Patents by Inventor Stefanos Sidiropoulos

Stefanos Sidiropoulos 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: 6950956
    Abstract: An integrated circuit device includes a receiver, a register and a clock circuit. The receiver samples data from an external signal line in response to an internal clock signal. The register stores a value that represents a timing offset to adjust the time at which the data is sampled. The clock circuit generates the internal clock signal such that the internal clock signal maintains a controlled timing relationship with respect to an external clock signal. The clock circuit includes an interpolator that phase mixes a set of reference clock signals such that the internal clock signal is phase offset in accordance with the value.
    Type: Grant
    Filed: November 3, 2003
    Date of Patent: September 27, 2005
    Assignee: Rambus Inc.
    Inventors: Jared LeVan Zerbe, Kevin S. Donnelly, Stefanos Sidiropoulos, Donald C. Stark, Mark A. Horowitz, Leung Yu, Roxanne Vu, Jun Kim, Bruno W. Garlepp, Tsyr-Chyang Ho, Benedict Chung-Kwong Lau
  • Publication number: 20050207255
    Abstract: A system comprises a controller device, an integrated circuit buffer device and a first and second memory device. A first plurality of signal lines is coupled to the controller device. A second plurality of signal lines is coupled to the first memory device and the integrated circuit buffer device. The second plurality of signal lines carries first address information from the integrated circuit buffer device to the first memory device. A third plurality of signal lines is coupled to the first memory device and the integrated circuit buffer device. The third plurality of signal lines carries first control information from the integrated circuit buffer device to the first memory device. A first signal line is coupled to the first memory device and the integrated circuit buffer device. The first signal line carries a first signal from the integrated circuit buffer device to the first memory device.
    Type: Application
    Filed: May 25, 2005
    Publication date: September 22, 2005
    Inventors: Richard Perego, Stefanos Sidiropoulos, Ely Tsern
  • Publication number: 20050210196
    Abstract: A memory module includes an integrated circuit buffer device that receives control information via a connector interface. A first plurality of signal lines carries a first address from the integrated circuit buffer device to a first memory device. A second plurality of signal lines carries a first control signal from the integrated circuit buffer device to the first memory device. The first control signal specifies a read operation by the first memory device such that the first memory device provides first data, accessed from a memory location in the first memory device based on the first address, to the integrated circuit buffer device. A first signal line carries a first signal from the integrated circuit buffer device to the first memory device. The first signal synchronizes communication of the first control signal from the integrated circuit buffer device to the first memory device. A third plurality of signal lines carries a second address from the integrated circuit device to the second memory device.
    Type: Application
    Filed: May 13, 2005
    Publication date: September 22, 2005
    Inventors: Richard perego, Stefanos Sidiropoulos, Ely Tsern
  • Publication number: 20050193163
    Abstract: An integrated circuit buffer device comprises a first receiver circuit to receive control information and address information from a controller device. A first interface includes a first interface portion to provide a first address to a first memory device. A second interface portion provides a first control signal to the first memory device. The first control signal specifies a read operation such that the first memory device provides a first data, accessed from a memory location based on the first address, to the integrated circuit buffer device in response to the first control signal specifying the read operation. A third interface portion provides a first clock signal to the first memory device. The first clock signal synchronizes communication of the first control signal from the integrated circuit buffer device to the first memory device. A fourth interface portion receives the first data. A second interface includes a first interface portion to provide a second address to a second memory device.
    Type: Application
    Filed: April 29, 2005
    Publication date: September 1, 2005
    Inventors: Richard Perego, Stefanos Sidiropoulos, Ely Tsern
  • Patent number: 6928128
    Abstract: Clock alignment circuits and techniques for reducing power dissipation, increasing power supply noise immunity, decreasing process and temperature variation sensitivity, and providing a wide operating range. A power supply generator generates an isolated supply voltage for a delay line used in a clock alignment circuit. The delay line generates a delayed clock from a reference clock. A comparator detects a correction information (i.e., delay or phase error) between the delayed clock and the reference clock and generates error information representative of the correction information. A charge pump circuit converts the error information into a voltage signal, wherein the voltage signal is a scaled representation of the error information.
    Type: Grant
    Filed: May 3, 1999
    Date of Patent: August 9, 2005
    Assignee: Rambus Inc.
    Inventor: Stefanos Sidiropoulos
  • Publication number: 20050156934
    Abstract: A computer system includes a controller device having an interface disposed on a circuit board. A first socket is disposed on the circuit board and receives a first memory module having a first integrated circuit buffer device. The first memory module has a first plurality of integrated circuit memory devices coupled to the first integrated circuit buffer device. A first point-to-point link is coupled to the interface of the controller device. When the first memory module is received by the first socket, the first integrated circuit buffer device receives control information, address information, and data from the controller device over the first point-to-point link. A second socket is disposed on the circuit board and receives a second memory module having a second integrated circuit buffer device. The second memory module has a second plurality of memory devices coupled to the second integrated circuit buffer device.
    Type: Application
    Filed: March 11, 2005
    Publication date: July 21, 2005
    Inventors: Richard Perego, Stefanos Sidiropoulos, Ely Tsern
  • Publication number: 20050149662
    Abstract: A system comprises a master device and a first integrated circuit buffer device. A first plurality of integrated circuit memory devices are coupled to the first integrated circuit buffer device. A first plurality of signal lines are coupled to the first integrated circuit buffer device and the master device, wherein the first plurality of signal lines communicate control information, address information and data from the master device to the first integrated circuit buffer device. A second plurality of signal lines are coupled to the first integrated circuit buffer device. A second integrated circuit buffer device is coupled to the second plurality of signal lines, the second integrated circuit buffer device receives the control information, the address information and the data from the first integrated circuit buffer device over the second plurality of signal lines. A second plurality of integrated circuit memory devices are coupled to the second integrated circuit buffer device.
    Type: Application
    Filed: February 10, 2005
    Publication date: July 7, 2005
    Inventors: Richard Perego, Stefanos Sidiropoulos, Ely Tsern
  • Publication number: 20050132158
    Abstract: A memory system includes a memory controller and a memory component coupled to each other. The memory controller includes an interface to receive a first signal and a second signal from the memory component, wherein the first signal comprises a first symbol and the second signal comprises a second symbol. A first circuit of the memory controller receives the first signal by sampling the first symbol using a first timing offset relative to a reference clock signal, and a second circuit of the memory controller receives the second signal by sampling the second symbol using a second timing offset relative to the reference clock signal. The first timing offset is independent of the second timing offset.
    Type: Application
    Filed: January 18, 2005
    Publication date: June 16, 2005
    Inventors: Craig Hampel, Richard Perego, Stefanos Sidiropoulos, Ely Tsern, Fredrick Ware
  • Publication number: 20050057292
    Abstract: A method of operating a master/slave system includes the step of identifying a master receive data phase value to coordinate the transfer of data from a slave device without phase alignment circuitry to a master device with a universal phase aligner. Data is transferred from the slave device to the master device in accordance with the master receive data phase value. The master device characterizes a master transmit data phase value to coordinate the transfer of data from the master device to the slave device. Subsequently, the master device routes data to the slave device in accordance with the master transmit data phase value.
    Type: Application
    Filed: October 11, 2004
    Publication date: March 17, 2005
    Inventor: Stefanos Sidiropoulos
  • Publication number: 20050041504
    Abstract: A memory system architecture/interconnect topology that includes at least one point-to-point link between a master, and at least one memory subsystem. The memory subsystem includes a buffer device coupled to a plurality of memory devices. The memory system may be upgraded through dedicated point-to-point links and corresponding memory subsystems.
    Type: Application
    Filed: September 28, 2004
    Publication date: February 24, 2005
    Inventors: Richard Perego, Stefanos Sidiropoulos, Ely Tsern
  • Publication number: 20050044303
    Abstract: A memory system architecture/interconnect topology that includes at least one point-to-point link between a master, and at least one memory subsystem. The memory subsystem includes a buffer device coupled to a plurality of memory devices. The memory system may be upgraded through dedicated point-to-point links and corresponding memory subsystems.
    Type: Application
    Filed: September 28, 2004
    Publication date: February 24, 2005
    Inventors: Richard Perego, Stefanos Sidiropoulos, Ely Tsern
  • Publication number: 20050005179
    Abstract: A current controller for a multi-level current mode driver. The current controller includes a multi-level voltage reference and at least one source calibration signal. A comparator is coupled by a coupling network to the multi-level voltage reference and the at least one source calibration signal. A selected voltage is applied from the multi-level voltage reference and a selected source calibration signal is applied from the at least one source calibration signal to the comparator.
    Type: Application
    Filed: July 30, 2004
    Publication date: January 6, 2005
    Applicant: Rambus, Inc.
    Inventors: Carl Werner, Mark Horowitz, Pak Chau, Scott Best, Stefanos Sidiropoulos
  • Patent number: 6839393
    Abstract: A method of operating a master/slave system includes the step of identifying a master receive data phase value to coordinate the transfer of data from a slave device without phase alignment circuitry to a master device with a universal phase aligner. Data is transferred from the slave device to the master device in accordance with the master receive data phase value. The master device characterizes a master transmit data phase value to coordinate the transfer of data from the master device to the slave device. Subsequently, the master device routes data to the slave device in accordance with the master transmit data phase value.
    Type: Grant
    Filed: July 14, 1999
    Date of Patent: January 4, 2005
    Assignee: Rambus Inc.
    Inventor: Stefanos Sidiropoulos
  • Patent number: 6832284
    Abstract: A memory system architecture/interconnect topology that includes at least one point-to-point link between a master, and at least one memory subsystem. The memory subsystem includes a buffer device coupled to a plurality of memory devices. The memory system may be upgraded through dedicated point-to-point links and corresponding memory subsystems. The master communicates to the plurality of memory devices in each memory subsystem through the respective buffer device via each point-to-point link.
    Type: Grant
    Filed: July 23, 2003
    Date of Patent: December 14, 2004
    Assignee: Rambus Inc.
    Inventors: Richard E. Perego, Stefanos Sidiropoulos, Ely Tsern
  • Patent number: 6809600
    Abstract: Dual loop phase lock loops having a high loop bandwidth with low power consumption are described. Each loop is provided with a voltage supply regulator circuit which regulates the voltage of a portion of each loop. In one embodiment, the outer loop employs a regulation circuit comprising a two stage operational amplifier which is compensated by a compensation circuit that is configured to ensure that the dominant pole of the operational amplifier is associated with the first stage of the operational amplifier.
    Type: Grant
    Filed: January 3, 2003
    Date of Patent: October 26, 2004
    Assignee: Rambus Inc.
    Inventors: Kun-Yung Ken Chang, Yingxuan Li, Stefanos Sidiropoulos
  • Publication number: 20040174195
    Abstract: A delay-locked loop circuit generates a first clock signal. The delay-locked loop circuit includes a first delay element coupled in a feedback path of the delay-locked loop circuit to advance the first clock signal relative to a reference clock signal by a first time period. A second delay element is coupled to receive the first clock signal from the delay-locked loop circuit. The second delay element also outputs a second clock signal that is delayed relative to the first clock signal by the first time period. The delay-locked loop circuit may include a phase detector to identify phase differences between the first clock signal and the reference clock signal. A third delay element may be coupled between the delay-locked loop circuit and the second delay element.
    Type: Application
    Filed: March 22, 2004
    Publication date: September 9, 2004
    Inventors: Benedict C. Lau, Stefanos Sidiropoulos
  • Publication number: 20040168036
    Abstract: A method and apparatus for adjusting the performance of a memory system is provided. A memory control device comprises a master device including a frequency detector, a memory channel, and a memory device coupled to the master device via the memory channel. The memory device includes a decoder designed to receive a control signal from the master device. A clock recovery and alignment circuit receives the control signal from the decoder and adjusts the operating frequency of the memory device in response to the control signal.
    Type: Application
    Filed: March 10, 2003
    Publication date: August 26, 2004
    Inventors: Bruno Werner Garlepp, Pak Shing Chau, Kevin S. Donnelly, Clemenz Portmann, Donald C. Stark, Stefanos Sidiropoulos, Richard M. Barth, Paul G. Davis, Ely K. Tsern
  • Patent number: 6772351
    Abstract: A current controller for a multi-level current mode driver. The current controller includes a multi-level voltage reference and at least one source calibration signal. A comparator is coupled by a coupling network to the multi-level voltage reference and the at least one source calibration signal. A selected voltage is applied from the multi-level voltage reference and a selected source calibration signal is applied from the at least one source calibration signal to the comparator.
    Type: Grant
    Filed: September 5, 2000
    Date of Patent: August 3, 2004
    Assignee: Rambus, Inc.
    Inventors: Carl Werner, Mark Horowitz, Pak Chau, Scott Best, Stefanos Sidiropoulos
  • Publication number: 20040098634
    Abstract: An integrated circuit device includes a receiver, a register and a clock circuit. The receiver samples data from an external signal line in response to an internal clock signal. The register stores a value that represents a timing offset to adjust the time at which the data is sampled. The clock circuit generates the internal clock signal such that the internal clock signal maintains a controlled timing relationship with respect to an external clock signal. The clock circuit includes an interpolator that phase mixes a set of reference clock signals such that the internal clock signal is phase offset in accordance with the value.
    Type: Application
    Filed: November 3, 2003
    Publication date: May 20, 2004
    Inventors: Jared LeVan Zerbe, Kevin S. Donnelly, Stefanos Sidiropoulos, Donald C. Stark, Mark A. Horowitz, Leung Yu, Roxanne Vu, Jun Kim, Bruno W. Garlepp, Tsyr-Chyang Ho, Benedict Chung-Kwong Lau
  • Patent number: 6731148
    Abstract: A delay-locked loop circuit generates a first clock signal. The delay-locked loop circuit includes a first delay element coupled in a feedback path of the delay-locked loop circuit to advance the first clock signal relative to a reference clock signal by a first time period. A second delay element is coupled to receive the first clock signal from the delay-locked loop circuit. The second delay element also outputs a second clock signal that is delayed relative to the first clock signal by the first time period. The delay-locked loop circuit may include a phase detector to identify phase differences between the first clock signal and the reference clock signal. A third delay element may be coupled between the delay-locked loop circuit and the second delay element.
    Type: Grant
    Filed: May 29, 2002
    Date of Patent: May 4, 2004
    Assignee: Rambus, Inc.
    Inventors: Benedict C. Lau, Stefanos Sidiropoulos