We study in this paper the feed-through pin assignment problem for cell-based design that
assigns global nets to feed-through cells or implicit feed-through ports. On a single row, for a
restricted permutation of global nets, we develop a graph theoretic approach for optimally
minimizing the density of the channel above (below) the row subject to the bound on the
density of the channel below (above) the row. Based on this technique, an approach for
iteratively improving style in which there is an over-the-cell feed-through layer.

We study in this paper the feed-through pin assignment problem for cell based design that
assigns global nets to feed-through cells or implicit feed-through ports. On a single row, for a
restricted permutation of global nets, we develop a graph theoretic approach for optimally
minimizing the density of the channel above (below) the row subject to the bound on the
density of the channel below (above) the row. Based on this technique, an approach for
iteratively improving multiple row feed-through pin assignment can be developed. We show …