Lsi Corporation

Avago Technologies General IP (singapore) Pte. Ltd.

Eui Seok Hwang

George Mathew

Richard Rauschmayer

Xiufeng Song

Shaohua Yang

Bruce Alexander Wilson

Jongseung Park

Ivana Djurdjevic

Suharli Tedja

A method of operating a multi-reader two-dimensional magnetic recording system includes determining a position of a multi-reader head of the multi-reader two-dimensional magnetic recording system, determining an areal density push according to the position of the multi-reader head, and performing an operation to read data from or write data to a magnetic recording medium according to the areal density push.

Reader separation dependent linear and track density push for array reader based magnetic recording

A method for enhancing read performance in an ARMR system includes: obtaining CTS information for a plurality of readers in a multi-reader head of the ARMR system, the CTS information defining a relationship between skew angle and CTS between respective combinations of subsets of the readers; determining, as a function of the CTS information, a subset of the readers which provides enhanced read performance among the readers for each of a plurality of skew angles; assigning a weight value to each of a plurality of read signals generated by a corresponding one of the readers for each of the skew angles, the weight value being indicative of a performance of the corresponding one of the readers relative to one another; and decoding information read from at least one target track of a magnetic storage medium being read as a function of the read signals and corresponding weight values.

Skew-tolerant multiple-reader array in array-reader based magnetic recording

A method of mitigating an effect of track misregistration on read performance in a system comprising an array-reader includes determining an estimated off-track condition, selecting translation coefficients based on the estimated off-track condition, determining updated equalizer coefficients by applying the translation coefficients to native equalizer coefficients, and applying the updated equalizer coefficients to signals received from the array-reader to output a read signal.

Track misregistration sensitive initialization of joint equalizer

A method for enhancing read performance in a multi-reader two-dimensional magnetic recording system comprising first and second readers includes: receiving first and second analog read signals from the first and second readers, respectively; sampling the first and second analog read signals to generate first and second sampled signals, respectively, each of the first and second sampled signals comprising an integer component, indicative of a value of a corresponding one of the first and second analog read signals, respectively, at an integer multiple of a corresponding sampling period associated therewith, and/or a fractional component, indicative of a value of the corresponding one of the first and second analog read signals, respectively, at an arbitrary point in time between integer multiples of the corresponding sampling period; and combining the integer and/or fractional components of the respective first and second sampled signals to thereby generate a reader offset estimation signal.

Two-dimensional magnetic recording reader offset estimation

Systems, methods, devices, circuits for data processing, and more particularly to systems and methods for processing skew tolerant processing of data derived from multiple read heads.

Systems and methods for skew tolerant multi-head data processing

A magnetic recording system includes an array of analog inputs operable to receive analog signals retrieved from a magnetic storage medium, a modulator operable to combine the analog signals to yield a frequency division multiplexed signal, a demodulator operable to yield a plurality of demodulated signals from the frequency division multiplexed signal corresponding to each channel of the array, and a joint equalizer operable to filter the plurality of demodulated signals to yield an equalized output.

Array-reader based magnetic recording systems with frequency division multiplexing

Systems and method relating generally to data processing, and more particularly to systems and methods for confirming data validity. In one case, a system is disclosed that includes an adjacent track interference confirmation circuit. The adjacent track interference confirmation circuit is operable to receive an indication of an adjacent track interference; determine a causal connection between the adjacent track interference and a mis-alignment of a read head and a track on a storage medium from which a data set corresponding to the indication of the adjacent track interference is derived; and provide a re-write signal where even after reduction of the mis-alignment the indication of adjacent track interference repeats.

Systems and methods for adjacent track interference based re-writing

A method for enhancing read performance in an ARMR system includes: obtaining CTS information for a plurality of readers in a multi-reader head of the ARMR system, the CTS information defining a relationship between skew angle and CTS between respective combinations of subsets of the readers; determining, as a function of the CTS information, a given one of the combinations of subsets of the readers which provides enhanced read performance among a total number of combinations of subsets of the readers for each of a plurality of skew angles; and selecting, for subsequent processing by a read channel in the ARMR system, the given one of the combinations of subsets of the readers determined to provide enhanced read performance for a given one of the skew angles corresponding to a zone in which the multi-reader head is operating.

Skew-tolerant reader set selection in array-reader based magnetic recording

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

System and method for generating soft-orthogonal syncmarks

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

Systems and methods for data dependent inter-track interference cancellation

A data processing system includes an analog to digital converter operable to sample an analog signal obtained from a magnetic storage medium to yield digital samples, and a sync mark detector operable to search for a particular one of a number of sync marks in the digital samples. Each of the data tracks on the magnetic storage medium is associated with one of the sync marks. The sync mark on each of the data tracks has a different pattern than the sync marks on neighboring tracks.

Sync mark system for two dimensional magnetic recording

A method for enhancing read performance in an ARMR system includes: obtaining a first reader offset profile corresponding to a first reader of a multi-reader array head in the ARMR system; obtaining at least a second reader offset profile corresponding to at least a second reader of the multi-reader array head in the ARMR system; combining the first and second reader offset profiles to generate a combined reader offset profile; and controlling a location of the multi-reader array head in the ARMR system relative to at least one target track associated with a magnetic storage medium to be read as a function of a peak amplitude of the combined reader offset profile.

Skew-tolerant reader configurations using cross-track profiles for array-reader based magnetic recording

A data processing circuit includes a long magnet identification circuit operable to identify long magnet bits in data to be processed, the long magnet bits comprising bits having a same value as a number of preceding and subsequent bits, an error calculation circuit operable to subtract an ideal version of the long magnet bits from the long magnet bits to yield an error signal, an adjacent track interference metric calculation circuit operable to calculate an adjacent track interference metric based on the error signal, and a comparator circuit operable to compare the adjacent track interference metric with a threshold value and to assert a refresh signal when the adjacent track interference metric is greater than the threshold value.

Data processing system with adjacent track interference metric

A data processing system includes a cross-correlation calculator operable to calculate cross-correlations between an input signal and each of three different sync patterns associated with a target track and neighboring tracks, a detector operable to select a largest of the cross-correlations, a threshold comparator operable to compare the cross-correlations with a threshold to determine a direction of any position error of a read head, and a position error estimator operable to estimate a position error of the read head based at least in part on the cross-correlations.

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Palo Alto, CA, United States of America

Eui Seok Hwang