Patent ID: 7038599

Claim:
A method for generating a channel code with DC control, said method comprising the steps of: converting a stream of P n-bit input words into a stream of P m-bit code words; and converting the stream of P m-bit code words into an output stream of P m-bit output words using a NRZI converter, characterized in that the method further comprises the steps of: determining a running digital sum of the output stream of output words; and in response to the running digital sum, replacing a sequence of Q m-bit code words, by a replacement sequence of Q m-bit replacement code words, the replacement sequence being equally long and having a different parity than the sequence of code words being replaced, and said replacement sequence never occurring in a stream of m-bit code words when converting any stream of n-bit input words into m-bit code words, and in that the replacement sequence is chosen from the following table: 1: 101 001 010 100 −> 100 100 100 100 2: 010 001 000 101 −> 010 000 000 101 3: 001 001 000 101 −> 001 000 000 101 4: 101 000 010 010 −> 100 100 000 010 5: 101 001 000 001 −> 100 100 000 001 6: 101 000 100 101 −> 101 000 000 101 7: 101 000 100 010 −> 101 000 000 010.