STK12C68-M
4-53
STK12C68-M
CMOS nvSRAM
8K x 8 AutoStore™
Nonvolatile Static RAM
MIL-STD-883 / SMD # 5962-94599
PIN CONFIGURATIONSLOGIC BLOCK DIAGRAM
A
A
A
A
A
A
4
5
6
7
8
EEPROM ARRAY
256 x 256
STORE
RECALL
STATIC RAM
ARRAY
256 x 256
ROW DECODER
STORE/
RECALL
CONTROL
AAAAA
0
1210
12
DQ
DQ
DQ
DQ
DQ
DQ
DQ
DQ
0
1
2
3
4
5
6
7
G
E
W
COLUMN I/O
COLUMN DECODER
INPUT BUFFERS
AA
01
A
3
A
9
12
HSB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
V
A
A
A
A
A
A
A
A
DQ
DQ
DQ
DQ
DQ
DQ
DQ
DQ
V
V
W
HSB
A
A
A
G
A
E
SS
7
6
5
4
3
2
1
0
0
1
2
8
9
10
7
6
5
4
3
CAP
A
12
11
CCX
28 - LCC 28 - 300 C-DIP
PIN NAMES
A
0
- A
12
Address Inputs
W Write Enable
DQ
0
- DQ
7
Data In/Out
E Chip Enable
G Output Enable
V
CCX
Power (+5V)
V
SS
Ground
V
CAP
Capacitor
HSB
Hardware Store/Busy
FEATURES
• 40, 45 and 55ns Access Times
• 15 mA I
CC
at 200ns Access Speed
• Automatic STORE to EEPROM on Power Down
• Hardware or Software initiated STORE to
EEPROM
• Automatic STORE Timing
• 100,000 STORE cycles to EEPROM
• 10 year data retention in EEPROM
• Automatic RECALL on Power Up
• Software initiated RECALL from EEPROM
• Unlimited RECALL cycles from EEPROM
• Single 5V±10% Operation
• Available in multiple standard packages
A
A
A
A
A
A
A
A
A
A
AA
DQ
DQDQ DQ DQ
DQ
DQ
G
A
E
DQ
Vss
V W
HSB
7 12
6
5
4
3
2
1
0
0
1
8
9
11
10
7
6
2 3 4 5
TOP VIEW
4
5
6
7
8
9
10
11
12
32
1
28 27
26
25
24
23
22
21
20
19
18
1716151413
V
CAP CCX
DESCRIPTION
The Simtek STK12C68-M is a fast static RAM (40, 45
and 55ns), with a nonvolatile EEPROM element incor-
porated 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 the EEPROM (the
STORE operation) take place automatically upon power
down using charge stored in an external 100 µF
capacitor. Transfers from the EEPROM to the SRAM
(the RECALL operation) take place automatically on
power up. Software sequences may also be used to
initiate both STORE and RECALL operations. A
STORE can also be initiated via a single pin.
The STK12C68-M is available in the following pack-
ages: a 28-pin 300 mil ceramic DIP and 28-pad LCC.