NTHU-Route 2.0: A fast and stable global router

We present in this paper a fast and stable global router called NTHU-Route 2.0 that improves the solution quality and runtime of a state-of-the-art router, NTHU-Route, by the following enhancements: (1) a new history based cost function, (2) new ordering methods for congested region identification and rip-up and reroute, and (3) two implementation techniques. The experimental results show that NTHU-Router 2.0 solves all ISPD98 benchmarks with very good quality. Moreover, it routes 7 of 8 ISPD07 benchmarks without any overflow. In particular, for one of the ISPD07 benchmarks which are thought to be difficult cases previously, NTHU-Route 2.0 can completely eliminate its total overflow. NTHU-Route 2.0 also successfully solves 12 of 16 ISPD08 benchmarks without causing any overflow.