July 1999
5-1
STK11C88
32K x 8 nvSRAM
QuantumTrap™ CMOS
Nonvolatile Static RAM
FEATURES
• 20ns, 25ns, 35ns and 45ns Access Times
• STORE to EEPROM Initiated by Software
• RECALL to SRAM Initiated by Software or
Power Restore
• 10mA Typical I
CC at 200ns Cycle Time
• Unlimited READ, WRITE and RECALL Cycles
• 1,000,000 STORE Cycles to EEPROM
• 100-Year Data Retention in EEPROM
• Commercial and Industrial Temperatures
• 28-Pin PDIP and SOIC Packages
DESCRIPTION
The Simtek STK11C88 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), or from EEPROM to
SRAM
(the RECALL operation), take place using a
software sequence. Transfers from the EEPROM to
the SRAM (the RECALL operation) also take place
automatically on restoration of power.
The STK11C88 is pin-compatible with industry-
standard SRAMs.
BLOCK DIAGRAM
EEPROM ARRAY
512 x 512
STORE
RECALL
COLUMN I/O
COLUMN DEC
STATIC RAM
ARRAY
512 x 512
STORE/
RECALL
CONTROL
A6
A7
A11
A12
A13
A14
DQ0
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
DQ7
SOFTWARE
DETECT
A0 - A13
G
E
W
A9
A8
A10
A3
A2
A0 A1
A4
A5
PIN CONFIGURATIONS
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
VSS
VCC
A13
A8
A9
A11
G
W
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
A10
E
DQ7
DQ6
DQ5
DQ4
DQ3
28 - 300 PDIP
28 - 600 PDIP
28 - 300 SOIC
28 - 350 SOIC
PIN NAMES
A0 - A14
Address Inputs
W
Write Enable
DQ0 - DQ7
Data In/Out
E
Chip Enable
G
Output Enable
VCC
Power (+5V)
VSS
Ground