Stats

  • Locked Locked
  • Replies 5
  • Subscribers 126
  • Views 15895
  • 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

Assura extraction to ignore certain cells

kawan

 Hello,

I am trying to run an extraction of  a top level cell(say "test_top"). Hoever there is another cell inside ("Cell1") that I do not wish to extract.My expectation is I get get a extracted view called "av_extracted_C" which I can refer to in the hierarchy editor of the top level testbench ("test_top_testbench"). So  "test_top_testbench" has among other things,  the cell  "test_top". In the hierarchy editor I was expecting to use the view "av_extracted_C" for "test_top". I then expect the hierarchy editor to also show "Cell1" and have me select the desired view. Problem is this is not happening.

Assura > Run LVS .. Here I selected "Modify avParameters" to set it up as ?ignoreCell (  cell("Cell1 layout CAL")  ) but that did not work. 

Then I tried  ?preserveCells (  cell("Cell1") excludeCell("Cell1") ) ... but that did not work as well.

 

Any ideas? 

Thanks

zakir

 

  • Hi zakir

    I believe that you are most probably using the Assura-QRC flow. By default, QRC will generate a flat extracted view. You can resolve your problem as follows:

    a. Run Assura LVS with ?preserveCells option for Cell1
    b. Run hierarchical QRC extraction to generate a hierarchical extracted view
    c. Hierarchy editor can now be used on the extracted view

    Please refer to $QRC_HOME/doc/extUser/extUser.pdf for more details on the setup for hierarchical QRC extraction.

    Best regards
    Quek

  •  Quek,

    Thanks!, That was excatly what I ended up doing after a Cadence rep gave me the same directions. I did not post a reply back on thsi as I was still having some issues. The method worked for all but one cell in the hierarchy ... I just cannot explain it.

    But overall, it did what I wanted it to do.

     

    Thanks

    zakir

  • Hi zakir

    Do you mean that QRC is still flattening a particular cell and not preserving it in the extracted view? The problem most probably lies in the LVS. It could already have been expanded in order to achieve LVS match. This means that it has already been flattened during LVS. QRC can only give whatever it receives from LVS, it cannot restore a flattened cell. You might want to check Assura LVS report to confirm this.

    Best regards
    Quek

  •  Yes, I think the pronlem is in the LVS. In the hierarchy editor, that particular cell does not show up. I open the layout view "extracted view" and I see that it has been extracted.That one cell cannot be switched to a schematic or any other view. I did not save the log file , else I can post it here. If I get back to that I will will post the message related to that cell.

  •  I looked up the log file  and here is what I see ...

     

    *WARNING* Binding file Conflict!
        ExpandToParent is requesting to expand Binding cell "RCCAL_INT layout CAL".
        Expansion will be allowed.  Be aware that this expansion may cause LVS matching problems.
     

    *WARNING* '?preserveCells' list: No cell name match for cfmom_2t*
    *WARNING* '?preserveCells' list: No cell name match for cfmom*
    *WARNING* '?preserveCells' list: No cell name match for RCCAL_INT
    *WARNING* '?preserveCells' list: No cell name match for RCCAL_INT

     

    I dod not see any warnings related to any other cell name in the hierarchy except for this one cell called "RCCAL_INT"

    Almost feels like a typo in the hrcx list but it it not.

    RCCAL_DIG_CTRL
    + netlist=none
    LDO_CAPLESS_1V2
    + netlist=none
    RCCAL_VREF_GEN
    + netlist=none
    RCCAL_INT
    + netlist=none
    RCCAL_COMP_TOP
    + netlist=none
    RCCAL_TM_CTRL
    + netlist=none
    RCAL_RTRIM
    + netlist=none
    RCCAL_TMUX
    + netlist=none
    RCCAL_IBIAS_GEN
    + netlist=none
     

     

     

     

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.