Patents by Inventor Peter Hofstee

Peter Hofstee 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: 7484187
    Abstract: Given a function F of a circuit having a data latching device and a feedback loop feeding an output Q of the device into logic which feeds the device, a method includes extracting at least one data independent case and clock-gating the device with the at least one data independent case. The method also includes eliminating the feedback loop if function F depends only on Q with a positive polarity or leaving the feedback loop if function F depends on Q in both positive and negative polarities.
    Type: Grant
    Filed: December 7, 2005
    Date of Patent: January 27, 2009
    Assignee: International Business Machines Corporation
    Inventors: Cynthia Rae Eisner, Peter Hofstee, Alexander Itskovich, Daniel Lawrence Stasiak
  • Patent number: 7146371
    Abstract: A data structure and corresponding search methods are disclosed for improving the performance of table lookups. A data structure for the table is employed using a single hash table with hash table entries pointing to tree fragments that are contiguous in main memory and can be efficiently loaded into a local data store or cache. Decision nodes are stored in a contiguous block of memory in a relative position based on the position of the decision node in the tree structure, including blank positions. Leaf nodes are stored in a contiguous block of memory based on the position of the leaf node in the tree structure, concatenating leaf nodes to eliminate blank positions. Leaf nodes of the tree fragments contain indicia of a data record, or indicia of another tree fragment. The data structure and corresponding search algorithm are employed for searches based on a longest prefix match in an internet routing table.
    Type: Grant
    Filed: December 5, 2002
    Date of Patent: December 5, 2006
    Assignee: International Business Machines Corporation
    Inventors: Peter Hofstee, Marc C. Necker
  • Patent number: 6518793
    Abstract: The present invention relates to improvements concerning logic and timing verification as the testability of a hardware circuit comprising embeddings of dynamic logic circuits in a static environment. The clocked macros comprising the dynamic logic circuit are bounded at both input and output by latches, keeping input and output signals to the clocked macro static. The static input signals are processed with wave formatting means in order to generate a wave form usable for an evaluation by the dynamic logic circuit, and the dynamic logic output signal is converted back to a static signal by a set/reset latch such that it can be latched by the clock signal of the static embedding circuit. Thus, the analysis methods for timing and logic simulation during chip design can be the same as those used for static logic and, in particular, the LSSD testing methods can be used.
    Type: Grant
    Filed: March 22, 2001
    Date of Patent: February 11, 2003
    Assignee: International Business Machines Corporation
    Inventors: Jens Leenstra, Hans-Werner Tast, Dieter Wendel, Peter Hofstee
  • Publication number: 20010026172
    Abstract: The present invention relates to improvements concerning logic and timing verification as the testability of a hardware circuit comprising embeddings of dynamic logic circuits in a static environment. The clocked macros comprising the dynamic logic circuit are bounded at both input and output by latches, keeping input and output signals to the clocked macro static. The static input signals are processed with wave formatting means in order to generate a wave form usable for an evaluation by the dynamic logic circuit, and the dynamic logic output signal is converted back to a static signal by a set/reset latch such that it can be latched by the clock signal of the static embedding circuit. Thus, the analysis methods for timing and logic simulation during chip design can be the same as those used for static logic and, in particular, the LSSD testing methods can be used.
    Type: Application
    Filed: March 22, 2001
    Publication date: October 4, 2001
    Applicant: International Business Machines Corporation
    Inventors: Jens Leenstra, Hans-Werner Tast, Dieter Wendel, Peter Hofstee