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How can I access/change stdVia enclosures in SKILL?

pilotrp

Hi,

I'm using Virtuoso version ICADV12.3-64b.500.9.  Currelntly, our defualt setup creates metal enclosures that are coincident with the cut shape boundary.  I'd like to modify the enclosures using SKILL to make them DRC clean.  Here's one example:

via~>viaHeader~>??
(db:0x3898833b cellView db:0x3898961a objType "stdViaHeader"
prop nil viaDef db:0x181f01ba viaDefName
"C9CKK1" master db:0x2071ec9a subHeaders nil
vias
(db:0x38987e27) overrideParams nil
)

I looked at the overrideParams in another via where I had manually edited the enclosures.  I saw this:

via2~>viaHeader~>??
(db:0x3898831b cellView db:0x3898961a objType "stdViaHeader"
prop nil viaDef db:0x181f01a7 viaDefName
"M0V0M1" master db:0x3a74ff1a subHeaders nil
vias
(db:0x38987e1c) overrideParams
(("layer1Enc"
(0.025 0.0)
)
("layer2Enc"
(0.008 0.025)
)))

I tried assigning the overrideParams to a similar list with different numerical values, but it errored out.  It also appears that the overrideParams property is nil unless you manually adjust the enclosures.

Can you tell me how I can adjust the via enclosures using SKILL for set of selected vias?

Thanks

  • This worked for stdVia for me

    viaDb~>layer1Enc = list(max(ovlp1 ovlp2) min(ovlp1 ovlp2)))

    viaDb~>layer2Enc = list(min(ovlp1 ovlp2) max(ovlp1 ovlp2))

  • Hi Rob,

    I don't think that you can change the via header override parameters, but as Paul noted, you should be able to change the overrideParams for via objects. If the desired viaHeader already exists, you can just change the via object to point to the desired viaHeader.

    Best regards,
    Lawrence.

  • psill000 said:

    This worked for stdVia for me

    viaDb~>layer1Enc = list(max(ovlp1 ovlp2) min(ovlp1 ovlp2)))

    viaDb~>layer2Enc = list(min(ovlp1 ovlp2) max(ovlp1 ovlp2))

    This worked for me, but I couldn't find any documentation regarding access and/or making changes to other stdVia parameters like this.  Can you point me to some documentation?  For example I took a guess and found viaDb~>cutColumns and viaDb~>cutRows.  Maybe there is access to others, but you need to know the exact parameter names.

    Thanks

  • Rather than hunt it down in the documentation (if it's there, it's well hidden - the via stuff is not terribly well documented), what I tend to do is use the edit properties to change the via, and then use:

    car(geGetSelSet())~>viaHeader~>overrideParams

    to see what the parameters are called and what they've been set to. Then you know the parameter names for operations such as the above.

    Hope that helps (as a pragmatic trick)!

    Andrew

  • Diito what Andrew said. 

    I dont have a list of all the variable for vias symbolics

    Some of the variables for stdVia and customVia are slightly different

    Example

    stdVia

    cutRows

    cutColums

    customVia

    cutRow

    cutColum

    Same variables

    cutWidth cutHeight cutSpacing

    If you can get your Cadence AE is give you an old SKILL small book.

    The book has all the functions in the finder gui. The book is kinda handy for something to thumb through

    Paul

  • Thanks for the help guys. I'll use those tips.

  • You can see the allowed names from a post I made a few years ago which attempted to retrieve the current values from the viaDef or viaHeader override params and then increment them. This isn't strictly necessary (I think I was under mistaken assumption at the time) because you can just do viaInst~>cutWidth (for example) which will retrieve either the override value or the default depending on what's set.

    However, at the very least it serves a useful purpose of telling you all the parameter names for a stdVia:

    https://community.cadence.com/cadence_technology_forums/f/48/p/20735/1305030#1305030

    The parameter names for a customVia may vary, because the point is that it's a pcell (or even a fixed layout) and so you then have some flexibility over whatever the parameters were called when the pcell was implemented.

    Regards,

    Andrew.

  • Hi,

    Can someone tell me how to access/change these parameters on a standard via in SKILL and what the acceptable values are?

    Thanks

  • Hi Rob,

    There are a few functions that I think will help:

    dbGetViaCutLayerControl()
    dbGetViaLayer1Control()
    dbGetViaLayer2Control()
    dbSetViaCutLayerControl()
    dbSetViaLayer1Control()
    dbSetViaLayer2Control()
    dbSetViaColorStateLocked()
    dbSetViaColorStateLayerLocked()

    There are a couple of other functions but I think the above should give you what you need.

    Best regards,

    Lawrence.

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