CIRCUIT DEVICE FOR MONITORING SIGNAL-SEQUENCE FREQUENCY OF ELECTRONIC APPARATUS

PURPOSE: To make it possible to return an electronic device to a normal state again by continuously fornning a periodical error signal or reset signal at the occurance of an error function. CONSTITUTION: The circuit device is provided with a frequency generator 31 capable of forming a periodical error signal sequence or reset signal sequency U31 during a period that prescribed frequency exceeds a measurable deviation at the accurance of an error function appearing as a monitored signal sequence frequency deviation. The signal sequence U31 is continuously formed until a normal function is detected again. Even in the case of a fault applied from the external and held at a long period, normal operation can be automatically attained after easing the fault.