FLUTE: Fast Lookup Table Based Rectilinear Steiner Minimal Tree Algorithm for VLSI Design

Abstract-- In this paper, we present a very fast and accurate rectilinear Steiner minimal tree (RSMT) algorithm called FLUTE. FLUTE is based on pre-computed lookup table to make RSMT construction very fast and very accurate for low-degree1 nets. For high-degree nets, a net breaking technique is proposed to reduce the net size until the table can be used. A scheme is also presented to allow users to control the tradeoff between accuracy and runtime. FLUTE is optimal for low-degree nets (up to degree 9 in our current implementation) and is still very accurate for nets up to degree 100. So it is particularly suitable for VLSI applications in which most nets have a degree 30 or less. We show experimentally that over 18 industrial circuits in the ISPD98 benchmark suite, FLUTE with default accuracy is more accurate than the Batched 1-Steiner heuristic and is almost as fast as a very efficient implementation of Prim's rectilinear minimum spanning tree (RMST) algorithm.

• Type: Journal
• Year: 2008
• Where: TCAD
• Authors: Chris C. N. Chu, Yiu-Chung Wong
• Keywords: Accurate Rectilinear Steiner, FLUTE, Pre-computed Lookup Table, TCAD 2008