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|| FILE: #9005.PLD|| PROJ: 20130517|| PART: G20V8-#9005|||| DEV : GAL20V8|||| DESC: I/O DECODER & CONTROL||||GAL20V8A||| INPUT| 1:A1, 2:A2, 3:A3, 4:A4, 5:A5, 6:A6, 7:A7, 8:IO0, 9:RW, 10:PHI2,| 11:EN, 13:RDYN, 14:RAMN, 23:-,|| OUTPUT| 22:DBE, 21:VDC, 20:PIA, 19:WFF, 18:CRD, 17:CWE, 16:RD, 15:WIO|| SIGNATURE: "9005 "|| ACTIVE-LOW: DBE, VDC, PIA, WFF, CRD, CWE, RD, WIO|| PROPERTY: "SIMPLE"||| --------------------------------------------------------|| IO SELECT => FF70-FF77 (65C02) - FC70-FC77 (65C816)| IOS = (IO0' & A7' & A6 & A5 & A4 & A3')|| R6545/HD6445 => FF70-FF71 / FC70-FC71| CRTC = (IOS & A2' & A1')|| REGISTRO WRITE ONLY => FF72| WREG = (IOS & A2' & A1 & RW')|| PIA 65C21 => FF74-FF77 / FC74-FC77| PIAS = (IOS & A2 & A1')|| RD => segnale OE per RAM| RD = (RW & PHI2)|| CRD, CWE => segnali read,write per HD6545 (qualificati con EN)| CRD = (CRTC & RW & EN)| CWE = (CRTC & RW' & EN)|| ABILITAZIONE CRTC e PIA| PIA = PIAS| VDC = CRTC|| CLOCK per registro FF| WFF = (WREG & RDYN)|| SEGNALE WAIT I/O| WIO = (CRTC # WREG)|| SEGNALE ABILITAZIONE 74x245| DBEIO = ((CRTC & EN) # (WREG & (EN # RDYN)) # (PIAS & PHI2))| DBEM = RAMN'| DBE = (DBEIO # DBEM)