How to get via Constraint

conGrp = cstFindConstraintGroupIn(techId "virtuosoDefaultSetup")
viaGetViaOptions(conGrp)~>??

Is this the correct method?

Are there more via constraints using a different constraint than "virtuosoDefaultSetup"?

Where do I find the other constraints?

Paul

Paul,

A few things:

• virtuosoDefaultSetup is not a constraint - it's a constraint group (in other words it's a container for multiple constraints).
• The currently active constraint group for vias can be seen in Options->Editor in the layout editor - and can be retrieved with cstGetDefaultConstraintGroupName(cvId "Via")
• The viaGetViaOptions function is for use with the other via functions (e.g. viaGenerateViasAtPoint, viaRecomputeVias etc) - not for lxComputeViaParams (an older function rather than the more general and powerful via functions which are a more recent addition).
• Unfortunately there doesn't seem to be a public API to get all the constraint group names, but at least those from the technology file can be found using techId~>constraintGroups~>name

Regards,

Andrew.

Hi Andrew,

I have some related question about viaGenerateVias* functions. It seems that it can only handle top level. How do I use them to fill via in the lower level of a cell.

Thanks,

Yanhong

Hi Yanhong,

Your question is not that clear - viaGenerateViasAtPoint (as an example) can only generate vias in the cellView you give it, although it can identify the overlapping regions in lower levels of hierarchy by using the ?startLevel and ?stopLevel arguments. I'm not sure how you'd expect it to generate the vias in a lower level cell based on higher level geometries because presumably you could have other occurrences of that cell for which the vias wouldn't make sense. 

So maybe I've misunderstood what you're asking?

Regards,

Andrew.

Andrew, 

I mean fill via in the overlapping regions in lower levels of hierarchy. I tried to use  ?startLevel and ?stopLevel argument as you suggested, and it worked. 

Thanks a lot,

Yanhong