How to get the on-chip temperature of Xilinx Virtex-5 FPGA chip?

Question

I'm trying to do an experiment to see how different on-chip temperatures affect the frequency of ring oscillator. I know that as the temperature increases, the frequency of the ring oscillator also decreases. But I don't know how much it will decrease for every 1 degree Celsius increase. And that's why I want to do the experiment. I'm planning to implement the ring oscillator in a Xilinx Virtex-5 FPGA board (ML501, ML506, or ML510) because those are the only boards that I have. Does anyone know how I can get an accurate reading of the on-chip temperature in Virtex-5?

Answer 1

You're in luck -the V5 was the first generation to support the system monitor block. You can use chipscope to read back the temperature live, or else instantiate the sysmon and read the temperature out from register 0.