| 摘要 |
PROBLEM TO BE SOLVED: To surely detect runaway of a CPU, in an ignition device for an internal combustion engine for controlling ignition timing by the CPU. SOLUTION: A port P3 of the CPU is used as a reset state determination port and is set so as to acquire a high level voltage signal from the port P3 in runaway of the CPU. The ignition device comprises: a light-emitting diode LED to which voltage of a battery 5 is applied through a thyristor Th; a trigger signal output circuit 12 for sending a trigger signal to the thyristor Th when the CPU is runaway and the voltage signal from the port P3 shows a high level; switch control circuit 15 for a trigger signal bypass, preventing transmission of the trigger signal from the trigger signal output circuit 12 to the thyristor Th during a period of power-on reset of the CPU, and permitting the transmission of the trigger signal to the thyristor after the completion of the power-on reset and the start of the CPU. COPYRIGHT: (C)2005,JPO&NCIPI
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