44307C.txt

PAL16L8
JLB 26NOV86
44307C,13D,CYCLK

/TERM /CC0 /CC1 /CC2 /CC3 /FORM /BRK /RWCS /TRAP GND
VEX /MACLK /MAP /ETRAP UCLK /EORF CYD WRFSTB /MCLK VCC

; CYCLE CONTROL CLOCK GENERATOR.

IF (VCC) MCLK = RWCS * /CC3               ;  BECAUSE THE CONTROL STORE ADDRESS TO B
              + RWCS * CC2                ; IN PRESENTED ONTO MA. THEN THE ADDRESS
                                          ; STORE LOCATION TO BE EXECUTED IS PRESE

IF (VCC) /WRFSTB = CC3                    ; b ON 75NS CYCLES TO PROVIDE A WRITE PU
                 + CC2
                 + CC1
                 + /CC0
                 + TERM

IF (VCC) /CYD = CC3                       ; d + e + f WRITE PULSE USED IN WMAP AND WCA
              + /CC1
              + /CC2 * CC0
              + TERM


IF (VCC) EORF = /CC3 * /CC2 * CC1 * /CC0 * /TERM ; d MISC WRITE PULSE.

IF (VCC) /UCLK = CC3                       ; ON c ON ALL MEMORY REQUESTS.
               + CC2                       ; USED TO UPDATE USED BITS AND CLOCK TRA
               + /CC1
               + /CC0
               + TERM                      ; EXPERIMENT TO SEE IF UCLK ON TERM WAS DANGEROUS.

IF (VCC) MAP = FORM * /BRK * CC2 * /TERM   ; MUST NOT COME BEFORE ALL SHORT CYCLES

IF (VCC) MACLK = MAP * /CC3 * CC2 * CC1    ; e+f CAPTURE CD FROM MEMORY THROUGH M
               + TRAP * /CC3 * CC1 * /CC0  ; d+e CAPTURE TRAP VECTOR
               + RWCS * /CC3               ; CAPTURE MICROADDRESS AFTER EWCA
               + RWCS * CC2 * /CC1         ; TURNED OFF

IF (VCC) ETRAP = /TERM * /VEX * CC3 ; ENABLE TRAPS ONLY OUTSIDE t OR a
               + /TERM * /VEX * CC2 ; UNSTABLE TRAP IN THIS PERIOD
               + /TERM * /VEX * CC1 ; CAN DESTROY MA !
               + /TERM * /VEX * CCO ; DISABLE TRAPS DURING VEX

DESCRIPTION

;280287 JLB: ECREQ TO LOCAL MEMORY GIVES TWO CGNTS. A SHORTER EORF.
; I.E. ONLY ON e AND NOT ON f, WILL MAKE ECREQ GO OFF 25NS SOONER
;AND HOPEFULLY CURE THIS.
;010387 JLB: ETRAP NEW OUTPUT. WILL DISABLE TRAP ON t AND a.
;080387 JLB: REMOVED UCLK ON CACHE HIT CYCLES.
;160387 JLB: REMOVED TERM IN MCLK AND MACLK TO PROVIDE SYMMETRICAL
;            CLOCKS IN 50 NS CYCLES.
;170387 JLB/CJTC: REMOVED MREQ - NEEDED THE INPUT FOR NEW SIGNAL VEX.
;            VEX SHOULD DISABLE TRAPS.
;180387 JLB: EORF ON d ONLY. MACLK ON e + f ON MAP.
;
; 270487 : M3202B
;B 300687 JLB: CYD POSITIVE POLARITY.
;C 130787 JLB: CYD FROM d TO f.