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  3. How do I change a signal name that doesn't have a wire

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How do I change a signal name that doesn't have a wire

izucker
izucker over 12 years ago

Hi,

I have a "noConn" (from basic lib) connected directly to an Instance terminal.

There is no wire in between the two objects, meaning that it won't take a "label" for changing the net name.

How can I rename that (internal) signal name in this case? 

Thanks,

Itay

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  • Andrew Beckett
    Andrew Beckett over 12 years ago

    Hi Itay,

    You can't, as far as I know. I think you simply have to drag the noConn a little so that you have a short wire between them, and then you can add a label.

    Regards,

    Andrew.

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  • izucker
    izucker over 12 years ago

    Hi Andrew,

    I think this is the first time that I hear from you that something is impossible... ;-)

    Well, don't you think there should be a way? still, you have a net in your design that you just can't change its name, this isn't seem logical.

    Idea for enhancement?

    Thanks,

    Itay 

     

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  • Andrew Beckett
    Andrew Beckett over 12 years ago

    Hi Itay,

    There's always a first time!

    The challenge is, how would you attach a label to the thing that needs to be named when there is nothing physical to attach to? Possibly you could attach the label to the noConn component, but this would be a bit of a special case. What about the situation where you have two series connected resistors which have overlapping pins - how would you name the net then? You can't attach a label to an instance, because it wouldn't know which pin you wanted it to belong to.

    To some extent, there have to be some semantics associated with how the physical drawing is converted into logical connectivity, and so some rules/limitations apply.

    So if you can think of a good/usable way of naming the net, I can propose it - I just can't think of a way it would be done...

    Regards,

    Andrew.

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  • izucker
    izucker over 12 years ago

    Hi Andrew,

    How about changing the name with some Skill code directly on the internal data structure?

    I couldn't find a way here either...

    Itay

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  • Andrew Beckett
    Andrew Beckett over 12 years ago

    Hi Itay,

    You can do that, but it will get lost as soon as you do a "check" on the schematic again, so it's probably of limited value. That said, we have had some thoughts on having the connectivity being more persistent (only an idea, so I don't want to give details here).

    Andrew.

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  • izucker
    izucker over 12 years ago

    Hi Andrew,

    How would you change the net name in this case with Skill? I couldn't realize how to do that.

    And if the net name was changed and its not the default "net*" anymore, why would the "check" operation will "touch" and change it?

    Thanks,

    Itay

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  • Andrew Beckett
    Andrew Beckett over 12 years ago

    Itay,

    Assuming the net on the "noConn" net was called "net5", this will do it:

    cv=geGetEditCellView()
    old=dbFindNetByName(cv "net5")
    new=dbMakeNet(cv "myNet")
    dbMergeNet(new old)
    dbSetConnCurrent(cv)
    dbSave(cv)

    However, as soon as you do a "check", it will get reset. This is because the physical interconnect drives the connectivity, not the other way around - and any net not set by the schematic checker will get recreated. This is to help ensure that inconsistencies don't appear when connectivity is changed in the schematic - you could have ended up with two things which are still connected to the same net despite there being no physical connection any more (because the wire was deleted), and it would have to somehow know the intent of the user.

    Of course, it's conceivable that we could have it that the connectivity in the database is more persistent, but right now it doesn't work that way.

    Regards,

    Andrew.

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