Patent ID: 6643814
Filing Date: 2003-11-04
Classification: G11B,H03M,H04L

Abstract:
A method 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, the method comprising the steps of:encoding each M-bit data word in accordance with an MTR coding scheme to produce a G-bit word, where N>G>M, such that the maximum number of consecutive bits of a first value in a succession of said G-bit words is limited to a first predetermined value j1; and encoding said G-bit word to produce a said N-bit word in accordance with a second coding scheme wherein at least one parity bit, dependent on the bit-values of said G-bit word, is generated, such that the N-bit word satisfies a predetermined parity condition, and wherein bits of said first value in the G-bit word are mapped to respective bits of the N-bit word which are each of different value to the immediately preceding bit in the N-bit word; wherein the second coding scheme is such that, in a succession of said N-bit words, the maximum number of consecutive bits which are each of different value to the immediately preceding bit is limited to a second predetermined value j2.