| 摘要 |
PROBLEM TO BE SOLVED: To prevent the defect of a system from being generated by the stop of a CPU facility by forcedly turning the CPU facility to an active state by using a ready enable signal from a retriggerable monostable multivibrator, to which an ALE signal is inputted, when the CPU facility stops longer than prescribed time. SOLUTION: When any one of peripheral interfaces 3a-3n breaks down and a wait request signal 4 is turned to an L state, corresponding to an ALE signal 1c outputted from a CPU facility 1, the operating stop of the CPU facility 1 is detected. When the CPU facility 1 stops longer than the prescribed time, no ALE signal 1c is generated and a retriggerable monostable multivibrator 11 is not triggered. Therefore, a ready enable signal 11a in an H state is inputted from this retriggerable monostable multivibrator 11 t a gate circuit 10 and a ready signal 10a is inputted to a ready input terminal 1a so that wait can be canceled and the CPU facility 1 can be forcedly turned to the active state. Thus, the system defect can be prevented from being generated. |
