viaStackingAllowed

Specifies whether you can stack the two cut layers. This constraint should be specified for cut layers only. A via is considered to be in a stack with another via if the cut of one via overlaps any part of the cut of the other via.

This constraint is symmetric, implying that when via stacking is allowed for via1 and via2, it is also allowed for via2 and via1.

viaStackingAllowed Quick Reference

Constraint Type	Layer pair
Value Types	`BoolValue`
Database Types	Design, Technology
Scope	design, foundry
Category	Via Construction

Value Type

The viaStackingAllowed constraint has a BoolValue. When set to true, via stacking is allowed for the two cut layers. When set to false, via stacking is not allowed for the two layers.

Examples

This example permits stacking of cutLayer1 and cutLayer2, as shown in the following figure.

Format	Example
Tcl	set_layerpair_constraint -layer1 cutLayer1 -layer2 cutLayer2 \ -constraint viaStackingAllowed -BoolValue true
Virtuoso	spacings ( (stackable "cutLayer1" "cutLayer2" t ) )

viaStackingAllowed Example

Virtuoso Space-based Router Constraint Reference
Product Version IC23.1, June 2023