get_timing_arcs - 2022.1 English

Vivado Design Suite Tcl Command Reference Guide (UG835)

Document ID

UG835

Release Date

2022-05-05

Version

2022.1 English

Get a list of timing arcs

Syntax

get_timing_arcs [‑from <args>] [‑to <args>] [‑filter <arg>]
    [‑of_objects <args>] [‑quiet] [‑verbose]

Returns

List of timing arc objects.

Usage

Name	Description
`[-from]`	List of pin or ports
`[-to]`	List of pin or ports
`[-filter]`	Filter list with expression
`[-of_objects]`	Get timing arcs for these cells
`[-quiet]`	Ignore command errors
`[-verbose]`	Suspend message limits during command execution

Description

Gets a list of timing arcs for the specified objects. You can filter the timing arcs according to specified properties.

Timing arcs are a part of a timing path. A timing arc can be a wire between two pins, or can be the internal path of a logic instance between an input pin and output pin, or clock input and data output pins.

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

-from <args> - (Optional) The starting points of the timing arcs to be returned. Ports, pins, or nets can be specified as startpoints.

-to <args> - (Optional) The endpoints or destination objects of timing arcs to be returned. Ports, pins, or nets can be specified as endpoints.

-filter <args> - (Optional) Filter the results list with the specified expression. The -filter argument filters the list of objects returned by get_timing_arcs based on property values on the timing arcs. You can find the properties on an object with the report_property or list_property commands. In the case of the "timing arc" object, "FROM_PIN", "TO_PIN" and "LIB_CELL" 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:

-filter {IS_PRIMITIVE && !IS_LOC_FIXED}

-of_objects <args> - (Optional) Get timing arcs from the Specified cell objects. If a cell is specified, all cell_arcs of that cell are returned.

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.

Examples

The following example returns the timing arc from the output pin of the specified buffer:

report_property -all [get_timing_arcs -of_objects [get_cells go_IBUF_inst]]

The following example returns the timing arcs of the specified cell:

get_timing_arcs -of_objects [get_cells count_reg[6]]
{count_reg[6]/C --> count_reg[6]/Q [Reg Clk to Q] }
{count_reg[6]/C --> count_reg[6]/D [setup] }
{count_reg[6]/C --> count_reg[6]/D [hold] }
{count_reg[6]/C --> count_reg[6]/CLR [recovery] }
{count_reg[6]/C --> count_reg[6]/CE [hold] }
{count_reg[6]/C --> count_reg[6]/CLR [removal] }
{count_reg[6]/C --> count_reg[6]/CE [setup] }
{count_reg[6]/CLR --> count_reg[6]/Q [Reg Set/Clr] }