Dynamic and leakage power reduction of ASICs using configurable threshold logic gates

Abstract

This article demonstrates an unconventional approach to computing logic functions for use in ASICs, and a fully automated approach to technology mapping for standard cell ASICs using the new cells. The approach results in a significant reduction in power, leakage, area and wire-length, without sacrificing performance of the design. At the heart of this approach is a configurable threshold logic gate. Using a standard cell library of such gates, a new technology mapping algorithm is applied to automatically transform a given netlist into one with an optimal mixture of conventional logic gates and threshold gates. The mapping algorithm is based on logic decomposition of Boolean functions into specific threshold functions. This approach was used to fabricate a 32-bit signed 2-stage Wallace-Tree multiplier in a 65-nm LP technology. Simulation and chip measurement results of the multiplier show a 33% improvement in dynamic power at 30% switching activity, 24% lower core area, 45% lower wire-length and 50% lower leakage without any performance degradation, compared to a functionally equivalent, conventional standard cell implementation. Similar results are shown for a FIR filter, a 32-bit MIPS, a 128-bit AES encryption circuit and a floating-point multiplier.