W25P243A-4A Winbond, W25P243A-4A Datasheet - Page 5

• Manufacturer Part Number: W25P243A-4A
• Description: 64K X 64 BURST PIPELINED HIGH-SPEED CMOS STATIC RAM
• Manufacturer: Winbond

Truth Table, continued
Notes:
1. For a detailed definition of read/write, see the Write Table below.
2. An "X" means don't care, "1" means logic high, and "0" means logic low.
3. The OE pin enables the data output and is not sampled with the clock. All signals of the SRAM are sampled synchronously
4. On a write cycle that follows a read cycle, OE must be inactive prior to the start of write cycle to allow write data to setup to
WRITE TABLE
Read
Read
Write byte 1 I/O1 I/O8
Write byte 2 I/O9 I/O16
Write byte 2, byte 1
Write byte 3 I/O17 I/O24
Write byte 3, byte 1
Write byte 3, byte 2
Write byte 3, byte 2, byte 1
Write byte 4, I/O25 I/O32
Write byte 4, byte 1
Write byte 4, byte 2
Write byte 4, byte 2, byte 1
Write byte 4, byte 3
Write byte 4, byte 3, byte 1
Write byte 4, byte 3, byte 2
Write byte 4, byte 3, byte 2, byte 1
Write byte 5, I/O33 I/O40
Write byte 5, byte 1
Begin Write
Begin Write
Begin Write
Continue Write
Continue Write
Suspend Write
Suspend Write
with the bus clock except for the OE pin.
the SRAM. OE must also disable the output buffer prior to the finish of a write cycle to ensure the SRAM data hold timings
are met.
READ/WRITE FUNCTION
CYCLE
ADDRESS
External
Current
Current
Current
Current
USED
Next
Next
CE1
X
X
X
1
0
1
1
GW
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
CE2
X
X
X
X
X
X
1
BWE
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
CE3
X
X
X
X
X
X
- 5 -
0
BW8
X
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
ADSP
BW7
X
X
X
1
1
1
1
X
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
BW6
ADSC
X
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
1
1
1
Publication Release Date: August 1999
BW5
X
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
ADV
X
1
1
0
0
1
1
BW4
X
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
OE
X
X
X
X
X
X
X
W25P243A
BW3
X
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
DATA
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
BW2
Revision A3
X
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
WRITE*
Write
Write
Write
Write
Write
Write
Write
BW1
X
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0