MMIO register table/MMIO

Name	Address	Bits	Type	Notes
APUIO0 APUIO1 APUIO2 APUIO3	$2140 $2141 $2142 $2143	DDDD DDDD	RW8	Data to/from APU.
WMDATA	$2180	DDDD DDDD	RW8	Data to/from S-WRAM. Increments WMADD.
WMADDL WMADDM WMADDH	$2181 $2182 $2183	LLLL LLLL MMMM MMMM .... ...H	W24	S-WRAM address for WMDATA access.
JOYOUT	$4016	.... ...D	W8	Output to joypads. Latches standard controllers.
JOYSER0	$4016	.... ..DD	R8	Input from joypad 1.
JOYSER1	$4017	...1 11DD	R8	Always 1 (1), Input from joypad 2 (D).
NMITIMEN	$4200	N.VH ...J	W8	Vblank NMI enable (N), Timer IRQ mode (VH), Joypad auto-read enable (J).
WRIO	$4201	21DD DDDD	W8	Joypad port 2 I/O (2), Joypad port 1 I/O (1), Unused I/O (D).
WRMPYA	$4202	DDDD DDDD	W8	Unsigned multiplication factor A.
WRMPYB	$4203	DDDD DDDD	W8	Unsigned multiplication factor B. Starts 8-cycle multiplication.
WRDIVL WRDIVH	$4204 $4205	LLLL LLLL HHHH HHHH	W16	Unsigned dividend.
WRDIVB	$4206	DDDD DDDD	W8	Unsigned divisor. Starts 16-cycle division.
HTIMEL HTIMEH	$4207 $4208	.... ...H LLLL LLLL	W16	H counter target for timer IRQ.
VTIMEL VTIMEH	$4209 $420A	.... ...H LLLL LLLL	W16	V counter target for timer IRQ.
MEMSEL	$420D	F... ....	W8	FastROM enable (F).
RDNMI	$4210	N... VVVV	R8	Vblank NMI flag (N), CPU version (V).
TIMEUP	$4211	T... ....	R8	Timer IRQ flag (T).
HVBJOY	$4212	VH.. ...J	R8	Vblank flag (V), Hblank flag (H), Joypad auto-read in-progress flag (J).
RDIO	$4213	21DD DDDD	R8	Joypad port 2 I/O (2), Joypad port 1 I/O (1), Unused I/O (D).
RDDIVL RDDIVH	$4214 $4215	LLLL LLLL HHHH HHHH	R16	Unsigned quotient.
RDMPYL RDMPYH	$4216 $4217	LLLL LLLL HHHH HHHH	R16	Unsigned product or unsigned remainder.
JOY1L JOY1H JOY2L JOY2H JOY3L JOY3H JOY4L JOY4H	$4218 $4219 $421A $421B $421C $421D $421E $421F	LLLL LLLL HHHH HHHH	R16	16-bit joypad auto-read result (first read high to last read low).