stop_vcd - 2023.2 English

Vivado Design Suite Tcl Command Reference Guide (UG835)

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2023.2 English

Stop capturing VCD output (equivalent of $dumpoff verilog system task). The start_vcd TCL command can be used to resume capturing VCD


stop_vcd [‑ports] [‑file <arg>] [‑quiet] [‑verbose]


Name Description
[-ports] Control extended vcd dump file.
[-file] Specify the file where ports have to stop dumping . Default: Stops all dumpport files
[-quiet] Ignore command errors
[-verbose] Suspend message limits during command execution



Stop writing the simulation values to the current Value Change Dump (VCD) file. This suspends the output of simulation information to the file until the process is resumed using the start_vcd command.

This Tcl command models the behavior of the Verilog $dumpoff system task.

Important: You must execute the open_vcd command before using the stop_vcd command.

Nothing is returned by the command.


-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 stops writing simulation values to the current VCD file: