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STK15C68 Datasheet, PDF (1/9 Pages) List of Unclassifed Manufacturers – 8K x 8 AutoStore nvSRAM
STK15C68
8K x 8 AutoStore™ nvSRAM
High Performance CMOS
Nonvolatile Static RAM
FEATURES
• Nonvolatile Storage Without Battery Problems
• Directly Replaces 8K x 8 static RAM, Battery
Backed RAM or EEPROM
• 25ns, 35ns and 45ns Access Times
• Store to EEPROM Initiated by Software or
AutoStore™ on Power Down
• Recall to SRAM by Software or Power Restore
• 15mA ICC at 200ns Cycle Time
• Unlimited Read, Write and Recall Cycles
• 1,000,000 Store Cycles to EEPROM
• 100 Year Data Retention Over Full Industrial
Temperature Range
• Commercial and Industrial Temp. Ranges
• 28 Pin 600 or 300 mil PDIP and 350 mil SOIC
DESCRIPTION
The STK15C68 is a fast SRAM with a nonvolatile
EEPROM element incorporated in each static memory
cell. The SRAM can be read and written an unlimited
number of times, while independent, nonvolatile data
resides in EEPROM. Data transfers from the SRAM to
EEPROM (the STORE operation) can take place auto-
matically on power down using charge stored in system
capacitance. Transfers from the EEPROM to the SRAM
(the RECALL operation) take place automatically on res-
toration of power. Initiation of STORE and RECALL
cycles can also be controlled by entering control
sequences on the SRAM inputs. The nvSRAM can be
used in place of existing 8K x 8 SRAMs and also matches
the pinout of 8k x 8 Battery Backed SRAMs, EPROMs,
and EEPROMs, allowing direct substitution while enhanc-
ing performance. There is no limit on the number of read
or write cycles that can be executed and no support cir-
cuitry is required for microprocessor interface.
BLOCK DIAGRAM
PIN CONFIGURATIONS
A5
A6
A7
A8
A9
A11
A12
DQ0
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
DQ7
EEPROM ARRAY
128 x 512
STORE
STATIC RAM
ARRAY
128 x 512
RECALL
COLUMN I/O
COLUMN DEC
A0 A1 A2 A3 A4 A10
STORE/
RECALL
CONTROL
VCC
POWER
CONTROL
SOFTWARE
A0
DETECT
A12
G
E
W
NC 1
A12 2
A7 3
A6 4
A5 5
A4 6
A3 7
A2 8
A1 9
A 0 10
DQ 0 11
DQ 1 12
DQ 2 13
V SS 14
28 VCC
27 W
26 NC
25 A8
24 A9
23 A11
22 G
21 A10
20 E
19 DQ 7
18 DQ 6
17 DQ 5
16 DQ 4
15 DQ 3
28 - 300 PDIP
28 - 600 PDIP
28 - 350 SOIC
PIN NAMES
A0 - A12
W
Address Inputs
Write Enable
DQ0 - DQ7
E
Data In/Out
Chip Enable
G
Output Enable
VCC
Power (+5V)
VSS
Ground
4-61
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