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 media defect detection. For example, a media defect detection systems is disclosed that includes a data input derived from a medium, a fast envelope calculation circuit that receives the data input and provides a fast decay envelope value based on the data input, a slow envelope calculation circuit that receives the data input and provides a slow decay envelope value based on the data input, and a media defect detection circuit. The media defect detection circuit receives the slow decay envelope value and the fast decay envelope value, calculates a ratio value of the fast decay envelope value to the slow decay envelope value, and asserts a defect output based at least in part on the comparison of the ratio value to a defect threshold value.

Abstract: Various embodiments of the present invention provide systems and methods for variable iteration data processing.

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: Various embodiments of the present invention provide systems and methods for media defect detection. For example, a data transfer system is disclosed that includes a data detector, a defect detector and a gating circuit. The data detector provides a soft output, and the defect detector is operable to receive the soft output and the data signal, and to assert a defect indication based at least in part on the soft output and the data signal. The gating circuit is operable to modify the soft output of the detector whenever the defect indication is asserted.

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. The data detector is operable to perform a data detection on a derivative of the soft decision output if the soft decision decoder and the hard decision decoder fail to converge.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. For example, data processing systems are disclosed that include a data decoding system.

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 combination data decoder circuit. The combination data decoder circuit includes a first decoder circuit and a second decoder circuit. The first decoder circuit is operable to apply a first data decode algorithm to a decoder input to yield a decoded output. The second decoder circuit is operable to apply a second data decode algorithm to a subset of the decoded output to modify at least one element of the decoded output to yield a modified decoded output.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. As an example, a data processing system is discussed that includes: a data detector circuit, a symbol selective scaling circuit, and a data decoder circuit. The data detector circuit is operable to apply a data detection algorithm to a data input guided by a first data set derived from a decoded output to yield a detected output. The symbol selective scaling circuit is operable to selectively scale one or more symbols of a second data set derived from the detected output to yield a scaled data set. The data decoder circuit operable to apply a data decode algorithm to a third data set derived from the scaled data set to yield the decoded output.

Abstract: Various embodiments of the present invention provide systems, devices and methods for data processing. As an example, a data processing device is discussed that include a data encoding system and a data decoding system. The data encoding system is operable to receive a data input, and to: apply a maximum transition run length encoding to the data input to yield a run length limited output; apply a low density parity check encoding algorithm to the run length limited output to yield a number of original parity bits; apply a precode algorithm to the original parity bits to yield precoded parity bits; and combine the precoded parity bits and a derivative of the run length limited output to yield an output data set.

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 embodiments of the present invention provide systems and methods for data processing. As an example, a data processing circuit is disclosed that includes a data detector circuit and a bias calculation circuit. The data detector circuit is operable to apply a data detection algorithm to a first data set to yield a first series of soft decision data, and to apply the data detection algorithm to a second data set to yield a second series of soft decision data. The bias calculation circuit operable to calculate a series of bias values based at least in part on the first series of soft decision data and the second series of soft decision data. The series of bias values correspond to a conversion between the first series of soft decision data and the second series of soft decision data.

Abstract: 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 data detector circuit, a biasing circuit, and a data decoder circuit. The data detector circuit is operable to apply a data detection algorithm to a series of symbols to yield a detected output, and the detected output includes a series of soft decision data corresponding to non-binary symbols. The biasing circuit is operable apply a bias to each of the series of soft decision data to yield a series of biased soft decision data. The data decoder circuit is operable to apply a data decoding algorithm to the series of biased soft decision data corresponding to the non-binary symbols.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. As an example, a data processing circuit is discussed that includes: a noise predictive filter circuit, a mean calculation circuit, a summation circuit, and a filter tap adaptation circuit. The noise predictive filter circuit is operable to perform a noise predictive filtering process on a data input based upon a selector input to yield a noise predictive output. The selector input is derived from a data detector output. The mean calculation circuit is operable to average two or more instances of the noise predictive output to yield a mean output. The summation circuit is operable to subtract the mean output from the noise predictive output to yield a sum output. The filter tap adaptation circuit is operable to adaptively calculate a filter tap based at least in part on a value derived from the data input and a value derived from the sum output.

Abstract: The present invention is a device for detecting short burst errors. The device includes a first signal input, wherein the first signal input is configured to receive a first signal. The device includes a second signal input, wherein the second signal input is configured to receive a second signal. The device includes a logic gate, wherein the logic gate is operable for receiving the first signal via the first signal input, receiving the second signal via the second signal input, and generating a logic output gate signal based on the received first signal and the second signal. Furthermore, the device includes a filter, wherein the filter is configured for receiving the logic output gate signal from the logic gate and generates a filter output signal based upon the received logic output gate signal, wherein the filter output signal is operable for flagging errors.

Abstract: Various approaches related to systems and methods for reusing decoding parity.

Abstract: Various embodiments of the present invention provide systems and methods for variable iteration data processing.

Abstract: Certain embodiments of the present invention are improved turbo-equalization methods for decoding encoded codewords. In one embodiment, in global decoding iteration i, the magnitude values of all decoder-input LLR values (Lch) are adjusted based on the number b of unsatisfied check nodes in the decoded codeword produced by global iteration i?1. The improved turbo-equalization methods can be used as the sole turbo-equalization method for a given global decoding session, or interleaved with other turbo-equalization methods.

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: The present invention is a programmable QC LDPC encoder for encoding user data. The encoder may be configurable for implementation with a read channel. The encoder may include a plurality of barrel shifter circuits. The barrel shifter circuits are configured for generating a plurality of parity bits based on interleaved user bits received by the encoder. The barrel shifter circuits are further configured for outputting the parity bits. The encoder may further include an encoder interleaver memory. The encoder interleaver memory may be communicatively coupled with the barrel shifter circuits and may receive the parity bits output from the barrel shifter circuits. The encoder interleaver may be configured for interleaving the parity bits. Further, the encoder may be configured for outputting the interleaved parity bits to a multiplexer. The barrel shifter circuits may generate the plurality of parity bits via an encoding algorithm: p=u*GT.