STK12C68-IM
STK12C68-IM
CMOS nvSRAM
8K x 8 AutoStore™
Nonvolatile Static RAM
Industrial Temperature/Military Screen
DESCRIPTION
FEATURES
• Industrial Temperature with Military Screening
• 25, 35 and 45ns Access Times
The Simtek STK12C68-IM is a fast static RAM (25, 35
and 45ns), 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
independentnonvolatiledataresidesinEEPROM. 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. Soft-
ware sequences may also be used to initiate both
STORE and RECALL operations. A STORE can also be
initiated via a single pin.
• 15 mA I at 200ns Access Speed
CC
• 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
The STK12C68-IM is available in the following
packages: a 28-pin 300 mil ceramic DIP and a 28-pad
LCC. MIL-STD-883 and Standard Military Drawing
(SMD 5962-94599) devices are also available.
• Commercial and Industrial Temperatures
• Available in multiple standard packages
PIN CONFIGURATIONS
LOGIC BLOCK DIAGRAM
1
VCAP
28
VCCX
2
3
27
26
W
A12
A 7
A 6
A 5
A 4
A 3
HSB
A 8
A 9
A11
G
EEPROM ARRAY
256 x 256
25
24
4
5
3
2
28 27
26
1
4
5
A 6
A 5
HSB
A 8
23
22
6
7
A3
25
24
23
22
21
6
A 4
A 3
A2
A1
A 9
A11
G
STORE
A4
8
9
7
21
20
A 2
A 1
A 0
A 10
8
TOP VIEW
A5
E
DQ 7
RECALL
STATIC RAM
9
A10
10
11
19
18
10
20
19
18
A6
A0
DQ0
DQ1
E
DQ
DQ 6
DQ 5
ARRAY
0
11
12
DQ7
DQ6
17
16
15
12
13
14
DQ
1
A7
A 0
A12
256 x 256
13 14 15 16 17
DQ
DQ
4
2
A8
A9
A
VSS
DQ 3
HSB
STORE/
RECALL
CONTROL
28 - LCC
28 - 300 CDIP
12
DQ0
DQ1
DQ2
DQ3
PIN NAMES
COLUMN I/O
A
- A
Address Inputs
Write Enable
Data In/Out
Chip Enable
Output Enable
Power (+5V)
Ground
0
12
COLUMN DECODER
W
DQ - DQ
0
7
DQ4
DQ5
DQ6
DQ7
E
A0
A1
A2
A
A11
10
G
E
G
V
CCX
V
SS
V
Capacitor
CAP
W
HSB
Hardware Store/Busy
41