A Reliable and Efficient Online Solution for Adaptive Voltage and Frequency Scaling on FPGAs

Adaptive voltage and frequency scaling (AVFS) technology adjusts the supply voltage and clock frequency based on the actual operating conditions of the circuit. It can significantly improve performance or reduce the power consumption of the device. Existing online field-programmable gate array (FPGA) AVFS solutions have relatively low adjustment efficiency. Many existing solutions rely on offline steps, which do not consider the runtime operating conditions. This article proposes a complete FPGA AVFS solution, which includes a versatile self-checking timing monitor (SCTM) with small resource overhead, efficient AVFS algorithms without any offline steps, and user-friendly comprehensive automation software. Compared with existing online solutions, the proposed solution improves scaling efficiency by reducing the number of configuration times for the clock generation unit. The effectiveness of the solution is evaluated by a set of pubic benchmarks. Experimental results indicate that it can set an appropriate voltage-frequency operating point for the application circuit within dozens of milliseconds. For power-oriented adjustment, the proposed solution can save power ranging from 33.93% to 43.46%, while keeping the frequency not slower than the one reported by the static timing analysis (STA). For performance-oriented adjustment, it can achieve a performance improvement ranging from 60.26% to 101.90% at the nominal voltage.