APPLICATION NOTE
A V A I L A B L E
AN56
X20C17
16K
X20C17
2K x 8 Bit
High Speed AUTOSTORE™ NOVRAM
FEATURES
DESCRIPTION
• 24-Pin Standard SRAM DIP Pinout
• Fast Access Time: 35ns, 45ns, 55ns
• High Reliability
TheXicorX20C17isa2Kx8NOVRAMfeaturingahigh-
speed static RAM overlaid bit-for-bit with a nonvolatile
electrically erasable PROM (E2PROM) and the
AUTOSTORE feature which automatically saves the
RAMcontentstoE2PROMatpower-down. TheX20C17
isfabricatedwithadvancedCMOSfloatinggatetechnol-
ogy to achieve high speed with low power and wide
power-supply margin. The X20C17 features a compat-
ible JEDEC approved byte-wide memory pinout for
industry standard SRAMs.
—Endurance: 1,000,000 Nonvolatile Store
Operations
—Retention: 100 Years Minimum
• AUTOSTORE™ NOVRAM
—Automatically Stores SRAM Data Into the
E2PROM Array When VCC Low Threshold is
Detected
—E2PROM Data Automatically Recalled Into
RAM Upon Power-up
The NOVRAM design allows data to be easily trans-
ferred from RAM to E2PROM (store) and E2PROM to
RAM (recall). The store operation is completed in 2.5ms
or less. An automatic array recall operation reloads the
contents of the E2PROM into RAM upon power-up.
• 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
A
A
1
24
23
22
21
20
19
18
17
16
15
14
13
V
A
A
7
6
5
4
3
2
1
0
0
1
2
CC
8
2
A
3
9
A
4
WE
OE
A
5
6
A
A
10
X20C17
7
A
CE
8
A
I/O
7
I/O
6
I/O
5
I/O
4
9
I/O
I/O
I/O
V
10
11
12
I/O
3
SS
2015 ILL F02.1
AUTOSTORE™ NOVRAM is a trademark of Xicor, Inc.
©Xicor, Inc. 1992, 1995 Patents Pending
2015-2.5 8/1/97 T1/C0/D0 SH
Characteristics subject to change without notice
1
XICOR [ XICOR INC. ]
