MICROCOMPUTER MONITORING METHOD BY WATCHDOG TIMER

摘要

PURPOSE:To monitor a microcomputer suitably for application by providing a watchdog timer where the monitor time is fixed and a watchdog timer where the monitor time can be variably set. CONSTITUTION:When the operation of a microcomputer board 1 is started by power-on or the like, a watchdog timer 3 where the monitor time is fixed is automatically started to monitor the runaway of a microcomputer 2 by a runaway monitor line 5. The microcomputer 2 programs the monitor time of a watchdog timer 4 by a time set and start signal 7 to start the watchdog timer 4, and the watchdog timer 4 starts to monitor the runaway by a runaway monitor line 6, and thereafter, the watchdog timer 3 is stopped, and the microcomputer 2 is operated under the runaway monitor of the programmable watchdog timer 4 hereafter. Thus, monitor most suistable for application is possible.