Abstract: A method of managing defects of a recording medium of a data storage device includes performing a quality test related to occurrence of errors for each data sector in the recording medium; classifying a quality of each data sector according to evaluation criteria corresponding to quality classifications based on the quality test; determining a number of data sectors in each quality classification; and defect-processing the data sectors of the quality classifications that range from a lowest quality classification to a highest quality classification within a defect management limitation of the data storage device.

Abstract: A method of adjusting gain of a variable gain amplifier of a read/write channel circuit includes loading a first VGA gain value that is read channel optimized, in a first register, loading a second VGA gain value that is adapted, in a second register, calculating a third VGA gain value according to a result of operation of the first VGA gain value and the second VGA gain value, and overwriting the third VGA gain value to the first register.

Abstract: An electronic device includes a power supply line connected between a DC power supply and an integrated circuit, and a first electronic element and a second electronic element serially connected between the power supply line and ground. The second electronic element is open when the first electronic element is short-circuited due to an overvoltage induced in the power supply line. When the overvoltage exceeds a breakdown voltage of the first electronic element, the first electronic element supplies an overcurrent induced in the power supply line to the second electronic element.

Abstract: A method of writing a servo pattern of a hard disk drive includes measuring the speed of a head of the hard disk drive by reading a basic servo pattern written to only select ones of the data tracks of the disk, realizing a feedforward current profile when the difference between the actual speed of the head and a target speed of the head is within a predetermined range, and writing a reference servo pattern using the realized feedforward current profile. A final servo pattern is then written using the reference servo pattern.

Abstract: Disc drive data recovery methods and systems that utilize off center track information are provided. A disc drive data track is illustratively read at a first position along a width of the data track and at a second position along the width of the data track. The data read from the track is stored and tagged with indications of the first and the second positions. The tagged data is optionally used to calculate average waveforms for each of the first and the second positions and to identify the average waveform having the highest signal-to-noise ratio.

Abstract: According to one embodiment, a magnetic recording tape includes a plurality of servo tracks, each servo track comprising a series of magnetically defined bars having an average height of between about 80 microns and about 120 microns, wherein an average stripe angle of the bars is between about 10° and about 25°. A stripe angle is measured between a longitudinal axis of each respective bar and a line oriented perpendicular to a direction of tape travel and parallel to a plane of the tape, wherein an average stripe width of the bars is between about 1.0 micron and about 2.2 microns and an average servo frame length of groups of the bars comprising a servo frame is between about 120 microns and about 180 microns. In more embodiments, a servo format and a system including a servo format are disclosed, along with other embodiments of magnetic tapes.

Abstract: A burst included in a burst pattern of a magnetic recording medium is a rectangular region. The rectangular region is constituted by a first signal region formed across a plurality of data tracks and is of a shape in which the length in the down track direction gradually increases in the cross track direction, and a second signal region adjacent to the first signal region in the down track direction. The maximum length of the first signal region is an edge of the rectangular region.

Abstract: Various embodiments of the present invention provide systems and methods for locating a reference pattern on a storage medium. For example, various embodiments of the present invention provide systems for locating a reference pattern on a storage medium. Such systems include a sliding window phase calculator circuit, a delay circuit and a mark detector circuit.

Abstract: According to one embodiment, A system includes a first LSI, a second LSI, a controller and a current monitoring and determination module. The first LSI operates on a first power supply voltage generated by a first voltage regulator included in the second LSI. The module operates on a device power supply voltage supplied from the device power supply. The module monitors current flowing between the first LSI and the first voltage regulator, determines an abnormality in the first LSI on the basis of the current monitoring result and transmits an abnormality signal to the controller on the basis of the abnormality determination result. The controller operates on a second power supply voltage generated by a second voltage regulator included in the second LSI and reports an abnormality in the first LSI to a host system in accordance with the reception of the abnormality signal.

Abstract: A disk drive including a sensor element that senses contact between a head slider and a disk, a head integrated circuit (IC) comprising an amplification circuit section that amplifies a signal of the head slider, a controller IC comprising a controller that accesses a register of the head IC for controlling the head IC, and an identification section, within the head IC, that determines a contact frequency of the contact by the sensor element by using a timing control signal of the controller IC.

Abstract: A method for using magnetic tape having damaged areas is disclosed. The method may include writing data to streaming magnetic tape, determining if the data write was successful, and responding to an unsuccessful data write by interrupting the data writing and advancing the magnetic tape forward a predetermined distance. Additionally, the method may include attempting to write data at the next location on the magnetic tape and determining if the data write was successful. The method may further include repeating the steps of advancing the tape, attempting to write, and determining whether the data write was successful following any determination that an attempted data write was not successful. The method may include further include resuming writing data to streaming magnetic tape at a location where a data write is determined to be successful.

Abstract: A system for removing low frequency disturbance signals from a control system output. The system includes a controller, a mixer, a feedback loop, and a low pass filter. The controller generates a control signal. The mixer is connected to the controller and receives the control signal from the controller. The feedback loop connects an output of said mixer to an input of the mixer. A low pass filter in the feedback loop allows low frequency disturbance signals in the control signal output from the mixer to pass through the feedback loop and to be added to the control signal by said mixer for handling by the controller.

Abstract: A method of timing control for servo-data detection in a disk drive. The method includes retrieving a plurality of servo sectors arranged discretely in a circumferential direction of a disk and measuring time intervals between servo sectors. The method also includes determining in which zone of a plurality of preset zones each of the measured time intervals is included. Moreover, the method also includes determining variations in time intervals from the zones of a plurality of previous time intervals, and modifying timing for servo-sector detection if variations in time intervals are within a preset range.

Abstract: A method includes writing data to a bit-patterned media at times determined by a clock having a period that is offset from a bit island period by a fixed offset to create one insertion or one deletion approximately within a predetermined number of bit islands, reading the data, and correcting the read data using error correction. An apparatus that implements the method is also provided.

Abstract: According to one embodiment, a magnetic recording apparatus includes: an information recording module configured to record a predetermined number of lines of information with a predetermined length in an information recording region of a magnetic recording medium, each of the lines of information having a same recording start position with respect to a relative movement direction of the magnetic recording medium and a recording element, the each of the lines of information being provided with an overlaying portion of adjacent lines of information. The information recording module is configured to record clock information in one or a plurality of the lines of information.

Abstract: A method for dividing a data area on a disk into a plurality of concentric zones and determining a format for each zone so that data tracks in the zone have the same number of data sectors. The method includes dividing a data area into a plurality of zones with provisional boundaries. The method also includes determining a linear recording density for a selected zone. The method further includes selecting the number of data sectors per data track corresponding to the determined linear recording density from specified values. Moreover, the method includes resetting a boundary of the zone at a new boundary shifted from the provisional boundary according to a selected value.

Abstract: An interleave address generation circuit includes a plurality of linear feedback shift registers operable to generate addresses for permuting a data block in a first domain to a data block in a second domain on a subword basis. The interleave address generation circuit is operable to generate the lane addresses for each subword and the linear feedback registers configured to generate circulant addresses and sub-circulant address to map bits in each subword in the data block in the first domain to a corresponding subword in the second domain.

Abstract: A system and method involving a read channel pipeline having a plurality of vector sequencers that may be used to control the processing blocks. In one embodiment, a read channel pipeline may include processing blocks that may be controlled a command word provided by vector sequencers. Incoming data may be delineated by identifying an early period, a steady-state period, and a trailing period. Instead of controlling these blocks with a static state machine controller, a plurality of vector sequencers are coupled to the plurality of processing blocks. Thus, a first vector sequencer may control the processing blocks during the early period and the steady state period, but then hand off control to a second vector sequencer for the trailing period. Using vector sequencers for implementing command words allows for greater programming flexibility once the device has been manufactured and deployed for use.

Abstract: A novel magnetic recording medium is disclosed in which a plurality of magnetic data recording layers and navigation layers are separate from one another. By decoupling the navigation and data layers, data may be written to data layers without the need to align the written data along servo tracks. Thus, the data layers may be configured for high recording density. Beneficially, imperfections within the magnetic data layers may also be compensated for by the use of adaptive error correction schemes which vary the encoding/decoding of data during writing/reading based upon the local quality of the recording media.

Abstract: An original stream file and an after-recording data file are managed as different files. In the original stream file, data is made up of sets of partial data (CU) divided in accordance with a predetermined interval. Likewise, in the after-recording data file, data is made up of sets of partial data (CA) divided in accordance with a predetermined interval. These sets of data are recorded onto a disc such that the after-recorded data (CA) is recorded in a region adjacent to a relevant original stream (CU). This allows reproduction and real-time after-recording with the use of a general MPEG-2 PS/TS decoder. Moreover, this allows realization of data recording that causes less interruption of reproduction when non-destructive editing is carried out with respect to an after-recorded result.

Abstract: In one general embodiment, a recording system controller includes a controller controlling a timing of flux switching of adjacent pairs of writers such that the writers in a given pair do not switch substantially concurrently, and reducing a current of one of the writers in the pair while the adjacent writer is writing a transition. In another general embodiment, a recording system controller includes a controller controlling a timing of pulse writing of adjacent pairs of writers such that the writers in a given pair do not pulse substantially concurrently. In yet another general embodiment, a method includes controlling a timing of pulse writing or flux switching of adjacent pairs of writers such that the writers in a given pair do not pulse or switch substantially concurrently.

Abstract: A computer system, a disk storage device and a method of controlling the same reads data by a reading size from a disk storage unit in which the data is stored according to a request of an application for reading data. The data is divided from the reading size into a size allocated by the application and stored in a memory region which the application accesses.

Abstract: Data storage systems are provided. Data storage systems illustratively include a recording head having a writing element and a bit patterned medium having a plurality of media dots. In some embodiments, the plurality of media dots pass the recording head at a media dot frequency. In some embodiments, the writing element writes data to the bit patterned media at a writing frequency that is less than the media dot frequency.

Abstract: Approaches for estimating the operating radius of a head in a hard-disk drive. These approaches may be used in a constant or approximately constant density servo scheme. Statistics, which describe the proportion of high frequency values to low frequency values in a readback signal read by the read/write head of a persistent storage medium, such as a hard-disk drive (HDD), are maintained. An estimated location for the read/write head using the statistics is determined. The estimated location may be expressed as an estimated operating radius, which is an estimated distance from the center of the magnetic-recording medium to a current position of the read/write head. Based on the estimated location of the read/write head, an estimated clock frequency for a readback channel to use in reading the servo data stored on the magnetic recording medium is determined. The readback channel reads the servo data using the estimated clock frequency.

Abstract: A method of operating a pre-amplifier of a hard disk drive is provided. The method includes generating a comparison signal corresponding to a result of comparing a reference signal with a difference between differential signals corresponding to write data, and controlling transmission of the differential signals to a write head in response to the comparison signal.

Abstract: A timing detector adapted for timing recovery on a read-channel is disclosed to improve signal quality of an input signal and maintain a small loop latency. The timing detector selects bits within the input signal that are high quality for timing recovery and discards bits that are low quality. The selected bits are used to synchronize phase and frequency of a bit sampler with a read-back analog signal. High-pass and low-pass analysis filters may split the input signal into high-frequency and low-frequency sub-bands and equalizers may re-shape the sub-bands. High-pass and low-pass synthesis filters may construct an output signal from the high-frequency and low-frequency sub-bands. Scaling factors may correct for signal and disturbance variations in the sub-bands. A comparator may eliminate sampled bits within the detector signal that have a magnitude less than a threshold and assign a common magnitude to sampled bits that meet or exceed the threshold.

Abstract: Patterned-media magnetic recording disks are made from a master template that has nondata regions that contain a pattern of one or more discrete nondata islands and discrete gaps, with the pattern representing a scrambled number. All disks made from the master template, or from replica molds made from the master, will have the same patterns. When the disks are DC-magnetized so that all the nondata islands are magnetized in the same direction, these patterns will include one or more of discrete magnetized nondata islands and discrete nonmagnetic gaps that are scrambled in a pseudo-random manner. During operation of the disk drive the patterns are detected by the read head and interpreted within the disk drive using knowledge of the pseudo-random scrambling function, so that reading and writing of data can occur in the conventional manner. If the disks are copied in an attempt to replicate the master template, the resulting disks will be inoperable in a disk drive because of the scrambling.

Abstract: Various embodiments of the present invention provide systems and methods for signal offset cancellation. For example, a method for error cancellation is disclosed. The method includes: receiving an input signal that includes a second order error component; applying a transfer function to the processed input to reduce the second order error component; and providing an output signal that is the result of applying the transfer function to the input signal.

Abstract: A method and apparatus is presented to determine a lateral position of a read/write head relative to a sequential information storage medium having a servo signal encoded therein and moving adjacent to the read/write head, where the servo signal comprises a plurality of pulses. The method includes detecting the servo signal using the read/write head and calculating a timing interval between each of the pulses using a clock rate of a clock signal. The clock rate is then adjusted based upon the velocity of the sequential information storage medium.

Abstract: To effectively suppress a signal in a low frequency region in which the medium noise and the signal distortion are concentrated, and in order to effectively utilize a detected component of the reproduced signal in the low frequency region, a target of partial response equalization to the perpendicularly recorded/reproduced signal is set so that the low-frequency component around the direct current is suppressed to a regulated quantity for both the effective suppression and the effective utilization. Accordingly, a maximum-likelihood decoding process is carried out through the target of partial response equalization. Reliability of data detection is made higher and a signal-to-noise ratio is improved, so that the noise from the recording medium can be reduced more and it is possible to provide a high-density magnetic recording/reproducing apparatus.

Abstract: According to one embodiment, a disk drive is provided, which starts reading data at the head thereof, when a sync mark is detected. The disk drive has a read channel that generates a forced SM detection signal if the sync mark cannot be detected because of the occurrence of TA. The read channel starts generating the forced SM detection signal at the end position of a preamble, which is equivalent to the position of the sync mark.

Abstract: A weighted combining scheme exploits information from two servo channels operating in parallel. A timing-based servo module comprises two synchronous servo channels coupled respectively to receive two digital servo signals read from a data tape. Both channels have outputs for an unweighted parameter estimate and for a measure of the channel reliability. A weight computation module provides first and second weight signals using the measures of channel reliability from the servo channels. An offset computation module provides first and second offset terms which are summed with the unweighted parameter estimates. Multiplying nodes receive the unweighted parameter estimates and the weight signals and outputs offset weighted parameter estimates. A summing node receives the offset weighted parameter estimates and outputs a combined offset weighted parameter estimate to a servomechanism.

Abstract: According to one embodiment, a magnetic disk storage device includes a magnetic disk, a head, a clock generator, an estimating module, and a controller. The magnetic disk includes a servo area and a corresponding data area, and has a surface divided into zones in the radial direction. The basic frequency varies in the servo area depending on the zones. The head is driven to read a signal from the magnetic disk. The clock generator generates a clock signal for decoding a signal read from the data area corresponding to the servo area based on a signal read from the servo area. The estimating module estimates the position of the servo area in the radial direction, from which the head reads a signal next. The controller controls the clock generator to generate a clock signal of the basic frequency before the head reaches the servo area based on the estimated position.

Abstract: A magnetic device includes a read sensor, a writer and a synchronization sensor. The magnetic device is configured for writing information to and reading information from a magnetic medium that includes a plurality of discrete magnetic bits. The writer includes a write element, a first return element magnetically coupled to the write element, and a second return element magnetically coupled to the write element. The write element is positioned in between the first and second return elements. The synchronization sensor is located adjacent to the write element of the writer in a closely spaced arrangement, and is configured to generate a signal as a function of a sensed magnetic bit. The signal is used to position the writer element relative to the sensed magnetic bit.

Abstract: A magnetic disk controller includes a first buffer that includes a first storage area that stores former portions of pieces of writing data, and a second storage area that stores latter portions of pieces of writing data; an encoding unit that encodes a former portion of the first piece of writing data; a second buffer that stores the encoded former portion of the first piece of writing data; and a buffer control unit that writes the encoded former portion of the first piece of writing data into a first sector of the magnetic disk. The encoding unit encodes the latter portion of the first piece of writing data. The second buffer stores the encoded latter portion of the first piece of writing data. The buffer control unit, writes the encoded latter portion of the first piece of writing data into the first sector of the magnetic disk.

Abstract: A system for generating an output signal indicating a specific area on an optical disc is disclosed. The system includes: a detecting circuit, a header signal generator, a protection circuit, a counter and an output signal generator. The detecting circuit detects pre-recorded address information on the optical disc to generate a detection signal. The header signal generator detects headers on the optical disc to generate a header signal. The protection circuit computes a first counter value and reloads the first counter value according to the detection signal and the header signal, wherein the protection circuit does not reload the first counter value twice successively due to the header signal. The counter computes a second counter value and reloads the second counter value according to the first counter value. The output signal generator generates the output signal according to the first counter value.

Abstract: A method is disclosed for preserving data in a hard disk drive, in which data loss due to adjacent track erase (ATE) phenomenon can be minimized by relocating data, which is written in a zone where the ATE phenomenon is likely to occur since frequency of use is high, to another zone having a low TPI when writing the data in a disk.

Abstract: Various embodiments for writing data in a tape medium having wraps by a tape drive are provided. The tape drive allocates the wraps in a shingled data band between two or more data partitions. A set of contiguous wraps is allocated to one data partition of the two or more data partitions. An additional set of contiguous wraps is allocated to an additional data partition of the two or more data partitions. A minimum buffer is retained between the set and the additional set of contiguous wraps of at least one wrap per direction written within at least one data band shared between the one and the additional data partitions such that the one and the additional data partitions may be written to by the tape drive independently of each other.

Abstract: A controller for use in a disk drive includes a comparison signal generator for comparing a period of time when a write unsafe signal output from a pre-amplifier is activated with a reference period of time to generate a comparison signal; a write failure signal generator for generating a write failure signal according to a write gate signal and the comparison signal; and a logger for logging at least one of the period of time when a write unsafe signal output from a pre-amplifier is activated and the number of times of activations of the comparison signal.

Abstract: According to one embodiment, a write clock generator writes data to bits in a magnetic recording medium based on a write clock signal with a phase obtained by delaying the phase of a reference write clock signal. The write clock generator detects the amplitude of a read signal for the written data. The write clock generator repeats these operations with a phase delay varied. The write clock generator decides an optimum phase delay based on the amplitude detected for each phase delay.

Abstract: According to one embodiment, a disk drive comprising a magnetic disk of bit-patterned type is provided. The disk drive has a reproduction module, a measurement module, and a recording module. The reproduction module outputs a reproduced signal corresponding to the phase-shift measuring bits provided on the magnetic disk. The measurement module determines that the phase shift corresponding to the phase-shift measuring bits is the phase shift of a write clock signal if the reproduced signal is determined to be indefinite on the basis of the quantization value of the reproduced signal. The recording module records data corresponding to the data recording bits, by using the write clock signal adjusted by the phase shift.

Abstract: According to one embodiment, a magnetic storage device, includes: a verification processing detector configured to detect whether there are a plurality of operation commands corresponding to a first verifying operation, based on a plurality of sets of individual information about the operation commands for the magnetic storage device from an external device, the sets of individual information including execution times and sets of accessed address information, the sets of individual information being stored in a first storage module as history information; and a processing condition setting module configured to set processing conditions for a second verifying operation to verify data stored in the first storage module, based on the sets of individual information corresponding to the first verifying operation, when the operation commands are detected.

Abstract: According to one embodiment, a disk storage device includes: a controller configured to write data pieces stored in a buffer memory to a disk medium by a physical sector size which is an integer multiple of a unit logical block, wherein the controller is configured to detect at least one of the write data pieces stored in the buffer memory, the at least one of the write data pieces being to be written to a portion of a physical sector of the disk medium, configured to store the at least one of the write data pieces to the non-volatile memory, configured to store the rest of the write data pieces to the disk medium, and configured to write, upon non-detection of a command for a predetermined time period, the at least one of the write data pieces to the disk medium by the physical sector size through read-modify-write processing.

Abstract: Methods and apparatus for interleaving data in a multitrack tape drive and for writing data on a multitrack tape in the tape drive. One method includes: partitioning the data into m(2n+k) data blocks, where each data block has a logical array of rows and columns of data bytes; error-correction coding a row and a column of the logical array to produce an encoded block; assigning the coded row to a respective location in a logical interleave array having L rows and 2n+k columns of locations; and writing a sequence of assigned coded rows simultaneously in respective data tracks on the multitrack tape. The coded row is assigned such that the minimum Euclidean distance on the multitrack tape between the coded rows is maximized. The apparatus includes units for performing the methods and the computer program product includes a program code means for causing a computer to perform the methods.

Abstract: Various embodiments of the present invention provide systems and methods for detecting storage medium defects. As one example, a media defect detection system is disclosed that includes a data detector circuit that applies a detection algorithm to the data input and provides a hard output and a soft output. A first circuit combines a first derivative of the hard output with a derivative of the data input to yield a first combined signal. A second circuit combines a second derivative of the hard output with a derivative of the first combined signal to yield a second combined signal. A third circuit combines a derivative of the soft output with the second combined signal and a threshold value to yield a defect signal.

Abstract: An apparatus includes a disk arrangement, a first signal processing path configured to output data from the disk arrangement according to a first protocol, a second signal processing path configured to output data from the disk arrangement according to a second protocol, and an interface including a set of electrical conductors and a mode control unit. The mode control unit is configured to output data from the first signal processing path on the set of electrical conductors according to the first protocol and to output data from the second signal processing path on the set of electrical conductors according to the second protocol according to a control signal received by the mode control unit. The second protocol is different from the first protocol.

Abstract: An apparatus includes a waveguide having a core layer and an end adjacent to an air bearing surface, first and second poles magnetically coupled to each other and positioned on opposite sides of the waveguide, wherein the first pole includes a first portion spaced from the waveguide and a second portion extending from the first portion toward the air bearing surface, with the second portion being structured such that an end of the second portion is closer to the core layer of the waveguide than the first portion, and a heat sink positioned adjacent to the second portion of the first pole.

Abstract: A disk drive is disclosed comprising a disk and a head actuated over the disk. The disk comprises a plurality of tracks, wherein each track comprises a plurality of data sectors. A read command is received from a host to read data from a target data sector. When it is determined that the target data sector has not been written by the host, dummy data is returned to the host.

Abstract: A printed circuit cable assembly (PCCA) for a hard disk drive (HDD) is disclosed. The PCCA includes a stiffener portion having an elongated shape that includes an integrated circuit (IC) chip. The PCCA also includes a flexible portion extending from the elongated stiffener portion, wherein the PCCA is configured to be mountable on a headstack of the HDD such that an entire footprint of the IC chip overlays a metallic portion of the headstack of the HDD.

Abstract: Various embodiments of the present invention provide systems and methods for controlling access to a magnetic storage medium. As one example, a method for controlling access to a magnetic storage medium is disclosed that includes providing a location count indicating a location between a portion of a first servo data sector of a magnetic storage media and a portion of a second servo data sector of the magnetic storage media, and asserting an enable window signal based upon the location count.