According to an embodiment, a motor control circuit includes a rotational position decoding unit, a rotational position determining unit, and a motor drive signal generating unit. The rotational position decoding unit is configured to generate a rotational position signal representing a rotational position of a motor according to a sensor signal provided by a sensor. The rotational position determining unit is configured to store a current rotational position of the motor based on the rotational position signal. When the rotational position signal represents a subsequent rotational position of the stored current rotational position, the rotational position determining unit is configured to update the stored current rotational position with the subsequent rotational position, and generate a motor control signal representing the subsequent rotational position. The motor drive signal generating unit is configured to generate a motor drive signal for driving the motor according to the motor control signal.