| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To immediately detect a malfunction in a timer apparatus having highly accurate oscillators when malfunctions such as degraded accuracy and a stoppage of the oscillators occur, and to continuously supply an accurate time after the malfunctions of the oscillators have occurred. <P>SOLUTION: The timer apparatus comprises a plurality of timer counters 4-6, the oscillators 1-3 which increments the timer counters, and a selection circuit for selecting one timer counter to be used for output among the plurality of timer counters. The timer apparatus has multiplexed oscillators 1-3 and timer counters 4-6 in the timer apparatus, and detects the malfunction of the timer by searching an error from a reference value for every timer, in which an average value of every timer or an externally entered reference time is set up as the reference value. Further, an order for the accuracy of every timer is maintained, and a value of the next accurate timer is selected when the most accurate timer fails. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
