A
PPLICATION
N
OTES
A V A I L A B L E
AN3 • AN7 • AN8 • AN15 • AN16 • AN25 • AN29
• AN30 • AN35 • AN36 • AN39 • AN56 • AN69
X24C44
256 Bit
X24C44
Serial Nonvolatile Static RAM
16 x 16 Bit
FEATURES
DESCRIPTION
The Xicor X24C44 is a serial 256 bit NOVRAM featuring
a static RAM configured 16 x 16, overlaid bit-by-bit with
a nonvolatile E
2
PROM array. The X24C44 is fabricated
with Xicor’s Advanced CMOS Floating Gate technology.
The Xicor NOVRAM design allows data to be transferred
between the two memory arrays by means of software
commands or external hardware inputs. A store opera-
tion (RAM data to E
2
PROM) is completed in 5ms or less
and a recall operation (E
2
PROM data to RAM) is com-
pleted in 2µs or less.
Xicor NOVRAMs are designed for unlimited write opera-
tions to RAM, either from the host or recalls from
E
2
PROM and a minimum 1,000,000 store operations.
Inherent data retention is specified to be greater than
100 years.
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Advanced CMOS Version of Xicor’s X2444
16 x 16 Organization
Single 5 Volt Supply
Ideal for use with Single Chip Microcomputers
—Static Timing
—Minimum I/O Interface
—Serial Port Compatible (COPS™, 8051)
—Easily Interfaced to Microcontroller Ports
Software and Hardware Control of Nonvolatile
Functions
Auto Recall on Power-Up
TTL and CMOS Compatible
Low Power Dissipation
—Active Current: 10mA Maximum
—Standby Current: 50
µ
A Maximum
8-Lead PDIP, Cerdip, and 8-Lead SOIC Packages
High Reliability
—Store Cycles: 1,000,000
—Data Retention: 100 Years
FUNCTIONAL DIAGRAM
NONVOLATILE
2
E PROM
ROW
DECODE
STATIC
RAM
256-BIT
EC
AL
L
ST
O
R
E
CONTROL
LOGIC
R
RECALL (6)
STORE (7)
CE (1)
DI (3)
SK (2)
INSTRUCTION
REGISTER
COLUMN
DECODE
DO (4)
INSTRUCTION
DECODE
4-BIT
COUNTER
3832 FHD F01
COPS is a trademark of National Semiconductor Corp.
© Xicor, Inc. 1991, 1995, 1996 Patents Pending
3832-1.5 6/19/96 T2/C1/D1 NS
1
Characteristics subject to change without notice
XICOR [ XICOR INC. ]
