Abstract: A set-top box is connectable to a digital video recorder that includes at least one recorder interface that supports connection of the digital video recorder to the set-top box, and a disk that stores a selected video segment. The digital video recorder has a video data stream manager that, in response to a real-time video signal, provides a first video stream to store the selected video segment on the disk, and that, in response to a command from the set-top box that initiates a playback interval, receives a second video stream based on the selected video segment stored on the disk to generate a recorded video signal. The digital video recorder is configured to (a) continuously receive the real-time video signal from the set-top box, and (b) provide the recorded video signal to the set-top box during the playback interval.

Abstract: A method and an apparatus select the spindle rotation speed for writing servo tracks to a disk based on measured performance of the head-disk assembly. The position error values are measured and analyzed to generate a position error metric. Based on the value of the position error metric, a spindle rotation speed is selected for use when writing servo tracks to a disk.

Abstract: A disk drive is disclosed comprising a voice coil motor (VCM) actuator and a piezoelectric (PZT) actuator. The VCM actuator is driven by a control effort including an integrator, and the PZT actuator is driven by a control effort including a transformer.

Abstract: An air bearing slider for use in a disk drive. The slider includes a leading side and an opposing trailing side. The slider includes a pair of opposing lateral sides disposed between the leading and trailing sides. The slider includes a leading side air bearing surface including a main portion adjacent the leading side and a trailing portion extending from the main portion toward the trailing side along a respective one of the lateral sides. The slider includes a side rail disposed laterally along and between the respective lateral side and the trailing portion. The slider includes a channel formed between the side rail and the trailing portion disposed angularly with respect to the respective lateral side by extending from adjacent the respective lateral side towards the trailing side away from the respective lateral side for receiving airflow through the channel during operation of the disk drive.

Abstract: A disk drive is disclosed comprising a disk and a semiconductor memory comprising addressable locations for staging and caching data, wherein each addressable location having an allocation status. When a large write command is received from a host to write write-data to the disk, a disk controller dynamically allocates a plurality of the addressable locations relative to the size of the write command and the allocation status of the addressable locations. The write-data received from the host is stored in the dynamically allocated addressable locations while concurrently reading the write-data from the dynamically allocated addressable locations and writing the write-data to the disk. The dynamically allocated addressable locations are re-used for storing write-data received from the host after writing the write-data to the disk.

Abstract: A switched node for use in a multi-dimensional switched fabric network is disclosed. The switched node comprises adapter circuitry connected to receive asynchronous and isochronous packets from an external entity. Each asynchronous packet comprises destination node routing information and data, and each isochronous packet comprises a path ID corresponding to a reserved path through the network, an arrival time parameter identifying a target arrival time of the isochronous packet into the switched node, and data. An asynchronous-to-isochronous converter converts the asynchronous packets into isochronous packets comprising the data from the asynchronous packets.

Abstract: A spindle motor for use in a disk drive includes a spindle motor base. The spindle motor further has a spindle motor hub rotatably attached to the spindle motor base. The spindle motor further has a motor shaft in mechanical conmmunication with the spindle motor base. The spindle motor further has an inner ball bearing set surrounding the motor shaft. The inner ball bearing set has a first inner race and a first outer race. The first inner race is attached to the motor shaft. The spindle motor has an outer ball bearing set surrounding the inner ball bearing set. The outer ball bearing set has a second inner race and a second outer race. The second inner race is fixed relative to the first outer race.

Abstract: A disk drive control system that compensates for mechanical bias torques present in disk drives. A transducer, commonly referred to as a head, is attached to an actuator arm that is subjected to mechanical bias torques, including flex bias torque and bearing friction. The net bias torque has a mechanical memory that is manifested as hysteresis whose magnitude depends on the size of the stroke length between inflection points of the transducer in seek operations. The dependence of the net bias torque includes location of the transducer, direction of the seek, and the history of previous seeks. The dependence may further include operating temperature of the disk drive. The disk control system determines and applies these corrections to the disk drive to enhance the seek performance.

Abstract: A disk drive and method are disclosed for data transfer initiated by nonstandard disk-drive commands on a serial ATA interface that only supports standard ATA disk-drive commands. In the method, a nonstandard disk-drive command for data transfer is embedded within a first data block accessible using a first standard disk-drive command. The first standard disk-drive command is transmitted through the serial ATA interface causing the first data block to be transferred from the host computer to the disk control system. The embedded command is extracted from the transferred first data block and provided to the disk control system. A status response is transmitted to the host computer based on the extracted command. At least one additional standard disk-drive command is transmitted through the serial ATA interface to the disk control system for transferring the identified data between the host computer and the disk drive.

Abstract: A method is disclosed for seeking from first radial position on a spiral track of a magnetic disk drive to a second radial position. The disk having the spiral track rotates at a constant angular velocity. The servo sectors on the spiral track may not be aligned along a radius. A head transit time is determined for moving the head to the second radial position. A first control current pulse is applied to an actuator to move the head toward the second radial position. A timer is commenced for measuring the expiration of the head transit time after applying the first control current pulse. After expiration of the head transit time, a second control current pulse is applied to the actuator to terminate the head movement. At least one servo sector along the spiral track is then read to locate the position of the head.

Abstract: The invention relates to a method for recovering from shock event to a disk drive. Embedded servo wedges are read to generate position error signal (PES) values. The disk drive is transitioned to a write unsafe state if a PES value is greater than a write unsafe (WUS) threshold and is less than a shock detection threshold. The disk drive is transitioned to a shock recovery state if a PES value is greater than the shock detection threshold. The disk drive is transitioned from the shock recovery state to the write unsafe state if a first number of consecutively generated PES values remain less than the WUS threshold. The disk drive is transitioned from the write unsafe state to the on-track state if a second number of consecutively generated PES values remain less than the arrival threshold, which threshold is less than the WUS threshold.

Abstract: A disk drive comprising a disk for storing encrypted data is disclosed. The disk drive comprises a first circuit for providing plaintext data to a second circuit. The second circuit comprises controllable encryption circuitry for encrypting the plaintext data into the encrypted data. The controllable encryption circuitry comprises a data input, an enable input, and a data output. The second circuit further comprises a plaintext input for providing the plaintext data to the data input, an encrypted text output for providing the encrypted data from the data output, and a first control input for receiving a first device authentication signal for authenticating the first circuit. The second circuit comprises a first verification circuit, responsive to the first device authentication signal, for producing a first verification signal for use in controlling the enable input of the encryption circuitry to enable the encryption circuitry to provide the encrypted data via the encrypted text output.

Abstract: A pivot bearing cartridge for use in a head stack assembly. The pivot bearing cartridge is provided with a pivot bearing cartridge base. The pivot bearing cartridge is provided with a pivot shaft in mechanical communication with the pivot bearing cartridge base. The pivot bearing cartridge is provided with an inner ball bearing set surrounding the pivot shaft. The inner ball bearing set has a first inner race and a first outer race. The first inner race is attached to the pivot shaft. The pivot bearing cartridge is provided with an outer ball bearing set surrounding the inner ball bearing set. The outer ball bearing set has a second inner race and a second outer race. The second inner race is fixed relative to the first outer race.

Abstract: A hard disk drive comprising an actuator control system that measures the temperature of an actuator coil and methods for providing the same. The control system comprises a controller and a current source controlled by the controller that generates a flow of current through the actuator so as to reposition a transducer of the drive. The control system further comprises sampling means for sampling at least one electrical characteristic of a conducting path defined by the coil. The control system measures the temperature by monitoring the current flowing through the coil and/or the voltage across the coil and by extracting the coil temperature from the monitored values. In one embodiment, the control system obtains a measurement of the coil by successively approximating the resistance of the coil until an estimated back emf component of the voltage across the coil.

Abstract: The base of a disk drive defines an interior shroud surface. The interior shroud surface is configured to follow a portion of the curvature of the disk at a distance from the outer diameter of the disk. The interior shroud surface of the base may define one or more channels for modifying the airflow developed as the disk rotates. The interior shroud surface defines an opening to enable the head stack assembly to pivot over the disk, which opening is bounded by a leading shroud portion and a trailing shroud portion. The leading shroud portion and/or the trailing shroud portion may also define a channel or channels for modifying the airflow that is developed as the disk rotates.

Abstract: A spindle motor for use in a disk drive having a rotatable head stack assembly. The spindle motor has a spindle motor hub having an axis of rotation. The spindle motor has a magnet radially attached about the spindle motor hub. The spindle motor has a spindle motor stator having a stator rim and a plurality of stator teeth arrayed about and internally extending from the stator rim towards the axis of rotation. The stator teeth being are to fit about the magnet in operable communication therewith for rotating the spindle motor hub. Two respective ones of the stator teeth are spaced apart along the stator rim to allow the head stack assembly to pivot between the two respective ones of the stator teeth.

Abstract: A disk drive and methods for preventing a coil in a voice coil motor from overheating due to the application of excess current. The disk drive comprises a servo control system. The servo control system is adapted for applying a current to a coil of the voice coil motor thereby causing the voice coil motor to move the head according to a seek distance. The servo control system generates a plurality of seek profiles for each of a plurality of seek distances and a plurality of current limits for the plurality of seek profiles. Each of the plurality of seek profiles defines a plan for controlling the current to be applied to the coil while the voice coil motor is operated over the seek distance. The plurality of current limits each define a maximum current allowed while controlling the current to be applied to the coil.

Abstract: The present invention relates to a disk drive 10 comprising a cache memory 14 and a cache control system having a tag memory having a plurality of tag records, and means for allocating a tag record for responding to a host command. The cache memory has a plurality of sequentially-ordered memory clusters 46 for caching disk data stored in sectors (not shown) on disks of a disk assembly 38. Conventionally the disk sectors are identified by logical block addresses (LBAs). The cache control system 12 along with the tag memory 22 and means for allocating tag records are embedded within the cache control system 12 and thereby configured only for use in defining variable length segments of the memory clusters 46. The segments are defined without regard to the sequential order of the memory clusters 46.

Abstract: Exemplary embodiments of the present invention are directed to a data storage device and associated method for reproducing a stored data stream with at least one data storage media having addressable storage locations storing data segments and pointers. The data segments define the stored data stream, and the pointers indicate addressable storage locations for other segments in the stored data stream. Each pointer includes a field for identifying whether the data stored includes the addressable storage location of the segment indicated by the pointer. A controller is responsive to the data segments for reproducing a stored data stream in accordance with an autonomously-defined sequence determined by the pointers.

Abstract: The invention relates to a technique for shock estimation and write termination control in a disk drive. During a data write operation, a selected track's embedded servo sectors are read to generate position error signal values. A write unsafe limit is provided for terminating a data write operation if at least one position error signal value exceeds the write unsafe limit. A shock event limit is provided, and if a current position error signal value is less than the write unsafe limit value, then a function value is calculated based on the current position error signal value and a previous position error signal value. If the calculated function value exceeds the shock event limit, a data write operation is terminated. Otherwise, the operation is continued.