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cds_thru unbound

csst

Dear All,

In LVS i get this error

*ERROR* Device 'cds_thru(RES)' on Schematic is unbound to any Layout device.

IC sub-version 5.10.41.500.6.143
Assura sub-version 4.1_USR4

How to fix this error?

Regards

 

  • Thank you for the reply, but i have no access in Cadence Online Support.

    It would be greatly appreciated if you could paste the answer in this post. 

    Regards

  • Problem

    The cds_thru device from the "basic" library is used when it is required to join up 2 different pins in a schematic (.e.g to join up a VSSA net to a VSS net). How can an LVS mismatch due to this extra device be resolved?

    Solution

    The LVS mismatch can be resolved as follows:

    === Assura ===
    avCompareRules(
       schematic(
          filterDevice("cds_thru" short("src" "dst"))
       ) ;schematic
    ) ;avCompareRules

    Using the above command, Assura will filter the cds_thru device from the schematic and short the 2 terminals. The net connecting to the 1st terminal specified in the command will be retained. For the above example, it will be the net connecting to the "src" terminal.

    For a CDL netlist input, the command would be:

    avCompareRules(
       schematic(
          filterDevice( "SH" short("src" "dst"))
       ) ;schematic
    ) ;avCompareRules

    cds_thru is exported to a CDL netlist as a resistor with the model "SH" and resistance 0.1 ohms. Alternatively, the following CDL control command can be used in the CDL netlist:
    *.RESI 2000

    The above means that resistors with R values of 2000 and below will be automatically shorted.

    === PVS ===
    lvs_filter_device R(SH) -short -source

    === Calibre ===
    LVS FILTER R(SH) SHORT SOURCE

     

  •  Thank you so much

    adding

       schematic(
          filterDevice( "SH" short("src" "dst"))
       ) ;schematic

     in avCompareRules() in  compare.rul file   fixed the error.

    Kind Regards

  •  Hi csst,

         I also deals with the same problem. I am using IC615 and for verifying LVS i am using calibre.  I added the line LVS FILTER R(SH) SHORT SOURCE in lvs.rul file. But it shows compilation error. How to resolve this problem in Calibre.

    Thanks & Regards,

    Karthik.

  • You might want to ask Mentor this or read the Mentor Calibre documentation. Another approach is to ensure that *.RESI is set in the CDL netlist (this can be set on the File->Export->CDL form) so that resistors with values smaller than the threshold get shorted. I'm not sure if you have to do anything in Calibre to get it to honour *.RESI

    Regards,

    Andrew 

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