Voltage Overscaling (VOS) is one of the well-known techniques to increase the energy efficiency of arithmetic units. Also, it can provide significant lifetime improvements, while still meeting the accuracy requirements of inherently error-resilient applications. This paper proposes a generic accuracy-configurable multiplier that employs the VOS at a coarse-grained level (block-level) to reduce the control logic required for applying VOS and its associated overheads, thus enabling a high degree of trade-off between energy consumption and output quality. The proposed configurable Block-Level VOS-based (BL-VOS) multiplier relies on employing VOS in a multiplier composed of smaller blocks, where applying VOS in different blocks results in structures with various output accuracy levels. To evaluate the proposed concept, we implement 8-bit and 16-bit BL-VOS multipliers with various blocks width in a 15-nm FinFET technology. The results show that the proposed multiplier achieves up to 15% lower energy consumption and up to 21% higher output accuracy compared to the state-of-the-art VOS-based multipliers. Also, the effects of Process Variation (PV) and Bias Temperature Instability (BTI) induced delay on the proposed multiplier are investigated. Finally, the effectiveness of the proposed multiplier is studied for two different image processing applications, in terms of quality and energy efficiency.

翻译：电压过压调制（VOS）是提升算术单元能效的成熟技术之一。该技术可在满足固有容错应用精度需求的同时，显著延长器件使用寿命。本文提出一种通用精度可配置乘法器，该乘法器在粗粒度层级（模块级）采用VOS技术，从而减少应用VOS所需的控制逻辑及其相关开销，实现能耗与输出质量间的高度权衡。所提出的可配置模块级VOS（BL-VOS）乘法器通过将VOS应用于由较小模块构成的乘法器中实现，其中对不同模块施加VOS将产生具有不同输出精度等级的结构。为评估所提概念，我们采用15纳米FinFET工艺实现了具有不同模块宽度的8位和16位BL-VOS乘法器。结果表明，与现有最先进的VOS乘法器相比，所提乘法器能耗降低高达15%，输出精度提升高达21%。同时，研究了工艺偏差（PV）和偏置温度不稳定性（BTI）引起的延迟对所提乘法器的影响。最后，从图像质量与能效两个维度，评估了所提乘法器在两种不同图像处理应用中的有效性。