82C54 Datasheet, PDF (15/17 Pages) Intel Corporation – CHMOS PROGRAMMABLE INTERVAL TIMER

Timing Waveforms
A0 - A1
CS
DATA BUS
WR
82C54
(9)
tAW
(10)
tSW
tWA (11)
VALID
(13)
tDW
tWD (14)
(12)
tWW
FIGURE 17. WRITE
A0 - A1
CS
RD
DATA BUS
tAR (1)
tRA (3)
(2)
tSR
(4)
tRR
(5)
(7)
tRD
(6)
tDF
tAD
VALID
FIGURE 18. READ
RD, WR
(8) (15)
tRV
FIGURE 19. RECOVERY
WR
CLK
GATE
OUT
MODE
COUNT
(SEE NOTE)
(17)
tPWH
(19)
tR
tWC (28)
(18)
tPWL
(16)
tCLK
tGS
(23)
(24)
tGH
tF (20)
(22)
tGL
(21)
tGW
(23)
tGS
tCL (30)
tGH (24)
tOD (25)
(27)
tWO
tODG (26)
NOTE: LAST BYTE OF COUNT BEING WRITTEN
FIGURE 20. CLOCK AND GATE
4-15