Patent ID: 7724770

Claim:
An apparatus for switching data in communication system, comprising: a conversion circuit used to receive a source data possessing a real coding dimension and convert the source data into a converted data of a tolerable coding dimension, wherein the converted data possesses judgment bits, and correct bits are designated at the judgment bits of the source data and error bits are designated at the judgment bits of the source data with the real coding dimension not larger than the tolerable coding dimension; a shifter circuit to shift the converted data in a certain shift amount so as to generate a shifted data, then acquisition of the real coding dimension is completed starting from the least significant bit (LSB) of the shifted data to be used as a first data, and acquisition of the real coding dimension is done starting from the most significant bit (MSB) of the shifted data to be used as a second data; and a comparison and selection circuit comparing the judgment bits of the first data and the second data and selecting to output an output data as the data that the source data is shifted in a certain amount.