Electronic control apparatus with defined reset function

Abstract

To provide for starting of signal processing operations in a microprocessor (7), for example an automotive-type microprocessor, subject to frequent power interruptions, in which the processing operations are controlled by clock signals from a clock generator (1), and to insure that the microprocessor carries out its computation cycles only after the clock signal generator (1) provides clock signals at an adequate level appropriate for microprocessor operations, the level of the clock signals is sensed, for example in a peak rectifier (2, 3, 5) to reset the microprocessor when the clock signals have reached this level, thereby insuring commencing of processing cycles from a predetermined condition or state of the microprocessor at a time when adequate clock signals are available. The reset signal from the clock generator can be logically combined in a logic circuit (6) with externally generated reset signals, for example dependent on sufficient or suitable operating voltage being present for operation of the microprocessor from a power source (P), for example the battery of an automotive vehicle, to insure operation of the microprocessor only with adequate battery voltage being present, for example after termination of power drain by a starter motor.