Patents Represented by Attorney Timothy Markison
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Patent number: 7515668Abstract: 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: GrantFiled: January 26, 2005Date of Patent: April 7, 2009Assignee: XILINX, Inc.Inventor: Shahriar Rokhsaz
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Patent number: 7466787Abstract: 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: GrantFiled: November 19, 2004Date of Patent: December 16, 2008Assignee: Xilinx, Inc.Inventor: James P. Ross
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Patent number: 7142823Abstract: 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: GrantFiled: January 29, 2004Date of Patent: November 28, 2006Assignee: Xilinx, Inc.Inventors: John D. Logue, Austin H. Lesea, Wei Lu
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Patent number: 7142622Abstract: 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: GrantFiled: April 22, 2003Date of Patent: November 28, 2006Assignee: XILINX, Inc.Inventors: Brian T. Brunn, Ahmed Younis
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Patent number: 6977959Abstract: 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: GrantFiled: January 17, 2003Date of Patent: December 20, 2005Assignee: Xilinx, Inc.Inventors: Brian T. Brunn, Ahmed Younis, Shahriar Rokhsaz
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Patent number: 6956905Abstract: 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: GrantFiled: March 23, 2000Date of Patent: October 18, 2005Assignee: Xilinx, Inc.Inventor: Shahriar Rokhsaz
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Patent number: 6927608Abstract: 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: GrantFiled: September 5, 2003Date of Patent: August 9, 2005Assignee: Xilinx, Inc.Inventors: Mingdeng Chen, Michael A. Nix
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Patent number: 6886092Abstract: 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: GrantFiled: November 19, 2001Date of Patent: April 26, 2005Assignee: Xilinx, Inc.Inventors: Stephen M. Douglass, Ahmad R. Ansari
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Patent number: 6812870Abstract: 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: GrantFiled: September 11, 2003Date of Patent: November 2, 2004Assignee: Xilinx, Inc.Inventors: Joseph Neil Kryzak, Charles W. Boecker
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Patent number: 6809676Abstract: 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: GrantFiled: August 20, 2002Date of Patent: October 26, 2004Assignee: Xilinx, Inc.Inventors: Ahmed Younis, Marwan M. Hassoun, Moises E. Robinson
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Patent number: 5247734Abstract: 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: GrantFiled: November 9, 1992Date of Patent: September 28, 1993Assignee: Motorola, Inc.Inventors: John N. Lubbe, Lester J. Onyszko, Raul Olivera
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Patent number: 5126733Abstract: 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: GrantFiled: May 17, 1989Date of Patent: June 30, 1992Assignee: Motorola, Inc.Inventors: Richard C. Sagers, Jack Boggs Butler