PRELIMINARY
36-Mbit (1M x 36/2M x 18/512K x 72) Pipelined
SRAM with NoBL™ Architecture
CY7C1462AV25
CY7C1464AV25
CY7C1460AV25
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
, CA 95134
•
408-943-2600
Document #: 38-05354 Rev. *A
Revised December 14, 2004
Features
• Pin-compatible and functionally equivalent to ZBT™
• Supports 250-MHz bus operations with zero wait states
— Available speed grades are 250, 200 and 167 MHz
• Internally self-timed output buffer control to eliminate
the need to use asynchronous OE
• Fully registered (inputs and outputs) for pipelined
operation
• Byte Write capability
• Single 2.5V power supply
• 2.5V/1.8V I/O operation
• Fast clock-to-output times
— 2.6 ns (for 250-MHz device)
— 3.2 ns (for 200-MHz device)
— 3.4 ns (for 167-MHz device)
• Clock Enable (CEN) pin to suspend operation
• Synchronous self-timed writes
• CY7C1460AV25 and CY7C1462AV25 available in
lead-free 100 TQFP and 165 fBGA packages
CY7C1464AV25 available in 209-Ball fBGA package
• IEEE 1149.1 JTAG Boundary Scan
• Burst capability—linear or interleaved burst order
• “ZZ” Sleep Mode option and Stop Clock option
Functional Description
The CY7C1460AV25/CY7C1462AV25/CY7C1464AV25 are
2.5V, 1-Mbit x 36/2-Mbit x 18/Synchronous pipelined burst
SRAMs with No Bus Latency™ (NoBL
™) logic, respectively.
They are designed to support unlimited true back-to-back
Read/Write
operations
with
no
wait
states.
The
CY7C1460AV25/CY7C1462AV25/CY7C1464AV25
are
equipped with the advanced (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 in systems that require frequent
Write/Read transitions. The CY7C1460AV25/ CY7C1462AV25/
CY7C1464AV25 are pin-compatible and functionally equiv-
alent to ZBT devices.
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
previous clock cycle. Write operations are controlled by the
Byte
Write
Selects
(BWa–BWh
for
CY7C1464AV25,
BWa–BWd
for
CY7C1460AV25
and
BWa–BWb
for
CY7C1462AV25) 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.
A0, A1, A
C
MODE
BWa
BWb
WE
CE1
CE2
CE3
OE
READ LOGIC
DQs
DQPa
DQPb
DQPc
DQPd
D
A
T
A
S
T
E
E
R
I
N
G
O
U
T
P
U
T
B
U
F
F
E
R
S
MEMORY
ARRAY
E
E
INPUT
REGISTER 0
ADDRESS
REGISTER 0
WRITE ADDRESS
REGISTER 1
WRITE ADDRESS
REGISTER 2
WRITE REGISTRY
AND DATA COHERENCY
CONTROL LOGIC
BURST
LOGIC
A0'
A1'
D1
D0
Q1
Q0
A0
A1
C
ADV/LD
ADV/LD
E
INPUT
REGISTER 1
S
E
N
S
E
A
M
P
S
E
CLK
CEN
WRITE
DRIVERS
BWc
BWd
ZZ
SLEEP
CONTROL
O
U
T
P
U
T
R
E
G
I
S
T
E
R
S
Logic Block Diagram–CY7C1460AV25 (1 Mbit x 36)