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Updating Net Names in Layout XL

FormerMember
FormerMember

I'm having trouble getting the update components and nets function to work as I expect in Layout XL. I'm creating several flavors of a ring oscillator and instead of starting from scratch I copy the layout over from the previous instance and use the update components and nets function to add my new devices. I insert them in the chain where they appear in the schematic but the final node name doesn't update for some reason. For example the output of the first ring oscillator is named osc<11>. All of the subsequent versions are still labeled osc<11> even after doing a Connectivity->Update->Update Components and Nets with the Update Nets and Instance Name Mismatches Only option. This is really just an annoyance as the cell will LVS/DRC clean but I don't understand why this doesn't work. I'm using IC 6.1.7-64b.

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  • FormerMember
    FormerMember

    I found that if I remove the instance(s) that the net in question is connected to and re-instantiate it this issue is fixed. I went ahead and made the changes in each cell but this was a rather inconvenient brute force fix. I think there must be a more elegant solution I'm missing.

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  • FormerMember
    FormerMember

    I found that if I remove the instance(s) that the net in question is connected to and re-instantiate it this issue is fixed. I went ahead and made the changes in each cell but this was a rather inconvenient brute force fix. I think there must be a more elegant solution I'm missing.

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  • Andrew Beckett
    in reply to FormerMember

    I suspect that some of the nets have ended up with a "sticky" net attribute on them and are being preserved after the copy. As you say, VLS XL will be OK, but it would be good to fix.

    The best way to do this is to use Connectivity->Update Binding. Set preserve existing bindings to be on (so that you don't change any existing bindings), and also turn on clear connectivity. This will remove any existing logical connectivity, including any "sticky" nets. That should fix the net names.

    Regards,

    Andrew.

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