MMC4 pinout

Nintendo MMC4: 44-pin TQFP

                      / \
                     / O \
         Unknown ?? /01 44\ <- CPU R/W
        /ROMSEL -> /02   43\ <- CPU D0
       PPU /RD -> /03     42\ <- CPU D1
       PPU A3 -> /04       41\ <- CPU D2
     Unknown ?? /05         40\ <- CPU D3
       GND  -- /06         \ 39\ <- CPU D4
    PPU A4 -> /07           \ 38\ -> PRG /CE
   PPU A5 -> /08         \  _\ 37\ -> PRG A17
  PPU A6 -> /09         \ \|    36\ -> PRG A16
 PPU A7 -> /10           \ \     35\ -> PRG A15

Unknown ?? /11 \ _\ 34\ -> PRG A14

PPU A8 -> \12       /\ \|         33/ - tied to pin 32
 PPU A9 -> \13        \ \        32/ <- CPU A12
 PPU A10 -> \14        \        31/ <- CPU A13
  PPU A11 -> \15  \/\  /       30/ <- CPU A14
   PPU A12 -> \16  \ \        29/ <- M2
    PPU A13 -> \17  \        28/ --  GND
        GND  -- \18         27/ --  VCC
      CHR A12 <- \19       26/ -> VRAM A10              Legend:
       CHR A13 <- \20     25/ -> PRG RAM +CE             Input: -> [MMC4] <-
        CHR A14 <- \21   24/ -> CHR A16                 Output: <- [MMC4] ->
         CHR A15 <- \22 23/ -> PRG RAM /CE               Power: -- [MMC4] --
                     \   /	                             Unknown ?? [MMC4] ??
                      \ /

• Source: INL on the forum