resize_net_bus - 2022.1 English

Vivado Design Suite Tcl Command Reference Guide (UG835)

Document ID
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2022.1 English

Resize net bus in the current design


resize_net_bus [‑from <arg>] [‑to <arg>] [‑quiet] [‑verbose]


Name Description
[-from] New starting bus index
[-to] New ending bus index
[-quiet] Ignore command errors
[-verbose] Suspend message limits during command execution
<net_bus_name> Name of the net bus to resize




Resize an existing bus net, to grow the bus, shrink the bus, or renumber the current range of indexes. You can only do a single grow, shrink, or renumber operation with each command.
  • You can grow the bus by indicating a new range of indexes outside the current range of indexes. Growing the bus leaves existing bits connected as they currently are.
  • You can shrink the bus by indicating a new range of indexes inside the current range of indexes. Shrinking the bus, eliminates connections to removed bits, but leaves the remaining bits connected as they currently are.
  • You can renumber the current bus indexes by providing a new range of indexes with the same width as the current range. Renumbering bits changes bus bit numeric identifiers, but doesn't otherwise change connections.
Netlist editing changes the in-memory view of the netlist in the current design. It does not change the files in the source fileset, or change the persistent design on the disk. Changes made to the netlist may be saved to a design checkpoint using the write_checkpoint command, or may be exported to a netlist file such as Verilog, VHDL, or EDIF, using the appropriate write_* command.
Note: Netlist editing is not allowed on the elaborated RTL design.

This command returns nothing if successful, and returns an error if it fails.


-from <arg> - (Optional) The new starting index of the specified bus net.

-to <arg> - (Optional) The new ending index of the specified bus.

-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.

<net_bus_name> - (Required) The names of an existing bus net.


The following example creates a new 24-bit bus, then renumbers the bus indexes to include negative indexes, and then resizes the bus to shrink it to an 8-bit bus:

create_net tempBus -from 23 -to 0
resize_net_bus tempBus -from -12 -to 11
resize_net_bus tempBus -from 0 -to 7