# US 12,007,898 B2 · Utilizing a designated memory address to pre-fetch for memory sub-system with cache > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,007,898 B2 - Document ID: US12007898B2 - Status: Granted - Kind: B2 - Application number: 17/527,811 - Filed: 2021-11-16 - Published: 2022-03-10 - Granted: 2024-06-11 - Earliest claimed: 2019-11-25 - Assignees: Micron Technology, Inc. - Applicants: Micron Technology, Inc. - Inventors: Dhawal Bavishi - Web page: https://patentgrep.com/patent/US12007898B2 ## CPC - G06F 12/0862: with prefetch - G06F 12/0866: for peripheral storage systems, e.g. disk cache - G06F 2212/313: In storage device - G06F 2212/602: Details relating to cache prefetching - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Various embodiments described herein provide for a pre-fetch operation on a memory sub-system, which can help avoid a cache miss when the memory sub-system subsequently processes a read command from a host system. ## Claims ### Claim 1 A memory sub-system comprising: a set of non-volatile memory devices; a cache comprising a volatile memory device; and a processing device, operatively coupled to the set of non-volatile memory devices, configured to perform operations comprising: monitoring a designated memory address on the set of non-volatile memory devices for new command-related data, the designated memory address corresponding to a first location on the set of non-volatile memory devices; receiving, from a host system, a memory sub-system command to write command-related data to the designated memory address, the memory sub-system command comprising a command identifier specifying one of a XWRITE command or a PWRITE in accordance with a Non-Volatile Dual In-Line Memory Module-P (NVDIMM-P) memory protocol, the command-related data comprising a given memory address for a pre-fetch operation; and in response to detecting that the command-related data has been stored at the designated memory address, performing the pre-fetch operation by reading target data from a second location on the set of non-volatile memory devices corresponding to the given memory address, and storing the target data to the cache. ### Claim 2 (depends on 1) The memory sub-system of claim 1, wherein the command-related data comprises a value indicating an amount of data to be read, starting from the given memory address of the memory sub-system, and stored to the cache. ### Claim 3 (depends on 1) The memory sub-system of claim 1, wherein the operations comprise: prior to the performing of the pre-fetch operation: assigning a first priority level to the pre-fetch operation; determining whether a second priority level of a pending non-prefetch operation is higher than the first priority level of the pre-fetch operation; and performing the pre-fetch operation in response to determining that the second priority level is not higher than the first priority level. ### Claim 4 (depends on 3) The memory sub-system of claim 3, wherein the pending non-prefetch operation is requested after the receiving of the memory sub-system command to write the command-related data to the designated memory address. ### Claim 5 (depends on 4) The memory sub-system of claim 4, wherein the assigning of the first priority level to the pre-fetch operation comprises assigning the first priority level to the pre-fetch operation according to at least one of user preference data or quality-of-service setting data accessible by the memory sub-system. ### Claim 6 (depends on 1) The memory sub-system of claim 1, wherein the operations comprise: after the performing of the pre-fetch operation: receiving, from the host system, a second memory sub-system command to perform a read operation with respect to the given memory address of the memory sub-system; and processing the read operation by providing the host system with the target data from the cache. ### Claim 7 A method comprising: monitoring, at a memory sub-system, a designated memory address on a set of non-volatile memory devices for new command-related data, the designated memory address being corresponding to a first location on the set of non-volatile memory devices; receiving, at the memory sub-system from a host system, a memory sub-system command to write command-related data to the designated memory address, the memory sub-system command comprising a command identifier specifying a XWRITE command in accordance with a Non-Volatile Dual In-Line Memory Module-P (NVDIMM-P) memory protocol, the command-related data comprising a given memory address for a pre-fetch operation; and in response to detecting that the command-related data has been stored at the designated memory address, performing the pre-fetch operation by reading target data from a second location on the set of non-volatile memory devices, of the memory sub-system, corresponding to the given memory address, and storing the target data to a cache that comprises a volatile memory device. ### Claim 8 (depends on 7) The method of claim 7, wherein the command-related data comprises a value indicating an amount of data to be read, starting from the given memory address of the memory sub-system, and stored to the cache. ### Claim 9 (depends on 7) The method of claim 7, comprising: prior to the performing of the pre-fetch operation: assigning a first priority level to the pre-fetch operation; determining whether a second priority level of a pending non-prefetch operation is higher than the first priority level of the pre-fetch operation; and performing the pre-fetch operation in response to determining that the second priority level is not higher than the first priority level. ### Claim 10 (depends on 9) The method of claim 9, wherein the pending non-prefetch operation is requested after the receiving of the memory sub-system command to write the command-related data to the designated memory address. ### Claim 11 (depends on 10) The method of claim 10, wherein the assigning of the first priority level to the pre-fetch operation comprises assigning the first priority level to the pre-fetch operation according to at least one of user preference data or quality-of-service setting data accessible by the memory sub-system. ### Claim 12 (depends on 7) The method of claim 7, comprising: after the performing of the pre-fetch operation: receiving, from the host system, a second memory sub-system command to perform a read operation with respect to the given memory address of the memory sub-system; and processing the read operation by providing the host system with the target data from the cache. ### Claim 13 A non-transitory computer-readable storage medium comprising instructions that, when executed by a processing device of a memory sub-system, cause the processing device to perform operations comprising: monitoring a designated memory address on a set of non-volatile memory devices for new command-related data, the designated memory address corresponding to a first location on the set of non-volatile memory devices; receiving, from a host system, a memory sub-system command to write command-related data to the designated memory address, the memory sub-system command comprising a command identifier specifying one of a XWRITE command or a PWRITE in accordance with a Non-Volatile Dual In-Line Memory Module-P (NVDIMM-P) memory protocol, the command-related data comprising a given memory address for a pre-fetch operation; and in response to detecting that the command-related data has been stored at the designated memory address, performing the pre-fetch operation by reading target data from a second location on the set of non-volatile memory devices, of the memory sub-system, corresponding to the given memory address, and storing the target data to a cache the comprises a volatile memory device. ### Claim 14 (depends on 13) The non-transitory computer-readable storage medium of claim 13, wherein the command-related data comprises a value indicating an amount of data to be read, starting from the given memory address of the memory sub-system, and stored to the cache. ### Claim 15 (depends on 13) The non-transitory computer-readable storage medium of claim 13, wherein the operations comprise: prior to the performing of the pre-fetch operation: assigning a first priority level to the pre-fetch operation; determining whether a second priority level of a pending non-prefetch operation is higher than the first priority level of the pre-fetch operation; and performing the pre-fetch operation in response to determining that the second priority level is not higher than the first priority level. ### Claim 16 (depends on 15) The non-transitory computer-readable storage medium of claim 15, wherein the pending non-prefetch operation is requested after the receiving of the memory sub-system command to write the command-related data to the designated memory address. ### Claim 17 (depends on 16) The non-transitory computer-readable storage medium of claim 16, wherein the assigning of the first priority level to the pre-fetch operation comprises assigning the first priority level to the pre-fetch operation according to at least one of user preference data or quality-of-service setting data accessible by the memory sub-system. ### Claim 18 (depends on 13) The non-transitory computer-readable storage medium of claim 13, wherein the operations comprise: after the performing of the pre-fetch operation: receiving, from the host system, a second memory sub-system command to perform a read operation with respect to the given memory address of the memory sub-system; and processing the read operation by providing the host system with the target data from the cache.