摘要:
Various embodiments of the present invention provide systems and methods for data processing. For example, some embodiments of the present invention provide noise reduced data processing circuits. Such circuits include a selector circuit, a sample set averaging circuit, and a data detection circuit. The selector circuit provides either a new sample set or an averaged sample set as a sample output based on a select control signal. The sample set averaging circuit receives the new sample set and provides the averaged sample set. The averaged sample set is based upon two or more instances of the new sample set. The data detection circuit receives the sample output, and performs a data detection algorithm on the sample output and provides the select control signal and a data output.
摘要:
Methods and apparatus are provided for improved physical re-read operations in a hard disk drive. The disclosed methods and apparatus selectively retain data in a hard disk drive. A signal is read in an iterative read channel by assigning a reliability metric to each of a plurality of segments in a read signal; repeating the assigning step for a plurality of read operations; and selectively retaining the segments based on the assigned reliability metric. The read signal can be obtained by positioning a transducer over a storage media. The reliability metric may be based on soft bit decisions; log likelihood ratios or a noise estimation of a given segment.
摘要:
Methods and apparatus are provided for improved physical re-read operations in a hard disk drive. The disclosed methods and apparatus selectively retain data in a hard disk drive. A signal is read in an iterative read channel by assigning a reliability metric to each of a plurality of segments in a read signal; repeating the assigning step for a plurality of read operations; and selectively retaining the segments based on the assigned reliability metric. The read signal can be obtained by positioning a transducer over a storage media. The reliability metric may be based on soft bit decisions; log likelihood ratios or a noise estimation of a given segment.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Various embodiments of the present invention provide systems and methods for data processing. For example, a method for data processing is disclosed that includes receiving a codeword that has at least a first circulant with a plurality of data bits and a first circulant parity bit, a second circulant with a plurality of data bits and a second circulant parity bit, and one or more codeword parity bits. The methods further include decoding the codeword using the one or more codeword parity bits to access the first circulant and the second circulant, performing a first circulant parity check on the first circulant, and performing a second circulant parity check on the second circulant.
摘要:
Two levels of error correction decoding are performed using first and second level decoders. A composite code formed by combining an inner component code and an outer component code can be used to decode the data and correct any errors. Performing two level decoding using a composite code allows the size of the inner parity block to be reduced to a single Reed-Solomon symbol while keeping a good code rate. The first level decoder generates soft information. The soft information can indicate a most likely error event for each possible syndrome value of the inner component code. The soft information can also include error metric values for each of the most likely error events. The second level decoder generates corrected syndrome values based on the soft information using the outer component code. The most likely trellis path that corresponds to the corrected syndrome values is then selected.
摘要:
In exemplary embodiments, a skewed interleaving function for iterative code systems is described. The skewed interleaving function provides a skewed row and column memory partition and a layered structure for re-arranging data samples read from, for example, a first channel detector. An iterative decoder, such as an iterative decoder based on a low-density parity-check code (LDPC), might employ an element to de-skew the data from the interleaved memory partition before performing iterative decoding of the data, and then re-skew the information before passing decoded samples to the de-interleaver. The de-interleaver re-arranges the iterative decoded data samples in accordance with an inverse of the interleaver function before passing the decoded data samples to, for example, a second channel detector.
摘要:
In a hard-disc drive, a defect region on the hard disc is classified as corresponding to either thermal asperity (TA) or media defect (MD) by generating two statistical measures. A first measure (e.g., α1) is based on (i) the magnitudes of one or both of signal values (e.g., equalizer input or output signal values) and the corresponding expected values of those signal values and (ii) the signs of one or both of the signal values and the expected signal values. A second measure (e.g., α2) is based on the magnitudes of one or both of the signal values and the expected signal values, but not the signs of either the signal values or the expected signal values. The two measures are then compared to determine whether the defect region corresponds to TA or MD.