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Occurrences reference designator assignment in complex hierarchical design

coronas

Hi all,

consider this AN

when he says:

"Note: As a part will have more than one occurrence in a complex hierarchical design, it is essential that all these occurrences have a unique reference designator in the design. For this, the yellow columns for the parts must have unique reference designator. Therefore, for a complex hierarchical design, the preferred mode of annotation is Occurrence. This ensures that each occurrence gets a unique reference designator."

what  does it means?
when in occurrence annotation mode,
1)sub-circuit reference designators change automatically at each hierarchical block placement/copy action
2)user have to change sub-circuit reference designators at each hierarchical block placement/copy action

I'm asking this because maybe I misunderstand and / or I forgot to set something
if I copy a hierarchical block, the reference designator does not change automatically, and I want that it does.

I had some problems also manually change the reference designator in sub-circuits by double click text to open the display properties dialog, changes made in one occurrence affects other occurrences and other weird things ...
the only way is to change the reference designator manually in property editor view.

i'm using Orcad Capture 16.6-S032.

Thanks

 

 

 

 

 

Parents
  • EngineerPerson

    Hi oldmouldy!

    Yes, I do appreciate the fact that COPYING a block and pasting would require that new occurrence properties be generated for that new occurrence, and that copying those new properties from the instance makes the most sense.  I agree that this is the desired behavior for COPY/paste.

    The bug is that when you CUT and paste a hierarchical block, the occurrence properties are deleted and replaced by new occurrence properties for that block.  In a CUT/paste operation, I am simply trying to move that design component to another location or schematic page.  That block is a part of my design, that correlates to a layout via matching reference designators (or maybe occurrence ID property).  In addition, I may have occurrence properties associated with the parts within that block (ROOM assignments, etc.).  When I CUT/paste the block, I pick up my design, and when I paste it back down, it is DIFFERENT (new ID, ROOM, ref des, etc. properties).  This is 100% a bug, and makes it nearly impossible to reliably maintain a complex hierarchical design.  Please try this.  If your results are different, then I will very happy to know how, but both the AE from Cadence and myself have replicated this issue.  The major danger is that the initial hierarchical design will 'appear' to work fine, and layout and everything will be okay, but if you ever need to CUT/paste any blocks or components, you will lose the occurrence data associated with your parts, and reference designators will be changed and become out of sync with the layout.  For a complex design, this would be a nightmare, and until this bug is fixed, I can conclusively state that Cadence does not support reliable and maintainable hierarchical designs.  I would love to be proven wrong on this, but I don't have high hopes...  I'm greatly anticipating the day that this is fixed, so I can actually use hierarchy in my designs without ending up with an inflexible and/or non-maintainable design.  For now, we are stuck flattening everything...

    ~Jeff

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  • EngineerPerson

    Hi oldmouldy!

    Yes, I do appreciate the fact that COPYING a block and pasting would require that new occurrence properties be generated for that new occurrence, and that copying those new properties from the instance makes the most sense.  I agree that this is the desired behavior for COPY/paste.

    The bug is that when you CUT and paste a hierarchical block, the occurrence properties are deleted and replaced by new occurrence properties for that block.  In a CUT/paste operation, I am simply trying to move that design component to another location or schematic page.  That block is a part of my design, that correlates to a layout via matching reference designators (or maybe occurrence ID property).  In addition, I may have occurrence properties associated with the parts within that block (ROOM assignments, etc.).  When I CUT/paste the block, I pick up my design, and when I paste it back down, it is DIFFERENT (new ID, ROOM, ref des, etc. properties).  This is 100% a bug, and makes it nearly impossible to reliably maintain a complex hierarchical design.  Please try this.  If your results are different, then I will very happy to know how, but both the AE from Cadence and myself have replicated this issue.  The major danger is that the initial hierarchical design will 'appear' to work fine, and layout and everything will be okay, but if you ever need to CUT/paste any blocks or components, you will lose the occurrence data associated with your parts, and reference designators will be changed and become out of sync with the layout.  For a complex design, this would be a nightmare, and until this bug is fixed, I can conclusively state that Cadence does not support reliable and maintainable hierarchical designs.  I would love to be proven wrong on this, but I don't have high hopes...  I'm greatly anticipating the day that this is fixed, so I can actually use hierarchy in my designs without ending up with an inflexible and/or non-maintainable design.  For now, we are stuck flattening everything...

    ~Jeff

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