Patents Represented by Attorney Timothy Markison
  • Patent number: 7515668
    Abstract: A method for correcting sampling offset of a clock and data recovery circuit begins for consecutive data bits having a transition there between by sampling, using an edge sampling point, the transition to produce a sampled transition. The method continues by determining whether the sampled transition is of an intermediate value. The method continues when the sampled transition is not of the intermediate value, by adjusting sampling position of incoming data of the clock and data recovery circuit.
    Type: Grant
    Filed: January 26, 2005
    Date of Patent: April 7, 2009
    Assignee: XILINX, Inc.
    Inventor: Shahriar Rokhsaz
  • Patent number: 7466787
    Abstract: A multi-stage phase detector (four stages in one described embodiment) comprises a plurality of data paths and phase paths that are buffered from a received serial data input stream to reduce loading. Each data path recovers a data bit and further functions as a transition detector to detect consecutive data bits having similar logic states. An exclusive NOR gate in the data path produces a control signal to disable a multiplexer in the phase path when two data bits have similar logic states. Each phase path produces a sample of a serial data input stream and produces the sample to a multiplexer for coupling to a transconductance module. The multiplexer output is coupled to or decoupled from the transconductance module by the control signal from the data path to maintain phase-lock.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: December 16, 2008
    Assignee: Xilinx, Inc.
    Inventor: James P. Ross
  • Patent number: 7142823
    Abstract: A low jitter digital frequency synthesizer includes a first counter module, a second counter module, a snapshot module, an error value generation module, and a tapped delay line. The first counter module counts intervals of M cycles of an input clock to produce a first count. The second counter module count intervals of D cycles of an output clock to produce a second count, wherein a rate of the output clock corresponds to M/D times a rate of the input clock. The snapshot module periodically takes a snapshot of the first and second counts to produce snapshots. The error value generation module generates an error value based on the snapshots. The tapped delay line module produces the output clock based on the error value.
    Type: Grant
    Filed: January 29, 2004
    Date of Patent: November 28, 2006
    Assignee: Xilinx, Inc.
    Inventors: John D. Logue, Austin H. Lesea, Wei Lu
  • Patent number: 7142622
    Abstract: A multiplying phase detector includes a 1st multiplier, a 2nd multiplier and a phase error generation module. The 1st multiplier is operably coupled to multiple an incoming data stream, which is a random data pattern, with a 1st clock, which is in-phase with the incoming stream of data and is one-half the rate of the incoming stream of data, to produce a 1st product. In this instance, the 1st product represents missing transitions in the incoming stream of data. The 2nd multiplier is operably coupled to multiply the 1st product with the incoming data stream to produce a modified stream of data. The phase error generation module is operably coupled to generate a phase error based on the modified stream of data and a 2nd clock, where the phase error represents a phase offset between the modified stream of data and the 2nd clock.
    Type: Grant
    Filed: April 22, 2003
    Date of Patent: November 28, 2006
    Assignee: XILINX, Inc.
    Inventors: Brian T. Brunn, Ahmed Younis
  • Patent number: 6977959
    Abstract: A clock recovery circuit that operates at a clock speed equal to one-half the input data rate is presented. The clock recovery circuit uses dual input latches to sample the incoming serial data on both the rising edge and falling edge of a half-rate clock signal to provide equivalent full data rate clock recovery. The clock recovery circuit functions to maintain the half-rate clock transitions in the center of the incoming serial data bits. The clock recovery circuit includes a phase detector, charge pump, controlled oscillation module and a feedback module. The phase detector produces information on the phase and data transitions in the incoming data signal to the charge pump. Generally, the circuit is delay insensitive and receives phase and transition information staggered relative to each other.
    Type: Grant
    Filed: January 17, 2003
    Date of Patent: December 20, 2005
    Assignee: Xilinx, Inc.
    Inventors: Brian T. Brunn, Ahmed Younis, Shahriar Rokhsaz
  • Patent number: 6956905
    Abstract: A balanced peak detector circuit adjusts differential voltage signals. In one embodiment, the peak detector uses competing current paths to provide a charging current to a storage capacitor. The charge on the storage capacitor is used to adjust either a transconductance or a transimpedance circuit. An offset current can be used to adjust the charge stored on the capacitor to change a peak-to-peak output voltage from the transimpedance circuit. In one embodiment, the offset current can be adjusted using an adjustable current source. A discharge circuit has been describe that allows a discharge of the capacitor to be controlled.
    Type: Grant
    Filed: March 23, 2000
    Date of Patent: October 18, 2005
    Assignee: Xilinx, Inc.
    Inventor: Shahriar Rokhsaz
  • Patent number: 6927608
    Abstract: A low power LVDS driver includes a switchable current module, a source termination circuit, a transistor section, and a load current source. The switchable current module is operably coupled to produce a first current when a differential input signal is in a first state and to produce a second current when the differential input signal is in a second state. The source termination circuit is operably coupled in parallel with a load. The transistor section is operably coupled to receive the first and second currents from the switchable current module via at least one of the source termination circuit and the load, wherein the transistor section produces an LVDS output signal based on the first and second currents, the differential input signal, and the source termination circuit. The load current source is operably coupled to sink the first and second currents from the transistor section.
    Type: Grant
    Filed: September 5, 2003
    Date of Patent: August 9, 2005
    Assignee: Xilinx, Inc.
    Inventors: Mingdeng Chen, Michael A. Nix
  • Patent number: 6886092
    Abstract: A method and apparatus for processing data within a programmable gate array begins when a fixed logic processor that is embedded within the programmable gate array detects a custom operation code. The processing continues when the fixed logic processor provides an indication of the custom operational code to the programmable gate array. The processing continues by having at least a portion of the programmable gate array, which is configured as a dedicated processor, performing a fixed logic routine upon receiving the indication from the fixed logic processor.
    Type: Grant
    Filed: November 19, 2001
    Date of Patent: April 26, 2005
    Assignee: Xilinx, Inc.
    Inventors: Stephen M. Douglass, Ahmad R. Ansari
  • Patent number: 6812870
    Abstract: 8b/10b encoding begins when an input running disparity is received. The processing then continues by receiving an 8-bit digital input that includes a 5-bit digital input portion and a 3-bit digital input portion. The processing then continues by determining, in parallel, a 6-bit running disparity and a 4-bit running disparity. The processing then continues by determining a 6-bit digital output based on the 6-bit running disparity and the 5-bit digital input portion. The processing then continues by determining a 4-bit digital output based on the 4-bit running disparity and the 3-bit digital input portion. The resulting 10-bit encoded digital output is the combination of the 6-bit digital output and the 4-bit digital output.
    Type: Grant
    Filed: September 11, 2003
    Date of Patent: November 2, 2004
    Assignee: Xilinx, Inc.
    Inventors: Joseph Neil Kryzak, Charles W. Boecker
  • Patent number: 6809676
    Abstract: A VCO (110) can be configured to convert an analog input signal (105) to a digital output signal (125). In accordance with the inventive arrangements, the VCO can convert the analog input signal to at least one intermediate signal (130) having a frequency dependent on the analog input signal. A frequency detector (115) can be configured to determine a frequency of at least one intermediate signal. Subsequently, a mapping circuit (120) can be configured to map the determined frequency of the at least one intermediate signal to an output value representing the digital output signal (125).
    Type: Grant
    Filed: August 20, 2002
    Date of Patent: October 26, 2004
    Assignee: Xilinx, Inc.
    Inventors: Ahmed Younis, Marwan M. Hassoun, Moises E. Robinson
  • Patent number: 5247734
    Abstract: A first heat sink member with extension slots and component detailing is cast from a thermally conductive material. Fin members are constructed from a similar, but not necessarily identical, thermally conductive material. The fin members are constructed so that they will mate with the extension slots of the first heat sink member. Positioned in alignment with the extension slots to the first heat sink member, the fin members are attached with a thermally conductive bonding agent.
    Type: Grant
    Filed: November 9, 1992
    Date of Patent: September 28, 1993
    Assignee: Motorola, Inc.
    Inventors: John N. Lubbe, Lester J. Onyszko, Raul Olivera
  • Patent number: 5126733
    Abstract: A trunked communication system that supports polling requests for location information without requiring infrastructure changes. Ordinary private call talk requests are altered to include at least two inclusions of the ID code for the target communication unit. This dual representation of the ID is interpreted by the receiving unit as a poll request, to which the unit responds by providing location information on an allocated communication resource.
    Type: Grant
    Filed: May 17, 1989
    Date of Patent: June 30, 1992
    Assignee: Motorola, Inc.
    Inventors: Richard C. Sagers, Jack Boggs Butler