Transition inversion coding with parity check for off-chip serial transmission

Transition inversion coding (TIC) can reduce serial bus power dissipation by negating the even-numbered bits of a data word if the number of transitions in the data word is larger than half its word length. The codewords generated by TIC also enable up to a certain error detection rate. This paper proposes a method called PTIC that uses a parity bit along with TIC to achieve 100% single-bit error detection rate. Our implementation of PTIC achieves 7.4% power saving per bit transmission for an I/O driving a load of 30pF. We also work out the formulas for computing the transition activity of uniformly and randomly distributed data encoded by TIC and PTIC.