Abstract: Systems, methods, devices, circuits for data processing, and more particularly to data processing including operational marginalization capability, and/or operational improvement capability.

Abstract: Each of unit blocks (UB1, UB2) is provided with an output circuit (20) including a serial circuit of FETs (21) and (22). A power supply circuit (1b) can operate in a first mode for generating an output voltage (Vo) using only one of the output circuits (20) or in a second mode for generating the output voltage (Vo) using two output circuits (20) by synchronous/parallel driving. When switching from the first mode to the second mode, start of the synchronous/parallel driving from a state where the FET (22) on the low voltage side is turned on is inhibited (start of the synchronous/parallel driving is waited until the FET (21) on the high voltage side is turned on).

Abstract: According to one embodiment, a data reproduction apparatus includes a decoder, a cancellation process module and a calculator. The cancellation process module cancels, from equalized-waveform data of a read signal, the interference between a signal read from a first track and a signal read form a second track adjacent to the first track. The calculator calculates, for a specific window, a first cancellation coefficient necessary to cancel the interference. The calculator further calculates a second cancellation coefficient by correcting the first cancellation coefficient based on a ratio of the number of adjacent bits of opposite polarity to the number of all bits in the specific window.

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

Abstract: Misalignment of a transducer head over a bit-patterned media (BPM) may cause a bit to experience conflicting magnetization forces from the writer, resulting in improperly written data and stored data corruption. The likelihood of data corruption is reduced when a write transition is performed when the write sync margin is increased or maximized. Therefore, a write precompensation system may calculate time shift information for adjusting the timing of an individual write current transition at the transducer that compensates for write sync margin degradation due to any or all of skew angle of the transducer, track misregistration, and write field curvature.

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 failure prediction system for performing failure prediction to a monitoring target device by detecting a state, comprising: a state detection unit for detecting state signals of no smaller than two different kinds, and outputting a detection signal corresponding to each of the state signals; a phase processing part for synchronizing a plurality of the detection signals; a signal analysis part for calculating a feature value indicating a feature of the state for each of the detection signals from the phase processing part; and a failure prediction part for performing failure prediction of the monitoring target device for each of the feature values by comparing the feature value in question and a reference value set in advance.

Abstract: A system is described for constructing maximum transition run modulation code based upon a multi-level run-length limited finite state machine. A processor is configured to receive information from a hard disk drive via a read channel and recover data from the hard disk drive using maximum transition run 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 a maximum transition run modulation code to mimic the optimized Markov source based upon a finite state machine having a limited transition run length and a multi-level periodic structure.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. As an example, a data processing circuit having a data detection circuit is disclosed that includes: a scaling circuit, a soft output calculation circuit, and a factor calculation circuit. The scaling circuit is operable to scale a branch metric value by a scaling factor to yield a scaled output. The soft output calculation circuit is operable to calculate a soft output based at least in part on the scaled output. The factor calculation circuit operable to modify the scaling factor based at least in part on the soft output.

Abstract: Systems, methods, devices, circuits for data processing, and more particularly to data processing including operational marginalization capability.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. As an example, a data processing circuit is disclosed that includes: a data decoder circuit and a local iteration adjustment circuit. The data decoder circuit is operable to perform a number of local iterations on a decoder input to yield a data output. The local iteration adjustment circuit is operable to generate a limit on the number of local iterations performed by the data decoder circuit.

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: Systems, methods, devices, circuits for data processing, and more particularly to data processing including operational marginalization capability.

Abstract: A method of writing servo data to a data storage medium includes reading a servo instruction from a memory, the servo instruction comprising a control portion and a data portion, processing the servo instruction in a controller to generate a servo data pattern from the data portion based on the control portion, and transferring the servo data pattern to the data storage medium. The processing may include transforming the data portion into the servo data pattern based on the control portion. The processing also may include following a command in the control portion to use the data portion as an index to retrieve a pre-programmed servo data pattern from a pattern store. The transferring may include storing the servo data pattern in a buffer, and writing the servo data pattern from the buffer to the data storage medium.

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: 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 detecting patterns in a data stream.

Abstract: A modulated signal of a predetermined frequency is applied to a capacitive sensor of a magnetic head. The capacitive sensor is located proximate to a media-facing surface of the magnetic head. A clearance between the magnetic head and a magnetic medium is determined using a response to the modulated signal at the predetermined frequency.

Abstract: Systems and methods for making fast measurements of channel performance metrics such as error margin and off-track recording capability in shingled magnetic recording are provided. One such method involves writing a plurality of shingled tracks on the disk, measuring an off track read capability (OTRC) of each of the plurality of shingled tracks, determining radial endpoints of the measured OTRC for each of the plurality of shingled tracks, determining an approximate radial center for each of the plurality of shingled tracks based on the respective OTRC radial endpoints, and measuring a channel performance metric at a range centered around the approximate radial center for each of the plurality of shingled tracks. In one such case, the channel performance metric involves error margin. One such system includes a processor coupled to a memory, a magnetic transducer, and a test platform, where the processor is configured to perform the method.

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: Servo channel noise limits are defined through Viterbi decisions based on servo gate signals. Y values are used to produce a first Viterbi decision at each servo gate. Viterbi decisions and Y values are used to produce ideal Y values. Y values and ideal Y values are used to produce an error value which is adjusted by a noise factor based on estimated channel characteristics. The noise value is combined with Y values and used to produce a second Viterbi decision at each servo gate.

Abstract: A fly height control circuit includes an input node to receive a digital control signal, an output node to output a control current to a resistive heater element to adjust a spacing between a read/write head and a surface of a storage medium, and control circuitry to process the digital control signal and generate the output control current based on the digital control signal. The control circuitry generates a first reference current based at least in part on the control current output from the output node. The control circuitry controls a slew rate of the first reference current to generate a slew rate controlled reference current. The control circuitry generates a second reference current based on a feedback voltage at the output node. The control circuitry compares the slew rate controlled reference current with the second reference current to adjust the control current output from the output node.

Abstract: Hardware-based methods and apparatus are provided for inter-track interference mitigation in magnetic recording systems. Inter-track interference (ITI) cancellation data is stored in a memory of a read channel of a magnetic recording system. The memory can be in a write data path or a read data path of the read channel. The inter-track interference cancellation data is optionally provided to an inter-track interference mitigation circuit using at least a portion of a write data path, for example, based on a control signal. The storage of the inter-track interference cancellation data can be in response to a second control signal.

Abstract: A write head for a magnetic storage device includes a writing tip comprising a magnetic material, a write pulse generator configured to generate a write pulse signal comprising a varying voltage bias between the magnetic storage device and the writing tip. The write pulse signal comprising one or more write pulses effective to tunnel electrons from the writing tip to the magnetic storage device. The data stream generator configured to provide a data stream signal to the writing tip where the data stream signal is operative to vary spin polarity in the electrons from a first polarity to a second polarity.

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

Abstract: A method and system for estimating a zero gain start (ZGS) bias in a read channel is disclosed. The method may include: receiving preamble samples within a fixed-length window selected for ZGS calculation; calculating an energy associated with a 2T frequency in the preamble samples; calculating an energy associated with non-2T frequencies in the preamble samples; and calculating the ZGS bias based on the energy associated with the 2T frequency in the preamble samples and the energy associated with non-2T frequencies in the preamble samples.

Abstract: A perpendicular magnetic recording disk has servo regions that have a patterned underlayer with seed layer pillars formed on the underlayer pillars above the underlayer trenches. The underlayer is made of an oxidizable material. Magnetic recording material is located on the seed layer pillars and on an oxide layer in the underlayer trenches. The magnetic material in the trenches exhibits a magnetic field substantially less than the magnetic field exhibited by the magnetic material on the seed layer pillars, which has perpendicular magnetic anisotropy. The reduced magnetic field from the trenches results from structural differences between the magnetic material on the seed layer pillars and in the trenches, such as smaller grain size of the magnetic material on the seed layer pillars and a wider distribution of crystallographic axes of the magnetic material in the trenches. The seed layer may be made of a material substantially non-reactive with oxygen.

Abstract: A modified soft output Viterbi algorithm (SOVA) detector receives a sequence of soft information values and determines a best path and an alternate path for each soft information value and further determines, when the best and alternate paths lead to the same value for a given soft information value, whether there is a third path departing from the alternate path that leads to an opposite decision with respect to the best path for a given soft information value. The SOVA detector then considers this third path when updating the reliability of the best path. The modified SOVA detector achieves max-log-map equivalence effectively through the Fossorier approach and includes modified reliability metric units for the first N stages of the SOVA detector, where N is the memory depth of a given path, and includes conventional reliability metric units for the remaining stages of the detector.

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: A plasmon generator of a thermally-assisted magnetic recording head has a first configuration member having a near-field light generation end surface at an ABS, and a second configuration member being in contact with main magnetic pole, and terminating at a front end portion of a slope positioned at the position recessed from the ABS. An end part of a separator layer, which is interposed between the main magnetic pole and the first configuration member, on a side opposite to the ABS is at a position more recessed from the air bearing surface than the front end portion of the slope of the second configuration member.

Abstract: Systems, methods, and other embodiments associated with a data detector that processes signals read from a storage device are described. According to one embodiment, a detector for detecting a data signal embedded in a read signal from a storage device includes a signal estimator configured to generate an estimate of the control signal from the read signal by sampling the read signal to determine characteristics of the control signal. The read signal includes the data signal and the control signal. The signal estimator uses the characteristics to calculate the estimate of the control signal. The detector also includes a cancellation unit configured to produce the data signal by cancelling the estimate of the control signal from the read signal.

Abstract: Aspects of the disclosure pertain to a system and method for providing zero gain start (ZGS) and gain acquisition based on an adaptive analog-to-digital converter (ADC) target. The adaptive ADC target is used to collect channel characteristics and based on the adaptive ADC target, an adjusted 2T amplitude target value is generated.

Abstract: Systems, methods, devices, circuits for data processing, and more particularly to systems and methods for adapting noise predictive filters for inter-track interference cancellation in a data processing system.

Abstract: Various embodiments of the present invention provide systems and methods for estimating noise components in a received signal set. For example, one embodiment of the present invention provides a noise estimation circuit that includes a data detector circuit and a noise component calculation circuit. The data detector circuit receives a series of data samples and provides a detected output, and the noise component calculation circuit provides an electronics noise power output and a media noise power output each calculated based at least in part on the detected output and the series of data samples.

Abstract: An apparatus comprises read channel circuitry and signal processing circuitry associated with the read channel circuitry. The signal processing circuitry is configured to: equalize an oversampled digital data signal to determine an equalized digital data signal, filter the equalized digital data signal, determine a hard decision and reliability of the filtered digital data signal, and decode the filtered digital data signal based at least in part on the hard decision and reliability. The oversampled digital data signal comprises a first set of sampled digital data and a corresponding second set of sampled digital data, each of the samples in the first set of sampled digital data being offset from a corresponding one of the sample in the second set of sampled digital data by a phase difference.

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 decoder 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: Methods and apparatus are provided for detecting a sync mark in a storage system, such as a hard disk drive. A sync mark is detected in a storage system by obtaining one or more branch metrics from a data detector in the storage system; generating one or more sync mark metrics using the one or more branch metrics from the data detector; and identifying the sync mark based on the sync mark metrics. An input data set is optionally compared with a plurality of portions of a sync mark pattern to yield corresponding comparison values and the comparison values can be summed to obtain at least one result. A sync mark found signal is asserted based upon the at least one result.

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: In one embodiment, a method includes passing a signal through an adaptive noise whitening filter, wherein one or more noise whitening coefficients used in the noise whitening filter are updated using a noise whitening filter coefficient updater, wherein the noise whitening filter is configured to process the signal according to a transfer polynomial: W(D)=1?(p1D+ . . . p??·D??), where p1 . . . p?? are noise whitening coefficients, where a tape channel is characterized by a transfer polynomial F(D)=1+f1D+ . . . +fLDL where D is delay corresponding to bit duration, with 2L being a number of states of the tape channel, wherein a soft detector has a total of 2L+? states, the noise whitening filter comprises 2?? states, ?? is greater than ?, L represents a memory length of the tape channel, and ? represents a memory length of the noise whitening filter.

Abstract: In accordance with one embodiment, a computer program product includes a computer readable storage medium having computer readable program code that is readable and/or executable by a processor to: receive a signal including precoded data read from a magnetic tape medium and pass the signal through a soft detector to calculate first soft information about each bit of the signal and to provide adaptive compensation for the precoded data, send the first soft information to a soft decoder, pass the signal through the soft decoder to calculate second soft information about each bit of the signal, and send the second soft information to the soft detector, wherein the precoded data is passed through at least one precoder prior to being written to the magnetic tape medium via a precoder that applies 1/(1?D2) to bits of data, where D is delay corresponding to bit duration.

Abstract: In one embodiment, a method includes passing a signal through a noise whitening filter, passing the signal through a soft detector to calculate first soft information, passing the signal through the soft decoder to calculate second soft information based on the first soft information, and sending the second soft information to the soft detector, wherein the noise whitening filter is configured to process the signal according to the following transfer polynomial: W(D)=1?(p1D+ . . . . p1D?), where p1 . . . p? are noise whitening coefficients, D is delay corresponding to bit duration, and a transfer polynomial of the tape channel is F(D)=1+f1D+ . . . +fLDL, wherein L represents a memory length of the tape channel, and wherein ? represents a memory length of the noise whitening filter. Other methods, systems, and computer program products are described in more embodiments.

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 system including an analog front end module, an equalizer module, a detector module, and a gain module. The analog front end module is configured to sample a signal read from a storage medium, convert the sampled signal into a digital signal, and output the digital signal. The equalizer module is configured to equalize the digital signal and output a data vector that corresponds to the equalized digital signal. The data vector represents data in the signal read from the storage medium. The detector module is configured to output a decision vector that corresponds to a noise-free ideal output vector of the decoded data vector. The gain module is configured to calculate a gain value based on the decision vector and the data vector, apply the gain value to the data vector, and output a revised data vector based on the data vector and the applied gain value.

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: An adaptive detector, such as a maximum a posteriori (MAP) detector for a read channel, is disclosed. In one or more embodiments, a data processing apparatus, such as a read channel digital front end, includes an equalizer configured to equalize X sample data to yield equalized Y sample data. A noise predictive filter configured to receive the equalized Y sample data yielded by the equalizer is operable to filter noise in the equalized Y sample data. A detector is configured to perform iterative data detection on the filtered equalized Y sample data. The detector is operable to program a branch metric, a variance, and a scaling factor for equalizer adaptation during a global iteration of the detector.

Abstract: In accordance with one embodiment, a data storage system includes a tape channel for reading precoded data from a magnetic tape medium to produce a signal, a soft detector adapted for calculating first soft information about each bit of the signal and sending the first soft information to a soft decoder, and the soft decoder positioned subsequent to the soft detector, the soft decoder being adapted for calculating second soft information about each bit of the signal and sending the second soft information to the soft detector, wherein the precoded data includes a characteristic of being passed through at least one precoder prior to being written to the magnetic tape medium, and wherein the soft detector provides automatic compensation for the precoded data. Other systems, methods, and computer program products for reading data using an adaptive soft-output detector are described according to more embodiments.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. For example, a data processing system is disclosed that includes: a data detector circuit, a filter circuit, and a mean squared calculation circuit. The data detector circuit is operable to apply a data detection algorithm to a data set to yield a detected output. The filter circuit is operable to filter the detected output to yield a filtered output. The mean squared calculation circuit is operable to calculate a mean squared error value based at least in part on the data set and the filtered output. A quality indicator is generated at least in part on the mean squared error value.

Abstract: Determining a polarity of a piezoelectric (PZT) actuator of a disk drive including a disk for storing data and a head for reading and writing data. A test signal is injected into the PZT actuator and a position signal is received which indicates a position of the head over the disk resulting from the test signal. A test compensation signal is generated based on the received position signal and the polarity of the PZT actuator is determined based on a phase of the generated test compensation signal.

Abstract: Disclosed is a writing control device including: a storing unit comprising N HDDs, N being an integer which is 2 or more; a data division unit configured to divide data to be written in the storing unit into N unequal division data; and a writing control unit configured to dispersedly store the N division data in the N HDDs in parallel, wherein the N division data include a first division data and a second division data having a larger data size than the first division data, and the writing control unit writes the second division data in tracks of a portion of the HDD, which is positioned on an outer side than a portion in which the first division data is written.