Cypress Semiconductor CY7C1338G Arkusz specyfikacji - Strona 4

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Pin Definitions

(continued)

Name

I/O

ADSP

Input-

Synchronous

ADSC

Input-

Synchronous

Input-

Asynchronous

DQs

I/O-

Synchronous

Power

Supply

Ground

I/O Power

DDQ

Supply

I/O Ground Ground for the I/O circuitry.

SSQ

MODE

Input-

Static

NC/9M,

–

NC/18M

NC/36M

NC/72M,

NC/144M,

NC/288M,

NC/576M,

NC/1G

Functional Overview

All synchronous inputs pass through input registers controlled

by the rising edge of the clock. Maximum access delay from

the clock rise (t

) is 6.5 ns (133-MHz device).

The CY7C1338G supports secondary cache in systems

utilizing either a linear or interleaved burst sequence. The

interleaved burst order supports Pentium and i486™

processors. The linear burst sequence is suited for processors

that utilize a linear burst sequence. The burst order is

user-selectable, and is determined by sampling the MODE

input. Accesses can be initiated with either the Processor

Address Strobe (ADSP) or the Controller Address Strobe

(ADSC). Address advancement through the burst sequence is

controlled by the ADV input. A two-bit on-chip wraparound

burst counter captures the first address in a burst sequence

and automatically increments the address for the rest of the

burst access.

Byte write operations are qualified with the Byte Write Enable

(BWE) and Byte Write Select (BW

Document #: 38-05521 Rev. *D

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

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

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

nized. ASDP is ignored when CE

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

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

into the burst counter. When ADSP and ADSC are both asserted, only ADSP is recognized.

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

condition with data integrity preserved. During normal operation, this pin has to be low or left floating.

ZZ pin has an internal pull-down.

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 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

are placed in a tri-state condition.

Power supply inputs to the core of the device.

Ground for the core of the device.

Power supply for the I/O circuitry.

Selects Burst Order. When tied to GND selects linear burst sequence. When tied to V

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

operation. Mode Pin has an internal pull-up.

No Connects. Not Internally connected to the die.

No Connects. Not internally connected to the die. NC/9M,NC/18M,NC/36M,NC/72M, NC/144M,

NC/288M, NC/576M and NC/1G are address expansion pins that are not internally connected to

the die.

) inputs. A Global Write

[A:D]

Description

is deasserted HIGH

Enable (GW) overrides all byte write inputs and writes data to

all four bytes. All writes are simplified with on-chip

synchronous self-timed write circuitry.

Three synchronous Chip Selects (CE

asynchronous Output Enable (OE) provide for easy bank

selection and output tri-state control. ADSP is ignored if CE

is HIGH.

Single Read Accesses

A single read access is initiated when the following conditions

are satisfied at clock rise: (1) CE

asserted active, and (2) ADSP or ADSC is asserted LOW (if

the access is initiated by ADSC, the write inputs must be

deasserted during this first cycle). The address presented to

the address inputs is latched into the address register and the

burst counter/control logic and presented to the memory core.

If the OE input is asserted LOW, the requested data will be

available at the data outputs a maximum to t

rise. ADSP is ignored if CE

CY7C1338G

[1:0]

are also loaded

[1:0]

or left

, CE

) and an

, CE

, and CE

after clock

CDV

is HIGH.

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