WCSN0436V1P
Pin Definitions
Pin Number
Name
A[16:0]
I/O
Description
50–44,
81–82, 99,
100, 32–37
Input-
Synchronous
Address Inputs used to select one of the 131,072 address locations. Sampled at
the rising edge of the CLK.
96–93
BWS[3:0] Input-
Synchronous
Byte Write Select Inputs, active LOW. Qualified with WE to conduct writes to the
SRAM. Sampled on the rising edge of CLK. BWS0 controls DQ[7:0] and DP0, BWS1
controls DQ[15:8] and DP1, BWS2 controls DQ[23:16] and DP2, BWS3 controls
DQ[31:24] and DP3. See Write Cycle Description table for details.
88
85
WE
Input-
Synchronous
Write Enable Input, active LOW. Sampled on the rising edge of CLK if CEN is active
LOW. This signal must be asserted LOW to initiate a write sequence.
ADV/LD Input-
Synchronous
Advance/Load Input used to advance the on-chip address counter or load a new
address. When HIGH (and CEN is asserted LOW) the internal burst counter is
advanced. When LOW, a new address can be loaded into the device for an access.
After being deselected, ADV/LD should be driven LOW in order to load a new
address.
89
98
97
92
86
CLK
CE1
CE2
CE3
OE
Input-Clock
Clock Input. Used to capture all synchronous inputs to the device. CLK is qualified
with CEN. CLK is only recognized if CEN is active LOW.
Input-
Synchronous
Chip Enable 1 Input, active LOW. Sampled on the rising edge of CLK. Used in
conjunction with CE2, and CE3 to select/deselect the device.
Input-
Synchronous
Chip Enable 2 Input, active HIGH. Sampled on the rising edge of CLK. Used in
conjunction with CE1 and CE3 to select/deselect the device.
Input-
Synchronous
Chip Enable 3 Input, active LOW. Sampled on the rising edge of CLK. Used in
conjunction with CE1 and CE2 to select/deselect the device.
Input-
Output Enable, active LOW. Combined with the synchronous logic block inside the
Asynchronous device to control the direction of the I/O pins. When LOW, the I/O pins are allowed
to behave as outputs. When deasserted HIGH, I/O pins are three-stated, and act
as inputdatapins. OEis masked duringthedataportion of awrite sequence, during
the first clock when emerging from a deselected state, when the device has been
deselected.
87
CEN
Input-
Synchronous
Clock Enable Input, active LOW. When asserted LOW the clock signal is recog-
nized by the SRAM. When deasserted HIGH the Clock signal is masked. Since
deasserting CEN does not deselect the device, CEN can be used to extend the
previous cycle when required.
29–28,
25–22,
19–18,
13–12, 9–6,
3–2, 79–78,
75–72,
69–68, 63–62
59–56, 53–52
DQ[31:0] I/O-
Synchronous
Bidirectional Data I/O lines. As inputs, they feed into an on-chip data register that
is triggered by the rising edge of CLK. As outputs, they deliver the data contained
in the memory location specified by A[16:0] during the previous clock rise of the
read cycle. The direction of the pins is controlled by OE and the internal control
logic. When OE is asserted LOW, the pins can behave as outputs. When HIGH,
DQ[31:0] are placed in a three-state condition. The outputs are automatically
three-stated during the data portion of a write sequence, during the first clock when
emerging from a deselected state, and when the device is deselected, regardless
of the state of OE.
30, 1, 80 51
31
DP[3:0]
MODE
I/O-
Synchronous
Bidirectional Data Parity I/O lines. Functionally, these signals are identical to
DQ[31:0]. During write sequences, DP0 is controlled by BWS0, DP1 is controlled by
BWS1, DP2 is controlled by BWS2, and DP3 is controlled by BWS3.
Input Strap pin Mode Input. Selects the burst order of the device. Tied HIGH selects the inter-
leaved burst order. Pulled LOW selects the linear burst order. MODE should not
change states during operation. When left floating MODE will default HIGH, to an
interleaved burst order.
15, 16, 41, 65, VDD
66, 91
Power Supply Power supply inputs to the core of the device. Should be connected to 3.3V power
supply.
4, 11, 14, 20, VDDQ
27, 54, 61, 70,
77
I/O Power
Supply
Power supply for the I/O circuitry. Should be connected to a 3.3V power supply.
Document #: 38-05246 Rev. **
Page 3 of 14
WEIDA [ WEIDA SEMICONDUCTOR, INC. ]
