Design clocks are the main component for dynamic power computation. If
no clocks are defined, switching activity estimates will be inaccurate, resulting in
inaccurate power estimates. A clock node is identified from timing constraints which
are defined using
create_generated_clock XDC commands.
The Switching tab of the Report Power dialog box displays all the clocks defined in the design.
Make sure all the clocks defined in the design are displayed. Once Report Power runs, the Power Report confirms the percentage of clocks defined in the design when you view the Confidence Level details from the Summary page. This guides you to make sure there is a HIGH confidence level on Clock Activity.
report_clockscommands to get the list of defined clocks. The text report gives the Confidence Level on Clock Activity:
report_power -file power.rpt