Patents Represented by Attorney, Agent or Law Firm Michael R. Casey, Esq.
  • Patent number: 6427156
    Abstract: An improved CLB architecture, wherein the use of dedicated AND gates to generate a carry chain input signal facilitates low latency multiplication and makes efficient use of four-input function generators. In one embodiment of the invention, when multiplication using a binary addition tree algorithm is used, AND gates to implement single-bit multiplication are provided within the available function generators and duplicated in a dedicated AND gate accessible outside the corresponding function generator as a carry-chain input signal. In another embodiment, carry chain multiplexers can be selectively configured as AND or OR gates to facilitate certain arithmetic or comparison functions for the outputs of a plurality of function generators.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: July 30, 2002
    Assignee: Xilinx, Inc.
    Inventors: Kenneth D. Chapman, Steven P. Young
  • Patent number: 6167545
    Abstract: A method and software apparatus are provided for implementing a dynamically modifiable test flow for integrated circuit devices that adapts to the characteristics of each processed device lot. According to the method of the invention, a modified set of tests sufficient to ensure proper device function for a particular lot is performed, reducing test costs and increasing test capacity. The method and system of the invention periodically samples a predetermined sample number of devices using a full set of tests including a set of skippable tests. Depending upon the performance characteristics of the sample device group on the skippable tests, a number of skippable tests are skipped during a modified test flow. After a next set of devices is tested using the modified test flow, the full set of tests is again performed on another sample group, and the size and makeup of the modified test flow is adjusted according to the new results.
    Type: Grant
    Filed: March 19, 1998
    Date of Patent: December 26, 2000
    Assignee: Xilinx, Inc.
    Inventors: Mihai G. Statovici, Ronald J. Mack