Abstract: A computer program product includes a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code being executable by a processing circuit to cause the processing circuit to perform the following process. A data transfer operation is monitored for detecting one or more temps. A backhitch delay is set based at least in part on a post-recovery condition of a tape drive performing a portion of the data transfer operation. A backhitch is caused to be performed. At least one condition of the data transfer operation is altered after the backhitch delay.

Abstract: An implementation of a system disclosed herein provides a method of deferring decoding of a data sector received at a read channel of a storage device, in response to determining that a data sector cannot be decoded by a first decoder and storing the data sector for further processing by a second decoder.

Abstract: According to one embodiment, a computer program product for dropout detection in a read channel includes a computer readable storage medium having program code embodied therewith, the embedded program code being readable and/or executable by a processor to execute dropout detection on a block of signal samples to detect one or more dropout events employing a set of decisions provided by a detector executing a detection algorithm, determine an approximate location for each of the one or more detected dropout events, statistically characterize the one or more detected dropout events to calculate one or more dropout profiles, and selectively filter the block of signal samples during a duration of each of the detected dropout events. Other computer program products, systems, and methods for detecting dropouts are presented in more embodiments.

Abstract: Devices and methods for reducing thermal stress within a head of a storage device are disclosed. In one or more embodiments, a method includes writing a selected pattern to a storage medium of a storage device using a head of the storage device; reading the selected pattern from the storage medium using the head to provide a data signal; and calculating an instability value of the head based on the data signal. The method can further include reconfiguring the storage device if the instability value is greater than an instability threshold by performing at least one of: deactivating a heater if the head includes two or more heaters; and increasing a fly height between the head and the storage medium.

Abstract: The present disclosure describes apparatuses and techniques of improved sequential-access of storage media. In some aspects an indication that a storage media interface failed to access a block of storage media is received during a sequential-access of the storage media and the storage media interface is caused to attempt to read a next block of the sequential-access subsequent the sector failed to be accessed during the same sequential-access.

Abstract: According to one embodiment, a system for selecting an optimum tape layout to store data on a tape medium may include a processor and logic integrated with and/or executable by the processor, the logic being configured to: select a family of data set layouts based on parameters associated with at least a tape drive and the tape medium, compute a set of all minimum distances for the selected family of data set layouts, calculate a first performance metric associated with each possible set of parameters, select a best first performance metric from all calculated first performance metrics and store a set of parameters associated with the best first performance metric, and select a data set layout algorithm which utilizes the set of parameters associated with the best first performance metric, wherein the data set layout algorithm and a rewrite layout algorithm combine to form an optimum tape layout.

Abstract: A data processing system includes a number of analog to digital converters operable to sample analog signals obtained from a magnetic storage medium to yield digital signals, multiple sync mark detectors operable to search for a number of different sync marks in the digital signals, and a sync mark detector output comparator operable to compare an output of each of the sync mark detectors to identify detection errors.

Abstract: The present disclosure includes systems and techniques relating to the use of evolutionary algorithms for tuning the performance of read channels. Instructions encoded on a medium are performed by processor cause a storage device to perform operations including obtaining values corresponding to operating parameters of a read channel of the storage device, generating one or more output parameters corresponding to use of the values with the read channel, selecting a proper subset of the values based on the one or more output parameters and a cost function, creating a new generation of the values corresponding to the operating parameters based on the proper subset and repeating the generating and the selecting using the new generation of the values until a target is achieved, and outputting two or more of the values of the proper subset of a last generation, when the target is achieved to configure the read channel.

Abstract: Track placement on a disk of a Data Storage Device (DSD) including writing test data in a plurality of sectors in a test track on the disk. An adjacent track on the disk is written offset from the test track by an offset distance. Data is read from the test track from an Off-Track Read Capability (OTRC) position outside of the test track. An OTRC value is determined for each sector of the plurality of sectors by varying the OTRC position and determining whether the sector meets a criterion for correctly reading data from the sector. An average OTRC value and a standard deviation are calculated for the plurality of sectors. If it is determined that the average OTRC value is greater than or equal to the predetermined multiple of the standard deviation of the OTRC values, the adjacent track is rewritten at a decreased offset distance.

Abstract: A hard disk drive has disks with data sector preambles that allow for inter-track interference. The same data sector preamble is used for all data sectors in a track but the preamble in each track is different from the preamble in radially adjacent tracks. In a first embodiment each preamble includes a synchronization field (SF) and synchronization mark (SM) that are the same in each track but different from the SF and SM in radially adjacent tracks. Only two unique SFs and two unique SMs are required, with the two SFs and two SMs alternating in radially adjacent tracks. In a second embodiment the preambles are “integrated”, meaning that the preamble is a sequence of bits that does not include separate dedicated fields, like SF and SM. The preamble bit sequences are decoded using matched filters to provide bit synchronization and start-of-data information.

Abstract: According to one embodiment, any of a first process to perform a write retry to a write target track, a second process to perform the write retry and perform reading for data verification to an adjacent track, and a third process to perform the write retry and write data of the adjacent track to another track is executed based on a result of comparison between an offtrack amount and a plurality of different slice values.

Abstract: Systems and methods are disclosed for performing band rewrites on shingled storage media based on error scan counts. In one embodiment, a device may comprise a data storage medium including a first band and a processor. The first band may include a plurality of tracks storing data in a shingled manner where a first track at least partially overlaps a second track. The processor may be configured to receive a write command directed to the first band, increment a first rewrite count of the first band based on the write command, and when the first rewrite count exceeds a first rewrite threshold, perform a read-modify-write (RMW) operation for all of the first band. In some embodiments, a device may maintain write counts for sections of a band, and perform RMW operations on less than all of the band.

Abstract: The disclosure is directed to a system and method of generating soft-orthogonal syncmarks for at least a first set of tracks and a second set of tracks. Random pairs of sync patterns are searched to identify one or more pairs where the sync patterns of each pair exhibit delta-like autocorrelation and small cross-correlation with each other and with preamble portions of the tracks. Then a pair of sync patterns is selected from the one or more identified pairs, where the selected pair includes sync patterns that are distinguishable from the user data portions of the tracks at least partially based upon a data characteristic of the user data portions of the tracks. The selected pair of sync patterns is then used to generate a first syncmark for the first set of tracks and a second syncmark for the second set of tracks.

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

Abstract: A two part process is used for modifying records to be written and retrieved from tape devices. A record is appended with a cyclic redundancy check and a string of zeros. Submitting the entire record to tape drives which are logical block protection enabled will result in no change. For drives that are not LBP enabled, the string of zeros at the end of the record is removed. In addition to determining whether a drive is LBP compliant, a determination may be made as to whether a drive is a linear tape open drive from a particular manufacturer. Linear tape open drives may behave similarly as drives which may not be enabled with logical block protection.

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

Abstract: A data storage device is disclosed comprising a head actuated over a disk. A read signal from the head is sampled to generate signal samples, and the signal samples are filtered with an equalizer filter to generate equalized samples. The equalized samples are filtered with an inter-track interference (ITI) filter to generate ITI attenuated samples, and a data sequence is detected based on the ITI attenuated samples. In one embodiment, the ITI filter comprises a transfer function: 1?HPF(ek) and in another embodiment the ITI filter comprises a transfer function: 1?LPF(ek) where ek represents a noise sequence in the equalized samples, HPF represents a high pass filter operating on ek, and LPF represents a low pass filter operating on ek.

Abstract: A magnetic storage system includes a magnetic storage medium, a random-access memory (RAM), and a controller. The controller interfaces with both the magnetic storage medium and the RAM, and implements a refresh algorithm that determines when a data track on the magnetic storage medium should be refreshed. The controller maintains in the magnetic storage medium a plurality of finer-granularity damage count tables, each table having finer-granularity damage counts each representing damage to one or more sectors within each of the plurality of tracks associated with the table. The controller maintains in RAM a plurality of track-level damage count values, each associated with one of the plurality of data tracks and representing estimated damage to one of the plurality of data tracks. Based on data written to the plurality of data tracks, the controller utilizes finer-granularity damage count tables stored in the magnetic media to update the track-level damage.

Abstract: In one embodiment, an apparatus includes logic configured to count each data set read and/or write access that used error recovery procedure (ERP) and each data set read and/or write access that did not use ERP, and logic configured to access subsequent data sets to read from and/or write to a data storage medium, wherein any subsequent data set read and/or write access that uses ERP is accessed using an initial ERP step characterized by a first speed of the data storage medium, and wherein the first speed is selected at least partially based on the count. Other systems and methods for ERP data access are described according to more embodiments.

Abstract: Technologies are described herein for recovering an instable head in a storage device using an internal head heater. An instability in the reader head may be detected, and, in response to detecting the instability, a thermal shock may be applied to the reader head utilizing the head heater to recover the head.

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

Abstract: A data processing system is disclosed including a data decoder circuit, an error handling circuit and a syndrome checker circuit. The data decoder circuit is operable to apply a data decode algorithm to a decoder input to yield a decoded output, and to calculate a syndrome indicating an error level for the decoded output. The error handling circuit is operable to determine whether any errors in the decoded output involve user data bits. The syndrome checker circuit is operable to trigger the error handling circuit based at least in part on the syndrome.

Abstract: The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for governing a data processing system.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of tracks defined by a plurality of servo sectors. An estimated track ID is generated and a plurality of proximate track IDs is generated having values proximate the estimated track ID. A set of Gray codes is generated each corresponding to the estimated track ID and the proximate track IDs, wherein each Gray code in the set of Gray codes comprises N bits, and M bits out of a high order of the N bits comprise the same value. A recorded Gray code is detected in a first servo sector to generate a detected Gray code, and an error in the detected Gray code is corrected by inverting at least one bit in the detected Gray code comprising a value that is different from the value of the corresponding bit in the M bits.

Abstract: Systems, methods, devices, circuits for data processing, and more particularly to data processing including adjacent track interference mitigation.

Abstract: Systems and method relating generally to improving usage of storage area on a disk drive, and more particularly to systems and methods for applying encoding based upon the nature of a particular region of a disk platter on the disk drive.

Abstract: A method, apparatus and a data storage device are provided for implementing track following and data recovery with readback of shingled data written in overlapping shingled data tracks on a recordable surface of a storage device. Positional information is identified with data readback of shingled data written in overlapping shingled data tracks. The identified positional information is used to selectively modify at least one predefined channel parameter, for example, to provide enhanced track following and enhanced data recovery.

Abstract: A set of decisions is determined based at last in part on a set of samples. For a given sample in the set of samples, a low frequency noise estimate is estimated based at least in part on (1) at least some samples from the set of samples and (2) at least some decisions from the set of decisions. A reduced noise sample is generated by removing the low frequency noise estimate from the given sample.

Abstract: A method and computer program product identify the location of a bad block on a disk platter of a hard disk drive, determine an avoidance area extending from the bad block, and prevent data from being written to the avoidance area.

Abstract: In one embodiment, a tape drive system includes a soft detector having logic configured to execute a first forward loop of a detection algorithm on a first block of signal samples during a first time interval, execute a first reverse loop of the detection algorithm on the first block of signal samples during a second time interval, execute a second reverse loop of the detection algorithm on the first block of signal samples during a fifth time interval, and execute a second forward loop of the detection algorithm on the first block of signal samples during a fourth time interval using second soft information. Other tape drive systems and computer program products for decoding data are presented in more embodiments.

Abstract: According to one embodiment, a data decoding control apparatus includes a reading controller and a decoding controller. The reading controller reads the encoded data of a symbol unit bit by bit from a storage medium. The decoding controller computes a log-likelihood ratio (LLR) value of the symbol unit for estimate decoding calculation relative to the encoded data based on the number of bit inversion in a symbol of the encoded data and a correction factor.

Abstract: A data storage device is disclosed comprising a disk comprising at least one servo seed pattern, and a head actuated over the disk. An amplitude measurement is generated based on a read signal emanating from the head while reading the disk. A number of times the amplitude measurement exceeds a first threshold is first counted during a first revolution of the disk, and a number of times the amplitude measurement exceeds the first threshold is second counted during a second revolution of the disk. The servo seed pattern is detected based on the first count and the second count.

Abstract: A storage device includes a storage medium having a plurality of tracks of data. Reading apparatus for reading a current track of data that has been subject to previous encroachment to an extent from at least one adjacent track of data includes a write head that writes interfering data to the adjacent track of data while intentionally encroaching at least to that extent onto the current track of data, and circuitry that recovers data on the current track of data using the interfering data. A method for reading a current track of data, that has been subject to previous encroachment to an extent from at least one adjacent track of data, includes writing interfering data to the adjacent track of data while intentionally encroaching at least to that extent onto the current track of data, and recovering data on the current track of data using the interfering data.

Abstract: A disk drive is disclosed comprising a head actuated over a disk having a plurality of data tracks. A vibration is detected, and a write operation is configured to write a first plurality of blocks and a second plurality of blocks to a target data track based on the detected vibration. The first plurality of blocks are written to the target data track during a first revolution of the disk, and the second plurality of blocks are written to the target data track during a second revolution of the disk.

Abstract: A reception device and corresponding method for maintaining a high dynamic range of an AD converter circuit and preventing excessive input to the AD converter circuit is disclosed. For example, a reception device includes a variable gain amplifier circuit that amplifies an input analog signal with a gain controlled by a predetermined control signal, an analog-to-digital converter circuit an overload detector circuit with the same frequency characteristic as the analog-to-digital converter circuit. The overload detector circuit outputs a signal according to a comparison between a level of a signal input to the analog-to-digital converter circuit and a predetermined threshold. The signal that lowers the gain of the variable gain amplifier circuit more greatly is selected out of the signal from the overload detector circuit and another signal, and the gain of the variable gain amplifier circuit is controlled on the basis of the selected signal.

Abstract: Technologies are described herein for implementing modulation coding schemes for TDMR. A data sequence is received to be stored on a first data track of a recording media. The first data sequence is encoded into a first codeword sequence using a modulation coding scheme, and the first codeword sequence is written to the first data track of the recording media. Subsequently, a second data sequence is received to be stored on a second data track of the recording media, the second data track being adjacent to the first data track. A second codeword sequence is generated for the second data sequence based on the first codeword sequence on the first data track, and the second codeword sequence is written to the second data track of the recording media.

Abstract: A two part process is used for modifying records to be written and retrieved from tape devices. A record is appended with a cyclic redundancy check and a string of zeros. Submitting the entire record to tape drives which are logical block protection enabled will result in no change. For drives that are not LBP enabled, the string of zeros at the end of the record is removed. In addition to determining whether a drive is LBP compliant, a determination may be made as to whether a drive is a linear tape open drive from a particular manufacturer. Linear tape open drives may behave similarly as drives which may not be enabled with logical block protection.

Abstract: A method for performing parallel flaw scans of a plurality of tracks of a storage device. The storage device includes at least one disk, at least two read sensors, at least two analog front ends, and at least two independent timing loops. Each disk includes at least one surface, wherein each surface includes a plurality of tracks. The method includes writing flaw patterns to tracks of one or more surfaces of one or more disks. The method also includes positioning a first read sensor to read a first track. The method further includes positioning a second read sensor to read a second track. The method additionally includes simultaneously reading signals from the first track and the second track. The method also includes simultaneously performing flaw scans on read back signals from the first track and the second track. The method further includes outputting flaw scan results.

Abstract: A media drive includes drive side circuitry that, in response to a request to validate compressed data read from media, validates packets of the compressed data while compressed and, in response to detecting end of data on the media without having detected an unrecoverable corrupt one of the packets and without decompressing the compressed data, generates a message indicating that the compressed data read from the media has been validated.

Abstract: A bit-patterned media (BPM) magnetic recording disk has two sizes of dots of magnetic material. The large and small dots are formed together in a hexagonal-close-packed (HCP) pattern. In the data regions none of the larger sized dots are adjacent one another; however in the servo regions some of the larger sized dots are adjacent one another. The adjacent larger sized dots form blocks that provide large amplitude “bursts” as the readback signal, as required for servo burst fields. The disk is made by imprint lithography using an imprint template, which can be made by directed self-assembly (DSA) of a block copolymer (BCP). The imprint template has two sizes of recesses, resulting in BPM disks with two sizes of dots. After the disks are imprinted they are exposed to a DC magnetic field, which magnetizes all the dots in the same direction.

Abstract: Various embodiments of the present invention provide apparatuses and methods for processing data in a multi-path data processing circuit. For example, an apparatus is disclosed that includes a first filter operable to process a first digital data stream to yield a first filtered digital data stream, a second filter operable to process a second digital data stream to yield a second filtered digital data stream, wherein the first and second digital data stream are representative of a same data set and wherein the first and second digital data stream have a different phase, a combining circuit operable to combine the first filtered digital data stream and the second filtered digital data stream to yield a combined data stream, and a data detector operable to detect a data sequence in the combined data stream.

Abstract: The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for performing data decoding including selective complexity data decoding.

Abstract: An apparatus for estimating head separation in an array reader magnetic recording system includes an array reader with multiple read heads operable to read data from a magnetic storage medium, a first preamplifier connected to a first read head, a second preamplifier connected to a second read head, and a head separation estimation circuit connected to the first preamplifier and to the second preamplifier, operable to estimate an integer phase offset and a fractional phase offset between a first signal from the first read head and a second signal from the second read head.

Abstract: A servo system includes a first equalizer circuit operable to filter digital servo data samples derived from a first read head to yield first equalized data, a second equalizer circuit operable to filter digital servo data samples derived from a second read head to yield second equalized data, a first interpolator operable to interpolate the first equalized data to yield a number of first interpolated outputs at different phases, a second interpolator operable to interpolate the second equalized data to yield a number of second interpolated outputs at different phases, and a phase tracking and signal combining circuit operable to select and combine most closely aligned signals from the first interpolated outputs and the second interpolated outputs to yield a combined servo data signal.

Abstract: A data processing circuit with flaw robust burst field demodulation includes a burst integration circuit operable to calculate burst integration results for a servo data burst field, a comparison circuit operable to determine whether an absolute value of the burst integration results falls outside a window, and an error indicating circuit operable to indicate that a media flaw has been detected when the absolute value of the burst integration results fall outside the window.

Abstract: A media data storage system comprising a data management portion, a local data storage portion, and a remote data storage portion. One data management portion comprises instructions associated with an intake, modification, transfer, and providing of media information. The local data storage portion comprises one or more first media data tape libraries adapted to receive the media information. The remote data storage portion comprises one or more second media data tape libraries adapted to receive the media information. Furthermore, the data management portion is adapted to instruct the local data storage portion to remove at least a portion of the media information from the one or more first media tape libraries upon verifying that the remote data storage portion comprises the at least a portion of the media information.

Abstract: A data processing circuit includes a subtraction circuit operable to subtract an ideal version of a data pattern from a sampled version of a data pattern to yield a difference signal, an error calculation circuit operable to calculate an error between the ideal version of the data pattern and the sampled version of the data pattern based on the difference signal, and a comparator circuit operable to compare the error with a threshold value and operable to assert a track refresh signal if the error is greater than the threshold value. The track refresh signal is operable to trigger a magnetic storage device to refresh data on a data track.

Abstract: The present inventions are related to systems and methods for determining contact between two elements, and more particularly to systems and methods for determining contact between a head assembly and a storage medium.

Abstract: A method and apparatus for storing a disk drive media defect table or list. Defect table entries for a subject disk track are stored on the subject track and retrieved for determining defective sectors only when the subject track is accessed for a data read or write operation.

Abstract: In one embodiment, a tape drive system includes a soft detector for executing a first forward loop of a detection algorithm on a first block of signal samples during a first time interval; and logic for executing forward and reverse loops during several time intervals; and logic adapted for outputting a first decoded block of signal samples based on the executing the decoding algorithm on the first block during a sixth time interval, wherein a sum of second, third, fourth, fifth, and sixth time intervals are about equal in duration to the first time interval.