Performing Power Analysis with the PowerPlay Power Analyzer

The process of estimating power consumption with the PowerPlay Power Analyzer consists of three parts: specifying sources of input data, specifying operating conditions, and running the PowerPlay Power Analyzer.

You must provide the PowerPlay Power Analyzer with three types of information: a compiled user design, signal activities in the design, and the operating conditions under which the device is used. The quality of the resulting power consumption and thermal dissipation estimates depends on the quality of this information, so you should provide the most accurate data possible.

Note: You can specify data from more than one source. Perform as many of the following steps as are applicable to your situation.

If you want to specify signal activity data with the Assignment Editor, follow these steps:
1. Use the Node Finder to add the nodes for which you want to assign signal activity data to the Assignment Editor.
2. For each node or entity listed in the Assignment Editor spreadsheet, follow these steps:
1. Select an assignment name from those available in the Assignment Name column.
2. Type or select the required value in the Value column.
3. Enable the assignment by selecting Yes in the Enabled column.

If you want to create a Value Change Dump File (.vcd) for a third party simulator, follow these steps:
1. In the Quartus II software, on the Assignments menu, click Settings. The Settings dialog box appears.
2. In the Category list, under EDA Tool Settings, click Simulation.
3. In the Tool name list, select VCS and turn on the Generate Value Change Dump (VCD) file script option.
4. To generate the .vcd,on the Processing menu, click Start Compilation.

If you want the PowerPlay Power Analyzer to initialize toggle rates and static probabilities from input files, follow these steps:

If you want to create a Signal Activity File (.saf) containing the signal activities used during power analysis, on the PowerPlay Power Analyzer Settings page, turn on Write out signal activities used during power analysis and specify the name of the .saf.
If you want to create a Signal Activities Report containing the signal activities used during power analysis, on the PowerPlay Power Analyzer Settings page, turn on Write signal activities to report file.
If you want to create a Power Dissipation by Block Report containing power dissipation data for each block in the design, on the PowerPlay Power Analyzer Settings page, turn on Write power dissipation by block to report file.

To specify default toggle rates for signals not specified in an input file or assignment, follow these steps:

Click OK.

Operating conditions settings are available for Device dialog box.

To specify the general power characteristics of the device family in use, on the Operating Settings and Conditions page, in the Device power characteristics list, select Typical or Maximum.

Important: Power analyses performed with the Device power characteristics option set to Typical are based on the average power consumed by typical silicon at nominal operating conditions. For FPGA board power supply design, set the Device power characteristics option to Maximum to obtain worst-case values.

If the device selected in the Device dialog box has a hard processor system (HPS), in the HPS Power Calculator dialog box, turn on Enable HPS and specify the operating frequency of the HPS.
If the device selected in the Device dialog box has configurable power rails, on the Voltage page, specify the power rail voltages.
If you want to specify a specific junction temperature to use during power analysis, on the Temperature page, under Junction temperature and cooling solution settings for PowerPlay power analysis, select Specify junction temperature and type a value in degrees Celsius. The junction temperature you specify must be within the Junction temperature range displayed on the Temperature page.
If you want the PowerPlay Power Analyzer to calculate a junction temperature based on information you provide, follow these steps:
1. Under Junction temperature and cooling solution settings for PowerPlay power analysis, select Auto compute junction temperature using cooling solution.
2. In the Ambient temperature box, type a value in degrees Celsius, representing the expected ambient temperature of the environment in which the device operates.
3. To set the device cooling solution, perform one of the following:
  To direct the PowerPlay Power Analyzer to assume a preset cooling solution perform one of the following:
  
  Under Thermal resistances, select a predefined cooling solution from the Use cooling solution list.
  
  or
  
  To specify a custom cooling solution, follow these steps:
  1. Under Thermal resistances, select Custom.
  2. In the Case-to-heat sink box, specify the case-to-heat sink thermal resistance, in degrees Celsius per watt.
  3. In the Heat sink-to-ambient box, specify the heat sink-to-ambient thermal resistance, in degrees Celsius per watt.
If, in step 5c, you selected a predefined cooling solution with a heat sink or specified a custom cooling solution, under Board thermal modeling, select a board thermal model from the list.
If, in step 5, you specified a Custom or Typical board thermal model, specify a value for Board temperature in degrees Celsius.
If, in step 5, you specified a Custom board thermal model, specify a value for Junction-to-board thermal resistance, in degrees Celsius per watt.
Click OK.