create_fromto

create_fromto
-fromSet d_setObj 
-toSet d_setObj 
[ -allow_duplicate [ true | false ] ] 
[ -constraintGroup s_groupName ] 
[ -fromLayer s_layerName ] 
[ -fromPoint { f_x f_y } ] 
[ -incremental [ true | false ] ] 
[ -must_connect [ true | false ] ] 
[ -toLayer s_layerName ] 
[ -toPoint { f_x f_y } ]

Description

Creates a route guide between terminals. A constraint group can be assigned to the guide to specify constraints for routing, which will have precedence over constraints for the net, global net default, design and foundry rules. For terminals with more than one pin shape, only one pin will be connected by default, but the choice of pins can be restricted to a specific layer.

By default, if a net has existing guides and/or route segments, create_fromto will not create additional guides. When -incremental is true, guides can be added to a net that has existing guides and/or route segments. However, duplicate guides between a driver and sink will not be added.

Arguments

-allow_duplicate [ true | false ]
	When set to true, duplicate guides can be created between a “from“ point and a “to“ point. When set to false, only one guide is created between each “from“ and “to“. Default: false
-constraintGroup s_groupName
	Assigns a constraint group to the new guides. When routed, constraints in the constraint group will be honored.
-fromLayer s_layerName
	Considers only “from” pins on the given layer.
-fromPoint { f_x f_y }	Specifies the “from“ point as an x and y coordinate.
-fromSet d_setObj	Set containing the “from” terminal.
-incremental [ true | false ]
	Specifies whether guides can be added to a net that has existing guides and/or route segments. When set to false, guides cannot be added to a net with existing guides and/or route segments. Default: false
-must_connect [ true | false ]
	When set to true, treats pins of the same terminal as must-connect by creating a guide from the driver directly to each pin on the terminal. When set to false, pins of the same terminal are treated as weak-connect and only one guide is created from the driver to the pins. Default: false
-toLayer s_layerName	Considers only “to” pins on the given layer.
-toPoint { f_x f_y }	Specifies the “to“ point as an x and y coordinate.
-toSet d_setObj	Set containing the “to” terminal.

Examples

Example 1—Create a guide between two terminals

The following example creates a guide between terminals t1 and t3.

create_fromto -fromSet [find_terminal -name t1] -toSet [find_terminal -name t3]

Example 2—Route a guide between two terminals

In the following example, a guide is routed between two terminals of a net. First, a guide is created between the terminals, then the routing flow is run on the net without creating additional guides in the global route step.

# Specify the net to route
set myNet [find_net -name AVCC1]

# Create a guide between two terminals
create_fromto -fromSet [find_inst_term -instance_name u_40 -name VDD3] -toSet [find_inst_term -instance_name u_f27 -name VDD_3P3V]

# Run the routing flow
global_route -set $myNet -create_guides false -mode full
croute -set $myNet
detail_route -set $myNet

Related Topics

Specialty Route Commands

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