This paper presents an efficient and practical approach to the Constrained Via Minimization (CVM) problem, which assigns wire segments to the layers, using the minimum number of vias, given a feasible partial routing. The feasible partial routing is first represented by a directed bipartite graph to reflect the mutual constraints. An energy function is then proposed to turn the problem into a cost optimization problem. An efficient heuristic algorithm, combining hill-climbing and simulated annealing, is developed for the cost optimization. The algorithm has the capability to escape from the local minimums and eventually reaches a near-optimal or optimal solution. The proposed method is practical as it can handle many practical constraints such as a multi-way wire split from a single via, and pre-allocation of power nets and terminals. Experimental results show that our proposed method is efficient in handling complex grid-based routing
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.