Patents by Inventor Thucydides Xanthopoulos

Thucydides Xanthopoulos 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: 11669419
    Abstract: A system for performing a failure assessment of an IC may comprise a hardware subsystem and a control subsystem to control operations performed by the hardware subsystem. The hardware system may change a duration of cycles of a clocking signal on the IC, and stop the clocking signal at a selected clock cycle. The operations may comprise changing the duration of selected clock cycles across a block of clock cycles, and performing a binary search across the block of clock cycles, such that the selected clock cycles are temporally placed at selected different locations within the block of clock cycles. At each iteration of the binary search, the system determines when a failure occurs. When the binary search indicates a single clock cycle causing a failure, the system stops clocking transitions at the single clock cycle, and the system extracts data from one or more circuit components of the IC.
    Type: Grant
    Filed: November 26, 2019
    Date of Patent: June 6, 2023
    Assignee: MARVELL ASIA PTE, LTD.
    Inventors: Zahi Abuhamdeh, Nitin Mohan, Kandadi Vasudevan, Thucydides Xanthopoulos, Tyler Albarran, Peter Rickenbach
  • Patent number: 11545987
    Abstract: In an embodiment, a method includes initializing an input clock rotating register by sending a reset signal synchronized to an input clock signal and initializing an output clock rotating register by sending the reset signal synchronized to an output clock signal. The method further providing a data input synchronized to the output clock to a plurality of mux-flops. The output clock rotating register activates one of the plurality of mux-flops to receive the data input. The method further includes forwarding the data input via the one of the plurality of mux-flops to a multiplexer. The multiplexer has a selection input of the input clock rotating register. The method further includes selecting the data input as the output of the multiplexer to be a data output signal, such that the data output is synchronized with the input clock.
    Type: Grant
    Filed: December 10, 2019
    Date of Patent: January 3, 2023
    Assignee: Marvell Asia Pte, Ltd.
    Inventors: Nitin Mohan, Vasudevan Kandadi, Thucydides Xanthopoulos
  • Patent number: 11545981
    Abstract: A delay-locked loop (DLL) and corresponding method improve frequency of a chip. The DLL comprises a first programmable delay element configured to output a first clock, a second programmable delay element configured to output a second clock a phase detector. The phase detector includes a first clock input and a second clock input. The first and second programmable delay elements are further configured, in combination, to introduce a controllable skew between the first and second clocks. The DLL is configured to input the first and second clocks to the first and second clock inputs of the phase detector, respectively. The controllable skew is configured to improve the frequency of the chip.
    Type: Grant
    Filed: July 31, 2019
    Date of Patent: January 3, 2023
    Assignee: MARVELL ASIA PTE, LTD.
    Inventors: Thucydides Xanthopoulos, Nitin Mohan
  • Patent number: 11402413
    Abstract: In an embodiment, a method includes filtering, with a low-pass filter, a voltage signal (Vdd) of a chip to create a filtered signal (Vref). The method further includes dividing Vref by a given factor. The method further includes determining whether a voltage droop occurred in Vdd by comparing Vdd to the divided Vref. The method further includes outputting a droop detection signal if Vdd is less than the divided Vref. In an embodiment, dividing Vref by the given factor includes selecting, with a multiplexer, one of a plurality of divided Vref signals outputted by a voltage divider. The selecting is based on a selection signal.
    Type: Grant
    Filed: December 5, 2019
    Date of Patent: August 2, 2022
    Assignee: Marvell Asia Pte, Ltd.
    Inventors: Nitin Mohan, Thucydides Xanthopoulos
  • Patent number: 10784871
    Abstract: A circuit and corresponding method for dynamic voltage frequency scaling (DVFS) on a chip employ a delay-locked loop (DLL)-based clocking architecture. The circuit comprises a DLL including a fixed delay line path, with a first insertion delay, and variable delay line path, with a second insertion delay, and a clock generator. The clock generator is configured to source a DLL input clock to the fixed and variable delay line paths at a start-up frequency prior to a run-time frequency. The start-up frequency is lower relative to a target frequency for the chip. The run-time frequency is configured based on DVFS, following release of the chip from reset. The chip is configured to be released from reset with the DLL locked at the start-up frequency, enabling the second insertion delay to match the first insertion delay with the DLL locked at the start-up frequency.
    Type: Grant
    Filed: July 31, 2019
    Date of Patent: September 22, 2020
    Assignee: MARVELL ASIA PTE, LTD.
    Inventors: Thucydides Xanthopoulos, Nitin Mohan
  • Patent number: 10530370
    Abstract: A circuit and corresponding method enable glitch-free frequency. The circuit comprises a first delay circuit and a second delay circuit, configured to produce first and second propagated enables, respectively, from first and second input enables, respectively; and an output clock circuit. The output clock circuit is configured to produce an output clock that switches, glitch-free, between a first phase-locked clock and a second phase-locked. The first and second delay circuits are further configured to enable the output clock to be switched, glitch-free, by employing the second propagated enable to gate propagation of the first input enable and the first propagated enable to gate propagation of the second input enable, respectively. The first and second input enables are configured to be enabled, alternately, causing the output clock to switch between the first and second phase-locked clocks.
    Type: Grant
    Filed: December 4, 2018
    Date of Patent: January 7, 2020
    Assignee: Marvell International Ltd.
    Inventors: Nitin Mohan, Georgios Faldamis, Thucydides Xanthopoulos
  • Patent number: 9721627
    Abstract: A method and corresponding apparatus for aligning a data signal with a corresponding clock signal include oversampling the data signal based on the corresponding clock signal and generating corresponding data samples. An indication of skew between the data signal and the corresponding clock signal is detected based on data samples. A variable delay line coupled to the data signal is then adjusted based on the indication of skew detected. According to at least one example implementation, the data signal is oversampled based on the corresponding clock signal and multiple time-shifted versions of the corresponding clock signal. At least one signal of the corresponding clock signal and the multiple time-shifted versions of the corresponding clock signal is employed in sampling the data signal at a potential transition edge of the data signal.
    Type: Grant
    Filed: October 4, 2013
    Date of Patent: August 1, 2017
    Assignee: Cavium, Inc.
    Inventors: Thucydides Xanthopoulos, David D. Lin, Edward W. Thoenes
  • Patent number: 9570128
    Abstract: An apparatus for controlling memory includes a memory controller, and an interface to data lines connecting it to memory. Each line carries a signal that corresponds to a bit to be written to memory. The interface includes, for each line, circuitry for transmitting a bit to memory via the line, and a data de-skewer. For each line, the de-skewer receives a first data signal that represents a bit to be written. Each line has an inherent skew. The de-skewer generates a second data signal by applying a skew to the first. A selected extent of skew increases a likelihood of sampling the second data signal during a data-valid window thereof. The same de-skewer receives and skews a first data bit read from the memory.
    Type: Grant
    Filed: November 14, 2014
    Date of Patent: February 14, 2017
    Assignee: Cavium, Inc.
    Inventors: David Da-Wei Lin, Edward Wade Thoenes, Thucydides Xanthopoulos
  • Patent number: 9483100
    Abstract: According to at least one example embodiment, a semiconductor device is configured to gate power supply to a hardware component through a transistor coupled to the hardware component. The transistor is operated by a controller in a manner to limit electric current dissipated to the hardware component during a transition period. The controller is configured to gradually turn on, or off, the hardware component during a transition period by controlling at least one input signal to the transistor. Gradual turning on, or off, of the hardware component reduces electric current leakage through the hardware component and diminishes any potential disturbance to a ground reference coupled to the hardware component.
    Type: Grant
    Filed: February 28, 2014
    Date of Patent: November 1, 2016
    Assignee: Cavium, Inc.
    Inventors: David A. Carlson, Thucydides Xanthopoulos
  • Publication number: 20160141012
    Abstract: An apparatus for controlling memory includes a memory controller, and an interface to data lines connecting it to memory. Each line carries a signal that corresponds to a bit to be written to memory. The interface includes, for each line, circuitry for transmitting a bit to memory via the line, and a data de-skewer. For each line, the de-skewer receives a first data signal that represents a bit to be written. Each line has an inherent skew. The de-skewer generates a second data signal by applying a skew to the first. A selected extent of skew increases a likelihood of sampling the second data signal during a data-valid window thereof. The same de-skewer receives and skews a first data bit read from the memory.
    Type: Application
    Filed: November 14, 2014
    Publication date: May 19, 2016
    Inventors: David Lin, Edward Wade Thoenes, Thucydides Xanthopoulos
  • Patent number: 9263151
    Abstract: A memory interface enables AC characterization under test conditions without requiring the use of Automated Test Equipment (ATE) and functional patterns. The memory controller may be configured to generate output patterns through the test interface and create a loopback path for input specification testing using an external stressed-eye random number generator and checker. As a result, the memory interface may be evaluated for electrical and timing specifications under a relatively simple test setup and test procedure through the test interface (JTAG), as opposed to a complex processor program that sets up a similar memory access pattern on Automated Test Equipment (ATE).
    Type: Grant
    Filed: February 15, 2012
    Date of Patent: February 16, 2016
    Assignee: Cavium, Inc.
    Inventors: Thucydides Xanthopoulos, David Lin
  • Publication number: 20150248154
    Abstract: According to at least one example embodiment, a semiconductor device is configured to gate power supply to a hardware component through a transistor coupled to the hardware component. The transistor is operated by a controller in a manner to limit electric current dissipated to the hardware component during a transition period. The controller is configured to gradually turn on, or off, the hardware component during a transition period by controlling at least one input signal to the transistor. Gradual turning on, or off, of the hardware component reduces electric current leakage through the hardware component and diminishes any potential disturbance to a ground reference coupled to the hardware component.
    Type: Application
    Filed: February 28, 2014
    Publication date: September 3, 2015
    Applicant: Cavium, Inc.
    Inventors: David A. Carlson, Thucydides Xanthopoulos
  • Publication number: 20150100815
    Abstract: A method and corresponding apparatus for aligning a data signal with a corresponding clock signal include oversampling the data signal based on the corresponding clock signal and generating corresponding data samples. An indication of skew between the data signal and the corresponding clock signal is detected based on data samples. A variable delay line coupled to the data signal is then adjusted based on the indication of skew detected. According to at least one example implementation, the data signal is oversampled based on the corresponding clock signal and multiple time-shifted versions of the corresponding clock signal. At least one signal of the corresponding clock signal and the multiple time-shifted versions of the corresponding clock signal is employed in sampling the data signal at a potential transition edge of the data signal.
    Type: Application
    Filed: October 4, 2013
    Publication date: April 9, 2015
    Applicant: Cavium, Inc.
    Inventors: Thucydides Xanthopoulos, David D. Lin, Edward W. Thoenes
  • Patent number: 8634509
    Abstract: A high-linearity Phase Interpolator based Clock and Data Recovery (CDR) circuit for use in a multi-standard Serializer/Deserializer (SerDes) is provided. By interpolating at a high, fixed frequency for all supported data rates and then dividing the output clock down to the appropriately frequency for each standard, the Phase Interpolator can provide for maximum phase linearity while reducing its sensitivity to noise.
    Type: Grant
    Filed: February 15, 2012
    Date of Patent: January 21, 2014
    Assignee: Cavium, Inc.
    Inventors: Ethan Crain, Thomas F. Hummel, Thucydides Xanthopoulos, Scott Meninger
  • Publication number: 20120207259
    Abstract: A high-linearity Phase Interpolator based Clock and Data Recovery (CDR) circuit for use in a multi-standard Serializer/Deserializer (SerDes) is provided. By interpolating at a high, fixed frequency for all supported data rates and then dividing the output clock down to the appropriately frequency for each standard, the Phase Interpolator can provide for maximum phase linearity while reducing its sensitivity to noise.
    Type: Application
    Filed: February 15, 2012
    Publication date: August 16, 2012
    Applicant: Cavium, Inc.
    Inventors: Ethan Crain, Thomas F. Hummel, Thucydides Xanthopoulos, Scott Meninger
  • Publication number: 20120210179
    Abstract: A memory interface enables AC characterization under test conditions without requiring the use of automated test equipment (ATE) and functional patterns. The memory controller may be configured to generate output patterns through the test interface and create a loopback path for input specification testing using an external stressed-eye random number generator and checker. As a result, the memory interface may be evaluated for electrical and timing specifications under a relatively simple test setup and test procedure through the test interface (JTAG), as opposed to a complex processor program that sets up a similar memory access pattern on Automated Test Equipment (ATE).
    Type: Application
    Filed: February 15, 2012
    Publication date: August 16, 2012
    Applicant: Cavium, Inc.
    Inventors: Thucydides Xanthopoulos, David Lin
  • Patent number: 7209531
    Abstract: A deskew circuit utilizing a coarse delay adjustment and fine delay adjustment centers the received data in a proper data window and aligns the data for proper sampling. In one scheme, bit state transitions of a training sequence for SPI-4 protocol is used to adjust delays to align the transition points.
    Type: Grant
    Filed: March 26, 2003
    Date of Patent: April 24, 2007
    Assignee: Cavium Networks, Inc.
    Inventors: Daniel A. Katz, Richard E. Kessler, Thucydides Xanthopoulos
  • Publication number: 20020079937
    Abstract: A delay-locked loop includes two delay lines. One line provides variable coarse delay adjustments, while the other delay provides variable fine delay adjustments. By providing two delay lines—one coarse and one fine—the dual delay line configuration of the preferred DLL allows the DLL to exhibit a wide dynamic range to accommodate large on-chip process delay deviations among the clocks to be matched and at the same time exhibit fine-grain delay settings to enable accurate phase matching between the clocks.
    Type: Application
    Filed: September 5, 2001
    Publication date: June 27, 2002
    Inventor: Thucydides Xanthopoulos