ASM1232LP

The ASM1232LP/LPS is a fully  integrated microprocessor supervisor. It can halt and restart a "hung-up" microprocessor,restart a
microprocessor after a power failure. It has a watchdog timer and external reset override. A precision temperature-compensated
reference and comparator circuits monitor the 5V, V_CC  input voltage status.

During power-up or when the V_CC  power supply falls outside selectable tolerance limits, both RESET and RESET   become active.
When V_CC  rises above the threshold voltage, the reset signals remain active for an additional 250ms minimum,allowing the power
supply and system microprocessor to stabilize. The trip point tolerance signal, TOL, selects the trip level tolerance to be either 5% or 10%.

Each device has both a push-pull, active HIGH reset output and an open drain active LOW reset output. A debounced manual reset
input,   PBRST  ,  activates the reset outputs for a minimum period of 250ms.

There is a watchdog timer to stop and restart a microprocessor that is "hung-up". The watchdog timeouts periods are selectable:
150ms, 610ms and 1200ms. If the ST  input is not strobed LOW before the time-out period expires, a reset is generated.