3 Replies Latest reply on Apr 27, 2011 11:34 AM by tedk

    Measuring the Temperature

    brownrabbit

      Hello All,

       

      I am trying to read the voltage and temperature of the board.

      I found the document 'How to Read the Voltage and Frequency on SCC' and measured the voltage and temperature using the command, 'sccBmc -c status'.

       

      As a result, I got the voltage measured by the 2x2 tile array unit and the temperature of the board like that,

       

      Tertiary supplies:

      OPVR VCC0: 1.0943 V

      OPVR VCC1: 1.0943 V

      OPVR VCC2: 1.0966 V

      OPVR VCC3: 1.0948 V

      OPVR VCC4: 1.0960 V

      OPVR VCC5: 1.0961 V

      OPVR VCC7: 1.0960 V


       

      Temperatures:
      Board: 37 °C
      FPGA: 39 °C

       

       

      I am curious how can I read the temperature of each tile or each core. I also wonder whether I can get the voltage of smaller unit than the 2x2 tile array or not.

       

       

      I am studying the SCC board in early stage yet, so please give me several advice about these questions.

      I look forward to your favorable reply.

       

       

      Thanks,

      Jehun

        • 1. Re: Measuring the Temperature
          jnfurst

          Hi Jehun,

           

          From this post: http://communities.intel.com/message/117770#117770

           

          we see: "There is no ACPI support for SCC, nor a way to get absolute temperatures from the experimental sensors on the SCC without special lab equipment and elaborate procedures to calibrate each sensor since its values vary by individual sensor (across dies and within a die) and voltage.  It is just intended to provide an indication of relative thermal changes."

           

          To roughly calibrate the data...

           

          "Though you can't convert the value to degrees C, you can establish a calibration by putting the processor into a known state and collecting the readings.  Lowest power (and hence lowest temperature after settling) will be with cores in HALT (in RESET will be slightly higher). You can read the CRB register from the MCPC using sccKit to see the value without disturbing the cores, e.g., using the memory widget in sccGui."

           

          Hope that helps.

          • 2. Re: Measuring the Temperature
            tedk

            About those temperature reading you see in the status output ...

             

            The board sensor is a normal diode sitting close to the upper right edge of the J1 socket (below the Intel logo). The measured temperature does not correspond to the real die temperature. There is no correlation to Rock Creek's internal temp sensors.

             

            These temperatures can only be read from the BMC, not from the cores. There's a new FPGA bitstream in the works that will allow access from the cores to all relevant voltages, currents, and both temperature values. This new bitstream is a work in progress (sccKit 1.4.1)  and is not yet available.

             

            Earlier I had said there were no temperature sensors on the Rocky Lake Board, and that was incorrect. When people ask that question they are mostly concerned with getting the temperature that the cores themselves are running at, and there is no sensor for that.  The only facility for that purpose consists of the uncalibrated sensor registers.

            • 3. Re: Measuring the Temperature
              tedk

              You can't set the voltage on an individual tile or core. You can individually set the frequency. You can only set voltage for those voltage domains.