An optimal pin assignment algorithm with improvement of cell placement in standard cell layout

In this paper, we propose an optimal pin assignment algorithm with improvement of cell placement in standard cell layout. The objective of the algorithm is to minimize the channel density by assigning nets to terminals of cells. If the number of possible terminal assignments for each cell is bounded by some constant r, then the proposed algorithm runs in linear time. In most practical cases, the value of r is relatively small, and thus the proposed algorithm is effective and efficient to reduce the chip area.