Smart-Hop Arbitration Request Propagation

Abstract

SMART-based NoC designs achieve ultra-low latencies by enabling flits to traverse multiple hops within a single clock cycle. Notwithstanding the clear performance benefits, SMART-based NoCs suffer from several shortcomings: each router must arbitrate among a quadratic number of requests, which leads to high costs; each router independently makes its own arbitration decisions, which leads to a problem called false negatives that causes throughput loss. In this article, we propose a new SMART-based NoC design called SHARP that overcomes these shortcomings. Our evaluation demonstrates that SHARP increases throughput by up to 19% and average link utilization by up to 24% by avoiding false negatives. By avoiding quadratic arbitration, our evaluation further demonstrates that SHARP reduces the wiring and area overhead significantly.