Temperature and on-chip crosstalk measurement using ring oscillators in FPGA

Temperature management and signal integrity are two highly relevant challenges for nano scale CMOS devices. As temperature of integrated circuits affects the frequency of defect mechanisms´ occurrence and consequently influences reliability, temperature monitoring is inevitable. To provide the necessary thermal sensors, different techniques are available. One is to use the temperature dependent speed of logic devices and perform a time to digital conversion. In this work, this approach is evaluated for the use in FPGAs. Furthermore, problems regarding signal integrity affect the reliability of highly integrated circuits. Therefore, we discuss the possibilities of crosstalk effects in FPGA and demonstrate a method for time to digital conversion in order to measure the impact of coupling capacitances in the interconnection structure of FPGAs. The main contribution of the introduced method is to enable simple post-production investigations for signal integrity of programmable devices.