Patent ID: 6144887
Filing Date: 2000-11-07
Classification: G05B,G06F

Abstract:
An electronic control unit comprising:a microprocessor, having a nonvolatile memory electrically reloadable with data with a predetermined loading voltage being supplied as a condition, for controlling an object of control during normal operation by executing a control program made up of data stored in the nonvolatile memory and, when a predetermined reloading condition has been established, for carrying out a loading process for loading load data transmitted thereto from outside into the nonvolatile memory as an update and, along with executing the control program, generating at intervals of a predetermined time a monitor signal indicating that it is normal;a system monitoring circuit for monitoring the monitor signal outputted from the microprocessor and, when the monitor signal is not outputted within a time set longer than said predetermined time, outputting to the microprocessor a reset signal for resetting the microprocessor; anda blocking circuit for detecting whether the loading voltage is being supplied to the nonvolatile memory and preventing the microprocessor from being reset by the system monitoring circuit when the loading voltage is being supplied.