DIGITAL CIRCUIT CONTROLLER

摘要

PROBLEM TO BE SOLVED: To reset a CPU after the sure power interruption processing is carried out by dividing the voltage of a battery power supply so as to set the 1st voltage at a level higher than the 2nd voltage. SOLUTION: A reference voltage generation circuit 1 generates the reference voltage VREF and an interrupt signal generation circuit 3 generates an interrupt signal D to save the data stored in a CPU 17 into a backup memory 18 when the 1st voltage obtained by dividing the voltage VCC of a battery power supply 11 is kept at a level lower than the voltage VREF A reset signal generation circuit 2 generates a reset signal E to reset the CPU 17 when the 2nd voltage obtained by dividing the voltage VCC of the power supply 11 dropped less than the voltage VREF. The signal E is canceled when a prescribed time elapsed after the 3rd voltage obtained by dividing the voltage VCC of the power supply 11 exceeds the voltage VREF. A power OFF signal generation circuit 4 generates a power OFF signal F to turn off a power supply circuit 12. Then the voltage VCC of the power supply 11 is divided so as to satisfy the 2nd voltage < the 1st voltage < the 3rd voltage.