From SNESdev Wiki

This page is incomplete.

Contents 1 Address Bus B Registers 2 Old Style Joypad Registers 3 Internal CPU Registers 4 DMA/HDMA registers 5 HDMA Registers 6 Notes On Creating Register Pages

Address Bus B Registers

TODO: note on fast access time

Register	Address	Name	Style	Access	Timing
Screen Display Register	$2100	INIDISP	single	write	any time
Object Size and Character Size Register	$2101	OBSEL	single	write	f-blank, v-blank
OAM Address Registers	$2102 $2103	OAMADDL OAMADDH	single	write	f-blank, v-blank
OAM Data Write Register	$2104	OAMDATA	single	write	f-blank, v-blank
BG Mode and Character Size Register	$2105	BGMODE	single	write	f-blank, v-blank, h-blank
Mosaic Register	$2106	MOSAIC	single	write	f-blank, v-blank, h-blank
BG Tilemap Address Registers	$2107 $2108 $2109 $210A	BG1SC BG2SC BG3SC BG4SC	single	write	f-blank, v-blank
BG Character Address Registers	$210B $210C	BG12NBA BG34NBA	single	write	f-blank, v-blank
BG Scroll Registers	$210D $210E $210F $2110 $2111 $2112 $2113 $2114	BG1HOFS BG1VOFS BG2HOFS BG2VOFS BG3HOFS BG3VOFS BG4HOFS BG4VOFS	dual	write	f-blank, v-blank, h-blank
Video Port Control Register	$2115	VMAIN	single	write	f-blank, v-blank
VRAM Address Registers	$2116 $2117	VMADDL VMADDH	single	write	f-blank, v-blank
VRAM Data Write Registers	$2118 $2119	VMDATAL VMDATAH	single	write	f-blank, v-blank
Mode 7 Settings Register	$211A	M7SEL	single	write	f-blank, v-blank
Mode 7 Matrix Registers	$211B $211C $211D $211E $211F $2120	M7A M7B M7C M7D M7X M7Y	dual	write	f-blank, v-blank, h-blank
CGRAM Address Register	$2121	CGADD	single	write	f-blank, v-blank, h-blank
CGRAM Data Write Register	$2122	CGDATA	dual	write	f-blank, v-blank, h-blank
Window Mask Settings Registers	$2123 $2124 $2125	W12SEL W34SEL WOBJSEL	single	write	f-blank, v-blank, h-blank
Window Position Registers	$2126 $2127 $2128 $2129	WH0 WH1 WH2 WH3	single	write	f-blank, v-blank, h-blank
Window Mask Logic registers	$212A $212B	WBGLOG WOBJLOG	single	write	f-blank, v-blank, h-blank
Screen Destination Registers	$212C $212D	TM TS	single	write	f-blank, v-blank, h-blank
Window Mask Destination Registers	$212E $212F	TMW TSW	single	write	f-blank, v-blank, h-blank
Color Math Registers	$2130 $2131 $2132	CGWSEL CGADSUB COLDATA	single	write	f-blank, v-blank, h-blank
Screen Mode Select Register	$2133	SETINI	single	write	f-blank, v-blank, h-blank
Multiplication Result Registers	$2134 $2135 $2136	MPYL MPYM MPYH	single	read	f-blank, v-blank, h-blank
Software Latch Register	$2137	SLHV	single		any time
OAM Data Read Register	$2138	OAMDATAREAD	dual	read	f-blank, v-blank
VRAM Data Read Register	$2139 $213A	VMDATALREAD VMDATAHREAD	single	read	f-blank, v-blank
CGRAM Data Read Register	$213B	CGDATAREAD	dual	read	f-blank, v-blank
Scanline Location Registers	$213C $213D	OPHCT OPVCT	dual	read	any time
PPU Status Register	$213E $213F	STAT77 STAT78	single	read	any time
APU IO Registers	$2140 $2141 $2143 $2144	APUIO0 APUIO1 APUIO2 APUIO3	single	read/write	any time
WRAM Data Register	$2180	WMDATA	single	read/write	any time
WRAM Address Registers	$2181 $2182 $2183	WMADDL WMADDM WMADDH	single	write	any time

Old Style Joypad Registers

TODO: note on extra slow access time

Old Style Joypad Registers

$4016 $4017

JOYSER0 JOYSER1

single (write) many (read)

read/write read

any time that is not auto-joypad

Internal CPU Registers

TODO: note on fast access time

Register	Address	Name	Style	Access	Timing
Interrupt Enable Register	$4200	NMITIMEN	single	write	any time
IO Port Write Register	$4201	WRIO	single	write	any time
Multiplicand Registers	$4202 $4203	WRMPYA WRMPYB	single	write	any time
Divisor & Dividend Registers	$4204 $4205 $4206	WRDIVL WRDIVH WRDIVB	single	write	any time
IRQ Timer Registers	$4207 $4208 $4209 $420A	HTIMEL HTIMEH VTIMEL VTIMEH	single	write	any time
DMA Enable Register	$420B	MDMAEN	single	write	any time
HDMA Enable Register	$420C	HDMAEN	single	write	any time
ROM Speed Register	$420D	MEMSEL	single	write	any time
Interrupt Flag Registers	$4210 $4211	RDNMI TIMEUP	single	read	any time
PPU Status Register	$2112	HVBJOY	single	read	any time
IO Port Read Register	$4213	RDIO	single	read	any time
Multiplication Or Divide Result Registers	$4214 $4215 $4216 $4217	RDDIVL RDDIVH RDMPYL RDMPYH	single	read	any time
Controller Port Data Registers	$4218 $4219 $421A $421B $421C $421D $421E $421F	JOY1L JOY1H JOY2L JOY2H JOY3L JOY3H JOY4L JOY4H	single	read	any time that is not auto-joypad

DMA/HDMA registers

Template:SeeAlso

These registers can be read or written at any time. TODO: write something about fast access time. TODO: write something about x here.

DMA Registers

Register	Address	Name
DMA Control Register	$43x0	DMAPx
DMA Destination Register	$43x1	BBADx
DMA Source Address Registers	$43x2 $43x3 $43x4	A1TxL A1TxH A1Bx
DMA Size Registers	$43x5 $43x6	DASxL DASxH

HDMA Registers

Template:SeeAlso

These registers can be read or written at any time. TODO: write something about fast access time. TODO: write something about x here.

Register	Address	Name
HDMA Control Register	$43x0	DMAPx
HDMA Destination Register	$43x1	BBADx
HDMA Table Address Registers	$43x2 $43x3 $43x4	A1TxL A1TxH A1Bx
HDMA Indirect Address Registers	$43x5 $43x6 $43x7	DASxL DASxH DASBx
HDMA Mid Frame Table Address Registers	$43x8 $43x9	A2AxL A2AxH
HDMA Line Counter Register	$43xA	NTLRX

Notes On Creating Register Pages

• All register pages should be based on the Register Example page.
• The name of the register page should be unofficial name of the register.
• Register pages can be combined. For example the OAM Address Registers, OAM Data Write Register and the OAM Data Read Register can redirect to the combined page OAM Data Transfer Registers. However, if you combine register pages, then you must include separate Register Boxes for each register section shown.
• Redirections should be created, that redirect the official name and the address of the register to the register page. For example, the pages $2102, $2103, OAMADDL and OAMADDH should link to the page OAM Address Register