PRELIMINARY
CY7C1352B
256K x18 Pipelined SRAM with NoBL™ Architecture
• Low standby power
Features
Functional Description
• Pin compatible and functionally equivalent to ZBT™
devices MCM63Z818 and MT55L256L18P
The CY7C1352B is a 3.3V 256K by 18 synchronous-pipelined
Burst SRAM designed specifically to support unlimited true
back-to-back Read/Write operations without the insertion of
wait states. The CY7C1352B is equipped with the advanced
No Bus Latency™ (NoBL™) logic required to enable consec-
utive Read/Write operations with data being transferred on ev-
ery clock cycle. This feature dramatically improves the
throughput of the SRAM, especially in systems that require
frequent Read/Write transitions. The CY7C1352B is pin/func-
tionally compatible to ZBT SRAMs MCM63Z819 and
MT55L256L18P.
• Supports 166-MHz bus operations with zero wait states
— Data is transferred on every clock
• Internally self-timed output buffer control to eliminate
the need to use OE
• Fully registered (inputs and outputs) for pipelined
operation
• Byte Write Capability
• 256K x 18 common I/O architecture
• Single 3.3V power supply
All synchronous inputs pass through input registers controlled
by the rising edge of the clock. All data outputs pass through
output 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 previ-
ous clock cycle. Maximum access delay from the clock rise is
3.5 ns (166-MHz device).
• Fast clock-to-output times
— 3.5 ns (for 166-MHz device)
— 3.8 ns (for 150-MHz device)
— 4.0 ns (for 143-MHz device)
— 4.2 ns (for 133-MHz device)
— 5.0 ns (for 100-MHz device)
Write operations are controlled by the four Byte Write Select
— 7.0 ns (for 80-MHz device)
(BWS
) and a Write Enable (WE) input. All writes are con-
[1:0]
• Clock Enable (CEN) pin to suspend operation
• Synchronous self-timed writes
• Asynchronous output enable
• JEDEC-standard 100-pin TQFP package
• Burst Capability—linear or interleaved burst order
ducted with on-chip synchronous self-timed write circuitry.
Three synchronous Chip Enables (CE , CE , CE ) and an
1
2
3
asynchronous Output Enable (OE) provide for easy bank se-
lection 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.
Logic Block Diagram
18
D
CLK
Data-In REG.
CE
Q
18
ADV/LD
18
A[17:0]
CEN
CE
CONTROL
and WRITE
LOGIC
18
256Kx18
1
CE
MEMORY
2
DQ[15:0]
DP[1:0]
CE
ARRAY
18
18
3
WE
BWS
[1:0]
Mode
OE
.
Selection Guide
-166
3.5
400
5
-150
3.8
375
5
-143
4.0
350
5
-133
4.2
300
5
-100
5.0
250
5
-80
7.0
200
5
Maximum Access Time (ns)
Maximum Operating Current (mA)
Commercial
Maximum CMOS Standby Current (mA) Commercial
Shaded areas contain advance information.
NoBL and No Bus Latency are trademarks of Cypress Semiconductor Corporation.
ZBT is a trademark of Integrated Device Technology.
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134
•
408-943-2600
May 26, 2000