Patents by Inventor Johnny A. Lam

Johnny A. Lam 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: 12650766
    Abstract: A data item is programmed to a first set of physical management units (MUs) associated with a memory sub-system in accordance with a first pass programming operation of a multi-pass programming scheme. An entry of a data structure is updated to include a mapping that associates a first physical address associated with the first set of physical MUs with a set of virtual MUs associated with the memory sub-system. A detection is made that a second pass programming operation of the multi-pass programming scheme is initiated to program the data item to a second set of physical MUs associated with the memory sub-system. Responsive to the detecting, the entry of the data structure is updated to include an additional mapping that associates the set of virtual MUs with a second physical address associated with the second set of physical MUs.
    Type: Grant
    Filed: January 10, 2024
    Date of Patent: June 9, 2026
    Assignee: Micron Technology, Inc.
    Inventors: Johnny A. Lam, Samyukta Mudugal, Sanjay Subbarao, Byron D. Harris, Daniel A. Boals
  • Publication number: 20250284429
    Abstract: The memory sub-systems of the present disclosure selects, for memory scans, a memory block which has a highest page fill ratio. In one embodiment, the memory sub-system identifies a number of block stripes located on a logical unit (LU) identified by a logical unit number (LUN), where the LU is one of a plurality of LUs of a memory device. The sub-system determines a fill ratio for each of the plurality of block stripes. The sub-system selects, among the block stripes, a block stripe with a highest fill ratio. The sub-system identifies, from the selected block stripe, a memory block of the LU. The sub-system performs a memory scan operation on the memory block of the memory device.
    Type: Application
    Filed: May 28, 2025
    Publication date: September 11, 2025
    Inventors: Alex J. Wesenberg, Johnny A. Lam, Michael Winterfeld
  • Patent number: 12346594
    Abstract: The memory sub-systems of the present disclosure selects, for memory scans, a memory block which has a highest page fill ratio. In one embodiment, the memory sub-system identifies a number of block stripes located on a logical unit (LU) identified by a logical unit number (LUN), where the LU is one of a plurality of LUs of a memory device. The sub-system determines a fill ratio for each of the plurality of block stripes. The sub-system selects, among the block stripes, a block stripe with a highest fill ratio. The sub-system identifies, from the selected block stripe, a memory block of the LU. The sub-system performs a memory scan operation on the memory block of the memory device.
    Type: Grant
    Filed: November 8, 2023
    Date of Patent: July 1, 2025
    Assignee: MICRON TECHNOLOGY, INC.
    Inventors: Alex J. Wesenberg, Johnny A. Lam, Michael Winterfeld
  • Publication number: 20250190139
    Abstract: A system includes a memory device and a processing device coupled to the memory device. The processing device identifies a logical transfer unit (LTU) corresponding to a logical block address (LBA) specified by a memory access request. The LTU includes a subset of sequential LBAs of a zone of an LBA space of the memory device, where one of the subset is the LBA. The processing device determines a zone identifier (ID) associated with the LTU and retrieves, from a mapping data structure that maps the zone to a subset of a physical address space of the memory device, using the zone ID, metadata that specifies a mapping between the LTU identifier and a physical address of the subset of the physical address space. The processing device performs, using the metadata, a memory access operation specified by the memory access request.
    Type: Application
    Filed: February 19, 2025
    Publication date: June 12, 2025
    Inventor: Johnny A. Lam
  • Patent number: 12265725
    Abstract: A system includes a non-volatile memory device and a processing device to perform operations including creating a logical transfer unit (LTU) corresponding to a logical block address (LBA) received in a read request, wherein the LTU comprises a subset of a plurality of sequential LBAs of a zone of LBA space of the non-volatile memory device, wherein one of the subset is the LBA. The processing device comprises a hardware accelerator to perform operations comprising: retrieving, using an LTU identifier associated with the LTU, metadata that specifies a mapping between the LTU identifier and a physical address of a physical address space; and providing the metadata for use in determining and utilizing the physical address to perform a read operation specified by the read request.
    Type: Grant
    Filed: March 24, 2022
    Date of Patent: April 1, 2025
    Assignee: Micron Technology, Inc.
    Inventor: Johnny A. Lam
  • Publication number: 20240160349
    Abstract: A data item is programmed to a first set of physical management units (MUs) associated with a memory sub-system in accordance with a first pass programming operation of a multi-pass programming scheme. An entry of a data structure is updated to include a mapping that associates a first physical address associated with the first set of physical MUs with a set of virtual MUs associated with the memory sub-system. A detection is made that a second pass programming operation of the multi-pass programming scheme is initiated to program the data item to a second set of physical MUs associated with the memory sub-system. Responsive to the detecting, the entry of the data structure is updated to include an additional mapping that associates the set of virtual MUs with a second physical address associated with the second set of physical MUs.
    Type: Application
    Filed: January 10, 2024
    Publication date: May 16, 2024
    Inventors: Johnny A. Lam, Samyukta Mudugal, Sanjay Subbarao, Byron D. Harris, Daniel A. Boals
  • Publication number: 20240078199
    Abstract: A just-in-time (JIT) scheduling method includes the operations of: receiving a request to perform a memory operation using a hardware resource associated with a memory device; determining a type of the memory operation; identifying a traffic class corresponding to the memory operation; determining, based on the traffic class and the type of the memory operation, whether the memory operation is to be processed during a current scheduling time frame; and responsive to determining the memory operation is to be processed during the current scheduling time frame, submitting the memory operation to the memory device.
    Type: Application
    Filed: November 10, 2023
    Publication date: March 7, 2024
    Inventors: Johnny A. Lam, Alex J. Wesenberg, Guanying Wu, Sanjay Subbarao, Chandra Guda
  • Publication number: 20240078033
    Abstract: The memory sub-systems of the present disclosure selects, for memory scans, a memory block which has a highest page fill ratio. In one embodiment, the memory sub-system identifies a number of block stripes located on a logical unit (LU) identified by a logical unit number (LUN), where the LU is one of a plurality of LUs of a memory device. The sub-system determines a fill ratio for each of the plurality of block stripes. The sub-system selects, among the block stripes, a block stripe with a highest fill ratio. The sub-system identifies, from the selected block stripe, a memory block of the LU. The sub-system performs a memory scan operation on the memory block of the memory device.
    Type: Application
    Filed: November 8, 2023
    Publication date: March 7, 2024
    Inventors: Alex J. Wesenberg, Johnny A. Lam, Michael Winterfeld
  • Patent number: 11922011
    Abstract: A data item is programmed to a first set of management units (MUs) associated with a first portion of one or more memory devices. The first portion includes memory cells of a first type. The first set of MUs is associated with a first physical address. A mapping is generated in a virtual MU data structure that associates the first physical address with a set of virtual MUs associated with the one or more memory devices. An entry associated with the data item is added to a logical-to-physical (L2P) table associated with the one or more memory devices. The entry includes an identifier associated with the set of virtual MUs associated with the one or more memory devices. A detection is made that the data item is programmed to a second set of MUs associated with a second portion of the one or more memory devices. The second portion includes memory cells of a second type. The second set of MUs is associated with a second physical address.
    Type: Grant
    Filed: September 1, 2021
    Date of Patent: March 5, 2024
    Assignee: Micron Technology, Inc.
    Inventors: Johnny A. Lam, Samyukta Mudugal, Sanjay Subbarao, Byron D. Harris, Daniel A. Boals
  • Patent number: 11868643
    Abstract: The memory sub-systems of the present disclosure selects, for memory scans, a memory block which has a highest page fill ratio. In one embodiment, the memory sub-system identifies a number of block stripes located on a logical unit (LU) identified by a logical unit number (LUN), where the LU is one of a plurality of LUs of a memory device. The sub-system determines a fill ratio for each of the plurality of block stripes. The sub-system selects, among the block stripes, a block stripe with a highest fill ratio. The sub-system identifies, from the selected block stripe, a memory block of the LU. The sub-system performs a memory scan operation on the memory block of the memory device.
    Type: Grant
    Filed: December 16, 2020
    Date of Patent: January 9, 2024
    Assignee: Micron Technology, Inc.
    Inventors: Alex J. Wesenberg, Johnny A. Lam, Michael Winterfeld
  • Patent number: 11714562
    Abstract: A memory system identifies, in a logical to physical (L2P) journal associated with a memory device, a first journal entry reflecting a two pass programming operation, where the two pass programming operation includes a first pass to program data to a second memory location identified by a second physical address and a second pass to program a same data to a same second memory location identified by a same second physical address. The system determines whether the second pass of the two pass programming operation is complete. Responsive to determining that the second pass of the two pass programming operation is complete, the system causes a second journal entry of the L2P journal to reference from a first physical address to the second physical address. The system reconstructs the L2P table based on the second journal entry.
    Type: Grant
    Filed: February 18, 2021
    Date of Patent: August 1, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Johnny A. Lam, Sanjay Subbarao, Samyukta Mudugal
  • Patent number: 11681629
    Abstract: A system includes a memory device; a volatile memory comprising buffers; and a processing device to perform operations comprising: accessing a read command having a first command tag, the first command tag comprising a first logical transfer unit (LTU) value and a first buffer address for a first buffer, the first LTU value being mapped from a zone of a plurality of sequential logical block address (LBA) values to a first physical address, of the memory device, at which is stored first data; and generating a set of command tags that are to cause second data to be retrieved from the memory device and stored in a set of the buffers, wherein the set of command tags comprises at least a second command tag associated with a second physical address that sequentially follows the first physical address.
    Type: Grant
    Filed: May 12, 2022
    Date of Patent: June 20, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Chandra M. Guda, Johnny A. Lam
  • Patent number: 11640354
    Abstract: A system includes integrated circuit (IC) dies having memory cells and a processing device, which is to perform operations including generating a number of zone map entries for zones of a logical block address (LBA) space that are sequentially mapped to physical address space of the plurality of IC dies, wherein each zone map entry corresponds to a respective data group that has been sequentially written to one or more IC dies; and generating a die identifier and a block identifier for each data block of multiple data blocks of the respective data group, wherein each data block corresponds to a media block of the plurality of IC dies.
    Type: Grant
    Filed: January 10, 2022
    Date of Patent: May 2, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Sanjay Subbarao, Johnny A. Lam, John E. Maroney, Mark Ish
  • Publication number: 20230061180
    Abstract: A data item is programmed to a first set of management units (MUs) associated with a first portion of one or more memory devices. The first portion includes memory cells of a first type. The first set of MUs is associated with a first physical address. A mapping is generated in a virtual MU data structure that associates the first physical address with a set of virtual MUs associated with the one or more memory devices. An entry associated with the data item is added to a logical-to-physical (L2P) table associated with the one or more memory devices. The entry includes an identifier associated with the set of virtual MUs associated with the one or more memory devices. A detection is made that the data item is programmed to a second set of MUs associated with a second portion of the one or more memory devices. The second portion includes memory cells of a second type. The second set of MUs is associated with a second physical address.
    Type: Application
    Filed: September 1, 2021
    Publication date: March 2, 2023
    Inventors: Johnny A. Lam, Samyukta Mudugal, Sanjay Subbarao, Byron D. Harris, Daniel A. Boals
  • Patent number: 11561855
    Abstract: A system including a memory device having blocks of memory cells and a processing device operatively coupled to the memory device. The processing device to perform operations comprising: detecting an error event triggered within a source block of the memory cells; reading data from the source block; writing the data into a mitigation block that is different than the source block; and replacing, in a mapping data structure, a first identifier of the source block with a second identifier of the mitigation block.
    Type: Grant
    Filed: November 18, 2021
    Date of Patent: January 24, 2023
    Assignee: Micron Technology, Inc.
    Inventor: Johnny A. Lam
  • Patent number: 11537512
    Abstract: An example memory sub-system includes a memory device and a processing device, operatively coupled to the memory device. The processing device is configured to maintain a logical-to-physical (L2P) table, wherein a region of the L2P table is cached in a volatile memory; maintain a write count reflecting a number of bytes written to the memory device; maintain a cache miss count reflecting a number of cache misses with respect to a cache of the L2P table; responsive to determining that a value of a predetermined function of the write count and the cache miss count exceeds a threshold value, copy the region of the L2P table to a non-volatile memory.
    Type: Grant
    Filed: October 21, 2021
    Date of Patent: December 27, 2022
    Assignee: MICRON TECHNOLOGY, INC.
    Inventors: Michael Winterfeld, Steven S. Williams, Alex J. Wesenberg, Johnny A. Lam
  • Patent number: 11461233
    Abstract: A system includes a non-volatile memory (NVM), and a volatile memory to store: a zone map data structure (ZMDS) that maps a zone of a logical block address (LBA) space to a zone index; and a high frequency update table (HFUT). A processing device is to: write, within an entry of the HFUT, a value of a zone write pointer corresponding to the zone index for an active zone, wherein the zone write pointer includes a location in the LBA space for the active zone; write, within an entry of the ZMDS, a table index value that points to the entry of the HFUT; and journal metadata of the entry of one the ZMDS or the HFUT affected by a flush transition between the ZMDS and the HFUT.
    Type: Grant
    Filed: April 16, 2021
    Date of Patent: October 4, 2022
    Assignee: Micron Technology, Inc.
    Inventors: Johnny A. Lam, Alex J. Wesenberg, Michael Winterfeld
  • Publication number: 20220269611
    Abstract: A system includes a memory device; a volatile memory comprising buffers; and a processing device to perform operations comprising: accessing a read command having a first command tag, the first command tag comprising a first logical transfer unit (LTU) value and a first buffer address for a first buffer, the first LTU value being mapped from a zone of a plurality of sequential logical block address (LBA) values to a first physical address, of the memory device, at which is stored first data; and generating a set of command tags that are to cause second data to be retrieved from the memory device and stored in a set of the buffers, wherein the set of command tags comprises at least a second command tag associated with a second physical address that sequentially follows the first physical address.
    Type: Application
    Filed: May 12, 2022
    Publication date: August 25, 2022
    Inventors: Chandra M. Guda, Johnny A. Lam
  • Publication number: 20220214830
    Abstract: A system includes a non-volatile memory device and a processing device to perform operations including creating a logical transfer unit (LTU) corresponding to a logical block address (LBA) received in a read request, wherein the LTU comprises a subset of a plurality of sequential LBAs of a zone of LBA space of the non-volatile memory device, wherein one of the subset is the LBA. The processing device comprises a hardware accelerator to perform operations comprising: retrieving, using an LTU identifier associated with the LTU, metadata that specifies a mapping between the LTU identifier and a physical address of a physical address space; and providing the metadata for use in determining and utilizing the physical address to perform a read operation specified by the read request.
    Type: Application
    Filed: March 24, 2022
    Publication date: July 7, 2022
    Inventor: Johnny A. Lam
  • Publication number: 20220197563
    Abstract: The memory sub-systems of the present disclosure discloses a simulator to simulate a QoS latency model for a just-in-time (JIT) scheduler. In one embodiment, a system receives a workload profile specifying a sequence of memory operations, wherein each memory operation is associated with a type of the memory operation. The system identifies a traffic class associated with each memory operation of the sequence of memory operations. The system queues each memory operation of the sequence of memory operations, based on the traffic class associated with the memory operation, in a scheduling pool of a number of scheduling pools. The system selects, based on a quality of service (QoS) policy, from the scheduling pools, one or more memory operations to be serviced within a scheduling time frame. The system determines, based on a latency profile, latency periods for each memory operation of the one or more memory operations.
    Type: Application
    Filed: August 20, 2021
    Publication date: June 23, 2022
    Inventors: Johnny A. Lam, Alex J. Wesenberg, Guanying Wu, Sanjay Subbarao, Chandra Guda