| Patent application number | Description | Published |
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| 20090089612 | SYSTEM AND METHOD OF REDUNDANTLY STORING AND RETRIEVING DATA WITH COOPERATING STORAGE DEVICES - A system and method for data storage in an array. A system includes a client coupled to a storage subsystem. The storage subsystem comprises data storage locations addressable as rows and columns in an array. Each column comprises a separate storage device. Each row includes redundant data. For a given row, a coordinating storage device receives data from the client, coordinates computation and storage of redundant data, and forwards data to other storage devices. In response to receiving data targeted for storage in a given storage location, a non-volatile, temporary storage device that is associated with the separate storage device that includes the given storage location buffers the received data. The coordinating storage device conveys a write completion message to the client in response to detecting that the data has been buffered in the non-volatile, temporary storage devices. At least two storage devices are coordinating storage devices in separate rows. | 04-02-2009 |
| 20090154003 | Systems and Methods for Using an On-the-fly CBD Estimate to Adjust Fly-Height - Various embodiments of the present invention provide systems and methods for using channel bit density estimates to adjust fly-height. For example, various embodiments of the present invention provide methods for adaptively adjusting fly-height. Such methods include providing a storage medium that includes information corresponding to a process data set, and a read/write head assembly that is disposed a variable distance from the storage medium. The process data set is accessed from the storage medium. A first channel bit density estimate is adaptively calculated based at least in part on the process data set and a second channel bit density estimate that was previously calculated. The variable distance is modified based at least in part on the first channel bit density estimate. A third channel bit density is adaptively calculated based at least in part on the process data set and a fourth channel bit density estimate that was previously calculated. The variable distance is modified based at least in part on the third channel bit density estimate. | 06-18-2009 |
| 20090161245 | Frequency Domain Approach for Efficient Computation of Fixed-point Equalization Targets - Various embodiments of the present invention provide systems and methods for equalizing an input signal. For example, various embodiments of the present invention provide a method for performing equalization in a storage device. Such methods include providing an equalizer circuit that is governed by a target value, and a filter circuit that is governed by a filter coefficient. An initial value is provided to the equalizer circuit as the target value, and an overall target based at least in part on the initial value and the filter coefficient is calculated. An updated value is calculated based on the overall target, and the updated value is provided to the equalizer circuit as the target value. | 06-25-2009 |
| 20090235116 | Systems and Methods for Regenerating Data from a Defective Medium - Various embodiments of the present invention provide systems and methods for data regeneration. For example, a system for data regeneration is disclosed that includes a data input derived from the medium. A data detector and a data recovery system receive the data input. The data detector provides a first soft output, and the data recovery system provides a second soft output. The first soft output and the second soft output are provided to a multiplexer. A media defect detector performs a media defect detection process, and provides a defect flag that indicates whether the data input is derived form a defective portion of the medium. The defect flag is provided to the multiplexer where it is used to select whether the first soft output or the second soft output is provides as an extrinsic output. | 09-17-2009 |
| 20090268848 | Systems and Methods for Filter Based Media Defect Detection - Various embodiments of the present invention provide systems and methods for media defect detection. For example, a data receiving system is disclosed that includes a data signal provided from a medium that may include a defective portion. An absolute value circuit receives the data signal and provides an output corresponding to an absolute value of the data signal. The output corresponding to the absolute value of the data signal is input to a filter that filters it and provides a filtered output. In some cases, the filter is a digital filter operable to integrate the absolute value of the data signal. A comparator receives the output from the filter and compares it with a threshold value. The result of the comparison indicates a defect status of the medium. | 10-29-2009 |
| 20100053787 | Systems and Methods for On-The-Fly Write Pre-compensation Estimation - Various embodiments of the present invention provide systems and methods for write pre-compensation. For example, various embodiments of the present invention provide systems for on-the-fly estimation of write pre-compensation values. Such systems include a magnetic storage medium, a read/write head assembly disposed in relation to the magnetic storage medium, and an analog to digital converter that receives an analog signal from the read/write head assembly corresponding to a data set stored on the magnetic storage medium and provides a series of digital samples corresponding to the data set. The storage devices further include a read data processing circuit that receives the same series of digital samples and provides a user data output, and a pre-compensation value calculation circuit that receives the series of digital samples and provides an updated write pre-compensation value. | 03-04-2010 |
| 20100053793 | Systems and Methods for Adaptive Write Pre-Compensation - Various embodiments of the present invention provide systems and methods for write pre-compensation. For example, various embodiments of the present invention provide methods for modifying magnetic information transfer. The methods include retrieving magnetically represented data from a storage medium, and converting the magnetically represented data to a series of data samples. A preceding pattern and a transition status is identified in the series of data samples, and an equalized channel response is computed based on an estimated NLTS value. An error value is computed that corresponds to a difference between the estimated NLTS value and an actual NLTS value, and a pre-compensation value is computed based at least in part on the error value. | 03-04-2010 |
| 20100088357 | Systems and Methods for Memory Efficient Signal and Noise Estimation - Various embodiments of the present invention provide systems and methods for estimating signal and noise powers in a received signal set. For example, one embodiment of the present invention provides a method for determining signal power and noise power. The method uses a storage medium that includes a N | 04-08-2010 |
| 20100157458 | Systems and Methods for Dibit Correction - Various embodiments of the present invention provide systems and methods for providing a corrected dibit signal. As an example, various embodiments of the present invention provide dibit correction circuits. Such dibit correction circuits include a dibit sample buffer, a maximum sample detector circuit, a side sample detector circuit, and a dibit correction circuit. The dibit sample buffer includes a plurality of samples of an uncorrected dibit signal. The maximum sample detector circuit identifies a maximum sample of the plurality of samples of the uncorrected dibit signal, and the side sample detector circuit identifies a first side sample prior to the maximum sample on the uncorrected dibit signal and a second side sample following the maximum sample on the uncorrected dibit signal. The dibit correction circuit applies a correction factor calculated based at least in part on the maximum sample, the first side sample and the second side sample to at least a subset of the plurality of samples of the uncorrected dibit signals to yield a plurality of corrected dibit signals. | 06-24-2010 |
| 20100157464 | Systems and Methods for Adaptive MRA Compensation - Various embodiments of the present invention provide systems and methods for reducing head distortion. For example, various embodiments of the present invention provide storage devices that include a storage medium, a read/write head assembly, and an adaptive distortion modification circuit. The storage medium includes information that may be sensed by the read/write head assembly that is disposed in relation to the storage medium. The adaptive distortion modification circuit receives the information sensed by the read/write head assembly and adaptively estimates and implements a distortion compensation factor in the analog domain. In some instances of the aforementioned embodiments, the read/write head assembly includes a magneto resistive head. In such instances, the distortion compensation factor is designed to compensate for non-linear distortion introduced by the magneto resistive head. | 06-24-2010 |
| 20100177419 | AGC Loop with Weighted Zero Forcing and LMS Error Sources and Methods for Using Such - Various embodiments of the present invention provide systems and methods for gain control. For example, some embodiments of the present invention provide variable gain control circuits. Such circuits include a zero forcing loop generating a zero forcing feedback and a least mean square loop generating a least mean square feedback. An error quantization circuit generates a hybrid feedback based upon a threshold condition using the zero forcing feedback and the least mean square feedback. A variable gain amplifier is at least in part controlled by a derivative of the hybrid feedback. | 07-15-2010 |
| 20100177430 | Systems and Methods for Fly-Height Control Using Servo Address Mark Data - Various embodiments of the present invention provide systems and methods for determining fly-height adjustments. For example, various embodiments of the present invention provide storage devices that include a storage medium, a read/write head assembly disposed in relation to the storage medium ( | 07-15-2010 |
| 20100182718 | Systems and Methods for Adaptive CBD Estimation in a Storage Device - Various embodiments of the present invention provide systems and methods for adaptive channel bit density estimation. For example, various embodiments of the present invention provide methods for adaptively estimating channel bit density. Such methods include providing a storage medium ( | 07-22-2010 |
| 20100265608 | Systems and Methods for Storage Channel Testing - Various embodiments of the present invention provide systems and methods for validating elements of storage devices. A an example, various embodiments of the present invention provide semiconductor devices that include a write path circuit, a read path circuit and a validation circuit. The write path circuit is operable to receive a data input and to convert the data input into write data suitable for storage to a storage medium. The read path circuit is operable to receive read data and to convert the read data into a data output. The validation circuit is operable to: receive the write data, augment the write data with a first noise sequence to yield a first augmented data series; and augment a derivative of the first augmented data series with a second noise sequence to yield the read data. | 10-21-2010 |
| 20100271724 | Systems and Methods for Nyquist Tone Harmonic Measurements - Various embodiments of the present invention provide systems and methods for determining changes in fly-height. For example, various embodiments of the present invention provide storage devices that include a storage medium, an offset frequency, a read/write head assembly, and a harmonic fly-height change detection circuit. The storage medium includes a periodic data pattern that repeats at a data frequency. The read/write head assembly disposed in relation to the storage medium such that it senses the periodic data pattern and provides a sensed periodic data pattern. The harmonic fly-height change detection circuit samples the sensed periodic data pattern at an aggregate frequency to yield a first set of samples and a second set of samples. The aggregate frequency is the data frequency adjusted by the offset frequency. The harmonic fly-height change detection circuit calculates a first magnitude of the first set of samples and a second magnitude of the second set of samples. | 10-28-2010 |
| 20100287420 | Systems and Methods for Adaptive Equalization in Recording Channels - Various embodiments of the present invention provide systems and methods for performing adaptive equalization. For example, various embodiments of the present invention provide methods for adaptive equalization that include providing a data processing system with an equalizer circuit ( | 11-11-2010 |
| 20110043938 | Systems and Methods for Fly-Height Control Using Servo Data - Various embodiments of the present invention provide systems and methods for determining changes in fly-height. For example, various embodiments of the present invention provide storage devices that include a storage medium having servo data thereon. A read/write head assembly is disposed in relation to the storage medium. A servo based fly-height adjustment circuit receives the servo data via the read/write head assembly, and calculates a first harmonics ratio based on the received data and compares the first harmonics ratio with a second harmonics ratio to determine an error in the distance between the read/write head assembly and the storage medium. | 02-24-2011 |
| 20110063747 | Systems and Methods for Timing and Gain Acquisition - Various embodiments of the present invention provide systems and methods for acquiring timing and/or gain information. For example, various embodiments of the present invention provide data processing circuits that include a sample splitting circuit, a first averaging circuit, a second averaging circuit and a parameter calculation circuit. The sample splitting circuit receives a data input that includes a series of samples that repeat periodically over at least a first phase and a second phase. The sample splitting circuit divides the series of samples into at least a first sub-stream corresponding to the first phase and a second sub-stream corresponding to the second phase. The first averaging circuit averages values from the first sub-stream to yield a first average, and the second averaging circuit averages values from the second sub-stream to yield a second average. The parameter calculation circuit calculates a parameter value based at least in part on the first average and the second average. | 03-17-2011 |
| 20110164669 | Systems and Methods for Determining Noise Components in a Signal Set - 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. | 07-07-2011 |
