Method and apparatus for encoding with unequal protection in magnetic recording channels having concatenated error correction codes

摘要

An encoder and method of encoding data words are provided, which map a block of at least one of the data words into an error correction code (ECC) code word. The ECC code word is defined by a plurality of multiple-bit ECC symbols which are separated by boundaries. Bit patterns are constrained from occurring in the ECC code word based on a relative location of the bit patterns to the boundaries.