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: 20230145358
    Abstract: A method includes receiving, by control logic of a memory device, a copyback clear command from a processing device; causing, in response to the copyback clear command, a page buffer to perform a dual-strobe read operation on first memory cells configured as single-level cells, the dual-strobe read operation including a soft strobe at a first threshold voltage and a hard strobe at a second threshold voltage that are sensed between threshold voltage distributions of the first memory cells; causing the page buffer to determine a number of one bit values within the threshold voltage distributions detected in a threshold voltage range between the first/second threshold voltages; and causing, in response to the number of one bit values not satisfying a threshold criterion, a copyback of data in the first memory cells to second memory cells configured as high-level cells without intervention from the processing device.
    Type: Application
    Filed: November 1, 2022
    Publication date: May 11, 2023
    Inventors: Jeffrey S. McNeil, Sivagnanam Parthasarathy, Kishore Kumar Muchherla, Patrick R. Khayat, Sead Zildzic, Violante Moschiano, James Fitzpatrick
  • Publication number: 20230122275
    Abstract: A method includes initiating a voltage calibration scan with respect to a block of a memory device, wherein the block is assigned to a first bin associated with a first set of read voltage offsets, and wherein the first bin is designated as a current bin, measuring a value of a data state metric for the block based on a second set of read voltage offsets associated with a second bin having an index value higher than the first bin, determining whether the value is less than a current value of the data state metric measured based on the first set of read voltage offsets, and in response to determining that the value is less than the current value, designating the second bin as the current bin.
    Type: Application
    Filed: December 19, 2022
    Publication date: April 20, 2023
    Inventors: Kishore Kumar Muchherla, Mustafa N. Kaynak, Sivagnanam Parthasarathy, Xiangang Luo, Peter Feeley, Devin M. Batutis, Jiangang Wu, Sampath K. Ratnam, Shane Nowell, Karl D. Schuh
  • Patent number: 11632132
    Abstract: A processing device in a memory system receives a request to read data from a memory device. In response to receiving the request, the processing device performs an iterative error correction process on the data, wherein at least one iteration after a first iteration in the error correction process uses a criterion that is based at least partially on a previous iteration or partial iteration, and wherein performing the iterative error correction process comprises flipping any bits in the data having an associated number of unsatisfied parity check equations that satisfies a threshold criterion associated with the previous iteration.
    Type: Grant
    Filed: September 16, 2021
    Date of Patent: April 18, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Eyal En Gad, Zhengang Chen, Sivagnanam Parthasarathy, Yoav Weinberg
  • 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
  • Publication number: 20230086696
    Abstract: A plurality of codewords are programmed to one or more memory pages of a memory sub-system. Each memory page of the memory sub-system is associated with a logical unit of a plurality of logical units of the memory sub-system and at least one of a plane of a plurality of planes of the memory sub-system or a block of a plurality of blocks of the memory sub-system. Each codeword of the plurality of codewords comprises host data and base parity bits. A plurality of additional parity bits are programmed to the one or more memory pages of the memory sub-system, wherein each additional parity bit of the plurality of additional parity bits is associated with a codeword of the plurality of standard codewords. A first set of redundancy metadata is generated corresponding to each of the additional parity bits. The first set of redundancy metadata is programmed to a memory page separate from any memory page storing the additional parity bits.
    Type: Application
    Filed: September 17, 2021
    Publication date: March 23, 2023
    Inventors: Zhengang Chen, Sivagnanam Parthasarathy
  • Patent number: 11609857
    Abstract: Exemplary methods, apparatuses, and systems include receiving a read operation directed to an aggressor location. An integrity scan of a victim location of the aggressor location is performed to determine an error value for the victim location. Data from the aggressor location is copied to a cache in response to determining the error value for the victim location satisfies a first error value threshold. The cache is a different type of memory from the aggressor location.
    Type: Grant
    Filed: December 4, 2020
    Date of Patent: March 21, 2023
    Assignee: MICRON TECHNOLOGY, INC.
    Inventors: Saeed Sharifi Tehrani, Sivagnanam Parthasarathy, Aniryudh Reddy Durgam
  • Publication number: 20230074966
    Abstract: A memory device to manage the assignment of offset voltages for read operations, and to adjust read voltages using the offset voltages. The offset voltages are dynamically adjusted by a controller during operation of the memory device in response to read errors. In one approach, a first bin of offset voltages is assigned to a first region of a storage media. The first offset voltages are used to adjust read voltages for reading a page of first memory cells in the first region. The controller determines that at least one error has occurred in reading the page. In response to determining the error, the controller determines second offset voltages that can be used to read the first memory cell without causing a read error. Based on the second offset voltages, the controller identifies third offset voltages for assigning to the first region. The third offset voltages are used for adjusting read voltages for subsequent reads of pages in the first region.
    Type: Application
    Filed: November 11, 2022
    Publication date: March 9, 2023
    Inventors: Mustafa N. Kaynak, Sivagnanam Parthasarathy, Patrick Robert Khayat
  • Publication number: 20230062445
    Abstract: Processing logic in a memory device receives a command to execute a set of read operations having read voltage levels corresponding to a programming distribution associated with the memory device. A set of memory bit counts is determined, where each memory bit count corresponds to a respective bin of a set of bins associated with the multiple read voltage levels of the set of read operations. A valley center bin having a minimum memory bit count of the set of memory bit counts is determined. The processing logic determines that the minimum memory bit count of the valley center bin satisfies a condition and an adjusted read voltage level associated with the valley center bin is identified in response to the condition being satisfied.
    Type: Application
    Filed: February 28, 2022
    Publication date: March 2, 2023
    Inventors: Eric N. Lee, Violante Moschiano, Jeffrey S. McNeil, James Fitzpatrick, Sivagnanam Parthasarathy, Kishore Kumar Muchherla, Patrick R. Khayat
  • Publication number: 20230068702
    Abstract: Control logic in a memory device receives a request to read data from a memory array of a memory device, the request comprising an indication of a segment of the memory array where the data is stored, and determines whether a write temperature associated with the data is stored in a flag byte corresponding to the segment of the memory array. Responsive to determining that the write temperature associated with the data is stored in the flag byte, the control logic determines a cross-temperature for the data based on the write temperature and a read temperature at a time when the request to read the data is received, determines a program/erase cycle count associated with the segment of the memory array, and determines, based on the cross-temperature and the program/erase cycle count, whether to perform a corrective action to calibrate a read voltage level to be applied to the memory array to read the data from the segment.
    Type: Application
    Filed: February 2, 2022
    Publication date: March 2, 2023
    Inventors: Kishore Kumar Muchherla, Violante Moschiano, Akira Goda, Jeffrey S. McNeil, Jung Sheng Hoei, Sivagnanam Parthasarathy, James Fitzpatrick, Patrick R. Khayat
  • Patent number: 11593005
    Abstract: A processing device of a memory sub-system is configured to sort a plurality of blocks of the memory device; divide the sorted plurality of blocks into a plurality of block segments; scan a first block at a first boundary of a first block segment of the plurality of block segments; scan a second block at a second boundary of the first block segment; identify, based on a scanning result of the first block, a first voltage bin associated with the first block; identify, based on a second scanning result of the second block, 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 of a subset of the plurality of blocks assigned to the first block segment.
    Type: Grant
    Filed: March 31, 2021
    Date of Patent: February 28, 2023
    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
  • Patent number: 11587638
    Abstract: A memory sub-system configured to generate or update a model for reading memory cells in a memory device. For example, in response to a processing device of a memory sub-system transmitting to a memory device read commands that are configured to instruct the memory device to retrieve data from a group of memory cells formed on an integrated circuit die in the memory device, the memory device may measure signal and noise characteristics of the group of memory cells during execution of the read commands. Based on the signal and noise characteristics the memory sub-system can generate or update, measured during the execution of the read commands a model of changes relevant to reading data from the group of memory cells. The changes can be a result of damage, charge loss, read disturb, cross-temperature effect, etc.
    Type: Grant
    Filed: August 12, 2021
    Date of Patent: February 21, 2023
    Assignee: Micron Technology, Inc.
    Inventors: James Fitzpatrick, Sivagnanam Parthasarathy, Patrick Robert Khayat, AbdelHakim S. Alhussien
  • Patent number: 11587627
    Abstract: A processing device of a memory sub-system is configured to identify a read level of a plurality of read levels associated with a voltage bin of a plurality of voltage bins of a memory device; assign a first threshold voltage offset to the read level of the voltage bin; assign a second threshold voltage offset to the read level of the voltage bin; perform, on block associated with the read level, a first operation of a first operation type using the first threshold voltage offset; and perform, on the blocks associated with the read level, a second operation of a second operation type using the second threshold voltage offset.
    Type: Grant
    Filed: April 16, 2021
    Date of Patent: February 21, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Kishore Kumar Muchherla, Mustafa N Kaynak, Sampath K Ratnam, Shane Nowell, Peter Feeley, Sivagnanam Parthasarathy
  • Patent number: 11587639
    Abstract: A voltage calibration scan is initiated. A first value of a data state metric measured for a sample block of a memory device based on associated with a first bin of blocks designated as a current is received. The first value is designated as a minimum value. A second value of the data state metric for the sample block is measured based on a set of read voltage offsets associated with a second bin of blocks having an index value higher than the current bin. In response to determining that the second value exceeds the first value, the first bin is maintained as the current bin and the voltage calibration scan is stopped.
    Type: Grant
    Filed: March 11, 2021
    Date of Patent: February 21, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Kishore Kumar Muchherla, Mustafa N. Kaynak, Sivagnanam Parthasarathy, Xiangang Luo, Peter Feeley, Devin M. Batutis, Jiangang Wu, Sampath K Ratnam, Shane Nowell, Karl D. Schuh
  • Patent number: 11586679
    Abstract: The present disclosure includes apparatuses and methods for proactive corrective actions in memory based on a probabilistic data structure. A number of embodiments include a memory, and circuitry configured to input information associated with a subset of data stored in the memory into a probabilistic data structure and proactively determine, at least partially using the probabilistic data structure, whether to take a corrective action on the subset of data stored in the memory.
    Type: Grant
    Filed: February 15, 2021
    Date of Patent: February 21, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Saeed Sharifi Tehrani, Sivagnanam Parthasarathy
  • Patent number: 11587624
    Abstract: A memory device to perform a calibration of read voltages of a group of memory cells. For example, the memory device can measure signal and noise characteristics of a group of memory cells to determine an optimized read voltage of the group of memory cells and determine an amount of accumulated storage charge loss in the group of memory cells. Subsequently, the memory device can perform a read voltage calibration based on the determined amount of accumulated storage charge loss and a look up table.
    Type: Grant
    Filed: February 18, 2022
    Date of Patent: February 21, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Patrick Robert Khayat, James Fitzpatrick, AbdelHakim S. Alhussien, Sivagnanam Parthasarathy
  • Publication number: 20230046724
    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 including performing, on data residing in a block of the memory device, an error-handling operation of a plurality of error-handling operations, wherein an order of the plurality of error-handling operations is based on a voltage offset bin associated with the block, wherein the voltage offset bin defines a set of threshold voltage offsets to be applied to a base voltage read level during read operations; and responsive to determining that the error-handling operation has failed to recover the data, adjusting the order of the plurality of error-handling operations.
    Type: Application
    Filed: November 2, 2022
    Publication date: February 16, 2023
    Inventors: Kishore Kumar Muchherla, Shane Nowell, Mustafa N. Kaynak, Sampath K. Ratnam, Peter Feeley, Sivagnanam Parthasarathy, Devin M. Batutis, Xiangang Luo
  • Patent number: 11581047
    Abstract: A memory sub-system configured to use first values of a plurality of optimized read voltages to perform a first read calibration, which determines second values of the plurality of optimized read voltages. A plurality of shifts, from the first values to the second values respectively, can be computed for the plurality of optimized read voltages respectively. After recognizing a pattern in the plurality of shifts that are computed for the plurality of voltages respectively, the memory sub-system can control and/or initiate a second read calibration based on the recognized pattern in the shifts.
    Type: Grant
    Filed: September 24, 2021
    Date of Patent: February 14, 2023
    Assignee: Micron Technology, Inc.
    Inventors: James Fitzpatrick, Sivagnanam Parthasarathy, Patrick Robert Khayat, AbdelHakim S. Alhussien
  • Publication number: 20230044471
    Abstract: Methods, systems, and apparatuses include receiving a codeword stored in a memory device. Energy function values are determined for bits of the codeword based on soft information for the bits of the codeword. A bit of the codeword is flipped when the energy function values for a bit of the codeword satisfies a bit flipping criterion. A corrected codeword that results from the flipping of the bits is returned.
    Type: Application
    Filed: August 9, 2021
    Publication date: February 9, 2023
    Inventors: Mustafa N. KAYNAK, Sivagnanam PARTHASARATHY
  • Patent number: 11562793
    Abstract: A memory sub-system configured to read soft bit data by adjusting the read voltage applied to read hard bit data from memory cells. For example, in response to a read command identifying a group of memory cells, a memory device is to: read the group of memory cells using a first voltage to generate hard bit data indicating statuses of the memory cells subjected to the first voltage; change (e.g., through boosted modulation) the first voltage, currently being applied to the group of memory cells, to a second voltage and then to a third voltage; reading the group of memory cells at the second voltage and at the third voltage to generate soft bit data (e.g., via an exclusive or (XOR) of the results of reading the group of memory cells at the second voltage and at the third voltage).
    Type: Grant
    Filed: May 7, 2020
    Date of Patent: January 24, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Sivagnanam Parthasarathy, James Fitzpatrick, Patrick Robert Khayat, AbdelHakim S. Alhussien
  • Patent number: 11562801
    Abstract: A memory device to estimate signal and noise characteristics of a group of memory cells in response to a command identifying the group of memory cells. For example, the memory device measures first signal and noise characteristics of the group of memory cells based on first test voltages, compute using the first signal and noise characteristics an optimized read voltage of the group of memory cells, and estimate, using the first signal and noise characteristics, second signal and noise characteristics of the group of memory cells, where the second signal and noise characteristics are based on second test voltages that are centered at the optimized read voltage of the group of memory cells.
    Type: Grant
    Filed: September 24, 2021
    Date of Patent: January 24, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Patrick Robert Khayat, Sivagnanam Parthasarathy, James Fitzpatrick