report_disable_timing - 2024.1 English

Vivado Design Suite Tcl Command Reference Guide (UG835)

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2024.1 English

Report disabled timing arcs


report_disable_timing [‑user_disabled] [‑column_style <arg>] [‑file <arg>]
    [‑append] [‑cells <args>] [‑return_string] [‑quiet] [‑verbose]


Name Description
[-user_disabled] Report only user disabled arcs
[-column_style] Style for path report columns: Values: variable_width, anchor_left Default: variable_width
[-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
[-cells] Run report_disable_timing on the specified cell(s)
[-return_string] Return report as string
[-quiet] Ignore command errors
[-verbose] Suspend message limits during command execution


Report, Timing


Displays a report of timing paths that will be excluded from timing analysis in the current synthesized or implemented design.

The format of the report is organized into columns for "Cell or Port" to define the object associated with the timing path, "From" and "To" to define the timing path, the condition, and the reason for excluding the path from timing. The various reasons for exclusion are as follows:

  • constraint - set_disable_timing constraint is specified
  • constant - Logic constant
  • loop - Breaks a logic loop
  • bidirect instance path - Feedback path through bidirectional instances
  • bidirect net path - Feedback path on nets with bidirectional pins
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.


-user_disabled - (Optional) Report only the timing arcs that have been disabled by the user with the set_disable_timing command.

-column_style [ variable_width | anchor_left ] - (Optional) Specifies the alignment of the columns in the report. The default is variable_width when the option is not specified.

-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.

-cells <arg> - (Option) The details of the report will be based on the specified cells rather than the whole design.

-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.
-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.


The following example reports all timing paths that will not be included in timing analysis:


The following example outputs the disable timing report as a string, stores it in a variable, and then puts it to the display:

set bad_time [report_disable_timing -return_string]
puts $bad_time