4 DRD Constraints Support

This chapter contains the following topics:

Supported Constraints

The tables in this section list the constraints supported by DRD. Note the following points:

Batch-Check mode for supported constraints is available only in VLS EXL.
Limited support is available for the 'or operator in DRD editing; it is used mainly to combine constraints of the type extension.

Supported Constraints and Parameters

Category	Constraint Name (ASCII Syntax)	Tier Level Support	Support Type
Antenna	antennaRatio	L, XL, GXL, and EXL	notify/post-edit/batch-check
Antenna	cumPerLayerAntennaRatio	L, XL, GXL, and EXL	notify/post-edit/batch-check
Area	minArea	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minAreaEdgeLength	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minHoleArea	L (scalar) XL, GXL, EXL (scalar and table)	notify/post-edit/batch-check
	minIsolatedArea	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minPerimeter	L, XL, GXL, and EXL	post-edit/batch-check
	minRectArea	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minSize	L, XL, GXL, and EXL	notify/post-edit/batch-check
Complex Spacing	endOfLineKeepout	XL, GXL, and EXL	notify/post-edit/batch-check
	minEndOfLineCutSpacing	XL, GXL, and EXL	post-edit/batch-check
	minEndOfLineExtensionSpacing	L, XL, GXL, and EXL	post-edit/batch-check
	minEndofLinePerpSpacing	L, XL, GXL, and EXL	post-edit/batch-check
	minEndOfLineSpacing	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minExtensionSpacing	XL, GXL, and EXL	notify/post-edit/batch-check
	minInnerVertexSpacing	L, XL, GXL, and EXL	notify/post-edit/batch-check
	sameMetalAlignedCuts	L, XL, GXL, and EXL	notify/post-edit/batch-check
	shapeRequiredSpacing	XL, GXL, and EXL	post-edit/batch-check
Density	maxDensity	XL, GXL, and EXL	batch-check
	maxDiffDensity	XL, GXL, and EXL	batch-check
	minDensity	XL, GXL, and EXL	batch-check
Edge Length	maxDiagonalEdgeLength	L, XL, GXL, and EXL	notify/post-edit/batch-check
	maxNumMinEdges	L, XL, GXL, and EXL	post-edit/batch-check
	minDiagonalEdgeLength	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minEdgeAdjacentDistance `minEdgeAdjacentDistance` is only meant for `edgeCount` param 2. It does not support `edgeCount > 2`.	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minEdgeAdjacentLength	L, XL, GXL, and EXL	post-edit/batch-check
	minEndOfLineAdjacentToStep	XL, GXL, and EXL	post-edit/batch-check
	minInsideCornerEdgeLength	L, XL, GXL, and EXL	post-edit/batch-check
	minOutsideCornerEdgeLength	L, XL, GXL, and EXL	post-edit/batch-check
	minPerimeter	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minStepEdgeLength	L, XL, GXL, and EXL	notify/post-edit/batch-check
Extension	maxExtension	L, XL, GXL, and EXL	post-edit/batch-check
	minCenterlineExtension	XL, GXL, and EXL	post-edit/batch-check
	minEndOfLineEdgeExtension	L, XL, GXL, and EXL	post-edit/batch-check
	minEndOfLineExtension	L, XL, GXL, and EXL	post-edit/batch-check
	minExtensionDistance	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minExtensionEdge	L, XL, GXL, and EXL	post-edit/batch-check
	minInsideCornerExtension	L, XL, GXL, and EXL	post-edit/batch-check
	minInsideCornerOverlap	L, XL, GXL, and EXL	post-edit/batch-check
	minOppEndOfLineExtension	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minOppExtension	L (scalar) XL, GXL, and EXL (scalar and table)	notify/post-edit/batch-check
	minOverlapDistance Minimum overlap is derived from `minExtension`.	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minPRBoundaryExtension	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minQuadrupleExtension	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minSideExtension This rule is applicable to middle-of-line (MOL) layers, and is not intended for use with cut layers.	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minViaExtension	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minViaJointExtension	L, XL, GXL, and EXL	notify/post-edit/batch-check
Length	allowedSpanLengthRanges	L, XL, GXL, and EXL	notify/post-edit/batch-check
	maxDiffusionLength	L, XL, GXL, and EXL	notify/post-edit//batch-check
	maxLength Applies only to rectangular shapes. Non-rectangular shapes are not flagged as violations and are ignored.	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minLength Applies only to rectangular shapes. Non-rectangular shapes are not flagged as violations and are ignored.	L, XL, GXL, and EXL	notify/post-edit/batch-check
Misc	errorLayer	L, XL, GXL, and EXL	notify/post-edit/batch-check
NumCut	minNumCut	L, XL, GXL, and EXL	post-edit/batch-check
NumCut	minProtrusionNumCut	L, XL, GXL, and EXL	post-edit/batch-check
Orientation	diagonalShapesAllowed	L, XL, GXL, and EXL	notify/post-edit/batch-check
Orientation	rectShapeDir	L, XL, GXL, and EXL	notify/post-edit/batch-check
Spacing	allowedSpacingRanges (One layer)	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minCenterToCenterSpacing	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minCutClassSpacing (One layer)	L, XL, GXL, and EXL	enforce/notify/post-edit/batch-check
	minCutClassSpacing (Two layers)	L, XL, GXL, and EXL	enforce/notify/post-edit/batch-check
	minCutRoutingSpacing (Two layers)	L, XL, GXL, and EXL	enforce/notify/post-edit/batch-check
	minDiagonalSpacing	L (scalar), XL (scalar), GXL (scalar), and EXL (scalar)	notify/post-edit/batch-check
	minEndOfLineToConcaveCornerSpacing	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minEndOfNotchSpacing	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minFillToFillSpacing	L, XL, GXL, and EXL	post-edit/batch-check
	minFillToShapeSpacing	L, XL, GXL, and EXL	post-edit/batch-check
	minInfluenceSpacing	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minNotchSpacing	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minParallelViaSpacing (One layer)	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minParallelViaSpacing (Two layers plus metal)	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minParallelWithinViaSpacing	XL, GXL, and EXL	post-edit/batch-check
	minPRBoundaryInteriorHalo	L, XL, GXL, and EXL	enforce/notify/post-edit/batch-check
	minSameMetalSharedEdgeViaSpacing	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minSameNetSpacing (One layer)	L, XL, GXL, and EXL	enforce/notify/post-edit/batch-check
	minSameNetSpacing (Two layers) `minSameNetSpacing` is derived from `minSpacing` in VLS XL, GXL, and EXL.	L, XL, GXL, and EXL	enforce/notify/post-edit/batch-check
	minSpacing (One layer)	L, XL, GXL, and EXL	enforce/notify/post-edit/batch-check
	minSpacing (Two layers) (width and parallel run lengths) Parallel run length (PRL) checking between an orthogonal and diagonal shape is not supported. Therefore, checker uses the maximum value from the spacing table for checking `minSpacing`.	L, XL, GXL, and EXL	enforce/notify/post-edit/batch-check
	minSpacingOver	L, XL, GXL, and EXL	post-edit/batch-check
	minViaSpacing (One layer)	L, XL, GXL, and EXL	enforce/notify/post-edit/batch-check
	minViaSpacing (Two layers)	L, XL, GXL, and EXL	enforce/notify/post-edit/batch-check
	minVoltageSpacing (One layer)	XL, GXL, and EXL	enforce/notify/post-edit/batch-check
	minVoltageSpacing (Two layers)	XL, GXL, and EXL	enforce/notify/post-edit/batch-check
	viaSpacing	L, XL, GXL, and EXL	notify/post-edit/batch-check
Via	definedCutClassesOnly	L, XL, GXL, and EXL	notify/post-edit/batch-check
	largeRectViaArrayAllowed	L, XL, GXL, and EXL	post-edit/batch-check
	minLargeNeighborViaArrayCutSpacing	L, XL, GXL, and EXL	post-edit
	minLargeViaArrayCutSpacing	L, XL, GXL, and EXL	post-edit/batch-check
	minLargeViaArraySpacing	L, XL, GXL, and EXL	post-edit/batch-check
	minLargeViaArrayWidth	L, XL, GXL, and EXL	post-edit/batch-check
	minNeighborViaSpacing	L, XL, GXL, and EXL	post-edit/batch-check
	minOrthogonalViaSpacing	L, XL, GXL, and EXL	post-edit/batch-check
	redundantViaSetback	L, XL, GXL, and EXL	post-edit/batch-check
	stackable	L, XL, GXL, and EXL	post-edit/batch-check
	viaStackingLimits	L, XL, GXL, and EXL	post-edit/batch-check
Width	allowedWidthRanges	L, XL, GXL, and EXL	notify/post-edit/batch-check
	maxWidth	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minCornerToCornerDistance	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minDiagonalWidth	L, XL, GXL, and EXL	notify/post-edit/batch-check
	minWidth	L, XL, GXL, and EXL	notify/post-edit/batch-check
	protrusionWidth	L, XL, GXL, and EXL	post-edit/batch-check

Supported Constraints and Parameters (Virtuoso Layout Suite EXL)

Requires the Virtuoso Advanced Node Option for Layout (95511) and Virtuoso Layout Suite EXL (95800) licenses.

Category	Constraint Name (ASCII Syntax)	Tier Level Support	Support Type
Complex Spacing	endOfLineKeepout Parameters: `horizontal`, `vertical`, `eolSpacingRange`, `otherEolSpacingRange`, `jointAsEol`, `checkOtherWidth`, `equalRectWidth`	XL and EXL	notify/post-edit/batch-check
	minClusterSpacing (One layer) Parameters: `enclosingLayer`, `viaEdgeType`	XL and EXL	notify/post-edit/batch-check
	overlapViaGroup	XL and EXL	notify/post-edit/batch-check
	viaGroup Parameters: `allowBend`	XL and EXL	notify/post-edit/batch-check
Extension	minEndOfLineEdgeExtension Parameters: `minVoltage`, `maxVoltage`	XL and EXL	notify/post-edit/batch-check
	minOppExtension Parameters: `widthHorizontal \| widthVertical`	XL and EXL	notify/post-edit/batch-check
	minQuadrupleExtension Parameters: `lineEndGapOnlyTable`	XL and EXL	notify/post-edit/batch-check
Length	minStepEdgeLength Parameters: `adjEolSpacingRange`, `jogEdge`, `adjJogEdge`, `adjNotchEdge`	XL and EXL	notify/post-edit/batch-check
Spacing	mergedViaCornerToCornerSpacing Parameters: `mergeSpacing`, `lengthRange`, `otherLengthRange`, `tripletCenterViaSpacingX`, `tripletCenterViaSpacingY`, `tripletCenterViaLarger`, `maxNeighbors`, `neighborSpacing`	XL and EXL	notify/batch-check
	minCutRoutingSpacing (Two layers) Parameters: `toDiffConcaveCorner`	XL and EXL	notify/batch-check
	minParallelWithinViaSpacing Parameters: `otherWidth`	XL and EXL	notify/post-edit/batch-check
	minPRBoundaryInteriorHalo Parameters: `exceptLayer`, `exceptWidth`	XL and EXL	notify/post-edit/batch-check
	minSideSpacing (One layer) Parameters: `otherLayer`, `cutClass`, `cutWithin`	XL and EXL	notify/post-edit/batch-check
	minViaSpacing (One layer) Parameters: `otherCutClass`, `otherViaEdgeType`, `deltaVoltage`, `exceptGap`, `exceptSameMetalOverlap`, `orthogonalEnclosingMetal`, `fixedCutClassList`, `otherFixedCutClassList`, `horizontalSpacingRange`, `verticalSpacingRange`, `farEnds`	XL and EXL	notify/post-edit/batch-check
	minViaSpacing (Two layers) Parameters: `deltaVoltage`	XL and EXL	notify/post-edit/batch-check
	requiredEndOfLineShape	XL and EXL	notify/post-edit/batch-check
Width	allowedWidthRanges Parameters: `exceptOverlap`	XL and EXL	notify/post-edit/batch-check
Width	minCornerToCornerDistance Parameters: `extensionLength`, `oppositeDirection`	XL and EXL	notify/post-edit/batch-check

Supported Constraints and Parameters (Virtuoso Advanced Node for Layout Standard)

Requires Virtuoso Advanced Node Option for Layout Standard (95512) license.

Category	Constraint Name (ASCII Syntax)	Tier Level Support	Support Type
Area	minArea Parameters: `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`	XL and EXL	notify/post-edit/batch-check
Complex Spacing	forbiddenCutClassSpacingRange	XL and EXL	notify/post-edit/batch-check
	forbiddenEdgePitchRange	XL and EXL	notify/post-edit/batch-check
	forbiddenProximitySpacing	XL and EXL	notify/post-edit/batch-check
	minClusterSpacing (One layer)	XL and EXL	notify/post-edit/batch-check
	minClusterSpacing (Two layers)	XL and EXL	post-edit/batch-check
	minCornerSpacing (One layer)	XL and EXL	notify/post-edit/batch-check
	minCornerSpacing (Two layers)	XL and EXL	notify/post-edit/batch-check
	minEdgeLengthSpacing	XL and EXL	notify/post-edit/batch-check
	minEndOfLineExtensionSpacing Parameters: `sameMask`, `negativePRL`	XL and EXL	post-edit/batch-check
	minEndOfLineSpacing Parameters: `exceptEolWidth`, `exceptExactAligned`, `sameMask`, `diffMask`	XL and EXL	notify/post-edit/batch-check
	minSpanLengthSpacing	XL and EXL	enforce/notify/post-edit/batch-check
	shapeRequiredBetweenSpacing	XL and EXL	notify/post-edit/batch-check
Edge Length	minEndOfLineAdjacentToStep Parameters: `adjacentLength`, `concaveCorner`	XL and EXL	post-edit/batch-check
Edge Length	minStepEdgeLength Parameters: `any`, `horizontalEdge`, `verticalEdge`, `allCorner`, `concaveCorner`, `convexCorner`, `mixedCorner`, `exceptExactLength`, `exceptExactBothLength`	XL and EXL	notify/post-edit/batch-check
Extension	minDirectionalOverlap	XL and EXL	notify/post-edit/batch-check
Extension	minEndOfLineEdgeExtension Parameter: `shortEdgeOnly`	XL and EXL	post-edit/batch-check
	minExtensionDistance Parameters: `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`	XL and EXL	notify/post-edit/batch-check
	minExtensionEdge Parameters: `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`	XL and EXL	post-edit/batch-check
	minExtensionOnLongSide	XL and EXL	notify/post-edit/batch-check
	minExtensionToCenterLine	XL and EXL	post-edit/batch-check
	minExtensionToCorner	XL and EXL	post-edit/batch-check
	minInnerVertexProximityExtension	XL and EXL	post-edit/batch-check
	minOppExtension Parameters: `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`, `alignedLayer`, `alignedHorizontal \| alignedVertical`	XL and EXL (scalar and table)	notify/post-edit/batch-check
	edgeMustCoincide	XL and EXL	notify/post-edit/batch-check
	edgeMustOverlap	XL and EXL	notify/post-edit/batch-check
	minNeighborExtension	XL and EXL	notify/post-edit/batch-check
	minQuadrupleExtension Parameters: `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`	XL and EXL	notify/post-edit/batch-check
	minSideExtension Parameter: `exceptEdgeLengthRanges`	XL and EXL	notify/post-edit/batch-check
	minWireOverlap	XL and EXL	notify/post-edit/batch-check
Length	allowedLengthRanges	XL and EXL	notify/post-edit/batch-check
Misc	maxNumCorners	XL and EXL	notify/post-edit/batch-check
Orientation	rectShapeDir Parameters: `exceptEdgeLength`, `exceptExactSize`, `exceptRanges`, `exceptViaLayer`, `exceptViaSize`, `insideLayers`, `insidePurposes`, `outsideLayers`, `outsidePurposes`, `twoSides`, `width`	XL and EXL	notify/post-edit/batch-check
Spacing	allowedSpacingRanges (One layer) Parameters: `widthRanges`, `exceptOverLayer`, `overLayerPrl`, `overLayerWidthRanges`, `exceptNumShapes`, `numShapeDistance`, `numShapeWidthRanges`, `numShapeMaxWidth`, `stepSize`, `stepRange`, `overLayer`	XL and EXL	notify/post-edit/batch-check
	minCenterLineSpacing (Two layers)	XL and EXL	notify/post-edit/batch-check
	minCutClassSpacing (One layer) Parameters: `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`	XL and EXL	enforce/notify/post-edit/batch-check
	minCutClassSpacing (Two layers) Parameter: `cutClassSizeBy` `cutClassSizeBy` specifies extension (sizing) applied on cut edges before spacing is measured.	XL and EXL	enforce/notify/post-edit/batch-check
	minNeighboringShapesSpacing	XL and EXL	notify/post-edit/batch-check
	minEndOfLineToNotchSpacing	XL and EXL	notify/post-edit/batch-check
	minNotchSpacing Parameter: `notchWidth`	XL and EXL	notify/post-edit/batch-check
	minParallelWithinViaSpacing Parameters: `cutClass`, `longEdgeOnly`, `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`	XL and EXL	post-edit/batch-check
	minSideSpacing (One layer)	XL and EXL	enforce/notify/post-edit/batch-check
	minSideSpacing (Two layers)	XL and EXL	notify/post-edit/batch-check
	minSpacing (One layer) Parameter: `exceptEolWidth`, `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`	XL and EXL	enforce/notify/post-edit/batch-check
	minStitchOverlap	XL and EXL	notify/post-edit/batch-check
	minViaSpacing (One layer) Parameters: `exceptExactAligned`, `overLayer`, `overLayerWidth`, `exceptSameNet`, `exceptSameMetal`	XL and EXL	enforce/notify/post-edit/batch-check
	viaSpacing Parameters: `allCuts`, `cutSizeRanges`, `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`	XL and EXL	notify/post-edit/batch-check
Via	allowedCutClass	XL and EXL	notify/post-edit/batch-check
Via	minLargeViaArrayCutSpacing Parameter: `maxNumCuts`	XL and EXL	post-edit/batch-check
Width	allowedNeighborWidthRanges (One layer)	XL and EXL	notify/post-edit/batch-check
	allowedNeighborWidthRanges (Two layers)	XL and EXL	notify/post-edit/batch-check
	allowedNeighborWidthRangesOver	XL and EXL	notify/post-edit/batch-check
	allowedPRBoundaryDimensions	XL and EXL	notify/post-edit/batch-check
	allowedWidthRanges Parameters: `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`	XL and EXL	notify/post-edit/batch-check

Supported Constraints and Parameters (Virtuoso Advanced Node for Layout Only)

Requires Virtuoso Advanced Node Option for Layout (95511) license.

Category	Constraint Name (ASCII Syntax)	Tier Level Support	Support Type
Area	minRectArea Parameters: `colorMask`, `layer`, `overlapType`	XL and EXL	notify/post-edit/batch-check
Complex Spacing	bothSidesViaForbiddenSpacingRange	XL and EXL	notify/post-edit/batch-check
	endOfLineKeepout Parameters: `mask1`, `mask2`, `mask3`, `diffMask`, `twoSides`, `forwardGap`	XL and EXL	notify/post-edit/batch-check
	forbiddenCutClassSpacingRange Parameters: `cutClassPrl,` `allCuts`, `layer`, `layerWidth`, `mask1`, `mask2`, `mask3`, `paraLength`, `within`, `sameMask`, `longEdge`	XL and EXL	notify/post-edit/batch-check
	maxViaArrayClusterSize	XL and EXL	notify/post-edit/batch-check
	minAdjacentFourViaSpacing	XL and EXL	notify/post-edit/batch-check
	minClusterSpacing (One layer) Parameter: `widthDirection` (`widthHorizontal \| widthVertical`)	XL and EXL	post-edit/batch-check
	minCornerSpacing (One layer) Parameters: `sameMask`, `treatLAsJog`	XL and EXL	post-edit/batch-check
	minEndOfLinePerpSpacing Parameters: `negativePRL`	XL and EXL	post-edit/batch-check
	minEndOfLineSpacing Parameter: `exceptExactEolWidth`, `fillConcaveCorner`	XL and EXL	notify/post-edit/batch-check
	minSpanLengthSpacing Parameters: `minSpanForExceptEolWidth`, `minSpanSpacingRanges`, `sameMask`, `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`, `eolExceptionNoPrl`, `diffMask`	XL and EXL	enforce/notify/post-edit/batch-check
	minViaGroupSpacing	XL and EXL	notify/post-edit/batch-check
	orthogonalSnappingLayer	XL and EXL	post-edit
	sameMetalAlignedCuts Parameters: `centerToCenterSpacing \| edgeToEdgeSpacing`, `horizontal \| vertical`, `sameViaConnectivity`	XL and EXL	notify/post-edit/batch-check
	viaGroup	XL and EXL	notify/post-edit/batch-check
	viaKeepoutZone	XL and EXL	post-edit/batch-check
Extension	minExtensionEdge Parameters: `edgeExtension`, `layer`	XL and EXL	post-edit/batch-check
	minNeighborExtension Parameters: `mask1`, `mask2`, `mask3`, `mask4`	XL and EXL	notify/post-edit/batch-check
	minOppExtension Parameters: `hollowHorizontal`, `hollowVertical`	XL and EXL (scalar and table)	notify/post-edit/batch-check
	minQuadrupleExtension Parameter: `maxLength`, `trimLayer`	XL and EXL	notify/post-edit/batch-check
	minVoltageExtension	XL and EXL	notify/post-edit/batch-check
Length	maxEdgeLength	XL and EXL	notify/batch-check
Length	minStepEdgeLength Parameters: `width`	XL and EXL	notify/batch-check
Miscellaneous	preColoredLayers	XL and EXL	notify/post-edit/batch-check
Spacing	allowedCutClass Parameters: `minVoltage`, `maxVoltage`	XL and EXL	notify/batch-check
	allowedSpacingRanges (One layer) Parameters: `exceptWidthEdge`	XL and EXL	notify/batch-check
	mergedViaCornerToCornerSpacing	XL and EXL	notify/batch-check
	minCornerVoltageSpacing	XL and EXL	notify/post-edit/batch-check
	minCutEdgeSpacing (Two layers)	XL and EXL	notify/post-edit/batch-check
	minNestedViaSpacing	XL and EXL	notify/post-edit/batch-check
	minNotchSpacing Parameters: `excludeSpacing`, `horizontal \| vertical`	XL and EXL	notify/post-edit/batch-check
	minSideSpacing (One layer) Parameters: `facingEdges`, `sameMask`, `cornerEuclidian`, `prlRange`, `lengthRanges`, `otherLengthRanges`, `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`, `widthDirection` (`widthHorizontal \| widthVertical`), `facingEdgeDirection`, `otherFacingEdgeRange`	XL and EXL	enforce/notify/post-edit/batch-check
	minSideSpacing (Two layers) Parameters: `cornerEuclidian`, `insideLayers`, `outsideLayers`, `insidePurposes`, `outsidePurposes`, `otherColorMask` (`'otherMask1 \| 'otherMask2 \| 'otherMask3`), `exceptOverlap`, `deltaVoltage`, `prlRange`	XL and EXL	notify/post-edit/batch-check
	minSpacingOver Parameter: `colorMask` (`'mask1 \| 'mask2 \| 'mask3`)	XL and EXL	post-edit/batch-check
	`minStitchSize`	XL and EXL	notify/post-edit/batch-check
	minViaSpacing (One layer) Parameters: `diffMask`, `above`, `below`, `bothAboveBelow`, `shortSideToShortSide \| shortSideToLongSide \| shortSideToAnySide` `\| longSideToLongSide \| longSideToAnySide \| anySideToAnySide, prlRange,viasOnSameNet \| viasOnSameMetal` \| `viasOnSameVia`, `exceptViasOnSameNet \|` `exceptViasOnSameMetal \| exceptViasOnSameVia`	XL and EXL	enforce/notify/post-edit/batch-check
	minViaSpacing (Two layers) Parameters: `exceptSameNet`, `exceptSameMetal`	XL and EXL	enforce/notify/post-edit/batch-check
	multiMaskCheck	XL and EXL	notify/post-edit/batch-check
	orthogonalWSPGrid	XL and EXL	notify/post-edit/batch-check
	trimMinSpacing (One layer)	XL and EXL	notify/post-edit/batch-check
	trimShape	XL and EXL	notify/post-edit/batch-check
	vertexInsideForbidden	XL and EXL	notify/post-edit/batch-check
	viaSpacing Parameters: `sameMask`, `exceptWithin`, `edgeExtension`, `layer`, `extensionDirection`	XL and EXL	notify/post-edit/batch-check

Using DRD Grid Checking

You can use the DRD grid checking capability to verify if any shapes in the layout are off the manufacturing grid specified in the mfgGridResolution section of the technology file. The DRD grid checking capability is available in Post-Edit and Batch-Check modes.

To enable DRD grid checking, select the Grid check box in Post-Edit mode of the DRC Options form. For batch checking, select the Grid check box in the Batch-Check mode of the DRC Options form or the Grid check box in the Check For group box in the Batch Checker form.

After running the grid check, violations found in the design are listed in the Annotation Browser and the corresponding violation markers are created in the layout canvas. In the figure below, you can see that the right vertical edge and the bottom horizontal edge of the Metal2 rectangle are off the grid; marker details are displayed in the Annotation Browser.

Specifying Layers in the Interconnect Section

In VLS EXL, layers that are not specified as validLayers in the interconnect section of a constraint group receive only basic checks (checks available in Virtuoso Layout Suite L); none of the following advanced constraints are applied:

maxNumMinEdges

minCenterToCenterSpacing

minEdgeAdjacentLength

minEndOfLineSpacing

minNumCut

minOppExtension (table)

minParallelViaSpacing

minProtrusionNumCut

minRectArea

minStepEdgeLength

minstubInfluenceSpacing

redundantViaSetback

viaSpacing

viaStackingLimits

Supported Derived Layers

Derived layer support in DRD helps check for DRC violations on layers derived from Boolean operations and on layers derived by sizing other layers.

Supported derived layer operators include:

'and
'or
'not
'xor
'select
'avoiding
'butting
'touching
'straddling
'inside
'outside
'color

Sized layers can be created using the following operators:

'grow
'growVertical
'growHorizontal
'shrink
'shrinkVertical
'shrinkHorizontal

Derived layers with restricted area are created using the 'area operator.

The derived layer definitions are added to the techDerivedLayers section of the layerDefinitions section of the technology file. In general, layer purposes are not supported in derived layer definitions, except with the 'select operator. Derived layer numbers start from 10000 to prevent conflict with the layer numbers assigned to “regular” layers.

For more information about these operators, see Virtuoso Technology Data ASCII Files Reference.

Supported Layer-Purpose Pair and Voltage-Dependent Constraints

Support for Layer-Purpose Pair Constraints

A few constraints can also be applied to user-defined layer-purpose pairs that are defined in the techPurposes section of the technology file. When applied to user-defined layer-purpose pairs, these constraints are checked only if they are specified in the foundry constraint group.

Table 4-1 Supported Layer-Purpose Pair Constraints

Constraint	ASCII Syntax	Tier Level Support	Support Type
Minimum spacing	minSpacing (One layer)	L, XL, GXL, and EXL	enforce/notify/post-edit
Minimum clearance	minSpacing (Two layers)	L, XL, GXL, and EXL	enforce/notify/post-edit
Minimum width	minWidth	L, XL, GXL, and EXL	notify/post-edit

To determine minimum spacing, clearance, or width for an object, the rules are applied in the following order of precedence:

The object’s layer-purpose pair rule
The object’s parent layer-purpose pair rule
The object’s layer rule

Example

This example sets the following conditions:

The minimum width for ("Metal1" "HV") shapes is 0.14, and for all other Metal1 shapes, it is 0.12.
The minimum spacing for ("Metal1" "LV") shapes is 0.4.
The minimum spacing for ("Metal1" "logic") shapes is 0.5.
The minimum spacing for ("Metal1" "HV") shapes is 1.0.
The minimum clearance between a ("Metal1" "HV") shape and a ("Metal1" "LV") shape is 0.5.
The minimum clearance between a ("Metal1" "HV") shape and a ("Metal1" "logic") shape is 0.7.
The minimum clearance between a ("Metal1" "HV") shape and a V1 shape is 0.8.

The user-defined logic, HV, and LV purposes are specified in the techPurposes section of the technology file.

techPurposes(
;( PurposeName Purpose#   Abbreviation   [Attributes] )
;( ----------- --------   ------------   ------------ )
;User-Defined Purposes:
 ( logic       2000       LGC       )
 ( HV          2010       HV        'sigType "digital" 'parent "drawing")
 ( LV          2020       LV        'sigType "digital" 'parent "drawing")
) ;techPurposes

In the foundry constraint group, the minimum width, spacing, and clearance constraints are specified as follows:

spacings(
  ( minWidth    "Metal1"                          0.12 )
  ( minWidth   ("Metal1" "HV")                    0.14 )
  ( minSpacing ("Metal1" "LV")                    0.4  )
  ( minSpacing ("Metal1" "logic")                 0.5  )
  ( minSpacing ("Metal1" "HV")                    1.0  )
  ( minSpacing ("Metal1" "HV") ("Metal1" "LV")    0.5  )
  ( minSpacing ("Metal1" "HV") ("Metal1" "logic") 0.7  )
) ;spacings

spacings(
  ( minSpacing ("Metal1" "HV")  "V1"              0.8  )
) ;spacings

Support for Voltage-Dependent Constraints

In process nodes of 45nm and below, voltage-specific spacing rules are defined by the foundry. These constraints, listed in Table 4-2, are supported in VLS EXL, and can be layer-purpose-pair-based or net-based as described in the following sections:

Table 4-2 Supported Voltage Dependent Rule Constraints

Constraint	ASCII Syntax	Tier Level Support	Support Type
Minimum voltage spacing	minVoltageSpacing (one-layer)	XL, GXL, and EXL	enforce/notify/post-edit
Minimum voltage clearance	minVoltageSpacing (two-layer)	XL, GXL, and EXL	enforce/notify/post-edit

Layer-Purpose Pair–based VDR Support

Voltage-dependent rules can be applied to user-defined layer-purpose pairs that are defined in the techPurposes section of the technology file. The voltage-dependent minimum spacing (minVoltageSpacing (One layer)) and clearance (minVoltageSpacing (Two layers)) constraints are set by layer. A voltage swing must be specified for each layer-purpose pair on which the constraint is defined. When applied to user-defined layer-purpose pairs, these constraints are checked only if they are specified in the foundry constraint group.

Example

This example sets the following conditions:

("Metal1" "HV") shapes have a voltage swing between 0.0 and 3.3.
("Metal1" "LV") shapes have a voltage swing between 0.0 and 1.5.
The minimum spacing between Metal1 shapes whose maximum voltage swing is less than 1.5 is 0.06.
The minimum spacing between Metal1 shapes whose maximum voltage swing is greater than or equal to 1.5 and less than 3.3 is 0.08.
The minimum spacing between Metal1 shapes whose maximum voltage swing is greater than or equal to 3.3 is 0.1.

The user-defined HV and LV purposes are specified in the techPurposes section of the technology file with their associated voltage ranges.

techPurposes(
;(PurposeName Purpose# Abbreviation)
;(---------------------------------)
;User-defined Purposes:
(HV 13 HV 'sigType "digital" 'parent "drawing" voltageRange (0.0 3.3))
(LV 14 LV 'sigType "digital" 'parent "drawing" voltageRange (0.0 1.5))
)

In the foundry constraint group, the voltage-dependent minimum spacing between two shapes on the Metal1 layer (minVoltageSpacing) is described as:

spacingTables(
  ( minVoltageSpacing "Metal1"
   ( "voltage" nil nil )
   ( 0.0 0.06 
     1.5 0.08 
     3.3 0.10 
   )
  )
) ;spacingTables

To determine the minimum spacing from the spacing table, the voltage swing between shapes is calculated as follows:

V_swing = max(maximum voltage of each shape) - min(minimum voltage of each shape)

This voltage swing is compared with the "voltage" index in the spacing table to determine the first value that is less than the calculated voltage swing. The corresponding minimum spacing applies. In this example:

For a voltage swing >= 0.0 and < 1.5, the minimum spacing is 0.06.
For a voltage swing >= 1.5 and < 3.3, the minimum spacing is 0.08.
For a voltage swing >= 3.3, the minimum spacing is 0.1.

Net-based VDR Support

The minimum and maximum voltages on nets can be set from the Property Editor assistant. For more information about the prerequisites for VDR flows and an explanation of how DRD checks voltage-dependent spacing violations, see Virtuoso Voltage Dependent Rules Flow Guide.

Using Density Constraints

Density is calculated as a percentage of the design area that metal on a layer occupies. It is calculated as follows:

Density = Metal area / Total area

The density check performed by DRD in Batch-Check mode relies on the minDensity and maxDensity constraints defined in the technology file, similar to the examples given below for Metal1:

( minDensity "Metal1"
  (( "step" nil nil ))
  (
    60.0 20.0
  )'ref "METAL1.D.1" 'description "Minimum Metal1 Density"
)

( maxDensity "Metal1"
  (( "step" nil nil ))
  (
    60.0  65.0
  ) 'ref "METAL1.D.1" 'description "Maximum Metal1 Density"
)

The second value (20.0) in the minDensity constraint listed above is the minimum density required for Metal1. The second value (65.0) in the maxDensity constraint represents the maximum density allowed for Metal1.

When you run DRD with the Density check option, the values for minDensity and maxDensity constraints are listed in the Min Density and Max Density columns, respectively, in the report displayed in CIW. Density is calculated for each specified window and step size and these results too are displayed in CIW, as shown below:

To run density checks of only one type, minimum or maximum, set the drdEditDensityTypeCheck environment variable to min or max, respectively.

The Density Percentage Statistics figures provide the lowest and the highest area occupied on a metal layer as a percentage of the design. To better understand the significance of the various statistical terms, consider the following example:

Average (Ave)

In the example above, the lowest density value for metal1 is 50%, and the highest density value for metal1 is 75%. Therefore, the average density value is 62.5%.

Average (Ave) = ( Lowest + Highest ) / 2 = 62.5

Median

The median value is obtained after sorting all density values in the ascending order. If the number of density check windows is odd, the median is equal to the value that lies in the 'middle' of the sorted list, and if the number of density check windows is even, the median is calculated as an average of the two 'middle' values.

Standard Deviation (Std Dev)

The standard deviation measures how close the density value for each density check window is to the mean value. A small standard deviation value of 5% indicates that the values are concentrated close to the mean value, which in this case is 62.5%.

Viewing Density Violations in Annotation Browser

When a minDensity constraint is violated, DRD batch checker (Verify – Design) reports it as follows:

When a maxDensity constraint is violated, DRD batch checker (Verify – Design) reports it as follows:

Using Alternate Foundry Constraint Group

If an alternate foundry constraint group (AFCG) is defined in the .cdsenv file, DRD replaces the foundry constraint group and uses the specified AFCG instead.

You can specify an AFCG by setting the following environment variable in your .cdsenv file:

cdba.layout AlternateFoundryCG string "AFCG_name"

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Virtuoso Design Rule Driven Editing User GuideProduct Version IC23.1, September 2023

4

DRD Constraints Support

Supported Constraints

Supported Constraints and Parameters

Supported Constraints and Parameters (Virtuoso Layout Suite EXL)

Supported Constraints and Parameters (Virtuoso Advanced Node for Layout Standard)

Supported Constraints and Parameters (Virtuoso Advanced Node for Layout Only)

Using DRD Grid Checking

Specifying Layers in the Interconnect Section

Supported Derived Layers

Supported Layer-Purpose Pair and Voltage-Dependent Constraints

Support for Layer-Purpose Pair Constraints

Table 4-1 Supported Layer-Purpose Pair Constraints

Example

Support for Voltage-Dependent Constraints

Table 4-2 Supported Voltage Dependent Rule Constraints

Layer-Purpose Pair–based VDR Support

Example

Net-based VDR Support

Using Density Constraints

Average (Ave)

Median

Standard Deviation (Std Dev)

Viewing Density Violations in Annotation Browser

Using Alternate Foundry Constraint Group

Virtuoso Design Rule Driven Editing User Guide
Product Version IC23.1, September 2023