| 摘要 |
PURPOSE:To output a stall detection signal out of a program stall detecting circuit according to the degree of a fault of a CPU, by OR-ing the delay signal of the program stall detecting circuit and a stall permission signal after the execution of a fault processing program. CONSTITUTION:A trigger signal 11 is inputted to a timer 1 periodically by the program of the information processing unit CPU and timer 1 is initialized every time the trigger signal is inputted. If a break of the trigger signal 11 is casued by malfunction of the CPU, a signal output 12 is ceased after the set time of the timer 1 is over. A flip-flop 2 is set at this timing. The output 23 of this flip-flop is the detected result of the program stall, and returned to the CPU as an interruption signal. The CPU accepts the interruption to start the fault processing program for fault processing and then outputs the program stall permission signal 41. |
