An Accuracy Tunable Non-Boolean Co-Processor Using Coupled Nano-Oscillators

Abstract

As we enter an era witnessing the closer end of Dennard scaling, where further reduction in power supply-voltage to reduce power consumption becomes more challenging in conventional systems, a goal of developing a system capable of performing large computations with minimal area and power overheads needs more optimization aspects. A rigorous exploration of alternate computing techniques, which can mitigate the limitations of Complementary Metal-Oxide Semiconductor (CMOS) technology scaling and conventional Boolean systems, is imperative. Reflecting on these lines of thought, in this article we explore the potential of non-Boolean computing employing nano-oscillators for performing varied functions. We use a two coupled nano-oscillator as our basic computational model and propose an architecture for a non-Boolean coupled oscillator based co-processor capable of executing certain functions that are commonly used across a variety of approximate application domains. The proposed architecture includes an accuracy tunable knob, which can be tuned by the programmer at runtime. The functionality of the proposed co-processor is verified using a soft coupled oscillator model based on Kuramoto oscillators. The article also demonstrates how real-world applications such as Vector Quantization, Digit Recognition, Structural Health Monitoring, and the like, can be deployed on the proposed model. The proposed co-processor architecture is generic in nature and can be implemented using any of the existing modern day nano-oscillator technologies such as Resonant Body Transistors (RBTs), Spin-Torque Nano-Oscillators (STNOs), and Metal-Insulator Transition (MITs) . In this article, we perform a validation of the proposed architecture using the HyperField Effect Transistor (FET) technology-based coupled oscillators, which provide improvements of up to 3.5× increase in clock speed and up to 10.75× and 14.12× reduction in area and power consumption, respectively, as compared to a conventional Boolean CMOS accelerator executing the same functions.