Patents by Inventor Sandor S. Kalman

Sandor S. Kalman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9003413
    Abstract: A method, apparatus, and computer readable medium for synchronizing a main thread and a slave thread executing on a processor system are disclosed. For example, the method includes the following elements: transitioning the slave thread from a sleep state to a spin-lock state in response to a wake-up message from the main thread; transitioning the slave thread out of the spin-lock state to process a first work unit from the main thread; determining, at the main thread, an elapsed time period until receipt of a second work unit for the slave thread; transitioning the slave thread to the spin-lock state if the elapsed time period satisfies a threshold time period; and transitioning the slave thread to the sleep state if the elapsed time period does not satisfy the threshold time period.
    Type: Grant
    Filed: September 28, 2009
    Date of Patent: April 7, 2015
    Assignee: Xilinx, Inc.
    Inventors: Jason H. Anderson, Taneem Ahmed, Sandor S. Kalman
  • Patent number: 8671379
    Abstract: Within a system comprising a plurality of processors and a memory, a method of determining routing information for a circuit design for implementation within a programmable integrated circuit can include determining that nets of the circuit design comprise overlap and unrouting nets comprising overlap. A congestion picture can be determined that comprises costs of routing resources for the integrated circuit wherein the cost of a routing resource comprises a measure of historical congestion and a measure of current congestion, and wherein unrouted nets do not contribute to the measures of current congestion in the congestion picture. The method further can include concurrently routing a plurality of the unrouted nets via the plurality of processors executing in parallel according to the congestion picture and storing routing information for nets of the circuit design in the memory.
    Type: Grant
    Filed: October 19, 2012
    Date of Patent: March 11, 2014
    Assignee: Xilinx, Inc.
    Inventors: Jitu Jain, Vinay Verma, Taneem Ahmed, Sandor S. Kalman, Sanjeev Kwatra, Christopher H. Kingsley, Jason H. Anderson, Satyaki Das
  • Patent number: 8312409
    Abstract: A method is described that includes: determining that nets of the circuit design comprise overlap, where the overlap indicates that at least two of the nets of the circuit design use a same routing resource; dividing the nets with overlap among a plurality of buckets, where for each bucket, a net of the bucket does not overlap any other net in the bucket; sequentially processing each bucket by unrouting and rerouting, via at least one processor, nets in the bucket; and storing routing information specifying routes for nets of the circuit design.
    Type: Grant
    Filed: March 5, 2010
    Date of Patent: November 13, 2012
    Assignee: Xilinx, Inc.
    Inventors: Gitu Jain, Vinay Verma, Taneem Ahmed, Sandor S. Kalman, Sanjeev Kwatra, Christopher H. Kingsley, Jason H. Anderson, Satyaki Das
  • Patent number: 8250513
    Abstract: In one embodiment, a method for routing of a circuit design netlist is provided. A processing cost is determined for each net in the netlist. A plurality of regions are defined for the target device such that the total processing costs of nets are balanced between the plurality of regions. Concurrent with routing one or more nets of a first one of the plurality of regions, one or more nets are routed in at least one other of the plurality of regions. Synchronization and subsequent routing are performed for unrouted nets of the netlist.
    Type: Grant
    Filed: November 4, 2010
    Date of Patent: August 21, 2012
    Assignee: Xilinx, Inc.
    Inventors: Vinay Verma, Gitu Jain, Sanjeev Kwatra, Taneem Ahmed, Sandor S. Kalman
  • Patent number: 8201130
    Abstract: A method is provided for routing a circuit design netlist. Nets of the netlist are grouped into a plurality of sub-netlists. For each sub-netlist, nets of the sub-netlist are routed as a function of congestion between nets of the sub-netlist. Congestion between nets of other sub-netlists in the plurality of sub-netlists is not taken into account. If two or more nets of the netlist are routed through the same routing resource, a global congestion history data set is updated to describe congestion between all nets in the netlist, and the two or more nets of the netlist are unrouted. The two or more nets are each rerouted as a function of the global congestion history data set and congestion between nets of the same sub-netlist as the net.
    Type: Grant
    Filed: November 4, 2010
    Date of Patent: June 12, 2012
    Assignee: Xilinx, Inc.
    Inventors: Sandor S. Kalman, Vinay Verma, Gitu Jain, Taneem Ahmed, Sanjeev Kwatra
  • Patent number: 7797665
    Abstract: Nets of a logic design are efficiently routed in a programmable logic device, which includes multiple types of programmable interconnects. Patterns are read from a library in a storage device. Each pattern includes an ordered set of the types of the programmable interconnects. A path is determined from the source to the destination for each net of the logic design. The path is through a sequence of the programmable interconnects having types that correspond to each type in the ordered set of a selected pattern. A description is output of the path for each of the nets.
    Type: Grant
    Filed: December 6, 2007
    Date of Patent: September 14, 2010
    Assignee: Xilinx, Inc.
    Inventors: Hui Xu, Vinay Verma, Anirban Rahut, Jason H. Anderson, Sandor S. Kalman
  • Patent number: 7614025
    Abstract: A method of implementing a circuit design in a target device can include identifying routing information for a circuit design that has been at least partially implemented. A plurality of empty sites of the target device within which the circuit design is to be implemented can be identified. The method also can include determining whether each of the plurality of empty sites of the target device has a routing conflict according to the routing information of the circuit design and generating a list specifying each empty site of the target device that has a routing conflict.
    Type: Grant
    Filed: April 18, 2007
    Date of Patent: November 3, 2009
    Assignee: XILINX, Inc.
    Inventors: Raymond Kong, Sandor S. Kalman
  • Patent number: 7392498
    Abstract: Method and apparatus for implementing a pre-implemented circuit design for a programmable logic device is described. In one example, a definition of the pre-implemented circuit design is obtained (504). The definition includes a first physical implementation and a first logical implementation. A second logical implementation is produced (506) for an instance of the pre-implemented circuit design using the first logical implementation. A second physical implementation is produced (510, 512) for then instance of the pre-implemented circuit design using the first physical implementation.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: June 24, 2008
    Assignee: Xilinx, Inc
    Inventors: Sankaranarayanan Srinivasan, W. Story Leavesley, III, George L. McHugh, Douglas P. Wieland, Sandor S. Kalman, III
  • Patent number: 7134112
    Abstract: A method for completing the routing of a partially routed design is provided. The unrouted pins are routed to generate a first plurality of nets that may contain shorts or overlaps between the nets. The nets are analyzed to obtain timing information, and then divided into a set of critical and a set of non-critical nets. The non-critical nets are hidden, and the critical nets are rerouted to remove overlaps. The non-critical nets are then unhidden. The non-critical nets and rerouted critical nets are then rerouted so as to remove overlaps.
    Type: Grant
    Filed: July 21, 2003
    Date of Patent: November 7, 2006
    Assignee: Xilinx, Inc.
    Inventors: Jason H. Anderson, Vinay Verma, Sandor S. Kalman
  • Patent number: 7111268
    Abstract: A method for post-layout timing optimization is disclosed. The method performs timing analysis on a design to obtain timing information such as critical paths and slack values. Incremental placement based on the timing information is performed. A new routed design is generated by applying incremental routing to the result of incremental placement. The routed design is stored if its performance is better than the previous routed design. The above steps are repeated until a predetermined criterion is met.
    Type: Grant
    Filed: August 20, 2003
    Date of Patent: September 19, 2006
    Assignee: Xilinx, Inc.
    Inventors: Jason H. Anderson, Sandor S. Kalman, Vinay Verma
  • Patent number: 6877040
    Abstract: 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.
    Type: Grant
    Filed: July 25, 2000
    Date of Patent: April 5, 2005
    Assignee: Xilinx, Inc.
    Inventors: Gi-Joon Nam, Sandor S. Kalman, Jason H. Anderson, Rajeev Jayaraman, Sudip K. Nag, Jennifer Zhuang
  • Patent number: 6757879
    Abstract: The present invention provides a new method to handle power and ground signals in modular design of programmable logic devices. During module implementation, the power and ground signals of each module are associated with area constraint properties. When performing routing in the module implementation phase, the power and ground signals together with regular local signals of the module are routed in accordance with their respective area constraint properties. However, the area constraint properties of the power and ground signals are removed during assembly phase while the area constraint properties of the local signals are retained.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: June 29, 2004
    Assignee: Xilinx, Inc.
    Inventors: Raymond Kong, Sandor S. Kalman
  • Patent number: 6732349
    Abstract: Routing algorithms can be modified to increase the number of programmable interconnect points (PIPs) used in a routing pattern. A file is set up to store information on whether a PIP has been covered. The cost of a node can be decreased by a predetermined value if two nodes are connected by an uncovered PIP. In another embodiment, a file is set up to store a count for each PIP. The count is increased each time the PIP is used in a routing. The cost of a node can be increased by multiplying a predetermined value and the count of a PIP associated with the node.
    Type: Grant
    Filed: August 29, 2002
    Date of Patent: May 4, 2004
    Assignee: Xilinx, Inc.
    Inventors: Richard Yachyang Sun, Sandor S. Kalman, Sudip K. Nag
  • Patent number: 6496970
    Abstract: The present invention provides a new method to handle power and ground signals in modular design of programmable logic devices. During module implementation, the power and ground signals of each module are associated with area constraint properties. When performing routing in the module implementation phase, the power and ground signals together with regular local signals of the module are routed in accordance with their respective area constraint properties. However, the area constraint properties of the power and ground signals are removed during assembly phase while the area constraint properties of the local signals are retained.
    Type: Grant
    Filed: October 25, 2001
    Date of Patent: December 17, 2002
    Assignee: Xilinx, Inc.
    Inventors: Raymond Kong, Sandor S. Kalman
  • Patent number: 6484298
    Abstract: 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.
    Type: Grant
    Filed: May 18, 2000
    Date of Patent: November 19, 2002
    Assignee: Xilinx, Inc.
    Inventors: Sudip K. Nag, Kamal Chaudhary, Jason H. Anderson, Madabhushi V. R. Chari, Sandor S. Kalman
  • Patent number: 6480999
    Abstract: The present invention provides a new method to handle power and ground signals in modular design of programmable logic devices. During module implementation, the power and ground signals of each module are associated with area constraint properties. When performing routing in the module implementation phase, the power and ground signals together with regular local signals of the module are routed in accordance with their respective area constraint properties. However, the area constraint properties of the power and ground signals are removed during assembly phase while the area constraint properties of the local signals are retained.
    Type: Grant
    Filed: July 26, 2001
    Date of Patent: November 12, 2002
    Assignee: Xilinx, Inc.
    Inventors: Raymond Kong, Sandor S. Kalman