# US 11,307,982 B2 · Memory management method with a data merging process based on risk physical units and distribution counts, memory storage device and memory control circuit unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,307,982 B2 - Document ID: US11307982B2 - Status: Granted - Kind: B2 - Application number: 17/035,604 - Filed: 2020-09-28 - Published: 2022-03-10 - Granted: 2022-04-19 - Earliest claimed: 2020-09-09 - Assignees: Phison Electronics Corp. - Applicants: Phison Electronics Corp. - Inventors: Kuang-Yao Chang; Shin-Wei Gau - Web page: https://patentgrep.com/patent/US11307982B2 ## CPC - G06F 12/0246: {in block erasable memory, e.g. flash memory} - G06F 11/004: {Error avoidance (G06F11/07 and subgroups take precedence)} - G06F 11/3037: {where the computing system component is a memory, e.g. virtual memory, cache (accessing, addressing or allocating within memory systems or architectures G06F12/00; checking stores for correct operation G11C29/00)} - G06F 12/0238: {Memory management in non-volatile memory, e.g. resistive RAM or ferroelectric memory} - G06F 12/0891: using clearing, invalidating or resetting means - G06F 13/1668: {Details of memory controller} - G06F 2201/81: Threshold - G06F 2212/1016: Performance improvement - G06F 2212/7201: Logical to physical mapping or translation of blocks or pages - G06F 2212/7205: Cleaning, compaction, garbage collection, erase control - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A data management method, a memory storage device and a memory control circuit unit. The method includes: executing one or more read commands, and recording a physical unit having a first variation of a read count greater than a read disturb threshold as a risk physical unit; and when a data merging process is performed, dividing valid data stored in the risk physical unit into a plurality of copies and copying the copies into a plurality of recycling units. ## Claims ### Claim 1 A memory management method for a rewritable non-volatile memory module, wherein the rewritable non-volatile memory module comprises a plurality of physical units, and the memory management method comprises: executing one or more read commands, and recording the physical unit having a first variation of read count greater than a read disturb threshold as a risk physical unit; and when a data merging process is performed, dividing data volume of valid data stored in the risk physical unit by a distribution count to generate a to-be-distributed data volume and respectively copying valid data corresponding to the to-be-distributed data volume in the risk physical unit into a plurality of recycling units. ### Claim 2 (depends on 1) The memory management method of claim 1, wherein the step of respectively copying valid data corresponding to the to-be-distributed data volume in the risk physical unit into the plurality of recycling units comprises: selecting one or more of the physical units as the one or more source units according to a data read ratio and a valid data ratio corresponding to the physical units. ### Claim 3 (depends on 2) The memory management method of claim 2, wherein the method further comprises: calculating the data read ratio according to the read counts and a read count threshold corresponding to the physical units; and calculating the valid data ratio according to a data volume of the valid data stored by the physical units and a number of nodes included by the physical units. ### Claim 4 (depends on 1) The memory management method of claim 1, wherein the method further comprises: creating first management information, wherein the first management information is configured to record a risk value of a logical-to-physical mapping table corresponding to the risk physical unit; and when the data merging process is performed, selecting to-be-distributed valid data in the risk physical unit according to the risk value in the first management information. ### Claim 5 (depends on 1) The memory management method of claim 1, wherein the method further comprises: determining whether to start recording the risk physical unit according to a first threshold; and determining whether to perform the data merging process according to a second threshold, wherein the first threshold is different from the second threshold. ### Claim 6 (depends on 1) The memory management method of claim 1, wherein the method further comprises: obtaining the first variation by dividing a variation of the read count by the read count. ### Claim 7 (depends on 1) The memory management method of claim 1, wherein the method further comprises: ranking the first variations of the physical units; and selecting the recycling units according to a ranking order from high to low, wherein the ranking order of the physical unit is higher when a value of the first variation corresponding to the physical unit is smaller. ### Claim 8 A memory storage device, comprising: a connection interface unit, configured to couple to a host system; a rewritable non-volatile memory module, wherein the rewritable non-volatile memory module comprises a plurality of physical units; and a memory control circuit unit, coupled to the connection interface unit and the rewritable non-volatile memory module, wherein the memory control circuit unit is configured to execute one or more read commands, and record the physical unit having a first variation of a read count greater than a read disturb threshold as a risk physical unit, and when a data merging process is performed, the memory control circuit unit is further configured to divide data volume of valid data stored in the risk physical unit by a distribution count to generate a to-be-distributed data volume and respectively copying valid data corresponding to the to-be-distributed data volume in the risk physical unit into a plurality of recycling units. ### Claim 9 (depends on 8) The memory storage device of claim 8, wherein in the operation of respectively copying valid data corresponding to the to-be-distributed data volume in the risk physical unit into the plurality of recycling units, the memory control circuit unit is further configured to select one or more of the physical units as the one or more source units according to a data read ratio and a valid data ratio corresponding to the physical units. ### Claim 10 (depends on 9) The memory storage device of claim 9, wherein the memory control circuit unit is further configured to calculate the data read ratio according to the read counts and a read count threshold corresponding to the physical units, and the memory control circuit unit is further configured to calculate the valid data ratio according to a data volume of the valid data stored by the physical units and a number of nodes included by the physical units. ### Claim 11 (depends on 8) The memory storage device of claim 8, wherein the memory control circuit unit is further configured to create first management information, wherein the first management information is configured to record a risk value of a logical-to-physical mapping table corresponding to the risk physical unit, and when the data merging process is performed, the memory control circuit unit is further configured to select to-be-distributed valid data in the risk physical unit according to the risk value in the first management information. ### Claim 12 (depends on 8) The memory storage device of claim 8, wherein the memory control circuit unit is further configured to determine whether to start recording the risk physical unit according to a first threshold, and the memory control circuit unit is further configured to determine whether to perform the data merging process according to a second threshold, wherein the first threshold is different from the second threshold. ### Claim 13 (depends on 8) The memory storage device of claim 8, wherein the memory control circuit unit is further configured to obtain the first variation by dividing a variation of the read count by the read count. ### Claim 14 (depends on 8) The memory storage device of claim 8, wherein the memory control circuit unit is further configured to rank the first variations of the physical units, and the memory control circuit unit is further configured to select the recycling units according to a ranking order from high to low, wherein the ranking order of the physical unit is higher when a value of the first variation corresponding to the physical unit is smaller. ### Claim 15 A memory control circuit unit for controlling a rewritable non-volatile memory module, wherein the rewritable non-volatile memory module comprises a plurality of physical units, wherein the memory control circuit unit comprises: a host interface, configured to couple to a host system, a memory interface, configured to couple to the rewritable non-volatile memory module; and a memory management circuit, coupled to the host interface and the memory interface; wherein the memory management circuit is configured to execute one or more read commands, and record the physical unit having a first variation of a read count greater than a read disturb threshold as a risk physical unit, and when a data merging process is performed, the memory management circuit is further configured to divide data volume of valid data stored in the risk physical unit by a distribution count to generate a to-be-distributed data volume and respectively copying valid data corresponding to the to-be-distributed data volume in the risk physical unit into a plurality of recycling units. ### Claim 16 (depends on 15) The memory control circuit unit of claim 15, wherein in the operation of respectively copying valid data corresponding to the to-be-distributed data volume in the risk physical unit into the plurality of recycling units, the memory management circuit is further configured to select one or more of the physical units as the one or more source units according to a data read ratio and a valid data ratio corresponding to the physical units. ### Claim 17 (depends on 16) The memory control circuit unit of claim 16, wherein the memory management circuit is further configured to calculate the data read ratio according to the read counts and a read count threshold corresponding to the physical units, and the memory management circuit is further configured to calculate the valid data ratio according to a data volume of the valid data stored by the physical units and a number of nodes included by the physical units. ### Claim 18 (depends on 15) The memory control circuit unit of claim 15, wherein the memory management circuit is further configured to create first management information, wherein the first management information is configured to record a risk value of a logical-to-physical mapping table corresponding to the risk physical unit, and when the data merging process is performed, the memory management circuit is further configured to select to-be-distributed valid data in the risk physical unit according to the risk value in the first management information. ### Claim 19 (depends on 15) The memory control circuit unit of claim 15, wherein the memory management circuit is further configured to determine whether to start recording the risk physical unit according to a first threshold, and the memory management circuit is further configured to determine whether to perform the data merging process according to a second threshold, wherein the first threshold is different from the second threshold. ### Claim 20 (depends on 15) The memory control circuit unit of claim 15, wherein the memory management circuit is further configured to obtain the first variation by dividing a variation of the read count by the read count. ### Claim 21 (depends on 15) The memory control circuit unit of claim 15, wherein the memory management circuit is further configured to rank the first variations of the physical units, and the memory management circuit is further configured to select the recycling units according to a ranking order from high to low, wherein the ranking order of the physical unit is higher when a value of the first variation corresponding to the physical unit is smaller.