Patents by Inventor Charles L. Wang

Charles L. Wang 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: 20240097667
    Abstract: The present disclosure describes embodiments of driver circuit. The driver circuit includes a first impedance element electrically coupled to a first inverter circuit and a second impedance element electrically coupled to the first impedance element and a second inverter circuit. For a first encoding using the driver circuit, the first inverter circuit and the second inverter circuit are controlled such that a first current flows through the first and second impedance elements, the first current having a first value and a first direction. For a second encoding using the driver circuit, the first inverter circuit and the second inverter circuit are controlled such that a second current flows through the first and second impedance elements, the second current having a second value and a second direction. The first value is substantially the same as the second value and the first direction is opposite to the second direction.
    Type: Application
    Filed: September 15, 2022
    Publication date: March 21, 2024
    Applicant: Apple Inc.
    Inventors: Charles L. WANG, Yi-Hsiu E. CHEN, Pranavi SUNKARA
  • Patent number: 11764763
    Abstract: An Integrated Circuit includes a target circuit, first and second logic chains, a feedback path and calibration circuitry. The target circuit includes first and second inputs. The first and second logic chains propagate a signal from a common input point to the first and second inputs of the target circuit, respectively. The feedback path receives the signal from the first or second input and feeds the signal back to the common input point. The calibration circuitry is configured to connect the first input to the feedback path thereby forming a first closed-loop oscillator circuit, and measure a first oscillation frequency of the first closed-loop oscillator circuit, connect the second input to the feedback path, thereby forming a second closed-loop oscillator circuit, and measure a second oscillation frequency of the second closed-loop oscillator circuit, and verify a timing constraint responsively to the first and second oscillating frequencies.
    Type: Grant
    Filed: November 7, 2022
    Date of Patent: September 19, 2023
    Assignee: APPLE INC.
    Inventors: Yikun Chang, Charles L Wang, Chih-Yuan Chen
  • Patent number: 11165416
    Abstract: A system and method for efficient on-chip monitoring of clock signals post-silicon. An electronic circuit includes a post-silicon and on-die signal monitor and a first signal generator that sends a first signal with a first signal period to the signal monitor. The signal monitor selects a first sampling signal with a first sampling period such that a ratio of the first sampling period to the first signal period is greater than one and is a non-integer. The signal monitor selects a reference voltage level for indicating when the first signal is asserted. When the first sampling period has elapsed, the signal monitor samples the first signal to generate a voltage level, and upon completing sampling, determines a duty cycle of the generated voltage levels, which indicates a duty cycle of the first signal. Using a similar approach, the signal monitor is also capable of determining skew between two signals.
    Type: Grant
    Filed: December 3, 2019
    Date of Patent: November 2, 2021
    Assignee: Apple Inc.
    Inventors: Khaled M. Alashmouny, Dennis M. Fischette, Jr., Charles L. Wang, Samed Maltabas, Yikun Chang
  • Publication number: 20210167766
    Abstract: A system and method for efficient on-chip monitoring of clock signals post-silicon. An electronic circuit includes a post-silicon and on-die signal monitor and a first signal generator that sends a first signal with a first signal period to the signal monitor. The signal monitor selects a first sampling signal with a first sampling period such that a ratio of the first sampling period to the first signal period is greater than one and is a non-integer. The signal monitor selects a reference voltage level for indicating when the first signal is asserted. When the first sampling period has elapsed, the signal monitor samples the first signal to generate a voltage level, and upon completing sampling, determines a duty cycle of the generated voltage levels, which indicates a duty cycle of the first signal. Using a similar approach, the signal monitor is also capable of determining skew between two signals.
    Type: Application
    Filed: December 3, 2019
    Publication date: June 3, 2021
    Inventors: Khaled M. Alashmouny, Dennis M. Fischette, JR., Charles L. Wang, Samed Maltabas
  • Patent number: 6836852
    Abstract: Methods and systems for generating and synchronizing multiple clocks are disclosed herein that have extremely low skew across multiple channels and latency that is both minimal and well-defined. A phase-locked loop circuit generates a plurality of clock signals to synchronize channel circuits that receive core data streams. The channel circuits convert the core data streams into serial data streams. The phase-locked loop circuit or another phase-locked loop circuit generates a core clock signal for the registered transfer of the core data streams to the channel circuits. One or more of the plurality of clock signals may be distributed to the channel circuits by a register-to-register transfer.
    Type: Grant
    Filed: October 29, 2001
    Date of Patent: December 28, 2004
    Assignee: Agilent Technologies, Inc.
    Inventors: Charles L. Wang, Benny W. H. Lai, Charles E. Moore, Philip W. Fisher
  • Publication number: 20030084362
    Abstract: Methods and systems for generating and synchronizing multiple clocks are disclosed herein that have extremely low skew across multiple channels and latency that is both minimal and well-defined. A phase-locked loop circuit generates a plurality of clock signals to synchronize channel circuits that receive core data streams. The channel circuits convert the core data streams into serial data streams. The phase-locked loop circuit or another phase-locked loop circuit generates a core clock signal for the registered transfer of the core data streams to the channel circuits. One or more of the plurality of clock signals may be distributed to the channel circuits by a register-to-register transfer.
    Type: Application
    Filed: October 29, 2001
    Publication date: May 1, 2003
    Inventors: Charles L. Wang, Benny W. H. Lai, Charles E. Moore, Philip W. Fisher
  • Patent number: 6192093
    Abstract: A method and system for receiving CIMT encoded data transmitted in simplex mode. The receiver (12) is adapted to receive a stream of digital data and analyze successive portions thereof to identify a predetermined pattern of data. The receiver (12) outputs the received digital data in response to a detection of the predetermined pattern of data and, in the alternative, outputs other data in response to a failure to detect the predetermined pattern of data. In the illustrative embodiment, the stream of digital data is transmitted as conditional invert master transition encoded simplex data. The receiver (12) includes a CIMT decoder (16) which analyzes the input data to identify a master transition therein. The receiver (12) uses a local clock to analyze successive portions of the received data stream and word alignment logic to identify a master transition therein.
    Type: Grant
    Filed: July 30, 1999
    Date of Patent: February 20, 2001
    Assignee: Agilent Technologies
    Inventors: Benny W H Lai, Tony Lin, Charles L. Wang