CY7C138 CYPRESS [Cypress Semiconductor], CY7C138 Datasheet - Page 8

• Manufacturer Part Number: CY7C138
• Description: 4K x 8/9 Dual-Port Static RAM
• Manufacturer: CYPRESS [Cypress Semiconductor]

Switching Waveforms
Notes:
24. Data I/O pins enter high impedance when OE is held LOW during write.
25. CE = HIGH for the duration of the above timing (both write and read cycle).
SEM OR CE
Semaphore Read After Write Timing, Either Side
Write Cycle No. 2: R/W Three-States Data I/Os (Either Port)
DATA OUT
ADDRESS
DATAIN
A
0
SEM
–A
R/W
R/W
I/O
OE
2
0
t
SA
(continued)
VALID ADDRESS
t
AW
t
SA
WRITE CYCLE
t
t
PWE
SCE
t
SD
DATA
t
IN
HA
VALID
t
t
SCE
HD
[25]
t
AW
t
HZWE
t
WC
t
SWRD
8
[21, 23, 24]
t
PWE
t
SOP
t
SOP
READ CYCLE
t
t
SD
AA
VALID ADDRESS
HIGH IMPEDANCE
DATA VALID
t
ACE
t
DOE
t
HD
t
LZWE
DATA
t
HA
OUT
VALID
t
OHA
CY7C138
CY7C139
C138-13
C138-12