STK11C68
8K x 8 nvSRAM
QuantumTrap™ CMOS
Nonvolatile Static RAM
FEATURES
DESCRIPTION
• 20ns, 25ns, 35ns and 45ns Access Times
The Simtek STK11C68 is a fast static RAM with a
nonvolatile, electrically erasable PROM 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
the EEPROM. Data transfers from the SRAM to the
EEPROM (the STORE operation), or from EEPROM to
SRAM (the RECALL operation), take place using a
software sequence. Transfers from the EEPROM to
the SRAM (the RECALL operation) also take place
automatically on restoration of power.
• STORE to EEPROM Initiated by Software
• RECALL to SRAM Initiated by Software or
Power Restore
• 10mA Typical 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 Temperatures
• 28-Pin DIP and SOIC Packages
The STK11C68 is pin-compatible with industry-
standard SRAMs. MIL-STD-883 device is also
available (STK11C68-M).
BLOCK DIAGRAM
PIN CONFIGURATIONS
1
NC
28
27
26
25
24
23
22
21
20
19
18
17
16
15
V
CC
W
NC
EEPROM ARRAY
128 x 512
2
A
12
3
A
7
6
5
4
3
A
A
A
5
4
A
A
8
5
A
A
A
A
A
9
STORE
6
STORE/
RECALL
CONTROL
6
A
11
7
G
A
7
STATIC RAM
ARRAY
8
RECALL
2
10
A
8
9
A
E
1
0
128 x 512
10
11
12
13
14
A
A
A
A
DQ
9
7
6
5
DQ
DQ
DQ
0
28 - 300 PDIP
28 - 300 CDIP
28 - 350 SOIC
11
12
DQ
DQ
1
DQ
DQ
2
4
3
SOFTWARE
DETECT
A
- A
12
0
V
SS
DQ
DQ
DQ
0
1
2
COLUMN I/O
PIN NAMES
COLUMN DEC
DQ
DQ
DQ
DQ
DQ
A
- A
Address Inputs
Write Enable
Data In/Out
Chip Enable
Output Enable
Power (+ 5V)
Ground
3
4
0
12
W
5
6
7
A
A A
A A
A
1 4
2 3
10
0
G
DQ - DQ
0
7
E
E
G
W
V
CC
SS
V
June 1999
4-21