SAT-Based On-Track Bus Routing

In modern integrated circuit design, bus routing is a challenge because of complex design rules and wiring constraints. Despite extensive research, state-of-the-art in bus routing is not effective when nonuniform tracks, various obstacles, wire width constraints, and multiple spacing rules should be handled simultaneously. A new bus routing framework proposed in this article is based on maze routing and Boolean satisfiability. It produces high-quality results quickly and allows for additional optimizations, such as minimizing wire length on the critical paths. A number of challenging bus routing benchmarks appeared in 2018 ICCAD Contest. Experiments on these benchmarks not only show that the framework is faster than the winners of the competition and previous work but also produces better results, improving the overall cost by 12% while at the same time minimizing the number of spacing violations.