Cypress CY7C1355C 用户手册
9-Mbit (256K x 36/512K x 18)
Flow-Through SRAM with NoBL™ Architecture
CY7C1355C
CY7C1357C
CY7C1357C
Cypress Semiconductor Corporation
•
198 Champion Court
•
San Jose
,
CA 95134-1709
•
408-943-2600
Document #: 38-05539 Rev. *E
Revised September 14, 2006
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
• 3.3V/2.5V I/O power supply (V
DDQ
)
• Fast clock-to-output times
— 6.5 ns (for 133-MHz device)
• Clock Enable (CEN) pin to enable clock and suspend
operation
• Synchronous self-timed writes
• Asynchronous Output Enable
• Available in JEDEC-standard and lead-free 100-Pin
TQFP, lead-free and non lead-free 119-Ball BGA
package and 165-Ball FBGA package
package and 165-Ball FBGA package
• Three chip enables for simple depth expansion.
• Automatic Power-down feature available using ZZ
mode or CE deselect
• IEEE 1149.1 JTAG-Compatible Boundary Scan
• Burst Capability—linear or interleaved burst order
• Low standby power
Functional Description
[1]
The CY7C1355C/CY7C1357C is a 3.3V, 256K x 36/512K 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
CY7C1355C/CY7C1357C is equipped with the advanced No
Bus Latency (NoBL) logic required to enable consecutive
Read/Write operations with data being transferred on every
clock cycle. This feature dramatically improves the throughput
of data through the SRAM, especially in systems that require
frequent Write-Read transitions.
Synchronous Flow-through Burst SRAM designed specifically
to support unlimited true back-to-back Read/Write operations
without the insertion of wait states. The
CY7C1355C/CY7C1357C is equipped with the advanced No
Bus Latency (NoBL) logic required to enable consecutive
Read/Write operations with data being transferred 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).
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
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 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
100 MHz
Unit
Maximum Access Time
6.5
7.5
ns
Maximum Operating Current
250
180
mA
Maximum CMOS Standby Current
40
40
mA
Note:
1. For best-practices recommendations, please refer to the Cypress application note System Design Guidelines on www.cypress.com.