Lsi Corporation

Avago Technologies General IP (singapore) Pte. Ltd.

Dahua Qin

Haitao Xia

Xun Zhang

Shaohua Yang

Ming Jin

Lu Lu

Zhi Bin Li

Jianzhong Huang

Yao Zhao

Mark D Thornley

Linjiang Guo

Improved pattern detection is provided for a predefined pattern in data. A detection threshold employed by a Euclidean detector to detect a pattern (such as a Servo Address Mark) may be adjusted based upon data gathered that corresponds to an indication of a detected pattern by one of a plurality of pattern detectors.

Methods and apparatus for improved pattern detection

An apparatus for detecting media flaws includes a branch metric selection circuit operable to select a first branch metric and a second branch metric, a subtraction circuit operable to subtract the second branch metric from the first branch metric to yield a difference, and a comparator operable to compare the difference with a threshold value and to indicate a presence of a potential flaw in a storage medium when the difference is less than the threshold value.

Systems and methods for detecting media flaws

A servo system includes a detector circuit operable to apply a data detection algorithm to digital data to yield hard decisions, a convolution circuit operable to yield ideal digital data based on the hard decisions and on target values, a subtraction circuit operable to subtract the ideal digital data from the digital data to yield an error signal, a scaling circuit operable to scale the error signal to yield a scaled noise signal, an adder operable to add the scaled noise signal to the digital data to yield noise-added digital data, and a second detector circuit operable to apply a second data detection algorithm to the noise-added digital data to yield output hard decisions.

Servo system with signal to noise ratio marginalization

A hard disk drive uses a second, reference burst field in a preamble to estimate burst phase and burst magnitude. Such estimations are used for position error signal integration and repeatable runout correction. Gain error is also derived from such estimations. Information contained in a preamble field is used in conjunction with the reference burst phase estimation to synchronize servo address marks.

Hardware support of servo format with two preamble fields

Sliding-window based data processing includes receiving an analog signal, converting the analog signal to a series of digital samples synchronous to a sampling clock, performing a first discrete Fourier transform on a first portion of the series of digital samples, performing a second discrete Fourier transform on a second portion of the series of digital samples, performing a third discrete Fourier transform on a third portion of the series of digital samples, generating a first series of zero phase start values by calculating a zero phase start value based on the first discrete Fourier transform in a sliding-window at a series of time increments across the servo preamble, storing the zero phase start values, and averaging the stored zero phase start values at the end of the servo preamble.

Method and system for sliding-window based phase, gain, frequency and DC offset estimation for servo channel

Various embodiments of the present invention provide systems and methods for data processing. For example, a data processing system is discussed that includes: an equalizer circuit, a signal to noise ratio calculation circuit, and a parameter adjustment circuit. The equalizer circuit is operable to equalize a data input to yield an equalized output. The signal to noise ratio calculation circuit is operable to calculate a signal to noise ratio of the equalized output based at least in part on a noise power derived from the equalized output. The parameter adjustment circuit is operable to adjust a parameter based at least in part on the signal to noise ratio.

Systems and methods for SNR measurement using equalized data

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

Systems and methods for burst demodulation

Various embodiments of the present invention provide systems and methods for data processing. As an example, a data processing system is disclosed that includes Various embodiments of the present invention provide data processing systems that include an analog to digital converter circuit and a phase and gain computation circuit. The analog to digital converter circuit is operable to convert an analog input into a series of digital samples. At least a portion of the series of digitals samples represent a periodic signal from a servo data region. The phase and gain computation circuit is operable to: determine an approximate amplitude of the periodic signal based at least in part upon the digital samples representing the periodic signal from the servo data region; determine a gain based at least in part on the approximate amplitude; and determine a phase based at least in part on the approximate amplitude.

Systems and methods for zone servo timing gain recovery

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 noise predictive filter circuit, a data detector circuit, and a first and a second pattern dependent adaptive target circuits. The noise predictive filter circuit includes at least a first pattern dependent filter circuit operable to perform noise predictive filtering on a data input for a first pattern using a first adaptive target to yield a first noise predictive output, and a second pattern dependent filter circuit operable to perform noise predictive filtering on the data input for a second pattern using a second adaptive target to yield a second noise predictive output. The data detector circuit is operable to apply a data detection algorithm to the first noise predictive output and the second noise predictive output to yield a detected output. The first pattern dependent adaptive target circuit is operable to adaptively calculate the first adaptive target based at least in part on the first noise predictive output and a training sequence. The second pattern dependent adaptive target circuit operable to adaptively calculate the second adaptive target based at least in part on the second noise predictive output and the training sequence.

Systems and methods for pattern dependent target adaptation

Various embodiments of the present inventions provide systems and methods for adaptive servo address mark detection.

Adaptive servo address mark detection

The present inventions are related to systems and methods for transferring information to and from a storage medium, and more particularly to systems and methods for positioning a sensor in relation to a storage medium. For example, an apparatus for determining a sensor position is disclosed that includes a data stream processor operable to generate a number of data streams at different frequencies based on an input data stream, a number of servo preamble detectors each operable to process a different one of the data streams to detect a servo preamble, a selector operable to output one of the data streams in which the servo preamble was detected as a winning data stream, and a pattern detector operable to detect a pattern in the winning data stream.

Multi-zone servo processor

The present inventions are related to systems and methods for transferring information to and from a storage medium, and more particularly to systems and methods for positioning a sensor in relation to a storage medium. For example, an apparatus for determining a sensor position is disclosed that includes discrete Fourier transform calculators operable to process input data to yield a magnitude response of the input data at each of a number of candidate frequencies, a comparator operable to compare the magnitude responses to yield a winning candidate frequency, a servo controller operable to process at least one servo field in the input data to identify a position of a sensor based on the at least one servo field, and a servo frequency synthesizer operable to establish a frequency of operation in the servo controller based at least in part on the winning candidate frequency.

Servo zone detector

Various embodiments of the present invention provide systems and methods for data processing. As an example, a pattern detection circuit is discussed that includes a distance calculation circuit and a comparator circuit. The distance calculation circuit is operable to calculate a noise whitened distance between a reference signal and a received input to yield a comparison value. The comparator circuit is operable to compare the comparison value with a threshold value.

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Allentown, PA, United States of America

Dahua Qin