Module gba::mmio

Contains all the MMIO address definitions for the GBA’s components.

This module contains only the MMIO addresses. The data type definitions for each MMIO control value are stored in the appropriate other modules such as video, interrupts, etc.

In general, the docs for each address are quite short. If you want to understand how a subsystem of the GBA works, you should read the docs for that system’s module, and the data type used by the address.

The GBATEK names (and thus mGBA names) are used for the MMIO addresses by default. However, in some cases (eg: sound) the GBATEK naming is excessively cryptic, and so new names have been created. Whenever a new name is used, the GBATEK name is still listed as a doc alias for that address. If necessary you can just search the GBATEK name in the rustdoc search bar and the search results will show you the new name.

Safety

The MMIO declarations and wrapper types in this module must not be used outside of a GBA. The read and write safety of each address are declared assuming that code is running on a GBA. On any other platform, the declarations are simply incorrect.

Structs

• Safe
  Lets you put “Safe” into a generic type parameter.
• Unsafe
  Lets you put “Unsafe” into a generic type parameter.
• VolAddress
  A volatile address.
• VolBlock
  A volatile memory block.
• VolGrid2d
  A 2D version of VolBlock, with a const generic WIDTH and HEIGHT.
• VolGrid2dStrided
  Models having many “frames” of VolGrid2d within a chunk of memory.
• VolSeries
  A volatile memory “series”.
• u8x2
  Two u8 values packed as a u16.

Constants

• AFFINE0_SCREENBLOCKS
  Affine screenblocks (size 0).
• AFFINE1_SCREENBLOCKS
  Affine screenblocks (size 1).
• AFFINE2_SCREENBLOCKS
  Affine screenblocks (size 2).
• AFFINE3_SCREENBLOCKS
  Affine screenblocks (size 3).
• AFFINE_PARAM_A
  Affine parameters A.
• AFFINE_PARAM_B
  Affine parameters B.
• AFFINE_PARAM_C
  Affine parameters C.
• AFFINE_PARAM_D
  Affine parameters D.
• BACKDROP_COLOR
  Color that’s shown when no BG or OBJ draws to a pixel
• BG0CNT
  Background 0 Control
• BG0HOFS
  Background 0 Horizontal Offset (9-bit, text mode)
• BG0VOFS
  Background 0 Vertical Offset (9-bit, text mode)
• BG1CNT
  Background 1 Control
• BG1HOFS
  Background 1 Horizontal Offset (9-bit, text mode)
• BG1VOFS
  Background 1 Vertical Offset (9-bit, text mode)
• BG2CNT
  Background 2 Control
• BG2HOFS
  Background 2 Horizontal Offset (9-bit, text mode)
• BG2PA
  Background 2 Param A (affine mode)
• BG2PB
  Background 2 Param B (affine mode)
• BG2PC
  Background 2 Param C (affine mode)
• BG2PD
  Background 2 Param D (affine mode)
• BG2VOFS
  Background 2 Vertical Offset (9-bit, text mode)
• BG2X
  Background 2 X Reference Point (affine/bitmap modes)
• BG2Y
  Background 2 Y Reference Point (affine/bitmap modes)
• BG3CNT
  Background 3 Control
• BG3HOFS
  Background 3 Horizontal Offset (9-bit, text mode)
• BG3PA
  Background 3 Param A (affine mode)
• BG3PB
  Background 3 Param B (affine mode)
• BG3PC
  Background 3 Param C (affine mode)
• BG3PD
  Background 3 Param D (affine mode)
• BG3VOFS
  Background 3 Vertical Offset (9-bit, text mode)
• BG3X
  Background 3 X Reference Point (affine/bitmap modes)
• BG3Y
  Background 3 Y Reference Point (affine/bitmap modes)
• BG_PALETTE
  Background tile palette entries.
• BG_TILE_REGION_SIZE
  The size of the background tile region of VRAM.
• BLDALPHA
  Sets EVA(low) and EVB(high) alpha blend coefficients, allows 0..=16, in 1/16th units
• BLDCNT
  Sets color blend effects
• BLDY
  Sets EVY brightness blend coefficient, allows 0..=16, in 1/16th units
• CHARBLOCK0_4BPP
  Charblock 0, 4bpp view (512 tiles).
• CHARBLOCK0_8BPP
  Charblock 0, 8bpp view (256 tiles).
• CHARBLOCK1_4BPP
  Charblock 1, 4bpp view (512 tiles).
• CHARBLOCK1_8BPP
  Charblock 1, 8bpp view (256 tiles).
• CHARBLOCK2_4BPP
  Charblock 2, 4bpp view (512 tiles).
• CHARBLOCK2_8BPP
  Charblock 2, 8bpp view (256 tiles).
• CHARBLOCK3_4BPP
  Charblock 3, 4bpp view (512 tiles).
• CHARBLOCK3_8BPP
  Charblock 3, 8bpp view (256 tiles).
• DISPCNT
  Display Control
• DISPSTAT
  Display Status
• DMA0_CONTROL
  DMA0 Control Bits
• DMA0_COUNT
  DMA0 Transfer Count (14-bit, 0=max)
• DMA0_DEST
  DMA0 Destination Address (internal memory only)
• DMA0_SRC
  DMA0 Source Address (internal memory only)
• DMA1_CONTROL
  DMA1 Control Bits
• DMA1_COUNT
  DMA1 Transfer Count (14-bit, 0=max)
• DMA1_DEST
  DMA1 Destination Address (internal memory only)
• DMA1_SRC
  DMA1 Source Address (non-SRAM memory)
• DMA2_CONTROL
  DMA2 Control Bits
• DMA2_COUNT
  DMA2 Transfer Count (14-bit, 0=max)
• DMA2_DEST
  DMA2 Destination Address (internal memory only)
• DMA2_SRC
  DMA2 Source Address (non-SRAM memory)
• DMA3_CONTROL
  DMA3 Control Bits
• DMA3_COUNT
  DMA3 Transfer Count (16-bit, 0=max)
• DMA3_DEST
  DMA3 Destination Address (non-SRAM memory)
• DMA3_SRC
  DMA3 Source Address (non-SRAM memory)
• FIFO_A
  Pushes 4 i8 samples into the Sound A buffer.
• FIFO_B
  Pushes 4 i8 samples into the Sound B buffer.
• IE
  Interrupts Enabled: sets which interrupts will be accepted when a subsystem fires an interrupt
• IF
  Interrupts Flagged: reads which interrupts are pending, writing bit(s) will clear a pending interrupt.
• IME
  Interrupt Master Enable: Allows turning on/off all interrupts with a single access.
• IO_PORT_CONTROL
  I/O port control
• IO_PORT_DATA
  I/O port data
• IO_PORT_DIRECTION
  I/O port direction
• JOYCNT
• JOYSTAT
• JOY_RECV
• JOY_TRANS
• KEYCNT
  Key control to configure the key interrupt.
• KEYINPUT
  Key state data.
• LEFT_RIGHT_VOLUME
  Left/Right sound control (but GBAs only have one speaker each).
• MGBA_LOG_BUFFER
  The buffer to put logging messages into.
• MGBA_LOG_ENABLE
  Allows you to attempt to activate mGBA logging.
• MGBA_LOG_SEND
  Write to this each time you want to reset a message (it also resets the buffer).
• MOSAIC
  Sets the intensity of all mosaic effects
• NOISE_FREQ
  Noise Frequency/Control
• NOISE_LEN_ENV
  Noise Length/Envelope
• OBJ_ATTR0
  Object attributes 0.
• OBJ_ATTR1
  Object attributes 1.
• OBJ_ATTR2
  Object attributes 2.
• OBJ_ATTR_ALL
  Object attributes (all in one).
• OBJ_PALETTE
  Object tile palette entries.
• OBJ_TILES
  Object tiles. In video modes 3, 4, and 5 only indices 512..=1023 are available.
• RCNT
• SCREENBLOCK_INDEX_OFFSET
  The VRAM byte offset per screenblock index.
• SIOCNT
• SIODATA8
• SIODATA32
• SIOMLT_SEND
• SIOMULTI0
• SIOMULTI1
• SIOMULTI2
• SIOMULTI3
• SOUNDBIAS
  Provides a bias to set the ‘middle point’ of sound output.
• SOUND_ENABLED
  Sound active flags (r), as well as the sound primary enable (rw).
• SOUND_MIX
  Mixes sound sources out to the left and right
• TEXT_SCREENBLOCKS
  Text mode screenblocks.
• TIMER0_CONTROL
  Timer 0 control
• TIMER0_COUNT
  Timer 0 Count read
• TIMER0_RELOAD
  Timer 0 Reload write
• TIMER1_CONTROL
  Timer 1 control
• TIMER1_COUNT
  Timer 1 Count read
• TIMER1_RELOAD
  Timer 1 Reload write
• TIMER2_CONTROL
  Timer 2 control
• TIMER2_COUNT
  Timer 2 Count read
• TIMER2_RELOAD
  Timer 2 Reload write
• TIMER3_CONTROL
  Timer 3 control
• TIMER3_COUNT
  Timer 3 Count read
• TIMER3_RELOAD
  Timer 3 Reload write
• TONE1_FREQUENCY
  Tone 1 Frequency/Control
• TONE1_PATTERN
  Tone 1 Duty/Len/Envelope
• TONE1_SWEEP
  Tone 1 Sweep
• TONE2_FREQUENCY
  Tone 2 Frequency/Control
• TONE2_PATTERN
  Tone 2 Duty/Len/Envelope
• VCOUNT
  Vertical Counter
• VIDEO3_VRAM
  Video mode 3 bitmap
• VIDEO4_VRAM
  Video mode 4 palette maps (frames 0 and 1). Each entry is two palette indexes.
• VIDEO5_VRAM
  Video mode 5 bitmaps (frames 0 and 1).
• WAITCNT
  Wait state control for interfacing with the ROM.
• WAVE_BANK
  Wave banking controls
• WAVE_FREQ
  Wave Frequency/Control
• WAVE_LEN_VOLUME
  Wave Length/Volume
• WAVE_RAM
  Wave memory, u4, plays MSB/LSB per byte.
• WIN0H
  Window 0 Horizontal: high=left, low=(right+1)
• WIN0V
  Window 0 Vertical: high=top, low=(bottom+1)
• WIN1H
  Window 1 Horizontal: high=left, low=(right+1)
• WIN1V
  Window 1 Vertical: high=top, low=(bottom+1)
• WININ
  Controls the inside Windows 0 and 1
• WINOUT
  Controls inside the object window and outside of windows

Functions

• bg_palbank
• obj_palbank