Patents by Inventor Shahriar Rokhsaz
Shahriar Rokhsaz 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).
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Patent number: 7523215Abstract: A method and apparatus for a transmitting entity within a micro-area network to establish a data transmission within the network includes processing that begins by determining the identity of a target entity within the micro-area network. The processing then continues by determining transmission characteristics of at least one communication path between the transmitting entity and target entity of the micro-area network. The processing then continues by determining a transmission convention based on the transmission characteristics. The processing then continues by providing the transmission convention to the target entity.Type: GrantFiled: January 14, 2002Date of Patent: April 21, 2009Assignee: Xilinx, Inc.Inventors: Moises E. Robinson, Shahriar Rokhsaz, Jinghui Lu
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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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Publication number: 20080116990Abstract: A method and apparatus for dynamically varying the impedance of a tank circuit whereby, over time, the response of the circuit to a received signal is maximized.Type: ApplicationFiled: November 18, 2006Publication date: May 22, 2008Inventor: Shahriar Rokhsaz
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Patent number: 7315220Abstract: A voltage controlled oscillator (VCO) having a single stage ring-oscillator having both coarse and fine control of the frequency of oscillation is described. In an embodiment the VCO may include a first n-channel latch having a first output and a second output; a first P-channel transistor coupled between a voltage supply and a first VCO output, where a gate of the first P-channel transistor is coupled to the first output of the first n-channel latch; a first programmable resistor circuit coupled between the first VCO output and the first output of the first n-channel latch; and a second n-channel latch coupled to the first VCO output.Type: GrantFiled: January 27, 2006Date of Patent: January 1, 2008Assignee: Xilinx, Inc.Inventors: Moises E. Robinson, Shahriar Rokhsaz, Marwan M. Hassoun, Earl E. Swartzlander, Jr.
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Patent number: 7254140Abstract: A method and apparatus for transceiving data in a micro-area network includes processing that begins by obtaining a data unit for transmission by a first data transceiving entity of a micro area network. The processing then continues when the first data transceiving entity formats the payload data using a first transmission format convention. The first data transceiving entity also formats the overhead data using a second transmission formatting convention to produce formatted overhead data. The formatting of the overhead data and/or payload data may include encoding and/or modulating the data. The processing continues when the first data transceiving entity transmits the formatted payload data and the formatted overhead data to at least one target entity within the micro-area network. The process continues when a target entity receives the formatted payload data and the formatted overhead data.Type: GrantFiled: January 14, 2002Date of Patent: August 7, 2007Assignee: XILINX, Inc.Inventors: Shahriar Rokhsaz, Jinghui Lu, Moises E. Robinson
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Patent number: 7224760Abstract: A high-speed, wide bandwidth data detection circuit includes a phase detection module, a data detection module, a loop filter, and a voltage controlled oscillator. The phase detection module is operably coupled to produce a controlled current based on a current mode mathematical manipulation of differences between an incoming data stream and a recovered clock. The phase detection module performs the current mode mathematical manipulations and produces the controlled current in the current domain. The data detection module is operably coupled to produce the detected data based on the incoming data stream and the recovered clock. The loop filter is operably coupled to convert the controlled current into a controlled voltage. The voltage controlled oscillator is operably coupled to convert the control voltage into the recovered clock.Type: GrantFiled: April 22, 2003Date of Patent: May 29, 2007Assignee: Xilinx, Inc.Inventors: Shahriar Rokhsaz, Moises E. Robinson, Ahmed Younis, Brian T. Brunn
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Patent number: 7058120Abstract: A transceiver includes a receiver section and a transmitter section. The receiver section includes a clocking circuit, a serial-to-parallel module, and compensation. The transmitter section includes a clocking circuit, parallel-to-serial module, and compensation. The compensation within the receiver section and transmitter section compensates for integrated circuit (IC) processing limits and/or integrated circuit (IC) fabrication limits within the clocking circuits, serial-to-parallel module, and parallel-to-serial module that would otherwise limit the speed at which the transceiver could transport data.Type: GrantFiled: January 18, 2002Date of Patent: June 6, 2006Assignee: Xilinx, Inc.Inventors: Jinghui Lu, Shahriar Rokhsaz, Stephen D. Anderson, Michael A. Nix, Ahmed Younis, Michael Ren Kent, Yvette P. Lee, Firas N. Abughazaleh, Brian T. Brunn, Moises E. Robinson, Kazi S. Hossain
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Patent number: 6995611Abstract: An inductive amplifier having a feed forward boost is provided, thereby improving the gain of the inductive amplifier at frequencies greater than 1 GigaHertz. The inductive amplifier includes a feed-forward boost circuit coupled to intermediate nodes of an inductive amplifier circuit, whereby the feed-forward boost circuit generates boost currents that are added to the currents of the inductive amplifier circuit. In one embodiment, the feed-forward boost circuit includes a boost current supply, a first boost transistor coupled between the current supply and a first intermediate node of the inductive amplifier circuit, and a second boost transistor coupled between the current supply and a second intermediate node of the inductive amplifier circuit. In one embodiment, the first and second boost transistors and the inductive amplifier circuit are controlled by the same differential input signals.Type: GrantFiled: October 14, 2003Date of Patent: February 7, 2006Assignee: Xilinx, Inc.Inventor: Shahriar Rokhsaz
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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: 6956923Abstract: A high speed phase detector circuit operating at a clock speed equal to one-half an input data rate (i.e. a half-rate clock) provides phase information and transition information from incoming serial data. The high speed phase detector circuit samples the incoming serial data on both the rising edge and falling edge of the half-rate clock to provide equivalent full high speed data rate sampling. The high speed phase detector circuit generates a delay between the phase information and the transition information. The phase information is produced in a first bit period and the transition information is produced in a second bit period relative to the first bit period.Type: GrantFiled: April 22, 2003Date of Patent: October 18, 2005Assignee: Xilinx, Inc.Inventors: Ahmed Younis, Shahriar Rokhsaz
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Publication number: 20040141577Abstract: 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: ApplicationFiled: January 17, 2003Publication date: July 22, 2004Applicant: Xilinx, Inc.Inventors: Brian T. Brunn, Ahmed Younis, Shahriar Rokhsaz
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Patent number: 6670847Abstract: An inductive amplifier having a feed forward boost is provided, thereby improving the gain of the inductive amplifier at frequencies greater than 1 GigaHertz. The inductive amplifier includes a feed-forward boost circuit coupled to intermediate nodes of an inductive amplifier circuit, whereby the feed-forward boost circuit generates boost currents that are added to the currents of the inductive amplifier circuit. In one embodiment, the feed-forward boost circuit includes a boost current supply, a first boost transistor coupled between the current supply and a first intermediate node of the inductive amplifier circuit, and a second boost transistor coupled between the current supply and a second intermediate node of the inductive amplifier circuit. In one embodiment, the first and second boost transistors and the inductive amplifier circuit are controlled by the same differential input signals.Type: GrantFiled: January 18, 2002Date of Patent: December 30, 2003Assignee: Xilinx, Inc.Inventor: Shahriar Rokhsaz
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Patent number: 6566950Abstract: A high-speed, low distortion line driver that includes an amplifying circuit and a differential input amplifier. The differential input amplifier includes a 1st amplifying transistor, a 2nd amplifying transistor, a 1st controlled current source, and a 2nd controlled current source. The 1st amplifying transistor is coupled in series with the 1st controlled current source and the 2nd amplifying transistor is coupled in series with the 2nd controlled current source. The 1st and 2nd amplifying transistors are operably coupled to receive a differential input signal and provide a gained and level shifted representation of the differential input signal based on the controlled currents provided by the 1st and 2nd current sources. The amount of gain is based on the transconductance properties of the 1st and 2nd amplifying transistors and of the 1st and 2nd current sources.Type: GrantFiled: October 29, 2001Date of Patent: May 20, 2003Assignee: Xilinx, Inc.Inventor: Shahriar Rokhsaz
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Patent number: 6504432Abstract: A tunable differential amplifier includes an amplifier circuit, a current mirror, a dynamic current regulator, and a dynamic output common mode regulator. The current mirror is operably coupled to the amplifier circuit and controls the current flowing through each leg of the amplifier circuit. The current through the current mirror is established based on a regulated current provided by the dynamic current regulator and a common mode error current signal provided by the dynamic output common mode regulator. The common mode error signal is representative of an error between the desired output common mode of the amplifier circuit and the actual common mode of the output of the amplifier circuit. The regulated current is based on the common mode of the input of the amplifier circuit. As such, the biasing current and the common mode output of the differential amplifier is dynamically regulated.Type: GrantFiled: March 30, 2001Date of Patent: January 7, 2003Assignee: Xilinx, Inc.Inventor: Shahriar Rokhsaz
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Patent number: 6377122Abstract: A high-speed, low distortion line driver that includes an amplifying circuit and a differential input amplifier. The differential input amplifier includes a 1st amplifying transistor, a 2nd amplifying transistor, a 1st controlled current source, and a 2nd controlled current source. The 1st amplifying transistor is coupled in series with the 1st controlled current source and the 2nd amplifying transistor is coupled in series with the 2nd controlled current source. The 1st and 2nd amplifying transistors are operably coupled to receive a differential input signal and provide a gained and level shifted representation of the differential input signal based on the controlled currents provided by the 1st and 2nd current sources. The amount of gain is based on the transconductance properties of the 1st and 2nd amplifying transistors and of the 1st and 2nd current sources.Type: GrantFiled: March 30, 2001Date of Patent: April 23, 2002Assignee: Xilinx, Inc.Inventor: Shahriar Rokhsaz
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Patent number: 6175601Abstract: A pre-amplifier circuit, which may be used in a variety of data recovery circuits to accurately recover data transmissions, includes an input regulatory circuit, a feedback circuit, and an amplifier. The input regulatory circuit regulates the magnitude of the data signal provided to the amplifier based on feedback signals from a feedback circuit. For low level data signals, the input regulatory circuit provides a full, or almost full, representation of the data signal to the amplifier for amplification. But, when the data signal levels increase, the input regulatory circuit attenuates, based on the feedback signals, the data signals more and more before providing them to the amplifier, such that the output of the amplifier stays within a certain range.Type: GrantFiled: November 23, 1998Date of Patent: January 16, 2001Assignee: SigmaTel, Inc.Inventors: Mathew A Rybicki, H. Spence Jackson, Shahriar Rokhsaz
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Patent number: 6163580Abstract: A method and apparatus for detecting data is accomplished by an enhanced adaptive threshold which is coupled to receive a data signal and a first reference value. The enhanced adaptive threshold, based on the inputs, provides a threshold to a mixing circuit which, in turn, mixes the threshold with the data signal. The output of the mixer is then subsequently compared with a reference signal to provide an indication of the data signal and preserving its pulse width. The threshold produced by the adaptive threshold circuit is a fixed value when the relationship between the data signal and the first value is in the first state (i.e., the data signal is less than the first value) and the threshold is a proportional threshold when the data signal and the first value are in a second relationship (i.e., the data signal is greater than the first value).Type: GrantFiled: June 9, 1997Date of Patent: December 19, 2000Assignee: Sigmatel, Inc.Inventors: H. Spence Jackson, Mathew A. Rybicki, Shahriar Rokhsaz
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Patent number: 6144473Abstract: A method and apparatus for transceiving data over a wireless communication path with minimal effects from cross-talk is accomplished by a receiving circuit, a transmission circuit, and an interference cancellation circuit. The receiving circuit includes an amplifier and a scaling circuit which operate upon input data signals to produce a scaled representation thereof having high pulse with fidelity. The amplifier circuit and scaling circuit each include adjustable circuitry which are configured based on the magnitude of the received data signals. The interference cancellation circuit provides a signal to the amplifier circuit and scaling circuit to bias the respective adjustable circuitry to an initial operating level when the transmission circuit is transmitting data and/or upon completion of such transmissions.Type: GrantFiled: June 9, 1997Date of Patent: November 7, 2000Assignee: Sigmatel, Inc.Inventors: Shahriar Rokhsaz, Mathew A. Rybicki, H. Spence Jackson
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Patent number: 6128354Abstract: A pre-amplifier circuit, which may be used in a variety of data recovery circuits to accurately recover data transmissions, includes an input regulatory circuit, a feedback circuit, and an amplifier. The input regulatory circuit regulates the magnitude of the data signal provided to the amplifier based on feedback signals from a feedback circuit. For low level data signals, the input regulatory circuit provides a fill, or almost full, representation of the data signal to the amplifier for amplification. But, when the data signal levels increase, the input regulatory circuit attenuates, based on the feedback signals, the data signals more and more before providing them to the amplifier, such that the output of the amplifier stays within a certain range.Type: GrantFiled: November 23, 1998Date of Patent: October 3, 2000Assignee: Sigmatel, Inc.Inventors: Mathew A Rybicki, H. Spence Jackson, Shahriar Rokhsaz