APPLICATION NOTE
A V A I L A B L E
AN56
X20C05
4K
X20C05
512 x 8
High Speed AUTOSTORE™ NOVRAM
FEATURES
DESCRIPTION
• Fast Access Time: 35ns, 45ns, 55ns
• High Reliability
The Xicor X20C05 is a 512 x 8 NOVRAM featuring a
high-speed static RAM overlaid bit-for-bit with a non-
volatile electrically erasable PROM (E2PROM). The
X20C05 is fabricated with advanced CMOS floating
gate technology to achieve high speed with low power
and wide power-supply margin. The X20C05 features
the JEDEC approved pinout for byte-wide memories,
compatible with industry standard RAMs, ROMs,
EPROMs, and E2PROMs.
—Endurance: 1,000,000 Nonvolatile Store
Operations
—Retention: 100 Years Minimum
• Power-on Recall
—E2PROM Data Automatically Recalled Into
SRAM Upon Power-up
• AUTOSTORE™ NOVRAM
—User Enabled Option
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 5µs or less.
—Automatically Stores SRAM Data Into the
E2PROM Array When VCC Low Threshold is
Detected
—Open Drain AUTOSTORE Status Output Pin
• Software Data Protection
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.
—Locks Out Inadvertent Store Operations
• Low Power CMOS
—Standby: 250µA
• Infinite E2PROM Array Recall, and RAM Read
and Write Cycles
• Upward compatible with X20C16 (16K)
PIN CONFIGURATION
PLASTIC
CERDIP
LCC
PLCC
NE
NC
1
28
27
26
25
24
23
22
21
20
19
18
17
16
15
V
CC
2
WE
AS
4
3
2
1
32 31 30
29
3
4
A
8
A
A
A
A
A
A
A
5
6
7
8
9
A
7
A
6
A
5
A
4
A
3
A
2
A
1
A
0
6
5
4
3
2
1
0
8
5
NC
NC
OE
NC
CE
I/O
28
27
26
25
24
23
22
21
NC
NC
NC
OE
NC
CE
I/O
6
7
X20C05
(TOP VIEW)
X20C05
8
9
10
11
12
13
10
11
12
13
14
7
I/O
I/O
I/O
I/O
NC
I/O
6
5
4
3
7
I/O
I/O
0
1
2
0
6
14 15 16 17 18 19 20
I/O
I/O
3827 FHD F02
3827 FHD F03
AUTOSTORE™ NOVRAM is a trademark of Xicor, Inc.
©Xicor, Inc. 1991 - 1997 Patents Pending
3827-2.7 7/31/97 T4/C0/D0 SH
Characteristics subject to change without notice
1