| 摘要 |
PURPOSE:To protect a pulse motor from the uncontrolled operation of a central processing unit only by adding two flip-flops and several gates in addition to a timer fundamentally required for driving the pulse motor. CONSTITUTION:When a central processing unit CPU is not operated normally, there is the uncontrolled run-away of the CPU due to noises as a cause thereof. The CPU does not react even when an output tout from a timer TM is outputted at that time, thus resulting in no change of the data of a port P. Since a signal (a) is not also outputted at that time, an output signal (b) from a FF 1 is left as it is '0', an output signal port from a FF 2 reaches '0' because an input signal to the FF 2 takes '0' when the next output tout is generated, AND gates G1-1-G1-4 are closed in response to the '0' of the output signal port, all P1-P3 signals reach '0', thus stopping driving of a motor. |
