Patent ID: 8996927
Filing Date: 2015-03-31
Classification: G06F,H02J

Abstract:
1. An electronic control device comprising: a processing unit that performs a predetermined process in accordance with a program; a watchdog timer that includes a time counter reset by a pulse signal output at a given period from the processing unit and outputs a signal having levels inverted depending on whether an overflow occurs; a latch circuit that latches the signal output from the watchdog timer and outputs a signal obtained through the latching as a first output enable signal; and an AND circuit that calculates a logical AND of the first output enable signal output from the latch circuit and a second output enable signal output from the processing unit and outputs a signal indicating the calculation result as a final output enable signal, wherein the processing unit stops the output of the pulse signal, when diagnosing a malfunction of the watchdog timer, and diagnoses the malfunction of the watchdog timer based on the first output enable signal output from the latch circuit and the final output enable signal output from the AND circuit, after stopping the output of the pulse signal.