report_clock_uncertainity - 2025.1 English - UG835

Vivado Design Suite Tcl Command Reference Guide (UG835)
Document ID
UG835
Release Date
2025-06-16
Version
2025.1 English

Description

This command reports the components of the total clock uncertainty. It can be applied to specific timing paths or between clock pairs and requires an open synthesized or implemented design. The command is applicable only on Versal devices.

Note: By default, the report is written to the Tcl console or STD output. However, the results can also be written to a file or returned as a string if desired.

Arguments

-of_objects <args> - (Optional) Reports the clock uncertainty on the specified timing path objects. It is used with the get_timing_paths command.

Tip: The -of_objects option cannot be used with -from, or -to options which are used to identify clock pairs. The -of_objects option cannot also be used with -setup or -hold.

-from <args> - (Optional) The source clocks of the clock pairs relationship between which the clock uncertainty is analyzed. You can specify clock names or clock objects.

-to <args> - (Optional) The destination clocks of the clock pairs relationship between which the clock uncertainty is analyzed. You can specify clock names or clock objects.

-setup - (Optional) Report the clock uncertainty for setup analysis.

-hold - (Optional) Report the clock uncertainty for hold analysis.

Note: -setup and -hold can be specified together.

-details - (Optional) Provide a detailed breakdown report on the timing paths or clock pairs.

Note: By default, only a summary table is reported.

-no_header - (Optional) Do not write a header to the report.

-file <arg> - (Optional) Write the report into the specified file. Unless you also specify -append, the specified file will be overwritten if it already exists.

Note: If the path is not specified as part of the file name, the file is written into the current working directory, or the directory from which the tool was launched.

-append - (Optional) Append the output of the command to the specified file rather than overwriting it.

Note: The -append option can only be used with the -file option.

-return_string - (Optional) Directs the output to a Tcl string rather than to the standard output. The Tcl string can be captured by a variable definition and parsed or otherwise processed.

Note: This argument cannot be used with the -file option.

Examples

The following example reports the clock uncertainty on the worst setup path: 
report_clock_uncertainty -of_objects [get_timing_paths]

The following example reports the clock uncertainty for the clock domain crossings from a clock specified by name or to another specified as a clock object: 

report_clock_uncertainty -from clk_pin_p -to [get_clocks clk_rx_clk_core]

See Also