9-Mb (256K x 36/512K x 18) Flow-Through
SRAM with NoBL™ Architecture
• No Bus Latency™ (NoBL™) architecture eliminates
dead cycles between write and read cycles.
• Can support up to 133-MHz bus operations with zero
— Data is transferred on every clock
• Pin compatible and functionally equivalent to ZBT™
• 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
• 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
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
Write operations are controlled by the two or four Byte Write
Select (BWX) and a Write Enable (WE) input. All writes are
conducted with on-chip synchronous self-timed write circuitry.
Three synchronous Chip Enables (CE1, CE2, CE3) 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.
Maximum Access Time
6.5 7.0 7.5
Maximum Operating Current
250 220 180
Maximum CMOS Standby Current 30 30 30
1. For best-practices recommendations, please refer to the Cypress application note System Design Guidelines on www.cypress.com.
Cypress Semiconductor Corporation • 3901 North First Street • San Jose, CA 95134 • 408-943-2600
Document #: 38-05117 Rev. *B
Revised January 27, 2004
DataSheet4 U .com