System for implementing post-silicon IC design changes
AssigneeSpringsoft USA, Inc.
InventorsHsin-Po Wang, Yu-Sheng Lu, Fong-Yuan Chang, Yi-Der Lin, Sung-Han Tsai, Ru Lin Yang, Chun-Cheng Chi, Hsueh Liang Hsu
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Abstract
An engineering change order (ECO) modifying an IC having spare cell instances is implemented by converting active cell instances implementing portions of the IC to be deleted into additional spare cell instances, by creating a technology independent behavioral model of portions of the IC to be added, by selecting spare cell instances to implement the behavior model, and by routing nets to the selected spare cell instances in a way that minimizes a number of metal layers of the IC that are modified.
Claims16
Non-transitory computer-readable storage media containing software, which when read and executed by a computer, causes the computer to carry out a method for implementing an engineering change order (ECO) by modifying a first integrated circuit (IC) layout for a first IC to produce a second IC layout for a second IC, wherein the first and second ICs include active cell instances interconnected by nets to form subcircuits, and include spare cell instances not interconnected by nets, the method comprising the steps of:
- a. comparing netlists describing the first and second ICs to identify additions and deletions, wherein additions are subcircuits formed by active cell instances and nets included in the second IC but not in the first IC, and wherein deletions are subcircuits formed by active cell instances and nets included in the first IC but not included in the second IC;
- b. reclassifying active cell instances of the first IC that form the identified deletions as spare cell instances of the first IC;
- and
- c. performing ECO re-synthesis comprising generating a technology independent model depicting circuit behavior of the identified additions and selecting spare cell instances of the first IC to implement the circuit behavior depicted by the technology independent model,
- and wherein step c comprises the substeps of:
- c1. identifying partitions of the technology independent model, each of which specifies circuit behavior that can be implemented by any spare cell instance of the first IC not already committed to implementing circuit behavior specified by any other partition of the technology independent model;
- c2. selecting a partition from among all partitions identified at step c1 that specifies circuit behavior that a spare cell instance of the first IC can implement at a lowest cost as determined by a cost function, and committing that spare cell instance to implement the selected partition in the second IC;
- c3. modifying the technology independent model to delete the partition selected at step c2;
- and
- c4. repeating substeps c1, c2 and c3 until all portions of the technology independent model have been deleted.
Non-transitory computer readable storage media containing software, which when read and executed by a computer, causes the computer to carry out a method for implementing an engineering change order (ECO) for modifying an initial integrated circuit (IC) layout for guiding fabrication of an IC to produce a modified IC layout,
- wherein the initial IC layout describes the IC as comprising a plurality of cell instances and a plurality of nets for providing connections for conveying signals between the cell instances,
- wherein the initial IC layout describes the nets as including conductors formed on a plurality of metal layers of the IC,
- wherein at least one of the metal layers is designated as a frozen layer that is to remain unchanged in the modified IC layout, and all others of the metal layers are designated as unfrozen layers that may be changed in the modified IC layout,
- wherein the ECO indicates that at least one particular connection between cell instances provided by at least one particular net of the plurality of nets is to be broken, and
- wherein each particular connection cannot be broken without modifying a frozen layer,
- the method comprising the steps of:
- a. identifying at least one other connection between cell instances provided by at least one other net of the plurality of nets which, when broken, would have a same effect on behavior of the IC as breaking said at least one particular connection, and which can be broken by deleting a portion of each other net from the IC layout without modifying any frozen layer, and
- b. deleting from the initial IC layout said portion of each other net while refraining from modifying any frozen layer.
Dependencies are inferred from the claim text.