AutoStore鈩?/div>
on Power Down
鈥?Recall to SRAM by Software or Power Restore
鈥?15mA I
CC
at 200ns Cycle Time
鈥?Unlimited Read, Write and Recall Cycles
鈥?1,000,000 Store Cycles to EEPROM
鈥?100 Year Data Retention Over Full Industrial
Temperature Range
鈥?Commercial and Industrial Temp. Ranges
鈥?28 Pin 600 or 300 mil PDIP and 350 mil SOIC
DESCRIPTION
The Simtek STK15C88 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
EEPROM. Data transfers from the SRAM to the
EEPROM (the
STORE
operation) can take place
automatically on power down using charge stored in
system capacitance. Transfers from the EEPROM to
the SRAM (the
RECALL
operation) take place auto-
matically on restoration of power. Initiation of
STORE and RECALL cycles can also be controlled
by entering control sequences on the SRAM inputs.
BLOCK DIAGRAM
EEPROM ARRAY
256 x 1024
A
6
A
7
A
8
A
9
A
11
A
12
A
13
A
14
DQ
0
DQ
1
DQ
2
DQ
3
DQ
4
DQ
5
DQ
6
DQ
7
ROW DECODER
PIN CONFIGURATIONS
A
14
A
12
A
7
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
CC
W
A
13
A
8
A
9
A
11
G
A
10
E
DQ
7
DQ
6
DQ
5
DQ
4
DQ
3
VCC
A
6
A
5
A
4
A
3
STORE
STATIC RAM
ARRAY
256 x 1024
RECALL
STORE/
RECALL
CONTROL
POWER
CONTROL
A
2
A
1
A
0
DQ
0
DQ
1
DQ
2
V
SS
SOFTWARE
DETECT
INPUT BUFFERS
A
0
A
13
COLUMN I/O
COLUMN DEC
28 - 300 PDIP
28 - 600 PDIP
28 - 350 SOIC
28 - 300 SOIC
PIN NAMES
A
0
A
1
A
2
A
3
A
4
A
5
A
10
A
0
- A
14
Address Inputs
Write Enable
Data In/Out
Chip Enable
Output Enable
Power (+5V)
Ground
G
W
DQ
0
- DQ
7
E
W
E
G
V
CC
V
SS
August 1998
5-35