O-tree representation of non-slicing floorplan and its applications

Pei Ning Guo*, Chung Kuan Cheng, Takeshi Yoshimura

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingChapter

328 Citations (Scopus)


We present an ordered tree, O-tree, structure to represent non-slicing floorplans. We define an admissible placement as a compacted placement in both x and y direction. For each admissible placement, we can find an O-tree representation. We show that the number of possible O-tree combinations is O(n! 2 2n-2/n 1.5). This is very concise compared to a sequence pair representation which has O((n!) 2) combinations. The approximate ratio of sequence pair and O-tree combinations is O(n 2 (n/4e) n). The complexity of O-tree is even smaller than a binary tree structure for slicing floorplan which has O(n! 2 5n-3/n 1.5) combinations. Given an O-tree, it takes only linear time to construct the placement and its constraint graph. We have developed a deterministic floorplanning algorithm utilizing the structure of O-tree. Empirical results on MCNC benchmarks show promising performance with average 16% improvement in wire length, and 1% less in dead space over previous CPU-intensive cluster refinement method.

Original languageEnglish
Title of host publicationProceedings - Design Automation Conference
Number of pages6
Publication statusPublished - 1999
Externally publishedYes
EventProceedings of the 1999 36th Annual Design Automation Conference (DAC) - New Orleans, LA, USA
Duration: 1999 Jun 211999 Jun 25


OtherProceedings of the 1999 36th Annual Design Automation Conference (DAC)
CityNew Orleans, LA, USA

ASJC Scopus subject areas

  • Hardware and Architecture
  • Control and Systems Engineering


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