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CY7C024/024A/0241
CY7C025/0251
Document #: 38-06035 Rev. *D
Page 11 of 21
Switching Waveforms
Notes
23. R/W is HIGH for read cycles
24. Device is continuously selected CE = VIL and UB or LB = VIL. This waveform cannot be used for semaphore reads.
25. OE = VIL.
26. Address valid prior to or coincident with CE transition LOW.
27. To access RAM, CE = VIL, UB or LB = VIL, SEM = VIH. To access semaphore, CE = VIH, SEM = VIL.
tRC
tAA
tOHA
DATA VALID
PREVIOUS DATA VALID
DATA OUT
ADDRESS
tOHA
Figure 4. Read Cycle No. 1 (Either Port Address Access)[23, 24, 25]
tACE
tLZOE
tDOE
tHZOE
tHZCE
DATA VALID
tLZCE
tPU
tPD
ISB
ICC
DATA OUT
OE
CE and
LB or UB
CURRENT
Figure 5. Read Cycle No. 2 (Either Port CE/OE Access)[23, 26, 27]
UB or LB
DATA OUT
tRC
ADDRESS
tAA
tOHA
CE
tLZCE
tABE
tHZCE
tHZCE
tACE
tLZCE
Figure 6. Read Cycle No. 3 (Either Port)[23, 25, 26, 26, 27]
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