:
WCSS0232V1P
Write Cycle Descriptions
[4,5,6]
Function
Read
Read
Write Byte 0 - DQ
[7:0]
Write Byte 1 - DQ
[15:8]
Write Bytes 1, 0
Write Byte 2 - DQ
[23:16]
Write Bytes 2, 0
Write Bytes 2, 1
Write Bytes 2, 1, 0
Write Byte 3 - DQ
[31:24]
Write Bytes 3, 0
Write Bytes 3, 1
Write Bytes 3, 1, 0
Write Bytes 3, 2
Write Bytes 3, 2, 0
Write Bytes 3, 2, 1
Write All Bytes
Write All Bytes
GW
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
BWE
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
X
BW
3
X
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
X
BW
2
X
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
X
BW
1
X
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
X
BW
0
X
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
X
Maximum Ratings
(Above which the useful life may be impaired. For user guide-
lines, not tested.)
Storage Temperature
..................................... −65°C
to +150°C
Ambient Temperature with
Power Applied..................................................
−55°C
to +125°C
Supply Voltage on V
DD
Relative to GND.........−0.5V to +4.6V
DC Voltage Applied to Outputs
in High Z State
[7]
.....................................−0.5V
to V
DDQ
+ 0.5V
DC Input Voltage
[7]
..................................−0.5V
to V
DDQ
+ 0.5V
Current into Outputs (LOW) ........................................ 20 mA
Static Discharge Voltage .......................................... >2001V
(per MIL-STD-883, Method 3015)
Latch-Up Current.................................................... >200 mA
Operating Range
Range
Com’l
Ambient
Temperature
[8]
0°C to +70°C
V
DD
3.3V
−5%/+10%
V
DDQ
3.3V
−5%/+10%
Notes:
4. X=”Don't Care”, 1=Logic HIGH, 0=Logic LOW.
5. The SRAM always initiates a read cycle when ADSP asserted, regardless of the state of GW, BWE, or BW
[3:0]
. Writes may occur only on subsequent clocks
after the ADSP or with the assertion of ADSC. As a result, OE must be driven HIGH prior to the start of the write cycle to allow the outputs to three-state. OE is
a “don't care” for the remainder of the write cycle.
6. OE is asynchronous and is not sampled with the clock rise. It is masked internally during write cycles. During a read cycle DQ=High-Z when OE is inactive or
when the device is deselected, and DQ=data when OE is active.
7. Minimum voltage equals –2.0V for pulse durations of less than 20 ns.
8. T
A
is the case temperature.
6
WEIDA [ WEIDA SEMICONDUCTOR, INC. ]
