Abstract: Methods and apparatus are provided for improved detection of servo sector data in a magnetic recording system using single bit error correction. Servo sector data is processed by detecting the servo sector data; determining whether a single bit error occurred in the detected servo sector data; and flipping a bit value of an individual bit in the detected servo sector data having a lowest amplitude sample among the samples of the detected servo sector data when a single bit error is detected in the detected servo sector data. The servo sector data comprises, for example, a servo address mark, Gray data, an RRO address mark and/or RRO data. For example, the bit value can be flipped by changing a binary value of one to a binary value of zero and changing a binary value of zero to a binary value of one.

Abstract: The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for bit error rate prediction in a data processing system.

Abstract: An apparatus comprises an alternating current coupling stage comprising a first filter configured to filter an analog signal to remove relatively low-frequency energy and read channel circuitry coupled to the alternating current coupling stage. The read channel circuitry comprises an analog-to-digital converter configured to convert the filtered analog signal to a digital signal, a detector configured to obtain a recovered signal using the digital signal, and a baseline correction module comprising a second filter and being configured to estimate a parameter of the first filter using a least mean squares algorithm based at least in part on the analog signal and an output of the second filter, adjust a parameter of the second filter based on the estimated parameter and add at least a portion of the removed relatively low-frequency energy to the digital signal by combining the output of the second filter and the digital signal.

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: Methods and apparatuses for managing read or write errors are disclosed. In one embodiment, a method may comprise receiving a command to perform an operation associated with first data and a first address of a data storage medium, performing the operation at the first address, retrying the operation when the operation did not complete successfully, and storing the first data to a second address when a first threshold is exceeded. In another embodiment, an apparatus may comprise a processor configured to: receive a command to perform an operation associated with first data and a first address of a data storage medium, perform the operation at the first address, retry the operation when the operation did not complete successfully, and store the first data to a second address when a first threshold is exceeded.

Abstract: The present invention is related to systems and methods for adaptive parameter modification in a data processing system.

Abstract: According to one embodiment, a magnetic disk device includes a first magnetic head corresponding to a first disk surface; a second magnetic head corresponding to a second disk surface; a skip processor which performs skip processing to prevent selection of the second magnetic head when the first magnetic head performs writing; a write data saving unit which selects the second magnetic head based on a result of the detection of ae write environment, and writes write data to the second disk surface through the second magnetic head; and a write data write-back unit which selects the first magnetic head based on a result of the detection of the write environment, and writes the write data written to the second disk surface to the first disk surface through the first magnetic head.

Abstract: A data storage device includes a storage medium on which data is stored in overlapping tracks, and a medium controller that directs storage of data on, and reading of data from, the storage medium, including encoding data being stored and decoding data being read. The decoding includes, when reading a first track, cancelling interference from a second track that overlaps the first track. The data storage device also includes a host controller in communication with the medium controller. The host controller includes memory that stores data decoded, and data to be written, by the medium controller. Communication between the medium controller and the host controller includes signals derived from data on said first and second tracks for facilitating the cancelling. A method of operating a data storage device includes, when reading a first track, facilitating the cancelling by communicating signals derived from the data on the first and second tracks.

Abstract: In one embodiment, a system includes a processor and logic integrated with and/or executable by the processor, the logic configured to: read data from a data storage medium, detect an error condition in data read from the data storage medium, determine how to allocate a ring buffer into a first portion and a second portion, the ring buffer being allocated for processing normal read and/or write requests, divide the ring buffer into the first portion and the second portion, wherein the first portion is allocated for processing normal read and/or write requests, and wherein the second portion is allocated for processing ERP requests, perform ERP on the data using the second portion of the ring buffer, determine that the ERP has been completed, and unify the ring buffer after the ERP is completed and allocate an entirety of the ring buffer for processing normal read and/or write requests.

Abstract: Various embodiments of the present invention provide systems and methods for recovering data from a storage medium. As an example, a data recovery circuit is disclosed that includes: a controller circuit, a data processing circuit, a selector circuit, and a combining circuit. The controller circuit is operable to position a sensor over a track of the storage medium at a first distance from the center of the track to yield a first data set, and to position the sensor over the track of the storage medium at a second distance from the center of the track to yield a second data set. The data processing circuit is operable to process a processing data set, and the selector circuit is operable to select between the first data set and a combined data set as the processing data set. The combining circuit is operable to combine the first data set with at least the second data set to yield the combined data set.

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

Abstract: Calibrating a read channel is disclosed. Previously written user data is read from an auxiliary memory. The previously written user data is processed through a plurality of write channel stages. The output of at least one of the plurality of write channel stages is compared to the output of a corresponding read channel stage to generate an error signal.

Abstract: There is disclosed a hard disk drive and an operation method thereof. A method of operating a hard disk drive according to the present invention may include (a) loading drive data required to drive the hard disk drive from a maintenance cylinder area contained in a disk to a memory; and (b) writing test data output from a head into a spare area contained in the maintenance cylinder area, wherein the steps (a) and (b) are carried out within a ready time.

Abstract: Embodiments of the present disclosure provide for reading data from a physical storage medium, transferring the data between a data channel and a test interface over a parallel data bus, and providing the data from the test interface at a serial port in a serial format.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of data tracks, wherein each data track comprises a plurality of data sectors. A host write command is received from a host, and previous data is read from at least one data sector which is combined with at least one of the host blocks to generate modified data that is written to the at least one data sector. At least one of a first read command and a first write command is generated, wherein the first read command is for reading the previous data from and the first write command is for writing the modified data to the at least one data sector. At least one of the first read command and the first write command is stored in a command queue for execution based on a rotational position optimization (RPO) algorithm.

Abstract: Techniques are described for constructing maximum transition run (MTR) modulation code based upon a multi-level (ML) run-length limited (RLL) finite state machine (FSM) that implements different sets of penalties. A processor is configured to receive information from a hard disk drive (HDD) via a read channel and recover data from the HDD using MTR modulation code. A memory has computer executable instructions configured for execution by the processor to model a magnetic recording channel as a partial response channel, model a source of information to the magnetic recording channel to provide an optimized Markov source, and construct an MTR modulation code to mimic the optimized Markov source based upon an FSM having a limited transition run length and a multi-level periodic structure. The FSM provides at least two different sets of penalties in a period.

Abstract: A magnetic recording disk drive determines the locations of defective bits in a failed data sector, and allows for the error correction code (ECC) to correctly decode the data from the sector. After a sector has failed decoding, the digitized waveform and the read channel state from the failed sector are stored in memory. A nondata pattern is written to the failed sector and read back to determine the locations of the defective data bits in the failed sector, which are then used to update the read channel state. The data pattern from the failed sector, with the identified bit error locations, is attempted to be decoded. If the decoding is successful then the sector is marked as bad and the correctly decoded data pattern is written to a different region of the disk, for example physical sectors specifically intended for use as spare sectors.

Abstract: Systems, methods, devices, circuits for data processing, and more particularly to cancelling noise while processing data.

Abstract: In a controller of a tape drive, a CM input-output unit recognizes a tape format; a tape variable acquisition unit acquires tape variables; a setting variable acquisition unit acquires setting variables; and a minimum number calculator calculates a minimum number m of sub datasets, which are to be written to a tape to secure resistance to burst error, by using the tape variables and setting variables. When a command processor receives a synchronization command, the buffer manager generates n sub datasets for storing data in the buffer. If n is smaller than m, m sub datasets are padded out and set as write data. If n is m or more, the n sub datasets are set as write data. Then, the channel input-output unit writes the write data to the tape.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of servo sectors defining a plurality of servo tracks, wherein the servo tracks form a plurality of servo zones, and a servo data rate of servo sectors in a first servo zone is different than a servo data rate of servo sectors in a second servo zone. A disk locked clock is synchronized to the data rate of the servo sectors in the first servo zone, wherein the disk locked clock for generating a timing window relative to the servo sectors. When the head crosses from the first servo zone to the second servo zone, at least one of the disk locked clock and the timing window is adjusted to compensate for a timing transient.

Abstract: Tuning a skew between a read head and a write head, may include setting a center value of a track according to a track density of a storage medium; writing data having a certain pattern to at least one target track and at least two tracks adjacent to the target track, while following the center value of the track; reading the data having a certain pattern from the target track by using a plurality of off track values in an off track range based on the center value of the track; and detecting an off track value having a minimum error occurrence number among error occurrence numbers with respect to the read data having a certain pattern corresponding to each of the plurality of off tracks, as an optimum off track value of the target track.

Abstract: An apparatus and associated method related to reading from memory an indicia that is dedicated to identifying a first portion less than an entirety of an addressable storage medium, the first portion having previously been subjected to a certification scrutiny. In relation to results of the reading, a second portion less than the entirety of the addressable storage medium is selected for subsequently subjecting the second portion to the certification scrutiny.

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

Abstract: An apparatus comprises read channel circuitry and associated signal processing circuitry. The signal processing circuitry comprises: an equalizer configured to combine an output of two or more component filters into a single equalized data signal; a detector with an input coupled to an output of the equalizer configured to determine a set of soft outputs, hard decision information and reliability indicators of the single equalized data signal; a decoder with an input coupled to an output of the detector configured to perform an iterative decoding process using the set of soft outputs, hard decision information and reliability indicators to determine a decoded data signal; and a multiplexer with a first input coupled to an output of the decoder, a second input coupled to an output of the detector, and an output coupled to an input of the equalizer. The hard decision information is used to train the equalizer.

Abstract: According to one embodiment, an information recording apparatus includes a divider, a generator, and a recorder. The divider is configured to divide recording data into a plurality of recording data blocks for each predetermined recording unit. The generator is configured to set, as a first block set, n recording data blocks recorded in corresponding areas in file system management areas of n, first to nth (n: integer, n?2) storages, and generate first parity data from the n recording data blocks forming the first block set. The recorder is configured to record the n recording data blocks forming the first block set and the first parity data.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. As an example, a data processing circuit is discussed that includes: a noise predictive filter circuit, a mean calculation circuit, a summation circuit, and a filter tap adaptation circuit. The noise predictive filter circuit is operable to perform a noise predictive filtering process on a data input based upon a selector input to yield a noise predictive output. The selector input is derived from a data detector output. The mean calculation circuit is operable to average two or more instances of the noise predictive output to yield a mean output. The summation circuit is operable to subtract the mean output from the noise predictive output to yield a sum output. The filter tap adaptation circuit is operable to adaptively calculate a filter tap based at least in part on a value derived from the data input and a value derived from the sum output.

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: Determining a parameter associated with whether a portion of a storage device is defective is disclosed. Determining comprises: obtaining known data associated with the portion; reading back from the portion to produce a read-back waveform; decoding the read-back waveform, including producing statistical information; and determining a parameter associated with whether the portion is defective based at least in part on the statistical information.

Abstract: In various embodiments, systems and methods to detect signal irregularity caused by defects in the read/write head element are disclosed. In some embodiments, an exemplary system comprises a memory and a processor. The processor is coupled to the memory and is configured to implement a filter module and a detector module. The filter module is configured to generate a test waveform based on data read from a medium by a storage device head to be tested. The detector module is configured to generate a signal quality value based on a property of at least a portion of the test waveform, compare the signal quality value to an event threshold, and generate an event indicator based on the comparison, the event indicator indicating possible instability of the storage device head.

Abstract: A storage apparatus has a first storage device in which the user data is stored and a second storage device which the management information including a primary hash value corresponding to the data management unit including a user data is stored for every data management unit. The storage apparatus (A) receives a read request, acquires a primary hash value of a first management unit which is a data management unit including read target user data from the second storage device, (B) reads data of the first management unit from the first storage device, (C) computes the primary hash value based on the data of the data management unit which is read, (D) determines whether the primary hash value in (A), and the primary hash value in (C) are in agreement, and (E) sends the read target user data to a upper level apparatus when the agreement is obtained.

Abstract: A disk drive is described with a single servo master timer that is used to control timing critical signals such as servo gate, SAM windows, channel power save, PREAMP power save and so on. The master timer is adjusted to compensate for SAM detection errors (early, late or missed) and provides improved servo timing quality. In an embodiment the adjustable master timer can be selectably clocked by either the DLC/DSW clock or the system clock.

Abstract: Apparatus and methods for performing defect scanning on a disk drive which includes a disk constructed to have tracks written on the disk for storing data. Test data is concurrently written in more than one track on the disk and the data written to the more than one track is read to detect defects on the disk.

Abstract: An extended servo mark word is used when an error is detected from a servo mark. For example, a servo mark associated with a disk drive track may be detected during a data access operation. In response to an error in detecting the servo mark, at least one adjacent bit is evaluated together with the servo address mark to overcome the error.

Abstract: Method and apparatus for identifying the track pitch capability of a recording device, such as but not limited to a recording system and/or a servo control system in a data storage device. In accordance with some embodiments, data are written to first and second tracks at an initial track pitch such that the second track at least partially overlaps the first track. Data are arranged on the first track in code words each having a fixed plurality of bits which are decoded as a group by a data channel. The code words are transferred from the first track to the data channel, and a final track pitch for subsequent tracks is responsive to a distance at which nominally half of the code words are undecodeable by the data channel.

Abstract: Read channel circuitry comprises a decoder and error correction circuitry. The error correction circuitry is configured to calibrate a first set of filters using a read channel data signal, to determine first hard decision information regarding the read channel data signal using the calibrated first set of filters, to determine an error corrected read channel data signal using the first hard decision information, to calibrate a second set of filters using the error corrected read channel data signal, to determine second hard decision information regarding the error corrected read channel data signal using the calibrated second set of filters, and to decode the second hard decision information. The first set of filters and the second set of filters are calibrated in respective first and second calibrators.

Abstract: Read channel circuitry comprises a decoder and error correction circuitry. The error correction circuitry is configured to calibrate a first set of filters using a read channel data signal, to determine first hard decision information regarding the read channel data signal using the calibrated first set of filters, to determine an error corrected read channel data signal using the first hard decision information, to calibrate a second set of filters using the error corrected read channel data signal, to determine second hard decision information regarding the error corrected read channel data signal using the calibrated second set of filters, and to decode the second hard decision information. The first set of filters and the second set of filters are calibrated in respective first and second calibrators.

Abstract: An apparatus includes, in at least one aspect, a plurality of buffers and circuitry configured to store encoded data in one buffer of the plurality of buffers concurrently with storing other data in another buffer of the plurality of buffers and to write the stored encoded data from the one buffer to a storage device concurrently with storing encoded other data in the other buffer, replacing the stored other data in the other buffer.

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: A channel circuit includes a reader, a decoder, a prediction module, and a seek module. The reader reads data written in a medium. The decoder performs iterative decoding of the read data. The prediction module predicts whether an early read is possible or not without waiting for arrival of the read data. The seek module continuously initiates a seek when the prediction module predicts that the read is possible.

Abstract: Methods for measuring media performance associated with adjacent track interference are provided. One such method includes iteratively writing data to a target track for each of a plurality of n frequencies, measuring a first signal amplitude and a first noise for each of the n sectors on the target track, writing an aggressor track pattern proximate the target track, measuring a second signal amplitude and a second noise for each of the n sectors on the target track, calculating a weighted sum for each of the signal amplitude measurements for each of the plurality of n frequencies, and calculating a weighted sum for each of the noise measurements for each of the plurality of n frequencies, and repeating the writing the aggressor track pattern, the measuring the second signal amplitude and the second noise, and calculating the weighted sums for preselected numbers of times.

Abstract: A method performed by a disk drive, comprising: receiving a plurality of signal samples over a channel in the disk drive; executing a forward pattern-dependent noise prediction (PDNP) operation on the plurality of the signal samples; generating, based on execution of the forward PDNP operation, a first detection of recorded data bits in the plurality of received signal samples; executing a backward PDNP operation on the plurality of the received signal samples; generating, based on execution of the backward PDNP operation, a second detection of recorded data bits in the plurality of received signal samples; comparing the first detection to the second detection; identifying, based on comparing, one or more erasures in the received plurality of signal samples; and generating one or more sequences of bits that promote correction of the one or more erasures.

Abstract: A disk drive is disclosed that enables defect margining during disk drive burn-in testing. The disk drive comprises: a disk comprising a plurality of tracks; a head actuated over the disk; and a processor. The processor is configured to: perform disk drive burn-in testing to detect media defects; generate an initial defect list based upon detected media defects for sectors; generate an extended defect list that includes detected media defects and extended defect margins from the detected media defects; and utilize the extended defect list for burn-in, wherein a spare area of the disk allows for the detected media defects and the extended defect margins.

Abstract: A magnetic disk control device according to an exemplary of the invention includes a write controller to control, in a magnetic disk having tracks, the track being a storage area made by concentrically dividing a magnetic recording layer formed onto a disk into a plurality of areas, the track being divided into a plurality of areas in a rotative direction as sectors, writing information into the each sector; and a substitution controller to make, by detecting the sector or the track written at a frequency higher than a writing frequency based on a number of times of writing by the write controller to the sector or the track and by moving information recorded in an adjacent track adjacent to a high-writing-frequency track including the detected high writing frequency sector or to a high-writing-frequency track which is detected as a high writing frequency track to a track of a substitution area.

Abstract: Aspects of the disclosure pertain to a read channel system and method for providing sector prioritization for promoting improved sector processing performance. The system and method, during processing of sectors of data, prioritize each of the sectors for further processing based upon: a global iteration index of each sector, trapping set characteristics of each sector and processing latency of each sector.

Abstract: Systems, circuits, devices and/or methods related to systems and methods for data processing, and more particularly to systems and methods for media defect detection.

Abstract: Aspects of the disclosure pertain to a read channel system and method for providing sector prioritization for promoting improved sector processing performance. The system and method, during processing of sectors of data, prioritize each of the sectors for further processing based upon: a global iteration index of each sector, trapping set characteristics of each sector and processing latency of each sector.

Abstract: Apparatus and methods for managing data stored in a disk drive having at least one disk including a first zone of tracks for storing data and a second zone of tracks for storing data, with the second zone being adjacent the first zone. It is determined whether a write counter for the first zone exceeds a threshold value. The write counter for the first zone represents a number of times the first zone has been completely written with data. If it is determined that the write counter for the first zone exceeds the threshold value, the disk drive is controlled to rewrite data from at least a portion of the second zone.

Abstract: A method to enable defect margining of a disk drive may comprise executing a data access command on a target sector on the disk drive. Upon encountering a data access error at the target sector, an address of the target sector may be added to an error list. The address of the target sector in the error list may then be converted to a physical location on the disk drive. A thermal asperity scan may be performed at and around the physical location and, upon detecting a thermal asperity, and at least sectors around the detected thermal asperity may be margined, and the data stored within the margined sectors may be relocated. Instead of sectors, entire tracks may be margined and the data stored therein relocated to a spare or reserve location, one track at a time.

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 representing an estimated radial location of the head. A high order Gray code in a first servo sector is detected, and errors in the high order Gray code are corrected using the estimated track ID to generate a corrected Gray code. The corrected Gray code is decoded into a first part of a detected track ID. A low order track code is detected in the first servo sector, and the low order track code is decoded into a second part of the detected track ID. The first part of the detected track ID is combined with the second part of the detected track ID.

Abstract: In a controller of a tape drive, a command processing unit receives a request to write new data, an offset determination unit determines whether old data is not partially overwritten with new data, and if old data is not partially overwritten with new data, a head position management unit makes a write head offset toward the unoverwritten portion. Then, a channel input/output unit reads pattern data that disables old data from a pattern storage unit and outputs the data to the write head to thereby overwrite the old data with the pattern data. After that, a tape transport management unit rewinds a tape and the head position management unit returns the write head to the original position to overwrite the old data with the new data as usual.