x25045 pdf

The X25043/45 combines three popular functions,
Watchdog Timer, Voltage Supervision, and E2PROM in
a single package. This combination lowers the system
cost and reduces the board space requirements.
The Watchdog Timer provides an independent protection
system for microcontrollers. During a system failure,
the X25043/45 watchdog will respond with a RESET/
RESET signal after a selectable time-out interval. The
user selects the interval from three preset values. Once
selected, the interval does not change, even after cycling
the power.
The system is protected from low voltage conditions by
the X25043/45 low VCC detection circuits. When VCC
drops below the minimum VCC trip point, the system is
reset. Reset is asserted until VCC returns and stabilizes.
The memory portion of the X25043/45 is a CMOS 4096-
bit serial E2PROM, internally organized as 512 X 8. The
X25043/45 features a Serial Peripheral Interface (SPI)
and software protocol allowing operation on a simple
three-wire bus.
The X25043/45 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.