| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the monitor of microcomputer from being stopped even in the state of detecting an erroneous standby signal. SOLUTION: A watchdog circuit 34 outputs a start signal to a microcomputer 30. An output signal Q of a discrimination circuit 36 is reset by the start signal. When a clock signal CK is inputted from the activated microcomputer 30 and any standby signal st is not detected, an output signal is set at the discrimination circuit 36 but when the standby signal st is detected, this circuit is held in reset state. An AND circuit 38 does not output a standby signal ST by resetting the output signal Q even when the standby signal st is inputted, the watchdog circuit 34 is prevented from starting a standby mode by the standby signal st.</p> |
