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Data Handling for Incremental Technology Databases

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Major Data Duplication Rules Summary

You can duplicate some technology data in more than one technology database if doing so accomplishes your design flow objectives. Duplicating most technology data, however, creates conflicts, which must be avoided.

The following paragraphs summarize the major rules of duplication to use to avoid creating conflicts; they delineate

• what can and cannot be duplicated in multiple technology databases in the same graph
• how the software handles specific conflicts between databases
• how the software handles situations when referenced objects are not where they need to be
• special allowance for creating layers that match Virtuoso reserved system layers using the environment variable CDS_ALLOW_VIRTSYSLAY Environment Variable.

This section does not deal with every possible data specification. For complete information, see the Data Handling Table, which provides complete information about how the software handles data in every situation, including how it detects and handles conflicts.

Multiple technology bases in a graph can contain duplicates of the following devices of the same name without conflict:

• MPPTemplates of the same name
• user-defined non-viaDef devices

The following subsections can also be duplicated in multiple technology databases:

• foundry constraint groups and their contents, with the requirement that the objects referenced exist somewhere in the subgraph
• default constraint groups and their contents, with the requirement that the objects referenced exist somewhere in the subgraph
• layer-purpose pairs and their drawing priority order
• techLayerPurposePriorities for the same named layers and purposes
• equivalentLayers
• stampLabels
• labels
• leLswLayers

You cannot duplicate most other technology data, such as viaDefs or any constraint group with the same name other than a foundry or default constraint group.

Although you can specify the dbuPerUU value in every technology database, the value must be the same in all of them.

In certain cases, related data must be specified in the same technology database:

• Any cdsViaDevice and its viaDef must be in the same technology database.
• For any techDisplays definition, the specified layer-purpose pair must be defined in the same technology database.

For information about conflict types and how they occur, see “Conflict Avoidance”.

Data Handling Table

The table in this appendix summarizes how the software checks for data conflicts in a graph and handles the data, conflict or not. The conflict checking and resultant behavior defined in this table apply whenever you introduce a new technology database or make any additions or changes to an existing technology database in a graph, whether compiling a technology file or setting or creating data with a SKILL function. When defining technology data, it is important to be cognizant of the incremental technology database graph and how the data you introduce works with or can conflict with the other data in the graph.

ASCII technology file section/subsection	S/W checks graph for matching	Allow duplicates in graph?	Action taken when match is defined in:			Refer-enced objects	Action taken when referenced object is defined in:
			No db	local db	refer-ence db		No db	local db	refer-ence db
Controls
techParams	Parameter name	Disallowed. Issue warning	Create in local	Overwrite in local	Conflict	N/A	N/A	N/A	N/A
viewTypeUnits	View type name	Disallowed. Issue error	Create in local	Overwrite in local	Conflict	N/A	N/A	N/A	N/A
mfgGridResolu-tion	Construct name	Disallowed. Issue error	Create in local	Overwrite in local	Conflict	N/A	N/A	N/A	N/A
refTechLibs	Construct name	N/A2	Create in local	Overwrite in local	Create in local	N/A	N/A	N/A	N/A
layerDefinitions
techLayers	Layer number or name	Disallowed. Issue warning	Create in local	Warning or do nothing3	Conflict	N/A	N/A	N/A	N/A
techPurposes	Purpose number or name	Disallowed. Issue warning	Create in local	Warning or do nothing3	Conflict	N/A	N/A	N/A	N/A
techLayerPur-posePriorities	Layer name and purpose name	Allowed1	Create in local	Reorder in local	Create in local	Layer, purpose	Disallowed	Update in local	Update in local
techDisplays	LPP name	Allowed1	Create in local	Overwrite in local	Create in local	LPP	Disallowed	Update in local	Dis-allowed
techLayerProp-erties	Layer name and property name	Disallowed	Create in local	Overwrite in local	Error4	Layers	Disallowed	Update in local	Dis-allowed
techDerived-Layers	Derived layer number or name	Disallowed. Issue warning	Create in local	Warning or do nothing3	Conflict	Layers	Disallowed	Update in local	Update in local
layerRules
functions	Layer name	N/A5	Create in local	Overwrite in local	Error4	Layers	Disallowed	Update in local	Dis-allowed
mfgResolutions	Layer name	N/A5	Create in local	Overwrite in local	Error4	Layers	Disallowed	Update in local	Dis-allowed
routingDirec-tions	Layer name	N/A5	Create in local	Overwrite in local	Error4	Layers	Disallowed	Update in local	Dis-allowed
currentDensity/currentDensity-Tables	Layer name	N/A5	Create in local	Overwrite in local	Error4	Layers	Disallowed	Update in local	Dis-allowed
equivalent-Layers	Construct name	Allowed1	Create in local	Overwrite in local	Create in local	Layers	Disallowed	Update in local	Update in local
stampLabels	Construct name	Allowed1	Create in local	Overwrite in local	Create in local	Layers	Disallowed	Update in local	Update in local
labels	Construct name	Allowed1	Create in local	Overwrite in local	Create in local	Layers	Disallowed	Update in local	Update in local
constraintGroups
constraintGroup (foundry/default)	constraint-Group name	Allowed	Create in local	Overwrite in local	Create in local	N/A	N/A	N/A	N/A
constraintGroup (non-foundry/default)	constraint-Group name	Disallowed	Create in local	Overwrite in local	Conflict	N/A	N/A	N/A	N/A
constraints (native OA, in foundry/default constraint group)	CG name, constraint name, layer number or name, or viaDef name	Allowed	Create in local	Overwrite in local	Create in local	Layers, viaDefs	Disallowed	Update in local	Update in local
constraints (native OA, in non-foundry/default constraint group)	CG name, constraint name, layer number or name, or viaDef name	Disallowed	Create in local	Overwrite in local	N/A6	Layers, viaDefs	Disallowed	Update in local	Update in local
LPP based / user defined rule (in foundry/default CG)	CG name, rule name, layer / LPP number or name	Disallowed	Create in local	Overwrite in local	Conflict	Layers, LPPs	Disallowed	Update in local	Update in local
LPP based / user defined rule (in non-foundry/default CG)	CG name, rule name, layer / LPP number or name	Disallowed	Create in local	Overwrite in local	N/A6	Layers, LPPs	Disallowed	Update in local	Update in local
siteDefs
scalarSiteDefs	siteDef name	Disallowed	Create in local	Overwrite in local	Conflict	N/A	N/A	N/A	N/A
arraySiteDefs	siteDef name	Disallowed	Create in local	Overwrite in local	Conflict	siteDefs	Disallowed	Update in local	Update in local
viaDefs
standardVia-Defs	viaDef name	Disallowed	Create in local	Overwrite in local	Conflict	Layers	Disallowed	Update in local	Update in local
customViaDefs	viaDef name	Disallowed	Create in local	Overwrite in local	Conflict	Layers	Disallowed	Update in local	Update in local
viaSpecs
viaSpecs	Layer pair names	Disallowed	Create in local	Overwrite in local	Conflict	Layers, viaDefs	Disallowed	Update in local	Update in local
Devices
cdsViaDevice	Mapped viaDefs name	Disallowed 7	Create in local	Overwrite in local	Conflict	Layers, LPPs	Disallowed	Update in local	Update in local
ruleContact-Device	Mapped viaDefs name	Disallowed 7	Create in local	Overwrite in local	Conflict	Layers, LPPs	Disallowed	Update in local	Update in local
multiplepart-PathTemplates	Device name	Allowed	Create in local	Overwrite in local	Create in local	Layers, LPPs	Disallowed	Update in local	Update in local
leRules
leLswLayers	Construct name	Allowed 1	Create in local	Overwrite in local	Create in local	LPPs	Disallowed	Update in local	Update in local

CDS_ALLOW_VIRTSYSLAY Environment Variable

A special allowance has been made to let you create, in a technology database, an OpenAccess layer that matches a Virtuoso reserved system layer using the environment variable CDS_ALLOW_VIRTSYSLAY.

Creating layers

With CDS_ALLOW_VIRTSYSLAY enabled, create user-defined reserved layers with the SKILL function techCreateLayer(). After the layer is created, Virtuoso adds (mark internally) the specified user-defined reserved layers to the techDB.

Only layer creation is affected by this environment variable, no other Virtuoso operations are affected. This process should be done as a one-time setup for the entire DFII session in order to keep consistency in creating (marking) user-defined reserved layers.

As set by CDS_ALLOW_VIRTSYSLAY, the internally marked user-defined reserved layer will be temporarily created before saving the techDB. After the save operation is complete, the newly-created reserved layer is deleted and remarked to its original state as before the save operation.

Deleting layers

The environment variable does not delete user-defined reserved layers rather techDeleteLayer() resets the marking of the layer, and the layer is not saved to disk.

Modifying layers

Modifying user-defined reserved layers is not supported. You cannot use functions such as the following in this situation: techSetLayerProp(), techSetLayerFunction(), techSetLayerMaskNumber(), techSetLayerName().

Loading an ASCII technology file

With the environment variable set, the specified user-defined reserved layers in the ASCII techfile

• are marked as created in the techDB
• can be saved to disk
• can be dumped to another ASCII techfile
  Only the specified user-defined reserved layers are dumped, not all reserved layers.

Without the environment variable set, the specified user-defined reserved layers in ASCII techfile

• are not marked as created in the techDB
• do not issue a warming message to be compatible with previous releases
• can not be saved to disk because layers are not marked
• can not be dumped to new ASCII techfile because layers are not marked

Enabling CDS_ALLOW_VIRTSYSLAY

This Boolean environment variable is set in a shell window (not in the CIW or through a DFII GUI nor is it listed in the sample .cdsenv file). And it should be used by experienced Virtuoso and techDB users only.

To enable the environment variable, type in a Shell window

setenv CDS_ALLOW_VIRTSYSLAY t

To disable, type

unsetenv CDS_ALLOW_VIRTSYSLAY

or

CDS_ALLOW_VIRTSYSLAY nil

Example:

setenv CDS_ALLOW_VIRTSYSLAY t

env | grep CDS_ALLOW_VIRTSYSLAY 

echo 'tfID = techOpenTechFile("tech_lib_name" "tech.db")' >> test1.au

echo 'layer = techCreateLayer(tfID 235 "prBoundary")' >> test1.au

virtuoso -log test1.log -test test1.au

unsetenv CDS_ALLOW_VIRTSYSLAY

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