A

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Building Pcells with ROD Functions

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The Pcells described in this reference were built in part with relative object design functions (ROD), a set of high-level Cadence^® SKILL language functions for defining simple and complex layout objects and their relationships to each other. The following code examples demonstrate how to use ROD functions to build Pcells.

Multipart Paths, Subpaths, and Subrectangles

This code example utilizes the ROD function rodCreatePath to create a guardring consisting of an enclosure subpath and a subrectangle.

procedure(buildGuardRing(cv layer1 layer2 layer3 width1 width3
    length3 pathpnts terminal pinlabel enc offset chop)

; pinlabel is a boolean that determines whether a label will be
    created

    let(( guardRing )
    guardRing = rodCreatePath(
        ?cvId cv
        ?layer layer1
        ?width width1
        ?pts pathpnts
        ?encSubPath list( list(
            ?layer layer2
            ?enclosure enc
            ?choppable chop
            ?pin t
            ?termName terminal
            ?pinLabel pinlabel
            ?pinLabelHeight length3
            ?pinLabelLayer "text"
        ))
        ?subRect list( list(
            ?layer layer3
            ?width width3
            ?length length3
            ?endOffset offset
        ))
    )
))

Path Stitching with ROD Functions

This code example uses the ROD functions rodAlign and rodCreateRect to build a Pcell that can be used for path stitching. It is set up for double contacts.

To use this example,

1. Copy the sample mpu.tf from
   

   your_install_dir/tools/dfII/samples/techfiles/mpu.tf

   to the location where you store your libraries.
2. Comment out M1_POLY1 from the device class of the technology file.
   This is necessary because path stitching will see two contact definitions for the same layer and choose the single-contact definition
3. Create a new technology library using mpu.tf as the ASCII technology file.
4. Load this file into your new library.

You can now use double contacts for path stitching.

; Path Stitching Example

devices(
tcCreateDeviceClass( "symbolic" "syEnhContact"
    ; class parameters
    ( (viaLayer "cont") 
      (viaPurpose "drawing")
      (layer1 "poly1") 
      (purpose1 "drawing") 
      (layer2 "metal1") 
      (purpose2 "drawing")
      (encByLayer1 .4)
      (encByLayer2 .6)
    )
    ; formal parameters
    ( (w 1.8)
      (l .6)
      (row 1)
      (column 1)
      (xPitch 2.4)
      (yPitch 1.2)
      (xBias "center")
      (yBias "center")
    )
    cw = .6
    cs = .6
    lay1 = rodCreateRect(
        ?layer  list(layer1 purpose1)
        ?width   2 * encByLayer1 + column * w + (column - 1) * cs
        ?length  2 * encByLayer1 + row * l + (row - 1) * cs
        ?pin t
        ?termName "m1p"
    )
    lay2 = rodCreateRect(
        ?layer list(layer2 purpose2)
        ?width   2 * encByLayer2 + column * w + (column - 1) * cs
        ?length  2 * encByLayer2 + row * l + (row - 1) * cs
        ?pin t
        ?termName "m1p"
    )
    for(i 0 row - 1
      yStep = i * yPitch
      for(j 0 column - 1
        contlay1 = rodCreateRect(
                ?layer  list(viaLayer viaPurpose)
                ?width cw
                ?length cw
        )
        contlay2 = rodCreateRect(
                ?layer  list(viaLayer viaPurpose)
                ?width cw
                ?length cw
        )
        rodAlign(
                ?alignObj contlay1
                ?alignHandle "cC"
                ?refObj lay1
                ?refHandle "lL"
                ?xSep encByLayer1 + cw/2 + j * xPitch
                ?ySep encByLayer1 + cw/2 + yStep
        )
        rodAlign(
                ?alignObj contlay2
                ?alignHandle "cC"
                ?refObj lay1
                ?refHandle "lL"
                ?xSep encByLayer1 + cw/2 + j * xPitch + yPitch
                ?ySep encByLayer1 + cw/2 + yStep
        )
      )
    )
    rodAlign(
       ?alignObj lay1
       ?alignHandle "centerCenter"
       ?refObj lay2
       ?refHandle "cC"
    )
)
tfcDefineDeviceClassProp(
; (viewName        devClassName      propName          propValue)
  (symbolic        syEnhContact      function          "contact")
)
tcDeclareDevice( "symbolic" "syEnhContact" "M1_PLY"
    ( (viaLayer "cont") (viaPurpose "drawing")
      (layer1 "poly1") (purpose1 "drawing")
      (layer2 "metal1") (purpose2 "drawing")
      (encByLayer1 .4) (encByLayer2 .6))
    (
      (w 1.8) (l .6)
      (row 1) (column 1)
      (xPitch 2.4)
      (yPitch 1.2)
      (xBias "center")
      (yBias "center")
    )
)
)