Adaptive multi-voltage scaling in wireless NoC for high performance low power applications

Networks-on-Chip (NoCs) have garnered significant interest as communication backbone for multicore processors used across a wide range of fields that demand higher computation capability. Wireless NoCs (WNoCs) by augmenting single hop, long range wireless links with wired interconnects; offer the most promising solution to reduce multi-hop long distance communication bottlenecks and opens up innumerable possibilities of topological innovations that are not possible otherwise. However, energy consumption in routers along with Wireless Interface (WI) components still remains considerably high. Specifically for large systems with many nodes in the network, a significant amount of energy is consumed by the communication infrastructure (routers, links, WIs). The usage of the routers and WIs are application dependent and for most cases performance requirements can be met without operating the whole communication infrastructure to its maximum limit. Dynamic reconfigurable systems that can switch between both high performance and low power modes can cater to wide range of applications. In this paper, we propose a novel design methodology for energy efficient WNoC using Adaptive Multi-voltage Scaling (AMS) that reduces dynamic power consumption, along with power gating to prevent static power dissipation in routers and WIs. We evaluate our proposed design in presence of real and synthetic traffic patterns. This approach saves up to 62.50% of static power with less than 1% area overhead. In different traffic scenarios, the proposed WNoC reduces overall packet energy dissipation up to 35% on average compared to a regular WNoC, without significant performance degradation. Design considerations for augmenting existing WNoCs with these routers and corresponding overheads are also presented.