all_fanout - 2023.2 English

Vivado Design Suite Tcl Command Reference Guide (UG835)

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2023.2 English

Get a list of pins or cells in fanout of specified sources


all_fanout [‑endpoints_only] [‑flat] [‑only_cells] [‑levels <arg>]
    [‑pin_levels <arg>] [‑trace_arcs <arg>] [‑quiet] [‑verbose] <from>


List of cell or pin objects.


Name Description
[-endpoints_only] Find only the timing endpoints
[-flat] Hierarchy is ignored
[-only_cells] Only cells
[-levels] Maximum number of cell levels to traverse:Value >= 0 Default: 0
[-pin_levels] Maximum number of pin levels to traverse:Value >= 0 Default: 0
[-trace_arcs] Type of network arcs to trace: Values: timing, enabled, all
[-quiet] Ignore command errors
[-verbose] Suspend message limits during command execution
<from> List of source pins, ports, or nets




Returns a list of port, pin, or cell objects in the fanout of the specified sources.

The all_fanout command is scoped to return objects from current level of the hierarchy of the design, either from the top-level or from the level of the current instance. By default the current instance is defined as the top level of the design, but can be changed by using the current_instance command. To return the fanout across all levels of the hierarchy, use the -flat option.


-endpoints_only - (Optional) Find only the timing endpoints. When this option is used, none of the intermediate points in the fan-out network are returned. This option can be used to identify the primary loads of the drivers.

-flat - (Optional) Ignore the hierarchy of the design. By default, only the objects at the same level of hierarchy as the sinks are returned. When using this option, all the objects in the fan-out network of the drivers are considered, regardless of hierarchy.

-only_cells - (Optional) Return only the cell objects in the fanout path of the specified sources.

-levels <value> - (Optional) Maximum number of cell levels to traverse. A value of 1 means to traverse the top-level of the current instance. The default value is 0 and indicates that the tool should traverse all levels in the hierarchy.

-pin_levels <value> - (Optional) Maximum number of pin levels to traverse. The default value is 0.

-trace_arcs <value> - (Optional) Type of network arcs to trace. Valid values are "timing", "enabled", and "all"

-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.

<from> - (Required) The source ports, pins, or nets from which to list the objects in the fanout path.


The following example gets the fanout for all input ports in the design:

all_fanout [all_inputs]

This example gets the fanout for all inputs assigned to I/O Bank 15 in the current design:

all_fanout [filter [all_inputs] {IOBANK == 15}]