| 摘要 |
PROBLEM TO BE SOLVED: To reduce power consumption and radio noise in a vehicular electronic control unit including a microcomputer and a port extension element.SOLUTION: A microcomputer (MCU) performs deciding processing to decide whether an output condition based on a signal to be inputted through a signal input port of the microcomputer is established (S2). Further, if the output condition is established, the MCU 2 transmits a signal output command to a port extension element through a communication port. If not, the MCU 2 does not transmit the command (S2, S3). The port extension element outputs a signal through a signal output port according to the command sent from the MCU 2 (S11). Further, depending on whether communication with the MCU 2 is paused, the port extension element 3 autonomously chooses whether the port extension element acts in a standby mode, in which an internal oscillation circuit is inactivated, or in a normal mode in which the internal oscillation circuit is activated (S10, S12). |
