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., ∝1) 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., ∝2) 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.
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.
摘要:
Various embodiments of the present invention provide systems and methods for generating a code format. One method discussed includes: receiving a first matrix having a row width and a column height that is greater than one; incorporating a circulant into a first column of the first matrix; testing the first column for trapping sets, wherein at least one trapping set is identified; selecting a value to mitigate the identified trapping set; and augmenting the first matrix with a second matrix to yield a composite matrix. The second matrix has the selected value in the first column, and wherein the identified trapping set is mitigated.
摘要:
Various embodiments of the present invention provide systems and methods for generating a code format. One method discussed includes: receiving a first matrix having a row width and a column height that is greater than one; incorporating a circulant into a first column of the first matrix; testing the first column for trapping sets, wherein at least one trapping set is identified; selecting a value to mitigate the identified trapping set; and augmenting the first matrix with a second matrix to yield a composite matrix. The second matrix has the selected value in the first column, and wherein the identified trapping set is mitigated.
摘要:
In a hard-disc drive read channel, frequency-based measures are generated at two different data frequencies (e.g., 2T and DC) by applying a transform, such as a discrete Fourier transform (DFT), to signal values, such as ADC or equalizer output values, corresponding to, e.g., a 2T data pattern stored on the hard disc. The frequency-based measures are used to detect defect regions on the hard disc and/or to classify defect regions as being due to either thermal asperity (TA) or drop-out media defect (MD).
摘要:
Various embodiments of the present invention provide systems and methods for generating a parity check matrix used in data processing. As an example, a method for generating a parity check matrix including selecting a non-affiliated variable node; identifying a check node of the lowest degree; connecting a first edge of the non-affiliated variable node to the identified check node; and connecting one or more additional edges of the non-affiliated variable node to check nodes in accordance with a quasi-cyclic constraint associated with a circulant is disclosed.
摘要:
Various embodiments of the present invention are related to methods and apparatuses for interleaving data, and more particularly to methods and apparatuses for interleaving variably sized blocks of data. For example, in one embodiment an apparatus includes a data partitioner operable to partition the block of data into a real data portion and a missing bits portion. The real data portion is adapted to contain data bits from the variably sized block of data and the missing bits portion is adapted to be filled with a variable number of the data bits. The apparatus also includes at least one local interleaver operable to apply a permutation across each of a plurality of sub-portions of the real data portion and the missing bits portion, and a global interleaver operable to apply a global permutation across the real data portion.
摘要:
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 data detector circuit, a data decoder circuit, and a power monitor circuit. The data detector circuit is operable to apply a data detection algorithm to a data input and a decoded output to yield a detected output. The data decoder circuit is operable to apply a data decoding algorithm to the detected output to yield the decoded output. The power monitor circuit is operable to receive a first power status signal from the data detector circuit and a second power status from the data decoder circuit, and to calculate a power usage of a combination of at least the data detector circuit and the data decoder circuit. In such a system, a number of global iterations through a combination of the data decoder circuit and the data detector circuit is variable and both of the first power status signal and the second power status signal varies at least in part as a function of the number of global iterations.
摘要:
In a hard-disc drive read channel, frequency-based measures are generated at two different data frequencies (e.g., 2T and DC) by applying a transform, such as a discrete Fourier transform (DFT), to signal values, such as ADC or equalizer output values, corresponding to, e.g., a 2T data pattern stored on the hard disc. The frequency-based measures are used to detect defect regions on the hard disc and/or to classify defect regions as being due to either thermal asperity (TA) or drop-out media defect (MD).