# US 12,007,838 B2 · Accessing data using error correction operation(s) to reduce latency at a memory sub-system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,007,838 B2 - Document ID: US12007838B2 - Status: Granted - Kind: B2 - Application number: 17/877,637 - Filed: 2022-07-29 - Published: 2024-02-01 - Granted: 2024-06-11 - Earliest claimed: 2022-07-29 - Assignees: Micron Technology, Inc. - Applicants: Micron Technology, Inc. - Inventors: Vamsi Pavan Rayaprolu; Dung Viet Nguyen; Zixiang Loh; Sampath K Ratnam; Patrick R. Khayat; Thomas Herbert Lentz - Web page: https://patentgrep.com/patent/US12007838B2 ## CPC - G06F 11/1044: {with specific ECC/EDC distribution} - G06F 11/1048: {using arrangements adapted for a specific error detection or correction feature} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A request to access data programmed to a memory sub-system is received. A determination is made of whether memory cells of the memory sub-system that store the programmed data satisfy one or more cell degradation criteria. In response to a determination that the memory cells satisfy the one or more cell degradation criteria, an error correction operation to access the data is performed in accordance with the request. ## Claims ### Claim 1 A method comprising: receiving a request to access data programmed to a memory sub-system, wherein the data was programmed to the memory sub-system at a first time period and the request is received at a second time period; determining whether memory cells of the memory sub-system that store the programmed data satisfy one or more cell degradation criteria at least by determining whether a distance between the first time period and the second time period exceeds a time distance threshold; and responsive to determining that the memory cells satisfy the one or more cell degradation criteria, performing an error correction operation to access the data in accordance with the received request. ### Claim 2 (depends on 1) The method of claim 1, further comprising: responsive to determining that the memory cells do not satisfy the one or more cell degradation criteria, performing a read operation to access the data in accordance with the received request. ### Claim 3 (depends on 1) The method of claim 1, wherein determining that the memory cells that store the programmed data satisfy the one or more cell degradation criteria further comprises: determining that a cross temperature associated with the programmed data exceeds a cross temperature threshold, wherein the cross temperature corresponds to a difference between a first temperature of the memory sub-system during a first time period at which the data was programmed to the memory sub-system and a second temperature of the memory sub-system during a second time period at which the request to access the data is received. ### Claim 4 (depends on 1) The method of claim 1, wherein determining that the memory cells that store the programmed data satisfy the one or more cell degradation criteria further comprises: determining that the memory cells is included in a set of memory cells associated with an error rate that exceeds an error rate threshold. ### Claim 5 (depends on 1) The method of claim 1, further comprising determining whether a memory device of the memory sub-system that includes the memory cells satisfies a weak memory device criterion, wherein the error correction operation is performed to access the data further responsive to determining that the memory device satisfies the weak memory device criterion. ### Claim 6 (depends on 5) The method of claim 5, wherein determining that the memory device of the memory sub-system that includes the memory cells satisfies a weak memory device criterion comprises: determining that a region of a substrate that included the memory device is associated with a lower device quality rating than device quality ratings for other regions of the substrate; and determining that a value of one or more probe metrics associated with the memory device exceed a probe metric threshold. ### Claim 7 (depends on 1) The method of claim 1, wherein the error correction operation comprises at least one of a soft decode operation or a corrective read operation. ### Claim 8 (depends on 1) The method of claim 1, wherein the memory cells correspond to at least one of one or more memory pages or one or more blocks at the memory sub-system. ### Claim 9 A system comprising: one or more memory devices; and a processing device coupled to the one or more memory devices, wherein the processing device is to perform operations comprising: receiving a request to access data programmed to memory cells of at least one of the one or more memory devices; determining one or more characteristics associated with the memory cells wherein the one or more characteristics comprise a difference between a first time period at which the data was programmed to the at least one of the one or more memory devices and a second time period at which the request to access the data was received; selecting, from a plurality of error correction operations, a first error correction operation to be performed to access the data in accordance with the request, wherein the first error correction operation is selected in view of the determined one or more characteristics; and performing the first error correction operation to access the data in accordance with the request. ### Claim 10 (depends on 9) The system of claim 9, wherein selecting the first error correction operation to be performed to access the data in accordance with the request comprises: determining whether the one or more characteristics of the memory cells satisfy a first cell degradation criterion or a second cell degradation criterion, wherein the first cell degradation criterion is associated with a first threshold condition that is lower than a second threshold condition associated with the second cell degradation criterion, wherein the first error correction operation is selected to be performed to access the data responsive to determining that the first cell degradation criterion is satisfied based on at least one of the one or more characteristics of the memory cells exceeding the first threshold condition and falling below the second threshold condition of the second cell degradation criterion. ### Claim 11 (depends on 10) The system of claim 10, further comprising: responsive to determining that second cell degradation condition is satisfied based on the at least one of the one or more characteristics of the memory cells exceeding the second threshold condition, selecting a second error correction operation of the plurality of error correction operations to be performed to access the data, wherein the second error correction operation is associated with a latency period that is longer than a latency period for the first error correction operation. ### Claim 12 (depends on 10) The system of claim 10, wherein the one or more characteristics further comprise a cross temperature associated with the data programmed to the memory cells, the first threshold condition corresponds to a first cross temperature threshold, and the second threshold condition corresponds to a second cross temperature threshold. ### Claim 13 (depends on 10) The system of claim 10, wherein the first threshold condition corresponds to a first time difference threshold, and the second threshold condition corresponds to a second time difference threshold. ### Claim 14 (depends on 10) The system of claim 10, wherein the one or more characteristics further comprise an error rate associated with accessing data at the memory cells, the first threshold condition corresponds to a first error rate threshold, and the second threshold condition corresponds to a second error rate threshold. ### Claim 15 (depends on 9) The system of claim 9, further comprising: determining whether the at least one of the one or more memory devices that includes the memory cells satisfies a weak memory device criterion, wherein the first error correction is selected to be performed to access the data in accordance with the request in response to determining that the at least one of the one or more memory devices satisfies the weak memory device criterion. ### Claim 16 (depends on 15) The system of claim 15, wherein determining that the at least one of the one or more memory devices satisfies a weak memory device criterion comprises: determining that a region of a substrate that included the at least one of the one or more memory devices is associated with a lower device quality rating than device quality ratings for other regions of the substrate; and determining that a value of one or more probe metrics associated with the at least one of the one or more memory devices exceed a probe metric threshold. ### Claim 17 (depends on 9) The system of claim 9, wherein the plurality of error correction operations comprises at least one of a soft decode operation or a corrective read operation. ### Claim 18 A non-transitory computer-readable storage medium comprising instructions that, when executed by a processing device, cause the processing device to perform operations comprising: receiving a request to access data programmed to a memory sub-system, wherein the data was programmed to the memory sub-system at a first time period and the request is received at a second time period; determining whether memory cells of the memory sub-system that store the programmed data satisfy one or more cell degradation criteria at least by determining whether a distance between the first time period and the second time period exceeds a time distance threshold; and responsive to determining that the memory cells satisfy the one or more cell degradation criteria, performing an error correction operation to access the data in accordance with the received request. ### Claim 19 (depends on 18) The non-transitory computer-readable storage medium of claim 18, wherein the operations further comprise: responsive to determining that the memory cells do not satisfy the one or more cell degradation criteria, performing a read operation to access the data in accordance with the received request.