Xilinx, Inc.

Jason H Anderson

Sudip K Nag

Rajeev Jayaraman

Madabhushi V R Chari

Sandor S Kalman

James L Saunders

Kamal Chaudhary

Jennifer Zhuang

Gi-Joon Nam

A method and apparatus for determining routing feasibility of a plurality of nets. Each net has an associated set of one or more routing solutions, wherein each solution specifies one or more routing resources consumed by the net. A liveness Boolean function is generated having variables that represent respective net/solution pairs. If there exists a set of values for the variables such that at least one of the variables for each net is logically true, then the liveness function is true. An exclusivity function is generated using the variables that represent the net/solution pairs. If there exists at least one set of values for the variables such that no resource is used is by more than a predetermined number of nets, then the exclusivity function is true. The nets are routable using the provided solutions if there is one set of values for the variables such that both the liveness and exclusivity functions are true.

Method and apparatus for testing routability

A method and apparatus for placement into a programmable gate array of I/O design objects having different I/O attributes. The I/O attributes of an I/O design object define the electrical characteristics of the design object. The programmable gate array has a plurality of sites (IOBs) arranged into banks supporting a variety of electrical interface characteristics. In an example embodiment, I/O design objects are placed into IOBs of the programmable gate array by first performing simulated annealing that considers conflicts between I/O attributes of I/O design objects as placed into the IOBs. Then, a bipartite matching is performed using placement results from simulated annealing. Finally, if the bipartite matching does not produce a feasible placement, sets of I/O attributes are assigned to the banks based on the previous placement results, and the bipartite matching process is repeated.

Method and apparatus for placement of input-output design objects into a programmable gate array

A method and apparatus for automatic, timing-driven implementation of a circuit design. In one embodiment, the different phases of implementing a circuit design are iteratively performed using timing constraints that are automatically and dynamically generated in each iteration. The process aids in identifying and achieving a maximum performance level of the implemented design. In another embodiment, selected numbers of critical connections are used to dynamically vary the timing constraint. In general, a number of connections is automatically selected from the circuit design and used to derive a new timing constraint to be applied in the next iteration. Slack values associated with paths in the design are also used in deriving the new timing constraint.

Method and apparatus for automatic timing-driven implementation of a circuit design

A method and apparatus for placement into a programmable gate array of input-output (I/O) design objects having different voltage standards. The programmable gate array has a plurality of sites arranged into banks supporting interfaces with a plurality of different input and output voltage standards. In an example embodiment, I/O design objects are placed into IOBs of the programmable gate array by first performing simulated annealing that considers conflicts between design object voltage standards as placed into the IOBs. Then, a bipartite matching is performed using placement results from simulated annealing. Finally, if the bipartite matching does not produce a feasible placement, standards are assigned to the banks based on the previous placement results, and the bipartite matching process is repeated.

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Campbell, CA, United States of America

Jason H Anderson