OpenAccess 2.2 Feature List

OpenAccess can add new kinds of data to the data model as newer versions are released. For example, OpenAccess added a new feature to allow figures to be grouped and manipulated as a single entity.

Each new kind of data added to the data model is called a feature. When a database contains one or more instances of the new kind of data, then it is using that feature. In many cases, older applications will not be able to use databases that have new features.

OpenAccess includes the infrastructure to support feature-based compatibility, which means that OpenAccess has the ability to control the access that an application has to an OpenAccess database based on

The revision of the OpenAccess data model that the application supports. This version is declared by the application in its init call.
The new features used in that database

When OpenAccess releases a new feature, that feature has a set of policies that define how applications can access databases that include those new features.

This document includes:

Feature List
Policy Definitions
Version History for New Features
Feature Descriptions

For more information, refer to Feature-Based Data Compatibility in Compatibility for OpenAccess Applications and Data.

2.2 Feature List

The following table lists the new features available in the OpenAccess 2.2 releases and shows their policies. A policy can pertain to the version of the OpenAccess shared libraries, or to the data model revision supported by the application.

The table also shows the part of the OpenAccess data model that contains the new feature, and the data model revision number that first contained the new feature.

Important: Recognition of features in OpenAccess started with the OpenAccess 2.2.4 (p029) release. The default policy for all features is that no database with features can be opened by a version of the OpenAccess libraries earlier than 2.2.4 (p029) or an oacCannotUpgrade exception is thrown.

Feature Name	Policy	Applicable if ...	Relevant Part of the Data Model	Initial Data Model Rev
Huge Databases	Cannot open with compat. exception	App data model rev. < 1	oacBaseDBType oacNoDomain oacFutureCategory oacUnknonwType oacAdditionDataModelModType	1
FigGroup	Cannot open with compat. exception	OpenAccess libs < = 2.2.5 (P035)	oacDesignDBType oacBlockDomain oacGeometryCategory oacFigGroupType oacAdditionDataModelModType	2
FigGroup	Cannot append	OpenAccess libs > 2.2.5 (P035)		2
Reference to FigGroup	Cannot open with compat. exception	App data model rev. < 2	oacDesignDBType oacBlockDomain oacGeometryCategory oacFigGroupType oacAdditionDataModelModType	2
Contains New Default Constraint Groups	Cannot open with compat. exception	OpenAccess libs < 2.2.6	oacDesignDBType oacNoDomain oacConstraintsCategory oacConstraintGroupType oacAdditionDataModelModType	2
New Constraints Of Existing Types In Rev1	Default policy only		oacConstraintsCategory oacAdditionDataModelModType	2
Modified Constraints In Rev1	Cannot open with compat. exception	App data model rev. < 2	oacConstraintsCategory oacChangeDataModelModType	2
New Constraint Params In Rev1	Default policy only		oacConstraintsCategory oacConstraintParamType oacAdditionDataModelModType	2
New Value Type in Rev1	Cannot open with compat. exception	App data model rev. < 2	oacConstraintsCategory oacAdditionDataModelModType	2
Constraint ID	Cannot append	OpenAccess libs < 2.2.6	oacConstraintsCategory oacAdditionDataModelModType	2
Constraint Description	Cannot append	OpenAccess libs < 2.2.6	oacConstraintsCategory oacAdditionDataModelModType	2
Gate Grounded Attribute on Tech	Cannot append (if set to non-default value)	OpenAccess libs < 2.2.6	oaTechDBType oacTechCategory oacTechType oacAdditionDataModelModType	2
New Material Type Enum	Cannot open with compat. exception	App data model rev. < 2	oaTechDBType oacTechCategory oacPhysicalLayerType oacAdditionalDataModelModType	2
Layer Array Constraint	Cannot open with compat. exception	App data model rev. < 2	oacConstraintsCategory oacAdditionDataModelModType	2
New Derived Layer	Cannot open with compat. exception	App data model rev. < 2	oaTechDBType oacTechCategory oacDerivedLayerType oacAdditionDataModelModType	2
Derived Layer Param	Cannot append	OpenAccess libs < 2.2.6	oaTechDBType oacTechCategory oacDerivedLayerParamType oacAdditionDataModelModType	2
Reference to Derived Layer Param	Cannot open with compat. exception	App data model rev. < 2	oaTechDBType oacTechCategory oacDerivedLayerParamType	2
IncrementalTech	Cannot open with compat. exception	App data model rev. < 3	oacTechDBType oacNoDomain oacTechCategory oacTechType oacChangeDataModelModType	3

Policy Definitions

Cannot open

The database contains a new feature and cannot be opened.
The version of OpenAccess software that you are using was released before 2.2.4 (p029) and does not include the infrastructure to support feature-based compatibility. The database containing the new feature cannot be opened, and the exception message will not contain details about the feature or the compatibility error.
Cannot open with compatibility exception

The database contains a new feature and cannot be opened.
The version of OpenAccess software that you are using is older than the version of OpenAccess that created the database containing the new feature. The database containing the new feature cannot be opened, but the exception does provide an oaCompatibilityError with details about the compatibility error.
Cannot append

The database contains a new feature and cannot be opened for append 'a' mode.
The version of OpenAccess software that you are using is older than the version of OpenAccess that created the database containing the new feature. The database cannot be opened in append mode 'a', but can be opened in read mode or in a forced append mode ‘A’. If the database is opened in one of these modes and saved, the data for the new feature will be lost.

Version History for New Features

The following table shows the data model version history of OpenAccess releases and the new features defined and supported in each data model version.

Data Model Revision Number	OpenAccess Version	Feature
0	2.2.0 through 2.2.3 (or p032)	Base OpenAccess 2.2 data model
1	2.2.4 (or p033)	Huge Databases
2	2.2.6 (or p045)	FigGroups, Constraint features
3	2.2.6 (or p045)	IncrementalTech

Feature Descriptions

Contains New Default Constraint Groups

Default constraint groups have been added to objects that formerly did not have default constraint groups.

For more information, refer to:

FigGroup

The oaFigGroup object represents a collection that can be used by graphical design-entry tools to hold a set of figures that can be easily replicated and reused. An oaFigGroup is purely geometric and does not contain connectivity objects or anything else that is not a figure.

For more information, refer to:

Reference to FigGroup

This feature represents items in OpenAccess that make use of FigGroups. This feature is present if

A FigGroup belongs to an oaGroup
A FigGroup has a property on it, and that property belongs to an oaGroup
A FigGroup belongs to a marker
A FigGroup is part of an inter-pointer appDef
A FigGroup has constraints on it

New Constraints of Existing Types in Rev1

New LayerConstraints

oacMinParallelViaSpacing
oacMinEndOfLineSpacing
oacMaxFloatingArea
oacMinLargeViaArraySpacing
oacMinLargeViaArrayWidth
oacMinLargeViaArrayCutSpacing
oacRectangularLargeViaArraysAllowed
oacMinEdgeMaxCount
oacMinEdgeAdjacentDistance
oacMaxDiagonalEdgeLength
oacMaxRoutingDistance
oacKeepAlignedShapeAndBoundary

See oaType, oaLayerConstraintType.

New LayerPairConstraints

oacMinRedundantViaSetback
oacMinConcaveCornerOverlap
oacMinConcaveCornerExtension
oacKeepAlignedShapes
oacMinEndOfLineExtension

See oaLayerPairConstraintType

New SimpleConstraints

oacHorizontalPlacementGridPitch,
oacHorizontalPlacementGridOffset
oacVerticalPlacementGridPitch
oacVerticalPlacementGridOffset

Modified Constraints In Rev1

Enhanced Layer Constraints and Layer Pair Constraints

oacMinDualExtension

New Valid Value Type
oaIntDualIntArrayTblValue	When an array of value pairs is assigned for a given width, width is expressed as an oaInt4, the array is an oaDualIntArray, and the value type is an oaIntDualIntArrayTblValue.

oacAntenna

New Parameters
oacAntennaAreaFactorConstraintParamType	oaFloatValue	Specifies the metal factor. Depending on the value of the isSide attribute, this parameter represents one of the following: The areaFactor (when calculating antenna/gate area ratios using metal area) The sideFactor (when calculating antenna/gate ratios using metal side area) The default value for this parameter is 1 in both cases.
oacAntennaDiffPlusFactorConstraintParamType	oaFloatValue	Specifies the diffPlusFactor. The default value for this parameter is 0.
oacAntennaDiffMinusFactorConstraintParamType	oaFloatValue	Specifies the diffMinusFactor. The default value for this parameter is 0.
oacAntennaDiffAreaReduceFactorConstraintParamType	oaFlt1DtblValue	Specifies the diffAreaReduceFactor. This table stores the factors based on the diffusion area. These values typically are in the range of 0 to 1. The default value for this parameter is 1.
oacAntennaCumRoutingPlusCutConstraintParamType	oaBooleanValue	Specifies the cumRoutingPlusCut. This parameter determines how the cumulative antenna ratios for metal and cut layers are calculated. The default value for this parameter is false.

oacMinSpacing

New Parameters

oacWidthLengthTableTypeConstraintParamType

oaIntValue

Specifies how the oaInt2DTblValue table, supplied as the constraint value, is interpreted by applications. There are two possible interpretations:

The allowed spacing is based on the width of the wider shape and the parallel run length between the two shapes.
The allowed spacing is based on the widths of both shapes.

oacDistanceMeasureTypeConstraintParamType

oaIntValue

Specifies whether the distances are measured as Euclidean (which is the the default) or Manhattan.

oacMinClearance

New Parameter
oacDistanceMeasureTypeConstraintParamType	oaIntValue	Specifies whether the distances are measured as Euclidean (which is the default) or Manhattan.

New Valid Value Type
oaInt2DTblValue	Specifies the required clearance width as a function of two keys.

oacMinExtension

New Parameter
oacDistanceMeasureTypeConstraintParamType	oaIntValue	Specifies whether the distances are measured as Euclidean (which is default) or Manhattan.

oacMinSameNetSpacing

New Valid Value Type
oaInt1DtblValue	Specifies the dependency of the net spacing on the width of the shape on the net.

See oaConstraintParamType.

New Constraint Params In Rev1

Built-in constraint parameters of the following type indicate the presence of this feature:

oacWidthLengthTableTypeConstraintParamType
oacDistanceMeasureTypeConstraintParamType
oacCountConstraintParamType
oacParallelEdgeSpaceConstraintParamType
oacParallelEdgeWithinConstraintParamType
oacMaxLengthConstraintParamType
oacMaxEdgeCountConstraintParamType
oacMinNumCutsConstraintParamType
oacAntennaAreaFactorConstraintParamType
oacAntennaDiffPlusFactorConstraintParamType
oacAntennaDiffMinusFactorConstraintParamType
oacAntennaDiffAreaReduceFactorConstraintParamType
oacAntennaCumRoutingPlusCutConstraintParamType
oacAlignmentTypeConstraintParamType
oacEndOfLineSpaceConstraintParamType

New Value Type in Rev1

Four new oaValue subclasses are added to support new constraints and derived layers:

Constraint ID

A numeric ID for constraints.

Constraint Description

A string description for constraints.

Gate Grounded Attribute on Tech

A new GateGrounded attribute on oaTech that indicates whether or not the gate is grounded. The default value is false.
The feature is present only if this attribute is set to true.

New Material Type Enum

The oaMaterialTypeEnum includes a new enum value that can be used when creating physical layers.

enum oaMaterialEnum {
    // Existing enumeration values here ...
	
    oacPassivationCutMaterial
};


const oaString  oaMaterial::names[] = {
  // Existing names here...
  
  "passivationCut"
};

Layer Array Constraint

Defines constraints for three or more layers. Refer to oaLayerArrayConstraint for more information.

New Derived Layer

The oaDerivedLayer class now provides the ability to create sized layers or layers based on operations. Also, layers can be derived from one or two layers. Derived layers can now have associated parameters.

Refer to the following functions in the oaDerivedLayer class documentation for more information.

oaDerivedLayer* oaDerivedLayer::create(oaTech*                             tech,  
                                       const oaLayer*                      layer1,  
                                       const oaDerivedLayerDef*            def,  
                                       const oaString&                     name,  
                                       oaLayerNum                          number,  
                                       const oaDerivedLayerParamArray *    params = NULL 
                                       )  [static]

oaDerivedLayer* oaDerivedLayer::create(oaTech*            tech,  
                                       oaLayer*           layer1,  
                                       oaLayer*           layer2,  
                                       oaLayerOp          operation,  
                                       const oaString&    name,  
                                       oaLayerNum         number 
                                       )  [static]

oaDerivedLayer* oaDerivedLayer::find(const oaTech*                      tech,  
                                     oaLayerNum                         layer1Num,  
                                     oaLayerNum                         layer2Num,  
                                     const oaDerivedLayerDef*           def,  
                                     const oaDerivedLayerParamArray*    params = NULL,  
                                     oaBoolean                          local = false 
                                     )  [static] 


oaDerivedLayer* oaDerivedLayer::find(const oaTech*                      tech,  
                                     oaLayerNum                         layer1Num,  
                                     const oaDerivedLayerDef*           def,  
                                     const oaDerivedLayerParamArray*    params = NULL,  
                                     oaBoolean                          local = false 
                                     )  [static]

Derived Layer Param

oaDerivedLayerParam describes additional information for derived layers. For example, a derived layer with an inside layer operation has two input layers and one parameter, which describes the net connectivity of the shapes.

oaDerivedLayerParamDef enforces the value type of a derived layer parameter.

Reference to Derived Layer Param

This feature represents items in OpenAccess that make use of derived layer parameters.

Huge Database

OpenAccess provides the ability to open very large database in which a single type of data takes over 4 Gbytes of memory.

IncrementalTech

OpenAccess lets applications use incremental technology databases to provide technology information from multiple sources, such as the foundry, an IP provider, or a designer, to the application at different points in the design cycle. Applications can incrementally assemble technology information by creating references from one oaTech database to other oaTech databases. For more information, refer to Using Technology Databases in the Programmers Guide.

Note: The IncrementalTech feature is present in a technology database if that technology database contains references to other technology databases. However, even if the references are unset, if the technology database still contains any unbound object headers that cannot be resolved, the feature is still considered present.

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