Patent ID: 7113114

Claim:
A method for converting data words to code words, comprising the steps of: (a) inserting p guided bits before inputting each set of data words, performing a default operation, and generating 2 p data sequences with different guided bits; (b) selecting q data sequences from said 2 p data sequences for coding; (c) performing a run length limited (RLL) coding with a coding rate m/n, and generating q code word sequences satisfying (d, k) constrain; and (d) selecting an optimal (d, k) constrained code word sequences from said q (d, k) constrained code word sequences; wherein p and q are positive integers with q<2 p , m is the length of the data bits, n is the length of the code word bits, d is the minimum numbers of the consecutive zeros in the code word, and k is the maximum numbers of the consecutive zeros in the code word.