PAL20X8 PAL DESIGN SPECIFICATION P7011 SAEED KAZMI 04/28/81 BCD/HEX COUNTER MMI SUNNYVALE, CALIFORNIA CK /CLR HEX /C0 /C1 /C2 /C3 /C4 /C5 /C6 /CIN GND /OC /COUT1 A0 A1 A2 A3 B0 B1 B2 B3 /COUT2 VCC IF (VCC) COUT2 = /CLR*B0*B1*B2*B3 ;HEX COUNT CARRY OUT + /CLR* /HEX*B0*B3 ;BCD COUNT CARRY OUT /B3 := CLR ;CLEAR + /CLR*/B3 ;HOLD, MSB OF STAGE 2 :+:/CLR*C0*C1*C2*C3*C4*C5*C6*CIN*B0*B1*B2 ;INCREMENT + /CLR* /HEX*B0*B3 ;CLEAR IF BCD & COUNT=9 /B2 := CLR + /CLR*/B2 :+:/CLR*C0*C1*C2*C3*C4*C5*C6*CIN*B0*B1 /B1 := CLR + /CLR*/B1 :+:/CLR* HEX*C0*C1*C2*C3*C4*C5*C6*CIN*B0 + /CLR* /HEX*C0*C1*C2*C3*C4*C5*C6*CIN*B0*/B3 ;CLEAR IF BCD & COUNT=9 /B0 := CLR + /CLR*/B0 ;HOLD, LSB OF STAGE 2 :+:/CLR*C0*C1*C2*C3*C4*C5*C6*CIN /A3 := CLR + /CLR*/A3 ;HOLD, MSB OF STAGE 1 :+:/CLR*C0*C1*C2*C3*C4*C5*C6*A0*A1*A2 + /CLR* /HEX*A0*A3 ;CLEAR IF BCD & COUNT=9 /A2 := CLR + /CLR*/A2 :+:/CLR*C0*C1*C2*C3*C4*C5*C6*A0*A1 /A1 := CLR + /CLR*/A1 :+:/CLR* HEX*C0*C1*C2*C3*C4*C5*C6*A0 + /CLR* /HEX*C0*C1*C2*C3*C4*C5*C6*A0*/A3 ;CLEAR IF BCD & COUNT=9 /A0 := CLR + /CLR*/A0 ;HOLD, LSB OF STAGE 1 :+:/CLR*C0*C1*C2*C3*C4*C5*C6 IF (VCC) COUT1 = /CLR* HEX*A0*A1*A2*A3 ;HEX COUNT, INT. CARRY + /CLR*/HEX*A0*A3 ;BCD COUNT, INT. CARRY FUNCTION TABLE HEX CLR CK OC C0 C1 C2 C3 C4 C5 C6 COUT2 B3 B2 B1 B0 COUT1 A3 A2 A1 A0 CIN ;H C C O C C C C C C C C B B B B C A A A A C ;E L K C 0 1 2 3 4 5 6 O 3 2 1 0 O 3 2 1 0 I ;X R U U N ; T T ; 2 1 COMMENT ----------------------------------------------------------------------- X H C H L L L L L L L L L L L L L L L L L L CLEAR X H C H H H H H H H H L L L L L L L L L L H HOLD, HEX COUNT 00 H L C H H H H H H H H L L L L H L L L L H H HEX COUNT 11 H L C H H H H H H H H L L L H L L L L H L H 22 H L C H H H H H H H H L L L H H L L L H H H 33 H L C H H H H H H H H L L H L L L L H L L H 44 H L C H H H H H H H H L L H L H L L H L H H 55 H L C H H H H H H H H L L H H L L L H H L H 66 H L C H H H H H H H H L L H H H L L H H H H 77 H L C H H H H H H H H L H L L L L H L L L H 88 H L C H H H H H H H H L H L L H L H L L H H 99 H L C H H H H H H H H L H L H L L H L H L H AA H L C H H H H H H H H L H L H H L H L H H H BB H L C H H H H H H H H L H H L L L H H L L H CC H L C H H H H H H H H L H H L H L H H L H H DD H L C H H H H H H H H L H H H L L H H H L H EE H L C H H H H H H H H H H H H H H H H H H H FF H L C H H H H H H H H L L L L L L L L L L H BCD COUNT 00 L L C H H H H H H H H L L L L H L L L L H H 11 L L C H H H H H H H H L L L H L L L L H L H 22 L L C H H H H H H H H L L L H H L L L H H H 33 L L C H H H H H H H H L L H L L L L H L L H 44 L L C H H H H H H H H L L H L H L L H L H H 55 L L C H H H H H H H H L L H H L L L H H L H 66 L L C H H H H H H H H L L H H H L L H H H H 77 L L C H H H H H H H H L H L L L L H L L L H 88 L L C H H H H H H H H H H L L H H H L L H H 99 L L C H H H H H H H H L L L L L L L L L L H 100 ----------------------------------------------------------------------- DESCRIPTION FOUR IDENTICALLY PROGRAMMED PAL DEVICES ARE USED TO DRIVE EIGHT OF HP'S NUMERIC AND HEX INDICATORS (5082-7340). EACH PAL CONSISTS OF TWO FOUR BIT COUNTERS. STAGE 1 IS THE LSB AND STAGE 2 IS THE MSB. CARRYOUT OF STAGE 1 IS CALLED INTERNAL CARRY (COUT1) AND IS FED EXTERNALLY TO STAGE 2. COUT2 IS FED INTO THE NEXT PAL. CARRYOUT AND INTERNAL CARRYS FROM THE LOWER PAL ARE CONNECTED TO ALL OF THE HIGHER PAL DEVICES TO PERFORM THE CARRY LOOK AHEAD OPERATION. THE BCD/HEX COUNTER HAS BUILT IN TESTABILITY. COUT1 IS CONNECTED TO CIN EXTERNALLY AND CAN FORCE COUT1 TO GO HIGH, THUS STAGE 2 MAY START COUNTING AT THE SAME TIME AS STAGE 1 WHICH REDUCES THE NUMBER OF TEST VECTORS IN THE FUNCTION TABLE. THIS COUNTER OPERATES AT 10 MHz AND CAN PERFORM THE FOLLOWING OPERATIONS: HEX CLR OPERATION -------------------------- X H CLEAR L L COUNT BCD H L COUNT HEX --------------------------