APPLICATION NOTE
A V A I L A B L E
AN56
X20C16
16K
X20C16
2K x 8 Bit
High Speed AUTOSTORE™ NOVRAM
FEATURES
DESCRIPTION
• Fast Access Time: 35ns, 45ns, 55ns
• High Reliability
TheXicorX20C16isa2Kx8NOVRAMfeaturingahigh-
speed static RAM overlaid bit-for-bit with a nonvolatile
electrically erasable PROM (E2PROM) and the
AUTOSTORE feature which automatically saves the
RAMcontentstoE2PROMatpower-down. TheX20C16
isfabricatedwithadvancedCMOSfloatinggatetechnol-
ogy to achieve high speed with low power and wide
power-supply margin. The X20C16 features a compat-
ible JEDEC approved pinout for byte-wide memories,
for industry standard RAMs, ROMs, EPROMs, and
E2PROMs.
—Endurance: 1,000,000 Nonvolatile Store
Operations
—Retention: 100 Years Minimum
• AUTOSTORE™ NOVRAM
—Automatically Stores RAM Data Into the
E2PROM Array When VCC Low Threshold is
Detected
—User Enabled Option
—Open Drain AUTOSTORE Status Output Pin
• Power-on Recall
The NOVRAM design allows data to be easily trans-
ferred from RAM to E2PROM (store) and E2PROM to
RAM(recall). Thestoreoperationiscompletedin5msor
less and the recall operation is completed in 10µs or
less. An automatic array recall operation reloads the
contents of the E2PROM into RAM upon power-up.
—E2PROM Data Automatically Recalled Into
RAM Upon Power-up
• Software Data Protection
—Locks Out Inadvertent Store Operations
• Low Power CMOS
—Standby: 250µA
• Infinite E2PROM Array Recall, and RAM Read
and Write Cycles
Xicor NOVRAMS are designed for unlimited write
operations to RAM, either from the host or recalls from
E2PROM, andaminimum1,000,000storeoperationsto
the E2PROM. Data retention is specified to be greater
than 100 years.
PIN CONFIGURATION
PLASTIC
CERDIP
TSOP
NE
NC
1
28
27
26
25
24
23
22
21
20
19
18
17
16
15
V
CC
2
WE
A
7
A
6
A
5
A
4
A
3
A
2
A
1
A
0
3
AS
4
A
8
A
9
LCC
5
PLCC
SOIC
6
NC
7
OE
1
28
27
26
25
24
23
22
21
20
19
18
17
16
15
NC
OE
A
10
CE
X20C16
8
A
X20C16
10
2
4
3
2
1
32 31 30
29
9
CE
3
A
9
I/O
7
A
A
A
A
A
A
A
5
6
7
8
9
A
A
10
11
12
13
14
I/O
7
I/O
6
I/O
5
I/O
4
6
5
4
3
2
1
0
8
9
4
A
I/O
I/O
I/O
I/O
V
8
6
5
4
3
28
27
26
25
24
23
22
21
I/O
0
1
2
5
AS
NC
NC
OE
A
I/O
I/O
V
6
WE
7
X20C16
(TOP VIEW)
V
CC
NE
X20C16
I/O
3
SS
8
SS
10
11
12
13
10
3826 FHD F02
9
NC
I/O
2
1
0
CE
I/O
10
11
12
13
14
A
7
I/O
I/O
NC
7
A
3826 ILL F17.2
6
I/O
I/O
0
6
A
5
A
0
14 15 16 17 18 19 20
A
A
4
1
3826 FHD F15.1
A
3
A
2
3826 FHD F03
AUTOSTORE™ NOVRAM is a trademark of Xicor, Inc.
©Xicor, Inc. 1991, 1995, 1996 Patents Pending
3826-2.9 2/24/99 T4/C0/D0 SH
Characteristics subject to change without notice
1
XICOR [ XICOR INC. ]
