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 detected by generating two statistical measures (e.g., β1(k) and β2(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.
摘要翻译:在硬盘驱动器中,通过基于信号值(例如,x [n]或x(n))生成两个统计度量(例如,&bgr; 1(k)和&bgr; 2(k))来检测硬盘上的缺陷区域 y [n])和软判决值(例如,L [n])。 比较措施来检测硬盘驱动器缺陷区域的位置。 使用软判决值可减少统计度量与由不基于软判决值的统计测量形成的比率的比率的波动,导致检测缺陷区域的更可靠的测试。
摘要:
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
摘要:
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.
摘要:
The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for coasting one or more calibration loops based upon identification of a probability of data inaccuracies. One embodiment is a data processing system that includes: a defect detector circuit operable to identify a defect region during a first pass processing of a received data set; a defect location buffer operable to maintain an indication of the defect region in the received data set; and a calibration circuit operable to adaptively update a calibration output during a second pass processing of the received data set, where updating the calibration output is disabled for one or more samples of the received data set corresponding to the indication of the defect region.
摘要:
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.
摘要:
The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for coasting one or more calibration loops based upon identification of a probability of data inaccuracies.
摘要:
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. A second detection circuit applies a phase dependent data detection algorithm to the phase shifted output such that a second output of the second data detection circuit varies from the first output at least in part due to a different phase of the data set presented to the second data detection circuit.
摘要:
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.
摘要:
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.