A fast and high-performance global router with enhanced congestion control

Abstract

In global routing, congestion and running time are the key factors that affect the quality of the solution. With the rapid growth of integrated chip scale, striking a balance between running time and congestion has become a bottleneck in improving design quality. In this paper, we propose a highly efficient and effective global router to address this challenge. We first propose an efficient R-tree-based compatible routing region partitioning algorithm for collecting routable regions, which offers robust support for ideal parallel routing scheduling. Then, taking into account the effect of the barrel effect on congestion evaluation and the detrimental impact of loops, a congestion-driven initial parallel routing scheme is proposed to enhance routability in the triaxial pattern routing structure. After that, we develop an accurate congestion estimation model and an optimized path-searching scheme, which are instrumental in effectively managing smaller congestion gradient variations and guiding efficient congestion reduction. We evaluate the performance of our algorithm on the ISPD 2018 and ISPD 2019 contest benchmark suites and compare it with the state-of-the-art work. Experimental results show that our proposed algorithm significantly reduces 71% overflows, improving 65% running time, and the total wirelength is even smaller.