In this paper, we describe different ways to derive transistor networks from BDDs. The use of disjoint pull-up (composed of PMOS transistors) and pull-down (composed of NMOS transistors) planes allows simplifications that result in shorter pull-up and pull-down transistor stacks. The reduced length of transistor stacks leads to the fastest implementation among the six different strategies evaluated to generate transistor networks from BDDs. Delay and area results are presented showing the impact of the proposed strategy.

This paper presents a method for speeding-up ASICs by transistor reordering. The proposed method can be applied to a variety of logic styles and transistor topologies. The rationale of the obtained gains is explained through logical effort concepts. When applied to circuits based on 4-input networks, which is the case of many structured-ASIC or FPGA technologies, significant performance gains are obtained at a small area expense. This observation points out that our method can be of special interest when migrating FPGAs to ASICs. The logical effort effects on networks derived from BDDs illustrated in this paper can be exploited in a much broader range of designs.