APPLICATION NOTE
A V A I L A B L E
AN84
128K
16K x 8 Bit
X24F128
2-Wire SerialFlash with Block Lock™ Protection
FEATURES
DESCRIPTION
• Save Critical Data with Programmable Block
Lock Protection
The X24F128 is a CMOS SerialFlash Memory, inter-
nally organized 16K x 8. The device features a serial
interface and software protocol allowing operation on a
simple two wire bus.
—Block lock (0, 1/4, 1/2, or all of E2PROM array)
—Software program protection
—Programmable hardware program protect
• In Circuit Programmable ROM Mode
• Longer Battery Life with Lower Power
—Active read current less than 1mA
—Active program current less than 3mA
—Standby current less than 1µA
• 1.8V to 3.6V or 5V “Univolt” Read and Program
Power Supply Versions
Three device select inputs (S –S ) allow up to eight
0
2
devices to share a common two wire bus.
A Program Protect Register at the address location
FFFFh provides three program protection features: Soft-
ware Program Protect, Block Lock Protect, and Hardware
Program Protect. The Software Program Protect feature
prevents any nonvolatile writes to the device until the PEL
bit in the Program Protect Register is set. The Block Lock
Protection feature allows the user to individually block
protect four blocks of the array by programming two bits
in the Program Protect Register. The Programmable
Hardware Program Protect feature allows the user to
• 32 Word Sector Program Mode
—Minimizes total program time per word
• 100KHz 2-Wire Serial Interface
• Internally Organized 16K x 8
• Bidirectional Data Transfer Protocol
• Self-Timed Program Cycle
—Typical program cycle time of 5ms
• High Reliability
—Endurance: 100,000 cycles
install the device with PP tied to V , program the entire
CC
memory array in circuit, and then enable the hardware
program protection by programming a PPEN bit in the
Program Protect Register. After this, selected blocks of
the array, including the Program Protect Register itself,
are permanently protected from being erased.
—Data retention: 100 years
• 8-Lead DIP
• 16-Lead SOIC
Xicor SerialFlash Memories are designed and tested
for applications requiring extended endurance. Inher-
ent data retention is greater than 100 years.
BLOCK DIAGRAM
Data Register
Serial Flash Data
and Address (SDA)
Y Decode Logic
Serial Flash
Command
Array
SCL
Sector
Decode
Logic
Decode
16K x 8
and
Control
Logic
4K x 8
Block Lock and
Program Protect
Control Logic
4K x 8
8K x 8
S
S
S
2
1
0
Device
Select
Logic
Write
Protect
Logic
Program Voltage
Control
PP
Xicor, Inc. 2000 Patents Pending
7012-0.8 11/4/03 EP
Characteristics subject to change without notice. 1 of 16