The X40420, X40421 combines power-on reset control, watchdog timer, supply voltage supervision, and secondary supervision, manual reset, and Block Lock™ protect serial EEPROM in one package. This combination lowers system cost, reduces board space requirements, and increases reliability. Applying voltage to VCC activates the power-on reset circuit which holds RESET/RESET active for a period of time. This allows the power supply and system oscillator to stabilize before the processor can execute code.