CY7C008/009
CY7C018/019
Document #: 38-06041 Rev. *D
Page 10 of 19
Notes:
27. R/W must be HIGH during all address transitions.
28. A write occurs during the overlap (tSCE or tPWE) of a LOW CE or SEM.
29. tHA is measured from the earlier of CE or R/W or (SEM or R/W) going HIGH at the end of write cycle.
30. If OE is LOW during a R/W controlled write cycle, the write pulse width must be the larger of tPWE or (tHZWE + tSD) to allow the I/O drivers to turn off and data
to be placed on the bus for the required tSD. If OE is HIGH during an R/W controlled write cycle, this requirement does not apply and the write pulse can be
as short as the specified tPWE.
31. To access RAM, CE = VIL, SEM = VIH.
32. Transition is measured
±500 mV from steady state with a 5-pF load (including scope and jig). This parameter is sampled and not 100% tested.
33. During this period, the I/O pins are in the output state, and input signals must not be applied.
34. If the CE or SEM LOW transition occurs simultaneously with or after the R/W LOW transition, the outputs remain in the high-impedance state.
Switching Waveforms (continued)
tAW
tWC
tPWE
tHD
tSD
tHA
CE
R/W
OE
DATAOUT
DATA IN
ADDRESS
tHZOE
tSA
tHZWE
tLZWE
Write Cycle No. 1: R/W Controlled Timing[27, 28, 29, 30]
[32]
[32]
[30]
[31]
NOTE 33
NOTE 33
tAW
tWC
tSCE
tHD
tSD
tHA
CE
R/W
DATA IN
ADDRESS
tSA
Write Cycle No. 2: CE Controlled Timing[27, 28, 29, 34]
[28]