| 摘要 |
PURPOSE:To simplify a runaway monitor system by deciding a CPU that it is in a runaway state when the number of times of triggering exceeds a fixed level within a period of the processing loop of a main program. CONSTITUTION:For a main program the initialization is given to a software counter within a loop where the peripheral devices are processed. Then the counter is counted up by an interruption routine every time an interruption is received from a pulse generator 6. A trigger pulse is delivered to an output port 4 only when the count value CT is equal to or smaller than the set value N. Thus an NMI interruption is never applied to a CPU 1. When the CPU 1 has a runaway, the main program or the interruption routine has no normal operation and therefore no trigger pulse is sent from the port 4. Then a one-shot circuit 5 is not triggered again and the NMI interruption is applied to the CPU 1.
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