Rate 64/65 (d=0, G=11/I=10) run length limited modulation code

A method for encoding a sequence of r bit digital data words into a sequence of codewords having (r+1) bits, comprising:

• dividing each r bit digital data word into a first n-bit byte, a second n-bit byte, and a remainder of m other n-bit bytes;
• encoding the first and second n-bit bytes to form a (2n+1)-bit word;
• forming p k-bit intermediate blocks from the (2n+1)-bit word and a portion of the m other n-bit bytes, a remainder of the m other n-bit bytes including uncoded and unconstrained bits;
• encoding the p k-bit intermediate blocks;
• and
• concatenating the p encoded k-bit intermediate blocks and the uncoded and unconstrained bits to form a (r+1) bit codeword.

A method for encoding a sequence of r bit digital data words into a sequence of codewords having (r+1) bits, comprising:

• dividing each r bit digital data word into n-bit bytes;
• encoding two n-bit bytes to form a (2n+1)-bit word;
• forming p k-bit intermediate blocks from the n-bit bytes;
• encoding the p k-bit intermediate blocks;
• and
• concatenating the p encoded k-bit intermediate blocks and uncoded and unconstrained bits from the r bit digital data word to form a (r+1) bit codeword,
• the (r+1) bit codeword satisfying a predetermined minimum zero run length (d) constraint, a predetermined maximum zero run length (G) constraint, and a predetermined maximum interleave zero run length (I) coding constraint, in which d=0, G=11, and I=10,
• the constraints holding both for concatenated intermediate blocks and for no intermediate blocks.

A method for decoding a sequence of (r+1) bit encoded codewords into a sequence of r bit digital data words bits, comprising:

• dividing the (r+1) bit encoded codeword into p k-bit intermediate blocks and unconstrained and uncoded bits;
• decoding the p k-bit intermediate blocks separately;
• decoding (2n+1) bits of the p k-bit intermediate blocks to form two n-bit bytes;
• and
• dividing each of remaining (r−2n) bits from both the decoded p k-bit intermediate blocks and the unconstrained and uncoded bits into t n-bit bytes.

A method for decoding a sequence of 65 bit encoded codewords into a sequence of 64 bit digital data words bits, comprising:

• dividing a 65 bit encoded codeword into five 11-bit intermediate blocks and unconstrained and uncoded bits;
• decoding the five 11-bit intermediate blocks separately;
• dividing the five 11-bit intermediate blocks into a 17 bit section and a 38 bit section,
• decoding 17 bits of the 17 bit section to form two 8-bit bytes;
• and
• dividing the 38 bit section and the unconstrained and uncoded bits into six 8-bit bytes.