| 摘要 |
<p>PURPOSE:To monitor the action of a central processing unit even when said unit stops its action by supplying clock pulses to watch dog timers supervising the central processing unit and its action from different clock circuits. CONSTITUTION:By receiving the input of clock pulse from the 1st oscillator circuit 14, the CPU12 executes the prescribed arithmetic and logic operations of data transmitted from an external device 16, and transmits the result to the external device 16 again. Meanwhile the watch dog timer 13 obtains timing based on the clock pulse supplied from the 2nd oscillator circuit 15, and supervises the action of the CPU12. When the timer 13 stops the 1st oscillator circuit 14 in order to stop the function of the CPU12, it can obtain timing from the clock pulse concerned and the supervision of the CPU12 can be continued, because the 2nd oscillator circuit 15 continues the supply of clock pulses.</p> |
