Patents by Inventor Sivagnanam Parthasarathy

Sivagnanam Parthasarathy 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: 20240154625
    Abstract: A bit flipping decoder receives a codeword stored in a memory device. The bit flipping decoder determines a plurality of energy function values for the codeword and a least reliable of the energy function values for the codeword. In response to the bit flipping decoder determining the least reliable energy function value fails to satisfy a bit flipping criterion of a current iteration, the bit flipping decoder increments an iteration count. The incrementing of the iteration count bypasses a comparison of the plurality of energy function values with the bit flipping criterion of the current iteration.
    Type: Application
    Filed: November 6, 2023
    Publication date: May 9, 2024
    Inventors: Mustafa N. Kaynak, Eyal En Gad, Sivagnanam Parthasarathy
  • 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: 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
  • Publication number: 20240103749
    Abstract: At least one data of a set of data stored at a memory cell of a memory component is determined to be associated with an unsuccessful error correction operation. A determination is made as to whether a programming operation associated with the set of data stored at the memory cell has completed. The at least one data of the set of data stored at the memory cell that is associated with the unsuccessful error correction operation is recovered in response to determining that the programming operation has completed. Another memory cell of the memory component is identified in response to recovering the at least one data of the set of data stored at the memory cell that is associated with the unsuccessful error correction operation. The set of data including the recovered at least one data is provided to the other memory cell of the memory component.
    Type: Application
    Filed: December 1, 2023
    Publication date: March 28, 2024
    Inventors: Sampath K. Ratnam, Vamsi Pavan Rayaprolu, Mustafa N. Kaynak, Sivagnanam Parthasarathy, Kishore Kumar Muchherla, Shane Nowell, Peter Feeley, Qisong Lin
  • 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
  • Patent number: 11934824
    Abstract: Methods, apparatuses, and systems for in- or near-memory processing are described. Strings of bits (e.g., vectors) may be fetched and processed in logic of a memory device without involving a separate processing unit. Operations (e.g., arithmetic operations) may be performed on numbers stored in a bit-parallel way during a single sequence of clock cycles. Arithmetic may thus be performed in a single pass as numbers are bits of two or more strings of bits are fetched and without intermediate storage of the numbers. Vectors may be fetched (e.g., identified, transmitted, received) from one or more bit lines. Registers of a memory array may be used to write (e.g., store or temporarily store) results or ancillary bits (e.g., carry bits or carry flags) that facilitate arithmetic operations. Circuitry near, adjacent, or under the memory array may employ XOR or AND (or other) logic to fetch, organize, or operate on the data.
    Type: Grant
    Filed: April 6, 2020
    Date of Patent: March 19, 2024
    Assignee: Micron Technology, Inc.
    Inventors: Dmitri Yudanov, Sean S. Eilert, Sivagnanam Parthasarathy, Shivasankar Gunasekaran, Ameen D. Akel
  • Publication number: 20240086282
    Abstract: Systems, methods, and apparatus related to a multi-level error correction architecture used for copying data in memory devices. In one approach, user data is stored in the first partition of a non-volatile memory. First error correction code data is generated for the user data and stored with the user data in the first partition. Second error correction code data is generated for the user data and stored outside the first partition. The second error correction code data provides an increased error correcting capability that is compatible with the error correction algorithm used with the first error correction code data. A copyback operation is used to copy the user data and the first error correction code, but not the second error correction code, to a second partition of the non-volatile memory. The second error correction code can be selectively used if there is a need to recover portions of the user data stored in the first partition.
    Type: Application
    Filed: November 16, 2023
    Publication date: March 14, 2024
    Inventors: Mustafa N. Kaynak, Kishore Kumar Muchherla, Sivagnanam Parthasarathy, James Fitzpatrick, Mark A. Helm
  • Patent number: 11928347
    Abstract: A processing device of a memory sub-system is configured to sort a plurality of blocks of the memory device; identify, based on scanning of a first block at a first location of the plurality of sorted block, a first voltage bin associated with the first block; identify, based on scanning of a second block at a second location of the plurality of sorted blocks, a second voltage bin associated with the second block; and responsive to determining that the first voltage bin matches the second voltage bin, assign the first voltage bin to each block that is located between the first location of the plurality of sorted blocks and the second location of the plurality of sorted blocks.
    Type: Grant
    Filed: February 27, 2023
    Date of Patent: March 12, 2024
    Assignee: Micron Technology, Inc.
    Inventors: Kishore Kumar Muchherla, Mustafa N Kaynak, Peter Feeley, Sampath K Ratnam, Shane Nowell, Sivagnanam Parthasarathy, Karl D Schuh, Jiangang Wu
  • Publication number: 20240079035
    Abstract: A processing device in a memory sub-system monitors a temperature associated with a block of a memory device, the block comprising a plurality of wordlines. The processing device further determines a first amount of time between when memory cells associated with a first wordline of the plurality of wordlines of the block were written and when memory cells associated with a last wordline of the plurality of wordlines of the block were written. That first amount of time is normalized according to the temperature associated with the block. The processing device further determines, based at last in part on the first amount of time and on an associated scaling factor, an estimate of when the block will reach a uniform charge loss state.
    Type: Application
    Filed: November 14, 2023
    Publication date: March 7, 2024
    Inventors: Patrick R. Khayat, Steven Michael Kientz, Sivagnanam Parthasarathy, Mustafa N. Kaynak, Vamsi Pavan Rayaprolu
  • Patent number: 11923867
    Abstract: Methods, systems, and apparatuses detect and mitigate a stall condition in an iterative decoder. A codeword is received and one or more of the plurality of bits in the codeword are flipped by a bit flipping decoder in each of a plurality of error correction iterations. In response to detecting a stall condition in the plurality of error correction iterations, a maximum stop condition is increased. The maximum stop condition is a maximum iteration count threshold or a maximum decoding time threshold. The maximum stop condition triggers a stopping of the bit flipping decoder if the codeword is not decoded when the maximum stop condition is satisfied.
    Type: Grant
    Filed: August 18, 2022
    Date of Patent: March 5, 2024
    Assignee: MICRON TECHNOLOGY, INC.
    Inventors: Sivagnanam Parthasarathy, Mustafa N. Kaynak
  • Patent number: 11923868
    Abstract: Methods, systems, and apparatuses detect and mitigate a stall condition in an iterative decoder. A codeword is received and one or more of the plurality of bits in the codeword are flipped by a bit flipping decoder in each of a plurality of error correction iterations using a first plurality of bit flipping rules. In response to detecting a stall condition in the plurality of error correction iterations, a second plurality of bit flipping rules is selected. In each of one or more subsequent error correction iterations, the bit flipping decoder flips one or more of the plurality of bits in the codeword using the second plurality of bit flipping rules. The second plurality of bit flipping rules differs from the first plurality of bit flipping rules.
    Type: Grant
    Filed: August 18, 2022
    Date of Patent: March 5, 2024
    Assignee: MICRON TECHNOLOGY, INC.
    Inventors: Mustafa N. Kaynak, Sivagnanam Parthasarathy
  • Publication number: 20240071521
    Abstract: Described are memory devices producing metadata characterizing the applied read voltage level with respect to voltage distributions. An example memory sub-system comprises: a memory device comprising a plurality of memory cells; and a controller coupled to the memory device, the controller to perform operations comprising: performing, using a read voltage level, a read strobe with respect to a subset of the plurality of memory cells; and receiving, from the memory device, one or more metadata values characterizing the read voltage level with respect to threshold voltage distributions of the subset of the plurality of memory cells, wherein the one or more metadata values reflect a conductive state of one or more bitlines connected to the subset of the plurality of memory cells.
    Type: Application
    Filed: July 31, 2023
    Publication date: February 29, 2024
    Inventors: Dung Viet Nguyen, Patrick R. Khayat, Sivagnanam Parthasarathy, Zhengang Chen, Dheeraj Srinivasan
  • Publication number: 20240070023
    Abstract: A method includes determining, by a processing device, a value of a memory endurance state metric associated with a segment of a memory device in a memory sub-system; determining a target value of a code rate based on the value of the memory endurance state metric, and adjusting the code rate of the memory device according to the target value, wherein the code rate reflects a ratio of a number of memory units designated for storing host-originated data to a total number of memory units designated for storing the host-originated data and error correction metadata.
    Type: Application
    Filed: August 29, 2022
    Publication date: February 29, 2024
    Inventors: Kishore Kumar Muchherla, Niccolo' Righetti, Sivagnanam Parthasarathy, Mustafa N. Kaynak, Mark A. Helm, James Fitzpatrick, Ugo Russo
  • Publication number: 20240061589
    Abstract: A method includes determining a logical saturation of a memory device in a memory sub-system and adjusting a code rate of the memory device based on the logical saturation, wherein the code rate represents a ratio of user data to a combination of the user data and error correction data.
    Type: Application
    Filed: August 17, 2022
    Publication date: February 22, 2024
    Inventors: Kishore Kumar Muchherla, Mustafa N. Kaynak, Jonathan S. Parry, Sivagnanam Parthasarathy, Akira Goda
  • Publication number: 20240063820
    Abstract: Methods, systems, and apparatuses detect and mitigate a stall condition in an iterative decoder. A codeword is received and one or more of the plurality of bits in the codeword are flipped by a bit flipping decoder in each of a plurality of error correction iterations using a first plurality of bit flipping rules. In response to detecting a stall condition in the plurality of error correction iterations, a second plurality of bit flipping rules is selected. In each of one or more subsequent error correction iterations, the bit flipping decoder flips one or more of the plurality of bits in the codeword using the second plurality of bit flipping rules. The second plurality of bit flipping rules differs from the first plurality of bit flipping rules.
    Type: Application
    Filed: August 18, 2022
    Publication date: February 22, 2024
    Inventors: Mustafa N. Kaynak, Sivagnanam Parthasarathy
  • Publication number: 20240063819
    Abstract: Methods, systems, and apparatuses detect and mitigate a stall condition in an iterative decoder. A codeword is received and one or more of the plurality of bits in the codeword are flipped by a bit flipping decoder in each of a plurality of error correction iterations. In response to detecting a stall condition in the plurality of error correction iterations, a maximum stop condition is increased. The maximum stop condition is a maximum iteration count threshold or a maximum decoding time threshold. The maximum stop condition triggers a stopping of the bit flipping decoder if the codeword is not decoded when the maximum stop condition is satisfied.
    Type: Application
    Filed: August 18, 2022
    Publication date: February 22, 2024
    Inventors: Sivagnanam Parthasarathy, Mustafa N. Kaynak
  • Publication number: 20240063818
    Abstract: Methods, systems, and apparatuses detect and mitigate a stall condition in an iterative decoder. A codeword is received from a memory device. One or more of the plurality of bits in the codeword are flipped in each of a plurality of error correction iterations. Each bit is flipped using a first bit flipping criterion that includes comparing a first bit flipping threshold and an energy function of each bit. Responsive to the determining an iteration count threshold is satisfied and a parity violation count threshold is satisfied, one or more of the plurality of bits in the codeword are flipped using a second bit flipping criterion for one or more error correction iterations. The second bit flipping criterion differs from the first bit flipping criterion.
    Type: Application
    Filed: August 18, 2022
    Publication date: February 22, 2024
    Inventors: Mustafa N. Kaynak, Sivagnanam Parthasarathy
  • Publication number: 20240055061
    Abstract: Embodiments disclosed can include determining, for a wordline of the plurality of wordlines, a target read window budget (RWB) increase, wherein the target RWB increase corresponds to a maximum RWB increase associated with using a different PV voltage offset for each respective programming level of a memory cell. Embodiments can also include segmenting the plurality of wordlines into one or more wordline groups, wherein each wordline group comprises one or more wordlines. Embodiments can further include determining, for each wordline group, a target adjustment to a parameter of a memory access operation that is performed with respect to a memory cell associated with a wordline of the wordline group. Embodiments can include determining an aggregate RWB increase for the block in view of the target adjustment to the parameter of the memory access operation.
    Type: Application
    Filed: August 9, 2022
    Publication date: February 15, 2024
    Inventors: Mustafa N. Kaynak, Patrick R. Khayat, Sivagnanam Parthasarathy
  • Publication number: 20240055050
    Abstract: Embodiments disclosed can include determining, for a wordline of the plurality of wordlines, a respective value of a sensitivity metric that reflects a sensitivity of a threshold voltage of a memory cell associated with the wordline to a change in a threshold voltage of an adjacent memory cell. Embodiments can also include determining, for the wordline, that the respective value of the sensitivity metric satisfies a threshold criterion. Embodiments can further include responsive to determining that the respective value of the sensitivity metric satisfies the threshold criterion, associating the wordline with a first wordline group, wherein the first wordline group comprises one or more wordlines, and wherein each wordline of the one or more wordlines is associated with a respective value of the sensitivity metric that satisfies the threshold criterion. Embodiments can include performing, on a specified memory cell connected to the wordline associated with the first wordline group, a compensatory operation.
    Type: Application
    Filed: August 9, 2022
    Publication date: February 15, 2024
    Inventors: Mustafa N. Kaynak, Patrick R. Khayat, Sivagnanam Parthasarathy
  • Publication number: 20240054048
    Abstract: A system related to providing multi-layer code rates for special event protection with reduced performance penalty for memories is disclosed. Based on an impending stress event, extra error correction code data is utilized to encode user data obtained from a host. The user data and first error correction code data are written to a first block and the extra error correction code data is written to a second block. Upon stress event completion, pages having user data with the extra error correction code data are scanned. If pages of the first block are unable to satisfy reliability requirements, a touch-up process is executed on each page in the first block to reinstate the first block so that the extra error correction code data is no longer needed. The extra error correction code data is deleted from the second block and the second block is made available for user data.
    Type: Application
    Filed: August 9, 2022
    Publication date: February 15, 2024
    Inventors: Kishore Kumar Muchherla, Huai-Yuan Tseng, Mustafa N. Kaynak, Akira Goda, Sivagnanam Parthasarathy, Jonathan Scott Parry