Abstract: Some embodiments of the invention are directed to a data storage system that includes a disk and solid-state non-volatile memory (NVM). During a power failure, the data storage system may use back EMF (BEMF) voltage from the spindle motor of the disk to park the heads of the disk and/or store data in the NVM. In one embodiment, a demand regulation circuit regulates loads that use voltage generated from the BEMF. The demand regulation circuit may be used to selectively cause a controller to adjust the rate of programming to the NVM in order to reduce the load. For example, the demand regulation circuit may assert a throttle signal to the controller upon detecting that the voltage generated from the BEMF is below a certain threshold. Programming rate may be throttled, programming cycles may be staggered, and/or programming time may be lengthened. Throttling may enable the use of smaller circuitry.

Abstract: Systems and methods are described for media drive operational data retrieval in a storage library in a manner that is asynchronous with respect to other drive-related communications. Embodiments operate in context of a data storage library having a robotic assembly that ferries media cartridges between media slots and media drives to fulfill requests by host systems. The media drives can communicate with a drive controller over a control path and with host systems over a data path. The drive controller can retrieve operational data from the media drive while the drive is effectively idle, and can communicate the retrieved operational data over the control path to the library. Accordingly, retrieval and communication of the drive operational data can be performed via the control path in a manner that is asynchronous with respect to data path and/or other drive-related communications.

Abstract: A method of correcting repeatable run out (RRO) errors for a HDD in which RRO data is instead stored in consolidated form within the reserved area of the disk, instead of storing RRO data in the servo patterns for each HDD track or sector. RRO data is preferably stored in the reserved area of a hard disk drive in compressed form. The compressed RRO data is subsequently read into DRAM in compressed form and then decompressed for use. Predictive techniques determine what compressed RRO data is needed for upcoming read/write operations.

Abstract: An apparatus of the present disclosure generally includes a recording head, circuitry, a thermal sensor, and a detector. The recording head has an electromagnetic attraction to a recording medium. The circuitry is configured to oscillate the electromagnetic attraction between the recording head and the recording medium. The oscillating electromagnetic attraction produces a corresponding oscillating clearance between the recording head and the recording medium. The thermal sensor, located in or near the recording head, senses an oscillating temperature that is induced by the oscillating clearance and produces a sensor signal that is representative of the sensed temperature. The detector is coupled to the thermal sensor and is configured to detect at least one of head-medium contact and clearance using the sensor signal and the electromagnetic attraction.

Abstract: A method of testing a head for contamination includes detecting a first touchdown power of the head, the head having a flying height actuator; calculating a back-off power for the head using an estimated relationship between back-off power and touchdown power; determining an operating power that is equal to the detected first touchdown power minus the calculated back-off power; passing the head over a magnetic media one or more times while applying the determined operating power to the flying height actuator; detecting a second touchdown power after passing the head over the magnetic media; and determining whether contamination on the head exceeds a threshold amount based on the detected second touchdown power.

Abstract: A disk drive is disclosed comprising a disk comprising a plurality of servo sectors defining a plurality of servo tracks. The servo tracks form a plurality of servo zones, where a servo data rate of servo sectors in a first servo zone is different than a servo data rate of servo sectors in a second servo zone. A servo control system servos a head over the disk. An estimated servo state of a servo control system is generated, and when the head crosses from a first servo zone to a second servo zone, the estimated servo state is adjusted to compensate for a transient in a circumferential distance between a servo sector in the first servo zone and a servo sector in the second servo zone.

Abstract: According to one embodiment, an electronic device includes a housing, a sensor, a disk device, a first determination controller, a first changing controller. The sensor senses a vibration of the housing. The disk device stores operation data, the disk device including a head, wherein the head retracts to a safety position when the sensed vibration exceeds a sensitivity level, and the operation data includes an evaluated value for evaluating an operation state of the head, and a threshold corresponding to the evaluated value. The first determination controller determines whether the evaluated value exceeds the threshold. The first changing controller changes the sensitivity level based on the result of the first determination controller.

Abstract: Records or filemarks read from data segments are aggregated into at least one single data segment. The records and the filemarks are reorganized and restructured in the single data segment such that buffer utilization is improved.

Abstract: A disk drive is disclosed comprising a disk, and a voice coil motor (VCM) operable to rotate an actuator arm about a pivot to actuate a head radially over the disk. A voice coil voltage is measured across the voice coil, a velocity command of the VCM is set to substantially zero, an inductor compensation circuit is toggled at least once by enabling and disabling the inductor compensation circuit, the inductor compensation circuit is enabled, the velocity command of the VCM is adjusted, and a control signal is generated and applied to the voice coil in order to move the actuator arm, wherein the control signal is generated in response to the adjusted velocity command, the voice coil voltage, and the estimated inductance voltage.

Abstract: A data storage device comprising a transducer that includes a sensor array comprising multiple read sensors in a down track direction. A first pair of sensors in the sensor array reads data from a track, and at least one read sensor reads noise from an adjacent track.

Abstract: A hard disc drive (HDD) of a larger native capacity is clipped to emulate a smaller capacity drive by allocating storage space in tracks in at least both a radially innermost region and radially outermost region of the platter(s). During normal operation, when data is written to or read from the clipped HDD, the actuator arm will move through its entire, normal range of motion, as the read/write heads seek tracks in both the radially inner and outer regions of the platter(s). In some embodiments, storage space is also allocated from tracks in regions interposed between the inner and outer regions. In one embodiment, all tracks on the platter(s) are divided into regions of substantially equal data storage capacity, and the storage space is allocated for the clipped HDD is divided substantially evenly across all the regions.

Abstract: Systems and techniques relating to storage devices, such as storage devices that employ Shingled Magnetic Recording (SMR), can include a device, which includes: circuitry configured to write stored data and parity data to discrete portions of a Shingled Magnetic Recording (SMR) track in a SMR storage device; and circuitry configured to recover stored data for one of the discrete portions of the SMR track using the parity data and the stored data read from remaining ones of the discrete portions of the SMR track.

Abstract: A control system for a tape drive that uses position error signals (PESs) generated by a tape head assembly of the tape drive during longitudinal movement of a tape through the drive to dynamically adjust a lateral and/or angular position of tape to enhance tape drive performance (e.g., the ability of a tape head assembly to precisely follow one or more data and/or servo tracks on the tape). In one arrangement, the PESs and/or PES metrics are used as feedback into the system to steer the tape by moving one or more tape path guides until subsequently generated PESs or PES metrics have been optimized or have at least moved back into an acceptable range or to acceptable levels. The disclosed control system facilitates achieving increased stringencies on PES minimization that come with increased tape drive magnetic track densities.

Abstract: Provided are a method, system, and program for adjusting tension in a tape media to counter tape dimensional stability (TDS) errors in a tape media. A determination is made of whether to adjust tension of the tape media based on a detected error rate of reading at least one of the tracks. The tension of the tape media is adjusted in response to determining to adjust the tension.

Abstract: Methods and apparatus for vibration cancellation are disclosed. Vibration data from one or more vibration detectors associated with a storage device is collected. The vibration data represents vibrations experienced by the storage device. In response to the vibration data from the one or more vibration detectors, one or more movements for respective ones of one or more counter-vibration actuators to at least partially cancel of the vibrations experienced by the storage device is calculated. The one or more counter-vibration actuators perform the one or more movements.

Abstract: Systems and method relating generally to data processing, and more particularly to systems and methods for tone reduction in relation to data transmission. In one case, a data processing system is disclosed that includes: a two stage tone reduction circuit including a first stage circuit and a second stage circuit; and a polarity change circuit operable to change a polarity of the second stage output to yield a tone reduction output.

Abstract: A method for writing data to a tape storage medium includes: writing first user data to a first physical region (11) of the tape storage medium (1) in a first write mode, writing second user data to a second physical region (12) of the tape storage medium (1) in a second write mode, wherein the second write mode differs from the first write mode. An apparatus for writing data to a tape storage medium, a tape storage medium, a tape cartridge are also provided.

Abstract: Methods are provided for determining the heater power level of a dynamic flying height (DFH) type write head at which a touch down (TD) occurs. Each method makes use of the DC component of a head-disk interference (HDI) sensor and the determination of the TD heater energy is deduced from certain characteristics of the function relating heater power to HDI DC signal strength. Characteristics that provide reliable indication of a TD include points of minimum slope, structure of the slope's slope and the properties of a linear fit to the slope if the slope does not converge to a consistent value. It is found that the use of all methods in combination allow a reliable TD determination under virtually all conditions.

Abstract: A data storage device is disclosed comprising a disk, a head comprising a laser configured to heat the disk while writing data to the disk, and a fly height actuator (FHA) configured to actuate the head vertically over the disk based on an FHA setting. A write laser power applied to the laser during a write operation is calibrated, a first fly height of the head is measured at a first laser power setting, and a second fly height of the head is measured at a second laser power setting different from the first laser power setting. A FHA write setting is generated based on the calibrated write laser power and the first and second fly height measurements, where the FHA write setting is applied to the FHA during the write operation.

Abstract: Technologies are described herein for cancelling adjacent track interference in a storage device using an ITI predictor determined from predetermined data patterns in adjacent tracks. A first signal is read from a first portion of a data track, the first portion containing a first predetermined data pattern. Next, a value for an inter-track interference predictor associated with an adjacent track is determined based on the first signal, the first predetermined data pattern, and a second predetermined data pattern contained in a corresponding portion of the adjacent track. A second signal is read from a second portion of the data track, and inter-track interference from the adjacent track in the second signal is cancelled utilizing the value for the inter-track interference predictor.

Abstract: Migration of data in a data storage device (DSD). A spindle motor of the DSD is controlled to rotate a disk of the DSD to perform at least one operation on the disk and an operational activity level is determined for performing the at least one operation. It is determined whether the operational activity level is greater than a target level, and if it is determined that the operational activity level is not greater than the target level, data is transferred between a solid state memory of the DSD and the disk while the disk rotates.

Abstract: Systems, methods, devices, circuits for data processing, and more particularly to systems and methods for reducing inter-track interference in relation to processing data retrieved from a storage medium.

Abstract: A disk drive is disclosed comprising a head actuated over a disk, a spindle motor operable to rotate the disk, and a ramp near an outer periphery of the disk. When an emergency condition is detected, the head is unloaded onto the ramp, and failure analysis data identifying a cause of the emergency condition is logged.

Abstract: A disk drive is disclosed comprising a head actuated over a disk, and a dynamic fly height (DFH) actuator operable to control a fly height of the head over the disk. A DFH control signal is applied to the DFH actuator to decrease the fly height of the head, wherein the DFH control signal comprises a DC component and an AC component comprising an excitation frequency. A touchdown metric is measured over an interval, and the head contacting the disk is detected in response to a frequency component of the touchdown metric at the excitation frequency.

Abstract: A disk drive is disclosed comprising a servo control system configured to control an actuator for actuating a head over a disk. Servo sectors are sampled at a servo sample frequency fs to generate a position error signal PES(k) that is filtered with a compensator to generate a first control signal u1(k). A first discrete-time sinusoid comprising a sinusoid frequency of fs+?f is added to the first control signal u1(k) to generate a second control signal u2(k). The second control signal u2(k) is applied to the actuator, and a frequency response of the actuator is determined at the frequency |?f|. The frequency response of the actuator is determined at the frequency fs+?f based at least in part on the frequency response of the actuator at the frequency |?f| and a measured signal of the servo control system when applying the second control signal u2(k) to the actuator.

Abstract: A tape drive receives multiple write requests for data pieces and a synchronization request corresponding to the write requests from a device, performs a synchronization process, and returns a completion status of the synchronization request. The tape drive includes a write controller that stores data pieces transferred from the device in the buffer, according to a first write request, receives a first synchronization request and then a subsequent write request for at least one data piece, and returns the completion status when processing for the first synchronization request is completed and the subsequent write request is received with a command queuing function.

Abstract: A library device in which, even if the relation between the number of pulses of a stepping motor and an encoder count number changes, a movement distance of a medium transfer means can be verified by an encoder count number counted by an encoder sensor is provided. A control means (2) determines a proof factor used when calculating an assumed encoder count number assumed based on the number of pulses according to a movement distance of a medium transfer means (5). When a movement distance of the medium transfer means (5) is verified, an assumed encoder count number, which is assumed based on the above-mentioned determined proof factor and the number of pulses according to the movement distance of the medium transfer means (5), and an actual encoder count number, which is counted by an encoder sensor when a stepping motor is driven by the number of pulses according to the movement distance of medium transfer means (5), are compared.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of servo tracks, wherein each servo track comprises a plurality of servo sectors. A plurality of zones are defined, wherein each zone comprises a plurality of the servo tracks. A metric is generated for each zone, and when the metric for a first zone exceeds a first threshold, feedback compensation values for at least two servo tracks are generated, wherein the feedback compensation values compensate for a written-in error of the servo sectors of each servo track. When the metric for a second zone does not exceed the first threshold, generating feedback compensation values for the second zone is skipped.

Abstract: Approaches for an emergency power off (EPO) power island, for saving critical data to non-volatile memory in the event of an EPO condition, for use in a hard-disk drive (HDD) storage device. The EPO power island includes a controller for detecting an EPO condition. A voltage regulator supplies power from spindle motor back EMF only to the EPO power island and to the non-volatile memory. Thus, the remainder of the hard drive controller (HDC) is isolated from the EPO power island so that it will not corrupt the data as the HDC's power supply is decaying. Using the power provided by the voltage regulator, the EPO power island transfers critical data from a memory internal to the island to a non-volatile memory external to the island, such as to a flash memory chip.

Abstract: A system or device that has a storage media and a storage controller configured to non-statically allocate a media scratch pad to one of a plurality of storage locations on the storage media. The plurality of storage locations may be, for example, on a disc surface, or on multiple disc surfaces.

Abstract: A data storage system having a read channel configured to function in a normal operation mode and a test mode. In the normal operation mode, the read channel is configured to decode a readback signal to obtain data bits. In the test mode, the read channel is configured to extract gain control loop data and/or timing control loop data from the readback signal.

Abstract: According to one embodiment, a disk storage apparatus includes a disk, a detector, and a controller. The disk includes a first recording area for recording with a first track density, and a second recording area for recording with a second track density lower than the first track density. The detector is configured to detect a variation of an outside environment. The controller is configured to select a nonvolatile memory or the second recording area as a storage destination of write data transferred from a host, based on a content of the variation of the outside environment detected by the detector, and a state of capability or incapability of storage of the nonvolatile memory.

Abstract: A data storage assembly for cold storage. The data storage assembly includes a circuit board and a plurality of hard disk assemblies (HDA). Each HDA includes a platter and a head assembly to read and write data on the platter. The circuit board includes a processor and a memory. The processor acts as a hard disk controller for the plurality of HDAs and controls the platters. The processor further manages which HDAs are active at a time and the memory is shared by the plurality of HDAs.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. For example, a data processing system is disclosed that includes a combination data decoder circuit. The combination data decoder circuit includes: a non-binary data decoder circuit and a binary data decoder circuit.

Abstract: A disk drive is disclosed comprising a voice coil motor (VCM) configured to actuate a head over a disk. The VCM is controlled to seek the head over the disk during a first seek, and a back electromotive force (BEMF) voltage generated by the VCM during the first seek is measured. Feed-forward compensation is generated based on the measured BEMF voltage, and the VCM is controlled to seek the head over the disk during a second seek using the feed-forward compensation while writing servo data to the disk.

Abstract: A data storage system and associated method of use may generally be directed to a memory cache that stores a plurality of pending read and write requests. A processor can be configured to prioritize the read requests in the memory cache in response to a sensed acoustic or mechanical vibration in a data storage medium.

Abstract: A hard disk drive assembly (HDA) operable with a host computer that comprises a printed circuit board assembly (PCBA) including a system on a chip (SOC). The HDA including a plurality of disks configured to store data, a plurality of heads configured to read and write data stored on the plurality of disks, a flex circuit board including a preamplifier, and configured to couple to the plurality of heads and the SOC, a flex circuit cable coupled to the flex circuit board, and a non-volatile semiconductor memory (NVSM) located in the HDA. The NVSM is configured to store configuration data for read and write operations of the HDA, wherein the configuration data is to be retrieved by the SOC for controlling the read and write operations of the HDA, and the NVSM is coupled to at least one of the flex circuit cable, the flex circuit board, or the preamplifier.

Abstract: A contact detection system includes a comparator operable to compare a signal derived from a contact sensor with a threshold and to indicate contact when the signal is greater than the threshold, a parameter estimation circuit operable to estimate parameters of a probability density function based on the signal derived from the contact sensor, and a threshold calculator operable to calculate the threshold based at least in part on the parameters of the probability density function.

Abstract: A magnetic head is arranged between two reels around which a magnetic tape is wound and contacts one side of the magnetic tape spanned between the two reels. A driver moves the magnetic head. A controller causes the driver to generate a driving force for pressing the magnetic head against the one side of the magnetic tape while keeping the magnetic head in contact with the magnetic tape. It is possible to cause the magnetic head to stably contact the magnetic tape even when the running position of the magnetic tape varies in accordance with the winding state of the magnetic tape around the reel.

Abstract: Technologies are described herein for adaptive write pole tip protrusion compensation in a storage device having magnetic recording media. Variations in temperature of a head of a storage device are measured for various combinations of values of write-channel parameters during multiple test writes to the recording media. Sensitivity of the head temperature to change in value of the write-channel parameters is determined from the temperature measurements. A ratio of change in write pole tip protrusion of the head to change in head temperature is also determined. From the sensitivity of the head temperature to change in value of the write-channel parameters and the ratio of change in write pole tip protrusion of the head to change in head temperature, a coefficient corresponding to each write-channel parameter is calculated for the head to be utilized in a write pole tip protrusion compensation mechanism of the storage device.

Abstract: A disk drive is disclosed comprising a disk comprising servo data, and a head actuated over the disk. An offset r0 representing a difference between an axial rotation of the disk and an axial rotation of the servo data is estimated, and radial dependent timing compensation values are generated in response to the estimated r0. A phase error is generated in response to the servo data, and a control signal is generated in response to the phase error and the radial dependent timing compensation values. A frequency of an oscillator is adjusted in response to the control signal.

Abstract: In one embodiment, a system for integrating data and header protection in tape recording includes a processor and logic adapted to: provide a data array organized in rows and columns, each row of the data array including four interleaved C1 codewords (CWI-4), add a header to each row of the data array, each header including a CWI-4 Designation (CWID) which indicates a location of the CWI-4 within the data array, calculate ECC parity for at least one C1 codeword in each of the headerized rows, and modify the headerized rows to include the ECC parity, wherein each modified row includes four interleaved codewords, at least one codeword being a C1? codeword which includes ECC parity for a data portion of a C1 codeword and a portion of a header, wherein none of the CWIDs are split across multiple C1? codewords in a single modified row.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of spiral tracks, wherein each spiral track comprising a high frequency signal interrupted at a predetermined interval by a sync mark. An offset r0 representing a difference between an axial rotation of the disk and an axial rotation of the spiral tracks is estimated. Radial dependent timing compensation values are generated in response to the estimated r0. A phase error is generated in response to the sync marks in the spiral track crossings. A control signal is generated in response to the phase error and the radial dependent timing compensation values, and a frequency of an oscillator is adjusted in response to the control signal.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. For example, a data processing system is discussed that includes: an equalizer circuit, a signal to noise ratio calculation circuit, and a parameter adjustment circuit. The equalizer circuit is operable to equalize a data input to yield an equalized output. The signal to noise ratio calculation circuit is operable to calculate a signal to noise ratio of the equalized output based at least in part on a noise power derived from the equalized output. The parameter adjustment circuit is operable to adjust a parameter based at least in part on the signal to noise ratio.

Abstract: A method for inhibiting cycle slip in a tape drive having at least three channels that each utilizes a corresponding numerically controlled oscillator includes establishing a reference clock that is based on an output of the numerically controlled oscillators for at least two of the channels, comparing the output of the numerically controlled oscillator for one of the three channels with the reference clock to determine a first channel phase delta value for the one channel, and generating an error signal for the one channel if the channel phase delta value exceeds a threshold phase delta value for the one channel.

Abstract: A disk drive is disclosed comprising a head actuated over a disk, and control circuitry including a vibration sensor. A position error signal (PES) is generated representing a radial location of the head over the disk, and the head is servoed radially over the disk in response to the PES. A first vibration signal is generated in response to the vibration sensor, and a second vibration signal in response to the PES. The first vibration signal is combined with the second vibration signal to generate a third vibration signal, and a vibration event is detected in response to the third vibration signal.

Abstract: A disk drive is disclosed comprising a disk, a head comprising a laser operable to heat the disk while writing data to the disk, and a fly height actuator (FHA) operable to actuate the head vertically over the disk. A laser power applied to the laser during a write operation is calibrated, and a FHA write setting is generated for the FHA as a function of the calibrated laser power.

Abstract: Systems and methods for reducing problems and disadvantages associated with protecting data during cold excursions are provided. A method for preventing unreliable data operations at cold temperatures may include determining whether a first internal temperature of a hard disk drive (HDD) is below a threshold temperature. The method may also include initiating an artificial seek operation if the first internal temperature is below the threshold temperature.

Abstract: Various embodiments provide a recording medium. The recording medium may include a dedicated servo layer for providing servo information. The dedicated servo layer may include a plurality of tracks. A first track may include a first servo signal. A second track may include a second servo signal. The first servo signal and the second servo signal may include a plurality of common transitions. The transitions may be provided at a pre-determined frequency.

Abstract: A magnetic recording system configured for recording to a bit patterned media using both hypertrack recording and shingled recording. The magnetic recording system includes a write pole with a notched trailing edge that results in a write bubble with a trailing edge that has two outer convex lobes separated by a centrally disposed concave region. By locating one of the lobes over first and second data tracks of a hypertrack, a proper alignment of the relative phase of the two tracks can be maintained. Further adjustment to the alignment can be achieved by adjusting the radial location of the write head.