The X40626 combines four popular functions, Power-on Reset Control, Watchdog Timer, Dual 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 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 signal. The user selects the interval from three preset values. Once selected, the interval does not change, even after cycling the power.