| 摘要 |
Reliably detecting malfunction of an abnormality-monitoring circuit during operation of a processing unit. An electronic control unit provided with a CPU level-inverts and outputs an actuating signal during each iteration of a base routine. An abnormality-monitoring circuit clocks a fall interval of the actuating signal as charging voltage of a gradually discharged capacitor, and outputs a reset signal to the CPU when this charging voltage falls to a defined value. When a check-starting condition is fulfilled, the CPU inhibits a subsequent level inversion of the actuating signal until a predetermined time elapses after a prior level inversion. When the signal inhibition is canceled, when the charging voltage VC of the capacitor is not within a reference range (VL-VH), the CPU determines the abnormality-monitoring circuit to have malfunctioned. |
