Patents by Inventor Sivakumar Doraiswamy

Sivakumar Doraiswamy 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: 20140254294
    Abstract: An integrated circuit (IC) memory controller is disclosed. The memory controller includes a receiver to receive a strobe signal and provide an internal strobe signal. An adjustable delay circuit delays an enable signal to generate a delayed enable signal. A gate circuit generates a gated strobe signal using the delayed enable signal that masks transitions of the internal strobe signal that occur prior to a valid region of the internal strobe signal. A sample circuit samples data using the gated strobe signal.
    Type: Application
    Filed: May 21, 2014
    Publication date: September 11, 2014
    Applicant: Rambus Inc.
    Inventors: Jade M. Kizer, Sivakumar Doraiswamy, Benedict Lau
  • Patent number: 8743635
    Abstract: A memory controller for strobe-based memory systems is disclosed. The memory controller includes a circuit to generate a control signal having a predetermined timing relationship with respect to a first clock signal, a circuit to receive the control signal, and a receiver to sample the read data in response to the qualified read strobe signal. The receiving circuit includes an input to receive an external read strobe signal transmitted by a semiconductor memory device, circuitry to synchronize the control signal and the received read strobe signal to have a common timing relationship with respect to each other, and circuitry to gate the read strobe signal based on the synchronized control signal.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: June 3, 2014
    Assignee: Rambus Inc.
    Inventors: Jade M. Kizer, Sivakumar Doraiswamy, Benedict Lau
  • Patent number: 8237468
    Abstract: Described are amplifiers that facilitate high-speed communication with calibrated drive strength and termination impedance. Drivers and termination elements can be divided into a number N of parallel portions, one or more of which can be disabled and updated without interfering with signal (e.g., clock or data) transmission. Some embodiments identify inactive elements by examining incoming signals.
    Type: Grant
    Filed: August 3, 2010
    Date of Patent: August 7, 2012
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Vijay Gadde, Sivakumar Doraiswamy
  • Publication number: 20120170389
    Abstract: A memory controller for strobe-based memory systems is disclosed. The memory controller comprises a circuit to generate a control signal having a predetermined timing relationship with respect to a first clock signal, a circuit to receive the control signal, and a receiver to sample the read data in response to the qualified read strobe signal. The receiving circuit comprises an input to receive an external read strobe signal transmitted by a semiconductor memory device, circuitry to synchronize the control signal and the received read strobe signal to have a common timing relationship with respect to each other, and circuitry to gate the read strobe signal based on the synchronized control signal.
    Type: Application
    Filed: March 9, 2012
    Publication date: July 5, 2012
    Inventors: Jade M. Kizer, Sivakumar Doraiswamy, Benedict Lau
  • Patent number: 8151133
    Abstract: A method of calibrating read operations in a memory system is disclosed. The method involves placing a memory controller in a calibration mode, and performing a series of dummy read operations. Each of the read operations performs a read of pre-specified data stored in at least one memory component while using different ones of delayed enable signals. Data read from respective dummy read operations is compared to identify successful read operations while the timing information from successful read operations is compared to identify a suitable delayed enable signal.
    Type: Grant
    Filed: June 2, 2009
    Date of Patent: April 3, 2012
    Assignee: Rambus Inc.
    Inventors: Jade M. Kizer, Sivakumar Doraiswamy, Benedict Lau
  • Publication number: 20090240968
    Abstract: A method of calibrating read operations in a memory system is disclosed. The method involves placing a memory controller in a calibration mode, and performing a series of dummy read operations. Each of the read operations performs a read of pre-specified data stored in at least one memory component while using different ones of delayed enable signals. Data read from respective dummy read operations is compared to identify successful read operations while the timing information from successful read operations is compared to identify a suitable delayed enable signal.
    Type: Application
    Filed: June 2, 2009
    Publication date: September 24, 2009
    Inventors: Jade M. Kizer, Sivakumar Doraiswamy, Benedict Lau
  • Patent number: 7543172
    Abstract: Systems and methods for masking strobe signals in strobe-based systems are provided below. These strobe-masking systems receive a strobe signal from a component operating under one clock domain and in turn generate a masked version of the strobe signal. Components of a host system use the masked strobe signal to receive or transfer data from the clock domain of the strobe signal through a mesochronous clock domain crossing into a different clock domain.
    Type: Grant
    Filed: December 21, 2004
    Date of Patent: June 2, 2009
    Assignee: Rambus Inc.
    Inventors: Jade M. Kizer, Sivakumar Doraiswamy, Benedict Lau
  • Patent number: 7389194
    Abstract: Described are amplifiers that facilitate high-speed communication with calibrated drive strength and tennination impedance. Drivers and termination elements can be divided into a number N of parallel portions, one or more of which can be updated while signals (e.g, clock or data) are transmitted. Some embodiments identify elements in a high-impedance state by examining incoming signals.
    Type: Grant
    Filed: July 6, 2005
    Date of Patent: June 17, 2008
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Vijay Gadde, Sivakumar Doraiswamy
  • Publication number: 20060136769
    Abstract: Systems and methods for masking strobe signals in strobe-based systems are provided below. These strobe-masking systems receive a strobe signal from a component operating under one clock domain and in turn generate a masked version of the strobe signal. Components of a host system use the masked strobe signal to receive or transfer data from the clock domain of the strobe signal through a mesochronous clock domain crossing into a different clock domain.
    Type: Application
    Filed: December 21, 2004
    Publication date: June 22, 2006
    Inventors: Jade Kizer, Sivakumar Doraiswamy, Benedict Lau
  • Patent number: 7028069
    Abstract: The invention provides a dynamic domino circuit that is robust under noisy condition. The invention also provides a dynamic adder that contains nodes that can produce true dynamic inversion without compromising area or speed. The invention further improves speed of the adders by cutting the latch delay while not requiring complex clocking.
    Type: Grant
    Filed: November 27, 2001
    Date of Patent: April 11, 2006
    Assignee: Raza Microelectronics Inc.
    Inventors: Edward T. Pak, Sivakumar Doraiswamy