Connecting and Disconnecting Nets - 2024.1 English

Vivado Design Suite User Guide: Using Tcl Scripting (UG894)

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2024.1 English

The runtime for connecting or disconnecting a collection of objects can vary significantly depending on which command line options are used.

disconnect_net: for disconnecting a large number of nets or pins, when the list of netlist elements is already available as first-class objects, the command line option -pinlist should be used instead of -objects. However, when the netlist elements are only known by name (string), then -objects can be used and results in Vivado automatically converting the strings into first-class objects. The -objects forces the conversion into first-class objects even when first-class objects are passed as argument.

connect_net: for faster runtime, the command line option -dict should be favored as an alternative to -net_object_list but it requires a list of net and pin/port object pairs.

For example:

set myNetA [get_nets netA]      
set myPin1 [get_pins pin1] 
set myPin2 [get_pins pin2] 
set myPin3 [get_pins pin3]  
connect_net -dict [list $myNetA $myPin1 $myNetA $myPin2 $myNetA $myPin3 ]