Techniques for Exploring Fine-Grained LUT and Routing Aging on a 28nm FPGA

Understanding how FPGAs age and how to control that aging is crucial for ensuring the reliability and security of FPGAs in critical applications. Due to the proprietary nature of commercial FPGAs, it can be challenging to validate aging models on real silicon, and most previous work has relied on circuit simulations to study the effects of FPGA aging. In this work, we leverage low-level placement and routing APIs provided by RapidWright to create a series of stressor and characterization circuits that allow us to measure the effects of aging on individual LUTs and routing resources in a 28nm FPGA. We demonstrate how these techniques allow fine-grained control of the relative aging of different FPGA resources, even to the point of aging individual paths within a single LUT. Several different aging experiments are demonstrated, and in a cumulative test, we show how different signal and LUT configurations can influence the aging rate by over 2x.