Patent ID: 8010879

Claim:
A data storage device comprising: a disk storage medium having a plurality of sectors containing data; a head for performing a writing process or a reading process into or from said disk storage medium upon a write command or a read command transferred from a host; and means for correcting an error that occurs in said data during said reading process; wherein said means performs the error correction, using a first error correcting code appended to each sector of said plurality of sectors and a second error correcting code appended to a predetermined sector of every block of sectors composed of a predetermined number of sectors, said second error correcting code having a greater correction capability than said first error correcting code, and further comprises: a first buffer for storing data transferred from said disk storage medium; an error correcting circuit for performing an error correcting process on the basis of said first error correcting code while reading said data from said first buffer; and a second buffer for storing the data subjected to error correction on the basis of said first error correcting code and the data which is uncorrectable on the basis of said first error correcting code.