PRELIMINARY
CY7C1352B
256K x18 Pipelined SRAM with NoBL™ Architecture
Features
• Pin compatible and functionally equivalent to ZBT™
devices MCM63Z818 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
• 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)
— 7.0 ns (for 80-MHz device)
• 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
• Low standby power
Functional Description
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.
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).
Write operations are controlled by the four Byte Write Select
(BWS
[1:0]
) and a Write Enable (WE) input. All writes are con-
ducted 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 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.
18
Logic Block Diagram
CLK
D
Data-In REG.
CE Q
18
18
CONTROL
and WRITE
LOGIC
18
256Kx18
MEMORY
ARRAY
18
ADV/LD
A
[17:0]
CEN
CE
1
CE2
CE3
WE
BWS [1:0]
Mode
CLK
OUTPUT
REGISTERS
and LOGIC
18
DQ
[15:0]
DP
[1:0]
OE
.
Selection Guide
-166
Maximum Access Time (ns)
Maximum Operating Current (mA)
Shaded areas contain advance information.
NoBL and No Bus Latency are trademarks of Cypress Semiconductor Corporation.
ZBT is a trademark of Integrated Device Technology.
-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
3.5
Commercial
400
5
Maximum CMOS Standby Current (mA) Commercial
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134
•
408-943-2600
May 26, 2000
CYPRESS [ CYPRESS SEMICONDUCTOR ]
