Pin Definitions, Pin Name Pin Description

CY7C1422BV18, CY7C1429BV18

CY7C1423BV18, CY7C1424BV18

Pin Definitions

Pin Name

Pin Description

D[x:0]

Input-

Data Input Signals. Sampled on the rising edge of K and

clocks during valid write operations.

Synchronous

CY7C1422BV18 - D[7:0]

CY7C1429BV18 - D[8:0]

CY7C1423BV18 - D[17:0]

CY7C1424BV18 - D[35:0]

Input-

Synchronous Load. This input is brought LOW when a bus cycle sequence is defined. This definition

Synchronous

includes address and read/write direction. All transactions operate on a burst of 2 data (one clock period

of bus activity).

Nibble Write Select 0, 1 − Active LOW (CY7C1422BV18 Only). Sampled on the rising edge of the K

NWS

NWS1

and K clocks during Write operations. Used to select which nibble is written into the device during the

current portion of the Write operations.Nibbles not written remain unaltered.

NWS0 controls D[3:0] and NWS1 controls D[7:4].

All Nibble Write Selects are sampled on the same edge as the data. Deselecting a Nibble Write Select

ignores the corresponding nibble of data and it is not written into the device.

Input-

Byte Write Select 0, 1, 2 and 3 − Active LOW. Sampled on the rising edge of the K and

clocks during

BWS

BWS1,

Synchronous

write operations. Used to select which byte is written into the device during the current portion of the write

BWS2,

operations. Bytes not written remain unaltered.

BWS3

CY7C1429BV18 − BWS0

controls D[8:0]

CY7C1423BV18 − BWS0

controls D[8:0],

BWS

1 controls D[17:9]

CY7C1424BV18 − BWS0 controls D[8:0], BWS1 controls D[17:9],BWS2 controls D[26:18] and BWS3 controls

D[35:27].

All the Byte Write Selects are sampled on the same edge as the data. Deselecting a Byte Write Select

ignores the corresponding byte of data and it is not written into the device.

Input-

Address Inputs. Sampled on the rising edge of the K clock during active read and write operations. These

Synchronous

address inputs are multiplexed for both read and write operations. Internally, the device is organized as

4M x 8 (2 arrays each of 2M x 8) for CY7C1422BV18, 4M x 9 (2 arrays each of 2M x 9) for CY7C1429BV18,

2M x 18 (2 arrays each of 1M x 18) for CY7C1423BV18 and 1M x 36 (2 arrays each of 512K x 36) for

CY7C1424BV18. Therefore, only 21 address inputs are needed to access the entire memory array of

CY7C1422BV18 and CY7C1429BV18, 20 address inputs for CY7C1423BV18 and 19 address inputs for

CY7C1424BV18. These inputs are ignored when the appropriate port is deselected.

Q[x:0]

Outputs-

Data Output Signals. These pins drive out the requested data during a read operation. Valid data is

Synchronous

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 tri-stated.

CY7C1422BV18 − Q[7:0]

CY7C1429BV18 − Q[8:0]

CY7C1423BV18 − Q[17:0]

CY7C1424BV18 − Q[35:0]

Input-

Synchronous Read/Write Input. When

is LOW, this input designates the access type (read when

R/W

Synchronous

R/W is HIGH, write when R/W is LOW) for the loaded address. R/W must meet the setup and hold times

around the edge of K.

CInput 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 on page 9 for further details.

CInput 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 on page 9 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.

KInput Clock Negative Input Clock Input. K is used to capture synchronous inputs being presented to the device and to drive out data through Q[x:0] when in single clock mode.

Document #: 001-07035 Rev. *D

Page 6 of 30

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