Patent application number | Description | Published |
20100142078 | Systems and Methods for Memory Efficient Repeatable Run Out Processing - Various embodiments of the present invention provide systems and methods for low overhead disk wobble compensation. As an example, a method for performing synchronous wobble compensation processing is disclosed. The method includes providing a medium that includes a servo data region and a user data region. The servo data region includes a clock recovery pattern and a location pattern. A detectable pattern is written to the user data region a known number of bit periods from the location pattern. The detectable pattern is read back, and a fractional processing delay is calculated. Based at least on the fractional processing delay and a known number of bit periods from the location pattern to the end of the servo data region, a wobble compensation pattern is written an integral number of bit periods from the location pattern. | 06-10-2010 |
20120026620 | METHODS AND APPARATUS FOR GAIN ESTIMATION USING SERVO DATA WITH IMPROVED BIAS CORRECTION - Methods and apparatus are provided for gain estimation using servo data with improved bias correction. The gain is estimated using a preamble in a servo sector by obtaining a first gain estimate using a first gain estimation algorithm (such as a Zero Gain Start Algorithm) and a first portion of the preamble; storing the first portion of the preamble in a memory buffer; obtaining a second gain estimate using a second gain estimation algorithm (such as a Zero Forcing algorithm) and the first portion of the preamble; and processing Servo Address Mark (SAM) and Gray data in the servo sector using the first gain estimate substantially simultaneous to the step of obtaining the second gain estimate. A gain error can be obtained by calculating a difference between the first gain estimate and the second gain estimate. The gain error can be used in burst processing of the servo data. | 02-02-2012 |
20120033323 | Systems and Methods for Servo Data Based Harmonics Calculation - Various embodiments of the present invention provide systems and methods for servo data based harmonics calculation. For example, a circuit for determining harmonics is disclosed that includes an analog to digital conversion circuit that provides a series of digital samples corresponding to a pattern within a servo data region of a storage medium, and a harmonic calculation circuit. The harmonic calculation circuit is operable to calculate a first harmonic value for the series of digital samples, calculate a second harmonic value for the series of digital samples, and calculate a ratio of the first harmonic value to the second harmonic value. | 02-09-2012 |
20120182643 | Systems and Methods for Reduced Format Data Processing - Various embodiments of the present invention provide systems and methods for data processing. For example, some embodiments of the present invention provide data processing circuits that include a variable gain amplifier circuit, an analog to digital conversion circuit, a cosine component calculation circuit, a sine calculation circuit, and a zero gain start calculation circuit. The variable gain amplifier circuit is operable to apply a gain to a data input corresponding to a gain feedback value and providing an amplified output. The analog to digital conversion circuit is operable to convert the amplified output to a corresponding series of digital samples. The cosine component calculation circuit is operable to calculate a cosine component from the series of digital samples, and the sine component calculation circuit operable to calculate a sine component from the series of digital samples. The zero gain start calculation circuit is operable to calculate a raw gain error value based on the cosine component and the sine component, where the gain feedback value is derived from the raw gain error value. | 07-19-2012 |
20120281305 | Systems and Methods for Servo Data Detection - 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 codeword detector circuit operable to apply a codeword based data detection algorithm to a data input corresponding to an encoded servo data region to yield a detected output, and a servo address mark processing circuit operable to identify a pre-defined pattern in the detected output. | 11-08-2012 |
20120303327 | Systems and Methods for Pattern Detection - Various embodiments of the present invention provide systems and methods related to pattern detection. As an example, a system for sample selection is disclosed that includes a difference calculation circuit, a comparator circuit, and an output selector circuit. The difference calculation circuit is operable to calculate a first difference between a first value corresponding to a first digital sample and a second value corresponding to a second digital sample, and to calculate a second difference between a third value corresponding to a third digital sample and a fourth value corresponding to a fourth digital sample. The comparator circuit is operable to compare the first difference with the second difference to yield a comparison output. The output selector circuit is operable to select one of the second value and the fourth value as an output based at least upon the comparison output. | 11-29-2012 |
20130107687 | METHODS AND APPARATUS FOR VALIDATING DETECTION OF RRO ADDRESS MARKS | 05-02-2013 |
20130329312 | 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 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. | 12-12-2013 |
20130329313 | Servo Zone Detector - 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. | 12-12-2013 |
20140139939 | ADAPTIVE SERVO ADDRESS MARK DETECTION - Various embodiments of the present inventions provide systems and methods for adaptive servo address mark detection. | 05-22-2014 |
20140146413 | Systems and Methods for Enhanced Servo Data Processing - Systems and method relating generally to detecting information, and more particularly without limitation to systems and methods for synchronizing to a data stream. | 05-29-2014 |
20140233128 | Systems and Methods For Burst Demodulation - 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. | 08-21-2014 |
20140268397 | Hardware Support of Servo Format with Two Preamble Fields - 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. | 09-18-2014 |
20140331108 | Systems and Methods for Detecting Media Flaws - 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. | 11-06-2014 |
20140340780 | Method and System for Sliding-Window Based Phase, Gain, Frequency and DC Offset Estimation for Servo Channel - 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. | 11-20-2014 |