Pin definitions – Cypress CY7C1354CV25 User Manual
Page 6
CY7C1354CV25
CY7C1356CV25
Document #: 38-05537 Rev. *H
Page 6 of 28
Pin Definitions
Pin Name
I/O Type
Pin Description
A0
A1
A
Input-
Synchronous
Address Inputs used to select one of the address locations. Sampled at the rising edge of
the CLK.
BW
a,
BW
b,
BW
c,
BW
d,
Input-
Synchronous
Byte Write Select Inputs, active LOW. Qualified with WE to conduct writes to the SRAM.
Sampled on the rising edge of CLK. BW
a
controls DQ
a
and DQP
a
, BW
b
controls DQ
b
and DQP
b
,
BW
c
controls DQ
c
and DQP
c
, BW
d
controls DQ
d
and DQP
d
.
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.
CE
1
Input-
Synchronous
Chip Enable 1 Input, active LOW. Sampled on the rising edge of CLK. Used in conjunction with
CE
2
and CE
3
to select/deselect the device.
CE
2
Input-
Synchronous
Chip Enable 2 Input, active HIGH. Sampled on the rising edge of CLK. Used in conjunction with
CE
1
and CE
3
to select/deselect the device.
CE
3
Input-
Synchronous
Chip Enable 3 Input, active LOW. Sampled on the rising edge of CLK. Used in conjunction with
CE
1
and
CE
2
to select/deselect the device.
OE
Input-
Asynchronous
Output Enable, 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
and 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.
DQ
S
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 addresses 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
a
–DQ
d
are placed in a tri-state condition. The outputs are automati-
cally 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.
DQP
X
I/O-
Synchronous
Bidirectional Data Parity I/O lines. Functionally, these signals are identical to DQ
[a:d].
During
write sequences, DQP
a
is controlled by BW
a
, DQP
b
is controlled by BW
b
, DQP
c
is controlled by
BW
c
, and DQP
d
is controlled by BW
d
.
MODE
Input Strap Pin
Mode Input. Selects the burst order of the device. Tied HIGH selects the interleaved 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.
TDO
JTAG serial output
Synchronous
Serial data-out to the JTAG circuit. Delivers data on the negative edge of TCK.
TDI
JTAG serial input
Synchronous
Serial data-In to the JTAG circuit. Sampled on the rising edge of TCK.
TMS
Test Mode Select
Synchronous
This pin controls the Test Access Port state machine. Sampled on the rising edge of TCK.
TCK
JTAG-Clock
Clock input to the JTAG circuitry.
V
DD
Power Supply
Power supply inputs to the core of the device.
V
DDQ
I/O Power Supply Power supply for the I/O circuitry.
V
SS
Ground
Ground for the device. Should be connected to ground of the system.