Abstract: A magnetic disk device includes a magnetic disk including a track having a plurality of sectors, a motor configured to rotate the magnetic disk, a magnetic head, and a controller. The controller is configured to perform a first read operation of reading target sectors among the sectors of the track, with the magnetic head during a first revolution of the magnetic disk, detect an off-track state of the magnetic head during the first revolution of the magnetic disk, perform a first error correction with respect to data read from the target sectors during the first read operation, and perform a second read operation of selectively reading a part of the target sectors for which the off-track state has been detected or the first error correction is unsuccessful, with the magnetic head during a second revolution of the magnetic disk.

Abstract: According to one embodiment, a magnetic reproducing and processing device includes an acquirer and a processor. The acquirer is configured to acquire a first electric signal obtained by reproducing information recorded in a first recording area of a magnetic recording medium by a first reproducing element and a second electric signal obtained by reproducing the information recorded in the first recording area by a second reproducing element. A first sensitivity of the first reproducing element to a magnetic signal recorded on the magnetic recording medium is different from a second sensitivity of the second reproducing element to the magnetic signal. The processor is configured to output a reproduced signal corresponding to the information recorded in the first recording area based on the first electric signal and the second electric signal acquired by the acquirer.

Abstract: A memory system includes a memory device including a plurality of memory blocks, and a controller for controlling the memory device. The controller stores user data in an original block selected among the memory blocks. When the original block becomes a closed block, the controller generates a copy block by copying each page of the original block into a page having the same page address of a free block among the memory blocks, and stores map data associated with the user data in the memory device, the map data including a logical address of the user data, an address of the original block, an address of the copy block, and a common page address. The common page address is a page address which is in common in the original block and the copy block. In embodiments, the controller limits the number of copy blocks according to a configurable copy level.

Abstract: Apparatuses and methods are described for processing the sensor signal of a sensor component, a noise signal that is generated as a function of specific properties of an interference signal component of the sensor signal and/or of specific properties of a temperature signal of a temperature sensor being mixed into a useful signal component of the sensor signal.

Abstract: Systems and methods for improving seek times in a read channel performing a read operation on a disk drive are disclosed. The method includes extrapolating, based on initial filter settings corresponding to a first user-data region or a first servo-data region and tracked settings varying over time, a proportionality constant for the programmable analog filter, in response to determining a new target frequency for the programmable analog filter corresponding to a second user-data region or a second servo-data region, computing new filter settings for the programmable analog filter based on the extrapolated proportionality constant, and transmitting, to the programmable analog filter, the computed new filter settings corresponding to the new target frequency of the second user-data region or the second servo-data region.

Abstract: A magnetic disk device includes a magnetic disk, a read head for reading data from sectors and tracks of the magnetic disk, a read channel including a first circuit configured to process an output signal from the read head according to a value of a parameter, and processor. The processor is configured to, upon detection of a read error while the read head is reading data from an error sector of an error track, determine an error amount in each sector in the error track, select from the error track a plurality of sectors having an error amount that is within a predetermined range from an error amount of the error sector, perform a training read on the selected sectors, determine a new value of the parameter based on the training read, and set the new value of the parameter for the read channel.

Abstract: A system is provided to receive a first request to write data to a hard disk drive (HDD) which comprises a plurality of tracks which can be configured as a conventional magnetic recording (CMR) media or as a shingled magnetic recording (SMR) media, wherein an SMR-configured track stores a greater amount of data than a CMR-configured track. The system writes the data to a first CMR-configured track, and classifies data stored in CMR-configured tracks as hot or cold based on a first or a second predetermined threshold. The system copies cold data from the CMR-configured tracks to an SMR zone, and makes available portions of the CMR-configured tracks previously occupied by the cold data.

Abstract: A current detection system includes an inductor and a detection circuit coupled across the inductor. The inductor is configured to receive an input signal that includes an input current and generate a voltage across the inductor. The current detection circuit includes a sensing network and a transconductance amplifier. The sensing network includes a capacitor and is configured to monitor a voltage across the inductor. The transconductance amplifier is configured to receive a differential voltage indicative of a voltage drop across the capacitor and output a differential output current proportional to the differential voltage.

Abstract: A computer-implemented method, according to one approach, includes: receiving a request to read a plurality of files from a magnetic tape, and obtaining a tape directory which identifies regions on the magnetic tape in which the files are stored. The tape directory is used to map each of the files to one of the regions on the magnetic tape in which the respective file is stored. A first subset of the files stored in a same first region on the magnetic tape is also sorted into a first order. The computer-implemented method further includes simultaneously: sorting a second subset of the files stored in a same second region on the magnetic tape into a second order, and instructing a tape drive to read each of the files in the first subset according to the first order.

Abstract: A receiver device receives a signal via a communication channel, the signal (i) having been transmitted by a transmitter device, and (ii) corresponding to a pseudorandom bit sequence (PRBS). The receiver device correlates the received signal with a known signal to generate a correlation signal. The known signal includes the PRBS. The receiver device identifies one or more characteristics of the correlation signal, and determines one or more parameters of the communication channel using the identified one or more characteristics of the correlation signal. The receiver device i) uses the one or more parameters corresponding to the communication channel to process subsequent signals received via the communication channel, and/or ii) communicates the one or more parameters to the transmitter device to prompt the transmitter device to preprocess subsequent signals to be transmitted via the communication channel by the transmitter device.

Abstract: A method according to one embodiment includes applying a static head skew to a magnetic tape head, positioning the first reader at a first y-position relative to a servo pattern in a servo band, and measuring y-positions of the second reader relative to the servo pattern in the servo band while the first reader is at the first y-position. A y-position value is calculated for the second reader based on the measured y-positions. The following process is repeated several times: moving the first reader to a next y-position, measuring y-positions of the second reader while the first reader is at the next y-position, and calculating a y-position value of the second reader based on the measured y-position of the second reader. A unique nonlinearity value of the servo pattern in the servo band is calculated for each of the calculated y-position values of the second reader.

Abstract: A method, computer system, and a computer program product for verifying data written to a tape is provided. The present invention may include preparing a first group of data to be written to the tape; signaling a tape drive to perform a write operation to write the first group of data to the tape; receiving from the tape drive a tape head location signal, wherein the tape head location signal indicates that the tape drive has detected that the tape movement during the write operation has reached a turnaround point; performing a read operation to read the first group of data from the tape; receiving from the tape drive a second group of data read by the tape drive during the read operation; and comparing the first group of data to the second group of data.

Abstract: In one embodiment, a system includes logic configured to receive data comprising a plurality of data elements, where each data element comprises one or more bits. Further, the logic is configured to output bursts of data comprising the plurality of data elements along with a number of parity bits equal to a number of data elements in the plurality of data elements received from a first parity module to an input of a data path. Further still, the system includes a binary sequence generator configured to create a binary sequence comprising a plurality of bonus bits in a pseudo-random pattern that has less than a predetermined chance of matching any sequence of bits in the data while in the data path. Further still, the first parity module is configured to provide a parity calculation prior to passing the plurality of data elements to the input of the data path.

Abstract: A data storage device is disclosed comprising a disk comprising servo data, and an actuator configured to actuate a head radially over the disk. The disk drive further comprises control circuitry comprising a servo controller and a driver circuit comprising an accumulator, wherein the servo controller is configured to generate digital control values based on the servo data and transmit the digital control values over a serial interface to the drive circuit. The accumulator is initialized based on a first digital control value received over the serial interface during a first servo interval, and then the accumulator is adjusted based on a second digital control value received over the serial interface during a second servo interval. An analog control signal is generated based on an output of the accumulator, and the analog control signal is applied to the actuator.

Abstract: According to one embodiment, a magnetic disk device includes a magnetic disk, a recording head and a controller configured to control the recording head. The recording head includes a high-frequency oscillator disposed in a write gap formed between a main magnetic pole and a return magnetic pole, and a bias voltage application circuit configured to apply a bias voltage to the high-frequency oscillator. The controller includes a bias voltage controller configured to change a bias voltage to be applied to the high-frequency oscillator in accordance with a sampling frequency of data before the data is recorded on the magnetic disk by the recording head.

Abstract: A tape drive allows for an increased track density by partially overlapping adjacent tracks as each successive track is written. Each successive track overwrites a portion of the width of the previous track, thereby reducing the width of the previous track. This process can be applied repeatedly thereby producing an arrangement of shingled data tracks across the width of the tape. In an embodiment, single-pass verification of data written in this manner is accomplished using a head assembly with two read heads per track. A first read head positioned behind the write head verifies that the data written is correct, and a second read head positioned over the previous track verifies that data on the previous track remains intact after being partially overwritten.

Abstract: An apparatus may comprise a circuit configured to receive first underlying data corresponding to a first signal and receive a second signal corresponding to second underlying data. The circuit may determine an interference component signal based on the first underlying data corresponding to the first signal and a first channel pulse response shape for the first signal, determine estimated decisions corresponding to the second signal based on the second signal, and determine an estimated signal based on the estimated decisions corresponding to the second signal and a second channel pulse response shape for the second signal. The circuit may then generate a remaining signal based on the estimated signal and the second signal, generate an error signal based on the interference component signal and the remaining signal, and adapt one or more parameters of the first channel pulse response shape based on the error signal.

Abstract: A tape drive-implemented method, according to one embodiment, includes: determining formatting information which corresponds to a magnetic tape loaded in the tape drive, and using the formatting information to identify wraps on the magnetic tape. Identifying wraps on the magnetic tape includes: identifying an outermost wrap on the magnetic tape on a first side of the magnetic tape, and identifying an outermost wrap on the magnetic tape on a second side of the magnetic tape. A procedure is also performed for each of the wraps identified using the formatting information. Performing the procedure for a given one of the wraps includes: sending one or more instructions to position a magnetic head of the tape drive over the given wrap, sending one or more instructions to move the magnetic tape over the magnetic head, and collecting PES information which corresponds to the given wrap.

Abstract: A hard disc drive includes a slider including a first reader and a second reader. The hard disc drive also includes a magnetic recording medium and a controller. The controller is configured to determine a distance between the slider and the magnetic recording medium based at least in part on amplitudes of read signals from both the first reader and the second reader.

Abstract: A temperature compensation equation is generated during manufacture of a heat-assisted magnetic recording (HAMR) disk drive using initial total currents supplied to a laser diode of the disk drive at different initial operating temperatures. The total currents represent currents for recording data to or erasing data from the medium. The temperature compensation equation is stored in the disk drive, and updated, during field operation, using a subsequent total current associated with an operating temperature differing from the initial operating temperatures. The total current supplied to the laser diode for a subsequent write operation is adjusted using the updated temperature compensation equation in response to the operating temperature at the time of the subsequent write operation.

Abstract: Mounting a data storage medium having information recorded thereon, where: the information is formatted according to a data storage format standard that includes first write and read functions, the information includes first and second datasets, the first dataset includes a first file mark, an index, and an empty space between the second dataset and a combination of the first file mark and the index; receiving, from a first application, a data block and a write command for writing the data block onto the data storage medium; and in response to receiving the write command: determining that the empty space is present in the first dataset, writing, by a second write function, the data block into the empty space, and writing a second file mark in the second dataset; wherein the empty space of the data storage medium is inaccessible to the first write function of the data storage format standard.

Abstract: A method for performing a flaw scan test on a hard disk drive is disclosed. The hard disk drive includes a magnetic recording medium and spindle motor associated with a predetermined rated speed. The method includes writing a test pattern to the magnetic recording medium while operating the spindle motor at a speed greater than the predetermined rated speed. The method also includes reading the test pattern at the greater speed and detecting flaws in response to reading the test pattern.

Abstract: A receiver for data recovery from a channel signal of a communications channel. The receiver includes a quantization circuit to generate a quantized code corresponding to the channel signal. A first decision circuit recovers, in a first signal processing mode, digital data for the channel signal based on the quantized representation of the channel signal. A second decision circuit recovers, in a second signal processing mode, the digital data for the channel signal based on the quantized representation of the channel signal. A controller selects between the first signal processing mode and the second signal processing mode based on a parameter indicative of a signal quality of the channel signal.

Abstract: An apparatus may include a circuit configured to generate a set of first ADC samples based on a first signal associated with a first read head position and a failed segment and to generate a set of second ADC samples based on a second signal associated with a second read head position and the failed segment. The circuit may then generate, by a MISO equalizer, a set of equalized ADC samples based on the set of first ADC samples and the set of second ADC samples.

Abstract: A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a fly height actuator (FHA). An FHA control signal is applied to the FHA, wherein the FHA control signal comprises a rectangular wave having a duty cycle in the range of ten percent to thirty percent. While applying the FHA control signal to the FHA, the head touching down onto the disk is detected.

Abstract: An optical module for connecting a ferrule for connecting an optical fiber and a photoelectric transducer mounted on a substrate includes first lenses, second lenses, and a dummy lens. The first lenses are provided on a first side of the optical module to which the ferrule is to be connected. The second lenses and the dummy lens are provided on a second side of the optical module facing a surface of the substrate. The second lenses and the dummy lens are aligned on the same line. An image of the dummy lens is reflected from a mirror to be projected onto a plane on the first side of the optical module.

Abstract: According to one embodiment, a magnetic disk device including a disk, a head that writes data in the disk, and reads data from the disk, and a controller that generates second data of when first data is written in the disk based on the first data read from the disk, generates third data indicating change in an amplitude of the first data due to thermal fluctuation based on the second data, and adjusts the first data based on the third data.

Abstract: Various embodiments for data error recovery in a tape storage system, by a processor device, are provided. In one embodiment, a method comprises, in a tape storage system using an iterative hardware and microcode decoder, initializing at least one iterative decode cycle on the buffered dataset when an uncorrectable read error occurs; and for a next iterative decode cycle, building upon data corrections obtained in a previous iterative decode cycle.

Abstract: A memory system, sensor circuit, and method of operating a memory system are provided. The disclosed memory system includes a first transducer configured to output a first electrical signal indicative of a first operating parameter of the memory system. The memory system is further disclosed to include a second transducer configured to output a second electrical signal indicative of a second operating parameter of the memory system where the second transducer shares a node with the first transducer. The memory system is further disclosed to include a sense amplifier that receives the first electrical signal and the second electrical signal and provide an output responsive to both the first electrical signal and the second electrical signal to a preamplifier Integrated Circuit (IC).

Abstract: Mounting a data storage medium having information recorded thereon, where: the information is formatted according to a self-describing format standard that includes first write and first read functions, the information includes first and second datasets, the first dataset includes a first file mark, an index, and an empty space between the second dataset and a combination of the first file mark and the index; receiving, from a first application, a data block and a corresponding write command for writing the data block onto the data storage medium; and in response to receiving the write command: determining that the empty space is present in the first dataset, writing, by a second write function, the data block into the empty space, and writing a second file mark in the second dataset; wherein the empty space of the data storage medium is inaccessible to the first write function of the self-describing format standard.

Abstract: A data storage device may be configured with a transducing head separated from a data storage medium by an air bearing. The transducing head and data storage medium are each contained within a housing. The transducing head can consist of a variable resistance sensor that is connected to a temperature module positioned within the housing. One or more operational variables can be measured by the variable resistance sensor to allow an ambient temperature within the housing to be calculated based on a measured operational variable.

Abstract: Systems and methods for forward corrupted track detection and by-pass are described. In one embodiment, a storage system comprising a storage controller performs a read operation for a target track of a shingled magnetic recording (SMR) disk drive and detects a read operation failure of the read operation for the target track. The storage controller also performs a boundary track read operation on one or more tracks including or adjacent to the target track and detect a forward corruption area based on the boundary track read operation. In another embodiment, a method is provided that includes detecting a read operation failure of a read operation for a track of a disk drive and performing a boundary track read operation on one or more tracks including or adjacent to the target track. The method also includes detecting a forward corruption area based on the boundary track read operation.

Abstract: An apparatus-implemented method according to one embodiment includes detecting an error while writing data to a tape volume on a tape and repositioning the tape in response to detecting the error. A determination whether a rewrite of data associated with the error to the tape volume is allowed is made based on a current position of the tape after the repositioning. The data is rewritten to the tape volume in response to determining that the rewrite of data associated with the error to the tape volume is allowed. A computer program product for protecting overwrite of a tape volume according to another embodiment includes a computer readable storage medium having program instructions embodied therewith, the program instructions readable and/or executable by a controller to cause the controller to perform the foregoing method.

Abstract: A recording medium is written to using an energy source that heats the medium during the writing. A read error in a sector is determined when reading via a read transducer. While traversing a part of the recording medium that includes data, a write coil is activated before attempting to re-read the sector. The energy source does not heat the recording medium sufficiently to change a state of the data during the activation of the write coil. The activation of the write coil removes a magnetic instability of the read transducer.

Abstract: The optical disk device performs recording/reproducing of data by a predetermined recording block on the track of an optical disk. The device has a recording unit, an optical-head, and a failure detection unit. The recording unit generates a recording signal by modulating the data. The optical-head records data on the track by optical beam emission to the track according to the recording signal, and detects light reflected off the track and then generates a detection signal based on the reflected light. The failure detection unit detects an abnormal condition based on the detection signal changed from a normal condition. If the sum of duration of an abnormal condition in the recording block is equal to or greater than a first time-length, the failure detection unit determines that the recording block has a flaw.

Abstract: Some embodiments of the present invention logically eliminate an end region of a user-data area of a magnetic storage tape during formatting (or re-formatting) of the tape, if the position error signal (PES) variance corresponding to the end region exceeds a threshold. An adjacent region, having a PES variance less than the threshold is designated as a new end region, thereby shortening the user-data area of the tape and extending its usable life.

Abstract: An apparatus may include a circuit configured to generate a set of first ADC samples based on a first signal associated with a first read head position and a failed segment and to generate a set of second ADC samples based on a second signal associated with a second read head position and the failed segment. The circuit may then generate, by a MISO equalizer, a set of equalized ADC samples based on the set of first ADC samples and the set of second ADC samples.

Abstract: Systems and methods for forward corrupted track detection and by-pass are described. In one embodiment, a storage system comprising a storage controller performs a read operation for a target track of a shingled magnetic recording (SMR) disk drive and detects a read operation failure of the read operation for the target track. The storage controller also performs a boundary track read operation on one or more tracks including or adjacent to the target track and detect a forward corruption area based on the boundary track read operation. In another embodiment, a method is provided that includes detecting a read operation failure of a read operation for a track of a disk drive and performing a boundary track read operation on one or more tracks including or adjacent to the target track. The method also includes detecting a forward corruption area based on the boundary track read operation.

Abstract: Provided is a management control system for controlling the number of fan revolutions to avoid the number of fan revolutions likely to cause a high frequency of errors in a drive. The management control system includes: an error frequency calculating section for calculating a frequency of errors by acquiring the number of errors occurring in a drive and the number of fan revolutions, and then calculating the number of fan revolutions to avoid based on the frequency of errors; a storage section for storing the number of revolutions to avoid; and a fan revolution number controlling section for acquiring the number of fan revolutions and current ambient temperature in a housing, and controlling the number of fan revolutions within a revolution number range not including the number of revolutions to avoid stored in the storage section, depending on the ambient temperature.

Abstract: First and second different write precompensation values are associated with different first and second non-return-to-zero, inverted (NRZI) data patterns. The first and second different write precompensation values cause a predetermined phase shift to be written into test data that comprises the first and second NRZI data patterns. The test data is mitten to a recording medium of a storage device using the first and second write precompensation value. The test data is used to determine a response of the storage device to the predetermined phase shift.

Abstract: A method comprises writing a waveform on a magnetic recording medium using a heat-assisted magnetic recording apparatus which includes a laser. The method also comprises reading back the waveform from the medium, and detecting one or more transition shifts in the readback waveform indicative of a mode hop of the laser. The method further comprises measuring a metric of the one or more transition shifts.

Abstract: A slider of a magnetic recording head includes a plurality of electrical bond pads and a plurality of readers comprising at least a first reader and a second reader. Each of the readers is coupled to a different pair of electrical bond pads. A temporary contact sensor is provided on the slider and coupled between a bond pad of the first reader and a bond pad of the second reader. The temporary contact sensor is configured for operation during a certification process of the apparatus and to become inoperable after completion of the certification process.

Abstract: In one embodiment, a system for processing data includes a processor and logic integrated with and/or executable by the processor. The logic is configured to detect and track positive peak amplitudes and negative peak amplitudes of a readback waveform during data reading using a tracking threshold module, and to detect and track positive peak amplitudes and negative peak amplitudes of the readback waveform during the data reading at an input to an equalizer using a second tracking threshold module in response to reading a data set separator (DSS). Moreover, the logic is configured to perform asymmetry compensation on the data using an asymmetry compensator in an asymmetry compensation loop based on input from the tracking threshold module when not reading a DSS and based on input from the second tracking threshold module when reading a DSS, an output of the asymmetry compensator being provided to the equalizer.

Abstract: Various embodiments of a magnetic stack are disclosed. In one or more embodiments, the magnetic stack includes first and second shield layers, and a magnetically responsive lamination disposed between the first and second shield layers. The magnetically responsive lamination can be configured to receive a sense current IS therethrough. The magnetic stack also includes a cooling element disposed between the first and second shield layers and thermally coupled to the magnetically responsive lamination. The cooling element can be configured to receive a bias current IB therethrough. And the cooling element can be configured to cool the magnetically responsive lamination during a read function.

Abstract: A method includes moving a heat-assisted magnetic recording head relative to a magnetic recording medium comprising a plurality of tracks, the head comprising a reader and a writer including a near-field transducer (NFT) optically coupled to a laser diode, the writer comprising a center which is laterally offset relative to a center of the reader to define a writer-reader offset (WRO) therebetween. Patterns are written to a particular track at a plurality of laser diode current levels. The patterns are read and a WRO value is calculated at a peak amplitude position for each of the laser diode current levels. A slope of the WRO values is determined with the laser current diode levels. A health condition of the NFT is determined by determining if the slope is greater than a predetermined threshold indicative of non-uniform activation across the NFT.

Abstract: Before writing to a heat-assisted magnetic recording medium, a current of a laser is modulated about a default threshold current level. A modulation level of an optical power sensor is measured, the optical power sensor being coupled to detect optical output of the laser in response to the modulated current. A bias current for subsequent activation of the laser is adjusted based on the modulation level of the optical power sensor.

Abstract: A serial communication circuit includes a receiving unit configured to serially receive input data including a command and a synchronization identification code that is different from the command and a determining unit configured to receive the synchronization identification code from the receiving unit and when the synchronization identification code coincides with a slave selection value, to instruct a start of response processing based on the command.

Abstract: A hard disk drive device and a method and apparatus for control of the hard disk drive is provided. The hard disk drive includes disk media, a slider head, a head gimbal assembly and a control means. The disk media includes at least two layers for data storage. The slider head flies above the disk media and includes a writer and a reader, and a head gimbal assembly supports the slider head above the disk media. The control means is physically coupled to the head gimbal assembly and electrically coupled to the writer and the reader for reducing write interference from the writer when the writer is writing to the disk media while the reader is reading from the disk media, wherein write interference is reduced in one or more of a time domain and a frequency domain.

Abstract: A method comprises writing a waveform on a magnetic recording medium using a heat-assisted magnetic recording apparatus which includes a laser. The method also comprises reading back the waveform from the medium, and detecting one or more transition shifts in the readback waveform indicative of a mode hop of the laser. The method further comprises measuring a metric of the one or more transition shifts.

Abstract: The disclosed technology provides techniques for mitigating write-to-write bit error rate fluctuations that decrease accuracy of write precompensation (WPC) tuning. According to one implementation, such write-to-write bit error rate fluctuations are mitigated if a predetermined pattern is written at a particular radial offset from a target data track prior to testing a WPC register in association with the target data track. Selection of the particular radial offset can be performed according to an iterative offset track clean-up disclosed herein.