Obstacle-avoiding rectilinear Steiner minimum tree construction based on Discrete Particle Swarm Optimization

The obstacle-avoiding rectilinear Steiner minimum tree (OARSMT) problem is one of the fundamental problems in the physical design of Very Large Scale Integrated (VLSI) circuits, especially in routing, which is known to be NP-complete. It becomes more important than ever for VLSI designs which need to consider numerous obstacles such as macro cells, IP blocks and pre-routed nets. Particle Swarm Optimization (PSO) has been proved to be an efficient intelligent algorithm for optimization designs. In this paper, an improved Discrete Particle Swarm Optimization (DPSO) algorithm is proposed for solving the OARSMT problem optimally. Meanwhile, the corresponding evaluation function and the operators inspired from the Genetic Algorithm (GA) are designed. The obstacle-avoiding measure is then presented to construct an OARSMT, which avoiding obstacles by generate virtual vertexes of the real vertexes. Experimental results on several benchmarks show that the proposed method achieves good performance in routing optimization significantly.