Patents by Inventor Venkata Ramana Malladi

Venkata Ramana Malladi 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: 11217285
    Abstract: A memory subsystem and method for performing calibrations therein is disclosed. A memory subsystem includes a memory controller coupled to a memory by a plurality of signal paths. The memory controller is configured to perform an initial calibration to determine respective eye patterns corresponding to the ones of the plurality of signal paths. For a subsequent calibrations, updated eye patterns are determined for a subset of the plurality of signal paths. Remaining ones of the plurality of signal paths (not included in the subset), are not active during the subsequent calibrations. Updated eye patterns for the remaining ones of the plurality of signal paths are determined based on information obtained during the initial calibration and information from signal paths in the subset designated proxies for the remaining ones of the plurality of signal paths.
    Type: Grant
    Filed: August 5, 2020
    Date of Patent: January 4, 2022
    Assignee: Apple Inc.
    Inventors: Robert E. Jeter, Rakesh L. Notani, Kai Lun Hsiung, Venkata Ramana Malladi, Rahul Ranjan, Naveen Kumar Korada
  • Patent number: 10515028
    Abstract: An apparatus and method for encoding data are disclosed that may allow for performing periodic calibration operations on a communication link. A controller may determine multiple possible values for a reference voltage used with the communication link based on an initial value. Calibration operations may be performed using each possible value, and the results of the operations scored based on the width of data eyes measured during the calibration operations. The controller may then select a new value for the reference voltage from the multiple possible values dependent upon the scores of each of the multiple possible values.
    Type: Grant
    Filed: July 9, 2018
    Date of Patent: December 24, 2019
    Assignee: Apple Inc.
    Inventors: Robert E. Jeter, Brijesh Tripathi, Kiran Kattel, Rakesh L. Notani, Fabien S. Faure, Sukalpa Biswas, Kai Lun Hsiung, Neeraj Parik, Venkata Ramana Malladi, Shiva Kumar, Chaitanya Polapragada, Allen Kim
  • Publication number: 20190042492
    Abstract: An apparatus and method for encoding data are disclosed that may allow for performing periodic calibration operations on a communication link. A controller may determine multiple possible values for a reference voltage used with the communication link based on an initial value. Calibration operations may be performed using each possible value, and the results of the operations scored based on the width of data eyes measured during the calibration operations. The controller may then select a new value for the reference voltage from the multiple possible values dependent upon the scores of each of the multiple possible values.
    Type: Application
    Filed: July 9, 2018
    Publication date: February 7, 2019
    Inventors: Robert E. Jeter, Brijesh Tripathi, Kiran Kattel, Rakesh L. Notani, Fabien S. Faure, Sukalpa Biswas, Kai Lun Hsiung, Neeraj Parik, Venkata Ramana Malladi, Shiva Kumar, Chaitanya Polapragada, Allen Kim
  • Patent number: 10175905
    Abstract: Systems, apparatuses, and methods for improved memory controller power management techniques. An apparatus includes control logic, one or more memory controller(s), and one or more memory devices. If the amount of traffic and/or queue depth for a given memory controller falls below a threshold, the clock frequency supplied to the given memory controller and corresponding memory device(s) is reduced. In one embodiment, the clock frequency is reduced by one half. If the amount of traffic and/or queue depth rises above the threshold, then the clock frequency is increased back to its original frequency. The clock frequency may be adjusted by doubling the divisor used by a clock divider, which enables fast switching between the original rate and the reduced rate. This in turn allows for more frequent switching between the low power and normal power states, resulting in the memory controller and memory device operating more efficiently.
    Type: Grant
    Filed: September 13, 2016
    Date of Patent: January 8, 2019
    Assignee: Apple Inc.
    Inventors: Robert E. Jeter, Liang Deng, Kai Lun Hsiung, Manu Gulati, Rakesh L. Notani, Sukalpa Biswas, Venkata Ramana Malladi, Gregory S. Mathews, Enming Zheng, Fabien S. Faure
  • Patent number: 10019387
    Abstract: An apparatus and method for encoding data are disclosed that may allow for performing periodic calibration operations on a communication link. A controller may determine multiple possible values for a reference voltage used with the communication link based on an initial value. Calibration operations may be performed using each possible value, and the results of the operations scored based on the width of data eyes measured during the calibration operations. The controller may then select a new value for the reference voltage from the multiple possible values dependent upon the scores of each of the multiple possible values.
    Type: Grant
    Filed: April 1, 2015
    Date of Patent: July 10, 2018
    Assignee: Apple Inc.
    Inventors: Robert E. Jeter, Brijesh Tripathi, Kiran Kattel, Rakesh L. Notani, Fabien S. Faure, Sukalpa Biswas, Kai Lun Hsiung, Neeraj Parik, Venkata Ramana Malladi, Shiva Kumar, Chaitanya Polapragada, Allen Kim
  • Publication number: 20180074743
    Abstract: Systems, apparatuses, and methods for improved memory controller power management techniques. An apparatus includes control logic, one or more memory controller(s), and one or more memory devices. If the amount of traffic and/or queue depth for a given memory controller falls below a threshold, the clock frequency supplied to the given memory controller and corresponding memory device(s) is reduced. In one embodiment, the clock frequency is reduced by one half If the amount of traffic and/or queue depth rises above the threshold, then the clock frequency is increased back to its original frequency. The clock frequency may be adjusted by doubling the divisor used by a clock divider, which enables fast switching between the original rate and the reduced rate. This in turn allows for more frequent switching between the low power and normal power states, resulting in the memory controller and memory device operating more efficiently.
    Type: Application
    Filed: September 13, 2016
    Publication date: March 15, 2018
    Inventors: Robert E. Jeter, Liang Deng, Kai Lun Hsiung, Manu Gulati, Rakesh L. Notani, Sukalpa Biswas, Venkata Ramana Malladi, Gregory S. Mathews, Enming Zheng, Fabien S. Faure
  • Patent number: 9824772
    Abstract: A method of training chip select for a memory module. The method includes programming a memory controller into a mode wherein a command signal is active for a programmable time period. The method then programs a programmable delay line of the chip select with a delay value and performs initialization of the memory module. A read command is then sent to the memory module to toggle a state of the chip select. A number of data strobe signals sent by the memory module in response to the read command are counted. A determination is made whether the memory module is in a pass state or an error state based on a result of the counting.
    Type: Grant
    Filed: December 26, 2012
    Date of Patent: November 21, 2017
    Assignee: NVIDIA CORPORATION
    Inventors: Venkata Ramana Malladi, Tony Yuhsiang Cheng, Sharath Raghava, Ambuj Kumar, Arunjit Sahni, Paul Lam
  • Patent number: 9698797
    Abstract: Techniques are disclosed relating to feedback-controlled oscillators (e.g., phase-locked loops) arranged in two or more levels. In some embodiments, in a relatively higher-frequency mode, a first level feedback-controlled oscillator provides reference signals to one or more second level feedback-controlled oscillators that in turn generate output clock signals to clock sequential circuitry. In some embodiments, in a relatively lower-frequency mode, the first level feedback-controlled oscillator bypasses the second level feedback-controlled oscillators and provides output clock signals directly to sequential circuitry (without using any intervening feedback-controlled oscillators).
    Type: Grant
    Filed: July 14, 2016
    Date of Patent: July 4, 2017
    Assignee: Apple Inc.
    Inventors: Manu Gulati, Suhas Kumar Suvarna Ramesh, Venkata Ramana Malladi, Thomas H. Huang, Rakesh L. Notani, Robert E. Jeter, Kai Lun Hsiung
  • Patent number: 9607714
    Abstract: A method of training a command signal for a memory module. The method includes programming a memory controller into a mode where a single bit of an address signal is active for a single clock cycle. The method then programs a programmable delay line of the address signal with a delay value and performs initialization of the memory module. The memory module is then placed in a write leveling mode. A write leveling procedure is then performed and a response to the write leveling procedure is determined from the memory module. A determination is made whether the memory module is in a pass state or an error state based on the response.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: March 28, 2017
    Assignee: NVIDIA CORPORATION
    Inventors: Venkata Ramana Malladi, Tony Yuhsiang Cheng, Sharath Raghava, Ambuj Kumar, Arunjit Sahni, Paul Lam
  • Publication number: 20160292094
    Abstract: An apparatus and method for encoding data are disclosed that may allow for performing periodic calibration operations on a communication link. A controller may determine multiple possible values for a reference voltage used with the communication link based on an initial value. Calibration operations may be performed using each possible value, and the results of the operations scored based on the width of data eyes measured during the calibration operations. The controller may then select a new value for the reference voltage from the multiple possible values dependent upon the scores of each of the multiple possible values.
    Type: Application
    Filed: April 1, 2015
    Publication date: October 6, 2016
    Inventors: Robert E. Jeter, Brijesh Tripathi, Kiran Kattel, Rakesh L. Notani, Fabien S. Faure, Sukalpa Biswas, Kai Lun Hsiung, Neeraj Parik, Venkata Ramana Malladi, Shiva Kumar, Chaitanya Polapragada, Allen Kim
  • Patent number: 9368169
    Abstract: A method of training chip select for a memory module. The method includes programming a memory controller into a mode wherein a command signal is active for a programmable time period. The method then programs a programmable delay line of the chip select with a delay value and performs initialization of the memory module. The memory module is then placed in a write leveling mode wherein placing the memory module in the write leveling mode toggles a state of the chip select. A write leveling procedure is then performed and a response thereto is determined from the memory module. A determination is made whether the memory module is in a pass state or an error state based on the response.
    Type: Grant
    Filed: December 26, 2012
    Date of Patent: June 14, 2016
    Assignee: NVIDIA CORPORATION
    Inventors: Venkata Ramana Malladi, Tony Yuhsiang Cheng, Sharath Raghava, Ambuj Kumar, Arunjit Sahni, Paul Lam
  • Publication number: 20140181452
    Abstract: A method of training command signals for a memory module. The method includes programming a memory controller into a mode wherein a column access strobe is active for a single clock cycle. The method then programs a programmable delay line of the column access strobe with a delay value and performs initialization of the memory module. A read command is then sent to the memory module. A number of data strobe signals sent by the memory module in response to the read command are counted. A determination is made whether the memory module is in a pass state or an error state based on a result of the counting.
    Type: Application
    Filed: December 27, 2012
    Publication date: June 26, 2014
    Applicant: NVIDIA CORPORATION
    Inventors: Venkata Ramana Malladi, Tony Yuhsiang Cheng, Sharath Raghava, Ambuj Kumar, Arunjit Sahni, Paul Lam
  • Publication number: 20140181451
    Abstract: A method of training a command signal for a memory module. The method includes programming a memory controller into a mode wherein a single bit of an address signal is active for a single clock cycle. The method then programs a programmable delay line of the address signal with a delay value and performs initialization of the memory module. The memory module is then placed in a write leveling mode. A write leveling procedure is then performed and a response thereto is determined from the memory module. A determination is made whether the memory module is in a pass state or an error state based on the response.
    Type: Application
    Filed: December 27, 2012
    Publication date: June 26, 2014
    Applicant: NVIDIA CORPORATION
    Inventors: Venkata Ramana Malladi, Tony Yuhsiang Cheng, Sharath Raghava, Ambuj Kumar, Arunjit Sahni, Paul Lam
  • Publication number: 20140181391
    Abstract: A method of training chip select for a memory module. The method includes programming a memory controller into a mode wherein a command signal is active for a programmable time period. The method then programs a programmable delay line of the chip select with a delay value and performs initialization of the memory module. The memory module is then placed in a write leveling mode wherein placing the memory module in the write leveling mode toggles a state of the chip select. A write leveling procedure is then performed and a response thereto is determined from the memory module. A determination is made whether the memory module is in a pass state or an error state based on the response.
    Type: Application
    Filed: December 26, 2012
    Publication date: June 26, 2014
    Applicant: NVIDIA CORPORATION
    Inventors: Venkata Ramana Malladi, Tony Yuhsiang Cheng, Sharath Raghava, Ambuj Kumar, Arunjit Sahni, Paul Lam
  • Publication number: 20140181429
    Abstract: A method of training a memory interface between a memory controller and a memory module. The method includes programming a delay line of a data strobe with a delay value and programming a reference voltage with a voltage value. The method then writes a data bit pattern to the memory module wherein the data bit pattern is of a first plurality of unique data bit patterns. The data bit pattern is read back and a result is compared with the data bit pattern. A determination is made whether the memory module is in a pass state or an error state based on the comparing. The steps are repeated with another data bit pattern of the first plurality of data bit patterns. The method is repeated for each combination of the data strobe delay value and the reference voltage value.
    Type: Application
    Filed: December 26, 2012
    Publication date: June 26, 2014
    Applicant: NVIDIA CORPORATION
    Inventors: Venkata Ramana Malladi, Tony Yuhsiang Cheng, Ambuj Kumar, Brian Keith Langendorf
  • Publication number: 20140181392
    Abstract: A method of training chip select for a memory module. The method includes programming a memory controller into a mode wherein a command signal is active for a programmable time period. The method then programs a programmable delay line of the chip select with a delay value and performs initialization of the memory module. A read command is then sent to the memory module to toggle a state of the chip select. A number of data strobe signals sent by the memory module in response to the read command are counted. A determination is made whether the memory module is in a pass state or an error state based on a result of the counting.
    Type: Application
    Filed: December 26, 2012
    Publication date: June 26, 2014
    Applicant: NVIDIA CORPORATION
    Inventors: Venkata Ramana Malladi, Tony Yuhsiang Cheng, Sharath Raghava, Ambuj Kumar, Arunjit Sahni, Paul Lam