Abstract: According to one embodiment, a magnetic memory device includes: a first interconnect; a second interconnect; a first switching element provided on the first interconnect; a second switching element provided on the second interconnect; a first insulating layer provided surrounding the first switching element; a second insulating layer surrounding the second switching element and not being in contact with the first insulating layer; a first conductor provided on the first switching element and the first insulating layer; a second conductor provided on the second switching element and the second insulating layer; a first magnetoresistive effect element provided on the first conductor; and a second magnetoresistive effect element provided on the second conductor.

Abstract: A PWM motor drive device includes: a time counter that counts a time of a polarity of a motor phase signal; a register that retains the time; a zone setting circuit that splits the time into arbitrary zones and generates an arbitrary zone set for which a phase of motor current is adjusted; and a zone correction circuit that compares a motor current phase signal indicating the phase of the motor current with the motor phase signal to correct the zone set.

Abstract: A PWM motor drive device includes: a time counter that counts a time of a polarity of a motor phase signal; a register that retains the time; a zone setting circuit that splits the time into arbitrary zones and generates an arbitrary zone set for which a phase of motor current is adjusted; and a zone correction circuit that compares a motor current phase signal indicating the phase of the motor current with the motor phase signal to correct the zone set.

Abstract: A servo control device includes: a phase compensator configured to generate a plurality of types of control values for controlling a driver based on a signal output from an optical pickup, and output the control values; and a transfer data generator configured to serially transfer the control values to the driver. The phase compensator sends, to the transfer data generator, a notification that the phase compensator has output a control value which needs to be sent with a reduced delay among the control values. In response to the notification, the transfer data generator determines whether or not the transfer data generator is transferring one of the control values, and if the transfer data generator is not transferring one of the control values, the transfer data generator starts transferring a control value associated with the notification among the control values.

Abstract: A sensorless motor drive device has: a first operation mode of generating current waveforms including non-energizing times based on a first rotor position signal generated by detecting zero crossings in windings of a motor as a signal indicating the rotor position of the motor, and supplying currents to the windings of the motor according to the current waveforms; and a second operation mode of generating current waveforms including no non-energizing time based on a second rotor position signal generated without use of zero crossings as the signal indicating the rotor position of the motor, and supplying currents to the windings of the motor according to the current waveforms. The first and second operation modes can be switched to each other.

Abstract: The precision of a direction detection signal DIR is judged from the duty ratio of the direction detection signal DIR, and the direction detection signal DIR which is used for track search control or tracking pull-in control is judged as valid or invalid according to the precision, thereby to improve the precision of the track search control or the tracking pull-in control. Therefore, even when the direction detection is not performed accurately due to a difference in the reflected light quantity on the optical disk, a defect on the optical disk, a delay in the track cross speed during search, or a delay in the detection circuit, the track search control and the tracking pull-in control can be performed with stability.