Patents by Inventor Vishal Varma

Vishal Varma 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: 20240283436
    Abstract: A serial data receiver subsystem of a computer system includes a data rate detection circuit and a receiver circuit. The data rate detection circuit is configured to detect that a communication link operates in a high-speed mode rather than in a low-speed mode by detecting that a number of transitions in a serial data stream over a reference period of time exceeds a threshold value. The date rate detection circuit is further configured to activate a data rate detection signal indicating that the communication link operates in the high-speed mode, the data rate detection signal activated in response to detection that the number of transitions in the serial data stream over the reference period of time exceeds the threshold value. The receiver circuit is configured to activate one or more of a plurality of subcircuits included in the receiver circuit in response to activation of the data rate detection signal.
    Type: Application
    Filed: April 26, 2024
    Publication date: August 22, 2024
    Inventors: Vishal Varma, Dhaval H. Shah, Jose A. Tierno, Sanjeev K. Maheshwari, Sumeet Gupta
  • Patent number: 12028075
    Abstract: A serial data receiver subsystem included in a computer system may include a data detection circuit, a speed detection circuit, and a receiver circuit that includes multiple subcircuits. The data detection circuit performs a comparison of a reference voltage to the magnitude of signals received via a communication link that encodes a serial data stream consisting of multiple data symbols. Using a result of the comparison, the data detection circuit may activate a signal present indicator indicating the presence of data on the communication link. Once the signal present indicator is active, the speed detection circuit checks the number of transitions to determine a rate at which data is being transmitted. In response to a determination that the rate of the data being transmitted exceeds a threshold value, the receiver circuit activates one or more of the multiple subcircuits.
    Type: Grant
    Filed: August 31, 2022
    Date of Patent: July 2, 2024
    Assignee: Apple Inc.
    Inventors: Vishal Varma, Dhaval H. Shah, Jose A. Tierno, Sanjeev K. Maheshwari, Sumeet Gupta
  • Publication number: 20240179034
    Abstract: A receiver circuit including mechanisms for analog channel equalization and channel adaptation is disclosed. The receiver includes a front-end circuit configured to generate a filtered signal by performing filtering of an incoming signal that includes a stream of data symbols. A sample recovery circuit configured to sample an equalized signal, based on the filtered signal, to generate a plurality of recovered data symbols. A decision feedback equalization (DFE) circuit configured to generate the feedback signal based on the plurality of recovered data symbols. A logic circuit is configured to cause adjustment to one or more filters in the front-end circuit based on the plurality of recovered data symbols.
    Type: Application
    Filed: January 2, 2024
    Publication date: May 30, 2024
    Inventors: Lizhi Zhong, Vishal Varma, Yu Chen, Wenyi Jin
  • Patent number: 11902059
    Abstract: A receiver circuit including mechanisms for analog channel equalization and channel adaptation is disclosed. The receiver includes a front-end circuit configured to generate a filtered signal by performing filtering of an incoming signal that includes a stream of data symbols. A sample recovery circuit configured to sample an equalized signal, based on the filtered signal, to generate a plurality of recovered data symbols. A decision feedback equalization (DFE) circuit configured to generate the feedback signal based on the plurality of recovered data symbols. A logic circuit is configured to cause adjustment to one or more filters in the front-end circuit based on the plurality of recovered data symbols.
    Type: Grant
    Filed: May 27, 2022
    Date of Patent: February 13, 2024
    Assignee: Apple Inc.
    Inventors: Lizhi Zhong, Vishal Varma, Yu Chen, Wenyi Jin
  • Publication number: 20230388162
    Abstract: A receiver circuit including mechanisms for analog channel equalization and channel adaptation is disclosed. The receiver includes a front-end circuit configured to generate a filtered signal by performing filtering of an incoming signal that includes a stream of data symbols. A sample recovery circuit configured to sample an equalized signal, based on the filtered signal, to generate a plurality of recovered data symbols. A decision feedback equalization (DFE) circuit configured to generate the feedback signal based on the plurality of recovered data symbols. A logic circuit is configured to cause adjustment to one or more filters in the front-end circuit based on the plurality of recovered data symbols.
    Type: Application
    Filed: May 27, 2022
    Publication date: November 30, 2023
    Inventors: Lizhi Zhong, Vishal Varma, Yu Chen, Wenyi Jin
  • Publication number: 20230387898
    Abstract: A serial data receiver subsystem included in a computer system may include a data detection circuit, a speed detection circuit, and a receiver circuit that includes multiple subcircuits. The data detection circuit performs a comparison a reference voltage to the magnitude of signals received via a communication link that encode a serial data stream consisting of multiple data symbols. Using a result of the comparison, the data detection circuit may activate a indicating the presence of data on the communication link. Once the is active, the speed detection circuit checks the number of transitions to determine a rate at which data is being transmitted. In response to a determination that the rate of the data being transmitted exceeds a threshold value, the receiver circuit activates one or more of the multiple subcircuits.
    Type: Application
    Filed: August 31, 2022
    Publication date: November 30, 2023
    Inventors: Vishal Varma, Dhaval H. Shah, Jose A. Tierno, Sanjeev K. Maheshwari, Sumeet Gupta
  • Patent number: 11664809
    Abstract: An apparatus includes a receiver buffer, a phase compensation circuit, a data sampler circuit, and an error sampler circuit. The receiver buffer may generate an equalized signal on a signal node using an input signal received via a channel. The phase compensation circuit may, in response to an initiation of a training mode, replace the equalized signal on the signal node with a reference signal. The data sampler circuit may sample, using a data clock signal, the reference signal to generate a plurality of data samples. The error sampler circuit may sample, using an error clock signal, the reference signal to generate a plurality of errors samples. The phase compensation circuit may also adjust a phase difference between the data clock signal and the error clock signal using at least some of the plurality of data samples and at least some of the plurality of error samples.
    Type: Grant
    Filed: April 5, 2021
    Date of Patent: May 30, 2023
    Assignee: Apple Inc.
    Inventors: Jaeduk Han, Wenbo Liu, Wing Liu, Ming-Shuan Chen, Sanjeev K. Maheshwari, Vishal Varma, Sunil Bhosekar, Lizhi Zhong, Gary A. Rogan
  • Publication number: 20210226639
    Abstract: An apparatus includes a receiver buffer, a phase compensation circuit, a data sampler circuit, and an error sampler circuit. The receiver buffer may generate an equalized signal on a signal node using an input signal received via a channel. The phase compensation circuit may, in response to an initiation of a training mode, replace the equalized signal on the signal node with a reference signal. The data sampler circuit may sample, using a data clock signal, the reference signal to generate a plurality of data samples. The error sampler circuit may sample, using an error clock signal, the reference signal to generate a plurality of errors samples. The phase compensation circuit may also adjust a phase difference between the data clock signal and the error clock signal using at least some of the plurality of data samples and at least some of the plurality of error samples.
    Type: Application
    Filed: April 5, 2021
    Publication date: July 22, 2021
    Inventors: Jaeduk Han, Wenbo Liu, Wing Liu, Ming-Shuan Chen, Sanjeev K. Maheshwari, Vishal Varma, Sunil Bhosekar, Lizhi Zhong, Gary A. Rogan
  • Patent number: 10972107
    Abstract: An apparatus includes a receiver buffer, a phase compensation circuit, a data sampler circuit, and an error sampler circuit. The receiver buffer may generate an equalized signal on a signal node using an input signal received via a channel. The phase compensation circuit may, in response to an initiation of a training mode, replace the equalized signal on the signal node with a reference signal. The data sampler circuit may sample, using a data clock signal, the reference signal to generate a plurality of data samples. The error sampler circuit may sample, using an error clock signal, the reference signal to generate a plurality of errors samples. The phase compensation circuit may also adjust a phase difference between the data clock signal and the error clock signal using at least some of the plurality of data samples and at least some of the plurality of error samples.
    Type: Grant
    Filed: July 31, 2019
    Date of Patent: April 6, 2021
    Assignee: Apple Inc.
    Inventors: Jaeduk Han, Wenbo Liu, Wing Liu, Ming-Shuan Chen, Sanjeev K. Maheshwari, Vishal Varma, Sunil Bhosekar, Lizhi Zhong, Gary A. Rogan
  • Publication number: 20210036707
    Abstract: An apparatus includes a receiver buffer, a phase compensation circuit, a data sampler circuit, and an error sampler circuit. The receiver buffer may generate an equalized signal on a signal node using an input signal received via a channel. The phase compensation circuit may, in response to an initiation of a training mode, replace the equalized signal on the signal node with a reference signal. The data sampler circuit may sample, using a data clock signal, the reference signal to generate a plurality of data samples. The error sampler circuit may sample, using an error clock signal, the reference signal to generate a plurality of errors samples. The phase compensation circuit may also adjust a phase difference between the data clock signal and the error clock signal using at least some of the plurality of data samples and at least some of the plurality of error samples.
    Type: Application
    Filed: July 31, 2019
    Publication date: February 4, 2021
    Inventors: Jaeduk Han, Wenbo Liu, Wing Liu, Ming-Shuan Chen, Sanjeev K. Maheshwari, Vishal Varma, Sunil Bhosekar, Lizhi Zhong, Gary A. Rogan
  • Publication number: 20070173254
    Abstract: Cell reselection comprises monitoring a first indicator indicative of a signaling level of the serving cell, and monitoring second indicators, each indicative of a signaling level of one of plural potential target cells. A timer associated with a potential target cell is initiated when the respective second indicator indicates that the signaling level of the potential target cell is better than the signaling level of the serving cell. Each timer has an associated expiry, and, if at least one timer has been initiated by the expiry of another initiated timer, then, after delaying for an additional period after at least the first timer has expired, a target cell is selected from the potential target cells. The target cell is selected that has a second indicator which indicates that the signaling level of the respective target cell is better than the signaling level of the serving cell.
    Type: Application
    Filed: January 26, 2006
    Publication date: July 26, 2007
    Inventors: Nicholas Tebbit, Amit Agarwal, Mohit Narang, Vishal Varma