Patents by Inventor Sampath Ratnam

Sampath Ratnam 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: 11966616
    Abstract: A current value for a reference voltage for a block family is determined. An amount of voltage shift for a memory page of the block family is determined based on the current value for the reference voltage and a prior value for the reference voltage. The block family is associated with a first voltage bin or a second voltage bin based on the determined amount of voltage shift. The first voltage bin is associated with a first voltage offset and the second voltage bin is associated with a second voltage offset.
    Type: Grant
    Filed: February 27, 2023
    Date of Patent: April 23, 2024
    Assignee: Micron Technology, Inc.
    Inventors: Kishore Kumar Muchherla, Devin M. Batutis, Xiangang Luo, Mustafa N. Kaynak, Peter Feeley, Sivagnanam Parthasarathy, Sampath Ratnam, Shane Nowell
  • Patent number: 11934266
    Abstract: Systems and methods are disclosed including a memory device and a processing device operatively coupled to the memory device. The processing device can perform operations comprising selecting a source set of memory cells of the memory device, wherein the source set of memory cells are configured to store a first number of bits per memory cell; performing a data integrity check on the source set of memory cells to obtain a data integrity metric value; determining whether the data integrity metric value satisfies a threshold criterion; and responsive to determining that the data integrity metric value fails to satisfy the threshold criterion, causing the memory device to copy data from the source set of memory cells to a destination set of memory cells of the memory device, wherein the destination set of memory cells are configured to store a second number of bits per memory cell.
    Type: Grant
    Filed: July 7, 2022
    Date of Patent: March 19, 2024
    Assignee: Micron Technology, Inc.
    Inventors: Vamsi Pavan Rayaprolu, Mustafa N. Kaynak, Sivagnanam Parthasarathy, Patrick Khayat, Sampath Ratnam, Kishore Kumar Muchherla, Jiangang Wu, James Fitzpatrick
  • Publication number: 20240069788
    Abstract: In some implementations, a controller of a memory device may obtain a first metric associated with a memory of the memory device using a first memory read configuration. The controller may apply a function to the first metric to obtain a second memory read configuration. The controller may obtain a second metric associated with the memory using the second memory read configuration. The controller may filter the first metric and the second metric to obtain a first filtered metric and a second filtered metric. The controller may provide the first filtered metric and the second filtered metric to a memory management process executing on the controller. The controller may perform an action based on an output of the memory management process, wherein the output is based on the first filtered metric and the second filtered metric.
    Type: Application
    Filed: August 31, 2022
    Publication date: February 29, 2024
    Inventors: Dung Viet NGUYEN, Shantilal Rayshi DORU, Jun WAN, Sampath RATNAM
  • Patent number: 11887651
    Abstract: Devices and techniques for temperature informed memory refresh are described herein. A temperature counter can be updated in response to a memory device write performed under an extreme temperature. Here, the write is performed on a memory device element in the memory device. The memory device element can be sorted above other memory device elements in the memory device based on the temperature counter. Once sorted to the top of these memory device elements, a refresh can be performed the memory device element.
    Type: Grant
    Filed: May 16, 2022
    Date of Patent: January 30, 2024
    Assignee: Micron Technology, Inc.
    Inventors: Gianni Stephen Alsasua, Harish Reddy Singidi, Kishore Kumar Muchherla, Sampath Ratnam, Ashutosh Malshe, Vamsi Pavan Rayaprolu, Renato Padilla, Jr.
  • Publication number: 20230393938
    Abstract: Systems and methods are disclosed including a memory device and a processing device operatively coupled to the memory device. The processing device can perform operations comprising selecting a source set of memory cells of the memory device, wherein the source set of memory cells are configured to store a first number of bits per memory cell; performing a data integrity check on the source set of memory cells to obtain a data integrity metric value; determining whether the data integrity metric value satisfies a threshold criterion; and responsive to determining that the data integrity metric value fails to satisfy the threshold criterion, causing the memory device to copy data from the source set of memory cells to a destination set of memory cells of the memory device, wherein the destination set of memory cells are configured to store a second number of bits per memory cell.
    Type: Application
    Filed: July 7, 2022
    Publication date: December 7, 2023
    Inventors: Vamsi Pavan Rayaprolu, Mustafa N. Kaynak, Sivagnanam Parthasarathy, Patrick Khayat, Sampath Ratnam, Kishore Kumar Muchherla, Jiangang Wu, James Fitzpatrick
  • Patent number: 11823748
    Abstract: A voltage shift for memory cells of a block family at a memory device is measured. The block family is associated with a first voltage offset. An adjusted amount of voltage shift is determined for the memory cells based on the measured voltage shift and a temporary voltage shift offset associated with a difference between a current temperature and a prior temperature for the memory device. The block family is associated with a second voltage offset in view of the adjusted voltage shift.
    Type: Grant
    Filed: August 18, 2022
    Date of Patent: November 21, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Kishore Kumar Muchherla, Karl Schuh, Mustafa N Kaynak, Xiangang Luo, Shane Nowell, Devin Batutis, Sivagnanam Parthasarathy, Sampath Ratnam, Jiangang Wu, Peter Feeley
  • Patent number: 11709633
    Abstract: Systems and methods are disclosed, comprising a memory device comprising multiple groups of memory cells, the groups comprising a first group of memory cells and a second group of memory cells configured to store information at a same bit capacity per memory cell, and a processing device operably coupled to the memory device, the processing device configured to adjust a scan event threshold for one of the first or second groups of memory cells to a threshold less than a target scan event threshold for the first and second groups of memory cells to distribute scan events in time on the memory device.
    Type: Grant
    Filed: March 2, 2022
    Date of Patent: July 25, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Gianni Stephen Alsasua, Harish Reddy Singidi, Peter Sean Feeley, Ashutosh Malshe, Renato Padilla, Jr., Kishore Kumar Muchherla, Sampath Ratnam
  • Publication number: 20230205447
    Abstract: A current value for a reference voltage for a block family is determined. An amount of voltage shift for a memory page of the block family is determined based on the current value for the reference voltage and a prior value for the reference voltage. The block family is associated with a first voltage bin or a second voltage bin based on the determined amount of voltage shift. The first voltage bin is associated with a first voltage offset and the second voltage bin is associated with a second voltage offset.
    Type: Application
    Filed: February 27, 2023
    Publication date: June 29, 2023
    Inventors: Kishore Kumar Muchherla, Devin M. Batutis, Xiangang Luo, Mustafa N. Kaynak, Peter Feeley, Sivagnanam Parthasarathy, Sampath Ratnam, Shane Nowell
  • Patent number: 11670381
    Abstract: Devices and techniques for read voltage calibration of a flash-based storage system based on host IO operations are disclosed. In an example, a memory device includes a NAND memory array having groups of multiple blocks of memory cells, and a memory controller to optimize voltage calibration for reads of the memory array. In an example, the optimization technique includes monitoring read operations occurring to a respective block, identifying a condition to trigger a read level calibration based on the read operations, and performing the read level calibration for the respective block or a memory component that includes the respective block. In a further example, the calibration is performed based on a threshold voltage to read the respective block, which may be considered when the threshold voltage to read the respective block is evaluated within a sampling operation performed by the read level calibration.
    Type: Grant
    Filed: May 6, 2021
    Date of Patent: June 6, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Ashutosh Malshe, Kishore Kumar Muchherla, Harish Reddy Singidi, Peter Sean Feeley, Sampath Ratnam, Kulachet Tanpairoj, Ting Luo
  • Patent number: 11620074
    Abstract: A current memory access voltage distribution is measured for a memory page of a block family associated with a first voltage bin of a plurality of voltage bins at a memory device. The first voltage bin is associated with a first voltage offset. A current value for a reference voltage is determined based on the current memory access voltage distribution measured for the memory page. An amount of voltage shift for the memory page is determined based on the current value for the reference voltage a prior value for the reference voltage. The prior value for the reference voltage is associated with a prior memory access voltage distribution for the memory page. In response to a determination that the amount of voltage shift satisfies a voltage shift criterion, the block family is associated with a second voltage bin of the plurality of voltage bins. The second voltage bin is associated with a second voltage offset.
    Type: Grant
    Filed: March 16, 2021
    Date of Patent: April 4, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Kishore Kumar Muchherla, Devin M. Batutis, Xiangang Luo, Mustafa N. Kaynak, Peter Feeley, Sivagnanam Parthasarathy, Sampath Ratnam, Shane Nowell
  • Patent number: 11610632
    Abstract: Devices and techniques for NAND temperature data management are disclosed herein. A command to write data to a NAND component in the NAND device is received at a NAND controller of the NAND device. A temperature corresponding to the NAND component is obtained in response to receiving the command. The command is then executed to write data to the NAND component and to write a representation of the temperature. The data is written to a user portion and the representation of the temperature is written to a management portion that is accessible only to the controller and segregated from the user portion.
    Type: Grant
    Filed: May 26, 2021
    Date of Patent: March 21, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Kishore Kumar Muchherla, Sampath Ratnam, Preston Allen Thomson, Harish Reddy Singidi, Jung Sheng Hoei, Peter Sean Feeley, Jianmin Huang
  • Patent number: 11544008
    Abstract: A memory device may receive a read request describing a logical address at the memory device. The memory device may obtain a table entry associated with the logical address. The table entry comprises a physical address corresponding to the logical address and a write temperature data indicating a write temperature for the logical address. The memory device may determine a corrected threshold voltage for reading the physical address based at least in part on the write temperature data and read the physical address using the corrected threshold voltage.
    Type: Grant
    Filed: April 16, 2021
    Date of Patent: January 3, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Gianni Stephen Alsasua, Karl D. Schuh, Ashutosh Malshe, Kishore Kumar Muchherla, Vamsi Pavan Rayaprolu, Sampath Ratnam, Harish Reddy Singidi, Renato Padilla, Jr.
  • Publication number: 20220392547
    Abstract: A voltage shift for memory cells of a block family at a memory device is measured. The block family is associated with a first voltage offset. An adjusted amount of voltage shift is determined for the memory cells based on the measured voltage shift and a temporary voltage shift offset associated with a difference between a current temperature and a prior temperature for the memory device. The block family is associated with a second voltage offset in view of the adjusted voltage shift.
    Type: Application
    Filed: August 18, 2022
    Publication date: December 8, 2022
    Inventors: Kishore Kumar Muchherla, Karl Schuh, Mustafa N. Kaynak, Xiangang Luo, Shane Nowell, Devin Batutis, Sivagnanam Parthasarathy, Sampath Ratnam, Jiangang Wu, Peter Feeley
  • Patent number: 11456037
    Abstract: Disclosed in some examples, are methods, systems, and machine readable mediums which compensate for read-disturb effects by shifting the read voltages used to read the value in a NAND cell based upon a read counter. For example, the NAND memory device may have a read counter that corresponds to a group of NAND cells (e.g., a page, a block, a superblock). Anytime a NAND cell in the group is read, the read counter may be incremented. The read voltage, Vread, may be adjusted based on the read counter to account for the read disturb voltage.
    Type: Grant
    Filed: May 12, 2021
    Date of Patent: September 27, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Harish Singidi, Kishore Kumar Muchherla, Gianni Stephen Alsasua, Ashutosh Malshe, Sampath Ratnam, Gary F. Besinga, Michael G. Miller
  • Publication number: 20220300186
    Abstract: A current memory access voltage distribution is measured for a memory page of a block family associated with a first voltage bin of a plurality of voltage bins at a memory device. The first voltage bin is associated with a first voltage offset. A current value for a reference voltage is determined based on the current memory access voltage distribution measured for the memory page. An amount of voltage shift for the memory page is determined based on the current value for the reference voltage a prior value for the reference voltage. The prior value for the reference voltage is associated with a prior memory access voltage distribution for the memory page. In response to a determination that the amount of voltage shift satisfies a voltage shift criterion, the block family is associated with a second voltage bin of the plurality of voltage bins. The second voltage bin is associated with a second voltage offset.
    Type: Application
    Filed: March 16, 2021
    Publication date: September 22, 2022
    Inventors: Kishore Kumar Muchherla, Devin M. Batutis, Xiangang Luo, Mustafa N. Kaynak, Peter Feeley, Sivagnanam Parthasarathy, Sampath Ratnam, Shane Nowell
  • Patent number: 11437108
    Abstract: A difference between a current temperature and a prior temperature of a memory device is determined. In response to a determination that the difference between the current temperature and the prior temperature of the memory device satisfies a temperature criterion, an amount of voltage shift is measured for a set of memory cells of a block family associated with a first voltage bin of a set of voltage bins at the memory device. The first voltage bin is associated with a first voltage offset. An adjusted amount of voltage shift is determined for the set of memory cells based on the determined amount of voltage shift and a temporary voltage shift offset associated with the difference between the current temperature and the prior temperature for the memory device. In response to a determination that the adjusted amount of voltage shift satisfies a voltage shift criterion, the block family is associated with a second voltage bin of the set of voltage bins.
    Type: Grant
    Filed: April 14, 2021
    Date of Patent: September 6, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Kishore Kumar Muchherla, Karl Schuh, Mustafa N Kaynak, Xiangang Luo, Shane Nowell, Devin Batutis, Sivagnanam Parthasarathy, Sampath Ratnam, Jiangang Wu, Peter Feeley
  • Patent number: 11436078
    Abstract: Disclosed in some examples are techniques for handling parity data of a non-volatile memory device with limited cache memory. In certain examples, user data can be programmed into the non-volatile memory of the non-volatile memory device in data stripes, and parity information can be calculated for each individual data stripe within a limited capacity cache of the non-volatile memory device. The individual parity information can be swapped between a swap block of the non-volatile memory and the limited capacity cache as additional data stripes are programmed.
    Type: Grant
    Filed: April 12, 2021
    Date of Patent: September 6, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Harish Reddy Singidi, Xiangang Luo, Jianmin Huang, Kishore Kumar Muchherla, Ashutosh Malshe, Vamsi Pavan Rayaprolu, Sampath Ratnam
  • Publication number: 20220277787
    Abstract: Devices and techniques for temperature informed memory refresh are described herein. A temperature counter can be updated in response to a memory device write performed under an extreme temperature. Here, the write is performed on a memory device element in the memory device. The memory device element can be sorted above other memory device elements in the memory device based on the temperature counter. Once sorted to the top of these memory device elements, a refresh can be performed the memory device element.
    Type: Application
    Filed: May 16, 2022
    Publication date: September 1, 2022
    Inventors: Gianni Stephen Alsasua, Harish Reddy Singidi, Kishore Kumar Muchherla, Sampath Ratnam, Ashutosh Malshe, Vamsi Pavan Rayaprolu, Renato Padilla, JR.
  • Publication number: 20220188040
    Abstract: Systems and methods are disclosed, comprising a memory device comprising multiple groups of memory cells, the groups comprising a first group of memory cells and a second group of memory cells configured to store information at a same bit capacity per memory cell, and a processing device operably coupled to the memory device, the processing device configured to adjust a scan event threshold for one of the first or second groups of memory cells to a threshold less than a target scan event threshold for the first and second groups of memory cells to distribute scan events in time on the memory device.
    Type: Application
    Filed: March 2, 2022
    Publication date: June 16, 2022
    Inventors: Gianni Stephen Alsasua, Harish Reddy Singidi, Peter Sean Feeley, Ashutosh Malshe, Renato Padilla, JR., Kishore Kumar Muchherla, Sampath Ratnam
  • Publication number: 20220171713
    Abstract: At least one source physical memory block stored in a memory device is identified. The source physical memory block comprises at least one logical unit. A determination is made as to whether an age characteristic of the logical unit satisfies a threshold criterion. A storage classification is determined for the logical unit based on whether the age characteristic of the logical unit satisfies the threshold criterion. The classification comprises a hot data classification or a cold data classification. A target physical memory block is identified based on the storage classification determined for the logical unit, and the logical unit is stored in the identified target physical memory block.
    Type: Application
    Filed: August 11, 2021
    Publication date: June 2, 2022
    Inventors: Ashutosh Malshe, Sampath Ratnam, Kishore Kumar Muchherla, Peter Feeley