Early Power Estimator for Intel® Arria® 10 FPGAs User Guide

ID 683688
Date 9/27/2022
Document Table of Contents

A. Measuring Static Power

Follow these steps to measure static power in your design.

  1. Verify that the device is properly configured and in user mode. (CONF_DONE, NSTATUS, NCONFIG, and TSTPOR values should be high.)
  2. Wait until a stable junction temperature (thermal equilibrium) is reached.
    • Use of a thermally controlled chamber is recommended.
    • You can measure the junction temperature of the FPGA using the on-chip temperature sensing diode (TSD). Refer to your device documentation for details on using the TSD. You could also measure the junction temperature with the TADC, but with reduced accuracy.
    • If a thermally controlled chamber is not available, use temperature feedback from the on-chip TSD or TADC to control a heatsink fan to achieve a desired junction temperature.
    • You can also use a heat gun to achieve a desired temperature; however, this method offers less thermal control.
  3. Keep all inputs constant and do not toggle any I/Os. Do not toggle any clock signals (except for the clock to the TADC, if you are using the TADC to measure temperature.)
  4. Depending on the board design, you can measure static current in one of several ways:
    • Use a regulator with the ability to measure voltage drop across a shunt resistor, and query the power measurement through the power management bus (PMBus)/system management bus (SMBus) interface.
    • If a regulator with PMBus/SMBus support is not available, you can measure the voltage drop across the shunt resistor manually for each power supply and calculate the current from the voltage drop.
    • If you use an external power supply, query the current measurement from the power supply according to the manufacturer's specifications.
  5. If you want to isolate and understand the static power component of your design's total power consumption, take several current measurements across a range of temperatures and record the junction temperature of each measurement. Refer to the junction temperatures to correlate static power measurements with their corresponding total power measurements.
  6. The silicon static power measurements can be compared with the static power estimate from the Power Analyzer report. Alternatively, data for your compiled design can be imported as a .csv file, into the Early Power Estimator for Arria® 10 to obtain static power estimates for comparison. Ensure that you set the power characteristics in the Power Analyzer or Early Power Estimator to Maximum.