3D network-on-chip with wireless links through inductive coupling

Utilizing network-on-chips for manycore SoCs has already been studied widely, as traditional bus-based architectures are unlikely to endure so many inter-core communications. Since device scaling has come to a limit, the technology trend now is stacking dies three-dimensionally to obtain more silicon area and shorter wire length. The most challenging part for making a 3D chip is inter-layer communication method. Currently, TSV is the most popular and promising technique to provide the best performance. However, it suffers from many problems due to inter-layer wiring. As a substitute, inductive coupling can be used as a reliable and non-expensive technology. In this work, we use inductive coupling for the inter-layer communication to build a 3D NoC. We also propose a token bus protocol for an efficient implementation of multi-layer communications. Experimental results show that the proposed architecture achieves maximum throughput of 4.7 flits/cycle under uniform random traffic.