128K
16K x 8 Bit
X25138
2
TM
5MHz SPI Serial E PROM with Block Lock Protection
FEATURES
DESCRIPTION
• 5MHz Clock Rate
• Low Power CMOS
The X25138 is a CMOS 128K-bit serial E2PROM,
internally organized as 16K x 8. The X25138 features
a Serial Peripheral Interface (SPI) 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.
<1mA Standby Current
<5mA Active Current
• 2.5V To 5.5V Power Supply
• SPI Modes (0,0 & 1,1)
• 16K X 8 Bits
32 Byte Page Mode
• Block Lock™ Protection
Protect 1/4, 1/2 or all of E2PROM Array
• Programmable Hardware Write Protection
In-Circuit Programmable ROM Mode
• Built-in Inadvertent Write Protection
Power-Up/Down protection circuitry
Write Enable Latch
The X25138 also features two additional inputs that
provide the end user with added flexibility. By
asserting the HOLD input, the X25138 will ignore tran-
sitions on its inputs, thus allowing the host to service
higher priority interrupts. The WP input can be used as
a hardwire input to the X25138 disabling all write
attempts to the status register, thus providing a mech-
anism for limiting end user capability of altering 0, 1/4,
1/2 or all of the memory.
Write Protect Pin
• Self-Timed Write Cycle
5ms Write Cycle Time (Typical)
• High Reliability
Endurance: 100,000 cycles
Data Retention: 100 Years
ESD protection: 2000V on all pins
• Packages
The X25138 utilizes Xicor’s proprietary Direct WriteTM
cell, providing a minimum endurance of 100,000
cycles and a minimum data retention of 100 years.
8-Lead XBGA
8, 14-Lead SOIC
8-Lead PDIP
8-Lead TSSOP
FUNCTIONAL DIAGRAM
WRITE
STATUS
PROTECT
REGISTER
LOGIC
X DECODE
LOGIC
16K BYTE
ARRAY
128
128
128 X 256
128 X 256
SO
COMMAND
DECODE
SI
SCK
CS
AND
CONTROL
LOGIC
HOLD
256
256 X 256
WRITE
CONTROL
AND
TIMING
LOGIC
WP
32
8
Y DECODE
DATA REGISTER
Direct WriteÔ and Block LockÔ Protection is a trademark of Xicor, Inc.
7037 FRM F01
ÓXicor, Inc. 1998 Patents Pending
1
Characteristics subject to change without notice
7056–1.5 8/13/98 T2/C0/D1 EW