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：电压过缩放（VOS）是提升算术单元能效的成熟技术之一。该技术能在满足固有容错应用精度要求的同时，显著延长器件寿命。本文提出一种通用精度可配置乘法器，在粗粒度（块级）层次采用VOS技术，以此减少应用VOS所需的控制逻辑及其相关开销，从而实现能耗与输出质量的高度权衡。所提出的可配置块级VOS（BL-VOS）乘法器，其核心在于对由若干较小模块组成的乘法器施加VOS，通过在不同模块上应用VOS可产生不同输出精度的结构。为评估该概念，我们采用15纳米FinFET工艺实现了具有不同模块位宽的8位与16位BL-VOS乘法器。结果表明，与现有最先进的VOS乘法器相比，所提方案可降低能耗高达15%，同时输出精度提升21%。此外，本文还研究了工艺波动（PV）与偏置温度不稳定性（BTI）导致的延迟对所提乘法器的影响。最后，从图像质量与能效角度，通过两种不同图像处理应用验证了所提乘法器的有效性。