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  3. How to restrict net renaming to specific cell instances...

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How to restrict net renaming to specific cell instances in layout using SKILL?

AR202509246930
AR202509246930 3 hours ago

I'm using a SKILL procedure to rename power and ground nets (vnn! to vnn, and vpp! to vpp) for instances in my layout. The layout contains three cells: "a", "b", and "c". I want the renaming to apply only to instances of cells "b" and "c", but my current code is also applying changes to "a" unexpectedly.
 

I suspect the condition is not filtering correctly. Could someone help me correct the logic so that the renaming only applies to "b" and "c"?
I'm using cadence virtuoso 23.1 version

Thanks in advance!

Code:

procedure(renamepwrandgrndnets()
let((cv instTerm netObj netName)
cv = geGetEditCellView()

foreach(inst cv~>instances
when(or(equal(inst~>cellName "b")
equal(inst~>cellName "c")
)
printf("Checking instance: %s\n" inst~>cellName)
instTerm = inst~>instTerms
foreach(term instTerm
netObj = term~>net
netName = netObj~>name
printf(" Terminal: %s, Current Net: %s\n" term~>name netName)
cond(
(netName == "vnn!"
printf(" Renaming net '%s' to 'vnn'\n" netName)
dbRenameNet(netObj "vnn")
)
(netName == "vpp!"
printf(" Renaming net '%s' to 'vpp'\n" netName)
dbRenameNet(netObj "vpp")
)
(t
printf(" Net '%s' is not vnn! or vpp!, skipping.\n" netName)
)
)
)
)
)
)
)

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  • AR202509246930
    AR202509246930 6 hours ago

    I'm using a SKILL procedure to rename power and ground nets (vnn! to vnn, and vpp! to vpp) for instances in my layout. The layout contains three cells: "a", "b", and "c". I want the renaming to apply only to instances of cells "b" and "c", but my current code is also applying changes to "a" unexpectedly.
     

    I suspect the condition is not filtering correctly. Could someone help me correct the logic so that the renaming only applies to "b" and "c"?
    I'm using cadence virtuoso 23.1 version

    Thanks in advance!

    Code:

    procedure(renamepwrandgrndnets()
    let((cv instTerm netObj netName)
    cv = geGetEditCellView()

    foreach(inst cv~>instances
    when(or(equal(inst~>cellName "b")
    equal(inst~>cellName "c")
    )
    printf("Checking instance: %s\n" inst~>cellName)
    instTerm = inst~>instTerms
    foreach(term instTerm
    netObj = term~>net
    netName = netObj~>name
    printf(" Terminal: %s, Current Net: %s\n" term~>name netName)
    cond(
    (netName == "vnn!"
    printf(" Renaming net '%s' to 'vnn'\n" netName)
    dbRenameNet(netObj "vnn")
    )
    (netName == "vpp!"
    printf(" Renaming net '%s' to 'vpp'\n" netName)
    dbRenameNet(netObj "vpp")
    )
    (t
    printf(" Net '%s' is not vnn! or vpp!, skipping.\n" netName)
    )
    )
    )
    )
    )
    )
    )

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  • Andrew Beckett
    Andrew Beckett 3 hours ago

    Please do not post the same question in different forums (the forum guidelines ask you not to do this). I joined your two posts together.

    The issue here is almost certainly that your instances a, b and c all have an instTerm connecting to the same net. If you find that net via just b or c, and rename it, it renames it everywhere - the net object is the same. The net is not a different object per instTerm.

    You would need to create a new net with the new name, and then update the instTerm connection to that new net rather than renaming the net itself.

    Andrew

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