Patent ID: 6130629
Filing Date: 2000-10-10
Classification: G11B,H04L

Abstract:
Apparatus for encoding three bytes of binary data as a 24/25 (0,9) codeword, the apparatus comprising:a storage circuit, coupled to an input stream to receive the three bytes, to store the first and second bytes as first and second bit strings and the third byte as first and second nibbles;a processor, coupled to the storage circuit, adapted to determine, in accordance with a 16/17 (0,5) code construction, whether each of the first and second bit strings contains at least one code violation, each code violation corresponding to a given bit sequence, the processor identifying a type and a position of the code violation;an encoder circuit, coupled to an input stream to receive the two bytes from the storage circuit, adapted to insert a pivot bit between the first and second strings and encode the first and second bit strings with the pivot bit inserted therebetween into a 16/17 (0,5) codeword based on the type and the position of each code violation identified by the processor,wherein the encoder circuit encodes by correcting, as necessary, any code violation in the first and second bit strings by 1) setting the inserted pivot bit to a first value, 2) defining values for a bit in each of the first and second bit strings as additional pivot bits, the additional pivot bits identifying the type and the position of each code violation, 3) preserving values for bits not included in the given bit sequence corresponding to the code violation, and 4) assigning values, as necessary, for one or more bits of the given bit sequence; anda word interleaver adapted to insert the first and second nibbles of the third byte adjacent to the additional pivot bits of the first and second bit strings in the 16/17 (0,5) codeword, respectively, to produce the 24/25 (0,9) codeword.