Abstract: In a hard-disc drive, a defect region on the hard disc is detected by generating two statistical measures (e.g., ?1(k) and ?2(k)) based on signal values (e.g., x[n] or y[n]) and soft-decision values (e.g., L[n]) corresponding to the signal values. The measures are compared to detect the location of the defect region of the hard drive. Using the soft-decision values reduces fluctuations in a ratio of the statistical measures compared to a ratio formed from statistical measures that are not based on soft-decision values, resulting in a more-reliable test for detecting defect regions.

Abstract: 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.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. For example, a data processing system is disclosed that includes a channel detector circuit. The channel detector circuit includes a branch metric calculator circuit that is operable to receive a number of violated checks from a preceding stage, and to scale an intrinsic branch metric using a scalar selected based at least in part on the number of violated checks to yield a scaled intrinsic branch metric.

Abstract: Various systems and methods for tri-column code based error reduction are disclosed herein. For example, a digital information system is disclosed that includes channel detector. Such a channel detector receives an encoded data set and provides an output representing the encoded data set. The exemplary system further includes a decoder that receives the first output and is operable to perform three slope parity checks on the received first output. In turn, the decoder provides another output representing the encoded data set.

Abstract: 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.

Abstract: Various embodiments of the present invention provide systems and methods for data processing retries. As an example, a data processing retry circuit is discussed that includes a stepped erasure window register, and an erasure flag set circuit. The stepped erasure window register includes: an erasure flag location, an erasure flag length, and a step size. The erasure flag set circuit is operable to assert a first erasure flag beginning at the erasure flag location and having the erasure flag length at a first time. In addition, the erasure flag set circuit is operable to assert a second erasure flag beginning at the erasure flag location plus the step size, and having the erasure flag length at a second time.

Abstract: Various embodiments of the present invention provide systems and methods for flaw scan in a data processing system. As one example, a data processing system is disclosed that includes a data detector circuit, a bit sign inverting circuit, and an LDPC decoder circuit. The data detector circuit receives a verification data set that is an invalid LDPC codeword, and applies a data detection algorithm to the verification data set to yield a detected output. The bit sign inverting circuit modifies the sign of one or more elements of a first derivative of the detected output to yield a second derivative of the detected output. The second derivative of the detected output is an expected valid LDPC codeword. The LDPC decoder circuit applies a decoding algorithm to the second derivative of the detected output to yield a decoded output.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. For example, a data processing circuit is disclosed that includes a first data detection circuit that applies a phase dependent data detection algorithm to a data set such that a first output of the first data detection circuit varies depending upon a phase of the data set presented to the first data detection circuit. A first phase of the data set is presented to the first data detection circuit. The circuits further include a decoder circuit that applies a decoding algorithm to the first output to yield a decoded output, and a phase shift circuit that phase shifts the decoded output such that a second phase of the data set is provided as a phase shifted output.

Abstract: 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 an LDPC codeword, and grouping active bits from the LDPC codeword into a series of data bits including one or more user data bits including and at least one LDPC parity bit. The series of data bits satisfies an LDPC parity equation.

Abstract: 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.

Abstract: The present invention provides systems and methods for detecting a media defect. A circuit providing a hard output and a soft output is used with the hard output and the soft output being combined and the product compared with a threshold. Based at least in part on the comparison, a media defect may be identified.

Abstract: Various systems and methods for tri-column code based error reduction are disclosed herein. For example, a digital information system is disclosed that includes channel detector. Such a channel detector receives an encoded data set and provides an output representing the encoded data set. The exemplary system further includes a decoder that receives the first output and is operable to perform three slope parity checks on the received first output. In turn, the decoder provides another output representing the encoded data set.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. For example, a data processing system is disclosed that includes a processing loop circuit having a data detector and a soft decision decoder. The data detector provides a detected output, and the soft decision decoder applies a soft decoding algorithm to a derivative of the detected output to yield a soft decision output and a first hard decision output. The systems further include a queuing buffer and a hard decision decoder. The queuing buffer is operable to store the soft decision output, and the hard decision decoder accesses the soft decision output and applies a hard decoding algorithm to yield a second hard decision output.

Abstract: Various embodiments of the present invention provide systems and methods for deriving data from a defective media region. As an example, a method for deriving data from a defective media region is disclosed that includes providing a storage medium and performing a media defect detection that indicates a defective region on the storage medium. A first data decode is performed on data corresponding to the defective region. The first data decode yields a first output. It is determined that the first output failed to converge and based at least in part on the failure of the first output to converge, a second data decode is performed on the data corresponding to the defective region. The second data decode includes zeroing out any soft data corresponding to the defective region and providing a second output.

Abstract: 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.

Abstract: Various systems and methods for code dependency reduction are disclosed herein. For example, one method includes receiving an un-encoded data set that is represented as an array of columns and rows. In addition, two groups of data bits traversing the un-encoded data set at respective angles are formed. Based at least in part on the aforementioned groups of data sets, an angle at which a third group of data bits will traverse the un-encoded data set is identified, and a third group of data bits traversing the un-encoded data set at the third angle is formed.

Abstract: Various systems and methods for code based error reduction. For example, in one digital information system including a channel detector and a decoder, the channel detector receives an encoded data set and is operable to perform a column parity check. The channel detector provides an output representing the encoded data set. The decoder receives the output from the channel detector and is operable to perform two checks. The two checks may be one of: two pseudo-random parity checks, a pseudo-random parity check and a slope parity check, and two slope parity checks. In addition, the decoder provides another output representing the encoded data set.

Abstract: Various embodiments of the present invention provide systems and methods for detecting storage medium defects. As one example, a media defect detection system is disclosed that includes a data detector circuit that applies a detection algorithm to the data input and provides a hard output and a soft output. A first circuit combines a first derivative of the hard output with a derivative of the data input to yield a first combined signal. A second circuit combines a second derivative of the hard output with a derivative of the first combined signal to yield a second combined signal. A third circuit combines a derivative of the soft output with the second combined signal and a threshold value to yield a defect signal.

Abstract: Various embodiments of the present invention provide systems and methods for data regeneration. For example, a system for regenerating data is disclosed. The system includes a media defect detector that is operable to identify a potential media defect associated with a medium from which an input signal is derived, an attenuation amplitude detector that generates an attenuation factor, and a data detector. The data detector includes a first data path and a second data path. The first data path includes a bank of two or more selectable noise prediction filters and the second data path includes a fixed noise prediction filter and the attenuation factor. The data detector processes a derivative of the input signal using the second data path when the potential media defect is indicated, and processes the derivative of the input signal using the first data path when a media defect is not indicated.

Abstract: Various systems and methods for tri-column code based error reduction are disclosed herein. For example, a digital information system is disclosed that includes channel detector. Such a channel detector receives an encoded data set and provides an output representing the encoded data set. The exemplary system further includes a decoder that receives the first output and is operable to perform three slope parity checks on the received first output. In turn, the decoder provides another output representing the encoded data set.