STK20C04
512 x 8 nvSRAM
QuantumTrap™ CMOS
Nonvolatile Static RAM
Obsolete - Not Recommend for new Designs
FEATURES
DESCRIPTION
• 25ns, 35ns and 45ns Access Times
• STORE to Nonvolatile Elements Initiated by
Hardware
• RECALL to SRAM Initiated by Hardware or
Power Restore
• Automatic STORE Timing
• 10mA Typical ICC at 200ns Cycle Time
• Unlimited READ, WRITE and RECALL Cycles
• 1,000,000 STORE Cycles to Nonvolatile Elements
• 100-Year Data Retention over Full Industrial
Temperature Range
• Commercial and Industrial Temperatures
The Simtek STK20C04 is a fast static RAM with a nonvolatile 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 nonvolatile elements. Data may easily be
transferred from the SRAM to the Nonvolatile Elements
(the STORE operation), or from the Nonvolatile Elements to the SRAM (the RECALL operation), using the
NE pin. Transfers from the Nonvolatile Elements to the
SRAM (the RECALL operation) also take place automatically on restoration of power. The STK20C04
combines the high performance and ease of use of a
fast SRAM with nonvolatile data integrity.
The STK20C04 features industry-standard pinout for
nonvolatile RAMs in a 28-pin 600 mil plastic DIP.
PIN CONFIGURATIONS
BLOCK DIAGRAM
NE
NC
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
VSS
A6
A7
A8
DQ0
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
DQ7
INPUT BUFFERS
A5
ROW DECODER
Quantum Trap
16 x 256
STORE
STATIC RAM
ARRAY
16 x 256
RECALL
1
28
2
27
3
26
4
25
5
24
6
23
7
22
8
21
9
20
10
19
11
18
12
17
13
16
14
15
VCC
W
NC
A8
NC
NC
G
NC
E
DQ7
DQ6
DQ5
DQ4
DQ3
28 - 600 PDIP
PIN NAMES
COLUMN I/O
STORE/
RECALL
CONTROL
W
March 2006
1
Write Enable
Data In/Out
Chip Enable
G
Output Enable
Nonvolatile Enable
VCC
Power (+ 5V)
VSS
E
W
NE
G
NE
Address Inputs
E
A0 A1 A2 A3 A4
A0 - A8
DQ0 - DQ7
COLUMN DEC
Ground
Document Control # ML0001 rev 0.2