Patent ID: 6956510

Claim:
A method of encoding an N-ary information sequence into M-ary information, the method comprising the steps of: a) converting each of a first subset of unique x-unit N-ary sequence values into a corresponding one of a first plurality of unique y-unit M-ary sequence values, where x and y are each an integer, N and M are each an integer of at least 2, M y >N x , and each of said corresponding unique y-unit M-ary sequence values is incapable of causing a violation of a coding constraint; and b) converting each of a second subset of unique x-unit N-ary sequence values into (i) a first corresponding member of a second plurality of unique y-unit M-ary sequence values when said first corresponding member does not cause said coding constraint violation, and (ii) a second corresponding member of said second plurality of unique y-unit M-ary sequence values when said first corresponding member causes said coding constraint violation, wherein each of said second plurality of unique y-unit M-ary sequence values is distinct from said first plurality of unique y-unit M-ary sequence values.