using matching netlists to identify matching schematics

Discussion in 'Programmer's Corner' started by nmsweeney, Mar 8, 2012.

  1. nmsweeney

    Thread Starter New Member

    Mar 8, 2012
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    0
    Hi,

    I am a newbie, so thanks in advance for your patience.

    I need a procedure to match netlists (plain text format). If a newly created netlist matches an existing one, their circuit diagrams should also match or come fairly close.

    Has anyone done something like this? We are using a program called CIRCAD to create schematics and their netlists.

    Thanks again,

    Nina
     
  2. John P

    AAC Fanatic!

    Oct 14, 2008
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    This might depend on how the netlist file is created, but if the traces have consistent names in different files, but the order of listing is different, you could bring a netlist into Excel (as text, delimited somehow) and use the sort-data feature to alphabetize the traces. Multiple files treated this way would then look more similar than they did at first. That might do it.

    But if the parts and nets all have different names in the various files, it's more difficult. Could Excel filter out how many nodes each net had, and how many pin 1's of various IC's, and pin 2's and so forth attached to that net, and thus create a "fingerprint" for a trace regardless of its name and the designation of the parts, and then an overall fingerprint for the entire file?
     
  3. nmsweeney

    Thread Starter New Member

    Mar 8, 2012
    2
    0
    John,

    You put your finger on the part of the problem we need to solve. Two functionally equivalent circuit boards may have components with different labels (for example, one engineer's Decoder 1 might be another engineer's Decoder 2) but which are connected in the same way to other types of components.

    I was wondering if someone out there had taken this on already.

    Thanks,

    Nina
     
  4. John P

    AAC Fanatic!

    Oct 14, 2008
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    Maybe the easiest way to solve this is simply to correlate the parts lists of the designs. If they accomplish the same functions, they should use pretty much the same inventory of parts. Doing it this way means you don't have to be concerned with the layout, just the components.
     
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  5. nigelwright7557

    Senior Member

    May 10, 2008
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    This is quite complicated as sometimes a net can touch the same point twice if "foldback" is used.
    Also the net might be in a different order in the schematics yet still be the same.
    If a schematic then nets could be split too.

    I have actually done this in my "Integrity check" in pcbcad40 and it isnt a simple process.
     
    Last edited: Mar 21, 2012
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