Patents by Inventor John D. Villasenor

John D. Villasenor 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: 8549630
    Abstract: A method of securing bus architecture from a Trojan attack. A restricted address access detector generates an unauthorized access detection signal when a master ID signal is within a restricted range. The unauthorized access detection signal disables the requested slave select signal, and the address decoder instead outputs a default slave select signal. A counter determines the duration of a lock signal from a master, and a comparator activates a malicious bus lock signal if the lock signal duration exceeds a threshold. The master mask register forcibly gates the lock signal upon receipt of the malicious bus lock signal. If the duration of a wait request from a slave exceeds a maximum duration register value, a comparator activates a malicious wait detection signal to disable the wait request signal. The method might include storing identifying information about the malicious master and storing a slave ID corresponding to the malicious slave.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: October 1, 2013
    Assignee: The Regents of the University of California
    Inventors: John D Villasenor, Lok Won Kim
  • Publication number: 20110225651
    Abstract: A method of securing bus architecture from a Trojan attack. A restricted address access detector generates an unauthorized access detection, signal when a master ID signal is within a restricted range. The unauthorized access detection signal disables the requested slave select signal, and the address decoder instead outputs a default slave select signal. A counter determines the duration of a lock signal from a master, and a comparator activates a malicious bus lock signal if the lock signal duration exceeds a threshold. The master mask register forcibly gates the lock signal upon receipt of the malicious bus lock signal. If the duration of a wait request from a slave exceeds a maximum duration register value, a comparator activates a malicious wait detection signal to disable the wait request signal. The method might include storing identifying information about the malicious master and storing a slave ID corresponding to the malicious slave.
    Type: Application
    Filed: March 7, 2011
    Publication date: September 15, 2011
    Inventors: John D. Villasenor, Lok Won Kim
  • Patent number: 7532669
    Abstract: A video coding-decoding (CODEC) method in an error resilient mode, a computer readable medium having a computer program for the video CODEC method, and a video CODEC apparatus. The video CODEC method provides more resilience against channel error such that communications are less affected by error under conditions in which errors are a serious problem such as in a wireless communications channel. In the video CODEC method, a header data part (HDP) bit region, a motion vector data part (MVDP) bit region and a discrete cosine transform data part (DDP) bit regions are partitioned from each macro block of the video data in an error resilient mode, and then the partitioned bit regions are variable-length-coded. Then, the bit regions selected from the variable-length coded bit regions according to a predetermined priority for recovery are reversible-variable-length-coded, and markers are then inserted into the variable-length coded or reversible-variable-length-coded bit regions.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: May 12, 2009
    Assignees: Samsung Electronics Co., Ltd., University of California
    Inventors: Jiangtao Wen, John D. Villasenor, Jeong-hoon Park
  • Patent number: 7340671
    Abstract: The present invention includes a technique for updating messages that originate at the constraint nodes of bi-partite graphs in Low Density Parity Check codes. The technique computes only two outgoing magnitudes at each constraint node and exhibits no measurable performance loss as compared to exact belief propagation which computes a unique magnitude for each departing edge from a given constraint node. The technique eliminates the need for memory based table look-up in the constraint node processing and has been implemented, in one embodiment, using only shift, add, and comparison operations.
    Type: Grant
    Filed: October 8, 2004
    Date of Patent: March 4, 2008
    Assignee: Regents of the University of California
    Inventors: Christopher R. Jones, John D. Villasenor
  • Patent number: 7177355
    Abstract: A method of representing encoding or non-encoding by extending a video information field of a block when coding video information, is provided. The method of representing encoding or non-encoding by extending an information field for representing encoding or non-encoding is applied to an error allowable mode. Also, the amount of bits depending on the characteristics of video information to be encoded can be reduced. In this method, an image is encoded by extending a code (COD) field which is used in H.263 and MPEG-4 to indicate the cases where neither a motion vector (MV) nor a discrete cosine transform (DCT) value are encoded, where both the MV and the DCT value are encoded, and where only the MV is encoded. Therefore, in a channel with errors, the extended OCD field can be used in the error allowable mode. Also, video information can be encoded using a smaller amount of bits where the motion of an image is constant, than in the conventional art.
    Type: Grant
    Filed: December 1, 1998
    Date of Patent: February 13, 2007
    Assignees: Samsung Electronics Co., Ltd., The Regents of the University of California
    Inventors: Jiangtao Wen, John D. Villasenor, Jeong-hoon Park
  • Patent number: 6768775
    Abstract: A video coding-decoding (CODEC) method in an error resilient mode, a computer readable medium having a computer program for the video CODEC method, and a video CODEC apparatus. The video CODEC method provides more resilience against channel error such that communications are less affected by error under conditions in which errors are a serious problem such as in a wireless communications channel. In the video CODEC method, a header data part (HDP) bit region, a motion vector data part (MVDP) bit region and a discrete cosine transform data part (DDP) bit regions are partitioned from each macro block of the video data in an error resilient mode, and then the partitioned bit regions are variable-length-coded. Then, the bit regions selected from the variable-length coded bit regions according to a predetermined priority for recovery are reversible-variable-length-coded, and markers are then inserted into the variable-length coded or reversible-variable-length-coded bit regions.
    Type: Grant
    Filed: December 1, 1998
    Date of Patent: July 27, 2004
    Assignees: Samsung Electronics Co., Ltd., The Regents of the University of California
    Inventors: Jiangtao Wen, John D. Villasenor, Jeong-hoon Park
  • Publication number: 20030128755
    Abstract: A video coding-decoding (CODEC) method in an error resilient mode, a computer readable medium having a computer program for the video CODEC method, and a video CODEC apparatus. The video CODEC method provides more resilience against channel error such that communications are less affected by error under conditions in which errors are a serious problem such as in a wireless communications channel. In the video CODEC method, a header data part (HDP) bit region, a motion vector data part (MVDP) bit region and a discrete cosine transform data part (DDP) bit regions are partitioned from each macro block of the video data in an error resilient mode, and then the partitioned bit regions are variable-length-coded. Then, the bit regions selected from the variable-length coded bit regions according to a predetermined priority for recovery are reversible-variable-length-coded, and markers are then inserted into the variable-length coded or reversible-variable-length-coded bit regions.
    Type: Application
    Filed: February 28, 2003
    Publication date: July 10, 2003
    Applicant: SAMSUNG ELECTRONICS CO., LTD., UNIVERSITY OF CALIFORNIA
    Inventors: Jiangtao Wen, John D. Villasenor, Jeong-Hoon Park
  • Patent number: 6426976
    Abstract: A motion vector prediction method in an error resilient mode. In the motion vector prediction method capable of decoding backwards, motion vectors of macro blocks are calculated, and motion vectors of macro blocks each having one motion vector are predicted while moving to another macro block from left to right, and motion vectors of macro blocks each having four motion vectors are continuously predicted in a predetermined sequence to have correlation in prediction of the four motion vectors. Thus, in the motion vector prediction method based on the image signal compression method of the MPEG-4 or H.263 standard, the motion vector prediction is performed with continuity and correlation among the motion vectors, so that two-way decoding is possible during transmission of blocks with a predetermined packet, resulting in better error resilient characteristics.
    Type: Grant
    Filed: December 1, 1998
    Date of Patent: July 30, 2002
    Assignees: Samsung Electronics Co., Ltd., Regents of the University of California
    Inventors: Jiangtao Wen, John D. Villasenor, Jeong-hoon Park, Dong-seek Park
  • Patent number: 5818877
    Abstract: A method generates a reduced number of values representing a sequence of grouped data values and partitions the reduced number of values by first mapping data values into groups of symbols and then partitioning the resulting stream of symbols. The digits representing the first data value in each group are replaced with symbols from a first alphabet. The most significant digit of the second data value in each group and the sign of that second data value are also represented by a symbol from the first symbol set, while the remaining significant bits of the second data value in each group are represented by symbols from a second symbol set. A stream of symbols which represent a sequence of grouped data values is partitioned into first partition symbol groups and second partition symbol groups. Each first partition symbol group comprises the symbols representing the first data value in each group and also the symbol representing the least significant bit of the second data value which follows.
    Type: Grant
    Filed: March 26, 1996
    Date of Patent: October 6, 1998
    Assignee: The Regents of the University of California
    Inventors: Min-Jen Tsai, John D. Villasenor, Feng Chen
  • Patent number: RE40372
    Abstract: A motion vector prediction method in an error resilient mode. In the motion vector prediction method capable of decoding backwards, motion vectors of macro blocks are calculated, and motion vectors of macro blocks each having one motion vector are predicted while moving to another macro block from left to right, and motion vectors of macro blocks each having four motion vectors are continuously predicted in a predetermined sequence to have correlation in prediction of the four motion vectors. Thus, in the motion vector prediction method based on the image signal compression method of the MPEG-4 or H.263 standard, the motion vector prediction is performed with continuity and correlation among the motion vectors, so that two-way decoding is possible during transmission of blocks with a predetermined packet, resulting in better error resilient characteristics.
    Type: Grant
    Filed: June 8, 2004
    Date of Patent: June 10, 2008
    Assignees: Samsung Electronics Co., Ltd., University of California
    Inventors: Jiangtao Wen, John D. Villasenor, Jeong-hoon Park, Dong-seek Park