Patent ID: 7509206

Claim:
An electronic control unit for automobiles comprising: a microcomputer for generating a plurality of control signals for controlling a state of an automobile on the basis of input signals from a plurality of sensors; and plural output driver circuits for driving a plurality of actuators in response to said control signals generated by said microcomputer, said output drive circuits being separated from said microcomputer, and electrically connected to said microcomputer through a serial communication line, a clock signal line and a synchronized signal line; wherein, said output drive circuits include a first output drive circuit for an actuator controlled by a pulse width modulation signal, and a second output drive circuit for an actuator controlled by a pulse signal that is synchronized with engine rotation; each of said output drive circuits comprises a driver IC which has integrated therein power transistors corresponding to a plurality of channels, a serial communication interface for executing serial communication with said microcomputer, and a timer circuit for generating said pulse width modulation signal or said pulse signal for said power transistors; said microcomputer is configured to supply a clock signal for timer count generated by a microcomputer-side oscillator to said timer circuits of said first and second output drive circuits via said clock signal line, transmit a first control data signal for setting a frequency and duty factor of said pulse width modulation signal to said first output drive circuit via said serial communication line, transmit a second control data signal for setting output start timing and output end timing or output start timing and pulse width of said pulse signal to said second output drive circuit via said serial communication line, and supply an engine rotation synchronized signal generated at said microcomputer-side, based on a crank angle sensor signal and a cam angle sensor signal, via said synchronized signal line; said timer circuit of said first output drive circuit generates said pulse width modulation signal based on said first control data signal received from said microcomputer by said serial communication interface; and said timer circuit of said second output drive circuit generates said pulse signal on the basis of the second control data signal received from said microcomputer by said serial communication interface and said engine rotation synchronized signal supplied from said microcomputer.