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Calibre LVS errors for a design generated in Encounter

oAwad

Hello all,

 I made a design in SoC Encounter using NangateOpenCellLibrary 45nm. The layout had zero geometry and connectivity violations. I then needed to go to Calibre for LVS and PEX in order to do post-layout simulations, so I did the following in Encounter:

1) Design > Save > GDS/OASIS, then I provided the map file and merged library gds file that came with PDK "NangateOpenCellLibrary.gds" and didn't select "Uniquify cell names"....then finally hit Ok.

2)Design > Save > Netlist,  and I selected the two options in the window and hit Ok.

Then for Calibre part:

1) I run "v2lvs" command to generate spice netlist for LVS

2) I then run LVS using Calibre -gui

In LVS transcript window, I get tons of these two warnings: 

 Open circuit - Same name on different nets:

 Top level port name "KEXP0/n2089" at location (3.515,165.69) on net 2 not valid for netlisting; net id used instead.

(I think the above warning is the reason of the errors)

and in the LVS report I get these:

Error: Different numbers of ports (see below).
Error: Different numbers of nets (see below).
Error: Different numbers of instances (see below).
Error: Connectivity errors.
Error: Property errors.
Warning: Unbalanced smashed mosfets were matched.
Warning: Ambiguity points were found and resolved arbitrarily.
Warning: LVS property resolution maximum exceeded.


NUMBERS OF OBJECTS AFTER TRANSFORMATION
---------------------------------------

Layout   Source    Component Type

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

Ports: 12065       35        *

Nets:  29877   29720      *

Instances: 1265 1261      * MN (4 pins)
                  790 790         MP (4 pins)
                  5781   0          * _invb (6 pins)
                 10551 16326   * _invv (4 pins)

(If you added instance "_invb" and "_invv" in both layout and source, they have the same total)

I don't have experience to debug these errors, so can anyone tell me how to debug them ? 

 

Parents

  • While the GUI has a "Check" button to find the missing Global Net Connection (GNC), the GUI cannot be used in tcl mode.

    Here is a script to find the missing GNC:

    ============= missing_GNC.tcl =================
    set gncCheck [open GNCCheck.rpt w]
    foreach inst [dbGet top.insts] {
      foreach pgCellTermName [dbGet $inst.pgCellTerms.name] pgTermNetName [dbGet $inst.pgTermNets.name] {
        if {$pgTermNetName eq 0x0} {
          puts $gncCheck "[dbGet $inst.name] Term $pgCellTermName does not have p/g connection"
        }
      }
    }
    close $gncCheck

    ======================================

    Example:

    innovus > source missing_GNC.tcl

    After running the scripts, the tool gives all the missing global net connect information in the "GNCCheck.rpt" file as shown here:

    ============================================
    DTMF_INST/i_10048 Term VSS does not have p/g connection
    DTMF_INST/PLLCLK_INST Term vdd! does not have p/g connection
    DTMF_INST/RAM_128x16_TEST_INST/i_10074 Term VSS does not have p/g connection
    DTMF_INST/RAM_128x16_TEST_INST/i_14 Term VSS does not have p/g connection
    DTMF_INST/RAM_128x16_TEST_INST/i_13 Term VSS does not have p/g connection
    DTMF_INST/RAM_128x16_TEST_INST/i_12 Term VSS does not have p/g connection
    DTMF_INST/RAM_128x16_TEST_INST/i_11 Term VSS does not have p/g connection
    =============================================

Reply

  • While the GUI has a "Check" button to find the missing Global Net Connection (GNC), the GUI cannot be used in tcl mode.

    Here is a script to find the missing GNC:

    ============= missing_GNC.tcl =================
    set gncCheck [open GNCCheck.rpt w]
    foreach inst [dbGet top.insts] {
      foreach pgCellTermName [dbGet $inst.pgCellTerms.name] pgTermNetName [dbGet $inst.pgTermNets.name] {
        if {$pgTermNetName eq 0x0} {
          puts $gncCheck "[dbGet $inst.name] Term $pgCellTermName does not have p/g connection"
        }
      }
    }
    close $gncCheck

    ======================================

    Example:

    innovus > source missing_GNC.tcl

    After running the scripts, the tool gives all the missing global net connect information in the "GNCCheck.rpt" file as shown here:

    ============================================
    DTMF_INST/i_10048 Term VSS does not have p/g connection
    DTMF_INST/PLLCLK_INST Term vdd! does not have p/g connection
    DTMF_INST/RAM_128x16_TEST_INST/i_10074 Term VSS does not have p/g connection
    DTMF_INST/RAM_128x16_TEST_INST/i_14 Term VSS does not have p/g connection
    DTMF_INST/RAM_128x16_TEST_INST/i_13 Term VSS does not have p/g connection
    DTMF_INST/RAM_128x16_TEST_INST/i_12 Term VSS does not have p/g connection
    DTMF_INST/RAM_128x16_TEST_INST/i_11 Term VSS does not have p/g connection
    =============================================

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