Abstract: A slew-rate control device controls a slew rate of a control signal based on which data reading or data writing is performed with respect to a storage medium. A retry executing unit changes, when an error occurs during the data reading or the data writing, the slew rate of the control signal, and executes a retry of the data reading or the data writing. A slew-rate setting unit sets, as the slew rate of the control signal, a slew rate with which the retry is successfully executed.

Abstract: Spinstand test improvement that measures Functional Byte Error Rate (F-BER) of a disk. The F-BER is correlated to the BER of a disk. The F-BER test is faster than a BER test. The F-BER test is incorporated into a spinstand tester or the software associated with a spinstand tester.

Abstract: A rewrite determining unit acquires, for every servo frame recorded on a magnetic disk, an amplification degree, i.e., a gain of an amplifier circuit by which a read signal read from the magnetic disk is amplified to a predetermined output, determines a rewrite sector count based on the amplification degree, and performs data rewriting according to the rewrite sector count.

Abstract: Apparatus and method for rotating a data storage media having pre-formatted servo data tracks adjacent a data transfer member, and retrieving readback data with the data transfer member along a path that is non-concentric in relation to the servo data tracks. The data transfer member is controlled by a control circuit that is configured for retrieving readback data from different data storage tracks during less than one revolution of the media.

Abstract: In a data recovery processing, the conventional overhead, primarily, latency due to a rotational recording media is removed. Secondary, in a signal processing or in a recording and reproducing apparatus, reliability of data reproduction is improved by repeatedly processing data. These processing are achieved that input signal, i.e., raw analog signal read from the recording media is digitized to be stored in a secondary storage such as a memory or a FIFO memory. The apparatus includes a signal processing circuit to repeatedly process the stored digital signal in the secondary storage. When detecting data, operation of the circuit is efficiently controlled by a change over detector parameters, in which characteristics for the detecting performance. Resultantly, data recovery processing speed is increased and reliability of data reproduced is improved.

Abstract: A method and an apparatus to write and inspect servo information on a disc drive and minimize an effect on servo information written in adjacent tracks caused by a gap erase field, and write servo information on the disc drive and perform servo information inspection and defect processing. The method includes sequentially writing servo information toward a track having skew ‘0’ at from outer surface in an outer region of the disc, and sequentially writing the servo information toward the track having skew ‘0’ from an inner surface in an inner region, and after writing of the servo information is completed, inspecting the servo information written in a track at a predetermined distance from the track having skew ‘0’, and determining whether the servo information is correctly written.

Abstract: In a perpendicular magnetic recording system, the data that is being written by the write channel is fed back into the read channel. The read channel processes the data and decides if the written sequence is likely to have very poor DC characteristics. If that is the case, the write channel changes a scrambler seed and rewrites the data using the new scrambler seed. The data may also be inspected for patterns that might cause large baseline wander before being written to disk, i.e., in the write channel. A data sequence may be repeatedly scrambled and encoded until an acceptable level of estimated DC-wander has been achieved. The data sequence may then be written to disk.

Abstract: A magnetic recording disk drive has a patterned magnetic recording disk with data blocks of magnetizable material separated by nonmagnetic regions, a read head for reading the magnetized data blocks and generating a readback signal, and a timing circuitry that generates from the readback signal a series of timing pulses. When the read head is over a nonmagnetic region the readback signal is significantly reduced, and this signal reduction is detectable to determine the position of the nonmagnetic regions. The timing circuitry includes a rectifier that rectifies the readback signal, a highpass filter that filters the rectified signal at the frequency of the data blocks, and a peak detector that detects the peaks of the filtered signal and generates a series of timing pulses, each pulse representing a nonmagnetic region.

Abstract: In a magnetic tape storage including a nonvolatile buffer memory, the buffer memory memorizing sets of data sent from a host computer, a set of data including a pair of one file and one tape mark, the tape mark showing the end of the file, sets of data are continuously stored in the buffer memory until the total data amount of the sets of data comes up to a predetermined data amount, and the sets of data stored in the buffer memory are wrote to a magnetic tape (called flushing) when the total data amount of the sets of data in the buffer memory exceeds the predetermined data amount. The frequency of the flushing and tape reposition according to the flushing can be greatly decreased. The wear-out of the magnetic tape and mechanical section relating to the magnetic tape running in the storage can be reduced.

Abstract: A data reading unit reads inner offset data from an offset reading in an inner direction toward a center of a storage medium and outer offset data from an offset reading in an outer direction toward a circumference of the storage medium. A data comparing unit compares the inner offset data and the outer offset data read by the data reading unit. A data-output control unit that outputs the read-data when a result of comparison by the data comparing unit indicates that the inner offset data matches the outer offset data.

Abstract: A method of determining a head characteristic, i.e. determining whether a head has a write characteristic stronger or weaker than that of a normal write head, and a recording medium suitable to perform the method. The method includes detecting a first error rate by writing data and then reading the written data without control pole tip protrusion (PTP) contralto compensate for thermal pole tip protrusion (TPTP) in a state where the head is fully cooled, detecting a second error rate by writing data and then reading the written data with the PTP control in the state where the head is fully cooled, calculating a difference between the first error rate and the second error rate, and determining based on the calculated error rate difference whether the head is a strong write head having a stronger write characteristic than that of the normal write head or a weak write head having a weaker write characteristic than that of the normal write head.

Abstract: One embodiment of the present invention provides a system that dynamically controls a temperature profile within a disk drive by generating disk drive activity. During operation, the system first receives a desired temperature profile. Next, the system generates a load profile based on the desired temperature profile, wherein the load profile specifies read/write operations on the disk drive. The system then applies the load profile to the disk drive to generate disk drive activity, wherein the disk activity causes the temperature in the disk drive to track the desired temperature profile.

Abstract: Tape heads and controllers for controlling such heads in a tape drive are described. A controller may determine a first parameter corresponding to the similarity between data read by a first pair of read elements of a head, a second parameter corresponding to the similarity between data read by another pair of read elements having one read element in common with the first pair, and a position of the head with respect to a data track based upon a relationship between the first and second parameters. The controller may adjust the head to a proper lateral position based upon the determined position.

Abstract: Temporary lock-out is provided while programming a group of non-volatile memory cells to more accurately program the memory cells. After successfully verifying that the threshold voltage of a memory cell has reached the level for its intended state, it is possible that the threshold voltage will subsequently decrease to below the verify level during additional iterations of the programming process needed to complete programming of other memory cells of the group. Memory cells are monitored (e.g., after each iteration) to determine if they fall below the verify level after previously verifying that the target threshold voltage has been reached. Cells that pass verification and then subsequently fail verification can be subjected to further programming. For example, the bit line voltage for the memory cell of interest may be set to a moderately high voltage to slow down or reduce the amount of programming accomplished by each subsequent programming pulse.

Abstract: A method of determining defects on a media of an information storage device includes reading information representing data from a magnetized portion of the media, processing the read signal with discrete time signal processing, and detecting a phase shift in the read signal over a selected threshold. The method also includes sending an indication of a defect in the media in response to detecting the phase shift over the selected threshold, determining the location of the media of the defect, and storing the location of the defect in memory.

Abstract: Error correction in a disk drive is performed by identifying all errors in multiple sectors of a single track during a single read operation. As the data from the track is moved to a buffer, the disk drive records the location of the errors without stopping the read operation. Following the read operation, error recovery is performed on all errors identified in the track. If further error recovery is needed on the track, a subsequent read operation may then be performed.

Abstract: A helical-scan-type magnetic tape recording and reproducing apparatus includes: a helical-scan-type recording head that is movable, while being attached to a distal end of an actuator, in a track width direction by displacement of the actuator itself to sequentially scan a magnetic tape; a helical-scan-type reproducing head that is movable, while being attached to a distal end of an actuator, in the track width direction by displacement of the actuator itself to sequentially scan a track on the magnetic tape recorded by the recording head; an error rate profile forming mechanism forming, by wobbling the reproducing head at each of plural points on the track, error rate profiles at the plural points; and a reproducing-head moving mechanism moving the reproducing head at the plural points, by finding a point with the best error rate from each error rate profile at the plural points from the error rate profile forming mechanism.

Abstract: A method for estimating a rate of errors written to a magnetic media includes writing a selected number of signals representing information to a track on the magnetic media, and adjusting a programmable portion of an error correction code module for correcting a selected number of errors in a portion of data to a level where the track having the selected number of signals can be read and corrected. The method also includes correlating the level of the programmable portion of the error correction code module to the number of errors in the selected number of signals written to the track.

Abstract: To provide a recording control device able to control a data recording so as not to use a defective sector free from a sector test before a shipment thereof, which controls a data recording with respect to a plurality of sectors in a recording region of a recording medium and has: a verification unit writing data to be written to a first sector in the recording medium when receiving a write request to the recording medium, then reading out the data from the first sector, and performing a verification processing comparing the data to be written with the read out data; and a processing unit writing the data to be written to a second sector on condition that the verification unit decides that the comparison result is disagreement, and determining attribute data as a management data.

Abstract: In order to provide a control device for a storage and reproduction mechanism that can acquire a constant error rate without being affected by changes of atmospheric pressure, a control device comprises a storage medium for storing data, a head for conducting a storage/reproduction process of data on the storage medium, an error detection unit for detecting an error of the data read by the head, and a flying height control unit for controlling a flying height of the head in accordance with the error rate for correlating changes of the flying height due to the changes in the atmospheric pressure.

Abstract: The misplacement of a servo burst during a servowriting or self-servowriting process can be corrected by erasing and re-writing that burst. In addition, WORF information of a track can be saved in memory for future servowriting and/or can be utilized to compare with a pre-determined threshold to identify servo bursts to be repaired. Alternatively, a batch writing approach can be used to minimize the time needed to re-write misplaced bursts. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

Abstract: Method and apparatus are provided for presenting various levels of detail about successful error recoveries and background hardware optimizations during the recording and retrieval of digital information on magnetic tape. A first, Band Summary, report presents a high-level summary of recovery methods by data band and wrap. A second, Detail Summary, report presents a mid-level summary of recovery methods by track and longitudinal position (LPOS) region within one wrap of a band on the tape. A third, ERP Summary, report presents a low-level summary of errors and specific recovery methods and optimizations by LPOS region within each wrap. Such “telescoping” views permit pattern analysis to be performed at different resolutions. Thus, correlations of possible interactions between hardware and microcode activities that result in changes of the nominal operating point of the drive may be identified.

Abstract: A signal detector to detect symbols in a read back signal. The signal detector includes a first detector to generate raw decisions as a function of the read back signal. A post processor identifies possible defects in the raw decisions. A selector selects a portion of the possible defects and generates modified decisions based upon correcting the portion of the possible defects. At least one signal decoder generates final decisions as a function of the modified and raw decisions. A decision block returns control to the selector in response to detecting excess errors in the final decisions.

Abstract: The present invention has been made to obtain a magnetic disk apparatus and the like capable of using a patrol region in the magnetic disk to detect a location in need of maintenance in hardware equipment around the magnetic disk in a separate manner from the disk itself and thereby avoiding useless replacement and operating the magnetic disk apparatus at low cost. In a preventive maintenance detection for a magnetic disk apparatus having a patrol function that uses a patrol region in the magnetic disk to determine the presence/absence of the need of preventive maintenance, a data pattern for detecting crosstalk in hardware equipment around the disk is generated, a write command or read command corresponding to the generated data pattern is executed, and the crosstalk is determined/detected based on the command execution result.

Abstract: A substrate processing apparatus which enables parameters for carrying out processing on substrates to be changed easily by a user. A storage device stores parameters that are for controlling the processing and are categorized into a plurality of categories. A control device carries out the processing on the substrate based on the parameters. A parameter changing device enables each of the parameters to be changed in accordance with the category of that parameter. A parameter category changing device changes the category of some of the parameters. A category change defining device is detachable from the substrate processing apparatus and specifies parameters whose category is to be changed out of the parameters. The parameter category changing device changes the category of each of the parameters specified by the category change defining device.

Abstract: A nonlinearity measuring method capable of measuring NLTS with a higher precision while taking the state of magnetization inversion of a preceding bit string into consideration. A constitution includes a first measuring section measuring a first predetermined higher harmonic component from a regenerated signal of the reference signal magnetically recorded on a medium, a second measuring section measuring a second predetermined higher harmonic component from regenerated signals with respect to plural kinds of signals to be measured magnetically recorded on the medium, and a calculating section calculating NLTS from the first component and the second component corresponding to each of the signals, wherein each of plural kinds of signals to be measured includes a magnetization inversion pattern string P1 preceding the objective bit to be measured of NLTS; thereby NLTS depending on the string P1 can be quantitatively measured easily.

Abstract: A location within a cycle is determined by reading a portion of a cyclic bit sequence, the bit sequence containing several interspersed bit-group sets that each contain a plurality of series that each consist of several consecutively-placed identical bit-groups. On a data surface in a disc drive, each bit group can be stored and accessed in unused bits of each servo sector's digital portion.

Abstract: A method, apparatus and program storage device for providing protrusion feedback for a read/write element is disclosed. A slider with a heating element is provided to control the level of read/write element protrusion. A level of heating applied to the slider to change the head protrusion is measured and recorded until acceptable operation of the read/write element is obtained. These measurements are then used to ensure that the read/write element continues to operate properly at different drive temperatures.

Abstract: An information storage system has structure with a head that can effect information transfers with respect to a storage medium. According to one feature, a control portion monitors a characteristic of information read from the storage medium, and can take action to reduce the likelihood of non-recoverable errors based on the characteristic. According to a different feature, the control portion moves the head to a position adjacent a portion of a surface on the storage medium, waits while moving the head relative to the surface, and then moves the head to another position adjacent a different portion of the surface. According to another feature, the control portion calculates a distance of the head from the surface based on information read from the surface, and determines based on this distance whether the head or the storage medium may fail to satisfy a criteria.

Abstract: A method of recording data to an area including a defective ECC block of a DVD+RW, and an optical disk written in the recording method are provided. In the method, when data is recorded to an area including a defective ECC block, data recording ends at an ECC block right before the defective ECC block. Then, the data recording resumes from the last 8 channel bits of the ECC block immediately after the defective ECC block. Accordingly, recording/reproducing of data to/from an optical disk is consistently performed.

Abstract: A method for identifying victim tracks distanced from an aggressor track in a hard disk drive that are deleteriously affected by long range fringe effects causing adjacent track interference (ATI) when the aggressor track is written includes writing first and second frequencies to candidate victim tracks, and writing a third frequency to the aggressor track. The amplitudes of the remaining frequencies are read and output and if desired normalized as an indication of ATI to distant victim tracks. Or, data can be written and on-track error rates (OTER) used to determine ATI.

Abstract: A high-speed, wide bandwidth data detection circuit includes a phase detection module, a data detection module, a loop filter, and a voltage controlled oscillator. The phase detection module is operably coupled to produce a controlled current based on a current mode mathematical manipulation of differences between an incoming data stream and a recovered clock. The phase detection module performs the current mode mathematical manipulations and produces the controlled current in the current domain. The data detection module is operably coupled to produce the detected data based on the incoming data stream and the recovered clock. The loop filter is operably coupled to convert the controlled current into a controlled voltage. The voltage controlled oscillator is operably coupled to convert the control voltage into the recovered clock.

Abstract: A guarantee processing method guarantees the data of an adjacent track in the case of a write fault when there is a possibility of an off track write. Even if a write fault is detected or an offset read retry is successful, a rewrite for guaranteeing an adjacent track is not executed immediately. The possibility of an off track write is judged by the movement of the head, and only the sector which is difficult to read due to the off track write is rewritten.

Abstract: A system and method for performing read retry operations with respect to an erroneously read data sector is disclosed. The system and method use estimates of bit error rates determined during previous attempts to read data from the sector to determine an optimal distance and direction to move a read transducer for a subsequent read retry of the erroneously data sector.

Abstract: A method of writing product servo sectors to a disk of a disk drive is disclosed. A plurality of spiral tracks are written to the disk, wherein each spiral track comprises a high frequency signal interrupted at a predetermined interval by a sync mark. During the product servo writing process, the sync marks in the spiral tracks are detected and a sync mark reliability metric is generated, wherein the sync mark reliability metric represents a probability that the sync mark was detected accurately. A timing recovery measurement is generated in response to the detected sync marks and the sync mark reliability metrics. A servo write clock is synchronized in response to the timing recovery measurement and used to write the product servo sectors to the disk while serving on the spiral tracks.

Abstract: Disclosed is a servo writer when, detecting an abnormality from servo signals written on a tape-shaped recording medium, such as a magnetic tape, corrects the abnormality through a simplified procedure, thereby allowing for an increase in the transport speed of media in the future. The servo writer includes a write head for writing servo signals, a verifying head positioned downstream of the write head in a transport direction of the tape, for reading the servo signals written by the write head in order to inspect the servo signal, an inspection section for checking whether or not the servo signals being read by the verifying head contain any abnormality, and an overwrite head positioned downstream of the verifying head in the transport direction, for overwriting a portion where the abnormality is detected by the inspection section.

Abstract: As a tape recording format, tracks are formed by a succession of block units, and a data unit called a group is formed by data of size equivalent to a predetermined plurality of tracks. Using this format, a base group number indicating the group to which the current track physically belongs is recorded in the ID information for a track, and the lower four bits or similar of a group number indicating the group to which the current block logically belongs is recorded within a block. By this means, even if rewriting is performed in block units and a recorded state results in which the blocks of a plurality of groups are intermixed within a track, the group to which each block belongs can be correctly identified during reproduction.

Abstract: The thermal decay of data written to a magnetic mass storage medium is determined by measuring and analyzing the time-domain equalized-signal-to-noise ratio (ESNR) and equalized signal-to-total-distortion noise ratio (ESTDR) of written data. In some embodiments, a test track and a reference track are initialized from data. Subsequently, the reference track is re-initialized from the test data, and the time-domain ESNR and/or ESTDR measurements are made of the test track and the reference track, at predetermined time intervals. Later, the time-domain ESNR and ESTDR measurements are analyzed to determine the thermal decay of the data written. In another embodiment of the present invention, the ESNR and/or ESTDR measurements includes reading the data through a non-return-to-zero bus in phases, in which the phases are selected in sequence.

Abstract: A tape recording apparatus for recording data on a tape medium is provided with: a data writing unit for writing a data unit to the tape medium, and if an error is detected in the writing of the data unit, writing the same data unit to the tape medium again and recording a plurality of the data units sequentially; a write number counter for, in a data set including the plurality of data units, counting a write number which is a number of writing the data units; a write number information storage unit for storing write number information, in which information indicating the counted write number and a physical position in the tape medium are associated with each other, with respect to a plurality of the tape media to which the above described tape recording apparatus has written; and a failure determination unit for detecting a failure in the data writing unit based on the write number information.

Abstract: The present invention is a method or apparatus configured for analyzing a data storage device containing a transducer head positionable adjacent a data storage media surface. First, a defect is detected in a region of the surface. Two or more readback signals are obtained, each received during a respective pass of the transducer head adjacent the defective region. The signals are then combined to define a category for the defective region, either automatically or by visual examination of an image. Preferably, all of the read signals are received from the transducer head while the data storage device remains sealed in a substantially opaque chamber. That way, the media defects of an entire population of data storage devices can be analyzed quickly, disassembling the drives for direct visual analysis only on a selective basis.

Abstract: A storage channel, e.g., for a disk drive system, may asynchronously sample and buffer an entire sector, and then process the buffered sector to recover timing information. The storage channel may operate in an open-loop and utilize an exhaustive search to determine timing parameters. Alternatively, the storage channel may operative in a closed-loop, processing the sector once, and feeding back information obtained during decoding to the timing loop.

Abstract: The present invention provides a magnetic recording unit, including: a magnetic head; a magnetic recording medium having a servo pattern for adjusting a position of the magnetic head; a frequency detecting element for detecting a frequency in the servo pattern on a track corresponding to the position in a radial direction of the magnetic recording medium, on the basis of a reproduction signal obtained by reading the servo pattern with the magnetic head; a storage element for storing in advance information on predetermined frequencies corresponding to the positions of tracks of the magnetic recording medium; a tracking element for comparing the frequency detected on the track by the frequency detection element and the information on the frequency corresponding to the same track, the information being stored in the storage element, and for generating a signal for adjusting the position of the magnetic head, the signal being generated on the basis of a difference between the frequencies.

Abstract: In a coding method which does not restrict a run length of “1” while data is recorded/reproduced, there are such a drawback that when an error correction is carried out, a total number of error data to be corrected is increased, and also errors of not-detectable data are increased. While data is coded, a continuous number of “1” contained in a code word is limited, and then an error correction is carried out inside a coding/decoding process operation. Thus, a recording/reproducing apparatus having a small number of decoding errors is available.

Abstract: A servo writing system for writing servo sectors onto a disk includes a direct digital synthesizer (DDS) that forms a phase and frequency adjustable continuous wave signal based upon a reference digital clock signal. A PLL coupled to the DDS measures repeatable timing errors (RTEs) associated with the continuous wave signal and generates an output clock signal that is used to clock the writing of servo sectors onto the disk. A digital control system is coupled to the DDS and the PLL, which calculates repeatable error compensation adjustment values based on the RTEs measured using the PLL. The compensation adjustment values may be applied to the DDS such that the DDS compensates for the RTEs and such that the output clock signal used to clock the writing of the servo sectors onto the disk includes minimal RTEs.

Abstract: An apparatus and method write data to a storage medium, and subsequently automatically refresh the data to avoid loss of the data due to spontaneous thermal degradation. The apparatus and method may check whether an indicator (also called “refresh indicator”) if saved contemporaneous with writing of the data satisfies a predetermined condition indicating that the data needs to be refreshed. If so, a “refresh” operation is performed, wherein the to-be-refreshed data is read from and written back to the same storage medium. The refresh indicator can be any parameter that indicates a need to refresh the data prior to occurrence of one or more soft errors. In one example, the apparatus and method read the data back contemporaneous with writing of the data, and measure an amplitude of a readback signal and store, as the refresh indicator, a predetermined fraction (e.g. half) of the measured value (i.e., a threshold number). When a current value of the amplitude falls below the stored value, the data is refreshed.

Abstract: A failure analysis system of a logic LSI incorporates software therein. The analysis system includes a function to record the terminal signal information of said logic LSI in synchronization with a clock and a function to reproduce said recorded terminal signal information in synchronization with the clock. The analysis system further includes a function to compare said reproduced terminal signal information with the terminal signal information of a normal logic LSI.

Abstract: Embodiments of the present invention include a method and an apparatus for generating an optimal MRO for a zone having a plurality of tracks. A disc drive controller determines the optimum MRO of a zone of tracks by analyzing multiple tracks in the zone with the actuator arm located at a series of offsets relative to the track center. Selected tracks in the zone are written to once. Then the selected tracks in the zone are sequentially read at a first offset, and the corresponding errors recorded. This reading is repeated for each of the offsets until all offsets have been analyzed. Based on the offset, or band of offsets, with the least errors over the selected tracks, the optimum MRO can be selected for the zone. The process can be repeated for each zone and the optimum MRO values stored in an MRO table in the disc drive for use during subsequent read and write operations.

Abstract: A method for characterizing a read channel of a disk drive by storing a pseudorandom number (PN) sequence at a first location on a recording surface of the disk drive, and storing the PN sequence at a second location on the recording surface. The PN sequence at the first location is read to generate a first playback signal, and a first dibit response is determined from the first playback signal. The PN sequence at the second location is read to generate a second playback signal, and a second dibit response is determined from the first playback signal. The first and second dibit responses are arithmetically combined to generate a combined dibit response in which at least some non-linear echoes are isolated.

Abstract: Detecting flaws in a disk drive includes sampling a read signal provided by reading a data pattern from a disk to obtain samples, obtaining significant samples from the samples, deriving a value from the significant samples, and reporting a flaw if a comparison between the derived value and a threshold value is unacceptable.

Abstract: A first set of data is detected in a signal having synchronous samples and interpolated samples, wherein the first set of data is detected asynchronously as corresponding to one of the samples. A time to transmit a data-found signal is determined based on an offset between the data-detected sample and one of the synchronous samples, and the data-found signal is transmitted at the determined time to enable the synchronous processing of the synchronous samples. In one implementation, the synchronous samples correspond to a readback signal read from a data recording channel, the first set of data corresponds to servo address mark (SAM) data in a servo sector in the readback signal, and the synchronous processing is demodulation of burst data in the servo sector.