A Low Overhead Auto-Optimizing Bus Encoding Scheme for Low Power Data Transmission

Abstract

In this paper a new adaptive system bus encoding technique is presented which reduces the power dissipation on a bus by minimizing the weight of the encoded data stream. It is based on dynamically auto-optimizing code tables which are used to map data words unambiguously to code words. The proposed encoding scheme is highly efficient due to its ability to adapt to varying statistical parameters of the data streams to be encoded. Unlike other adaptive techniques presented to date, which are infeasible to implement into hardware due to their tremendous overhead in self dissipated power, the implementation of our encoding technique requires less hardware overhead and does not modify the system bus interface. The fundamentals of the encoding scheme and a hardware-efficient implementation are given. Experimental results showed a reduction in bus transition activity of up to 38%.

This work is sponsored by the DFG within the joint project VIVA under MU 1024/5-2.