DEVICE AND METHOD FOR MONITORING SOURCE VOLTAGE AND RECORDING MEDIUM WHERE SOURCE VOLTAGE MONITORING PROCESS PROGRAM IS RECORDED

摘要

PROBLEM TO BE SOLVED: To monitor an accurate source voltage corresponding to the kind of a battery in use when the battery is used as a power source. SOLUTION: The device has an A/D converting means 42 which converts the source voltage into a digital signal, a timer means 46 which outputs a timing signal having specific cycles, an A/D conversion control means 45 which receives the timing signal and inputs the source voltage to the A/D converting means 42 in every specific cycles, a reference voltage setting means 44 which sets a reference voltage, and a comparing means 43 which compares the digitized source voltage with the reference voltage and outputs an interruption signal s1 to a CPU 30 when the source voltage drops below the reference voltage, and performs voltage monitoring operation independently of the CPU 30 after the CPU 30 initially sets the cycle of the timing signal and reference voltage.