minViaExtension (oacMinViaExtension)

Description

This constraint specifies the required metal extension for vias. It supports the following configurations:

Case 1 - On three sides, the extension should be >= a certain value A as long as one side is >= a certain value B.

Case 2 - The extension on two opposite sides needs to be >= a certain value A as long as one side is >= a certain value B and another side is >= a certain value C.

Case 3 - In addition to the normal extension A, a larger minimum extension B is required to a diagonal edge.

Constraint type:	oaLayerPairConstraint (Symmetric: no)
Value types:	oaValueArrayValue
Database types:	oaDesign, oaTech
Object types:	oaAppObject

The following value types are supported by this constraint:

oaValueArrayValue
The list of extension values as oaIntValues, corresponding to the viaExtensionType parameter.

Units: DBU

The following parameters are supported by this constraint:

Name

Value Type

Units

Default

Description

viaExtensionType
oacViaExtensionTypeConstraintParamType

oaIntValue

Enum

(Required)

Describes the values in the oaValueArrayValue:

"oneThree": First array value used for three sides, second value used for fourth side

"oneOneTwo": First array value used for two opposite sides, second value used for one side, third used for other side.

"diagonal": If the array has two entries, then the first one is used for non-diagonal edges and the second one is for diagonal edges. If the array has 3 entries, then the first two are identical to choice "oneThree". The third is the required extension to a diagonal edge. If the array has 4 entries, then the first three are identical to choice "oneOneTwo". The fourth is the required extension to a diagonal edge.

This parameter is represented by an oaViaExtensionType enumeration:

Value	Name
oacOneThreeViaExtensionType	oneThree
oacOneOneTwoViaExtensionType	oneOneTwo
oacDiagonalViaExtensionType	diagonal