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AbstractBlockageCoverLayers on not flatten memory instance

samung
Hello,

I would like to understand better the AbstractBlockageCoverLayers function in Abstract generator Tool, step Abstract (Blockage).

absSetBinOption("Core" "AbstractBlockageCoverLayers" "M1 M2X M3X ")


Actually, I would like to define some blockages, let's say I have my "memory instance" layout up to MX, so it means the vdd/vss are in MX, but there are some layers from M1 to MX-1 in the "memory instance". 
The access pins are located at the edges of the "memory instance".

I would like to generate an ABSTRACT view as follow : "cover blockage" for M1 to MX-1 and "Detailed Blocakge" for MX.


When I generate the ABSTRACT view, I just have : the MX layer, I don't have the other Metal cover layers.

My input : the "memory instance" layout up to MX (meaning that with Virtuoso Layout Eiditng, i see all the metal layers), but the "memory instance" is not flatten (meaning that it is made of different cells : array_blxxx cell, master control cell ...).


So, do I have to do a flatten of all the "memory instance" cells to be able to generate the different metal cover layers in the ABSTRACT view or is there another way ?

Thanks !!

P.
 
PS :
 
tool version : IC6.1.5-64b.500.9
xxx/cadence_amsams2010.2c_mmsim/lnx/tools/dfII/bin/abstract 

  •  Hi,

    You do not need to flatten any subcells.

    This sounds like a similar problem you already posted. (subcells not readable) which I already answered.

    But, I believe the tool should still be able to generate cover blockages at the top level even if you  have problems reading the subcells.

    Do you have a prBoundary for your top-level cell?

    If not, you can create it with create->prObjects->prBoundary in Virtuoso.

     

    The tool should then create cover obstructions correctly from the prBoundary object dimensions.

     

    Colin

  •  I have just noticed another point:

    Your definition for blockages are for cells of type "core"

    If your memory is not in the "core" bin it will not work.

    (You probably need to make the definitions in the "block" section rather than "core")

     

    However, to move  the memory to "core" you need to select it and click cells->move and select the "core" category.

     

    Colin

  • Hello Colin,

    you were right regarding the "Block" attribute. 

    With this setting in the abstract.record :
    absSetBinOption("Block" "AbstractBlockageDetailedLayers" "M3X ")
    absSetBinOption("Block" "AbstractBlockageCoverLayers" "M1 M2X")

    I have my LEF file generated from Abstarct generator Tool with :
    absSetOption("ExportLEFFile" "test2.lef")
    absExportLEF()
     
    OBS
        LAYER M1 ;
          RECT 0 0 34 19.1 ;
        LAYER M2X ;
          RECT 0 0 34 19.1 ;
        LAYER M3X ;
          RECT 0 184.625 34 189.125 ;
          RECT 0 179.425 34 183.925 ;
          ...
          RECT 0 29.005 34 33.505 ;
          RECT 0 22.505 34 27.005 ;
          RECT 0 17.305 34 21.805 ;
      END
     
    NB : of course, i have changed the sizes of the layers in the copy-paste here, to write this request here.
     
    So I have what I want in the LEF, regarding teh OBSTRUCTION with the cover layers. However, the ABSTRACT view, just contain the last metal layer for the power/ground and does'nt contain the cover layers. It has also the PR boundary (this one was already in the input layout view, so I didn't regenerate it). 
     
    Would you know why the 2 views : ABSTRACT and LEF are not consistent regarding the cover layers ?
     
    Thanks a lot !
     
    P. 

  •  Hi,

    The abstract view must have all the information, otherwise you would not have got the correct results in the LEF.

    I cannot explain why the cover blockages are not there.

    But, just to check if they really are there, or not.......

    Check that the colors/stipples for the M1, M2X blockages  have some useful color patterns. (It may be just a visual thing)

    Or, click File->summary and check the statistics:

     

    You should see something like this:

     ***********************************************************************************************************

                                   Blockage Object Statistics
    ***********************************************************************************************************


    Total number of Blockage Objects    :     7

        Placement Area Blockage Objects    :     0

        Placement Area Halo Objects    :     0

        Layer Blockage Objects        :     7

        Layer Halo Blockage Objects    :     0

        Consolidated Layer and Layer Halo Blockage Object details

        --------------------------------------------------------------------------
        Layer      Routing  Fill  Slot  Pin  Feedthru  Screen  Total
        --------------------------------------------------------------------------
        Metal1           7     0     0    0         0       0      7
        --------------------------------------------------------------------------
        Total            7     0     0    0         0       0      7
        --------------------------------------------------------------------------

     

     

    If this is empty, I have no further ideas what can be wrong.

    Then I would suggest you contact customer support.

     

    Colin

  • Yes, I have the blockage layers identified in the ABSTRACT view (File->Summary) :

     ***********************************************************************************************************

     

                                   Blockage Object Statistics

    ***********************************************************************************************************

     

     

    Total number of Blockage Objects :    16

     

    Placement Area Blockage Objects :     0

     

    Placement Area Halo Objects :     0

     

    Layer Blockage Objects :    16

     

    Layer Halo Blockage Objects :     0

     

    Consolidated Layer and Layer Halo Blockage Object details 

     

    --------------------------------------------------------------------------

    Layer      Routing  Fill  Slot  Pin  Feedthru  Screen  Total

    --------------------------------------------------------------------------

    M1               1     0     0    0         0       0      1 

    M2X              1     0     0    0         0       0      1 

    M3X             14     0     0    0         0       0     14 

    --------------------------------------------------------------------------

    Total           16     0     0    0         0       0     16

    --------------------------------------------------------------------------

     

    ***********************************************************************************************************

     

    Thnaks again !!

     

    P. 

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