Deflection Routing in 3D Network-on-Chip with Limited Vertical Bandwidth

Abstract

This article proposes a deflection routing for 3D NoC with serialized TSVs for vertical links. Compared to buffered routing, deflection routing provides area-and power-efficient communication and little loss of performance under low to medium traffic load. Under 3D environments, the deflection routing can yield even better performance than buffered routing when key aspects are properly taken into account. However, the existing deflection routing technique cannot be directly applied because the serialized TSV links will take longer time to send data than ordinary planar links and cause many problems. A naive deflection through a TSV link can cause significantly longer latency and more energy consumption even for communications through planar links. This article proposes a method to mitigate the effect and also solve arising deadlock and livelock problems. Evaluation of the proposed scheme shows its effectiveness in throughput, latency, and energy consumption.