| 摘要 |
PURPOSE:To detect instantaneously all runaways of a program by setting plural pass points to the program an checking the program pass in order of these points. CONSTITUTION:A ROM2, a RAM3, a process input/output device 4, a timer 6 and a pass point detecting circuit 7 are connected to a CPU1 via a bus 9. Then detection signals CS1-CS3 are supplied to clock terminals of FF11-13 from the circuit 7. If a program has a runaway owing to an IC defect, etc. caused by the external noises, signals CS1-CS3 are delivered in that order excepting the SC2. Thus the FF13 is reset and the signal CS3 is delivered. Thus both FF12 and 13 are not cut and no clear signal CLR is delivered. Then a counter 8 is counted up and delivers an alarm signal. |
