Abstract: A magnetic disk controller includes an error check code generating unit that generates error check codes associated with the encoded pieces of writing data; a first buffer that stores a first encoded piece of writing data and a first error check code associated with the first encoded piece; a second buffer that stores a second encoded piece of writing data and a second error check code associated with the second encoded piece; and a buffer control unit that, in a first period, substantially concurrently with a writing of the first encoded piece and the first error check code from the first buffer into a first sector of the magnetic disk, stores the second encoded piece and the second error check code into the second buffer.

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: A disc drive system provides increased reliability by detecting and correcting errors associated with bit-patterned media. Write synchronization errors associated with bit-patterned media are addressed by including data storage for temporarily storing data that is being written to the disc drive. The data is read from both the disc drive and the storage medium and compared to detect write synchronization errors. A disc drive system for correcting write synchronization errors includes an encoder, non-volatile storage, and decoder device for implementing a parity-based scheme for increased reliability. Data strings being written to the disc drive are combined in an encoder to generate a parity string. The address of the data being written to the disc drive, along with the updated parity string is stored to the non-volatile storage. The data strings are read from the disc drive by the decoder.

Abstract: A hybrid drive is disclosed comprising a head actuated over a disk comprising a plurality of data sectors, and a non-volatile semiconductor memory (NVSM) comprising a plurality of memory segments. A read command is received from a host to read data from a first data sector. Data is read from the first data sector during a first read operation and a determination is made as to whether the first data sector is suspect. When the first data sector is suspect, the data is written to a first memory segment of the NVSM.

Abstract: In memory devices that degrade with use, a memory controller may monitor and record a usage history of portions of the memory. The memory controller can then vary a strength of error correction coding to protect information written to various portions of the memory having different usage histories. More specifically, and memory can receive information to be stored in the memory, select a portion of memory to store the information, and store the information in the selected portion of the memory with an error correction coding having a strength that is based on a usage history of the selected portion of the memory.

Abstract: In one embodiment, a tape drive system includes a read channel configured for performing a portion of a data transfer operation, logic adapted for monitoring the data transfer operation for detecting one or more temps within a sliding window spanning a last group of datasets processed, logic adapted for measuring interference between first tier and second tier recovery methods based on the monitoring, logic adapted for setting a backhitch delay based on conditions relating to the interference of first tier and second tier recovery methods as it relates to a determined error burst, and logic adapted for performing a backhitch and altering at least one condition of the data transfer operation after the backhitch delay.

Abstract: The present invention is related to systems and methods for characterizing circuit operation, and more particularly to systems and methods for modifying a data decoding process.

Abstract: According to one embodiment, a magnetic recording and reproduction device includes a head; a heater configured to heat the head by electric power supplied; a detector provided with a resistive element and configured to detect a contact between the head and a magnetic recording medium by detecting a change in resistance of the resistive element associated with the contact between the head and the magnetic recording medium; and a flying height controller configured to control a flying height of the head from the magnetic recording medium by supplying electric power to the heater to thermally deform the head and to bring the deformed head into contact with the magnetic recording medium so as to determine reference power supplied when the head is in contact with the magnetic recording medium and by supplying electric power to the heater based on the reference power.

Abstract: A method and apparatus are disclosed for detecting an address mark in a data stream having a preamble followed by the address mark. The end of the preamble is detected in the data stream, which is then used to open a window to search for the address mark. If the address mark is not detected during the window, the search for the address mark is restarted. The window can have a duration based on a length of the address mark. The address mark can be, for example, a servo address mark following a servo preamble or a read address mark following a read preamble. The preamble can have a 2T pattern and the preamble can be detected by determining if energy associated with a 2T frequency is greater than energy associated with a non-2T frequency. The end of the preamble can be performed by an EndOf2T detector that detects a break in an expected bit pattern.

Abstract: Various embodiments of the present invention provide systems and methods for medium utilization control. As an example, a method for identifying potentially damaged media regions is discussed that includes receiving a data set; performing a data detection process on the data set to yield a detected output and a status value corresponding to the data set; performing a data decoding process on the detected output to yield a decoded output; and identifying a region of a storage medium from which the data set was derived as failing based at least in part on the status value.

Abstract: Disclosed are a method and system for distinguishing spatial and thermal defects on perpendicular media. The magnetic domains of the perpendicular media are oriented to have a first polarity, scanned using a read head, oriented to have a second polarity and scanned again. The signals from the read head are combined to produce output signals having improved signal to noise ratios from which the locations of spatial and thermal defects can be identified and distinguished.

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 length of a separator to be skipped on the storage disk is compared with a threshold. The threshold is associated with a maximum value for which a timing loop is able to be paused without causing the timing loop to have inaccurate timing. If the length is greater than the threshold, a first split sector format is assigned to the split sector and that information is recorded. In such cases, a first portion and a second portion both include synchronization information. If the length is less than the threshold, a second split sector format is assigned to the split sector and that information is recorded. In such cases, the first portion includes synchronization information and the second portion of the split sector excludes synchronization information.

Abstract: A disk drive is disclosed comprising a head actuated over a disk and control circuitry operable to sample a read signal emanating from the head to generate read samples. First vectors of log-likelihood ratios (LLRs) are generated in response to the read samples, wherein each vector corresponds to a nonbinary symbol q in a set of symbols. The first vectors of LLRs are biased to generate biased vectors of LLRs, and the biased vectors of LLRs are decoded into a data sequence, wherein the biased vectors of LLRs increase an error rate of the data sequence.

Abstract: A tape cartridge library that is equipped with a cleaning device is described. The tape cartridge library essentially includes a plurality of tape cartridges each possessing recording tape media. A plurality of tape drives that read and write data to and from each of the tape cartridges. A tape cleaning drive incapable of transferring data to and from the recording tape media which is independent of the tape drives, the tape cleaning drive disposed entirely within the tape cartridge library. The tape cleaning drive automatically receives one of the tape cartridges and cleans its respective recording tape medium when a predetermined reason for cleaning the tape cartridge is justified.

Abstract: A method of managing a defect of a hard disk drive includes calculating a number of ECC symbols of every sector which becomes an object of a defect scan and setting a defect reference value based on results of the calculation. The hard disk drive sets a sector as a defect sector having the number of ECC symbols greater than a set defect reference value.

Abstract: A method and apparatus for writing data to a tape is disclosed. A plurality of data tracks are written onto a tape simultaneously. Any data tracks written to the tape that needs to be rewritten are identified. Each re-write unit that contains a data track that needs to be re-written is accumulated. The accumulated rewrite units are written to tape when a full set of rewrite units have been accumulated.

Abstract: A method for randomizing data to mitigate false VFO detection is described. In one embodiment, such a method includes simultaneously receiving multiple input data streams. Each input data stream is associated with a different track on a magnetic tape medium. The input data streams are simultaneously scrambled to produce multiple randomized data streams. The input data streams are scrambled such that different bit patterns are produced in the randomized data streams even where corresponding bit patterns in the input data streams are identical. The randomized data streams are simultaneously written to their associated data tracks on the magnetic tape medium. A corresponding apparatus is also described.

Abstract: In a method of determining an iteration value for an iterative decoding process of a hard disk drive, a bit error rate (BER) of a digital signal is measured in multiple iterations. A difference is calculated between BERs of consecutive iterations, and the calculated differences are compared with a reference value. An adjusted iteration value is then determined based on the comparison.

Abstract: According to one embodiment, a magnetic disk drive includes a parameter management table, a parameter adjustment module and an interpolation module. The parameter management table stores a parameter used to write or read data to or from a disk in the parameter management table in association with each of a plurality of predetermined temperature divisions. The parameter adjustment module adjusts a first parameter stored in the parameter management table in association with a first temperature division to a second parameter adapted for the first temperature division if an ambient temperature detected by a temperature detector corresponds to the first temperature division and if the first parameter is unadjusted. The interpolation module updates an unadjusted third parameter corresponding to a third temperature division between the first temperature division and a second temperature division for which the parameter is adjusted based on a result of the adjustment of the first parameter.

Abstract: Systems and methods for performing refresh operations using write/read commands are provided. In one embodiment, a disk drive comprises a disk partitioned into a plurality of refresh zones, a head configured to write data to and read data from the disk, and a controller. The controller is configured to receive an access command, to read data from at least one of the refresh zones using the head in response to the access command, to check a condition of the read data, and to determine whether to refresh the at least one refresh zone based on the condition of the read data, wherein the read data includes data from a portion of the at least one refresh zone not being accessed by the access command.

Abstract: A rewriting apparatus control circuit includes a display system and a processor. The processor includes a first input terminal receiving a rewriting complete signal from the rewriting apparatus; a second input terminal receiving a rewriting success signal from the rewriting apparatus; an output terminal connecting to the rewrite apparatus for sending a restarting signal; and data terminals connected to the display system. Once the rewriting complete signal from the rewriting apparatus is received, the processor subtracts one for each restarting sent from a preset number and then sends a result to the display system for displaying and sends the restarting signal to the rewriting apparatus for restarting the rewriting apparatus if the result is greater than zero. The processor accumulates a number of times that the rewriting success signal is received from the rewriting apparatus, and sends the number to the display system for displaying when the result is zero.

Abstract: A system including a data detection module, a reconstruction filter module, a first correlation module, and a second correlation module, The data detection module detects data bits from input signals. The reconstruction filter module generates reconstructed signals using the data bits. The first correlation module correlates the input signals and the reconstructed signals and generates first correlation values. The second correlation module self-correlates the reconstructed signals and generates second correlation values. In response to at least one of the input signals and the reconstructed signals including a B-bit floating number having a sign bit, at least one of the first correlation module and the second correlation module generates the first correlation values and the second correlation values based on the sign bit and K most significant bits (MSBs) of the B-bit floating number, where 0 <K <(B-1), and B is an integer greater than 1.

Abstract: A mass data storage system including a data storage device comprising block groups each comprising a plurality of data blocks determines when one of the block groups is faulty and the data storage device continues to operate as a partially failed data storage device with respect to the remaining block groups which are not faulty. A striped parity data storage device array comprises data storage devices capable of operating as partially failed data storage devices allows copying of data from the block groups not associated with determined to be faulty of a partially failed data storage device to a spare data storage device which reduces the amount of data that must be rebuilt in the rebuild process, thereby reducing the amount of time the array spends in degraded mode exposed to a total loss of data caused by a subsequent data storage device failure.

Abstract: Systems, methods and computer program products for writing and reading a plurality of data sets and error codes are described. In some implementations, a magnetic disk controller can be provided that includes an error code unit configured to generate one or more error codes for each of a plurality of data sets to be written onto corresponding sectors of a medium. The magnetic disk controller can also include a buffer unit configured to store each data set and an error code in an associated buffer, and an encoding unit configured to encode the plurality of data sets. In some implementations, at least one data set is encoded concurrently with the buffer unit storing another different data set in the associated buffer. The magnetic disk controller can also include a control unit configured to write each encoded data set and a corresponding error code onto a corresponding sector.

Abstract: A data storage device determines a zone layout based on a quality evaluation factor. The zone layout is designed such that a measurement value of the quality evaluation factor for each track in each zone is within a range between a predetermined upper limit and a predetermined lower limit and a maximum amount of variation of the measurement value within each zone is substantially equal to a difference between the upper limit and the lower limit.

Abstract: A control module for a rotating storage medium. The control module includes: a memory, a buffer control module, and a disk formatter module. The memory is configured to store a data wedge format table including a plurality of entries. The buffer control module is configured to maintain a queue, wherein each of a plurality of entries of the queue is based on a corresponding one of the plurality of entries of the data wedge format table, and wherein each of the plurality of entries of the queue includes a servo number. The disk formatter module is configured to compare the servo numbers of the plurality of entries of the queue to present servo information, wherein the present servo information is based on a present position of a read/write device in relation to the rotating storage medium.

Abstract: A method in one embodiment includes receiving a command to perform at least one of a refresh operation and a verification operation on a media cartridge having a tape wrapped around a spool; mounting the media cartridge in a tape drive; starting execution of the refresh and/or verification operation; aborting execution of the refresh and/or verification operation upon occurrence of a predetermined event. A method in another embodiment includes receiving an instruction to perform a verification operation on a media cartridge having a tape wrapped around a spool; unwrapping at least some of the tape from the spool; after the unwrapping, wrapping at least some of the tape back onto the spool; during at least one of the unwrapping and wrapping, performing a verification operation; terminating execution of the verification operation when a drive error is detected; outputting an indication of a media error when a media error is encountered.

Abstract: Various embodiments of the present invention provide systems and methods for synchronizing data processing. As one example, a method for synchronizing data processing is disclosed that includes receiving a data input, and sampling the data input at a sample period to generate a sample set. A first pattern is received and a first periodic boundary associated with the first pattern is identified. In one particular case, the first pattern is a preamble pattern included as sector data on a storage medium, and the first periodic boundary is a 4T boundary. Further, a second pattern is detected in the sample that is used to establish a second periodic boundary. In one particular case, the second pattern is a SAM pattern included as sector data on a storage medium, and the second periodic boundary is a 1T boundary. Based at least in part on the first periodic boundary and the second periodic boundary, a time to transmit or assert a data-found signal is determined.

Abstract: According to one embodiment, a magnetic disk device having a disk, includes: a flag updating module configured to register a flag used when data is written onto the disk, the data is read from the disk and whether to verify the data or not is determined, so as to be associated with each of a plurality of predetermined temperature sections; a temperature detector configured to detect an environmental temperature of the magnetic disk device; a verifying module configured to determine whether to execute the verification or not according to a flag where the detected environmental temperature corresponds to one temperature section of the plurality of temperature sections and that is registered by the flag updating module so as to be associated with the one temperature section; and a measuring module configured to measure an error rate at a same point in time as the verification.

Abstract: A method according to one embodiment includes: deciding to perform a refresh operation on a media cartridge having a tape wrapped around a spool; determining which drive of a plurality of drives is available to perform the refresh operation; causing the media cartridge to be mounted to the available drive; causing the drive to unwrap the tape from the spool of the media cartridge to about an end of the tape; and causing the drive to wrap the tape back onto the spool after the unwrapping, wherein at least some data on the tape is overwritten with new data, and a verification operation is performed using the new data.

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: Embodiments described herein include systems and methods for correcting for errors caused by disturbances to disk drives, such as disturbances due to shocks or vibrations incident on the drive. For example, systems and methods described herein advantageously correct for corruption to current data as well as previously written. Data may be rewritten in the current track that was being written to when the disturbance occurred, and may also be rewritten to one or more nearby previously written tracks, such as one or more adjacent tracks. According to some aspects, the direction of head deviation is used to select the appropriate corrective action.

Abstract: The method of controlling a defect of a hard disk drive that includes analyzing a defect type by using indexes of error corrected symbols after performing error correction with respect to each of a plurality of symbols and setting a sector as unusable when the sector includes a defect that is determined to be a defect having a defect type that is a hard defect.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of data sectors. A redundancy generator is loaded with a first seed value corresponding to system data generated internal to the disk drive. First data path redundancy symbols are generated in response to the first seed value, and the system data and the first data path redundancy symbols are written to a first data sector. A syndrome generator is loaded with the first seed value to generate first syndromes when reading the system data and first data path redundancy symbols from the first data sector. The validity of the system data is verified in response to the first syndromes.

Abstract: A method of evaluating a magnetic recording medium using a magnetic head having a reproduction element is disclosed The method includes the steps of (a) recording a signal in a predetermined area of the magnetic recording medium; (b) determining a first value of a reproduction output by reproducing the predetermined area of the magnetic recording medium; (c) determining a second value of the reproduction output by emitting an energy line having a power of a predetermined value onto the predetermined area and reproducing the predetermined area with the reproduction element during or after the emission of the energy line; and (d) calculating a change in the reproduction output due to the emission of the energy line based on the first value and the second value of the reproduction output.

Abstract: A hard disk drive that includes a disk with data written onto a plurality of tracks, a spindle motor that rotates the disk, and a head that is coupled to the disk. The disk drive also includes a circuit that writes data onto a first writable shingle band of tracks if the first writable shingle band is adjacent to a guard band of tracks. The first writable shingle band includes a number of tracks that is a function of a head width. The guard band of tracks is capable of becoming a writable shingle band. Changing the designation of a shingle band between guard and writable creates floating guard bands. The creation of floating guard bands allows for the writing of a single band without having to move and restore adjacent tracks until reaching a fixed guard band as required in the prior art.

Abstract: A magnetic disk device includes a disk that includes a plurality of tracks and magnetically stores therein data; a magnetic head that reads and writes data on the tracks; a data writing unit that classifies sectors along one track into a plurality of sector groups and writes to a physical address of each of the sector groups data of a logical address that is different from a logical address corresponding to the physical address in same track; and a first nonvolatile memory that stores therein a conversion table of the logical address and the physical address.

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 data processing. As an example, a block-wise data processing circuit is discussed that includes: a data buffer, an inter-track interference response circuit, and an inter-track interference signal estimator circuit. The data buffer is operable to store a previous track data set corresponding to a block. The inter-track interference response circuit is operable to estimate an inter-track interference response from the previous track data set across the block based at least in part on the previous track data set and a current track data set. The inter-track interference signal estimator circuit is operable to calculate an inter-track interference from the previous track data set across the block based at least in part on the previous track data set and the inter-track interference response from the previous track data set.

Abstract: A disk drive comprising a disk, a head actuated over the disk, a read/write channel, a control processor, and a servo system is disclosed. The servo system is configured to read servo information from a servo wedge on the disk via the read/write channel, to generate first and second status information based on the read servo information, to output the first and second status information to the control processor, and to output first and second interrupt signals to the control processor, the first and second interrupt signals being spaced apart by a time delay. In response to the first interrupt signal, the control processor is configured to determine whether to release data from a host based on the first status information, and in response to the second interrupt signal, the control processor is configured to determine whether to release data from the host based on the second status information.

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 method for operating log likelihood ratios in a disk apparatus is disclosed. Iterative decoding is applied to the disk apparatus. The method can set windows for a sequence of the log likelihood ratios output by a soft-decision most-likelihood decoder based on the sequence of the log likelihood ratios or an amplitude of a read signal acquired in response to read of data from a data sector on a disk carried out by a head. The method can multiply the log likelihood ratios contained in each of the windows, by a multiplier specific to each window. In addition, the method can transmit the sequence of the log likelihood ratios multiplied by the multiplier for each of the windows to a parity check decoder.

Abstract: A data storage library is described including a plurality of tape cartridges wherein each of the tape cartridges possesses an auxiliary radio frequency memory device in which auxiliary digital data is stored. The library also includes at least one drive disposed substantially within the library capable of transferring user data to and from one of the tapes. The library further includes at least one auxiliary radio frequency memory device reader that capable of reading the auxiliary digital data and transmitting the auxiliary digital data to at least one designated location, the reader is independent of the at least one drive.

Abstract: Track pitch in a hard disk drive is selected to satisfy the requirements of both off-track capacity (OTC) and adjacent track interference (ATI). The invention separately measures the track pitch requirements for OTC and ATI. The track pitch for the drive is set with the larger of the OTC and ATI track pitches. The OTC track pitch is measured with a 747 curve, and the ATI track pitch is measured by the positions of adjacent tracks at which the on-track error rate is not worse than a given value after the targeted number of adjacent track writes in the ATI requirement.

Abstract: According to one embodiment, there is provided a magnetic recording medium having a data region in which a plurality of recording tracks, each including magnetic dots arrayed in a down-track direction with a pitch p, are formed in a cross-track direction, and a servo region including a preamble in which a plurality of lines of magnetic dots, which are arrayed in a cross-track direction with a pitch p, are formed at equal intervals in the down-track direction.

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: A system in one embodiment includes multiple analog inputs for receiving readback signals, an analog to digital converter coupled to each of the analog inputs for converting the readback signals to digital signals, a buffer coupled to outputs of the analog to digital converters for at least temporarily storing the digital signals, and a digital processing section also coupled to outputs of the analog to digital converters for processing the digital signals for reconstructing data therefrom. A method in one embodiment includes receiving multiple channels of analog readback signals from a magnetic head, converting the analog signals in each channel to digital signals, buffering the digital signals, and outputting the buffered digital signals. A method in another embodiment includes receiving a readback waveform from a magnetic storage device, reducing a frequency offset of the readback waveform, and generating a synchronized, oversampled waveform from the readback waveform.

Abstract: Formatting a storage disk is disclosed. A first portion of a sector of the storage disk is defined. The first portion precedes a defect and has a first length that varies based on a detected location of the defect. A second portion of the sector of the storage disk is defined. The second portion follows the defect and has a second length that varies based on the detected location of the defect.

Abstract: A method is disclosed for selecting a format for a disk surface of a disk drive, the disk drive comprising the disk surface, and a head actuated over the disk surface. A first TPI is selected for the disk surface, and then evaluated to determine whether it is compatible with a first target capacity. If the first TPI is not compatible with the first target capacity, then a second TPI is selected for the disk surface wherein the second TPI is less than the first TPI.