The rapid emergence of edge computing platforms and large-scale data centers has made power efficiency a primary design constraint, particularly for data-intensive and AI-driven workloads. Field-programmable gate arrays (FPGAs) are increasingly adopted due to their flexibility and potential for energy-efficient acceleration. However, FPGA supply voltages are typically fixed at design time using conservative margins, limiting the ability to adapt power consumption to runtime conditions. This paper presents VolTune, an open-source runtime voltage control architecture that enables runtime tuning of FPGA supply voltages through FPGA-integrated control logic that abstracts low-level PMBus operations. VolTune provides both hardware-based and software-based control paths, allowing designers to balance deterministic low-latency operation against programmability. In the presented prototype, the hardware-based control path achieves a measured end-to-end voltage transition latency of 2.3 ms, while the controller adds under 2% static power overhead and under 2% FPGA resource overhead. As a representative case study, VolTune is evaluated on the GTX transceiver supply rail of a Kintex-7 platform. The results show that runtime voltage tuning exposes a bounded operating region with clear trade-offs between energy efficiency and reliability, and achieves up to approximately 29.3% rail-power reduction at 10.0 Gbps when allowing BER up to 10e-6. These results show that FPGA-integrated runtime voltage control can provide practical energy savings with low integration overhead.

翻译：边缘计算平台与大规模数据中心的快速兴起使得能效成为首要设计约束，尤其对于数据密集型及AI驱动的工作负载而言。现场可编程门阵列（FPGA）因其灵活性与能效加速潜力而被日益采用。然而，FPGA的供电电压通常在设计阶段采用保守裕度固定设置，限制了根据运行条件调节功耗的能力。本文提出VolTune——一种开源运行时电压控制架构，通过集成于FPGA的抽象了底层PMBus操作的控制逻辑，实现运行时FPGA供电电压的调谐。VolTune提供基于硬件与软件两种控制路径，使设计者能够在确定性低延迟操作与可编程性之间取得平衡。在所展示的原型中，基于硬件的控制路径测得端到端电压转换延迟为2.3毫秒，而控制器引入的静态功耗开销低于2%，FPGA资源开销亦低于2%。作为代表性案例研究，本文在Kintex-7平台的GTX收发器供电轨上评估了VolTune。结果表明，运行时电压调谐可展现一个具有清晰能效与可靠性权衡的有界工作区域，且在允许误码率（BER）高达10e-6的条件下，于10.0 Gbps速率时实现最高约29.3%的轨电压功耗降低。这些结果证明，FPGA集成式运行时电压控制能够以较低集成开销实现实际节能效果。