Patents by Inventor Michael Tak-Kei Ching

Michael Tak-Kei Ching 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: 7352234
    Abstract: An output driver circuit and current control technique to facilitate high-speed buses with low noise is used to interface with high-speed dynamic RAMs (DRAMs). The architecture includes the following components: an input isolation block (120), an analog voltage divider (104), an input comparator (125), a sampling latch (130), a current control counter (115), and a bitwise output driver (output driver A 107 and output driver B 111).
    Type: Grant
    Filed: January 22, 2007
    Date of Patent: April 1, 2008
    Assignee: Rambus Inc.
    Inventors: Billy Wayne Garrett, Jr., Nancy David Dillon, legal representative, Michael Tak-Kei Ching, William F. Stonecypher, Andy Peng-Pui Chan, Matthew M. Griffin, John B. Dillon
  • Patent number: 7288973
    Abstract: A method and circuit for achieving minimum latency data transfer between two mesochronous (same frequency, different phase) clock domains is disclosed. This circuit supports arbitrary phase relationships between two clock domains and is tolerant of temperature and voltage shifts after initialization while maintaining the same output data latency. In one embodiment, this circuit is used on a bus-system to re-time data from receive-domain, clocks to transmit-domain clocks. In such a system the phase relationships between these two clocks is set by the device bus location and thus is not precisely known. By supporting arbitrary phase resynchronization, this disclosure allows for theoretically infinite bus-length and thus no limitation on device count, as well as arbitrary placement of devices along the bus. This ultimately allows support of multiple latency-domains for very long buses.
    Type: Grant
    Filed: September 27, 2005
    Date of Patent: October 30, 2007
    Assignee: Rambus Inc.
    Inventors: Jared LeVan Zerbe, Michael Tak-kei Ching, Abhijit M. Abhyankar, Richard M. Barth, Andy Peng-Pui Chan, Paul G. Davis, William F. Stonecypher
  • Patent number: 7167039
    Abstract: A method of operating an integrated circuit including an output driver. The method includes storing a value in a register, wherein the value is representative of a voltage swing setting of an output driver. The voltage swing setting of the output driver is adjusted using a counter that holds a count value representing an update to the voltage swing setting. The count value is updated in accordance with a signal that indicates an adjustment to the voltage swing setting. In addition, an integrated circuit memory device comprising an output driver, a register and a counter is provided. The counter updates a count value in response to a signal that indicates a direction to adjust the count value.
    Type: Grant
    Filed: July 14, 2004
    Date of Patent: January 23, 2007
    Assignee: Rambus Inc.
    Inventors: Billy Wayne Garrett, Jr., Nancy David Dillon, legal representative, Michael Tak-Kei Ching, William F. Stonecypher, Andy Peng-Pui Chan, Matthew M. Griffin, John B. Dillon, deceased
  • Patent number: 7091761
    Abstract: An output driver has an output multiplexor and an output current driver. The output multiplexor receives a data signal and outputs a q-node signal. The output current 5 river receives the q-node signal and drives a bus based on the q-node signal. The output multiplexor processes the data signal in various ways to generate the q-node signal. The output current driver is responsive to current control bits to select a amount of output drive current. In addition, the output multiplexor is controlled such that the output impedance of the output current driver is maintained within a predetermined range.
    Type: Grant
    Filed: June 8, 2005
    Date of Patent: August 15, 2006
    Assignee: Rambus, Inc.
    Inventors: Donald C. Stark, Jun Kim, Kurt T. Knorpp, Michael Tak-Kei Ching, Natsuki Kushiyama
  • Patent number: 6975160
    Abstract: A system including an integrated circuit memory device. The integrated circuit device comprises a register to store a value representative of an output voltage setting. A circuit holds a value representative of an adjustment to the output voltage setting. An output driver outputs a drive voltage during a calibration operation, wherein a signal is generated based on a comparison between a signal derived from the drive voltage and a reference voltage. The signal updates the value representative of the adjustment to the output voltage setting.
    Type: Grant
    Filed: December 14, 2004
    Date of Patent: December 13, 2005
    Assignee: Rambus Inc.
    Inventors: Billy Wayne Garrett, Jr., Nancy David Dillon, legal representative, Michael Tak-Kei Ching, William E. Stonecynher, Andy Peng-Pui Chan, Matthew M. Griffin, John B. Dillon, deceased
  • Patent number: 6975159
    Abstract: A method of operating a memory system that includes an integrated circuit memory device is provided. A value representing an output voltage setting of an output driver of the memory device is stored in a register. The output driver outputs the drive voltage. A signal derived from the drive voltage is compared to a reference signal to generate a signal that indicates an adjustment to the output voltage setting. The output voltage setting of the output driver is adjusted using a counter that holds a count value representing an update to the output voltage setting. The count value is updated in accordance with a signal that indicates the adjustment to the output voltage setting.
    Type: Grant
    Filed: November 5, 2004
    Date of Patent: December 13, 2005
    Assignee: Rambus Inc.
    Inventors: Billy Wayne Garrett, Jr., Nancy David Dillon, legal representative, Michael Tak-Kei Ching, William F. Stonecynher, Andy Peng-Pui Chan, Matthew M. Griffin, John B. Dillon, deceased
  • Patent number: 6949958
    Abstract: A method and circuit for achieving minimum latency data transfer between two mesochronous (same frequency, different phase) clock domains is disclosed. This circuit supports arbitrary phase relationships between two clock domains and is tolerant of temperature and voltage shifts after initialization while maintaining the same output data latency. In one embodiment, this circuit is used on a bus-system to re-time data from receive-domain, clocks to transmit-domain clocks. In such a system the phase relationships between these two clocks is set by the device bus location and thus is not precisely known. By supporting arbitrary phase resynchronization, this disclosure allows for theoretically infinite bus-length and thus no limitation on device count, as well as arbitrary placement of devices along the bus. This ultimately allows support of multiple latency-domains for very long buses.
    Type: Grant
    Filed: October 28, 2002
    Date of Patent: September 27, 2005
    Assignee: Rambus Inc.
    Inventors: Jared LeVan Zerbe, Michael Tak-kei Ching, Abhijit M. Abhyankar, Richard M. Barth, Andy Peng-Pui Chan, Paul G. Davis, William F. Stonecypher
  • Patent number: 6922092
    Abstract: An output driver has an output multiplexor and an output current driver. The output multiplexor receives a data signal and outputs a q-node signal. The output current driver receives the q-node signal and drives a bus based on the q-node signal. The output multiplexor processes the data signal in various ways to generate the q-node signal. The output current driver is responsive to current control bits to select a amount of output drive current. In addition, the output multiplexor is controlled such that the output impedance of the output current driver is maintained within a predetermined range.
    Type: Grant
    Filed: December 8, 2003
    Date of Patent: July 26, 2005
    Assignee: Rambus Inc.
    Inventors: Donald C. Stark, Jun Kim, Kurt T. Knorpp, Michael Tak-Kei Ching, Natsuki Kushiyama
  • Patent number: 6870419
    Abstract: An output driver circuit and current control technique to facilitate high-speed buses with low noise is used to interface with high-speed dynamic RAMs (DRAMs). The architecture includes the following components: an input isolation block (120), an analog voltage divider (104), an input comparator (125), a sampling latch (130), a current control counter (115), and a bitwise output driver (output driver A 107 and output driver B 111).
    Type: Grant
    Filed: July 23, 2003
    Date of Patent: March 22, 2005
    Assignee: Rambus Inc.
    Inventors: Billy Wayne Garrett, Jr., Nancy David Dillon, Michael Tak-Kei Ching, William F. Stonecypher, Andy Peng-Pui Chan, Matthew M. Griffin, John B. Dillon
  • Publication number: 20040119511
    Abstract: An output driver has an output multiplexor and an output current driver. The output multiplexor receives a data signal and outputs a q-node signal. The output current driver receives the q-node signal and drives a bus based on the q-node signal. The output multiplexor processes the data signal in various ways to generate the q-node signal. The output current driver is responsive to current control bits to select a amount of output drive current. In addition, the output multiplexor is controlled such that the output impedance of the output current driver is maintained within a predetermined range.
    Type: Application
    Filed: December 8, 2003
    Publication date: June 24, 2004
    Applicant: Rambus Inc.
    Inventors: Donald C. Stark, Jun Kim, Kurt T. Knorpp, Michael Tak-Kei Ching, Natsuki Kushiyama
  • Patent number: 6661268
    Abstract: An output driver has an output multiplexor and an output current driver. The output multiplexor receives a data signal and outputs a q-node signal. The output current driver receives the q-node signal and drives a bus based on the q-node signal. The output multiplexor processes the data signal in various ways to generate the q-node signal. The output current driver is responsive to current control bits to select a amount of output drive current. In addition, the output multiplexor is controlled such that the output impedance of the output current driver is maintained within a predetermined range.
    Type: Grant
    Filed: December 11, 2001
    Date of Patent: December 9, 2003
    Assignee: Rambus Inc.
    Inventors: Donald C. Stark, Jun Kim, Kurt T. Knorpp, Michael Tak-Kei Ching, Natsuki Kushiyama
  • Patent number: 6608507
    Abstract: A memory system and method of adjusting an output driver characteristic of a memory device that is included in the memory system. The method includes providing a command to the memory device that specifies a calibration mode and, during the calibration mode, driving a voltage level onto the first signal line using a first output driver. A first voltage level is derived from an amount of voltage swing generated by the first output driver driving the voltage level onto the first signal line. The method also includes: actively coupling a first comparator to the first signal line; when the first comparator is coupled to the first signal line, comparing the first voltage level with a reference voltage using the first comparator; and adjusting the amount of voltage swing to arrive at a calibrated voltage swing level. In addition, the method includes actively isolation the first comparator from the first signal line upon exiting the calibration mode.
    Type: Grant
    Filed: August 29, 2002
    Date of Patent: August 19, 2003
    Assignee: Rambus Inc.
    Inventors: Billy Wayne Garrett, Jr., John B. Dillon, Michael Tak-Kei Ching, William F. Stonecypher, Andy Peng-Pui Chan, Matthew M. Griffin
  • Patent number: 6556052
    Abstract: A semiconductor controller device to control the operation of a semiconductor memory device. The controller device includes a first output driver coupled to a first output terminal, and a second output driver coupled to a second output terminal. In addition, the controller device includes a voltage divider, coupled between the first and second output terminals, to generate a control voltage based on a voltage level present on the first output terminal and a voltage level present on the second output terminal. In addition, the controller device also includes a comparator, coupled to the voltage divider, to compare the control voltage with a reference voltage, wherein an amount of voltage swing of the first output driver is adjusted based on the comparison between the control voltage and the reference voltage.
    Type: Grant
    Filed: September 12, 2001
    Date of Patent: April 29, 2003
    Inventors: Billy Wayne Garrett, Jr., John B. Dillon, Michael Tak-Kei Ching, William F. Stonecypher, Andy Peng-Pui Chan, Matthew M. Griffin
  • Publication number: 20030053489
    Abstract: A method and circuit for achieving minimum latency data transfer between two mesochronous (same frequency, different phase) clock domains is disclosed. This circuit supports arbitrary phase relationships between two clock domains and is tolerant of temperature and voltage shifts after initialization while maintaining the same output data latency. In one embodiment, this circuit is used on a bus-system to re-time data from receive-domain, clocks to transmit-domain clocks. In such a system the phase relationships between these two clocks is set by the device bus location and thus is not precisely known. By supporting arbitrary phase resynchronization, this disclosure allows for theoretically infinite bus-length and thus no limitation on device count, as well as arbitrary placement of devices along the bus. This ultimately allows support of multiple latency-domains for very long buses.
    Type: Application
    Filed: October 28, 2002
    Publication date: March 20, 2003
    Applicant: Rambus, Inc.
    Inventors: Jared LeVan Zerbe, Michael Tak-Kei Ching, Abhijit M. Abhyankar, Richard M. Barth, Andy Peng-Pui Chan, Paul G. Davis, William F. Stonecypher
  • Publication number: 20020196059
    Abstract: An output driver circuit and current control technique to facilitate high-speed buses with low noise is used to interface with high-speed dynamic RAMs (DRAMs). The architecture includes the following components: an input isolation block (120), an analog voltage divider (104), an input comparator (125), a sampling latch (130), a current control counter (115), and a bitwise output driver (output driver A 107 and output driver B 111).
    Type: Application
    Filed: August 29, 2002
    Publication date: December 26, 2002
    Inventors: Billy Wayne Garrett, John B. Dillon, Michael Tak-Kei Ching, William F. Stonecypher, Andy Peng-Pui Chan, Matthew M. Griffin, Nancy David Dillon
  • Patent number: 6473439
    Abstract: A method and circuit for achieving minimum latency data transfer between two mesochronous (same frequency, different phase) clock domains is disclosed. This circuit supports arbitrary phase relationships between two clock domains and is tolerant of temperature and voltage shifts after initialization while maintaining the same output data latency. In one embodiment, this circuit is used on a bus-system to re-time data from receive-domain, clocks to transmit-domain clocks. In such a system the phase relationships between these two clocks is set by the device bus location and thus is not precisely known. By supporting arbitrary phase resynchronization, this disclosure allows for theoretically infinite bus-length and thus no limitation on device count, as well as arbitrary placement of devices along the bus. This ultimately allows support of multiple latency-domains for very long buses.
    Type: Grant
    Filed: October 9, 1998
    Date of Patent: October 29, 2002
    Assignee: Rambus Incorporated
    Inventors: Jared LeVan Zerbe, Michael Tak-kei Ching, Abhijit M. Abhyankar, Richard M. Barth, Andy Peng-Pui Chan, Paul G. Davis, William F. Stonecypher
  • Patent number: 6462591
    Abstract: A semiconductor memory device including an array of memory cells. The memory device includes a first output driver coupled to a first output terminal, and a second output driver coupled to a second output terminal. The memory device further includes a voltage divider coupled between the first and second output terminals, to generate a control voltage based on a voltage level present on the first output terminal and a voltage level present on the second output terminal. The memory device further includes a comparator, coupled to the voltage divider, to compare the control voltage with a reference voltage, wherein an amount of voltage swing of the first output driver is adjusted based on the comparison between the control voltage and the reference voltage.
    Type: Grant
    Filed: June 14, 2001
    Date of Patent: October 8, 2002
    Assignee: Rambus Inc.
    Inventors: Billy Wayne Garrett, Jr., John B. Dillon, by Nancy David Dillon, Michael Tak-Kei Ching, William F. Stonecypher, Andy Peng-Pui Chan, Matthew M. Griffin
  • Publication number: 20020070771
    Abstract: An output driver circuit and current control technique to facilitate high-speed buses with low noise is used to interface with high-speed dynamic RAMs (DRAMs). The architecture includes the following components: an input isolation block (120), an analog voltage divider (104), an input comparator (125), a sampling latch (130), a current control counter (115), and a bitwise output driver (output driver A 107 and output driver B 111).
    Type: Application
    Filed: September 12, 2001
    Publication date: June 13, 2002
    Inventors: Billy Wayne Garrett, John B. Dillon, Michael Tak-Kei Ching, William F. Stonecypher, Andy Peng-Pui Chan, Matthew M. Griffin, Nancy David Dillon
  • Publication number: 20020043997
    Abstract: An output driver has an output multiplexor and an output current driver. The output multiplexor receives a data signal and outputs a q-node signal. The output current driver receives the q-node signal and drives a bus based on the q-node signal. The output multiplexor processes the data signal in various ways to generate the q-node signal. The output current driver is responsive to current control bits to select a amount of output drive current. In addition, the output multiplexor is controlled such that the output impedance of the output current driver is maintained within a predetermined range.
    Type: Application
    Filed: December 11, 2001
    Publication date: April 18, 2002
    Applicant: Rambus Inc.
    Inventors: Donald C. Stark, Jun Kim, Kurt T. Knorpp, Michael Tak-Kei Ching, Natsuki Kushiyama
  • Publication number: 20020017929
    Abstract: An output driver circuit and current control technique to facilitate high-speed buses with low noise is used to interface with high-speed dynamic RAMs (DRAMs). The architecture includes the following components: an input isolation block (120), an analog voltage divider (104), an input comparator (125), a sampling latch (130), a current control counter (115), and a bitwise output driver (output driver A 107 and output driver B 111).
    Type: Application
    Filed: June 14, 2001
    Publication date: February 14, 2002
    Inventors: Billy Wayne Garrett, John B. Dillon, Michael Tak-Kei Ching, William F. Stonecypher, Andy Peng-Pui Chan, Matthew M. Griffin, Nancy David Dillon