Follow these steps to measure static power in your design.
- Verify that the device is properly configured and in user mode. (CONF_DONE, NSTATUS, NCONFIG, and INIT_DONE values should be high.)
-
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. Alternatively, you can measure the junction temperature with the Agilex™ 7 Temperature Sensor IP Core, but with reduced accuracy.
- If a thermally controlled chamber is not available, use temperature feedback from the on-chip TSD or Agilex™ 7 Temperature Sensor IP Core to control a heat sink 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.
- Keep all inputs constant and do not toggle any I/Os or any clock signals (except for the clock to the Agilex™ 7 Temperature Sensor IP Core, if you are using the Agilex™ 7 Temperature Sensor IP Core to measure temperature.)
-
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.
- 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.
- The silicon static power measurements can be compared with the static power estimate from the Quartus® Prime Power Analyzer report or the static values shown on the Report tab in the Intel® FPGA Power and Thermal Calculator.