9-Mb (256K x 36/512K x 18) Flow-Through
SRAM with NoBLTM Architecture
CY7C1355B
CY7C1357B
Cypress Semiconductor Corporation
3901 North First Street
San Jose
,
CA 95134
408-943-2600
Document #: 38-05117 Rev. *B
Revised January 27, 2004
Features
No Bus LatencyTM (NoBLTM) architecture eliminates
dead cycles between write and read cycles.
Can support up to 133-MHz bus operations with zero
wait states
-- Data is transferred on every clock
Pin compatible and functionally equivalent to ZBTTM
devices
Internally self-timed output buffer control to eliminate
the need to use OE
Registered inputs for flow-through operation
Byte Write capability
3.3V/2.5V I/O power supply
Fast clock-to-output times
-- 6.5 ns (for 133-MHz device)
-- 7.0 ns (for 117-MHz device)
-- 7.5 ns (for 100-MHz device)
Clock Enable (CEN) pin to enable clock and suspend
operation
Synchronous self-timed writes
Asynchronous Output Enable
Offered in JEDEC-standard 100 TQFP, 119-Ball BGA and
165-Ball fBGA packages
Three chip enables for simple depth expansion.
Automatic Power-down feature available using ZZ
mode or CE deselect.
JTAG boundary scan for BGA and fBGA packages
Burst Capability--linear or interleaved burst order
Low standby power
Functional Description
[1]
The CY7C1355B/CY7C1357B is a 3.3V, 256K x 36/ 512K x 18
Synchronous Flow-through Burst SRAM designed specifically
to support unlimited true back-to-back Read/Write operations
without the insertion of wait states. The
CY7C1355B/CY7C1357B is equipped with the advanced No
Bus Latency (NoBL) logic required to enable consecutive
Read/Write operations with data being transferred on every
clock cycle. This feature dramatically improves the throughput
of data through the SRAM, especially in systems that require
frequent Write-Read transitions.
All synchronous inputs pass through input registers controlled
by the rising edge of the clock. The clock input is qualified by
the Clock Enable (CEN) signal, which when deasserted
suspends operation and extends the previous clock cycle.
Maximum access delay from the clock rise is 6.5 ns (133-MHz
device).
Write operations are controlled by the two or four Byte Write
Select (BW
X
) and a Write Enable (WE) input. All writes are
conducted with on-chip synchronous self-timed write circuitry.
Three synchronous Chip Enables (CE
1
, CE
2
, CE
3
) and an
asynchronous Output Enable (OE) provide for easy bank
selection and output three-state control. In order to avoid bus
contention, the output drivers are synchronously three-stated
during the data portion of a write sequence.
Selection Guide
133 MHz
117 MHz
100 MHz
Unit
Maximum Access Time
6.5
7.0
7.5
ns
Maximum Operating Current
250
220
180
mA
Maximum CMOS Standby Current
30
30
30
mA
Note:
1. For best-practices recommendations, please refer to the Cypress application note System Design Guidelines on www.cypress.com.
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