Name      t2kmem;

Assembly  0001;
Revision  A 1.0;
PartNo    U3 ATF1504AS;
Device    f1504ispplcc44;

Company   Retrotronics.org;
Designer  Alan H.;
Location  None;
Date      September 2017;

property ATMEL { xor_synthesis=on };
property ATMEL { logic_doubling=on };
property ATMEL { jtag=off };
PROPERTY ATMEL { preassign keep };
PROPERTY ATMEL { TMS_pullup=off };
PROPERTY ATMEL { TDI_pullup=off };


/*
 * Pin assignments
 */

Pin  1 = !RESET;

Pin 43 = A0;
Pin 41 = A1;
Pin 37 = A2;
Pin 39 = A3;
Pin 40 = A4;
Pin 33 = A5;
Pin 36 = A6;

Pin 31 = D0;
Pin 29 = D1;
Pin 27 = D2;
Pin 24 = D3;
Pin 20 = D4;
Pin 21 = D5;
Pin 28 = D6;
Pin 25 = D7;
Pin  8 = !BHE;

Pin  2 = MEMWRn;
Pin 14 = MEMRDn;
Pin  9 = !IOWR;
Pin  5 = !IORD;
Pin 44 = !DEN;
Pin  4 = ARDYn;
Pin  6 = !PCS5;
Pin 11 = !MCS0;
Pin 12 = !MCS1;

Pin 26 = !RAM_CE0;
Pin 34 = !RAM_CE1;

Pin 18 = !DIP1;
Pin 19 = !DIP2;
Pin 16 = !DIP3;
Pin 17 = !DIP4;

Pin 13 = A17;
Pin  7 = A18;
Pin 32 = A19;



BANK_CE = (A18 $ A19);
/* # (A19 &  A18 & !A17);*/

BYTE_LO = !A0;
BYTE_HI = BHE;

RAM_CE0 = BYTE_LO & BANK_CE;
RAM_CE1 = BYTE_HI & BANK_CE;

ARDYn = MEMWRn & MEMRDn;
ARDYn.oe = RAM_CE0 # RAM_CE1;