PPU pinout

Pinout
^                                        / \                                        /   \                                       /     \                              TST1 -> / 1 100 \ <- SYSTEM CLK TST0 -> / 2   99 \ <- TST2 /PRD -> / 3 (*) 98 \ <- /RESET /PWR -> / 4       97 \ <- /PIXEL CLK IN                           PA7 -> / 5          96 \ -- GND PA6 -> / 6           95 \ ?? FIELD PA5 -> / 7             94 \ -> /OVER PA4 -> / 8               93 \ -> /PIXEL CLK OUT PA3 -> / 9                 92 \ ?? /HCLD PA2 -> / 10                  91 \ ?? /VCLD PA1 -> / 11                    90 \ -> COLOR0 PA0 -> / 12                      89 \ -> COLOR1 +5V -- / 13                        88 \ -> COLOR2 CPU D7 <> / 14                          87 \ -> PRIO0 CPU D6 <> / 15                            86 \ -> PRIO1 CPU D5 <> / 16                              85 \ -> CHR0 CPU D4 <> / 17                                84 \ -> CHR1 CPU D3 <> / 18                                  83 \ -> CHR2 CPU D2 <> / 19                                    82 \ -> CHR3 CPU D1 <> / 20                                      81 \ -- +5V CPU D0 <> / 21                                           \ GND -- / 22                                            / HVCMODE -> / 23                                         80 / -> /VRD PALMODE -> / 24                                         79 / -> /VBWR /MASTER -> / 25                                         78 / -> /VAWR /EXTSYNC -> / 26             Nintendo 5C77               77 / -- GND GND -- / 27     Package QFP-100, 0.65mm pitch       76 / -> VAA0 VDB0 <> / 28                                         75 / -> VAA1 VDB1 <> / 29                 S-PPU1                  74 / -> VAA2 VDB2 <> / 30                                         73 / -> VAA3 /                                            72 / -> VAA4 \                                           71 / -> VAA5 VDB3 <> \ 31                                      70 / -> VAA6 VDB4 <> \ 32                                    69 / -> VAA7 VDB5 <> \ 33                                  68 / -> VAA8 VDB6 <> \ 34                                67 / -> VAA9 VDB7 <> \ 35                              66 / -> VAA10 +5V -- \ 36                            65 / -> VAA11 VDA0 <> \ 37                          64 / -> VAA12                    Orientation: VDA1 <> \ 38                        63 / -> VAA13 VDA2 <> \ 39                      62 / -- +5V                          80         51 VDA3 <> \ 40                    61 / -> VAB0                           |         | VDA4 <> \ 41                  60 / -> VAB1                           .---. VDA5 <> \ 42                59 / -> VAB2                         81-| Nintendo O|-50 VDA6 <> \ 43              58 / -> VAB3                             |  S-PPU1   | VDA7 <> \ 44            57 / -> VAB4                          100-|@  5C77    |-31 GND -- \ 45          56 / -> VAB5                               '---' VA15 <- \ 46        55 / -> VAB6                                 |         | VA14 <- \ 47  O   54 / -> VAB7                                 01         30 VAB13 <- \ 48    53 / -> VAB8 VAB12 <- \ 49  52 / -> VAB9                     Legend: VAB11 <- \ 50 51 / -> VAB10 \    /                               --[5C77]-- Power, n/a \  /                                ->[5C77]<- 5C77 input \ /                                <-[5C77]-> 5C77 output V                                 <>[5C77]<> Bidirectional ??[5C77]?? Unknown

Pinout
_____                                             /     \                                   /BURST <- / 1 100 \ -> /CSYNC /PED ?? / 2   99 \ -- GND COLORBURST CLK <- / 3     98 \ <- HVCMODE /TRANSPARENT <- / 4       97 \ -> B                                  +5V -- / 5          96 \ -> G                                /PWR -> / 6            95 \ -> R                               /PRD -> / 7              94 \ -- +5VA CPU D7 <> / 8               93 \ <- DIGITAL VIDEO ENABLE CPU D6 <> / 9                 92 \ <- TST14 CPU D5 <> / 10                  91 \ <- TST13 CPU D4 <> / 11                    90 \ <- TST12 CPU D3 <> / 12                      89 \ ?? TST11 CPU D2 <> / 13                        88 \ ?? TST10 CPU D1 <> / 14                          87 \ ?? TST9 CPU D0 <> / 15                            86 \ ?? TST8 GND -- / 16                              85 \ ?? TST7 PA7 -> / 17                                84 \ ?? TST6 PA6 -> / 18                                  83 \ -- +5V PA5 -> / 19                                    82 \ ?? TST5 PA4 -> / 20                                      81 \ ?? TST4 PA3 -> / 21                                           \ PA2 -> / 22                                    O       / PA1 -> / 23                                         80 / ?? TST3 PA0 -> / 24                                         79 / ?? TST2 HBLANK <- / 25                                         78 / ?? TST1 VBLANK <- / 26             Nintendo 5C78               77 / ?? TST0 /PIXEL CLK OUT <- / 27     Package QFP-100, 0.65mm pitch       76 / <- EXT7 /RESOUT1 <- / 28                                         75 / <- EXT6 /EXTLATCH -> / 29                 S-PPU2                  74 / <- EXT5 PALMODE -> / 30                                         73 / <- EXT4 /      O                                     72 / <- EXT3 \                                           71 / <- EXT2 SYSTEM CLK -> \ 31                                      70 / <- EXT1 +5V -- \ 32                                    69 / <- EXT0 /RESOUT0 <- \ 33                                  68 / -- GND /RESET -> \ 34                                67 / <> VDA7 GND -- \ 35                              66 / <> VDA6 FIELD ?? \ 36                            65 / <> VDA5 /OVER1 -> \ 37                          64 / <> VDA4                     Orientation: /PIXEL CLK IN -> \ 38                        63 / <> VDA3 /HCLD ?? \ 39                      62 / <> VDA2                         80         51 /VCLD ?? \ 40                    61 / <> VDA1                           |         | COLOR0 -> \ 41                  60 / <> VDA0                           .---. COLOR1 -> \ 42                59 / -- +5V                          81-|O Nintendo |-50 COLOR2 -> \ 43              58 / <> VDB7                             |   S-PPU2  | PRIO0 -> \ 44            57 / <> VDB6                          100-|    5C78  O|-31 PRIO1 -> \ 45          56 / <> VDB5                               \---' CHR0 -> \ 46        55 / <> VDB4                                 |         | CHR1 -> \ 47      54 / <> VDB3                                 01         30 CHR2 -> \ 48    53 / <> VDB2 CHR3 -> \ 49  52 / <> VDB1                     Legend: /OVER2 -> \ 50 51 / <> VDB0 \    /                               --[5C78]-- Power, n/a \  /                                ->[5C78]<- 5C78 input \ /                                <-[5C78]-> 5C78 output V                                 <>[5C78]<> Bidirectional ??[5C78]?? Unknown

Signal descrptions

 * COLORBURST CLK: 3.58 MHz clock.
 * /PIXEL CLK IN, /PIXEL CLK OUT: 5.37 MHz clock. In comes from S-PPU1. Out goes to expansion port pin 22.
 * SYSTEM CLK: 21.47727 MHz clock.
 * /RESOUT0: S-PPU1 reset.
 * /RESOUT1: The main reset signal, connected to the CPU, APU, cartridge, and expansion port.
 * /RESET: Reset from CIC.
 * /EXTLATCH: Controls H/V counter latching. Connected to joypad IO D7. Can be used with a light pen.
 * /OVER1, /OVER2: /OVER from S-PPU1.
 * /TRANSPARENT: This is believed to be high whenever an opaque (sprite or tilemap) pixel is drawn.
 * EXT7..0: Video input, connected to VDB7..0.
 * DIGITAL VIDEO ENABLE: When high, TST4..0, TST9..5, and TST14..10 are digital R4..0, G4..0, and B4..0 output. For correct digital video output, this should be connected to /OVER. As sold, this is connected to ground.
 * TST14..12: When DIGITAL VIDEO ENABLE is low, these control other kinds of data that can be outputted over the TST pins. Output correlated with VRAM accesses has been observed. As sold, these are connected to ground.