PRELIMINARY
CY7C1371DV25
CY7C1373DV25
18-Mbit (512K x 36/1M x 18) Flow-Through
SRAM with NoBL™ Architecture
Features
•
No Bus Latency (NoBL) 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 ZBT™
devices
• Internally self-timed output buffer control to eliminate
the need to use OE
• Registered inputs for flow-through operation
• Byte Write capability
• Single 2.5V power supply
• 2.5V I/O power supply
• Fast clock-to-output times
— 6.5 ns (for 133-MHz device)
— 7.5 ns (for 117-MHz device)
— 8.5 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 CY7C1371DV25/CY7C1373DV25 is a 2.5V, 512K x 36/
1M 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
CY7C1371DV25/CY7C1373DV25 is equipped with the
advanced No Bus Latency (NoBL) logic required to enable
consecutive Read/Write operations with data being trans-
ferred 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 tri-state control. In order to avoid bus
contention, the output drivers are synchronously tri-stated
during the data portion of a write sequence.
Selection Guide
133 MHz
Maximum Access Time
Maximum Operating Current
Maximum CMOS Standby Current
6.5
210
70
117 MHz
7.5
190
70
100 MHz
8.5
175
70
Unit
ns
mA
mA
Notes:
1. For best-practices recommendations, please refer to the Cypress application note
System Design Guidelines
on www.cypress.com.
Cypress Semiconductor Corporation
Document #: 38-05557 Rev. **
•
3901 North First Street
•
San Jose
,
CA 95134
•
408-943-2600
Revised August 12, 2004
京公网安备 11010802033920号
EEWORLD
