Control method of flash memory device and flash memory device
By dynamically calculating the protection threshold of physical blocks in NAND flash memory devices, the problem of damage and data loss caused by blocks not being fully written to is solved, achieving effective protection under different conditions and improving device reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN SHICHUANGYI ELECTRONICS CO LTD
- Filing Date
- 2025-12-19
- Publication Date
- 2026-04-17
AI Technical Summary
In NAND flash memory devices, leaving physical blocks that are not fully written open for extended periods can lead to block corruption and data loss, reducing device reliability.
By dynamically calculating the open time, real-time temperature, and erase cycle count of a first specified type of physical block, first and second protection thresholds are set to proactively prevent physical block errors. This includes scanning and checking the physical block at first preset intervals and taking corresponding measures, such as writing predetermined data or moving data, when the threshold is exceeded.
It effectively prevents damage to physical blocks and data loss, provides an appropriate level of protection under different ambient temperatures and chip wear, and improves the reliability and stability of the device.
Smart Images
Figure CN121879674A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of display technology, and more particularly to a control method for a flash memory device and a flash memory device. Background Technology
[0002] NAND flash memory, as a new type of storage medium, offers advantages over hard disk drives (HDDs) such as large capacity, fast read / write speeds, shock and drop resistance, low power consumption, no noise, and low price, leading to its widespread adoption in consumer PCs and enterprise servers. Data in NAND flash memory is managed in physical blocks, the smallest unit of erasure. A typical physical block contains thousands of pages. During operation, data is continuously written to the pages within a block until all pages in that block are filled, then data is written to the pages of the next block.
[0003] However, during the data writing process, if a block is only partially written without being filled with data, meaning there are free pages in the block, it is considered an open physical block. However, if a block remains open for an extended period, problems such as block corruption and data loss can occur, reducing the reliability of the flash memory device. Summary of the Invention
[0004] The purpose of this application is to provide a control method and a flash memory device, which dynamically calculates a first protection threshold and a second protection threshold for the open time of a first specified type of physical block, thereby actively preventing errors in the first specified type of physical block. The first protection threshold and the second protection threshold can be dynamically adjusted according to ambient temperature or chip wear, providing a suitable level of protection for various operating conditions from mild to harsh.
[0005] This application discloses a control method for a flash memory device, the control method comprising the following steps: The flash memory device is scanned and inspected at first preset intervals for the first specified type of physical blocks. Obtain the physical parameters of the first specified type physical block in the flash memory device; When the physical parameters of the first specified type physical block exceed the first protection threshold, write predetermined data into the current first specified type physical block until one physical word line of the first specified type physical block is filled. When the physical parameters of the first specified type physical block exceed the second protection threshold, the data in the current first specified type physical block is written into a new physical block; The physical parameters of the first specified type of physical block include open time, real-time temperature, and number of erase cycles; The first protection threshold and the second protection threshold are calculated based on the open time, real-time temperature and number of erase cycles of the first specified type of physical block.
[0006] Optionally, the step of obtaining the physical parameters of the first specified type of physical block in the flash memory device includes: Obtain the open time, real-time temperature, and erase cycle count of a first specified type of physical block in the flash memory device; The first protection threshold and the second protection threshold of the first specified type of physical block are calculated by substituting the open time, real-time temperature and erase cycle number of the first specified type of physical block into the threshold calculation formula; Compare the open time of the first specified type physical block with the first protection threshold and the second protection threshold.
[0007] Optionally, the threshold calculation formula is:
[0008] Where t is the real-time temperature, α is the temperature coefficient, β is the wear coefficient, PE_Count is the number of erasure cycles, Delta_time is the reference constant, and T is the critical time; The second protection threshold is less than the critical time, and the second protection threshold is proportional to the critical time or the difference between the second protection threshold and the critical time is a fixed value.
[0009] Optionally, the first protection threshold is less than the second protection threshold; the first protection threshold is equal to the first preset period, the second protection threshold is equal to n times the first preset period, and the second protection threshold is equal to the critical time multiplied by 80%, where n is a natural number greater than 1.
[0010] Optionally, the step of obtaining the physical parameters of the first specified type of physical block in the flash memory device further includes: Obtain the data volume of the first specified type physical block in the flash memory device; The step of writing the data in the current first specified type physical block into a new physical block when the physical parameters of the first specified type physical block exceed the second protection threshold includes: When the data volume of the first specified type physical block is within a first range, and the physical parameters of the first specified type physical block exceed the second protection threshold; Write the data in the current first specified type physical block into a new physical block; The new physical block is entered into the next round as the first specified type of physical block, and the first specified type of physical block is scanned and checked at a first preset interval. When the data volume of the first specified type physical block is in the second range, and the physical parameters of the first specified type physical block exceed the second protection threshold; Write predetermined data into the current first specified type physical block until all physical word lines of the first specified type physical block are filled; Perform a close operation and no longer consider it as the first specified type of physical block; Wherein, the second range is larger than the first range.
[0011] Optionally, the first range is from 0% to 70% of the total space of the physical block of the first specified type; the second range is from 70% to 100% of the total space of the physical block of the first specified type.
[0012] Optionally, the step of scanning and checking the first specified type of physical blocks of the flash memory device at first preset intervals further includes: An ECC error was detected. Data within the physical block where an ECC error occurred is moved to a new physical block; The new physical block is entered into the next round as the first specified type physical block, and the first specified type physical block is scanned and checked at a first preset interval.
[0013] Optionally, the predetermined data is dummy data, and the first specified type physical block is an open physical block; the physical parameters of the first specified type physical block include open time, real-time temperature, and number of erase cycles.
[0014] Optionally, the real-time temperature ranges from 0 degrees Celsius to 70 degrees Celsius, and the number of erasure cycles ranges from 1 to 3000.
[0015] This application also discloses a flash memory device for storing program data, which can be executed to implement the control method of the flash memory device described above.
[0016] This application calculates the first and second protection thresholds using three parameters: the open time of the first specified type of physical block, the real-time temperature, and the number of erase cycles. This allows for dynamic adjustment of the first and second protection thresholds, avoiding the inability to protect data in a timely manner under high temperatures or high PE_Count conditions by setting fixed thresholds. This application employs an adaptive protection algorithm that dynamically calculates the first and second protection thresholds based on the open time of the first specified type of physical block, proactively preventing errors in the first specified type of physical block. The first and second protection thresholds can be dynamically adjusted according to ambient temperature or chip wear, providing appropriate protection levels for various operating conditions from mild to harsh. Attached Figure Description
[0017] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any creative effort. In the drawings: Figure 1 This is a schematic diagram illustrating the steps of a control method for a flash memory device according to this application; Figure 2 This is a schematic diagram of the steps of a first flash memory device control method according to another embodiment of this application; Figure 3 This is a schematic diagram illustrating the steps of a second flash memory device control method according to yet another embodiment of this application; Figure 4 This is a schematic diagram of the data volume of a first specified type physical block according to another embodiment of this application. Detailed Implementation
[0018] It should be understood that the terminology, specific structural and functional details used herein are merely for describing particular embodiments and are representative. However, this application may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.
[0019] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature specified as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. Furthermore, terms such as "upper," "lower," "left," "right," "vertical," and "horizontal," indicating orientation or positional relationships, are based on the orientation or relative positional relationships shown in the accompanying drawings and are only for the purpose of simplifying the description of this application, not indicating that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0020] The present application will now be described in detail with reference to the accompanying drawings and optional embodiments.
[0021] Figure 1 This is a schematic diagram illustrating the steps of a control method for a flash memory device according to this application. See also... Figure 1 As shown, this application discloses a control method for a flash memory device, the control method comprising the following steps: S100: Scan and inspect the first specified type of physical block of the flash memory device at first preset intervals; S200: Obtain the physical parameters of the first specified type physical block in the flash memory device; S300: When the physical parameters of the first specified type physical block exceed the first protection threshold, write predetermined data into the current first specified type physical block until one physical word line of the first specified type physical block is filled. S400: When the physical parameters of the first specified type physical block exceed the second protection threshold, the data in the current first specified type physical block is written into a new physical block; The physical parameters of the first specified type of physical block include open time, real-time temperature, and number of erase cycles; the first protection threshold and the second protection threshold are calculated based on the open time, real-time temperature, and number of erase cycles of the first specified type of physical block.
[0022] This application calculates the first and second protection thresholds using three parameters: the open time of the first specified type of physical block, the real-time temperature, and the number of erase cycles. This allows for dynamic adjustment of the first and second protection thresholds, avoiding the inability to protect data in a timely manner under high temperatures or high PE_Count conditions by setting fixed thresholds. This application employs an adaptive protection algorithm that dynamically calculates the first and second protection thresholds based on the open time of the first specified type of physical block, proactively preventing errors in the first specified type of physical block. The first and second protection thresholds can be dynamically adjusted according to ambient temperature or chip wear, providing appropriate protection levels for various operating conditions from mild to harsh.
[0023] The open time refers to the duration after a physical block is identified as a first-specified type physical block, i.e., the time during which free pages exist within that physical block. Generally, when writing data, if a physical block is not filled, it becomes an open physical block; the first-specified type physical block in this application is an open physical block. Real-time temperature represents the ambient temperature of the first-specified type physical block during the first preset cycle of scanning and inspection, which can be obtained through a temperature sensor on the flash memory device. The erase cycle count (PE_Count), also known as the program / erase cycle count, mainly reflects the wear and tear of the storage cell; the more erase cycles, the weaker the data retention. A longer open time results in poorer data retention within the physical block.
[0024] In this embodiment, the first protection threshold and the second protection threshold are time parameters. By incorporating the open time, real-time temperature, and number of erase cycles into the calculation of the first protection threshold and the second protection threshold, different first protection thresholds and second protection thresholds can be obtained under different temperatures and different number of erase cycles, thereby avoiding data corruption and loss within the first specified type of physical block.
[0025] Specifically, in S100, the first preset period can be a fixed preset value or a dynamic value related to the second protection threshold. For example, if the first preset period is T0, when a fixed value is selected, this fixed value is a multiple of the average value of the second protection threshold. This first preset period allows the flash memory device to scan and check the first specified type of physical blocks at intervals, avoiding the resource waste associated with real-time scanning. Furthermore, the multiple relationship allows for the rapid detection of the first specified type of physical blocks exceeding the first or second protection threshold within a given period.
[0026] Of course, the second protection threshold in this embodiment is variable, that is, the second protection threshold has a maximum value and a minimum value, and the first preset period multiplied by a factor is within the range of the maximum value and the minimum value (including the endpoint value).
[0027] Specifically, the steps in S200 include: S201: Obtain the open time, real-time temperature, and erase cycle count of the first specified type physical block in the flash memory device; S202: Substitute the open time, real-time temperature and erase cycle count of the first specified type physical block into the threshold calculation formula to calculate the first protection threshold and the second protection threshold of the first specified type physical block; S203: Compare the open time of the first specified type physical block with the first protection threshold and the second protection threshold.
[0028] In this implementation, the open time, real-time temperature, and number of erase cycles of the first specified type of physical block are obtained in real time. These three parameters are then substituted into the threshold calculation formula to calculate the real-time first protection threshold and second protection threshold. The open time of the first specified type of physical block is then compared with the first protection threshold and the second protection threshold to actively protect the first specified type of physical block.
[0029] It is understandable that within multiple preset cycles of S100 and S200, there may be multiple instances of S300 or S400 occurring for the first specified type of physical blocks, and each will be executed accordingly. That is, if the opening time of some first specified type of physical blocks exceeds the first protection threshold, or if the opening time of some first specified type of physical blocks exceeds the second protection threshold, then steps S300 and S400 will be executed respectively.
[0030] Specifically, in S300, when the physical parameters of the first specified type physical block exceed the first protection threshold, the pages corresponding to an unfilled physical word line in the first specified type physical block are filled using predetermined data. Since there are no empty pages within that physical word line, this avoids the possibility of charge imbalance within the block caused by empty pages. The first protection threshold T1 can be equal to a first preset period T0, i.e., whether the open time of the first specified type physical block within the scan period exceeds the preset period T0.
[0031] Specifically, in S400, when the physical parameters of the first specified type physical block exceed the second protection threshold, it is determined that the first specified type physical block is about to be damaged. Before the data in the first specified type physical block becomes uncorrectable, the data in the physical block is moved, that is, the data in the current first specified type physical block is written into a new physical block.
[0032] The threshold calculation formula is as follows:
[0033] Where t is the real-time temperature, α is the temperature coefficient, β is the wear coefficient, PE_Count is the number of erase cycles, Delta_time is the baseline constant, and T is the critical time. This threshold calculation formula is mainly used to calculate the second protection threshold, which is the critical time for the first specified type of physical block to be in the open state. After exceeding this critical time T, the Read Error Bit phenomenon is likely to occur. This Read Error Bit problem is mainly caused by the open physical block being in the open state for a long time.
[0034] This threshold calculation formula can be used to establish an accurate prediction model through a systematic two-dimensional experimental design. First, using a first-specified type of physical block with a real-time temperature t of 25℃ and PE_Count of 1 as the environmental conditions, the critical time T at which the first Read Error Bit phenomenon occurs in this first-specified type of physical block is measured. This critical time T can be used as the second protection threshold under the condition of a real-time temperature t of 25℃ and PE_Count of 1. Substituting this critical time T into the above threshold calculation formula, the value of Delta_time can be obtained, and this value is used as a baseline constant.
[0035] Specifically, the real-time temperature ranges from 0 degrees Celsius to 70 degrees Celsius, and the number of erase cycles ranges from 1 to 3000. The temperature coefficient α and the wear coefficient β can be calculated using a two-dimensional experimental matrix. By changing the two variables, real-time temperature and the number of erase cycles, the critical time T for the first occurrence of a Read Error Bit in the first specified type of physical block can be calculated.
[0036] In this embodiment, the real-time temperature is limited to between 0℃ and 70℃, changing every 5℃. PE_Count is between 1 and 3000 cycles, changing every 30 cycles. When PE_Count is fixed, the test covers the entire temperature range from 0℃ to 70℃, changing every 5℃, and a set of critical times is calculated. PE_Count is then changed sequentially, from 1 to 3000 cycles, changing every 30 cycles, to calculate n sets of critical times T. All the real-time temperatures t, erasure cycles PE_Count, and corresponding critical times are integrated, and MATLAB is used to perform multivariate nonlinear regression to fit the threshold formula, thereby obtaining the optimal temperature coefficient α and wear coefficient β.
[0037] In this embodiment, the temperature interval is set to 5°C and the erase cycle interval to 30 times for illustrative purposes. In actual testing, the accuracy can be further increased for more accurate results. However, in reality, since the impact of setting the temperature interval to 5°C and the erase cycle interval to 30 times is relatively small, the result fitted by this temperature interval and erase cycle interval is already quite accurate, and it saves testing time.
[0038] In one specific embodiment, the results of the first protection threshold T1 and the second protection threshold T2 are calculated based on the critical time T. The first protection threshold T1 is equal to the first preset period T0, and the second protection threshold T2 is equal to n times the first preset period T0, where n is a natural number greater than 1. The first protection threshold T1 is less than the second protection threshold T2. Continuing from the above, when the first preset period is a dynamic value, the relationship between the first preset period and the second protection threshold can be set such that the second protection threshold is equal to n times the first preset period, where n is a natural number greater than 1.
[0039] In this embodiment, the second protection threshold is less than the critical time. The second protection threshold is proportional to the critical time, or the difference between the second protection threshold and the critical time is a fixed value. For example, the relationship between the second protection threshold T2 and the critical time T can be: T2*a=T or T-T2=b. The ratio a and the fixed value b can be set according to the actual situation.
[0040] In one scheme, 'a' can be 80%, i.e., T2 = 80% * T. When n equals 16, i.e., T1 = T0 = 5% * T, the first protection threshold T1 is limited to the critical time T multiplied by 5%, and the second protection threshold is equal to the critical time multiplied by 80%, which is used as the early warning threshold time.
[0041] Figure 2 This is a schematic diagram illustrating the steps of a first flash memory device control method according to yet another embodiment of this application. Figure 3This is a schematic diagram illustrating the steps of a second flash memory device control method according to yet another embodiment of this application. Figure 4 This is a schematic diagram of the data volume of a first specified type physical block according to another embodiment of this application, see [link to relevant documentation]. Figures 2 to 4 As shown, based on the above embodiments, the control method includes the following steps: S100: Scan and inspect the first specified type of physical block of the flash memory device at first preset intervals; S201: Obtain the data volume, open time, real-time temperature, and erase cycle count of a first specified type physical block in the flash memory device; wherein, the data volume of the first specified type physical block refers to the data stored in the physical block, and since the physical block is an open physical block, the data does not completely fill all the pages of the physical block.
[0042] S300: When the physical parameters of the first specified type physical block exceed the first protection threshold, write predetermined data into the current first specified type physical block until one physical word line of the first specified type physical block is filled. S401: When the data volume of the first specified type physical block is within a first range, and the physical parameters of the first specified type physical block exceed the second protection threshold; S402: Write the data in the current first specified type physical block into a new physical block; S403: The new physical block is entered into the next round as the first specified type physical block, and the first specified type physical block is scanned and checked at a first preset period interval; S411: When the data volume of the first specified type physical block is in the second range, and the physical parameters of the first specified type physical block exceed the second protection threshold; S412: Write predetermined data to the current first specified type physical block until all physical word lines of the first specified type physical block are filled; S413: Perform a close operation and no longer consider it as the first specified type physical block; Wherein, the second range is larger than the first range.
[0043] In this embodiment, two protection algorithms are designed based on the amount of data stored in the first specified type physical block as a reference. When the amount of data stored in the first specified type physical block is within a first range, i.e., a relatively small amount of data, if its open time exceeds a first protection threshold, a physical word line is filled with predetermined data. If its open time exceeds a second protection threshold, the data in the current first specified type physical block is written into a new physical block, and the new physical block is used as the first specified type physical block in the next round of scanning and checking the first specified type physical block at a first preset interval. Since the data volume is small, the risk of damage during relocation is low, and the time required is short.
[0044] When the amount of data stored in a physical block of the first specified type is in the second range, i.e., a relatively large amount of data, and its open time exceeds the first protection threshold, a physical word line is filled with predetermined data. When its open time exceeds the second protection threshold, all free pages in the current physical block of the first specified type are written with preset data, so that every physical word line is used. At this time, a close operation is performed, treating it as a complete, closable physical block.
[0045] In this application, the preset data is dummy data, which is invalid data without actual user meaning. It is specifically used to fill unused physical word lines in open physical blocks, making the entire physical block reach a "logically closed" state. Its core purpose is to prevent read interference and avoid repeated reading of programmed word lines when they are adjacent to unprogrammed word lines in an open block, which could lead to charge leakage in unprogrammed cells and generate read error bits. At the same time, it can stabilize the storage cell voltage, and filling with dummy data ensures that all word lines are in a programmed state, avoiding threshold voltage shifts caused by uneven electric field distribution on edge word lines (Edge WL).
[0046] Specifically, the first range refers to the data volume of the first specified type of physical block accounting for 0% to 70% (excluding 0% and 70%) of the total physical block space; the second range refers to the data volume of the first specified type of physical block accounting for 70% to 100% (including 70%, but excluding 100%) of the total physical block space. Generally, the data volume of a block = page size * number of pages. For example, a block (120M) = 16KB * 7704. A large data volume would be over 70%, approximately 84M; other cases would be considered small data volumes.
[0047] Specifically, the step of scanning and checking the first specified type of physical blocks of the flash memory device at first preset intervals further includes: S500: An ECC error was detected; S501: Move the data in the physical block where the ECC error occurred to a new physical block; S502: The new physical block is entered into the next round as the first specified type physical block, and the first specified type physical block is scanned and checked at a first preset period interval.
[0048] ECC errors can also occur during the S100 cycle scan check. When an ECC error occurs, the data in the affected physical block should be moved to a new physical block as soon as possible. The physical block with the ECC error may be either a first-specified type physical block filled with preset data or a first-specified type physical block not filled with preset data.
[0049] This application also discloses a flash memory device for storing program data, which can be executed to implement the control method of the flash memory device described above.
[0050] In this application, the actual measured Delta_time is used as a benchmark to ensure the physical accuracy of the model. This benchmark Delta_time represents the data stability under the most typical operating conditions, providing a reliable reference point for the entire algorithm. The threshold calculation formula has a clear physical meaning, avoiding the physical inconsistencies that may arise from purely mathematical fitting. Through two-dimensional experimental design, the actual second protection threshold under all important combinations of real-time temperature and erase cycle count was directly measured. This calculation method can accurately capture the nonlinear interaction effect between the two, accurately predicting data stability under any combination of real-time temperature and erase cycle count, especially maintaining high accuracy under boundary conditions (e.g., high temperature, high erase cycle count). Moreover, the threshold protection algorithm of this application covers the entire operating range that the product may encounter, from low to high temperature, from new chips to the end of their lifespan. In practical applications, the algorithm is always based on interpolation within the measured data range. It provides reliable protection under various extreme operating conditions, completely eliminating the uncertainty risk of traditional methods under boundary conditions.
[0051] Furthermore, by limiting the real-time temperature to between 0℃ and 70℃, changing it every 5℃, and the PE_Count to between 1 and 3000 cycles, changing it every 30 cycles, a large dataset of approximately 15 × 100 = 1500 experimental points showed extremely high statistical significance in parameter fitting. Regression analysis effectively eliminated random errors, yielding parameters that best represent the characteristics of flash memory devices such as NAND chips. The algorithm parameters have excellent generalization ability; the same parameter set is applicable to all chips in the same batch. All products on the same technology platform can reuse this parameter set. The PE_Count, using a 30-cycle interval, ensures both data density and controlled experimental scale. This offers significant cost advantages in large-scale production while ensuring performance consistency across products.
[0052] It should be noted that the inventive concept of this application can form many embodiments, but due to the limited space of the application documents, they cannot all be listed. Therefore, without conflict, the embodiments described above or the technical features can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effect will be enhanced.
[0053] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.
Claims
1. A control method for a flash memory device, characterized in that, Including the following steps: The flash memory device is scanned and inspected at first preset intervals for the first specified type of physical blocks. Obtain the physical parameters of the first specified type physical block in the flash memory device; When the physical parameters of the first specified type physical block exceed the first protection threshold, write predetermined data into the current first specified type physical block until one physical word line of the first specified type physical block is filled. When the physical parameters of the first specified type physical block exceed the second protection threshold, the data in the current first specified type physical block is written into a new physical block; The physical parameters of the first specified type of physical block include open time, real-time temperature, and number of erase cycles; The first protection threshold and the second protection threshold are calculated based on the open time, real-time temperature and number of erase cycles of the first specified type of physical block.
2. The control method for a flash memory device according to claim 1, characterized in that, The step of obtaining the physical parameters of the first specified type of physical block in the flash memory device includes: Obtain the open time, real-time temperature, and erase cycle count of a first specified type of physical block in the flash memory device; The first protection threshold and the second protection threshold of the first specified type of physical block are calculated by substituting the open time, real-time temperature and erase cycle number of the first specified type of physical block into the threshold calculation formula; Compare the open time of the first specified type physical block with the first protection threshold and the second protection threshold.
3. The control method for a flash memory device according to claim 2, characterized in that, The threshold calculation formula is as follows: Where t is the real-time temperature, α is the temperature coefficient, β is the wear coefficient, PE_Count is the number of erasure cycles, Delta_time is the reference constant, and T is the critical time; The second protection threshold is less than the critical time, and the second protection threshold is proportional to the critical time or the difference between the second protection threshold and the critical time is a fixed value.
4. The control method for a flash memory device according to claim 3, characterized in that, The first protection threshold is less than the second protection threshold; The first protection threshold is equal to the first preset period, the second protection threshold is equal to n times the first preset period, and the second protection threshold is equal to the critical time multiplied by 80%, where n is a natural number greater than 1.
5. The control method for a flash memory device according to claim 2, characterized in that, The step of obtaining the physical parameters of the first specified type of physical block in the flash memory device further includes: Obtain the data volume of the first specified type physical block in the flash memory device; The step of writing the data in the current first specified type physical block into a new physical block when the physical parameters of the first specified type physical block exceed the second protection threshold includes: When the data volume of the first specified type physical block is within a first range, and the physical parameters of the first specified type physical block exceed the second protection threshold; Write the data in the current first specified type physical block into a new physical block; The new physical block is entered into the next round as the first specified type of physical block, and the first specified type of physical block is scanned and checked at a first preset interval. When the data volume of the first specified type physical block is in the second range, and the physical parameters of the first specified type physical block exceed the second protection threshold; Write predetermined data into the current first specified type physical block until all physical word lines of the first specified type physical block are filled; Perform a close operation and no longer consider it as the first specified type of physical block; Wherein, the second range is larger than the first range.
6. The control method for a flash memory device according to claim 5, characterized in that, The first range refers to the data volume of the first specified type of physical block accounting for 0% to 70% of the total physical block space; The second range is from 70% to 100% of the total space of the first specified type of physical block.
7. The control method for a flash memory device according to claim 2, characterized in that, The step of scanning and checking the first specified type of physical blocks of the flash memory device at first preset intervals further includes: An ECC error was detected. Data within the physical block where an ECC error occurred is moved to a new physical block; The new physical block is entered into the next round as the first specified type physical block, and the first specified type physical block is scanned and checked at a first preset interval.
8. The control method for a flash memory device according to claim 2, characterized in that, The predetermined data is dummy data, and the first specified type physical block is an open physical block; The physical parameters of the first specified type of physical block include open time, real-time temperature, and number of erase cycles.
9. The control method for a flash memory device according to claim 3, characterized in that, The real-time temperature ranges from 0 degrees Celsius to 70 degrees Celsius, and the number of erasure cycles ranges from 1 to 3000.
10. A flash memory device, characterized in that, The flash memory device is used to store program data, which can be executed to implement the control method of the flash memory device according to any one of claims 1 to 9.