      8-11   OTGSTATE
      16     OTGCTRL_BUSREQ
      17     OTGCTRL_ABUSDROP
      18     OTGCTRL_ASETBHNPEN
      19     OTGCTRL_BHNPEN
      20     OTGCTRL_SRPVBUSDETEN
      21     OTGCTRL_SRPDATDETEN
      23     OTGCTRL_FORCEBCONN
      24     OTGSTATUS_BSE0SRP
      25     OTGSTATUS_CONN
      27     OTGSTATUS_ASESSVAL
      28     OTGSTATUS_BSESSEND
      29     OTGSTATUS_AVBUSVAL
      30     OTGSTATUS_ID

ATH:0541CCh - DMASTART
ATH:0541D0h - DMASTOP

      0-15   IN 0..15
      16..31 OUT 0..15

ATH:054400h - EP0DMAADDR ;what is Endpoint 0, normal are 1..5, not 0?
ATH:054420h - EP1DMAADDR
ATH:054440h - EP2DMAADDR
ATH:054460h - EP3DMAADDR
ATH:054480h - EP4DMAADDR
ATH:0544A0h - EP5DMAADDR

      2-31   ADDR

ATH:05442Ch - OUT1DMACTRL
ATH:05444Ch - OUT2DMACTRL
ATH:05446Ch - OUT3DMACTRL
ATH:05448Ch - OUT4DMACTRL
ATH:0544ACh - OUT5DMACTRL

      2-15   RINGSIZ
      16     ENDIAN
      17     DMASTOP
      18     DMASTART
      20     DMATUNLIM
      21     DMANINCR
      22     DMARING
      25     HLOCK
      26-27  HSIZE
      28-31  HRPROT

ATH:0D8000h - USB_IP_BASE

      ?

     ________________________________ I2C SLAVE ________________________________

ATH:054E00h - I2CFIFOCONTROL ;FIFO Control

      0      FIFO RESET
      1      FIFO PREFETCH
      2-4    FIFO READ LENGTH
      5-14   FIFO READ THRESHOLD
      15     FIFO READ STALL
      16-18  FIFO WRITE LENGTH
      19-28  FIFO WRITE THRESHOLD
      29     FIFO WRITE STALL

ATH:054E04h - I2CFIFOREADPTR ;FIFO Read WR+RD Pointers
ATH:054E10h - I2CFIFOWRITEPTR ;FIFO Write WR+RD Pointers

      0-9    WR PTR                         (R)
      16-25  RD PTR                         (R)

ATH:054E08h - I2CFIFOREADUPDATE ;FIFO Read Update
ATH:054E14h - I2CFIFOWRITEUPDATE ;FIFO Write Update

      0-10   UPDATE

ATH:054E0Ch - I2CFIFOREADBASEADDR ;FIFO Read Base Address
ATH:054E18h - I2CFIFOWRITEBASEADDR ;FIFO Write Base Address

      0-31   BASE

ATH:054E1Ch - I2CMEMCONTROL ;Mem Control

      0      RESET
      1      FLUSH

ATH:054E20h - I2CMEMBASEADDR ;Mem Base Address

      0-31   BASE

ATH:054E24h - I2CREGREADDATA ;Reg Read Data
ATH:054E28h - I2CREGWRITEDATA ;Reg Write Data (R) ;uh, write is read-only?

      0-31   DATA

ATH:054E2Ch - I2CREGCONTROL ;Reg Control

      0      RESET
      1      READ STALL
      2      WRITE STALL
      3-5    READ COUNT                (R)
      6-8    WRITE COUNT               (R)
      9      READ EMPTY                (R)
      10     WRITE FULL                (R)

ATH:054E30h - I2CCSRREADDATA ;Csr Read Data
ATH:054E34h - I2CCSRWRITEDATA ;Csr Write Data (R) ;uh, write is read-only?

      0-5    DATA (6bit, what is that?)

ATH:054E38h - I2CCSRCONTROL ;Csr Control

      0-7    READDELAY
      8      CLOCKREQUESTENABLE
      9-11   FILTERCLOCKSELECT
      12-14  FILTERCLOCKSCALE
      15-17  FILTERSDARXSELECT
      18-20  FILTERSCLRXSELECT

ATH:054E3Ch - I2CFILTERSIZE ;Filter Size

      0-7    SDA RX SIZE
      8-15   SCL RX SIZE

ATH:054E40h - I2CADDR ;Address

      0-6    FIFO ADDR
      8-14   MEM ADDR
      16-22  REG ADDR
      24-30  CSR ADDR

ATH:054E44h - I2CINT ;Interrupt Status
ATH:054E48h - I2CINTEN ;Interrupt Enable

      0      FIFO READ START INT            ;\
      1      FIFO READ FINISH INT           ;
      2      FIFO WRITE START INT           ;
      3      FIFO WRITE FINISH INT          ; R/W
      4      REG READ START INT             ;
      5      REG READ FINISH INT            ;
      6      REG WRITE START INT            ;
      7      REG WRITE FINISH INT           ;/
      8      FIFO READ EMPTY INT            ;\
      9      FIFO WRITE FULL INT            ; For Status: R
      10     FIFO READ THRESHOLD INT        ; For Enable: R/W
      11     FIFO WRITE THRESHOLD INT       ;/
      12     CSR INT                        ;-R/W

ATH:054E4Ch - I2CINTCSR ;Int Csr

      0      INT    ;Status            (R)
      1      INTEN  ;Enable

     _________________________________ MAP I2S _________________________________

ATH:055000h - MBOX_FIFO

      0-19   DATA

ATH:055004h - MBOX_FIFO_STATUS

      0      FULL
      2      EMPTY

ATH:055008h - MBOX_DMA_POLICY

      0      RX_ORDER
      1      RX_QUANTUM
      2      TX_ORDER
      3      TX_QUANTUM
      4-7    TX_FIFO_THRESH0

ATH:05500Ch - MBOX0_DMA_RX_DESCRIPTOR_BASE
ATH:055014h - MBOX0_DMA_TX_DESCRIPTOR_BASE

      2-27   ADDRESS

ATH:055010h - MBOX0_DMA_RX_CONTROL
ATH:055018h - MBOX0_DMA_TX_CONTROL

      0      STOP
      1      START
      2      RESUME

ATH:05501Ch - MBOX_FRAME

      0      RX_SOM
      2      RX_EOM

ATH:055020h - FIFO_TIMEOUT

      0-7    VALUE
      8      ENABLE

ATH:055024h - MBOX_INT_STATUS
ATH:055028h - MBOX_INT_ENABLE

      0      RX_NOT_FULL
      2      TX_NOT_EMPTY
      4      RX_UNDERFLOW
      5      TX_OVERFLOW
      6      TX_DMA_COMPLETE
      8      TX_DMA_EOM_COMPLETE
      10     RX_DMA_COMPLETE

ATH:05502Ch - MBOX_FIFO_RESET

      0      TX_INIT
      2      RX_INIT

ATH:055030h - MBOX_DEBUG_CHAIN0
ATH:055034h - MBOX_DEBUG_CHAIN1

      0-31   ADDRESS

ATH:055038h - MBOX_DEBUG_CHAIN0_SIGNALS
ATH:05503Ch - MBOX_DEBUG_CHAIN1_SIGNALS

      0-31   COLLECTION

     __________________________________ MAP RF __________________________________

ATH:xxx400h - INT_PENDING[0..11]

      0-31   REG (32bit x 12 entries)

ATH:xxx460h - INT_SRC (R)

      0-11   REG (12bit)    (R)

ATH:xxx430h - BB_WR_MASK_0
ATH:xxx434h - BB_WR_MASK_1
ATH:xxx438h - BB_WR_MASK_2
ATH:xxx43Ch - BB_WR_MASK_3
ATH:xxx448h - BB_RD_MASK_0
ATH:xxx44Ch - BB_RD_MASK_1
ATH:xxx450h - BB_RD_MASK_2
ATH:xxx454h - BB_RD_MASK_3

      0-10   REG (11bit)

ATH:xxx440h - RF_WR_MASK_0
ATH:xxx444h - RF_WR_MASK_1
ATH:xxx458h - RF_RD_MASK_0
ATH:xxx45Ch - RF_RD_MASK_1

      0-8    REG (9bit)

ATH:xxx000h - RAM1[0..255]

      0-7    DATA (8bit)
      8-31   -

ATH:xxx800h - RAM2[0..127]

      0-6    DATA (7bit)
      7-31   -

     ___________________________________ ODIN ___________________________________

ATH:xxx000h - PHY_CTRL0

      0-2    PLL_ICP
      3-5    PLL_RS
      6-14   PLL_DIV
      15-17  PLL_MOD
      18     PLL_OVERIDE
      19     TEST_SPEED_SELECT
      20     RX_PATTERN_EN
      21     TX_PATTERN_EN
      22     ANA_LOOPBACK_EN
      23     DIG_LOOPBACK_EN
      24-31  LOOPBACK_ERR_CNT   (R)

ATH:xxx004h - PHY_CTRL1

      0-1    RX_FILBW_SEL
      2      RX_FORCERXON
      3      RX_BYPASSEQ
      4      RX_LOWR_PDET
      5-6    RX_SELIR_100M
      7      RX_SELVREF0P6
      8      RX_SELVREF0P25
      9-11   RX_RSVD
      12     NO_PLL_PWD
      13     FORCE_SUSPEND
      18-19  TX_PATTERN_SEL
      20     USE_PLL_LOCKDETECT
      21-22  USE_PLL_LOCK_DLY_SEL
      23-25  CLKOBS_SEL
      26     ENABLE_REFCLK_GATE
      27     DISABLE_CLK_GATING
      31     PLL_OBS_MODE_N

ATH:xxx008h - PHY_CTRL2

      0      HSTXBIAS_PS_EN
      1      HSRXPHASE_PS_EN
      2-7    PWD_IPLL
      8-13   PWD_ISP
      20     TX_CAL_EN
      21     TX_CAL_SEL
      22-25  TX_MAN_CAL
      26     TX_LCKDET_OVR
      27-30  TX_RSVD
      31     PWD_EXTBIAS

ATH:xxx00Ch - PHY_CTRL3

      0-18   PWD_ITX
      21     TX_DISABLE_SHORT_DET
      22-24  TX_SELTEST
      25     TX_STARTCAL

ATH:xxx010h - PHY_CTRL4

      0-11   PWD_IRX

ATH:xxx014h - PHY_CTRL5

      0-6    TX_BIAS_DELAY
      7-12   EB_WATERMARK
      13     FORCE_IDDQ
      14     FORCE_TEST_J
      15     FORCE_TEST_K
      16     FORCE_TEST_SE0_NAK
      17     TEST_JK_OVERRIDE
      18-19  XCVR_SEL
      20     TERM_SEL
      21     SUSPEND_N
      22     DP_PULLDOWN
      23     DM_PULLDOWN
      24     HOST_DISCON_FIX_ON
      25     HOST_DISCON_DETECT_ON
      26-28  HOST_DISCON_SAMPLE_WIDTH

ATH:xxx018h - PHY_CTRL6

      0      AVALID
      1      BVALID
      2      VBUSVALID
      3      SESSEND
      4      IDDIG

ATH:xxx01Ch - PHY_STATUS (R)

      0-3    TX_CAL      (R)

DSi GPIO Registers

4004C00h DSi7 - GPIO Data In (R) (even in DS mode)

      0     GPIO18[0]   ;\maybe 1.8V signals? (1=normal)
      1     GPIO18[1]   ; (maybe these are the three "NC" pins on CPU,
      2     GPIO18[2]   ;/near to the other GPIO pins)
      3     Unused (0)
      4     GPIO33[0] Probably "GPIO330" test point on mainboard
      5     GPIO33[1] Headphone connect (HP#SP) (0=None, 1=Connected)
      6     GPIO33[2] Powerbutton interrupt (0=Short Keydown Pulse, 1=Normal)
      7     GPIO33[3] sound enable output (ie. not a useful input)

One of the above is probably the "IRQ_O" signal on mainboard (possibly the "power button" bit; if so, then that bit might be some general interrupt from the "BPTWL" chip, rather than being solely related to the power button).
Bit0-2 might be unused "NC" pins. Bit4 might be GPIO330, which might be just a test point without other connection. Bit7 might be connected to one of unknown vias (maybe that near GPIO330 test point?), and which might connect to somewhere (probably to TSC/sound as the bit seems to enable sound output - though, the cooking coach cart sets interrupt edge select bit7; which hints that the pin could be used for something; the interrupt isn't actually enabled though).
Some bits seem to be floating high-z (when switching from output/low to input they won't <instantly> get high).
4004C00h DSi7 - GPIO Data Out (W)

      0-2   GPIO18[0-2] Data Output (0=Low, 1=High)
      3     Unused (0)
      4-7   GPIO33[0-3] Data Output (0=Low, 1=High)

Used only when below is set to direction=out. Should be 80h (sound enable).
4004C01h DSi7 - GPIO Data Direction (R/W)

      0-2   GPIO18[0-2] Data Direction (0=Normal/Input, 1=Output)
      3     Unused (0)
      4-7   GPIO33[0-3] Data Direction (0=Normal/Input, 1=Output)

Should be usually set to 80h (bit0-6=Input, bit7=Output). When using output direction, the "Data In" register will return the "Data Out" value ANDed with external inputs.
Observe that HP#SP could be used as Output (output/low will probably cause the DSi to believe that there is no headphone connected, thus forcing the internal speakers to be enabled; possibly with/without disabling the headphones?).
4004C02h DSi7 - GPIO Interrupt Edge Select (R/W)

      0-2   GPIO18[0-2] Interrupt Edge Select (0=Falling, 1=Rising)
      3     Unused (0)
      4-7   GPIO33[0-3] Interrupt Edge Select (0=Falling, 1=Rising)

4004C03h DSi7 - GPIO Interrupt Enable (R/W)

      0-2   GPIO18[0-2] Interrupt Enable (0=Disable, 1=Enable)
      3     Unused (0)
      4-7   GPIO33[0-3] Interrupt Enable (0=Disable, 1=Enable)

4004C04h - DSi7 - GPIO_WIFI (R/W)

      0     Unknown (firmware keeps this bit unchanged when writing)
      1-7   Zero
      8     Wifi Mode (0=New Atheros/DSi-Wifi mode, 1=Old NDS-Wifi mode)
      9-15  Zero

Bit8 must be properly configured for DWM-W024 wifi boards (must be 1 for NDS-Wifi mode, and must be 0 for DSi-Wifi; else SDIO Function 1 commands won't work).
DWM-W015 boards seem to work fine regardless of that bit (unknown if the bit does have any (minor) effects on that boards at all).

DSi Console IDs

The DSi contains several unique per-console numbers:

      CPU/Console ID     - Found in Port 4004D00h, in AES Keys, and in Files
      eMMC CID Register  - Found in Main RAM, and in eMMC CID register
      Serial/Barcode     - Found in Main RAM, and on stickers, and in HWINFO_S.dat
      Wifi MAC Address   - Found in Main RAM, and in Wifi FLASH
      Nintendo WFC ID    - Found in Wifi FLASH

4004D00h - DSi7 - CPU/Console ID Code (64bit) (R)

      0-63  CPU/Console ID Code

This appears to be a PROM inside of the CPU TWL chip. The value is used to initialize KEY_X values for eMMC encryption/decryption. Common 64bit settings are:

      08201nnnnnnnn1nnh  for DSi (EUR) and DSi XL (USA)
      08202nnnnnnnn1nnh  for DSi XL
      08203nnnnnnnn1nnh  for DSi XL
      08204nnnnnnnn1nnh  for DSi
      08A15???????????h  for DSi
      08A18nnnnnnnn1nnh  for DSi (USA) (black)
      08A19nnnnnnnn1nnh  for DSi (USA)
      08A20nnnnnnnn1nnh  for DSi
      08A21nnnnnnnn1nnh  for DSi
      08A22???????????h  for DSi (USA)
      08A23???????????h  for DSi (EUR)
      08C267B7xxxxxxxxh  for 3DS
      6B27D20002000000h  for n3DS (unknown how that has happened)

The "n" digits appear to be always in BCD range (0..9), the other digits appear to be fixed (on known consoles).
The 64bit value is also stored as 16-byte ASCII string in "dev.kp". And, the ASCII string is also stored in footer of "Tad Files on SD Cards".
Port 4004D00h should be read only if the flag in 4004D08h is zero. Moreover, Port 4004D00h can be read only by firmware, and get's disabled for all known games, so most exploits will only see zeroes in 4004D00h..4004D08h.
Easiest way to obtain the 64bit value would be extracting it from SD Card (using modified "DSi SRL Extract" source code).
DSi SD/MMC DSiware Files on External SD Card (.bin aka Tad Files)
Obtaining the 64bit value by DSi software is working only indirectly:
With sudokuhax it can be simply "read" from 40044E0h (LSW) and 40044ECh (MSW). Whereas, that ports are write-only, so it needs some small efforts to "read" them.
With DSi cartridge exploits it's a bit more difficult: The values at 40044D4h..40044FBh are destroyed, but 40044D0h..40044D3h is left intact, which can be used to compute the original MSW value at 40044ECh, using a bunch of constants and maths operations (caution: the result may depend on carry-in from unknown LSBs, eg. the MSW may appear as 08A2nnnnh or 08E2nnnnh). Next, one can simply brute-force the LSW (there should be only 10 million combinations (assuming it to be a BCD number with one fixed digit), which could be scanned within less than 6 minutes using the DSi AES hardware).
Note: JimmyZ made some PC tools ("TWLbf" and "bfCL") that can bruteforce the Console ID or CID (or both) from encrypted eMMC images.
4004D08h - DSi7 - CPU/Console ID Flag (1bit) (R)

      0     CPU/Console ID Flag (0=Okay/Ready, 1=Bad/Busy)
      1-15  Unknown/Unused (0)

Some flag that indicates whether one can read the CPU/Console ID from Port 4004D00h. The flag should be usually zero (unknown when it could be nonzero, maybe shortly after power-up, or maybe when the internal PROM wasn't programmed yet; which should never happen in retail units).
eMMC CID Register
The CID can be read via SD/MMC commands, and it's also stored at 2FFD7BCh in RAM; the RAM value is little-endian 120bit (ie. without the CRC7 byte), zeropadded to 16-bytes (with 00h in MSB); the value looks as so;

      MY ss ss ss ss 03 4D 30 30 46 50 41 00 00 15 00  ;DSi Samsung KMAPF0000M-S998
      MY ss ss ss ss 32 57 37 31 36 35 4D 00 01 15 00  ;DSi Samsumg KLM5617EFW-B301
      MY ss ss ss ss 30 36 35 32 43 4D 4D 4E 01 FE 00  ;DSi ST NAND02GAH0LZC5 rev30
      MY ss ss ss ss 31 36 35 32 43 4D 4D 4E 01 FE 00  ;DSi ST NAND02GAH0LZC5 rev31
      MY ss ss ss ss 03 47 31 30 43 4D 4D 00 01 11 00  ;3DS whatever chiptype?
      MY ss ss ss ss 07 43 59 31 47 34 4D 00 01 15 00  ;3DS Samsung KLM4G1YE0C-B301

The value is used to initialize AES_IV register for eMMC encryption/decryption.
The "MY" byte contains month/year; with Y=0Bh..0Dh for 2008..2010 (Y=0Eh..0Fh would be 2011..2012, but there aren't any known DSi/3DS consoles using that values) (unknown how 2013 and up would be assigned; JEDEC didn't seem to mind to define them yet). The "ss" digits are a 32bit serial number (or actually it looks more like a 32bit random number, not like an incrementing serial value).
Without a working exploit (for reading RAM at 2FFD7BCh), the CID could be obtained by connecting wires to the eMMC chip. However, this might require whatever custom hardware/software setup (unknown if any standard tools like PC card readers are able to read the CID value).
Note: JimmyZ made some PC tools ("TWLbf" and "bfCL") that can bruteforce the Console ID or CID (or both) using hex values extracted from encrypted eMMC images.
To speedup CID bruting, one can extract the MY datecode from "Samsung YWW, KMAPF0000M-S998" text printed on the eMMC chip: the "YWW" is year/week, eg. 8xx means 2008, and translates to year "B" in the "MY" field.
For the ST chips, there seems to me a similar year/week (reading "KOR 99 YWW", but the year/week on ST chips is usually about a month older than the month/year in CID). Known ST date codes are AC/BC (Oct2009/Nov2009) for the "rev0" ones, and CC/1D (Dec2009/Jan2010) for the "rev1" ones (ie. the ST chips seem to have been mostly used in early DSi XL models).
Serial/Barcode
The barcode is found on a sticker on the bottom of console (and on an identical sticker underneath of the battery). It's also stored as ASCII string in HWINFO_S.dat file, and at 2FFFD71h in RAM.
The serial/barcode consists of 2-3 letters, followed by 8 digits, followed by a checksum digit.
The first letter indicates the console model:

      DSi             T  (or V for devunits)
      DSi XL/LL       W  (or unknown for devunits)
      3DS             C  (or E for devunits)
      3DS XL/LL       S  (or R for devunits)
      2DS             A  (or P for devunits)
      New 3DS         Y  (or Yxx00 for devunits)
      New 3DS XL/LL   Q  (or Qxx00 for devunits)
      New 2DS XL/LL   N  (or Nxx01 for devunits)

The next 1-2 letter(s) indicate the region:

      JPN Japan                             JF,JH,JM
      USA North America                     W
      USA Middle East, Southeast Asia       S
      EUR Europe                            EF,EH,EM
      AUS Australia (for 3DS: part of EUR)  AG,AH
      CHN China (iQue)                      CF,CH,CM
      KOR South Korea                       KF,KH,KM

The checksum can be calculated across 1st-8th digit (and ignoring the leading letters):

      9th = (250 - (1st+3rd+5th+7th) - 3*(2nd+4th+6th+8th)) mod 10

Unknown if the barcode is internally used for any purposes (such like encryption, or network identification).
dev.kp
This file contains another "TWxxxxxxxx" ID (with "xxxxxxxx" being a 32bit lowercase hex number), this 32bit Console ID is also used in .tik files (except in tickets for free system titles).
Wifi MAC Address - Found in Main RAM, Wifi FLASH, and Wifi EEPROM
The MAC is a unique 48bit number needed for Wifi communications. The MAC is stored in SPI bus Wifi FLASH, and it's also stored at 2FFFCF4h in RAM. The same MAC value is also stored in I2C bus Wifi EEPROM. The MAC can be also viewed in Firmware (see System Settings, Internet, Options, System Information). Common values for DSi are:

      00 22 4C xx xx xx    ;seen in DSi XL
      00 23 CC xx xx xx    ;seen in DSi
      00 24 1E xx xx xx    ;seen in DSi
      00 27 09 xx xx xx    ;seen in DSi

The value isn't used for eMMC encryption (the eMMC is still accessible when swapping the Wifi daughterboard). However, the MAC value is included in game ".bin" files stored on SD card (unknown if that is causing any issues when loading those games on a console with swapped Wifi daughterboard).
Nintendo WFC ID
This is some unknown purpose value stored in Wifi FLASH. The value can be viewed in Firmware (see System Settings, Internet, Options, System Information). The firmware does only show the lower 43bit of the value, in decimal format, multiplied by 1000, whilst the actual WFC in FLASH seems to be about 14 bytes (112bit). The firmware does also allow to "delete" and "transfer" the "WFC Configuration" (whatever that means).
Flipnote Studio ID
This ID consists of a 16-digit HEX number (can be viewed by clicking the "tool" symbol in upper right of Flipnote's main menu).
The first 8-digits have unknown meaning. The last 8-digits are same as the last 8-digits of the wifi MAC address.

DSi Unknown Registers

40021A0h ... second NDS cart slot, DSi prototype relict (?)

      ARM9: Can be set to 00000000h or 0000E043h
      ARM7: Can be set to 00000000h or 0000E043h

40021A4h ... second NDS cart slot, DSi prototype relict (?)

      ARM9: Can be set to 20000000h or FF7F7FFFh
      ARM7: Can be set to 00000000h or FF7F7FFFh

Can be all-zero on arm7, uh, or is that due to port being disabled somehow?

DSi Notes

DSi Detection
Cartridges are using the same executable for NDS and DSi mode, the executable must thus detect whether it is running on a NDS console or DSi console. At ARM9 this is usually done as follows:

      if ([4004000h] AND 03h)=01h then DSi_mode else NDS_mode

On ARM7 side, the executables are attempting to do the same thing, but they are (maybe accidently) skipping the detection depending on a 2nd I/O port:

      ;Caution: Below detection won't work with DSi exploits (because they are
      ;  usually having the ARM7 SCFG registers disabled - it would be thus better
      ;  to do the dection only on ARM9 side as described above, and then forward
      ;  the result to ARM7 side).
      if ([4004008h] AND 80000000h)=0 then skip_detection_and_assume_NDS_mode
      else if ([4004000h] AND 03h)=01h then DSi_mode else NDS_mode

In DSi_mode, the game can use additional hardware features, and it must be also aware of some changed BIOS SWI functions.
In NDS_mode, the game can use only old hardware features, in case of DSi-exclusive games: The cartridge must contain a small NDS function that displays a message saying that the game will work only on DSi consoles.
DSi Executables
The boot executables & entrypoints are always defined in the ARM9/ARM7 entries in cartridge header, regardless of whether the game is running on a NDS console or DSi console. The ARM9/ARM7 executables are thus restricted to max 2MByte size (for not violating the NDS memory limit). The ARM9i/ARM7i entries are allowing to load additional code or data, presumably to addresses (almost) anywhere within the DSi's 16MByte memory space. Of course, if you want to use separate executables for NDS and DSi mode, then you can put some small bootstrap loader into the ARM9/ARM7 area, which will then load the actual main executables.
DSi Official Games
There are only a few DSi-Exclusive games, and quite a lot of DSi-Enhanced games. The package of that games doesn't seem bear any DSi-logos, so it's hard to tell if a game contains DSi features (except via inofficial databases).
DSi Homebrew Games
These are extremly rare, hard to find, and practically non-existant yet. Most webpages are mis-offering NDS games as "homebrew DSi games" (which, well, they may work on DSi, but only in NDS mode).
There are a few "real" DSi homebrew games/emus/demos: Atari 5200 EMU, Atari 7800 EMU, CQuake, DSx86, GBA Emulator, Project Legends DS, Sandbox Engine, StellaDS, Zoomx3 - most or all of them seem to require weird DSi exploits (probably CycloDS iEvolution flashcarts), the games appear to be completely lacking DSi cartridge headers, without even setting the DSi flag in cartheader[012h].bit1 (and instead they do contain pre-historic NDS-passme headers for booting from GBA slot, which is definetely incompatible with real DSi consoles).

DSi Exploits

DSi executables require RSA signatures (signed with Nintendo's private key), which is making it impossible to run any unlicensed/homebrew code, except via exploits (eg. modified .sav data for tweaking licensed games into booting unlicensed code).
Unlaunch.dsi - first ever released DSi bootcode exploit
This exploit allows to get control of the DSi almost immediately after power-up with full SCFG_EXT access rights. That's making it the best possible exploit for any purpose.
It can be installed via any DSiware exploits (eg. Flipnote), or via hardmod.
Ready for use DSiware Exploits (crashing system titles from SD card)
There are two exploitable titles that can be exploited via simple SD card files (without needing hardmod or downgrading): DSi Camera and Flipnote
DSi Camera (aka Memory Pit exploit):
The DSI Camera is installed in all regions, and people can't install it, so this exploit should work for everyone. The original Memory Pit exploit (from shutterbug2000) worked only on unspecified firmwares, but there is newer Memory Pit (from zoogie) the works in all regions and firmware versions.
Usage: Replace the SD:\private\ds\app\484E494A\pit.bin file, then go to Camera SD Card Album.
Flipnote:
Flipnote exists for US+EUR+AUS+JAP regions (not CHN or KOR), and it has been available for free (either pre-installed, or free download from DSi shop), so many people should have that title (though, surprisingly, quite some people don't have it because they had never downloaded it for free when the DSi shop was still online; and some might have deleted it).
Anyways, if you have flipnote: Use the "Flipnote Lenny (or whatever it is called)" exploit, working for all four flipnote regions (US+EUR+AUS+JAP), the download URL seems to be this weird link:

      https://davejmurphy.com/%25CD%25A1-%25CD%259C%25CA%2596-%25CD%25A1/

downloading seems to require buying a newer PC, and a browser with strong https support and youtube playing capabilities for watching the installation guide (unless the download contains instructions in regular .txt format).
Other DSiware Exploits (DSi shop downloads crashed with .sav files)
Installing DSiware exploits requires downgrading the firmware (and in case of sudoku: also downgrading the game). Downgrading can be done by soldering a few wires to the eMMC chip and then using utilities like "TWLTool". Most recommended title would be Sudoku (it's cheapest and doesn't require any menu navigation; apart from getting through a "touch to start" screen).

      Region       Price Title
      US,EU/AU     $2    Sudoku (Electronic Arts)   (updated version in DSi shop)
      US,EU/AU     $5    Fieldrunners        (original version still in DSi shop)
      US,EU/AU     $5    Guitar Rock Tour ("grtpwn")      (no longer in DSi shop)
      US,EU/AU,JP  $8    Legends of Exidia   (original version still in DSi shop)
      US,...?      Free  Zelda 4 Swords                   (no longer in DSi shop)

Once when the game+exploit are installed, the exploits will boot a file called "boot.nds" from SD card (eg. rename dslink to that name for wifi boot).
The DSi shop closed in 2017, so one can no longer legally buy DSiware. One could install pirate copies with tweaked .tik files for exploitable games, but it would be pointless (doing so would require a hardmod, and if you have a hardmod, then you could as well install unlaunch directly).
Note: Originally, dsiwarehax were installed via SD card without soldering, but that works only when having downloaded the exploitable games prior to release of firmware 1.4.2.
As of 2017, the DSi shop is closing (one cannot add new DSi points to the shop account, but can still use old DSi points that are already on the account for a few months).
Note: Buying DSiware was quite expensive (ie. buying a $15 wii/dsi point card worked, but you couldn't resell or reuse the remaining dsi points on other consoles).
DSi Cartridge Exploits
Exploitable DSi cartridges have been mass-produced as gifts for fat, senile or unhealthy family members, and naturally most people will be glad to get rid of such games for less than $5 (including shipping).

      Biggest Loser (US,EU) (works with firmware 1.4.5) (=on all DSi's, as of 2015)
      Cooking Coach (US,EU) (blocked in firmware 1.4.4 and up)
      Classic Word Games (US,EU) (blocked in firmware 1.4.4 and up) (uncomfortable)

The cartridge contain rather small EEPROMs, barely enough to boot actual code via wifi. Wintermute's "dslink" utility is solving EEPROM size limits by storing extra boot code in the Wifi FLASH memory on DWM-W015 daughterboard (later DSi's with DWM-W024 daughterboards have small Wifi FLASH; workarounds would be to install a bigger FLASH chip in the daughterboard, or to try to squeeze the whole bootcode into the cartridge EEPROM). The different cartridges, and their localized titles are:
Biggest Loser (fitness game for fat people with dead animal food):

      TWL-VBLV-EUU  Biggest Loser USA (UK)  ;(European title has "USA" suffix)
      TWL-VBLE-USA  Biggest Loser (US)      ;(US title doesn't have "USA" suffix)

Cooking Coach (make healthy food with dead animals):

      TWL-VCKE-USA  My Healthy Cooking Coach (US)
      TWL-VCKV-UKV  My Cooking Coach - Prepare Healthy Recipes (UK)
      TWL-VCKS-SPA  Mi Experto en Cocina - Comida Saludable (ES)
      TWL-VCKF-FRA  Mon Coach Personnel - Mes Recettes Plaisir et Ligne (FR)
      TWL-VCKI-ITA  Il Mio Coach di Cucina - Prepara Cibi Sani e Gustosi (IT)
      TWL-VCKD-NOE  Mein Koch-Coach - Gesund und Lecker Kochen (DE)

Classic Word Games (crossword game) (more expensive, and less comfortable to use than Cooking Coach and Biggest Loser):

      TWL-VCWE-USA Classic Word Games (US)
      TWL-VCWV-UKV Classic Word Games (UK/EU)

The UK, ES, FR, IT, DE versions are working on all european consoles.
DSi Exploit Restrictions (for anything except Unlaunch exploit)
Initial memory content and register settings may be changed by the exploited game (and/or by the exploit's boot code), so the DSi won't be in the same state as when booting real licensed games.
Exploits are booted with some hardware features disabled:

      ARM7 cannot access to SCFG/MBK configuration and Console ID registers
      For DSiware Exploits: Cannot access DS Cartridge slot
      For Cartridge Exploits: Cannot access SD/MMC registers

Currently, the only known way to get control of that hardware features would be using scanlime's Main Memory Hack (ie. soldering about 50 wires to the DSi mainboard).
Whitelist exploit (unreleased)
Rocketlauncher was supposed to get full control over the DSi via buffer overflows during NDS cart whitelist checks (via invalid Offset+Length values in the "NDHI" section of the Whitelist file, matched to the currently inserted NDS cartridge).
Unfortunately, that exploit was never finished/released - and, as by now, Unlaunch.dsi can do the same thing (even earlier after power-up, working with all retail firmware versions/regions, and without needing a NDS cart to trigger the whitelist check).
DSi Flashcarts
The majority of DSi Flashcarts are "DSi compatible", which does barely mean that they can boot DS games on DSi consoles in DS mode (but cannot run DSi software in DSi mode). The only flashcart with "DSi mode" support is/was CycloDS iEvolution (based on Cooking Coach exploit, without support for newer firmwares).
Essentially, flashcarts aren't of too much use: Booting from built-in SD Card slot would also work without flashcarts, and Wifi boot would be more comfortable anyways.

DSi Regions

There are six DSi regions.
JP Region - 1 country, 1 language
Languages:

      Japanese (only japanese, there is no language option at all)

Contries:

      01h Japan (only japan, there is no country option at all)

Chinese Region (iQue)
Languages: Unknown (supposedly Chinese/Mandarin?, and maybe English or so)
Contries: Unknown (supposedly China only)

      A0h China?

China appears to refer to chinese mainland only (hongkong/taiwan are reportedly selling japanese consoles, and chinese mainland users may have imported consoles before iQue DSi launch - meaning that many chinese speaking users will be hardly able to play chinese DSi games; unless the games were released as "region-free" titles).
Korean Region - 1 country, 1 language
Languages:

      Koerean (only korean, there is no language option at all)

Contries:

      88h Korea (only korea, there is no country option at all)

Korea appears to refer to South Korea only (ie. there are no separate country/parental settings for North Korea).
Australia Region - 2 countries, 1 language (as of DSi Firmware Ver 1.4.5A)
Languages:

      English (only english, there is no language option at all)

Countries:

      41h Australia
      5Fh New Zealand

US Region - 47 countries, 3 languages (as of DSi Firmware Ver 1.3U)
Languages:

      English
      Francais (=French)
      Espanol  (=Spanish)

Countries:

      08h Anguilla
      09h Antigua and Barbuda
      0Ah Argentina
      0Bh Aruba
      0Dh Barbados
      0Eh Belize
      0Fh Bolivia
      10h Brazil
      11h British Virgin Islands
      12h Canada
      13h Cayman Islands
      14h Chile
      15h Colombia
      16h Costa Rica
      17h Dominica
      18h Dominican Republic
      19h Ecuador
      1Ah El Salvador
      1Bh French Guiana
      1Ch Grenada
      1Dh Guadeloupe
      1Eh Guatemala
      1Fh Guyana
      20h Haiti
      21h Honduras
      22h Jamaica
      23h Martinique
      24h Mexico
      25h Montserrat
      26h Netherlands Antilles
      27h Nicaragua
      28h Panama
      29h Paraguay
      2Ah Peru
      2Bh Saint Kitts and Nevis
      2Ch Saint Lucia
      2Dh Saint Vincent and the Grenadines
      99h Singapore
      2Eh Suriname
      0Ch The Bahamas
      2Fh Trinidad and Tobago
      30h Turks and Caicos Islands
      A8h United Arab Emirates
      31h United States
      32h Uruguay
      33h US Virgin Islands
      34h Venezuela

Europe Region - 47 countries, 5 languages (as of DSi Firmware Ver 1.4E)
Languages:

      English
      Francais (=French)
      Deutsch  (=German)
      Espanol  (=Spanish)
      Italiano (=Italian)

Countries:

      40h Albania
      42h Austria
      43h Belgium
      44h Bosnia and Herzegovnia
      45h Botswana
      46h Bulgaria
      47h Croatia
      48h Cyprus
      49h Czech Republic
      4Ah Denmark
      4Bh Estonia
      4Ch Finland
      4Dh France
      4Eh Germany
      4Fh Greece
      50h Hungary
      51h Iceland
      52h Ireland
      53h Italy
      54h Latvia
      55h Lesotho
      56h Liechtenstein
      57h Lithuania
      58h Luxembourg
      59h Macedonia
      5Ah Malta
      5Bh Montenegro
      5Ch Mozambique
      5Dh Namibia
      5Eh Netherlands
      60h Norway
      61h Poland
      62h Portugal
      63h Romania
      64h Russia
      65h Serbia
      66h Slovakia
      67h Slovenia
      68h South Africa
      69h Spain
      6Ah Swaziland
      6Bh Sweden
      6Ch Switzerland
      6Dh Turkey
      6Eh United Kindgom
      6Fh Zambia
      70h Zimbabwe

Note that Nintendo might expand those regions (for example, newer 'european' firmware versions might include additional african countries; unless those missing countries are already part of other/unknown regions).
The purpose of the "Country" option is unknown (maybe Nintendo has servers in different countries for online games). One known effect is that the Age Ratings in "Parental Controls" are localized per country (eg. "USK ab 18" for germany, or "18'TM" for france/finland).
The "Language" option affects the Firmware GUI, and the game title (from Icon/Title structure). Some games are also (trying to) adopt the Firmware's language setting for choosing the in-game language; but that can fail badly if the game doesn't support the selected language.
Additional Wii Regions (unsupported on DSi)

     Europe/Africa:
      71h 113: Azerbaijan
      72h 114: Mauritania (Islamic Republic of Mauritania)
      73h 115: Mali (Republic of Mali)
      74h 116: Niger (Republic of Niger)
      75h 117: Chad (Republic of Chad)
      76h 118: Sudan (Republic of the Sudan)
      77h 119: Eritrea (State of Eritrea)
      78h 120: Djibouti (Republic of Djibouti)
      79h 121: Somalia (Somali Republic)
     Southeast Asia:
      80h 128: Taiwan
      90h 144: Hong Kong
      91h 145: Macao
      98h 152: Indonesia
      9Ah 154: Thailand
      9Bh 155: Philippines
      9Ch 156: Malaysia
     Middle East:
      A9h 169: India
      AAh 170: Egypt
      ABh 171: Oman
      ACh 172: Qatar
      ADh 173: Kuwait
      AEh 174: Saudi Arabia
      AFh 175: Syria
      B0h 176: Bahrain
      B1h 177: Jordan

http://wiibrew.org/wiki/Country_Codes

3DS Reference

3DS Summary
3DS Memory and I/O Map
3DS Hardware Registers
3DS MISC Registers
3DS GPIO Registers
3DS Crypto Registers
3DS DMA Registers
3DS Config Registers
3DS SPI and I2C Bus
3DS Video
3DS Sound and Microphone
3DS Cartridge Registers
3DS Interrupts and Timers
ARM Vector Floating-point Unit (VFP)
3DS File Formats
3DS eMMC Partitions
3DS NCSD Format
3DS FIRM Format
3DS FIRM Encryption
3DS FIRM Versions
3DS FIRM Launch Parameters
3DS NCCH Format
3DS NCCH Extended Header
3DS NCCH ExeFS
3DS NCCH RomFS
3DS NCCH Encryption
3DS Files - Title Content Metadata (CMD)
3DS Files - Title Metadata (TMD)
3DS Files - Title Ticket (ticket.db)
3DS Files - Title Certificates (certs.db)
3DS Files - Title Database Files (title.db, import.db, etc.)
3DS Files - Title Installation Archive (CIA)
3DS Files - Title Homebrew Executables (3DSX)
3DS Files - Client Cert/Key (ClCertA)
3DS Files - CTCert
3DS Files - Dictionary (NJDC)
3DS Files - Guide (GBIN)
3DS Files - Version (CVer and NVer)
3DS Files - CRR0 and CRO0 Files
3DS Files - Archive DARC
3DS Files - Archive SARC
3DS Files - Archive arcless
3DS Files - Archive ZAR
3DS Files - CCAL Format (Hardware calibration, HWCAL)
3DS Files - Config Savegame
3DS Files - Title IDs
3DS Files - Title NS
3DS Files - Savedata Extdata
3DS Files - Savedata SAVE/BDRI/VSXE Formats
3DS Files - Savedata DISA and DIFF
3DS Files - Savedata DISA and DIFF - Data Pairs
3DS Files - Savedata DISA and DIFF - Checksums
3DS Files - Savedata Gamecard FLASH Encryption and Wear Leveling
3DS Files - Messages (MsgStdBn)
3DS Files - Video Icons (SMDH)
3DS Files - Video Banner (CBMD)
3DS Files - Video Banner (Extended Banner)
3DS Files - Video Layout (CLYT/FLYT)
3DS Files - Video Layout Animation (CLAN/FLAN)
3DS Files - Video Layout Images (CLIM/FLIM)
3DS Files - Video Archive (CGFX)
3DS Files - Video Shaders (DVLB and DVOB Format)
3DS Files - Video Fonts (CFNT and FFNT Format)
3DS Files - Video Texture Package (CTPK)
3DS Files - Video Bitmap (BMP)
3DS Files - Sound Archive (CSAR Format)
3DS Files - Sound SEQ (CSEQ Format)
3DS Files - Sound WSD (CWSD Format)
3DS Files - Sound Bank (CBNK Format)
3DS Files - Sound Wave Archive (CWAR Format)
3DS Files - Sound Wave Data (CWAV Format)
3DS Files - Sound Wave Streams (CSTM Format)
3DS Files - Sound Group (CGRP Format)
3DS Files - Sound IDs (CSID Format)
3DS Files - Sound DSP Binary (DSP1 aka .cdc)
3DS Files - BASE64 Encoding
3DS Files - Video 3D Photos (MPO)
3DS Files - Module NWM (Wifi Driver)
3DS Console IDs
Misc
3DS eMMC and MCU Images
3DS Component Lists
3DS Chipset Pinouts
Operating System
http://forums.nesdev.com/viewtopic.php?f=23&t=18490&p=242531#p242456
http://www.3dbrew.org/wiki/Services
http://www.3dbrew.org/wiki/Services_API
3DS Reverse Engineering
http://forums.nesdev.com/viewtopic.php?f=23&t=18490
Credits
http://www.3dbrew.org/wiki/IO_Registers

3DS Memory and I/O Map

ARM11 Memory Map

      Old3DS Address   Size          Description
      Yes   00000000h  10000h        ARM11 Bootrom mirror  ;also ITCM in ARM11 ?
      Yes   00010000h  10000h    64K ARM11 Bootrom
      Yes   10000000h  ?             IO "memory"
      Yes   17E00000h  2000h      8K MPCore private memory region (aka... IRQ ???)
      No    17E10000h  1000h      4K New3DS: L2C-310 Level 2 Cache Controller (2MB)
      Yes   18000000h  600000h  6M   VRAM (two 3Mbyte banks, VRAM_A and VRAM_B)
      No    1F000000h  400000h  4M   New3DS: extra memory (maybe VRAM and/or QTM?)
      Yes   1FF00000h  40000h   256K Teak DSP Code memory (aka Shared WRAM)
      Yes   1FF40000h  40000h   256K Teak DSP Data memory (aka Shared WRAM)
      Yes   1FF80000h  80000h   512K AXI WRAM
      Yes   20000000h  8000000h 128M FCRAM
      No    28000000h  8000000h 128M New3DS: FCRAM extension
      Yes   FFFF0000h  10000h        ARM11 Bootrom mirror

Note: ARM11 MMU supports virtual memory addresses (so above physical addresses may appear elsewhere in virtual memory).
ARM9 Memory Map

      Old3DS Address   Size          Description
      Yes   00000000h  "8000000h"    Instruction TCM, mirrored each 8000h bytes
      Yes   01FF8000h  8000h     32K Instruction TCM (used here by kernel & titles)
      Yes   07FF8000h  8000h         Instruction TCM (used here by bootrom)
      Yes   08000000h  100000h   1M  ARM9-only internal memory (and ARM7 regions)
      No    08100000h  80000h   512K New3DS:ARM9-only extension (if any/if enabled)
      Yes   10000000h  8000000h      IO "memory"
      Yes   18000000h  600000h   6M  VRAM (two 3Mbyte banks, VRAM_A and VRAM_B)
      Yes   1FF00000h  40000h   256K Teak DSP Code memory (aka Shared WRAM)
      Yes   1FF40000h  40000h   256K Teak DSP Data memory (aka Shared WRAM)
      Yes   1FF80000h  80000h   512K AXI WRAM
      Yes   20000000h  8000000h 128M FCRAM
      No    28000000h  8000000h 128M New3DS: FCRAM extension
      Yes   FFF00000h  4000h     16K Data TCM (mapped here during bootrom)
      Yes   FFFF0000h  10000h    64K ARM9 Bootrom

     __________________________________ I/O Maps __________________________________

ARM9-only Registers

      Physaddr   Old3DS  A9/A11  Category
      10000000h  Yes     A9      CONFIG9 Registers
      10001000h  Yes     A9      IRQ Registers
      10002000h  Yes     A9      NDMA Registers     DMA (alike DSi's NDMA)
      10003000h  Yes     A9      TIMER Registers    Timers (alike GBA/NDS/DSi)
      10004000h  Yes     A9      CTRCARD Registers  ROM cart in 3DS mode
      10005000h          A9      CTRCARD?           2nd ROM cart slot?
      10006000h  Yes     A9      SDMMC Registers    For eMMC and SD Card slot
      10007000h          A9      SDxx?              ?
      10008000h  Yes     A9      PXI Registers      aka IPC
      10009000h  Yes     A9      AES Registers      Crypto
      1000A000h  Yes     A9      SHA Registers      Crypto
      1000B000h  Yes     A9      RSA Registers      Crypto
      1000C000h  Yes     A9      XDMA Registers     DMA
      1000D000h  Yes     A9      SPI_CARD Registers Savedata in ROM carts
      10010000h  Yes     A9      CONFIG Registers   More CONFIG9 registers
      10011000h  Yes     A9      PRNG Registers     Pseudo Random Generator
      10012000h  Yes     A9      OTP Registers      Console IDs
      10018000h  Yes     A9      ARM7 Registers     GBA/NDS/DSi mode config

ARM11/ARM9 Registers
Below registers can be accessed by both ARM11 and ARM9. However, most of them are working best on ARM11 side (because IRQ and DMA startup modes are implemented on ARM11 side only; and, in some cases, even FIFOs are in a separate ARM11-only area at 10300000h and up).
One exception is NTRCARD (this does have IRQ/DMA on both ARM9 and ARM11 side).

      10100000h  Yes     A11/A9  Debug WIFI SDIO Regs?  ;uh, actually zerofilled
      10101000h  Yes     A11/A9  HASH Registers     Crypto (same as SHA)
      10102000h  Yes     A11/A9  Y2R_0 Registers    First YUV-to-RGBA
      10103000h  Yes     A11/A9  CSND Registers     Sound channels and capture
      10110000h  Yes     A11/A9  LGYFB_0            Legacy GBA/NDS Video
      10111000h  Yes     A11/A9  LGYFB_1            Legacy GBA/NDS Video
      10120000h  Yes     A11/A9  Camera Registers   Camera Bus 0 (DSi cameras)
      10121000h  Yes     A11/A9  Camera Registers   Camera Bus 1 (left-eye)
      10122000h  Yes     A11/A9  WIFI Registers     SDIO Wifi
      10123000h  Yes     A11/A9  ?                  SDIO?   ;uh, actually data.abt
      10130000h  No      A11/A9  L2B_0              New3DS: First RGB-to-RGBA
      10131000h  No      A11/A9  L2B_1              New3DS: Second RGB-to-RGBA
      10132000h  No      A11/A9  Y2R_1              New3DS: Second YUV-to-RGBA
      10140000h  Yes     A11/A9  CONFIG11 Registers
      10141000h  Yes     A11/A9  CONFIG11 Registers
      10142000h  Yes     A11/A9  SPI Registers      SPI Bus1 (Tsc)
      10143000h  Yes     A11/A9  SPI Registers      SPI Bus2 (unused)
      10144000h  Yes     A11/A9  I2C Registers      I2C Bus1 (for 3DS devices)
      10145000h  Yes     A11/A9  CODEC Registers    ?
      10146000h  Yes     A11/A9  HID Registers      Keypad
      10147000h  Yes     A11/A9  GPIO Registers
      10148000h  Yes     A11/A9  I2C Registers      I2C Bus2 (for 3DS gimmicks)
      10160000h  Yes     A11/A9  SPI Registers      SPI Bus0 (Pwrman,WifiFlash,Tsc)
      10161000h  Yes     A11/A9  I2C Registers      I2C Bus0 (for DSi devices)
      10162000h  Yes     A11/A9  MIC Registers      Microphone
      10163000h  Yes     A11/A9  PXI Registers      aka IPC
      10164000h  Yes     A9/A11  NTRCARD Registers  ROM Cart in NDS/DSi mode
      10165000h  Yes     A11/A9  MP Registers       NDS-Wifi WIFIWAITCNT(10165206h)
      10170000h  Yes     A11/A9  MP Registers       NDS-Wifi WS0 Area (8000h bytes)
      10178000h  Yes     A11/A9  MP Registers       NDS-Wifi WS1 Area (8000h bytes)
      10180000h                                     (end of above area)

ARM11-only Registers

      10200000h  Yes     A11     CDMA               DMA
      10201000h  Yes     A11     FCRAM Registers    FCRAM Control
      10202000h  Yes     A11     LCD Registers      LCD
      10203000h  Yes     A11     DSP Registers      Teak DSP (if enabled)
      10204000h  Yes     A11     UNKNOWN            ?
      10205000h  ?       -       N/A ?              ?
      10206000h  No      A11     CDMA               New3DS: DMA
      10207000h  No      A11     MVD Registers      New3DS: Movie Decoder or so?
      1020F000h  Yes     A11     AXI                ?
      10300000h  Yes     A11     FIFO? debug?  Maybe debug wifi FIFOs or so?
      10301000h  Yes     A11     FIFO HASH (SHA)          contains FIFO
      10302000h  Yes     A11     FIFO Y2R_0
      10310000h  Yes     A11     FIFO LGYFB_0
      10311000h  Yes     A11     FIFO LGYFB_1
      10320000h  Yes     A11     FIFO Camera Bus 0 (20h-word window FIFO)
      10321000h  Yes     A11     FIFO Camera Bus 1 (20h-word window FIFO)
      10322000h  Yes     A11     FIFO? wifi??  Maybe contains DATA32 FIFOs or so?
      10323000h  ?       ?       data abort (maybe SDIO FIFO for 10123000h, if any)
      10330000h  No      A11     FIFO L2B_0     New3DS: L2B_0 FIFO (empty=data_abt)
      10331000h  No      A11     FIFO L2B_1     New3DS: L2B_1 FIFO (empty=data_abt)
      10332000h  No      A11     FIFO MVD Y2R_1 New3DS: MVD Y2R FIFO
      10400000h  Yes     A11     GPU External Registers
      10401000h  Yes     A11     GPU Internal Registers
      17E00000h 100h     A11     MPCore SCU (Snoop Control Unit)
      17E00100h 100h     A11     MPCore CPU Interrupt Interface
      17E00200h 100h     A11     MPCore CPU0 Interrupt Interface ;\
      17E00300h 100h     A11     MPCore CPU1 Interrupt Interface ; (aliased for
      17E00400h 100h     A11     MPCore CPU2 Interrupt Interface ; debug purposes)
      17E00500h 100h     A11     MPCore CPU3 Interrupt Interface ;/
      17E00600h 100h     A11     MPCore CPU Timer and Watchdog
      17E00700h 100h     A11     MPCore CPU0 Timer and Watchdog  ;\
      17E00800h 100h     A11     MPCore CPU1 Timer and Watchdog  ; (aliased, too?)
      17E00900h 100h     A11     MPCore CPU2 Timer and Watchdog  ;  <-- N/A in 3DS?
      17E00A00h 100h     A11     MPCore CPU3 Timer and Watchdog  ;/ <-- N/A in 3DS?
      17E00B00h 500h     A11     MPCore Reserved (access causes a DECERR abort)
      17E01000h 1000h    A11     MPCore Global Interrupt Distributor
      17E10000h  No      A11     New3DS: L2C-310 Level 2 Cache Controller

IO registers starting at physical address 10200000h are not accessible from the ARM9 (which includes all LCD/GPU registers). It seems IO registers below physical address 10100000h are not accessible from the ARM11 bus (=trigger data abort, as so on all unused 1000h-byte areas).
ARM11 kernel virtual address mappings for these registers varies for different builds. For ARM11 user mode applications you have:

      physaddr = virtaddr-1EC00000h+10100000h

That is:

      Physical   Virtual
      101xxxxxh  1ECxxxxxh
      102xxxxxh  1EDxxxxxh

3DS MISC Registers

     _____________________________ UNKNOWN Registers  _____________________________

Unknown Registers at 10204000h (ARM11 only)

      10204000h 4    Unknown R/W=000000F1h (res=00000000h)
      10204004h 4    Unknown, readonly (00000001h) (R)
      10204008h 08h  Unused (0) ?
      10204010h 4    Unknown, readonly (00000202h) (R)
      10204014h 4    Unknown, readonly (12000802h) (R) (or data abort!)
      10204018h 08h  Unused (0) ?
      10204020h 4    Unknown, readonly (00000020h) (R) ;or res=00000000h?
      10204024h FDCh Unused (0) ?

     ______________________________ FCRAM Registers  ______________________________

FCRAM Control Registers (ARM11 only)

      10201000h 4    FCRAM_MODE (R/W)
      10201004h 0Ch  Unused (0)
      10201010h 4    FCRAM_DELAY (R/W)
      10201014h 0Ch  Unused (0)
      10201020h 4    FCRAM_OR_WHATEVER (R/W)
      10201024h FDCh Unused (0)

10201000h - FCRAM_MODE (R/W)

      0     FCRAM Mode (burst enable or so)  (0=GBA, 1=3DS/Fast)              (R/W)
      1-4   Unknown... (00h..0Fh, usually 0)                                  (R/W)
      5-31  Unused (0)

Bit0 must be cleared in GBA mode (where FCRAM is used to emulate the GBA cartridge ROM), when not clearing bit0, only about 1% of GBA ROM reads will correctly read from "addr", and the other 99% will accidentally read from "addr+20h" (wrapped within 800h-byte pages).
Changes to this register have no effect until applying them via CFG11_FCRAM_CNT.
10201010h - FCRAM_DELAY (R/W)

      0-1   Unknown...  (0..3, usually 0)                                     (R/W)
      2-15  Unused (0)
      16-18 FCRAM Delay (0..7 = Fast..Slow, usually 2)                        (R/W)
      19-31 Unused (0)

Changes to this register have no effect until applying them via CFG11_FCRAM_CNT.
10201020h - FCRAM_OR_WHATEVER (R/W)

      0-3   Unknown... (00h..0Fh, usually 8)                                  (R/W)
      4-7   Unused (0)
      8-11  Unknown... (00h..0Fh, usually 8)                                  (R/W)
      12-30 Unused (0)
      31    Unknown... (0..1, usually 0)                                      (R/W)

Changes to this register have no effect until applying them via CFG11_FCRAM_CNT (probably so... assuming that it works similar as the registers above, and that changes do have some yet unknown effect at all).
Internal FCRAM Configuration Registers
The 3DS uses the following FCRAM chips:

      Old3DS: Fujitsu MB82M8080-07L (128Mbyte)
      New3DS: Fujitsu 82MK9A9A, 7L (256Mbyte)

The chip in Old3DS does reportedly internally contain 2 dies:

      MB81EDS516545 (4x2Mx64bit, aka 64Mbyte)
      MB82DBS08645 (unknown, supposedly contains the missing 64Mbyte)

The MB81EDS516545 datasheet says that there are some internal config registers, which must be initialized after power up, the initialization requires changing /RAS and /CAS and some other pins. Unknown if/how the 3DS hardware or software can/may/must initialize those registers.

     ______________________________ SD/MMC Registers ______________________________

SD/MMC Registers

      10006000h A9      SD/MMC (for SD/MMC Slot and internal eMMC)
      10006200h A9      mirrors of above (each 200h bytes)
      10007000h A9      SDxx (unused? or maybe SDIO wifi on ARM9 side?)
      10007200h A9      mirrors of above (each 200h bytes)
      10100000h A11/A9  Debug SDIO Regs? (actually just zerofilled?)
      10122000h A11/A9  SDIO WIFI? this is wifi?
      10123000h A11/A9  Reportedly SDIO? (actually just data abort?)

These registers are used to access the system NAND and the inserted SD card. Both devices use the same interface.
HCLK of the SDMMC controller is 67.027964 MHz (double of the DSi HCLK).
Unknown if eMMC and Wifi are fast enough to support HCLK/2 on 3DS.
Standard SD cards may require HCLK/4 on 3DS (unless the card was detected to support HCLK/2; don't know if it requires further card initialization to enable fast mode?).
DSi SD/MMC Protocol and I/O Ports
DSi SD/MMC Filesystem
DSi Atheros Wifi SDIO Interface
DSi Atheros Wifi Internal Hardware
IRQ_STAT

      3     SD card removal flag     (Set to 1 when SD card is removed)
      4     SD card insertion flag   (Set to 1 when SD card is inserted)
      5     SD card insertion status (0=Missing, 1=Inserted)

SD card insertion status
Assertion happens around 250 ms after SD card insertion and/or enabling the EMMC hardware (delay could possibly be due to an SD bus timeout?).
Wifi Registers
These registers are used to control the Wifi card via the SDIO protocol.

      Address  Width  Name
      10122000h 2  WIFI_CMD
      10006002h 2  uh, at 10006002h?
      10122004h 2  WIFI_CMDARG0
      10122006h 2  WIFI_CMDARG1
      1012200ah 2  WIFI_BLKCOUNT
      10122024h 2  WIFI_CLKCTL
      10122026h 2  WIFI_BLKLEN

XXX DATA32 FIFO might be at 10322000h (instead of 1012210Ch)... ?

     _______________________________ IPC Registers ________________________________

PXI Registers

      Address Width Old3DS Name         Used by
      10008000h 4   Yes   PXI_SYNC9     Boot9, Process9     ;-SYNC
      10008004h 2   Yes   PXI_CNT9      Boot9, Process9     ;\
      10008008h 4   Yes   PXI_SEND9                         ; FIFO
      1000800Ch 4   Yes   PXI_RECV9                         ;/
      10163000h 4   Yes   PXI_SYNC11    Boot11              ;-SYNC
      10163004h 2   Yes   PXI_CNT11     Boot11              ;\
      10163008h 4   Yes   PXI_SEND11                        ; FIFO
      1016300Ch 4   Yes   PXI_RECV11                        ;/

The PXI registers are similar to those on DS. Uh, aka what is known as IPC.
But, except, SYNC is 8bit (instead 4bit)!
The FIFO registers seem to be exactly same as on NDS.
10008000h - ARM9 - PXI_SYNC9
10163000h - ARM11 - PXI_SYNC11

      0-7   R    Data received from remote SYNC bit8-15
      8-15  W    Data sent to remote SYNC bit0-7 (CAUTION: write-only, unlike NDS!)
      16-22 -    Unused (0)
      23    -    Unused (0)   ;<-- reportedly "?" whatever that means, if anything?
      24-28 -    Unused (0)
      29    -    PXI_SYNC11: Unused (0)
      30    W    PXI_SYNC11: Send IRQ to ARM9 IF.bit12 (0=No change, 1=Yes)
      29    W    PXI_SYNC9: Send IRQ to ARM11 IRQ 50h  (0=No change, 1=Yes)
      30    W    PXI_SYNC9: Send IRQ to ARM11 IRQ 51h  (0=No change, 1=Yes)
      31    R/W  Enable IRQ from remote CPU            (0=Disable, 1=Enable)

Caution: The send-value (in bit8-15) is write-only on 3DS (reads as zero), this is different as on NDS/DSi. As workaround: Use 8bit LDRB/STRB instead of 32bit LDR/STR when changing the IRQ bits.
10008004h - ARM9 - PXI_CNT
10163004h - ARM11 - PXI_CNT

      0     R    Send Fifo Empty Status      (0=Not Empty, 1=Empty)
      1     R    Send Fifo Full Status       (0=Not Full, 1=Full)
      2     R/W  Send Fifo Empty IRQ         (0=Disable, 1=Enable)
      3     W    Send Fifo Clear             (0=Nothing, 1=Flush Send Fifo)
      4-7        unknown/unspecified
      8     R    Receive Fifo Empty          (0=Not Empty, 1=Empty)
      9     R    Receive Fifo Full           (0=Not Full, 1=Full)
      10    R/W  Receive Fifo Not Empty IRQ  (0=Disable, 1=Enable)
      11-13      unknown/unspecified
      14    R/W  Error, Read Empty/Send Full (0=No Error, 1=Error/Acknowledge)
      15    R/W  Enable Send/Receive Fifo    (0=Disable, 1=Enable)

10008008h - ARM9 - PXI_SEND
10163008h - ARM11 - PXI_SEND
1000800Ch - ARM9 - PXI_RECV
1016300Ch - ARM11 - PXI_RECV
FIFO
DS Inter Process Communication (IPC)
ARM11-to-ARM11 Messages
ARM11 cores can use the Software Interrupt Register, Port 17E01F00h (and data in AXI memory or other RAM locations) to communicate with each other.

     ________________________________ HID Registers _______________________________

HID Registers (aka Keypad)

      10146000h 2  HID_PAD
      10146002h 2  HID_PAD_IRQ

10146000h - HID_PAD (R)
Same as NDS/DSi, but with X/Y buttons included right in this register.

      0     Button A        (0=Pressed, 1=Released)
      1     Button B
      2     Select
      3     Start
      4     DPAD Right
      5     DPAD Left
      6     DPAD Up
      7     DPAD Down
      8     Button R
      9     Button L
      10    Button X
      11    Button Y
      12-15 Unused (0)

10146002h - HID_PAD_IRQ (R/W)

      0-11  IRQ Buttons     (0=Ignore, 1=Select)
      12-13 Unused (0)
      14    IRQ Enable Flag (0=Disable, 1=Enable, Interrupt 5Bh)
      15    IRQ Condition   (0=Logical OR, 1=Logical AND)

Similar as Port 4000132h on GBA/NDS, used as wake-up source in sleep mode.
Other Inputs

      Circle Pad: Connected to Touchscreen/Sound controller
      Power/Home buttons: see I2C MCU
      Wifi button: see I2C MCU (older 3DS only?)
      Volume/3D Sliders: see I2C MCU
      Accelerometer: see I2C MCU (also includes pedometer step counter)
      Gyroscope: see I2C Gyroscope
      Hinge/Shell: see GPIO (and/or reportedly also I2C MCU)
      DebugPad: See I2C (whatever that is)
      MIC, Cameras, IR, QTM, Charge, SD slot, ROM slot
      Old3DS: NFC reader/writer (external adaptor, instead of New3DS built-in)
      Old3DS: Circle Pad Pro (2nd Circle Pad and R/ZL/ZR buttons, on IR port)
      New3DS: C-stick and ZL/ZR: see I2C (instead of Old3DS's circle pad pro)
      New3DS: NFC built-in (instead of Old3DS's external adaptor)
      New3DS: Head-tracking (whatever that is, probably just camera with IR-LED..?)
      New3DS: Invisible camera IR-LED (unknown how to control/test that)

     ________________________________ MP? Registers _______________________________

MP Registers (local wifi multiplayer?)

      10165206h 2      NDS-Wifi WIFIWAITCNT
      10170000h 8000h  NDS-Wifi WS0 region
      10178000h 8000h  NDS-Wifi WS1 region

These registers are used by MP-module. MP-module seems to be used for 3DS<>DSi local-WLAN communications?

     ______________________________ PARODY Registers ______________________________

Parody Register summary
After reading through many official datasheets and homebrew wiki pages, some of the more amazing 3DS hardware related information goes into 1020B000h...

      1020B000h 4   Certain Register
      1020B014h 4   Assert Register
      1020B034h 4   This Register
      1020B096h 2   Figure Register
      1020B1BFh 1   Byte Register
      1020B2E4h ??  Broken Register
      1020B3D0h 4   Snakish Register

1020B000h - Certain Register
This is the Certain register. The register contains certain bits that are used to enable certain functions, each bit must be set to a certain value. The entire system will hang if used with a certain setting.
1020B014h - Assert Register
Bits in the Assert register get asserted when asserting events are asserted and de-asserted. You are asserted to assert what the asserted information does assert. Assert your dictionary if you can't assert that.
1020B034h - This Register
This register can be used to change the value of this register by writing to this register.
1020B096h - Figure Register
Figure 128 contains information about the Figure register. These register specifications are outlined in Figure 128. See Figure 128 for details about the Figure Register in Figure 128.
Figure 128: Figure 128 is left blank intentionally.
1020B0DCh - ?
1020B1BFh - Byte Register
8-bit Byte value 0,1: 1-ish enable 2:31 must be <this&0x3<=2'b010 +! Pdn SoC value>.
1020B2E4h - Broken Register
This works exactly as described in the broken link on the hardware page.
1020B3D0h - Snakish Register
With Native_firm as of 8.1.0.192 three additional unsigned flags have been introduced to the old(6.5.0.0+) specification which did have specific bits at a certain virtual address and that were not formerly asserted in 1.0.2.30 with *ANY* firm these values must be accumulated with strict binary point comparisions(in the same format as the other bits) prohibitvely permitting abstractions of the reorganized architecture in the *actual* snakish sentences used to describe the entire register space(that CAN be changed in future).

3DS GPIO Registers

     _______________________________ GPIO Registers _______________________________

GPIO Registers

      Address  Width Name
      10147000h 2   GPIO_DATA0
      10147010h 4x1 GPIO_DATA1
      10147014h 2   GPIO_DATA2
      10147020h 4x2 GPIO_DATA3
      10147028h 2   GPIO_DATA4_WIFI
      10147100h ..  Legacy RTC ?

10147000h - GPIO_DATA0_DATA_IN (R?)

      0      Unknown (0=?, 1=Normal) HID-sysmodule, HID PAD state  ;\GPIO services
      1      Touchscreen (0=Pen Down, 1=No)        (IRQ:63h)       ; bitmask 7h
      2      Hinge (0=Shell Open, 1=Shell Closed)  (IRQ:60h/62h?)  ;/
      3      Unused (0)?
      4      Unused (0)?  ;"Only used by Boot11" (uh, but bootrom tests only bit2)
      5-15   Unused (0)?

10147010h - GPIO_DATA1_DATA_IN (R)
10147010h - GPIO_DATA1_DATA_OUT (W)
10147011h - GPIO_DATA1_DIRECTION (R/W)
10147012h - GPIO_DATA1_IRQ_EDGE (R/W) ?
10147013h - GPIO_DATA1_IRQ_ENABLE (R/W)

      0      Headphone (0=None, 1=Connected) gpio:CDC (IRQ:64h) ;\GPIO services
      1      Unknown   (0=?, 1=Normal)                (IRQ:66h) ;/bitmask 18h
      2-7    Unused (0)

10147014h - GPIO_DATA2_DATA_OUT (R/W)

      0      gpio:MCU, gpio:NWM: Wifi?     ;-GPIO services bitmask 20h
      1-15   Unused (0)

10147020h - GPIO_DATA3_DATA_IN (0=Low, 1=High) (R)
10147020h - GPIO_DATA3_DATA_OUT (0=Low, 1=High) (W)
10147022h - GPIO_DATA3_DIRECTION (0=Normal/Input, 1=Output) (R/W)
10147024h - GPIO_DATA3_IRQ_EDGE (0=Falling, 1=Rising) (R/W) ?
10147026h - GPIO_DATA3_IRQ_ENABLE (0=Disable, 1=Enable) (R/W)
Most of these might be IRQ signals from I2C peripherals?
Stuff like QTM, NFC, ir:rst is New3DS only, so Old3DS is probably different here?

      0      C-stick! gpio:CDC, gpio:IR <-- 1 after ir:rst read(IRQ:68h?);\
      1      IrDA IRQ gpio:IR   (0=IRQ)   Boot11(uh, really?)  (IRQ:69h) ;
      2      Gyro IRQ gpio:HID  (1=IRQ, in default cfg)        (IRQ:6Ah?); GPIO
      3      ?        gpio:HID, gpio:IR   used with ir:rst.    (IRQ:6Bh) ; services
      4      ?        gpio:IR send? 1=IR LED enable, 0=disable (IRQ:6Ch) ; bitmask
      5      ?        gpio:IR receive?                         (IRQ:6Dh) ; 3FFC0h
      6      ?        gpio:NFC                                 (IRQ:6Eh) ;
      7      ?        gpio:NFC                                 (IRQ:6Fh) ;
      8      TSC?     gpio:HID  HID-sysmodule, HID PAD state   (IRQ:70h?);
      9      MCU IRQ  gpio:MCU  MCU[10h-1Fh]                   (IRQ:71h) ;
      10     NFC?     gpio:NFC  <-- cleared after NFC read     (IRQ:72h) ;
      11     ?        gpio:QTM   (Twlbg? and/or New3DS?)       (IRQ:73h?);/
      12-15  Unused (0)

10147028h - GPIO_DATA4_DATA_OUT_WIFI (R/W)

      0      Wifi Enable (1=On) ;gpio:MCU, gpio:NWM ;-GPIO services bitmask 40000h
      1-15   Unused (0)

Default GPIO values
After bootrom initialization, these are the values of the registers:

      Address    Value
      10147000h  0003h
      10147010h  00000002h
      10147014h  0000h
      10147020h  00000DFBh
      10147024h  00000000h
      10147028h  0000h

10147100h - Legacy RTC ?
Normally only 10147100h.bit15 is R/W, and the other bits/registers at 101471xxh are all zero. But reportedly they can contain this...

      10147100h 2      RTC_CNT          Control register
     Below are all bytewise bitswapped...
      10147110h 1      RTC_REG_STAT1    Rtc status register 1                  0
      10147111h 1      RTC_REG_STAT2    Rtc status register 2                  1
      10147112h 1      RTC_REG_CLKADJ   Rtc clock adjustment register          6
      10147113h 1      RTC_REG_FREE     The free general purpose rtc register  7
      10147120h 4      RTC_REG_TIME1    Seconds, minutes, hours, day of week
      10147124h 4 (3?) RTC_REG_TIME2    Day, month and year
      10147130h 4 (3?) RTC_REG_ALRMTIM1 Rtc alarm time register 1              4
      10147134h 4 (3?) RTC_REG_ALRMTIM2 Rtc alarm time register 2              5
     Below are for DSi, unknown if they are used/enabled for NDS, too...
      10147140h 4 (3?) RTC_REG_COUNT    Rtc DSi counter register               ex0
      10147150h 1      RTC_REG_FOUT1    Rtc DSi fout register 1                ex1
      10147151h 1      RTC_REG_FOUT2    Rtc DSi fout register 2                ex2
      10147160h 4 (3?) RTC_REG_ALRMDAT1 Rtc DSi alarm date register 1          ex4
      10147164h 4 (3?) RTC_REG_ALRMDAT2 Rtc DSi alarm date register 2          ex5
     In single bytes...
      10147110h 1      RTC_REG_STAT1          Rtc status register 1
      10147111h 1      RTC_REG_STAT2          Rtc status register 2
      10147112h 1      RTC_REG_CLKADJ         Rtc clock adjustment register
      10147113h 1      RTC_REG_FREE           Free general purpose register
      10147114h 0Ch    Unused
      10147120h 1      RTC_REG_TIME_SECOND    Second
      10147121h 1      RTC_REG_TIME_MINUTE    Minute
      10147122h 1      RTC_REG_TIME_HOUR      Hour
      10147123h 1      RTC_REG_TIME_DOW       Day of week
      10147124h 1      RTC_REG_TIME_DAY       Day
      10147125h 1      RTC_REG_TIME_MONTH     Month
      10147126h 1      RTC_REG_TIME_YEAR      Year
      10147127h 09h    Unused
      10147130h 4 (3?) RTC_REG_ALARM1_MINUTE  Alarm 1 Minute
      10147131h        RTC_REG_ALARM1_HOUR    Alarm 1 Hour
      10147132h        RTC_REG_ALARM1_DOW     Alarm 1 Day of week
      10147133h 01h    Unused
      10147134h 4 (3?) RTC_REG_ALARM2_MINUTE  Alarm 2 Minute
      10147135h        RTC_REG_ALARM2_HOUR    Alarm 2 Hour
      10147136h        RTC_REG_ALARM2_DOW     Alarm 2 Day of week
      10147137h 09h    Unused
      10147140h 4 (3?) RTC_REG_COUNT_LSB      Rtc DSi Counter LSB?
      10147141h        RTC_REG_COUNT_MID      Rtc DSi Counter MID
      10147142h        RTC_REG_COUNT_MSB      Rtc DSi Counter MSB?
      10147143h 0Dh    Unused
      10147150h 1      RTC_REG_FOUT1          Rtc DSi Fout register 1
      10147151h 1      RTC_REG_FOUT2          Rtc DSi Fout register 2
      10147152h 0Eh    Unused
      10147160h 4 (3?) RTC_REG_ALARM1_DAY     Rtc DSi Alarm 1 Day
      10147161h        RTC_REG_ALARM1_MONTH   Rtc DSi Alarm 1 Month
      10147162h        RTC_REG_ALARM1_YEAR    Rtc DSi Alarm 1 Year
      10147163h 01h    Unused
      10147164h 4 (3?) RTC_REG_ALARM2_DAY     Rtc DSi Alarm 2 Day
      10147165h        RTC_REG_ALARM2_MONTH   Rtc DSi Alarm 2 Month
      10147166h        RTC_REG_ALARM2_YEAR    Rtc DSi Alarm 2 Year
      10147167h ..     Unused

That is probably for NDS/DSi RTC (4000138h). For GBA Cart RTC see "ARM7_RTC_xxx" registers at 100181xxh.
10147100h - RTC_CNT

      0     Latch STAT1                                                 (W)
      1     Latch STAT2                                                 (W)
      2     Latch CLKADJ                                                (W)
      3     Latch FREE                                                  (W)
      4     Latch TIME                                                  (W)
      5     Latch ALRMTIM1                                              (W)
      6     Latch ALRMTIM2                                              (W)
      7     Latch COUNT                                                 (W)
      8     Latch FOUT1                                                 (W)
      9     Latch FOUT2                                                 (W)
      10    Latch ALRMDAT1                                              (W)
      11    Latch ALRMDAT2                                              (W)
      12    ARM7 Busy? This may be chipselect                           (R)
      13    ARM7 write command received? (writing 1 clears it seems)    (R/ack)
      14    ARM7 read command received? (writing 1 clears it seems)     (R/ack)
      15    DS SIO SI pin (rtc irq pin)                                 (R/W)

Unknown if "Latch" means writing or reading the registers, or if both is somehow supported.
Unknown why RTC IRQ pin is write-able, maybe ARM11 must manually trigger it? But if the ALARM registers are write-only then ARM11 couldn't know their current value (except, by assuming that the written value wasn't changed from NDS side).

3DS Crypto Registers

3DS Crypto - AES Registers
3DS Crypto - SHA Registers
3DS Crypto - RSA Registers
3DS Crypto - PRNG and OTP Registers
3DS Crypto - AES Keyslots
3DS Crypto - AES Key Generator
3DS Crypto - RSA sighax

3DS Crypto - AES Registers

AES Registers (ARM9)

      Address           Name          Byte order  Word order
      10009000h 4   R/W AES_CNT       Little      -          ;-bit22-29 unlike DSi
      10009004h 4   W   AES_BLKCNT    Little      -
      10009008h 4   W   AES_WRFIFO    WordWrite   FifoWrite
      1000900Ch 4   R   AES_RDFIFO    WordRead    FifoRead
      10009010h 1   R/W AES_KEYSEL    -           -          ;\new, unlike DSi
      10009011h 1   R/W AES_KEYCNT    -           -          ;/
      10009020h 16  W   AES_IV        WordWrite   Little
      10009030h 16  W   AES_MAC       WordWrite   Little
      10009040h 48  W   AES_KEY0      WordWrite   Little
      10009070h 48  W   AES_KEY1      WordWrite   Little
      100090A0h 48  W   AES_KEY2      WordWrite   Little
      100090D0h 48  W   AES_KEY3      WordWrite   Little
      10009100h 4   W   AES_KEYFIFO   WordWrite   FifoWrite  ;\
      10009104h 4   W   AES_KEYXFIFO  WordWrite   FifoWrite  ; new, unlike DSi
      10009108h 4   W   AES_KEYYFIFO  WordWrite   FifoWrite  ;/

Most of these registers are same as on DSi:
DSi AES I/O Ports
New features are more keyslots, CBC/ECB modes, optional big-endian mode, and a new Key X/Y scrambler.
10009000h - ARM9 - AES_CNT (R/W)

      0-4   Write FIFO Count    (00h..10h words) (00h=Empty, 10h=Full)          (R)
      5-9   Read FIFO Count     (00h..10h words) (00h=Empty, 10h=Full)          (R)
      10    Write FIFO Flush    (0=No change, 1=Flush)                   (N/A or W)
      11    Read FIFO Flush     (0=No change, 1=Flush)                   (N/A or W)
      12-13 Write FIFO DMA Size (0..3 = 16,12,8,4 words) (2=Normal=8)    (R or R/W)
      14-15 Read FIFO DMA Size  (0..3 = 4,8,12,16 words) (1=Normal=8)    (R or R/W)
      16-18 CCM MAC Size, max(4,(N*2+2)) bytes, usually 7=16 bytes       (R or R/W)
      19    CCM Pass Associated Data to RDFIFO (0=No/Normal, 1=Yes)      (R or R/W)
      20    CCM MAC Verify Source (0=From AES_WRFIFO, 1=From AES_MAC)    (R or R/W)
      21    CCM MAC Verify Result (0=Invalid/Busy, 1=Verified/Okay)             (R)
     Below bits (bit22-29) are other than DSi
      22    Byte order for Word Read  (0=Little endian, 1=Big endian)   (R? or R/W)
      23    Byte order for Word Write (0=Little endian, 1=Big endian)   (R? or R/W)
      24    Word order per Fifo Read  (0=Little first, 1=Big first)     (R? or R/W)
      25    Word order per Fifo Write (0=Little first, 1=Big first)     (R? or R/W)
      26    Key Select        (0=No change, 1=Apply key selected in AES_KEYSEL) (W)
      27-29 Mode (0=CCM decrypt, 1=CCM encrypt, 2=CTR, 3=CTR,
                  4=CBC decrypt, 5=CBC encrypt, 6=ECB decrypt, 7=ECB encrypt)
      30    Interrupt Enable  (0=Disable, 1=Enable IRQ on Transfer End)  (R or R/W)
      31    Start/Enable      (0=Disable/Ready, 1=Enable/Busy)                (R/W)

10009010h - ARM9 - AES_KEYSEL (R/W)

      0-5   Keyslot for encrypt/decrypt, apply via AES_CNT.bit26 (00h..3Fh)   (R/W)
      6-7   Unused (0)

10009011h - ARM9 - AES_KEYCNT (R/W)

      0-5   Keyslot for writes via AES_KEYxyFIFO (04h..3Fh, or 0..3=None)     (R/W)
      6     Key X/Y Scrambler for key 4-3Fh      (0=3DS, 1=DSi)               (R/W)
      7     Flush AES_KEYxyFIFO                  (0=No change, 1=Flush)         (W)

"The hardware key generator is triggered by writing the keyY, which is the only way to trigger it with the 3DS keyslots. The algorithm for generating the normal-key from keyX and keyY is as follows":

      KeyDSi = (((KeyX)       XOR KeyY) + FFFEFB4E295902582A680F5F1A4F3E79h) ROL 42
      Key3DS = (((KeyX ROL 2) XOR KeyY) + 1FF9E9AAC5FE0408024591DC5D52768Ah) ROL 87

Key 0-3 are writeable only via the old DSi-style AES_KEY0..3 registers (not via AES_KEYxyFIFO), and key0-3 are always using the old DSi-style Key scrambler.
10009100h - ARM9 - AES_KEYFIFO - Normal Key (four words)
10009104h - ARM9 - AES_KEYXFIFO - Key X (four words)
10009108h - ARM9 - AES_KEYYFIFO - Key Y (four words)
Whatever, new (unlike DSi).
The Key FIFO's are automatically flushed after each 4 words, and after setting AES_KEYCNT.bit7, and reportedly also when changing the AES_CNT word order.

     __________________________ Notes and DSi Registers __________________________

Notes
When AES_CNT.bit31 is set, then AES_CNT essentially becomes locked and doesn't change when written to. However if AES_CNT.bit26 is "set", keyslot-selection is cued to be handled when AES_CNT.bit31 is cleared.
Clearing AES_CNT.bit31 while the AES engine is doing crypto will result in the AES engine stopping crypto, once it finishes processing the current block.
10009004h - ARM9 - AES_MACEXTRABLKCNT
(CCM-MAC extra data length)>>4, ie. the number of block of CCM-MAC extra data.
10009006h - ARM9 - AES_BLKCNT
(Data length)>>4, ie. the number of blocks to process
10009008h - ARM9 - AES_WRFIFO
1000900Ch - ARM9 - AES_RDFIFO
Reading from AES_RDFIFO when there's no data available in the RDFIFO will result in reading the last word that was in the RDFIFO.
When triggering either RDFIFO or WRFIFO to be flushed, the AES Engine does not clear either buffer.
Word order and endianness can be changed between each read/write to these FIFOs. However changing the word order when writing to WRFIFO can cause the word to be written outside the current block, leaving uninitialized data in its place. Attempts to change endianness or word order are not honored when reading from RDFIFO when no more data is available.
10009020h - ARM9 - AES_IV (16 bytes)
This register specifies the counter (CTR mode), nonce (CCM mode) or the initialization vector (CBC mode) depending on the mode of operation. For CBC and CTR mode this register takes up the full 16 bytes, but for CCM mode the nonce is only the first 12 bytes. The AES engine will automatically increment the counter up to the maximum BLKCNT, after which point it must be manually incremented and set again.
10009030h - ARM9 - AES_MAC (16 bytes)
This register specifies the message authentication code (MAC) for use in CCM mode.
10009040h/10009070h/100090A0h/100090D0h - AES_KEY0/1/2/3
These registers are the same as they were on TWL, and are likely preserved for compatibility reasons. The keyslot is updated immediately after *any* data(u8/u32/...) is written here, which was used on DSi to break the key-generator.
CCM mode pitfall
Non-standard AES-CCM behaviour is observed on Wrap/Unwrap function. According to RFC 3610, the first block B_0 for authentication should be generated from the message length and some other parameters. Using these function, it seems that the message length is aligned up to 16 when generating B_0. This makes the generated MAC not compliant with the standard when (inputsize-noncesize)%16!=0. It is very likely that this non-standard behaviour happens on the hardware level, but not confirmed yet.

      uh, or does it just OMIT that, as on DSi?
      instead of that "aligned" thing?

3DS Crypto - SHA Registers

SHA Registers

      1000A000h 4     ARM9        SHA_CNT           ;\
      1000A004h 4     ARM9        SHA_BLKCNT        ; for ARM9
      1000A040h 20h   ARM9        SHA_HASH          ;
      1000A080h 40h   ARM9        SHA_FIFO          ;/
      10101000h 4     ARM11/ARM9  SHA_CNT           ;\for ARM11 (some registers
      10101004h 4     ARM11/ARM9  SHA_BLKCNT        ; can be also accessed by ARM9,
      10101040h 20h   ARM11/ARM9  SHA_HASH          ; but FIFO and DMA DRQs are
      10301000h 40h   ARM11       SHA_FIFO          ;/working for ARM11 only)

1000A000h/10101000h - SHA_CNT - SHA Control (R/W)

      0     Read: IN_FIFO full   (0=No/ready, 1=Full/Busy) (10h words)          (R)
            Write: First round   (0=No change, 1=Reset BLKCNT and HASH)         (W)
      1     Final round          (0=No/ready, 1=Enable/Busy)                  (R/W)
      2     IN_FIFO DMA Enable   (0=Disable, 1=Enable CDMA DRQ 0Bh)           (R/W)
      3     Byte order of Result (0=Little endian, 1=Big endian/Standard)     (R/W)
      4-5   Mode                 (0=SHA256, 1=SHA224, 2=3=SHA1)               (R/W)
      6-7   Unused (0)  ;reportedly "?" (but actually: always 0)                (?)
      8     OUT_FIFO Enable      (0=No, 1=Readback Mode)           ;\optional (R/W)
      9     OUT_FIFO Status      (0=Empty, 1=Non-empty)            ; readback   (R)
      10    OUT_FIFO DMA Enable  (0=Disable, 1=Enable CDMA DRQ 0Ch);/         (R/W)
      11-15 Unused (0)                                                          (-)
      16-17 Unused (0)  ;reportedly "?" (but actually: always 0)                (?)
      18-31 Unused (0)                                                          (-)

The optional readback mode allows to readback each 40h-byte block from the FIFO, this can reduce memory reads (and temporary memory writes), for example:

      EMMC --> SHA --> AES --> Memory        ;saves 1xMemWrite and 2xMemRead
      EMMC --> AES --> SHA --> Memory        ;saves 1xMemRead

The SHA_IN writing speed is about 62Mbyte/s for SHA256 and SHA224, and 50Mbyte/s for SHA1. Reading source data, and optional forwarding to SHA_OUT may cause extra slowdown.
1000A004h/10101004h - SHA_BLKCNT - SHA Input Length (R/W)

      0-31  Length in bytes (0..FFFFFFFFh)

The length is automatically updated by hardware:

      Length is reset to zero when setting SHA_CNT.bit0 (start).
      Length increments by 40h after each 40h-byte FIFO block.
      Length increments by remaining FIFO size after setting SHA_CNT.bit1 (final).

The hardware does automatically append the length value (and some padding bits) to the data stream before computing the final result.
1000A040h/10101040h - SHA_HASH - State/Result (20h bytes) (R/W)
Contains the SHA state/result. The word order is fixed, the byte order (per 32bit word) depends on SHA_CNT.bit3.
Setting SHA_CNT.bit0 does automatically apply the following initial values:

     SHA256 6A09E667,BB67AE85,3C6EF372,A54FF53A,510E527F,9B05688C,1F83D9AB,5BE0CD19
     SHA224 C1059ED8,367CD507,3070DD17,F70E5939,FFC00B31,68581511,64F98FA7,BEFA4FA4
     SHA1   67452301,EFCDAB89,98BADCFE,10325476,C3D2E1F0,0       ,0       ,0

The values are updated after each 40h-byte FIFO block, and updated once more after final round.
SHA1 leaves the last 3 words unused (set to zero). SHA224 and SHA256 do internally use all 8 words (but the last word is usually omitted when reading the SHA224 result).
1000A080h/10301000h - SHA_FIFO (40h bytes) - SHA_IN (W) and SHA_OUT (R)

      0-7   1st byte        ;\
      8-15  2nd byte        ; data to be checksummed
      16-23 3rd byte        ;
      24-31 4th byte        ;/

The FIFO is mapped to a 40h-byte area at FIFO+0..3Fh. The word address is don't care (one can write all words to FIFO+0, or to FIFO+0,4,8,..,3Ch).
However, 8bit/16bit writes do REQUIRE the lower two addresss bits to match up with the number of previously written bytes (eg. byte writes must go to FIFO+0,1,2,3,4,5,..,3Fh or FIFO+0,1,2,3,0,1,.,3). Writing 8bit/16bit is normally needed only for the last block before setting final flag (and only if the length isn't a multiple of 40h). Writing 8bit/16bit may be also needed if the data comes from an odd source address (but that would slowdown everything).
Invalid Operations with/without Data Abort

      Reading FIFO when CNT.bit8=0 returns ZERO (readback disabled)
      Reading FIFO when CNT.bit8=1 and FIFO empty causes Data Abort (enabled+empty)

Untested...

      Writing FIFO when FIFO full... is ignored? or data abort?
      Writing 32bit to FIFO content is odd (not N*4 bytes)... causes what?
      Writing 32bit to FIFO already contains 3Dh..3Fh bytes... causes what?

3DS Crypto - RSA Registers

RSA Registers (ARM9)

      1000B000h 4    R/W RSA_CNT        Control/status and keyslot select
      1000B0F0h 4    ?   RSA_UNKNOWN    Unknown
      1000B1x0h 4    R/W RSA_SLOTCNT_x  Keyslot 0..3 control/status (x=0..3)
      1000B1x4h 4    R   RSA_SLOTSIZE_x Keyslot 0..3 size/status    (x=0..3)
      1000B200h 4    W   RSA_EXPFIFO    Exponent (10001h, or private key) ;\for
      1000B204h FCh  W   RSA_EXPFIFO    Mirrors of above                  ; current
      1000B400h 100h R/W RSA_MOD        Modulus (public key)              ;/keyslot
      1000B800h 100h R/W RSA_DATA       Incoming Data and Result

1000B000h - ARM9 - RSA_CNT (R/W)

      0     Start/Busy (0=Idle/Ready, 1=Enable/Busy)
      1     IRQ Enable (0=Disable, 1=Enable, set ARM9 IF.bit22 when Ready)
      2-3   Unused (0)
      4-5   Keyslot    (0..3=Key 0-3)   ;for Start/Busy and RSA_MOD,EXPFIFO
      6-7   Unused (0)
      8     Byte order (0=Little endian, 1=Big Endian) ;for RSA_MOD,DATA,EXPFIFO
      9     Word order (0=Little endian, 1=Big Endian) ;for RSA_MOD,DATA
      10-31 Unused (0)

1000B0F0h - ARM9 - RSA_UNKNOWN (R and/or W)

      0-28  Unknown/unused?   (always zero)
      29    Unknown/readonly? (always set)
      30-31 Unknown/unused?   (always zero)

The bootroms writes zero in RSA IRQ init, so some bits might be write-only? Writing seems to have no effect on anything though.
1000B100h+(0..3)*10h - ARM9 - RSA_SLOTCNT_0..3 (R/W)

      0     Read: Exponent Status (0=Bad=LessThan4orOdd, 1=Good=4orMoreAndEven) (R)
            Write: Clear RSA_SLOTSIZE/EXPFIFO (0=Clear, 1=No Change)            (W)
      1     Disable RSA_EXPFIFO Writes        (0=Normal, 1=DataAbort)         (R/W)
      2     Disable RSA_MOD Reads             (0=Normal, 1=DataAbort)         (R/W)
      3-30  Unused (0)
      31    Disable RSA_SLOTCNT_x Writes      (0=Normal, 1=Disable/permanent) (R/w)

Bit1,2 can be changed only if Status Bit0 was set (Good=4orMoreAndEven).
1000B104h+(0..3)*10h - ARM9 - RSA_SLOTSIZE_0..3 (R)

      0-31  Number of words written to EXPFIFO (range 0..40h)

Indicates the EXP size (and implied: the MOD and DATA sizes). Whilst that number is important, programmers should usually know how many words they had used, without needing to use the SLOTSIZE register.
1000B200h - ARM9 - RSA_EXPFIFO - Exponent; usually 10001h, or Private Key (W)
1000B204h..1000B2FFh - ARM9 - RSA_EXPFIFO mirrors (W)

      0-31  FIFO, in current byte-order, to be written MSW first (max 40h words)

The number of words written to EXPFIFO does imply the size of the MOD and DATA values (that makes sense for private exponents, but the public exponent 10001h must be padded with leading zeroes, and then followed by 10001h in last word (aka 01000100h for big-endian).
The RSA hardware wants the number of words to be an even number in range of 4..40h, aka a multiple of 8 bytes in range 10h..100h (and if so, sets SLOTCNT.bit0).
1000B400h..1000B4FFh - ARM9 - RSA_MOD - Modulus; Public Key (R/W)

      100h-byte area, in currently selected byte/word-order, for current keyslot

The upper bits are unused/don't care when SLOTSIZE<40h.
1000B800h..1000B8FFh - ARM9 - RSA_DATA (100h bytes) (R/W)

      100h-byte area, in currently selected byte/word-order

Contains the data that is to be encrypted/decrypted, and contains the result after completion.
The upper bits are unused/don't care when SLOTSIZE<40h.
RSA Timing Examples (versus 67MHz timer)

      0.9ms (E475h clks)   Public key, 80h-bytes (DSi-style)
      3.3ms (3571Dh clks)  Public key, 80h-bytes zeropadded to 100h-bytes size
      3.3ms (3574Ah clks)  Public key, 100h-bytes (3DS-style)
      200ms (CE59A5h clks) Private key, 100h-bytes (3DS-style)

Invalid Operations with/without Data Abort

      Reading MOD or DATA when busy (and maybe also on writing?)  --> Data Abort
      Reading MOD when disabled in SLOTCNT                        --> Data Abort
      Writing EXPFIFO when disabled in SLOTCNT                    --> Data Abort
      Writing more than 40h words to EXPFIFO                      --> Data Abort
      Reading EXPFIFO or reading unused registers like 1000B5xxh  --> Returns Zero

Keyslot 0..3 usage
During boot, the bootrom uses the following PUBLIC keys (100h byte modulus, with exponent 10001h):

      Slot 0 uninitialized                     (unused)
      Slot 1 retail=FFFFB1E0h, debug=FFFFC4E0h (for FIRM from eMMC)
      Slot 2 retail=FFFFB2E0h, debug=FFFFC5E0h (for FIRM from Wifi-Flash/NDS-Cart)
      Slot 3 retail=FFFFB0E0h, debug=FFFFC3E0h (for NCSD from eMMC)

After boot, the bootrom does replace the above keys by four PRIVATE keys (with 100h byte modulus, and 100h byte exponent):

      Slot 0 retail=FFFFB3E0h, debug=FFFFC6E0h ;\Hardware slots (modulus+exponent)
      Slot 1 retail=FFFFB5E0h, debug=FFFFC8E0h ; (the modulus are also stored in
      Slot 2 retail=FFFFB7E0h, debug=FFFFCAE0h ; RAM at ITCM+3D00h+(0..3)*100h)
      Slot 3 retail=FFFFB9E0h, debug=FFFFCCE0h ;/
      Slot 4 retail=FFFFBBE0h, debug=FFFFCEE0h ;\
      Slot 5 retail=FFFFBDE0h, debug=FFFFD0E0h ; RAM slots (modulus+exponent are
      Slot 6 retail=FFFFBFE0h, debug=FFFFD2E0h ; stored at ITCM+4100h+(0..3)*200h)
      Slot 7 retail=FFFFC1E0h, debug=FFFFD4E0h ;/

Later on, the firmware does replace some slots by other keys:

      Slot 0 Arbitrary (uh?)
      Slot 1 CXI access desc (following the exheader, uh?)
      Slot 2 Unused (contains the private key from bootrom)
      Slot 3 Unused (contains the private key from bootrom)

RSA Basics and Differences to DSi
The 3DS RSA hardware is more or less same as the DSi RSA BIOS functions, see there for general info about RSA maths and RSA padding:
BIOS RSA Functions (DSi only)
Apart from being hardware-implemented, the 3DS is usually using 100h-bytes (instead 80h), with SHA256 signatures (instead SHA1), and with OpenPGP headers (instead raw padding).
Blurb
Writing to RSA_MOD does not change the exponent written with RSA_EXPFIFO. An attack based on the Pohlig-Hellman algorithm exists to "read" the contents of RSA_EXPFIFO as a result (see 3DS System Flaws).
RSA Overview
The RSA module is essentially a hardware-accelerated modular exponentiation engine. It is specially optimized for RSA applications, so its behavior can be incoherent when RSA's invariants are broken.
The PKCS (Public-Key Cryptography Standards) message padding must be manually checked by software, as hardware will only do raw RSA operations.
Observed edge cases

      "if 2 divides mod, output == 0"

uh, how to "divide" a "mod" ?
uh, for mod2, remainder SHOULD be 0 or 1 (or is it ALWAYS 0 here?)
uh, also, MOD may be required to be bigger than DATA?

3DS Crypto - PRNG and OTP Registers

     _______________________________ PRNG Registers _______________________________

PRNG Registers ... Pseudo Random Generator? Boot9, Process9

      10011000h 4  Random (changes on each read)
      10011010h 4  Random (changes on each read)
      10011020h 4  Random (constant)

Used as entropy-source for seeding random number generators.

     _______________________________ OTP Registers ________________________________

OTP Registers

      10012000h 100h  Encrypted 3DS OTP  (R)
      10012100h 8     DSi OTP Console ID (R/W?)

Access to this region is disabled once the ARM9 writes 02h to CFG9_SYSPROT9.
10012000h - 100h bytes - Encrypted 3DS OTP (R)
Console-unique data encrypted with AES-CBC. The normalkey and IV are stored in Boot9 (retail/devunit have seperate normalkey+IV for this).
10012100h - 8 bytes - DSi OTP Console ID (R/W?)
Before writing CFG9_SYSPROT9 bit1, the ARM9 copies the 8-byte TWL Console ID here. This sets the registers at 4004D00h for ARM7.

      [10012100h] = DecryptedOTP[008h] xor B358A6AFh or 80000000h
      [10012104h] = DecryptedOTP[00Ch] xor 08C267B7h

Decrypted OTP

      000h 90h   Copied into ITCM. The encrypted version of this is what
                    New3DS-arm9loader hashes for key-generation.
      000h 4     Always DEADB00Fh
      004h 4     DeviceId (aka Console ID, used in tickets)
      008h 10h   Fall-back keyY used for movable.sed keyY when
                    movable.sed doesn't exist in NAND (the last(???) two words
                    here are used on retail for generating console-unique TWL
                    keydata/etc).
                    This is also used for "LocalFriendCodeSeed", etc.
      018h 1     CTCert byte order? (usually 05h)
      019h 1     CTCert issuer type:
                   zero = retail  ("Nintendo CA - G3_NintendoCTR2prod")
                   non-zero = dev ("Nintendo CA - G3_NintendoCTR2dev")
      01Ah 6     Manufacturing date (year-1900, month, day, hour, minute, second)
      020h 4     CTCert ECDSA exponent (byte-swapped when OTP[018h]>=5)
      024h 2     Zero?
      026h 1Eh   CTCert ECDSA private key
      044h 3Ch   CTCert ECDSA signature
      080h 10h   Zerofilled
      090h 1Ch   Seed 1 for AES keys ;<-- used for console-unique AES keys
      0ACh 1Ch   Seed 2 for AES keys ;\
      0C8h 1Ch   Seed 3 for AES keys ; not actually used  ;\overlaps SHA256
      0E4h 1Ch   Seed 4 for AES keys ;/                   ;/(see below)
      0E0h 20h   SHA256 hash across [000h..0DFh]

OTP Blurp
After decryption, the first 90h-bytes of plaintext are copied to ITCM+3800h at 01FFB800h aka 07FFB800h if hash verification passes.
On FIRM versions prior to 3.0.0-X, this region was left unprotected. On versions since 3.0.0-X, this has been fixed, and the region disable is now done by Kernel9 after doing console-unique TWL keyinit, by setting bit1 of CFG9_SYSPROT9. However, with the New3DS FIRM ARM9 binary this is now done in the FIRM ARM9 binary loader, which also uses the 10012000h region for New 3DS key generation.
On development units (UNITINFO != 0) ARM9 uses the first 8-bytes from 10012000h for the TWL Console ID. This region doesn't seem to be used by NATIVE_FIRM on retail at all, besides New3DS key-generation in the ARM9-loader.

3DS Crypto - AES Keyslots

AES Keyslot Usage

      00h      DSi                                       ;\
      01h      DSi                                       ; DSi keys (little-endian,
      02h      DSi                                       ; with DSi key X/Y)
      03h      eMMC key for DSi MBR and FAT filesystems  ;/
      04h      eMMC key for Old3DS MBR and FAT filesystem
      05h      eMMC key for New3DS MBR and FAT filesystem (keyY from FIRM)
      06h      eMMC key for FIRM partitions
      07h      eMMC key for GBA savegame partition
      08h-09h  Unused
      0Ah      DSiWare export (encrypted 10h-byte zeroes in DSiWare_Exports header)
      0Bh      AES-CMAC key (for emmc:\dbs images, and emmc:\private\movable.sed)
      0Ch      Unused
      0Dh      SSL-certificate key (see ClCertA)
      0Eh-10h  Unused
      11h      Temporary keyslot (used by FIRM)
      12h-13h  Unused
      14h      Unknown (initialized by v5.0.0-11 and up)
      15h      New3DS arm9 FIRM binary loader
      16h      New3DS arm9 FIRM binary loader (v9.5.0 and up)
      17h      Unused
      18h      New3DS Second NCCH key (when NCCH[18Bh]=0Ah)
      19h      New3DS Gamecard savedata AES-CMAC key (when [ROM?-]NCSD=what?)
      1Ah      New3DS Gamecard savedata Actual key   (when [ROM?-]NCSD=what?)
      1Bh      New3DS Second NCCH key (when NCCH[18Bh]=0Bh)
      1Ch-1Fh  New3DS Unused keys (initialized, but not used yet)
      20h-23h  Unused
      24h      GBA savegame AES-CMAC key
      25h      Second NCCH key (when NCCH[18Bh]=01h)
      26h-2Bh  Unused
      2Ch      First NCCH key (also 2nd key, when NCCH[18Bh]=00h)
      2Dh      UDS local-WLAN CCMP key
      2Eh      Streetpass key
      2Fh      v6.0 save key
      30h      AES-CMAC key (for emmc:\data\ and sd:\Nintendo 3DS\...)
      31h      APT wrap key
      32h      Unknown
      33h      Gamecard savedata AES-CMAC (New3DS alternately uses keyslot 19h)
      34h      SD key (for all data in "sd:\Nintendo 3DS\<ID0>\<ID1>\")
      35h      Movable.sed key (movable.sed & AES-CBC MAC with import/export cmds)
      36h      Used by friends module
      37h      Gamecard savedata Actual key (New3DS alternately uses keyslot 1Ah)
      38h      BOSS key
      39h      Temporary keys (Download Play & NFC key for generating Amiibo keys)
      3Ah      DSiWare export (for calculating AES-CMACs for SD DSiWare_Exports)
      3Bh      CTRCARD key (for decrypting seed via AES-CCM)
      3Ch      Unused
      3Dh      Common key (used to decrypt title keys in Ticket)
      3Eh      Unused
      3Fh      Temporary keyslot (used by bootrom)

Random notes
After writing to a keyslot, the keyslot must be selected again (write AES_KEYSEL + set AES_CNT bit26), even when writing to the same keyslot. Writing the last word to a key FIFO immediately after selecting a keyslot will not affect the keyslot keydata that gets used at that time, the new keydata will not get used until the keyslot gets selected again.
Writing to the key FIFOs with byte writes results in the AES engine converting the byte to a word (word=byte*01010101h). The result is the same regardless of which FIFO register byte was written to.
The key FIFOs can be written simultaneously. For example, executing the following will result in the keyX and keyY being set to all-zero (unknown for normalkey): memset(0x10009100, 0, 0x100); uh, does that mean there are mirrors at 1000910Ch and up?
Each key FIFO has a 10h-byte tmp-buffer for storing the words written to that FIFO. Once the last word is written to a key FIFO, the filled tmp-buffer is then written to the key-data for the keyslot selected by AES_KEYCNT at the time the last word was written.
FIRM-launch key clearing
Starting with 9.0.0-20 the Process9 FIRM-launch code now "clears" the following AES keyslots, with certain keydata by writing the normal-key: 0x15 and 0x18-0x20. These are the keyslots used by the New3DS FIRM arm9bin loader (minus keyslot 0x11), the New3DS Process9 does this too.

3DS Crypto - AES Key Generator

Decrypt OTP and get otp_seed (and rom_seed for retail/debug)

      if [10010010h]=00h then otp_keyiv=FFFFD6E0h else otp_keyiv=FFFFD700h
      if [10010010h]=00h then rom_seed=FFFFD860h  else rom_seed=FFFFDC60h
      aes_setkey_normal(key=otp_keyiv+00h)
      aes_CBC_decrypt(iv=otp_keyiv+10h, src=10012000h, dst=decrypted_otp, len=100h)
      sha256(src=decrypted_otp, dst=temp, len=E0h)
      if [temp+0..1Fh]=[decrypted_otp+E0h..FFh] then otp_okay=1 else otp_okay=0
      if otp_okay=1 then otp_seed=decrypted_otp+90h else otp_seed=10012000h
      if otp_okay=1 then copy [decrypted_otp+0..8Fh] to [ITCM+3800h..388Fh]

Generate bootrom keys (using above otp_seed and rom_seed)

      sha256(src=otp_seed(00h..1Bh)+rom_seed(00h..23h), dst=temp, len=40h=1Ch+24h)
      aes_setkey_xy(key_x=temp+00h, key_y=temp+10h)
      aes_CBC_encrypt(iv=rom_seed+24h, src=rom_seed+34h, dst=temp, len=40h)
      key_x.00h-03h = uninitialized
      key_x.04h-07h = temp+00h
      key_x.08h-0Bh = temp+10h
      key_x.0Ch-0Fh = temp+20h
      key_x.10h     = temp+30h
      key_x.11h-13h = uninitialized
     ;sha256(src=otp_seed(1Ch..37h)+rom_seed(74h..97h), dst=temp, len=40h=1Ch+24h)
     ;DO NOT: aes_setkey_xy(key_x=temp+00h, key_y=temp+10h)
      aes_CBC_encrypt(iv=rom_seed+98h, src=rom_seed+A8h, dst=temp, len=40h)
      key_x.14h     = temp+00h
      key_x.15h     = temp+10h
      key_x.16h     = temp+20h
      key_x.17h     = temp+30h
     ;sha256(src=otp_seed(38h..53h)+rom_seed(B8h..DBh), dst=temp, len=40h=1Ch+24h)
     ;DO NOT: aes_setkey_xy(key_x=temp+00h, key_y=temp+10h)
      aes_CBC_encrypt(iv=rom_seed+DCh, src=rom_seed+ECh, dst=temp, len=40h)
      key_x.18h-1Bh = temp+00h
      key_x.1Ch-1Fh = temp+10h
      key_x.20h-23h = temp+20h
      key_x.24h     = temp+30h
      key_x.25h-27h = uninitialized
     ;sha256(src=otp_seed(54h..6Fh)+rom_seed(12Ch..14Fh),dst=temp, len=40h=1Ch+24h)
     ;DO NOT: aes_setkey_xy(key_x=temp+00h, key_y=temp+10h)
      aes_CBC_encrypt(iv=rom_seed+150h, src=rom_seed+160h, dst=temp, len=40h)
      key_x.28h     = temp+00h
      key_x.29h     = temp+10h
      key_x.2Ah     = temp+20h
      key_x.2Bh     = temp+30h
      key_x.2Ch-2Fh = rom_seed+170h         ;\
      key_x.30h-33h = rom_seed+180h         ;
      key_x.34h-37h = rom_seed+190h         ;
      key_x.38h-3Bh = rom_seed+1A0h         ; fixed key X values
      key_x.3Ch     = rom_seed+1B0h         ;
      key_x.3Dh     = rom_seed+1C0h         ;
      key_x.3Eh     = rom_seed+1D0h         ;
      key_x.3Fh     = rom_seed+1E0h         ;/
      key_y.00h-03h = uninitialized
      key_y.04h     = rom_seed+1F0h         ;\
      key_y.05h     = rom_seed+200h         ;
      key_y.06h     = rom_seed+210h         ;
      key_y.07h     = rom_seed+220h         ; fixed key Y values
      key_y.08h     = rom_seed+230h         ;
      key_y.09h     = rom_seed+240h         ;
      key_y.0Ah     = rom_seed+250h         ;
      key_y.0Bh     = rom_seed+260h         ;/
      key_y.0Ch-3Eh = uninitialized
      key_y.3Fh     = as set for above CBC encrypt
      key.00h-03h   = uninitialized
      key.04h-0Bh   = uninitialized (or are they set via above key X/Y combo?)
      key.0Ch-0Fh   = rom_seed+270h         ;\
      key.10h       = rom_seed+280h         ;
      key.11h-13h   = uninitialized         ;
      key.14h       = rom_seed+290h         ;
      key.15h       = rom_seed+2A0h         ;
      key.16h       = rom_seed+2B0h         ;
      key.17h       = rom_seed+2C0h         ;
      key.18h-1Bh   = rom_seed+2D0h         ; fixed normal key values
      key.1Ch-1Fh   = rom_seed+2E0h         ;
      key.20h-23h   = rom_seed+2F0h         ;
      key.24h       = rom_seed+300h         ;
      key.25h-27h   = uninitialized         ;
      key.28h       = rom_seed+300h, too    ;
      key.29h       = rom_seed+310h         ;
      key.2Ah       = rom_seed+320h         ;
      key.2Bh       = rom_seed+330h         ;
      key.2Ch-2Fh   = rom_seed+340h         ;
      key.30h-33h   = rom_seed+350h         ;
      key.34h-37h   = rom_seed+360h         ;
      key.38h       = rom_seed+370h         ;
      key.39h-3Bh   = uninitialized         ;
      key.3Ch       = rom_seed+370h, too    ;
      key.3Dh       = rom_seed+380h         ;
      key.3Eh       = rom_seed+390h         ;
      key.3Fh       = rom_seed+3A0h         ;/
      [FFF00618h]   = rom_seed+3A0h, too    ;-copy of normal key 3Fh
      [temp] = fillword(rom_seed+3B0h)      ;-dummy/fill temp buffer on stack

     ___________ Further important keys (changed after init by bootrom) ___________

Misc keys:

      key_y.05h = 4D,80,4F,4E,99,90,19,46,13,A2,04,AC,58,44,60,BE  ;by New3DS FIRM
      key_y.30h = movable.sed[110h..11Fh]
      key_y.34h = movable.sed[110h..11Fh]
      key_y.3Ah = movable.sed[110h..11Fh]

NCCH retail keys:

      key_x.25h = CE,E7,D8,AB,30,C0,0D,AE,85,0E,F5,E3,82,AC,5A,F3 ;NCCH firm 7.0
      key_x.18h = 82,E9,C9,BE,BF,B8,BD,B8,75,EC,C0,A0,7D,47,43,74 ;NCCH firm 9.3
      key_x.1Bh = 45,ad,04,95,39,92,c7,c8,93,72,4a,9a,7b,ce,61,82 ;NCCH firm 9.6

NCCH debug keys:

      fix_sys   = 52,7C,E6,30,A9,CA,30,5F,36,96,F3,CD,E9,54,19,4B ;fixed system key
      fix_zero  = 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00 ;fixed zero key
      key_x.25h = 81,90,7A,4B,6F,1B,47,32,3A,67,79,74,CE,4A,D7,1B ;NCCH firm 7.0
      key_x.18h = 30,4B,F1,46,83,72,EE,64,11,5E,BD,40,93,D8,42,76 ;NCCH firm 9.3
      key_x.1Bh = 6C,8B,29,44,A0,72,60,35,F9,41,DF,C0,18,52,4F,B6 ;NCCH firm 9.6

Ticket Keys (aka "Common" keys)
The ticket keys in FIRM are as so:

      55,A3,F8,72,BD,C8,0C,55,5A,65,43,81,13,9E,15,3B  ;key_3Dh.normal.0 (debug)
      D0,7B,33,7F,9C,A4,38,59,32,A2,E2,57,23,23,2E,B9  ;key_3Dh.y.0 (retail)
      0C,76,72,30,F0,99,8F,1C,46,82,82,02,FA,AC,BE,4C  ;key_3Dh.y.1 (retail+debug)
      C4,75,CB,3A,B8,C7,88,BB,57,5E,12,A1,09,07,B8,A4  ;key_3Dh.y.2 (retail+debug)
      E4,86,EE,E3,D0,C0,9C,90,2F,66,86,D4,C0,6F,64,9F  ;key_3Dh.y.3 (retail+debug)
      ED,31,BA,9C,04,B0,67,50,6C,44,97,A3,5B,78,04,FC  ;key_3Dh.y.4 (retail+debug)
      5E,66,99,8A,B4,E8,93,16,06,85,0F,D7,A1,6D,D7,55  ;key_3Dh.y.5 (retail+debug)

Retail Normal Keys (after mangling above with bootrom's retail Key_3Dh.X):

      64,C5,FD,55,DD,3A,D9,88,32,5B,AA,EC,52,43,DB,98  ;key_3Dh.0.retail (app)
      4A,AA,3D,0E,27,D4,D7,28,D0,B1,B4,33,F0,F9,CB,C8  ;key_3Dh.1.retail (sys)
      FB,B0,EF,8C,DB,B0,D8,E4,53,CD,99,34,43,71,69,7F  ;key_3Dh.2.retail
      25,95,9B,7A,D0,40,9F,72,68,41,98,BA,2E,CD,7D,C6  ;key_3Dh.3.retail
      7A,DA,22,CA,FF,C4,76,CC,82,97,A0,C7,CE,EE,EE,BE  ;key_3Dh.4.retail
      A5,05,1C,A1,B3,7D,CF,3A,FB,CF,8C,C1,ED,D9,CE,02  ;key_3Dh.5.retail

Debug Normal Keys (after mangling above with bootrom's debug Key_3Dh.X):

      55,A3,F8,72,BD,C8,0C,55,5A,65,43,81,13,9E,15,3B  ;key_3Dh.0.debug
      44,34,ED,14,82,0C,A1,EB,AB,82,C1,6E,7B,EF,0C,25  ;key_3Dh.1.debug
      F6,2E,3F,95,8E,28,A2,1F,28,9E,EC,71,A8,66,29,DC  ;key_3Dh.2.debug
      2B,49,CB,6F,99,98,D9,AD,94,F2,ED,E7,B5,DA,3E,27  ;key_3Dh.3.debug
      75,05,52,BF,AA,1C,04,07,55,C8,D5,9A,55,F9,AD,1F  ;key_3Dh.4.debug
      AA,DA,4C,A8,F6,E5,A9,77,E0,A0,F9,E4,76,CF,0D,63  ;key_3Dh.5.debug

3DS Crypto - RSA sighax

sighax is a set of fake RSA signatures which are causing the bootrom to always pass RSA checks.
How it works
derrek's sighax relies on some bugs in the bootrom RSA signature verification. RSA doesn't throw errors when decrypting a wrong signature with wrong key (instead, it does just output "random" gibberish). The decrypted signature should normally consist of leading FFh-padding bytes, a header, and a SHA checksum.
However, the 3DS bootrom doesn't insist on the padding bytes, and it does ignore most of the header bytes. Finally, it does allow the header size to be as large as occupying the whole 100h-byte signature area, which results in the SHA value being read from next higher address AFTER the signature area - and the bootrom happens to store the computed SHA at that location (causing the bootrom to compare the computed SHA against itself, instead of against of what should have been the decrypted SHA value).
Alltogether, brute-forcing requires only 6 specific bytes in the decrypted signature (and the remaining 250 bytes are don't care).
The bootrom uses three RSA keys for different retail signatures, and another three RSA keys for debug version.
NCSD Signature (in eMMC)
The eMMC's NCSD Header is unencrypted, and can be changed without needing any AES keys (however, booting custom code requires to change FIRM, not NCSD).

      6CF52F89F378120BFA4E1061D7361634D9A254A4F57AA5BD9F2C30934F0E68CB ;\
      E6611D90D74CAAACB6A995565647333DC17092D320131089CCCD6331CB3A595D ;
      1BA299A32FF4D8E5DD1EB46A2A57935F6FE637322D3BC4F67CFED6C2254C089C ; retail
      62FA11D0824A844C79EE5A4F273D46C23BBBF0A2AF6ACADBE646F46B86D1289C ; version
      7FF7E816CFDA4BC33DFF9D175AC69F72406C071B51F45A1ACB87F168C177CB9B ;
      E6C392F0341849AE5D510D26EEC1097BEBFB9D144A1647301BEAF9520D22C55A ;
      F46D49284CC7F9FBBA371A6D6E4C55F1E536D6237FFF54B3E9C11A20CFCCAC0C ;
      6B06F695766ACEB18BE33299A94CFCA7E258818652F7526B306B52E0AED04218 ;/
      53CB0E4EB1A6FF84284BE0E7385AB4A686A8BBCBC16102479280E0583655D271 ;\
      3FE506FAEE74F8D10F1220441CC2FF5D6DDE99BE79C19B386CAF68D5EB8CED1A ;
      AB4D243C5F398680D31CD2E3C9DD5670F2A88D563B8F65F5B234FD2EBB3BE44A ; debug
      3B6C302722A2ADFB56AE3E1F6417BDEC1E5A86AABBAFBE9419ACA8FDCD45E2CD ; version
      F1EB695F6EA87816122D7BE98EEF92C0814B16B215B31D8C813BB355CEA8138F ;
      B3BF2374246842CD91E1F9AAFF76878617CE02064777AEA0876A2C245C784341 ;
      CDEE90D691745908A6FF9CE781166796F9F1238F884C84D6F1EEBB2E40B4BCA0 ;
      0A7B1E913E0980D29FF6061D8AA944C663F2638127F7CCAB6FC71538471A5138 ;/

FIRM Signature (in eMMC)
The eMMC's FIRM Header is encrypted via console-specific AES keys. Patching this area requires access to the corresponding AES keyslot (or knowing the OTP seed value that was used to generate that key). Alternately, knowing the decrypted content of the currently installed firmware version will also help (then one can simply XOR the encrypted bytes by old & new unencrypted bytes).

      B6724531C448657A2A2EE306457E350A10D544B42859B0E5B0BED27534CCCC2A ;\
      4D47EDEA60A7DD99939950A6357B1E35DFC7FAC773B7E12E7C1481234AF141B3 ;
      1CF08E9F62293AA6BAAE246C15095F8B78402A684D852C680549FA5B3F14D9E8 ; retail
      38A2FB9C09A15ABB40DCA25E40A3DDC1F58E79CEC901974363A946E99B4346E8 ; version
      A372B6CD55A707E1EAB9BEC0200B5BA0B661236A8708D704517F43C6C38EE956 ;
      0111E1405E5E8ED356C49C4FF6823D1219AFAEEB3DF3C36B62BBA88FC15BA864 ;
      8F9333FD9FC092B8146C3D908F73155D48BE89D72612E18E4AA8EB9B7FD2A5F7 ;
      328C4ECBFB0083833CBD5C983A25CEB8B941CC68EB017CE87F5D793ACA09ACF7 ;/
      88697CDCA9D1EA318256FCD9CED42964C1E98ABC6486B2F128EC02E71C5AE35D ;\
      63D3BF1246134081AF68754787FCB922571D7F61A30DE4FCFA8293A9DA512396 ;
      F1319A364968464CA9806E0A52567486754CDDD4C3A62BDCE255E0DEEC230129 ; debug
      C1BAE1AE95D786865637C1E65FAE83EDF8E7B07D17C0AADA8F055B640D45AB0B ; version
      AC76FF7B3439F5A4BFE8F7E0E103BCE995FAD913FB729D3D030B2644EC483964 ;
      24E0563A1B3E6A1F680B39FC1461886FA7A60B6B56C5A846554AE648FC46E30E ;
      24678FAF1DC3CEB10C2A950F4FFA2083234ED8DCC3587A6D751A7E9AFA061569 ;
      55084FF2725B698EB17454D9B02B6B76BE47ABBE206294366987A4CAB42CBD0B ;/

FIRM Signature (in WifiFlash or NtrCard)
These FIRM Headers are encrypted via fixed AES keys, and can be thus generated without knowing console-specific keys. However, there are some hardware requirements:
WifiFlash must have the write-protect pin disabled, and offset 400h must be writeable (this does require a SPI flash chip with 128Kbyte or more; and won't work with the normal built-in 4Kbyte chip). And, the eMMC firm sections must be 'destroyed' to trigger WifiFlash booting.
NtrCard requires a NDS flashcart, and support for rewriting its "bootmenu" memory region. And, key combination Start+Select+X with shell closed is needed to trigger NtrCard booting.

      37E96B10BAF28C74A710EF35824C93F5FBB341CEE4FB446CE4D290ABFCEFACB0 ;\
      63A9B55B3E8A65511D900C5A6E9403AAB5943CEF3A1E882B77D2347942B9E9EB ;
      0D7566370F0CB7310C38CB4AC940D1A6BB476BCC2C487D1C532120F1D2A37DDB ; retail
      3E36F8A2945BD8B16FB354980384998ECC380CD5CF8530F1DAD2FD74BA35ACB9 ; version
      C9DA2C131CB295736AE7EFA0D268EE01872EF033058ABA07B5C684EAD60D76EA ;
      84A18D866307AAAAB764786E396F2F8B630E60E30E3F1CD8A67D02F0A88152DE ;
      7A9E0DD5E64AB7593A3701E4846B6F338D22FD455D45DF212C5577266AA8C367 ;
      AE6E4CE89DF41691BF1F7FE58F2261F5D251DF36DE9F5AF1F368E650D576810B ;/
      18722BC76DC3602E2C0171F3BCA12AB40EA6D112AEFBECF4BE7A2A58FF759058 ;\
      A93C95CDA9B3B676D09A4E4C9E842E5C68229A6A9D77FAC76445E78EB5B363F8 ;
      C66B166BE65AFAE40A1485A364C2C13B855CEEDE3DFEACEC68DD6B8687DD6DF8 ; debug
      B6D3213F72252E7C03C027EE6079F9C5E0290E5DB8CA0BBCF30FCAD72EB637A1 ; version
      70C4A2F41D96BF7D517A2F4F335930DC5E9792D78EDFB51DC79AD9D7A4E7F1ED ;
      4D5A5C621B6245A7F1652256011DC32C49B955304A423009E2B78072CEBC12B3 ;
      85B72F926F19318D64075F09278FBA8448FD2484B82654A55D064542A8F5D9F9 ;
      828CDA5E60D31A40CF8EF18D027310DA4F807988BC753C1EB3B3FC06207E84DE ;/

SIGHAX.BIN
This signature is for unknown purpose (probably Retail eMMC FIRM, too):

      6EFF209C8F4AF61F062413D602CA6B4DA1EB5AB9B6F1A2AB226A711DA2CCC27C
      74DE1741143BF69058284CAF444F92A45AAFD5A068043323D48AF1D0EC05564E
      BC79B55134E91A86C3788C97BC29D5A58A8A45255843B89122C7804542F72677
      C8DA5EB7429BAF18F7A8B02E8BB940FE990E9DC97EDCF49DDB18092C28206E74
      6753CC7C6E92362AA8D546B38D9E8D4311A6B1930DA14897807E304B5E1EC085
      6EEFD62CEAEEF28B08BD80397A181560AE6FCE39D09C39DC3DED8C870AB6ABCE
      2894940C0E9C4174F0131A0DA0747C4A7A42C9EC3487F109E252B7A9B865AE47
      7895E8D6A42A0717C40BCCC7A735F33B1E3766AB0E4B5D681BAB410734AB62B0

Links & Credits
http://www.sighax.com/ ;one signature, and some general info
http://gist.github.com/SciresM/cdd2266efb80175d37eabbe86f9d8c52 ;six signatures

3DS DMA Registers

ARM9 NDMA
3DS DMA - NDMA Registers
ARM9 XDMA and ARM11 CDMA
3DS DMA - Corelink DMA Peripheral IDs
3DS DMA - Corelink DMA Register Summary
3DS DMA - Corelink DMA - Interrupt and Fault Status Registers
3DS DMA - Corelink DMA - Internal State Status Registers
3DS DMA - Corelink DMA - Transfer Start (aka "Debug" Registers)
3DS DMA - Corelink DMA - Fixed Configuration and ID Registers
3DS DMA - Corelink DMA Opcode Summary
The ARM Corelink DMA hardware is documented in

      DDI0424D_dma330_r1p2_trm        - DMA controller (also covers r0p0 and r1p1)
      IHI0022D amba axi_specification - Memory (ARCACHE, ARPROT etc.)

ARM11 GPU DMA
3DS GPU External Registers - Memfill and Memcopy
The GPU does probably also have DMA(s) for reading things like command lists, and texture data, and for rendering to framebuffer.

3DS DMA - NDMA Registers

NDMA (ARM9 only)
10002000h ARM9
Same as DSi, except, there seem to be 8 channels (instead of 4).
DSi New DMA (NDMA)
And with new bit in NDMAGCNT register:

      0        SAD/DAD/TCNT/WCNT register read (0=Written value, 1=Current value)

And with new bits in NDMAxCNT registers:

      0-4      New extra startup mode bits (used if startup=0Fh)
      5-9      Unknown (unused on DSi, seem to be always 0 on 3DS, too)

And with changed startup modes:

      00h      TIMER0                                       (Port 10003000h)
      01h      TIMER1                                       (Port 10003004h)
      02h      TIMER2                                       (Port 10003008h)
      03h      TIMER3                                       (Port 1000300Ch)
      04h      CTRCARD0                                    (maybe 10004000h)
      05h      CTRCARD1                                    (maybe 10005000h)
      06h      SDMMC controller (eMMC and SD/MMC slot)      (Port 10006000h)
      07h      SDxx ?     ... apparently not SDIO wifi?    (maybe 10007000h)
      08h      AES IN (WRFIFO)                              (Port 10009008h)
      09h      AES OUT (RDFIFO)                             (Port 1000900Ch)
      0Ah      SHA IN (WRFIFO)                              (Port 1000A000h)
      0Bh      SHA OUT (RDFIFO) (optional readback)         (Port 1000A000h)
      0Ch      NTRCARD      (used so by bootrom)           (maybe 10164000h)
      0Dh      ?
      0Eh      ?
      0Fh      See below (subclassed)
      10h-1Fh  Start immediately (without repeat)

Mode 0Fh is subclassed by new bits from NDMAxCNT.bit0-4:

      0Fh.00h     exists, related to SPI_CARD and AES IN     ;guess:
      0Fh.01h     exists, related to SPI_CARD and AES IN     ;maybe these also
      0Fh.02h     exists, related to SPI_CARD and AES OUT    ;work with CTRCARD0/1
      0Fh.03h     exists, related to SPI_CARD and AES OUT
      0Fh.04h     exists, related to SPI_CARD and SHA IN
      0Fh.05h     exists, related to SPI_CARD and SHA IN
      0Fh.06h     exists, related to SPI_CARD and SHA OUT
      0Fh.07h     exists, related to SPI_CARD and SHA OUT
      0Fh.08h     SDMMC DATA32 to AES IN  ?    ;used by bootrom
      0Fh.09h     ?   <-- maybe as above for 2nd SDxx controller?
      0Fh.0Ah     exists related to SDMMC and AES OUT
      0Fh.0Bh     ?
      0Fh.0Ch     exists related to SDMMC and SHA IN  ;(SHA at time of SDMMC!)
      0Fh.0Dh     ?
      0Fh.0Eh     exists related to SDMMC and SHA OUT
      0Fh.0Fh     ?
      0Fh.10h     AES OUT to SHA IN       ?    ;used by bootrom
      0Fh.11h     exists related AES IN and SHA OUT
      0Fh.12h-1Fh ?

Obviously still missing is MIC microphone (which should be supported by either NDMA, XDMA, or CDMA) (but maybe needs to be enabled somewhere, maybe selecting ARM/TEAK as target?).
Also nice would be having SDIO-Wifi on ARM9 side somewhere. Old NDS-Wifi might exist somewhere, too?

3DS DMA - Corelink DMA Peripheral IDs

CDMA Peripheral IDs (ARM11)

      00h                   Microphone (requires 1014010Ch.bit0=1)
      01h                   NTRCARD    (requires 1014010Ch.bit1=1)
      02h   camera (cam)    Camera Bus 0 (DSi cameras)     (Port 10120000h)
      03h   camera (cam)    Camera Bus 1 (left-eye camera) (Port 10121000h)
      04h   nwm             maybe wifi controller?
      05h   nwm             maybe debug wifi?
      06h   camera (y2r)    Y2R_0 INPUT_Y      ;\      (Port 10302000h)
      07h   camera (y2r)    Y2R_0 INPUT_U      ;       (Port 10302080h)
      08h   camera (y2r)    Y2R_0 INPUT_V      ; Y2R   (Port 10302100h)
      09h   camera (y2r)    Y2R_0 INPUT_YUV    ;       (Port 10302180h)
      0Ah   camera (y2r)    Y2R_0 OUTPUT_RGBA  ;/      (Port 10302200h)
      0Bh   fs              HASH (SHA FIFO IN) ;\SHA   (Port 10101000h)
      0Ch                   HASH (SHA FIFO OUT);/      (Port 10101000h)
      0Dh   TwlBg           LGYFB_0            ;\GBA   (Port 10110000h)
      0Eh   TwlBg           LGYFB_1            ;/NDS   (Port 10111000h)
      0Fh                   SPI_BUS0 (FIFO)    ;\      (Port 10160000h)
      10h                   SPI_BUS1 (FIFO)    ; SPIs  (Port 10142000h)
      11h                   SPI_BUS2 (FIFO)    ;/      (Port 10143000h)
      12h   mvd (y2r2)      Y2R_1 INPUT_Y      ;\    ;\
      13h   mvd (y2r2)      Y2R_1 INPUT_U      ;     ;
      14h   mvd (y2r2)      Y2R_1 INPUT_V      ; Y2R ; new CDMA controller
      15h   mvd (y2r2)      Y2R_1 INPUT_YUV    ;     ; in New3DS only
      16h   mvd (y2r2)      Y2R_1 OUTPUT_RGBA  ;/    ;
      17h   mvd             L2B_0 INPUT        ;\L2B ;
      18h   mvd             L2B_0 OUTPUT       ;/    ;
      19h   mvd             L2B_1 INPUT        ;\L2B ;
      1Ah   mvd             L2B_1 OUTPUT       ;/    ;
      1Bh                                            ;
      1Ch                                            ;
      1Dh                                            ;
      1Eh                                            ;
      1Fh                                            ;/

New3DS can use both Old CDMA and NewDMA, however, the peripheral data requests are sent only to either one (as selected in Port 10140410h).
Apart from peripherals, concerning ROM/RAM memory:
- CDMA can probably access whatever ARM11 memory (maybe whatever or so?)
- CDMA might maybe use Virtual memory addresses instead of physical addresses?
XDMA Peripheral IDs (ARM9)

      00h   Process9        "CTRCARD"(CARD0?) or SPI_CARD (FIFO) (Port 1000D000h)
      01h                   ?  (maybe CARD1?) or SPI_CARD (FIFO) (Port 1000D000h)
      02h                   ?
      03h                   ?
      04h                   AES IN (WRFIFO)                      (Port 10009008h)
      05h                   AES OUT (RDFIFO)                     (Port 1000900Ch)
      06h   unused???       SHA FIFO IN                          (Port 1000A000h)
      07h   Process9        SHA FIFO OUT (optional readback)     (Port 1000A000h)

Apart from peripherals, concerning ROM/RAM memory:
- XDMA can access ARM9 memory (probably Main RAM, and AXI, and maybe others?)
- XDMA reportedly cannot access the ARM9 bootrom at all

3DS DMA - Corelink DMA Register Summary

Corelink DMA Engines

      1000C000h ARM9  XDMA CoreLink DMA-330 r0p0 (four channels)
      10200000h ARM11 CDMA CoreLink DMA-330 r0p0 (eight channels)
      10206000h ARM11 CDMA CoreLink DMA-330 r1p1 (eight channels) (New3DS only)
      10300000h ARM11 DMA region (aka FIFOs are here?)

The New3DS has two DMA controllers on ARM11 side (the r0p0 is used by bootrom, and, after bootrom, everything is usually done by r1p1).
DMAC Control Registers

      10xxx000h       DSR           DMA Manager Status Register (R)
      10xxx004h       DPC           DMA Manager Program Counter (R)
      10xxx008h-01Ch  -             Reserved
      10xxx020h       INTEN         Interrupt Enable Register (R/W)
      10xxx024h       INT_EVENT_RIS Event-Interrupt Raw Status Register (R)
      10xxx028h       INTMIS        Interrupt Status Register (R)
      10xxx02Ch       INTCLR        Interrupt Clear Register (W)
      10xxx030h       FSRD          DMA Manager Fault Status Register (R)
      10xxx034h       FSRC          DMA Channel(s) Fault Status Register (R)
      10xxx038h       FTRD          DMA Manager Fault Type Register (R)
      10xxx03Ch       -             Reserved
      10xxx040h+n*4   FTRn          DMA channel n Fault type (R)
      10xxx060h-0FCh  -             Reserved

DMAC Channel Thread Status Registers

      10xxx100h+n*8   CSRn          DMA channel n Channel status (R)
      10xxx104h+n*8   CPCn          DMA channel n Channel PC (R)
      10xxx140h-3FCh  -             Reserved

DMAC AXI Status and Loop Counter Registers

      10xxx400h+n*20h SARn          DMA channel n Source address (R)
      10xxx404h+n*20h DARn          DMA channel n Destination address (R)
      10xxx408h+n*20h CCRn          DMA channel n Channel control (R)
      10xxx40Ch+n*20h LC0_n         DMA channel n Loop counter 0 (R)
      10xxx410h+n*20h LC1_n         DMA channel n Loop counter 1 (R)
      10xxx414h+n*20h -             Reserved
      10xxx418h+n*20h -             Reserved
      10xxx41Ch+n*20h -             Reserved
      10xxx500h-CFCh  -             Reserved

DMAC Debug Registers (debugging is meant to be synonym for "start execution")

      10xxxD00h       DBGSTATUS     Debug Status Register (R)
      10xxxD04h       DBGCMD        Debug Command Register (W) (start INST code)
      10xxxD08h       DBGINST0      Debug Instruction-0 (W) (code[2]+ch+thread)
      10xxxD0Ch       DBGINST1      Debug Instruction-1 (W) (byte[4])
      10xxxD10h-DFCh  -             Reserved

DMAC Configuration Registers

      10xxxE00h       CR0           Config Register 0, Misc Info (R)
      10xxxE04h       CR1           Config Register 1, Cache Info (R)
      10xxxE08h       CR2           Config Register 2, Boot Address (R)
      10xxxE0Ch       CR3           Config Register 3, Boot Event/Irq Security (R)
      10xxxE10h       CR4           Config Register 4, Boot Peripheral Security (R)
      10xxxE14h       CRD           DMA Configuration Register (R)
      10xxxE18h-E7Ch  -             Reserved
      10xxxE80h       WD            Watchdog Register (R/W) (rev1 only)
      10xxxE84h-FDCh  -             Reserved

Peripheral and component identification register

      10xxxFE0h-FECh  periph_id_n   Peripheral Identification Registers 0-3 (R)
      10xxxFF0h-FFCh  pcell_id_n    Component Identification Registers 0-3 (R)

CR0 values on 3DS

      [1000CE00h]=000167035h  ;ARM9         (12 events, 8 peripherals, 4 channels)
      [10200E00h]=0001f1075h  ;Old3DS/ARM11 (16 events, 18 peripherals, 8 channels)
      [10206E00h]=0003ff075h  ;New3DS/ARM11 (32 events, 32 peripherals, 8 channels)

3DS DMA - Corelink DMA - Interrupt and Fault Status Registers

     ___________________________ DMAC Control Registers ___________________________

10xxx000h - DSR - DMA Manager Status Register (R)

      0-3   DMA Manager State (see below)
      4-8   DMA Manager DMA_WFE opcode (wait for event) (0..31 = Event 0..31)
      9     DMA Manager Non-Secure state (0=Secure, 1=Non-secure)
      10-31 Unused (undef)

DMA Manager States:

      00h     = Stopped
      01h     = Executing
      02h     = Cache Miss
      03h     = Updating PC
      04h     = Wait for event (WFE, see bit4-8 for event number)
      05h-0Eh = Reserved
      0Fh     = Faulting

10xxx004h - DPC - DMA Manager Program Counter (R)

      0-31  DMA Manager Program Counter

10xxx020h - INTEN - Interrupt Enable Register (R/W)

      0-31  Mode for DMA_SEV opcode event 0-31 "event_irq_select for event 0..31"

Bit [N] = 0 If the DMAC executes DMASEV for the event-interrupt resource N then the DMAC signals event N to all of the threads. Set bit [N] to 0 if your system design does not use irq[N] to signal an interrupt request.
Bit [N] = 1 If the DMAC executes DMASEV for the event-interrupt resource N then the DMAC sets irq[N] HIGH. Set bit [N] to 1 if your system design requires irq[N] to signal an interrupt request.
Note: See DMASEV on page 4-14 for information about selecting an event number.
10xxx024h - INT_EVENT_RIS - Event-Interrupt Raw Status Register (R)
10xxx028h - INTMIS - Interrupt Status Register (R)

      0-31  Event/Interrupt 0-31 Active (0=Inactive/Low, 1=Active/High)

10xxx02Ch - INTCLR - Interrupt Clear Register (W)

      0-31  Interrupt 0-31 (0=No change, 1=Clear Interrupt)

10xxx030h - FSRD - DMA Manager Fault Status Register (R)

      0     DMA Manager Thread in Faulting state (0=No, 1=Fault)
      1-31  Unused (undef)

10xxx034h - FSRC - DMA Channel(s) Fault Status Register (R)

      0-7   Fault Status for channel 0-7 (0=No, 1=Fault)
      8-31  Unused (undef)

10xxx038h - FTRD - DMA Manager Fault Type Register (R)

      0     Undefined Instruction                                   (0=No, 1=Fault)
      1     Invalid Instruction Operand                             (0=No, 1=Fault)
      2-3   Unused (undef)
      4     DMA_GO with inappropriate security permissions          (0=No, 1=Fault)
      5     DMA_WFE or DMA_SEC with inappropriate security          (0=No, 1=Fault)
      6-15  Unused (undef)
      16    AXI Response on RRESP bus              (0=OKAY, 1=EXOKAY/SLVERR/DECERR)
      17-29 Unused (undef)
      30    DMA Abort program-counter location (0=System memory, 1=Debug interface)
      31    Unused (undef)

10xxx040h+n*4 - FTRn - DMA channel n Fault type (R)

      0     Undefined Instruction                                   (0=No, 1=Fault)
      1     Invalid Instruction Operand                             (0=No, 1=Fault)
      2-4   Unused (undef)
      5     DMA_WFE or DMA_SEC with inappropriate security          (0=No, 1=Fault)
      6     Non-secure tried DMAWFP,DMALDP,DMASTP,DMAFLUSHP         (0=No, 1=Fault)
      7     Non-secure channel tried to change CCR                  (0=No, 1=Fault)
      8-11  Unused (undef)
      12    MFIFO too small for DMALD/DMAST                         (0=No, 1=Fault)
      13    MFIFO lacks data for DMAST                              (0=No, 1=Fault)
      14-15 Unused (undef)
      16    AXI Response on RRESP bus, opcode      (0=OKAY, 1=EXOKAY/SLVERR/DECERR)
      17    AXI Response on BRESP bus, data.write  (0=OKAY, 1=EXOKAY/SLVERR/DECERR)
      18    AXI Response on RRESP bus, data.read   (0=OKAY, 1=EXOKAY/SLVERR/DECERR)
      19-29 Unused (undef)
      30    DMA Abort program-counter location (0=System memory, 1=Debug interface)
      31    DMA channel locked-up because of insufficient resources (0=No, 1=Fault)

3DS DMA - Corelink DMA - Internal State Status Registers

     ____________________ DMAC Channel Thread Status Registers ____________________

10xxx100h+n*8 - CSRn - DMA channel n Channel status (R)

      0-3   Channel Status   (see below)
      4-8   Wakeup number    (0-31, channel is waiting for event/peripheral 0-31)
      9-13  Unused (undef)
      14    DMAWFP executed with single/burst operand set     (0=Single, 1=Burst)
      15    DMAWFP executed with/without periph operand set   (0=Without, 1=With)
      16-20 Unused (undef)
      21    Channel operates in Non-Secure state         (0=Secure, 1=Non-secure)
      22-31 Unused (undef)

Channel Status:

      00h     = Stopped
      01h     = Executing
      02h     = Cache miss
      03h     = Updating PC
      04h     = Waiting for event
      05h     = At barrier
      06h     = reserved
      07h     = Waiting for peripheral
      08h     = Killing
      09h     = Completing
      0Ah-0Dh = reserved
      0Eh     = Faulting completing
      0Fh     = Faulting

10xxx104h+n*8 - CPCn - DMA channel n Channel PC (R)

      0-31  DMA Channel's Program Counter

     _________________ DMAC AXI Status and Loop Counter Registers _________________

10xxx400h+n*20h - SARn - DMA channel n Source address (R)
10xxx404h+n*20h - DARn - DMA channel n Destination address (R)

      0-31  DMA Channel's Source/Destination memory address

10xxx408h+n*20h - CCRn - DMA channel n Channel control (R)

      0     Source Burst type      (0=Fixed address, 1=Incrementing address)
      1-3   Source Burst size      (0-4 = 1,2,4,8,16 bytes per beat) (5-7=Reserved)
      4-7   Source Burst len       (0-15 = 1..16 data transfers)
      8     Source ARPROT.bit0 Privileged  (0=Unprivileged, 1=Privileged) ;\access
      9     Source ARPROT.bit1 Non-secure  (0=Secure, 1=Non-secure)       ; type
      10    Source ARPROT.bit2 Instruction (0=Data, 1=Instruction)        ;/
      11-13 Source ARCACHE.bit0-2         ;ARCACHE.bit3 is always low
      14    Dest Burst type (0=Fixed address, 1=Incrementing address)
      15-17 Dest Burst size (0-4 = 1,2,4,8,16 bytes per beat) (5-7=Reserved)
      18-21 Dest Burst len  (0-15 = 1..16 data transfers)
      22    Dest AWPROT.bit0 Privileged    (0=Unprivileged, 1=Privileged) ;\access
      23    Dest AWPROT.bit1 Non-Secure    (0=Secure, 1=Non-secure)       ; type
      24    Dest AWPROT.bit2 Instruction   (0=Data, 1=Instruction)        ;/
      25-27 Dest AWCACHE.bit0,1,3  ;AWCACHE.bit2 is always low
      28-30 Endian swap bytes  (0=Off) (1-4=Within 16,32,64,128 bit) (5-7=Reserved)
      31    Unused (undef)

Bit9,23 should/must be both set, else faults (depending on secure mode, or so).
10xxx40Ch+n*20h - LC0_n - DMA channel n Loop counter 0 (R)
10xxx410h+n*20h - LC1_n - DMA channel n Loop counter 1 (R)

      0-7   Remaining loop count, minus 1   (00h..FFh = Loop 1..256 times)
      8-31  Unused (undef)

3DS DMA - Corelink DMA - Transfer Start (aka "Debug" Registers)

     ____________________________ DMAC Debug Registers ____________________________
             (debugging is meant to be a synonym for "start execution")

10xxxD00h - DBGSTATUS - Debug Status Register (R)

      0     Debug Status  (0=Idle, 1=Busy)    ;aka INST0/INST1 busy?
      1-31  Unused (undef)

10xxxD04h - DBGCMD - Debug Command Register (W) (start INST code)

      0-1   Execution (0=Execute DBGINST, 1..3=Reserved)
      2-31  Unused (0)

10xxxD08h - DBGINST0 - Debug Instruction-0 (W) (code[2]+ch+thread)
10xxxD0Ch - DBGINST1 - Debug Instruction-1 (W) (byte[4])

      0     Debug thread  (0=DMA Manager thread, 1=DMA channel 0..7) ;\
      1-7   Reserved (0)                                             ; usually
      8-10  DMA channel (0..7 for channel 0..7) (when above bit0=1)  ; zero
      11-15 Reserved (0)                                             ;/
      16-23 Instruction Byte 0    ;-usually DMA_GO opcode
      24-31 Instruction Byte 1    ;-usually target_channel for DMA_GO
      32-39 Instruction Byte 2    ;\
      40-47 Instruction Byte 3    ; usually target_address for DMA_GO
      48-55 Instruction Byte 4    ;
      56-63 Instruction Byte 5    ;/

Examples:

      db 00h,00h,DMA_GO,<chn>,<addr32bit>  ;<-- start channel code
      db 01h,<chn>,DMA_KILL,0,0,0,0,0      ;<-- kill channel (eg. after fault/hang)

3DS DMA - Corelink DMA - Fixed Configuration and ID Registers

     ________________________ DMAC Configuration Registers ________________________

10xxxE00h - CR0 - Configuration Register 0 - Misc Info (R)

      0     Peripheral Requests supported         (0=None, 1=Yes, see bit12-16)
      1     boot_from_pc signal state at reset    (0=Was Low, 1=Was High)
      2     boot_manager_ns signal state at reset (0=Was Low, 1=Was High)
      3     Reserved (undef)
      4-6   Number of supported DMA channels      (0..7 = 1..8 channels)
      7-11  Reserved (undef)
      12-16 Number of supported Peripherals       (0..31 = 1..32 peripherals)
      17-21 Number of supported Interrupt outputs (0..31 = 1..32 interrupts)
      22-31 Reserved (undef)

Bit1/2 are probably related to CR2 boot address, excecuting in secure or non-secure state... but it's unspecified if Low/High means on or off.

      CR0 values on 3DS:
      [1000CE00h]=000167035h  ;ARM9         (12 events, 8 peripherals, 4 channels)
      [10200E00h]=0001f1075h  ;Old3DS/ARM11 (16 events, 18 peripherals, 8 channels)
      [10206E00h]=0003ff075h  ;New3DS/ARM11 (32 events, 32 peripherals, 8 channels)

10xxxE04h - CR1 - Configuration Register 1 - Cache Info (R)

      0-2   Size of an i-cache line (2,3,4,5 = 4,8,16,32 bytes) (0,1,6,7=Reserved)
      3     Reserved (undef)
      4-7   Number of i-cache lines (0..15 = 1..16 lines)
      8-31  Reserved (undef)

10xxxE08h - CR2 - Configuration Register 2 - Boot Address (R)

      0-31  Reset entrypoint (for DMA Manager?)

10xxxE0Ch - CR3 - Configuration Register 3 - Boot Event/Irq Security (R)

      0-31  Security state for Event-interrupt 0..31 (0=Secure, 1=Non-secure)

10xxxE10h - CR4 - Configuration Register 4 - Boot Peripheral Security (R)

      0-31  Security state for Peripheral 0..31      (0=Secure, 1=Non-secure)

10xxxE14h - CRD - DMA Configuration Register (R)

      0-2   AXI master Data width (2,3,4 = 32,64,128 bit) (0,1,5,6,7=Reserved)
      3     Reserved (undef)
      4-6   Write capability, max number outstanding transactions (0..7 = 1..8)
      7     Reserved (undef)
      8-11  Write queue depth                             (0..15 = 1..16 lines)
      12-14 Read capability, max number outstanding transactions  (0..7 = 1..8)
      15    Reserved (undef)
      16-19 Read queue depth                              (0..15 = 1..16 lines)
      20-29 Data buffer depth                         (0..3FFh = 1..1024 lines)
      30-31 Reserved (undef)

10xxxE80h - WD - Watchdog Register (R/W) (rev1 only)
Supported on rev1 only (ie. r1p0/r1p1/r1p2, but not r0p0).

      0     Action on Lock-up (0=IRQ and Abort contributing channels, 1=IRQ only)
      1-31  Reserved (undef)

     ______________ Peripheral and component identification register ______________

10xxxFE0h-FECh - periph_id_n - Peripheral Identification Registers 0-3 (R)
This region contains four 32bit registers (30h,13h,x4h,00h). One is supposed to extract the lower 8bit of these 32bit values, and then to merge them into a "conceptual-32bit-value" (00x41330h). And then interprete it as so:

      0-11  Part number            (330h=DMAC)
      12-19 Designer               (41h=ARM)
      20-23 Revision               (0=r0p0, 1=r1p0, 2=r1p1, 3=r1p2)
      24    Integration test logic (0=None, 1=Exists)
      25-31 Reserved (undef)

10xxxFF0h-FFCh - pcell_id_n - Component Identification Registers 0-3 (R)
This region contains four 32bit registers (0Dh,F0h,05h,B1h). One is supposed to extract the lower 8bit of these 32bit values, and then to merge them into a "conceptual-32bit-value" (B105F00Dh). And then interprete it as so:

      0-31  Component ID (B105F00Dh)

3DS DMA - Corelink DMA Opcode Summary

Corelink DMA Opcode Summary

      Opcode             CM Syntax
      00h                CM DMAEND                  ;-done  (finish transfer)
      01h                CM DMAKILL                 ;-abort (unfinished transfer)
      04h                C- DMALD                   ;\
      05h                C- DMALDS           ;\cond ; load from SAR (to dmafifo)
      07h                C- DMALDB           ;/     ;/
      08h                C- DMAST                   ;\
      09h                C- DMASTS           ;\cond ; store to DAR (from dmafifo)
      0Bh                C- DMASTB           ;/     ;/
      0Ch                C- DMASTZ                  ;-store zero to DAR
      12h                C- DMARMB                  ;-read memory barrier
      13h                C- DMAWMB                  ;-write memory barrier
      18h                CM DMANOP                  ;-no operation (align padding)
      20h,len-1          C- DMALP lpc0,len          ;\loop start with loop count
      22h,len-1          C- DMALP lpc1,len          ;/
      25h,periph*8       C- DMALDPS periph   ;\     ;\load and notify peripheral
      27h,periph*8       C- DMALDPB periph   ; cond ;/
      29h,periph*8       C- DMASTPS periph   ;      ;\store and notify peripheral
      2Bh,periph*8       C- DMASTPB periph   ;/     ;/
      2Ch,rel_addr       C- DMALPEND                ;-loop end for DMALPFE
      30h,periph*8       C- DMAWFP periph,single    ;\
      31h,periph*8       C- DMAWFP periph,periph    ; wait for peripheral
      32h,periph*8       C- DMAWFP periph,burst     ;/
      34h,event*8        CM DMASEV event            ;-send event (or interrupt)
      35h,periph*8       C- DMAFLUSHP periph        ;-init peripheral
      36h,event*8+00h    CM DMAWFE event            ;\wait for event (with optional
      36h,event*8+02h    CM DMAWFE event,invalid    ;/  code cache invalidate)
      38h,rel_addr       C- DMALPEND  lpc0          ;\
      39h,rel_addr       C- DMALPENDS lpc0   ;\cond ;
      3Bh,rel_addr       C- DMALPENDB lpc0   ;/     ; loop end for DMALP lpc0/1
      3Ch,rel_addr       C- DMALPEND  lpc1          ;
      3Dh,rel_addr       C- DMALPENDS lpc1   ;\cond ;
      3Fh,rel_addr       C- DMALPENDB lpc1   ;/     ;/
      54h,imm16          C- DMAADDH SAR,imm16       ;\add halfword
      56h,imm16          C- DMAADDH DAR,imm16       ;/  ("positive")
      5Ch,imm16          C- DMAADNH SAR,imm16       ;\add imm16+0FFFF0000h
      5Eh,imm16          C- DMAADNH DAR,imm16       ;/  ("negative", rev1 only)
      A0h,channel,imm32  -M DMAGO channel,imm32     ;\jump/goto entrypoint
      A2h,channel,imm32  -M DMAGO channel,imm32,ns  ;/  (ns=non-secure mode)
      BCh,00h,imm32      C- DMAMOV SAR,imm32        ;\
      BCh,01h,imm32      C- DMAMOV CCR,imm32        ; move to register
      BCh,02h,imm32      C- DMAMOV DAR,imm32        ;/
      imm8               -- DCB imm8                ;\manually defined 'code'
      imm32              -- DCD imm32               ;/
      -  (no opcode)     C- DMALPFE   ;loop forever ;-loop start without loop count

All opcodes and parameters (except imm16/imm32) are 8bit wide. The CM column indicates if the opcode can be used in Channel or Manager threads (or both).
The rel_addr parameters are unsigned offsets (jump target is $-rel_addr).
Nocash Syntax
Allows MOV instead LP, and LOOP instead LPEND, and "ADD reg,+/-imm" instead of "ADDH/ADNH reg,imm".

3DS Config Registers

3DS Config - CONFIG9 Registers
3DS Config - CONFIG11 Registers
3DS Config - AXI Registers
3DS Config - L2C-310 Level 2 Cache Controller (New3DS)
3DS Config - ARM7 Registers (GBA/NDS/DSi Mode)

3DS Config - CONFIG9 Registers

CONFIG9 Registers (ARM9 only)

      Address Width Old3DS  Name                    Used by
      10000000h 1  Yes   CFG9_SYSPROT9              Boot9
      10000001h 1  Yes   CFG9_SYSPROT11             Boot9
      10000002h 1  Yes   CFG9_RST11                 Boot9
      10000004h 4  Yes   CFG9_DEBUGCTL
      10000008h 1  Yes   CFG9_AES                   Boot9, Process9, TwlProcess9
      1000000Ch 2  Yes   CFG9_CARD_CTL              Process9
      10000010h 1  Yes   CFG9_CARD_POWER            Process9
      10000012h 2  Yes   CFG9_CARD_INSERT_DELAY     Boot9, Process9
      10000014h 2  Yes   CFG9_CARD_PWROFF_DELAY     Boot9, Process9
      10000020h 2  Yes   CFG9_SDMMCCTL              Process9
      10000100h 2  Yes   CFG9_UNKNOWN
      10000200h 1  No    CFG9_EXTMEMCNT9 (New3DS)   NewKernel9
      10000FFCh 4  Yes   CFG9_MPCORECFG
      10010000h 4  Yes   CFG9_BOOTENV
      10010010h 1  Yes   CFG9_UNITINFO              Process9
      10010014h 1  Yes   CFG9_TWLUNITINFO           Process9

10000000h - CFG9_SYSPROT9

      0     Disables ARM9 bootrom "(+8000h)" when set to 1, and enables access to
              FCRAM. Cannot be cleared to 0 once set to 1.  Boot9
      1     Disables OTP area when set to 1. Cannot be cleared to 0 once set to 1.
              NewKernel9Loader, Process9
      2-7   Unused (0)

On Old 3DS, NATIVE_FIRM reads CFG9_SYSPROT9 to know whether it has previously initialized the TWL console-unique keys using the OTP data. After setting the TWL console-unique keys, NATIVE_FIRM sets CFG9_SYSPROT9 bit 1 to disable the OTP area. In subsequent FIRM launches prior to the next reset, NATIVE_FIRM will see that the OTP area is disabled, and skip this step.
On New 3DS, the above is instead done by the Kernel9 loader. In addition to using the OTP data for initializing the TWL console-unique keys, the Kernel9 loader will generate the decryption key for NATIVE_FIRM. The final keyslot for NATIVE_FIRM is preserved, so that at a non-reset FIRM launch, the keyslot can be reused, since the OTP would then be inaccessible.
10000001h - CFG9_SYSPROT11

      0     Disables ARM11 bootrom "(+8000h)" when set to 1, and enables access
              to FCRAM. Cannot be cleared to 0 once set to 1.  Boot9
      1-7   Unused (0)

10000002h - CFG9_RST11

      0     Presumably takes ARM11 out of reset. Cannot be set to 1 once it has
              been cleared.
            Reportedly: Bit0 is actually for "write-protecting the bootrom area"
      1-7   Unused (0)

10000004h - CFG9_DEBUGCTL

      0-31  Whatever, debug related (readonly, always zero on retail consoles)

10000008h - CFG9_AES (R/W)

      0-1   Unknown (R/W)
      2-3   AES related? Value 3 written after write to AES_CTL (R/W)
      4-7   Unused (0)

1000000Ch - CFG9_CARD_CTL - Gamecard Controller Select (R/W)

      0-1   Gamecard ROM controller  (0=NTRCARD, 1=?, 2=CTRCARD0, 3=CTRCARD1)
      2-3   Unused (0)
      4     Gamecard SPI_CARD mode   (0=Manual, 1=FIFO)
      5-7   Unused (0)
      8     Gamecard SPI controller  (0=NTRCARD, 1=SPI_CARD)
      9-11  Unused (0)
      12    Unknown...? (R/W)
      13-15 Unused (0)

There are three controllers for ROM cartridge commands:

      xxx0h/xxx1h? NTRCARD  (8-byte commands)  (bit1=0)         (Port 10164000h)
      xxx2h        CTRCARD0 (16-byte commands) (bit1=1, bit0=0) (Port 10004000h)
      xxx3h        CTRCARD1 (16-byte commands) (bit1=1, bit0=1) (Port 10005000h)

And three controllers for SPI-bus cartridge savedata:

      x0x0h/x0x1h  NTRCARD Manual NDS-style    (bit8=0, bit1=0) (Port 10164000h)
      x0x2h/x0x3h  None                        (bit8=0, bit1=1) (N/A)
      x10xh        SPI_CARD in Manual Mode     (bit8=1, bit4=0) (Port 1000D000h)
      x11xh        SPI_CARD in FIFO Mode       (bit8=1, bit4=1) (Port 1000D800h)

The deselected controllers are disconnected from the cartridge bus (and tend to return data=FFh when trying to read from the cartridge).
10000010h - CFG9_CARD_POWER (same as SCFG_MC on DSi) (R/W)

      0     NDS Slot Game Cartridge (0=Inserted, 1=Ejected)               (R)
      1     NDS Slot Unknown/Unused (0)
      2-3   NDS Slot Power State (0=Off, 1=On+Reset, 2=On, 3=RequestOff)  (R/W)
      4-15  Unused (0)

Same as SCFG_MC on DSi (but with the bits for 2nd cartridge slot removed). See DSi specs for cartridge power on/off sequences.
DSi Control Registers (SCFG)
10000012h - CFG9_CARD_INSERT_DELAY (usually 1988h = 100ms) (R/W)
10000014h - CFG9_CARD_PWROFF_DELAY (usually 264Ch = 150ms) (R/W)
Same as 4004012h/4004014h on DSi, see DSi SCFG registers for details.

      0-15  Delay in 400h cycle units (at 67.027964MHz)  ;max FFFFh=ca. 1 second

There are related IRQs on ARM9 and ARM11 side (CGC aka Change Gamecard or so):

      ARM9 IF.bit25, and ARM11 Interrupt 74h   ;at begin of PWROFF delay
      ARM9 IF.bit26, and ARM11 Interrupt 75h   ;at end of INSERT delay

10000020h - CFG9_SDMMCCTL
Controls power? Also controls SD card detect?

      0     SD slot power                                 (1=Unknown?) Process9
      1     eMMC power? NAND init hangs if set            (1=Set?)     Process9
      2-3   Other power supplies?                         (??)         Process9
      4-5   Unused (0)
      6     Unknown, set at cold boot                     (1=Set?)     R/W
      7     Unknown                                       (?)          R/W
      8     ? This bit seems to do nothing.               (?)          Process9
      9     If not set force pulls all SD card lines high (0=Not set?) Process9
      10-15 Unused (0)

This register controls power of multiple ports/controllers and allows to map controller 3 to ARM9 or ARM11. The SD card can be accessed on ARM11 by setting bit8 and clearing bit9.

      0     Controller 1/3 port 0 power (SD card) (0=On, 1=Off)  ;10xxx000h.port0
      1     Controller 1 port 1 power (eMMC)      (0=On, 1=Off)  ;10006000h.port1
      2     Controller 2 port 0 power (WiFi SDIO) (0=On, 1=Off)  ;10122000h.port0
      3     Controller 3 port 1 power? Set at cold boot????      ;?
      4-5   Unused (0)
      6     Wifi port related? Pull up? Set at cold boot
      7         R/W
      8     Controller 3 mapping (0=ARM9 0x10007000, 1=ARM11 0x10100000)
      9     SD card controller select (0=0x10007000/0x10100000, 1=0x10006000)
      10-15 Unused (0)

10000100h - CFG9_UNKNOWN

      0-1   Unknown (R/W)
      2     Unused (0)
      3     Unknown (R/W)
      4-7   Unused (0)
      8-13  Unknown (R/W)
      14-15 Unused (0)

10000200h - New3DS - CFG9_EXTMEMCNT9

      0     New3DS: Extended ARM9 memory at 08100000h..0817FFFFh (0=Off, 1=On)
      1-31  Unused (0)

10000FFCh - CFG9_MPCORECFG (R)
Identical to "PDN_MPCORE_CFG". Uh, what?
Above seems to refer to one of the "CONFIG11" registers.
Perhaps 10140FFCh - 16bit CFG11_SOCINFO, though the ARM9 register is 32bit?
Or maybe one of the CFG11_MPCORE_xxx registers, though those are New3DS only?
Or maybe it does actually refer to ARM11 cp15 coprocessor registers???
Or maybe one of the MPCore registers at 17E0xxxxh?
PROBABLY it's CFG11_SOCINFO (as they are both read-only 0007h on New3DS)!
10010000h - CFG9_BOOTENV

      0-31  Value (0..FFFFFFFFh) (R/W)

This register is used to determine what the previous running FIRM was. Its value is kept following an MCU reboot. Its initial value (on a cold boot) is 0. NATIVE_FIRM sets it to 1 on shutdown/FIRM launch.

      LGY FIRM writes value 3 here when launching a TWL title
      LGY FIRM writes value 7 when launching an AGB title

NATIVE_FIRM will only launch titles if this is not value 0, and will only save the AGB_FIRM savegame to SD if this is value 7.
10010010h - CFG9_UNITINFO (R)
This 8bit register is value zero for retail, non-zero for dev/debug units.
10010014h - CFG9_TWLUNITINFO (R/W)

      0-1   Value (to be copied from CFG9_UNITINFO)
      2-7   Unused (0)

In the console-unique TWL key-init/etc function the ARM9 copies the u8 value from REG_UNITINFO to this register.

3DS Config - CONFIG11 Registers

CONFIG11 Registers (also referred to as "PDN" Registers)

      Address   Width Old3DS  Name                            Used by
      10140000h 1*8   Yes     CFG11_SHAREDWRAM_32K_CODE<0-7>  Boot11,Process9,DSP
      10140008h 1*8   Yes     CFG11_SHAREDWRAM_32K_DATA<0-7>  Boot11,Process9,DSP
      10140100h 2     Yes     ?
      10140102h 2     Yes     ?
      10140104h 1     Yes     CFG11_FIQ_CNT                   Kernel11
      10140105h 1     Yes     ?                               Kernel11
      10140108h 2     Yes     ?  Related to HID_PAD_IRQ (??)  TwlBg
      1014010Ch 2     Yes     CFG11_CDMA_CNT                  TwlBg
      10140140h 4     Yes     CFG11_GPUPROT                   Kernel11
      10140180h 1     Yes     CFG11_WIFICNT                   TwlBg, NWM Services
      101401C0h 4     Yes     CFG11_SPI_CNT                   SPI Services, TwlBg
      10140200h 4     Yes     ?
      10140400h 1     No      ?  Clock related?               NewKernel11
      10140410h 4     No      CFG11_CDMA_PERIPHERALS          NewKernel11
      10140420h 1     No      CFG11_BOOTROM_OVERLAY_CNT       NewKernel11
      10140424h 4     No      CFG11_BOOTROM_OVERLAY_VAL       NewKernel11
      10140428h 4     No      ?
      10140FFCh 2     Yes     CFG11_SOCINFO                   Boot11, Kernel11
      10141000h 2     Yes     CFG11_PDN_CNT          ;???     Kernel11, TwlBg
      10141008h 4     Yes     CFG11_PDN_WAKE_ENABLE           PTM, PDN
      1014100Ch 4     Yes     CFG11_PDN_WAKE_REASON           PTM, TwlBg, PDN
      10141100h 2     Yes     CFG11_TWLMODE_BOOT              TwlProcess9, TwlBg
      10141104h 2     Yes     CFG11_TWLMODE_SLEEP             TwlBg
      10141108h 2     Yes     CFG11_TWLMODE_2  ;IRQ? ;?       TwlBg
      1014110Ah 2     Yes     CFG11_TWLMODE_HID_IRQ           TwlBg
      1014110Ch 1     Yes     CFG11_WIFIUNK                   NWM Services
      10141110h 2     Yes     CFG11_TWLMODE_HID_MODE          TwlBg
      10141112h 2     Yes     CFG11_TWLMODE_HID_SET           TwlBg
      10141114h 2     Yes     CFG11_CODEC_0                   Codec, TwlBg
      10141116h 2     Yes     CFG11_CODEC_1                   Codec, TwlBg
      10141118h 1     Yes     ?                               TwlBg
      10141119h 1     Yes     ?                               TwlBg
      10141120h 1     Yes     ?                               TwlBg
      10141200h 4     Yes     CFG11_GPU_CNT         Boot11, Kernel11, PDN, TwlBg
      10141204h 4     Yes     CFG11_GPU_CNT2        Boot11, Kernel11, TwlBg
      10141208h 1     ?       ? GPU related?        Boot11
      10141210h 2     Yes     CFG11_FCRAM_CNT                 Kernel11, TwlBg
      10141220h 1     Yes     CFG11_CODEC_CNT                 Boot11, TwlBg, PDN
      10141224h 1     Yes     CFG11_CAMERA_CNT                PDN Services
      10141230h 1     Yes     CFG11_DSP_CNT                   Process9, PDN
      10141240h ?     No      unknown (nonzero in New3DS mode) XXX !!!!!!!!!!!!
      10141300h 4     No      CFG11_MPCORE_CLKCNT             NewKernel11
      10141304h 2     No      CFG11_MPCORE_CNT                NewKernel11
      10141310h 1     No      CFG11_MPCORE_BOOTCNT_CPU0       NewKernel11
      10141311h 1     No      CFG11_MPCORE_BOOTCNT_CPU1       NewKernel11
      10141312h 1     No      CFG11_MPCORE_BOOTCNT_CPU2       NewKernel11
      10141313h 1     No      CFG11_MPCORE_BOOTCNT_CPU3       NewKernel11

10140000h+0..7 - CFG11_SHAREDWRAM_32K_CODE --- aka MBK
10140008h+0..7 - CFG11_SHAREDWRAM_32K_DATA --- aka MBK
Used for mapping 32K chunks of shared WRAM for Teak DSP code/data.

      0     Master (0=ARM only, 1=ARM and DSP)
      1     Unused (0)
      2-4   Offset (0..7) (slot 0..7) (LSB of address in 32Kbyte units)
      5-6   Unused (0)
      7     Enable (0=Disable, 1=Enable)

ARM11 and ARM9 can access the memory regardless of bit0 (but trigger data abort if bit7 is cleared, or on missing slot values in bit2-4).

      DSP Code is mapped at 1FF00000h..1FF3FFFFh in ARM memory (256Kbytes)
      DSP Data is mapped at 1FF40000h..1FF7FFFFh in ARM memory (256Kbytes)

10140100h - ??? 1bit? (R/W)
10140102h - ??? 1bit? (R) -- But, cleared in New3DS mode?
Unknown.
10140104h - CFG11_FIQ_CNT

      0-1   FIQ related? (R/W)
      2-3   New3DS only: unknown...?      ;initially set, (R/W) in New3DS mode!
      4-7   Unused (0)

"Writing bit1 to this register disables FIQ interrupts.
This bit is set upon receipt of a FIQ interrupt and when svcUnbindInterrupt is called on the FIQ-abstraction software interrupt for the current core. It is cleared when binding that software interrupt to an event and just before that event is signaled."
Maybe bit0-3 are for CPU0-3 (with above mentioned bit1 being for CPU1)? If the bits are really FIQ related, then they are probably used on debug hardware only.
10140105h - ???

      0-1   Unknown...? (R/W)
      2-3   New3DS only: unknown...?      ;initially set, (R/W) in New3DS mode!
      4-7   Unused (0)

Unknown. Maybe bit0-3 are for CPU0-3?
10140108h - Related to HID_PAD_IRQ (??) TwlBg

      0     Unknown...? (R/W)
      1-15  Unused (0)

1014010Ch - CFG11_CDMA_CNT (R/W)

      0     Enable Microphone DMA             (0=Off, 1=Enable CDMA 00h)      (R/W)
      1     Enable NTRCARD DMA on ARM11 side  (0=Off, 1=Enable CDMA 01h)      (R/W)
      2-3   Unused (0)
      4-5   Unknown...?                                                       (R/W)
      6-15  Unused (0)

10140140h - CFG11_GPUPROT

      0-3   Old FCRAM DMA cutoff size, 0 = no protection
      4-7   New FCRAM DMA cutoff size, 0 = no protection   ;<--New3DS mode only
      8     AXI WRAM protection, 0 = accessible
      9-10  QTM DMA cutoff size                            ;<--New3DS mode only
      11-31 Unused (0)

The New3DS bits are writeable only after enabling New3DS mode.
When this register is set to value 0, the GPU can access the entire FCRAM, AXI WRAM, and on New3DS all QTM-mem. On cold boot this reg is set to 0.
Initialized during kernel boot, and used with SVC 59h which was implemented with v11.3.

      The first 800000h-bytes of Old FCRAM cannot be protected.
      The first 800000h-bytes of New FCRAM are protected if Old FCRAM cutoff<>0
      The first 100000h-bytes of QTM cannot be protected.
      Old FCRAM DMA cutoff protects from 28000000h-(800000h*x) until end of FCRAM
      New FCRAM DMA cutoff protects from 30000000h-(800000h*x) until end of FCRAM
      QTM DMA cutoff       protects from 1F400000h-(100000h*x) until end of QTM

10140180h - CFG11_WIFICNT

      0     Enable wifi subsystem
      1-7   Unused (0)

101401C0h - CFG11_SPI_CNT

      0     SPI_BUS0 Mode (registers at 10160000h)  (0=Manual, 1=Fifo/Autopoll)
      1     SPI_BUS1 Mode (registers at 10142000h)  (0=Manual, 1=Fifo/Autopoll)
      2     SPI_BUS2 Mode (registers at 10143000h)  (0=Manual, 1=Fifo/Autopoll)
      3-31  Unused (0)

The registers for the deselected mode are disconnected from the bus, but they are still working internally (that is, transfer attempts will finish after the expected amount of time, but SPI reads return nothing useful: FFh for Manual reads, and 00h for FIFO/Autopoll reads).
10140200h - ???

      0-31  Unknown (R/W)

Unknown.
10140400h - New3DS - Clock related?

      0-1   Unknown (R/W, even if New3DS didn't enable New3DS mode)
      2-31  Zero

10140410h - New3DS - CFG11_CDMA_PERIPHERALS (R/W)

      0-17  CDMA Peripheral 00h-11h data request target (0=Old CDMA, 1=New CDMA)
      18-31 Zero

10140420h - New3DS - CFG11_BOOTROM_OVERLAY_CNT (R/W)

      0     ARM11 Bootrom Overlay Enable (0=Disable, 1=Enable)
      1-31  Unused (0)

When enabled, opcode/data reads from physical(?) address 00010000h-00010FFFh and FFFF0000h-FFFF0FFFh will return following values:

      ARM11 Opcode reads --> E59FF018h    (opcode LDR PC,[$+20h]
      ARM11 Data reads   --> [10140424h]  (CFG11_BOOTROM_OVERLAY_VAL)

This is intended for redirecting the CPU2/3 reset vectors, however, it does also affect all other exception vectors, including for CPU0/1 (so one should usually disable IRQs while having the overlay enabled).
See CFG11_MPCORE_BOOTCNT_CPU2/3 for details on starting CPU2/3.
10140424h - New3DS - CFG11_BOOTROM_OVERLAY_VAL (R/W)

      0-31  ARM11 Bootrom Overlay Data (aka CPU2/3 entrypoint)

Note: For redirecting to different entrypoints for CPU2/3, one can use opcode EE10nFB0h (mov Rn,p15,0,c0,c0,5) to obtain the current CPU number.
10140428h - New3DS - ??? (R/W)

      0     Unknown (R/W, only in New3DS mode)
      1-31  Unused (0)

Unknown.
10140FFCh - CFG11_SOCINFO (R)

      0     Always 1 (bootrom would do extra GPIO if it were cleared)      (R)
      1     Console Type        (0=Old3DS, 1=New3DS)                       (R)
      2     Max Clock on New3DS (0=536MHz, 1=804MHz) ;unused 0 on Old3DS   (R)
      3-15  Unused (0)

Unknown if there are any New3DS consoles released with bit2=0.
Bit2 is also related to CFG11_MPCORE_CNT bit8?
10141000h - CFG11_PDN_CNT (R or W?)

      0     Request sleep?   (0=No, 1=Enter sleep mode?)                     (W?)
      1-14  Unused (0)
      15    Ready to sleep?  (0=No, 1=GPU halted via CFG11_GPU_CNT.bit16=0)  (R?)

10141008h - CFG11_PDN_WAKE_ENABLE (0=Disable, 1=Enable) (R/W)
1014100Ch - CFG11_PDN_WAKE_REASON (0=No, 1=Yes/Ack) (R/ack)

      0     Unused (0)                   -
      1     HID_PAD_IRQ                  IRQ 5Bh Controller Buttons
      2     Unused (0)                   -
      3     GPIO_DATA0_DATA_IN.bit2=0    IRQ 60h Hinge is Open
      4     GPIO_DATA1_IRQ_ENABLE.bit0   IRQ 64h Headphone connect
      5     Unused (0)                   -
      6     GPIO_DATA1_IRQ_ENABLE.bit1   IRQ 66h ?
      7     Unknown...?                  IRQ ?   ?
      8     Unknown...?                  IRQ ?   ?
      9-15  Unused (0)                   -
      16    Unknown...?                  IRQ ?   ?
      17    GPIO_DATA3_IRQ_ENABLE.bit0   IRQ 68h C-stick
      18    GPIO_DATA3_IRQ_ENABLE.bit1   IRQ 69h IrDA IRQ
      19    GPIO_DATA3_IRQ_ENABLE.bit2   IRQ 6Ah Gyro IRQ
      20    GPIO_DATA3_IRQ_ENABLE.bit3   IRQ 6Bh ?
      21    GPIO_DATA3_IRQ_ENABLE.bit4   IRQ 6Ch ?
      22    GPIO_DATA3_IRQ_ENABLE.bit5   IRQ 6Dh ?
      23    GPIO_DATA3_IRQ_ENABLE.bit6   IRQ 6Eh ?
      24    GPIO_DATA3_IRQ_ENABLE.bit7   IRQ 6Fh ?
      25    GPIO_DATA3_IRQ_ENABLE.bit8   IRQ 70h TSC[67h:2Bh] (Headphone connect)
      26    GPIO_DATA3_IRQ_ENABLE.bit9   IRQ 71h MCU[10h-1Fh]
      27    GPIO_DATA3_IRQ_ENABLE.bit10  IRQ 72h NFC?
      28    GPIO_DATA3_IRQ_ENABLE.bit11  IRQ 73h ?
      29    Unknown...?                  IRQ ?   ? ... triggers always/often?
      30    GPIO_DATA0_DATA_IN.bit1=0    IRQ 63h Touchscreen Pen is down
      31    GPIO_DATA0_DATA_IN.bit2=1    IRQ 62h Hinge is Closed

Note: TSC triggers on headphone connect, ack by reading TSC[67h:2Bh].
The REASON bits are getting set only if enabled in CFG11_PDN_WAKE_ENABLE (and only if the corresponding bits in GPIO_DATA1_IRQ_ENABLE, GPIO_DATA3_IRQ_ENABLE, and HID_PAD_IRQ are also enabled).
The REASON bits can be cleared by writing 1 (unless the request condition is still enabled and true).
Caution: Nonzero REASON bits can cause attempts to switch to New3DS mode (via CFG11_MPCORE_CLKCNT) to hang?
Caution: Above is for New3DS (Old3DS doesn't have NFC and C-stick, and the other bits are probably all completely different and still unknown).
10141100h - CFG11_TWLMODE_BOOT (R/W)

      0-1   Setting from ARM7_CNT (Port 10018000h) (0=3DS, 1=NDS/DSi, 2=GBA)    (R)
      2-14  Unused (0) ?
      15    Enable GBA/NDS/DSi hardware   (can be set ONLY if bit0-1=nonzero) (R/W)

10141104h - CFG11_TWLMODE_SLEEP (R/W)

      0     ARM7 Wakeup                   (0=No change, 1=Wakeup; clear bit1-2) (W)
      1-2   ARM7 Sleep state              (0=Normal/awake, 1-2=?, 3=Sleeping)   (R)
      3-14  Unused? (0)
      15    Enable IRQ upon ARM7 Sleep    (0=Disable, 1=Enable IRQ 59h)       (R/W)

Allows to trigger an IRQ when ARM7 enters lower power sleep mode (via GBA SWI 03h or NDS7/DSi7 SWI 07h). If so, one should forward the ARM7 wakeup condition from CFG11_TWLMODE_HID_IRQ to ARM11 register HID_PAD_IRQ, enter sleep mode on ARM11 side, and (after ARM11 wakeup) wakeup ARM7 via CFG11_TWLMODE_SLEEP.bit0.
10141108h - CFG11_TWLMODE_2 ;IRQ? (R?)

      0-15  Unknown, reportedly "Bitfield", but looks like readonly, returns zero?

1014110Ah - CFG11_TWLMODE_HID_IRQ (R)

      0-9   Button IRQ Enable flags (0=Ignore, 1=Select)
      10-13 Not used
      14    IRQ Enable Flag (0=Disable, 1=Enable)
      15    IRQ Condition   (0=Logical OR, 1=Logical AND)

This is a readonly mirror of the ARM7 Key Interrupt Control register (KEYCNT, GBA/NDS Port 4000132h). The ARM7 uses this as wakeup condition for sleep mode, the ARM11 could forward that value to HID_PAD_IRQ when entering sleep mode, too. In homebrew code, one can also mis-use the register to send data from ARM7 to ARM11.
Note: The NDS does also have a separate KEYCNT register on ARM9, but that isn't forwarded to ARM11 side.
1014110Ch - CFG11_WIFIUNK (always 0, not R/W?)

      0-3   unknown/unspecified
      4     Wifi-related? Set to 1 very early in NWM-module... but isn't R/W... ?
      5-xx  unknown/unspecified

Read-only or write-only, always returns zero?
10141110h - CFG11_TWLMODE_HID_MODE - R/W:0FFFh

      0-11  GBA/NDS Button Mode  (0=Auto/HID_PAD, 1=Manual/CFG11_TWLMODE_HID_SET)
      12    Unknown, if any (not R/W, but reportedly used???) (dev hw maybe?)
      13-15 Unused (0)

Set bits will use the corresponding values from CFG11_TWLMODE_HID_SET instead of allowing the hardware to read it from HID_PAD.
This is set to 0x1FFF (all buttons and the debug key) and CFG11_TWLMODE_HID_SET is set to 0 when the "Close this software and return to HOME Menu?" dialog is shown to prevent the button presses from propagating to the DS/GBA CPU.
10141112h - CFG11_TWLMODE_HID_SET - R/W:0FFFh

      0-11  Buttons   ... unknown, reportedly 0 when NOT pressed ??????????
      12    Unknown, if any (not R/W, but reportedly used???) (dev hw maybe?)
      13-15 Unused (0)

Works the same way as HID_PAD, but the values set here are only replaced in the HID_PAD seen by the NDS/GBA CPUs when the corresponding bits in CFG11_TWLMODE_HID_MODE are set.
10141114h - 2 - R/W:0287h CFG11_CODEC_0
10141116h - 2 - R/W:0387h CFG11_CODEC_1
10141118h - 1 - R/W:01h ?
10141119h - 1 - R/W:01h ?
10141120h - 1 - R:0 ?
Unknown.
10141200h - CFG11_GPU_CNT (R/W)

      0     Enable GPU registers at 10400000h and up (0=DANGER) (vram=snow?)
             "When this is unset VRAM is not accessible and triggers exceptions."
      1     Enable GPU_MEMFILL 0/1                   (0=Disable, 1=Enable)    (R/W)
      2     Enable reading GPU Internal registers?   (0=Hangs, 1=Enable)      (R/W)
      3     Enable reading GPU Internal registers?   (0=Hangs, 1=Enable)      (R/W)
      4     Enable GPU_MEMCOPY                       (0=Disable, 1=Enable)    (R/W)
      5     unknown, DANGER, hangs when cleared?     (0=DANGER, 1=Enable)
      6     Enable LCD Pixel Output                  (0=Off/fade, 1=Enable)   (R/W)
      7-15  Unused (0)
      16    Enable LCD Backlight and GPU/VRAM clock? (0=Off/dark, 1=Enable)   (R/W)
      17-31 Unused (0)

10141204h - CFG11_GPU_CNT2 (W)

      0     Power on GPU? (W)
      1-31  unknown/unspecified (0)

10141208h - CFG11_GPU_..........? (W)

      0     unknown/unspecified (used by bootrom) (W)
      1-7   unknown/unspecified (0)

10141210h - CFG11_FCRAM_CNT (R/W)
Used to apply changes to Port 102010xxh FCRAM Registers (which is needed only when switching to GBA mode; or when using nonstandard FCRAM timings).

      0     Apply FCRAM Config     (0=Prepare, 1=Apply; on 0-to-1 transition) (R/W)
      1     Allow 3DS FCRAM access (0=Disable, 1=Enable)                      (R/W)
      2     Apply Busy flag    (0=Ready, 1=Busy; or bit0-1 aren't set to 01h)   (R)
      3-31  Unused (0)

After toggling bit0 from 0-to-1, one must wait until the apply has finished. Weirdly, the Busy flag cannot be read when bit1=1, however, below are some working apply sequences:

      Write 0h, Write 1h, Wait until Bit2=0, Write 3h ;best, for GBA and 3DS mode
      Write 0h, Write 1h, Wait until Bit2=0           ;good, for GBA mode only
      Write 0h, Write 3h, do ugly hardcoded delay     ;ugly, for GBA and 3DS mode

Note: ARM11 hangs when accessing FCRAM if bit0 or bit1 are zero, or if apply is busy (or if GBA mode is active).
10141220h - CFG11_CODEC_CNT

      0     Unknown...?            (R/W)
      1     turn on/off DSP ... ?  (R/W)
      2-xx  Unused (0)

This (what?) is the only time the ARM11 CODEC module uses any 10141xxxh registers. In one case CODEC module clears bit1 in register 10141114h, in the other case CODEC module sets bit1 in registers 10141114h and 10141116h.
10141224h - CFG11_CAMERA_CNT

      0     Camera Enable (needed for camera I2C bus)  (0=Disable, 1=Enable)
     (1)    Unused (0)      ;<--- reportedly "turn on/off cameras" uh???
      1-31  Unused (0)

10141230h - CFG11_DSP_CNT (R/W)

      0-1   Enable DSP registers at 10203000h (0,1,2=Disable, 3=Enable) (R/W)
      2-7   Unused (0)

Unknown what bit0-1 do exactly, maybe one is reset, and one is stop (they must be BOTH set though, otherwise registers at 10203000h are always zero).
10141240h - New3DS - unknown?

      0     Unknown (R/W)
      1-31  Unused (0) (?)

10141300h - New3DS - CFG11_MPCORE_CLKCNT

      0-2    Desired Mode (0,1,2,3,4,5,6,7) (see below)                   (R/W)
      3-14   Unused (0)
      15     Mode Change IRQ Flag (0=None, 1=IRQ 58h) (write 1 to reset)  (R/ack)
      16-18  Current Mode (0,1,3,5,7) (never 2,4,6) (see below)           (R)
      19-31  Unused (0)

Mode values:

      Mode 0: Old3DS Mode, 268MHz (1x), 128MB FCRAM, no L2C cache
      Mode 1: New3DS Mode, 268MHz (1x), 256MB FCRAM, and L2C cache controller
      Mode 3: New3DS Mode, 536MHz (2x), 256MB FCRAM, and L2C cache controller
      Mode 5: New3DS Mode, 804MHz (3x), 256MB FCRAM, and L2C cache controller
      Mode 2/4/6 are same as Mode 0. Mode 7 is same as Mode 5

Mode changes are applied ONLY once when all ARM11 cores are in Wait for IRQ state (eg. "WFI" opcode). At that point, the IRQ flag in bit15 is set, and IRQ 58h is triggered.
Mode changes (and IRQs) occur ONLY when changing to different modes:

      - Changing between mode 0/1/3/5/7 (because they are different)
      - Changing between mode 5/7 (although they appear to be same)

Mode changes (and IRQs) do NOT occur when:

      - Rewriting the current mode value (because mode is already same)
      - Changing between mode 0/2/4/6 (because they are all same as mode 0)

New3DS mode enables some registers (eg. 10141240h, which are always zero in Old3DS mode), and unlocks some Memory and I/O regions (which trigger data abort in Old3DS mode):

      10130000h (L2B_0, L2B_1, Y2R_1, and MVD registers)
      10206000h (newer CDMA controller)
      17E10000h (L2C cache controller)
      28000000h (Extra FCRAM)

Other New3DS memory isn't automatically enabled (and keeps triggering data abort even in New3DS mode, until explicitely enabling it):

      08100000h (Extended ARM9 RAM, needs enable via CFG9_EXTMEMCNT9.bit0)
      1F000000h (New VRAM aka QTM, needs enable via CFG11_MPCORE_CNT.bit0)

Clock changes affect the ARM11 CPU clock, including the MPCore Timer/Watchdog registers at 17E00600h (if desired, one can change their prescalers to maintain them running at same speed despite of the higher CPU clock).
The 804MHz mode should be used only if CFG11_SOCINFO.bit2 indicates that it is supported.
The IRQ flag in bit15 should be acknowledge before (or alongsides with) writing the desired clock value (needed if it was still set from an older un-acknowledged clock change).
IRQ 58h should be enabled to recover from WFI (or maybe anything like Hblank IRQ might work for that, too). CPSR.I flag does not need to be enabled, WFI does only wait for IRQs (but can recover without executing them). Using the old CP15 Wait-for-IRQ opcode instead of WFI does work, too.
10141304h - New3DS - CFG11_MPCORE_CNT

      0     Enable New VRAM aka QTM at 1F000000h-1F3FFFFFh (0=Off, 1=On)      (R/W)
      1-7   Unused (0)
      8     Unknown... should be set only if CFG11_SOCINFO.bit2=1             (R/W)
      9-xx  Unused (0)

Kernel11 sets this to 101h when bit2 in CFG11_SOCINFO is set otherwise 001h.
10141310h - New3DS - CFG11_MPCORE_BOOTCNT_CPU0 (R)
10141311h - New3DS - CFG11_MPCORE_BOOTCNT_CPU1 (R)

      0-7   Fixed (always 30h, even when executing WFI opcode)                  (R)

These are readonly dummy registers, somewhat indicating that CPU0/1 do exist and that they were already started (of which, CPU0 is actually running code, and CPU1 is initially hanging in a bootrom waitloop; which waits for FIRM code to send software interrupt 01h via Port 17E01F00h, and then jumps to [1FFFFFDCh]).
10141312h - New3DS - CFG11_MPCORE_BOOTCNT_CPU2 (R/W)
10141313h - New3DS - CFG11_MPCORE_BOOTCNT_CPU3 (R/W)

      0     Start/Stop CPU core         (0=Stop upon WFI, 1=Start/Enable)     (R/W)
      1     Must be 1 when starting CPU (0=Hangs when setting bit0, 1=Works)  (R/W)
      2-3   Unused (0)
      4     CPU started                 (0=No, 1=Yes, bit0 is/was set)          (R)
      5     CPU not in WFI state        (0=Executes WFI opcode, 1=Normal)       (R)
      6-7   Unused (0)

Starting CPU2/3 must be done with CFG11_BOOTROM_OVERLAY_CNT/VAL (the default reset vector in ARM11 bootrom doesn't support booting CPU2/3).
Bit0 enables CPU2/3 (and alongsides enables corresponding registers at 17E00900h/17E00A00h).
Bit1 must be set alongsides with bit0 (otherwise the CPU hangs somehow), once when the CPU is started, toggling bit1 won't affect the CPU operation; clearing bit1 is commonly done to notify CPU0 that the CPU has started.
Note: When starting/stopping CPU2/3, one should also notify the hardware about the new state (via Port 17E00008h, SCU CPU Status Register).

3DS Config - AXI Registers

PrimeCell High-Performance AXI Bus Matrix (HPM) (PL301) Revision: r1p2
This is something for configuring interactions between Master Interfaces (MIs) and Slave Interfaces (SIs). The datasheet contains only meaningless blurb in a too-big-too-fail language. Guessing between the lines, Master does probably refer to CPUs and DMA controllers, and Slave might refer to Memory Chips.

      1020F000h-3FCh   Unused (0)                                               (-)
      1020F400h+MI*20h QoS Tidemark for Master MI=00h                         (R/W)
      1020F404h+MI*20h QoS Access Control for Master MI=00h                   (R/W)
      1020F408h+MI*20h AR Channel Arbitration value for MI=00h..NumMI-1       (R/W)
      1020F40Ch+MI*20h AW Channel Arbitration value for MI=00h..NumMI-1       (R/W)
      1020F800h-FBCh   Reserved (0)                                             (-)
      1020FFC0h        PrimeCell Configuration Register 0 NumSI's (07h/0Ah)     (R)
      1020FFC4h        PrimeCell Configuration Register 1 NumMI's (11h/16h)     (R)
      1020FFC8h        PrimeCell Configuration Register 2 Zero    (00h)         (R)
      1020FFCCh        PrimeCell Configuration Register 3 Zero    (00h)         (R)
      1020FFD0h-FDCh   Reserved (0)                                             (-)
      1020FFE0h-FECh   PrimeCell Peripheral Register 0,1,2,3 (01h,13h,x4h,00h)  (R)
      1020FFF0h-FFCh   PrimeCell ID Register 0,1,2,3         (0Dh,F0h,05h,B1h)  (R)

These registers allow to read some fixed settings, and to change a few variable settings (there must be a lot more fixed internal settings assigned at manufacturing time, but one cannot read or change them).
The 3DS seems to support 1020F400h/1020F404h for Master 0 only.
Whilst 1020F408h/1020F40Ch are supported for Master 0 and up.
1020F400h+MI*20h - QoS Tidemark for Master MI=00h (R/W)

      0-6   Max number of outstanding transactions before activating QoS (0..7Fh)
      7-31  Unused (0)

A value of 00h does completely disable QoS (instead of instantly triggering it upon 0 outstanding transactions). QoS is short for Quality of Service (whatever than means).
1020F404h+MI*20h - QoS Access Control for Master MI=00h (R/W)

      0-6   Permit Slave 0-6 to use reserved slots (1=Yes) ;\Old3DS mode
      7-31  Unused (0)                                     ;/
      0-9   Permit Slave 0-9 to use reserved slots (1=Yes) ;\New3DS mode
      10-31 Unused (0)                                     ;/

1020F408h+MI*20h AR Channel Arbitration value for MI=00h..NumMI-1 (R/W)
1020F40Ch+MI*20h AW Channel Arbitration value for MI=00h..NumMI-1 (R/W)
Arbitration for AXI read (AR) and AXI write (AW) address channel signals.
The meaning of these register depends on the chip-configuration. There are three possible modes for each MI (of which, the 3DS uses LRG for MI=00h, and Fixed RR for MI=01h and up).

     Programmable Least Recently Granted (LRG) arbitration (3DS: used for MI=00h)
      Write ii00pp00h   ;set priority for interface                         ;-write
      Write FF0000iih   ;select interface for reading                       ;\read
      Read  0000ppiih   ;read priority for previously selected interface    ;/
     Fixed Round-robin (RR) arbitration scheme (3DS: used for MI=01h..NumMI-1)
      Write xxxxxxxxh   ;ignored (values are fixed)                         ;-write
      Write FF0000ssh   ;select slot for reading                            ;\read
      Read  000000iih   ;read interface for previously selected slot        ;/
     Programmable Round-robin (RR) arbitration scheme (3DS: not used)
      Write ss0000iih   ;set interface for slot                             ;-write
      Write FF0000ssh   ;select slot for reading                            ;\read
      Read  000000iih   ;read interface for previously selected slot        ;/

Whereas, the parameter bits are:

      pp = Priority               (00h..FFh; 00h=Highest, FFh=Lowest)  ;for LRG
      ss = Slot number            (00h..unknown max value)             ;for RR
      ii = Slave interface number (00h..NumSI-1)
      FF = Fixed code for reading (FFh)
      00 = Unused/reserved        (00h)

The following settings exist on New3DS (the fixed values are same for AR+AW):

      Master  Old3DS Mode                        New3DS Mode
      MI=00h  pp pp pp pp pp pp pp -- -- -- --   pp pp pp pp pp pp pp pp pp pp --
      MI=01h  -- 01 02 03 04 05 06 -- -- -- --   -- 01 02 03 04 05 06 07 08 09 --
      MI=02h  01 02 05 06 -- -- -- -- -- -- --   01 02 05 06 08 09 -- -- -- -- --
      MI=03h  01 02 04 05 06 -- -- -- -- -- --   01 02 04 05 06 08 09 -- -- -- --
      MI=04h  01 02 04 -- -- -- -- -- -- -- --   01 02 04 08 -- -- -- -- -- -- --
      MI=05h  01 02 04 -- -- -- -- -- -- -- --   01 02 04 08 -- -- -- -- -- -- --
      MI=06h  01 02 04 -- -- -- -- -- -- -- --   01 02 04 08 -- -- -- -- -- -- --
      MI=07h  01 02 -- -- -- -- -- -- -- -- --   01 02 08 -- -- -- -- -- -- -- --
      MI=08h  01 02 -- -- -- -- -- -- -- -- --   01 02 08 -- -- -- -- -- -- -- --
      MI=09h  01 02 -- -- -- -- -- -- -- -- --   01 02 08 -- -- -- -- -- -- -- --
      MI=0Ah  01 02 05 -- -- -- -- -- -- -- --   01 02 05 08 -- -- -- -- -- -- --
      MI=0Bh  -- -- -- -- -- -- -- -- -- -- --   02 08 -- -- -- -- -- -- -- -- --
      MI=0Ch  -- -- -- -- -- -- -- -- -- -- --   08 02 -- -- -- -- -- -- -- -- --
      MI=0Dh  -- -- -- -- -- -- -- -- -- -- --   01 08 -- -- -- -- -- -- -- -- --
      MI=0Eh  -- -- -- -- -- -- -- -- -- -- --   -- -- -- -- -- -- -- -- -- -- --
      MI=0Fh  -- -- -- -- -- -- -- -- -- -- --   -- -- -- -- -- -- -- -- -- -- --
      MI=10h  -- -- -- -- -- -- -- -- -- -- --   -- -- -- -- -- -- -- -- -- -- --
      MI=11h  -- -- -- -- -- -- -- -- -- -- --   01 08 -- -- -- -- -- -- -- -- --
      MI=12h  -- -- -- -- -- -- -- -- -- -- --   01 08 -- -- -- -- -- -- -- -- --
      MI=13h  -- -- -- -- -- -- -- -- -- -- --   01 08 -- -- -- -- -- -- -- -- --
      MI=14h  -- -- -- -- -- -- -- -- -- -- --   -- 01 02 03 04 05 06 07 08 09 --
      MI=15h  -- -- -- -- -- -- -- -- -- -- --   -- 01 02 03 04 05 06 07 08 09 --

Entries with value "01..09" are fixed (and have same values for AR and AW).
Entries marked "--" are reading as zero (but there seems to be no way to distinguish between SI=00h and SI=None).
The priority values (pp) for MI=00h are ininitally 00h, but can be changed, New3DS has 34 priority values in total (7+7 for AR+AW in Old3DS mode, and another 10+10 for AR+AW in New3DS mode).
1020FFC0h PrimeCell Configuration Register 0 Num SIs (R)
1020FFC4h PrimeCell Configuration Register 1 Num MIs (R)

      0-7   Number of Master/Slave Interfaces (MIs/SIs) (01h..20h)
      8-31  -

The values here change depending on whether running in Old3DS or New3DS mode.

      Old3DS Mode: NumMI=11h, NumSI=07h
      New3DS Mode: NumMI=16h, NumSI=0Ah

1020FFC8h PrimeCell Configuration Register 2 Zero (R)
1020FFCCh PrimeCell Configuration Register 3 Zero (R)

      0-31  Zero

1020FFE0h-FECh - PrimeCell Peripheral Register 0-3 (R)
This region contains four 32bit registers (01h,13h,x4h,00h). One is supposed to extract the lower 8bit of these 32bit values, and then to merge them into a "conceptual-32bit-value" (00x41301h). And then interprete it as so:

      0-11  Part number            (301h=HPM)
      12-19 Designer               (41h=ARM)
      20-23 Revision               (1=r1p0, 2=r1p1, 3=r1p2)
      24-31 Reserved (undef)

This value is fixed=00341301h on New3DS (ie. r1p2, no matter if running in Old3DS or New3DS mode).
The value on actual Old3DS is unknown (although, some consoles are reportedly using r1p0?).
1020FFF0h-FFCh - PrimeCell ID Register 0-3 (R)
This region contains four 32bit registers (0Dh,F0h,05h,B1h). One is supposed to extract the lower 8bit of these 32bit values, and then to merge them into a "conceptual-32bit-value" (B105F00Dh). And then interprete it as so:

      0-31  Component ID (B105F00Dh) (same ID as for Corelink DMA controller)

Guesses on possible Master Interfaces (MIs)
Old3DS = 11h MI's

      1xARM11 (with 2 CPU cores)
      1xCDMA  (with 8 channels)
      1xCSND  (with 32+2 sound+capture channels)
      1xGPU   (internal rendering, external to 2 LCD's, and memcopy/memfill)
      1xDSP
      1xARM9                                ;\
      1xXDMA  (with 4 channels)             ; ARM9
      1xNDMA  (with 8 channels)             ;
      1xDMA   (with 4 channels)             ;/
      1xARM7                                ;\
      1xNDMA  (with 4 channels)             ; ARM7
      1xDMA   (with 4 channels)             ; (can't really share ARM11 bus though)
      1xNDS/GBA GPU (2x 2D and 1x 3D)       ;
      1xNDS/GBA Sound (with 15+2 channels)  ;/

New3DS = 16h MIs (five more than Old3DS)

      0xNewARM11 (but with 2 more CPU cores)
      1xNewCDMA  (with 8 channels)
      1xMVD
      1xLevel 2 Cache Controller

Guesses on possible Slave Interfaces (SIs)
Old3DS = 07h SI's

      FCRAM
      VRAM
      ARM9 RAM
      DSP RAM
      AXI RAM
      BIOS ROM(s)
      I/O Area(s)

New3DS = 0Ah SIs (three more than Old3DS)

      Extended VRAM? aka QTM?
      Extended ARM9 RAM
      Extended FCRAM

Datasheets
Reportedly "CoreLink NIC-301 r1p0" (aka NIC-301 Network Interconnect)

      http://infocenter.arm.com/help/topic/com.arm.doc.ddi0422a/CHDGHIID.html
      DDI0422.pdf

But, the ID values don't match up (at least not on New3DS, it's actually: r1p2)

      DDI0422D_hpm_pl301_r1p2_ts.pdf

3DS Config - L2C-310 Level 2 Cache Controller (New3DS)

L2C-310 r3p3, Level 2 Cache Controller (New3DS only)

      17E10000h     L2C_CACHE_ID             R  410000C9h ;\Cache ID and Cache Type
      17E10004h     L2C_CACHE_TYPE           R  9E440440h ;/
      17E10100h     L2C_CONTROL              RW 00000000h ;\
      17E10104h     L2C_AUX_CONTROL          RW 02090000h ; Control
      17E10108h     L2C_TAG_RAM_CONTROL      RW 00000111h ;
      17E1010Ch     L2C_DATA_RAM_CONTROL     RW 00000221h ;/
      17E10200h     L2C_EV_COUNTER_CTRL      RW 00000000h ;\
      17E10204h     L2C_EV_COUNTER1_CFG      RW 00000000h ; Interrupt and
      17E10208h     L2C_EV_COUNTER0_CFG      RW 00000000h ; Counter Control
      17E1020Ch     L2C_EV_COUNTER1          RW 00000000h ;
      17E10210h     L2C_EV_COUNTER0          RW 00000000h ;
      17E10214h     L2C_INT_MASK             RW 00000000h ;  ;\
      17E10218h     L2C_INT_STATUS_MASKED    R  00000000h ;  ; Interrupts
      17E1021Ch     L2C_INT_STATUS_RAW       R  00000000h ;  ;
      17E10220h     L2C_INT_CLEAR            W  00000000h ;/ ;/
      17E10730h     L2C_CACHE_SYNC           RW 00000000h ;\
      17E10770h     L2C_INV_PA               RW 00000000h ;
      17E1077Ch     L2C_INV_WAY              RW 00000000h ; Cache Maintenance
      17E107B0h     L2C_CLEAN_PA             RW 00000000h ; Operations
      17E107B8h     L2C_CLEAN_INDEX          RW 00000000h ;
      17E107BCh     L2C_CLEAN_WAY            RW 00000000h ;
      17E107F0h     L2C_CLEAN_INV_PA         RW 00000000h ;
      17E107F8h     L2C_CLEAN_INV_INDEX      RW 00000000h ;
      17E107FCh     L2C_CLEAN_INV_WAY        RW 00000000h ;/
      17E10900h+N*8 L2C_D_LOCKDOWN_0..7      RW 00000000h ;\
      17E10904h+N*8 L2C_I_LOCKDOWN_0..7      RW 00000000h ; Cache Lockdown
      17E10950h     L2C_LOCK_LINE_EN         RW 00000000h ;
      17E10954h     L2C_UNLOCK_WAY           RW 00000000h ;/
      17E10C00h     L2C_ADDR_FILTERING_START RW 00000000h ;\Address Filtering
      17E10C04h     L2C_ADDR_FILTERING_END   RW 00000000h ;/
      17E10F40h     L2C_DEBUG_CTRL           RW 00000004h ;\
      17E10F60h     L2C_PREFETCH_CTRL        RW 04000000h ; Debug, Prefetch, Power
      17E10F80h     L2C_POWER_CTRL           RW 00000000h ;/

Caution: L2C registers can be read via LDR only (LDRB/LDRH cause data abort).
Note: Some L2C registers are write-able only with Secure access (S), not with Non-secure access (NS), but that seems to apply only for TrustZone extension (which doesn't seem to exist in 3DS).
Official specs: DDI0246H_l2c310_r3p3_trm.pdf

     _____________________ Cache ID and Cache Type (NS and S) _____________________

17E10000h - L2C_CACHE_ID - Cache ID Register (410000C9h) (R)

      0-5   RTL release               (9=r3p3)
      6-9   Part number               (3=L2C-310)
      10-15 CACHEID pins              (reads as 0 on New3DS)
      16-23 Reserved (0)
      24-31 Implementer               (41h=ARM)

17E10004h - L2C_CACHE_TYPE - Cache Type Register (9E440440h) (R)

      0-1   L2 cache line length      (0=32 bytes)                    ;\
      2-5   Reserved (0)                                              ;
      6     L2 associativity          (from L2C_AUX_CONTROL.bit16)    ; instruction
      7     Reserved (0)                                              ;
      8-10  Isize L2 cache way size   (from L2C_AUX_CONTROL.bit19-17) ;
      11    Reserved (0)                                              ;/
      12-13 L2 cache line length      (0=32 bytes)                    ;\
      14-17 Reserved (0)                                              ;
      18    L2 associativity          (from L2C_AUX_CONTROL.bit16)    ; data
      19    Reserved (0)                                              ;
      20-22 Dsize L2 cache way size   (from L2C_AUX_CONTROL.bit19-17) ;
      23    Reserved (0)                                              ;/
      24    Harvard                   (0=Unified, 1=Harvard)          ;-harvard
      25    Lockdown by Line option   (0=Off, 1=On)                   ;\
      26    Lockdown by Master option (0=Off, 1=On)                   ; ctype
      27-28 Fixed (always 3)                                          ;/
      29-30 Reserved (0)
      31    Data banking              (0=Not implemented, 1=Implemented)

     ______________________ Control (Write S, Read NS and S) ______________________

17E10100h - L2C_CONTROL - Control Register (R/W)

      0     L2 Cache enable           (0=Disable, 1=Enable)
      1-31  Reserved (0)

Caution: The cache seems to contain garbage on power-up. Set L2C_INV_WAY=FFFFh, then wait for L2C_INV_WAY=0 before enabling L2C_CONTROL.
17E10104h - L2C_AUX_CONTROL - Auxiliary Control Register (02090000h) (R/W)

      0     Full Line of Write Zero Enable (0=Disable, 1=Enable)
      1-7   Reserved (0) (actually R/W, but unknown/undocumented)
      8     Reserved (0) (always 0)
      9     Reserved (0) (actually R/W, but unknown/undocumented)
      10    Priority for Strongly Ordered and Device Reads Enable (0=Low, 1=High)
      11    Limit  (0=Device writes can use all slots, 1=Ensure one Memory slot)
      12    Exclusive cache configuration      (0=Disable, 1=Enable)
      13    Shared Attribute Invalidate Enable (0=Disable, 1=Enable if no override)
      14-15 Reserved (0) (actually R/W, but unknown/undocumented)
      16    Associativity               (0=8-way, 1=16-way)
      17-19 Way-size (1=16K, 2=32K, 3=64K, 4=128K, 5=256K, 6=512K, 0/7=Same as 1/6)
      20    Event monitor bus enable    (0=Disable, 1=Enable)
      21    Parity enable               (0=Disable, 1=Enable)
      22    Shared attribute override   (0=No, 1=Ignore Shared Attrubute)
      23-24 Force write allocate (0=Use WA, 1=ForceWA=0, 2=ForceWA=1, 3=Same as 0?)
      25    Cache Replacement Policy    (0=Pseudo-random/LFSR, 1=Round-robin)
      26    Lockdown Register Writes    (0=Secure only, 1=Allow non-secure)
      27    Interrupt MASK/CLEAR Access (0=Secure only, 1=Allow non-secure)
      28    Data Prefetch Enable        (0=Disable, 1=Enable)
      29    Instruction Prefetch Enable (0=Disable, 1=Enable)
      30    Early BRESP Enable          (0=Disable, 1=Enable, Early write response)
      31    Reserved (0) (actually R/W, but unknown/undocumented)

Cache size is reportedly "2MB" on New3DS, which is probably meant to be 2Mbyte, ie. 16 ways of 128Kbyte each, and that shared for both code and data caching?
17E10108h - L2C_TAG_RAM_CONTROL - Tag RAM Latency Control (00000111h) (R/W)
17E1010Ch - L2C_DATA_RAM_CONTROL - Data RAM Latency Control (00000221h) (R/W)

      0-2   RAM setup latency           (0-7 = 1..8 cycles of latency)
      3     Reserved (0)
      4-6   RAM read access latency     (0-7 = 1..8 cycles of latency)
      7     Reserved (0)
      8-10  RAM write access latency    (0-7 = 1..8 cycles of latency)
      11-31 Reserved (0)

Uh, is that the latency of the Cache Memory (ie. not the external "cached" memory)?

     __________________ Interrupt and Counter Control (NS and S) __________________

17E10200h - L2C_EV_COUNTER_CTRL - Event Counter Control (R/W)

      0     Event Counting Enable       (0=Disable, 1=Enable)    (R/W)
      1     Event Counter 0 Reset       (0=No change, 1=Reset)   (W)
      2     Event Counter 1 Reset       (0=No change, 1=Reset)   (W)
      3-31  Reserved (0)

17E10204h - L2C_EV_COUNTER1_CFG - Event Counter 1 Configuration (R/W)
17E10208h - L2C_EV_COUNTER0_CFG - Event Counter 0 Configuration (R/W)

      0-1   Event counter interrupt generation  (00h-03h, see below)
      2-5   Counter event source                (00h-0Fh, see below)
      6-31  Reserved (0)

Event counter interrupt generation:

      00h Disabled                          ;count, without irq
      01h Enabled: Increment condition      ;count, with irq on any increment
      02h Enabled: Overflow condition       ;count, with irq on overflow
      03h Interrupt generation is disabled  ;count, without irq (same as 0?)

Counter event source:

      00h  -        Counter Disabled
      01h  CO       Eviction, CastOUT, of a line from the L2 cache
      02h  DRHIT    Data read hit in the L2 cache
      03h  DRREQ    Data read lookup to the L2 cache
      04h  DWHIT    Data write hit in the L2 cache
      05h  DWREQ    Data write lookup to the L2 cache
      06h  DWTREQ   Data write lookup to the L2 cache with Write-Through attribute
      07h  IRHIT    Instruction read hit in the L2 cache
      08h  IRREQ    Instruction read lookup to the L2 cache
      09h  WA       Allocation into the L2 cache caused by a write, with
                      Write-Allocate attribute, miss
      0Ah  IPFALLOC Allocation of a prefetch generated by L2C-310 into the L2 cache
      0Bh  EPFHIT   Prefetch hint hits in the L2 cache
      0Ch  EPFALLOC Prefetch hint allocated into the L2 cache
      0Dh  SRRCVD   Speculative read received by slave port(s)
      0Eh  SRCONF   Speculative read confirmed in slave port(s)
      0Fh  EPFRCVD  Prefetch hint received by slave port(s)
      Note: All REQ lookups will subsequently result in a hit or miss.

17E1020Ch - L2C_EV_COUNTER1 - Event counter 1 value (R/W)
17E10210h - L2C_EV_COUNTER0 - Event counter 0 value (R/W)

      0-31  Counter value, incremented on selected event

If a counter reaches its maximum value, it saturates at that value until it is reset.
17E10214h - L2C_INT_MASK - Interrupt Mask (0=Disable, 1=Enable) (R/W)
17E10218h - L2C_INT_STATUS_MASKED - Masked Interrupt Status Register (R)
17E1021Ch - L2C_INT_STATUS_RAW - Raw Interrupt Status (1=IRQ) (R)
17E10220h - L2C_INT_CLEAR - Interrupt Clear (0=No change, 1=Clear) (W)

      0     ECNTR: Event Counter 0 and 1 Overflow/Increment
      1     PARRT: Parity Error on L2 tag RAM, Read
      2     PARRD: Parity Error on L2 data RAM, Read
      3     ERRWT: Error on L2 tag RAM, Write
      4     ERRWD: Error on L2 data RAM, Write
      5     ERRRT: Error on L2 tag RAM, Read
      6     ERRRD: Error on L2 data RAM, Read
      7     SLVERR: SLVERR from L3
      8     DECERR: DECERR from L3
      9-31  Reserved (0)

Note: STATUS_MASKED is same as STATUS_RAW, but ANDed with MASK.
The IRQ triggers interrupt 76h.

     ________________________ Cache Maintenance Operations ________________________

17E10730h - L2C_CACHE_SYNC - Cache Maintenance Operations (R and W)

      0     C, When writing: Must be 0 (trigger cache sync...?)
      0     C, When reading: Background/Way operation is in progress (0=No, 1=Yes)
      1-31  Reserved (0)

17E10770h - L2C_INV_PA - Invalidate by Physical Address (R/W)
17E107B0h - L2C_CLEAN_PA - Clean by Physical Address (R/W)
17E107F0h - L2C_CLEAN_INV_PA - Clean+Invalidate by Physical Address (R/W)

      0     C (uh, is that same meaning as in L2C_CACHE_SYNC.bit0?)   (R?)
      1-4   Reserved (0)
      5-xx  Index                                                     (W?)
      xx-31 Tag                                                       (W?)

17E1077Ch - L2C_INV_WAY - Invalidate by Way (R/W)
17E107BCh - L2C_CLEAN_WAY - Clean by Way (R/W)
17E107FCh - L2C_CLEAN_INV_WAY - Clean+Invalidate by Way (R/W)

      0-15  Way bits (for way 0..15) (1=Trigger/busy?)                (R/W)
      16-31 Reserved (0)

17E107B8h - L2C_CLEAN_INDEX - Clean by Index (R/W)
17E107F8h - L2C_CLEAN_INV_INDEX - Clean+Invalidate by Index (R/W)

      0     C (uh, is that same meaning as in L2C_CACHE_SYNC.bit0?)   (R?)
      1-4   Reserved (0)
      5-xx  Index                                                     (W?)
      xx-xx Reserved (0)
      28-31 Way number (0..15)                                        (W?)

     _______________________________ Cache Lockdown _______________________________

17E10900h+N*8 - L2C_D_LOCKDOWN_0..7 - Data Cache lockdown 0-7 (R/W)
17E10904h+N*8 - L2C_I_LOCKDOWN_0..7 - Instruction Cache lockdown 0-7 (R/W)

      0-15  DATALOCK/INSTRLOCK 000..111  (use when AyUSERSx[7:5]=000b..111b) ;way?
      16-31 Reserved (0)

17E10950h - L2C_LOCK_LINE_EN - Lockdown by Line Enable (R/W)

      0     Lockdown by Line Enable (0=Disable, 1=Enable)
      1-31  Reserved (0)

17E10954h - L2C_UNLOCK_WAY - Unlock all Lines by Way (R/W)

      0-15  Unlock all Lines by Way operation (0=No/off, 1=Unlock/Busy) ;way0-15
      16-31 Reserved (0)

Caution: When busy, all other L2C registers are becoming readonly (so after writing, one MUST wait until above busy flags go off).

     _________________ Address Filtering (Write S, Read NS and S) _________________

17E10C00h - L2C_ADDR_FILTERING_START - Address filtering Start (R/W)
17E10C04h - L2C_ADDR_FILTERING_END - Address filtering End (R/W)
Not implemented, always zero in New3DS. Allows to redirect a whole address range to master 1 (when two masters are implemented).

      0     Address Filtering Enable (0=Disable, 1=Enable)  ;<-- in Start register
      0     Reserved (0)                                    ;<-- in End register
      1-19  Reserved (0)
      20-31 Address Filtering Start/End Address bit31-20

     _____________ Debug, Prefetch and Power (Write S, Read NS and S) _____________

17E10F40h - L2C_DEBUG_CTRL - Debug Register (00000004h) (R/W)

      0     Disable cache linefill (0=Enable, 1=Disable cache linefills)      (R/W)
      1     Disable write-back     (0=Write-back, 1=Force Write-through)      (R/W)
      2     Secure Privileged Non-Invasive Debug Enable SPNIDEN option (1=on?)  (R)
      3-31  Reserved (0)

17E10F60h - L2C_PREFETCH_CTRL - Prefetch Control Register (04000000h) (R/W)

      0-4   Prefetch Offset (must be 0-7, 15, 23, or 31) (other=Unsupported)
      5-20  Reserved (0) (always 0)
      21    Not same AXI ID on exclusive sequence enable   (0=Same ID, 1=Not same)
      22    Reserved (0) (actually R/W, but unknown/undocumented)
      23    Incr Double Linefill enable (allow 8x64bit)    (0=Disable, 1=Allow)
      24    Prefetch drop, Discard prefetch reads to L3    (0=Disable, 1=Enable)
      25    Reserved (0) (actually R/W, but unknown/undocumented)
      26    Speculative Read Synthesis Option (read-only)  (0=On, 1=Off)        (R)
      27    Double linefill on WRAP read disable           (0=Enable, 1=Disable)
      28    Data prefetch enable                           (0=Disable, 1=Enable)
      29    Instruction prefetch enable                    (0=Disable, 1=Enable)
      30    Double Linefill, Read bursts to L3 on L2 miss  (0=4x64bit, 1=8x64bit)
      31    Reserved (0) (actually R/W, but unknown/undocumented)

17E10F80h - L2C_POWER_CTRL - Power Control Register (R/W)

      0     Standby mode enable         (0=Disable, 1=Enable)
      1     Dynamic clock gating enable (0=Disable, 1=Enable)
      2     Reserved (0) (actually R/W, but unknown/undocumented)
      3-31  Reserved (0) (always 0)

3DS Config - ARM7 Registers (GBA/NDS/DSi Mode)

The somewhat misnamed "ARM7" registers are actually ARM9 registers, used to configure GBA/NDS/DSi mode.

      10018000h 1   ARM7_CNT                ;\GBA/NDS/DSi mode
      10018080h 20h ARM7_BOOTCODE           ;/
      10018100h 2   ARM7_SAVE_TYPE          ;\GBA savedata
      10018104h 2   ARM7_SAVE_CNT           ;/
      10018108h 2   ARM7_RTC_CNT            ;\
      10018110h 4   ARM7_RTC_BCD_DATE       ;
      10018114h 4   ARM7_RTC_BCD_TIME       ; GBA real time clock
      10018118h 4   ARM7_RTC_HEX_TIME       ;
      1001811Ch 4   ARM7_RTC_HEX_DATE       ;/
      10018120h 4   ARM7_SAVE_CFG_?         ;\
      10018124h 4   ARM7_SAVE_CFG_?         ; GBA savedata timings?
      10018128h 4   ARM7_SAVE_CFG_?         ;
      1001812Ch 4   ARM7_SAVE_CFG_?         ;/
      04700000h 4   <-- on ARM7 side, disable bootcode overlay

For specs on GBA/NDS/DSi mode:
GBA Reference
NDS Reference
DSi Reference
The ARM7_RTC_xxx registers are emulating the GBA cartridge RTC. The RTC for NDS/DSi mode is emulated separately via registers in the 3DS GPIO register space:
3DS GPIO Registers
The GBA/NDS/DSi video must be forwarded to 3DS framebuffers via ARM11 DMA:
3DS Video LGY Registers (Legacy GBA/NDS Video to Framebuffer)
GBA Audio requires enabling amplifiers via TSC register, and enabling GBA sound via CODEC_SNDEXCNT.
NDS/DSi sound probably requires something similar, and more extensive TSC initialization for NDS or DSi touchscreen mode; and adjusting the TSC calibration points depending on whether using LGYFB scaling.
10018000h - ARM7_CNT (R/W)

      0-1   Console Mode (0=3DS, 1=NDS/DSi, 2=GBA, 3=Auto-replaced by 0)      (R/W)
      2-31  Unused (0)

After writing ARM7_CNT, apply the mode value by writing [10141100h].bit15=1 (CFG11_TWLMODE_BOOT). GBA/NDS/DSi mode will start ARM7, executing the ARM7_BOOTCODE.
NDS/DSi mode changes the ARM9 memory map (to survive the changed memory map, ARM9 should execute ITCM code during the mode change). GBA mode does keep ARM9 in 3DS mode. ARM11 is always kept running in 3DS mode.
10018080h..1001809Fh - ARM7_BOOTCODE (32 bytes) (R/W)
These 32 bytes do overlay the exception vectors at 00000000h..0000001Fh in the ARM7 BIOS ROMs (for GBA/NDS/DSi mode). The ARM7 reset vector opcode(s) are executed after switching to GBA/NDS/DSi mode (see ARM7_CNT CFG11_TWLMODE_BOOT.bit15).
After booting, ARM7 can disable the BOOTCODE overlay by writing [4700000h]=1.
ARM7:04700000h - on ARM7 side, disable bootcode overlay (W)

      0     Disable ARM7_BOOTCODE overlay (0=No, 1=Disable) (SET-ONCE)
      1-31  Unused (0)

     ____________________ GBA Mode Cartridge Savedata and RTC ____________________

10018100h - ARM7_SAVE_TYPE (R/W)

      0-3   GBA Cartridge Type (00h-0Fh, see below)                           (R/W)
      4-15  Unused (0)

Type values (same as used in the footer of the GBA ROM-image):

      00h = ROM 16.0Mbyte, EEPROM 0.5Kbyte (in upper 16Mbyte of ROM area)
      01h = ROM 31.9Mbyte, EEPROM 0.5Kbyte (in upper 100h byte of ROM area)
      02h = ROM 16.0Mbyte, EEPROM 8Kbyte   (in upper 16Mbyte of ROM area)
      03h = ROM 31.9Mbyte, EEPROM 8Kbyte   (in upper 100h byte of ROM area)
      04h = ROM 32Mbyte, FLASH 64Kbyte, RTC   ;\(FLASH ID=3D1Fh, Atmel)
      05h = ROM 32Mbyte, FLASH 64Kbyte        ;/
      06h = ROM 32Mbyte, FLASH 64Kbyte, RTC   ;\(FLASH ID=D4BFh, SST)
      07h = ROM 32Mbyte, FLASH 64Kbyte        ;/
      08h = ROM 32Mbyte, FLASH 64Kbyte, RTC   ;\(FLASH ID=1B32h, Panasonic)
      09h = ROM 32Mbyte, FLASH 64Kbyte        ;/
      0Ah = ROM 32Mbyte, FLASH 128Kbyte, RTC  ;\(FLASH ID=09C2h, Macronix)
      0Bh = ROM 32Mbyte, FLASH 128Kbyte       ;/
      0Ch = ROM 32Mbyte, FLASH 128Kbyte, RTC  ;\(FLASH ID=1362h, Sanyo)
      0Dh = ROM 32Mbyte, FLASH 128Kbyte       ;/
      0Eh = ROM 32Mbyte, SRAM 32Kbyte         ;-SRAM
      0Fh = ROM 32Mbyte                       ;-Raw ROM

10018104h - ARM7_SAVE_CNT (R/W)

      0     Savedata mapping (0=GBA:0E000000h, 1=3DS:08080000h)               (R/W)
      1-15  Unused (0)

10018108h - ARM7_RTC_CNT (W and R)

      0     Write   (0=No change, 1=Apply RTC_HEX)                              (W)
      1     Read    (0=No change, 1=Latch RTC_BCD and RTC_HEX)                  (W)
      2-13  Unused (0)
      14    Write Error Flag      (0=Okay, 1=Error, invalid data)               (R)
      15    Write/Read Busy Flag  (0=Ready, 1=Busy)                             (R)

To get the current time:

      Set Read flag, wait until busy=0, then read RTC_HEX or RTC_BCD registers

To set the current time:

      Write RTC_HEX registers, then set Write flag, then wait until busy=0
      (this does also set BCD registers, the hardware auto-converts HEX to BCD)

The initial time on power-up in 01 Jan 2000, 00:00:00. The actual battery backed time can be obtained from MCU[30h..36h].
The GBA software can access the RTC via port 080000C4h, 080000C6h, 080000C8h.
10018110h - ARM7_RTC_BCD_DATE (R)

      0-7   Year  BCD   (00h..99h)
      8-15  Month BCD   (01h..12h)
      16-23 Day   BCD   (01h..31h)
      24-31 Day of Week (00h..06h) (WHAT=Monday?)

10018114h - ARM7_RTC_BCD_TIME (R)

      0-7   Hour    BCD (00h..23h) (always 24-hours, even in AM/PM mode)
      8-15  Minute  BCD (00h..59h)
      16-23 Second  BCD (00h..59h)
      24-31 Zero        (00h)

10018118h - ARM7_RTC_HEX_TIME (R=Latched Read value, W=Written value)

      0-6   Second      (signed -40h..+3Fh, usually 00h..3Bh)
      7     Force Reset (0=Normal, 1=Force 1st Jan 2000, 00:00:00)
      8-14  Minute      (signed -40h..+3Fh, usually 00h..3Bh)
      15    12/24-hour  (0=12 hour, 1=24 hour) (for GBA side, both with AM/PM flag)
      16-21 Hour        (signed -20h..+1Fh, usually 00h..17h)
      22-23 Unused      (0)
      24-27 Day of Week (signed -08h..+07h, usually 00h..06h) (WHAT=Monday?)
      28-30 Unknown     (can be 0..7)
      31    Error       (0=Normal, 1=Triggers error)

1001811Ch - ARM7_RTC_HEX_DATE (R=Latched Read value, W=Written value)

      0-15  Days since 1st Jan 2000 (0000h..8EACh=100 years, Bigger=Triggers error)
      16-31 Unknown                 (can be 0000h..FFFFh)

10018120h - ARM7_SAVE_CFG_? - R/W mask 00FFFFFFh (reset=007FD000h=8376320)
10018124h - ARM7_SAVE_CFG_? - R/W mask 00FFFFFFh (reset=007FD000h=8376320)
10018128h - ARM7_SAVE_CFG_? - R/W mask 000FFFFFh (reset=000000E0h=224)
1001812Ch - ARM7_SAVE_CFG_? - R/W mask 000FFFFFh (reset=00051000h=331776)
Maybe video/color config, or write/erase timings, or so?

      "This is copied from rom footer + 10h."

Uh, but the description of the ROM footer doesn't mention anything at "footer+10h".
Maybe this is the "ghosting" stuff, whatever that is... maybe color bleeding?

     ______________________ Memory Maps in GBA/NDS/DSi Modes ______________________

Memory map in GBA Mode

      3DS       --> GBA
      08080000h --> 0E000000h, GBA Cart FLASH/SRAM/EEPROM (max 128Kbyte)
      080A0000h --> 06000000h, GBA 2D-Engine VRAM (64K+32Kbyte)
      080B8000h --> 03000000h, GBA Fast WRAM (32Kbyte)
      080C0000h --> 02000000h, GBA Slow WRAM (256Kbyte)
      20000000h --> 08000000h, GBA Cart ROM (32Mbyte max)

Cart ROM is unstable: About 99% reads are reading from addr+20h (within 800h-byte pages), and about 1% are randomly reading as wanted from address+0.

      see FCRAM_MODE.bit0 for workaround

When in GBA mode, ARM9 seems to be no longer able to access the remapped ARM9 memory blocks (ARM9 only sees 00h's)? And, ARM9/ARM11 seem to HANG (without any exception) when trying to access Main RAM at 20000000h?
Memory map in NDS/DSi Mode

      3DS       --> NDS/DSi
      08000000h --> 06800000h, NDS VRAM A (128Kbyte)
      08020000h --> 06820000h, NDS VRAM B (128Kbyte)
      08040000h --> 06840000h, NDS VRAM C (128Kbyte)
      08060000h --> 03800000h, NDS ARM7 WRAM (64Kbyte) (ARM7 only)
      08070000h --> 06898000h, NDS VRAM H (32Kbyte)
      08078000h --> 068A0000h, NDS VRAM I (16Kbyte)
      08080000h --> 06860000h, NDS VRAM D (128Kbyte)
      080A0000h --> 06880000h, NDS VRAM E (64Kbyte)
      080B0000h --> 06890000h, NDS VRAM F (16Kbyte)
      080B4000h --> 06894000h, NDS VRAM G (16Kbyte)
      080B8000h --> 03000000h, NDS Shared RAM (32Kbyte) (initially mapped to ARM9)
      080C0000h --> 03xxxxxxh, DSi New Shared WRAM A (256Kbyte) (Misc)
      10174000h --> 04804000h, NDS Wifi RAM (8Kbyte)
      1FF00000h --> 03xxxxxxh, DSi New Shared WRAM B (256Kbyte) (DSP Code)
      1FF40000h --> 03xxxxxxh, DSi New Shared WRAM C (256Kbyte) (DSP Data)
      20000000h --> 02000000h, NDS Main RAM (max 16MByte)     ;\only each 4th
      20000000h --> 0C000000h, DSi Main RAM (max 32Mbyte)     ;/halfword used
      ITCM/DTCM --> ITCM/DTCM, NDS ITCM/DTCM (32K+16K, same mapping as in 3DS mode)
      FF-filled --> 08000000h, GBA Cart ROM/SRAM (32MB+64K) (empty, FFh-filled)

Main RAM needs enable in EXMEMCNT, Main RAM uses only the lower 16bit of the 64bit FCRAM data bus (ie. only each 4th halfword is used). OAM/Palette need enable in POWCNT1. VRAM needs enable in VRAMCNT. New Shared WRAM needs MBK. Wifi RAM needs POWCNT2.
GBA Footers
GBA ROM-images are reportedly stored in .code files (in NCCH .app files, which can also contain the usual NCCH icon/banner/logo).
Nintendo is using 360h-byte footers in GBA ROM-images (at the end of the .code file?).

     Config Data:
      000h 4    Unknown (usually 0) (maybe ROM-image Offset, or version)
      004h 4    ROM-image Size (usually Romsize)
      008h 4    Cartridge Type (Port 10018100h, ARM7_SAVE_TYPE)
      00Ch 4    Unknown (usually 0000FFFFh) (guess: savedata fillvalue?)
      010h 4    Unknown (Port 10018120h, reportedly 1561662 or 2607238) ;\maybe
      014h 4    Unknown (Port 10018124h, reportedly 156166  or 577077 ) ; write
      018h 4    Unknown (Port 10018128h, reportedly 134     or 388    ) ; erase
      01Ch 4    Unknown (Port 1001812Ch, reportedly 187667  or 201072 ) ;/timings?
      020h 4    LCD Ghosting (01h..FFh) (uh, what is that?)
      024h 300h LCD Video LUT (guess: maybe for Port 10400484h/10400584h or so?)
      324h 0Ch  Padding (0)
     1st Descriptor:
      330h 4    Descriptor Type  (00h=ROM-Image)
      334h 4    ROM-image Offset (usually 0)
      338h 4    ROM-image Size   (usually Romsize)
      33Ch 4    Padding (0)
     2nd Descriptor:
      340h 4    Descriptor Type  (01h=Config Data)
      344h 4    Config Offset    (usually Romsize+0)
      348h 4    Config Size      (usually 324h)
      34Ch 4    Padding (0)
     Footer Entrypoint (in last 10h-byte of .code file):
      350h 4    GBA Footer ID          (".CAA")
      354h 4    Maybe Version          (must be 1)
      358h 4    Descriptor List Offset (usually Romsize+330h)
      35Ch 4    Descriptor List Size   (usually 20h) (2*10h)

GBA Savedata
Upon power-off, GBA savedata is usually temporarily stored in a small eMMC partition, and later copied to the actual savedata file upon reboot. The file format and filename for that savedata are unknown...?
ARM7 Registers Misc...
ARM7 has the GBA BIOS implemented in hardware. The BIOS is completely identical to the original GBA BIOS (uh, actually, it is the GBA BIOS version from NDS, which has [3F0Ch]=01h).
The system is booted silently by calling SWI 01h (aka RegisterRamReset), followed by jumping to the code that does SWI 00h (aka SoftReset) to finish booting. The boot splash is still in BIOS, however, and can be seen by calling or replacing one of the previous interrupts with SWI 26h (aka HardReset).
ARM7_BOOTCODE: "This is the first code that will be run after execution begins. TwlProcess9 uses this to put ARM7 in a loop (TWL), and to set the POSTFLG and branch to more copied code (GBA)."

3DS SPI and I2C Bus

     __________________________________ SPI Bus __________________________________

SPI Bus
3DS SPI Registers
SPI Devices
3DS SPI Devices

     __________________________________ I2C Bus __________________________________

I2C Bus
3DS I2C Registers
I2C Device List
3DS I2C Device List
I2C Device Specs...
3DS I2C MCU Register Summary
3DS I2C MCU[00h-01h,05h-07h] - Firmware
3DS I2C MCU[02h-0Fh] - Status
3DS I2C MCU[10h-1Fh] - Interrupt Flags
3DS I2C MCU[20h-24h] - Power Control
3DS I2C MCU[28h-2Eh] - LED Control
3DS I2C MCU[30h-3Fh] - Real-Time Clock (RTC)
3DS I2C MCU[40h-51h] - Accelerometer/Pedometer
3DS I2C MCU[60h-7Fh] - Misc Status
3DS I2C MCU secondary I2C Devices (on MCU bus)
DSi I2C Device 4Ah (BPTWL chip)
3DS I2C Gyroscope (old version)
3DS I2C Gyroscope (new version)
3DS I2C Infrared Receiver/Transmitter (IrDA)
3DS I2C LCD Screen Controllers
3DS I2C New3DS Near-Field Communication (NFC)
3DS I2C New3DS C-Stick and ZL/ZR-Buttons
3DS I2C New3DS 16bit IO Expander (aka QTM)
3DS I2C Other/Unused/Debug Devices

3DS SPI Registers

SPI Registers
There are four SPI buses (most of them can have up to 3 devices attached):

      1000D000h ARM9        SPI_CARD (savedate in game card SPI FLASH memory)
      10160000h ARM9/ARM11  SPI_BUS0 (0=Powerman, 1=Wifi-FLASH, 2=Touchscr/sound)
      10142000h ARM9/ARM11  SPI_BUS1 (0=Touchscr/sound with extra 3ds registers)
      10143000h ARM9/ARM11  SPI_BUS2 (unused)

The separate registers (at the above base addresses) are:

      10xxx000h 2   SPI_MANUAL_CNT    (R/W)  ;\Manual Access
      10xxx002h 1/2 SPI_MANUAL_DATA   (R/W)  ;/
      10xxx800h 4   SPI_FIFO_CNT      (R/W)  ;\
      10xxx804h 4   SPI_FIFO_DONE     (R/W)  ;
      10xxx808h 4   SPI_FIFO_BLKLEN   (R/W)  ; FIFO Access
      10xxx80Ch 4   SPI_FIFO_DATA     (R/W)  ; (and AUTOPOLL for
      10xxx810h 4   SPI_FIFO_STATUS   (R)    ; status reads)
      10xxx814h 4   SPI_AUTOPOLL      (R/W)  ;
      10xxx818h 4   SPI_FIFO_INT_MASK (R/W)  ;
      10xxx81Ch 4   SPI_FIFO_INT_STAT (R/ack);/

Interrupt IDs and DMA/FIFO startup/peripheral IDs are:

      SPI_CARD   ARM9 IF.bit23    Various (ARM9 NDMA and ARM9 XDMA)
      SPI_BUS0   ARM11 IRQ 56h    ARM11 CDMA 0Fh
      SPI_BUS1   ARM11 IRQ 57h    ARM11 CDMA 10h
      SPI_BUS2   ARM11 IRQ 24h    ARM11 CDMA 11h

Config registers

      CFG11_SPI_CNT - mode select for SPI_BUS0,1,2 (Manual or Fifo)
      CFG9_CARD_CTL - mode select for SPI_CARD     (Manual or Fifo or NTRCARD)

3DS Config - CONFIG11 Registers
3DS Config - CONFIG9 Registers

     ___________________________ SPI Manual Access Mode ___________________________

10xxx000h - SPI_MANUAL_CNT
10xxx002h - SPI_MANUAL_DATA
Manual access mode works same as on DSi. Max transfer rate is 8MHz, 1bit mode only, and the manual byte-by-byte transfer adds some software overload to the transfer time.
DS Serial Peripheral Interface Bus (SPI)
One advantage is that the manual mode supports true bi-directional SPI transfers (which aren't really needed because most SPI chips use only one direction at a time, with dummy data in opposite direction).

     ____________________________ SPI FIFO Access Mode ____________________________

10xxx800h - SPI_FIFO_CNT (R/W)

      0-2   Baudrate   (0=512KHz, 1=1MHz, 2=2MHz, 3=4MHz, 4=8MHz, 5..7=16MHz)
      3-5   Unused (0)
      6-7   SPI_BUS0-2: Device Select (0..2, or 3=Hangs/Reads as 2)
            SPI_CARD:   Unused (0)
      8-11  Unused (0)
      12    Bus Mode                (0=1bit, 1=4bit)
      13    Transfer Direction      (0=Read, 1=Write)
      14    Unused (0)
      15    Start Transfer          (0=Idle/Ready, 1=Start/Busy)
      16-31 Unused (0)

CARD: This register seems to have a bug where the lower 8 bits are shifted up by 16 when reading this register. Uh, really?
10xxx804h - SPI_FIFO_DONE (R/W) (or R when busy?)

      0     Chip Select             (0=Not Selected, 1=Selected)
      1-31  Unused (0)

Select occurs automatically (when starting a transfer via SPI_FIFO_CNT). However, deselect must be done manually (by writing 0 to SPI_FIFO_DONE after last data block). This allows to keep the chip selected during multiple transfer blocks (including blocks with different data direction, eg. WriteCmd + ReadData).
10xxx808h - SPI_FIFO_BLKLEN (R/W) (or R when busy?)

      0-20  Transfer length (1..1FFFFFh bytes, 0=?)
      21-31 Unused (0)

10xxx80Ch - SPI_FIFO_DATA (R/W)

      0-31  32bit FIFO for reading/writing data

10xxx810h - SPI_FIFO_STATUS (R)

      0     Whatever FIFO busy... or FIFO full (0=Not full, 1=Full)
      1-31  unknown/unspecified

"At transfer start and every 32 bytes the FIFO becomes busy."
Uh, unknown if this refers to Send FIFO or Receive FIFO. For the latter having a Empty flag would be most useful.
Might be also a generic "data request" flag, rather than a "full/busy" flag?
10xxx814h - SPI_AUTOPOLL (R/W)

      0-7   Command byte (eg. 05h=RDSR, aka FLASH read status)
      8-15  Unused (0)
      16-19 Timeout    (0..10 = 1ms,2ms,4ms,8ms,..,512ms,1024ms, or 11..15=Never)
      20-23 Unused (0)
      24-26 Bit number (0..6=Bit0..6, or 7=Bugged?, always "ready" after 1st poll?)
      27-29 Unused (0)
      30    Bit value  (0=WaitUntilZero, 1=WaitUntilSet)
      31    Start Poll (0=Idle/Ready, 1=Start/Busy)

Autopoll does repeatedly transfer command+reply bytes, until reaching the desired reply bit state (or until reaching timeout). Autopoll uses the device number and baudrate selected in SPI_FIFO_CNT.
10xxx818h - SPI_FIFO_INT_MASK (R/W) (or R when busy?)

      0     Transfer Finished Interrupt Disable  (0=Enable, 1=Disable)
      1     Autopoll Success Interrupt Disable   (0=Enable, 1=Disable)
      2     Autopoll Timeout Interrupt Disable   (0=Enable, 1=Disable)
      3     Unknown (R/W)                        (?)
      4-31  Unused (0)

10xxx81Ch - SPI_FIFO_INT_STAT (R/ack)

      0     Transfer Finished Flag   (0=No, 1=Yes/IRQ) (write 1 to clear)
      1     Autopoll Success Flag    (0=No, 1=Yes/IRQ) (write 1 to clear)
      2     Autopoll Timeout Flag    (0=No, 1=Yes/IRQ) (write 1 to clear)
      3     Unknown (usually 0, but might be something related to INT_MASK.bit3 ?)
      4-31  Unused (0)

Bit0 also fires on each autopoll try? No: it does not fire on autopoll.

3DS SPI Devices

SPI Device List

      Bus0, Device 0      Power Managment Device             ;\
      Bus0, Device 1      Wifi FLASH                         ; same as NDS/DSi
      Bus0, Device 2      DSi Touchscreen/Sound/Microphone   ;/
      Bus1, Device 0      3DS Touchscreen/Sound/Microphone   ;-extra 3ds registers
      Bus1, Device 1,2    Unused
      Bus2, Device 0,1,2  Unused
      Card, Device 0      Cartridge SPI (eg. FLASH savedata) ;-similar as NDS/DSi
      Card, Device 1,2    Don't exist (there are no device-select bits for card)

SPI Bus/Device 0:0 - Power Managment Device
The old power managment SPI registers are mostly for NDS mode:
DS Power Management Device
On 3DS, backlight and power-down are controlled via MCU.
SPI Bus/Device 0:1 - Wifi FLASH
This chip did contain the firmware in NDS consoles. On 3DS it does merely contain some wifi/user settings, mostly for NDS titles.
DS Firmware Serial Flash Memory
DS Firmware Header
DS Firmware Wifi Calibration Data
DS Firmware Wifi Internet Access Points
DS Firmware User Settings
The 3DS does probably additionally store User settings (and maybe also Wifi Acess Point info) in a eMMC file, but unknown where?
SPI Bus/Device 0:2 - DSi Touchscreen/Sound (DSi mode)
This SPI bus is used for accessing the TSC chip in DSi mode.
DSi Touchscreen/Sound Controller
Touchscreen calibration points for NDS/DSi titles are in Wifi FLASH (matched to the current NDS/DSi screen resolution, which can be 256x192pix or fullscreen; selected by holding Start+Select when starting NDS/DSi title).
SPI Bus/Device 1:0 - 3DS Touchscreen/Sound (3DS mode)
This is another SPI bus wired to the TSC chip, this bus can be accessed in 3DS mode only, giving access to the normal DSi registers, plus some additional 3DS registers in TSC page 64h,65h,67h,FBh. These new registers are required for activating sound output, and for reading the Circle Pad.
3DS TSC, Register Summary
Touchscreen calibration points for 3DS titles are stored in HWCAL0/1.dat files, that files do also include calibration data for Circle Pad, and various initial TSC register settings.
Cartridge SPI
Cartridge SPI can be wired to FLASH savedata (or theoretically anything else).
This can use 4bit SPI mode (if the chip is 4bit compatible, and if 4bit related signals are wired up accordingly, and if the specific commands support 4bit transfers).

3DS TSC, Register Summary

Page Selection

      TSC[xxh:00h]=page    ;Page (each TSC SPI bus probably has own page+index?)

Page 00h-01h (DSi Registers)

      TSC[00h:02h]=read    ;DSi Undocumented status (reserved bits)
      TSC[00h:03h]=read    ;DSi Overtemperature OT Flag (reserved bits)
      TSC[00h:0Bh]=87h     ;DSi DAC NDAC Value
      TSC[00h:39h]=66h     ;DSi ADC DC Measurement 1 (reset=00h, ORed with 66h)
      TSC[00h:3Fh]=D4h     ;DSi DAC Data-Path Setup  (reset=D4h, ORed with C0h)
      TSC[00h:40h]=00h     ;DSi DAC Volume Control
      TSC[00h:41h]=FDh     ;DSi DAC Left Volume Control  ;\aka 3DS     ;HWCAL[2E4h]
      TSC[00h:42h]=FDh     ;DSi DAC Right Volume Control ;/ShutterVol0 ;HWCAL[2E4h]
      TSC[00h:51h]=00h/80h ;DSi Microphone Mute/Unmute ;ADC Digital Mic
      TSC[00h:52h]=80h/00h ;DSi Microphone Mute/Unmute ;ADC Digital Volume
      TSC[01h:2Eh]=03h     ;DSi Microphone MIC BIAS
      TSC[01h:2Fh]=2Bh     ;DSi Microphone MIC PGA
      TSC[01h:30h]=40h     ;DSi P-Terminal ADC Channel Fine-Gain Input (reset=40h)
      TSC[01h:31h]=40h     ;DSi M-Terminal ADC Input Selection         (reset=40h)

The 3DS does usually access only the registers mentioned above (but there are many more DSi-style registers in page 00h,01h,03h; see DSi chapter for details).
Page 04h-0Ch (DSi Coefficient RAM)

      TSC[04h:08h-0Dh]=... ;DSi Mic Autogain ;IIR, as DSi (7Fh,E1h,80h,1Fh,7Fh,C1h)
      TSC[05h:08h-3Fh]=... ;3DS FilterMic32  ;IIR+Biquad A,B,C,D,E;HWCAL[364h-39Bh]
      TSC[05h:48h-7Fh]=... ;3DS FilterMic47  ;IIR+Biquad A,B,C,D,E;HWCAL[39Ch-3D3h]
      TSC[08h:0Ch-3Dh]=... ;3DS FilterFreeB  ;Biquad ;\initialized;HWCAL[3DAh-40Bh]
      TSC[08h:4Ch-7Dh]=... ;3DS FilterFreeB' ;Biquad ; for        ;HWCAL[3DAh-40Bh]
      TSC[09h:02h-07h]=... ;3DS FilterFreeA  ;IIR.L  ; non-GBA    ;HWCAL[3D4h-3D9h]
      TSC[09h:08h-0Dh]=... ;3DS FilterFreeA' ;IIR.R  ;/only       ;HWCAL[3D4h-3D9h]
      TSC[0Ah:02h-07h]=... ;3DS FilterFreeA'';IIR?      HP47  ;\  ;HWCAL[3D4h-3D9h]
      TSC[0Ah:0Ch-3Dh]=... ;3DS FilterFreeB'';Biquad?   HP47  ;/  ;HWCAL[3DAh-40Bh]
      TSC[0Bh:02h-1Fh]=... ;3DS FilterHP32   ;Biquad.L A,B,C  ;\  ;HWCAL[2ECh-309h]
      TSC[0Bh:20h-3Dh]=... ;3DS FilterHP47.L ;Biquad.L D,E,F  ;/  ;HWCAL[30Ah-327h]
      TSC[0Bh:42h-5Fh]=... ;3DS FilterHP32'  ;Biquad.R A,B,C  ;\  ;HWCAL[2ECh-309h]
      TSC[0Bh:60h-7Dh]=... ;3DS FilterHP47.R ;Biquad.R D,E,F  ;/  ;HWCAL[30Ah-327h]
      TSC[0Ch:02h-1Fh]=... ;3DS FilterSP32   ;Biquad.L A,B,C  ;\  ;HWCAL[328h-345h]
      TSC[0Ch:20h-3Dh]=... ;3DS FilterSP47   ;Biquad.L D,E,F  ;/  ;HWCAL[346h-363h]
      TSC[0Ch:42h-5Fh]=... ;3DS FilterSP32'  ;Biquad.R A,B,C  ;\  ;HWCAL[328h-345h]
      TSC[0Ch:60h-7Dh]=... ;3DS FilterSP47'  ;Biquad.R D,E,F  ;/  ;HWCAL[346h-363h]

The above coefficient RAM pages exists on DSi, too. However, the DSi is usually initializing only those in page 04h.
Unknown how the 3DS is using the extra coefficients... does it use miniDSP instructions for that?
Unknown what the duplicated entries are for... maybe left/right channels?
Page 64h (3DS Sound/Microphone Config)

      TSC[64h:01h]=01h     ;3DS Software Reset (?)
      TSC[64h:22h]=18h     ;3DS ? (reset=00h, ORed with 18h, later bit2=cleared)
      TSC[64h:25h]=read    ;3DS status, wait for bit3,7
      TSC[64h:26h]=read    ;3DS status, wait for bit3,7
      TSC[64h:2Ch]         ;unused, but nonzero  ;bit0,1=headphone connect status
      TSC[64h:30h]         ;unused, but nonzero
      TSC[64h:31h]=00h/44h ;3DS ? (reset=00h) (GBA:00h, Other:44h)
      TSC[64h:43h]=11h/91h ;3DS set to 11h, later toggles bit=0 then bit7=1
      TSC[64h:44h]         ;unused, but nonzero
      TSC[64h:45h]=20h/30h ;3DS Speaker off (reset=00h, later=20h, 30h=speakerOff)
      TSC[64h:75h]         ;unused, but nonzero
      TSC[64h:76h]=14h/D4h ;3DS Lock Coefficient RAM? (reset=14h, ORed with C0h)
      TSC[64h:77h]=0Ch/00h ;3DS ? (reset=0Ch, later clear bit2,3 after coeff init)
      TSC[64h:78h]=00h     ;3DS ?
      TSC[64h:7Ah]=00h     ;3DS ?
      TSC[64h:7Bh]=ECh     ;3DS ShutterVolume1                   ;HWCAL[2E5h]
      TSC[64h:7Ch]=0Ah     ;3DS ? (reset=0Ah, later clears bit0)

Page 65h (3DS Sound/Microphone Gains)

      TSC[65h:0Ah]=0Ah     ;3DS ?
      TSC[65h:0Bh]=1Ch/3Ch ;3DS ?  ... depends on TSC[00h:02h..03h]   ;HP
      TSC[65h:0Ch]=04h     ;3DS DriverGainHP                     ;HWCAL[2E0h]*8+4
      TSC[65h:11h]=10h/D0h ;3DS ? (reset=00h, ORed with 10h, later ORed with C0h)
      TSC[65h:12h]=06h     ;3DS DriverGainSP    ;\maybe left?    ;HWCAL[2E1h]*4+2
      TSC[65h:13h]=06h     ;3DS DriverGainSP'   ;/      right?   ;HWCAL[2E1h]*4+2
      TSC[65h:16h]=00h     ;3DS AnalogVolumeHP Left  (0..7Eh?)   ;HWCAL[2E2h]
      TSC[65h:17h]=00h     ;3DS AnalogVolumeHP Right (0..7Eh?)   ;HWCAL[2E2h]
      TSC[65h:1Bh]=07h     ;3DS AnalogVolumeSP  ;\maybe left?    ;HWCAL[2E3h]
      TSC[65h:1Ch]=07h     ;3DS AnalogVolumeSP' ;/      right?   ;HWCAL[2E3h]
      TSC[65h:33h]=03h     ;3DS MicrophoneBias                   ;HWCAL[2E6h]
      TSC[65h:41h]=00h+wait;3DS PGA_GAIN (mic)      (bit0-5)     ;HWCAL[2E8h]
      TSC[65h:42h]=02h+wait;3DS QuickCharge (what?) (bit0-1)     ;HWCAL[2E7h]
      TSC[65h:47h,4Bh,4Ch,4Dh,4Eh,52h,53h]  ;unused, but nonzero
      TSC[65h:77h]=94h/95h ;3DS ? (reset=94h, ORed with 01h)
      TSC[65h:78h]         ;unused, but nonzero
      TSC[65h:7Ah]=01h     ;3DS ?

Some here seem to be alike TSC[1:24h]..TSC[1:2Bh]
Page 67h,FBh (3DS Touchscreen/Circle Pad)

      TSC[67h:17h]=43h     ;3DS AnalogSense & Precharge     ;HWCAL[40Fh]+[40Eh]*10h
      TSC[67h:19h]=69h     ;3DS AnalogStabilize & XP Pullup ;HWCAL[40Dh]+[411h]*10h
      TSC[67h:1Bh]=80h     ;3DS AnalogDebounce & YM_Driver  ;HWCAL[410h]+[412h]*80h
      TSC[67h:24h]=98h/18h ;3DS bit7=0=touchscreen.on  ;bit2=1=has new touchdata?
      TSC[67h:25h]=43h/53h ;3DS bit5-2=0100b=touchscreen.on
      TSC[67h:26h]=00h/ECh ;3DS bit7=1=touchscreen.on  ;bit1=1=had old touchdata?
      TSC[67h:27h]=11h     ;3DS AnalogInterval           ;HWCAL[40Ch]+10h
      TSC[67h:2Bh]=read    ;3DS Ack Headphone connect IRQ (always returns 00h)
      TSC[FBh:01h]=read    ;3DS fifo 26x16bit; 5xTSC.x, 5xTSC.y, 8xCPAD.y, 8xCPAD.x

3DS I2C Registers

I2C Registers

      Address   Width Old3DS  Name
      10161000h 1     Yes     I2C_BUS0_DATA     ;\
      10161001h 1     Yes     I2C_BUS0_CNT      ; BUS 0 (old DSi devices)
      10161002h 2     Yes     I2C_BUS0_CNTEX    ;
      10161004h 2     Yes     I2C_BUS0_SCL      ;/
      10144000h 1     Yes     I2C_BUS1_DATA     ;\
      10144001h 1     Yes     I2C_BUS1_CNT      ; BUS 1 (extra 3DS devices)
      10144002h 2     Yes     I2C_BUS1_CNTEX    ;
      10144004h 2     Yes     I2C_BUS1_SCL      ;/
      10148000h 1     Yes     I2C_BUS2_DATA     ;\
      10148001h 1     Yes     I2C_BUS2_CNT      ; BUS 2 (extra 3DS gimmicks)
      10148002h 2     Yes     I2C_BUS2_CNTEX    ;
      10148004h 2     Yes     I2C_BUS2_SCL      ;/

10161000h - I2C_BUS0_DATA
10144000h - I2C_BUS1_DATA
10148000h - I2C_BUS2_DATA
Unknown. Supposedly data.
10161001h - I2C_BUS0_CNT
10144001h - I2C_BUS1_CNT
10148001h - I2C_BUS2_CNT

      0     Stop  (0=No, 1=Stop/last byte)
      1     Start (0=No, 1=Start/first byte)
      2     Pause (0=Transfer Data, 1=Pause after Error, used with/after Stop)
      3     unknown/unspecified
      4     Ack Flag (0=Error, 1=Okay) (For DataRead: W, for DataWrite: R)
      5     Data Direction (0=Write, 1=Read)
      6     Interrupt Enable (0=Disable, 1=Enable)
      7     Start/busy (0=Ready, 1=Start/busy)

10161002h - I2C_BUS0_CNTEX
10144002h - I2C_BUS1_CNTEX
10148002h - I2C_BUS2_CNTEX

      0     Current SCL pin state (0=Low, 1=High/idle)                       (R)
      1     Wait if SCL held low  (0=No/fixed delay, 1=Yes, wait if SCL=low) (R/W)
      3-14  Unused (0)
      15    Unknown (BUS0: can be set, alongsides bit1 becomes read-only?)   (?)

Bit1=0 appends a short fixed delay after each byte. Bit1=1 will automatically wait if the SCL clock pin is held low: If the peripheral doesn't do that then it can be even slightly faster than the fixed delay, if the peripheral does hold SCL low then the 3DS will wait as long as needed (eg. required for 3DS/New3DS MCU and New3DS C-Stick).
10161004h - I2C_BUS0_SCL
10144004h - I2C_BUS1_SCL
10148004h - I2C_BUS2_SCL

      0-5   Duration for SCL=Low   (0..3Fh, 0=Fastest)  ;default=0
      6-7   Unused (0)
      8-12  Duration for SCL=High  (0..1Fh, 0=Fastest)  ;default=5
      13-15 Unused (0)

The fastest setting (0000h) is about 380kHz (about 41Kbyte/s).
The slowest setting (1F3Fh) is about 84kHz (about 9Kbyte/s)
Hmmm, or maybe the raw bitrate is faster, but with short pause between bytes?

3DS I2C Device List

I2C Devices

      id  bus:dev  service      Device description
      0   0:4Ah    "i2c::MCU"   BPTWL (aka MCU registers for DSi mode)  ;\same
      1   0:7Ah    "i2c::CAM"   Camera0 (internal camera, self-facing)  ; as DSi
      2   0:78h    "i2c::CAM"   Camera1 (external camera, right eye)    ;/
      3   1:4Ah    "i2c::MCU"   MCU (aka MCU registers for 3DS mode)
      4   1:78h    "i2c::CAM"   Camera2 (external camera, left eye)
      5   1:2Ch    "i2c::LCD"   Upper LCD screen (lcd0)
      6   1:2Eh    "i2c::LCD"   Lower LCD screen (lcd1)
      7   1:40h    "i2c::DEB"   Reserved for Debug?
      8   1:44h    "i2c::DEB"   Reserved for Debug?
      9   2:A6h/D6h"i2c::HID"   Debug?? addr changed from A6h to D6h in 8.0.0-18
      10  2:D0h    "i2c::HID"   Gyroscope (old version)  <-- read = FFh's ?
      11  2:D2h    "i2c::HID"   Gyroscope (new version)  <-- EXISTS in New3DS
      12  2:A4h    "i2c::HID"   Reserved for DebugPad
      13  2:9Ah    "i2c::IR"    Infrared Transmitter/Receiver (IrDA)
      14  2:A0h    "i2c::EEP"   Reserved for DebugEeprom?
      15  1:EEh    "i2c::NFC"   New3DS-only NFC (Near-field communication)
      16  0:40h    "i2c::QTM"   New3DS-only QTM (head tracking?) IO Expander!
      17  2:54h    "i2c::IR"    New3DS-only C-stick and ZL/ZR.. 44pin chip??
      -   none(?)  -            New3DS-only Hasn't co-packaged EEPROM in NFC chip?
      -   0:A0h    -            Reserved for Unknown DSi camera0 (Ext)
      -   0:E0h    -            Reserved for Unknown DSi camera1 (Self)
      -   0:40h    -            Reserved for Unknown DSi Debug stuff? and QTM
      -   0:90h    -            Reserved for Unknown DSi Debug stuff?
      -   0:00h-0Eh             Mirrors to BPTWL for whatever reason
      -   0:F0h-FEh             Mirrors to BPTWL for whatever reason
      -   0:5Ah                 Internal dummy addr used by BPTWL when busy?
      -   2:00h                 Unknown, something responds here with ACK and FFh's

Notice: These device addresses are used for writing to the respective device, for reading bit0 must be set (see I2C protocol).
3DS Secondary I2C Devices
There are also some internal/secondary I2C busses (not connected to the ARM CPUs).

      MCU:30h   Accelerometer                                 ;\
      MCU:6Ch   Fuel Gauge MAX17040 (or newer chip in New3DS) ; connected to
      MCU:84h   video related?   ;Power Managment Device?     ; MCU chip)
      MCU:A4h   batt.flg/volume? ;Touchscreen/Sound chip?     ;/
      Wifi:A0h  I2C bus EEPROM                   ;connected to Atheros Wifi chip
      NFC:Axh   NFC chip has on-chip CAT24C64 EEPROM (?), but not wired to ARM (?)

3DS I2C MCU Register Summary

Bus/Device 1:4Ah - MCU
The McuIndex is usually automatically incremented after each data byte (eg. allowing to read the two Version bytes in one pass).
However, there are a few arrays (at McuIndex=29h,2Dh,4Fh,61h,7Fh), which will increment the ArrayIndex instead of the McuIndex. This happens only if the index value (in the I2C command) was pointing to the array (eg. writing 5 bytes to index 29h will update the Power LED Array. But, writing 5 bytes to index 28h will update McuIndex 28h,29h,2Ah,2Bh,2Ch; without getting stuck at 29h, and thus updating only the 1st byte of the Power LED Array).
The extra-special case is using index 60h in the I2C command (it will increment once, then stay at index 61h).
MCU Registers

      00h     R    Version high (bit0-3) and hardware.type? (bit4-7)         ;\Firm
      01h     R    Version low (8bit)                                        ;/
      02h     R/W  Reset Event flags                                         ;-Stat
      03h     R/W  Top screen flicker                                        ;\
      04h     R/W  Bottom screen flicker                                     ;/
      05h-07h R/W  MCU Firmware update unlock sequence   ;ARRAY[4003h]       ;-Firm
      08h     R    Raw 3D slider position                                    ;\
      09h     R    Volume slider state (00h..3Fh) (as MCUHWC:GetSoundVolume) ;
      0Ah     R    Battery PCB Temperature Celsius (signed)                  ; Stat
      0Bh     R    Fuel Gauge Battery Percentage, msb (percent, 0..64h)      ;
      0Ch     R    Fuel Gauge Battery Percentage, lsb (percent/256, 0..FFh)  ;
      0Dh     R    Fuel Gauge Battery Voltage (in 20mV units)                ;
      0Eh     R    Sub-Device Access Flags? (bit0,1,2-3,4)                   ;
      0Fh     R    Power Status Flags                                        ;/
      10h-13h R    MCU Interrupt Flags, bit0-31 (1=IRQ, cleared after read)  ;\
      14h     R    Unused (cleared after reading, like above IRQ flags)      ;
      15h-17h R/W  Unused                                                    ; IRQs
      18h-1Bh R/W  MCU Interrupt Mask, bit0-31 (0=Enable, 1=Disable)         ;
      1Ch-1Fh R/W  Unused                                                    ;/
      20h     W    System power control (bits are 0=No change, 1=Trigger)    ;\
      21h     W    Change DSi Power Button Status register BPTWL[10h]        ;
      22h     W    Used to set LCD states (bits are 0=No change, 1=Trigger)  ; PWR
      23h     -    Unused (has a dummy write handler, but does nothing)      ;
      24h     R/W  Forced Power Off delay (0=Never, 1=Fastest, 5Dh=Insane)   ;/
      25h-26h R/W  Unused
      27h     R/W  Raw volume slider state                                   ;-
      28h     R/W  Brightness of Wifi/Power/3D LEDs                          ;\
      29h *   R/W  Power LED state + Power LED blink pattern ;ARRAY[5]       ;
      2Ah     R/W  Wifi LED state, 4 bits wide                               ; LEDs
      2Bh     R/W  Camera LED state, 4bits wide                              ;
      2Ch     R/W  3D LED state, 4 bits wide                                 ;
      2Dh *   W    Notification LED Array (4+3x20h bytes)    ;ARRAY[64h]     ;
      2Eh     R    Notification LED Status when read (1=new cycle started)   ;/
      2Fh     -    Unused (has a dummy write handler, but does nothing)
      30h     R/W  RTC Time second  (7bit)   (BCD, 00h..59h)                 ;\
      31h     R/W  RTC Time minute  (7bit)   (BCD, 00h..59h)                 ;
      32h     R/W  RTC Time hour    (6bit)   (BCD, 00h..23h)                 ;
      33h     R/W  RTC Time day of week? (3bit) (?..?, ?=Monday)             ;
                       (renesas calls this "Week 0=Sunday")                  ; RTC
                       (unknown what Nintendo is using here)                 ;
      34h     R/W  RTC Time day     (6bit)   (BCD, 01h..31h)                 ;
      35h     R/W  RTC Time month   (5bit)   (BCD, 01h..12h)                 ;
      36h     R/W  RTC Time year    (8bit)   (BCD, 00h..99h)                 ;
      37h     R/W  RTC Watch Error Correction (SUBCUD)  ;NOT leap year       ;
      38h     R/W  RTC Alarm minute (7bit)   (BCD, 00h..59h)                 ;
      39h     R/W  RTC Alarm hour   (6bit)   (BCD, 00h..23h)                 ;
      3Ah     R/W  RTC Alarm day    (6bit)   (BCD, 01h..31h) ;\maybe 0=off?  ;
      3Bh     R/W  RTC Alarm month  (5bit)   (BCD, 01h..12h) ;/              ;
      3Ch     R/W  RTC Alarm year   (8bit)   (BCD, 00h..99h)                 ;
      3Dh     R    RTC RSUBC.lsb (in 32768Hz units)         ;\range 0..7FFFh ;
      3Eh     R    RTC RSUBC.msb (latched when reading lsb) ;/(or 0..80xxh)  ;
      3Fh     W    RTC Flags (bit0=ScreenBlack?, bit1=DisableRtc32KHzOutput) ;/
      40h     R/W  Accelerometer Mode (bit0=AccelerometerOn, bit1=PedometerOn)   ;\
      41h     R/W  Accelerometer Index for Manual I2C Read via MCU[44h]          ;
      42h     R/W  Unused                                                        ;
      43h     R/W  Accelerometer Index for Manual I2C Write via MCU[44h]         ;
      44h     R/W  Accelerometer Data from/to Read/Write via MCU[41h/43h]        ;
      45h,46h R    Accelerometer Output X (lsb,msb) ;resting=+/-00xxh            ;
      47h,48h R    Accelerometer Output Y (lsb,msb) ;resting=+/-00xxh            ;
      49h,4Ah R    Accelerometer Output Z (lsb,msb) ;resting=-41xxh (gravity)    ;
      4Bh     R/W  Pedometer Step Count, bit0-7    ;\(for the current day)       ;
      4Ch     R/W  Pedometer Step Count, bit8-15   ; (uh, how/which day?)        ;
      4Dh     R/W  Pedometer Step Count, bit16-23  ;/(rather total count?)       ;
      4Eh     R/W  Pedometer Flags (Wr.bit0=ClearArray?, Rd.bit4=ArrayFull?)     ;
      4Fh *   R    Pedometer Timestamp[6] and StepCounts[2*A8h]  ;ARRAY[6+2*A8h] ;
      50h,51h R/W  Pedometer Minute,Second compare values (?)                    ;/
      52h-57h R/W  Unused, except some bytes are set to fixed values once and then
      58h     R/W  Volume slider calibration point for 0%   (default=36h)
      59h     R/W  Volume slider calibration point for 100% (default=C9h)
      5Ah     R/RW Invalid, do not use!
                     on newer MCU_FIRM versions this is set to FFh once and then
                     on older MCU_FIRM versions this is a read-only counter
      5Bh-5Fh -    N/A (write=ignored, read=FFh)
      60h *   R/W  Battery-backed RAM Index                                  ;\
      61h *   R/W  Battery-backed RAM Data (200 bytes) ;ARRAY[C8h]           ; Misc
      62h-7Eh -    N/A (write=ignored, read=FFh)                             ;
      7Fh *   R    Various system state information ;ARRAY[09h/13h]          ;/
      80h-FFh -    N/A (write=ignored, read=FFh)

Blurb
On old versions of MCU_FIRM none of the invalid registers are masked away by the read handler function, but are still read-only. Newer MCU_FIRM versions return the hardcoded value FF instead.
Reportedly register 3Bh (RTC Alarm month) "could be used on very old MCU_FIRM versions to upload MCU firmware if some conditions (?) are met", uh?.

3DS I2C MCU[00h-01h,05h-07h] - Firmware

MCU[00h] - Version high (bit0-3) and hardware.type? (bit4-7) (R)
MCU[01h] - Version low (8bit) (R)

      OldMCU: Version 0.008 or lower   ;\differs on LCD bits:
      NewMCU: Version 0.009 or higher  ;/backlight and "push"

MCU[05h-07h] - MCU Firmware update unlock sequence ;ARRAY[4003h] (R/W)
Updating MCU Firmware FLASH is done by writing 4003h bytes to MCU[05h and up]. The I2C transfer timings (and flash write timings) are automatically handled via SCL-hold. The upload takes about 2 seconds, and the console does then reboot the MCU... the backlights stay on, but I2C MCU access seems to be non-functional... for a while?
The first three bytes must be 6Ah,68h,6Ch (aka "jhl"), if the 3rd write does match (and 1st-2nd write were also correct), then the MCU switches to receiving a 4000h-byte firmware image. The image consists of two blocks:

      1000h bytes written to flash address 0000h-0FFFh (4K)
      3000h bytes written to flash address 2000h-4FFFh (12K)

For error checking, the image must contain three identical 9-byte "HH:MM:SS",00h timestamps:

      0FF6h..0FFEh - 1st timestamp
      2000h..2008h - 2nd timestamp
      4FF6h..4FFEh - 3rd timestamp

The first byte of the timestamp must be other than FFh, and the third byte must be ":".
BUG: The 1st/3rd timestamp are checked before applying the firmware update, but 2nd timestamp isn't checked until AFTER applying it (then causing blinking red power led, and requiring the reflash via UART pin).
3DS I2C MCU - RL78 Flash Programming via UART
Uploading bugged code may also require reflashing via UART (the UART stuff is handled in ROM, and works safely even if the whole flash is erased).
Firmware Inner Workings
The MCU contains a RL78 processor with reflashable firmware.
3DS I2C MCU - RL78 CPU Opcode List
3DS I2C MCU - RL78 CPU Opcode Map
3DS I2C MCU - RL78 CPU Registers and Flags
3DS I2C MCU - RL78 SFR Registers (Special Function Registers) (I/O ports)
3DS I2C MCU - RL78 Misc
Firmware Nocash MCU Patches
Code Execution in Battery RAM:

      MCU[05h-07h] = "exc"  --> Battery RAM code gets executed immediately
      MCU[05h-07h] = "exq"  --> Battery RAM code gets enqueued as callback
      Before execution, use MCU[61h] to upload code to Battery RAM, the RAM
      can be also used to store parameters and return values, you may want to
      restore the original RAM content after execution for not confusing the OS.
      The ROM/RAM memory map varies for different MCU firmware versions, however,
      the patched firmware provides useful ROM/RAM addresses in below tables,
      code should either use relative jumps, or addresses from those tables.

Call Table Vectors for ROM functions:

      00080h  Process Standard Callbacks    ;\
      00082h  Add Callback AX               ; Nintendo's own stuff (not useful)
      00084h  Process Enqueued Callbacks    ;/
      000B4h  I2C_Receive_Block             ;\Slave I2C recv/send (can be used
      000B6h  I2C_Send_Block                ;/from within callbacks only)
      000B8h  FLASH Init and kill IRQs      ;\
      000BAh  FLASH Erase 400h bytes        ; FLASH init/erase/write/finish
      000BCh  FLASH Write max 100h bytes    ; (eg. for custom code in backup area)
      000BEh  FLASH Finish 400h bytes       ;/

Pointers to RAM arrays:

      F4FE8h  MCU[00h..5Ah] Registers  (5Bh bytes)  ;\
      F4FEAh  MCU[61h] Battery RAM     (C8h bytes)  ; Pointers to RAM arrays
      F4FECh  MCU[2Dh] Notify LED RAM  (64h bytes)  ;
      F4FEEh  MCU[4Fh] Pedometer_array (150h bytes) ;/

Other General Patches:

      Faster power button tap duration (0s instead laggy delay)
      Faster power button hold duration (1s instead 3s)
      Changed Power LED color upon holding power button (purple)
      Faster shutdown after holding power button (can be 0s instead 12s)
      Faster shutdown after normal power down (omitting LED fade-out delay)

Firmware Image/Dumping
A copy of the firmware-image can be found in the System Modules folder,

      3ds:\title\00040130\00001f02\content\000000vv.app ;MCU
      3ds:\title\00040130\20001f02\content\000000vv.app ;MCU New3DS
      3ds:\title\00040130\00001f03\content\000000vv.app ;MCU Safe mode
      3ds:\title\00040130\20001f03\content\000000vv.app ;MCU Safe mode New3DS

The .app file contains a .code file with ARM11 code (and the MCU firmware somewhere inside of that .code file, usually at file offset A078h or A07Ch; starting with the 3-byte unlock code ("jhl"), followed by the 4000h-byte firmware image).
Dumping the firmware directly from FLASH memory isn't supported. However, one could patch the firmware, and then dump the backup of the old version (that will destroy the backup of the yet older version though).

3DS I2C MCU[02h-0Fh] - Status

MCU[02h] - Reset Event flags (R/W)
2bit value, writing will mask away/"acknowledge" the event, set to 3 by mcuMainLoop on reset if reset source is "Watchdog", uh?

      0    RTC clock value got reset to defaults           (R/ack)
      1    Watchdog reset happened                         (R/ack)
      2-4
      5    value from BPTWL[12h].bit7 (Unknown)               (R)
      6    value from BPTWL[12h].bit0 (1=IRQ on Pwr Butt tap) (R)
      7    value from BPTWL[12h].bit1 (Unknown)               (R)

actually, this register returns C0h or C1h
bit0 can be cleared by writing bit0=0 (writing bit0=1 has no effect)
MCU[03h] - Top screen flicker (R/W)
MCU[04h] - Bottom screen flicker (R/W)
Whatever. Maybe from HWCAL files?
MCU[08h] - Raw 3D slider position (R)
Slider.
MCU[09h] - Volume slider state (00h..3Fh) (as MCUHWC:GetSoundVolume) (R)
Slider.
MCU[0Ah] - Battery PCB Temperature Celsius (signed) (R)

      0-7  Degrees Celsius (51F3h-(ADC(8)*70h))/100h  ;signed, usually 17h..19h

MCU[0Bh] - Fuel Gauge Battery Percentage, msb (percent, 0..64h) (R)
MCU[0Ch] - Fuel Gauge Battery Percentage, lsb (percent/256, 0..FFh) (R)
Battery pecentage, from Fuel Gauge SOC register (State Of Charge).
MCU[0Dh] - Fuel Gauge Battery Voltage (in 20mV units) (R)
Battery voltage, from upper 8bit of Fuel Gauge VCELL register.
MCU[0Eh] - Sub-Device Access Flags? (bit0,1,2-3,4) (R)

      0    Device 6Ch Error (Fuel Gauge)    (0=Okay, 1=Error)
      1    Device 30h Error (Accelerometer) (0=Okay, 1=Error)
      2-3  Device A4h related (Volume etc.)    ;TSC[10h]
      4    LED brightness related
      5-7  Unused

Whatever.
MCU[0Fh] - Power Status Flags (R)

      0    Unused
      1    ShellState (hinge)  (1=Shell open)               ;\
      2    Unused                                           ; mcu::RTC
      3    AdapterState (Charger connected)                 ;
      4    BatteryChargeState  (1=Charging)                 ;/
      5    OldMCU: Unused                                   ;\
      6    OldMCU: something (1bit) ;\back-                 ; mcu::GPU
      5-6  NewMCU: something (2bit) ;/light(s)?             ;
      7    whatever                 ;-push?                 ;/

3DS I2C MCU[10h-1Fh] - Interrupt Flags

MCU[10h-13h] - MCU Interrupt Flags, bit0-31 (1=IRQ, cleared after read) (R)
MCU[18h-1Bh] - MCU Interrupt Mask, bit0-31 (0=Enable, 1=Disable) (R/W)

      0     Power button press (for 27 "ticks") aka 0.2s
      1     Power button held (for 375 "ticks" aka 3s, turns off after another 12s)
      2     HOME button press (for 5 "ticks") aka 0.04s
      3     HOME button release
      4     Wifi button press (for 5 "ticks") aka 0.04s
      5     Shell close
      6     Shell open
      7     Fatal hardware condition? (sent when MCU gets reset by Watchdog timer)
      8     Charger removed
      9     Charger plugged in
      10    RTC alarm
      11    Accelerometer I2C manual read/write done
      12    Accelerometer new XYZ sample update
      13    Battery dropped below 11%, 6% or 1% (warns at those 3 points)
      14    Battery charging stop (independent of charger state)
      15    Battery charging start
      16    TSC[10h].bit0=1=Whatever, or BPTWL[11h]=01h=Reset
      17    TSC[10h].bit6=1=Whateverelse
      18    TSC[10h].bit2 changed to zero
      19    TSC[10h].bit2 changed to one
      20    TSC[10h].bit3 changed to zero
      21    TSC[10h].bit3 changed to one
      22    Volume slider position change
      23    Read from BPTWL[00h] version register has occurred
      24    Video Display "push" off
      25    Video Display "push" on
      26    Video Bottom screen backlight off
      27    Video Bottom screen backlight on
      28    Video Top screen backlight off
      29    Video Top screen backlight on
      30    set by mcu sysmodule  ;\uh, flag bits aren't set by MCU (and can't be
      31    set by mcu sysmodule  ;/set by ARM), but maybe ARM sets mask bits..?

3DS I2C MCU[20h-24h] - Power Control

MCU[20h] - System power control (bits here are 0=No change, 1=Trigger) (W)

      0     Power off
      1     Reboot (unused?)
      2     Reboot (used by mcu sysmodule and LgyBg)
      3     Used by LgyBg to power off, causes hangs in 3DS-mode
      4     NewMCU: looks like power-off type (real power off, or sleep state...?)
              "an mcu::RTC command uses this, seems to do something with the
              watchdog: Bit 4 sets a bit at a RAM address which seems to control
              the watchdog timer state, then this bit is immediately unmasked.
              This field has a bitmask of 0x0F."
      4     OldMCU: Both backlights off
      5     OldMCU: Both backlights on
      6     OldMCU: Push to LCDs off   ;\uh, what is "push" ?
      7     OldMCU: Push to LCDs on    ;/

Unknown how to fully power-off. Writing 01h does somewhat power-off, but the battery still runs empty after 10-20 hours. Some people execute a Wait-for-Interrupt opcode after the I2C write; not tested if that does help (and if that opcode is needed on all ARM11 CPU core(s) and ARM9 side).
MCU[21h] - Change DSi Power Button Status register BPTWL[10h] (W)
00h=No Change, other=Shuffle bits and set BPTWL[10h]

      0     Copied to BPTWL[10h].bit3
      1     Copied to BPTWL[10h].bit0
      2     Copied to BPTWL[10h].bit1
      3     Copied to BPTWL[10h].bit5
      4     Copied to BPTWL[10h].bit4
      5     Copied to BPTWL[10h].bit6
      6-7   Not used (except, affect the "00h=No change" thing)

MCU[22h] - Used to set LCD states (bits here are 0=No change, 1=Trigger) (W)

      0     NewMCU: Push to LCDs off   ;\uh, what is "push" ?
      1     NewMCU: Push to LCDs on    ;/
      2     NewMCU: Bottom screen backlight off;\For 2DS:
      3     NewMCU: Bottom screen backlight on ;/both screens
      4     NewMCU: Top screen backlight off   ;\For 2DS:
      5     NewMCU: Top screen backlight on    ;/No effect

"The rest of the bits are masked away."
MCU[24h] - Forced Power Off delay (0=Never,1=Fastest,5Dh=InsaneDefault) (R/W)

      0-7   Delay in 8Hz units, this value seems to be battery backed
            (the value seems to also affect the bootrom error screen)

3DS I2C MCU[28h-2Eh] - LED Control

MCU[28h] - Brightness of Wifi/Power/3D LEDs (R/W)
Brightness for Wifi/Power/3D LEDs (when the LEDs are on). Range 00h..FFh (default is FFh=max).
MCU[29h] - Power LED state + Power LED blink pattern ;ARRAY[5] (R/W)
1st byte (Power LED mode):

      00h   = fade to brightness MCU[28h] with battery check
      01h   = fade to brightness MCU[28h]
      02h   = pulsating fade on/off with battery check
      03h   = fade to brightness 00h
      04h   = instantly set brightness 00h
      05h   = instantly set brightness FFh
      06h   = Blinking RED (affects Power+Notification LEDs)
      Other = Same as 00h

2nd..5th bytes (optional, if any written):

      Power LED Blink pattern (default is 55h,55h,55h,55h)

MCU[2Ah] - Wifi LED state, 4 bits wide (R/W)

      00h = Wifi LED always off
      01h..0Fh = Wifi LED on (and blink upon traffic?)

MCU[2Bh] - Camera LED state, 4bits wide (R/W)

      00h = Camera LED always off
      01h = Camera LED slowly blinking
      02h = Camera LED always on
      03h = Camera LED set via BPTWL[31h] (DSi mode)
      04h = Camera LED flash once (then switch to 00h=off)
      05h = Camera LED off once   (then switch to 02h=on)
      06h..0Fh = Invalid (same as 00h)

Camera LED exists only in older 3DS, not in New3DS. The camera LED uses a digital 1bit signal (without variable brightness).
MCU[2Ch] - 3D LED state, 4 bits wide (R/W)

      00h = 3D LED Off (or fade-out to zero)
      01h = 3D LED On  (or fade-in/out to MCU[28h] setting)
      02h..0Fh = Same as 01h (On)

3D LED exists only in older 3DS, not in New3DS.
MCU[2Dh] - Notification LED Array (4+3x20h bytes) ;ARRAY[64h] (W)

      [2Dh.00h]      ;Delay (0..FFh = Delay 1..100h)
      [2Dh.01h]      ;Brightness/divider or so?
      [2Dh.02h]      ;Speed, some timer compare value? (FFh=none?)
      [2Dh.03h]      ;unused
      [2Dh.04h..23h] ;data Red[0..1Fh]
      [2Dh.24h..43h] ;data Green[0..1Fh]
      [2Dh.44h..63h] ;data Blue[0..1Fh]

"It's possible to write data here with size less than 64h, and only that portion of the pattern data will get overwritten. Writing past the size of this register seems to do nothing. Reading from this register only returns zeroes."
MCU[2Eh] - Notification LED Status when read (1=new cycle started) (R)

      0     Flag
      1-7   Not used

3DS I2C MCU[30h-3Fh] - Real-Time Clock (RTC)

MCU[30h] - RTC Time second (7bit) (BCD, 00h..59h) (R/W)
MCU[31h] - RTC Time minute (7bit) (BCD, 00h..59h) (R/W)
MCU[32h] - RTC Time hour (6bit) (BCD, 00h..23h) (R/W)
MCU[33h] - RTC Time day of week? (3bit) (?..?, ?=Monday) (R/W)

                  (renesas calls this "Week 0=Sunday")
                  (unknown what Nintendo is using here)

MCU[34h] - RTC Time day (6bit) (BCD, 01h..31h) (R/W)
MCU[35h] - RTC Time month (5bit) (BCD, 01h..12h) (R/W)
MCU[36h] - RTC Time year (8bit) (BCD, 00h..99h) (R/W)
Date/time.
MCU[37h] - RTC Watch Error Correction (SUBCUD) (R/W) ;NOT leap year
Error correction. Signed 32768Hz offset or so?
MCU[38h] - RTC Alarm minute (7bit) (BCD, 00h..59h) (R/W)
MCU[39h] - RTC Alarm hour (6bit) (BCD, 00h..23h) (R/W)
MCU[3Ah] - RTC Alarm day (6bit) (BCD, 01h..31h) (R/W) ;\maybe 0=off?
MCU[3Bh] - RTC Alarm month (5bit) (BCD, 01h..12h) (R/W) ;/
MCU[3Ch] - RTC Alarm year (8bit) (BCD, 00h..99h) (R/W)
Alarm. Unknown how to enable/disable that feature (other than using a far-away date, or even using a non-BCD date). Also unknown if alarm is working while powered off, or while playing a game.
MCU[3Dh] - RTC RSUBC.lsb (in 32768Hz units) (R)
MCU[3Eh] - RTC RSUBC.msb (latched when reading lsb) (R)

      0-15  Range 0..7FFFh (or 0..80xxh)

MCU[3Fh] - RTC Flags (bit0=ScreenBlack?, bit1=DisableRtc32KHzOutput) (W)

      0     ScreenBlack?
      1     DisableRtc32KHzOutput? what for?

Legacy RTC Emulation
The 3DS can emulate GBA/NDS/DSi RTC's. That is, the 3DS software must read the battery-backed time from MCU RTC registers, and then copy it to the emulated RTC registers...
NDS/DSi Console RTC:
3DS GPIO Registers
GBA Cartridge RTC:
3DS Config - ARM7 Registers (GBA/NDS/DSi Mode)

3DS I2C MCU[40h-51h] - Accelerometer/Pedometer

MCU Registers

      40h     R/W  Accelerometer Mode (bit0=AccelerometerOn, bit1=PedometerOn)   ;\
      41h     R/W  Accelerometer Index for Manual I2C Read via MCU[44h]          ;
      42h     R/W  Unused                                                        ;
      43h     R/W  Accelerometer Index for Manual I2C Write via MCU[44h]         ;
      44h     R/W  Accelerometer Data from/to Read/Write via MCU[41h/43h]        ;
      45h,46h R    Accelerometer Output X (lsb,msb) ;resting=+/-00xxh            ;
      47h,48h R    Accelerometer Output Y (lsb,msb) ;resting=+/-00xxh            ;
      49h,4Ah R    Accelerometer Output Z (lsb,msb) ;resting=-41xxh (gravity)    ;
      4Bh     R/W  Pedometer Step Count, bit0-7    ;\(for the current day)       ;
      4Ch     R/W  Pedometer Step Count, bit8-15   ; (uh, how/which day?)        ;
      4Dh     R/W  Pedometer Step Count, bit16-23  ;/(rather total count?)       ;
                    An up/down movement (on whichever axis that corresponds      ;
                    to gravity direction) is treated as step; however, the       ;
                    first step isn't counted, so 5 continous steps would         ;
                    increment the counter by 4.                                  ;
      4Eh     R/W  Pedometer Flags (Wr.bit0=ClearArray?, Rd.bit4=ArrayFull?)     ;
      4Fh *   R    Pedometer Timestamp[6] and StepCounts[2*A8h]  ;ARRAY[6+2*A8h] ;
      50h,51h R/W  Pedometer Minute,Second compare values (?)                    ;/

Reading the Output X/Y/Z registers would be the normal way to get the accelerometer data (if enabled in the mode register).
Pedometer (Step counter)
The Pedometer is some software feature in the MCU that converts the accelerometer data to step counters.
Power-off switches the accelerometer power supply off. However, it is kept powered & can do step counting in sleep mode. Step counting is used for "Play Coins" and the pre-installed statistic tool "Omoide Kirokuchou" (probably has other name in english?).
Manual access to Accelerometer I2C registers
The manual read/write feature allows to view/modify I2C registers directly; for debugging/hacking purposes or so. The manual read/write seem to be done in a callback function (=not immediately after writing MCU[41h] or MCU[44h]), and, before touching further accelerometer registers, one must wait until the callback has executed (which is indicated by MCU.interrupt.bit11).
Accelerometer Chip
On Old3DS it is marked "2048, 33DH, X1MAQ", which is said to be ST LIS331DLH.
On New3DSXL it is marked "KXTKK, 40860, .3413", which might be a Kionix chip, resembling KXTIK, but with LIS331DLH-style register map & device address.
Both Old3DS and New3DSXL have the chip on the mainboard, somewhere underneath of the bottom-screen. That (and the exact location) may be important when interpreting the accelerometer data (ie. the chip isn't parallel with the top-screen unless the case is fully unfolded).
The Accelerometer chip is wired to the MCU, so it's I2C registers can be accessed only indirectly, through the MCU.

     ___________________ Internal Registes (for manual access) ___________________

Internal LIS331DLH Accelerometer I2C Register map (for manual access)

      Addr   Type Default  Name
      00h-0Eh  -  -        -               Reserved (do not modify)
      0Fh      R  00110010 WHO_AM_I        Device identification register (32h)
      10h-1Fh  -  -        -               Reserved (do not modify)
      20h      RW 00000111 CTRL_REG1       Power Control
      21h      RW 00000000 CTRL_REG2       Filter Control
      22h      RW 00000000 CTRL_REG3       Interrupt Control
      23h      RW 00000000 CTRL_REG4       Misc Control
      24h      RW 00000000 CTRL_REG5       Sleep to Wake Control
      25h      R  -        HP_FILTER_RESET High-Pass Filter Clear (Read=clear)
      26h      RW 00000000 REFERENCE       High-pass Filter Reference value
      27h      R  00000000 STATUS_REG      Output Status
      28h      R  output   OUT_X_L         Out.X.L ;\usually near +/-00xxh
      29h      R  output   OUT_X_H         OUT.X.H ;/
      2Ah      R  output   OUT_Y_L         OUT.Y.L ;\usually near +/-00xxh
      2Bh      R  output   OUT_Y_H         OUT.Y.H ;/
      2Ch      R  output   OUT_Z_L         OUT.Z.L ;\usually near -41xxh (gravity)
      2Dh      R  output   OUT_Z_H         OUT.Z.H ;/
      2Eh-2Fh  -  -        -               Reserved (do not modify)
      30h      RW 00000000 INT1_CFG        Interrupt 1 Config      ;\
      31h      R  00000000 INT1_SOURCE     Interrupt 1 Status      ; INT 1
      32h      RW 00000000 INT1_THS        Interrupt 1 Threshold   ;
      33h      RW 00000000 INT1_DURATION   Interrupt 1 Duration    ;/
      34h      RW 00000000 INT2_CFG        Interrupt 2 Config      ;\
      35h      R  00000000 INT2_SOURCE     Interrupt 2 Status      ; INT 2
      36h      RW 00000000 INT2_THS        Interrupt 2 Threshold   ;
      37h      RW 00000000 INT2_DURATION   Interrupt 2 Duration    ;/
      38h-3Fh  -  -        -               Reserved (do not modify)
      40h-7Fh  -  -        -               Undocumented (zero)
      80h-FFh              Same as 00h-7Fh, with auto-incrementing index

ACCL[0Fh] - WHO_AM_I - Device identification register (R)

      0-7  Fixed (32h for LIS331DLH)

ACCL[20h] - CTRL_REG1 - Power Control (R/W)

      0   Xen  X axis enable        (0=Disable, 1=Enable)               (default=1)
      1   Yen  Y axis enable        (0=Disable, 1=Enable)               (default=1)
      2   Zen  Z axis enable        (0=Disable, 1=Enable)               (default=1)
      3-4 DR   Data rate selection  (0=50Hz, Others: see Table 20)      (default=0)
      5-7 PM   Power mode selection (0=Power-down, Other: see Table 19) (default=0)

PM bits allow to select between power-down and two operating active modes. The device is in power-down mode when PD bits are set to "000" (default value after boot). Table 19 shows all the possible power mode configurations and respective output data rates. Output data in the low-power modes are computed with low-pass filter cut-off frequency defined by DR1, DR0 bits.
DR bits, in the normal-mode operation, select the data rate at which acceleration samples are produced. In low-power mode they define the output data resolution. Table 20 shows all the possible configuration for DR1 and DR0 bits.
Table 19. Power mode and low-power output data rate configurations:

      PM       Power mode selection     Output data rate ODR'LP
      00h      Power-down               --
      01h      Normal mode              <ODR>
      02h      Low-power                0.5Hz
      03h      Low-power                1Hz
      04h      Low-power                2Hz
      05h      Low-power                5Hz
      06h      Low-power                10Hz

Table 20. Normal-mode output data rate configurations and low-pass cut-off
frequencies:

      DR       Output Data Rate ODR     Low-pass filter cut-off frequency
      00h      50Hz                     37Hz
      01h      100Hz                    74Hz
      02h      400Hz                    292Hz
      03h      1000Hz                   780Hz

ACCL[21h] - CTRL_REG2 - Filter Control (R/W)

      0-1 HPCF  High pass filter cut-off frequency (HPc) (0..3 = 8,16,32,64)
      2   HPen1 High pass filter for interrupt 1 src (0=Bypassed, 1=Filter enabled)
      3   HPen2 High pass filter for interrupt 2 src (0=Bypassed, 1=Filter enabled)
      4   FDS   Filtered data selection (0=Internal filter bypassed, 1=Data from
                                          internal filter sent to output register)
      5-6 HPM   High pass filter mode   (0=Normal mode, Other=see Table 23)
      7   BOOT  Reboot memory content   (0=Normal mode, 1=Reboot memory content)

BOOT bit is used to refresh the content of internal registers stored in the flash memory block. At the device power up the content of the flash memory block is transferred to the internal registers related to trimming functions to permit a good behavior of the device itself.
If for any reason the content of trimming registers was changed it is sufficient to use this bit to restore correct values. When BOOT=1 the content of internal flash is copied inside corresponding internal registers and it is used to calibrate the device. These values are factory trimmed and they are different for every accelerometer. They permit a good behavior of the device and normally they have not to be changed. At the end of the boot process the BOOT bit is set again to 0.

     Table 23. High-pass filter mode configuration
      HPM    High-pass filter mode
      00h    Normal mode (reset reading HP_RESET_FILTER)
      01h    Reference signal for filtering
      02h    Normal mode (reset reading HP_RESET_FILTER)

HPCF[1:0]. These bits are used to configure high-pass filter cut-off frequency ft which is given by:

      ... XXX ...

The equation can be simplified to the following approximated equation:

      ... XXX ...

Table 24. High-pass filter cut-off frequency configuration

      HPcoeff2,1   ft [Hz]        ft [Hz]         ft [Hz]         ft [Hz]
                   Data rate=50Hz Data rate=100Hz Data rate=400Hz Data rate=1000Hz
      00           1              2               8               20
      01           0.5            1               4               10
      10           0.25           0.5             2               5
      11           0.125          0.25            1               2.5

ACCL[22h] - CTRL_REG3 - Interrupt Control (R/W)

      0-1  I1_CFG Data signal on INT 1 pad control bits (see table below)
      2    LIR1   Latch IRQ on INT1_SRC register, with INT1_SRC cleared by reading
                    INT1_SRC itself (0=IRQ not latched, 1=IRQ latched)
      3-4  I2_CFG Data signal on INT 2 pad control bits (see table below)
      5    LIR2   Latch IRQ on INT2_SRC register, with INT2_SRC cleared by reading
                    INT2_SRC itself (0=IRQ not latched, 1=IRQ latched)
      6    PP_OD  Interrupt Push-pull/Open drain    (0=Push-pull, 1=Open drain)
      7    IHL    Interrupt active high/low         (0=Active high, 1=Active low)

Table 27. Data signal on INT 1 and INT 2 pad

      I#_CFG INT1/INT2 Pad
      00h    Interrupt 1/2 source
      01h    Interrupt 1 source OR interrupt 2 source
      02h    Data ready
      03h    Boot running

ACCL[23h] - CTRL_REG4 - Misc Control (R/W)

      0    SIM    SPI serial interface mode (0=4-wire, 1=3-wire)
      1    ST     Self-test enable          (0=No, 1=Self-test)
      2    -      Reserved (0)
      3    STsign Self-test sign            (0=Self-test Plus; 1=Self-test Minus)
      4-5  FS     Full-scale selection      (0..3 = +/-2g, +/-4g, Reserved, +/-8g)
      6    BLE    Big/little endian data selection (0=Litte-endian, 1=Big-endian)
      7    BDU    Block data update (0=Continuos update, 1=Output registers
                                        not updated between MSB and LSB reading)

BDU bit is used to inhibit output registers update between the reading of upper and lower register parts. In default mode (BDU=0) the lower and upper register parts are updated continuously. If it is not sure to read faster than output data rate, it is recommended to set BDU=1. In this way, after the reading of the lower (upper) register part, the content of that output registers is not updated until the upper (lower) part is read too.
This feature avoids reading LSB and MSB related to different samples.
ACCL[24h] - CTRL_REG5 - Sleep to Wake Control (R/W)

      0-1  Turn-on mode selection for sleep to wake function (0 or 3)
      2-7  Reserved (0)

TurnOn bits are used for turning on the sleep to wake function.

      Table 32. Sleep to wake configuration
      TurnOn  Sleep to wake status
      00h     Sleep to wake function is disabled
      03h     Turned on: The device is in low power mode (ODR=Defined in CTRL_REG1)

Setting TurnOn=3 the "sleep to wake" function is enabled. When an interrupt event occurs the device is turned to normal mode increasing the ODR to the value defined in CTRL_REG1. Although the device is in normal mode, CTRL_REG1 content is not automatically changed to "normal mode" configuration.
ACCL[25h] - HP_FILTER_RESET - High-Pass Filter Clear content (R=clear)
Dummy register. Reading at this address zeroes instantaneously the content of the internal high pass-filter. If the high pass filter is enabled all three axes are instantaneously set to 0g.
This allows to overcome the settling time of the high pass filter.
ACCL[26h] - REFERENCE - High-pass Filter Reference value (R/W)

      0-7  Reference value for high-pass filter. Default=00h

This register sets the acceleration value taken as a reference for the high-pass filter output.
When filter is turned on (at least one of FDS, HPen2, or HPen1 bit is equal to 1) and HPM bits are set to "01", filter out is generated taking this value as a reference.
ACCL[27h] - STATUS_REG - Output Status (R)

      0  XDA    New X axis new data available           (0=No, 1=Available)
      1  YDA    New Y axis new data available           (0=No, 1=Available)
      2  ZDA    New Z axis new data available           (0=No, 1=Available)
      3  ZYXDA  New set of X,Y,Z axis available         (0=No, 1=Available)
      4  XOR    Overrun has overwritten X axis data     (0=No, 1=Overrun)
      5  YOR    Overrun has overwritten Y axis data     (0=No, 1=Overrun)
      6  ZOR    Overrun has overwritten Z axis data     (0=No, 1=Overrun)
      7  ZYXOR  Overrun has overwritten X,Y,Z axis data (0=No, 1=Overrun)

Overrun means that previous data got overwritten before it was read.
Unknown if the Status bits get cleared after reading the Status register, or after reading the Output registers, or elsewhere?
ACCL[28h,29h] - OUT_X_L, OUT_X_H - X-axis acceleration data (R)
ACCL[2Ah,2Bh] - OUT_Y_L, OUT_Y_H - Y-axis acceleration data (R)
ACCL[2Ch,2Dh] - OUT_Z_L, OUT_Z_H - Z-axis acceleration data (R)

      0-15  The value is expressed as two's complement.

ACCL[30h] - INT1_CFG - Interrupt 1 source Configuration (R/W)
ACCL[34h] - INT2_CFG - Interrupt 2 source Configuration (R/W)

      0  XLIE Enable interrupt generation on X low event  (0=Disable, 1=Enable)
      1  XHIE Enable interrupt generation on X high event (0=Disable, 1=Enable)
      2  YLIE Enable interrupt generation on Y low event  (0=Disable, 1=Enable)
      3  YHIE Enable interrupt generation on Y high event (0=Disable, 1=Enable)
      4  ZLIE Enable interrupt generation on Z low event  (0=Disable, 1=Enable)
      5  ZHIE Enable interrupt generation on Z high event (0=Disable, 1=Enable)
      6  6D   6 direction detection function enable.      (See table below)
      7  AOI  AND/OR combination of interrupt events.     (See table below)

The six X/Y/Z high/low events trigger when measured accel. value is higher/lower than preset threshold.
Interrupt mode configuration

      AOI 6D  Interrupt mode
      0   0   OR combination of interrupt events
      0   1   6 direction movement recognition
      1   0   AND combination of interrupt events
      1   1   6 direction position recognition

ACCL[31h] - INT1_SRC - Interrupt 1 source Status (R)
ACCL[35h] - INT2_SRC - Interrupt 2 source Status (R)

      0  XL  X low event has occurred            (0=No, 1=Yes)
      1  XH  X high event has occurred           (0=No, 1=Yes)
      2  YL  Y low event has occurred            (0=No, 1=Yes)
      3  YH  Y high event has occurred           (0=No, 1=Yes)
      4  ZL  Z low event has occurred            (0=No, 1=Yes)
      5  ZH  Z high event has occurred           (0=No, 1=Yes)
      6  IA  Interrupt active (0=No, 1=One or more interrupts have been generated)
      7  -   Reserved (0)

Reading at this address clears INTn_SRC.bit6 (and the interrupt signal on INTn pin) and allows the refreshment of data in the INTn_SRC register if the latched option was chosen.
ACCL[32h] - INT1_THS - Interrupt 1 threshold (R/W)
ACCL[36h] - INT2_THS - Interrupt 1? threshold (R/W)

      0-6  THS  Interrupt threshold. Default value: 000 0000
      7    -    Reserved (0)

ACCL[33h] - INT1_DURATION - Minimum duration of Interrupt 2? event (R/W)
ACCL[37h] - INT2_DURATION - Minimum duration of Interrupt 2 event (R/W)

      0-6  D    Duration value. Default value: 000 0000
      7    -    Reserved (0)

These bits set the minimum duration of the Interrupt 2(?) event to be recognized. Duration time steps and maximum values depend on the ODR chosen.

3DS I2C MCU[60h-7Fh] - Misc Status

MCU[60h] - Battery-backed RAM Index (R/W)
MCU[61h] - Battery-backed RAM Data (200 bytes) ;ARRAY[C8h] (R/W)
This is a battery-backed 200-byte general purpose RAM area. The MCU itself doesn't care about the RAM content. Instead, the ARM CPU can use it to store powerdown/error flags (and then check those flags on next boot).

     The 1st byte at array[00h] is used to store flags for managing FIRM/NS state:
      bit0 = "WirelessDisabled"
      bit1 = "SoftwareClosed"
      bit2 = "PowerOffInitiated"
      bit4 = "LegacyJumpProhibited"

When exceeding the C8h-byte array size: Writing to index=C8h..FFh is ignored (and the index is not incremented). Reading from index=C8h..FFh returns data=00h (and the index is incremented, and can wrap from index=FFh to index=00h).
MCU[7Fh] - Various system state information ;ARRAY[09h/13h] (R)

      [7Fh:00h] Value 00h..06h (console model? critical_hw_state?) (usually 00h ?)
      [7Fh:01h] Powerman Version (00h=normal) (from POW[00h])
      [7Fh:02h]     battery scheme? (0..7, or FFh) (maybe from middle-batt-pin?)
      [7Fh:03h] Fuel Gauge Version.msb      (00h) ;FUEL[02h]
      [7Fh:04h] Fuel Gauge Version.lsb      (12h) ;FUEL[03h]
      [7Fh:05h] Fuel Gauge Config.msb RCOMP (5Eh) ;FUEL[0Ch]
      [7Fh:06h] Battery PCB Temperature raw ADC(8) value; see MCU[0Ah] for celsius
      [7Fh:07h] Battery PCB Temperature flags (bit0=0=Bad, bit1=0=VeryBad?)
      [7Fh:08h] Fixed 01h on New3DS-XL (older 3DS can be 00h or 01h = what?)
     On MCU_FIRM major version 0:
      [7Fh:09h and up] unknown
     On MCU_FIRM major version 1:
      [7Fh:09h and up] unused (AAh)
     On MCU_FIRM major version 2 and up (or so):
      [7Fh:09h] Sys Model (0=3ds, 1=3dsXL, 2=New3ds, 3=2ds, 4=New3dsXL, 5=New2dsXL)
      [7Fh:0Ah] Power LED color         (0=Blue/off, 1=Red)
      [7Fh:0Bh] Power LED intensity     (00h..FFh)
      [7Fh:0Ch] 3D LED intensity        (00h..FFh)
      [7Fh:0Dh] RGB LED red intensity   (00h..FFh)
      [7Fh:0Eh] RGB LED green intensity (00h..FFh)
      [7Fh:0Fh] RGB LED blue intensity  (00h..FFh)
      [7Fh:10h] Camera LED state        (0=Off, 1=On)
      [7Fh:11h] Wifi LED intensity      (00h..FFh)
      [7Fh:12h] Raw button states
        bit0: Power button        (0=Pressed)
        bit1: Home button         (0=Pressed)
        bit2: Wifi button         (0=Pressed??) (installed in Old3DS only)
        bit5: Charger LED         (0=LED On, 1=LED Off)  ;\or vice-versa?
        bit6: Charger connected AND busy (0=Busy, 1=No)  ;/or one just "connected?"
        this byte is reset to 0 before an svcBreak takes effect, uh?
      [7Fh:13h and up] unused (FFh)

3DS I2C MCU secondary I2C Devices (on MCU bus)

Bus/Device MCU:30h - Accelerometer
See Accel chapter.
3DS I2C MCU[40h-51h] - Accelerometer/Pedometer
Bus/Device MCU:6Ch - Fuel Gauge

      index____________dir_;MAX17040___________;MAX17048___;Richtek RT9428___
      FUEL[02h]        R   ;VCELL, voltage     ;VCELL      ;VBAT
      FUEL[04h]        R   ;SOC, StateOfCharge ;SOC        ;SOC
      FUEL[06h]        W   ;MODE               ;MODE       ;CONTROL
      FUEL[08h]        R   ;VERSION            ;VERSION    ;DEVICE ID
      FUEL[0Ah]        -   ;-                  ;HIBRT      ;Status, dSOC
      FUEL[0Ch]        R/W ;RCOMP              ;CONFIG     ;CONFIG
      FUEL[0Eh]        R/W ;???                ;???        ;OCV (but read-only!)
      FUEL[14h]        -   ;-                  ;VALRT      ;-
      FUEL[16h]        -   ;-                  ;CRATE      ;-
      FUEL[18h]        -   ;-                  ;VRESET/ID  ;-
      FUEL[1Ah]        -   ;-                  ;STATUS     ;-
      FUEL[3Eh]        W   ;???                ;???        ;???
      FUEL[40h+0..3Eh] W   ;???                ;TABLE      ;???
      FUEL[80h+0..1Eh] W   ;???                ;???        ;???
      FUEL[FEh]        -   ;COMMAND            ;CMD        ;MFA

The fuel gauge registers are 16bit, big-endian (eg. "write(device,index,msb,lsb)").
One should always read/write 2 bytes. Trying to read a single byte from odd index does instead return the msb from even index. Trying to read more than 2 bytes does weirdly return each 2-byte pair TWICE, and does then advance to the next 2-byte pair.
Old3DS uses a small 8pin fuel gauge with marking 17040, which is apparently Maxim MAX17040.
New3DS uses a very tiny 8pin bga fuel gauge with marking 7048, which might be Maxim MAX17048 (although the MCU firmware uses some undocumented registers that aren't mentioned in MAX17048 datasheet). The MCU firmware seems to detect different fuel gauge versions/revisions, unknown which different chip(s) are used (eg. Richtek RT9428 would be also compatible).
Bus/Device MCU:84h - Power Managment Device

      POW[00h]  Powerman version? (can be read via MCU[7Fh:01h])
      POW[01h]  set to 00h,0Fh,1Fh
      POW[02h]  flags (bit0..bit4 or so)
      POW[03h]  flags (bit0, bit1)
      POW[04h]  backlight enable flags (bit0, bit1)
      POW[05h]  set to 00h,08h,27h   ;00h=Old3DS, 08h=New3DS, 27h=PowerOff??
      POW[06h]  from MCU[03h] ;top_screen_flicker
      POW[07h]  from MCU[04h] ;bottom_screen_flicker
      POW[08h..FFh] unused (mirrors of POW[00h..07h])

One should always read/write only 1 byte, trying to read more bytes returns FFh's for the extra bytes.
Bus/Device MCU:A4h - Touchscreen/Sound Controller

      TSC[10h]  flags?
      TSC[12h]  batt.low.flag (bit0)
      TSC[13h]  volume (38h..7Fh)
      TSC[20h]  set to AAh

One can read 1 or more bytes.

3DS I2C MCU - RL78 Flash Programming via UART

Setting Flash Programming Mode

      VDD      __/"""""""""""""""""""""""""""""
      /RESET   ______/"""""""""""""""""""""""""
      FLMD0    xx__/""""""""""""""""""""""""""" (high=flash mode)
      TOOL0    xx__/"""""""\_/"""""\_/"\_/""""" (merged uart rx/tx on one pin)

The 3DS seems to have wired some/all of the above pins to the test points covered by green solder stop layer.
Old3DS Mainboard (near headphone socket, all 6 pins under solderstop)

          ??   FLMD0  ??
         TP79  TP75  TP74
          _ |   _     _
         (_)'  (_)-  (_)-
          _     _     _
        -(_)   (_)-  (_)-
         TP78  TP76  TP77
         GND   TOOL1 TOOL0

New3DS-XL Mainboard (near headphone socket, right 4 pins under solderstop)

                               _   _
       _    _    _       TOOL0(_) (_)FLMD0
      (_)  (_)  (_)            _ x _
         ____    _    _  TOOL1(_) (_)/RESET
        (____|  (_)  (_)
        VDD18 PVDD18 GND

Wiring Programmer (PC Parallel Port, GPIO, UART, whatever) to 3DS MCU

      /RESET ----------------|>|------------ PC.Data1.Reset
      TOOL0  ------------o---|>|------------ PC.Data0.TX
                         |  BAT85   |  .---- PC.Busy.RX
      FLMD0  -----.      |          | / B
                  |      '--[33K]---|<  C
      PVDD18 -----'                 | \ E
                              BC547 |  v--.
      GND    -----------------------------o- PC.Ground

The 3DS MCU programming signals are 1.8V, two BAT85 Schottky diodes can be used as one-directional level changer (with replies ignored/skipped via hardcoded delays), an additional 10K-65K resistor and BC547 transistor can be used for bi-directional transfers.
Command Summary

      00h Reset (aka enter flash mode)
      13h Verify/compare
      14h --Undocumented-- verify/compare first 4 bytes of flash, if [000C3h].bit1
      19h --Undocumented-- resembles "internal verify" from write command
      20h Chip Erase
      22h Block Erase
      32h Block Blank check
      40h Write
      9Ah Set Baud Rate
      A0h Set Security
      B0h Get Checksum
      C0h Get Silicon Signature
      C5h Get Version

The relevant commands are Reset, Block Erase, and Write.
Response Status/Error Codes

      04h Command Number Error
      05h Parameter Error
      06h Normal Acknowledge (ACK) (okay)
      07h Checksum Error
      0Fh Verify Error
      10h Protect Error
      15h Negative Acknowledge (NACK)
      1Ah MRG10 Error (mrg, uh?)
      1Bh MRG11 Error (mrg, uh?)
      1Ch Write Error
      FFh N/A (for 2nd status byte, when 1st status byte was bad)

Command Frames (Command to chip)

      00h 1     Command Start (fixed=01h)
      01h 1     Length (LEN) (1..255, or 00h=256)
      02h 1     Command Number
      03h LEN-1 Command Parameters
      xxh 1     Checksum (01h minus all of the above bytes)
      xxh 1     Command End (fixed=03h)

Data Frames (Data to chip, and Data/Status from chip)

      00h 1     Data Start (fixed=02h)
      01h 1     Length (LEN) (1..255, or 00h=256)
      02h LEN   Data
      xxh 1     Checksum (02h minus all of the above bytes)
      xxh 1     Data End (03h=Last Data Frame, or 17h=More data frames follow)

Reset Command (aka Start/Sync)
Drag FLDM0 high (1.8V in 3DS) to enable programming mode, and drag /RESET low for a moment. Then exchange the following bytes/packets.
Low Pulse (from chip, should arrive within 10ms after releasing /RESET):

      00h 1     Low pulse (value 00h)  ;-transferred at 9600 bps

Low Pulses (to chip):

      00h 1     Low pulse (value 00h)  ;\chip autodetects baudrate based on
      01h 1     Low pulse (value 00h)  ;/transfer time for these two bytes

Command (to chip):

      00h 3     Start/Len/Command (01h,01h,00h)
      03h 2     Checksum/End      (CHK,03h)

Response (from chip):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code
      03h 2     Checksum/End      (CHK,03h)

Set Baudrate Command
Allows to set the baudrate, which isn't really needed because the baudrate is autodetected when sending the Reset pulses.
Recommended might be 57.6Kbps, higher rates aren't really useful because of the slow write duration. Tested/working rates are 9.6Kbps through 115.2Kbps, including odd nonstandard rates.
Bytes should be sent as 8N2 (8 databits, no parity, 2 stopbits). However, the chip seems to send only 1 stopbit. Nethertheless, it seems to insist on receiving 2 stopbits (alternately, one could send the 2nd stopbit before startbit).
Command (to chip):

      00h 3     Start/Len/Command (01h,06h,9Ah)
      03h 1     Sync/Connection Mode (00h=Microcontroller, 1=Programmer)
      04h 2     Baud rate, in whatever units
      06h 1     Noise filter (00h=Off, 01h=On)
      07h 1     Speed/voltage (00h=Fast 2.7V and up, 01h=Slow 1.8V and up)
      08h 2     Checksum/End      (CHK,03h)

Response (from chip):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code
      03h 2     Checksum/End      (CHK,03h)

Chip Erase Command
Erases the whole flash memory & security settings (unless the security settings did have disabled the Chip Erase command itself).
Command (to chip):

      00h 3     Start/Len/Command (01h,01h,20h)
      03h 2     Checksum/End      (CHK,03h)

Response (from chip):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code (chip erase result)
      03h 2     Checksum/End      (CHK,03h)

Block Erase Command
Blocks seem to be 1Kbyte (400h bytes). Erasing 1000h bytes at once does also work.
Command (to chip):

      00h 3     Start/Len/Command (01h,07h,22h)
      03h 3     Start address (MSB,MID,LSB) ;lower 10bit=000h  ;\400h byte boundary
      06h 3     End address   (MSB,MID,LSB) ;lower 10bit=3FFh  ;/
      09h 2     Checksum/End      (CHK,03h)

Response (from chip):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code (block erase result)
      03h 2     Checksum/End      (CHK,03h)

Block Blank Check Command
Command (to chip):

      00h 3     Start/Len/Command (01h,08h,32h)
      03h 3     Start address (MSB,MID,LSB) ;lower 10bit=000h  ;\400h byte boundary
      06h 3     End address   (MSB,MID,LSB) ;lower 10bit=3FFh  ;/
      09h 1     Type (00h=Before single block, 01h=Before chip erase)
      0Ah 2     Checksum/End      (CHK,03h)

Response (from chip):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code (block blank check result)
      03h 2     Checksum/End      (CHK,03h)

Write Command
Requires prior Erase command, max length for erase/write commands seems to be 1000h bytes. To quit flash mode & resume normal operation, it seems to be required to unplug battery supply for moment after having written all data.
Command (to chip):

      00h 3     Start/Len/Command (01h,07h,40h)
      03h 3     Start address (MSB,MID,LSB) ;lower 8bit=00h  ;\100h byte boundary
      06h 3     End address   (MSB,MID,LSB) ;lower 8bit=FFh  ;/
      09h 2     Checksum/End      (CHK,03h)

Response (from chip, after command):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code (command reception result)
      03h 2     Checksum/End      (CHK,03h)

Data (to chip):

      00h 2     Start/Len (02h,LEN) ;LEN=1..255 bytes, or 0=256 bytes
      02h LEN   Data (usually 256 bytes)
      xxh 2     Checksum/End      (CHK,03h/17h)  ;03h=Last, 17h=Nonlast

Response (from chip, circa 60ms after each data block):

      00h 2     Start/Len (02h,02h)
      02h 1     Status/Error code (data reception result)
      02h 1     Status/Error code (write result)
      04h 2     Checksum/End      (CHK,03h)

Response (from chip, extra response, about 1.5 seconds after LAST data block):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code (internal verify result)
      03h 2     Checksum/End      (CHK,03h)

Note: The ugly 1.5 seconds verify delay can avoided by issuing a chip reset instead of waiting for the final response.
Verify/Compare Command
Command (to chip):

      00h 3     Start/Len/Command (01h,07h,13h)
      03h 3     Start address (MSB,MID,LSB) ;lower 8bit=00h  ;\100h byte boundary
      06h 3     End address   (MSB,MID,LSB) ;lower 8bit=FFh  ;/
      09h 2     Checksum/End      (CHK,03h)

Response (from chip, after command):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code (command reception result)
      03h 2     Checksum/End      (CHK,03h)

Data (to chip):

      00h 2     Start/Len (02h,LEN)  ;LEN must be N*4 bytes (usually (1)00h bytes)
      02h LEN   Data
      xxh 2     Checksum/End      (CHK,03h/17h)  ;03h=Last, 17h=Nonlast

Response (from chip, after each data block):

      00h 2     Start/Len (02h,02h)
      02h 1     Status/Error code (data reception result)
      02h 1     Status/Error code (verify result) (always ACK/okay for Nonlast?)
      04h 2     Checksum/End      (CHK,03h)

With data LEN=4, this seems to allow dump the chip content via brute-force (but requires to send/receive trillions of bits to dump 4 bytes, and gets slower towards end of 100h-byte snippets).
Get Checksum Command
Command (to chip):

      00h 3     Start/Len/Command (01h,07h,B0h)
      03h 3     Start address (MSB,MID,LSB) ;lower 8bit=00h  ;\100h byte boundary
      06h 3     End address   (MSB,MID,LSB) ;lower 8bit=FFh  ;/blah: "from top 1KB"
      09h 2     Checksum/End      (CHK,03h)

Response (from chip, after command):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code (command reception result)
      03h 2     Checksum/End      (CHK,03h)

Data (from chip, after above response):

      00h 2     Start/Len (02h,02h)
      02h 2     Data checksum, 0000h minus all data bytes (MSB,LSB)
      04h 2     Checksum/End      (CHK,03h)

Set Security Command
Allows write protect flash areas. Don't touch (or use with care), some settings cannot be undone (not even via Chip Erase command).
Command (to chip):

      00h 3     Start/Len/Command (01h,03h,A0h)
      03h 2     Fixed (00h,00h)
      08h 2     Checksum/End      (CHK,03h)

Response (from chip):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code (command reception result)
      03h 2     Checksum/End      (CHK,03h)

Data (to chip):

      00h 2     Start/Len (02h,06h)   ;uh, len=6 (but below should have len=8)?
      02h 1     FLG   Security Flags (can disable write/erase etc.)
      03h 1     BOT   Boot cluster last block number ("fixed to 03h")
      04h 2     FSWS  Flash shield window start ("Higher bits, Lower bits")
      06h 2     FSWE  Flash shield window end   ("Higher bits, Lower bits")
      08h 2     FFH   Fixed (FFh,FFh)
      0Ah 2     Checksum/End      (CHK,03h)

Response (from chip):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code (security write result)
      03h 2     Checksum/End      (CHK,03h)

Response (from chip):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code (internal verify result)
      03h 2     Checksum/End      (CHK,03h)

Get Silicon Signature Command
Command (to chip):

      00h 3     Start/Len/Command (01h,01h,C0h)
      03h 2     Checksum/End      (CHK,03h)

Response (from chip, after command):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code (command reception result)
      03h 2     Checksum/End      (CHK,03h)

Data (from chip, after above response):

      00h 2     Start/Len (02h,1Bh)
      02h 1     VEN  Vendor                          (10h=NEC/Renseas) ;bit7=parity
      03h 1     MET  Macro extension code            (EFh)             ;bit7=parity
      04h 1     MSC  Macro function code             (04h)             ;bit7=parity
      05h 3     DET  Device extension code 1,2,3     (DCh,FDh,xxh)     ;bit7=parity
      08h 3     UAE  User flash size-1 (LSB,MID,MSB) (007FFFh, little-endian!)
      0Bh 10    DEV  Device name                     ("D79F0104  ", ASCII)
      15h 1     SCF  Security flag information                           ;\same as
      16h 1     BOT  Boot block number ("03h=fixed")                     ; from
      17h 2     FSWS Flash shield window start("Higher side, Lower side"); security
      19h 2     FSWE Flash shield window end  ("Higher side, Lower side"); command?
      1Bh 2     RES  Reserved (FFFFh)                                    ;/
      1Dh 2     Checksum/End      (CHK,03h)

Get Version Command
Command (to chip):

      00h 3     Start/Len/Command (01h,01h,C5h)
      03h 2     Checksum/End      (CHK,03h)

Response (from chip, after command):

      00h 2     Start/Len (02h,01h)
      02h 1     Status/Error code (command reception result)
      03h 2     Checksum/End      (CHK,03h)

Data (from chip, after above response):

      00h 2     Start/Len (02h,06h)
      02h 3     Device Version    (MSB,MID,LSB) (000000h)
      05h 3     Firmware Version  (MSB,MID,LSB) (010000h)
      08h 2     Checksum/End      (CHK,03h)

Notes
The above protocol is documented in the "78K0R/Kx3-L Flash Memory Programming" application note.
Unknown if verify/checksum could be tweaked to dump the current flash content. There is also an undocumented anti-dumping feature related to bytes at 000C4h (that's probably related to TOOL1 debug pin, not to TOOL0 serial flash pin).

3DS I2C MCU - RL78 CPU Opcode List

Move Byte

      09/29/49                 MOV A, [nnnn+B]/[nnnn+C]/[nnnn+BC]
      88/89/8A/8B/8C           MOV A, [nn+SP]/[DE]/[nn+DE]/[HL]/[nn+HL]
      8D/8E/8F                 MOV A, [saddr]/[sfr]/[nnnn]
      61C9/61E9                MOV A, [HL+B]/[HL+C]
      60/--/62/63/64/65/66/67  MOV A, X/-/C/B/E/D/L/H
      70/--/72/73/74/75/76/77  MOV X/-/C/B/E/D/L/H, A
      50/51/52/53/54/55/56/57  MOV X/A/C/B/E/D/L/H, imm8
      D8/--/F8/E8              MOV X/-/C/B, [saddr]
      D9/--/F9/E9              MOV X/-/C/B, [nnnn]
      E0/E1/E2/E3/E4/E5        MOV X/A/C/B/[saddr]/[nnnn], 1  ;native: ONEB
      F0/F1/F2/F3/F4/F5        MOV X/A/C/B/[saddr]/[nnnn], 0  ;native: CLRB
      41/61B8                  MOV ES, imm8/[saddr]
      18/28/48                 MOV [nnnn+B]/[nnnn+C]/[nnnn+BC], A
      98/99/9A/9B/9C           MOV [nn+SP]/[DE]/[nn+DE]/[HL]/[nn+HL], A
      9D/9E/9F                 MOV [saddr]/[sfr]/[nnnn], A
      61D9/61F9                MOV [HL+B]/[HL+C], A
      19/38/39                 MOV [nnnn+B]/[nnnn+C]/[nnnn+BC], imm8
      C8/CA/CC                 MOV [nn+SP]/[nn+DE]/[nn+HL], imm8
      CD/CE/CF                 MOV [saddr]/[sfr]/[nnnn], imm8
      08/--/618A/618B/618C/618D/618E/618F   XCH A, X/-/C/B/E/D/L/H
      61AC/61AD/61B9/61A9                   XCH A, [HL]/[HL+byte]/[HL+B]/[HL+C]
      61AE/61AF                             XCH A, [DE]/[DE+byte]
      61AB/61A8/61AA                        XCH A, [sfr]/[saddr]/[nnnn]

Move Word

      13/15/17/30              MOVW AX, BC/DE/HL/imm16
      59/69/79                 MOVW AX, [nnnn+B]/[nnnn+C]/[nnnn+BC]
      A8/A9/AA/AB/AC           MOVW AX, [nn+SP]/[DE]/[nn+DE]/[HL]/[nn+HL]
      AD/AE/AF                 MOVW AX, [saddrp]/[sfrp]/[nnnn]
      E6/E7                    MOVW AX/BC,1    ;native: ONEW AX/BC
      F6/F7                    MOVW AX/BC,0    ;native: CLRW AX/BC
      12/32/DA/DB              MOVW BC, AX/#imm16/[saddrp]/[nnnn]
      14/34/EA/EB              MOVW DE, AX/#imm16/[saddrp]/[nnnn]
      16/36/FA/FB              MOVW HL, AX/#imm16/[saddrp]/[nnnn]
      58/68/78                 MOVW [nnnn+B]/[nnnn+C]/[nnnn+BC], AX
      B8/B9/BA/BB/BC           MOVW [nn+SP]/[DE]/[nn+DE]/[HL]/[nn+HL], AX
      BD/BE/BF                 MOVW [saddrp]/[sfrp]/[nnnn], AX
      C9/CB                    MOVW [saddrp]/[sfrp], imm16
      C0/C2/C4/C6/61CD         POP  AX/BC/DE/HL/PSW
      C1/C3/C5/C7/61DD         PUSH AX/BC/DE/HL/PSW
      33/35/37                 XCHW AX, BC/DE/HL

ALU Byte

      6100/6101/6102/6103/6104/6105/6106/6107  ADD  X/A/C/B/E/D/L/H, A
      6110/6111/6112/6113/6114/6115/6116/6117  ADDC X/A/C/B/E/D/L/H, A
      6120/6121/6122/6123/6124/6125/6126/6127  SUB  X/A/C/B/E/D/L/H, A
      6130/6131/6132/6133/6134/6135/6136/6137  SUBC X/A/C/B/E/D/L/H, A
      6140/6141/6142/6143/6144/6145/6146/6147  CMP  X/A/C/B/E/D/L/H, A
      6150/6151/6152/6153/6154/6155/6156/6157  AND  X/A/C/B/E/D/L/H, A
      6160/6161/6162/6163/6164/6165/6166/6167  OR   X/A/C/B/E/D/L/H, A
      6170/6171/6172/6173/6174/6175/6176/6177  XOR  X/A/C/B/E/D/L/H, A
      6108/----/610A/610B/610C/610D/610E/610F  ADD  A, X/-/C/B/E/D/L/H
      6118/----/611A/611B/611C/611D/611E/611F  ADDC A, X/-/C/B/E/D/L/H
      6128/----/612A/612B/612C/612D/612E/612F  SUB  A, X/-/C/B/E/D/L/H
      6138/----/613A/613B/613C/613D/613E/613F  SUBC A, X/-/C/B/E/D/L/H
      6148/----/614A/614B/614C/614D/614E/614F  CMP  A, X/-/C/B/E/D/L/H
      6158/----/615A/615B/615C/615D/615E/615F  AND  A, X/-/C/B/E/D/L/H
      6168/----/616A/616B/616C/616D/616E/616F  OR   A, X/-/C/B/E/D/L/H
      6178/----/617A/617B/617C/617D/617E/617F  XOR  A, X/-/C/B/E/D/L/H
      0B/0C/0D/0E/0F                ADD  A,[saddr]/#byte/[HL]/[HL+byte]/[nnnn]
      1B/1C/1D/1E/1F                ADDC A,[saddr]/#byte/[HL]/[HL+byte]/[nnnn]
      2B/2C/2D/2E/2F                SUB  A,[saddr]/#byte/[HL]/[HL+byte]/[nnnn]
      3B/3C/3D/3E/3F                SUBC A,[saddr]/#byte/[HL]/[HL+byte]/[nnnn]
      4B/4C/4D/4E/4F                CMP  A,[saddr]/#byte/[HL]/[HL+byte]/[nnnn]
      5B/5C/5D/5E/5F                AND  A,[saddr]/#byte/[HL]/[HL+byte]/[nnnn]
      6B/6C/6D/6E/6F                OR   A,[saddr]/#byte/[HL]/[HL+byte]/[nnnn]
      7B/7C/7D/7E/7F                XOR  A,[saddr]/#byte/[HL]/[HL+byte]/[nnnn]
      0A                            ADD  [saddr],#byte
      1A                            ADDC [saddr],#byte
      2A                            SUB  [saddr],#byte
      3A                            SUBC [saddr],#byte
      4A/40                         CMP  [saddr]/[nnnn],#byte
      5A                            AND  [saddr],#byte
      6A                            OR   [saddr],#byte
      7A                            XOR  [saddr],#byte
      D0/D1/D2/D3/D4/D5             CMP  X/A/C/B/[saddr]/[nnnn],0  ;native: CMP0
      80/81/82/83/84/85/86/87/A0/A4/6159 INC X/A/C/B/E/D/L/H/[nnnn]/[saddr]/[HL+nn]
      90/91/92/93/94/95/96/97/B0/B4/6169 DEC X/A/C/B/E/D/L/H/[nnnn]/[saddr]/[HL+nn]

ALU Word

      01/03/05/07              ADDW AX, AX/BC/DE/HL
      --/23/25/27              SUBW AX, --/BC/DE/HL
      --/43/45/47              CMPW AX, --/BC/DE/HL
      04/02/06/6109/10         ADDW AX, nnnn/[nnnn]/[saddrp]/[HL+nn] / ADDW SP,00nn
      24/22/26/6129/20         SUBW AX, nnnn/[nnnn]/[saddrp]/[HL+nn] / SUBW SP,00nn
      44/42/46/6149/--         CMPW AX, nnnn/[nnnn]/[saddrp]/[HL+nn] / CMPW --
      A1/A3/A5/A7/A2/A6/6179   INCW AX/BC/DE/HL/[nnnn]/[saddrp]/[HL+nn]
      B1/B3/B5/B7/B2/B6/6189   DECW AX/BC/DE/HL/[nnnn]/[saddrp]/[HL+nn]

Rotate/Shift

      61DB                  ROR A, 1
      61EB                  ROL A, 1
      61FB                  RCR A, 1         ;native: RORC A,1
      61DC                  RCL A, 1         ;native: ROLC A,1
      3109/3108/3107+n*10   SHL A/B/C, 1..7
      310A+n*10             SHR A, 1..7
      310B+n*10             SAR A, 1..7
      61EE/61FE             RCLW AX/BC, 1    ;native: ROLWC AX/BC,1
      310D/310C+n*10        SHLW AX/BC, 1..15
      310E+n*10             SHRW AX, 1..15
      310F+n*10             SARW AX, 1..15

Jump/Call

      61CB                  JMP AX                  ;native: BR AX             ;CS:
      ECnnnn0n              JMP absolute far addr   ;native: BR !!addr20
      EDnnnn                JMP absolute addr       ;native: BR !addr16
      EEnnnn                JMP relative addr       ;native: BR $!addr20
      EFnn                  JMP relative short addr ;native: BR $addr20
      61CA/61DA/61EA/61FA   CALL AX/BC/DE/HL        ;native: CALL AX/BC/DE/HL  ;CS:
      FCnnnn0n              CALL absolute far addr  ;native: CALL !!addr20
      FDnnnn                CALL absolute addr      ;native: CALL !addr16
      FEnnnn                CALL relative addr      ;native: CALL $!addr20
      61nn                  CALL [000xx]            ;native: CALLT [xx]

Conditional Relative Jumps

      DCnn                  JC  aka JB  addr  ;carry/below      ;native: BC
      DDnn                  JZ  aka JE  addr  ;zero/equal       ;native: BZ
      61C3nn                JH  aka JA  addr  ;higher/above     ;native: BH
      DEnn                  JNC aka JAE addr  ;not carry/below  ;native: BNC
      DFnn                  JNZ aka JNE addr  ;not zero/equal   ;native: BNZ
      61D3nn                JNH aka JBE addr  ;not higher/above ;native: BNH

Test (and Clear) and Conditional Relative Jump

      3100/3180/3181/3101+n*10h  BTCLR|JNZCLR [saddr]/[sfr]/[HL]/A.n, addr
      3102/3182/3183/3103+n*10h  BT|JNZ       [saddr]/[sfr]/[HL]/A.n, addr
      3104/3184/3185/3105+n*10h  BF|JZ        [saddr]/[sfr]/[HL]/A.n, addr

Bit Manipulation

      7101/7109/7181/7189+n*10            MOV1 [saddr]/[sfr]/[HL]/A.n, CY
      7104/710C/7184/718C+n*10            MOV1 CY, [saddr]/[sfr]/[HL]/A.n
      7105/710D/7185/718D+n*10            AND1 CY, [saddr]/[sfr]/[HL]/A.n
      7106/710E/7186/718E+n*10            OR1  CY, [saddr]/[sfr]/[HL]/A.n
      7107/710F/7187/718F+n*10            XOR1 CY, [saddr]/[sfr]/[HL]/A.n
      7180/7100/7102/710A/7182/718A+n*10  SET1 CY/[nnnn]/[saddr]/[sfr]/[HL]/A.n
      7188/7108/7103/710B/7183/718B+n*10  CLR1 CY/[nnnn]/[saddr]/[sfr]/[HL]/A.n
      71C0                                NOT1 CY

Misc

      00                             NOP
      61CC/61ED/61FD                 BRK/HALT/STOP
      D7/61EC/61FC                   RET/RETB/RETI
      FF                             TRAP     ;pseudo invalid.reset
      717AFA/717BFA                  EI/DI    ;pseudo set/clr.sfr.bit
      61C8/61D8/61E8/61F8/61E3/61F3  SKC/SKNC/SKZ/SKNZ/SKH/SKNH  ;conditional skip
      61CE                           MOVS [HL+byte],X
      61DE                           CMPS X,[HL+byte]
      61CF/61DF/61EF/61FF            SEL RB0/1/2/3
      D6                             MULU X   ;unsigned multiply AX=A*X
      11                             prefix for [ES:addr]   ;native: ES:addr[reg]

3DS I2C MCU - RL78 CPU Opcode Map

Instruction Map (1st Map) (without prefix)

          00               10                 20               30
      00  NOP              ADDW SP,#byte      SUBW SP,#byte    MOVW AX,#word
      01  ADDW AX,AX       PREFIX (ES:)       -                4th MAP !!!
      02  ADDW AX,!addr16  MOVW BC,AX         SUBW AX,!addr16  MOVW BC,#word
      03  ADDW AX,BC       MOVW AX,BC         SUBW AX,BC       XCHW AX,BC
      04  ADDW AX,#word    MOVW DE,AX         SUBW AX,#word    MOVW DE,#word
      05  ADDW AX,DE       MOVW AX,DE         SUBW AX,DE       XCHW AX,DE
      06  ADDW AX,saddrp   MOVW HL,AX         SUBW AX,saddrp   MOVW HL,#word
      07  ADDW AX,HL       MOVW AX,HL         SUBW AX,HL       XCHW AX,HL
      08  XCH  A,X         MOV  word[B],A     MOV  word[C],A   MOV  word[C],#byte
      09  MOV  A,word[B]   MOV  word[B],#byte MOV  A,word[C]   MOV  word[BC],#byte
      0A  ADD  saddr,#byte ADDC saddr,#byte   SUB  saddr,#byte SUBC saddr,#byte
      0B  ADD  A,saddr     ADDC A,saddr       SUB  A,saddr     SUBC A,saddr
      0C  ADD  A,#byte     ADDC A,#byte       SUB  A,#byte     SUBC A,#byte
      0D  ADD  A,[HL]      ADDC A,[HL]        SUB  A,[HL]      SUBC A,[HL]
      0E  ADD  A,[HL+byte] ADDC A,[HL+byte]   SUB  A,[HL+byte] SUBC A,[HL+byte]
      0F  ADD  A,!addr16   ADDC A,!addr16     SUB  A,!addr16   SUBC A,!addr16

          40                 50               60               70
      40  CMP  !addr16,#byte MOV  X,#byte     MOV  A,X         MOV  X,A
      41  MOV  ES,#byte      MOV  A,#byte     2nd MAP !!!      3rd MAP !!!
      42  CMPW AX,!addr16    MOV  C,#byte     MOV  A,C         MOV  C,A
      43  CMPW AX,BC         MOV  B,#byte     MOV  A,B         MOV  B,A
      44  CMPW AX,#word      MOV  E,#byte     MOV  A,E         MOV  E,A
      45  CMPW AX,DE         MOV  D,#byte     MOV  A,D         MOV  D,A
      46  CMPW AX,saddrp     MOV  L,#byte     MOV  A,L         MOV  L,A
      47  CMPW AX,HL         MOV  H,#byte     MOV  A,H         MOV  H,A
      48  MOV  word[BC],A    MOVW word[B],AX  MOVW word[C],AX  MOVW word[BC],AX
      49  MOV  A,word[BC]    MOVW AX,word[B]  MOVW AX,word[C]  MOVW AX,word[BC]
      4A  CMP  saddr,#byte   AND  saddr,#byte OR   saddr,#byte XOR  saddr,#byte
      4B  CMP  A,saddr       AND  A,saddr     OR   A,saddr     XOR  A,saddr
      4C  CMP  A,#byte       AND  A,#byte     OR   A,#byte     XOR  A,#byte
      4D  CMP  A,[HL]        AND  A,[HL]      OR   A,[HL]      XOR  A,[HL]
      4E  CMP  A,[HL+byte]   AND  A,[HL+byte] OR   A,[HL+byte] XOR  A,[HL+byte]
      4F  CMP  A,!addr16     AND  A,!addr16   OR   A,!addr16   XOR  A,!addr16

          80                 90               A0                B0
      80  INC  X             DEC  X           INC  !addr16      DEC  !addr16
      81  INC  A             DEC  A           INCW AX           DECW AX
      82  INC  C             DEC  C           INCW !addr16      DECW !addr16
      83  INC  B             DEC  B           INCW BC           DECW BC
      84  INC  E             DEC  E           INC  saddr        DEC  saddr
      85  INC  D             DEC  D           INCW DE           DECW DE
      86  INC  L             DEC  L           INCW saddrp       DECW saddrp
      87  INC  H             DEC  H           INCW HL           DECW HL
      88  MOV  A,[SP+byte]   MOV  [SP+byte],A MOVW AX,[SP+byte] MOVW [SP+byte],AX
      89  MOV  A,[DE]        MOV  [DE],A      MOVW AX,[DE]      MOVW [DE],AX
      8A  MOV  A,[DE+byte]   MOV  [DE+byte],A MOVW AX,[DE+byte] MOVW [DE+byte],AX
      8B  MOV  A,[HL]        MOV  [HL],A      MOVW AX,[HL]      MOVW [HL],AX
      8C  MOV  A,[HL+byte]   MOV  [HL+byte],A MOVW AX,[HL+byte] MOVW [HL+byte],AX
      8D  MOV  A,saddr       MOV  saddr,A     MOVW AX,saddrp    MOVW saddrp,AX
      8E  MOV  A,sfr         MOV  sfr,A       MOVW AX,sfrp      MOVW sfrp,AX
      8F  MOV  A,!addr16     MOV  !addr16,A   MOVW AX,!addr16   MOVW !addr16,AX

          C0                   D0                E0               F0
      C0  POP  AX              CMP0 X            ONEB X           CLRB X
      C1  PUSH AX              CMP0 A            ONEB A           CLRB A
      C2  POP  BC              CMP0 C            ONEB C           CLRB C
      C3  PUSH BC              CMP0 B            ONEB B           CLRB B
      C4  POP  DE              CMP0 saddr        ONEB saddr       CLRB saddr
      C5  PUSH DE              CMP0 !addr16      ONEB !addr16     CLRB !addr16
      C6  POP  HL              MULU X ;(AX=A*X)  ONEW AX          CLRW AX
      C7  PUSH HL              RET               ONEW BC          CLRW BC
      C8  MOV  [SP+byte],#byte MOV  X,saddr      MOV  B,saddr     MOV  C,saddr
      C9  MOVW saddrp,#word    MOV  X,!addr16    MOV  B,!addr16   MOV  C,!addr16
      CA  MOV  [DE+byte],#byte MOVW BC,saddrp    MOVW DE,saddrp   MOVW HL,saddrp
      CB  MOVW sfrp,#word      MOVW BC,!addr16   MOVW DE,!addr16  MOVW HL,!addr16
      CC  MOV  [HL+byte],#byte BC   $addr20      BR   !!addr20    CALL !!addr20
      CD  MOV  saddr,#byte     BZ   $addr20      BR   !addr16     CALL !addr16
      CE  MOV  sfr,#byte       BNC  $addr20      BR   $!addr20    CALL $!addr20
      CF  MOV  !addr16,#byte   BNZ  $addr20      BR   $addr20     - (TRAP)

Opcode FFh = TRAP (illegal opcode, used by 3DS MCU, triggers Reset vector).
Uh, other/prefixed illegal opcodes do not act as TRAP?
Instruction Map (2nd MAP) (with prefix byte 61h)

          00    10    20    30    40    50    60    70      Notes
      00  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands X,A
      01  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands A,A
      02  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands C,A
      03  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands B,A
      04  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands E,A
      05  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands D,A
      06  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands L,A
      07  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands H,A
      08  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands A,X
      09  ADDW  -     SUBW  -     CMPW  INC   DEC   INCW    <see below>
      0A  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands A,C
      0B  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands A,B
      0C  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands A,E
      0D  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands A,D
      0E  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands A,L
      0F  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands A,H
      80  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands A,[HL+B]
      81  -     -     -     -     -     -     -     -       -
      82  ADD   ADDC  SUB   SUBC  CMP   AND   OR    XOR     with operands A,[HL+C]
      83  -     -     -     -     BH    BNH   SKH   SKNH    <see below>
      84  [80h] [82h] [84h] [86h] [88h] [8Ah] [8Ch] [8Eh]   CALLT [0008xh]
      85  [90h] [92h] [94h] [96h] [98h] [9Ah] [9Ch] [9Eh]   CALLT [0009xh]
      86  [A0h] [A2h] [A4h] [A6h] [A8h] [AAh] [ACh] [AEh]   CALLT [000Axh]
      87  [B0h] [B2h] [B4h] [B6h] [B8h] [BAh] [BCh] [BEh]   CALLT [000Bxh]
      88  -     -     XCH   MOV   SKC   SKNC  SKZ   SKNZ    <see below>
      89  DECW  -     XCH   XCH   MOV   MOV   MOV   MOV     <see below>
      8A  XCH   -     XCH   -     CALL  CALL  CALL  CALL    <see below>
      8B  XCH   -     XCH   -     BR    ROR   ROL   RORC    <see below>
      8C  XCH   -     XCH   -     BRK   ROLC  RETB  RETI    <see below>
      8D  XCH   -     XCH   -     POP   PUSH  HALT  STOP    <see below>
      8E  XCH   -     XCH   -     MOVS  CMPS  ROLWC ROLWC   <see below>
      8F  XCH   -     XCH   -     SEL   SEL   SEL   SEL     <see below>

Operands for above opcodes:

      Operands for ADDW/SUBW/CMPW                AX,[HL+byte]
      Operands for INCW/DECW/INC/DEC             [HL+byte]
      Operands for BR                            AX
      Operands for ROL/ROR/ROLC/RORC             A,1
      Operands for PUSH/POP                      PSW
      Operands for MOVS                          [HL+byte],X
      Operands for CMPS                          X,[HL+byte]
      Operands for SKC/SKNC/SKZ/SKNZ/SKH/SKNH    None
      Operands for BRK/RETB/RETI/HALT/STOP       None
      Operands for BH/BNH                        $addr20
      Operands for ROLWC (opcode EE/FE)          AX,1 / BC,1
      Operands for CALL  (opcode CA/DA/EA/FA)    AX/BC/DE/HL
      Operands for SEL   (opcode CF/DF/EF/FF)    RB0/RB1/RB2/RB3
      Operands for MOV   (opcode C9/D9)          A,[HL+B] / [HL+B],A
      Operands for MOV   (opcode E9/F9/B8)       A,[HL+C] / [HL+C],A / ES,saddr
      Operands for XCH   (opcode 8A..8F)         A,C / A,B / A,E / A,D / A,L / A,H
      Operands for XCH   (opcode A8,A9,AA)       A,saddr / A,[HL+C] / A,!addr16
      Operands for XCH   (opcode AB,AC,AD)       A,sfr /  A,[HL] / A,[HL+byte]
      Operands for XCH   (opcode AE,AF,B9)       A,[DE] / A,[DE+byte] / A,[HL+B]

Note Not mounted on the RL78-S1 core.
Instruction Map (3rd MAP) (with prefix byte 71h)

      00+#*10  SET1 !addr16.#          80+#*10  --> see below (80,C0)
      01+#*10  MOV1 saddr.#,CY         81+#*10  MOV1 [HL].#,CY
      02+#*10  SET1 saddr.#            82+#*10  SET1 [HL].#
      03+#*10  CLR1 saddr.#            83+#*10  CLR1 [HL].#
      04+#*10  MOV1 CY,saddr.#         84+#*10  MOV1 CY,[HL].#
      05+#*10  AND1 CY,saddr.#         85+#*10  AND1 CY,[HL].#
      06+#*10  OR1  CY,saddr.#         86+#*10  OR1  CY,[HL].#
      07+#*10  XOR1 CY,saddr.#         87+#*10  XOR1 CY,[HL].#
      08+#*10  CLR1 !addr16.#          88+#*10  --> see below (88)
      09+#*10  MOV1 sfr.#,CY           89+#*10  MOV1 A.#,CY
      0A+#*10  SET1 sfr.#              8A+#*10  SET1 A.#
      0B+#*10  CLR1 sfr.#              8B+#*10  CLR1 A.#
      0C+#*10  MOV1 CY,sfr.#           8C+#*10  MOV1 CY,A.#
      0D+#*10  AND1 CY,sfr.#           8D+#*10  AND1 CY,A.#
      0E+#*10  OR1  CY,sfr.#           8E+#*10  OR1  CY,A.#
      0F+#*10  XOR1 CY,sfr.#           8F+#*10  XOR1 CY,A.#
      80       SET1 CY                 90,A0,B0             reserved
      88       CLR1 CY                 D0,E0,F0             reserved
      C0       NOT1 CY                 98,A8,B8,C8,D8,E8,F8 reserved

Instruction Map (4th MAP) (with prefix byte 31h)

      00+#*10  BTCLR saddr.#,$addr20 ;\
      01+#*10  BTCLR A.#,    $addr20 ;
      80+#*10  BTCLR sfr.#,  $addr20 ;
      81+#*10  BTCLR [HL].#, $addr20 ;
      02+#*10  BT    saddr.#,$addr20 ; #=0..7
      03+#*10  BT    A.#,    $addr20 ;
      82+#*10  BT    sfr.#,  $addr20 ;
      83+#*10  BT    [HL].#, $addr20 ;
      04+#*10  BF    saddr.#,$addr20 ;
      05+#*10  BF    A.#,    $addr20 ;
      84+#*10  BF    sfr.#,  $addr20 ;
      85+#*10  BF    [HL].#, $addr20 ;/
      06+#*10  -                     ;-#=N/A (0..15=reserved)
      07+#*10  SHL   C,#             ;\
      08+#*10  SHL   B,#             ;
      09+#*10  SHL   A,#             ; #=1..7 (0,8..15=reserved)
      0A+#*10  SHR   A,#             ;
      0B+#*10  SAR   A,#             ;/
      0C+#*10  SHLW  BC,#            ;\
      0D+#*10  SHLW  AX,#            ; #=1..15 (0=reserved)
      0E+#*10  SHRW  AX,#            ;
      0F+#*10  SARW  AX,#            ;/

Pseudo Opcodes

      EI         71 7A FA         ;SET1 SFR(FAh).7  (PSW.bit7 enable interrupts)
      DI         71 7B FA         ;CLR1 SFR(FAh).7  (PSW.bit7 disable interrupts)
      TRAP       FF               ;invalid opcode FF (triggers Reset vector)

Extra MUL opcodes (unknown if these are supported on 3DS):

      MULHU      CE FB 01         ;MOV SFR(FBh),#01h    Note
      MULH       CE FB 02         ;MOV SFR(FBh),#02h    Note
      DIVHU      CE FB 03         ;MOV SFR(FBh),#03h    Note
      DIVWU      CE FB 0B         ;MOV SFR(FBh),#0Bh    Note
      MACHU      CE FB 05         ;MOV SFR(FBh),#05h    Note
      MACH       CE FB 06         ;MOV SFR(FBh),#06h    Note

Others:

      "saddr.#" and "sfr.#" with #=8..15 could be implemented as "addr+1.#-8".
      "callt [nn]" can be seen as 2-byte alias for "call nnnn" (via the ROM table)

3DS I2C MCU - RL78 CPU Registers and Flags

Registers

      PC   20bit   Program Counter
      PSW  8bit    Program Status Word (flags)
      SP   16bit   Stack Pointer (bit0=always 0, bit1-15=used)
      AX   16bit   aka A:X   ;\these can be used as 16bit (eg. AX) or two 8bit
      BC   16bit   aka B:C   ; registers (eg. A and X).
      DE   16bit   aka D:E   ; all of these registers exist in 4 banks (the
      HL   16bit   aka H:L   ;/active bank is selected via "SEL RBn" opcode)
      ES   4bit    Data Bank ;-used only for PREFIX'ed opcode, otherwise bank=0Fh
      CS   4bit    Code Bank ;-MSBs of destination for JMP/CALL AX/BC/DE/HL

Note: All registers (except PC) are mapped to the SFR register area, and can be also used by accessing that memory. In case of the banked AX/BC/DE/HL registers, observe that direct memory access won't recurse the current "bank" selection (that weird feature/problem is same as for 8051 CPUs).
RL78 Memory Map

      00000h 80h    Code Vector Table                                     ;\
      00080h 40h    Code Callt Table                                      ;
      000C0h 4      Code Option byte area (4 bytes)                       ; Code
      000C4h 0Ah    Code On-chip debug security ID setting area           ; FLASH
      000CEh F32h   Code                                                  ; memory
      01000h 1000h  Code (can be hardware-swapped with 00000h..00FFFh?)   ;
      02000h 3000h  Code                                                  ;
      05000h 3000h  Code (3DS uses this area as firmware backup copy)     ;/
      08000h 8000h  Unused, FFh-filled (does NOT seem to be flash)
      10000h DD800h Unused, 00h-filled
      ED800h 2800h  ROM area (or A4h,FBh,5Ah,FAh-filled when disabled)    ;\
      EFFD0h 2      ROM data, FLASH (size-1)/100h   ;007Fh=32Kbyte        ; ROM
      EFFF8h 4      ROM code, jump vector for flash functions (c=func)    ;/
      F0000h 7E0h   Special-function registers (2nd SFRs)
      F07E0h 620h   Hidden RAM (for use by ROM) (or 00h-filled when disabled) ;-RAM
      F0E00h 200h   Mirror of RAM at FF900h     (or 00h-filled when disabled)
      F1000h 7000h  Mirror of FLASH ROM code area at 01000h (for [Fxxxxh] data)
      F8000h 78F0h  Mirror of unused FFh-filled area at 08000h
      FF8F0h 10h    Hidden RAM (for use by ROM) (or FFh-filled when disabled) ;-?
      FF900h 520h   RAM
      FFE20h C0h    RAM (C0h bytes, short-addressable)         ;short addr 20h..DFh
      FFEE0h 20h    Registers AX,BC,DE,HL (in four banks)      ;short addr E0h..FFh
      FFF00h 20h    SFRs (Port 0-15, etc.)  ;SFR addr 00h..1Fh ;short addr 00h..1Fh
      FFF20h D8h    SFRs                    ;SFR addr 20h..F7h
      FFFF8h 8      Registers SP,PSW,etc.   ;SFR addr F8h..FFh

RL78 Program Status Word (PSW aka Flags)

         S1    S2/S3
      0  CY    CY    Carry flag (0=No, 1=Carry/borrow)
      1  ISP0  ISP0  In-service Priority bit0
      2  ISP1  ISP1  In-service Priority bit1
      3  0     RBS0  Register Bank Select bit0   (RL78-S2/S3 only) (used on 3DS)
      4  AC    AC    Auxilliary Carry flag (aka carry on 4bit nibble)
      5  0     RBS1  Register Bank Select bit1   (RL78-S2/S3 only) (used on 3DS)
      6  Z     Z     Zero flag             (0=No, 1=Zero/Equal)
      7  IE    IE    Interrupt Enable flag (0=Disable, 1=Enable)

RL78 Opcode flags

      Opcode                                ZHC
      ADD/ADDC/SUB/SUBC/CMP/CMPS            XXX
      ADDW/SUBW/CMPW ;with dst<>SP          XXX
      ADDW/SUBW      ;with dst=SP           ---
      CMP0                                  X00
      AND/OR/XOR                            X--
      INC/DEC                               XX-
      INCW/DECW                             ---
      MOVS                                  X-X
      SHR/SHRW/SHL/SHLW/SAR/SARW            --X
      ROR/RORC/ROL/ROLC/ROLWC               --X
      AND1/OR1/XOR1/NOT1                    --X
      MOV1                                  ---
      MOV/XCH/ONEB/CLRB                     ---
      MOVW/XCHW/ONEW/CLRW                   ---
      MULU                                  ---
      SET1/CLR1                             ---
      CALL/CALLT/BRK/RET/PUSH/POP           ---
      BR/Bcond/SKcond/BTCLR                 ---
      SEL/NOP/DI/EI/HALT/STOP               ---
      RETI/RETB                             old

Note: Opcodes that use PSW or PSW.n or CY as destination operand do of course also affect the corresponding flags.
RL78 Conditional Opcodes
The CPU supports conditional branch/skip opcodes. Skip does skip the next opcode if the condition is true (unknown if that is any faster, especially in case of large 5-byte opcodes). Combining conditional SKx+BT/BF is possible.

      Native    Mocash
      BC  SKC   JC/JB   SKC/SKB   CY=1 (carry, unsigned below)
      BNC SKNC  JNC/JAE SKNC/SKAE CY=0 (no carry, unsigned above or equal)
      BZ  SKZ   JZ/JE   SKZ/SKE   Z=1 (zero/equal)
      BNZ SKNZ  JNZ/JNE SKNZ/SKNE Z=0 (nonzero/not equal)
      BH  SKH   JA      SKA       CY=0 and Z=0 (unsigned above/higher)
      BNH SKNH  JBE     SKBE      CY=1 or Z=1 (unsigned below or equal, not higher)
      BF        JZ                bit=0 (bit false/zero)
      BT        JNZ               bit=1 (bit true/nonzero)
      BTCLR     JNZCLR            bit=1 (bit true/nonzero, and auto-clear bit)

There are no conditions for signed overflow/less/greater. Signed positive/negative can be tested via BF/BT on result.bit7/bit15.
The skip feature could be used as prefix for making conditional opcodes, eg. "ADD.Z" could be made of "SKNZ+ADD" (to add if zero).
Stack

      PUSH/POP rp/PSW --> 2 bytes
      CALL/CALLT/RET  --> 4 bytes
      Interrupt/RETI  --> 4 bytes
      BRK/RETB        --> 4 bytes

3DS I2C MCU - RL78 SFR Registers (Special Function Registers) (I/O ports)

Datasheets
SFRs are documented in RL78 Hardware Manuals. However, the SFRs aren't 100% same for all RL78 chips. The "78K0R/KC3-L, 78K0R/KE3-L" datasheet appears to be pretty close to the 3DS hardware (aside from the F0500h-F07FFh area).
SFR List

      Addr   Access  Reset Symbol     Special Function Register (SFR)
      FFF00h R/W 1B- 00h   P0         Port data 0
      FFF01h R/W 1B- 00h   P1         Port data 1
      FFF02h R/W 1B- 00h   P2         Port data 2
      FFF03h R/W 1B- 00h   P3         Port data 3
      FFF04h R/W 1B- 00h   P4         Port data 4
      FFF05h R/W 1B- 00h   P5         Port data 5
      FFF06h R/W 1B- 00h   P6         Port data 6
      FFF07h R/W 1B- 00h   P7         Port data 7
      FFF08h R/W 1B- 00h   P8         Port data 8   (N/A)
      FFF09h R/W 1B- 00h   P9         Port data 9   (N/A)
      FFF0Ah R/W 1B- 00h   P10        Port data 10  (N/A)
      FFF0Bh R/W 1B- 00h   P11        Port data 11  (78K0R/K E3-L)
      FFF0Ch R/W 1B- Undef P12        Port data 12
      FFF0Dh R/W 1B- 00h   P13        Port data 13  (78K0R/K E3-L)
      FFF0Eh R/W 1B- 00h   P14        Port data 14
      FFF0Fh R/W 1B- 00h   P15        Port data 15  (N/A)
      FFF10h R/W -BW 0000h SDR00      Serial data 00 (TXD0/SIO00)
      FFF12h R/W -BW 0000h SDR01      Serial data 01 (RXD0/SIO01)
      FFF14h R/W -BW 0000h SDR12      Serial data 12 (TXD3/SIO30)
      FFF16h R/W -BW 0000h SDR13      Serial data 13 (RXD3/SIO31)
      FFF18h R/W --W 0000h TDR00      Timer data 00
      FFF1Ah R/W -BW 0000h TDR01(L/H) Timer data 01     (NOT L/H)
      FFF1Eh R   --W 0000h ADCR       10-bit A/D conversion result
      FFF1Fh R   -B- 00h   ADCRH      8-bit A/D conversion result
      FFF20h R/W 1B- FFh   PM0        Port mode 0
      FFF21h R/W 1B- FFh   PM1        Port mode 1
      FFF22h R/W 1B- FFh   PM2        Port mode 2
      FFF23h R/W 1B- FFh   PM3        Port mode 3
      FFF24h R/W 1B- FFh   PM4        Port mode 4
      FFF25h R/W 1B- FFh   PM5        Port mode 5
      FFF26h R/W 1B- FFh   PM6        Port mode 6
      FFF27h R/W 1B- FFh   PM7        Port mode 7
      FFF28h R/W 1B- FFh   PM8        Port mode 8  (N/A)
      FFF29h R/W 1B- FFh   PM9        Port mode 9  (N/A)
      FFF2Ah R/W 1B- FFh   PM10       Port mode 10 (N/A)
      FFF2Bh R/W 1B- FFh   PM11       Port mode 11 (78K0R/K E3-L)
      FFF2Ch R/W 1B- FFh   PM12       Port mode 12
      FFF2Dh -   --- -     PM13       Port mode 13 (N/A)
      FFF2Eh R/W 1B- FFh   PM14       Port mode 14
      FFF2Fh R/W 1B- FFh   PM15       Port mode 15 (N/A) (3DS)
      FFF30h R/W 1B- 00h   ADM0       A/D converter mode 0
      FFF31h R/W 1B- 00h   ADS        Analog input channel specification
      FFF32h R/W 1B- 00h   ADM1       A/D converter mode 1                  (N/A)
      FFF37h R/W 1B- 00h   KRM        Key return mode
      FFF38h R/W 1B- 00h   EGP0       External interrupt rising edge enable 0
      FFF39h R/W 1B- 00h   EGN0       External interrupt falling edge enable 0
      FFF3Ah R/W 1B- 00h   EGP1       External int rising edge enable 1    (E3-L)
      FFF3Bh R/W 1B- 00h   EGN1       External int falling edge enable 1   (E3-L)
      FFF3Ch R/W 1B- 00h   ISC        Input switch control register (!)
      FFF3Eh R/W 1B- 00h   TIS0       Timer input select register 0 (!)
      FFF44h R/W -BW 0000h SDR02      Serial data 02 (TXD1/SIO10)
      FFF46h R/W -BW 0000h SDR03      Serial data 03 (RXD1/SIO11)
      FFF48h R/W -BW 0000h SDR10      Serial data 10 (TXD2/SIO20)  (78K0R/K E3-L)
      FFF4Ah R/W -BW 0000h SDR11      Serial data 11 (RXD2/SIO21)  (78K0R/K E3-L)
      FFF50h R/W -B- 00h   IICA0      I2C IICA shift 0
      FFF51h R   1B- 00h   IICS0      I2C IICA status 0
      FFF52h R/W 1B- 00h   IICF0      I2C IICA flag 0
     ;FFF54h R/W -B- 00h   IICA1      I2C IICA shift 1  (N/A)
     ;FFF55h R   1B- 00h   IICS1      I2C IICA status 1 (N/A)
     ;FFF56h R/W 1B- 00h   IICF1      I2C IICA flag 1   (N/A)
      FFF64h R/W --W 0000h TDR02      Timer data 02
      FFF66h R/W -BW 0000h TDR03(L/H) Timer data 03     (NOT L/H)
      FFF68h R/W --W 0000h TDR04      Timer data 04
      FFF6Ah R/W --W 0000h TDR05      Timer data 05
      FFF6Ch R/W --W 0000h TDR06      Timer data 06
      FFF6Eh R/W --W 0000h TDR07      Timer data 07
      FFF70h R/W --W 0000h TDR10      Timer data 10     (N/A)
      FFF72h R/W -BW 0000h TDR11(L/H) Timer data 11     (N/A)
      FFF74h R/W --W 0000h TDR12      Timer data 12     (N/A)
      FFF76h R/W -BW 0000h TDR13(L/H) Timer data 13     (N/A)
      FFF78h R/W --W 0000h TDR14      Timer data 14     (N/A)
      FFF7Ah R/W --W 0000h TDR15      Timer data 15     (N/A)
      FFF7Ch R/W --W 0000h TDR16      Timer data 16     (N/A)
      FFF7Eh R/W --W 0000h TDR17      Timer data 17     (N/A)

      FFF80h                          Undoc:
      FFF81h                          Undoc:
      FFF82h                          Undoc:
      FFF83h                          Undoc:
      FFF84h                          Undoc:
      FFF85h                          Undoc:
      FFF86h                          Undoc:
      FFF87h                          Undoc:
      FFF88h                          Undoc:
      FFF89h                          Undoc: something?
      FFF8Ah                          Undoc: something?
      FFF8Bh                          Undoc: Serial TOOL0 stat/ack
      FFF8Ch                          Undoc: Serial TOOL0 control
      FFF8Dh                          Undoc: Serial TOOL0 bauds.lsb
      FFF8Eh                          Undoc: Serial TOOL0 bauds.msb
      FFF8Fh                          Undoc: Serial TOOL0 data

      FFF90h R/W --W 0000h RSUBC      Sub-count register (!)   (3DS)  ;\either
     (FFF90h)R/W --W 0FFFh ITMC       Interval timer control   (N/A)  ;/or
      FFF92h R/W -B- 00h   SEC        Second count
      FFF93h R/W -B- 00h   MIN        Minute count
      FFF94h R/W -B- 12h   HOUR       Hour count (12 AM upon reset)
      FFF95h R/W -B- 00h   WEEK       Week count (uh, week??????)
      FFF96h R/W -B- 01h   DAY        Day count
      FFF97h R/W -B- 01h   MONTH      Month count
      FFF98h R/W -B- 00h   YEAR       Year count
      FFF99h R/W -B- 00h   SUBCUD     Watch error correction
      FFF9Ah R/W -B- 00h   ALARMWM    Alarm minute
      FFF9Bh R/W -B- 12h   ALARMWH    Alarm hour
      FFF9Ch R/W -B- 00h   ALARMWW    Alarm week
      FFF9Dh R/W 1B- 00h   RTCC0      Real-time clock control 0
      FFF9Eh R/W 1B- 00h   RTCC1      Real-time clock control 1
      FFF9Fh R/W 1B- 00h   RTCC2      Real-time clock control 2 (!)
      FFFA0h R/W -B- 00h   CMC        Clock operation mode control
      FFFA1h R/W 1B- C0h   CSC        Clock operation status control
      FFFA2h R   1B- 00h   OSTC       Osc stabilization time counter status
      FFFA3h R/W -B- 07h   OSTS       Osc stabilization time select
      FFFA4h R/W 1B- 00h   CKC        System clock control
      FFFA5h R/W 1B- 00h   CKS0       Clock output select 0
      FFFA6h R/W 1B- 00h   CKS1       Clock output select 1 (N/A) (Old3DS)
      FFFA8h R   -B- Undef RESF       Reset control flag
      FFFA9h R/W 1B- 00h   LVIM       Low-Voltage detection
      FFFAAh R/W 1B- var   LVIS       Low-Voltage detection level (reset=xxh)
      FFFABh R/W -B- var   WDTE       Watchdog timer enable   (reset=1Ah/9Ah)
      FFFACh R/W -B- 00h   CRCIN      CRC input            (N/A)
      FFFB0h R/W -B- 00h   DSA0       DMA SFR address 0
      FFFB1h R/W -B- 00h   DSA1       DMA SFR address 1
      FFFB2h R/W -BW 0000h DRA0(L/H)  DMA RAM address 0
      FFFB4h R/W -BW 0000h DRA1(L/H)  DMA RAM address 1
      FFFB6h R/W -BW 0000h DBC0(L/H)  DMA byte count 0
      FFFB8h R/W -BW 0000h DBC1(L/H)  DMA byte count 1
      FFFBAh R/W 1B- 00h   DMC0       DMA mode control 0
      FFFBBh R/W 1B- 00h   DMC1       DMA mode control 1
      FFFBCh R/W 1B- 00h   DRC0       DMA operation control 0
      FFFBDh R/W 1B- 00h   DRC1       DMA operation control 1
      FFFBEh R/W 1B- 00h   BECTL      Background event control register (!)
      FFFBFh     1                    Undoc:
      FFFC0h -   --- Undef PFCMD      (used in the self programming library) (!)
      FFFC1h     1B                   Undoc:
      FFFC2h -   --- 00h   PFS        (used in the self programming library) (!)
      FFFC4h -   --- 00h   FLPMC      (used in the self programming library) (!)
      FFFC5h     1                    Undoc:
      FFFC6h      B                   Undoc:
      FFFC7h      B                   Undoc:
      FFFC8h       W                  Undoc:
      FFFCAh      B                   Undoc:
      FFFCBh      B                   Undoc:
      FFFCCh       W                  Undoc:
      FFFCEh       W                  Undoc:
      FFFD0h R/W 1BW 0000h IF2(L/H)   Interrupt request flag 2
      FFFD2h R/W 1BW 00h   IF3(L)     Interrupt request flag 3L       (N/A)
      FFFD4h R/W 1BW FFFFh MK2(L/H)   Interrupt mask flag 2
      FFFD6h R/W 1BW FFh   MK3(L)     Interrupt mask flag 3L          (N/A)
      FFFD8h R/W 1BW FFFFh PR02(L/H)  Priority specification flag 02
      FFFDAh R/W 1BW FFh   PR03(L)    Priority specification flag 03L (N/A)
      FFFDCh R/W 1BW FFFFh PR12(L/H)  Priority specification flag 12
      FFFDEh R/W 1BW FFh   PR13(L)    Priority specification flag 13L (N/A)
      FFFE0h R/W 1BW 0000h IF0(L/H)   Interrupt request flag 0
      FFFE2h R/W 1BW 0000h IF1(L/H)   Interrupt request flag 1
      FFFE4h R/W 1BW FFFFh MK0(L/H)   Interrupt mask flag 0
      FFFE6h R/W 1BW FFFFh MK1(L/H)   Interrupt mask flag 1
      FFFE8h R/W 1BW FFFFh PR00(L/H)  Priority specification flag 00
      FFFEAh R/W 1BW FFFFh PR01(L/H)  Priority specification flag 01
      FFFECh R/W 1BW FFFFh PR10(L/H)  Priority specification flag 10
      FFFEEh R/W 1BW FFFFh PR11(L/H)  Priority specification flag 11
      FFFF0h R/W --W 0000h MDAL       Multiplication/division data A (L) (MULA)
      FFFF2h R/W --W 0000h MDAH       Multiplication/division data A (H) (MULB)
      FFFF4h R/W --W 0000h MDBH       Multiplication/division data B (H) (MULOH)
      FFFF6h R/W --W 0000h MDBL       Multiplication/division data B (L) (MULOL)
      FFFF8h ??? ??? ????h SP(L/H)    CPU Stack Pointer                 ;\
      FFFFAh R/W ??? ??h   PSW        CPU Program Status Word           ;
      FFFFBh W   -B- --    -          CPU Reserve (for MUL/DIV opcodes) ; Fixed
      FFFFCh ??? ??? 00h   CS         CPU Program Counter Bank          ; SFRs
      FFFFDh ??? ??? ??h   ES         CPU Data Bank                     ;
      FFFFEh R/W 1B- 00h   PMC        CPU Processor mode control        ;
      FFFFFh ??? ??? ??h   MEM        CPU ... whatever?                 ;/

Extended SFR (2nd SFR) List

      F0010h R/W 1B- 00h   ADM2      A/D converter mode 2                     (N/A)
      F0011h R/W -B- FFh   ADUL      A/D result comparison upper limit setting(N/A)
      F0012h R/W -B- 00h   ADLL      A/D result comparison lower limit setting(N/A)
      F0013h R/W -B- 00h   ADTES     A/D test                                 (N/A)
      F0017h R/W -B- 10h   ADPC      A/D port configuration register (!)
      F0030h R/W 1B- 00h   PU0       Pull-up resistor option 0        ;\
      F0031h R/W 1B- 00h   PU1       Pull-up resistor option 1        ;
      F0032h -   --- -     PU2       Pull-up resistor option 2  (N/A) ;
      F0033h R/W 1B- 00h   PU3       Pull-up resistor option 3        ;
      F0034h R/W 1B- 01h   PU4       Pull-up resistor option 4        ;
      F0035h R/W 1B- 00h   PU5       Pull-up resistor option 5        ;
      F0036h R/W 1B- 00h   PU6       Pull-up resistor option 6  (N/A) ;
      F0037h R/W 1B- 00h   PU7       Pull-up resistor option 7        ;
      F0038h R/W 1B- 00h   PU8       Pull-up resistor option 8  (N/A) ;
      F0039h R/W 1B- 00h   PU9       Pull-up resistor option 9  (N/A) ;
      F003Ah R/W 1B- 00h   PU10      Pull-up resistor option 10 (N/A) ;
      F003Bh R/W 1B- 00h   PU11      Pull-up resistor option 11 (78K0R/K E3-L)
      F003Ch R/W 1B- 00h   PU12      Pull-up resistor option 12       ;
      F003Dh -   --- -     PU13      Pull-up resistor option 13 (N/A) ;
      F003Eh R/W 1B- 00h   PU14      Pull-up resistor option 14       ;
      F003Fh -   --- -     PU15      Pull-up resistor option 15 (N/A) ;/
      F0040h R/W 1B- 00h   PIM0      Port input mode 0                ;\
      F0041h R/W 1B- 00h   PIM1      Port input mode 1                ;
      F0042h -   --- -     PIM2      Port input mode 2  (N/A)         ;
      F0043h -   --- -     PIM3      Port input mode 3  (N/A)         ;
      F0044h R/W 1B- 00h   PIM4      Port input mode 4  (N/A)         ;
      F0045h R/W 1B- 00h   PIM5      Port input mode 5  (N/A)         ;
      F0046h -   --- -     PIM6      Port input mode 6  (N/A)         ;
      F0047h -   --- -     PIM7      Port input mode 7  (N/A)         ;
      F0048h R/W 1B- 00h   PIM8      Port input mode 8  (N/A)         ;
      F0049h -   --- -     PIM9      Port input mode 9  (N/A)         ;
      F004Ah -   --- -     PIM10     Port input mode 10 (N/A)         ;
      F004Bh -   --- -     PIM11     Port input mode 11 (N/A)         ;
      F004Ch -   --- -     PIM12     Port input mode 12 (N/A)         ;
      F004Dh -   --- -     PIM13     Port input mode 13 (N/A)         ;
      F004Eh R/W 1B- 00h   PIM14     Port input mode 14 (78K0R/K E3-L);
      F004Fh -   --- -     PIM15     Port input mode 15 (N/A)         ;/
      F0050h R/W 1B- 00h   POM0      Port output mode 0               ;\
      F0051h R/W 1B- 00h   POM1      Port output mode 1               ;
      F0052h -   --- -     POM2      Port output mode 2  (N/A)        ;
      F0053h -   --- -     POM3      Port output mode 3  (N/A?) (3DS!);
      F0054h R/W 1B- 00h   POM4      Port output mode 4  (N/A)        ;
      F0055h R/W 1B- 00h   POM5      Port output mode 5  (N/A)        ;
      F0056h -   --- -     POM6      Port output mode 6  (N/A)        ;
      F0057h R/W 1B- 00h   POM7      Port output mode 7  (N/A)        ;
      F0058h R/W 1B- 00h   POM8      Port output mode 8  (N/A)        ;
      F0059h R/W 1B- 00h   POM9      Port output mode 9  (N/A)        ;
      F005Ah -   --- -     POM10     Port output mode 10 (N/A)        ;
      F005Bh -   --- -     POM11     Port output mode 11 (N/A)        ;
      F005Ch -   --- -     POM12     Port output mode 12 (N/A)        ;
      F005Dh -   --- -     POM13     Port output mode 13 (N/A)        ;
      F005Eh R/W 1B- 00h   POM14     Port output mode 14 (78K0R/K E3-L);
      F005Fh -   --- -     POM15     Port output mode 15 (N/A)        ;/

      F0060h R/W 1B- 00h   NFEN0     Noise filter enable 0 (!)               ;\(!)
      F0061h R/W 1B- 00h   NFEN1     Noise filter enable 1 (!)               ;/

     ;F0060h R/W 1B- FFh   PMC0      Port mode control 0              ;\     ;\
     ;F0061h -   --- -     PMC1      Port mode control 1  (N/A)       ;      ;
     ;F0062h -   --- -     PMC2      Port mode control 2  (N/A)       ;      ;
     ;F0063h R/W 1B- FFh   PMC3      Port mode control 3              ;      ;
     ;F0064h -   --- -     PMC4      Port mode control 4  (N/A)       ;      ;
     ;F0065h -   --- -     PMC5      Port mode control 5  (N/A)       ;      ;
     ;F0066h -   --- -     PMC6      Port mode control 6  (N/A)       ;      ;
     ;F0067h -   --- -     PMC7      Port mode control 7  (N/A)       ;      ; N/A
     ;F0068h -   --- -     PMC8      Port mode control 8  (N/A)       ;      ; !!!
     ;F0069h -   --- -     PMC9      Port mode control 9  (N/A)       ;      ;
     ;F006Ah R/W 1B- FFh   PMC10     Port mode control 10             ;      ;
     ;F006Bh R/W 1B- FFh   PMC11     Port mode control 11             ;      ;
     ;F006Ch R/W 1B- FFh   PMC12     Port mode control 12             ;      ;
     ;F006Dh -   --- -     PMC13     Port mode control 13 (N/A)       ;      ;
     ;F006Eh R/W 1B- FFh   PMC14     Port mode control 14             ;      ;
     ;F006Fh -   --- -     PMC15     Port mode control 15 (N/A)       ;/     ;
     ;F0070h R/W 1B- 00h   NFEN0     Noise filter enable 0                   ;
     ;F0071h R/W 1B- 00h   NFEN1     Noise filter enable 1                   ;
     ;F0072h R/W 1B- 00h   NFEN2     Noise filter enable 2                   ;
     ;F0073h R/W 1B- 00h   ISC       Input switch control                    ;
     ;F0074h R/W -B- 00h   TIS0      Timer input select 0                    ;
     ;F0076h R/W -B- 00h   ADPC      A/D port configuration                  ;
     ;F0077h R/W -B- 00h   PIOR      Peripheral I/O redirection              ;
     ;F0078h R/W -B- 00h   IAWCTL    Invalid memory access detection control ;
     ;F007Dh R/W 1B- 00h   GDIDIS    Global digital input disable            ;
     ;F0090h R/W 1B- 00h   DFLCTL    Data flash control                      ;
     ;F00A0h R/W -B- opt.  HIOTRM    High-speed on-chip oscillator trimming  ;
     ;F00A8h R/W -B- opt.  HOCODIV   High-speed on-chip oscillator frequency ;/

      F00C0h                         ?? flash?        (!)(!)(!)          ;-3DS

      F00C0h      B                   Undoc:
      F00C1h      B                   Undoc:
      F00C2h       W                  Undoc:
      F00C4h       W                  Undoc:
      F00C8h       W                  Undoc:

      F00E0h R/W --W 0000h MDCL      Multiplication/division data C (L)
      F00E2h R/W --W 0000h MDCH      Multiplication/division data C (H)
      F00E8h R/W 1B- 00h   MDUC      Multiplication/division control
      F00F0h R/W 1B- 00h   PER0      Peripheral enable 0
      F00F2h                         Timer? (!)(!)(!)                    ;-3DS
      F00F3h R/W -B- 00h   OSMC      Subsystem clock supply mode control
      F00F4h R/W -B- 00h   RMC       Regulator mode control register (!)
      F00F5h R/W 1B- 00h   RPECTL    RAM parity error control (!)
      F00F6h R/W 1B- 00h   DSCCTL    20 MHz internal high-speed osc. control (!)
      F00FEh R   -B- Undef BCDADJ    BCD adjust result
      F0100h R   -BW 0000h SSR00(L)  Serial status 00
      F0102h R   -BW 0000h SSR01(L)  Serial status 01
      F0104h R   -BW 0000h SSR02(L)  Serial status 02
      F0106h R   -BW 0000h SSR03(L)  Serial status 03
      F0108h R/W -BW 0000h SIR00(L)  Serial flag clear trigger 00
      F010Ah R/W -BW 0000h SIR01(L)  Serial flag clear trigger 01
      F010Ch R/W -BW 0000h SIR02(L)  Serial flag clear trigger 02
      F010Eh R/W -BW 0000h SIR03(L)  Serial flag clear trigger 03
      F0110h R/W --W 0020h SMR00     Serial mode 00
      F0112h R/W --W 0020h SMR01     Serial mode 01
      F0114h R/W --W 0020h SMR02     Serial mode 02
      F0116h R/W --W 0020h SMR03     Serial mode 03
      F0118h R/W --W 0087h SCR00     Serial communication operation setting 00
      F011Ah R/W --W 0087h SCR01     Serial communication operation setting 01
      F011Ch R/W --W 0087h SCR02     Serial communication operation setting 02
      F011Eh R/W --W 0087h SCR03     Serial communication operation setting 03
      F0120h R   1BW 0000h SE0(L)    Serial channel enable status 0
      F0122h R/W 1BW 0000h SS0(L)    Serial channel start 0
      F0124h R/W 1BW 0000h ST0(L)    Serial channel stop 0
      F0126h R/W -BW 0000h SPS0(L)   Serial clock select 0
      F0128h R/W --W 0F0Fh SO0       Serial output 0
      F012Ah R/W 1BW 0000h SOE0(L)   Serial output enable 0
      F0134h R/W -BW 0000h SOL0(L)   Serial output level 0
      F0138h R/W -BW 0000h SSC0(L)   Serial standby control 0 (N/A)
      F0140h R   -BW 0000h SSR10(L)  Serial status 10 (78K0R/K E3-L)
      F0142h R   -BW 0000h SSR11(L)  Serial status 11 (78K0R/K E3-L)
      F0144h R   -BW 0000h SSR12(L)  Serial status 12
      F0146h R   -BW 0000h SSR13(L)  Serial status 13
      F0148h R/W -BW 0000h SIR10(L)  Serial flag clear trigger 10 (78K0R/K E3-L)
      F014Ah R/W -BW 0000h SIR11(L)  Serial flag clear trigger 11 (78K0R/K E3-L)
      F014Ch R/W -BW 0000h SIR12(L)  Serial flag clear trigger 12
      F014Eh R/W -BW 0000h SIR13(L)  Serial flag clear trigger 13
      F0150h R/W --W 0020h SMR10     Serial mode 10 (78K0R/K E3-L)
      F0152h R/W --W 0020h SMR11     Serial mode 11 (78K0R/K E3-L)
      F0154h R/W --W 0020h SMR12     Serial mode 12
      F0156h R/W --W 0020h SMR13     Serial mode 13
      F0158h R/W --W 0087h SCR10     Serial communication operation setting 10 (E3)
      F015Ah R/W --W 0087h SCR11     Serial communication operation setting 11 (E3)
      F015Ch R/W --W 0087h SCR12     Serial communication operation setting 12
      F015Eh R/W --W 0087h SCR13     Serial communication operation setting 13
      F0160h R   1BW 0000h SE1(L)    Serial channel enable status 1
      F0162h R/W 1BW 0000h SS1(L)    Serial channel start 1
      F0164h R/W 1BW 0000h ST1(L)    Serial channel stop 1
      F0166h R/W -BW 0000h SPS1(L)   Serial clock select 1
      F0168h R/W --W 0F0Fh SO1       Serial output 1
      F016Ah R/W 1BW 0000h SOE1(L)   Serial output enable 1
      F0174h R/W -BW 0000h SOL1(L)   Serial output level 1
      F0178h R/W -BW 0000h SSC1(L)   Serial standby control 1 (N/A)
      ...                            - - -       ?
      F0180h R   --W FFFFh TCR00     Timer counter 00
      F0182h R   --W FFFFh TCR01     Timer counter 01
      F0184h R   --W FFFFh TCR02     Timer counter 02
      F0186h R   --W FFFFh TCR03     Timer counter 03
      F0188h R   --W FFFFh TCR04     Timer counter 04
      F018Ah R   --W FFFFh TCR05     Timer counter 05
      F018Ch R   --W FFFFh TCR06     Timer counter 06
      F018Eh R   --W FFFFh TCR07     Timer counter 07
      F0190h R/W --W 0000h TMR00     Timer mode 00
      F0192h R/W --W 0000h TMR01     Timer mode 01
      F0194h R/W --W 0000h TMR02     Timer mode 02
      F0196h R/W --W 0000h TMR03     Timer mode 03
      F0198h R/W --W 0000h TMR04     Timer mode 04
      F019Ah R/W --W 0000h TMR05     Timer mode 05
      F019Ch R/W --W 0000h TMR06     Timer mode 06
      F019Eh R/W --W 0000h TMR07     Timer mode 07
      F01A0h R   -BW 0000h TSR00(L)  Timer status 00
      F01A2h R   -BW 0000h TSR01(L)  Timer status 01
      F01A4h R   -BW 0000h TSR02(L)  Timer status 02
      F01A6h R   -BW 0000h TSR03(L)  Timer status 03
      F01A8h R   -BW 0000h TSR04(L)  Timer status 04
      F01AAh R   -BW 0000h TSR05(L)  Timer status 05
      F01ACh R   -BW 0000h TSR06(L)  Timer status 06
      F01AEh R   -BW 0000h TSR07(L)  Timer status 07
      F01B0h R   1BW 0000h TE0(L)    Timer channel enable status 0
      F01B2h R/W 1BW 0000h TS0(L)    Timer channel start 0
      F01B4h R/W 1BW 0000h TT0(L)    Timer channel stop 0
      F01B6h R/W --W 0000h TPS0      Timer clock select 0
      F01B8h R/W -BW 0000h TO0(L)    Timer output 0
      F01BAh R/W 1BW 0000h TOE0(L)   Timer output enable 0
      F01BCh R/W -BW 0000h TOL0(L)   Timer output level 0
      F01BEh R/W -BW 0000h TOM0(L)   Timer output mode 0
     ;F01C0h R   --W FFFFh TCR10     Timer counter 10               ;\
     ;F01C2h R   --W FFFFh TCR11     Timer counter 11               ;
     ;F01C4h R   --W FFFFh TCR12     Timer counter 12               ;
     ;F01C6h R   --W FFFFh TCR13     Timer counter 13               ;
     ;F01C8h R   --W FFFFh TCR14     Timer counter 14               ;
     ;F01CAh R   --W FFFFh TCR15     Timer counter 15               ;
     ;F01CCh R   --W FFFFh TCR16     Timer counter 16               ;
     ;F01CEh R   --W FFFFh TCR17     Timer counter 17               ;
     ;F01D0h R/W --W 0000h TMR10     Timer mode 10                  ;
     ;F01D2h R/W --W 0000h TMR11     Timer mode 11                  ;
     ;F01D4h R/W --W 0000h TMR12     Timer mode 12                  ; N/A !!!
     ;F01D6h R/W --W 0000h TMR13     Timer mode 13                  ;
     ;F01D8h R/W --W 0000h TMR14     Timer mode 14                  ;
     ;F01DAh R/W --W 0000h TMR15     Timer mode 15                  ;
     ;F01DCh R/W --W 0000h TMR16     Timer mode 16                  ;
     ;F01DEh R/W --W 0000h TMR17     Timer mode 17                  ;
     ;F01E0h R   -BW 0000h TSR10(L)  Timer status 10                ;
     ;F01E2h R   -BW 0000h TSR11(L)  Timer status 11                ;
     ;F01E4h R   -BW 0000h TSR12(L)  Timer status 12                ;
     ;F01E6h R   -BW 0000h TSR13(L)  Timer status 13                ;
     ;F01E8h R   -BW 0000h TSR14(L)  Timer status 14                ;
     ;F01EAh R   -BW 0000h TSR15(L)  Timer status 15                ;
     ;F01ECh R   -BW 0000h TSR16(L)  Timer status 16                ;
     ;F01EEh R   -BW 0000h TSR17(L)  Timer status 17                ;
     ;F01F0h R   1BW 0000h TE1(L)    Timer channel enable status 1  ;
     ;F01F2h R/W 1BW 0000h TS1(L)    Timer channel start 1          ;
     ;F01F4h R/W 1BW 0000h TT1(L)    Timer channel stop 1           ;
     ;F01F6h R/W --W 0000h TPS1      Timer clock select 1           ;
     ;F01F8h R/W -BW 0000h TO1(L)    Timer output 1                 ;
     ;F01FAh R/W 1BW 0000h TOE1(L)   Timer output enable 1          ;
     ;F01FCh R/W -BW 0000h TOL1(L)   Timer output level 1           ;
     ;F01FEh R/W -BW 0000h TOM1(L)   Timer output mode 1            ;
     ;F0200h R/W -B- 00h   DSA2      DMA SFR address 2              ;
     ;F0201h R/W -B- 00h   DSA3      DMA SFR address 3              ;
     ;F0202h R/W -BW 0000h DRA2(L/H) DMA RAM address 2              ;
     ;F0204h R/W -BW 0000h DRA3(L/H) DMA RAM address 3              ;
     ;F0206h R/W -BW 0000h DBC2(L/H) DMA byte count 2               ;
     ;F0208h R/W -BW 0000h DBC3(L/H) DMA byte count 3               ;
     ;F020Ah R/W 1B- 00h   DMC2      DMA mode control 2             ;
     ;F020Bh R/W 1B- 00h   DMC3      DMA mode control 3             ;
     ;F020Ch R/W 1B- 00h   DRC2      DMA operation control 2        ;
     ;F020Dh R/W 1B- 00h   DRC3      DMA operation control 3        ;/
      F0230h R/W 1B- 00h   IICCTL00  I2C IICA control 00
      F0231h R/W 1B- 00h   IICCTL01  I2C IICA control 01
      F0232h R/W -B- FFh   IICWL0    I2C IICA low-level width setting 0
      F0233h R/W -B- FFh   IICWH0    I2C IICA high-level width setting 0
      F0234h R/W -B- 00h   SVA0      I2C Slave address 0
     ;F0238h R/W 1B- 00h   IICCTL10  I2C IICA control 10                  (N/A)
     ;F0239h R/W 1B- 00h   IICCTL11  I2C IICA control 11                  (N/A)
     ;F023Ah R/W -B- FFh   IICWL1    I2C IICA low-level width setting 1   (N/A)
     ;F023Bh R/W -B- FFh   IICWH1    I2C IICA high-level width setting 1  (N/A)
     ;F023Ch R/W -B- 00h   SVA1      I2C Slave address 1                  (N/A)
     ;F02F0h R/W 1B- 00h   CRC0CTL   Flash memory CRC control          (N/A)
     ;F02F2h R/W --W 0000h PGCRCL    Flash memory CRC operation result (N/A)
     ;F02FAh R/W --W 0000h CRCD      CRC data                          (N/A)
     For 78K0R...
      F0540h..   ..  ..    UF0..     UF0 stuff.. etc.. (not present in 3DS)
     Below are 3DS specific...
      F0501h     ?   ?               ??   Peripheral enable 1 for I2C ?  ;-3DS
      F0510h     ?   ?               Port data X ?                       ;\
      F0511h     ?   ?               Port mode X                         ; 3DS
      F0512h     ?   ?               Pull-up resistor option X           ;/
      F0538h     ?   ?               ??                                  ;-3DS
      F0540h R/W -B- 00h   IICA1     I2C IICA shift 1                    ;\
      F0541h R   1B- 00h   IICS1     I2C IICA status 1                   ; 3DS
      F0542h R/W 1B- 00h   IICF1     I2C IICA flag 1                     ;/
      F0550h R/W 1B- 00h   IICCTL10  I2C IICA control 10                 ;\
      F0551h R/W 1B- 00h   IICCTL11  I2C IICA control 11                 ;
      F0552h R/W -B- FFh   IICWL1    I2C IICA low-level width setting 1  ; 3DS
      F0553h R/W -B- FFh   IICWH1    I2C IICA high-level width setting 1 ;
      F0554h R/W -B- 00h   SVA1      I2C Slave address 1                 ;/

      F0746h      B                   Undoc:                                  ;-??
      F07E0h       W                  Undoc: Saved AX               ;\        ;\
      F07E2h       W                  Undoc: Saved BC               ;         ;
      F07E4h       W                  Undoc: Saved DE               ; debug   ; RAM
      F07E6h       W                  Undoc: Saved HL               ; stack?  ;
      F07E8h       W                  Undoc: Saved pop (maybe PSW?) ;         ;
      F07EAh      B                   Undoc: Saved CS               ;         ;
      F07EBh      B                   Undoc: Saved ES               ;/        ;
      F07ECh      B                   Undoc: Security okay flag (55h=yes)     ;
      F07EDh      B                   Undoc: Saved A ?                        ;
      F07EEh      B                   Undoc: Reply value ?                    ;
      F07F0h      B                   Undoc: RET opcode (or custom vector)    ;
                                                                              ;
      F0800h R/W  B  ?               FLASH related                       ;\   ;
      F0801h   W  B  ?               FLASH related                       ;    ;
      F0802h   W  B  ?               FLASH related                       ; 3DS;
      F0803h   W  B  ?               FLASH related                       ;    ;
      F0804h R/W  BW ?               FLASH related address?              ;    ;
      F0806h R/W  B  ?               FLASH related                       ;/   ;/

CPU Register Banks & short-addressable RAM

      FFE20h R/W 1BW ??    RAM[C0h]  (can be accessed with "short" address)
      FFEE0h R/W 1BW ??    AX3(X3/A3) AX Bank 3 aka RP0(3) aka R0(3)/R1(3) ;\
      FFEE2h R/W 1BW ??    BC3(C3/B3) BC Bank 3 aka RP1(3) aka R2(3)/R3(3) ; Bank 3
      FFEE4h R/W 1BW ??    DE3(E3/D3) DE Bank 3 aka RP2(3) aka R4(3)/R5(3) ;
      FFEE6h R/W 1BW ??    HL3(L3/H3) HL Bank 3 aka RP3(3) aka R6(3)/R7(3) ;/
      FFEE8h R/W 1BW ??    AX2(X2/A2) AX Bank 2 aka RP0(2) aka R0(2)/R1(2) ;\
      FFEEAh R/W 1BW ??    BC2(C2/B2) BC Bank 2 aka RP1(2) aka R2(2)/R3(2) ; Bank 2
      FFEECh R/W 1BW ??    DE2(E2/D2) DE Bank 2 aka RP2(2) aka R4(2)/R5(2) ;
      FFEEEh R/W 1BW ??    HL2(L2/H2) HL Bank 2 aka RP3(2) aka R6(2)/R7(2) ;/
      FFEF0h R/W 1BW ??    AX1(X1/A1) AX Bank 1 aka RP0(1) aka R0(1)/R1(1) ;\
      FFEF2h R/W 1BW ??    BC1(C1/B1) BC Bank 1 aka RP1(1) aka R2(1)/R3(1) ; Bank 1
      FFEF4h R/W 1BW ??    DE1(E1/D1) DE Bank 1 aka RP2(1) aka R4(1)/R5(1) ;
      FFEF6h R/W 1BW ??    HL1(L1/H1) HL Bank 1 aka RP3(1) aka R6(1)/R7(1) ;/
      FFEF8h R/W 1BW ??    AX0(X0/A0) AX Bank 0 aka RP0(0) aka R0(0)/R1(0) ;\
      FFEFAh R/W 1BW ??    BC0(C0/B0) BC Bank 0 aka RP1(0) aka R2(0)/R3(0) ; Bank 0
      FFEFCh R/W 1BW ??    DE0(E0/D0) DE Bank 0 aka RP2(0) aka R4(0)/R5(0) ;
      FFEFEh R/W 1BW ??    HL0(L0/H0) HL Bank 0 aka RP3(0) aka R6(0)/R7(0) ;/

The "1BW" column indicates support for Bit/Byte/Word access.
Words with (L) or (L/H) symbol suffix can be alternately accessed as low and/or high byte.

3DS I2C MCU - RL78 Misc

Overlapping

      ADDW AX,saddrp   can also be used for first some SFR's FFF00..FFF1F
      CLRB saddr       can also be used for first some SFR's FFF00..FFF1F
      addr16           can be used for further SFRs          FFF20..FFFFF
      SFR_SP/PSW/ES   can be used as alias for SP/PSW/ES
      SFR_AX/BC/DE/HL can be used as alias for AX/BC/DE/HL - but banked!
      SFR_CS    ... can be manually changed BEFORE JMP/CALL AX to make FAR-JMP... ?

Nocash Syntax

      Native                      Nocash
      CLRB/CLRW/CMP0 op           MOV/MOVW/CMP op,0
      ONEB/ONEW op                MOV/MOVW op,1
      ADDC/SUBC/ROLC/RORC/ROLWC   ADC/SBC/RCL/RCR/RCRW/RCLW
      BR/BF/BT/Bcond/BTCLR        JMP/JZ/JNZ/Jcond/JNZCLR
      CALLT                       CALL
      MULU X                      MULU AX,A,X    ;optional alias

     @@def Vbyte            #byte
     @@def Vword            #word
     @@def sfr              sfr        SFR name aka FFF00h..FFFFFh
     @@def sfrp             sfrp       16-bit-manipulatable SFR name (even address)
     @@def saddr            saddr      8bit data addr at FFE20h to FFF1Fh
     @@def saddrp           saddrp     same as saddr, but even-address only
     @@def $addr20          $addr20    probably 8bit reljump
     @@def $Xaddr20         $!addr20   probably 16bit reljump
     @@def XXaddr20_code    !!addr20   20bit jumpdest (3 bytes) (CALL/BR) to CS=x
     @@def Xaddr16_code     !addr16    16bit jumpdest (2 bytes) (CALL/BR) to CS=0!
     @@def Xaddr16          !addr16    16bit data addr                    at ES=F
     @@def IhlI             [HL]           ;[HL]        ;\
     @@def IdeI             [DE]           ;[DE]        ; maybe can also use ES:?
     @@def Ihl_bI           [HL+B]         ;[HL+B]      ;
     @@def Ihl_cI           [HL+C]         ;[HL+C]      ;/
     @@def wordIbcI         word[BC]       ;[BC+nnnn]   ;\
     @@def wordIbI          word[B]        ;[B+nnnn]    ;
     @@def wordIcI          word[C]        ;[C+nnnn]    ; can use ES:
     @@def Ihl_byteI        [HL+byte]      ;[HL+nn]     ;
     @@def Ide_byteI        [DE+byte]      ;[DE+nn]     ;/
     @@def Isp_byteI        [SP+byte]      ;[SP+nn]     ;\shouldn't/can't use ES:?
     @@def I00nnI           [00nn]         ;[000nn]     ;/

Caution: 16bit MOVW/ADDW/etc with memory operand must use even addresses (this is documented only for [sfrp] and [saddrp], but does also apply for [nnnn], which does actually read/write memory at [nnnn and FFFEh]).
Identifier Description

      ?  [HL + byte], [DE + byte], [SP + byte] (only the space from F0000H
          to FFFFFH is specifiable)
      ?  word[B], word[C] (only the space from F0000H to FFFFFH is specifiable)
      ?  word[BC] (only the space from F0000H to FFFFFH is specifiable)
      ?  ES:[HL + byte], ES:[DE + byte] (higher 4-bit addresses are specified by
          the ES register)
      ?  ES:word[B], ES:word[C] (higher 4-bit addresses are specified by
          the ES register)
      ?  ES:word[BC] (higher 4-bit addresses are specified by the ES register)

MCU-FIRM

      00001F02 MCU    v0, v1026, v2048, v3072, v4102, v5122, v6145, v7168, v8192
      20001F02 New_3DS MCU            v8192, v9216(New2DSXL)
      00001F03 SAFE_MODE MCU          v0
      20001F03 New_3DS SAFE_MODE MCU  v9217

RL78/G13 - Memory Map (R5F100xA, R5F101xA (x = 6 to 8, A to C, E to G))

      00000h Boot Cluster 0
      01000h Boot Cluster 1     ;<-- hence the gap

3DS I2C Gyroscope (old version)

CAUTION: This is for a reportedly existing gyroscope that doesn't actually exist, at least not in New3DS. New3DS returns only FFh's when trying to read below registers.
GYRO Register Map - InvenSense ITG-3200 gyroscope

      Hex     Register Name R/W
      00h     WHO_AM_I      R/W Device ID (aka Who Am I)
      15h     SMPLRT_DIV    R/W Sample Rate Divider (reset=00h)
      16h     DLPF_FS       R/W Low Pass Filter and Full Scale Config (reset=00h)
      17h     INT_CFG       R/W Interrupt Configuration (reset=00h)
      1Ah     INT_STATUS    R   Interrupt Status (reset=00h)
      1Bh/1Ch TEMP_OUT_H/L  R   signed 16bit Temperature data (R)
      1Dh/1Eh GYRO_XOUT_H/L R   signed 16bit Gyro X output data (R)
      1Fh/20h GYRO_YOUT_H/L R   signed 16bit Gyro Y output data (R)
      21h/22h GYRO_ZOUT_H/L R   signed 16bit Gyro Y output data (R)
      3Eh     PWR_MGM       R/W Power Management (reset=00h)
      xxh-FFh Undocumented (unknown)

Note: The 16bit H/L values are in BIG-ENDIAN format.
Register Description
The register space allows single-byte reads and writes, as well as burst reads and writes. When performing burst reads or writes, the memory pointer will increment until reading or writing is terminated by the master, or until the memory pointer reaches "certain reserved registers between 21h and 3Ch" (uh, that would include GYRO_ZOUT at 21h and/or 22h?).
Note that any bit that is not defined should be set to zero.
GYRO[00h] - WHO_AM_I - Device ID (R/W)

      0    Reserved ("may be 0 or 1") (maybe ID.bit1, maybe R/W, or what?)    (?)
      1-6  I2C Device ID bit2-7 (initially 34h on power-up, aka D0h/4)        (R/W)
      7    Reserved ("should be 0")                                           (?)

Contains the upper 6bit of the 8bit I2C Device ID, can be used for detection, the value is also write-able and can be changed after power-on.
GYRO[15h] - SMPLRT_DIV - Sample Rate Divider (R/W)

      0-7  Sample Rate Divider (00h..FFh=Divide by 1..100h) (initially 00h)

The gyros outputs are sampled internally at either 1kHz or 8kHz, determined by the DLPF_CFG setting (see register 22). This sampling is then filtered digitally and delivered into the sensor registers after the number of cycles determined by this register. The sample rate is given by the following formula:

      Fsample = Finternal / (divider+1)   ;where Finternal is either 1kHz or 8kHz

As an example, if the internal sampling is at 1kHz, then setting this register to 7 would give the following:

      Fsample = 1kHz / (7 + 1) = 125Hz, or 8ms per sample

GYRO[16h] - DLPF_FS - Low Pass Filter and Full Scale Config (R/W)

      0-2  DLPF_CFG  Digital low pass filter bandwidth & internal sample rate
      3-4  FS_SEL    Full scale selection for gyro sensor data
      5-7  Reserved (should be 0)

FS_SEL Gyro Full-Scale Range:

      0 Reserved (despite of being power-up default)
      1 Reserved
      2 Reserved
      3 +/-2000ø/sec (this should be used)

DLPF_CFG, Low Pass Filter Bandwidth, Internal Sample Rate:

      0 Internal Sample Rate=8kHz, Low Pass Filter Bandwidth=256Hz
      1 Internal Sample Rate=1kHz, Low Pass Filter Bandwidth=188Hz
      2 Internal Sample Rate=1kHz, Low Pass Filter Bandwidth=98Hz
      3 Internal Sample Rate=1kHz, Low Pass Filter Bandwidth=42Hz
      4 Internal Sample Rate=1kHz, Low Pass Filter Bandwidth=20Hz
      5 Internal Sample Rate=1kHz, Low Pass Filter Bandwidth=10Hz
      6 Internal Sample Rate=1kHz, Low Pass Filter Bandwidth=5Hz
      7 Reserved

GYRO[17h] - Interrupt Enable and INT Pin Configuration (R/W)

      0  Enable interrupt when new sample data is available           (1=Enable)
      1  -
      2  Enable interrupt when PLL ready ;after changing clock source (1=Enable)
      3  -
      4  Latch clear method (0=Status register read only, 1=Any register read);\
      5  Latch mode         (0=50us pulse, 1=latch until interrupt is cleared); INT
      6  Drive type for INT output pin  (0=push-pull, 1=open drain)           ; pin
      7  Logic level for INT output pin (0=active high, 1=active low)         ;/

Unknown what the PLL ready IRQ is good for, maybe the whole I2C bus becomes unstable/inactive and shouldn't be used until receiving the IRQ?
GYRO[1Ah] - Interrupt Status (R)

      0   New sample data is ready          (0=No, 1=Yes/IRQ)
      1   -
      2   PLL clock source change ready     (0=No, 1=Yes/IRQ)
      3-7 -

If the interrupt is not enabled, the associated status bit will NOT get set!
Interrupt Status bits are cleared after reading GYRO[1Ah] (or optionally, if GYRO[17h].bit4=1, after reading any GYRO[xxh] register).
GYRO[1Bh/1Ch] - TEMP_OUT_H/L signed 16bit Temperature data (R)
GYRO[1Dh/1Eh] - GYRO_XOUT_H/L signed 16bit Gyro X output data (R)
GYRO[1Fh/20h] - GYRO_YOUT_H/L signed 16bit Gyro Y output data (R)
GYRO[21h/22h] - GYRO_ZOUT_H/L signed 16bit Gyro Y output data (R)
Sensor Registers. These values can be read at any time; however it is best to use the interrupt function to determine when new data is available.
GYRO[3Eh] - Power Management (R/W)

      0-2 CLK_SEL  Select device clock source  (see below)
      3   STBY_ZG  Gyro Z standby mode  (0=Normal, 1=Standby)  ;\eg. disable
      4   STBY_YG  Gyro Y standby mode  (0=Normal, 1=Standby)  ; unused axis
      5   STBY_XG  Gyro X standby mode  (0=Normal, 1=Standby)  ;/to save power
      6   SLEEP    Enable low power sleep mode (0=Normal, 1=Very low power sleep)
      7   H_RESET  Reset device and internal registers to power-up-default settings

The CLK_SEL setting determines the device clock source as follows:

      0 Internal oscillator (default on power-up, but unreliable, PLLs are better)
      1 PLL with X Gyro reference
      2 PLL with Y Gyro reference
      3 PLL with Z Gyro reference
      4 PLL with external 32.768kHz reference  ;\unknown if available in 3DS,
      5 PLL with external 19.2MHz reference    ;/maybe from 32KHz RTC output?
      6 Reserved
      7 Reserved

Gyro Datasheets

      Hardware: ITG-3200-Datasheet.pdf    ITG-3200 Product Specification (v1.7)
      Software: ITG-3200-Register-Map.pdf ITG-3200 Register Map (v1.0)

Older versions did include the Register Map in the Product Specification.

3DS I2C Gyroscope (new version)

NEW_GYRO Register Map - InvenSense ITG-1010

      04h/05h XG_OFFS_TC_H/L R/W Temperature Compensation X (10bit)
      07h/08h YG_OFFS_TC_H/L R/W Temperature Compensation Y (10bit)
      0Ah/0Bh ZG_OFFS_TC_H/L R/W Temperature Compensation Z (10bit)
      13h/14h XG_OFFS_USRH/L R/W User DC Bias Compensation X (16bit)
      15h/16h YG_OFFS_USRH/L R/W User DC Bias Compensation Y (16bit)
      17h/18h ZG_OFFS_USRH/L R/W User DC Bias Compensation Z (16bit)
      19h     SMPLRT_DIV     R/W Sample Rate Divider
      1Ah     CONFIG         R/W Configuration
      1Bh     GYRO_CONFIG    R/W Gyroscope Configuration
      23h     FIFO_EN        R/W FIFO Channel Enable
      37h     INT_PIN_CFG    R/W INT Pin / Bypass Enable Configuration
      38h     INT_ENABLE     R/W Interrupt Enable
      3Ah     INT_STATUS     R   Interrupt Status
      41h/42h TEMP_OUT_H/L   R   Temperature Measurement  TEMP_OUT  (16bit)
      43h/44h GYRO_XOUT_H/L  R   Gyroscope Measurements X GYRO_XOUT (16bit)
      45h/46h GYRO_YOUT_H/L  R   Gyroscope Measurements Y GYRO_YOUT (16bit)
      47h/48h GYRO_ZOUT_H/L  R   Gyroscope Measurements Z GYRO_ZOUT (16bit)
      6Ah     USER_CTRL      R/W User Control
      6Bh     PWR_MGMT_1     R/W Power Management 1
      6Ch     PWR_MGMT_2     R/W Power Management 2
      72h/73h FIFO_COUNTH/L  R/W FIFO Count Register (10bit)
      74h     FIFO_R_W       R/W FIFO Read/Write Data
      75h     WHO_AM_I       R   Device ID       - WHO_AM_I[6:1] -
      80h-FFh Undocumented (in New3DSXL these are same as 00h-7Fh)

Note: The 16bit H/L values are in BIG-ENDIAN format.
NEW_GYRO[04h/05h] - XG_OFFS_TC_H/L - Temperature Compensation X (10bit, R/W)
NEW_GYRO[07h/08h] - YG_OFFS_TC_H/L - Temperature Compensation Y (10bit, R/W)
NEW_GYRO[0Ah/0Bh] - ZG_OFFS_TC_H/L - Temperature Compensation Z (10bit, R/W)
Unknown if these registers are implemented in 3DS (register 00h..0Bh contain "garbage" that rather doesn't look like 10bit values).

      0-9   Signed 10bit, in 2.52 mdps/C steps (default=factory programmed)
      10-15 Unused (should be 0)

Writing 0000h disables temperature compensation (this doesn't affect the factory values, which will be restored upon reset/power-up).
NEW_GYRO[13h/14h] - XG_OFFS_USRH/L - User DC Bias Compensation X (16bit, R/W)
NEW_GYRO[15h/16h] - YG_OFFS_USRH/L - User DC Bias Compensation Y (16bit, R/W)
NEW_GYRO[17h/18h] - ZG_OFFS_USRH/L - User DC Bias Compensation Z (16bit, R/W)

      0-15  Signed 16bit, subtracted from the sensor values

NEW_GYRO[19h] - SMPLRT_DIV - Sample Rate Divider (R/W)

      0-7  Sample Rate Divider (00h..FFh=Divide by 1..100h) (initially 00h)

This register specifies the divider from the gyroscope output rate that can be used to generate a reduced Sample Rate.

      When FCHOICE_B=0 and DLPF_CFG=1..6   --> Sample Rate Divider IS USED
      When FCHOICE_B=0 and DLPF_CFG=0 or 7 --> Sample Rate is fixed at 8kHz ???
      When FCHOICE_B=1..3                  --> Sample Rate is fixed at 32kHz

The sensor register output and FIFO output are both based on the Sample Rate.
When this register is effective under the FCOICE_B and DLPF_CFG settings, the reduced Sample Rate is generated by the formula below:

      Sample Rate = Gyroscope Output Rate / (1 + SMPLRT_DIV)

where Gyroscope Output Rate = 1kHz.
NEW_GYRO[1Ah] - CONFIG - Configuration (R/W)

      0-2 DLPF_CFG      Configures the Digital Low Pass Filter DLPF setting
      3-5 EXT_SYNC_SET  Configures the Frame Sync FSYNC pin sampling
      6   FIFO_MODE     FIFO Mode (0=Overwrite oldest data, 1=Stop when full)
      7   -             Reserved

Please note that the DLPF can only be used when FCHOICE_B=0 (Register 27).
An external signal connected to the FSYNC pin can be sampled by configuring EXT_SYNC_SET.
Signal changes to the FSYNC pin are latched so that short strobes may be captured. The latched FSYNC signal will be sampled at the Sampling Rate, as defined in register 25. After sampling, the latch will reset to the current FSYNC signal state.
The sampled value will be reported in place of the least significant bit in a sensor data register determined by the value of EXT_SYNC_SET according to the following table.

      EXT_SYNC_SET  FSYNC Bit Location
      0             Input disabled
      1             TEMP_OUT_L.bit0
      2             GYRO_XOUT_L.bit0
      3             GYRO_YOUT_L.bit0
      4             GYRO_ZOUT_L.bit0

The DLPF is configured by DLPF_CFG, when FCHOICE_B=0. The gyroscope and temperature sensor are filtered according to the value of DLPF_CFG and FCHOICE_B as shown in the table below.

      FCHOICE_B  DLPF_CFG   <---Gyroscope------->   <--Temperature Sensor-->
      <1> <0>               Bandwidth Delay   Fs    Bandwidth  Delay
      0   0      0          250Hz     0.97ms  8kHz  4000Hz     0.04ms
      0   0      1          184Hz     2.9ms   1kHz  188Hz      1.9ms
      0   0      2          92Hz      3.9ms   1kHz  98Hz       2.8ms
      0   0      3          41Hz      5.9ms   1kHz  42Hz       4.8ms
      0   0      4          20Hz      9.9ms   1kHz  20Hz       8.3ms
      0   0      5          10Hz      17.85ms 1kHz  10Hz       13.4ms
      0   0      6          5Hz       33.48ms 1kHz  5Hz        18.6ms
      0   0      7          3600Hz    0.17ms  8kHz  4000Hz     0.04ms
      -   1      -          8800Hz    0.064ms 32kHz 4000Hz     0.04ms
      1   0      -          3600Hz    0.11ms  32kHz 4000Hz     0.04ms

NEW_GYRO[1Bh] - GYRO_CONFIG - Gyroscope Configuration (R/W)

      0-1 FCHOICE_B Choose the gyroscope output setting
      2   -         Reserved
      3-4 FS_SEL    Gyroscope Full Scale range select
      5   ZG_ST     Gyroscope X self test (0=Normal, 1=Perform test)
      6   YG_ST     Gyroscope Y self test (0=Normal, 1=Perform test)
      7   XG_ST     Gyroscope Z self test (0=Normal, 1=Perform test)

The electro/mechanical self test bits will move the sensor's proof masses, the result can be then seen in sensor registers [43h..48h].

      FS_SEL Full Scale Range
      0      +/-250 ø/s
      1      +/-500 ø/s
      2      +/-1000 ø/s
      3      +/-2000 ø/s

FCHOICE_B, in conjunction with DLPF_CFG (Register 1Ah), is used to choose the gyroscope output setting. For further information regarding the operation of FCHOICE_B, please refer to Section 4.2.
NEW_GYRO[23h] - FIFO_EN - R/W FIFO Channel Enable (R/W)

      0-3 -            Reserved
      4   ZG_FIFO_EN   Output Gyroscope Z to FIFO (0=No, 1=Yes)
      5   YG_FIFO_EN   Output Gyroscope Y to FIFO (0=No, 1=Yes)
      6   XG_FIFO_EN   Output Gyroscope X to FIFO (0=No, 1=Yes)
      7   TEMP_FIFO_EN Output Temperature to FIFO (0=No, 1=Yes)

NEW_GYRO[37h] - INT_PIN_CFG - INT Pin / Bypass Enable Configuration (R/W)

      0-1 -                 Reserved
      2   FSYNC_INT_MODE_EN FSYNC Pin Enable  (0=Disable, 1=Enable FSYNC IRQ)
      3   FSYNC_INT_LEVEL   FSYNC Pin Act Low (0=Active High, 1=Active Low)
      4   INT_RD_CLEAR     Interrupt Clear (0=Upon IntStatus read, 1=Upon Any read)
      5   LATCH_INT_EN     INT Pin Hold       (0=50us pulse, 1=Hold until ack)
      6   INT_OPEN         INT Pin Open Drain (0=Push-pull, 1=Open drain)
      7   INT_LEVEL        INT Pin Active Low (0=Active High, 1=Active Low)

FSYNC_INT_MODE_EN: When bit2 is equal to 1, the FSYNC pin will trigger an interrupt when it transitions to the level specified by FSYNC_INT_LEVEL. When a FSYNC interrupt is triggered, the FSYNC_INT bit in Register 58 will be set to 1. An interrupt is sent to the host processor if the FSYNC interrupt is enabled by the FSYNC_INT_EN bit in Register 56.
NEW_GYRO[38h] - INT_ENABLE - Interrupt Enable (R/W)

      0   DATA_RDY_EN   Enable Data Ready interrupt           (0=Disable, 1=Enable)
      1-2 -             Reserved
      3   FSYNC_INT_EN  Enable FSYNC pin interrupt (0=Disable, 1=Use FSYNC as IRQ)
      4   FIFO_OFLOW_EN Enable FIFO buffer overflow interrupt (0=Disable, 1=Enable)
      5-7 -             Reserved

The Data Ready interrupt is triggered when all the sensor registers have been written with the latest gyro sensor data.
NEW_GYRO[3Ah] - INT_STATUS - Interrupt Status (R)

      0   DATA_RDY_INT   Data Ready (sample rate) interrupt (0=No, 1=Yes/IRQ)
      1-2 -              Reserved
      3   FSYNC_INT      FSYNC Frame Sync interrupt         (0=No, 1=Yes/IRQ)
      4   FIFO_OFLOW_INT FIFO Overrun interrupt             (0=No, 1=Yes/IRQ)
      5-7 -              Reserved

Each bit will clear after the register is read.
NEW_GYRO[41h/42h] - TEMP_OUT_H/L - Temperature Measurement (R, 16bit)
NEW_GYRO[43h/44h] - GYRO_XOUT_H/L - Gyroscope Measurements X (R, 16bit)
NEW_GYRO[45h/46h] - GYRO_YOUT_H/L - Gyroscope Measurements Y (R, 16bit)
NEW_GYRO[47h/48h] - GYRO_ZOUT_H/L - Gyroscope Measurements Z (R, 16bit)

      0-15  Most recent sensor value, signed 16bit, updated at sample rate

These sensor registers [41h..48h], are composed of two sets of registers: an internal register set and a user-facing read register set.

     The internal register set is always updated at the Sample Rate.
     The user-facing read register set duplicates the internal register set's
     data values whenever the serial interface is idle. This guarantees that a
     burst read of sensor registers will read measurements from the same sampling
     instant.

Note that if burst reads are not used, the user is responsible for ensuring a set of single byte reads correspond to a single sampling instant by checking the Data Ready interrupt.
Temperature: The scale factor and offset for the temperature sensor are found in the Electrical Specifications table in Product Specification document.
NEW_GYRO[6Ah] - USER_CTRL - User Control (R/W)

      0   Reset Gyro/Temp sensor signal paths (0=No/ready, 1=Reset/busy?)
      1   Reserved
      2   FIFO Reset (clear fifo)             (0=No/ready, 1=Reset/busy?)
      3   Reserved
      5   Reserved
      4   Primary Interface select            (0=I2C/normal, 1=SPI/instead)
      6   FIFO Read Enable                    (0=Disable, 1=Enable)
      7   Reserved

It is "recommended" to have FIFO Read disabled when doing FIFO Reset.
NEW_GYRO[6Bh] - PWR_MGMT_1 - Power Management 1 (R/W)

      0-2 CLKSEL       Clock source select (see below)
      3   TEMP_DIS     Temperature sensor disable   (0=Normal, 1=Disable)
      4-5 -            Reserved
      6   SLEEP        Sleep Mode                   (0=Normal, 1=Sleep)
      7   DEVICE_RESET Reset all internal registers (0=No/ready, 1=Reset/busy?)

CLKSEL Clock Source

      00h = Internal 20MHz oscillator
      01h = PLL  ;\
      02h = PLL  ; gyroscope based clock (PLL)
      03h = PLL  ;
      04h = PLL  ;
      05h = PLL  ;/
      06h = Internal 20MHz oscillator
      07h = Reserved

The PLL is the default clock source upon power up (uh, but all registers except WHO_AM_I are said to be zero on power-up). In order for the gyroscope to perform to spec, the PLL must be selected as the clock source.
When the internal 20MHz oscillator is chosen as the clock source, the device can operate while having the gyroscopes disabled. However, this is only recommended if the user wishes to use the internal temperature sensor in this mode.
For further information regarding the device clock source, please refer to the relevant "Product Specification document" (uh, but this sentence comes from the Product Specification) and the Power Mode Transition Descriptions section in the Appendix (uh, but there is no Appendix).
Reset: The default values for each register can be found in "Section 3", uh?
NEW_GYRO[6Ch] - PWR_MGMT_2 - Power Management 2 (R/W)

      0   STBY_ZG Gyro Z standby mode  (0=Normal, 1=Standby)
      1   STBY_YG Gyro Y standby mode  (0=Normal, 1=Standby)
      2   STBY_XG Gyro X standby mode  (0=Normal, 1=Standby)
      3-5 -       Reserved bit(s)
      6-7 -       Reserved bit-pair?

To activate any gyro axis again, all three gyro axes must first be put into standby mode, and then be turned on simultaneously.
If the user wishes to put all three gyro axes into standby mode, the internal oscillator must be selected as the clock source.
If all three gyro axes are put into standby mode while the clock source of the device is set to the PLL (with the gyro drive generating the reference clock), the chip will hang due to an absence of a clock.
As long as one gyro axis is enabled, the drive circuit will remain active and the PLL will provide a clock.
NEW_GYRO[72h/73h] - FIFO_COUNTH/L - FIFO Count Register (10bit) (R/W)

      0-9   Number of bytes stored in the FIFO buffer (max=?)
      10-15 Reserved

The count value is latched when reading the High byte (ie. one can read H-then-L without risking carry-outs from L to H during reading).
NEW_GYRO[74h] - FIFO_R_W - FIFO Read/Write Data (R/W)

      0-7   FIFO Data

This register is used to read and write(?) data from the FIFO buffer.
Data is written to the FIFO in order of register number, (from lowest to highest). If all the FIFO enable flags (see below) are enabled, the contents of NEW_GYRO[41h..48h] will be written in order.
NEW_GYRO[75h] - WHO_AM_I - Device ID (always 68h) (R)

      0   Reserved ("Hard coded to 0")                               (R)
      1-6 I2C Device ID bit2-7 (always 34h, aka D0h/4 or D2h/4)      (R)
      7   Reserved ("Hard coded to 0")                               (R)

The device address D0h or D2h can be selected via AD0 pin (the AD0 pin is not reflected in this register). This register is read-only (unlike as OLD_GYRO).
NEW_GYRO[00h..0Dh] - Reserved/Undocumented
Reading these fourteen registers returns following weird values:

      BD DB D1 29 9C 1D 20 67 F4 1A 8C 08 B1 71

There should be 10bit temperature calibration values, but 9C1Dh,67F4h,8C08h exceed 10bit range.
The first two bytes (BDh,DBh) seem to resemble the 1st/2nd bytes of older RS232 gyroscope protocols.

3DS I2C Infrared Receiver/Transmitter (IrDA)

NXP SC16IS750
Single UART with I2C-bus/SPI interface, 64 bytes of transmit and receive FIFOs, IrDA SIR built-in support - Rev. 06 - 13 May 2008 Product data sheet
Register address byte (I2C)

      7    Unused (0)
      6-3  UART's internal register select
      2-1  Channel select (0) ;other values are reserved and should not be used.
      0    Unused (0)

Register set

     Normal register set (default mapping)
      00h.DLAB=0.R     RHR       Receive Holding Register
      00h.DLAB=0.W     THR       Transmit Holding Register
      08h.DLAB=0.R/W   IER       Interrupt Enable Register
      10h.W            FCR       FIFO Control Register
      10h.R            IIR       Interrupt Identification Register
      18h.R/W          LCR       Line Control Register
      20h.R/W          MCR       Modem Control Register
      28h.R            LSR       Line Status Register
      30h.normal.R     MSR       Modem Status Register
      38h.normal.R/W   SPR    Scratchpad Register
      40h.R            TXLVL     Transmitter FIFO Level
      48h.R            RXLVL     Receiver FIFO Level
      50h.R/W          IODir     Programmable I/O pins Direction  ;\IO only on
      58h.R/W          IOState   Programmable I/O pins State      ; SC16IS750
      60h.R/W          IOIntEna  I/O Interrupt Enable Register    ; and
      68h              reserved  Reserved (00h)                   ; SC16IS760
      70h.R/W          IOControl I/O Control register             ;/
      78h.R/W          EFCR      Extra Features Control Register
     Special/Enhanced registers (mapped depending on LCR/MCR/EFR bits):
      00h.DLAB=1.R/W   DLL       Baudrate Divisor Latch Low    ;\when LCR.bit7=1
      08h.DLAB=1.R/W   DLH       Baudrate Divisor Latch High   ;/and LCR<>BFh
      10h.LCR=BFh.R/W  EFR       Enhanced Features Register               ;\
      20h.LCR=BFh.R/W  XON1   Xon1 word                                   ; when
      28h.LCR=BFh.R/W  XON2   Xon2 word                                   ; LCR=BFh
      30h.LCR=BFh.R/W  XOFF1  Xoff1 word (whatever, maybe OUTGOING char?) ;
      38h.LCR=BFh.R/W  XOFF2  Xoff2 word (compare for INCOMING chars)     ;/
      30h.special.R/W  TCR       Transmission Control Register ;\when MCR.bit2=1
      38h.special.R/W  TLR       Trigger Level Register        ;/and EFR.bit4=1

[2] These bits in can only be modified if register bit EFR[4] is enabled.
[5] After Receive FIFO or Transmit FIFO reset (through FCR[1:0]), the user must wait at least 2' ??? Tclk of XTAL1 before reading or writing data to RHR and THR, respectively.
[8] IrDA mode slow/fast for SC16IS760, slow only for SC16IS750.
IR[00h.DLAB=0.R] - RHR - Receive Holding Register (R)
The receiver section consists of the Receiver Holding Register (RHR) and the Receiver Shift Register (RSR). The RHR is actually a 64-byte FIFO. The RSR receives serial data from the RX pin. The data is converted to parallel data and moved to the RHR. The receiver section is controlled by the Line Control Register. If the FIFO is disabled, location zero of the FIFO is used to store the characters.
IR[00h.DLAB=0.W] - THR - Transmit Holding Register (W)
The transmitter section consists of the Transmit Holding Register (THR) and the Transmit Shift Register (TSR). The THR is actually a 64-byte FIFO. The THR receives data and shifts it into the TSR, where it is converted to serial data and moved out on the TX pin. If the FIFO is disabled, the FIFO is still used to store the byte. Characters are lost if overflow occurs.
IR[10h.W] - FCR - FIFO Control Register (W)

      7-6  Trigger level for the RX FIFO (0..3 = 8,16,56,60 chars)
      5-4  Trigger level for the TX FIFO (0..3 = 8,16,32,56 spaces)
      3    Reserved
      2    TX FIFO Reset (0=No change, 1=Clear TX FIFO)
      1    RX FIFO Reset (0=No change, 1=Clear RX FIFO)
      0    RX/TX FIFO enable (0=Disable, 1=Enable)

Bit1,2: FIFO reset requires at least two XTAL1 clocks, therefore, they cannot be reset without the presence of the XTAL1 clock.
Bit4-5: Can only be modified and enabled when EFR[4] is set. This is because the transmit trigger level is regarded as an enhanced function.
IR[18h] - LCR - Line Control Register (R/W)

      7    Divisor latch access enable (DLAB) (0=Normal, 1=Access DLL/DLH)
      6    Break control bit   (0=Off/Normal, 1=Break/Force TX to logic 0)
      5-4  Parity Type         (0=Odd, 1=Even, 2=Forced1, 3=Forced0)
      3    Parity Enable       (0=Disable, 1=Enable)
      2    Number of stop bits (0=1bit, 1=2bit, or 1.5bit in 5bit mode)
      1-0  Word length         (0=5bit, 1=6bit, 2=7bit, 3=8bit)

IR[28h.R] - LSR - Line Status Register (R)

      7    FIFO data error (0=None, 1=At least one Error/Break anywhere in RX FIFO)
      6    THR and TSR empty   (0=Not empty, 1=Empty)  (TX FIFO and TX shift reg)
      5    THR empty           (0=Not empty, 1=Empty)  (TX FIFO)
      4    Break interrupt     (0=No, 1=Break, next RX FIFO char reads as 00h)
      3    Framing Error       (0=No, 1=Error; bad stop bit in data from RX FIFO)
      2    Parity Error        (0=No, 1=Error; in data being read from RX FIFO)
      1    Overrun Error       (0=No, 1=Error; overrun has occurred)
      0    Data in Receiver    (0=No, 1=At least one character in the RX FIFO)

Bit2-4 reflect the error bits (BI, FE, PE) of the character at the top of the RX FIFO (next character to be read). Therefore, errors in a character are identified by reading the LSR and then reading the RHR.
IR[20h] - MCR - Modem Control Register (R/W)

      7    Clock Divisor    (0=Div1 clock input, 1=Div4 clock input)
      6    IrDA mode enable (0=Normal UART mode, 1=IrDA mode) (aka pulse RX/TX?)
      5    Xon Any function (0=Disable, 1=Enable)
      4    Enable Loopback  (0=Normal, 1=local Loopback mode, internal)
            In this mode the MCR[1:0] signals are looped back into MSR[4:5] and
            the TX output is looped back to the RX input internally.
      3    Reserved
      2    TCR/TLR register access enable (0=Disable, 1=Enable)
      1    RTS output (if Auto RTS disabled)        (0=High/Inactive, 1=Low/Active)
            In Loopback mode, controls MSR[4].
      0    DTR output (GPIO5) (if IOControl.bit1=1) (0=High/Inactive, 1=Low/Active)
            Writing to IOState bit 5 will not have any effect on this pin.

Bit2,5-7 can only be modified when EFR[4] is set, ie. EFR[4] is a write enable.
Bit0: Only available on SC16IS750/SC16IS760.
IR[30h.normal.R] - MSR - Modem Status Register (R)

      7    CD input state (inverted, 1=Not HIGH, or so)     ;\only if modem mode
      6    RI input state (inverted, 1=Not HIGH, or so)     ; (IOControl.bit1=1)
      5    DSR input state (inverted, 1=Not HIGH, or so)    ;/
      4    CTS input state (inverted, 1=Not HIGH, or so)
      3    CD input changed state                  (0=No, 1=Yes)    ;\
      2    RI input changed state from LOW to HIGH (0=No, 1=Yes)    ; cleared
      1    DSR input changed state                 (0=No, 1=Yes)    ; on read
      0    CTS input changed state                 (0=No, 1=Yes)    ;/

Bit1-3,5-7: Only available on SC16IS750/SC16IS760.
Remark: The primary inputs RI, CD, CTS, DSR are all active LOW.
Reading IOState bit 6,6,4 does not reflect the true state of CD,RI,DSR pin, uh?
IR[08h] - IER - Interrupt Enable Register (R/W)

      7    CTS change interrupt enable          (0=Disable, 1=Enable)
      6    RTS change interrupt enable          (0=Disable, 1=Enable)
      5    Xoff received interrupt              (0=Disable, 1=Enable)
      4    Sleep mode                           (0=Disable, 1=Sleep Mode)
      3    Modem Status Interrupt               (0=Disable, 1=Enable)
      2    Receive Line Status error interrupt  (0=Disable, 1=Enable)
      1    Transmit Holding Register interrupt  (0=Disable, 1=Enable)
      0    Receive Holding Register interrupt   (0=Disable, 1=Enable)

Bit4-7 can only be modified if EFR[4] is set, that is, EFR[4] is a write enable. Re-enabling IER[1] will not cause a new interrupt if the THR is below the threshold.
Bit3: Only available on the SC16IS750/SC16IS760.
Bit3: See IOControl.bit1 for the description of how to program the pins as modem pins.
IR[10h.R] - IIR - Interrupt Identification Register (R)

      7    Mirror of FCR.bit0: RX/TX FIFO enable (0=Disable, 1=Enable) ;\both same
      6    Mirror of FCR.bit0: RX/TX FIFO enable (0=Disable, 1=Enable) ;/
      5-1  Interrupt source (5bit encoded, see below) (valid when bit0=0)
      0    Interrupt status (0=IRQ pending, 1=No IRQ pending)

Interrupt sources:

      Src Prio Expl.
      03h 1    Receiver Line Status error
      06h 2    Receiver time-out interrupt
      02h 2    RHR interrupt
      01h 3    THR interrupt
      00h 4    MSR Modem interrupt           (SC16IS750/SC16IS760 only)
      18h 5    IOState GPIO input pin change (SC16IS750/SC16IS760 only)
      08h 6    received Xoff signal/special character
      10h 7    CTS, RTS change state from active(LOW) to inactive(HIGH)

Burst reads on the serial interface should not be performed on the IIR register (ie. don't read multiple elements on the I2C-bus without a STOP or repeated START condition, and don't read multiple elements on the SPI bus without de-asserting the CS pin).
IR[10h.LCR=BFh] - EFR - Enhanced Features Register (R/W)

      7    CTS flow control enable (0=Disable, 1=Enable; stop TX upon CTS=HIGH)
      6    RTS flow control enable (0=Disable, 1=Enable; change RTS upon TCR)
             RTS pin goes HIGH when RX FIFO halt trigger level TCR[3:0] is reached
             RTS pin goes LOW when RX FIFO resume trigger level TCR[7:4] is reached
      5    Special character detect (0=Disable, 1=Enable, compare with Xoff2)
             If a Xoff2 match occurs, the received data is transferred to FIFO and
             IIR.bit4 is set to 1 to indicate a special character has been detected
      4    Enhanced functions enable bit (0=Disable, 1=Enable)
             Enables writing to IER[7:4], FCR[5:4], MCR[7:5]
      3-0  Combinations of software flow control can be selected by programming
             these bits. See Table 3 "Software flow control options (EFR[3:0])".

IR[00h.DLAB=1] - DLL - Baudrate Divisor Latch Register Low, bit0-7 (R/W)
IR[08h.DLAB=1] - DLH - Baudrate Divisor Latch Register High, bit8-15 (R/W)

      15-0  16bit divisor for generation of the clock in the baudrate generator

Remark: DLL and DLH can only be written to before Sleep mode is enabled, that is, before IER[4] is set.
IR[30h.MCR[2]=1 and EFR[4]=1] - TCR - Transmission Control Register (R/W)

      7-4  RX FIFO flow control resume trigger level  (N*4) (0..14 = 0..56 chars)
      3-0  RX FIFO flow control halt trigger level    (N*4) (1..15 = 4..60 chars)

RX FIFO threshold levels to stop/start transmission during hardware/software flow control (ie. for RTS pin, or Xon/Xoff chars).
Remark: TCR can only be written to when EFR[4]=1 and MCR[2]=1.
The programmer must program the TCR such that Halt>Resume, aka TCR[3:0]>TCR[7:4]. There is no built-in hardware check to make sure this condition is met.
Also, the TCR must be programmed with this condition before auto RTS or software flow control is enabled to avoid spurious operation of the device.
IR[38h.MCR[2]=1 and EFR[4]=1] - TLR - Trigger Level Register (R/W)

      7-4  RX FIFO interrupt trigger level (N*4) (1..15 = 4..60 chars available)
      3-0  TX FIFO interrupt trigger level (N*4) (1..15 = 4..60 spaces available)

Remark: TLR can only be written to when EFR[4]=1 and MCR[2]=1. If TLR[3:0] or TLR[7:4] are logical 0, the selectable trigger levels via the FIFO Control Register (FCR) are used for the transmit and receive FIFO trigger levels. Trigger levels from 4 characters to 60 characters are available with a granularity of four. The TLR should be programmed for NÏ4, where N is the desired trigger level.
When the trigger level setting in TLR is zero, the SC16IS740/750/760 uses the trigger level setting defined in FCR. If TLR has non-zero trigger level value, the trigger level defined in FCR is discarded. This applies to both transmit FIFO and receive FIFO trigger level setting.
When TLR is used for RX trigger level control, FCR[7:6] should be left at the default state, that is, '00'.
IR[40h.R] - TXLVL - Transmitter FIFO Level register (R)

      7    Unused (0)
      6-0  Number of spaces available in TX FIFO (00h..40h; 00h=Full, 40h=Empty)

IR[48h.R] - RXLVL - Receiver FIFO Level register (R)

      7    Unused (0)
      6-0  Number of characters stored in RX FIFO (00h..40h; 00h=Empty, 40h=Full)

IR[50h] - IODir - Programmable I/O pins Direction register (R/W)
This register is only available on the SC16IS750 and SC16IS760.

      7-0  IODir set GPIO pins [7:0] to input or output (0=Input, 1=Output)

Remark: If there is a pending input (GPIO) interrupt and IODir is written, this pending interrupt will be cleared, that is, the interrupt signal will be negated.
IR[58h] - IOState - Programmable I/O pins State Register (R/W)

      7-0  IOState Write this register: set the logic level on the output pins
              0=set output pin to zero
              1=set output pin to one
            Read this register: return states of all pins

This register is only available on the SC16IS750 and SC16IS760.
When read, this register returns the actual state of all I/O pins.
When write, each register bit will be transferred to the corresponding IO pin programmed as output.
IR[60h] - IOIntEna - I/O Interrupt Enable Register (R/W)

      7-0  Input change interrupt enable (0=Disable, 1=Enable)

This register is only available on the SC16IS750 and SC16IS760.
This register enables the interrupt due to a change in the I/O configured as inputs. If GPIO[7:4] are programmed as modem pins, their interrupt generation must be enabled via IER register bit3. In this case bit4-7 of IOIntEna will have no effect on GPIO[7:4].
IR[70h] - IOControl - I/O Control register (R/W)

      7-4  Reserved
      3    Software reset (0=No change, 1=Reset)                    (W)
      2    Reserved
      1    Use GPIO[7:4] as GPIO or as modem pins (0=GPIO, 1=RI,CD,DTR,DSR)
      0    IOLATCH enable/disable inputs latching
            0 = input values are not latched. A change in any input generates an
             interrupt. A read of the input register clears the interrupt. If the
             input goes back to its initial logic state before the input register
             is read, then the interrupt is cleared.
            1 = input values are latched. A change in the input generates an
             interrupt and the input logic value is loaded in the bit of the
             corresponding input state register (IOState). A read of the IOState
             register clears the interrupt. If the input pin goes back to its
             initial logic state before the interrupt register is read, then the
             interrupt is not cleared and the corresponding bit of the IOState
             register keeps the logic value that initiates the interrupt.

This register is only available on the SC16IS750 and SC16IS760.
Remark: As I/O pins, the direction, state, and interrupt of GPIO4 to GPIO7 are controlled by the following registers: IODir, IOState, IOIntEna, and IOControl. The state of CD, RI, DSR pins will not be reflected in MSR[7:5] or MSR[3:1], and any change of state on these three pins will not trigger a modem status interrupt (even if enabled via IER[3]), and the state of the DTR pin cannot be controlled by MCR[0].
As modem CD, RI, DSR pins, the status at the input of these three pins can be read from MSR[7:5] and MSR[3:1], and the state of DTR pin can be controlled by MCR[0]. Also, if modem status interrupt bit is enabled, IER[3], a change of state of RI, CD, DSR pins will trigger a modem interrupt. Bit[7:4] of the IODir, IOState, and IOIntEna registers will not have any effect on these three pins.
IR[78h] - EFCR - Extra Features Control Register (R/W)

      7    IrDA pulse mode (0=Max115kbit/s, ratio 3/16, 1=Max1152kbit/s, ratio 1/4)
      6    Reserved
      5    Invert RTS signal in RS-485 mode (0=RTS=0 during TX, 1=RTS=1 during TX)
      4    Enable the transmitter to control the RTS pin (0=Disable, 1=Enable)
      3    Reserved
      2    Disable transmitter  (0=Normal, 1=Disable; stop forwarding THR to TSR)
            UART does not send serial data out on the transmit pin, but the
            transmit FIFO will continue to receive data from host until full.
            Any data in the TSR will be sent out before the transmitter goes into
            disable state.
      1    Disable receiver     (0=Normal, 1=Disable)
            UART will stop receiving data immediately once this bit set to 1, and
            any data in the TSR?? will be sent to the receive FIFO.
            User is advised not to set this bit during receiving.
      0    Enable 9bit or Multidrop mode  (0=Normal RS-232, 1=Enable RS-485)

Bit7 is SC16IS760 only.

     ____________________________ Infrared IrDA Notes ____________________________

Infrared Usage in 3DS
The 3DS doesn't have any expansion connector, and it's instead using the IrDA port for expansion hardware (with external batteries):

     - Circle Pad Pro (a second Circle Pad, attached right of the A/B/X/Y buttons)
     - NFC Near-field communication (for Amiibo figures)

For the NFC thing, see here:
3DS NFC Adapter
That add-on hardware exists for Old3DS only. The New3DS does have equivalent hardware built-in, and thus doesn't need that add-ons.
Additionally, IrDA could be used for things like file transfers, unknown if there are 3DS tools supporting such things?
Infrared Signals
The SC16IS750 UART/IrDA SIR datasheet does mainly describe the UART part, and barely mentions infrared at all (apart from saying that the chip is IrDA SIR compatible, and that IrDA can be enabled in MCR.bit6).
Going by other sources, IrDA SIR works like "UART over infrared". In lack of further details, here some guesses on how it might work (and how far it is (or isn't) compatible with regular cable-based UARTs):

     - RX/TX are probably using pulsed signals instead of constant LOW/HIGH levels?
     - RTS/CTS/DTR/DSR are probably not implemented at all?
     - Simultaneous RX+TX might work in opposite light-direction, if no reflection?
     - Infrared interruptions and noise may require additional error checking?
     - Infrared at less than 10mm (as in Circle Pad Pro) may work 100% error-free?

Infrared Protocol
Specifications for the IrDA standard aren't available for free, and there's little known about the protocol:

     - IrDA protocol supports file transfers from one device to another
     - IrDA protocol must include some sort of packet headers and checksums
     - And probably much stuff

However, it's unknown if Nintendo did bother to follow the IrDA standard in their Circle Pad Pro and NFC add-ons. It's also possible that they have just used a custom UART-like transfer protocol for that hardware.
Infrared Range
IrDA is supposed for short-range transfers (about 20cm - 100cm) in binary format. As such, it isn't intended to use the hardware for things like classic TV remote controls (although... maybe it could be tweaked to output TV remote signals on TX pin... possibly in UART mode with IrDA disabled?).

3DS I2C LCD Screen Controllers

I2C Bus/Device 1:2Ch - Upper LCD screen (lcd0)
I2C Bus/Device 1:2Eh - Lower LCD screen (lcd1)
LCD controllers for top/bottom screen.
I2C Access
I2C writing works as for most other I2C chips:

      I2cWriteCmd (Device+0, Index, Data)

However, I2C reading works uncommon:

      I2cWriteCmd (Device+0, 40h, ReadIndex)
      I2cReadCmd  (Device+1, ReadIndex, Data)

Ie. the LCD chips distinguish between WriteIndex and ReadIndex, with the ReadIndex being set by writing to register 40h. The ReadIndex value in the response can be ignored (or verified to be same as the written ReadIndex value).
I2C Registers

      00h      Zero                                                        (-)
      01h      Display on/off (10h=Display on, 11h=Display black) ;bit0,4 is R/W
      02h      Usually 01h, but bit0 is R/W
      03h      Usually 00h, but bit0-7 is R/W
      04h..10h Zero                                                        (-)
      11h      Whatever (set to 10h during init, maybe bit4=reset?)
      12h..3Fh Zero                                                        (-)
      40h      Read Index for I2C read (00h..FFh)
      41h..4Fh Zero                                                        (-)
      50h      Bit0 is R/W  (set to 1 for top-screen; left 0 on bottom-screen)
      51h..53h Zero                                                        (-)
      54h      Usually 00h, but bit0 is R/W
      55h      Usually 00h, but bit0-1 is R/W
      56h..5Fh Zero                                                        (-)
      60h      Whatever (set to 00h during init)  ;bit0 is R/W ?
      61h      Status (initially B4h=Top Screen, F8h=Bottom Screen)        (R?)
      62h      Status (01h=Ready)  (except, broken top screen reads 00h?)  (R?)
      63h      Zero                                                        (-)
      64h      Whatever/Fixed 03h                                          (R)
      65h..AEh Zero                                                        (-)
      AFh      Usually 00h, but bit0-7 is R/W
      B0h..D3h Zero                                                        (-)
      D4h      Usually 00h, but lower 4bit are R/W
      D5h      Usually 00h, but bit0-7 is R/W
      D6h..FDh Zero                                                        (-)
      FEh      Usually 00h, but bit0-7 is R/W
      FFh      Maybe Chip ID (10h=Top Screen, C7h=Bottom Screen)           (R)

Odd effect observed during testing: Setting LCD[AFh]=AAh causes MANY more registers to become nonzero; this doesn't happen for other values like LCD[AFh]=0Fh,F0h,FFh.
bootrom error screen init sequence for the I2C registers:

      LCD[11h]=10h     ;whatever
      LCD[50h]=01h     ;whatever, this one done for TOP screen only
      LCD[60h]=00h     ;whatever
      LCD[01h]=10h/11h ;on/off (10h=display on, 11h=display black)

The bootrom additionally checks if status LCD[62h]=01h=Ready.

3DS I2C New3DS Near-Field Communication (NFC)

I2C Bus/Device 1:EEh - Near-Field Communication (NFC) (New3DS-only)
This device is transferring command/response packets on the I2C bus (so one must only transfer Device+Data bytes; without any register Index values).
Datasheets and Specs
The NFC controller appears to be a 32pin Broadcom BCM20791 chip, there is no datasheet for that chip, however, a datasheet for 34pin BCM20793S chip does exist, but unfortunately without any specs on the transfer protocol.
Specifications for the lower-level transfer protocol (and maybe even the I2C bus protocol?) are made by the "NFC Forum" (a non-profit organization that charges lots of money for a copy of those specs).
There is some android open source code for "bcm2079x" available.
New3DS Transfer Protocol...
Command request / response structure:

      00h 1     Normally 10h?
      01h 1     Command source / destination
      02h 1     CmdID
      03h 1     Payload size (LEN)
      04h LEN   Data/parameters

The command response payload is usually at least 1-byte, where that byte appears to be normally 00h. For command requests the payload data is the command parameters.
For command requests sent to the NFC tag itself, Cmd[1]=0x0 and CmdID=0x0. The command request payload data here is the actual command request data for the NFC tag, starting with the CmdID u8 at payload+0.
During NFC module startup, a certain command (?) is sent to the controller which eventually (after various cmd-reply headers etc) returns the following after the first byte in the payload:

      000000: 44 65 63 20 32 32 20 32 30 31 32 31 34 3a 35 33  Dec 22 201214:53
      000010: 3a 35 30 01 05 0d 46 05 1b 79 20 07 32 30 37 39  :50...F..y .2079
      000020: 31 42 35                                         1B5

Or that is: "Dec 22 201214:53:50<binary>20791B5". Therefore, this appears to return the part-number of the NFC controller (other command request(s) / response(s) use this part-number value too).
Actually, 20791B5 seems to be NFC certification number for an unspecified Broadcom product (or possibly 20791B5 is the product name itself... yes, apparently it's Broadcom BCM20791).
Protocol = NFC Forum NFC Controller Interface (NCI) for host interface
NFC controller commands

      CmdRequest[1, uh?]  CmdID   Payload data for parameters
      2Eh                 2Fh     Firmware image for this chunk, size varies.

This is used during NFC module startup to upload the firmware image to the NFC controller. This is used repeatedly to upload multiple chunks of the image.
Power-up
After power-up, the NFC chip automatically sends these bytes upon I2C reads:

      10 60 00 02 00 01     ;followed by endless FF bytes

That seems to be a 4-byte header, with 2-byte data, as indicated in hdr[3]=02h.
NFC Interrupt
Triggers when there is data available for reading. Unknown if there is also a way for determining if the thing is ready for writing a new command... maybe one should simply wait for a response packet after sending any command packets?
Old3DS Version
The Old3DS did have an external NFC Adapter add-on, accessed via IrDA.
3DS NFC Adapter
The 3DS OS is supposedly having backwards/forwards compatible NFC functions, but the underlying transfer protocol seems to be completely different (relying on IrDA to communicate with the adpater firmare, instead of directly accessing the BCM20791 chip).

3DS NFC Adapter

The Nintendo NFC adapter, formally Nintendo NFC Reader/Writer and codenamed Fangate, is an external device which adds NFC capabilities for amiibos to old Nintendo 3DS and Nintendo 2DS consoles, using the infrared port on the back of the console.
It launched simultaneously with Animal Crossing Happy Home Designer, with which it's optionally bundled; it can also be bought standalone at a nominal(?) price of 21 EUR.
Technical details
Based on analysis of the fangate_updater.bin file, which is part of the old Nintendo 3DS operating system since 9.3.0-21 and contains the firmware running on the external adapter; and analysis of the NFC Services running on old 3DS.

      SOC inside the adapter: Broadcom BCM20791B1
                              or ST proprietary "MCU-FGT/rev.A/GH24S VQ"
                                uh, either or? or rather both?
                                is that guessed from fangate_updater.bin,
                                or seen on photos of the actual pcb/hardware?
      CPU:            ARM Cortex M0

Memory map:

      Address    Size    Description
      08008000h  256KB?  Firmware (fangate_updater.bin)
      20000000h  128KB?  RAM
      40023C00h  1Ch     FLASH ROM control
      E000ED00h  104h    ARM Cortex system control block

Layer 1 - IR communications framing format
Packets are sent using IrDA-SIR (using ir:USER) at 115200 bps 8N1 (eight data bits, no parity, one stop bit).

     IR framing format - short frame (max 3Fh data bytes):
      00h   1  Synchronization byte (A5h)
      01h   1  Reserved for future use (00h)
      02h   1  bit7:RFU (0), bit6:Short frame (0), bit0-5:Payload size
      03h   N  Payload
      03h+N 1  CRC-8-CCITT for whole packet [00h..N+02h]  ;uh, before/after XORing?
     IR framing format - long frame (max 3FFFh data bytes):
      00h   1  Synchronization byte (A5h)
      01h   1  Reserved for future use (???)
      02h   1  bit7:RFU (0), bit6:Long frame (1), bit0-5: Payload size upper bits
      03h   1  Payload size (lower 8 bits)
      04h   N  Payload (XOR-encrypted)
      04h+N 1  CRC-8-CCITT for whole packet [00h..N+03h]  ;uh, before/after XORing?

The payload is encrypted using a XOR-based encryption:

        halfCount = size/2          ;Divide by 2 rounding towards zero
        xorval = htobe16(0xE963)    ;that is, BIG-ENDIAN ?
        for (i = 0; i < halfCount; i++)
          xorval = xorval XOR = src[i]
          dst[i] = xorval

Layer 2 - "ircom"
ircom is a simple stateful point-to-point master-slave communication protocol built on top of IR layer 1.

      00h 4   Random (makes the whole packet look random after XOR encryption)
      04h 1   bit4-7:RFU?, bit0-3:Protocol version (01h)
      05h 1   Connection ID of master (3DS), value determined by master
      06h 1   Connection ID of slave (NFC adapter), value determined by slave
      07h 1   bit4-7:???, bit0-3: Operation code
      08h N-8 Payload (if any)

Operation codes:

      Code  Name                          Has payload     Direction
      00h = Layer 3 command               Yes             Master to slave
      01h = ???
      02h = ???
      03h = ???
      04h = ???
      05h = ???
      06h = ???
      07h = ???
      08h = ???
      09h = ???
      0Ah = Disconnect request            No              Master to slave
      0Bh = Disconnection acknowledgment  No              Slave to master
      0Ch = Handshake                     No              Master to slave
      0Dh = Handshake acknowledgement     No              Slave to master
      0Eh = ???
      0Fh = ???

NFC adapter will ignore packets whose protocol version is not 1. It will not even reply.
Connection identifier is a random byte the 3DS assigns to identify the connection should there be several connections in range at once. Slave devices must save this value from the initial handshake packet and use it for replies. The 3DS will also save the connection identifier byte of the slave which is also random. The 3DS must also ignore packets whose connection ID does not match.
Layer 3
Layer 3 is the payload of layer 2. A lot is unknown of this layer and thus a lot of assumptions were made in the following tables.
Layer 3 contains the following data:

      00h    bit4-7:Request identifier nibble, bit0-3: Always 01h
      01h    Slave/master identifier byte
      02h    Request type code upper byte
      03h    Request type code lower byte
      04h+   Payload (if any)

Request identifier nibble is incremented by 0x1 at every new request by the master, the same value for this byte is also sent by the slave in response to the request of the master
Slave/master identifier byte is 0x1 for a message from the master and 0x10 for a message from the slave
Request type codes

      Code    Request description                           Direction   Has payload
      0000h = ACK                                           Slave to master  Yes
      0003h = Get firmware version and battery level        Master to slave  No
      0004h = Firmware version and battery level            Slave to master  Yes
      0100h = Unknown, slave always responds with ACK       Master to slave  Yes
      0202h = Request to stop communication with NFC tag    Master to slave  No
      0204h = Get dumped data from NFC tag                  Master to slave  No
      0205h = Data from NFC tag                             Slave to master  Yes
      0206h = Request to start communication with NFC tag   Master to slave  Yes
      0207h = Request to write data to NFC tag              Master to slave  Yes

0000h
Acknowledgement message always send by slave. Payload always contains 000000AAh.
0004h
Payload contains firmware version and battery level of NFC adapter. Payload has a size of 6 bytes.

      00h    Upper or lower byte of version number, newest firmware is 01h
      01h    Upper or lower byte of version number, newest firmware is 06h
      02h    Padding byte? Always 00h
      03h    Padding byte? Always 00h
      04h    Battery level (03h=Full, 00h=Empty)
      05h    Padding byte? Always 00h

NFC reader LED already turns red when the battery level byte is 02h, this will also trigger a low battery level warning on the 3DS.
0100h
The purpose of this request by the master is unknown. Slave always responds with ACK. Payload of this request is always 0003E8AAh.
0205h
Payload contains data regarding NFC communication. The first byte of the payload means the following:

      Code   Description
      00h =  NFC communication is stopped as result of a 0202h request from master
      01h =  No NFC tag on top of the reader
      02h =  Busy dumping NFC tag
      03h =  NFC tag dump after write by master
      04h =  NFC tag fully dumped
      05h =  NFC tag dump after write by master
      07h =  NFC tag not a NTAG215 or contains no Amiibo compatible data
      08h =  NFC tag removed from reader

After the tag is written by the master and dumped again, the first few dumps start with 03h, this changes to 05h after a few dumps. The reason for this is unknown.
0206h
Request from master to start NFC communication. Payload always contains 19 00h padding bytes, followed by C80300393A737486000001h and another 26 00h padding bytes.
0207h
Request from master to write to NFC tag. The request packet already contains the desired data to be written to the tag. Payload start with two 00h padding bytes followed by the 7 ID bytes of the tag. These ID bytes are used by the NFC adapter to check if same Amiibo is placed on the NFC adapter again.
Samples
NFC handshake beacons:

      Layer 1 packet                          Layer 2 packet       Layer 3 packet
      A5 00 08 73 FE A5 C4 A4 2C A4 20 F5     9A 9D D6 3A 01 E8 00 0C         ?
      A5 00 08 D1 3E B7 7B B6 91 B6 9D 87     38 5D 66 45 01 EA 00 0C         ?
      A5 00 08 09 58 23 36 22 DA 22 D6 AE     E0 3B 2A 6E 01 EC 00 0C         ?
      A5 00 08 5E DD A4 A0 A5 4E A5 42 A8     B7 BE FA 7D 01 EE 00 0C         ?
      A5 00 08 BC 19 C6 37 C7 C7 C7 CB 8B     55 7A 7A 2E 01 F0 00 0C         ?
      A5 00 08 C9 15 F6 63 F7 91 F7 9D B2     20 76 3F 76 01 F2 00 0C         ?
      A5 00 08 6E 48 47 1A 46 EE 46 E2 C7     87 2B 29 52 01 F4 00 0C         ?
      A5 00 08 A2 8C E5 C3 E4 35 E4 39 74     4B EF 47 4F 01 F6 00 0C         ?
      A5 00 08 26 1C 07 10 06 E8 06 E4 64     CF 7F 21 0C 01 F8 00 0C         ?
      A5 00 08 7E 73 A2 3F A3 C5 A3 C9 FD     97 10 DC 4C 01 FA 00 0C         ?
      A5 00 08 75 00 F3 B8 F2 44 F2 48 63     9C 63 86 B8 01 FC 00 0C         ?
      A5 00 08 8D AC 0F D5 0E 2B 0E 27 72     64 CF 82 79 01 FE 00 0C         ?
      A5 00 08 A3 55 7C 53 7D 52 7D 5E B2     4A 36 DF 06 01 01 00 0C         ?
      A5 00 08 15 06 43 C0 42 C3 42 CF 85     FC 65 56 C6 01 03 00 0C         ?
      A5 00 08 66 E0 9A 17 9B 12 9B 1E A0     8F 83 FC F7 01 05 00 0C         ?
      A5 00 08 A4 35 09 97 08 90 08 9C 25     4D 56 AD A2 01 07 00 0C         ?
      A5 00 08 73 E2 BD AF BC A6 BC AA 60     9A 81 CE 4D 01 09 00 0C         ?
      A5 00 08 02 57 D7 B0 D6 BB D6 B7 28     EB 34 D5 E7 01 0B 00 0C         ?
      A5 00 08 0D 79 01 AA 00 A7 00 AB 22     E4 1A 0C D3 01 0D 00 0C         ?
      A5 00 08 14 91 04 B9 05 B6 05 BA B2     FD F2 10 28 01 0F 00 0C         ?
      A5 00 08 2C 86 B1 49 B0 58 B0 54 C0     C5 E5 9D CF 01 11 00 0C         ?
      A5 00 08 D5 1D DE DB DF C8 DF C4 F9     3C 7E 0B C6 01 13 00 0C         ?
      A5 00 08 AF 75 DE 5C DF 49 DF 45 9C     46 16 71 29 01 15 00 0C         ?
      A5 00 08 C8 E2 5B C6 5A D1 5A DD B5     21 81 93 24 01 17 00 0C         ?
      A5 00 08 9B 51 68 2D 69 34 69 38 41     72 32 F3 7C 01 19 00 0C         ?
      A5 00 08 13 7B 9F EF 9E F4 9E F8 32     FA 18 8C 94 01 1B 00 0C         ?
      A5 00 08 A7 62 02 9C 03 81 03 8D BD     4E 01 A5 FE 01 1D 00 0C         ?
      A5 00 08 39 06 94 36 95 29 95 25 09     D0 65 AD 30 01 1F 00 0C         ?
      A5 00 08 32 4C D7 C0 D6 E1 D6 ED 92     DB 2F E5 8C 01 21 00 0C         ?
      A5 00 08 83 BE F2 8F F3 AC F3 A0 B1     6A DD 71 31 01 23 00 0C         ?
      A5 00 08 83 5E A0 57 A1 72 A1 7E F0     6A 3D 23 09 01 25 00 0C         ?
      A5 00 08 6E C8 AD 69 AC 4E AC 42 D1     87 AB C3 A1 01 27 00 0C         ?
      A5 00 08 C7 33 A1 2C A0 05 A0 09 FC     2E 50 66 1F 01 29 00 0C         ?

External links
BCM2079x brief on Broadcom's website
Python scripts to sniff and spoof IR communication between the NFC reader and 3DS using an IrDA adapter

3DS I2C New3DS C-Stick and ZL/ZR-Buttons

I2C Bus/Device 2:54h - C-Stick and ZL/ZR-Buttons
This is a New3DS-only device (the Old3DS does have a similar add-on: Circle Pad Pro, connected to the infrared expansion port).
Oberseve that the bootrom doesn't initialized I2C_BUS2_CNTEX/SCL (especially CNTEX is required to have "Wait if SCL held low" enabled, else the C-stick replies are garbage).
The chip triggers ARM11 IRQ 68h (aka GPIO_DATA3.bit0=0) when moving the analog input or buttons. Reading the I2C data changes GPIO back to bit0=1.
Maybe this is the HUGE 44pin HF374 chip on button board, but if it's merely used for ZL/ZR and C-stick, why is that chip so huge?
I2C Read(Device+1,Byte0,Byte1,Byte2,Byte3,...)
Reading returns some kind of array, always starting with the status value in byte0, there is no need to write an index value before reading.
The array has useful info stored in first 4-7 bytes; and internal/garbage when reading further bytes, up to including something that looks like a CPU stack).

     The array entries are...
      00h       Status byte (80h..83h, or FFh) (power-up default=80h)
      01h       Button byte (00h=None, bit2=ZL, ?=ZR)
      02h       Analog X (00h=Center, -1xh=Left, +1xh=Right) ;\if enabled
      03h       Analog Y (00h=Center, -1xh=Down, +1xh=Up)    ;/
     Following bytes aren't needed, except for better 8bit X/Y resolution...
      04h       Fixed FFh
      05h       Analog X (00h=Center, -7xh=Left, +7xh=Right) ;\hires
      06h       Analog Y (00h=Center, -7xh=Down, +7xh=Up)    ;/
     Following bytes aren't actually useful...
      07h       Fixed 00h
      08h       Analog X (7xh=Center, FEh=Left, 00h=Right)   ;\unsigned/uncentered
      09h       Analog Y (7xh=Center, FEh=Down, 00h=Up)      ;/
      0Ah       Fixed 00h
      0Bh       Analog X (7xh=Center, FEh=Left, 00h=Right)   ;\same as [08h,09h]
      0Ch       Analog Y (7xh=Center, FEh=Down, 00h=Up)      ;/
      0Dh       Fixed 00h
      0Eh       Center X (7xh)  ;\auto-calibrating, with minor changes
      0Fh       Center Y (7xh)  ;/every some seconds
      10h       Fixed 00h
      11h..15h  Analog stuff
      16h       Flag (00h=Idle, 80h=Analog is/was recently touched)
      17h       Analog stuff
      18h       Flag (01h=Idle, 02h=Analog is/was recently left or down)
      19h       Analog stuff
     Following bytes can crash the chip upon reading (see below for details):
      1Ah       Flag (01h=Idle, 00h/02h=Analog is/was recently somehow moved)
      1Bh       Fixed 01h
      1Ch       Fixed 11h
      1Dh       Historic X (7xh)  ;\updated every some seconds
      1Eh       Historic Y (7xh)  ;/(same as center when idle)
      1Fh..27h  Fixed 00h-filled
      28h..2Ch  Fixed 07h,06h,06h,03h,01h
      2Dh..3Bh  Fixed 00h-filled
      3Ch       Fixed 01h
      3Dh..46h  Fixed 00h-filled
      47h..4Bh  Fixed 04h,C0h,00h,00h,03h
      4Ch       Whatever, changes
      4Dh       Flag (00h=Idle, 01h=Analog is/was recently moved)
      4Eh..54h  Fixed 01h,00h,06h,01h,A5h,00h,00h
      55h       Initially random xxh, becomes 00h/01h after button/analog
      56h       Flag 00h/10h/20h
      57h       Analog X (00h=Center, -1xh=Left, +1xh=Right) ;\same as [02h,03h]
      58h       Analog Y (00h=Center, -1xh=Down, +1xh=Up)    ;/
      59h       Analog
      5Ah       Analog
      5Bh..65h  Fixed 07h,00h,08h,04h,00h,00h,00h,09h,22h,71h,00h
      66h       Fast Timer (00h..1xh or so)
      67h       Fixed 15h ;maybe update period in ms, maybe limit for above timer?
      68h       Slow Timer (00h..08h, increasing)
      69h..6Ch  Fixed 09h,03h,00h,00h         ;maybe 09h is limit for above timer?
      6Dh       Up/down Timer (00h=Idle, increases-then-decreases upon analog move)
      6Eh..6Fh  Fixed 00h,00h
      70h       Button byte (00h=None, bit4=ZL, ?=ZR)
      71h       Usually 00h (sometimes shortly 10h or so)
      72h..74h  Fixed 00h-filled
      75h       Fixed FFh
      76h..7Bh  Fixed 00h-filled
      7Ch..82h  Fixed 7Fh,15h,09h,03h,54h,28h,10h
      83h..BDh  Fixed 00h-filled
     Following bytes might be CPU stack, first some bytes maybe random/garbage?
      BEh       7Ah,02h,1Dh,D9h,C7h,93h,31h,CCh,7Eh,A9h,BEh,86h,B3h,93h,6Dh,07h
      CEh       C7h,82h,E7h,00h,10h,00h,00h,10h,00h,10h,00h,10h,xxh,xxh,xxh,xxh
      DEh       xxh,xxh,xxh,xxh,xxh,xxh,xxh,xxh,xxh,xxh,xxh,xxh,xxh,xxh,xxh,xxh
     Following bytes seem to be used...
      EEh..xxxx Fixed FFh-filled (somewhat endless repeating)

Caution: The chip hangs after some seconds when reading more than 1Ah bytes; at that point all values get frozen (except, the "stack" at DDh..EDh does keep changing).
I2C Write(Device,Mode)
Writing does set a mode value, eg. write(Device,Mode). There is no need to write anything, the analog input and irq are automatically enabled on power-up. Effects for different mode values are:

      None      Default is Status=80h at power-up
      00h..51h  Set Status=80h
      52h..F4h  Set Status=81h
      F5h       Set Status=82h
      F6h..F9h  Set Status=83h
      FAh..FBh  Set Status=81h
      FCh..FDh  Set Status=FFh
      FEh       Set Status=80h with long 1 second I2C-clk-hold delay?
      FFh       Set Status=80h

Unknown what those mode/status values are meaning exactly. Maybe some can change polling interval or enable/disable interrupts, or maybe even do dangerous stuff like reflashing the firmware?
Some of the mode values disable the Analog bytes at index 02h/03h (causing that bytes to become always 00h, or maybe actually divide them by a large value, causing them to be always NEAR 00h?)
Trying to write more bytes (eg. write(Device,xx,yy) seems to apply the last written byte as mode value.
Operating System
The 3DS OS does access the C-stick via IR:RST service (probably for backwards compatibility with Circle Pad Pro, which was accessed via infrared).
The OS can reportedly change the update period in range of 10..21ms (aka 0Ah..15h), maybe via whatever I2C write.
The OS does reportedly return analog values in range -9Ch..+9Ch, maybe that are the I2C values scaled for Circle Pad Pro compatibility, or maybe a sum of multiple I2C values?

3DS I2C New3DS 16bit IO Expander (aka QTM)

TCA6416A 16bit IO Expander I2C Registers (I2C Bus/Device: 0:40h)

      00h Input Port 0                    (R) (reset: var, reads as 05h on New3DS)
      01h Input Port 1                    (R) (reset: var, reads as 00h on New3DS)
      02h Output Port 0                   (R/W) (reset: FFh)
      03h Output Port 1                   (R/W) (reset: FFh)
      04h Input Polarity Inversion 0      (R/W) (reset: 00h=normal)
      05h Input Polarity Inversion 1      (R/W) (reset: 00h=normal)
      06h Configuration (aka Direction) 0 (R/W) (reset: FFh=input)
      07h Configuration (aka Direction) 1 (R/W) (reset: FFh=input)
      08h..FFh Reserved                   (-)   (FFh's)

Port Usage in New3DS
Unknown. The IO Expander chip is close to the top-screen connectors, as such it does probably connect to components in the top-screen unit (which might include upper camera; or reportedly-existing head-tracking related stuff).
Unknown how a 16bit IO could do head-tracking, maybe it does opposite: receive the tracking RESULT from ARM side, and then OUTPUT something to parallax barrier?
Unknown if this can be reverse-engineered by people with broken top-screen connectors. Note: Below "usually set/cleared" assumes that the connector for upper backlight is broken, unknown if an intact console behaves the same.

      P0.0  Unknown (usually set)  ;DANGER: power-off when set to Output/Low
      P0.1  Unknown (usually 0)
      P0.2  Unknown (usually set)  ;DANGER: power-off when set to Output/Low
      P0.3  Unknown (usually 0)
      P0.4  Unknown (usually 0)
      P0.5  Unknown (usually 0)
      P0.6  Unknown (usually 0)
      P0.7  Unknown (usually 0)
      P1.0  Unknown (usually 0)
      P1.1  Unknown (usually 0)
      P1.2  Unknown (usually 0)
      P1.3  Unknown (usually 0)
      P1.4  Unknown (usually 0)
      P1.5  Unknown (usually 0)
      P1.6  Unknown (usually 0)
      P1.7  Unknown (usually 0)

00h - Input Port 0 (reset: var, reads as 05h on New3DS) (R)
01h - Input Port 1 (reset: var, reads as 00h on New3DS) (R)

      0-7  Input level (0=Low, 1=High; or vice-versa when using Polarity Inversion)

02h - Output Port 0 (reset: FFh) (R/W)
03h - Output Port 1 (reset: FFh) (R/W)

      0-7  Output level (0=Low, 1=High) (no effect if direction is Input)

04h - Polarity Inversion 0 (reset: 00h) (R/W)
05h - Polarity Inversion 1 (reset: 00h) (R/W)

      0-7  Polarity of Inputs (0=Normal, 1=Invert)

06h - Configuration 0 (reset: FFh) (R/W)
07h - Configuration 1 (reset: FFh) (R/W)

      0-7  Direction (0=Output, 1=Input)

Interrupt Pin
The IO Expander can trigger interrupts on any changes on any input pins. Unknown if the Interrupt signal is connected in New3DS.

3DS I2C Other/Unused/Debug Devices

Device 7 (Bus/device 1:40h) "i2c::DEB" Debug?
Device 8 (Bus/device 1:44h) "i2c::DEB" Debug?
Unknown.
Device 9 (Bus/device 2:A6h/D6h) "i2c::HID" Debug??
Unknown.
Device Address changed from A6h to D6h in 8.0.0-18.
Device 12 (Bus/device 2:A4h) "DebugPad"

      Register   Width   Description
      00h        21      DebugPad state.

This is the DebugPad device, see here.
Device 14 (Bus/device 2:A0h) "eeprom?"
Used by Cfg-sysmodule via the i2c::EEP service. This is presumably EEPROM going by the service name.
The Cfg-module code which loads the CCAL (nandro:/sys/{HWCAL0.dat/HWCAL1.dat}) file from NAND will load it from I2C instead, if a certain state flag is non-zero. Likewise for the function which writes CCAL to NAND. HMAC/hash verification after loading is skipped when the CCAL was loaded from I2C.
Bus/device 0:00h-0Eh - Mirrors to BPTWL for whatever reason
Bus/device 0:F0h-FEh - Mirrors to BPTWL for whatever reason
These are special broadcast/reserved device ids (defined in I2C protocol). The MCU chip apparently includes a hardware feature for decoding these IDs; and accidentally mirrors the BPTWL registers to them.
Bus/device 2:00h - Unknown, something responds here with ACK and FFh's
This is a special broadcast address (defined in I2C protocol). One (or more) of the devices on I2C Bus 2 do apparently respond to it... and perhaps even support some broadcast commands?

3DS Video

LCD Registers
These registers are used to configure the LCD screens.
3DS Video LCD Registers
Moreover, each screen is having an I2C-bus controller for further configuration.
3DS I2C LCD Screen Controllers
And, the MCU has several LCD/backlight enable flags... and a GPU flag?
GPU Memory and I/O Map
3DS GPU Memory and I/O Map
3DS GPU External Register List Summary
3DS GPU Internal Register List Summary
GPU External Registers (for memory transfers, and framebuf to LCD output)
3DS GPU External Registers - Memory Control/Status Registers
3DS GPU External Registers - Top/Bottom Screen and Framebuffer Setup
3DS GPU External Registers - Memfill and Memcopy
GPU Internal Registers (PICA200) (for drawing polygons to colorbuf/depthbuf)
3DS GPU Internal Register Overview
3DS GPU Internal Registers - Command Lists
3DS GPU Internal Registers - Finalize Interrupt registers
3DS GPU Internal Registers - Geometry Pipeline registers
3DS GPU Internal Registers - Shader registers
3DS GPU Internal Registers - Rasterizer registers
3DS GPU Internal Registers - Framebuffer registers
3DS GPU Internal Registers - Texturing registers (Generic Textures)
3DS GPU Internal Registers - Texturing registers (Procedural Texture)
3DS GPU Internal Registers - Texturing registers (Environment)
3DS GPU Internal Registers - Fragment Lighting registers
3DS GPU Internal Registers - Unknown/Unused/Undocumented Registers
3DS GPU Shader Instruction Set - Opcode Summary
3DS GPU Shader Instruction Set - Blurp
Misc notes...
3DS GPU Geometry Pipeline
3DS GPU Fragment Lighting
3DS GPU Pitfalls
3DS GPU Primitive Engine and Shaders
There is also some 3DS GPU open source driver called citro3d, but it's mostly higher level stuff and would require a lot of reverse engineering to extract to lower level functionality from it.
Sample Code
3DS GPU Triangle Drawing Sample Code
Camera and Video Data Conversion
3DS Video CAM Registers (Camera Input)
3DS Video Y2R Registers (YUV-to-RGBA Converter)
3DS Video L2B Registers (RGB-to-RGBA Converter) (New3DS)
3DS Video MVD Registers (Movie Decoder or so?) (New3DS)
3DS Video LGY Registers (Legacy GBA/NDS Video to Framebuffer)

3DS Video LCD Registers

This seems to be an interface between GPU video output and actual LCD screens. The registers allow to control backlight brightness and to set a forced blank color. Some other registers seem to be also affect backlight brightness (or pixel brightness?); and maybe some do affect internal voltages or internal backlight PWM timings?
The bootrom error screen initializes only a few of these registers (and leaves the others at their power-up defaults). Many of the uninitialized registers seem to have no effect on the visible picture, even when setting/clearing all bits; some of them affect the brightness of the pixels or backlight (but only if CtrlFlags.bit0=1).
General LCD Control Registers (ARM11 only)

      Physical  Size R/W       Name
      10202000h 4    00070007h reportedly Parallax barrier enable (uh, in 2x3bit?)
      10202004h 4    FFFFFFFFh Whatever, should be 0A390A39h
      10202008h 4    (R)       Whatever, readonly (R) (bit0=top screen mode?)
      1020200Ch 4    00010001h Video Disable Bits (bit0/16=top/bottom disable?)
      10202010h 4    00001F0Fh Whatever, usually 00000900h
      10202014h 4    00000001h Video Enable Bit (bit0)
      10202018h 1E8h (0)       Unused (0) ?
      10202200h 600h ...       LCD Configuration for Top Screen (see below)
      10202800h 200h (0)       Unused (0) ?
      10202A00h 600h ...       LCD Configuration for Bottom Screen (see below)
     (10203200h)40h  (0) uh??  reportedly LCD related, but actually DSP-mirror

LCD Configuration for Top/Bottom Screen

      Top/Bottom Addr     Size R/W
      10202200h/10202A00h 4    00000301h CtrlFlags
      10202204h/10202A04h 4    01FFFFFFh Forced Blank Color
      10202208h/10202A08h 8    (0)       Unused (0) ?
      10202210h/10202A10h 4    000003FFh ? (default=0)    ;\
      10202214h/10202A14h 4    000003FFh ? (default=3FFh) ; darker when all zero
      10202218h/10202A18h 4    000003FFh ? (default=0)    ; (if CtrlFlags.bit0=1)
      1020221Ch/10202A1Ch 4    000003FFh ? (default=3FFh) ;/
      10202220h/10202A20h 4    000001FFh ? (default=100h) ;-
      10202224h/10202A24h 4    000000FFh ? (default=0)    ;\
      10202228h/10202A28h 4    000000FFh ? (default=0)    ;
      1020222Ch/10202A2Ch 4    000000FFh ? (default=0)    ;/
      10202230h/10202A30h 4    001F000Fh ? (default=4)    ;-
      10202234h/10202A34h 4    (0)       Unused (0) ?
      10202238h/10202A38h 4    000000FFh Last same entry in 10202400h (FFh=AllSame)
      1020223Ch/10202A3Ch 4    000000FFh ? (default=FFh)
      10202240h/10202A40h 4    000003FFh Backlight ;based on register 244h.low10bit
      10202244h/10202A44h 4    FFFFF3FFh Backlight?;LSBs: backlight? MSBs=flags?
      10202248h/10202A48h 8    (0)       Unused (0) ?
      10202250h/10202A50h 4    00FFFFFFh ? (default=0)    ;\brighter if 2nd=FFFFFFh
      10202254h/10202A54h 4    00FFFFFFh ? (default=0)    ;/(if CtrlFlags.bit0=1)
      10202258h/10202A58h 8    (0)       Unused (0) ?
      10202260h/10202A60h 4    0000CCCCh ? (default=0C84h);\
      10202264h/10202A64h 4    (0)       Unused (0) ?     ;
      10202268h/10202A68h 4    0000CCCCh ? (default=840Ch); DITHER alike Y2R ?
      1020226Ch/10202A6Ch 4    (0)       Unused (0) ?     ;
      10202270h/10202A70h 4    0000CCCCh ? (default=48C0h);
      10202274h/10202A74h 4    (0)       Unused (0) ?     ;
      10202278h/10202A78h 4    0000CCCCh ? (default=C048h);
      1020227Ch/10202A7Ch 4    (0)       Unused (0) ?     ;/
      10202280h/10202A80h 24h  000000FFh ? (default=0)    ;-9 words (8th=brighter)
      102022A4h/10202AA4h 4Ch  (0)       Unused (0) ?
      102022F0h/10202AF0h 4    (-R-)     ? (R)            ;\initially 00h, but can
      102022F4h/10202AF4h 4    (-R-)     ? (R)            ; be FFh when screens
      102022F8h/10202AF8h 4    (-R-)     ? (R)            ;/are on?
      102022FCh/10202AFCh 4    (0)       Unused (0) ?
      10202300h/10202B00h 100h 00FFFFFFh New3DS only: LCD calibration array?
      10202400h/10202C00h 400h 000003FFh Backlight related array, used by bootrom

     ______________________________ General Control ______________________________

10202000h - Parallax barrier enable (uh, in 2x3bit?) (R/W)

      0-2    Unknown (0..7)
      3-15   Unused (0)
      16-18  Unknown (0..7)
      19-31  Unused (0)

No visible effect, at least not on bottom screen.
10202004h - Whatever, should be 0A390A39h (R/W)

      0-15   Unknown
      16-31  Unknown

Usually set to 0A390A39h. But there's no visible effect when set to 0 or FFFFFFFFh.
10202008h - Whatever, readonly (R)

      0      Indicates current horizontal resolution of top screen?
      1-31   Unknown or unused

1020200Ch - Video Disable Bits (R/W)

      0      Unknown (maybe same as bit16, for top screen?)
      1-15   Unused (0)
      16     Disable Bottom Screen (0=Normal/On, 1=Screen fades out)
      17-31  Unused (0)

10202010h - Whatever, usually 00000900h (R/W)

      0-3    Unknown (0..0Fh)
      4-7    Unused (0)
      8-12   Unknown (0..1Fh)
      13-31  Unused (0)

No visible effect. Power-up value is 00000900h. Bootrom doesn't change that setting.
10202014h - Video Enable Bit (R/W)

      0      Video enable (0=Off/Black, 1=On/Picture)
      1-31   Unused (0)

Bottom (and top?) screen goes black when off (though backlight is kept on).

     _____________________________ Top/Bottom Screen _____________________________

10202200h/10202A00h - CtrlFlags (R/W)

      0      Enables custom settings when set?
      1-7    Unused (0)
      8-9    Unknown (0..3)
      10-31  Unused (0)

Bit0 should be copied to 10202244h/10202A44h.bit17?
Bit0 seems to enable custom settings in 1020221xh/10202A1xh, 10202254h/10202A54h, and in the eighth word at 10202280h/10202A80h.
10202204h/10202A04h - Forced Blank Color (R/W)

      0-7    Blank Color Red     (00h..FFh)
      8-15   Blank Color Green   (00h..FFh)
      16-23  Blank Color Blue    (00h..FFh)
      24     Blank Color Enable  (0=Normal/Picture, 1=Force Blank Color)
      25-31  Unused (0)

The blank color overrides the whole picture (including the Screen Border area).
10202210h/10202A10h 4 000003FFh ? (default=0) ;\
10202214h/10202A14h 4 000003FFh ? (default=3FFh) ;
10202218h/10202A18h 4 000003FFh ? (default=0) ;
1020221Ch/10202A1Ch 4 000003FFh ? (default=3FFh) ;/

      0-9    Unknown (0..3FFh)
      10-31  Unused (0)

Screen gets darker when set to all zeroes (but only if CtrlFlags.bit0=1).
10202220h/10202A20h 4 000001FFh ? (default=100h) ;-

      0-8    Unknown (0..1FFh)
      9-31   Unused (0)

10202224h/10202A24h 4 000000FFh ? (default=0) ;\
10202228h/10202A28h 4 000000FFh ? (default=0) ;
1020222Ch/10202A2Ch 4 000000FFh ? (default=0) ;/

      0-7    Unknown (0..FFh)
      8-31   Unused (0)

10202230h/10202A30h 4 001F000Fh ? (default=4) ;-

      0-3    Unknown (0..0Fh)
      4-15   Unused (0)
      16-20  Unknown (0..1Fh)
      21-31  Unused (0)

10202238h/10202A38h 4 000000FFh Last same entry in 10202400h/10202C00h

      0-7    Index of last SAME entry in 10202400h/10202C00h (0..FFh) (FFh=AllSame)
      8-31   Unused (0)

1020223Ch/10202A3Ch 4 000000FFh ? (default=FFh)

      0-7    Unknown (0..FFh)
      8-31   Unused (0)

10202240h/10202A40h 4 000003FFh Backlight ;based on register 244h.low10bit

      0-9    Backlight related (0..3FFh)
      10-31  Unused (0)

10202244h/10202A44h 4 FFFFF3FFh Backlight?;LSBs: backlight? MSBs=flags?

      0-9    Backlight related? (0..3FFh)
      10-11  Unused (0)
      12-15  Unknown (should be 0 or 6, depending on MCU?)
      16     Unknown
      17     Unknown
      18-31  More unknown bits/values...

10202250h/10202A50h 4 00FFFFFFh ? (default=0)
10202254h/10202A54h 4 00FFFFFFh ? (default=0)

      0-23   Unknown (0..FFFFFFh)
      24-31  Unused (0)

Two 24bit values. Screen gets brighter when setting the SECOND value to FFFFFFh (but only if CtrlFlags.bit0=1).
10202260h/10202A60h 4 0000CCCCh ? (default=0C84h)
10202268h/10202A68h 4 0000CCCCh ? (default=840Ch)
10202270h/10202A70h 4 0000CCCCh ? (default=48C0h)
10202278h/10202A78h 4 0000CCCCh ? (default=C048h)

      0-15   Unknown (R/W Mask CCCCh)
      16-31  Unused (0)

DITHER alike Y2R?
10202280h/10202A80h 24h 000000FFh ? (default=0) ;-(9 words)

      0-7    Unknown (0..FFh)
      8-31   Unused (0)

Unknown... 9 words (with 8bit used each) at 10202280h/10202A80h and up.
Screen gets brighter when setting the EIGHTH value to FFh (but only if CtrlFlags.bit0=1).
102022F0h/10202AF0h - Readonly (R)
102022F4h/10202AF4h - Readonly (R)
102022F8h/10202AF8h - Readonly (R)

      0-xx   Unknown (initially 00h, but can be FFh when screens are on?)  (R)
      xx-31  Unused (0)

10202300h/10202B00h 100h 00FFFFFFh New3DS only: LCD calibration? (40 words)

      0-23   Unknown (0..FFFFFFh) (initially random)
      24-31  Unused (0)

40h words (100h bytes) at 10202300h/10202B00h and up.
Reportedly initialized from nand:/ro/sys/HWCAL0.dat offset 77Ch.
On Old3DS: Unused (0)
On New3DS: R/W (even in Old3DS mode)
Bootrom doesn't init these values (so they are apparently initially disabled somewhere).
10202400h/10202C00h 400h 000003FFh Whatever array, used by bootrom!!!

      0-9    Unknown (0..3FFh) (initially random)
      10-31  Unused (0)

100h words (400h bytes) at 10202400h/10202C00h and up.
The bootrom error screen has some complicated function that initializes this array with scaled/interpolated values, somehow related to backlight level and screen type; although, with the used parameters... it seems to be just settings all 100h table entries to the same value.
Alongsides, the number of leading entries with SAME value should be stored in register 10202238h/10202A38h (ie. store N-1 if the first N table entries are all same).

3DS GPU Memory and I/O Map

GPU Overall Memory and I/O Map
All registers at 10202xxxh, 10400xxxh, 10401xxxh can be read/written by ARM11 opcodes, the 10401xxxh registers can be also written via command numbers 0000h..03FFh in PICA command lists.

      10202000h 18h     LCD Config/flags                               ;\
      10202018h 1E8h    Unused (0) ?                                   ;
      10202200h 600h    LCD Configuration for Top Screen               ; LCD
      10202800h 200h    Unused (0) ?                                   ;
      10202A00h 600h    LCD Configuration for Bottom Screen            ;/
      10400000h 10h     GPU Memory Control/Status Registers (part 1)   ;\
      10400010h 10h     DMA Memory Fill 0 DMA "PSC0"                   ;
      10400020h 10h     DMA Memory Fill 1 DMA "PSC1"                   ;
      10400030h D0h     GPU Memory Control/Status Registers (part 2)   ; External
      10400100h 300h    Unused (mirrors of above 100h bytes)           ;
      10400400h 100h    LCD Framebuffer Setup "PDC0" (top screen)      ;
      10400500h 100h    LCD Framebuffer Setup "PDC1" (bottom screen)   ;
      10400600h 200h    Unknown/DANGER (hangs when reading?)           ;
      10400800h 400h    Unknown/Unused (data abort)                    ;
      10400C00h 100h    DMA Memory Copy DMA Transfer Engine "DMA"      ;
      10400D00h 300h    Unused (mirrors of above 100h bytes)           ;/
      10401000h 1000h   Internal Command Registers PICA(0000h..03FFh)  ;-Internal
      10402000h 2000h   Unused (data abort)
      10404000h 1C000h  Write-only mirrors of above 4000h bytes (read=data abort)
      18000000h 300000h VRAM area, usually VRAM_A (3Mbyte)
      18300000h 300000h VRAM area, usually VRAM_B (3Mbyte)
      18600000h 600000h VRAM area, usually empty/zerofilled (6Mbyte)

Apart from VRAM, the GPU can also access other memory like FCRAM, AXI, QTM (but that's most probably slower; and may be problematic when using virtual memory allocation on ARM11 side).

3DS GPU External Register List Summary

GPU Memory Control/Status Registers - Misc

      10400000h  GPU_FIXED_00010002h (always 00010002h, maybe ChipID/Version?) (R)
      10400004h  GPU_VRAM_CNT (reset=0, bootrom=300h) (R/W)
      10400008h  GPU_UNKNOWN_2BIT (R/W)
      1040000Ch  Unused (0)

GPU Memory Fill Unit 0 and 1

      10400010h  GPU_MEMFILL_DST_ADDR0     ;\
      10400014h  GPU_MEMFILL_DST_END0      ; GPU_MEMFILL_0
      10400018h  GPU_MEMFILL_DATA0         ;
      1040001Ch  GPU_MEMFILL_CNT0          ;/
      10400020h  GPU_MEMFILL_DST_ADDR1     ;\
      10400024h  GPU_MEMFILL_DST_END1      ; GPU_MEMFILL_1
      10400028h  GPU_MEMFILL_DATA1         ;
      1040002Ch  GPU_MEMFILL_CNT1          ;/

GPU Memory Control/Status Registers - Misc

      10400030h  GPU_VRAM_POWER (R/W)
      10400034h  GPU_STAT_IRQ_FLAGS (R)
      10400038h  GPU_STAT_SOMETHING (R)
      1040003Ch  GPU_MAKE_SOMETHING (R/W)
      10400040h  GPU_STAT_BACKLIGHT_OR_SO (R)
      10400044h  GPU_UNKNOWN_CAN_BE_7F80h (R)
      10400048h  GPU_UNKNOWN_32BIT (reset=0) (R/W)
      1040004Ch  Unused (0)
      10400050h  GPU_TIMING_CNT1 (R/W=FFFFFFFFh) (res=1111EF00h) ;init=22221200h
      10400054h  GPU_TIMING_CNT2 (R/W=FFFFFFFFh) (res=00000112h) ;init=00000FF2h
      10400058h  GPU_STAT_BUSY_FLAGS (R)
      1040005Ch  GPU_MAKE_WHATEVER_MESS (R/W)
      10400060h  GPU_STAT_WHATEVER_MESS (R)
      10400064h  GPU_UNKNOWN_1BIT (R/W=00000001h) (res=0)
      10400068h  GPU_UNKNOWN_INITIALLY_00A80000h (res=00A80000h) (R/W)
      1040006Ch  Unused (0)

GPU Memory Control/Status Registers - Read-only memory traffic counters...

      10400070h  GPU_STAT_TOTAL_NON_VRAM_READS      ;\Non-VRAM (eg. AXI,QTM,FCRAM)
      10400074h  GPU_STAT_TOTAL_NON_VRAM_WRITES     ;/
      10400078h  GPU_STAT_TOTAL_VRAM_A_READS        ;\1st 3Mbyte VRAM block
      1040007Ch  GPU_STAT_TOTAL_VRAM_A_WRITES       ;/
      10400080h  GPU_STAT_TOTAL_VRAM_B_READS        ;\2nd 3Mbyte VRAM block
      10400084h  GPU_STAT_TOTAL_VRAM_B_WRITES       ;/
      10400088h  GPU_STAT_POLYGON_ARRAY_READS       ;-ATTR_BUF, INDEX_LIST
      1040008Ch  GPU_STAT_POLYGON_TEXTURE_READS     ;-cache misses only
      10400090h  GPU_STAT_POLYGON_DEPTHBUFFER_READS
      10400094h  GPU_STAT_POLYGON_DEPTHBUFFER_WRITES
      10400098h  GPU_STAT_POLYGON_COLORBUFFER_READS
      1040009Ch  GPU_STAT_POLYGON_COLORBUFFER_WRITES
      104000A0h  GPU_STAT_LCD_UPPER_SCREEN_READS    ;\for both left+right buffer
      104000A4h  GPU_STAT_LCD_LOWER_SCREEN_READS    ;/
      104000A8h  GPU_STAT_MEMCOPY_SRC_READS         ;\GPU_MEMCOPY
      104000ACh  GPU_STAT_MEMCOPY_DST_WRITES        ;/
      104000B0h  GPU_STAT_MEMFILL_0_DST_WRITES      ;\GPU_MEMFILL 0/1
      104000B4h  GPU_STAT_MEMFILL_1_DST_WRITES      ;/
      104000B8h  GPU_STAT_CPU_READS_FROM_VRAM_A_B   ;\counted by GPU because the
      104000BCh  GPU_STAT_CPU_WRITES_TO_VRAM_A_B    ;/GPU must forward vram to cpu

GPU Memory Control/Status Registers - Misc

      104000C0h  GPU_BACKLIGHT_OR_SO_1 (reset=20000000h) (R/W)
      104000C4h  GPU_BASE_ADDR_VRAM_A (reset=18000000h) (R/W)
      104000C8h  GPU_BASE_ADDR_VRAM_B (reset=18300000h) (R/W)
      104000CCh  GPU_BACKLIGHT_OR_SO_2 (reset=20000000h) (R/W)
      104000D0h  GPU_UNKNOWN_4BIT (reset=0) (R/W)
      104000D4h  Unused (2Ch bytes, zerofilled)
      10400100h  Unused (300h bytes, mirrors of above 100h bytes)

GPU Display Contollers

      10400400h  LCD Framebuffer Setup "PDC0" (100h bytes) (top screen)
      10400500h  LCD Framebuffer Setup "PDC1" (100h bytes) (bottom screen)
      10400600h  Unused? (200h bytes, Unknown/DANGER, hangs when reading?)
      10400800h  Unused? (400h bytes, Unknown/Unused, data abort)

GPU Memory Copy Unit

      10400C00h  GPU_MEMCOPY_SRC_ADDR - Memcopy Input physical address (R/W)
      10400C04h  GPU_MEMCOPY_DST_ADDR - Memcopy Output physical address (R/W)
      10400C08h  GPU_MEMCOPY_DISPLAY_SIZE - DisplayTransfer width/height (R/W)
      10400C0Ch  GPU_MEMCOPY_DISPLAY_GAP - DisplayTransfer Input height+gap (R/W)
      10400C10h  GPU_MEMCOPY_FLAGS - Memcopy Transfer flags (R/W)
      10400C14h  GPU_MEMCOPY_UNKNOWN_21BIT - Memcopy (R/W)
      10400C18h  GPU_MEMCOPY_CNT - Memcopy Start/Busy (R/W)
      10400C1Ch  GPU_MEMCOPY_REMAIN_IRQ - Memcopy Remain IRQ (R/W)
      10400C20h  GPU_MEMCOPY_TEX_SIZE - TextureCopy total amount
      10400C24h  GPU_MEMCOPY_TEX_SRC_WIDTH - TextureCopy input line width/gap
      10400C28h  GPU_MEMCOPY_TEX_DST_WIDTH - TextureCopy output line width/gap
      10400C2Ch  GPU_MEMCOPY_UNKNOWN_FLAG - Memcopy Unknown (R/W)
      10400C30h  Unused (D0h bytes, zerofilled)
      10400D00h  Unused (300h bytes, mirrors of above 100h bytes)

3DS GPU Internal Register List Summary

3DS GPU Internal Registers - Finalize Interrupt registers

      10401000h+i   - PICA(N/A)       - GPUREG_IRQ_ACK(0..63) (R/W)
      10401040h+i   - PICA(0010h+i/4) - GPUREG_IRQ_REQ(0..63) (R/W)
      10401080h+i   - PICA(N/A)       - GPUREG_IRQ_CMP(0..63) (R/W)
      104010C0h     - PICA(N/A)       - GPUREG_IRQ_MASK_LOW (R/W)
      104010C4h     - PICA(N/A)       - GPUREG_IRQ_MASK_HIGH (R/W)
      104010C8h     - PICA(N/A)       - GPUREG_IRQ_STAT_LOW (R)
      104010CCh     - PICA(N/A)       - GPUREG_IRQ_STAT_HIGH (R)
      104010D0h     - PICA(N/A)       - GPUREG_IRQ_AUTOSTOP (R/W)
      104010D4h     - PICA(N/A)       - GPUREG_FIXED_00010002h (R)

3DS GPU Internal Registers - Rasterizer registers

      10401100h     - PICA(0040h)   - GPUREG_FACECULLING_CONFIG (R/W)
      10401104h     - PICA(0041h)   - GPUREG_VIEWPORT_V_SCALE (R/W)
      10401108h     - PICA(0042h)   - GPUREG_VIEWPORT_V_STEP (R/W)
      1040110Ch     - PICA(0043h)   - GPUREG_VIEWPORT_H_SCALE (R/W)
      10401110h     - PICA(0044h)   - GPUREG_VIEWPORT_H_STEP (R/W)
      10401114h     - PICA(0045h)   - GPUREG_undoc_10401114h (R/W=00FFFFFFh)
      10401118h     - PICA(0046h)   - GPUREG_undoc_10401118h (R/W=00FFFFFFh)
      1040111Ch     - PICA(0047h)   - GPUREG_FRAGOP_CLIP (R/W)
      10401120h+i*4 - PICA(0048h+i) - GPUREG_FRAGOP_CLIP_DATAi (i=0..3) (R/W)
      10401130h     - PICA(004Ch)   - GPUREG_undoc_10401130h (R/W=00000001h)
      10401134h     - PICA(004Dh)   - GPUREG_DEPTHMAP_SCALE (R/W)
      10401138h     - PICA(004Eh)   - GPUREG_DEPTHMAP_OFFSET (R/W)
      1040113Ch     - PICA(004Fh)   - GPUREG_SH_OUTMAP_TOTAL (R/W)
      10401140h+i*4 - PICA(0050h+i) - GPUREG_SH_OUTMAP_Oi (i=0..6) (R/W)
      10401160h     - PICA(0058h)   - GPUREG_undoc_10401160h (R/W=00000101h)
      10401164h     - PICA(0059h)   - GPUREG_undoc_10401164h (R/W=00000001h)
      10401168h     - PICA(005Ah)   - GPUREG_STAT_NUM_VERTICES_RECEIVED (R)
      1040116Ch     - PICA(005Bh)   - GPUREG_STAT_NUM_TRIANGLES_RECEIVED (R)
      10401170h     - PICA(005Ch)   - GPUREG_STAT_NUM_TRIANGLES_DISPLAYED (R)
      10401180h     - PICA(0060h)   - GPUREG_undoc_10401180h (R/W=00000301h)
      10401184h     - PICA(0061h)   - GPUREG_EARLYDEPTH_FUNC (R/W)
      10401188h     - PICA(0062h)   - GPUREG_EARLYDEPTH_TEST1 (R/W)
      1040118Ch     - PICA(0063h)   - GPUREG_EARLYDEPTH_CLEAR (W)
      10401190h     - PICA(0064h)   - GPUREG_SH_OUTATTR_MODE (R/W)
      10401194h     - PICA(0065h)   - GPUREG_SCISSORTEST_MODE (R/W)
      10401198h     - PICA(0066h)   - GPUREG_SCISSORTEST_POS1 (R/W)
      1040119Ch     - PICA(0067h)   - GPUREG_SCISSORTEST_POS2 (R/W)
      104011A0h     - PICA(0068h)   - GPUREG_VIEWPORT_XY (R/W)
      104011A4h     - PICA(0069h)   - GPUREG_undoc_104011A4h (R/W=FFFF0001h)
      104011A8h     - PICA(006Ah)   - GPUREG_EARLYDEPTH_DATA (R/W)
      104011ACh     - PICA(006Bh)   - GPUREG_undoc_104011ACh (R/W=00000FFFh)
      104011B0h     - PICA(006Ch)   - GPUREG_undoc_104011B0h (hangs when reading)
      104011B4h     - PICA(006Dh)   - GPUREG_DEPTHMAP_ENABLE (R/W)
      104011B8h     - PICA(006Eh)   - GPUREG_RENDERBUFFER_DIM_1 (R/W)
      104011BCh     - PICA(006Fh)   - GPUREG_SH_OUTATTR_CLOCK (R/W)

3DS GPU Internal Registers - Texturing registers (Generic Textures)

      10401200h     - PICA(0080h)   - GPUREG_TEXUNIT_CONFIG (R/W)        ;-CONFIG
      10401204h     - PICA(0081h)   - GPUREG_TEXUNIT0_BORDER_COLOR (R/W) ;\
      10401208h     - PICA(0082h)   - GPUREG_TEXUNIT0_DIM (R/W)          ;
      1040120Ch     - PICA(0083h)   - GPUREG_TEXUNIT0_PARAM (R/W)        ; UNIT0
      10401210h     - PICA(0084h)   - GPUREG_TEXUNIT0_LOD (R/W)          ;
      10401214h     - PICA(0085h)   - GPUREG_TEXUNIT0_ADDR1 (R/W)        ;
      10401218h     - PICA(0086h)   - GPUREG_TEXUNIT0_ADDR2 (R/W)        ;
      1040121Ch     - PICA(0087h)   - GPUREG_TEXUNIT0_ADDR3 (R/W)        ;
      10401220h     - PICA(0088h)   - GPUREG_TEXUNIT0_ADDR4 (R/W)        ;
      10401224h     - PICA(0089h)   - GPUREG_TEXUNIT0_ADDR5 (R/W)        ;
      10401228h     - PICA(008Ah)   - GPUREG_TEXUNIT0_ADDR6 (R/W)        ;
      1040122Ch     - PICA(008Bh)   - GPUREG_TEXUNIT0_SHADOW (R/W)       ;
      10401230h     - PICA(008Ch)   - GPUREG_undoc_10401230h (R/W=FFFF00FFh)
      10401234h     - PICA(008Dh)   - GPUREG_undoc_10401234h (R/W=000000FFh)
      10401238h     - PICA(008Eh)   - GPUREG_TEXUNIT0_TYPE (R/W)         ;/
      1040123Ch     - PICA(008Fh)   - GPUREG_LIGHTING_ENABLE (R/W)       ;-
      10401244h     - PICA(0091h)   - GPUREG_TEXUNIT1_BORDER_COLOR (R/W) ;\
      10401248h     - PICA(0092h)   - GPUREG_TEXUNIT1_DIM (R/W)          ;
      1040124Ch     - PICA(0093h)   - GPUREG_TEXUNIT1_PARAM (R/W)        ; UNIT1
      10401250h     - PICA(0094h)   - GPUREG_TEXUNIT1_LOD (R/W)          ;
      10401254h     - PICA(0095h)   - GPUREG_TEXUNIT1_ADDR (R/W)         ;
      10401258h     - PICA(0096h)   - GPUREG_TEXUNIT1_TYPE (R/W)         ;/
      10401264h     - PICA(0099h)   - GPUREG_TEXUNIT2_BORDER_COLOR (R/W) ;\
      10401268h     - PICA(009Ah)   - GPUREG_TEXUNIT2_DIM (R/W)          ;
      1040126Ch     - PICA(009Bh)   - GPUREG_TEXUNIT2_PARAM (R/W)        ; UNIT2
      10401270h     - PICA(009Ch)   - GPUREG_TEXUNIT2_LOD (R/W)          ;
      10401274h     - PICA(009Dh)   - GPUREG_TEXUNIT2_ADDR (R/W)         ;
      10401278h     - PICA(009Eh)   - GPUREG_TEXUNIT2_TYPE (R/W)         ;/

3DS GPU Internal Registers - Texturing registers (Procedural Texture)

      104012A0h     - PICA(00A8h)   - GPUREG_TEXUNIT3_PROCTEX0 (R/W)
      104012A4h     - PICA(00A9h)   - GPUREG_TEXUNIT3_PROCTEX1 (R/W)
      104012A8h     - PICA(00AAh)   - GPUREG_TEXUNIT3_PROCTEX2 (R/W)
      104012ACh     - PICA(00ABh)   - GPUREG_TEXUNIT3_PROCTEX3 (R/W)
      104012B0h     - PICA(00ACh)   - GPUREG_TEXUNIT3_PROCTEX4 (R/W)
      104012B4h     - PICA(00ADh)   - GPUREG_TEXUNIT3_PROCTEX5_LOW (R/W)
      104012B8h     - PICA(00AEh)   - GPUREG_TEXUNIT3_PROCTEX5_HIGH (R/W)
      104012BCh     - PICA(00AFh)   - GPUREG_PROCTEX_LUT_INDEX (R/W)
      104012C0h+i*4 - PICA(00B0h+i) - GPUREG_PROCTEX_LUT_DATA(0..7) (R/W)

3DS GPU Internal Registers - Texturing registers (Environment)

      10401300h     - PICA(00C0h)   - GPUREG_TEXENV0_SOURCE (R/W)       ;\
      10401304h     - PICA(00C1h)   - GPUREG_TEXENV0_OPERAND (R/W)      ;
      10401308h     - PICA(00C2h)   - GPUREG_TEXENV0_COMBINER (R/W)     ; ENV0
      1040130Ch     - PICA(00C3h)   - GPUREG_TEXENV0_COLOR (R/W)        ;
      10401310h     - PICA(00C4h)   - GPUREG_TEXENV0_SCALE (R/W)        ;/
      1040131Ch     - PICA(00C7h)   - GPUREG_undoc_1040131Ch (R/W=00000007h)
      10401320h     - PICA(00C8h)   - GPUREG_TEXENV1_SOURCE (R/W)       ;\
      10401324h     - PICA(00C9h)   - GPUREG_TEXENV1_OPERAND (R/W)      ;
      10401328h     - PICA(00CAh)   - GPUREG_TEXENV1_COMBINER (R/W)     ; ENV1
      1040132Ch     - PICA(00CBh)   - GPUREG_TEXENV1_COLOR (R/W)        ;
      10401330h     - PICA(00CCh)   - GPUREG_TEXENV1_SCALE (R/W)        ;/
      10401340h     - PICA(00D0h)   - GPUREG_TEXENV2_SOURCE (R/W)       ;\
      10401344h     - PICA(00D1h)   - GPUREG_TEXENV2_OPERAND (R/W)      ;
      10401348h     - PICA(00D2h)   - GPUREG_TEXENV2_COMBINER (R/W)     ; ENV2
      1040134Ch     - PICA(00D3h)   - GPUREG_TEXENV2_COLOR (R/W)        ;
      10401350h     - PICA(00D4h)   - GPUREG_TEXENV2_SCALE (R/W)        ;/
      10401360h     - PICA(00D8h)   - GPUREG_TEXENV3_SOURCE (R/W)       ;\
      10401364h     - PICA(00D9h)   - GPUREG_TEXENV3_OPERAND (R/W)      ;
      10401368h     - PICA(00DAh)   - GPUREG_TEXENV3_COMBINER (R/W)     ; ENV3
      1040136Ch     - PICA(00DBh)   - GPUREG_TEXENV3_COLOR (R/W)        ;
      10401370h     - PICA(00DCh)   - GPUREG_TEXENV3_SCALE (R/W)        ;/
      10401380h     - PICA(00E0h)   - GPUREG_TEXENV_UPDATE_BUFFER (R/W)
      10401384h     - PICA(00E1h)   - GPUREG_FOG_COLOR (R/W)
      10401388h     - PICA(00E2h)   - GPUREG_undoc_10401388h (R/W=0000FFFFh)
      1040138Ch     - PICA(00E3h)   - GPUREG_undoc_1040138Ch (R/W=0000FFFFh)
      10401390h     - PICA(00E4h)   - GPUREG_GAS_ATTENUATION (R/W)
      10401394h     - PICA(00E5h)   - GPUREG_GAS_ACCMAX (R/W)
      10401398h     - PICA(00E6h)   - GPUREG_FOG_LUT_INDEX (R/W)
      104013A0h+i*4 - PICA(00E8h+i) - GPUREG_FOG_LUT_DATA(0..7) (R/W)
      104013C0h     - PICA(00F0h)   - GPUREG_TEXENV4_SOURCE (R/W)       ;\
      104013C4h     - PICA(00F1h)   - GPUREG_TEXENV4_OPERAND (R/W)      ;
      104013C8h     - PICA(00F2h)   - GPUREG_TEXENV4_COMBINER (R/W)     ; ENV4
      104013CCh     - PICA(00F3h)   - GPUREG_TEXENV4_COLOR (R/W)        ;
      104013D0h     - PICA(00F4h)   - GPUREG_TEXENV4_SCALE (R/W)        ;/
      104013E0h     - PICA(00F8h)   - GPUREG_TEXENV5_SOURCE (R/W)       ;\
      104013E4h     - PICA(00F9h)   - GPUREG_TEXENV5_OPERAND (R/W)      ;
      104013E8h     - PICA(00FAh)   - GPUREG_TEXENV5_COMBINER (R/W)     ; ENV5
      104013ECh     - PICA(00FBh)   - GPUREG_TEXENV5_COLOR (R/W)        ;
      104013F0h     - PICA(00FCh)   - GPUREG_TEXENV5_SCALE (R/W)        ;/
      104013F4h     - PICA(00FDh)   - GPUREG_TEXENV_BUFFER_COLOR (R/W)  ;-

3DS GPU Internal Registers - Framebuffer registers

      10401400h     - PICA(0100h)   - GPUREG_COLOR_OPERATION (R/W)
      10401404h     - PICA(0101h)   - GPUREG_BLEND_FUNC (R/W)
      10401408h     - PICA(0102h)   - GPUREG_LOGIC_OP (R/W)
      1040140Ch     - PICA(0103h)   - GPUREG_BLEND_COLOR (R/W)
      10401410h     - PICA(0104h)   - GPUREG_FRAGOP_ALPHA_TEST (R/W)
      10401414h     - PICA(0105h)   - GPUREG_STENCIL_TEST (R/W)
      10401418h     - PICA(0106h)   - GPUREG_STENCIL_OP (R/W)
      1040141Ch     - PICA(0107h)   - GPUREG_DEPTH_COLOR_MASK (R/W)
      10401434h     - PICA(010Dh)   - GPUREG_undoc_10401434h (R/W=00000001h)
      10401438h     - PICA(010Eh)   - GPUREG_undoc_10401438h (R/W=FFFFFFFFh)
      1040143Ch     - PICA(010Fh)   - GPUREG_undoc_1040143Ch (R/W=FFFFFFFFh)
      10401440h     - PICA(0110h)   - GPUREG_RENDERBUFFER_INVALIDATE (forget) (W)
      10401444h     - PICA(0111h)   - GPUREG_RENDERBUFFER_FLUSH (writeback) (W)
      10401448h     - PICA(0112h)   - GPUREG_COLORBUFFER_READING (R/W)
      1040144Ch     - PICA(0113h)   - GPUREG_COLORBUFFER_WRITING (R/W)
      10401450h     - PICA(0114h)   - GPUREG_DEPTHBUFFER_READING (R/W)
      10401454h     - PICA(0115h)   - GPUREG_DEPTHBUFFER_WRITING (R/W)
      10401458h     - PICA(0116h)   - GPUREG_DEPTHBUFFER_FORMAT (R/W)
      1040145Ch     - PICA(0117h)   - GPUREG_COLORBUFFER_FORMAT (R/W)
      10401460h     - PICA(0118h)   - GPUREG_EARLYDEPTH_TEST2 (R/W)
      10401464h     - PICA(0119h)   - GPUREG_undoc_10401464h (R/W=FFFFFFFFh)
      10401468h     - PICA(011Ah)   - GPUREG_undoc_10401468h (R/W=FFFFFFFFh)
      1040146Ch     - PICA(011Bh)   - GPUREG_RENDERBUFFER_BLOCK32 (R/W)
      10401470h     - PICA(011Ch)   - GPUREG_DEPTHBUFFER_LOC (R/W)
      10401474h     - PICA(011Dh)   - GPUREG_COLORBUFFER_LOC (R/W)
      10401478h     - PICA(011Eh)   - GPUREG_RENDERBUFFER_DIM_0 (R/W)
      1040147Ch     - PICA(011Fh)   - GPUREG_undoc_1040147Ch (R/W=7FFFFFFFh)
      10401480h     - PICA(0120h)   - GPUREG_GAS_LIGHT_XY - Planar Shading (R/W)
      10401484h     - PICA(0121h)   - GPUREG_GAS_LIGHT_Z - View Shading (R/W)
      10401488h     - PICA(0122h)   - GPUREG_GAS_LIGHT_Z_COLOR (R/W)
      1040148Ch     - PICA(0123h)   - GPUREG_GAS_LUT_INDEX (W)
      10401490h     - PICA(0124h)   - GPUREG_GAS_LUT_DATA (R/W)
      10401494h     - PICA(0125h)   - GPUREG_undoc_10401494h (R/W=0000FFFFh)
      10401498h     - PICA(0126h)   - GPUREG_GAS_DELTAZ_DEPTH (R/W)
      104014C0h     - PICA(0130h)   - GPUREG_FRAGOP_SHADOW (R/W)
      104014FCh     - PICA(013Fh)   - GPUREG_undoc_104014FCh (R/W=0000000Fh)

3DS GPU Internal Registers - Fragment Lighting registers

      10401500h+i*40h - PICA(0140h+10h*(0..7)) - GPUREG_LIGHTi_SPECULAR0 (R/W)
      10401504h+i*40h - PICA(0141h+10h*(0..7)) - GPUREG_LIGHTi_SPECULAR1 (R/W)
      10401508h+i*40h - PICA(0142h+10h*(0..7)) - GPUREG_LIGHTi_DIFFUSE (R/W)
      1040150Ch+i*40h - PICA(0143h+10h*(0..7)) - GPUREG_LIGHTi_AMBIENT (R/W)
      10401510h+i*40h - PICA(0144h+10h*(0..7)) - GPUREG_LIGHTi_VECTOR_LOW (R/W)
      10401514h+i*40h - PICA(0145h+10h*(0..7)) - GPUREG_LIGHTi_VECTOR_HIGH (R/W)
      10401518h+i*40h - PICA(0146h+10h*(0..7)) - GPUREG_LIGHTi_SPOTDIR_LOW (R/W)
      1040151Ch+i*40h - PICA(0147h+10h*(0..7)) - GPUREG_LIGHTi_SPOTDIR_HIGH (R/W)
      10401524h+i*40h - PICA(0149h+10h*(0..7)) - GPUREG_LIGHTi_CONFIG (R/W)
      10401528h+i*40h - PICA(014Ah+10h*(0..7)) - GPUREG_LIGHTi_ATTENUATION_BIAS
      1040152Ch+i*40h - PICA(014Bh+10h*(0..7)) - GPUREG_LIGHTi_ATTENUATION_SCALE
      10401700h       - PICA(01C0h)   - GPUREG_LIGHTING_AMBIENT (R/W)
      10401708h       - PICA(01C2h)   - GPUREG_LIGHTING_NUM_LIGHTS (R/W)
      1040170Ch       - PICA(01C3h)   - GPUREG_LIGHTING_CONFIG0 (R/W)
      10401710h       - PICA(01C4h)   - GPUREG_LIGHTING_CONFIG1 (R/W)
      10401714h       - PICA(01C5h)   - GPUREG_LIGHTING_LUT_INDEX (R/W)
      10401718h       - PICA(01C6h)   - GPUREG_LIGHTING_DISABLE (R/W)
      10401720h+i*4   - PICA(01C8h+i) - GPUREG_LIGHTING_LUT_DATA(0..7) (R/W)
      10401740h       - PICA(01D0h)   - GPUREG_LIGHTING_LUTINPUT_ABS (R/W)
      10401744h       - PICA(01D1h)   - GPUREG_LIGHTING_LUTINPUT_SELECT (R/W)
      10401748h       - PICA(01D2h)   - GPUREG_LIGHTING_LUTINPUT_SCALE (R/W)
      10401764h       - PICA(01D9h)   - GPUREG_LIGHTING_LIGHT_PERMUTATION (R/W)

3DS GPU Internal Registers - Geometry Pipeline registers

      10401800h       - PICA(0200h)   - GPUREG_ATTR_BUF_BASE (R/W)
      10401804h       - PICA(0201h)   - GPUREG_ATTR_BUF_FORMAT_LOW (R/W)
      10401808h       - PICA(0202h)   - GPUREG_ATTR_BUF_FORMAT_HIGH (R/W)
      1040180Ch+i*0Ch - PICA(0203h+3*(0..11)) - GPUREG_ATTR_BUFi_OFFSET (R/W)
      10401810h+i*0Ch - PICA(0204h+3*(0..11)) - GPUREG_ATTR_BUFi_CONFIG_LOW (R/W)
      10401814h+i*0Ch - PICA(0205h+3*(0..11)) - GPUREG_ATTR_BUFi_CONFIG_HIGH (R/W)
      1040189Ch       - PICA(0227h)   - GPUREG_ATTR_BUF_INDEX_LIST (R/W)
      104018A0h       - PICA(0228h)   - GPUREG_ATTR_BUF_NUMVERTICES (R/W)
      104018A4h       - PICA(0229h)   - GPUREG_GEOSTAGE_CONFIG (R/W)
      104018A8h       - PICA(022Ah)   - GPUREG_ATTR_BUF_FIRST_INDEX (R/W)
      104018B4h       - PICA(022Dh)   - GPUREG_POST_VERTEX_CACHE_NUM (R/W)
      104018B8h       - PICA(022Eh)   - GPUREG_ATTR_BUF_DRAWARRAYS (W)
      104018BCh       - PICA(022Fh)   - GPUREG_ATTR_BUF_DRAWELEMENTS (W)
      104018C4h       - PICA(0231h)   - GPUREG_VTX_FUNC (W)
      104018C8h       - PICA(0232h)   - GPUREG_FIXEDATTRIB_INDEX (W)
      104018CCh+i*4   - PICA(0233h+i) - GPUREG_FIXEDATTRIB_DATA(0..2) (W)
      104018E0h       - PICA(0238h)   - GPUREG_CMDBUF_SIZE0 (R/W)
      104018E4h       - PICA(0239h)   - GPUREG_CMDBUF_SIZE1 (R/W)
      104018E8h       - PICA(023Ah)   - GPUREG_CMDBUF_ADDR0 (aka entrypoint) (R/W)
      104018ECh       - PICA(023Bh)   - GPUREG_CMDBUF_ADDR1 (aka entrypoint) (R/W)
      104018F0h       - PICA(023Ch)   - GPUREG_CMDBUF_JUMP0 (jump to ADDR0) (W)
      104018F4h       - PICA(023Dh)   - GPUREG_CMDBUF_JUMP1 (jump to ADDR1) (W)
      10401908h       - PICA(0242h)   - GPUREG_VSH_NUM_ATTR (R/W)
      1040190Ch       - PICA(0243h)   - GPUREG_undoc_1040190Ch (R/W=00000037h)
      10401910h       - PICA(0244h)   - GPUREG_VSH_COM_MODE (R/W)
      10401914h       - PICA(0245h)   - GPUREG_START_DRAW_FUNC0 (R/W)
      10401928h       - PICA(024Ah)   - GPUREG_VSH_OUTMAP_TOTAL1 (R/W)
      10401944h       - PICA(0251h)   - GPUREG_VSH_OUTMAP_TOTAL2 (R/W)
      10401948h       - PICA(0252h)   - GPUREG_GSH_MISC0 (R/W)
      1040194Ch       - PICA(0253h)   - GPUREG_GEOSTAGE_CONFIG2 (R/W)
      10401950h       - PICA(0254h)   - GPUREG_GSH_MISC1 (R/W)
      10401954h       - PICA(0255h)   - GPUREG_undoc_10401954h (R/W=00000001h)
      10401978h       - PICA(025Eh)   - GPUREG_PRIMITIVE_CONFIG (R/W)
      1040197Ch       - PICA(025Fh)   - GPUREG_RESTART_PRIMITIVE (R/W)

3DS GPU Internal Registers - Shader 0 (Geometry Shader)

      10401A00h       - PICA(0280h)   - GPUREG_GSH_BOOLUNIFORM (R/W)
      10401A04h+i*4   - PICA(0281h+i) - GPUREG_GSH_INTUNIFORM_I0..I3 (R/W)
      10401A24h       - PICA(0289h)   - GPUREG_GSH_INPUTBUFFER_CONFIG (R/W)
      10401A28h       - PICA(028Ah)   - GPUREG_GSH_ENTRYPOINT (R/W)
      10401A2Ch       - PICA(028Bh)   - GPUREG_GSH_ATTR_PERMUTATION_LOW (R/W)
      10401A30h       - PICA(028Ch)   - GPUREG_GSH_ATTR_PERMUTATION_HIGH (R/W)
      10401A34h       - PICA(028Dh)   - GPUREG_GSH_OUTMAP_MASK (R/W)
      10401A3Ch       - PICA(028Fh)   - GPUREG_GSH_CODETRANSFER_END (W)
      10401A40h       - PICA(0290h)   - GPUREG_GSH_FLOATUNIFORM_INDEX (W)
      10401A44h+i*4   - PICA(0291h+i) - GPUREG_GSH_FLOATUNIFORM_DATA(0..7) (W)
      10401A6Ch       - PICA(029Bh)   - GPUREG_GSH_CODETRANSFER_INDEX (W)
      10401A70h+i*4   - PICA(029Ch+i) - GPUREG_GSH_CODETRANSFER_DATA(0..7) (W)
      10401A94h       - PICA(02A5h)   - GPUREG_GSH_OPDESCS_INDEX (W)
      10401A98h+i*4   - PICA(02A6h+i) - GPUREG_GSH_OPDESCS_DATA(0..7) (W)

3DS GPU Internal Registers - Shader 1 (Vertex Shader)

      10401AC0h       - PICA(02B0h)   - GPUREG_VSH_BOOLUNIFORM (R/W)
      10401AC4h+i*4   - PICA(02B1h+i) - GPUREG_VSH_INTUNIFORM_I0..I3 (R/W)
      10401AE4h       - PICA(02B9h)   - GPUREG_VSH_INPUTBUFFER_CONFIG (R/W)
      10401AE8h       - PICA(02BAh)   - GPUREG_VSH_ENTRYPOINT (R/W)
      10401AECh       - PICA(02BBh)   - GPUREG_VSH_ATTR_PERMUTATION_LOW (R/W)
      10401AF0h       - PICA(02BCh)   - GPUREG_VSH_ATTR_PERMUTATION_HIGH (R/W)
      10401AF4h       - PICA(02BDh)   - GPUREG_VSH_OUTMAP_MASK (R/W)
      10401AFCh       - PICA(02BFh)   - GPUREG_VSH_CODETRANSFER_END (W)
      10401B00h       - PICA(02C0h)   - GPUREG_VSH_FLOATUNIFORM_INDEX (W)
      10401B04h+i*4   - PICA(02C1h+i) - GPUREG_VSH_FLOATUNIFORM_DATA(0..7) (W)
      10401B2Ch       - PICA(02CBh)   - GPUREG_VSH_CODETRANSFER_INDEX (W)
      10401B30h+i*4   - PICA(02CCh+i) - GPUREG_VSH_CODETRANSFER_DATA(0..7) (W)
      10401B54h       - PICA(02D5h)   - GPUREG_VSH_OPDESCS_INDEX (W)
      10401B58h+i*4   - PICA(02D6h+i) - GPUREG_VSH_OPDESCS_DATA(0..7) (W)

3DS GPU Internal Registers - Shader 2 (Unknown purpose)

      10401B80h       - PICA(02E0h)   - GPUREG_VSH2_BOOLUNIFORM (R/W)
      10401B84h+i*4   - PICA(02E1h+i) - GPUREG_VSH2_INTUNIFORM_I0..I3 (R/W)
      10401BA4h       - PICA(02E9h)   - GPUREG_VSH2_INPUTBUFFER_CONFIG (R/W)
      10401BA8h       - PICA(02EAh)   - GPUREG_VSH2_ENTRYPOINT (R/W)
      10401BACh       - PICA(02EBh)   - GPUREG_VSH2_ATTR_PERMUTATION_LOW (R/W)
      10401BB0h       - PICA(02ECh)   - GPUREG_VSH2_ATTR_PERMUTATION_HIGH (R/W)
      10401BB4h       - PICA(02EDh)   - GPUREG_VSH2_OUTMAP_MASK (R/W)
      10401BBCh       - PICA(02EFh)   - GPUREG_VSH2_CODETRANSFER_END (W)
      10401BC0h       - PICA(02F0h)   - GPUREG_VSH2_FLOATUNIFORM_INDEX (W)
      10401BC4h+i*4   - PICA(02F1h+i) - GPUREG_VSH2_FLOATUNIFORM_DATA(0..7) (W)
      10401BECh       - PICA(02FBh)   - GPUREG_VSH2_CODETRANSFER_INDEX (W)
      10401BF0h+i*4   - PICA(02FCh+i) - GPUREG_VSH2_CODETRANSFER_DATA(0..7) (W)
      10401C14h       - PICA(0305h)   - GPUREG_VSH2_OPDESCS_INDEX (W)
      10401C18h+i*4   - PICA(0306h+i) - GPUREG_VSH2_OPDESCS_DATA(0..7) (W)

3DS GPU Internal Registers - Shader 3 (Unknown purpose)

      10401C40h       - PICA(0310h)   - GPUREG_VSH3_BOOLUNIFORM (R/W)
      10401C44h+i*4   - PICA(0311h+i) - GPUREG_VSH3_INTUNIFORM_I0..I3 (R/W)
      10401C64h       - PICA(0319h)   - GPUREG_VSH3_INPUTBUFFER_CONFIG (R/W)
      10401C68h       - PICA(031Ah)   - GPUREG_VSH3_ENTRYPOINT (R/W)
      10401C6Ch       - PICA(031Bh)   - GPUREG_VSH3_ATTR_PERMUTATION_LOW (R/W)
      10401C70h       - PICA(031Ch)   - GPUREG_VSH3_ATTR_PERMUTATION_HIGH (R/W)
      10401C74h       - PICA(031Dh)   - GPUREG_VSH3_OUTMAP_MASK (R/W)
      10401C7Ch       - PICA(031Fh)   - GPUREG_VSH3_CODETRANSFER_END (W)
      10401C80h       - PICA(0320h)   - GPUREG_VSH3_FLOATUNIFORM_INDEX (W)
      10401C84h+i*4   - PICA(0321h+i) - GPUREG_VSH3_FLOATUNIFORM_DATA(0..7) (W)
      10401CACh       - PICA(032Bh)   - GPUREG_VSH3_CODETRANSFER_INDEX (W)
      10401CB0h+i*4   - PICA(032Ch+i) - GPUREG_VSH3_CODETRANSFER_DATA(0..7) (W)
      10401CD4h       - PICA(0335h)   - GPUREG_VSH3_OPDESCS_INDEX (W)
      10401CD8h+i*4   - PICA(0336h+i) - GPUREG_VSH3_OPDESCS_DATA(0..7) (W)

3DS GPU External Registers - Memory Control/Status Registers

The 3DS bootrom error screen initializes only 10400004h and 10400030h (VRAM control/power). The 3DS OS does reportedly also initialize 10400050h and 10400054h (timings?).
10400000h - GPU_FIXED_00010002h (always 00010002h, maybe ChipID/Version) (R)

      0-31  Always 00010002h (maybe ChipID/Version)

Note: Register 104010D4h seems to contain the same readonly value.
10400004h - GPU_VRAM_CNT (reset=0, bootrom=300h) (R/W)

      0-31  Unknown (0..FFFFFFFFh)

Seems to have no effect on LCD output. However, value FFFFFFFFh does mess up the polygon renderer (or MEMCOPY unit), causing each 4 scanlines to be drawn twice.
10400008h - GPU_UNKNOWN_2BIT (reset=0) (R/W)

      0-1   Unknown (0..03h)
      2-31  Unused (0)

10400030h - GPU_VRAM_POWER (R/W)

      0-7   Unknown (0..FFh)
      8     Power off VRAM_A data.bit0-63   (0=On, 1=Power Off)
      9     Power off VRAM_A data.bit64-127 (0=On, 1=Power Off)
      10    Power off VRAM_B data.bit0-63   (0=On, 1=Power Off) ;\later uses VRAM_A
      11    Power off VRAM_B data.bit64-127 (0=On, 1=Power Off) ;/when VRAM_B=off?
      12-31 Unknown (0..FFFFFh)

Seems to disable VRAM power, VRAM_A/B are 3Mbyte each, and each of them seems to have separate sections for data bit0-63 and 64-127 (ie. the first and second 8 bytes within 16 byte snippets).
After writing to 10400030h, one should issue a dummy read from 10400030h.
Even when disabled only for a short moment, the VRAM does immediately forget it's data and gets filled with random values; this can be seen after re-enabling the memory (the CPU hangs when reading VRAM while it is disabled).
10400034h - GPU_STAT_IRQ_FLAGS (R)
Contains IRQ flags (normally IRQ handling/polling should work fine without needing this register; except, polling GPU_MEMCOPY_CNT can apparently hang the CPU, whilst polling GPU_STAT_IRQ_FLAGS.bit30 does work better).

      0     Unknown, usually set ;\get cleared when setting GPU_MAKE_SOMETHING.bit0
      1     Unknown, usually set ;/(unknown if/when the flags can get set again)
      2-25  Unused (0)
      26    IRQ 28h PSC0 aka GPU_MEMFILL 0 ready ;mirror of GPU_MEMFILL_CNT0.bit1
      27    IRQ 29h PSC1 aka GPU_MEMFILL 1 ready ;mirror of GPU_MEMFILL_CNT1.bit1
      28    IRQ 2Ah PDC0 aka GPU H/V-IRQ for top screen
      29    IRQ 2Bh PDC1 aka GPU H/V-IRQ for bottom screen
      30    IRQ 2Ch PPF  aka GPU_MEMCOPY ready   ;mirror of GPU_MEMCOPY_CNT.bit8
      31    IRQ 2Dh P3D  aka GPUREG_IRQ_CMP/REQ match (commonly at end of cmdlist)

Bit26,27,30 can be cleared in the corresponding mirrored registers.
Bit28,29 are automatically set/cleared during LCD output (usually once per frame).
Bit31 can be cleared by setting IRQ_REQ and IRQ_CMP to different values.
10400038h - GPU_STAT_SOMETHING (R)

      0-31  Can be 00000000h, 10400800h, 10402000h, or 10410000h

Unknown, initially 10402000h on reset, 10400800h after LCD init or so, and becomes 00000000h after setting GPU_MAKE_SOMETHING.bit0, and (thereafter?) changes to 10410000h. No idea if 104xxxxxh is related to the address of the GPU I/O area.
1040003Ch - GPU_MAKE_SOMETHING (R/W)

      0     Unknown (0=Normal, 1=GPU_STAT_SOMETHING changes after a while)
      1-31  Unknown (0..7FFFFFFFh)

Unknown, setting bit0 (even only for a short moment) will later on cause GPU_STAT_SOMETHING to become 10410000h. Also affects GPU_STAT_IRQ_FLAGS.bit0-1.
10400040h - GPU_STAT_BACKLIGHT_OR_SO (R)

      0-1   Unknown (usually 0, but can be 3 when [104000C0h]=0 or [104000CCh]=0)
      2-31  Unused (0)

10400044h - GPU_UNKNOWN_CAN_BE_7F80h (R)

      0-31  Texture related...? (usually 0, but sometimes 7F80h, and once 1200h)

Unknown. Usually zero, but can contain other values after rendering with GPUREG_TEXUNIT_CONFIG=nonzero (even then, it does often stay zero, but sometimes changes to 7F80h, and once changed to 1200h). Whether the register does change seems to depend on power-up state of other uninitialized registers/memory and/or whatever timings (if nonzero values did occur then they do usually reappear upon next rendering even after reset, but that behaviour can change on next power-up).
Note: Value 1200h occurred after changing GPUREG_COLORBUFFER_LOC and GPUREG_DEPTHBUFFER_LOC to dummy address zero (but that couldn't be reproduced).
10400048h - GPU_UNKNOWN_32BIT (reset=0) (R/W)

      0-31  Unknown (0..FFFFFFFFh)

10400050h - GPU_TIMING_CNT1 (R/W=FFFFFFFFh) (res=1111EF00h) ;init=22221200h

      0-31  Unknown (0..FFFFFFFFh) (affects GPU_MEMCOPY timings and maybe others)

Somehow affects timings. Different values can make timings about 10% faster or slower (or, some values seem to make no difference at all). For example,

      10101010h or 20202020h --> slower MEMCOPY
      1111EF00h or 22221200h --> normal MEMCOPY
      FFFFFFFFh              --> faster MEMCOPY

10400054h - GPU_TIMING_CNT2 (R/W=FFFFFFFFh) (res=00000112h) ;init=00000FF2h

      0-31  Unknown (0..FFFFFFFFh) (probably affects whatever timings)

10400058h - GPU_STAT_BUSY_FLAGS (R)

      10    Unknown, seems to be set on power-up, but later cleared?
      17    Often set after writing GPU_VRAM_POWER
      18    Sometimes set after writing GPU_VRAM_POWER
      19    GPU_MEMFILL_0/1 Busy (0=No, 1=Busy)
      20    GPU_MEMCOPY Busy     (0=No, 1=Busy; gets set some cycles after start)

1040005Ch - GPU_MAKE_WHATEVER_MESS (R/W)

      0     Whatever, gets copied to bit8                   (W)
      8     Whatever, contains value written to bit0        (R)
      16-21 Whatever, 00h..3Fh                              (R/W)
      24-29 Whatever, 00h..3Fh                              (R/W)

Affects the 30h-word pattern returned when reading below register.
10400060h - GPU_STAT_WHATEVER_MESS (R)

      0-6   Unused? (0)
      7-22  Whatever Mess
      23    Unused? (0)
      24-29 Whatever Mess
      30-31 Unused? (0)

Repeatly reading returns a mess, repeated every 30h words, for example:

      08002400h, 01404180h, 04002000h, 00020000h, 20000200h, 02080000h, 00080000h,
      0041A000h, 11006100h, 00041000h, 00242000h, 00100880h, 1200A000h, 08000000h,
      10042080h, 04082400h, 00002400h, 00000000h, 1040C500h, 03000000h, ...

The same values as above are also returned when inserting delays in the read loop. So it's either random generated... or a FIFO that reads junk from an uninitialized array?
Changing 1040005Ch (eg. writing FFFFFFFFh) causes above to return different garbage values (also reapeating each 30h words, but containing a more regular pattern with fewer bits set).
10400068h GPU_UNKNOWN_INITIALLY_00A80000h (res=00A80000h) (R/W)

      0-31  Unknown (0..FFFFFFFFh) (initially 00A80000h on reset)

10400070h - Read-only memory traffic counters (R)

      10400070h  GPU_STAT_TOTAL_NON_VRAM_READS      ;\Non-VRAM (eg. AXI,QTM,FCRAM)
      10400074h  GPU_STAT_TOTAL_NON_VRAM_WRITES     ;/
      10400078h  GPU_STAT_TOTAL_VRAM_A_READS        ;\1st 3Mbyte VRAM block
      1040007Ch  GPU_STAT_TOTAL_VRAM_A_WRITES       ;/
      10400080h  GPU_STAT_TOTAL_VRAM_B_READS        ;\2nd 3Mbyte VRAM block
      10400084h  GPU_STAT_TOTAL_VRAM_B_WRITES       ;/
      10400088h  GPU_STAT_POLYGON_ARRAY_READS       ;-ATTR_BUF, INDEX_LIST
      1040008Ch  GPU_STAT_POLYGON_TEXTURE_READS     ;-cache misses only
      10400090h  GPU_STAT_POLYGON_DEPTHBUFFER_READS
      10400094h  GPU_STAT_POLYGON_DEPTHBUFFER_WRITES
      10400098h  GPU_STAT_POLYGON_COLORBUFFER_READS
      1040009Ch  GPU_STAT_POLYGON_COLORBUFFER_WRITES
      104000A0h  GPU_STAT_LCD_UPPER_SCREEN_READS    ;\for both left+right buffer
      104000A4h  GPU_STAT_LCD_LOWER_SCREEN_READS    ;/
      104000A8h  GPU_STAT_MEMCOPY_SRC_READS         ;\GPU_MEMCOPY
      104000ACh  GPU_STAT_MEMCOPY_DST_WRITES        ;/
      104000B0h  GPU_STAT_MEMFILL_0_DST_WRITES      ;\GPU_MEMFILL 0/1
      104000B4h  GPU_STAT_MEMFILL_1_DST_WRITES      ;/
      104000B8h  GPU_STAT_CPU_READS_FROM_VRAM_A_B   ;\counted by GPU because the
      104000BCh  GPU_STAT_CPU_WRITES_TO_VRAM_A_B    ;/GPU must forward vram to cpu

104000C4h - GPU_BASE_ADDR_VRAM_A (reset=18000000h) (R/W)
104000C8h - GPU_BASE_ADDR_VRAM_B (reset=18300000h) (R/W)

      0-31  Base address for VRAM_A/B blocks (0..FFFFFFFFh) (any alignment needed?)

The 3DS contains two 3MByte VRAM blocks (ie. 6Mbyte in total). These registers allow to swap the base address of those two blocks, or to map them to other locations within the following 12Mbyte region:

      18000000h..182FFFFFh  Usually VRAM_A (3Mbyte)
      18300000h..185FFFFFh  Usually VRAM_B (3Mbyte)
      18600000h..18BFFFFFh  Usually empty/zerofilled (6Mbyte)

Trying to map VRAM outside of that 12Mbyte region might work, but the ARM CPU will trigger data aborts when trying to access that memory.
104000C0h - GPU_BACKLIGHT_OR_SO_1 (reset=20000000h) (R/W)
104000CCh - GPU_BACKLIGHT_OR_SO_2 (reset=20000000h) (R/W)

      0-31  Unknown (0..FFFFFFFFh)

Reportedly 104000C0h does "Writes 0 to allow backlights to turn off, 20000000h to force them always on."
Unknown what that means. Default is 20000000h (and backlights CAN be switched off in that state). Maybe "allow" means that they can switch off automatically... upon GPU inactivity... or upon blank screen... or upon screen saver timeouts... or whatever? Or maybe 20000000h is FCRAM base, completely unrelated to backlights?
Note: Setting [104000C0h] or [104000CCh] to zero can cause [10400040h] to get nonzero.
104000D0h - GPU_UNKNOWN_4BIT (reset=0) (R/W)

      0-3   Unknown (0..0Fh)
      4-31  Unused (0)

3DS GPU External Registers - Top/Bottom Screen and Framebuffer Setup

104004xxh = Framebuffer Setup "PDC0" (top screen)
104005xxh = Framebuffer Setup "PDC1" (bottom screen)
PDC = "PICA Display Control" or so?
Top/Bottom Screen Setup Register Summary

      10400400h/10400500h 4   V-Total-1                 ;1C2h       ;\
      10400404h/10400504h 4   V-Lower-border-end        ;0D1h       ;
      10400408h/10400508h 4   V-Upper-border-middle     ;1C1h       ;
      1040040Ch/1040050Ch 4   V-Upper-border-end        ;1C1h       ; V
      10400410h/10400510h 4   V-Sync-start              ;000h/0CDh  ;
      10400414h/10400514h 4   V-Sync-end                ;0CFh       ;
      10400418h/10400518h 4   V-Lower-border-start      ;0D1h       ;
      1040041Ch/1040051Ch 2   V-IRQ-start               ;1C1h       ;
      1040041Eh/1040051Eh 2   V-IRQ-end                 ;1C5h       ;/
      10400420h/10400520h 2   V-Pre-padding fetch start?;000h       ;\V
      10400422h/10400522h 2   V-??   ;must be <=1C2h    ;001h       ;/
      10400424h/10400524h 4   H-Total-1                 ;19Dh       ;\
      10400428h/10400528h 4   H-Left-border-end         ;002h/052h  ;
      1040042Ch/1040052Ch 4   H-Right-border-middle     ;192h       ;
      10400430h/10400530h 4   H-Right-border-end        ;192h       ; H
      10400434h/10400534h 4   H-Sync-Start              ;192h/04Fh  ;
      10400438h/10400538h 4   H-Sync-End                ;001h/050h  ;
      1040043Ch/1040053Ch 4   H-Left-border-start       ;002h/052h  ;
      10400440h/10400540h 2   H-IRQ-start (or end)      ;192h       ;
      10400442h/10400542h 2   H-IRQ-end (or start)      ;193h       ;/
      10400444h/10400544h 4   V-Increment-H             ;000h       ;-V
      10400448h/10400548h 4   Screen Vsync/Hsync type
      1040044Ch/1040054Ch 4   Screen Border color
      10400450h/10400550h 4   V-Current position (R)
      10400454h/10400554h 4   H-Current position (R)
      10400458h/10400558h 04h Unused (0)
      1040045Ch/1040055Ch 2   V-Picture size            ;0F0h       ;-V
      1040045Eh/1040055Eh 2   H-Picture size (no effect);190h/140h  ;-H
      10400460h/10400560h 2   V-Lower-border-middle     ;0D1h       ;\V
      10400462h/10400562h 2   V-Upper-border-start      ;1C1h       ;/
      10400464h/10400564h 2   H-Left-border-middle      ;002h/052h  ;\H
      10400466h/10400566h 2   H-Right-border-start      ;192h       ;/
      10400468h/10400568h 4   Framebuffer 0 address for Left eye (or both eyes)
      1040046Ch/1040056Ch 4   Framebuffer 1 address for Left eye (or both eyes)
      10400470h/10400570h 4   Framebuffer format
      10400474h/10400574h 4   Interrupt type
      10400478h/10400578h 4   Framebuffer Select and Request/Ack
      1040047Ch/1040057Ch 4   Screen Status flags (R)
      10400480h/10400580h 4   Color Lookup Table index (R/W)
      10400484h/10400584h 4   Color Lookup Table data (R/W)
      10400488h/10400588h 08h Unused (0)
      10400490h/10400590h 4   Framebuffer Horizontal Address Step
      10400494h/10400594h 4   Framebuffer 0 address for Right eye (or unused
      10400498h/10400598h 4   Framebuffer 1 address for Right eye (or unused
      1040049Ch/1040059Ch 2   V-Latching-Point          ;000h       ;-V
      1040049Eh/1040059Eh 2   H-Latching-Point          ;192h       ;-H
      104004A0h/104005A0h 60h Unused (0)

Most of the registers do have internal copies (the H/V registers, and Border color, and maybe some others), changing these registers doesn't have any effect on the visible picture & timings - until reaching the H/V-Latching Point (which does forward the registers to their internal copies).

     __________________________ Control/Status Registers __________________________

10400474h/10400574h - Interrupt Type (R/W)

      0      Display Enable (should be 1) (0=Off/screen fades out, 1=On/normal)
      1-7    Unused (0)
      8-10   Interrupt Mode (5=OncePerFrame, 7=None, 0..4,6=Special) (see below)
      7-11   Unused (0)
      16     Unknown...?    (0=???, 1=Normal)
      17-31  Unused (0)

The default is Interrupt Mode 5 (which acts as normal framerate interrupt).
Interrupt Mode 0,1,2,3 do require manually acknowledging/requesting the next IRQ via Request register bit18 (and bit17 in some cases).

      Interrupt Mode 0:
      - Triggers here or there depending on H/V settings
      Interrupt Mode 1:
      - Triggers at V=[10400544h], H=[10400540h]               ;irq point
      - Triggers at V=[10400504h], H=[10400528h]..[10400566h]  ;picture area
      Interrupt Mode 2:
      - Triggers here or there depending on H/V settings
      Interrupt Mode 3:
      - Triggers at V=[10400504h], H=[10400528h]..[10400566h]  ;picture area
      Interrupt Mode 4 (in selected H's)
      - Triggers at V=[1040051Ch], and H=[10400542h]..[10400540h]
      Interrupt Mode 5 (framerate interrupt, usually at H=Hblank)
      - Triggers at V=[10400544h] and H=[10400540h]
      Interrupt Mode 6 (once on every H)
      - Triggers at V=[1040051Ch], and H=any
      Interrupt Mode 7 (interrupts disabled)
      - Doesn't trigger any IRQs.

For all IRQ H/V timings, mind that the display is drawn from left to right (unlike normal top-to-bottom displays).
Note: Most of the H positions do actually trigger at H+1 (and perhaps similar for V positions, though those are more difficult to measure).
10400478h/10400578h - Framebuffer Select and Request/Ack (R/W)

      0      Display Framebuffer (0=Buffer 0, 1=Buffer 1)
      1-3    Unused (0)
      4      Request STAT.bit4 to get triggered (0=No, 1=Request/Busy)
      5-7    Unused (0)
      8      Unknown...?   (0=Normal, 1=???)
      9-15   Unused (0)
      16     Unknown...?   (0=Normal, 1=???)
      17     Unknown...?   (0=Normal, 1=???, set in bootrom IRQ handler, but why?)
      18     Acknowledge STAT.bit15? resurrect after ONESHOT irq (unless,
               bit18/ack works ONLY if OUTSIDE of display area?)
      19-31  Unused (0)

Apart from bit0, all bits in the register are kind of "Request/Busy" flags (and get cleared once when the request is handled).

      bit4:          cleared at H=[10400540h]..[10400542h]
      bit8,16,17,18: cleared after a handful of clock cycles

Request.bit4 does soemhow relate to the framebuffer selection in bit0 (see STAT.bit4 for details)... Guess: maybe bit4 prevents bit0 from being internally applied until hblank?
1040047Ch/1040057Ch - Screen Status flags (R)

      0      H-IRQ-area, when H=[10400540h]..[10400542h]
      1      V-IRQ-area, when H=[1040051Ch]..[1040051Eh]
      2-3    Unused (0)
      4      Can get set if [10400578h].bit4=1, and depending on [10400578h].bit0:
               if [10400578h].bit4=0: at H=[10400540h]..[10400528h]  ;ONCE
               if [10400578h].bit4=1: at H=[10400528h]..FOREVER      ;FOREVER
               that, happening at V=[10400544h] (in both of the above two cases)
               note: ONCE means that the bit goes ON-and-OFF once (and stays off)
               note: FOREVER means that the bit goes ON (and stays on)
      5-7    Unused (0)
      8      H-Sync,    H=[10400534h]..[10400538h]
      9      H-Blank,   H=[10400530h]..[1040053Ch] (between borders)
      10     H-Picture, H=[10400528h]..[10400566h] (between borders)
      11     Unused (0)
      12     V-Sync,    H=[10400510h]..[10400514h]
      13     V-Blank,   H=[1040050Ch]..[10400518h] (between borders)
      14     V-Picture, H=[10400504h]..[10400562h] (between borders)
      15     Normally 0, but can be set, if interrupts enabled IRQ request?
               bit15: set at H/V-picture start, sticky bit?
               but, WHY is bit15 is never set with bootrom default settings?
               related to 1040059Ch,1040059Eh !!!
      16-31  Unused (0)

10400448h/10400548h - Screen Vsync/Hsync type (R/W)

      0      Seems to disable HSync (or Vsync?), or sync mode/polarity or so?
      1-7    Unused (0)
      8      Seems to disable VSync (or Hsync?), or sync mode/polarity or so?
      9-31   Unused (0)

Should be 00h/11h for top/bottom screen. Maybe selects using /SYNC signals or types like "DE only" with sync on Display Enable? The pinout for bottom screen is said to include /HSYNC and /VSYNC pins. The pinout for top screen is unknown.

     ___________________________ Framebuffer Registers ___________________________

10400468h/10400568h - Framebuffer 0 address for Left eye (or both eyes)
1040046Ch/1040056Ch - Framebuffer 1 address for Left eye (or both eyes)
10400494h/10400594h - Framebuffer 0 address for Right eye (or unused)
10400498h/10400598h - Framebuffer 1 address for Right eye (or unused)

      0-3    Unused (0)
      4-31   Address, in 16-byte units

10400490h/10400590h - Framebuffer Horizontal Address Step (R/W)

      0-3    Unused (0)
      4-31   Address step, in 16-byte units (usually 3Ch, aka 240pix*4byte/16)

10400470h/10400570h - Framebuffer format (R/W)

      0-2    Framebuffer RGBA Format (0=8888, 1=8880, 2=5650, 3=5551, 4..?=4444)
               Note: The alpha in RGBA types is just skipped/ignored.
      3      Unused (0)
      4-5    Horizontal Zoom (0=Normal/HiRes, 1=Double/LowRes, 2/3=LeftRightBuffer)
      6      Vertical Zoom   (0=Normal/HiRes, 1=Double/LowRes)
      7      Unused (0)
      8-9    Unknown (0..3) (should be 0)
               00h = Normal (should be normally used)
               01h = Unknown "get rid of rainbow strip on top of screen" uh? mess!
               02h = Unknown                (actually distorted display?)
               03h = Unknown "black screen" (actually normal display?)
      10-15  Unused (0)
      16-31  Unknown (0..FFFFh) (should be 8)
                (FFFFh=slow horizontal drawing?)
                maybe... dotclk divider (and perhaps multiplier in other bits)
                hmmm, but, very large values cause vram-misaddressing?

Obscure Color Format Notes:
Color components are laid out in reverse byte order, with the most significant bits used first (ie. non-24bit pixels are stored as a little-endian values). For instance, a raw data stream of two GL_RGB565_OES pixels looks like GGGBBBBB RRRRRGGG GGGBBBBB RRRRRGGG. uh, that are TWO pixels, but which one is shown first/bottom? uh, and that's for non-24bit, so, how does 24bit look like?

     ______________________________ Color Registers  ______________________________

10400480h/10400580h - Color Lookup Table index (R/W)

      0-7    Index        ;reportedly write-only (uh, but actually, it is R/W)
      8-31   Unused (0)

10400484h/10400584h - Color Lookup Table data (R/W)

      0-7    Red[index]  ;\
      8-15   Green[index]; is that always RGB, or could it be swapped to BGR or so?
      16-23  Blue[index] ;/
      24-31  Unused (0)

Contains the value of the color lookup table indexed by the above register. Accessing this register will increase the index register by one.
For RGBA 8888/8880, the table should be usually filled with linear increasing values: 000000h, 010101h, 020202h, 030303h, .., FFFFFFh. Or alternately with non-linear values if the displays require 'gamma' adjustments.
Unknown which indices are used in RGBA 5650, 5551, and 4444 modes.
1040044Ch/1040054Ch - Screen Border color (R/W)

      0-7    Red    (00h..FFh)
      8-15   Green  (00h..FFh)
      16-23  Blue   (00h..FFh)
      24-31  Unused (0)

The screen border isn't used for fullscreen pictures, but it could be used if the picture is smaller than the actual screen. To disable the border, set border start/end registers to the same value.
There are also "border middle" registers (with unknown purpose and without visible effect, except, the middle values for vertical border MUST be within border start/end range, otherwise the screen dies with fading out).

     _______________________________ H/V-Registers _______________________________

Vertical Position Registers

      10400444h/10400544h 4   V-Increment-H             ;000h
      1040049Ch/1040059Ch 2   V-Latching-Point          ;000h
      10400420h/10400520h 2   V-Pre-padding fetch start?;000h
      10400422h/10400522h 2   V-??   ;must be <=1C2h    ;001h
      10400410h/10400510h 4   V-Sync-start              ;000h/0CDh
      10400414h/10400514h 4   V-Sync-end                ;0CFh
      10400418h/10400518h 4   V-Lower-border-start      ;0D1h
      10400460h/10400560h 2   V-Lower-border-middle     ;0D1h
      10400404h/10400504h 4   V-Lower-border-end        ;0D1h
      1040045Ch/1040055Ch 2   V-Picture size            ;0F0h
      10400462h/10400562h 2   V-Upper-border-start      ;1C1h
      10400408h/10400508h 4   V-Upper-border-middle     ;1C1h
      1040040Ch/1040050Ch 4   V-Upper-border-end        ;1C1h
      1040041Ch/1040051Ch 2   V-IRQ-start               ;1C1h
      1040041Eh/1040051Eh 2   V-IRQ-end                 ;1C5h
      10400400h/10400500h 4   V-Total-1                 ;1C2h
      10400450h/10400550h 4   V-Current position (R)    ;000h..1C2h

These are usually using same values for top/bottom screen (with 240pix height each), except that Nintendo has used different Sync length for some reason.
Horizontal Position Registers

      10400434h/10400534h 4   H-Sync-Start              ;192h/04Fh
      10400438h/10400538h 4   H-Sync-End                ;001h/050h
      1040043Ch/1040053Ch 4   H-Left-border-start       ;002h/052h
      10400464h/10400564h 2   H-Left-border-middle      ;002h/052h
      10400428h/10400528h 4   H-Left-border-end         ;002h/052h
      1040045Eh/1040055Eh 2   H-Picture size (no effect);190h/140h
      10400466h/10400566h 2   H-Right-border-start      ;192h
      1040042Ch/1040052Ch 4   H-Right-border-middle     ;192h
      10400430h/10400530h 4   H-Right-border-end        ;192h
      1040049Eh/1040059Eh 2   H-Latching-Point          ;192h
      10400440h/10400540h 2   H-IRQ-start (or end)      ;192h
      10400442h/10400542h 2   H-IRQ-end (or start)      ;193h
      10400424h/10400524h 4   H-Total-1                 ;19Dh
      10400454h/10400554h 4   H-Current position (R)    ;000h..19Dh

These are using the same Htotal for top/bottom screen, but different picture/blanking widths (for top/bottom screens with 400pix/320pix width). The top screen does also support a 800pix hires mode (which should use double Htotal, and adjust other registers accordingly).
Note: The values in the H/V registers are 12bit wide, 0..FFFh (the upper 4bit/20bit of the 16bit/32bit registers are unused, always zero).
Wrong H/V values may cause various effects - which may differ depending on the display type. New3DS bottom screen tends to output a stable image (with fading upper/right areas if it is too small), or no picture at all (with whole screen fading). However, other screens are said to lose sync or misalign lines and such stuff.
Setting the V-pre-padding bigger than V-lower-border end causes the bottom-most picture lines to display the most recent pixel color instead of fetching new pixels from VRAM. A Similar effect occurs in upper picture area when setting V-picture-size too small.

     _________________________________ Misc Notes _________________________________

Framebuffers
These LCD framebuffers normally contain the last rendered frames from the GPU. The framebuffers are drawn from left-to-right, instead of top-to-bottom. Thus the beginning of the framebuffer is drawn starting at the left side of the screen.
Both of the 3D screen left/right framebuffers are displayed regardless of the 3D slider's state, however when the 3D slider is set to "off" the 3D effect is disabled. Normally when the 3D slider's state is set to "off" the left/right framebuffer addresses are set to the same physical address. When the 3D effect is disabled and the left/right framebuffers are set to separate addresses, the LCD seems to alternate between displaying the left/right framebuffer each frame.
Uh, it can alternate left/right buffers each frame? I have NEVER seen that effect when testing register settings (and it would have caused massive flicker because I didn't had initialized the right buffer). What it can do is alternate left/right buffer after each pixel horizontally (including on bottom screen).
Init Values from nngxInitialize for Top Screen
Unknown if below values are "better" than bootrom, or if they are typos.

      10400400h = 1C2h
      10400404h = D1h
      10400408h = 1C1h
      1040040Ch = 1C1h
      10400410h = 0
      10400414h = CFh
      10400418h = D1h
      1040041Ch = 1C501C1h
      10400420h = 10000h
      10400424h = 19Dh
      10400428h = 2
      1040042Ch = 1C2h ??? ;bootrom: 192h ?
      10400430h = 1C2h ??? ;bootrom: 192h ?
      10400434h = 1C2h ??? ;bootrom: 192h ?
      10400438h = 1
      1040043Ch = 2
      10400440h = 1960192h ;bootrom: 1930192h ?
      10400444h = 0
      10400448h = 0
      1040045Ch = 19000F0h   ;msbs=width=400, lsbs=height=240
      10400460h = 1C100D1h
      10400464h = 1920002h
      10400470h = 80340h   ;bootrom: 80040h ?
      1040049Ch = 0        ;bootrom: 1920000h ?

More Init Values from nngxInitialize for Top Screen

      10400468h = 18300000h  ;\later changed by GSP module when updating state,
      1040046Ch = 18300000h  ;/framebuffer
      10400494h = 18300000h
      10400498h = 18300000h
      10400478h = 1          ;-doesn't stay 1, read as 0
      10400474h = 10501h

Reportedly 10400478h/10400578h.bit0 "doesn't stay 1, read as 0", uh, actually that applies for ALL OTHER bits in that register, but NOT for bit0.
Further Registers
Apart from above GPU registers, the screens do also need initialization of the "LCD" registers,
3DS Video LCD Registers
plus, initialization of whatever I2C registers for each screen. Plus some MCU/I2C registers for backlight or so.

3DS GPU External Registers - Memfill and Memcopy

     ________________________________ Memory Fill ________________________________

10400010h/10400020h - GPU_MEMFILL_DST_ADDR0/1 - Memfill 0/1 Start Address
10400014h/10400024h - GPU_MEMFILL_DST_END0/1 - Memfill 0/1 End Address

      0      Unused (0)
      1-28   Physical Memory Address, in 16-byte units
      29-31  Unused (0)

10400018h/10400028h - GPU_MEMFILL_DATA0/1 - Memfill 0/1 Fill Value

      0-31   Fill Value

1040001Ch/1040002Ch - GPU_MEMFILL_CNT0/1 - Memfill 0/1 Control

      0      Start/Busy   (0=Idle/Ready, 1=Start/Busy)                        (R/W)
      1      Ready IRQ    (0=No, 1=Ready, IRQ 28h/29h) (write 0 to clear)   (R/ack)
      2-7    Unused (0)
      8-9    Fill-width   (0=16bit, 1=24bit, 2=32bit, 3=Same as 1)            (R/W)
      10-15  Unused (0)
      16-20  Unknown, 5bit, R/W                                               (R/W)
      21-31  Unused (0)

A memory fill is triggered by setting bit0 in the control register. Doing so aborts any running memory fills on that filling unit. Upon completion, the hardware clears bit0 and sets bit1 and fires interrupt PSC0/PSC1 (IRQ 28h/29h).

     ________________________________ Memory Copy ________________________________

10400C00h - GPU_MEMCOPY_SRC_ADDR - Memcopy Input physical address (R/W)
10400C04h - GPU_MEMCOPY_DST_ADDR - Memcopy Output physical address (R/W)

      0      Unused (0)
      1-28   Physical Memory Address, in 16-byte units
      29-31  Unused (0)

10400C08h - GPU_MEMCOPY_DISPLAY_SIZE - DisplayTransfer width/height(R/W)

      0-2    Unused (0)
      3-15   Input Height (in 8-pixel units, usually 240/8 for 3DS)
      16-18  Unused (0)
      19-31  Input Width  (in 8-pixel units, usually 320/8 or 400/8 for 3DS)

Input size before downscale (the output size is the same, unless downscale was used).
10400C0Ch - GPU_MEMCOPY_DISPLAY_GAP - DisplayTransfer Input height+gap (R/W)

      0-2    Unused (0)
      3-15   Input Height+Gap (in 8-pixel units, usually (240+0)/8 for 3DS)
      16-31  Unused (0)

Allows to skip input pixels, used only if GPU_MEMCOPY_FLAGS.bit2=1.
10400C10h - GPU_MEMCOPY_FLAGS - Memcopy Transfer flags (R/W)

      0      Horizontal Flip    (0=Normal, 1=Mirror)
      1      Conversion Mode    (0=TiledToLinear, 1=LinearToTiled)
      2      Input Gap          (0=Use raw height, 1=Use height+gap)
      3      Copy Mode          (0=DisplayCopy/Pixels, 1=TextureCopy/RawBytes)
      4      Unused (0)
      5      Conversion Disable (0=Convert as specified in bit1, 1=TiledToTiled)
      6-7    Unused (0)
      8-10   Input RGBA Format  (0=8888, 1=8880, 2=5650, 3=5551, 4..7=4444)
      11     Unused (0)
      12-14  Output RGBA Format (0=8888, 1=8880, 2=5650, 3=5551, 4..7=4444)
      15     Unused (0)
      16     Block Tiling Size  (0=Normal/8x8 pixels, 1=32x32 pixels)
      17-23  Unused (0)
      24-25  Output Downscale   (0=No, 1=Height/2, 2=WidthAndHeight/2, 3=Invalid)
      26-31  Unused (0)

The transfer hangs on some Input/Output RGBA combinations:

      32bit Input (8888) works with all output formats
      24bit Input (8880) works only if output is also 24bit
      16bit Input (5650/5551/4444) works only if output is also 16bit

10400C14h - GPU_MEMCOPY_UNKNOWN_21BIT - Memcopy (R/W)

      0-20   Unknown, R/W
      21-31  Unused (0)

"GSP module writes value 0 here prior to writing to 10400C18h, for cmd3."
10400C18h - GPU_MEMCOPY_CNT - Memcopy Start/Busy (R/W)

      0      Start/Busy (0=Idle/Ready, 1=Start/Busy)                          (R/W)
      1-7    Unused (0)
      8      Ready IRQ  (0=No, 1=Ready, "PPF" IRQ 2Ch) (write 0 to clear)   (R/ack)
      9-31   Unused (0)

Caution: Polling this register can HANG the ARM11 CPU at end of transfer; when using polling, it's better to wait for GPU_STAT_IRQ_FLAGS.bit30=1.
10400C1Ch - GPU_MEMCOPY_REMAIN_IRQ - Memcopy Remain IRQ (R/W)

      0-13   Transfer IRQ position (compare value for below remain counter)   (R/W)
      14-15  Unused (0)
      16-29  Transfer width remain, in 4-pixel units (3FFEh..0, or 3FFFh=done)  (R)
      30-31  Unused (0)

The IRQ position should be set to 3FFFh for triggering IRQ flag at transfer end, otherwise the IRQ would trigger before completion (or never at all).
Example: For width=320pix, remain goes through 4Fh..00h, and does then wrap to 3FFFh.
The 4-pixel unit might be due to decreasing the counter upon both reading & writing 8-pixel chunks.
Used for DisplayTransfer. And maybe also for TextureCopy?
10400C20h - GPU_MEMCOPY_TEX_SIZE - TextureCopy total amount

      0-3    Unused (0)
      4-31   Total amount of data to copy, in 16-byte units

10400C24h - GPU_MEMCOPY_TEX_SRC_WIDTH - TextureCopy input line width/gap
10400C28h - GPU_MEMCOPY_TEX_DST_WIDTH - TextureCopy output line width/gap

     For SRC_WIDTH:
      0-15   Width, in unknown units (maybe 16-byte units, same as below?)
      16-31  Gap, in 16-byte units
     For DST_WIDTH:
      0-31   Width and Gap (probably same 2x16bit format as for above SRC_WIDTH)

10400C2Ch - GPU_MEMCOPY_UNKNOWN_FLAG - Memcopy Unknown (R/W)

      0      Unknown, R/W
      1-31   Unused (0)

Notes...
"The DisplayTransfer registers are only used if FLAGS.bit3=0 and ignored otherwise. The TextureCopy registers are "likewise" only used if FLAGS.bit3=1, and ignored otherwise."
TextureCopy
When FLAGS.bit3=1, the hardware performs a TextureCopy-mode transfer. In this mode, all other bits of that register are ignored (except for FLAGS.bit2, which still needs to be set correctly?), and no format conversions are done.
Instead, it performs a raw data copy from the source to the destination, but with a configurable gap between lines. The total amount of bytes to copy is specified in the size register, and the hardware loops reading lines from the input and writing them to the output until this amount is copied. The "gap" specified in the input/output dimension register is the number of chunks to skip after each "width" chunks of the input/output, and is NOT counted towards the total size of the transfer.
By correctly calculating the input and output gap sizes it is possible to use this functionality to copy arbitrary sub-rectangles between differently-sized framebuffers or textures, which is one of its main uses over a regular no-conversion DisplayTransfer. When copying tiled textures/framebuffers it's important to remember that the contents of a tile are laid out sequentially in memory, and so this should be taken into account when calculating the transfer parameters.
Specifying invalid/junk values for the TextureCopy dimensions can result in the GPU hanging while attempting to process this TextureCopy.

3DS GPU Internal Register Overview

Aliases
It is possible for multiple register (sequential) IDs to correspond to the same register. This is done to leverage the consecutive writing mode for GPU commands, which makes it possible for a single command to write data to multiple sequential register IDs. For example, register IDs 02C1 through 02C8 all correspond to GPUREG_VSH_FLOATUNIFORM_DATAi so that a consecutively writing command based at 02C0 will write its first parameter to GPUREG_VSH_FLOATUNIFORM_INDEX and ever subsequent ones to GPUREG_VSH_FLOATUNIFORM_DATAi
Data Types

      signed          Signed integer
      unsigned        Unsigned integer
      floatX.Y.Z      Floating-point number with X sign bits, Y exponent bits,
                        and Z mantissa bits
      fixedX.Y.Z      Fixed-point number with X sign bits, Y integer bits,
                        and Z fractional bits

float1.5.10 (16bit)
float1.7.12 (20bit) (uncommon, for light attentuation)
float1.7.16 (24bit)
float1.8.23 (32bit)
float1.7.24 (32bit) (uncommon, for viewport)

3DS GPU Internal Registers - Command Lists

Commands (aka GPU registers writes) can be done by manually writing parameters to register 10401000h-10401FFFh, or by using command lists.
With the command lists, the GPU automatically reading parameters and command numbers from memory (and automatically pauses reading when it is busy).
104018E8h - PICA(023Ah) - GPUREG_CMDBUF_ADDR0 (aka entrypoint) (R/W)
104018ECh - PICA(023Bh) - GPUREG_CMDBUF_ADDR1 (aka entrypoint) (R/W)

      0      Unused (0)
      1-28   Physical address of command buffer, in 16-byte units

Set the physical address of 1st/2nd command buffer.
104018E0h - PICA(0238h) - GPUREG_CMDBUF_SIZE0 (R/W)
104018E4h - PICA(0239h) - GPUREG_CMDBUF_SIZE1 (R/W)
The size value is required to indicate the end of the command list (alternately, if GPUREG_IRQ_AUTOSTOP is enabled, command list execution will also terminate when triggering an IRQ via FINALIZE command; which is usually stored at end of command list).

      0      Unused (0)
      1-20   Size of command buffer, in 16-byte units

Observe that commands are multiples of 8 bytes (so one may need to append a dummy command for the 16-byte size boundary; unknown if there's a NOP command for that purpose; reportedly FINALIZE command(s) are used for padding, though that could trigger multiple IRQs when GPUREG_IRQ_AUTOSTOP is disabled).
104018F0h - PICA(023Ch) - GPUREG_CMDBUF_JUMP0 (jump to ADDR0) (W)
104018F4h - PICA(023Dh) - GPUREG_CMDBUF_JUMP1 (jump to ADDR0) (W)

      0-31   Don't care (writing any value starts CMDBUF execution, at ADDR0/1)

Executes the Command List, starting at CMDBUF_ADDR0/1, until reaching CMDBUF_SIZE0/1 (or until FINALIZE+AUTOSTOP).
Unknown why there are two command lists, supposedly they cannot execute simultaneously... maybe the second list is automatically started at the end of the other list?
Command List entries
Each entry in the command list does contain a "Command Header", and one or more parameter words, the entry size must be a multiple of 8 bytes.

      00h 4   1st Parameter word
      04h 4   Command Header (see below)
      08h 4   2nd Parameter word (if any)
      0Ch 4   3rd Parameter word (if any)
      ... ..  Nth Parameter word (if any)
      xxh 4   Padding (zero) (if above wasn't a multiple of 8 bytes)

Command Header:

      0-15    Command ID, PICA(0000h..03FFh)
      16      Parameter mask, update parameter bit0-7   (0=Don't change, 1=Write)
      17      Parameter mask, update parameter bit8-15  (0=Don't change, 1=Write)
      18      Parameter mask, update parameter bit16-23 (0=Don't change, 1=Write)
      19      Parameter mask, update parameter bit24-31 (0=Don't change, 1=Write)
      20-27   Number of parameter words-1 (0..FFh = 1..256 parameter words)
      28-30   Unused
      31      Consecutive writing mode (0=Fixed Command number, 1=Increasing)

3DS GPU Internal Registers - Finalize Interrupt registers

10401000h+i - PICA(N/A) - GPUREG_IRQ_ACK(0..63) (R/W)
10401040h+i - PICA(0010h..001Fh) - GPUREG_IRQ_REQ(0..63) (R/W)
10401080h+i - PICA(N/A) - GPUREG_IRQ_CMP(0..63) (R/W)

      0-7     Request/Compare Byte for IRQ#0   ;\
      8-15    Request/Compare Byte for IRQ#1   ; triggers "P3D" IRQ 2Dh if any
      16-23   Request/Compare Byte for IRQ#2   ; of the request/compare bytes
      ..      ..                               ; are same (and enabled in MASK)
      504-511 Request/Compare Byte for IRQ#63  ;/

The ACK registers are basically mirrors of the REQ registers (and ARM11 could write either one, causing IRQ acknowledge or request depending on whether the written value does match the CMP compare bytes). However, there are at least two small differences between ACK and REQ registers:

      GPU command list's can only write to GPUREG_IRQ_REQ
      ARM11 reads from GPUREG_IRQ_REQ cause ARM11 to wait if GPU is busy

Normally, CMP contains constant values, and REQ/ACK are changed to same/different values when requesting/releasing interrupt requests.
104010C0h - PICA(N/A) - GPUREG_IRQ_MASK_LOW (R/W)
104010C4h - PICA(N/A) - GPUREG_IRQ_MASK_HIGH (R/W)

      0-63   Interrupt Disable flags for IRQ#0..63   (0=Enable, 1=Disable)

104010C8h - PICA(N/A) - GPUREG_IRQ_STAT_LOW (R)
104010CCh - PICA(N/A) - GPUREG_IRQ_STAT_HIGH (R)

      0-63   Interrupt Compare flags for IRQ#0..63   (0=Mismatch, 1=Match/IRQ)

104010D0h - PICA(N/A) - GPUREG_IRQ_AUTOSTOP (R/W)

      0      Autostop upon REQ=CMP match  (0=IRQ only, 1=IRQ and Stop cmdlist)
      1-31   Unused (0)

104010D4h - PICA(N/A) - GPUREG_FIXED_00010002h (R)

      0-31   Unknown, readonly, always 00010002h (some status, or chip id or so?)

Maybe related: Port 10400000h contains the same 00010002h readonly value.
Notes
Nintendo uses the IRQ registers to trigger a "FINALIZE" interrupt at end of command list, done as so:

      GPUREG_IRQ_MASK_LOW=FFFFFFF0h set upon GPU init  ;\enable first four IRQs
      GPUREG_IRQ_MASK_HIGH=FFFFFFFFh set upon GPU init ;/
      GPUREG_IRQ_AUTOSTOP=1                            ;-autostop cmdlist upon IRQ
      GPUREG_IRQ_CMP(0)=12345678h set upon GPU init    ;-first four compare values
      GPUREG_IRQ_ACK(0)=00000000h set upon GPU init and before cmdlist
      GPUREG_IRQ_REQ(0)=12345678h set via PICA(0010h) FINALIZE at end of cmdlist

Due to the 32bit writes, that will actually trigger four byte-matches at once.
Caution:
The GPU command list can write to GPUREG_IRQ_REQ(n), but all other registers in range PICA(0000h..003Fh) are writeable by CPU only, not via command lists.

3DS GPU Internal Registers - Geometry Pipeline registers

10401978h - PICA(025Eh) - GPUREG_PRIMITIVE_CONFIG (R/W)

      0-3    Number of vertex shader output map registers - 1        ;see OUTMAP
      8-9    Primitive mode (0=Tri's, 1=Tri-Strip, 2=Tri-Fan, 3=Geometry primitive)
      16     UNKNOWN (R/W)
             __       __ ___          __ __ __
       /\   | /     /| /\  /\        /\ | / .'\    ?????????
      /__\  |/     /_|/__\/__\      /__\|/.'___\   ?????????
      0=Triangles, 1=TriangleStrip, 2=TriangleFan, 3=Geometry primitive

1040197Ch - PICA(025Fh) - GPUREG_RESTART_PRIMITIVE (R/W)

      0-31   UNKNOWN, usually 1 (writing any value works... but value is R/W)

Used to terminate a triangle strip/fan (eg. to start a new strip, instead of appending further vertices to the old strip) (note: the restart must be issued at BEGIN of each strip/fan, not at the end).
Restart occurs on writing any value... but the written value is R/W, so it might have some purpose?

     __________________________ Vertex Attribute Arrays ___________________________

ATTR_BUF arrays contain vertex attributes (such like coordinates and colors). The GPU can automatically transfer data from these arrays to the shader unit (which does then forward the data to the drawing hardware).
There are up to 12 arrays for up to 12 attributes (one can either store multiple attributes in one single array, or store different attributes in separate arrays).
10401804h - PICA(0201h) - GPUREG_ATTR_BUF_FORMAT_LOW (R/W)
10401808h - PICA(0202h) - GPUREG_ATTR_BUF_FORMAT_HIGH (R/W)

      0-3    Vertex attribute 0 type/size   ;\these 4bit values contain type/size
      4-7    Vertex attribute 1 type/size   ; type in bit0-1:
      8-11   Vertex attribute 2 type/size   ;  0 = fixed1.0.7  ;Signed byte
      12-15  Vertex attribute 3 type/size   ;  1 = fixed0.0.8  ;Unsigned byte
      16-19  Vertex attribute 4 type/size   ;  2 = fixed1.0.15 ;Signed halfword
      20-23  Vertex attribute 5 type/size   ;  3 = float1.8.23 ;Float32
      24-27  Vertex attribute 6 type/size   ; size in bit2-3:
      28-31  Vertex attribute 7 type/size   ;  0 = X           ;1D
      32-35  Vertex attribute 8 type/size   ;  1 = X,Y         ;2D
      36-39  Vertex attribute 9 type/size   ;  2 = X,Y,Z       ;3D
      40-43  Vertex attribute 10 type/size  ;  3 = X,Y,Z,W     ;4D
      44-47  Vertex attribute 11 type/size  ;/
      48-59  Fixed vertex attribute 0..11 mask flags    (0=Array, 1=Fixed?) ???
      60-63  Number of vertex attributes-1 (0..11 = 1..12 attributes)

10401800h - PICA(0200h) - GPUREG_ATTR_BUF_BASE (R/W)

      0      Unused (0)
      1-28   Base address for ATTR_BUF's and INDEX_LIST, in 16-byte units
      29-31  Unused (0)

1040180Ch+i*0Ch - PICA(0203h+3*(0..11)) - GPUREG_ATTR_BUFi_OFFSET (R/W)

      0-27   Vertex array address, with base GPUREG_ATTR_BUF_BASE, in 1-byte units

Addressing uses Base+Offset+Index (with Index from FIRST_INDEX or INDEX_LIST):

      GPUREG_ATTR_BUF_BASE*10h + GPUREG_ATTR_BUFi_OFFSET*1 + Index*ArrayEntrySize

10401810h+i*0Ch - PICA(0204h+3*(0..11)) - GPUREG_ATTR_BUFi_CONFIG_LOW (R/W)
10401814h+i*0Ch - PICA(0205h+3*(0..11)) - GPUREG_ATTR_BUFi_CONFIG_HIGH (R/W)

      0-3    Array Component 0      ;\
      4-7    Array Component 1      ; These are mapping the array component(s)
      8-11   Array Component 2      ; to vertex attribute numbers:
      12-15  Array Component 3      ;   00h..0Bh = Vertex attribute 0..11
      16-19  Array Component 4      ;   0Ch      = 4-byte padding
      20-23  Array Component 5      ;   0Dh      = 8-byte padding
      24-27  Array Component 6      ;   0Eh      = 12-byte padding
      28-31  Array Component 7      ;   0Fh      = 16-byte padding
      32-35  Array Component 8      ; Attribute 0..11 do usually refer to vertex
      36-39  Array Component 9      ; shader registers v0..v11 (unless they are
      40-43  Array Component 10     ; renumbered via "PERMUTATION"...?)
      44-47  Array Component 11     ;/
      48-55  Array Entry Size in bytes (0..FFh) ;total size of above component(s)
      56-59  Unused (0)
      60-63  Number of components in this array  (0..12) (0=Disable this array?)

Padding: Does "skip" array entries? (maybe useful when having texturing disabled, whilst still having texture info in the array?).
Reportedly there is some alignment issue/feature for padding. And also an alignment issue for components or so; maybe halfword/float32 need to be aligned? There is no alignment restriction for components that consist of bytes (eg. 3x8bit RGB does work).
104018A0h - PICA(0228h) - GPUREG_ATTR_BUF_NUMVERTICES (R/W)

      0-31   Number of vertices to render (MUL2 for DRAWELEMENTS)

Don't care for FIXEDATTRIB, needed only for ATTR_BUF's.
Counted TWICE for DRAWELEMENTS (once for index-read, and once for array-read)!
XXX are multiple arrays also counted as multiple reads?
104018B8h - PICA(022Eh) - GPUREG_ATTR_BUF_DRAWARRAYS - Increasing Indices (W)
104018BCh - PICA(022Fh) - GPUREG_ATTR_BUF_DRAWELEMENTS - With INDEX_LIST (W)
Writing to either of these registers starts sending the amount of data specified in NUMVERTICES from ATTR_BUF's to the vertex shader.

      0-31   Don't care (writing any value starts drawing from ATTR_BUF)

The only difference between DRAWARRAYS and DRAWELEMENTS are the array indices:

      DRAWARRAYS uses increasing indices, starting at GPUREG_ATTR_BUF_FIRST_INDEX.
      DRAWELEMENTS uses array indices from GPUREG_ATTR_BUF_INDEX_LIST.

104018A8h - PICA(022Ah) - GPUREG_ATTR_BUF_FIRST_INDEX (R/W)

      0-31   Starting index in ATTR_BUF arrays (usually 0, to start with 1st entry)

Used only for for DRAWARRAYS (not used for DRAWELEMENTS, which does instead read indices from the INDEX_LIST).
1040189Ch - PICA(0227h) - GPUREG_ATTR_BUF_INDEX_LIST (R/W)

      0-27   Index List address, with base GPUREG_ATTR_BUF_BASE, in 1-byte units
      31     Index List entry size (0=8bit indices, 1=16bit indices)

Used only for DRAWELEMENTS. The index list allows to re-use ATTR_BUF entries for multiple vertices (triangle strips are automatically re-using vertices from the previous triangle, however, with the index list, one can also re-use vertices from the previous strips; which can save about 50% of memory).

         __  __  __  __  __  __  __  __  __
       /\  /\  /\  /\  /\  /\  /\  /\  /\  /\      <-- First Strip
      /__\/__\/__\/__\/__\/__\/__\/__\/__\/__\...
      \  /\  /\  /\  /\  /\  /\  /\  /\            <-- Second Strip
       \/__\/__\/__\/__\/__\/__\/__\/__\...
       /\  /\  /\  /\  /\  /\  /\                  <-- Third Strp
      /__\/__\/__\/__\/__\/__\/__\...

     __________________________ Fixed Vertex Attributes ___________________________

The Fixed Attribute registers can be used in two ways:

      1) Setting attribute(s) to fixed settings (similar to FLOATUNIFORM
         registers). For example, one could re-use a shader that was
         programmed to support variable colors with fixed colors.
         Unknown if fixed settings are also working for partial attributes
         (eg. 2D graphics with X,Y coordinates and fixed Z,W values).
      2) Using [GPUREG_FIXEDATTRIB_INDEX]=0Fh does directly send vertex
         attribute(s) to the shader unit (this could be "easier" than setting
         up ATTR_BUF arrays in memory, however, in practice it is extremely
         uncomfortable (due to the weird data format with 4x24bit float values
         sent in reversed 32bit word order).

104018C8h - PICA(0232h) - GPUREG_FIXEDATTRIB_INDEX (W)

      0-3    Fixed attribute index (00h-0Bh=Index, 0Fh=immediate-mode submission)

Selects the index of the fixed attribute to be input with GPUREG_FIXEDATTRIB_DATAi.
104018CCh - PICA(0233h) - GPUREG_FIXEDATTRIB_DATA(0) (HIGH) (W)
104018D0h - PICA(0234h) - GPUREG_FIXEDATTRIB_DATA(1) (MID) (W)
104018D4h - PICA(0235h) - GPUREG_FIXEDATTRIB_DATA(2) (LOW) (W)

      0-23   float1.7.16, Vertex attribute X
      24-47  float1.7.16, Vertex attribute Y
      48-71  float1.7.16, Vertex attribute Z
      72-95  float1.7.16, Vertex attribute W

The above 96bit value is split into three 32bit words, and, weirdly,

      the word order for writing is HIGH,MID,LOW (aka big endian style)
      the byte order per 32bit word is little endian

More uncomfortably, fixed attributes must be in 4x24bit float format (with X,Y,Z,W, even when needing only X,Y, and with 24bit float, instead of more comfortable formats like 8bit/16bit integer or 32bit float)
Note: The three DATA registers are mirrors of each other, one could write the HIGH,MID,LOW words all to DATA0, or to DATA0..2.

     ________________________ Shader/Attribute/Mode Config ________________________

Below is still rather nebulous, some registers are required to be initialized as described... and some seem to be bogus (somehow having wrong descriptions and/or no function at all).
10401908h - PICA(0242h) - GPUREG_VSH_NUM_ATTR (required) (R/W)

      0-3    Number of vertex shader input attributes - 1

10401928h - PICA(024Ah) - GPUREG_VSH_OUTMAP_TOTAL1 (required) (R/W)
10401944h - PICA(0251h) - GPUREG_VSH_OUTMAP_TOTAL2 (no function?) (R/W)

      0-3    Number of vertex shader output map registers - 1

Uh, why are there TWO such registers? Is that for each command buffer? Or for GSH and VSH? Or are that something like total+remaining counts?
104018A4h - PICA(0229h) - GPUREG_GEOSTAGE_CONFIG (unknown purpose) (R/W)

      0-1    Geometry shader in use    (0=Not in use, 2=In use)
      8      Drawing triangle elements (0=Not, 1=Drawing triangle elements)
      9      UNKNOWN "0x0" (R/W)
      16-19  UNKNOWN (R/W)
      31     Use reserved geometry shader subdivision (0=Don't use, 1=Use)

"When using vertex buffers and drawing elements in triangles mode, bit8 is set to 1, else it is set to 0."
Uh, what means drawing triangle elements... does the gpu even support drawing anything else than triangles?
1040194Ch - PICA(0253h) - GPUREG_GEOSTAGE_CONFIG2 (parts required) (R/W)

      0      Function indicator
                with vertex buffers: 0=Draw elements, 1=Draw arrays     <-- blah?
                without: 0=Not inputting, 1=Inputting vertex attribute data  <--?
      8      Drawing triangle elements (0=Not, 1=Drawing triangle elements)

"When using vertex buffers, bit0 is set to 1 before drawing arrays, and cleared to 0 immediately after.
When using immediate mode to directly input vertex attribute data, bit0 is set to 1 before inputting vertex attribute data, and cleared to 0 immediately after. While bit0 is set to 1, some register writes outside of the 0x200-0x254 and 0x280-0x2DF ranges may be processed incorrectly.
When using vertex buffers and drawing elements in triangles mode, bit8 is set to 1, else it is set to 0."
10401948h - PICA(0252h) - GPUREG_GSH_MISC0 (R/W)

      0-1    Mode?      (0=Normal, 1=WhateverSubdivision?, 2=WhateverParticle?)
      8-22   Something? (0..7FFFh, for the Particle stuff?)
      24     Flag?      (0..1, for the Particle stuff?)

Reportedly 00000000h=Normal, 00000001h=Reserved geometry shader subdivision in use, 01004302h=Particle system in use.
10401950h - PICA(0254h) - GPUREG_GSH_MISC1 (R/W)

      0-4    Reserved geometry shader subdivision type (2=Loop, 3=Catmull-Clark)

"Configures the type of reserved geometry shader subdivision in use. The value is ignored when a subdivision is not in use."
104018B4h - PICA(022Dh) - GPUREG_POST_VERTEX_CACHE_NUM (R/W)

      0-7    Number of entries in post-vertex cache (unsigned, usually 04h or 84h)
      8-15   UNKNOWN (R/W)
      16-23  UNKNOWN (R/W)  ;\these two bytes are swapped when reading
      24-31  UNKNOWN (R/W)  ;/(reading mirrors also returns swapped bytes)

"Configures the post-vertex cache." Uh, what is that?
104018C4h - PICA(0231h) - GPUREG_VTX_FUNC (W)

      0-31   Trigger (0=Idle???, Non-zero=Clear post-vertex cache)

"Triggers clearing the post-vertex cache."
Uh, then, maybe should be called "clear cache" instead "vtx func". And what is a "post-vertex"? And is it really clearing anything, drawing seems to work without doing so.
10401910h - PICA(0244h) - GPUREG_VSH_COM_MODE (R/W)

      0      Geometry shader configuration enable  (0=Disable, 1=Enable)

"Sets whether to use the geometry shader configuration or reuse the vertex shader configuration for the geometry shader shading unit."
10401914h - PICA(0245h) - GPUREG_START_DRAW_FUNC0 (R/W)

      0      Mode         (0=Drawing, 1=Configuration)
      1-7    UNKNOWN "0x0" (not R/W)

"Related to drawing. When the mode value is set to 1, rendering is not performed properly. When set to 0, changes to the vertex shader configuration registers are not applied correctly. Because of this, it is usually initialized to 1, set to 0 immediately before triggering a draw, and set back to 1 immediately after triggering a draw."
1040190Ch - PICA(0243h) - GPUREG_undoc_1040190Ch (R/W=00000037h)

      0-2    UNKNOWN (0..7) (R/W)
      4-6    UNKNOWN (0..3) (R/W)

Power-up default is 37h. GPU hangs on several other settings, in some cases also depending on other registers (for example, 00h hangs only when also clearing other undocumented registers).
10401954h - PICA(0255h) - GPUREG_undoc_10401954h (R/W=00000001h)

      0      UNKNOWN (0..1) (R/W)

3DS GPU Internal Registers - Shader registers

There are four shader units, each having its own set of I/O registers:

      10401A00h - PICA(0280h..) - Shader 0 (Geometry Shader, aka GSH)
      10401AC0h - PICA(02B0h..) - Shader 1 (Vertex Shader, aka VSH)
      10401B80h - PICA(02E0h..) - Shader 2 (Unknown purpose)
      10401C40h - PICA(0310h..) - Shader 3 (Unknown purpose)

The vertex shader can reportedly use three shader units at once (or all four units, when not using the geometry shader). Even when using multiple units as vertex shader, one does only need to initialize the Shader 1 registers.
Unknown if the Shader 2 and 3 registers are having any special purpose for yet unknown special effects (maybe for the undescribed "reserved geometry shader subdivision" feature, or maybe for the "procedural texture" unit, or maybe they are just dummy registers).

     ____________________________ Input/Output Config _____________________________

10401A24h - PICA(0289h) - GPUREG_GSH_INPUTBUFFER_CONFIG (R/W)
10401AE4h - PICA(02B9h) - GPUREG_VSH_INPUTBUFFER_CONFIG (R/W)
10401BA4h - PICA(02E9h) - GPUREG_VSH2_INPUTBUFFER_CONFIG (R/W)
10401C64h - PICA(0319h) - GPUREG_VSH3_INPUTBUFFER_CONFIG (R/W)

      0-3    Number of Input vertex attributes - 1
      4-7    Unused (0)
      8      Use reserved geometry shader subdivision (0=Don't use, 1=Use) (uh?)
      9-26   Unused (0)
      27     Whatever, should be 1 for geometry shader (R/W)
      28     Whatever, should be 0                     (R/W)
      29     Whatever, should be 1 for vertex shader   (R/W)
      30     Unused (0)
      31     Whatever, should be 1 for vertex shader   (R/W)

Configures the shader unit's input buffer.
10401A2Ch - PICA(028Bh) - GPUREG_GSH_ATTR_PERMUTATION_LOW (R/W)
10401A30h - PICA(028Ch) - GPUREG_GSH_ATTR_PERMUTATION_HIGH (R/W)
10401AECh - PICA(02BBh) - GPUREG_VSH_ATTR_PERMUTATION_LOW (R/W)
10401AF0h - PICA(02BCh) - GPUREG_VSH_ATTR_PERMUTATION_HIGH (R/W)
10401BACh - PICA(02EBh) - GPUREG_VSH2_ATTR_PERMUTATION_LOW (R/W)
10401BB0h - PICA(02ECh) - GPUREG_VSH2_ATTR_PERMUTATION_HIGH (R/W)
10401C6Ch - PICA(031Bh) - GPUREG_VSH3_ATTR_PERMUTATION_LOW (R/W)
10401C70h - PICA(031Ch) - GPUREG_VSH3_ATTR_PERMUTATION_HIGH (R/W)

      0-3    Vertex attribute 0 input register index (0..15=v0..v15)
      4-7    Vertex attribute 1 input register index
      8-11   Vertex attribute 2 input register index
      12-15  Vertex attribute 3 input register index
      16-19  Vertex attribute 4 input register index
      20-23  Vertex attribute 5 input register index
      24-27  Vertex attribute 6 input register index
      28-31  Vertex attribute 7 input register index
      32-35  Vertex attribute 8 input register index
      36-39  Vertex attribute 9 input register index
      40-43  Vertex attribute 10 input register index
      44-47  Vertex attribute 11 input register index
      48-51  Vertex attribute 12 input register index  ;\uh, how does one
      52-55  Vertex attribute 13 input register index  ; set attr 12-15?
      56-59  Vertex attribute 14 input register index  ; maybe FROM
      60-63  Vertex attribute 15 input register index  ;/geometry shader?

Sets the shader unit input register index which will correspond to each attribute contained by the input buffer (which in the case of geometry shaders is the vertex shader output buffer (uh, that says that there is ONE vertex shader, and MULTIPLE geometry shaders?)) for attributes 0 through 15.
For example, having LOW.bit0-3 set to 5 means that, in the shader program, v5 will contain the input buffer's 1st attribute.
For example, having HIGH.bit0-3 set to 5 means that, in the shader program, v5 will contain the input buffer's 9th attribute.
somewhat semantic?
Uh, ATTR_PERMUTATION is a scary homebrew slang for ATTR_IDs?
10401A34h - PICA(028Dh) - GPUREG_GSH_OUTMAP_MASK (R/W)
10401AF4h - PICA(02BDh) - GPUREG_VSH_OUTMAP_MASK (R/W)
10401BB4h - PICA(02EDh) - GPUREG_VSH2_OUTMAP_MASK (R/W)
10401C74h - PICA(031Dh) - GPUREG_VSH3_OUTMAP_MASK (R/W)

      0      Output register o0  (0=Disable, 1=Enable)
      1      Output register o1  (0=Disable, 1=Enable)
      2      Output register o2  (0=Disable, 1=Enable)
      3      Output register o3  (0=Disable, 1=Enable)
      4      Output register o4  (0=Disable, 1=Enable)
      5      Output register o5  (0=Disable, 1=Enable)
      6      Output register o6  (0=Disable, 1=Enable)
      7      Output register o7  (0=Disable, 1=Enable) (vertex shader only, uh?)
      8      Output register o8  (0=Disable, 1=Enable) (vertex shader only, uh?)
      9      Output register o9  (0=Disable, 1=Enable) (vertex shader only, uh?)
      10     Output register o10 (0=Disable, 1=Enable) (vertex shader only, uh?)
      11     Output register o11 (0=Disable, 1=Enable) (vertex shader only, uh?)
      12     Output register o12 (0=Disable, 1=Enable) (vertex shader only, uh?)
      13     Output register o13 (0=Disable, 1=Enable) (vertex shader only, uh?)
      14     Output register o14 (0=Disable, 1=Enable) (vertex shader only, uh?)
      15     Output register o15 (0=Disable, 1=Enable) (vertex shader only, uh?)
      16-26  UNKNOWN (R/W)
      16-31  UNKNOWN "0x0"  (uh, but only bit27-31 are always 0)

Toggles a shader unit's output registers.
See also: GPUREG_SH_OUTMAP_Oi

     _____________________________ Uniform Registers ______________________________

Uniform registers can contain general purpose constants. That is, they are usually kept set to constant values throughout sending multiple vertices (unlike position/texture coordinates or other vertex attributes that differ on each vertex).
10401A00h - PICA(0280h) - GPUREG_GSH_BOOLUNIFORM (R/W)
10401AC0h - PICA(02B0h) - GPUREG_VSH_BOOLUNIFORM (R/W)
10401B80h - PICA(02E0h) - GPUREG_VSH2_BOOLUNIFORM (R/W)
10401C40h - PICA(0310h) - GPUREG_VSH3_BOOLUNIFORM (R/W)

      0-15   Boolean register b0..b15 value  (0=False, 1=True)
      16-27  For GSH: UNKNOWN (0..0FFFh) (R/W)  ;\unknown, but R/W mask resembles
      16-24  For VSH: UNKNOWN (0..01FFh) (R/W)  ;/GPUREG_xSH_ENTRYPOINT !
      16-31  UNKNOWN "0x7FFF"  (uh, but bit28-31 are always 0?) (for VSH: 25-31)

The sixteen 1bit boolean registers (B0..B15) can be used by conditional shader opcodes. Uh, elsewhere it's claimed that there are only eight bool registers?
Bit15 seems to be automatically set after executing shader code?
Bit16 and up seem to contain an opcode address?
10401A04h+i*4 - PICA(0281h+i) - GPUREG_GSH_INTUNIFORM_I0..I3 (R/W)
10401AC4h+i*4 - PICA(02B1h+i) - GPUREG_VSH_INTUNIFORM_I0..I3 (R/W)
10401B84h+i*4 - PICA(02E1h+i) - GPUREG_VSH2_INTUNIFORM_I0..I3 (R/W)
10401C44h+i*4 - PICA(0311h+i) - GPUREG_VSH3_INTUNIFORM_I0..I3 (R/W)

      0-7    unsigned, Integer register ii X value  aka INT.x  Loop count-1
      8-15   unsigned, Integer register ii Y value  aka INT.y  Loop starting index
      16-23  unsigned, Integer register ii Z value  aka INT.z  Loop index step
      24-31  Unused (0)

Each of the four integer registers (I0..I3) contains three 8bit integer values (X,Y,Z). The integers are used to initalize loop counters and indexing.
10401A40h - PICA(0290h) - GPUREG_GSH_FLOATUNIFORM_INDEX (W)
10401B00h - PICA(02C0h) - GPUREG_VSH_FLOATUNIFORM_INDEX (W)
10401BC0h - PICA(02F0h) - GPUREG_VSH2_FLOATUNIFORM_INDEX (W)
10401C80h - PICA(0320h) - GPUREG_VSH3_FLOATUNIFORM_INDEX (W)

      0-7    Transfer index for FLOATUNIFORM_DATA writes (0..95 = C0..C95)
      31     Transfer mode                  (0=float1.7.16, 1=float1.8.23)

10401A44h+i*4 - PICA(0291h+i) - GPUREG_GSH_FLOATUNIFORM_DATA(0..7) (W)
10401B04h+i*4 - PICA(02C1h+i) - GPUREG_VSH_FLOATUNIFORM_DATA(0..7) (W)
10401BC4h+i*4 - PICA(02F1h+i) - GPUREG_VSH2_FLOATUNIFORM_DATA(0..7) (W)
10401C84h+i*4 - PICA(0321h+i) - GPUREG_VSH3_FLOATUNIFORM_DATA(0..7) (W)
Each of the 96 float uniform registers (C0..C95) contains four float values (X,Y,Z,W). The floats can contain general purpose constants, colors, vectors, or matrices (eg. when using four such registers as matrix with 4x4 float values).
"The data format which should be written to it depends on the transfer mode set with GPUREG_SH_FLOATUNIFORM_INDEX. These registers function as a FIFO queue: after each time a 4-component uniform register is successfully set, the target register index is incremented, meaning that groups of uniforms with contiguous register IDs can be set with only one initial write to GPUREG_SH_FLOATUNIFORM_INDEX."
float24 (float1.7.16) transfer mode:
"Data should be sent by writing three words which are the concatenation of the float24 value of the uniform register's 4 components, in the "reverse order". Assuming each letter corresponds to 4 bits, the format becomes:"

      (uh, is that the aforementioned "reverse order", or is it unreversed here?)
      1st word  : ZZWWWWWW  ;uh, reverse of GPUREG_FIXEDATTRIB_DATA ??
      2nd word  : YYYYZZZZ
      3rd word  : XXXXXXYY

float32 (float1.8.23) transfer mode:
"Data should be sent by writing four words which are each the float32 value of the uniform register's 4 components, in the reverse order... uh, who/what/how is that reverse order??? probably alike as shown below (or reverse thereof?):"

      1st word  : WWWWWWWW
      2nd word  : ZZZZZZZZ
      3rd word  : YYYYYYYY
      4th word  : XXXXXXXX

     ____________________________ Opcodes and Opdesc's ____________________________

10401A28h - PICA(028Ah) - GPUREG_GSH_ENTRYPOINT (R/W)
10401AE8h - PICA(02BAh) - GPUREG_VSH_ENTRYPOINT (R/W)
10401BA8h - PICA(02EAh) - GPUREG_VSH2_ENTRYPOINT (R/W)
10401C68h - PICA(031Ah) - GPUREG_VSH3_ENTRYPOINT (R/W)

      0-15   Code entry point offset, in 32-bit words
      16-31  0x7FFF      ;maybe max/end address for error-checks?

uh, but, for GSH, R/W mask is 0FFF0FFFh.
uh, but, for VSH, R/W mask is 01FF01FFh.
10401A6Ch - PICA(029Bh) - GPUREG_GSH_CODETRANSFER_INDEX (W)
10401B2Ch - PICA(02CBh) - GPUREG_VSH_CODETRANSFER_INDEX (W)
10401BECh - PICA(02FBh) - GPUREG_VSH2_CODETRANSFER_INDEX (W)
10401CACh - PICA(032Bh) - GPUREG_VSH3_CODETRANSFER_INDEX (W)

      0-11   Target shader code offset, in WHAT units? 4-byte maybe?

Offset at which upcoming shader code data transferred through GPUREG_SH_CODETRANSFER_DATAi should be written.
10401A70h+i*4 - PICA(029Ch+i) - GPUREG_GSH_CODETRANSFER_DATA(0..7) (W)
10401B30h+i*4 - PICA(02CCh+i) - GPUREG_VSH_CODETRANSFER_DATA(0..7) (W)
10401BF0h+i*4 - PICA(02FCh+i) - GPUREG_VSH2_CODETRANSFER_DATA(0..7) (W)
10401CB0h+i*4 - PICA(032Ch+i) - GPUREG_VSH3_CODETRANSFER_DATA(0..7) (W)

      0-31   Shader instruction data

Used to transfer shader code data. These registers behave as a FIFO queue: each write to these registers writes the provided value to the GPU shader code memory bank at the offset initially set by GPUREG_SH_CODETRANSFER_INDEX. The offset in question is incremented after each write to this register.
10401A3Ch - PICA(028Fh) - GPUREG_GSH_CODETRANSFER_END (W)
10401AFCh - PICA(02BFh) - GPUREG_VSH_CODETRANSFER_END (W)
10401BBCh - PICA(02EFh) - GPUREG_VSH2_CODETRANSFER_END (W)
10401C7Ch - PICA(031Fh) - GPUREG_VSH3_CODETRANSFER_END (W)

      0-31   Don't care (writing any value works)

Unknown what that does. It seems to be needed at least once after first code upload (but is usually done after each shader code upload). Maybe enables code execution, or invalidates some cache?
10401A94h - PICA(02A5h) - GPUREG_GSH_OPDESCS_INDEX (W)
10401B54h - PICA(02D5h) - GPUREG_VSH_OPDESCS_INDEX (W)
10401C14h - PICA(0305h) - GPUREG_VSH2_OPDESCS_INDEX (W)
10401CD4h - PICA(0335h) - GPUREG_VSH3_OPDESCS_INDEX (W)

      0-11   Target shader operand descriptor offset, in WHAT units?

Uh, why 12bit wide? There are only max 128 descriptors per shader.
Offset at which upcoming shader operand descriptor data transferred through GPUREG_SH_OPDESCS_DATAi should be written.
10401A98h+i*4 - PICA(02A6h+i) - GPUREG_GSH_OPDESCS_DATA(0..7) (W)
10401B58h+i*4 - PICA(02D6h+i) - GPUREG_VSH_OPDESCS_DATA(0..7) (W)
10401C18h+i*4 - PICA(0306h+i) - GPUREG_VSH2_OPDESCS_DATA(0..7) (W)
10401CD8h+i*4 - PICA(0336h+i) - GPUREG_VSH3_OPDESCS_DATA(0..7) (W)

      0-31   Shader operand descriptor data

Used to transfer shader operand descriptor data. These registers behave as a FIFO queue: each write to these registers writes the provided value to the GPU shader operand descriptor memory bank at the offset initially set by GPUREG_SH_OPDESCS_INDEX. The offset in question is incremented after each write to this register.

3DS GPU Internal Registers - Rasterizer registers

     ____________________________ Viewport and Scissor ____________________________

10401104h - PICA(0041h) - GPUREG_VIEWPORT_V_SCALE (3DS: 240/2) (R/W)
1040110Ch - PICA(0043h) - GPUREG_VIEWPORT_H_SCALE (3DS: 320/2 or 400/2) (R/W)

      0-23   float1.7.16, size/2

Used to scale the vertex coordinates (usually in range -1.0 to +1.0) to screen coordinates (in pixel units). Should be set to "H=width/2" and "V=height/2". Normally that would be the screen size (or for smaller windows, the scissor area size).
10401108h - PICA(0042h) - GPUREG_VIEWPORT_V_STEP (3DS: 2/240) (R/W)
10401110h - PICA(0044h) - GPUREG_VIEWPORT_H_STEP (3DS: 2/320 or 2/400) (R/W)

      0-31   float1.7.24, 2/size

Used as stepping offsets when interpolating colors (and textures?) between vertex coordinates. Should be set to same settings as in WIDTH and HEIGHT registers, but with "inverse" division, ie. "H=2/width" and "V=2/height" (instead of "width/2" and "height/2").
For the odd floating point format, one could adjust one of the more common formats (assuming sign=0 for the latter two cases):

      (float24)*100h                  ;convert float1.7.16 to float1.7.24
      (float32)*2-40000000h           ;convert float1.8.23 to float1.7.24
      (float64)/10000000h-0C0000000h  ;convert float1.11.52 to float1.7.24

or it might also work to directly use screen coordinates for vertices (and set all viewport registers to 1.0).
10401194h - PICA(0065h) - GPUREG_SCISSORTEST_MODE (R/W)

      0-1    Mode (0=Disable, 1=Render Outside, 3=Render Inside, 2=Same as 0)

Allows to disable the scissor feature (ie. to render to render to whole framebuffer), or to select whether to render only inside, or only outside of the scissor rectangle. This can be useful if the framebuffer is divided into smaller windows.
10401198h - PICA(0066h) - GPUREG_SCISSORTEST_POS1 (R/W)
1040119Ch - PICA(0067h) - GPUREG_SCISSORTEST_POS2 (R/W)

      0-9    Vertical Position   (unsigned, 0..3FFh pixels)  ;0..240-1
      16-25  Horizontal Position (unsigned, 0..3FFh pixels)  ;0..320-1 or 0..400-1

Defines the scissor area, ranging from POS1=origin to POS2=origin+size-1 (whereas, coordinate 0,0 is lower-right).
104011A0h - PICA(0068h) - GPUREG_VIEWPORT_XY (R/W)

      0-9    Vertical Position   (signed, -200h..+1FFh pixels)
      16-25  Horizontal Position (signed, -200h..+1FFh pixels)

Default is 0,0 (with coordinate 0,0 being at center of framebuffer). Nonzero values can cause polygons to wrap at the framebuffer edges (unless scissor test is used, with position plus scissor size being within framebuffer dimensions).

     ____________________________________ Misc ____________________________________

10401100h - PICA(0040h) - GPUREG_FACECULLING_CONFIG (R/W)

      0-1    Culling (0=Show Front+Back, 1=Show Back, 2=Show Front, 3=Same as 0)

Selects whether to show the polygon front/back sides. Normally only the front side is needed (and it's thus faster not to render the back side).
Note: The hardware detects front/back by checking whether the triangle's coordinates are arranged clockwise or anti-clockwise on screen.
1040111Ch - PICA(0047h) - GPUREG_FRAGOP_CLIP (R/W)

      0      Enable clipping plane(s?) (0=Disable, 1=Enable)

10401120h+i*4 - PICA(0048h+i) - GPUREG_FRAGOP_CLIP_DATAi (i=0..3) (R/W)

      0-23   float1.7.16, Clipping plane coefficient i

"Used to configure clipping plane coefficients."
Note: There is a similar poorly described feature in OpenGL, but it's unknown what it does and how to use it. It does somehow add another clipping plane (additionally to the left/right, top/bottom, and near/far clipping plane).
10401134h - PICA(004Dh) - GPUREG_DEPTHMAP_SCALE (R/W)

      0-23   float1.7.16, Near - Far             ;default would be Z=-0.99999999

Used to configure the depth range scale.
Uh, what means map, hmmm, maybe it just means "bitmap" with depth values?
Maybe defines the visible depth range? In Z or W units? But why called scale?
Maybe also "scales" float values to 24bit integers in depth buffer?
10401138h - PICA(004Eh) - GPUREG_DEPTHMAP_OFFSET (R/W)

      0-23   float1.7.16, Near + Polygon Offset  ;default would be Z=+0.0

Used to configure the depth range bias.
Probably defines near clipping plane, in Z or W units? Unknown what "Polygon Offset" refers to.
104011B4h - PICA(006Dh) - GPUREG_DEPTHMAP_ENABLE (R/W)

      0      Enable depth range, uh what? (0=Disable/What??, 1=Enable/Default)

     ________________________________ Early Depth _________________________________

Early Depth is something about drawing only depth values (without computing and drawing colors/textures) for pre-checking if the polygon is visible... if so, something is probably required to actually draw the color/texture part...?
10401184h - PICA(0061h) - GPUREG_EARLYDEPTH_FUNC (R/W)

      0-1    Early depth function (0=GreaterEqual, 1=Greater, 2=LessEqual, 3=Less)

Configures the early depth test function.
10401188h - PICA(0062h) - GPUREG_EARLYDEPTH_TEST1 (R/W)
10401460h - PICA(0118h) - GPUREG_EARLYDEPTH_TEST2 (R/W)

      0      Enable early depth test    (0=Disable, 1=Enable)

1040118Ch - PICA(0063h) - GPUREG_EARLYDEPTH_CLEAR (W)

      0      Trigger (0=Idle???, 1=Clear) (W)   ;read=Always 0

Triggers clearing the early depth data. Whatever that means, probably something for restarting a new early depth test (whatever, it does NOT memfill the DEPTHBUFFER).
104011A8h - PICA(006Ah) - GPUREG_EARLYDEPTH_DATA (R/W)

      0-23   Early depth Clear value (unsigned)

     _______________________________ Shader Output ________________________________

1040113Ch - PICA(004Fh) - GPUREG_SH_OUTMAP_TOTAL (R/W)

      0-2    Number of shader output attributes (1..7)

10401140h+i*4 - PICA(0050h+i) - GPUREG_SH_OUTMAP_Oi (i=0..6) (R/W)

      0-4    Semantic for the x component of the register (0..1Fh, see below)
      8-12   Semantic for the y component of the register (0..1Fh, see below)
      16-20  Semantic for the z component of the register (0..1Fh, see below)
      24-28  Semantic for the w component of the register (0..1Fh, see below)

These registers map components of the corresponding vertex shader output register (o0..o6) to specific fixed-function semantics.
Semantic values:

      00h = position.x         ;\
      01h = position.y         ; Vertex Position
      02h = position.z         ;
      03h = position.w         ;/
      04h = normquat.x         ;\
      05h = normquat.y         ; Quaternion specifying the normal/tangent frame
      06h = normquat.z         ; (for fragment lighting)
      07h = normquat.w         ;/
      08h = color.r            ;\
      09h = color.g            ; Vertex color
      0Ah = color.b            ;
      0Bh = color.a            ;/
      0Ch = texcoord0.u        ;\Texture coordinates for texture 0
      0Dh = texcoord0.v        ;/
      0Eh = texcoord1.u        ;\Texture coordinates for texture 1
      0Fh = texcoord1.v        ;/
      10h = texcoord0.w        ;-Texture coordinate.w for texture 0
      12h = view.x             ;\
      13h = view.y             ; View vector (for fragment lighting)
      14h = view.z             ;/
      16h = texcoord2.u        ;\Texture coordinates for texture 2
      17h = texcoord2.v        ;/
      1Fh = Unused component   ;-for unused components of the output register

Observe that the X,Y,Z,W positions require Z,W even for simple 2D graphics (Z should be -1.0..+0.0 to pass near/far clipping, W should be +1.0 to avoid perspective division of the X,Y,Z values).
104011BCh - PICA(006Fh) - GPUREG_SH_OUTATTR_CLOCK (R/W)

      0      'position.z' present                   (0=Absent, 1=Present)
      1      'color' component present              (0=Absent, 1=Present)
      8      'texcoord0' component present          (0=Absent, 1=Present)
      9      'texcoord1' component present          (0=Absent, 1=Present)
      10     'texcoord2' component present          (0=Absent, 1=Present)
      11-15  UNKNOWN (R/W)
      16     'texcoord0.w' present                  (0=Absent, 1=Present)
      17     UNKNOWN (R/W)
      24     'normquat' or 'view' component present (0=Absent, 1=Present)

Controls the clock supply to parts relating to certain attributes.
somewhat semantic?
10401190h - PICA(0064h) - GPUREG_SH_OUTATTR_MODE (R/W)

      0      Use texture coordinates (0=Don't use, 1=Use)

Configures the shader output attribute mode, uh?

     ________________________________ Undocumented ________________________________

10401114h - PICA(0045h) - GPUREG_undoc_10401114h (R/W=00FFFFFFh)
10401118h - PICA(0046h) - GPUREG_undoc_10401118h (R/W=00FFFFFFh)

      0-23   UNKNOWN (0..FFFFFFh) (R/W)

10401130h - PICA(004Ch) - GPUREG_undoc_10401130h (R/W=00000001h)

      0      UNKNOWN (0..1) (R/W)

10401160h - PICA(0058h) - GPUREG_undoc_10401160h (R/W=00000101h)

      0      Flat Shading (0=Interpolate Colors, 1=Flat Uni-Color)
      8      UNKNOWN (0..1) (R/W)

The Flat Uni-Color mode uses only the third (last) color of each triangle.
Unknown if that does also apply to colors calculated from light vectors.
10401164h - PICA(0059h) - GPUREG_undoc_10401164h (R/W=00000001h)

      0      UNKNOWN (0..1) (R/W)

10401180h - PICA(0060h) - GPUREG_undoc_10401180h (R/W=00000301h)

      0      UNKNOWN (0..1) (R/W)
      8-9    Draw pixel(s) (0=All/Normal, 1=Each 2nd, 2=Each 4th, 3=Same as 0)

Allows to draw only each 2nd/4th pixel within 2x2 pixel cells (resulting in striped/dotted output).
104011A4h - PICA(0069h) - GPUREG_undoc_104011A4h (R/W=FFFF0001h)

      0      UNKNOWN (0..1) (R/W)
      16-31  UNKNOWN (0..FFFFh) (R/W)

104011ACh - PICA(006Bh) - GPUREG_undoc_104011ACh (R/W=00000FFFh)

      0-11   UNKNOWN (0..FFFh) (R/W)

104011B0h - PICA(006Ch) - GPUREG_undoc_104011B0h (DANGER, hangs when reading)

      0-31   UNKNOWN/DANGER, hangs when reading (maybe a fifo, hangs when empty?)

     ___________________________________ Status ___________________________________

10401168h - PICA(005Ah) - GPUREG_STAT_NUM_VERTICES_RECEIVED (R)
1040116Ch - PICA(005Bh) - GPUREG_STAT_NUM_TRIANGLES_RECEIVED (R)
10401170h - PICA(005Ch) - GPUREG_STAT_NUM_TRIANGLES_DISPLAYED (R)
Indicates the number of processed vertices/triangles, the third counter does increment only on actually displayed triangles (ie. when having passed the front/back check) (and maybe further checks, like screen/scissor area).

      0-xx?  Status counter (incrementing)

Note: Reading from these registers (or any other GPU registers at 10401040h..1040107Fh or 10401100h..10401FFFh) does cause ARM11 to wait until rendering has finished.

3DS GPU Internal Registers - Framebuffer registers

10401400h - PICA(0100h) - GPUREG_COLOR_OPERATION (R/W)

      0-1    Fragment operation mode    (0=Default, 1=Gas, 2=?, 3=Shadow)
      8      Blend mode                 (0=Logic op, 1=Blend)
      16-23  Unused, reportedly E4h ?   (isn't R/W... maybe write-only?)
      24     Render only each 2nd line  (0=All lines, 1=Only each 2nd line)
      25     Render nothing?            (0=Render, 1=Nothing)

10401404h - PICA(0101h) - GPUREG_BLEND_FUNC (R/W)

      0-2    RGB equation   (0=Add, 1=Sub, 2=ReverseSub, 3=Min, 4=Max, 5/6/7=Add)
      8-10   Alpha equation (0=Add, 1=Sub, 2=ReverseSub, 3=Min, 4=Max, 5/6/7=Add)
      16-19  RGB source blending function         (00h..0Fh, see below)
      20-23  RGB destination blending function    (00h..0Fh, see below)
      24-27  Alpha source blending function       (00h..0Fh, see below)
      28-31  Alpha destination blending function  (00h..0Fh, see below)

Blending Function values:

      0h = Zero
      1h = One
      2h = Source color
      3h = One minus source color
      4h = Destination color
      5h = One minus destination color
      6h = Source alpha                 ;<-- use for source func's?
      7h = One minus source alpha       ;<-- use for dest func's?
      8h = Destination alpha
      9h = One minus destination alpha
      Ah = Constant color               ;<-- aka GPUREG_BLEND_COLOR maybe?
      Bh = One minus constant color
      Ch = Constant alpha
      Dh = One minus constant alpha
      Eh = Source alpha saturate        ;<-- uh?
      Fh = ?

Unknown what source/dest means, maybe source=polygon, dest=colorbuf?
Unknown if there's a way to disable blending (other than using ADD+Zero).
Selecting things like "Source alpha" as RGB func seems to mean "color*alpha"?
Unknown if this (or other registers) allow anti-aliasing.
10401408h - PICA(0102h) - GPUREG_LOGIC_OP (R/W)

      0-3    Logic op (0..0Fh, see below)

Logic op values:

      0h = Clear
      1h = AND
      2h = Reverse AND
      3h = Copy
      4h = Set
      5h = Inverted copy
      6h = Noop
      7h = Invert
      8h = NAND
      9h = OR
      Ah = NOR
      Bh = XOR
      Ch = Equivalent
      Dh = Inverted AND
      Eh = Reverse OR
      Fh = Inverted OR

Uh, what does that crap mean, and when is it used what for?
1040140Ch - PICA(0103h) - GPUREG_BLEND_COLOR (R/W)

      0-7    Red    (unsigned, 00h..FFh)
      8-15   Green  (unsigned, 00h..FFh)
      16-23  Blue   (unsigned, 00h..FFh)
      24-31  Alpha  (unsigned, 00h..FFh)

10401410h - PICA(0104h) - GPUREG_FRAGOP_ALPHA_TEST (R/W)

      0      Alpha Testing Enable     (0=Disable, 1=Enable)
      4-6    Alpha Testing Function   (0-7, see below)
      8-15   Alpha Reference value    (00h..FFh, unsigned)

Alpha Testing Function values:

      0h = Never
      1h = Always
      2h = Equal
      3h = Not equal
      4h = Less than
      5h = Less than or equal
      6h = Greater than
      7h = Greater than or equal

10401414h - PICA(0105h) - GPUREG_STENCIL_TEST (R/W)

      0      Stencil Testing Enable    (0=Disable, 1=Enable)
      4-6    Stencil Testing Function  (0-7, see below)
      8-15   Buffer mask               (unsigned, 00h..FFh)
      16-23  Reference value           (signed, -80h..+7Fh)
      24-31  Mask                      (unsigned, 00h..FFh)

Stencil Testing Function values:

      0h = Never
      1h = Always
      2h = Equal
      3h = Not equal
      4h = Less than
      5h = Less than or equal
      6h = Greater than
      7h = Greater than or equal

10401418h - PICA(0106h) - GPUREG_STENCIL_OP (R/W)

      0-2    Stencil Fail operation   (0..7, see below)
      4-6    Stencil Z-fail operation (0..7, see below)
      8-10   Stencil Z-pass operation (0..7, see below)

Operation values:

      0h = Keep
      1h = Zero
      2h = Replace
      3h = Increment
      4h = Decrement
      5h = Invert
      6h = Increment and wrap
      7h = Decrement and wrap

1040141Ch - PICA(0107h) - GPUREG_DEPTH_COLOR_MASK (R/W)

      0      Depth test enable   (0=Disable, 1=Enable)  ;\Depth testing
      4-6    Depth function      (0..7, see below)      ;/
      8      Red write enable    (0=Disable, 1=Enable)  ;\
      9      Green write enable  (0=Disable, 1=Enable)  ; Color Buffer writing
      10     Blue write enable   (0=Disable, 1=Enable)  ;
      11     Alpha write enable  (0=Disable, 1=Enable)  ;/
      12     Depth write enable  (0=Disable, 1=Enable)  ;-Depth Buffer writing

Depth function values:

      0h = Never
      1h = Always (same as when depth test is disabled)
      2h = Equal
      3h = Not equal
      4h = Less than
      5h = Less than or equal
      6h = Greater than
      7h = Greater than or equal

10401440h - PICA(0110h) - GPUREG_RENDERBUFFER_INVALIDATE (forget cache) (W)
10401444h - PICA(0111h) - GPUREG_RENDERBUFFER_FLUSH (cache writeback) (W)

      0      Trigger (0=No change, 1=Trigger) (W)
      1-31   Unused (0)

INVALIDATE: Forgets Color/Depth Cache contents (should be used before changing buffer base addresses, or before externally MEMFILL'ing the Color/Depth buffers).
FLUSH: Copies Color/Depth Cache to memory (should be used before MEMCOPY'ing the Color Buffer to LCD Framebuffer).
10401448h - PICA(0112h) - GPUREG_COLORBUFFER_READING - Allow Read (R/W)
1040144Ch - PICA(0113h) - GPUREG_COLORBUFFER_WRITING - Allow Write (R/W)

      0-3    Allow read/write (00h=Disable, 0Fh=Enable, 01h..0Eh=Same as 0Fh?)

Write disable prevents polygon drawing. Unknown what happens on read disable.
Note: Disable stops the counters at 10400098h/1040009Ch.
10401450h - PICA(0114h) - GPUREG_DEPTHBUFFER_READING - Allow READ (R/W)
10401454h - PICA(0115h) - GPUREG_DEPTHBUFFER_WRITING - Allow WRITE (R/W)

      0      Allow stencil read/write (0=Disable, 1=Enable)
      1      Allow depth read/write   (0=Disable, 1=Enable)

Note: Disable stops the counters at 10400090h/10400094h.
10401458h - PICA(0116h) - GPUREG_DEPTHBUFFER_FORMAT (R/W)

      0-1    Format (0=16bitDepth, 1=?, 2=24bitDepth, 3=24bitDepth+8bitStencil)

Configures the depth buffer data format.
1040145Ch - PICA(0117h) - GPUREG_COLORBUFFER_FORMAT (R/W)

      0-1    Pixel size (0=16bitColor, 2=32bitColor, 1/3=?)
      16-18  Format     (0=RGBA8/Gas, 2=RGB5A1, 3=RGB565, 4=RGBA4, 1/5/6/7=?)

Configures the color buffer data format. Color components are laid out in reverse byte order in memory, with the most significant bits used first. uh, maybe that refers to two 16bit pixels within one 32bit word?
1040146Ch - PICA(011Bh) - GPUREG_RENDERBUFFER_BLOCK32 (R/W)

      0      Render buffer block size (0=Normal/8x8 pixels, 1=32x32 pixels)

Should be set to 8x8 (the 32x32 pixel mode can be reportedly used with GPU_MEMCOPY_FLAGS.bit16=1, but 32x32 won't match up with the 400x240 and 320x240 pixel 3DS screens)
10401470h - PICA(011Ch) - GPUREG_DEPTHBUFFER_LOC (R/W)
10401474h - PICA(011Dh) - GPUREG_COLORBUFFER_LOC (R/W)

      0-2    UNKNOWN, seems to have no effect (R/W)
      3-27   Buffer physical address, in 64-byte units

These registers configure the depth/color buffer physical addresses. The buffers are reportedly divided into 8x8 pixel blocks (or optionally 32x32 pixel), that tiled format does supposedly improve cache hits when drawing small polygons.
The color buffer can contain RGBA values. After rendering, these should be copied to LCD framebuffer(s) using GPU_MEMCOPY registers (which can convert the color format, and convert tiled memory to linear order.
The depth buffer can contain Depth and Stencil values. Unknown if the Depth values are float or integer values, and unknown if they are Z or W values (or if either one is selectable).
10401478h - PICA(011Eh) - GPUREG_RENDERBUFFER_DIM_0 (R/W)
104011B8h - PICA(006Eh) - GPUREG_RENDERBUFFER_DIM_1 (R/W)

      0-10   Height     (unsigned, 0..7FFh) (usually 240 on 3DS)
      12-21  Width - 1  (unsigned, 0..3FFh) (usually 320-1 or 400-1 on 3DS)
      24     Negate Y-coordinates  (0=Mirror; horizontally on 3DS, 1=Default)

Configures the size of the COLORBUFFER and DEPTHBUFFER. The DIM_0 and DIM_1 registers should be usually set to the same value (although DIM_0 seems to be needed, DIM_1 seems to have no effect).
10401434h - PICA(010Dh) - GPUREG_undoc_10401434h (R/W=00000001h)

      0      UNKNOWN (0..1) (R/W)

10401438h - PICA(010Eh) - GPUREG_undoc_10401438h (R/W=FFFFFFFFh)
1040143Ch - PICA(010Fh) - GPUREG_undoc_1040143Ch (R/W=FFFFFFFFh)

      0-31   UNKNOWN (0..FFFFFFFFh) (R/W)

10401464h - PICA(0119h) - GPUREG_undoc_10401464h (R/W=FFFFFFFFh)
10401468h - PICA(011Ah) - GPUREG_undoc_10401468h (R/W=FFFFFFFFh)

      0-31   UNKNOWN (0..FFFFFFFFh) (R/W)

1040147Ch - PICA(011Fh) - GPUREG_undoc_1040147Ch (R/W=7FFFFFFFh)

      0-30   UNKNOWN (0..7FFFFFFFh) (R/W)

Power-up default is 00020200h, should be set to 00010140h. GPU hangs when set to 7FFFFFFFh. Value 1FFFFFFFh can cause a few dirt pixels upon polygon rendering. Guess: Maybe some PLL timing or memory waitstate/cache stuff?
10401480h - PICA(0120h) - GPUREG_GAS_LIGHT_XY - Planar Shading (R/W)
10401484h - PICA(0121h) - GPUREG_GAS_LIGHT_Z - View Shading (R/W)

      0-7    shading minimum intensity   (unsigned, 00h..FFh)
      8-15   shading maximum intensity   (unsigned, 00h..FFh)
      16-23  shading density attenuation (unsigned, 00h..FFh)

10401488h - PICA(0122h) - GPUREG_GAS_LIGHT_Z_COLOR (R/W)

      0-7    View shading effect in line-of-sight direction (unsigned, 00h..FFh)
      8      Gas color LUT input    (0=Gas density, 1=Light factor)

Configures gas light shading in the line-of-sight direction, and the input to the gas color LUT.
1040148Ch - PICA(0123h) - GPUREG_GAS_LUT_INDEX (W)

      0-15   Index... uh does that really have 16bit range? (W)

Index for writing GPUREG_GAS_LUT_DATAi.
10401490h - PICA(0124h) - GPUREG_GAS_LUT_DATA (R/W)

      0-31   LUT data

These registers behave as a FIFO queue. Each write to these registers writes the provided value to the gas look-up table, starting at the index selected with GPUREG_GAS_LUT_INDEX. Uh, how many registers are "these registers"?
Gas Look-Up Table (16 elements):

     First 8 elements:
      0-7    Red    (signed, -80h..+7Fh)
      8-15   Green  (signed, -80h..+7Fh)
      16-23  Blue   (signed, -80h..+7Fh)
     Last 8 elements:
      0-7    Red    (unsigned, 00h..FFh)
      8-15   Green  (unsigned, 00h..FFh)
      16-23  Blue   (unsigned, 00h..FFh)

10401494h - PICA(0125h) - GPUREG_undoc_10401494h (R/W=0000FFFFh)

      0-15   UNKNOWN (0..FFFFh) (R/W)

10401498h - PICA(0126h) - GPUREG_GAS_DELTAZ_DEPTH (R/W)

      0-23   Depth direction attenuation proportion (fixed0.16.8)
      24-25  Depth function (0..3, see below)

Configures the gas depth direction attenuation proportion, as well as the gas depth function.

     Gas depth function values:
      0h = Never
      1h = Always
      2h = Greater than/Greater than or equal            ;uh?
      3h = Less than/Less than or equal/Equal/Not equal  ;uh??

104014C0h - PICA(0130h) - GPUREG_FRAGOP_SHADOW (R/W)

      0-15   float1.5.10, Sum of penumbra scale and penumbra bias
      16-31  float1.5.10, Penumbra scale with reversed sign

Configures shadow properties.
104014FCh - PICA(013Fh) - GPUREG_undoc_104014FCh (R/W=0000000Fh)

      0-15   UNKNOWN (0..0Fh) (R/W)

3DS GPU Internal Registers - Texturing registers (Generic Textures)

10401200h - PICA(0080h) - GPUREG_TEXUNIT_CONFIG (R/W)

      0      Texture 0 enable      (0=Disable, 1=Enable)                    (R/W)
      1      Texture 1 enable      (0=Disable, 1=Enable)                    (R/W)
      2      Texture 2 enable      (0=Disable, 1=Enable)                    (R/W)
      3      UNKNOWN "0x0" (R/W)                                            (R/W)
      8-9    Texture 3 coordinates (0=Texture0, 1=Texture1, 2=Texture2)     (R/W)
      10     Texture 3 enable      (0=Disable, 1=Enable)                    (R/W)
      12     UNKNOWN "0x1" (R/W)                                            (R/W)
      13     Texture 2 coordinates (0=Texture2, 1=Texture1)                 (R/W)
      16     Clear texture cache   (0=No change, 1=Clear)                   (W)
      17-31  0x0, uh, what???                                               (??)
      24-25  UNKNOWN (R/W)                                                  (R/W)

10401204h - PICA(0081h) - GPUREG_TEXUNIT0_BORDER_COLOR (R/W)
10401244h - PICA(0091h) - GPUREG_TEXUNIT1_BORDER_COLOR (R/W)
10401264h - PICA(0099h) - GPUREG_TEXUNIT2_BORDER_COLOR (R/W)

      0-7    Border color Red    (unsigned, 00h..FFh)
      8-15   Border color Green  (unsigned, 00h..FFh)
      16-23  Border color Blue   (unsigned, 00h..FFh)
      24-31  Border color Alpha  (unsigned, 00h..FFh)

10401208h - PICA(0082h) - GPUREG_TEXUNIT0_DIM (R/W)
10401248h - PICA(0092h) - GPUREG_TEXUNIT1_DIM (R/W)
10401268h - PICA(009Ah) - GPUREG_TEXUNIT2_DIM (R/W)

      0-10   Texture dimension Height (unsigned, 0..7FFh)
      11-15  UNKNOWN (R/W)
      16-26  Texture dimension Width  (unsigned, 0..7FFh)

1040120Ch - PICA(0083h) - GPUREG_TEXUNIT0_PARAM (R/W)
1040124Ch - PICA(0093h) - GPUREG_TEXUNIT1_PARAM (R/W)
1040126Ch - PICA(009Bh) - GPUREG_TEXUNIT2_PARAM (R/W)

      0      UNKNOWN (R/W)
      1      Magnification filter   (0=Nearest, 1=Linear)
      2      Minification filter    (0=Nearest, 1=Linear)
      3      UNKNOWN (R/W)
      4-5    ETC1   (0=NotETC1, 2=ETC1, 1/3=?)  ;note: still 0 for ETC1A4
      6-7    UNKNOWN (R/W)
      8-10   Wrap T (0=ClampToEdge, 1=ClampToBorder, 2=Repeat, 3=MirroredRepeat)
      11     UNKNOWN (R/W)
      12-14  Wrap S (0=ClampToEdge, 1=ClampToBorder, 2=Repeat, 3=MirroredRepeat)
      15     UNKNOWN (R/W)
      16-17  UNKNOWN "0x0" (R/W)
      18-19  UNKNOWN (R/W)
      20     TEXUNIT0 only: Shadow (0=No, 1=Shadow)
      20     TEXUNIT1/2: UNKNOWN (R/W)
      21-23  UNKNOWN (R/W)
      24     Mipmap filter          (0=Nearest, 1=Linear)
      28-30  TEXUNIT0 only: Type   (see below)
      28-30  TEXUNIT1/2: Unused (0)

Type values:

      0=2D, 1=CubeMap, 2=Shadow2D, 3=Projection, 4=ShadowCube, 5=Disabled

10401210h - PICA(0084h) - GPUREG_TEXUNIT0_LOD (R/W)
10401250h - PICA(0094h) - GPUREG_TEXUNIT1_LOD (R/W)
10401270h - PICA(009Ch) - GPUREG_TEXUNIT2_LOD (R/W)

      0-12   fixed1.4.8, Bias
      13-15  UNKNOWN (R/W)
      16-19  Max Level of Detail (max LOD) (unsigned, 0..0Fh = ?)
      20-23  UNKNOWN (R/W)
      24-27  Min Level of Detail (min LOD) (unsigned, 0..0Fh = ?)

10401214h - PICA(0085h) - GPUREG_TEXUNIT0_ADDR1 (R/W)
10401218h - PICA(0086h) - GPUREG_TEXUNIT0_ADDR2 (R/W)
1040121Ch - PICA(0087h) - GPUREG_TEXUNIT0_ADDR3 (R/W)
10401220h - PICA(0088h) - GPUREG_TEXUNIT0_ADDR4 (R/W)
10401224h - PICA(0089h) - GPUREG_TEXUNIT0_ADDR5 (R/W)
10401228h - PICA(008Ah) - GPUREG_TEXUNIT0_ADDR6 (R/W)
10401254h - PICA(0095h) - GPUREG_TEXUNIT1_ADDR (R/W)
10401274h - PICA(009Dh) - GPUREG_TEXUNIT2_ADDR (R/W)
First ADDR register, PICA(0085h,0095h,009Dh):

      0-27   Texture physical memory address, in 8-byte units (full 28bits)

Subsequent ADDR registers, PICA(0086h..008Ah):

      0-21   Texture physical memory address, in 8-byte units (lower 22bits)
             (upper 6bits are reused from first ADDR register)

Individual texels in a texture are laid out in memory as a Z-order curve. Mipmap data is stored directly following the main texture data.
If the texture is a cube:

      Register Description
      ADDR1    Positive X
      ADDR2    Negative X
      ADDR3    Positive Y
      ADDR4    Negative Y
      ADDR5    Positive Z
      ADDR6    Negative Z

Otherwise, ADDR(1) points to a 2D texture, and the rest are empty.
1040122Ch - PICA(008Bh) - GPUREG_TEXUNIT0_SHADOW (R/W)

      0      Perspective (0=Perspective, 1=Not perspective)
      1-23   fixed0.0.24, Z bias (upper 23 bits) (uh, how can that have 24bit?)
      24-31  UNKNOWN (R/W)

"Texture unit's shadow texture properties."
10401230h - PICA(008Ch) - GPUREG_undoc_10401230h (R/W=FFFF00FFh)

      0-7    UNKNOWN (0..FFh) (R/W)
      16-31  UNKNOWN (0..FFFFh) (R/W)

10401234h - PICA(008Dh) - GPUREG_undoc_10401234h (R/W=000000FFh)

      0-7    UNKNOWN (0..FFh) (R/W)

10401238h - PICA(008Eh) - GPUREG_TEXUNIT0_TYPE (R/W)
10401258h - PICA(0096h) - GPUREG_TEXUNIT1_TYPE (R/W)
10401278h - PICA(009Eh) - GPUREG_TEXUNIT2_TYPE (R/W)

      0-3    Texture Data Format

Format values:

      00h = RGBA8888        GL_RGBA            GL_UNSIGNED_BYTE
      01h = RGB888          GL_RGB             GL_UNSIGNED_BYTE
      02h = RGBA5551        GL_RGBA            GL_UNSIGNED_SHORT_5_5_5_1
      03h = RGB565          GL_RGB             GL_UNSIGNED_SHORT_5_6_5
      04h = RGBA4444        GL_RGBA            GL_UNSIGNED_SHORT_4_4_4_4
      05h = IA8             GL_LUMINANCE_ALPHA GL_UNSIGNED_BYTE
      06h = HILO8
      07h = I8              GL_LUMINANCE       GL_UNSIGNED_BYTE
      08h = A8              GL_ALPHA           GL_UNSIGNED_BYTE
      09h = IA44            GL_LUMINANCE_ALPHA GL_UNSIGNED_BYTE_4_4_EXT
      0Ah = I4
      0Bh = A4              GL_ALPHA           GL_UNSIGNED_NIBBLE_EXT
      0Ch = ETC1            GL_ETC1_RGB8_OES
      0Dh = ETC1A4

3DS GPU Internal Registers - Texturing registers (Procedural Texture)

These registers are for "Procedural Texture", whatever that means. Probably something for automatically generating or animating plasma/fire/water textures.
As far as known, these are controlled solely by the parameters in the registers below (without actually using/supporting custom program code on the shader units or so).
See GPUREG_TEXUNIT_CONFIG.bit8,9,10 for enable flag... and for selecting coordinates from texture unit 0, 1, or 2. Unknown what those coordinates are used for... as additional incoming PROCTEX parameters, or maybe the PROCTEX unit does output coordinates to the selected texture unit?
104012A0h - PICA(00A8h) - GPUREG_TEXUNIT3_PROCTEX0 (R/W)

      0-2    U-direction clamp       ;\clamp, see below
      3-5    V-direction clamp       ;/
      6-9    RGB mapping function    ;\function, see below
      10-13  Alpha mapping function  ;/
      14     Handle alpha separately   (0=Don't separate, 1=Separate)
      15     Noise enable              (0=Disable, 1=Enable)
      16-17  U-direction shift         (0=None, 1=Odd, 2=Even, 3=?)
      18-19  V-direction shift         (0=None, 1=Odd, 2=Even, 3=?)
      20-27  Texture bias (lower 8bit of float1.5.10) (upper 8bit are in PROCTEX4)

Clamp values:

      00h = Clamp to zero
      01h = Clamp to edge
      02h = Symmetrical repeat
      03h = Mirrored repeat
      04h = Pulse

Mapping function values:

      00h = U
      01h = U^2
      02h = V
      03h = V^2
      04h = (U + V) / 2
      05h = (U^2 + V^2) / 2
      06h = sqrt(U^2 + V^2)
      07h = Minimum
      08h = Maximum
      09h = Rmax

104012A4h - PICA(00A9h) - GPUREG_TEXUNIT3_PROCTEX1 (R/W)

      0-15   fixed1.3.12, U-direction noise amplitude
      16-31  float1.5.10, U-direction noise phase

Configures the procedural texture unit's U-direction noise amplitude/phase.
104012A8h - PICA(00AAh) - GPUREG_TEXUNIT3_PROCTEX2 (R/W)

      0-15   fixed1.3.12, V-direction noise amplitude
      16-31  float1.5.10, V-direction noise phase

Configures the procedural texture unit's V-direction noise amplitude/phase.
104012ACh - PICA(00ABh) - GPUREG_TEXUNIT3_PROCTEX3 (R/W)

      0-15   float1.5.10, U-direction noise frequency
      16-31  float1.5.10, V-direction noise frequency

Configure the procedural texture unit's U-direction and V-direction noise frequency.
104012B0h - PICA(00ACh) - GPUREG_TEXUNIT3_PROCTEX4 (R/W)

      0-2    Minification filter (see below)
      3-6    Min Level of Detail (Min LOD) (usually 0)
      7-10   Max Level of Detail (Max LOD) (usually 6)
      11-18  Texture width (unsigned, 00h..FFh)
      19-26  Texture bias (upper 8bit of float1.5.10) (lower 8bit are in PROCTEX0)

Minification filter values:

      00h = Nearest
      01h = Linear
      02h = Nearest, Mipmap Nearest
      03h = Linear, Mipmap Nearest
      04h = Nearest, Mipmap Linear
      05h = Linear, Mipmap Linear

104012B4h - PICA(00ADh) - GPUREG_TEXUNIT3_PROCTEX5_LOW (R/W)
104012B8h - PICA(00AEh) - GPUREG_TEXUNIT3_PROCTEX5_HIGH (R/W)

      0-7    Mipmap level 0 base level (usually 00h) (Texture offset)
      8-15   Mipmap level 1 offset     (usually 80h)
      16-23  Mipmap level 2 offset     (usually C0h)
      24-31  Mipmap level 3 offset     (usually E0h)
      32-39  Mipmap level 4 offset     (usually F0h)
      40-47  Mipmap level 5 offset     (usually F8h)
      48-55  Mipmap level 6 offset     (usually FCh)
      56-63  Mipmap level 7 offset     (usually FEh)

Usually set to LOW=E0C08000h, HIGH=FEFCF8F0h.
"Sets the procedural texture unit's offset."
104012BCh - PICA(00AFh) - GPUREG_PROCTEX_LUT_INDEX (R/W)

      0-7    Index           (0..255 or 0..127, depending on selected table)
      8-11   Reference table (0=Noise, 1=?, 2=RGB, 3=Alpha, 4=Color, 5=ColorDiff)

Selects look-up table and index for writing via GPUREG_PROCTEX_LUT_DATA(i).
104012C0h+i*4 - PICA(00B0h+i) - GPUREG_PROCTEX_LUT_DATA(0..7) (R/W)

      0-31   LUT data

These registers behave as a FIFO queue. Each write to these registers writes the provided value to the table selected with GPUREG_PROCTEX_LUT, starting at the selected index.
Noise Table (128 elements):

      0-11   fixed0.0.12, Value
      12-23  fixed0.0.12 with two's complement
               ( [0.5,1.0) mapped to [-1.0,0) ), Difference from next element

RGB Mapping Function Table (128 elements):

      0-11   fixed0.0.12, Value
      12-23  fixed0.0.12 with two's complement, Difference from next element

Alpha Mapping Function Table (128 elements):

      0-11   fixed0.0.12, Value
      12-23  fixed0.0.12 with two's complement, Difference from next element

Color Table (256 elements):

      0-7    Red           (unsigned, 00h..FFh)
      8-15   Green         (unsigned, 00h..FFh)
      16-23  Blue          (unsigned, 00h..FFh)
      24-31  Alpha         (unsigned, 00h..FFh)

Color Difference Table (256 elements):

      0-7    Half of red   (signed, -80h..+7Fh) ;\
      8-15   Half of green (signed, -80h..+7Fh) ; difference between current
      16-23  Half of blue  (signed, -80h..+7Fh) ; and next color table elements
      24-31  Half of alpha (signed, -80h..+7Fh) ;/

     ____________________ Procedural Texture Generation Notes _____________________

Overview
Procedural texture generation has four stages:

      Noise Module (outputs u',v')
      Repeat Module (outputs u'',v'')
      Base Shape (also notated as G(u'',v''), output g)
      F(g) and Lookup Table

Noise Module
This stage applies noise on the input coordinates. Little is known about this other than that there are three noise parameters: Amplitude, Frequency, and Phase.
Repeat Module
This stage performs basic texture coordinate wrapping on the noised coordinates. It supports symmetric and mirrored wrapping. They don't seem to be configurable beyond that.
Base Shape
The U'' and V'' coordinates are used to generate a scalar value in the range [0;1] from the wrapped coordinates using one of six functions.
The output of this function is named "g".
F(g) and Lookup Table
F is a selectable function which transforms g to another scalar value. There are two known options for F:

      the identity function
      a triangle function

The final texel color is determined by using the value of F(g) as an index into a configurable lookup table.

3DS GPU Internal Registers - Texturing registers (Environment)

Below are "texture env(ironment?)" registers for "texture combiner's". Unknown what that means, probably something for merging output from texture units 0,1,2. But unknown why there are six TexEnv's.
10401300h - PICA(00C0h) - GPUREG_TEXENV0_SOURCE (R/W)
10401320h - PICA(00C8h) - GPUREG_TEXENV1_SOURCE (R/W)
10401340h - PICA(00D0h) - GPUREG_TEXENV2_SOURCE (R/W)
10401360h - PICA(00D8h) - GPUREG_TEXENV3_SOURCE (R/W)
104013C0h - PICA(00F0h) - GPUREG_TEXENV4_SOURCE (R/W)
104013E0h - PICA(00F8h) - GPUREG_TEXENV5_SOURCE (R/W)

      0-3    RGB source 0
      4-7    RGB source 1
      8-11   RGB source 2
      16-19  Alpha source 0
      20-23  Alpha source 1
      24-27  Alpha source 2

Configures a texture combiner's sources.
Source values:

      00h = Primary color
      01h = Fragment primary color
      02h = Fragment secondary color
      03h = Texture 0
      04h = Texture 1
      05h = Texture 2
      06h = Texture 3
      0xh = ?
      0Dh = Previous buffer
      0Eh = Constant (from GPUREG_TEXENVi_COLOR)
      0Fh = Previous

10401304h - PICA(00C1h) - GPUREG_TEXENV0_OPERAND (R/W)
10401324h - PICA(00C9h) - GPUREG_TEXENV1_OPERAND (R/W)
10401344h - PICA(00D1h) - GPUREG_TEXENV2_OPERAND (R/W)
10401364h - PICA(00D9h) - GPUREG_TEXENV3_OPERAND (R/W)
104013C4h - PICA(00F1h) - GPUREG_TEXENV4_OPERAND (R/W)
104013E4h - PICA(00F9h) - GPUREG_TEXENV5_OPERAND (R/W)
"Configures a texture combiner's operands."
uh, R/W mask is only 00111333h...?

      0-3    RGB operand 0    (0..0Dh, see below)     ;\uh, but R/W mask suggest
      4-7    RGB operand 1    (0..0Dh, see below)     ; range 0..3 only
      8-11   RGB operand 2    (0..0Dh, see below)     ;/
      12-14  Alpha operand 0  (0..7, see below)       ;\uh, but R/W mask suggest
      16-18  Alpha operand 1  (0..7, see below)       ; range 0..1 only
      20-22  Alpha operand 2  (0..7, see below)       ;/

RGB operand values:

      00h = Source color
      01h = One minus source color
      02h = Source alpha
      03h = One minus source alpha
      04h = Source red                    ;\
      05h = One minus source red          ;
      08h = Source green                  ; uh, really? R/W mask is only 2bit
      09h = One minus source green        ;
      0Ch = Source blue                   ;
      0Dh = One minus source blue         ;/

Alpha operand values:

      0h  = Source alpha
      1h  = One minus source alpha
      2h  = Source red                    ;\
      3h  = One minus source red          ;
      4h  = Source green                  ; uh, really? R/W mask is only 1bit
      5h  = One minus source green        ;
      6h  = Source blue                   ;
      7h  = One minus source blue         ;/

10401308h - PICA(00C2h) - GPUREG_TEXENV0_COMBINER (R/W)
10401328h - PICA(00CAh) - GPUREG_TEXENV1_COMBINER (R/W)
10401348h - PICA(00D2h) - GPUREG_TEXENV2_COMBINER (R/W)
10401368h - PICA(00DAh) - GPUREG_TEXENV3_COMBINER (R/W)
104013C8h - PICA(00F2h) - GPUREG_TEXENV4_COMBINER (R/W)
104013E8h - PICA(00FAh) - GPUREG_TEXENV5_COMBINER (R/W)

      0-3    RGB combine mode   (0..9, see below)
      16-19  Alpha combine mode (0..9, see below)

Combine mode values:

      0h = Replace
      1h = Modulate
      2h = Add
      3h = Add signed
      4h = Interpolate
      5h = Subtract
      6h = Dot3 RGB
      7h = Dot3 RGBA
      8h = Multiply then add
      9h = Add then multiply
      Ah..Fh = ?

1040130Ch - PICA(00C3h) - GPUREG_TEXENV0_COLOR (R/W)
1040132Ch - PICA(00CBh) - GPUREG_TEXENV1_COLOR (R/W)
1040134Ch - PICA(00D3h) - GPUREG_TEXENV2_COLOR (R/W)
1040136Ch - PICA(00DBh) - GPUREG_TEXENV3_COLOR (R/W)
104013CCh - PICA(00F3h) - GPUREG_TEXENV4_COLOR (R/W)
104013ECh - PICA(00FBh) - GPUREG_TEXENV5_COLOR (R/W)

      0-7    Constant color Red    (unsigned, 00h..FFh)
      8-15   Constant color Green  (unsigned, 00h..FFh)
      16-23  Constant color Blue   (unsigned, 00h..FFh)
      24-31  Constant color Alpha  (unsigned, 00h..FFh)

10401310h - PICA(00C4h) - GPUREG_TEXENV0_SCALE (R/W)
10401330h - PICA(00CCh) - GPUREG_TEXENV1_SCALE (R/W)
10401350h - PICA(00D4h) - GPUREG_TEXENV2_SCALE (R/W)
10401370h - PICA(00DCh) - GPUREG_TEXENV3_SCALE (R/W)
104013D0h - PICA(00F4h) - GPUREG_TEXENV4_SCALE (R/W)
104013F0h - PICA(00FCh) - GPUREG_TEXENV5_SCALE (R/W)

      0-1    RGB scale      (0=1x, 1=2x, 2=4x, 3=?)
      16-17  Alpha scale    (0=1x, 1=2x, 2=4x, 3=?)

1040131Ch - PICA(00C7h) - GPUREG_undoc_1040131Ch (R/W=00000007h)

      0-2    UNKNOWN (0..7) (R/W)

10401380h - PICA(00E0h) - GPUREG_TEXENV_UPDATE_BUFFER (R/W)

      0-2    Fog mode                     (0=Disabled, 5=Fog, 7=Gas, other=?)
      3      Shading density source       (0=Plain density, 1=Depth density)
      8      TexEnv 1 RGB buffer input    (0=Previous Buffer, 1=Previous)
      9      TexEnv 2 RGB buffer input    (0=Previous Buffer, 1=Previous)
      10     TexEnv 3 RGB buffer input    (0=Previous Buffer, 1=Previous)
      11     TexEnv 4 RGB buffer input    (0=Previous Buffer, 1=Previous)
      12     TexEnv 1 Alpha buffer input  (0=Previous Buffer, 1=Previous)
      13     TexEnv 2 Alpha buffer input  (0=Previous Buffer, 1=Previous)
      14     TexEnv 3 Alpha buffer input  (0=Previous Buffer, 1=Previous)
      15     TexEnv 4 Alpha buffer input  (0=Previous Buffer, 1=Previous)
      16     Z flip                       (0=Don't flip,1=Flip)
      24-25  UNKNOWN "0x0" (R/W)

This register is shared between the gas/fog mode configuration and texture combiner buffer inputs. Texture combiner buffer inputs are typically written with a mask of 0x2, and the gas/fog mode configuration is typically written with a mask of 0x5.
10401384h - PICA(00E1h) - GPUREG_FOG_COLOR (R/W)

      0-7    Fog color Red    (unsigned, 00h..FFh)
      8-15   Fog color Green  (unsigned, 00h..FFh)
      16-23  Fog color Blue   (unsigned, 00h..FFh)

10401388h - PICA(00E2h) - GPUREG_undoc_10401388h (R/W=0000FFFFh)
1040138Ch - PICA(00E3h) - GPUREG_undoc_1040138Ch (R/W=0000FFFFh)

      0-15   UNKNOWN (0..FFFFh) (R/W)

10401390h - PICA(00E4h) - GPUREG_GAS_ATTENUATION (R/W)

      0-15   float1.5.10, Gas density attenuation

10401394h - PICA(00E5h) - GPUREG_GAS_ACCMAX (R/W)

      0-15   float1.5.10, Gas maximum density accumulation

10401398h - PICA(00E6h) - GPUREG_FOG_LUT_INDEX (R/W)

      0-6    Index for FOG_LUT_DATA (0..7Fh)

The index is incremented on FOG_LUT_DATA writes (but not incremented on reads).
104013A0h+i*4 - PICA(00E8h+i) - GPUREG_FOG_LUT_DATA(0..7) (R/W)

      0-12   fixed1.1.11, Difference from next entry
      13-23  fixed0.0.11, Value

These registers behave as a FIFO queue. Each write to these registers writes the provided value to the fog look-up table, starting at the index selected with GPUREG_FOG_LUT_INDEX.
104013F4h - PICA(00FDh) - GPUREG_TEXENV_BUFFER_COLOR (R/W)

      0-7    Texture combiner buffer color Red    (unsigned, 00h..FFh)
      8-15   Texture combiner buffer color Green  (unsigned, 00h..FFh)
      16-23  Texture combiner buffer color Blue   (unsigned, 00h..FFh)
      24-31  Texture combiner buffer color Alpha  (unsigned, 00h..FFh)

3DS GPU Internal Registers - Fragment Lighting registers

10401500h+i*40h - PICA(0140h+10h*(0..7)) - GPUREG_LIGHTi_SPECULAR0 (R/W)
10401504h+i*40h - PICA(0141h+10h*(0..7)) - GPUREG_LIGHTi_SPECULAR1 (R/W)
10401508h+i*40h - PICA(0142h+10h*(0..7)) - GPUREG_LIGHTi_DIFFUSE (R/W)
1040150Ch+i*40h - PICA(0143h+10h*(0..7)) - GPUREG_LIGHTi_AMBIENT (R/W)
10401700h - PICA(01C0h) - GPUREG_LIGHTING_AMBIENT (R/W)

      0-7    unsigned, Blue
      8-9    UNKNOWN (maybe Blue MSBs? if so, is it really unsigned?) (R/W)
      10-17  unsigned, Green
      18-19  UNKNOWN (R/W)
      20-27  unsigned, Red
      28-29  UNKNOWN (R/W)

These registers contain the colors of the corresponding lights, usually set to following values:

      GPUREG_LIGHTi_SPECULAR0 = material_specular0*lightX_specular0
      GPUREG_LIGHTi_SPECULAR1 = material_specular1*lightX_specular1
      GPUREG_LIGHTi_DIFFUSE   = material_diffuse*lightX_diffuse
      GPUREG_LIGHTi_AMBIENT   = material_ambient*lightX_ambient
      GPUREG_LIGHTING_AMBIENT = material_ambient*scene_ambient + material_emission

10401510h+i*40h - PICA(0144h+10h*(0..7)) - GPUREG_LIGHTi_VECTOR_LOW (R/W)
10401514h+i*40h - PICA(0145h+10h*(0..7)) - GPUREG_LIGHTi_VECTOR_HIGH (R/W)

      0-15   float1.5.10, X coordinate
      16-31  float1.5.10, Y coordinate
      32-47  float1.5.10, Z coordinate

Light position (for a positional light) or the light direction vector (for a directional light) of the corresponding light.
Uh, does the direction vector need to be normalized? And how does it differ from SPOTDIR direction vector?
10401518h+i*40h - PICA(0146h+10h*(0..7)) - GPUREG_LIGHTi_SPOTDIR_LOW (R/W)
1040151Ch+i*40h - PICA(0147h+10h*(0..7)) - GPUREG_LIGHTi_SPOTDIR_HIGH (R/W)

      0-12   fixed1.1.11, X coordinate (negated)
      16-28  fixed1.1.11, Y coordinate (negated)
      32-44  fixed1.1.11, Z coordinate (negated)

Spot direction (unitary) vector of the corresponding light.
10401524h+i*40h - PICA(0149h+10h*(0..7)) - GPUREG_LIGHTi_CONFIG (R/W)

      0      Light type             (0=Positional light, 1=Directional light)
      1      Two side diffuse       (0=One side, 1=Both sides)
      2      Use geometric factor 0 (0=Don't use, 1=Use)
      3      Use geometric factor 1 (0=Don't use, 1=Use)

Configures a light's properties.
10401528h+i*40h - PICA(014Ah+10h*(0..7)) - GPUREG_LIGHTi_ATTENUATION_BIAS
1040152Ch+i*40h - PICA(014Bh+10h*(0..7)) - GPUREG_LIGHTi_ATTENUATION_SCALE

      0-19   float1.7.12, Distance attenuation value    (R/W)

For the odd 20bit floating point format, one could do:

      (float24)/10h                ;convert float1.7.16 to float1.7.12

Distance attenuation BIAS and SCALE values of the corresponding light.
The attenuation factor is DA(clip(BIAS + SCALE*distance, 0.0, 1.0)).

     _______________________

1040123Ch - PICA(008Fh) - GPUREG_LIGHTING_ENABLE (R/W)

      0      Enable Lighting  (0=Disable, 1=Enable)

Uh, that is in texture register area... is that texture specific?
10401718h - PICA(01C6h) - GPUREG_LIGHTING_DISABLE (R/W)

      0      Disable (0=Enable, 1=Disable)

10401708h - PICA(01C2h) - GPUREG_LIGHTING_NUM_LIGHTS (R/W)

      0-2    Number of active lights - 1    (0..7 = 1..8 Lights)

To use 0 lights, one seems to have to disable lighting... unknown if one can keep GPUREG_LIGHTING_AMBIENT enabled in that state.
1040170Ch - PICA(01C3h) - GPUREG_LIGHTING_CONFIG0 (R/W)

      0      Shadow factor enable  (0=Disable, 1=Enable)
               (usually accompanied by bit 16, 17, or 18)
      2-3    Fresnel selector (0=None, 1=Primary, 2=Secondary, 3=Both alpha's)
      4-7    Light environment configuration (see below)
      8-11   UNKNOWN "0x4" (R/W)
      16     Apply shadow attenuation to primary color   (0=Don't apply, 1=Apply)
      17     Apply shadow attenuation to secondary color (0=Don't apply, 1=Apply)
      18     Invert shadow attenuation                 (0=Don't invert, 1=Invert)
      19     Apply shadow attenuation to alpha component (0=Don't apply, 1=Apply)
      20-21  UNKNOWN (R/W)
      22-23  Bump map texture unit
      24-25  Shadow map texture unit
      26     UNKNOWN (R/W)
      27     Clamp highlights         (0=Disable, 1=Enable)
      28-29  Bump mode (0=Not used, 1=Use as bump map, 2=Use as tangent map)
      30     Recalculate bump vectors (0=Enable, 1=Disable)
               (usually set to 1 when bump mode is not 0)
      31     UNKNOWN "0x1" (R/W)

Fresnel selector values:

      0h = None
      1h = Primary alpha
      2h = Secondary alpha
      3h = Primary and secondary alpha

Light environment configuration values:

      Value Description       Available LUTs
      00h = Configuration 0   D0, RR, SP, DA
      01h = Configuration 1   FR, RR, SP, DA
      02h = Configuration 2   D0, D1, RR, DA
      03h = Configuration 3   D0, D1, FR, DA
      04h = Configuration 4   All except for FR
      05h = Configuration 5   All except for D1
      06h = Configuration 6   All except for RB and RG
      08h = Configuration 7   All

The light environment configuration controls which LUTs are available for use. If a LUT is not available in the selected configuration, its value will always read a constant 1.0 regardless of the enable state in GPUREG_LIGHTING_CONFIG1. If RR is enabled but not RG or RB, the output of RR is used for the three components; Red, Green and Blue.
10401710h - PICA(01C4h) - GPUREG_LIGHTING_CONFIG1 (R/W)

      0-7   Fragment light source 0-7 shadows              (0=Enable, 1=Disable)
      8-15  Fragment light source 0-7 spot light           (0=Enable, 1=Disable)
      16    Term 0 distribution component D0 LUT           (0=Enable, 1=Disable)
      17    Term 1 distribution component D1 LUT           (0=Enable, 1=Disable)
      18    0x1                                            (1)
      19    Fresnel FR LUT disabled                        (0=Enable, 1=Disable)
      20    Term 1 reflection component RB LUT             (0=Enable, 1=Disable)
      21    Term 1 reflection component RG LUT             (0=Enable, 1=Disable)
      22    Term 1 reflection component RR LUT             (0=Enable, 1=Disable)
      24-31 Fragment light source 0-7 distance attenuation (0=Enable, 1=Disable)

Allows to disable various aspects of the light environment.
10401714h - PICA(01C5h) - GPUREG_LIGHTING_LUT_INDEX (R/W)

      0-7   Starting index       (00h..FFh)    ;\for reading/writing via
      8-12  Look-up table number (see below)   ;/GPUREG_LIGHTING_LUT_DATA(i)

Lookup table numbers:

      00h     = D0      ;\Distribution, whatever that is?
      01h     = D1      ;/
      03h     = FR      ;-Fresnel, whatever that is?
      04h     = RB      ;\
      05h     = RG      ; Reflection with separate blue/green/red tables?
      06h     = RR      ;/
      08h-0Fh = SP0-7   ;-Spotlight?             ;\maybe for light 0..7 ?
      10h-17h = DA0-7   ;-Distance attenuation?  ;/

Note: The index in bit0-7 is auto-incremented when writing (or reading) LUT_DATA registers; there is no carry-out to table number in bit8-12.
10401720h+i*4 - PICA(01C8h+i) - GPUREG_LIGHTING_LUT_DATA(0..7) (R/W)

      0-11   fixed0.0.12, Entry value
      12-23  fixed1.0.11, Absolute value of the difference between the next
               entry and this entry, used to implement linear interpolation
               uh, how/why is that a ABSOLUTE value WITH SIGN bit?

A LUT contains data for the input domain [-1.0, 1.0], which is indexed using a signed 8bit number [-128, 127]. Therefore a LUT contains 256 entries. The index of a value is (int)(x/127.0f) & 0xFF.
DA: The input domain is [0.0, 1.0], and the index is an unsigned 8bit number [0, 255] instead.
10401740h - PICA(01D0h) - GPUREG_LIGHTING_LUTINPUT_ABS (R/W)

      0      UNKNOWN (R/W)
      1      abs() flag for the input of D0 (0=Enable, 1=Disable)
      4      UNKNOWN (R/W)
      5      abs() flag for the input of D1 (0=Enable, 1=Disable)
      8      UNKNOWN (R/W)
      9      abs() flag for the input of SP (0=Enable, 1=Disable)
      12     UNKNOWN (R/W)
      13     abs() flag for the input of FR (0=Enable, 1=Disable)
      16     UNKNOWN (R/W)
      17     abs() flag for the input of RB (0=Enable, 1=Disable)
      20     UNKNOWN (R/W)
      21     abs() flag for the input of RG (0=Enable, 1=Disable)
      24     UNKNOWN (R/W)
      25     abs() flag for the input of RR (0=Enable, 1=Disable)

Controls whether the absolute value of the input is taken before using a LUT.
10401744h - PICA(01D1h) - GPUREG_LIGHTING_LUTINPUT_SELECT (R/W)

      0-2    Input selector for D0  ;\Input selector values:
      4-6    Input selector for D1  ;  0h = N . H   ;uh, dot symbol?
      8-10   Input selector for SP  ;  1h = V . H   ; ... maybe multiply?
      12-14  Input selector for FR  ;  2h = N . V   ;uh, who is N,H,L,V,P
      16-18  Input selector for RB  ;  3h = L . N   ; and greek symbol?
      20-22  Input selector for RG  ;  4h = -L . P (aka Spotlight aka SP)
      24-26  Input selector for RR  ;/ 5h = cos <greek symbol> (aka CP)

Selects the input from LUTs.

      N = Normal Vector?
      V = View Vector?
      L = Light Vector?
      H = ?
      P = ?
      cos <greek symbol> = ?

10401748h - PICA(01D2h) - GPUREG_LIGHTING_LUTINPUT_SCALE (R/W)

      0-2    Scaler selector for D0    ;\Scaler selector values:
      4-6    Scaler selector for D1    ;  0h = 1x
      8-10   Scaler selector for SP    ;  1h = 2x
      12-14  Scaler selector for FR    ;  2h = 4x
      16-18  Scaler selector for RB    ;  3h = 8x
      20-22  Scaler selector for RG    ;  6h = 0.25x
      24-26  Scaler selector for RR    ;/ 7h = 0.5x
      28-30  UNKNOWN (R/W)

Controls the scaling that is applied to the output of a LUT.
1040174Ch - PICA(01D3h) - GPUREG_undoc_1040174Ch (R/W=00000001h)

      0      UNKNOWN (0..1) (R/W)

10401750h - PICA(01D4h) - GPUREG_undoc_10401750h (R/W=0FFFFF03h)

      0-1    UNKNOWN (0..3) (R/W)
      8-31   UNKNOWN (0..FFFFFFh) (R/W)

10401754h - PICA(01D5h) - GPUREG_undoc_10401754h (R/W=1FFF1FFFh)
10401758h - PICA(01D6h) - GPUREG_undoc_10401758h (R/W=1FFF1FFFh)

      0-12   UNKNOWN (0..1FFFh) (R/W)
      16-28  UNKNOWN (0..1FFFh) (R/W)

1040175Ch - PICA(01D7h) - GPUREG_undoc_1040175Ch (R/W=000FFFFFh)
10401760h - PICA(01D8h) - GPUREG_undoc_10401760h (R/W=000FFFFFh)

      0-19   UNKNOWN (0..FFFFFh) (R/W)

10401764h - PICA(01D9h) - GPUREG_LIGHTING_LIGHT_PERMUTATION (R/W)

      0-2    ID of the 1st enabled light (0..7)
      4-6    ID of the 2nd enabled light (0..7)
      8-10   ID of the 3rd enabled light (0..7)
      12-14  ID of the 4th enabled light (0..7)
      16-18  ID of the 5th enabled light (0..7)
      20-22  ID of the 6th enabled light (0..7)
      24-26  ID of the 7th enabled light (0..7)
      28-30  ID of the 8th enabled light (0..7)

Sets the IDs of enabled light sources (1st..8th light does refer to the number of lights in GPUREG_LIGHTING_NUM_LIGHTS).
Uh, LIGHT_PERMUTATION is a scary homebrew slang for LIGHT_IDs?

3DS GPU Internal Registers - Unknown/Unused/Undocumented Registers

Unused Registers that Mirror to GPUREG_RESTART_PRIMITIVE (R/W)

      104011C0h 40h  ;PICA(0070h..007Fh) mirrors to GPUREG_RESTART_PRIMITIVE
      104013F8h 08h  ;PICA(00FEh..00FFh) mirrors to GPUREG_RESTART_PRIMITIVE
      1040149Ch 24h  ;PICA(0127h..012Fh) mirrors to GPUREG_RESTART_PRIMITIVE
      10401780h 80h  ;PICA(01E0h..01FFh) mirrors to GPUREG_RESTART_PRIMITIVE
      10401900h 08h  ;PICA(0240h..0241h) mirrors to GPUREG_RESTART_PRIMITIVE
      10401918h 10h  ;PICA(0246h..0249h) mirrors to GPUREG_RESTART_PRIMITIVE
      1040192Ch 14h  ;PICA(024Bh..024Fh) mirrors to GPUREG_RESTART_PRIMITIVE
      10401960h 18h  ;PICA(0258h..025Dh) mirrors to GPUREG_RESTART_PRIMITIVE
      10401980h 80h  ;PICA(0260h..027Fh) mirrors to GPUREG_RESTART_PRIMITIVE
      10401D00h 300h ;PICA(0340h..03FFh) mirrors to GPUREG_RESTART_PRIMITIVE

The mirrors (and GPUREG_RESTART_PRIMITIVE itself) are R/W, however, writing doesn't always work for some reason, or the write is applied only after issuing another three writes or so?
Unused or Write-Only Registers that return Garbage/Mirrors when reading
104018BCh..104018DCh and 104018F0h..104018FCh do return mirrors of multiple other registers ORed together.

      104018BCh = 1040183Ch,1040189Ch,104018B4h           ;ATTR_BUF_DRAWELEMENTS
      104018C0h = 10401840h,104018E0h,10401880h           ;unused (or write-only?)
      104018C4h = 10401844h,104018E4h,10401884h           ;VTX_FUNC
      104018C8h = 10401848h,104018E8h,10401888h           ;FIXEDATTRIB_INDEX
      104018CCh = 1040184Ch,104018ECh,1040188Ch,1040189Ch ;FIXEDATTRIB_DATA0
      104018D0h = 10401850h,104018E0h,10401890h           ;FIXEDATTRIB_DATA1
      104018D4h = 10401854h,104018E4h,10401894h           ;FIXEDATTRIB_DATA2
      104018D8h = 10401858h,104018E8h,10401898h           ;unused (or write-only?)
      104018DCh = 1040185Ch,104018ECh                     ;unused (or write-only?)
      104018F0h = 10401870h,104018E0h                     ;GPUREG_CMDBUF_JUMP0
      104018F4h = 10401874h,104018E4h,104018B4h           ;GPUREG_CMDBUF_JUMP1
      104018F8h = 10401878h,104018E8h                     ;unused (or write-only?)
      104018FCh = 1040187Ch,104018ECh,104018B4h,1040189Ch ;unused (or write-only?)

10401940h, 10401958h, 1040195Ch seem to mirror to single registers without ORing multiple values.

      10401940h = 10401944h (GPUREG_VSH_OUTMAP_TOTAL2)    ;unused (or write-only?)
      10401958h = 10401950h (GPUREG_GSH_MISC1)            ;unused (or write-only?)
      1040195Ch = 1040194Ch (GPUREG_GEOSTAGE_CONFIG2)     ;unused (or write-only?)

Unused or Write-Only Registers that return Zero when reading

      1040118Ch = zero                                    ;EARLYDEPTH_CLEAR
      10401440h = zero                                    ;RENDERBUFFER_INVALIDATE
      10401444h = zero                                    ;RENDERBUFFER_FLUSH
      1040148Ch = zero                                    ;GAS_LUT_INDEX
      104018B8h = zero                                    ;ATTR_BUF_DRAWARRAYS
      10401A14h/10401AD4h/10401B94h/10401C54h     = zero  ;unused (or write-only?)
      10401A18h/10401AD8h/10401B98h/10401C58h     = zero  ;unused (or write-only?)
      10401A1Ch/10401ADCh/10401B9Ch/10401C5Ch     = zero  ;unused (or write-only?)
      10401A20h/10401AE0h/10401BA0h/10401C60h     = zero  ;unused (or write-only?)
      10401A38h/10401AF8h/10401BB8h/10401C78h     = zero  ;unused (or write-only?)
      10401A3Ch/10401AFCh/10401BBCh/10401C7Ch     = zero  ;CODETRANSFER_END
      10401A40h/10401B00h/10401BC0h/10401C80h     = zero  ;FLOATUNIFORM_INDEX
      10401A44h/10401B04h/10401BC4h/10401C84h+i*4 = zero  ;FLOATUNIFORM_DATA0-7
      10401A64h/10401B24h/10401BE4h/10401CA4h     = zero  ;unused (or write-only?)
      10401A68h/10401B28h/10401BE8h/10401CA8h     = zero  ;unused (or write-only?)
      10401A6Ch/10401B2Ch/10401BECh/10401CACh     = zero  ;CODETRANSFER_INDEX
      10401A70h/10401B30h/10401BF0h/10401CB0h+i*4 = zero  ;CODETRANSFER_DATA0-7
      10401A90h/10401B50h/10401B10h/10401CD0h     = zero  ;unused (or write-only?)
      10401A94h/10401B54h/10401C14h/10401CD4h     = zero  ;OPDESCS_INDEX
      10401A98h/10401B58h/10401C18h/10401CD8h+i*4 = zero  ;OPDESCS_DATA0..7
      10401AB8h/10401B78h/10401C38h/10401CF8h     = zero  ;unused (or write-only?)
      10401ABCh/10401B7Ch/10401C3Ch/10401CFCh     = zero  ;unused (or write-only?)

Unused Registers that return Zero when reading
These registers aren't R/W, and they seem to be always zero (though some might be undocumented read-only or write-only registers).

      104010D8h 28h  ;PICA(N/A)          unused (0)            ;-Finalize
      1040115Ch 4    ;PICA(0057h)        unused (0)
      10401174h 0Ch  ;PICA(005Dh..005Fh) unused (0)
      10401240h 4    ;PICA(0090h)        unused (0)   ;XXX used, write-only?
      1040125Ch 4    ;PICA(0097h)        unused (0)   ;XXX used, write-only?
      10401260h 4    ;PICA(0098h)        unused (0)   ;XXX used, write-only?
      1040127Ch 24h  ;PICA(009Fh..00A7h) unused (0)
      104012E0h 20h  ;PICA(00B8h..00BFh) unused (0)
      10401314h 08h  ;PICA(00C5h..00C6h) unused (0)            ;-TexEnv0
      10401334h 0Ch  ;PICA(00CDh..00CFh) unused (0)            ;-TexEnv1
      10401354h 0Ch  ;PICA(00D5h..00D7h) unused (0)            ;-TexEnv2
      10401374h 0Ch  ;PICA(00DDh..00DFh) unused (0)            ;-TexEnv3
      1040139Ch 4    ;PICA(00E7h)        unused (0)
      104013D4h 0Ch  ;PICA(00F5h..00F7h) unused (0)            ;-TexEnv4
      10401420h 14h  ;PICA(0108h..010Ch) unused (0)
      104014C4h 38h  ;PICA(0131h..013Eh) unused (0)
      10401520h 4    ;PICA(0148h)        unused (0)            ;\LIGHT0
      10401530h 10h  ;PICA(014Ch..014Fh) unused (0)            ;/
      10401560h 4    ;PICA(0158h)        unused (0)            ;\LIGHT1
      10401570h 10h  ;PICA(015Ch..015Fh) unused (0)            ;/
      104015A0h 4    ;PICA(0168h)        unused (0)            ;\LIGHT2
      104015B0h 10h  ;PICA(016Ch..016Fh) unused (0)            ;/
      104015E0h 4    ;PICA(0178h)        unused (0)            ;\LIGHT3
      104015F0h 10h  ;PICA(017Ch..017Fh) unused (0)            ;/
      10401620h 4    ;PICA(0188h)        unused (0)            ;\LIGHT4
      10401630h 10h  ;PICA(018Ch..018Fh) unused (0)            ;/
      10401660h 4    ;PICA(0198h)        unused (0)            ;\LIGHT5
      10401670h 10h  ;PICA(019Ch..019Fh) unused (0)            ;/
      104016A0h 4    ;PICA(01A8h)        unused (0)            ;\LIGHT6
      104016B0h 10h  ;PICA(01ACh..01AFh) unused (0)            ;/
      104016E0h 4    ;PICA(01B8h)        unused (0)            ;\LIGHT7
      104016F0h 10h  ;PICA(01BCh..01BFh) unused (0)            ;/
      10401704h 4    ;PICA(01C1h)        unused (0)            ;\
      1040171Ch 4    ;PICA(01C7h)        unused (0)            ; LIGHTING
      10401768h 18h  ;PICA(01DAh..01DFh) unused (0)            ;/
      104018ACh 08h  ;PICA(022Bh..022Ch) unused (0)            ;-VERTEX

Unused command numbers PICA(0000h..000Fh, 0020h..003Fh)
Registers at 10401000h..1040103Fh and 10401080h..104010FFh are writeable by ARM11 only, not via PICA command numbers 0000h..000Fh, 0020h..003Fh.
Unused command numbers PICA(0400h..FFFFh)
The PICA command numbers in CMDBUF are said to be 16bit wide, however, values 0400h..FFFFh seem to be unused (and there are no I/O addresses for them; accessing 10402000h and up triggers data abort).

3DS GPU Shader Instruction Set - Opcode Summary

Shader Instruction Set Summary

      Opcode  Fmt  Name    Description
      00h     1    ADD     Add two vectors component by component
      01h     1    DP3     Dot product on two 3-component vectors
      02h     1    DP4     Dot product on two 4-component vectors
      03h     1    DPH     Dot product on a 3-component and a 4-component vector
      04h     1    DST     Equivalent to Microsoft's "dst" instruction
      05h     1u   EX2     Exponent with base 2 on 1st component of SRC1
      06h     1u   LG2     Logarithm with base 2 on 1st component of SRC1
      07h     1u   LITP    Related to Microsoft's "lit" instruction
      08h     1    MUL     Multiply two vectors component by component
      09h     1    SGE     Set output if SRC1>=SRC2
      0Ah     1    SLT     Set output if SRC1<SRC2
      0Bh     1u   FLR     Computes SRC1's floor component by component
      0Ch     1    MAX     Max of two vectors, component by component
      0Dh     1    MIN     Min of two vectors, component by component
      0Eh     1u   RCP     Reciprocal of vector's 1st component
      0Fh     1u   RSQ     Reciprocal of square root of vector's 1st component
      10h-11h ?    ?       ?
      12h     1u   MOVA    Move to address register (float to integer) (to "a0" ?)
      13h     1u   MOV     Move to register
      14h-17h ?    ?       ?
      18h     1i   DPHI    Dot product on a 3-component and a 4-component vector
      19h     1i   DSTI    DST with sources swapped
      1Ah     1i   SGEI    Set output if SRC1>=SRC2
      1Bh     1i   SLTI    Set output if SRC1<SRC2
      1Ch-1Fh ?    ?       ?
      20h     0    BREAK   Break out of LOOP block
      21h     0    NOP     No operation
      22h     0    END     Done (stop execution and set ready flag?)
      23h     2    BREAKC  Break (if condition is true)
      24h     2    CALL    Call (jump to DST, and return after NUM instructions)
      25h     2    CALLC   Call (as above, if condition is true)
      26h     3    CALLU   Call (as above, if BOOL is true)
      27h     3    IFU     Jump if/else BOOL is true
      28h     2    IFC     Jump if/else condition is true
      29h     3    LOOP    Loop start (repeat following opcodes)
      2Ah     0    EMIT    Geometry shader only: Emit vertex (or vertex+primitive)
      2Bh     4    SETEMIT Geometry shader only: Configure type/flags for EMIT
      2Ch     2    JMPC    Jump if condition is true
      2Dh     3    JMPU    Jump if BOOL is true
      2Eh-2Fh 1c   CMP     Compare X and Y components and Set booleans cmp.x/y
      30h-37h 5i   MADI    Multiply and Add vectors, component by component
      38h-3Fh 5    MAD     Multiply and Add vectors, component by component

Shader Opcode/Parameter Encoding Formats

      |..3 ..................2 ..................1 ..................0|
      |1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0| Fmt
      |_Opcode____|__0________________________________________________| 0  ;NoParam
      |_Opcode____|__Dst____|i1_|__Src1_______|__Src2___|______Desc___| 1  ;\
      |_Opcode____|__Dst____|i2_|__Src1___|______Src2___|______Desc___| 1i ; misc
      |_Opcode____|__Dst____|i1_|__Src1_______|__?______|______Desc___| 1u ;/
      |_Opcode__|CmpX_|CmpY_|i1_|__Src1_______|__Src2___|______Desc___| 1c CMP
      |_Opcode____|X|Y|Cnd|________DstOffs________|_?_|__NumInstr_____| 2  ;\JMP
      |_Opcode____|uID____|________DstOffs________|_?_|__NumInstr?____| 3  ;/etc.
      |_Opcode____|vID|P|W|__?________________________________________| 4  ;SETEMIT
      |_Opc_|__Dst____|i2_|__Src1___|__Src2_______|__Src3___|__Desc___| 5  ;MAD
      |_Opc_|__Dst____|i3_|__Src1___|__Src2___|______Src3___|__Desc___| 5i ;MADI

Shader Operand descriptors (OPDESC's)

      |..3 ..................2 ..................1 ..................0|
      |1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0|
      | |s0 |s1 |s2 |s3 |n|s0 |s1 |s2 |s3 |n|s0 |s1 |s2 |s3 |n|X_Y_Z_W|
         <---Source3-----> <---Source2-----> <---Source1-----> <-Dst->

3DS GPU Shader Instruction Set - Blurp

Overview
A compiled shader binary is comprised of two parts: the main instruction sequence and the operand descriptor table. These are both sent to the GPU around the same time but using separate GPU Commands. Instructions (such as format 1 instruction) may reference operand descriptors. When such is the case, the operand descriptor ID is the offset, in words, of the descriptor within the table. Both instructions and descriptors are coded in little endian. Basic implementations of the following specification can be found at [1] and [2]. The instruction set seems to have been heavily inspired by Microsoft's vs_3_0 [3] and the Direct3D shader code [4]. Please note that this page is being written as the instruction set is reverse engineered; as such it may very well contain mistakes.
Debug information found in the code.bin of "Ironfall: Invasion" suggests that there may not be more than 512 instructions and 128 operand descriptors in a shader.
Nomenclature

     - opcode names with I appended to them are the same as their non-I version,
         except they use the inverted instruction format, giving 7 bits to SRC2
         (and access to uniforms) and 5 bits to SRC1
     - opcode names with U appended to them are the same as their non-U version,
         except they are executed conditionally based on the value of a uniform
         boolean.
     - opcode names with C appended to them are the same as their non-C version,
         except they are executed conditionally based on a logical expression
         specified in the instruction.

Instruction formats

      Offset  Size (bits)     Description
     Format 1: (used for register operations)
      0x0  0-6    0x7     Operand descriptor ID (DESC)
      0x7  7-11   0x5     Source 2 register (SRC2)
      0xC  12-18  0x7     Source 1 register (SRC1)
      0x13 19-20  0x2     Address register index for SRC1 (IDX_1)
      0x15 21-25  0x5     Destination register (DST)
      0x1A 26-31  0x6     Opcode
     Format 1i: (used for register operations)
      0x0  0-6    0x7     Operand descriptor ID (DESC)
      0x7  7-13   0x7     Source 2 register (SRC2)
      0xE  14-18  0x5     Source 1 register (SRC1)
      0x13 19-20  0x2     Address register index for SRC2 (IDX_2)
      0x15 21-25  0x5     Destination register (DST)
      0x1A 26-31  0x6     Opcode
     Format 1u: (used for unary register operations)
      0x0  0-6    0x7     Operand descriptor ID (DESC)
       7   7-11     5     ?
      0xC  12-18  0x7     Source 1 register (SRC1)
      0x13 19-20  0x2     Address register index for SRC1 (IDX_1)
      0x15 21-25  0x5     Destination register (DST)
      0x1A 26-31  0x6     Opcode
     Format 1c: (used for comparison operations)
      0x0  0-6    0x7     Operand descriptor ID (DESC)
      0x7  7-11   0x5     Source 2 register (SRC2)
      0xC  12-18  0x7     Source 1 register (SRC1)
      0x13 19-20  0x2     Address register index for SRC1 (IDX_1)
      0x15 21-23  0x3     Comparison operator for Y (CMPY)
      0x18 24-26  0x3     Comparison operator for X (CMPX)
      0x1B 27-31  0x5     Opcode (5bit only)
     Format 2: (used for flow control instructions)
      0x0  0-7    0x8     Number of instructions (NUM)
        8  8-9    ?       ?
      0xA  10-21  0xC     Destination offset (in words) (DST)
      0x16 22-23  0x2     Condition boolean operator (CONDOP)
      0x18 24     0x1     Y reference bit (REFY)
      0x19 25     0x1     X reference bit (REFX)
      0x1A 26-31  0x6     Opcode
     Format 3: (used for uniform-based conditional flow control instructions)
      0x0  0-7    0x8     Number of instructions ? (NUM)
        8  8-9    ?       ?
      0xA  10-21  0xC     Destination offset (in words) (DST)
      0x16 22-25  0x4     Uniform ID (BOOL/INT)
      0x1A 26-31  0x6     Opcode
     Format 4: (used for SETEMIT)
        0  0-21   ?       ?
      0x16 22     0x1     Winding flag (FLAG_WINDING)
      0x17 23     0x1     Primitive emit flag (FLAG_PRIMEMIT)
      0x18 24-25  0x2     Vertex ID (VTXID)
      0x1A 26-31  0x6     Opcode
     Format 5: (used for MAD)
      0x0  0-4    0x5     Operand descriptor ID (DESC)
      0x5  5-9    0x5     Source 3 register (SRC3)
      0xA  10-16  0x7     Source 2 register (SRC2)
      0x11 17-21  0x5     Source 1 register (SRC1)
      0x16 22-23  0x2     Address register index for SRC2 (IDX_2)
      0x18 24-28  0x5     Destination register (DST)
      0x1D 29-31  0x3     Opcode (3bit only)
     Format 5i: (used for MADI)
      0x0  0-4    0x5     Operand descriptor ID (DESC)
      0x5  5-11   0x7     Source 3 register (SRC3)
      0xC  12-16  0x5     Source 2 register (SRC2)
      0x11 17-21  0x5     Source 1 register (SRC1)
      0x16 22-23  0x2     Address register index for SRC3 (IDX_3)
      0x18 24-28  0x5     Destination register (DST)
      0x1D 29-31  0x3     Opcode (3bit only)

Instructions
Unless noted otherwise, SRC1 and SRC2 refer to their respectively indexed float[4] registers (after swizzling). Similarly, DST refers to its indexed register modulo destination component masking, i.e. an expression like DST=SRC1 might actually just set DST.y to SRC1.y.

      Opcode  Format Name    Description
      00h     1      ADD     Adds two vectors component by component
                                   DST[i] = SRC1[i]+SRC2[i] for all i
      01h     1      DP3     Computes dot product on 3-component vectors
                                   DST = SRC1.SRC2
      02h     1      DP4     Computes dot product on 4-component vectors
                                   DST = SRC1.SRC2
      03h     1      DPH     Computes dot product on a 3-component vector
                             with 1.0 appended to it and a 4-component vector
                                   DST = SRC1.SRC2 (with SRC1 homogenous)
      04h     1      DST     Equivalent to Microsoft's dst instruction
                                   DST = {1, SRC1[1]*SRC2[1], SRC1[2], SRC2[3]}
      05h     1u     EX2     Computes SRC1's first component exponent with base 2
                                   DST[i] = EXP2(SRC1[0]) for all i
      06h     1u     LG2     Computes SRC1's first component logarithm with base 2
                                   DST[i] = LOG2(SRC1[0]) for all i
      07h     1u     LITP    Appears to be related to Microsoft's lit instruction
                                   DST = clamp(SRC1, min={0, -127.9961, 0, 0},
                                         max={inf, 127.9961, 0, inf})
                                   ;note: 127.9961 = 0x7FFF / 0x100
      08h     1      MUL     Multiplies two vectors component by component
                                   DST[i] = SRC1[i].SRC2[i] for all i
      09h     1      SGE     Sets output if SRC1 is greater than or equal to SRC2
                                   DST[i] = (SRC1[i] >= SRC2[i]) ? 1.0 : 0.0
                                   "for all i"    ;uh, who/what is "all i"?
      0Ah     1      SLT     Sets output if SRC1 is strictly less than SRC2
                                   DST[i] = (SRC1[i] < SRC2[i]) ? 1.0 : 0.0
                                   "for all i"
      0Bh     1u     FLR     Computes SRC1's floor component by component
                                   DST[i] = FLOOR(SRC1[i])
                                   "for all i"
      0Ch     1      MAX     Takes the max of two vectors, component by component
                                   DST[i] = MAX(SRC1[i], SRC2[i])
                                   "for all i"
      0Dh     1      MIN     Takes the min of two vectors, component by component
                                   DST[i] = MIN(SRC1[i], SRC2[i])
                                   "for all i"
      0Eh     1u     RCP     Computes the reciprocal of the vector's 1st component
                                   DST[i] = 1/SRC1[0]
                                   "for all i"
      0Fh     1u     RSQ     Computes the reciprocal of the square root of the
                             vector's first component;
                                   DST[i] = 1/sqrt(SRC1[0])
                                   "for all i"
      10h-11h ?      ???     ?
      12h     1u     MOVA    Move to address register; Casts the float uniform
                             given by SRC1 to an integer (truncating the fractional
                             part) and assigns the result to (a0.x, a0.y, _, _),
                             respecting the destination component mask.
      13h     1u     MOV     Moves value from one register to another
                                   DST = SRC1
      14h-17h ?      ???     ?
      18h     1i     DPHI    Computes dot product on a 3-component vector
                             with 1.0 appended to it and a 4-component vector;
                                   DST = SRC1.SRC2 (with SRC1 homogenous)
      19h     1i     DSTI    DST with sources swapped
      1Ah     1i     SGEI    Sets output if SRC1 is greater than or equal to SRC2
                                   DST[i] = (SRC1[i] >= SRC2[i]) ? 1.0 : 0.0
                                   "for all i"
      1Bh     1i     SLTI    Sets output if SRC1 is strictly less than SRC2
                                   DST[i] = (SRC1[i] < SRC2[i]) ? 1.0 : 0.0
                                   "for all i"
      1Ch-1Fh ?      ???     ?
      20h     0      BREAK   Breaks out of LOOP block; do not use while in
                             nested IF/CALL block inside LOOP block.
      21h     0      NOP     Does literally nothing.
      22h     0      END     Signals the shader unit that processing for this
                             vertex/primitive is done.
      23h     2      BREAKC  If condition (see below for details) is true, then
                             breaks out of LOOP block.
      24h     2      CALL    Jumps to DST and executes instructions until it
                             reaches DST+NUM instructions
      25h     2      CALLC   If condition (see below for details) is true, then
                             jumps to DST and executes instructions until it
                             reaches DST+NUM instructions, else does nothing.
      26h     3      CALLU   Jumps to DST and executes instructions until it
                             reaches DST+NUM instructions if BOOL is true
      27h     3      IFU     If condition BOOL is true, then executes instructions
                             until DST, then jumps to DST+NUM; else, jumps to DST.
      28h     2      IFC     If condition (see below for details) is true, then
                             executes instructions until DST, then jumps
                             to DST+NUM; else, jumps to DST
      29h     3      LOOP    Loops over the code between itself and DST
                             (inclusive), performing INT.x+1 iterations in total.
                             First, aL is initialized to INT.y. After each
                             iteration, aL is incremented by INT.z.
      2Ah     0      EMIT    (geometry shader only) Emits a vertex (and primitive
                             if FLAG_PRIMEMIT was set in the corresponding
                             SETEMIT). SETEMIT must be called before this.
      2Bh     4      SETEMIT (geometry shader only) Sets VTXID, FLAG_WINDING and
                             FLAG_PRIMEMIT for the next EMIT instruction. VTXID
                             is the ID of the vertex about to be emitted within
                             the primitive, while FLAG_PRIMEMIT is zero if we are
                             just emitting a single vertex and non-zero if are
                             emitting a vertex and primitive simultaneously.
                             FLAG_WINDING controls the output primitive's winding.
                             Note that the output vertex buffer (which holds 4
                             vertices) is not cleared when the primitive is
                             emitted, meaning that vertices from the previous
                             primitive can be reused for the current one. (this
                             is still a working hypothesis and unconfirmed)
      2Ch     2      JMPC    If condition (see below for details) is true, then
                             jumps to DST, else does nothing.
      2Dh     3      JMPU    If condition BOOL is true, then jumps to DST, else
                             does nothing. Having bit 0 of NUM = 1 will invert the
                             test, jumping if BOOL is false instead.
      2Eh-2Fh 1c     CMP     Sets booleans cmp.x and cmp.y based on the operand's
                             x and y components and the CMPX and CMPY comparison
                             operators respectively. See below for details about
                             operators. It's unknown whether CMP respects the
                             destination component mask or not.
      30h-37h 5i     MADI    Multiplies two vectors and adds a third one
                             component by component;
                                   DST[i] = SRC3[i] + SRC2[i].SRC1[i]
                                   "for all i"
                                   "this is not an FMA, the intermediate result is
                                   rounded"
      38h-3Fh 5      MAD     Multiplies two vectors and adds a third one
                             component by component;
                                   DST[i] = SRC3[i] + SRC2[i].SRC1[i]
                                   "for all i"
                                   "this is not an FMA, the intermediate result
                                   is rounded"

Shader Operand descriptors (OPDESC's)
Below 31bit (or 32bit?) are related to the 5bit/7bit "DESC" id's in opcode LSBs.

      0      Destination component mask W (0=Don't change, 1=Write)
      1      Destination component mask Z (0=Don't change, 1=Write)
      2      Destination component mask Y (0=Don't change, 1=Write)
      3      Destination component mask X (0=Don't change, 1=Write)
      4      Source 1 Negation bit
      5-6    Source 1 Component 3 value   (0..3 = X,Y,Z,W) (usually 3)
      7-8    Source 1 Component 2 value   (0..3 = X,Y,Z,W) (usually 2)
      9-10   Source 1 Component 1 value   (0..3 = X,Y,Z,W) (usually 1)
      11-12  Source 1 Component 0 value   (0..3 = X,Y,Z,W) (usually 0)
      13     Source 2 Negation bit
      14-15  Source 2 Component 3 value   (0..3 = X,Y,Z,W)
      16-17  Source 2 Component 2 value   (0..3 = X,Y,Z,W)
      18-19  Source 2 Component 1 value   (0..3 = X,Y,Z,W)
      20-21  Source 2 Component 0 value   (0..3 = X,Y,Z,W)
      22     Source 3 Negation bit
      23-24  Source 3 Component 3 value   (0..3 = X,Y,Z,W)
      25-26  Source 3 Component 2 value   (0..3 = X,Y,Z,W)
      27-28  Source 3 Component 1 value   (0..3 = X,Y,Z,W)
      29-30  Source 3 Component 0 value   (0..3 = X,Y,Z,W)
      31     unnown/unspecified/unused (usually 0)

The component selector (the 8bit fragments with 4x2bits) enables swizzling. For example, component selector 0x1B is equivalent to .xyzw, while 0x55 is equivalent to .yyyy.
Depending on the current shader opcode, source components are disabled implicitly by setting (*to ZERO*) the destination component mask. For example, ADD o0.xy, r0.xyzw, r1.xyzw will not make use of r0's or r1's z/w components, while DP4 o0.xy, r0.xyzw, r1.xyzw will use all input components regardless of the used destination component mask.
Relative addressing

      IDX  Address offset
      00h  +0       ;-no offset
      01h  +a0.x    ;\X or Y component of address register (see MOVA)
      02h  +a0.y    ;/
      03h  +lp      ;-loop counter (see LOOP)

There are 3 address registers: a0.x, a0.y and aL (loop counter). For format 1 instructions, when IDX != 0, the value of the corresponding address register is added to SRC1's value. For example, if IDX = 2, a0.y = 3 and SRC1 = c8, then instead SRC1+a0.y = c11 will be used for the instruction. It is only possible to use address registers with vector uniform registers, attempting to use them with input attribute or temporary registers results in the address register being ignored (i.e. read as zero).
a0.x and a0.y are set manually through the MOVA instruction by rounding a float value to integer precision. Hence, they may take negative values.
aL can only be set indirectly by the LOOP instruction. It is still accessible and valid after exiting a LOOP block, though.
Comparison operator

      CMPX/CMPY raw value   Operator name   Expression
      00h                   EQ              src1 == src2
      01h                   NE              src1 != src2
      02h                   LT              src1 < src2
      03h                   LE              src1 <= src2
      04h                   GT              src1 > src2
      05h                   GE              src1 >= src2
      06h                   ??              seems to always return true
      07h                   ??              seems to always return true

Conditions
A number of format 2 instructions are executed conditionally. These conditions are based on two boolean registers which can be set with CMP: cmp.x and cmp.y.
Conditional instructions include 3 parameters: CONDOP, REFX and REFY. REFX and REFY are reference values which are tested for equality against cmp.x and cmp.y, respectively. CONDOP describes how the final truth value is constructed from the results of the two tests. There are four conditional expression formats:

      CONDOP raw value    Expression                        Description
      00h                 cmp.x == REFX || cmp.y == REFY    OR
      01h                 cmp.x == REFX && cmp.y == REFY    AND
      02h                 cmp.x == REFX                     X
      03h                 cmp.y == REFY                     Y

Registers
Input attribute registers (v0-v7?) store the per-vertex data given by the CPU and hence are read-only.
Output attribute registers (o0-o6) hold the data to be passed to the later GPU stages and are write-only. Each of the output attribute register components is assigned a semantic by setting the corresponding GPU_Internal_Registers.
Uniform registers hold user-specified data which is constant throughout all processed vertices. There are 96 float[4] uniform registers (c0-c95), eight(???) boolean registers (b0-b7), and four int[4] registers (i0-i3).
Temporary registers (r0-r15) can be used for intermediate calculations and can both be read and written.
Many shader instructions which take float arguments have only 5 bits available for the second argument. They may hence only refer to input attributes or temporary registers. In particular, it's not possible to pass two float[4] uniforms to these instructions.
It appears that writing twice to the same output register can cause problems (eg. GPU hangs).
DST mapping:

      DST raw value  Register name   Description
      00h-06h?       o0-o6?          Output registers (aka output FIFO) (W)
      10h-1Fh        r0-r15          Temporary registers (R/W)

SRC1/SRC2/SRC3 mapping:

      SRC raw value  Register name   Description
      00h-07h?       v0-v7?          Input vertex/attribute (aka input FIFO) (R)
      10h-1Fh        r0-r15          Temporary registers
      20h-7Fh        c0-c95          Vector uniform registers (only for 7bit SRC)

Control Flow
Control flow is implemented using four independent stacks:

      4-deep CALL stack
      8-deep IF stack
      4-deep LOOP stack

All stacks are initially empty. After every instruction but before JMP takes effect, the PC is incremented and a copy is sent to each stack. Each stack is checked against its copy of the PC. If an entry is popped from the stack, the copied PC is updated and used for the next check of this stack, although the IF/LOOP stacks can each only pop one entry per instruction, whereas the CALL stack is checked again until it doesn't match or the stack is empty. The updated PC copy with the highest priority wins: LOOP (highest), IF, CALL, JMP, original PC (lowest).

3DS GPU Geometry Pipeline

Array Attributes (via ARRAY pointers)
The most common way seems to be drawing via GPUREG_ATTR_BUF_xxx and GPUREG_ATTR_BUF_DRAWARRAYS, the GPU is then automatically reading vertex data from the array pointers (instead of needing to send all vertices to the command buffer).
Fixed Vertex Attributes (fixed attr for ALL vertices)
To use a fixed attribute, set the bit corresponding to the attribute in GPUREG_ATTR_BUF_FORMAT_HIGH and ensure that no vertex arrays are configured for the attribute (any configured arrays will override the fixed value, regardless of the bit setting). Even if a vertex array isn't being used for the attribute it still needs to be counted in the number of active attributes specified in the same register.
Immediate-Mode Vertex Submission (via GPUREG_FIXEDATTRIB_DATA)
Instead of using vertex arrays to supply vertex data, drawing can be done by directly writing vertex data to a register. This allows vertex data to be inlined directly in the command buffer. Since this is restricted to 4-component float data, it is more useful for small draws like UI elements or debug displays, to avoid using an unreasonable amount of memory and processing time appending the vertices to the command buffer.
To use this feature, configure the number of attributes per vertex in GPUREG_VSH_NUM_ATTR. (All settings in the registers related to the vertex loader are ignored.) Then setup the GPU and shaders the same as if doing a regular draw call with GPUREG_ATTR_BUF_DRAWARRAYS or GPUREG_ATTR_BUF_DRAWELEMENTS, but instead of writing to either register, write the value 0xF to GPUREG_FIXEDATTRIB_INDEX and then follow by repeatedly writing vertex data to GPUREG_FIXEDATTRIB_DATA.
Each set of writes to the 3 data registers specifies one attribute and all attributes (as configured in GPUREG_VSH_NUM_ATTR) need to be written, in order, to specify a vertex. Drawing happens automatically as vertices are specified. After finishing specifying vertices, follow with the same writes used after a draw arrays/elements.

3DS GPU Fragment Lighting

Fragment lighting is a DMP extension to the standard OpenGL pipeline with which applications can calculate object lighting for each rendered pixel instead of just per vertex. The fragment lighting algorithm furthermore supports the shading models Blinn-Phong, Cook-Terrance, Ward, and microfacet-based BRDF-models. While the lighting calculations take place in a very localized position of the pixel processing pipeline, the feature interacts with different other pipeline stages.
Overview
In general, lighting is calculated at a particular point in space X by determining the angles (i.e. dot products) between different vectors:

      - The face normal vector N, which points from X to the direction
        perpendicular to the lighted object
      - The tangent vector T, which points from X to a direction which is
        tangential to the lighted object
      - The bitangent vector B, which points to a tangential direction such
        that it is orthogonal to both N and T
      - The view vector V, which points from X "into the camera"
      - The light vector L, which points from X to the light source (note that
        lighting is always evaluated separately for each light source; the
        results for multiple light sources can simply be added to each other)

For example, in the Blinn-Phong shading model the dot product of L and N determined the intensity of a lighting type called diffuse lighting. More generally, the dot products between these vectors (from now on simply referred to as "dot products") are combined to a lighting equation, which is evaluated once per light source at each considered point in space.
Before pixel shaders were common, the lighting equation was only considered at each vertex, and the output color was then interpolated across the triangle. To achieve higher visual quality, pixel shaders can be used nowadays to evaluate the lighting equation at each pixel. The PICA200 does not have a programmable pixel shader, but has a fixed-function pipeline stage to achieve the same quality.
In any case, per-pixel lighting requires to somehow obtain a normal vector for each pixel. Theoretically, the vertex shader could output one normal vector per vertex, and per-pixel normals could then be obtained by interpolating these vectors in a specific way. This, however, is very inefficient, which is why vertex shaders on the PICA200 instead output mathematical objects called quaternions: Quaternions can be computed from normal/tangent vectors, and vice versa, so no information is lost by doing so. However, quaternion interpolation is a lot faster (see the "Kuijk and Blake" source below), and so the GPU can compute per-pixel normals simply using the interpolated quaternion. This is just the general idea, and the dirty mathematical details are explained below.
In addition to allowing per-pixel calculations, the lighting equation used in the PICA200 involves using the dot products as indices into configurable lookup tables. A good example of why this is useful is cell-shading, which can be achieved simply by setting adjacent lookup table values to the same color.
Quaternions as Shader Outputs
The shaders are usually the point where normal and tangent vector information flows in. Usually, the source vertex data will include normal vectors for each vertex. This need not be the case though; one could also just input raw vertex positions, and have a geometry shader automatically calculate normal vector information.
In any case: There is no vertex output attribute semantic for normal or tangent vectors. To use fragment lighting, the shader must actually output an attribute with the quaternion semantic. So some sort of conversion needs to happen from normal and tangent vectors to quaternions. This can be done using the surface-local matrix.
Quaternion Interpolation
Quaternion interpolation needs to happen to obtain a per-fragment quaternion, from which in turn per-fragment normals and tangent vectors can be computed. It is unknown how quaternions are interpolated on the PICA200. The architecture suggests that plain linear interpolation is used, but there are also more sophisticated algorithms like Slerp and Nlerp.
Quaternions and Normal/Tangent Vectors
Quaternions describe a transformation from surface-local space to eye space. In surface-local space, by definition (and up to permutation) the normal vector is (0,0,1), the tangent vector is (1,0,0), and the bitangent vector is (0,1,0).
Alternatively, one may consider quaternions a transformation from eye space to surface-local space.
Fragment Lighting Equation
There are two lighting equations: One for the primary color and one for the secondary color. Both of them are given in section 3.2.2 of the "Kazakov and Ohbuchi" source below. In addition, the fragment lighting can be set up to write to the alpha channel of the primary or secondary color depending on a selectable angle and a LUT. The equations used can be found here: http://mathb.in/26766
Some common setups include:

      ------------------------------------------------
      Model:            Blinn-Phong
      LutD0:            Input: N dot H, Contents: x^s
      LutD1:            --
      ReflectionLuts:   --
      Geometry factors: Disabled
      SpotlightLut      Spotlight setup or no-op
      ------------------------------------------------
      Model:            Cook-Torrance
      LutD0:            --
      LutD1:            Input: N dot H, D(x)
      ReflectionLuts:   Input: V dot H, Contents: F(x)
      Geometry factors: Enabled
      SpotlightLut      Spotlight setup or no-op
      ------------------------------------------------
      Model:            Schlick-like
      LutD0:            --
      LutD1:            Input: N dot H, Contents: Schlick Z(x)
      ReflectionLuts:   Input: V dot H, Contents: F(x)
      Geometry factors: Enabled
      SpotlightLut      Input: cos phi_i, Contents: Schlick A(x)
      ------------------------------------------------
      Model:            Subsurface scattering (?)
      LutD0:            --
      LutD1:            Input: N dot V, Contents: Transmittance by angle
      ReflectionLuts:   Input: L dot N, Contents: Reflectance by angle
      Geometry factors: Disabled
      SpotlightLut      Spotlight setup or no-op
      ------------------------------------------------

s is the specularity factor for Blinn-Phong.
Spotlight setup means input -L dot P and contents spotlight falloff.
F and D can be found in http://inst.cs.berkeley.edu/~cs294-13/fa09/lectures/cookpaper.pdf
Schlick Z and Schlick A are defined in http://www.cs.virginia.edu/~jdl/bib/appearance/analytic%20models/schlick94b.pdf
The Fresnel LUT can be used to, for example, blend two colours according to how oblique the view angle is, or to simply additively blend white onto fragments with an exponential falloff, resulting in rim lighting.
Fragment Lighting Output
The fragment lighting results are accessible as two inputs to the texture combiners (one for the primary color, one for the secondary color).
Resources
There is public literature available which describes the fragment lighting feature in more detail:

      - Everitt - "Per-Pixel Lighting": A presentation given at the Game
        Developers Conference 2001 about per-pixel lighting. It doesn't have
        anything to do with the PICA200 algorithm, but explains the core ideas
        very well (especially the concepts of surface-local space and how it
        relates to other coordinate systems).
      - Kazakov and Ohbuchi - "Primitive Processing and Advanced Shading
        Architecture for Embedded Space": Provides a general overview over the
        fragment lighting algorithm used by the PICA200 and provides explicit
        formulas for the primary and secondary lighting output. NOTE: There exist
        both a scientific publication and a short presentation with this title.
        Both are useful, but the former goes into much greater detail.
      - Ohbuchi and Unno - "A Real-Time Configurable Shader Based on Lookup
        Tables": Provides a very detailed explanantion of the fragment lighting
        implementation
      - Kuijk and Blake - "Faster Phong Shading via Angular Interpolation":
        Explains in greater detail how quaternions can be used to encode
        information about normals and tangents (and how quaternions are easier to
        interpolate than vectors).

3DS GPU Pitfalls

Vertex attribute alignment
Vertex components which are defined through GPUREG_ATTR_BUFi_CONFIG_LOW will be accessed aligned by the GPU.
Vertex attributes will be aligned to their component element size.
Padding attributes (Component type > 11) will always aligned to 4 byte offets into the buffer.
The stride which is passed to the GPU should be passed unaligned.
Vertex stride in GPUREG_ATTR_BUFi_CONFIG_HIGH
The vertex stride set in GPUREG_ATTR_BUFi_CONFIG_HIGH must match the actual size of the vertex contained in the buffer or the PICA will freeze or it won't draw anything.
If you want to use a different stride you have to pad the data accordingly with padding attributes.
Output mapping in GPUREG_SH_OUTMAP_MASK
The output masking in GPUREG_SH_OUTMAP_MASK influences how the registers starting at GPUREG_SH_OUTMAP_Oi map to outputs in the shader.
If an output is disabled in GPUREG_SH_OUTMAP_MASK it means that no slot in the GPUREG_SH_OUTMAP_Oi registers is consumed. GPUREG_SH_OUTMAP_TOTAL configures the number of used consecutive slots in the outmap. Example:

      GPUREG_SH_OUTMAP_TOTAL = 0x00000002      ;2 outputs enabled
      GPUREG_SH_OUTMAP_MASK  = 0x00000011      ;o0 enabled, o4 enabled
      GPUREG_SH_OUTMAP_O0    = 0x03020100      ;o0 = pos.xyzw
      GPUREG_SH_OUTMAP_O1    = 0x0B0A0908      ;o4 = color.rgba    ;<-- o4 in "O1"!
      GPUREG_SH_OUTMAP_O2    = ...             ;(unused)

Shaders - Configued Output components must be written exactly once
Each configured output component has to be written exactly once or the PICA freezes.
Shaders - MOVA instructions can't be adjacent
Having 2 consecutive MOVA instructions will freeze the PICA. This can be relaxed by placing a NOP between 2 MOVAs or by rearranging the code.
Shader - Special cases
JMP overwrites the PC *after* the stacks checks (and only if no stack was popped).
Executing a BREAK on an empty LOOP stack hangs the GPU.
A stack overflow discards the oldest element, so you could think of it as a queue or a ring buffer.
If the CALL stack is popped four times in a row, the fourth update to its copy of the PC is missed (the third PC update will be propagated). Probably a hardware bug.
Shader - Floating-Point Behavior
The PICA200 is not IEEE-compliant. It has positive and negative infinities and NaN, but does not seem to have negative 0. Input and output subnormals are flushed to +0. The internal floating point format seems to be the same as used in shader binaries: 1 sign bit, 7 exponent bits, 16 (explicit) mantissa bits. Several instructions also have behavior that differs from the IEEE functions. Here are the results from some tests done on hardware (s = largest subnormal, n = smallest positive normal):

      Computation     Result  Notes
      inf * 0         0       Including inside MUL, MAD, DP4, etc.
      NaN * 0         NaN
      +inf - +inf     NaN     Indicates +inf is real inf, not FLT_MAX
      rsq(rcp(-inf))  +inf    Indicates that there isn't -0.0.
      rcp(-0)         +inf    no -0 so differs from IEEE where rcp(-0) = -inf
      rcp(0)          +inf
      rcp(+inf)       0
      rcp(NaN)        NaN
      rsq(-0)         +inf    no -0 so differs from IEEE where rsq(-0) = -inf
      rsq(-2)         NaN
      rsq(+inf)       0
      rsq(-inf)       NaN
      rsq(NaN)        NaN
      max(0, +inf)    +inf
      max(0, -inf)    -inf
      max(0, NaN)     NaN     max violates IEEE but match GLSL spec
      max(NaN, 0)     0
      max(-inf, +inf) +inf
      min(0, +inf)    0
      min(0, -inf)    -inf
      min(0, NaN)     NaN     min violates IEEE but match GLSL spec
      min(NaN, 0)     0
      min(-inf, +inf) -inf
      cmp(s, 0)       false   cmp does not flush input subnormals
      max(s, 0)       s       max does not flush input or output subnormals
      mul(s, 2)       0       input subnormals are flushed in arithmetic
                                instructions
      mul(n, 0.5)     0       output subnormals are flushed in arithmetic
                                instructions

1.0 can be multiplied 63 times by 0.5 until the result compares equal zero. This is consistent with a 7-bit exponent and output subnormal flushing.
Command list related
Invalid GPU command parameters including NaN floats can cause the GPU to hang, which then causes the "GSP module" to hang as well.

3DS GPU Primitive Engine and Shaders

The 3DS seems to have four "shaders", each with there own I/O ports. However, the vertex shaders seem to be used in parallel (to process 3 or 4 vertices at once... so it's unknown if one needs to initialize all sets of I/O ports separately; 3dbrew seems to have only two shaders documented (GSH and VSH), without even being aware of the VSH2 and VSH3 registers.
Vertex Shader (VSH)
The Vertex Shader is used to forward incoming vertex data (coordinates, colors, texcoords) to the drawing engine. Most commonly, the shader would be used to multiply the incoming coordinates with a Position Matrix and/or Projection Matrix.
Geometry Shader (GSH)
The Geometry Shader can be used to do something... but it appears to be unknown what, and how.
It can probably somehow receive incoming values from somewhere. And probably output values to somewhere (maybe somehow forwarding them to other GPU registers, and maybe somehow sending them as response to the CPU).
The "EMIT" opcode might output data from Geometry Shader to Vertex shader?
The "Primitive Engine" section below might refer to the geometry shader?
Primitive Engine
Primitive Engine (PE) is one of the PICA200's four vertex processor units and provides some unique features which are used to implement a geometry shader stage and variable-size primitive rendering.
The full functionality of PE is not yet understood and remains to be reverse-engineered.
Variable-size primitives are implemented by prefixing each per-primitive sequence of indices in an index array with a primitive size. This is used for various effects, for example Catmull-Clark subdivision and Loop subdivision. It is unknown how this feature is enabled specifically.

3DS GPU Triangle Drawing Sample Code

     _________________________ Triangle Drawing Examples __________________________

gpu_draw_triangle_direct: ;simple, but requires a messy 3x24bit data format

      gpu_clear_colorbuf, gpu_init_framebuf, gpu_init_vertex_shader
     ;[GPUREG_GEOSTAGE_CONFIG]=((1 shl 8)+00h) ;not needed
      [GPUREG_GEOSTAGE_CONFIG2]=(0 shl 8)+01h  ;needed
     ;[GPUREG_START_DRAW_FUNC0]=00h  ;not needed, 0=draw, 1=config?
      [GPUREG_FIXEDATTRIB_INDEX]=0Fh  ;mode for directly writing vertex data...
      for i=0 to (4*2)-1
        [GPUREG_FIXEDATTRIB_DATA+0]=[@@array+i*0Ch+8] ;\write 4x24bit as 3x32bit
        [GPUREG_FIXEDATTRIB_DATA+0]=[@@array+i*0Ch+4] ; upper 32bit written first
        [GPUREG_FIXEDATTRIB_DATA+0]=[@@array+i*0Ch+0] ;/
      next i
      gpu_copy_colorbuf_to_lcd_framebuf
      ret
     @@array: ;x______y______z______w______r______g______b______a_____
      .float24 -1.0  ,-1.0  ,0.0   ,1.0   ,1.0   ,0.5   ,0.5   ,1.0 ;\1st triangle
      .float24 1.0   ,0.4   ,0.0   ,1.0   ,0.5   ,1.0   ,0.5   ,0.5 ;  ;\2nd
      .float24 0.2   ,1.0   ,0.0   ,1.0   ,0.5   ,0.5   ,1.0   ,0.5 ;/ ; triangle
      .float24 1.0   ,-0.8  ,-1.0  ,1.0   ,0.5   ,0.5   ,1.0   ,0.5    ;/(of strip)
      ;note: coord.W must be 1.0 (to avoid perspective division)

gpu_draw_triangle_via_buffer: ;example with 1-2 arrays, optional index_list

     @@numattr equ 2 ;configure for two attributes (coordinate and color)
      gpu_clear_colorbuf, gpu_init_framebuf, gpu_init_vertex_shader
      [GPUREG_ATTR_BUF_BASE]=(((@@base)/10h)*2)
      [GPUREG_ATTR_BUF_FORMAT_LOW]=9Ch  ;Signed8bit(x,y,z,w)+Unsigned8bit(r,g,b)
      [GPUREG_ATTR_BUF_FORMAT_HIGH]=((@@numattr-1) shl 28)+(000h shl 16)
      if @@num_arrays=1      ;both coordinate and color in one array...
       [GPUREG_ATTR_BUFi_OFFSET+0*0Ch]=(@@array-@@base)/1
       [GPUREG_ATTR_BUFi_CONFIG_LOW+0*0Ch]=76543210h
       [GPUREG_ATTR_BUFi_CONFIG_HIGH+0*0Ch]=(@@numattr shl 28)+((4+3) shl 16)+BA98h
      elseif @@num_arrays=2  ;coordinate and color in separate arrays...
       [GPUREG_ATTR_BUFi_OFFSET+0*0Ch]=(@@array0-@@base)/1
       [GPUREG_ATTR_BUFi_OFFSET+1*0Ch]=(@@array1-@@base)/1
       [GPUREG_ATTR_BUFi_CONFIG_LOW+0*0Ch]=00000000h
       [GPUREG_ATTR_BUFi_CONFIG_LOW+1*0Ch]=00000001h
       [GPUREG_ATTR_BUFi_CONFIG_HIGH+0*0Ch]=(01h shl 28)+(04h shl 16)+0000h
       [GPUREG_ATTR_BUFi_CONFIG_HIGH+1*0Ch]=(01h shl 28)+(03h shl 16)+0000h
      endif
     ;[GPUREG_GEOSTAGE_CONFIG] =((1 shl 8)+00h)  ;not needed
      [GPUREG_GEOSTAGE_CONFIG2]=(1 shl 8)+01h    ;needed
     ;[GPUREG_START_DRAW_FUNC0]=00h              ;not needed, 0=draw, 1=config?
      [GPUREG_ATTR_BUF_NUMVERTICES]=4*(1+@@use_index_list)  ;needed, array size
      if @@use_index_list    ;with index list...
        [GPUREG_ATTR_BUF_INDEX_LIST]=(0 shl 31)+(@@index_list-@@base)/1
        [GPUREG_ATTR_BUF_DRAWELEMENTS]=0   ;start drawing via above index list
      else                   ;without index_list...
        [GPUREG_ATTR_BUF_FIRST_INDEX]=0    ;first index
        [GPUREG_ATTR_BUF_DRAWARRAYS]=0     ;start drawing at above index number
      endif
      gpu_copy_colorbuf_to_lcd_framebuf
      ret
     align 10h
     @@base:
     if @@use_index_list
       @@index_list: db 0,1,2,3   ;index to 1st,2nd,3rd,4th entries in arrays
     endif
     if @@num_arrays=1
      @@array: ;x______y______z______w______r______g______b______a_____
       db       -7fh  ,-7fh  ,0     ,+7fh  ,0ffh  ,0     ,0          ;\1st triangle
       db       +7fh  ,+40h  ,0     ,+7fh  ,0     ,0ffh  ,0          ;  ;\2nd
       db       +20h  ,+7fh  ,0     ,+7fh  ,0     ,0     ,0ffh       ;/ ; triangle
       db       +7fh  ,-60h  ,0     ,+7fh  ,0     ,0ffh  ,0ffh          ;/of strip
     elseif @@num_arrays=2
      @@array0: ;x______y______z______w____
       db        -7fh  ,-7fh  ,0 -9  ,+7fh  ;\1st triangle
       db        +7fh  ,+40h  ,0 -9  ,+7fh  ;  ;\2nd
       db        +20h  ,+7fh  ,0 -9  ,+7fh  ;/ ; triangle
       db        +7fh  ,-60h  ,-7fh  ,+7fh     ;/of strip
      @@array1: ;r______g______b______a_____
       db        0ffh  ,0     ,0             ;\1st triangle
       db        0     ,0ffh  ,0             ;  ;\2nd
       db        0     ,0     ,0ffh          ;/ ; triangle
       db        0     ,0ffh  ,0ffh             ;/of strip
     endif

     _____________________ Init and Memory Transfer Functions _____________________

gpu_clear_colorbuf:

      [GPUREG_RENDERBUFFER_INVALIDATE]=1   ;forget cache
      [GPU_MEMFILL_DST_ADDR0]=(MEMORG_COLORBUF+0)/10h*2
      [GPU_MEMFILL_DST_END0]=(MEMORG_COLORBUF+320*240*4)/10h*2
      [GPU_MEMFILL_DATA0]=11441100h
      [GPU_MEMFILL_CNT0]=00000201h
      wait until [GPU_MEMFILL_CNT0].bit0=0
      ret

gpu_copy_colorbuf_to_lcd_framebuf:

      DummyRead=[GPUREG_STAT_NUM_TRIANGLES_DISPLAYED]  ;waits until rendering done
      [GPUREG_RENDERBUFFER_FLUSH]=1   ;cache writeback
      [GPU_MEMCOPY_SRC_ADDR]=MEMORG_COLORBUF/10h*2
      [GPU_MEMCOPY_DST_ADDR]=MEMORG_SCREEN1/10h*2
      [GPU_MEMCOPY_DISPLAY_SIZE]=(240 shl 0)+(320 shl 16)
      [GPU_MEMCOPY_REMAIN_IRQ]=3FFFh  ;want IRQ flag when done
      [GPU_MEMCOPY_FLAGS]=0
      [GPU_MEMCOPY_CNT]=1
      ;caution: polling GPU_MEMCOPY_CNT can HANG the CPU at transfer end!
      ;instead: poll GPU_STAT_IRQ_FLAGS...
      wait until: [GPU_STAT_IRQ_FLAGS].bit30=1
      ret

gpu_init_framebuf:

     ;[GPUREG_RENDERBUFFER_INVALIDATE]=1   ;forget cache
      [GPUREG_FACECULLING_CONFIG]=0 ;show front+back
      [GPUREG_RENDERBUFFER_DIM_0]=(1 shl 24)+(320-1)*1000h+240
     ;[GPUREG_RENDERBUFFER_DIM_1]=(1 shl 24)+(320-1)*1000h+240
      [GPUREG_DEPTHBUFFER_LOC]=MEMORG_DEPTHBUF/40h*8
      [GPUREG_COLORBUFFER_LOC]=MEMORG_COLORBUF/40h*8
      [GPUREG_VIEWPORT_V_SCALE]=0045E000h ;240/2 ;.float24 120.0 // db 00h
      [GPUREG_VIEWPORT_H_SCALE]=00464000h ;320/2 ;.float24 160.0 // db 00h
      [GPUREG_VIEWPORT_V_STEP]=38111100h  ;2/240 ;db 00h // .float24 0.008333333
      [GPUREG_VIEWPORT_H_STEP]=37999900h  ;2/320 ;db 00h // .float24 0.006250000
      [GPUREG_VIEWPORT_XY]=(0 shl 16)+0
      [GPUREG_SCISSORTEST_MODE]=0
     ;[GPUREG_SCISSORTEST_POS1]=((0+20) shl 16)+(0+20)
     ;[GPUREG_SCISSORTEST_POS2]=((320-1-20) shl 16)+(240-1-20)
      [GPUREG_COLOR_OPERATION]=00e40100h
      [GPUREG_BLEND_FUNC]=06020000h ;raw drawing
     ;[GPUREG_BLEND_FUNC]=76760000h ;alpha blending
     ;[GPUREG_LOGIC_OP]=00h
      [GPUREG_FRAGOP_ALPHA_TEST]=00h
      [GPUREG_STENCIL_TEST]=00h
      [GPUREG_DEPTH_COLOR_MASK]=1F00h
      [GPUREG_COLORBUFFER_READING]=0Fh
      [GPUREG_COLORBUFFER_WRITING]=0Fh
      [GPUREG_DEPTHBUFFER_READING]=03h
      [GPUREG_DEPTHBUFFER_WRITING]=03h
      [GPUREG_DEPTHBUFFER_FORMAT]=03h
      [GPUREG_COLORBUFFER_FORMAT]=02h
      [GPUREG_RENDERBUFFER_BLOCK32]=0
     ;[GPUREG_EARLYDEPTH_TEST1]=0
     ;[GPUREG_EARLYDEPTH_TEST2]=0
      [GPUREG_DEPTHMAP_ENABLE]=1
      [GPUREG_DEPTHMAP_SCALE]=00bf0000h  ;far z  (-1.0)
      [GPUREG_DEPTHMAP_OFFSET]=00000000h ;near z (0.0)
      ret

gpu_init_vertex_shader:

     @@numattr equ 2 ;configure for two attributes (coordinate and color)
      [GPUREG_SH_OUTMAP_TOTAL]=@@numattr      ;vertex+color
      [GPUREG_SH_OUTMAP_O+0*4]=03020100h      ;vertex.xyzw
      [GPUREG_SH_OUTMAP_O+1*4]=0b0a0908h      ;color.rgba
      [GPUREG_SH_OUTATTR_CLOCK]=3             ;bit0=blah?, bit1=needed for colors
      [GPUREG_VSH_COM_MODE]=00h               ;GSH/VSH?
      [GPUREG_VSH_NUM_ATTR]=@@numattr-1       ;needed
      [GPUREG_VSH_OUTMAP_TOTAL1]=@@numattr-1  ;needed
     ;[GPUREG_VSH_OUTMAP_TOTAL2]=@@numattr-1  ;not needed
      [GPUREG_START_DRAW_FUNC0]=1             ;needed
      [GPUREG_VSH_INPUTBUFFER_CONFIG]=(0a0h shl 24)+@@numattr-1
      [GPUREG_PRIMITIVE_CONFIG]=(1 shl 8)+@@numattr-1
      [GPUREG_RESTART_PRIMITIVE]=0  ;required for strips (even BEFORE first strip)
      [GPUREG_VSH_ATTR_PERMUTATION_LOW]=076543210h  ;\input
      [GPUREG_VSH_ATTR_PERMUTATION_HIGH]=0fedcba98h ;/
      [GPUREG_VSH_OUTMAP_MASK]=(1 shl @@numattr)-1        ;-output enable's
      [GPUREG_VSH_CODETRANSFER_INDEX]=000h/4
      [GPUREG_VSH_CODETRANSFER_DATA+0]=4C000000h  ;MOV o0,v0  ;used for coord xyzw
      [GPUREG_VSH_CODETRANSFER_DATA+0]=4C201000h  ;MOV o1,v1  ;used for color rgba
      [GPUREG_VSH_CODETRANSFER_DATA+0]=88000000h  ;END
      [GPUREG_VSH_CODETRANSFER_END]=0
      [GPUREG_VSH_OPDESCS_INDEX]=000h
      [GPUREG_VSH_OPDESCS_DATA+0]=0000036Fh  ;dst=xyzw, src1=xyzw (or rgba)
      [GPUREG_VSH_ENTRYPOINT]=7fff0000h+(000h/4)
      ret

3DS Video CAM Registers (Camera Input)

10120000h - CAM0 (external Right-Eye & internal Self-Facing camera) (as DSi)
10121000h - CAM1 (external Left-Eye camera) (extra 3DS camera)

      1012x000h 4     R/W mask: 0000ef1ch  ;CAM_CNT alike DSi cameras
      1012x004h 2     R   mask: 8500h      ;CAM_STAT unlike DSi (lsbs=0..500h)
      1012x006h 2     R/W mask: 003fh      ;CAM_???
      1012x010h 4     R/W mask: 01ff03feh  ;CAM_SOFS alike DSi cameras
      1012x014h 4     R/W mask: 01ff03feh  ;CAM_EOFS alike DSi cameras
      1032x000h 80h   R                    ;CAM_DAT fifo (20h-word window)

The ARM registers are similar (but not identical) as for DSi cameras,
DSi Cameras
The I2C bus camera init does work same as on DSi (for Aptina cameras),
DSi I2C Bus
Cameras must be enabled in CFG11_CAMERA_CNT (Port 10141224h).
1012x000h - CAM_CNT - mask: 0000ef1ch - Control (R/W)

      0     Unknown (status, toggles on/off during transfer?)                 (R)
      1     Unknown (status, gets set during transfer?)                       (R)
      2     Unknown (MUST be 0, else picture gets blank?)                     (R/W)
      3     Unknown (0=Normal/YUV422, 1=Some other data format?)              (R/W)
      4     Unknown (MUST be 1, else data transfer hangs, maybe reset?)       (R/W)
      5-7   Unused (0)                                                        (-)
      8     Unknown (no effect?)                                              (R/W)
      9     IRQ Enable      (0=Disable, 1=Enable) (at picture end?)           (R/W)
      10    Unknown (no effect?)                                              (R/W)
      11    Unknown (no effect?)                                              (R/W)
      12    Unused (0)                                                        (-)
      13    Unknown (MUST be 0, else data transfer hangs)                     (R/W)
      14    DMA Data Request enable (0=Disable, 1=Enable)                     (R/W)
      15    Transfer Enable (0=Disable/AllowConfig, 1=Enable/Transfer)        (R/W)
      16-31 Unused (0)                                                        (-)

1012x004h - CAM_STAT - Status (R)

      0-10  Number of 8-byte units (?) in FIFO (0..500h)                      (R)
      11-14 Unused? (0)                                                       (?)
      15    Overrun error, deadlock   (0=Normal, 1=Overrun)                   (R)

Caution: There will be no further data received after overrun. To avoid overrun, be sure to read data fast enough, and disable CAM_CNT.bit15 after reading the camera bitmap.
1012x006h - CAM_??? - Unknown (R/W)

      0-5   Unknown (no effect?) (can be set to 0..3Fh)                       (R/W)
      6-14  Unused? (0)                                                       (?)
      15    Clear overrun  (0=No change, 1=Clear; when CAM_CNT.bit15=0)       (W)

Unknown, seems to have no direct effect on the camera picture. Maybe selects timings or amount of words for DMA requests? Or maybe some bits resemble DSi's CAM_MCNT register?
1012x010h - CAM_SOFS alike DSi cameras (0..01FF03FEh) (R/W)
1012x014h - CAM_EOFS alike DSi cameras (0..01FF03FEh) (R/W)

      0      Unused (0)                                                         (0)
      1-9    X-Offset  (0..1FFh)   in words (ie. 2-pixel units)?         (R or R/W)
      10-15  Unused (0)                                                         (0)
      16-24  Y-Offset  (0..1FFh)   in scanlines?                         (R or R/W)
      25-31  Unused (0)                                                         (0)

Looks same as on DSi, but the settings seem to have no effect on 3DS, ie. there appears to be no way to enable the trimming feature?
1032x000h..1032x07Fh - CAM_DAT - Data FIFO (20h words window) (R)
The FIFO read window is 20h words in size (the actual FIFO is bigger; about 500h or A00h words?). The (default) data format is same as the YUV422 format for DSi cameras:

      0-7   First Pixel Luminance (Y)   (unsigned, 00h..FFh, FFh=white)
      8-15  Both Pixels Blue (Cb aka U) (unsigned, 00h..FFh, 80h=gray)
      16-23 Second Pixel Luminance (Y)  (unsigned, 00h..FFh, FFh=white)
      24-31 Both Pixels Red (Cr aka V)  (unsigned, 00h..FFh, 80h=gray)

Caution: It is important to read words from INCREASING addresses at 1032x000h..1032x07Fh (or at least toggle address bit2 after each read) (trying to read words from FIXED address 1032x000h will return the same word endless repeated).
Camera Notes
The "camera in-use" LED for external camera is controlled via MCU (but the LED exists on DSi/3DS only, New3DS doesn't have that LED installed).
The three 3DS/New3DS cameras have the same Chip IDs (2280h) as found in the two DSi's Aptina MT9V113 cameras.
However, New3DS is said to have improved picture quality. Unknown what that means, maybe the I2C registers are simply initialized with better gain settings at software side, or maybe the camera hardware is actually improved despite of having the same chip id.
New3DS is also said to support eye-tracking, whatever that means, it is probably done using the internal camera. And New3DS is said to have an IR-LED next to the internal camera to assist eye-tracking (yet unknown if/how the YUV/RGB camera could see IR-light at all).

3DS Video Y2R Registers (YUV-to-RGBA Converter)

Y2R Registers (aka YUV-to-RGB aka YCbCr-to-RGB)

      10102000h ARM11/ARM9  Y2R_0 Registers              ;\original Y2R unit
      10302000h ARM11       Y2R_0 FIFOs                  ;/(intended for camera)
      10132000h ARM11/ARM9  Y2R_1 Registers   ;\New3DS   ;\extra New3DS Y2R unit
      10332000h ARM11       Y2R_1 FIFOs       ;/         ;/(intended for MVD)

The Y2R unit(s) are general purpose YUV-to-RGB converters for photo/video decoding. The first Y2R unit was invented for the camera, the second Y2R unit for MVD on New3DS. The two units appear to be identical.

      10102000h/10132000h 4   Y2R_CNT                    R/W: E8C31F07h ;\
      10102004h/10132004h 2   Y2R_WIDTH   ;width (pix)   R/W: 03F8h     ;
      10102006h/10132006h 2   Y2R_HEIGHT  ;height (pix)  R/W: 03FFh     ;
      10102008h/10132008h ??  Y2R_STROBE  ;ack fifo?     dummy r/w?     ;
      10102010h/10132010h 2   Y2R_MULTIPLIER_Y_TO_RGB    R/W: 03FFh     ; Control
      10102012h/10132012h 2   Y2R_MULTIPLIER_V_TO_R      R/W: 03FFh     ; Regs
      10102014h/10132014h 2   Y2R_MULTIPLIER_V_TO_G      R/W: 03FFh     ;
      10102016h/10132016h 2   Y2R_MULTIPLIER_U_TO_G      R/W: 03FFh     ;
      10102018h/10132018h 2   Y2R_MULTIPLIER_U_TO_B      R/W: 03FFh     ;
      1010201Ah/1013201Ah 2   Y2R_OFFSET_R  ;\           R/W: FFFFh     ;
      1010201Ch/1013201Ch 2   Y2R_OFFSET_G  ; signed     R/W: FFFFh     ;
      1010201Eh/1013201Eh 2   Y2R_OFFSET_B  ;/           R/W: FFFFh     ;
      10102020h/10132020h 2   Y2R_ALPHA  ;bit7 for 5551  R/W: 000000FFh ;
      10102100h/10132100h 4   Y2R_DITHER0                R/W: 0000CCCCh ;
      10102108h/10132108h 4   Y2R_DITHER1                R/W: 0000CCCCh ;
      10102110h/10132110h 4   Y2R_DITHER2                R/W: 0000CCCCh ;
      10102118h/10132118h 4   Y2R_DITHER3                R/W: 0000CCCCh ;/
      10302000h/10332000h 80h Y2R_INPUT_Y    ;aka Luma   W:             ;\
      10302080h/10332080h 80h Y2R_INPUT_U    ;aka Cb     W:             ; FIFO's
      10302100h/10332100h 80h Y2R_INPUT_V    ;aka Cr     W:             ; (ARM11)
      10302180h/10332180h 80h Y2R_INPUT_YUYV ;Y1,U,Y2,V  W: (camera)    ;
      10302200h/10332200h 80h Y2R_OUTPUT_RGBA            R: (RGBA)      ;/

10102000h/10132000h - Y2R_CNT (R/W)

      0-2   Input Format YUV (0-4 = 422'8, 420'8, 422'16, 420'16, 422'BATCH)  (R/W)
      3-7   Unused (0)
      8-9   Output Format RGBA      (0=8888, 1=8880, 2=5551, 3=5650)          (R/W)
      10-11 Output Clockwise Rotate (0=None, 1=90', 2=180', 3=270')           (R/W)
      12    Output Swizzle          (0=LinearFramebuf, 1=MortonSwizzleTexture)(R/W)
      13-14 Unused (0)
      15    Unknown, reportedly used, but always 0 (maybe write-only?)          (?)
      16    Brightness Dither Enable   (0=No, 1=Use Y2R_DITHER0-3)            (R/W)
      17    Brightness Ugly Pulsation? (0=No, 1=Add 0,1,2,3 in frame 0,1,2,3) (R/W)
      18-20 Unused (0)
      21    Unknown, reportedly used, but always 0 (maybe write-only?)          (?)
      22    Input DMA Enable               (0=Disable, 1=Enable CDMA 09h/15h) (R/W)
      23    Output DMA Enable              (0=Disable, 1=Enable CDMA 0Ah/16h) (R/W)
      24    Input DRQ Y?                   (0=No, 1=DRQ) (write 1 to ack?) (R/ack?)
      25    Input DRQ U?                   (0=No, 1=DRQ) (write 1 to ack?) (R/ack?)
      26    Input DRQ V?                   (0=No, 1=DRQ) (write 1 to ack?) (R/ack?)
      27    Input DRQ YUYV (batch)         (0=No, 1=DRQ) (write 1 to ack?) (R/ack?)
      28    Output DRQ RGB, 9th input line (0=No, 1=DRQ) (write 1 to ack?) (R/ack?)
      29    Interrupt upon DRQ(s)?         (0=Disable, 1=Enable IRQ 4Bh/4Eh)  (R/W)
      30    Interrupt upon Transfer done   (0=Disable, 1=Enable IRQ 4Bh/4Eh)  (R/W)
      31    Start/Busy                     (0=Idle/Ready, 1=Start/Busy)       (R/W)

Input formats...

      INPUT_YUV422_INDIV_8   0     is that 8bit? or 8x8pix? or divide by 8?
      INPUT_YUV420_INDIV_8   1
      INPUT_YUV422_INDIV_16  2     is that 16bit? or 16x16pix? or divide by 16?
      INPUT_YUV420_INDIV_16  3
      INPUT_YUV422_BATCH     4     aka camera YUYV

Conversion is done in units of 8 lines. However, the first Input block must be 9 lines (unless the total height is smaller), and the final blocks can be smaller (depending on amount of remaining lines). For example:

      Send 9,8,8,8,8,3 scanlines    ;\for 44 scanlines
      Recv 8,8,8,8,8,4 scanlines    ;/

The odd amount of sending 9 lines in 1st block might allow to keep converting data while receiving responses.

      XXX does that 9-lines-input thing also apply to Input Format 0-3 ?

10102004h/10132004h - Y2R_WIDTH

      0-2   Unused (0)
      3-9   Width, in 8-pixel units (01h..7Fh=8..1016 pix, or 00h=?)
      10-15 Unused (0)

10102006h/10132006h - Y2R_HEIGHT

      3-9   Height in 1-pixel units (001h..3FFh=1..1023 pix, or 000h=?)
      10-15 Unused (0)

10102008h/10132008h - Y2R_STROBE ;ack fifo? dummy r/w?
Unknown, there is no read/write-able data here, and the register is normally left unused, however, reading or writing-any-value seems to strobe/trigger/ack/reset some internal stuff?
Standard YUV to RGB Formula (aka YCbCr to RGB)
The standard formula uses the constants shown below. However, one can also different values in the Y2R_MULTIPLIER_xxx and Y2R_OFFSET_xxx registers (that would allow to support other YUV variants, or to adjust more pale or more colorful output, or even to change RGB to BGR order; if the input FIFOs are also swapped accordingly).

      R = Y*1.00 + (Cr-80h)*1.402
      G = Y*1.00 - (Cr-80h)*0.714)-(Cb-80h)*0.344
      B = Y*1.00 + (Cb-80h)*1.772
      Clip results to MinMax(00h,FFh), and apply final divide by 8 for RGB555.

Note: In the standard YUV-to-RGB formula one would usually subtract 80h from the U/V values before multiplication. However, the 3DS does instead add variable offsets after multiplication (so those offsets need to be matched to the multipliers).
10102010h/10132010h - Y2R_MULTIPLIER_Y_TO_RGB (R/W) ;usually (1.000)*100h
10102012h/10132012h - Y2R_MULTIPLIER_V_TO_R (R/W) ;usually (1.402)*100h
10102014h/10132014h - Y2R_MULTIPLIER_V_TO_G (R/W) ;usually (0.714)*100h
10102016h/10132016h - Y2R_MULTIPLIER_U_TO_G (R/W) ;usually (0.344)*100h
10102018h/10132018h - Y2R_MULTIPLIER_U_TO_B (R/W) ;usually (1.772)*100h

      0-9   Multiplier for the YUV-to-RGB formula (unsigned, 0..3FFh)
      10-15 Unused (0)

1010201Ah/1013201Ah - Y2R_OFFSET_R (R/W) ;usually (-1.402)*1000h
1010201Ch/1013201Ch - Y2R_OFFSET_G (R/W) ;usually (+0.714+0.344)*1000h
1010201Eh/1013201Eh - Y2R_OFFSET_B (R/W) ;usually (-1.772)*1000h

      0-15  Offset for the YUV-to-RGB formula (signed, -8000h..+7FFFh)

10102020h/10132020h - Y2R_ALPHA (R/W)

      0-7   Alpha for RGBA output format 8888 and 5551 (the latter uses only bit7)
      8-31  Unused (0)

10102100h/10132100h - Y2R_DITHER0 (R/W)
10102108h/10132108h - Y2R_DITHER1 (R/W)
10102110h/10132110h - Y2R_DITHER2 (R/W)
10102118h/10132118h - Y2R_DITHER3 (R/W)

      0-31  Dither, R/W-mask 0000CCCCh

10302000h/10332000h - 80h byte window - Y2R_INPUT_Y (aka Luma) (W)
10302080h/10332080h - 80h byte window - Y2R_INPUT_U (aka Cb) (W)
10302100h/10332100h - 80h byte window - Y2R_INPUT_V (aka Cr) (W)
10302180h/10332180h - 80h byte window - Y2R_INPUT_YUYV (camera Y1,U,Y2,V) (W)
10302200h/10332200h - 80h byte window - Y2R_OUTPUT_RGBA (R)

      0-31  FIFO data

The FIFOs are mirrored to 80h-byte windows, however, the transfer blocks with 8 or 9 scanlines are much longer than that (so better it's better to use a fixed FIFO address, instead of increasing addresses in the 80h-byte windows)
For the optional swizzling feature, see
3DS Video Texture Swizzling

3DS Video L2B Registers (RGB-to-RGBA Converter) (New3DS)

10130000h - New3DS - L2B_0 - First RGB-to-RGBA converter (New3DS only)
10131000h - New3DS - L2B_1 - Second RGB-to-RGBA converter (New3DS only)

      10130000h/10131000h 4     L2B_CNT     Control  R/W  e3c00303h
      10130004h/10131004h 2     L2B_WIDTH   Width    R/W  03f8h
      10130006h/10131006h 2     L2B_HEIGHT  Height   R/W  03f8h
      10130020h/10131020h 4     L2B_ALPHA   Alpha    R/W  000000ffh
      10330000h/10331000h 1000h L2B_FIFO (IN and OUT, empty=data_abort) (R+W)

These registers appear to be called L2B, which might be short for Line-to-Block. They are similar to the YUV-to-RGBA converters, but merely converting from RGB-to-RGBA (and also allowing to convert between 5bit and 8bit color depths). And, they are always re-ordering the data from scanline format to swizzled texture format:
3DS Video Texture Swizzling
10130000h/10131000h - New3DS - L2B_CNT (R/W)

      0-1   Input RGBx Format            (0=8888, 1=8880, 2=5551, 3=5650)     (R/W)
      2-7   Unused (0)
      8-9   Output RGBA Format           (0=8888, 1=8880, 2=5551, 3=5650)     (R/W)
      10-21 Unused (0)
      22    Input DMA Enable             (0=Disable, 1=Enable CDMA 17h/19h)   (R/W)
      23    Output DMA Enable            (0=Disable, 1=Enable CDMA 18h/1Ah)   (R/W)
      24    Input DRQ                    (0=No, 1=DRQ) (write 1 to ack?)   (R/ack?)
      25    Output DRQ, 8th input line   (0=No, 1=DRQ) (write 1 to ack?)   (R/ack?)
      26-28 Unused (0)
      29    Interrupt upon DRQ(s)?       (0=Disable, 1=Enable IRQ 45h/46h)    (R/W)
      30    Interrupt upon Transfer done (0=Disable, 1=Enable IRQ 45h/46h)    (R/W)
      31    Start/Busy                   (0=Idle/Ready, 1=Start/Busy)         (R/W)

Send/Recv is done in units of 8 lines (unlike Y2R, which requires sending 9 lines in first block).
10130004h/10131004h - New3DS - L2B_WIDTH (R/W)
10130006h/10131006h - New3DS - L2B_HEIGHT (R/W)

      0-2   Unused (0)
      3-9   Width/Height in 8 pixel units (01h..7Fh=8..1016? pixels, or 00h=?)
      10-15 Unused (0)

10130020h/10131020h - New3DS - L2B_ALPHA (R/W)

      0-7   Alpha value for all pixels    (00h..FFh = Transparent..Solid)
      8-31  Unused (0)

Used as alpha for output format 8888 and 5551 (the latter uses only bit7 of the 8bit value).
Note: Any alpha values written to the input fifo are ignored, the alpha value is always taken from the alpha register, not from the incoming pixels.
10330000h/10331000h - New3DS - L2B_FIFO (R and W) (empty=data_abort)

      0-31  Pixel data

The FIFO is mirrored across a 1000h-byte window (but eight large scanlines may be larger than that, so it's better to used a fixed FIFO address instead of increasing addresses in that window).

3DS Video MVD Registers (Movie Decoder or so?) (New3DS)

Unknown. New3DS only. MVD might be short for Movie Decoder or so?
Unknown if there are any FIFOs and CDMA peripheral IDs... there are none known yet... maybe the thing does have it's own "DMA" hardware for direct memory access without needing CDMA?
10207000h - New3DS: Movie Decoder or so? Rockchip...? (ARM11 only)

      10207000h 4    R    67312398h  MVD Registers Chip ID?
      10207004h C4h  R/W  ffffffffh  MVD Registers
      102070C8h 4    R    07b4af80h  MVD Registers
      102070CCh 4    R/W  ffffffffh  MVD Registers
      102070D0h 4    -    00000000h  MVD Registers
      102070D4h 4    -    00000000h  MVD Registers
      102070D8h 4    R    c09a0000h  MVD Registers
      102070DCh 4    R/W  ffffffffh  MVD Registers
      102070E0h 4    -    00000000h  MVD Registers
      102070E4h 4    R    8516ffffh  MVD Registers
      102070E8h 4    -    00000000h  MVD Registers
      102070ECh 40h  R/W  ffffffffh  MVD Registers
      1020712Ch 4    -    00000000h  MVD Registers
      10207130h 4    -    00000000h  MVD Registers
      10207134h 4    -    00000000h  MVD Registers
      10207138h 4    -    00000000h  MVD Registers
      1020713Ch 44h  R/W  ffffffffh  MVD Registers
      10207180h 4    -    00000000h  MVD Registers
      10207184h 4    -    00000000h  MVD Registers
      10207188h 4    -    00000000h  MVD Registers
      1020718Ch 4    R    ffffffffh  MVD Registers
      10207190h 4    R    ff874780h  MVD Registers
      10207194h 6Ch  -    00000000h  Zerofilled
      10207200h E00h Mirrors of above 200h byte area

The ID value 67312398h appears to be known as "HW_ID" for linux/android "VPU SERVICES". Searching for that two strings gives this source code,

      http://git.jp.linux-rockchip.org/cgit/rk3288_r-box_android4.4.2_sdk/tree
      /kernel/arch/arm/mach-rockchip/vcodec_service.c

which defines VPU_DEC_ID_9190=6731h (the upper 16bit of the 67312398h value), so the "MVD" might be identical to that Rockchip hardware (whatever that is).

3DS Video LGY Registers (Legacy GBA/NDS Video to Framebuffer)

The LGYFB units are for forwarding GBA/NDS/DSi video to 3DS screens with optional scaling. The input comes directly from the GBA/NDS video controller, the output must be DMAed to memory.
That is, ARM11 must handle that memory transfers in background while running GBA/NDS/DSi software on ARM7/ARM9 side.
10110000h - LGYFB_0 (Legacy Framebuffer 0) (NDS bottom screen) (and GBA)
10111000h - LGYFB_1 (Legacy Framebuffer 1) (NDS top screen) (and GBA)

      10110000h/10111000h 4     LGYFB_CNT        R/W   mask:00019f37h  ;\
      10110004h/10111004h 4     LGYFB_SIZE       R/W   mask:01ff01ffh  ; Control
      10110008h/10111008h 4     LGYFB_IRQ_STAT   R/ack mask:01f80007h  ; Status
      1011000Ch/1011100Ch 4     LGYFB_IRQ_ENABLE R/W   mask:0007h      ;/
      10110020h/10111020h 4     LGYFB_ALPHA      R/W   mask:000000ffh  ;-Alpha
      101100F0h/101110F0h 4     LGYFB_UNKNOWN    R/W   mask:0000000fh  ;-Unknown?
      10110100h/10111100h 4     LGYFB_DITHER0    R/W   mask:0000cccch  ;\
      10110108h/10111108h 4     LGYFB_DITHER1    R/W   mask:0000cccch  ; Dither
      10110110h/10111110h 4     LGYFB_DITHER2    R/W   mask:0000cccch  ;
      10110118h/10111118h 4     LGYFB_DITHER3    R/W   mask:0000cccch  ;/
      10110200h/10111200h 4     LGYFB_V_LEN      R/W   mask:00000007h  ;\Vertical
      10110204h/10111204h 4     LGYFB_V_PATTERN  R/W   mask:000000ffh  ; Scaling
      10110240h/10111240h 4x30h LGYFB_V_ARRAY    R/W   mask:0000fff0h  ;/
      10110300h/10111300h 4     LGYFB_H_LEN      R/W   mask:00000007h  ;\Horizontal
      10110304h/10111304h 4     LGYFB_H_PATTERN  R/W   mask:000000ffh  ; Scaling
      10110340h/10111340h 4x30h LGYFB_H_ARRAY    R/W   mask:0000fff0h  ;/
      10310000h/10311000h 1000h LGYFB_FIFO       R     CDMA only       ;-Output

10110000h/10111000h - LGYFB_CNT (R/W)

      0     Start/Enable               (0=Stop, 1=Start)                      (R/W)
      1     Enable Vertical Scaling    (0=Disable, 1=Enable; via LGYFB_V_xxx) (R/W)
      2     Enable Horizontal Scaling  (0=Disable, 1=Enable; via LGYFB_H_xxx) (R/W)
      3     Unused (0)
      4     Brightness Dither Enable   (0=No, 1=Use LGYFB_DITHER0-3)          (R/W)
      5     Brightness Dither, too?    (as above, no Y2R-style Pulsation)     (R/W)
      6-7   Unused (0)
      8-9   Output Format RGBA      (0=8888, 1=8880, 2=5551, 3=5650)          (R/W)
      10-11 Output Clockwise Rotate (0=None, 1=90', 2=180', 3=270')           (R/W)
      12    Output Swizzle          (0=LinearFramebuf, 1=MortonSwizzleTexture)(R/W)
      13-14 Unused (0)
      15    Enable DMA              (0=Off, 1=Enable CDMA 0Dh/0Eh)            (R/W)
      16    Unknown... seems to have no visible effect for GBA/NDS (0=?, 1=?) (R/W)
      17-31 Unused (0)

Once when started, the transfer does auto-repeat each frame (although, that may hang with some/wrong settings; in that case it can help to toggle CNT.bit0 after DMAing the last block of each frame).
10110004h/10111004h - LGYFB_SIZE (R/W)

      0-8   Output Width (after scaling), minus 1  (0..1FFh = 1..512 pixels)  (R/W)
      9-15  Unused (0)
      16-24 Output Height (after scaling), minus 1 (0..1FFh = 1..512 pixels)  (R/W)
      25-31 Unused (0)

Caution: Must be written via 32bit STR (trying to use 16bit STRH will set BOTH halfwords to the same value).
10110008h/10111008h - LGYFB_IRQ_STAT (R/ack)

      0     First 8-Line Output Block (0=No, 1=Yes/IRQ) (write 1 to clear)  (R/ack)
      1     Next 8-Line Output Block  (0=No, 1=Yes/IRQ) (write 1 to clear)  (R/ack)
      2     Last Input? Line          (0=No, 1=Yes/IRQ) (write 1 to clear)  (R/ack)
      3-15  Unused (0)
      16-24 Output Block Line Number for IRQ bit0/1 (step 8)                    (R)
      25-31 Unused (0)

The Output Block Line Number can be used to compute the destination address for IRQ bit0/1. The initial line number upon reset is random/garbage (but gets valid after setting LGYFB_CNT.bit0).
Overrun can occur when not reading the output FIFO fast enough. After overrun, bit1 triggers only on each 2nd block, and bit2 won't trigger at all.
1011000Ch/1011100Ch - LGYFB_IRQ_ENABLE - ? (R/W)

      0     First 8-Line Output Block (0=Off, 1=Enable IRQ 4Ch/4Dh)           (R/W)
      1     8-Line Output Blocks      (0=Off, 1=Enable IRQ 4Ch/4Dh)           (R/W)
      2     Last Input? Line          (0=Off, 1=Enable IRQ 4Ch/4Dh?)          (R/W)
      3-31  Unused (0)

IRQ enable does also require LGYFB_CNT.bit0=1 and CFG11_TWLMODE_BOOT.bit15=1.
The end of frame irq occurs only if the blocks were actually transferred (via CDMA).
10110020h/10111020h - LGYFB_ALPHA - (R/W)

      0-7   Alpha value for all pixels    (00h..FFh = Transparent..Solid)
      8-31  Unused (0)

Used as alpha for output format 8888 and 5551 (the latter uses only bit7 of the 8bit value).
101100F0h/101110F0h - LGYFB_UNKNOWN (R/W)

      0-3   Unknown (initially 0Fh on reset)
      4-31  Unused (0)

Unknown. IRQ and DMA requests won't occur when using too small values. Without scaling values 01h..0Fh are working, with 2x vertical scaling only values 06h..0Fh are working.
10110100h/10111100h - LGYFB_DITHER0 (R/W)
10110108h/10111108h - LGYFB_DITHER1 (R/W)
10110110h/10111110h - LGYFB_DITHER2 (R/W)
10110118h/10111118h - LGYFB_DITHER3 (R/W)

      0-31  Dither alike Y2R, R/W-mask 0000CCCCh

10310000h/10311000h - LGYFB_FIFO (R)
Caution: This FIFO works via CDMA only (unlike most or all other FIFOs, it does trigger data abort when trying to read via CPU LDR opcodes; even if there is data in the FIFO).

      0-31  Output FIFO (contains 8 output lines per DMA request)

Use DMAWFP opcode (Wait for Peripheral) before reading an 8-line block. Or, wait for LGYFB_IRQ_STAT bit0/1, and then manually start the DMA for one 8-line block (the latter can be useful for transfers with clockwise rotate; where one may need to patch the destination address for each block).
For the optional swizzling feature, see
3DS Video Texture Swizzling

     ________________________________ Scaling Unit ________________________________

10110200h/10111200h - LGYFB_V_LEN - Vertical scaling (R/W)
10110300h/10111300h - LGYFB_H_LEN - Horizontal scaling (R/W)

      0-2   Batch size-1  (0..7 = 1..8 dst pixels) (using (1..8)*6 array entries)
      3-31  Unused (0)

Selects the number of pattern bits and array entries to be used (before repeating the scaling pattern).
10110204h/10111204h - LGYFB_V_PATTERN - Vertical scaling (R/W)
10110304h/10111304h - LGYFB_H_PATTERN - Horizontal scaling (R/W)

      0-7   Read a new src pixel before computing 1st..8th dst pixel (0=No, 1=Yes)
      8-31  Unused (0)

"The amount of set bits determine how many pixels are read each batch."
"Any bit indexes past LGYFB_x_LEN are ignored."
"This value is 8 bits, but it has to be written with a 32bit write."
Example values:

      Len Pattern    Effect
      1   xxxxxxx1b  No scaling    (1 input pixels --> 1 output pixels)
      8   11111111b  No scaling    (8 input pixels --> 8 output pixels)
      5   xxx01111b  Scale by 1.25 (4 input pixels --> 5 output pixels) ;NDS/DSi
      4   xxxx0111b  Scale by 1.33 (3 input pixels --> 4 output pixels)
      3   xxxxx011b  Scale by 1.5  (2 input pixels --> 3 output pixels)
      6   xx011011b  Scale by 1.5  (4 input pixels --> 6 output pixels) ;GBA
      3   xxxxx001b  Scale by 3    (1 input pixels --> 3 output pixels)
      2   xxxxxx01b  Scale by 2    (1 input pixels --> 2 output pixels)
      8   01010101b  Scale by 2    (4 input pixels --> 8 output pixels)
     GBA (240x160) scale by 1.5  = 3DS top screen (360x240)
     GBA (240x160) scale by 1.33 = 3DS bottom screen (320x213)
     NDS (256x192) scale by 1.25 = 3DS either screen (320x240)

10110240h/10111240h - LGYFB_V_ARRAY - Vertical scaling, 6x8 words (R/W)
10110340h/10111340h - LGYFB_H_ARRAY - Horizontal scaling, 6x8 words (R/W)
This array contains 6x8 words, used to compute up to 8 output pixels, with brightness multipliers for 6 input pixels each.

      0-3   Unused (0) (Nintendo writes 16bit to bit0-15, but bit0-3 are ignored)
      4-15  Brightness per source pixel (signed, -800h..+7FFh; 400h=full/max)
      16-31 Unused (0)

The sum of six input values should be 400h (the hardware does automatically clip results to min/max brightness; clipping can happen when mixing positive and negative values; with some of them getting multiplied with dark input pixels).
Note: Multipliers bigger than 400h are glitchy (value 7FFh somehow converts white pixels to dark gray).
Default Array for GBA screen (scale by 1.5) (240x160 to 360x240)
This is using Pattern=011011b and Length=6 (minus 1). The array entries are straight ahead, using pixels with full brightness, and merged pixels with half brightness:

      0000h,0000h,0000h,0000h,0000h,0000h, N/A , N/A  <-- for 1st input pixel
      0000h,0000h,0000h,0000h,0000h,0000h, N/A , N/A  <-- for 2nd input pixel
      0000h,2000h,4000h,0000h,2000h,4000h, N/A , N/A  <-- for 3rd input pixel
      4000h,2000h,0000h,4000h,2000h,0000h, N/A , N/A  <-- for 4th input pixel
      0000h,0000h,0000h,0000h,0000h,0000h, N/A , N/A  <-- for 5th input pixel
      0000h,0000h,0000h,0000h,0000h,0000h, N/A , N/A  <-- for 6th input pixel
        |     |     |     |     |     |
        |                             '-----------------> to 6th output pixel
        '-----------------------------------------------> to 1st output pixel

For whatever reason, this is scaling by 6:4 with 6 output pixels (instead of 3:2 with 3 output pixels). Unknown if it's faster that way, or if there's some other advantage.
Default Array for NDS/DSi screens (scale by 1.25) (256x192 to 320x240)
This is using Pattern=01111b and Length=5 (minus 1). The array entries contain positive and negative values, which might raise contrast between bright/dark pixels:

      0000h,004Eh,011Dh,01E3h,01C1h, N/A , N/A , N/A  <-- for 1st input pixel
      0000h,FCA5h,F8D0h,F69Dh,F873h, N/A , N/A , N/A  <-- for 2nd input pixel
      0000h,0D47h,1E35h,2F08h,3B6Fh, N/A , N/A , N/A  <-- for 3rd input pixel
      4000h,3B6Fh,2F08h,1E35h,0D47h, N/A , N/A , N/A  <-- for 4th input pixel
      0000h,F873h,F69Dh,F8D0h,FCA5h, N/A , N/A , N/A  <-- for 5th input pixel
      0000h,01C1h,01E3h,011Dh,004Eh, N/A , N/A , N/A  <-- for 6th input pixel
        |     |     |     |     |
        |                       '-----------------------> to 5th output pixel
        '-----------------------------------------------> to 1st output pixel

Weirdly, the values for 2nd-5th output pixel values sum up to 3FDDh/3FAAh (actually less, because the lower 4bit are ignored), making them a bit darker than 1st output pixel.

3DS Video Texture Swizzling

Texture Swizzling
Morton Swizzling, or Z-order Swizzling is done by reading source pixels from a scanline based bitmap in "Z-shaped" read-direction, and then storing that pixels at continous VRAM addresses.
In the drawing below, each "Z" represents 2x2 pixels (arranged as a "Z" shape, ie. upper-left, upper-right, lower-left, lower-right). On a larger scale, each 2x2 Z's are also forming a larger Z, and so on.

      Z/Z  /Z/Z
      .-' / .-'
      Z/Z/  Z/Z
          ..--'
      .--'
      Z/Z  /Z/Z
      .-' / .-'
      Z/Z/  Z/Z

This can improve cache hits for adjacent pixels. In a large bitmap, pixels in adjacent scanlines are always located in separate cache entries. With the swizzling, there is a better chance that they are in the same cache entry.
Addressing
The swizzling does interleave the x/y address bits. On the 3DS hardware, data is processed in units of 8 scanlines, so the interleave occurs on lower three x/y bits only. For example, for 256x256 pixel data:

      Scanline-based bitmap -->  YyyyyyyyXxxxxxxx
      Swizzled texture      -->  YyyyyXxxxxyxyxyx

Swizzling Hardware
The 3DS has some hardware for converting scanlines to swizzled textures:

      Y2R Registers (YUV-to-RGBA)
      L2B Registers (RGB-to-RGBA) (New3DS only)
      LGYFB Registers (GBA/NDS/DSi-to-3DS-Framebuffer)

Swizzling Examples
Examples for scanline pixels before/after swizzling:

      Linear scanlines, 16x8 pixels:                    Linear lines, 8x8 pixels:
      00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F   00 01 02 03 04 05 06 07
      10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F   08 09 0A 0B 0C 0D 0E 0F
      20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F   10 11 12 13 14 15 16 17
      30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F   18 19 1A 1B 1C 1D 1E 1F
      40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F   20 21 22 23 24 25 26 27
      50 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F   28 29 2A 2B 2C 2D 2E 2F
      60 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F   30 31 32 33 34 35 36 37
      70 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F   38 39 3A 3B 3C 3D 3E 3F
      Swizzled texture, 2 tiles:                        Swizzled texture, 1 tile:
      00 01 10 11 02 03 12 13  ;\                       00 01 08 09 02 03 0A 0B
      20 21 30 31 22 23 32 33  ;                        10 11 18 19 12 13 1A 1B
      04 05 14 15 06 07 16 17  ;                        04 05 0C 0D 06 07 0E 0F
      24 25 34 35 26 27 36 37  ; left tile              14 15 1C 1D 16 17 1E 1F
      40 41 50 51 42 43 52 53  ;                        20 21 28 29 22 23 2A 2B
      60 61 70 71 62 63 72 73  :                        30 31 38 39 32 33 3A 3B
      44 45 54 55 46 47 56 57  ;                        24 25 2C 2D 26 27 2E 2F
      64 65 74 75 66 67 76 77  ;/                       34 35 3C 3D 36 37 3E 3F
      08 09 18 19 0A 0B 1A 1B  ;\
      28 29 38 39 2A 2B 3A 3B  ;
      0C 0D 1C 1D 0E 0F 1E 1F  ;
      2C 2D 3C 3D 2E 2F 3E 3F  ; right tile
      48 49 58 59 4A 4B 5A 5B  ;
      68 69 78 79 6A 6B 7A 7B  :
      4C 4D 5C 5D 4E 4F 5E 5F  ;
      6C 6D 7C 7D 6E 6F 7E 7F  ;/

Note: Z-order refers to the shape of the letter "Z", not to be confused with Z-axis, and not to be confused with the zigzag-order that is used in JPEGs.

3DS Sound and Microphone

3DS Sound File Formats
3DS Files - Sound Archive (CSAR Format)
3DS Files - Sound SEQ (CSEQ Format)
3DS Files - Sound WSD (CWSD Format)
3DS Files - Sound Bank (CBNK Format)
3DS Files - Sound Wave Archive (CWAR Format)
3DS Files - Sound Wave Data (CWAV Format)
3DS Files - Sound Wave Streams (CSTM Format)
3DS Files - Sound Group (CGRP Format)
3DS Files - Sound IDs (CSID Format)
Note: The sound files resemble the older SDAT format used on NDS/DSi (many of the unknown entries are probably similar to those older files).
Additionally, .aac files are probably AAC audio. And .cdc files contain DSP program code.
3DS Files - Sound DSP Binary (DSP1 aka .cdc)

     ________________________________ DSP Registers _______________________________

Reportedly 10141220h - CFG11_CODEC_CNT also has a DSP related bit?
10203000h Teak DSP Registers (ARM11 only)
These registers are disabled by default (always zero), use CFG11_DSP_CNT (Port 10141230h) to enable them.

      10203000h 2    DSP_PDATA
      10203004h 2    DSP_PADR
      10203008h 2    DSP_PCFG
      1020300Ch 2    DSP_PSTS
      10203010h 2    DSP_PSEM
      10203014h 2    DSP_PMASK
      10203018h 2    DSP_PCLEAR
      1020301Ch 2    DSP_SEM
      10203020h 2    DSP_CMD0
      10203024h 2    DSP_REP0
      10203028h 2    DSP_CMD1
      1020302Ch 2    DSP_REP1
      10203030h 2    DSP_CMD2
      10203034h 2    DSP_REP2
      10203040h FC0h Mirrors of above 40h-byte area
      10203200h 40h  Reportedly "LCD", but actually it's just one of above mirrors

These are same as on DSi.
DSi XpertTeak (DSP)
3DS software is commonly using the DSP to play music recordings in AAC format, and reportedly there is something called DSP-ADPCM (maybe something similar to IMA-ADPCM)?

     _______________________________ CSND Registers _______________________________

The sound hardware works very similar to NDS sound, see there for details about PCM, IMA-ADPCM and PSG formats.
DS Sound
Differences are twice as many sound channels, some moved control bits, and simplified volume control (without sound/panning/master volumes).
Unknown if/where BIAS exists on 3DS?
10103000h - Sound Control (R/W)

      0-15   CSND Master Volume (0..8000h) (8001h..FFFFh=replaced by 8000h) (R/W)
      16     Disable sound output           (0=Enable, 1=Mute)              (R/W)
      17-29  Unused? (0)
      30     Dissonant sound??              (0=Dissonant, 1=Normal)         (R/W)
      31     Makes some register/bits R/W   (0=No, 1=Yes)                   (R/W)

When bit31=1:

      10103400h+(N*20h).bit15   becomes R/W
      1010340Ch+(N*20h).bit31-2 becomes R/W
      10103800h+(N*10h).bit15   becomes R/W
      1010380Ch+(N*10h).bit31-0 becomes R/W

     ___________________________ CSND Channel Registers ___________________________

10103400h+(N*20h) - Sound Channel 0-31: Control (parts W and R/W)

      0-2    Wave Duty   (0..7) ;HIGH=(N+1)*12.5%, LOW=(7-N)*12.5% (PSG only) (R/W)
      3-5    Unused (0)
      6      Linear interpolation on each two samples (0=Disable, 1=Enable)   (R/W)
      7      Hold   (0=Normal, 1=Hold last sample after one-shot sound)       (R/W)
      8-9    Unused (0)
      10-11  Repeat (0=Manual, 1=Loop Infinite, 2=One-shot, 3=Same as 1?)     (R/W)
      12-13  Format (0=PCM8, 1=PCM16, 2=IMA-ADPCM, 3=PSG/Noise)               (R/W)
      14     Pause DMA or so? (0=Pause?, 1=Normal)  ;no effect on PSG?!       (R/W)
      15     Start/Status (0=Stop, 1=Start/Busy)    ;need 10103000h.bit31     (R/W)
      16-31  Sample Rate (0..FFBEh; 0=Slowest, FFBEh=Fastest) (FFBFh..=Hangs)   (W)

PSG/Noise: Rectangular waves are supported on channel 8-13, noise on channel 14-15. Rectangular wave Duty is same as for NDS (but 32 samples long instead of 8 samples).
Sample rate is reportedly 4x higher than NDS:

      value = 67.027964MHz / samplerate
      uh, that value is NOT negative??? apparently wrong.
      XXX but what is NOISE frequency?

10103404h+(N*20h) - Sound Channel 0-31: Output Volume (R/W)

      0-15  Volume Right (0..8000h)  ;\writing values 8001h..FFFFh is
      16-31 Volume Left  (0..8000h)  ;/automatically changed to 8000h

10103408h+(N*20h) - Sound Channel 0-31: Capture Volume (R/W)

      0-15  Capture 0 volume (right?) (0..8000h) ;\writing 8001h..FFFFh gets
      16-31 Capture 1 volume (left?)  (0..8000h) ;/automatically changed to 8000h

1010340Ch+(N*20h) - Sound Channel 0-31: Start Address (R/W) (Bit0-1: W)
10103414h+(N*20h) - Sound Channel 0-31: Loop Restart Address (W)

      0-31  Physical Memory Address (unused for PSG/noise)

The R/W-ability is a mess: Start.bit2-31 are R/W (if enabled in 10103000h.bit31). Start.bit0-1 do also exist, but are write-only. Restart.bit0-31 are write-only.
10103410h+(N*20h) - Sound Channel 0-31: Total Size (W)

      0-26   Size in bytes (0..7FFFFFFh) (unused in manual mode)
      27-31  Unknown/Unused (0)

The size value is for the total size from Start to End (or Loop End if looped). The total size (and size of looped part) semm to be required to be at least 10h. Hardware behaves quirky if the size of the looped part (total-(restart-start)) is odd and/or(?) less than 10h. And, the quirkyness can differ depending on whether CNT.bit10-11 is 1 or 3 (which is otherwise same).
10103418h+(N*20h) - Sound Channel 0-31: Start IMA-ADPCM state (W)

      0-15   Initial PCM16 Value (Pcm16bit = -7FFFh..+7FFF) (not -8000h)
      16-22  Initial Table Index Value (Index = 0..88)
      23     Uh, reportedly MSB of above 7bit value ???
      ..     Unknown/Unused (0)

Equivalent to the IMA-ADPCM header from NDS samples (but, unlike as NDS, the header must be manually written here; instead being located in the first four sample bytes).
1010341Ch+(N*20h) - Sound Channel 0-31: Loop Restart IMA-ADPCM state (W)

      0-15   Restart PCM16 Value (Pcm16bit = -7FFFh..+7FFF) (not -8000h)
      16-22  Restart Table Index Value (Index = 0..88)
      23     Uh, reportedly MSB of above 7bit value ???
      ..     Unknown/Unused (0)
      31     Reportedly ADPCM state reload at Loop Restart (1=Enable)

Allows to force the ADPCM state to the correct (pre-calculated) value upon looping (or, with bit31=0, samples could drift if the last sample doesn't end with exact same state as the first loop sample)...?
Uh, that's both weird... on NDS, the hardware did simply latch the correct value automatically... is that really left unsupported on 3DS?

     ___________________________ CSND Capture Registers ___________________________

These are probably for left/right channel...
Maybe Capture 0 Left, and Capture 1 right?
10103800h+(N*10h) - Sound Capture 0-1: Control (R/W)

      0      Capture Repeat        (0=Loop, 1=One-shot)
      1      Capture Format        (0=PCM16, 1=PCM8)
      2      Unknown ...? maybe something similar as on NDS
      2-14   Unused (0)
      15     Capture Start/Status  (0=Stop, 1=Start/Busy)  ;need 10103000h.bit31
      16-31  Unused (0)

There seems to be some extra delay at begin or end of capture: For one-shot, the bit15=1 duration should depend on rate and length (but takes a bit longer than it should).
10103804h+(N*10h) - Sound Capture 0-1: Sample Rate (W)

      0-15   Sample Rate (0..FFBEh; 0=Slowest, FFBEh=Fastest) (FFBFh..FFFFh=Hangs)
      16-31  Unknown/unused (0)

1010380Ch+(N*10h) - Sound Capture 0-1: Length (W)

      0-23   Length (in bytes) (1..FFFFFFh) (and oddly: 0=Same as 4)
      24-31  Unknown/unused (0)

1010380Ch+(N*10h) - Sound Capture 0-1: Address (R/W)

      0-31   Address (in bytes) <--- This is R/W only if enabled in 10103000h.bit31

Capture works even if address and size are unaligned (even so for PCM16).

     _______________________________ CODEC Registers ______________________________

10145000h - CODEC_SNDEXCNT, reportedly "Empty" uh? (R/W)

      0-5   DSP sound volume (00h..3Fh) (R/W)
      6-11  GBA sound volume (00h..3Fh) (R/W)
      12    Enable Microphone timing
      13    Sound/Microphone I2S frequency (0=32.73 kHz, 1=47.61 kHz)
      14    Unknown (maybe Mute, alike DSi's SNDEXCNT)
      15    Enable Microphone and Teak BTDMP timing and GBA sound
      16-28 Unused (0)
      29    Unknown                   (R/W)
      30    Unknown, disonnant sound? (R/W)
      31    Master Enable Microphone (and Sound?)

Microphone requires bit31 set, and also one or both of bit15/bit12 set.
Teak BTDMP timing requires bit15 set (and is also affected by bit13).
GBA sound requires bit15 set, and nonzero volume in bit6-11.
Maybe some further bits here resemble DSi's SNDEXCNT...?

     ________________________________ MIC Registers _______________________________

MIC Registers

      10162000h 2  REG_MIC_CNT  Microphone Control
      10162004h 4  REG_MIC_DATA Microphone Data

These are about same as for DSi.
DSi Microphone and SoundExt
The microphone must be unmuted in touchscreen TSC registers.
The microphone must be enabled in Port 10145000h.
Microphone triggers CDMA 00h (requires Port 1014010Ch, CFG11_CDMA_CNT.bit0=1).

3DS Cartridge Registers

Gamecard related CONFIG9 Registers

      1000000Ch 2   CFG9_CARD_CTL           NTRCARD/CTRCARD/SPI controller select
      10000010h 1   CFG9_CARD_POWER         Power On/Off/Reset and Eject detect
      10000012h 2   CFG9_CARD_INSERT_DELAY  Cart insert detection delay
      10000014h 2   CFG9_CARD_PWROFF_DELAY  Cart power off delay

3DS Config - CONFIG9 Registers

     ___________________________ 3DS Cartridge Protocol ___________________________

Cartridge detection is done using unencrypted 8-byte NTRCARD commands, 3DS cartridges have ChipID.bit28=1, if so, command 3Eh is used to switch to 16-byte CTRCARD mode.
Of these 16-byte commands, the first command/reply (82h) is unencrypted, used to receive the header with an AES-encrypted encryption constant. The next command/reply (83h) is encrypted using that constant, used to send a random value. The following commands are encrypted using a combination of the original constant and the random value.

      Command                          Data  Expl.
      9F00000000000000                 2000h Dummy
      71C93FE9BB0A3B18                 0     Unknown/dummy (hardcoded constant)
      9000000000000000                 4     Get Chip ID, response=9000FEC2
      9000000000000000                 4     Get Chip ID, response=9000FEC2
      A000000000000000                 4     Get Chip Type, response=00000000
      3E00000000000000                 0     Enter 16-byte command mode
      82000000000000000000000000000000 200h  Get header/seed (NCSD[1000h..11FFh])
      8300000000000000rrrrrrrrrrrrrrrr 0     Change Seed (to random)
      A200000000000000rrrrrrrrrrrrrrrr 4     Get Chip ID, response=9000FEC2
      A300000000000000rrrrrrrrrrrrrrrr 4     Get Chip Type, response=00000000
      C500000000000000rrrrrrrrrrrrrrrr 0     Unknown Watchdog?
      A200000000000000rrrrrrrrrrrrrrrr 4     Get Chip ID, response=9000FEC2
      A200000000000000rrrrrrrrrrrrrrrr 4     Get Chip ID, response=9000FEC2
      A200000000000000rrrrrrrrrrrrrrrr 4     Get Chip ID, response=9000FEC2
      A200000000000000rrrrrrrrrrrrrrrr 4     Get Chip ID, response=9000FEC2
      A200000000000000rrrrrrrrrrrrrrrr 4     Get Chip ID, response=9000FEC2
      BF000000000000000000000000000000 200h  Read address 0 (NCSD[0..1FFh])
      BF000000000040000000000000000000 200h  Read address 4000h (maybe partition?)
      C6000000000000000000000000000000 40h   Get Unique ID (on-chip PROM)
      BFaaaaaaaaaaaaaa0000000000000000 200h  Read address aaa...
      C5000000000000000000000000000000 0     Unknown Watchdog (each 10,000 reads)
      BFaaaaaaaaaaaaaa0000000000000000 200h  Read address aaa...

On a lower level, the NTRCARD commands are working about as on NDS/DSi (with hardcoded gaps between command and data). The CTRCARD commands are sending a status byte instead of gaps (00h bytes when not ready, 01h when ready for data transfer; the 3DS hardware does automatically wait for that status byte before transferring data blocks). The data block is reportedly followed by a standard CRC32 value across unencrypted data. However, cartridges do only seem to output correct CRC's for command 82h/BFh. And, even then, the CRC doesn't actually look like a standard CRC32, or maybe the CRC gets garbled by encryption or status bytes?
The PROM is used for online games, it contains a 16-byte hex number (followed by 30h-byte FFh-filled area).
Some cards do also have writeable NAND instead of ROM. The NAND is also accessed via CTRCARD0 registers (not CTRCARD1), the NAND commands are still unknown.

     __________________________ 3DS Cartridge Encryption __________________________

The encryption seed is initialized as follows:

      CardType = (ReplyFromCommandA0h AND 00000003h)
      send CTRCARD command 82h                      ;-receive NCSD[1000h..11FFh]
      AES.KEYX = as set by bootrom, keyslot 3Bh     ;\
      AES.KEYY = NCSD[1000h..100Fh]                 ; decrypt seed via AES-CCM
      AES.MAC  = NCSD[1020h..102Fh]                 ; (use big-endian input,
      AES.IV   = NCSD[1030h..103Bh]                 ; and little-endian output)
      if CardType=3 then AES.KEY = zerofilled       ;  <--dev card (keyslot 11h)
      AES.DATA.IN  = NCSD[1010h..101Fh]             ;
      ctrcard_seed[00h..0Fh] = AES.DATA.OUT         ;/
      CTRCARD_SECSEED = ctrcard_seed                ;\
      CTRCARD_SECCNT = CardType*100h+8004h          ; apply fixed seed
      wait until CTRCARD_SECCNT.bit14=1             ;/
      random64bit = whatever, can be zero, or same as fixed seed, or random
         cmdRand1 = REG_PRNG[0];
         cmdRand2 = REG_PRNG[4];
      send CTRCARD command 83h + random64bit        ;-send random64bit to card
      ctrcard_seed[00h..07h] = random64bit          ;-change LSBs of fixed seed
      CTRCARD_SECSEED = ctrcard_seed                ;\
      CTRCARD_SECCNT = CardType*100h+8004h          ; apply random seed
      wait until CTRCARD_SECCNT.bit14=1             ;/
      send further CTRCARD commands...              ;-get chip id, read data, etc.

The inner workings of the encryption hardware are unknown, it does probably contain AES hardware with some built-in secret key/iv values. Cart dumping is possible using the 3DS console hardware, there are also "sky3DS" flashcards that can run pirate copies on 3DS consoles without needing exploits, but that's kinda useless and works only for RSA signed official titles with region lock (the game selection is done via buttons on the cartridge instead of file menu).

     _____________________________ NTRCARD Registers ______________________________

NTRCARD Registers (ARM9/ARM11)
These registers are same as the old NDS Cartridge registers, see
DS Cartridge I/O Ports

      10164000h 2  REG_NTRCARD_MCNT    ;40001A0h 2  Gamecard ROM and SPI Control
      10164002h 2  REG_NTRCARD_MDATA   ;40001A2h 2  Gamecard SPI Bus Data/Strobe
      10164004h 4  REG_NTRCARD_ROMCNT  ;40001A4h 4  Gamecard bus timing/control
      10164008h 8  REG_NTRCARD_CMD     ;40001A8h 8  Gamecard bus 8-byte command out
      10164010h 4  REG_NTRCARD_SEEDX_L ;40001B0h 4  Gamecard Encryption Seed 0 Low
      10164014h 4  REG_NTRCARD_SEEDY_L ;40001B4h 4  Gamecard Encryption Seed 1 Low
      10164018h 1  REG_NTRCARD_SEEDX_H ;40001B8h 2  Gamecard Encryption Seed 0 High
      1016401Ah 1  REG_NTRCARD_SEEDY_H ;40001BAh 2  Gamecard Encryption Seed 1 High
      1016401Ch 4  REG_NTRCARD_FIFO    ;4100010h 4  Gamecard bus 4-byte Data In (R)

These registers are usually used on ARM9 side. However, they are mapped to both ARM11/ARM9, and do support IRQ/DMA on ARM11/ARM9 side (unlike most other registers in that area, which support IRQ/DMA on ARM11 side only).
Note: ARM11-side CDMA 01h requires Port 1014010Ch, CFG11_CDMA_CNT.bit1=1.

     _____________________________ CTRCARD Registers ______________________________

CTRCARD Registers (ARM9 only)

     10004000h - CTRCARD0 - normal cartridge access
     10005000h - CTRCARD1 - unknown purpose, not used for ROM cards, nor NAND cards
      10004000h/10005000h 4   CTRCARD_CNT
      10004004h/10005004h 4   CTRCARD_BLKCNT
      10004008h/10005008h 4   CTRCARD_SECCNT    ;varies for CARD0/CARD1
      1000400Ch/1000500Ch 4   CTRCARD_LOCK
      10004010h/10005010h 4   CTRCARD_SECSEED      FIFO!!!!!
      10004020h/10005020h 16  CTRCARD_CMD
      10004030h/10005030h 4   CTRCARD_FIFO

10004000h/10005000h - CTRCARD_CNT

      0-4   Timeout (0-16=1ms,2ms,4ms,8ms,..,64s; 17-31=64s, too; def=12=4s)  (R/W)
      5     Timeout Error      (0=Okay, 1=Error) (write 0 to ack)           (R/ack)
      6     Timeout Enable     (0=Disable, 1=Enable)                          (R/W)
      7     Unused (0)
      8     CRC Error          (0=Okay, 1=Error) (write 0 to ack)           (R/ack)
      9     CRC Enable         (0=Disable, 1=Enable) (works for cmd 82h/BFh)  (R/W)
      10-14 Unused (0)
      15    DMA Enable         (0=Disable, 1=Enable DMA DRQs, each 8 words)   (R/W)
      16-19 Data Block size    (0-8=0,4,16,64,512,1K,2K,4K,8K; 9-15=8K, too)  (R/W)
      20-23 Unused (0)
      24-26 Transfer Clock     (0-5=67MHz div 4,5,6,8,10,16; 6-7=div16, too)  (R/W)
      27    Data-Word status   (0=Busy, 1=Ready/DRQ)                            (R)
      28    Reset Pin          (0=Low/Reset, 1=High/Release) (SET-ONCE)       (R/W)
      29    Transfer Direction (0=Read, 1=Write)                              (R/W)
      30    Interrupt Enable   (0=Disable, 1=Enable) (ARM9 IF.bit23/24)       (R/W)
      31    Start              (0=Idle, 1=Start/Busy)                         (R/W)

With the above Transfer Clock settings, the clock (per byte) can range from 16.7MHz downto 4.2MHz.
Once reset pin is set high, it cannot be changed until controller is reset (which can be done CFG9_CARD_POWER). Setting bit28 does work only when writing bit31=0.
10004004h/10005004h - CTRCARD_BLKCNT (R or R/W)

      0-14  Number of data blocks to read, minus 1   (0..7FFFh=1..8000h)      (R/W)
      15    Unused (0)
      16-28 Number of data blocks to write, minus 1  (0..1FFFh=1..2000h)      (R/W)
      29-31 Unused (0)

10004008h/10005008h - CTRCARD_SECCNT (R or R/W)
For CARD0 (10004008h): (R/W mask 0307h, with readonly mask 4000h)

      0-1   Crypto Mode   (0=Normal, 1=Unknown, 2=Ignore SEED, 3=same as 0)   (R/W)
      2     Crypto Enable (0=Disable, 1=Enable)                               (R/W)
      3-7   Unused (0)
      8-9   Crypto Key index      (0..3, from A0h command) (3=debug)          (R/W)
      10-14 Unused (0)
      14    Crypto Apply Ready    (0=Busy, 1=Ready)                             (R)
      15    Crypto Apply Seed/Key (0=No, 1=Update Seed, works only if bit2=1)   (W)
      16-31 Unused (0)

For CARD1 (10005008h): (R/W mask 9300h, without readonly mask)

      0-7   Unused (0)
      8-9   Key index (?)                                                     (R/W)
      10-11 Unused (0)
      12    unknown... ?                                                      (R/W)
      13-14 Unused (0)
      15    unknown... ?                                                      (R/W)
      16-31 Unused (0)

1000400Ch/1000500Ch - CTRCARD_LOCK (R or R/W)

      0     Write-protect CNT.bit28, SECCNT.bit0-2 (0=No, 1=Lock) (SET-ONCE)  (R/W)
      1-31  Unused (0)

10004010h/10005010h - CTRCARD_SECSEED (W)

      0-31  Encryption Seed, 4-word FIFO (16 bytes)

To apply the four most recent words written to SECSEED, write SECCNT.bit15=1, then wait for SECCNT.bit14=1.
The seed is usually updated twice: Once after command 82h (using four seed words from the cart header), and once after command 83h (with two seed words changed to random values).
10004020h/10005020h - CTRCARD_CMD (W)

      0-127 Command (128bit, aka 16 bytes, little endian, transferred MSB first)

10004030h/10005030h - CTRCARD_FIFO (R) (maybe also for write-direction?)

      0-31  Data (from 8 word FIFO)

     _____________________________ SPI CARD Registers _____________________________

SPI FLASH cartridge savedata is accessed via SPI_CARD registers, see:
3DS SPI Registers

3DS Interrupts and Timers

ARM9
3DS ARM9 Interrupts
3DS ARM9 Timers
ARM11
3DS ARM11 Interrupts
ARM11 MPCore Private Memory Region Register Summary
ARM11 MPCore - Snoop Control Unit (SCU)
ARM11 MPCore - Timer and Watchdog
ARM11 MPCore - Interrupt Configuration
ARM11 MPCore - Interrupt Handling
ARM11 MPCore Distributed Interrupt Controller (Blurb)

3DS ARM9 Interrupts

ARM9 Interrupts (ARM9 only)
Mostly same as GBA/NDS/DSi, but without IME (only CPSR irq enable), and without IE2/IF2, and with changed IRQ bits:
10001000h - IRQ_IE - ARM9 Interrupt Enable
10001004h - IRQ_IF - ARM9 Interrupt Flags

      0-7   NDMA 0..7                                            (Port 10002000h)
      8-11  TIMER 0..3                                           (Port 10003000h)
      12    PXI_SYNC        ;aka IPC Sync                        (Port 10008000h)
      13    PXI_NOT_FULL    ;aka IPC Send FIFO Empty      ?      (Port 10008000h)
      14    PXI_NOT_EMPTY   ;aka IPC Recv FIFO Not Empty  ?      (Port 10008000h)
      15    AES                                                  (Port 10009000h)
      16    SDMMC controller (eMMC and SD/MMC slot)              (Port 10006000h)
      17    SDMMC sdio.irq pin?
      18    SDxx controller?    ;maybe this is SDIO wifi ? or unused 2nd SDMMC?
      19    SDxx sdio.irq pin?
      20    DEBUG_RECV      ;uh?                                 (?)
      21    DEBUG_SEND      ;uh?                                 (?)
      22    RSA                                                  (Port 1000B000h)
      23    CTRCARD0        and/or SPI_CARD ?                    (Port 10004000h)
      24    CTRCARD1                                            (Port 10005000h?)
      25    CGC     Gamecard power off  (CFG9_CARD_PWROFF_DELAY) (Port 10000010h)
      26    CGC_DET Gamecard insert     (CFG9_CARD_INSERT_DELAY) (Port 10000010h)
      27    NTRCARD (used by ARM9, although it's ARM11/ARM9)     (Port 10164000h)
      28    XDMA Event 0..4 (five events sharing one IRQ)        (Port 1000C000h)
      29    XDMA Faulting (eg. CCR=0, or event>11)               (Port 1000C000h)
      30-31 Unused (always 0)

3DS ARM9 Timers

Timers (ARM9 only)
10003000h ARM9
Same as GBA/NDS/DSi, except, reportedly faster & with stunning accuracy:

      "timers run at a frequency of 67,027,964.0 +/- 2^(-32) Hz"

which would be an estimated error of about +/- 1 cycle per century, or +/- 1 second per a few billions of years.
GBA Timers

3DS ARM11 Interrupts

Private Software Interrupts (can be different for each CPU)

      IRQ    Listener      Description
      00h                  MPCore software IRQ, not configured
      01h                  MPCore software IRQ, used by BOOT11 to kickstart Core1
      02h-03h              MPCore software IRQ, seem to be unused
      04h    Kernel        MPCore software IRQ, used to manage performance counter
      05h    Kernel        MPCore software IRQ, does apparently nothing
      06h    Kernel        MPCore software IRQ, extensively used by
                             KernelSetState (and contains most of the actual
                             code of the latter)
      07h    Kernel        MPCore software IRQ, see KCacheMaintenanceInterruptEvent
      08h    Kernel        MPCore software IRQ, used for scheduling
      09h    Kernel        MPCore software IRQ, used when handling
                             exceptions that require termination of a thread or
                             a process, and in some cases by
                             svcSetDebugThreadContext, to store VFP registers
                             in the thread's register storage.
      0Ah    Kernel        TLB operations IRQ, see KTLBOperationsInterruptEvent
      0Bh-0Eh              MPCore software IRQ, not configured
      0Fh    dmnt/debugger MPCore software IRQ, used to abstract FIQ (debug),
                             this interrupt is never sent to New3DS core2/core3

Private Timer Interrupts (has separate timers for each CPU)

      10h-1Ch              Hmmmm, these do NOT EXIST (?) in interrupt controller?
      1Dh    Kernel        MPCore Timer0 (Port 17E00600h)
      1Eh    Kernel        MPCore Timer1 (Port 17E00620h) (3DS used on "core 1")
      1Fh                  MPCore Legacy "nIRQ" pin (is that used in 3DS?)

Hardware Interrupts (can be used for all CPUs that are selected as Target)

      20h-23h -           Unused?
      24h     spi?        SPI_BUS2 (unused)               (Port 10143000h)
      25h-27h -           Unused?
      28h     gsp, TwlBg  PSC0 (GPU_MEMFILL 0)                 (Port 10400010h)
      29h     gsp, TwlBg  PSC1 (GPU_MEMFILL 1)                 (Port 10400020h)
      2Ah     gsp, TwlBg  PDC0 (GPU H/V-IRQ for top screen)    (Port 10400400h)
      2Bh     gsp, TwlBg  PDC1 (GPU H/V-IRQ for bottom screen) (Port 10400500h)
      2Ch     gsp, TwlBg  PPF  (GPU_MEMCOPY)                   (Port 10400C00h)
      2Dh     gsp, TwlBg  P3D  (GPUREG_IRQ_CMP/REQ)            (Port 10401040h)
      2Eh-2Fh -           Unused?
      30h-38h Kernel      Old CDMA Event 0..8 (nine events with separate IRQs)
      39h     Kernel      Old CDMA Faulting (eg. CCR=0, or event>15)
      3Ah     Kernel      New CDMA Event 0..31 (32 events sharing one IRQ) ;\New3DS
      3Bh     Kernel      New CDMA Faulting (eg. CCR=0)                    ;/
      3Ch-3Fh -           Unused?
      40h     nwm         WIFI SDIO Controller            (Port 10122000h)
      41h     nwm         WIFI SDIO IRQ Pin
      42h     nwm_dev?    Debug WIFI SDIO Controller      (Port 10100000h?)
      43h     -           Unused? Or maybe Debug WIFI SDIO IRQ Pin for above?
      44h     -           NTRCARD                         (Port 10164000h)
      45h     mvd         L2B_0 (First RGB-to-RGBA Converter)  (10130000h) ;\New3DS
      46h     mvd         L2B_1 (Second RGB-to-RGBA Converter) (10131000h) ;/
      47h     -           Unused?
      48h     camera      Camera Bus 0 (DSi cameras)      (Port 10120000h)
      49h     camera      Camera Bus 1 (left-eye)         (Port 10121000h)
      4Ah     dsp         ...probably Teak DSP... ?      (maybe 10203000h)
      4Bh     camera      Y2R_0 (First YUV-to-RGBA Converter)  (10102000h)
      4Ch     TwlBg       LGYFB_0 Legacy GBA/NDS Video    (Port 10110000h)
      4Dh     TwlBg       LGYFB_1 Legacy GBA/NDS Video    (Port 10111000h)
      4Eh     mvd         Y2R_1 (Second YUV-to-RGBA Converter) (10132000h) ;\New3DS
      4Fh     mvd         MVD Registers                   (Port 10207000h) ;/
      50h     pxi, TwlBg  PXI_SYNC.bit29 from ARM9 (commonly used)
      51h     pxi, TwlBg  PXI_SYNC.bit30 from ARM9 (rarely used)
      52h     pxi, TwlBg  PXI Send Fifo Empty
      53h     pxi, TwlBg  PXI Receive Fifo Not Empty
      54h     i2c, TwlBg  I2C_BUS0 (DSi devices)          (Port 10161000h)
      55h     i2c, TwlBg  I2C_BUS1 (3DS devices)          (Port 10144000h)
      56h     spi, TwlBg  SPI_BUS0 (Pwrman,WifiFlash,Tsc) (Port 10160000h)
      57h     spi, TwlBg  SPI_BUS1 (Tsc)                  (Port 10142000h)
      58h     Kernel      CFG11_MPCORE_CLKCNT (clk change)(Port 10141300h) ;-New3DS
      59h     TwlBg       CFG11_TWLMODE_SLEEP             (Port 10141104h)
      5Ah     mic         Microphone maybe?              (maybe 10162000h)
      5Bh     -           HID PAD Controller Buttons      (Port 10146000h)
      5Ch     i2c, TwlBg  I2C_BUS2 (3DS extra gimmicks)   (Port 10148000h)
      5Dh-5Eh -           Unused?
      5Fh     -           NDS-Wifi Registers (aka MP)     (Port 10170000h)
      60h     gpio, TwlBg GPIO_DATA0.bit2?   Shell opened
      61h     -           Unused?
      62h     gpio, TwlBg GPIO_DATA0.bit2?   Shell closed
      63h     gpio, TwlBg GPIO_DATA0.bit1    Touchscreen Pen Down (if enabled)
      64h     gpio, TwlBg GPIO_DATA1.bit0    Headphone jack plugged in/out
      65h     -           Unused?
      66h     gpio, TwlBg GPIO_DATA1.bit1    ?
      67h     -           Unused?
      68h     gpio, TwlBg GPIO_DATA3.bit0    C-stick Interrupt (New3DS)
      69h     gpio, TwlBg GPIO_DATA3.bit1    IrDA Interrupt
      6Ah     gpio, TwlBg GPIO_DATA3.bit2    Gyro Interrupt
      6Bh     gpio, TwlBg GPIO_DATA3.bit3    ?
      6Ch     gpio, TwlBg GPIO_DATA3.bit4    ?
      6Dh     gpio, TwlBg GPIO_DATA3.bit5    ?
      6Eh     gpio, TwlBg GPIO_DATA3.bit6    ?
      6Fh     gpio, TwlBg GPIO_DATA3.bit7    ?
      70h     gpio, TwlBg GPIO_DATA3.bit8    TSC[67h:2Bh] (Headphone connect)
      71h     gpio, TwlBg GPIO_DATA3.bit9    MCU Interrupt (MCU[10h-1Fh])
      72h     gpio, TwlBg GPIO_DATA3.bit10   NFC Interrupt (New3DS)
      73h     TwlBg       GPIO_DATA3.bit11   ??
      74h     ?           CGC Gamecard power off     (CFG9_CARD_PWROFF_DELAY)
      75h     ?           CGC Gamecard insert switch (CFG9_CARD_INSERT_DELAY)
      76h     -           L2C Level 2 Cache Controller    (Port 17E10000h)   New3DS
      77h     -           Unused?
      78h     Kernel      CPU0 cp15 Performance monitor count (any) overflow
      79h     Kernel      CPU1 cp15 Performance monitor count (any) overflow
      7Ah     Kernel      CPU2 cp15 Performance monitor count (any) overflow New3DS
      7Bh     Kernel      CPU3 cp15 Performance monitor count (any) overflow New3DS
      7Ch-7Fh -           Unused?
      80h-3FEh            Don't exist (3DS/New3DS has only 80h IRQ sources)
      3FFh                None, no interrupt (or spurious interrupt)

The spurious interrupt (3FFh) might appear in an interrupt handler if the handler got triggered, but something (eg. another CPU) has cleared the IRQ flag before the handler got a chance to process it.

ARM11 MPCore Private Memory Region Register Summary

MPCore private memory region
The MPCore Private Memory Region contains additional ARM control registers (additionally to the CP15 coprocessor registers). The 3DS does have this region mapped at address 17E00000h and up.

      17E00000h 100h  MPCore SCU (Snoop Control Unit)
      17E00100h 100h  MPCore CPU interrupt interface for LOCAL CPU
      17E00200h 100h  MPCore CPU0 interrupt interface (aliased for debug purposes)
      17E00300h 100h  MPCore CPU1 interrupt interface (aliased for debug purposes)
      17E00400h 100h  MPCore CPU2 interrupt interface (aliased for debug purposes)
      17E00500h 100h  MPCore CPU3 interrupt interface (aliased for debug purposes)
      17E00600h 100h  MPCore CPU timer and watchdog for LOCAL CPU
      17E00700h 100h  MPCore CPU0 timer and watchdog
      17E00800h 100h  MPCore CPU1 timer and watchdog
      17E00900h 100h  MPCore CPU2 timer and watchdog  ;\if enabled in
      17E00A00h 100h  MPCore CPU3 timer and watchdog  ;/10141312h/13h
      17E00B00h 500h  MPCore Reserved (access causes a DECERR abort exception)
      17E01000h 1000h MPCore Global Interrupt distributor

Snoop Control Unit (SCU)

      Offset       Type Reset      Name
      17E00000h 4   R/W 00001FFEh  SCU Control Register
      17E00004h 4   R   (var)      SCU Configuration Register
      17E00008h 4   R/W -          SCU CPU Status
      17E0000Ch 4   W   -          SCU Invalidate All
      17E00010h 4   R/W 00000000h  SCU Performance Monitor Control Register
      17E00014h 4   R/W 00000000h  SCU Monitor Counter Events 0
      17E00018h 4   R/W 00000000h  SCU Monitor Counter Events 1
      17E0001Ch 4   R/W 00000000h  SCU Monitor Counter 0
      17E00020h 4   R/W 00000000h  SCU Monitor Counter 1
      17E00024h 4   R/W 00000000h  SCU Monitor Counter 2
      17E00028h 4   R/W 00000000h  SCU Monitor Counter 3
      17E0002Ch 4   R/W 00000000h  SCU Monitor Counter 4
      17E00030h 4   R/W 00000000h  SCU Monitor Counter 5
      17E00034h 4   R/W 00000000h  SCU Monitor Counter 6
      17E00038h 4   R/W 00000000h  SCU Monitor Counter 7
      17E0003Ch C4h -   -          SCU Reserved (0)

All SCU registers are byte accessible.
MP11 CPU Interrupt Interface Registers (for Interrupt Handling)

      Address       Type Reset value Function
      17E00100h 4   R/W  00000000h CPU IRQ Control Register
      17E00104h 4   R/W  000000F0h CPU IRQ Priority Mask Register
      17E00108h 4   R/W  00000003h CPU IRQ Binary Point Register
      17E0010Ch 4   R    000003FFh CPU IRQ Interrupt Acknowledge?? Register
      17E00110h 4   W    -         CPU IRQ End of Interrupt Register
      17E00114h 4   R    000000F0h CPU IRQ Running Priority Register
      17E00118h 4   R    000003FFh CPU IRQ Highest Pending Interrupt Register
      17E0011Ch E4h -    -         CPU IRQ Reserved

Above registers are for the LOCAL CPU, below are aliases for EACH CPU core.

      17E00200h 100h   MPCore CPU0 interrupt interface (aliased for debug purposes)
      17E00300h 100h   MPCore CPU1 interrupt interface (aliased for debug purposes)
      17E00400h 100h   MPCore CPU2 interrupt interface (aliased for debug purposes)
      17E00500h 100h   MPCore CPU3 interrupt interface (aliased for debug purposes)

All registers of the MP11 CPU interrupt interfaces must be accessed by 32bit transactions only.
Timer and Watchdog registers

      Offset       Type Reset     Name
      17E00600h 4   R/W 00000000h MPCore Timer0 Reload Value
      17E00604h 4   R/W 00000000h MPCore Timer0 Counter Value (decrementing)
      17E00608h 4   R/W 00000000h MPCore Timer0 Control Register
      17E0060Ch 4   R/W 00000000h MPCore Timer0 Interrupt Status
      17E00610h 10h -             Reserved
      17E00620h 4   R/W 00000000h MPCore Timer1/Watchdog Reload Value
      17E00624h 4   R/W 00000000h MPCore Timer1/Watchdog Counter Value (decrem.)
      17E00628h 4   R/W 00000000h MPCore Timer1/Watchdog Control Register
      17E0062Ch 4   R/W 00000000h MPCore Timer1/Watchdog Interrupt Status
      17E00630h 4   R/W 00000000h MPCore Timer1/Watchdog Reset Sent Register
      17E00634h 4   W   -         MPCore Timer1/Watchdog Disable Register
      17E00638h C8h -             Reserved

Above registers are for the LOCAL CPU, below are aliases for EACH CPU core.

      17E00700h 100h              MPCore CPU0 timer and watchdog
      17E00800h 100h              MPCore CPU1 timer and watchdog
      17E00900h 100h              MPCore CPU2 timer and watchdog  ;\if enabled in
      17E00A00h 100h              MPCore CPU3 timer and watchdog  ;/10141312h/13h

All timer and watchdog registers are word accessible only.
Note: There's also another ARM11 timer/cycle counter in CP15 registers.
Distributed Interrupt controller registers (for Interrupt Configuration)

      Address   Size  Type Reset     Function
      17E01000h 4     R/W  00000000h Interrupt Distributor Control Register
      17E01004h 4     R    -         Interrupt Controller Type Register
      17E01008h F8h   -    ....      Reserved
      17E01100h 20h   R/W  0000FFFFh Interrupt Enable set Registers ID0-ID31
      17E01104h ()         00000000h Interrupt Enable set Registers ID32 and up
      17E01120h 60h   -    ....      Reserved
      17E01180h 20h   R/W  0000FFFFh Interrupt Enable clear Registers ID0-ID31
      17E01184h ()         00000000h Interrupt Enable clear Registers ID32 and up
      17E011A0h 60h   -    ....      Reserved
      17E01200h 20h   R/W  00000000h Interrupt Pending set Registers
      17E01220h 60h   -    ....      Reserved
      17E01280h 20h   R/W  00000000h Interrupt Pending clear Registers
      17E012A0h 60h   -    ....      Reserved
      17E01300h 20h   R    00000000h Interrupt Active Bit Registers
      17E01320h E0h   -    ....      Reserved
      17E01400h 100h  R/W  00000000h Interrupt Priority Registers
      17E01500h 300h  -    ....      Reserved
      17E01800h 100h  R/W  00000000h Interrupt CPU targets Registers (a.)
      17E01900h 300h  -    ....      Reserved
      17E01C00h 40h   R/W  AAAAAAAAh Interrupt Configuration Registers ID0-ID15
      17E01C04h ()         28000000h Interrupt Configuration Registers ID29-ID31
      17E01C08h ()         00000000h Interrupt Configuration Registers ID32 and up
      17E01C40h C0h   -    ....      Reserved
      17E01D00h 20h   R    00000000h Interrupt Line Level Registers ID0-ID31
      17E01D04h ()         -         Interrupt Line Level Registers ID32 and up
      17E01D20h E0h   -    ....      Oddly: mirrors of above 20h bytes
      17E01E00h 100h  -    ....      Reserved
      17E01F00h 4     W    -         Software Interrupt Register
      17E01F0xh DCh?  -    ....      Reserved
      17E01FE0h 4     R    90h       Peripheral Identification Register 0
      17E01FE4h 4     R    13h       Peripheral Identification Register 1
      17E01FE8h 4     R    04h       Peripheral Identification Register 2
      17E01FECh 4     R    00h       Peripheral Identification Register 3
      17E01FF0h 4     R    0Dh       PrimeCell Identification Register 0
      17E01FF4h 4     R    F0h       PrimeCell Identification Register 1
      17E01FF8h 4     R    05h       PrimeCell Identification Register 2
      17E01FFCh 4     R    B1h       PrimeCell Identification Register 3
        a. Except for address 0x81C. See Interrupt CPU Targets Registers.

All Interrupt Distributor Registers are byte accessible.
Official specs: DDI0360F_arm11_mpcore_r2p0_trm.pdf

ARM11 MPCore - Snoop Control Unit (SCU)

Snoop Control Unit (SCU)
Below registers exists only once (not per CPU). However, the performance counters are somewhat supposed to be used as two counters per CPU.
17E00000h - SCU Control Register (R/W)
The SCU Control Register enables the SCU and controls its behavior. It must be accessed using a read-modify-write sequence.

      0     SCU Enable      (0=Disable, 1=Enable)
            (enable: maintain coherency between MP11 CPUs Level 1 data side caches)
            (in single CPU configuration, this bit has no effect and is always 0)
      1-4   Allow CPU0..3 to access SCU at 17E00000h..17E000FFh (0=No, 1=Yes)
      5-8   Allow CPU0..3 to access TMR at 17E00200h..17E005FFh (0=No, 1=Yes)
      9-12  Allow CPU0..3 to access IRQ at 17E00700h..17E00AFFh (0=No, 1=Yes)
      13    Report RAM Parity errors via parity error signals (0=Disable, 1=Enable)
      14-31 Reserved SBZ

Bit1-4: There is a mechanism that prevents all bits being cleared at the same time.
Bit13: Before enabling SCU parity checking, all SCU tag must be invalidated.
This register doesn't seem to allow to disable access to the Global Interrupt Distributor at 17E01000h-17E01FFFh (however, the MMU can disable the whole 4Kbyte page).
17E00004h - SCU Configuration Register (R)

      0-1   Number of ARM11 CPU cores   (0..3 = 1,2,3,4 CPU's)
      2-3   Reserved SBZ
      4-7   CPU0..3 Symmetric/Asymmetric Multi-processing (0=SMP/coherent, 1=AMP)
      8-9   CPU0 Tag RAM cache size (0=16KB, 1=32KB, 2=64KB, 3=Reserved)
      10-11 CPU1 Tag RAM cache size (0=16KB, 1=32KB, 2=64KB, 3=Reserved)
      12-13 CPU2 Tag RAM cache size (0=16KB, 1=32KB, 2=64KB, 3=Reserved)
      14-15 CPU3 Tag RAM cache size (0=16KB, 1=32KB, 2=64KB, 3=Reserved)
      16-31 Reserved SBZ

Cache size 16KB/32KB/64KB implies 64/128/256 indexes per tag RAM accordingly.
On New3DS this is 00005013h (even in Old3DS mode). But changes to 00005003h when using fastboot...?
17E00008h - SCU CPU Status Register (R/W)

      0-1   CPU0 status (0=Normal, 1=Reserved, 2=Dormant, 3=Powered-off)
      2-3   CPU1 status (0=Normal, 1=Reserved, 2=Dormant, 3=Powered-off)
      4-5   CPU2 status (0=Normal, 1=Reserved, 2=Dormant, 3=Powered-off)
      6-7   CPU3 status (0=Normal, 1=Reserved, 2=Dormant, 3=Powered-off)
      8-31  Reserved SBZ

Dormant mode and powered-off mode are controlled by an external power controller.
SCU CPU Status Register bits indicate to the external power controller which power domains can be powered down.
Before entering any other power mode than Normal, the MP11 CPU must set its status field to signal to the SCU which mode it is about to enter (so that the SCU can determine if it still can send coherency requests to the CPU). The MP11 CPU then executes a WFI entry instruction. When in WFI state, the PWRCTLOn bus is enabled and signals to the power controller what it must do with power domains.
The SCU CPU Status Register bits are used in conjunction with internal WFI entry signals to generate PWRCTLOn output pins.
The SCU CPU Status Register bits can also be read by a CPU exiting low-power mode to determine its state before executing its reset setup.
MP11 CPUs status fields take PWRCTLIn values at reset, except for nonpresent CPUs.
For nonpresent CPUs writing to this field has no effect.
17E0000Ch - SCU Invalidate All Register (W)

      0-3   Invalidate CPU0 ways (bit0-3   = Way 0,1,2,3)  (0=No, 1=Invalidate)
      4-9   Invalidate CPU1 ways (bit4-9   = Way 0,1,2,3)  (0=No, 1=Invalidate)
      8-11  Invalidate CPU2 ways (bit8-11  = Way 0,1,2,3)  (0=No, 1=Invalidate)
      12-15 Invalidate CPU3 ways (bit12-15 = Way 0,1,2,3)  (0=No, 1=Invalidate)
      16-31 Reserved SBZ

Allows to invalidate the tag RAMs on a per CPU and per way basis. This operation is atomic, that is, a write transfer to this address only terminates when all the lines have been invalidated. This register reads as 0.
Uh, what is a "way"?
17E00010h - Performance Monitor Control Register (R/W)

      0      Enable bit for all counters     (0=Disable, 1=Enable)
      1      Reset all count registers       (0=No, 1=Reset)
      2-7    Reserved SBZ
      8-15   Counter MN0..7 Interrupt Enable (0=Disable, 1=Enable)
      16-23  Counter MN0..7 Interrupt Flag (0=No, 1=Overflow/IRQ) ;write 1 to clear
      24-31  Reserved SBZ/RAZ

17E00014h - SCU Monitor Counter Events 0, bit0-31 (R/W)
17E00018h - SCU Monitor Counter Events 1, bit32-63 (R/W)

      0-7     EvCount0  Identifies the event for counter MN0
      8-15    EvCount1  Identifies the event for counter MN1
      16-23   EvCount2  Identifies the event for counter MN2 (if any)
      24-31   EvCount3  Identifies the event for counter MN3 (if any)
      48-55   EvCount6  Identifies the event for counter MN6 (if any)
      56-63   EvCount7  Identifies the event for counter MN7 (if any)
      32-39   EvCount4  Identifies the event for counter MN4 (if any)
      40-47   EvCount5  Identifies the event for counter MN5 (if any)

Event source number definitions:

      00h     Counter disabled
      01h     CPU0 Miss  ;\
      02h     CPU1 Miss  ; CPUn requested a coherent linefill that misses in all
      03h     CPU2 Miss  ; other CPUs. The request is sent to external memory
      04h     CPU3 Miss  ;/
      05h     CPU0 Hit   ;\
      06h     CPU1 Hit   ; CPUn requested a coherent linefill that hits in another
      07h     CPU2 Hit   ; CPU. The linefill is fetched from the relevant CPU cache
      08h     CPU3 Hit   ;/
      09h     CPU0 Error ;\
      0Ah     CPU1 Error ; CPUn was expected to have a coherent
      0Bh     CPU2 Error ; line in its cache but answers nonpresent.
      0Ch     CPU3 Error ;/
      0Dh     Line migration  ;-A line is directly transferred from one
                              ;  CPU to another on a linefill request instead of
                              ;  switching to SHARED.
      0Eh     Master0 Read port busy
      0Fh     Master1 Read port busy
      10h     Master0 Write port busy
      11h     Master1 Write port busy
      12h     A Read transfer is sent to the external memory
      13h     A Write transfer is sent to the external memory
      14h-1Eh N/A
      1Fh     CycleCount   ;-The counter increments on each CPU clock cycle
      20h-FFh N/A

17E0001Ch - SCU Monitor Counter MN0 (R/W) ;exists always
17E00020h - SCU Monitor Counter MN1 (R/W) ;exists always
17E00024h - SCU Monitor Counter MN2 (R/W) ;exists only for two or more CPUs
17E00028h - SCU Monitor Counter MN3 (R/W) ;exists only for two or more CPUs
17E0002Ch - SCU Monitor Counter MN4 (R/W) ;exists only for three or more CPUs
17E00030h - SCU Monitor Counter MN5 (R/W) ;exists only for three or more CPUs
17E00034h - SCU Monitor Counter MN6 (R/W) ;exists only for four CPUs
17E00038h - SCU Monitor Counter MN7 (R/W) ;exists only for four CPUs

      0-31  Counter (incrementing upon selected event)

New3DS has eight counters (even in Old3DS mode).

ARM11 MPCore - Timer and Watchdog

Timer and Watchdog
Below registers are for the LOCAL CPU core (the other CPU cores have their own registers, mapped at the same address).
17E00600h - MPCore Timer0 Reload Value (R/W)
17E00620h - MPCore Timer1/Watchdog Reload Value (R/W)

      0-31  Reload Value

The Reload value is copied to the Counter in two situations:
1) When the Counter decrements to zero (with Auto-reload enabled).
2) When writing to the Reload register (in watchdog mode this is the only way to refresh the watchdog, and to prevent it from resetting the CPU).
17E00604h - MPCore Timer0 Counter Value (R/W)
17E00624h - MPCore Timer1/Watchdog Counter Value (R/W) (R in watchdog mode)

      0-31  Counter Value (decrementing)

If the MP11 CPU belonging to the timer is in debug state, the counter does not decrement until the MP11 CPU returns to non debug state.
17E00608h - MPCore Timer0 Control Register (R/W)
17E00628h - MPCore Timer1/Watchdog Control Register (R/W)

      0     Timer Enable     (0=Stop, 1=Enable/Decrement)
      1     Auto-reload      (0=One-shot, stop at zero, 1=Auto-reload at zero)
      2     Interrupt Enable (0=Disable, 1=Trigger Interrupt ID 29/30 at zero)
      3     Timer0: Reserved      (0=Timer, fixed, always 0) (R)
      3     Timer1: Watchdog mode (0=Timer, 1=Watchdog)      (R or R/W)
              Note: Bit3 can be cleared via 17E00634h only
      4-7   Reserved (0)
      8-15  Prescaler (0..255 = CPU_CLK/2 divided by 1..256)
      16-31 Reserved (0)

17E0060Ch - MPCore Timer0 Interrupt Status (R/ack)
17E0062Ch - MPCore Timer1/Watchdog Interrupt Status (R/ack)

      0     Event flag (counter reached zero)  (0=No, 1=Event)  ;write 1 to clear
      1-31  Reserved

If the timer interrupt is enabled, Interrupt ID 29/30 is set as Pending in the Interrupt Distributor after the event flag is set.
17E00630h - MPCore Timer1/Watchdog Reset Sent Register (R/ack)

      0     Reset flag  (0=Normal, 1=Reset caused by Watchdot)  ;write 1 to clear
      1-31  Reserved

17E00634h - W - MPCore Timer1/Watchdog Disable Register

      0-31  Key (write 12345678h, then write 87654321h to disable watchdog)

Switches the watchdog back to Timer mode (ie. clears bit3 in Control Register).
Calculating timer intervals

     The timer interval is calculated using the following equation:
       ((PRESCALER_value+1)*(Reload_value+1)*x2 / CPU_CLK_frequency
     This equation can be used to calculate the period between two events out of
     the timers and the watchdog time-out time.

Uh, doesn't that mean that reload occurs on UNDERFLOW (not on ZERO)...?

ARM11 MPCore - Interrupt Configuration

Distributed Interrupt Controller (for Interrupt Configuration)
These registers are mostly used for interrupt configuration (and for internally maintaining an list of pending/active interrupts).

      -- Most of these registers exists only once (not per CPU) --

Except, the Priority for Software Interrupts 00h-0Fh can be configured per LOCAL CPU. And, the Pending and Active flags do <internally> exist for each CPU (for Software Interrupts 00h-0Fh, they do even exists for "From each CPU to each CPU"). However, reading the Pending/Active/Priority flags doesn't fully represent all of the internal per-CPU states.
17E01000h - Interrupt Distributor Control Register (R/W)

      0     Global Interrupt Controller Enable    (0=Disable, 1=Enable)
      1-31  Reserved

If bit0=0, no interrupts at all are sent to the CPU interrupt interfaces.
17E01004h - Interrupt Controller Type Register (R)

      0-4   Number of Interrupt IDs   (0-7 = 20h,40h,60h,...,100h) (8-31=Reserved)
      5-7   Number of ARM11 CPU cores (0-3 = 1,2,3,4 CPU's)        (4-7=Reserved)
      8-31  Reserved

Note: Interrupt ID 00h-1Fh are internal IRQs, ID 20h-FFh are external IRQs.
On New3DS this 00000063h, 4 CPUs and 80h IRQs (even in Old3DS mode).
17E01100h..17E0111Fh - Interrupt Enable Set Registers (256 x 1bit) (R/W)
17E01180h..17E0119Fh - Interrupt Enable Clear Registers (256 x 1bit) (R/W)

      0-15    Interrupt 00h-0Fh (Read: Always 1=Enabled)      (Write=No effect)
      16-255  Interrupt 10h-FFh (Read: 0=Disabled, 1=Enabled) (Write: 1=Set/Clear)

Enable means that pending IRQs will be transmitted to the targeted CPUs.
The enable bit, when set to 0, does not prevent an edge-triggered interrupt from becoming Pending.
The enable bit, when set to 0, does prevent a level sensitive interrupt from becoming Pending only if asserted by the hardware pin, INT.
Note: If an interrupt is Pending or Active when its enable bit is set to 0, it remains in its current state.
17E01200h..17E0121Fh - Interrupt Pending set Registers (256 x 1bit) (R/W)
17E01280h..17E0129Fh - Interrupt Pending clear Registers (256 x 1bit) (R/W)

      0-15   Interrupt 00h-0Fh pending on local CPU (0=No, 1=Pending) (W=??)
      16-31  Interrupt 10h-1Fh pending on local CPU (0=No, 1=Pending) (W=?)
      32-255 Interrupt 20h-FFh pending on CPU(s)??  (0=No, 1=Pending) (W=Set/Clr)
     Bit0-31:   Reading returns 1 if pending on local CPU core
     Bit32-255: Reading returns 1 if pending on one or more ANY CPU cores
                 (if it's pending on the LOCAL CPU can be seen only once when
                 reading the Acknowledge register?)
                 (the Enable and Target bits do also somewhat imply whether
                 the interrupt could have become pending on local CPU)
     Bit0-15:   Write/Set is ignored (use 17E01F00h Software Interrupt instead)
     Bit16-31:  Write/Set is...?
     Bit32-255: Write/Set allows to force the state=1 for ALL TARGET CPU cores
     Bit0-15:   Write/Clear is...?
     Bit16-31:  Write/Clear is...?
     Bit32-255: Write/Clear allows to force the state=0 for ALL CPU cores

17E01300h..17E0131Fh - Active Bit Registers (256 x 1bit) (R)

      0-31   Interrupt 00h-1Fh is active on local CPU        (0=No, 1=Active)
      32-255 Interrupt 20h-FFh is active on one or more CPUs (0=No, 1=Active)

Active means that the interrupt is being processed on at least one MP11 CPU.
17E01400h..17E014FFh - Interrupt Priority Registers (256 x 8bit) (R/W)
The priority determines which interrupt will show up next in the interrupt interface registers. And, the interface registers can be used to manually disable lower priority interrupts during 'critical sections'. And, while processing an interrupt, the hardware will automatically disable interrupts with same or lower priority (optionally, the "Binary Point" feature allows to ignore the LSBs of the priorioty, eg. ignoring the lowest bit with allow to also disable interrupts with slightly higher priority).

      0-127     Interrupt 00h-0Fh Priority for local CPU (bit0-3=SBZ, bit4-7=Prio)
      128-231   Interrupt 10h-1Ch Priority for what?     (bit0-3=SBZ, bit4-7=Prio)
      232-255   Interrupt 1Dh-1Fh Priority for local CPU (bit0-3=SBZ, bit4-7=Prio)
      256-2047  Interrupt 20h-FFh Priority for all CPUs  (bit0-3=SBZ, bit4-7=Prio)

Priority values are 00h=Highest... E0h=Lowest, or F0h=None (same as interrupt disabled).
When multiple Pending interrupts have the same priority, the selected interrupt is the one with lowest ID. If there are multiple Pending software interrupts with the same ID, the lowest MP11 CPU source is selected.
17E01800h..17E018FFh - Interrupt CPU Targets Registers (256 x 8bit) (R/W)
These registers store the list of MP11 CPUs for which an interrupt can be Pending. Interrupt target registers are ignored in cases of software triggered interrupts.

      0-231     Interrupt 00h-1Ch Target (fixed 00h) (see 17E01F00h instead)  (-)
      232-255   Interrupt 1Dh-1Fh Target (fixed 01h/02h/04h/08h for CPU0..3)  (R)
      256-2047  Interrupt 20h-FFh Target (bit0-3=CPU0..3, bit4-7=SBZ)       (R/W)

Modifying a CPU target list has no influence on a Pending or Active interrupt, but takes effect on a subsequent assertion of the interrupt.
17E01C00h..17E01C3Fh - Interrupt Configuration Registers (256 x 2bit) (R/W)
Interrupt Configuration Registers define the assertion condition and the software model of each interrupt.

      0-31     Interrupt 00h-0Fh Condition (can be 2,3) (always rising-edge)
      32-57    Interrupt 10h-1Ch Condition (always 0)
      58-61    Interrupt 1Dh-1Eh Condition (always 2) (always N-N, rising-edge)
      62-63    Interrupt 1Fh     Condition (always 0) (ignored, always low active)
      64-511   Interrupt 20h-FFh Condition (can be 0,1,2,3)

Interrupt line encodings for bits 1 and 0:

      00h = N-N software model, level high active
      01h = 1-N software model, level high active
      02h = N-N software model, rising edge sensitive
      03h = 1-N software model, rising edge sensitive

The N-N and 1-N models are relevant only if more than one CPU is configured as Target:

      1-N model: An interrupt that is taken on any CPU clears the Pending status
        on all CPUs.
      N-N model: All CPUs receive the interrupt independently. The Pending status
        is cleared only for the CPU that takes it, not for the other CPUs. The N-N
        model has been deprecated in the latest interrupt controller architecture.

Unknown how 1-N and N-N differ for Interrupt 00h-0Fh (it's said that each CPU has it's own pending flags for 00h-0Fh, so the model should be always "1-1").

      Obscure Notes:
      - With the 1-N software model, the nIRQ input is asserted on all CPUs
        configured in the CPU Targets Register. Uh, but Interrupt 1Fh is fixed?
      - If more than one of these CPUs reads the Interrupt Acknowledge Register
        at the same time, they can all acknowledge the same interrupt. The
        interrupt service routine must ensure that only one of them tries to
        process the interrupt, with the others returning after writing the ID to
        the End of Interrupt Register. Uh, does that apply to nIRQ only? Or to
        all IRQs?

17E01D00h..17E01D1Fh - Interrupt Line Level Registers (256 x 1bit) (R)

      0-31    Dummy line level bits for Internal IRQ 00h..1Fh (always 0)
      32-255  Interrupt line level for External IRQ 20h..FFh  (0=Low, 1=High)

17E01F00h - Software Interrupt Register (W)

      0-9     Interrupt ID (0..FFh? or 0..0Fh/1Fh?) (100h..1FFh=Reserved/ignored)
      10-15   SBZ
      16-19   Send the interrupt to CPU0..3 (0=No, 1=Yes) ;used only if Bit24-25=0
      20-23   SBZ
      24-25   Target list mode (0=Bit16-19, 1=Other CPUs, 2=Local CPU, 3=Reserved)
      26-31   SBZ

This can be used to trigger an interrupt (identified with its ID) to a list of MP11 CPUs.

ARM11 MPCore - Interrupt Handling

CPU Interrupt Interface Registers (for Interrupt Handling)
Below registers are for the LOCAL CPU core (the other CPU cores have their own registers, mapped at the same address).
17E00100h - CPU Interface Control Register (R/W)

      0     Interrupt Enable for local CPU   (0=Disable, 1=Enable)
      1-31  Reserved

When disabled: External nIRQ input is still working (and, in that case, nIRQ should be handled directly; without using the disabled ACK/EOI registers).
17E00104h - Priority Mask Register (R/W)
The priority mask is used to prevent interrupts from being sent to the MP11 CPU. The CPU Interface asserts an interrupt request to an MP11 CPU if the priority of the highest Pending interrupt sent by the Interrupt Distributor is strictly higher than the mask set in the Priority Mask Register.

      0-3  Unused SBZ
      4-7  Priority Mask value
                NOTE: This is a 4bit COMPARE value (not an AND-mask)
                   0xF Interrupts with priority 0x0-0xE are not masked.
                   0x0 All interrupts are masked.
      8-31 Unused SBZ

17E00108h - Binary Point Register (R/W)
The Binary Point Register is used to determime whether a new interrupt pre-empts a currently Active one, using only part, or none of the priority level.

      0-2   Binary Point (see below)
      3-31  Reserved

Binary point bit values assignment:

      03h = All bits4,5,6,7 of priority are compared for pre-emption
      04h = Only bit5,6,7   of priority are compared for pre-emption
      05h = Only bit6,7     of priority are compared for pre-emption
      06h = Only bit7       of priority is compared for pre-emption
      07h = No bits compared, no pre-emption is performed (no nested IRQs)
      00h,01h,02h = Same as 03h

This is related to the "Running Priority Register" (see there for details).
17E0010Ch - Interrupt Acknowledge (ACK) Register (R)

      0-9     Interrupt ID          (00h..FFh, or 3FFh=None)
      10-12   Source for ID=00h-0Fh (0..3=CPU0..3, or always 0 for ID=10h-3FFh)
      13-31   Unused (0)

Reading returns the ID of the next pending interrupt with highest priority, and automatically switches the interrupt from pending state to active state (indicating that it is being processed). The CPU should then process the interrupt, and, thereafer, use End of Interrupt register (to indicate that processing is done).
17E00110h - End of Interrupt (EOI) Register (W)

      0-31    Same format as Interrupt Acknowledge Register (see there)

Writing clears the Active flag for the corresponding interrupt, indicating that interrupt processing is done. The written value should be same as the (memorized) value from the Interrupt Acknowledge Register.
17E00114h - Running Priority Register (R)
Indicates the priority of the currently processed interrupt (the last acknowledged and not yet completed interrupt on the local CPU core).

      0-3  Reserved SBZ
      4-7  Priority (0=Highest .. 14=lowest, 15=None/No interrupt being processed)
      8-31 Reserved

All interrupts with same or lower priority are automatically disabled until finishing the current interrupt (by writing to End of Interrupt register).
Optionally, the "Binary Point Register" allows to ignore the priority LSB(s) when comparing the new Interrupt's priority with the currently "Running Priority" (for example, ignoring the lower two bits would cause an interrupt with priority=5 to also disable slighly higher priority interrupts with priority=6..7).
17E00118h - Highest Pending Interrupt Register (R)

      0-31    Same format as Interrupt Acknowledge Register (see there)

Same as Interrupt Acknowledge Register, except that reading doesn't make the corresponding interrupt Active.
Uh, and supposedly doesn't clear its Pending state... or does it?

ARM11 MPCore Distributed Interrupt Controller (Blurb)

10.1.1 Distributed Interrupt Controller clock frequency
The Distributed Interrupt Controller logic is clocked at half the frequency of the MPCore CPUs because of power and area considerations. Reducing clock speed reduces dynamic power consumption. The lower clock speed requires less pipelining in the design. This means that the overall impact of the reduced clock speed on the Distributed Interrupt Controller is kept to a minimum.
Note
As a consequence, the minimum pulse width of signals driving external interrupt lines is two CPU clock cycles.
10.2 Terminology - From point of view of an MP11 CPU, an interrupt can be:

      Inactive: An Inactive interrupt is one that is nonasserted, or which in a
        multi-processing environment has been completely processed by that MP11
        CPU but can still be either Pending or Active in some of the MP11 CPUs to
        which it is targeted, and so might not have been cleared at the interrupt
        source.
      Pending: A Pending interrupt is one that has been asserted, and for which
        processing has not started on that MP11 CPU.
      Active: An Active interrupt is one that has been started on that MP11 CPU,
        but processing is not complete.

An interrupt can be Pending and Active at the same time. This can happen in the case of edge triggered interrupts, when the interrupt is asserted while the MP11 CPU has not finished handling the first occurrence. For level-sensitive interrupts it can only happen if software triggers it. See Interrupt Configuration Registers, 0xC00-0xC3C on page 10-17.

      Pre-emption: An Active interrupt can be pre-empted when a new interrupt of
        higher priority interrupts MP11 CPU interrupt processing. For the purpose
        of this document, an Active interrupt can be running if it is actually
        being processed, or pre-empted.

The Distributed Interrupt Controller consists of:
Interrupt Distributor:
The Interrupt Distributor handles interrupt detection and interrupt prioritization.
CPU interrupt interfaces:
There is one CPU interrupt interface per MP11 CPU. The MP11 CPU interrupt interfaces handle interrupt acknowledgement, interrupt masking, and interrupt completion acknowledgement.
10.3 Interrupt Distributor
The Interrupt Distributor centralizes all interrupt sources for the ARM11 MPCore processor before dispatching the highest priority ones to each individual MP11 CPU.
All interrupt sources are identified by a unique ID. All interrupt sources have their own configurable priority and list of targeted CPUs, that is, a list of CPUs to which the interrupt is sent when triggered by the Interrupt Distributor.
Note
nFIQ interrupts are not handled by the Distributed Interrupt Controller so that nFIQ interrupt input pins are directly routed to their respective CPU.
Interrupt sources are of the following types:
Interprocessor interrupts (IPI)
Each MP11 CPU has private interrupts, ID0-ID15, that can only be triggered by software. These interrupts are aliased so that there is no requirement for a requesting MP11 CPU to determine its own ID when it deals with IPIs. The priority of an IPI depends on the receiving CPU, not the sending CPU.
Private timer and/or watchdog interrupts.
Each MP11 CPU has its own private timer and watchdog that can generate interrupts, using ID29 and ID30.
A legacy nIRQ pin
In legacy IRQ mode the legacy nIRQ pin, on a per CPU basis, bypasses the Interrupt Distributor logic and directly drives interrupt requests into the MP11 CPU. In legacy IRQ mode, if bit [0] of the CPU Interface Control Register is 0, then no interrupts are raised based on input from the Interrupt Distributor. If bit [0] is 1, then all interrupts are received from the Interrupt Distributor.
When an MP11 CPU uses the Distributed Interrupt Controller (rather than the legacy pin in the legacy mode) by enabling its own CPU interface, the legacy nIRQ pin is treated like other interrupt lines and uses ID31.
Hardware interrupts
Hardware interrupts are triggered by programmable events on associated interrupt input lines. MP11 CPUs can support up to 224 interrupt input lines. The interrupt input lines can be configured to be edge sensitive (posedge) or level sensitive (high level). Hardware interrupts start at ID32.
10.3.1 Interrupt Distributor overview
The Interrupt Distributor holds the list of Pending interrupts for each CPU, and then selects the highest priority interrupt before issuing it to the CPU interface. Interrupts of equal priority are resolved by selecting the lowest ID.
The Interrupt Distributor consists of a register-based list of interrupts, their priorities and activation requirements (CPU targets). In addition the state of each interrupt on each CPU is held in the associated state storage.
The prioritization logic is physically duplicated for each CPU to enable the selection of the highest priority for each CPU.
The Interrupt Distributor holds the central list of interrupts, processors and activation information, and is responsible for triggering software interrupts to processors.
The CPU Interface acknowledges interrupts and changes interrupt priority masks.
The Interrupt Distributor transmits to the CPU interrupt interfaces their highest Pending interrupt. It receives back the information that the interrupt has been acknowledged, and can then change the status of the corresponding interrupt. The CPU Interface also transmits End of Interrupt Information (EOI), which enables the Interrupt Distributor to update the status of this interrupt from Active to Inactive.

                        .-----------.  .------------- Core Acknowledge, and
            .---------->|  Decoder  |  |------------- End Of Interrupt (EOI)
            |           '-----------'  |------------- from CPU Interface
            |              ^       ^   |-------------
            |              |       |   |
            V              V       V   V               Top priority interrupts
         .-----------.----------.--------.---------.
      -->|           | Priority | Status |         |   .--------.------.
      -->|           | Priority | Status |         |-->| Irq.no | Prio |--> CPU0
      -->|           | Priority | Status | Priori- |   '--------'------'
      -->| Interrupt | Priority | Status | zation  |   .--------.------.
      -->| Interface | Priority | Status | and     |-->| Irq.no | Prio |--> CPU1
      -->|           | Priority | Status | Select- |   '--------'------'
      -->|           | Priority | Status | ion     |   .--------.------.
      -->|           | Priority | Status |         |-->| Irq.no | Prio |--> CPU2
      -->|           | Priority | Status |         |   '--------'------'
      -->|           | Priority | Status |         |   .--------.------.
      -->|           | Priority | Status |         |-->| Irq.no | Prio |--> CPU3
      -->|           | Priority | Status |         |   '--------'------'
         '-----------'----------'--------'---------'                    IRQ's to
                         Interrupt List                                 each CPU

10.3.2 Behavior of the Interrupt Distributor
When the Interrupt Distributor detects an interrupt assertion, it sets the status of the interrupt for the targeted MP11 CPUs to Pending. Level-triggered interrupts cannot be marked as Pending if they are already Active for at least one MP11 CPU.
For each MP11 CPU the prioritization and selection block searches for the Pending interrupt with the highest priority. This interrupt is then sent with its priority to the CPU Interface.
The CPU Interface returns information to the Distributor when the CPU acknowledges (Pending to Active transition) or clears an interrupt (Active to Inactive transition). With the given interrupt ID, the Interrupt Distributor updates the status of this interrupt according to the information sent by the CPU Interface.
When an interrupt is triggered by the Software Interrupt Register or the Set-pending Register, the status of that interrupt for the targeted CPU or CPUs is set to Pending. This interrupt then has the same behavior as a hardware interrupt. The distributor does not differentiate between software and hardware triggered interrupts.

ARM Vector Floating-point Unit (VFP)

The VFP unit exists on 3DS ARM11.
ARM VFP Floating Point Registers
ARM VFP Floating Point Control/Status Registers
ARM VFP Floating Point Opcode Encoding
ARM VFP Floating Point Maths Opcodes
ARM VFP Floating Point Load/Store Opcodes
Floating Point
The floating point hardware is called VFPv2 (Vector Floating-point).

     ARM DDI 0100I ARM Architecture Reference Manual (for ARMv6 wirh VFPv2)
     ARM DDI 0360F ARM11 MPCore r2p0, contains more (mostly useless) VFPv2 info

The Fxxxx floating point opcodes are aliases for CP10/CP11 copressor numbers; CP10 used for single, and CP11 for double precision instructions.

ARM VFP Floating Point Registers

Floating point Registers
Registers S0-S31 can contain Single-precision float values, or 32bit Integers (for conversion to/from float format), or a pair of two Single-precision registers can contain one Double-precision float value.

      Scalar Bank       Vector bank 1       Vector bank 2       Vector bank 3
      S1:S0    D0       S9:S8    D4         S17:S16  D8         S25:S24  D12
      S2:S3    D1       S11:S10  D5         S19:S18  D9         S27:S26  D13
      S5:S4    D2       S13:S12  D6         S21:S20  D10        S29:S28  D14
      S7:S6    D3       S15:S14  D7         S23:S22  D11        S31:S30  D15

The VFP supports "Scalar" and "Vector" modes (and a mixed "Vector/Scalar" mode).
The "Vector" mode can perform simultaneous operations on up to 8 singles, or up to 4 doubles (via Vector LEN and STRIDE selected in FPSCR register).
The registers are organized in "banks", and vectors cannot cross banks (eg. using operand S23 with LEN=3, STRIDE=2 would use registers S23,S17,S19).
Scalar Mode, Fd=Fm <op> Fn
The "Scalar" mode performs operations on 1 single or double. This done in any of the following situations:

     - When FPSCR register is set to Vector LEN=1 (and STRIDE=1), or
     - When Destination is S0..S7 or D0..D3 (scalar bank), or
     - When using FCMP comparision opcodes, or
     - When using FCVT or FxxTOxx conversion opcodes, or
     - When using FMxxRxx register transfer opcodes, or
     - When using FLDxx/FSTxx load/store (whereof, FLDM/FSTM can transfer multiple
       registers in vector-like fashion; regardless of LEN/STRIDE settings)

Vector Mode, Fd[LEN]=Fm[LEN] <op> Fn[LEN]
The vector mode does merely perform the selected operation on all array elements, this is correct for cases like Vector+Vector addition, but incorrect for Vector*Vector multiplication (to get the final result one must manually compute the sum of the results).

     - When FPSCR register is set to Vector LEN=2..8 (and STRIDE=1..2), and
     - When Source and Destination are S8..S31 or D4..D15 (vector banks), and
     - When using FADD, FSUB, FDIV, FCPY, FABS, FNEG, FSQRT, or FxMxx multiply

Mixed Mode, Fd[LEN]=Fm <op> Fn[LEN]
This allows to add/multiply/etc. all elements of a vector by a scalar value. This is done when combining vectors operands with the following:

     - When Source operand Fm is S0..S7 or D0..D3 (scalar bank), and
     - othersise same conditions as for Vector mode

Integer Format (S0..S31 aka I0..I31)

      31-0   Integer (signed or unsigned, depending on FxxTOxx opcode)

The VFP can't do integer maths, however, one can load/store integer values in S0..S31, and then use the FxxTOxx opcodes to convert integers to/from float format. The integers are always 32bit (no matter if converting Single/Double precision float values).
Single Precision Registers (float1.8.23) (S0..S31)

      31     1bit  Sign (0=Positive, 1=Negative)
      30-23  8bit  Exponent (01h..FEh=for 2^(N-7Fh), or 00h/FFh=Special)
      22-0   23bit Fraction (0..7FFFFFh)

Double Precision Registers (float1.11.52) (D0..D15)

      63     1bit  Sign (0=Positive, 1=Negative)
      62-52  11bit Exponent (001h..7FEh=for 2^(N-3FFh), or 000h/7FFh=Special)
      51-0   52bit Fraction (0..FFFFFFFFFFFFFh)

Exponent 01h..FEh (Single) or 001h..7FEh (Double):

      Sign * 2^(exponent-7Fh) * (1.fraction)    ;Single
      Sign * 2^(exponent-3FFh) * (1.fraction)   ;Double

Exponent 00h (Single) or 000h (Double), aka Small Numbers and Zero:

      Sign * 2^(-7Eh) * (0.fraction)            ;Single
      Sign * 2^(-3FEh) * (0.fraction)           ;Double
      The above includes 0 being encoded as fraction=0, the sign bit is ignored
      for cases like "compare +/-0", but the sign is used for "divide by +/-0".
      Small numbers in 0.fraction format may require extra clock cycles for
      counting leading zeroes; unknown if that problem does actually exist on
      ARM hardware, however, the "flush to zero" feature (see FPSCR.bit24) can
      be used to avoid that issue; 0.fraction will be then replaced by 0.000.

Exponent FFh (Single) or 7FFh (Double), aka NaN's and Infinite:

      fraction=000000h          or 0000000000000h                 +/-Infinite
      fraction=000001h..3FFFFFh or 0000000000001h..7FFFFFFFFFFFFh +/-Signaling NaNs
      fraction=400000h          or 8000000000000h                 +/-Default NaN
      fraction=400000h..7FFFFFh or 8000000000000h..FFFFFFFFFFFFFh +/-Quite NaNs
      NaNs (Not a Number) can be used for abstract non-numeric expressions; this
      isn't useful for normal maths, but may be useful if a database contains
      entries like "Weight=UNKNOWN". If so, one may handle the NaN before passing
      it to the floating point unit, or otherwise the hardware will either trigger
      an exception (Signaling NaNs) or leave the NaN unchanged (Quite NaNs),
      eg. "UNKNOWN*2+3 = UNKNOWN", or replace it by Default NaN (if FPSCR.bit25=1).
      Different NaNs can be compared using integer comparisons, float comparisions
      of NaNs have "unordered" results (even when comparing a NaN with itself).

Multiply Note
When multiplying vector*vector, the hardware does merely multiply the components (without computing the sum of the multiply results). To get sum, one could use FMUL and several FADD's with different strides. Or better, for multiple vector*vector multiplications, use FMUL and several FMAC's with source data rearranged as so:

      FMUL (X,X,X,X,X,X,X,X)*(X,X,X,X,X,X,X,X)
      FMAC (Y,Y,Y,Y,Y,Y,Y,Y)*(Y,Y,Y,Y,Y,Y,Y,Y)
      FMAC (Z,Z,Z,Z,Z,Z,Z,Z)*(Z,Z,Z,Z,Z,Z,Z,Z)
      FMAC (W,W,W,W,W,W,W,W)*(W,W,W,W,W,W,W,W)

Ie. in that case, the 1st "vector" contains the X components from up to eight (X,Y,Z,W) vectors.

ARM VFP Floating Point Control/Status Registers

FPSID Register (Floating Point System ID) (R)

      31-24  Implementor code (41h=ARM)
      23     Hardware/software implementation (0=Hardware, 1=Software)
      22-21  FSTMX/FLDMX format  (0=Format 1, Other=Reserved)
      20     Supported Precision (0=Single and Double, 1=Single only)
      19-16  Architecture version number (0=VFPv1, 1=VFPv2, 2-15=Reserved)
      15-8   Primary part number of VFP implementation (20h=VFP11) ;\Implementation
      7-4    Variant number                            (0Bh=MPCore); defined
      3-0    Revision number of the part               (04h=Fourth);/

New3DS: 410120b4h = VFPv2 D variant (with single AND double precision).
FPSCR Register (Floating Point Status/Control Register for user-level) (R/W)

      31     N Flag (1=Comparision result is Less Than)
      30     Z Flag (1=Comparision result is Equal)
      29     C Flag (1=Comparision result is Equal, Greater Than, or Unordered)
      28     V Flag (1=Comparision result is Unordered)
             Note: Use FMSTAT opcode to transfer above flags to ARM CPSR flags
      27-26  Unused (0)
      25     Default Nan mode   (XXX see page C2-16) (0=Disable, 1=Enable)
      24     Flush-to-zero mode (XXX see page C2-14) (0=Disable, 1=Enable)
      23-22  Rounding mode (0=To Nearest, 1=Up, 2=Down, 3=Towards Zero)
      21-20  Vector Stride (0/3 = 1/2 Singles; or 0/3 = 1/2 Doubles) (1/2=Reserved)
      19     Unused (0)
      18-16  Vector Len    (0..7 = 1..8 Singles; or 0..3 = 1..4 Doubles)
      15     Trap Enable Input Denormal (aka Subnormal)     ;\
      14-13  Unused (0)                                     ;
      12     Trap Enable Inexact                            ; Trap Enable aka
      11     Trap Enable Underflow                          ; Exception Enable
      10     Trap Enable Overflow                           ;
      9      Trap Enable Division by Zero                   ;
      8      Trap Enable Invalid Operation                  ;/
      7      Cumulative Exception Input Denormal            ;\
      6-5    RES                                            ;
      4      Cumulative Exception Inexact                   ; Cumulative what...?
      3      Cumulative Exception Underflow                 ;
      2      Cumulative Exception Overflow                  ;
      1      Cumulative Exception Division by Zero          ;
      0      Cumulative Exception Invalid Operation         ;/

FPEXC Register (Floating Point Exception Register for system-level) (R/W)

      31     Exception Flag ... long blurb replated to process swap code
      30     Enable Floating Point Instructions (0=Disable, 1=Enable)
      29-0   Sub-architecture defined (see below for mpcore)
     Extra mpcore bits:
      29     Unused (0)
      28     FPINST2 instruction valid flag
      27-11  Unused (0)
      10-8   VECITR Number of remaining iterations after exception (0..6=1..7, 7=0)
      7      INV Input exception flag
      6-4    Unused (0)
      3      UFC Potential Underflow Flag
      2      OFC Potential Overflow Flag
      1      Unused (0)
      0      IOC Potential invalid operation flag

The exception handler must clear bit31 and bit28.
FPINST - Floating-Point Instruction Register, Privileged 0xEE000A00 (R/W)
Contains the opcode that has triggered the exception. The Cond field in bit28-31 is changed to 0Eh (Always), and the Fd:D, Fn:N, Fm:M are changed to indicated the fault-location within a vector (with FPEXC.bit8-10 indicating the remaining unprocessed elements of the vector).
FPINST2 - Floating-Point Instruction Register 2, Privileged UNP (R/W)
If FPEXC.bit28=1, then this register contains another float opcode (that was prefetched, but not yet executed). The Cond field in bit28-31 is changed to 0Eh (Always). The exception handler should handle the failed FPINST opcode, then try to execute prefetched FPINST2 opcode, and then return from exception.
MVFR0, Media and VFP Feature Register 0, Any 0x11111111 (R)

      31-28  VFP hardware support level when user traps are disabled
             (01h=In MPCore processors when Flush-to-Zero and Default_NaN and
             Round-to-Nearest are all selected in FPSCR, the coprocessor does not
             require support code. Otherwise floating-point support code is
             required)
      27-24  Support for short vectors           (01h=Yes)
      23-20  Support for hardware square root    (01h=Yes)
      19-16  Support for hardware divide         (01h=Yes)
      15-12  Support for software/user traps     (01h=Yes/support code is required)
      11-8   Support for double precision VFP    (01h=Yes, v2)
      7-4    Support for single precision VFP    (01h=Yes, v2)
      3-0    Support for the media register bank (01h=Yes/support 16, 64bit regs)

MVFR1 - Media and VFP Feature Register 1, Any 0x00000000 (R)

      31-28  Reserved
      11-8   Support for media extension, single precision floating-point (00h=No)
      7-4    Support for media extension, integer instructions            (00h=No)
      3-0    Support for media extension, load/store instructions         (00h=No)

ARM VFP Floating Point Opcode Encoding

Comparision of normal ARM copro opcodes and VFP opcodes

      |..3 ..................2 ..................1 ..................0|
      |1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0|
      |_Cond__|1_1_0_0_0_1_0|L|__Rn___|__Rd___|__CP#__|_CPopc_|__CRm__| 2reg normal
      |_Cond__|1_1_0_0_0_1_0|L|__Rn___|__Rd___|__CP#__|0|0|M|1|__Fm___| 2reg on VFP
      |_Cond__|1_1_0|P|U|N|W|L|__Rn___|__CRd__|__CP#__|____Offset_____| Mem normal
      |_Cond__|1_1_0|P|U|D|W|L|__Rn___|__Fd___|__CP#__|____Offset_____| Mem on VFP
      |_Cond__|1_1_1_0|_CPopc_|__CRn__|__CRd__|__CP#__|_CP__|0|__CRm__| CDP normal
      |_Cond__|1_1_1_0|p|D|q|r|__Fn___|__Fd___|__CP#__|N|s|M|0|__Fm___| CDP on VFP
      |_Cond__|1_1_1_0|CPopc|L|__CRn__|__Rd___|__CP#__|_CP__|1|__CRm__| 1reg normal
      |_Cond__|1_1_1_0|CPopc|L|__Fn___|__Rd___|__CP#__|N|0_0|1|0_0_0_0| 1reg on VFP

      Cond             = Condition
      L                = Load/Store direction for memory/register transfers
      Fm:M, Fn:N, Fd:D = Float Registers S0..S31 (or D0..D15, with LSB=0)
      Rd, Rn           = ARM Registers
      PUW, pqrs, CPopc = Opcode bits
      CP#              = Coprocessor number (0Ah=Single-, 0Bh=Double-Precision)
      Offset           = Address step, implies number of registers for FLDM/FSTM

ARM VFP Floating Point Maths Opcodes

VFP data-processing primary opcodes

      pqrs cp10/cp11                  Instruction functionality
      0000 FMAC{S|D}{cond} Fd,Fn,Fm   Fd = +(Fn*Fm)+Fd   ;Multiply, Add
      0001 FNMAC{S|D}{cond} Fd,Fn,Fm  Fd = -(Fn*Fm)+Fd   ;Multiply, Negate, Add
      0010 FMSC{S|D}{cond} Fd,Fn,Fm   Fd = +(Fn*Fm)-Fd   ;Multiply, Subtract
      0011 FNMSC{S|D}{cond} Fd,Fn,Fm  Fd = -(Fn*Fm)-Fd   ;Multiply, Negate, Sub
      0100 FMUL{S|D}{cond} Fd,Fn,Fm   Fd = +(Fn*Fm)      ;Multiply
      0101 FNMUL{S|D}{cond} Fd,Fn,Fm  Fd = -(Fn*Fm)      ;Multiply, Negate
      0110 FADD{S|D}{cond} Fd,Fn,Fm   Fd = Fn+Fm         ;Add
      0111 FSUB{S|D}{cond} Fd,Fn,Fm   Fd = Fn-Fm         ;Sub
      1000 FDIV{S|D}{cond} Fd,Fn,Fm   Fd = Fn/Fm         ;Divide
      1001 -Undefined-
      1010 -Undefined-
      1011 -Undefined-
      1100 -Undefined-
      1101 -Undefined-
      1110 -Undefined-
      1111 -Extension instructions-

VFP data-processing extension opcodes

      Fn   N cp10/cp11                  Instruction functionality
      0000 0 FCPY{S|D}{cond} Fd,Fm      Fd = Fm        ;Copy
      0000 1 FABS{S|D}{cond} Fd,Fm      Fd = abs(Fm)   ;Absolute
      0001 0 FNEG{S|D}{cond} Fd,Fm      Fd = -Fm       ;Negate
      0001 1 FSQRT{S|D}{cond} Fd,Fm     Fd = sqrt(Fm)  ;Square root
      001x x -Undefined-
      0100 0 FCMP{S|D}{cond} Fd,Fm      Fd-Fm     ;Compare
      0100 1 FCMPE{S|D}{cond} Fd,Fm     Fd-Fm     ;Compare, exception on quiet NaNs
      0101 0 FCMPZ{S|D}{cond} Fd        Fd-0      ;Compare
      0101 1 FCMPEZ{S|D}{cond} Fd       Fd-0      ;Compare, exception on quiet NaNs
      0110 x -Undefined-
      0111 0 -Undefined-
      0111 1 FCVT{DS|SD}{cond} Fd,Fm    Single <--> Double-precision conversion
      1000 0 FUITO{S|D}{cond} Fd,Im     Unsigned integer --> float
      1000 1 FSITO{S|D}{cond} Fd,Im     Signed integer --> float
      1001 x -Undefined-
      101x x -Undefined-
      1100 0 FTOUI{S|D}{cond} Id,Fm     Float --> unsigned integer
      1100 1 FTOUIZ{S|D}{cond} Id,Fm    Float --> unsigned integer, round to zero
      1101 0 FTOSI{S|D}{cond} Id,Fm     Float --> signed integer
      1101 1 FTOSIZ{S|D}{cond} Id,Fm    Float --> signed integer, round to zero
      111x x -Undefined-

cp10: FCVTDS Dd,Sm ;Double <-- Single
cp11: FCVTSD Sd,Dm ;Single <-- Double
Nocash syntax
The useless {S|D} and {DS|SD} suffixes are ommitted. FCVT is renamed to FMOV. F{UI|SI}TO{UI|SI}{Z} is renamed to FMOV{UI|SI}{Z}, with operand I0..I31 for the integer register.

ARM VFP Floating Point Load/Store Opcodes

VFP single register transfer instructions

      cp   opcode L Instruction name   Instruction functionality
      cp10 000    0 FMSR{cond} Sn,Rd   Sn = Rd        ;\Single-Precision or Integer
      cp10 000    1 FMRS{cond} Rd,Sn   Rd = Sn        ;/
      cp10 111    0 FMXR{cond} sys,Rd  Reg(Fn,N) = Rd ;\SystemReg (FPSID, etc.)
      cp10 111    1 FMRX{cond} Rd,sys  Rd = Reg(Fn,N) ;/  ;<-- or FMSTAT{cond}
      cp11 000    0 FMDLR{cond} Dn,Rd  Dn.31-0 = Rd   ;\LSW of Double-Precision
      cp11 000    1 FMRDL{cond} Rd,Dn  Rd = Dn.31-0   ;/
      cp11 001    0 FMDHR{cond} Dn,Rd  Dn.63-32 = Rd  ;\MSW of Double-Precision
      cp11 001    1 FMRDH{cond} Rd,Dn  Rd = Dn.63-32  ;/
      other's       -Undefined-

System Register encodings:

      Fn   N  System register
      0000 0  FPSID (New3DS: 410120b4h = VFPv2 with single AND double precision)
      0001 0  FPSCR      ;(FMSTAT opcode encodes as FMRX R15,FPSCR)
      0110 0? MVFR1                       ;\mpcore only
      0111 0? MVFR0                       ;/
      1000 0  FPEXC
      1001 0? FPINST                      ;\mpcore only
      1010 0? FPINST2                     ;/

VFP two register transfer instructions (VFPv2 and above)

      cp   L Instruction name               Instruction functionality
      cp10 0 FMSRR{cond} {Sm,Sm+1},Rd,Rn    Fm = Rn, (Fm+1) = Rd    ;XXX swapped?
      cp10 1 FMRRS{cond} Rd,Rn,{Sm,Sm+1}    Rn = Fm, Rd = (Fm+1)    ;XXX swapped?
      cp11 0 FMDRR{cond} Dm,Rd,Rn           Fm[31:0] = Rd, Fm[63:32] = Rn
      cp11 1 FMRRD{cond} Rd,Rn,Dm           Rd = Fm[31:0], Rn = Fm[63:32]

VFP load and store instructions

      PUW  L=0/1,cp10/cp11                             Registers transferred
      000  -Two-register transfer instructions-        -
      001  -Undefined-                                 -
      010  FSTM|FLDMIA{S|D|X}{<cond>} Rn,{Fd,Fd+1,..}  Multiple Registers
      011  FSTM|FLDMIA{S|D|X}{<cond>} Rn!,{Fd,Fd+1,..} Multiple Registers Increment
      100  FST|FLD{S|D}{<cond>} Fd, [Rn{,-offs*4}]     One register, -offs
      101  FSTM|FLDMDB{S|D|X}{<cond>} Rn!,{Fd,Fd+1,..} Multiple Registers Decrement
      110  FST|FLD{S|D}{<cond>} Fd, [Rn{,+offs*4}]     One register, +offs
      111  -Undefined-                                 -

FSTM/FLDM do transfer multiple words (with offs containing the number of words to be transferred, 1..32 for {S}, or an even number 2..32 for {D}.
VFP load/store multiple addressing modes

      Non-stacking mnemonic   Stacking mnemonic
      FLDMIA{S|D|X}           FLDMFD{S|D|X}     FPOP{S|D|X}
      FLDMDB{S|D|X}           FLDMEA{S|D|X}
      FSTMIA{S|D|X}           FSTMEA{S|D|X}
      FSTMDB{S|D|X}           FSTMFD{S|D|X}     FPUSH{S|D|X}

Nocash syntax
The useless {S|D} suffixes are ommitted, the weird {X} suffix is kept used to preserve weirdness.
Fancy {} brackets are omitted, LDM/STM must use square [Rn] brackets, the register list in LDM/STM is specified as Fx-Fz (rather than Fx,Fy,Fz).
All FMxxxx opcodes are renamed to FMOV{LSW|MSW}.
Weird STM/LDM{X} - for registers with unknown precision
The weird {X} mode is same as {D}, but with offset.bit0=1 (ie. with offs=3..33 instead of 2..32; and thereby actually transferring an unused dummy word).
The weird {X} mode is/was intended for registers with unknown content (eg. when pushing/popping registers without knowing if they contain integer/single/double precision values; which might be a problem with internal accumulators in the VFP unit).
The weird {X} mode was declared as "deprecated in ARMv6" in DDI 0100I, but later re-declared as required for "compatibility with future VFP implementations" in DDI 360F. However, unknown if there are/were/will be any such implementations that do require it.
For now, it should be best to use {D} mode instead of weird {X}. Probably even {S} should also work the same (if the endianess-based word-order doesn't matter).

3DS eMMC Partitions

The 3DS can have up to eight primary NCSD partitions, some of these partitions point to secondary MBR partition tables, each of those MBRs could have up to four child partitions (with FAT filesystems).
NAND structure

      Offset    Size      Name  _NCSD_partition_  AES Description
                                FS   crypt index  key
                                type type
      00000000h 200h                                  NCSD header
      00000000h 0B100000h       0x01 0x01  0x00   03h DSi MBR
      00004000h 200h?             -    -     -    -   Some Consoles: Dummy FAT16
      00012C00h 200h              -    -     -    11h New3DS FIRM keys
      00012E00h 08FB5200h twln                    03h DSi FAT16 File System, main
      09011A00h 020B6600h twlp                    03h DSi FAT12 File System, photo
      0B100000h 00030000h       0x04 0x02  0x01   07h AGB_FIRM GBA savegame
      0B130000h 00400000h firm0 0x03 0x02  0x02   06h Firmware partition
      0B530000h 00400000h firm1 0x03 0x02  0x03   06h Firmware partition (backup)
      0B930000h 2F5D0000h       0x01 0x02  0x04   04h Old3DS: MBR
      0B95CA00h 2F3E3600h nand                    04h Old3DS: FAT16 File System
      0B930000h 41ED0000h       0x01 0x03  0x04   05h New3DS: MBR
      0B95AE00h 41D2D200h nand                    05h New3DS: FAT16 File System

Physical Size

      Device  eMMC Chip                Size
      2DS     Toshiba ?                3AF00000h ;\943MB   ;uh, all unknown
      Old3DS  Toshiba ?                3AF00000h ;/        ;CID and chip names?
      2DS     ?                        3B000000h ;<-- 3AF00000h and up E3h-filled?
      2DS     Samsung ?                3BA00000h ;\954MB
      Old3DS  Samsung ?                3BA00000h ;/
      2DS     Samsung ?                4D800000h ;\1240MB
      New3DS  Samsung KLM4G1YE0C-B301  4D800000h ;/
      New3DS  Samsung ?                74800000h ;-1864MB
      2DS     Toshiba ?                76000000h ;\1888MB
      New3DS  Toshiba ?                76000000h ;/

Encryption
The NAND file system is encrypted using AES-CTR. The keyslot used for each partition is determined by the NCSD partition FS type and encryption type.
NAND sectors which were never written to contain plaintext 00h or FFh bytes.
None of the NAND partitions are normally accessible from the ARM11, except for twlp. CTR/TWL NAND FS can only be accessed when the exheader access control descriptor for those are enabled. Normally the CTR/TWL NAND descriptors are never enabled for retail ARM11 CXI processes. The ARM11 can only access "nand:/rw/" mounted as the nandrw archive, and "nand:/ro/" mounted as the nandro archive below.
eMMC 4000h (on some consoles) (empty 00h-filled on others)
On some 3DS systems (such as 3DS XL), there's a plaintext FAT16 boot record located at NAND offset 0x4000. This block does not exist for launch-day 3DS systems. This is the only plaintext block for this "partition".
That is, a 200h-byte VBR sector with string FAT16 (the actual FAT, Root, and Data sectors don't exist... and the Data clusters would probably overlap other partitions).
eMMC 12C00h (aka Sector 96h) (New3DS only) (empty FFh-filled on Old3DS)

      000h 10h   Used for generating Key X values for keyslot 15h and 18h
      010h 10h   Used for generating Key X values for keyslot 16h and 19h-1Fh ;v9.6
      020h 1E0h  Further constants (unused)

This 200h-byte sector contains New3DS keys, this entire sector is encrypted via AES-ECB with a console-unique keyX+keyY. The keyX+keyY for this is generated by the New3DS arm9bin-loader. Once the arm9bin-loader finishes decrypting this data, the keyX+keyY in the keyslot are then cleared, then the memory used for generating the keydata is disabled (after it finishes using it for TWL key init).
The decrypted sector is same on all New3DS consoles (except, retail-vs-debug are different):

      Decrypted 200h-bytes on Retail: 07h,29h,44h,38h, ..., 13h,63h,CFh,8Fh
      Decrypted 200h-bytes on Dev:    Unknown...

3DS CTR partition
The structure of nand/title appears to be exactly the same as SD, except savegames are stored under the nand/data/<ID0>/sysdata directory instead. The sub-directory name under nand/data is the SHA256 hash over the movable.sed keyY. This nand/data/<ID0> directory is the NAND equivalent of the "sdmc/Nintendo 3DS/<ID0>/<ID1>" directory, however the data contained here is stored in cleartext. The movable.sed keyY is only used for AES MACs for nand/data/<ID0>. The nand/data/<ID0>/extdata directory contains the shared extdata, and is structured exactly the same way as SD extdata.
DSi TWL partition
The structure of these TWL partitions is mostly the same as DSi, except tickets are stored in the CTR FAT FS. The twlp partition is exactly the same as DSi. The structure of twln/title is exactly the same as CTR NAND/SD, except the .cmd file is a cleartext file (this is likely a dummy file). The data directory under system titles' /title directory does not exist, this likely only exists for DSiWare. The directory names titleID-High used under twln/title is from DSi.
3ds:\__journal.nn_ (with system attribute)

      00000h 12    ID "LIAFEFAS1",0,0,0  (aka 1SAFEFAIL backwards)
      0000Ch 4     Total Filesize/200h (can be C0h=18000h or E0h=1C000h)
      00010h 4     Bytes 83h,3Eh,5Ch,89h or 86h,03h,0Fh,D7h (timestamp or so?)
      00014h 4     Value 01h (whatever)
      00018h ..    Zero
      001DCh 4     Value 03h (whatever)
      001E0h 20h   Whatever (maybe SHA256 on something) (3Fh,5Ch,AEh,20h,..)
      00200h 4     Value 06h (whatever)
      00204h 1F4h  Zero
      00400h 200h  Some FAT Directory sector with short filenames
      00600h 200h  Some FAT Allocation sector with FAT16 entries
      00800h 7C00h Zero
     Below can be at 08400h..17FFFh, or alternately at 04400h..1BFFFh:
      08400h 200h  Some FAT Directory sector with short filenames
      08600h 200h  Some FAT Allocation sector with FAT16 entries
      08800h F800h Random garbage, or encrypted sectors, or whatever

Unknown purpose, might be some debug log, or undo-info for handling incomplete FAT writes to the 3DS partition? If so, unknown if it's important to update/delete the journal file after manually changing FAT contents (to prevent the OS from corrupting/undoing the manual changes).
Unknown if there is a list of sector numbers for the 200h-byte sectors (maybe that list exists, but gets zerofilled after completion?), unknown why there are only short filenames (normally there should be also long/lowercase names).

3DS NCSD Format

NCSD format is used for internal eMMC storage & for 3DS ROM cartridges. The NCSD can contain up to 8 partitions.

     For eMMC, the partitions are:
      Part Type     Content
      0    MBR      DSi MBR (with two FAT filesystems, FAT16+FAT12)
      1    GBA-SAVE GBA savegame (temporary storage, used on power-off in GBA mode)
      2    FIRM     Firmware partition (firm0)
      3    FIRM     Firmware partition (firm1) (backup copy, same as above)
      4    MBR      3DS MBR (with one FAT filesystem, FAT16)
      5-7  -        Unused
     For 3DS ROM Cartridges (aka CCI images), the partitions are:
      Part Type     Content
      0    NCCH     Executable Content (CXI)
      1    NCCH     E-Manual (CFA)
      2    NCCH     Download Play Child container (CFA) (if any)
      3-5  -        Unused
      6    NCCH     New3DS System Update Data (CFA) (if any) ;\aka firmware updates
      7    NCCH     Old3DS System Update Data (CFA)          ;/

Blurb
There are two known specialisations of the NCSD container format:

      - The CTR Cart Image (CCI) format (CCI is the format of game ROM images)
      - The 3DS' raw NAND format

CTR System Update (CSU) is a variant of CCI, where the only difference is in the file extension (uh, that is the file extension of a ROM-image that needs to be copied to a dev flashcard or so?). This is used with developer System Updates and associated Tools.
The format of partitions can be determined from the partition FS flags (normally these are zero for CCI/CSU NCSD Images) (uh, what/where is "FS flags"?).
NCSD header

      000h 100h    RSA-2048 SHA-256 signature of the NCSD header (including MBR!)
      100h 4       ID "NCSD"
      104h 4       Size of the NCSD image (in media units)
      108h 8  ?    Media ID
      110h 8*1     Partitions Type  (0=NCCH or Unused, 1=MBR, 3=FIRM, 4=GBA-SAVE)
      118h 8*1     Partitions Crypt (0=NCCH or Unused, 1=DSi, 2=3DS, 3=New3DS)
      120h 8*(4+4) Partitions Offset & Size (in media units)
     For eMMC:
      160h 25h Zerofilled
      185h 1   Unknown (04h)
      186h 6   Zerofilled
      18Ch 1   Unknown (01h)
      18Dh 1   Zero
      18Eh 1   Media Unit Size (200h SHL N) (usually 00h, aka 200h-bytes)
      18Fh 2Fh Zerofilled (unencrypted, despite of below)
      1BEh 42h Encrypted MBR partition-table, for the two DSi partitions
                 (key-data used for this keyslot is console-unique).
     For ROM carts:
      160h 20h Exheader SHA-256 hash (uh, really?)                     (usually 0)
      180h 4   Additional header size (uh, does that mean "Exheader"?) (usually 0)
      184h 4   Sector zero offset (whatever, in whatever units, usually 0)
      188h ..  Partition Flags (uh, why called "flags" and why "partition"?)
      188h 1   Backup Write Wait Time (The time to wait to write save to backup
                 after the card is recognized (0-255 seconds)). NATIVE_FIRM loads
                 this flag from the gamecard NCSD header starting with 6.0.0-11.
      189h 1   unknown, maybe related to below "Save Crypto"?
      18Ah 1   unknown, ?
      18Bh 1   Media Card Device (1=NOR Flash, 2=None, 3=BT) (SDK 3.X+)
      18Ch 1   Media Platform Index (1=CTR)
      18Dh 1   Media Type Index (0=InnerDevice, 1=Card1, 2=Card2, 3=ExtendedDevice)
      18Eh 1   Media Unit Size (200h SHL N)
      18Fh 1   Media Card Device (1=NOR Flash, 2=None, 3=BT) (Only SDK 2.X)
      190h 40h Partition ID table (8x8 bytes)
      1D0h 20h Reserved
      1F0h 0Eh Reserved?
      1FEh 1   Support for this was implemented with 9.6.0-X FIRM.
                 Bit0=1 enables using bits 1-2, it's unknown what these two
                 bits are actually used for (the value of these two bits get
                 compared with some other value during NCSD
                 verification/loading).
                 This appears to enable a new, likely hardware-based,
                 antipiracy check on cartridges.
      1FFh 1   Support for this was implemented with 9.6.0-X FIRM, see below
                 regarding save crypto.

NCSD Signature
The RSA pubk used for gamecard NCSD is stored in ITCM (what/wherefrom?).
The RSA pubk used for NAND NCSD is stored in "Process9 .(ro)data instead of ITCM". Uh, shouldn't that key (also?) be in bootrom?
Partition Flags (In Terms of Save Crypto Determination) (uh, Save what?)
Note: Byte 01h,03h,07h do probably refer to NCSD[189h,18Bh,18Fh].
Note: flag[1,3,7] do probably ALSO refer to NCSD[189h,18Bh,18Fh].
Note: partitionflag[1,3,7] do MAYBE ALSO refer to NCSD[189h,18Bh,18Fh]?

      Byte   Description
      01h    Starting with 6.0.0-11 NATIVE_FIRM will use this flag to determine
               the gamecard savegame keyY method, when flag[3] is set.
               00h = 2.0.0-2 hashed keyY,
               01h = new keyY method implemented with 6.0.0-11.
               0Ah = implemented with 9.3.0-X. On Old3DS this is identical to
                 the 2.2.0-4 crypto. On New3DS this is identical to the 2.2.0-4
                 crypto, except with New3DS-only gamecard savedata keyslots.

Starting with 9.6.0-X FIRM, Process9 now sets <savecrypto_stateval> to partitionflag[1] + <the u8 value from NCSD+0x1FF>, instead of just setting it to partitionflag[1].

      03h    Support for this flag was implemented in NATIVE_FIRM with 2.0.0-2.
               When this flag is set the hashed gamecard savegame keyY method is
               used, this likely still uses the repeating-CTR however.
               With 6.0.0-11 the system will determine the gamecard savegame keyY
               method via flag[1], instead of just using the hashed keyY via this
               flag.
      07h    This flag enables using the hashed gamecard savegame keyY method,
               support for this flag was implemented in NATIVE_FIRM with 2.2.0-4.
               All games with the NCSD image finalized since 2.2.0-4 (and contains
               2.2.0-4+ in the system update partition) have this flag set, this
               flag also enables using new CTR method as well.

Starting with 9.6.0-X FIRM, Process9 will just write val0 to a state field then return 0, instead of returning an error when the save crypto type isn't recognized. This was the *only* actual functionality change in the Old3DS Process9 function for gamecard savedata crypto init.
Card Info Header - uh, maybe this is the "Exheader" aka "Additional header"?

      Offset Size  Description
      200h   4     CARD2: Writable Address In Media Units (For 'On-Chip' Savedata)
                   CARD1: Always FFFFFFFFh.
      204h   4     Card Info Bitmask
      208h   108h? Reserved1
      300h   4     Unknown (1DD7AA00h)
      ...    ..
      310h   2     Title version
      312h   2     Card revision
      ...    ..
      320h   8     Title ID for CVer USA (000400db00017202h) (even so in JPN cart)
      328h   ?     Unknown (1022h)
      208h?? CEEh? Reserved2
      1000h  10h   Card seed AES-KeyY (first u64 is Media ID (same as first NCCH
                     partitionId))
      1010h  10h   Encrypted card seed (AES-CCM, keyslot 3Bh for retail cards,
                     see CTRCARD_SECSEED)
      1020h  10h   Card seed AES-MAC
      1030h  0Ch   Card seed AES-IV
      103Ch  C4h   Reserved3
      1100h  100h  Copy of first NCCH header (excluding RSA signature)
     Development Card Info Header Extension:
     Unknown how to read from 1200h..3FFFh. When trying to do so on retail card:
     Encrypted read (cmd BFh) does merely return random garbage at 1200h..3FFFh.
     Unencrypted read (cmd 82h) can read from 1000h only (though MAYBE it can
     read MULTIPLE blocks from 1000h upwards?)
     Below says something about NTR cmd 90h or CTR cmd 90h or A2h, but that
     refers to getting the 32bit Chip ID, not to header data at 1200h and up.
      1200h  200h  CardDeviceReserved1
      1400h  10h   TitleKey (whever that is... something alike as in tickets?)
      1410h  F0h   CardDeviceReserved2

Note that a particular(=which?) flashcard vendor puts what many(=who?) refer to as "private headers"(=what?) here in place of actual development card information. This(=which?) header is constituted(=whut?) by a cartridge-unique Id obtained from pxi:ps9::GetRomId(=what?) and the title-unique cart ID (identical for all carts of the same title; can be retrieved using the NTR gamecard protocol command 90h or through the CTR protocol commands 90h or A2h) (uh, actually, that is the Chip ID, not a "title-unique cart ID" thing).
Tools
ctrtool - (CMD) (Windows/Linux) Parsing NCSD files
3DSExplorer - (GUI) (Windows Only) Parsing NCSD files

3DS FIRM Format

File format for the 3DS' Firmware, it contains up to four 'sections' of data comprising the ARM9 and ARM11 kernels, and some fundamental processes.
The firmware sections are not encrypted.
The ARM9 section contains the ARM9 kernel (and loader) and the Process9 NCCH (which is the only process run in user mode on the ARM9). The ARM11 sections contain the ARM11 kernel (and loader), and various ARM11 process NCCHs. For NATIVE_FIRM/SAFE_MODE_FIRM these ARM11 processes are sm, fs, pm, loader, and pxi. Normally the 4th section is not used. The code loaded from FIRM is constantly running on the system until another FIRM is launched. The ARM11 kernel is hard-coded to always decompress the ExeFS .code of embedded ARM11 NCCHs without checking the exheader compression bit.
FIRM Format can exist in two locations:

      As raw eMMC sectors (defined in the NCSD Header of the eMMC storage)
      As .firm files (in NCCH .app files, in the "\title\00040138" firmware folder)

And, in Wifi-Flash and NTRCARDs (that's both only for repair/unbricking).
FIRM Header

      000h  4       ID "FIRM"
      004h  4       Boot priority (0=Normal/Lowest)
      008h  4       ARM11 Entrypoint (usually 1FFxxxxxh, aka AXI WRAM.. or DSP?)
      00Ch  4       ARM9 Entrypoint  (usually 080xxxxxh, aka ARM9-only RAM)
      010h  30h     Reserved (0)
      040h  30h     Firmware Section Header 1 (usually several NCCH's with ExeFS)
      070h  30h     Firmware Section Header 2 (usually ARM11 code)
      0A0h  30h     Firmware Section Header 3 (usually ARM9 code & Process9 NCCH)
      0D0h  30h     Firmware Section Header 4 (often unused, zerofilled)
      100h  100h    RSA-2048 SHA-256 signature of the FIRM header

The RSA signature is checked when bootrom/Process9 are doing FIRM-launch (with the public key being hardcoded in each). The signature is not checked when installing FIRM to the NAND firm0/firm1 partitions.
Firmware Section Headers

      000h  4       Byte offset      (relative to begin of FIRM header)
      004h  4       Physical address where the section is loaded to
      008h  4       Byte-size    (or 0=None)
      00Ch  4       Copy-method (0=NDMA, 1=XDMA, 2=CPU mem-copy)
                                (0=ARM9/WRAM, 1=ARM11/AXI/VRAM, 2=?)
      010h  20h     SHA-256 Hash of Firmware Section

Note on Copy-method: Process9 ignores this field. Boot9 doesn't immediately throw an error when this isn't 0..2. In that case it will jump over section-data-loading which then results in the hash verification with the below hash being done with the hash already stored in the SHA hardware.
FIRM Load Areas
Common Load areas are:

      08006000h 0.9M  ARM9-WRAM  (common for ARM9 code) (not first/last some bytes)
      18000000h 6.0M  VRAM       (eg. used by GBA/DSi firmwares)
      1FF00000h 0.5M  DSP Memory (eg. used by FIRM0)
      1FF80000h 0.5M  AXI RAM    (common for ARM11 code)

With that areas, a FIRM file can be max 7.9Mbyte (if it is loaded as file, the default size of the firm0/firm1 partitions is only 4Mbyte each).
There is a blacklist in bootrom preventing some memory regions:

      07FFB800h..07FFFBFFh  ARM9 ITCM part (otp, mbr, keys...)
      FFF00000h..FFF02FFFh  ARM9 DTCM (first 3000h) (arm9 data)
      FFF03000h..FFF03FFFh  ARM9 DTCM (last 1000h) (arm9 stack)
      080F8000h..080FFFFFh  ARM9 WRAM (last 8000h) (rom card related?)
      08000000h..0800003Fh  ARM9 WRAM (first 40h) (exception vectors, etc)
      20000000h..27FFFFFFh  FCRAM (whole 128MB)
      FFF00000h..1FFFFFFFh  Bugged (size of that area is negative/nonsense)

Moreover, the bootrom doesn't have Main RAM and New3DS memory enabled. And, the bootrom PU has also disabled some memory areas (though those might pass when using DMA for loading?).

3DS FIRM Encryption

FIRMs are more or less unencrypted, except that they are stored in encrypted memory:

     - FIRM bootcode is stored in an encrypted partition (with the usual eMMC
       encryption; using a different keyslot than FAT partitions though)
     - FIRMs for GBA/DSi/SafeMode are stored in NCCHs files (with the eMMC
       filesystem encryption; and usually with NCCH[18Fh].bit2=1, ie. no further
       encryption in NCCH ExeFS)

Apart from that, FIRMs are having a RSA signature (which can be broken via sighax).
Self-decrypting New3DS FIRMs
New3DS FIRMs are containing self-decrypting ARM9 code (there is no requirement to do that in homebrew FIRMs, it's basically a nag feature, making it slightly more difficult to disassemble or patch the official FIRMs).
The ARM9 block (the FIRM section with the ARM9 entrypoint) looks as so:

      000h 10h  Encrypted Key_15h_x (same for all FIRM's)
      010h 10h  AES-CTR Key Y   ;\for decrypting the code at 800h and up
      020h 10h  AES-CTR IV      ;/(these are different in each FIRM version)
      030h 8    Size of encrypted binary as decimal ASCII string (eg. "546048",0,0)
      038h 8    Padding (FFh-filled)
      040h 10h  Encrypted zeroes (won't boot if decrypted data is nonzero)
      050h 7B0h Padding (FFh-filled)                        ;-before version 9.5.0
      050h 10h  Some kind of unused debug info              ;\
      060h 10h  Encrypted Key_16h_x                         ; version 9.5.0 and up
      070h 790h Padding (00h-filled)                        ;/
      800h ..   Encrypted ARM9-binary (size as from [030h], eg. 546048 bytes)
      ...  ..   Code: Unencrypted ARM9 bootstub
      ...  10h  Data: Seed value for key 18h..1Fh       (eg. A4h,8Dh,E4h,F1h,..)
      ...  10h  Data: Key_15h_y (for encrypted zeroes)  (eg. 25h,91h,2Ah,C1h,..)
      ...  4    Data: Entrypoint to decrypted ARM9 code (eg. 08xxxxxxh)
      ...  1+3  Data: Some flag byte (initially zero, and FFh-filled padding)
      ...  ..   Padding to 200h-byte boundary (zerofilled)
      NOTE: Later FIRMs do reportedly have another Seed value for key 19h-1Fh,
      which is probably inserted somewhere(?) in the above data area.

Alongsides with the keys stored at begin & end of the above ARM9 block, the decryption code use two more sources:

      SHA256 computed across first 90h bytes of encrypted OTP memory
      Data read from eMMC address 12C00h (aka eMMC sector number 96h)

Aside from doing the self-decryption, the bootstub does additionally initialize keyslots 15h, 16h, and 18h..1Fh (some of those are being used elsewhere).
New3DS FIRM Self-decryption and Key Init

      sha256(dst=sha_otp, src=10012000h, srclen=90h)             ;\load key
      key_11h_x = sha_otp[00h..0Fh]                              ; sector and
      key_11h_y = sha_otp[10h..1Fh]                              ; decrypt it
      Read_eMMC(dst=mmc_buf, src=12C00h, len=200h)               ; via OTP
      Decrypt_AES_ECB(key=11h, srcdst=mmc_buf, len=200h)         ;/
      key_11h_normal = mmc_buf[000h..00Fh]
      seed = const(A4h,8Dh,E4h,F1h,..)  ;from firm9+xxx          ;\
      AES_ECB_Decrypt(key=11h, dst=temp, src=seed, len=10h)      ; key 18h
      key_18h_x = temp[00h..0Fh]                                 ;/
      Decrypt_AES_ECB(key=11h, dst=temp, src=firm9+00h, len=10h) ;\
      key_15h_x = temp[00h..0Fh]                                 ;
      key_16h_x = temp[00h..0Fh]                                 ; key 15h/16h
      if ver>=v9.6 then key_11h_normal = mmc_buf[010h..01Fh]     ;
      Decrypt_AES_ECB(key=11h, dst=temp, src=firm9+60h, len=10h) ;
      if ver>=v9.5 then key_16h_x = temp[00h..0Fh]               ;/
      BigEndianIncrement(seed)                                   ;\
      if ver>=v9.6 then seed=OtherConst(??)  ;XXX unknown        ;
      for i=19h to 1Fh                                           ; key 19h-1Fh
        AES_ECB_Decrypt(key=11h, dst=temp, src=seed, len=10h)    ;
        key_(i)_x = temp[00h..0Fh]                               ;
        BigEndianIncrement(seed)                                 ;/
      key_16h_y = firm9+10h                                      ;\
      aes_iv = firm9+20h                                         ; decrypt
      size=asc2bin(firm9+30h)                                    ; firm code
      Decrypt_AES_CTR(key=16h, src=dst=firm9+800h, len=size)     ;/
      key_15h_y = const(25h,91h,2Ah,C1h,..)  ;from firm9+xxx     ;\verify
      Decrypt_AES_ECB(key=15h, dst=temp, src=firm9+40h, len=10h) ; zeroes
      if temp[00h..0Fh]<>0 then error                            ;/

As shown above, there are three revisions (v8.1 being the original New3DS firmware, and small changes made in v9.5 and v9.6). The versions before v9.5 didn't actually touch keyslot 16h (the key_16h_x/y values shown above were written to keyslot 15h). The versions before v9.6 did produce other keys for keyslot 19h-1Fh (but they were never used, so one will only need the newer v9.6 values; which require finding a yet unknown seed value though).
Terror
Caution: The FIRM key init description on 3dbrew FIRM page is incomplete, confusing, irrelevant, and simply mind blowing (the description won't make any sense at all without simultaneously looking at the disassembled firmware code; or perhaps looking at above pseudo code).

3DS FIRM Versions

New3DS ARM9 kernel - weird blurb
The only actual code-difference for the Old3DS/New3DS ARM9-kernels' crt0, besides TWL AES / 10012000h (=OTP?) related code, is that the New3DS ARM9-kernel writes 1 to REG_EXTMEMCNT9 (=CFG9_EXTMEMCNT9?) in the crt0 (unknown what crt0 means, elsewhere it's said that "0xffff8000 is crt0", although that does actually more look like a ROM address).
New3DS Process9
The following is all of the differences for Old3DS/New3DS Process9 with 9.3.0-X:
The FIRM-launch code called at the end of the New3DS proc9 main() has different mem-range checks.
In the New3DS proc9, the v6.0/v7.0 keyinit function at the very beginning (before the original code) had additional code added for setting CTRNAND keyslot 0x5, with keydata from .data. After setting the keyY, the keyY in .data is cleared.
In New3DS proc9, the functions for getting the gamecard crypto keyslots / NCCH keyslot can return New3DS keyslots when New3DS flags (NCSD/NCCH) are set.
The code/data for the binary near the end of arm9mem is slightly different, because of memory-region sizes.
The only difference in .data (besides the above code binary) is that the New3DS proc9 has an additional 0x10-byte block for the keyslot 0x5 keyY, see above.
Variations
There exists different official firmwares for the 3DS: The default one (NATIVE_FIRM) is used to run all 3DS content and boots by default, while backwards compatibility is handled by TWL_FIRM and AGB_FIRM. There furthermore is a rescue mode provided by SAFE_MODE_FIRM.
NATIVE_FIRM
NATIVE_FIRM is the FIRM which is installed to the NAND firm partitions, which is loaded by bootrom.
Version history:

      System
      version           old 3DS
                        title version   old 3DS
                       /                hex title
                      /                 contentID     Kernel/FIRM
                     /        ________/               version (old
                    /        /         ______________ 3DS/new 3DS)  FIRM
                   /        /         /    ________________________ ARM11-sysmodule
                  /        /         /    /                         Product Code
      Factory    v0      00      2.3-0   - ;Factory FIRM, titleID 00040001-00000002
      Pre-1.0    -       -       2.23-X  - ;Referenced in v1.0 Home Menu NCCH hdr
      1.0.0-0    v432    00      2.27-0  -               ?  ?   2011?
      1.1.0-     v1472   02      2.28-0  -               -  -   2011?
      2.0.0-     v2516   09      2.29-7  -               -  -   2011?
      2.1.0-3    v3553   0B      2.30-18 0608builder     ?  ?   2011?
      2.2.0-X ?  v4595   0F      2.31-40 0909builder     ?  ?   2011?
      3.0.0-     v5647   18      2.32-15 1128builder     -  -   2011?
      4.0.0-7    v6677   1D      2.33-4  0406builder     ?  ?   2012
      4.1.0-     v7712   1F      2.34-0  0508builder     -  -   2012?
      5.0.0-11   v8758   25      2.35-6  0228builder     ?  ?   2013
      5.1.0-11   v9792   26      2.36-0  0401builder     ?  ?   2013
      6.0.0-11   v10833  29      2.37-0  0520builder     17 Jun 2013 ;Non-US: -12
      6.1.0-11   v11872  2A      2.38-0  0625builder     27 Jun 2013 ;Non-US: -12
      7.0.0-13   v12916  2E      2.39-4  1125builder     09 Dec 2013
      7.2.0-17   v13956  30      2.40-0  0404builder     12 May 2014
      8.0.0-18   v15047  37      2.44-6  0701builder     07 Jul 2014
      8.1.0-0 ?  -       -       2.45-5  -               26 Sep 2014 ;New3DS Launch
      9.0.0-20   v17120  38      2.46-0  0828builder     06 Oct 2014
      9.3.0-21   v18182  3F      2.48-3  1125builder     08 Dec 2014
      9.5.0-22   v19216  40      2.49-0  0126builder     02 Feb 2015
      9.6.0-24   v20262  49      2.50-1  0311builder     23 Mar 2015
      10.0.0-27  v21288  4B      2.50-7  0812builder     08 Sep 2015
      10.2.0-28  v22313  4C      2.50-9  1009builder     19 Oct 2015
      10.4.0-29  v23341  50      2.50-11 1224builder     18 Jan 2016
      11.0.0-33  v24368  52      2.51-0  0406builder     09 May 2016
      11.1.0-34  v25396  56      2.51-2  0805builder     13 Sep 2016
      11.2.0-35  v26432  58      2.52-0  1015builder     24 Oct 2016
      11.3.0-36  v27476  5C      2.53-0  0126builder     06 Feb 2017
      11.4.0-37  v28512  5E      2.54-0  0314builder     10 Apr 2017
      11.8.0-41  v29557  64      2.55-0  0710pseg-ciuser 30 Jul 2018
      11.12.0-44 v30593  66      2.56-0  1021pseg-ciuser 04 Nov 2019
      11.13.0-45 ?       ?       ?       ?               02 Dec 2019

Note: The above "builder" strings seem to be the actual Month/Day built-date.
SAFE_MODE_FIRM
SAFE_MODE is used for running the System Updater. SAFE_MODE_FIRM and NATIVE_FIRM for the initial versions are exactly the same, except for the system core version fields.
TWL_FIRM
TWL_FIRM handles DS(i) backwards compatibility.
The 3DS-mode ARM9 core seems to switch into DSi-mode (for running DSi-mode ARM9 code) by writing to a PDN register (this changes the memory layout to DSi-mode / etc, therefore this register poke *must* be executed from ITCM). This is the final 3DS-mode register poke before the ARM9 switches into DSi-mode. DS(i)-mode ARM7 code is run on the internal ARM7 core, which is started up during TWL_FIRM boot. Trying to read from the exception-vector region (address 0x0) under this DSi-mode ARM7 seems to only return 0x00/0xFF data. Also note that this DSi-mode ARM7 runs code (stored in TWL_FIRM) which pokes some DSi-mode registers that on the DSi were used for disabling access to the DSi bootROMs, however these registers do not affect the 3DS DSi-mode ARM9/ARM7 "bootrom" region (exceptionvector region + 0x8000) at all.
For shutting down the system, TWL_FIRM writes MCU[20h]=08h. For returning to 3DS-mode, TWL_FIRM writes to MCU[20h]=04h to trigger a hardware system reboot.
The TWL_FIRM ARM11-process includes a TWL bootloader, see here(?) and here(?) for details.
TWL_FIRM verifies all TWL RSA padding with the following. This is different from the DSi "BIOS" code.
The first byte must be 0x0.
The second byte must be 0x1 or 0x2.
Executes a while(<value of byte at current pos in RSA message>). When the second_byte in the message is 0x1, the byte at curpos must be 0xFF (otherwise the non-zero value of the byte at curpos doesn't matter). This loop must find a zero byte before offset 0x7F in the message otherwise an error is returned.
Returns an address for msg_curpos+1.
totalhashdatasize = rsasig_bytesize - above position in the message for the hashdata. The actual "totalhashdatasize" in the RSA message must be <= <expected hashdata_size>(0x74 for bootloader). Uh, <=<>()??? The TWL_FIRM code copies the RSA "hashdata" to the output buffer, using the actual size of the RSA "hashdata".
AGB_FIRM
AGB_FIRM handles running GBA VC titles. The ARM9 FIRM section for TWL_FIRM and AGB_FIRM are exactly the same (for TWL_FIRM and AGB_FIRM versions which were updated with the same system-update).

3DS FIRM Launch Parameters

FIRM Launch Parameters
The FIRM-launch parameters structure is located at FCRAM+0, size 0x1000-bytes. The ARM11-kernel copies this structure elsewhere, then clears the 0x1000-bytes at FCRAM+0. It will not handle an existing structure at FCRAM+0 if CFG_BOOTENV is zero. The ARM9 kernel writes some values about the boot environment to AXI WRAM during init to enable this.
Note: it seems NATIVE_FIRM ARM11-kernel didn't parse this during boot until 3.0.0-X?

      000h 300h unknown/unspecified (probably as on DSi?)
      300h 100h 'TLNC' block created by TWL applications, handled by NS for
                  backwards-compatibility purposes. See here for more info
      400h 4    Flags
      404h 0Ch  unknown/unspecified
      410h 0Ch  This is used for overriding the FIRM_* fields in
                  Configuration_Memory, when the flag listed below is set,
                  in the following order (basically just data-copy from here
                  to 0x1FF80060): "FIRM_?", FIRM_VERSIONREVISION,
                  FIRM_VERSIONMINOR, FIRM_VERSIONMAJOR, FIRM_SYSCOREVER,
                  and FIRM_CTRSDKVERSION
      41Ch ..   unknown/unspecified
      438h 4    The kernel checks this field for value 0xFFFF, if it matches
                  the kernel uses the rest of these parameter fields,
                  otherwise FIRM-launch parameters fields are ignored by
                  the kernel
      43Ch 4    CRC32 across [400h..53Fh] with [43Ch]=zero
                  When invalid the kernel clears the entire buffer used for
                  storing the FIRM-params, therefore no actual FIRM-params are
                  handled after that
      440h 10h  Titleinfo Program Info, used by NS during NS startup, to
                  launch the specified title when the below flag is set
      450h 10h  Titleinfo Program Info. This might be used for returning
                  to the specified title, once the above launched title
                  terminates?
      460h 4    Bit0: 0 = titleinfo structure isn't set,
                      1 = titleinfo structure is set
      464h ..   unknown/unspecified
      480h 20h  Can be set via buf1 for APT:SendDeliverArg/APT:StartApplication
      4A0h 10h  Can be set by NSS:SetWirelessRebootInfo
      4B0h 14h  SHA1-HMAC of the banner for TWL/NTR titles. This can be set
                  by NSS:SetTWLBannerHMAC
      4C4h ..   unknown/unspecified
      500h 40h  This is used by APT:LoadSysMenuArg and APT:StoreSysMenuArg
      540h ..   unknown/unspecified
      D70h 290h Config data struct for LGY FIRM

Flags from offset 0x400:

      +00h    1       This can be used for overriding the default FCRAM
                        memory-regions allocation sizes (APPLICATION, SYSTEM, and
                        BASE). The values for this is the same as
                        Configmem-APPMEMTYPE. Values 0-1 are handled the same way
                        by the kernel. However for NS, 0=titleinfo structure for
                        launching a title isn't set, while non-zero=titleinfo
                        structure is set.
      +01h    3       Setting bit0 here enables overriding the FIRM_* fields in
                        Configuration_Memory.

Config struct for booting LGY FIRMs from offset 0xD70:

      000h 1    Config block 0x30000
      001h 1    Config block 0x70001
      002h 1    System language (Config block 0xA0002)
      003h 1    Region from SecureInfo ("pseudo-block" 0x140000 in LGY FIRM)
      004h 0Fh  Serial number from SecureInfo ("pseudo-block" 140001h in LGY FIRM)
      013h 1    Config block 0x100002
      014h 10h  Config block 0x100003
      024h 2    Config block 0x100000
      026h 1    Cleared to zero
      027h 1    Cleared to zero
      028h 94h  Config block 0x100001
      0BCh 2    Config block 0x50000
      0BEh 2    Config block 0x50001
      0C0h 38h  Config block 0x50002
      0F8h 20h  Config block 0x50004
      118h 134h Config block 0x20000
      24Ch 10h  Config block 0x40000
      25Ch 1Ch  Config block 0x40001
      278h 4    Cleared to zero
      27Ch 4    Cleared to zero
      280h 8    Config block 0x30001
      288h 2    CRC16 over the above fields from offset 0x0, size 0x288,
                  if not valid, LGY FIRM uses dummy data from .(ro)data
      28Ah 2    If non-zero, the size (below) is hardcoded (currently) to
                  value 0x288, otherwise the size field below is used
      28Ch 4    Value 0x288 (size used for verifying the CRC16)

"Cleared to zero" fields above are not read at all by LGY FIRM.

3DS NCCH Format

NCCH (Nintendo Content Container Header) (in .app files)
This format is used to store the content of any installed title. There are two NCCH variants:

      CXI aka CTR Executable Image, with ARM11 code
      CFA aka CTR File Archive, with data only

The CXI/CFA format is structured in the following order:

      NCCH header                                                  (unencrypted)
      Exheader (CXI only)                                          (encrypted)
      Logo (5.0.0-11 and up)                                       (unencrypted)
      SDK Strings (aka plain binary region) (optional, CXI only)   (unencrypted)
      ExeFS filesystem (optional) - ARM11 code (CXI), icon/banner  (encrypted)
      RomFS filesystem (optional) - Used for external file storage (encrypted)

User-executable Tools (eg. System Settings) do have two NCCH .app files: One with the program .code, and one with the data manual. Internal System Modules (eg. MCU driver) have only one .app file (with program .code, without manual).
NCCH Header

      000h 100h RSA-2048 SHA-256 signature of the NCCH header
      100h 4    ID "NCCH"
      104h 4    Content size, in media units (1 media unit = 200h bytes)
      108h 8    Partition ID (usually same as Program ID, or weird stuff...?)
      110h 2    Maker code (3030h)
      112h 2    Version (0000h=Normal/Data?, 0001h=Weird?, 0002h=Normal/Code?)
      114h 4    SEEDDB Checksum (see NCCH Encryption chapter) (firmware 9.6.0)
      118h 8    Program ID (aka Title ID)
      120h 10h  Reserved
      130h 20h  Logo Region SHA-256 hash (5.0.0-11 and up)
      150h 10h  Product code ("CTR-x-xxxx") (for CFA: always "CTR-P-CTAP"?)
      160h 20h  Extended header SHA-256 hash (SHA256 of 2x Alignment Size... uh?)
      180h 4    Extended header size minus 400h, in bytes (usually 400h) (0=None)
      184h 4    Reserved
      188h ..   "Flags" (see below) (aka "ncchflag[0..7]")
      188h 3    Unknown (zero)
      18Bh 1    Crypto 2nd Keyslot (00h=None, 01h=Key25h, 0Ah=Key18h, 0Bh=Key1Bh)
      18Ch 1    Content Platform   (01h=CTR=3DS, 02h=Snake=New3DS)
      18Dh 1    Content Type Bit-masks: Data=0x1, Executable=0x2, SystemUpdate=0x4,
                  Manual=0x8, Child=(0x4|0x8), Trial=0x10.
                  When 'Data' is set, but not 'Executable', NCCH is a CFA.
                  Otherwise when 'Executable' is set, NCCH is a CXI.
      18Eh 1    Content Unit Size (200h SHL N)   ;uh, NOT? same as "media units"?
      18Fh 1    Flags Bit0=FixedKey, Bit1=NoMountRomFs, Bit2=NoCrypto, Bit5=NewKeyY
      190h 4    Plain region offset, in media units
      194h 4    Plain region size, in media units
      198h 4    Logo Region offset, in media units ;\For applications built with
      19Ch 4    Logo Region size, in media units   ;/SDK 5+ (5.0.0-11 and up)
      1A0h 4    ExeFS offset, in media units
      1A4h 4    ExeFS total size, in media units
      1A8h 4    ExeFS header size, in media units (for SHA256 at [1C0h])
      1ACh 4    Reserved
      1B0h 4    RomFS offset, in media units
      1B4h 4    RomFS total size, in media units
      1B8h 4    RomFS header size, in media units (for SHA256 at [1E0h])
      1BCh 4    Reserved
      1C0h 20h  ExeFS superblock SHA-256 hash
      1E0h 20h  RomFS superblock SHA-256 hash

All of the hashes stored in this NCCH header are over the cleartext data.
Given offsets are based on the start of the file.
Extended header
The extended header contains additional information regarding/restricting access control.
3DS NCCH Extended Header
Logo
3DS NCCH Logo
Plain binary region (SDK strings) (CXI only)
This region contains several zero-terminated ASCII strings (usually in form "[SDK+Blah:Blahblah]",00h).

      "The version used for the "FIRMWARE" tag (what?) is the kernel/FIRM
      version, this version can also be stored in the exheader "kernel release
      version" ARM11 kernel descriptor field. As of 2.2.0-X the NATIVE_FIRM
      kernels check the CXI exheader "kernel release version" field, if it is
      stored in the CXI exheader. If the kernel/FIRM version specified by this
      field is higher than the version of the running NATIVE_FIRM, the kernel
      will return error-code D9001413h."

Uh, all that blurb seems to say that... the SDK string is irrelevant - and if there's anything relevant, then it's the descriptor, but not/never the SDK string?
ExeFS and RomFS (Filesystems)
3DS NCCH ExeFS
3DS NCCH RomFS
Both ExeFS and RomFS are designed as read-only filesystems (in lack of a FAT, changing filesizes would require to relocate all following files).
Encryption (for Exheader, ExeFS, and RomFS)
3DS NCCH Encryption
Region Locking
The region-locking info checked by home menu is stored in the "icon" file in ExeFS.
RSA
CFAs NCCH header signature uses a fixed RSA public key.
CXIs NCCH header signature uses the RSA public key stored in the Exheader (whereof, that part of the Exheader is signed via another RSA key).
Tools
ctrtool - (CMD) (Windows/Linux) Parsing and decrypting (debug only) NCCH files

3DS NCCH Extended Header

The NCCH Exheader contains information for the .code file in the ExeFS (the .code file itself has no file header, and contains only raw code/data).
The Exheader exists only if NCCH[180h]>0. That is, it does exist for NCCH's with ExeFS .code file. For some reason ExeFS .firm does also have Exheader (but unknown if it's used for anything). Whilst E-Manuals have only RomFS, without ExeFS, and without Exheader.
NCCH Extended Header (Exheader, at offset 200h and up)

      200h 200h  SCI, System Control Info
      400h 200h  ACI, Access Control Info 1
      600h 100h  RSA-SHA256 Signature across [900h..BFFh] (using key from bootrom)
      700h 100h  RSA Public Key for NCCH Header at [000h..1FFh]
      800h 200h  ACI, Access Control Info 2 (for limitation of first ACI)

When loading the exheader, Process9 compares the exheader data with the data in the AccessDesc (note that not everything is compared here). When these don't match, an error is returned. The Process9 code handling this validation was updated with v6.0; the only change in this function seems to be the check for the "Ideal processor" field.
System Control Info (SCI)

      200h 8     Application title (default is "CtrApp") or module name (eg. "mcu")
      208h 5     Reserved
      20Dh 1     Flags (bit0=Compressed .code file, bit1=SD Application)
      20Eh 2     Remaster version
      210h 4     Text code set info Address (usually 00100000h)             ;\
      214h 4     Text code set info Size in 1000h-byte page units           ; Code
      218h 4     Text code set info Size in bytes (excluding padding)       ;/
      21Ch 4     Stack size (in bytes?) (usually 1000h)                     ;-Stack
      220h 4     Read-only code set Address (should be 1000h-page aligned)  ;\
      224h 4     Read-only code set Size in 1000h-byte page units           ; Const
      228h 4     Read-only code set Size in bytes (excluding padding)       ;/
      22Ch 4     Reserved
      230h 4     Data code set info Address (should be 1000h-page aligned)  ;\
      234h 4     Data code set info Size in 1000h-byte page units           ; Data
      238h 4     Data code set info Size in bytes (excluding padding)       ;/
      23Ch 4     BSS size (in bytes?) (usually XXXXh)                       ;-BSS
      240h 30h*8 Dependency module list (several 8-byte Title IDs)
      3C0h 8     SystemInfo SaveData Size
      3C8h 8     SystemInfo Jump ID
      3D0h 30h   SystemInfo Reserved

Most of these fields are used in LOADER:LoadProcess.
"On retail for SD applications, exheader_systeminfoflags.flag bit1 must be set."
Access Control Info (ACI)

     ARM11 Local System Capabilities:
      400h 8     Program ID (same as in NCCH Header)
      408h 4     Core version (Title ID low of required FIRM)
      40Ch 2     Flag1 and Flag2 (both implemented starting from 8.0.0-18).
      40Eh 1     Flag0
      40Fh 1     Priority
      410h 16*2  Resource limit descriptors ;1st byte controls max allowed CpuTime
      430h  8    Storage Info Extdata ID
      438h  8    Storage Info System savedata IDs
      440h  8    Storage Info Storage accessible unique IDs
      448h  8    Storage Info Filesystem Access Info (flags, see below)
      450h 32*8  Service Access Control
      550h 2*8   Extended service access control ;implemented with 9.3.0-X
      560h 15    Reserved
      56Fh 1     Resource limit category (0=APPLICATION, 1=SYS_APPLET,
                      2=LIB_APPLET,
                      3=OTHER (sysmodules running under the BASE memregion))
     ARM11 Kernel Capabilities:
      570h 70h   ARM11 Kernel Capability Descriptors (28x32bit)
      5E0h 10h   Reserved
     ARM9 Access Control:
      5F0h 15    ARM9 Access Control Descriptors
      5FFh 1     ARM9 Descriptor Version (must be 02h for original firmware,
                   must be 02h or 03h for 9.3.0-X and up)

Flag0

      Bits  Description
      0-1   Ideal processor
      2-3   Affinity mask
      4-7   Old3DS system mode:
              0    =  Prod (64MB of usable application memory)
              1    =  Undefined (unusable)
              2    =  Dev1 (96MB of usable application memory)
              3    =  Dev2 (80MB of usable application memory)
              4    =  Dev3 (72MB of usable application memory)
              5    =  Dev4 (32MB of usable application memory)
              6-7  =  Undefined Same as Prod?
              8-15 =  unknown/unspecified

In the exheader data, the ideal processor field is a bit-index, while in the AccessDesc (the 2nd ACI at A00h and up) the ideal processor field is a bitmask. When the bit specified by the exheader field is not set in the AccessDesc field, an error is returned.
if((1 << exheaderval) & accessdescval == 0) return error
During a FIRM-launch when a TitleInfo structure was specified, the field at offset 400h in the FIRM-launch parameters is set to the SystemMode of the specified title, however in some cases other values are written there. With 8.0.0-18 NS will now check the output of PTMSYSM command 040A0000h, when the output is non-zero and a certain NS state field is value-zero, the following is executed otherwise this is skipped. With that check passed on 8.0.0-18, NS will then check (Flag2 & 0Fh). When that is value2, the output value (used for the FIRM-launcher parameter field mentioned above) is set to value7. Otherwise, when that value is non-zero, the output value is set to 6.
Flag1

      Bits  Description
      0     EnableL2Cache (Unknown what this actually does, New3DS-only presumably)
      1     cpuspeed_804MHz (Default "cpuspeed" when not set)
      2-7   Unused

In order for the exheader to have any of the above new bits set, the AccessDesc must have the corresponding bit set, otherwise the invalid-exheader error is returned.
Homebrew which runs under a title which has the above cpuspeed flag set, runs much faster on New3DS. It's unknown how exactly the system handles these flags.
When launching titles / perhaps other things with APT, NS uses PTMSYSM:ConfigureNew3DSCPU with data which originally came from these flags; NS does this regardless of what the running 3DS system is. However, due to a bug(?) in NS the value sent to that command is always either 00h or 03h. When calculating that value, the code only ever uses the cpuspeed field, not the cache field: code to actually load and check the value of the cache field appears to be missing.
Flag2

      Bit     Description
      0-3     New3DS system mode:
                0    = Legacy (use Old3DS system mode)
                1    = Prod (124MB of usable application memory)
                2    = Dev1 (178MB of usable application memory)
                3    = Dev2 (124MB of usable application memory)
                4-7  = Undefined Same as Prod?
                8-15 = unknown/unspecified
      4-7     Unused

When in Legacy mode, the actual memory layout is the same as in New3DS Prod, except the available application memory as reported to the application is reduced to the Old3DS size.
The exheader value for the New3DS system mode value must be equal to the AccessDesc value, otherwise the invalid-exheader error is returned.
Storage Info Filesystem Access Info

      Bit    Description
      0      Category system application
      1      Category hardware check
      2      Category filesystem tool
      3      Debug
      4      TWL card backup
      5      TWL NAND data
      6      BOSS
      7      sdmc:/
      8      Core
      9      nand:/ro/ (Read Only)
      10     nand:/rw/
      11     nand:/ro/ (Write Access)
      12     Category system settings
      13     Cardboard
      14     Export/Import IVS
      15     sdmc:/ (Write-only)
      16     Switch cleanup (Introduced in 3.0.0?)
      17     Savedata move (Introduced in 5.0.0)
      18     Shop (Introduced in 5.0.0)
      19     Shell (Introduced in 5.0.0)
      20     Category home menu (Introduced in 6.0.0)
      21     Seed DB (Introduced in 9.6.0-X FIRM, Home Menu
                      has this bit set starting with 9.6.0-X)
      22-55  Reserved
      56     Not use RomFS
      57     Use Extended Savedata Access
      58-63  Reserved

When bit57 is set, the "Extdata ID" and "Storage Accessable Unique IDs" regions are used to store a total of 6 "Accessible Save IDs". Introduced in 6.0.0.
Service Access Control
This is the list of services which the process is allowed to access, this is registered with the services manager. Each service listed in the exheader must be listed in the AccessDesc, otherwise the invalid exheader error is returned. The order of the services for exheader/AccessDesc doesn't matter. The AccessDesc can list services which are not in the exheader, but normally the service-access-control data for exheader/AccessDesc are exactly the same.
This list is submitted to SRVPM:RegisterProcess.
ARM11 Kernel Capability Descriptors
The kernel capability descriptors are passed to svcCreateProcess.
There are different descriptor types, determined by the number of leading ones in the binary value representation of bits 20-31. The different types are laid out as follows:

      Bit31-20      Expl.
      1110xxxxxxxx  Interrupt info
      11110xxxxxxx  System call mask
                      Bits 24-26: System call mask table index
                      Bits 0-23: mask
      1111110xxxxx  Kernel release version
                      Bits 8-15: Major version
                      Bits 0-7: Minor version
      11111110xxxx  Handle table size
                      Bits 0-18: size
      111111110xxx  Kernel flags
                      Bit  Description
                      0    Allow debug
                      1    Force debug
                      2    Allow non-alphanum
                      3    Shared page writing
                      4    Privilege priority
                      5    Allow main() args
                      6    Shared device memory
                      7    Runnable on sleep
                      8-11 Memory type (1: application, 2: system, 3: base)
                      12   Special memory
                      13   Process has access to CPU core 2 (New3DS only)
      11111111100x  Map address range
                      Describes a memory mapping like the 111111111110
                      descriptor, but an entire range rather than a single
                      page is mapped. Another 11111111100x descriptor
                      must follow this one to denote the (exclusive) end
                      of the address range to map
      111111111110  Map memory page
                      Bits 0-19: page index to map (virtual address >> 12;
                      the physical address is determined per-page according
                      to Memory layout); Bit 20: Map read-only (otherwise
                      read-write)

ARM9 Access Control Descriptors

      Bit     Description
      0       Mount nand:/
      1       Mount nand:/ro/ (Write Access)
      2       Mount twln:/
      3       Mount wnand:/
      4       Mount card SPI
      5       Use SDIF3
      6       Create seed
      7       Use card SPI
      8       SD application (Not checked)
      9       Mount sdmc:/ (Write Access)

3DS NCCH ExeFS

ExeFS Header (max 10 files)

      000h 10h*10  File headers for File 1..10        ;First at 000h
      0A0h 20h     Reserved
      0C0h 20h*10  SHA256 Hash for File 10..1         ;First at 1E0h

File hashes are stored in reverse order, i.e. the hash at offset 1E0h corresponds to the first ExeFS section.
Each file header has a corresponding file hash, which is the SHA256 hash calculated over the entire file contents.
File headers
There are a maximum of 10 file headers in the ExeFS format (the maximum number of file headers is disputable, with makerom indicating a maximum of 8 sections and makecia indicating a maximum of 10 (uh, are homebrew tools?). From a non-SDK point of view, the ExeFS header format can hold no more than 10 file headers within the currently define size of 200h bytes). The file headers have the following structure:

      00h 8     File name (ASCII, zeropadded) (all 00h for unused entries)
      08h 4     File offset in bytes (0=Right after the 200h-byte ExeFS Header)
      0Ch 4     File size in bytes

File offsets are non-inclusive of the header's size (200h bytes). Also, file headers which are not used are filled with all zeros.
The file offsets should be 200h-byte aligned. The file size is usually 4-byte aligned (unknown if that is actually required).
ExeFS Files
ExeFS or Executable Filesystem contains information related to the executable program, and is the part of the CXI format.
The ExeFS usually contains one or more of the following files:

      .code   Contains ARM11 code, which can be optionally
                reverse-LZSS compressed via an exheader flag.
      .firm   unknown/unspecified (supposedly FIRM with ARM9/ARM11 code)
      logo    Contains distribution licensing Binary data
      banner  Contains the banner which homemenu uses for this CXI
      icon    Contains the icon which homemenu displays for this CXI

3DS NCCH Logo
.code (ARM11)
The .code file does simply contain plain code/data without any file header (instead, the .code file's load addresses and compression flag are located in the NCCH Exheader).
For the LZrev decompression function, see:
LZ Decompression Functions
The (decompressed) filesize should be a multiple of 1000h bytes (and the code/const/data sections should be on 1000h-byte page boundaries, as specified in the NCCH Exheader).
.code (GBA)
The .code files for GBA games do reportedly contain the GBA ROM-image, with an extra GBA Footer (with info on cartridge type and preferred LCD color scheme). For details:
3DS Config - ARM7 Registers (GBA/NDS/DSi Mode)
Unknown if GBA games have specific entries in NCCH header/exheader.

3DS NCCH RomFS

Overall RomFS file structure

      00000h 5Ch     RomFS Header (see below)                          ;Header
      0005Ch 4       Padding to 20h-byte boundary (0)
      00060h 20h*N   SHA256's on the 1000h-byte block(s) at xx000h     ;Master Hash
      ...    ..      Padding to block-byte boundary (0)
      01000h ....    RomFS Directory/Files (see below)                 ;Level 3
      ...    ..      Padding to block-byte boundary (0)
      xx000h 20h*NN  SHA256's on each 1000h-byte block at yy000h and up;Level 1
      ...    ..      Padding to block-byte boundary (0)
      yy000h 20h*NNN SHA256's on each 1000h-byte block at 1000h and up ;Level 2

RomFS Header (5Ch bytes)

      000h 8   ID "IVFC",00h,00h,01h,00h
      008h 4   Master Hash Size (eg. 20h) (aka Size of SHA256's at 00060h)
      00Ch 8   Level 1 Logical Offset             (usually 0)                    ;\
      014h 8   Level 1 Size of SHA256's at xx000h (eg. 60h aka 24A0h/1000h*20h)  ;
      01Ch 4   Level 1 Block size (1 SHL N)       (usually 0Ch=1000h)            ;/
      020h 4   Reserved (0)
      024h 8   Level 2 Logical Offset             (eg. 1000h) (Level 1 size)     ;\
      02Ch 8   Level 2 Size of SHA256's at yy000h (eg. 24A0h aka 124A20h/1000h*20h)
      034h 4   Level 2 Block size (1 SHL N)       (usually 0Ch=1000h)            ;/
      038h 4   Reserved (0)
      03Ch 8   Level 3 Logical Offset             (eg. 4000h) (Level 1+2 size)   ;\
      044h 8   Level 3 Size of Directory/File area at 001000h  (eg. 124A20h)     ;
      04Ch 4   Level 3 Block size (1 SHL N)       (usually 0Ch=1000h)            ;/
      050h 4   Reserved (0)
      054h 4   Header Size or so?                 (usually 5Ch)
      058h 4   Optional info size (uh?)           (usually 0)
      05Ch 4   unknown/padding                    (usually 0)

The "Logical Offsets" are completely unrelated to the physical offsets in the RomFS partition. Instead, the "Logical Offsets" might be something about where to map the Level 1-3 sections in virtual memory (with the physical Level 3,1,2 ordering being re-ordered to Level 1,2,3)?
The various SHA256's are similar to the "Digest" tables in DSi cart header.
RomFS Directory/File area (aka Level 3) (usually/always? starting at 1000h)

      000h 4    Header Length (usually 28h)
      004h 4    Directory Hash Table Offset (usually 28h)
      008h 4    Directory Hash Table Length
      00Ch 4    Directory Table Offset (eg. 44h) (first=Root)
      010h 4    Directory Table Length
      014h 4    File Hash Table Offset
      018h 4    File Hash Table Length
      01Ch 4    File Table Offset (eg. 170h) (starting with Root)
      020h 4    File Table Length (eg. 52Ch)
      024h 4    File Data Offset (eg. 6A0h)
      028h ..   Directory Hash Table
      ..   ..   Directory Table
      ..   ..   File Hash Table
      ..   ..   File Table
      ..   ..   File Data (each file aligned to 10h-byte boundary)

Note: The first Directory Table entry is the Root directory. Apart from that, there is no real requirement for the location of the other directory (and file) table entries. However, Table entries are commonly held to be sorted alphabetically. And, Siblings should be stored at continous table offsets (so all entries for one directory are grouped together; that can speed up sector loading).
Directory Table Entries

      00h   4   Directory Table Offset of Parent Directory       (Self for Root)
      04h   4   Directory Table Offset of next Sibling Directory (FFFFFFFFh=None)
      08h   4   Directory Table Offset of first Child Directory  (FFFFFFFFh=None)
      0Ch   4   File Table Offset of first File                  (FFFFFFFFh=None)
      10h   4   Directory Table Offset of next Directory with same Hash
      14h   4   Name Length in bytes (ie. L=NumChars*2) (0 for Root)
      18h   L   Directory Name (16bit Unicode)
      18h+L 0/2 Alignment padding

File Table Entries

      00h   4   Directory Table Offset of Parent Directory
      04h   4   File Table Offset of next Sibling File           (FFFFFFFFh=None)
      08h   8   File Data Offset (64bit)
      10h   8   File Data Size   (64bit)
      18h   4   File Table Offset of next File with same Hash    (FFFFFFFFh=None)
      1Ch   4   Name Length in bytes (ie. L=NumChars*2)
      20h   L   File Name (16bit Unicode)
      20h+L 0/2 Alignment padding

File/Directory Hash Tables (for quick lookup)

      00h   N*4 Offset to File/Directory with matching Chksum (FFFFFFFFh=None)

These tables can be used for fast lookup (faster than doing char-by-char string compares for all names in directory). For searching a specific name in a specific directory, compute a checksum on the Directory Offset and Name:

      chksum = ParentDirectoryOffset XOR 123456789
      for i=0 to NameLength/2-1
        chksum = (chksum ROR 5) XOR Name[i*2]  ;32bit rotate, then XOR lower 16bit
      offset = hashtable [(chksum MOD (hashtablesize/4))*4]

Then verify if Name(offset) and ParentDirectory entry(offset) do actually match, and else retry with offset=NextHashOffset(offset).
Note: The hashtablesize's should be roughly same or bigger than the total number of files/directories in the RomFS (multiplied by 4, as each entry is 32bit wide). Even then, there can be false matches, including matches in different directories (which can slowdown things when needing additional sector reads for obtaining the table entries for such directories).
RomFS can be used for...

      in conjunction with the ExeFS of a NCCH
      to contain the game manual accessible from the Home Menu
      to contain the DLP Child CIA   ;uh, is that "CIA" a homebrew fileformat?
      to contain game cartridge update data

3DS NCCH Encryption

The extended header, the ExeFS, and the RomFS are encrypted using AES-CTR.
AES-CTR Encryption FirstKeyX and FirstKeyY:
The FirstKey is used for NCCH Exheader, and ExeFS Header, and for two ExeFS files ("icon" and "banner").

      FirstKeyX = KeyX from keyslot 2Ch (as set by bootrom)
      FirstKeyY = NCCH[000h..00Fh]  ;first 10h bytes of RSA signature

AES-CTR Encryption SecondKeyX and SecondKeyY:
The SecondKey is also used for the whole RomFS (header, all files, and SHA256's). And, for all ExeFS files (EXCEPT "icon" and "banner"), ie. it's used for ".code", ".firm", "logo", and any further ExeFS files.

      if NCCH[18Bh]=00h then SecondKeyX = KeyX from keyslot 2Ch (original firmware)
      if NCCH[18Bh]=01h then SecondKeyX = KeyX from keyslot 25h (firm7.0.0)
      if NCCH[18Bh]=0Ah then SecondKeyX = KeyX from keyslot 18h (firm9.3.0) ;\New
      if NCCH[18Bh]=0Bh then SecondKeyX = KeyX from keyslot 1Bh (firm9.6.0) ;/3DS
      if NCCH[18Fh].bit5=0 then SecondKeyY = NCCH[000h..00Fh]   (original firmware)
      if NCCH[18Fh].bit5=0 then SecondKeyY = see SEEDDB below   (firm9.6.0)

With the original firmware, the SecondKey is just same as FirstKey (ie. there's only one key in that case). Newer firmwares have added the extra keys shown above, but they aren't used for ALL titles (eg. a new 3DS may use
keyslot 25h for eShop, and keyslot 2Ch for System Settings).
SecondKeyY from SEEDDB (firm9.6.0) (New3DS)

      ;load SEEDDB (nand:/data/<ID0>/sysdata/0001000f/00000000),
      ;that file contains 32byte entries (with 8-byte Title ID, 16-byte seed,
      ;plus 8-byte reserved; whereof titleid might refer to ProgramID or so?),
      ;find the matching entry for current "titleid", then do:
      temp[00h..0Fh] = seed for current title (from SEEDDB file)           ;\
      temp[10h..17h] = NCCH[118h..11Fh]  ;Program ID                       ; test
      sha256(dst=temp, src=temp, srclen=18h)                               ;
      if temp[00h..03h] <> NCCH[114h..117h] then error                     ;/
      temp[00h..0Fh] = NCCH[000h..00Fh]  ;first 10h bytes of RSA signature ;\
      temp[10h..1Fh] = seed for current title (from SEEDDB file)           ; key
      sha256(dst=temp, src=temp, srclen=20h)                               ;
      SecondKeyY=temp[00h..0Fh]  ;use first 10h bytes of SHA256 as KeyY    ;/

Special Cases

      if NCCH[18Fh].bit2=1                     ;\NoCrypto flag (eg. in NCCH's
        Exit  ;not encrypted                   ;/located inside of FIRM files)
      if NCCH[118h..11Fh]=NCCH[400h..407h]     ;\
        SkipDecrypt (or NeedEncrypt)           ; Program ID in Header vs Exheader
        ;above can be checked only if Exheader ; currently/already decrypted
        ;does exist, ie. if NCCH[180h]<>0      ;/
      if NCCH[18Fh].bit0=1  ;FixedCryptoKey flag         ;\
        if (ProgramID.MSW AND FFFFC010h)=00040010h       ; debug only, not retail:
          NormalKey=FixedSystemKey (52h,7Ch,E6h,30h,..)  ; instead of First/Second
        else                                             ; KeyX+KeyY
          NormalKey=Zerofilled (00h's)                   ;/

Encryption IV

      if NCCH[112h]=01h  ;NCCH version (weird, is/was that version really used?)
        Force MediaUnitSize=1 (or 200h?) ;fixed? (instead of 200h SHL N bytes?)
        IV[00h..07h] = NCCH[108h..10Fh]    ;NCCH Partition ID (forwards!)
        IV[08h..0Bh] = Zero
        IV[0Ch..0Fh] = BigEndianAddr (200h=Exheader, [1A0h]=ExeFS, [1B0h]=RomFS)
      if NCCH[112h]=02h  (or =00h, too?)   ;NCCH version
        IV[00h..07h] = NCCH[10Fh..108h]    ;NCCH Partition ID (backwards!)
        IV[08h]      = Type (01h=Exheader, 2=ExeFS, 3=RomFS)
        IV[09h..0Fh] = Zero (plus offset/10h within Exheader/ExeFS/RomFS area)

When starting elsewhere than BEGIN of Exheader/ExeFS/RomFS, add offset/10h to the IV value (whereas, mind that IV is big-endian in the above description; it may be easier to set the IV in little-endian mode though).

3DS NCCH Logo

The logo was originally stored as file "logo" (in the encrypted ExeFS). Newer files have the logo stored in separate unencrypted data block (see NCCH header entries [130h,198h,19Ch]). Even in newer firmwares, the old location in "logo" file is still used by Safe Mode files (at least so on Old3DS). Unknown if the new logo block can also exist in absence of ExeFS.
"The Logo contains distribution licensing Binary data (types: Nintendo, Licensed, Published, or Distributed). Additionally it could have no license (type None). System applications and applets that interact with the Home Menu are typically set to type 'none' as they don't display that information."
Logo Compression
Reportedly "contains distribution licensing Binary data".
"The size of this logo is always 2000h-bytes."
The logo seems to be LZ11 compressed, see:
LZ Decompression Functions
This file is a LZ11 compressed DARC. The last 20h bytes of the decompressed data is a HMAC SHA256 hash over the actual DARC.
The HMAC key(s) used for the SHA256-HMAC is unknown.
Logo DARC Archive
3DS Files - Archive DARC
The DARC contains three folders and several files (below is from Safe Mode System Updater):

      anim
        NintendoLogo_D_00_SceneOutA.bclan  ;\
        NintendoLogo_D_00_SceneOutB.bclan  ; D
        NintendoLogo_D_00_SceneOutC.bclan  ;/
        NintendoLogo_U_00_SceneOutA.bclan  ;\
        NintendoLogo_U_00_SceneOutB.bclan  ; U
        NintendoLogo_U_00_SceneOutC.bclan  ;/
      blyt
        NintendoLogo_D_00.bclyt            ;-D
        NintendoLogo_U_00.bclyt            ;-U
      timg
        3dsLogo_00.bclim
        3dsLogo_01.bclim
        3dsLogo_02.bclim
        3dsLogo_03.bclim
        LT_00.bclim
        LT_01.bclim
        LTMask_00.bclim
        Nintendo_128x64.bclim

Unknown if other logo/darc packages contain other file/folder names.
Logo DARC Files
3DS Files - Video Layout (CLYT/FLYT)
3DS Files - Video Layout Animation (CLAN/FLAN)
3DS Files - Video Layout Images (CLIM/FLIM)

3DS Files - Title Content Metadata (CMD)

Content Metadata (.cmd) file format

      00h     4    File number for 000000nn.cmd file (eg. 3=00000003.cmd)
      04h     4    Number of Contents (N)
      08h     4    Number of Contents (N) (same as above)
      0Ch     4h   Zerofilled  ;reportedly always 1  ;\maybe shop titles??
      10h     10h  Zerofilled  ;reportedly AES-MAC   ;/or SD card exports???
      20h     N*4  List of file numbers for 000000nn.app files
      20h+N*4 N*4  List of file numbers for 000000nn.app files (same as above)
      20h+N*8 -    Nothing     ;reportedly more AES-MAC's ???

The .cmd file is reportedly "encrypted with a console unique keyslot"??? (actually, it isn't encrypted at all, at least not on eMMC).
"<ContentID>.cmd" - (The Content ID is a u32, initially: 00000001 when the title is first installed. Changing by an increment of +0x1 for each time the 3DS adds/removes '.app' files) This file contains data taken from the title's TMD. See the below table for the format of the cleartext .cmd file. The Title.db contains the Content ID for the '.cmd' file, but does not contain a hash of the '.cmd' file. This acts as part of the DRM for installed titles, along with the title.db.
The below AES-CMACs (including the last 0x10-bytes of the header) are only used for SD titles, for NAND download-play titles, and non-system DSiWare titles. For other titles, these MACs are set to all-zero.

      000h 4      .cmd ContentID, for the .cmd filename. This is the beginning
                    of the header   ;uh, which header? what for?
      004h 4      Number of AES-CMACs and Content IDs in the first list (X).
                    The method to determine this is explained below.
      008h 4      Number of Content IDs in the second list (Y)
      00Ch 4      Unknown, usually (always?) 1.
      010h 10h    AES-CMAC over first 0x10
      020h 4*X    List of installed Content IDs in order of Content Index, with
                    missing contents replaced with 0xFFFFFFFF
      020h+4*X     4*Y     List of installed Content IDs in order of ID name
      020h+4*(X+Y) 10h*X   AES-CMACs for each content in the first list, generated
                             using the process below

The number of AES-CMACs depends on the highest Content Index installed. For example, a title with 5 contents, but only 1 and 3 are installed, will still result in 3 AES-CMACs, with the 2nd one being unused.
For SD contents, each AES-CMAC is generated by combining the NCCH header without the signature (0x100-0x1FF), the Content Index and Content ID at the end, both as u32. Then calculate the SHA256 of the data and generate the AES-CMAC using the SD/NAND AES-CMAC key.
For TWLNAND contents, the same process is used (even for SRL contents) with the keyslot for NAND dbs.

3DS Files - Title Metadata (TMD)

Title metadata is a format used to store information about a title (installed title, DLC, etc.) and all its installed contents, including which contents they consist of and their SHA256 hashes.
Signature Type

      Value           Signature Method        Signature Size  Padding Size
      0x010000        RSA_4096 SHA1 (Unused for 3DS)            0x200   0x3C
      0x010001        RSA_2048 SHA1 (Unused for 3DS)            0x100   0x3C
      0x010002        Elliptic Curve with SHA1 (Unused for 3DS) 0x3C    0x40
      0x010003        RSA_4096 SHA256                           0x200   0x3C
      0x010004        RSA_2048 SHA256                           0x100   0x3C
      0x010005        ECDSA with SHA256                         0x3C    0x40

The hash for the signature, is calculated over the header of the TMD.
TMD Format

      000h 4      Signature Type (00h,01h,00h,04h) (100h-byte RSA-SHA256)
      004h 100h   Signature RSA-SHA256 across 140h..203h
      104h 3Ch    Signature padding/alignment (zerofilled)
      140h 40h    Signature Name "Root-CA00000003-CP0000000b", 00h-padded
      180h 1      TMD Version (always 1 on 3DS, unlike DSi)
      181h 1      ca_crl_version (0)
      182h 1      signer_crl_version (0)
      183h 1      Zero       (padding/align 4h)
      184h 8      System Version (0)
      18Ch 8      Title ID
      194h 4      Title Type     (40h, big-endian)
      198h 2      Group ID       (0)
      19Ah 4      SD/MMC "public.sav" filesize in bytes  (3DS: savedata size)
      19Eh 4      SD/MMC "private.sav" filesize in bytes (3DS: 0=none)
      1A2h 4      Zero
      1A6h 1      SRL Flag (00h=3DS, but also 0=DSiware, uh?)
      1A7h 3      Zero
      1AAh 10h    Zerofilled (DSi: Parental Control Age Ratings)
      1BAh 1Eh    Zerofilled
      1D8h 4      Access Rights (0)
      1DCh 2      Title Version
      1DEh 2      Content Count (number of entries at B04h)
      1E0h 2      Boot Content
      1E2h 2      Padding
      1E4h 20h    SHA256 across Content Info Records at [204h..B03h]
      204h 900h   Content Info Records (40h entries, with 24h-bytes each)
      B04h 30h*N  Content Chunk Records (N entries, with 30h-bytes each)

Content Info Records (useless, can be ignored, except for error checking)
There are 64 of these records, usually only the first is used.

      000h 2    Content index offset  (I)
      002h 2    Content command count (N)
      004h 20h  SHA256 across TMD[B04h+I*30h+(0..N*30h-1)    ;(?)

Content chunk records
There is one of these for each content contained in this title (determined by "Content Count" in the TMD Header).

      000h 4    Content id    (aka name of .app file maybe?) (homebrew/dev=random?)
      004h 2    Content index (see below)
      006h 2    Content type  (see below)
      008h 8    Content size  (of app file)
      010h 20h  SHA-256 hash  (on what? the app file?) (before/after decrypt?)

Content Index:

      0000h = Main Content (3DS NCCH.exec, or 3DS NCCH.data, or DSiware/DSidata)
      0001h = Home Menu Manual (.CFA)
      0002h = DLP Child Container (.CFA)
      This does not apply to DLC.

Content Type flags:

      0     Encrypted (CIA blocks)  (0=Unencrypted/homebrew, 1=Encrypted)
      1     Disc (uh?)              (0=Normal, 1=whut?)
      2     CFM (abbreviation for?) (0=Normal, 1=whut?)
      3-13  Zero                    (0=Normal)
      14    Optional (uh?)          (0=Normal, 1=whut?)
      15    Shared (uh?)            (0=Normal, 1=whut?)

Certificate Chain
If the TMD file is obtained from Nintendo's CDN, then it will have two certificates appended at the end of the file:

      CERTIFICATE  SIG.TYPE  RETAIL CERT  DEBUG CERT  DESCRIPTION
      TMD          RSA-2048  CP0000000b   CP0000000a  to verify the TMD signature
      CA           RSA-4096  CA00000003   CA00000004  to verify the TMD Certificate

The CA certificate is issued by 'Root', the public key for which is stored in NATIVE_FIRM.

3DS Files - Title Ticket (ticket.db)

3ds:\dbs\ticket.db (about 35.5Mbytes) (237F600h bytes)
ticket.db is a DIFF container containing a short 10h-byte header followed by a BDRI filesystem.
3DS Files - Savedata DISA and DIFF
3DS Files - Savedata SAVE/BDRI/VSXE Formats
The 10h-byte header (between DIFF and BDRI layer) looks as so:

      000h 8    ID "TICK",01h,00h,00h,00h
      008h 4    Garbage (eg. random, or 0)
      00Ch 4    Garbage (eg. random-30h, or 1)
      010h ...  BDRI filesystem (about 17Mbytes) (10A2000h) (with ticket files)

The BDRI can contain up to 8192 files, usually it does contain about 200 tickets for the system titles, including the DSiware titles, plus any further tickets for titles purchased from e-Shop (no matter if the titles are stored on eMCC or on SD Cards).
Tickets are a format used to store an encrypted titlekey (using AES-CBC). With 3DS, the Ticket format was updated (now v1) from Wii/DSi format (v0).
DSi SD/MMC DSiware Tickets and Title metadata
Ticket format

      Pre   4    One (1) (unknown purpose)   ;\little endian  ;\in ticket.db
      Pre   4    Size of below ticket (350h) ;/               ;/(not in .cia's)
      000h  4    Signature Type (00h,01h,00h,04h) (100h-byte RSA-SHA256)
      004h  100h Signature RSA-SHA256 across 140h..34Fh ?
      104h  3Ch  Signature padding/alignment (zerofilled)
      140h  40h  Signature Name "Root-CA00000003-XS0000000c", 00h-padded
      180h  3Ch  ECC Public Key (uh, what for?) (can be zero/none)
      1BCh  1    Ticket Version (always 1 on 3DS) (unlike DSi/Wii)
      1BDh  1    CaCrl Version
      1BEh  1    SignerCrl Version
      1BFh  10h  TitleKey (normal-key encrypted using one of the common keyYs)
      1CFh  1    Zero
      1D0h  8    Ticket ID  (00,04,xx,xx,xx,xx,xx,xx) ?   (...or random 64bit)
      1D8h  4    Console ID (Decrypted OTP[04h..07h], in reverse byte-order)
      1DCh  8    Title ID   (00,04,xx,xx,xx,xx,xx,xx) (same as ticket filename)
      1E4h  2    Zero
      1E6h  2    Title Version
      1E8h  4    Zero
      1ECh  4    Zero
      1F0h  1    License Type
      1F1h  1    Common keyY number for [1BFh] (0..5) (1 for retail system titles)
      1F2h  2Ah  Zero
      21Ch  4    eShop Account ID? (zero in many system files)
      220h  1    Zero
      221h  1    Audit (whatever, usually 01h)   (can be 00h, for debug/whatever?)
      222h  20h  00h-filled (Wii: Content access permissions, 1 bit per content)
      242h  20h  00h-filled (Wii: Content access permissions, 1 bit per content)
      262h  2    Zero
      264h  40h  Limits
      2A4h  ACh  Content Index (*)  (uh, but WHAT is a Content Index ??)
      350h  ..   Certificates (included in e-Shop downloads, not stored in files)

* The Content Index of a ticket has its own size defined within itself (usually ACh), with seemingly a minimal of 20 bytes.
The "Content Index" (whatever that is) at 2A4h looks as so:

      2A4h  4    Unknown (00h,01h,00h,14h)
      2A8h  4    Unknown (00h,00h,00h,ACh) Size of stuff at 2A4h..34Fh ?
      2ACh  4    Unknown (00h,00h,00h,14h)
      2B0h  4    Unknown (00h,01h,00h,14h)
      2B4h  4    Unknown (00h,00h,00h,00h)
      2B8h  4    Unknown (00h,00h,00h,28h)
      2BCh  4    Unknown (00h,00h,00h,01h)
      2C0h  4    Unknown (00h,00h,00h,84h)
      2C4h  4    Unknown (00h,00h,00h,84h)
      2C8h  4    Unknown (00h,03h,00h,00h)
      2CCh  4    Unknown (00h,00h,00h,00h)
      2D0h  20h  Unknown (FFh-filled) (or 00h-filled in some tickets)
      2F0h  60h  Unknown (00h-filled)

Signature Type

      Value       Signature Method                  Signature Size  Padding Size
      0x010000    RSA_4096 SHA1 (Unused for 3DS)            0x200   0x3C
      0x010001    RSA_2048 SHA1 (Unused for 3DS)            0x100   0x3C
      0x010002    Elliptic Curve with SHA1 (Unused for 3DS) 0x3C    0x40
      0x010003    RSA_4096 SHA256                           0x200   0x3C
      0x010004    RSA_2048 SHA256                           0x100   0x3C
      0x010005    ECDSA with SHA256                         0x3C    0x40

The hash for the signature is calculated over the Ticket Data.
The Ticket Title Version is generally the same as the title version stored in the Title Metadata. Although it doesn't have to match the TMD version to be valid.
TitleKey (for decrypting .app's in CIA's or Shop downloads)
First of, decrypt the ticket's Title Key via AES-CBC:

      dev/retail      = can be detected from RSA Signature Name at TIK[140h]
      KEY_X[00h..0Fh] = Keyslot 3Dh, as set by bootrom (differs for retail/dev)
      KEY_Y[00h..0Fh] = common key(0..5) from FIRM, index 0..5 from TIK[1F1h]
      KEY[00h..0Fh]   = derived from above KeyX/Y (retail key0..5 and dev key1..5)
      KEY[00h..0Fh]   = fixed normal key from FIRM (special, for dev key0 only)
      IV[00h..07h]    = Title ID (big-endian), from TIK[1DCh]
      IV[08h..0Fh]    = Zero
      SRC[00h..0Fh]   = Encrypted Title Key, from TIK[1BFh]
      aes-cbc decrypt

Then use the decrypted key to decrypt the .app via AES-CBC:

      KEY[00h..0Fh]   = Decrypted title key (decrypted from ticket)
      IV[00h..01h]    = Content Index (big endian, from TMD[B04h+N*30h+4])
      IV[02h..0Fh]    = Zero
      SIZE            = Content Size (from TMD[B04h+N*30h+8])
      aes-cbc decrypt (unless TMD[B04h+N*30h+6] has flagged encryption=0)

Note: For AES-CBC random access, one can use the preceeding "encrypted 10h-byte block" as IV value (except, use the above IV for first block).
Unknown if there is a dev/retail flag in the ticket (if not, then one could
instead check the RSA Signature Name; retail="Root-CA00000003-XS0000000c")
Limits
In demos, the first u32 in the "Limits" section is 0x4, then the second u32 is the max-playcount.
Certificate Chain
Tickets retrieved from CDN/SOAP have a certificate chain appended at the end of the file. There are two certificates in this chain:

      CERTIFICATE SIG.TYPE  RETAIL CERT  DEBUG CERT  DESCRIPTION
      Ticket      RSA-2048  XS0000000c   XS00000009  to verify Ticket signature
      CA          RSA-4096  CA00000003   CA00000004  to verify Ticket Certificate

The CA certificate is issued by 'Root', the public key for which is stored in NATIVE_FIRM.
Notes
CommonETicket (for short, cetk) is the name given to tickets for titles which are not available on the eShop, like system titles. As the name suggests, they are not unique tickets, the same ticket is common to each 3ds which has installed that title. This is in contrast to tickets for eShop content, which are generated prior to initial download, and are unique to 3ds it was generated for.
CETK can be fetched through HTTP using the link to default update server, using the title's TMD URL where "cetk" is used instead of "tmd" for the URL. The 3DS NIM module retrieves system tickets via SOAP request GetSystemCommonETicket instead of directly downloading the cetks with HTTPS. The cetks are also accessible via HTTP (even though the 3DS never accesses them like that).
Other Ticket files/folders
Apart from ticket.db, there is a 4B000h-byte file called 3ds:\tmp\title.tik containing the following stuff:

      0000h 350h    Ticket (without 8-byte header)    ;-350h-byte ticket
      0350h 9Ch     Unknown (00h-filled)              ;\                    ;\
      03ECh 4       Unknown (FFh,FFh,E3h,E7h)         ; 128h-byte whatever  ; fifty
      03F0h 88h     Unknown (00h-filled)              ;/                    ; 128h
      0478h 9Ch     Unknown (00h-filled)              ;\                    ; byte
      0514h 4       Unknown (FFh,FFh,E3h,E7h)         ; 128h-byte as above  ; blks
      0518h 88h     Unknown (00h-filled)              ;/                    ;
      ...   48*128h ...                               ;-128h-byte's as above;/
      3D20h 0B8h    Unknown (00h-filled)              ;\
      3DD8h 4       Unknown (52h,46h,00h,00h)         ; whatever
      3DDCh 4       Unknown (58h,A8h,07h,00h)         ;
      3DE0h 4       Unknown (B4h,32h,15h,00h)         ;/
      3DE4h 4721Ch  Unknown (00h-filled)              ;-lots of zeroes

Additionally, there are two empty ticket folders:

      3ds:\ticket\     ;on 3DS partition
      dsi:\ticket\     ;on DSi partition

The latter would have been used on DSi to store .tik files (but the 3DS does instead store all tickets in ticket.db, including DSiware tickets).

3DS Files - Title Certificates (certs.db)

3ds:\dbs\certs.db (6000h-byte DIFF container with 2800h bytes of raw data)

      000h 4     ID "CERT"                                           ;\
      004h 4     Zero                                                ; header
      008h 4     Size of used area at 010h..A0Fh ? (A00h)            ;
      00Ch 4     Random garbage? (eg. 080FFFE0h or 080496E1h)        ;/
      010h 4     Signature Type (00,01,00,03) (200h-byte RSA-SHA256) ;\
      014h 200h  Signature RSA across 250h..40Fh ?                   ;
      214h 3Ch   Signature padding/alignment (zerofilled)            ;
      250h ..    Signature Name ("Root", zeropadded)                 ;
      290h ..    Key Type (00,00,00,01) (100h-byte RSA)              ; CA00000003
      294h ..    Key Name ("CA00000003", zeropadded)                 ; (for below)
      2D4h 4     Key Random/time/type/flags/chksum?    7BE8EF6Ch     ;
      2D8h 100h  Key Public RSA Key (B2,79,C9,E2,...)                ;
      3D8h 4     Key Public RSA Exponent? (00,01,00,01)              ;
      3DCh 34h   Key padding/alignment (zerofilled)                  ;/
      410h 4     Signature Type (00,01,00,04) (100h-byte RSA-SHA256) ;\
      414h 100h  Signature RSA across 550h..70Fh ?                   ;
      514h 3Ch   Signature padding/alignment (zerofilled)            ;
      550h ..    Signature Name ("Root-CA00000003", zeropadded)      ;
      590h ..    Key Type (00,00,00,01) (100h-byte RSA)              ; CP0000000b
      594h ..    Key Name ("CP0000000b", zeropadded)                 ; (for TMDs)
      5D4h 4     Key Random/time/type/flags/chksum?    137A080Bh     ;
      5D8h 100h  Key Public RSA Key (A6,89,C5,90,...)                ;
      6D8h 4     Key Public RSA Exponent? (00,01,00,01)              ;
      6DCh 34h   Key padding/alignment (zerofilled)                  ;/
      710h 4     Signature Type (00,01,00,04) (100h-byte RSA-SHA256) ;\
      714h 100h  Signature RSA across 850h..A0Fh ?                   ;
      814h 3Ch   Signature padding/alignment (zerofilled)            ;
      850h ..    Signature Name ("Root-CA00000003", zeropadded)      ;
      890h ..    Key Type (00,00,00,01) (100h-byte RSA)              ; XS0000000c
      894h ..    Key Name ("XS0000000c", zeropadded)                 ; (for
      8D4h 4     Key Random/time/type/flags/chksum?    137A0894h     ; Tickets)
      8D8h 100h  Key Public RSA Key (AD,50,5B,B6,...)                ;
      9D8h 4     Key Public RSA Exponent? (00,01,00,01)              ;
      9DCh 34h   Key padding/alignment (zerofilled)                  ;/
      A10h 1F0h  Padding (0)                                         ;\unused
      C00h 1C00h Random garbage?                                     ;/

The 200h-byte Public Key for the 'Root' signature is reportedly somewhere in NATIVE_FIRM (unknown where though, knowing the first some bytes would help) (also unknown if it is the same 'Root' key as on DSi).
The DSi has a similar file called cert.sys:
DSi SD/MMC Firmware dev.kp and cert.sys Certificate Files
The DIFF container uses the standard DISA/DIFF format
3DS Files - Savedata DISA and DIFF
However, the DIFF in certs.db does contain raw data (instead of the SAVE/BDRI/VSXE filesystems that are usually found in DISA/DIFF containers).

3DS Files - Title Database Files (title.db, import.db, etc.)

These files contain data relating to install/usage/management of installed 3DS titles. The database files are located at:

      3ds:\dbs\*.db
      sd:\Nintendo 3DS\<ID0>\<ID1>\dbs\*.db

ID0 is the first 0x10-bytes from a SHA256 hash. The installation of SD Card titles was introduced in the 2.0.0-2 update and the SD dbs files are encrypted by the general SD filesystem encryption rule. These files are DIFF containers. These DIFF files do not use external IVFC level 4, so all database data is duplicated in the container. In this page only the inner content of the container is described.
These files are only created on SD (via AM) if they don't exist when the eShop application is starting up, during network init etc (prior to showing the "system update required" dialog).
3ds:\dbs\title.db (can contain max 1379 files)
sd:\Nintendo 3DS\<ID0>\<ID1>\dbs\title.db
Title database, contains entries for all installed titles (TWL & CTR) on the 3DS (each database is responsible for titles installed on its medium).
3ds:\dbs\import.db
sd:\Nintendo 3DS\<ID0>\<ID1>\dbs\import.db
Import Databases, containing entries for titles (or versions of titles) not yet installed, ready for transferring to the title.db. ("Automatic Update uses this, so completing the update takes seconds." uh, why does that take so much time?)
3ds:\dbs\tmp_t.db
Temporary Title database containing one entry for the currently installed Download Play Child.
3ds:\dbs\tmp_i.db
Similar to import.db, except it's used in conjunction with tmp_t.db, for installing Download Play Children.
The inner content of the container consists of a pre-header with size of 0x80 identifying the Database Type, followed by a BDRI container. The offsets in the BDRI header are usually relative to the offset to the start of the BDRI header (0x80 in the file)
Pre Header

      000h 8    ID (eg. "NANDTDB",00h) (see below)
      008h 78h  Reserved
      080h ...  BDRI filesystem (with 80h-byte files containing Title Info)

The 8-byte ID can be:

      ID="NANDIDB",00h --> 3ds:\dbs\import.db
      ID="NANDTDB",00h --> 3ds:\dbs\title.db
      ID="TEMPIDB",00h --> 3ds:\dbs\tmp_i.db, tmp_t.db
      ID="TEMPTDB",00h --> sd:\Nintendo 3DS\<ID0>\<ID1>\dbs\import.db, title.db

Title Info Entry -- is that... maybe "title.db" files...?
An entry contains information taken from both the application NCCH file(s) and TMD.

      000h 8    Title Size
      008h 4    Title Type (usually 40h)
      00Ch 4    Title Version
      010h 1    Flags_0.0 (Electronic Manual: 0=None?, 1=Yes?)
      011h 1    Flags_0.1 (0)
      012h 1    Flags_0.2 (0)
      013h 1    Flags_0.3 (0)
      014h 4    TMD Content ID (aka filenumber for "000000xx.tmd" ?)
      018h 4    CMD Content ID (aka filenumber for "cmd\000000xx.cmd" ?)
      01Ch 1    Flags_1.0 (SD Save Data: 0=None?, 1=Yes?)
      01Dh 1    Flags_1.1
      01Eh 1    Flags_1.2
      01Fh 1    Flags_1.3
      020h 4    Extdata ID low (zero if title doesn't use Extdata)
      024h 4    Reserved (0)
      028h 1    Flags_2.0 DSiWare Related (Visibility on Home Menu/Export Flag?)
      029h 1    Flags_2.1 ?
      02Ah 1    Flags_2.2 ?
      02Bh 1    Flags_2.3 ?
      02Ch 1    Flags_2.4 in DSiWare and in titles with an 'Application' Title ID
      02Dh 1    Flags_2.5 DSiWare Related (Visibility on Home Menu/Export Flag?)
      02Eh 1    Flags_2.6 ?
      02Fh 1    Flags_2.7 ?
      030h 10h  Product Code (eg. "CTR-N-HASJ", "", or "DS INTERNET", zeropadded)
      040h 10h  Reserved (0)
      050h 4    Unknown (32bit random/checksum/id/whatever)
      054h 2Ch  Reserved (0)

Notes
"It is important to note the database doesn't contain a hash of the .cmd. So if a user has more than one valid set of application data for a given .cmd Content ID they can be manually interchanged without issue. Though renaming a .cmd file to match the Content ID which the title.db is expecting will result in an error, as the CTR for the per-console encryption layer changes depending on the file path, and the MAC of the .cmd is probably generated with the .cmd Content ID in mind."
"These NAND/SD /dbs images seem to be loaded by the ARM9 while NATIVE_FIRM is booting."
"Removing ticket.db from a New3DS with signature checks disabled will not result in an unbootable system, however all icons except Slot-1 will disappear from Home. Applets can however still be used. Recovery can be accomplished via hardmod or arm9loaderhax plus a known good backup of the file (or the whole partition or disk); Gamecard exploits were not tested, and Browserhax did not work."

3DS Files - Title Installation Archive (CIA)

CIA Format (CTR Importable Archive)

      0000h 4      Header Size (usually 2020h bytes)
      0004h 2      Type        (seems to be always 0)
      0006h 2      Version     (seems to be always 0)
      0008h 4      Cert size   (0A00h, or 0=None)
      000Ch 4      Ticket Size (0350h, or 0=None)
      0010h 4      TMD Size    (0B34h+N*30h, or 200h=Dummy)
      0014h 4      Meta Size   (3AC0h, or 200h=Dummy, 8=CVer USA, or 0=None)
      0018h 8      APP Size    (can contain multiple contents, see TMD)
      0020h 2000h  APP Flags   (64Kbit/flags, usually 80h or C0h plus zeropadding)
      2020h 20h    Zerofilled  (padding to 40h-byte boundary)
      2040h [08h]  Certificate chain
      ...   ..     Zerofilled  (padding to 40h-byte boundary)
      ...   [0Ch]  Ticket file
      ...   ..     Zerofilled  (padding to 40h-byte boundary)
      ...   [10h]  TMD file
      ...   ..     Zerofilled  (padding to 40h-byte boundary)
      ...   [18h]  APP file(s) (usually encrypted via ticket)
      ...   ..     Zerofilled  (padding to 40h-byte boundary)
      ...   [14h]  Meta file   (3AC0h, or 08h, or 0=None) (if any)
      ...   ..     Zerofilled  (padding to 40h-byte boundary)

Certificate Chain (A00h bytes, with three certificates)

      RSA-4096 for below certificates (Retail=CA00000003, or Dev=CA00000004)
      RSA-2048 for Ticket signature   (Retail=XS0000000c, or Dev=XS00000009)
      RSA-2048 for TMD signature      (Retail=CP0000000b, or Dev=CP0000000a)

The same three certificates are also stored in certs.db,
3DS Files - Title Certificates (certs.db)
Ticket (350h bytes), with decrypt key for APP file(s)
3DS Files - Title Ticket (ticket.db)
TMD (B34h+N*30h bytes), contains info about the separate APP file(s)
3DS Files - Title Metadata (TMD)
APP file(s)
This region can contain one or more contents (eg. separate .app files for executable and manual, with .app sizes as listed in the TMD file; the .app files can be 3DS NCCH images, or DSiware images, or DSi datafiles like DS Cart Whitelist).
The .app contents are usually encrypted using the ticket's titlekey (see the Ticket chapter for details).

      There are two unencrypted variants:
      1) Encryption can be disabled in Content Type flags in the TMD file (that's
         done in most or all homebrew CIA's like ctrQuake.cia)
      2) Pre-retail prototype CIA's from mid 2010 didn't include tickets, and are
         thus unencrypted (the Ticket Size entry in CIA header is probably zero?)

Meta (3AC0h bytes) (if any)

      0000h 30h*8 Dependency module list    ;from NCCH Exheader ;NCCH[240h]
      0180h 180h  Reserved (0)
      0300h 4     Core version              ;from NCCH Exheader ;NCCH[408h?]
      0304h FCh   Reserved (0)
      0400h 36C0h SMDH Icon/Title           ;from NCCH ExeFS    ;ExeFS:\icon

The above data block is only present for NCCH executables (DSiware files and NCCH data files don't have the Exheader and ExeFS).
3DS NCCH Extended Header
3DS Files - Video Icons (SMDH)
Meta (8 bytes) (CVer USA)
Seems to contain a copy of the "CVer - RomFS:\version.bin" file.
3DS Files - Version (CVer and NVer)
Confusingly, the japanese system update contains 000400db00017202.cia (that name would be CVer USA, but the file contains CVer JPN). And confusingly, the system update doesn't contain any NVer file (unknown if/how it is updating NVer).
APP Flags
This appears to be a 64Kbit array with flags for Content Index 0000h..FFFFh (the first flag for index 0000h being located in bit7 of first byte).
The number of contents and content indices are found in the TMD file (most titles have only 1 or 2 contents, so the first flag byte is usually 80h or C0h, followed by 1FFFh zero bytes).
Unknown if these flags are used for anything... maybe there are cases where the TMD list multiple APPs, but only one of them being updated in the CIA?

     ___________________________________ Blurp ____________________________________

Overview
CIA format allows the installation of titles to the 3DS. CIA files and titles on Nintendo's CDN contain identical data. As a consequence, valid CIA files can be generated from CDN content. This also means CIA files can contain anything that titles on Nintendo's CDN can contain. Uh, what is a CDN?
Under normal circumstances CIA files are used where downloading a title is impractical or not possible. Such as distributing a Download Play child, or installing forced Gamecard updates. Those CIA(s) are stored by the titles in question, in an auxiliary CFA file.
Development Units, are capable of manually installing CIA files via the Dev Menu.
Format
The CIA format has a similar structure to the Wii's WAD format (aka DSi Tad?).
The file is represented in little-endian.
The data is aligned in 40h-byte blocks (if a content ends at the middle of the block, the next content will begin from a new block).

     _____________________________ System Update CFA ______________________________

This system update CFA contains the below files in the RomFS. This CFA is stored in the NCSD system-update partition (partition 7), the data from this CFA RomFS can also be transferred for Download Play when the client needs updated.

      ROM Cart NCSD Partition 6, NCCH RomFS:\SNAKE\cup_list  ;\New3DS System Update
      ROM Cart NCSD Partition 6, NCCH RomFS:\SNAKE\*.cia     ;/
      ROM Cart NCSD Partition 7, NCCH RomFS:\cup_list        ;\Old3DS System Update
      ROM Cart NCSD Partition 7, NCCH RomFS:\*.cia           ;/

cup_list
This uses the same format as the CVer cup_list, this system-update CFA cup_list contains the titleIDs for all of the titles stored in this RomFS.
3DS Files - Version (CVer and NVer)
<titleID>.cia
This is the CIA for each system-update title, for retail gamecards these CIAs are generated from the titles available on CDN at the time the NCSD image was finalized. The latest version(at the time of CFA generation) of every system title from CDN is stored here, excluding titles with the title-versions for 1.0.0-0.
New3DS
New3DS system-update partitions are located at partition6 in gamecards. The RomFS contains a "SNAKE" directory, the contents of that directory have the same structure as the Old3DS sysupdate CFA RomFS.

     _____________ Old CIA Formats (some pre-retail prototype stuff) ______________

24/06/2010 - CTR_SDK: 0_10

      000h 4     Archive Header Size (Usually = 0x2020 bytes)
      004h 2     Type
      006h 2     Version
      008h 4     Unused (aka size=0, or what?)                    (no Cert)
      00Ch 4     Unused (aka size=0, or what?)                    (no Tick)
      010h 4     Zero Filled Data (usually 0x200 bytes in length) (no TMD)
      014h 4     Zero Filled Data (usually 0x200 bytes in length) (no Meta)
      018h 8     APP file size
      020h 2000h Content Index

The order of the sections in the CIA file:

      * Header
      * Zero Data (aka dummy TMD?)
      * Zero Data (aka dummy Meta?) (but here with Meta in front of APP area!?)
      * APP file data (unencrypted, as there's no ticket with titlekey)

Only one executable supported. Uh, are there MORE than one "executable" supported in later versions??? With different title IDs??? But that would somewhat require multiple TMD's and Ticket's?
06/07/2010 - CTR_SDK: 0_10_2

      000h 4     Archive Header Size (Usually = 0x2020 bytes)
      004h 2     Type
      006h 2     Version
      008h 4     Unused (aka size=0, or what?)           (no Cert)
      00Ch 4     Ticket size
      010h 4     TMD file size
      014h 4     Unused (aka size=0, or what?)           (no Meta)
      018h 8     APP file size
      020h 2000h Content Index

The order of the sections in the CIA file:

      * Header
      * Ticket
      * TMD
      * APP file data

Very similar to the final CIA version (encryption, TMD, etc), except there is no embedded Certificate Chain.
Late 2010
The final version was invented in late 2010 (and, with the 3DS being released in 2011, retail CIA's are probably always using the final version).

3DS Files - Title Homebrew Executables (3DSX)

The 3DSX format is a homebrew executable file format. The main feature is having relocateable code, which may have been required for some older exploits that didn't provide full control of the virtual memory mapping.
As such, the .3dsx format is no longer useful (at least not once when having installed a bootloader), and one could instead use regular .code, .firm, .ncch, or .cia files for homebrew.
3DSX File Format
Header:

      00h  4   ID "3DSX"
      04h  2   Header size (20h or 2Ch)
      06h  2   Relocation Header size (unspecified purpose) (always 8)
      08h  4   Format version         (unspecified purpose) (always 0)
      0Ch  4   Flags                  (unspecified purpose) (always 0)
      10h  4   Code Segment Size
      14h  4   Rodata Segment Size
      18h  4   Data Segment Size (including bss)
      1Ch  4   Bss Segment Size

Extended Header (when [04h]>20h):

     (20h) 4   Icon/Title Offset       (or ?=None)
     (24h) 4   Icon/Title Size (36C0h) (or ?=None)
     (28h) 4   RomFS Offset            (or 0=None)

Relocation Header(s)

      ..   4   Number of absolute Code relocations   (=maybe num skip/patch pairs?)
      ..   4   Number of relative Code relocations   (unknown purpose, always 0)
      ..   4   Number of absolute Rodata relocations (=maybe num skip/patch pairs?)
      ..   4   Number of relative Rodata relocations (unknown purpose, always 0)
      ..   4   Number of absolute Data relocations   (=maybe num skip/patch pairs?)
      ..   4   Number of relative Data relocations   (unknown purpose, always 0)

Segments

      ..   ..  Code Segment
      ..   ..  Rodata Segment
      ..   ..  Data Segment (whatever... maybe excluding bss?)

Relocation Tables

      ..   ..  Code Relocation Table
      ..   ..  Rodata Relocation Table
      ..   ..  Data Relocation Table

Optional (when [04h]>20h):

      ..   ..  Icon/Title (SMDH Format)
      ..   ..  RomFS      (RomFS Directory/File area, without IVFC header+SHA's)

Unknown how the executable could access the RomFS (it might be loaded to some RAM address, which would be a waste of memory) (or otherwise the executable would need to know the path\filename of the 3dsx file).
Relocation Table (entries?):

      00h  2   Number of words to skip
      02h  2   Number of words to patch

Unknown what this does. The file is probably meant to be originated at a fixed base address (maybe zero?), and one would add the actual load address to any such "absolute" addresses? And do whatever on "relative" addresses?
Note
Some 3DSX files can be found at:
http://www.3dbrew.org/wiki/Homebrew_Applications

3DS Files - Client Cert/Key (ClCertA)

ClCertA (title id: 0004001b00010002) contains the following encrypted files:

      RomFS:ctr-common-1-cert.bin   ;default SSL client cert
      RomFS:ctr-common-1-key.bin    ;default SSL client private key

The .bin files are AES-CBC encrypted using keyslot 0Dh (as set by bootrom): 000h 10h IV value for AES-CBC ;-IV value for decrypt

      010h LEN  DER file (LEN=filesize-20h-PAD)             ;\
      xxxh PAD  Padding to 10h-byte boundary (zerofilled)   ; AES-CBC encrypted
      xx0h 1    Size of above padding (PAD)                 ; (keyslot 0Dh)
      xx1h 0Fh  Padding to 10h-byte boundary (zerofilled)   ;/

The decrypted files are in .der format:
DSi SD/MMC Firmware Certificate/Keys (DER)
The files are used by SSL module, the retail cert name is "CTR Common Prod 1".
The following servers require usage of ClCertA to connect:

      https://account.nintendo.net/          ;Account/OAuth2 related
      https://ccif.ctr.shop.nintendo.net/    ;CreditCardInfo/transaction? related
      https://ecs.c.shop.nintendowifi.net/   ;ECommerce SOAP, ticket-related
      https://cas.c.shop.nintendowifi.net/   ;Cataloging SOAP
      https://ninja.ctr.shop.nintendo.net/   ;eShop-related
      https://nus.c.shop.nintendowifi.net/   ;NetUpdate SOAP, used by NIM module

3DS Files - CTCert

Below seems to describe "CTCert".
Uh, unknown if/where this "CTCert" is stored?
Maybe it exists only after having connected to the shop at least once (similar to DSi's dev.kp)?
Or maybe it's a slightly reformatted copy of the Decrypted OTP, maybe only temporarily stored in RAM?
Or maybe below does describe .ctx file format rather than CTCert format?
The console-unique CTCert is used for signing CTX files (uh, really signing them? with a public key??), the DeviceCert used by eShop, and for DSiWare exports. This ECDSA signature, the ECDSA private key for this cert, and the IssuerID is loaded from memory initialized by bootrom instead of NAND. This is the 3DS equivalent of the DSi TWCert (aka the "TW cert" in DSi "Tad" files?).
The CTCert is signed with ECDSA by Nintendo. CTCerts can be verified via a DER stored in NATIVE_FIRM, separate DERs are used for retail and dev/debug.
Structure

      000h 4     Signature Type (00010005h)
      004h 3Ch   Signature ECDSA
      040h 40h   Signature padding/alignment (zerofilled)
      080h 40h   Signature Name (retail="Nintendo CA - G3_NintendoCTR2prod")
                                (dev="Nintendo CA - G3_NintendoCTR2dev")
      0C0h 4     Key Type
      0C4h 40h   Key Name "CT<DeviceId>-<ConsoleType>"  aka "CTxxxxxxxx-xx"?
                   DeviceId is the hex DeviceId (aka Decrypted OTP[04h..07h]?)
                   ConsoleType is "00"=retail, "01"=dev
      104h 04    Key Expiration UNIX Time, big endian (seconds since 1 Jan 1970 ?)
      108h 3Ch   Key Public ECDSA Key (point X,Y)
                   "This is two consecutive u8 arrays (each one of length 1Eh),
                   where the first one corresponds to the ECDSA R coordinate,
                   and the second to ECDSA S coordinate. These are in big endian."
      144h 3Ch   Key padding/alignment (zerofilled)

The ECDSA public key for this cert is converted from the ECDSA private key initialized by bootrom (uh, that's probably meant to be from Decrypted OTP). The curve used for ECDSA is sect233r1.

3DS Files - Dictionary (NJDC)

NJDC files contain dictionaries (maybe for spellchecking?), NJDC files are found in:

     Shared Data Archives: Dictionary (RomFS:\..\*.a) ;for console/region languages
     System Applets: 3DS Browser applet (RomFS:\iwnn\..\*.a) ;for all languages

Dictionary Format
The files contain a header and several large tables. The header size (and the location/presence of the header entries) varies from file to file; possibly depending on some header flags?
All values, offsets and UTF-16 chars are BIG-ENDIAN.

      000h 4    Header ID ("NJDC")
      004h 2    Unknown (1 or 2)
      006h 2    Unknown (0 or 1)
      008h 2    Unknown (4 or 5 or 0Fh)
      00Ah 2    Unknown (0)
      00Ch 4    Total Filesize minus a few bytes?
      010h 4    Unknown (00xxh)
      014h 4+4  Unknown (00xxh,00xxh) (usually both the same value)
      01Ch 4    Unknown (00xxh)
      ...  ..   ???
      ...  4    Offset to 10-byte Table
      ...  4    Offset to UTF-16 Strings
      ...  4    Offset to 2-byte Table
      ..   ..   Some zeroes and offsets?
      ...  4    Offset to 2 bytes? (08h,06h)
      ...  4    Values 00h,01h,01h,01h
      ...  4    Values 00h,01h,01h,01h
      ...  ..   ???
      ...  4    Number of words (N) ?
      ...  ..   ???
      ...  ..   4-byte Table (maybe some lookup table?)
      ...  2    2 bytes? (08h,06h)
      ...  N*10 10-byte Table (see below)
      ...  ..   UTF-16 Strings (raw strings, without trailing zeroes)
      ...  N*2  2-byte Table (values 0101h*(40h..7Dh)?) (flags/lookup?) (if any)
      ...  4    Footer ID ("NJDC") (can be unaligned)

10-byte Table:

      000h 1    String Length in bytes (always even, since chars are UTF-16)
      001h 3    String Offset (relative to String Table base)
      004h 6    Zerofilled

Bad Word List
Roughly related, there is Bad Word list in

      System Data Archives 2, NGWord (RomFS:*.txt)

The .txt files are UTF-16 (starting with FFh,FEh byte-order-marker).

3DS Files - Guide (GBIN)

GBIN Files are found in 3DS Camera & 3DS Sound (RomFS:\res\Guide*.gbin).
The files contain several "T_xxx" and "D_xxx_y" strings, bundled with unknown small numbers.
Purpose is unknown, maybe some Tree structure, or a list of Chapters (T) and Pages (D).
The files contain no real data, so they do probably refer to whatever other files, ie. translating names to file indices and/or assigning attributes.
GBIN Format

      000h 4     ID "GBIN"
      004h 4     Number of GUID entries
      008h ..    GUID entries

GUID entry format:

      000h 4     ID "GUID"
      004h 4     Number of D-entries
      008h 4     Unknown (0 or 1 or 2)
      00Ch 4     Unknown (0 or 1 or 2)
      010h 4     Unknown (0..0Fh?)
      014h 0Ch   Unknown (0)
      020h 10h   T-Name ("T_001" and up, zeropadded)
      030h N*14h D-Entries

D-Entry Format:

      000h 10h   D-NAME ("D_001_0" and up, zeropadded)
      010h 4     Unknown (0..04h?)

3DS Files - Version (CVer and NVer)

3ds:\title\000400db System Data Archives 2 - NVer and CVer

      NVer - RomFS:\version.bin        ;exists always (revision number)      ;-NVer
      CVer - RomFS:\version.bin        ;exists always (major.minor version)  ;\
      CVer - RomFS:\cup_list           ;exists only before 8.0.0-18          ; CVer
      CVer - RomFS:\masterkey.bin      ;exists in 7.2.0-17 and up            ;
      CVer - RomFS:\titleversion.txt   ;exists in 9.6.0-X and up             ;/

See also:
3DS FIRM Versions
http://www.3dbrew.org/wiki/Home_Menu <-- more versions!
NVer - RomFS:\version.bin (8 bytes)
This 8-byte file mainly contains the system revision number, for the version number displayed by System Settings. The rest of the data used for the system version is contained in CVer.

      000h 2     Reserved (0)
      002h 1     Revision version number (0..45) (the version's -N suffix)
      003h 1     Reserved (0)
      004h 1     ASCII character for the system version region (eg. "J"=Japan)
      005h 3     Reserved (0)

Note: The NVer "revision" number does usually increase alongsides with the "major.minor" number in CVer (but some updates have only either one of those increased).
CVer - RomFS:\version.bin (8 bytes)
This 8-byte file contains most of the data used for displaying the system version in System Settings. Format of the system version: "major.minor.build-revision region".

      000h 1     Build version number (0)
      001h 1     Minor version number (0..13)
      002h 1     Major version number (1..11)
      003h 1     Reserved (0)
      004h 1     ASCII character for the system version region (eg. "J"=Japan)
      005h 3     Reserved (zeroes, or same as [000h..002h])

CVer - RomFS:\cup_list (800h bytes) (exists only before 8.0.0-18)

      000h N*8   TitleID list of system titles (8 bytes each)   ;eg. 127 titles
      ...  ..    Zerofilled (padding to 800h-byte filesize)

This list doesn't contain all system titles, though most are contained in this list.
This file was removed from the CDN CVer RomFS, starting with 8.0.0-18.
A similar "cup_list" file is bundled with System Update CIA's:
3DS Files - Title Installation Archive (CIA)
CVer - RomFS:\masterkey.bin (40h bytes, exists in 7.2.0-17 and up)

      000h 1     Region (00h=Japan, 01h=USA, 02h=EUR, etc.)
      001h 1     Version (0Ah=v7.2, 0Bh=v8.0, etc.)
      002h 0Eh   Zerofilled
      010h 10h   AES IV value for decrypting below key
      020h 20h   Encrypted HMAC key

This file is used by System Settings. The HMAC key is decrypted using AES-CTR using a key from "mset .rodata" and the above IV value.
CVer - RomFS:\titleversion.txt (ASCII 5-7 bytes) (exists in
Added with 9.6.0-X.
With 9.6.0-X, this is a 5-byte file containing the following: "9.6.7". This is the parsed version of the CVer TMD title-version.
After USA 9.6.0-X for <=v11.0, this matches the version from CVer version.bin.

3DS Files - CRR0 and CRO0 Files

CRO0 and CRR0 files are reportedly somehow related, but unknown how exactly.

      System Tools: Nintendo Network ID Settings and System Applets: Miiverse have
        "RomFS:\.crr\static.crr" ;-CRR0 (whatever)
        "RomFS:\cro\static.crs"  ;-CRO0 (without actual code/data in there)
      System Data Arvives 1: web-lot/OSS CROs has
        "RomFS:\cro2\oss.cro"    ;\both are CRO0's (with code/data each)
        "RomFS:\cro2\webkit.cro" ;/(but without any CRR0 file)
      System Applets 3DS Browser has
        "RomFS:\.crr\static.crr" ;-CRR0 (whatever)
        "RomFS:\*.cro.lex        ;-several LZ11 compressed .cro's
        "RomFS:\static.crs"      ;-CRO0 (without actual code/data in there)

Unknown if/where any more such files exist.

     _________________________________ CRR0 Files _________________________________

CRR0 Files (must be stored under "RomFS:\.crr\")

      000h 4     ID "CRR0"
      004h 4     Reserved (0)
      008h 4     Next loaded CRR       ;\must be zero in file,
      00Ch 4     Previous loaded CRR   ;/set by RO during loading
      010h 4     Debug Info Offset (usually 0=None)
      014h 4     Debug Info Size   (usually 0=None)
      018h 8     Reserved (0)
      020h 4     UniqueID Mask    (eg. F00000FFh)
      024h 4     UniqueID Pattern (eg. zero)
      028h 18h   Reserved (0)
      040h 100h  RSA-2048 modulo (for signature at 240h..33Fh)
      140h 100h  RSA-2048 signature over [020h+(0..11Fh)] signed by Nintendo
      240h 100h  RSA-2048 signature over [340h+(0..357h?)]   (uh, why that size?)
      340h 4     Process UniqueID<<8, from the ProgramID
      344h 4     Total Filesize
      348h 8     Reserved (0)
      350h 4     Hash-table Offset (usually 360h)
      354h 4     Hash-table Number of Entries (uh, 2 when having only 1 .crs file?)
      358h 4     Plain region Offset containing text tags, from process NCCH
      35Ch 4     Plain region Size
      360h 20h*N Hash-table (SHA256's on first 80h-bytes of CRO0's) (or not so??)
      ...  ..    Plain region (some SDK strings) (does that have any purpose?)
      ...  ..    Padding to 1000h-byte boundary (CCh-filled)

Each hash stored in the hash-table is over the (which?) corresponding executable CRO0 hash-table.

     _________________________________ CRO0 Files _________________________________

CRO with extension .cro is used for "DLLs". CRS with extension .crs is in the same format of CRO but storing the symbol information of the static module (the main application) (uh, aka the "ExeFS:\.code" file?) (uh, and, importantly, .crs files seem to contain only symbols and stuff (and empty code/data sections)).
CRO0 Files (.cro and .crs)

      000h 20h  SHA256 on CRO0 header bytes 080h..17Fh         ;\
      020h 20h  SHA256 on code area (offset/size at [0B0h])    ; hash-table,
      040h 20h  SHA256 on ?                                    ; verified by CRR
      060h 20h  SHA256 on .data area (offset/size at [0B8h])   ;/
      080h 4    ID "CRO0"
      084h 4    Name offset (same as [0C0h])
      088h 4    Zero (changed to Next loaded CRO pointer by RO during loading)
      08Ch 4    Zero (changed to Prev loaded CRO pointer by RO during loading)
      08Ch 4    Previous loaded CRO pointer, set by RO during loading
      090h 4    Total Filesize
      094h 4    .bss size
      098h 4    Unknown
      09Ch 4    Unknown
               Below four words are "Segment offset" (FFFFFFFFh if not exists)
      0A0h 4    Export symbol "nnroControlObject_" offset (FFFFFFFFh in .crs)
      0A4h 4    Function "OnLoad" (called on init)
      0A8h 4    Function "OnExit" (called on exit)
      0ACh 4    Function "OnUnresolved" (called on unresolved function calls)
      0B0h 4+4  Code Section                offset, size
      0B8h 4+4  .data Section               offset, size
      0C0h 4+4  Module Name                 offset, size
      0C8h 4+4  Segment Table               offset, num (size=num*12)
      0D0h 4+4  Named Export Table          offset, num (size=num*8)
      0D8h 4+4  Indexed Export Table        offset, num (size=num*4)
      0E0h 4+4  Export Strings              offset, size
      0E8h 4+4  Export Tree (fast lookup)   offset, num (size=num*8) (trie-like)
      0F0h 4+4  Import Module Table         offset, num (size=num*20)
      0F8h 4+4  Import Patches              offset, num (size=num*12)
      100h 4+4  Named Import Table          offset, num (size=num*8)
      108h 4+4  Indexed Import Table        offset, num (size=num*8)
      110h 4+4  Anonymous Import Table      offset, num (size=num*8)
      118h 4+4  Import Strings              offset, size
      120h 4+4  unk8                        offset, num
      128h 4+4  Relocation Patches          offset, num (size=num*12)
      130h 4+4  unk9                        offset, num
      138h 48h  Zerofilled
      ...  ..   Code Section, etc. (in whatever order)
      ...  ..   Padding to 1000h-byte boundary (CCh-filled)

Segment offset (4 bytes) (used at [0A0h..0AFh], and also in many Table's)

      Bit0-3     Segment index for table
      Bit4-31    Offset into segment

Segment Table entry (12 bytes)

      000h 4     Segment offset
      004h 4     Segment size
      008h 4     Segment id (0=.text, 1=.rodata, 2=.data, 3=.bss)

Named Export Table entry (8 bytes)

      000h 4     Name offset
      004h 4     "Segment offset" for export

Indexed Export Table entry (4 bytes)

      000h 4     "Segment offset" for export

Named Import Table entry (8 bytes)

      000h 4     Name offset
      004h 4     Offset of the head of a linear list that contains the
                      patches for this import

Indexed Import Table entry (8 bytes)

      000h 4     Index of the export symbol
      004h 4     Offset of the head of a linear list that contains the
                      patches for this import

Anonymous Import Table entry (8 bytes)

      000h 4     "Segment offset" of the export symbol
      004h 4     Offset of the head of a linear list that contains the
                      patches for this import

Import Module Table entry (20 bytes)

      000h 4     Module name offset
      004h 4     Indexed import num
      008h 4     Offset of the head of a sub list in Indexed Import Table
      00Ch 4     Anonymous import num
      010h 4     Offset of the head of a sub list in Anonymous Import Table

Patch entry (12 bytes)

      000h 4     "Segment offset" for output.
      004h 1     Patch type (apparently a subset of relocation type for ARM ELF):
                   0=nothing/ignore
                   2=38=write u32 absolute (base+addend)
                   3=write u32 relative (base+addend-in_ptr)
                   10=THUMB branch
                   28=ARM32 branch
                   29=modify ARM32 branch offset
                   42=write u32 relative (((signed int)base*2)/2+addend-in_ptr)
                   other=err
      005h 1     For import patches, non-zero if last entry; for relocation
                 patches, this is the referred segment index
      006h 1     For import patches, 1 is written to first entry if all symbols
                 loaded successfully; unknown (padding?) for relocation patches
      007h 1     Unknown (padding?)
      008h 4     addend

ARM32 branch instruction is constructed as follows:

      If addend > 02000000h or addend < FE000000h, then skip.
      If (addend&1) == 1 then write "b +4" (nop).
      Else write as normal.

Unknown what "addend" means... addition offset? end of addition?
When the RO module loads the entire CRO into process memory (mapped in the 00100000h-04000000h region), it modifies the mapped CRO data. The magic field is also changed to "FIXD" if fix level is not 0.
Upon loading, the RO module will look for export symbol "nnroAeabiAtexit_" to patch it to its import symbol "__aeabi_atexit".

3DS Files - Archive DARC

DARC archives are used in various places, sometimes uncompressed, or often with LZSS or LZ11 compression. For example,

      Uncompressed DARC     Manual.bcma file (e-manual)
      LZSS compressed DARC  .arc files (nested with within above .bcma file)
      LZ11 compressed DARC  NCCH Logo (in NCCH Header, or NCCH ExeFS:\logo)
      LZ11 compressed DARC  .arc.LZ files (eg. in 3DS Camera RomFS "lyt" folder)

The DARC format is about same as the Wii's U8 format (with different header, different byte-order, and UTF-16 instead of ASCII names).
DARC header

      000h 4    ID "darc"
      004h 2    Byte Order (FEFFh)
      006h 2    Header Size (001Ch)
      008h 4    Version (01000000h)
      00Ch 4    Total Filesize (excluding trailing 20h-byte SHA256-HMAC, if any)
      010h 4    Offset of File/Folder List (usually 1Ch)
      014h 4    Size of File/Folder List, PLUS File/Folder Name Area
      018h 4    Offset of File Data Area
      ..   ..   File/Folder List (0Ch bytes per file/folder)
      ..   ..   File/Folder Name Area (UTF-16)
      ..   ..   File Data Area (usually each file is 20h-byte aligned)
     (..) (20h) Trailing SHA256-HMAC, if any (this is NOT 20h-byte aligned)

Root/Dot Entries (first 1-2 entries in File/Folder List)

      Entry0: Type=Folder, Name="", Offset=0, End=TotalNumDirEntries  ;Root
      Entry1: Type=Folder, Name=".", Offset=0, End=TotalNumDirEntries ;Dot (if any)

Entry0/Root is important to know the total directory size, and to compute the begin of the Name Area:

      NameArea = FileFolderList + TotalNumDirEntries*0Ch

Entry1/Dot is somewhat useless, but it does exist in most (not all) darc files, ie. the path strings can appear as so:

      darc:\.\dir\subdir\file       ;<-- ugly, but used in most darc files
      darc:\dir\subdir\file         ;<-- nicer, used in a few darc files

It's best to hide the "." in path strings (ie. detect if Entry1 is a Folder, with name "." and same Offset/End as Entry0, and if so, skip/ignore it).
File/Folder List Entries (0Ch bytes per entry)

      000h 3    Name offset (24bit, relative to begin of Name Area)
      003h 1    Type        (00h=File, 01h=Folder)
     When Type=00h=File:
      004h 4    File offset (relative to begin if darc; NOT to begin of Data Area)
      008h 4    File size
     When Type=01h=Folder:
      004h 4    Folder Parent Index (0=Root, 1=Dot, Other=NestedSubdir's)
      008h 4    Folder End Index (entries up to excluding End Index are childs)

Special Cases
3DS Face Raiders RomFS:\hal\effect\kbb\kbb.dat doesn't have a "." dot folder.
3DS Mii Maker RomFS:\shaders\shader.arc has nested folders & empty folders.
3DS Activity Log RomFS:\P_UlcdTest_LZ.bin contains an empty darc.
Example

      64 61 72 63                            ;id "darc"
      FF FE 1C 00
      00 00 00 01
      28 65 00 00
      1C 00 00 00
      1C 04 00 00
      40 04 00 00
      00 00 00 01  00 00 00 00  15 00 00 00  ;00h folder ""
      02 00 00 01  00 00 00 00  15 00 00 00  ;01h folder "."
      06 00 00 01  01 00 00 00  09 00 00 00  ;02h folder "anim";\
      10 00 00 00  40 04 00 00  F8 00 00 00  ;03h              ;
      54 00 00 00  40 05 00 00  EC 00 00 00  ;04h              ;
      98 00 00 00  40 06 00 00  F8 00 00 00  ;05h              ;
      DC 00 00 00  40 07 00 00  CC 0C 00 00  ;06h              ;
      20 01 00 00  20 14 00 00  54 0C 00 00  ;07h              ;
      64 01 00 00  80 20 00 00  4C 02 00 00  ;08h              ;/
      A8 01 00 01  01 00 00 00  0C 00 00 00  ;09h folder "..." ;\
      B2 01 00 00  E0 22 00 00  A8 02 00 00  ;0Ah              ;
      E2 01 00 00  A0 25 00 00  3C 10 00 00  ;0Bh              ;/
      12 02 00 01  01 00 00 00  15 00 00 00  ;0Ch folder "..." ;\
      1C 02 00 00  00 36 00 00  28 04 00 00  ;0Dh              ;
      3E 02 00 00  80 3A 00 00  28 01 00 00  ;0Eh              ;
      60 02 00 00  00 3C 00 00  28 04 00 00  ;0Fh              ;
      82 02 00 00  80 40 00 00  28 08 00 00  ;10h              ;
      A4 02 00 00  00 49 00 00  A8 00 00 00  ;11h              ;
      C4 02 00 00  00 4A 00 00  28 08 00 00  ;12h              ;
      DC 02 00 00  80 52 00 00  28 02 00 00  ;13h              ;
      F4 02 00 00  00 55 00 00  28 10 00 00  ;14h              ;/
      00 00                                  ;name "",0000h
      2E 00 00 00                            ;name ".",0000h
      61 00 6E 00 69 00 6D 00 00 00          ;name "anim",0000h
      ...

3DS Files - Archive SARC

SARC archives contain only files, not folders. However, the filenames do usually contain slashes (eg. "bsnd/cursor.bcwav"), so software could split those names into folder+filename, if desired.
SARC is used by 3DS eShop Applet, RomFS:\layout\ and RomFS:\sound\.
SARC Header

      000h 4     ID "SARC"
      004h 2     Header Size (14h)
      006h 2     Byte Order (FEFFh)
      008h 4     Total Filesize
      00Ch 4     Data Offset (aka Size of SARC+SFAT+SFNT)
      010h 2     Unknown/version? (always 0100h)
      012h 2     Unknown/reserved? (0)
      ..   ..    SFAT Chunk (see below) (Directory)
      ..   ..    SFNT Chunk (see below) (Filename strings)
      ..   ..    Data

SFAT Chunk (File Allocation Table)

      000h 4     ID "SFAT"
      004h 2     Header Size (0Ch)
      006h 2     Number of FAT Entries
      008h 4     Filename Hash Multiplier (usually 65h)
      00Ch N*10h FAT Entries (10h bytes each)

FAT Entry Format:

      000h 4    Filename Checksum (sorted, with smallest checksum in 1st FAT entry)
      004h 2    Filename Offset (at SFNT+8+Offset*4)
      006h 2    File Attribute? (always 0100h)
      008h 4    File Data Start (at Data+Start)
      00Ch 4    File Data End   (at Data+End, aka Data+Start+Size)

The filename checksums are calculated as follows:

      sum=0, for i=0 to namelen-1, sum=(sum*hash_multiplier)+name[i], next i

SFNT Chunk (Filename Table)

      00h 4    ID "SFNT"
      04h 2    Header Length (08h)
      06h 2    Unknown (padding?)
      08h ..   Filenames (ASCII, terminated by zero, on 4-byte boundaries)

File Data (at Offset specified in SARC[0Ch])
Files are at least 4-byte aligned (some SARCs do reportedly use 80h-byte alignment).
Tools
SARC Extractor/Creator with TAR-like command line flags. Can decompress a .zlib SARC file (4-byte size header + ZLIB data).

3DS Files - Archive arcless

arcless Format
This is a very simple archive format, found in some LZ-compressed files, eg. in 3DS Sound and 3DS Camera (RomFS:\lyt\C.LZ and RomFS:\shaders\shaders.LZ), 3DS Picture Picker (RomFS:\sound\csnd.LZ), and also in uncompressed form, eg. 3DS Sound (RomFS:\res\S.pack).

      000h+N*40h 38h     Filename (ASCII, zeropadded)                      ;\
      038h*N*40h 4       File Offset (always 80h-aligned)                  ;
      03Ch*N*40h 4       File Size                                         ; header
      ..         1       Zero (indicates end of directory)                 ;
      ..         ..      Zeropadding to 80h-byte boundary                  ;/
      xxx*80h    ..      File data (at above offsets)                      ;\data
      ..         ..      Zeropadding to 80h-byte boundary, after each file ;/

The header doesn't contain any ID (like "NARC", "SARC", or "darc" or so). However, one can more or less reliably detect it by checking for valid ASCII characters, zeropaddings, 1st Offset being located after the directory, further Offsets being located at Offset+Size+Alignment from previous entry, and with Offset+Size not exceeding the archive size.

3DS Files - Archive ZAR

ZAR Format (Zelda Archive, used in 3DS Zelda Ocarina of Time)

      000h 4      ID "ZAR",01h                                   ;\
      004h 4      Total Filesize                                 ;
      008h 2      Number of Filetype Entries    (T)              ;
      00Ah 2      Number of Files (of any type) (F)              ; header
      00Ch 4      Offset to Filetypes section (20h)              ;
      010h 4      Offset to Filesize/name section                ;
      014h 4      Offset to Fileoffset section                   ;
      018h 8      ID "queen",0,0,0                               ;/
      020h T*10h  Filetype Entries                               ;\type list
      ...  ..     Filetype Names and File List for each Filetype ;/
      ...  F*8    Filesize/Filename Entries                      ;\
      ...  ..     Filenames (ASCII, terminated by zero)          ; file list
      ...  F*4    Fileoffset Entries                             ;/
      ...  ..     File data...                                   ;-file data

Filetypes Entries

      000h 4    Number of Files for the Filetype (0=None)
      004h 4    Offset to File List for the Filetype (FFFFFFFFh=None)
      008h 4    Offset to Filetype name (eg. "unknown",0 or "zsi",0 etc.)
      00Ch 4    Unknown (always FFFFFFFFh)

The File List contains a list of 32bit File indices for the Filetype (0=1st file, 1=2nd file, etc).
The number of filetypes varies between 2 and 8 in known files. Known filetype names are:

      "anb",00h       boy/.../*.anb    ;eg. in actor\zelda_link_child_ultra.zar
      "ccb",00h       ?
      "cmab",00h      misc/.../*.cmab
      "cmb",00h       Model/.../*.cmb  (or lowercase, model/.../*.cmb)
      "csab",00h      Anim/.../*.csab
      "ctxb",00h      tex/.../*.ctxb
      "faceb",00h     boy/.../*.faceb  ;eg. in actor\zelda_link_opening.zar
      "qdb",00h       demo/.../*.qdb   ;eg. in actor\zelda_horse.zar, scene\*.zar
      "tbd",00h       txt/.../*.tbd    ;eg. in kankyo\kankyo_common.zar
      "unknown",00h   Anim/.../*.cskla ;eg. in actor/zelda_magic_wind.zar
      "zsi",00h       collision/.../*.zsi

Type "unknown" does always exist as first type entry (even if it contains no files; the only archive containing an "unknown" file is actor/zelda_magic_wind.zar, which contains Anim/new_magic_wind.cskla).
Filesize/Filename Entries

      000h 4    File size
      004h 4    Offset to filename (ASCII, terminated by zero)

Fileoffset Entries

      000h 4    Offset to File data

Directories
The ZAR format doesn't directly support directories. However, most filenames contain slashes so one could split those into folder/filename.
Note: RomFS:\scene\*.zar does use "\" backslashes instead of "/" slashes, that, with some names starting with dot or dotdot (".\" or "..\..\").
If desired, one could also treat the ZAR's Filetypes section as top-level directories, or as filetype suffix (although "Model" and ".cmb" in filenames like "Model\filename.cmb" do already imply the type anyways).
Note
See https://wiki.cloudmodding.com/oot/Category:File_Formats for more Zelda fileformats (QBF, QCL, QM, etc).

3DS Files - CCAL Format (Hardware calibration, HWCAL)

The two HWCAL files contain (initial?) calibration values, the data is also stored in the system settings config file, unknown which of those three files contains the most up to date values for daily use.
3DS Files - Config Savegame
Reading
"If 0x1FF81006 (uh, what, where from?) is 3 or 4 or 7 or 8 or 9 then the calibration data is read from the EEPROM using the i2c:EEP service command 0x001000C0, using offset 0x000 for HWCAL0, and offset 0x800 for HWCAL1. Otherwise attempt is made to read CTRNAND:/ro/sys/HWCAL(0|1).dat instead."
Summary

      File Data  Size  ConfigInfoBlk Bit  Description
      000h -     200h  -             -    Header
      200h 000h  10h   00040000h     3    Touchscreen
      214h 014h  08h?  ???                Circle Pad (part 1)
      220h 020h  2     00050000h     1    Screen flicker
      224h 024h  1     00010000h     7    RTC Compensation Value
      228h 028h  1     ???                DSPRAM related
      230h 030h  8Ah   ???           2?   Camera position
      2BCh 0BCh  12h   00040002h     6    Gyroscope
      2D0h 0D0h  0Ch   00040003h     8    Accelerometer
      2E0h 0E0h  134h  00020000h     5    Codec (CDC)
      418h 218h  04h?  ???         null?  Programmable Infrared Transmitter (PIT)
      420h 220h  214h  00070000h     9?   3D filters ... maybe this is "Surround"?
      640h 440h  20h   ???           10   Power saving mode (ABL)
      670h 470h  20h   00050005h     11?  Stereo Display Settings
      6A0h 4A0h  38h   00050002h     12   Backlight PWM (BLPWM)
      6E0h 4E0h  18h   ???                Circle Pad extra (part 2)
      700h 500h  0Ch   ???                ???
      710h 510h  20h   ???                ???
      740h 540h  08h   ???         not?   MCU
      750h 550h  02h   00050006h   not11? 3D screen (ULCD) delay
      760h 560h  08h   00070002h   not?   Microphone echo cancellation
      770h 570h  10Ch  00050008h   not?   Power saving mode (ABL) extra
      880h 680h  08h   ???         not?   CStick (Right stick)
      890h 690h  18h   00180001h   null?  Quad Tracking Module (QTM)

Aging flags (for Header entry [00Eh])

      Bit     Description
      0       FCRAM (unknown, bit0 is usually zero)
      1       Screen flicker (always successful)
      2       Camera
      3       Touchscreen panel (always successful)
      4       Circle Pad (analog stick)
      5       Codec
      6       Gyroscope
      7       RTC Compensation Value
      8       Accelerometer
      9       Surround
      10      Power saving mode (ABL)
      11      3D screen (ULCD)
      12      Backlight PWM (BLPWM)
      13      Analog stick A (???)
      14      Camera extensions (?)
      15      Power saving mode (ABL) in legacy (DSi/GBA) mode

Unknown if these are actually test results, maybe they are just entry-present flags? With later entries instead indicated by "Value 0001h" in the newly added fields?
Header

      000h 4    File ID "CCAL"
      004h 4    Version (eg. Old3DS:0000000Dh, New3DS:00000012h)
      008h 4    Data size (always 07D0h, for entry 200h..9CFh)
      00Ch 1    Model version (?) (usually 00h)
      00Dh 1    CAL revision (incremented each time the CAL file is updated)
      00Eh 2    Bitmask of successful Aging tests (Old3DS:73FEh, New3DS:77FEh)
      010h 20h  SHA256HMAC (retail) or SHA256 (dev) of the data section
      030h 1D0h Zero

Touchscreen

      200h 2    s16 RawX0
      202h 2    s16 RawY0
      204h 2    s16 PointX0
      206h 2    s16 PointY0
      208h 2    s16 RawX1
      20Ah 2    s16 RawY1
      20Ch 2    s16 PointX1
      20Eh 2    s16 PointY1
      210h 2    Checksum?
      212h 2    Zero

Circle Pad (part 1)

      214h 2    s16 CenterX (usually 08xxh)
      216h 2    s16 CenterY (usually 08xxh)
      218h 4    Zero (hmmm, uncommonly... not set to Value 0001h ?)
      21Ch 2    Checksum?
      21Eh 2    Zero

Screen flicker

      220h 1    u8 FlickerTop                             (maybe for MCU[03h] ?)
      221h 1    u8 FlickerBottom                          (maybe for MCU[04h] ?)
      222h 1    Checksum ([220h] XOR FFh)
      223h 1    Checksum ([221h] XOR FFh)    ;uh, reportedly without XOR FFh ???

RTC Compensation Value

      224h 1    u8 Compensation Value (???) (usually 80h) (maybe for MCU[37h] ?)
      225h 1    Checksum ([224h] XOR FFh)
      226h 2    Zero

DSP-RAM related?

      228h 1    DSPRAM related (spotted FEh on Old3DS, 86h on New3DS)
      229h 1    Checksum ([228h] XOR FFh)
      22Ah 6    Zero

Camera position ;uh, for which of the three camera(s)?

      230h 4    u32 flags
      234h 4    float scale
      238h 4    float RotationZ
      23Ch 4    float TranslationX
      240h 4    float TranslationY
      244h 4    float RotationX
      248h 4    float RotationY
      24Ch 4    float ViewAngleRight
      250h 4    float ViewAngleLeft
      254h 4    float ChartDistance(???)
      258h 4    float CameraDistance
      25Ch 2    s16 ImageWidth
      25Eh 2    s16 ImageHeight
      260h 10h  u8 reserved[0x10]
      270h 40h  u8 ???[0x40]
      2B0h 2    s16 aeBaseTarget(???)
      2B2h 2    s16 kRL
      2B4h 2    s16 kGL
      2B6h 2    s16 kBL
      2B8h 2    s16 ccmPosition
      2BAh 2    Checksum?

Gyroscope

      2BCh 2    s16 ZeroX
      2BEh 2    s16 PlusX
      2C0h 2    s16 MinusX
      2C2h 2    s16 ZeroY
      2C4h 2    s16 PlusY
      2C6h 2    s16 MinusY
      2C8h 2    s16 ZeroZ
      2CAh 2    s16 PlusZ
      2CCh 2    s16 MinusZ
      2CEh 2    Checksum?

Accelerometer

      2D0h 2    s16 OffsetX
      2D2h 2    s16 ScaleX
      2D4h 2    s16 OffsetY
      2D6h 2    s16 ScaleY
      2D8h 2    s16 OffsetZ
      2DAh 2    s16 ScaleZ
      2DCh 2    Checksum?
      2DEh 2    Zero

Codec (CDC) (aka TSC)

      2E0h 1    u8 DriverGainHP       ;TSC[65h:0Ch].bit3-7
      2E1h 1    u8 DriverGainSP       ;TSC[65h:12h].bit2-7 and TSC[65h:13h].bit2-7
      2E2h 1    u8 AnalogVolumeHP     ;TSC[65h:16h] and TSC[65h:17h]
      2E3h 1    u8 AnalogVolumeSP     ;TSC[65h:1Bh] and TSC[65h:1Ch]
      2E4h 1    s8 ShutterVolume0     ;TSC[00h:41h] and TSC[00h:42h] ;\maybe camera
      2E5h 1    s8 ShutterVolume1     ;TSC[64h:7Bh]                  ;/sound fx?
      2E6h 1    u8 MicrophoneBias     ;TSC[65h:33h]
      2E7h 1    u8 QuickCharge (???)  ;TSC[65h:42h].bit0-1
      2E8h 1    u8 PGA_GAIN (mic)     ;TSC[65h:41h].bit0-5
      2E9h 3    u8 reserved[3]
      2ECh 1Eh  s16 FilterHP32[3*5]   ;TSC[0Bh:02h..1Fh] and TSC[0Bh:42h..5Fh]
      30Ah 1Eh  s16 FilterHP47[3*5]   ;TSC[0Bh:20h..3Dh] and TSC[0Bh:60h..7Dh]
      328h 1Eh  s16 FilterSP32[3*5]   ;TSC[0Ch:02h..1Fh] and TSC[0Ch:42h..5Fh]
      346h 1Eh  s16 FilterSP47[3*5]   ;TSC[0Ch:20h..3Dh] and TSC[0Ch:60h..7Dh]
      364h 38h  s16 FilterMic32[3+5*5];TSC[05h:08h..3Fh]
      39Ch 38h  s16 FilterMic47[3+5*5];TSC[05h:48h..7Fh]
      3D4h 38h  s16 FilterFree [3+5*5];TSC[08h:xxh, 09h;xxh, 0Ah:xxh]
      40Ch 1    u8 AnalogInterval     ;TSC[67h:27h].lsbs ;\
      40Dh 1    u8 AnalogStabilize    ;TSC[67h:19h].lsbs ;
      40Eh 1    u8 AnalogPrecharge    ;TSC[67h:17h].msbs ; Touchscreen/CirclePad
      40Fh 1    u8 AnalogSense        ;TSC[67h:17h].lsbs ;
      410h 1    u8 AnalogDebounce     ;TSC[67h:1Bh].lsbs ;
      411h 1    u8 Analog_XP_Pullup   ;TSC[67h:19h].msbs ;
      412h 1    u8 YM_Driver          ;TSC[67h:1Bh].msb  ;/
      413h 1    u8 reserved
      414h 2    Checksum?
      416h 2    Zero

Programmable Infrared Transmitter (PIT) -- New3DS only (zerofilled on Old3DS)

      418h 2    u16 VisibleFactor
      41Ah 2    u16 IRFactor
      41Ch 2    Value Zero (hmmm, uncommonly... not set to Value 0001h ?)
      41Eh 2    Checksum?

3D filters ;uh, is that 3d video? and/or 3d surround audio?

      420h 200h u16 SpecialFilter[0x100] <-- Old3DS: mostly zero, unlike New3DS
      620h 14h  u32 IIRSurroundFilter[5] <-- both Old3DS and New3DS
      634h 2    Checksum?
      636h 0Ah  Zero

Power saving mode (ABL)

      640h 4    u32 DitherPattern
      644h 2    s16 StartX
      646h 2    s16 StartY
      648h 2    u16 SizeX
      64Ah 2    u16 SizeY
      64Ch 2    s16 GTH_Ratio
      64Eh 1    u8 DitherMode
      64Fh 1    u8 MinRS
      650h 1    u8 MaxRS
      651h 1    u8 MinGTH
      652h 1    u8 MinMax (???)
      653h 1    u8 ExMax (???)
      654h 1    u8 inertia
      655h 9    u8 LutListRS[9]
      65Eh 2    u8 reserved[2]
      660h 2    Checksum?
      662h 0Eh  Zero

Stereo Display Settings

      670h 20h  Float values? (see config file)
      690h 2    Checksum?
      692h 0Eh  Zero

Backlight PWM (BLPWM) ;uh, which backlight/mode(s)? Upper2D, Upper3D, Lower?

      6A0h 24h  float coefficient[3][3]
      6C4h 1    u8 NumLevels
      6C5h 1    u8 padding
      6C6h 0Eh  u16 brightnesses[7]
      6D4h 2    u16 BaseDivisor
      6D6h 2    u16 MinimumBrightnessHw
      6D8h 2    Checksum?
      6DAh 06h  Zero

Circle Pad (part 2)

      6E0h 4    float ScaleX
      6E4h 4    float ScaleY
      6E8h 2    s16 MaxX
      6EAh 2    s16 MinX
      6ECh 2    s16 MaxY
      6EEh 2    s16 MinY
      6F0h 2    s16 type
      6F2h 6    u8 unknown_padding[6]
      6F8h 2    Checksum?
      6FAh 06h  Zero

Unknown ???

      700h 0Ch  ???
      70Ch 2    Checksum?
      70Eh 2    Zero

Unknown ???

      710h 20h  ???
      730h 2    Checksum?
      732h 0Eh  Zero

MCU

      740h 2    s16 SVR2_Min (???)
      742h 2    s16 SVR2_Max (???)
      744h 2    s16 VolumeSliderMin      (maybe for MCU[58h] ?)
      746h 2    s16 VolumeSliderMax      (maybe for MCU[59h] ?)
      748h 2    Value 0001h (?)
      74Ah 2    Checksum?
      74Ch 4    Zero

3D screen (ULCD) delay

      750h 1    u8 To2D
      751h 1    u8 To3D
      752h 2    Value 0001h (?)
      754h 2    Checksum?
      756h 0Ah  Zero

Microphone echo cancel

      760h 8    s8 params[8]
      768h 2    Value 0001h (?)
      76Ah 2    Checksum?
      76Ch 4    Zero

Power saving mode (ABL) extra -- New3DS only (zerofilled on Old3DS)

      770h 1    u8 MaxInertia
      771h 1    u8 pad
      772h 2    u16 PWM_CNT_EX
      774h 4    u32 Histogram1
      778h 4    u32 Histogram2
      77Ch 100h u32 adjust[0x40]
      87Ch 2    Value 0001h (?)
      87Eh 2    Checksum?

CStick (Right stick) -- New3DS only (zerofilled on Old3DS)

      880h 1    u8 ThinningCountX(???)
      881h 1    u8 ThinningCountY(???)
      882h 6    u16 reserved[3]
      888h 2    Value 0001h (?)
      88Ah 2    Checksum?
      88Ch 4    Zero

Quad Tracking Module (QTM) -- New3DS only (zerofilled on Old3DS)

      890h 4    float DivisorAtZero (???)
      894h 4    float TranslationX
      898h 4    float TranslationY
      89Ch 4    float RotationZ
      8A0h 4    float HorizontalAngle
      8A4h 4    float OptimalDistance
      8A8h 2    Value Zero (hmmm, uncommonly... not set to Value 0001h ?)
      8AAh 2    Checksum?
      8ACh 124h Zero

Unknown things
The HMAC key for header signature is unknown.
The Checksum function is unknown (for 1-2 byte sections it's just the 1-2 byte(s) XORed FFh).
The purpose of most entries is unknown.
Unknown how to read the EEPROM data (maybe similar as for Wifi EEPROM?).
Unknown what size EEPRM has (apparently at least 1000h bytes).
Unknown if EEPROM has any header (maybe only 30h bytes instead 200h bytes?).

3DS Files - Config Savegame

This page describes the format of the Cfg NAND savegame. These blocks can be accessed with the Cfg service commands.
The data is stored in "3ds:\data\<ID0>\sysdata\00010017\00000000" (which is a DISA file with SAVE filesystem, containing only one file, ie. the "config" file described below).
Structure of save-file "/config"

      Offset Size   Description
      0000h  2      Total entries (N) (usually 32h..41h)
      0002h  2      End of unused space, begin of Data (455Ch..41E4h)
      0004h  N*0Ch  Block entries
      ...    ...    Unused space
      455Ch         Data for the entries (used from top, starting at 7FFFh)

The filesize for this /config file is 0x8000-bytes.
Configuration block entry

      00h 4  BlkID (00xx000xh)
      04h 4  Offset to the data for this block when size is >4, otherwise
               this word is the data for this block
      08h 2  Size
      0Ah 2  Flags (usually 000Ch or 000Eh, unknown meaning)

Configuration blocks

      BlkID   Flags Size Description
      00000000h 0Ch 2    Config savegame version? (0015h or 0039h)
      00010000h 0Ch 1    RTC Compensation Value (usually 80h)
      00020000h 0Ch 134h Codec
      00030000h 0Ch 1    Leap Year Counter (read By PTM)
      00030001h 0Eh 08h  User time offset (read by CECD): displayed_time-rtc_time
      00030002h 0Ch 08h  Settings time offset: newly_set_time-rtc_time
      00040000h 0Ch 10h  Touch calibration (read by HID)
      00040001h 0Ch 1Ch  Analog Stick Calibration Param? (read by HID)
      00040002h 0Ch 12h  Gyroscope (read by HID)
      00040003h 0Ch 0Ch  Accelerometer (read by HID)
      00040004h 0Ch 1Ch  CStick calibration data
      00050000h 0Ch 2    Screen flicker
      00050001h 0Ch 2    Backlight controls (read by GSP)
                           (u8 ABL_powersave_enable, u8 brightness_level)
      00050002h 0Ch 38h  Backlight PWM (read by GSP)
      00050003h 0Ch 20h  Power saving mode (ABL) calibration (read by GSP)
      00050004h 0Ch 20h  Power saving mode (ABL) calibration
      00050005h 0Eh 20h  Stereo Display Settings (HWCAL block 0x470)
      00050006h 0Ch 2    3D switching delay (two bytes: To2D, To3D)
      00050007h 0Ch 4    ?
      00050008h 0Ch 10Ch Power saving mode (ABL) extra config
      00050009h 0Ch 08h  new3DS only(?) backlight control
                           (5th byte: auto-brightness enable)
      00060000h 0Ch 96h  ??? (HWCAL block 0x500) (but, that HWCAL is smaller?)
      00070000h 0Eh 214h 3D filters ... maybe this is "Surround"?
      00070001h 0Eh 1    Sound output mode (mono=0, stereo=1, surround=2)
      00070002h 0Eh 08h  Microphone echo cancellation params
      00080000h 0Ch C00h WiFi configuration slot 0
      00080001h 0Ch C00h WiFi configuration slot 1
      00080002h 0Ch C00h WiFi configuration slot 2
      00090000h 0Eh 08h  This contains a u64 ID, used by processes using
                           NWMUDS:InitializeWithVersion. The first word is the
                           same as LocalFriendCodeSeed, while the latter is a
                           separate word.
      00090001h 0Eh 08h  Same content as 0x0009000? This console-unique u64 is
                           used by GenHashConsoleUnique. It is generated by
                           ((3FFFFFFFFh) & LocalFriendCodeSeed) | (random16 << 48))
                           where random16 is generated by GenerateRandomBytes
      00090002h 0Eh 4    The first two bytes are the same random16 used in
                           0x00090001. The second two bytes are zeros.
      000A0000h 0Eh 1Ch  Username in UTF16
      000A0001h 0Eh 2    Birthday (u8 month, u8 day)
      000A0002h 0Eh 1    Language
      000B0000h 0Eh 4    CountryInfo
      000B0001h 0Eh 800h Country name in UTF-16, every 0x80-bytes is an entry for
                           each language, in the order of the Language table below
                           (not all entries are set)
      000B0002h 0Eh 800h State name in UTF-16, every 0x80-bytes is an entry for
                           each language
      000B0003h 0Eh 4    Coordinates. A pair of s16 represents latitude and
                           longitude, respectively. One need to multiply both
                           value by 180/32768 to get coordinates in degrees
      000C0000h 0Eh C0h  Restricted photo exchange data, and other info (includes
                           a mirror of Parental Restrictions PIN/Secret Answer)
      000C0001h 0Eh 14h  COPPACS restriction data
      000C0002h 0Eh 200h ? Contains the email address set during Parental
                            Restriction setup.
      000D0000h 0Eh 4    u16 at offset 0x0: EULA Version which was agreed to.
      000E0000h 0Eh 1    ?
      000F0000h 0Ch 10h  Debug configuration, read by NS on dev-units: on startup,
                           NS does svcKernelSetState(6, 1, (u64)debug_flags & 1);
                           svcKernelSetState(6, 2, (u64)debug_flags & 2); (see
                           here) where debug_flags is the u32 located at offset
                           0xC in this struct. Then it compares the u32 from +8 in
                           this config-block with the APPMEMTYPE. When those don't
                           match NS starts a FIRM-launch (with the same FIRM
                           titleID as the currently running one) to boot into a
                           FIRM with the APPMEMTYPE value from this config-block.
                           The byte at offset 0 is related to the memtype as well.
      000F0001h 0Ch 8    ?
      000F0003h 0Ch 1    ?
      000F0004h 0Ch 4    System-Model value byte, followed by 3 unknown bytes
      000F0005h 0Ch 4    The first u8 indicates whether network updates are
                           enabled (however, NIM only checks this flag with
                           developer ENVINFO).
      000F0006h 0Ch 28h  In NIM, taken as a (hopefully null terminated) string
                           used for the "X-Device-Token" http header field for
                           NPNS url.
      00100000h 0Ch 2    ?
      00100001h 0Ch 94h  Parental Restrictions PIN/Secret Answer and other info
      00100002h 0Ch 1    ?
      00100003h 0Ch 10h  ?
      00110000h 0Ch 4    The low u16 indicates whether the system setup is
                           required, such as when the system is booted for the
                           first time or after doing a System Format
                           (0=Setup required, non-zero=No setup required)
      00110001h 0Ch 8    TitleID of the menu to launch, used by NS on dev units
                           (this block can be edited on dev units with Config)
      00120000h 0Ch 8    Volume Slider Bounds (Read by HID and PTM)
      00130000h 0Eh 4    If response is 0x100 then debug mode is enabled.
      00150000h 0Ch 4    ?
      00150001h 0Ch 8    ?
      00150002h 0Eh 4    In NIM, taken as an u32, using the low u16, casted to a
                           char, and turned lower case for the making of the url
                           for NPNS.
      00160000h 0Eh 4    Unknown, first byte is used by config service-cmd
                           0x00070040. (Unknown whether the last 3-bytes are used)
      00170000h 0Eh 4    Miiverse (OLV) access key
      00180000h 0Ch 4    QTM Infrared LED related, can be 0 or 1 ... maybe "PIT"?
      00180001h 0Ch 18h  QTM calibration data
      00190000h 0Ch 1    Unknown. NFC-module checks for value1/non-value1.

The developer unit TID block (uh, what?) only exists on developer units.
Stereo Display Settings
All values are hard-coded in cfg module.

      00h    4    62.0f   assumed pupillary distance in mm?
      04h    4    289.0f  assumed distance in mm between player's eyes and
                            upper screen?
      08h    4    76.80f  width in mm    ;\size of Old3DS upper screen
      0Ch    4    46.08f  height in mm   ;/(doesn't vary for different models?)
      10h    4    10.0f
      14h    4    5.0f
      18h    4    55.58f
      1Ch    4    21.57f

Languages

      ID      Description (two letter code... and guessed meaning)
      0  =    JP Japanese
      1  =    EN English
      2  =    FR French
      3  =    DE German
      4  =    IT Italian
      5  =    ES Spanish
      6  =    ZH ...maybe a widespread chinese dialect...?
      7  =    KO Korean
      8  =    NL Dutch
      9  =    PT Portugese
      10 =    RU Russian
      11 =    TW ...maybe a taiwanese chinese dialect...?

CountryInfo

      00h 1   ?
      01h 1   ?
      02h 1   State/Province code
      03h 1   Country code, same as DSi/Wii country codes. Value 0xFF is invalid.

0x000A0000 Block

      00h 14h  UTF-16 username, with no NULL-terminator (uh, what if shorter?)
      14h 4    Usually zero?
      18h 4    u32 NGWord version the username was last checked with. If this
                 value is less than the u32 stored in the NGWord CFA
                 "romfs:/version.dat", the system then checks the username
                 string with the bad-word list CFA again, then updates this field
                 with the value from the CFA

WiFi Slot Structure

      000h   2     Unknown? (can be 0001h)
      002h   2     CRC-16 checksum of the next 410h bytes (unknown initial value)
      004h   88h   First network structure. Only set if the network was set
                     "normally", or was the last to be set using WPS during the
                     session
      08Ch   20h   Padding
      0ACh   88h   Second network structure. Only set if the network was set
                     using WPS, otherwise 0-filled
      134h   20Ch  Padding
      340h   1     Obtain IP, Gateway, Subnet (0=Manual, 1=Auto/DHCP)
      341h   1     Obtain DNS Server address  (0=Manual, 1=Auto/DHCP)
      342h   2     Padding ?
      344h   4     IP address               ;\
      348h   4     Gateway                  ; used only if [340h]=00h
      34Ch   4     Subnet Mask              ;/
      350h   4     Primary DNS Server       ;\used only if [341h]=00h
      354h   4     Secondary DNS Server     ;/
      358h   4     Always 0x01050000 ?      ;\     <-- rather 00000001h (!) or 501h
      35Ch   4     IP address to use        ; Only set if the network was the
      360h   6     MAC address of the AP    ; last to be set during the session.
      366h   1     Channel (range ?..?)     ;      <-- can be 06h,0Bh
      367h   1     Padding ?                ;/
      368h   1     Proxy Enable         (00h=None, 01h=Yes)
      369h   1     Proxy Authentication (00h=None, 01h=Yes)
      36Ah   2     Proxy Port (16bit)
      36Ch   30h   Proxy Name (ASCII string, max 47 chars, padded with 00's)
      39Ch   34h   Padding
      3D0h   20h   Proxy Authentication Username (ASCII string, padded with 00's)
      3F0h   20h   Proxy Authentication Password (ASCII string, padded with 00's)
      410h   2     Padding ?
      412h   2     MTU Value (Max transmission unit) (576..1500, usually 1400)
      414h   7ECh  Padding

Network structure (used twice in the above WiFi slot structure):

      00h   1     Whether the network was set or not?
      01h   1     Whether to use this network structure to connect?
      02h   1     Whether this structure is the first (0) or the second (1) in the
                    larger WiFi slot structure?
      03h   1     Padding ?
      04h   20h   SSID (ASCII string, padded with 00's) (see below for length)
      24h   1     SSID Length in characters (01h..20h, or 00h=unused)
      25h   1     AP crypto key type (maybe related to WEP/WPA bytes on NDS?)
      26h   2     Padding ?
      28h   40h   WPA/WPA2 password (ASCII string, padded with 00's)
      68h   20h   Precomputed PSK (based on WPA/WPA2 password and SSID)

The above data is (slightly reordered) also stored in Wifi FLASH:
DS Firmware Wifi Internet Access Points
The DSi did have support for six access points (3xWEP and 3xWEP/WPA), unknown if the old 3xWEP ones are still supported on 3DS, and if so, if they are also stored in the Config Samegame file.
LCD display config
There seems to be some sort of LCD display configuration stored in this cfg. When using the cfg-save from an Old3DS on a New3DS without formatting the cfg first, the bottom-screen display is somewhat off (which is fixed by formatting the cfg-save).
Parental control Block 0x00100001

      00h   0Dh  Unknown
      0Dh   4    PIN
      11h   20h  Secret answer in UTF-16

Parental Control setting block 0xC0000

      00h   4    Parental Control restriction bitmask
      04h   ...     ?
      0Ch   4    Parental Controls PIN code

Parental Control restriction bitmask (?=Allow, ?=Disallow)

      Bit     Restriction name
      0       Global Parental Controls enable
      3       Sharing Images/Audio/Video/Long Text Data
      4       Internet Browser
      5       StreetPass
      6       Friend Registration
      8       eShop
      10      Miiverse (view)
      11      Miiverse (post)
      31      "Child Online Privacy Protection" (see CFG:IsCoppacsSupported)

3DS Files - Title IDs

3DS Partition Files/Folders

      3ds:\__journal.nn_                       file?
      3ds:\data\<ID0>\extdata\00048000\..      savedata files  ;\note: <ID0> comes
      3ds:\data\<ID0>\sysdata\..               savedata files  ;/from movable.sed
      3ds:\dbs\certs.db                        database?
      3ds:\dbs\import.db                       database?
      3ds:\dbs\ticket.db                       database? (insane 37Mbyte file???)
      3ds:\dbs\title.db                        database?
      3ds:\dbs\tmp_i.db                        database?
      3ds:\dbs\tmp_t.db                        database?
      3ds:\fixdata\sysdata\                    empty folder
      3ds:\private\movable.sed                 file?
      3ds:\ro\private\                         empty folder
      3ds:\ro\shared\                          empty folder
      3ds:\ro\sys\HWCAL0.dat                   hardware calibration data
      3ds:\ro\sys\HWCAL1.dat                   hardware calibration data copy
      3ds:\rw\shared\                          empty folder
      3ds:\rw\sys\lgy.log                      log file for DSi ErrDisp?
      3ds:\rw\sys\LocalFriendCodeSeed_B        seed file?
      3ds:\rw\sys\native.log (if any)          log file for 3DS ErrDisp?
      3ds:\rw\sys\rand_seed                    seed file?
      3ds:\rw\sys\SecureInfo_A                 Region and Serial/Barcode
      3ds:\rw\sys\updater.log                  log file?
      3ds:\ticket\                             empty folder
      3ds:\title\00040010\..                   System Applications
      3ds:\title\0004001b\..                   System Data Archives 1
      3ds:\title\00040030\..                   System Applets
      3ds:\title\0004009b\..                   Shared Data Archives
      3ds:\title\000400db\..                   System Data Archives 2
      3ds:\title\00040130\..                   System Modules
      3ds:\title\00040138\..                   System Firmware
      3ds:\tmp\title.tik                       temporary file?

DSi 1st Partition Files/Folders on 3DS

      dsi:\import\                             empty folder
      dsi:\shared1\                            empty folder
      dsi:\shared2\0000                        sound recorder data
      dsi:\sys\log\inspect.log                 log file
      dsi:\sys\log\inspect.log~                log file
      dsi:\sys\log\product.log                 log file
      dsi:\sys\log\product.log~                log file
      dsi:\sys\TWLFontTable.dat                font file
      dsi:\ticket\                             empty folder
      dsi:\title\00030005\42383841\..          DS Internet settings for 3DS
      dsi:\title\00030005\484e4441\..          DS Download Play
      dsi:\title\0003000f\484e4841\..          DS Cart Whitelist
      dsi:\title\0003000f\484e4c41\..          DSi Version Data
      dsi:\tmp\                                empty folder

DSi 2nd Partition Files/Folders on 3DS

      photo:\photo\private\ds\app\484E494A\pit.bin   camera info

3ds:\title\00040010\.. System Applications

      00020000 System Settings, mset JPN       ;\
      00021000 System Settings, mset USA       ;
      00022000 System Settings, mset EUR       ; System Settings (mset)
      00026000 System Settings, mset CHN       ; CTR-N-HASx
      00027000 System Settings, mset KOR       ;
      00028000 System Settings, mset TWN       ;/
      00020100 Download Play, dlplay JPN       ;\
      00021100 Download Play, dlplay USA       ;
      00022100 Download Play, dlplay EUR       ; Download Play (dlplay)
      00026100 Download Play, dlplay CHN       ; CTR-N-HDLx
      00027100 Download Play, dlplay KOR       ;
      00028100 Download Play, dlplay TWN       ;/
      00020200 Activity Log JPN                ;\
      00021200 Activity Log USA                ;
      00022200 Activity Log EUR                ; Activity Log
      00026200 Activity Log CHN                ; CTR-N-HMKx
      00027200 Activity Log KOR                ;
      00028200 Activity Log TWN                ;/
      00020300 Health Safety, safe JPN         ;\
      00021300 Health Safety, safe USA         ;
      00022300 Health Safety, safe EUR         ; Health and Safety Info (safe)
      00026300 Health Safety, safe CHN         ; CTR-N-HACx
      00027300 Health Safety, safe KOR         ;
      00028300 Health Safety, safe TWN         ;
      20020300 Health Safety, safe JPN New3DS  ;
      20021300 Health Safety, safe USA New3DS  ;
      20022300 Health Safety, safe EUR New3DS  ;
      N/A      Health Safety, safe CHN New3DS  ;
      20027300 Health Safety, safe KOR New3DS  ;
      N/A      Health Safety, safe TWN New3DS  ;/
      00020400 Nintendo 3DS Camera, CtrApp JPN ;\
      00021400 Nintendo 3DS Camera, CtrApp USA ;
      00022400 Nintendo 3DS Camera, CtrApp EUR ; Nintendo 3DS Camera (CtrApp)
      00026400 Nintendo 3DS Camera, CtrApp CHN ; CTR-N-HEPx
      00027400 Nintendo 3DS Camera, CtrApp KOR ;
      00028400 Nintendo 3DS Camera, CtrApp TWN ;/
      00020500 Nintendo 3DS Sound, CtrApp JPN  ;\
      00021500 Nintendo 3DS Sound, CtrApp USA  ;
      00022500 Nintendo 3DS Sound, CtrApp EUR  ; Nintendo 3DS Sound (CtrApp)
      00026500 Nintendo 3DS Sound, CtrApp CHN  ; CTR-N-HESx
      00027500 Nintendo 3DS Sound, CtrApp KOR  ;
      00028500 Nintendo 3DS Sound, CtrApp TWN  ;/
      00020700 Mii Maker, EDIT JPN             ;\
      00021700 Mii Maker, EDIT USA             ;
      00022700 Mii Maker, EDIT EUR             ; Mii Maker (EDIT)
      00026700 Mii Maker, EDIT CHN             ; CTR-N-HEDx
      00027700 Mii Maker, EDIT KOR             ;
      00028700 Mii Maker, EDIT TWN             ;/
      00020800 StreetPass Mii Plaza, MEET JPN  ;\
      00021800 StreetPass Mii Plaza, MEET USA  ;
      00022800 StreetPass Mii Plaza, MEET EUR  ; StreetPass Mii Plaza (MEET)
      00026800 StreetPass Mii Plaza, MEET CHN  ; CTR-N-HMEx
      00027800 StreetPass Mii Plaza, MEET KOR  ;
      00028800 StreetPass Mii Plaza, MEET TWN  ;/
      00020900 eShop, tiger JPN                ;\
      00021900 eShop, tiger USA                ;
      00022900 eShop, tiger EUR                ; eShop (tiger)
      N/A      eShop, tiger CHN                ; CTR-N-HGRx
      00027900 eShop, tiger KOR                ;
      00028900 eShop, tiger TWN                ;/
      00020a00 System Transfer, CARDBOARD JPN  ;\
      00021a00 System Transfer, CARDBOARD USA  ;
      00022a00 System Transfer, CARDBOARD EUR  ; System Transfer (CARDBOARD)
      N/A      System Transfer, CARDBOARD CHN  ; CTR-N-HCBx
      00027a00 System Transfer, CARDBOARD KOR  ;
      00028a00 System Transfer, CARDBOARD TWN  ;/
      00020b00 Nintendo Zone, Nintendo JPN     ;\
      00021b00 Nintendo Zone, Nintendo USA     ;
      00022b00 Nintendo Zone, Nintendo EUR     ; Nintendo Zone ("Nintendo")
      N/A      Nintendo Zone, Nintendo CHN     ; CTR-N-HMAx
      N/A      Nintendo Zone, Nintendo KOR     ;
      N/A      Nintendo Zone, Nintendo TWN     ;/
      00020d00 Face Raiders JPN                ;\
      00021d00 Face Raiders USA                ;
      00022d00 Face Raiders EUR                ; Face Raiders
      00026d00 Face Raiders CHN                ; CTR-N-HCHx
      00027d00 Face Raiders KOR                ;
      00028d00 Face Raiders TWN                ;
      20020d00 Face Raiders JPN New3DS         ;
      20021d00 Face Raiders USA New3DS         ;
      20022d00 Face Raiders EUR New3DS         ;
      N/A      Face Raiders CHN New3DS         ;
      20027d00 Face Raiders KOR New3DS         ;
      N/A      Face Raiders TWN New3DS         ;/
      00020e00 AR Games, AR_ACT JPN            ;\
      00021e00 AR Games, AR_ACT USA            ;
      00022e00 AR Games, AR_ACT EUR            ; AR Games (AR_ACT)
      00026e00 AR Games, AR_ACT CHN            ; CTR-N-HARx
      00027e00 AR Games, AR_ACT KOR            ;
      00028e00 AR Games, AR_ACT TWN            ;/
      00020f00 Safe mode SysUpdater, mset JPN  ;\
      00021f00 Safe mode SysUpdater, mset USA  ;
      00022f00 Safe mode SysUpdater, mset EUR  ; Safe mode System Updater (mset)
      00026f00 Safe mode SysUpdater, mset CHN  ; CTR-N-HSHx
      00027f00 Safe mode SysUpdater, mset KOR  ;
      00028f00 Safe mode SysUpdater, mset TWN  ;/
      00023000 Promotional video JPN           ;\
      00024000 Promotional video USA           ;
      00025000 Promotional video EUR           ; Promotional video
      N/A      Promotional video CHN           ; (Variable?)
      N/A      Promotional video KOR           ;
      N/A      Promotional video TWN           ;/
      0002bf00 Network ID Settings, act JPN    ;\
      0002c000 Network ID Settings, act USA    ;
      0002c100 Network ID Settings, act EUR    ; Nintendo Network ID Settings (act)
      N/A      Network ID Settings, act CHN    ; CTR-N-HAFx
      N/A      Network ID Settings, act KOR    ;
      N/A      Network ID Settings, act TWN    ;/
      20023100 New3DS microSD Management, mcopy JPN  ;\
      20024100 New3DS microSD Management, mcopy USA  ; New_3DS-only
      20025100 New3DS microSD Management, mcopy EUR  ; microSD Management ('mcopy')
      N/A      New3DS microSD Management, mcopy CHN  ; CTR-N-HAJx
      N/A      New3DS microSD Management, mcopy KOR  ;
      N/A      New3DS microSD Management, mcopy TWN  ;/
      2002c800 New3DS HOME menu/menu JPN       ;\
      2002cf00 New3DS HOME menu/menu USA       ; New_3DS-only, currently stubbed
      2002d000 New3DS HOME menu/menu EUR       ; "HOME menu/menu"
      N/A      New3DS HOME menu/menu CHN       ; Contains information manual data
      2002d700 New3DS HOME menu/menu KOR       ;
      N/A      New3DS HOME menu/menu TWN       ;/ CTR-P-CTAP
      2002c900 New3DS Friends list/friend JPN  ;\
      2002d100 New3DS Friends list/friend USA  ; New_3DS-only, currently stubbed
      2002d200 New3DS Friends list/friend EUR  ; "Friends list/friend"
      N/A      New3DS Friends list/friend CHN  ; Contains information manual data
      2002d800 New3DS Friends list/friend KOR  ;
      N/A      New3DS Friends list/friend TWN  ;/ CTR-P-CTAP
      2002ca00 New3DS Notifications/newslist JPN ;\
      2002d300 New3DS Notifications/newslist USA ; New_3DS-only, currently stubbed
      2002d400 New3DS Notifications/newslist EUR ; "Notifications/newslist"
      N/A      New3DS Notifications/newslist CHN ; Contains information manual data
      2002d900 New3DS Notifications/newslist KOR ;
      N/A      New3DS Notifications/newslist TWN ;/ CTR-P-CTAP
      2002cb00 New3DS Game notes/cherry JPN    ;\
      2002d500 New3DS Game notes/cherry USA    ; New_3DS-only, currently stubbed
      2002d600 New3DS Game notes/cherry EUR    ; "Game notes/cherry"
      N/A      New3DS Game notes/cherry CHN    ; Contains information manual data
      2002da00 New3DS Game notes/cherry KOR    ;
      N/A      New3DS Game notes/cherry TWN    ;/ CTR-P-CTAP

3ds:\title\0004001b System Data Archives 1

      00010002 ClCertA, Client Cert/Keys       ;-contains ".der" files
      00010702 NS CFA
      00010802 Dummy (dummy.txt)
      00018002 web-browser data for NNID / networking, etc.
      00018102 web-browser data for Miiverse offline mode, local web
      00018202 web-kit/OSS CROs for Miiverse applet and "act"
      00019002 Fangate_updater

3ds:\title\00040030 System Applets

      00008102 Test Menu, Demo1 ALL                 ;-CTR-P-CTAP
      00008202 Home Menu, menu JPN                  ;\
      00008f02 Home Menu, menu USA                  ;
      00009802 Home Menu, menu EUR                  ; Home Menu (menu)
      0000a102 Home Menu, menu CHN                  ; CTR-P-HMMx
      0000a902 Home Menu, menu KOR                  ;
      0000b102 Home Menu, menu TWN                  ;/
      00008402 Camera applet JPN                    ;\
      00009002 Camera applet USA                    ; Camera applet (CtrApp)
      00009902 Camera applet EUR                    ; used by Home-menu
      0000a202 Camera applet CHN                    ; CTR-N-HCSx
      0000aa02 Camera applet KOR                    ;
      0000b202 Camera applet TWN                    ;/
      00008502  JPN                                 ;\
      00009102  USA                                 ;
      00009a02  EUR                                 ; whatever
      ?         CHN                                 ; not available on CDN
      ?         KOR                                 ;
      ?         TWN                                 ;/
      00008602 Instruction Manual JPN               ;\
      00009202 Instruction Manual USA               ;
      00009b02 Instruction Manual EUR               ; Instruction Manual viewer
      0000a402 Instruction Manual CHN               ; CTR-N-HMVx
      0000ac02 Instruction Manual KOR               ;
      0000b402 Instruction Manual TWN               ;/
      00008702 Game Notes, Cherry JPN               ;\
      00009302 Game Notes, Cherry USA               ;
      00009c02 Game Notes, Cherry EUR               ; Game Notes (Cherry)
      0000a502 Game Notes, Cherry CHN               ; CTR-N-HGMx
      0000ad02 Game Notes, Cherry KOR               ;
      0000b502 Game Notes, Cherry TWN               ;/
      00008802 Internet Browser, spider JPN         ;\
      00009402 Internet Browser, spider USA         ;
      00009d02 Internet Browser, spider EUR         ; Internet Browser (spider)
      0000a602 Internet Browser, spider CHN         ;
      0000ae02 Internet Browser, spider KOR         ;
      0000b602 Internet Browser, spider TWN         ;/
      20008802 Internet Browser, SKATER JPN New3DS  ;\
      20009402 Internet Browser, SKATER USA New3DS  ; New 3DS
      20009d02 Internet Browser, SKATER EUR New3DS  ; Internet Browser (SKATER)
      ?        Internet Browser, SKATER CHN New3DS  ; CTR-N-HBRx
      2000ae02 Internet Browser, SKATER KOR New3DS  ;
      N/A      Internet Browser, SKATER TWN New3DS  ;/
      00008a02 ErrDisp ALL                          ;\Fatal error viewer, ErrDisp
      00008a03 ErrDisp ALL Safe mode                ;/
      20008a03 ErrDisp JPN Safe mode New3DS         ;\
      20008a03 ErrDisp USA Safe mode New3DS         ;
      20008a03 ErrDisp EUR Safe mode New3DS         ; ErrDisp Safe mode New3DS
      ?        ErrDisp CHN Safe mode New3DS         ;
      20008a03 ErrDisp KOR Safe mode New3DS         ;
      N/A      ErrDisp TWN Safe mode New3DS         ;/
      00008d02 Friend List, friend JPN              ;\
      00009602 Friend List, friend USA              ;
      00009f02 Friend List, friend EUR              ; Friend List (friend)
      0000a702 Friend List, friend CHN              ; CTR-N-HFRx
      0000af02 Friend List, friend KOR              ;
      0000b702 Friend List, friend TWN              ;/
      00008e02 Notifications, newslist JPN          ;\
      00009702 Notifications, newslist USA          ;
      0000a002 Notifications, newslist EUR          ; Notifications (newslist)
      0000a802 Notifications, newslist CHN          ; CTR-N-HCRx
      0000b002 Notifications, newslist KOR          ;
      0000b802 Notifications, newslist TWN          ;/
      0000c002 Keyboard, swkbd JPN                  ;\
      0000c802 Keyboard, swkbd USA                  ;
      0000d002 Keyboard, swkbd EUR                  ; Software Keyboard (swkbd)
      0000d802 Keyboard, swkbd CHN                  ; CTR-N-HKYx
      0000de02 Keyboard, swkbd KOR                  ;
      0000e402 Keyboard, swkbd TWN                  ;
      0000c003 Keyboard, swkbd JPN Safe mode        ;
      0000c803 Keyboard, swkbd USA Safe mode        ;
      0000d003 Keyboard, swkbd EUR Safe mode        ;
      0000d803 Keyboard, swkbd CHN Safe mode        ;
      0000de03 Keyboard, swkbd KOR Safe mode        ;
      0000e403 Keyboard, swkbd TWN Safe mode        ;
      2000c003 Keyboard, swkbd JPN Safe mode New3DS ;
      2000c803 Keyboard, swkbd USA Safe mode New3DS ;
      2000d003 Keyboard, swkbd EUR Safe mode New3DS ;
      ?        Keyboard, swkbd CHN Safe mode New3DS ;
      2000de03 Keyboard, swkbd KOR Safe mode New3DS ;
      N/A      Keyboard, swkbd TWN Safe mode New3DS ;/
      0000c102 Mii picker, appletEd JPN             ;\
      0000c902 Mii picker, appletEd USA             ;
      0000d102 Mii picker, appletEd EUR             ; Mii picker (appletEd)
      0000d902 Mii picker, appletEd CHN             ; CTR-N-HMSx
      0000df02 Mii picker, appletEd KOR             ;
      0000e502 Mii picker, appletEd TWN             ;/
      0000c302 Picture picker, PNOTE_AP JPN         ;\
      0000cb02 Picture picker, PNOTE_AP USA         ;
      0000d302 Picture picker, PNOTE_AP EUR         ; Picture picker (PNOTE_AP)
      0000db02 Picture picker, PNOTE_AP CHN         ; CTR-N-HCCx
      0000e102 Picture picker, PNOTE_AP KOR         ;
      0000e702 Picture picker, PNOTE_AP TWN         ;/
      0000c402 Voice memo picker, SNOTE_AP JPN      ;\
      0000cc02 Voice memo picker, SNOTE_AP USA      ;
      0000d402 Voice memo picker, SNOTE_AP EUR      ; Voice memo picker (SNOTE_AP)
      0000dc02 Voice memo picker, SNOTE_AP CHN      ; CTR-N-HMCx
      0000e202 Voice memo picker, SNOTE_AP KOR      ;
      0000e802 Voice memo picker, SNOTE_AP TWN      ;/
      0000c502 error display JPN-USA-EUR            ;\
      0000cf02 error display CHN-KOR-TWN            ;
      0000c503 error display JPN-USA-EUR Safe mode  ; Non-critical error display
      0000cf03 error display CHN-KOR-TWN Safe mode  ; (error) (online, etc)
      2000c503 error display JPN New3DS Safe mode   ; CTR-N-HEEx
      2000c503 error display USA New3DS Safe mode   ;
      2000c503 error display EUR New3DS Safe mode   ;
      ?        error display CHN New3DS Safe mode   ;
      2000cf03 error display KOR New3DS Safe mode   ;
      N/A      error display TWN New3DS Safe mode   ;/
      0000cd02 extrapad JPN-USA-EUR                 ;\Circle Pad Pro (extrapad)
      0000d502 extrapad CHN-KOR-TWN                 ;/CTR-N-HADx test/calibration
      0000c602 eShop applet JPN                     ;\eShop applet (mint), used by
      0000ce02 eShop applet USA                     ; applications for accessing
      0000d602 eShop applet EUR                     ; the eShop, for DLC/etc.
      N/A      eShop applet CHN                     ; Also used by the eShop
      0000e302 eShop applet KOR                     ; application itself
      0000e902 eShop applet TWN                     ;/CTR-N-HAAx
      0000bc02 Miiverse, olv JPN                    ;\
      0000bd02 Miiverse, olv USA                    ;
      0000be02 Miiverse, olv EUR                    ; Miiverse (olv)
      ?        Miiverse, olv CHN                    ; CTR-N-HAEx
      N/A      Miiverse, olv KOR                    ;
      ?        Miiverse, olv TWN                    ;/
      0000f602 Miiverse, memolib or so JPN-USA-EUR  ;\Likely the "system library"
      ?        Miiverse, memolib or so  CHN         ; for Miiverse (memolib)
      N/A      Miiverse, memolib or so  KOR         ; CTR-N-HAGA
      ?        Miiverse, memolib or so  TWN         ;/
      00008302 Miiverse-posting applet, solv3 JPN   ;\
      00008b02 Miiverse-posting applet, solv3 USA   ; In-app Miiverse-posting
      0000ba02 Miiverse-posting applet, solv3 EUR   ; applet (solv3)
      ?        Miiverse-posting applet, solv3 CHN   ; CTR-N-HAHx
      N/A      Miiverse-posting applet, solv3 KOR   ;
      ?        Miiverse-posting applet, solv3 TWN   ;/
      00009502 Cabinet, amiibo Settings JPN         ;\
      00009e02 Cabinet, amiibo Settings USA         ;
      0000b902 Cabinet, amiibo Settings EUR         ; Cabinet (amiibo Settings)
      ?        Cabinet, amiibo Settings CHN         ; CTR-N-HA3x
      00008c02 Cabinet, amiibo Settings KOR         ;
      0000bf02 Cabinet, amiibo Settings TWN         ;/

3ds:\title\0004009b Shared Data Archives

      00010202 Probably Mii-related                 ;-RomFS contains "CFL_Res.dat"
      00010402 Region Manifest aka area             ;-Mounted as "area:"
      00010602 Non-Nintendo TLS Root-CA Certificates;-RomFS contains ".der" files
      00011002 Dictionary CHN-CH      CHN           ;\
      00011102 Dictionary TWN-TW      TWN           ;
      00011202 Dictionary NL-NL       EUR           ;
      00011302 Dictionary EN-GB       EUR           ;
      00011402 Dictionary EN-US       USA           ;
      00011502 Dictionary FR-FR       EUR           ; Dictionary
      00011602 Dictionary FR-CA       USA           ;
      00011702 Dictionary DE-regular  EUR           ;
      00011802 Dictionary IT-IT       EUR           ;
      00011902 Dictionary JA-small-32 JPN           ;
      00011a02 Dictionary KO-KO       KOR           ;
      00011b02 Dictionary PT-PT       EUR           ;
      00011c02 Dictionary RU-regular  EUR           ;
      00011d02 Dictionary ES-ES       EUR+USA       ;
      00011e02 Dictionary PT-BR       USA           ;/
      00012202 Error Strings JPN                    ;\
      00012302 Error Strings USA                    ;
      00012102 Error Strings EUR                    ; Error Strings
      00012402 Error Strings CHN                    ;
      00012502 Error Strings KOR                    ;
      00012602 Error Strings TWN                    ;/
      00013202 Eula JPN                             ;\
      00013302 Eula USA                             ; End User blurp
      00013102 Eula EUR                             ;
      00013502 Eula CHN                             ;/
      00014002 System Font JPN-EUR-USA              ;\
      00014102 System Font CHN                      ; System Font
      00014202 System Font KOR                      ;
      00014302 System Font TWN                      ;/
      00015202 Rate or so JPN                       ;\
      00015302 Rate or so USA                       ; whatever rate
      00015102 Rate or so EUR                       ; (several CLIM files, probably
      N/A      Rate or so CHN                       ; age rating logos per country)
      00015502 Rate or so KOR                       ;
      0015602  Rate or so TWN                       ;/   ;<-- only 7 letter???

3ds:\title\000400db System Data Archives 2

      00010302 NGWord bad word list                 ;-
      00010502 Nintendo Zone hotspot list           ;-
      00016102 NVer JPN                             ;\
      00016202 NVer USA                             ;
      00016302 NVer EUR                             ; NVer ?
      00016402 NVer CHN                             ;
      00016502 NVer KOR                             ;
      00016602 NVer TWN                             ;
      20016102 NVer JPN New3DS                      ;
      20016202 NVer USA New3DS                      ;
      20016302 NVer EUR New3DS                      ;
      N/A      NVer CHN New3DS                      ;
      20016502 NVer KOR New3DS                      ;
      N/A      NVer TWN New3DS                      ;/
      00017102 CVer JPN                             ;\
      00017202 CVer USA  ;<-- also in JPN carts?    ;
      00017302 CVer EUR                             ; CVer ?
      00017402 CVer CHN                             ;
      00017502 CVer KOR                             ;
      00017602 CVer TWN                             ;/

3ds:\title\00040130 System Modules

      00001002 sm               ;(Stored in NATIVE_FIRM)
      00001003 sm Safe mode     ;(Stored in NATIVE_FIRM Safe mode)
      00001102 fs               ;(Stored in NATIVE_FIRM)
      00001103 fs Safe mode     ;(Stored in NATIVE_FIRM Safe mode)
      00001202 pm               ;(Stored in NATIVE_FIRM)
      00001203 pm Safe mode     ;(Stored in NATIVE_FIRM Safe mode)
      00001302 loader           ;(Stored in NATIVE_FIRM)
      00001303 loader Safe mode ;(Stored in NATIVE_FIRM Safe mode)
      00001402 pxi              ;(Stored in NATIVE_FIRM)
      00001403 pxi Safe mode    ;(Stored in NATIVE_FIRM Safe mode)
      00001502 Application Manager, AM
      00001503 Application Manager, AM Safe mode
      20001503 Application Manager, AM Safe mode New3DS
      00001602 Camera
      20001602 Camera New3DS
      00001702 Config, cfg
      00001703 Config, cfg Safe mode
      20001703 Config, cfg Safe mode New3DS
      00001802 Codec
      00001803 Codec Safe mode
      20001803 Codec Safe mode New3DS
      00001a02 DSP
      00001a03 DSP Safe mode
      20001a03 DSP Safe mode New3DS
      00001b02 GPIO
      00001b03 GPIO Safe mode
      20001b03 GPIO Safe mode New3DS
      00001c02 GSP          ;something GPU related?
      20001c02 GSP New3DS
      00001c03 GSP Safe mode
      20001c03 GSP Safe mode New3DS
      00001d02 Human Interface Devices HID
      00001d03 Human Interface Devices HID Safe mode
      20001d03 Human Interface Devices HID Safe mode New3DS
      00001e02 i2c
      20001e02 i2c New3DS
      00001e03 i2c Safe mode
      20001e03 i2c Safe mode New3DS
      00001f02 MCU
      20001f02 MCU New3DS
      00001f03 MCU Safe mode
      20001f03 MCU Safe mode New3DS
      00002002 Microphone MIC
      00002102 PDN
      00002103 PDN Safe mode
      20002103 PDN Safe mode New3DS
      00002202 Play time PTM (pedometer, battery manager)
      20002202 Play time PTM New3DS (pedometer, battery manager)
      00002203 Play time PTM Safe mode
      20002203 Play time PTM Safe mode New3DS
      00002302 spi
      20002302 spi New3DS
      00002303 spi Safe mode
      20002303 spi Safe mode New3DS
      00002402 Network manager, AC
      00002403 Network manager, AC Safe mode
      20002403 Network manager, AC Safe mode New3DS
      00002602 Cecd (StreetPass)
      00002702 CSND
      00002703 CSND Safe mode
      20002703 CSND Safe mode New3DS
      00002802 Download Play, DLP
      00002902 HTTP
      00002903 HTTP Safe mode
      20002903 HTTP Safe mode New3DS
      00002a02 MP
      00002a03 MP Safe mode
      00002b02 NDM
      00002c02 NIM
      00002c03 NIM Safe mode
      20002c03 NIM Safe mode New3DS
      00002d02 Low-level wifi manager, NWM
      00002d03 Low-level wifi manager, NWM Safe mode
      20002d03 Low-level wifi manager, NWM Safe mode New3DS
      00002e02 Sockets
      00002e03 Sockets Safe mode
      20002e03 Sockets Safe mode New3DS
      00002f02 SSL
      00002f03 SSL Safe mode
      20002f03 SSL Safe mode New3DS
      00003000 Process9  ;Stored in ARM9 section of NATIVE_FIRM and Safe Mode FIRM
      00003102 Process Manager, PS
      00003103 Process Manager, PS Safe mode
      20003103 Process Manager, PS Safe mode New3DS
      00003202 friends (Friends list)
      00003203 friends (Friends list) Safe mode
      20003203 friends (Friends list) Safe mode New3DS
      00003302 Infrared, IR
      00003303 Infrared, IR Safe mode
      20003303 Infrared, IR Safe mode New3DS
      00003402 BOSS (SpotPass)
      00003502 News (Notifications)
      00003702 RO
      00003802 act (handles Nintendo Network accounts)
      00004002 nfc Old3DS
      20004002 nfc New3DS
      20004102 mvd New3DS
      20004202 qtm New3DS
      00008002 NS (Memory-region: "SYSTEM")
      00008003 NS (Memory-region: "SYSTEM") Safe mode
      20008003 NS (Memory-region: "SYSTEM") Safe mode New3DS

3ds:\title\00040138 System Firmware

      00000001 DevUnit SafeUpdater or so    ;DevUnit, similar to Safe mode_FIRM
      00000002 Native Firmware Old3DS       ;NATIVE_FIRM         (Native Firmware)
      20000002 Native Firmware New3DS       ;NATIVE_FIRM New_3DS (Native Firmware)
      00000003 Safe Mode Old3DS             ;Safe mode_FIRM
      20000003 Safe Mode New3DS             ;Safe mode_FIRM New_3DS
      00000102 TWL DSi Firmware Old3DS      ;TWL_FIRM         (DSi Firmware)
      20000102 TWL DSi Firmware New3DS      ;TWL_FIRM New_3DS (DSi Firmware)
      00000202 AGB GBA Firmware Old3DS      ;AGB_FIRM         (GBA Firmware)
      20000202 AGB GBA Firmware New3DS      ;AGB_FIRM New_3DS (GBA Firmware)

3ds:\title\00040000 Factory Test

      00056c00 Flipnote Studio 3D JPN                   ;\tickets exist on New3DS
      000eca00 3D demo video (paperplanes/butterflies)  ;/
      0f980000 CTRAging ("Test Program") (uh, or reportedly uppercase 0F980000 ?)

3ds:\title\00040001 Download Play Titles and Old3DS Factory OS
Normally, 00040001 is for Download Play Titles. Additionally, Old3DS has Factory stuff in 00040001 (New3DS has the Factory OS in the "normal" locations, ie. FIRM in 00040138, Applets in 00040030, and Modules in 00040130).
3ds:\title\0004000e Patches/Updates?
Whatever, patches/updates for titles in 3ds:\title\00040000 or so?
3ds:\data\<ID0>\extdata\00048000:

      e0000000 System transfer (request transfer if file is present)
      f0000001 Camera application NAND JPEG/MPO files, phtcache.bin, UploadData.dat
      f0000002 Sound application NAND M4A files
      f0000009 SpotPass content storage for notifications
      f000000b Miis and Play/Usage Records
      f000000c Contains bashotorya.dat and bashotorya2.dat
      f000000d Home Menu SpotPass content data storage
      f000000e Update notification versionlist.dat (added in 7.0.0-13)

3ds:\data\<ID0>\sysdata:

     System Module Savegames (0001xxxx)...
      0001000f reportedly SEEDDB or so
      00010011 FS module savedata  ;used for Anti Savegame Restore
      00010015 AM module savedata
      00010017 Config savegame      ;aka System Settings (user name, etc.)
      00010022 PTM savegame
      00010026 CECD savegame
      0001002c NIM savegame
      00010032 Friends module savegame
      00010034 BOSS module savegame
      00010035 News module savegame
      00010038 Act module savegame
      00010040 NFC module savegame
     System application and applet savegames (0002xxxx)...
      00020082 Home Menu savegame JPN
      0002008f Home Menu savegame USA
      00020098 Home Menu savegame EUR
      00020086 Instruction Manual applet savegame JPN
      00020092 Instruction Manual applet savegame USA
      0002009b Instruction Manual applet savegame EUR
      00020087 Game Notes applet savegame JPN
      00020093 Game Notes applet savegame USA
      0002009c Game Notes applet savegame EUR
      00020088 Old3DS/New3DS Internet Browser savegame JPN
      00020094 Old3DS/New3DS Internet Browser savegame USA
      0002009d Old3DS/New3DS Internet Browser savegame EUR
      0002008d Friend List applet savegame JPN
      00020096 Friend List applet savegame USA
      0002009f Friend List applet savegame EUR
      000200bb Additional savedata t.bin history for the New3DS Browser (ALL)
      000200bc olv applet savegame, Miiverse JPN
      000200bd olv applet savegame, Miiverse USA
      000200be olv applet savegame, Miiverse EUR
      000200c5 error applet savegame (ALL)
      000200c6 mint applet savegame (ALL)
      00020200 System Settings savegame JPN  ;\whatever, contains Mset.data
      00020210 System Settings savegame USA  ; and MsetForBoss.dat
      00020220 System Settings savegame EUR  ;/
      00020202 Activity Log application savegame JPN
      00020212 Activity Log application savegame USA
      00020222 Activity Log application savegame EUR
      00020204 Nintendo 3DS Camera application savegame JPN
      00020214 Nintendo 3DS Camera application savegame USA
      00020224 Nintendo 3DS Camera application savegame EUR
      00020205 Nintendo 3DS Sound application savegame JPN
      00020215 Nintendo 3DS Sound application savegame USA
      00020225 Nintendo 3DS Sound application savegame EUR
      00020207 Mii Maker application savegame JPN
      00020217 Mii Maker application savegame USA
      00020227 Mii Maker application savegame EUR
      00020208 StreetPass Mii Plaza application savegame JPN
      00020218 StreetPass Mii Plaza application savegame USA
      00020228 StreetPass Mii Plaza application savegame EUR
      00020209 eShop application savegame JPN
      00020219 eShop application savegame USA
      00020229 eShop application savegame EUR
      0002020a System Transfer savegame JPN
      0002021a System Transfer savegame USA
      0002022a System Transfer savegame EUR
      0002020b Nintendo Zone savegame JPN
      0002021b Nintendo Zone savegame USA
      0002022b Nintendo Zone savegame EUR
      0002020d Face Raiders savegame JPN
      0002021d Face Raiders savegame USA
      0002022d Face Raiders savegame EUR
      0002020e AR Games savegame JPN
      0002021e AR Games savegame USA
      0002022e AR Games savegame EUR
      000202bf act (NNID settings) application savegame JPN
      000202c0 act (NNID settings) application savegame USA
      000202c1 act (NNID settings) application savegame EUR
      00020231 microSD Management application savegame JPN
      00020241 microSD Management application savegame USA
      00020251 microSD Management application savegame EUR

3DS Files - Title NS

System Data Archives NS (titleID=0004001B00010702) contains 2-4 files:

      RomFS:\key.bin
      RomFS:\value.bin
      RomFS:\ctr_backup_black_list  ;v6.0.0 and up
      RomFS:\qtm_black_list         ;v8.1.0 and up, New3DS only

Most of these files seem to contain 20bit Title IDs, merged with flags in upper bits. The 20bit IDs are taken from bit8-27 of the full 64bit Title ID:

      64bit: "0004xxxxxtttttxx"  -->  20bit: "ttttt"

A list with 64bit 3DS Title IDs can be found at http://www.3dsdb.com/
key.bin
Unknown purpose, used when launching applications, contains several entries with flags and 20bit title IDs for Ridge Racer and Zelda Ocarina of Time (for several regions each).

      000h N*4  Entries (00Xttttth)

Original filesize was 12 bytes, changed to 48 bytes in v6.0.0, and changed to 32 bytes in later New3DS versions (and also changed the flag bits in bit20-23). The separate entries are:

      12-byte    48-byte    32-byte    ;Title
      -          00000000h  -          ;Garbage?
      -          00400000h  -          ;Garbage?
      -          00800000h  -          ;Garbage?
      -          00800000h  -          ;Garbage?
      00200328h  00E00328h  00200328h  ;Ridge Racer 3D (JPN)
      -          00000334h  00400334h  ;Zelda Ocarina of Time 3D (JPN)
      -          00000335h  00400335h  ;Zelda Ocarina of Time 3D (USA)
      -          00000336h  00400336h  ;Zelda Ocarina of Time 3D (EUR)
      0020033Bh  00E0033Bh  0020033Bh  ;Ridge Racer 3D (EUR)
      00200358h  00E00358h  00200358h  ;Ridge Racer 3D (USA)
      -          000008F8h  004008F8h  ;Zelda Ocarina of Time 3D (KOR)
      -          000008F9h  004008F9h  ;Zelda Ocarina of Time 3D (CHN)

value.bin

      000h N*8  Entries (00000000xxxxxxxxh)

Original filesize was 8 bytes, changed to 32 bytes in v6.0.0, and changed to 16 bytes in later New3DS versions.

     8-bytes on Old3DS:
      000h 8    Unknown, 0000000047E00001h
     32-bytes on Old3DS:
      000h 8    Unknown, 0000000000000002h
      008h 8    Unknown, 00000000002001CAh
      010h 8    Unknown, 0000000000000000h
      018h 8    Unknown, 0000000047E00001h
     16-bytes on New3DS:
      000h 8    Unknown, 0000000047E00001h
      008h 8    Unknown, 0000000000000002h

This is used when launching applications.
ctr_backup_black_list (v6.0.0 and up)
Blacklist with 20bit Title IDs for SD Savedata Backups.

      000h 4    Number of entries (5Dh in v6.0.0, or 61h in later versions)
      004h 0Ch  Zero
      010h N*4  Entries (001ttttth, with ttttt=00321h..0107Ch)

qtm_black_list (v8.1.0 and up, New3DS only)
Might be a list of 20bit Title IDs for disabling QTM (New3DS head-tracking)?

      000h 4    Number of entries? (04h)
      004h 0Ch  Zero
      010h N*4  Entries (001F8087h, 004F8088h, 006F8089h, 010F8090h)

The 20bit values in range F8000h-FEFFFh are reportedly used for "Evaluation" or "Factory" titles, rather than retail titles?

3DS Files - Savedata Extdata

Extdata files in FAT filesystem:

      ..\00000000\00000001    ;-DIFF:VSXE directory
      ..\00000000\00000002    ;-DIFF:raw_data (usually 1-byte icon?)
      ..\00000000\00000003    ;\
      ..\00000000\00000004    ; DIFF:raw_data (usually user/boss files, if any)
      ..\00000000\ (etc.)     ;/
      ..\Quota.dat            ;-DIFF:raw_data (QUOT, whatever)

Example content of the above DIFF:VSXE filesystem:

      icon                ;with 64bit VSXE.ID same as DIFI.ID of 00000000\00000002
      boss\               ;usually empty folder (used in SpotPass data)
      user\somefile.dat   ;with 64bit VSXE.ID same as DIFI.ID of 00000000\000000xx
      user\otherfile.bin  ;with 64bit VSXE.ID same as DIFI.ID of 00000000\000000xx

"This page describes the format and encryption of extdata, "extra data" stored on SD card and NAND, at":

      3ds:\data\<ID0>\extdata\00048000\
      sd:\Nintendo 3DS\<ID0>\<ID1>\extdata\00000000\

"Extdata ID High is always 00000000 for SD, and always 00048000 for eMMC. Regular apps can only mount SD extdata using the same Extdata ID which is stored in the CXI exheader. Therefore, regular apps which have the exheader Extdata ID set to zero can't use extdata. This restriction doesn't apply for shared extdata with Extdata ID high "bitmask"(=?) 48000h stored on NAND. System apps with a certain(=?) access right can mount arbitrary extdata. All NAND extdata is shared extdata, while all SD extdata is normal extdata."
Quota.dat File (DIFF container with 48h-byte raw data)

      000h 4       ID "QUOT"
      004h 4       Version (00030000h)
      008h 4       Always 1000h, maybe DIFF/VSXE cluster/block size?
      00Ch 4       Always 7Eh, maybe \00000000\ directory capacity?
      010h 4       Zero
      014h 4       Unknown (eg. 4000h, 134h, 8D9h, or 2A8h, or C8h) ;maybe max size
      018h 4       Zero
      01Ch 4       Unknown (eg. 3FC0h, 123h, 121h, or 0EEh, or B0h) ;maybe max-xx
      020h 4       Zero
      024h 4       Zero
      028h 4       Unknown (eg. 3FD7h, 128h, 128h, or 17Dh, or B0h) ;maybe max-x
      02Ch 4       Zero
      030h 4       Most recent "00000000\000000xx" file number? (2 and up)
      034h 4       Zero
      038h 4       Zero
      03Ch 4       Zero
      040h 4       Most recent "00000000\000000xx" file size? (or 0=deleted?)
      044h 4       Zero

Quota.dat exists for eMMC shared extdata only (not for SD extdata). The purpose of the Quota.dat file is unknown (it might be some kind of log file, and/or containing some settings/limits or so).
VSXE File System
The extdata\00048000\f00000xx\00000000/00000001 files contain a VSXE filesystem (inside of the DIFF container).
3DS Files - Savedata SAVE/BDRI/VSXE Formats
The VSXE format does have file & directory names, but without actually assigning data clusters to files (instead, VSXE does merely assign ID values to each "file" - and that ID refers to the DIFF[154h] ID in one of the extdata\00048000\f00000xx\00000000/000000xx files).
Virtual File System Structure
When extdata is created, these are always created regardless of whether the title actually uses them.

      /icon  This virtual file contains the extdata icon displayed in data
               management. This icon can only be written to by titles when
               creating extdata, titles would have to recreate extdata to
               change the icon. This file can't be read directly, instead it
               is read via FS:ReadExtSaveDataIcon.
      /user/ This virtual directory contains the title's actual extdata files.
      /boss/ This virtual directory can contain SpotPass content. SpotPass
               content can only be downloaded to this /boss virtual directory.

User extdata and SpotPass extdata use separate mount points at /user and /boss. Therefore one mount can't access the other virtual directory, and also can't access /icon (the title's SpotPass extdata can be mounted by the title itself, if it uses SpotPass).
Extended Banner (optional)
Folder "\user\ExBanner\" can contain optional extended banner files:

      \user\ExBanner\COMMON.bin     ;-common data for all regions
      \user\ExBanner\JPN_JP.bin     ;\
      \user\ExBanner\USA_EN.bin     ; per region/language
      etc.                          ;/

If present, this banner is displayed instead of the CXI ExeFS banner.
Uh, displayed instead of? Or does it merely replace textures?
3DS Files - Video Banner (Extended Banner)
SD Extdata ID's

      JPN      USA      EUR       Description     Extdata images
      00000082 0000008f 00000098  Home Menu extdata, this contains home-menu
                                    savedata and cached icons for applications.
      00000200 00000210 00000220  System Settings extdata added with 2.0.0-2.
      00000207 00000217 00000227  Mii Maker, contains an ExBanner      cleartext
      00000208 00000218 00000228  Streetpass Mii Plaza                 11 mb big!
      00000209 00000219 00000229  eShop, contains store music in AAC format.
      0000020b 0000021b 0000022b  Nintendo Zone
      0000020d 0000021d 0000022d  Face Raiders, likely contains an ExBanner
      000002cc 000002cd 000002ce  Home Menu theme
      ?        000004aa 000004ab  Nintendo Video Extra Data

This is where the video files are stored, and includes the thumbnail, the description, and possibly some checksum info in each video file stored in the extdata images. There are always 9 files within the subdirectory "00000000" of this folder, even without any videos downloaded. The files are "00000001" - "00000009", and "00000003" - "00000008" have the same filesize of 50.7 MB. It is possible to restore the older videos by overwriting all the files within this directory. Provided of course you have made a backup of the files before hand, by copying all the files within this directory to your computer. As far I'm aware its not possible to mix and match the files in order to get certain videos in one grouping, ie. having all 3 Zelda orchestral recordings in one group of 4 Nintendo videos.

      00000306 00000308 00000307  Mario Kart 7
      0000030b 0000030d 0000030c  Nintendogs + Cats
      00000326 00000326 00000326  Pok‚dex 3D
      00000305 0000032d 0000033c  Super Street Fighter IV 3D
      00000328 00000358 0000033b  Ridge Racer 3D
      ?        0000034d 00000402  Samurai Warriors Chronicles
      ?        0000034f 0000038a  Dead or Alive Dimensions
      00000481 N/A      N/A       Monster Hunter Tri G (Download-Quests)
      ?        00000517 00000518  Swapnote
      0000055d 0000055d 0000055d  P-Letter X, P-Letter Y
      ?        00000725 00000724  Ambassador Certificate
      ?        ?        000007af  New Super Mario Bros. 2
      ?        00000863 00000864  Animal Crossing: New Leaf
      ?        00000a85 00000a86  Professor Layton and the Miracle Mask
      ?        ?        00000a87  Professor Layton and the Azran Legacy (German)
      ?        ?        00000b4f  Fullblox / Crashmo
      ?        ?        00000ba9  Pok‚mon Mystery Dungeon: Gates to Infinity
      ?        ?        00000c24  Denpa men
      00000c73 00000c73 00000c73  Save Data Transfer Tool
      ?        ?        00000d9a  Donkey Kong Country Returns 3D: Trailer
      ?        ?        00000ea6  Etrian Odyssey IV
      ?        00000edf 00000ee0  Super Smash Bros. for Nintendo 3DS
      ?        00000f14 00000f1e  Phoenix Wright: Ace Attorney - Dual Destinies
      ?        00001007 00001005  Professor Layton vs Phoenix Wright: Ace Attorney
      ?        ?        00001062  Nintendo Pocket Football Club
      ?        ?        0000111c  Yoshi's New Island
      ?        ?        00001131  Fantasy Life
      000011c5 000011c5 000011c5  Pok‚mon Omega Ruby, Pok‚mon Alpha Sapphire
      ?        ?        000012ca  Mario vs. Donkey Kong: Tipping Stars
      ?        ?        00001499  Korg DSN-12
      ?        ?        000014f2  Animal Crossing: Happy Home Designer
      000014d1 000014d1 000014d1  Home Menu badge
      ?        ?        00001632  Fullblox / Stretchmo
      ?        ?        00001646  Pok‚mon Rumble World
      00001648 00001648 00001648  Pok‚mon Sun, Pok‚mon Moon
      0000165c 0000165c 0000165c  Home Menu saved theme layouts
      ?        ?        00001678  Yo-kai Watch
      ?        ?        000018fa  Phoenix Wright: Ace Attorney - Spirit of Justice
      ?        ?        0000198f  Animal Crossing: New Leaf - Welcome amiibo
      ?        ?        00001a05  Super Mario Maker
      ?        ?        00001a2e  Swapdoodle

eMMC Shared Extdata ID's

      e0000000 Request system transfer (if present)
      f0000001 Camera application NAND JPEG/MPO files, phtcache.bin, UploadData.dat
      f0000002 Sound application NAND M4A files
      f0000009 SpotPass content storage for notifications
      f000000b Miis and Play/Usage Records
                 Contains idb.dat, idbt.dat, gamecoin.dat, ubll.lst, CFL_DB.dat,
                 and CFL_OldDB.dat. These files contain cleartext Miis and some
                 data relating (including cached ICN data) to Play/Usage Records
      f000000c Contains bashotorya.dat and bashotorya2.dat
      f000000d Home Menu SpotPass content data storage
      f000000e Update notification versionlist.dat (added in 7.0.0-13)

Shared Extdata "f000000b" gamecoin.dat

      000h 4  Fixed ID or so (4F00h)
      004h 2  Total Play Coins
      006h 2  Total Play Coins obtained on the date stored below. When the below
                date does not match the current date, this field is reset to zero,
                then the date (and other fields) are updated. Once this value
                is >=10, no more Play Coins can be obtained until the current date
                changes.
      008h 4  Total step count at the time a new Play Coin was obtained.
      00Ch 4  Step count for the day the last Play Coin was obtained, for that
                day's step count (same as the step count displayed by home-menu
                when this file was updated).
      010h 2  Year
      012h 1  Month
      013h 1  Day

The above date stores the last time new Play Coin(s) were obtained. The contents of this file is updated by home-menu. PTM:GetTotalStepCount is not checked constantly, after home-menu boot this is only checked when waking from sleep-mode. Each time home-menu updates the contents of this file, home-menu will set the Play Coin total to 300 if it's higher than the 300 Play Coin limit.
Shared Extdata "f000000b" ubll.lst
List of blocked users.
Empty space is filled with 0Ch-long sequences of 00 00 ... 07
Tools
3ds-save-tool - Extract/verifies extdata

3DS Files - Savedata SAVE/BDRI/VSXE Formats

SAVE/BDRI/VSXE Header

      000h 4   ID "SAVE",00h,00h,04h,00h ;for savegame (file names + data clusters)
               ID "BDRI",00h,00h,03h,00h ;for database (file IDs   + data clusters)
               ID "VSXE",00h,00h,03h,00h ;for extdata  (file names + data IDs)
      008h 8   File System Information offset (SAVE/BDRI=20h or VSXE=138h)
      010h 8   Image size in blocks (eg. 1Eh)
      018h 4   Image block size (usually 1000h) (or 80h or 200h, in databases)
      01Ch 4   Padding
     Extra entries, for VSXE (extdata) only:
      020h 8    Unknown (can be 1)                                            (1)
      028h 4    Most recently mounted Extdata image 'Action'   ;whut?         (0)
      02Ch 4    Unknown                                                       (0)
      030h 4    Most recently mounted Extdata image FAT file  (eg. 3="00000003")
      034h 4    Unknown                                                       (0)
      038h 100h Most recently mounted Extdata image VSXE name (eg. "/user/file",0)
      Note: The Quota.dat file does also seem to log some "most recent" stuff.

File System Information (usually at offset 20h or 138h)

      000h 4   Unknown (0)
      004h 4   Cluster size (usually 1000h) (or 80h or 200h, in databases)
      008h 8   Directory hash table offset (eg. 88h, ie. after SAVE header)
      010h 4   Directory hash table bucket count (eg. 0Bh)
      014h 4   Padding (0) (or 04h in BDRI?)
      018h 8   File hash table offset      (eg. B4h, ie. after above table)
      020h 4   File hash table bucket count (eg. 0Bh)
      024h 4   Padding (0) (or 04h in BDRI?)
      028h 8   File allocation table offset (eg. E0h)
      030h 4   File allocation table entry count (eg. 1Dh = Cluster 0..1Dh)
      034h 4   Padding (0) (or 04h in BDRI?)
     Single Partition (normal case):
      038h 8   Cluster 1 offset                    (usually 1000h)             ;<--
      040h 4   Num clusters                        (eg. 1Dh = Cluster 1..1Dh)
      044h 4   Padding (0)
      048h 4   Directory table first cluster-1     (usually 0, ie. Cluster 1)  ;<--
      04Ch 4   Directory table num clusters        (usually 1)                 ;<--
      050h 4   Max number of subdirectories (0..N) (eg. 0Ah=Dummy+Root+10 Sub's)
      054h 4   Padding (0)
      058h 4   File table first cluster-1          (usually 1, ie. Cluster 2)  ;<--
      05Ch 4   File table num clusters             (usually 01h)               ;<--
      060h 4   Max number of files                 (eg. 0Ah=Dummy+10 Files?)
      064h 4   Padding (0)
     Dual Partition (more tightly packed):
      038h 8   Cluster 1 start               (always 0, start in partition B)  ;<--
      040h 4   Num clusters                        (eg. 1Dh = Cluster 1..1Dh)
      044h 4   Padding (0)
      048h 8   Directory table offset                                          ;<--
      050h 4   Max number of subdirectories (0..N) (eg. 0Ah=Dummy+Root+10 Sub's)
      054h 4   Padding (0)
      058h 8   File table offset                                               ;<--
      060h 4   Max number of files                 (eg. 0Ah=Dummy+10 Files?)
      064h 4   Padding (0)

When partition B doesn't exist, directory & file entry tables are allocated in the data region, and while (uh?) be marked allocated in file allocation table as if they are two normal files.
However, only continuous allocation has been observed, so directly reading block_count * block_size bytes from data_region + starting_block_index * block_size should be safe.
Directory Table

      Entry #0     Dummy Entry    (aka entrypoint for unused (deleted?) entries)
      Entry #1     Root Directory (aka entrypoint for used entries)
      Entry #2..X  Sub-directories (used and deleted entries?)
      Entry #Y..Z  Sub-directories (still unused entries?) (zerofilled)

Directory Entries:

      SAVE VSXE BDRI Siz Content
      000h 000h 000h 4   Directory Index of Parent directory (0=none; in root)
      004h 004h -    16  Directory Name in ASCII, zeropadded (all zero for root)
      014h 014h 004h 4   Directory Index of next sibling directory   (0=none)
      018h 018h 008h 4   Directory Index of first subdirectory       (0=none)
      01Ch 01Ch 00Ch 4   File index of first file in this directory  (0=none)
      020h 020h 010h ..  Padding (0) / zero?
      024h 024h 01Ch 4   Directory Index of next same hash table bucket (0=none)

Dummy Directory entries:

      SAVE VSXE BDRI Siz Content
      000h 000h 000h 4   Current Total entry count (eg. 2 = Dummy+Root)
      004h 004h 004h 4   Maximum entry count = maximum directory count + 2
      008h 008h 008h ..  Padding / All zero
      024h 024h 01Ch 4   Directory Index of next dummy (=deleted?) entry (0=none)

Dummy entries are left there when deleting directories, and reserved for future use.
File Table

      Entry #0     Dummy Entry
      Entry #1..X  File Entries (used and deleted entries?)
      Entry #Y..Z  File Entries (still unused entries?) (zerofilled)

The file entry table is an array of the entry type shown below. It contains information for each file.

      SAVE VSXE BDRI Siz Content
      000h 000h 000h 4   Directory index of Parent Directory
      004h 004h -    16  File Name in ASCII, zeropadded
      -    -    004h 8   Title ID
      014h 014h 00Ch 4   File index of next sibling file (0=none)
      018h 018h 010h 4   Padding
      01Ch -    014h 4   First cluster-1 (0..N-1 = Cluster 1..N, or 80000000h=None)
      020h -    018h 8   File Size
      -    -    020h 4   Padding?
      -    01Ch -    4   Always 80000000h (extdata has no clusters)
      -    020h -    8   Unique identifier. See Extdata
      028h 028h 024h 4   Padding?
      02Ch 02Ch 028h 4   File Index of next file in same hash table bucket (0=none)

Dummy File entries:

      SAVE VSXE BDRI Siz Content
      000h 000h 000h 4   Current total entry count (eg. 2=Dummy+OneFile)
      004h 004h 004h 4   Maximum File entry count = maximum file count + 1
      008h 008h 008h ..  Padding (0)
      02Ch 02Ch 028h 4   File Index of the next dummy (=deleted?) entry (0=last)

Dummy entries are left there when deleting files, and reserved for future use.
File Allocation Table (FAT)
The FAT uses 64bit entries, containing the next & previous cluster number (unlike microsoft FATs, which contain next cluster only).

      0-30  Previous Cluster (1..max, or 0=None)
      31    Blah flag (0=No, 1=First cluster, or Second/Last entry of large block)
      32-62 Next Cluster     (1..max, or 0=None)
      63    Multiple flag    (0=No, 1=First entry of Large block)

The Multiple flag indicates a large block that consists of more than one cluster. The first entry in the large block has Multiple=1, the second and last entry of the large block contain the first/last cluster numbers of the large block.

     For example, a file using cluster 20, 100-120, 50 (in that order):
      File List:     Cluster=19 (aka 20-1)           ;-first cluster of file
      FAT[20]:       Prev=0,   Next=100, Blah=1      ;-cluster 20
      FAT[100]:      Prev=20,  Next=50,  Multiple=1  ;\
      FAT[101]:      Prev=100, Next=120, Blah=1      ; cluster 100..120
      FAT[102..119]: Zero (or garbage?)              ;
      FAT[120]:      Prev=100, Next=120, Blah=1      ;/
      FAT[50]:       Prev=100, Next=0                ;-cluster 50

All free blocks that are not allocated to any files also form a node chain in the allocation table, with starting in FAT[0]:

      FAT[0]:        Prev=0, Next=FirstFree    ;-points to begin of free chain

Directory Hash Table & File Hash Table

      000h 4   File/Directory Index of 1st name with hash=0
      004h 4   File/Directory Index of 1st name with hash=1
      008h 4   File/Directory Index of 1st name with hash=2
      etc.

The hash depends on parent_directory_index and file/directory name as key:

      hash = parent_dir_index XOR 091A2B3Ch ;-parent mangled with digits 0123+9ABC
      hash = (hash ROR 1) XOR name[00h]     ;\
      hash = (hash ROR 1) XOR name[04h]     ; 16-byte file/directory name
      hash = (hash ROR 1) XOR name[08h]     ; (including trailing 00h's)
      hash = (hash ROR 1) XOR name[0Ch]     ;/
      hash = (hash MOD bucket_count)        ;-final value

Uh, but, that cannot be true for BDRI...

      BDRI doesn't have any file names (instead has 8-byte Title IDs)
      BDRI doesn't have any directory names

Layout for duplicate data = true
The DISA container only has one partition which is always configured as external IVFC level 7 disabled (see DISA format for details). All components are stored in this partition as

     Partition A
      SAVE/BDRI/VSXE header
      Directory hash table
      File hash table
      File allocation table (FAT)
      data region
      directory entry table is allocated inside data region  ;Cluster 1
      file entry table as well                               ;Cluster 1+x
      all file data is also allocated here                   ;Cluster 1+x+y
     Partition B
      none such

In this layout, all data is duplicated by DISA's DPFS tree, which is what the parameter duplicate data implies.
Layout for duplicate data = false
The DISA container has two partitions. Partition A is always configured as external IVFC level 7 disabled, and partition B is configured as it enabled. Components are stored among the two partitions as

     Partition A
      SAVE header at the beginning
      Directory hash table
      File hash table
      File allocation table (FAT)
      directory entry table
      file entry table
     Partition B
      used as data region entirely, and only has file data allocated.  ;Cluster 1

In this layout, all file system metadata is duplicated by partition A DPFS tree, but file data is not as partition B has external IVFC level 7.
Initialization
When a save FLASH contains all xFFFF blocks it's assumed uninitialized by the game cartridges and it initializes default data in place, without prompting the user. The FFFFFFFFh blocks are uninitialized data. When creating a non-gamecard savegame and other images/files, it's initially all FFFFFFFFh until it's formatted where some of the blocks are overwritten with encrypted data.
Tools
3dsfuse supports reading and modifying savegames. In the mounted FUSE filesystem, the /output.sav is the raw FLASH save-image. When the save was modified, a separate tool to update the CMAC must be used with /clean.sav, prior to writing output.sav to a gamecard.
3DSExplorer supports reading of savegames, it doesn't support reading the new encrypted savegames and maybe in the future it will support modifying (some of the modyfing code is already implemented).
wwylele's 3ds-save-tool supports extracting files from savegames and extdata. It properly reconstructs data from the DPFS tree and extracts files in directories hierarchy.
3dsfuse-ex similar to 3dsfuse, but supports savegame inner FS, proper DPFS handling, and automatic CMAC update. Still WIP.

3DS Files - Savedata DISA and DIFF

DISA and DIFF are two container formats (usually containing SAVE/BDRI/VSXE filesystems, or raw data in some cases).
The DISA/DIFF containers are storing everything in data pairs that consist of active/inactive halves (somewhat maintaining a backup copy in the active half, whilst allowing to write new data to the inactive half). Additionally, there are SHA256's for all data blocks (for error checking, and for preventing hacks/patches when not having the AES-CMAC key for the master checksum).
Duplicated Data Pairs
One can safely overwrite the inactive halves (whilst other tasks could still read the old intact data, and without risking to destroy the active data if the console crashes during writing), and finally apply the changes by toggling the active half flags.
The disadvantages are that the duplicated data requires twice as much memory, crawling through the 7 levels does hurt read/write access time, writing the 7 levels does reduce the chip lifetime, the DIFI's and DPFS level 1-2 are using the same 200h-byte sector for active/inactive halves (so write errors on that sectors would also destroy the old active data).
The whole concept is either blatant nonsense, or incredibly clever (in case Nintendo should have somehow estimated that the few benefits are outweighting the many disadvanges).
Variants with Duplicated or Non-duplicated Data
1) Single Partition with Internal Level 7 (duplicated data)
2) Single Partition with External Level 7 (non-duplicated data)
3) Dual Partition (one Internal and one External for partially-duplicated data)
4) DIFF:VSXE directory file, with data stored in separate DIFF:data files

            XXX extdata\..\Quota.dat         has external IVFC
            XXX extdata\..\00000000\00000002 has external IVFC

Format
A DISA / DIFF file consists of the following components:

      0000h 200h  Header (DISA or DIFF)
      0200h 130h  1st DIFI+IVFC+DPFS+SHA256 for Partition A
                    (and somewhere DIFI+IVFC+DPFS+SHA256 for Partition B, if any?)
      0330h 130h  2nd DIFI+IVFC+DPFS+SHA256 for Partition A (as above)
      1000h ...   Partition A
      xxxxh ...   Partition B (optional, can only exist for DISA, not for DIFF).

Encryption
DISA and DIFF formats don't have their own encryption specification. They follow the encryption method defined by their media:

      - Gamecard savegames have special wear leveling + encryption layers.
      - Files on SD follow the general SD filesystem encryption rule.
      - Files on NAND are in cleartext, after decrypting the NAND partition.

DISA header (used for Savegame and System savedata)
DIFF header (for Extdata and Title Database)
All offsets in the header are relative to the beginning of the DISA/DIFF file, except for partition descriptor offsets, which are relative to the beginning of the (active) partition table.

      DISA DIFF Siz Content
      000h 000h 10h AES-CMAC on SHA256 on special ID-strings-and-Header[100h..1FFh]
      010h 010h F0h Padding (0)
      100h 100h 8   ID ("DISA",00h,00h,04h,00h or "DIFF",00h,00h,03h,00h)
      108h -    4   Partition count, 1 or 2     (aka "1=A" or "2=A+B")          (1)
      10Ch -    4   Padding
      110h 108h 8   1st DIFI offset  ;\the active one is selected            (200h)
      118h 110h 8   2nd DIFI offset  ;/via below Active flag)                (330h)
      120h 118h 8   DIFI+IVFC+DPFS+SHA256 table size (12Ch) (or 12Ch*2 when two?)
      128h -    8   Partition A DIFI+IVFC+DPFS+SHA256 offset in active DIFI     (0)
      130h -    8   Partition A DIFI+IVFC+DPFS+SHA256 size                   (12Ch)
      138h -    8   Partition B DIFI+IVFC+DPFS+SHA256 offset in active DIFI  (0) ;?
      140h -    8   Partition B DIFI+IVFC+DPFS+SHA256 size               (0) ;12Ch?
      148h 120h 8   Partition A offset (DPFS flags, IVFC SHA's, ...      (1000h)
      150h 128h 8   Partition A size                                     (3F000h)
      158h -    8   Partition B offset                                   (0)
      160h -    8   Partition B size                                     (0)
      168h 130h 4   Active DIFI+IVFC+DPFS+SHA256 flag (0=2nd DIFI, 1=First DIFI)
      16Ch 134h 20h Active DIFI+IVFC+DPFS+SHA256 table SHA256
      -    154h 8   Unique identifier for Extdata (zero for title database)
      18Ch 15Ch ..  Unused (up to 1FFh), might contain leftover data

When the partition count is 1, there is no partition B and all of its related fields are zero.
DIFI table
All offsets are relative to the beginning of the DIFI partition descriptor, except for External IVFC level 7 offset, which is relative to the beginning of the partition.

      000h 8     ID "DIFI",00h,00h,01h,00h
      008h 8     IVFC descriptor offset (44h) ;\checksum tree SHA256's   ;"IVFC"
      010h 8     IVFC descriptor size   (78h) ;/
      018h 8     DPFS descriptor offset (BCh) ;\active/inactive data pair flags
      020h 8     DPFS descriptor size   (50h) ;/
      028h 8     SHA256 Partition hash offset (10Ch) ;\aka "Partition master hash"?
      030h 8     SHA256 Partition hash size  (20h*N) ;/
      038h 1     IVFC level 7 location (0=Internal, Nonzero=External) (usually 0)
      039h 1     Active flag for DPFS Level 1 (0=1st half, 1=2nd half)
      03Ah 2     Padding (0)
      03Ch 8     External IVFC level 7 offset (zero if Internal IVFC level 7)
      044h 78h   IVFC descriptor (see below)
      0BCh 50h   DPFS descriptor (see below)
      10Ch 20h*N SHA256 Partition master hash list (SHA's for Level 4)
      (then followed by another DIFI+IVFC+DPFS+SHA256 for partition B, if any?)

Note: There are two DIFI tables (the active one being selected in DISA[168h]/DIFF[130h]). Both DIFI's are usually containing the exact same offsets and sizes (and do differ only by Flag in DIFI[039h] and the SHA's at DIFI[10Ch]) (however, the inactive DIFI may initially contain unformatted garbage).
DPFS descriptor
This header defines each level of DPFS tree. All offsets are relative to the beginning of the partition.

      000h 8   ID "DPFS",00h,00h,01h,00h
      008h 8   Level 1 offset        (usually 0)                     ;\Flags for
      010h 8   Level 1 size per half (usually 4, or N*4 if bigger)   ; Level 2
      018h 8   Level 1 block size    (unused, usually 0)             ;/
      020h 8   Level 2 offset        (usually N*4*2, at level 1 end) ;\Flags for
      028h 8   Level 2 size per half (usually 80h*N)                 ; Level 3
      030h 8   Level 2 block size    (1 SHL N, usually 7=80h bytes)  ;/
      038h 8   Level 3 offset        (usually 1000h-aligned)         ;\IVFC's
      040h 8   Level 3 size per half (usually 1000h*N)               ; (SHA's+Data)
      048h 8   Level 3 block size  (1 SHL N, usually 12=1000h bytes) ;/

The flags are stored in 32bit snippets, weirdly with bit31 being the 1st block (that can be resolved as "BitNumber=BlockNumber XOR 1Fh"). The flags are selecting the active half of the next level (0=1st Half, or 1=2nd Half).
The above DPFS "size" values refer to "one half" (the 1st half is at "offset", the 2nd half is at "offset+size").
3DS Files - Savedata DISA and DIFF - Data Pairs
IVFC descriptor
This header defines each level of IVFC tree. All offsets are relative to
the beginning of the active half of DPFS level 3.

      000h 8   ID "IVFC",00h,00h,02h,00h
      008h 8   Master hash size = partition master hash size in DIFI header (N*20h)
      010h 8   Level 4 offset (usually 0)                           ;\SHA's for
      018h 8   Level 4 size   (usually 20h, or N*20h if bigger)     ; Level 5
      020h 8   Level 4 block size (1 SHL N, usually 9=200h bytes)   ;/
      028h 8   Level 5 offset (usually 20h, aka level 1 end)        ;\SHA's for
      030h 8   Level 5 size   (usually 20h, or N*20h if bigger)     ; Level 6
      038h 8   Level 5 block size (1 SHL N, usually 9=200h bytes)   ;/
      040h 8   Level 6 offset (usually 40h, aka level 2 end)        ;\SHA's for
      048h 8   Level 6 size   (usually 20h*N)                       ; Data
      050h 8   Level 6 block size (1 SHL N, usually 12=1000h bytes) ;/
      058h 8   Level 7 offset (unused for External IVFC Level 7)    ;\Data (eg.
      060h 8   Level 7 size   (usually 1000h*N)                     ; SAVE filesys)
      068h 8   Level 7 block size (1 SHL N, usually 12=1000h bytes) ;/
      070h 8   IVFC descriptor size? (usually 78h)

The above IVFC "size" values refer to "one half" (the 1st half is at "offset", the 2nd half is at "offset+level3size").
3DS Files - Savedata DISA and DIFF - Checksums

3DS Files - Savedata DISA and DIFF - Data Pairs

      DPFS might be short for
        DataPair...
        DuPlicates
        PersistentData structure (DP backwards)

Loading active blocks
To read data from src_offset (eg. begin of SAVE filesystem at src_offset=0):

      load the active difi/ivfc/dpfs block
      if external_flag_from_DIFI[38h] then
        readbytes(partition_base+external_level7_base+src_offset, len)
      else
        level3_byte_addr = level7_base+src_offset
       snippet_loop:
        snippet_len = min(len, distance to level3_blocksize boundary)
        level2_bit_index = (level3_byte_addr/level3_blocksize) xor 1Fh    ;\
        level2_byte_addr = (level2_bit_index/8)                           ;
        level1_bit_index = (level2_byte_addr/level2_blocksize) xor 1Fh    ;
        level1_byte_addr = (level1_bit_index/8)                           ;/
        base1 = level1_base+level1_size*(active_flag_from_DIFI[039h])
        flag1 = readbyte(level1_byte_addr+base1, size=1)
        base2 = level2_base+level2_size*((flag1 shr (level1_bit_index AND 7) AND 1)
        flag2 = readbyte(level2_byte_addr+base2, size=1)
        base3 = level3_base+level3_size*((flag2 shr (level2_bit_index AND 7) AND 1)
        data  = readbytes(level3_byte_addr+base3, snippet_len)
        raise src/dst, decrease len by snippet_len, if len>0 then goto snippet_loop

Partition
A partition can have two types of layout. This is determined by the field DIFI+38h (Enable external IVFC level 7).
The layout type 0 (external IVFC level 7 disabled) contains

      DPFS Level 1         (contains active flags for DPFS level 2)
      DPFS Level 2         (contains active flags for DPFS level 3)
      DPFS Level 3         (contains IVFC levels and Data?)
        IVFC Level 4         (contains SHA256's for IVFC level 5)
        IVFC Level 5         (contains SHA256's for IVFC level 6)
        IVFC Level 6         (contains SHA256's for IVFC level 7)
        IVFC Level 7         (contains the actual content data)

The layout type 1 (external IVFC level 4 enabled) contains

      DPFS Level 1     ;Flags for DPFS Level 2
      DPFS Level 2     ;Flags for DPFS Level 3
      DPFS Level 3, and inside
        IVFC Level 4     ;SHA256's on IVFC Level 5
        IVFC Level 5     ;SHA256's on IVFC Level 6
        IVFC Level 6     ;SHA256's on IVFC Level 7
      IVFC Level 7 ;the actual content data, note that this is outside DPFS level 3

Summary diagram
external link: https://i.imgur.com/BjwShJZ.png
Please move this into 3dbrew when file uploading is fixed.

3DS Files - Savedata DISA and DIFF - Checksums

AES CMAC
The AES CMAC is located at the beginning of the DISA / DIFF image, and it is 10h long. The rest F0h bytes before the header are unused.
The key used for the AES CMAC is generated by the hardware key engine.
The data being authenticated by the AES CMAC is a 20h-byte SHA-256 hash of a data block.

      CTR-NOR0 This CMAC type is used for gamecard savegames, 28h-bytes
        000h 8    ID "CTR-NOR0"                             ;\CMAC area
        008h 20h  SHA-256 of the following 108h-byte block  ;/
        028h 8    ID "CTR-SAV0"
        030h 100h Copy of the DISA header
      CTR-SIGN This CMAC type is used for SD savegames, 30h-bytes
        000h 8    ID "CTR-SIGN"                             ;\
        008h 8    Title ID                                  ; CMAC area
        010h 20h  SHA-256 of the following 108h-byte block  ;/
        030h 8    ID "CTR-SAV0"
        038h 100h Copy of the DISA header
      CTR-SYS0 This CMAC type is used for NAND system save, 110h-bytes
        000h 8    ID "CTR-SYS0"
        008h 8    Save ID. The higher word is always zero
        010h 100h Copy of the DISA header
      CTR-EXT0 This CMAC type is used for extdata, 11Ch-bytes
        000h 8    ID "CTR-EXT0"
        008h 8    Extdata ID                eg. "00048000\x00000xx\" ?
        010h 4    0 for Quota.dat, 1 otherwise
        014h 4    ID in the "device" file name  "\00000000\nnnnnnnn" ?  ;\zero for
        018h 4    ID in the "device" directory name that the file is in ;/Quota.dat
        01Ch 100h Copy of the DIFF header
      CTR-9DB0 This CMAC type is used for title database, 10Ch-bytes
        000h 8    ID "CTR-9DB0"
        008h 4    Database .db file ID (0..5, see below)
        00Ch 100h Copy of the DIFF header
        The Database .db file IDs are:
        0=ticket.db, 1=certs.db, 2=title.db, 3=import.db, 4=tmp_t.db, 5=tmp_i.db

Here is a summary table of the CMAC type and the AES key slot used:

      Usage           Media    Format  CMAC type       CMAC Keyslot
      Savegames       Gamecard DISA    CTR-NOR0        19h/33h
      Savegames       SD       DISA    CTR-SIGN        30h
      System SaveData NAND     DISA    CTR-SYS0        30h
      Private Extdata SD       DIFF    CTR-EXT0        30h
      Shared Extdata  NAND     DIFF    CTR-EXT0        30h
      Title Database  SD       DIFF    CTR-9DB0        30h
      Title Database  NAND     DIFF    CTR-9DB0        0Bh

Note: The AES keyslots are known (shown above), but the AES IV appears to be unknown?
IVFC tree
The IVFC tree is used for data verification. It is very similar to the IVFC tree in RomFS, except that it has an additional level here. For level 4, 5 and 6, each level is a list of SHA-256 hash, of which each corresponds to a block of the next level which is zero-padded to align the block size (the block size of the next level is defined in the IVFC descriptor).
The partition master hash in the partition descriptor can be seen as IVFC level 0, which hashes level 4 following the same rule. The master hash is usually 20h long, consisting only one hash. This is because most DISA / DIFF files are not large enough to have multiple hashes on the top level, which isn't the case for some title database files.
However, not all data is hashed - only ranges that have been written with valid data are properly hashed.
Level 7 is the actual content of the partition, which is what the container format essentially contains.
IVFC Chain of trust
AES CMAC verifies the header.
The header verifies the active partition table via the table hash.
In the partition table, each descriptor verifies level 4 of its IVFC tree via the master hash.
Each IVFC level verifies the next level, until the level 7, which is the inner content (eg. the SAVE file system).

3DS Files - Savedata Gamecard FLASH Encryption and Wear Leveling

Unlike SD and NAND savegames, Gamecard savegames have and additional Encryption and Wear Leveling layer.

     ________________________ Gamecard savegame Encryption ________________________

Repeating CTR Fail (newbie guide on what is a repeating 512-byte keystream)
On the 3DS savegames are stored much like on the DS, that is on a FLASH chip in the gamecart. On the DS these savegames were stored in plain-text but on the 3DS a layer of encryption was added. This is AES-CTR, as the contents of several savegames exhibit the odd behavior that xor-ing certain parts of the savegame together will result in the plain-text appearing.
The reason this works is because the stream cipher used has a period of 512 bytes. That is to say, it will repeat the same keystream after 512 bytes. The way you encrypt with a stream cipher is you XOR your data with the keystream as it is produced. Unfortunately, if your streamcipher repeats and you are encrypting a known plain-text (in our case, zeros) you are basically giving away your valuable keystream.
Savegame keyY
All gamecard and (!!?!!) SD savegames are encrypted with AES-CTR. The base CTR for gamecard savegames is all-zero. The gamecard savegame keyslots' keyY (these savegame keyslots use the hardware key-generator) is unique for each region and for each game. The NCSD partition flags determine the method used to generate this keyY. When the save NCSD flags checked by the running NATIVE_FIRM are all-zero, the system will use the repeating CTR, otherwise a proper CTR which never repeats within the image is used.
The AES-CMAC (which uses a hardware key-generator keyslot, as mentioned above) at the the beginning of the savegame must match the calculated CMAC using the DISA/DIFF data, otherwise the savegame is considered corrupted (see below).
When all of the flags checked by the running NATIVE_FIRM are clear, the keyY (original keyY method used with saves where the CTR repeats within the image) is the following:

      00h 8     First 8-bytes from the plaintext CXI accessdesc signature.
      08h 4     u32 CardID0 from gamecard plaintext-mode command 0x90,
                  Process9 reads this with the NTRCARD hw. The actual cmdID used
                  by Process9 is different since Process9 reads it with the
                  gamecard in encrypted-mode.
      0Ch 4     u32 CardID1 from gamecard plaintext-mode command 0xA0,
                  Process9 reads this with the NTRCARD hw. The actual cmdID used
                  by Process9 is different since Process9 reads it with the
                  gamecard in encrypted-mode.

2.0.0-2 Hashed keyY and 2.2.0-4 Savegame Encryption
When certain NCSD partition flags are set, a SHA-256 hash is calculated over the data from the CXI (same data used with the original plain keyY), and the 0x40-bytes read from a gamecard command (this 0x40-byte data is also read by GetRomId, which is the gamecard-uniqueID). The first 0x10-bytes from this hash is used for the keyY. When flag[7] is set, the CTR will never repeat within the save image, unlike the original CTR-method. All games which had the retail NCSD image finalized after the 2.2.0-4 update (and contain 2.2.0-4+ in the System update partition), use this encryption method.
This keyY generation method was implemented with 2.0.0-2 via NCSD partition flag[3], however the proper CTR wasn't implemented for flag[7] until 2.2.0-4. The hashed keyY flag[3] implemented with 2.0.0-2 was likely never used with retail gamecards.
6.0.0-11 Savegame keyY

      XXX also used/similar for NCCH "Keyslot25h" ???

6.0.0-11 implemented support for generating the savegame keyY with a new method, this method is much more complex than previous keyY methods. This is enabled via new NCSD partition flags, all retail games which have the NCSD image finalized after the 6.0.0-11 release (and 6.0.0-11+ in the system update partition) will have these flags set for using this new method.
A SHA-256 hash is calculated over the same data used with the above hashed keyY method, after hashing the above data the following data is hashed: the CXI programID, and the ExeFS:/.code hash from the decrypted ExeFS header. An AES-CMAC (the keyslot used for this uses the hardware key-scrambler) is then calculated over this hash, the output CMAC is used for the savegame keyY.
The keyY used for calculating this AES-CMAC is initialized while NATIVE_FIRM is loading, this keyY is generated via the RSA engine. The RSA slot used here is slot0 (key-data for slot0 is initialized by bootrom), this RSA slot0 key-data is overwritten during system boot. This RSA slot0 key-data gets overwritten with the RSA key-data used for verifying RSA signatures, every time Process9 verifies any RSA signatures except for NCCH accessdesc signatures. Starting with 7.0.0-13 this key-init function used at boot is also used to initialize a separate keyslot used for the new NCCH encryption method.
This Process9 key-init function first checks if a certain 0x10-byte block in the 0x01FF8000 region is all-zero. When all-zero it immediately returns, otherwise it clears that block then continues to do the key generation. This is likely for supporting launching a v6.0+ NATIVE_FIRM under this FIRM.

     ___________________________ Gamecard wear leveling ___________________________

The 3DS employs a wear leveling scheme on the savegame FLASH chips (only used for CARD1 gamecards). This is done through the usage of blockmaps and a journal. The blockmap is located at offset 0 of the flash chip, and is immediately followed by the journal. The initial state is dictated by the blockmap, and the journal is then applied to that.
First, there are 8 bytes whose purposes are currently unknown. Then comes the actual blockmap. The blockmap structure is simple:

      struct header_entry {
        uint8_t phys_sec  ;when bit7=1: block has chksums (else chksums are all 0)
        uint8_t alloc_cnt
        uint8_t chksums[8]
      } __attribute__((__packed__));

There's one entry per sector, counting from physical sector 1 (sector 0 contains the blockmap/journal).
The 2 bytes that follow the blockmap are the CRC16 (with initial value FFFFh) of the first 8 bytes and the blockmap.
Then comes the journal. The journal structure is as follows:

      struct sector_entry {
        uint8_t virt_sec         ;Mapped to sector
        uint8_t prev_virt_sec    ;Physical sector previously mapped to
        uint8_t phys_sec         ;Mapped from sector
        uint8_t prev_phys_sec    ;Virtual sector previously mapped to
        uint8_t phys_realloc_cnt ;Amount of times physical sector has been remapped
        uint8_t virt_realloc_cnt ;Amount of times virtual sector has been remapped
        uint8_t chksums[8]
      } __attribute__((__packed__));

      struct long_sector_entry{
        struct sector_entry sector
        struct sector_entry dupe
        uint32_t magic           ;With magic being a constant 080D6CE0h.
      }__attribute__((__packed__));

The checksums in the blockmap/journal entries work as follows:
each byte is the checksum of an encrypted 200h bytes large block,
to calculate the checksum, a CRC16 of the block (with initial value FFFFh) is calculated, and the two bytes of the CRC16 are XORed together to produce the 8bit checksum

3DS Files - Messages (MsgStdBn)

Message files contain text messages, usually there are separate message files for different languages (in separate folders).

      <name>.msbt (MsgStdBn format) - Message Text
      <name>.msbp (MsgPrnBn format) - Message Project/styles (if present)
      RI.mstl     (raw binary)      - Unknown purpose

MsgStdBn Header (<file>.msbt)

      000h 8     ID "MsgStdBn"
      008h 2     Byte Order (FEFFh)
      00Ah 2     Zero (0)
      00Ch 1     Message encoding (0=UTF-8, 1=UTF-16, 2=UTF-32)
      00Dh 1     Version number (always 3)
      00Eh 2     Number of following Chunks (4=LBL1+ATR1+TXT2+TSY1 or 2=NLI1+TXT2)
      010h 2     Zero (0)
      012h 4     Total Filesize (unaligned 32bit)
      016h 0Ah   Zero (0)

LBL1 Chunk (Labels)

      000h 4       Chunk ID "LBL1"
      004h 4       Chunk Size (minus 10h, and excluding 16-byte padding)
      008h 8       Padding (0)
      010h 4       Number of Hash Table Entries (always 65h in MsgStdBn files)
      014h N*(4+4) Number of Matches + Offset to 1st match (from LBL1+10h)
      ...  ..      Label strings (8bitLen+Chars+32bitIndexIntoTXT2)
      ..   ..      Padding to 16-byte boundary (ABh-filled)

Hash Table Entries

      000h 4       Number of matching labels (0=None)
      004h 4       Offset to 1st matching label (from LBL1+10h) (garbage if None)

Label Strings

      000h  1      Label String length (LEN)
      001h  LEN    Label String (ASCII) (without any ending 00h byte)
      1+LEN 4      Message Index in TXT2 Chunk (unaligned 32bit)

ATR1 Chunk (Attributes)

      000h 4      Chunk ID "ATR1"
      004h 4      Chunk Size (minus 10h, and excluding 16-byte padding)
      008h 8      Zero (0)
      010h 4      Number of Messages (N) (same as in TXT2 chunk)
      014h 4      Bytes per Attribute (siz) (0=None)
      ...  N*4    offsets to attributes from ATR1+10h  ;\only present if siz<>0
      ...  N*siz  attributes? (voice/window style?)    ;/
      ..   ..     Padding to 16-byte boundary (ABh-filled)

TXT2 Chunk (Text Strings)

      000h 4     Chunk ID "TXT2"
      004h 4     Chunk Size (minus 10h, and excluding 16-byte padding)
      008h 8     Zero (0)
      010h 4     Number of Messages (N)
      014h N*4   Offsets to Strings (from TXT2+10h)
      ...  ..    Strings (usually in UTF-16, terminated by 0000h)
      ..   ..    Padding to 16-byte boundary (ABh-filled)

UTF-16 Characters:

      0000h=End of String (except inside Escape sequences)
      000Ah=Linebreak
      000Eh=Escape Code (change text color, etc.)
      00xxh=ASCII Characters 20h..7Eh

Escape Sequences:

      000h 2     Escape Code (000Eh)
      002h 2     Command Type
      004h 2     Command SubType
      006h 2     Number of following parameter bytes (0=None) (usually even)
      008h N     Parameters

Command Type.SubType are maybe somewhat like so:

      0000h.0003h Change Color maybe (param16bit) ?
      0000h.000xh Change other stuff maybe, like font size?

There is probably also something for inserting User Name or other strings and numeric variables, sound effects, and perhaps something for prompting user input?
TSY1 Chunk (Style Info)

      000h 4     Chunk ID "TSY1"
      004h 4     Chunk Size (minus 10h, and excluding 16-byte padding) (NumMsg*4)
      008h 8     Zero (0)
      010h N*4   Style index in MSBP file (aka MsgPrjBn) (FFFFFFFFh=None?)
      ..   ..    Padding to 16-byte boundary (ABh-filled)

Uh, 3DS System Settings has Style Index values 0, 1, 2, and FFFFFFFFh (but doesn't has a .msbt file at all).
NLI1 Chunk (reportedly used in some files, instead of LBL1/ATR1/TSY1?)

      0x00h 4        Chunk ID "NLI1"
      0x04h 4        Chunk Size (minus 10h, and excluding 16-byte padding)
      0x08h 8        Zero
      0x10h 4        Number of entries
      0x14h N*(4+4)  Whatever List (Message ID? and Offset in TXT2)

Hash Tables
Many items (such as messages in msbt files or colors in msbp files) are looked up by label. The labels are looked up with a hash table and are stored in a different block than the items themselves. In official files the hash table always has a fixed number of slots (101 in msbt files, 29 in msbp files), even if it contains only a few labels.

      The following hash algorithm is used:
      def calc_hash(label, num_slots):
        hash = 0
        for char in label:
            hash = hash * 492h + ord(char)
        return (hash AND 0FFFFFFFFh) MOD num_slots

The block with the labels contains the following data:

      000h 4       Number of slots
      004h 8*N     Hash table slots
      ...  ..      Labels

Hash Table Slot

      000h 4       Number of labels
      004h 4       Offset to labels

Label

      000h 1       Length of label string
      001h ..      Label string (without null terminator)
      ...  4       Item index

     __________________________ MsgPrjBn (aka .msbp file)__________________________

MsgPrjBn Header (<file>.msbp) (if any)

      000h 8     ID "MsgPrjBn"
      008h 2     Byte Order (FEFFh)
      00Ah 2     Zero (0)
      00Ch 1     Message encoding (0=UTF-8, 1=UTF-16, 2=UTF-32) (usually 0 ??)
      00Dh 1     Version number (always 3)
      00Eh 2     Number of following Chunks (12=CLR1+CLB1+ATI2+ALB1+etc.)
      010h 2     Zero (0)
      012h 4     Total Filesize (unaligned 32bit)
      016h 0Ah   Zero (0)

This file contains style information for text messages.

      CLR1    Color RGBA Values     ;\Colors
      CLB1    Color Labels          ;/
      ATI2    Attribute Information ;\
      ALB1    Attribute Labels      ; Attributes
      ALI2    Attribute Lists       ;/
      TGG2    Tag Groups            ;\
      TAG2    Tags                  ; Tags
      TGP2    Tag Parameters        ;
      TGL2    Tag Lists             ;/
      SYL3    Styles                ;\Styles
      SLB1    Style Labels          ;/
      CTI1    Project Content Info  ;-Contents

The overall chunk format is:

      000h 4       Chunk ID   (eg. "CLR1")
      004h 4       Chunk Size (minus 10h, and excluding 16-byte padding)
      008h 8       Padding (0)
      010h ..      Data (depending on chunk)
      ..   ..      Padding to 16-byte boundary (ABh-filled)

     ______________________________ MsgPrjBn Colors _______________________________

CLR1 Chunk (Color RGBA Values)

      000h 4+4+8   Chunk ID "CLR1", Chunk Size, Zeroes
      010h 4       Number of Colors
      014h N*4     Colors (RGBA)
      ..   ..      Padding to 16-byte boundary (ABh-filled)

CLB1 Chunk (Color Labels)

      000h 4+4+8   Chunk ID "CLB1", Chunk Size, Zeroes
      010h 4       Number of Hash Table Entries (always 1Dh in MsgPrjBn files)
      014h N*(4+4) Number of Matches + Offset to 1st match (from CLB1+10h)
      ...  ..      Label strings (8bitLen+Chars+32bitIndexIntoCLR1)
      ..   ..      Padding to 16-byte boundary (ABh-filled)

Color Labels can be "Red", "Write, "Blue", for example.

     ____________________________ MsgPrjBn Attributes _____________________________

ATI2 Chunk (Attribute Information)

      000h 4+4+8   Chunk ID "ATI1", Chunk Size, Zeroes
      010h 4       Number of attributes (0=None)
      014h 8*N     Attributes

Attribute Format:

      000h 1       Type
      001h 1       Padding
      002h 2       List index (in ALI2 block, only valid if the type=9)
      004h 4       Offset

ALB1 Chunk (Attribute Labels)

      000h 4+4+8   Chunk ID "ALB1", Chunk Size, Zeroes
      This block contains labels for the ATI2 block.

The Hash slots can be all empty without any strings (eg. as so in DSi-to-3DS Transfer Tool).
ALI2 Chunk (Attribute Lists)

      000h 4+4+8   Chunk ID "ALI2", Chunk Size, Zeroes
      010h 4       Number of lists
      014h 4*N     Offsets to attribute lists
      ...     ..   Attribute lists

Attribute List

      000h 4       Number of list items
      004h 4*N     Offsets to list item names
      ...  ..      Null-terminated list item names

     _______________________________ MsgPrjBn Tags ________________________________

TGG2 Chunk (Tag Groups)

      000h 4+4+8   Chunk ID "TGG2", Chunk Size, Zeroes
      010h 2       Number of tag groups
      012h 2       Padding
      014h 4*N     Offsets to tag groups
      ...  ..      Tag groups

Tag Group

      000h 2       Number of tags
      002h 2*N     Tag indexes (in TAG2 block)
      ...  ..      Null-terminated tag group name

Tag Groups can be "UserName", "DayTime", "ErrorInfo", for example.
TAG2 Chunk (Tags)

      000h 4+4+8   Chunk ID "TAG2", Chunk Size, Zeroes
      010h 2       Number of tags
      012h 2       Padding
      014h 4*N     Offsets to tags

Tag

      000h 2       Number of tag parameters
      002h 2*N     Tag parameter indexes (in TGP2 block)
      ...  ..      Null-terminated tag name

Tags can be "MyName", "SenderName" "Hour", "Minute", "ErrorCode", for example.
TGP2 Chunk (Tag Parameters)

      000h 4+4+8   Chunk ID "TGP2", Chunk Size, Zeroes
      010h 2       Number of parameters
      012h 2       Padding
      014h 4*N     Offsets to parameters

Tag Parameter

      000h 1       Parameter type
     If type is not 9:
      001h ..      Null terminated parameter name
     If type is 9:
      001h 1       Padding
      002h 2       Number of tag list items
      004h 2*N     List item indexes (in TGL2 block)
      ...  ..      Null terminated parameter name

Parameter names can be "face", "percent", "r", "g", "b", "a", "name", for example.
TGL2 Chunk (Tag Lists)

      000h 4+4+8   Chunk ID "TGL2", Chunk Size, Zeroes
      010h 2       Number of list items (0=None)
      012h 2       Padding
      014h 4*N     Offsets to list item names
      ...  ..      Null-terminated list item names

     ______________________________ MsgPrjBn Styles _______________________________

SYL3 Chunk (Styles)

      000h 4+4+8   Chunk ID "SYL3", Chunk Size, Zeroes
      010h 4       Number of styles
      014h 16*N    Styles

Style

      000h 4       Region width (in pixels? max FFh on DSi)
      004h 4       Line num (position? or Height?) (usually 1 or more)
      008h 4       Font index (eg. 0,1,2 for type, or small/med/large maybe?)
      00Ch 4       Base color index (uh, what?) (usually FFFFFFFFh) (or 0)

SLB1 Chunk (Style Labels)

      000h 4+4+8   Chunk ID "SLB1", Chunk Size, Zeroes
      This block contains labels for the SYL3 block.

Style names can be "commonBtn_D_1_T_sysBtnL_00" or the like.

     ______________________________ MsgPrjBn Content ______________________________

CTI1 Chunk (Project Content Info)
This block contains the names of the source files that the MSBT files were generated from. The source files have the .mstxt extension.

      000h 4+4+8   Chunk ID "CTI1", Chunk Size, Zeroes
      010h 4       Number of filenames
      014h 4*N     Offsets to filename strings (from CTI1+10h)
      ...  ..      Null-terminated source filename strings (eg. "cardboard.mstxt")

     ________________________________ RI.mstl file ________________________________

RI.mstl file (unknown purpose)

      000h 4      Number of whatevers
      004h N*2Ch  Whatevers

3DS Files - Video Icons (SMDH)

This page describes the format of the icon stored at CXI ExeFS:/icon and CIA icons. The CXI icon is displayed by Home Menu and System Settings (3DS Software Management), while CIA icons are dummies and not yet utilised by Dev 3DS' (as of rev 47586).
Icon File Format (36C0h bytes)

      0000h 4     ID "SMDH"
      0004h 2     Version (unknown/unspecified) (value 0000h exists)
      0006h 2     Reserved (0)
      0008h 200h  Title Japanese             ;\
      0208h 200h  Title English              ;
      0408h 200h  Title French               ; Each 200h-byte entry consists of:
      0608h 200h  Title German               ;   80h-byte   Short Description
      0808h 200h  Title Italian              ;   100h-byte  Long Description
      0A08h 200h  Title Spanish              ;   80h-byte   Publisher
      0C08h 200h  Title Simplified Chinese   ; All encoded in UTF-16
      0E08h 200h  Title Korean               ;
      1008h 200h  Title Dutch                ;
      1208h 200h  Title Portuguese           ;
      1408h 200h  Title Russian              ;
      1608h 200h  Title Traditional Chinese  ;
      1808h 200h  Title Reserved             ;
      1A08h 200h  Title Reserved             ;
      1C08h 200h  Title Reserved             ;
      1E08h 200h  Title Reserved             ;/
      2008h 1     Age Rating CERO (Japan)
      2009h 1     Age Rating ESRB (USA)
      200Ah 1     Age Rating Reserved
      200Bh 1     Age Rating USK (German)
      200Ch 1     Age Rating PEGI GEN (Europe)
      200Dh 1     Age Rating Reserved
      200Eh 1     Age Rating PEGI PRT (Portugal)
      200Fh 1     Age Rating PEGI BBFC (England)
      2010h 1     Age Rating COB (Australia)
      2011h 1     Age Rating GRB (South Korea)
      2012h 1     Age Rating CGSRR (Taiwan)
      2013h 1     Age Rating Reserved
      2014h 1     Age Rating Reserved
      2015h 1     Age Rating Reserved
      2016h 1     Age Rating Reserved
      2017h 1     Age Rating Reserved
      2018h 4     Region Lockout (bit0=JPN, bit1=USA, bit2=EUR, bit3=AUS, bit4=CHN,
                    bit5=KOR, bit6=TWN, bit7-31=Reserved) (7FFFFFFFh=Region Free)
      201Ch 4     Match Maker ID      ;\Match Maker IDs (Online Play)
      2020h 8     Match Maker BIT ID  ;/
      2028h 4     Flags
      202Ch 1     EULA Version Minor  ;\
      202Dh 1     EULA Version Major  ;/
      202Eh 2     Reserved
      2030h 4     'Optimal Animation Default Frame' (for BNR) (uh, maybe preview?)
      2034h 4     CEC (StreetPass) ID (So the Home Menu knows which application
                    icon to show the 'Green' CEC notification for)
      2038h 8     Reserved
      2040h 480h  Small Icon (24x24pix, shown on top screen when pausing the app)
      24C0h 1200h Large Icon (48x48pix, the general icon)

Flags [2028h]

      0     Visibility Flag (Required for visibility on the Home Menu) (1=show?)
      1     Auto-boot this gamecard title
      2     Allow use of 3D? (For use with parental Controls. An application
              can use the 3D affect, even when this flag isn't set)
      3     Require accepting CTR EULA before being launched by Home
      4     Autosave on exit? (see below)
      5     Uses an Extended Banner?
      6     Region game rating required
      7     Uses save data? (see below)
      8     Application usage is to be recorded. If this is zero, it causes
              the application's usage to be omitted from the Home Menu's icon
              cache, as well as in other places.
      9     unknown/unspecified
      10    Disables SD Savedata Backups for this title. This is in addition to
             the blacklist.
      11    unknown/unspecified
      12    New 3DS exclusive title. Shows an error if used on Old 3DS.
      13-31 unknown/unspecified

Age Rating: Active ratings have a bitmask of 80h, and inactive ratings have no bitmask at all. Ratings without the 80h bitmask are ignored. 40h bitmask indicates Rating Pending. 20h bitmask indicates No Age Restriction. Age limits are set by adding the minimal age to 80h (for example, limiting to 12 years and up would give a bitmask of 8Ch)
Region Lockout: Regions are 'included' in region lock by setting their bitmask value. Nintendo defines region free as 7FFFFFFFh. Early in the 3DS' development, Nintendo grouped the Australian and Europe markets together. Nintendo defines market Europe as having the combined bitmasks of Europe and Australia. No 3DS' which check the Australia bitmask have been seen (Australia uses the European 3DS model).
The EULA version is checked when the Accept EULA flag is set, the version is compared to one stored in the 3DS. If the SMDH version is greater, then the user will be prompted to accept the EULA.
Effect of SaveData and AutoSave
These options have no effect on the performance of the application itself: they're used to select an appropriate warning when closing an application from Home.
Both off: "Closing software" (no warning if quitting directly with X)
SaveData: "Do you want to close [...]? (Unsaved data will be lost.)"
AutoSave: ?
Both on: "Saving data and closing software..." (no warning if quitting directly with X)
'Optimal Animation Default Frame' (for BNR)
This is a float, indicating the preferred (or 'most representative') frame for the banner animation.
CEC (StreetPass) ID
This u32 represents the application CEC ID. This is likely loaded by applications for use with the CEC services as well.
Icon graphics
Both of the icons are encoded in RGB565 meaning 16bpp.
The data is encoded in tiles (starting from size 8x8, continuing recursively).

     If the buffer is like this:
      0       1       2       3       4       5       6       7       8       9
      10      11      12      13      14      15      16
     Then the image would look like this:
      x=0     x=1     x=2     x=3     x=4
      0       1       4       5       16
      2       3       6       7       ...
      8       9       12      13
      10      11      14      15
     Uh, are that pixels or 8x8pix tiles?
     Either way, how would that translate to actual 24x24pix or 48x48pix icons??

Although both icons are known to be RGB565, developers have the option of encoding icons (and banners) with the following encodings:

      RGBA8
      RGB8
      RGBA5551
      RGB565     (used)
      RGBA4
      LA8
      HILO8
      L8
      A8
      LA4
      L4
      ETC1
      ETC1A4

This does not necessarily mean the other encodings will be used, it is just that those are the options when compiling. Like we've seen with Super Mario 3D Land Nintendo has changed save file encryption, and "likewise" they can encode icons and banners differently should they choose to. Currently we've seen just RGB565 so don't be fooled if an icon doesn't show up right! It is probably one of these formats above. Although we will probably not see other formats used for a while it's nice to know they have an opportunity to change.
Also note that it seems Nintendo stores "each pixel in word-order", so the actual "order of order" of "each color channel" in memory will depend on the endianness. uh, what?
Tools

      CiTRUS - (GUI)(Windows Only) Generating ICN files (aka icon files)
      3DSExplorer - (GUI)(Windows Only) Parsing ICN files (aka icon files)

3DS Files - Video Banner (CBMD)

CBMD - CTR Banner Model Data (archive for CGFX/CWAV files)
These are stored in CXI ExeFS:/banner and optionally in extdata exbanner.
This is used for banners of titles you see in the home menu.
BNR used for the app banners in the CXI/exbanner is the same as CBMD with CWAV at the end (uh, who is "BNR", and is that CWAV always supported in all cases, or only for that "BNR" thing?).
CBMD Header

      000h 4     ID "CBMD"
      004h 4     Zero
      008h 4     CGFX Offset for Default (88h)  ;-main CGFX file (for all regions)
      00Ch 4     CGFX Offset for EUR-English    ;\
      010h 4     CGFX Offset for EUR-French     ; region-specific CGFX files
      014h 4     CGFX Offset for EUR-German     ; (or 0=None)
      018h 4     CGFX Offset for EUR-Italian    ; (these are smaller CGFX files,
      01Ch 4     CGFX Offset for EUR-Spanish    ; usually with one or two custom
      020h 4     CGFX Offset for EUR-Dutch      ; Textures) (3DS Activity Log has
      024h 4     CGFX Offset for EUR-Portuguese ; more custom entries though)
      028h 4     CGFX Offset for EUR-Russian    ; (Nintendo Network ID Settings
      02Ch 4     CGFX Offset for JPN-Japanese   ; doesn't have any custom CGFX's)
      030h 4     CGFX Offset for USA-English    ;
      034h 4     CGFX Offset for USA-French     ;    (unknown if CHN/KOR/TWN are
      038h 4     CGFX Offset for USA-Spanish    ;    also supported?)
      03Ch 4     CGFX Offset for USA-Portuguese ;/
      040h 44h   Padding (0)                    ;<-- XXX probably CHN/KOR/TWN here?
      084h 4     CWAV Offset for Sound wave data
      088h ..    CFGX/CWAV data area...

"The common CGFX is used if the CGFX offset for the system region/language is zero. Those optional offsets can be used in extdata exbanner, but separate CBMD banner files for each region/language can be used as well."
Entry Size
The header contains only offsets. To compute the size, search the next bigger offset (or use the filesize as max offset), and then subtract the current offset from that value. Note: The list does usually contain increasing offsets (but it may be a bad idea to rely on that, eg. EUR-Spanish and USA-Spanish might use the same offsets).
CGFX Graphics
3DS Files - Video Archive (CGFX)
Banner CGFX files are LZ11-compressed, the decompressed CGFX size shouldn't exceed 80000h bytes for banners.
CWAV Sound
3DS Files - Sound Wave Data (CWAV Format)
Banner CWAV total channels must be 2, and the length of the audio must be 3 seconds or less (uh, is that regardless of sample rate/sample size?), otherwise the sound will play incorrectly (beeping/clicking) or the model may fail to load.

3DS Files - Video Banner (Extended Banner)

Overview
The Extended Banner is used to add text (and optionally an extra texture) to a given banner. It can also (optionally) be used to set an expiration date for a banner.
See "\user\ExBanner\" for how the extended-banners are loaded from extdata. The Home Menu extended-banner loading function will immediately return without loading anything if the programID is for System Settings.
System titles using extended banners

      Mii Maker
      Face Raiders

Format - Extension: .BIN (...stored somewhere as extdata on SD card?)

      000h 2    Texture width (if texture is used)
      002h 2    Texture height (if texture is used)
      004h 2    Texture colour format (if texture is used)
      008h 4    Expire Date, Year    ;\
      00Ch 2    Expire Date, Month   ; what is that, ASCII? or 32bit year???
      010h 2    Expire Date, Day     ;/
      014h 15h  Name of texture (if texture is used) ;uh, 15h may mean 16 decimal?
      024h 200h Plain text comment (255 character max) to be displayed in the
                  banner on the HOME Menu (UTF-16 or so?)
      224h 80h  unknown/unspecified
      2A4h ..   Texture data (if any)

The date used for never-expiring exbanners varies, on retail like with Mii Maker this is 31 Dec 2099 (year=833h, month=0Ch, day=1Fh). The expiration-timestamp is only used for SpotPass exbanners, not extdata-exbanners.
Texture Colour Formats

      00h = RGBA8
      01h = RGB8
      02h = RGBA5551
      03h = RGBA565
      04h = RGBA4
      05h = LA8
      06h = HILO8
      07h = L8
      08h = A8
      09h = LA4
      0Ah = L4
      0Bh = A4
      0Ch = ETC1
      0Dh = ETC1A4

SpotPass
When Home Menu loads extended-banners, it also attempts to load a "CBMD" banner via SpotPass service commands. Normally this CBMD banner doesn't exist in extended-banner extdata. This is broken with New3DS titles since Home Menu uses these BOSS commands with the New3DS bitmask in the programID set. The common and language-specific (when offset is non-zero) "CGFX" specified by the CBMD are decompressed and processed.
The "CGFX" sections in this CBMD are actually the exact same exbanners loaded from normal extdata. The exbanner data from SpotPass is stored to the same state as the extdata-exbanners. No CWAV is loaded from SpotPass data.
The exbanners from SpotPass must have a timestamp less than current_datetime, otherwise they won't be parsed. The timestamp for the banner is calculated with: nintimestamp_mktime(out, exbanner->year, exbanner->month, exbanner->day, <hour=23>, <minute = 59>, <second = 59>, <millisecond = 999>);

3DS Files - Video Layout (CLYT/FLYT)

CLYT (.bclyt) is the layout format used on the 3DS. It stands for (Binary) CTR Layout, and is similar to the RLYT format used on the Wii.
FLYT is something similar (used in 3DS eShop applet RomFS:\layout\).
CLYT Header

      000h 4     ID ("CLYT")         ;or "FLYT"
      004h 2     Byte Order  (FEFFh)
      006h 2     Header Size (0014h)
      008h 4     Version (02020000h)
      00Ch 4     Total Filesize
      010h 4     Number of following Chunks

lyt1 (Layout)

      000h 4     Chunk ID "lyt1"
      004h 4     Chunk Size
      008h 4     Origin type (0=Classic, 1=Normal)
      00Ch 8     Vector2 Canvas Size

txl1 (Texture List)

      000h 4     Chunk ID "txl1"
      004h 4     Chunk Size
      008h 4     Number of Textures (N)
      00Ch N*4   Texture Name Offsets (relative to the start of this "array")
      ..  ..     null terminated names

fnl1 (Font List)

      000h 4     Chunk ID "fnl1"
      004h 4     Chunk Size
      008h 4     Number of Fonts (N)
      00Ch N*4   Font Name Offsets (relative to the start of this "array")
      ..  ..     null terminated names

mat1 (Materials)

      000h 4     Chunk ID "mat1"
      004h 4     Chunk Size
      008h 4     Number of Materials (N)
      00Ch N*4   Material Entry Offsets (relative to the start of this "section")

After this, the material entries follow.

      00h 14h   String    Material Name
      14h 4     RGBA8     Tev Color (Buffer Color?)
      18h 18h   RGBA8[6]  Tev Constant Colors
      30h 4     UInt32    Flags / bitfield
        Bit     Flag / data
        0-1     Nr texMap
        2-3     Nr texMatrix
        4-5     Nr texCoordGen
        6-8     Nr tevStage
        9       Has alphaCompare
        10      Has blendMode
        11      Use Texture Only
        12      Separate Blend Mode
        14      Has Indirect Parameter
        15-16   Nr projectionTexGenParameter
        17      Has Font Shadow Parameter

Texture Map Entry:

      00h 2     UInt16  Texture Index
      02h 1     Byte    Bitfield
                    Bit     Data
                    0-1     Wrap S     (0=Clamp, 1=Repeat, 2=Mirror)
                    2-3     Min Filter (0=Near, 1=Linear)
      02h 1     Byte    Bitfield        ;<-- uh, maybe at offset 03h?
                    Bit     Data
                    0-1     Wrap T     (0=Clamp, 1=Repeat, 2=Mirror)
                    2-3     Mag Filter (0=Near, 1=Linear)

Texture Matrix Entry:

      00h 8     Vector2 Translation
      08h 4     Single  Rotation
      0Ch 8     Vector2 Scale

TODO: texCoordGen, tevStage, alphaCompare, blendMode, etc...
pan1 (Pane)

      000h 4     Chunk ID "pan1"
      004h 4     Chunk Size
      008h 1     UInt8   Flags
                           Bit   Flag
                           0     Visible
                           1     InfluencedAlpha
                           2     LocationAdjust
      009h 1     UInt8   Origin
      00Ah 1     UInt8   Alpha
      00Bh 1     UInt8   Pane magnification flags
                           Bit   Flag
                           0     IgnorePartsMagnify
                           1     AdjustToPartsBounds
      00Ch 18h   String  Pane name
      024h 0Ch   Vector3 Translation
      030h 0Ch   Vector3 Rotation
      03Ch 8     Vector2 Scale
      048h 8     Vector2 Size

pic1 (Picture)

      000h 4     Chunk ID "pic1"
      004h 4     Chunk Size
      008h 4     RGBA8   Top left vertex color
      00Ch 4     RGBA8   Top right vertex color
      010h 4     RGBA8   Bottom left vertex color
      014h 4     RGBA8   Bottom right vertex color
      018h 2     UInt16  Material ID
      01Ah 2     UInt16  Nr texture coordinates = N
     Texture coordinates entry
      01Ch+N*20h 8     Vector2 Top left vertex texture coordinate
      024h+N*20h 8     Vector2 Top right vertex texture coordinate
      02Ch+N*20h 8     Vector2 Bottom left vertex texture coordinate
      034h+N*20h 8     Vector2 Bottom right vertex texture coordinate

txt1 (Text)
wnd1 (Window)
...?
bnd1 (Bounding)

      000h 4     Chunk ID "bnd1"
      004h 4     Chunk Size
      008h 2     UInt16? ?
      00Ah 2     UInt16? ?
      00Ch ? (0x10h up to 0x30h)     String  Bounding name
      03Ch 8     Vector2 ?
      044h 4     Vector2 ?
      ?    ?     ?       ?

pts1 (Parts 1)
...?
pas1 (Pane Start)

      000h 4     Chunk ID "pas1"
      004h 4     Chunk Size (08h)

pae1 (Pane End)

      000h 4     Chunk ID "pae1"
      004h 4     Chunk Size (08h)

grp1 (Group)
3 000h 4 Chunk ID "grp1"

      004h 4     Chunk Size (1Ch+(0..N)*10h)
      008h 10h   String  Group Name
      018h 4     UInt32  Nr Pane References (=N) (can be zero)
      01Ch 10h*N String[N]    Pane References

grs1 (Group Start)

      000h 4     Chunk ID "grs1"
      004h 4     Chnunk Size (08h)

gre1 (Group End)

      000h 4     Chunk ID "gre1"
      004h 4     Chunk Size (08h)

Tools

      Every File Explorer has limited support for viewing these

See also
http://florian.nouwt.com/wiki/index.php/CLYT_%28File_Format%29
https://github.com/Gericom/EveryFileExplorer/tree/master/3DS/NintendoWare/LYT1

3DS Files - Video Layout Animation (CLAN/FLAN)

     This article is a stub. You can help 3DBrew by expanding it.

CLAN (.bclan) is the layout animation format used on the 3DS. It stands for (Binary) CTR Layout Animation, and is similar to the RLAN format used on the Wii.
FLAN is something similar, used in 3DS eShop applet (RomFS:\layout\) and 3DS Browser applet (RomFS:\lyt\).
Header

      00h 4     String  ID ("CLAN")         ;or "FLAN"
      04h 2     UInt16  Byte Order (FEFFh)
      06h 2     UInt16  Header Size (14h)
      08h 4     UInt32  Revision
      0Ch 4     UInt32  File Size
      10h 4     UInt32  Nr Sections

pat1 (Pattern 1)

      00h 4     String  Signature (pat1)
      04h 4     UInt32  Section Size
      08h 4     UInt32  Flags?
      0Ch 4     UInt32  ?
      10h 4     Int32   ?
      14h 4     UInt32  ?
      18h 10h   String  Pattern name

pai1 (Pattern Instruction? 1)

      00h 4     String  Signature (pai1)
      04h 4     UInt32  Section Size
      08h 4     UInt32  ?
      0Ch 4     UInt32  Flags?
      10h 4     UInt32  Nr entries?
      14h 4     UInt32  Entries offset (relative to pai1)

Instruction? entry(ies)?

      00h 14h   String  Target panel name
      14h 4     UInt32  Flags?
      18h 4     UInt32  Animation entry offset (relative to entry)
      1Ch 4     UInt32  ? (if flag bit 1 is set)

Animation entry

      00h 4       String  Animation type
        Name    Description
        CLPA    CTR Layout Pane SRT (Scale/Rotate/Translate) animation.
        CLTS    CTR Layout Texture SRT animation.
        CLVI    CTR Layout Visibility animation.
        CLVC    CTR Layout Vertex Color animation.
        CLMC    CTR Layout Material Color animation.
        CLTP    CTR Layout Texture Pattern animation.
      04h 1       UInt8   Nr of animations
      05h 3       UInt8[3]        Padding
      ?   ?       ?       ?

See also

      http://wiki.tockdom.com/wiki/BRLAN
      http://wiibrew.org/wiki/Wii_Animations#Animations_.28.2A.brlan.29

3DS Files - Video Layout Images (CLIM/FLIM)

Unknown purpose, maybe some kind of images, ie. texture/bitmaps?
FLIM is something similar (used in 3DS eShop applet RomFS:\layout\).
Footer

     00000000h  ..  Images...
     Footer+00h 4   ID "CLIM"               ;or "FLIM"
     Footer+04h 2   Byte Order (FEFFh)
     Footer+06h 2   Footer Size (14h)
     Footer+08h 4   Version? (02020000h)
     Footer+0Ch 4   Total Filesize
     Footer+10h 4?  Maybe number of images? (00000001h)
     Footer+14h 4   Chunk ID "imag"     ;\
     Footer+18h 4   Chunk Size (10h)    ; image data is at offset 0
     Footer+1Ch 2   Width?              ; (if multiple images should be allowed...
     Footer+1Eh 2   Height?             ; next image is at WHICH offset?)
     Footer+20h 4?  Type? (0Dh = 4bpp?) ;/   ;<-- ETC1A4 ?
     Footer+24h 4   Footer Offset (from begin of file to "CLIM") ;<--at end of file

3DS Files - Video Archive (CGFX)

CGFX files exist as standalone files, and can be also found in CBMD banner archives, usually with LZ11 compression.
CGFX is a container format used to store graphics resources.
Overall CGFX Format
3DS Files - Video Archive (CGFX Header, Blocks, DICTs)
CGFX Sections
3DS Files - Video Archive (CGFX_00h - CMDL Models)
3DS Files - Video Archive (CGFX_01h - TXOB Textures)
3DS Files - Video Archive (CGFX_02h - LUTS Look-up Tables)
3DS Files - Video Archive (CGFX_04h - SHDR Shaders)
3DS Files - Video Archive (CGFX_05h - CCAM Cameras)
3DS Files - Video Archive (CGFX_06h - CFLT/CHLT/CALT Lights)
3DS Files - Video Archive (CGFX_08h - CENV Environments)
3DS Files - Video Archive (CGFX_09h,0Ah,0Dh - CANM Animations)
3DS Files - Video Archive (CGFX_0Eh,0Fh - PEMT Emitters/Particles)
Unknown CGFX Sections
These do reportedly exist... somewhere? Unknown which files do actually have such sections.
- 3DS Files - Video Archive (CGFX_03h - ???? Materials)
- 3DS Files - Video Archive (CGFX_07h - CFOG? Fogs)
- 3DS Files - Video Archive (CGFX_0Bh - ???? Visibility animations)
- 3DS Files - Video Archive (CGFX_0Ch - ???? Camera animations)
The Materials are all-unknown. The Fogs are reportedly called CFOG, but anything else is unknown. The two animation types might use CANM format like the other three animation types, but that's just guessed.
Skeleton data (uh, what? where?)
Each entry is E0h bytes in length and organized this way:

      00h 4     Offset (self relative) to name symbol
      04h 4     ?
      08h 4     Joint ID
      0Ch 4     Parent joint ID
      10h 4     Signed offset (self-relative) to parent joint
      14h 18h   unknown/unspecified
      2Ch 0Ch   Angle vector (floats, x, y, z)
      38h 0Ch   Position vector (floats, x, y, z)
      44h 30h   Transformation matrix (4x3)
      74h 30h   Identity matrix ? (4x3)
      A4h 1Ch   unknown/unspecified

Each entry stores the joint transformation data twice; once as angle/position vectors and once as a transformation matrix. Each entry also stores a second matrix which appears to always be identity(?)
Tools

      Every File Explorer
      Ohana3DS and its forks
      SPICA

Links
Another CGFX Format Description (Archived Page):
http://florian.nouwt.com/wiki/index.php/CGFX_(File_Format)

       https://web.archive.org/web/20150511211029/http://florian.nouwt.com
      /wiki/index.php/CGFX_(File_Format)

3DS Files - Video Archive (CGFX Header, Blocks, DICTs)

CGFX Header

      000h 4     ID "CGFX"
      004h 2     Byte Order (FEFFh)
      006h 2     CGFX header size (14h)
      008h 4     Revision (can be 05000000h) (or 01000000h=Old, incompatible)
      00Ch 4     Total Filesize (bytes)
      010h 4     Number of blocks (usually 1=DATA, or 2=DATA+IMAG)
      ...  ..    DATA Block (DICT's, CMDL/TXOB/etc., and DICT Symbols)
      ...  ..    IMAG Block (optional, eg. for TXOB bitmaps)

The DATA block contains various small data structures. It's more or less required to load the whole DATA block to memory when parsing those structs.
The IMAG block isn't required in memory (or, when needed, one may want to store its content directly in VRAM).
DATA Block (for CGFX Version 05000000h)

      000h      4     ID "DATA"
      004h      4     DATA Block Size (including DICT,CMDL,etc.)
      008h      4+4   DICT 00h for CMDL  Models                (NumEntries, Offset)
      010h      4+4   DICT 01h for TXOB  Textures              (NumEntries, Offset)
      018h      4+4   DICT 02h for LUTS  Look-up tables?       (NumEntries, Offset)
      020h      4+4   DICT 03h for ?     Materials             (NumEntries, Offset)
      028h      4+4   DICT 04h for SHDR  Shaders (+DVLB)       (NumEntries, Offset)
      030h      4+4   DICT 05h for CCAM  Cameras               (NumEntries, Offset)
      038h      4+4   DICT 06h for CFLT/CHLT/CALT Lights       (NumEntries, Offset)
      040h      4+4   DICT 07h for CFOG? Fogs                  (NumEntries, Offset)
      048h      4+4   DICT 08h for CENV  Environments          (NumEntries, Offset)
      050h      4+4   DICT 09h for CANM  Skeleton animations   (NumEntries, Offset)
      058h      4+4   DICT 0Ah for CANM  Texture animations    (NumEntries, Offset)
      060h      4+4   DICT 0Bh for ?     Visibility animations (NumEntries, Offset)
      068h      4+4   DICT 0Ch for ?     Camera animations     (NumEntries, Offset)
      070h      4+4   DICT 0Dh for CANM  Light animations      (NumEntries, Offset)
      078h      4+4   DICT 0Eh for PEMT  Emitters              (NumEntries, Offset)
     Below entry doesn't exist in all files (ie. abort here if [80h]="DICT").
     (080h)     4+4   DICT 0Fh for PEMT  Particles             (NumEntries, Offset)
      ...       ..    DICT's and CMDL/TXOB/etc. and Symbols...

The above Offsets are self-relative pointers to the corresponding DICT.
Unused DICTs have NumEntries=0 and Offset=0 (ie. the Offset doesn't point anywhere in that case).
IMAG Block (if present)

      000h       4     ID "IMAG"
      004h       4     IMAG Block Size
      008h       ...   Data (eg. texture bitmaps, referenced from TXOB's)

DATA Block (for CGFX Version 01000000h)
3DS Activity Log does have some old CGFX file in RomFS:\simple.bcmdl, its the data block lacks the "DATA" ID and Block Size, and the DICT's merely have Offsets (without NumEntries).

      000h      4*9   DICT's (nine Offsets)

The CMDL/MTOB/etc. blocks in that file are probably also incompatible with newer CGFX files?
DICT - Directory with Symbol/Offset for each file

      000h 4     ID "DICT"
      004h 4     DICT size (1Ch+N*10h)
      008h 4     Number of entries (same as NumEntries in DATA's DICT list)
      00Ch 10h   DICT entry 0    (Patricia Tree Root entry)
      01Ch 10h*N DICT entry 1..N (Patricia Tree and actual Symbols/Offsets)

Patricia Tree Root entry:

      000h 4     Patricia Tree First Bit-number (always FFFFFFFFh=dummy/last)
      002h 2     Patricia Tree First entry (1..N) (usually points to rightmost bit)
      004h 0Ah   Patricia Tree Unused (zerofilled)

DICT entry 1..N format:

      000h 4     Patricia Tree Bit-number to be tested (0=Bit0 of 1st char) ?
      004h 2     Patricia Tree Next entry when test=0 ?
      006h 2     Patricia Tree Next entry when test=1 ?
      008h 4     Offset to symbol (self-relative) --> ASCII name
      00Ch 4     Offset to object (self-relative) --> flags followed by "CMDL" etc?

The Patricia Tree is intended for searching Symbols by testing a few bits (without comparing all characters). The tree does somewhat unforunately start with the highest bit in rightmost character (so the search string must be assumed to be zeropadded). Unknown when the final entry is reached... when the bit-test number is same/bigger than previous bit-test?
Note on DICT names: There can be several root entries with same name (eg. 3DS Download Play ExeFS:\banner has name "COMMON" used for CFGX_00h and CFGX_09h and CFGX_0Ah root entries).

3DS Files - Video Archive (CGFX_00h - CMDL Models)

CMDL is found in most CGFX files.
CMDL - 3D Model

      000h 4     Flags (bit7: hasSkeletonSobj) (eg. 40000092h)
      004h 4     ID "CMDL"
      008h 4     Revision? (07000000h)
      00Ch 4     Name Offset (self-relative, same name as in parent DICT)
      010h 4     Unknown (0)
      014h 4     Unknown (0)
      018h 4     Unknown (1)
      01Ch 4     Unknown (1)
      020h 4     Unknown (0)
      024h 4     Unknown (0)
      028h 4+4   DICT for Animation Types                    (NumEntries, Offset)
      030h 0Ch   Scale        (3 float32: x, y, z) ;-usually (1,1,1)
      03Ch 0Ch   Rotation     (3 float32)          ;-usually (0,0,0)
      048h 0Ch   Translation  (3 float32)          ;-usually (0,0,0)
      054h 30h   Local Matrix (4x3 float32)        ;-usually unit matrix
      084h 30h   World Matrix (4x3 float32)        ;-usually unit matrix
      0B4h 4+4   Vertex Info SOBJ List (Meshes)              (NumEntries, Offset)
      0BCh 4+4   DICT for MTOB         (Materials)           (NumEntries, Offset)
      0C4h 4+4   Vertex Info SOBJ List (Shapes)              (NumEntries, Offset)
      0CCh 4+4   DICT for Unknown      (Mesh Nodes)          (NumEntries, Offset)
      0D4h 4     Unknown (1)
      0D8h 4     Unknown (0)
      0DCh 4     Unknown (0)
      0E0h 4     Skeleton Info SOBJ offset (self-relative) (present if flag bit7=1)

A CMDL section refers to outside data; it can not be considered separately from the rest of the CGFX file. The second DICT in the CMDL section contains offsets to MTOB objects.
SOBJ List, at CMDL([B8h]+B8h)

      00h 4*N   Vertex Info SOBJ self-relative offset list

MTOB - Materials - some kind of Texture Info, linked to TXOB

      000h 4     Flags (eg. 08000000h)
      004h 4     ID "MTOB"
      008h 4     Revision (06000000h)
      00Ch 4     Name Offset (self-relative, same name as in parent DICT)
      010h 4+4   Unknown (0,0)
      018h 4+4   Unknown (0,0)
      020h 4     Unknown (1)
      024h 4+4   Unknown (0,0)
      02Ch 4+4   Unknown (0,0)
      034h ...   Vectors/Matrices? (lots of float32's)
      0D8h ..    Unknown (00FFFFFFh, FFFFFFFFh, FFFFFFFFh, 00000000h)
      0E8h ..    Unknown (FFF2FFFFh, FF99CCCCh, FF000000h, FF000000h)
      0F8h ..    Unknown (FF000000h, FF000000h, 00000000h, 00000000h)
      108h 4     Unknown (3)
      ...  ...   ?
      ..   ..

Then somewhere inside/after MTOB comes something called TXOB with 40h-byte size and SHDR (which are probably something else than the TXOB's and SHDR's in the CGFX's "root directory") (though they might be meant to <refer> to those root entries).

      000h 4     Flags (eg. 20000004h)
      004h 4     ID "TXOB"
      008h 4     Revision (05000000h)
      00Ch 4     Name Offset (self-relative) (eg. points to empty string)
      010h 4+4   Unknown (0,0)
      018h 4     Name Offset (self-relative) (eg. points to "COMMON3",0)
      01Ch 4+4   Unknown (0,0)
      024h 4     Unknown (FFFFFF90h)
      028h 4     Unknown (1)
      02Ch 4+4+4 Unknown (0,0,0)
      038h 4     Unknown (3F800000h) (float32)
      03Ch 4     Unknown (0)
      -------------------------                                 ;\somehere is
      040h 4     Unknown (1)  or Flags for below shader stuff?  ; probably begin
      - - - - - - - -----------                                 ;/of shader struct?
      044h 4     ID "SHDR"
      048h 4     Revision (05000000h)
      04Ch 4     Name Offset (self-relative) (eg. points to ... what?)
      050h 4+4   Unknown (0,0)
      058h 4     Name Offset (self-relative) (eg. points to ... what?)
      05Ch 4     Unknown ?
      ...  ...   ?
      ..   ..

SOBJ
SOBJ structures can be used to describe 3D objects that are part of the model. If such is the case then they will follow this structure:

      000h 4     Flags (bit4: model, bit1: skeleton)
      004h 4     ID "SOBJ"
      008h 4     ?
      00Ch 4     Unknown symbol offset (self-relative)
      010h 0Ch   ?
      01Ch 4     Offset (self-relative) to Unknown1 (array of floats?)
      020h 0Ch   Mesh position vector (X/Y/Z floats)
      02Ch 4+4   Face Group List    (NumEntries, Offset) (list contains offsets)
      034h 4     ?
      038h 4+4   Vertex Group List  (NumEntries, Offset) (list contains offsets)
      040h 4     Unknown offset (self-relative) ?

Face groups:

      000h 4+4   Bone Group ID List (NumEntries, Offset) (list contains 32bit IDs)
      008h 4     ?
      00Ch 4+4   Unknown2 List      (NumEntries, Offset) (list contains offsets)

Unknown2:

      000h 4+4   Face Group Descriptor List (NumEntries, Offset) (contains offsets)
      008h 4+4   Unknown3 List              (NumEntries, Offset) (contains 32bit's)
      010h 8     ?

Face array descriptor:

      000h 4     Flags (bit 1: vertex index format: 0=byte, 1=short)
      004h 4     ?
      008h 4+4   Vertex Index Array (SizeInBytes, Offset)

Vertex groups come in a number of different formats. Typically the first vertex group entry is of format 40000002h and contains the actual vertex array.
Vertex group format 40000002h:

      000h 4     Flags (40000002h)
      004h 4     ?
      008h 4     ?
      00Ch 4     ?
      010h 4     ?
      014h 4+4   Vertex Array       (SizeInBytes, Offset)
      01Ch 4     ?
      020h 4     ?
      024h 4     Vertex stride/size in bytes (see below)
      028h 4     Unknown3 count
      02Ch 4     Offset (self-relative) to component declaration offset array

Each mesh's primary vertex group contains an array of vertex component declaration objects, defining the order and parameters for each of a vertex's components.
Vertex component declaration:

      000h 4     Flags (40000001h)
      004h 4     Vertex component type (see below)
      008h 4     ?
      00Ch 4     ?
      010h 4     ?
      014h 4     ?
      018h 4     ?
      01Ch 4     ?
      020h 4     ?
      024h 1     Vertex component data type (see below)
      025h 1     ?
      026h 1     ?
      027h 1     ?
      028h 4     Number of values in this component (eg. XYZ=3, UV=2)
      02Ch 4     Multiplier for this component's values (float)
      030h 4     Position of this component within vertex stride

Vertex formats with bone data support multiple bone assignment. In this case, the sum of all bone weights is 64h.

     Vertex component types:
      00h=Position
      01h=Normal
      02h=? (unobserved)
      03h=Color
      04h=UV0
      05h=UV1
      06h=? (unobserved, possibly UV2)
      07h=Weight
      08h=Index
     Vertex component data types:
      00h=sbyte
      01h=byte
      02h=short
      03h=? (unobserved, possibly ushort)
      04h=? (unobserved, possibly int)
      05h=? (unobserved, possibly uint)
      06h=float

Vertex components are stored as one of the above data types, and the vertex component declaration contains a multiplier that adapts the values to the float version which the game will use. For example, color RGBA values are stored as bytes, and the multiplier converts them from 0-255 to 0-1.0, and position components using short values are normalized via the multiplier to take advantage of the entire short value range.

3DS Files - Video Archive (CGFX_01h - TXOB Textures)

TXOB is found in most CGFX files.
TXOB - Texture Objects?
TXOBs are contained within MTOBs. They can describe textures; if such is the case, then their structure is as follows:

     Can be 40h-byte or 5Ch-byte size?
     3dbrew messed blurb claims 4Ch-bytes (with overlapping entries)?
     Or are the 40h-byte ones sub-items in MTOB?
     And only the 5Ch-byte ones are actually DICT 01h entries?
      000h 4     Flags (eg. 20000004h=40h-byte, or 20000011h=5Ch-byte)
      004h 4     ID "TXOB"
      008h 4     Revision? (05000000h)
      00Ch 4     Offset (self-relative) to symbol
      010h 4     Unknown (0)
      014h 4     Unknown (0)
      018h 4     Texture height (eg. 40h)
      01Ch 4     Texture width  (eg. 10h)
      020h 4     Unknown (?)    (eg. 6758h, 6756h, 6758h)  ;\flags maybe?
      024h 4     Unknown (?)    (eg. 6760h, 6761h, 1401h)  ;/or handle/ID/index?
      028h 4     Mipmap levels  (eg. 1)
      02Ch 4     Unknown (0)
      030h 4     Unknown (0)
      034h 4     Texture format (eg. 5) (see below)
      038h 4     Unknown (?)    (eg. 4)
      03Ch 4     Texture height (eg. 40h)  ;\same as in [18h,1Ch] ?
      040h 4     Texture width  (eg. 10h)  ;/
      044h 4     Texture data size (eg. 800h) (width*height*bytes_per_pixel)
      048h 4     Texture data offset (self-relative) (eg. 1A070h) (that's in IMAG)
      04Ch 4     Unknown (0)
      050h 4     Unknown (?)       (eg. 10h)
      054h 4     Unknown (0)
      058h 4?    Unknown (0)

Texture format:

      00h=RGBA8
      01h=RGB8
      02h=RGBA5551
      03h=RGB565
      04h=RGBA4
      05h=LA8
      06h=HILO8
      07h=L8
      08h=A8
      09h=LA4
      0Ah=L4
      0Bh=A4 ?
      0Ch=ETC1 (see notes below)
      0Dh=ETC1A4 ?

Every texture format has its texture data divided into 8x8 tiles. See SMDH for more information. ETC1 is a compressed texture format which compresses blocks of 4x4 pixels into u64s. These u64 are traditionally stored in big endian; however, nintendo's implementation stores them in little endian. ETC1 textures are stored in 8x8 tiles; decompressed 4x4 therefore have to be organized accordingly. See [1] for implementation example.

3DS Files - Video Archive (CGFX_02h - LUTS Look-up Tables)

LUTS is found in some CGFX files (eg. 3DS System Settings ExeFS:\banner).
LUTS - lookup table(s?) (possibly for use with shaders?)

      000h 4     Flags (eg. 04000000h)
      004h 4     ID "LUTS"
      008h 4     Revision (04000000h)
      00Ch 4     Name Offset
      010h 4+4   Unknown (0,0)
      018h 4+4   DICT for ... appears to describe material specularity? (Num,Offs)

3DS Files - Video Archive (CGFX_04h - SHDR Shaders)

SHDR is found some CGFX files, for example,

      3DS eShop RomFS:\shader contains one CGFX (and several raw DVLBs files)
      3DS Sound RomDS:\res\GfxShader.LZ contains two SHDR's in a single GGFX

SHDR - Shader (contains a regular DVLB file, with some extra parameters)

      000h 4     Flags (eg. 80000002h)
      004h 4     ID "SHDR"
      008h 4     Revision (05000000h)
      00Ch 4     Name Offset (self-relative) (same as in parent DICT)
      010h 4+4   Unknown (0,0)
      018h 4     Shader Size (eg. 26A4h)              ;\Shader in DVLB file format
      01Ch 4     Shader Offset (self-relative) (28h)  ;/
      020h 4     Unknown (04h)       ;number of below words (eg. 4)              ;\
      024h 4     Unknown (eg. 26C4h) ;ptr to 4 words (8B31h,8B31h,8B31h,8B31h)   ;/
      028h 4     Unknown (04h)       ;number of below words (eg. 4)              ;\
      02Ch 4     Unknown (eg. 26CCh) ;ptr to 4 words (20h,A4h,128h,1ACh) ;Offsets;/
      030h 4     Unknown (04h)       ;number of below words (eg. 4)              ;\
      034h 4     Unknown (eg. 26D4h) ;ptr to 4 words (0,0,0,0)                   ;/
      038h 4     Unknown (0)
      03Ch 4     Unknown (0)
      040h 4     Unknown (0)

Unknown what the three lists at [20h..37h] are doing, and unknown what is at the offset of the second list.
For the DVLB file format, see
3DS Files - Video Shaders (DVLB and DVOB Format)

3DS Files - Video Archive (CGFX_05h - CCAM Cameras)

CCAM is found in some CGFX files (eg. 3DS Sound RomFS:\res\S.pack).
CCAM Format

      000h 4     Flags (eg. 4000000Ah)
      004h 4     ID "CCAM"
      008h 4     Revision (07000000h)
      00Ch 4     Name Offset (self-relative) (same as in parent DICT)
      010h 4+4   Unknown (0,0)
      018h 4+4   Unknown (1,1)
      020h 4+4   Unknown (0,0)
      028h 4+4   DICT for Camera Animation  (NumEntries,Offset)
      030h 0Ch   Vector? (3xFloat32) (1.0, 1.0, 1.0)
      ...  ..    More Vectors and/or Matrices ?
      0BCh 4     Unknown (1D4h)
      0C0h 4     Unknown (1E8h)
      0C4h 4     Unknown (0)

Camera Animation (from DICT in CCAM) (eg. Name=CameraAnimation)

      000h 4     Unknown (80000000h)
      004h 4     Unknown (0)
      008h 4     Name Offset (self-relative) (same as in parent DICT)
      00Ch 4     Unknown (5)
      010h 4+4   DICT for whatever (NumEntries,Offset)
      018h 4     Unknown (3)
      01Ch 4     Unknown (8)
      020h 4     Unknown (0)
      024h 4     Unknown (8)
      028h 4     Unknown (6)
      02Ch 4     Unknown (2)

The DICT can have several entries (with names ProjectionUpdater.AspectRatio, ProjectionUpdater.Far, ProjectionUpdater.Fovy, ProjectionUpdater.Near, Transform, ViewUpdater.TargetPosition, ViewUpdater.Twist). The format(s) of that entries are unknown.

3DS Files - Video Archive (CGFX_06h - CFLT/CHLT/CALT Lights)

CFLT (Directional/Fragment Lights) is found in some CGFX files, eg. 3DS System Settings banner
CHLT (Hemisphere Lights) is less common, but found in StreetPass Mii Plaza RomFS:\graphics\model\figure_Galaxy2.lz77 and figure_Link.lz77
CALT (Ambient? Lights) is even less common, found in StreetPass Mii Plaza RomFS:\graphics\model\figure_Pikmin.lz77 and figure_Samus.lz77
CFLT Format

      000h 4     Flags (eg. 400000A2h)
      004h 4     ID "CFLT"
      008h 4     Revision (06000000h)
      00Ch 4     Name Offset (self-relative) (same as in parent DICT)
      010h 4+4   Unknown (0,0)
      018h 4+4   Unknown (1,1)
      020h 4+4   Unknown (0,0)
      028h 4+4   DICT for Light Animation (NumEntries,Offset)
      030h 0Ch   Vector? (3xFloat32) (1.0, 1.0, 1.0)
      03Ch 0Ch   Vector? (3xFloat32) (0.0, 0.0, 0.0)
      048h 0Ch   Vector? (3xFloat32) (0.0, 0.0, 0.0)
      054h 30h   Matrix? (4x3xFloat32) (Identity)
      084h 30h   Matrix? (4x3xFloat32) (Identity)
      0B4h 4     Unknown (1)
      0B8h 10h   Unknown (zeroes)
      0BCh 40h   Float32's (all 1.0)
      0FCh 10h   Unknown (FF000000h, FFFFFFFFh, FFFFFFFFh, FFFFFFFFh)
      10Ch 0Ch   Vector? (3xFloat32?) (3F13CD3Ah, 3F13CD3Ah, BF13CD3Ah)
      118h 0Ch   Vector? (3xFloat32?) (00000000h, 00000000h, 00000000h)
      124h 0Ch   Vector? (3xFloat32?) (3F800000h, 0003F000h, 00080000h)
      130h 4     Unknown (1)

Some of the Vectors might be X,Y,Z vectors. Some might be R,G,B colors?
Light Animation (from DICT in CFLT) (eg. Name=LightAnimation)

      000h 4     Unknown (80000000h)
      004h 4     Unknown (0)
      008h 4     Name Offset (self-relative) (same as in parent DICT)
      00Ch 4     Unknown (4)
      010h 4+4   DICT for whatever (NumEntries,Offset)
      018h 4     Unknown (5)
      01Ch 4     Unknown (8)
      020h 4     Unknown (0)
      024h 4     Unknown (0)
      028h 4     Unknown (3)
      02Ch 4     Unknown (6)
      030h 4     Unknown (2)
      034h 4     Unknown (0)

The DICT can have several entries (with names Ambient, Diffuse, Direction, DistanceAttentuationEnd, DistanceAttentuationStart, IsLightEnabled, Specular0, Specular1, Transform). The formats of those entries are unknown (the entries seem to use different formats, eg. IsLightEnabled is 8 bytes).
CHLT Format
CALT Format
Unknown. Seems to be similar as CFLT (but, in case of CALT, with less Light Animation DICT entries).

3DS Files - Video Archive (CGFX_08h - CENV Environments)

CENV is found in some CGFX files, eg. 3DS System Settings ExeFS:\banner (with Unknown2) or Mii Maker ExeFS:\banner (with Unknown1, Unknown2, Unknown3)
CENV Format

      000h 4     Flags (eg. 00800000h)
      004h 4     ID "CENV"
      008h 4     Revision (01000000h)
      00Ch 4     Name Offset (self-relative) (same as in parent DICT)
      010h 4+4   Unknown0 (0,0)
      018h 4+4   Unknown1 (0,0)    (or 1,14h)     ;(Num,Offset ?)
      020h 4+4   Unknown2 (1,0Ch)  (or 2,10h)     ;(Num,Offset ?)
      028h 4+4   Unknown3 (0,0)    (or 1,10h)     ;(Num,Offset ?)
      ...  4*n1  Offset List for Unknown1 ?
      ...  4*n2  Offset List for Unknown2 ?
      ...  4*n3  Offset List for Unknown3 ?

Entries for Unknown1 (if any):

      000h 4     Unknown (0)
      004h 4     Corresponding name? (eg. Offset to "FragmentOperation")
      008h 4     Unknown (0)
      00Ch 4     Unknown (0)

Entries for Unknown2:

      000h 4     Unknown (1)
      004h 4     Unknown (4)
      008h 4     Unknown (4)
      00Ch 4     Unknown (0)
      010h 4     Corresponding Light name?  (eg. Offset to Name "Light1")
      014h 4     Unknown (0)

Entries for Unknown3 (if any):

      ...  ..    ?

3DS Files - Video Archive (CGFX_09h,0Ah,0Dh - CANM Animations)

- 3DS Files - Video Archive (CGFX_09h - CANM Skeleton animations)
- 3DS Files - Video Archive (CGFX_0Ah - CANM Texture animations)
- 3DS Files - Video Archive (CGFX_0Dh - CANM Light animations)
CANM skeleton is found in some CGFX files, 3DS System Settings ExeFS:\banner
CANM texture is found in some CGFX files, eg. 3DS Download Play ExeFS:\banner
CANM light is found in some CGFX files, eg. 3DS Camera RomFS:\res\P_Finder_U
All of those types do begin with ID "CANM", but unknown if they are actually using the same data structure(s).
CANM (for Skeleton Animations, and Texture Animations)

      N/A  -     There is no leading Flags entry,
      000h 4     ID "CANM"
      004h 4     Revision (05000000h)
      008h 4     Name Offset (self-relative) eg. COMMON (same as in parent DICT)
      00Ch 4     Name Offset (self-relative) eg. SkeletalAnimation
      010h 4     Unknown (1)
      014h 4     Unknown (44160000h) (float32 maybe?)
      018h 4+4   DICT for ... whatever (NumEntries,Offset)  (Offset=0Ch)
      020h 4+4   Unknown (0,0)

Note: In the above example, the name "COMMON" is used for both CFGX_00h and CFGX_09h and CFGX_0Ah root entries.
The DICT in the CANM block(s) can contain items with various names, the format(s) of that items are unknown.

3DS Files - Video Archive (CGFX_0Eh,0Fh - PEMT Emitters/Particles)

- 3DS Files - Video Archive (CGFX_0Eh - PEMT Emitters)
- 3DS Files - Video Archive (CGFX_0Fh - PEMT Particles)
PEMT emitters is found in some CGFX files, eg. Mii Maker RomFS:\effects\..
PEMT particles is found in some CGFX files, eg. 3DS Camera RomFS:\effect\P.pack
PEMT Format (as for CGFX_0Fh Particles) (unknown if CGFX_0Eh is same/similar)

      000h 4     Flags (eg. 40000006h)
      004h 4     ID "PEMT"
      008h 4     Revision (05000000h)
      00Ch 4     Name Offset (self-relative) (same as in parent DICT)
      010h 4+4   Unknown (0,0)
      018h 4+4   Unknown (1,1)
      020h ...   Several zeroes and float32's ...?
      0B8h 4     Name Offset (self-relative) (whatever name?)
      0BCh 4     Unknown (24h)                      (Offset?)
      0C0h 4     Unknown (0)
      0C4h 4     Unknown (3F800000h) (or 40000000h) (float32?)
      0C8h 4     Unknown (0)         (or 3DCCCCCDh)
      0CCh 4     Unknown (0Ah)       (or 13Dh)
      0D0h 4     Unknown (0)         (or 0)
      0D4h 4     Unknown (1)         (or 0)
      0D8h 4     Unknown (168h)      (or 3)
      0DCh 4     Unknown (0)         (or 4)

Then there comes some more stuff at offset 0E0h (which might be addressed via Offset 24h stored at [0BCh] in above structure?). That extra data can somehow vary randomly with/without DICT at different locations (it seems to be related on "Flags" in first which can be 04000000h, 10000000h, 20000000h, 40000000h, 80000000h, although there are two variants for Flags=20000000h).
Unknown how that makes sense... maybe some of the below stuff is totally unrelated to PEMT (ie. it might be referenced from somewhere else, and just happens to be located after PEMT).
3DS Camera RomFS:\effect\P.pack\ScoreE.bcptlLZ has three variants with DICT (all in one file).
Variant with DICT and Flags=20000000h

      000h 4     Flags? (20000000h)
      004h 4     Unknown (0)
      008h 4     Unknown (3F000000h)
      ...  ..    Floats and/or whatever
      02Ch 4     Name Offset (self-relative) (whatever name?)
      030h 4     Unknown (3)         (or 2)
      034h 4+4   DICT for ... whatever (NumEntries,Offset)
      03Ch 4+4   Unknown (1,8)       (or 4,8)     (Num,Offset?)  ----.
      044h 4     Unknown (0)         (or 1)                          |
      048h ..    Unknown (0)         (or 3,7,5,2)              <-----'

Variant with DICT and Flags=40000000h

      000h 4     Flags? (40000000h)
      004h 4     Unknown (0)
      008h 4     Unknown (3Fxxxxxxh)                        ;\one extra word here?
      ...  ..    Floats and/or whatever                     ;/
      030h 4     Name Offset (self-relative) (whatever name?)
      034h 4     Unknown (3)
      038h 4+4   DICT for ... whatever (NumEntries,Offset)
      040h 4+4   Unknown (1,8)                    (Num,Offset?)  ----.
      048h 4     Unknown (0)                                         |
      04Ch ..    Unknown (0)                                   <-----'

Variant with DICT and Flags=10000000h

      000h 4     Flags? (10000000h)
      004h 4     Unknown (0)                                ;\no floats here
      008h 4     Unknown (80000000h)                        ; (or only a few)
      00Ch 4     Unknown (0)                                ;/
      010h 4     Name Offset (self-relative) (whatever name?)
      014h 4     Unknown (3)
      018h 4+4   DICT for ... whatever (NumEntries,Offset)
      020h 4+4   Unknown (1,8)                    (Num,Offset?)  ----.
      028h 4     Unknown (0)                                         |
      02Ch ..    Unknown (0)                                   <-----'

Then comes the DICT (unless type is 04000000h)... the DICT is containing whatever... it can have MANY entries, in unknown format(s).
Variant without DICT and Flags=04000000h
As found in Mii Maker RomFS:\effect\..\QR00.bcptl

      000h 4     Unknown (04000000h)
      004h 4     Unknown (0)             ;has only some floats, no DICT...
      008h 1Ch   Floats and/or whatever
      024h 2     Uhm, two zero bytes? (then followed by Symbol table)

Variant without DICT and Flags=20000000h (despite same Flags can have DICT)
And Mii Maker also has some file with yet smaller DICT-less block, but with 20000000h (which usuallly DOES have DICT, but not in this case).

      000h 4     Unknown (20000000h)
      004h 4     Unknown (0)             ;has only some floats, no DICT...
      008h 18h   Floats and/or whatever
      020h 2     Uhm, bytes 00h, 01h? (then followed by Symbol table)

Variant without DICT and Flags=80000000h
And, AR Games RomFS:\i_ar\effect\Ef_drawing.lz77

      000h 4     Unknown (80000000h)
      004h 4     Unknown (0)             ;has only some floats, no DICT...
      008h 10h   Floats and/or whatever
      018h 4     Unknown (0)

Some of the DICT-less variants seem to contain two bytes (rather than a whole 32bit word) in last entry? Usually that's padded to 32bit alignment, but not in the last entry (which occurs right before the string table, which can start at a non-aligned location).

3DS Files - Video Shaders (DVLB and DVOB Format)

There are two shader file formats:

      DVLB - Vertex Shader Library (can contain one or more shaders) (common/used)
      DVOB - Vertex Shader Object  (single shader) (unknown if/where that's used?)

Shaders are usually stored in folder RomFS:\shaders, with extensions

      .shbin  Shader Binary in DVLB format (most common)
      .??     Shader Binary in DVOB format (unknown if/where that's used?)
      .bcsdr  Shader Binary in DVLB format stored inside of a CGFX container
      .csdr   ASCII, with shader binary(ies?) encoded in BASE64  (eg. in AR Games)

DVLB Format (Vertex Shader Library) (can contain one or more shaders)

      000h 4    ID "DVLB" (Vertex Shader Library)
      004h 4    N = number of DVLEs in SHBIN
      008h 4*N  DVLE offset table (offsets to start of the DVLB(???) sections)

There is one DVLP block, containing the binary opcode/opdesc data for all shaders (located right after the above header, ie. at offset 008h+4*N).

      000h 4    ID "DVLP" (Vertex Shader Library Program Opcodes/Opdescs)
      004h 2    Type/Version?                (can be 0C02h)
      006h 2    Unknown                      (can be 0000h)
      008h 4    Opcode Table Offset          (from DVLP start) (28h)
      00Ch 4    Opcode Table Size            (in 4-byte units)
      010h 4    Opdesc Table Offset          (from DVLP start)
      014h 4    Opdesc Table Size            (in 8-byte units)
      018h 4    Line Number Table Offset ?   (from DVLP start)
      01Ch 4    Line Number Table Size   ?   (usually zero)
      020h 4    Filename Symbol Table Offset (from DVLP start)
      024h 4    Filename Symbol Table Size   (in 1-byte units)
      028h ..   Data for above Opcodes, Opdescs, etc.

There can be one or more DVLE blocks, with information about entrypoint and parameters for each shader (located at Header[008h+index*4]).

      000h 4    ID "DVLE" (Vertex Shader Library Function Entrypoints/Params)
      004h 2    Type/Version?                (can be 0C02h)
      006h 1    Shader type (0=Vertex shader, 1=Geometry shader, other=?)
      008h 4    Opcode Entrypoint Address    (in words, in memory) (main)
      00Ch 4    Opcode End Address           (in words, in memory) (endmain)
      010h 4    Unknown                      (can be 001F0001h)
      014h 4    Unknown                      (can be 00000000h)
      018h 4    Constant Table Offset        (relative to DVLE start) (eg. 40h)
      01Ch 4    Constant Table Size          (in 14h-byte units)
      020h 4    Label Table Offset           (relative to DVLE start)
      024h 4    Label Table Size             (in 10h-byte units)
      028h 4    Output Register Table Offset (relative to DVLE start)
      02Ch 4    Output Register Table Size   (in 8-byte units)
      030h 4    Input Register Table Offset  (relative to DVLE start)
      034h 4    Input Register Table Size    (in 8-byte units)
      038h 4    Symbol Table Offset          (relative to DVLE start)
      03Ch 4    Symbol Table Size            (in 1-byte units)
      040h ..   Data for above Constants, Labels, etc.

DVOJ (Single Vertex Shader Function Object)

      000h 4    ID "DVOJ"
      004h 4    Unknown (seems to be related to the DVLE shader type) (uh?)
      008h 4    Unknown
      00Ch 4    Unknown                      (usually FFFFFFFFh)
      010h 4    Constant table Offset        (from DVOJ start)
      014h 4    Constant table Size          (in 14h-byte units)
      018h 4    Label table Offset           (from DVOJ start)
      01Ch 4    Label table Size             (in 10h-byte units)
      020h 4    Opcode Table Offset          (from DVOJ start)
      024h 4    Opcode Table Size            (in 4-byte units)
      028h 4    Opdesc Table Offset          (relative to DVLP??? start)
      02Ch 4    Opdesc Table Size            (in 8-byte units)
      030h 4    Line Number Table Offset ?   (from DVOJ start)
      034h 4    Line Number Table Size   ?   (in 8-byte units)
      038h 4    Relocation Table Offset      (from DVOJ start)
      03Ch 4    Relocation Table Size        (in 0Ch-byte units)
      040h 4    Output register table Offset (from DVOJ start)
      044h 4    Output register table Size   (in 8-byte units)
      048h 4    Input Register table Offset  (from DVOJ start)
      04Ch 4    Input Register table Size    (in 8-byte units)
      050h 4    Symbol table Offset          (from DVOJ start)
      054h 4    Symbol table Size            (in 1-byte units)

Entrypoint/End Address seem to be implied to be begin/end of the opcode area?

     _______________________________ Table Formats ________________________________

Opcode Table (with 4-byte entries)

      000h 4    Shader Opcode

Opdesc Table (with 8-byte entries)

      000h 4    Shader Opdesc (bit31: set to 1 in most (but not all) entries, why?)
      004h 4    Unknown, Flags? (usually 0Fh, 07h, or 03h)

Constant Table (with 14h-byte entries)

     Bool Entries (with 00h in first byte):
      000h 1    Entry Type (Must be 00h for Bool Uniform)
      002h 1    Bool Uniform ID (whatever, maybe register number, 0..0Fh?)
      004h 1    Value (boolean, ie. 00h or 01h ?)
      005h 0Fh  Unused
     Integer Uniform Vector Entries (with 01h in first byte):
      000h 1    Entry Type (Must be 01h for Integer Uniform)
      002h 1    Integer Uniform vector ID (whatever, maybe register number, 0..3?)
      004h 1    x (u8)  ;Loop count-1
      005h 1    y (u8)  ;Loop starting index
      006h 1    z (u8)  ;Loop index step
      007h 1    w (u8)  ;uh, but integer uniforms have only 3 elements... x,y,z?
      008h 0Ch  Unused
     Float Uniform Vector Entries (with 02h in first byte):
      000h 1    Entry Type (Must be 02h for Float Uniform)
      002h 1    Float Uniform vector ID (00h..5Fh = c0..c95)
      004h 4    x (float24)   ;24bit float values (paddded with bit24-31=zero)
      008h 4    y (float24)   ;(weirdly, these 4x24bit must be manually merged
      00Ch 4    z (float24)   ;into 3x32bit before sending them to GPU)
      010h 4    w (float24)

Output Register Table (with 8-byte entries)

      000h 2    Output Type (see below)                    (only lower 4bit used?)
      002h 2    Output Register ID                         (only lower 4bit used?)
      004h 2    Output Attribute Component Mask (eg. 5=xz) (only lower 4bit used?)
      006h 2    Unknown                                    (unknown?)

Output Types:

      00h = result.position
      01h = result.normalquat
      02h = result.color
      03h = result.texcoord0
      04h = result.texcoord0w
      05h = result.texcoord1
      06h = result.texcoord2
      07h = ?
      08h = result.view

Input Register Table (with 8-byte entries)

      000h 4    Input Parameter Name Offset (in Symbol Table) (eg. "vVtxData")
      004h 2    Input Register Index Start (see below)
      006h 2    Input Register Index End   (end=start+num-1)

Input Register Indices:

      00h..0Fh = v0..v15  ;Vertex input registers    (per vertex)
      10h..6Fh = c0..c95  ;Float uniform registers   (per function)
      70h..73h = i0..i3   ;Integer uniform registers (per function)
      78h..87h = b0..b15  ;Bool uniform registers    (per function)

Label Table (with 10h-byte entries)

      000h 1    Label ID (increasing IDs, starting at 00h) (unknown purpose)
      001h 3    Unknown (000100h)
      004h 4    Opcode Address (in words, in memory)
      008h 4    Unknown (FFFFFFFFh)
      00Ch 4    Label Name Offset (in Symbol Table) (eg. "main", and "endmain")

Relocation Table (with 0Ch-byte entries) (exists in DVOB files only)

      000h 4    Opcode Address (in words, in memory) (excluding END, NOP, etc.)
      004h 4    Unknown  ;\probably some kind of opcode/opdesc relocation info?
      008h 4    Unknown  ;/(for merging several DVOB files in shader memory)

Line Number Table (with 8-byte entries, one for each Opcode Table entry)

      000h 4    Source Filename Offset (in Symbol Table) (eg. "font_XxxShader.vsh")
      004h 4    Source Line number? (for the corresponding Opcode Table entry)

Symbol Table (with ASCII strings, each terminated by 00h)
DVLB files have separate Symbol Tables in each DVLP/DVLE chunk:

      Symbols in DVLP chunk:    Source Filenames
      Symbols in DVLE chunk(s): Labels and Names for Input registers

DVOB files have all those symbols in a single Symbol Table.

3DS Files - Video Fonts (CFNT and FFNT Format)

CTR Font Format
.bcfnt files are bitmap fonts made for the 3ds. The system font uses this format too except the header is changed from CFNT to CFNU and all file offsets are changed to absolute in memory offsets.

      CFNT - 3DS Font version 3 file
      CFNU - 3DS Font version 3 stored in memory (System Font)
      FFNT - 3DS Font version 4 file

The format is based on the Nitro Font format for DS/DSi:
DS Cartridge Nitro Font Resource Format
CFNT Header

      000h 4   ID ("CFNT" or "CFNU" or "FFNT")
      004h 2   Byte Order (FEFFh)
      006h 2   Header Size
      008h 4   Version (usually 03000000h) (also so for FFNT ?)
      00Ch 4   File size (the total)
      010h 4   Number of "blocks" to read

Font Info Chunk

      CFNT FFNT Siz Content
      000h 000h 4   ID ("FINF")
      004h 004h 4   Section Size
      008h 008h 1   Font Type
      009h -    1   Line Feed (8bit)
      -    00Ch 2   Line Feed (16bit)
      00Ah 00Eh 2   Alter Char Index (maybe tileno for undefined chars?)
      00Ch 010h 3   Default Width's (3 bytes: Left, Glyph Width, Char Width)
      00Fh 013h 1   Encoding      (1=Unicode?)
      010h 014h 4   TGLP Offset
      014h 018h 4   CWDH Offset
      018h 01Ch 4   CMAP Offset
      01Ch 009h 1   Height
      01Dh 00Ah 1   Width
      01Eh 00Bh 1   Ascent
      01Fh -    1   Reserved

Character Glyph Chunk (Tile Bitmaps)

      CFNT FFNT Siz Content
      000h 000h 4   ID ("TGLP")
      004h 004h 4   Section Size
      008h 008h 1   Cell Width
      009h 009h 1   Cell Height
      00Ah -    1   Baseline Position (8bit)
      -    010h 2   Baseline Position (16bit)
      00Bh 00Bh 1   Max Character Width
      00Ch 00Ch 4   Sheet Size
      010h -    2   Number of Sheets (16bit)
      -    00Ah 1   Number of Sheets (8bit)
      012h 012h 2   Sheet Image Format 0-13: (RGBA8, RGB8, RGBA5551, RGB565, RGBA4,
      014h 014h 2   Number of columns         LA8, HILO8, L8, A8, LA4, L4, A4,
      016h 016h 2   Number of rows            ETC1, ETC1A4)
      018h 018h 2   Sheet Width
      01Ah 01Ah 2   Sheet Height
      01Ch 01Ch 4   Sheet Data Offset

Character Map(s) - Translation Tables for ASCII/JIS/etc to Tile Numbers?

      000h 4   ID ("CMAP")
      004h 4   Section Size
      008h 2   Code Begin
      00Ah 2   Code End
      00Ch 2   Mapping Method (0=Direct, 1=Table, 2=Scan)
      00Eh 2   Reserved?
      010h 4   Next CMAP Offset

Depending on the mapping method the next bytes are read like so:

      Direct: IndexOffset = read uint16
      Table:  IndexTable = read uint16 array (CodeEnd - CodeBegin + 1)
      Scan:   Number of Scan Entries = read uint16 for every scan
                entry: read uint16 & read uint16

Character Width Chunk

      000h 4   ID ("CWDH")
      004h 4   Section Size
      008h 2   Start Index   ;\implies NumEntries = EndIndex-StartIndex+1
      00Ah 2   End Index     ;/
      00Ch 4   Next CWDH Offset
      010h 3*N Char Widths (3 bytes: Left, Glyph Width, Char Width)

Tools
BFFNT Extractor/Creator. Creates PNG files from TGLP atlas data and a JSON manifest.
See also: http://www.3dbrew.org/wiki/System_Font
Truetype Fonts (TTF)
Some 3DS titles are alsu using Truetype fonts:

      3DS System Data Archives 1, web-kit/OSS CROs (RomFS:\font\nintendo.ttf)
      3DS Browser applet (RomFS:\browser\font\nintendo_NTLG-DB_001.ttf)

That fileformat is also used in the Windows operating system:

      used in Windows 3.1 (Windows\System\*.ttf)
      used in Windows 95 (Windows\Fonts\*.ttf)

Fileformat specs can be found at:

      https://docs.microsoft.com/en-us/typography/opentype/spec/

3DS Files - Video Texture Package (CTPK)

CTPK archives can contain one or more texture files. The archive does usually contain filenames with .tga extension (although the bitmaps are raw data, unrelated to the Targa .tga format).
CTPK is used in "3DS AR Games" (RomFS:\i_ar\tex\Tx_fishing.ctpk), and reportedly in 3DS games "Persona Q" and "Persona Q2". Anyways, more common 3DS texture formats seem to be CLIM files, and TXOB's inside of CFGX files.
CTPK Header

      000h 4     ID "CTPK"                                              ;\
      004h 2     Version (0001h)                                        ;
      006h 2     Number of Texture Info Entries                         ;
      008h 4     Texture Data section offset (aka size of header+info)  ; Header
      00Ch 4     Texture Data section size                              ;
      010h 4     Texture Filename CRC32 Table                           ;
      014h 4     Conversion Info section offset                         ;
      018h 8     Padding (0)                                            ;/
      020h N*20h Texture Info Entries                                   ;\
      ...  N*4   Texture Bitmap Sizes (same as [004h] in Info Entries?) ;
      ...  N*var Texture Filename Strings (ASCII, terminated by 00h)    ;
      ...  ..    Padding (0) (to 8-byte boundary)                       ; Info
      ...  N*8   Texture Filename CRC32 Table                           ;
      ...  N*4   Conversion Info Block Entries                          ;
      ...  ...   Padding (0) (to 80h-byte boundary)                     ;/
      ...  N*var Texture Data section (raw bitmaps)                     ;-Data

Texture Info Entries (starting at offset 020h)
Contains Filename, Size, Type, etc. (sorted aphabetically by filename).

      000h 4     Filename Offset
      004h 4     Texture Data Size (eg. 200h,800h,2000h,4000h,8000h?)
      008h 4     Texture Data Offset (relative to Texture Data section offset)
      00Ch 4     Texture Format (is that same/other as in "Conversion Info"?)
      010h 2     Width
      012h 2     Height
      014h 1     Mip Level
      015h 1     Type (0=Cube Map, 1=1D, 2=2D)
      016h 2     Cube Map Related
      018h 4     Bitmap Size Array Offset (relative to this block) (what for??)
      01Ch 4     Unix Timestamp

Texture Filename CRC32 Table
CRC32s on the filenames (sorted by CRC32 values, starting with smallest value).

      000h 4     CRC32 of Filename (excluding trailing 00h)
      004h 4     File Number, index in Texture Info Entries (0..(N-1))

Conversion Info Block Entries (unknown purpose, maybe info on source data?)

      000h 1     Texture Format           (usually 4,5,9,0Dh) (see below)
      001h 1     Unknown                  (usually 1=what?)
      002h 1     Compressed               (usually 1=what?)
      003h 1     ETC1 Related (Quality?)  (usually 3 or 6=what?)

Texture Formats:

      00h=RGBA8888
      01h=RGB888
      02h=RGBA5551
      03h=RGB565
      04h=RGBA4444
      09h=?
      0Ch=ETC1
      0Dh=ETC1 + Alpha

3DS Files - Video Bitmap (BMP)

Windows Bitmap (.bmp)
Windows bitmap used in 3DS Browser applet (RomFS:\browser\page\img\*.bmp)
Adobe variant used in 3DS AR Games (RomFS:\i_ar\tex\stamp*.lz77)

      000h 2   ID "BM" (Windows Bitmap, aka .bmp)
      002h 4   Total Filesize
      006h 4   Reserved (usually 0)
      00Ah 4   Bitmap Pixeldata Offset
      00Eh 4   Size of Header bytes at 0Eh and up (28h=Normal, 38h=Adobe)
      012h 4   Width in pixels (positive)
      016h 4   Height in pixels (pos=Windows/bottom up, neg=Adobe/top down)
      01Ah 2   Number of Bitplanes (always 1)
      01Ch 2   Bits per Pixel (bpp) (usually 1,4,8,16,24,32)
      01Eh 4   Compression Type (usually 0=Uncompressed) (3=custom RGB bitmasks?)
      022h 4   Compressed Bitmap Size (can be Dummy=0 if uncompressed?)
      026h 4   Horizontal resolution (pixels per metre)  ;\eg. 0B12h or 03E8h
      02Ah 4   Vertical resolution (pixels per metre)    ;/
      02Eh 4   Number of colors in palette (or 0=Default 2^bpp) (or 0=None?)
      032h 4   Number of important colors  (or 0=All)
      036h ..  Extra Adobe stuff (if any)
      ...  ..  Palette (if any)
      ...  ..  Bitmap Pixels

3DS Files - BASE64 Encoding

BASE64 is used to encode binary data into 7bit ASCII characters (with 6 bits per char, aka 3 bytes per 4 char), eg. for binary attachments in email messages. The 3DS uses BASE64 in .CSDR shader files, and in 3DS Browser applet .PEM files.
BASE64 Character --> Binary

      "A..Z" --> value 00..25 (00h..19h)
      "a..z" --> value 26..51 (1Ah..33h)
      "0..9" --> value 52..61 (34h..3Dh)
      "+"    --> value 62     (3Eh)
      "/"    --> value 63     (3Fh)
      "="    --> padding to 4-character boundary (if needed, at end of file)
      CR,LF  --> ignored

3DS .CSDR Shader files
Found in 3DS Nintendo Zone, 3DS AR Games, 3DS Face Raiders (RomFS:\shaders\*.csdr).

      <NintendoWareIntermediateFile>
        <GraphicsContentCtr Namespace="" Version="0.7.0">
          <EditData>
            ...
          </EditData>
          <Shaders>
            <ShaderCtr Name="DefaultShader">
              <BinaryData>RFZMQgMAAAAUDgAAZBQ...XplAA==</BinaryData>
              <ShaderKinds>
                ...
              </ShaderKinds>
              <Descriptions>
                ...
              </Descriptions>
            </ShaderCtr>
          </Shaders>
        </GraphicsContentCtr>
      </NintendoWareIntermediateFile>

The .CSDR files uses 0Dh,0Ah for linebreaks, and 09h TAB's to indent lines. The binary data is stored in single long line without linebreaks, terminated "<". The decoded BASE64 data contains a standard "DVLB" 3DS shader file.
3DS Files - Video Shaders (DVLB and DVOB Format)
Unknown if the <Descriptions> or other fields are containing any useful additional data. Unknown if a .CSDR file can contain more than one "DVLB" binary.
3DS Browser Applet, RomFS:\browser\rootca.pem
The file starts wirh a small header/comment:

      #
      # rootca.pem
      #

Then followed by several certificates, each in following format:

      # Issuer:
      #   ...
      #   O=Entrust.net
      #   ...
      # Expire date     : May 25 16:39:40 2019 GMT
      # SHA1 Fingerprint: 99 a6 9b e6 1a fe 88 6b 4d 2b 82 ... 7e 15 39
      -----BEGIN CERTIFICATE-----
      MIIE2DCCBEGgAwIBAgIEN0rSQzANBgkqhkiG9w0BAQUFADCBwzELMAkGA1UEBhMC
      VVMxFDASBgNVBAoTC0VudHJ1c3QubmV0MTswOQYDVQQLEzJ3d3cuZW50cnVzdC5u
      ...
      95K+8cPV1ZVqBLssziY2ZcgxxufuP+NXdYR6Ee9GTxj005i7qIcyunL2POI9n9cd
      2cNgQ4xYDiKWL2KjLB+6rQXvqzJ4h6BUcxm1XAX5Uj5tLUUL9wqT6u0G+bI=
      -----END CERTIFICATE-----

The 3DS Browser .pem file uses 0Ah for linebreaks, and 64 chars per binary line, terminated by "-" in the END CERTIFICATE string. The decoded BASE64 blocks contain standard .DER files.
DSi SD/MMC Firmware Certificate/Keys (DER)
The comments contain a summary of the DER entries (eg. O=OrganizationName).
3DS System Data Archives 1, offline mode, RomFS:\browser\cave.pem
3DS Nintendo Zone, RomFS:\certs\dev.pem
3DS Nintendo Zone, RomFS:\certs\client.key
Contains only a single DER certificate, with 0Dh,0Ah linebreaks (cave.pem), or 0Ah linebreaks (dev.pem), without any "#" comments:

      -----BEGIN CERTIFICATE-----
      MIIEIDCCAwigAwIBAgIBATANBgkqhkiG9w0BAQsFADBtMQswCQYDVQQGEwJVUzET
      MBEGA1UECBMKV2FzaGluZ3RvbjEhMB8GA1UEChMYTmludGVuZG8gb2YgQW1lcmlj
      ...
      MeIurPFOFV/7+3JkZY7cGUBMwqjiou9/9QBHGPvyNhGU34aUoB9vJI164WsMfDXp
      3K7XdX8WCVY0eks4g9LhLrzDmCrdQByABT0TkmhpYykJOQaWVfWzRLJ0qCirZrDQ
      Qfma0w==
      -----END CERTIFICATE-----

The client.key file similar, but marked BEGIN RSA PRIVATE KEY instead of BEGIN CERTIFICATE.

3DS Files - Video 3D Photos (MPO)

The Multi-Picture Object (MPO) format developed by CIPA allows to store multiple images in one file, the 3DS (and other stereoscopic cameras) are using it to store 3D photos (ie. two images, from two different perspectives; that is, basically two JPEGs badged together, with Exif or JFIF headers in each JPEG, and with an additional MPO header in the first JPEG). The official MPO specs can be found here:

      http://www.cipa.jp/std/documents/e/DC-X007_E.pdf

The 3DS Camera files are using MPOs with Exif headers, including some Nintendo specific information in the Exif header.
There also some other MPOs found in 3DS titles (eg. 3DS Nintendo Zone has a MPO with JFIF header, and without Nintendo specific Exif data in RomFS:\www\included_html\boss_page\BOSS_JP\shared_images\top_screen.mpo or 3DS Camera has non-Nintendo Exif header in RomFS:\depug_mpo_\resizable.mpo).
Nintendo's EXIF Data Structure

      ID    Description                   Value
      010Fh Manufacturer                  Nintendo
      0110h Camera                        Nintendo 3DS
      011Ah XResolution                   72:1
      011Bh YResolution                   72:1
      0128h ResolutionUnit                2
      0131h Software                      Depends on the software:
                                            00204 for the Camera (EU)
                                            00227 for the Mii Editor (EU)
                                            00955 for KH3D (EU)
      0132h DateTime                      YYYY:MM:DD HH:mm:SS
      0213h YCbCrPositioning              2
      9000h ExifVersion                   0220
      9003h DateTimeOriginal              YYYY:MM:DD HH:mm:SS
      9004h DateTimeDigitized             YYYY:MM:DD HH:mm:SS
      9101h ComponentsConfiguration       [0x01,0x02,0x03,0x00]
      927Ch MakerNote                     [DATA - 174 bytes] (yet to be understood)
      A000h FlashPixVersion               0100
      A001h ColorSpace                    1
      A002h PixelXDimension               640
      A003h PixelYDimension               480
      5041h InteroperabilityIndex         R98
      5042h ExifInteroperabilityVersion   0100
      1000h InteroperabilityVersion       JPEG Exif Ver 2.2
      501Bh ThumbnailData                 [DATA - 3000+ bytes]
      5023h ThumbnailCompression          6
      502Dh ThumbnailXResolution          72:1
      502Eh ThumbnailYResolution          72:1
      5030h ThumbnailTransferFunction     2
      0201h JPEGInterchangeFormat         682
      0202h JPEGInterchangeFormatLength   3000+
      5091h ChrominanceTable              [DATA - 128 bytes]
      5090h LuminanceTable                [DATA - 128 bytes]
     Nintendo's IFDs (within IFD=927Ch)
      1100h Nintendo Software-specific data
      1101h Nintendo 64-byte Note

IFD=927Ch - Nintendo's EXIF MakerNote Tag
"This still need to be figured out: The MakerNote is made with Tiff Exif information (Big Endian) first 2 bytes are the IFD Count (IFD is a 12 byte tag), Regulary there are 2 IFDs."
IFD=1100h - Nintendo's Software-specific data
Unknown, reportedly "7-Undefined Count Count=1 ? Value : Offset" uh?
IFD=1101h - Nintendo's 64-Byte Note (little endian, unlike the JPEG headers)

      000h 4   ID ("3DS1")
      004h 4   Unknown (can be 1, 2, 4, or 5)
      008h 4   Timestamp (number of seconds since 1st Jan 2000)
      00Ch 4   Padding (0)
      010h 4   Title ID Low ("but without the last two letters" uh?)
      014h 4   Flags
      018h 4   Console ID (unique identifier, unknown where from...?)
      01Ch 12  Padding (0)
      028h 4   3D Parallax "[-52,54]" ;2x float16? or 1x float32 in range -52..+54?
      02Ch 4   Padding (0)
      030h 2   Gender Category??? (1000h=mii, 2000h=man, 4000h=woman)
      032h 2   Filter (unknown meaning)
      034h 12  Padding (0)

3DS Files - Sound Archive (CSAR Format)

CSAR files are usually found in "RomFS:\sound\" folder, with extension ".bcsar" (Binary CTR Sound Archive).
The CSAR archive contains CSEQ, CWSD, CBNK, CWAR files (and optionally CGRP). Whereof, the CWAR file contains CWAV files.
CSAR Header

      000h 4     ID "CSAR"
      004h 2     Byte Order (FEFFh)
      006h 2     Header Size (usually 40h)
      008h 4     Version (usually 02000000h) (02030200h in Miiverse-posting)
      00Ch 4     Total Filesize
      010h 4     Number of Blocks (usually 3 = STRG+INFO+FILE)
      014h 4+4+4 STRG Block (RefID=2000h, Offset from CSAR+0, Size)
      020h 4+4+4 INFO Block (RefID=2001h, Offset from CSAR+0, Size)
      02Ch 4+4+4 FILE Block (RefID=2002h, Offset from CSAR+0, Size)
      038h 8     Padding to 20h-byte boundary (0)

     _________________________________ STRG Block _________________________________

String Block Header

      000h 4     ID "STRG"
      004h 4     STRG Block Size (same as in CSAR header)
      008h 4+4   Filename String List  (RefID=2400h, Offset from STRG+8)
      010h 4+4   Filename Search Tree  (RefID=2401h, Offset from STRG+8)

Filename String List

      000h 4          Number of Filenames   (eg. 40h)
      004h (4+4+4)*N  Filenames (RefID=1F01h, Offset from this Table, Size)
      ...  ..         Filename strings (uppercase ASCII, terminated by 00h)

Filename Search Tree (Patricia Tree)
This is intended for fast file name lookup. For example, if the String List contains only two entries with name "Fuck" and "Funeral", then one could find the desired string with a single bit-test in the 3rd char (to avoid false matches for strings that do not exist in the list, one could do a string compare on the final result).

      000h       4  First Tree index for search (for testing the leftmost char)
      004h       4  Number of Tree entries      (usually NumNames*2-1)
      008h+N*14h 2  Entry Type               (0=Test, 1=Name)
      00Ah+N*14h 2  Bit number to be tested  (0=Bit7 of 1st char) ;\FFh-filled
      00Ch+N*14h 4  Next Tree index when test Result=0?           ; in Name entries
      010h+N*14h 4  Next Tree index when test Result=1?           ;/
      014h+N*14h 4  Name Index in STRG Block  (0..NumNames-1)     ;\FFh-filled
      018h+N*14h 4  Resource ID in INFO Block (NNxxxxxxh)         ;/in Test entries

To view the whole directory, simply ignore the Test entries, and extract the Name+ID pairs from the Name entries.
Resource IDs
The Resource IDs refer to entries in the INFO Block (the upper 8bit indicate a List number, and lower 24bit contain the entry number in that list):

      ID          List        File Types                        Common Name prefix
      01xxxxxxh = Audio List  (CSEQ, CWSD files)                ;name SE,BGM
      02xxxxxxh = Set List    (folders for above Audio entries) ;name WSDSET,SEQSET
      03xxxxxxh = Bank List   (CBNK files)                      ;name BANK
      04xxxxxxh = Player List (...whatever?)                    ;name PLAYER
      05xxxxxxh = Wav Archive (CWAR files)  <-- unless nameless ;name WARC ;or none
      06xxxxxxh = Group List  (CGRP files)  <-- if any          ;name GROUP

Groups exist only in some files. Wav Archives do exist in all files, but they are often completely omitted in the string tree (or have only one of them listed in the string tree).

     _________________________________ INFO Block _________________________________

Info Block Header

      000h 4     ID "INFO"
      004h 4     INFO Block Size (same as in CSAR header)
      008h 4+4   Audio List      (RefID=2100h, Offset relative to INFO+8) CSEQ,CWSD
      010h 4+4   Set List        (RefID=2104h, Offset relative to INFO+8) Folder?
      018h 4+4   Bank List       (RefID=2101h, Offset relative to INFO+8) CBNK
      020h 4+4   WavArchive List (RefID=2103h, Offset relative to INFO+8) CWAR
      028h 4+4   Group List      (RefID=2105h, Offset relative to INFO+8) CGRP
      030h 4+4   Player List     (RefID=2102h, Offset relative to INFO+8) ?
      038h 4+4   File List       (RefID=2106h, Offset relative to INFO+8) Files
      040h 4+4   Final Entry     (RefID=220Bh, Offset relative to INFO+8) ?
      ...  ..    Lists+Entries   (at Offsets from above INFO header)
      ...  14h   Final Entry     (at Offset from above INFO header)
      ...  ..    Padding to 20h-byte boundary (0)

Audio List (RefID=2100h)

      000h 4        Number of List entries
      004h (4+4)*N  Audio Entries (RefID=2200h, Offset from List+0)

Audio Entry (RefID=2200h) (eg. 2Fh entries) (60h bytes per entry)

      000h 4     Index in File List (File CSEQ or CWSD) (eg. 0,0,1,2,2,3,etc.)
                 (above does often use the same file index for 1-4 audio entries)
      004h 4     Sound player Resource ID (040000xxh)
      008h 4     Volume or so (10h,12h,14h,18h,1Ch,1Eh,28h,38h,40h,48h,60h,64h,7Fh)
      00Ch 4+4   Extended entry (RefID=2202h/2203h, Offset=44h, relative to Audio)
      014h 4     Unknown (80020107h)
      018h 4     Name Index in STRG Block (Names SE_xx,JGL_xx,BGM_xx) (0,1,2,etc.)
      01Ch 4     Unknown (0)
      020h 4     Unknown (40h)
      024h 4     Unknown (30h)
      028h 4     Unknown (0 or 1)
      02Ch 4     Unknown (0=norm, or FFFFh,10000000h,01FF0000h,FE000000h,FFE6EE99h)
      030h 4     Unknown (0Fh)
      034h 4     Unknown (3F000000h)
      038h 4     Unknown (1)
      03Ch 4     Unknown (0)
      040h 4     Unknown (0 or 1)

Extended Entry RefID=2202h: (used for CWSD files)

      044h 4     Unknown (0, 1, 2, 3)   ;often same for 1-2 entries
      048h 4     Unknown (1)
      04Ch 4     Unknown (101h)
      050h 4     Unknown (40h)
      054h 4     Unknown (14h)
      058h 4     Unknown (27Fh)
      05Ch 4     Unknown (0)

Extended Entry RefID=2203h: (used for CSEQ files)

      044h 4     Unknown (100h)
      048h 4     Unknown (18h)
      04Ch 4     Unknown (1, 3, 7, 0Fh, 1Fh, 3Fh, or FFFFh)  ;some bitmask?
      050h 4     Unknown (3)
      054h 4     Unknown (3, 30h, 4Ch, 102h, 26Ah, 283h, ..., 3C2h, 3F7h)
      058h 4     Unknown (40h)
      05Ch 4     Number of below 4-byte entries (usually 1, sometimes 2)
      060h 4*N   Resource ID (0300000xh)    ;often same for 1-N entries

Set List (RefID=2104h)

      000h 4        Number of List entries
      004h (4+4)*N  Set Entries (RefID=2204h, Offset from List+0)

Set Entry (RefID=2204h) (eg. 5 entries) (38h bytes per entry)
This seems to have no file assigned, instead it's assigned to Sound Resource IDs (for above Audio Entries), in so far, the Set could be considered being a Folder instead of a File.

      000h 4     First Sound Resource ID in this sequence set (eg. 010000xxh)
      004h 4     Last Sound Resource ID in this sequence set  (eg. 010000xxh)
      008h 4+4   Extended entry (RefID=0100h, Offset=20h, relative to Set Entry+0)
      010h 4+4   Extended entry (RefID=2205h, Offset=28h, relative to Set Entry+0)
                 Extended entry (RefID=0000h, Offs=FFFFFFFFh) ;alternately to 2205h
      018h 4     Unknown (1)
      01Ch 4     Name Index in STRG Block (Names SEQSET_xxx or WSDSET_xxx)

Extended Entry RefID=0100h:

      020h 4     Number of below 4-byte values (usually 1, sometimes 2)
      024h 4*n   Unknown (2, 3, 4, 5, or 6)

Extended Entry RefID=2205h: (if present)

      ..   4     Unknown (100h)                     ;\exists only for WSDSET_xx,
      ..   4     Unknown (0Ch)                      ; not for SEQSET_xx
      ..   4     Unknown (0)                        ;
      ..   4     Unknown (0)                        ;/

Bank List (RefID=2101h)

      000h 4        Number of List entries
      004h (4+4)*N  Bank Entries (RefID=2206h, Offset from List+0)

Bank Entry (RefID=2206h) (eg. 5 entries) (18h bytes per entry)

      000h 4     Index in File List       (File CBNK)
      004h 4+4   Extended entry (RefID=0100h, Offset=14h, relative to Bank Entry+0)
      00Ch 4     Unknown (1)
      010h 4     Name Index in STRG Block (Name BANK_xxx)

Extended Entry RefID=0100h:

      014h 4     Number of below 4-byte entries (can be 0=None)
      018h 4*n   Resource ID (05000000h) (if any, ie. if above is nonzero)

Above list contains one entry in AR Games, which also has CGRP, maybe that's related?
WavArchive List (RefID=2103h)

      000h 4        Number of List entries
      004h (4+4)*N  WAV Archive Entries (RefID=2207h, Offset from List+0)

WavArchive Entry (RefID=2207h) (eg. 7 entries) (0Ch bytes per entry)

      000h 4     Index in File List       (File CWAR)
      004h 8     Unknown (0)
      008h 8     Unknown (0 or 1)  ;set when NEXT file is CGRP? or unrelated?

Group List (RefID=2105h)

      000h 4        Number of List entries (can be 0 if there aren't any groups)
      004h (4+4)*N  Group Entries (RefID=2208h, Offset from List+0)

Group Entry (RefID=2208h) (exists in ArGames and MiiMaker, for example)

      000h 4     Index in File List       (File CGRP)
      004h 4     Unknown (1)
      008h 4     Name Index in STRG Block (Name GROUP_xxx)

Player List (RefID=2102h)

      000h 4        Number of List entries
      004h (4+4)*N  Player Entries (RefID=2209h, Offset from List+0)

Player Entry (RefID=2209h) (eg. 7 entries) (10h bytes per entry)

      000h 4     Varies 2,8,1,1,4,1,2   ;Index in File List? (would be CSEQ/CSTM)
      004h 4     Unknown (3)
      008h 4     Name Index in STRG Block (Name PLAYER_xxx)
      00Ch 4     Unknown (0)

File List (RefID=2106h)

      000h 4        Number of List entries
      004h (4+4)*N  File Entries (RefID=220Ah, Offset from List+0)

File Entry (RefID=220Ah) (eg. only 13h entries, despite of 40h filenames)

      000h 4+4    ExtEntry (RefID=220Ch/220Dh, Offset=0Ch, relative to File Entry)
      008h 4      Zero

ExtEntry RefID=220Ch: (eg. CSEQ file, in internal FILE section):

      00Ch 4+4+4  File (RefID=1F00h/0000h, Offset relative to FILE+8, Size)
     Note: Above RefID=1F00h is used for Normal Files, whilst Group Files are
     instead using RefID=0000h (the Offset/Size do exist nonetheless, pointing
     to the CGRP file).

ExtEntry RefID=220Dh: (eg. CSTM file, in external .bcstm file):

      00Ch ...    External Filename (eg. "stream/xxx.bcstm",00h)

Final Entry (RefID=220Bh)

      000h 2  Unknown (18h, 20h, 40h)    x
      002h 2  Unknown (30h, 40h, 60h)    x
      004h 2  Unknown (00h, 04h)
      006h 2  Unknown (00h, 04h)
      008h 2  Unknown (00h, 08h)
      00Ah 2  Unknown (00h, 40h)         x
      00Ch 2  Unknown (00h, 04h, 40h)    x
      00Eh 2  Unknown (0, 1) (1 in Miiverse-posting)
      010h 2  Unknown (0)
      012h 2  Unknown (0)

     _________________________________ FILE Block _________________________________

File Block Header

      000h 4    ID "FILE"
      004h 4    FILE Block Size (same as in CSAR header)
      008h 18h  Padding to 20h-byte boundary (0)
      020h ...  Data Area (contains CSEQ, CWSD, CBNK, CWAR, CGRP files)

Note: Some of the files may also contain chunks with name INFO or FILE, that chunks are unrelated to the INFO/FILE chunks in the CSAR header).
Tools
- vgmtoolbox's Advanced Cutter/Offset Finder (extract BCWAVs without filenames)
- 3DSUSoundArchiveTool (reference implementation of CSAR extraction)

3DS Files - Sound SEQ (CSEQ Format)

CSEQ is usually found inside of CSAR (but can be also a standalone file, eg. in 3DS Camera Applet, RomFS:\sound\csnd.LZ).
CSEQ Header

      000h 4     ID "CSEQ"
      004h 2     Byte Order (FEFFh)
      006h 2     Header Size (usually 40h)
      008h 4     Version?    (can be 01000000h)
      00Ch 4     Total Filesize
      010h 4     Number of Blocks (usually 2 = DATA+LABL)
      014h 4+4+4 DATA Block (RefID=5000h, Offset from CSEQ+0, Size)
      020h 4+4+4 LABL Block (RefID=5001h, Offset from CSEQ+0, Size)
      02Ch 14h   Padding to 20h-byte boundary (0)

DATA Block

      000h 4     ID "DATA"
      004h 4     DATA Block Size (same as in CSEQ Header)
      008h ...   Data (addressed via Offsets in LABL block)
      ...  ..    Padding to 20h-byte boundary (0)

The content of the Data area is unknown, probably some midi-like notes?
LABL Block

      000h 4       ID "LABL"
      004h 4       LABL Block Size (same as in CSEQ Header)
      008h 4       Number of following List entries (eg. 26h)
      00Ch (4+4)*N List Entries (RefID=5100h, Offset from LABL+8)
      ...  ..      Padding to 20h-byte boundary (0)

List Entry Format:

      000h (4+4)*N Data Entry (RefID=1F00h, Offset from DATA+8)
      008h 4       String Length, excluding ending 00h
      00Ch LEN+1   String (ASCII, plus ending 00h) (eg. "SMF_TWL_function_xxx")
      ...  ..      Padding to 4-byte boundary (0)

3DS Files - Sound WSD (CWSD Format)

CWSD Header

      000h 4     ID "CWSD"
      004h 2     Byte Order (FEFFh)
      006h 2     Header Size (usually 20h)
      008h 4     Version?    (can be 01000000h)
      00Ch 4     Total Filesize
      010h 4     Number of Blocks (usually 1 = INFO)
      014h 4+4+4 INFO Block (RefID=6800h, Offset from CWSD+0, Size)

INFO Block

      000h 4     ID "INFO"
      004h 4     INFO Block Size (same as in CWSD Header)
      008h 4+4   ID List    (RefID=0100h, Offset from INFO+8)  ;Offs=10h
      010h 4+4   Crazy List (RefID=0101h, Offset from INFO+8)

ID List: (uh, are these Resource ID's pointing to CSAR entries):

      000h 4       Nummber of below 8-byte entries
      004h (4+4)*N Resource ID and Index (ID=050000xxh, Index=0, 1, 2, etc.)

Crazy List:

      000h 4       Nummber of below 8-byte entries
      004h (4+4)*N Crazy Entry N (RefID=4900h, Offset from Crazy List+0)

Crazy Entry:

      000h 4+4     Crazy Part1 (RefID=4901h, Offset from Crazy Entry+0)
      008h 4+4     Crazy Part2 (RefID=0101h, Offset from Crazy Entry+0)
      010h 4+4     Crazy Part3 (RefID=0101h, Offset from Crazy Entry+0)

Crazy Part1:

      000h 4       Unknown (303h)
      004h 4       Unknown (40h)
      008h 4       Unknown (3F800000h, 3FE66666h, or 3F4CCCCDh)  ;Int? Float?
      00Ch 4       Unknown (14h)
      010h 4       Unknown (1Ch)
      014h 4       Unknown (27Fh)
      018h 4       Unknown (0)
      01Ch 4       Unknown (0)
      020h 4       Unknown (08h)
      024h 4       Unknown (7F7F7F7Fh)
      028h 4       Unknown (7Fh)

Crazy Part2:

      000h 4       Unknown (1)   ;Num entries?
      004h 4+4     Child Block (RefID=4903h, Offset from 000h+0) ;Offs=0Ch
      00Ch 4       Unknown (0)
      010h 4       Unknown (08h)
      014h 4       Unknown (1)   ;Num entries?
      018h 4+4     Child Block (RefID=4904h, Offset from 014h+0) ;Offs=0Ch
      020h 4       Unknown (0)
      024h 4       Unknown (0)
      028h 4       Unknown (0)
      02Ch 4       Unknown (0)

Crazy Part3:

      000h 4       Unknown (1)   ;Num entries?
      004h 4+4     Child Block (RefID=4902h, Offset from Crazy Part3+0) ;Offs=0Ch
      00Ch 4       Unknown (0 or 2)
      010h 4       Unknown (0)

3DS Files - Sound Bank (CBNK Format)

CBNK Header

      000h 4     ID "CBNK"
      004h 2     Byte Order (FEFFh)
      006h 2     Header Size (usually 20h)
      008h 4     Version?    (can be 01000100h)
      00Ch 4     Total Filesize
      010h 4     Number of Blocks (usually 1 = INFO)
      014h 4+4+4 INFO Block (RefID=5800h, Offset from CBNK+0, Size)

INFO Block

      000h 4       ID "INFO"
      004h 4       INFO Block Size (same as in CBNK Header)
      008h 4+4     Footer Entry (RefID=0100h, Offset from Info+8) ;Offs=Near end
      010h 4+4     List Entry   (RefID=0101h, Offset from Info+8) ;Offs=10h
      018h 4       Number of following List Entries
      01Ch (4+4)*N List Entries (RefID=59xxh, Offs from INFO+18h or Offs=FFFFFFFFh)
      ...  ..      Entries for above list
      ...  4+8*X   Footer Entry

List Entry with RefID=5903h:

      Nothing (these entries have Offset=FFFFFFFFh)

List Entry with RefID=5900h:

      000h 4+4     1st Child Entry (RefID=6000h, Offset=8)  ;\these are simply
      008h 4+4     2nd Child Entry (RefID=5901h, Offset=8)  ; pointing to the next
      010h 4+4     3rd Child Entry (RefID=6000h, Offset=8)  ; child, until reaching
      018h 4+4     4th Child Entry (RefID=5902h, Offset=8)  ;/below data...
      020h 4       Bank Entry Number (0, 1, 2, etc.)
      024h 4       Unknown (21Fh)         ;RefID ?
      028h 4       Unknown (03Ch or 48h)  ;Offset? or Volume or so?
      02Ch 4       Unknown (7Fh)
      030h 4       Unknown (40h)
      034h 4       Unknown (3F800000h)
      038h 4       Unknown (0)
      03Ch 4       Unknown (20h)
      040h 4       Unknown (0)
      044h 4       Unknown (08h)
      048h 4       Unknown (7F7F7Fh)
      04Ch 4       Unknown (7Fh)

Footer Entry with RefID=0101h:

      000h     4   Number of following 8-byte entries
      004h+N*8 4   Resource ID ? (05000005h, or 05000002h in another CBNK file)
      008h+N*8 4   Footer Index (0, 1, 2, 3, etc.)

3DS Files - Sound Wave Archive (CWAR Format)

CWAR files can contain CWAV files. The CWAR files are located inside of CSAR archives.
Note: The CWARs are often left nameless (the CSAR may contain only one name entry in its STRG block (or none at all), despite of have multiple CWARs in its INFO block.
CWAR Header

      000h 4     ID "CWAR"
      004h 2     Byte Order (FEFFh)
      006h 2     Header Size (usually 40h)
      008h 4     Version?    (can be 01000000h)
      00Ch 4     Total Filesize
      010h 4     Number of Blocks (usually 2 = INFO+FILE)
      014h 4+4+4 INFO Block (RefID=6800h, Offset from CWAR+0, Size)
      020h 4+4+4 FILE Block (RefID=6801h, Offset from CWAR+0, Size)
      02Ch 14h   Padding to 20h-byte boundary (0)

INFO Block

      000h 4         ID "INFO"
      004h 4         INFO Block Size (same as in CWAR Header)
      008h 4         Number of following List entries
      00Ch (4+4+4)*N List Entries (RefID=1F00h, Offset from FILE+8, Size)
      ...  ..        Padding to 20h-byte boundary (0)

FILE Block

      000h 4     ID "FILE"
      004h 4     FILE Block Size (same as in CWAR Header)
      008h 18h   Padding to 20h-byte boundary (0)
      020h ...   Data Area (contains CWAV files)

3DS Files - Sound Wave Data (CWAV Format)

CWAV files contain audio samples for use as instruments or sound effects, somewhat resembling .wav files.
The CWAV is usually stored in a CWAR Wave Archive (with the CWAR being stored in a CSAR Sound Archive). Additionally, a CWAV block can be found inside of Banner files. And, there are also standalone CWAV files (eg. in 3DS Camera "RomFS:\sound\*.bcwav").
CWAV Header

      000h 4      ID "CWAV"
      004h 2      Byte Order (FEFFh)
      006h 2      Header Size (usually 0040h)
      008h 4      Version (02010000h)
      00Ch 4      Total File Size
      010h 2      Number of Blocks (usually 2, INFO+DATA)
      012h 2      Reserved
      014h 4+4+4  INFO Block (RefID=7000h, Offset from CWAV+0, Size)
      020h 4+4+4  DATA Block (RefID=7001h, Offset from CWAV+0, Size)
      02Ch 14h    Padding to 20h-byte boundary (0)

Info Block

      000h 4   Chunk ID "INFO"
      004h 4   Chunk Size
      008h 1   Encoding (0=PCM8, 1=PCM16, 2=DSP-ADPCM, 3=IMA-ADPCM)
      009h 1   Loop (0=Don't loop, 1=Loop)
      00Ah 2   Padding (0)
      00Ch 4   Sample Rate (eg. 3E80h = 16000Hz?)
      010h 4   Loop Start Frame (0=Begin of sample?, or 0=None when not looping)
      014h 4   Loop End Frame (eg. 409h ?) (also End Frame when not looping)
      018h 4   Unknown (0)
      01Ch 4   Unknown (1)
      020h 4+4 Sample Info     (RefID=7100h, Offset from INFO+8?) ;Offs=0Ch
      028h 4+4 Sample Data     (RefID=1F00h, Offset from DATA+8)  ;Offs=18h
      ..   ..  Sample Info
      ..   ..  ADPCM Info (if any)
      ..   ..  Padding to 20h-byte boundary (0)

Sample Info (RefID=7100h):

      000h 4+4 DSP-ADPCM Info  (RefID=0300h, Offset from INFO+?)  ;Offs=14h ;\
               IMA-ADPCM Info  (RefID=0301h, Offset from INFO+?)  ;Offs=14h ;
               No ADPCM Info   (RefID=0000h, Offset=FFFFFFFFh)    ;None     ;/
      008h 4   Unknown (0)

ADPCM Info (RefID=0300h) (when Encoding is DSP-ADPCM):

      000h 32  16bit Coefficients            ;-Whatever Coefficients
      020h 1   4bit Predictor + 4bit Scale   ;\
      021h 1   Reserved (0)                  ; Initial context
      022h 2   Previous Sample               ;
      024h 2   Second Previous Sample        ;/
      026h 1   4bit Predictor + 4bit Scale   ;\
      027h 1   Reserved (0)                  ; Loop context
      028h 2   Previous Sample               ;
      02Ah 2   Second Previous Sample        ;/
      02Ch 2 ? Padding ??                    ;-uh?

ADPCM Info (RefID=0301h) (when Encoding is IMA-ADPCM):

      000h 2   Data                          ;\Initial context
      002h 1   Table Index                   ; ...for port 10103418h+(N*20h)?
      003h 1   Padding                       ;/
      004h 2   Data                          ;\Loop context
      006h 1   Table Index                   ; ...for port 1010341Ch+(N*20h)?
      007h 1   Padding                       ;/

Data Block

      000h 4   Chunk ID "DATA"
      004h 4   Chunk Size
      008h 18h Padding to 20h-byte boundary (0)
      020h ..  Sample Data (eg. PCM16)    ;at Offsets specified in INFO block

3DS Files - Sound Wave Streams (CSTM Format)

CSTM files are very similar to CWAV files, with slightly differently arranged data, and with an additional SEEK block.
Unknown if/which games or system titles are using CSTM files. They can be reporedly found in following locations:

      - RomFS:\sound\stream\*.bcstm (eg. in Zelda Ocarina of Time)
      - Inside of a CSAR (unknown where exactly, maybe inside of CWAR blocks?)
      - CSAR's can contain RefID=220Dh entries for external CSTM file (eg. Zelda)

CSTM seems to be intended for streaming medium length recordings (longer than normal CWAV instruments/effects, and shorter than fully fledged AAC/OGG/MP3 recordings).
CSTM Header

      000h 4      ID "CSTM"
      004h 2      Byte Order (FEFFh)
      006h 2      Header Size (usually 40h)
      008h 4      Version (02000000h)
      00Ch 4      File Size
      010h 2      Number of Blocks (usually 3, INFO+SEEK+DATA)
      012h 2      Reserved
      014h 4+4+4  INFO Block Reference (RefID=4000h, Offset from CSTM+0, Size)
      020h 4+4+4  SEEK Block Reference (RefID=4001h, Offset from CSTM+0, Size)
      02Ch 4+4+4  DATA Block Reference (RefID=4002h, Offset from CSTM+0, Size)
      038h 8      Padding to 20h-byte boundary

     ________________________________ INFO Block _________________________________

Info Block

      000h 4    Chunk ID "INFO"
      004h 4    Chunk Size
      008h  4+4 Stream Info Entry (RefID=4100h, Offset relative to INFO+8)
      010h  4+4 Track Info List   (RefID=4101h, Offset relative to INFO+8)
      018h  4+4 Channel Info List (RefID=4102h, Offset relative to INFO+8)
      020h  38h Stream Info Entry      ;\
      058h  ..  Track Info List        ; from above Header  ;<-- 4+(N*8) ?
      ..    ..  Channel Info List      ;/                   ;<-- 4+(N*8) ?
      ..    ..  Track Info Entries     ;\from above Lists
      ..    ..  Channel Info Entries   ;/

If encoding is DSP-ADPCM:

      ..    ..  DSP-ADPCM Info Entries

If encoding is IMA-ADPCM:

      ..    ..  IMA-ADPCM Info Entries

The info block is aligned to 20h bytes. uh, that is, the "Stream Info" block?
Stream Info Entry

      000h 1    Encoding      (0=PCM8, 1=PCM16, 2=DSP-ADPCM, 3=IMA-ADPCM)
      001h 1    Loop          (0=Don't loop, 1=Loop)
      002h 1    Channel Count
      003h 1    Padding
      004h 4    Sample Rate
      008h 4    Loop Start Frame
      00Ch 4    Loop End Frame
      010h 4    Sample Block Count
      014h 4    Sample Block Size
      018h 4    Sample Block Sample Count
      01Ch 4    Last Sample Block Size
      020h 4    Last Sample Block Sample Count
      024h 4    Last Sample Block Padded Size
      028h 4    Seek Data Size
      02Ch 4    Seek Interval Sample Count
      030h 4+4  Sample Data   (RefID=1F00h, Offset from "Data Block Data field")

Track Info Entry

      000h 1    Volume
      001h 1    Pan
      002h 2    Padding
      004h 4+4  Channel Index Byte Table (RefID=0100h, Offset from Volume field)
      00Ch ..   Channel Index Byte Table (at above Offset)
      ..   ..   Padding to 4-byte boundary (0)

Byte Table:

      000h 4      Count
      004h Count  Elements

Channel Info Entry (aka Sample Info)

      000h 4+4  DSP-ADPCM Info  (RefID=0300h, Offset from here?)  ;\depending
                IMA-ADPCM Info  (RefID=0301h, Offset from here?)  ; on Encoding
                No ADPCM Info?  (RefID=0000h, Offset=FFFFFFFFh)   ;/

DSP-ADPCM Info:

      000h 32  Param (16bit Coefficients)    ;-Whatever Coefficients
      020h 1   4bit Predictor + 4bit Scale   ;\
      021h 1   Reserved (0)                  ; Initial context
      022h 2   Previous Sample               ;
      024h 2   Second Previous Sample        ;/
      026h 1   4bit Predictor + 4bit Scale   ;\
      027h 1   Reserved (0)                  ; Loop context
      028h 2   Previous Sample               ;
      02Ah 2   Second Previous Sample        ;/
      02Ch 2 ? Padding ??                    ;-uh?

IMA-ADPCM Info:

      000h 2   Data                          ;\Initial context
      002h 1   Table Index                   ; ...for port 10103418h+(N*20h)?
      003h 1   Padding                       ;/
      004h 2   Data                          ;\Loop context
      006h 1   Table Index                   ; ...for port 1010341Ch+(N*20h)?
      007h 1   Padding                       ;/

     ________________________________ SEEK Block _________________________________

Seek Block

      000h 4    Chunk ID "SEEK"
      004h 4    Chunk Size
      008h ..   Data ... whatever ?

The seek block is aligned to 20h bytes.

     ________________________________ DATA Block _________________________________

Data Block

      000h 4    Chunk ID "DATA"
      004h 4    Chunk Size
      008h ..   Data ... probably sample data ?

The data block is aligned to 20h bytes, as well as the data field's actual sample data.

     ________________________________ Notes..... _________________________________

Whatever Reference Type

      RefID=0101h = Reference Table ?

Tools
The following tools can play BCSTMs and convert them to other formats:

      Isabelle Sound Editor
      vgmstream
      Every File Explorer

3DS Files - Sound Group (CGRP Format)

CGRP files are included in some CSAR files, but not always (for example, a CGRP can be found in the "AR Games" system title).
The purpose of CGRP is unknown. The INFO block seems to be mainly good for re-ordering whatever indices. And the FILE block is somewhat empty.
CGRP Header

      000h 4     ID "CGRP"
      004h 2     Byte Order (FEFFh)
      006h 2     Header Size (usually 40h)
      008h 4     Version?    (can be 01000000h)
      00Ch 4     Total Filesize
      010h 4     Number of Blocks (usually 2 = INFO+FILE)
      014h 4+4+4 INFO Block (RefID=7800h, Offset from CGRP+0, Size)
      020h 4+4+4 FILE Block (RefID=7801h, Offset from CGRP+0, Size)
      02Ch 14h   Padding to 20h-byte boundary (0)

INFO Block

      000h 4       ID "INFO"
      004h 4       INFO Block Size (same as in CGRP Header)
      008h 4       Number of following List entries (eg. 40h)
      00Ch (4+4)*N List Entries (RefID=7900h, Offset from INFO+8)
      ...  ..      Padding to 20h-byte boundary (0)

List Entry Format:

      000h 4     Unknown (0..NumListEntries, in no specific order)
                         (and apparently one value skipped, since using values
                          in range 0..Num would be Num+1 values in total)
      004h 4     Unknown (FFFFFFFFh)
      008h 4     Unknown (FFFFFFFFh)
      00Ch 4     Unknown (0)

FILE Block

      000h 4     ID "FILE"
      004h 4     FILE Block Size (same as in CGRP Header) (=20h)
      008h 18h   Padding to 20h-byte boundary (0)

Apart from the above header, there is no actual data in the FILE block, unless it's meant to be a prefix for the following CWAR blocks in the CSAR file?

3DS Files - Sound IDs (CSID Format)

Some titles have the CSAR file bundled with a separate CSID file with .csid extension (eg. 3DS Health Safety RomFS:\sound\Main.csid and 3DS Instruction Manual applet RomFS:\sound\Main.csid), which appears to be a relict from devkit, used before/after generating the CSAR file.
The file contains Symbols and 32bit Resource IDs in ASCII, oddly, with an UTF-8 Byte Order Mark (EFh,BBh,BFh) in the file header.

3DS Files - Sound DSP Binary (DSP1 aka .cdc)

Teak DSP binaries are usually having extension .cdc (supposedly unrelated to the "cdc" codec services). DSP binaries are found in some titles (eg. 3DS eShop RomFS:\sound\dspaudio.cdc, 3DS Browser Applet RomFS:\snd\dspaudio.cdc, and (LZ11-compressed) 3DS Nintendo Zone RomFS:\dspaudio.cdc.nwcx).
Unknown if there is some kind of default DSP driver for use by other titles.
Header (300h bytes)

      000h       100h RSA Signature across header bytes [100h-2FFh]
      100h       4    ID ("DSP1")
      104h       4    Total Filesize
      108h       1    Code Memory (bit0-7, for 8 32Kbyte blocks) (usually FFh)
      109h       1    Data Memory (bit0-7, for 8 32Kbyte blocks) (usually FFh)
      10Ah       3    Zero (00h,00h,00h)
      10Dh       1    Special Segment DSP Area (00h..02h) (usually 02h=Data)
      10Eh       1    Number of segments (must be 01h..0Ah)
      10Fh       1    Flags (bit0=RecvData, bit1=WithSpecialSegment)
      110h       4    Special Segment DSP Address in 16bit words
      114h       4    Special Segment Size in bytes (usually 214h)
      118h       8    Zero
     Segment record 0..9:
      120h+N*30h 4    Segment N File Offset in bytes (300h and up)
      124h+N*30h 4    Segment N DSP Address in 16bit words (max 1FFFFh or 0FFFFh)
      128h+N*30h 4    Segment N Size in bytes
      12Ch+N*30h 3    Segment N Zero
      12Fh+N*30h 1    Segment N DSP Area (00h..02h)
      130h+N*30h 20h  Segment N SHA256 across Segment Data
      300h       ..   Segment Data..

DSP Areas at [10Dh] and [124h+N*30h] can be:

      0 = DSP Code Memory (at ARM:1FF00000h and up) (DSP:00000h..1FFFFh)
      1 = DSP Code Memory (at ARM:1FF00000h and up) (DSP:00000h..0FFFFh only?)
      2 = DSP Data Memory (at ARM:1FF40000h and up) (DSP:00000h..0FFFFh only?)

Flags.bit0=RecvData
If set, DSP module calls DSP:RecvData on "all three registers" and expects them to reply value, uh, that is... probably done as handshake AFTER uploading the DSP binary?
Flags.bit1=WithSpecialSegment
If set, 214h bytes are read from CfgS:GetConfigInfoBlk8 block 70000h, and then copied to the special segment area/address. If the reading fails, zeroes are written in its place. The purpose of this segment is currently unknown.

3DS Files - Module NWM (Wifi Driver)

NWM File/versions
The wifi driver can be found in following locations (each console should have one normal mode file, and one safe mode file):

      3ds:\title\00040130\00002d02\content\000000vv.app  ;NWM Normal mode (all 3DS)
      3ds:\title\00040130\00002d03\content\0000000v.app  ;NWM Safe mode (Old3DS)
      3ds:\title\00040130\20002d03\content\0000000v.app  ;NWM Safe mode (New3DS)

The .app file contains a compressed .code file (inside of the NCCH ExeFS). That .code file contains ARM11 code and six datablocks with the actual Xtensa wifi firmware (similar as in the DSi wifi firmware):

      Stub.data   038h bytes                   ;\Database and EEPROM reading stub
      Stub.code   316h bytes                   ; (always same size/content)
      Database    1E8h bytes                   ;/
      Main.type1  0FD3h, 10F7h, or 1B1Bh bytes ;\Main firmware (compressed)
      Main.type4  A053h, A482h, or A5EBh bytes ; (size/content varies per version)
      Main.type5  78F6h, or 7A2Eh bytes        ;/

There are a few safe mode versions, and dozen(s) of normal mode versions. The versions may contain different ARM11 code, and/or different Xtensa code (as shown above, there are at least three revisions of the Xtensa "Main" code blocks (spotted in four different NWM files, so there may be much more variations)).
NWM Main Type1/4/5
There are three variants of the Main firmware, called Type1/4/5 (because the ARM11 code uses "CMP r0,1/4/5" opcodes to determine which one to use).

     Type1 = Standard functions for normal internet access
      Type1 supports the same commands/events as on DSi
     Type4 = Special AP Mode and whatever:
      WMIcmd(004Ah..0052h) seem to AP mode (alike Atheros cmd F00Bh..F013h)
      WMIcmd(0053h,0055h..005Fh) unknown
      WMIevent(101Dh,101Fh,1020h,1022h,1024h,1025h) unknown
      Type4 can be used for normal internet access (when ignoring event 1025h)
     Type5 = Special MacFilter, GameID, and built-in SHA1 function
      Contains ascii strings "MACFilter" and "GameID", and a built-in SHA1 function
      WMIcmd(0060h..0073h) unknown
      WMIevent(1021h,1023h,1026h,1027h) unknown
      Type5 doesn't seem to support normal internet access (it can't even find APs)

Type4/5 are probably for Nintendo-specific special local network multiplayer features, possibly related to "Streetpass" (in sleep mode?) and "DownloadPlay" (for single gamepak), and/or other purposes.
Addresses in ARM11 Pool
The ARM11 code does reference the Xtensa datablocks with "LDR Rd,=address" opcodes, hence having the datablock addresses stored in the literal pool. The pool isn't exactly intended to be used as "table of contents", but it can be misused for that purpose:
Search for constant 00524C00h, check that constant 000003EDh is located at the expected offset, then extract the datablock start/end addresses from the corresponding pool locations, subtract 10000h to convert addresses to .code file offsets.
The NWM file does contain two pools: One pool with the Main type1/4/5 addresses, followed by by larger pool with the same addresses, plus addresses for the Database and EEPROM reading stub code/data.
Most files (3 of 4 known files) are using this pool structure:

      Newer Small Pool:
      00h main.dst (and stub.data.dst) ;CONST (00524C00h)
      04h whatever value               ;CONST (000003EDh)
      08h main.src.type1.end    ;\Type1 (basic internet)
      0Ch main.src.type1.start  ;/
      10h main.src.type4.end    ;\Type4 (ApMode and whatever)
      14h main.src.type4.start  ;/
      18h main.src.type5.end    ;\Type5 (MacFilter,GameId,Sha1)
      1Ch main.src.type5.start  ;/
      Newer Large Pool:
      00h whatever.addr.plus00h         ;\
      04h whatever.addr.plus04h         ; INCREASING addresses
      08h whatever.addr.plus08h         ;
      0Ch whatever.addr.plus0Ch         ;/
      10h whatever.other.addr
      14h main.dst (and stub.data.dst) ;CONST (00524C00h)
      18h whatever value               ;CONST (000003EDh)
      1Ch main.src.type1.end   ;\Type1 (basic internet)
      20h main.src.type1.start ;/
      24h main.src.type4.end   ;\Type4 (ApMode and whatever)
      28h main.src.type4.start ;/
      2Ch main.src.type5.end   ;\Type5 (MacFilter,GameId,Sha1)
      30h main.src.type5.start ;/
      34h database.src.end     ;\Datab ;SAME as stub.code.src.start
      38h database.src.start   ;/
      3Ch database.dst                 ;CONST (0053FE18h)
      40h stub.code.src.end    ;\Stubc
      44h stub.code.src.start  ;/      ;SAME as database.src.end
      48h stub.code.dst                ;CONST (00527000h)
      4Ch stub.data.src.end    ;\Stubd
      50h stub.data.src.start  ;/
      54h whatever.thumb.code.addr1
      58h whatever.thumb.code.addr2
      5Ch whatever.thumb.code.addr3

There is at least one older file using this pool structure:

      Older Small Pool:
      00h main.dst (and stub.data.dst) ;CONST (00524C00h)
      04h maintype5.src.end
      08h maintype5.src.start
      0Ch maintype1.src.end
      10h maintype1.src.start
      14h maintype4.src.end
      18h maintype4.src.start
      1Ch whatever value               ;-CONST (000003EDh)
      Older Large Pool:
      00h whatever.addr.plus00h        ;\
      04h whatever.addr.plus04h        ;
      08h whatever.addr.plus08h        ; INCREASING addresses
      0Ch whatever.addr.plus0Ch        ;
      10h whatever.addr.plus10h        ;/
      14h whatever.other.addr
      18h main.dst (and stub.data.dst) ;CONST (00524C00h)
      1Ch maintype5.src.end
      20h maintype5.src.start
      24h database.dst                 ;CONST (53FE18h)
      28h database.src.end             ;SAME as stub.code.src.start
      2Ch database.src.start
      30h stub.code.dst                ;CONST (527000h)
      34h stub.code.src.end
      38h stub.code.src.start          ;SAME as database.src.end
      3Ch stub.data.src.end
      40h stub.data.src.start
      44h whatever.thumb.code.addr1
      48h whatever.thumb.code.addr2
      4Ch whatever.thumb.code.addr3
      50h maintype1.src.end
      54h maintype1.src.start
      58h maintype4.src.end
      5Ch maintype4.src.start
      60h whatever value               ;CONST (000003EDh)

Moreover, there are dozens of unknown files, which may (or may not) use yet different pool structures.

Non-DS Files - RARC Archives

RARC archives are used in Wii and GameCube games like Super Mario Galaxy 1 & 2 and Supermario Sunshine. The RARC format is unique in terms of storing duplicated folder data in both Folder List and Directory Entries.
RARC Header (...probably bug-endian?)

      000h 4   ID "RARC"
      004h 4   Total Filesize
      008h 4   Size of RARC Header (always 20h)
      00Ch 4   Size of Info Block (plus Folder List, Directory List, String Table)
      010h 4   Size of File Data area
      014h 4   Size of File Data again? (always same as the previous value)
      018h 8   Unknown (zerofilled)
      020h ..  Info Block (plus Folder List, Directory List, String Table)
      ...  ..  File Data

Info Block (20h-bytes, plus Folder List, Directory List, String Table)

      000h 4   Folder List Size/10h    (number of folders)
      004h 4   Folder List Offset      (relative to the start of Info block)
      008h 4   Directory List Size/14h (number of files+folders)
      00Ch 4   Directory List Offset   (relative to the start of Info block)
      010h 4   String Table Size/1     (in bytes)
      014h 4   String Table Offset     (relative to the start of Info block)
      018h 2   Number of directory entries that are Files (number of files)
      01Ah 6   Unknown (zerofilled)
      020h ..  Folder List (10h bytes per entry)
      ...  ..  Directory List (14h bytes per entry)
      ...  ..  String Table

Folder List Entries (10h-bytes each) (first entry is root folder)

      000h 4   Short name (first 4 chars of name, uppercase, spc-padded, eg. ROOT)
      004h 4   Name Offset (relative to start of string table)
      008h 2   Name Checksum
      00Ah 2   Number of Directory entries in this folder
      00Ch 4   Index of first Directory entry for this folder

Directory Entries (14h-bytes each) (contains both Files and Folders)

      000h 2   Index of this directory entry (aka File ID or so) (or FFFFh=Folder)
      002h 2   Name Checksum
      004h 2   Type/Attributes? (1100h=File, 0200h=Folder)
      006h 2   Name Offset (relative to start of string table)
      008h 4   File Data Offset   (or, for folders: Index in Folder List)
      00Ch 4   File Size in bytes (or, for folders: unused)
      010h 4   Unknown (zerofilled)

String Table & Name Checksums
The string table consists of null-terminated ASCII(?) strings. The Name Checksums (in Folder List and Directory Entries) are calculated as so:

      sum=0, i=0, while name[i]<>00h do sum=((sum*3)+name[i]) AND FFFFh, i=i+1

Non-DS Files - U8 Archives

U8 archives are used in Mario Kart Wii and maybe other games (something called Wii discs is reportedly using a similar format, too).
U8 Format (big endian)

      000h 4     ID (55AA382Dh) (appears as U.8- in hex editors) (nicknamed U8)
      004h 4     Offset to Directory (aka 20h?)
      008h 4     Size of Directory including String Table
      00Ch 4     Offset to File Data
      010h 10h   Reserved
      020h N*0Ch Directory Entries (0Ch-bytes each)
      ...  ..    String Table (ASCII strings, terminated by 00h)
      ...  ..    File Data

Directory Entries (starting with root entry)

      000h 1    Type (00h=File, 01h=Directory) (other values never seen)
      001h 3    24bit Filename Offset (relative to begin of String Table)
      004h 4    File: Offset to data
                Directory: Index of the parent directory
      008h 4    File: Size of data
                Directory: Index of the first node that is not part of this
                  directory (skip to node)

Note: The U8 format is about same as 3DS "darc" format (with different header, different byte-order, and ASCII instead of UTF-16 names).
3DS Files - Archive DARC

3DS Console IDs

Hardware IDs
The main Console ID is stored in OTP memory:
3DS Crypto - PRNG and OTP Registers
The eMMC CID is used for generating console specific encryption keys. The SD card CID is also used for generating a SD card specific <ID1> folder name.
3ds:\rw\sys\LocalFriendCodeSeed_B (or Seed_A, if it exists) (110h bytes)

      000h 100h  RSA-2048 signature across following 10h-bytes  ;\
      100h 1     Zero                                           ; same values are
      101h 1     Devkit (00h=Retail, 01h=Devkit)                ; also stored in
      102h 6     Zero                                           ; movable.sed
      108h 8     Decrypted OTP[08h..0Fh]                        ;/

This can be also retrieved via "PSPXI:GetLocalFriendCodeSeed".
3ds:\private\movable.sed (120h or 140h bytes)

      000h 4     ID "SEED"
      004h 1     Zero
      005h 1     Zero (or 01h if extra bytes at [120h..13Fh] are appended)
      006h 2     Zero
      008h 100h  RSA-2048 signature across following 10h-bytes  ;\same values are
      108h 1     Zero                                           ; also stored in
      109h 1     Devkit (00h=Retail, 01h=Devkit)                ; LocalFriendCode
      10Ah 6     Zero                                           ; Seed_B (or _A)
      110h 8     Decrypted OTP[08h..0Fh]        ;\used as AES   ;/
      118h 4     Decrypted OTP[10h..13h]+Offset ; KeyY for 3
      11Ch 4     Decrypted OTP[14h..17h]        ;/keyslots
     The original movable.sed from the factory is only 120h-bytes.
     Below extra data is written to the file when doing a System Format.
      120h 4     Offset (added to above Decrypted OTP[10h..13h] entry)
      124h 0Ch   Zero
      130h 10h   AES-MAC (NAND dbs keyslot) across SHA256 across bytes [000h..12Fh]

Bytes [110h..11Fh] are used as KeyY for AES keyslots 30h, 34h, and 3Ah:

      Keyslot 30h  AES-CMACs for non-DSiWare in sd:\Nintendo 3DS\ and 3ds:\data\
      Keyslot 34h  AES encryption in sd:\Nintendo 3DS\
      Keyslot 3Ah  AES-CMACs for DSiWare in sd:\Nintendo 3DS\

Bytes [110h..11Fh] are also used to derive the <ID0> folder name (see below).
Movable.sed is transferred to the destination 3DS during a System Transfer. The movable.sed keyY high u64 is updated on the source 3DS during a System Transfer, and when doing a system format with System Settings.
3ds:\data\<ID0>\ (<ID0> folder on 3DS partition)
sd:\Nintendo 3DS\<ID0>\<ID1>\ (<ID0>\<ID1> folder on SD card)
The <ID0> folder name is derived by computing the SHA256 across moveable.sed bytes [110h..11Fh], and then converting the first 4 words of the SHA256 into a lowercase ASCII string (with the byte order reversed in each of the four words, and with the last 4 words left unused).
The <ID1> folder name is derived by swapping around the byte order of the SD card CID: The CID is rotated 8-bits to the left (uh, that means the ending 00h padding byte is moved to begin?). Then, the word-order is reversed. And then, the halfwords are converted into ascii string (with byte-order for each byte-pair reversed), or so?
3ds:\rw\sys\SecureInfo_A (111h bytes) (Region and Serial/Barcode)

      000h 100h  RSA-2048 signature across following 11h-bytes
      100h 1     Region (0=JPN, 1=USA, 2=EUR, 3=Reserved, 4=CHN, 5=KOR, 6=TWN)
      101h 1     Normally zero
      102h 0Fh   Serial/Barcode, without ending check digit (ASCII, zeropadded)

The serial/barcode consists of 2-3 letters, followed by 8 digits, followed by a checksum digit.
The first letter indicates the console model:

      3DS             C  (or E for devunits)
      3DS XL/LL       S  (or R for devunits)
      2DS             A  (or P for devunits)
      New 3DS         Y  (or Yxx00 for devunits)
      New 3DS XL/LL   Q  (or Qxx00 for devunits)
      New 2DS XL/LL   N  (or Nxx01 for devunits)

The next 1-2 letter(s) indicate the region:

      JPN Japan                          JF,JH,JM
      USA North America                  W
      USA Middle East, Southeast Asia    S
      EUR Europe                         EF,EH,EM
      EUR Australia                      AG,AH
      CHN China (iQue)                   CF,CH,CM
      KOR South Korea                    KF,KH,KM
      TWN Taiwan                         ...unknown?

The checksum digit is found on the consoles barcode sticker, but isn't included in the SecureInfo_A file. However, the checksum can be calculated across 1st-8th digit (and ignoring the leading letters):

      9th = (250 - (1st+3rd+5th+7th) - 3*(2nd+4th+6th+8th)) mod 10

The RSA private key for retail is unknown. The private key for devkits is included in the devkit system updater package.

3DS eMMC and MCU Images

eMMC Images
no$gba can load 3DS eMMC images from following files in no$gba folder (currently that merely allows to view eMMC images in Window/Filesystem, ie. there isn't any actual 3DS emulation supported in no$gba):

      3DS-#.mmc      ;\with "#" being the machine number ("1".."C")
      New3DS-#.mmc   ;/

For decrypting the image, CID and OTP needs to be stored at following eMMC offsets:

      DC00h 20h   ID '3DS CID/OTP/NCSD/FIRM BackupData'
      DC20h 10h   eMMC CID (from eMMC command CMD10)
      DC30h D0h   Reserved
      DD00h 100h  OTP   (from ARM9 I/O address 10012000h)
      DE00h 200h  Copy of original NCSD  (from eMMC offset 00000000h)
      E000h 1000h Copy of original FIRM0 (from eMMC offset 0B130000h)
      F000h 1000h Copy of original FIRM1 (from eMMC offset 0B530000h)

The copy of original NCSD/FIRM0/FIRM1 allows to uninstall sighax-based stuff (or to install such stuff; doing that works even without having OTP dump, as long as the unencrypted content of the NCSD/FIRM0/FIRM1 sectors is known).
MCU Firmware Images
The MCU image can be viewed in no$gba's RL78 disassembler (via Alt+W, R). The image is loaded from following files in no$gba directory:

      3DS.mcu
      New3DS.mcu

The file should contain a copy of the whole 8000h-byte MCU flash memory:

      0000h 1000h Part 1 current version
      1000h 1000h Part 1 old version backup
      2000h 3000h Part 2 current version
      5000h 3000h Part 2 old version backup

If the old version areas aren't dumped, best leave them empty.
Atheros Wifi ROM image
The Wifi ROM image can be viewed in no$gba's Xtensa disassembler (via Alt+W, X). The image is loaded from following file (in no$gba directory):

      AR6014G.ROM  ;3DS wifi chip     (256Kbytes)

3DS Component Lists

3DS Component List

     PCB "C/CTR-CPU-01"
      U1   bga   "1048 0H, CPU CTR, (M)(C)2010, Nintendo, JAPAN ARM" (main cpu)
      U2   bga   "F JAPAN, MB82M8080-07L, 1040 M90, E1"              (main ram)
      U3   bga   "Texas Instruments, 93045A4, 0AAH86W GI" (PCB back, below YXAB)
      U4   bga   "Texas Instruments, PAIC301DB, 0AA37DW, GI"         (TSC)
      U5   bga   "TOSHIBA THGBM2G3P1FBAI8, VX2306, TAIWAN, 10459AE"  (eMMC)
      U6   bga   "UC CTR, 041KM73, KG10"                             (MCU)
      U?? 16pin  "CKP, TI 09W, ZF1T"     (PCB back, above YXAB)  (battery charger)
      U8   8pin  "17040, 08A45" MAX17040 (PCB back, above PWR button) (fuel gauge)
      U9  xxpin  "2048, 33DH, X1MAQ" or so (small, below/right of PAIC) (accelero)
      U10  3pin  "HOX" or "XOH" (PCB back, below/right of YXAB) (magnet sensor?)
      U11 xxpin  unsharp... INVENSENSE or so (right of main cpu)  (gyroscope?)
      U12  6pin  "EPB" (between main cpu and wifi socket)
      U13  6pin  "?" (right of PAIC)
      Q1   6pin  "JG" (PCB back, right of POWER button)
      Q4   6pin  "?" (between PAIC and UC CTR)
      X1   4pin  "16.756" osc (near main CPU)
      X2   4pin  "CA038" osc (near UC CTR)
     Wifi board "DWM-W028"
      Un  80pin Wifi "Atheros, AR6014G.AL1C, N2T689,00B, 1036, TAIWAN" ;76+4pin
      Un   8pin Wifi SPI FLASH "32A, 0VX, 46"
      Un   8pin Wifi I2C EEPROM "08B, H1, 0DQ"
      Un   4pin voltage regulator? "M12, KA"
      Qn   4pin Crystal "40.000"
      Pn  50pin Connector to mainboard
      Pn   2pin Antenna connector
     IrDA board "CTR-IR-01 "
      U1   xpin IR photo led/transistor unit
      U2  24pin IrDA chip "NXP, S750, 0803, TSD031C"
     SD/MMC slot board
      Pn   Xpin Connector to mainboard
      Pn   Xpin Connector to full-size SD/MMC card
     Daughterboards:
      wifi-board, IrDA-board, sd slot, battery, etc - unknown
     XXXxxx...
      and probably much more unknown stuff...

3DS XL
2DS
New3DS
New2DS XL
Unknown. These consoles seem to be quite rare, and no PCB photos exist...?
New3DS LL Component List (aka japanese version of New3DS XL)
Mainboard (PCB "RED-CPU-01 SIDE B 11-1, [05: 14 071], RED-CPU-01 SIDE A")

     Chips on Side B (top side, access requires removing mainboard):
     Un  bga   CPU "1485 16, CPU LGR A, (C) 2014, Nintendo, JAPAN ARM"  ;\
     Un  bga   RAM "F JAPAN, 82MK9A9A, 7L FCRAM, 1429969, E1"           ;
     Un  6pin  MAX8570EUT+T for upper backlight "ABTJ"                  ; Side B
     Un  sqr   Wifi "ATHEROS, AR6014G-AL1C, NKY197.00B, 1422, TAIWAN"   ;
     Un  bga   eMMC "dotcode, SAMSUNG 410, KLM4G1YE0C-B301, CDA519GLN"  ;
     Un  8pin  Wifi-EEPROM I2C "408F, B347" (HN58X2408F; 1Kx8)          ;
     Un  bga   MCU "UC KTR, 423KM01, 'TK14"                             ;
     Un  bga   Powerman? "TexasInstr, 93045A4, 3CAK08W L, GI"           ;/
     Chips on Side A (bottom side, easily accessible):
     Un  16pin BQ24072 battery charger "CKP, TI 3A1, CBYS" (near ext.supply input)
     Un  6pin  power/charge? "9D" (or "06"?) (near ext.supply input)
     Un  6pin  power "635Q" (under powerman) (...maybe lower backlight?)
     Un  24pin IrDA "U8997, 3522" (nocash), or "NXP, S750, 1603, TSD438C" (ifixit)
     Un  16pin Gyroscope? less-near infra red "IT3B,315BA1,LT425A" (like ITG-1010?)
     Un  32pin NFC Broadcom BCM20791 "20791UZ, KMLG 25, TD1430, 3976901W"
     Un  8pin  Wifi-FLASH SPI(?) "32B, 3XH, .01" (4Kx8) (near AIC)
     Un  bga   AIC "TexasInstr, AIC3010D, 3BC473W, GI" (mic/sound/touchscr)
     Un  16pin Accelerometer? near AIC and headphone "KXTKK, 40860, .3413" Kionix?
     Un  bga   TCA6416A IO Expander "PH416A, TI 46T" ;near top-screen connectors
     Other stuff:
     Xn  4pin "CA405" or so (near UC KTR, probably for RTC)
     Xn  4pin "40000, K42BY" (under atheros, probably for Wifi)
     Xn  4pin "13000, K413Y" (under cpu, probably whatever) (to near-field chip?)
     Xn  4pin "D164G" or so  (under cpu, probably whatever) (for CPU?)
     Ix  Infrared receiver/transmitter
     Fn  Fuse (for external charger + pin, near charger connector)
     Pn  2pin External Power supply
     Pn  3pin External Headphone
     Pn  2pin Connector to antenna
     Pn ??pin Connector to Button board (many pins)
     Pn ??pin Connector to MicroSD slot (medium pins)
     Pn  4pin Connector to Front panel Reset button? and MIC
     Pn  4pin Connector to Front panel Home button? (4pins, only 2 wires attached)
     Pn  Connector to bottom-shell (left shoulder (8pin+shield?, only 4 wires used)
     Pn  Connector to bottom-shell (right shoulder (8pin+shld?, only 4 wires used)
     Pn  4pin Connector to NFC (rectangle under bottom screen) (only 2 wires used)
     Pn  4pin Connector to analog stick (above dpad)
     Pn  4pin Connector to bottom screen, touchscreen
     Pn  4pin Connector to bottom screen, backlight (4pin, only 2 wires used)
     Pn ??pin Connector to bottom screen, video (many pins)
     Pn ??pin Connector to top screen? ;\presumably video,backlight,cameras,sound
     Pn ??pin Connector to top screen? ; (many pins on each connector)
     Pn ??pin Connector to top screen? ;/
     Pn  1pin Goldplate as additonal connection to cartridge board GND
     Transistors/resistors/capacitors and the like
     Barcode/sticker "22946012 Q01011K N"

Button board (PCB "F-7, PWB, /ABXY, /AU-C, /RED-01, CS, 01, 3814")

     Un  44pin ?? Chip "428A2, HF374, 7NU9"  ;for C-stick and ZL/ZR-buttons?
     Un  3pin "(M)UN" (large thing, right of start button) (magnet sensor?)
     Un  8pin "7048, xxxxxx?" (tiny bga chip, right of select button) (fuel gauge)
     Pn  Connector to mainboard
     Pn  Connector to battery (3pin)
     Pn  Connector to rubber nibble (C-Stick) (4pin)
     Pn  Connector to shoulder (8pin)
     Sw  Six buttons (A,B,X,Y,Sel,Start)
     Sw  Front button (Power)
     Fn  Fuse (for battery + pin, above wifi led)
     Led Four Front LEDs (two single ones, and one LED-pair)
     Led Notification LED (small 4pin RGB LED? under shoulder-connector)
     Transistors/resistors and the like
     Barcode/sticker "30946012 Z0101E9 X"

DPAD board (PCB "F-KEY 01, R, ZD, HF, 4354.")

     Pn  Connector to cartridge slot board (5pin)
     Sw  Four switches (Up,Down,Left,Right)

Cartridge Slot board (PCB "(DC)17P-01, C-3, 1 '14 12")

     Pn  Cartridge Slot ("4081911")
     Pn  Connector to mainboard
     Pn  Connector to DPAD board (5pin)
     Pn  Goldplate as additonal connection to mainboard GND

Battery:

     Name "Nintendo SPR-003, Rechargeable Battery, 3.7V 1750mAh 6.5Wh"
     Dotcode with text "MKH905D10"
     Back side "Li-ion 00, SPR-A-BPAA-C1"

Bottom Screen:

     Name "1912TSS140725, 21P4808L, B0014747QTFD" (4.18")

Top-screen unit

     black ribbon cable: to camera unit      ;outer/rear cable
     orange ribbon cable: to slider boards   ;middle cable
     orange ribbon cable: to lcd screen      ;inner/front cable
     red cable: to wifi antenna
     1x  LCD with Dotcode/sticker "LAM049M003A1, 0020S4911848"
     2x  2pin speaker's "G4830V23A" or "G4B30V23A" or so
     1x  2pin wifi-antenna (nameless pcb)
     1x  camera unit (with two pcbs, 3 cameras, and shielding, see below)
     2x  slider boards (see below)

Left slider/speaker board:

     1x  volume slider (9.8Kohm)
     1x  wires to left speaker
     1x  13pin connector to lcd screen (maybe parallax or whatever)
     1x  4pin connector to lcd screen (maybe backlight and/or whatever)

Right slider/speaker board:

     1x  3d slider (8.4Kohm)
     1x  wires to right speaker

Front facing camera board:

     two cameras, capacitors (C1..C12), FB1, FB2

Self facing camera board:

     one camera, capacitors (C1..C5), FB1, R1, Q1, D1 (ir-led?)

Case/bottom

     "(new), Nintendo, o3DS LL, (C)2014 Nintendo Made in China RED-001"
     "[MIC/KS], EC-14016, RED-RB-JPN-C0"
     "[R]007-AC0104, [T]D14-0144001, V(Ci Li-ion, (Nintendo)"
     Barcode/sticker "QJF10203741 6"

3DS Chipset Pinouts

New Gyroscope (ITG-1010)

      1    VDDIO    Digital I/O supply voltage
      2    SCL/SCLK I2C serial clock (SCL); SPI serial clock (SCLK)
      3    SDA/SDI  I2C serial data (SDA); SPI serial data input (SDI)
      4    AD0/SDO  I2C Slave Address LSB (AD0); SPI serial data output (SDO)
      5    /CS      SPI chip select (Low=SPI mode, High=I2C mode)
      6    RESV     Reserved. Connect to Ground
      7    INT      Interrupt digital output (totem pole or open-drain)
      8    FSYNC    Frame synchronization digital input. Connect to GND if not used
      9-12 NC       Not internally connected, may be used for PCB trace routing
      13   GND      Power supply ground
      14   REGOUT   Regulator filter capacitor connection
      15   RESV-G   Reserved. Connect to Ground
      16   VDD      Power supply voltage

Old Gyroscope (ITG-3200)

      1     CLKIN   Optional external ref clock input, connect to GND if unused
      2-5   NC      Not internally connected, may be used for PCB trace routing
      6-7   RESV    Reserved. Do not connect
      8     VLOGIC  Digital IO supply voltage. VLOGIC must be = VDD at all times
      9     AD0     I2C Slave Address LSB
      10    REGOUT  Regulator filter capacitor connection
      11    RESV-G  Reserved - Connect to ground.
      12    INT     Interrupt digital output (totem pole or open-drain)
      13    VDD     Power supply voltage
      14-17 NC      Not internally connected. May be used for PCB trace routing
      18    GND     Power supply ground
      19    RESV    Reserved. Do not connect
      20    CPOUT   Charge pump capacitor connection
      21-22 RESV    Reserved. Do not connect
      23    SCL     I2C serial clock
      24    SDA     I2C serial data

Accelerometer (LIS331DLH)

      1  Vdd_IO      Power supply for I/O pins
      2  NC          Not connected
      3  NC          Not connected
      4  SCL,SPC     I2C.clock (or SPI.clock)
      5  GND         0V supply
      6  SDA,SDI,SDO I2C.data (or SPI.data.in, or 3-wire.data.out)
      7  SA0,SDO     I2C.device.id (or SPI.data.out)
      8  CS          Mode (high=I2C, low=SPI)
      9  INT 2       Inertial interrupt 2
      10 Reserved    Connect to GND
      11 INT 1       Inertial interrupt 1
      12 GND         0V supply
      13 GND         0V supply
      14 Vdd         Power supply
      15 Reserved    Connect to Vdd
      16 GND         0V supply

IrDA (NXP SC16IS750, 24pin HVQFN24 package)

      1  I  /RESET     Reset
      2  I  XTAL1      Crystal input, or external clock input
      3  O  XTAL2      Crystal output, or clock output
      4  -  Vdd        Supply
      5  I  I2C,/SPI   Interface mode select
      6  I  /CS,A0     SPI chip select, or I2C device id
      7  I  SI,A1      SPI data in, or I2C device id
      8  O  SO         SPI data out
      9  I  SCL,SCLK   SPI clk, or I2C clk
      10 IO SDA        I2C data
      11 O  /IRQ       Interrupt
      12 IO GPIO0      I/O
      13 IO GPIO1      I/O
      14 IO GPIO2      I/O
      15 IO GPIO3      I/O
      16 -  Vss        GND
      17 IO GPIO4,/DSR I/O, or modem data set ready
      18 IO GPIO5,/DTR I/O, or modem data terminal ready
      19 IO GPIO6,/CD  I/O, or modem carrier detect
      20 IO GPIO7,/RI  I/O, or modem ring indicator
      21 O  /RTS       UART request to send
      22 I  /CTS       UART clear to send
      23 O  TX         UART data out
      24 I  RX         UART data in

NFC (Broadcom BCM2079x)
Caution: below is for 34pin BCM20793S (which is NOT used in New3DS)
Caution: actual New3DS uses 32pin BCM20791 (maybe similar, but has only 32pin)
The pinout difference might be as simple as omitting the two N/C pins, or some of the four EEPROM/VDD_EE pins...?

      1  VDDSWP_IN     Platform UICC supply in
      2  VDDSWP_OUT0   UICC supply out
      3  SWPIO_0       SWP I/O 0
      4  SWPIO_1       SWP I/O 1
      5  VDDSWP_OUT1   Supply to embedded secure element
      6  VDD_ADC       Decoupling, need linking to VDDC_CAP via target PCB
      7  NFC_WAKE      Signal from host to the BCM20793S
      8  TM2           ATE test mode (grounded for normal operation)
      9  VDD_EEPROM_IN 1.8V power input to the co-packaged EEPROM (get from VDD_EE)
      10 HOST_WAKE     Interrupt signal from the BCM20793S to host
      11 CLK_REQ       Clock request
      12 UART_TXD      UART transmit       ;or BSC/I2C_SDA, or SPI_MOSI
      13 VDDIO         I/O supply; externally regulated
      14 UART_RTS_N    UART ready to send  ;or BSC/I2C_SCL, or SPI_MISO
      15 SPI_INT       Host interface select (Low=UART, High=BSC/I2C, NC=SPI+IRQ)
      16 UART_CTS_N    UART clear to send  ;or BSC/I2C_REQ(?), or SPI_CS
      17 UART_RXD      UART receive        ;or SPI_CLK
      18 N/C           No connect
      19 XTAL_XON      Crystal N
      20 XTAL_XOP      Crystal P/clock reference input
      21 VDD_XTAL      Decoupling, need linking to VDDC_CAP via target PCB
      22 LPO           Frequency selection, strap high or low (see page 45)
      23 VDD_VCO       Decoupling, need linking to VDDC_CAP via target PCB
      24 VDDC_CAP      Decoupling, links VDDADC, VDD_XTAL, VDD_VCO via target PCB
      25 REG_PU        Regulator power control from host
      26 VBAT          Battery supply
      27 VDDA_CAP      Analog LDO supply decoupling (1.88V/2.5V)
      28 TX2           Coil output 2
      29 TX1           Coil output 1
      30 VDD_ANT       Rectifier output, external cap
      31 N/C           Do not connect
      32 VDD_EE        Output 1.8V supply voltage (to be linked to VDD_SE_IN)
      33 SDA (eeprom)  BSC/I2C data internally connected to co-packaged EEPROM
      34 SCL (eeprom)  BSC/I2C clock internally connected to co-packaged EEPROM

EEPROM: CAT24C64 EEPROM Die
Unknown if the EEPROM exists in New3DS, it might require REG_PU wake or so? Or the EEPROM is accessed INTERNALLY by the NFC chip (and the two EXTERNAL I2C/BSC EEPROM pins or meant to be used only optionally, for factory/init/test or so?) (that way the NFC could be also accessed via SPI/UART whilst internally talking to the I2C/BSC EEPROM).
MAX17040 Fuel Gauge (used in Old3DS)

      1 CTG   Connect to GND
      2 CELL  Battery Voltage Input
      3 VDD   Power Supply
      4 GND   Ground
      5 SEO   External 32kHz clock enable
      6 EO    External 32kHz clock
      7 SCL   I2C Clock
      8 SDA   I2C Data

MAX17048 Fuel Gauge (this, or something similar(?) is used in New3DS)

       ______________________
      |o                     |
      |  CTG  CELL VDD  GND  |
      |  SDA  SCL  QRST /ALRT|
      |______________________|

ARM CPU Reference

General ARM7TDMI Information
ARM CPU Overview
ARM CPU Register Set
ARM CPU Flags & Condition Field (cond)
ARM CPU 26bit Memory Interface
ARM CPU Exceptions
ARM CPU Memory Alignments
ARM 32bit Instruction Set (ARM Code)
ARM Instruction Summary
ARM Opcodes: Branch and Branch with Link (B, BL, BX, BLX, SWI, BKPT)
ARM Opcodes: Data Processing (ALU)
ARM Opcodes: Multiply and Multiply-Accumulate (MUL, MLA)
ARM Opcodes: Special ARM9 Instructions (CLZ, QADD/QSUB)
ARM Opcodes: Special ARM11 Instructions (Misc)
ARM Opcodes: Special ARM11 Instructions (SIMD)
ARM Opcodes: PSR Transfer (MRS, MSR)
ARM Opcodes: Memory: Single Data Transfer (LDR, STR, PLD)
ARM Opcodes: Memory: Halfword, Doubleword, and Signed Data Transfer
ARM Opcodes: Memory: Block Data Transfer (LDM, STM)
ARM Opcodes: Memory: Single Data Swap (SWP)
ARM Opcodes: Coprocessor Instructions (MRC/MCR, LDC/STC, CDP, MCRR/MRRC)
ARM 16bit Instruction Set (THUMB Code)
When operating in THUMB state, cut-down 16bit opcodes are used.
THUMB is supported on T-variants of ARMv4 and up, ie. ARMv4T, ARMv5T, etc.
THUMB Instruction Summary
THUMB Opcodes: Register Operations (ALU, BX)
THUMB Opcodes: Memory Load/Store (LDR/STR)
THUMB Opcodes: Memory Addressing (ADD PC/SP)
THUMB Opcodes: Memory Multiple Load/Store (PUSH/POP and LDM/STM)
THUMB Opcodes: Jumps and Calls
THUMB Opcodes: New THUMB Opcodes in ARM11
Note
Switching between ARM and THUMB state can be done by using the Branch and Exchange (BX) instruction.
Further Information
ARM Pseudo Instructions and Directives
ARM CP15 System Control Coprocessor
ARM Vector Floating-point Unit (VFP)
ARM CPU Instruction Cycle Times
ARM CPU Versions
ARM CPU Data Sheet

ARM CPU Overview

The ARM7TDMI is a 32bit RISC (Reduced Instruction Set Computer) CPU, designed by ARM (Advanced RISC Machines), and designed for both high performance and low power consumption.
Fast Execution
Depending on the CPU state, all opcodes are sized 32bit or 16bit (that's counting both the opcode bits and its parameters bits) providing fast decoding and execution. Additionally, pipelining allows - (a) one instruction to be executed while (b) the next instruction is decoded and (c) the next instruction is fetched from memory - all at the same time.
Data Formats
The CPU manages to deal with 8bit, 16bit, and 32bit data, that are called:

       8bit - Byte
      16bit - Halfword
      32bit - Word

The two CPU states
As mentioned above, two CPU states exist:
- ARM state: Uses the full 32bit instruction set (32bit opcodes)
- THUMB state: Uses a cutdown 16bit instruction set (16bit opcodes)
Regardless of the opcode-width, both states are using 32bit registers, allowing 32bit memory addressing as well as 32bit arithmetic/logical operations.
When to use ARM state
Basically, there are two advantages in ARM state:

     - Each single opcode provides more functionality, resulting
       in faster execution when using a 32bit bus memory system
       (such like opcodes stored in GBA Work RAM).
     - All registers R0-R15 can be accessed directly.

The downsides are:

     - Not so fast when using 16bit memory system
       (but it still works though).
     - Program code occupies more memory space.

When to use THUMB state
There are two major advantages in THUMB state:

     - Faster execution up to approx 160% when using a 16bit bus
       memory system (such like opcodes stored in GBA GamePak ROM).
     - Reduces code size, decreases memory overload down to approx 65%.

The disadvantages are:

     - Not as multi-functional opcodes as in ARM state, so it will
       be sometimes required use more than one opcode to gain a
       similar result as for a single opcode in ARM state.
     - Most opcodes allow only registers R0-R7 to be used directly.

Combining ARM and THUMB state
Switching between ARM and THUMB state is done by a normal branch (BX) instruction which takes only a handful of cycles to execute (allowing to change states as often as desired - with almost no overload).
Also, as both ARM and THUMB are using the same register set, it is possible to pass data between ARM and THUMB mode very easily.
The best memory & execution performance can be gained by combining both states: THUMB for normal program code, and ARM code for timing critical subroutines (such like interrupt handlers, or complicated algorithms).
Note: ARM and THUMB code cannot be executed simultaneously.
Automatic state changes
Beside for the above manual state switching by using BX instructions, the following situations involve automatic state changes:
- CPU switches to ARM state when executing an exception
- User switches back to old state when leaving an exception

ARM CPU Register Set

Overview
The following table shows the ARM7TDMI register set which is available in each mode. There's a total of 37 registers (32bit each), 31 general registers (Rxx) and 6 status registers (xPSR).
Note that only some registers are 'banked', for example, each mode has it's own R14 register: called R14, R14_fiq, R14_svc, etc. for each mode respectively.
However, other registers are not banked, for example, each mode is using the same R0 register, so writing to R0 will always affect the content of R0 in other modes also.

      System/User FIQ       Supervisor Abort     IRQ       Undefined
      --------------------------------------------------------------
      R0          R0        R0         R0        R0        R0
      R1          R1        R1         R1        R1        R1
      R2          R2        R2         R2        R2        R2
      R3          R3        R3         R3        R3        R3
      R4          R4        R4         R4        R4        R4
      R5          R5        R5         R5        R5        R5
      R6          R6        R6         R6        R6        R6
      R7          R7        R7         R7        R7        R7
      --------------------------------------------------------------
      R8          R8_fiq    R8         R8        R8        R8
      R9          R9_fiq    R9         R9        R9        R9
      R10         R10_fiq   R10        R10       R10       R10
      R11         R11_fiq   R11        R11       R11       R11
      R12         R12_fiq   R12        R12       R12       R12
      R13 (SP)    R13_fiq   R13_svc    R13_abt   R13_irq   R13_und
      R14 (LR)    R14_fiq   R14_svc    R14_abt   R14_irq   R14_und
      R15 (PC)    R15       R15        R15       R15       R15
      --------------------------------------------------------------
      CPSR        CPSR      CPSR       CPSR      CPSR      CPSR
      --          SPSR_fiq  SPSR_svc   SPSR_abt  SPSR_irq  SPSR_und
      --------------------------------------------------------------

R0-R12 Registers (General Purpose Registers)
These thirteen registers may be used for whatever general purposes. Basically, each is having same functionality and performance, ie. there is no 'fast accumulator' for arithmetic operations, and no 'special pointer register' for memory addressing.
However, in THUMB mode only R0-R7 (Lo registers) may be accessed freely, while R8-R12 and up (Hi registers) can be accessed only by some instructions.
R13 Register (SP)
This register is used as Stack Pointer (SP) in THUMB state. While in ARM state the user may decided to use R13 and/or other register(s) as stack pointer(s), or as general purpose register.
As shown in the table above, there's a separate R13 register in each mode, and (when used as SP) each exception handler may (and MUST!) use its own stack.
R14 Register (LR)
This register is used as Link Register (LR). That is, when calling to a sub-routine by a Branch with Link (BL) instruction, then the return address (ie. old value of PC) is saved in this register.
Storing the return address in the LR register is obviously faster than pushing it into memory, however, as there's only one LR register for each mode, the user must manually push its content before issuing 'nested' subroutines.
Same happens when an exception is called, PC is saved in LR of new mode.
Note: In ARM mode, R14 may be used as general purpose register also, provided that above usage as LR register isn't required.
R15 Register (PC)
R15 is always used as program counter (PC). Note that when reading R15, this will usually return a value of PC+nn because of read-ahead (pipelining), whereas 'nn' depends on the instruction and on the CPU state (ARM or THUMB).
CPSR and SPSR (Program Status Registers) (ARMv3 and up)
The current condition codes (flags) and CPU control bits are stored in the CPSR register. When an exception arises, the old CPSR is saved in the SPSR of the respective exception-mode (much like PC is saved in LR).
For details refer to chapter about CPU Flags.

ARM CPU Flags & Condition Field (cond)

ARM Condition Field {cond}
The opcode {cond} suffixes can be used for conditionally executed code based on the C,N,Z,V flags in CPSR register. For example: BEQ = Branch if Equal, MOVMI = Move if Signed.
In ARM mode, {cond} can be used with all opcodes (except for a few newer ARMv5 instructions: BKPT, PLD, CDP2, LDC2, MCR2, MRC2, STC2, and BLX_imm are nonconditional; however BLX_reg can be conditional).
In THUMB mode, {cond} can be used only for branch opcodes.

      Code Suffix Flags         Meaning
      0:   EQ     Z=1           equal (zero) (same)
      1:   NE     Z=0           not equal (nonzero) (not same)
      2:   CS/HS  C=1           unsigned higher or same (carry set)
      3:   CC/LO  C=0           unsigned lower (carry cleared)
      4:   MI     N=1           signed negative (minus)
      5:   PL     N=0           signed positive or zero (plus)
      6:   VS     V=1           signed overflow (V set)
      7:   VC     V=0           signed no overflow (V cleared)
      8:   HI     C=1 and Z=0   unsigned higher
      9:   LS     C=0 or Z=1    unsigned lower or same
      A:   GE     N=V           signed greater or equal
      B:   LT     N<>V          signed less than
      C:   GT     Z=0 and N=V   signed greater than
      D:   LE     Z=1 or N<>V   signed less or equal
      E:   AL     -             always (the "AL" suffix can be omitted)
      F:   NV     -             never (ARMv1,v2 only) (Reserved ARMv3 and up)

Execution Time: If condition=false: 1S cycle. Otherwise: as specified for the respective opcode.
Current Program Status Register (CPSR)

      Bit   Expl.
      31    N - Sign Flag       (0=Not Signed, 1=Signed)               ;\
      30    Z - Zero Flag       (0=Not Zero, 1=Zero)                   ; Condition
      29    C - Carry Flag      (0=Borrow/No Carry, 1=Carry/No Borrow) ; Code Flags
      28    V - Overflow Flag   (0=No Overflow, 1=Overflow)            ;/
      27    Q - Sticky Overflow (1=Sticky Overflow, ARMv5TE and up only)
      26-8  Reserved            (For future use) - Do not change manually!
      7     I - IRQ disable     (0=Enable, 1=Disable)                     ;\
      6     F - FIQ disable     (0=Enable, 1=Disable)                     ; Control
      5     T - State Bit       (0=ARM, 1=THUMB) - Do not change manually!; Bits
      4-0   M4-M0 - Mode Bits   (See below)                               ;/

Bit 31-28: Condition Code Flags (N,Z,C,V)
These bits reflect results of logical or arithmetic instructions. In ARM mode, it is often optionally whether an instruction should modify flags or not, for example, it is possible to execute a SUB instruction that does NOT modify the condition flags.
In ARM state, all instructions can be executed conditionally depending on the settings of the flags, such like MOVEQ (Move if Z=1). While In THUMB state, only Branch instructions (jumps) can be made conditionally.
Bit 27: Sticky Overflow Flag (Q) - ARMv5TE and ARMv5TExP and up only
Used by QADD, QSUB, QDADD, QDSUB, SMLAxy, and SMLAWy only. These opcodes set the Q-flag in case of overflows, but leave it unchanged otherwise. The Q-flag can be tested/reset by MSR/MRS opcodes only.
Bit 27-8: Reserved Bits (except Bit 27 on ARMv5TE and up, see above)
These bits are reserved for possible future implementations. For best forwards compatibility, the user should never change the state of these bits, and should not expect these bits to be set to a specific value.
Bit 7-0: Control Bits (I,F,T,M4-M0)
These bits may change when an exception occurs. In privileged modes (non-user modes) they may be also changed manually.
The interrupt bits I and F are used to disable IRQ and FIQ interrupts respectively (a setting of "1" means disabled).
The T Bit signalizes the current state of the CPU (0=ARM, 1=THUMB), this bit should never be changed manually - instead, changing between ARM and THUMB state must be done by BX instructions.
The Mode Bits M4-M0 contain the current operating mode.

      Binary Hex Dec  Expl.
      0xx00b 00h 0  - Old User       ;\26bit Backward Compatibility modes
      0xx01b 01h 1  - Old FIQ        ; (supported only on ARMv3, except ARMv3G,
      0xx10b 02h 2  - Old IRQ        ; and on some non-T variants of ARMv4)
      0xx11b 03h 3  - Old Supervisor ;/
      10000b 10h 16 - User (non-privileged)
      10001b 11h 17 - FIQ
      10010b 12h 18 - IRQ
      10011b 13h 19 - Supervisor (SWI)
      10111b 17h 23 - Abort
      11011b 1Bh 27 - Undefined
      11111b 1Fh 31 - System (privileged 'User' mode) (ARMv4 and up)

Writing any other values into the Mode bits is not allowed.
Saved Program Status Registers (SPSR_<mode>)
Additionally to above CPSR, five Saved Program Status Registers exist:
SPSR_fiq, SPSR_svc, SPSR_abt, SPSR_irq, SPSR_und
Whenever the CPU enters an exception, the current status register (CPSR) is copied to the respective SPSR_<mode> register. Note that there is only one SPSR for each mode, so nested exceptions inside of the same mode are allowed only if the exception handler saves the content of SPSR in memory.
For example, for an IRQ exception: IRQ-mode is entered, and CPSR is copied to SPSR_irq. If the interrupt handler wants to enable nested IRQs, then it must first push SPSR_irq before doing so.

ARM CPU 26bit Memory Interface

The 26bit Memory Interface was used by ARMv1 and ARMv2. The 32bit interface is used by ARMv3 and newer, however, 26bit backward compatibility was included in all ARMv3 (except ARMv3G), and optionally in some non-T variants of ARMv4.
Format of R15 in 26bit Mode (Program Counter Register)

      Bit   Name     Expl.
      31-28 N,Z,C,V  Flags (Sign, Zero, Carry, Overflow)
      27-26 I,F      Interrupt Disable bits (IRQ, FIQ) (1=Disable)
      25-2  PC       Program Counter, 24bit, Step 4 (64M range)
      1-0   M1,M0    Mode (0=User, 1=FIQ, 2=IRQ, 3=Supervisor)

Branches with +/-32M range wrap the PC register, and can reach all 64M memory.
Reading from R15
If R15 is specified in bit16-19 of an opcode, then NZCVIF and M0,1 are masked (zero), otherwise the full 32bits are used.
Writing to R15
ALU opcodes with S=1, and LDM opcodes with PSR=1 can write to all 32bits in R15 (in 26bit mode, that is allowed even in user mode, though it does then affect only NZCF, not the write protected IFMM bits ???), other opcodes which write to R15 will modify only the program counter bits. Also, special CMP/CMN/TST/TEQ{P} opcodes can be used to write to the PSR bits in R15 without modifying the PC bits.
Exceptions
SWIs, Reset, Data/Prefetch Aborts and Undefined instructions enter Supervisor mode. Interrupts enter IRQ and FIQ mode. Additionally, a special 26bit Address Exception exists, which enters Supervisor mode on accesses to memory addresses>=64M as follows:

      R14_svc = PC ($+8, including old PSR bits)
      M1,M0 = 11b = supervisor mode, F=same, I=1, PC=14h,
      to continue at the fault location, return by SUBS PC,LR,8.

32bit CPUs with 26bit compatibility mode can be configured to switch into 32bit mode when encountering exceptions.

ARM CPU Exceptions

Exception Vectors
The following are the exception vectors in memory. That is, when an exception arises, CPU is switched into ARM state, and the program counter (PC) is loaded by the respective address.

      Address  Prio  Exception                  Mode on Entry      Interrupt Flags
      BASE+00h 1     Reset                      Supervisor (_svc)  I=1, F=1
      BASE+04h 7     Undefined Instruction      Undefined  (_und)  I=1, F=unchanged
      BASE+08h 6     Software Interrupt (SWI)   Supervisor (_svc)  I=1, F=unchanged
      BASE+0Ch 5     Prefetch Abort             Abort      (_abt)  I=1, F=unchanged
      BASE+10h 2     Data Abort                 Abort      (_abt)  I=1, F=unchanged
      BASE+14h ??    Address Exceeds 26bit      Supervisor (_svc)  I=1, F=unchanged
      BASE+18h 4     Normal Interrupt (IRQ)     IRQ        (_irq)  I=1, F=unchanged
      BASE+1Ch 3     Fast Interrupt (FIQ)       FIQ        (_fiq)  I=1, F=1

BASE is normally 00000000h, but may be optionally FFFF0000h in some ARM CPUs. Priority for simultaneously occuring exceptions ranges from Prio=1=Highest to Prio=7=Lowest.
As there's only space for one ARM opcode at each of the above addresses, it'd be usually recommended to deposit a Branch opcode into each vector, which'd then redirect to the actual exception handlers address.
Actions performed by CPU when entering an exception

      - R14_<new mode>=PC+nn   ;save old PC, ie. return address
      - SPSR_<new mode>=CPSR   ;save old flags
      - CPSR new T,M bits      ;set to T=0 (ARM state), and M4-0=new mode
      - CPSR new I bit         ;IRQs disabled (I=1), done by ALL exceptions
      - CPSR new F bit         ;FIQs disabled (F=1), done by Reset and FIQ only
      - PC=exception_vector    ;see table above

Above "PC+nn" depends on the type of exception. Basically, in ARM state that nn-offset is caused by pipelining, and in THUMB state an identical ARM-style 'offset' is generated (even though the 'base address' may be only halfword-aligned).
Required user-handler actions when returning from an exception
Restore any general registers (R0-R14) which might have been modified by the exception handler. Use return-instruction as listed in the respective descriptions below, this will both restore PC and CPSR - that automatically involves that the old CPU state (THUMB or ARM) as well as old state of FIQ and IRQ disable flags are restored.
As mentioned above (see action on entering...), the return address is always saved in ARM-style format, so that exception handler may use the same return-instruction, regardless of whether the exception has been generated from inside of ARM or THUMB state.
FIQ (Fast Interrupt Request)
This interrupt is generated by a LOW level on the nFIQ input. It is supposed to process timing critical interrupts at a high priority, as fast as possible.
Additionally to the common banked registers (R13_fiq,R14_fiq), five extra banked registers (R8_fiq-R12_fiq) are available in FIQ mode. The exception handler may freely access these registers without modifying the main programs R8-R12 registers (and without having to save that registers on stack).
In privileged (non-user) modes, FIQs may be also manually disabled by setting the F Bit in CPSR.
IRQ (Normal Interrupt Request)
This interrupt is generated by a LOW level on the nIRQ input. Unlike FIQ, the IRQ mode is not having its own banked R8-R12 registers.
IRQ is having lower priority than FIQ, and IRQs are automatically disabled when a FIQ exception becomes executed. In privileged (non-user) modes, IRQs may be also manually disabled by setting the I Bit in CPSR.
To return from IRQ Mode (continuing at following opcode):

      SUBS PC,R14,4   ;both PC=R14_irq-4, and CPSR=SPSR_irq

Software Interrupt
Generated by a software interrupt instruction (SWI). Recommended to request a supervisor (operating system) function. The SWI instruction may also contain a parameter in the 'comment field' of the opcode:
In case that your main program issues SWIs from both inside of THUMB and ARM states, then your exception handler must separate between 24bit comment fields in ARM opcodes, and 8bit comment fields in THUMB opcodes (if necessary determine old state by examining T Bit in SPSR_svc); However, in Little Endian mode, you could use only the most significant 8bits of the 24bit ARM comment field (as done in the GBA, for example) - the exception handler could then process the BYTE at [R14-2], regardless of whether it's been called from ARM or THUMB state.
To return from Supervisor Mode (continuing at following opcode):

      MOVS PC,R14   ;both PC=R14_svc, and CPSR=SPSR_svc

Note: Like all other exceptions, SWIs are always executed in ARM state, no matter whether it's been caused by an ARM or THUMB state SWI instruction.
Undefined Instruction Exception (supported by ARMv3 and up)
This exception is generated when the CPU comes across an instruction which it cannot handle. Most likely signalizing that the program has locked up, and that an errormessage should be displayed.
However, it might be also used to emulate custom functions, ie. as an additional 'SWI' instruction (which'd use R14_und and SPSR_und though, and it'd thus allow to execute the Undefined Instruction handler from inside of Supervisor mode without having to save R14_svc and SPSR_svc).
To return from Undefined Mode (continuing at following opcode):

      MOVS PC,R14   ;both PC=R14_und, and CPSR=SPSR_und

Note that not all unused opcodes are necessarily producing an exception, for example, an ARM state Multiply instruction with Bit6=1 would be blindly accepted as 'legal' opcode.
Abort (supported by ARMv3 and up)
Aborts (page faults) are mostly supposed for virtual memory systems (ie. not used in GBA, as far as I know), otherwise they might be used just to display an error message. Two types of aborts exists:
- Prefetch Abort (occurs during an instruction prefetch)
- Prefetch Abort (also occurs on BKPT opcodes, ARMv5 and up)
- Data Abort (occurs during a data access)
A virtual memory systems abort handler would then most likely determine the fault address: For prefetch abort that's just "R14_abt-4". For Data abort, the THUMB or ARM instruction at "R14_abt-8" needs to be 'disassembled' in order to determine the addressed data in memory.
The handler would then fix the error by loading the respective memory page into physical memory, and then retry to execute the SAME instruction again, by returning as follows:

      prefetch abort: SUBS PC,R14,#4   ;PC=R14_abt-4, and CPSR=SPSR_abt
      data abort:     SUBS PC,R14,#8   ;PC=R14_abt-8, and CPSR=SPSR_abt

Separate exception vectors for prefetch/data abort exists, each should use the respective return instruction as shown above.
Address Exceeds 26bit
This exception can occur only on old ARM CPUs with 26bit address scheme (or in 26bit backwards compatibility mode).
Reset
Forces PC=VVVV0000h, and forces control bits of CPSR to T=0 (ARM state), F=1 and I=1 (disable FIQ and IRQ), and M4-0=10011b (Supervisor mode).

ARM CPU Memory Alignments

The CPU does NOT support accessing mis-aligned addresses (which would be rather slow because it'd have to merge/split that data into two accesses).
When reading/writing code/data to/from memory, Words and Halfwords must be located at well-aligned memory address, ie. 32bit words aligned by 4, and 16bit halfwords aligned by 2.
Mis-aligned STR,STRH,STM,LDM,LDRD,STRD,PUSH,POP (forced align)
The mis-aligned low bit(s) are ignored, the memory access goes to a forcibly aligned (rounded-down) memory address.
For LDRD/STRD, it isn't clearly defined if the address must be aligned by 8 (on the NDS, align-4 seems to be okay) (align-8 may be required on other CPUs with 64bit databus).
Mis-aligned LDR,SWP (rotated read)
Reads from forcibly aligned address "addr AND (NOT 3)", and does then rotate the data as "ROR (addr AND 3)*8". That effect is internally used by LDRB and LDRH opcodes (which do then mask-out the unused bits).
The SWP opcode works like a combination of LDR and STR, that means, it does read-rotated, but does write-unrotated.
Mis-aligned LDRH,LDRSH (does or does not do strange things)
On ARM9 aka ARMv5 aka NDS9:

      LDRH Rd,[odd]   -->  LDRH Rd,[odd-1]        ;forced align
      LDRSH Rd,[odd]  -->  LDRSH Rd,[odd-1]       ;forced align

On ARM7 aka ARMv4 aka NDS7/GBA:

      LDRH Rd,[odd]   -->  LDRH Rd,[odd-1] ROR 8  ;read to bit0-7 and bit24-31
      LDRSH Rd,[odd]  -->  LDRSB Rd,[odd]         ;sign-expand BYTE value

Mis-aligned PC/R15 (branch opcodes, or MOV/ALU/LDR with Rd=R15)
For ARM code, the low bits of the target address should be usually zero, otherwise, R15 is forcibly aligned by clearing the lower two bits.
For THUMB code, the low bit of the target address may/should/must be set, the bit is (or is not) interpreted as thumb-bit (depending on the opcode), and R15 is then forcibly aligned by clearing the lower bit.
In short, R15 will be always forcibly aligned, so mis-aligned branches won't have effect on subsequent opcodes that use R15, or [R15+disp] as operand.

ARM Instruction Summary

Modification of CPSR flags is optional for all {S} instructions.
Logical ALU Operations

      Instruction                      Cycles   Flags  Expl.
      MOV{cond}{S} Rd,Op2              1S+x+y    NZc-  Rd = Op2
      MVN{cond}{S} Rd,Op2              1S+x+y    NZc-  Rd = NOT Op2
      ORR{cond}{S} Rd,Rn,Op2           1S+x+y    NZc-  Rd = Rn OR Op2
      EOR{cond}{S} Rd,Rn,Op2           1S+x+y    NZc-  Rd = Rn XOR Op2
      AND{cond}{S} Rd,Rn,Op2           1S+x+y    NZc-  Rd = Rn AND Op2
      BIC{cond}{S} Rd,Rn,Op2           1S+x+y    NZc-  Rd = Rn AND NOT Op2
      TST{cond}{P}    Rn,Op2           1S+x      NZc-  Void = Rn AND Op2
      TEQ{cond}{P}    Rn,Op2           1S+x      NZc-  Void = Rn XOR Op2

Add x=1I cycles if Op2 shifted-by-register. Add y=1S+1N cycles if Rd=R15.
Carry flag affected only if Op2 contains a non-zero shift amount.
Arithmetic ALU Operations

      Instruction                      Cycles   Flags  Expl.
      ADD{cond}{S} Rd,Rn,Op2           1S+x+y    NZCV  Rd = Rn+Op2
      ADC{cond}{S} Rd,Rn,Op2           1S+x+y    NZCV  Rd = Rn+Op2+Cy
      SUB{cond}{S} Rd,Rn,Op2           1S+x+y    NZCV  Rd = Rn-Op2
      SBC{cond}{S} Rd,Rn,Op2           1S+x+y    NZCV  Rd = Rn-Op2+Cy-1
      RSB{cond}{S} Rd,Rn,Op2           1S+x+y    NZCV  Rd = Op2-Rn
      RSC{cond}{S} Rd,Rn,Op2           1S+x+y    NZCV  Rd = Op2-Rn+Cy-1
      CMP{cond}{P}    Rn,Op2           1S+x      NZCV  Void = Rn-Op2
      CMN{cond}{P}    Rn,Op2           1S+x      NZCV  Void = Rn+Op2

Add x=1I cycles if Op2 shifted-by-register. Add y=1S+1N cycles if Rd=R15.
Multiply

      Instruction                      Cycles   Flags  Expl.
      MUL{cond}{S} Rd,Rm,Rs            1S+mI     NZx-  Rd = Rm*Rs
      MLA{cond}{S} Rd,Rm,Rs,Rn         1S+mI+1I  NZx-  Rd = Rm*Rs+Rn
      UMULL{cond}{S} RdLo,RdHi,Rm,Rs   1S+mI+1I  NZx-  RdHiLo = Rm*Rs
      UMLAL{cond}{S} RdLo,RdHi,Rm,Rs   1S+mI+2I  NZx-  RdHiLo = Rm*Rs+RdHiLo
      SMULL{cond}{S} RdLo,RdHi,Rm,Rs   1S+mI+1I  NZx-  RdHiLo = Rm*Rs
      SMLAL{cond}{S} RdLo,RdHi,Rm,Rs   1S+mI+2I  NZx-  RdHiLo = Rm*Rs+RdHiLo
      SMLAxy{cond}  Rd,Rm,Rs,Rn     ARMv5TE(xP)  ----q Rd=HalfRm*HalfRs+Rn
      SMLAWy{cond}  Rd,Rm,Rs,Rn     ARMv5TE(xP)  ----q Rd=(Rm*HalfRs)/10000h+Rn
      SMULWy{cond}  Rd,Rm,Rs        ARMv5TE(xP)  ----  Rd=(Rm*HalfRs)/10000h
      SMLALxy{cond} RdLo,RdHi,Rm,Rs ARMv5TE(xP)  ----  RdHiLo=RdHiLo+HalfRm*HalfRs
      SMULxy{cond}  Rd,Rm,Rs        ARMv5TE(xP)  ----  Rd=HalfRm*HalfRs

Memory Load/Store

      Instruction                      Cycles    Flags  Expl.
      LDR{cond}{B}{T} Rd,<Address>     1S+1N+1I+y ----  Rd=[Rn+/-<offset>]
      LDR{cond}H      Rd,<Address>     1S+1N+1I+y ----  Load Unsigned halfword
      LDR{cond}D      Rd,<Address>                ----  Load Dword ARMv5TE
      LDR{cond}SB     Rd,<Address>     1S+1N+1I+y ----  Load Signed byte
      LDR{cond}SH     Rd,<Address>     1S+1N+1I+y ----  Load Signed halfword
      LDM{cond}{amod} Rn{!},<Rlist>{^} nS+1N+1I+y ----  Load Multiple
      STR{cond}{B}{T} Rd,<Address>     2N         ----  [Rn+/-<offset>]=Rd
      STR{cond}H      Rd,<Address>     2N         ----  Store halfword
      STR{cond}D      Rd,<Address>                ----  Store Dword ARMv5TE
      STM{cond}{amod} Rn{!},<Rlist>{^} (n-1)S+2N  ----  Store Multiple
      SWP{cond}{B}    Rd,Rm,[Rn]       1S+2N+1I   ----  Rd=[Rn], [Rn]=Rm
      PLD             <Address>        1S         ----  Prepare Cache ARMv5TE

For LDR/LDM, add y=1S+1N if Rd=R15, or if R15 in Rlist.
Jumps, Calls, CPSR Mode, and others

      Instruction                  Cycles  Flags  Expl.
      B{cond}   label              2S+1N    ----  PC=$+8+/-32M
      BL{cond}  label              2S+1N    ----  PC=$+8+/-32M, LR=$+4
      BX{cond}  Rn                 2S+1N    ----  PC=Rn, T=Rn.0 (THUMB/ARM)
      BLX{cond} Rn                 2S+1N    ----  PC=Rn, T=Rn.0, LR=PC+4, ARM9
      BLX       label              2S+1N    ----  PC=PC+$+/-32M, LR=$+4, T=1, ARM9
      MRS{cond} Rd,Psr             1S       ----  Rd=Psr
      MSR{cond} Psr{_field},Op     1S      (psr)  Psr[field]=Op
      SWI{cond} Imm24bit           2S+1N    ----  PC=8, ARM Svc mode, LR=$+4
      BKPT      Imm16bit           ???      ----  PC=C, ARM Abt mode, LR=$+4 ARM9
      The Undefined Instruction    2S+1I+1N ----  PC=4, ARM Und mode, LR=$+4
      cond=false                   1S       ----  Any opcode with condition=false
      NOP                          1S       ----  R0=R0

      CLZ{cond} Rd,Rm              ???      ----    Count Leading Zeros ARMv5
      QADD{cond} Rd,Rm,Rn                   ----q   Rd=Rm+Rn       ARMv5TE(xP)
      QSUB{cond} Rd,Rm,Rn                   ----q   Rd=Rm-Rn       ARMv5TE(xP)
      QDADD{cond} Rd,Rm,Rn                  ----q   Rd=Rm+Rn*2     ARMv5TE(xP)
      QDSUB{cond} Rd,Rm,Rn                  ----q   Rd=Rm-Rn*2     ARMv5TE(xP)

Coprocessor Functions (if any)

      Instruction                         Cycles  Flags  Expl.
      CDP{cond} Pn,<cpopc>,Cd,Cn,Cm{,<cp>} 1S+bI   ----  Coprocessor specific
      STC{cond}{L} Pn,Cd,<Address>         (n-1)S+2N+bI  [address] = CRd
      LDC{cond}{L} Pn,Cd,<Address>         (n-1)S+2N+bI  CRd = [address]
      MCR{cond} Pn,<cpopc>,Rd,Cn,Cm{,<cp>} 1S+bI+1C      CRn = Rn {<op> CRm}
      MRC{cond} Pn,<cpopc>,Rd,Cn,Cm{,<cp>} 1S+(b+1)I+1C  Rn = CRn {<op> CRm}
      CDP2,STC2,LDC2,MCR2,MRC2 - ARMv5 Extensions similar above, without {cond}
      MCRR{cond} Pn,<cpopc>,Rd,Rn,Cm  ;write Rd,Rn to coproc ARMv5TE
      MRRC{cond} Pn,<cpopc>,Rd,Rn,Cm  ;read Rd,Rn from coproc ARMv5TE

ARM Binary Opcode Format

      |..3 ..................2 ..................1 ..................0|
      |1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0|
      |_Cond__|0_0_0|___Op__|S|__Rn___|__Rd___|__Shift__|Typ|0|__Rm___| DataProc
      |_Cond__|0_0_0|___Op__|S|__Rn___|__Rd___|__Rs___|0|Typ|1|__Rm___| DataProc
      |_Cond__|0_0_1|___Op__|S|__Rn___|__Rd___|_Shift_|___Immediate___| DataProc
      |_Cond__|0_0_1_1_0_0_1_0_0_0_0_0_1_1_1_1_0_0_0_0|_____Hint______| ARM11:Hint
      |_Cond__|0_0_1_1_0|P|1|0|_Field_|__Rd___|_Shift_|___Immediate___| PSR Imm
      |_Cond__|0_0_0_1_0|P|L|0|_Field_|__Rd___|0_0_0_0|0_0_0_0|__Rm___| PSR Reg
      |_Cond__|0_0_0_1_0_0_1_0_1_1_1_1_1_1_1_1_1_1_1_1|0_0|L|1|__Rn___| BX,BLX
      |1_1_1_0|0_0_0_1_0_0_1_0|_____immediate_________|0_1_1_1|_immed_| ARM9:BKPT
      |_Cond__|0_0_0_1_0_1_1_0_1_1_1_1|__Rd___|1_1_1_1|0_0_0_1|__Rm___| ARM9:CLZ
      |_Cond__|0_0_0_1_0|Op_|0|__Rn___|__Rd___|0_0_0_0|0_1_0_1|__Rm___| ARM9:QALU
      |_Cond__|0_0_0_0_0_0|A|S|__Rd___|__Rn___|__Rs___|1_0_0_1|__Rm___| Multiply
      |_Cond__|0_0_0_0_0_1_0_0|_RdHi__|_RdLo__|__Rs___|1_0_0_1|__Rm___| ARM11:UMAAL
      |_Cond__|0_0_0_0_1|U|A|S|_RdHi__|_RdLo__|__Rs___|1_0_0_1|__Rm___| MulLong
      |_Cond__|0_0_0_1_0|Op_|0|Rd/RdHi|Rn/RdLo|__Rs___|1|y|x|0|__Rm___| MulHalfARM9
      |_Cond__|0_0_0_1_0|B|0_0|__Rn___|__Rd___|0_0_0_0|1_0_0_1|__Rm___| TransSwp12
      |_Cond__|0_0_0_1_1|_Op__|__Rn___|__Rd___|1_1_1_1|1_0_0_1|__Rm___| ARM11:LDREX
      |_Cond__|0_0_0|P|U|0|W|L|__Rn___|__Rd___|0_0_0_0|1|S|H|1|__Rm___| TransReg10
      |_Cond__|0_0_0|P|U|1|W|L|__Rn___|__Rd___|OffsetH|1|S|H|1|OffsetL| TransImm10
      |_Cond__|0_1_0|P|U|B|W|L|__Rn___|__Rd___|_________Offset________| TransImm9
      |_Cond__|0_1_1|P|U|B|W|L|__Rn___|__Rd___|__Shift__|Typ|0|__Rm___| TransReg9
      |_Cond__|0_1_1|________________xxx____________________|1|__xxx__| Undefined
      |_Cond__|0_1_1|Op_|x_x_x_x_x_x_x_x_x_x_x_x_x_x_x_x_x_x|1|x_x_x_x| ARM11:Media
      |1_1_1_1_0_1_0_1_0_1_1_1_1_1_1_1_1_1_1_1_0_0_0_0_0_0_0_1_1_1_1_1| ARM11:CLREX
      |_Cond__|1_0_0|P|U|S|W|L|__Rn___|__________Register_List________| BlockTrans
      |_Cond__|1_0_1|L|___________________Offset______________________| B,BL,BLX
      |_Cond__|1_1_0|P|U|N|W|L|__Rn___|__CRd__|__CP#__|____Offset_____| CoDataTrans
      |_Cond__|1_1_0_0_0_1_0|L|__Rn___|__Rd___|__CP#__|_CPopc_|__CRm__| CoRR ARM9
      |_Cond__|1_1_1_0|_CPopc_|__CRn__|__CRd__|__CP#__|_CP__|0|__CRm__| CoDataOp
      |_Cond__|1_1_1_0|CPopc|L|__CRn__|__Rd___|__CP#__|_CP__|1|__CRm__| CoRegTrans
      |_Cond__|1_1_1_1|_____________Ignored_by_Processor______________| SWI

ARM11 SIMD Media instructions (ARM11/ARMv6) (formerly Undef opcode space)

      |..3 ..................2 ..................1 ..................0|
      |1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0|
      |_Cond__|0_1_1|0_0|_Op__|__Rn___|__Rd___|1_1_1_1|_Op__|1|__Rm___| ParaAddSub
      |_Cond__|0_1_1|0_1|0_0_0|__Rn___|__Rd___|_shift___|x|0_1|__Rm___| HalfPack
      |_Cond__|0_1_1|0_1|U|1|____sat__|__Rd___|_shift___|x|0_1|__Rm___| WordSat
      |_Cond__|0_1_1|0_1|U|1_0|__sat__|__Rd___|1_1_1_1|0_0_1_1|__Rm___| ParaHalfSat
      |_Cond__|0_1_1|0_1|0_1_1|1_1_1_1|__Rd___|1_1_1_1|0_0_1_1|__Rm___| RevWord
      |_Cond__|0_1_1|0_1|0_1_1|1_1_1_1|__Rd___|1_1_1_1|1_0_1_1|__Rm___| RevPackHalf
      |_Cond__|0_1_1|0_1|1_1_1|1_1_1_1|__Rd___|1_1_1_1|1_0_1_1|__Rm___| RevSignHalf
      |_Cond__|0_1_1|0_1|0_0_0|__Rn___|__Rd___|1_1_1_1|1_0_1_1|__Rm___| SelectBytes
      |_Cond__|0_1_1|0_1|_Op__|__Rn___|__Rd___|rot|0_0|0_1_1_1|__Rm___| Extend U/S
      |_Cond__|0_1_1|1_0|_Op__|Rd/RdHi|Rn/RdLo|__Rs___|_Op__|1|__Rm___| Multiplies
      |_Cond__|0_1_1|1_1|0_0_0|__Rd___|__Rn___|__Rs___|0_0_0_1|__Rm___| DiffSum
      |_Cond__|0_1_1|1_1|0_0_0|__Rd___|1_1_1_1|__Rs___|0_0_0_1|__Rm___| DiffSumAcc
      |_Cond__|0_1_1_1_1_1_1_1|x_x_x_x_x_x_x_x_x_x_x_x|1_1_1_1|x_x_x_x| Undef

ARM Opcodes: Branch and Branch with Link (B, BL, BX, BLX, SWI, BKPT)

Branch and Branch with Link (B, BL, BLX_imm)
Branch (B) is supposed to jump to a subroutine. Branch with Link is meant to be used to call to a subroutine, return address is then saved in R14.

      Bit    Expl.
      31-28  Condition (must be 1111b for BLX)
      27-25  Must be "101" for this instruction
      24     Opcode (0-1) (or Halfword Offset for BLX)
              0: B{cond} label    ;branch            PC=PC+8+nn*4
              1: BL{cond} label   ;branch/link       PC=PC+8+nn*4, LR=PC+4
              H: BLX label ;ARM9  ;branch/link/thumb PC=PC+8+nn*4+H*2, LR=PC+4, T=1
      23-0   nn - Signed Offset, step 4      (-32M..+32M in steps of 4)

Branch with Link can be used to 'call' to a sub-routine, which may then 'return' by MOV PC,R14 for example.
Execution Time: 2S + 1N
Return: No flags affected.
Branch and Exchange (BX, BLX_reg)

      Bit    Expl.
      31-28  Condition
      27-8   Must be "0001.0010.1111.1111.1111" for this instruction
      7-4    Opcode
              0001b: BX{cond}  Rn    ;PC=Rn, T=Rn.0   (ARMv4T and ARMv5 and up)
              0010b: BXJ{cond} Rn    ;Change to Jazelle bytecode (ARMv5TEJ and up)
              0011b: BLX{cond} Rn    ;PC=Rn, T=Rn.0, LR=PC+4     (ARMv5 and up)
      3-0    Rn - Operand Register  (R0-R14)

Switching to THUMB Mode: Set Bit 0 of the value in Rn to 1, program continues then at Rn-1 in THUMB mode.
Using BLX R14 is possible (sets PC=Old_LR, and New_LR=retadr).
Using BX R15 acts as BX $+8 (tested and working on ARM7/ARM9, although it isn't officially defined as predictable behaviour).
Execution Time: 2S + 1N
Return: No flags affected.
Notes on BXJ (Branch or change to Jazelle bytecode state):
If Jazelle is suppored/enabled: Executes Java bytecode at address R14
If Jazelle is NOT suppored/enabled: Behaves exactly same as BX Rn
That is, R14 is the byte code address, and Rn is an ARM/THUMB error handler.
Supported on ARMv5TEJ and ARMv6 and up.
Branch via ALU, LDR, LDM
Most ALU, LDR, LDM opcodes can also change PC/R15.
Software Interrupt (SWI/BKPT) (svc/abt exceptions)
SWI supposed for calls to the operating system - Enter Supervisor mode (SVC) in ARM state. BKPT intended for debugging - enters Abort mode in ARM state via Prefetch Abort vector.

      Bit    Expl.
      31-28  Condition (must be 1110b for BKPT, ie. Condition=always)
      27-24  Opcode
              1111b: SWI{cond} nn   ;software interrupt
              0001b: BKPT      nn   ;breakpoint (ARMv5 and up)
      For SWI:
       23-0   nn - Comment Field, ignored by processor (24bit value)
      For BKPT:
       23-20  Must be 0010b for BKPT
       19-8   nn - upper 12bits of comment field, ignored by processor
       7-4    Must be 0111b for BKPT
       3-0    nn - lower 4bits of comment field, ignored by processor

Execution Time: 2S+1N
The exception handler may interprete the SWI Comment Field by examining the lower 24bit of the 32bit opcode opcode at [R14_svc-4]. If your are also using SWI's from inside of THUMB, then the SWI handler must examine the T Bit SPSR_svc in order to determine whether it's been a THUMB SWI - and if so, examine the lower 8bit of the 16bit opcode opcode at [R14_svc-2].
For Returning from SWI use "MOVS PC,R14", that instruction does restore both PC and CPSR, ie. PC=R14_svc, and CPSR=SPSR_svc.
Nesting SWIs: SPSR_svc and R14_svc should be saved on stack before either invoking nested SWIs, or (if the IRQ handler uses SWIs) before enabling IRQs.
Execution SWI/BKPT:

      R14_svc=PC+4     R14_abt=PC+4   ;save return address
      SPSR_svc=CPSR    SPSR_abt=CPSR  ;save CPSR flags
      CPSR=<changed>   CPSR=<changed> ;Enter svc/abt, ARM state, IRQs disabled
      PC=VVVV0008h     PC=VVVV000Ch   ;jump to SWI/PrefetchAbort vector address

Undefined Instruction (und exception)

      Bit    Expl.
      31-28  Condition
      27-25  Must be 011b for this instruction
      24-5   Reserved for future use
      4      Must be 1b for this instruction
      3-0    Reserved for future use

No assembler mnemonic exists, following bitstreams are (not) reserved.

      cond011xxxxxxxxxxxxxxxxxxxx1xxxx - reserved for future use (except below).
      cond01111111xxxxxxxxxxxx1111xxxx - free for user.

Note: ARMv6 does use the "reserved for future" space for the new SIMD opcodes (but still has the "free for user" space available as "undefined").
Execution time: 2S+1I+1N.

ARM Opcodes: Data Processing (ALU)

Opcode Format

      Bit    Expl.
      31-28  Condition
      27-26  Must be 00b for this instruction
      25     I - Immediate 2nd Operand Flag (0=Register, 1=Immediate)
      24-21  Opcode (0-Fh)               ;*=Arithmetic, otherwise Logical
               0: AND{cond}{S} Rd,Rn,Op2    ;AND logical       Rd = Rn AND Op2
               1: EOR{cond}{S} Rd,Rn,Op2    ;XOR logical       Rd = Rn XOR Op2
               2: SUB{cond}{S} Rd,Rn,Op2 ;* ;subtract          Rd = Rn-Op2
               3: RSB{cond}{S} Rd,Rn,Op2 ;* ;subtract reversed Rd = Op2-Rn
               4: ADD{cond}{S} Rd,Rn,Op2 ;* ;add               Rd = Rn+Op2
               5: ADC{cond}{S} Rd,Rn,Op2 ;* ;add with carry    Rd = Rn+Op2+Cy
               6: SBC{cond}{S} Rd,Rn,Op2 ;* ;sub with carry    Rd = Rn-Op2+Cy-1
               7: RSC{cond}{S} Rd,Rn,Op2 ;* ;sub cy. reversed  Rd = Op2-Rn+Cy-1
               8: TST{cond}{P}    Rn,Op2    ;test            Void = Rn AND Op2
               9: TEQ{cond}{P}    Rn,Op2    ;test exclusive  Void = Rn XOR Op2
               A: CMP{cond}{P}    Rn,Op2 ;* ;compare         Void = Rn-Op2
               B: CMN{cond}{P}    Rn,Op2 ;* ;compare neg.    Void = Rn+Op2
               C: ORR{cond}{S} Rd,Rn,Op2    ;OR logical        Rd = Rn OR Op2
               D: MOV{cond}{S} Rd,Op2       ;move              Rd = Op2
               E: BIC{cond}{S} Rd,Rn,Op2    ;bit clear         Rd = Rn AND NOT Op2
               F: MVN{cond}{S} Rd,Op2       ;not               Rd = NOT Op2
      20     S - Set Condition Codes (0=No, 1=Yes) (Must be 1 for opcode 8-B)
      19-16  Rn - 1st Operand Register (R0..R15) (including PC=R15)
                  Must be 0000b for MOV/MVN.
      15-12  Rd - Destination Register (R0..R15) (including PC=R15)
                  Must be 0000b (or 1111b) for CMP/CMN/TST/TEQ{P}.
      When above Bit 25 I=0 (Register as 2nd Operand)
        When below Bit 4 R=0 - Shift by Immediate
          11-7   Is - Shift amount   (1-31, 0=Special/See below)
        When below Bit 4 R=1 - Shift by Register
          11-8   Rs - Shift register (R0-R14) - only lower 8bit 0-255 used
          7      Reserved, must be zero  (otherwise multiply or LDREX or undefined)
        6-5    Shift Type (0=LSL, 1=LSR, 2=ASR, 3=ROR)
        4      R - Shift by Register Flag (0=Immediate, 1=Register)
        3-0    Rm - 2nd Operand Register (R0..R15) (including PC=R15)
      When above Bit 25 I=1 (Immediate as 2nd Operand)
        11-8   Is - ROR-Shift applied to nn (0-30, in steps of 2)
        7-0    nn - 2nd Operand Unsigned 8bit Immediate

Second Operand (Op2)
This may be a shifted register, or a shifted immediate. See Bit 25 and 11-0.
Unshifted Register: Specify Op2 as "Rm", assembler converts to "Rm,LSL#0".
Shifted Register: Specify as "Rm,SSS#Is" or "Rm,SSS Rs" (SSS=LSL/LSR/ASR/ROR).
Immediate: Specify as 32bit value, for example: "#000NN000h", assembler should automatically convert into "#0NNh,ROR#0ssh" as far as possible (ie. as far as a section of not more than 8bits of the immediate is non-zero).
Zero Shift Amount (Shift Register by Immediate, with Immediate=0)

      LSL#0: No shift performed, ie. directly Op2=Rm, the C flag is NOT affected.
      LSR#0: Interpreted as LSR#32, ie. Op2 becomes zero, C becomes Bit 31 of Rm.
      ASR#0: Interpreted as ASR#32, ie. Op2 and C are filled by Bit 31 of Rm.
      ROR#0: Interpreted as RRX#1 (RCR), like ROR#1, but Op2 Bit 31 set to old C.

In source code, LSR#32, ASR#32, and RRX#1 should be specified as such - attempts to specify LSR#0, ASR#0, or ROR#0 will be internally converted to LSL#0 by the assembler.
Using R15 (PC)
When using R15 as Destination (Rd), note below CPSR description and Execution time description.
When using R15 as operand (Rm or Rn), the returned value depends on the instruction: PC+12 if I=0,R=1 (shift by register), otherwise PC+8 (shift by immediate).
Returned CPSR Flags
If S=1, Rd<>R15, logical operations (AND,EOR,TST,TEQ,ORR,MOV,BIC,MVN):

      V=not affected
      C=carryflag of shift operation (not affected if LSL#0 or Rs=00h)
      Z=zeroflag of result
      N=signflag of result (result bit 31)

If S=1, Rd<>R15, arithmetic operations (SUB,RSB,ADD,ADC,SBC,RSC,CMP,CMN):

      V=overflowflag of result
      C=carryflag of result
      Z=zeroflag of result
      N=signflag of result (result bit 31)

IF S=1, with unused Rd bits=1111b, {P} opcodes (CMPP/CMNP/TSTP/TEQP):

      R15=result  ;modify PSR bits in R15, ARMv2 and below only.
      In user mode only N,Z,C,V bits of R15 can be changed.
      In other modes additionally I,F,M1,M0 can be changed.
      The PC bits in R15 are left unchanged in all modes.

If S=1, Rd=R15; should not be used in user mode:

      CPSR = SPSR_<current mode>
      PC = result
      For example: MOVS PC,R14  ;return from SWI (PC=R14_svc, CPSR=SPSR_svc).

If S=0: Flags are not affected (not allowed for CMP,CMN,TEQ,TST).
The instruction "MOV R0,R0" is used as "NOP" opcode in 32bit ARM state.
Execution Time: (1+p)S+rI+pN. Whereas r=1 if I=0 and R=1 (ie. shift by register); otherwise r=0. And p=1 if Rd=R15; otherwise p=0.

ARM Opcodes: Multiply and Multiply-Accumulate (MUL, MLA)

Opcode Format

      Bit    Expl.
      31-28  Condition
      27-25  Must be 000b for this instruction
      24-21  Opcode
              0000b: MUL{cond}{S}   Rd,Rm,Rs        ;Rd=Rm*Rs     ;\works as both
              0001b: MLA{cond}{S}   Rd,Rm,Rs,Rn     ;Rd=Rm*Rs+Rn  ;/signed+unsigned
              0010b: UMAAL{cond}    RdLo,RdHi,Rm Rs ;RdHiLo=Rm*Rs+RdHi+RdLo;\un-
              0100b: UMULL{cond}{S} RdLo,RdHi,Rm,Rs ;RdHiLo=Rm*Rs          ; signed
              0101b: UMLAL{cond}{S} RdLo,RdHi,Rm,Rs ;RdHiLo=Rm*Rs+RdHiLo   ;/
              0110b: SMULL{cond}{S} RdLo,RdHi,Rm,Rs ;RdHiLo=Rm*Rs
              0111b: SMLAL{cond}{S} RdLo,RdHi,Rm,Rs ;RdHiLo=Rm*Rs+RdHiLo
              1000b: SMLAxy{cond}   Rd,Rm,Rs,Rn     ;Rd=HalfRm*HalfRs+Rn
              1001b: SMLAWy{cond}   Rd,Rm,Rs,Rn     ;Rd=(Rm*HalfRs)/10000h+Rn
              1001b: SMULWy{cond}   Rd,Rm,Rs        ;Rd=(Rm*HalfRs)/10000h
              1010b: SMLALxy{cond}  RdLo,RdHi,Rm,Rs ;RdHiLo=RdHiLo+HalfRm*HalfRs
              1011b: SMULxy{cond}   Rd,Rm,Rs        ;Rd=HalfRm*HalfRs
      20     S - Set Condition Codes (0=No, 1=Yes) (Must be 0 for Halfword & UMAAL)
      19-16  Rd (or RdHi) - Destination Register (R0-R14)
      15-12  Rn (or RdLo) - Accumulate Register  (R0-R14) (Set to 0000b if unused)
      11-8   Rs - Operand Register               (R0-R14)
      For Non-Halfword Multiplies
        7-4  Must be 1001b for these instructions
      For Halfword Multiplies
        7    Must be 1 for these instructions
        6    y - Rs Top/Bottom flag (0=B=Lower 16bit, 1=T=Upper 16bit)
        5    x - Rm Top/Bottom flag (as above), or 0 for SMLAW, or 1 for SMULW
        4    Must be 0 for these instructions
      3-0    Rm - Operand Register               (R0-R14)

Multiply and Multiply-Accumulate (MUL, MLA)
Restrictions: Rd may not be same as Rm. Rd,Rn,Rs,Rm may not be R15.
Note: Only the lower 32bit of the internal 64bit result are stored in Rd, thus no sign/zero extension is required and MUL and MLA can be used for both signed and unsigned calculations!
Execution Time: 1S+mI for MUL, and 1S+(m+1)I for MLA. Whereas 'm' depends on whether/how many most significant bits of Rs are all zero or all one. That is m=1 for Bit 31-8, m=2 for Bit 31-16, m=3 for Bit 31-24, and m=4 otherwise.
Flags (if S=1): Z=zeroflag, N=signflag, C=destroyed (ARMv4 and below) or C=not affected (ARMv5 and up), V=not affected. MUL/MLA supported by ARMv2 and up.
Multiply Long and Multiply-Accumulate Long (MULL, MLAL)
Optionally supported, INCLUDED in ARMv3M, EXCLUDED in ARMv4xM/ARMv5xM.
Restrictions: RdHi,RdLo,Rm must be different registers. R15 may not be used.
Execution Time: 1S+(m+1)I for MULL, and 1S+(m+2)I for MLAL. Whereas 'm' depends on whether/how many most significant bits of Rs are "all zero" (UMULL/UMLAL) or "all zero or all one" (SMULL,SMLAL). That is m=1 for Bit31-8, m=2 for Bit31-16, m=3 for Bit31-24, and m=4 otherwise.
Flags (if S=1): Z=zeroflag, N=signflag, C=destroyed (ARMv4 and below) or C=not affected (ARMv5 and up), V=destroyed??? (ARMv4 and below???) or V=not affected (ARMv5 and up).
Signed Halfword Multiply (SMLAxy,SMLAWy,SMLALxy,SMULxy,SMULWy)
Supported by E variants of ARMv5 and up, ie. ARMv5TE(xP).
Q-flag gets set on 32bit SMLAxy/SMLAWy addition overflows, however, the result is NOT truncated (as it'd be done with QADD opcodes).
Q-flag is NOT affected on (rare) 64bit SMLALxy addition overflows.
SMULxy/SMULWy cannot overflow, and thus leave Q-flag unchanged as well.
NZCV-flags are not affected by Halfword multiplies.
Execution Time: 1S+Interlock (SMULxy,SMLAxy,SMULWx,SMLAWx)
Execution Time: 1S+1I+Interlock (SMLALxy)
Unsigned Multiply Accumulate Accumulate Long (UMAAL)
Multiply with two 32bit additions, supposed to be used for cryptography.
Flags are not affected.
ARMv6 and above.

ARM Opcodes: Special ARM9 Instructions (CLZ, QADD/QSUB)

Count Leading Zeros (CLZ)

      Bit    Expl.
      31-28  Condition
      27-16  Must be 0001.0110.1111b for this instruction
             Opcode (fixed)
               CLZ{cond} Rd,Rm  ;Rd=Number of leading zeros in Rm
      15-12  Rd - Destination Register              (R0-R14)
      11-4   Must be 1111.0001b for this instruction
      3-0    Rm - Source Register                   (R0-R14)

CLZ supported by ARMv5 and up. Execution time: 1S.
Return: No Flags affected. Rd=0..32.
Opcode Format (QADD/QSUB)

      Bit    Expl.
      31-28  Condition
      27-24  Must be 0001b for this instruction
      23-20  Opcode
              0000b: QADD{cond}  Rd,Rm,Rn    ;Rd=Rm+Rn
              0010b: QSUB{cond}  Rd,Rm,Rn    ;Rd=Rm-Rn
              0100b: QDADD{cond} Rd,Rm,Rn    ;Rd=Rm+Rn*2 (doubled)
              0110b: QDSUB{cond} Rd,Rm,Rn    ;Rd=Rm-Rn*2 (doubled)
      19-16  Rn - Second Source Register            (R0-R14)
      15-12  Rd - Destination Register              (R0-R14)
      11-4   Must be 00000101b for this instruction
      3-0    Rm - First Source Register             (R0-R14)

Supported by E variants of ARMv5 and up, ie. ARMv5TE(xP).
Execution time: 1S+Interlock.
Results truncated to signed 32bit range in case of overflows, with the Q-flag being set (and being left unchanged otherwise). NZCV flags are not affected.
Note: Rn*2 is internally processed first, and may get truncated - even if the final result would fit into range.

ARM Opcodes: Special ARM11 Instructions (Misc)

Load/Store Byte/Halfword/Doubleword Exclusive (LDREX/STREX)

      Bit    Expl.
      31-28  Condition
      27-23  Must be 00011b for this instruction
      22-20  Opcode
               0: STREX{cond}  Rd, Rm, [Rn]  ;[Rn]=Rm, Rd=flag       ;32bit
               1: LDREX{cond}  Rd, [Rn]      ;Rd=[Rm]                ;32bit
               2: STREXD{cond} Rd, Rm, [Rn]  ;[Rn]=Rm,Rm+1, Rd=flag  ;64bit
               3: LDREXD{cond} Rd, [Rn]      ;Rd,Rd+1=[Rm]           ;64bit
               4: STREXB{cond} Rd, Rm, [Rn]  ;[Rn]=Rm, Rd=flag       ;8bit
               5: LDREXB{cond} Rd, [Rn]      ;Rd=[Rm]                ;8bit
               6: STREXH{cond} Rd, Rm, [Rn]  ;[Rn]=Rm, Rd=flag       ;16bit
               7: LDREXH{cond} Rd, [Rn]      ;Rd=[Rm]                ;16bit
      19-16  Rn - Base Register                      (R0-R14)
      15-12  Rd - Destination Register               (R0-R14)
      11-4   Must be 1111.1001b for this instruction
      3-0    Rm - Source Register (1111b for LDREX)  (R0-R14)

For exclusive access to shared memory regions (ie. in dual-core CPUs?)
Unknown what "exclusive" means?
Return: No Flags affected.
ARMv6 and up supports LDREX/STREX (with 32bit operand).
ARMv6K and up supports LDREX/STREX{B|H|D} (with 8/16/64bit operand).
Clear Exclusive (CLREX)

      Bit    Expl.
      31-0   Opcode 1111.0101.0111.1111.1111.0000.0001.1111b for CLREX

Supported on ARMv6K and up.
Hint (TrueNOP, YIELD, WFE, WFI, SEV)

      Bit    Expl.
      31-28  Condition (should be always 0Eh=Always for NOP)
      27-8   Must be 0011.0010.0000.1111.0000b
      7-0    Opcode/Hint
               00h: TrueNOP      ;no operation
               01h: YIELD{cond}
               02h: WFE{cond}    ;wait for event
               03h: WFI{cond}    ;wait for interrupt
               04h: SEV{cond}    ;send event

Supported on ARMv6K and up.
Change Processor State aka CPSR Mode/Flags (CPS, CPSID, CPSIE)

      31-20  Must be 1111.0001.0000b
      19-17  Opcode
              001b: CPS   #<mode>           ;change mode
              100b: CPSIE {A}{I}{F}         ;interrupt bit(s) enable
              101b: CPSIE {A}{I}{F},#<mode> ;interrupt bit(s) enable & change mode
              110b: CPSID {A}{I}{F}         ;interrupt bit(s) disable
              111b: CPSID {A}{I}{F},#<mode> ;interrupt bit(s) disable & change mode
      16-9   Must be 0000.0000b
      8      Change A flag (what?) (0=No, 1=Yes)  ;\must be all zero for CPS,
      7      Change I flag         (0=No, 1=Yes)  ; must be at least one flag set
      6      Change F flag         (0=No, 1=Yes)  ;/for CPSID/CPSIE
      5      Must be 0
      4-0    Mode (00h..1Fh) (must be 00h if bit17=0)

Set Endianness for Data Access (SETEND)

      31-10  Fixed, 1111000100000001000000b
      9      Opcode/operand
              0: SETEND LE  ;clears the CPSR E bit
              1: SETEND BE  ;sets the CPSR E bit
      8-0    Fixed, 000000000b

Changes the byte order for data access to Big/Little endian. Does probably not affect opcode fetches, but probably affect all other memory including push/pop? Or affects "LDR" only?
Supported on ARMv6 and above.
Store Return State (SRS) (stores the R14 and SPSR of the current mode)
to the word at the specified address and the following word respectively. The address is determined from the banked version of R13 belonging to a specified mode.

      Syntax
      SRS<addressing_mode> #<mode>{!}   ;<-- original (pre-UAL)
      SRS<addressing_mode> sp!,#<mode>  ;<-- more common (UAL)

<addressing_mode>: Is similar to the <addressing_mode> in LDM and STM instructions, see Addressing Mode 4 - Load and Store Multiple on page A5-41, but with the following differences:
- The base register, Rn, is the banked version of R13 for the mode specified by <mode>, rather than the current mode.
- The number of registers to store is 2.
- The register list is {R14, SPSR}, with both R14 and the SPSR being the versions belonging to the current mode.
<mode> Specifies the number of the mode whose banked register is used as the base register for <addressing_mode>. The mode number is the 5-bit encoding of the chosen mode in a PSR, as described in The mode bits on page A2-14.
! If present, sets the W bit. This causes the instruction to write a modified value back to its base register, in a manner similar to that specified for Addressing Mode 4 - Load and Store Multiple on page A5-41. If ! is omitted, the W bit is 0 and the instruction does not change the base register.

      31-25  Fixed, 1111100b
      24     P
      23     U
      22     Fixed, 1
      21     W
      20     Fixed, 0 (store)
      19-5   Fixed, 110100000101000b
      4-0    mode

Supported on ARMv6 and above.
Return From Exception (RFE) (RFEDA, RFEDB, RFEIA, RFEIB)
loads the PC and the CPSR from the word at the specified address and the
following word respectively.

      Syntax
      RFE<addressing_mode> Rn{!}

<addressing_mode>: Is similar to the <addressing_mode> in LDM and STM instructions, see Addressing Mode 4 - Load and Store Multiple on page A5-41, but with the following differences:
- The number of registers to load is 2.
- The register list is {PC, CPSR}.
<Rn> Specifies the base register to be used by <addressing_mode>. If R15 is specified as the base register, the result is UNPREDICTABLE.
! If present, sets the W bit. This causes the instruction to write a modified value back to its base register, in a manner similar to that specified for Addressing Mode 4 - Load and Store Multiple on page A5-41. If ! is omitted, the W bit is 0 and the instruction does not change the base register.
While RFE supports different base registers, a general usage case is where Rn == sp (the stack pointer), held in R13. The instruction can then be used as the return method associated with instructions SRS and CPS. See New instructions to improve exception handling on page A2-28 for more details.

      31-25  Fixed, 1111100b
      24     P
      23     U
      22     Fixed, 0
      21     W
      20     Fixed, 1 (load)
      19-16  Rn
      15-0   Fixed, 0000101000000000b

Supported on ARMv6 and above.
SVC (formerly SWI)
SWI was renamed to SVC in new UAL syntax.
CPY
CPY Rd,Rm is an alias for MOV Rd,Rm (without flags affected).

      31-28  Condition
      27-16  Fixed, 000110100000
      15-12  Rd - Destination Register
      11-4   Fixed, 00000000
      3-0    Rm

The alias was invented in ARMv6 for THUMB and ARM code (apparently because pre-UAL THUMB syntax couldn't distinguish between MOV and MOVS) (ie. in ARM it's useless, but in THUMB it does allow using a formerly undocumented opcode).
ARMv6 and above.

ARM Opcodes: Special ARM11 Instructions (SIMD)

Sign Extend / Zero Extend, with optional Addition (SXT, UXT)

      31-28  Condition
      27-23  Fixed, 01101b
      22-20  Opcode:
              0: SXTAB16{cond} Rd, Rn, Rm{,ROR #imm} ;\
              2: SXTAB{cond}   Rd, Rn, Rm{,ROR #imm} ;
              3: SXTAH{cond}   Rd, Rn, Rm{,ROR #imm} ; with add
              4: UXTAB16{cond} Rd, Rn, Rm{,ROR #imm} ;
              6: UXTAB{cond}   Rd, Rn, Rm{,ROR #imm} ;
              7: UXTAH{cond}   Rd, Rn, Rm{,ROR #imm} ;/
              0: SXTB16{cond}  Rd,     Rm{,ROR #imm} ;\
              2: SXTB{cond}    Rd,     Rm{,ROR #imm} ;
              3: SXTH{cond}    Rd,     Rm{,ROR #imm} ; without add
              4: UXTB16{cond}  Rd,     Rm{,ROR #imm} ;
              6: UXTB{cond}    Rd,     Rm{,ROR #imm} ;
              7: UXTH{cond}    Rd,     Rm{,ROR #imm} ;/
      19-16  Rn - Addition Register (or 1111b when no addition)            (R0-R14)
      15-12  Rd - Destination Register                                     (R0-R14)
      11-10  Rotation (0=None/ROR#0, 1=ROR#8, 2=ROR#16, 3=ROR#24)
      9-4    Fixed, 000111b
      3-0    Rm - Source register (to be rotated/extracted from)           (R0-R14)

Supported on ARMv6 and above.
Select Bytes from 1st/2nd operand, depending on GE flags (SEL)
Syntax

      SEL{cond} Rd, Rn, Rm

Operation
if ConditionPassed(cond) then
Rd[7:0] = if GE[0] == 1 then Rn[7:0] else Rm[7:0]
Rd[15:8] = if GE[1] == 1 then Rn[15:8] else Rm[15:8]
Rd[23:16] = if GE[2] == 1 then Rn[23:16] else Rm[23:16]
Rd[31:24] = if GE[3] == 1 then Rn[31:24] else Rm[31:24]
Usage
Use SEL after instructions such as SADD8, SADD16, SSUB8, SSUB16, UADD8, UADD16, USUB8, USUB16, SADDSUBX, SSUBADDX, UADDSUBX and USUBADDX, that set the GE flags. For example, the following sequence of instructions sets each byte of Rd equal to the unsigned minimum of the corresponding bytes of Ra and Rb:

      USUB8 Rd, Ra, Rb
      SEL Rd, Rb, Ra

Notes
Specifying R15 for register Rd, Rm, or Rn has UNPREDICTABLE results.

      31-28  Condition
      27-20  Fixed, 01101000b
      19-16  Rn - First Source Register (8bit snippets used when GE bits = 1)
      15-12  Rd - Destination Register
      11-4   Fixed, 11111011b
      3-0    Rm - Second Source Register (8bit snippets used when GE bits = 0)

ARMv6 and above.
SADD16
SADD16 (Signed Add) performs two 16-bit signed integer additions. It sets the GE bits in the CPSR according to the results of the additions.
ARMv6 and above.
Operation
sum = Rn[15:0] + Rm[15:0] /* Signed addition */
Rd[15:0] = sum[15:0]
GE[1:0] = if sum >= 0 then 0b11 else 0
sum = Rn[31:16] + Rm[31:16] /* Signed addition */
Rd[31:16] = sum[15:0]
GE[3:2] = if sum >= 0 then 0b11 else 0

      31-28  Condition
      27-23  Fixed, 01100b
      22-20  Opcode, part 1:
              001b: for Sxx           (signed, with GE flags)
              010b: for Qxx           (signed, with saturation)
              011b: for SHxx          (signed, with halving)
              101b: for Uxx           (unsigned, with GE flags)
              110b: for UQxx          (unsigned, with saturation)
              111b: for UHxx          (unsigned, with halving)
      19-16  Rn - First Source Register                                    (R0-R14)
      15-12  Rd - Destination Register                                     (R0-R14)
      11-8   Fixed, 1111b
      7-5    Opcode, part 2:
              000b: xxADD16{cond}   Rd, Rn, Rm
              001b: xxADDSUBX{cond} Rd, Rn, Rm
              010b: xxSUBADDX{cond} Rd, Rn, Rm
              011b: xxSUB16{cond}   Rd, Rn, Rm
              100b: xxADD8{cond}    Rd, Rn, Rm
              111b: xxSUB8{cond}    Rd, Rn, Rm
      4      Fixed, 1
      3-0    Rm - Second Source register                                   (R0-R14)

SMLAD
SMLAD (Signed Multiply Accumulate Dual) performs two signed 16 x 16-bit multiplications. It adds the products to a 32-bit accumulate operand.
Optionally, you can exchange the halfwords of the second operand before performing the arithmetic. This produces top x bottom and bottom x top multiplication.
This instruction sets the Q flag if the accumulate operation overflows. Overflow cannot occur during the multiplications.
X Sets the X bit of the instruction to 1, and the multiplications are bottom x top and top x bottom.
If the X is omitted, sets the X bit to 0, and the multiplications are bottom x bottom and top x top.
<Rm> Specifies the register that contains the first operand.
<Rs> Specifies the register that contains the second operand.
<Rn> Specifies the register that contains the accumulate operand.

      31-28  Condition
      27-23  Fixed, 01110
      22-20  Opcode part 1 (part2 in bit7-6)
             Merged part1.part2:
               000.00: SMUAD{X}{cond}  Rd,Rm,Rs
               000.00: SMLAD{X}{cond}  Rd,Rm,Rs,Rn
               000.01: SMUSD{X}{cond}  Rd,Rm,Rs
               000.01: SMLSD{X}{cond}  Rd,Rm,Rs,Rn
               100.00: SMLALD{X}{cond} RdLo,RdHi,Rm,Rs
               100.01: SMLSLD{X}{cond} RdLo,RdHi,Rm,Rs
               101.00: SMMUL{R}{cond}  Rd,Rm,Rs        ;Rd=(Rm*Rs)/100000000h
               101.00: SMMLA{R}{cond}  Rd,Rm,Rs,Rn     ;Rd=(Rm*Rs)/100000000h+Rz
               101.11: SMMLS{R}{cond}  Rd,Rm,Rs,Rn     ;Rd=(Rm*Rs)/100000000h-Rz
      19-16  Rd or RdHi - Destination Register
      15-12  Rn or RdLo or unused (must be 0Fh for SMUAD/SMUSD/SMMUL)
      11-8   Rs
      7-6    Opcode part 2 (part1 in bit22-20, see there)
      5      X or R flag   (X=Exchange, R=Rounded)
      4      Fixed, 1
      3-0    Rm

ARMv6 and above.
Most significant word multiply
There are three signed 32-bit x 32-bit Multiply instructions that produce top 32-bit results:

      SMMUL Multiplies the 32-bit values of two registers together, and stores
            the top 32 bits of the signed 64-bit result in a third register.
      SMMLA Multiplies the 32-bit values of two registers together, extracts the
            top 32 bits, adds the 32-bit value from a third register, and stores
            the signed 32-bit result in a fourth register.
      SMMLS Multiplies the 32-bit value of two registers together, extracts the
            top 32 bits, subtracts this from a 32-bit value from a third
            register, and stores the signed 32-bit result in a fourth register.

The above three instructions do not affect any flags.
Dual halfword multiply
There are six dual, signed 16-bit x 16-bit Multiply instructions:

      SMUAD Multiplies the values of the top halfwords of two registers together,
            multiplies the values of the bottom halfwords of the same two
            registers together, adds the products, and stores the 32-bit result
            in a third register.
      SMUSD Multiplies the values of the top halfwords of two registers together,
            multiplies the values of the bottom halfwords of the same two
            registers together, subtracts one product from the other, and stores
            the 32-bit result in a third register.
      ---(descriptions below seem to be bugged, seem to describe 32bit SMMxx)---
      SMLAD Multiplies the 32-bit value of two registers together, extracts the
            top 32 bits, subtracts this from a 32-bit value from a third
            register, and stores the signed 32-bit result in a fourth register.
      SMLSD Multiplies the 32-bit values of two registers together, extracts the
            top 32 bits, adds the 32-bit value from a third register, and stores
            the signed 32-bit result in a fourth register.
      SMLALD Multiplies the 32-bit value of two registers together, extracts the
             top 32 bits, subtracts this from a 32-bit value from a third
             register, and stores the signed 32-bit result in a fourth register.
      SMLSLD Multiplies the 32-bit value of two registers together, extracts the
             top 32 bits, subtracts this from a 32-bit value from a third
             register, and stores the signed 32-bit result in a fourth register.

SMUAD, SMLAD, and SMLSLD can set the Q flag if overflow occurs in the operation. All other instructions do not affect any flags.
Signed/Unsigned Saturate (SSAT, USAT)
Saturates a 32bit value (with optional shift) to the specified range (of 1..32 bits).

      31-28  Condition
      27-21  Fixed, 0110101b: SSAT{cond} Rd, #<range>, Rm {,LSL/ASR #imm}
                    0110111b: USAT{cond} Rd, #<range>, Rm {,LSL/ASR #imm}
      20-16  Immediate: range-1 (0..31 = Saturate to 1..32 bits range)
      15-12  Rd - Destination Register
      11-7   shift_imm (1..31 for LSL/ASR#1..31, or 0 for LSL#0, or 0 for ASR#32)
      6      Shift type (0=LSL, 1=ASR) (note: really ASR, even "unsigned" USAT)
      5-4    Fixed, 01b
      3-0    Rm - Source Register

The Q flag is set if the operation saturates.
ARMv6 and above.
Signed/Unsigned Saturate on Halfwords (SSAT16, USAT16)
Saturates two 16bit values to the specified range (of 1..16 bits).

      31-28  Condition
      27-21  Fixed, 0110101b: SSAT16{cond} Rd, #<range>, Rm
                    0110111b: USAT16{cond} Rd, #<range>, Rm
      20     Fixed, 0
      19-16  Immediate: range-1 (0..15 = Saturate to 1..16 bits range)
      15-12  Rd - Destination Register
      11-4   Fixed, 11110011b
      3-0    Rm - Source Register

The Q flag is set if either halfword operation saturates.
ARMv6 and above.
Unsigned Sum of Absolute Differences, optional Accumulate (USAD8, USADA8)
Performs four unsigned 8bit subtractions, and adds the absolute values of the differences together.

      31-28  Condition
      27-20  Fixed, 01111000b
      19-16  Rd - Destination Register
      15-12  Rn (if any) (otherwise fixed, 1111)
               USAD8{cond}  Rd, Rm, Rs        ;without Rn   ;Rd=sum
               USADA8{cond} Rd, Rm, Rs, Rn    ;with Rn      ;Rd=sum + Rn
      11-8   Rs
      7-4    Fixed, 0001b
      3-0    Rm

ARMv6 and above.
Pack Halfword, Bottom-Top or Top-Bottom (PKHBT, PKHTB)
PKHBT (Pack Halfword Bottom Top) combines the bottom (least significant) halfword of its first operand with the top (most significant) halfword of its shifted second operand. The shift is a left shift, by any amount from 0 to 31.
<Rn> Specifies the register that contains the first operand. Bits[15:0] of this operand become bits[15:0] of the result of the operation.
<Rm> Specifies the register that contains the second operand. This is shifted left by the specified amount, then bits[31:16] of this operand become bits[31:16] of the result of the operation.
<shift_imm> Specifies the amount by which Rm is to be shifted left. This is a value from 0 to 31.
If the shift specifier is omitted, a left shift by 0 is used.
Operation
if ConditionPassed(cond) then
Rd[15:0] = Rn[15:0]
Rd[31:16] = (Rm Logical_Shift_Left shift_imm)[31:16]

      31-28  Condition
      27-20  Fixed, 01101000b
      19-16  Rn
      15-12  Rd - Destination Register
      11-7   shift_imm (0..31)
      6-4    Fixed, 001  PKHBT {cond} Rd, Rn, Rm {, LSL #<shift_imm>}
                    101  PKHTB {cond} Rd, Rn, Rm {, ASR #<shift_imm>}
      3-0    Rm

ARMv6 and above.
Reverse Byte Order for Big/Little-Endian Conversion (REV, REV16, REVSH)
Specifying R15 for register Rd or Rm has UNPREDICTABLE results.

      31-28  Condition
      27-23  Fixed, 01101b
      22     Opcode (with bit7)
              Bit22=0, Bit7=0: REV{cond}   Rd, Rm   ;reverse 32bit
              Bit22=0, Bit7=1: REV16{cond} Rd, Rm
              Bit22=1, Bit7=1: REVSH{cond} Rd, Rm
      21-16  Fixed, 111111b
      15-12  Rd - Destination Register
      11-8   Fixed, 1111b
      7      Opcode (with bit22, see there)
      6-4    Fixed, 011b
      3-0    Rm - Source Register

ARMv6 and above.

ARM Opcodes: PSR Transfer (MRS, MSR)

Opcode Format
These instructions occupy an unused area (TEQ,TST,CMP,CMN with S=0) of ALU opcodes.

      Bit    Expl.
      31-28  Condition
      27-26  Must be 00b for this instruction
      25     I - Immediate Operand Flag  (0=Register, 1=Immediate) (Zero for MRS)
      24-23  Must be 10b for this instruction
      22     Psr - Source/Destination PSR  (0=CPSR, 1=SPSR_<current mode>)
      21     Opcode
               0: MRS{cond} Rd,Psr          ;Rd = Psr
               1: MSR{cond} Psr{_field},Op  ;Psr[field] = Op
      20     Must be 0b for this instruction (otherwise TST,TEQ,CMP,CMN)
      For MRS:
        19-16   Must be 1111b for this instruction (otherwise SWP)
        15-12   Rd - Destination Register  (R0-R14)
        11-0    Not used, must be zero.
      For MSR:
        19      f  write to flags field     Bit 31-24 (aka _flg)
        18      s  write to status field    Bit 23-16 (reserved, don't change)
        17      x  write to extension field Bit 15-8  (reserved, don't change)
        16      c  write to control field   Bit 7-0   (aka _ctl)
        15-12   Not used, must be 1111b.
      For MSR Psr,Rm (I=0)
        11-4    Not used, must be zero. (otherwise BX)
        3-0     Rm - Source Register <op>  (R0-R14)
      For MSR Psr,Imm (I=1)
        11-8    Shift applied to Imm   (ROR in steps of two 0-30)
        7-0     Imm - Unsigned 8bit Immediate
        In source code, a 32bit immediate should be specified as operand.
        The assembler should then convert that into a shifted 8bit value.

MSR/MRS and CPSR/SPSR supported by ARMv3 and up.
ARMv2 and below contained PSR flags in R15, accessed by CMP/CMN/TST/TEQ{P}.
The field mask bits specify which bits of the destination Psr are write-able (or write-protected), one or more of these bits should be set, for example, CPSR_fsxc (aka CPSR aka CPSR_all) unlocks all bits (see below user mode restriction though).
Restrictions:
In non-privileged mode (user mode): only condition code bits of CPSR can be changed, control bits can't.
Only the SPSR of the current mode can be accessed; In User and System modes no SPSR exists.
The T-bit may not be changed; for THUMB/ARM switching use BX instruction.
Unused Bits in CPSR are reserved for future use and should never be changed (except for unused bits in the flags field).
Execution Time: 1S.
Note: The A22i assembler recognizes MOV as alias for both MSR and MRS because it is practically not possible to remember whether MSR or MRS was the load or store opcode, and/or whether it does load to or from the Psr register.

ARM Opcodes: Memory: Single Data Transfer (LDR, STR, PLD)

Opcode Format

      Bit    Expl.
      31-28  Condition (Must be 1111b for PLD)
      27-26  Must be 01b for this instruction
      25     I - Immediate Offset Flag (0=Immediate, 1=Shifted Register)
      24     P - Pre/Post (0=post; add offset after transfer, 1=pre; before trans.)
      23     U - Up/Down Bit (0=down; subtract offset from base, 1=up; add to base)
      22     B - Byte/Word bit (0=transfer 32bit/word, 1=transfer 8bit/byte)
      When above Bit 24 P=0 (Post-indexing, write-back is ALWAYS enabled):
        21     T - Memory Management (0=Normal, 1=Force non-privileged access)
      When above Bit 24 P=1 (Pre-indexing, write-back is optional):
        21     W - Write-back bit (0=no write-back, 1=write address into base)
      20     L - Load/Store bit (0=Store to memory, 1=Load from memory)
              0: STR{cond}{B}{T} Rd,<Address>   ;[Rn+/-<offset>]=Rd
              1: LDR{cond}{B}{T} Rd,<Address>   ;Rd=[Rn+/-<offset>]
             (1: PLD <Address> ;Prepare Cache for Load, see notes below)
              Whereas, B=Byte, T=Force User Mode (only for POST-Indexing)
      19-16  Rn - Base register               (R0..R15) (including R15=PC+8)
      15-12  Rd - Source/Destination Register (R0..R15) (including R15=PC+12)
      When above I=0 (Immediate as Offset)
        11-0   Unsigned 12bit Immediate Offset (0-4095, steps of 1)
      When above I=1 (Register shifted by Immediate as Offset)
        11-7   Is - Shift amount      (1-31, 0=Special/See below)
        6-5    Shift Type             (0=LSL, 1=LSR, 2=ASR, 3=ROR)
        4      Must be 0 (Reserved, see The Undefined Instruction)
        3-0    Rm - Offset Register   (R0..R14) (not including PC=R15)

Instruction Formats for <Address>
An expression which generates an address:

      <expression>                  ;an immediate used as address
      ;*** restriction: must be located in range PC+/-4095+8, if so,
      ;*** assembler will calculate offset and use PC (R15) as base.

Pre-indexed addressing specification:

      [Rn]                          ;offset = zero
      [Rn, <#{+/-}expression>]{!}   ;offset = immediate
      [Rn, {+/-}Rm{,<shift>} ]{!}   ;offset = register shifted by immediate

Post-indexed addressing specification:

      [Rn], <#{+/-}expression>      ;offset = immediate
      [Rn], {+/-}Rm{,<shift>}       ;offset = register shifted by immediate

Whereas...

      <shift>  immediate shift such like LSL#4, ROR#2, etc. (see ALU opcodes).
      {!}      exclamation mark ("!") indicates write-back (Rn will be updated).

Notes
Shift amount 0 has special meaning, as described for ALU opcodes.
When writing a word (32bit) to memory, the address should be word-aligned.
When reading a byte from memory, upper 24 bits of Rd are zero-extended.
LDR PC,<op> on ARMv4 leaves CPSR.T unchanged.
LDR PC,<op> on ARMv5 sets CPSR.T to <op> Bit0, (1=Switch to Thumb).
When reading a word from a halfword-aligned address (which is located in the middle between two word-aligned addresses), the lower 16bit of Rd will contain [address] ie. the addressed halfword, and the upper 16bit of Rd will contain [Rd-2] ie. more or less unwanted garbage. However, by isolating lower bits this may be used to read a halfword from memory. (Above applies to little endian mode, as used in GBA.)
In a virtual memory based environment (ie. not in the GBA), aborts (ie. page faults) may take place during execution, if so, Rm and Rn should not specify the same register when post-indexing is used, as the abort-handler might have problems to reconstruct the original value of the register.
Return: CPSR flags are not affected.
Execution Time: For normal LDR: 1S+1N+1I. For LDR PC: 2S+2N+1I. For STR: 2N.
PLD <Address> ;Prepare Cache for Load
PLD must use following settings cond=1111b, P=1, B=1, W=0, L=1, Rd=1111b, the address may not use post-indexing, and may not use writeback, the opcode is encoded identical as LDRNVB R15,<Address>.
PLD signalizes to the memory system that a specific memory address will be soon accessed, the memory system may use this hint to prepare caching/pipelining, aside from that, PLD does not have any affect to the program logic, and behaves identical as NOP.
PLD supported by ARMv5TE and up only, not ARMv5, not ARMv5TExP.

ARM Opcodes: Memory: Halfword, Doubleword, and Signed Data Transfer

Opcode Format

      Bit    Expl.
      31-28  Condition
      27-25  Must be 000b for this instruction
      24     P - Pre/Post (0=post; add offset after transfer, 1=pre; before trans.)
      23     U - Up/Down Bit (0=down; subtract offset from base, 1=up; add to base)
      22     I - Immediate Offset Flag (0=Register Offset, 1=Immediate Offset)
      When above Bit 24 P=0 (Post-indexing, write-back is ALWAYS enabled):
        21     Not used, must be zero (0)
      When above Bit 24 P=1 (Pre-indexing, write-back is optional):
        21     W - Write-back bit (0=no write-back, 1=write address into base)
      20     L - Load/Store bit (0=Store to memory, 1=Load from memory)
      19-16  Rn - Base register                (R0-R15) (Including R15=PC+8)
      15-12  Rd - Source/Destination Register  (R0-R15) (Including R15=PC+12)
      11-8   When above Bit 22 I=0 (Register as Offset):
               Not used. Must be 0000b
             When above Bit 22 I=1 (immediate as Offset):
               Immediate Offset (upper 4bits)
      7      Reserved, must be set (1)
      6-5    Opcode (0-3)
             When Bit 20 L=0 (Store) (and Doubleword Load/Store):
              0: Reserved for SWP instruction
              1: STR{cond}H  Rd,<Address>  ;Store halfword   [a]=Rd
              2: LDR{cond}D  Rd,<Address>  ;Load Doubleword  R(d)=[a], R(d+1)=[a+4]
              3: STR{cond}D  Rd,<Address>  ;Store Doubleword [a]=R(d), [a+4]=R(d+1)
             When Bit 20 L=1 (Load):
              0: Reserved.
              1: LDR{cond}H  Rd,<Address>  ;Load Unsigned halfword (zero-extended)
              2: LDR{cond}SB Rd,<Address>  ;Load Signed byte (sign extended)
              3: LDR{cond}SH Rd,<Address>  ;Load Signed halfword (sign extended)
      4      Reserved, must be set (1)
      3-0    When above Bit 22 I=0:
               Rm - Offset Register            (R0-R14) (not including R15)
             When above Bit 22 I=1:
               Immediate Offset (lower 4bits)  (0-255, together with upper bits)

STRH,LDRH,LDRSB,LDRSH supported on ARMv4 and up.
STRD/LDRD supported on ARMv5TE and up only, not ARMv5, not ARMv5TExP.
STRD/LDRD: base writeback: Rn should not be same as R(d) or R(d+1).
STRD: index register: Rm should not be same as R(d) or R(d+1).
STRD/LDRD: Rd must be an even numbered register (R0,R2,R4,R6,R8,R10,R12).
STRD/LDRD: Address must be double-word aligned (multiple of eight).
Instruction Formats for <Address>
An expression which generates an address:

      <expression>                  ;an immediate used as address
      ;*** restriction: must be located in range PC+/-255+8, if so,
      ;*** assembler will calculate offset and use PC (R15) as base.

Pre-indexed addressing specification:

      [Rn]                          ;offset = zero
      [Rn, <#{+/-}expression>]{!}   ;offset = immediate
      [Rn, {+/-}Rm]{!}              ;offset = register

Post-indexed addressing specification:

      [Rn], <#{+/-}expression>      ;offset = immediate
      [Rn], {+/-}Rm                 ;offset = register

Whereas...

      {!}      exclamation mark ("!") indicates write-back (Rn will be updated).

Return: No Flags affected.
Execution Time: For Normal LDR, 1S+1N+1I. For LDR PC, 2S+2N+1I. For STRH 2N.

ARM Opcodes: Memory: Block Data Transfer (LDM, STM)

Opcode Format

      Bit    Expl.
      31-28  Condition
      27-25  Must be 100b for this instruction
      24     P - Pre/Post (0=post; add offset after transfer, 1=pre; before trans.)
      23     U - Up/Down Bit (0=down; subtract offset from base, 1=up; add to base)
      22     S - PSR & force user bit (0=No, 1=load PSR or force user mode)
      21     W - Write-back bit (0=no write-back, 1=write address into base)
      20     L - Load/Store bit (0=Store to memory, 1=Load from memory)
              0: STM{cond}{amod} Rn{!},<Rlist>{^}  ;Store (Push)
              1: LDM{cond}{amod} Rn{!},<Rlist>{^}  ;Load  (Pop)
              Whereas, {!}=Write-Back (W), and {^}=PSR/User Mode (S)
      19-16  Rn - Base register                (R0-R14) (not including R15)
      15-0   Rlist - Register List
      (Above 'offset' is meant to be the number of words specified in Rlist.)

Return: No Flags affected.
Execution Time: For normal LDM, nS+1N+1I. For LDM PC, (n+1)S+2N+1I. For STM (n-1)S+2N. Where n is the number of words transferred.
Addressing Modes {amod}
The IB,IA,DB,DA suffixes directly specify the desired U and P bits:

      IB  increment before          ;P=1, U=1
      IA  increment after           ;P=0, U=1
      DB  decrement before          ;P=1, U=0
      DA  decrement after           ;P=0, U=0

Alternately, FD,ED,FA,EA could be used, mostly to simplify mnemonics for stack transfers.

      ED  empty stack, descending   ;LDM: P=1, U=1  ;STM: P=0, U=0
      FD  full stack,  descending   ;     P=0, U=1  ;     P=1, U=0
      EA  empty stack, ascending    ;     P=1, U=0  ;     P=0, U=1
      FA  full stack,  ascending    ;     P=0, U=0  ;     P=1, U=1

Ie. the following expressions are aliases for each other:

      STMFD=STMDB=PUSH   STMED=STMDA   STMFA=STMIB   STMEA=STMIA
      LDMFD=LDMIA=POP    LDMED=LDMIB   LDMFA=LDMDA   LDMEA=LDMDB

Note: The equivalent THUMB functions use fixed organization:

      PUSH/POP: full descending     ;base register SP (R13)
      LDM/STM:  increment after     ;base register R0..R7

Descending is common stack organization as used in 80x86 and Z80 CPUs, SP is decremented when pushing/storing data, and incremented when popping/loading data.
When S Bit is set (S=1)
If instruction is LDM and R15 is in the list: (Mode Changes)

      While R15 loaded, additionally: CPSR=SPSR_<current mode>

Otherwise: (User bank transfer)

      Rlist is referring to User Bank Registers, R0-R15 (rather than
      register related to the current mode, such like R14_svc etc.)
      Base write-back should not be used for User bank transfer.
      Caution - When instruction is LDM:
      If the following instruction reads from a banked register (eg. R14_svc),
      then CPU might still read R14 instead; if necessary insert a dummy NOP.

Notes
The base address should be usually word-aligned.
LDM Rn,...,PC on ARMv4 leaves CPSR.T unchanged.
LDR Rn,...,PC on ARMv5 sets CPSR.T to <op> Bit0, (1=Switch to Thumb).
Transfer Order
The lowest Register in Rlist (R0 if its in the list) will be loaded/stored to/from the lowest memory address.
Internally, the rlist register are always processed with INCREASING addresses (ie. for DECREASING addressing modes, the CPU does first calculate the lowest address, and does then process rlist with increasing addresses; this detail can be important when accessing memory mapped I/O ports).
Strange Effects on Invalid Rlist's
Empty Rlist: R15 loaded/stored (ARMv4 only), and Rb=Rb+/-40h (ARMv4-v5).
Writeback with Rb included in Rlist: Store OLD base if Rb is FIRST entry in Rlist, otherwise store NEW base (STM/ARMv4), always store OLD base (STM/ARMv5), no writeback (LDM/ARMv4), writeback if Rb is "the ONLY register, or NOT the LAST register" in Rlist (LDM/ARMv5).

ARM Opcodes: Memory: Single Data Swap (SWP)

Opcode Format

      Bit    Expl.
      31-28  Condition
      27-23  Must be 00010b for this instruction
             Opcode (fixed)
               SWP{cond}{B} Rd,Rm,[Rn]      ;Rd=[Rn], [Rn]=Rm
      22     B - Byte/Word bit (0=swap 32bit/word, 1=swap 8bit/byte)
      21-20  Must be 00b for this instruction
      19-16  Rn - Base register                     (R0-R14)
      15-12  Rd - Destination Register              (R0-R14)
      11-4   Must be 00001001b for this instruction
      3-0    Rm - Source Register                   (R0-R14)

SWP/SWPB supported by ARMv2a and up. SWP/SWPB has been deprecated in ARMv6, made optional in ARMv7 (with the possibility of disabling it if still available), and removed in ARMv8.
Swap works properly including if Rm and Rn specify the same register.
R15 may not be used for either Rn,Rd,Rm. (Rn=R15 would be MRS opcode).
Upper bits of Rd are zero-expanded when using Byte quantity. For info about byte and word data memory addressing, read LDR and STR opcode description.
Execution Time: 1S+2N+1I. That is, 2N data cycles, 1S code cycle, plus 1I.

ARM Opcodes: Coprocessor Instructions (MRC/MCR, LDC/STC, CDP, MCRR/MRRC)

Coprocessor Register Transfers (MRC, MCR) (with ARM Register read/write)

      Bit    Expl.
      31-28  Condition (or 1111b for MRC2/MCR2 opcodes on ARMv5 and up)
      27-24  Must be 1110b for this instruction
      23-21  CP Opc - Coprocessor operation code         (0-7)
      20     ARM-Opcode (0-1)
              0: MCR{cond} Pn,<cpopc>,Rd,Cn,Cm{,<cp>}   ;move from ARM to CoPro
              0: MCR2      Pn,<cpopc>,Rd,Cn,Cm{,<cp>}   ;move from ARM to CoPro
              1: MRC{cond} Pn,<cpopc>,Rd,Cn,Cm{,<cp>}   ;move from CoPro to ARM
              1: MRC2      Pn,<cpopc>,Rd,Cn,Cm{,<cp>}   ;move from CoPro to ARM
      19-16  Cn     - Coprocessor source/dest. Register  (C0-C15)
      15-12  Rd     - ARM source/destination Register    (R0-R15)
      11-8   Pn     - Coprocessor number                 (P0-P15)
      7-5    CP     - Coprocessor information            (0-7)
      4      Reserved, must be one (1) (otherwise CDP opcode)
      3-0    Cm     - Coprocessor operand Register       (C0-C15)

MCR/MRC supported by ARMv2 and up, MCR2/MRC2 by ARMv5 and up.
A22i syntax allows to use MOV with Rd specified as first (dest), or last (source) operand. Native MCR/MRC syntax uses Rd as middle operand, <cp> can be ommited if <cp> is zero.
When using MCR with R15: Coprocessor will receive a data value of PC+12.
When using MRC with R15: Bit 31-28 of data are copied to Bit 31-28 of CPSR (ie. N,Z,C,V flags), other data bits are ignored, CPSR Bit 27-0 are not affected, R15 (PC) is not affected.
Execution time: 1S+bI+1C for MCR, 1S+(b+1)I+1C for MRC.
Return: For MRC only: Either R0-R14 modified, or flags affected (see above).
For details refer to original ARM docs. The opcodes are irrelevant for GBA/NDS7 because no coprocessor exists (except for a dummy CP14 unit). However, NDS9 includes a working CP15 unit. And, 3DS ARM11 uses CP10/CP11 as VFP floating point unit.
ARM CP14 ICEbreaker Debug Communications Channel
ARM CP15 System Control Coprocessor
ARM Vector Floating-point Unit (VFP)
Coprocessor Data Transfers (LDC, STC) (with Memory read/write)

      Bit    Expl.
      31-28  Condition (or 1111b for LDC2/STC2 opcodes on ARMv5 and up)
      27-25  Must be 110b for this instruction
      24     P - Pre/Post (0=post; add offset after transfer, 1=pre; before trans.)
      23     U - Up/Down Bit (0=down; subtract offset from base, 1=up; add to base)
      22     N - Transfer length (0-1, interpretation depends on co-processor)
      21     W - Write-back bit (0=no write-back, 1=write address into base)
      20     Opcode (0-1)
              0: STC{cond}{L} Pn,Cd,<Address>  ;Store to memory (from coprocessor)
              0: STC2{L}      Pn,Cd,<Address>  ;Store to memory (from coprocessor)
              1: LDC{cond}{L} Pn,Cd,<Address>  ;Read from memory (to coprocessor)
              1: LDC2{L}      Pn,Cd,<Address>  ;Read from memory (to coprocessor)
              whereas {L} indicates long transfer (Bit 22: N=1)
      19-16  Rn     - ARM Base Register              (R0-R15)     (R15=PC+8)
      15-12  Cd     - Coprocessor src/dest Register  (C0-C15)
      11-8   Pn     - Coprocessor number             (P0-P15)
      7-0    Offset - Unsigned Immediate, step 4     (0-1020, in steps of 4)

LDC/STC supported by ARMv2 and up, LDC2/STC2 by ARMv5 and up.
Execution time: (n-1)S+2N+bI, n=number of words transferred.
For details refer to original ARM docs, irrelevant in GBA because no coprocessor exists.
Coprocessor Data Operations (CDP) (without Memory or ARM Register operand)

      Bit    Expl.
      31-28  Condition (or 1111b for CDP2 opcode on ARMv5 and up)
      27-24  Must be 1110b for this instruction
             ARM-Opcode (fixed)
               CDP{cond} Pn,<cpopc>,Cd,Cn,Cm{,<cp>}
               CDP2      Pn,<cpopc>,Cd,Cn,Cm{,<cp>}
      23-20  CP Opc - Coprocessor operation code       (0-15)
      19-16  Cn     - Coprocessor operand Register     (C0-C15)
      15-12  Cd     - Coprocessor destination Register (C0-C15)
      11-8   Pn     - Coprocessor number               (P0-P15)
      7-5    CP     - Coprocessor information          (0-7)
      4      Reserved, must be zero (otherwise MCR/MRC opcode)
      3-0    Cm     - Coprocessor operand Register     (C0-C15)

CDP supported by ARMv2 and up, CDP2 by ARMv5 and up.
Execution time: 1S+bI, b=number of cycles in coprocessor busy-wait loop.
Return: No flags affected, no ARM-registers used/modified.
For details refer to original ARM docs, irrelevant in GBA because no coprocessor exists.
Coprocessor Double-Register Transfer (MCRR, MRRC) - ARMv5TE and up only

      Bit    Expl.
      31-28  Condition
      27-21  Must be 1100010b for this instruction
      20     L - Opcode (Load/Store)
              0: MCRR{cond} Pn,opcode,Rd,Rn,Cm  ;write Rd,Rn to coproc
              0: MCRR2      Pn,opcode,Rd,Rn,Cm  ;write Rd,Rn to coproc
              1: MRRC{cond} Pn,opcode,Rd,Rn,Cm  ;read Rd,Rn from coproc
              1: MRRC2      Pn,opcode,Rd,Rn,Cm  ;read Rd,Rn from coproc
      19-16  Rn - Second source/dest register      (R0-R14)
      15-12  Rd - First source/dest register       (R0-R14)
      11-8   Pn     - Coprocessor number           (P0-P15)
      7-4    CP Opc - Coprocessor operation code   (0-15)
      3-0    Cm     - Coprocessor operand Register (C0-C15)

MCRR/MRRC are supported by ARMv5TE and up (not ARMv5, not ARMv5TExP).
MCRR2/MRRC2 are supported by ARMv6 and up.

THUMB Instruction Summary

The table below lists all THUMB mode instructions with clock cycles, affected CPSR flags, Format/chapter number, and description.
Only register R0..R7 can be used in thumb mode (unless R8-15,SP,PC are explicitly mentioned).
Logical Operations

      Instruction        Cycles Flags Format Expl.
      MOV Rd,Imm8bit      1S     NZ--  3   Rd=nn
      MOV Rd,Rs           1S     NZ00  2   Rd=Rs+0
      MOV R0..14,R8..15   1S     ----  5   Rd=Rs
      MOV R8..14,R0..15   1S     ----  5   Rd=Rs
      MOV R15,R0..15      2S+1N  ----  5   PC=Rs
      MVN Rd,Rs           1S     NZ--  4   Rd=NOT Rs
      AND Rd,Rs           1S     NZ--  4   Rd=Rd AND Rs
      TST Rd,Rs           1S     NZ--  4 Void=Rd AND Rs
      BIC Rd,Rs           1S     NZ--  4   Rd=Rd AND NOT Rs
      ORR Rd,Rs           1S     NZ--  4   Rd=Rd OR Rs
      EOR Rd,Rs           1S     NZ--  4   Rd=Rd XOR Rs
      LSL Rd,Rs,Imm5bit   1S     NZc-  1   Rd=Rs SHL nn
      LSL Rd,Rs           1S+1I  NZc-  4   Rd=Rd SHL (Rs AND 0FFh)
      LSR Rd,Rs,Imm5bit   1S     NZc-  1   Rd=Rs SHR nn
      LSR Rd,Rs           1S+1I  NZc-  4   Rd=Rd SHR (Rs AND 0FFh)
      ASR Rd,Rs,Imm5bit   1S     NZc-  1   Rd=Rs SAR nn
      ASR Rd,Rs           1S+1I  NZc-  4   Rd=Rd SAR (Rs AND 0FFh)
      ROR Rd,Rs           1S+1I  NZc-  4   Rd=Rd ROR (Rs AND 0FFh)
      NOP                 1S     ----  5   R8=R8

Carry flag affected only if shift amount is non-zero.
Arithmetic Operations and Multiply

      Instruction        Cycles Flags Format Expl.
      ADD Rd,Rs,Imm3bit   1S     NZCV  2   Rd=Rs+nn
      ADD Rd,Imm8bit      1S     NZCV  3   Rd=Rd+nn
      ADD Rd,Rs,Rn        1S     NZCV  2   Rd=Rs+Rn
      ADD R0..14,R8..15   1S     ----  5   Rd=Rd+Rs
      ADD R8..14,R0..15   1S     ----  5   Rd=Rd+Rs
      ADD R15,R0..15      2S+1N  ----  5   PC=Rd+Rs
      ADD Rd,PC,Imm8bit*4 1S     ---- 12   Rd=(($+4) AND NOT 2)+nn
      ADD Rd,SP,Imm8bit*4 1S     ---- 12   Rd=SP+nn
      ADD SP,Imm7bit*4    1S     ---- 13   SP=SP+nn
      ADD SP,-Imm7bit*4   1S     ---- 13   SP=SP-nn
      ADC Rd,Rs           1S     NZCV  4   Rd=Rd+Rs+Cy
      SUB Rd,Rs,Imm3Bit   1S     NZCV  2   Rd=Rs-nn
      SUB Rd,Imm8bit      1S     NZCV  3   Rd=Rd-nn
      SUB Rd,Rs,Rn        1S     NZCV  2   Rd=Rs-Rn
      SBC Rd,Rs           1S     NZCV  4   Rd=Rd-Rs-NOT Cy
      NEG Rd,Rs           1S     NZCV  4   Rd=0-Rs
      CMP Rd,Imm8bit      1S     NZCV  3 Void=Rd-nn
      CMP Rd,Rs           1S     NZCV  4 Void=Rd-Rs
      CMP R0-15,R8-15     1S     NZCV  5 Void=Rd-Rs
      CMP R8-15,R0-15     1S     NZCV  5 Void=Rd-Rs
      CMN Rd,Rs           1S     NZCV  4 Void=Rd+Rs
      MUL Rd,Rs           1S+mI  NZx-  4   Rd=Rd*Rs

Jumps and Calls

      Instruction        Cycles    Flags Format Expl.
      B disp              2S+1N     ---- 18  PC=$+/-2048
      BL disp             3S+1N     ---- 19  PC=$+/-4M, LR=$+5
      B{cond=true} disp   2S+1N     ---- 16  PC=$+/-0..256
      B{cond=false} disp  1S        ---- 16  N/A
      BX R0..15           2S+1N     ----  5  PC=Rs, ARM/THUMB (Rs bit0)
      SWI Imm8bit         2S+1N     ---- 17  PC=8, ARM SVC mode, LR=$+2
      BKPT Imm8bit        ???       ---- 17  ??? ARM9 Prefetch Abort
      BLX disp            ???       ---- ??? ??? ARM9
      BLX R0..R14         ???       ---- ??? ??? ARM9
      POP {Rlist,}PC   (n+1)S+2N+1I ---- 14
      MOV R15,R0..15      2S+1N     ----  5  PC=Rs
      ADD R15,R0..15      2S+1N     ----  5  PC=Rd+Rs

The thumb BL instruction occupies two 16bit opcodes, 32bit in total.
Memory Load/Store

      Instruction        Cycles    Flags Format Expl.
      LDR  Rd,[Rb,5bit*4] 1S+1N+1I  ----  9  Rd = WORD[Rb+nn]
      LDR  Rd,[PC,8bit*4] 1S+1N+1I  ----  6  Rd = WORD[PC+nn]
      LDR  Rd,[SP,8bit*4] 1S+1N+1I  ---- 11  Rd = WORD[SP+nn]
      LDR  Rd,[Rb,Ro]     1S+1N+1I  ----  7  Rd = WORD[Rb+Ro]
      LDRB Rd,[Rb,5bit*1] 1S+1N+1I  ----  9  Rd = BYTE[Rb+nn]
      LDRB Rd,[Rb,Ro]     1S+1N+1I  ----  7  Rd = BYTE[Rb+Ro]
      LDRH Rd,[Rb,5bit*2] 1S+1N+1I  ---- 10  Rd = HALFWORD[Rb+nn]
      LDRH Rd,[Rb,Ro]     1S+1N+1I  ----  8  Rd = HALFWORD[Rb+Ro]
      LDSB Rd,[Rb,Ro]     1S+1N+1I  ----  8  Rd = SIGNED_BYTE[Rb+Ro]
      LDSH Rd,[Rb,Ro]     1S+1N+1I  ----  8  Rd = SIGNED_HALFWORD[Rb+Ro]
      STR  Rd,[Rb,5bit*4] 2N        ----  9  WORD[Rb+nn] = Rd
      STR  Rd,[SP,8bit*4] 2N        ---- 11  WORD[SP+nn] = Rd
      STR  Rd,[Rb,Ro]     2N        ----  7  WORD[Rb+Ro] = Rd
      STRB Rd,[Rb,5bit*1] 2N        ----  9  BYTE[Rb+nn] = Rd
      STRB Rd,[Rb,Ro]     2N        ----  7  BYTE[Rb+Ro] = Rd
      STRH Rd,[Rb,5bit*2] 2N        ---- 10  HALFWORD[Rb+nn] = Rd
      STRH Rd,[Rb,Ro]     2N        ----  8  HALFWORD[Rb+Ro]=Rd
      PUSH {Rlist}{LR}    (n-1)S+2N ---- 14
      POP  {Rlist}{PC}              ---- 14  (ARM9: with mode switch)
      STMIA Rb!,{Rlist}   (n-1)S+2N ---- 15
      LDMIA Rb!,{Rlist}   nS+1N+1I  ---- 15

THUMB Binary Opcode Format
This table summarizes the position of opcode/parameter bits for THUMB mode instructions, Format 1-19.

     Form|_15|_14|_13|_12|_11|_10|_9_|_8_|_7_|_6_|_5_|_4_|_3_|_2_|_1_|_0_|
     __1_|_0___0___0_|__Op___|_______Offset______|____Rs_____|____Rd_____|Shifted
     __2_|_0___0___0___1___1_|_I,_Op_|___Rn/nn___|____Rs_____|____Rd_____|ADD/SUB
     __3_|_0___0___1_|__Op___|____Rd_____|_____________Offset____________|Immedi.
     __4_|_0___1___0___0___0___0_|______Op_______|____Rs_____|____Rd_____|AluOp
     __5_|_0___1___0___0___0___1_|__Op___|Hd_|Hs_|____Rs_____|____Rd_____|HiReg/BX
     __6_|_0___1___0___0___1_|____Rd_____|_____________Word______________|LDR PC
     __7_|_0___1___0___1_|__Op___|_0_|___Ro______|____Rb_____|____Rd_____|LDR/STR
     __8_|_0___1___0___1_|__Op___|_1_|___Ro______|____Rb_____|____Rd_____|""H/SB/SH
     __9_|_0___1___1_|__Op___|_______Offset______|____Rb_____|____Rd_____|""{B}
     _10_|_1___0___0___0_|Op_|_______Offset______|____Rb_____|____Rd_____|""H
     _11_|_1___0___0___1_|Op_|____Rd_____|_____________Word______________|"" SP
     _12_|_1___0___1___0_|Op_|____Rd_____|_____________Word______________|ADD PC/SP
     _13_|_1___0___1___1___0___0___0___0_|_S_|___________Word____________|ADD SP,nn
     _14_|_1___0___1___1_|Op_|_1___0_|_R_|____________Rlist______________|PUSH/POP
     _17_|_1___0___1___1___1___1___1___0_|___________User_Data___________|ARM9:BKPT
     _X__|_1___0___1___1___   ..............................             |ARM11...
      0110 011 Change Processor State        CPS on page B4-2
      0001 xxx Compare and Branch on Zero    CBNZ, CBZ on page A6-52
      1011 xxx Compare and Branch on Nonzero CBNZ, CBZ on page A6-52
      0011 xxx Compare and Branch on Zero    CBNZ, CBZ on page A6-52
      1001 xxx Compare and Branch on Nonzero CBNZ, CBZ on page A6-52
      0010 00x Signed Extend Halfword        SXTH on page A6-256
      0010 01x Signed Extend Byte            SXTB on page A6-254
      0010 10x Unsigned Extend Halfword      UXTH on page A6-274
      0010 11x Unsigned Extend Byte          UXTB on page A6-272
      1010 00x Byte-Reverse Word             REV on page A6-191
      1010 01x Byte-Reverse Packed Halfword  REV16 on page A6-192
      1010 11x Byte-Reverse Signed Halfword  REVSH on page A6-193
      1111 xxx If-Then, and hints If-Then, and hints on page A5-11
     _15_|_1___1___0___0_|Op_|____Rb_____|____________Rlist______________|STM/LDM
     _16_|_1___1___0___1_|_____Cond______|_________Signed_Offset_________|B{cond}
     _U__|_1___1___0___1___1___1___1___0_|_____________var_______________|UndefARM9
     _17_|_1___1___0___1___1___1___1___1_|___________User_Data___________|SWI
     _18_|_1___1___1___0___0_|________________Offset_____________________|B
     _19_|_1___1___1___0___1_|_________________________var___________|_0_|BLX.ARM9
     _U__|_1___1___1___0___1_|_________________________var___________|_1_|UndefARM9
     _19_|_1___1___1___1_|_H_|______________Offset_Low/High______________|BL,BLX

Further UNDEFS ??? ARM9?

     1011 0001 xxxxxxxx (reserved)
     1011 0x1x xxxxxxxx (reserved)
     1011 10xx xxxxxxxx (reserved)
     1011 1111 xxxxxxxx (reserved)
     1101 1110 xxxxxxxx (free for user)

THUMB Opcodes: Register Operations (ALU, BX)

THUMB.1: move shifted register

      15-13  Must be 000b for 'move shifted register' instructions
      12-11  Opcode
               00b: LSL{S} Rd,Rs,#Offset   (logical/arithmetic shift left)
               01b: LSR{S} Rd,Rs,#Offset   (logical    shift right)
               10b: ASR{S} Rd,Rs,#Offset   (arithmetic shift right)
               11b: Reserved (used for add/subtract instructions)
      10-6   Offset                     (0-31)
      5-3    Rs - Source register       (R0..R7)
      2-0    Rd - Destination register  (R0..R7)

Example: LSL Rd,Rs,#nn ; Rd = Rs << nn ; ARM equivalent: MOVS Rd,Rs,LSL #nn
Zero shift amount is having special meaning (same as for ARM shifts), LSL#0 performs no shift (the carry flag remains unchanged), LSR/ASR#0 are interpreted as LSR/ASR#32. Attempts to specify LSR/ASR#0 in source code are automatically redirected as LSL#0, and source LSR/ASR#32 is redirected as opcode LSR/ASR#0.
Execution Time: 1S
Flags: Z=zeroflag, N=sign, C=carry (except LSL#0: C=unchanged), V=unchanged.
THUMB.2: add/subtract

      15-11  Must be 00011b for 'add/subtract' instructions
      10-9   Opcode (0-3)
               0: ADD{S} Rd,Rs,Rn   ;add register        Rd=Rs+Rn
               1: SUB{S} Rd,Rs,Rn   ;subtract register   Rd=Rs-Rn
               2: ADD{S} Rd,Rs,#nn  ;add immediate       Rd=Rs+nn
               3: SUB{S} Rd,Rs,#nn  ;subtract immediate  Rd=Rs-nn
             Pseudo/alias opcode with Imm=0:
               2: MOV{ADDS} Rd,Rs      ;move (affects cpsr) Rd=Rs+0
      8-6    For Register Operand:
               Rn - Register Operand (R0..R7)
             For Immediate Operand:
               nn - Immediate Value  (0-7)
      5-3    Rs - Source register       (R0..R7)
      2-0    Rd - Destination register  (R0..R7)

Return: Rd contains result, N,Z,C,V affected (including MOV).
Execution Time: 1S
THUMB.3: move/compare/add/subtract immediate

      15-13  Must be 001b for this type of instructions
      12-11  Opcode
               00b: MOV{S} Rd,#nn      ;move     Rd   = #nn
               01b: CMP{S} Rd,#nn      ;compare  Void = Rd - #nn
               10b: ADD{S} Rd,#nn      ;add      Rd   = Rd + #nn
               11b: SUB{S} Rd,#nn      ;subtract Rd   = Rd - #nn
      10-8   Rd - Destination Register  (R0..R7)
      7-0    nn - Unsigned Immediate    (0-255)

ARM equivalents for MOV/CMP/ADD/SUB are MOVS/CMP/ADDS/SUBS same format.
Execution Time: 1S
Return: Rd contains result (except CMP), N,Z,C,V affected (for MOV only N,Z).
THUMB.4: ALU operations

      15-10  Must be 010000b for this type of instructions
      9-6    Opcode (0-Fh)
               0: AND{S} Rd,Rs     ;AND logical       Rd = Rd AND Rs
               1: EOR{S} Rd,Rs     ;XOR logical       Rd = Rd XOR Rs
               2: LSL{S} Rd,Rs     ;log. shift left   Rd = Rd << (Rs AND 0FFh)
               3: LSR{S} Rd,Rs     ;log. shift right  Rd = Rd >> (Rs AND 0FFh)
               4: ASR{S} Rd,Rs     ;arit shift right  Rd = Rd SAR (Rs AND 0FFh)
               5: ADC{S} Rd,Rs     ;add with carry    Rd = Rd + Rs + Cy
               6: SBC{S} Rd,Rs     ;sub with carry    Rd = Rd - Rs - NOT Cy
               7: ROR{S} Rd,Rs     ;rotate right      Rd = Rd ROR (Rs AND 0FFh)
               8: TST    Rd,Rs     ;test            Void = Rd AND Rs
               9: NEG{S} Rd,Rs     ;negate            Rd = 0 - Rs
               A: CMP    Rd,Rs     ;compare         Void = Rd - Rs
               B: CMN    Rd,Rs     ;neg.compare     Void = Rd + Rs
               C: ORR{S} Rd,Rs     ;OR logical        Rd = Rd OR Rs
               D: MUL{S} Rd,Rs     ;multiply          Rd = Rd * Rs
               E: BIC{S} Rd,Rs     ;bit clear         Rd = Rd AND NOT Rs
               F: MVN{S} Rd,Rs     ;not               Rd = NOT Rs
      5-3    Rs - Source Register       (R0..R7)
      2-0    Rd - Destination Register  (R0..R7)

ARM equivalent for NEG would be RSBS.
Return: Rd contains result (except TST,CMP,CMN),
Affected Flags:

      N,Z,C,V for  ADC,SBC,NEG,CMP,CMN
      N,Z,C   for  LSL,LSR,ASR,ROR (carry flag unchanged if zero shift amount)
      N,Z,C   for  MUL on ARMv4 and below: carry flag destroyed
      N,Z     for  MUL on ARMv5 and above: carry flag unchanged
      N,Z     for  AND,EOR,TST,ORR,BIC,MVN

Execution Time:

      1S      for  AND,EOR,ADC,SBC,TST,NEG,CMP,CMN,ORR,BIC,MVN
      1S+1I   for  LSL,LSR,ASR,ROR
      1S+mI   for  MUL on ARMv4 (m=1..4; depending on MSBs of incoming Rd value)
      1S+mI   for  MUL on ARMv5 (m=3; fucking slow, no matter of MSBs of Rd value)

THUMB.5: Hi register operations/branch exchange

      15-10  Must be 010001b for this type of instructions
      9-8    Opcode (0-3)
               0: ADD Rd,Rs   ;add        Rd = Rd+Rs
               1: CMP Rd,Rs   ;compare  Void = Rd-Rs  ;CPSR affected
               2: MOV Rd,Rs   ;move       Rd = Rs
               2: NOP         ;nop        R8 = R8
               3: BX  Rs      ;jump       PC = Rs     ;may switch THUMB/ARM
               3: BLX Rs      ;call       PC = Rs     ;may switch THUMB/ARM (ARM9)
      7      MSBd - Destination Register most significant bit (or BL/BLX flag)
      6      MSBs - Source Register most significant bit
      5-3    Rs - Source Register        (together with MSBs: R0..R15)
      2-0    Rd - Destination Register   (together with MSBd: R0..R15)

Restrictions: For ADD/CMP/MOV, MSBs and/or MSBd must be set, ie. it is not allowed that both are cleared.
When using R15 (PC) as operand, the value will be the address of the instruction plus 4 (ie. $+4). Except for BX R15: CPU switches to ARM state, and PC is auto-aligned as (($+4) AND NOT 2).
For BX, MSBs may be 0 or 1, MSBd must be zero, Rd is not used/zero.
For BLX, MSBs may be 0 or 1, MSBd must be set, Rd is not used/zero.
For BX/BLX, when Bit 0 of the value in Rs is zero:

      Processor will be switched into ARM mode!
      If so, Bit 1 of Rs must be cleared (32bit word aligned).
      Thus, BX PC (switch to ARM) may be issued from word-aligned address
      only, the destination is PC+4 (ie. the following halfword is skipped).

BLX may not use R15. BLX saves the return address as LR=PC+3 (with thumb bit).
Using BLX R14 is possible (sets PC=Old_LR, and New_LR=retadr).
Assemblers/Disassemblers should use MOV R8,R8 as NOP (in THUMB mode).
Return: Only CMP affects CPSR condition flags!
Execution Time:

     1S     for ADD/MOV/CMP
     2S+1N  for ADD/MOV with Rd=R15, and for BX

THUMB Opcodes: Memory Load/Store (LDR/STR)

THUMB.6: load PC-relative (for loading immediates from literal pool)

      15-11  Must be 01001b for this type of instructions
      N/A    Opcode (fixed)
               LDR Rd,[PC,#nn]      ;load 32bit    Rd = WORD[PC+nn]
      10-8   Rd - Destination Register   (R0..R7)
      7-0    nn - Unsigned offset        (0-1020 in steps of 4)

The value of PC will be interpreted as (($+4) AND NOT 2).
Return: No flags affected, data loaded into Rd.
Execution Time: 1S+1N+1I
THUMB.7: load/store with register offset

      15-12  Must be 0101b for this type of instructions
      11-10  Opcode (0-3)
              0: STR  Rd,[Rb,Ro]   ;store 32bit data  WORD[Rb+Ro] = Rd
              1: STRB Rd,[Rb,Ro]   ;store  8bit data  BYTE[Rb+Ro] = Rd
              2: LDR  Rd,[Rb,Ro]   ;load  32bit data  Rd = WORD[Rb+Ro]
              3: LDRB Rd,[Rb,Ro]   ;load   8bit data  Rd = BYTE[Rb+Ro]
      9      Must be zero (0) for this type of instructions
      8-6    Ro - Offset Register              (R0..R7)
      5-3    Rb - Base Register                (R0..R7)
      2-0    Rd - Source/Destination Register  (R0..R7)

Return: No flags affected, data loaded either into Rd or into memory.
Execution Time: 1S+1N+1I for LDR, or 2N for STR
THUMB.8: load/store sign-extended byte/halfword

      15-12  Must be 0101b for this type of instructions
      11-10  Opcode (0-3)
              0: STRH Rd,[Rb,Ro]  ;store 16bit data          HALFWORD[Rb+Ro] = Rd
              1: LDSB Rd,[Rb,Ro]  ;load sign-extended 8bit   Rd = BYTE[Rb+Ro]
              2: LDRH Rd,[Rb,Ro]  ;load zero-extended 16bit  Rd = HALFWORD[Rb+Ro]
              3: LDSH Rd,[Rb,Ro]  ;load sign-extended 16bit  Rd = HALFWORD[Rb+Ro]
      9      Must be set (1) for this type of instructions
      8-6    Ro - Offset Register              (R0..R7)
      5-3    Rb - Base Register                (R0..R7)
      2-0    Rd - Source/Destination Register  (R0..R7)

Return: No flags affected, data loaded either into Rd or into memory.
Execution Time: 1S+1N+1I for LDR, or 2N for STR
THUMB.9: load/store with immediate offset

      15-13  Must be 011b for this type of instructions
      12-11  Opcode (0-3)
              0: STR  Rd,[Rb,#nn]  ;store 32bit data   WORD[Rb+nn] = Rd
              1: LDR  Rd,[Rb,#nn]  ;load  32bit data   Rd = WORD[Rb+nn]
              2: STRB Rd,[Rb,#nn]  ;store  8bit data   BYTE[Rb+nn] = Rd
              3: LDRB Rd,[Rb,#nn]  ;load   8bit data   Rd = BYTE[Rb+nn]
      10-6   nn - Unsigned Offset              (0-31 for BYTE, 0-124 for WORD)
      5-3    Rb - Base Register                (R0..R7)
      2-0    Rd - Source/Destination Register  (R0..R7)

Return: No flags affected, data loaded either into Rd or into memory.
Execution Time: 1S+1N+1I for LDR, or 2N for STR
THUMB.10: load/store halfword

      15-12  Must be 1000b for this type of instructions
      11     Opcode (0-1)
              0: STRH Rd,[Rb,#nn]  ;store 16bit data   HALFWORD[Rb+nn] = Rd
              1: LDRH Rd,[Rb,#nn]  ;load  16bit data   Rd = HALFWORD[Rb+nn]
      10-6   nn - Unsigned Offset              (0-62, step 2)
      5-3    Rb - Base Register                (R0..R7)
      2-0    Rd - Source/Destination Register  (R0..R7)

Return: No flags affected, data loaded either into Rd or into memory.
Execution Time: 1S+1N+1I for LDR, or 2N for STR
THUMB.11: load/store SP-relative

      15-12  Must be 1001b for this type of instructions
      11     Opcode (0-1)
              0: STR  Rd,[SP,#nn]  ;store 32bit data   WORD[SP+nn] = Rd
              1: LDR  Rd,[SP,#nn]  ;load  32bit data   Rd = WORD[SP+nn]
      10-8   Rd - Source/Destination Register  (R0..R7)
      7-0    nn - Unsigned Offset              (0-1020, step 4)

Return: No flags affected, data loaded either into Rd or into memory.
Execution Time: 1S+1N+1I for LDR, or 2N for STR

THUMB Opcodes: Memory Addressing (ADD PC/SP)

THUMB.12: get relative address

      15-12  Must be 1010b for this type of instructions
      11     Opcode/Source Register (0-1)
              0: ADD  Rd,PC,#nn    ;Rd = (($+4) AND NOT 2) + nn
              1: ADD  Rd,SP,#nn    ;Rd = SP + nn
      10-8   Rd - Destination Register         (R0..R7)
      7-0    nn - Unsigned Offset              (0-1020, step 4)

Return: No flags affected, result in Rd.
Execution Time: 1S
THUMB.13: add offset to stack pointer

      15-8   Must be 10110000b for this type of instructions
      7      Opcode/Sign
              0: ADD  SP,#nn       ;SP = SP + nn
              1: ADD  SP,#-nn      ;SP = SP - nn
      6-0    nn - Unsigned Offset    (0-508, step 4)

Return: No flags affected, SP adjusted.
Execution Time: 1S

THUMB Opcodes: Memory Multiple Load/Store (PUSH/POP and LDM/STM)

THUMB.14: push/pop registers

      15-12  Must be 1011b for this type of instructions
      11     Opcode (0-1)
              0: PUSH {Rlist}{LR}   ;store in memory, decrements SP (R13)
              1: POP  {Rlist}{PC}   ;load from memory, increments SP (R13)
      10-9   Must be 10b for this type of instructions
      8      PC/LR Bit (0-1)
              0: No
              1: PUSH LR (R14), or POP PC (R15)
      7-0    Rlist - List of Registers (R7..R0)

In THUMB mode stack is always meant to be 'full descending', ie. PUSH is equivalent to 'STMFD/STMDB' and POP to 'LDMFD/LDMIA' in ARM mode.
Examples:

     PUSH {R0-R3}     ;push R0,R1,R2,R3
     PUSH {R0,R2,LR}  ;push R0,R2,LR
     POP  {R4,R7}     ;pop R4,R7
     POP  {R2-R4,PC}  ;pop R2,R3,R4,PC

Note: When calling to a sub-routine, the return address is stored in LR register, when calling further sub-routines, PUSH {LR} must be used to save higher return address on stack. If so, POP {PC} can be later used to return from the sub-routine.
POP {PC} ignores the least significant bit of the return address (processor remains in thumb state even if bit0 was cleared), when intending to return with optional mode switch, use a POP/BX combination (eg. POP {R3} / BX R3).
ARM9: POP {PC} copies the LSB to thumb bit (switches to ARM if bit0=0).
Return: No flags affected, SP adjusted, registers loaded/stored.
Execution Time: nS+1N+1I (POP), (n+1)S+2N+1I (POP PC), or (n-1)S+2N (PUSH).
THUMB.15: multiple load/store

      15-12  Must be 1100b for this type of instructions
      11     Opcode (0-1)
              0: STMIA Rb!,{Rlist}   ;store in memory, increments Rb
              1: LDMIA Rb!,{Rlist}   ;load from memory, increments Rb
      10-8   Rb - Base register (modified) (R0-R7)
      7-0    Rlist - List of Registers     (R7..R0)

Both STM and LDM are incrementing the Base Register.
The lowest register in the list (ie. R0, if it's in the list) is stored/loaded at the lowest memory address.
Examples:

     STMIA R7!,{R0-R2}  ;store R0,R1,R2
     LDMIA R0!,{R1,R5}  ;store R1,R5

Return: No flags affected, Rb adjusted, registers loaded/stored.
Execution Time: nS+1N+1I for LDM, or (n-1)S+2N for STM.
Strange Effects on Invalid Rlist's
Empty Rlist: R15 loaded/stored (ARMv4 only), and Rb=Rb+40h (ARMv4-v5).
Writeback with Rb included in Rlist: Store OLD base if Rb is FIRST entry in Rlist, otherwise store NEW base (STM/ARMv4), always store OLD base (STM/ARMv5), no writeback (LDM/ARMv4/ARMv5; at this point, THUMB opcodes work different than ARM opcodes).

THUMB Opcodes: Jumps and Calls

THUMB.16: conditional branch

      15-12  Must be 1101b for this type of instructions
      11-8   Opcode/Condition (0-Fh)
              0: BEQ label        ;Z=1         ;equal (zero) (same)
              1: BNE label        ;Z=0         ;not equal (nonzero) (not same)
              2: BCS/BHS label    ;C=1         ;unsigned higher or same (carry set)
              3: BCC/BLO label    ;C=0         ;unsigned lower (carry cleared)
              4: BMI label        ;N=1         ;signed  negative (minus)
              5: BPL label        ;N=0         ;signed  positive or zero (plus)
              6: BVS label        ;V=1         ;signed  overflow (V set)
              7: BVC label        ;V=0         ;signed  no overflow (V cleared)
              8: BHI label        ;C=1 and Z=0 ;unsigned higher
              9: BLS label        ;C=0 or Z=1  ;unsigned lower or same
              A: BGE label        ;N=V         ;signed greater or equal
              B: BLT label        ;N<>V        ;signed less than
              C: BGT label        ;Z=0 and N=V ;signed greater than
              D: BLE label        ;Z=1 or N<>V ;signed less or equal
              E: Undefined, should not be used
              F: Reserved for SWI instruction (see SWI opcode)
      7-0    Signed Offset, step 2 ($+4-256..$+4+254)

Destination address must by halfword aligned (ie. bit 0 cleared)
Return: No flags affected, PC adjusted if condition true
Execution Time:

      2S+1N   if condition true (jump executed)
      1S      if condition false

BX and ADD/MOV PC
See also THUMB.5: BX Rs, and ADD/MOV PC,Rs.
THUMB.18: unconditional branch

      15-11  Must be 11100b for this type of instructions
      N/A    Opcode (fixed)
              B label   ;branch (jump)
      10-0   Signed Offset, step 2 ($+4-2048..$+4+2046)

Return: No flags affected, PC adjusted.
Execution Time: 2S+1N
THUMB.19: long branch with link
This may be used to call (or jump) to a subroutine, return address is saved in LR (R14).
Unlike all other THUMB mode instructions, this instruction occupies 32bit of memory which are split into two 16bit THUMB opcodes.

     First Instruction - LR = PC+4+(nn SHL 12)
      15-11  Must be 11110b for BL/BLX type of instructions
      10-0   nn - Upper 11 bits of Target Address
     Second Instruction - PC = LR + (nn SHL 1), and LR = PC+2 OR 1 (and BLX: T=0)
      15-11  Opcode
              11111b: BL label   ;branch long with link
              11101b: BLX label  ;branch long with link switch to ARM mode (ARM9)
      10-0   nn - Lower 11 bits of Target Address (BLX: Bit0 Must be zero)

The destination address range is (PC+4)-400000h..+3FFFFEh, ie. PC+/-4M.
Target must be halfword-aligned. As Bit 0 in LR is set, it may be used to return by a BX LR instruction (keeping CPU in THUMB mode).
Return: No flags affected, PC adjusted, return address in LR.
Execution Time: 3S+1N (first opcode 1S, second opcode 2S+1N).
Note: Exceptions may or may not occur between first and second opcode, this is "implementation defined" (unknown how this is implemented in GBA and NDS).
Using only the 2nd half of BL as "BL LR+imm" is possible (for example, Mario Golf Advance Tour for GBA uses opcode F800h as "BL LR+0").
THUMB.17: software interrupt and breakpoint
SWI supposed for calls to the operating system - Enter Supervisor mode (SVC) in ARM state. BKPT intended for debugging - enters Abort mode in ARM state via Prefetch Abort vector.

      15-8   Opcode
              11011111b: SWI nn   ;software interrupt
              10111110b: BKPT nn  ;software breakpoint (ARMv5 and up)
      7-0    nn - Comment Field, ignored by processor (8bit value) (0-255)

Execution Time: 2S+1N
The exception handler may interprete the SWI Comment Field by examining the lower 8bit of the 16bit opcode opcode at [R14_svc-2].
If your are also using SWI's from inside of ARM mode, then the SWI handler must examine the T Bit SPSR_svc in order to determine whether it's been a ARM SWI - and if so, examine the lower 24bit of the 32bit opcode opcode at [R14_svc-4].
For Returning from SWI use "MOVS PC,R14", that instruction does restore both PC and CPSR, ie. PC=R14_svc, and CPSR=SPSR_svc, and (as called from THUMB mode), it'll also restore THUMB mode.
Nesting SWIs: SPSR_svc and R14_svc should be saved on stack before either invoking nested SWIs, or (if the IRQ handler uses SWIs) before enabling IRQs.
Execution SWI/BKPT:

      R14_svc=PC+2     R14_abt=PC+4   ;save return address
      SPSR_svc=CPSR    SPSR_abt=CPSR  ;save CPSR flags
      CPSR=<changed>   CPSR=<changed> ;Enter svc/abt, ARM state, IRQs disabled
      PC=VVVV0008h     PC=VVVV000Ch   ;jump to SWI/PrefetchAbort vector address

THUMB Opcodes: New THUMB Opcodes in ARM11

THUMB.X: signed/unsigned extend byte/halfword (ARMv6)
These unneccessary opcodes are apparently meant to reduce typical compiler overload (eg. for ensuring that "for i=0 to 7" won't end up with i>255).

      15-8   Must be 1011.0010b for this type of instructions
      7-6    Opcode
              00b  SXTH  Rd,Rm      ;sign-extend halfword
              01b  SXTB  Rd,Rm      ;sign-extend byte
              10b  UXTH  Rd,Rm      ;zero-extend halfword
              11b  UXTB  Rd,Rm      ;zero-extend byte
      5-3    Rm Source Register                    (R0-R7)
      2-0    Rd Destination Register               (R0-R7)

Return: No flags affected (though unspecified?).
Execution Time: ?
THUMB.X: byte-reverse word/halfword(s) (ARMv6)

      15-8   Must be 1011.1010b for this type of instructions
      7-6    Opcode
              00b  REV   Rd,Rm      ;swap byte3/byte0 and byte2/byte1  ;word
              01b  REV16 Rd,Rm      ;swap byte3/byte2 and byte1/byte0  ;packed half
              11b  REVSH Rd,Rm      ;swap byte1/byte0 and sign-extend  ;signed half
      5-3    Rm Source Register                    (R0-R7)
      2-0    Rd Destination Register               (R0-R7)

Return: No flags affected (though unspecified?).
Execution Time: ?
SETEND (ARMv6)

      15-4   Must be 101101100101b
      3      Opcode:
               0: SETEND LE   ;clear CPSR.E bit (little endian data access)
               1: SETEND BE   ;set CPSR.E bit (big endian data access)
      2-0    Should be 000b

THUMB.X: change processor state (ARMv6)

      15-5   Must be 10110110011b
      4      Opcode:
               0: CPSIE {A}{I}{F}   ;Interrupt Enable
               1: CPSID {A}{I}{F}   ;Interrupt Disable
      3      Must be 0b
      2      A  Affect CPSR.A (?)    (0=No, 1=Yes)
      1      I  Affect CPSR.I (IRQ)  (0=No, 1=Yes)
      0      F  Affect CPSR.F (FIQ)  (0=No, 1=Yes)

CPY

      15-8   Must be 01000110b for CPY Rd,Rm
      7      MSB of Rd
      6      MSB of Rm
      5-3    Rm Source Register
      2-0    Rd Destination Register

Move without changing flags. It's called CPY because THUMB syntax didn't distinguish between MOV and MOVS (until UAL syntax was invented, which makes the name CPY irrelevant).
CPY is officially supported in "T variants of ARMv6 and above" (in practice, it should work on ARMv4T and up, but wasn't officially documented until ARMv6).

ARM Pseudo Instructions and Directives

ARM Pseudo Instructions

      nop              mov r0,r0
      ldr Rd,=Imm      ldr Rd,[r15,disp] ;use .pool as parameter field
      add Rd,=addr     add/sub Rd,r15,disp
      adr Rd,addr      add/sub Rd,r15,disp
      adrl Rd,addr     two add/sub opcodes with disp=xx00h+00yyh
      mov Rd,Imm       mvn Rd,NOT Imm    ;or vice-versa
      and Rd,Rn,Imm    bic Rd,Rn,NOT Imm ;or vice-versa
      cmp Rd,Rn,Imm    cmn Rd,Rn,-Imm    ;or vice-versa
      add Rd,Rn,Imm    sub Rd,Rn,-Imm    ;or vice-versa

All above opcodes may be made conditional by specifying a {cond} field.
THUMB Pseudo Instructions

      nop              mov r8,r8
      ldr Rd,=Imm      ldr Rd,[r15,disp] ;use .pool as parameter field
      add Rd,=addr     add Rd,r15,disp
      adr Rd,addr      add Rd,r15,disp
      mov Rd,Rs        add Rd,Rs,0       ;with Rd,Rs in range r0-r7 each

A22i Directives

      org  adr     assume following code from this address on
      .gba         indicate GBA program
      .nds         indicate NDS program
      .dsi         indicate DSi program
      .firm3ds     indicate 3DS program (.firm format)
      .fix         fix GBA/NDS/DSi header checksum
      .ereader_create_bmp      create GBA e-Reader dotcode .BMP file(s) (bitmaps)
      .ereader_create_raw      create GBA e-Reader dotcode .RAW file (useless)
      .ereader_create_bin      create GBA e-Reader dotcode .BIN file (smallest)
      .ereader_japan_plus      japanese/plus     (default is non-japanese)
      .ereader_japan_original  japanese/original (with Z80-stub for GBA-code)
      .title 'Txt' defines a title (used for e-Reader dotcodes)
      .teak        select TeakLiteII instruction set (for DSi DSP)
      .xtensa      select Xtensa instruction set (for DSi Atheros Wifi)
      .rl78        select RL78 instruction set (for 3DS MCU)
      .norewrite   do not delete existing output file (keep following data in file)
      .data?       following defines RAM data structure (assembled to nowhere)
      .code        following is normal ROM code/data (assembled to ROM image)
      .include     includes specified source code file (no nesting/error handling)
      .import      imports specified binary file (optional parameters: ,begin,len)
      .radix nn    changes default numeric format (nn=2,8,10,16 = bin/oct/dec/hex)
      .errif expr  generates an error message if expression is nonzero
      .if expr     assembles following code only if expression is nonzero
      .else        invert previous .if condition
      .endif       terminate .if/.ifdef/.ifndef
      .ifdef sym   assemble following only if symbol is defined
      .ifndef sym  assemble following only if symbol is not defined
      .align nn    aligns to an address divisible-by-nn, inserts 00's
      .msg         defines a no$gba debugmessage string, such like .msg 'Init Okay'
      .brk         defines a no$gba source code break opcode
      l equ n      l=n
      l:   [cmd]   l=$   (global label)
      @@l: [cmd]   @@l=$ (local label, all locals are reset at next global label)
      end          end of source code
      db ...       define 8bit data (bytes)
      dw ...       define 16bit data (halfwords)
      dd ...       define 32bit data (words)
      defs nn      define nn bytes space (zero-filled)
      ;...         defines a comment (ignored by the assembler)
      //           alias for CRLF, eg. allows <db 'Text',0 // dw addr> in one line

A22i Alias Directives (for compatibility with other assemblers)

      align        .align 4          code16    .thumb
      align nn     .align nn         .code 16  .thumb
      % nn         defs nn           code32    .arm
      .space nn    defs nn           .code 32  .arm
      ..ds nn      defs nn           ltorg     .pool
      x=n          x equ n           .ltorg    .pool
      .equ x,n     x equ n           ..ltorg   .pool
      .define x n  x equ n           dcb       db (8bit data)
      incbin       .import           defb      db (8bit data)
      @@@...       ;comment          .byte     db (8bit data)
      @ ...        ;comment          .ascii    db (8bit string)
      @*...        ;comment          dcw       dw (16bit data)
      @...         ;comment          defw      dw (16bit data)
      .text        .code             .hword    dw (16bit data)
      .bss         .data?            dcd       dd (32bit data)
      .global      (ignored)         defd      dd (32bit data)
      .extern      (ignored)         .long     dd (32bit data)
      .thumb_func  (ignored)         .word     dw/dd, don't use
      #directive   .directive        .end      end
      .fill nn,1,0 defs nn

Alias Conditions, Opcodes, Operands

      hs   cs   ;condition higher or same = carry set
      lo   cc   ;condition lower = carry cleared
      asl  lsl  ;arithmetic shift left = logical shift left

A22i Numeric Formats & Dialects

      Type          Normal       Alias
      Decimal       85           #85  &d85
      Hexadecimal   55h          #55h  0x55  #0x55  $55  &h55
      Octal         125o         0o125  &o125
      Ascii         'U'          "U"
      Binary        01010101b    %01010101  0b01010101  &b01010101
      Roman         &rLXXXV      (very useful for arrays of kings and chapters)

Note: The default numeric format can be changed by the .radix directive (usually 10=decimal). For example, with radix 16, values like "85" and "0101b" are treated as hexadecimal numbers (in that case, decimal and binary numbers can be still defined with prefixes &d and &b).
A22i Numeric Operators Priority

      Prio  Operator           Aliases
      8     (,) brackets
      7     +,- sign
      6     *,/,MOD,SHL,SHR    MUL,DIV,<<,>>
      5     +,- operation
      4     EQ,GE,GT,LE,LT,NE  =,>=,>,<=,<,<>,==,!=
      3     NOT
      2     AND
      1     OR,XOR             EOR

Operators of same priority are processed from left to right.
Boolean operators (priority 4) return 1=TRUE, 0=FALSE.
A22i Nocash Syntax
Even though A22i does recognize the official ARM syntax, it's also allowing to use friendly code:

      mov   r0,0ffh         ;no C64-style "#", and no C-style "0x" required
      stmia [r7]!,r0,r4-r5  ;square [base] brackets, no fancy {rlist} brackets
      mov   r0,cpsr         ;no confusing MSR and MRS (whatever which is which)
      mov   r0,p0,0,c0,c0,0 ;no confusing MCR and MRC (whatever which is which)
      ldr   r0,[score]      ;allows to use clean brackets for relative addresses
      push  rlist           ;alias for stmfd [r13]!,rlist (and same for pop/ldmfd)
      label:                ;label definitions recommended to use ":" colons

[A22i is the no$gba debug version's built-in source code assembler.]

ARM CP14 ICEbreaker Debug Communications Channel

The ICEbreaker aka EmbeddedICE module may be found in ARM7TDMI and possibly also in other ARM processors. The main functionality of the module relies on external inputs (BREAKPT signal, etc.) being controlled by external debugging hardware. At software side, ICEbreaker contains a Debug Communications Channel (again to access external hardware), which can be accessed as coprocessor 14 via following opcodes:

      MRC{cond} P14,0,Rd,C0,C0,0  ;Read Debug Comms Control Register
      MRC{cond} P14,0,Rd,C1,C0,0  ;Read Debug Comms Data Register
      MRC{cond} P14,0,Rd,C2,C0,0  ;Read Debug Comms Status Register
      MCR{cond} P14,0,Rd,C1,C0,0  ;Write Debug Comms Data Register
      MCR{cond} P14,0,Rd,C2,C0,0  ;Write Debug Comms Status Register

The Control register consists of Bit31-28=ICEbreaker version (0001b for ARM7TDMI), Bit27-2=Not specified, Bit0/Bit1=Data Read/Write Status Flags.
The NDS7 and GBA allow to access CP14 (unlike as for CP0..CP13 & CP15, access to CP14 doesn't generate any exceptions), however, the ICEbreaker module appears to be disabled (or completely unimplemented), any reads from P14,0,Rd,C0,C0,0 through P14,7,Rd,C15,C15,7 are simply returning the prefetched opcode value from [$+8]. ICEbreaker might be eventually used and enabled in Nintendo's hardware debuggers, although external breakpoints are reportedly implemented via /FIQ input rather than via ICEbreaker hardware.
The NDS9 doesn't include a CP14 unit (or it is fully disabled), any attempts to access it are causing invalid instruction exceptions.

ARM CP15 System Control Coprocessor

ARM CP15 Overview
ARM CP15 ID Codes
ARM CP15 Control Register
ARM CP15 Memory Managment Unit (MMU)
ARM CP15 Protection Unit (PU)
ARM CP15 Cache Control
ARM CP15 Tightly Coupled Memory (TCM)
ARM CP15 Misc

ARM CP15 Overview

CP15
In many ARM CPUs, particulary such with memory control facilities, coprocessor number 15 (CP15) is used as built-in System Control Coprocessor.
CPUs without memory control functions typically don't include a CP15 at all, in that case even an attempt to read the Main ID register will cause an Undefined Instruction exception.
CP15 Opcodes
CP15 can be accessed via MCR and MRC opcodes, with Pn=P15, and <cpopc>=0.

      MCR{cond} P15,<cpopc>,Rd,Cn,Cm,<cp>   ;move from ARM to CP15
      MRC{cond} P15,<cpopc>,Rd,Cn,Cm,<cp>   ;move from CP15 to ARM

Rd can be any ARM register in range R0-R14, R15 should not be used with P15.
<cpopc>,Cn,Cm,<cp> are used to select a CP15 register, eg. 0,C0,C0,0 = Main ID Register.
Other coprocessor opcodes (CDP, LDC, STC) cannot be used with P15.
CP15 Register List

      Register       Expl.
      0,C0,C0,0      Main ID Register (R)
      0,C0,C0,1      Cache Type and Size (R)
      0,C0,C0,2      TCM Physical Size (R)
      0,C0,C0,3      ARM11: TLB Type Register
      0,C0,C1,0      ARM11: Processor Feature Register 0
      0,C0,C1,1      ARM11: Processor Feature Register 1
      0,C0,C1,2      ARM11: Debug Feature Register 0
      0,C0,C1,3      ARM11: Auxiliary Feature Register 0
      0,C0,C1,4      ARM11: Memory Model Feature Register 0
      0,C0,C1,5      ARM11: Memory Model Feature Register 1
      0,C0,C1,6      ARM11: Memory Model Feature Register 2
      0,C0,C1,7      ARM11: Memory Model Feature Register 3
      0,C0,C2,0      ARM11: Set Attributes Register 0
      0,C0,C2,1      ARM11: Set Attributes Register 1
      0,C0,C2,2      ARM11: Set Attributes Register 2
      0,C0,C2,3      ARM11: Set Attributes Register 3
      0,C0,C2,4      ARM11: Set Attributes Register 4
      0,C0,C2,5      ARM11: Set Attributes Register 5

      0,C1,C0,0      Control Register (R/W, or R=Fixed)
      0,C1,C0,1      ARM11: Auxiliary Control Register
      0,C1,C0,2      ARM11: Coprocessor Access Control Register
      0,C2,C0,0      ARM11: Translation Table Base Register 0
      0,C2,C0,1      ARM11: Translation Table Base Register 1
      0,C2,C0,2      ARM11: Translation Table Base Control Register
      0,C3,C0,0      ARM11: Domain Access Control Register
      0,C5,C0,0      ARM11: Data Fault Status Register
      0,C5,C0,1      ARM11: Instruction Fault Status Register
      0,C6,C0,0      ARM11: Fault Address Register (FAR)
      0,C6,C0,1      ARM11: Watchpoint Fault Address Register (WFAR)
      0,C2,C0,0      PU Cachability Bits for Data/Unified Protection Region
      0,C2,C0,1      PU Cachability Bits for Instruction Protection Region
      0,C3,C0,0      PU Cache Write-Bufferability Bits for Data Protection Regions
      0,C5,C0,0      PU Access Permission Data/Unified Protection Region
      0,C5,C0,1      PU Access Permission Instruction Protection Region
      0,C5,C0,2      PU Extended Access Permission Data/Unified Protection Region
      0,C5,C0,3      PU Extended Access Permission Instruction Protection Region
      0,C6,C0..C7,0  PU Protection Unit Data/Unified Region 0..7
      0,C6,C0..C7,1  PU Protection Unit Instruction Region 0..7
      0,C7,Cm,Op2    Cache Commands and Halt Function (W)
      0,C9,C0,0      Cache Data Lockdown
      0,C9,C0,1      Cache Instruction Lockdown
      0,C9,C1,0      TCM Data TCM Base and Virtual Size
      0,C9,C1,1      TCM Instruction TCM Base and Virtual Size
      0,C13,Cm,Op2   Misc Process ID registers
      0,C15,Cm,Op2   Misc Implementation Defined and Test/Debug registers

Data/Unified Registers
Some Cache/PU/TCM registers are declared as "Data/Unified".
That registers are used for Data accesses in case that the CPU contains separate Data and Instruction registers, otherwise the registers are used for both (unified) Data and Instruction accesses.

ARM CP15 ID Codes

C0,C0,0 - Main ID Register (R)

      12-15 ARM Era (0=Pre-ARM7, 7=ARM7, other=Post-ARM7)

Post-ARM7 Processors

      0-3   Revision Number
      4-15  Primary Part Number (Bit12-15 must be other than 0 or 7)
            (eg. 946h for ARM946)
      16-19 Architecture        (1=v4, 2=v4T, 3=v5, 4=v5T, 5=v5TE, 6=v6, ?=v7)
      20-23 Variant Number
      24-31 Implementor         (41h=ARM, 44h=Digital Equipment Corp, 69h=Intel)

ARM7 Processors

      0-3   Revision Number
      4-15  Primary Part Number (Bit12-15 must be 7)
      16-22 Variant Number
      23    Architecture        (0=v3, 1=v4T)
      24-31 Implementor         (41h=ARM, 44h=Digital Equipment Corp, 69h=Intel)

Pre-ARM7 Processors

      0-3   Revision Number
      4-11  Processor ID LSBs (30h=ARM3/v2, 60h,61h,62=ARM600,610,620/v3)
      12-31 Processor ID MSBs (fixed, 41560h)

Note: On the NDS9, this register is 41059461h (ARMv5TE, ARM946, rev1). NDS7 and GBA don't have CP15s.
C0,C0,1 - Cache Type Register (R)

      0-11  Instruction Cache (bits 0-1=len, 2=m, 3-5=assoc, 6-8=size, 9-11=zero)
      12-23 Data Cache        (bits 0-1=len, 2=m, 3-5=assoc, 6-8=size, 9-11=zero)
      24    Separate Cache Flag (0=Unified, 1=Separate Data/Instruction Caches)
      25-28 Cache Type (0,1,2,6,7=see below, other=reserved)
             Type Method         Cache cleaning         Cache lock-down
             0    Write-through  Not needed             Not supported
             1    Write-back     Read data block        Not supported
             2    Write-back     Register 7 operations  Not supported
             6    Write-back     Register 7 operations  Format A
             7    Write-back     Register 7 operations  Format B      ;<-- NDS9
      29-31 Reserved (zero)

The 12bit Instruction/Data values are decoded as shown below,

      Cache Absent  = (ASSOC=0 and M=1)       ;in that case overriding below
      Cache Size    = 200h+(100h*M) shl SIZE  ;min 0.5Kbytes, max 96Kbytes
      Associativity = (1+(0.5*M)) shl ASSOC   ;min 1-way,     max 192-way
      Line Length   = 8 shl LEN               ;min 8 bytes,   max 64 bytes

For Unified cache (Bit 24=0), Instruction and Data values are identical.
Note: On the NDS9, this register is 0F0D2112h (Code=2000h bytes, Data=1000h bytes, assoc=whatever, and line size 32 bytes each). NDS7 and GBA don't have CP15s (nor any code/data cache).
C0,C0,2 - Tightly Coupled Memory (TCM) Size Register (R)

      0-1   Reserved    (0)
      2     ITCM Absent (0=Present, 1=Absent)
      3-5   Reserved    (0)
      6-9   ITCM Size   (Size = 512 SHL N) (or 0=None)
      10-13 Reserved    (0)
      14    DTCM Absent (0=Present, 1=Absent)
      15-17 Reserved    (0)
      18-21 DTCM Size   (Size = 512 SHL N) (or 0=None)
      22-31 Reserved    (0)

Note: On the NDS9, this register is 00140180h (ITCM=8000h bytes, DTCM=4000h bytes)). NDS7 and GBA don't have CP15s (nor any ITCM/DTCM).
C0,C0,3..7 - Reserved (R)
Unused/Reserved registers, containing the same value as C0,C0,0.

ARM CP15 Control Register

C1,C0,0 - Control Register (R/W, or R=Fixed)

      0  MMU/PU Enable         (0=Disable, 1=Enable) (Fixed 0 if none)
      1  Alignment Fault Check (0=Disable, 1=Enable) (Fixed 0/1 if none/always on)
      2  Data/Unified Cache    (0=Disable, 1=Enable) (Fixed 0/1 if none/always on)
      3  Write Buffer          (0=Disable, 1=Enable) (Fixed 0/1 if none/always on)
      4  Exception Handling    (0=26bit, 1=32bit)    (Fixed 1 if always 32bit)
      5  26bit-address faults  (0=Enable, 1=Disable) (Fixed 1 if always 32bit)
      6  Abort Model (pre v4)  (0=Early, 1=Late Abort) (Fixed 1 if ARMv4 and up)
      7  Endian                (0=Little, 1=Big)     (Fixed 0/1 if fixed)
      8  System Protection bit (MMU-only)
      9  ROM Protection bit    (MMU-only)
      10 Implementation defined
      11 Branch Prediction     (0=Disable, 1=Enable)
      12 Instruction Cache     (0=Disable, 1=Enable) (ignored if Unified cache)
      13 Exception Vectors     (0=00000000h, 1=FFFF0000h)
      14 Cache Replacement     (0=Normal/PseudoRandom, 1=Predictable/RoundRobin)
      15 Pre-ARMv5 Mode        (0=Normal, 1=Pre ARMv5; LDM/LDR/POP_PC.Bit0/Thumb)
      16 DTCM Enable           (0=Disable, 1=Enable)
      17 DTCM Load Mode        (0=R/W, 1=DTCM Write-only)
      18 ITCM Enable           (0=Disable, 1=Enable)
      19 ITCM Load Mode        (0=R/W, 1=ITCM Write-only)
      20 Reserved              (0)
      21 Reserved              (0)
      22 Unaligned Access      (?=Enable unaligned access and mixed endian)
      23 Extended Page Table   (0=Subpage AP Bits Enabled, 1=Disabled)
      24 Reserved              (0)
      25 CPSR E on exceptions  (0=Clear E bit, 1=Set E bit)
      26 Reserved              (0)
      27 FIQ Behaviour         (0=Normal FIQ behaviour, 1=FIQs behave as NMFI)
      28 TEX Remap bit         (0=No remapping, 1=Remap registers used)
      29 Force AP              (0=Access Bit not used, 1=AP[0] used as Access bit)
      30 Reserved              (0)
      31 Reserved              (0)

Various bits in this register may be read-only (fixed 0 if unsupported, or fixed 1 if always activated).
On NDS ARM9, bit0,2,7,12..19 are R/W, bit3..6 are always set, all other bits are always zero.
On 3DS ARM11, bit0..2,8..9,11..13,15,22..23,25,28..29 are R/W, bit3..6,14,16,18 are always set, all other bits are always zero.

ARM CP15 Memory Managment Unit (MMU)

Nintendo consoles have a MMU on the ARM11 processor (in 3DS).
The MMU allows to assign virtual memory addresses, and to disable the data cache in sensitive memory areas (eg. I/O area, and memory that is shared for ARM9/ARM11). Additionally, it can trigger page fault exceptions (eg. for error handling or memory mapped files).
Related CP15 registers used in 3DS bootrom MMU init

      p15,0,c8,c5,0 ;Invalidate Instruction TLB               (=0)
      p15,0,c8,c6,0 ;Invalidate Data TLB                      (=0)
      p15,0,c2,c0,0 ;Translation Table Base 0 (for process)   (=1FFF4000h+2)
      p15,0,c2,c0,1 ;Translation Table Base 1 (for OS and I/O)(=1FFF4000h+2)
      p15,0,c2,c0,2 ;Translation Table Base Control           (=0)
      p15,0,c3,c0,0 ;Domain Access Control                    (=55555555h)
      p15,0,c1,c0,2 ;Coprocessor Access Control (unrelated?)  (=0F00000h)

MMU Tables
1st Level table (size 4000h) divides 4Gbyte address space into 1Mbyte sections
2nd Level table(s) (size 400h each) divides a 1Mbyte section into 4Kbyte pages

     ________________________________ ARMv6 Tables ________________________________

ARMv6 First-Level Page Table entries

       3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
       1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0
      |__Ignored__________________________________________________|0_0| Fault
      |__Second-Level-Table-Address_______________|P|Domain_|_SBZ_|0_1| Coarse
      |__Address______________|0|0|n_S_A|_TEX_|AP_|P|Domain_|X_C_B|1_0| Section 1MB
      |__Address______|___SBZ___|1|_SBZ_|_TEX_|AP_|P|Ignored|X_C_B|1_0| Super 16MB
      |___________________________________________________________|1_1| Reserved

BUG: The Supersections do probably also have "n,S,A" flags, probably in bit17-15, too (the 3DS bootrom seems to set those bits as so).
ARMv6 Second-Level Page Table entries

       3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
       1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0
      |__Ignored__________________________________________________|0_0| Fault
      |__Address______________________|X|_TEX_|n_S_A|_SBZ_|AP_|C_B|0_1| Large 64K
      |__Address______________________________|n_S_A|_TEX_|AP_|C_B|1_X| Small 4K

     ______________________________ Pre-ARMv6 Tables ______________________________

This is an older format, similar to the newer ARMv6 tables, but without the "n,S,A,X" bits, and, instead, somehow allowing to divide 4K pages into smaller 1K snippets (with separate access privileges in AP0/AP1/AP2/AP3 bits, but without TEX bits).
Backwards-compatible First-Level Page Table entries

       3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
       1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0
      |__Ignored__________________________________________________|0_0| Fault
      |__Second-Level-Table-Address_______________|P|Domain_|_SBZ_|0_1| Coarse
      |__Address______________|0|0|_SBZ_|_TEX_|AP_|P|Domain_|0_C_B|1_0| Section 1MB
      |__Address______|___SBZ___|1|_SBZ_|_TEX_|AP_|P|Ignored|0_C_B|1_0| Super 16MB
      |___________________________________________________________|1_1| Reserved

Backwards-compatible Second-Level Page Table entries

       3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
       1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0
      |__Ignored__________________________________________________|0_0| Fault
      |__Address______________________|_?TEX?_|AP3|AP2|AP1|AP0|C_B|0_1| Large 4x16K
      |__Address______________________________|AP3|AP2|AP1|AP0|C_B|1_0| Small 4x1K
      |__Address______________________________|_SBZ_|_TEX_|AP_|C_B|1_1| Extended 4K

BUG: The 4bit ?TEX? value is probably meant to be a 3bit TEX value, probably with an unused/zero bit; in bit15 or so.

     ___________________________________ Notes ___________________________________

Supersections and Large Pages
16Mbyte Supersections and 64Kbyte Large pages consist of 16 identical table entries. Which is basically same as 16 Sections or 16 Pages with continously increasing entries.
The advantage is internal caching: If one table entry is cached, then the hardware knows that the other 15 nearby entries are supposed to be same; and that they won't need to be loaded into internal cache.

ARM CP15 Protection Unit (PU)

Nintendo consoles have a PU on the ARM9 processor (in NDS, DSi, 3DS).
Protection Unit can be enabled in Bit0 of C1,C0,0 (Control Register).
C2,C0,0 - Cachability Bits for Data/Unified Protection Region (R/W)
C2,C0,1 - Cachability Bits for Instruction Protection Region (if any) (R/W)

      0-7  Cachable (C) bits for region 0-7
      8-31 Reserved/zero

C3,C0,0 - Cache Write-Bufferability Bits for Data Protection Regions (R/W)
Allows to select what to do when writing to a cached memory snippet:
Write-Through stores the data in the cache line (so subsequent cache reads return correct data), and additionally writes the data to underlaying memory.
Write-Back stores the data in the cache line only, and marks the line as dirty, but doesn't update the underlaying memory (underlaying memory is updated only when the CPU decides to use the cache line for other purposes, or when the user is manually "Cleaning" the cache line).

      0-7  Bufferable (B) bits for region 0-7  (0=Write-Through, 1=Write-Back)
      8-31 Reserved/zero

Instruction fetches are, obviously, always read-operations. So, there are no write-bufferability bits for Instruction Protection Regions.
Note: Unrelated to the "Cache Write-Bufferability", the ARM does also have a "Write Buffer" (a small FIFO that can queue only a few writes).
C5,C0,0 - Access Permission Data/Unified Protection Region (R/W)
C5,C0,1 - Access Permission Instruction Protection Region (if any) (R/W)
C5,C0,2 - Extended Access Permission Data/Unified Protection Region (R/W)
C5,C0,3 - Extended Access Permission Instruction Protection Region (if any) (R/W)
For C5,C0,0 and C5,C0,1:

      0-15  Access Permission (AP) bits for region 0-7 (Bits 0-1=AP0, 2-3=AP1, etc)
      16-31 Reserved/zero

For C5,C0,2 and C5,C0,3 (Extended):

      0-31  Access Permission (AP) bits for region 0-7 (Bits 0-3=AP0, 4-7=AP1, etc)

The possible AP settings (0-3 for C5,C0,0..1, or 0-15 for C5,C0,2..3) are:

      AP  Privileged User
      0   -          -
      1   R/W        -
      2   R/W        R
      3   R/W        R/W
      5   R          -
      6   R          R

Settings 5,6 only for Extended Registers, settings 4,7..15 are Reserved.
C6,C0..C7,0 - Protection Unit Data/Unified Region 0..7 (R/W)
C6,C0..C7,1 - Protection Unit Instruction Region 0..7 (R/W) if any

      0     Protection Region Enable (0=Disable, 1=Enable)
      1-5   Protection Region Size   (2 SHL X) ;min=(X=11)=4KB, max=(X=31)=4GB
      6-11  Reserved/zero
      12-31 Protection Region Base address (Addr = Y*4K; must be SIZE-aligned)

Overlapping Regions are allowed, Region 7 is having highest priority, region 0 lowest priority.
Background Region
Additionally, any memory areas outside of the eight Protection Regions are handled as Background Region, this region has neither Read nor Write access.
Unified Region Note
On the NDS, the Region registers are unified (C6,C0..C7,1 are read/write-able mirrors of C6,C0..C7,0). Nethertheless, the Cachabilty and Permission registers are NOT unified (separate registers exists for code and data settings).

ARM CP15 Cache Control

Cache is enabled/controlled by Bit 2,3,12,14 in Control Register.
Cache regions are controlled via Protection Unit (PU).
Cache type can be detected via Cache Type Register.
C7,C0..C15,0..7 - Cache Commands (W)
Write-only Cache Command Register. Cm,Op2 operands used to select a specific command, with parameter value in Rd.

      Cn,Cm,Op2 Rd   ARM9 Command
      C7,C0,4   0    Yes  Wait For Interrupt (Halt)
      C7,C5,0   0    Yes  Invalidate Entire Instruction Cache
      C7,C5,1   VA   Yes  Invalidate Instruction Cache Line
      C7,C5,2   S/I  -    Invalidate Instruction Cache Line
      C7,C5,4   0    -    Flush Prefetch Buffer
      C7,C5,6   0    -    Flush Entire Branch Target Cache
      C7,C5,7   IMP? -    Flush Branch Target Cache Entry
      C7,C6,0   0    Yes  Invalidate Entire Data Cache
      C7,C6,1   VA   Yes  Invalidate Data Cache Line
      C7,C6,2   S/I  -    Invalidate Data Cache Line
      C7,C7,0   0    -    Invalidate Entire Unified Cache
      C7,C7,1   VA   -    Invalidate Unified Cache Line
      C7,C7,2   S/I  -    Invalidate Unified Cache Line
      C7,C8,2   0    Yes  Wait For Interrupt (Halt), alternately to C7,C0,4
      C7,C10,1  VA   Yes  Clean Data Cache Line
      C7,C10,2  S/I  Yes  Clean Data Cache Line
      C7,C10,4  0    -    Drain Write Buffer
      C7,C11,1  VA   -    Clean Unified Cache Line
      C7,C11,2  S/I  -    Clean Unified Cache Line
      C7,C13,1  VA   Yes  Prefetch Instruction Cache Line
      C7,C14,1  VA   Yes  Clean and Invalidate Data Cache Line
      C7,C14,2  S/I  Yes  Clean and Invalidate Data Cache Line
      C7,C15,1  VA   -    Clean and Invalidate Unified Cache Line
      C7,C15,2  S/I  -    Clean and Invalidate Unified Cache Line

Parameter values (Rd) formats:

      0    Not used, should be zero
      VA   Virtual Address
      S/I  Set/index; Bit 31..(32-A) = Index, Bit (L+S-1)..L = Set ?

Note:

      Invalidate means to forget all data
      Clean means to write-back dirty cache lines to underlaying memory
      (Clean is important when having "Cache Write-Bufferability" enabled in PU)

C9,C0,0 - Data Cache Lockdown
C9,C0,1 - Instruction Cache Lockdown
(Width (W) of index field depends on cache ASSOCIATIVETY.)
Format A:

      0..(31-W)  Reserved/zero
      (32-W)..31 Lockdown Block Index

Format B:

      0..(W-1)   Lockdown Block Index
      W..30      Reserved/zero
      31         L

Cache/Write-buffer should not be enabled for the whole 4GB memory area, high-speed TCM memory doesn't require caching, and caching would have fatal results on I/O ports. So, cache can be used only in combination with the Protection Unit, which allows to enable/disable caching in specified regions.
Note
ARMv5 instruction set supports a Cache Prepare for Load opcode (PLD), see
ARM Opcodes: Memory: Single Data Transfer (LDR, STR, PLD)
Note
Data cache always requires PU/MMU. Code cache requires PU/MMU on ARM9, but also works without PU/MMU on ARM11.

ARM CP15 Tightly Coupled Memory (TCM)

TCM is high-speed memory, directly contained in the ARM CPU core.
TCM and DMA
TCM doesn't use the ARM bus. A minor disadvantage is that TCM cannot be accessed by DMA. However, the main advantage is that, when using TCM, the CPU can be kept running without any waitstates even while the bus is used for DMA transfers. Operation during DMA works only if all code/data is located in TCM, waitstates are generated if any code/data outside TCM is accessed; in worst case (if there are no gaps in the DMA) then the CPU is halted until the DMA finishes.
TCM and DMA and IRQ
No idea if/how IRQs are handled during DMA? Eventually (unlikely) code in TCM is kept executed until DMA finishes (ie. until the IRQ vector can be accessed. Eventually the IRQ vector is instantly accessed (causing to halt the CPU until DMA finishes). In both cases: Assuming that IRQs are enabled, and that the IRQ vector and/or IRQ handler are located outside TCM.
Separate Instruction (ITCM) and Data (DTCM) Memory
DTCM can be used only for Data accesses, typically used for stacks and other frequently accessed data.
ITCM is primarily intended for instruction accesses, but it can be also used for Data accesses (among others allowing to copy code to ITCM), however, performance isn't optimal when simultaneously accessing ITCM for code and data (such like opcodes in ITCM that use literal pool values in ITCM).
TCM Enable, TCM Load Mode
CP15 Control Register allows to enable ITCM and DTCM, and to switch ITCM/DTCM into Load Mode. In Load Mode (when TCM is enabled), TCM becomes write-only; this allows to read data from source addresses in main memory, and to write data to destination addresses in TCM by using the same addresses; useful for initializing TCM with overlapping source/dest addresses; Load mode works with all Load/Store opcodes, it does NOT work with SWP/SWPB opcodes.
TCM Physical Size can be detected in 3rd ID Code Register. (C0,C0,2)
C9,C1,0 - Data TCM Size/Base (R/W)
C9,C1,1 - Instruction TCM Size/Base (R/W)

      0     Reserved     (0)
      1-5   Virtual Size (Size = 512 SHL N) ;min=(N=3)=4KB, max=(N=23)=4GB
      6-11  Reserved     (0)
      12-31 Region Base  (Base = X SHL 12)  ;Base must be Size-aligned

The Virtual size settings should be normally same as the Physical sizes (see C0,C0,2). However, smaller sizes are allowed (using only the 1st some KB), as well as bigger sizes (TCM area is then filled with mirrors of physical TCM).
The ITCM region base may be fixed (read-only), for example, on the NDS, ITCM base is always 00000000h, nethertheless the virtual size may be changed (allowing to mirror ITCM to higher addresses).
If DTCM and ITCM do overlap, then ITCM appears to have priority.
TCM and PU
TCM can be used without Protection Unit.
When the protection unit is enabled, TCM is controlled by the PU just like normal memory, the PU should provide R/W Access Permission for TCM regions; cache and write-buffer are not required for high-speed TCM (so both should be disabled for TCM regions).

ARM CP15 Misc

C13,C0,0 - Process ID for Fast Context Switch Extension (FCSE) (R/W)

      0-24  Reserved/zero
      25-31 Process ID (PID) (0-127) (0=Disable)

The FCSE allows different processes (each assembled with ORG 0) to be located at virtual addresses in the 1st 32MB area. The FCSE splits the total 4GB address space into blocks of 32MB, accesses to Block(0) are redirected to Block(PID):

      IF addr<32M then addr=addr+PID*32M
      Respectively, with PID=0, the address remains unchanged (FCSE disabled).

The CPU-to-Memory address handling is shown below:

      1. CPU outputs a virtual address (VA)
      2. FCSE adjusts the VA to a modified virtual address (MVA)
      3. Cache hits determined by examining the MVA, continue below if no hit
      4. MMU translates MVA to physical address (PA) (if no MMU present: PA=MVA)
      5. Memory access occurs at PA

The FCSE allows limited virtual addressing even if no MMU is present.
If the MMU is present, then either the FCSE and/or the MMU can be used for virtual addressing; the advantage of using the FCSE (a single write to C13,C0,0) is less overload; using the MMU for the same purpose would require to change virtual address translation table in memory, and to flush the cache.
The NDS doesn't have a FCSE (the FCSE register is read-only, always zero).
C13,C0,1 - Trace Process ID (R/W)
C13,C1,1 - Trace Process ID (Mirror) (R/W)
This value is output to ETMPROCID pins (if any), allowing to notify external hardware about the currently executed process within multi-tasking programs.

      0-31  Process ID

C13,C1,1 is a mirror of C13,C0,1 (for compatibility with other ARM processors).
Both registers are read/write-able on NDS9, but there are no external pin-outs.
<cpopc>
Unlike for all other CP15 registers, the <cpopc> operand of the MRC/MCR opcodes isn't always zero for below registers, so below registers are using "cpopc,Cn,Cm,op2" notation (instead of the normal "Cn,Cm,op2" notation).
Built-In-Self-Test (BIST)
Allows to test internal memory (ie. TCM, Cache Memory, and Cache TAGs). The tests are filling (and verifying) the selected memory region thrice (once with the fillvalue, then with the inverted fillvalue, and then again with the fillvalue). The BIST functions are intended for diagnostics purposes only, not for use in normal program code (ARM doesn't guarantee future processors to have backwards compatible BIST functions).
0,C15,C0,1 - BIST TAG Control Register (R/W)
1,C15,C0,1 - BIST TCM Control Register (R/W)
2,C15,C0,1 - BIST Cache Control Register (R/W)

      0-15  Data Control (see below)
      16-31 Instruction Control (see below)

The above 16bit control values are:

      0     Start bit     (Write: 1=Start) (Read: 1=Busy)
      1     Pause bit     (1=Pause)
      2     Enable bit    (1=Enable)
      3     Fail Flag     (1=Error) (Read Only)
      4     Complete Flag (1=Ready) (Read Only)
      5-15  Size (2^(N+2) bytes) (min=N=1=8bytes, max=N=24=64MB)

Size and Pause are not supported in all implementations.
Caution: While and as long as the Enable bit is set, the corresponding memory region(s) will be disabled. Eg. when testing <either> DTCM <and/or> ITCM, <both> DTCM <and> ITCM are forcefully disabled in C1,C0,0 (Control Register), after the test the software must first clear the BIST enable bit, and then restore DTCM/ITCM bits in C1,C0,0. And of course, the content of the tested memory region must be restored when needed.
0,C15,C0,2 - BIST Instruction TAG Address (R/W)
1,C15,C0,2 - BIST Instruction TCM Address (R/W)
2,C15,C0,2 - BIST Instruction Cache Address (R/W)
0,C15,C0,6 - BIST Data TAG Address (R/W)
1,C15,C0,6 - BIST Data TCM Address (R/W)
2,C15,C0,6 - BIST Data Cache Address (R/W)

      0-31  Word-aligned Destination Address within Memory Block (eg. within ITCM)

On the NDS9, bit0-1, and bit21-31 are always zero.
0,C15,C0,3 - BIST Instruction TAG Fillvalue (R/W)
1,C15,C0,3 - BIST Instruction TCM Fillvalue (R/W)
2,C15,C0,3 - BIST Instruction Cache Fillvalue (R/W)
0,C15,C0,7 - BIST Data TAG Fillvalue (R/W)
1,C15,C0,7 - BIST Data TCM Fillvalue (R/W)
2,C15,C0,7 - BIST Data Cache Fillvalue (R/W)

      0-31  Fillvalue for BIST

After BIST, the selected memory region is filled by that value. That is, on the NDS9 at least, all words will be filled with the SAME value (ie. NOT with increasing or randomly generated numbers).
0,C15,C0,0 - Cache Debug Test State Register (R/W)

      0-8    Reserved (zero)
      9      Disable Instruction Cache Linefill
      10     Disable Data Cache Linefill
      11     Disable Instruction Cache Streaming
      12     Disable Data Cache Streaming
      13-31  Reserved (zero/unpredictable)

3,C15,C0,0 - Cache Debug Index Register (R/W)

      0..1    Reserved (zero)
      2..4    Word Address
      5..N    Index
      N+1..29 Reserved (zero)
      30..31  Segment

3,C15,C1,0 - Cache Debug Instruction TAG (R/W)
3,C15,C2,0 - Cache Debug Data TAG (R/W)
3,C15,C3,0 - Cache Debug Instruction Cache (R/W)
3,C15,C4,0 - Cache Debug Data Cache (R/W)

      0..1    Set
      2..3    Dirty Bits
      4       Valid
      5..N    Index
      N+1..31 TAG Address

ARM CPU Instruction Cycle Times

Instruction Cycle Summary

      Instruction      Cycles      Additional
      ---------------------------------------------------------------------
      ALU              1S          +1S+1N if R15 loaded, +1I if SHIFT(Rs)
      MSR,MRS          1S
      LDR              1S+1N+1I    +1S+1N if R15 loaded
      STR              2N
      LDM              nS+1N+1I    +1S+1N if R15 loaded
      STM              (n-1)S+2N
      SWP              1S+2N+1I
      BL (THUMB)       3S+1N
      B,BL             2S+1N
      SWI,trap         2S+1N
      MUL              1S+ml
      MLA              1S+(m+1)I
      MULL             1S+(m+1)I
      MLAL             1S+(m+2)I
      CDP              1S+bI
      LDC,STC          (n-1)S+2N+bI
      MCR              1N+bI+1C
      MRC              1S+(b+1)I+1C
      {cond} false     1S

ARM9:

      Q{D}ADD/SUB      1S+Interlock.
      CLZ              1S.
      LDR              1S+1N+1L
      LDRB,LDRH,LDRmis 1S+1N+2L
      LDR PC ...
      STR              1S+1N        (not 2N, and both in parallel)

Execution Time: 1S+Interlock (SMULxy,SMLAxy,SMULWx,SMLAWx)
Execution Time: 1S+1I+Interlock (SMLALxy)
ARM11:

      Observe that Branch Prediction (enabled in CP15 Control register) can affect
      timings for conditional jumps (and presumably non-conditional ones, too).
      Without prediction: A waitloop made of "SUBS+BNE" takes 4 clks per loop cycle
      With prediction: A waitloop made of "SUBS+BNE" takes 2.5 clks per loop cycle
      (apparently the prediction assumes 75% of the jumps to be taken)

Whereas,

      n = number of words transferred
      b = number of cycles spent in coprocessor busy-wait loop
      m = depends on most significant byte(s) of multiplier operand

Above 'trap' is meant to be the execution time for exceptions. And '{cond} false' is meant to be the execution time for conditional instructions which haven't been actually executed because the condition has been false.
The separate meaning of the N,S,I,C cycles is:
N - Non-sequential cycle
Requests a transfer to/from an address which is NOT related to the address used in the previous cycle. (Called 1st Access in GBA language).
The execution time for 1N is 1 clock cycle (plus non-sequential access waitstates).
S - Sequential cycle
Requests a transfer to/from an address which is located directly after the address used in the previous cycle. Ie. for 16bit or 32bit accesses at incrementing addresses, the first access is Non-sequential, the following accesses are sequential. (Called 2nd Access in GBA language).
The execution time for 1S is 1 clock cycle (plus sequential access waitstates).
I - Internal Cycle
CPU is just too busy, not even requesting a memory transfer for now.
The execution time for 1I is 1 clock cycle (without any waitstates).
C - Coprocessor Cycle
The CPU uses the data bus to communicate with the coprocessor (if any), but no memory transfers are requested.
Memory Waitstates
Ideally, memory may be accessed free of waitstates (1N and 1S are then equal to 1 clock cycle each). However, a memory system may generate waitstates for several reasons: The memory may be just too slow. Memory is currently accessed by DMA, eg. sound, video, memory transfers, etc. Or when data is squeezed through a 16bit data bus (in that special case, 32bit access may have more waitstates than 8bit and 16bit accesses). Also, the memory system may separate between S and N cycles (if so, S cycles would be typically faster than N cycles).
Memory Waitstates for Different Memory Areas
Different memory areas (eg. ROM and RAM) may have different waitstates. When executing code in one area which accesses data in another area, then the S+N cycles must be split into code and data accesses: 1N is used for data access, plus (n-1)S for LDM/STM, the remaining S+N are code access. If an instruction jumps to a different memory area, then all code cycles for that opcode are having waitstate characteristics of the NEW memory area (except Thumb BL which still executes 1S in OLD area).

ARM CPU Versions

Version Numbers
ARM CPUs are distributed by name ARM#, and are described as ARMv# in specifications, whereas "#" is NOT the same than "v#", for example, ARM7TDMI is ARMv4TM. That is so confusing, that ARM didn't even attempt to clarify the relationship between the various "#" and "v#" values.
Version Variants
Suffixes like "M" (long multiply), "T" (Thumb support), "E" (Enhanced DSP) indicate presence of special features, additionally to the standard instruction set of a given version, or, when preceded by an "x", indicate the absence of that features.
ARMv1 aka ARM1
Some sort of a beta version, according to ARM never been used in any commercial products.
ARMv2 and up
MUL,MLA
CDP,LDC,MCR,MRC,STC
SWP/SWPB (ARMv2a and up only)
Two new FIQ registers
ARMv3 and up
MRS,MSR opcodes (instead CMP/CMN/TST/TEQ{P} opcodes)
CPSR,SPSR registers (instead PSR bits in R15)
Removed never condition, cond=NV no longer valid
32bit addressing (instead 26bit addressing in older versions)
26bit addressing backwards comptibility mode (except v3G)
Abt and Und modes (instead handling aborts/undefined in Svc mode)
SMLAL,SMULL,UMLAL,UMULL (optionally, INCLUDED in v3M, EXCLUDED in v4xM/v5xM)
ARMv4 aka ARM7 and up
LDRH,LDRSB,LDRSH,STRH
Sys mode (privileged user mode)
BX (only ARMv4T, and any ARMv5 or ARMv5T and up)
THUMB code (only T variants, ie. ARMv4T, ARMv5T)
ARMv5 aka ARM9 and up
BKPT,BLX,CLZ (BKPT,BLX also in THUMB mode)
LDM/LDR/POP PC with mode switch (POP PC also in THUMB mode)
CDP2,LDC2,MCR2,MRC2,STC2 (new coprocessor opcodes)
C-flag unchanged by MUL (instead undefined flag value)
changed instruction cycle timings / interlock ??? or not ???
QADD,QDADD,QDSUB,QSUB opcodes, CPSR.Q flag (v5TE and V5TExP only)
SMLAxy,SMLALxy,SMLAWy,SMULxy,SMULWy (v5TE and V5TExP only)
LDRD,STRD,PLD,MCRR,MRRC (v5TE only, not v5, not v5TExP)
BXJ (jump to Jazelle bytecode) (v5TEJ only)
ARMv6 aka ARM11 and up (see ARM DDI 0100I)
Supports all ARMv5TEJ features (=including Jazelle?).
The following ARM instructions are added:
- CPS, SRS and RFE instructions for improved exception handling
- REV, REV16 and REVSH byte reversal instructions
- SETEND for a revised endian (memory) model
- LDREX and STREX exclusive access instructions
- SXTB, SXTH, UXTB, UXTH byte/halfword extend instructions
- A set of Single Instruction Multiple Data (SIMD) media instructions
- Additional forms of multiply with accumulation into a 64-bit result
The following Thumb instructions are added:
- CPS, CPY (a form of MOV), REV, REV16, REVSH, SETEND, SXTB, SXTH, UXTB, UXTH
SWP/SWPB has been deprecated in ARMv6, made optional in ARMv7 (with the possibility of disabling it if still available), and removed in ARMv8.
ARMv6K aka "ARM11 MPCore" (see ARM DDI 0360F) (used in 3DS)
Unknown how this is abbreviated (ARMv6-M would be something else: Cortex-M).
The MPCore processor provides support for extensions to ARMv6 that include:
- LDREX/STREX{B|H|D} for 8bit/16bit/64bit and CLREX
- HINT (TrueNOP, YIELD, WFI, WFE, SEV)
- Architectural remap registers.
- Revised use of TEX remap bits. The ARMv6 MMU page table descriptors use a large number of bits to describe all of the options for inner and outer cachability. In reality, no application requires all of these options simultaneously. Therefore it is possible to use the TEX remap mechanism to configure the MP11 CPUs to support only a small number of options. This implies a level of indirection in the page table mappings.
The TEX CB encoding table provides two OS managed page table bits. For binary compatibility with existing ARMv6 ports of OSs, this gives a separate mode of operation of the MMU. This is called the TEX Remap configuration and is controlled by bit [28] TR in CP15 Register 1.
- Revised use of AP bits. In the MP11 CPUs the APX and AP[1:0] encoding b111 is Privileged or User mode read-only access. AP[0] indicates an abort type, Access Bit fault, when CP15 c1[29] is 1.
For more information see the ARM Architecture Reference Manual.
ARMv6T2 aka THUMB-2
This doesn't seem to be supported in 3DS. THUMB-2 adds more 2x16bit opcodes in THUMB mode, ie. THUMB code can contain classic 16bit opcodes, mixed with new 2x16bit opcodes. As far as I understand, the old 2x16bit "BL" and "BLX" do no longer exists, or are replaced by differently encode THUMB-2 opcodes?
ARMv6Z
ARMv6K with Security Extensions. Aka TrustZone, see Processor Feature Register 1.
A Milestone in Computer History
Original ARMv2 has been used in the relative rare and expensive Archimedes deluxe home computers in the late eighties, the Archimedes has caught a lot of attention, particularly for being the first home computer that used a BIOS being programmed in BASIC language - which has been a absolutely revolutionary decadency at that time.
Inspired, programmers all over the world have successfully developed even slower and much more inefficient programming languages, which are nowadays consequently used by nearly all ARM programmers, and by most non-ARM programmers as well.

ARM CPU Data Sheet

This present document is an attempt to supply a brief ARM7TDMI reference, hopefully including all information which is relevant for programmers.
Some details that I have treated as meaningless for GBA programming aren't included - such like Big Endian format, and Virtual Memory data aborts, and most of the chapters listed below.
Have a look at the complete data sheet (URL see below) for more detailed verbose information about ARM7TDMI instructions. That document also includes:

     - Signal Description
       Pins of the original CPU, probably other for GBA.
     - Memory Interface
       Optional virtual memory circuits, etc. not for GBA.
     - Coprocessor Interface
       As far as I know, none such in GBA.
     - Debug Interface
       For external hardware-based debugging.
     - ICEBreaker Module
       For external hardware-based debugging also.
     - Instruction Cycle Operations
       Detailed: What happens during each cycle of each instruction.
     - DC Parameters (Power supply)
     - AC Parameters (Signal timings)

The official ARM7TDMI data sheet can be downloaded from ARMs webpage,

      http://www.arm.com/Documentation/UserMans/PDF/ARM7TDMI.html

Be prepared for bloated PDF Format, approx 1.3 MB, about 200 pages.

BIOS Functions

The BIOS includes several System Call Functions which can be accessed by SWI instructions. Incoming parameters are usually passed through registers R0,R1,R2,R3. Outgoing registers R0,R1,R3 are typically containing either garbage, or return value(s). All other registers (R2,R4-R14) are kept unchanged.
Caution
When invoking SWIs from inside of ARM state specify SWI NN*10000h, instead of SWI NN as in THUMB state.
Overview
BIOS Function Summary
BIOS Differences between GBA and NDS functions
All Functions Described
BIOS Arithmetic Functions
BIOS Rotation/Scaling Functions
BIOS Decompression Functions
BIOS Memory Copy
BIOS Halt Functions
BIOS Reset Functions
BIOS Misc Functions
BIOS Multi Boot (Single Game Pak)
BIOS Sound Functions
BIOS SHA1 Functions (DSi only)
BIOS RSA Functions (DSi only)
3DS bootroms
BIOS 3DS Exception Vectors
RAM Usage, BIOS Dumps
BIOS RAM Usage
BIOS Dumping
How BIOS Processes SWIs
SWIs can be called from both within THUMB and ARM mode. In ARM mode, only the upper 8bit of the 24bit comment field are interpreted.
Each time when calling a BIOS function 4 words (SPSR, R11, R12, R14) are saved on Supervisor stack (_svc). Once it has saved that data, the SWI handler switches into System mode, so that all further stack operations are using user stack.
In some cases the BIOS may allow interrupts to be executed from inside of the SWI procedure. If so, and if the interrupt handler calls further SWIs, then care should be taken that the Supervisor Stack does not overflow.

BIOS Function Summary

      GBA  NDS7 NDS9 DSi7 DSi9 Basic Functions
      00h  00h  00h  -    -    SoftReset
      01h  -    -    -    -    RegisterRamReset
      02h  06h  06h  06h  06h  Halt
      03h  07h  -    07h  -    Stop/Sleep
      04h  04h  04h  04h  04h  IntrWait       ;DSi7/DSi9: both bugged?
      05h  05h  05h  05h  05h  VBlankIntrWait ;DSi7/DSi9: both bugged?
      06h  09h  09h  09h  09h  Div
      07h  -    -    -    -    DivArm
      08h  0Dh  0Dh  0Dh  0Dh  Sqrt
      09h  -    -    -    -    ArcTan
      0Ah  -    -    -    -    ArcTan2
      0Bh  0Bh  0Bh  0Bh  0Bh  CpuSet
      0Ch  0Ch  0Ch  0Ch  0Ch  CpuFastSet
      0Dh  -    -    -    -    GetBiosChecksum
      0Eh  -    -    -    -    BgAffineSet
      0Fh  -    -    -    -    ObjAffineSet
      GBA  NDS7 NDS9 DSi7 DSi9 Decompression Functions
      10h  10h  10h  10h  10h  BitUnPack
      11h  11h  11h  11h  11h  LZ77UnCompReadNormalWrite8bit   ;"Wram"
      12h  -    -    -    -    LZ77UnCompReadNormalWrite16bit  ;"Vram"
      -    -    -    01h  01h  LZ77UnCompReadByCallbackWrite8bit
      -    12h  12h  02h  02h  LZ77UnCompReadByCallbackWrite16bit
      -    -    -    19h  19h  LZ77UnCompReadByCallbackWrite16bit (same as above)
      13h  -    -    -    -    HuffUnCompReadNormal
      -    13h  13h  13h  13h  HuffUnCompReadByCallback
      14h  14h  14h  14h  14h  RLUnCompReadNormalWrite8bit     ;"Wram"
      15h  -    -    -    -    RLUnCompReadNormalWrite16bit    ;"Vram"
      -    15h  15h  15h  15h  RLUnCompReadByCallbackWrite16bit
      16h  -    16h  -    16h  Diff8bitUnFilterWrite8bit       ;"Wram"
      17h  -    -    -    -    Diff8bitUnFilterWrite16bit      ;"Vram"
      18h  -    18h  -    18h  Diff16bitUnFilter
      GBA  NDS7 NDS9 DSi7 DSi9 Sound (and Multiboot/HardReset/CustomHalt)
      19h  08h  -    08h  -    SoundBias
      1Ah  -    -    -    -    SoundDriverInit
      1Bh  -    -    -    -    SoundDriverMode
      1Ch  -    -    -    -    SoundDriverMain
      1Dh  -    -    -    -    SoundDriverVSync
      1Eh  -    -    -    -    SoundChannelClear
      1Fh  -    -    -    -    MidiKey2Freq
      20h  -    -    -    -    SoundWhatever0
      21h  -    -    -    -    SoundWhatever1
      22h  -    -    -    -    SoundWhatever2
      23h  -    -    -    -    SoundWhatever3
      24h  -    -    -    -    SoundWhatever4
      25h  -    -    -    -    MultiBoot
      26h  -    -    -    -    HardReset
      27h  1Fh  -    1Fh  -    CustomHalt
      28h  -    -    -    -    SoundDriverVSyncOff
      29h  -    -    -    -    SoundDriverVSyncOn
      2Ah  -    -    -    -    SoundGetJumpList
      GBA  NDS7 NDS9 DSi7 DSi9 New NDS Functions
      -    03h  03h  03h  03h  WaitByLoop
      -    0Eh  0Eh  0Eh  0Eh  GetCRC16
      -    0Fh  0Fh  -    -    IsDebugger
      -    1Ah  -    1Ah  -    GetSineTable
      -    1Bh  -    1Bh  -    GetPitchTable (DSi7: bugged)
      -    1Ch  -    1Ch  -    GetVolumeTable
      -    1Dh  -    1Dh  -    GetBootProcs (DSi7: only 1 proc)
      -    -    1Fh  -    1Fh  CustomPost
      GBA  NDS7 NDS9 DSi7 DSi9 New DSi Functions (RSA/SHA1)
      -    -    -    20h  20h  RSA_Init_crypto_heap
      -    -    -    21h  21h  RSA_Decrypt
      -    -    -    22h  22h  RSA_Decrypt_Unpad
      -    -    -    23h  23h  RSA_Decrypt_Unpad_OpenPGP_SHA1
      -    -    -    24h  24h  SHA1_Init
      -    -    -    25h  25h  SHA1_Update
      -    -    -    26h  26h  SHA1_Finish
      -    -    -    27h  27h  SHA1_Init_update_fin
      -    -    -    28h  28h  SHA1_Compare_20_bytes
      -    -    -    29h  29h  SHA1_Random_maybe
      GBA  NDS7 NDS9 DSi7 DSi9 Invalid Functions
      2Bh+ 20h+ 20h+ -    -    Crash (SWI xxh..FFh do jump to garbage addresses)
      -    xxh  xxh  -    -    Jump to 0   (on any SWI numbers not listed above)
      -    -    -    12h  12h  No function (ignored)
      -    -    -    2Bh  2Bh  No function (ignored)
      -    -    -    40h+ 40h+ Mirror      (SWI 40h..FFh mirror to 00h..3Fh)
      -    -    -    xxh  xxh  Hang        (on any SWI numbers not listed above)

Invalid NDS functions: NDS7 SWI 01h, 02h, 0Ah, 16h-19h, 1Eh, and NDS9 SWI 01h, 02h, 07h, 08h, 0Ah, 17h, 19h-1Eh will jump to zero (ie. to the NDS7 reset vector, or to NDS9 unused (usually PU-locked ITCM) memory, which will be both redirected to the debug handler, if any).
Invalid DSi functions: DSi9 SWI 00h, 07h-08h, 0Ah, 0Fh, 17h, 1Ah-1Eh, 2Ah, 2Ch-3Fh do hang in endless loop.

BIOS Differences between GBA and NDS functions

Differences between GBA and NDS BIOS functions
- SoftReset uses different addresses
- SWI numbers for Halt, Stop/Sleep, Div, Sqrt have changed
- Halt destroys r0 on NDS9, IntrWait bugged on NDS9
- CpuFastSet allows 4-byte blocks (nice), but...
- CpuFastSet works very SLOW because of a programming bug (uncool)
- Some of the decompression functions are now using callbacks
- SoundBias uses new delay parameter
And, a number of GBA functions have been removed, and some new NDS functions have been added, see:
BIOS Function Summary

BIOS Arithmetic Functions

Div
DivArm
Sqrt
ArcTan
ArcTan2
SWI 06h (GBA) or SWI 09h (NDS7/NDS9/DSi7/DSi9) - Div
Signed Division, r0/r1.

      r0  signed 32bit Number
      r1  signed 32bit Denom

Return:

      r0  Number DIV Denom ;signed
      r1  Number MOD Denom ;signed
      r3  ABS (Number DIV Denom) ;unsigned

For example, incoming -1234, 10 should return -123, -4, +123.
The function usually gets caught in an endless loop upon division by zero.
Note: The NDS9 and DSi9 additionally support hardware division, by math coprocessor, accessed via I/O Ports, however, the SWI function is a raw software division.
SWI 07h (GBA) - DivArm
Same as above (SWI 06h Div), but incoming parameters are exchanged, r1/r0 (r0=Denom, r1=number). For compatibility with ARM's library. Slightly slower (3 clock cycles) than SWI 06h.
SWI 08h (GBA) or SWI 0Dh (NDS7/NDS9/DSi7/DSi9) - Sqrt
Calculate square root.

      r0   unsigned 32bit number

Return:

      r0   unsigned 16bit number

The result is an integer value, so Sqrt(2) would return 1, to avoid this inaccuracy, shift left incoming number by 2*N as much as possible (the result is then shifted left by 1*N). Ie. Sqrt(2 shl 30) would return 1.41421 shl 15.
Note: The NDS9 and DSi9 additionally support hardware square root calculation, by math coprocessor, accessed via I/O Ports, however, the SWI function is a raw software calculation.
SWI 09h (GBA) - ArcTan
Calculates the arc tangent.

      r0   Tan, 16bit (1bit sign, 1bit integral part, 14bit decimal part)

Return:

      r0   "-PI/2<THETA/<PI/2" in a range of C000h-4000h.

Note: there is a problem in accuracy with "THETA<-PI/4, PI/4<THETA".
SWI 0Ah (GBA) - ArcTan2
Calculates the arc tangent after correction processing.
Use this in normal situations.

      r0   X, 16bit (1bit sign, 1bit integral part, 14bit decimal part)
      r1   Y, 16bit (1bit sign, 1bit integral part, 14bit decimal part)

Return:

      r0   0000h-FFFFh for 0<=THETA<2PI.

BIOS Rotation/Scaling Functions

BgAffineSet
ObjAffineSet
SWI 0Eh (GBA) - BgAffineSet
Used to calculate BG Rotation/Scaling parameters.

      r0   Pointer to Source Data Field with entries as follows:
            s32  Original data's center X coordinate (8bit fractional portion)
            s32  Original data's center Y coordinate (8bit fractional portion)
            s16  Display's center X coordinate
            s16  Display's center Y coordinate
            s16  Scaling ratio in X direction (8bit fractional portion)
            s16  Scaling ratio in Y direction (8bit fractional portion)
            u16  Angle of rotation (8bit fractional portion) Effective Range 0-FFFF
      r1   Pointer to Destination Data Field with entries as follows:
            s16  Difference in X coordinate along same line
            s16  Difference in X coordinate along next line
            s16  Difference in Y coordinate along same line
            s16  Difference in Y coordinate along next line
            s32  Start X coordinate
            s32  Start Y coordinate
      r2   Number of Calculations

Return: No return value, Data written to destination address.
SWI 0Fh (GBA) - ObjAffineSet
Calculates and sets the OBJ's affine parameters from the scaling ratio and angle of rotation.
The affine parameters are calculated from the parameters set in Srcp.
The four affine parameters are set every Offset bytes, starting from the Destp address.
If the Offset value is 2, the parameters are stored contiguously. If the value is 8, they match the structure of OAM.
When Srcp is arrayed, the calculation can be performed continuously by specifying Num.

      r0   Source Address, pointing to data structure as such:
            s16  Scaling ratio in X direction (8bit fractional portion)
            s16  Scaling ratio in Y direction (8bit fractional portion)
            u16  Angle of rotation (8bit fractional portion) Effective Range 0-FFFF
      r1   Destination Address, pointing to data structure as such:
            s16  Difference in X coordinate along same line
            s16  Difference in X coordinate along next line
            s16  Difference in Y coordinate along same line
            s16  Difference in Y coordinate along next line
      r2   Number of calculations
      r3   Offset in bytes for parameter addresses (2=continuous, 8=OAM)

Return: No return value, Data written to destination address.
For both Bg- and ObjAffineSet, Rotation angles are specified as 0-FFFFh (covering a range of 360 degrees), however, the GBA BIOS recurses only the upper 8bit; the lower 8bit may contain a fractional portion, but it is ignored by the BIOS.

BIOS Decompression Functions

BitUnPack
Diff8bitUnFilter
HuffUnComp
LZ77UnComp
RLUnComp
Decompression Read/Write Variants

      ReadNormal:      Fast (src must be memory mapped)
      ReadByCallback:  Slow (src can be non-memory, eg. serial Firmware SPI bus)
      Write8bitUnits:  Fast (dest must support 8bit writes, eg. not VRAM)
      Write16bitUnits: Slow (dest must be halfword-aligned) (for VRAM)

BitUnPack - SWI 10h (GBA/NDS7/NDS9/DSi7/DSi9)
Used to increase the color depth of bitmaps or tile data. For example, to convert a 1bit monochrome font into 4bit or 8bit GBA tiles. The Unpack Info is specified separately, allowing to convert the same source data into different formats.

      r0  Source Address      (no alignment required)
      r1  Destination Address (must be 32bit-word aligned)
      r2  Pointer to UnPack information:
           16bit  Length of Source Data in bytes     (0-FFFFh)
           8bit   Width of Source Units in bits      (only 1,2,4,8 supported)
           8bit   Width of Destination Units in bits (only 1,2,4,8,16,32 supported)
           32bit  Data Offset (Bit 0-30), and Zero Data Flag (Bit 31)
          The Data Offset is always added to all non-zero source units.
          If the Zero Data Flag was set, it is also added to zero units.

Data is written in 32bit units, Destination can be Wram or Vram. The size of unpacked data must be a multiple of 4 bytes. The width of source units (plus the offset) should not exceed the destination width.
Return: No return value, Data written to destination address.
Diff8bitUnFilterWrite8bit (Wram) - SWI 16h (GBA/NDS9/DSi9)
Diff8bitUnFilterWrite16bit (Vram) - SWI 17h (GBA)
Diff16bitUnFilter - SWI 18h (GBA/NDS9/DSi9)
These aren't actually real decompression functions, destination data will have exactly the same size as source data. However, assume a bitmap or wave form to contain a stream of increasing numbers such like 10..19, the filtered/unfiltered data would be:

      unfiltered:   10  11  12  13  14  15  16  17  18  19
      filtered:     10  +1  +1  +1  +1  +1  +1  +1  +1  +1

In this case using filtered data (combined with actual compression algorithms) will obviously produce better compression results.
Data units may be either 8bit or 16bit used with Diff8bit or Diff16bit functions respectively.

      r0  Source address (must be aligned by 4) pointing to data as follows:
           Data Header (32bit)
             Bit 0-3   Data size (must be 1 for Diff8bit, 2 for Diff16bit)
             Bit 4-7   Type (must be 8 for DiffFiltered)
             Bit 8-31  24bit size after decompression
           Data Units (each 8bit or 16bit depending on used SWI function)
             Data0          ;original data
             Data1-Data0    ;difference data
             Data2-Data1    ;...
             Data3-Data2
             ...
      r1  Destination address

Return: No return value, Data written to destination address.
HuffUnCompReadNormal - SWI 13h (GBA)
HuffUnCompReadByCallback - SWI 13h (NDS/DSi)
The decoder starts in root node, the separate bits in the bitstream specify if the next node is node0 or node1, if that node is a data node, then the data is stored in memory, and the decoder is reset to the root node. The most often used data should be as close to the root node as possible. For example, the 4-byte string "Huff" could be compressed to 6 bits: 10-11-0-0, with root.0 pointing directly to data "f", and root.1 pointing to a child node, whose nodes point to data "H" and data "u".
Data is written in units of 32bits, if the size of the compressed data is not a multiple of 4, please adjust it as much as possible by padding with 0.
Align the source address to a 4Byte boundary.

      r0  Source Address, aligned by 4, pointing to:
           Data Header (32bit)
             Bit0-3   Data size in bit units (normally 4 or 8)
             Bit4-7   Compressed type (must be 2 for Huffman)
             Bit8-31  24bit size of decompressed data in bytes
           Tree Size (8bit)
             Bit0-7   Size of Tree Table/2-1 (ie. Offset to Compressed Bitstream)
           Tree Table (list of 8bit nodes, starting with the root node)
            Root Node and Non-Data-Child Nodes are:
             Bit0-5   Offset to next child node,
                      Next child node0 is at (CurrentAddr AND NOT 1)+Offset*2+2
                      Next child node1 is at (CurrentAddr AND NOT 1)+Offset*2+2+1
             Bit6     Node1 End Flag (1=Next child node is data)
             Bit7     Node0 End Flag (1=Next child node is data)
            Data nodes are (when End Flag was set in parent node):
             Bit0-7   Data (upper bits should be zero if Data Size is less than 8)
           Compressed Bitstream (stored in units of 32bits)
             Bit0-31  Node Bits (Bit31=First Bit)  (0=Node0, 1=Node1)
      r1  Destination Address
      r2  Callback temp buffer      ;\for NDS/DSi "ReadByCallback" variants only
      r3  Callback structure        ;/(see Callback notes below)

Return: No return value, Data written to destination address.
LZ77UnCompReadNormalWrite8bit (Wram) - SWI 11h (GBA/NDS7/NDS9/DSi7/DSi9)
LZ77UnCompReadNormalWrite16bit (Vram) - SWI 12h (GBA)
LZ77UnCompReadByCallbackWrite8bit - SWI 01h (DSi7/DSi9)
LZ77UnCompReadByCallbackWrite16bit - SWI 12h (NDS), SWI 02h or 19h (DSi)
Expands LZ77-compressed data. The Wram function is faster, and writes in units of 8bits. For the Vram function the destination must be halfword aligned, data is written in units of 16bits.
LZ Decompression Functions
CAUTION: Writing 16bit units to [dest-1] instead of 8bit units to [dest] means that reading from [dest-1] won't work, ie. the "Vram" function works only with disp=001h..FFFh, but not with disp=000h.
If the size of the compressed data is not a multiple of 4, please adjust it as much as possible by padding with 0. Align the source address to a 4-Byte boundary.

      r0  Source address, pointing to data as such:
           Data header (32bit)
             Bit 0-3   Reserved (0)
             Bit 4-7   Compressed type (must be 1 for LZ77)
             Bit 8-31  Size of decompressed data
           Repeat below. Each Flag Byte followed by eight Blocks.
           Flag data (8bit)
             Bit 0-7   Type Flags for next 8 Blocks, MSB first
           Block Type 0 - Uncompressed - Copy 1 Byte from Source to Dest
             Bit 0-7   One data byte to be copied to dest
           Block Type 1 - Compressed - Copy N+3 Bytes from Dest-Disp-1 to Dest
             Bit 0-3   Disp MSBs
             Bit 4-7   Number of bytes to copy (minus 3)
             Bit 8-15  Disp LSBs
      r1  Destination address
      r2  Callback parameter        ;\for NDS/DSi "ReadByCallback" variants only
      r3  Callback structure        ;/(see Callback notes below)

Return: No return value.
RLUnCompReadNormalWrite8bit (Wram) - SWI 14h (GBA/NDS7/NDS9/DSi7/DSi9)
RLUnCompReadNormalWrite16bit (Vram) - SWI 15h (GBA)
RLUnCompReadByCallbackWrite16bit - SWI 15h (NDS7/NDS9/DSi7/DSi9)
Expands run-length compressed data. The Wram function is faster, and writes in units of 8bits. For the Vram function the destination must be halfword aligned, data is written in units of 16bits.
If the size of the compressed data is not a multiple of 4, please adjust it as much as possible by padding with 0. Align the source address to a 4Byte boundary.

      r0  Source Address, pointing to data as such:
           Data header (32bit)
             Bit 0-3   Reserved
             Bit 4-7   Compressed type (must be 3 for run-length)
             Bit 8-31  Size of decompressed data
           Repeat below. Each Flag Byte followed by one or more Data Bytes.
           Flag data (8bit)
             Bit 0-6   Expanded Data Length (uncompressed N-1, compressed N-3)
             Bit 7     Flag (0=uncompressed, 1=compressed)
           Data Byte(s) - N uncompressed bytes, or 1 byte repeated N times
      r1  Destination Address
      r2  Callback parameter        ;\for NDS/DSi "ReadByCallback" variants only
      r3  Callback structure        ;/(see Callback notes below)

Return: No return value, Data written to destination address.
NDS/DSi Decompression Callbacks
On NDS and DSi, the "ReadByCallback" variants are reading source data from callback functions (rather than directly from memory). The callback functions may read normal data from memory, or from other devices, such like directly from the gamepak bus, without storing the source data in memory. The downside is that the callback mechanism makes the function very slow, furthermore, NDS7/NDS9 SWI 12h, 13h, 15h are using THUMB code, and variables on stack, alltogether that makes the whole shit very-very-very slow.

      r2 = user defined callback parameter (passed on to Open function)
            (or, for Huffman: pointer to temp buffer, max 200h bytes needed)
      r3 = pointer to callback structure

Callback structure (five 32bit pointers to callback functions)

      Open_and_get_32bit (eg. LDR r0,[r0], get header)
      Close              (optional, 0=none)
      Get_8bit           (eg. LDRB r0,[r0])
      Get_16bit          (not used)
      Get_32bit          (used by Huffman only)

All functions may use ARM or THUMB code (indicated by address bit0). The current source address (r0) is passed to all callback functions. Additionally, the initial destination address (r1), and a user defined parameter (r2) are passed to the Open function. For Huffman r2 must point to a temp buffer (max 200h bytes needed, internally used by the SWI function to make a copy of the huffman tree; needed for random-access to the tree, which wouldn't work with the sequentially reading callbacks).
All functions have return values in r0. The Open function normally returns the first word (containing positive length and type), alternatively it may return a negative error code to abort/reject decompression. The Close function, if it is defined, should return zero (or any positive value), or a negative errorcode. The other functions return raw data, without errorcodes. The SWI returns the length of decompressed data, or the signed errorcode from the Open/Close functions.

BIOS Memory Copy

CpuFastSet
CpuSet
SWI 0Ch (GBA/NDS7/NDS9/DSi7/DSi9) - CpuFastSet
Memory copy/fill in units of 32 bytes. Memcopy is implemented as repeated LDMIA/STMIA [Rb]!,r2-r9 instructions. Memfill as single LDR followed by repeated STMIA [Rb]!,r2-r9.
After processing all 32-byte-blocks, the NDS/DSi additonally processes the remaining words as 4-byte blocks. BUG: The NDS/DSi uses the fast 32-byte-block processing only for the first N bytes (not for the first N words), so only the first quarter of the memory block is FAST, the remaining three quarters are SLOWLY copied word-by-word.
The length is specifed as wordcount, ie. the number of bytes divided by 4.
On the GBA, the length should be a multiple of 8 words (32 bytes) (otherwise the GBA is forcefully rounding-up the length). On NDS/DSi, the length may be any number of words (4 bytes).

      r0    Source address        (must be aligned by 4)
      r1    Destination address   (must be aligned by 4)
      r2    Length/Mode
              Bit 0-20  Wordcount (GBA: rounded-up to multiple of 8 words)
              Bit 24    Fixed Source Address (0=Copy, 1=Fill by WORD[r0])

Return: No return value, Data written to destination address.
SWI 0Bh (GBA/NDS7/NDS9/DSi7/DSi9) - CpuSet
Memory copy/fill in units of 4 bytes or 2 bytes. Memcopy is implemented as repeated LDMIA/STMIA [Rb]!,r3 or LDRH/STRH r3,[r0,r5] instructions. Memfill as single LDMIA or LDRH followed by repeated STMIA [Rb]!,r3 or STRH r3,[r0,r5].
The length must be a multiple of 4 bytes (32bit mode) or 2 bytes (16bit mode). The (half)wordcount in r2 must be length/4 (32bit mode) or length/2 (16bit mode), ie. length in word/halfword units rather than byte units.

      r0    Source address        (must be aligned by 4 for 32bit, by 2 for 16bit)
      r1    Destination address   (must be aligned by 4 for 32bit, by 2 for 16bit)
      r2    Length/Mode
              Bit 0-20  Wordcount (for 32bit), or Halfwordcount (for 16bit)
              Bit 24    Fixed Source Address (0=Copy, 1=Fill by {HALF}WORD[r0])
              Bit 26    Datasize (0=16bit, 1=32bit)

Return: No return value, Data written to destination address.
Note: On GBA, NDS7 and DSi7, these two functions will silently reject to do anything if the source start or end addresses are reaching into the BIOS area. The NDS9 and DSi9 don't have such read-proctections.

BIOS Halt Functions

Halt
IntrWait
VBlankIntrWait
Stop/Sleep
CustomHalt
SWI 02h (GBA) or SWI 06h (NDS7/NDS9/DSi7/DSi9) - Halt
Halts the CPU until an interrupt request occurs. The CPU is switched into low-power mode, all other circuits (video, sound, timers, serial, keypad, system clock) are kept operating.
Halt mode is terminated when any enabled interrupts are requested, that is when (IE AND IF) is not zero, the GBA locks up if that condition doesn't get true. However, the state of CPUs IRQ disable bit in CPSR register, and the IME register are don't care, Halt passes through even if either one has disabled interrupts.
On GBA and NDS7/DSi7, Halt is implemented by writing to HALTCNT, Port 4000301h. On NDS9/DSi9, Halt is implemted by writing to System Control Coprocessor (mov p15,0,c7,c0,4,r0 opcode), this opcode hangs if IME=0.
No parameters, no return value.
(GBA/NDS7/DSi7: all registers unchanged, NDS9/DSi9: R0 destroyed)
SWI 04h (GBA/NDS7/NDS9/DSi7/DSi9) - IntrWait ;DSi7/DSi9=bugged?
Continues to wait in Halt state until one (or more) of the specified interrupt(s) do occur. The function forcefully sets IME=1. When using multiple interrupts at the same time, this function is having less overhead than repeatedly calling the Halt function.

      r0    0=Return immediately if an old flag was already set (NDS9: bugged!)
            1=Discard old flags, wait until a NEW flag becomes set
      r1    Interrupt flag(s) to wait for (same format as IE/IF registers)
      r2    DSi7 only: Extra flags (same format as DSi7's IE2/IF2 registers)

Caution: When using IntrWait or VBlankIntrWait, the user interrupt handler MUST update the BIOS Interrupt Flags value in RAM; when acknowleding processed interrupt(s) by writing a value to the IF register, the same value should be also ORed to the BIOS Interrupt Flags value, at following memory location:

      Host     GBA (16bit)  NDS7 (32bit)  NDS9 (32bit)  DSi7-IF2 (32bit)
      Address  [3007FF8h]   [380FFF8h]    [DTCM+3FF8h]  [380FFC0h]

NDS9: BUG: No Discard (r0=0) doesn't work. The function always waits for at least one IRQ to occur (no matter which, including IRQs that are not selected in r1), even if the desired flag was already set. NB. the same bug is also found in the GBA/NDS7 functions, but it's compensated by a second bug, ie. the GBA/NDS7 functions are working okay because their "bug doesn't work".
Return: No return value, the selected flag(s) are automatically reset in BIOS Interrupt Flags value in RAM upon return.
DSi9: BUG: The function tries to enter Halt state via Port 4000301h (which would be okay on ARM7, but it's probably ignored on ARM9, which should normally use CP15 to enter Halt state; if Port 4000301h is really ignored, then the function will "successfully" wait for interrupts, but without actually entering any kind of low power mode).
DSi7: BUG: The function tries to wait for IF and IF2 interrupts, but it does accidently ignore the old IF interrupts, and works only with new IF2 ones.
SWI 05h (GBA/NDS7/NDS9/DSi7/DSi9) - VBlankIntrWait ;DSi7/DSi9=bugged?
Continues to wait in Halt status until a new V-Blank interrupt occurs.
The function sets r0=1 and r1=1 (plus r2=0 on DSi7) and does then execute IntrWait (SWI 04h), see IntrWait for details.
No parameters, no return value.
SWI 03h (GBA) - Stop
Switches the GBA into very low power mode (to be used similar as a screen-saver). The CPU, System Clock, Sound, Video, SIO-Shift Clock, DMAs, and Timers are stopped.
Stop state can be terminated by the following interrupts only (as far as enabled in IE register): Joypad, Game Pak, or General-Purpose-SIO.
"The system clock is stopped so the IF flag is not set."
Preparation for Stop:
Disable Video before implementing Stop (otherwise Video just freezes, but still keeps consuming battery power). Possibly required to disable Sound also? Obviously, it'd be also recommended to disable any external hardware (such like Rumble or Infra-Red) as far as possible.
No parameters, no return value.
SWI 07h (NDS7/DSi7) - Sleep
No info, probably similar as GBA SWI 03h (Stop). Sleep is implemented for ARM7 only, not for ARM9. But maybe the ARM7 function does stop <both> ARM7 and ARM9 (?)
SWI 27h (GBA) or SWI 1Fh (NDS7/DSi7) - CustomHalt (Undocumented)
Writes the 8bit parameter value to HALTCNT, below values are equivalent to Halt and Stop/Sleep functions, other values reserved, purpose unknown.

      r2  8bit parameter (GBA: 00h=Halt, 80h=Stop) (NDS7/DSi7: 80h=Halt, C0h=Sleep)

No return value.

BIOS Reset Functions

SoftReset
RegisterRamReset
HardReset
SWI 00h (GBA/NDS7/NDS9) - SoftReset
Clears 200h bytes of RAM (containing stacks, and BIOS IRQ vector/flags), initializes system, supervisor, and irq stack pointers, sets R0-R12, LR_svc, SPSR_svc, LR_irq, and SPSR_irq to zero, and enters system mode.
Note that the NDS9 stack registers are hardcoded (the DTCM base should be set to the default setting of 0800000h). The NDS9 function additionally flushes caches and write buffer, and sets the CP15 control register to 12078h.

      Host  sp_svc    sp_irq    sp_sys    zerofilled area       return address
      GBA   3007FE0h  3007FA0h  3007F00h  [3007E00h..3007FFFh]  Flag[3007FFAh]
      NDS7  380FFDCh  380FFB0h  380FF00h  [380FE00h..380FFFFh]  Addr[27FFE34h]
      NDS9  0803FC0h  0803FA0h  0803EC0h  [DTCM+3E00h..3FFFh]   Addr[27FFE24h]

The NDS7/NDS9 return addresses at [27FFE34h/27FFE24h] are usually containing copies of Cartridge Header [034h/024h] entry points, which may select ARM/THUMB state via bit0. The GBA return address 8bit flag is interpreted as 00h=8000000h (ROM), or 01h-FFh=2000000h (RAM), entered in ARM state.
Note: The reset is applied only to the CPU that has executed the SWI (ie. on the NDS, the other CPU will remain unaffected).
Return: Does not return to calling procedure, instead, loads the above return address into R14, and then jumps to that address by a "BX R14" opcode.
SWI 01h (GBA) - RegisterRamReset
Resets the I/O registers and RAM specified in ResetFlags. However, it does not clear the CPU internal RAM area from 3007E00h-3007FFFh.

      r0  ResetFlags
           Bit   Expl.
           0     Clear 256K on-board WRAM  ;-don't use when returning to WRAM
           1     Clear 32K on-chip WRAM    ;-excluding last 200h bytes
           2     Clear Palette
           3     Clear VRAM
           4     Clear OAM              ;-zerofilled! does NOT disable OBJs!
           5     Reset SIO registers    ;-switches to general purpose mode!
           6     Reset Sound registers
           7     Reset all other registers (except SIO, Sound)

Return: No return value.
Bug: LSBs of SIODATA32 are always destroyed, even if Bit5 of R0 was cleared.
The function always switches the screen into forced blank by setting DISPCNT=0080h (regardless of incoming R0, screen becomes white).
SWI 26h (GBA) - HardReset (Undocumented)
This function reboots the GBA (including for getting through the time-consuming nintendo intro, which is making the function particularly useless and annoying).
Parameters: None. Return: Never/Reboot.
Execution Time: About 2 seconds (!)

BIOS Misc Functions

GetBiosChecksum
WaitByLoop
GetCRC16
IsDebugger
GetSineTable
GetPitchTable
GetVolumeTable
CustomPost
GetBootProcs
SWI 0Dh (GBA) - GetBiosChecksum (Undocumented)
Calculates the checksum of the BIOS ROM (by reading in 32bit units, and adding up these values). IRQ and FIQ are disabled during execution.
The checksum is BAAE187Fh (GBA and GBA SP), or BAAE1880h (NDS/3DS in GBA mode, whereas the only difference is that the byte at [3F0Ch] is changed from 00h to 01h, otherwise the BIOS is 1:1 same as GBA BIOS, it does even include multiboot code).
Parameters: None. Return: r0=Checksum.
SWI 03h (NDS7/NDS9/DSi7/DSi9) - WaitByLoop
Performs a "LOP: SUB R0,1 / BGT LOP" wait loop, the loop is executed in BIOS memory, which provides reliable timings (regardless of the memory waitstates & cache state of the calling procedure). Intended only for short delays (eg. flash memory programming cycles).

      r0  Delay value (should be in range 1..7FFFFFFFh)

Execution time varies for ARM7 vs ARM9. On ARM9 it does also depend on whether ROM is cached, and on DSi it does further depended on the ARM9 CPU clock, and on whether using NDS or DSi BIOS ROM (NDS uses faster THUMB code, whilst DSi uses ARM code, which is slow on uncached ARM9 ROM reads). For example, to get a 1 millisecond delay, use following values:

      CPU  Clock     Cache   BIOS     Value for 1ms
      ARM7 33.51MHz  none    NDS/DSi  r0=20BAh    ;=20BAh  ;-ARM7
      ARM9 67.03MHz  on      NDS/DSi  r0=20BAh*2  ;=4174h  ;\ARM9 with cache
      ARM9 134.06MHz on      DSi      r0=20BAh*4  ;=82E8h  ;/
      ARM9 67.03MHz  off     NDS      r0=20BAh/2  ;=105Dh  ;\
      ARM9 67.03MHz  off     DSi      r0=20BAh/4  ;=082Eh  ; ARM9 without cache
      ARM9 134.06MHz off     DSi      r0=20BAh/3  ;=0AE8h  ;/

Return: No return value.
SWI 0Eh (NDS7/NDS9/DSi7/DSi9) - GetCRC16

      r0  Initial CRC value (16bit, usually FFFFh)
      r1  Start Address   (must be aligned by 2)
      r2  Length in bytes (must be aligned by 2)

CRC16 checksums can be calculated as such:

      val[0..7] = C0C1h,C181h,C301h,C601h,CC01h,D801h,F001h,A001h
      for i=start to end
        crc=crc xor byte[i]
        for j=0 to 7
          crc=crc shr 1:if carry then crc=crc xor (val[j] shl (7-j))
        next j
      next i

Return:

      r0  Calculated 16bit CRC Value

Additionally, if the length is nonzero, r3 contains the last processed halfword at [addr+len-2]. Unlike most other NDS7/DSi7 SWI functions (which do reject reading from BIOS memory), this allows to dump the NDS7/DSi7 BIOS (except for the memory region that is locked via BIOSPROT Port 4000308h).
SWI 0Fh (NDS7/NDS9) - IsDebugger
Detects if 4MB (normal) or 8MB (debug version) Main RAM installed.
Caution: Fails on ARM9 when cache is enabled (always returns 8MB state).
Return: r0 = result (0=normal console 4MB, 1=debug version 8MB)
Destroys halfword at [27FFFFAh] (NDS7) or [27FFFF8h] (NDS9)!
The SWI 0Fh function doesn't work stable if it gets interrupted by an interrupt which is calling SWI 0Fh, which would destroy the above halfword scratch value (unless the IRQ handler has saved/restored the halfword).
SWI 1Ah (NDS7/DSi7) - GetSineTable

      r0  Index (0..3Fh) (must be in that range, otherwise returns garbage)

Return: r0 = Desired Entry (0000h..7FF5h) ;SIN(0 .. 88.6 degrees)*8000h
SWI 1Bh (NDS7/DSi7) - GetPitchTable (DSi7: bugged)

      r0  Index (0..2FFh) (must be in that range, otherwise returns garbage)

BUG: DSi7 accidently reads from SineTable instead of PitchTable, as workaround for obtaining PitchTable values, one can set "r0=(0..2FFh)-46Ah" on DSi.
Return: r0 = Desired Entry (0000h..FF8Ah) (unsigned)
SWI 1Ch (NDS7/DSi7) - GetVolumeTable

      r0  Index (0..2D3h) (must be in that range, otherwise returns garbage)

Return: r0 = Desired Entry (00h..7Fh) (unsigned)
SWI 1Fh (NDS9/DSi9) - CustomPost
Writes to the POSTFLG register, probably for use by Firmware boot procedure.

      r0  32bit value, to be written to POSTFLG, Port 4000300h

Return: No return value.
SWI 1Dh (NDS7/DSi7) - GetBootProcs
Returns addresses of Gamecart boot procedure/interrupt handler, probably for use by Firmware boot procedure. Most of the returned NDS7 functions won't work if the POSTFLG register is set.
The return values are somewhat XORed by each other (on DSi7 most of the values are zero; which does rather negate the XORing effect, and, as a special gimmick, one of the zero values is XORed by incoming r2).

BIOS Multi Boot (Single Game Pak)

MultiBoot
SWI 25h (GBA) - MultiBoot
This function uploads & starts program code to slave GBAs, allowing to launch programs on slave units even if no cartridge is inserted into the slaves (this works because all GBA BIOSes contain built-in download procedures in ROM).
However, the SWI 25h BIOS upload function covers only 45% of the required Transmission Protocol, the other 55% must be coded in the master cartridge (see Transmission Protocol below).

      r0  Pointer to MultiBootParam structure
      r1  Transfer Mode (undocumented)
           0=256KHz, 32bit, Normal mode    (fast and stable)
           1=115KHz, 16bit, MultiPlay mode (default, slow, up to three slaves)
           2=2MHz,   32bit, Normal mode    (fastest but maybe unstable)
      Note: HLL-programmers that are using the MultiBoot(param_ptr) macro cannot
      specify the transfer mode and will be forcefully using MultiPlay mode.

Return:

      r0  0=okay, 1=failed

See below for more details.
Multiboot Parameter Structure
Size of parameter structure should be 4Ch bytes (the current GBA BIOS uses only first 44h bytes though). The following entries must be set before calling SWI 25h:

      Addr Size Name/Expl.
      14h  1    handshake_data (entry used for normal mode only)
      19h  3    client_data[1,2,3]
      1Ch  1    palette_data
      1Eh  1    client_bit (Bit 1-3 set if child 1-3 detected)
      20h  4    boot_srcp  (typically 8000000h+0C0h)
      24h  4    boot_endp  (typically 8000000h+0C0h+length)

The transfer length (excluding header data) should be a multiple of 10h, minimum length 100h, max 3FF40h (ca. 256KBytes). Set palette_data as "81h+color*10h+direction*8+speed*2", or as "0f1h+color*2" for fixed palette, whereas color=0..6, speed=0..3, direction=0..1. The other entries (handshake_data, client_data[1-3], and client_bit) must be same as specified in Transmission Protocol (see below hh,cc,y).
Multiboot Transfer Protocol
Below describes the complete transfer protocol, normally only the Initiation part must be programmed in the master cartridge, the main data transfer can be then performed by calling SWI 25h, the slave program is started after SWI 25h completion.
The ending handshake is normally not required, when using it, note that you will need custom code in BOTH master and slave programs.

      Times  Send   Receive  Expl.
      -----------------------Required Transfer Initiation in master program
      ...    6200   FFFF     Slave not in multiplay/normal mode yet
      1      6200   0000     Slave entered correct mode now
      15     6200   720x     Repeat 15 times, if failed: delay 1/16s and restart
      1      610y   720x     Recognition okay, exchange master/slave info
      60h    xxxx   NN0x     Transfer C0h bytes header data in units of 16bits
      1      6200   000x     Transfer of header data completed
      1      620y   720x     Exchange master/slave info again
      ...    63pp   720x     Wait until all slaves reply 73cc instead 720x
      1      63pp   73cc     Send palette_data and receive client_data[1-3]
      1      64hh   73uu     Send handshake_data for final transfer completion
      -----------------------Below is SWI 25h MultiBoot handler in BIOS
      DELAY  -      -        Wait 1/16 seconds at master side
      1      llll   73rr     Send length information and receive random data[1-3]
      LEN    yyyy   nnnn     Transfer main data block in units of 16 or 32 bits
      1      0065   nnnn     Transfer of main data block completed, request CRC
      ...    0065   0074     Wait until all slaves reply 0075 instead 0074
      1      0065   0075     All slaves ready for CRC transfer
      1      0066   0075     Signalize that transfer of CRC follows
      1      zzzz   zzzz     Exchange CRC must be same for master and slaves
      -----------------------Optional Handshake (NOT part of master/slave BIOS)
      ...    ....   ....     Exchange whatever custom data

Legend for above Protocol

      y     client_bit, bit(s) 1-3 set if slave(s) 1-3 detected
      x     bit 1,2,or 3 set if slave 1,2,or 3
      xxxx  header data, transferred in 16bit (!) units (even in 32bit normal mode)
      nn    response value for header transfer, decreasing 60h..01h
      pp    palette_data
      cc    random client_data[1..3] from slave 1-3, FFh if slave not exists
      hh    handshake_data, 11h+client_data[1]+client_data[2]+client_data[3]
      uu    random data, not used, ignore this value

Below automatically calculated by SWI 25h BIOS function (don't care about)

      llll  download length/4-34h
      rr    random data from each slave for encryption, FFh if slave not exists
      yyyy  encoded data in 16bit (multiplay) or 32bit (normal mode) units
      nnnn  response value, lower 16bit of destadr in GBA memory (00C0h and up)
      zzzz  16bit download CRC value, must be same for master and slaves

Pseudo Code for SWI 25h Transfer with Checksum and Encryption calculations

      if normal_mode    then c=C387h:x=C37Bh:k=43202F2Fh
      if multiplay_mode then c=FFF8h:x=A517h:k=6465646Fh
      m=dword(pp,cc,cc,cc):f=dword(hh,rr,rr,rr)
      for ptr=000000C0h to (file_size-4) step 4
        c=c xor data[ptr]:for i=1 to 32:c=c shr 1:if carry then c=c xor x:next
        m=(6F646573h*m)+1
        send_32_or_2x16 (data[ptr] xor (-2000000h-ptr) xor m xor k)
      next
      c=c xor f:for i=1 to 32:c=c shr 1:if carry then c=c xor x:next
      wait_all_units_ready_for_checksum:send_32_or_1x16 (c)

Whereas, explained: c=chksum,x=chkxor,f=chkfin,k=keyxor,m=keymul
Multiboot Communication
In Multiplay mode, master sends 16bit data, and receives 16bit data from each slave (or FFFFh if none). In Normal mode, master sends 32bit data (upper 16bit zero, lower 16bit as for multiplay mode), and receives 32bit data (upper 16bit as for multiplay mode, and lower 16bit same as lower 16bit previously sent by master). Because SIODATA32 occupies same addresses as SIOMULTI0-1, the same transfer code can be used for both multiplay and normal mode (in normal mode SIOMULTI2-3 should be forced to FFFFh though). After each transfer, master should wait for Start bit cleared in SIOCNT register, followed by a 36us delay.
Note: The multiboot slave would also recognize data being sent in Joybus mode, however, master GBAs cannot use joybus mode (because GBA hardware cannot act as master in joybus mode).
Multiboot Slave Header
The transferred Header block is written to 2000000-20000BFh in slave RAM, the header must contain valid data (identically as for normal ROM-cartridge headers, including a copy of the Nintendo logo, correct header CRC, etc.), in most cases it'd be recommended just to transfer a copy of the master cartridges header from 8000000h-80000BFh.
Multiboot Slave Program/Data
The transferred main program/data block is written to 20000C0h and up (max 203FFFFh) in slave RAM, note that absolute addresses in the program must be then originated at 2000000h rather than 8000000h. In case that the master cartridge is 256K or less, it could just transfer a copy of the whole cartridge at 80000C0h and up, the master should then copy & execute its own ROM data into RAM as well.
Multiboot Slave Extended Header
For Multiboot slaves, separate Entry Point(s) must be defined at the beginning of the Program/Data block (the Entry Point in the normal header is ignored), also some reserved bytes in this section are overwritten by the Multiboot procedure. For more information see chapter about Cartridge Header.
Multiboot Slave with Cartridge
Beside for slaves without cartridge, multiboot can be also used for slaves which do have a cartridge inserted, if so, SELECT and START must be kept held down during power-on in order to switch the slave GBA into Multiboot mode (ie. to prevent it from starting the cartridge as normally).
The general idea is to enable newer programs to link to any existing older GBA programs, even if these older programs originally didn't have been intended to support linking.
The uploaded program may access the slaves SRAM, Flash ROM, or EEPROM (if any, allowing to read out or modify slave game positions), as well as cartridge ROM at 80000A0h-8000FFFh (the first 4KBytes, excluding the nintendo logo, allowing to read out the cartridge name from the header, for example).
The main part of the cartridge ROM is meant to be locked out in order to prevent software pirates from uploading "intruder" programs which would send back a copy of the whole cartridge to the master, however, for good or evil, at present time, current GBA models and GBA carts do not seem to contain any such protection.
Uploading Programs from PC
Beside for the ability to upload a program from one GBA to another, this feature can be also used to upload small programs from a PC to a GBA. For more information see chapter about External Connectors.
Nintendo DS
The GBA multiboot function requires a link port, and so, works on GBA and GBA SP only. The Nintendo DS in GBA mode does include the multiboot BIOS function, but it won't be of any use as the DS doesn't have a link port.

BIOS Sound Functions

MidiKey2Freq
SoundBias
SoundChannelClear
SoundDriverInit
SoundDriverMain
SoundDriverMode
SoundDriverVSync
SoundDriverVSyncOff
SoundDriverVSyncOn
SoundWhatever0..4
SoundGetJumpList
SWI 1Fh (GBA) - MidiKey2Freq
Calculates the value of the assignment to ((SoundArea)sa).vchn[x].fr when playing the wave data, wa, with the interval (MIDI KEY) mk and the fine adjustment value (halftones=256) fp.

      r0  WaveData* wa
      r1  u8 mk
      r2  u8 fp

Return:

      r0  u32

This function is particularly popular because it allows to read from BIOS memory without copy protection range checks. The formula to read one byte (a) from address (i, 0..3FFF) is:
a = (MidiKey2Freq(i-(((i AND 3)+1)OR 3), 168, 0) * 2) SHR 24
SWI 19h (GBA) or SWI 08h (NDS7/DSi7) - SoundBias
Increments or decrements the current level of the SOUNDBIAS register (with short delays) until reaching the desired new level. The upper bits of the register are kept unchanged.

      r0   BIAS level (0=Level 000h, any other value=Level 200h)
      r1   Delay Count (NDS/DSi only) (GBA uses a fixed delay count of 8)

Return: No return value.
SWI 1Eh (GBA) - SoundChannelClear
Clears all direct sound channels and stops the sound.
This function may not operate properly when the library which expands the sound driver feature is combined afterwards. In this case, do not use it.
No parameters, no return value.
SWI 1Ah (GBA) - SoundDriverInit
Initializes the sound driver. Call this only once when the game starts up.
It is essential that the work area already be secured at the time this function is called.
You cannot execute this driver multiple times, even if separate work areas have been prepared.

      r0  Pointer to work area for sound driver, SoundArea structure as follows:
           SoundArea (sa) Structure
            u32    ident      Flag the system checks to see whether the
                              work area has been initialized and whether it
                              is currently being accessed.
            vu8    DmaCount   User access prohibited
            u8     reverb     Variable for applying reverb effects to direct sound
            u16    d1         User access prohibited
            void   (*func)()  User access prohibited
            int    intp       User access prohibited
            void*  NoUse      User access prohibited
            SndCh  vchn[MAX]  The structure array for controlling the direct
                              sound channels (currently 8 channels are
                              available). The term "channel" here does
                              not refer to hardware channels, but rather to
                              virtual constructs inside the sound driver.
            s8     pcmbuf[PCM_BF*2]
           SoundChannel Structure
            u8         sf     The flag indicating the status of this channel.
                              When 0 sound is stopped.
                              To start sound, set other parameters and
                              then write 80h to here.
                              To stop sound, logical OR 40h for a
                              release-attached off (key-off), or write zero
                              for a pause. The use of other bits is
                              prohibited.
            u8         r1     User access prohibited
            u8         rv     Sound volume output to right side
            u8         lv     Sound volume output to left side
            u8         at     The attack value of the envelope. When the
                              sound starts, the volume begins at zero and
                              increases every 1/60 second. When it
                              reaches 255, the process moves on to the
                              next decay value.
            u8         de     The decay value of the envelope. It is
                              multiplied by "this value/256" every 1/60
                              sec. and when sustain value is reached, the
                              process moves to the sustain condition.
            u8         su     The sustain value of the envelope. The
                              sound is sustained by this amount.
                              (Actually, multiplied by rv/256, lv/256 and
                              output left and right.)
            u8         re     The release value of the envelope. Key-off
                              (logical OR 40h in sf) to enter this state.
                              The value is multiplied by "this value/256"
                              every 1/60 sec. and when it reaches zero,
                              this channel is completely stopped.
            u8         r2[4]  User access prohibited
            u32        fr     The frequency of the produced sound.
                              Write the value obtained with the
                              MidiKey2Freq function here.
            WaveData*  wp     Pointer to the sound's waveform data. The waveform
                              data can be generated automatically from the AIFF
                              file using the tool (aif2agb.exe), so users normally
                              do not need to create this themselves.
            u32        r3[6]  User access prohibited
            u8         r4[4]  User access prohibited
           WaveData Structure
            u16   type    Indicates the data type. This is currently not used.
            u16   stat    At the present time, non-looped (1 shot) waveform
                          is 0000h and forward loop is 4000h.
            u32   freq    This value is used to calculate the frequency.
                          It is obtained using the following formula:
                          sampling rate x 2^((180-original MIDI key)/12)
            u32   loop    Loop pointer (start of loop)
            u32   size    Number of samples (end position)
            s8    data[]  The actual waveform data. Takes (number of samples+1)
                          bytes of 8bit signed linear uncompressed data. The last
                          byte is zero for a non-looped waveform, and the same
                          value as the loop pointer data for a looped waveform.

Return: No return value.
SWI 1Ch (GBA) - SoundDriverMain
Main of the sound driver.
Call every 1/60 of a second. The flow of the process is to call SoundDriverVSync, which is explained later, immediately after the V-Blank interrupt.
After that, this routine is called after BG and OBJ processing is executed.
No parameters, no return value.
SWI 1Bh (GBA) - SoundDriverMode
Sets the sound driver operation mode.

      r0  Sound driver operation mode
           Bit    Expl.
           0-6    Direct Sound Reverb value (0-127, default=0) (ignored if Bit7=0)
           7      Direct Sound Reverb set (0=ignore, 1=apply reverb value)
           8-11   Direct Sound Simultaneously-produced (1-12 channels, default 8)
           12-15  Direct Sound Master volume (1-15, default 15)
           16-19  Direct Sound Playback Frequency (1-12 = 5734,7884,10512,13379,
                  15768,18157,21024,26758,31536,36314,40137,42048, def 4=13379 Hz)
           20-23  Final number of D/A converter bits (8-11 = 9-6bits, def. 9=8bits)
           24-31  Not used.

Return: No return value.
SWI 1Dh (GBA) - SoundDriverVSync
An extremely short system call that resets the sound DMA. The timing is extremely critical, so call this function immediately after the V-Blank interrupt every 1/60 second.
No parameters, no return value.
SWI 28h (GBA) - SoundDriverVSyncOff
Due to problems with the main program if the V-Blank interrupts are stopped, and SoundDriverVSync cannot be called every 1/60 a second, this function must be used to stop sound DMA.
Otherwise, even if you exceed the limit of the buffer the DMA will not stop and noise will result.
No parameters, no return value.
SWI 29h (GBA) - SoundDriverVSyncOn
This function restarts the sound DMA stopped with the previously described SoundDriverVSyncOff.
After calling this function, have a V-Blank occur within 2/60 of a second and call SoundDriverVSync.
No parameters, no return value.
SWI 20h..24h (GBA) - SoundWhatever0..4 (Undocumented)
Whatever undocumented sound-related BIOS functions.
SWI 2Ah (GBA) - SoundGetJumpList (Undocumented)
Receives pointers to 36 additional sound-related BIOS functions.

      r0  Destination address (must be aligned by 4) (120h bytes buffer)

BIOS SHA1 Functions (DSi only)

SHA1_Init(struct)
SHA1_Update(struct,src,srclen)
SHA1_Finish(dst,struct)
SHA1_Init_Update_Finish(dst,src,srclen)
SHA1_Init_Update_Finish_Mess(dst,dstlen,src,srclen)
SHA1_Compare_20_Bytes(src1,src2)
SHA1_Default_Callback(struct,src,len)
SWI 24h (DSi9/DSi7) - SHA1_Init(struct)
Initializes a 64h-byte structure for SHA1 calculations:

      [struct+00h] = 67452301h      ;\
      [struct+04h] = EFCDAB89h      ;
      [struct+08h] = 98BADCFEh      ; initial SHA1 checksum value
      [struct+0Ch] = 10325476h      ;
      [struct+10h] = C3D2E1F0h      ;/
      [struct+14h] = 00000000h ;lsw ;\total len in bits, initially zero
      [struct+18h] = 00000000h ;msw ;/
      [struct+1Ch] = uninitialzed   ;-buffer for incomplete fragment (40h bytes)
      [struct+5Ch] = 00000000h      ;-incomplete fragment size
      if [struct+60h] = 00000000h then [struct+60h] = SHA1_Default_Callback

Observe that the incoming [struct+60h] value should be 00000000h, otherwise the default callback isn't installed (using a different callback doesn't make too much sense, and it's probably not done by any DSi programs) (the callback feature might be intended to mount hardware accelleration, or to hook, customize, encrypt, or replace the SHA1 functionality).
SWI 25h (DSi9/DSi7) - SHA1_Update(struct,src,srclen)
This function should be placed between Init and Finish. The Update function can be called multiple times if the source data is split into separate blocks. There's no alignment requirement (though the function works faster if src is 4-byte aligned).

      [struct+14h]=[struct+14h]+len*8  ;64bit value ;-raise total len in bits
      if [struct+5Ch]<>0 and [struct+5Ch]+len>=40h  ;\
        for i=[struct+5Ch] to 3Fh                   ; merge old incomplete chunk
          [struct+1Ch+i]=[src], src=src+1, len=len-1; with new data and process it
        SHA1_Callback(struct,struct+1Ch,40h)        ; (if it gives a full chunk)
        [struct+5Ch]=0                              ;/
      if len>=40h then                              ;\process full 40h-byte chunks
        SHA1_Callback(struct,src,len AND NOT 3Fh)   ; (if src isn't 4-byte aligned
        src=src+(len AND NOT 3Fh)                   ; then the DSi BIOS internally
        len=len AND 3Fh                             ;/copies all chunks to struct)
      if len>0 then                                 ;\
        for i=[struct+5Ch] to [struct+5Ch]+len-1    ; memorize remaining bytes
          [struct+1Ch+i]=[src], src=src+1, len=len-1; as incomplete chunk
          [struct+5Ch]=[struct+5Ch]+1               ;/

SWI 26h (DSi9/DSi7) - SHA1_Finish(dst,struct)

      [total_len]=bswap8byte([struct+14h]) ;get total len in bits in big-endian
      SHA1_Update(struct,value_80h,1)                            ;append end byte
      while [struct+5Ch]<>38h do SHA1_Update(struct,value_00h,1) ;append padding
      SHA1_Update(struct,total_len,8)                            ;append 64bit len
      [struct+14h]=bswap8byte([total_len]) ;restore total len, exclude above update
      [dst+00h]=bswap([struct+00h]  ;msw   ;\
      [dst+04h]=bswap([struct+04h]         ; store SHA1 result at dst
      [dst+08h]=bswap([struct+08h]         ; (in big-endian)
      [dst+0Ch]=bswap([struct+0Ch]         ;
      [dst+10h]=bswap([struct+10h]  ;lsw   ;/

SHA1_Default_Callback(struct,src,len)

      for j=1 to len/40h
        a=[struct+0], b=[struct+4], c=[struct+8], d=[struct+0Ch], e=[struct+10h]
        for i=0 to 79
          if i=0..15  then w[i] = bswap([src]), src=src+4
          if i=16..79 then w[i] = (w[i-3] xor w[i-8] xor w[i-14] xor w[i-16]) rol 1
          if i=0..19  then f=5A827999h + e + (d xor (b and (c xor d)))
          if i=20..39 then f=6ED9EBA1h + e + (b xor c xor d)
          if i=40..59 then f=8F1BBCDCh + e + ((b and c) or (d and (b or c)))
          if i=60..79 then f=CA62C1D6h + e + (b xor c xor d)
          e=d, d=c, c=(b ror 2), b=a, a=f + (a rol 5) + w[i]
        [struct+0]=[struct+0]+a, [struct+4]=[struct+4]+b, [struct+8]=[struct+8]+c
        [struct+0Ch]=[struct+0Ch]+d, [struct+10h]=[struct+10h]+e

SWI 27h (DSi9/DSi7) - SHA1_Init_Update_Finish(dst,src,srclen)

      [struct+60h]=00000000h  ;want Init to install the default SHA1 callback
      SHA1_Init(struct)
      SHA1_Update(struct,src,srclen)
      SHA1_Finish(dst,struct)

Always returns r0=1.
SWI 29h (DSi9/DSi7) - SHA1_Init_Update_Finish_Mess(dst,dstlen,src,srclen)

      if dst=0 then exit(r0=1)  ;uh, that's same return value as when okay
      if src=0 and srclen<>0 then exit(r0=0)
      [struct+60h]=00000000h                ;\
      SHA1_Init(struct)                     ; first compute normal SHA1
      SHA1_Update(struct,src,srclen)        ; (same as SHA1_Init_Update_Finish)
      SHA1_Finish(first_sha1,struct)        ;/
     @@lop1:
      i=13h  ;start with LSB of big-endian 20-byte value  ;\increment SHA1 value
     @@lop2:                                              ; by one (with somewhat
      [first_sha1+i]=[first_sha1+i]+1, i=i-1              ; uncommon/bugged carry-
      if i>=0 and [first_sha1+i+1]=01h then goto @@lop2   ;/out to higher bytes)
      SHA1_Update(struct,first_sha1,14h)    ;\compute 2nd SHA1 across 1st SHA1,
      SHA1_Finish(second_sha1,struct)       ;/done without re-initializing struct
      for i=0 to min(14h,dstlen)-1, [dst]=[second_sha1+i], dst=dst+1
      dstlen=dstlen-min(14h,dstlen)
      if dstlen<>0 then goto @@lop1 else exit(r0=1)

SHA1_Init_Update_Finish_HMAC(dst,key,src,srclen)

      if len(key)>40h then key=SHA1(key) ;convert LONG keys to 14h-bytes length
      if len(key)<40h then zero-pad key to 40h-bytes length
      for i=0 to 3Fh, [inner_key+i]=[key+i] xor 36h ;\
      [struct+60h]=00000000h                        ;
      SHA1_Init(struct)                             ; compute 1st SHA1
      SHA1_Update(struct,inner_key,40h)             ; across inner key and data
      SHA1_Update(struct,src,srclen)                ;
      SHA1_Finish(first_sha1,struct)                ;/
      for i=0 to 3Fh, [outer_key+i]=[key+i] xor 5Ch ;\
      [struct+60h]=00000000h                        ;
      SHA1_Init(struct)                             ; compute final SHA1
      SHA1_Update(struct,outer_key,40h)             ; across outer key and 1st SHA1
      SHA1_Update(struct,first_sha1,14h)            ;
      SHA1_Finish(dst,struct)                       ;/

SWI 28h (DSi9/DSi7) - SHA1_Compare_20_Bytes(src1,src2)
Out: r0=1=match, r0=0=mismatch/error (error occurs if src1=0 or src2=0).

BIOS RSA Functions (DSi only)

RSA_Init_crypto_heap(heap_nfo,heap_start,heap_size)
RSA_Decrypt(heap_nfo,struct,dest4)
RSA_Decrypt_Unpad(heap_nfo,dst,src,key)
RSA_Decrypt_Unpad_OpenPGP_SHA1(heap_nfo,dst,src,key)
RSA is important because the DSi cartridge header and system files do contain RSA signatures. Which makes it impossible to create unlicensed software (without knowing Nintendo's private key).
BIOS RSA Basics
BIOS RSA Pseudo Code
SWI 20h (DSi9/DSi7) - RSA_Init_crypto_heap(heap_nfo,heap_start,heap_size)
Initializes the heap for use with SWI 21h..23h. heap_nfo is a 0Ch-byte structure, which gets set to:

      [heap_nfo+0] = heap_start (rounded-up to 4-byte boundary)
      [heap_nfo+4] = heap_end   (start+size, rounded-down to 4-byte boundary)
      [heap_nfo+8] = heap_size  (matched to above rounded values)

heap_start should point to a free memory block which will be used as heap, heap_size should be usually 1000h.
SWI 21h (DSi9/DSi7) - RSA_Decrypt(heap_nfo,ptr_nfo,len_dest)

      [ptr_nfo+0] = dst (usually 7Fh bytes, max 80h bytes)
      [ptr_nfo+4] = src (80h bytes)
      [ptr_nfo+8] = key (80h bytes)

This is a subfunction for SWI 22h/23h. It's returning raw decrypted data without unpadding (aside from stripping leading 00h bytes; most (or all) signatures are containing one leading 00h byte, so the returned [len_dest] value will be usually 7Fh).
Return value (r0) is: 0=failed, 1=okay. The length of the decrypted data is returned at [len_dest].
SWI 22h (DSi9/DSi7) - RSA_Decrypt_Unpad(heap_nfo,dst,src,key)
Same as SWI 21h, and additionally removes the "01h,min eight FFh,00h" padding. src,dst,key should be 80h-bytes. The output at dst can be theoretically max 80h-bytes (or shorter due to removed padding). In practice, the DSi is often using only the first 14h-bytes at dst (aka the last 14h-bytes from src) as SHA1 or SHA1-HMAC value (RSA-SHA1). Return value (r0) is: 0=failed, 1=okay.
SWI 23h (DSi9/DSi7) - RSA_Decrypt_Unpad_OpenPGP_SHA1(heap_nfo,dst,src,key)
Same as SWI 22h, but with some extra processing for extracting a SHA1 value from an OpenPGP header: The data must consist of five ASN.1 (DER) chunks (with Tag IDs 30h,30h,06h,05h,04h), the last chunk (with ID=04h) must be 14h bytes in size, and the 14h-byte chunk data is then copied to dst. The other four chunks must exist, but their content is just skipped.

      00h 1    Leading zero       (00h)                           ;\
      01h 1    Block type         (01h)                           ; padding
      02h 5Ah  Padding Bytes      (FFh-filled)                    ;
      5Ch 1    Padding End        (00h)                           ;/
      5Dh 2    30h,junk(1)        (30h,21h)                       ;-sequence
      5Fh 2    30h,junk(1)        (30h,09h)                       ;-sequence
      61h 7    06h,len,junk(len)  (06h,05h, 2Bh,0Eh,03h,02h,1Ah)  ;-OID for SHA1
      68h 2    05h,junk(1)        (05h,00h)                       ;-null
      6Ah 16h  04h,len,sha1(len)  (04h,14h, sha1[14h bytes])      ;-SHA1

The "junk" bytes aren't actually used/verified by the DSi. Handling chunks with len>7Fh looks quite weird/bugged. The DSi firmware contains some functions where it could optionally use SWI 22h or SWI 23h for RSA signatures (although, there aren't any known cases where it would actually use SWI 23h). Note: The DSi's Flipnote ".ppm" files are using the SWI 23h style SHA1 format (but Flipnote contains it's own RSA functions instead of using the BIOS SWI functions). DS Download Play (and equivalent code in NDS Firmware) is SWI 23h style, too (but also uses its own RSA function instead of the BIOS SWI).
Note: The format is based on the OpenPGP Message Format (RFC 4880), that format allows to use similar headers for MD5, SHA256, etc. (the DSi supports only SHA1 though).
Unencrypted Signatures
Emulators can hook the RSA BIOS functions to copy unencrypted signatures as-is (instead of trying to decrypt them). That allows to create "authentic" files that are fully compatible with the DSi firmware, and which would be actually working on real hardware (when knowing the private key).
Unencrypted 80h-byte signatures should be stored in following format (as defined in RFC 2313):

      00h   1      "00" Leading zero (00h)
      01h   1      "BT" Block type (always 01h on DSi)
      02h   8+n    "PS" Padding (FFh-filled, min 8 bytes, usually 69h bytes on DSi)
      0Ah+n 1      "00" Padding end (00h)
      0Bh+n 75h-n  "D"  Data (max 75h bytes, usually a 14h-byte SHA1 value on DSi)

If the hooked BIOS function sees a RSA source to contain "00h, 01h, at least eight FFh, followed by 00h", then it could treat it as unencrypted data (it's nearly impossible that an encrypted signature could contain those values).
Key.Bit0
The DSi BIOS contains two different RSA core modes (either one of them is used, depending on whether BIT0 of the FIRST BYTE of the "key" is set or cleared). The purpose & difference between those two modes is unknown. Also, dunno if that BIT0 thing is something common in the RSA world?
DSi Public RSA Keys (for verifying signatures)

      TWL_FIRM       (F1,F5,1A,FF..) eMMC Boot Info (same key for retail+debug)
      BIOS:FFFF87F4h (C3,02,93,DE..) Key0: System Menu (Launcher) of Retail version
      BIOS:FFFF8874h (B6,18,D8,61..) Key1: System Fun Tools and Wifi Firmware
      BIOS:FFFF88F4h (DA,94,09,01..) Key2: System Base Tools (Settings, Shop)
      BIOS:FFFF8974h (95,6F,79,0D..) Key3: DSiWare and DSi ROM Cartridges
      BIOS:FFFF89F4h (D4,30,E3,7D..) Key4: Unknown ;\probably more/unused RSA keys
      BIOS:FFFF8A74h (BD,29,02,38..) Key5: Unknown ; (DSi only)
      BIOS:FFFF8AF4h (CF,8A,4B,15..) Key6: Unknown ; (doesn't exist on 3DS)
      BIOS:FFFF8B74h (A3,BC,C1,7C..) Key7: Unknown ;/
      BIOS:FFFF9920h (30,33,26,D5..) Unknown (probably NOT a RSA key)
      Launcher       (BA,F1,98,A4..) HWINFO_S.dat (with RSA-SHA1-HMAC)
      Launcher       (9F,80,BC,5F..) Version Data and TWLFontTable.dat
      Launcher       (C7,F4,1D,27..) DS Cart Whitelist (missing RSA in v1.4E)
      Launcher+NDS   (9E,C1,CC,C0..) For wifi-booted NDS titles (DsDownloadPlay)
      Flipnote       (C2,3C,BC,13..) Public key for Flipnote .ppm files
      Unknown        (?)             HWID.sgn
      Unknown        (?)             Newer NDS ROM Cartridges (have RSA, too?)
      DSi Shop       (9D,69,36,28..) Unknown, seems to be RSA        (100h bytes)
      Launcher       (F8,24,6C,58..) Root key for cert.sys CA00000001(200h bytes)
      cert.sys       (B2,79,C9,E2..) CA00000001 key for cert.sys keys(100h bytes)
      cert.sys       (93,BC,0D,1F..) CP00000007 key for tmd's        (100h bytes)
      cert.sys       (AD,07,A9,37..) XS00000003 key for shop-tickets (100h bytes)
      cert.sys       (92,FF,96,40..) XS00000006 key for free-tickets (100h bytes)
      cert.sys       (01,93,6D,08..) MS00000008 key for dev.kp       (ECC, non-RSA)
      dev.kp         (per-console)   TWxxxxxxxx... key for tad files (ECC, non-RSA)
      *.bin          (random?)       AP00030015484e42gg in tad files (ECC, non-RSA)
      Launcher+Boot  (BC,FD,A1,FF..) Debug0: System Menu (Launcher, Debug version)
      Launcher       (E9,9E,A7,9F..) Debug1:
      Launcher       (A7,9F,54,A0..) Debug2:
      Launcher       (AC,93,BB,3C..) Debug3: Public key for Debug DSiware/ROMs
      Debug Updater  (E5,1C,BF,C7..) Debug Public key for HWInfo
      Debug Updater  (C8,4B,38,2C..) Debug Public key for HWID.sgn    (100h bytes)
      Launcher       (D0,1F,E1,00..) Debug Root key for CA00000002 key(200h bytes)
      debug cert.sys (...)           Debug CA00000002 key for cert.sys(100h bytes)
      debug cert.sys (...)           Debug CP00000005 key for ...?    (100h bytes)
      debug cert.sys (...)           Debug CP00000007 key for ...     (100h bytes)
      debug cert.sys (...)           Debug XS00000006 key for ...     (100h bytes)
      verdata        (...)           Public keys in Version Data file?
      Unknown        (?)             further keys...?

DSi Private RSA Keys (for creating signatures)
Nintendo's private keys should be known only by Nintendo. However, the console does have a few "own" private keys (for sending signed data to Nintendo (verdata), for storing signed data on SD card (flipnote), plus some more keys for the developer's debug version).

      Flipnote       (26,A7,53,7E..) Private key for Flipnote .ppm files
      dev.kp         (per-console)   TWxxxxxxxx... key for tad files (ECC, non-RSA)
      (temp/unsaved?)(random?)       AP00030015484e42gg    tad files (ECC, non-RSA)
      verdata        (...)           Private keys in Version Data file?
      Debug Updater  (77,FC,77,9E..) Private key for Debug HWID.sgn (100h bytes)
      Debug Updater  (B5,7C,C2,85..) Private key for Debug HWInfo
      Debug SDK      (95,DC,C8,18..) Private key for Debug DSiware/ROMs (Debug3)
      Unknown        (?)             further keys...?

The private keys are usually stored in DER format; that's including entries for the public key/exponent, and the original prime numbers that the key was generated from, plus some numbers that were temporarily used during key creation, and with all entries preceeded by tag/length values, whereas values with MSB set are preceeded by a 00h byte to make them "unsigned" (eg. most 80h-byte keys will occupy 81h bytes in DER format).

BIOS RSA Basics

RSA Basics
The RSA formulas are quite simple: Applying an exponent and modulus to the source data. There are two formulas used for encryption/decryption. The first formula requires only the Public Key (and an exponent, which is usually some fixed constant; on the DSi it's always 10001h aka 65537 decimal). The second formula is almost same, but requires the Private Key instead of the constant exponent (and also requires the Public Key as modulus):

      Public Key formula:      dest = src^10001h mod pubkey
      Private Key formula:     dest = src^prvkey mod pubkey

That formulas can be used for encrypting secret messages, as so:

      Recipient's Public Key   --> Encrypt a message
      Recipient's Private Key  --> Decrypt a message

Or, using the formulas the other way around, to create digital signatures:

      Sender's Private Key     --> Encrypt/create a signature
      Sender's Public Key      --> Decrypt/verify a signature

The overall idea is that only the owner of the Private Key can decrypt messages, or create signatures. The Public Key can be shared freely, so that everybody can encrypt messages, or verify signatures.
RSA Big Number Maths
The exponent/modulus can be implemented with simple unsigned multiply/divide operations. However, RSA requires dealing with big 1024bit integers (or even bigger numbers when using larger keys), this does usually require some software functions since regular CPUs cannot directly deal with such large numbers.
RSA Byte Order
The DSi is storing all RSA keys and signatures in Big-Endian format, so one will need to reverse the byte order before doing the actual maths on Little-Endian CPUs.
RSA Signatures (used on DSi)
Digital signatures can be used for signing documents or other binaries. The signature does usually consist of a secure checksum (SHA-1, MD5, SHA256, etc.) computed on the document/binary, and then encrypted via the RSA Private Key formula.
The checksum can be then decrypted via Public Key, if the decrypted checksum does match up, then one can be sure that the document/binary hasn't been modified, and that it was really created by the Private Key owner.
RSA Encrypted Messages (not used on DSi)
Encrypted RSA messages are restricted to the size of the Public Key (eg. with a 1024bit key, the message should be smaller than 128 bytes). For bigger messages, one could either split the message into smaller snippets, or, one could combine RSA with some other encryption mechanism (eg. store an AES key in the RSA message, and decrypt the actual document via AES; that would add private/public key security to AES).
RSA Padding
RSA can be weak if the message is a small number (especially very small values like "0" or "1" obviously wouldn't work well with the "msg^exp" maths; other small values can be also weak, eg. with the common/small public exponent 10001h). To avoid that problem, the MSBs of the message should be padded with nonzero bytes, typically as so (as defined in RFC 2313):

      00h   1      "00" Leading zero (00h)
      01h   1      "BT" Block type (always 01h on DSi)
      02h   8+n    "PS" Padding (FFh-filled, min 8 bytes, usually 69h bytes on DSi)
      0Ah+n 1      "00" Padding end (00h)
      0Bh+n 75h-n  "D"  Data (max 75h bytes, usually a 14h-byte SHA1 value on DSi)

That, for 80h-byte messages. For other sizes replace "75h" by "F5h, 1F5h, etc."
RSA Key Generation
Generating a RSA key pair is more difficult than the encryption/decryption part. First of, one needs two unsigned random prime numbers; for a 1024bit key, that would be usually two large 512bit prime numbers (whereas, finding real prime numbers is complicated, and it's more common to use values that have a "high probability" of being prime numbers).
The public key is then simply generated by multiplying the two prime numbers (P and Q) with each other:

      pubkey = P * Q

The private key is also based on the same prime numbers, but the maths there are more complicated (and not described here).
When knowing one prime number, one could theoretically compute the other as "Q=pubkey/P", however, prime numbers aren't as rare as one might think, and it's quite impossible to guess (or brute-force) one of the prime numbers.

BIOS RSA Pseudo Code

rsa_mpi_pow_mod(dst,src,pubkey,exp,num_exp_bits) ;[dst]=[src]^[exp] mod [key]

      base(rsa__number_size), bigbuf(rsa_number_size*2)
      [base]=[src], [dst]=1, pow8bit=01h                ;-init base, result, powbit
      for i=1 to num_exp_bits
        if [exp] AND pow8bit then rsa_mpi_mul_mod(dst,base)   ;-mul result
        rsa_mpi_mul_mod(base,base)                            ;-square base
        pow8bit=pow8bit ROL 1, exp=exp+carry                  ;-next exp bit
      next i
      return

This is the RSA main function. The exponent is applied by squaring the "src" several times, and, if the corresponding exponent bit is set, multiplying the result by the squared value. To avoid the numbers to become incredible large, the modulus is applied after each multiplication (rather than applying it only on the final result).

      For the Private Key formula: Use exp=prvkey, num_exp_bits=rsa_number_size*8
      For the Public Key formula:  Use exp=ptr_to_10001h, num_exp_bits=17

The parameters and result for "rsa_mpi_pow_mod" must be in little-endian. Ie. for DSi, reverse the byte order of the incoming/outgoing values. And, on DSi, use rsa_number_size=80h (aka 128 bytes, aka for 1024bit RSA).
rsa_mpi_mul_mod(dst,src):

      rsa_mpi_mul(bigbuf,dst,src)           ;-multiply
      rsa_mpi_mod(bigbuf,pubkey)            ;-modulus
      [dst]=[bigbuf+0..rsa_number_size-1]   ;-copy to dst
      return

rsa_mpi_mul(dst,src1,src2): ;[dst]=[src1]*[src2]

      [dst+0]=0, oldmsw=0                   ;-init first word and oldmsw
      for i=0 to rsa_number_size-4 step 4   ;\
        call @@inner_loop                   ; compute LSWs of destination
        src2=src2+4                         ;
      next i                                ;/
      src2=src2-4
      for i=rsa_number_size-8 to 0 step -4  ;\
        src1=src1+4                         ; compute MSWs of destination
        call @@inner_loop                   ;
      next i                                ;/
      return
     ;---
     @@inner_loop:
      [dst+4]=oldmsw, oldmsw=0
      for j=0 to i step 4
        msw:lsw = [src1+j]*[src2-j]
        [dst+0]=[dst+0]+lsw
        [dst+4]=[dst+4]+msw+cy
        oldmsw=oldmsw+cy
      next j
      dst=dst+4
      ret

rsa_mpi_mod(dst,src): ;[dst]=[dst] mod [src] ;aka division remainder
;Double/Single -> Single modulo division (mpi/mpi)
;Divisor's MSW must be >= 80000000h

      ebx=rsa_number_size, dst=dst+ebx, i=ebx+4
     @@type0_lop:                                                           ;\
      if [dst+ebx-4]=0 then goto @@type0_next                               ;
      rsa_mpi_cmp(dst,src), if borrow then goto @@type1_next                ; type0
      rsa_mpi_sub(dst,src), if [dst+ebx-4]<>0 then goto @@type1_next        ; loop
     @@type0_next:                                                          ;
      dst=dst-4, i=i-4, if i>0 then goto @@type0_lop                        ;/
      goto @@done
     ;--- --- ---
     @@type1_lop:                                                           ;\
      lsw=[dst+ebx-4], msw=[dst+ebx-0]                                      ;
      if msw>=[src+ebx-4] then fac=FFFFFFFFh else fac=msw:lsw / [src+ebx-4] ;
      rsa_mpi_mulsub(dst,src,fac), if carry=0 then goto @@skip_add          ; type1
     @@add_more:                                                            ; loop
      rsa_mpi_add(dst,src)                                                  ;
      [dst+ebx]=[dst+ebx]+carry, if carry=0 then goto @@add_more            ;
     @@skip_add:                                                            ;
      if [dst+ebx-4]=0 then goto @@type0_next                               ;
     @@type1_next:                                                          ;
      dst=dst-4, i=i-4, if i>0 then goto @@type1_lop                        ;/
     @@done:
      return

rsa_mpi_mulsub(dst,src,fac): ;[dst]=[dst]-[src]*fac

      oldborrow=0, oldmsw=0                                       ;\
      for i=0 to rsa_number_size-4 step 4                         ; process
        msw:lsw = [src+i]*fac, lsw=lsw+oldmsw, oldmsw=msw+carry   ; rsa_number_size
        [dst+i]=[dst+i]-lsw-oldborrow, oldborrow=borrow           ; bytes, plus...
      next i                                                      ;/
      [dst+rsa_number_size]=[dst+rsa_number_size]-oldmsw-oldborrow ;-one extra word
      return borrow   ;(unlike "rsa_embedded" which returns INVERTED borrow)

rsa_mpi_add(dst,src): ;out: [dst]=[dst]+[src], carry

      carry = 0
      for i=0 to rsa_number_size-4 step 4
        [dst+i]=[dst+i]+[src+i]+carry
      next i
      return carry

rsa_mpi_sub(dst,src): ;out: [dst]=[dst]-[src], borrow/unused

      borrow = 0
      for i=0 to rsa_number_size-4 step 4
        [dst+i]=[dst+i]-[src+i]-borrow
      next i
      return borrow

rsa_mpi_cmp[dst,src]: ;compare [dst]-[src], out: borrow

      for i=rsa_number_size-4 to 0 step -4
        temp=[dst+i]-[src+i], if not equal then return borrow
      next i
      return borrow

This is about same as "sub", but faster (because it can abort the loop upon first difference).

BIOS 3DS Exception Vectors

Exception Vectors
The 3DS bootroms do mostly contain bootcode, unlike GBA/NDS without any public functions, apart from some small stubs for redirecting the exception vectors to RAM locations:

      08000000h 8  arm9_irq                ldr r15,[$+4] // dd vector  ;\
      08000008h 8  arm9_fiq                ldr r15,[$+4] // dd vector  ;
      08000010h 8  arm9_svc                ldr r15,[$+4] // dd vector  ; ARM9
      08000018h 8  arm9_undef              ldr r15,[$+4] // dd vector  ; exceptions
      08000020h 8  arm9_prefetch_abort     ldr r15,[$+4] // dd vector  ;
      08000028h 8  arm9_data_abort         ldr r15,[$+4] // dd vector  ;/
      1FFFFFA0h 8  arm11_irq               ldr r15,[$+4] // dd vector  ;\
      1FFFFFA8h 8  arm11_fiq               ldr r15,[$+4] // dd vector  ;
      1FFFFFB0h 8  arm11_svc               ldr r15,[$+4] // dd vector  ; ARM11
      1FFFFFB8h 8  arm11_undef             ldr r15,[$+4] // dd vector  ; exceptions
      1FFFFFC0h 8  arm11_prefetch_abort    ldr r15,[$+4] // dd vector  ;
      1FFFFFC8h 8  arm11_data_abort        ldr r15,[$+4] // dd vector  ;/
      1FFFFFDCh 4  arm11_core1_entrypoint  dd vector                   ;-CPU1 entry
      (OVERLAY) 4  arm11_core23_entry      dd vector                   ;-CPU2/3

The ARM11 exception vectors are shared for all CPU cores (so one must manually redirect them to core specific handlers).
Alternately, instead of using the above RAM vectors, one could use ARM11 virtual memory or ARM9 ITCM for custom vectors.
Moreover, the CFG11_BOOTROM_OVERLAY_CNT/VAL feature allows to redirect ARM11 vectors on New3DS (mainly intended for booting CPU2/CPU3 cores).
SWI/SVC Functions
There aren't any built-in functions in the bootroms, however, SVC opcodes can be used to obtain entrypoints to OS functions. That is, once when the OS is booted (FIRM files are started without any OS functions, but .code files can use OS functions).
Note: ARM has renamed SWI opcodes to SVC opcodes.

BIOS RAM Usage

Below contains info about RAM contents at cartridge boot time (as initialized by the BIOS/Firmware), plus info about RAM locations used by IRQ handlers and SWI functions.
GBA BIOS RAM Usage
Below memory at 3007Fxxh is often accessed directly, or via mirrors at 3FFFFxxh.

      3000000h 7F00h User Memory and User Stack              (sp_usr=3007F00h)
      3007F00h A0h   Default Interrupt Stack (6 words/time)  (sp_irq=3007FA0h)
      3007FA0h 40h   Default Supervisor Stack (4 words/time) (sp_svc=3007FE0h)
      3007FE0h 10h   Debug Exception Stack (4 words/time)    (sp_xxx=3007FF0h)
      3007FF0h 4     Pointer to Sound Buffer (for SWI Sound functions)
      3007FF4h 3     Reserved (unused)
      3007FF7h 1     Reserved (intro/nintendo logo related)
      3007FF8h 2     IRQ IF Check Flags (for SWI IntrWait/VBlankIntrWait functions)
      3007FFAh 1     Soft Reset Re-entry Flag (for SWI SoftReset function)
      3007FFBh 1     Reserved (intro/multiboot slave related)
      3007FFCh 4     Pointer to user IRQ handler (to 32bit ARM code)

NDS BIOS RAM Usage
Below memory at 27FFxxxh is mirrored to 23FFxxxh (on retail consoles with 4MB RAM), however, it should be accessed via address 27FFxxxh (for compatibility with debug consoles with 8MB RAM). Accessing it via mirrors at 2FFFxxxh is also valid (this is done by DSi enhanced games; even when running in non-DSi mode; this allows DSi games to use the same memory addresses in NDS and DSi mode).

      2000000h ...   ARM7 and ARM9 bootcode can be loaded here (2000000h..23BFDFFh)
      2400000h ...   Debug bootcode can be loaded here (2400000h..27BFDFFh)
      23FEE00h 168h  Fragments of NDS9 firmware boot code
      27FF800h 4     NDS Gamecart Chip ID 1
      27FF804h 4     NDS Gamecart Chip ID 2
      27FF808h 2     NDS Cart Header CRC (verified)            ;hdr[15Eh]
      27FF80Ah 2     NDS Cart Secure Area CRC (not verified ?) ;hdr[06Ch]
      27FF80Ch 2     NDS Cart Missing/Bad CRC (0=Okay, 1=Missing/Bad)
      27FF80Eh 2     NDS Cart Secure Area Bad (0=Okay, 1=Bad)
      27FF810h 2     Boot handler task number (usually FFFFh at cart boot time)
      27FF812h 2     Secure disable (0=Normal, 1=Disable; Cart[078h]=BIOS[1088h])
      27FF814h 2     SIO Debug Connection Exists (0=No, 1=Yes)
      27FF816h 2     RTC Status?                 (0=Okay, 1=Bad)
      27FF818h 1     Random RTC    ;random LSB from SIO debug detect handshake
      27FF819h 37h   Zerofilled by firmware
      27FF850h 2     NDS7 BIOS CRC (5835h)
      27FF860h 4     Somewhat copy of Cart[038h], nds7 ram addr (?)
      27FF864h 4     Wifi FLASH User Settings Bad (0=Okay, 1=Bad)
      27FF868h 4     Wifi FLASH User Settings FLASH Address (fmw[20h]*8)
                       maybe recommended to use above RAM cell instead FLASH entry?
      27FF86Ch 4     Whatever (seems to be zero at cart boot time)
      27FF870h 4     Whatever (seems to be zero at cart boot time)
      27FF874h 2     Wifi FLASH firmware part5 crc16 (359Ah) (fmw[026h])
      27FF876h 2     Wifi FLASH firmware part3/part4 crc16 (fmw[004h] or ZERO)
                       Above is usually ZERO at cart boot (set to fmw[004h] only
                       when running pictochat, or maybe also when changing user
                       settings)
      27FF878h 08h   Not used
      27FF880h 4     Message from NDS9 to NDS7  (=7 at cart boot time)
      27FF884h 4     NDS7 Boot Task (also checked by NDS9) (=6 at cart boot time)
      27FF888h ..    Whatever (seems to be zero at cart boot time)
      27FF890h 4     Somewhat boot flags (somewhat B0002A22h)
                       bit10 part3/part4 loaded/decoded (bit3 set if bad crc)
                       bit28 part5 loaded/decoded with good crc
      27FF894h 36Ch  Not used (zero)
      27FFC00h 4     NDS Gamecart Chip ID 1   (copy of 27FF800h)
      27FFC04h 4     NDS Gamecart Chip ID 2   (copy of 27FF804h)
      27FFC08h 2     NDS Cart Header CRC      (copy of 27FF808h)
      27FFC0Ah 2     NDS Cart Secure Area CRC (copy of 27FF80Ah)
      27FFC0Ch 2     NDS Cart Missing/Bad CRC (copy of 27FF80Ch)
      27FFC0Eh 2     NDS Cart Secure Area Bad (copy of 27FF80Eh)
      27FFC10h 2     NDS7 BIOS CRC (5835h)    (copy of <27FF850h>)
      27FFC12h 2     Secure Disable           (copy of 27FF812h)
      27FFC14h 2     SIO Debug Exist          (copy of 27FF814h)
      27FFC16h 1     RTC Status?              (<8bit> copy of 27FF816h)
      27FFC17h 1     Random 8bit              (copy of <27FF818h>)
      27FFC18h 18h   Not used (zero)
      27FFC30h 2     GBA Cartridge Header[BEh], Reserved
      27FFC32h 3     GBA Cartridge Header[B5h..B7h], Reserved
      27FFC35h 1     Whatever flags ?
      27FFC36h 2     GBA Cartridge Header[B0h], Maker Code
      27FFC38h 4     GBA Cartridge Header[ACh], Gamecode
      27FFC3Ch 4     Frame Counter (eg. 00000332h in no$gba with original firmware)
      27FFC40h 2     Boot Indicator (0001h=normal; required for some NDS games)
      27FFC42h 3Eh   Not used (zero)
      27FFC80h 70h   Wifi FLASH User Settings (fmw[newest_user_settings])
      27FFCF0h 10h   Not used (zero)
      27FFDxxh ..    NDS9 Debug Exception Stack (stacktop=27FFD9Ch)
      27FFD9Ch 4     NDS9 Debug Exception Vector (0=None)
      27FFDA0h ..    ...
      27FFE00h 170h  NDS Cart Header at 27FFE00h+0..16Fh
      27FFF70h ..    Not used (zerofilled at cart boot time)
      27FFFF8h 2     NDS9 Scratch addr for SWI IsDebugger check
      27FFFFAh 2     NDS7 Scratch addr for SWI IsDebugger check
      27FFFFCh ..    ...
      27FFFFEh 2     Main Memory Control (on-chip power-down I/O port)
      DTCM+3FF8h 4   NDS9 IRQ IF Check Bits (hardcoded RAM address)
      DTCM+3FFCh 4   NDS9 IRQ Handler (hardcoded RAM address)
      37F8000h FE00h ARM7 bootcode can be loaded here (37F8000h..3807DFFh)
      380F700h 1D4h  Fragments of NDS7 firmware boot code
      380F980h 4     Unknown/garbage (set to FBDD37BBh, purpose unknown)
                       NOTE: Cooking Coach is doing similar crap at 37FCF1Ch ?!?!
      380FFC0h 4     DSi7 IRQ IF2 Check Bits (hardcoded RAM address) (DSi only)
      380FFDCh ..    NDS7 Debug Stacktop / Debug Vector (0=None)
      380FFF8h 4     NDS7 IRQ IF Check Bits (hardcoded RAM address)
      380FFFCh 4     NDS7 IRQ Handler (hardcoded RAM address)
      ---
      summary of nds memory used at cartridge boot time:
      (all other memory zero-filled unless containing cartridge data)
      37F8000h..3807E00h  ;cartridge area (nds7 only)
      2000000h..23BFE00h  ;cartridge area (nds9 and nds7)
      2400000h..27BFE00h  ;cartridge area (debug ver)
      23FEE00h..23FEF68h  ;fragments of NDS9 firmware boot code
      27FF800h..27FF85Fh  ;various values (from BIOS boot code)
      27FF860h..27FF893h  ;various values (from Firmware boot code)
      27FFC00h..27FFC41h  ;various values (from Firmware boot code)
      27FFC80h..27FFCE6h  ;firmware user settings
      27FFE00h..27FFF6Fh  ;cart header
      380F700h..380F8D4h  ;fragments of NDS7 firmware boot code
      380F980h            ;set to FBDD37BBh
      ---
      register settings at cartridge boot time:
      nds9 r0..r11     = zero
      nds9 r12,r14,r15 = entrypoint
      nds9 r13         = 3002F7Ch (!)
      nds9 r13_irq     = 3003F80h
      nds9 r13_svc     = 3003FC0h
      nds9 r14/spsr_irq= zero
      nds9 r14/spsr_svc= zero
      ---
      nds7 r0..r11     = zero
      nds7 r12,r14,r15 = entrypoint
      nds7 r13         = 380FD80h
      nds7 r13_irq     = 380FF80h
      nds7 r13_svc     = 380FFC0h
      nds7 r14/spsr_irq= zero
      nds7 r14/spsr_svc= zero
      ---
      Observe that SWI SoftReset applies different stack pointers:
      Host  sp_svc    sp_irq    sp_sys    zerofilled area       return address
      NDS7  380FFDCh  380FFB0h  380FF00h  [380FE00h..380FFFFh]  Addr[27FFE34h]
      NDS9  0803FC0h  0803FA0h  0803EC0h  [DTCM+3E00h..3FFFh]   Addr[27FFE24h]

DSi BIOS RAM

      2000000h 8     AutoParam Old Title ID (former title)    ;carthdr[230h]
      2000008h 1     AutoParam Unknown/Unused
      2000009h 1     AutoParam Flags (03h=Stuff is used?)
      200000Ah 2     AutoParam Old Maker code                 ;carthdr[010h]
      200000Ch 2     AutoParam Unknown (02ECh) ;\counter/length/indices/whatever?
      200000Eh 2     AutoParam Unknown (0000h) ;/
      2000010h 2     AutoParam CRC16 on [000h..2FFh], initial=FFFFh, [010h]=0000h
      2000012h 2     AutoParam Unknown/Unused (000Fh = want Internet Settings?)
      2000014h 2ECh  AutoParam Unknown... some buffer... string maybe?
      2000300h 4     AutoLoad ID ("TLNC") (also requires BPTWL[70h]=01h)
      2000304h 1     AutoLoad Unknown/unused (usually 01h)
      2000305h 1     AutoLoad Leng of data at 2000308h (01h..18h,for CRC,18h=norm)
      2000306h 2     AutoLoad CRC16 of data at 2000308h (with initial value FFFFh)
      2000308h 8     AutoLoad Old Title ID (former title) (can be 0=anonymous)
      2000310h 8     AutoLoad New Title ID (new title to be started, 0=none)
      2000318h 4     AutoLoad Flags (bit0,1-3,4,5,6,7) ;usually 16bit, once 32bit
      200031Ch 4     AutoLoad Unused (but within checksummed area when CRC len=18h)
      2000320h E0h   AutoLoad Unused (but zerofilled upon erasing autoload area)
      2000400h 128h  System Settings from TWLCFGn.dat file (bytes 088h..1AFh)
      20005E0h 1     WlFirm Type (1=DWM-W015, 2=DWM-W024) (as wifi_flash[1FDh])
      20005E1h 1     WlFirm Unknown (zero)
      20005E2h 2     WlFirm CRC16 with initial value FFFFh on [20005E4h..20005EFh]
      20005E4h 4     WlFirm RAM vars (500400h)  ;\
      20005E8h 4     WlFirm RAM base (500000h)  ; as from "Wifi Firmware" file
      20005ECh 4     WlFirm RAM size (02E000h)  ;/
      20005F0h 10h   WlFirm Unknown (zero)
      2000600h 14h   Hexvalues from HWINFO_N.dat
      2000800h ...   Unlaunch Auto-load feature (via "device:/Path/Filename.ext")
      23FEE00h 200h  DSi9 bootstrap relict
      ---
      2FEE120h 4     "nand"   <--- passed as so to launcher
      2FF80xxh
      2FF82xxh
      2FF83xxh
      2FF89xxh
      2FF8Axxh
      2FF8Bxxh
      2FF8Cxxh
      2FF8Dxxh       ... Wifi MAC address, channel mask, etc.
      2FF8Fxxh
      2FF90xxh
      2FF91xxh
      2FF9208h       FBDD37BBh (that odd "garbage" value occurs also on NDS)
      2FFA1xxh
      2FFA2xxh
      2FFA5xxh
      2FFA6xxh
      2FFA680h 12    02FD4D80h,00000000h,00001980h
      2FFA68Ch ..    Zerofilled
      ---
      2FFC000h 1000h Full Cart Header (as at 2FFE000h, but, FOR NDS ROM CARTRIDGE)
      2FFD000h 7B0h  Zerofilled
      2FFD7B0h 8+1   Version Data Filename (eg. 30,30,30,30,30,30,30,34,00)
      2FFD7B9h 1     Version Data Region   (eg. 50h="P"=Europe)
      2FFD7BAh 1     Unknown  (00)   ;bit0 = warmboot-flag-related
      2FFD7BBh 1     Unknown  (00)
      2FFD7BCh 15+1  eMMC CID (dd,ss,ss,ss,ss,03,4D,30,30,46,50,41,00,00,15), 00
      2FFD7CCh 15+1  eMMC CSD (40,40,96,E9,7F,DB,F6,DF,01,59,0F,2A,01,26,90), 00
      2FFD7DCh 4     eMMC OCR (80,80,FF,80)                                  ;20h
      2FFD7E0h 8     eMMC SCR (00,04,00,00,00,00,00,00) (for MMC: dummy/4bit);24h
      2FFD7E8h 2     eMMC RCA (01,00)                                        ;2Ch
      2FFD7EAh 2     eMMC Typ (01,00) (0=SD Card, 1=MMC Card)                ;2Eh
      2FFD7ECh 2     eMMC HCS (00,00) ;copy of OCR.bit30 (sector addressing) ;30h
      2FFD7EEh 2     eMMC ?   (00,00)                                        ;32h
      2FFD7F0h 4     eMMC ?   (00,00,00,00)                                  ;34h
      2FFD7F4h 4     eMMC CSR (00,09,00,00)   ;card status (state=tran)      ;38h
      2FFD7F8h 2     eMMC Port 4004824h setting  (00,01)  ;SD_CARD_CLK_CTL   ;3Ch
      2FFD7FAh 2     eMMC Port 4004828h setting  (E0,40)  ;SD_CARD_OPTION    ;3Eh
      2FFD7FCh 2     eMMC ?   (00,00)                                        ;40h
      2FFD7FEh 2     eMMC Device (usually 0001h=eMMC) (0000h=SD/MMC Slot?)   ;42h
      2FFD800h 1     Titles: Number of titles in below lists (max 76h)
      2FFD801h 0Fh   Titles: Zerofilled
      2FFD810h 10h   Titles: Pub Flags (1bit each) ;same maker plus public.sav
      2FFD820h 10h   Titles: Prv Flags (1bit each) ;same maker plus private.sav
      2FFD830h 10h   Titles: Jmp Flags (1bit each) ;jumpable or current-title
      2FFD840h 10h   Titles: Mkr Flags (1bit each) ;same maker
      2FFD850h 3B0h  Titles: Title IDs (8 bytes each)
      2FFDC00h 400h  Zerofilled
      2FFE000h 1000h DSi Full Cart Header (additionally to short headers)
      2FFF000h 0Ch   Zerofilled
      2FFF00Ch 4     ? 0000007Fh
      2FFF010h 4     ? 550E25B8h
      2FFF014h 4     ? 02FF4000h
      2FFF018h A68h  Zerofilled
      2FFFA80h 160h  Short Cart header (as at 2FFFE00h, but, FOR NDS ROM CARTRIDGE)
      2FFFBE0h 20h   Zerofilled

Below resembles NDS area at 27FFC00h (with added/removed stuff)...

      2FFFC00h 4     NDS Gamecart Chip ID
      2FFFC04h 20h   Zerofilled
      2FFFC24h 5     ? (04 00 73 01 03)
      2FFFC29h 7     Zerofilled
      2FFFC30h 12    GBA Cartridge Header (FF FF FF FF FF 00 FF FF FF FF FF FF)
      2FFFC3Ch 4     Frame Counter maybe? (eg. 1F 01 00 00 in cooking coach)
      2FFFC40h 2     Boot Indicator (1=ROM Cartridge,2=Wifi/tmp?,3=SD/MMC DSiware)
      2FFFC42h 3Eh   Not used (zero)
      2FFFC80h 70h   Wifi FLASH User Settings (fmw[newest_user_settings])
      2FFFCF0h 4     ?           (3D 00 01 6E) (update counter and crc16 ?)
      2FFFCF4h 6     Wifi MAC Address (00 23 CC xx xx xx)              (fmw[036h])
      2FFFCFAh 2     Wifi Channels (usually 1041h = ch1+7+13) (based on fmw[03Ch])
      2FFFCFCh 4     Zero
      2FFFD00h 68h   Zerofilled
      2FFFD68h 4     Bitmask for Supported Languages (3Eh for Europe);\
      2FFFD6Ch 4     Unknown (00,00,00,00)                           ; from
      2FFFD70h 1     Console Region (0=JP,1=US,2=EU,3=AU,4=CHN,5=KOR); HWINFO_S.dat
      2FFFD71h 12    Serial/Barcode (ASCII, 11-12 characters)        ;
      2FFFD7Dh 3     ? (00 00 3C)                                    ;/
      2FFFD80h 0Ch   Zerofilled
      2FFFD8Ch 10h   ARM9 debug exception stack (stacktop 2FFFD9Ch)
      2FFFD9Ch 4     ARM9 debug exception vector (020D3E64h)
      2FFFDA0h 4     02F80000h                                ;\
      2FFFDA4h 4     02FFA674h                                ;
      2FFFDA8h 4     00000000h zero                           ; start addresses?
      2FFFDACh 4     01FF86E0h itcm?                          ;
      2FFFDB0h 4     027C00C0h                                ;
      2FFFDB4h 4     02FFF000h                                ;
      2FFFDB8h 4     03040000h wram?                          ;
      2FFFDBCh 4     03800000h wram?                          ;
      2FFFDC0h 4     0380C3B4h wram?                          ;/
      2FFFDC4h 4     02F80000h                                ;\
      2FFFDC8h 4     02FFC000h ptr to DSi Full Cart Header    ;
      2FFFDCCh 4     00000000h zero                           ; end addresses?
      2FFFDD0h 4     02000000h ram bottom?                    ; (for above nine
      2FFFDD4h 4     027C0780h                                ; start addresses)
      2FFFDD8h 4     02FFF680h                                ;
      2FFFDDCh 4     03040000h wram?                          ;
      2FFFDE0h 4     03800000h wram?                          ;
      2FFFDE4h 4     0380F780h wram?                          ;/
      2FFFDE8h 4     RTC Date at Boot (BCD) (yy,mm,dd,XX) (XX=maybe day-of-week?)
      2FFFDECh 4     RTC Time at Boot (BCD) (hh,ss,mm,0) (hh.bit6=maybe PM or 24h?)
      2FFFDF0h 4     Initial ARM7 Port 4004008h bits (13FBFB06h) (SCFG_EXT)
      2FFFDF4h 1     Initial ARM7 Port 40040xxh bits (C4h)       (SCFG_xxx)
      2FFFDF5h 1     Initial ARM7 Port 400400xh bits (F0h)       (SCFG_xxx)
      2FFFDF6h 2+2   Zerofilled
      2FFFDFAh 1     Warmboot Flag (bptwl[70h] OR 80h, ie. 80h=cold or 81h=warm)
      2FFFDFBh 1     01h
      2FFFDFCh 4     Pointer to TWLCFGn.dat (usually 2000400h) (or 0=2000400h)
      2FFFE00h 160h  Short Cart header (unlike NDS, only 160h, not 170h)
      2FFFF60h A0h   Zerofilled
     37FA414h       "nand:/title/....app"  <-- [1D4h]+3C0h  (without Device List!)
     380C400h 22E4h BIOS Keys (as from Boot Stage 1, see there)
      380F010h 10h   AES key for dev.kp (E5,CC,5A,8B,...) (optional/for launcher)
      380F600h 200h  DSi7 bootstrap relict (at 3FFF600h aka mirrored to 380F600h)
      380FFC0h 4     DSi7 IRQ IF2 Check Bits (hardcoded RAM address) (DSi only)
      380FFC4h 4     DSi7 SCFG_EXT setting
      380FFC8h 2     DSi7 SCFG_misc bits
      380FFDCh ..    DSi7 Debug Stacktop / Debug Vector (0=None)
      380FFF8h 4     DSi7 IRQ IF Check Bits (hardcoded RAM address)
      380FFFCh 4     DSi7 IRQ Handler (hardcoded RAM address)
      xxxxxxxh ?     ARM7i and ARM9 bootcode can be loaded WHERE and WHERE?
      cart_header[1D4h] 400h SD/MMC Device List ARM7 RAM; initialized by firmware

Initial state after DSi BIOS ROM bootcode (when starting eMMC bootcode) requires only a few memory blocks in ITCM, ARM7 WRAM, and AES keyslots:

      1FFC400h 400h  BIOS Keys from FFFF87F4h (C3 02 93 DE ..) RSA keys (8x80h)
      1FFC800h 80h   BIOS Keys from FFFF9920h (30 33 26 D5 ..) Whatever
      1FFC880h 14h   Whatever, should/may be zerofilled?
      1FFC894h 1048h BIOS Keys from FFFF99A0h (99 D5 20 5F ..) Blowfish/NDS-mode
      1FFD8DCh 1048h BIOS Keys from FFFFA9E8h (D8 18 FA BF ..) Blowfish/unused?
      3FFC400h 200h  BIOS Keys from 00008188h (CA 13 31 79 ..) Whatever, 32x10h AES?
      3FFC600h 40h   BIOS Keys from 0000B5D8h (AF 1B F5 16 ..) Whatever, AES?
      3FFC640h 14h   Whatever, must be zerofilled
      3FFC654h 1048h BIOS Keys from 0000C6D0h (59 AA 56 8E ..) Blowfish/DSi-mode
      3FFD69Ch 1048h BIOS Keys from 0000D718h (54 86 13 3B ..) Blowfish/unused?
      3FFE6E4h 44h   eMMC Info (to be relocated to 2FFD7BCh, see there for details)
      4004450h 8     AES Key0.X ("Nintendo") for modcrypt
      4004480h 10h   AES Key1.X (CPU/Console ID and constants) for dev.kp and Tad
      40044B0h 10h   AES Key2.X ("Nintendo DS",...)            for Tad
      40044E0h 1Ch   AES Key3.X/Y (CPU/Console ID and constants) for eMMC
      2000000h ...   Warmboot Param (optional, passed on to New Title)
      2000300h 20h   Warmboot Info  (optional, passed on to Launcher)

BIOS Dumping

BIOSes

      GBA BIOS 16K  (fully dumpable, CRC32=81977335 on GBA with [3F0Ch]=00h)
      GBA BIOS 16K  (fully dumpable, CRC32=A6473709 on NDS/3DS with [3F0Ch]=01h)
      NDS7 BIOS 16K (fully dumpable, CRC32=1280F0D5)
      NDS9 BIOS 4K  (fully dumpable, CRC32=2AB23573)
      DSi7 BIOS 64K (about 41K dumpable)
      DSi9 BIOS 64K (about 41K dumpable)
      3DS9 BIOS 64K (fully dumpable)
      3DS11 BIOS 64K (fully dumpable)
      DSiWifi BIOS 80K on older DSi (fully dumpable)
      DSiWifi BIOS Unknown size on newer DSi (fully dumpable)
      3DSWifi BIOS Unknown size on 3DS (fully dumpable)

GBA BIOS
Contains SWI Functions and Bootcode (for starting cartridges, or booting via Serial Port). The GBA BIOS can be read only by opcodes executed in BIOS area, for example, via the MidiKey2Freq function (most other SWI Functions (like CpuSet) are refusing source addresses within BIOS area).
NDS BIOSes
Contains SWI Functions and Bootcode (for booting from SPI Bus Firmware FLASH memory). The NDS9 BIOS can be dumped without restrictions (eg. via CpuSet, or via LDR opcodes in RAM). The NDS7 BIOS has same restrictions as GBA, ie. reading works only by BIOS opcodes, and not by functions like CpuSet. The GetCRC16 functions does work though (at least for memory at 1204h..3FFFh). As an additional obstacle, memory at 0000h..1203h can be dumped only by opcodes within 0000h..1203h (that memory does mainly contain data, but some of the data values can serve as THUMB LDR opcodes). For details see:
DS Memory Control - BIOS
Note: DSi consoles are containing a copy of the NDS BIOSes, but with BIOSPROT set to 0020h (even when running in NDS mode), so the first 20h bytes of the DSi's NDS7 BIOS aren't dumpable (except via tracing, see below), that 20h bytes should be just same as on original NDS7 though.
DSi BIOSes - Lower 32K-halves (SWI Functions)
The lower 32K of DSi9 doesn't have any restricions. The lower 32K of DSi7 has similar restrictions as NDS7, but with BIOSPROT set to 0020h (instead of 1204h), this is making it more easy to dump memory at 0020h..7FFFh (eg. via GetCRC16), but makes it impossible to dump the exception vectors at 0000h..001Fh, however, they can be deduced by tracing (with timer IRQs):

      ROM:00000000h  EA000006  b 20h   ;dsi7_reset_vector
      ROM:00000004h  EA000006  b 24h   ;dsi7_undef_handler
      ROM:00000008h  EA00001F  b 8Ch   ;dsi7_swi_handler
      ROM:0000000Ch  EA000004  b 24h   ;dsi7_prefetch_abort_handler
      ROM:00000010h  EA000003  b 24h   ;dsi7_data_abort_handler
      ROM:00000014h  EAFFFFFE  b 14h   ;reserved_vector
      ROM:00000018h  EA000013  b 6Ch   ;dsi7_irq_handler
      ROM:0000001Ch  EA000000  b 24h   ;dsi7_fiq_handler

Aside from branch opcodes, above could theoretically contain ALU opcodes that modify R15 (but that would be very unlikely, and would make no difference) (and, the above 20h bytes are dumped/confirmed on 3DS in DSi mode).
DSi BIOSes - Upper 32K-halves (Bootcode, for booting from eMMC memory)
The upper 32K of the DSi9 and DSi7 BIOSes are locked at some point during booting, and there's no known way to dump them directly. However, portions of that memory are relocated to RAM/TCM before locking, and that relocated copies can be dumped.
On a DSi, the following DSi ROM data can be dumped (originally done via Main Memory hacks, ie. with complex external hardware soldered to the mainboard, but it's now also possible via Unlaunch.dsi exploit):

      ROM:FFFF87F4h / TCM:1FFC400h (400h)  (C3 02 93 DE ..) RSA keys (8x80h)
      ROM:FFFF9920h / TCM:1FFC800h (80h)   (30 33 26 D5 ..) Whatever
      ROM:FFFF99A0h / TCM:1FFC894h (1048h) (99 D5 20 5F ..) Blowfish/NDS-mode
      ROM:FFFFA9E8h / TCM:1FFD8DCh (1048h) (D8 18 FA BF ..) Blowfish/unused?
      ROM:00008188h / RAM:3FFC400h (200h)  (CA 13 31 79 ..) Whatever, 32x10h AES?
      ROM:0000B5D8h / RAM:3FFC600h (40h)   (AF 1B F5 16 ..) Whatever, "common key"?
      ROM:0000C6D0h / RAM:3FFC654h (1048h) (59 AA 56 8E ..) Blowfish/DSi-mode
      ROM:0000D718h / RAM:3FFD69Ch (1048h) (54 86 13 3B ..) Blowfish/unused?

On a 3DS, the following "DSi ROM data" can be dumped from the 2470h-byte DSi key area in 3DS memory at ARM9 ITCM 01FFD000h..01FFF46F (via 3DS exploits that are capable of executing code on ARM9 side):

      ROM:FFFF87F4h / 3DS:01FFD000h  200h  RSA keys 0..3 (4x80h)
      ROM:00008308h / 3DS:01FFD200h  80h   some AES keys
      ROM:FFFF9920h / 3DS:01FFD280h  80h   whatever
      ROM:0000B5D8h / 3DS:01FFD300h  40h   AES keys and values (common etc)
      ROM:?         / 3DS:01FFD340h  A0h   misc "Nintendo" string etc.
      ROM:0000C6D0h / 3DS:01FFD3E0h  1048h Blowfish for DSi-mode
      ROM:FFFF99A0h / 3DS:01FFE428h  1048h Blowfish for DS-mode

The 3DS does have only half of the DSi keys (the extra keys might be used for DSi debug version, but aren't needed for normal DSi software).
The 40h-byte area for ROM:0000B5D8h can be fully dumped from 3DS ITCM, the same vales should also exist in DSi ITCM, but the DSi zerofills a 10h-byte fraction of that area after initialization, and it doesn't seem be possible to read that values via Main Memory hacks (most of that erased values can be found in AES keyslots though).
The A0h-byte area is found only in 3DS ITCM, it should also exist somewhere in DSi ROM, but isn't relocated to DSi ITCM (however, the relevant values can be found in AES keyslots, eg. the "Nintendo" string).
Checksums for BiosDSi.rom (20000h bytes)

      Offset Size  CRC32
      00000h 8000h 5434691Dh                ;\
      08000h 188h  ?                        ;
      08188h 180h  E5632151h  (not 3ds)     ;
      08308h 80h   64515306h                ;
      08388h 3250h ?                        ;
      0B5D8h 20h   85BE2749h                ; ARM7
      0B5F8h 10h   25A46A54h  (3ds only)    ;
      0B608h 10h   E882B9A9h                ;
      0B618h 10B8h ?                        ;
      0C6D0h 1048h 3B5CDF06h                ;
      0D718h 1048h 5AC363F9h  (not 3ds)     ;
      0E860h 18A0h ?                        ;/
      10000h 8000h 11E7C1EAh                ;\
      18000h 7F4h  ?                        ;
      187F4h 200h  4405D4BAh                ;
      189F4h 200h  2A32F2E7h  (not 3ds)     ;
      18BF4h D2Ch  ?                        ; ARM9
      19920h 80h   2699A10Fh                ;
      199A0h 1048h A8F58AE7h                ;
      1A9E8h 1048h E94759ACh  (not 3ds)     ;
      1BA30h 45D0h ?                        ;/
      ?      A0h   180DF59Bh  (3ds only)    ;-whatever, "Nintendo" string etc.
      ?      80h   ........h  (TWL-FIRM)    ;-RSA key for eMMC boot info

Checksums for the 'whole' 20000h-byte file (with unknown/missing areas zerofilled):

      180DF59Bh (tcm/ram dump)  (missing 10h bytes)
      03A21235h (3ds dump)      (missing 180h+200h+1048h+1048h bytes)
      CDAA8FF6h (combined dump) (missing only the unknown "?" areas)

3DS BIOS
Can be dumped by crashing the 3DS with wrong voltages, or by using sighax to crash the bootrom before disabling the upper 32Kbyte halves of the ARM9/ARM11 ROMs.
DSiWifi BIOS
The Wifi BIOS can be dumped by using the WINDOW_DATA register via SDIO CMD53.
Further DSi BIOSes
The DSi cameras and several other I2C/SPI devices are probably having BIOS ROMs, too. Unknown if/how that ROMs are dumpable.
DSi BIOS Dumping via voltage errors
Lowering VDD12 for a moment does work quite reliable for crashing the ARM9 and trapping the 2FFFD9Ch vector in Main RAM. The problem is that Main RAM seems to be disabled during bootstage 1 (it gets enabled at begin of bootstage 2 via EXMEMCNT, that is, shortly after the upper BIOS 32Kbyte areas are disabled). More on that here:

      http://4dsdev.kuribo64.net/thread.php?id=130

One theory/idea (from dark_samus) is that EXMEMCNT controls the CE2 pin on the Main RAM chip, so one could try to rewire that pin to get Main RAM enabled regardless of EXMEMCNT, if that's actually working, then trapping the 2FFFD9Ch vector should work even while BIOS ROMs are fully readable.

External Connectors

External Connectors
AUX GBA Game Pak Bus
AUX DS Game Card Slot
AUX Link Port
AUX Sound/Headphone Socket and Battery/Power Supply
AUX DSi SD/MMC Pin-Outs
Getting access to Internal Pins
AUX Opening the GBA
AUX Mainboard
AUX DSi Component Lists
AUX DSi Internal Connectors
AUX DSi Chipset Pinouts
More Internal Stuff
Pinouts - CPU - Signal Summary
Pinouts - CPU - Pinouts
Pinouts - Audio Amplifiers
Pinouts - LCD Cables
Pinouts - Power Switches, DC/DC Converters, Reset Generators
Pinouts - Wifi
Pinouts - Various
Xboo Multiboot Cable
AUX Xboo PC-to-GBA Multiboot Cable
AUX Xboo Flashcard Upload
AUX Xboo Burst Boot Backdoor
DS Xboo

AUX GBA Game Pak Bus

Game Pak Bus - 32pin cartridge slot
The cartridge bus may be used for both CGB and GBA game paks. In GBA mode, it is used as follows:

     Pin    Name    Dir  Expl.
     1      VDD     O    Power Supply 3.3V DC
     2      PHI     O    System Clock (selectable none, 4.19MHz, 8.38MHz, 16.78MHz)
     3      /WR     O    Write Select    ;\latched address to be incremented on
     4      /RD     O    Read Select     ;/rising edges of /RD or /WR signals
     5      /CS     O    ROM Chip Select ;-A0..A15 to be latched on falling edge
     6-21   AD0-15  I/O  lower 16bit Address    and/or  16bit ROM-data (see below)
     22-29  A16-23  I/O  upper 8bit ROM-Address   or    8bit SRAM-data (see below)
     30     /CS2    O    SRAM Chip Select
     31     /REQ    I    Interrupt request (/IREQ) or DMA request (/DREQ)
     32     GND     O    Ground 0V

When accessing game pak SRAM, a 16bit address is output through AD0-AD15, then 8bit of data are transferred through A16-A23.
When accessing game pak ROM, a 24bit address is output through AD0-AD15 and A16-A23, then 16bit of data are transferred through AD0-AD15.
The 24bit address is formed from the actual 25bit memory address (byte-steps), divided by two (halfword-steps).
Pin Pitch is 1.5mm.
8bit-Gamepak-Switch (GBA, GBA SP only) (not DS)
A small switch is located inside of the cartridge slot, the switch is pushed down when an 8bit cartridge is inserted, it is released when a GBA cartridge is inserted (or if no cartridge is inserted).
The switch mechanically controls whether VDD3 or VDD5 are output at VDD35; ie. in GBA mode 3V power supply/signals are used for the cartridge slot and link port, while in 8bit mode 5V are used.
The switch additionally drags IN35 to 3V when an 8bit cart is inserted, the current state of IN35 can be determined in GBA mode via Port 4000204h (WAITCNT), if the switch is pushed, then CGB mode can be activated via Port 4000000h (DISPCNT.3), this bit can be set ONLY by opcodes in BIOS region (eg. via CpuSet SWI function).
In 8bit mode, the cartridge bus works much like for GBA SRAM, however, the 8bit /CS signal is expected at Pin 5, while GBA SRAM /CS2 at Pin 30 is interpreted as /RESET signal by the 8bit MBC chip (if any). In practice, this appears to result in 00h being received as data when attempting to read-out 8bit cartridges from inside of GBA mode.

AUX DS Game Card Slot

      Pin    Dir  Name  Connection in cartridge
      1   >  -    GND   (ROM all unused Pins, EEPROM Pin 4 = VSS)
      2      Out  CLK   (4MB/s, ROM Pin 5, EEPROM Pin 6 = CLK)
      3   N  -    ?     (ROM Pin 17) (Seems to be not connected in console)
      4   i  Out  /CS1  (ROM Pin 44) ROM Chipselect
      5   n  Out  /RES  (ROM Pin 42) Reset, switches ROM to unencrypted mode
      6   t  Out  /CS2  (EEPROM Pin 1) EEPROM Chipselect
      7   e  In   IRQ   (GND)
      8   n  -    3.3V  (ROM Pins 2, 23, EEPROM Pins 3,7,8 = /W,/HOLD,VCC)
      9   d  I/O  D0    (ROM Pin 18)
      10  o  I/O  D1    (ROM Pin 19)
      11     I/O  D2    (ROM Pin 20)
      12  C  I/O  D3    (ROM Pin 21)
      13  0  I/O  D4    (ROM Pin 24)
      14  1  I/O  D5    (ROM Pin 25)
      15  -  I/O  D6    (ROM Pin 26, EEPROM Pin 2 = Q = Data EEPROM to NDS)
      16  0  I/O  D7    (ROM Pin 27, EEPROM Pin 5 = D = Data NDS to EEPROM)
      17  1  -    GND   (ROM all unused Pins, EEPROM Pin 4 = VSS)

Chipselect High-to-Low transitions are invoking commands, which are transmitted through data lines during next following eight CLK pulses, after the command transmission, further CLK pulses are used to transfer data, the data transfer ends at chipselect Low-to-High transition.
Data should be stable during CLK=LOW period throughout CLK rising edge.
Note: Supply Pins (1,8,17) are slightly longer than other pins. Pin pitch is 1.5mm.
The DS does also have a 32pin cartridge slot, that slot is used to run GBA carts in GBA mode, it can be also used as expansion port in DS mode.

AUX Link Port

Serial Link Port Pin-Out (GBA:"EXT" - GBA SP:"EXT.1")

      Pin  Name  Cable
      1    VDD35 N/A       GBA Socket     GBA Plug   Old "8bit" Plug
      2    SO    Red       ___________    _________    ___________
      3    SI    Orange   |  2  4  6  |  / 2  4  6 \  |  2  4  6  |
      4    SD    Brown     \_1_ 3 _5_/   \_1_ 3 _5_/   \_1__3__5_/
      5    SC    Green         '-'           '-'
      6    GND   Blue      Socket Outside View / Plug Inside View
      Shield     Shield

Note: The pin numbers and names are printed on the GBA mainboard, colors as used in Nintendo's AGB-005 and older 8bit cables.
Serial Link/Power Supply Port (GBA-Micro: "EXT.")

      1  In  DC (Supply 5.2VDC)  ___________________
      2  Out V3 (SIO 3.3VDC)    |  1 2 3 4 5 6 7 8  |
      3  I/O SO (SIO RCNT.3)    | ================= |
      4  I/O SI (SIO RCNT.2)     \_________________/
      5  I/O SD (SIO RCNT.1)
      6  I/O SC (SIO RCNT.0)
      7  OUT DG (SIO GROUND)
      8  In  DG (Supply GROUND)
      -  -   -  (Shield not connected)

Cable Diagrams (Left: GBA Cable, Right: 8bit Gameboy Cable)

      Big Plug  Middle Socket  Small Plug    Plug 1         Plug 2
       SI _________________     ____ SI       SI ______  ______SI
       SO ____________SO   |__ | ___ SO       SO ______><______SO
       GND____________GND______|____GND       GND_____________GND
       SD ____________SD____________ SD       SD               SD
       SC ____________SC____________ SC       SC _____________ SC
       Shield_______Shield_______Shield       Shield_______Shield

Normal Connection
Just connect the plugs to the two GBAs and leave the Middle Socket disconnected, in this mode both GBAs may behave as master or slave, regardless of whether using big or small plugs.
The GBA is (NOT ???) able to communicate in Normal mode with MultiPlay cables which do not have crossed SI/SO lines.
Multi-Play Connection
Connect two GBAs as normal, for each further GBAs connect an additional cable to the Middle socket of the first (or further) cable(s), up to four GBAs may be connected by using up to three cables.
The GBA which is connected to a Small Plug is master, the slaves are all connected to Large Plugs. (Only small plugs fit into the Middle Socket, so it's not possible to mess up something here).
Multi-Boot Connection
MultiBoot (SingleGamepak) is typically using Multi-Play communication, in this case it is important that the Small plug is connected to the master/sender (ie. to the GBA that contains the cartridge).
Non-GBA Mode Connection
First of all, it is not possible to link between 32bit GBA games and 8bit games, parts because of different cable protocol, and parts because of different signal voltages.
However, when a 8bit cartridge is inserted (the GBA is switched into 8bit compatibility mode) it may be connected to other 8bit games (monochrome gameboys, CGBs, or to other GBAs which are in 8bit mode also, but not to GBAs in 32bit mode).
When using 8bit link mode, an 8bit link cable must be used. The GBA link cables won't work, see below modification though.
Using a GBA 32bit cable for 8bit communication
Open the middle socket, and disconnect Small Plugs SI from GND, and connect SI to Large Plugs SO instead. You may also want to install a switch that allows to switch between SO and GND, the GND signal should be required for MultiPlay communication only though.
Also, cut off the plastic ledge from the plugs so that they fit into 8bit gameboy sockets.
Using a GBA 8bit cable for 32bit communication
The cable should theoretically work as is, as the grounded SI would be required for MultiPlay communication only. However, software that uses SD for Slave-Ready detection won't work unless when adding a SD-to-SD connection (the 8bit plugs probably do not even contain SD pins though).

AUX Sound/Headphone Socket and Battery/Power Supply

GBA, GBA-Micro, NDS, and NDS-Lite: Stereo Sound Connector (3.5mm, female)

      Tip     Audio Left         ___ ___ _____.-----------.
      Middle  Audio Right       (___|___|_____|           |
      Base    Ground              L   R   GND '-----------'

The NDS socket doesn't fully match regular 3.5mm plugs, one needs to cut-off a portion of the DS case to be able to fully insert the plug, which still requires a lot of pressure, furthermore, when fully inserted, left/right become shortcut to mono, so one needs to pull-back the plug a bit to gain stereo output.
GBA SP and NDS - Power/Headphone Socket (EXT.2)

      Pin SP   NDS  Expl.
      1   P31  SL   Audio LOUT                          _____________
      2   P32  VIN  Supply Input (DC 5.2V)           SW| 5   ___   1 |SL
      3   P33  SR   Audio ROUT                         | ----   ---- |
      4   P34  SG   Audio GND (via 100uF to GND)       |_6__4   3__2_|
      5   P35  SW   Audio Speaker Disable (GND=Dis)    GND SG\_/SR VIN
      6        GND  Supply GND
      Shield        GND

External power input is used to charge the built-in battery, it cannot be used to run the SP without that battery.
NDS-Lite - Power Socket

      Pin  Expl.                                          __________
      1    Supply Input (DC 5.2V)                        /  ======  \
      2    Supply GND                                GND |___2__1___| VIN

GBA-Micro - Power Socket
Uses an 8pin socket (which combines SIO and Power), for pin-outs, see
AUX Link Port
External Power Supply
GBA: DC 3.3V (no separate power socket, requires 2xAA-battery-shaped adapter)
GBA-SP/NDS: DC 5.2V (or DC 5V) (special connector on power/headphone socket)
NDS-Lite: DC 5.2V (or DC 5V) (another special connector on power socket)
Internal Battery Supply
GBA: 2xAA (3V)
GBA-SP: Li-ion 3.7V, 600mAh (built-in, recharge-able)
GBA-Micro: Li-ion 3.8V, 460mAh (built-in, recharge-able)
NDS: Li-ion 3.7V, 850mAh (built-in, recharge-able)
NDS-Lite: Li-ion 3.7V, 1000mAh (built-in, recharge-able)
Using PC +5V DC as Power Supply
Developers whom are using a PC for GBA programming will probably want to use the PC power supply (gained from disk drive power supply cable) for the GBA as well rather than dealing with batteries or external power supplies.
GBA: To lower the voltage to approximately 3 Volts use two diodes, type 1N 4004 or similar, the ring printed onto the diodes points towards the GBA side, connected as such:

      PC +5V (red)   --------|>|---|>|--------  GBA BT+
      PC GND (black) -------------------------  GBA BT-

GBA SP, GBA Micro, NDS, and NDS-Lite: Works directly at +5V connected to EXT.2 socket (not to the internal battery pins), without any diodes.

AUX DSi SD/MMC Pin-Outs

SD/MMC Transfer Modes

      Transfer Modes        SPI-Mode    1-bit-Bus  4-bit-Bus   SDIO
      MMC Cards             Optional    Yes        MMCplus     No
      SD Cards              Yes         Yes        Optional??  Optional

Note: SDIO is an extension to the SD protocol, allowing to access other non-memory-card hardware (such like cameras or network adaptors) via SD connectors.
Note: Original MMC cards don't support 4-bit bus, but there are revisions like MMCplus and MMCmobile (with extra pin rows) which do support 4-bit and 8bit bus.
SD/MMC Pin-Outs

      MMC  MMCplus SD  miniSD microSD SPI-Mode    1-bit-Bus   4-bit/8bit-Bus
      1    1       1   1      2       /CS         CardDetect  Data3
      2    2       2   2      3       DataIn      CMD/REPLY   CMD/REPLY
      3    3       3   3      --      GND         GND         GND
      4    4       4   4      4       VDD         VDD         VDD
      5    5       5   5      5       CLK         CLK         CLK
      6    6       6   6      6       GND         GND         GND
      7    7       7   7      7       DataOut     Data        Data0
      --   8       8   8      8       /IRQ (SDIO) /IRQ (SDIO) Data1 or /IRQ (SDIO)
      --   9       9   9      1       NC          NC          Data2
      --   10      --  --     --      NC          NC          Data4  ;\
      --   11      --  --     --      NC          NC          Data5  ; MMCplus
      --   12      --  --     --      NC          NC          Data6  ; 8bit
      --   13      --  --     --      NC          NC          Data7  ;/
      --   --      --  10     --      Reserved    Reserved    Reserved
      --   --      --  11     --      Reserved    Reserved    Reserved

Moreover, the card sockets (not the cards themselves) are usually containing a Card Detect switch, and, for SD card sockets, also a write protect switch:

      --   --      CD  CD     CD      Card Detect (senses if card is inserted)
      --   ---     WP  --     --      Write Protect (senses position of LOCK tab)

Note that the LOCK tab on SD cards is just a small piece of plastic without any electronics attached to it, the actual switch/sensor is located in the SD card socket (ie. the LOCK works much like the write-protect tabs on audio tapes, video tapes, and floppy discs).
Card detect can be an actual switch (however, some sockets are simply having dual contacts for Pin 3 (GND), one being GND, and the other becoming GNDed when a cartridge is inserted).
SD/MMC Card Shapes

         ______________________________
        /    __ __ __ __ __ __ __      |
       /    |  |  |  |  |  |  |  |     |
      |     | 1| 2| 3| 4| 5| 6| 7|     |
      | MMC |__|__|__|__|__|__|__|     |
      |    ______________________________
      |   /    __ __ __ __ __ __ __ _    |
      |  /  __|  |  |  |  |  |  |  | |   |
      | |  |  | 1| 2| 3| 4| 5| 6| 7|8|   | MMCplus:
      | |  | 9|__|__|__|__|__|__|__| |   | pinout is same as 9pin SD cards,
      | |  |_ |_ __ __       __ __ | |   | with extra DAT4-7 on pin10-13
      | |    |  | 1| 1|     | 1| 1|  |   |
      | |MMC | 9| 0| 1|     | 2| 3| 8|   |
      | |plus|__|__|__|     |__|__|__|   |
      | |    ______________________________
      | |   /    __ __ __ __ __ __ __ _    |
      | |  /  __|  |  |  |  |  |  |  | |   |
      | | |  |  | 1| 2| 3| 4| 5| 6| 7|8|   |
      | | |  | 9|__|__|__|__|__|__|__|_|   |
      | | '. |__| SD                      .'      SD Write Protect Tab
      | |  |  _________________________   |   <-- Unlock position
      | | .' |  _ _ _ _ _ _ _ _ _ _ _  |  |#  <-- LOCK position
      | | |  | | | | | |1|1| | | | | | |  '.
      | | |  | |9|1|2|3|0|1|4|5|6|7|8| |   |
      |_| |  | |_|_|_|_|_|_|_|_|_|_|_| |   |
        | |  |   miniSD                 \  |
        | |  |     _________________     | |
        | |  |    | _ _ _ _ _ _ _ _ |    | |
        | |  |    || | | | | | | | ||    | |
        |_|  |    ||1|2|3|4|5|6|7|8||    | |
          |  |    ||_|_|_|_|_|_|_|_||    | |
          |  |   /                  |    | |
          |  |  |_  microSD         |    | |
          |  |    |                 |    | |
          |  |   /                  |    | |
          |  |  |                   |    | |
          |  |  |                   |    | |
          |  |_ |                   | ___| |
          |____ |___________________| _____|

SD/MMC Signals for on-board eMMC chip on DSi Mainboard "C/TWL-CPU-01"
Below are the required eMMC signals. Low-end hardware may get away with using Data0 as single data line (eg. small microprocessors with few I/O pins), but higher quality hardware should support 4bit data mode (eg. off-the-shelve SD card interfaces may insist on all four data lines being connected). Data3 (aka CardDetect) might be also needed even in 1bit data mode.

                             _______ CLK (SPI: CLK)    _______ Data3 (SPI: /CS)
                            |                         | ______ Data0 (SPI: DataOut)
                     <#>  <#>  <#>                    || _____ Data1
                    EM14  R113 C130                   ||| ____ Data2
            .------------------------.                ||||
            |                        |          <#>  <####> #  #
            |                        |     U5   C57   RA4  C54 C55
            |  Shielding-plate       '---.  o .------------------.
            |                            |    |o                 |
            |                            |    |                  |
            |                            |    |  Samsung     834 |
            |                            |    |  KMAPF0000M-S998 |
            |  CPU              RAM      |    |                  |
            |                            |    |                  |
            |                            |    '------------------'
            '----------------------------'     R94 R54  C50 C51
                 |                             <#> <#>  <#> <#>
                 |                               |
                 |___ shield = GND               |___ CMD/REPLY (SPI: DataIn)

For other DSi mainboards, see:

      http://www.dsibrew.org/wiki/Hardware

The KMAPF0000M chip does probably NOT support SPI mode, and it does probably support only MMC protocol (not SD protocol). That, assuming that the chip does have similar capabilities as in KMCEN0000M datasheet (there's no KMAPF0000M datasheet online).
SD/MMC Signals and 3DS Hardmodding
Pictures with eMMC solder pads for 3DS mainboards boards can be found at:

      https://www.3dbrew.org/wiki/Hardware

However, hardmodding is much more difficult for 3DS as than for DSi. Three 3DS-specific problems:

      CLK resistor
      The 3DS tends to hold CLK low, and there is no resistor installed between
      3DS CPU and eMMC chip, so the card reader may be unable to pull CLK high.
      As workaround, install a resistor in the CLK line (the mainboard has square
      solder pads just for that purpose) (330..660 ohms have worked for me, I am
      currently using 470 ohms; smaller resistors like 0..120 ohm won't work with
      the card reader, and much larger resistors won't work with the 3DS itself).
      Incompatible Card readers
      Newer 3DS/New3DS models seem to contain eMMC chips that are incompatible with
      older card readers, maybe because their firmware/driver treats the CSD
      version number as unknown, despite of the eMMC chip being nothing special.
      As workaround, try to use some newer card readers, or use a DSi console as
      card reader (ie. write you software that can happily ignore CSD version).
      Mechanical problems
      Most solder points are on the wrong PCB side (unlike as on DSi, you will
      need to remove the 3DS mainboard). Whereas, the connector for the top screen
      backlight is rated to survive max 10 mating cycles (mine died after 5-7).
      Part of the problem was that I wasn't aware of the other problems mentioned
      above (so I had removed the mainboard several times to check my soldering),
      and, the connector is 'underneath' of the PCB, making it difficult to insert
      the cable straight and smoothly, causing pins in the connector may get bent,
      making it impossible to insert the ribbon cable (maybe it will help if you
      take time, and don't impatiently try to push the cable into the socket).

Soldering Notes
Connect CLK/CMD to the pins on right side of R113/R94 (as shown in the drawing). Connect Data3/0/1/2 to the LOWER pins of RA4 (unlike as shown in the drawing, ie. NOT to the upper pins), or alternately, connect them to the four vias below of RA4. Connect GND somewhere to shielding plate, for example.
My own setup is: A 8pin ribbon cable soldered to a spare SD-to-SDmicro adapter (used as connector for SD/MMC slots), the ribbon cable is wired to a small circuit board, which is soldered to the shielding of the DSi's game cartridge slot (just for mechanical stability). Next, some fragile wires are forwarded from the circuit board to the actual mainboard pins.
Software Notes
Remove the DSi wifiboard (not absolutely required, but doing so will hang the DSi before accessing the eMMC, which ensures that the eMMC won't be accessed simultaneously by the DSi and PC). Switch on the DSi. Connect it to SD/MMC card reader. Under Windows, the eMMC should show up as MMC-storagedevice in Windows Explorer (alongsides with your HDD drives), due to the encryption it isn't possible to access the filesystem or logical partitions of the chip. However, the physical sectors can be accessed.
For example, using HxD hex editor: Click Extras, Open Disk, and select the MMC (in HxD it shows up under Physical Discs: as Removeable Disk). Click Edit, Select All, Copy. Click File, New. Then Edit, Paste. And finally File, Save As for saving an image of the whole 240MByte FLASH chip.
I've tried accessing the eMMC on two PCs, one worked, the other didn't:

      Win98 with External Card reader: Windows didn't recognize the MMC chip
      Win7  with External Card reader: Okay (recognized as "unformatted" disk)
      Win7  with Internal Card reader: Okay (recognized as "unformatted" disk)

For testing the Operating System/Card Reader side: Connect a normal SD card to the card reader. If HxD is showing it as both Logical Disc and Physical Disc, then you are fine. If it shows up as Logical Disc only, then your setup won't work for accessing the eMMC chip.

AUX Opening the GBA

Since Nintendo uses special screws with Y-shaped heads to seal the GBA (as well as older 8bit gameboys), it's always a bit difficult to loosen these screws.
Using Screwdrivers
One possible method is to use a small flat screwdriver, which might work, even though it'll most likely damage the screwdriver.
Reportedly, special Y-shaped screwdrivers for gameboys are available for sale somewhere (probably not at your local dealer, but you might find some in the internet or elsewhere).
Destroying the Screws
A more violent method is to take an electric drill, and drill-off the screw heads, this might also slightly damage the GBA plastic chase, also take care that the metal spoons from the destroyed screws don't produce shortcuts on the GBA mainboard.
Using a selfmade Screwdriver
A possible method is to take a larger screw (with a normal I-shaped, or X-shaped head), and to cut the screw-tip into Y-shape, you'll then end up with an "adapter" which can be placed in the middle between a normal screwdriver and gameboy screws.
Preferably, first cut the screw-tip into a shape like a "sharp three sided pyramid", next cut notches into each side. Access to a grinding-machine will be a great benefit, but you might get it working by using a normal metal-file as well.
Opening the GBA Micro
- open the case with appropriate screwdriver or drilling machine or whatever
- remove the plastic front-plate (there are two snap-ins inside at ONE side)
- remove the mainboard and screen and plastic skeleton from the metal case
- remove the start/select daughter-board from the plastic skeleton
- remove the plastic skeleton (move the screen through the skeleton)
- remove the screen (lift lcd socket front-side, backlight socket rear-side)
Opening the NDS-Lite
- open the case with appropriate screwdriver or drilling machine or whatever
- remove the RFU unit, and the 4-pin touch-screen cable (under the RFU unit)
- remove the mainboard together with the lower screen
- remove the upper/lower screen cables (on the rear-side of the mainboard)

AUX Mainboard

Other possibly useful signals on the mainboard...
FIQ Signal
The FIQ (Fast Interrupt) signal (labeled FIQ on the mainboard) could be used as external interrupt (or debugging break) signal.
Caution: By default, the FIQ input is directly shortcut to VDD35 (+3V or +5V power supply voltage), this can be healed by scratching off the CL1 connection located close to the FIQ pin (FIQ still appears to have an internal pull-up, so that an external resistor is not required).
The GBA BIOS rejects FIQs if using normal ROM cartridge headers (or when no cartridge is inserted). When using a FIQ-compatible ROM header, Fast Interrupts can be then requested by pulling FIQ to ground, either by a push button, or by remote controlled signals.
RESET Signal
The RESET signal (found on the mainboard) could be used to reset the GBA by pulling the signal to ground for a few microseconds (or longer). The signal can be directly used (it is not shortcut to VDD35, unlike FIQ).
Note: A reset always launches Nintendo's time-consuming and annoying boot/logo procedure, so that it'd be recommend to avoid this "feature" when possible.
Joypad Signals
The 10 direction/button signals are each directly shortcut to ground when pressed, and pulled up high otherwise (unlike 8bit gameboys which used a 2x4 keyboard matrix), it'd be thus easy to connect a remote keyboard, keypad, joypad, or read-only 12bit parallel port.

AUX DSi Component Lists

DSi Mainboard "C/TWL-CPU-01" Components

      U1 352pin   CPU TWL       (under shielding plate)                    ;\under
      U2   ?pin   RAM 8Mx16, Fujitsu MB82DBS08164D-70L, NEC uPD46128512AF1 ;/shield
      U3  56pin   "TexasIns 72071B0" or "Mitsumi 3317A" (powerman?) (right of NAND)
      U4  48pin   "AIC3000D, TI 89K, EXDK G4" (PAIC3 codec? above headphone socket)
      U5   ?pin   Samsung KMAPF0000M-S998 (eMMC, 256Mbyte NAND FLASH)
      U6  36pin   "BPTWL, K007K, 0902KM00D" (small/square, left of cartridge slot)
      U7   8pin   "AOK, S8BXS" (ISL95810, I2C potentiometer)         ;\on PCB
      U8   8pin   "7BDS" (PCA9306, I2C voltage translator)           ;/backside
      U9  12pin   "199A, 01IU" (Seiko S-35199A01) (RTC) ;under shielding plate (A)
      U10  4pin   "6800" or "688F" Hinge Magnet Sensor (PCB backside, near A/B/X/Y)
      U11 10pin   ",\\ 908, 335A" or "2005D, 8350" (right of cartridge slot)
      U12  5pin   "L8NX" or "C7JHN" (upper-right of PCB back-side) ;text layer (B)
      U13  5pin   Backlight 1, "U01" or "KER"  ;\lower-right board edge
      U14  5pin   Backlight 2, "U01" or "KER"  ;/see text-layer (B)
      U15  4pin   ",\\ T34" (near external power input)
      U16     -   N/A
      U17  6pin   "VY" or "Z198" (in lower-right, on PCB backside)
      U18  6pin   "YJ" (above headphone socket)
      U19  5pin   "E30H6" or "L2SX" (at lower right of cartridge slot)
      Q1   6pin   external power supply related
      Q2    pin   N/A ?
      Q3   6pin   ... above battery plug
      Q4   3pin   maybe MUTE for SR  ;\old TWL-CPU-01 mainboard only
      Q5   3pin   maybe MUTE for SL  ;/(replaced by Q17?/Q18? on newer boards)
      Q6   6pin   MC1_VDD power ON (supply)
      Q7   3pin   MC1_VDD power OFF (pulldown)
      Q8    pin   N/A ?
      Q9    pin   N/A ?
      Q10   pin   N/A ?
      Q11  3pin   BLUE (LED)   ;\LEDs (note: the other LEDs, ORANGE
      Q12  3pin   YELLOW (LED) ;      and YELLOW, are driven directly)
      Q13  3pin   CAM_LED      ;/
      Q14  3pin   not installed (above powerman chip)
      Q15  3pin   not installed (above powerman chip)
      Q16  3pin   VDD-5 related, near DPAD socket
      Q17? 6pin   maybe MUTE  ;\  ;\new TWL-CPU-10 mainboard only
      Q18? 6pin   maybe MUTE  ;/  ;/(formerly Q4/Q5 on older boards)
      X1   4pin   16.756  (rectangular oscillator)        ;\under shielding plate
      X2   4pin   CB837 or CB822 (long slim osc) for RTC? ;/text layer: see (A)
      F1   2pin   Fuse for external power input
      SW1  2pin   Button A (right)
      SW2  2pin   Button B (lower)
      SW3  2pin   Button X (upper)
      SW4  2pin   Button Y (left)
      SW5  2pin   Button Select (lower)
      SW6  2pin   Button Start  (upper)
      P1  19pin   NDS/DSi cartridge slot (17pin slot + 2pin switch at right side)
      P2      -   N/A
      P3      -   N/A
      P4   8pin   External microphone/headphone combo socket
      P5  50pin   Wifi-Daughterboard
      P6      -   N/A
      P7  47pin   To UPPER lcd screen (video+backlight+speakers) (on PCB backside)
      P8  37pin   To LOWER lcd screen (video signals)
      P9  25pin   To UPPER lcd screen (signals for both cameras, and camera led)
      P10  4pin   To LOWER lcd screen (touchpad X-,Y-,X+,Y+)
      P11  2pin   External Power Supply input (4.6V DC IN)
      P12     -   N/A
      P13     -   N/A
      P14     -   N/A
      P15 15pin   To battery/DPAD/PowerButton board (and onwards to 3xLEDs)
      P16 26pin   To bottom cover (SD Slot and L/R/VOL+/- buttons)
      P17  2pin   Battery cable (lower-right) ;see text-layer (B)
      P18  4pin   To LOWER lcd screen (backlight cathode/anode)
      P19  1pin   Shielding-Plate for CPU (lower clip)
      P20  1pin   Shielding-Plate for CPU (upper clip)
      P21  1pin   Shielding-Plate for CPU (right clip)
      P22     -   N/A
      P23  2pin   To Internal Microphone (via orange shielded wire)

DSi Front/bottom-Side Text Layer sections (in upper left of mainboard)

      (A)  For components underneath of shielding plate
      (B)  For components in lower-right board edge (near battery connector)
      (C)  For components at middle/right of cartridge slot
      (D)  For components left of U4 (left board edge)
      (E)  For components right of U4 (above headphone socket)
      (F)  For components at lower/right of cartridge slot

DSi Back/top-Side Text Layer sections (at various places)

      (A)  at top/middle,  for components at upper right edge
      (B)  at middle/left, for components near upper right edge
      (C)  at lower/left,  for components left of Y-button
      (D)  at lower/righz, for components at right edge

DSi Wifi Daughterboard (DWM-W015) (older DSi version)
PCB Text: "RU (S)-717V 01 ,\\" or "RU (S)-717V 03 ,\\" or "FK RU 06 ,\\"

      U   56pin "Mitsumi, Japan, 844L, MM3218" (same as in DS Lite)
      U  132pin "ROCm, Atheros, AR6002G-AC1B, E19077.1B, 0844, Taiwan"
      U    8pin I2C EEPROM "408F, B837" (HN58X2408F; 1Kx8 for atheros calibration)
      U    8pin SPI FLASH big chip "45PE10V6, HPASC VS, KOR 8364, ST"  ;\either one
      U    8pin SPI FLASH tiny chip "5A32, 8936?"                      ;/installed
      U    8pin "4P, K" or "S6, K" (odd 3+1+3+1 pin package, near antenna)
      U    4pin "3VP, OT" or "3VB, OS" (at board edge, near 50pin connector)
      X    4pin "26.000, 9848" (bigger oscillator, for atheros chip)
      X    4pin "22.000, xxxx" (smaller oscillator, for mitsumi chip)
      P   50pin Connector to Mainboard
      P    2pin Connector for Antenna (shielded white cable)

The "3VP/3VP" thing is some 1.2V voltage regulator (sth like LP3983 or TPS799xx or similar).
White PCB sticker (underneath of the black isolation sticker): "DWM-W015, IC:4250A-DWMW015, FCC ID:EW4DWMW015, [R]003WWA080444, [T]D080261003, MADE IN PHILIPINES, MITSUMI ELEC. CO., LTD."
DSi Wifi Daughterboard (DWM-W024) (newer DSi version)
PCB Text: "FB RU 06 ,\\"

      U   76pin "ROCm, Atheros, AR6013G-AL1C" (or 80pin, with 4pins at edges?)
      U    8pin I2C EEPROM? "4DA?, D940?"   ;maybe I2C eeprom for atheros
      U    8pin SPI FLASH "5A32, 8937?"   ;FLASH (small solder pads)
      U    8pin SPI FLASH not installed (alternate bigger solder pads for FLASH?)
      U    4pin "?" (at board edge, near 50pin connector)
      X    4pin "??" (oscillator, near ROCm chip)
      P   50pin Connector to Mainboard
      P    2pin Connector for Antenna (shielded white cable)

DSi Wifi Daughterboard (J27H020) (alternate newer DSi version)
This seems to be functionally same as DWM-W024, but the PCB is different, and the circuit seems to use a different voltage regulator, and includes solder pads for some additional uninstalled components. And the shielding is difficult to remove because it's soldered all way round (rather than just at some solder points).

     Sticker 1:
      HON HAI PRECISION IND.CO.,LTD.        ;aka Foxconn
      MODEL: J27H020
      [R] 003WWA100195
      [T] D100196003
      FCC ID: MCLJ27H020
      IC: 2878D-27H020
     Sticker 2:
      (barcode)
      <mac.address> J27H020.00 LF, 4xxxxxx-xxx
     Board:
      U1   76pin atheros ... "ATHEROS, AR6013G-AL1C, N2U586.00C, 1035, KOREA"
      U2    -    -
      U3    -    -
      U4    8pin I2C EEPROM "G80, 8, G02"
      U5    8pin SPI FLASH big chip "26FV032T, OGK01"  (installed)
      U6    -    -
      U7    8pin SPI FLASH small chip (not installed)
      U?    5pin voltage regulator or so "IG19P"
      U?    6pin whatever near antenna (not installed)
      Y1    4pin crystal "H400K"
      J3    2pin Connector for Antenna (shielded white cable)
      J6   50pin Connector to Mainboard

3DS Wifi Daughterboard (DWM-W028)
Component list is unknown. The thing is said to use a "Atheros AR6014" chip.
Later 3DS models have the Wifi unit (with AR6014G chip) on the mainboard (instead of using a removeable DWM board).
DSi Battery/DPAD Daughterboard "C/TWL-SUB-01"

      TH1  2pin  Battery Thermal Sensor maybe? (about 10kOhm at room temperature)
      F1   2pin  Battery Fuse
      SW1  2pin  DPAD Up Button
      SW2  2pin  DPAD Down Button
      SW3  2pin  DPAD Left Button
      SW4  2pin  DPAD Right Button
      SW5  2pin  Power/Reset Button
      P1  15pin  To Mainboard (P15) (button/led signals) (wire "15P-01")
      P2   6pin  To 3xLEDs
      P3   3pin  To battery (TWL-003 3.6V 840mAh 3Wh C/TWL-A-BP, Li-ion 00"
      Wire 2pin  To Mainboard (P17) (battery supply) (red=vcc, black=gnd)

DSi LED Board/Foil "LED-01, (DF)"

      D    2pin  Left LED      ;-wifi
      D    2pin  Middle LED    ;-charge
      D    2pin  Right LED 1   ;\power "two-color-LED"
      D    2pin  Right LED 2   ;/composed of 2 single LEDs
      Wire 6pin  To Battery/DPAD Daughterboard

DSi Lower Screen with Touchpad

      Wire 4pin  Touchpad
      Wire 4pin  Backlight (actually 2pins, each 2 pins are same)
      Wire xxpin Video Signals
      LCD  "LS033A1DG48R, 8X16Q U0003986"

DSi Upper Screen with Speakers & Cameras & LED & Microphone

      Orange Ribbon Cable: Video Signals, Backlight, and Speakers
      Black Ribbon Cable: Cameras and Camera LED
      Shielded Orange 2pin Wire: Microphone
      Shielded White 2pin Wire: Wifi PCB Antenna
      LCD  "LS033A1DG38R, BX16Q L0005532"
      The speakers use red/black wires, which connect to the orange ribbon cable

DSi Upper Screen Area Extra Components: Speakers & Cameras & LED & Microphone
DSi Lower Case (SD Slot, L/R and VOL+/- Buttons, and screen calibration)

      Whatever, not checked yet

DSi Disassembly Notes
Bottom Cover Screws:

      7 screws (two are under battery cover)

Remove bottom cover, and:

      P16: To bottom cover (SD Slot and L/R/VOL+/-) --> pull (away from board)

Remove Wifi Daughterboard:

      P5:  Wifi-board (without cable)               --> pull (away from board)
      WHITE: Wifi-Antenna (shielded 2pin)           --> pull (away from wifi-board)

Remove mainboard:

      ORANGE P24 (shielded 2pin)  --> pull (away from board)
      WHITE SUPPLY                --> lift (use screwdriver & push away from board)
      3x bigger white/black connectors --> lift black lid (at cable-side)
      2x smaller black connectors      --> lift black lid (at cable-end) (!!!)

Turn mainboard over, then unlock the connector at back side:

      1x bigger white/black connector  --> lift black lid (at cable-side)

Remove Battery board:

      1x smaller black connector       --> lift black lid (at cable-end) (!!!)
      1x bigger white/black connectors --> lift black lid (at cable-side)
      (don't disconnect bigger connector if the other cable end is already
      disconnected from mainboard) (or if you did do, reassemble as follows:
      longer cable end to battery board, short cable end to mainboard)
      1x battery cable (disconnect at mainboard side, see there)

Top Cover Disassembly:

      Disconnect upper LCD and mic/antenna from mainboard (see above)
      Remove 4 screws (all hidden under square rubber pieces)
      slide rear bezel upwards by two millimeters?
      push metal hinge inwards by three millimeters (under LED unit)

AUX DSi Internal Connectors

P1 - 19pin - NDS/DSi cartridge slot (17pin slot + 2pin switch at right side)

      1   GND
      2   MC1_CLK
      3   -
      4   MC1_CS
      5   MC1_RES
      6   MC1_CS2
      7   MC1_IREQ
      8   MC1_VDD via Q6 to VDD33 (cpu signal preamplified from Q7)
      9   MC1_IO0
      10  MC1_IO1
      11  MC1_IO2
      12  MC1_IO3
      13  MC1_IO4
      14  MC1_IO5
      15  MC1_IO6
      16  MC1_IO7
      17  GND
      18  MC1_DET           ;\switch closed when cart inserted
      19  GND               ;/
      Shield GND

P4 - 8pin - External microphone/headphone combo socket

      1  GND    ;\      ;\
      2  SL     ; head- ; headphone gnd/left/right
      3  SR     ; phone ;/
      4  GND    ;       ;\headphone/speaker switch (pin 4+5 shortcut with each
      5  HP#SP  ;/      ;/other when no headphone connected)
      6  MIC    ;\    ;\microphone switch (pin6+7 shortcut when no mic connected)
      7  Switch ; mic ;/(internal mic from P23 is then passed from pin7 to pin6)
      8  GND    ;/

P5 - 50pin - DSi Wifi-Daughterboard (DWM-W015, DWM-W024, or J27H020)

                               GND   2  1   SDIO.CLK       ;\
                             VDD18   4  3   GND            ; SDIO for
                             VDD18   6  5   SDIO.DAT0      ; Atheros Wifi
                               GND   8  7   SDIO.DAT3      ; (CLK, CMD, DATA0-3)
                             VDD33  10  9   SDIO.DAT1      ;
                             VDD33  12  11  SDIO.CMD       ;
                               GND  14  13  SDIO.DAT2      ;/
                          ATH_TX_H  16  15  DSi: NC (DWM: JTAG_TDO)
                         /WIFI_RST  18  17  DSi: NC (DWM: JTAG_TMS)
         (DWM:JTAG_TDI)    DSi: NC  20  19  GND
         (DWM:JTAG_TCK)    DSi: NC  22  21  RTC_FOUT (or RTC_F32K?)  ;for Atheros?
         (DWM:JTAG_TRST_L) DSi: NC  24  23  GND
     (near CPU irq pins) SEL_ATH_L  26  25  DSi: NC (wifi: via 0 ohm MM3218.pin47)
                   /FLASH_WP (R122) 28  27  SPI_CS2 (wifi FLASH memory)
                           SPI_SCK  30  29  BBP_SLEEP    to MM3218.pin42
                          SPI_MISO  32  31  RF_SLEEP     to MM3218.pin41
                          SPI_MOSI  34  33  RF_SCS       to MM3218.pin38
           to MM3218.pin15     CCA  36  35  BBP_SCS      to MM3218.pin37
                           WL_RXPE  38  37  BB_RF_SDO    to MM3218.pin36
           to MM3218.pin19  TRDATA  40  39  BB_RF_SDI    to MM3218.pin35
                               GND  42  41  BB_RF_SCLK   to MM3218.pin34
           to MM3218.pin21   TRCLK  44  43  NC(VDD18_TP) to MM3218.pin28 (0ohm+cap)
           to MM3218.pin18   TRRDY  46  45  GND
                           WL_TXPE  48  47  MCLK    to MM3218.pin23 (via XX & CLxx)
                             RESET  50  49  GND

https://fccid.io/EW4DWMW024/Label/Label-format-and-location-1137926.pdf
https://fccid.io/EW4DWMW015/Label/Label-Location-1031953.pdf
Pin 25 and 43 are VDD test points on DWM-W015 wifiboard (but are NC on DSi mainboard & DWM-W024 wifiboard).
P7 - 47pin - To UPPER lcd screen (video+backlight+speakers) (on PCB backside)

                              BLA2   1  2   BLC2    ;-backlight
                              SPLN   3  4   SPLN    ;\left speaker
                              SPLP   5  6   SPLP    ;/
                              SPRN   7  8   SPRN    ;\right speaker
                              SPRP   9  10  SPRP    ;/
                             VDD-5  11  12  VDD10
                              VDD5  13  14  GND
                              VSHD  15  16  VSHD
                               INI  17  18  GSP
                               GCK  19  20  LDB20
                             LDB21  21  22  LDB22
                             LDB23  23  24  LDB24
                             LDB25  25  26  LDG20
                             LDG21  27  28  LDG22
                               GND  29  30  LDG23
                             LDG24  31  32  LDG25
                             LDR20  33  34  LDR21
                             LDR22  35  36  LDR23
                             LDR24  37  38  LDR25
                               GND  39  40  DCLK
                               SPL  41  42  LS
                               GND  43  44  via C79 to COM2
                               REV  45  46  GND
                              COM2  47

P8 - 37pin - To LOWER lcd screen (video signals)

                             VDD-5   1  2   VDD10
                              VDD5   3  4   GND
                              VSHD   5  6   VSHD
                               INI   7  8   GSP
                               GCK   9  10  LDB10
                             LDB11  11  12  LDB12
                             LDB13  13  14  LDB14
                             LDB15  15  16  LDG10
                             LDG11  17  18  LDG12
                               GND  19  20  LDG13
                             LDG14  21  22  LDG15
                             LDR10  23  24  LDR11
                             LDR12  25  26  LDR13
                             LDR14  27  28  LDR15
                               GND  29  30  DCLK
                               SPL  31  32  LS
                               GND  33  34  via C93 to COM1
                               REV  35  36  GND
                              COM1  37

P9 - 25pin - To UPPER lcd screen (signals for both cameras, and camera led)

                               GND   1  2   CAM_LED
                             VDD42   3  4   GND
                      R100    RCLK   5  6   GND
                               GND   7  8   HSYNC
                             VSYNC   9  10  CAM_D5  RA7
                       RA7  CAM_D6  11  12  CAM_D4  RA7
                           CAM_RST  13  14  SCL
                               SDA  15  16  CAM_D7  RA7
                       RA6  CAM_D0  17  18  CAM_D3  RA6
                       RA6  CAM_D1  19  20  CAM_D2  RA6
                             VDD28  21  22  GND
                               CKI  23  24  GND
                             VDD18  25

P10 - 4pin - To LOWER lcd screen (touchpad X-,Y-,X+,Y+)

      1 X-
      2 Y-
      3 X+
      4 Y+

P11 2pin External Power Supply input (4.6V DC IN)

      1 VIN  (+4.6V)
      2 VGND (GND)
      Shield (GND)

P15 - 15pin - To battery/DPAD/PowerButton board (and onwards to 3xLEDs)

      dpad up button      P06  1  2  ORANGE (LED) Battery Charge
      dpad right button   P04  3  4  BLUE   (LED) Power On/Good
      dpad left button    P05  5  6  YELLOW (LED) Wifi
      dpad down button    P07  7  8  RED    (LED) Power On/Low
                          GND  9  10 VDD42 (to LEDs)
                          GND 11  12 TH on DPAD board (via R102 to TH on main)
      middle battery pin  DET 13  14 GND
      power button       PWSW 15

Note: On Daughterboard, pins are mirrored (eg. PWSW=Pin1 instead Pin15)
P16 - 26pin - To bottom cover (SD Slot and L/R/VOL+/- buttons)

                          GND  2  1  SD10_CLK                   ;\
                   SD10_DATA0  4  3  SD10_VDD (aka VDD33)       ;
                   SD10_DATA1  6  5  SD10_VDD (aka VDD33)       ; pin 1..18
                      SD10_WP  8  7  GND                        ; to RIGHT side:
                          GND 10  9  SD10_CMD                   ; R-button, and
      shoulder button R   P08 12  11 GND                        ; SD-card slot
                          GND 14  13 SD10_DATA3                 ;
                      SD10_CD 16  15 SD10_DATA2                 ;
                          GND 18  17 GND                        ;/
                          GND 20  19 GND                        ;\pin 19..20
      maybe display ;\   VDD5 22  21 VOLP (aka volume plus?)    ; to LEFT side:
      calibration?  ;    COM1 24  23 VOLN (aka volume minus?)   ; L-button, VOL +/-
      (at battery)  ;/   COM2 26  25 P09   shoulder button L    ;/and calibration

P17 - 2pin - Battery cable (lower-right) ;see text-layer (B)

      + BT+ (plus) (red wire)
      - BT- (GND)  (black wire)

P18 - 4pin - To LOWER lcd screen (backlight cathode/anode)

      1 BLC1  ;\both same
      2 BLC1  ;/
      3 BLA1  ;\both same
      4 BLA1  ;/

P19 - 1pin - Shielding-Plate for CPU (lower clip)
P20 - 1pin - Shielding-Plate for CPU (upper clip)
P21 - 1pin - Shielding-Plate for CPU (right clip)

      Shield GND

P23 - 2pin - To Internal Microphone (via orange shielded wire)

      Pin  MIC (from P4.Pin7, disconnected when external microphone connected)
      Shield GND

DPAD-BOARD - P2 - 6pin - To LEDs

      1  YELLOW  Wifi
      2  BLUE    Power On/Good
      3  ORANGE  Battery Charge
      4  GND   (for red+orange)
      5  RED     Power On/Low
      6  VDD42 (for yellow+blue)

AUX DSi Chipset Pinouts

A photo of the DSi mainboard (with extra text layer on vias and solderpads) can be found at:

      http://problemkaputt.de/twl-core.jpg

DSi U1 - TWL-CPU (19x19 pin grid) (352 pins, aka 19x19 minus middle 3x3 pins)

          Wifi    MC2 maybe      MC1           SD/MMC  eMMC  SPI     RTC   IRQs
      .---.---.---------------.---------------.-------.---.-------.-------.---.---.
      |NC |wif|NC  NC  NC  NC |D7  D3  IRQ CLK|D0  CLK|CLK|CS3 SCK|CS  SCK|R7 |NC |
      +---'   |               |               |       |   |       |   .---'   '---+
      |wif wif|NC  NC  NC  NC |D6  D2  DET CS |D1  CMD|D0 |CS2 MIS|SIO|PEN NC  WIF|
      |       |               |               |       |   |       +---+---.   .---+
      |wif wif|NC  NC  NC  NC |D5  D1  PWR CS2|D2  CD |D1 |CS1 MOS|R00 R01|RTC|P09|
      |       '---.       .---+           .---'   .---'   '---.---+       '---'   |
      |wif wif wif|NC  NC |V33|D4  D0  RES|D3  WP |D3  D2  CMD| ? |P08 P07 P06 P05|
      |           '---+---'   '-----------'-------'-----------'---+               |
      |wif wif RXP TXP|GND V12 V33 GND V12 V33 G?  V12 V33 GND V33|P04 P03 P02 P01|
      | . .           |                                           +-----------.   |
      |DT3|wif wif ?  |GND V33 V12 GND GND GND V33 G?  GND V33 V12| ?  RES NC |P00|
      |   '. . . . . .|                                           |           '---+
      |CLK DT2 DT1 DT0|V33 GND V12 V33 GND V12 G?  V12 GND GND V33|PMO VC5 PMS X  |
      +-----------.   |                                           '-----------.   |
      |V33 NC  GND|CMD|V12 GND V33 GND V12 V33 GND V33 V12 V12 V33 GND GND GND|X  |
      |           '---'               .-----------.               .-----------'   |
      |V33 NC  V33 V33 GND V33 GND V33|-   -   -  |GND GND GND GND|HP# IRQ ?   GND|
      +---.   .---.                   |           |               |               |
      |B15|V33|NC |V33 V12 GND V12 V12|-   -   -  |V12 V18 GND V12|NC  NC  NC  GP |
      |   '---'---'---.               |           |               +---------------+
      |B14 B13 B12 B11|V33 GND V33 GND|-   -   -  |V18 GND V18 GND|A1  D1  A0  D0 |
      |               |               '-----------'               |               |
      |B10 G15 G14 G13|GND V33 V12 GND V18 V12 V18 GND V18 V12 V18|A3  D3  A2  D2 |
      |               |                                           |               |
      |G12 G11 G10 R15|V33 V12 GND V12 GND V18 GND V12 GND V18 GND|A5  D5  A4  D4 |
      |               |                                           |               |
      |R14 R13 R12 R11|GND V33 V18 GND V18 V12 V18 GND V18 V12 V18|A7  D7  A6  D6 |
      +-----------.   |                                           |               |
      |DCK GSP SPL|R10|V33 V12 GND V18 GND V18 GND V12 GND V18 GND|A9  D9  A8  D8 |
      |       .---'---'-------.-------.---.---.-------.-----------'               |
      |LS  REV|B22 G24 G20 R22|D7  D3 |NC |RST|SCK WS |CE1 /OE A20 A11 D11 A10 D10|
      |   .---'               |       |   |   |       |                           |
      |GCK|B25 B21 G23 R25 R21|D6  D2 |NC |VSY|MCK SDO|NC  CE2 A19 A13 D13 A12 D12|
      |   |                   |       |   |   +---.   |                           |
      |INI|B24 B20 G22 R24 R20|D5  D1 |NC |HSY|SDA|SDI|/LB CLK A18 A21 A14 D15 D14|
      +---+               .---+       '---'   |   +---'                       .---+
      |NC |B23 G25 G21 R23|NC |D4  D0  CKI RCK|SCL|/UB ADV /WE A15 A17 A22 A16|NC |
      '---'---------------'---'---------------'---'---------------------------'---'
              LCD                  CAM         I2C SND          RAM               o

DSi U2 - Main RAM (8Mx16) (Fujitsu MB82DBS08164, or NEC uPD46128512)
DSi mainboard solder pads (12x8 grid, within 14x10 grid):

           A    B    C    D    E    F    G    H    J    K    L    M    N    P
      10   -    -    -    -    -    -    -    -    -    -    -    -    -    -
      9    -    NC   NC   -    A15  A21  A22  A16  NC   VSS  -    NC   NC   -
      8    -    NC   NC   A11  A12  A13  A14  NC   DQ15 DQ7  DQ14 NC   NC   -
      7    -    -    -    A8   A19  A9   A10  DQ6  DQ13 DQ12 DQ5  -    -    -
      6    -    -    -    /WE  CE2  A20  -    -    DQ4  VDD  NC   -    -    -
      5    -    -    -    CLK  /ADV (W)  -    -    DQ3  VDD  DQ11 -    -    -
      4    -    -    -    /LB  /UB  A18  A17  DQ1  DQ9  DQ10 DQ2  -    -    -
      3    -    NC   -    A7   A6   A5   A4   VSS  /OE  DQ0  DQ8  NC   NC   -
      2    -    NC   NC   -    A3   A2   A1   A0   NC   /CE1 -    NC   NC   -
      1 o  -    -    -    -    -    -    -    -    -    -    -    -    -    -

DSi RAM - Fujitsu MB82DBS08164 (14x10 grid):

           A    B    C    D    E    F    G    H    J    K    L    M    N    P
      10   NC   NC   NC   NC   NC   NC   VDD  VSS  NC   NC   NC   NC   NC   NC
      9    NC   NC   NC   NC   A15  A21  A22  A16  NC   VSS  NC   NC   NC   NC
      8    -    -    NC   A11  A12  A13  A14  NC   DQ15 DQ7  DQ14 NC   -    -
      7    -    -    NC   A8   A19  A9   A10  DQ6  DQ13 DQ12 DQ5  NC   -    -
      6    -    -    NC   /WE  CE2  A20  NC   NC   DQ4  VDD  NC   NC   -    -
      5    -    -    NC   CLK  /ADV /WAI NC   VDD  DQ3  VDD  DQ11 VDD  -    -
      4    -    -    NC   /LB  /UB  A18  A17  DQ1  DQ9  DQ10 DQ2  VSS  -    -
      3    -    -    VSS  A7   A6   A5   A4   VSS  /OE  DQ0  DQ8  NC   -    -
      2    NC   NC   NC   NC   A3   A2   A1   A0   NC   /CE1 NC   NC   NC   NC
      1 o  NC   NC   -    NC   NC   NC   VDD  VSS  NC   NC   NC   NC   NC   NC

DSi RAM - NEC uPD46128512 (14x10 grid):

           A    B    C    D    E    F    G    H    J    K    L    M    N    P
      10   NC   NC   NC   -    -    -    NC   NC   -    -    -    NC   NC   NC
      9    -    NC   NC   -    A15  A21  A22  A16  NC   VSS  -    NC   NC   -
      8    -    -    NC   A11  A12  A13  A14  NC   DQ15 DQ7  DQ14 NC   -    -
      7    -    -    -    A8   A19  A9   A10  DQ6  DQ13 DQ12 DQ5  -    -    -
      6    -    -    NC   /WE  CE2  A20  NC   NC   DQ4  VCC  NC   NC   -    -
      5    -    -    NC   CLK  /ADV /WAI NC   NC   DQ3  VCC  DQ11 NC   -    -
      4    -    -    -    /LB  /UB  A18  A17  DQ1  DQ9  DQ10 DQ2  -    -    -
      3    -    -    NC   A7   A6   A5   A4   GND  /OE  DQ0  DQ8  NC   -    -
      2    -    NC   NC   NC   A3   A2   A1   A0   NC   /CE1 -    NC   NC   -
      1 o  NC   NC   NC   -    -    -    NC   NC   -    -    -    NC   NC   NC

The Fujitsu & NEC datasheets are specifing 14x10 grid (the chips are essentially pin-compatible, except that: NEC has removed some NC pins, changed some supply pins to NC, and (attempted to) rename VSS to GND).
However, the DSi mainboard has 12x8 grid solder pads (and the installed NEC/Fujitsu chip/packages are actually only 12x8, too).
The DSi debug version is said to have 32Mbyte RAM, there is no provision for that feature on DSi retail boards; dev boards are probably somewhere having an extra address line (or an extra chip select for a 2nd RAM chip).
DSi U3 - Power Managment (Texas Instruments 72071B0, or Mitsumi 3317A)

      1   GND (via CL9)
      2   ADPO
      3   EXTB+
      4   VDD33
      5   RESET         ;\
      6   SPI_SCK       ; main cpu bus
      7   SPI_MOSI      ; (reset and spi)
      8   SPI_MISO      ;
      9   SPI_CS1       ;/  <-- powerman (this does ALSO connect to U4)
      10  GND
      11  PMOFF
      12  PWSWO
      13  VCNT5
      14  PM_SLP
      ---
      15  B+
      16  VDD12 via L1
      17  VDD12
      18  GND
      19  BLC1          ;\
      20  BLA1 via U13  ; backlight 1+2
      21  BLA2 via U14  ; anode/cathode
      22  BLC2          ;/
      23  GND
      24  B+
      25  B+
      26  VDD18 via L2
      27  VDD18 via L2
      28  VDD18
      ---
      29  DET     ;\battery contacts
      30  BT+     ;/    ;\these are almost shortcut
      31  VDET-         ;/with each other (via 0 ohm R71)
      32  PVDD
      33  PWSW (when off: very few ohms to PVDD)
      34        ... via R104 (100K) to Q3 (B+ enable or so?)
      35  B+
      36        ... via to C18 to GND (seems to have no other connection)
      37  GND
      38  AOUT  ;\to U6
      39  GND   ;
      40  SCL1  ;   ;\secondary IC2 bus (to U6)
      41  SDA1  ;/  ;/
      42  VDD33
      ---
      43  GND via CL10
      44  VDD5 input (sense if VDD5/C16 has reached voltage)
      45  charge-pump for VDD5 (L7 and via DA3 to VDD5/C16)
      46  charge-pump for VDD5 (L5 and C14)
      47  VDD33 (via CL5)
      48  VDD33 (via L3)
      49  VDD33
      50  VDD33
      51  B+
      52  B+
      53  B+
      54  charge-pump for VDD42 (L7 and C23)
      55  charge-pump for VDD42 (L7 and via D3 to VDD42/C22)
      56  VDD42 input (sense if VDD42/C22 has reached voltage)

DSi U4 - Sound and Touchscreen controller (AIC3000D)
AIC3000D pinout is same as in TSC2117 datasheet (aside from GPIx/GPIOx pins).

      Pin TSC2117 AIC3000D
      1   MISO    SPI_MISO
      2   MOSI    SPI_MOSI
      3   /SS     SPI_CS1 (powerman, this does ALSO connect to U3)
      4   SCLK    SPI_SCLK
      5   GPIO1   SPI_CS3 (touchscreen)
      6   GPIO2   PENIRQ
      7   IOVSS   GND
      8   IOVDD   VDD33
      9   DVDD    VDD18
      10  SDOUT   SND_SDI              ;\
      11  SDIN    SND_SDO              ;
      12  WLCK    SND_WS               ; serial sound input from main cpu
      ---                              ; (and serial output? microphone maybe?)
      13  BCLK    SND_SCLK             ;
      14  MCLK    SND_MCLK             ;/
      15  SDA       ... via R107 to VDD18  ;\unused I2C bus (?)
      16  SCL       ... via R106 to VDD18  ;/
      17  VOL/M   wiper (sound volume, from I2C potentiometer) "VOL/MICDET?"
      18  MICBIAS   LIN-related-1 ... to 6pin U18
      19  MIC     LIN (aka MIC via C31)
      20  AUX1      LIN-related-2   ;\via 0ohm R108 to ... something on U18
      21  AUX2      LIN-related-2   ;/                     that is almost GND
      22  AVSS    GND
      23  AVDD    VDD33
      24  VBAT    GND
      ---
      25  VREF    VDD33
      26  TSVSS   GND
      27  YN      Y-                   ;\
      28  XN      X-                   ;
      29  DVSS    GND                  ; touchscreen input
      30  YP      Y+                   ;
      31  XP      X+                   ;/
      32  TSVDD   VDD33
      33  SPLN    SPLN                 ;\
      34  SLVSS   GND                  ;
      35  SLVDD   B+                   ; speaker output
      36  SPLP    SPLP                 ;
      ---                              ;
      37  SPRN    SPRN                 ;
      38  SRVDD   B+                   ;
      39  SRVSS   GND                  ;
      40  SPRP    SPRP                 ;/
      41  HPL     SL via CP2 and R88      ;\
      42  HVDD    VDD33                   ;
      43  HVSS    GND                     ; headphone output
      44  HPR     SR via CP3 and R89      ;
      45  GPI3    MUTE via Q4/Q5 to SR/SL ;
      46  GPI2    HP#SP switch            ;/
      47  GPI1    VCNT5
      48  /RESET  RESET

DSi U5 - 256Mbyte eMMC NAND (14x14 grid)

           1    2    3    4    5    6    7    8    9    10   11   12   13   14
      o A  NC   NC   DAT0 DAT1 DAT2 NC   NC   NC   NC   NC   NC   NC   NC   NC
        B  NC   DAT3 DAT4 DAT5 DAT6 DAT7 NC   NC   NC   NC   NC   NC   NC   NC
        C  NC   VDDI NC   VSSQ NC   VCCQ NC   NC   NC   NC   NC   NC   NC   NC
        D  NC   NC   NC   NC   -    -    -    -    -    -    -    NC   NC   NC
        E  NC   NC   NC   -    NC   VCC  VSS  NC   NC   NC   -    NC   NC   NC
        F  NC   NC   NC   -    VCC  -    -    -    -    NC   -    NC   NC   NC
        G  NC   NC   NC   -    VSS  -    -    -    -    NC   -    NC   NC   NC
        H  NC   NC   NC   -    NC   -    -    -    -    VSS  -    NC   NC   NC
        J  NC   NC   NC   -    NC   -    -    -    -    VCC  -    NC   NC   NC
        K  NC   NC   NC   -    NC   NC   NC   VSS  VCC  NC   -    NC   NC   NC
        L  NC   NC   NC   -    -    -    -    -    -    -    -    NC   NC   NC
        M  NC   NC   NC   VCCQ CMD  CLK  NC   NC   NC   NC   NC   NC   NC   NC
        N  NC   VSSQ NC   VCCQ VSSQ NC   NC   NC   NC   NC   NC   NC   NC   NC
        P  NC   NC   VCCQ VSSQ VCCQ VSSQ NC   NC   NC   NC   NC   NC   NC   NC

Note: The pinout follows JEDEC's eMMC standard. The "NC" pins are GNDed in DSi, the "DAT4..DAT7" pins are not connected in DSi. The "VDDI" pin isn't wired to VDD, instead it goes to a capacitor (0.1uF min) "for internal power stability".
DSi U6 - "BPTWL" - I2C bus(ses), LEDs, volume, power, wifi (6x6 grid)

           GND         WL_TXPE     P02(button) SDA'33      ADPO        GND       o
           ATH_TX_H    BLUE(LED)   RED(LED)    SCL'33      V33         GND
           YELLOW(LED) VOLP button VOLN button PM_SLP      V33'        /WIFI_RST
           SDA1        RESET       SCL1        to C46      GND         to U17
           VDD28       GND         CAM_LED     PWSWO       mFE         /mRST
           GND         AOUT        mFE'(R79)   WL_RXPE     /IRQ_O      GND

DSi U7 - I2C bus potentiometer (ISL95810) (Device 50h)

      1  /WP (DSi: VDD33)  writeprotect
      2  SCL (DSi: SCL1)   i2c bus   ;\from U6
      3  SDA (DSi: SDA1)   i2c bus   ;/
      4  GND (DSi: GND)    ground
      5  RW  (DSi: wiper)  pot.wiper ;-to U4
      6  RL  (DSi: VDD18)  pot.L
      7  RH  (DSi: GND)    pot.H
      8  VCC (DSi: VDD33)  supply

DSi U8 - bidirectional I2C voltage translator (PCA9306)

      1  GND   (DSi: GND)
      2  VREF1 (DSi: VDD18)
      3  SCL1  (DSi: SCL)     ;\to U1 (CPU)
      4  SDA1  (DSi: SDA)     ;/
      5  SDA2  (DSi: SDA'33)  ;\to U6 (LED/stuff)
      6  SCL2  (DSi: SCL'33)  ;/
      7  VREF2 (DSi: VDD33)
      8  EN    (DSi: VDD33)

DSi U9 - RTC - Seiko S-35199A01 (4x3 grid)

           A    B    C    D
      3    CS   /SCK VDD  F32K
      2    SIO  CTRL /INT FOUT
      1 o  VSS  XIN  XOUT VDDL

DSi U10 - Magnet Sensor (for hinge, aka shell opened/closed)

      1  VDD33
      2  R7 (HINGE)  ;to U1
      3  GND
      4  GND

DSi U11 - charge

      1  EXTB+
      2  Rosc
      3  ORANGE (via R2)              ;-charge LED
      4  GND
      5  TH' (via R76 to TH)          ;\thermal sensor
      6  TH  (via R102 to DPAD board) ;/for battery?
      7  B+  (?)
      8  RICHG
      9  BT+
      10 BT+

Note: Seems to resemble Mitsumi MM3358 datasheet.
DSi U12 - 5pin, VDD33 to VDD28 converter? (near upper screen socket)
DSi U13 - 5pin, Backlight 1, near power managment chip
DSi U14 - 5pin, Backlight 2, near power managment chip
DSi U15 - 4pin, something near external power input
DSi U16 - N/A
DSi U17 - 6pin, something near headphone socket, connects to U6, and MUTE
DSi U18 - 6pin, something near headphone socket, MIC/LIN related
DSi U19 - 5pin, something near dpad socket
Smaller misc chips.
DSi LEDs:

      CAM_LED (via R68 and Q13)  ;\
      BLUE    (via R21 and Q11)  ; from U6
      YELLOW  (via R22 and Q12)  ;/
      RED     (via R20)          ;-from U6 (or to U6 ?)
      ORANGE  (via R2)           ;-from U11

DSi Wifi Daughterboard - MM3218 chip (same chip as in DS Lite)

      1  VDD18
      2  GND
      3  VDD18
      4  Antenna signal
      5  Antenna shield
      6  VDD18
      7  VDD18
      8  GND
      9  NC
      10 GND
      11 GND
      12 GND
      13 NC
      14 /RESET
      ---
      15 CCA    ... to DSi mainboard connector pin 36
      16 WL_TXPE
      17 WL_RXPE
      18 TRRDY  ... to DSi mainboard connector pin 46 !!!
      19 TRDATA ... to DSi mainboard connector pin 40
      20 VDD33
      21 TRCLK  ... to DSi mainboard connector pin 44
      22 GND
      23 MCLK   ... via nearby big component ... to DSi mainboard connector pin 47
      24 VDD18
      25 NC
      26 22MHz
      27 22MHz'
      28 ... to DSi mainboard connector pin 43 NC? (with cap to GND and via 0 ohm)
      ---
      29 VDD33
      30 via capacitor to VDD33
      31 via 1K2 + 120K to GND (aka via 121.2K to GND)
      32 VDD18
      33 VDD18
      34 BB_RF_SCLK   ... to DSi mainboard connector pin 41
      35 BB_RF_SDI    ... to DSi mainboard connector pin 39
      36 BB_RF_SDO    ... to DSi mainboard connector pin 37
      37 BBP_SCS      ... to DSi mainboard connector pin 35
      38 RF_SCS       ... to DSi mainboard connector pin 33
      39 GND
      40 VDD33
      41 RF_SLEEP     ... to DSi mainboard connector pin 31
      42 BBP_SLEEP    ... to DSi mainboard connector pin 29
      ---
      43 VDD18
      44 ... shortcut to MM3218.pin50, and via resistor to MM3218.pin46
      45 VDD33
      46 ... via resistor to MM3218.pin44+50
      47 ... to DSi mainboard connector pin 25 (via 0 ohm) (+cap) (NC in DSi)
      48 VDD33
      49 GND
      50 ... shortcut to MM3218.pin44, and via resistor to MM3218.pin46
      51 ... via resistor to GND
      52 VDD18
      53 NC
      54 NC
      55 NC
      56 NC

DSi DWM-W015 Wifi Daughterboard - ROCm Atheros AR6002G-AC1B chip

       1     2     3     4     5     6     7    8    9     10    11    12    13
     A AGND  RF2   RF2   RF2   RF2   PDET  NC   NC   VDD18 VDD12 XTAL  XTAL  BT_CLK
             OUTN  OUTP  INP   INN                   BIAS  XTAL  I     O     OUT
     B RF5   AGND  VDD18 VDD12 VDD12 BIAS  NC   NC   VDD12 VDD12 VDD18 BT_   DVDD12
       INP         FE    LNA   BIAS  REF             D_SYN BB    XTAL  CLKEN
     C RF5   VDD12 -     -     AGND  AGND  AGND AGND AGND  -     -     GPIO  GPIO
       INN   FE                                                        17    16
     D PA5   NC    -     -     -     -     -    -    -     -     -     GPIO  GPIO
       BIAS                                                            14    15
     E RF5   VDD18 AGND  -     AGND  AGND  AGND AGND DVSS  -     -     DVDD  DVDD
       OUT   VCO                                                       GPIO1 GPIO0
     F VDD12 VDD12 AGND  -     AGND  AGND  AGND AGND DVSS  -     DVSS  GPIO  GPIO
       TX5   SYNTH                                                     12    13
     G XPA   XPA   AGND  -     AGND  AGND  AGND AGND DVSS  -     DVSS  GPIO  GPIIO
       BIAS2 BIAS5                                                     10    11
     H VCCFE LDO_  AGND  -     AGND  AGND  AGND AGND DVSS  -     DVSS  GPIO  DVDD
       M     OUT                                                       9     12
     J ANTA  VDDIO AGND  -     DVSS  DVSS  DVSS DVSS DVSS  -     DVSS  CLK_  DVDD
             ANT                                                       REQ   12
     K ANTC  ANTB  -     -     -     -     -    -    -     -     -     SYS_  CHIP_
                                                                       RST_L PWD_L
     L ANTD  ANTE  -     -     DVSS  DVSS  DVSS  DVSS DVSS -     -     DVDD  DVDD_
                                                                       12    SDIO
     M AGND  GPIO0 GPIO2 DVDD  GPIO4 GPIO6 GPIO8 JTAG JTAG JTAG  SDIO_ SDIO_ SDIO_
                         12                      TMS  TCK  TDO   DATA3 DATA2 CLK
     N DVDD  GPIO1 GPIO3 DVDD_ GPIO5 GPIO7 DVDD_ DVDD JTAG DVDD_ SDIO_ SDIO_ SDIO_
       12                BT                SDIO  12   TDI  SDIO  CMD   DATA1 DATA0

DSi DWM-W024 Wifi Daughterboard - Atheros AR6013 chip

      1  1.2V
      2  VDD18
      3  NC
      4  NC
      5  VDD18
      6  NC
      7  1.2V
      8  VDD18
      9  1.2V
      10 NC
      11 NC (except, wired to tespoint)
      12 VDD33
      13 via 0 ohm to ATH_TX_H  ;<--with 0 ohm connection
      14 via (N/A) to ATH_TX_H  ;<--connection not installed
      15 to a dead-end-via
      16 to a dead-end-via
      17 1.2V
      18 P5.pin24       JTAG_TRST_L     (plus testpoint)
      19 NC (except, wired to tespoint)
      ---
      20 VDD18
      21 1.2V
      22 I2C.SCL
      23 I2C.SDA
      24 P5.pin21 RTC 32KHZ via 0 ohm
      25 /WIFI_RST
      26 ATH_TX_H
      27 SDKI.CMD
      28 SDIO.CLK
      29 VDD33
      30 SDIO.DAT0
      31 SDIO.DAT2
      32 SDIO.DAT1
      33 SDIO.DAT3
      34 P5.pin22       JTAG_TCK
      35 P5.pin20       JTAG_TDI
      36 P5.pin17       JTAG_TMS
      37 1.2V
      38 P5.pin15       JTAG_TDO
      ---
      39 P5.pin36       CCA
      40 VDD33
      41 1.2V
      42 P5.pin46       TRRDY
      43 P5.pin44       TRCLK
      44 P5.pin40       TRDATA
      45 WL_TXPE
      46 WL_RXPE
      47 P5.pin47       MCLK
      48 P5.pin33       RF_SCS      ... and 6.9ohm to P5.47 ?
      49 P5.pin35       BBP_SCS
      50 P5.pin39       BB_RF_SDI
      51 VDD33
      52 P5.pin37       BB_RF_SDO
      53 P5.pin41       BB_RF_SCLK
      54 P5.pin29       BBP_SLEEP
      55 P5.pin31       RF_SLEEP
      56 P5.pin26       SEL_ATH_L   ... IRQ?
      57 1.2V
      ---
      58 VDD18
      59 XTALx
      60 XTALx
      61 1.2V
      62 1.2V
      63 VDD18
      64 NC (except, wired to tespoint)
      65 NC (except, wired to tespoint)
      66 NC (except, wired to tespoint)
      67 NC (except, wired to tespoint)
      68 NC
      69 via 6.1K to GND
      70 1.2V
      71 NC
      72 NC
      73 VDD18
      74 RF2.OUTx
      75 RF2.OUTx
      76 VDD18
      ---
      GND center plates

Note: /RESET connects to Wifi FLASH only, ie. NOT to the MM3218 clone within AR6013G (that's unlike as real MM3218).
3DS DWM-W028 Wifi Daughterboard - Atheros AR6014 chip
Pinouts unknown.
There is a 3rd part number, J27H020, made by hon hai (Foxconn) instead of Mitsumi.

Pinouts - CPU - Signal Summary

Advance Gameboy CPU Signal Summary
Cart Bus: D0-D7, A0-A15, /CS, /RD, /WR (different usage in GBA/DMG mode)
WRAM Bus: WA0-WA16, WD0-WD15, /WLB, /WUB, /WWE, /WOE (used in GBA mode only)
LCD Bus : LDR1-5, LDG1-5, LDB1-5, DCK, LP, PS, SPL, CLS, SPS, MOD, REVC
Joypad: TP0-3 (Buttons), TP4-7 (Directions), TP8-9 (L/R-Buttons, via R43/R44)
Serial Link: SC, SD (aka P14?), SI, SO - Audio: SO1-2, Vin
Other: CK1-2, PHI, IN35, VCNT5, /FIQ (via CL1 to VDD3), /RESET (IN), /RES (OUT)
Supply: VDD35, VDD3, VDD2, GND (some are probably undoc inputs)
GBA SP: Same as GBA, plus VDD1, plus duplicated supply pins, plus pin 152.

Pinouts - CPU - Pinouts

Advance Gameboy CPU Pinouts (CPU AGB)

      1 VDD3  17 D0   33 A0    49 WA4   65 VDD2  81 WD9   97 LDB5   113 CK1
      2 IN35  18 A15  34 /CS   50 WA5   66 WD5   82 WD1   98 LDB4   114 CK2
      3 TP8   19 A14  35 /RD   51 WA6   67 WD13  83 /WOE  99 LDB3   115 VDD2
      4 TP0   20 A13  36 /WR   52 WA7   68 WD6   84 DCK   100 LDB2  116 GND
      5 TP1   21 A12  37 PHI   53 /WLB  69 WD14  85 LP    101 LDB1  117 VDD2
      6 SO1   22 A11  38 VDD35 54 /WUB  70 WD7   86 PS    102 GND   118 VCNT5
      7 SO2   23 A10  39 GND   55 /WWE  71 WD15  87 LDR5  103 VDD3  119 TP9
      8 Vin   24 A9   40 SC    56 WA8   72 WD8   88 LDR4  104 SPL   120 TP6
      9 /RES  25 A8   41 SD    57 WA9   73 WD16  89 LDR3  105 CLS   121 TP5
      10 D7   26 A7   42 SI    58 WA10  74 WA16  90 LDR2  106 SPS   122 TP7
      11 D6   27 A6   43 SO    59 WA11  75 WD12  91 LDR1  107 MOD   123 TP4
      12 D5   28 A5   44 VDD2  60 WA12  76 WD4   92 LDG5  108 REVC  124 /FIQ
      13 D4   29 A4   45 WA0   61 WA13  77 WD11  93 LDG4  109 GNDed 125 /RESET
      14 D3   30 A3   46 WA1   62 WA14  78 WD3   94 LDG3  110 GNDed 126 TP2
      15 D2   31 A2   47 WA2   63 WA15  79 WD10  95 LDG2  111 GNDed 127 TP3
      16 D1   32 A1   48 WA3   64 GND   80 WD2   96 LDG1  112 GNDed 128 GND

GBA SP CPU Pinouts (CPU AGB B)

      1 IN35   21 D0    41 A0    61 WA4   81 WD13  101 GND   121 LDB4  141 GND
      2 TP8    22 A15   42 /CS   62 WA5   82 WD6   102 VDD1  122 LDB3  142 VDD3
      3 TP0    23 A14   43 /RD   63 WA6   83 WD14  103 GND   123 LDB2  143 GND
      4 TP1    24 A13   44 /WR   64 WA7   84 WD7   104 VDD3  124 LDB1  144 VCNT5
      5 SO1    25 A12   45 PHI   65 /WLB  85 WD15  105 DCK   125 GND   145 TP9
      6 SO2    26 A11   46 VDD35 66 /WUB  86 WD8   106 LP    126 VDD3  146 TP6
      7 Vin    27 GND   47 GND   67 GND   87 WD16  107 PS    127 SPL   147 TP5
      8 VDD1   28 VDD35 48 SC    68 VDD2  88 WA16  108 LDR5  128 CLS   148 TP7
      9 GND    29 A10   49 SD    69 /WWE  89 VDD2  109 LDR4  129 SPS   149 TP4
      10 VDD35 30 A9    50 SI    70 WA8   90 GND   110 LDR3  130 MOD   150 /FIQ
      11 /RES  31 A8    51 SO    71 WA9   91 WD12  111 LDR2  131 REVC  151 /RESET
      12 D7    32 A7    52 VDD35 72 WA10  92 WD4   112 LDR1  132 GND   152 ?
      13 D6    33 A6    53 GND   73 WA11  93 WD11  113 LDG5  133 GND   153 TP3
      14 D5    34 A5    54 VDD1  74 WA12  94 WD3   114 LDG4  134 GND   154 TP2
      15 D4    35 A4    55 GND   75 WA13  95 WD10  115 LDG3  135 GND   155 VDD3
      16 D3    36 GND   56 VDD2  76 WA14  96 WD2   116 LDG2  136 VDD1  156 GND
      17 D2    37 VDD35 57 WA0   77 WA15  97 WD9   117 LDG1  137 GND
      18 GND   38 A3    58 WA1   78 GND   98 WD1   118 GND   138 CK1
      19 VDD35 39 A2    59 WA2   79 VDD2  99 /WOE  119 VDD3  139 CK2
      20 D1    40 A1    60 WA3   80 WD5   100 VDD2 120 LDB5  140 VDD2

Pin 152 seems to be not connected on the mainboard, maybe an undoc output.
GBA-Micro, NDS, NDS-Lite, and DSi CPU Pinouts
Unknown. The CPU Pins are hidden underneath of the CPU. And, in NDS and NDS-Lite, the CPU itself hides underneath of the DS Cartridge Slot. In the DSi it's hidden underneath of a shielding plate (which is itself underneath of the removeable wifi daughterboard).

Pinouts - Audio Amplifiers

Advance Gameboy Audio Amplifier (AMP AGB IR3R60N) (U6)

      1   2   3   4   5   6   7   8   9   10  11  12   13   14   15   16   17  18
      C38 FR1 FR2 FL1 FL2 GND RIN LIN C39 VOL SW  VDD5 LOUT VCC3 ROUT VCC3 SP  GND

SW=Headphone Switch (grounded when none connected).
GBA SP Audio Amplifier (uses AMB AGB IR3R60N, too) (U3)
Same connection as in GBA, except that pin14/16 connect to VR21 (instead VCC3), and pin1/9 connect to different capacitors.
NDS - National Semiconductor LM4880M Dual 250mW Audio Power Amplifier (U12)

      1-OUT A  2-IN A  3-BYPASS  4-GND  5-SHUTDOWN  6-IN B  7-OUT A  8-VDD.VQ5

NDS-Lite: No external amplifier (Mitsumi 3205B Powermanagment Device contains internal amplifier).

Pinouts - LCD Cables

Advance Gameboy Display Socket

      1 ?     6 GND    11 LDR2   16 LDG2   21 LDB3   26 SPS     31 P2-VSS  36 V4
      2 VSHD  7 VSHD   12 LDR1   17 LDG1   22 LDB2   27 ?       32 P2-VCC  37 V3
      3 DCK   8 LDR5   13 LDG5   18 GND    23 LDB1   28 MOD     33 ?       38 V2
      4 LP    9 LDR4   14 LDG4   19 LDB5   24 SPL    29 VCOM    34 VDD5    39 V1
      5 PS    10 LDR3  15 LDG3   20 LDB4   25 CLS    30 P2-VEE  35 GND     40 V0

GBA SP Display Socket

      1 VSHD 5 VSHD  9 LDR3   13 LDG4  17 GND   21 LDB2  25 SPS   29 P2VSS 33 U83
      2 DCK  6 GND   10 LDR2  14 LDG3  18 LDB5  22 LDB1  26 MOD   30 COM   34 VDD5
      3 LP   7 LDR5  11 LDR1  15 LDG2  19 LDB4  23 SPL   27 REVC  31 VDD5
      4 PS   8 LDR4  12 LDG5  16 LDG1  20 LDB3  24 CLS   28 P2VDD 32 GND

GBA Micro Display Sockets

      __GBA Mirco display socket (P1)____________________________________
      1-PS    6-5bit  11-MD    16-5bit  21-5bit  26-CL             31-GND
      2-RV    7-5bit  12-SL    17-5bit  22-5bit  27-SS             32-GND
      3-GND   8-5bit  13-CK    18-5bit  23-5bit  28-via C5 to VR1  33-V10
      4-5bit  9-LP    14-GND   19-5bit  24-5bit  29-V5             34-V-5
      5-5bit  10-VD   15-5bit  20-GND   25-5bit  30-to VR1
      __GBA Mirco backlight socket (P3)__________________________________
      1-LC  2-LC  3-LA  4-LA

NDS Upper/Lower Display Sockets

      ___NDS upper screen/upper backlight/speakers socket (P3)_____________________
      1-SPLO 7-PS2   13-LDR2  19-GND   25-LDG2  31-LDB2  37-MOD2  43-VDD15  49-SPRO
      2-SPLO 8-REV2  14-LDR1  20-DCLK2 26-LDG1  32-LDB1  38-GND   44-VDD-5  50-GND
      3-SSC2 9-GND   15-LDR0  21-GND   27-LDG0  33-LDB0  39-VDD5  45-VDD-10 51-GND
      4-ASC2 10-LDR5 16-LS2   22-LDG5  28-LDB5  34-GCK2  40-VDD10 46-LEDC2
      5-GND  11-LDR4 17-VSHD  23-LDG4  29-LDB4  35-GSP2  41-COM2  47-LEDA2
      6-SPL2 12-LDR3 18-DISP1 24-LDG3  30-LDB3  36-GND   42-GND   48-SPRO
      ___NDS lower screen socket (P4)______________________________________________
      1-SSC1 6-REV1  11-LDR2  16-DISP0 21-LDG4  26-LDB5  31-LDB0  36-GND  41-VDD15
      2-ASC1 7-GND   12-LDR1  17-SPL1  22-LDG3  27-LDB4  32-GCK1  37-?    42-VDD10
      3-GND  8-LDR5  13-LDR0  18-DCLK1 23-LDG2  28-LDB3  33-GSP1  38-VDD5 43-GND
      4-?    9-LDR4  14-LS1   19-GND   24-LDG1  29-LDB2  34-VSHD  39-COM1 44-VDD-5
      5-PS1  10-LDR3 15-VSHD  20-LDG5  25-LDG0  30-LDB1  35-MOD1  40-GND  45-VDD-10
      ___NDS lower backlight socket (P5)____   ___NDS touchscreen socket (P6)______
      1:LEDA1  2:LEDA1  3:LEDC1  4:LEDC1       1:Y-    2:X-    3:Y+    4:X+

NDS-Lite Upper/Lower Display Sockets

      ___NDS-Lite upper screen/upper backlight/speakers socket (P3)________________
      1-VDD-5 6-MOD    11-LD2xx 16-LD2xx 21-LD2xx 26-LD2xx 31-LS   36-GND   41-SPRO
      2-VDD10 7-GSP    12-LD2xx 17-LD2xx 22-LD2xx 27-LD2xx 32-VSHD 37-COM2  42-SG
      3-VDD5  8-GCK    13-LD2xx 18-GND   23-LD2xx 28-GND   33-GND  38-LEDA2 43-SG
      4-GND   9-LD2xx  14-LD2xx 19-LD2xx 24-LD2xx 29-DCLK  34-xx2? 39-LEDC2 44-SPLO
      5-VSHD  10-LD2xx 15-LD2xx 20-LD2xx 25-LD2xx 30-SPL   35-REV  40-SPRO  45-SPLO
      ___NDS-Lite lower screen/lower backlight (P4)________________________________
      1-VDD-5 6-MOD    11-LD1xx 16-LD1xx 21-LD1xx 26-LD1xx 31-LS   36-GND
      2-VDD10 7-GSP    12-LD1xx 17-LD1xx 22-LD1xx 27-LD1xx 32-VSHD 37-COM1
      3-VDD5  8-GCK    13-LD1xx 18-GND   23-LD1xx 28-GND   33-GND  38-LEDA1
      4-GND   9-LD1xx  14-LD1xx 19-LD1xx 24-LD1xx 29-DCLK  34-xx1? 39-LEDC1
      5-VSHD  10-LD1xx 15-LD1xx 20-LD1xx 25-LD1xx 30-SPL   35-REV
      ___NDS-Lite touchscreen socket (P6)______   ___NDS-Lite white coax (P12)_____
      1:X-  2:Y-  3:X+  4:Y+                      Center:MICIN  Shield:GND

Pinouts - Power Switches, DC/DC Converters, Reset Generators

Advance Gameboy Power Switch (2-position slider, with two common pins)
GBA SP Power Switch (same as GBA)

      1 via resistor to GND (OFF)
      2 VS (BT+) (ON)
      C VCC (to board)

GBA Micro Power Switch
Same as GBA and GBA SP, but Pin 1 and 2 exchanged.
Advance Gameboy Cartridge Slot Switch (integrated 4pin micro switch)
GBA SP Cartridge Slot Switch (separate 4pin micro switch)

      C1 VDD35  (to S2 when PRESSED, to S1 when RELEASED)
      S1 VDD3   (to C2 when PRESSED, to C1 when RELEASED)
      C2 IN35   (to S1 when PRESSED)
      S2 VDD5   (to C1 when PRESSED)

Pressed=8bit DMG/MGB/CGB cart, Released=32bit GBA cart (or no cart inserted)
GBA: switch integrated in cart socket, GBA-SP: separate switch next to socket.
Advance Gameboy Power Controller (M 121 514X) (U4)

      1-VIN    2-VOUT5  3-CSS5    4-VDRV5  5-GND    6-VDRV3    7-CSS3    8-VOUT3
      9-VCNT5  10-CSCP  11-REGEXT 12-VDD3  13-VDD2  14-/RESET  15-LOWBAT 16-VDD13

/RESET is passed to the CPU, and then forwarded to /RES pin on cart slot.
Advance Gameboy LCD Regulator (AGB-REG IR3E09N) (U3)

      1  2  3    4      5   6   7   8   9   10   11  12  13  14  15  16   17     18
      ?  ?  REVC U3-COM V0  V1  ?   ?   ?   GND  ?   V2  ?   V3  V4  VDD5 U3-VDD ?

GBA SP Power Controller 1 (S6403 AU227 9276) (U4)

      1-VCC    2-SCP1   3-SCP2 4-VDRV3 5-VOUT3/VDD3 6-VDD2  7-VOUT1/VDD1  8-VDRV1
      9-LOWBAT 10-VCNT5 11-LS5 12-?    13-GND       14-?    15-VOUT5/VDD5 16-VDRV5

GBA SP Power Controller 2 (2253B 2808) (U5)

      1-TIN     2-U5C3     3-ADJ  4-U5VDD  5-VIN   6-?    7-U57  8-?
      9-to-C29  10-to-C30  11-?   12-GND   13-VS   14-S-  15-S+  16-U5OUT

GBA Micro - Power Managment Device (U2)

     1 via C43 to GND
     2 via R24 to C34 to R25 back to U2.2
     3 via C35 to GND
     4 via C36 to GND
     5
     6 audio.in ? (see BP)
     7   via C48 to GND
     8   via R21 to C46 to C47 to C38 to R23 to phones
     9  VL (to U4)
     10  via R27 to C33 to C44 to C49 to R22 to phones
     11  via C45 to GND
     12 audio.in ? (see BP)
     13  via C41 to GND
     14 phones (switch)
     15 phones (tip via R22)
     16 phones (mid via R23)
     17 VCS
     18 SP
     19 GND
     20 LB
     21 via C52 to GND
     22 via C53 to GND
     23 RS         (looks like RESET output)
     24 to R37/C56 (looks like RESET input)
     25
     26
     27 via C54 to V3
     28 V3
     29 GND
     30 V3
     31 VC
     32 to C58
     33 to R41/C58
     34 GND
     35
     36 VC
     37 VC
     38
     39 V5
     40 GND
     41 GND
     42
     43
     44
     45 B+
     46 S-
     47 S+
     48

GBA Micro - Volume/Backlight Level Up/Down Controller (U5)

      1-     5-GND  9-      13-XD      17-     21-     25-    29-
      2-     6-GND  10-     14-to U4.7 18-XR   22-CN   26-    30-
      3-     7-     11-XC   15-        19-V+   23-CNS  27-    31-BP
      4-LN   8-     12-GND  16-        20-V-   24-     28-V3  32-

NDS Powermanagment Device (Mitsumi 3152A) (U3)

      1 R50-EXTB+        17               33 LEDC1           49 VCNT5
      2 R39-ORANGE       18               34 GND             50
      3 GND              19 VQ5           35 LEDC2           51 RST
      4                  20               36                 52
      5 Rxx-Q4           21               37 U10-LEDA2       53
      6 INS+             22 GND           38                 54
      7 INS-             23 VQ5           39 MIC.C53-AIN     55 VQ5
      8                  24               40 MIC.TSC.AUX     56 R24-SR
      9 VDET             25 VDD3.3        41 GND             57
      10 PVDD            26 GND           42 R38-RED         58 R22-SL
      11                 27 CL60-VDD3.3   43 R37-GREEN       59 GND
      12 PWSW            28 VSHD          44 VDD3.3          60 VR3.PIN2
      13                 29               45 PWM.SPI.CLK     61
      14 GND             30 VDD5          46 PWM.SPI.D       62
      15 GND             31 U9-LEDA1      47 PWM.SPI.Q       63
      16 VQ5             32               48 PWM.SPI.SEL     64 GND

NDS-LITE Powermanagment Device (Mitsumi 3205B) (U3)

      1 SW               17               33 LEDC1           49 VCNT5
      2 R50-EXTB+        18               34 GND             50
      3 R39-ORANGE       19 VQ5           35 LEDC2           51 RST
      4 GND              20               36                 52
      5                  21               37 U10-LEDA2       53
      6 R30-Q4           22 GND           38                 54
      7 INS+             23 VQ5           39 MIC.C53-AIN     55 CL63-VQ5
      8 INS-             24               40 MIC.TSC.AUX     56 R24-SR
      9 VDET             25 VDD3.3        41 GND             57 SPRO
      10 PVDD            26 GND           42 R38-RED         58 SPLO
      11                 27 CL60-VDD3.3   43 R37-GREEN       59 R22-SL
      12 PWSW            28 VSHD          44 VDD3.3          60 GND
      13 GND             29               45 PWM.SPI.CLK     61 R79-VR3.PIN2
      14 GND             30 VDD5          46 PWM.SPI.D       62
      15 GND             31 U9-LEDA1      47 PWM.SPI.Q       63
      16 VQ5             32               48 PWM.SPI.SEL     64

NDS-LITE Power Switch

      1 PWSW (grounded when switch is pulled)
      2 GND
      3 GND
      4 NC? (grounded when switch is not pulled)

Pinouts - Wifi

NDS RFU Daughter Board (Firmware FLASH, Wifi BB/RF Chips)

      1 N/A      6 FMW.CLK    11 ENABLE 16 RX.DTA? 21 BB./CS     26 22MHz   31 GND
      2 GND      7 FMW./SEL   12 GND    17 TX.MAIN 22 RF./CS     27 GND     32 GND
      3 high?    8 FMW.DTA.Q  13 GND    18 GND     23 BB.RF.CLK  28 VDD3.3  33 GND
      4 RXTX.ON  9 FMW.DTA.D  14 TX.ON  19 TX.CLK  24 BB.RF.RD   29 VDD1.8
      5 FMW./WP  10 FMW./RES  15 RX.ON  20 TX.DTA  25 BB.RF.WR   30 GND

NDS-Lite RFU Daughter Board DWM-W006 (Firmware FLASH, Wifi BB/RF Chip)

      1 GND      6 GND       11 BB.RF.WR  16 VDD3.3   21 RF.SLEEP  26 FMW.Q
      2 TXPE     7 TRCLK     12 BB.RF.CLK 17 GND      22 FMW./RES  27 FMW./WP
      3 RXPE     8 TRDATA    13 GND       18 RF./CS   23 GND       28 FMW./CS
      4 CCA      9 GND       14 MCLK      19 BB.SLEEP 24 FMW.CLK   29 LD  ;hi?
      5 TRRDY    10 BB.RF.RD 15 GND       20 BB./CS   25 FMW.D     30 GND

https://fccid.io/EW4DWMW006/Label/ID-label-format-and-location-706511.pdf
Wifi RF Chip: RF9008, 0441, E0121Q (32 pin)

      1       5       9       13      17         21 RF.CLK  25        29
      2       6       10      14 GND  18         22         26        30
      3       7       11      15      19 RF.RD   23         27        31
      4       8       12      16      20 RF./CS  24         28        32

Pin19 RF.RD (oops, should be WR, maybe I've exchanged RD-WR?)
Pin20 RF./CS (via 10ohm)
Pin21 RF.CLK (via 10ohm)
Resembles RF2958 datasheet...?
Wifi BB Chip: Mitsumi, Japan, 4418, MM3155 (48 pins)

      1 GND   7       13 GND     19      25       31         37 TX.MAIN 43
      2       8       14         20      26       32 BB./CS  38 RX.DTA? 44
      3       9       15 BB.CLK  21      27       33 TX.DTA  39 RX.ON   45 GND
      4       10      16 BB.WR   22      28 RST   34 RXTX.ON 40 TX.ON   46
      5       11      17 BB.RD   23      29       35 TX.CLK  41         47
      6       12      18 22MHz   24      30       36         42         48

Pin15 BB.CLK (via 10ohm to RFU.23)
Pin16 BB.WR (RFU.25)
Pin17 BB.RD (RFU.24)
Pin18 22MHz (via 50ohm)
Pin28 RST (same as FMW./RES)
Pin32 BB./CS (RFU.21)
The chip is roughly resembling HSP3824/HFA3824A/HFA3860A/HFA3860B (though pinout and registers aren't compatible).
NDS-LITE BB/RF-Chip Mitsumi MM3218 (56 pins)

      1-VDD18 8-GND   15-CCA    22-GND   29-VDD33     36-BBRF_SDO 43-VDD18 50-
      2-GND   9-NC    16-TXPE   23-MCLK  30-          37-BB_SCS   44-...   51-
      3-VDD18 10-GND  17-RXPE   24-VDD18 31-          38-RF_SCS   45-VDD33 52-VDD18
      4-Ant   11-GND  18-TRRDY  25-NC    32-VDD18     39-GND      46-...   53-NC
      5-Ant'  12-GND  19-TRDATA 26-22MHz 33-VDD18     40-VDD33    47-...   54-NC
      6-VDD18 13-NC   20-VDD33  27-22MHz 34-BBRF_SCLK 41-RF_SLEEP 48-VDD33 55-NC
      7-VDD18 14-/RES 21-TRCLK  28-      35-BBRF_SDI  42-BB_SLEEP 49-GND   56-NC

Note: Pinout should be same as in DSi (see DSi pinout for details).
TX Signal/Timing Chart (Host Game)

      RX.DTA?  __________________________________________________________
      RXTX.ON  __-----------------------_________________________________
      RX.ON    __---_______-------------_________________________________
      TX.ON    _____-------______________________________________________
      TX.MAIN  ________----______________________________________________
      TX.CLK   _____#__####______________________________________________
      TX.DTA   _____#__####______________________________________________

This example shows a host sending beacons. The pre-beacon receive period is probably to sense conflicts with other transmitters. The post-beacon receive period is to get responses from other players. The two transmit parts are: The hardware header, followed by inactivity on the tx pins during the rest of the preamble period, then followed by the actual IEEE frame. The rest of the time is spent in idle mode to reduce power consumption.
RX Signal/Timing Chart (Join Game)

      RX.DTA?  __________________________________________________________
      RXTX.ON  -----------------------------------------------______-----
      RX.ON    -----------------------------------------------_________--
      TX.ON    __________________________________________________________
      TX.MAIN  __________________________________________________________
      TX.CLK   __________________________________________________________
      TX.DTA   _______________________________________________---________

This example shows a client trying to receive beacons, so most of the time is spent in receive mode (the short idle periods are probably occuring when it is switching to another channel). Once when it has associated with a host, the client may spend more time in idle mode, and needs to be in receive mode only when expecting to receive beacons or other data.

Pinouts - Various

Advance Gameboy 256Kbytes RAM 128Kx16bit (NEC D442012LGY-B85x-MJH) (wide)
GBA SP 256Kbytes RAM 128Kx16bit (F 82D12160-10FN) (square)

      1 A15   7 A9    13 IC    19 A6   25 A0   31 D2   37 VCC  43 D15
      2 A14   8 A8    14 /UB   20 A5   26 /CE1 32 D10  38 D5   44 D8
      3 A13   9 NC    15 /LB   21 A4   27 GND  33 D3   39 D13  45 D16
      4 A12   10 NC   16 NC    22 A3   28 /OE  34 D11  40 D6   46 GND
      5 A11   11 /WE  17 NC    23 A2   29 D1   35 D4   41 D14  47 NC
      6 A10   12 CE2  18 A7    24 A1   30 D9   36 D12  42 D7   48 A16

Connection in GBA and GBA SP: IC-GND, /CE1-GND, CE2-VDD2, VCC-VDD2, Pin16-VDD2, the other NC pins seem to be actually not connected, all other pins connect to the corresponding Wxx CPU pins. Note: Both GBA and GBA SP have soldering points for wide (12x18mm) and square (12x14mm) RAMs, so either could be used.
The GBA additionally contains 32K built-in WRAM, and built-in VRAM, so the above 256K RAM chip is probably not used in 8bit classic/color gameboy mode.
Note: In the GBA Micro, the 256K RAM are contained on-chip in the CPU.
Advance Gameboy Schematic Fragments
P2-VSS = VDD-15
VIN = VCC3 via R33
REGEXT (on my modified board, REGEXT underneath of my diodes)
/RES (OUT) (via R40)
/CS (via R39)
/WR (via R38)
SC (via Rxx)
SD (via Rxx)
SI (via Rxx)
SO (via Rxx)
DCK (via R36)
A-GND via CP4 (100uF) to GND (used speaker, and on headphone socket)
GBA SP Schematic Fragments
P2VDD = VDD13
P2VSS = VDD15
/RES via R46
/CS via R45
/WR via R44
DCK via R20
VS=BT+
In my repaired GBA-SP: CK1 test-point is disconnected (instead GND'ed).
In my repaired GBA-SP: broken oscillator replaced
In my repaired GBA-SP: broken r1 1mOhm replaced (near oscillator)
In my repaired GBA-SP: broken EXT2 socket metal-spring/snapper removed
CL1 FIQ (near SW4)
CL2 ?
CL3 ?
CL4 VOUT1/VDD1 (near U4)
CL5 VOUT3/VDD3 (near U4)
CL6 VOUT5/VDD5 (near U4)
DL1-red (power low) ---R32--Q4--R6--
DL2-green (power good) ---Q6--LOWBAT/R34-VDD3
DL3-orange (charge) --R24--Q2--VIN/U57
P2VDD--VDD13
P2VSS--VDD15
S+ and S- are (almost) shortcut by R23 (1.0 ohm)
S+ via Q1 to VIN
VS via D1 to S-
A-GND via CP1 (100uF) to GND
U4 pin 12 to r6 (towards red led)
U4 pin 14 to D6---to U7
SC (CPU pin48) with R7 100K ohm pullup to VDD35
P35 via Q11 to SW (speaker disable)
GBA SP Backlight-Button Schematic (U6,U8,Q12)

            ______                _____
      GND--|1 U8 6|-- U85        |     |--VDD5
      U82--|2    5|-- U85    U61-| Q12 |         U83  ------> to display
      U83--|3____4|-- U82        |_____|--Q12B   Q12B <------ from button
      U61--|1 U6 8|--VDD5    (X)---R51--VDD5    (X)---C70--GND
      U62--|2    7|--VDD5    U62---R49--VDD5    U61---R40--GND
      U62--|3    6|--(X)     Q12B--R39--VDD5    U82---R38--GND
      GND--|4____5|--NC?     Q12B--C69--VDD5    U85---R50--U62

AUX Xboo PC-to-GBA Multiboot Cable

Below describes how to connect a PC parallel port to the GBA link port, allowing to upload small programs (max 256 KBytes) from no$gba's Utility menu into real GBAs.
This is possible because the GBA BIOS includes a built-in function for downloading & executing program code even when no cartridge is inserted. The program is loaded to 2000000h and up in GBA memory, and must contain cartridge header information just as for normal ROM cartridges (nintendo logo, checksum, etc., plus some additional multiboot info).
Basic Cable Connection
The general connection is very simple (only needs four wires), the only problem is that you need a special GBA plug or otherwise need to solder wires directly to the GBA mainboard (see Examples below).

      GBA  Name  Color                 SUBD CNTR Name
      2    SO    Red     ------------- 10   10   /ACK
      3    SI    Orange  ------------- 14   14   /AUTOLF
      5    SC    Green   ------------- 1    1    /STROBE
      6    GND   Blue    ------------- 19   19   GND

Optionally, also connect the following signals (see notes below):

      4    SD    Brown   ------------- 17   36   /SELECT  (double speed burst)
      3    SI    Orange  ----[===]---- 2..9 2..9 D0..7    (pull-up, 560 Ohm)
      5    SC    Green   ----[===]---- 2..9 2..9 D0..7    (pull-up, 560 Ohm)
      4    SD    Brown   ----[===]---- 2..9 2..9 D0..7    (pull-up, 560 Ohm)
      START  (mainboard) -----|>|----- 16   31   /INIT    (auto-reset, 1N4148)
      SELECT (mainboard) -----|>|----- 16   31   /INIT    (auto-reset, 1N4148)
      RESET  (mainboard) -----||------ 16   31   /INIT    (auto-reset, 300nF)

Notes: The GBA Pins are arranged from left to right as 2,4,6 in upper row, and 1,3,5 in lower row; outside view of GBA socket; flat side of socket upside. The above "Colors" are as used in most or all standard Nintendo link cables, note that Red/Orange will be exchanged at one end in cables with crossed SO/SI lines. At the PC side, use the SUBD pin numbers when connecting to a 25-pin SUBD plug, or CNTR pin numbers for 36-pin Centronics plug.
Optional SD Connection (Double Speed Burst)
The SD line is used for Double Speed Burst transfers only, in case that you are using a gameboy link plug for the connection, and if that plug does not have a SD-pin (such like from older 8bit gameboy cables), then you may leave out this connection. Burst Boot will then only work half as fast though.
Optional Pull-Ups (Improves Low-to-High Transition Speed)
If your parallel port works only with medium or slow delay settings, try to connect 560 Ohm resistors to SI/SC/SD inputs each, and the other resistor pin to any or all of the parallel port data lines (no$gba outputs high to pins 2..9).
Optional Reset Connection (CAUTION: Connection changed September 2004)
The Reset connection allows to automatically reset & upload data even if a program in the GBA has locked up (or if you've loaded a program that does not support nocash burst boot), without having to reset the GBA manually by switching it off and on (and without having to press Start+Select if a cartridge is inserted).
The two diodes should be 1N4148 or similar, the capacitor should be 300nF (eg. three 100nF capacitors in parallel). The signals are labeled on the mainboard, and can be found at following names / CPU pin numbers: RESET/CPU.125, SELECT/TP2/CPU.126, START/TP3/CPU.127.
Optional Power Supply Connection
Also, you may want to connect the power supply to parallel port data lines, see chapter Power Supply for details.
Transmission Speed
The first transfer will be very slow, and the GBA BIOS will display the boot logo for at least 4 seconds, even if the transfer has completed in less time. Once when you have uploaded a program with burst boot backdoor, further transfers will be ways faster. The table below shows transfer times for 0KByte - 256KByte files:

      Boot Mode_____Delay 0_______Delay 1_______Delay 2_____
      Double Burst  0.1s - 1.8s   0.1s - 3.7s   0.1s - 5.3s
      Single Burst  0.1s - 3.6s   0.1s - 7.1s   0.1s - 10.6s
      Normal Bios   4.0s - 9.0s   4.0s - 12.7s  4.0s - 16.3s

All timings measured on a 66MHz computer, best possible transmission speed should be 150KBytes/second. Timings might slightly vary depending on the CPU speed and/or operating system. Synchronization is done by I/O waitstates, that should work even on faster computers. Non-zero delays are eventually required for cables without pull-ups.
Requirements
Beside for the cable and plugs, no special requirements.
The cable should work with all parallel ports, including old-fashioned one-directional printer ports, as well as modern bi-directional EPP ports. Transfer timings should work stable regardless of the PCs CPU speed (see above though), and regardless of multitasking interruptions.
Both no$gba and the actual transmission procedure are using some 32bit code, so that either one currently requires 80386SX CPUs or above.
Connection Examples
As far as I can imagine, there are four possible methods how to connect the cable to the GBA. The first two methods don't require to open the GBA, and the other methods also allow to connect optional power supply and reset signal.

      1) Connect it to the GBA link port. Advantage: No need to
         open/modify the GBA. Disadvantage: You need a special plug,
         (typically gained by removing it from a gameboy link cable).
      2) Solder the cable directly to the GBA link port pins. Advantages:
         No plug required & no need to open the GBA. Disadvantages:
         You can't remove the cable, and the link port becomes unusable.
      3) Solder the cable directly to the GBA mainboard. Advantage: No
         plug required at the GBA side. Disadvantage: You'll always
         have a cable leaping out of the GBA even when not using it,
         unless you put a small standard plug between GBA and cable.
      4) Install a Centronics socket in the GBA (between power switch
         and headphone socket). Advantage: You can use a standard
         printer cable. Disadvantages: You need to cut a big hole into
         the GBAs battery box (which cannot be used anymore), the big
         cable might be a bit uncomfortable when holding the GBA.

Personally, I've decided to use the lastmost method as I don't like ending up with hundreds of special cables for different purposes, and asides, it's been fun to damage the GAB as much as possible.
Note
The above used PC parallel port signals are typically using 5V=HIGH while GBA link ports deal with 3V=HIGH. From my experiences, the different voltages do not cause communication problems (and do not damage the GBA and/or PC hardware), and after all real men don't care about a handful of volts, however, use at own risk.

AUX Xboo Flashcard Upload

Flashcard Upload
Allows to write data to flashcards which are plugged into GBA cartridge slot, cartridge is automatically started after writing. On initial power-up, hold down START+SELECT to prevent the GBA from booting the old program in the flashcard.
The Upload function in Utility menu uses flashcard mode for files bigger than 256KB (otherwise uses multiboot mode automatically). Also, there's a separate Upload to Flashcard function in Remote Access submenu, allowing to write files of 256KB or less to flashcard if that should be desired.
Supported Flashcards
Function currently tested with Visoly Flash Advance (FA) 256Mbit (32MB) Turbo cartridge. Should also work with older FA versions. Please let me know if you are using other flashcards which aren't yet supported.
Flashcard Performance
Writing to flashcards may become potentially slow because of chip erase/write times, cable transmission time, and the sheer size of larger ROM-images. However, developers whom are testing different builts of their project usually won't need to rewrite the complete flashcard, Xboo uses a highspeed checksum mechanism (16MB/sec) to determine which flashcard sector(s) have changed, and does then re-write only these sector(s).
To eliminate transmission time, data transfer takes place in the erase phases. Erase/write time depends on the flashcard type, should be circa 1-2 seconds per 256KB sector. Because the cartridge is programmed directly in the GBA there's no need to remove it from the GBA when writing to it.
Developers Advice
Locate your program fragments at fixed addresses, for example, code and data blocks each aligned to 64K memory boundaries, so that data remains at the same location even when the size of code changes. Fill any blank spaces by value FFh for faster write time. Reduce the size of your ROM-image by efficient memory use (except for above alignment trick). Include the burst boot backdoor in your program, allowing to re-write the flashcard directly without resetting the GBA.
Lamers Advice
Xboo Flashcard support does not mean to get lame & to drop normal multiboot support, if your program fits into 256KB then make it <both> flashcard <and> multiboot compatible - multiboot reduces upload time, increases your flashcard lifetime, and will also work for people whom don't own flashcards.

AUX Xboo Burst Boot Backdoor

When writing Xboo compatible programs, always include a burst boot "backdoor", this will allow yourself (and other people) to upload programs much faster as when using the normal GBA BIOS multiboot function. Aside from the improved transmission speed, there's no need to reset the GBA each time (eventually manually if you do not have reset connect), without having to press Start+Select (if cartridge inserted), and, most important, the time-consuming nintendo-logo intro is bypassed.
The Burst Boot Protocol
In your programs IRQ handler, add some code that watches out for burst boot IRQ requests. When sensing a burst boot request, download the actual boot procedure, and pass control to that procedure.

      Send (PC)    Reply (GBA)
      "BRST"       "BOOT"        ;request burst, and reply <prepared> for boot
      <wait 1/16s> <process IRQ> ;long delay, allow slave to enter IRQ handler
      llllllll     "OKAY"        ;send length in bytes, reply <ready> to boot
      dddddddd     --------      ;send data in 32bit units, reply don't care
      cccccccc     cccccccc      ;exchange crc (all data units added together)

Use normal mode, 32bit, external clock for all transfers. The received highspeed loader (currently approx. 180h bytes) is to be loaded to and started at 3000000h, which will then handle the actual download operation.
Below is an example program which works with multiboot, burstboot, and as normal rom/flashcard. The source can be assembled with a22i (the no$gba built-in assembler, see no$gba utility menu). When using other/mainstream assemblers, you'll eventually have to change some directives, convert numbers from NNNh into 0xNNN format, and define the origin somewhere in linker/makefile instead of in source code.

     .arm            ;select 32bit ARM instruction set
     .gba            ;indicate that it's a gameboy advance program
     .fix            ;automatically fix the cartridge header checksum
     org 2000000h    ;origin in RAM for multiboot-cable/no$gba-cutdown programs
     ;------------------
     ;cartridge header/multiboot header
      b     rom_start                ;-rom entry point
      dcb   ...insert logo here...   ;-nintento logo (156 bytes)
      dcb   'XBOO SAMPLE '           ;-title (12 bytes)
      dcb   0,0,0,0,  0,0            ;-game code (4 bytes), maker code (2 bytes)
      dcb   96h,0,0                  ;-fixed value 96h, main unit code, device type
      dcb   0,0,0,0,0,0,0            ;-reserved (7 bytes)
      dcb   0                        ;-software version number
      dcb   0                        ;-header checksum (set by .fix)
      dcb   0,0                      ;-reserved (2 bytes)
      b     ram_start                ;-multiboot ram entry point
      dcb   0,0                      ;-multiboot reserved bytes (destroyed by BIOS)
      dcb   0,0                      ;-blank padded (32bit alignment)
     ;------------------
     irq_handler:  ;interrupt handler (note: r0-r3 are pushed by BIOS)
      mov    r1,4000000h             ;\get I/O base address,
      ldr    r0,[r1,200h] ;IE/IF     ; read IE and IF,
      and    r0,r0,r0,lsr 16         ; isolate occurred AND enabled irqs,
      add    r3,r1,200h   ;IF        ; and acknowledge these in IF
      strh   r0,[r3,2]               ;/
      ldrh   r3,[r1,-8]              ;\mix up with BIOS irq flags at 3007FF8h,
      orr    r3,r3,r0                ; aka mirrored at 3FFFFF8h, this is required
      strh   r3,[r1,-8]              ;/when using the (VBlank-)IntrWait functions
      and    r3,r0,80h ;IE/IF.7 SIO  ;\
      cmp    r3,80h                  ; check if it's a burst boot interrupt
      ldreq  r2,[r1,120h] ;SIODATA32 ; (if interrupt caused by serial transfer,
      ldreq  r3,[msg_brst]           ; and if received data is "BRST",
      cmpeq  r2,r3                   ; then jump to burst boot)
      beq    burst_boot              ;/
      ;... insert your own interrupt handler code here ...
      bx     lr                      ;-return to the BIOS interrupt handler
     ;------------------
     burst_boot:     ;requires incoming r1=4000000h
      ;... if your program uses DMA, disable any active DMA transfers here ...
      ldr   r4,[msg_okay]            ;\
      bl    sio_transfer             ; receive transfer length/bytes & reply "OKAY"
      mov   r2,r0 ;len               ;/
      mov   r3,3000000h   ;dst       ;\
      mov   r4,0  ;crc               ;
     @@lop:                          ;
      bl    sio_transfer             ; download burst loader to 3000000h and up
      stmia [r3]!,r0      ;dst       ;
      add   r4,r4,r0      ;crc       ;
      subs  r2,r2,4       ;len       ;
      bhi   @@lop                    ;/
      bl    sio_transfer             ;-send crc value to master
      b     3000000h  ;ARM state!    ;-launch actual transfer / start the loader
     ;------------------
     sio_transfer:  ;serial transfer subroutine, 32bit normal mode, external clock
      str   r4,[r1,120h]  ;siodata32 ;-set reply/send data
      ldr   r0,[r1,128h]  ;siocnt    ;\
      orr   r0,r0,80h                ; activate slave transfer
      str   r0,[r1,128h]  ;siocnt    ;/
     @@wait:                         ;\
      ldr   r0,[r1,128h]  ;siocnt    ; wait until transfer completed
      tst   r0,80h                   ;
      bne   @@wait                   ;/
      ldr   r0,[r1,120h]  ;siodata32 ;-get received data
      bx    lr
     ;---
     msg_boot dcb 'BOOT'     ;\
     msg_okay dcb "OKAY"     ; ID codes for the burstboot protocol
     msg_brst dcb "BRST"     ;/
     ;------------------
     download_rom_to_ram:
      mov  r0,8000000h  ;src/rom     ;\
      mov  r1,2000000h  ;dst/ram     ;
      mov  r2,40000h/16 ;length      ; transfer the ROM content
     @@lop:                          ; into RAM (done in units of 4 words/16 bytes)
      ldmia [r0]!,r4,r5,r6,r7        ; currently fills whole 256K of RAM,
      stmia [r1]!,r4,r5,r6,r7        ; even though the proggy is smaller
      subs  r2,r2,1                  ;
      bne   @@lop                    ;/
      sub   r15,lr,8000000h-2000000h ;-return (retadr rom/8000XXXh -> ram/2000XXXh)
     ;------------------
     init_interrupts:
      mov  r4,4000000h               ;-base address for below I/O registers
      ldr  r0,=irq_handler           ;\install IRQ handler address
      str  r0,[r4,-4]   ;IRQ HANDLER ;/at 3FFFFFC aka 3007FFC
      mov  r0,0008h                  ;\enable generating vblank irqs
      strh r0,[r4,4h]   ;DISPSTAT    ;/
      mrs  r0,cpsr                   ;\
      bic  r0,r0,80h                 ; cpu interrupt enable (clear i-flag)
      msr  cpsr,r0                   ;/
      mov  r0,0                      ;\
      str  r0,[r4,134h] ;RCNT        ; init SIO normal mode, external clock,
      ldr  r0,=5080h                 ; 32bit, IRQ enable, transfer started
      str  r0,[r4,128h] ;SIOCNT      ; output "BOOT" (indicate burst boot prepared)
      ldr  r0,[msg_boot]             ;
      str  r0,[r4,120h] ;SIODATA32   ;/
      mov  r0,1                      ;\interrupt master enable
      str  r0,[r4,208h] ;IME=1       ;/
      mov  r0,81h                    ;\enable execution of vblank IRQs,
      str  r0,[r4,200h] ;IE=81h      ;/and of SIO IRQs (burst boot)
      bx   lr
     ;------------------
     rom_start:   ;entry point when booted from flashcart/rom
      bl   download_rom_to_ram       ;-download ROM to RAM (returns to ram_start)
     ram_start:   ;entry point for multiboot/burstboot
      mov  r0,0feh                   ;\reset all registers, and clear all memory
      swi  10000h ;RegisterRamReset  ;/(except program code in wram at 2000000h)
      bl   init_interrupts           ;-install burst boot irq handler
      mov  r4,4000000h               ;\enable video,
      strh r4,[r4,000h] ;DISPCNT     ;/by clearing the forced blank bit
     @@mainloop:
      swi  50000h ;VBlankIntrWait    ;-wait one frame (cpu in low power mode)
      mov  r5,5000000h               ;\increment the backdrop palette color
      str  r8,[r5]                   ; (ie. display a blinking screen)
      add  r8,r8,1                   ;/
      b    @@mainloop
     ;------------------
     .pool
     end

DSi Emulation

Activating DSi emulation (disabled by default)
The DSi emulation is still DISABLED by default, and must be enabled manually by setting the "NDS Mode/Colors" option to "DSi (retail/16MB)".
The reason is that most DSi-enhanced games are still running into troubles in DSi emulation mode (but should work fine in NDS emulation mode).
DSi eMMC bootcode emulation
This is the newest feature, and also the most important breakthrough, as it's allowing to understand the boot process & memory initialization from scratch up. Getting there wasn't easy (eight months of research & programming - just to get the emulation to display the damn bootscreen).
Using that emulation feature requires DSi BIOS dumps, eMMC dump, and Wifi-Flash dump. Getting that files together isn't exactly easy, but I hope that 5-10 people might known how to do it, and that 0-2 of them might be actually reading this someday.
The lower 32K halves of the ARM7/ARM9 BIOSes can be dumped quite easily (if you have any working DSi exploit), the DSi keys in upper 32K halves can be dumped indirectly (via simple exploits on 3DS, or via difficult main memory hacks on DSi). For details, see:
BIOS Dumping
Getting the eMMC image requires some soldering (or sudokuhax), the image must include a footer with CID/CPU IDs (needed for decryption; obviously those IDs will also tell Nintendo 'who you are', in case you should consider leaking your eMMC dump). For details, see:
DSi SD/MMC Images
DSi Console IDs
AUX DSi SD/MMC Pin-Outs
Optionally, a copy of the DSi Wifi Flash can be stored in file "WIFI-DSI.BIN" (should be usually 128Kbytes; or, reportedly it's smaller on newer DSi's). That file only contains only some stuff like wifi calibration values, no$gba is auto-generating some dummy calibration values if the file is missing (so the file is needed only if you want to do something like experimenting with different calibration settings).
If needed, the Wifi Flash can be dumped via SPI bus wiring (from wifi daughterboard), or via raw software (in case you can run NDS or DSi programs on your DSi console). For details, see the "Firmware" sections (named so because, on NDS, the Wifi Flash did also contain the firmware):
DS Cartridges, Encryption, Firmware
Then, set the "Reset/Startup Entrypoint" option in no$gba to "BIOS", and load a DSi cartridge or DSiware file (just as a dummy file, to switch the emulation into DSi mode; the file should be theoretically shown in bootmenu, but that doesn't work yet because the function of the tiny 4bit SCFG_MC register is still unknown).
Currently working is: The infamous health/safety crap, and displaying the bootmenu (selecting any items in bootmenu will start issuing eMMC writes, which isn't emulated yet, so the emu won't get any farther).
DSi Atheros Wifi BIOS
The Atheros Wifi BIOS is loaded from these filenames (in no$gba directory):

      AR6002G.ROM  ;old DSi wifi chip (80Kbytes)   ;wifi-flash[1FDh]=1
      AR6013G.ROM  ;new DSi wifi chip (256Kbytes)  ;wifi-flash[1FDh]=2
      AR6014G.ROM  ;3DS wifi chip     (256Kbytes)  ;wifi-flash[1FDh]=3

presence of that file doesn't affect emulation, it's used solely for viewing the wifi bios in the disassembler (via menubar, window, xtensa/wifi). The wifi bios can be dumped via SDIO functions WINDOW_READ_ADDR and WINDOW_DATA.
DSi Cartridge emulation
For DSi ROM images, set the "Reset/Startup Entrypoint" to "Start Cartridge directly" (this will skip the eMMC boot process, so you don't need the eMMC dump, and you might also get away without BIOS dump, or with partial lower BIOS 32K dumps).
Then, load a DSi ROM-image (observe that older dumping tools can dump only the NDS areas of DSi cartridges; such incomplete dumps won't work in DSi mode).
Tested are two games: Cooking Coach (not working yet), and System Flaw (works, but requires cameras for use as "motion sensors", so it isn't actually playable). Going by reports from other users, most or all other DSi cartridges aren't working yet.
DSi DSiware emulation
DSiware games can be exported to SD card, and the SD card files can be decrypted via homebrew DSi SRL Extract utility (system files can be also downloaded and decrypted via homebrew NUS Downloader utility).
Loading the decrypted files into no$gba is currently acting as if the files were cartridge ROM images (rather than files on eMMC). Surprisingly, this is actually working to some extent (the games are loading extra data from ROM, instead of from eMMC, which they should be usually doing). However, loading/saving game positions appears to be routed to eMMC (not to cartridge FLASH/EEPROM). Apart from that, most DSiware games are probably stumbling over this or that unemulated detail or uninitialized memory area.
Nothing working?
Depends on what you want: If you want to play games, then, yes, I don't know of any DSi games that are working/playable yet. If you want to do programming/debugging, then you might find out that almost everything is more or less working. I don't know of any other active DSi devrs though - not too surprising since the DSi is definitely the most complicated and most unattractive console that I've ever seen.

Notes on New NDS Emulation

Hello to newer no$gba version(s) with NDS support. Most of it is working fine by now, a few details are still under construction. The most important (missing) things to be aware of are:
Major Missing Features
WLAN emulation is almost complete (but still incompatible with commercial games) (parts for transfer timing reasons, and parts because nobody knows yet how multiplayer packets work).
3D emulation is almost complete, too, only missing feature is Anti-Aliasing.
Things that work only with real NDS-BIOS-image
The "decompression-with-callback" BIOS functions are currently working only if you do have a copy of the real BIOSes as ROM-images (see Installation and DS Xboo chapters).
Encrypted ROM-images (with encrypted first 2Kbytes of the secure area) can be used only if the (full) NDS7 BIOS ROM-image is present (which contains the 1048h-byte decryption seed data).
Minor Missing Features and Glitches (in NDS mode)
VRAM viewer Tile/OBJ windows don't work.
Saving Snapshots doesn't work yet.
Backup media type isn't autodetected.
Recommended TCM Areas
No$gba decodes memory blocks by examining address bits24-27 (so memory is split into 16MB blocks). TCM emulation works fastest if DTCM and ITCM are each located at the bottom of free 16MB blocks (ie. blocks that do not contain other memory, such like WRAM, VRAM, etc.), recommended ITCM/DTCM base addresses would be:

      ITCM at 00000000h, or (mirrored to) 01000000h.
      DTCM at 01000000h, 0B000000h, 0C000000h, 0D000000h, or 0E000000h.

Other addresses are supported by no$gba v2.2c and up, for example, the Metroid Demo uses DTCM base overlapping with the Main Memory region, a possible advantage is that DTCM & Main RAM can be used as continous memory region, however, the emulation performance won't be optimal.
Note
Use Ctrl+T in debug mode to toggle between the two CPUs.

Pocketstation Emulation

The Sony Pocketstation is a memory card with ARM processor and 32x32 pixel LCD screen for Sony Playstation consoles. As such, it doesn't have much to do with GBA/NDS.
Anyways, as I haven't got around to implement ARM emulation in no$psx yet, the Pocketstation is currently emulated as part of the no$gba project (eventually it might be moving from no$gba to no$psx someday in future).
Pocketstation BIOS
For using a copy of the original 16Kbyte BIOS: store it as file POCKSTAT.ROM in no$gba directory. If that file isn't present, then no$gba will use it's own built-in BIOS clone.
Pocketstation Specs
For tech info on memory map, I/O ports, bios, file formats, see:

      http://problemkaputt.de/psx-spx.htm#pocketstation

For info on the ARM processor, see:
ARM CPU Reference
For info on the POC-XBOO upload circuit see:
Pocketstation XBOO Cable

Pocketstation XBOO Cable

[This chapter will be moved to no$psx v1.7 specs; once when v1.7 is released]
This circuit allows to connect a pocketstation to PC parallel port, allowing to upload executables to real hardware, and also allowing to download TTY debug messages (particulary useful as the 32x32 pixel LCD screen is ways too small to display any detailed status info).
POC-XBOO Circuit
Use a standard parallel port cable (with 36pin centronics connector or 25pin DB connector) and then build a small adaptor like this:

      Pin CNTR  DB25          Pocketstation          _______________________
      ACK 10    10  --------- 1 JOYDTA              |       |       |       |
      D0  2     2   --------- 2 JOYCMD              | 9 7 6 | 5 4 3 |  2 1  | CARD
      GND 19-30 18-25 ------- 4 GND                 |_______|_______|_______|
      D1  3     3   --------- 6 /JOYSEL              _______________________
      D2  4     4   --------- 7 JOYCLK              |       |       |       |
      PE  12    12  --------- 9 /JOYACK (/IRQ7)     | 9 8 7 | 6 5 4 | 3 2 1 | PAD
      NC -------------------- 8 /JOYGUN (/IRQ10)     \______|_______|______/
      NC -------------------- 3 7.5V (rumble.supply)
      SUPPLY.5V --|>|---|>|-- 5 3.5V (VCC) (eg. PC's +5V via two 1N4001 diodes)
      SUPPLY.0V ------------- 4 GND (not needed when same as GND on CNTR/DB25)

The circuit is same as for "Direct Pad Pro" (but using a memory card connector instead of joypad connector, and needing +5V from PC power supply instead of using parallel port D3..D7 as supply). Note: IRQ7 is optional (for faster/early timeout).
POC-XBOO Upload
The upload function is found in no$gba "Utility" menu. It does upload the executable and autostart it via standard memory card/pocketstation commands (ie. it doesn't require any special transmission software installed on the pocketstation side).
Notes: Upload is overwriting ALL files on the memory card, and does then autostart the first file. Upload is done as "read and write only if different", this provides faster transfers and higher lifetime.
POC-XBOO TTY Debug Messages
TTY output is conventionally done by executing the ARM CPU's Undefined Opcode with an ASCII character in R0 register (for that purpose, the undef opcode handler should simply point to a MOVS PC,LR opcode).
That kind of TTY output works in no$gba's pocketstation emulation. It can be also used via no$gba's POC-XBOO cable, but requires some small customization in the executable:
First of, the executable needs "TTY+" ID in some reserved bytes of the title sector (telling the xboo uploader to stay in transmission mode and to keep checking for TTY messages after the actual upload):

      TitleSector[58h] = "TTY+"

With that ID, and with the XBOO-hardware being used, the game will be started with with "TTY+" in R0 (notifying it that the XBOO hardware is present, and that it needs to install special transmission handlers):

     ;------------------
     .data?
     org  200h
     ...
     tty_bufsiz equ 128  ;max=128=fastest (can be smaller if you are short of RAM)
     func3_info:                                       ;\ ;\
      func3_buf_base     dd 0   ;fixed="func3_buf"     ;  ;  func3_info+00h
      func3_buf_len      dd 0   ;range=0..128          ;/ ;  func3_info+04h
      func3_stack        dd 0                             ;  func3_info+08h
      func3_buffer:      defs tty_bufsiz                  ;/ func3_info+0Ch
     ptr_to_comflags     dd 0
     ...
     .code
     ...
     ;------------------
     tty_wrchr:   ;in: r0=char
      dd      0e6000010h ;=undef opcode            ;-Write chr(r0) to TTY
      bx      lr
     ;------------------
     init_tty:  ;in: r0=param (from entrypoint)
      ldr     r1,=2B595454h ;"TTY+"                ;\check if xboo-cable present
      cmp     r1,r0                                ; (r0=incoming param from
      beq     @@tty_by_xboo_cable                  ;/executable's entrypoint)
     ;- - -
      mov     r1,0                                 ;\dummy und_handler
      ldr     r2,=0e1b0f00eh  ;=movs r15,r14       ; (just return from exception,
      str     r2,[r1,04h]  ;und_handler            ;/for normal cable-less mode)
      b       @@finish
     ;---
     @@tty_by_xboo_cable:
      swi     17h  ;GetPtrToFunc3addr()            ;\
      ldr     r1,=(tty_func3_handler AND 0ffffh)   ; init FUNC3 aka TTY handler
      strh    r1,[r0]                              ;/
      ldr     r1,=func3_info                       ;\
      mov     r0,0                             ;\  ; mark TTY as len=empty
      str     r0,[r1,4]        ;func3_buf_len  ;/  ; and
      add     r0,r1,0ch ;=func3_buffer         ;\  ; init func3 base
      str     r0,[r1,0]        ;func3_buf_base ;/  ;/
      mov     r1,0                                 ;\
      ldr     r2,=0e59ff018h  ;=ldr r15,[pc,NN]    ;
      str     r2,[r1,04h]  ;und_handler            ; special xboo und_handler
      add     r2,=tty_xboo_und_handler             ;
      str     r2,[r1,24h]  ;und_vector             ;/
     @@finish:
      swi     06h ;GetPtrToComFlags()              ;\
      ldr     r1,=ptr_to_comflags                  ; get ptr to ComFlags
      str     r0,[r1]                              ;/
      bx      lr
     ;------------------
     tty_xboo_und_handler:   ;in: r0=char
      ldr     r13,=func3_info ;aka sp_und          ;-base address (in sp_und)
      str     r12,[r13,8] ;func3_stack             ;-push r12
     @@wait_if_buffer_full:                        ;\
      ldr     r12,=ptr_to_comflags                 ; ;\exit if execute file request
      ldr     r12,[r12]  ;ptr to ComFlags          ; ; ComFlg.Bit11 ("bu_cmd_59h"),
      ldr     r12,[r12]  ;read ComFlags            ; ; ie. allow that flag to be
      tst     r12,1 shl 11  ;test bit11            ; ; processed by main program,
      bne     @@exit                               ; ;/without hanging here
      ldrb    r12,[r13,4] ;func3_buf_len           ; wait if buffer full
      cmp     r12,tty_bufsiz                       ; (until drained by FIQ)
      beq     @@wait_if_buffer_full                ;/
      mov     r12,1bh+0c0h  ;mode=und, FIQ/IRQ=off ;\disable FIQ (no COMMUNICATION
      mov     cpsr_ctl,r12                         ;/interrupt during buffer write)
      ldrb    r12,[r13,4]  ;func3_buf_len          ;\
      add     r12,1        ;raise len              ; write char to buffer
      strb    r12,[r13,4]  ;func3_buf_len          ; and raise buffer length
      add     r12,0ch-1    ;=func3_buffer+INDEX    ;
      strb    r0,[r13,r12] ;append char to buf     ;/
     @@exit:
      ldr     r12,[r13,8]  ;func3_stack            ;-pop r12
      movs    r15,r14        ;return from exception (and restore old IRQ/FIQ state)
     ;------------------
     tty_func3_handler:   ;in: r0=flags, r1=ptr
      tst     r0,10h  ;test if PRE/POST data (pre: Z, post: NZ)
     ;ldreq   r1,[r1]   ;read 32bit param (aka the four LEN1 bytes of FUNC3)
      ldr     r0,=func3_info   ;ptr to two 32bit values (FUNC3 return value)
      movne   r1,0                           ;\for POST data: mark buffer empty
      strne   r1,[r0,4] ;func3_buf_len=0     ;/
      bx      lr                             ;-for PRE data: return r0=func3_info

Usage: Call "init_tty" at the executable's entrypoint (with incoming R0 passed on). Call "tty_wrchr" to output ASCII characters.
Note: The TTY messages are supported only in no$gba debug version (not no$gba gaming version).

Installation

Required Hardware
Miminum requirement would be a 32bit CPU (eg. 80386SX and up). No$gba has been programmed on a 66MHz 80486DX2, smaller games (eg. simple 2D games, text output) are working relative smoothly at 100% speed on that computer. Larger games (eg. 3D games, plasma demos) may require a CPU speed of up to 400..500MHz.
Emulation performance mainly depends on whether (and how much) the game is using the low power Halt/IntrWait GBA bios functions in idle mode, or not.
Installing No$gba
Just copy the executable to harddisk, preferably into a new/blank folder, below text will refer to this folder as the 'No$gba' folder, you may use any other name though. The program will automatically create some subdirecties. For example, the Slot directory is the suggested location for rom-images.
You will eventually also need some additional files - see below!
Installing Updates
Just overwrite the old executable by the newer version. The setup file from the older version may be used, any unrecognized options will be set to the default value.
Uninstalling No$gba
The program does not infect the windows registry. If you wish to uninstall it just delete the 'No$gba' folder and all sub-directories.
Of course excluding any important files which you may have stored in these directories and which you may want to keep (ie. source code, binaries, game positions, and/or your registration key).
Optional Files
NO$GBA.ROM
No$gba includes a built-in BIOS clone which is used if the BIOS ROM-image(s) are not found. However, the emulation accuracy (eg. exact execution time) of BIOS SWI-functions increases when using the original BIOS ROM-images. BIOS images are loaded if the following file(s) exist in your no$gba folder.

      NO$GBA.ROM    GBA+NDS7+NDS9 BIOS-images (16K+16K+4K)

Alternately, the images can be split into separate files, with filenames:

      BIOSNDS.ROM   NDS7+NDS9 BIOS-images (16K+4K)
      BIOSNDS7.ROM  NDS7 BIOS-image (16K)
      BIOSNDS9.ROM  NDS9 BIOS-image (4K) (or 32K padded with zero's)
      BIOSGBA.ROM   GBA BIOS-image (16K)
      GBA.ROM       Same as BIOSGBA.ROM (16K)

For DSi emulation,

      BIOSDSI.ROM   DSi7+DSi9 BIOS-images (64K+64K)  ;\these are only 66% dumpable
      BIOSDSI7.ROM  DSi7 BIOS-image (64K)            ; yet (please pad undumped
      BIOSDSI9.ROM  DSi9 BIOS-image (64K)            ;/regions with 00h-bytes)

For 3DS emulation,

      BIOS3DS.ROM   3ds9+3ds11 BIOS-images (64K+64K) ;\
      BIOS3DS9.ROM  3ds9 BIOS-image (64K)            ; these are filly dumpable
      BIOS3DS11.ROM 3ds11 BIOS-image (64K)           ;/

The no$gba utility menu (and the Xboo tool on the no$gba webpage) includes a function for downloading the BIOS from GBA/NDS to file (by simple cable connection).
Be careful when downloading the BIOSes from internet, there seems to be a very popular GBA BIOS in the net (probably a very old prototype version), which is NOT compatible with the actual GBA release version, also some NDS7 BIOS-images may be incomplete dumps (with first 4K zero-filled), no$gba outputs a warning message if using an incorrect, incomplete, damaged, or patched BIOS version.
FIRMWARE.BIN
A copy of the original NDS firmware. This file increases emulation accuracy only by means of delaying the boot process. The no$gba setup default setting is to start the cartridge directly, without executing the BIOS/Firmware boot code, so the presence of the firmware image doesn't actually disturb emulation performance.
DSi Firmware (onboard eMMC) and DSi External SD Card
DSi SD/MMC Images
PKUNZIP.EXE and/or ARJ.EXE
These decompression programs are required when loading ARJ or ZIP compressed cartridges. The programs must be stored in a directory which is part of your 'Path' (ie. a directory which is automatically searched by the operating system, if you do not understand this, try using your C:\Windows folder). Alternately, decompress the files by hand before loading them.

Debugging

Hotkeys in Debug Mode
Breakpoints
Profiling & Performance Monitoring
Debug Messages
Symbolic Debug Info
The A22i Assembler
XED Editor

Hotkeys in Debug Mode

Most debug functions are available via hotkeys and via mouse accessible popup boxes. The popup boxes generally also show the corresponding hotkey.

     Cursor             (*) Move around
     Cursor Right           Follow (in codewin: map window to jump/call dest adr)
     Cursor Right           Follow (in stckwin: map codewin to return adr)
     Cursor Left            Undo follow (if nothing to undo: goto program counter)
     Page Up/Down       (*) Move around
     Home               (*) Goto Start or to 0000
     End                (*) Goto End or to IO-Area (FF40 codewin, FF10 datawin)
     Ret                (*) Center/Uncenter current line in code window
     Shift+Cursor           Change Active Window (Code,Data,Stck,Regs)
     Shift+Cursor       (*) Toggle between Hex- and Ascii-input in data window
     Tab                (*) Toggle Standard and Symbolic Display in code window
     Tab                (*) Toggle Lower Window (Data or Break/Watch)
     Ctrl-B                 Enter Breakpoint Address, Condition
     Ctrl-N                 Find Next Breakpoint
     Ctrl-G                 Goto Address (prompts for address) (does not affect pc)
     Ctrl-E             (*) Toggle Warnings on/off
     Ctrl-O                 OS Shell (calls DOS, type 'exit' to come back)
     Ctrl-I                 Inspect (Define Watchpoint address)
     Ctrl-R                 Reload Cartridge
     Ctrl-S                 Search (see below! this works a bit strange)
     Ctrl-C                 Continue Search
     Ctrl-V            (**) Toggle Screen Size 25/50 lines (DOS version only)
     Ctrl-D                 Toggle Datazone (see below)
     Ctrl-A/T/X         (*) Add/Toggle/Remove Machine (up to 12 gameboys at 1 time)
     Ctrl-L/W               Load/Save Snapshot (RAM, CPU-state and ROM-cartname)
     Ctrl-Left/Right    (*) Decrease/Increase start address of window by one byte
     <..>                   Assemble into Memory (input box appears on 1st char)
     F1                     Help
     F2                     Toggle Breakpoint at cursor
     F3                     Trace with calls executed
     F4                     Run to Cursor
     F5                     VRAM Viewer (last accessed screen, TAB toggles)
     F6                     Jump to Cursor (sets programcounter (pc) and rombank)
     F7                     Trace (Execute one instruction)
     F8                     Run until current sub-routine returns
     F9                     Run (until breakpoint or user break)
     F10                    Hardware Info Screen (splits in 50 lines DOS mode)
     F11                    Setup Screen (last accessed setup window)
     F12                    Cartridge Menu (last accessed, filename or files.lst)
     Scroll Lock            Toggle Datacur follows Codecur (or 16bit reg) on/off
     Keypad "/"             Run one Frame
     Keypad "*"             Reset and Run
     Keypad "-"         (*) Continue Run (same as F9)
     ESC                (*) Popup File Menu or close current window/menu
     Alt+<..>           (*) Popup Menus (eg. Alt+F for File Menu)
     Alt+A                  Animate (Repeated trace until key pressed)
     Alt+B                  Place Bookmark
     Alt+E                  Edit File
     Alt+P                  Profiler Window
     Alt+X                  Exit No$gba
     Right Mouse Button (*) DOS: Continue Run (same as F9), Windows: Context Menu
     Left Mouse Button  (*) Select Window, Place Cursor, Toggle Breakpoint or
                             CPU-flag, Open Popup Menu, Click Option, etc.

The functions that are marked by (*) are not shown in the popup menues of the menu bar. Vice versa, not all functions can be accessed through hotkeys, so to be able to access all functions you must use both hotkeys and menu bars.
See also:
Hotkeys in Emulation Mode

Hotkeys in Emulation Mode

The default keyboard controls for player #1 and player #2 are

      Up        Q          Cursor-Up
      Down      A          Cursor-Down
      Left      O          Cursor-Left
      Right     P          Cursor-Right
      Button A  Space      Keypad-"0"
      Button B  Tab        Keypad-"."
      Select    Left-Ctrl  Keypad-"3"
      Start     Enter      Keypad-Enter
      Button L  Left-Alt   L
      Button R  Right-Alt  R

In single player mode, both control sets do control the same gameboy.
The keyboard controls for player #1..#12 can be redefined in setup.
Note: The keyboard box in the DOS version wraps to the next page (for the next player) when you move the cursor out of the box with the cursor keys.
The other hotkeys during running emulation are:

      Alt+X                Exit No$gba
      Esc or Ctrl-Pause    Back to debugger (stop)
      keypad"-"            Back to debugger (start / stop)
      keypad"/"            Back to debugger (single-frame step)
      keypad"*"            Reset (Restart Game)
      keypad"+"            Whoosh. Run at max speed as long as key hold down
      Backspace            Whoosh. Same as above (for laptop's without keypad)
      Pause                Pause (Context Menu)
      Shift+F1..F5         Toggle Video Layers BG0..3,OBJ on/off
      F1..F4               Toggle Sound Channel 1..4 on/off
      F5..F6               Toggle Sound FIFO A..B on/off
      F7                   Quickload Snapshot (as 7 looks like L)
      F8                   Quicksave Snapshot (as 8 looks like S)
      F11                  Setup (Options)
      F12                  Cartridge menu
      both mouse buttons   Back to debugger
      left mouse button    Pause (menu) (under windows: right mouse button)
      other button(s)      Joypad emulation (fire/activate)
      mouse move           Joypad emulation (activated by first button click)

See Also:
Hotkeys in Debug Mode

Breakpoints

Normal Breaks (F2-key)
Normal breakpoints are set (or removed) by moving the code-window cursor onto the desired opcode, and then pushing the F2-key.
Run-to-Cursor (F4-key)
Hitting F4-key directly starts emulation, and stops when reaching the code window cursor. The break address is not memorized, ie. it is used only once.
Global Memory Read/Write Breaks
This break-family allows to capture reads/writes to specific memory addresses, or memory areas. Membreaks are defined by pressing Ctrl+B, and then entering a memory address or area in square brackets,

      [3007ffc]            single address (eg. GBA IRQ vector)
      [6000000..6003fff]   memory area    (eg. first 16K of VRAM)

followed by question and/or exclamation marks, indicating the type,

      ?     break on any read (from specified address/area)
      !?    break on any read or changed write
      !!?   break on any read or any write
      !     break on changed write
      !!    break on any write

Question marks ("?") capture reads. Double exclamation marks ("!!") will capture ALL writes, single exclamation marks ("!") capture only writes that are changing the memory content (ie. the new data must be different than old data). The ordering (eg. "!!?" or "!?!" or "?!!") is don't care.
Local Conditional Breakpoints
Press Ctrl-B and define the break by entering "address, condition". The emulator will stop when the program counter reaches the address, and when the condition is true. The "$" symbol represents the current cursor address of code window. Examples:

      $, r0<>0           --> break at cursor position if r0 is non-zero
      $, r0 & 2          --> break at cursor position if bit 1 of r0 is set
      $, r0 !& 2         --> break at cursor position if bit 1 of r0 is zero
      8001234, [r1]=r2   --> break at 8001234 if r1 points at a value equal to r2
      wrchr              --> break at wrchr (always, no condition, same as F2-key)
      wrchr, r0=0d       --> break at wrchr if r0 contains 0dh
      $, [4000006] > 0A0 --> break at cursor if VCOUNT is greater than 0A0h
      $, r4 <= r5        --> break at cursor if r4 is less or equal than r5
      $, [r4] <> [r5]    --> break at cursor if r4 points at other value than r5
      mainloop, ..5      --> break every 5th time that pc gets to mainloop (timer)

The conditions are verified BEFORE the instruction is executed.

      Operators:              Operands:          Timer Identifier:
      ==  =   <   >   &       n   [nn]  r        ..
      !=  <>  <=  >=  !&      nn  [rr]  rr

Operators == and != are pseudonyms for = and <>
Global Conditional Breakpoints
Global breaks are working exactly as above local breaks, except that the condition is verfied after <each> executed opcode. In the Ctrl+B window, enter a condition (without specifying a address). Examples:

      r0 = 0            --> break whenever register r0 becomes zero
      [4000006]>20      --> break whenever VCOUNT becomes greater than 20h

The emulator stops only when a condition changes from false to true, ie. it does not permanently break after each opcode if the condition stays true for a while.
The Break Window
The lower left window of the debug screen is shared for Data and Breakpoints, use TAB-key in this window to switch between Data and Break windows. The Break window lists all defined breakpoints, DEL-key can be used to delete a selected breakpoint. When pressing ENTER on a local breakpoint, the code window will be moved to the break address, this works also for bookmarks (that are non-functional 'dummy' breaks, defined by Alt+B key in code window).
Source Code Breakpoints
The opcode MOV R11,R11 may be used as source code breakpoint (in both THUMB and ARM state). These breaks are working much like normal F2-key breakpoints, except that they may be defined directly in source code by inserting the above opcode. Because the opcode is not changing any registers or flags there will be no conflicts when testing the binary on real hardware.
Note: Source breaks work only if you have enabled them in no$gba setup. To remove a specific source break, move the code-window cursor onto it, and hit the DEL-key (or enter NOP in the online assembler).

Profiling & Performance Monitoring

No$gba includes a couple of features for performance monitoring, allowing to write faster or smoother code, to free up more CPU time for additional effects, or simply to reduce the battery power consumption.
Profiling Features
Profiler Window
Profiler Compatibility
Clock Cycle Comments
Cycle Counters
Related Specifications...
ARM CPU Instruction Cycle Times
GBA Memory Map
GBA System Control
LCD Dimensions and Timings
BIOS Halt Functions

Profiler Window

The Profiler Window (Alt+P key in debug mode) displays execution time and number of calls of all executed procedures. The window is split into Tree, Path, and List tabs. Double-clicking an item in a tab moves the debuggers code window to the selected procedure.
Profiler Tree Tab
Displays all executed procedures with number of calls and execution time, presented as tree view; sub-routines show up as child branches. Useful to find out which procedures have been called how long and at which location(s).
Profiler Path Tab
Displays the current branch of the profiler tree - including any (nested) interrupt branch(es), the currently executed procedure shows up at the bottom. The path is similar to all return addresses on the various isr/irq/svc stacks (and in the LR register) being merged into a single "stack".
Profiler List Tab
Displays all executed procedures, the number of calls, and execution time in separate columns. The table can be sorted by clicking on the column headers.
Clock Cycle Values
The clock cycles can be optionally shown as total number of cycles (since the game was started, or the profiler list has been cleared), or as medium number of cycles per call, or as medium number of cycles per second (the GBA runs at 16,777,216 cycles per second).
Also, clock cycles can be either shown with or without cycles being spent in sub-routines (optionally including or excluding cycles in Halt/IntrWait sub-routines).
IRQs and DMAs
By default, IRQs and sound/video DMAs are shown as root entries in tree. If desired, the setup allows to change the profiler mode to count all IRQs/DMAs as "sub-routines". IRQs/DMAs which will then show up everywhere in the tree where they have occurred. Also, IRQs/DMAs clock cycles are then counted as normal sub-routine time to the interrupted "parent" procedures.
Note: DMAs that are directly started by the CPU (by start immediately timing) are always shown as local "sub-routines".
For more information on how to use the profiler, and how to avoid possible problems, please also read the next chapter,
Profiler Compatibility

Profiler Compatibility

The no$gba profiling mechanism allows the parent routines to include/exclude cycles being spent in sub-routines, and other useful effects like the tree tab which would be impossible with other less advanced profiling mechanisms.
How it works...
During emulation, the no$gba profiler keeps track of the program flow by watching any opcodes which change the program counter. It relies on identifying "call" and "return" opcodes used to enter/leave each procedure, and to ignore other "jump" opcodes used loop/skip inside of a procedure.
Sounds simple, but has been relative difficult to implement because the ARM CPU doesn't actually have clearly defined "call/return/jump" opcodes. Instead, it uses various branch (and load, pop, add, mov) opcodes to do various kinds of jumps to - or from - or inside of procedures (for example, the BX opcode is used for all three purposes).
Flexibility and possible problems
The profiler should be meanwhile quite flexible and should work with most programs. If it doesn't work, then it is probably only because of a few procedures which use unconvential program code. In that case it should be no big deal to solve the problem, either by changing that procedures, or by supporting it in no$gba. Either way, please let me know of <any> problems, and of which opcodes you are using to enter/leave the procedures, and if can solve it yourself by changing the code, or if you need the code to be supported in next no$gba update!
Re-synchronization
The profiler may shortly lose track of the program flow if it has overseen a return opcode from a child procedure to its parent. It will then assume that it is still executing the child (and any further cycles and sub-routines will be incorrectly counted to the child).
However, the profiler will re-synchronize itself to program flow once when it locates a return opcode which jumps to a higher parent procedure, the child routine which didn't have a return opcode will be then shown with a "(?)" question mark in the tree/list tabs.
Below is a summary of currently supported call/ret opcodes and opcode-combinations, useful to identify and report problems, or eventually to solve the problem by making your code compatible with it.
Calls - Entering a sub-routine
Sub-routines are most conventionally entered by a "bl addr" opcode. Calls with thumb/arm mode switches & indirect calls can be implemented by groups of two opcodes. In ARM mode, that'd be a "mov lr,pc" or a "add lr,=retadr" opcode, followed by a "bx rd" or "ldr pc,[jumplist]" opcode. Also, in ARM and THUMB mode, it can be implemented by a "bl addr" opcode which is pointing to a "bx rd" opcode. And, of course, IRQs and SWIs are as well supported.
Returns - Leaving a sub-routine
Standard returns would be "bx lr" or "mov pc,lr" or "pop pc" opcodes (aka "ldmfd [r13]!,pc" aka "ldr pc,[sp],4"). Also, any "bx rd" may be used for returns with thumb/arm mode switch (eg. after a thumb "pop rd"), or if the return address was moved to rd register (instead of saving it on stack). Note: The profiler identifies "bx rd" as return opcode if the current procedure (or any parent procdures) have been called with the same return address as the value in "rd". Finally, IRQs and SWIs may return by "subs/movs pc".
Jumps - Inside of procedures
All other jump opcodes are normally treated as normal jumps without affecting the profiler (unless a return address has been previously written into LR).
CAUTION: Because the normal thumb mode "b" opcode (branch) has relative short range, some programs may use the "bl" opcode (branch long with link) to produce long jumps (with the link register value being ignored/destroyed). The profiler currently treats all "bl" opcodes to be used to enter a sub-routine, not as long jump! Please let me know if that is a problem with your code!
LR - Link Register (R14)
Please always have the return address stored in LR when calling a procedure. And please avoid to use LR (R14) for other purposes, ie. if possible, use only R0-R12 as general purpose data registers.
Multitasking
The profiler memory is organized similar as a stack, and it should be actually running synchronous to the return addresses on the CPU stack. That means that it'd be currently not working with any 'multitasking' programs, ie. programs that switch between different threads, each with a separate stack.
Please let me know if you are doing any such things! I'd love to support it - if anybody wants it. The feature would probably work automatically (without you having anything much more to do than to say "hello, I use multitasking, what I am doing is..."), and it would nicely display each thread as separate root entry in the tree tab, allowing to determine time being spent in each thread (and its sub-routines) very easily...

Clock Cycle Comments

The normal execution time for one GBA opcode ranges between 1 and 100 (!) clock cycles, or more. Unfortunately, opcode execution time depends on various of circumstances (bus widths, waitstates, etc.), which is making it rather difficult to count cycles by hand, or just to a get feeling for efficient GBA code.
The no$gba Clock Cycle Comments feature displays the execution time for each opcode in disassembler window. Four different view modes (selectable in setup) are available:
Short Formula, and Detailed Formula
Short Formula: Displays the Non-sequential, Sequential, and Internal cycles (eg. 2N+3S+1I). Detailed Formula: Splits the N and S cycles into code and data access (eg. 1N+1S+1ND+2SD+1I, N/S for code, ND/SD for data).
Cycles, and Cycles & Sum
Cycles: Displays the number of clock cycles (by resolving the above formula - recursing operand size, opcode and data addresses, and current waitstate configuration). Cycles & Sum: Additionally displays the sum of all opcodes on screen in a second column (to use that feature, simply scroll the first line of interest to topmost screen position).
Even though these features are making it much easier to count cycles, there are still some restrictions which should be kept in mind:
Data access (load/store opcodes) - Important
Cycles are resolved by current register settings. For example, the execution time for "LDR Rd,[Rb]" could be resolved correctly only if Rb is currently pointing to the same memory area as when executing that opcode (that is valid if the program counter points to the opcode, for stack accesses by r13 register it'd be usually always valid).
Prefetch
Game-Pak Prefetch isn't yet understood or supported. If it is enabled in WAITCNT register, access to cartridge ROM may take up less cycles as displayed in clock cycle comments.
Conditional Opcodes
Conditional opcodes are always assumed to be true (unless if the program counter points to the opcode, in that case the actual execution time is displayed, ie. 1S if the condition is false).
Sums
The Cycles & Sums features simply adds one execution time to another, useful for fragments of code, but of course not aware of loops or skips.
Jumps
Execution time for branch opcodes is incorrectly displayed by using local waitstates for local code area (rather than target area). However, intersegment jumps (from one memory area to another) are typically consisting of a call-return combination (ie. the overall execution time would be correct, but the execution times of the call and return opcodes would be exchanged).
VRAM Waitstates
VRAM Waitstates are not displayed (the real hardware would occasionally add 1 cycle for accesses to video memory).

Cycle Counters

Execution Time value in Statusbar
No$gba displays the clock cycles difference between start and stop time in status bar when the emulation gets stopped. For example, hitting F3-key to execute a "BL draw_frame" opcode would display the execution time of the "draw_frame" procedure.
Note: That would also include any interrupts or DMAs which may have been occurred while executing that procedure.
User Counter
The user counter (located in Timers page of I/O map window) is incremented during emulation execution and tracing, the counter can be easily reset to zero by pushing the reset button which is displayed next to it.
Debug Message Counters
The Debug Message feature includes some special operands (%totalclks%, %lastclks%) which allow to write cycle counts to debug message window (or into log file). See Debug Messages chapter for details.
CPU Load Indicator
The "Power Gauge" (the red-green bar in debug window) displays the used CPU time (assuming that the unused CPU time is properly spent in Halt or IntrWait state, which reduces battery power consumption on real hardware). The higher it gets, the more CPU time is used.
By default, CPU load is re-calculated once per frame (60Hz), this rate can be changed in "Other" setup options (useful to prevent flickering with game engines that update the picture only once every two or three frames).
Note: The same information is also displayed as decimal value, in steps of 0.1%, in the Timers page of the I/O map window.
NB. Cycle counters are 32bit values and will overflow (restart at zero) after 4G cycles (256 seconds), which is probably more than enough in most cases.

Debug Messages

Debug Messages can be defined in source code. When the emulator 'executes' a message opcode, the message text will be output to the debug message window and to file DEBUGMSG.TXT. Debug Messages will not disturb execution on real hardware (the branch opcode just skips the data definition, wastes a few clock cycles though).
User Defined Messages
The message definition format (in THUMB or ARM mode) is as follows:

       mov  r12,r12          ;first ID
       b    @@continue       ;branch opcode that skips the message data
       dcw  6464h            ;second ID (ascii 'dd')
       dcw  0                ;reserved for flags
       dcb  'Hello'          ;user defined ascii data (max length 120 bytes)
       dcb  0                ;ending zero (normally not required, see below)
      .align 4               ;align following code (use align 2 in thumb mode)
      @@continue:

The text field is terminated by a zero byte or by the branch destination. The zero byte must be separately defined ONLY if your assembler doesn't zero-pad alignment space.
The ascii string may contain parameters, defined as %param%.

      r0,r1,r2,...,r15  show register content (displayed as 32bit Hex number)
      sp,lr,pc          alias for r13,r14,r15
      scanline          show current scanline number
      frame             show total number of frames since coldboot
      totalclks         show total number of clock cycles since coldboot
      lastclks          show number of cycles since previous lastclks (or zeroclks)
      zeroclks          resets the 'lastclks' counter

In the no$gba built-in A22i assembler, messages may be defined as:

      .msg 'Hello'
      .msg 'Source Addr = %r0% ; Dest Addr = %r1% ; Length = %r2%'
      .msg 'Stack Pointer = %SP%'
      .msg 'Decompression time: %lastclks% cycles'

Messages could be defined as macros when using other assemblers. The %parameters% are stored in ascii format as-is. The assembler/macro does NOT need to interprete and/or adjust the parameters!
See also
Aside from use "mov r12,r12", debug messages can be also output via pseudo I/O ports:
DS Debug Registers (Emulator/Devkits)
3D Log and Wifi Log
Additionally to the User messages, no$gba can also log 3D commands and Wifi packets in the debug message window. The separate message types can be enabled/disabled by checkboxes in the menubar of the window.

Symbolic Debug Info

If debug info (.SYM or .ELF files) has been loaded, labels will be displayed in disassembled code. And input boxes will recognize labels (eg. for Ctrl+G). TAB in code window toggles symbolic display on and off. Moving the code windows cursor onto a line with a symbol displays the value that hides behind the symbol in the upper left corner of the screen (DOS) or in the status bar (Windows).
Also, if source-level debug info is present, no$gba allows the user to view his/her source code in 'stacked' view mode, ie. disassembled opcodes shown below of each source line, this would be important for HLL programs.
.ELF Files (GBA)
Elf files are binaries, generated by many ARM assemblers and compilers (eg. Nintendo Tools, GNU tools). The files are containing the program (binary executable), and optionally also a symbol table & further debug information (usually in Dwarf2 format, and if present, typically containing source-level debug info).
Current no$gba version supports loading the binary (game), and the symbol table (similar content as .SYM files, but without additional code+data info), and the source-level debug information.
There seem to be different interpretations of how to store a binary inside of ELF files - as far as I know no$gba is compatible with all of these 'standards'.
.NEF/.SRL Files (NDS)
Nintendo's DS devkit outputs ROM-image and debug-info to separate files:

      cart.SRL rom-image (without any debug info, same as normal .NDS files)
      cart.NEF the NDS9 debug-info in ELF format (but without program code/data)
      cart.NLF contains a path to another .NEF file with NDS7 debug-info

No$gba v2.2e supports NDS9 debug info, the NDS7 file isn't supported yet.
.SYM Files
When not using ELF files, symbolic Information may be stored in file <cartname>.SYM in the same directory than <cartname>.GBA. The A22i assembler produces ready-for-use SYM files. When using another assembler, you may convert any debug information into .SYM format.
.SYM Symbolic Information File Format:

      ;no$gba symbolic information table example
      08000000 .arm
      080000C0 start
      08000124 mainloop
      080001EC .thumb
      080001EC init_video
      08000210 .arm
      08000210 irq_handler
      08000228 jumplist
      08000228 .dbl:0010
      08000414 text_array
      08000414 .asc:0017
      0800042B .asc:000F
      0800043A .asc:0012
      06000000 vram_base
      ;...

All symbols have to be declared as EIGHT-character string nnnnnnnn (hexadecimal memory address, not case sensitive), followed by at least one space or TAB and then followed by the symbol name (the name may contain any characters except spaces and control codes, names are case-sensitive).
.SYM Additional Code and Data Information
Aside from labels, the file may also contain information about 16bit or 32bt program code areas, and about data zones. This info is stored in the same format as normal labels, but by using the following reserved "labels":

      .arm          ;following code is in 32bit/ARM format
      .thumb        ;following code is in 16bit/THUMB format
      .byt:NNNN     ;next NNNN bytes are 8bit data (dcb lines)
      .wrd:NNNN     ;next NNNN bytes are 16bit data (dcw lines)
      .dbl:NNNN     ;next NNNN bytes are 32bit data (dcd lines)
      .asc:NNNN     ;next NNNN bytes are ascii data (quoted dcb lines)
      .pool         ;dummy label (indicates that following is literal pool)

The entries may be mixed with normal label definitions, NNNN is a hexadecimal value, it is always counted in BYTES (even when defining 16/32 bit data fields).
There is no need to sort the entries in any way. Empty lines are allowed. Lines starting with ";" are ignored as comments. Lines are terminated by LF or CRLF or EOF or filesize. The file is terminated by EOF or filesize.

XED Editor

XED About
XED Hotkeys
XED Assembler/Debugger Interface
XED Commandline based standalone version

XED About

About XED
XED is a text editor, the executable is fast and small, and it includes comfortable editing functions. It is both intended for standard .TXT files (or any other ASCII files, such like .ASM for assembler source code). Also, the line-wrapping support (.XED files) can be used for authoring stories, specifications, etc. Most of the features are much the same as for other text editors, some special functions are pointed out below:
Block Selection
XED supports good old quality block mechanisms, allowing to copy/move the selection directly to cursor position by Ctrl+K,C/V hotkeys (without needing to use paste). For data exchange with other programs or text files, the block can be directly written to (or loaded from) file by Ctrl+K,R/W. And, mainstream copy/cut/paste functions are supported as well, by Ctrl+Ins, Shift+Del, Shift+Ins.
Note: The block remains selected even when typing text, and it won't get deleted when touching Del-key.
Condensed Display Mode
Condensed mode is activated by "F6,C" key combination. In this mode, only lines beginning with colon ":", or (for assembler source code files) with semicolon-colon ";:", for example:

      :Chapter IV
      ;:---Sound Engine---

Normal block functions can be used in this mode to Move, Copy, or Delete whole 'chapter(s)'. Cursor keys can be used to move the cursor to a specific chapter. Pushing Enter or Escape terminates condensed mode.
Column Block Mode
Column mode is activated by "Ctrl+K,N" key combination. In this mode, the block selection appears as a rectangular area, allowing to deal with tables & columns in text files by using copy/delete, indent/unindent block functions.
Typing "Ctrl+K,N" again will return to normal block mode (in which any lines between begin/end of the block will be selected at full length).
Blank Space
Unlike most other editors, XED allows to move the cursor to any screen location, including at horizontal positions after the end of the current line. Entering space characters at such locations advances the cursor position, but does not actually store space characters in the file.
When typing text, spaces are automatically inserted between line-end and cursor position. Respectively, ending spaces are automatically deleted (eg. assume that the line contains "Hello !", deleting "!" will also remove the space character, internally).
That is of course all happening behind your back, you won't have to care about it - but you can be sure that there'll be no hidden spaces filling up disk space.
Tabulation Marks / TAB-Key
The TAB Key advances the cursor to the next higher tabulation location (usually in steps of eight columns, counted from leftmost screen border), and the appropriate number of spaces is inserted into the file if necessary.
In overwrite mode (de-/activated by INS Key), the TAB Key simply advances the cursor without actually inserting spaces (and without overwriting existing text by spaces).
Tabulation Marks / CHR(9)
When enabled in setup (default), TAB marks are automatically expanded into appropriate number of spaces (ie. towards next "8-column" position) when loading a file.
The file is normally saved by using raw SPC characters, without any TABs. Optionally, it can be saved by using "best-fill" SPCs and TABs (disabled by default), that feature may conflict with third party tools (assemblers, compilers, etc). In order to reduce the risk of such problems, best-fill is suppressed in quoted lines (by using ' or " or <> quotation marks, eg. db 'Hello !').
Line Wrapping
Line wrapping is enabled/disabled by "F5+W" key combination. Wrapping is automatically enabled when loading a file with extension ".XED".
In the file, wrapped lines are using CR characters as soft linebreaks, paragraphs are terminated by normal CR,LF characters.
Note: It'd be recommended to convert .XED files into 'standard' formats such like .TXT or .HTM before releasing them, but preferably NOT into disliked bloated file formats such like .PDF or .DOC.
Word Processing
Aside from the above line-wrapping support, no other 'word processing' features are included, the program provides normal 'type writer' functions, not more, not less. In particular, any overload such like bold or colored text, big and small fonts, bitmaps and different fonts are disliked.

XED Hotkeys

XED recognizes both CP/M Wordstar hotkeys (also used by Borland PC compilers), and Norton editor hotkeys (NU.EXE). The "Ctrl+X,Y" style hotkeys are wordstar based, particulary including good block functions. The F4,X and Alt/Ctrl+X type hotkeys are norton based, particulary very useful for forwards/backwards searching.
Standard Cursor Keys

      Up         Move line up
      Down       Move line down
      Left       Move character left
      Right      Move character right
      Pgup       Scroll page up / to top of screen
      Pgdn       Scroll page down / to bottom of screen
      Ctrl+Pgup  Go to start of file (or Ctrl+Home)
      Ctrl+Pgdn  Go to end of file (or Ctrl+End)
      Home       Go to start of line
      End        Go to end of line
      Ctrl+Left  Move word left
      Ctrl+Right Move word right
      Ins        Toggle Insert/Overwrite mode
      Del        Delete char below cursor
      Backspace  Delete char left of cursor
      Tab        Move to next tabulation mark
      Enter      New line/paragraph end
      Esc        Quit (or Alt+X, F3+Q, Ctrl+K+D, Ctrl+K+Q, Ctrl+K+X)

Note: Pgup/Pgdn are moving the cursor to top/bottom of screen, page scrolling takes place only if the cursor was already at that location.
Editor Keys

      Ctrl+Y     Delete line (or Alt+K)
      Alt+L      Delete to line end (or Ctrl+Q,Y)
      Alt+V      Caseflip to line end
      Ctrl+V     Caseflip from line beginning

Norton Search/Replace Functions

      Alt+F      Norton - search/replace, forwards
      Ctrl+F     Norton - search/replace, backwards
      Alt+C      Norton - continue search/replace, forwards
      Ctrl+C     Norton - continue search/replace, backwards

Search: Type "Alt/Ctrl+F, String, Enter".
Search+replace: "Type Alt/Ctrl+F, String1, Alt+F, String2, Enter".
Non-case sensitive: Terminate by Escape instead of Enter.
Wordstar Search/Replace Functions

      Ctrl+Q,F   Wordstar - search
      Ctrl+Q,A   Wordstar - replace
      Ctrl+L     Wordstar - continue search/replace

Search options: B=Backwards, G=Global, N=No query,
U=non-casesensitive, W=whole words only, n=n times.
Disk Commands

      F3,E       Save+exit
      F3,S       Save (or Ctrl+K,S)
      F3,N       Edit new file
      F3,A       Append a file

See also: Block commands (read/write block).
Block Selection

      Shift+Cursor  Select block begin..end
      Ctrl+K,B   Set block begin (or F4,S)
      Ctrl+K,K   Set block end   (or F4,S)
      Ctrl+K,H   Remove/hide block markers (or F4,R)
      F4,L       Mark line including ending CRLF (or Ctrl+K,L)
      F4,E       Mark line excluding ending CRLF
      Ctrl+K,T   Mark word
      Ctrl+K,N   Toggle normal/column blocktype

Clipboard Commands

      Shift+Ins  Paste from Clipboard
      Shift+Del  Cut to Clipboard
      Ctrl+Ins   Copy to Clipboard
      Ctrl+Del   Delete Block

Block Commands

      Ctrl+K,C   Copy block (or F4,C)
      Ctrl+K,V   Move block (or F4,M)
      Ctrl+K,Y   Delete block (or F4,D)
      Ctrl+K,P   Print block  (or F7,B)
      Ctrl+Q,B   Find block begin (or F4,F)
      Ctrl+Q,K   Find block end   (or F4,F)
      Ctrl+K,R   Read block from disk towards cursor location
      Ctrl+K,W   Write block to disk
      Ctrl+K,U   Unindent block (delete one space at begin of each line)
      Ctrl+K,I   Indent block (insert one space at begin of each line)
      F5,F       Format block (with actual x-wrap size) (or ;Ctrl+B)
      F8,A       Add values within column-block

Setup Commands

      F11        Setup menu (or F8,S)
      F5,S       Save editor configuration
      F5,L       Set line len for word wrap (or Ctrl+O,R)
      F5,W       Wordwrap on/off (or Ctrl+O,W) (*)
      F5,I       Auto indent on/off (or Ctrl+O,I)
      F5,T       Set tab display spacing

(*) Wrapped lines will be terminated by CR, paragraphs by CRLF.
Other

      F1         Help
      F2         Status (displays info about file & currently selected block)
      F8,M       Make best fill tabs
      F8,T       Translate all tabs to spaces
      SrcLock    Freeze cursor when typing text ("useful" for backwards writing)
      Ctrl+O,C   Center current line
      Ctrl+K,#   Set marker (#=0..9)
      Ctrl+Q,#   Move to marker (#=0..9)
      Ctrl+Q,P   Move to previous pos
      F6,C       Condensed display mode on/off (*)
      Ctrl+G     Go to line nnnn (or F6,G) (or commandline switch /l:nnnn)

(*) only lines starting with ':' or ';:' will be displayed. cursor and block commands can be used (e.g. to copy a text-sequence by just marking it's headline)
Hex-Edit Keys (Binary Files)
This mode is activated by /b commandline switch, allowing to view and modify binary files. Aside from normal cursor keys, the following hotkeys are used:

      Tab        Toggle between HEX and ASC mode (or Shift+Left/Right)
      Ctrl+Arrow Step left/right one full byte (instead one single HEX digit)
      Ctrl+G     Goto hex-address
      Ctrl+K,S   Save file (as usually)

Printer Commands

      F7,P       Print file
      F7,B       Print block (or Ctrl+K,P)
      F7,E       Eject page
      F7,S       Set page size

More printer options can be found in setup. Printing was working well (at least with my own printer) in older XED versions, but it is probably badly bugged (at least untested) for years now.

XED Assembler/Debugger Interface

Nocash Debuggers
The XED editor provides simple but very useful interaction with the various nocash debuggers/emulators (no$gba, no$gmb, no$cpc, no$msx, no$c64, no$2k6, no$zx, no$nes, no$sns, no$x51).
The editor can be launched from inside of the debugger (by Alt+E hotkey, by retaining the recently edited line number when re-launching the editor).
And, when editing assembler source code files, F9-key can used to launch the assembler from inside of XED. That is, the file is saved to disk, the A22i assembler is started (built-in in all debuggers), and, in case of successful assembly, the program is loaded & started in the emulator. Otherwise, the assembler displays a list of errors, and the editor is moved directly to the source code line number in which the first error has occured.
16bit DOS debuggers
The XED editor is included built-in in all nocash windows debuggers, and in the no$gba 32bit DOS version only.
For use with other nocash 16bit DOS debuggers the XED editor must be downloaded separately at http://problemkaputt.de/xed.htm, and must be installed in a directory which is included in your PATH statement.

XED Commandline based standalone version

Standalone 16bit DOS version
This version is written in turbo pascal, nevertheless fast enough to work on computer with less than 10MHz. It uses 16bit 8086 code, and works with all 80x86 compatible CPUs, including very old XTs.
The downside is that it is restricted to Conventional DOS Memory, so that the maximum filesize is 640K (actually less, because the program and operating system need to use some of that memory).
Using the 32bit debugger-built-in version as 32bit standalone editor
I haven't yet compiled a 32bit standalone version, however, any of the no$xxx 32bit debuggers can be used for that purpose. By commandline input:

      no$xxx /x <filename>   Edit text file in standalone mode
      no$xxx /b <filename>   Edit binary file in standalone hexedit mode

Standalone Commandline Syntax
Syntax: XED <filename> [/l:<line number>] | /?

      <name>    Filename, optionally d:\path\name.ext
      /?        Displays commandline help
      /l:<nnn>  Moves to line number nnn after loading

The filename does not require to include an extension, the program automatically loads the first existing file with any of following extensions appended: XED, ASM, ASC, INC, BAT, TXT, HTM, DOC, A22, PAS.
Standalone DOS Return Value
XED returns a three-byte return value after closing the program. This data is used when calling XED as external editor from inside of nocash DOS debuggers, but it might be also useful for other purposes.
Because normal DOS return values are limited to 8bits only, the three bytes are written into video RAM at rightmost three character locations in first line:

      VSEG:77*2  Exit code   (00h=Exit normal, F9h=Exit by F9-key)
      VSEG:78*2  Line number (Lower 8bits, 1..65536 in total)
      VSEG:79*2  Line number (Upper 8bits)

The color attribute for these characters is set to zero (invisible, black on black). Use INT 10h/AH=0Fh to determine the current video mode (AL AND 7Fh), if it is monochrome (07h) then use VSEG=B000h, otherwise VSEG=B800h.

The A22i Assembler

Online Assembler
In the debuggers code window, you can directly enter assembler instructions and modify the program code. The assembler input box shows up automatically when typing the first character of the new instruction.
The most basic purpose would be to overwrite an opcode by typing "NOP", but you could also enter any other instruction, such like "ADD R0,R0,4" when having debug info (.sym file) loaded, you may also use labels as parameters, eg. "B mainloop". The pseudo opcode "LDR Rd,=Imm" can be used only under certain circumstances:
Using LDR Rd,=Imm in Online Assembler
Note: Aside from translating machine code instructions, the assembler input box can be also used to change the value of CPU registers, by typing "r0=12345678", or "sp=3007FF0" for example. For curiosity, it also parses simple commands such like: run, reload, help, exit, date, etc.
Source Code Assembler
The assembler can be also used to assemble source code files, by using the Assemble File function in Utility menu. This function has been mostly implemented for my own pleasure, and because I didn't wanted to install thirdparty tools on my computer. It's having some nice features, but it's also lacking some possibly important functions (see below).
A22i Advantages
It's easy to use, very fast, produces ready-for-use debug info .sym files, it understands official ARM syntax, as well as more reasonable cleaned-up syntax, and also different assembler dialects, directives, and numeric formats, it can be used directly from inside of the debugger (and from inside of the editor), and vice-versa: it's able call the editor in case of assembly errors.
A22i Disadvantages
The main disadvantage is that A22i isn't supporting macros (yet).
A22i is a Matter of Taste
If you want to use linkers, make files, project files, header files, command files, resource files, script files, libraries, high level languages, strip commands, object files, and cathode ray tube (crt) files - forget about it!
A22i translates a source code file into a binary file, not more, not less.
For more info about instruction set and directives, see:
ARM CPU Reference
ARM Pseudo Instructions and Directives
Sample Code
For a source code example, have a look at the Magic Floor game at the no$gba webpage, the package includes the binary, source code, with comments, and .sym debug info file.
http://problemkaputt.de/magicflr.htm

Using LDR Rd,=Imm in Online Assembler

LDR{cond} Rd,=Imm is a pseudo opcode, consisting of a LDR Rd,[PC,disp] opcode, and a 32bit immediate at [PC+disp] in the literal pool. The pool is normally generated when assembling the source code, however, additional pool values can be eventually squeezed into the final binary:
1) If the cursor points to an existing LDR=IMM, then it can be overwritten it by a new LDR=IMM, with changed {cond}, changed Rd, or changed Imm. In the latter case, if the immediates pool entry is shared with other LDR=IMMs, then the value of those opcodes will get changed as well - if you wish to suppress that behaviour: First overwrite the old LDR=IMM by NOP, then overwrite it again by new LDR=IMM, which will then (try to) use below mechanisms...
2) If the cursor does NOT point to an existing LDR=IMM, then no$gba will search nearby memory for usable addresses - A) a 32bit value that matches the desired immediate, B) a word-aligned 32bit value containing ascii letters "fREE", which you may want to insert here and there in your code, or C) a presumably unused blank memory area of at least 256 bytes which is 00h- or FFh-filled.
3) If the debugged program was written in C or C++ then you can probably replace some of the meaningless opcodes by hand. For example, to load a 16bit immediate with ARM code: MOV Rd,LSB, ADD Rd,MSB.

About this Document

About
GBATEK written 2001-2014 by Martin Korth, programming specs for the GBA and NDS hardware, I've been trying to keep the specs both as short as possible, and as complete as possible. The document is part of the no$gba debuggers built-in help text.
Updates
The standalone docs in TXT and HTM format are updated when having added any major changes to the document. The no$gba built-in version will be updated more regularly, including for minor changes, along with all no$gba updates.
Homepage
http://problemkaputt.de/gba.htm - no$gba emulator homepage (freeware)
http://problemkaputt.de/gba-dev.htm - no$gba debugger homepage
http://problemkaputt.de/gbapics.htm - no$gba debugger screenshots
http://problemkaputt.de/gbatek.htm - gbatek html version
http://problemkaputt.de/gbatek.txt - gbatek text version
Feedback
If you find any information in this document to be misleading, incomplete, or incorrect, please say something! My spam-shielded email address is found at:
http://problemkaputt.de/email.htm - contact
Mail from programmers only, please. No gaming questions, thanks.
Credits
Thanks for GBATEK fixes, and for info about GBA and NDS hardware,
- Jasper Vijn
- Remi Veilleux (DS video details)
- Randy Linden
- Sebastian Rasmussen
- Stephen Stair (DS Wifi)
- Cue (DS Firmware bits and bytes)
- Tim Seidel (DS Wifi RF2958 datasheet)
- Damien Good (DS Bios Dumping, and lots of e-Reader info)
- Kenobi and Dualscreenman (lots of ARDS/CBDS cheat info)
- Flubba (GBA X/Y-Axis tilt sensor, and GBA Gameboy Player info)
- DarkFader (DS Key2)
- Dstek by neimod (DS Sound)
- Christian Auby
- Jeff Frohwein
- NDSTech Wiki, http://www.bottledlight.com/ds/ (lots of DS info)
- wwylele (xpertteak cpu and mmio findings)
Formatting
TXT is 80 columns, TXT is 80 columns, TXT is 80 columns.
Don't trust anything else. Never.

Index

Contents
GBA Reference
GBA Technical Data
GBA Memory Map
GBA I/O Map
GBA LCD Video Controller
LCD I/O Display Control
LCD I/O Interrupts and Status
LCD I/O BG Control
LCD I/O BG Scrolling
LCD I/O BG Rotation/Scaling
LCD I/O Window Feature
LCD I/O Mosaic Function
LCD I/O Color Special Effects
LCD VRAM Overview
LCD VRAM Character Data
LCD VRAM BG Screen Data Format (BG Map)
LCD VRAM Bitmap BG Modes
LCD OBJ - Overview
LCD OBJ - OAM Attributes
LCD OBJ - OAM Rotation/Scaling Parameters
LCD OBJ - VRAM Character (Tile) Mapping
LCD Color Palettes
LCD Dimensions and Timings
GBA Sound Controller
GBA Sound Channel 1 - Tone & Sweep
GBA Sound Channel 2 - Tone
GBA Sound Channel 3 - Wave Output
GBA Sound Channel 4 - Noise
GBA Sound Channel A and B - DMA Sound
GBA Sound Control Registers
GBA Comparison of CGB and GBA Sound
GBA Timers
GBA DMA Transfers
GBA Communication Ports
SIO Normal Mode
SIO Multi-Player Mode
SIO UART Mode
SIO JOY BUS Mode
SIO General-Purpose Mode
SIO Control Registers Summary
GBA Wireless Adapter
GBA Wireless Adapter Games
GBA Wireless Adapter Login
GBA Wireless Adapter Commands
GBA Wireless Adapter Component Lists
GBA Infrared Communication
GBA Keypad Input
GBA Interrupt Control
GBA System Control
GBA GamePak Prefetch
GBA Cartridges
GBA Cartridge Header
GBA Cartridge ROM
GBA Cart Backup IDs
GBA Cart Backup SRAM/FRAM
GBA Cart Backup EEPROM
GBA Cart Backup Flash ROM
GBA Cart Backup DACS
GBA Cart I/O Port (GPIO)
GBA Cart Real-Time Clock (RTC)
GBA Cart Solar Sensor
GBA Cart Tilt Sensor
GBA Cart Gyro Sensor
GBA Cart Rumble
GBA Cart e-Reader
GBA Cart e-Reader Overview
GBA Cart e-Reader I/O Ports
GBA Cart e-Reader Dotcode Format
GBA Cart e-Reader Data Format
GBA Cart e-Reader Program Code
GBA Cart e-Reader API Functions
GBA Cart e-Reader VPK Decompression
GBA Cart e-Reader Error Correction
GBA Cart e-Reader File Formats
GBA Cart Unknown Devices
GBA Cart Protections
GBA Flashcards
GBA Cheat Devices
GBA Cheat Codes - General Info
GBA Cheat Codes - Codebreaker/Xploder
GBA Cheat Codes - Gameshark/Action Replay V1/V2
GBA Cheat Codes - Pro Action Replay V3
GBA Gameboy Player
GBA Unpredictable Things
NDS Reference
DS Technical Data
DS I/O Maps
DS Memory Maps
DS Memory Control
DS Memory Control - Cache and TCM
DS Memory Control - Cartridges and Main RAM
DS Memory Control - WRAM
DS Memory Control - VRAM
DS Memory Control - BIOS
DS Memory Timings
DS Video
DS Video Stuff
DS Video BG Modes / Control
DS Video OBJs
DS Video Extended Palettes
DS Video Capture and Main Memory Display Mode
DS Video Display System Block Diagram
DS Files - 2D Video
DS Files - 3D Video (mostly unknown)
DS Files - 3D Video BMD0 (Model Data)
DS Files - 3D Video BTX0 (Texture)
DS Files - 3D Video BCA0 (Character Skeletal Animation)
DS Files - 3D Video BTP0/BTA0/BMA0/NVA0 (Unknown Animations)
DS Files - Sound (SDAT etc.)
DS 3D Video
DS 3D Overview
DS 3D I/O Map
DS 3D Display Control
DS 3D Geometry Commands
DS 3D Matrix Load/Multiply
DS 3D Matrix Types
DS 3D Matrix Stack
DS 3D Matrix Examples (Projection)
DS 3D Matrix Examples (Rotate/Scale/Translate)
DS 3D Matrix Examples (Maths Basics)
DS 3D Polygon Attributes
DS 3D Polygon Definitions by Vertices
DS 3D Polygon Light Parameters
DS 3D Shadow Polygons
DS 3D Texture Attributes
DS 3D Texture Formats
DS 3D Texture Coordinates
DS 3D Texture Blending
DS 3D Toon, Edge, Fog, Alpha-Blending, Anti-Aliasing
DS 3D Status
DS 3D Tests
DS 3D Rear-Plane
DS 3D Final 2D Output
DS Sound
DS Sound Channels 0..15
DS Sound Control Registers
DS Sound Capture
DS Sound Block Diagrams
DS Sound Notes
DS Sound Files - SDAT (Sound Data Archive)
DS Sound Files - SSEQ (Sound Sequence)
DS Sound Files - SSAR (Sound Sequence Archive)
DS Sound Files - SBNK (Sound Bank)
DS Sound Files - SWAR (Sound Wave Archive)
DS Sound Files - SWAV (Sound Wave Data)
DS Sound Files - STRM (Sound Wave Stream)
DS System and Built-in Peripherals
DS DMA Transfers
DS Timers
DS Interrupts
DS Maths
DS Inter Process Communication (IPC)
DS Keypad
DS Absent Link Port
DS Real-Time Clock (RTC)
DS Serial Peripheral Interface Bus (SPI)
DS Touch Screen Controller (TSC)
DS Power Control
DS Power Management Device
DS Main Memory Control
DS Backwards-compatible GBA-Mode
DS Debug Registers (Emulator/Devkits)
DS Cartridges, Encryption, Firmware
DS Cartridge Header
DS Cartridge Secure Area
DS Cartridge Icon/Title
DS Cartridge Protocol
DS Cartridge Backup
DS Cartridge I/O Ports
DS Cartridge NitroROM and NitroARC File Systems
DS Cartridge PassMe/PassThrough
DS Cartridge GBA Slot
DS Cart Rumble Pak
DS Cart Slider with Rumble
DS Cart Expansion RAM
DS Cart Unknown Extras
DS Cart Cheat Action Replay DS
DS Cart Cheat Codebreaker DS
DS Cart DLDI Driver
DS Cart DLDI Driver - Guessed Address-Adjustments
DS Encryption by Gamecode/Idcode (KEY1)
DS Encryption by Random Seed (KEY2)
DS Firmware Serial Flash Memory
DS Firmware Header
DS Firmware Wifi Calibration Data
DS Firmware Wifi Internet Access Points
DS Firmware User Settings
DS Firmware Extended Settings
DS File Formats
DS Files - Text Messages (MESG)
DS Files - Text Manuals
DS Wireless Communications
DS Wifi I/O Map
DS Wifi Control
DS Wifi Interrupts
DS Wifi Power-Down Registers
DS Wifi Receive Control
DS Wifi Receive Buffer
DS Wifi Receive Statistics
DS Wifi Transmit Control
DS Wifi Transmit Buffers
DS Wifi Transmit Errors
DS Wifi Status
DS Wifi Timers
DS Wifi Multiplay Master
DS Wifi Multiplay Slave
DS Wifi Configuration Ports
DS Wifi Baseband Chip (BB)
DS Wifi RF Chip
DS Wifi RF9008 Registers
DS Wifi Unknown Registers
DS Wifi Unused Registers
DS Wifi Initialization
DS Wifi Flowcharts
DS Wifi Hardware Headers
DS Wifi Nintendo Beacons
DS Wifi Nintendo DS Download Play
DS Wifi IEEE802.11 Frames
DS Wifi IEEE802.11 Managment Frames (Type=0)
DS Wifi IEEE802.11 Control and Data Frames (Type=1 and 2)
DS Wifi WPA/WPA2 Handshake Messages (EAPOL)
DS Wifi WPA/WPA2 Keys and MICs
DS Wifi WPA/WPA2 Encryption
DS Wifi FFC ID
DS Wifi Dslink/Wifiboot Protocol
DS Xboo
DSi Reference
DSi Basic Differences to NDS
DSi I/O Map
DSi Control Registers (SCFG)
DSi XpertTeak (DSP)
DSi Teak Misc
DSi Teak I/O Ports (on ARM9 Side)
DSi Teak MMIO - Register Summary
DSi Teak MMIO[8000h] - Misc Registers (JAM/GLUE)
DSi Teak MMIO[8020h] - Timers (TMR)
DSi Teak MMIO[8050h] - Serial Port (SIO)
DSi Teak MMIO[8060h] - Debug (OCEM, On-chip Emulation Module)
DSi Teak MMIO[8080h] - PLL and Power (PMU, Power Management Unit)
DSi Teak MMIO[80C0h] - Host Port Interface (APBP aka HPI)
DSi Teak MMIO[80E0h] - AHBM - Advanced High Performance Bus Master
DSi Teak MMIO[8100h] - Memory Interface Unit (MIU)
DSi Teak MMIO[8140h] - Code Replacement Unit (CRU)
DSi Teak MMIO[8180h] - Direct Memory Access (DMA)
DSi Teak MMIO[8200h] - Interrupt Control Unit (ICU)
DSi Teak MMIO[8280h] - Audio (Buffered Time Division Multiplexing Port)
DSi Teak CPU Registers
DSi Teak CPU Control/Status Registers
DSi Teak CPU Address Config/Step/Modulo
DSi TeakLite II Instruction Set Encoding
DSi TeakLite II Operand Encoding
DSi New Shared WRAM (for ARM7, ARM9, DSP)
DSi New DMA (NDMA)
DSi Microphone and SoundExt
DSi Advanced Encryption Standard (AES)
DSi AES I/O Ports
DSi AES Little-Endian High Level Functions
DSi AES Little-Endian Core Function and Key Schedule
DSi AES Little-Endian Tables and Test Values
DSi AES Big-Endian High Level Functions
DSi AES Big-Endian Core Function and Key Schedule
DSi AES Big-Endian Tables and Test Values
DSi ES Block Encryption
DSi Cartridge Header
DSi Touchscreen/Sound Controller
DSi Touchscreen Access
DSi Touchscreen/Sound Init Flowcharts
DSi TSC, Register Summary
DSi TSC[0:00h..1Ah], Basic PLL and Timing Control
DSi TSC[0:1Bh..23h], Codec Control
DSi TSC[0:24h..32h], Status and Interrupt Flags
DSi TSC[0:33h..3Bh], Pin Control
DSi TSC[0:3Ch..55h], DAC/ADC and Beep
DSi TSC[0:56h..7Fh], AGC and ADC
DSi TSC[1:xxh], DAC and ADC Routing, PGA, Power-Controls and MISC Logic
DSi TSC[3:xxh], Touchscreen/SAR Control and TSC[FCh:xxh], Buffer
DSi TSC[04h..05h:xxh], ADC Digital Filter Coefficient RAM
DSi TSC[08h..0Fh:xxh], DAC Digital Filter Coefficient RAM
DSi TSC[20h..2Bh:xxh], TSC[40h..5Fh:xxh] ADC/DAC Instruction RAM
DSi I2C Bus
DSi I2C I/O Ports
DSi I2C Signals
DSi I2C Device 4Ah (BPTWL chip)
DSi Autoload on Warmboot
DSi Aptina Camera Initialization
DSi Aptina Camera Registers: SYSCTL (0000h-0051h)
DSi Aptina Camera Registers: RX_SS, FUSE, XDMA (0100h-099Fh)
DSi Aptina Camera Registers: CORE (3000h-31FFh, 38xxh)
DSi Aptina Camera Registers: SOC1 (3210h-33FDh)
DSi Aptina Camera Registers: SOC2 (3400h-3729h)
DSi Aptina Camera Variables: RAM/SFR/MON (GPIO/Monitor) (MCU:0000h-20xxh)
DSi Aptina Camera Variables: SEQ (Sequencer) (MCU:21xxh)
DSi Aptina Camera Variables: AE (Auto Exposure) (MCU:22xxh)
DSi Aptina Camera Variables: AWB (Auto White Balance) (MCU:23xxh)
DSi Aptina Camera Variables: FD (Anti-Flicker) (MCU:24xxh)
DSi Aptina Camera Variables: MODE (Mode/Context) (MCU:27xxh)
DSi Aptina Camera Variables: HG (Histogram) (MCU:2Bxxh)
DSi Alternate Cameras from Unknown Manufacturer
DSi Cameras
DSi SD/MMC Protocol and I/O Ports
DSi SD/MMC I/O Ports: Command/Param/Response/Data
DSi SD/MMC I/O Ports: Interrupt/Status
DSi SD/MMC I/O Ports: Control Registers
DSi SD/MMC I/O Ports: Unknown/Unused Registers
DSi SD/MMC I/O Ports: Misc
DSi SD/MMC Protocol: Command/Response/Register Summary
DSi SD/MMC Protocol: General Commands
DSi SD/MMC Protocol: Block Read/Write Commands
DSi SD/MMC Protocol: Special Extra Commands
DSi SD/MMC Protocol: CSR Register (32bit Card Status Register)
DSi SD/MMC Protocol: SSR Register (512bit SD Status Register)
DSi SD/MMC Protocol: OCR Register (32bit Operation Conditions Register)
DSi SD/MMC Protocol: CID Register (128bit Card Identification)
DSi SD/MMC Protocol: CSD Register (128bit Card-Specific Data)
DSi SD/MMC Protocol: CSD Register (128bit Card-Specific Data) Version 2.0
DSi SD/MMC Protocol: EXT_CSD Register (4096bit Extended CSD Register) (MMC)
DSi SD/MMC Protocol: RCA Register (16bit Relative Card Address)
DSi SD/MMC Protocol: DSR Register (16bit Driver Stage Register) (Optional)
DSi SD/MMC Protocol: SCR Register (64bit SD Card Configuration Register)
DSi SD/MMC Protocol: PWD Register (128bit Password plus 8bit Password len)
DSi SD/MMC Protocol: State
DSi SD/MMC Protocol: Signals
DSi SDIO Special SDIO Commands
DSi SDIO Memory and I/O Maps
DSi SDIO Common Control Registers (CCCR)
DSi SDIO Function Basic Registers (FBR)
DSi SDIO Card Information Structures (CIS)
DSi SD/MMC Filesystem
DSi SD/MMC Partition Table (aka Master Boot Record aka MBR)
DSi SD/MMC Filesystem (FAT)
DSi SD/MMC Internal NAND Layout
DSi SD/MMC Bootloader
DSi SD/MMC Device List
DSi SD/MMC Complete List of SD/MMC Files/Folders
DSi SD/MMC Summary of SD/MMC Files/Folders
DSi SD/MMC Images
DSi SD/MMC DSiware Files on Internal eMMC Storage
DSi SD/MMC DSiware Files on External SD Card (.bin aka Tad Files)
DSi SD/MMC DSiware Files from Nintendo's Server
DSi SD/MMC DSiware Tickets and Title metadata
DSi SD/MMC Firmware dev.kp and cert.sys Certificate Files
DSi SD/MMC Firmware Certificate/Keys (DER)
DSi SD/MMC Firmware Font File
DS Cartridge Nitro Font Resource Format
LZ Decompression Functions
LZ Decompression Functions ASH0
ZIP Decompression
Inflate - Core Functions
Inflate - Initialization & Tree Creation
Inflate - Headers and Checksums
DS Encrypted Arika Archives with ALZ1 compression
DSi SD/MMC Firmware Log Files
DSi SD/MMC Firmware Misc Files
DSi SD/MMC Firmware Wifi Firmware
DSi SD/MMC Firmware System Settings Data Files
DSi SD/MMC Firmware Version Data File
DSi SD/MMC Firmware Nintendo DS Cart Whitelist File
DSi SD/MMC Camera Files - Overview
DSi SD/MMC Camera Files - JPEG's
DSi SD/MMC Camera Files - pit.bin
DSi SD/MMC Flipnote Files
DSi Atheros Wifi SDIO Interface
DSi Atheros Wifi SDIO Function 0 Register Summary
DSi Atheros Wifi SDIO Function 1 Register Summary
DSi Atheros Wifi - SDIO Function 1 I/O - mbox_wlan_host_reg
DSi Atheros Wifi Misc
DSi Atheros Wifi - Command Summary
DSi Atheros Wifi - Response Summary
DSi Atheros Wifi - Host Interest Area in RAM
DSi Atheros Wifi - BMI Bootloader Commands
DSi Atheros Wifi - MBOX Transfer Headers
DSi Atheros Wifi - WMI Misc Commands
DSi Atheros Wifi - WMI Misc Events
DSi Atheros Wifi - WMI Connect Functions
DSi Atheros Wifi - WMI Channel and Cipher Functions
DSi Atheros Wifi - WMI Scan Functions
DSi Atheros Wifi - WMI Bit Rate Functions
DSi Atheros Wifi - WMI Threshold Functions
DSi Atheros Wifi - WMI Error, Retry and Debug Functions
DSi Atheros Wifi - WMI Priority Stream Functions
DSi Atheros Wifi - WMI Roam Functions
DSi Atheros Wifi - WMI Power Functions
DSi Atheros Wifi - WMI Statistics Function
DSi Atheros Wifi - WMI Bluetooth Coexistence (older AR6002)
DSi Atheros Wifi - WMI Wake on Wireless (WOW) Functions
DSi Atheros Wifi - WMI General Purpose I/O (GPIO) Functions
DSi Atheros Wifi - Unimplemented WMI Misc Functions
DSi Atheros Wifi - Unimplemented WMI Bluetooth Coexistence (newer AR6002)
DSi Atheros Wifi - Unimplemented WMI Bluetooth Coexistence (AR6003)
DSi Atheros Wifi - Unimplemented WMI DataSet Functions
DSi Atheros Wifi - Unimplemented WMI AP Mode Functions (exists on 3DS)
DSi Atheros Wifi - Unimplemented WMI DFS Functions
DSi Atheros Wifi - Unimplemented WMI P2P Functions
DSi Atheros Wifi - Unimplemented WMI WAC Functions
DSi Atheros Wifi - Unimplemented WMI RF Kill and Store/Recall Functions
DSi Atheros Wifi - Unimplemented WMI THIN Functions
DSi Atheros Wifi - Unimplemented WMI Pyxis Functions
DSi Atheros Wifi I2C EEPROM
DSi Atheros Wifi Internal Hardware
DSi Atheros Wifi - Xtensa CPU Registers
DSi Atheros Wifi - Xtensa CPU Core Opcodes
DSi Atheros Wifi - Xtensa CPU Optional General Opcodes
DSi Atheros Wifi - Xtensa CPU Optional Exception/Cache/MMU Opcodes
DSi Atheros Wifi - Xtensa CPU Optional Floating-Point Opcodes
DSi Atheros Wifi - Xtensa CPU Optional MAC16 Opcodes
DSi Atheros Wifi - Xtensa CPU Opcode Encoding Tables
DSi Atheros Wifi - Internal Memory Map
DSi Atheros Wifi - Internal I/O Map Summary (hw2)
DSi Atheros Wifi - Internal I/O Map Summary (hw4)
DSi Atheros Wifi - Internal I/O Map Summary (hw6)
DSi Atheros Wifi - Internal I/O - Unknown and Unused Registers (hw2)
DSi Atheros Wifi - Internal I/O - 004000h - RTC/Clock SOC (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 00x000h - RTC/Clock WLAN (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 0xx240h - RTC/Clock SYNC (hw6)
DSi Atheros Wifi - Internal I/O - 006000h - WLAN Coex (MCI) (hw6)
DSi Atheros Wifi - Internal I/O - 00x000h - Bluetooth Coex (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 00x000h - Memory Control (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 00C000h - Serial UART (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 00E000h - UMBOX Registers (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 010000h - Serial I2C/SPI (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 014000h - GPIO 18/26/57 pin (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 018000h - MBOX Registers (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 01C000h - Analog Intf (hw2)
DSi Atheros Wifi - Internal I/O - 01C000h - Analog Intf (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 020000h - WMAC DMA (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 020080h - WMAC IRQ Interrupt (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 020800h - WMAC QCU Queue (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 021000h - WMAC DCU (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 028000h - WMAC PCU (hw2/hw4/hw6)
DSi Atheros Wifi - Internal I/O - 029800h - BB Baseband (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 0xxx00h - RDMA Registers (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 03x000h - EFUSE Registers (hw4/hw6)
DSi Atheros Wifi - Internal I/O - 034000h - More Stuff (hw6)
DSi GPIO Registers
DSi Console IDs
DSi Unknown Registers
DSi Notes
DSi Exploits
DSi Regions
3DS Reference
3DS Memory and I/O Map
3DS MISC Registers
3DS GPIO Registers
3DS Crypto Registers
3DS Crypto - AES Registers
3DS Crypto - SHA Registers
3DS Crypto - RSA Registers
3DS Crypto - PRNG and OTP Registers
3DS Crypto - AES Keyslots
3DS Crypto - AES Key Generator
3DS Crypto - RSA sighax
3DS DMA Registers
3DS DMA - NDMA Registers
3DS DMA - Corelink DMA Peripheral IDs
3DS DMA - Corelink DMA Register Summary
3DS DMA - Corelink DMA - Interrupt and Fault Status Registers
3DS DMA - Corelink DMA - Internal State Status Registers
3DS DMA - Corelink DMA - Transfer Start (aka "Debug" Registers)
3DS DMA - Corelink DMA - Fixed Configuration and ID Registers
3DS DMA - Corelink DMA Opcode Summary
3DS Config Registers
3DS Config - CONFIG9 Registers
3DS Config - CONFIG11 Registers
3DS Config - AXI Registers
3DS Config - L2C-310 Level 2 Cache Controller (New3DS)
3DS Config - ARM7 Registers (GBA/NDS/DSi Mode)
3DS SPI and I2C Bus
3DS SPI Registers
3DS SPI Devices
3DS TSC, Register Summary
3DS I2C Registers
3DS I2C Device List
3DS I2C MCU Register Summary
3DS I2C MCU[00h-01h,05h-07h] - Firmware
3DS I2C MCU[02h-0Fh] - Status
3DS I2C MCU[10h-1Fh] - Interrupt Flags
3DS I2C MCU[20h-24h] - Power Control
3DS I2C MCU[28h-2Eh] - LED Control
3DS I2C MCU[30h-3Fh] - Real-Time Clock (RTC)
3DS I2C MCU[40h-51h] - Accelerometer/Pedometer
3DS I2C MCU[60h-7Fh] - Misc Status
3DS I2C MCU secondary I2C Devices (on MCU bus)
3DS I2C MCU - RL78 Flash Programming via UART
3DS I2C MCU - RL78 CPU Opcode List
3DS I2C MCU - RL78 CPU Opcode Map
3DS I2C MCU - RL78 CPU Registers and Flags
3DS I2C MCU - RL78 SFR Registers (Special Function Registers) (I/O ports)
3DS I2C MCU - RL78 Misc
3DS I2C Gyroscope (old version)
3DS I2C Gyroscope (new version)
3DS I2C Infrared Receiver/Transmitter (IrDA)
3DS I2C LCD Screen Controllers
3DS I2C New3DS Near-Field Communication (NFC)
3DS NFC Adapter
3DS I2C New3DS C-Stick and ZL/ZR-Buttons
3DS I2C New3DS 16bit IO Expander (aka QTM)
3DS I2C Other/Unused/Debug Devices
3DS Video
3DS Video LCD Registers
3DS GPU Memory and I/O Map
3DS GPU External Register List Summary
3DS GPU Internal Register List Summary
3DS GPU External Registers - Memory Control/Status Registers
3DS GPU External Registers - Top/Bottom Screen and Framebuffer Setup
3DS GPU External Registers - Memfill and Memcopy
3DS GPU Internal Register Overview
3DS GPU Internal Registers - Command Lists
3DS GPU Internal Registers - Finalize Interrupt registers
3DS GPU Internal Registers - Geometry Pipeline registers
3DS GPU Internal Registers - Shader registers
3DS GPU Internal Registers - Rasterizer registers
3DS GPU Internal Registers - Framebuffer registers
3DS GPU Internal Registers - Texturing registers (Generic Textures)
3DS GPU Internal Registers - Texturing registers (Procedural Texture)
3DS GPU Internal Registers - Texturing registers (Environment)
3DS GPU Internal Registers - Fragment Lighting registers
3DS GPU Internal Registers - Unknown/Unused/Undocumented Registers
3DS GPU Shader Instruction Set - Opcode Summary
3DS GPU Shader Instruction Set - Blurp
3DS GPU Geometry Pipeline
3DS GPU Fragment Lighting
3DS GPU Pitfalls
3DS GPU Primitive Engine and Shaders
3DS GPU Triangle Drawing Sample Code
3DS Video CAM Registers (Camera Input)
3DS Video Y2R Registers (YUV-to-RGBA Converter)
3DS Video L2B Registers (RGB-to-RGBA Converter) (New3DS)
3DS Video MVD Registers (Movie Decoder or so?) (New3DS)
3DS Video LGY Registers (Legacy GBA/NDS Video to Framebuffer)
3DS Video Texture Swizzling
3DS Sound and Microphone
3DS Cartridge Registers
3DS Interrupts and Timers
3DS ARM9 Interrupts
3DS ARM9 Timers
3DS ARM11 Interrupts
ARM11 MPCore Private Memory Region Register Summary
ARM11 MPCore - Snoop Control Unit (SCU)
ARM11 MPCore - Timer and Watchdog
ARM11 MPCore - Interrupt Configuration
ARM11 MPCore - Interrupt Handling
ARM11 MPCore Distributed Interrupt Controller (Blurb)
ARM Vector Floating-point Unit (VFP)
ARM VFP Floating Point Registers
ARM VFP Floating Point Control/Status Registers
ARM VFP Floating Point Opcode Encoding
ARM VFP Floating Point Maths Opcodes
ARM VFP Floating Point Load/Store Opcodes
3DS eMMC Partitions
3DS NCSD Format
3DS FIRM Format
3DS FIRM Encryption
3DS FIRM Versions
3DS FIRM Launch Parameters
3DS NCCH Format
3DS NCCH Extended Header
3DS NCCH ExeFS
3DS NCCH RomFS
3DS NCCH Encryption
3DS NCCH Logo
3DS Files - Title Content Metadata (CMD)
3DS Files - Title Metadata (TMD)
3DS Files - Title Ticket (ticket.db)
3DS Files - Title Certificates (certs.db)
3DS Files - Title Database Files (title.db, import.db, etc.)
3DS Files - Title Installation Archive (CIA)
3DS Files - Title Homebrew Executables (3DSX)
3DS Files - Client Cert/Key (ClCertA)
3DS Files - CTCert
3DS Files - Dictionary (NJDC)
3DS Files - Guide (GBIN)
3DS Files - Version (CVer and NVer)
3DS Files - CRR0 and CRO0 Files
3DS Files - Archive DARC
3DS Files - Archive SARC
3DS Files - Archive arcless
3DS Files - Archive ZAR
3DS Files - CCAL Format (Hardware calibration, HWCAL)
3DS Files - Config Savegame
3DS Files - Title IDs
3DS Files - Title NS
3DS Files - Savedata Extdata
3DS Files - Savedata SAVE/BDRI/VSXE Formats
3DS Files - Savedata DISA and DIFF
3DS Files - Savedata DISA and DIFF - Data Pairs
3DS Files - Savedata DISA and DIFF - Checksums
3DS Files - Savedata Gamecard FLASH Encryption and Wear Leveling
3DS Files - Messages (MsgStdBn)
3DS Files - Video Icons (SMDH)
3DS Files - Video Banner (CBMD)
3DS Files - Video Banner (Extended Banner)
3DS Files - Video Layout (CLYT/FLYT)
3DS Files - Video Layout Animation (CLAN/FLAN)
3DS Files - Video Layout Images (CLIM/FLIM)
3DS Files - Video Archive (CGFX)
3DS Files - Video Archive (CGFX Header, Blocks, DICTs)
3DS Files - Video Archive (CGFX_00h - CMDL Models)
3DS Files - Video Archive (CGFX_01h - TXOB Textures)
3DS Files - Video Archive (CGFX_02h - LUTS Look-up Tables)
3DS Files - Video Archive (CGFX_04h - SHDR Shaders)
3DS Files - Video Archive (CGFX_05h - CCAM Cameras)
3DS Files - Video Archive (CGFX_06h - CFLT/CHLT/CALT Lights)
3DS Files - Video Archive (CGFX_08h - CENV Environments)
3DS Files - Video Archive (CGFX_09h,0Ah,0Dh - CANM Animations)
3DS Files - Video Archive (CGFX_0Eh,0Fh - PEMT Emitters/Particles)
3DS Files - Video Shaders (DVLB and DVOB Format)
3DS Files - Video Fonts (CFNT and FFNT Format)
3DS Files - Video Texture Package (CTPK)
3DS Files - Video Bitmap (BMP)
3DS Files - BASE64 Encoding
3DS Files - Video 3D Photos (MPO)
3DS Files - Sound Archive (CSAR Format)
3DS Files - Sound SEQ (CSEQ Format)
3DS Files - Sound WSD (CWSD Format)
3DS Files - Sound Bank (CBNK Format)
3DS Files - Sound Wave Archive (CWAR Format)
3DS Files - Sound Wave Data (CWAV Format)
3DS Files - Sound Wave Streams (CSTM Format)
3DS Files - Sound Group (CGRP Format)
3DS Files - Sound IDs (CSID Format)
3DS Files - Sound DSP Binary (DSP1 aka .cdc)
3DS Files - Module NWM (Wifi Driver)
Non-DS Files - RARC Archives
Non-DS Files - U8 Archives
3DS Console IDs
3DS eMMC and MCU Images
3DS Component Lists
3DS Chipset Pinouts
ARM CPU Reference
ARM CPU Overview
ARM CPU Register Set
ARM CPU Flags & Condition Field (cond)
ARM CPU 26bit Memory Interface
ARM CPU Exceptions
ARM CPU Memory Alignments
ARM Instruction Summary
ARM Opcodes: Branch and Branch with Link (B, BL, BX, BLX, SWI, BKPT)
ARM Opcodes: Data Processing (ALU)
ARM Opcodes: Multiply and Multiply-Accumulate (MUL, MLA)
ARM Opcodes: Special ARM9 Instructions (CLZ, QADD/QSUB)
ARM Opcodes: Special ARM11 Instructions (Misc)
ARM Opcodes: Special ARM11 Instructions (SIMD)
ARM Opcodes: PSR Transfer (MRS, MSR)
ARM Opcodes: Memory: Single Data Transfer (LDR, STR, PLD)
ARM Opcodes: Memory: Halfword, Doubleword, and Signed Data Transfer
ARM Opcodes: Memory: Block Data Transfer (LDM, STM)
ARM Opcodes: Memory: Single Data Swap (SWP)
ARM Opcodes: Coprocessor Instructions (MRC/MCR, LDC/STC, CDP, MCRR/MRRC)
THUMB Instruction Summary
THUMB Opcodes: Register Operations (ALU, BX)
THUMB Opcodes: Memory Load/Store (LDR/STR)
THUMB Opcodes: Memory Addressing (ADD PC/SP)
THUMB Opcodes: Memory Multiple Load/Store (PUSH/POP and LDM/STM)
THUMB Opcodes: Jumps and Calls
THUMB Opcodes: New THUMB Opcodes in ARM11
ARM Pseudo Instructions and Directives
ARM CP14 ICEbreaker Debug Communications Channel
ARM CP15 System Control Coprocessor
ARM CP15 Overview
ARM CP15 ID Codes
ARM CP15 Control Register
ARM CP15 Memory Managment Unit (MMU)
ARM CP15 Protection Unit (PU)
ARM CP15 Cache Control
ARM CP15 Tightly Coupled Memory (TCM)
ARM CP15 Misc
ARM CPU Instruction Cycle Times
ARM CPU Versions
ARM CPU Data Sheet
BIOS Functions
BIOS Function Summary
BIOS Differences between GBA and NDS functions
BIOS Arithmetic Functions
BIOS Rotation/Scaling Functions
BIOS Decompression Functions
BIOS Memory Copy
BIOS Halt Functions
BIOS Reset Functions
BIOS Misc Functions
BIOS Multi Boot (Single Game Pak)
BIOS Sound Functions
BIOS SHA1 Functions (DSi only)
BIOS RSA Functions (DSi only)
BIOS RSA Basics
BIOS RSA Pseudo Code
BIOS 3DS Exception Vectors
BIOS RAM Usage
BIOS Dumping
External Connectors
AUX GBA Game Pak Bus
AUX DS Game Card Slot
AUX Link Port
AUX Sound/Headphone Socket and Battery/Power Supply
AUX DSi SD/MMC Pin-Outs
AUX Opening the GBA
AUX Mainboard
AUX DSi Component Lists
AUX DSi Internal Connectors
AUX DSi Chipset Pinouts
Pinouts - CPU - Signal Summary
Pinouts - CPU - Pinouts
Pinouts - Audio Amplifiers
Pinouts - LCD Cables
Pinouts - Power Switches, DC/DC Converters, Reset Generators
Pinouts - Wifi
Pinouts - Various
AUX Xboo PC-to-GBA Multiboot Cable
AUX Xboo Flashcard Upload
AUX Xboo Burst Boot Backdoor
DSi Emulation
Notes on New NDS Emulation
Pocketstation Emulation
Pocketstation XBOO Cable
Installation
Debugging
Hotkeys in Debug Mode
Hotkeys in Emulation Mode
Breakpoints
Profiling & Performance Monitoring
Profiler Window
Profiler Compatibility
Clock Cycle Comments
Cycle Counters
Debug Messages
Symbolic Debug Info
XED Editor
XED About
XED Hotkeys
XED Assembler/Debugger Interface
XED Commandline based standalone version
The A22i Assembler
Using LDR Rd,=Imm in Online Assembler
About this Document
[extracted from no$gba v3.03 documentation]