Evaluation of using inductive/capacitive-coupling vertical interconnects in 3D network-on-chip

In recent 3DIC studies, through silicon vias (TSV) are usually employed as the vertical interconnects in the 3D stack. Despite its benefit of short latency and low power, forming TSVs adds additional complexities to the fabrication process. Recently, inductive/capactive-coupling links are proposed to replace TSVs in 3D stacking because the fabrication complexities of them are lower. Although state-of-the-art inductive/capacitive-coupling links show comparable bandwidth and power as TSV, the relatively large footprints of those links compromise their area efficiencies. In this work, we study the design of 3D network-on-chip (NoC) using inductive/capacitive-coupling links. We propose three techniques to mitigate the area overhead introduced by using these links: (a) serialization, (b) in-transceiver data compression, and (c) high-speed asynchronous transmission. With the combination of these three techniques, evaluation results show that the overheads of all aspects caused by using inductive/capacitive-coupling vertical links can be bounded under 10%.