CY7C1306BV25
CY7C1303BV25
Document #: 38-05627 Rev. *A
Page 4 of 19
Pin Definitions
Name
I/O
Description
D
[x:0]
Input-
Synchronous
Data input signals, sampled on the rising edge of K and K clocks during valid write opera-
tions.
CY7C1303BV25 – D
[17:0]
CY7C1306BV25 – D
[35:0]
WPS
Input-
Synchronous
Write Port Select, active LOW.
Sampled on the rising edge of the K clock. When asserted active,
a Write operation is initiated. Deasserting will deselect the Write port. Deselecting the Write port
will cause D
[x:0]
to be ignored.
BWS
0
, BWS
1
,
BWS
2
, BWS
3
Input-
Synchronous
Byte Write Select 0, 1, 2 and 3 - active LOW.
Sampled on the rising edge of the K and K clocks
during Write operations. Used to select which byte is written into the device during the current
portion of the Write operations.
CY7C1303BV25 - BWS
0
controls D
[8:0]
and BWS
1
controls D
[17:9].
CY7C1306BV25 - BWS
0
controls D
[8:0]
, BWS
1
controls D
[17:9]
, BWS
2
controls D
[26:18]
and BWS
3
controls D
[35:27]
Bytes not written remain unaltered. Deselecting a Byte Write Select will cause the corresponding
byte of data to be ignored and not written into the device.
A
Input-
Synchronous
Address Inputs.
Sampled on the rising edge of the K clock during active Read operations and
on the rising edge of K for Write operations. These address inputs are multiplexed for both Read
and Write operations. Internally, the device is organized as 1M x 18 (2 arrays each of 512K x 18)
for CY7C1303BV25 and 512K x 36 (2 arrays each of 256K x 36) for CY7C1306BV25. Therefore,
only 19 address inputs are needed to access the entire memory array of CY7C1303BV25 and
18 address inputs for CY7C1306BV25. These inputs are ignored when the appropriate port is
deselected.
Q
[x:0]
Outputs-
Synchronous
Data Output signals.
These pins drive out the requested data during a Read operation. Valid
data is driven out on the rising edge of both the C and C clocks during Read operations or K and
K when in single clock mode. When the Read port is deselected, Q
[x:0]
are automatically
three-stated.
CY7C1303BV25 - Q
[17:0]
CY7C1306BV25 - Q
[35:0]
RPS
Input-
Synchronous
Read Port Select, active LOW.
Sampled on the rising edge of positive input clock (K). When
active, a Read operation is initiated. Deasserting will cause the Read port to be deselected. When
deselected, the pending access is allowed to complete and the output drivers are automatically
three-stated following the next rising edge of the K clock. Each read access consists of a burst
of two sequential 18-bit or 36-bit transfers.
C
Input-Clock
Positive Input Clock for Output Data
. C is used in conjunction with C to clock out the Read
data from the device. C and C can be used together to deskew the flight times of various devices
on the board back to the controller. See application example for further details.
C
Input-Clock
Negative Input Clock for Output Data
. C is used in conjunction with C to clock out the Read
data from the device. C and C can be used together to deskew the flight times of various devices
on the board back to the controller. See application example for further details.
K
Input-Clock
Positive Input Clock Input.
The rising edge of K is used to capture synchronous inputs to the
device and to drive out data through Q
[x:0]
when in single clock mode. All accesses are initiated
on the rising edge of K.
K
Input-Clock
Negative Input Clock Input.
K is used to capture synchronous inputs to the device and to drive
out data through Q
[x:0]
when in single clock mode.
ZQ
Input
Output Impedance Matching Input.
This input is used to tune the device outputs to the system
data bus impedance. Q
[x:0]
output impedance are set to 0.2 x RQ, where RQ is a resistor
connected between ZQ and ground. Alternately, this pin can be connected directly to V
DDQ
, which
enables the minimum impedance mode. This pin cannot be connected directly to GND or left
unconnected.
TDO
Output
TDO pin for JTAG.
TCK
Input
TCK pin for JTAG.
TDI
Input
TDI pin for JTAG.
TMS
Input
TMS pin for JTAG.
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