Patents by Inventor Xiaoqian Zhang

Xiaoqian Zhang 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).

  • Publication number: 20160133305
    Abstract: In an example, a control device includes a data path, a clock path, a multiplexing circuit, and a calibration unit. The data path comprises a data delay unit coupled to a data input of a sampling circuit. The clock path comprises a clock delay unit coupled to a clock input of the sampling circuit. The multiplexing circuit selectively couples a reference clock or a data bus to an input of the data delay unit, and selectively couples the reference clock or a source clock to an input of the clock delay unit. The calibration unit is coupled to a data output of the sampling circuit. The calibration unit is operable to adjust delay values of the data delay unit and the clock delay unit based on the data output of the sampling circuit to establish and maintain a relative delay between the data path and the clock path.
    Type: Application
    Filed: November 6, 2014
    Publication date: May 12, 2016
    Applicant: XILINX, INC.
    Inventors: Terence J. Magee, Xiaoqian Zhang
  • Patent number: 9331701
    Abstract: A data interface enabling the calibration of input data comprises a first data receiver having a first plurality of input data lines coupled to receive a corresponding first plurality of data bits associated with a data bus, the first data receiver having a first control circuit enabling calibration of the first plurality of input data lines; and a second data receiver having a second plurality of input data lines coupled to receive a corresponding second plurality of data bits associated with the data bus, the second data receiver having a second control circuit enabling calibration of the second plurality of data lines. The first plurality of input data lines of the first data receiver are calibrated in parallel with the second plurality of input data lines of the second data receiver.
    Type: Grant
    Filed: June 11, 2014
    Date of Patent: May 3, 2016
    Assignee: XILINX, INC.
    Inventors: Xiaoqian Zhang, Terence Magee
  • Patent number: 8861669
    Abstract: The present disclosure provides techniques for recovering source stream clock data at the sink in a high definition multimedia digital content transport system. The disclosure includes a fractional-N Phase-Locked Loop (PLL) based clock generator, a programmable Sigma-Delta Modulator (SDM), and a clock data calibrator to fully recover the original source stream clock data. The fractional-N PLL provides flexible source stream clock recovery. When there is a frequency deviation between the original clock and the regenerated clock, the clock data calibrator control circuit adjusts the clock data, preventing any stream data buffer overflow or underflow problems. The disclosed techniques are compatible with the sink devices based on the standards of DisplayPort and HDMI.
    Type: Grant
    Filed: September 30, 2009
    Date of Patent: October 14, 2014
    Assignee: Synaptics Incorporated
    Inventors: Xiaoqian Zhang, Shubing Zhai, Yanbo Wang
  • Patent number: 8531352
    Abstract: A multi-monitor display driver that provides consolidated EDID data is provided. The display driver reads the EDID data from the one or more monitors coupled to the driver, determines a consolidated EDID data that is compatible with each of the monitors, and writes the EDID data to an EDID memory in the driver. A source interacting with the driver reads the consolidated EDID data to control interactions with the driver.
    Type: Grant
    Filed: June 15, 2010
    Date of Patent: September 10, 2013
    Assignee: Synaptics Incorporated
    Inventors: Henry Zeng, Jing Qian, Xiaoqian Zhang, Xuexin Liu
  • Patent number: 8422518
    Abstract: A method of transmitting audio data across a digital interface is provided. The method includes receiving audio data, organized as a plurality of audio samples. At least one of the plurality of audio samples may be placed into a data packet. The data packet may be transmitted during a valid transmission interval if the data packet is full or during a valid transmission interval in response to receiving a packet send event.
    Type: Grant
    Filed: August 19, 2008
    Date of Patent: April 16, 2013
    Assignee: Integrated Device Technology, inc.
    Inventors: Zhiyong Guan, Xiaoqian Zhang, Qi Li
  • Patent number: 8217689
    Abstract: A method and a circuit are described for recovery of video clocks for a DisplayPort receiver. The disclosure includes two clock dividers, a direct digital synthesis (DDS), a fixed multiplier Phase-Locked Loop (PLL) on a DisplayPort video system. A DisplayPort receiver link clock is divided to a lower frequency as the input of the DDS which can lower the performance requirement on a DDS circuit. The output from a time stamp value indirectly controls a direct digital synthesis device, which then drives a PLL to generate the recovery clock signal. The technique is suitable for implementation on an integrated circuit and Field Programmable Gate array system.
    Type: Grant
    Filed: January 19, 2010
    Date of Patent: July 10, 2012
    Assignee: Integrated Device Technology, Inc.
    Inventors: Lu Yang, Sibing Wang, Xiaoqian Zhang
  • Patent number: 8095707
    Abstract: A method and apparatus for synchronizing I/O peripherals with a CPU in an embedded system is discussed. The method involves receiving an address from the CPU in response to a read and/or write access, translating the address received from the CPU to identify a I/O peripheral to be accessed, disabling the operation of the CPU and synchronizing a memory from the CPU clock domain to the clock domain of the identified I/O peripheral. Upon completion of the read/write access, the identified I/O peripheral sends an acknowledgment, the memory is then synchronized from the clock domain of the I/O peripheral to the CPU clock domain and the operation of the CPU is then enabled. In another embodiment, if the acknowledgement from the identified I/O peripheral is not received within a predefined time duration, reserved data is sent to the CPU and the operation/access can be restarted.
    Type: Grant
    Filed: August 19, 2008
    Date of Patent: January 10, 2012
    Assignee: Integrated Device Technology, inc.
    Inventors: Xiaoqian Zhang, Zhiyong Guan, Qi Li
  • Publication number: 20110310070
    Abstract: A multi-monitor display driver that splits a received video image into multiple images for display on separate monitors. The driver includes a line buffer where data from a received image is written. Monitor interfaces can receive data from a portion of the line buffer corresponding to the interface to split the image.
    Type: Application
    Filed: June 14, 2011
    Publication date: December 22, 2011
    Inventors: Henry ZENG, Jing QIAN, Xiaoqian ZHANG, Xuexin LIU
  • Publication number: 20110304522
    Abstract: A multi-monitor display driver that provides consolidated EDID data is provided. The display driver reads the EDID data from the one or more monitors coupled to the driver, determines a consolidated EDID data that is compatible with each of the monitors, and writes the EDID data to an EDID memory in the driver. A source interacting with the driver reads the consolidated EDID data to control interactions with the driver.
    Type: Application
    Filed: June 15, 2010
    Publication date: December 15, 2011
    Inventors: HENRY ZENG, JING QIAN, XIAOQIAN ZHANG, Xuexin LIU
  • Publication number: 20110267116
    Abstract: A method and a circuit are described for recovery of video clocks for a DisplayPort receiver. The disclosure includes two clock dividers, a direct digital synthesis (DDS), a fixed multiplier Phase-Locked Loop (PLL) on a DisplayPort video system. A DisplayPort receiver link clock is divided to a lower frequency as the input of the DDS which can lower the performance requirement on a DDS circuit. The output from a time stamp value indirectly controls a direct digital synthesis device, which then drives a PLL to generate the recovery clock signal. The technique is suitable for implementation on an integrated circuit and Field Programmable Gate array system.
    Type: Application
    Filed: January 19, 2010
    Publication date: November 3, 2011
    Inventors: Lu Yang, Sibing Wang, Xiaoqian Zhang
  • Patent number: 8023594
    Abstract: A biphase mark signal receiver includes a data and clock recovery circuit. The data recovery circuit may include a coarse recovery stage and a fine recovery stage. The coarse recovery stage is configured to detect repeating occurrences of a first preamble (e.g., Y-preamble) within a biphase encoded data stream received by the data recovery circuit. The fine recovery stage is configured to generate a recovered data stream, in response to estimating a plurality of timing decision points (e.g., 3UI, 2UI and 1UI) from the repeating occurrences of the first preamble detected by the coarse recovery stage.
    Type: Grant
    Filed: July 11, 2008
    Date of Patent: September 20, 2011
    Assignee: Integrated Device Technology, inc.
    Inventors: Qi Li, Xiaoqian Zhang, Zhiyong Guan
  • Patent number: 7940662
    Abstract: Data received from a bursty interface is received on a burst-by-burst basis. Once a burst is received, it is stored in a processing queue. A complete burst is received so long a processing queue can accommodate a data burst. The complete data burst is directed to an output and used to create a complete data burst on said output. The output burst is dispatched so long as a receiving port is able to accept the output burst.
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: May 10, 2011
    Assignee: Integrated Device Technology, Inc.
    Inventors: Shubing Zhai, Yefei Sun, Xiaoqian Zhang, Zhonghai Gan
  • Publication number: 20110075782
    Abstract: The present disclosure provides techniques for recovering source stream clock data at the sink in a high definition multimedia digital content transport system. The disclosure includes a fractional-N Phase-Locked Loop (PLL) based clock generator, a programmable Sigma-Delta Modulator (SDM), and a clock data calibrator to fully recover the original source stream clock data. The fractional-N PLL provides flexible source stream clock recovery. When there is a frequency deviation between the original clock and the regenerated clock, the clock data calibrator control circuit adjusts the clock data, preventing any stream data buffer overflow or underflow problems. The disclosed techniques are compatible with the sink devices based on the standards of DisplayPort and HDMI.
    Type: Application
    Filed: September 30, 2009
    Publication date: March 31, 2011
    Inventors: Xiaoqian Zhang, Shubing Zhai, Yanbo Wang
  • Patent number: 7750696
    Abstract: A method of calibrating a PLL that includes forcing a control voltage input to a voltage controlled oscillator to be a reference voltage and setting a calibration divider coupled to receive an output clock signal from the voltage controlled oscillator such that the calibration divider utilizes one of a plurality of divisors that results in the output clock signal having a high frequency can substantially avoid overshoot and glitch problems associated with conventional PLL calibrations.
    Type: Grant
    Filed: March 20, 2008
    Date of Patent: July 6, 2010
    Assignee: Integrated Device Technology, Inc.
    Inventors: Yanbo Wang, Xiaoqian Zhang, Shubing Zhai
  • Publication number: 20100046557
    Abstract: A method of transmitting audio data across a digital interface is provided. The method includes receiving audio data, organized as a plurality of audio samples. At least one of the plurality of audio samples may be placed into a data packet. The data packet may be transmitted during a valid transmission interval if the data packet is full or during a valid transmission interval in response to receiving a packet send event.
    Type: Application
    Filed: August 19, 2008
    Publication date: February 25, 2010
    Inventors: ZHIYONG GUAN, Xiaoqian Zhang, Qi Li
  • Publication number: 20100049888
    Abstract: A method and apparatus for synchronizing I/O peripherals with a CPU in an embedded system is discussed. The method involves receiving an address from the CPU in response to a read and/or write access, translating the address received from the CPU to identify a I/O peripheral to be accessed, disabling the operation of the CPU and synchronizing a memory from the CPU clock domain to the clock domain of the identified I/O peripheral. Upon completion of the read/write access, the identified I/O peripheral sends an acknowledgment, the memory is then synchronized from the clock domain of the I/O peripheral to the CPU clock domain and the operation of the CPU is then enabled. In another embodiment, if the acknowledgement from the identified I/O peripheral is not received within a predefined time duration, reserved data is sent to the CPU and the operation/access can be restarted.
    Type: Application
    Filed: August 19, 2008
    Publication date: February 25, 2010
    Inventors: XIAOQIAN ZHANG, Zhiyong Guan, Qi Li
  • Publication number: 20090237132
    Abstract: A method of calibrating a PLL that includes forcing a control voltage input to a voltage controlled oscillator to be a reference voltage and setting a calibration divider coupled to receive an output clock signal from the voltage controlled oscillator such that the calibration divider utilizes one of a plurality of divisors that results in the output clock signal having a high frequency can substantially avoid overshoot and glitch problems associated with conventional PLL calibrations.
    Type: Application
    Filed: March 20, 2008
    Publication date: September 24, 2009
    Inventors: Yanbo Wang, Xiaoqian Zhang, Shubing Zhai
  • Patent number: 7573896
    Abstract: A method and apparatus for generic interface, packet cut-through, overbooking, queue concatenation, and logical identification priority for a System Packet Interface device have been disclosed.
    Type: Grant
    Filed: October 14, 2005
    Date of Patent: August 11, 2009
    Assignee: Integrated Device Technology, Inc.
    Inventors: Sibing Wang, Xiaoqian Zhang, Zhonghai Gan, Shubing Zhai
  • Patent number: 7571337
    Abstract: A data output circuit includes a plurality of clocked data output buffers, each of which drives a data output thereof responsive to a clock signal and an adjustable multiphase clock signal generator that generates a plurality of clock signals of different phases and that is operative to shift the plurality of clock signals relative to a reference clock signal responsive to a first control signal. The data output circuit further includes a clock signal selector that selectively applies the plurality of clock signals to the data output buffers responsive to a second control signal. The adjustable multiphase clock signal generator may include, for example, a control loop, such as a phase locked loop or a delay locked loop, which selectively feeds back one of the plurality of clock signals responsive to the first control signal.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: August 4, 2009
    Assignee: Integrated Device Technology, Inc.
    Inventors: Shubing Zhai, Xiaoqian Zhang
  • Publication number: 20060083185
    Abstract: A method and apparatus for generic interface, packet cut-through, overbooking, queue concatenation, and logical identification priority for a System Packet Interface device have been disclosed.
    Type: Application
    Filed: October 14, 2005
    Publication date: April 20, 2006
    Applicant: Integrated Device Technology, Inc.
    Inventors: Sibing Wang, Xiaoqian Zhang, Zhonghai Gan, Shubing Zhai