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30, 35 and 45ns Access Times
15, 20 and 25ns Output Enable Access
Unlimited Read and Write to
SRAM
Hardware
STORE
Initiation
Automatic
STORE
Timing
10
5
STORE
cycles to
EEPROM
10 year data retention in
EEPROM
Automatic
RECALL
on Power Up
Hardware
RECALL
Initiation
Unlimited
RECALL
cycles from
EEPROM
Single 5V鹵10% Operation
Commercial and Industrial Temperatures
Available in 600 mil PDIP package
DESCRIPTION
The Simtek STK20C04 is a fast static
RAM
(30, 35,
45ns), with a nonvolatile electrically-erasable
PROM
(
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 may easily be transferred
from the
SRAM
to the
EEPROM
(
STORE
), or from the
EEPROM
to the
SRAM
(
RECALL
) using the NE pin. It
combines the high performance and ease of use of a
fast
SRAM
with nonvolatile data integrity.
The STK20C04 features the industry standard pinout
for nonvolatile
RAM
s in a 28-pin 600 mil plastic DIP.
LOGIC BLOCK DIAGRAM
EEPROM ARRAY
64 X 64
STORE
ROW DECODER
PIN CONFIGURATIONS
NE
NC
A
7
A
6
5
4
3
2
1
0
0
1
2
14
15
6
7
8
9
10
11
12
13
23
22
21
20
19
18
17
16
1
2
3
4
5
28
27
26
25
24
V
CC
W
NC
A
8
A
3
A
4
A
5
A
6
A
7
A
8
STATIC RAM
ARRAY
64 X 64
RECALL
A
A
A
A
A
A
DQ
DQ
DO
NC
NC
G
NC
E
DQ
7
DQ
6
DQ
5
DQ
4
DQ
3
V
SS
28 - 600 PDIP
DQ
0
DQ
1
DQ
2
DQ
3
DQ
4
DQ
5
DQ
6
DQ
7
E
W
INPUT BUFFERS
COLUMN I/O
STORE/
RECALL
CONTROL
COLUMN DECODER
PIN NAMES
A
0
- A
8
W
DQ
0
- DQ
7
G
NE
Address Inputs
Write Enable
Data In/Out
Chip Enable
Output Enable
Nonvolatile Enable
Power (+5V)
Ground
A
0
A
1
A
2
E
G
NE
V
CC
V
SS
2-39