VOSsim: A Framework for Enabling Fast Voltage Overscaling Simulation for Approximate Computing Circuits

Approximate computing emerges as a new design paradigm for generating energy-efficient computing systems. Voltage overscaling (VOS) forms a very promising technique to generate approximate circuits, and its application in cooperation to other approximate techniques is proven to lead to more efficient solutions. However, the existing design tools fail to provide effective voltage-aware simulation for early exploration of power-error approximate design tradeoffs. In this brief, we propose VOSsim, a framework that extends state-of-the-art industry strength tools, to enable fast and accurate simulations of voltage overscaled circuits. We extensively evaluate VOSsim showing that it attains 99.2% output and 98.4% power accuracy, with an average speedup of 32× in simulation time compared to high-precision SPICE simulations, i.e., the only available solution today for VOS-aware simulation.