鈥?/div>
RECALL
to SRAM Initiated by Software or
Power Restore
鈥?10mA Typical I
CC
at 200ns Cycle Time
鈥?Unlimited READ, WRITE and
RECALL
Cycles
鈥?100,000
STORE
Cycles to EEPROM
鈥?10-Year Data Retention in EEPROM
鈥?Single 5V + 10% Operation
鈥?Not Sensitive to Power On/Off Ramp Rates
鈥?No Data Loss from Undershoot
鈥?32-Pad LCC and 32-Pin 300 mil CDIP Packages
DESCRIPTION
The Simtek STK14C88-M 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 auto-
matically on power down. A 68碌F or larger capacitor
tied from V
CAP
to ground guarantees the
STORE
operation, regardless of power-down slew rate or
loss of power from 鈥渉ot swapping鈥? Transfers from
the
EEPROM
to the
SRAM
(the
RECALL
operation)
take place automatically on restoration of power. Ini-
tiation of
STORE
and
RECALL
cycles can also be
software controlled by entering speci鏗乧 read
sequences. A hardware
STORE
may be initiated with
the HSB pin.
BLOCK DIAGRAM
V
CCX
EEPROM ARRAY
512 x 512
V
CAP
PIN CONFIGURATIONS
V
CCX
HSB
A
14
V
CAP
A
7
A
12
A
12
A
7
3
4
30
29
W
A
13
A
8
A
9
A
11
G
NC
A
10
E
DQ
7
DQ
6
DQ
5
DQ
4
DQ
3
4
3
2
32 31 30
29
28
27
A
5
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
32 300 mil DIP
POWER
CONTROL
A
6
A
5
A
4
A
3
NC
A
2
5
6
7
8
9
10
11
12
13
14
15
16
28
27
26
25
24
23
22
21
20
19
18
17
A
6
5
6
7
8
9
10
11
12
0
1
W
A
13
V
CAP
A
14
1
2
32
31
V
CCX
HSB
A
5
A
4
A
8
A
9
ROW DECODER
STORE
STATIC RAM
ARRAY
512 x 512
RECALL
STORE/
RECALL
CONTROL
HSB
A
1
A
0
DQ
0
DQ
1
DQ
2
V
SS
A
3
NC
A
2
A
1
32
LCC
26
25
24
23
22
A
11
G
NC
A
E
DQ
10
A
0
DQ
13
21
14 15 16 17 18 19 20
7
DQ
1
DQ
2
V
SS
3
DQ
4
DQ
5
DQ
INPUT BUFFERS
COLUMN I/O
COLUMN DEC
SOFTWARE
DETECT
A
0
- A
13
PIN NAMES
A
0
- A
14
DQ
0
-DQ
7
E
W
Address Inputs
Data In/Out
Chip Enable
Write Enable
Output Enable
Hardware Store Busy (I/O)
Power (+ 5V)
Capacitor
Ground
A
0
A
1
A
2
A
3
A
4
A
10
G
E
W
G
HSB
V
CCX
V
CAP
V
SS
April 1999
5-43
DQ
6