Logic extraction based on normalized netlengths

Abstract

We present a cost function which can be used to minimize the routing contribution of a circuit during logic synthesis. Instead of estimating the absolute routing cost of a net, this function captures the relative routing costs of nets based on the number of terminals on the nets. Unlike the routing cost functions proposed earlier, the proposed cost function does not require layout-parameters or any tuning of the variables to achieve acceptable estimation of the routing cost. The usefulness of the proposed routing cost is verified by minimizing it during the process of logic extraction in logic synthesis, leading to an average of 10% improvement in the routing area and 8% improvement in the chip area at no performance loss.