get_bd_cells - 2023.1 English

Vivado Design Suite Tcl Command Reference Guide (UG835)

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2023.1 English

Get a list of block diagram cells


get_bd_cells [‑regexp] [‑hierarchical] [‑filter <arg>] [‑of_objects <args>]
    [‑quiet] [‑verbose] [<patterns>]


List of block diagram cell objects, "" if failed.


Name Description
[-regexp] Patterns are full regular expressions
[-hierarchical] Hierarchical cells included
[-filter] Filter list with expression
[-of_objects] Get cells of these pins or nets
[-quiet] Ignore command errors
[-verbose] Suspend message limits during command execution
[<patterns>] Match engine names against patterns Default: *




Get a list of cells in the current IP integrator subsystem design, or current subsystem instance. IP integrator subsystem cells are either IP cores drawn from the IP integrator catalog, or hierarchical modules created in the subsystem design with the create_bd_cell command.

Note: To improve memory and performance, the get_* commands return a container list of a single type of objects (e.g. cells, nets, pins, or ports). You can add new objects to the list (using lappend for instance), but you can only add the same type of object that is currently in the list. Adding a different type of object, or string, to the list is not permitted and will result in a Tcl error.


-regexp - (Optional) Specifies that the search <patterns> are written as regular expressions. Both search <patterns> and -filter expressions must be written as regular expressions when this argument is used. Xilinx® regular expression Tcl commands are always anchored to the start of the search string. You can add ".*" to the beginning or end of a search string to widen the search to include a substring. See for help with regular expression syntax.
Note: The Tcl built-in command regexp is not anchored, and works as a standard Tcl command. For more information refer to

-hierarchical - (Optional) Get cells from all levels of the IP integrator subsystem design hierarchy, or current instance. Without this argument, the command will only get cells from the top of the design hierarchy. When using -hierarchical, the search pattern should not contain a hierarchy separator because the search pattern is applied at each level of the hierarchy, not to the full hierarchical cell name. For instance, searching for U1/* searches each level of the hierarchy for instances with U1/ in the name. This may not return the intended results.

Note: When used with -regexp, the specified search string is matched against the full hierarchical name, and the U1/* search pattern will work as intended.

-filter <args> - (Optional) Filter the results list with the specified expression. The -filter argument filters the list of objects returned by get_bd_cells based on property values on the block design cells. You can find the properties on an object with the report_property or list_property commands. In the case of the IP integrator cell object, "VLNV", "TYPE" and "LOCATION" are some of the properties that can be used to filter results.

The filter search pattern should be quoted to avoid having to escape special characters. String matching is case-sensitive and is always anchored to the start and to the end of the search string. The wildcard “*” character can be used at the beginning or at the end of a search string to widen the search to include a substring of the property value.
Note: The filter returns an object if a specified property exists on the object, and the specified pattern matches the property value on the object. In the case of the "*" wildcard character, this will match a property with a defined value of "".
For string comparison, the specific operators that can be used in filter expressions are "equal" (==), "not-equal" (!=), "match" (=~), and "not-match" (!~). Numeric comparison operators <, >, <=, and >= can also be used. Multiple filter expressions can be joined by AND and OR (&& and ||). The following gets input pins that do NOT contain the “RESET” substring within their name:
get_pins * -filter {DIRECTION == IN && NAME !~ "*RESET*"}
Boolean (bool) type properties can be directly evaluated in filter expressions as true or not true:
-of_objects <arg> - (Optional) Get the subsystem cells that are connected to the specified pin or net objects, as returned by the get_bd_nets and get_bd_pins, or get_bd_intf_pins commands.
Note: The -of_objects option requires objects to be specified using the get_* commands, such as get_cells or get_pins, rather than specifying objects by name. In addition, -of_objects cannot be used with a search <pattern>.
-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.

<patterns> - (Optional) Match subsystem cells against the specified patterns. The default pattern is the wildcard '*' which gets a list of all cells in the current IP subsystem design. More than one pattern can be specified to find multiple cells based on different search criteria.

Note: You must enclose multiple search patterns in braces {} to present the list as a single element.


The following example gets a list of cells that include the specified IP integrator subsystem pin, and sorts the list to remove duplicate entries:

lsort -unique [get_bd_cells -of_objects [get_bd_pins -hierarchical *aclk*]]
Note: If there are no cells matching the pattern you will get a warning.

The following example gets a list of all cells in all levels of the subsystem design hierarchy, and then filters the list to include only those cells whose name includes the specified text, or hierarchy:

get_bd_cells -hierarchical -filter {NAME=~"/newMod1/*"}