Cadence Design Systems, Inc.

Richard Woodward

Randall Scott Lawson

Ken Wadland

Sean Bergan

Greg Horlick

William Schilp

Charles Winston Grant

Glendine Kingsbury

Steve Russo

Keith Woodword

Kota Sujan Reddy

Davis Tsai

Keith Woodward

Jia Wu

Jelena Radumilo-Franklin

Walter M Katz

Paul S Musto

Donald Keith Morgan

Jelena Radumilo-Frankilin

Joe Smedley

In one embodiment of the invention, an object oriented autorouter is disclosed for routing nets in a circuit. The object oriented autorouter includes a routing data model (RDM); at least one routing engine, such as a single connection router (SCR), a topographical (TOPO) transformation engine, and a detail geometric (DETAIL) engine, and a command and control module (CCM) coupled together. The RDM reads and write data with a design database as well as reading one or more object oriented design constraints. Each of the routing engines have at least one action to operate on the design database to improve compliance of the circuit to a constraint. The CCM controls the overall routing process of the nets in the circuit and includes at least one director to invoke at least one of the routing engines to achieve compliance with one or more constraints.

Systems for automatic circuit routing with object oriented constraints

Local constraints on placement of routing objects for direct connections between terminals in a circuit layout are determined from global constraints on the placement of the routing objects in a process referred to as global constraint budgeting. An autorouter finds paths in the layout to satisfy the local constraints and ignores the global constraints. The local constraints are updated before each routing pass to ensure that routes are completed on individual direct connections while also satisfying the global constraint.

Budgeting global constraints on local constraints in an autorouter

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.

Method and system for optimized circuit autorouting

Circuit autorouter with object oriented constraints

An approach is provided for selectively optimizing a circuit design, including generating a circuit routing solution according to 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. The potential impact upon constraint compliance is evaluated, including 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 the circuit routing solution is either discarded or accepted responsive to the evaluation.

A mechanism is provided for the user to define a circuit design intent or strategy in the form of data that is stored with the design database. An autorouter then uses this guidance from the user to create a plan for routing the design. The user can then modify their guidance to the router until the results for the plan are acceptable. Using the planned flow, the autorouter can complete the design, creating detailed paths including etch segments and vias. Allowing such interaction with an autorouter significantly reduces the routing time and hence time-to-market.

User-guided autorouting

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San Diego, CA, United States of America

Richard Woodward