| 摘要 |
PURPOSE:To always release the runaway of a CPU by monitoring actions of the 1st and 2nd monitor means of a control means through both monitor means with each other and then resetting the control means when one of both monitor means decides the runaway of the other means. CONSTITUTION:A main program executing means 11 first resets a counter 14 set at the interruption side and counts down by 1 the count value of a counter 13 set at the main side to decide whether the value of the counter 13 is equal to 0 or not. When the count value of the counter 13 is equal to 0, it is judged that a timer interruption program executing means 12 has runaway. Thus a CPU 10 is reset. While the means 12 first resets the counter 13 and counts down by 1 the count value of the counter 14 to judge whether the value of the counter 14 is equal to 0 or not. If the value of the counter 14 is equal to 0, the runaway of the means 11 is judged and the CPU 10 is reset. While the counter 3 is reset when the count value of the counter 14 is not equal to 0. When both means 11 and 12 have runaway, a watchdog timer is actuated and the CPU 10 is also reset.
|
