ENCODING METHOD, CODE GENERATING METHOD AND MODULATION ENCODER

    公开(公告)号:JPH11355144A

    公开(公告)日:1999-12-24

    申请号:JP6894299

    申请日:1999-03-15

    Applicant: QUANTUM CORP

    Abstract: PROBLEM TO BE SOLVED: To encode the sequence of 32-bit digital data words into that of 32-bit code words in accordance with previously fixed min. 0-run length and max. 0-run length for magnetic medium recording. SOLUTION: The method includes the division of the respective data words into eight data nibbles and judgement indicating whether any one of the data nibbles includes only zero or not. At the time of no code violation, the eight data nibbles are mapped into the seven code nibbles and the four bits of a five-bit code sub-word and a fifth control bit is set to one. When more than one code violation exist, the places are padded in at least the five-bit code sub-word and in other required code nibbles and, then, the data nibbles toward a normal code sub-word and the nibble place are mapped again to the code place which originally includes the data nibble judged to be the code violation.

    High rate run length limited modulation codes

    公开(公告)号:GB2337909A

    公开(公告)日:1999-12-01

    申请号:GB9905837

    申请日:1999-03-15

    Applicant: QUANTUM CORP

    Abstract: A method and apparatus for encoding a sequence of 32 bit digital data words into a sequence of 33 bit code words in consonance with predetermined minimum zero tun length (d) and predetermined maximum zero run length (k) for recording upon a magnetic medium within a magnetic recording channel is disclosed. The method comprises steps of dividing each data word into eight data nibbles, determining whether any data nibble contains all zeros. If no code violation, mapping the eight data nibbles to seven code nibbles and to four bits of a five bit code sub-word and setting a fifth control bit to one. If one or more code violations are present, embedding code violation locations within at least the five bit code sub-word and other code nibbles if necessary and remapping data nibbles ordinarily directed to the code sub-word and nibble locations to code locations otherwise containing the data nibbles determined to be code violations.

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