Efficient Routing in Coarse-Grained Reconfigurable Arrays Using Multi-Pole NEM Relays

Abstract

In this paper, we propose the use of multi-pole nanoelectromechanical (NEM) relays for routing multi-bit signals within a coarse-grained reconfigurable array (CGRA). We describe a CMOS-compatible multi-pole relay design that can be integrated in 3-D and improves area utilization by 40% over a prior design. Additionally, we demonstrate a method for placing multiple contacts on a relay that can reduce contact resistance variation by 40 × over a circular placement strategy. We then show a methodology for integrating these relays into an industry-standard digital design flow. Using our multi-pole relay design, we perform post-layout simulation of a processing element (PE) tile within a hybrid CMOS-NEMS CGRA in 40 nm technology. We achieve up to 19% lower area and 10% lower power at iso-delay, compared to a CMOS-only PE tile. The results show a way to bridge the performance gap between programmable logic devices (such as CGRAs) and application-specific integrated circuits using NEMS technology.