US Patent 7613838 Low overhead coding with arbitrary control code placement

A physical layer device of a network device comprises a physical coding sublayer (PCS) device encodes data to produce an encoded data block. A scrambler communicates with the PCS device and scrambles the encoded data block to produce a scrambled data block. A sync adder adds a sync header to the scrambled data block. The sync header has a first state when the scrambled data block only includes data portions. The sync header has a second state when the scrambled data block includes at least one control code portion.