Given the stringent requirements of energy efficiency for Internet-of-Things edge devices, approximate multipliers have recently received growing attention, especially in error-resilient applications. The computation error and energy efficiency largely depend on how and where the approximation is introduced into a design. Thus, this article aims to provide a comprehensive review of the approximation techniques in multiplier designs ranging from algorithms and architectures to circuits. We have implemented representative approximate multiplier designs in each category to understand the impact of the design techniques on accuracy and efficiency. The designs can then be effectively deployed in high level applications, such as machine learning, to gain energy efficiency at the cost of slight accuracy loss.

翻译：鉴于物联网边缘设备对能效的严苛要求，近似乘法器近年来受到越来越多的关注，尤其是在容错应用中。计算误差和能效很大程度上取决于近似以何种方式及在设计的哪个阶段引入。因此，本文旨在对乘法器设计中的近似技术（涵盖从算法、架构到电路的各个层面）进行全面综述。我们实现了每一类中具有代表性的近似乘法器设计，以理解设计技术对精度和能效的影响。这些设计随后可有效部署于机器学习等高层应用中，以轻微的精度损失为代价换取能效提升。