Decoding device and decoding method

摘要

Improper correction is avoided in decoding of an extended Reed-Solomon code. The decoding device includes: a syndrome computation section for computing input data syndromes from input data and corrected data syndromes from first corrected data obtained from the input data; an evaluator/locator polynomial deriving section for outputting coefficients at each order of an error evaluator polynomial and an error locator polynomial obtained based on the input data syndromes, as well as error magnitudes; a Chien search section for outputting roots of the error locator polynomial; and an error correction section for outputting data obtained by performing error correction for the input data when the input data has an error while otherwise outputting the input data, as the first corrected data, and also outputting the input data obtained by restoration when the first corrected data has an error while otherwise outputting the first corrected data, as second corrected data.