oaAllowedClearanceRange (oacAllowedClearanceRange)

Description

The oacAllowedClearanceRange layer pair constraint specifies the range of clearances, in database units, that are allowed between shapes on different layers. A single value can be specified for both the upper and lower bounds of the range, which means that the clearance for this range must be precisely the specified value. Multiple allowed ranges and discrete values can be specified.

Constraint at a Glance

Constraint type:	oaLayerPairConstraint (Symmetric: no)
Value types:	oaIntRangeArrayValue, oaIntRangeArray1DTblValue, oaIntRangeArray2DTblValue
Database types:	oaTech
Object types:	oaAppObject

Values

The following value types are supported by this constraint:

oaIntRangeArrayValue
This oaIntRange value is stored in an array table type object. This value is used when the clearance is independent of width.

Units: DBU
oaIntRangeArray1DTblValue
This oaIntRange value is stored in an array table type object. This value is used when the clearance is dependent on the width of one of two shapes.

Units: DBU
oaIntRangeArray2DTblValue
This oaIntRange value is stored in an array table type object. This value is used when the clearance is dependent on the width of both shapes

Units: DBU

Parameters

The following parameters are supported by this constraint:

Name	Value Type	Units	Default	Description
width oacWidthConstraintParamType	oaIntValue	DBU	None	This constraint applies when both the width of the shape on layer 1 and the width of the shape on layer 2 are less than the given width value.

Examples

Manufacturing Reasons

Some process technologies define clearance rules between gates and other polysilicon shapes including dummy poly. The rule usually applies when the cumulative run length between a gate shape and the facing poly shape exceeds a certain value.