Method and mechanism for identifying and tracking shape connectivity
AssigneeCadence Design Systems, Inc.
InventorEric Nequist
Life of this patent
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Abstract
A method and mechanism is disclosed for identifying and tracking nets in an electrical design. A hierarchical design does not have to be flattened to perform the operation of identifying and tracking nets. To identify sets of connected shapes, instead of having to unfold the entire design hierarchy, only the specific instances of shapes falling within the geometric bounds of shapes identified as being part of a net needs to be unfolded to perform the search. When composing the list of nets for a hierarchical design, the unfolded shapes at other hierarchical levels of the design can be derived based upon virtual terminal structures that implicitly references nets and objects at other levels.
Claims20
A computer implemented method for extracting connectivity for a hierarchical configuration of shapes representing an integrated circuit design, comprising:
- using at least one processor that is configured or programmed for performing a process, the process comprising:
- identifying a hierarchical level in the hierarchical configuration of shapes, wherein
- the hierarchical configuration comprises the hierarchical level and one or more other hierarchical levels;
- and
- extracting nets for the hierarchical level without fully flattening the integrated circuit design to unfold all instantiations of one or more shapes, which are placed in the integrated circuit design by a placement tool, to extract the nets, wherein
- the hierarchical level includes one or more instantiations of but not one or more actual copies of a shape from at least one of the one or more other hierarchical levels in the hierarchical configuration of shapes, and
- the integrated circuit design maintains a hierarchical characteristic of at least some shapes in the hierarchical configuration during the action of extracting the nets.
A computer program product comprising a non-transitory computer usable storage medium storing instructions which, when executed by a processing system, cause the processing system to perform a process for extracting connectivity for a hierarchical configuration of shapes representing an integrated circuit design, the process comprising:
- identifying a hierarchical level in the hierarchical configuration of shapes, wherein
- the hierarchical configuration comprises the hierarchical level and one or more other hierarchical levels;
- and
- extracting nets for the hierarchical level without fully flattening the integrated circuit design to unfold all instantiations of one or more shapes, which are placed in the integrated circuit design by a placement tool, to extract the nets, wherein
- the hierarchical level includes one or more instantiations of but not one or more actual copies of a shape from at least one of the one or more other hierarchical levels in the hierarchical configuration of shapes, and
- the integrated circuit design maintains a hierarchical characteristic of at least some shapes in the hierarchical configuration during the action of extracting the nets.
A system for extracting connectivity for a hierarchical configuration of shapes representing an integrated circuit design, comprising:
- at least one processor that is to:
- identify a hierarchical level in the hierarchical configuration of shapes, wherein
- the hierarchical configuration comprises the hierarchical level and one or more other hierarchical levels;
- and
- extract nets for the hierarchical level without fully flattening the integrated circuit design to unfold all instantiations of one or more shapes, which are placed in the integrated circuit design by a placement tool, to extract the nets, wherein
- the hierarchical level for extraction includes one or more instantiations of but not one or more actual copies of a shape from at least one of the one or more other hierarchical levels in the hierarchical configuration of shapes, and
- the integrated circuit design maintains a hierarchical characteristic of at least some shapes in the hierarchical configuration during the action of extracting the nets.
Dependencies are inferred from the claim text.