| 摘要 |
PURPOSE:To precisely discriminate a reset signal from an abnormality alarm signal, by controlling a guard circuit so as to output a signal after the discrimination of the reset signal by a control part. CONSTITUTION:The reset signal RST is generated by applying a power source and is inputted to the control part 14, and also, the guard circuit 13 is set at a start up state by the signal RST, and an FF10 as a state holding means is set at a reset state. Meanwhile, the control part 14 monitors the FF10, and can recognize an input signal as the signal RST by recognizing the reset state of the FF10. Also, after the discrimination of the reset signal, the FF10 is set at a set state by the output of a circuit 3, and such state is maintained until the next signal RST is generated. Therefore, it is possible to discriminate the input signal at the set state as an abnormality alarm from the watchdog timer circuit 3 by the control part 14. |
