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).

  • Patent number: 11750218
    Abstract: A processing device in a memory system reads a sense word from a memory device and executes a plurality of parity check equations on corresponding subsets of the sense word to determine a plurality of parity check equation results. The processing device determines a syndrome for the sense word using the plurality of parity check equation results, determines whether the syndrome for the sense word satisfies a codeword criterion, and responsive to the syndrome for the sense word not satisfying the codeword criterion, performs an iterative low density parity check (LDPC) correction process, wherein at least one criterion of the iterative LDPC correction process is adjusted after a threshold number of iterations is performed.
    Type: Grant
    Filed: June 2, 2022
    Date of Patent: September 5, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Eyal En Gad, Zhengang Chen, Sivagnanam Parthasarathy, Yoav Weinberg
  • Patent number: 11748013
    Abstract: An initial value of a power cycle count associated with the memory device is identified. The power cycle count is incremented responsive to detecting a powering up of the memory device. Responsive to programming a block residing in the memory device, the block is associated with a current block family associated with the memory device. A currently value of the power cycle count is determined. Responsive to determining that a difference between the initial value of the power cycle count and the current value of the power cycle count satisfies a predefined condition, the current block family is closed.
    Type: Grant
    Filed: September 21, 2022
    Date of Patent: September 5, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Kishore Kumar Muchherla, Mustafa N. Kaynak, Jiangang Wu, Sampath K. Ratnam, Sivagnanam Parthasarathy, Peter Feeley, Karl D. Schuh
  • Patent number: 11740970
    Abstract: A memory sub-system configured to dynamically select an option to process encoded data retrieved from memory cells of a memory component, based on a prediction generated using signal and noise characteristics of memory cells storing the encoded data. For example, the memory component is enclosed in an integrated circuit and has a calibration circuit. The signal and noise characteristics are measured by the calibration circuit as a byproduct of executing a read command in the memory component to retrieve the encoded data. A data integrity classifier configured in the memory sub-system generates a prediction based on the signal and noise characteristics. Based on the prediction, the memory sub-system selects an option from a plurality of options configured in the memory sub-system to process the encoded data.
    Type: Grant
    Filed: March 2, 2020
    Date of Patent: August 29, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Patrick Robert Khayat, James Fitzpatrick, AbdelHakim S. Alhussien, Sivagnanam Parthasarathy
  • Publication number: 20230267968
    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: February 18, 2022
    Publication date: August 24, 2023
    Inventors: Patrick R. Khayat, Steven Michael Kientz, Sivagnanam Parthasarathy, Mustafa N. Kaynak, Vamsi Pavan Rayaprolu
  • Publication number: 20230266901
    Abstract: A processing device in a memory sub-system detects an occurrence of a triggering event, determines respective levels of charge loss associated with a first representative wordline of a block of a memory device and with a second representative wordline of the block of the memory device, and determines whether a difference between the respective levels of charge loss satisfies a threshold criterion. Responsive to determining that the difference between the respective levels of charge loss satisfies the threshold criterion, the processing device further determines that the block is in a uniform charge loss state.
    Type: Application
    Filed: February 18, 2022
    Publication date: August 24, 2023
    Inventors: Patrick R. Khayat, Steven Michael Kientz, Sivagnanam Parthasarathy, Mustafa N. Kaynak, Vamsi Pavan Rayaprolu
  • Patent number: 11735274
    Abstract: A method includes receiving a request to perform a set of read operations. The method includes selecting a random read operation of the set of read operations, where the random read operation is performed on a first wordline located on a first portion of a first data block on a memory device. The method includes performing an error detection operation on a second wordline and a third wordline located on the first portion of the first data block to determine an error rate associated with the second wordline and third wordline, where the second wordline and the third wordline are adjacent to the first wordline. The method includes determining whether the error rate satisfies a threshold criterion responsive to determining that the error rate satisfies the threshold criterion and migrating data stored on the first portion of the first data block to a second data block on the memory device.
    Type: Grant
    Filed: June 10, 2022
    Date of Patent: August 22, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Saeed Sharifi Tehrani, Sivagnanam Parthasarathy
  • Patent number: 11726719
    Abstract: A memory sub-system configured to: measure a plurality of sets of signal and noise characteristics of a group of memory cells in a memory device; determine a plurality of optimized read voltages of the group of memory cells from the plurality of sets of signal and noise characteristics respectively; generate features from the plurality of sets of signal and noise characteristics, including at least one compound feature generated from the plurality of sets of signal and noise characteristics; generate, using the features, a classification of a bit error rate of data retrievable from the group of memory cells; and control an operation to read the group of memory cells based on the classification.
    Type: Grant
    Filed: September 7, 2022
    Date of Patent: August 15, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Sivagnanam Parthasarathy, James Fitzpatrick, Patrick Robert Khayat, AbdelHakim S. Alhussien
  • Patent number: 11726874
    Abstract: A request to retrieve user data stored at a memory device is received and a first error control operation associated with the user data is performed. An indication of a failure of the first error control operation is received, and in response, a subset of system data stored at the memory device is identified. A second error control operation is performed on the subset of the system data to retrieve the subset of the system data stored at the memory device, and the user data is read by using the subset of the system data retrieved based on the performing of the second error control operation.
    Type: Grant
    Filed: March 1, 2021
    Date of Patent: August 15, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Vamsi Rayaprolu, Sivagnanam Parthasarathy, Sampath K. Ratnam, Peter Feeley, Kishore Kumar Muchherla
  • Patent number: 11722151
    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: Grant
    Filed: August 9, 2021
    Date of Patent: August 8, 2023
    Assignee: MICRON TECHNOLOGY, INC.
    Inventors: Mustafa N. Kaynak, Sivagnanam Parthasarathy
  • Patent number: 11720286
    Abstract: An indication of a programming temperature at which data is written at a first location of the memory component is received. If it is indicated that the programming temperature is outside of a temperature range associated with the memory component, the data written to the first location of the memory component is re-written to a second location of the memory component when an operating temperature of the memory component returns within the temperature range.
    Type: Grant
    Filed: November 1, 2021
    Date of Patent: August 8, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Vamsi Pavan Rayaprolu, Sampath K. Ratnam, Sivagnanam Parthasarathy, Mustafa N. Kaynak, Kishore Kumar Muchherla, Shane Nowell, Peter Feeley, Qisong Lin
  • Patent number: 11710527
    Abstract: A determination that a first programming operation has been performed on a particular memory cell can be made. A determination can be made, based on one or more threshold criteria, whether the particular memory cell has transitioned from a state associated with a decreased error rate to another state associated with an increased error rate. In response to determining that the particular memory cell has transitioned from the state associated with the decreased error rate to the another state associated with the increased error rate, an operation can be performed on the particular memory cell to transition the particular memory cell from the another state associated with the increased error rate to the state associated with the decreased error rate.
    Type: Grant
    Filed: July 19, 2022
    Date of Patent: July 25, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Vamsi Pavan Rayaprolu, Kishore Kumar Muchherla, Peter Feeley, Sampath K. Ratnam, Sivagnanam Parthasarathy, Qisong Lin, Shane Nowell, Mustafa N. Kaynak
  • Patent number: 11709727
    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 detecting a read error with respect to data residing in a block of the memory device, wherein the block is associated with a voltage offset bin, determining an ordered set of error-handling operations to be performed to the data, determining a most recently performed error-handling operation associated with the voltage offset bin; adjusting an order of the set of error-handling operations by positioning the most recently performed error-handling operation within a predetermined position in the order of the set of error-handling operations; and performing one or more error-handling operations of the set of error-handling operations in the adjusted order until data associated to the read error is recovered.
    Type: Grant
    Filed: March 30, 2021
    Date of Patent: July 25, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Kishore Kumar Muchherla, Shane Nowell, Mustafa N. Kaynak, Sampath K. Ratnam, Peter Feeley, Sivagnanam Parthasarathy, Devin M. Batutis, Xiangang Luo
  • Patent number: 11711095
    Abstract: A memory device having a Low-Density Parity-Check (LDPC) decoder that is energy efficient and has a low error floor. The decoder is configured to determine syndromes of bits in a codeword, select bits in the codeword based at least in part on the syndromes according to a first mode, and flip the selected bits in the codeword. The decoder can repeat the bit selection and flipping operations to iteratively improve the codeword and reduce parity violations. Further, the decoder can detect a pattern in parity violations of the codeword in its iterative bit flipping operations. In response, the decoder can change from the first mode to a second mode in bit selection for flipping. For example, the decoder can transmit from a dynamic syndrome mode to a static syndrome mode in response to the pattern of repeating a cycle of bit flipping iterations.
    Type: Grant
    Filed: April 26, 2022
    Date of Patent: July 25, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Mustafa N. Kaynak, Sivagnanam Parthasarathy
  • Patent number: 11709734
    Abstract: Methods, systems, and apparatus for error correction with syndrome computation in a memory device are described. A first syndrome for first encoded data is generated in a memory device. The first syndrome and the first encoded data are transmitted to a controller that is coupled with the memory device. A second syndrome for first and second encoded data is generated. The first encoded data and the second encoded data are interrelated according to an error correction code. The second syndrome is transmitted to the controller without the second encoded data and the controller is to decode the first encoded data based on at least one of the first syndrome, the second syndrome, or a combination thereof.
    Type: Grant
    Filed: April 30, 2021
    Date of Patent: July 25, 2023
    Assignee: MICRON TECHNOLOGY, INC.
    Inventors: Mustafa N. Kaynak, Patrick R. Khayat, Sivagnanam Parthasarathy
  • Patent number: 11705925
    Abstract: Methods, systems, and apparatuses include receiving a codeword stored in a memory device. The codeword is error corrected for a first number of iterations. The error correction includes traversing the codeword according to a first order. The codeword is error corrected for a second number of the iterations. The error correction of the codeword during a second iteration from the second number of iterations includes traversing the codeword according to a second order that is different from the first order.
    Type: Grant
    Filed: August 30, 2022
    Date of Patent: July 18, 2023
    Assignee: MICRON TECHNOLOGY, INC.
    Inventors: Mustafa N. Kaynak, Sivagnanam Parthasarathy
  • Patent number: 11693657
    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-serial 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 the 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: December 17, 2019
    Date of Patent: July 4, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Dmitri Yudanov, Sean S. Eilert, Sivagnanam Parthasarathy, Shivasankar Gunasekaran, Ameen D. Akel
  • Publication number: 20230205438
    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: Application
    Filed: February 27, 2023
    Publication date: June 29, 2023
    Inventors: Kishore Kumar Muchherla, Mustafa N. Kaynak, Peter Feeley, Sampath K. Ratnam, Shane Nowell, Sivagnanam Parthasarathy, Karl D. Schuh, Jiangang Wu
  • 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: 11689217
    Abstract: Methods, systems, and apparatuses for stall mitigation in iterative decoders are described. A codeword is received from a memory device. The codeword is iteratively error corrected based on a first bit flipping criterion. A stall condition in the multiple error correction iterations is detected. In response to the detection, the codeword is error corrected based on a second bit flipping criterion that is different from the first bit flipping criterion.
    Type: Grant
    Filed: April 6, 2021
    Date of Patent: June 27, 2023
    Assignee: MICRON TECHNOLOGY, INC.
    Inventors: Mustafa N. Kaynak, Sivagnanam Parthasarathy
  • Publication number: 20230195358
    Abstract: A memory device having a bit-flipping decoder. The decoder having a plurality of circuits operatable to perform parallel computation to decode a codeword according to a plurality of columns of a parity matrix. The decoder is configured to provide columns of the parity matrix for processing in the plurality of circuits in an order where columns processed concurrently by the plurality of circuits in pipeline stages include no more than one parity column of the parity matrix.
    Type: Application
    Filed: December 20, 2021
    Publication date: June 22, 2023
    Inventors: Eyal En Gad, Mustafa N. Kaynak, Sivagnanam Parthasarathy, Yoav Weinberg