X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=z80comp2;a=blobdiff_plain;f=hw%2Fglue.pld;fp=hw%2Fglue.pld;h=059e8e1ddae0d5a23ba6d916c7115bebe7059a65;hp=0000000000000000000000000000000000000000;hb=a0a85eb847ff3bb5da13e78618efdcd1b9f588cf;hpb=b55f31d1ac4a1991f2ad7b2d17be06969ea25e47 diff --git a/hw/glue.pld b/hw/glue.pld new file mode 100644 index 0000000..059e8e1 --- /dev/null +++ b/hw/glue.pld @@ -0,0 +1,19 @@ +GAL16V8 +gluez80 + +A4 A5 A6 A7 A15 NC M1 MREQ IOREQ GND +RFSH RD WR NC /IACK UARTENP /UARTEN /RAMEN /ROMEN VCC + +ROMEN = /MREQ * RFSH * /A15 +RAMEN = /MREQ * RFSH * A15 +UARTEN = /IOREQ*M1*/A7*/A6*/A5*/A4*/RD + /IOREQ*M1*/A7*/A6*/A5*/A4*/WR +UARTENP = /IOREQ*M1*/A7*/A6*/A5*/A4*/RD + /IOREQ*M1*/A7*/A6*/A5*/A4*/WR +IACK = /IOREQ * /M1 + +DESCRIPTION +Z80 computer 2 glue logic and address decoding +/ROMEN enables the ROM for memory cycles from 0000h to 0fffh +/RAMEN enables the RAM for memory cycles from 1000h to ffffh +/UARTEN enables the DUART for I/O cycles from port 0 to 15 +UARTENP is the negation of /UARTEN, needed for the DUART wait state logic +/IACK signifies an interrupt acknowledge cycle