High Speed Digital Circuit Design Using Output Prediction Logic

C. Sechen

Abstract

I will present output prediction logic (OPL), a technique that can be applied to conventional CMOS logic families to obtain considerable speedups. When applied to static CMOS, OPL retains the restoring character of the logic family, including its high noise margins. Speedups of 2X to 3X over (optimized) conventional static CMOS are demonstrated for a variety of circuits, ranging from chains of gates, to datapath circuits, and to random logic benchmarks. Such speedups are obtained using identical netlists without remapping. When applied to pseudo-nMOS and dynamic families, in combination with remapping to wide-input NORs, OPL yields speedups of 4X to 5X over static CMOS. Since OPL applied to static CMOS is faster than conventional domino logic, and since it has higher noise margins than domino logic, we believe it will scale much better than domino with future processing technologies.