PRELIMINARY
CY7C1471V25
CY7C1473V25
CY7C1475V25
Document #: 38-05287 Rev. *E
Page 8 of 30
Pin Definitions
Name
I/O
Description
A0, A1, A
Input-
Synchronous
Address Inputs used to select one of the address locations. Sampled at the
rising edge of the CLK. A[1:0] are fed to the two-bit burst counter.
BWA, BWB,
BWC, BWD,
BWE, BWF,
BWG, BWH
Input-
Synchronous
Byte Write Inputs, active LOW. Qualified with WE to conduct writes to the SRAM.
Sampled on the rising edge of CLK.
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.
CLK
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.
CE1
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.
CE2
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.
CE3
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.
OE
Input-
Asynchronous
Output Enable, asynchronous input, active LOW. Combined with the
synchronous logic block inside the 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 tri-stated, and act as input data pins. OE is masked during the data
portion of a write sequence, during the first clock when emerging from a deselected
state, when the device has been deselected.
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.
ZZ
Input-
Asynchronous
ZZ “Sleep” Input. This active HIGH input places the device in a non-time critical
“sleep” condition with data integrity preserved. During normal operation, this pin can
be connected to VSS or left floating.
DQs
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 the addresses presented during the previous
clock rise of the read cycle. The direction of the pins is controlled by OE. When OE
is asserted LOW, the pins behave as outputs. When HIGH, DQs and DQPX are
placed in a tri-state condition.The outputs are automatically tri-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.
DQPX
I/O-
Synchronous
Bidirectional Data Parity I/O Lines. Functionally, these signals are identical to
DQs. During write sequences, DQPX is controlled by BWX correspondingly.
MODE
Input Strap Pin
Mode Input. Selects the burst order of the device.
When tied to Gnd selects linear burst sequence. When tied to VDD or left floating
selects interleaved burst sequence.
VDD
Power Supply
Power supply inputs to the core of the device.
VDDQ
I/O Power Supply
Power supply for the I/O circuitry.
VSS
Ground
Ground for the device.
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