X4163, X4165 pdf datasheet (CP

The X4163, X4165 combines four popular functions,
Power-on Reset Control, Watchdog Timer, Supply Voltage
Supervision, and Serial EEPROM Memory in one
package. This combination lowers system cost,
reduces board space requirements, and increases reliability.
Applying power to the device activates the power on
reset circuit which holds RESET/RESET active for a
period of time. This allows the power supply and oscillator
to stabilize before the processor can execute code.
The Watchdog Timer provides an independent protection
mechanism for microcontrollers. When the microcontroller
fails to restart a timer within a selectable
time out interval, the device activates the
RESET/RESET signal. The user selects the interval
from three preset values. Once selected, the interval
does not change, even after cycling the power.
The device’s low VCC detection circuitry protects the
user’s system from low voltage conditions, resetting the
system when VCC falls below the set minimum VCC trip
point. RESET/RESET is asserted until VCC returns to
proper operating level and stabilizes. Four industry
standard VTRIP thresholds are available, however, Intersil’s
unique circuits allow the threshold to be reprogrammed
to meet custom requirements or to fine-tune
the threshold for applications requiring higher precision.