US 8,146,042 B1Granted

Method and system for optimized circuit autorouting

AssigneeCadence Design Systems, Inc.

InventorsKen Wadland, Richard Woodward, Randall Lawson, Greg Horlick

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Abstract

An approach is provided for selectively optimizing a circuit design to be physical implemented. The approach includes generating a circuit routing solution in accordance with a plurality of constraints for parametric resources of the circuit design, with the constraints being defined respectively by a plurality of corresponding constraint instances. Each constraint instance variably indicates an effective constraining limit and degree of consumption for at least one of the parametric resources. At least one of the constraints is selectively adjusted by a predetermined over-constraining amount, and the circuit routing solution is preliminarily modified by applying at least one routing action selected responsive to the constraint adjustment. An automatic evaluation is then made of the potential impact upon constraint compliance. The evaluation includes generating a relative cost measure for the preliminary modification of the circuit routing solution, based at least partially upon each of the constraint instances. Thereafter, the preliminary modification of said circuit routing solution is either discarded or accepted responsive to the evaluation. A number of these operations may be repeated in recursive manner, if appropriate for the given application.

Claims27

Dependent claims

A computer program product for selectively optimizing a circuit design for physical implementation, the computer program product comprising a non-transitory computer usable medium having a computer readable program code embodied therein, the computer readable program code comprising program instructions for:

(a) generating a circuit routing solution, by a processor, in accordance with a plurality of constraints for parametric resources of the circuit design, said constraints being defined respectively by a plurality of corresponding constraint instances, each said constraint instance variably indicating a constraining limit and degree of resource consumption for at least one of said parametric resources;
(b) selectively adjusting, by a processor, at least one of said constraints by an over-constraining amount;
(c) preliminarily modifying, by a processor, said circuit routing solution by applying at least one routing action selected responsive to said constraint adjustment;
(d) evaluating potential impact upon constraint compliance, by a processor, said evaluation including generating a relative cost measure for said preliminary modification of said circuit routing solution, based at least partially upon each of said constraint instances;
(e) alternatively discarding or accepting, by a processor, said preliminary modification of said circuit routing solution responsive to said evaluation, whereby acceptance of said preliminary modification is conditioned upon measurable validation of favorable constraint compliance impact associated therewith;
and,
(f) optionally repeating (b)-(e) in recursive manner.

4 more elements

A non-transitory computer readable medium encoded with a computer program including computer executable instructions for selectively optimizing a circuit design for physical implementation, comprising:

(a) executing an autorouting engine, by a processor, to generate a circuit routing solution in accordance with a plurality of constraints for parametric resources of the circuit design, said constraints being defined respectively by a plurality of corresponding constraint instances, each said constraint instance including for at least one said constraint:
a preset resource limit defining a minimum or maximum threshold for said parametric resource;
a compliance level adjustably defining a constraining limit relative to said resource limit;
a goal level adjustably defining a target constraining limit relative to said resource limit;
and, a resource status variably indicating a degree of resource consumption of said parametric resource;
(b) selectively adjusting, by a processor, said goal level of at least one of said constraints by a predetermined over-constraining amount;
(c) preliminarily modifying, by a processor, said circuit routing solution by applying at least one routing action selected responsive to said constraint adjustment;
(d) evaluating, by a processor, potential impact upon constraint compliance, said evaluation including:
(1) detecting any violation of a predefined design rule applicable to physical implementation of the circuit design;
(2) detecting any non-compliance in said constraint instances, said non-compliance being indicated by said degree of parametric resource consumption in said constraint instance surpassing said constraining limit thereof;
and,
(3) generating a relative cost measure for said preliminary modification of said circuit routing solution, based at least partially upon each of said constraint instances;
(e) alternatively discarding or accepting, by a processor, said preliminary modification of said circuit routing solution responsive to said evaluation, said compliance level of said constraint modified at (b) being updated to equal said goal level in value upon acceptance of said preliminary modification;
and,
(f) optionally repeating (b)-(e) in recursive manner.

12 more elements

Dependencies are inferred from the claim text.