A Rule-Based High Efficient Obstacle-Avoiding RSMT Algorithm for VLSI Routing

For VLSI physical design, the routing problem has attracted attention in recent years due to the emerging manufacturing technologies. Tree generation is one key routing step directly affecting the routing quality, which is to find the rectilinear steiner minimal tree (RSMT) of each net. Ordinary RSMT algorithms such as FLUTE fail to generate valid trees avoiding obstacles. In contrast, current obstacle-avoiding RSMT (OARSMT) algorithms can incur a large runtime overhead compared with FLUTE. To reduce the runtime cost while maintaining the quality, a novel OARSMT algorithm is proposed in this work. By proposing multiple rule-based routing schemes, which are fast while maintaining the awareness of global conditions from mature RSMT solutions, OARSMT solutions with reasonable qualities can be quickly obtained, even for large and complicated cases. Compared with the state-of-the-art works, traded with limited wirelength overhead, the proposed algorithm has ∼10x-2700x and ∼150x-5800x runtime speedup under randomized testcases and standard benchmarks, respectively.