Table of Contents
VLSI Design
Volume 10, Issue 2, Pages 169-176

An ILP Formulation for Minimizing the Number of Feedthrough Cells in a Standard Cell Placement

Computer Systems Research Center, National Chiao Tung University, Taiwan, Hsinchu, China

Received 17 November 1996; Accepted 20 March 1998

Copyright © 1999 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


It is well known that standard cells have been widely used to implement VLSI circuits in the automation of physical design. Since one major aim of a cell-based design is to minimize total layout area in a standard cell placement, the number of feedthrough cells will be minimized to reduce total cell area in a standard cell placement. In this paper, first, we model a partitioning-based row assignment (PRA) problem to minimize the number of feedthrough cells in a standard cell placement. Furthermore, an integer linear programming (ILP) approach is proposed to solve the PRA problem in a standard cell placement. Finally, the ILP approach has been implemented and two standard-cell netlists, Primary 1 and Primary 2, have been tested by the proposed approach, Bose's approach [4] and an exhaustive search approach, respectively. The experimental results show that the ILP approach obtains fewer feedthrough cells than Bose's approach in a partitioning-based standard cell placement.