Synopsys, Inc.

Guy R Richardson

Dana Rigg

Adding a layer of abstraction to the generation of a runset for DRC rules, by defining a meta language hides from the user the language of a specific verification tool (also called &ldquo;native language&rdquo;). The meta language can be used directly by the user to express in a file (also called &ldquo;meta runset&rdquo;) the DRC rules to be used to create an input for the verification tool in the native language (also called simply &ldquo;runset&rdquo;). A runset generator uses DRC rules supplied by a user to generate a runset in a native language (that is identified by the user). The runset generator can use templates to generate a runset. Each template (also called &ldquo;DRC template&rdquo;) contains code (can be in source form or in object form) for implementation of a DRC rule or derived layer in the native language of a specific verification tool (such as HERCULES). Thus implementation of DRC rules is hidden from the novice user. During automatic generation of DRC rules, the location in a runset of a derived layer specified by the user is optimized, by automatically inserting such a definition immediately prior to a DRC rule that uses the definition (also called &ldquo;just in time&rdquo; layer definition). Such just-in-time layer definition reduces memory usage of the verification tool, and ensures that unused physical layers or derived layers do not appear in the automatically generated runset.

Method and system for automatic generation of DRC rules with just in time definition of derived layers

A method automatically specifies a unique number of an error layer for each DRC rule in a runset. Therefore, all errors related to a given DRC rule are reported by a layout verification tool in the uniquely specified error layer. Furthermore, the method also automatically specifies a unique number of a filter layer that has the same extent as a quality assurance (QA) cell for testing the DRC rule. The filter layer is logically operated (e.g. ANDed) with the error layer to uniquely identify a failure related to the DRC rule (i.e. errors from all other QA cells are filtered out). The QA cells are generated automatically by use of a library of templates. During regression testing, the first time a DRC runset is run against a test design or QA cell library the results are manually verified and stored as &ldquo;expected&rdquo; results. Thereafter when the runset changes or a new version of the verification tool becomes available the test data may be used to identify any differences in the new results, by automatic comparison with the expected results. Specifically, the regression testing method graphically compares the new test results with the expected results and highlights the differences. A utility automatically compares a first set and a second set of shapes in the two sets of results, and can be used for comparison of any two drawings (not necessarily integrated circuit layouts).

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Cedar Park, TX, United States of America

Guy R Richardson