摘要:
A longitudinal position (LPOS) word L(n) is encoded with error correction capability. The LPOS word includes a plurality of LPOS symbols L0(n) through Lk(n) calculated as L ( n ) = ∑ i = 0 5 L i ( n ) 14 i and representing a longitudinal position of a magnetic tape relative to a tape head in a tape storage system. A word type is determined in response to at least one of the plurality of LPOS symbols and, in response to the determined word type, at least one formatted symbol F(n) is generated from the plurality of LPOS symbols L(n). At least one parity symbol P(n) is generated from the formatted symbol F(n). The formatted and parity symbols are communicated to a servo channel of the tape storage system to be recorded onto a servo track of the magnetic tape. Adding redundancy to LPOS words provides the capability of correcting multiple bit errors without increasing the LPOS word length.
摘要:
A method and apparatus for providing error correction capability to longitudinal position data are disclosed. Initially, data are encoded via a set of even LPOS words and a set of odd LPOS words. The encoded data are then decoded by generating a set of syndrome bits for each of the LPOS words. A determination is then made as to whether or not there is an error within one of the LPOS words based on its corresponding syndrome bits.
摘要:
A method and apparatus for providing error correction capability to longitudinal position data are disclosed. Initially, data are encoded via a set of even LPOS words and a set of odd LPOS words. The encoded data are then decoded by generating a set of syndrome bits for each of the LPOS words. A determination is then made as to whether or not there is an error within one of the LPOS words based on its corresponding syndrome bits.
摘要:
A method and apparatus for providing error correction capability to longitudinal position data are disclosed. Initially, data are encoded via a set of even LPOS words and a set of odd LPOS words. The encoded data are then decoded by generating a set of syndrome bits for each of the LPOS words. A determination is then made as to whether or not there is an error within one of the LPOS words based on its corresponding syndrome bits.
摘要:
A method and apparatus for providing error correction capability to longitudinal position data are disclosed. Initially, data are encoded via a set of even LPOS words and a set of odd LPOS words. The encoded data are then decoded by generating a set of syndrome bits for each of the LPOS words. A determination is then made as to whether or not there is an error within one of the LPOS words based on its corresponding syndrome bits.
摘要:
Methods and apparatus are provided for encoding input data for recording in s-level storage of a solid state storage device, where s f 2. Input data words are encoded in groups of M input data words in accordance with first and second BCH codes to produce, for each group, a set of M first codewords of the first BCH code. The set of M first codewords is produced such that at least one predetermined linear combination of the M first codewords produces a second codeword of the second BCH code, this second BCH code being a sub-code of the first BCH code. The sets of M first codewords are then recorded in the s-level storage. If each of the first and second codewords comprises N q-ary symbols where q=pk, k is a positive integer and p is a prime number, the q-ary code alphabet can be matched to the s-ary storage by ensuring that q and s are uth and vth powers respectively of a common base r, where u and v are positive integers and k f u, whereby p(k/u)v=s.
摘要:
A method and apparatus for providing a read channel having combined parity and non-parity post processing is disclosed. A post-processor combines parity and non-parity post processing to make both parity and non-parity corrections so that error events that cannot be detected by parity may be corrected. Non-parity detectable error events are only kept for consideration if their likelihood is above a set threshold.
摘要:
Techniques are provided for applying modulation constraints to data by using periodically changing symbol mappings to replace certain prohibited error prone data patterns. Initially, user data in a first base is mapped to integers of a second base using a base conversion technique. The integers in the second base correspond to symbols. Subsequently, periodically changing symbol mappings are performed during which prohibited symbols generated during base conversion are mapped to permitted symbols. The periodically changing symbol mappings occur in multiple phases, and the prohibited symbols are different in each phase. The resulting data is processed by a precoder in some embodiments.
摘要:
Methods and apparatus are provided for controlling data management operations including storage of data in solid state storage of a solid state storage system. Input data is stored in successive groups of data write locations in the solid state storage. Each group comprises a set of write locations in each of a plurality of logical subdivisions of the solid state storage. The input data to be stored in each group is encoded in accordance with first and second linear error correction codes. The encoding is performed by constructing from the input data to be stored in each group a logical array of rows and columns of data symbols. The rows and columns are respectively encoded in accordance with the first and second linear error correction codes to produce an encoded array in which all rows correspond to respective first codewords and columns correspond to respective second codewords.
摘要:
A data storage system includes an encoder subsystem comprising an error correction code encoder, a modulation encoder, and a precoder, and a decoder subsystem similarly comprising a detector, an inverse precoder, a channel decoder, and an error correction code decoder. The error correction encoder applies an error correction code to the incoming user bit stream, and the modulation encoder applies so-called modulation or constrained coding to the error correction coded bit stream. The precoder applies so-called preceding to the modulation encoded bit stream. However, this preceding is applied to selected portions of the bit stream only. There can also be a permutation step where the bit sequence is permuted after the modulation encoder before preceding is applied by the precoder. The decoder subsystem operates in the inverse manner.