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Problem with tutorial - Repeated part IDs in Hierarchical tutorial

scotty2541

I do not even know if this is the correct forum to ask this...  If not, please steer me to the correct place.

I am going through the tutorial, trying to learn this. In the 'Create hierarchical design' section, I create the Hieracchial block for the half adder.  Then I copy/paste it to create a second one. Just like the tutorial says.

The problem is that BOTH of the blocks are using the same 'Ux' Numbers.  So the first AND gate in HALFADD_A1 is U1A, and the first AND gate in the *other* block uses the same one!   When I open one of the designs and change it, it changes in the other one too!

 The 'Design Tools Check...'  action gives me a big list of
"Same Pin Number connected to  more than one net. HALFADD_B1/U2C/5 Nets:...". 
Which is expected, since the design is reusing the same gates in both blocks.

 How does someone convince the OrCAD Capture program that components in blocks need to have different numbers?

 Any help I can get with this, or any (more useful) tutorial that can get a complete novice started would be appreciated!

  • oldmouldy

    What you have would be correct since you are building a complex hierarchical design which has one schematic used multiple times so the annotation needs to be updated to use "occurrence" properties, rather than "instance" properties.

    Select the DSN file entry in the Project Window and use Tools>Annotate to open the Annotation dialog, set the option to "Reset to ?" and OK to clear the annotation, then use Tools>Annotate again with "Incremental Annotation" to annotate the design.

    A complete novice might be better off avoiding complex hierarchical, and any hierarchical, designs entirely. 

  • scotty2541

    oldmouldy said:

    What you have would be correct since you are building a complex hierarchical design which has one schematic used multiple times so the annotation needs to be updated to use "occurrence" properties, rather than "instance" properties.

    Select the DSN file entry in the Project Window and use Tools>Annotate to open the Annotation dialog, set the option to "Reset to ?" and OK to clear the annotation, then use Tools>Annotate again with "Incremental Annotation" to annotate the design.

    A complete novice might be better off avoiding complex hierarchical, and any hierarchical, designs entirely. 

    Yes, that took care of it.  After doing to twice, the second time setting 'update occurances'.  Thanks for your help.

    The tutorial clearly says you don't need to annotate, because it's being done automatically.  But if it was turned off, here it what you do....  It's doesn't say the project is broken because it was being done automatically.

    It also says to check the radio button for update occurances rather than update instances, and says to ignore the warning box that pops up.  But doesn't explain the differences.

    After added several more grey hairs dealing with this, I agree that a hiearchical design should be avoided by a novice.  But the Readme says "For an overview of the basic process for designing a PCB using OrCAD 16.0, please refer to the OrCAD Flow Guide. "  So I did.  Besides this tutorial, there is no other good source I can find. :-(

    Watch for my next question on using PSpice... :-)

    -Scotty

     

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