PAL16L8 PAT8038 **-1110-** MK,85-05-08 DS60 PARITY GENERATION/DETECTION CONTROL NC1 NC2 NC3 ES1 ES0 MPI ODD NC4 NC5 GND TST LDR EDR PIN PBL NC6 ER1 MPO ERR VCC ;EQUATIONS: IF(VCC) /LDR = ES1 ;LATCH DATA IF(VCC) /EDR = ES1*/ES0 ;WRITE - ENABLE DR TO BUS IF(VCC) /PBL = /MPI*/ES1*/TST + ;PARITY BIT TRANSPARENT /PBL* ES1*/TST + ; " " LATCHED /MPI*/PBL*/TST ;NO HAZARD IF(VCC) /PIN = /PBL* ES1 + ;READ TEST - LATCHED PARITY /ES0*/ES1 + ;WRITE - ALLWAYS LOW /MPI*/ES1* ES0 ;NOT WRITE - PREPARE IF(/ES0) /MPO = /ODD ;WRITE - PARITY BIT TO MEMORY IF(VCC) /ERR = /ES1 + ;LOW IF NO TEST ES1*/ODD ;ERROR IF WRONG PARITY IF(VCC) /ER1 = /ES1 + ;LOW IF NO TEST ES1*/ODD ;ERROR IF WRONG PARITY FUNCTION TABLE: TST ES1 ES0 MPI ODD LDR EDR PBL PIN MPO ERR ER1 ;T EE MO L E PP M E E ;S SS PD D D BI P R R ;T 10 ID R R LN O R 1 ------------------------ H HH HH L H HH Z H H H LH HL H H HH Z L L H HL XL L L HH L L L H HL XH L L HH H H H L HX HX L X HH X X X L LL LX H H LL X L L ------------------------ DESCRIPTION: THIS CIRCUIT PROVIDES CONTROL OF PARITY ADAPTER IN ORDER TO SIMULATE EDAC COMPATIBILITY. INPUT SIGNALS: ES0 - EDAC S0 CONTROL ES1 - EDAC S1 CONTROL MPI - MEMORY PARITY BIT (INPUT) ODD - PARITY GENERATOR OUTPUT TST - TEST INPUT (FOR TEST PATTERN ONLY) OUTPUT SIGNALS: LDR - LATCH DATA REGISTER EDR - ENABLE DATA REGISTER OUTPUTS PIN - PARITY GENERATOR INPUT PBL - LATCHED PARITY BIT FROM MEMORY MPO - MEMORY PARITY BIT (OUTPUT) ERR - PARITY ERROR