Signature Codes for Energy-Efficient Data Movement in On-chip Networks

On-chip networks provide a scalable infrastructure for moving data among cores in many-core systems. In future technologies, significant amounts of dynamic energy are dissipated for data movement on on-chip links. This paper proposes Sig-NoC, a predictable approach via signature encoding and transition signaling to reduce switching activity on links. Also, we show that link energy dominates in future technologies. Sig-NoC makes the switching activity proportional to the number of 1s per data in the source by using transition signaling. We estimate the energy of each packet at the source of routing in NoC. Therefore, we reduce the number of 1s for high energy packets through signature coding in the source. Sig-NoC mechanism encodes the packets once at the source and decodes them at the destination only; therefore, it has virtually no impact on performance. Simulation results on NAS and Phoenix benchmark suits on 4X4 NoC indicate that Sig-NoC achieves an average of 28% reduction in the overall NoC energy.