EFMCC: a new combi-code for high-density optical recording
W. Coene, Ernest Chuang · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2000
EFMCC is a runlength-limited (RLL) channel code with EFM- like RLL constraints, d equals 2 and k equals 10, which is constructed by combining two codes, a main code and a substitution code. Both codes operate on a byte-by-byte basis. The substitution code has a special structure, i.e., for each byte, there are two possible channel words, which have opposite parity and the same next-state in the finite- state machine of the EFMCC code. The benefits are: guaranteed DC-control, 4% higher efficiency than EFMPlus, and simple byte-oriented look-ahead DC-control encoding.