Design, Verification, Test and In-Field Implications of Approximate Computing Systems

Today, the concept of approximation in computing is becoming more and more a “hot topic” to investigate how computing systems can be more energy efficient, faster, and less complex. Intuitively, instead of performing exact computations and, consequently, requiring a high amount of resources, Approximate Computing aims at selectively relaxing the specifications, trading accuracy off for efficiency. While Approximate Computing gives several promises when looking at systems’ performance, energy efficiency and complexity, it poses significant challenges regarding the design, the verification, the test and the in-field reliability of Approximate Computing systems. This tutorial paper covers these aspects leveraging the experience of the authors in the field to present state-of-the-art solutions to apply during the different development phases of an Approximate Computing system

Design Space Exploration of Approximate Computing Techniques

Nowadays, the rising energy consumption of smartphones and portable devices creates an energy efficiency challenge. To address this problem, Approximate Computing (AxC) techniques are becoming popular since they sacrifice computation accuracy for enhanced performance, energy efficiency, and area reduction. However, selecting suitable AxC techniques for target applications remains intricate. Design Space Exploration (DSE) approaches can be employed to systematically explore all different possible approximate versions of an application and select the most suitable versions. This paper proposes a DSE approach that models the target application computations and the approximation-induced errors using Interval Arithmetic. The experimental results show the efficiency of the proposed approach in quickly evaluating different approximate versions of an application eliminating the time-consuming task of executing each approximate version. Also, using Artificial intelligence, such as Reinforcement Learning approaches, is proposed to explore the design space automatically