251715 PLA/MMU

| Programmable Logic Array/Memory Controller | Also known as SuperPLA

MOS/CSG/Sharp 251715

MOS/CSG/Sharp 252535

PCB ASSY NO. usage:

250469

Pinout

           +-----\/-----+
     A13 ->|01        64|-- Vdd
     A14 ->|02        63|<- A12
     A15 ->|03        62|<- A11
   R/W_l ->|04        61|<- A10
 LORAM_l ->|05        60|<- A9
 HIRAM_l ->|06        59|<- A8
CHAREN_l ->|07        58|<- A7
      NMI =|08        57|<- A6
  RESTORE =|09        56|<- A5
  VA14_l ->|10        55|<- A4
  VA15_l ->|11        54|<- A3
   CIA2_l =|12        53|<- A2
CHAROM_l <-|13        52|<- A1
 BASIC_l <-|14        51|<- A0
KERNAL_l <-|15        50|-> ROMH_l
     Vss --|16        49|-> IO1_l
 COLRAM_l =|17        48|-- Vss
  CAS0_l ->|18        47|<- GAME_l
  CAS1_l ->|19        46|<- EXROM_l
  CAS2_l ->|20        45|-> IO2_l
  CAS3_l ->|21        44|-> ROML_l
CASRAM_l <-|22        43|= SID
RAM R/W_l =|23        42|= VA7
      MA6 =|24        41|= VA6
      MA3 =|25        40|= VIC_l
      MA0 =|26        39|<- BA
      MA2 =|27        38|<- AEC_l
      MA4 =|28        37|= Φ0
      MA1 =|29        36|= RAS_l
      MA5 =|30        35|<- CAS_l
      MA7 =|31        34|= CIA1_l
     N/C --|32        33|-- Vss
           +------------+

251715 has separate 4KB Color-RAM, U19 2114 (ASSY 250469 Rev.A, Rev.3, Rev.4)

252535 has integrated 4KB Color-RAM (ASSY 250469 Rev.B)

Function:

The 251715 and 252535 integrates the PLA (Programmable Logic Array) and other TTL chips from the Commodore 64 main board in one single IC.