Cypress CY7C1223H manual Pin Descriptions

CY7C1223H

Pin Descriptions

Pin

Type

Description

A0, A1, A

Input-

Address Inputs used to select one of the 128K address locations

.

Sampled at the rising

Synchronous

edge of the CLK if ADSP or ADSC is active LOW, and CE1, CE2, and CE3 are sampled active.

A[1:0] are fed to the two-bit counter.

[A:B]

Input-

Byte Write Select Inputs, active LOW. Qualified with

to conduct byte writes to the SRAM.

BW

BWE

Synchronous

Sampled on the rising edge of CLK.

Input-

Global Write Enable Input, active LOW. When asserted LOW on the rising edge of CLK, a

GW

Synchronous

global write is conducted (ALL bytes are written, regardless of the values on BW[A:B] and BWE).

Input-

Byte Write Enable Input, active LOW. Sampled on the rising edge of CLK. This signal must

BWE

Synchronous

be asserted LOW to conduct a byte write.

CLK

Input-

Clock Input. Used to capture all synchronous inputs to the device. Also used to increment the

Clock

burst counter when ADV is asserted LOW, during a burst operation.

1

Input-

Chip Enable

1

Input, active LOW. Sampled on the rising edge of CLK. Used in conjunction

CE

Synchronous

with CE2 and CE3 to select/deselect the device. ADSP is ignored if CE1 is HIGH. CE1 is sampled

only when a new external address is loaded.

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/deselect the device. CE2 is sampled only when a new external

address is loaded.

3

Input-

Chip Enable 3 Input, active LOW. Sampled on

the

rising edge of CLK. Used in conjunction

CE

Synchronous

with CE1 and CE2 to select/deselect the device. CE3 is sampled only when a new external

address is loaded

Input-

Output Enable, asynchronous input, active LOW. Controls the direction of the I/O pins. When

OE

Asynchronous

LOW, the I/O pins behave as outputs. When deasserted HIGH, I/O pins are tri-stated, and act

as input data pins. OE is masked during the first clock of a read cycle when emerging from a

deselected state.

Input-

Advance Input signal, sampled on the rising edge of CLK, active LOW. When asserted, it

ADV

Synchronous

automatically increments the address in a burst cycle.

Input-

Address Strobe from Processor, sampled on the rising edge of CLK, active LOW. When

ADSP

Synchronous

asserted LOW, addresses presented to the device are captured in the address registers.

A[1:0]

are also loaded into the burst counter. When ADSP and ADSC are both asserted, only ADSP

is recognized. ASDP is ignored when CE1 is deasserted HIGH.

Input-

Address Strobe from Controller, sampled on the rising edge of CLK, active LOW. When

ADSC

Synchronous

asserted LOW, addresses presented to the device are captured in the address registers.

A[1:0]

are also loaded into the burst counter. When ADSP and ADSC are both asserted, only ADSP

is recognized.

ZZ

Input-

ZZ “sleep” Input, active HIGH. When asserted HIGH places the device in a non-time-critical

Asynchronous

“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.

DQs

I/O-

Bidirectional Data I/O lines. As inputs, they feed into an on-chip data register that is triggered

DQP[A:B]

Synchronous

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 DQP[A:B] are placed in a tri-state condition.

VDD

Power Supply

Power supply inputs to the core of the device.

VSS

Ground

Ground for the core of the device.

VDDQ

I/O Power

Power supply for the I/O circuitry.

Supply

VSSQ

I/O Ground

Ground for the I/O circuitry.

MODE

Input-

Selects Burst Order. When tied to GND selects linear burst sequence. When tied to VDD or left

Static

floating selects interleaved burst sequence. This is a strap pin and should remain static during

device operation. Mode Pin has an internal pull-up.

NC

No Connects. Not internally connected to the die. 4M, 9M, 18M, 72M, 144M, 288M, 576M, and

1G are address expansion pins and are not internally connected to the die.

Document #: 38-05674 Rev. *B

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