System and method for providing error correction coding with selectively variable redundancy

A computer program product including a computer readable medium having computer readable program code means embodied thereon, for correcting errors in data stored in data memory, the computer program product comprising:

• first computer readable program code means for generating check symbols from received information symbols;
• second computer readable program code means for forming interleaved code words from the information symbols and a first group of the check symbols;
• third computer readable program code means for generating at least one group of extended check symbols from a second group of the check symbols that do not form portions of the interleaved code words;
• fourth computer readable program code means for storing the interleaved code words and the extended check symbols in memory without the second group of check symbols;
• fifth computer readable program code means for retrieving the interleaved code words and extended check symbols from memory;
• sixth computer readable program code means for decoding the retrieved interleaved code words;
• seventh computer readable program code means for identifying uncorrectable interleaved code words based upon the sixth computer readable program code means;
• eighth computer readable program code means for recovering the second group of check symbols from the extended check symbols, the retrieved uncorrectable interleaved code words and the corresponding recovered second group of check symbols forming extended interleaved code words;
• and
• ninth computer readable program code means for decoding the extended interleaved code words following the recovering of formation of the extended interleaved code word.

A computer program product including a computer readable medium having computer readable program code means embodied thereon, for correcting errors in data stored in data memory, the computer program product comprising:

• first computer readable program code means for retrieving interleaved code words and extended check symbols from memory;
• second computer readable program code means for decoding the interleaved code words;
• third computer readable program code means for identifying uncorrectable interleaved code words based upon the decoding by the second computer readable program code means;
• fourth computer readable program code means for generating first check symbols relating to the uncorrectable interleaved code words from the extended check symbols in response to the decoding, the first check symbols being added to the uncorrectable interleaved code words to form extended interleaved code words;
• and
• fifth computer readable program code means for decoding the extended interleaved code words following the first check symbols being added to the uncorrectable interleaved code words.

A method for correcting errors in data using interleaved Reed-Solomon coding, comprising the steps of:

• retrieving interleaved code words and corresponding extended check symbols from memory, the interleaved code words having interleaved check symbols;
• decoding the interleaved code words;
• identifying one or more uncorrectable interleaved code words having one or more uncorrectable errors based upon the step of decoding;
• generating, from the extended check symbols, first check symbols relating to the one or more uncorrectable interleaved code words following the step of identifying, the first check symbols being added to the one or more uncorrectable interleaved code words to form one or more extended interleaved code words;
• and
• decoding the one or more extended interleaved code words following the step of generating.

A computer software product embodying program instructions for execution by a processing unit for retrieving information from a memory, the computer software product including instructions stored on a computer medium which, when executed by the processing unit, operate to:

• retrieve interleaved code words and corresponding extended check symbols from memory, the interleaved code words having interleaved check symbols;
• decode the interleaved code words;
• identify one or more uncorrectable interleaved code words having one or more uncorrectable errors based upon the decoding;
• generate, from the extended check symbols, first check symbols relating to the one or more uncorrectable interleaved code words following the step of identifying, the first check symbols being added to the one or more uncorrectable interleaved code words to form one or more extended interleaved code words;
• and
• decode the one or more extended interleaved code words following the generating.