Cypress CY7C1474V33 用户手册

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页码 29
 
72-Mbit (2M x 36/4M x 18/1M x 72)
 Pipelined SRAM with NoBL™ Architecture
CY7C1470V33
CY7C1472V33
CY7C1474V33
Cypress Semiconductor Corporation
198 Champion Court
San Jose
,
CA 95134-1709
408-943-2600
Document #: 38-05289 Rev. *I
 Revised June 20, 2006
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 3.3V power supply
• 3.3V/2.5V I/O power supply
• Fast clock-to-output time
— 3.0 ns (for 250-MHz device)
• Clock Enable (CEN) pin to suspend operation
• Synchronous self-timed writes
• CY7C1470V33, CY7C1472V33 available in 
JEDEC-standard lead-free 100-pin TQFP, lead-free and 
non-lead-free 165-ball FBGA package. CY7C1474V33 
available in lead-free and non-lead-free 209 ball FBGA 
package
• IEEE 1149.1 JTAG Boundary Scan compatible
• Burst capability—linear or interleaved burst order
• “ZZ” Sleep Mode option and Stop Clock option
Functional Description
The CY7C1470V33, CY7C1472V33, and CY7C1474V33 are
3.3V, 2M x 36/4M x 18/1M x 72 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
CY7C1470V33, CY7C1472V33, and CY7C1474V33 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 CY7C1470V33, CY7C1472V33,
and CY7C1474V33 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
(BW
a
–BW
h
 for CY7C1474V33, BW
a
–BW
d
 for CY7C1470V33
and BW
a
–BW
b
 for CY7C1472V33) 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.
Logic Block Diagram-CY7C1470V33 (2M x 36)
A0, A1, A
C
MODE
BW
a
BW
b
WE
CE1
CE2
CE3
OE
READ LOGIC
DQs
DQP
a
DQP
b
DQP
c
DQP
d
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
BW
c
BW
d
ZZ
SLEEP 
CONTROL
O
U
T
P
U
T
R
E
G
I
S
T
E
R
S