Automated Rip-Up and Reroute Techniques

The ultimate goal of all automated routing systems is to interconnect 100% of the necessary point-to-point electrical connections. However, most automated routing systems fail to find acceptable paths for all required connections because of limited routing resources or problem complexity. Therefore, a cleanup phase is often necessary. During this cleanup phase, connectivity can be improved through a variety of manual and automated techniques. This paper concentrates on one automated technique, rip-up and reroute. Various rip-up and reroute strategies are discussed and evaluated, and experimental results are provided.