公开(公告)号：GB2355165A

公开(公告)日：2001-04-11

申请号：GB0016683

申请日：2000-07-07

Applicant: IBM

Inventor： CIDECIYAN ROY D ,  COKER JONATHAN D ,  ELEFTHERIOU EVANGELOS ,  GALBRAITH RICHARD L ,  TRUAX TODD

IPC: G11B20/14 ,  G11B20/18 ,  H03M5/14 ,  G06F11/10 ,  H03M7/14 ,  H03M7/42 ,  H03M13/01 ,  H03M13/05 ,  H03M13/31 ,  H04L1/00 ,  H04L25/49

Abstract: Methods and apparatus are provided for encoding a succession of m-bit data words to produce a succession of n-bit code words, where n > m, for supply to a magnetic recording channel. Each m-bit data word is partitioned into a plurality of blocks of bits (5a, 6a, 7a), and at least one of said blocks is encoded (5, 6, 7) in accordance with a block coding scheme such that the resulting bit sequence derived from the m bits of the data word comprises an n-bit sequence (5b, 6b, 7b). An n-bit code word is then produced by at least one stage of violation correction (8,9). The or each stage of violation correction comprises detecting the occurrence of any of a plurality of prohibited bit patterns at one or more predetermined locations in the n-bit sequence, and replacing any prohibited bit pattern so detected by a respective substitute bit pattern (8b, 9b). The block coding scheme and the prohibited and substitute bit patterns are predetermined such that, in a succession of said n-bit code words, the maximum number of consecutive bits of one value is limited to a first predetermined number j, where j / 2, and the maximum number of consecutive bits of the other value is limited to a second predetermined number k.

公开(公告)号：GB2355165B

公开(公告)日：2003-10-22

申请号：GB0016683

申请日：2000-07-07

Applicant: IBM

Inventor： CIDECIYAN ROY D ,  COKER JONATHAN D ,  ELEFTHERIOU EVANGELOS ,  GALBRAITH RICHARD L ,  TRUAX TODD

IPC: G11B20/14 ,  G11B20/18 ,  H03M5/14 ,  G06F11/10 ,  H03M7/14 ,  H03M7/42 ,  H03M13/01 ,  H03M13/05 ,  H03M13/31 ,  H04L1/00 ,  H04L25/49

Abstract: A method and apparatus for encoding a plurality of successive m-bit binary data words to produce a plurality of successive of n-bit binary code words, where n and m are positive integers and n is greater than m, for supply to a magnetic recording channel. Each m-bit binary data word is partitioned into a plurality of blocks of bits, and at least one said blocks of bits in each m-bit binary data word is encoded in accordance with a finite-state coding scheme to produce a plurality of successive n-bit binary code words. At least one stage of violation correction which transforms the plurality of successive n-bit binary code words. Violation correction includes detecting the occurrence of any of a plurality of prohibited bit patterns at one or more predetermined locations within each n-bit binary coded word, and replacing any prohibited bit pattern so detected by a corresponding substitute bit pattern. The finite-state coding scheme, the prohibited bit patterns, and corresponding substitute bit patterns are predetermined such that in a serial bit-steam comprising the successive n-bit binary code words, the maximum number of consecutive bits of a first value is limited to a first predetermined number j, where b greater or equal to 2, and the maximum number of consecutive bits of the a second value is limited to a second predetermined number k.