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Place multi-vt cells with Vt implant layer MinWidth requirements

guilhermess

Hi,

I am trying to run placement on a test block that has many instances of an INVX1, which is 2 columns wide. I have 3 different flavors of INVX1 instances in the design: LVT, RVT and HVT.

Each of these Vt implant layers has a width requirement of at least 3 columns. So if SoC Encounter places in a row:

... [INVX1_RVT] [INVX1_LVT] [INVX1_RVT]...

The INVX1_LVT instance will trigger an LVT MinWidth violation.

My tech lef is coded as following:

LAYER LVT

  TYPE IMPLANT ;

  WIDTH <my_3_column_width_value> ;

END LVT

My std cell macros contain the obstructions for the Vt layers

MACRO INVX1_LVT

...

OBS

  LAYER LVT

    RECT 0.000 0.000 <my_2_column_width_value> <my_cell_height> ;

My question is: how to get SoC Encounter to place the cells to avoid MinWidth Vt violations? Encounter can correctly identify the MinWidth DRC violations but placeDesign or addFiller -fixDRC does not seem to solve it or take it into consideration.

The solution I'd expect is to have cells of the same Vt grouped together (or with a filler of the same Vt) to have at least the min width of 3 columns.

Thank you in advance.

Regards.

Parents

  • The tool should handle this in version 14.2 or earlier, but only if you set this option:

    setPlaceMode -honorImplantSpacing true

    In newer versions of the tool this option is obsolete since the tool honors implant min width/spacing automatically if specified in the tech lef.

    You might also want to have a SPACING rule for each implant layer (in addition to WIDTH which you already have).

    Hope this helps,
    Bob

Reply

  • The tool should handle this in version 14.2 or earlier, but only if you set this option:

    setPlaceMode -honorImplantSpacing true

    In newer versions of the tool this option is obsolete since the tool honors implant min width/spacing automatically if specified in the tech lef.

    You might also want to have a SPACING rule for each implant layer (in addition to WIDTH which you already have).

    Hope this helps,
    Bob

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