| 摘要 |
<p>PURPOSE:To improve the reliability of whole system by providing a control circuit for setting an output terminal to a high impedance at the time of detecting the abnormality of the system. CONSTITUTION:When the abnormal operation of the system is detected, a counter 1 outputs an overflow, so that an interruption signal is made active and further a control signal 15 is made inactive, and the terminal 16 is brought into the high impedance. Then, a user connects a pull up resistance 18 or a pull down resistance 19 to the terminal 16, thereby, the signal level of the terminal can be arbitrarily set to either of a high level or a low level.</p> |
