Patent ID: 7293220

Claim:
An apparatus for accessing data from a storage medium comprising at least one data block, wherein the data block comprises a plurality of data sectors and an error correction code (ECC), and each of the data sectors comprises an error detection code (EDC), the apparatus comprising: an accessing unit for fetching the data block from the storage medium; an ECC decoder, coupled to the accessing unit, for correcting an error of the data block according to the ECC of the data block; an EDC processor, coupled to the ECC decoder, for calculating the EDC for each of the data sectors of the data block; and a flag register for storing a flag associated with each of the data sectors of the data block, wherein the flag indicates correctness of the EDC of the associated data sector, wherein when the flag indicates that the EDC of the associated data sector is incorrect, the associated data sector is re-fetched, wherein when the flag indicates that the EDC of the associated data sector is correct, the associated data sector is bypassed if the data block is re-fetched, wherein when the flag indicates that the EDC of the associated data sector is correct and the ECC indicates that the associated data sector contains an error, the associated data sector is prevented from error correction of the ECC decoder.