In some preferred embodiments, a motor control circuit 1 for controlling driving of a plurality of motors 3 and 4 includes a serial communication circuit configured to perform serial communication with an outside, a received data storage 15 configured to store data from the serial communication circuit, a motor mode setting holding circuit 16 configured to store motor mode settings which decide operations of the motors, and a detection circuit 24 configured to detect changes in driving pulse of the motor. Depending on the detected result of the detection circuit 24, the data stored in the received data storage 15 is transferred to the motor mode setting holding circuit 16.