set_speed_grade - 2021.2 English

Vivado Design Suite Tcl Command Reference Guide (UG835)

Document ID
Release Date
2021.2 English

Set Timing Speed Grade and Temperature Grade


set_speed_grade [‑temperature <arg>] [‑quiet] [‑verbose] [<value>]


String result


Name Description
[-temperature] Temperature grade used for timing analysis (Not available for 7 Series and earlier)
[-quiet] Ignore command errors
[-verbose] Suspend message limits during command execution
[<value>] Speed grade used for timing analysis




Note: After set_speed_grade has been used on a design, it can be used for timing analysis, but it will no longer go through implementation. If you want to run implementation on the design, you should save the design checkpoint and use read_checkpoint -part to implement the design with the new speed grade.

Sets the speed grade used for timing analysis for the target device in the current design.

This command is used to change the speed grade of the target device for timing analysis only, and does not affect other aspects of the design. It must be run on an opened synthesized or implemented design.

Use the set_speed_grade command prior to the report_timing_summary or report_timing command or other timing commands to change the speed grade for analysis. If the timing is valid, then you can use the set_property or set_part command to change the target part for the project to re-synthesize and implement the design.

Tip: For UltraScale devices, you can specify either the temperature or the value to define the speed grade for the part. For 7 series devices, you can only specify the value.

This command returns a transcript of its process, and the speed grade set, or returns an error if it fails.


-temperature - (Optional) Specify the temperature grade for UltraScale devices, used for timing analysis.
Note: This option is not available for 7 series devices, or earlier.
-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.

<value> - (Optional) The speed grade for the target device. Typical values are -1, -1L, -2, or -3. Specifying an incorrect value (e.g. -999) will cause the command to return an error message with a list of valid values for the current part.


The following example sets the speed grade for the device in the current design to -1:
set_speed_grade -1