Implementation Specification
DFII constraints minExtension, minEnclosure, and maxEnclosure are deprecated, but ASCII technology file loader and dumper and technology file APIs still accept them and store them in OA as before. However, ASCII technology file loader and tech API techSetOrderedSpacingRule() issue the following warnings for minExtension and minEnclosure. The examples of minExtension and minEnclosure warning messages are given below:
(TECH-230023): techSetLayerPairConstraint: "minExtension" constraint for layer "metal1" and layer "metal2" is deprecated. For backward compatibility, the constraint will continue to be stored in the database and will be accessible with APIs. When the technology database is dumped to ASCII, it will be dumped with the correct mapping("minOverlapDistance").
(TECH-230024): techSetLayerPairConstraint: "minEnclosure" constraint for layer "metal1" and layer "via" is deprecated. You should use "minOppExtension" with the same value for two extensions. For backward compatibility, the constraint will continue to be stored in the database and will be accessible with APIs. When the technology database is dumped to ASCII, it will be dumped with the correct mapping("minExtensionDistance").
For DFII minEnclosure constraint, it is recommended to replace it with minOppExtension with the same extensions. For backward compatibility, this constraint will continue to be stored in the database and will be accessible with APIs. techGetOrderedSpacingRule("minEnclosure") is enhanced to look up minOppExtension with two same extensions if the minOppExtension constraint exists; otherwise, the API looks up oacMinExtension as before.
DFII technology file dumper and API, techGetOrderSpacingRules() write out new DFII constraint names. So, the ASCII technology files that are written out by IC6.1.4_ISR1 and above cannot be loaded by IC.6.1.4FCS and below. For example, the minExtensionDistance constraint cannot be loaded into OA by the IC.6.1.4FCS tech reader. Any technology database on disk should not be impacted but may need to be updated to work with the tools, which respect these constraints.
For DFII maxEnclosure constraint, it is recommended to replace it with maxExtension. Although DFII constraint maxEnclosure is written out to be maxExtension, that should have no impact since the maxExtension constraint has already been defined in IC.6.1.4FCS and below.
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