Abstract: A method and apparatus are provided for storing data. The method and apparatus generate a plurality of ECC codewords, which define a cooperative block. Each ECC codeword includes a plurality of information symbols and first and second sets of corresponding redundancy symbols. Shared redundancy symbols are generated for the cooperative block based on a combination of the second sets of redundancy symbols from the plurality of ECC codewords. A respective set of parity codewords is generated for the cooperative block based on the shared redundancy symbols. The second set of redundancy symbols for each ECC codeword in the cooperative block is derivable from the parity codewords. The cooperative block and the respective parity codewords are stored, without the second set of redundancy symbols, on a storage medium.

Abstract: A method and apparatus are provided for decoding a sequence of code words into a sequence of data words. Each code word includes an encoded data word and an indicator bit. The encoded data word is extracted unchanged into a respective unencoded data word if an indicator bit has a first binary value and is extracted into the unencoded data word and then complemented if the indicator bit has a second, opposite binary value.

Abstract: A method and apparatus are provided for encoding successive data words into respective code words. Each data word is mapped into data segments that are constrained to a first number of bit patterns, which is less than a second number of bit patterns that satisfy a first constraint. The data segments are encoded into intermediate code word segments selected from a first set of the bit patterns that satisfy the first constraint, wherein at least some of the bit patterns in the first set violate a second constraint. The intermediate code word segments are encoded into respective code word segments by encoding the intermediate code word segments that violate the second constraint with code word segments selected from a second, different set of the bit patterns that satisfy the first constraint and the second constraint.

Abstract: A codeword for use in a communication channel is provided. A first segment of the codeword includes a plurality of bits having a running digital sum (RDS) and a second segment includes a plurality of bits based on the RDS of the first segment.

Abstract: An encoding system for encoding digital data for transmission through a communication channel is described, which includes a DCF encoder and a parity encoder operatively coupled to the DCF encoder. The DCF encoder is adapted to receive a first data sequence, and to generate a first DCF code word and a new running digital sum as functions of the first data sequence and a pre-existing running digital sum, wherein the new running digital sum is limited to a maximum absolute value. The parity encoder is operatively coupled to the DCF encoder, and adapted to receive the first DCF code word from the DCF encoder, and to generate a first interleaved parity code word as a function of the first DCF code word, and to provide the first interleaved parity code word to a channel.

Abstract: A method and apparatus are provided for encoding and decoding digital information. A sequence of data words is received, wherein each data word has a running digital sum (RDS). The sequence of data words is encoded into a sequence of corresponding code words, which has a current RDS. For each data word a binary symbol is added to the data word and the data word is selectively complemented as a function of the RDS of the data word and the current RDS of the sequence of code words to form the corresponding code word.

Abstract: A method and apparatus are provided for encoding digital information. A sequence of successive data words are encoded into a sequence of successive code words according to a code, such that a running digital sum (RDS) of the sequence of successive code words is bounded and is constrained to predetermined, non-adjacent values at boundaries between the code words.