PAL20X10 PAL DESIGN SPECIFICATION P7077 FRANK LEE 08/03/82 REFRESH CLOCK GENERATOR MMI SUNNYVALE, CALIFORNIA CLK /LD F3 F2 F1 F0 M3 M2 M1 M0 /HOLD GND /OC RFCK Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7 /INIT VCC INIT := /Q7*/Q6*/Q5*/Q4*/Q3*/Q2*/Q1*/Q0 ;END OF COUNT + LD ;LOAD /Q0 := /INIT*/Q0 ;DECREMENT :+: /INIT*/HOLD ;HOLD /Q1 := /INIT*/Q1 ;DECREMENT :+: /INIT*/HOLD*/Q0 ;HOLD /Q2 := INIT ;LOAD IN 0 + /INIT*/Q2 ;DECREMENT :+: /INIT*/HOLD*/Q0*/Q1 ;HOLD /Q3 := /INIT*/Q3 ;DECREMENT :+: /INIT*/HOLD*/Q0*/Q1*/Q2 ;HOLD /Q4 := INIT*/F0 ;LOAD IN F0 + /INIT*/Q4 ;DECREMENT :+: /INIT*/HOLD*/Q0*/Q1*/Q2*/Q3 ;HOLD /Q5 := INIT*/F1 ;LOAD IN F1 + /INIT*/Q5 ;DECREMENT :+: /INIT*/HOLD*/Q0*/Q1*/Q2*/Q3*/Q4 ;HOLD /Q6 := INIT*/F2 ;LOAD IN F2 + /INIT*/Q6 ;DECREMENT :+: /INIT*/HOLD*/Q0*/Q1*/Q2*/Q3*/Q4*/Q5 ;HOLD /Q7 := INIT*/F3 ;LOAD IN F3 + /INIT*/Q7 ;DECREMENT :+: /INIT*/HOLD*/Q0*/Q1*/Q2*/Q3*/Q4*/Q5*/Q6 ;HOLD /RFCK := M3*/Q7*/Q6* Q5 ;32 LOW STATES + M2*/Q7*/Q6*/Q5* Q4 ;16 LOW STATES :+: M1*/Q7*/Q6*/Q5*/Q4* Q3 ;8 LOW STATES + M0*/Q7*/Q6*/Q5*/Q4*/Q3* Q2 ;4 LOW STATES FUNCTION TABLE CLK /OC /LD /HOLD F3 F2 F1 F0 M3 M2 M1 M0 /INIT Q7 Q6 Q5 Q4 Q3 Q2 Q1 Q0 RFCK ; / / ; H I R ;C / / O N F ;L O L L FFFF MMMM I QQQQQQQQ C ;K C D D 3210 3210 T 76543210 K COMMEMTS -------------------------------------------------------------------------- C L L X LLHH LLHH L XXXXXXXX X READY TO LOAD COUNTER C L L H LLHH LLHH L LLHHHLHH X READY TO LOAD COUNTER C L H H LLHH LLHH H LLHHHLHH H COUNTER LOADED, READY TO COUNT DOWN C L H H LLHH LLHH H LLHHHLHL H COUNT DOWN C L H H LLHH LLHH H LLHHHLLH H COUNT DOWN C L L H LLLH LHHL L LLHHHLLL H READY TO LOAD COUNTER, COUNT DOWN C L H H LLLH LHHL H LLLHHLHH H COUNTER LOADED C L H H LLLH LHHL H LLLHHLHL L COUNT DOWN C L H H LLLH LHHL H LLLHHLLH L COUNT DOWN C L H H LLLH LHHL H LLLHHLLL L COUNT DOWN C L L H LLLH LHHL L LLLHLHHH L READY TO LOAD COUNTER, COUNT DOWN C L H H LLLL LHHL H LLLLHLHH L COUNTER LOADED C L H H LLLL LHHL H LLLLHLHL L COUNT DOWN C L H H LLLL LHHL H LLLLHLLH L COUNT DOWN C L H H LLLL LHHL H LLLLHLLL L COUNT DOWN C L H H LLLL LHHL H LLLLLHHH L COUNT DOWN C L H H LLLL LHHL H LLLLLHHL H COUNT DOWN, RFCK HIGH C L H H LLLL LHHL H LLLLLHLH H COUNT DOWN, RFCK HIGH C L H L LLLL LHHL H LLLLLHLH H HOLD C L H H LLLL LHHL H LLLLLHLL H COUNT DOWN C L H H LLLL LHHL H LLLLLLHH H COUNT DOWN C L H H LLLL LHHL H LLLLLLHL H COUNT DOWN C L H H LLLL LHHL H LLLLLLLH H COUNT DOWN C L H H LLLL LHHL H LLLLLLLL H COUNT DOWN C L H H LLLL LHHL L HHHHHHHH H COUNT DOWN, READY TO LOAD COUNTER C H X X XXXX XXXX Z ZZZZZZZZ Z HIGH IMPEDANCE TEST -------------------------------------------------------------------------- DESCRIPTION THE REFRESH CLOCK GENERATOR CAN GENERATE REFRESH CLOCK (RFCK) FOR THE DYNAMIC RAM CONTROLLERS. THE PERIOD OF RFCK DEPENDS ON F3-F0 WHILE THE DURATION OF RFCK BEING LOW DEPENDS ON M3-M0. FFFF RFCK PERIOD MMMM RFCK LOW DURATION 3210 (CYCLES) 3210 (CYCLES) ----------------- ----------------------- 0000 12 0000 0 0001 28 0001 4 0010 44 0010 8 0011 60 0011 12 0100 76 0100 16 0101 92 0101 20* 0110 108 0110 24 0111 124 0111 28 1000 140 1000 32 1001 156 1001 36* 1010 172 1010 40* 1011 188 1011 44* 1100 204 1100 48 1101 220 1101 52* 1110 236 1110 56 1111 252 1111 60 ----------------- ----------------------- *NOT ALLOWED DUE TO BAD WAVEFORMS