| 摘要 |
PURPOSE:To detect surely in any runaway mode, by performing counting when no clock signal is generated, and generating a reset signal when its counted value reaches a prescribed value. CONSTITUTION:If the content of a program counter of a control circuit 1 is changed due to external noise such as static electricity, the control circuit 1 runs away and the transmission of an incoming control data signal is stopped thereby, then the clock signal clearing the counter content is not applied to a counter circuit 11. Then, the counter circuit 11 reaches a prescribed value, an output signal is generated, a transistor (TR) 14 is made conductive, resulting in a reset signal is generated from a time constant circuit 15, and the control circuit 1 is initialized. Further, a signal is generated from a time constant circuit 16 through the conduction of the TR14, the counter content of the counter circuit 11 is cleared, and this clearing state is kept until the control circuit 1 starts control operation. |
