2

---

LEF Syntax - Layer (Cut)

---

This chapter contains information about the following topics:

• Layer (Cut)
  • Defining Cut Layer Properties to Create 32/28 nm and Smaller Nodes Rules
  • Type Rule
  • Adjacent Four Cuts Rule
  • Antenna Diff Gate PWL Rule
  • Antenna Diff Only Area Ratio Rule
  • Antenna Diff Protector Area Ratio Rule
  • Antenna Gate PWL Rule
  • Antenna Gate Plus Diffusion Rule
  • Array Spacing Rule
  • Backside Rule
  • Cut Class Rule
  • Cut On Center Line Rule
  • Directional Spacing Rule
  • Enclosure Rule
  • Enclosure Edge Rule
  • Enclosure Table Rule
  • Enclosure Width Rule
  • Enclosure Joint Rule
  • EOL Enclosure Rule
  • EOL Spacing Rule
  • Forbidden Spacing Rule
  • Keep-out Zone Rule
  • Manufacturing Grid Rule
  • Maximum Spacing Rule
  • Minimum Enclosure Rule
  • No Cut Class Rule
  • No Metal Spacing Rule
  • Spacing with Same Metal Rule
  • Spacing Table Rule
  • Spacing Table with Center Spacing Rule
  • One Array Rule
  • Opposite Overlap Cut Spacing Rule
  • Orthogonal Spacing Rule
  • PRL Two Sides Spacing Rule
  • Region Rule
  • Same-Metal Aligned Cuts Rule
  • Via Cluster Rule
  • Via Group Rule
  • Via Group Override Spacing Rule
  • Via Group Spacing Rule
  • Voltage Spacing Rule

Layer (Cut)

LAYER layerName
TYPE CUT ;
[MASK maskNum ;]
[SPACING cutSpacing 
   [CENTERTOCENTER]
   [SAMENET]
   [  LAYER secondLayerName [STACK] 
    | ADJACENTCUTS {2 | 3 | 4} WITHIN cutWithin [EXCEPTSAMEPGNET] 
    | PARALLELOVERLAP 
    | AREA cutArea
   ]
;] ...
[SPACINGTABLE ORTHOGONAL 
       {WITHIN cutWithin SPACING orthoSpacing} ... ;]
[ARRAYSPACING [LONGARRAY] [WIDTH viaWidth] CUTSPACING cutSpacing 
   {ARRAYCUTS arrayCuts SPACING arraySpacing} ... ;]
[WIDTH minWidth ;]
[ENCLOSURE [ABOVE | BELOW] overhang1 overhang2 
  [ WIDTH minWidth [EXCEPTEXTRACUT cutWithin] 
  | LENGTH minLength] 
;] ...
[PREFERENCLOSURE [ABOVE | BELOW] overhang1 overhang2 [WIDTH minWidth] ;] ...
[RESISTANCE resistancePerCut ;]
[PROPERTY propName propVal ;] ...
[ACCURRENTDENSITY {PEAK | AVERAGE | RMS}
  { value 
  | FREQUENCY freq_1 freq_2 ... ;
      [CUTAREA cutArea_1 cutArea_2 ... ;]
      TABLEENTRIES
       v_freq_1_cutArea_1 v_freq_1_cutArea_2 ...
       v_freq_2_cutArea_1 v_freq_2_cutArea_2 ...
       ...
  } ;]
[DCCURRENTDENSITY AVERAGE
  { value 
  | CUTAREA cutArea_1 cutArea_2 ... ;
      TABLEENTRIES value_1 value_2 ...
  } ;]
[ANTENNAMODEL {OXIDE1 | OXIDE2 | OXIDE3 | OXIDE4 | OXIDE5 | ...
  | OXIDE32}
;] ...
[ANTENNAAREARATIO value ;] ...
[ANTENNADIFFAREARATIO {value | PWL ( ( d1 r1 ) ( d2 r2 ) ...)} ;] ...
[ANTENNACUMAREARATIO value ;] ...
[ANTENNACUMDIFFAREARATIO {value | PWL ( ( d1 r1 ) ( d2 r2 ) ...)} ;] ...
[ANTENNAAREAFACTOR value [DIFFUSEONLY] ;] ...
[ANTENNACUMROUTINGPLUSCUT ;]
[ANTENNAGATEPLUSDIFF plusDiffFactor ;]
[ANTENNAAREAMINUSDIFF minusDiffFactor ;]
[ANTENNAAREADIFFREDUCEPWL 
   ( ( diffArea1 diffAreaFactor1 ) ( diffArea2 diffAreaFactor2 ) ...) ; ]
[PROPERTY LEF58_TYPE 
  “TYPE [TSV [LAYER bottomLayer topLayer]| PASSIVATION 
     | MIMCAP | HIGHR | SPECIALCUT LAYER bottomLayer topLayer]
     ;” ;]
[PROPERTY LEF58_ADJACENTFOURCUTS 
  "ADJACENTFOURCUTS cutSpacing CUTCLASS {className [TO ALL] | ALL} 
     {ABOVE | BELOW}
     PARALLEL parLength WITHIN parWithin [MERGEDCUTS]
     [HORIZONTAL|VERTICAL]
     [EXCEPTDIFFMETAL [NOEXTRACUT]]
     [MINCORNER | MININNERCORNER | MAXINNERCORNER]
     [EXCEPTMAXPRL maxPrl]
     [EXCEPTMINLENGTH minLength]
     [WITHINCUT within]
     [EXCEPTOTHERWIDTHWITHCUT width]
     [METALWIDTH maxWidth]
     ; " ;] 
[PROPERTY LEF58_ANTENNADIFFGATEPWL 
  "ANTENNADIFFGATEPWL {OXIDE1 | OXIDE2 | OXIDE3 | OXIDE4 | OXIDE5 | ...
   | OXIDE32} 
   ((gateArea1 effectiveGateArea1) (gateArea2 effectiveGateArea2) ... )
   ;" ;]
[PROPERTY LEF58_ANTENNADIFFONLYAREARATIO
  “ANTENNADIFFONLYAREARATIO {OXIDE1 | OXIDE2 | OXIDE3 | OXIDE4 
     | OXIDE5 | ... | OXIDE32}  value
   ;..." ;]
[PROPERTY LEF58_ANTENNADIFFPROTECTORAREARATIO
  “ANTENNADIFFPROTECTORAREARATIO {OXIDE1 | OXIDE2 | OXIDE3 
     | OXIDE4 | OXIDE5 | ...| OXIDE32}  value
   ;..." ;]
[PROPERTY LEF58_ANTENNAGATEPWL 
  "ANTENNAGATEPWL {OXIDE1 | OXIDE2 | OXIDE3 | OXIDE4 | OXIDE5 | ...
   | OXIDE32} 
   ((gateArea1 effectiveGateArea1) (gateArea2 effectiveGateArea2) ... )
   ;" ;]
[PROPERTY LEF58_ANTENNAGATEPLUSDIFF
  "ANTENNAGATEPLUSDIFF {OXIDE1 | OXIDE2 | OXIDE3 | OXIDE4 | OXIDE5 | ...
   | OXIDE32} 
   {plusDiffFactor | 
   PWL ((diffArea1 plusDiffProtect1) (diffArea1 plusDiffProtect2) ...)}    ;" ;]
[PROPERTY LEF58_ARRAYSPACING 
  "ARRAYSPACING [CUTCLASS className] [PARALLELOVERLAP] 
     [LONGARRAY] [WIDTH viaWidth] 
     [WITHIN within ARRAYWIDTH arrayWidth] CUTSPACING cutSpacing 
     {ARRAYCUTS arrayCuts SPACING arraySpacing} ... 
     ;..." ;]
[PROPERTY LEF58_BACKSIDE 
  “BACKSIDE ;” ;] 
[PROPERTY LEF58_CUTCLASS
  "CUTCLASS className WIDTH viaWidth [LENGTH viaLength] [CUTS numCut]
      [ORIENT {HORIZONTAL | VERTICAL}]
      ; " ;]
[PROPERTY LEF58_CUTONCENTERLINE
  "CUTONCENTERLINE width CUTCLASS className [ABOVE | BELOW]
     [EXTRACUT cutWithin WIDTH exactWidth]
     ; " ;]
[PROPERTY LEF58_DIRECTIONALSPACING
  "DIRECTIONALSPACING cutSpacing {HORIZONTAL | VERTICAL}
     PRL prl
     CUTCLASS className1 TO className2
     [PARALLEL parLength WITHIN parWithin
         [EXCLUDECUTEDGE]
         [CUTS numCuts]
         [VIAGROUP groupName]]
     ; " ;]
[PROPERTY LEF58_ENCLOSURE 
  "ENCLOSURE [CUTCLASS className][ABOVE | BELOW]
     [MINCORNER]
     {EOL eolWidth [HORIZONTAL | VERTICAL]
         [MINLENGTH minLength]
         [EOLONLY] [SHORTEDGEONEOL] eolOverhang otherOverhang 
         [SIDESPACING spacing EXTENSION backwardExt forwardExt
         |ENDSPACING spacing EXTENSION extension
         ]
    |{overhang1 overhang2
       |[OFFCENTERLINE] END overhang1 SIDE overhang2
       |HORIZONTAL overhang1 VERTICAL overhang2}
       [JOGLENGTHONLY length [INCLUDELSHAPE] ]
       [HOLLOW {HORIZONTAL|VERTICAL} length] 
       [ WIDTH minWidth 
           [INCLUDEABUTTED]
           [EXCEPTEXTRACUT cutWithin 
                [PRL | NOSHAREDEDGE | EXACTPRL prl]]
       | LENGTH minLength 
       | EXTRACUT [EXTRAONLY [PRL prl]]   
       | REDUNDANTCUT cutWithin
       | PARALLEL parLength [parLength2] WITHIN parWithin [parWithin2]
           [BELOWENCLOSURE belowEnclosure
                [ALLSIDES enclosure1 enclosure2]
           |ABOVEENCLOSURE aboveEnclosure]
       | CONCAVECORNERS numCorner
       | OTHERWITHINWIDTH width WITHIN within
       [ OTHERSIDE otherEnclosure]]
     }
     ;..." ;]
[PROPERTY LEF58_ENCLOSUREEDGE 
  "ENCLOSUREEDGE [CUTCLASS className][ABOVE | BELOW] overhang 
      {OPPOSITE 
           {[EXCEPTEOL eolWidth] [NOCONCAVECORNER within]
                [CUTTOBELOWSPACING spacing
                    [ABOVEMETAL extension]]
           | WRONGDIRECTION 
           }
      |[INCLUDECORNER]
        {WIDTH [BOTHWIRE] minWidth [maxWidth]
       |SPANLENGTH minSpanLength [maxSpanLength]}
           PARALLEL parLength
           {WITHIN parWithin | WITHIN minWithin maxWithin} 
           [EXCEPTEXTRACUT [cutWithin]] 
           [EXCEPTTWOEDGES [exceptWithin]]
      |CONVEXCORNERS convexLength adjacentLength
           PARALLEL parWithin LENGTH length
      }
  ;..." ;]
[PROPERTY LEF58_ENCLOSURETABLE
  "ENCLOSURETABLE [CUTCLASS className] [MASK maskNum]
      [OTHERMASK otherMaskNum]
          [USEMAXWIDTH | USEMINWIDTH | WITHINFIRSTWIDTH]
      [DEFAULT {[ABOVE| BELOW] 
          overhang1 overhang2 overhang3 overhang4}...]
      {WIDTH width {[ABOVE| BELOW] 
          overhang1 overhang2 overhang3 overhang4 [MINSUM]
          [MUSTUSE]
          [MAXLENGTH length | LENGTH length]
          [LAYER trimLayer OVERLAP {1|2} 
                [TRIMLENGTHOUTERMETAL trimLength]
          | OTHERWITHINWIDTH width [LAYER layerName]
                WITHIN within 
                [OTHERSIDE otherEnclosure]]
          | LINEENDGAPONLY
          | ROWBOUNDARY within OTHERSIDE otherEnclosure]
          [EXACTZERO]
          [INCLUDEABUTTED]}...
      | OTHERWIDTH otherWidth [PARALLEL parLength WITHIN parWithin]
          {{ABOVE| BELOW}
          overhang1 overhang2 overhang3 overhang4 [MINSUM]}...}...
      ; " ;]
[PROPERTY LEF58_ENCLOSURETOJOINT 
  "ENCLOSURETOJOINT [CUTCLASS className] [ABOVE | BELOW] 
      toOneJointOverhang [toBothJointOverhang] 
      [EOLMINLENGTH minLength]
      JOINTWIDTH jointWidth JOINTLENGTH spanLength 
      ; " ;]
[PROPERTY LEF58_ENCLOSUREWIDTH 
  "ENCLOSUREWIDTH {VIAOVERLAPONLY | USEMINWIDTH}
      ;..." ;]
[PROPERTY LEF58_EOLENCLOSURE
  "EOLENCLOSURE eolWidth [MINEOLWIDTH minEolWidth]
      [HORIZONTAL | VERTICAL]
      [EQUALRECTWIDTH] [CUTCLASS className] [ABOVE | BELOW]
      {{LONGEDGEONLY | SHORTEDGEONLY} overhang 
      |overhang
            [exactOverhang
            |PARALLELEDGE parSpace EXTENSION backwardExt forwardExt
                  [MINLENGTH minLength]
            |MINLENGTH minLength
            |ALLSIDES
            ]
      }
      ; " ;]
[PROPERTY LEF58_EOLSPACING
  "EOLSPACING cutSpacing1 cutSpacing2
      [CUTCLASS className1 [{TO className2 cutSpacing1 cutSpacing2}...]]
      ENDWIDTH eolWidth PRL prl
      ENCLOSURE smallerOverhang equalOverhang
      EXTENSION sideExt backwardExt SPANLENGTH spanLength
      ; " ;]
[PROPERTY LEF58_FORBIDDENSPACING
  "FORBIDDENSPACING CUTCLASS className minSpacing maxSpacing 
      [SAMEMASK]
      [SHORTEDGEONLY | LONGEDGEONLY | HORIZONTAL | VERTICAL]
      [PRL {prl TO prlClassName}...]
      ; " ;]
[PROPERTY LEF58_KEEPOUTZONE
  "KEEPOUTZONE CUTCLASS className1 [TO className2]
      [SAMEMASK][SAMEMETAL | DIFFMETAL]
      [EXCEPTEXACTALIGNED [SIDE | END] spacing]
      {EXTENSION sideExtension forwardExtension | 
      ENDEXTENSION endSideExtension endForwardExtension 
      SIDEEXTENSION sideSideExtension sideForwardExtension |
      HORIZONTALEXTENSION horzSideExtension horzForwardExtension
      VERTICALEXTENSION vertSideExtension vertForwardExtension}
      SPIRALEXTENSION extension [CORNERONLY]
      ;" ;]
[PROPERTY LEF58_MANUFACTURINGGRID 
  "MANUFACTURINGGRID value 
  ; " ;]
[PROPERTY LEF58_MAXSPACING
  "MAXSPACING spacing [CUTCLASS className]
  ;" ;]
[PROPERTY LEF58_MINENCLOSURE
  "MINENCLOSURE CUTCLASS className [ABOVE | BELOW]
      overhang1 overhang2
      ; " ;]
[PROPERTY LEF58_NOCUTCLASS
  "NOCUTCLASS className [EXCEPTMULTICUTS]
  ;" ;]
[PROPERTY LEF58_NOMETALSPACING
  "NOMETALSPACING spacing BOTHSPACING bothSpacing [PRL prl]
      [SAMEMASK] [CUTCLASS className] 
      NEIGHBORMETAL metalPrl metalWithin
        noMetalPrl {noMetalWithin | noMetalLowWithin noMetalHighWithin}
      [SAMESIDE]
      [ABOVE | BELOW] [EXCEPTLINEENDSPACING lineEndSpacing]
       ;" ;]
[PROPERTY LEF58_ONEDARRAY 
  "ONEDARRAY CUTCLASS className CUTSPACING cutSpacing 
      ARRAYCUTS arrayCuts SPACING spacing 
      LAYER secondLayerName SPACING interLayerSpacing 
      ENCLOSURE overhang1 overhang2 
      ; " ;]
[PROPERTY LEF58_ORTHOGONALSPACING 
  "ORTHOGONALSPACING cutSpacing 
      [CUTCLASS className [TO ALL]] {ABOVE | BELOW}
      PARALLEL parLength WITHIN parWithin WIDTH width
      [METALPRL metalPrl METALWITHIN metalWithin]
      [HORIZONTAL | VERTICAL]
      ; " ;]
[PROPERTY LEF58_OPPOSITEOVERLAPCUTSPACING 
  "OPPOSITEOVERLAPCUTSPACING spacing PRL prl 
      LAYER secondLayerName
      ; " ;]
[PROPERTY LEF58_PRLTWOSIDESPACING 
  "PRLTWOSIDESSPACING prlSpacing nonPrlSpacing 
      CUTCLASS className1 TO className2
      PRL prl1 prl2 prl3 prl4 
      ; " ;]
[PROPERTY LEF58_REGION
  "REGION regionLayerName BASEDLAYER cutLayerName
  ; " ;]
[PROPERTY LEF58_SAMEMETALALIGNEDCUTS
  "SAMEMETALALIGNEDCUTS numCuts 
      CUTCLASS {className | ALL}
      | {CUTCLASSLIST {classNameList}...}...}
      [ABOVE | BELOW] WIDTH width SPACING spacing
      [METALMASK metalMaskNum]
      [PARALLEL parLength WITHIN parWithin
      | METALWITHIN metalWithin [WITHCUT]
      | CUTWITHIN cutWithin
      |NOVIAOVERLAPMETAL within]
      [CENTERTOCENTER | EDGETOEDGE]
      ; " ;]
[PROPERTY LEF58_SPACING 
  "SPACING cutSpacing 
     [SAMEMASK 
     |MAXXY
     |[CENTERTOCENTER]
       [SAMENET | SAMEMETAL | SAMEVIA]
       [LAYER secondLayerName
            [STACK
            | ORTHOGONALSPACING orthogonalSpacing]
            | CUTCLASS className 
                [SHORTEDGEONLY [PRL prl]
                |CONCAVECORNER 
                     [WIDTH width ENCLOSURE enclosure 
                         EDGELENGTH edgeLength
                     | PARALLEL parLength WITHIN parWithin 
                         ENCLOSURE enclosure
                     | EDGELENGTH edgeLength 
                         ENCLOSURE edgeEnclosure adjEnclosure]
                |EXTENSION extension 
                |NONEOLCONVEXCORNER eolWidth
                     [MINLENGTH minLength]
                |ABOVEWIDTH width [ENCLOSURE enclosure] 
                |MASKOVERLAP 
                |WRONGDIRECTION [EXCEPTRECTANGLE]
                |DIFFCONCAVECORNER ]]] 
       | ADJACENTCUTS {2 | 3 | 4}
            [EXACTALIGNED exactAlignedCut]
            [TWOCUTS twoCuts [TWOCUTSSPACING twoCutsSpacing]
                [SAMECUT] 
            | EACHCUTS numCuts [EXCEPTEVENNUMCUT]]  
            WITHIN {cutWithin | cutWithin1 cutWithin2}
            [EXCEPTSAMEPGNET]
            [EXCEPTALLWITHIN exceptAllWithin]
            [ENCLOSURE [ABOVE|BELOW] enclosure
                [METALMASK metalMaskNum]
                [METALWIDTH maxWidth]
                [EXCEPTLINEENDGAP]]
            [CUTCLASS className [TO ALL]]
            [NOPRL [HORIZONTAL|VERTICAL] | SIDEPARALLELOVERLAP] 
            [SAMEMASK]
       | PARALLELOVERLAP [EXCEPTSAMENET | EXCEPTSAMEMETAL 
            |EXCEPTSAMEMETALOVERLAP | EXCEPTSAMEVIA] 
       | PARALLELWITHIN within [EXCEPTSAMENET]
            [CUTCLASS className
                 [LONGEDGEONLY
                 | ENCLOSURE enclosure {ABOVE | BELOW}
                     PARALLEL parLength WITHIN parWithin]]
       | SAMEMETALSHAREDEDGE parwithin [ABOVE][CUTCLASS className]
            [EXCEPTTWOEDGES] [EXCEPTSAMEVIA numCut]
       | AREA cutArea]
   ;..." ;]
[PROPERTY LEF58_SPACINGTABLE
  "SPACINGTABLE CENTERSPACING
     LAYER secondLayerName
     [OVERLAPMETALSPACING metalLayerName WIDTH width
         {className1 TO className2 spacing}...]
     CUTCLASS {{className1 | ALL} }...
         {{className2 | ALL} {cutSpacing}...}... 
  ; " ;]
[PROPERTY LEF58_SPACINGTABLE 
  “SPACINGTABLE  
     [ORTHOGONAL 
        {WITHIN cutWithin SPACING orthoSpacing} ... ;
     |[DEFAULT defaultCutSpacing]
        [SAMEMASK]
        [SAMENET | SAMEMETAL | SAMEVIA]
        [LAYER secondLayerName
              [NOSTACK] 
              [NONZEROENCLOSURE
              | PRLFORALIGNEDCUT 
                {{className1 | ALL} TO {className2 | ALL} }...
              | EXCEPTENCLOSURE exceptEnclosure]]
        [CENTERTOCENTER
              {{className1 | ALL}| TO {className2 | ALL}}...]
        [CENTERANDEDGE [NOPRL] 
              {{className1 | ALL}| TO {className2 | ALL}}...]
        [PRLSPACING spacing PRL prl]
        [PRL {prl|USEDEFAULT} [ HORIZONTAL| VERTICAL][MAXXY]
              [{{className1 | ALL} TO {className2 | ALL} ccPrl
                      [ HORIZONTAL| VERTICAL] }...] ]
        [PRLTWOSIDES
             {prl1 prl2 prl3 prl4 [WITHIN within]
                    className1 TO className2 spacing}...]
        [ENDEXTENSION extension [{TO className classExtension}...]
              [SIDEEXTENSION {TO className classExtension}...] ]
        [EXACTALIGNEDSPACING [HORIZONTAL | VERTICAL] 
              {{className | ALL} exactAlignedSpacing}...]
        [NONOPPOSITEENCLOSURESPACING 
              {className nonOppositeEnclosureSpacing}...]
        [OPPOSITEENCLOSURERESIZESPACING 
              {className resize1 resize2                  oppositeEnclosureResizeSpacing}...
              [EDGEALIGNED [HORIZONTAL|VERTICAL]]]
        CUTCLASS { {className1 | ALL} [SIDE | END]}...
          {{className2 | ALL} [SIDE | END] {-|cutSpacing1} 
            {-|cutSpacing2}...}...;
     ]
      ; " ;]
[PROPERTY LEF58_VIACLUSTER
  "VIACLUSTER CUTCLASS className
      CUTS perpendicularNumCut
      [DIAGONAL diagonalNumCut]
          [NOPRLSPACING diagonalSpacing bendSpacing WITHIN within
          EXTENSION sideExtension edgeExtension]]
      WITHIN minWithin maxWithin
      ; " ;]
[PROPERTY LEF58_VIAGROUP
  "VIAGROUP groupName CUTS numCut CUTCLASS {{className}... | All}
      [SAMEMASK]
      {{[PRLTWOSIDES prl1 prl2 prl3 prl4] SPACING minSpacing maxSpacing
        | PRL prl PRLSPACING prlSpacing [HORIZONTAL|VERTICAL]}
            [ALLOWBEND [NOHORIZONTAL|NOVERTICAL]]
      | ALIGNEDSPACING {HORIZONTAL | VERTICAL} 
            minSpacing maxSpacing }
      ; " ;]
[PROPERTY LEF58_VIAGROUPOVERRIDESPACING
  "VIAGROUPOVERRIDESPACING
      ; " ;]
[PROPERTY LEF58_VIAGROUPSPACING
  "VIAGROUPSPACING spacing 
      [SAMEMASK | DIFFMASK]
      [{HORIZONTAL| VERTICAL} [PRL prl] [TWOSIDES]]
      VIAGROUP groupName CUTS numCut 
      [LAYER cutLayerName] CUTCLASS {className | All}
      [TOVIAGROUP]
      [MERGEDCUTS | NOMERGEDCUTS]
      [PARALLEL parLength WITHIN parWithin 
          OTHERCUTCLASS otherClassName]
      ; " ;]
[PROPERTY LEF58_VOLTAGESPACING 
  "VOLTAGESPACING {voltage spacing}...
       ;..." ;]

END layerName

Defines cut layers in the design. Each cut layer is defined by assigning it a name and design rules. You must define cut layers separately, with their own layer statements.

You must define layers in process order from bottom to top. For example:

poly       masterslice

cut01      cut

metal1     routing

cut12      cut

metal2     routing

cut23      cut

metal3     routing

ACCURRENTDENSITY

Specifies how much AC current a cut of a certain area can handle at a certain frequency. For an example using the ACCURRENTDENSITY syntax, see Example 5-1.

The ACCURRENTDENSITY syntax is defined as follows:

{PEAK | AVERAGE | RMS} 
{ value 
| FREQUENCY freq_1 freq_2 ... ; 
    [CUTAREA cutArea_1 cutArea_2 ...  ; ]
    TABLEENTRIES 
    v_freq_1_cutArea_1 v_freq_1_cutArea_2 ...
    v_freq_2_cutArea_1 v_freq_2_cutArea_2 ...
    ...
} ;  

ANTENNAAREADIFFREDUCEPWL ( ( diffArea1 diffAreaFactor1 ) ( diffArea2 diffAreaFactor2 ) ...)

Indicates that the cut_area is multiplied by a diffAreaFactor computed from a piece-wise linear interpolation, based on the diffusion area attached to the cut.

The diffArea values are floats, specified in microns squared. The diffArea values should start with 0 and monotonically increase in value to the maximum size diffArea possible. The diffAreaFactor values are floats with no units. The diffAreaFactor values are normally between 0.0 and 1.0. If no statement rule is defined, the diffMetalReduceFactor value in the PAR(m_i) equation defaults to 1.0.

For more information on the PAR(m_i) equation and process antenna models, see Appendix C, “Calculating and Fixing Process Antenna Violations.”

ANTENNAAREAFACTOR value [DIFFUSEONLY]

Specifies the multiply factor for the antenna metal area calculation. DIFFUSEONLY specifies that the current antenna factor should only be used when the corresponding layer is connected to the diffusion.
Default: 1.0 Type: Float

For more information on process antenna calculation, see Appendix C, “Calculating and Fixing Process Antenna Violations.”

Note: If you specify a value that is greater than 1.0, the computed areas will be larger, and violations will occur more frequently.

ANTENNAAREAMINUSDIFF minusDiffFactor

Indicates that the antenna ratio cut_area should subtract the diffusion area connected to it. This means that the ratio is calculated as:

ratio = ( cutFactor x cut_area - minusDiffFactor x diff_area)/gate_area

If the resulting value is less than 0, it should be truncated to 0. For example, if a via2 shape has a final ratio that is less than 0 because it connects to a diffusion shape, then the cumulative check for metal3 (or via3) above the via2 shape adds a cumulative value of 0 from the via2 layer. (See Example 1 in Cut Layer Process Antenna Models, in Appendix C, “Calculating and Fixing Process Antenna Violations.”Type: Float
Default: 0.0

ANTENNAAREARATIO value

Specifies the maximum legal antenna ratio, using the area of the metal wire that is not connected to the diffusion diode. For more information on process antenna calculation, see Appendix C, “Calculating and Fixing Process Antenna Violations.”Type: Float

ANTENNACUMAREARATIO value

Specifies the cumulative antenna ratio, using the area of the metal wire that is not connected to the diffusion diode. For more information on process antenna calculation, see Appendix C, “Calculating and Fixing Process Antenna Violations.” Type: Float

ANTENNACUMDIFFAREARATIO {value | PWL ( ( d1 r1 ) ( d2 r2 )...)}

Specifies the cumulative antenna ratio, using the area of the metal wire that is connected to the diffusion diode. You can supply an explicit ratio value or specify piece-wise linear format (PWL), in which case the cumulative ratio is calculated using linear interpolation of the diffusion area and ratio input values. The diffusion input values must be specified in ascending order.
Type: Float

For more information on process antenna calculation, see Appendix C, “Calculating and Fixing Process Antenna Violations.”

ANTENNACUMROUTINGPLUSCUT

Indicates that cumulative ratio rules (that is, ANTENNACUMAREARATIO, and ANTENNACUMDIFFAREARATIO) accumulate with the previous routing layer instead of the previous cut layer. Use this to combine metal and cut area ratios into one rule.

For more information on process antenna models, see Appendix C, “Calculating and Fixing Process Antenna Violations.”

ANTENNADIFFAREARATIO {value | PWL ( ( d1 r1 ) ( d2 r2 )...)}

Specifies the antenna ratio, using the area of the metal wire connected to the diffusion diode. You can supply an explicit ratio value or specify piece-wise linear format (PWL), in which case the ratio is calculated using linear interpolation of the diffusion area and ratio input values. The diffusion input values must be specified in ascending order.
Type: Float

For more information on process antenna calculation, see Appendix C, “Calculating and Fixing Process Antenna Violations.”

ANTENNAGATEPLUSDIFF plusDiffFactor

Indicates the antenna ratio gate area includes the diffusion area multiplied by plusDiffFactor. This means that the ratio is calculated as:

ratio = cut_area / (gate_area + plusDiffFactor x diff_area)

The ratio rules without “DIFF” (the ANTENNAAREARATIO, ANTENNACUMAREARATIO, ANTENNASIDEAREARATIO, and ANTENNACUMSIDEAREARATIO statements), are unnecessary for this layer if ANTENNAGATEPLUSDIFF is defined because a zero diffusion area is already accounted for by the ANTENNADIFF*RATIO statements.
Type: Float
Default: 0.0

For more information on process antenna models, see Appendix C, “Calculating and Fixing Process Antenna Violations.”

ANTENNAMODEL {OXIDE1 | OXIDE2 | OXIDE3 | OXIDE4 | OXIDE5 | ... | OXIDE32}

Specifies the oxide model for the layer. If you specify an ANTENNAMODEL statement, that value affects all ANTENNA* statements for the layer that follow it until you specify another ANTENNAMODEL statement.
Default: OXIDE1, for a new LAYER statement

Because LEF is sometimes used incrementally, if an ANTENNA statement occurs twice for the same oxide model, the last value specified is used. For any given ANTENNA keyword, only one value or PWL table is stored for each oxide metal on a given layer.

For an example using the ANTENNAMODEL syntax, see Example 5-2.

ARRAYSPACING

Specifies array spacing rules to use on the cut layer. An array spacing rule is intended for large vias of size 3x3 or larger.

The ARRAYSPACING syntax is defined as follows:

[ARRAYSPACING [LONGARRAY] [WIDTH viaWidth] CUTSPACING cutSpacing {ARRAYCUTS arrayCuts SPACING arraySpacing} ... ; ]

Example 2-1 Array Spacing Rules

• Array Spacing Rule Example 1
  Assume the following array spacing rule exists:

  ARRAYSPACING WIDTH 2.0 CUTSPACING 0.2 ARRAYCUTS 3 SPACING 1.0 ;

  Any via with a metal width greater than or equal to 2.0 μm should use the cut spacing of 0.2 μm between cuts inside 3x3 cut arrays, and the cut arrays should be spaced apart by a distance of greater than or equal to 1.0 μm from other cut arrays. This creates the via shown in Figure 2-1.
  An array of 3x4 or 3x5 cuts spaced 0.2 μm apart is a violation, unless the LONGARRAY keyword is specified. This is because the 3x3 sub-array, inside 3x4 or 3x5 cut array, does not meet 1.0 μm spacing from other cut arrays. Also, any larger array, such as 4x4 or 4x5 cuts, is a violation because the 3x3 sub-array inside 4x4 or 4x5 cut array requires 1.0 μm spacing from other cut arrays.
  Figure 2-1 Via Created With Array Spacing Width Rule
  
• Array Spacing Rule Example 2
  The following array spacing rule is the same as Example 1, except the LONGARRAY keyword is present and the WIDTH keyword is not specified, so it creates the via shown in Figure 2-2:

  ARRAYSPACING LONGARRAY CUTSPACING 0.2 ARRAYCUTS 3 SPACING 1.0 ;

  An array of 2x2, 2x3, or 2xM cuts ignores this rule.
  An array of 3x3 or 3xM must have 1.0 μm spacing from other cut arrays and 0.2 μm spacing between the cuts.
  An array of 4x4 or 4xM is a violation because the array does not have 1.0 μm space from the 3xM sub-array inside the 4xM array.
  Figure 2-2 Via Created With Array Spacing Long Array Rule
  
• Array Spacing Rule Example 3
  Assume the following multiple array spacing rules exist:

  ARRAYSPACING LONGARRAY CUTSPACING 0.2 

       ARRAYCUTS 3 SPACING 1.0 

       ARRAYCUTS 4 SPACING 1.5 

       ARRAYCUTS 5 SPACING 2.0 ;

  The application can choose between 3xM cut arrays with 1.0 μm spacing, 4xM cut arrays with 1.5 μm spacing, or 5xM cut arrays with 2.0 μm spacing, using 0.2 cut-to-cut spacing inside each cut array. No WIDTH value indicates that any via with more than three via cuts in both dimensions (that is, 3x3 and 3x4, but not 2x4) must follow these rules.

DCCURRENTDENSITY

Specifies how much DC current a via cut of a certain area can handle in units of milliamps per square micron (mA/μm²). For an example using the DCCURRENTDENSITY syntax, see Example 5-3.

The DCCURRENTDENSITY syntax is defined as follows:

AVERAGE { value | CUTAREA cutArea_1 cutArea_2 ... ;
TABLEENTRIES value_1 value_2 ... } ;

ENCLOSURE

Specifies an enclosure rule for the cut layer.

The ENCLOSURE syntax is described as follows:

[ENCLOSURE 
 [ABOVE | BELOW] overhang1 overhang2 
 [ WIDTH minWidth [EXCEPTEXTRACUT cutWithin] 
 | LENGTH minLength] 
;] 

Figure 2-3 Enclosure Rule

Example 2-2 Enclosure Rules

• The following definition describes a cut layer that has different enclosure rules for m1 below than for m2 above.
  

  LAYER via12

  TYPE CUT ;

  WIDTH 0.20 ;                    #cuts .20 x .20 squares

  ENCLOSURE BELOW .03 .01 ;       #m1: 0.03 on two opposite sides, 0.01 on other 

  ENCLOSURE ABOVE .05 .01 ;       #m2: 0.05 on two opposite sides, 0.01 on other

  RESISTANCE 10.0 ;               #10.0 ohms per cut

  ...

  END via12

• The following definition describes a cut layer that requires extra enclosure if the metal width is wider:
  

  LAYER via23

  TYPE CUT ;

  WIDTH 0.20 ;                  #cuts .20 x .20 squares

  SPACING 0.15                  #via23 edge-to-edge spacing is 0.15

  ENCLOSURE .05 .01 ;           #m2, m3: 0.05 on two opposite sides, 0.01 on 

                                #other sides

  ENCLOSURE .02 .02 WIDTH 1.0 ; #m2 needs 0.02 on all sides if m2 width >=1.0 

                                #m3 needs 0.02 on all sides if m3 width >=1.0

  ENCLOSURE .05 .05 WIDTH 2.0 ; #m2 needs 0.05 on all sides if m2 width >=2.0

                                #m3 needs 0.05 on all sides if m3 width >=2.0

  ...

  END via23

• The following definition describes a cut layer that requires an overhang of .07 μm on all sides of metal3, and an overhang of .09 μm on all sides of metal4, if the widths of metal3 and metal4 are greater than or equal to 1.0 μm:
  

  LAYER via34

  TYPE CUT ;

  WIDTH 0.25 ;                        #cuts .25 x .25 squares

  ENCLOSURE .05 .01 ;                 #minimum width enclosure rule

  ENCLOSURE BELOW .07 .07 WIDTH 1.0 ;  #m3 needs .07 on all sides if m3 width >=1.0 

  ENCLOSURE ABOVE .09 .09 WIDTH 1.0 ; #m4 needs .09 on all sides if m4 width >=1.0

  ...

  END via34

Example 2-3 Enclosure Rule With Width and ExceptExtraCut

The following definition describes a cut layer that requires an enclosure of either .05 μm on opposite sides and 0.0 μm on the other two sides, or 0.04 μm on opposites sides and 0.01 μm on the other two sides. It also requires an enclosure of 0.03 μm in all directions if the wire width is greater than or equal to 0.03 μm, unless there is an extra cut (redundant cut) within 0.2 μm.

LAYER via34 

TYPE CUT ;

WIDTH 0.10                      #cuts .10 x .10 squares

SPACING 0.10 ;                  #minimum edge-to-edge spacing is 0.10 

ENCLOSURE 0.0 0.05 ;            #overhang 0.0 0.05

ENCLOSURE 0.01 0.04 ;           #or, overhang 0.01 0.04 

#if width >= 0.3, need 0.03 0.03, unless extra cut across wire within 0.2μm

ENCLOSURE 0.03 0.03 WIDTH 0.3 EXCEPTEXTRACUT 0.2 ;

...

END via34

Figure 2-4 Illustrations of Enclosure Rule With Width and ExceptExtraCut

Example 2-4 Enclosure Rule With Length and Width

The following definition describes a cut layer that requires an enclosure of .05 μm on opposite sides and 0.0 μm on the other two sides, as long as the total length enclosure on any two opposite sides is greater than or equal to 0.7 μm. Otherwise, it requires 0.05 μm on all sides if the total enclosure length is less than or equal to 0.7 μm. It also requires 0.10 μm on all sides if the metal layer has a width that is greater than or equal to 1.0 μm. (Figure 2-5 illustrates examples of violations and acceptable vias for the three ENCLOSURE rules.)

LAYER via34 

TYPE CUT ;

WIDTH 0.20                          #cuts .20 x .20 squares

SPACING 0.20 ;                      #via34 edge-to-edge spacing is 0.20 

ENCLOSURE 0.05 0.0 LENGTH 0.7 ;     #overhang 0.05 0.0 if total overhang >= 0.7

ENCLOSURE 0.05 0.05 ;               #or, overhang 0.05 on all sides

ENCLOSURE 0.10 0.10 WIDTH 1.0 ;     #if width >= 1.0, always need 0.10 

...

END via34

Figure 2-5 Illustrations of Enclosure Rule With Length and Width

LAYER LayerName

Specifies the name for the layer. This name is used in later references to the layer.

MASK maskNum

Specifies how many masks for double- or triple-patterning will be used for this layer. The maskNum variable must be an integer greater than or equal to 2. Most applications support values of 2 or 3 only.

PREFERENCLOSURE [ABOVE | BELOW] overhang1 overhang2 [WIDTH minWidth]

Specifies preferred enclosure rules that can improve manufacturing yield, instead of enclosure rules that absolutely must be met (see the ENCLOSURE keyword). Applications should use the PREFERENCLOSURE rule when it has little or no impact on density and routability.

PROPERTY propName propVal

Specifies a numerical or string value for a layer property defined in the PROPERTYDEFINITIONS statement. The propName you specify must match the propName listed in the PROPERTYDEFINITIONS statement.

RESISTANCE resistancePerCut

Specifies the resistance per cut on this layer. LEF vias without their own specific resistance value, or DEF vias from a VIARULE without a resistance per cut value, can use this resistance value.

Via resistance is computed using resistancePerCut and Kirchoff’s law for typical parallel resistance calculation. For example, if R =10 ohms per cut, and the via has one cut, then R =10 ohms. If the via has two cuts, then R = (1/2) * 10 = 5 ohms.

SPACING

Specifies the minimum spacing allowed between via cuts on the same net or different nets. For via cuts on the same net, this value can be overridden by a spacing with the  SAMENET keyword. (See Example 2-5.)

The SPACING syntax is defined as follows:

[SPACING cutSpacing 
  [CENTERTOCENTER] 
  [SAMENET]  
  [ LAYER secondLayerName [STACK] 
  | ADJACENTCUTS {2 | 3 | 4} WITHIN cutWithin 
      [EXCEPTSAMEPGNET] 
  | PARALLELOVERLAP 
  | AREA cutArea] 
;] ... 

Example 2-5 Spacing Rule Examples

• Spacing Rule Example 1
  The following spacing rule defines the cut spacing required between a cut and the routing immediately above the cut. The spacing only applies to “outside edges” of the routing shape, and does not apply to a routing shape already overlapping the cut shape.

  LAYER cut12 

  SPACING 0.10 ;              #normal min cut-to-cut spacing 

  SPACING 0.15 LAYER metal2 ; #spacing from cut to routing edge above 

  ...

  END cut12 

  LAYER metal2 

  ...

  END metal2 

  
  
  
• Spacing Rule Example 2
  The following spacing rule specifies that extra space is needed for any via with more than three adjacent cuts, which happens if one via has more than 2x2 cuts (see Figure 2-6). A cut that is within .25 μm of three other cuts requires spacing that is greater than or equal to 0.22 μm.

  LAYER CUT12 

  SPACING 0.20 ;                           #default cut spacing

  SPACING 0.22 ADJACENTCUTS 3 WITHIN 0.25 ;

  ...

  END CUT12

  Adjacent Via Cuts
  A cut is considered adjacent if it is within distance of another cut in any direction (including a 45-degree angle). Figure 2-6 illustrates adjacent via cuts for 2x2, 2x3, and 3x3 vias, for typical spacing values (that is, the diagonal spacing is greater than the ADJACENTCUTS distance value). For three adjacent cuts, the ADJACENTCUTS rule allows tight cut spacing on 1xn vias and 2x2 vias, but requires larger cut spacing on 2x3, 2x4 and 3xn vias. For four adjacent cuts, the rule allows tight cut spacing on 2xn vias, but it requires larger cut spacing on 3xn vias.
  The ADJACENTCUTS rule overrides the cut-to-cut spacing used in VIARULE GENERATE statements for large vias if the ADJACENTCUTS spacing value is larger than the VIARULE spacing value.
  Figure 2-6
  
• Spacing Rule Example 3
  The following spacing rule specifies that extra space is required for any via with 3x3 cuts or more (that is, a cut with four or more adjacent cuts – see Figure 2-6). A cut that is within .25 μm of four other cuts requires spacing that is greater than or equal to 0.22 μm.

  LAYER CUT12 

  SPACING 0.20 ;                           #default cut spacing

  SPACING 0.22 ADJACENTCUTS 4 WITHIN 0.25 ;  

  ...

  END CUT12

• Spacing Rule Example 4
  The following spacing rule indicates that center-to-center spacing of greater than or equal to 0.30 μm is required if the center-to-center spacing to three or more cuts is less than 0.30 μm. This is equivalent to saying a cut can have only two other cuts with center-to-center spacing that is less than 0.30 μm.

  SPACING 0.30 CENTERTOCENTER ADJACENTCUTS 3 WITHIN 0.30 ;

• Spacing Rule Example 5
  Figure 2-7 illustrates the following spacing rule:

  SPACING 1.0 ;

  SPACING 1.2 ADJACENTCUTS 2 WITHIN 1.5 EXCEPTSAMEPGNET ;

  
  Figure 2-7 Except Same PG Net Rule
  
• Spacing Rule Example 6
  The following spacing rule indicates that normal cuts require 0.10 μm edge-to-edge spacing, and cuts with an area greater than or equal to 0.02 μm² require 0.12 μm edge-to-edge spacing to all other cuts:

  SPACING 1.0 ;

  SPACING 0.12 AREA 0.02 ;

• Spacing Rule Example 7
  The following spacing rule indicates cut23 cuts must be 0.20 μm from cut12 cuts unless they are exactly aligned:

  LAYER cut23 ;

  SPACING 0.20 SAMENET LAYER cut12 STACK ;

• Spacing Rule Example 8
  Figure 2-8 illustrates the following spacing rule:

  SPACING 1.0 ;

  SPACING 1.5 PARALLELOVERLAP ;

  
  Figure 2-8 Parallel Overlap Rule
  

SPACINGTABLE

Specifies spacing tables to use on the cut layer.

The SPACINGTABLE syntax is defined as follows:

SPACINGTABLE ORTHOGONAL {WITHIN cutWithin SPACING orthoSpacing}... ;]

Example 2-6 Spacing Table Orthogonal Rule

The following example shows how a spacing table orthogonal rule is defined:

SPACING 0.10                   #min spacing for all cuts

SPACINGTABLE ORTHOGONAL 

    WITHIN 0.15 SPACING 0.11 

    WITHIN 0.13 SPACING 0.13 

    WITHIN 0.11 SPACING 0.15 ;

Figure 2-9 Spacing Table Orthogonal Overlap Regions

TYPE CUT

Specifies that the layer is for contact-cuts. The layer is later referenced in vias, and in rules for generating vias.

WIDTH minWidth

Specifies the minimum width of a cut. In most technologies, this is also the only legal size of a cut.
Type: Float, specified in microns

Defining Cut Layer Properties to Create 32/28 nm and Smaller Nodes Rules

You can include cut layer properties in your LEF file to create 32/28 nm and smaller nodes rules that currently are not supported by existing LEF syntax. The properties are specified inside the LAYER CUT statements where they can be seen with other rules.

Before you can reference them, properties must be defined at the beginning of the LEF file in the PROPERTYDEFINITIONS statement, immediately before the first LAYER statement.

• Properties belong to the LAYER object and have a type of STRING.
• The property names used for these rules all start with LEF58_.

All properties use the following syntax within the LEF PROPERTYDEFINITIONS statement:

PROPERTYDEFINITIONS
LAYER propName STRING ["stringValue"] ;

END PROPERTYDEFINITIONS

The property definitions for the cut layer properties are as follows:

PROPERTYDEFINITIONS

   LAYER LEF58_TYPE STRING ;

   LAYER LEF58_ADJACENTFOURCUTS STRING ;

   LAYER LEF58_ANTENNADIFFGATEPWL STRING ;

   LAYER LEF58_ANTENNADIFFONLYAREARATIO STRING ;

   LAYER LEF58_ANTENNADIFFPROTECTORAREARATIO STRING ; 

   LAYER LEF58_ANTENNAGATEPWL

   LAYER LEF58_ANTENNAGATEPLUSDIFF

   LAYER LEF58_ARRAYSPACING STRING ;

   LAYER LEF58_BACKSIDE STRING ;

   LAYER LEF58_CUTCLASS STRING ;

   LAYER LEF58_CUTONCENTERLINE STRING ;

   LAYER LEF58_DIRECTIONALSPACING STRING ;

   LAYER LEF58_ENCLOSURE STRING ;

   LAYER LEF58_ENCLOSUREEDGE STRING ;

   LAYER LEF58_ENCLOSURETABLE STRING ;

   LAYER LEF58_ENCLOSURETOJOINT STRING ;

   LAYER LEF58_ENCLOSUREWIDTH STRING ;

   LAYER LEF58_EOLENCLOSURE STRING ;

   LAYER LEF58_EOLSPACING STRING ;

   LAYER LEF58_FORBIDDENSPACING STRING ;

   LAYER LEF58_KEEPOUTZONE STRING ;

   LAYER LEF58_MANUFACTURINGGRID STRING ;

   LAYER LEF58_MAXSPACING STRING ;

   LAYER LEF58_MINENCLOSURE STRING ;

   LAYER LEF58_NOCUTCLASS STRING ;

   LAYER LEF58_NOMETALSPACING STRING ;

   LAYER LEF58_ONEDARRAY STRING ;

   LAYER LEF58_REGION STRING ;

   LAYER LEF58_SAMEMETALALIGNEDCUTS STRING ;

   LAYER LEF58_SPACING STRING ;

   LAYER LEF58_SPACINGTABLE STRING ;

   LAYER LEF58_VIACLUSTER STRING ;

   LAYER LEF58_VIAGROUP STRING ;

   LAYER LEF58_VIAGROUPOVERRIDESPACING STRING ;

   LAYER LEF58_VIAGROUPSPACING STRING ;

   LAYER LEF58_VOLTAGESPACING STRING ;

END PROPERTYDEFINITIONS

Type Rule

A type rule can be used to further classify a cut layer.

You can create a type rule by using the following property definition:

TYPE CUT;
PROPERTY LEF58_TYPE
  "TYPE [TSV [LAYER bottomLayer topLayer]| PASSIVATION 
      | MIMCAP | HIGHR | SPECIALCUT LAYER bottomLayer topLayer]
      ;" ;

Where:

LAYER VA

   TYPE CUT ;

   PROPERTY LEF58_TYPE "TYPE MIMCAP ;" ;

END VA

Adjacent Four Cuts Rule

An adjacent four cuts rule can be used to describe a cut spacing rule for two sets of two cuts with PRL greater than zero when few other conditions are met.

You can create an adjacent four cuts rule by using the following property definition:

PROPERTY LEF58_ADJACENTFOURCUTS 
  "ADJACENTFOURCUTS cutSpacing CUTCLASS {className [TO ALL] | ALL}
     {ABOVE | BELOW}
     PARALLEL parLength WITHIN parWithin [MERGEDCUTS]
     [HORIZONTAL|VERTICAL]
     [EXCEPTDIFFMETAL [NOEXTRACUT]]
     [MINCORNER | MININNERCORNER | MAXINNERCORNER]
     [EXCEPTMAXPRL maxPrl]
     [EXCEPTMINLENGTH minLength]
     [WITHINCUT within]
     [EXCEPTOTHERWIDTHWITHCUT width]
     [METALWIDTH maxWidth]
     ;" ; 

Where:

Adjacent Four Cuts Rule Examples

Figure 2-10 Illustration of Adjacent Four Cuts Rule

Figure 2-11 Illustration of Adjacent Four Cuts Rule with EXCEPTDIFFMETAL

Figure 2-12 Illustration of Adjacent Four Cuts Rule with MERGEDCUTS

Figure 2-13 Illustration of Adjacent Four Cuts Rule with MINCORNER

Figure 2-14 Illustration of Adjacent Four Cuts Rule with MININNERCORNER

Figure 2-15 Illustration of Adjacent Four Cuts Rule with MAXINNERCORNER

Figure 2-16 Illustration of Adjacent Four Cuts Rule with EXCEPTMAXPRL

Figure 2-17 Illustration of Adjacent Four Cuts Rule with EXCEPTMINLENGTH

Figure 2-18 Illustration of Adjacent Four Cuts Rule with WITHINCUT

Figure 2-19 Illustration of Adjacent Four Cuts Rule with EXCEPTOTHERWIDTHWITHCUT

Figure 2-20 Illustration of Adjacent Four Cuts Rule with METALWIDTH

Figure 2-21 Illustration of Adjacent Four Cuts Rule with NOEXTRACUT

Antenna Diff Gate PWL Rule

The antenna diff gate PWL rule is used to specify that the antenna gate connected to the diffusion diode can be used to define a piece-wise linear (PWL) table on the given antenna model that is indexed by the real gate area, and returns an “effective gate area” interpolated from the table.

You can create an antenna diff gate PWL rule by using the following property definition:

PROPERTY LEF58_ANTENNADIFFGATEPWL
"ANTENNADIFFGATEPWL {OXIDE1 | OXIDE2 | OXIDE3 | OXIDE4 | OXIDE5 | ...
   | OXIDE32}
   ((gateArea1 effectiveGateArea1) (gateArea2 effectiveGateArea2) ... )    ;" ;

Where:

Note that if ANTENNADIFFGATEPWL is defined, the ANTENNAGATEPWL rule is applied only to the antenna gate that is not connected to the diffusion diode. If ANTENNADIFFGATEPWL is not defined, the ANTENNAGATEPWL rule is applied to all the antenna gates.

Antenna Diff Only Area Ratio Rule

The antenna diff only area rule is used to specify a diffusion-area-based antenna ratio.

You can create an antenna diff only area rule by using the following property definition:

PROPERTY LEF58_ANTENNADIFFONLYAREARATIO
  “ANTENNADIFFONLYAREARATIO {OXIDE1 | OXIDE2 | OXIDE3 | OXIDE4 
     | OXIDE5 | ... | OXIDE32}  value
   ;..." ;

Where:

Antenna Diff Protector Area Ratio Rule

The antenna diff protector area rule is used to specify a protector diffusion-area-based antenna ratio.

You can create an antenna diff protector area rule by using the following property definition:

PROPERTY LEF58_ANTENNADIFFPROTECTORAREARATIO
  “ANTENNADIFFPROTECTORAREARATIO {OXIDE1 | OXIDE2 | OXIDE3
     | OXIDE4 | OXIDE5 | ... | OXIDE32}  value
   ;..." ;

Where:

Antenna Gate PWL Rule

The antenna gate PWL rule can be used to define a PWL (piece-wise linear) table on the given antenna model that is indexed by the real gate area, and returns an “effective gate area” interpolated from the table.

You can create an antenna gate PWL rule by using the following property definition:

PROPERTY LEF58_ANTENNAGATEPWL
"ANTENNAGATEPWL {OXIDE1 | OXIDE2 | OXIDE3 | OXIDE4 | OXIDE5 | ...
   | OXIDE32}
   ((gateArea1 effectiveGateArea1) (gateArea2 effectiveGateArea2) ... )    ;" ;

Where:

Antenna Gate Plus Diffusion Rule

The antenna gate plus diffusion rule can be used to represent the protection provided by the diffusion area that is added to the gate area value in the PAR (partial antenna ratio) equation on the given antenna model, as given below, which can be considered as the “additional effective gate-area”.

PAR = {(cutFactor * cut) * diffReducePWL(diff) - (minusDiffFactor * diff)} / {gatePWL(gate) + plusDiffProtect(diff)}

You can create an antenna gate plus diffusion rule by using the following property definition:

PROPERTY LEF58_ANTENNAGATEPLUSDIFF
"ANTENNAGATEPLUSDIFF {OXIDE1 | OXIDE2 | OXIDE3 | OXIDE4 |OXIDE5 | ...
   | OXIDE32}
   {plusDiffFactor | 
   PWL ((diffArea1 plusDiffProtect1) (diffArea1 plusDiffProtect2) ...)}    ;" ; 

Where:

All the other keywords are the same as the existing LEF cut layer ANTENNAGATEPLUSDIFF syntax.

Antenna Gate Plus Diffusion Rule Examples

The following example shows a rule for layer via1:

cut_area <= 100 * (funcGate(gate_area) + funcDiff(diff_area))

funcGate = 1 for gate_area < 1, and equals 2 for gate_area >= 1

funcDiff = 10 for diff_area < 2, and equals 50 for diff_area >= 2.

Then,

100 >= cut_area / (funcGate(gate) + funcDiff(diff))

This fits the PAR formula above using gatePWL(gate) and plusDiffProtect(diff) values.

Then the LEF file will have the following:

#Max-ratio = 100 for all diff-area values because the diff-protect value is #accounted for inside the PAR equation. Note, there is no need for ANTENNAAREARATIO #which is only checked for cut with no diff connected, while ANTENNADIFFAREARATIO

#is checked for diff and no diff connected.

ANTENNAMODEL OXIDE1 ;

ANTENNADIFFAREARATIO  ( 0 100 ) ( 10000.0 100 ) ;

#This models funcGate(gate_area) above: 0 to 0.99 is 1, above 1.0 is 2

PROPERTY LEF58_ANTENNAGATEPWL OXIDE1

    "ANTENNAGATEPWL ( ( 0  1 ) ( 0.99 1 ) ( 1.0 2 ) ( 10000.0 2 ) ) ;" ;

#This models funcDiff(diff_area) above: 0 to 1.99 is 10, above 1.0 is 50

PROPERTY LEF58_ ANTENNAGATEPLUSDIFF

    "ANTENNAGATEPLUSDIFF OXIDE1

       (( 0  10 ) ( 1.99 10 ) ( 2.0 50 ) ( 10000.0 50 )) ;" ;

Array Spacing Rule

You can use array spacing rules to require extra space between cut arrays, and between each cut array inside one large via. This rule only applies to large vias with many cuts; it does not apply to cuts for smaller vias.

When a cut layer has multiple cut classes defined, at the most one ARRAYSPACING property statement can be specified per cut class.

You can create an array spacing rule by using the following property definition:

PROPERTY LEF58_ARRAYSPACING 
“ARRAYSPACING [CUTCLASS className] [PARALLELOVERLAP]
      [LONGARRAY] [WIDTH viaWidth] 
      [WITHIN within ARRAYWIDTH arrayWidth] CUTSPACING cutSpacing
      {ARRAYCUTS arrayCuts SPACING arraySpacing} ...
      ;...” ;

All other keywords are the same as the existing LEF cut layer ARRAYSPACING syntax.

Where:

CUTCLASS className

Defines the array spacing rule for a specific cut class (className). If CUTCLASS is defined in cut layer, then CUTCLASS must be specified in the ARRAYSPACING statement. Specify individual rules with the CUTCLASS keyword for each cut class, if needed.

PARALLELOVERLAP

Indicates that the array spacing rule applies only when there is a parallel edge overlap greater than 0.

WITHIN within ARRAYWIDTH arrayWidth

Indicates a specific way to check cut spacing of a via array. With WITHIN, only one ARRAYCUTS statement should be defined, and cutSpacing and arraySpacing should have the same value. Any same-net or different-net cuts within within would be considered as a via array. Then, a rectilinear bounding box of all of the cuts of the via array is formed. Any cuts completely inside a portion that has width less than or equal to arrayWidth is removed. The remaining cuts must have spacing of cutSpacing (or arraySpacing).
Type: Float, specified in microns

Array Spacing Rule Examples

• The following array spacing rule indicates that any AY_array via with a metal width greater than or equal to 1.0 μm should use cut spacing of 0.10 μm between cuts inside 3x3 cut arrays. The cut arrays should be at a distance greater than 0.30 μm from other cut arrays with a parallel edge overlap greater than 0.
  

  PROPERTY LEF58_ARRAYSPACING 

  "ARRAYSPACING CUTCLASS AY_array PARALLELOVERLAP WIDTH 1.0 CUTSPACING 0.10 ARRAYCUTS 3 SPACING 0.30 ;" ;

• The next example illustrates the following array spacing rule:
  

  PROPERTY LEF58_ARRAYSPACING  “
       ARRAYSPACING WITHIN 0.2 ARRAYWIDTH 0.06
            CUTSPACING 0.05
            ARRAYCUTS 3 SPACING 0.05 ; “ ;

  
  Figure 2-22 Illustration of Array Spacing Rule
  

Backside Rule

A backside rule can be used to specify that cut layer is used on the underside of the die.

You can create a backside rule by using the following property definition:

PROPERTY LEF58_BACKSIDE 
“BACKSIDE ;” ; 

Where:

BACKSIDE

Indicates that the cut layer is a backside cut layer. Only a regular cut layer or a passivation cut layer can be a backside layer; a TSV cut layer cannot be a backside layer.

Cut Class Rule

Cut class rules can be used to define the cut classes to which different types of vias can belong.

You can create a cut class rule by using the following property definition:

PROPERTY LEF58_CUTCLASS 
"CUTCLASS className WIDTH viaWidth [LENGTH viaLength] [CUTS numCut]
      [ORIENT {HORIZONTAL | VERTICAL}]
      ; " ;

Where:

CUTCLASS className

Specifies the name of the cut class. This name is used in later references to the cut class.

CUTS numCut

Defines the equivalent number of cuts of the cut class for calculation of resistance value. Resistance value for this cut class vias would be ( Resistance of the cut layer )/ numCut . Default: 1
Type: Integer

Figure 2-23 illustrates three via sizes. Via Vx1 contains one cut, via Vx2 contains 2 cuts, and via Vx4 contains four cuts. Using the above equation, Figure 2-23 shows how many cuts of each cut type are required to meet the listed minimum cut rule.

The resistance value is determined using the following equation:

cut layer resistance / numCut

Figure 2-23 Illustration of Via Sizes

LENGTH viaLength

Specifies the cut length for this cut class. Any vias with cut lengths of viaLength belong to this class. LENGTH is only used for rectangular rather than square cuts, and viaLength must be greater than viaWidth.
Type: Float, specified in microns

ORIENT {HORIZONTAL | VERTICAL}

Specifies that the given horizontal or vertical direction is the only legal orientation of a cut via in this cut class. This keyword should be specified only for a rectangular cut class.

WIDTH viaWidth

Specifies the cut width for this cut class. Any vias with cut widths of viaWidth belong to this class.
Type: Float, specified in microns

Cut Class Rule Examples

• The following cut class rule indicates that any cut vias with a square dimension of 0.15 μm belong to cut class VA:
  

  PROPERTY LEF58_CUTCLASS "CUTCLASS VA WIDTH 0.15 ;" ;

• The following cut class rule indicates that any cut vias with a rectangular dimension of 0.15 μm and 0.35 μm belong to cut class VB. This cut class uses 2 cuts; therefore, for a minimum cut rule requirement of two cuts, one via of this cut class is required to meet the rule. If the resistance value of a cut layer is 10 ohms, the resistance value of vias of this cut class is 1/2 x 10 = 5 ohms.
  

  PROPERTY LEF58_CUTCLASS "CUTCLASS VB WIDTH 0.15 LENGTH 0.35 CUTS 2 ;" ;

• The following cut class rule indicates that any cut vias with a square dimension of 0.20 μm belong to cut class VC. This cut class uses 4 cuts; therefore, for a minimum cut rule requirement of 4 cuts, one via of this cut class is required to meet the rule.
  

  PROPERTY LEF58_CUTCLASS "CUTCLASS VC WIDTH 0.20 CUTS 4 ;" ;

Cut On Center Line Rule

You can create a cut on center line rule to specify that the center of a via cut must be placed on the center lines of the wires on both metal layers if the wire width is less than the specified width.

You can create a cut on center line rule by using the following property definition:

PROPERTY LEF58_CUTONCENTERLINE 
  "CUTONCENTERLINE width CUTCLASS className [ABOVE | BELOW]
     [EXTRACUT cutWithin WIDTH exactWidth]
     ;..." ;

Where:

Cut On Center Line Rule Examples

• The following cut on center line rule indicates that the center of a VA via cut must be on the centerlines of the wires on both metal layers with width less than 0.13 µm:
  

  PROPERTY LEF58_CUTONCENTERLINE 

  "CUTONCENTERLINE 0.13 CUTCLASS VA ;" ;

  
  Figure 2-24 Illustration of the Cut on Center Line Rule
  

Directional Spacing Rule

You can create a directional spacing rule by using the following property definition:

PROPERTY LEF58_DIRECTIONALSPACING 
"DIRECTIONALSPACING cutSpacing {HORIZONTAL | VERTICAL}
    PRL prl
    CUTCLASS className1 TO className2
    [PARALLEL parLength WITHIN parWithin 
        [EXCLUDECUTEDGE]
        [CUTS numCuts]
        [VIAGROUP groupName]]
    ; " ;

Where:

Directional Spacing Rule Examples

• The following diagram illustrates the directional spacing rules given below:
  

  PROPERTY LEF58_VIAGROUP “

   VIAGROUP VGA CUTS 3 CUTCLASS VA 

          PRLTWOSIDES -0.01 -0.03 -0.01 -0.03 WITHIN 0.02 0.04 ; “ ;

  PROPERTY LEF58_DIRECTIONALSPACING  “

      DIRECTIONALSPACING 0.07 VERTICAL PRL -0.02

          CUTCLASS VB TO VA PARALLEL -0.04 WITHIN 0.05 ;

      DIRECTIONALSPACING 0.08 VERTICAL PRL -0.02

          CUTCLASS VB TO VA

          PARALLEL -0.04 WITHIN 0.05 VIAGROUP VGA ; “ ;

  
  Figure 2-25 Illustration of the Directional Spacing Rule
  
• The following diagram illustrates the directional spacing rule with EXCLUDECUTEDGE given below:
  

  PROPERTY LEF58_DIRECTIONALSPACING  "

      DIRECTIONALSPACING 0.15 VERTICAL PRL 0

          CUTCLASS VB TO VA PARALLEL -0.08 WITHIN 0.01 ;

          EXCLUDECUTEDGE CUTS 2 ; " ;

  
  Figure 2-26 Illustration of the Directional Spacing Rule with EXCLUDECUTEDGE
  

Enclosure Rule

An enclosure rule can be used to prohibit via cuts from sharing the same wire edge.

You can create an enclosure rule by using the following property definition:

PROPERTY LEF58_ENCLOSURE 
"ENCLOSURE [CUTCLASS className][ABOVE | BELOW]
[MINCORNER]
   {EOL eolWidth [HORIZONTAL | VERTICAL]
          [MINLENGTH minLength] [EOLONLY] 
          [SHORTEDGEONEOL] eolOverhang otherOverhang
          [SIDESPACING spacing EXTENSION backwardExt forwardExt
          |ENDSPACING spacing EXTENSION extension
          ]
   |{overhang1 overhang2
     |[OFFCENTERLINE] END overhang1 SIDE overhang2
     | HORIZONTAL overhang1 VERTICAL overhang2}
     [JOGLENGTHONLY length [INCLUDELSHAPE] ]
     [HOLLOW {HORIZONTAL|VERTICAL} length]
     [WIDTH minWidth 
        [INCLUDEABUTTED]
        [EXCEPTEXTRACUT cutWithin [PRL | NOSHAREDEDGE | EXACTPRL prl]]
     |LENGTH minLength 
     |EXTRACUT [EXTRAONLY [PRL prl]] 
     |REDUNDANTCUT cutWithin
     |PARALLEL parLength [parLength2] WITHIN parWithin [parWithin2] 
          [BELOWENCLOSURE belowEnclosure
               [ALLSIDES enclosure1 enclosure2]
          |ABOVEENCLOSURE aboveEnclosure] 
     |CONCAVECORNERS numCorner
     |OTHERWITHINWIDTH width WITHIN within
     [OTHERSIDE otherEnclosure]]
     }
     ;..." ;

Where:

All other keywords are the same as the existing LEF cut layer ENCLOSURE syntax.

Enclosure Rule Examples

• The following enclosure rule specifies that VC vias should have 0.10 μm overhang on all four sides of the routing layers:
  

  PROPERTY LEF58_ENCLOSURE 

  “ENCLOSURE CUTCLASS VC 0.10 0.10 ;” ;

• The following enclosure rule specifies that the end/short edge must have 0.05 μm overhang to a EOL edge:
  

  PROPERTY LEF58_ENCLOSURE 

  “ENCLOSURE CUTCLASS VB EOL 0.2

       SHORTEDGEONEOL 0.05 0.04 ;” ;

  
  Figure 2-27 Illustration of Enclosure Rule With SHORTEDGEONEOL
  
• The following enclosure rule illustrates JOGLENGTHONLY:
  

  ENCLOSURE 0.00 0.04 ;

  PROPERTY LEF58_ENCLOSURE “

     ENCLOSURE 0 0.03 JOGLENGTHONLY 0.1 ; “ ;

  
  Figure 2-28 Illustration of the Enclosure Rule with JOGLENGTHONLY
  
• The following enclosure rule illustrates INCLUDEABUTTED:
  

  ENCLOSURE 0.00 0.04 ;

  PROPERTY LEF58_ENCLOSURE 

       "ENCLOSURE 0.05 0.05

           WIDTH 0.2 INCLUDEABUTTED ; " ;

  
  Figure 2-29 Illustration of the Enclosure Rule with INCLUDEABUTTED
  
• Figure 2-30 illustrates the following enclosure rules:
  

  ENCLOSURE 0.0 0.05 ;             #overhang 0.0 0.05

  ENCLOSURE 0.02 0.02 ;           #or, overhang 0.02 0.02

  PROPERTY LEF58_ENCLOSURE 

  “ENCLOSURE 0.03 0.03 WIDTH 0.3 EXCEPTEXTRACUT 0.2 PRL ;” ;

  
  Figure 2-30 Illustrations of the Enclosure Rule With PRL
  
• Figure 2-31 illustrates the following enclosure rules:
  

  ENCLOSURE 0.0 0.05 ;          #overhang 0.0 0.05

  ENCLOSURE 0.01 0.04 ;         #or overhang 0.01 0.04

  PROPERTY LEF58_ENCLOSURE 

  “ENCLOSURE 0.03 0.03 WIDTH 0.3 EXCEPTEXTRACUT 0.2 ;” ;

  
  Figure 2-31 Illustration of the Enclosure Rule With ExceptExtraCut and NoSharedEdge
  
• The following enclosure rule specifies that VB rectangular cut vias should have 0.10 μm overhang on the end edges, and no overhang on the side edges on the routing layers. (See Figure 2-32 .)
  

  PROPERTY LEF58_ENCLOSURE 

  “ENCLOSURE CUTCLASS VB END 0.10 SIDE 0.000 ;” ;

  
  Figure 2-32 Illustration of the Enclosure Rule With CutClass
  
• The following enclosure rule specifies that VA vias with two or more same-metal cuts should have 0.15 μm overhang on any two opposite sides of the routing layers. (See Figure 2-33 ).
  

  PROPERTY LEF58_ENCLOSURE 

     “ENCLOSURE CUTCLASS VA 0.000 0.20 ;

      ENCLOSURE CUTCLASS VA 0.000 0.15 EXTRACUT;” ;

  
  Figure 2-33 Illustration of the Enclosure Rule With CutClass
  
• The following enclosure rule indicates that a VA cut via must at least have either 0.10 μm, 0.12 μm or 0.0 μm, or 0.20 μm enclosures. For redundant cuts having same metal shapes on both metal layers, one of the VA cuts should at least have either 0.10 μm, 0.12 μm or 0.0 μm, or 0.20 μm enclosures, and the rest of the VA cuts within 0.15 μm distance from it, should have at least 0.0 μm, 0.05 μm enclosures.
  

  PROPERTY LEF58_ENCLOSURE 

     “ENCLOSURE CUTCLASS VA 0.10 0.12 ;

      ENCLOSURE CUTCLASS VA 0 0 0.20 ;

      ENCLOSURE CUTCLASS VA 0.0 0.05 REDUNDANTCUT 0.15 ;” ;

• Figure 2-34 illustrates ENCLOSURE rule with REDUNDANTCUT:
  

  ENCLOSURE 0.03 0.03 WIDTH 0.3 ;

  PROPERTY LEF58_ENCLOSURE

     “ENCLOSURE 0.0 0.02 EXTRACUT ;

      ENCLOSURE 0.0 0.01 REDUNDANTCUT 0.1 ; ” ;

  
  Figure 2-34 Illustrations of the Enclosure Rule With REDUNDANTCUT
  
• The following enclosure rule indicates that the overhang of a via cut must be 0.15 μm on an EOL edge with length less than 0.30 μm and it's opposite side, while the overhang must be 0.05 on the other two sides. If no EOL edge is involved, a via cut should have 0.10 μm overhang on all four sides of the routing layers:
  

  ENCLOSURE 0.10 0.10 ;

  PROPERTY LEF58_ENCLOSURE

  “ENCLOSURE EOL 0.30 0.15 0.05 ; ” ;

  
  Figure 2-35 Illustration of the Enclosure Rule With Enclosure EOL
  
  Figure 2-36 Definition of SIDESPACING and ENDSPACING
  
• The following enclosure rule indicates that 0.15 μm and 0.05 μm can be the enclosure values of a cut on a EOL edge and the other sides if there is no neighbor wires within 0.04 μm with extension of 0.03 on the side edges or within 0.08 μm with extension of 0.06 on the EOL edge:
  

  ENCLOSURE 0.1 0.1 ;

  PROPERTY LEF58_ENCLOSURE

  “ENCLOSURE EOL 0.2 0.15 0.05 SIDESPACING 0.04 EXTENSION 0.03 0.03 ; 

  ENCLOSURE EOL 0.2 0.15 0.05 ENDSPACING 0.08 EXTENSION 0.06 ; ” ;

  
  Figure 2-37 Illustration of the Enclosure Rule With SIDESPACING and ENDSPACING
  
• The following enclosure rule indicates that the overhang of a via cut must be 0.15 μm on an EOL edge with length less than 0.30 μm and the opposite side while the overhang must be 0.05 μm on the other two sides. If no EOL edge is involved, a via cut should have 0.10 μm overhang on all four sides of the routing layers:
  

  PROPERTY LEF58_ENCLOSURE

  “ENCLOSURE EOL 0.30 EOLONLY 0.15 0.05 ; ” ; 

  
  Figure 2-38 Illustration of the Enclosure Rule With EOLONLY
  
• Figure 2-39 illustrates the following enclosure rules:
  

  ENCLOSURE 0.05 0.00 ;

  ENCLOSURE 0.06 0.00 WIDTH 0.1 ;

  PROPERTY LEF58_ENCLOSURE

  “ENCLOSURE 0.09 0.09 PARALLEL -0.11 WITHIN 0.08 ;” ;

  
  Figure 2-39 Illustration of the Enclosure Rule With PARALLEL and WITHIN
  
• Figure 2-40 illustrates the following enclosure rules:
  

  PROPERTY LEF58_ENCLOSURE 

       “ENCLOSURE CUTCLASS VSINGLECUT ABOVE 0.020 0.000 ; 

        ENCLOSURE CUTCLASS VSINGLECUT ABOVE 0.015 0.015 

        PARALLEL -0.08 -0.1 WITHIN 0.04  0.06 ; ” ;

  
  Figure 2-40 Illustration of the Enclosure Rule With PARALLEL and WITHIN
  

• Figure 2-41 illustrates the following enclosure rules:
  

  PROPERTY LEF58_ENCLOSURE

    “ENCLOSURE CUTCLASS VSINGLECUT ABOVE 0.020 0.000 ; 

     ENCLOSURE CUTCLASS VSINGLECUT ABOVE 0.015 0.015 

        PARALLEL -0.08 -0.1 WITHIN 0.04 0.06 

        BELOWENCLOSURE 0.05 ; ” ;

  
  Figure 2-41 Illustration of the Enclosure Rule With PARALLEL and WITHIN
  
  Figure 2-42 Illustration of the Enclosure Rule With CONCAVECORNERS
  
• The following enclosure rule illustrates MINCORNER:
  

  ENCLOSURE 0.00 0.04 ;

  PROPERTY LEF58_ENCLOSURE “

       ENCLOSURE MINCORNER 0.05 0.1 ; ” ;

  
  Figure 2-43 Illustration of the Enclosure Rule With MINCORNER
  
• The following diagram illustrates use of ALLSIDES:
  Figure 2-44 Illustration of the Enclosure Rule With ALLSIDES in BELOWENCLOSURE
  
• The following diagram illustrates the enclosure rule with HOLLOW given below:
  

  ENCLOSURE 0.00 0.04 ;

  PROPERTY LEF58_ENCLOSURE “

       ENCLOSURE BELOW 0 0.03 HOLLOW HORIZONTAL 0.02 ; ” ;

  
  Figure 2-45 Illustration of the Enclosure Rule With HOLLOW
  
• The following diagram illustrates an enclosure rule with OTHERWITHINWIDTH:
  Figure 2-46 Illustration of the Enclosure Rule with OTHERWITHINWIDTH
  
• The following diagram illustrates an enclosure rule with OTHERSIDE:
  Figure 2-47 Illustration of Enclosure Rule with OTHERSIDE
  

Enclosure Edge Rule

You can create a specific cut-edge enclosure rule that does not fit the normal enclosure rule semantics by using the following property definition:

PROPERTY LEF58_ENCLOSUREEDGE 
"ENCLOSUREEDGE [CUTCLASS className] [ABOVE | BELOW] overhang 
     {OPPOSITE 
          {[EXCEPTEOL eolWidth] [NOCONCAVECORNER within]
               [CUTTOBELOWSPACING spacing
                  [ABOVEMETAL extension]]
          | WRONGDIRECTION 
          }
     |[INCLUDECORNER]
      {WIDTH [BOTHWIRE] minWidth [maxWidth]
      | SPANLENGTH minSpanLength [maxSpanLength]}
           PARALLEL parLength
           {WITHIN parWithin | WITHIN minWithin maxWithin} 
           [EXCEPTEXTRACUT [cutWithin]]
           [EXCEPTTWOEDGES [exceptWithin]]
     |CONVEXCORNERS convexLength adjacentLength
           PARALLEL parWithin LENGTH length 
     }
  ;]..." ;

Where:

All other keywords are the same as the existing LEF cut layer ENCLOSUREEDGE syntax.

Enclosure Edge Rule Examples

• Figure 2-48 illustrates enclosure edge rule with NOCONCAVECORNER and CUTTOBELOWSPACING:
  

  PROPERTY LEF58_ENCLOSUREEDGE

  "ENCLOSUREEDGE ABOVE 0.02 OPPOSITE

        NOCONCAVECORNER 0.05 

        CUTTOBELOWSPACING  0.07 ; " ;

  
  Figure 2-48 Illustration of Enclosure Edge Rules
  
• The following figure illustrates enclosure edge rule with ABOVEMETAL:
  

  PROPERTY LEF58_ENCLOSUREEDGE

  "ENCLOSUREEDGE ABOVE 0.02 OPPOSITE

        CUTTOBELOWSPACING  0.07 

        ABOVEMETAL 0.03 ; " ;

  
  Figure 2-49 Illustration of Enclosure Edge Rules
  
• Figure 2-50 illustrates the following enclosure edge rule:
  

  ENCLOSURE 0.0 0.05 ;          #normal enclosure rule

  PROPERTY LEF58_ENCLOSUREEDGE 

  "ENCLOSUREEDGE 0.02 WIDTH 0.2 PARALLEL 0.25 WITHIN 0.11 ;" ;

  
  Figure 2-50 Illustration of Enclosure Edge Rules
  
• Figure 2-51 illustrates the following enclosure edge rule:
  

  PROPERTY LEF58_ENCLOSUREEDGE 

  "ENCLOSUREEDGE 0.05 WIDTH 0.20 

      PARALLEL 0.50 WITHIN 0.08 0.10 

      EXCEPTTWOEDGES 0.12 ; " ;

  
  Figure 2-51 Illustration of the Enclosure Edge Rule with EXCEPTTWOEDGES
  
• Figure 2-52 illustrates the following enclosure edge rule:
  

  PROPERTY LEF58_ENCLOSUREEDGE 

  "ENCLOSUREEDGE 0.05 WIDTH 0.20

   PARALLEL 0.50 WITHIN 0.10 EXCEPTTWOEDGES ;" ;

  
  Figure 2-52 Illustration of Enclosure Edge Rules
  
• Figure 2-53 illustrates the following enclosure edge rule:
  

  PROPERTY LEF58_ENCLOSUREEDGE 

  "ENCLOSUREEDGE 0.05 INCLUDECORNER 

       WIDTH BOTHWIRE 0.20 

       PARALLEL 0.5 WITHIN 0.10 ; " ;

  
  Figure 2-53 Illustration of the Enclosure Edge Rule with BOTHWIRE and INCLUDECORNER
  
  Figure 2-54 Illustration of the Enclosure Edge Rule with OPPOSITE and EXCEPTEOL
  
  Figure 2-55 Illustration of the Enclosure Edge Rule with SPANLENGTH
  
  Figure 2-56 Illustration of the Enclosure Edge Rule with CONVEXCORNERS
  
  Figure 2-57 Illustration of the Enclosure Edge Rule with WRONGDIRECTION
  

Enclosure Table Rule

You can create an enclosure table rule to specify the enclosure requirement based on the wire width in a table format by using the following property definition:

PROPERTY LEF58_ENCLOSURETABLE 
"ENCLOSURETABLE [CUTCLASS className] [MASK maskNum]
[OTHERMASK otherMaskNum]
         [USEMAXWIDTH | USEMINWIDTH | WITHINFIRSTWIDTH]
     [DEFAULT {[ABOVE | BELOW] 
        overhang1 overhang2 overhang3 overhang4}...]
     {WIDTH width {[ABOVE | BELOW] 
        overhang1 overhang2 overhang3 overhang4 [MINSUM]
        [MUSTUSE]
        [MAXLENGTH length | LENGTH length]
        [LAYER trimLayer OVERLAP {1|2}
              [TRIMLENGTHOUTERMETAL trimLength]
        | OTHERWITHINWIDTH width [LAYER layerName]
              WITHIN within 
              [OTHERSIDE otherEnclosure]]
        | LINEENDGAPONLY
        | ROWBOUNDARY within OTHERSIDE otherEnclosure]
        [EXACTZERO]
        [INCLUDEABUTTED]}...
     | OTHERWIDTH otherWidth [PARALLEL parLength WITHIN parWithin]
           {{ABOVE| BELOW}
        overhang1 overhang2 overhang3 overhang4 [MINSUM]}...}...
     ; " ;

Where:

All the other keywords are the same as the existing LEF cut layer ENCLOSURETABLE syntax.

PROPERTY LEF58_ENCLOSURETABLE "
ENCLOSURETABLE
   WIDTH 0.0 0.0 0.0 0.030 0.030 EXACTZERO 
        0.015 0.015 0.015 0.015 ; " ;

PROPERTY LEF58_ENCLOSURETABLE " 
    ENCLOSURETABLE CUTCLASS VA
       WIDTH 0.00000 BELOW 0.090 0.090 0.000 0.000
       WIDTH 0.00000 BELOW 0.120 0.120 0.000 0.000
          MUSTUSE LENGTH 0.5 
       WIDTH 0.00000 BELOW 0.060 0.060 0.000 0.000 
          OTHERWITHINWIDTH 0.039 WITHIN 0.008 
       ... ; " ;

Enclosure Table Rule Examples

• The following enclosure table rule indicates that:
  • For a cut in a wire of any width, 0.01 µm on two opposite sides and 0.02 µm on the other two opposite sides can be an overhang choice.
  • For a via cut in a wire with width greater than 0.1 µm and less than or equal to 0.2 µm, 0.015 µm overhang on four sides can be applied.
  • For a via cut in a wire with width greater than 0.2 µm and less than or equal to 0.3 µm, 0.015 µm and 0.016 µm overhangs on two opposite sides, and 0.017 µm and 0.018 µm overhangs on the other two opposite sides, or 0.025 µm and 0.03 µm or 0.026 µm and 0.029 µm or 0.027 µm and 0.28 µm on two opposite sides, 0.00 µm on the other two opposite sides can be applied.
  • For a via cut in a wire with width greater than 0.3 µm, 0.019 µm overhang on four sides can be applied.
  
  

  PROPERTY LEF58_ENCLOSURETABLE

  "ENCLOSURETABLE

  DEFAULT 0.01 0.01 0.02 0.02

  WIDTH 0.1 0.015 0.015 0.015 0.015

  WIDTH 0.2 0.015 0.016 0.017 0.018

           0.025 0.03 0.00 0.00 MINSUM

  WIDTH 0.3 0.019 0.019 0.019 0.019 ; " ;

• The following diagram illustrates the enclosure table rule given below:
  

  PROPERTY LEF58_ENCLOSURETABLE

        "ENCLOSURETABLE

             WIDTH 0.3 0.05 0.05 0.08 0.1; " ;

  
  Figure 2-58 Illustration of Enclosure Table Rules
  
• The following rule indicates that for a via cut in a wire with width > 0.1 µm, 0.015 overhang on four sides can be applied, for a via cut in a wire with width on the above metal layer > 0.2 µm, 0.019 overhang on the below metal layer on four sides can be applied.
  

  PROPERTY LEF58_ENCLOSURETABLE

  "ENCLOSURETABLE

  WIDTH 0.1 0.015 0.015 0.015 0.015

  OTHERWIDTH 0.2 BELOW 0.019 0.019 0.019 0.019 ; " ;

  
  Figure 2-59 Illustration of Enclosure Table Rules with OTHERWIDTH
  
• The following diagram illustrates an enclosure table rule with OTHERWIDTH:
  Figure 2-60 Illustration of Enclosure Table Rules with OTHERWIDTH
  
• The following diagram illustrates an enclosure table rule with WITHINFIRSTWIDTH:
  

  PROPERTY LEF58_ENCLOSURETABLE 

   "ENCLOSURETABLE WITHINFIRSTWIDTH

            WIDTH 0.000 0.020 0.015 0.000 0.000

            WIDTH 0.024 0.020 0.015 0.001 0.001; " ;

  
  Figure 2-61 Illustration of Enclosure Table Rule with WITHINFIRSTWIDTH
  
• The following diagram illustrates the enclosure table rule given below:
  

  PROPERTY LEF58_ENCLOSURETABLE 

  "ENCLOSURETABLE

      WIDTH 0.0 BELOW 0.0 0.0 0.015 0.015

          BELOW 0.0 0.0 0.012 0.012 MAXLENGTH 0.05 ; " ;

  
  Figure 2-62 Illustration of Enclosure Table Rules
  
• The following diagram illustrates the enclosure table rule with LAYER given below:
  

  PROPERTY LEF58_ENCLOSURETABLE 

  "ENCLOSURETABLE

       WIDTH 0.0 BELOW 0.02 0.02 0.0 0.0

       WIDTH 0.0 BELOW 0.01 0.01 0.0 0.0

            LAYER TRIM1 OVERLAP 1 ; " ;

  
  Figure 2-63 Illustration of Enclosure Table Rules with LAYER
  
• The following diagram illustrates the enclosure table rule with LAYER given below:
  

  PROPERTY LEF58_ENCLOSURETABLE 
  "ENCLOSURETABLE
       WIDTH 0.0 BELOW 0.02 0.02 0.0 0.0
       WIDTH 0.0 BELOW 0.01 0.01 0.0 0.0
            LAYER TRIM1 OVERLAP 2 ; " ;

  
  Figure 2-64 Illustration of Enclosure Table Rules with LAYER
  
• The following diagram depicts an enclosure table rule with TRIMLENGTHOUTERMETAL:
  

  PROPERTY LEF58_ENCLOSURETABLE 
  "ENCLOSURETABLE
      WIDTH 0.0 BELOW 0.01 0.01 0.0 0.0
      WIDTH 0.0 BELOW 0.02 0.02 0.0 0.0
          LAYER TRIM1 OVERLAP 1 
          TRIMLENGTHOUTERMETAL 0.08 ; " ;

  
  Figure 2-65 Illustration of Enclosure Table Rules with TRIMLENGTHOUTERMETAL
  
• The following diagram illustrates an enclosure table rule with OTHERMASK:
  

  PROPERTY LEF58_ENCLOSURETABLE 
  "ENCLOSURETABLE OTHERMASK 1
      WIDTH 0.1 BELOW 0.015 0.015 0.015 0.015
      OTHERWIDTH 0.2 BELOW 0.019 0.019 0.019 0.019 ; " ;

  
  Figure 2-66 Illustration of Enclosure Table Rules with OTHERMASK
  
  Figure 2-67 Illustration of Enclosure Table Rule with BELOW OTHERWITHINWIDTH
  
  Figure 2-68 Illustration of Enclosure Table Rule with ABOVE OTHERWITHINWIDTH
  
• The following diagram illustrates an enclosure table rule with LINEENDGAPONLY:
  

  PROPERTY LEF58_ENCLOSURETABLE 
    “ ENCLOSURETABLE
         WIDTH 0.1 BELOW 0.02 0.02 0.10 0.10 LINEENDGAPONLY
         WIDTH 0.1 BELOW 0.05 0.05 0.10 0.10 ; " ;

  
  On below metal layer,

  PROPERTY LEF58_LINEENDGAP “

   LINEENDGAP 0.03 WIDTH 0.12 MASK 1 ; “ ;

  
  Figure 2-69 Illustration of Enclosure Table Rule with LINEENDGAPONLY
  
  Figure 2-70 Illustration of Enclosure Table Rule with ROWBOUNDARY
  

Enclosure Width Rule

You can create a specific cut-width enclosure rule that does not fit the normal enclosure rule semantics by using the following property definition:

PROPERTY LEF58_ENCLOSUREWIDTH 
"ENCLOSUREWIDTH {VIAOVERLAPONLY | USEMINWIDTH} 
     ; " ;

Where:

Enclosure Width Rule Examples

Figure 2-71 Illustration of Enclosure Width Rules

Enclosure Joint Rule

You can create enclosure joint rule to specify the overhang between a non-redundant cut to two consecutive joints in either above or both above and below routing layer.

You can create a enclosure joint rule by using the following property definition:

PROPERTY LEF58_ENCLOSURETOJOINT 
"ENCLOSURETOJOINT [CUTCLASS className] [ABOVE | BELOW]
       toOneJointOverhang [toBothJointOverhang]
       [EOLMINLENGTH minLength]
       JOINTWIDTH jointWidth JOINTLENGTH spanLength
       ; " ;

Where:

Enclosure Joint Rule Examples

Figure 2-72 Illustration of Enclosure Joint Rule

EOL Enclosure Rule

You can create EOL enclosure rule to specify the enclosure requirement on a EOL edge with width less than the specified EOL width.

You can create a EOL enclosure rule by using the following property definition:

PROPERTY LEF58_EOLENCLOSURE
"EOLENCLOSURE eolWidth [MINEOLWIDTH minEolWidth]
    [HORIZONTAL | VERTICAL]
    [EQUALRECTWIDTH] [CUTCLASS className] [ABOVE | BELOW]
    {{LONGEDGEONLY | SHORTEDGEONLY} overhang 
    | overhang 
        [exactOverhang
        | PARALLELEDGE parSpace EXTENSION backwardExt forwardExt
              [MINLENGTH minLength]
        | MINLENGTH minLength
        | ALLSIDES
        ]
    }
    ; " ;

Where:

All other keywords are the same as the existing LEF cut layer EOLENCLOSURE syntax.

EOL Enclosure Rule Examples

Figure 2-73 Illustration of EOL Enclosure Rule

Figure 2-74 Illustration of EOL Enclosure Rule with EQUALRECTWIDTH

Figure 2-75 Illustration of EOL Enclosure Rule with PARALLELEDGE and EXTENSION

Figure 2-76 Illustration of EOL Enclosure Rule with MINEOLWIDTH

EOL Spacing Rule

You can create EOL spacing rule to specify the cut spacing on certain edges of a cut on a EOL edge above routing layer with width less than the specified EOL width.

You can create a EOL spacing rule by using the following property definition:

PROPERTY LEF58_EOLSPACING
"EOLSPACING cutSpacing1 cutSpacing2
    [CUTCLASS className1 [{TO className2 cutSpacing1 cutSpacing2}...]] 
    ENDWIDTH eolWidth PRL prl
    ENCLOSURE smallerOverhang equalOverhang
    EXTENSION sideExt backwardExt SPANLENGTH spanLength
    ; " ;

Where:

EOL Spacing Rule Examples

Figure 2-77 Illustration of EOLSPACING Rule

Forbidden Spacing Rule

You can create a forbidden spacing rule to specify forbidden spacing between two cuts.

You can create a forbidden spacing rule by using the following property definition:

PROPERTY LEF58_FORBIDDENSPACING
"FORBIDDENSPACING CUTCLASS className minSpacing maxSpacing 
    [SAMEMASK]
    [SHORTEDGEONLY | LONGEDGEONLY | HORIZONTAL | VERTICAL]
    [PRL {prl TO prlClassName}...]
    ; " ;

Where:

Forbidden Spacing Rule Examples

• The following forbidden spacing table rule illustrates forbidden spacing between two VB cuts:
  

  PROPERTY LEF58_FORBIDDENSPACING

     "FORBIDDENSPACING CUTCLASS VB 0.07 0.09 

       SHORTEDGEONLY ; " ;

  
  Figure 2-78 Illustration of Forbidden Spacing Rule
  
  Figure 2-79 Illustration of Forbidden Spacing Rule
  

Keep-out Zone Rule

The keep-out zone rule can be used to demarcate a cut spacing zone in which cuts of other classes cannot overlap.

You can create a keep-out zone rule by using the following property definition:

PROPERTY LEF58_KEEPOUTZONE
"KEEPOUTZONE CUTCLASS className1 [TO className2]
     [SAMEMASK] [SAMEMETAL | DIFFMETAL]
     [EXCEPTEXACTALIGNED [SIDE | END] spacing]
     {EXTENSION sideExtension forwardExtension | 
     ENDEXTENSION endSideExtension endForwardExtension 
     SIDEEXTENSION sideSideExtension sideForwardExtension |
     HORIZONTALEXTENSION horzSideExtension horzForwardExtension
     VERTICALEXTENSION vertSideExtension vertForwardExtension}
     SPIRALEXTENSION extension [CORNERONLY]
     ;" ; 

Where:

Keep-out Zone Rule Examples

• The following example illustrates the keep-out zone rule:

KEEPOUTZONE CUTCLASS VB TO VA 
   ENDEXTENSION endSideExtension endForwardExtension 
   SIDEEXTENSION sideSideExtension sideForwardExtension
   SPIRIALEXTENSION extension

Figure 2-80 Illustration of the Keep-out Zone Rule

• The following example illustrates the keep-out zone rule with CORNERONLY:

KEEPOUTZONE CUTCLASS VB TO VA 
   ENDEXTENSION endSideExtension endForwardExtension 
   SIDEEXTENSION sideSideExtension sideForwardExtension
   SPIRIALEXTENSION extension CORNERONLY

Figure 2-81 Illustration of the Keep-out Zone Rule with CORNERONLY

• The following example illustrates the keep-out zone rule with HORIZONTALEXTENSION and VERTICALEXTENSION:

KEEPOUTZONE CUTCLASS VA TO VA 
   HORIZONTALEXTENSION horzSideExtension horzForwardExtension
   VERTICALEXTENSION vertSideExtension vertForwardExtension
   SPIRIALEXTENSION extension

Figure 2-82 Illustration of the Keep-out Zone Rule with HORIZONTALEXTENSION and VERTICALEXTENSION

Manufacturing Grid Rule

You can create a manufacturing grid rule to specify the manufacturing grid on a given layer to override the library manufacturing grid value.

You can create a manufacturing grid rule by using the following property definition:

PROPERTY LEF58_MANUFACTURINGGRID 
"MANUFACTURINGGRID value
; " ;

Where:

Maximum Spacing Rule

You can create a maximum spacing rule to specify the maximum spacing between any two cuts.

You can create a maximum spacing rule by using the following property definition:

PROPERTY LEF58_MAXSPACING
"MAXSPACING spacing [CUTCLASS className]
;" ;

Where:

Minimum Enclosure Rule

You can create a minimum enclosure rule to specify the minimum enclosure requirements for cuts on the given cut class. These requirements are typically applied on cell objects.

You can create a maximum spacing rule by using the following property definition:

PROPERTY LEF58_MINENCLOSURE
"MINENCLOSURE CUTCLASS className [ABOVE | BELOW]
   overhang1 overhang2
   ; " ;

Where:

No Cut Class Rule

You can create a no cut class rule to specify that a given cut class cannot be used on a layer.

You can create a no cut class rule by using the following property definition:

PROPERTY LEF58_NOCUTCLASS
"NOCUTCLASS className [EXCEPTMULTICUTS]
; " ;

Where:

No Metal Spacing Rule

You can create a no metal spacing rule by using the following property definition:

PROPERTY LEF58_NOMETALSPACING
"NOMETALSPACING spacing BOTHSPACING bothSpacing [PRL prl]
      [SAMEMASK] [CUTCLASS className] 
      NEIGHBORMETAL metalPrl metalWithin 
        noMetalPrl {noMetalWithin | noMetalLowWithin noMetalHighWithin}
      [SAMESIDE]
      [ABOVE | BELOW] [EXCEPTLINEENDSPACING lineEndSpacing]
      ;" ;

Where: