Critical-trunk based obstacle-avoiding rectilinear Steiner tree routings for delay and slack optimization

Yen Hung Lin*, Shu Hsin Chang, Yih-Lang Li

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Scopus citations


Obstacle-avoiding rectilinear Steiner tree (OARST) construction is a fundamental problem associated with the trend toward IP-block-based System-on-Chip designs. The objective of previous studies on obstacle-avoiding rectilinear Steiner minimal tree (OARSMT) has been to minimize the total wirelength of the constructed Steiner tree. Studies of performance-driven Steiner trees have demonstrated that the minimization of wirelength may worsen the performance of the Steiner tree. This work is the first to construct OARST while considering the Elmore delay. A critical-trunk-based tree growth mechanism is proposed. The critical trunks are constructed by extended single-source single-target maze routing called multi-source single-target maze routing. The unconnected pins are connected to critical trunks under the delay constraints of every sink. The proposed critical trunk can be applied to solve performance-driven and slack-driven OARST problems. Experimental results demonstrate that the proposed algorithms achieve an average 24.12% improvement in the maximum delay over OARSMT in performance-driven OARST problem and successfully solve 66.67% worst negative slack (WNS) violations in slack-driven OARST problem while running faster than previous OARSMT algorithms.

Original languageEnglish
Title of host publicationProceedings of the 2009 International Symposium on Physical Design, ISPD'09
Number of pages8
StatePublished - 21 Sep 2009
Event2009 International Symposium on Physical Design, ISPD'09 - San Diego, CA, United States
Duration: 29 Mar 20091 Apr 2009

Publication series

NameProceedings of the International Symposium on Physical Design


Conference2009 International Symposium on Physical Design, ISPD'09
Country/TerritoryUnited States
CitySan Diego, CA


  • Elmore delay model
  • Obstacle-avoiding rectilinear Steiner tree
  • Performance-driven routing
  • Timing constraint
  • Worst negative slack


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