The CAT1232LP and CAT1832 microprocessor supervisors can halt and restart a “hung-up” or “stalled” microprocessor, restart a microprocessor after a power failure, and debounce a manual/pushbutton microprocessor reset switch. The devices are drop in replacements for the Maxim/Dallas Semiconductor DS1232LP and DS1832 supervisors Precision reference and comparator circuits monitor the 5 V or 3.3 V system power supply voltage, VCC. During power-up or when the power supply falls outside selectable tolerance limits, both the RESET and RESET ¯¯¯¯¯¯ become active. After the power supply voltage rises above the RESET threshold voltage, the reset signals remain active for a minimum of 250ms, allowing the power supply and system processor to stabilize. The trip-point tolerance input, TOL, selects the trip level tolerance to be either 5% or 10% for the CAT1232LP 5 V supply and 10% or 20% for the CAT1832 3.3 V supply. Each device has a push-pull, active HIGH reset output. The CAT1232LP also has an open drain, active LOW reset output while the CAT1832 also has a push-pull, active LOW reset output. A debounced manual reset input activates the reset outputs and holds them active for a minimum period of 250 ms after being released. Also included is a watchdog timer to reset a microprocessor that has stopped due to a software or hardware failure. Three watchdog time-out periods are selectable: 150 ms, 600 ms and 1.2 s. If the ST¯¯ input is not strobed low before the watchdog time out period expires, the reset signals become active for a minimum of 250 ms.