JUDGING DEVICE OF OSCILLATED CLOCK OF MICROCOMPUTER

摘要

PURPOSE:To issue an alarm when an abnormality is generated at an oscillation circuit to be used in a backup state. CONSTITUTION:The state of an oscillation clock having a specific oscillated frequency is judged by a judging circuit 17 as necessary, and the alarm is used from an alarming part 19 when the judged result indicating the abnormal state of the oscillation clock. Therefore, the abnormality of the oscillation clock can be easily recognized when the the oscillation clock is used in order to perform a backup operation by a microcomputer at the time of the occurrence of a power failure or the like.