FV-MSB: A Scheme for Reducing Transition Activity on Data Buses

Power consumption becomes an important issue for modern processors. The off-chip buses consume considerable amount of total power [9,7]. One effective way to reduce power is to reduce the overall bus switching activities since they are proportional to the power. Up till now, the most effective technique in reducing the switching activities on the data buses is Frequent Value Encoding (FVE) that exploits abundant frequent value locality on the off-chip data buses. In this paper, we propose a technique that exploits more value locality that was overlooked by the FVE. We found that a significant amount of non-frequent values, not captured by the FVE, share common highordered bits. Therefore, we propose to extend the current FVE scheme to take bit-wise frequent values into consideration. On average, our technique reduces 48% switching activity. The average energy saving we achieved is 44.8%, which is 8% better than the FVE