report_clocks - 2023.2 English

Vivado Design Suite Tcl Command Reference Guide (UG835)

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2023.2 English

Report clocks


report_clocks [‑file <arg>] [‑append] [‑return_string] [‑quiet] [‑verbose]


Name Description
[-file] Filename to output results to. (send output to console if -file is not used)
[-append] Append the results to file, don't overwrite the results file
[-return_string] Return report as string
[-quiet] Ignore command errors
[-verbose] Suspend message limits during command execution
[<clocks>] List of clocks Default: *


Report, Timing


Returns a table showing all the clocks in a design, including propagated clocks, generated and auto-generated clocks, virtual clocks, and inverted clocks in the current synthesized or implemented design. More detailed information about each clock net can be obtained with the report_clock_utilization command.

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.


-file <arg> - (Optional) Write the report into the specified file. The specified file will be overwritten if one already exists, unless -append is also specified.

Note: If the path is not specified as part of the file name, the file will be 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.

-quiet - (Optional) Execute the command quietly, returning no messages from the command. The command also returns TCL_OK regardless of any errors encountered during execution.
Note: Any errors encountered on the command-line, while launching the command, will be returned. Only errors occurring inside the command will be trapped.
-verbose - (Optional) Temporarily override any message limits and return all messages from this command.
Note: Message limits can be defined with the set_msg_config command.

<clocks> - (Optional) The clocks to match against the specified patterns. The default pattern is the wildcard '*' which returns all clocks in the design. More than one pattern can be specified to find multiple clocks based on different search criteria.


The following example returns the name, period, waveform, and sources of the clocks in the current design:

report_clocks -file C:/Data/FPGA_Design/clock_out.txt

The following example reports the clocks in the design with "Clock" in the name:

report_clocks *Clock*