| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To surely detect an input signal with optional length with less power consumption. <P>SOLUTION: A real time clock device 10 includes: an oscillation part 12 which outputs a master clock signal with predetermined frequency; a plurality of frequency division parts 14 which frequency-divide the master clock signal outputted by the oscillation part 12 to generate clock signals with mutually different frequencies; a clock selection circuit 16 which outputs clock signals with optional frequencies outputted by the frequency division parts 14 based on a given selection signal; and a signal detection circuit 30 which is connected to an external switch 40, detects the length of the inputted signal by the clock signal outputted by the clock selection circuit 16 and detects whether or not the inputted signal is an input signal from the switch 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
