Adaptive encoder/decoder

A method comprising:

• forming a first sub-codeword that comprises data and data parity;
• forming a second sub-codeword that comprises mode information and mode parity;
• storing the first sub-codeword and the second sub-codeword in non-transitory storage;
• accessing at least the first sub-codeword and the second sub-codeword from the non-transitory storage;
• decoding the second sub-codeword that was accessed from the non-transitory storage to obtain the mode information;
• and
• decoding the first sub-codeword that was accessed from the non-transitory storage based on the mode information, including using a first decoding technique when the mode information indicates a normal data mode and using a second decoding technique when the mode information indicates a special data mode.

A storage device comprising:

• volatile memory;
• data encoding means for encoding data to generate data parity;
• mode encoding means for encoding mode information to generate mode parity;
• codeword forming means for forming a first sub-codeword that comprises the data and the data parity, the codeword forming means further for forming a second sub-codeword that comprises the mode information and the mode parity;
• codeword storing means for storing the first sub-codeword and the second sub-codeword in the volatile memory;
• codeword reading means for accessing the first sub-codeword and the second sub-codeword from the volatile memory;
• mode decoding means for decoding the second sub-codeword that was accessed from the volatile memory to obtain the mode information;
• and
• data decoding means for decoding the first sub-codeword that was accessed from the volatile memory based on the mode information, the data decoding means comprising normal data decoding means for decoding the first sub-codeword in response to the mode information indicating a normal data mode, the data decoding means comprising special data decoding means for decoding the first sub-codeword in response to the mode information indicating a special data mode.