PAL20X4 PAL DESIGN SPECIFICATION P7012 MIKE VOLPIGNO 07/15/81 64K DYNAMIC RAM REFRESH CONTROLLER MMI FIELD APPLICATIONS ENGINEER NEWTON, MASSACHUSETTS COUNT A0 A1 A2 A3 A8 A9 A10 A11 REFEN ROWEN GND /OC /CARRYOUT O3 O2 C3 C2 C1 C0 O1 O0 /CARRYIN VCC /C0 := /C0 ;INCR REF ADDRESS COUNTER + REFEN*/ROWEN ;SET REF COUNTER :+: CARRYIN ;INCR REF COUNTER + REFEN*/ROWEN ;SET REF COUNTER /C1 := /C1 ;INCR REF COUNTER + REFEN*/ROWEN ;SET REF COUNTER :+: CARRYIN* C0 ;INCR REF COUNTER + REFEN*/ROWEN ;SET REF COUNTER /C2 := /C2 ;INCR REF COUNTER + REFEN*/ROWEN ;SET REF COUNTER :+: CARRYIN* C0* C1 ;INCR REF COUNTER + REFEN*/ROWEN ;SET REF COUNTER /C3 := /C3 ;INCR REF COUNTER + REFEN*/ROWEN ;SET REF COUNTER :+: CARRYIN* C0* C1* C2 ;INCR REF COUNTER + REFEN*/ROWEN ;SET REF COUNTER IF (VCC) /O0 = /A0*/REFEN* ROWEN ;SELECT LOWER ADDRESS + /A8*/REFEN*/ROWEN ;SELECT UPPER ADDRESS + /C0* REFEN* ROWEN ;SELECT REFRESH ADDRESS IF (VCC) /O1 = /A1*/REFEN* ROWEN ;SELECT LOWER ADDRESS + /A9*/REFEN*/ROWEN ;SELECT UPPER ADDRESS + /C1* REFEN* ROWEN ;SELECT REFRESH ADDRESS IF (VCC) /O2 = /A2* /REFEN* ROWEN ;SELECT LOWER ADDRESS + /A10*/REFEN*/ROWEN ;SELECT UPPER ADDRESS + /C2* REFEN* ROWEN ;SELECT REFRESH ADDRESS IF (VCC) /O3 = /A3* /REFEN* ROWEN ;SELECT LOWER ADDRESS + /A11*/REFEN*/ROWEN ;SELECT UPPER ADDRESS + /C3* REFEN* ROWEN ;SELECT REFRESH ADDRESS IF (VCC) CARRYOUT = CARRYIN* C0* C1* C2* C3 ;CARRY OUT FUNCTION TABLE A0 A1 A2 A3 A8 A9 A10 A11 COUNT /OC REFEN ROWEN /CARRYIN /CARRYOUT O3 O2 O1 O0 C3 C2 C1 C0 ;--DATA- --CARRIES-- ;AAAAAAAA ----CONTROLS--- / / ; 11 COU / REF ROW CARRY CARRY OOOO CCCC ;32101098 NT OC EN EN IN OUT 3210 3210 COMMENTS ------------------------------------------------------------------------- XXXXXXXX C L H L H H HHHH HHHH SET REF CNTR XXXXLLLL C L L L H H LLLL HHHH UPPER ADDR LOW XXXXHHHH C L L L H H HHHH HHHH UPPER ADDR HI LLLLXXXX C L L H H H LLLL HHHH LOWER ADDR LOW HHHHLLLL C L L H H H HHHH HHHH LOWER ADDR HI XXXXXXXX C L H H L H LLLL LLLL INCR REF ADDR XXXXXXXX C L H H L H LLLH LLLH XXXXXXXX C L H H L H LLHL LLHL XXXXXXXX C L H H L H LLHH LLHH XXXXXXXX C L H H L H LHLL LHLL XXXXXXXX C L H H L H LHLH LHLH XXXXXXXX C L H H L H LHHL LHHL XXXXXXXX C L H H L H LHHH LHHH XXXXXXXX C L H H L H HLLL HLLL XXXXXXXX C L H H L H HLLH HLLH XXXXXXXX C L H H L H HLHL HLHL XXXXXXXX C L H H L H HLHH HLHH XXXXXXXX C L H H L H HHLL HHLL XXXXXXXX C L H H L H HHLH HHLH XXXXXXXX C L H H L H HHHL HHHL XXXXXXXX C L H H L L HHHH HHHH CARRY OUT XXXXXXXX X H X X X X XXXX ZZZZ TEST HI-Z ------------------------------------------------------------------------- DESCRIPTION TWO IDENTICALLY PROGRAMMED PAL20X4 CAN PERFORM THE 64K DYNAMIC RAM REFRESH CONTROL FUNCTION. EITHER COLUMN OR ROW ADDRESSES TO THE RAM ARE SELECTED DEPENDING ON ROW ENABLE (ROWEN). AN ADDRESS COUNTER (C3-C0) IS SELECTED DURING REFRESH WHEN ROW ENABLE (ROWEN) IS HIGH. THESE OPERATIONS ARE EXERCISED IN THE FUNCTION TABLE AND SUMMERIZED IN THE OPERATIONS TABLE: /OC COUNT REFEN ROWEN O3-O0 OPERATION ----------------------------------------------------------- H X X X Z HI-Z L C L L A3-A0 SELECT LOW ADDR BITS L C L H A11-A8 SELECT UPPER ADDR BITS L C H H C3-C0 SELECT REFRESH ADDR BITS L C H L H SET REFRESH COUNTER -----------------------------------------------------------