| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect runway of a CPU more accurately as compared with a conventional method. Ž<P>SOLUTION: A CPU runaway monitoring circuit includes: a timer circuit for performing the timing operation of reset time, and at the end of the timing operation, outputting a timing end signal; a reset signal output circuit for outputting a reset signal to a CPU when the timing end signal is outputted; a holding circuit for holding initialization reception start time for regulating time up to the start of reception of initialization of timing operation; an access monitoring circuit for outputting an initialization signal to the timer circuit when there is no read access and write access of a CPU to the holding circuit before the expiration of the initialization reception start time after starting the timing operation of the timer circuit and when there are read access and write access after the expiration of the initialization reception start time; and an initialization timing setting circuit for setting initialization reception start time differently from a read value when initialization reception start time is read out from the holding circuit, and then setting the set initialization reception start time in the holding circuit. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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