Patent ID: 6952139
Filing Date: 2005-10-04
Classification: G04F,G07C

Abstract:
1. An oscillator operated with an external power source or an external save power source used at a power-off time of the external power source, comprising: a clock signal generation unit generating and outputting clock signals having predetermined frequencies; a power-on detection unit detecting a power-on event of the external power source and outputting power-on detection signals; a power-off detection unit detecting a power-off event of the external power source and outputting power-off detection signals; storage storing accumulated running time up to a power-on time of the external power source; a running time count unit inputting the clock signals from the clock signal generation unit and counting running time from a time of the power-on detection signals being input to a time of the power-off detection signals being input; and a control unit reading the running time at the time of the power-off detection signals being input, reading the accumulated running time from the storage, adding the running time to the accumulated running time to yield an addition result, and storing the addition result as a new accumulated running time in the storage.