Stats

  • Locked Locked
  • Replies 8
  • Subscribers 126
  • Views 18953
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Output busses containing shared nets yielding an error

CADcasualty

This is a simplified description of my issue:

I have a schematic/symbol for a digital block that has 2 bus output pins, each providing control signals to some other target block. I thought I'd make a neat and tidy schematic that involved these two output pins contained some shared nets e.g.:

On the schematic I have:
output pin outx<2:0> to which I connect a bus wire containing the label aa,bb,cc
output pin outy<2:0> to which I connect a bus wire containing the label aa,dd,ee
On the symbol I have two output pins outx<2:0> and outy<2:0>

When I do a check and save I get an error (not a warning) saying the aa terminal is shorted by the two busses. So I guess that message is indeed what is happening, but it is indeed what I want. Why is this an error? The net aa is an output and it'll end up going to two different inputs.

Parents
  • Marc Heise

    Hi,

    setting a label on a wire will set the netname. The pinname will also be taken as a netname for the connected wire. There you get your short from.

    Kind regards,

    Marc

  • CADcasualty
    in reply to Marc Heise

    I think I'm missing the subtle distinctions between labels and names (or more). What I'm trying to do, I believe, seems reasonable - maybe I should have asked what I need to do different to make this work properly...

  • Marc Heise
    in reply to CADcasualty

    Please explain what you try to do ( and maybe why) and I can try to explain how...if possible.  Why should the pin, have a different name than the connected wire?
    If you just want to add some information, you could "Create - Note"  which is more a kind of text label which would not interfere with any design data.

    Our assumption is, that if you  place a label on a net, you probably want to do that to see the name of the net and make it non-generic. Could be the wrong assumption in some cases.

Reply
  • Marc Heise
    in reply to CADcasualty

    Please explain what you try to do ( and maybe why) and I can try to explain how...if possible.  Why should the pin, have a different name than the connected wire?
    If you just want to add some information, you could "Create - Note"  which is more a kind of text label which would not interfere with any design data.

    Our assumption is, that if you  place a label on a net, you probably want to do that to see the name of the net and make it non-generic. Could be the wrong assumption in some cases.

Children
No Data

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.