Pseudo pin assignment for single-layer over-the-cell routing

Abstract

In a CMOS double metal gate-array technology, only the M2 layer is available for over-the-cell routing. A systematic algorithm that intelligently converts global wires into pseudo-pins and assigns them to each row of cells is presented. The final positions of pseudo-pins provide a feasible solution for one-layer routing over the cells and minimize wire densities in the adjacent two-layer routing channels.