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Virtuoso Schematic Bus Connection

RaphaelN

Dear community, 

in a newer Virtuoso version (ICADVM20.1-64b.500.22) the bus system does not work as usual. For example I have a source with 3 instances V1<1:3> and I want to multiply each signal 3 times. In the past (version: ICADVM18.1-64b.500.13) this could be done by labeling the wire as follows <1*3,2*3,3*3>. With the new Virtuoso version I now get three errors:

  • Short between 1*3,2*3,3*3 and V1<1:3>
  • Cannot determine what to tap for <1*3,2*3,3*3>
  • Instance pin width does not match 1*3,2*3,3*3 (3 bits)

Thanks for helping.

Best regards

Raphael

Parents
  • Andrew Beckett

    Raphael,

    This is probably due to a revamp in the schematic extractor to improve performance and robustness - so it changed considerably in ICADVM20.1. However, I would expect it to be compatible; I've managed to reproduce your issue (at least I think I have). I'm just discussing it with R&D and will report back later.

    Andrew

  • Andrew Beckett
    in reply to Andrew Beckett

    Raphael,

    This is due to an oversight - bus tapping without a base name (i.e. with just the indices specified) is less commonly used, and clearly we omitted the situation where multipliers are used for repetitions in that case. I filed CCR 2628282 having discussed it with R&D yesterday.

    If the bus you are tapping from is called V1<1:3> then you can instead use: V1<1*3,2*3,3*3> or simpler still, V1<1:3*3> - that does work - it's OK if the bus name is included, just not if it's not. You can also fully expand it (without the bus name) using <1,1,1,2,2,2,3,3,3> but obviously that's quite verbose.

    Regards,

    Andrew.

Reply
  • Andrew Beckett
    in reply to Andrew Beckett

    Raphael,

    This is due to an oversight - bus tapping without a base name (i.e. with just the indices specified) is less commonly used, and clearly we omitted the situation where multipliers are used for repetitions in that case. I filed CCR 2628282 having discussed it with R&D yesterday.

    If the bus you are tapping from is called V1<1:3> then you can instead use: V1<1*3,2*3,3*3> or simpler still, V1<1:3*3> - that does work - it's OK if the bus name is included, just not if it's not. You can also fully expand it (without the bus name) using <1,1,1,2,2,2,3,3,3> but obviously that's quite verbose.

    Regards,

    Andrew.

Children
  • RaphaelN
    in reply to Andrew Beckett

    Thank you very much! Now it works.

  • Andrew Beckett
    in reply to RaphaelN
    Andrew Beckett said:
    I filed CCR 2628282 having discussed it with R&D yesterday.

    Just to let you know that this has been fixed already. I've tested the fix, and it will be in the next ISR (IC6.1.8-64b.500.25) which is due to be available on 13th May 2022. With the fix, you can name the taps without the prefix as was possible in older versions.

    Regards,

    Andrew

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