| 摘要 |
PURPOSE:To discriminate the reset during application of a power supply from the reset during control by connecting the output of a power supply detecting circuit which supplies the power supply detection signals for a prescribed period of time from the reset during application of power supply to a specific terminal of a microcomputer. CONSTITUTION:An ignition switch 3 is turned on to apply the power supply to a microcomputer 1, and a power supply reset circuit 2 delivers a reset signal. The H-level output of a power supply detecting circuit 8 is detected, and H-level signals are produced by P1 and P2. An inductive load 6 is actuated on trial to check the filament breakage of an alarm lamp 7 as well as perform the reset. Then a fault is detected during control by a fault detecting circuit 5, a reset signal is supplied to the computer 1 via an OR gate 4. In this case, the output of the circuit 8 is set at L level since a fixed period of time elapses after application of a power supply. Thus no output is produced at P1 and P2 and only a reset action is carried out. This circuit improves the system reliability. |
