A brushless DC motor includes an embedded memory of a micro computer mounted on a circuit board which can be modified during and/or after a manufacturing process of the brushless DC motor. The circuit board installed on the brushless DC motor includes an IC having the embedded micro computer executing feed back control of the pulse wide modulation and the embedded memory for storing data such as control programs. The circuit board also includes a writing terminal port to which an external memory writer is to be connected. Data is transferred from the external memory writer and stored in the embedded memory by contacting the writing terminal port with a tip end portion of a cable from the external memory writer.