A
PPLICATION
N
OTES
A V A I L A B L E
AN9 •
X25020
AN18 • AN31 • AN37 • AN40
2K
X25020
SPI Serial E
2
PROM with Block Lock
TM
Protection
DESCRIPTION
256 x 8 Bit
FEATURES
•
•
•
•
•
•
•
•
•
•
•
1MHz Clock Rate
SPI Modes (0,0 & 1,1)
256 X 8 Bits
—4 Byte Page Mode
Low Power CMOS
—10
µ
A Standby Current
—3mA Active Write Current
2.7V To 5.5V Power Supply
Block Lock Protection
—Protect 1/4, 1/2 or all of E
2
PROM Array
Built-in Inadvertent Write Protection
—Power-Up/Power-Down protection circuitry
—Write Latch
—Write Protect Pin
Self-Timed Write Cycle
—5ms Write Cycle Time (Typical)
High Reliability
—Endurance: 100,000 cycles per byte
—Data Retention: 100 Years
—ESD protection: 2000V on all pins
8-Lead PDlP Package
8-Lead SOIC Package
The X25020 is a CMOS 2048-bit serial E
2
PROM, inter-
nally organized as 256 x 8. The X25020 features a serial
interface and software protocol allowing operation on a
simple three-wire bus. The bus signals are a clock input
(SCK) plus separate data in (SI) and data out (SO) lines.
Access to the device is controlled through a chip select
(CS) input, allowing any number of devices to share the
same bus.
The X25020 also features two additional inputs that
provide the end user with added flexibility. By asserting
the
HOLD
input, the X25020 will ignore transitions on its
inputs, thus allowing the host to service higher priority
interrupts. The
WP
input can be used as a hardwire input
to the X25020 disabling all write attempts, thus providing
a mechanism for limiting end user capability of altering
the memory.
The X25020 utilizes Xicor’s proprietary Direct Write™
cell, providing a minimum endurance of 100,000 cycles
per byte and a minimum data retention of 100 years.
FUNCTIONAL DIAGRAM
STATUS
REGISTER
WRITE
PROTECT
LOGIC
X DECODE
LOGIC
16
SO
SI
SCK
CS
HOLD
COMMAND
DECODE
AND
CONTROL
LOGIC
16
256 BYTE
ARRAY
16 X 32
16 X 32
32
32 X 32
WP
WRITE
CONTROL
AND
TIMING
LOGIC
4
8
Y DECODE
DATA REGISTER
Direct Write
™
and Block Lock
™
Protection is a trademark of Xicor, Inc.
©Xicor, Inc. 1994, 1995, 1996 Patents Pending
3834-1.8 6/10/96 T3/C1/D0 NS
3834 FHD F01
Characteristics subject to change without notice
1
XICOR [ XICOR INC. ]
