Precoded two-dimensional coding method for low-power serial bus

Abstract

A precoded two-dimensional coding method is proposed for a low-power serial bus, which reduces the transition activity in time as well as in space without causing error propagation. In the conventional limited-weight codes for low-power I/O exploiting transition signalling, once single-bit random errors occur in noisy bus channels, they are propagated to subsequent signals (because the present signal level is dependent on the preceding signal level in time). The proposed method avoids this phenomenon by producing a precoded bit matrix. Furthermore it eliminates the need for additional hardware for the transition signalling.