Patent ID: 7529170

Claim:
A method of modulating a source data to a code data under condition of a given code rate and run length limited (rll), said method comprising: (a) inputting the source data; and (b) modulating the source data into code data based on a bit sequence of the source data by using a map table and an additional table, wherein the map table comprises source data of 2 bits to be converted into code data of 3 bits, source data of 4 bits to be converted into code data of 6 bits, source data of 6 bits to be converted into code data of 9 bits, and source data of 8 bits to be converted into code data of 12 bits, and the additional table comprises source data to be converted into additional code data, the source data in the additional table including at least a bit sequence of source data which is not included in the map table, wherein the modulating step (b) includes selecting the additional code data as code data based on at least a sequence of a next modulated data.