Cypress CY14B256L - Manual

CY14B256L
256 Kbit (32K x 8) nvSRAM
Cypress Semiconductor Corporation • 198 Champion Court • San Jose , CA 95134-1709 • 408-943-2600
Document Number: 001-06422 Rev. *H Revised January 30, 2009
Features
■ 25 ns, 35 ns, and 45 ns access times
■ Pin compatible with STK14D88
■ Hands off automatic STORE on power down with only a small
capacitor
■ STORE to QuantumTrap™ nonvolatile elements is initiated by
software, hardware, or AutoStore™ on power down
■ RECALL to SRAM initiated by software or power up
■ Unlimited READ, WRITE, and RECALL cycles
■ 200,000 STORE cycles to QuantumTrap
■ 20 year data retention at 55
°C
■ Single 3V +20%, –10% operation
■ Commercial and industrial temperature
■ 32-pin (300 mil) SOIC and 48-pin (300 mil) SSOP packages
■ RoHS compliance
Functional Description
The Cypress CY14B256L is a fast static RAM with a nonvolatile
element in each memory cell. The embedded nonvolatile
elements incorporate QuantumTrap technology producing the
world’s most reliable nonvolatile memory. The SRAM provides
unlimited read and write cycles, while independent, nonvolatile
data resides in the highly reliable QuantumTrap cell. Data
transfers from the SRAM to the nonvolatile elements (the
STORE operation) takes place automatically at power down. On
power up, data is restored to the SRAM (the RECALL operation)
from the nonvolatile memory. Both the STORE and RECALL
operations are also available under software control. A hardware
STORE is initiated with the HSB pin.
STORE/
RECALL
CONTROL
POWER
CONTROL
SOFTWARE
DETECT
STATIC RAM
ARRAY
512 X 512
Quantum Trap
512 X 512
STORE
RECALL
COLUMN I/O
COLUMN DEC
ROW DECODER
INPUT
BUFFERS
OE
CE
WE
HSB
V
CC
V
CAP
A
13
-
A
0
A
0
A
1
A
2
A
3
A
4
A
10
A
5
A
6
A
7
A
8
A
9
A
11
A
12
A
13
A
14
DQ
0
DQ
1
DQ
2
DQ
3
DQ
4
DQ
5
DQ
6
DQ
7
Logic Block Diagram
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