Patents by Inventor David I. Lawrie

David I. Lawrie 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: 9065482
    Abstract: Approaches are disclosed for encoding N symbols of a sequence in parallel using an R parity symbol encoding algorithm. A first symbol matrix is added to a first parity matrix over a finite field to produce a first intermediate matrix. The first intermediate matrix is multiplied by at least a first coefficient matrix and a second coefficient matrix over the finite field to produce a second intermediate matrix. A second symbol matrix is multiplied by at least the second coefficient matrix to produce a third intermediate matrix. The second and third intermediate matrices are added to produce a revised parity matrix.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: June 23, 2015
    Assignee: XILINX, INC.
    Inventors: Graham Johnston, David I. Lawrie
  • Patent number: 9003266
    Abstract: In one embodiment, a method of block decoding is provided. For each of a plurality of data blocks input to a memory arrangement, a plurality of decoding iterations are performed using a circular pipeline of processing stages. For each decoding iteration, one processing stage of the circular pipeline performs a first set and a second set of soft-input-soft-output (SISO) decoding operations on a block of data. The first set of SISO decoding operations produces an intermediate block of data. The second set of SISO decoding operations is performed on the intermediate data block to complete the one decoding iteration. The next decoding iteration of the plurality of decoding iterations is performed using the next processing stage following the one processing stage of the circular pipeline of processing stages.
    Type: Grant
    Filed: April 15, 2011
    Date of Patent: April 7, 2015
    Assignee: Xilinx, Inc.
    Inventors: Colin Stirling, David I. Lawrie, David Andrews
  • Patent number: 8843807
    Abstract: In one embodiment, a circular pipeline processing system is provided. The system includes a plurality of processing stages configured to operate in a circular pipeline. Each processing stage is configured to output a fully processed data block in response to completing a final processing iteration, and otherwise, store a partially processed data block in a memory buffer of the processing stage. Each processing stage is configured to select between an unprocessed data block and a partially processed data block from the memory buffer of a preceding processing stage, based on one or more of availability of memory sufficient for storage of an unprocessed data block or availability of a partially processed data block. The processing stage is configured to process the selected data block.
    Type: Grant
    Filed: August 18, 2011
    Date of Patent: September 23, 2014
    Assignee: Xilinx, Inc.
    Inventors: Colin Stirling, David I. Lawrie, David Andrews
  • Patent number: 8332735
    Abstract: A method for decoding an encoded message is described. The method includes obtaining a set of metrics which includes first and second state metrics, and first and second branch metrics. First and second offset values for the iteration are obtained. The first state and branch metrics are added together to obtain a first partial result. The second state and branch metrics are added together to obtain a second partial result. The second partial result is subtracted from the first partial result to obtain a difference. The first partial result and the first offset value are added together to obtain a first result. The second partial result and the second offset value are added together to obtain a second result. Either the first result or the second result is selected for output responsive to the difference. A log correction term is selected responsive to the difference.
    Type: Grant
    Filed: March 9, 2009
    Date of Patent: December 11, 2012
    Assignee: Xilinx, Inc.
    Inventors: David Andrews, David I. Lawrie, Colin Stirling
  • Patent number: 8219782
    Abstract: Address generation by an integrated circuit is described. An aspect relates generally to an address generator which has first and second processing units. The second processing unit is coupled to receive a stage output from the first processing unit and configured to provide an address output. The stage output is in a first range, and the address output is in a second range. The first range is from ?K to ?1 for K a block size, and the second range is from 0 to K?1.
    Type: Grant
    Filed: September 18, 2008
    Date of Patent: July 10, 2012
    Assignee: Xilinx, Inc.
    Inventors: Colin Stirling, David I. Lawrie, David Andrews
  • Patent number: 7904761
    Abstract: A method and apparatus for the generation of discrete power series values (PSVs) and associated PSV addresses. Repeated evaluations of a discrete power series are performed by a reduced complexity PSV generator, such that the need for multiplication operations is obviated. Each evaluation cycle performed by the reduced complexity PSV generator is modified by each primitive root of the desired discrete power series. For each PSV generated, a corresponding address is calculated to indicate the correct placement of the PSV generated.
    Type: Grant
    Filed: March 24, 2006
    Date of Patent: March 8, 2011
    Assignee: Xilinx, Inc.
    Inventors: Jeffrey Allan Graham, David I Lawrie
  • Patent number: 7895507
    Abstract: An Add-Compare-Select circuit for use with a trellis decoder can include a first module and a second module. The first module can provide a difference signal specifying an indication of a difference between a second path cost and a first path cost of a trellis. The second path cost can be a sum of a second state cost and a second branch metric and the first path cost can be a sum of a first state cost and a first branch metric. The second module can select the first path cost or the second path cost as a new cost according to the difference signal of the first module.
    Type: Grant
    Filed: February 16, 2007
    Date of Patent: February 22, 2011
    Assignee: Xilinx, Inc.
    Inventors: Elizabeth R. Cowie, David I. Lawrie
  • Patent number: 7810010
    Abstract: A Turbo Code decoder for implementation in an integrated circuit is described. An add-compare select (“ACS”) unit is configured to provide a difference between first and second outputs and to select one of the first and second outputs responsive to a difference thereof. An initialization stage is coupled to receive and configured to store for example the first output selected as an initialization value. A second select stage is coupled to receive for example the first output selected from the first select stage and coupled to obtain the initialization value stored from the initialization stage. The second select stage is configured to output either the first output selected from the ACS unit or the initialization value from the initialization stage.
    Type: Grant
    Filed: May 24, 2006
    Date of Patent: October 5, 2010
    Assignee: Xilinx, Inc.
    Inventor: David I. Lawrie
  • Publication number: 20100070737
    Abstract: Address generation by an integrated circuit is described. An aspect relates generally to an address generator which has first and second processing units. The second processing unit is coupled to receive a stage output from the first processing unit and configured to provide an address output. The stage output is in a first range, and the address output is in a second range. The first range is from ?K to ?1 for K a block size, and the second range is from 0 to K-1.
    Type: Application
    Filed: September 18, 2008
    Publication date: March 18, 2010
    Applicant: XILINX, INC.
    Inventors: Colin Stirling, David I. Lawrie, David Andrews
  • Patent number: 7613990
    Abstract: A circuit for a multi-channel add-compare-select unit is disclosed. The circuit includes a compare unit and a datapath. The datapath is coupled to the compare unit, and includes a number of adder units, a selection unit (which is coupled to the adder units), and a number of clocked storage stages.
    Type: Grant
    Filed: November 18, 2003
    Date of Patent: November 3, 2009
    Assignee: Xilinx, Inc.
    Inventors: William A. Wilkie, David I. Lawrie, Elizabeth R. Cowie