PRELIMINARY
Switching Waveforms
Read Cycle No. 1 (Either Port Address Access)[21,22,23]
tRC
ADDRESS
DATA OUT
tAA
tOHA
PREVIOUS DATA VALID
Read Cycle No. 2 (Either Port CE/OE Access)[21,24,25]
CE and
LB or UB
OE
DATA OUT
ICC
CURRENT
ISB
tACE
tDOE
tLZOE
tLZCE
tPU
Read Cycle No. 3 (Either Port)[21,23,24,25]
tRC
ADDRESS
tAA
UB or LB
CE
DATA OUT
tLZCE
tABE
tACE
tLZCE
CY7C027/028
CY7C037/038
DATA VALID
tOHA
tHZCE
tHZOE
DATA VALID
tPD
tOHA
tHZCE
tHZCE
Notes:
21. R/W is HIGH for read cycles.
22. Device is continuously selected CE = VIL and UB or LB = VIL. This waveform cannot be used for semaphore reads.
23. OE = VIL.
24. Address valid prior to or coincident with CE transition LOW.
25. To access RAM, CE = VIL, UB or LB = VIL, SEM = VIH. To access semaphore, CE = VIH, SEM = VIL.
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