An ILP formulation for minimizing the number of feedthrough cells in a standard cell placement

It is well known that standard cells have been widely used to implement VLS I circuits in the automation of physical design. Since one major aim of a c ell-based design is to minimize total layout area in a standard cell placem ent, 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 partit ioning-based row assignment (PRA) problem to minimize the number of feedthr ough cells in a standard cell placement. Furthermore, an integer linear pro gramming (ILP) approach is proposed to solve the PRA problem in a standard cell placement. Finally, the ILP approach has been implemented and two stan dard-cell net-lists, Primary 1 and Primary 2, have been tested by the propo sed approach, Bose's approach [4] and an exhaustive search approach,respect ively The experimental results show that the ILP approach obtains fewer fee dthrough cells than Bose's approach in a partitioning-based standard cell p lacement.