PAL20X10 PAL DESIGN SPECIFICATION P7063 (PMSI4007) BIRKNER/COLI 05/07/82 9-BIT COUNTER MMI SUNNYVALE, CALIFORNIA CLK D0 D1 D2 D3 D4 D5 D6 D7 D8 /LD GND /OC /CO Q8 Q7 Q6 Q5 Q4 Q3 Q2 Q1 Q0 VCC /Q0 := /LD*/Q0 ;HOLD Q0 + LD*/D0 ;LOAD D0 (LSB) :+: /LD ;COUNT /Q1 := /LD*/Q1 ;HOLD Q1 + LD*/D1 ;LOAD D1 :+: /LD* Q0 ;COUNT /Q2 := /LD*/Q2 ;HOLD Q2 + LD*/D2 ;LOAD D2 :+: /LD* Q0* Q1 ;COUNT /Q3 := /LD*/Q3 ;HOLD Q3 + LD*/D3 ;LOAD D3 :+: /LD* Q0* Q1* Q2 ;COUNT /Q4 := /LD*/Q4 ;HOLD Q4 + LD*/D4 ;LOAD D4 :+: /LD* Q0* Q1* Q2* Q3 ;COUNT /Q5 := /LD*/Q5 ;HOLD Q5 + LD*/D5 ;LOAD D5 :+: /LD* Q0* Q1* Q2* Q3* Q4 ;COUNT /Q6 := /LD*/Q6 ;HOLD Q6 + LD*/D6 ;LOAD D6 :+: /LD* Q0* Q1* Q2* Q3* Q4* Q5 ;COUNT /Q7 := /LD*/Q7 ;HOLD Q7 + LD*/D7 ;LOAD D7 :+: /LD* Q0* Q1* Q2* Q3* Q4* Q5* Q6 ;COUNT /Q8 := /LD*/Q8 ;HOLD Q8 + LD*/D8 ;LOAD D8 (MSB) :+: /LD* Q0* Q1* Q2* Q3* Q4* Q5* Q6* Q7 ;COUNT CO := /LD*/Q0* Q1* Q2* Q3* Q4* Q5* Q6* Q7* Q8 ;CARRY OUT (ANTICIPATE COUNT) + LD* D0* D1* D2* D3* D4* D5* D6* D7* D8 ;CARRY OUT (ANTICIPATE LOAD) FUNCTION TABLE CLK /OC /LD D8 D7 D6 D5 D4 D3 D2 D1 D0 /CO Q8 Q7 Q6 Q5 Q4 Q3 Q2 Q1 Q0 ; DATA IN DATA OUT ; CONTROL DDDDDDDDD QQQQQQQQQ ;CLK /OC /LD 876543210 /CO 876543210 COMMENT ------------------------------------------------------------------ C L L LLLLLLLLL H LLLLLLLLL LOAD C L H XXXXXXXXX H LLLLLLLLH INCREMENT C L L LLLLLLLLH H LLLLLLLLH LOAD C L H XXXXXXXXX H LLLLLLLHL INCREMENT C L L LLLLLLLHH H LLLLLLLHH LOAD C L H XXXXXXXXX H LLLLLLHLL INCREMENT C L L LLLLLLHHH H LLLLLLHHH LOAD C L H XXXXXXXXX H LLLLLHLLL INCREMENT C L L LLLLLHHHH H LLLLLHHHH LOAD C L H XXXXXXXXX H LLLLHLLLL INCREMENT C L L LLLLHHHHH H LLLLHHHHH LOAD C L H XXXXXXXXX H LLLHLLLLL INCREMENT C L L LLLHHHHHH H LLLHHHHHH LOAD C L H XXXXXXXXX H LLHLLLLLL INCREMENT C L L LLHHHHHHH H LLHHHHHHH LOAD C L H XXXXXXXXX H LHLLLLLLL INCREMENT C L L LHHHHHHHH H LHHHHHHHH LOAD C L H XXXXXXXXX H HLLLLLLLL INCREMENT C L L HHHHHHHHH L HHHHHHHHH LOAD (CARRY OUT) C L H XXXXXXXXX H LLLLLLLLL INCREMENT (ROLL OVER) C L L HHHHHHHLL H HHHHHHHLL LOAD C L H XXXXXXXXX H HHHHHHHLH INCREMENT L L H XXXXXXXXX H HHHHHHHLH HOLD C L H XXXXXXXXX H HHHHHHHHL INCREMENT C L H XXXXXXXXX L HHHHHHHHH INCREMENT (CARRY OUT) C L H XXXXXXXXX H LLLLLLLLL INCREMENT (ROLL OVER) X H X XXXXXXXXX Z ZZZZZZZZZ TEST HI-Z ------------------------------------------------------------------ DESCRIPTION THE 9-BIT SYNCHRONOUS COUNTER HAS PARALLEL LOAD, INCREMENT, AND HOLD CAPABILITIES. DATA (D8-D0) IS LOADED INTO THE OUTPUT REGISTER (Q8-Q0) WHEN THE LOAD INPUT IS TRUE (/LD=L) AND A POSITIVE EDGE PULSE IS RECEIVED ON THE CLOCK PIN (CLK). THE COUNTER WILL INCREMENT IF A CLOCK PULSE IS RECEIVED WITH THE LOAD INPUT BEING FALSE (/LD=H). THE OPERATION IS A HOLD IF NO CLOCK PULSE IS RECEIVED REGARDLESS OF ANY OTHER INPUTS. THE CARRY OUT PIN (/CO) SHOWS HOW TO IMPLEMENT A CARRY OUT USING A REGISTER BY ANTICIPATED ONE COUNT BEFORE THE TERMINAL COUNT IF COUNTING AND THE TERMINAL COUNT IF LOADING. OPERATIONS TABLE: /OC CLK /LD D8-D0 Q8-Q0 OPERATION ---------------------------------------------- H X X X Z HI-Z L L X X Q HOLD L C L D D LOAD L C H X Q PLUS 1 INCREMENT ----------------------------------------------