Measurement of High-Temperature Delay Performance Degradation in FPGA Based on Distributed Temperature Sensor Networks

The rapid development of thermal issues in Field Programmable Gate Arrays (FPGAs) has significantly affected the delay performance of these devices, necessitating in-depth study. Ring oscillators, commonly employed as digital temperature sensors in FPGAs, offer a means to sense thermal effects. In this paper, we focus on measuring and studying the delay performance degradation of Xilinx Zynq-7 series FPGAs, based on a 28nm process, when subjected to long-term high temperature working environments. We utilize the internal logic resources of the FPGA to create an embedded ring oscillator, which acts as a temperature sensor. A temperature sensing network is then established to collect frequency data. The degradation of the output frequency of the ring oscillator serves to characterize the delay performance degradation of the FPGA under long-term high temperature operation. After subjecting three target devices to continuous high-temperature degradation experiments for 514 hours, the results highlight that the majority of the ring oscillators exhibit approximately 1% frequency degradation. Moreover, some instances of more pronounced and irreversible degradation were observed. Finally, we briefly analyze the failure mechanism. This experiment provides a theoretical method and experimental support for the study of the thermal characteristics of domestically produced FPGAs.