Optimizing the antenna area and separators in layer assignment of multi-layer global routing

Wen-Hao Liu, Yih-Lang Li
2012 Proceedings of the 2012 ACM international symposium on International Symposium on Physical Design - ISPD '12  
Traditional solutions to antenna effect, such as jumper insertion and diode insertion performed at post-route stage may produce extra vias and degrade circuit performance. Previous work suggests combining layer assignment, jumper insertion, and diode insertion together to achieve a better design quality with less additional cost. Based on our observations on global and local antenna violations, this paper proposes an antenna-safe single-net layer assignment (AS-SLA), which first enumerates all
more » ... ntenna-safe layer assignment solutions of a net, and then extracts the minimum-cost one for the net. AS-SLA can minimize via count and separators as well. In addition, an antenna avoidance layer assignment flow (AALA) adopting AS-SLA as its kernel not only avoids global antenna violations, but also eliminates local antenna violations. Experimental results reveal that, in 16 benchmarks, AALA can yield ten antennaviolation-free assignments, while the algorithms of other works yield no antenna-violation-free assignment. However, AALA performs about seven times slower than other antenna-aware layer assignment algorithm. Accordingly, two acceleration techniques are proposed to reduce the runtime of AALA by 57.6%.
doi:10.1145/2160916.2160946 dblp:conf/ispd/LiuL12 fatcat:4wifrmm5xrh4romklccrlwvpem