DS1232 monitors three vital conditions for a microprocessor: power supply, software execution and external override. First, a precise temperature-compensated reference and comparator circuit monitors the status of the VCC. When an out-of-tolerance condition occurs, an internal power failure signal is generated, forcing a reset to the active state. When VCC returns to a tolerance state, reset signals are kept active for a minimum of 250 ms to allow the power supply and processor to stabilize.