| 摘要 |
PURPOSE:To prevent trouble and disasters due to the malfunction by judging a CPU to be abnormal to reset it at the time of detecting that a clock signal is not outputted from a communication means over a prescribed time. CONSTITUTION:An MB3773 is an IC (reset means 14) to monitor the voltage of a power source incorporated in a watchdog timer, and this IC outputs a reset signal when an input CK is not outputted over a set time or the voltage of the power source is reduced to a certain voltage of lower. This reset output is connected to reset terminals of CPUs 13, 7 and 1. Consequently, all CPUs can be reset and restarted when the operation of any CPU is abnormal. Thus, trouble and disasters due to the malfunction are prevented. |
