User:Lidnariq/Microchip-style PPU documentation

Just so I can find these again easily:

Microchip-style documentation format

REGISTER: PPUCTRL: PPU properties

W-0/0	W-0/0	W-0/0	W-0/0	W-0/0	W-0/0	W-0/0	W-0/0
NMIEN	EXTOUTEN	SPR8x16	BKGD	SPR	INC32	Y8	X8
bit 7							bit 0

Legend
R = Readable bit	W = Writable bit	U = Unimplemented bit, read as open bus
u = bit is unchanged	x = bit is unknown	-n/n = value on Power-on/all other resets
1 = bit is set	0 = bit is cleared	q = value depends on conditions

bit 7	NMIEN: NMI enable 1 = NMI is triggered at start of vblank, after 1 (or 51) post-render scanlines 0 = NMI is not triggered
bit 6	EXTOUTEN: External output Enable 1 = output bottom 4 bits of color on EXT pins 0 = accept bottom 4 bits of backdrop on EXT pins (background colors 1-3 are opaque; color 0 is transparent and from the external port)
bit 5	SPR8x16: Sprites size 1 = All sprites are 8x16 0 = All sprites are 8x8
bit 4	BKGD: Background tile location 1 = Background tiles are fetched from PPU $1xxx 0 = Background tiles are fetched from PPU $0xxx
bit 3	SPR: Sprite tile location 1 = Sprite tiles are fetched from PPU $1xxx 0 = Sprite tiles are fetched from PPU $0xxx
bit 2	INC32: PPU address autoincrement step size 1 = PPU address increments by 32 after reads or writes to PPUDATA 0 = PPU address increments by 1 after reads or writes to PPUDATA
bit 1	Y8: 240s bit of Y scroll position 1 = Rendering will start in nametable at $2800 or $2C00 0 = Rendering will start in nametable at $2000 or $2400
bit 0	X8: 256s bit of X scroll position 1 = Rendering will start in nametable at $2400 or $2C00 0 = Rendering will start in nametable at $2000 or $2800