Cypress CY7C1472BV33, CY7C1474BV33, CY7C1470BV33 Pin Definitions Pin Name IO Type Pin Description

CY7C1470BV33

CY7C1472BV33, CY7C1474BV33

Table 1. Pin Definitions

Pin Name

IO Type

Pin Description

A0

Input-

Address Inputs Used to Select One of the Address Locations. Sampled at the rising edge

A1

Synchronous

of the CLK.

A

a

Input-

Byte Write Select Inputs, Active LOW. Qualified with

to conduct writes to the SRAM.

BW

WE

BWb

Synchronous

Sampled on the rising edge of CLK. BWa controls DQa and DQPa, BWb controls DQb and DQPb,

BWc

BWc controls DQc and DQPc, BWd controls DQd and DQPd, BWe controls DQe and DQPe, BWf

BWd

controls DQf and DQPf, BWg controls DQg and DQPg, BWh controls DQh and DQPh.

BWe

BWf

BWg

BWh

Input-

Write Enable Input, Active LOW. Sampled on the rising edge of CLK if

is active LOW. This

WE

CEN

Synchronous

signal must be asserted LOW to initiate a write sequence.

Input-

Advance/Load Input Used to Advance the On-chip Address Counter or Load a New

ADV/LD

Synchronous

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

must be driven LOW to load a new address.

CLK

Input-

Clock Input. Used to capture all synchronous inputs to the device. CLK is qualified with

CEN.

Clock

CLK is only recognized if CEN is active LOW.

1

Input-

Chip Enable 1 Input, Active LOW. Sampled on the rising edge of CLK. Used in conjunction with

CE

Synchronous

CE2 and CE3 to select or deselect the device.

CE2

Input-

Chip Enable 2 Input, Active HIGH. Sampled on the rising edge of CLK. Used in conjunction

Synchronous

with CE1 and CE3 to select or deselect the device.

3

Input-

Chip Enable 3 Input, Active LOW. Sampled on the rising edge of CLK. Used in conjunction with

CE

Synchronous

CE1 and CE2 to select or deselect the device.

Input-

Output Enable, Active LOW. Combined with the synchronous logic block inside the device to

OE

Asynchronous

control the direction of the IO pins. When LOW, the IO pins are enabled to behave as outputs.

When deasserted HIGH, IO 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.

Input-

Clock Enable Input, Active LOW. When asserted LOW the clock signal is recognized by the

CEN

Synchronous

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.

DQS

IO-

Bidirectional Data IO Lines. As inputs, they feed into an on-chip data register that is triggered

Synchronous

by the rising edge of CLK. As outputs, they deliver the data contained in the memory location

specified by A[17:0]

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, DQa–DQdare placed in a tri-state condition. The outputs are automat-

ically 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

IO-

Bidirectional Data Parity IO Lines. Functionally, these signals

are

identical to DQX. During write

Synchronous

sequences, DQPa is controlled by BWa, DQPb is controlled by BWb, DQPc is controlled by BWc,

and DQPd is controlled by BWd, DQPe is controlled by BWe, DQPf is controlled by BWf, DQPg

is controlled by BWg, DQPh is controlled by BWh.

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 must not change states during operation. When

left floating MODE defaults HIGH, to an interleaved burst order.

TDO

JTAG Serial

Serial Data Out to the JTAG Circuit. Delivers data on the negative edge of TCK.

Output

Synchronous

TDI

JTAG Serial Input

Serial Data In to the JTAG Circuit. Sampled on the rising edge of TCK.

Synchronous

Document #: 001-15031 Rev. *C

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