| 摘要 |
PURPOSE:To reduce misaction to the utmost, by providing a circuit for connecting a detector for detecting a state of power supply switches, with a program priority interruption terminal in order to enable rapid response to change of said state. CONSTITUTION:The point A of a transistor 21 is allowed to show a level H by the output of a photocoupler 20 at a level L in an on-state of a main switch SW1. The input at the level H is applied to the input terminal SI of a microcomputer 12, and the input at the level L is fed to a terminal TRAP of a highest priority interruption input. When the switch SW1 is turned off, the input of the terminal SI becomes the level L and that of TRAP the level H. The microcomputer is actuated by the logical product of the rise of TRAP input from L to H and the retention of the level H for a prescribed time, resulting in interrupting a main program routine and allowing the interrupted program to be processed in the highest priority. |
