Cadence Design Systems, Inc.

Ken Wadland

Randall Scott Lawson

Richard Woodward

Sean Bergan

William Schilp

Richard Allen Woodward, Jr

Charles Winston Grant

Glendine Kingsbury

Greg Horlick

Steve Russo

Jelena Radumilo-Franklin

Walter M Katz

Jia Wu

Keith Woodword

Kota Sujan Reddy

Davis Tsai

Keith Woodward

Brett Allen Neal

Paul S Musto

Donald Keith Morgan

Alan G Strelzoff

David Tsai

Jelena Radumilo-Frankilin

Wiley Gillmor

Joe Morrison

Julie Blumenthal

Joe Smedley

A method, computer program product and apparatus for utilizing simulated locking prior to starting concurrent execution are disclosed. The results of this simulated locking are used to define a canonical ordering which controls the order of execution and the degree of parallelism that can be used.

Deterministic, parallel execution with overlapping regions

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

A method and system for auto-routing wiring within a PCB. In some embodiment, a first broad region within a first layer and a counterpart first broad region within a second layer are defined. The counterpart regions define a first broad via location. In some embodiments, the first and second broad via locations of the first and second layers can then be subdivided into a plurality of triangular regions. The triangular regions on the first and second layers can then be compared to more accurately locate an appropriate via location.

Method and mechanism for implementing PCB routing

Techniques that can improve the efficiency of routing where connections are subject to elongation constraints. The design can be optimized by estimating elongation needed to meet constraints after an initial routing solution has been generated, but before elongation is actually applied to detailed paths. Paths can be re-routed at this earlier stage if it is determined that too much elongation, or too much elongation in crowded areas, will need to be added after the detail routing stage.

Global constraint optimization

A routing method for a multilayer circuit design layout that has a set of possible preferred local routing directions and a default preferred routing direction for each layer. The method receives a set of user specified constraints on routing directions for particular regions of the design layout. The method tessellates the available routing space into separate tiles and automatically defines a preferred local routing direction for each tile based on the user specified constraints. The set of user specified constraints includes user designated flows, locked etches, 'etch keep-out' areas, user 'planned' data, etc. A routing method for a multilayer design layout that receives a first set of user specified preferred routing directions for particular regions of the multilayer design layout. The method tessellates the available routing space into separate tiles and automatically defines a second preferred local routing direction for each tile based on the user specified preferred routing directions.

Localized routing direction

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

Overloaded regions in the routing space of a physical network are resolved via a routing procedure composed of a topological routing phase and a geometric routing phase. The overloads are resolved in the topological routing phase where the constraints of routing are less prohibitive. Multiple topological transformations directed toward resolving the overloads are executed in the topological routing phase prior to a geometric arrangement being realized. The topological transformations may be applied concurrently by way of a multi-threaded embodiment of the invention.

Method for resolving overloads in autorouting physical interconnections

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

A method and system that converges on a global solution to a PCB routing problem using iterations of topology-based routing is described. In some embodiments, the geometric design space is abstracted into a topological graph representing the routing problem. Then, each net is allowed to find its optimal solution path independent of the solution paths for all other nets. The electrical and physical constraints of the system are initially ignored or greatly relaxed. Over each design iteration, the constraints are tightened until a complete, global, topological solution is found. Once a topological solution is found, it is converted into a geometric solution. In the event that no geometric solution exists for that topological solution, then the iteration process is resumed taking into consideration this additional information. The result is the ability to quickly autoroute highly-constrained PCB designs with minimal operator input.

Method and mechanism for implementing automated PCB routing

Automatic bundle filtering is provided to selectively configure a circuit design having a plurality of component terminals for physical implementation. A placement of components is established for a layout of the circuit design, and a plurality of connections to be routed between predetermined terminals of the components are defined for the layout, with a certain plurality of them selectively grouped into at least one candidate bundle. At least one filter is applied to the connections of each candidate bundle for responsive segregation according to a preselected connection discriminant into one or more updated bundle candidates. Each updated bundle candidate is preferably evaluated in accordance with at least one preselected bundling criteria to identify acceptable bundle candidates therefrom. Bundles corresponding to the acceptable bundle candidates are then generated.

Method and system for adaptive bundling of connections in user-guided 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.

An automated method and system is disclosed to determine an Integrated Circuit (IC) package interconnect routing using a mathematical topological solution. A global topological routing solution is determined to provide an IC package routing solution. The global topological solution is used in conjunction with necessary design parameters to determine the optimal geometric routing solution which can include reassignment of IC nets and/or pin assignments and/or relocation of IC nets.

Growing community of inventors

Grafton, MA, United States of America

Ken Wadland