Patents by Inventor Sundararajan Sankaranarayanan

Sundararajan Sankaranarayanan 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: 20240134571
    Abstract: A system can include a memory device and a processing device, operatively coupled with the memory device, to perform operations including reading a first copy of data stored in a first set of memory cells comprising a first memory cell, determining whether a threshold voltage of the first memory cell is within a first range of threshold voltages, responsive to determining that the threshold voltage of the first memory cell is within the first range of threshold voltages, reading a second copy of the data stored in a second set of memory cells comprising a second memory cell, determining whether a threshold voltage of the second memory cell is within a second range of threshold voltages, and responsive to determining that the threshold voltage of the second memory cell is outside the second range, using the second copy of the data.
    Type: Application
    Filed: December 29, 2023
    Publication date: April 25, 2024
    Inventors: Jeffrey S. McNeil, Kishore Kumar Muchherla, Sivagnanam Parthasarathy, Patrick R. Khayat, Sundararajan Sankaranarayanan, Jeremy Binfet, Akira Goda
  • Patent number: 11947452
    Abstract: A subset of blocks from a set of blocks of a memory device are identified based on a valid data count constraint. A first block from the subset of blocks is selected based on a valid data count of the first block. A second block from the subset of blocks is selected based on a data temperature of the second block. A comparison of the first block and the second block is performed in accordance with one or more comparison criterion. The first block or the second block is selected as a garbage collection source block based on the comparison. Garbage collection is performed at the garbage collection source block.
    Type: Grant
    Filed: June 1, 2022
    Date of Patent: April 2, 2024
    Assignee: Micron Technology, Inc.
    Inventors: Xiangyu Tang, David Ebsen, Ying Huang, Sundararajan Sankaranarayanan
  • Patent number: 11922993
    Abstract: A device includes an array of memory cells with a first word line coupled to at least a subset of the array of memory cells and control logic coupled to the first word line. The control logic to detect, within a queue, a first read command to read first data from a first page of the subset and a second read command to read second data from a second page of the subset. The control logic is further to cause a voltage applied to the first word line to move to a target value. The control logic is further to cause a page buffer to sense the first data from a first bit line coupled to the first page and to sense the second data from a second bit line coupled to the second page. The control logic is further to cause the first word line to be discharged.
    Type: Grant
    Filed: January 11, 2023
    Date of Patent: March 5, 2024
    Assignee: Micron Technology, Inc.
    Inventors: Koichi Kawai, Sundararajan Sankaranarayanan, Eric Nien-Heng Lee, Akira Goda
  • Publication number: 20240069738
    Abstract: A memory sub-system includes a memory sub-system controller comprising a plurality of controller channels, one or more memory devices, each of which comprises a respective plurality of memory dies, and a channel switch circuit coupled between the plurality of the controller channels and a plurality of memory channels of the one or more memory devices, where each memory channel corresponds to a respective one of the plurality of memory dies of one of the memory devices, the channel switch circuit comprising command processing logic configured to: receive, from the memory sub-system controller, a plurality of channel mappings, each of which identifies a particular one of the controller channels and a particular one of the memory channels, and route data from each controller channel to a respective one of the memory channels that is associated with the controller channel by a respective one of the channel mappings.
    Type: Application
    Filed: August 29, 2022
    Publication date: February 29, 2024
    Inventors: Chulbum Kim, Sundararajan Sankaranarayanan, Xiangyu Tang, Dustin J. Carter
  • Publication number: 20240069721
    Abstract: Memory with switchable channels is disclosed herein. In one embodiment, a system comprises a controller, a plurality of memory dies, and a switch matrix. The switch matrix is coupled to the controller via two or more controller-side channels, and to the plurality of memory dies via a set of memory-side channels. The switch matrix is configured to selectively couple each controller-side channel of the two or more controller-side channels to each memory-side channel of the set of memory-side channels to provide dynamically configurable connections between the controller and one or more memory dies of the plurality of memory dies.
    Type: Application
    Filed: August 31, 2022
    Publication date: February 29, 2024
    Inventors: Sundararajan Sankaranarayanan, Chulbum Kim, Xiangyu Tang
  • Patent number: 11861233
    Abstract: A system can include a memory device and a processing device, operatively coupled with the memory device, to perform operations including receiving data to be stored on the memory device, storing a first copy of the data in a first set of memory cells of the memory device, and storing a second copy of the data in a second set of memory cells of the memory device. The operations can also include reading the first copy of the data and determining whether a threshold voltage of a cell in the first set of memory cells is within an overlapping range of voltage distributions, and reading the second copy of the data and determining whether the threshold voltage of a cell in the second set of memory cells is within an overlapping range of voltage distributions. They can also include using the second copy of the data.
    Type: Grant
    Filed: March 10, 2022
    Date of Patent: January 2, 2024
    Assignee: Micron Technology, Inc.
    Inventors: Jeffrey S. McNeil, Kishore Kumar Muchherla, Sivagnanam Parthasarathy, Patrick R. Khayat, Sundararajan Sankaranarayanan, Jeremy Binfet, Akira Goda
  • Publication number: 20230393976
    Abstract: A subset of blocks from a set of blocks of a memory device are identified based on a valid data count constraint. A first block from the subset of blocks is selected based on a valid data count of the first block. A second block from the subset of blocks is selected based on a data temperature of the second block. A comparison of the first block and the second block is performed in accordance with one or more comparison criterion. The first block or the second block is selected as a garbage collection source block based on the comparison. Garbage collection is performed at the garbage collection source block.
    Type: Application
    Filed: June 1, 2022
    Publication date: December 7, 2023
    Inventors: Xiangyu Tang, David Ebsen, Ying Huang, Sundararajan Sankaranarayanan
  • Publication number: 20230214139
    Abstract: A second read command to read second data from an array of memory cells is detected. An initial voltage to be applied to at least one wordline coupled to at least a subset of the array of memory cells is caused prior to releasing a first data associated with a first read command stored in a page buffer. The initial voltage to increase to a target value is caused. The page buffer to sense the second data from a bitline coupled to a page of the subset of the array of memory cells is caused. The sensed second data out of the bitline into the page buffer is read responsive to determining that the first data has been released from the page buffer.
    Type: Application
    Filed: July 6, 2022
    Publication date: July 6, 2023
    Inventors: Sundararajan Sankaranarayanan, Eric N. Lee
  • Patent number: 11687237
    Abstract: A local media controller of a first memory device receives a first number of cycles broadcasted by a second memory device via a bus connecting the first memory device and the second memory device. The local media controller initializes a counter associated with the first memory device. Responsive to determining that the value of the counter matches the first number of cycles, the local media controller transmits a status of the first memory device via the bus. Furthermore, responsive to determining that the status is ready, the local media controller sends, to a memory sub-system controller managing the first memory device, a status of a memory region of the first memory device.
    Type: Grant
    Filed: August 4, 2021
    Date of Patent: June 27, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Chulbum Kim, Sundararajan Sankaranarayanan
  • Publication number: 20230195385
    Abstract: A system can include a memory device and a processing device, operatively coupled with the memory device, to perform operations including receiving data to be stored on the memory device, storing a first copy of the data in a first set of memory cells of the memory device, and storing a second copy of the data in a second set of memory cells of the memory device. The operations can also include reading the first copy of the data and determining whether a threshold voltage of a cell in the first set of memory cells is within an overlapping range of voltage distributions, and reading the second copy of the data and determining whether the threshold voltage of a cell in the second set of memory cells is within an overlapping range of voltage distributions. They can also include using the second copy of the data.
    Type: Application
    Filed: March 10, 2022
    Publication date: June 22, 2023
    Inventors: Jeffrey S. McNeil, Kishore Kumar Muchherla, Sivagnanam Parthasarathy, Patrick Khayat, Sundararajan Sankaranarayanan, Jeremy Binfet, Akira Goda
  • Publication number: 20230148018
    Abstract: A device includes an array of memory cells with a first word line coupled to at least a subset of the array of memory cells and control logic coupled to the first word line. The control logic to detect, within a queue, a first read command to read first data from a first page of the subset and a second read command to read second data from a second page of the subset. The control logic is further to cause a voltage applied to the first word line to move to a target value. The control logic is further to cause a page buffer to sense the first data from a first bit line coupled to the first page and to sense the second data from a second bit line coupled to the second page. The control logic is further to cause the first word line to be discharged.
    Type: Application
    Filed: January 11, 2023
    Publication date: May 11, 2023
    Inventors: Koichi Kawai, Sundararajan Sankaranarayanan, Eric Nien-Heng Lee, Akira Goda
  • Publication number: 20230045463
    Abstract: A local media controller of a first memory device receives a first number of cycles broadcasted by a second memory device via a bus connecting the first memory device and the second memory device. The local media controller initializes a counter associated with the first memory device. Responsive to determining that the value of the counter matches the first number of cycles, the local media controller transmits a status of the first memory device via the bus. Furthermore, responsive to determining that the status is ready, the local media controller sends, to a memory sub-system controller managing the first memory device, a status of a memory region of the first memory device.
    Type: Application
    Filed: August 4, 2021
    Publication date: February 9, 2023
    Inventors: Chulbum Kim, Sundararajan Sankaranarayanan
  • Patent number: 11568921
    Abstract: A device includes an array of memory cells having a word line coupled to at least a subset of the array, a queue, and control logic. The control logic: detects a first read command to read first data from a first page of the subset; accesses a second read command in the queue, the second read command to read second data from a second page of the subset; causes a voltage applied to the word line to ramp up to an initial value; causes the voltage to move to a target value; directs a page buffer to sense the first data from a first bit line coupled to the first page of the subset; directs the page buffer to sense the second data from a second bit line coupled to the second page of the subset; and causes the word line to be discharged.
    Type: Grant
    Filed: May 12, 2021
    Date of Patent: January 31, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Koichi Kawai, Sundararajan Sankaranarayanan, Eric Nien-Heng Lee, Akira Goda
  • Publication number: 20220391321
    Abstract: A memory device includes a first memory array, a second memory array, and a page cache circuit coupled to the first memory array and the second memory array. The page cache circuit includes at least one set of concurrent resources and at least one shared resource, wherein the at least one set of concurrent resources are asynchronously and concurrently accessible by the first memory array and the second memory array, and wherein the at least one shared resource is accessible in a time-multiplexed fashion by the first memory array and the second memory array.
    Type: Application
    Filed: December 10, 2021
    Publication date: December 8, 2022
    Inventors: Sundararajan Sankaranarayanan, Eric N. Lee
  • Publication number: 20220366961
    Abstract: A device includes an array of memory cells having a word line coupled to at least a subset of the array, a queue, and control logic. The control logic: detects a first read command to read first data from a first page of the subset; accesses a second read command in the queue, the second read command to read second data from a second page of the subset; causes a voltage applied to the word line to ramp up to an initial value; causes the voltage to move to a target value; directs a page buffer to sense the first data from a first bit line coupled to the first page of the subset; directs the page buffer to sense the second data from a second bit line coupled to the second page of the subset; and causes the word line to be discharged.
    Type: Application
    Filed: May 12, 2021
    Publication date: November 17, 2022
    Inventors: Koichi Kawai, Sundararajan Sankaranarayanan, Eric Nien-Heng Lee, Akira Goda
  • Patent number: 11500547
    Abstract: Systems and methods presented herein provide for mitigating errors in a storage device. In one embodiment, a storage system includes a storage device comprising a plurality of storage areas operable to store data, and a controller operable to evaluate operating conditions of the storage device, to perform a background scan on a first of the storage areas to characterize a read retention of the first storage area, and to adjust a read signal of the first storage area based on the characterized read retention and the operating conditions of the storage device.
    Type: Grant
    Filed: February 5, 2021
    Date of Patent: November 15, 2022
    Assignee: Seagate Technology LLC
    Inventors: Ludovic Danjean, Abdelhakim Alhussien, Sundararajan Sankaranarayanan, Erich Franz Haratsch
  • Patent number: 11042316
    Abstract: A device may include a SSD having multiple storage units and a deduplication control circuit configured to determine whether selected data content to be stored is a duplicate of previous data content already in a first buffer of data buffered to be stored in a set of storage units. The deduplication circuit may be further configured to, based on a determination that the selected data content is a duplicate of first previous data content already buffered in the first buffer, instead of buffering another copy of the selected data content, buffer a first header including a first pointer that associates the first header with the first previous data content already buffered in the first buffer. The deduplication circuit may also be configured to reorder the first buffer such that individual data contents in the first buffer are grouped near headers associated with the individual data contents.
    Type: Grant
    Filed: September 9, 2019
    Date of Patent: June 22, 2021
    Assignee: seagate technology llc
    Inventors: Hongmei Xie, AbdelHakim Alhussien, Sundararajan Sankaranarayanan, Alex Tang, Leonid Baryudin, Erich Franz Haratsch
  • Publication number: 20210181954
    Abstract: Systems and methods presented herein provide for mitigating errors in a storage device. In one embodiment, a storage system includes a storage device comprising a plurality of storage areas operable to store data, and a controller operable to evaluate operating conditions of the storage device, to perform a background scan on a first of the storage areas to characterize a read retention of the first storage area, and to adjust a read signal of the first storage area based on the characterized read retention and the operating conditions of the storage device.
    Type: Application
    Filed: February 5, 2021
    Publication date: June 17, 2021
    Inventors: Ludovic Danjean, Abdelhakim Alhussien, Sundararajan Sankaranarayanan, Erich Franz Haratsch
  • Patent number: 11024396
    Abstract: Channel information and channel conditions determined by an Offline Tracking process are used to determine whether or not an adjustment to the read reference voltage can be avoided altogether without detrimentally affecting performance, or, alternatively, to determine a precision with which a read reference voltage adjustment should be made. If it is determined based on the channel conditions that a read reference voltage adjustment can be avoided altogether, read performance is improved by reducing the probability that a read reference voltage adjustment needs to be made during normal read operations. If it is determined based on the channel conditions that a read reference voltage adjustment needs to be made with a particular precision, the read reference voltage is so adjusted. This latter approach is advantageous in that relatively fewer adjustments will be made during normal read operations.
    Type: Grant
    Filed: July 22, 2019
    Date of Patent: June 1, 2021
    Assignee: seagate technology llc
    Inventors: Zhengang Chen, Erich F. Haratsch, Sundararajan Sankaranarayanan
  • Patent number: 10942655
    Abstract: Systems and methods presented herein provide for mitigating errors in a storage device. In one embodiment, a storage system includes a storage device comprising a plurality of storage areas operable to store data, and a controller operable to evaluate operating conditions of the storage device, to perform a background scan on a first of the storage areas to characterize a read retention of the first storage area, and to adjust a read signal of the first storage area based on the characterized read retention and the operating conditions of the storage device.
    Type: Grant
    Filed: July 9, 2019
    Date of Patent: March 9, 2021
    Assignee: Seagate Technology LLC
    Inventors: Ludovic Danjean, Abdelhakim Alhussien, Sundararajan Sankaranarayanan, Erich Franz Haratsch