Flash memory operation strategy optimization method based on reliability perception and flash memory system

Abstract

The invention discloses a flash memory operation strategy optimization method based on reliability perception and a flash memory system, and belongs to the technical field of chip storage.The method comprises the steps that feature parameters of a current storage unit are obtained to determine the reliability level of the current storage unit and the corresponding failure possibility of the current storage unit; factors influencing the reliability of the storage unit can be perceived so as to determine the intelligent agent of the corresponding level; the selected intelligent agent generates a corresponding operation strategy according to the current state-action value function and the characteristic parameters of the storage unit, and an operation fault-tolerant strategy can be adjusted in real time according to the error characteristics of the storage unit in the storage process, so that the reliability change of the flash memory chip in different application scenes can be adapted through relatively low overhead; data failure is prevented, and data storage reliability is guaranteed; and after the task is executed, an initialization state-action value function when the next task is executed is determined to optimize the flash memory operation of the whole chip in the life cycle, and the service life of the chip is prolonged while the reliability of the flash memory is improved.

Description

Technical Field

[0001] The present invention belongs to the field of chip storage technology, and more specifically, relates to a flash memory operation strategy optimization method based on reliability perception and a flash memory system. Background Art

[0002] Flash memory is a form of electronically erasable programmable read-only memory that allows it to be erased or written multiple times during operation. It is mainly used for general data storage and data exchange and transmission between computers and other digital products, such as memory cards and USB flash drives. Flash memory is a special type of erasable programmable read-only memory that can be erased in blocks, which means that data will not be lost even if the power is turned off.

[0003] During the operation of the storage system, the reliability of the flash memory chip decreases with the increase in the number of write / erase cycles. If the storage unit with low reliability continues to operate, data loss or even damage may occur. It is necessary to design a corresponding operation strategy to discover and correct errors in the memory to avoid storage data failure. In order to avoid data failure problems in the memory, the controller module usually uses error correction code, read reference voltage optimization, bad block management and other methods to ensure that the storage unit can correctly save data information.

[0004] However, during data storage, the reliability of storage cells is affected by many factors. For example, judging the reliability of storage cells based on the number of erases does not optimize the operation strategy based on the actual reliability changes of flash memory chips. When the growth trend of the storage cell bit error rate exceeds expectations, data failure may also occur during the life of the chip. Summary of the invention

[0005] In response to the above defects or improvement needs of the prior art, the present invention provides a flash memory operation strategy optimization method and a flash memory system based on reliability perception, which aims to solve the technical problem of data failure that may occur during the life of the chip when the growth trend of the storage unit bit error rate exceeds expectations.

[0006] To achieve the above object, according to one aspect of the present invention, a flash memory operation strategy optimization method based on reliability perception is provided, comprising: S1: When receiving the current task instruction, initialize the state-action value function; S2: selecting at least one storage unit from the storage module as a current storage unit; obtaining characteristic parameters of the current storage unit, and determining a reliability level of the current storage unit and its corresponding failure probability according to the characteristic parameters of the current storage unit; S3: If the failure possibility indicates that the current storage unit is failed, then proceed to S2; if the failure possibility indicates that the current storage unit is valid, then select an agent applicable to each level according to the reliability level corresponding to the current storage unit; S4: Control the selected agent to generate the current task instruction corresponding to the current operation strategy according to the initialized state-action value function and the characteristic parameters of the current storage unit; S5: Execute the current operation strategy on the current storage unit to obtain a corresponding current execution result; S6: Calculate the operation strategy reward value corresponding to the current execution result, and use the operation strategy reward value to determine a state-action value function from the state-action value function corresponding to the current operation strategy and the state-action value function initialized for this task as the state-action value function to be initialized when executing the next task instruction.

[0007] In one embodiment, if the current task instruction is a write operation, S4 includes: Control the selected agent to update the default write mode and the default storage unit mapping table in the default operation strategy to the target write mode and the target storage unit mapping table respectively according to the initialized state-action value function and the characteristic parameters of the current storage unit, so as to obtain the current operation strategy; The current operation strategy includes: a target write mode, a target storage unit mapping table, a default read mode, a default configuration offset of a read reference voltage, and a default refresh frequency.

[0008] In one of the embodiments, the target storage unit mapping table is generated by the selected agent according to the write priority determined by the storage unit characteristic parameters.

[0009] In one embodiment, the S5 includes: If the current task instruction is a write operation, the current storage unit is selected for a second time, and an address is selected according to the target storage unit mapping table for the second selected current storage unit to execute a write operation instruction corresponding to a target write mode.

[0010] In one embodiment, if the current task instruction is a refresh operation, S4 includes: controlling the selected agent to update the default refresh frequency in the default operation strategy to the refresh frequency according to the initialized state-action value function and the characteristic parameters of the current storage unit to obtain the current operation strategy; The current operation strategy includes: a default write mode, a default storage unit mapping table, a default read mode, a default configuration offset of a read reference voltage, and a target refresh frequency.

[0011] In one embodiment, if the current task instruction is a refresh operation, S5 includes: Selecting an address according to the default storage unit mapping table to execute a write operation instruction corresponding to the default write mode on the current storage unit; Performing a refresh operation on the current storage unit according to the target refresh frequency; Execute a read operation instruction and perform error correction according to the default read mode; when the error correction code capability is not exceeded, record the characteristic parameters of the current storage unit after error correction; when the error correction code capability is exceeded, perform a reread operation on the current storage unit according to the default configuration offset of the read reference voltage until there is no error data, and record the characteristic parameters of the current storage unit after error correction.

[0012] In one embodiment, if the current task instruction is a refresh operation, S4 includes: controlling the selected agent to update the default read mode and the default configuration offset of the read reference voltage in the default operation strategy to the target read mode and the target configuration offset of the read reference voltage according to the initialized state-action value function and the characteristic parameters of the current storage unit, respectively, to obtain the current operation strategy; The current operation strategy includes: a default write mode, a default storage unit mapping table, a target read mode, a target configuration offset of a read reference voltage, and a default refresh frequency.

[0013] In one embodiment, if the current task instruction is a refresh operation, S5 includes: Executing a read operation instruction and performing error correction according to the target read mode; When the error correction code capability is not exceeded, recording the characteristic parameters of the current storage unit after error correction; When the error correction code capability is exceeded, a reread operation is performed on the current storage unit according to the target configuration offset of the read reference voltage until there is no error data, and characteristic parameters of the current storage unit after error correction are recorded.

[0014] In one embodiment, S6 includes: using the formula Calculate the return value of the operation strategy corresponding to the current execution result R i ;in, Er i represents the original bit error rate under the state-action value function corresponding to the current operation strategy, Er i- 1 Represents the original bit error rate under the state-action value function obtained by initializing the current task; when R i= K1, the state-action value function corresponding to the current operation strategy is used as the state-action value function initialized when executing the next task instruction; when R i = K2, the state-action value function corresponding to the current operation strategy is used as the state-action value function initialized when executing the next task instruction.

[0015] According to another aspect of the present invention, there is provided a flash memory system, comprising: a storage module and a processor; A storage module including a plurality of memory cells; A processor connected to the storage module, including: a controller module, a characteristic parameter collection module, a reliability perception module, an intelligent agent cluster and a value function update module connected in sequence; The controller module is used to initialize the state-action value function when receiving the current task instruction; and select at least one storage unit from the storage module as the current storage unit; The characteristic parameter collection module is used to obtain the characteristic parameters of the current storage unit selected by the controller module and transmit them to the reliability perception module; The reliability perception module is used to determine the reliability level of the current storage unit and its corresponding failure probability according to the characteristic parameters of the current storage unit; if the failure probability indicates that the current storage unit is failed, feedback is given to the controller module so that it reselects the current storage unit and determines its failure probability until the selected current storage unit is valid, and selects the intelligent agent applicable to each level according to the reliability level corresponding to the current storage unit; The selected agent is used to generate the current task instruction corresponding to the current operation strategy according to the initialized state-action value function and the characteristic parameters of the current storage unit, and transmit it to the controller module; The controller module is further used to execute the current operation strategy on the current storage unit, obtain the current execution result corresponding to the current task instruction, and transmit it to the value function update module; The value function updating module is used to calculate the operation strategy reward value according to the current execution result corresponding to the current task instruction, and use the operation strategy reward value to determine the state-action value function initialized when the flash memory system executes the next task instruction, and store it in the controller module. Another embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the above method when executed by a processor.

[0016] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art: (1) The present invention provides a flash memory operation strategy optimization method based on reliability perception, which obtains the characteristic parameters of the current storage unit, and determines the reliability level of the current storage unit and its corresponding failure possibility according to the characteristic parameters of the current storage unit, so as to perceive the factors affecting the reliability of the storage unit and then determine the intelligent agent of the corresponding level; the intelligent agent generates a corresponding operation strategy according to the current state-action value function and the characteristic parameters of the storage unit, and can adjust the operation fault tolerance strategy in real time according to the error characteristics of the storage unit during the storage process, so as to adapt to the reliability changes of the flash memory chip in different application scenarios with low overhead, prevent data failure and ensure data storage reliability; after the execution of this task, the state-action value function used for initialization when the next task is executed is also determined, which can improve the reliability of the flash memory while extending the chip life. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A flowchart of a flash memory operation strategy optimization method based on reliability awareness is provided in one embodiment of the present invention.

[0018] Figure 2 A schematic diagram of the structure of a reliability perception module provided in one embodiment of the present invention.

[0019] Figure 3 A diagram showing the correspondence between storage units and agents provided in one embodiment of the present invention.

[0020] Figure 4 This is a diagram showing an example structure of an operation strategy generating agent provided in one embodiment of the present invention.

[0021] Figure 5 An update flow chart of an intelligent agent provided by one embodiment of the present invention.

[0022] Figure 6 A schematic diagram of the structure of a flash memory system provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] This embodiment provides a flash memory operation strategy optimization method based on reliability perception, such as Figure 1As shown, it includes: S1-S6. Among them, S1: when receiving the current task instruction, initialize the state-action value function. S2: select at least one storage unit from the storage module as the current storage unit; obtain the characteristic parameters of the current storage unit, the characteristic parameters of the storage unit are the number of erase and write cycles and the original bit error rate that the storage unit has experienced, and determine the reliability level of the current storage unit and its corresponding failure probability according to the characteristic parameters of the current storage unit; wherein, the storage units can be grouped according to the characteristic parameter settings, and the characteristic parameter values ​​corresponding to each group are different, and the grouping method is shown in the table. S3: If the failure probability indicates that the current storage unit fails, then go to S2; if the failure probability indicates that the current storage unit is valid, then select the intelligent agent applicable to each level according to the reliability level corresponding to the current storage unit. S4: Control the selected intelligent agent to generate the current operation strategy corresponding to the current task instruction according to the initialized state-action value function and the characteristic parameters of the current storage unit. S5: Execute the current operation strategy on the current storage unit to obtain the corresponding current execution result. S6: Calculate the operation strategy reward value corresponding to the current execution result, and use the operation strategy reward value to determine a state-action value function from the state-action value function corresponding to the current operation strategy and the state-action value function initialized for this task as the initialized state-action value function when executing the next task instruction.

[0025] Among them, in S2, the characteristic parameters of the selected storage unit are read, and the original bit error rate is used as an example to describe the possibility of failure. The structure of the reliability perception module is as follows: Figure 2 The reliability perception module determines the possibility of failure as follows: (1) The reliability perception module receives the original bit error rate, and the reliability level classifier determines the reliability level of the storage unit: if the original bit error rate value is in the range of [0.001*(n-1), 0.001*n) (n=1,2,3,4,5), the reliability level of the target storage unit is i; if the original bit error rate is in the range of [0.005,∞), the reliability level of the target storage unit is 6; (2) The reliability perception module determines whether the target storage unit is likely to fail after experiencing 1000*m (m=1, 2,3) write / erase cycles and a refresh interval of d hours (d=720,2160,3600) based on the reliability level. For example, the reliability perception module is implemented through a decision tree. The input of the decision tree is the reliability level of the target storage unit, the possible write / erase cycle 1000*m, and the possible storage time d hours; the output is whether it fails under the input write / erase cycle and storage time; (3) The reliability perception module outputs the judgment result. The storage system assigns agents according to the reliability level of the storage unit output by the reliability perception module. The corresponding relationship between agents and storage units follows Figure 3 For example, the agent assigned to the storage unit of reliability level 1 is the agent to which group 1 belongs.

[0026] The structure of the agent is as follows: Figure 4 As shown. The agent is implemented in the form of Q-table, and the agent state input is the target storage unit reliability level; the agent action is write priority p (p=1, 2, 3), TLC write mode, SLC write mode, read reference voltage step s (s=1, 5, 10), refresh interval d, TLC read mode, SLC read mode. S4 controls the selected agent to generate the current task instruction corresponding to the current operation strategy as follows: (1) Agent reading reliability level; (2) The e-greedy algorithm is used to select the corresponding action combination in the Q-table as the operation strategy of the target storage unit. The e-greedy algorithm process is as follows: a random number is taken between 0 and 1. If the random number is less than or equal to the preset threshold 0.1, an action combination is randomly selected from the action combination corresponding to the state as the operation strategy; otherwise, the action combination with the largest value in the Q-table is selected as the operation strategy; (3) Update the storage unit mapping table according to the write priority p. The mapping table generation rule is as follows: Sort the physical addresses from low to high according to the p value.

[0027] In one of the embodiments, if the current task instruction is a write operation, S4 includes: controlling the selected intelligent agent to update the default write mode and the default storage unit mapping table in the default operation strategy to the target write mode and the target storage unit mapping table respectively according to the initialized state-action value function and the characteristic parameters of the current storage unit, so as to obtain the current operation strategy; wherein the current operation strategy includes: the target write mode, the target storage unit mapping table, the default read mode, the default configuration offset of the read reference voltage, and the default refresh frequency.

[0028] In one of the embodiments, the target storage unit mapping table is generated by the selected agent according to the write priority determined by the storage unit characteristic parameters.

[0029] In one embodiment, S5 includes: if the current task instruction is a write operation, selecting the current storage unit for a second time, and selecting an address according to a target storage unit mapping table for the second selected current storage unit to execute a write operation instruction corresponding to the target write mode.

[0030] In one embodiment, if the current task instruction is a refresh operation, S4 includes: controlling the selected intelligent agent to update the default refresh frequency in the default operation strategy to the refresh frequency according to the initialized state-action value function and the characteristic parameters of the current storage unit, so as to obtain the current operation strategy; wherein the current operation strategy includes: a default write mode, a default storage unit mapping table, a default read mode, a default configuration offset of the read reference voltage, and a target refresh frequency.

[0031] In one of the embodiments, if the current task instruction is a refresh operation, S5 includes: selecting an address according to a default storage unit mapping table to execute a write operation instruction corresponding to a default write mode on the current storage unit; performing a refresh operation on the current storage unit according to a target refresh frequency; executing a read operation instruction according to a default read mode and performing error correction; when the error correction code capability is not exceeded, recording the characteristic parameters of the current storage unit after error correction; when the error correction code capability is exceeded, performing a reread operation on the current storage unit according to a default configuration offset of a read reference voltage until there is no error data, and recording the characteristic parameters of the current storage unit after error correction.

[0032] The process of performing a read-retry operation is as follows: (1) Determine whether the number of original errors in the 2KB codeword exceeds the error correction capability of the error correction code of 100 bits. If so, go to step (2). Otherwise, after decoding, transfer the data to the system and continue to read the next address. (2) Configure the read reference voltage offset step size s; (3) Execute the read operation, decode and determine whether the original number of errors exceeds the error correction code capability. If so, change the step size s and go to step (2). If not, terminate the reread operation and record the current step size s.

[0033] After the reread operation is completed, the number of storage unit write / erase cycles Cpe and the original bit error rate Er under the current operation strategy Si are recorded.

[0034] In one of the embodiments, if the current task instruction is a refresh operation, S4 includes: controlling the selected intelligent agent to update the default read mode and the default configuration offset of the read reference voltage in the default operation strategy to the target read mode and the target configuration offset of the read reference voltage according to the initialized state-action value function and the characteristic parameters of the current storage unit, so as to obtain the current operation strategy; the current operation strategy includes: a default write mode, a default storage unit mapping table, a target read mode, a target configuration offset of the read reference voltage and a default refresh frequency.

[0035] In one of the embodiments, if the current task instruction is a refresh operation, S5 includes: executing a read operation instruction and performing error correction according to a target read mode; when the error correction code capability is not exceeded, recording characteristic parameters of the current storage unit after error correction; when the error correction code capability is exceeded, performing a reread operation on the current storage unit according to a target configuration offset of a read reference voltage until there is no error data, and recording characteristic parameters of the current storage unit after error correction.

[0036] In one embodiment, S6 includes: using the formula Calculate the return value of the operation strategy corresponding to the current execution result R i ;in, Er i Represents the original bit error rate under the state-action value function corresponding to the current operation strategy, Er i- 1 represents the original bit error rate under the state-action value function obtained by initializing the current task; among them, Figure 5 As shown, when R i = K1, the state-action value function corresponding to the current operation strategy is used as the state-action value function initialized when executing the next task instruction; R i = K2, the state-action value function corresponding to the current operation strategy is used as the state-action value function initialized when executing the next task instruction.

[0037] The agent update algorithm used is the SARSA algorithm. The update principle of the SARSA algorithm is as follows: ; ; Where Q represents the value of the agent Q-table, S represents the state set, A represents the action set, α represents the learning rate, R represents the reward value, and γ represents the discount factor. In this embodiment, the value of the learning rate α is 0.2, and the value of the discount factor γ is 0.1.

[0038] Another embodiment of the present invention further provides a flash memory system, such as Figure 6 As shown, it includes: a storage module and a processor; wherein the storage module includes multiple memory units; the processor is connected to the storage module, including: a controller module, a feature parameter collection module, a reliability perception module, an intelligent agent cluster and a value function update module connected in sequence.

[0039] Among them, the controller module is used to initialize the state-action value function when receiving the current task instruction; and select at least one storage unit from the storage module as the current storage unit; the characteristic parameter collection module is used to obtain the characteristic parameters of the current storage unit selected by the controller module and transmit them to the reliability perception module; the reliability perception module is used to determine the reliability level of the current storage unit and its corresponding failure possibility according to the characteristic parameters of the current storage unit; if the failure possibility indicates that the current storage unit is failed, it is fed back to the controller module so that it reselects the current storage unit and determines its failure possibility until the selected current storage unit is valid, and selects the intelligent agent applicable to each level according to the reliability level corresponding to the current storage unit; the selected intelligent agent is used to generate the current operation strategy corresponding to the current task instruction according to the initialized state-action value function and the characteristic parameters of the current storage unit, and transmit it to the controller module; the controller module is also used to execute the current operation strategy on the current storage unit, obtain the current execution result corresponding to the current task instruction, and transmit it to the value function update module; the value function update module is used to calculate the operation strategy return value according to the current execution result corresponding to the current task instruction, and use the operation strategy return value to determine the state-action value function initialized when the flash memory system executes the next task instruction, and store it in the controller module.

[0040] The characteristic parameter collection module includes a buffer unit, a comparator and a counter. When collecting characteristic parameters, the controller performs a write operation on the target storage unit to write data, and the buffer unit caches the written data. Then the controller reads the data of the storage unit, the comparator compares the data in the buffer unit with the read data, and the counter records the number of bits that are inconsistent between the read data and the buffer unit data. The characteristic parameter collection module calculates the original bit error rate and updates the number of write / erase cycles. The calculation formula of the original bit error rate is as follows: original bit error rate = number of error bits / number of written data bits.

[0041] The reliability perception module receives the number of write / erase cycles and the original bit error rate collected by the characteristic parameter collection module, and determines the reliability level of the target storage unit and the possibility of failure of the storage unit.

[0042] The agent cluster includes multiple agents, each of which is responsible for generating an operation strategy for a storage unit of a corresponding reliability level, including: a write operation strategy, a read operation strategy, and a refresh strategy. The storage unit mapping table reads the write priority p output by the agent and generates a mapping relationship between the data address and the physical storage unit according to the p value from low to high. Each group of storage units corresponds to the same mapping table.

[0043] The controller module is responsible for executing write and read instructions according to the operation strategy; when an uncorrectable error occurs, the controller executes a reread operation instruction until the number of uncorrectable errors is 0 or the user terminates the data read operation; when the data retention time of the storage unit reaches the refresh operation interval d, the controller reads the data stored in the storage unit and rewrites it to the storage unit.

[0044] Another embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the above method when executed by a processor.

[0045] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A flash memory operation strategy optimization method based on reliability perception, characterized in that: include: S1: When receiving the current task instruction, initialize the state-action value function; S2: Select at least one storage unit from the storage module as the current storage unit; Acquiring characteristic parameters of the current storage unit, and determining a reliability level of the current storage unit and a corresponding failure probability thereof according to the characteristic parameters of the current storage unit; S3: If the failure possibility indicates that the current storage unit is failed, then proceed to S2; if the failure possibility indicates that the current storage unit is valid, then select an agent applicable to each level according to the reliability level corresponding to the current storage unit; S4: Control the selected agent to generate the current task instruction corresponding to the current operation strategy according to the initialized state-action value function and the characteristic parameters of the current storage unit; S5: Execute the current operation strategy on the current storage unit to obtain a corresponding current execution result; S6: Calculate the operation strategy reward value corresponding to the current execution result, and use the operation strategy reward value to determine a state-action value function from the state-action value function corresponding to the current operation strategy and the state-action value function initialized for this task as the state-action value function to be initialized when executing the next task instruction.

2. The flash memory operation strategy optimization method based on reliability perception as claimed in claim 1, characterized in that: If the current task instruction is a write operation, then S4 includes: Control the selected agent to update the default write mode and the default storage unit mapping table in the default operation strategy to the target write mode and the target storage unit mapping table respectively according to the initialized state-action value function and the characteristic parameters of the current storage unit, so as to obtain the current operation strategy; The current operation strategy includes: a target write mode, a target storage unit mapping table, a default read mode, a default configuration offset of a read reference voltage, and a default refresh frequency.

3. The flash memory operation strategy optimization method based on reliability perception as claimed in claim 2, characterized in that: The target storage unit mapping table is generated by the selected agent determining the write priority according to the storage unit characteristic parameters and then generating the target storage unit mapping table according to the write priority.

4. The flash memory operation strategy optimization method based on reliability perception as claimed in claim 2, characterized in that: The S5 includes: When the current task instruction is a write operation, the current storage unit is selected for a second time, and an address is selected according to the target storage unit mapping table for the second selected current storage unit to execute a write operation instruction corresponding to a target write mode.

5. The flash memory operation strategy optimization method based on reliability perception as claimed in claim 1, characterized in that: If the current task instruction is a refresh operation, S4 includes: controlling the selected agent to update the default refresh frequency in the default operation strategy to the refresh frequency according to the initialized state-action value function and the characteristic parameters of the current storage unit to obtain the current operation strategy; The current operation strategy includes: a default write mode, a default storage unit mapping table, a default read mode, a default configuration offset of a read reference voltage, and a target refresh frequency.

6. The flash memory operation strategy optimization method based on reliability perception as claimed in claim 5, characterized in that: If the current task instruction is a refresh operation, S5 includes: Selecting an address according to the default storage unit mapping table to execute a write operation instruction corresponding to the default write mode on the current storage unit; Performing a refresh operation on the current storage unit according to the target refresh frequency; Execute a read operation instruction and perform error correction according to the default read mode; when the error correction code capability is not exceeded, record the characteristic parameters of the current storage unit after error correction; when the error correction code capability is exceeded, perform a reread operation on the current storage unit according to the default configuration offset of the read reference voltage until there is no error data, and record the characteristic parameters of the current storage unit after error correction.

7. The flash memory operation strategy optimization method based on reliability perception as claimed in claim 1, characterized in that: If the current task instruction is a refresh operation, S4 includes: controlling the selected agent to update the default read mode and the default configuration offset of the read reference voltage in the default operation strategy to the target read mode and the target configuration offset of the read reference voltage according to the initialized state-action value function and the characteristic parameters of the current storage unit, respectively, to obtain the current operation strategy; The current operation strategy includes: a default write mode, a default storage unit mapping table, a target read mode, a target configuration offset of a read reference voltage, and a default refresh frequency.

8. The flash memory operation strategy optimization method based on reliability perception as claimed in claim 7, characterized in that: If the current task instruction is a refresh operation, S5 includes: Executing a read operation instruction and performing error correction according to the target read mode; When the error correction code capability is not exceeded, recording the characteristic parameters of the current storage unit after error correction; When the error correction code capability is exceeded, a reread operation is performed on the current storage unit according to the target configuration offset of the read reference voltage until there is no error data, and characteristic parameters of the current storage unit after error correction are recorded.

9. The flash memory operation strategy optimization method based on reliability perception according to any one of claims 1 to 8, characterized in that: The S6 includes: Using the formula Calculate the return value of the operation strategy corresponding to the current execution result R i ;in, Er i represents the original bit error rate under the state-action value function corresponding to the current operation strategy, Er i- 1 Represents the original bit error rate under the state-action value function obtained by initializing the current task; when R i = K1, the state-action value function corresponding to the current operation strategy is used as the state-action value function initialized when executing the next task instruction; when R i = K2, the state-action value function corresponding to the current operation strategy is used as the state-action value function initialized when executing the next task instruction.

10. A flash memory system, characterized in that: include: A storage module including a plurality of memory cells; A processor connected to the storage module, including: a controller module, a characteristic parameter collection module, a reliability perception module, an intelligent agent cluster and a value function update module connected in sequence; The controller module is used to initialize the state-action value function when receiving the current task instruction; and select at least one storage unit from the storage module as the current storage unit; The characteristic parameter collection module is used to obtain the characteristic parameters of the current storage unit selected by the controller module and transmit them to the reliability perception module; The reliability perception module is used to determine the reliability level of the current storage unit and its corresponding failure probability according to the characteristic parameters of the current storage unit; if the failure probability indicates that the current storage unit is failed, feedback is given to the controller module so that it reselects the current storage unit and determines its failure probability until the selected current storage unit is valid, and selects the intelligent agent applicable to each level according to the reliability level corresponding to the current storage unit; The selected agent is used to generate the current task instruction corresponding to the current operation strategy according to the initialized state-action value function and the characteristic parameters of the current storage unit, and transmit it to the controller module; The controller module is further used to execute the current operation strategy on the current storage unit, obtain the current execution result corresponding to the current task instruction, and transmit it to the value function update module; The value function update module is used to calculate the operation strategy reward value according to the current execution result corresponding to the current task instruction, use the operation strategy reward value to determine the state-action value function initialized when the flash memory system executes the next task instruction, and store it in the controller module.

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