get_nodes - 2021.1 English

Vivado Design Suite Tcl Command Reference Guide (UG835)

Document ID

UG835

Release Date

2021-06-16

Version

2021.1 English

Get a list of nodes in the device.

Syntax

get_nodes [‑of_objects <args>] [‑regexp] [‑nocase] [‑filter <arg>]
    [‑uphill] [‑downhill] [‑flyover] [‑from <args>] [‑to <args>] [‑quiet]
    [‑verbose] [<patterns>]

Returns

Nodes

Usage

Name	Description
`[-of_objects]`	Get 'node' objects of these types: 'net tile node bel_pin site_pin wire pip speed_model'.
`[-regexp]`	Patterns are full regular expressions
`[-nocase]`	Perform case-insensitive matching. (valid only when -regexp specified)
`[-filter]`	Filter list with expression
`[-uphill]`	Get the nodes uphill (driver) from the site_pin, pip, node or tile(s) provided in the -of_objects.
`[-downhill]`	Get the nodes downhill (loads) from the site_pin, pip, node or tile(s) provided in the -of_objects.
`[-flyover]`	Get the nodes that fly over the given tile(s).
`[-from]`	-from <pip/site pin> Return the nodes beginning at this pip or site pin. May be used in combination with uphill. Default is downhill. -all is implied.
`[-to]`	-to <pip/site pin> Return the nodes ending at this wire or site pin. May be used in combination with uphill. Default is downhill. -all is implied.
`[-quiet]`	Ignore command errors
`[-verbose]`	Suspend message limits during command execution
`[<patterns>]`	Match the 'node' objects against patterns. Default: *

Description

Returns a list of nodes on the device that match a specified search pattern in an open design.

The default command gets a list of all nodes on the device.

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.

Arguments

-of_objects <args> - (Optional) Return the nodes of the specified nets, tiles, nodes, bel_pins, site_pins, wires, speed_model or pip objects.

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>.

-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 http://perldoc.perl.org/perlre.html 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 http://www.tcl.tk/man/tcl8.5/TclCmd/regexp.htm.

-nocase - (Optional) Perform case-insensitive matching when a pattern has been specified. This argument applies to the use of -regexp only.

-filter <args> - Filter the results list with the specified expression. The -filter argument filters the list of objects returned by get_nodes based on property values on the nodes. You can find the properties on an object with the report_property or list_property commands. Any property/value pair can be used as a filter. In the case of the node object, "IS_INPUT_PIN", "IS_BEL_PIN" and "NUM_WIRES" 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 that may be found in net, pin, or cell names, or other properties. 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:

-filter {IS_PRIMITIVE && !IS_LOC_FIXED}

-uphill - (Optional) Return the nodes uphill of objects specified by the -of_objects option. Uphill nodes precede the specified object in the logic network.

-downhill - (Optional) Return the nodes downhill of objects specified by the -of_objects option. Downhill nodes follow the specified object in the logic network.

-flyover - (Optional) Return the nodes that pass through (or flyover) the specified tiles.

-from <args> - (Optional) Defines the starting points of the nodes to get from site_pin or pip objects. This option can be combined with -uphill. The default is to return nodes downhill of a start point. By default, all nodes will be returned.

-to <args> - (Optional) Defines the ending points of the nodes to get from site_pin or pip objects. This option can be combined with -uphill. The default is to return nodes downhill of a start point to the specified end point. By default, all nodes will be returned.

-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) Return nodes matching the specified search patterns. The default pattern is the wildcard '*' which gets a list of all nodes on the device. More than one search pattern can be specified to find nodes based on different search criteria.

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

Examples

The following example returns the nodes associated with the specified tile:

get_nodes -of_objects [get_tiles CLBLM_R_X11Y158]

The following example returns the nodes downhill from the specified node:

get_nodes -downhill -of_objects [get_nodes LIOB33_SING_X0Y199/IOB_PADOUT0]