Patent ID: 6621427
Filing Date: 2003-09-16
Classification: H03M

Abstract:
A method for encoding a dataword into a current codeword in a stream of codewords, wherein each codeword in the stream has a substantially equal number of ones and zeros, and wherein each transition between codewords involves a substantially equal number of rising and falling transitions, the method comprising:receiving the dataword; and creating the current codeword from the dataword and a preceding codeword in the stream by inverting substantially half of the zero bits of the preceding codeword and inverting substantially half of the one bits of the preceding codeword; wherein inverting substantially half of the zero bits and substantially half of the one bits involves, using the dataword to select one bits and the zero bits to invert, determining locations of the one bits and zero bits in the preceding codeword, and inverting the selected one bits and zero bits in the preceding codeword to form the current codeword.