Patents by Inventor Liji Gopalakrishnan

Liji Gopalakrishnan 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: 11599483
    Abstract: A memory system includes a dynamic random access memory (DRAM) device, a second memory device, and a memory controller circuit. The memory controller circuit is coupled to the DRAM device by a first data channel configured to transfer first data between the memory controller circuit and the DRAM device on behalf of a host, and is also coupled to the DRAM device by a second data channel configured to transfer second data between the memory controller circuit and the DRAM device on behalf of the second memory device while the first data is being transferred across the first data bus.
    Type: Grant
    Filed: January 21, 2022
    Date of Patent: March 7, 2023
    Assignee: Rambus Inc.
    Inventor: Liji Gopalakrishnan
  • Patent number: 11587605
    Abstract: An integrated circuit includes a physical layer interface having a control timing domain and a data timing domain, and circuits that enable the control timing domain during a change in power conservation mode in response to a first event, and that enable the data timing domain in response to a second event. The control timing domain can include interface circuits coupled to a command and address path, and the data timing domain can include interface circuits coupled to a data path.
    Type: Grant
    Filed: June 7, 2021
    Date of Patent: February 21, 2023
    Assignee: Rambus Inc.
    Inventors: Ian Shaeffer, Lei Luo, Liji Gopalakrishnan
  • Publication number: 20230052053
    Abstract: A single-ended receiver is coupled to an input-output (I/O) pin of a command and address (CA) bus. The receiver is configurable with dual-mode I/O support to operate the CA bus in a low-swing mode and a high-swing mode. The receiver is configurable to receive a first command on the I/O pin while in the high-swing mode, initiate calibration of the slave device to operate in the low-swing mode in response to the first command, switch the slave device to operate in the low-swing mode while the CA bus remains active, and to receive a second command on the I/O pin while in the low-swing mode.
    Type: Application
    Filed: June 24, 2022
    Publication date: February 16, 2023
    Inventors: Pravin Kumar Venkatesan, Liji Gopalakrishnan, Kashinath Ullhas Prabhu, Makarand Ajit Shirasgaonkar
  • Publication number: 20230026876
    Abstract: A memory controller combines information about which memory component segments are not being refreshed with the information about which rows are going to be refreshed next, to determine, for the current refresh command, the total number of rows that are going to be refreshed. Based on this total number of rows, the memory controller selects how long to wait after the refresh command before issuing a next subsequent command. When the combination of masked segments and the refresh scheme results in less than the ‘nominal’ number of rows typically refreshed in response to a single refresh command, the waiting period before the next command (e.g., non-refresh command) is issued may be reduced from the ‘nominal’ minimum time period, thereby allowing the next command to be issued earlier.
    Type: Application
    Filed: December 3, 2020
    Publication date: January 26, 2023
    Inventors: Liji GOPALAKRISHNAN, Thomas VOGELSANG, John Eric LINSTADT
  • Patent number: 11526632
    Abstract: Methods and systems for enabling secure memory transactions in a memory controller are disclosed. Responsive to determining that an incoming request is for a secure memory transaction, the incoming request is placed in a secure request container. The memory container then enters a state where re-ordering between requests for secure memory transactions placed in the secure request container and requests for non-secure memory transactions from other containers is prevented in a scheduling queue.
    Type: Grant
    Filed: August 19, 2020
    Date of Patent: December 13, 2022
    Assignee: Rambus Inc.
    Inventors: Craig E. Hampel, Liji Gopalakrishnan, John Eric Linstadt, Steven C. Woo
  • Publication number: 20220374381
    Abstract: A memory module includes memory devices and a configurable command buffer that selects between alternative command ports for controlling different groupings of the memory devices. Memory systems with memory modules incorporating such a command buffer and memory devices support point-to-point connectivity and efficient interconnect usage for different numbers of modules. The memory devices and modules can be of programmable data widths.
    Type: Application
    Filed: May 26, 2022
    Publication date: November 24, 2022
    Inventors: Liji Gopalakrishnan, Ian Shaeffer, Yi Lu
  • Publication number: 20220328078
    Abstract: The memory banks of a memory device are arranged and operated in groups and the groups are further arranged and operated as clusters of these groups. Successive accesses to banks that are within different bank group clusters may be issued at a first time interval. Successive accesses to banks that are within different bank groups within the same cluster can be issued no faster than a second time interval. And, successive accesses to banks that are within the same bank group may be issued no faster than a third time interval. The memory banks of a memory device may have multiple rows open at the same time. The rows that can be open at the same time is determined by the rows that are already open. These memory banks are also arranged and operated in groups that have three different minimum time intervals.
    Type: Application
    Filed: August 13, 2020
    Publication date: October 13, 2022
    Inventors: John Eric LINSTADT, Liji GOPALAKRISHNAN, Thomas VOGELSANG
  • Publication number: 20220291992
    Abstract: A memory system employs an addressing scheme to logically divide rows of memory cells into separate contiguous regions, one for data storage and another for error detection and correction (EDC) codes corresponding to that data. Data and corresponding EDC codes are stored in the same row of the same bank. Accessing data and corresponding EDC code in the same row of the same bank advantageously saves power and avoids bank conflicts. The addressing scheme partitions the memory without requiring the requesting processor to have an understanding of the memory partition.
    Type: Application
    Filed: April 15, 2022
    Publication date: September 15, 2022
    Inventors: Frederick A. Ware, John E. Linstadt, Liji Gopalakrishnan
  • Publication number: 20220261361
    Abstract: Memory controllers, devices, modules, systems and associated methods are disclosed. In one embodiment, an integrated circuit (IC) memory device is disclosed. The memory device includes an array of storage cells and command interface circuitry to receive an internal transfer command. In response to the internal transfer command, transfer logic reads data from a first portion of the array of storage cells, transfers the data as on-chip transfer data, and writes the on-chip transfer data to a second portion of the array of storage cells. In response to the command interface circuitry receiving an interrupt command, the transfer logic pauses the internal transfer operation, and carries out an unrelated memory access operation involving at least the first portion of the array of storage cells or the second portion of the array of storage cells.
    Type: Application
    Filed: January 4, 2022
    Publication date: August 18, 2022
    Inventors: Liji Gopalakrishnan, Frederick A. Ware, Brent S. Haukness
  • Publication number: 20220214979
    Abstract: A memory system includes a dynamic random access memory (DRAM) device, a second memory device, and a memory controller circuit. The memory controller circuit is coupled to the DRAM device by a first data channel configured to transfer first data between the memory controller circuit and the DRAM device on behalf of a host, and is also coupled to the DRAM device by a second data channel configured to transfer second data between the memory controller circuit and the DRAM device on behalf of the second memory device while the first data is being transferred across the first data bus.
    Type: Application
    Filed: January 21, 2022
    Publication date: July 7, 2022
    Inventor: Liji Gopalakrishnan
  • Patent number: 11372795
    Abstract: A memory device or module selects between alternative command ports. Memory systems with memory modules incorporating such memory devices support point-to-point connectivity and efficient interconnect usage for different numbers of modules. The memory devices and modules can be of programmable data widths. Devices on the same module can be configured select different command ports to facilitate memory threading. Modules can likewise be configured to select different command ports for the same purpose.
    Type: Grant
    Filed: July 30, 2020
    Date of Patent: June 28, 2022
    Assignee: Rambus Inc.
    Inventors: Liji Gopalakrishnan, Ian Shaeffer, Yi Lu
  • Patent number: 11372784
    Abstract: A single-ended receiver is coupled to an input-output (I/O) pin of a command and address (CA) bus. The receiver is configurable with dual-mode I/O support to operate the CA bus in a low-swing mode and a high-swing mode. The receiver is configurable to receive a first command on the I/O pin while in the high-swing mode, initiate calibration of the slave device to operate in the low-swing mode in response to the first command, switch the slave device to operate in the low-swing mode while the CA bus remains active, and to receive a second command on the I/O pin while in the low-swing mode.
    Type: Grant
    Filed: December 10, 2019
    Date of Patent: June 28, 2022
    Assignee: Rambus Inc.
    Inventors: Pravin Kumar Venkatesan, Liji Gopalakrishnan, Kashinath Ullhas Prabhu, Makarand Ajit Shirasgaonkar
  • Patent number: 11327831
    Abstract: A memory system employs an addressing scheme to logically divide rows of memory cells into separate contiguous regions, one for data storage and another for error detection and correction (EDC) codes corresponding to that data. Data and corresponding EDC codes are stored in the same row of the same bank. Accessing data and corresponding EDC code in the same row of the same bank advantageously saves power and avoids bank conflicts. The addressing scheme partitions the memory without requiring the requesting processor to have an understanding of the memory partition.
    Type: Grant
    Filed: March 27, 2020
    Date of Patent: May 10, 2022
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, John E. Linstadt, Liji Gopalakrishnan
  • Patent number: 11232047
    Abstract: A memory system includes a dynamic random access memory (DRAM) device, a second memory device, and a memory controller circuit. The memory controller circuit is coupled to the DRAM device by a first data channel configured to transfer first data between the memory controller circuit and the DRAM device on behalf of a host, and is also coupled to the DRAM device by a second data channel configured to transfer second data between the memory controller circuit and the DRAM device on behalf of the second memory device while the first data is being transferred across the first data channel.
    Type: Grant
    Filed: May 13, 2020
    Date of Patent: January 25, 2022
    Assignee: Rambus Inc.
    Inventor: Liji Gopalakrishnan
  • Patent number: 11226909
    Abstract: Memory controllers, devices, modules, systems and associated methods are disclosed. In one embodiment, an integrated circuit (IC) memory device is disclosed. The memory device includes an array of storage cells and command interface circuitry to receive an internal transfer command. In response to the internal transfer command, transfer logic reads data from a first portion of the array of storage cells, transfers the data as on-chip transfer data, and writes the on-chip transfer data to a second portion of the array of storage cells. In response to the command interface circuitry receiving an interrupt command, the transfer logic pauses the internal transfer operation, and carries out an unrelated memory access operation involving at least the first portion of the array of storage cells or the second portion of the array of storage cells.
    Type: Grant
    Filed: August 20, 2019
    Date of Patent: January 18, 2022
    Assignee: Rambus Inc.
    Inventors: Liji Gopalakrishnan, Frederick A. Ware, Brent S. Haukness
  • Publication number: 20220013161
    Abstract: A dynamic random access memory (DRAM) component (e.g., module or integrated circuit) can be configured to have multiple rows in the same bank open concurrently. The controller of the component divides the address space of the banks into segments based on row address ranges. These row address ranges do not necessarily correspond to row address ranges of the bank's subarrays (a.k.a. memory array tiles—MATs). When a command is sent to open a row, the controller marks a plurality of the segments as blocked. The controller thereby tracks address ranges in a bank where it will not open a second row unless and until the first row is closed. The memory component may store information about which, and how many, segments should be blocked in response to opening a row. This information may be read by the controller during initialization.
    Type: Application
    Filed: July 30, 2021
    Publication date: January 13, 2022
    Inventors: Thomas VOGELSANG, John Eric LINSTADT, Liji GOPALAKRISHNAN
  • Publication number: 20210358535
    Abstract: An integrated circuit includes a physical layer interface having a control timing domain and a data timing domain, and circuits that enable the control timing domain during a change in power conservation mode in response to a first event, and that enable the data timing domain in response to a second event. The control timing domain can include interface circuits coupled to a command and address path, and the data timing domain can include interface circuits coupled to a data path.
    Type: Application
    Filed: June 7, 2021
    Publication date: November 18, 2021
    Inventors: Ian Shaeffer, Lei Luo, Liji Gopalakrishnan
  • Patent number: 11114150
    Abstract: A dynamic random access memory (DRAM) component (e.g., module or integrated circuit) can be configured to have multiple rows in the same bank open concurrently. The controller of the component divides the address space of the banks into segments based on row address ranges. These row address ranges do not necessarily correspond to row address ranges of the bank's subarrays (a.k.a. memory array tiles—MATs). When a command is sent to open a row, the controller marks a plurality of the segments as blocked. The controller thereby tracks address ranges in a bank where it will not open a second row unless and until the first row is closed. The memory component may store information about which, and how many, segments should be blocked in response to opening a row. This information may be read by the controller during initialization.
    Type: Grant
    Filed: April 2, 2020
    Date of Patent: September 7, 2021
    Assignee: Rambus Inc.
    Inventors: Thomas Vogelsang, John Eric Linstadt, Liji Gopalakrishnan
  • Patent number: 11049546
    Abstract: An integrated circuit includes a physical layer interface having a control timing domain and a data timing domain, and circuits that enable the control timing domain during a change in power conservation mode in response to a first event, and that enable the data timing domain in response to a second event. The control timing domain can include interface circuits coupled to a command and address path, and the data timing domain can include interface circuits coupled to a data path.
    Type: Grant
    Filed: May 4, 2020
    Date of Patent: June 29, 2021
    Assignee: Rambus Inc.
    Inventors: Ian Shaeffer, Lei Luo, Liji Gopalakrishnan
  • Publication number: 20210064788
    Abstract: Methods and systems for enabling secure memory transactions in a memory controller are disclosed. Responsive to determining that an incoming request is for a secure memory transaction, the incoming request is placed in a secure request container. The memory container then enters a state where re-ordering between requests for secure memory transactions placed in the secure request container and requests for non-secure memory transactions from other containers is prevented in a scheduling queue.
    Type: Application
    Filed: August 19, 2020
    Publication date: March 4, 2021
    Inventors: Craig E. Hampel, Liji Gopalakrishnan, John Eric Linstadt, Steven C. Woo