Abstract: A reference determiner of a control device for a motor determines, at a predetermined period, a reference rotation angle of the motor as a command value to rotate the motor. When an actual rotation angle of the motor is delayed behind an immediately preceding reference rotation angle determined by the reference determiner and a delay amount is smaller than a predetermined threshold, the reference determiner determines a present reference rotation angle by adding an angle increment corresponding to rotating speed of the motor to the immediately preceding reference rotation angle, and, when the actual rotation angle is delayed behind the immediately preceding reference rotation angle and the delay amount is larger than the threshold, the reference determiner determines the immediately preceding reference rotation angle as the present reference rotation angle.

Abstract: Write commands are received for a Data Storage Device (DSD) to store write data in a plurality of corresponding write locations on at least one disk of the DSD. At least a portion of the write data is cached in at least one Media Based Cache (MBC) region of the at least one disk based on a write cache policy for determining which write data is eligible for caching in the at least one MBC region. The at least one MBC region is used to cache data to be stored in other locations on the at least one disk. During an active time period when host commands are performed on the at least one disk, a portion of an I/O bandwidth for performing commands is used to copy the at least a portion of the write data to corresponding write locations of the plurality of corresponding write locations.

Abstract: A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of servo tracks defined by servo bursts. A number of burst correction values are generated by reading at least one of the servo bursts at a number of different radial locations across the disk. The burst correction values are filtered to generate filtered burst correction values, and the filtered burst correction values are downsampled to generate downsampled burst correction values. The downsampled burst correction values are written to the disk, and the head is servoed over the disk by reading the downsampled burst correction values from the disk.

Abstract: An aspect of the present disclosure relates to implementing a data protection mode based on system vibration modes in a data supported system. An exemplary system vibration mode is associated with an operating mode of the data supported system. The data protection mode operates to limit, or prevent, errors caused by the vibration. In one exemplary embodiment, a method is provided for operating a data supported system. The method includes receiving an indication that a vibration associated with an operating mode of the system will occur and, in response, implementing a data protection mode in the system.

Abstract: An aspect of the present disclosure relates to implementing a data protection mode based on system vibration modes in a data supported system. An exemplary system vibration mode is associated with an operating mode of the data supported system. The data protection mode operates to limit, or prevent, errors caused by the vibration. In one exemplary embodiment, a method is provided for operating a data supported system. The method includes receiving an indication that a vibration associated with an operating mode of the system will occur and, in response, implementing a data protection mode in the system.

Abstract: A data storage device adapted to compensate for physical disturbances has a storage medium, a read-write mechanism positionable relative to the storage medium, and a disturbance observer. The read-write mechanism is adapted to read and write data. The disturbance observer compensates a position of the read-write mechanism according to low-frequency components of physical disturbances.

Abstract: A data storage device adapted to compensate for physical disturbances has a storage medium, a read-write mechanism positionable relative to the storage medium, and a disturbance observer. The read-write mechanism is adapted to read and write data. The disturbance observer compensates a position of the read-write mechanism according to low-frequency components of physical disturbances.

Abstract: Methods relating to compensating a pre-defined seek profile for use in a data storage device, such as a disc drive, to manage the internal temperature of the device are disclosed. One embodiment disclosed is related to determining a seek profile compensation value that can be used to compensate the pre-defined seek profile for temperature. Another embodiment is a method of using a seek profile compensation value during device operation to maintain the data storage device operating temperature below an operating temperature threshold. Yet another embodiment of the present invention may be thought of as a controller for a data storage device. The controller comprises a microprocessor having a pre-determined seek profile and a means for compensating the pre-determined seek profile based on a current operating temperature.

Abstract: Method and apparatus for compensating variations in motor torque in a control system that employs a motor to accelerate a control object, such as a data transducing head in a data storage device. During acceleration of the control object, a plurality of distances successively traveled by the control object are measured, and the measured distances are combined to compensate for said variations in motor torque. Preferably, a constant control input is applied to accelerate the control object at a constant rate of acceleration less than a maximum rate of acceleration that can be obtained by the motor. A coarse adjustment routine is preferably applied to arrive at a first compensation value that compensates for said variations at a first resolution, after which a fine adjustment routine is performed using the first compensation value to arrive at the final compensation value at a second resolution greater than the first resolution.

Abstract: Methods relating to compensating a pre-defined seek profile for use in a data storage device, such as a disc drive, to manage the internal temperature of the device are disclosed. One embodiment disclosed is related to determining a seek profile compensation value that can be used to compensate the pre-defined seek profile for temperature. Another embodiment is a method of using a seek profile compensation value during device operation to maintain the data storage device operating temperature below an operating temperature threshold. Yet another embodiment of the present invention may be thought of as a controller for a data storage device. The controller comprises a microprocessor having a pre-determined seek profile and a means for compensating the pre-determined seek profile based on a current operating temperature.