CY7C1355CCY7C1357C
Document #: 38-05539 Rev. *E Page 7 of 28
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
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.
CE1Input-
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.
CE2Input-
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.
CE3Input-
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 recognized 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. For normal operation, this pin has to be LOW or left
floating. ZZ pin has an internal pull-down.
DQsI/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.
DQPXI/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.
TDO JTAG serial output
Synchronous Serial data-out to the JTAG circuit. Delivers data on the negative edge of TCK. If the JTAG
feature is not being utilized, this pin should be left unconnected. This pin is not available on
TQFP packages.
TDI JTAG serial input
Synchronous Serial data-In to the JTAG circuit. Sampled on the rising edge of TCK. If the JTAG feature
is not being utilized, this pin can be left floating or connected to VDD through a pull up resistor.
This pin is not available on TQFP packages.
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