TW202011199A - Data storage device and control method for non-volatile memory - Google Patents

Abstract

High-efficiency control technology for non-volatile memory. A controller moves valid data from a first source block to an active block in batches and, between the different batches, write data from a host is allowed to be stored to the active block. In the absence of a second source block, the controller moves each batch with a first amount of data to the active block. On the contrary, the controller moves each batch with a second amount of data to the active block. The second amount of data is greater than the first amount of data, and such a design is intended to accelerate data movement of the first source block.

Description

Data storage device and non-volatile memory control method

This case is about the control of non-volatile memory.

There are many forms of non-volatile memory-for example, flash memory (flash memory), magnetoresistive random access memory (Magnetoresistive RAM), ferroelectric random access memory (Ferroelectric RAM), resistive random access Memory (Resistive RAM), spin transfer torque random access memory (Spin Transfer Torque-RAM, STT-RAM), etc., used for long-term data storage, can be used as a storage medium to achieve a data storage device.

Non-volatile memory usually has its special storage characteristics. The technical field needs to develop corresponding control technologies for the storage characteristics of the corresponding non-volatile memory.

A data storage device implemented according to an embodiment of the present case includes a non-volatile memory and a controller. The controller operates the non-volatile memory according to the requirements of a host. The controller configures an active block from a plurality of idle blocks of the non-volatile memory to fill in the write data requested by the host. The controller further uses the active block as a transfer destination of valid data of a first source block in the non-volatile memory. The controller moves the valid data of the first source block to the active block in a plurality of batches, and allows write data requested by the host to be filled into the active block between different batches. When there is no second source block, the controller causes each batch of the first source block to move a first amount of data. When the second source block exists, the controller causes the batches moving the first source block to move a second amount of data. The second data volume is higher than the first data volume.

In one embodiment, the controller increases the second data amount when there is a third source block.

In one embodiment, the controller allows the effective data of the first source block to be completely moved to the active block before allowing the effective data of the second source block to be moved to the active block.

In one embodiment, the controller sets the amount of data to be moved by the batch of the first source block at the beginning of moving the valid data of the first source block.

In one embodiment, the controller estimates a ratio x:(y-x) based on the number of valid pages x of the first source block and the number of idle pages y of the active block, which is equivalent to 1:n. The controller sets a value a based on the total number of source blocks. The controller sets the value a to a normal value when only the first source block exists, and sets the value a to be greater than the normal value when not only the first source block exists. The controller implements a batch of movement of the first source block and a writing of writing data requested by the host at a ratio of a:n.

In one embodiment, the controller further sets a value M according to the programmed reaction time of the non-volatile memory. After the controller transfers a*M pages of valid data from the first source block to the active block, the controller allows n*M pages requested by the host to write data to fill in the active block.

In one embodiment, after the controller estimates the above values a*M and n*M, it first moves a*M pages of valid data to the active block before allowing the host to write n*M pages of data to fill in the Active block.

In one embodiment, the source block is selected due to the fact that the number of idle blocks should be less than a critical number, or that an error correction or failure is found, or a preventive move is performed, or the loss average is met.

In one embodiment, the controller transfers all the valid data of the first source block to the active block, and then releases the first source block as an idle block before the active block completes the end writing .

The operation of the above controller on the non-volatile memory can also be realized by other structures. In this case, the non-volatile memory control method can be implemented by the aforementioned concept, including: operating a non-volatile memory according to the requirements of a host; configuring a plurality of idle blocks from the non-volatile memory with an active block to fill in the host Requested write data; use the active block as the destination of the effective data of a first source block in the non-volatile memory; move the effective data of the first source block to the active in multiple batches Block, and allow the write data requested by the host to be filled into the active block between different batches; when there is no second source block, make the batches that move the first source block move one each The first data amount; and when the second source block exists, the batches moving the first source block are each moved a second data amount. The second data volume is higher than the first data volume.

The following describes the embodiments in detail and the accompanying drawings to explain the content of the present invention in detail.

The following description lists various embodiments of the present invention. The following description introduces the basic concept of the present invention and is not intended to limit the content of the present invention. The actual scope of invention shall be defined in accordance with the scope of patent application.

Non-volatile memory can be flash memory (Flash Memory), magnetoresistive random access memory (Magnetoresistive RAM), ferroelectric random access memory (Ferroelectric RAM), resistive memory (Resistive RAM, RRAM ), spin transfer torque random access memory (Spin Transfer Torque-RAM, STT-RAM), etc., provide storage media for long-term data storage. The following uses flash memory as an example for discussion.

Today's data storage devices often use flash memory as a storage medium to store user data from the host. There are many types of data storage devices, including products such as Memory Card, USB Flash Device, Solid State Drive (SSD), etc. One application is to use a multi-chip package to package the flash memory and its controller—called an embedded flash memory module (such as eMMC).

A data storage device using flash memory as a storage medium can be applied to various electronic devices. The electronic device includes a smart phone, a wearable device, a tablet computer, a virtual reality device, etc. The computing module of the electronic device can be regarded as a host, which operates the data storage device used to access the flash memory.

A data storage device using flash memory as a storage medium can also be used to construct a data center. For example, a server may operate a solid state drive (SSD) array to form a data center. The server can be regarded as a host, operating the connected solid-state drive to access the flash memory.

FIG. 1 illustrates the data storage device 100 according to an embodiment of the present case. The data storage device 100 includes a flash memory 102 and a controller 104. The host 106 indirectly accesses the flash memory 102 through the controller 104. The controller 104 not only receives and executes the write command from the host (Host) 106, but also actively moves the user data stored in the flash memory 102.

Flash memory has its special storage characteristics, described below.

The host 106 end distinguishes user data by logical address (for example, logical block address LBA or global host page number GHP... etc.). The physical space of the flash memory 102 is divided into a plurality of blocks (Blocks) configuration use. Each block includes multiple pages. Each page includes N sectors (Sectors), N is an integer greater than one, such as: 4. The page of 16KB space can be divided into four sectors, each sector is 4KB. In one embodiment, a block stores data according to the page number, arranged from low to high number.

In one embodiment, the data storage device adopts multi-channel technology, which can virtualize multiple blocks of different channels into a super block, and multiple pages can be virtualized into a super page, and use super blocks and super pages to perform data Storage space management can speed up the data throughput of data storage devices.

The data storage device records the correspondence between the logical address and the physical address of the user data in a logical-physical mapping table (Logical-Physical Mapping Table, L2P Table).

The storage space of the flash memory 102 needs to be erased before it can be used again. The smallest unit of erase (Erase) is a block. Blocks can be divided into data blocks, active blocks and idle blocks. Idle blocks can be used as active blocks to write user data. After the active block is filled with user data, after the closing process (writing EOB (End of Block) information), the active block is changed to a data block. With the update of user data, some user data stored in the data block will be changed from valid data to invalid data. When the user data stored in the data block is all invalid data, it will be changed to an idle block after being erased. In another embodiment, the data block filled with invalid data will be changed to an idle block, and the erasing process will not be executed until the idle block is used as the active block.

The use of flash memory involves data movement procedures, which can be divided into garbage collection procedures and non-garbage collection procedures. When the number of idle blocks is insufficient (for example, less than a critical number TH1), garbage collection (Garbage Collection) can be performed on the storage space. For example, when multiple data blocks (also known as source blocks) only store sporadic valid data, garbage collection can be performed to collect valid data into one active block (also known as destination block) to recover multiple data Blocks, increase the number of idle blocks.

There are many types of non-garbage recycling programs, which are judged based on endangered conditions. For example, data blocks (source blocks) that generate ECC failed also need to be moved to rescue user data that is still readable. In addition, data blocks (source blocks) that are read too frequently also need to be moved to avoid damage to user data caused by the reduced data storage capacity of the data blocks. This operation is also called preventive move (Early Move). In addition, data movement may also be initiated in response to wear leveling considerations between blocks. For example, all user data (including valid and invalid data) of data blocks (source blocks) with low reading frequency Move to the active block (destination block) with a higher erase count to recover the data block. In addition, the wear leveling process can also be combined with the garbage collection process, that is, moving the effective data of multiple data blocks (source blocks) to the active block (destination block) with a higher erase count in the wear leveling process.

It should be noted that the data movement is preferably achieved by means of data copying.

This case proposes a high-efficiency solution to the above effective data movement. Once there is a need to move data, for example, the above garbage collection, error correction failure transfer, preventive transfer, average loss transfer, or other, the transfer technique of this case can be used.

In the figure, the idle blocks of the flash memory 102 are assigned to the idle block pool 108, and the data blocks are assigned to the data block pool 110. When a host 106 issues a write command, or the controller 104 initiates a data movement procedure, the controller 104 selects an idle block from the idle block pool 108 as the active block A0. At this time, the idle area of the idle block pool 108 The number of blocks will be reduced by one. After that, the user data is written into the active block A0. When the active block A0 is closed and becomes a data block, the number of data blocks will increase by one.

The flash memory generally receives the user data of the host in the active block A0. This user data is usually provided by the write command (refer to the host write data path Host_Data). In particular, compared to storing user data from the source block in another active block (called A1 to distinguish it from A0), the controller 104 in this case makes the active block A0 also serve as the destination of the data migration process, and Instead of using active block A1. Once there is a data movement requirement, for example, garbage collection, error correction failure movement, preventive movement, average loss movement, or other, the user data of the source block in the data movement process can be collected to the active block A0( (See the data migration path Blk_Data). . In particular, in this case, the effective data of the same block is divided into multiple batches and moved to the active block A0. This case is for different blocks, and the effective data volume for single batch transfer is adaptively set. The more data blocks generate effective data movement requirements, the higher the effective data volume for single batch movement. The amount of data provided to the active block A0 by the host write data path Host_Data and the data migration path Blk_Data is dynamically allocated. This is discussed in more detail below.

Compared with the conventional technology, the active block A0 and the active block A1 are configured at the same time. For example, the active block A0 has several advantages and is described as follows.

First of all, in this case, the active block A0 can not only store the user data written by the host by the write command, but also store the user data from the source block. Therefore, the usage of idle blocks can be reduced.

In the traditional example of using the active block A1, in response to a sudden power failure event, the Sudden Power Off Recovery (SPOR) procedure must specifically consider the reliability of the data, and will discard the unclosed initiative. Block A1 is still subject to the user data on the source block. Therefore, as long as the active block A1 has not been closed, all source blocks in the data movement process must be retained and cannot be released. The above design obviously hinders the recovery of source blocks, resulting in the number of idle blocks not increasing in time, and even leading to the start of different types of data movement procedures.

Compared with the traditional technology, this case takes the active block A0 as the target block in the data transfer procedure. The SPOR procedure will not completely discard the active block A0. After the data migration is completed, the source block in the data migration process can be recovered without the need to retain it for the SPOR process. Therefore, compared with the traditional technology in which the active block A1 is specifically used as the target block, the number of idle blocks in this case can be effectively increased to overcome the above-mentioned problems.

In addition, in order to close the active block A1 as the target block early, the traditional technology may fill in some dummy data, which will reduce the data storage capacity of the data block and increase the frequency of block erasure , Shorten the life of flash memory. In contrast, using the active block A0 as the destination of the data movement process can avoid writing false data and overcome the above-mentioned problems.

In one embodiment, the controller 104 allows the effective data of one source block (whether it is garbage collection or non-garbage collection) to be completely moved to the active block A0 before allowing another source block (whether it is garbage collection or non-garbage collection). The effective data of garbage collection is moved to the active block A0.

In this case, the effective data of the same source block is moved to the active block A0 in batches. Between each batch, the write data requested by the host can be filled into the active block A0. There can be a proportional relationship between the movement of valid data and the filling of written data from the host. This case adaptively sets the proportional relationship. If there is more than one source block for data movement, this case increases the amount of effective data moved in a single batch, and ends the effective data movement of the current source block early to meet the next source block.

In Figure 1, the write data requested by the host 106 is written to the data path Host_Data via the host. Garbage collection, error correction failure transfer, preventive transfer, loss average transfer, etc., all kinds of effective data transfer to the active block A0 as the destination, shown in Figure 1 is the data transfer path Blk_Data. Anyone who selects a data block from the data block pool 110 as a source block and moves valid data to the active block A0 belongs to the technology covered by the data transfer path Blk_Data. This case is to dynamically allocate the use of the path Host_Data and the path Blk_Data.

In one embodiment, after the previous source block has been moved, the controller 104 allows other source blocks to also use the active block A0 as the effective data transfer destination. For example, after the garbage collection of one source block is completed, the controller 104 allows another source block to use the same active block A0 as the destination for non-garbage collection (error correction failure transfer, preventive transfer, average loss transfer, etc.) Etc.) to move the effective data. For example, after the non-garbage-recovery effective data movement is performed on a source block, the controller 104 allows another source block to use the same active block A0 as a destination to perform non-garbage-recovery effective data movement again. In this way, before the active block A0 is closed (for example, based on whether the EOB information is completed as a criterion), the number of idle blocks has a chance to be fully replenished (more than one idle block can be added).

In one embodiment, the valid data of the same source block is moved to the active block A0 in batches. Between each batch, the write data requested by the host 106 is filled in the active block A0. Or, between batches, the controller 104 causes the flash memory 102 to respond to the host 106's read request. The interval between different batches can be determined by the amount of data written to the host 106 of the active block A0, or can be defined by timing. There may be new effective data transfer requirements between batches. The controller 104 does not process the batch transfer of another source block until the batch transfer of the current source block is completed.

In one embodiment, the controller 104 estimates a ratio based on the effective data amount of a source block and the free space of the active block A0, and sets the effective data amount of each batch moved according to the ratio. According to this ratio, the controller 104 can further set the amount of write data that allows the host 106 to fill the active block A0 between two batches.

There may be more than one source block facing the need for data movement. One embodiment dynamically allocates the above ratio, sets the source block to be processed, and determines the amount of effective data moved in each batch. In one embodiment, there are two source blocks that require data movement. The valid data of the first source block is x pages. The active block A0 has y pages of free space. In this case, a ratio x:(y-x) can be estimated, which is equivalent to 1:n. In this case, the ratio can be adjusted to a:n, where a is a value greater than a normal value. For example, the normal value may be 1, and a may be 2. Considering the response time of flash memory 102 programming (including host 106 writing and source block migration), the migration strategy developed in this case is: each time a*M pages of valid data are moved from the first source block to the active area Block A0 (corresponding path Blk_Data) is interspersed with n*M page write data (corresponding path Host_Data) sent by the active block A0 to store the host 106. The multiple a enables the effective data of the first source block to be collected to the active block A0 early. The controller 104 can move the effective data of the second source block in time. The controller 104 will estimate a new ratio for the effective data amount of the second source block and the free space of the active block A0 at this time. The controller 104 will also confirm whether there are other source blocks to be moved, so as to adjust the ratio and generate a moving strategy suitable for the second source block.

In one embodiment, when the first source block sets the migration strategy, not only the second source block is waiting, but also the third source block needs to be moved. The value of a can be set larger (compared to the example with only the first and second source blocks).

The response time of flash memory 102 programming (including host 106 writing and source block migration) is affected by various factors. In this case, the reaction time was specifically considered, and the aforementioned M value was set. In one embodiment, programming M pages at a time optimizes the writing timing of the flash memory 102. For example, while waiting for the acknowledgement response of the first M-page programming, the second M-page can be cached to the controller 104 to be stored in the flash memory 102: the operating performance is far superior to single-page programming.

In one embodiment, the controller 104 prioritizes data movement, and then considers the host 106's writing requirements. For example, when there is a source block that requires data migration, the controller 104 performs the first batch of data migration after evaluating the migration strategy. After the transfer of the first batch of data is completed, it is allowed to receive the written data requested by the host 106 again. This design ensures that the same source block is collected on the same active block A0.

FIG. 2 is a flowchart illustrating the data movement performed on the flash memory 102 according to an embodiment of the present case.

Step S202: The controller 104 configures the active block A0. The controller 104 configures one of the idle blocks from the idle block pool 108 as the active block A0.

Step S204: The controller 104 determines whether to execute the data transfer procedure? If yes, go to step S212, otherwise go to step S206. When the preset conditions are met, for example, the number of idle blocks is less than the critical number TH1, or any of the error correction failure transfer, preventive transfer, and average loss transfer is generated, the controller 104 starts (executes) the data transfer procedure.

Step S206: The controller 104 determines whether to close the active block A0? If yes, go to step S210, otherwise go to step S208. If the active block A0 still has free space to store data, the controller 104 does not turn off the active block A0.

Step S208: The controller 104 writes the user data from the host 106 to the active block A0, and then returns to step S204. In the above, the controller 104 executes step S204 first, and then executes steps S206 and S208/S210, which means that the controller 104 will preferentially move the user data of the data transfer process. In another embodiment, the controller 104 may arrange step S204 after the user data of the host 106 is filled; under this setting, the controller 104 will preferentially write the user data of the host 106 to the active block A0.

Step S210: The controller 104 turns off the active block A0. If the active block A0 has no free space to store data, the controller 104 closes the active block A0 and writes EOB information to the last page of the active block A0.

If step S204 shows that there is a data movement requirement, the flow proceeds to step S212 to plan a migration strategy for valid data of a source block. The controller 104 not only considers the effective data amount of the source block, the idle state of the active block A0, but also considers whether there are more source blocks to be moved. The controller 104 thus evaluates a migration strategy. For example, each time a*M pages of valid data are moved, the host 106 interspersed with n*M pages writes data. Steps S214 and S216 are executed repeatedly to complete the moving strategy.

Step S214 takes the active block A0 as the destination and moves a*M pages of valid data from the source block. In step S216, the active block A0 restarts the reception of the written data sent from the host 106. The controller 104 allows n*M pages written by the host 106 to fill the active block A0. In step S218, the controller 104 determines whether the effective data transfer of the source block is completed. If not, the flow returns to step S214, and the effective data transfer of the next batch of a*M pages is continued. If step S218 determines that the effective data transfer of the source block is completed, the flow proceeds to step S204 and subsequent steps to plan how to use the active block A0 space to meet another data transfer requirement.

In one embodiment, step S216 may include a time limit judgment. If the time limit is exceeded, the flow proceeds to step S218.

FIG. 3 further describes step S212 in detail according to an embodiment of the present case, in which the number of data transfer pages a*M performed by each batch in step S214 and the number of pages n*M written by the host 106 interspersed in step S216 are determined.

In step S302, the controller 104 estimates a ratio of 1:n based on the effective data amount of the source block and the free space of the active block A0. For example, the effective data of the source block has x pages. Active block A0 has y pages of free space. According to step S302, the controller 104 estimates a ratio x:(y-x), which is equivalent to 1:n.

In step S304, the controller 104 determines whether there are a plurality of source blocks that require data movement. If not, the flow proceeds to step S306. The controller 104 sets the value a to a normal value (for example, 1), indicating that there is no need for accelerated movement. On the contrary, if there are multiple source blocks that need to be moved, the flow proceeds to step S308. The controller 104 makes the value a greater than the normal value (for example, 2) to accelerate the movement. The more source blocks wait for data movement, the larger the value a can be set.

The n value and the planned a value obtained by the program in FIG. 3 are applied to steps S214 and S216 to determine the number of data transfer pages a*M for each batch, and the host 106 to allow interleaving between the batches to write Number of pages n*M.

The user's operating habits may cause the device to repeatedly power off and power on (called power cycling). For example, mobile phone users open the cover to view the information and then cover it. Large amounts of idle blocks are consumed and garbage collection needs occur. Certain blocks may also be read too frequently, leading to ECC failed movement, early move, wear leveling movement, or other valid data movement requests. This case allowed the excessively low number of idle blocks to be replenished in time.

The above operation of the controller 104 on the flash memory 102 may also be implemented by other structures. All the methods of dynamically allocating the active block A0 (for example, the ratio of dynamically allocating the path Blk_Data and the path Host_Data) belong to the scope of protection in this case. In this case, the non-volatile memory control method can be realized by the aforementioned concept.

Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone who is familiar with this skill can do some modifications and retouching without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be as defined in the scope of the attached patent application.

100: data storage device; 102: flash memory; 104: controller; 106: host; 108: idle block pool; 110: data block pool; A0: active block; Blk_Data: data migration path; Host_Data: The host writes the data path; S202...S218, S302...S308: steps.

Figure 1 illustrates a data storage device 100 according to an embodiment of the case; Figure 2 illustrates in a flowchart the data movement performed on the flash memory 102 according to an embodiment of the case; and Figure 3 is more detailed according to an embodiment of the case Step S208 will be described, in which the number of data transfer pages a*M determined in each batch of step S210 and the number of pages n*M written by the host 106 interspersed in step S212 are written.

100: data storage device

102: Flash memory

104: controller

106: Host

108: idle block pool

110: data block pool

A0: Active block

Blk_Data: data migration path

Host_Data: Host write data path

Claims (18)

A data storage device includes: a non-volatile memory; and a controller to operate the non-volatile memory according to the requirements of a host, wherein: the controller configures one from a plurality of idle blocks of the non-volatile memory The active block fills in the write data requested by the host; the controller uses the active block as the destination of the effective data of a first source block in the non-volatile memory; the controller moves in multiple batches Valid data from the first source block to the active block, and allowing the write data requested by the host to fill the active block between different batches; when there is no second source block in the controller, Causing the batches moving the first source block to move a first amount of data; when the controller exists the second source block, the controllers move the batches moving the first source block to a second The amount of data; and the second amount of data is higher than the first amount of data. The data storage device as described in item 1 of the patent application scope, wherein: the controller increases the amount of the second data when there is a third source block. The data storage device as described in item 1 of the patent application scope, wherein: the controller allows the effective data of the first source block to be completely moved to the active block before allowing the effective data of the second source block to be moved To the active block. The data storage device as described in item 3 of the patent application scope, wherein: the controller sets the respective batches of the first source block to be moved when the valid data of the first source block is moved The amount of data. The data storage device as described in item 4 of the patent application scope, wherein: the controller estimates a ratio x:(yx) based on the number of valid pages x of the first source block and the number of idle pages y of the active block, Equivalent to 1:n; the controller sets a value a based on the total number of source blocks; the controller sets the value a as a normal value when only the first source block exists, and not only the first When the source block exists, the value a is set to be greater than the normal value; and the controller performs a batch of movement of the first source block and writing of the write data requested by the host at a ratio of a:n. The data storage device as described in item 5 of the patent application scope, wherein: the controller further sets a value M according to the programmed reaction time of the non-volatile memory; and the controller moves a* from the first source block After M pages of valid data are sent to the active block, n*M pages requested by the host are allowed to write data to fill in the active block. The data storage device as described in item 6 of the patent application scope, in which: after the controller estimates the above values a*M and n*M, it first moves a*M pages of valid data to the active block before allowing the host to request The n*M pages of written data are filled in the active block. The data storage device as described in item 1 of the patent application scope, in which: The source block is selected because the number of idle blocks should be less than a critical number, or the error correction and failure are found, or the preventive removal is carried out, or meets Loss average. The data storage device as described in item 1 of the patent application scope, wherein: after the controller transfers all the valid data of the first source block to the active block, it is released before the end of the active block is written The first source block is an idle block. A non-volatile memory control method, including: operating a non-volatile memory according to the requirements of a host; configuring an active block from a plurality of idle blocks of the non-volatile memory to fill in write data requested by the host; The active block is used as the destination of the effective data of a first source block in the non-volatile memory; the effective data of the first source block is moved to the active block in multiple batches Allowing the write data requested by the host to fill the active block between batches; when there is no second source block, the batches that move the first source block are each moved a first amount of data; and When the second source block exists, the batches that move the first source block are each moved a second amount of data, wherein the second amount of data is higher than the first amount of data. The non-volatile memory control method as described in item 10 of the patent application scope further includes: when there is a third source block, increasing the amount of the second data. The non-volatile memory control method as described in item 10 of the patent application scope further includes: allowing the effective data of the first source block to be completely moved to the active block before allowing the effective of the second source block The data is moved to the active block. The non-volatile memory control method as described in item 12 of the patent application scope further includes: at the beginning of moving the valid data of the first source block, the above batches of the first source block are set to be moved individually The amount of data. The non-volatile memory control method as described in item 13 of the patent application scope further includes: estimating a ratio x based on the number of valid pages x of the first source block and the number of idle pages y of the active block x: (yx ), equivalent to 1:n; set a value a according to the total number of source blocks; when only the first source block exists, set the value a to a normal value, and when not only the first source block exists , Set the value a to be greater than the normal value; and perform a batch of movement of the first source block and write of the write data requested by the host with a ratio of a:n. The non-volatile memory control method as described in item 14 of the patent application scope further includes: setting a value M according to the programmed reaction time of the non-volatile memory; and moving the a*M page from the first source block After valid data is sent to the active block, the n*M pages requested by the host are allowed to write data to fill in the active block. The non-volatile memory control method described in item 15 of the patent application scope further includes: After estimating the above values a*M and n*M, first move the a*M pages of valid data to the active block before allowing the The n*M page write data requested by the host is filled in the active block. The non-volatile memory control method as described in item 10 of the patent application scope, in which: The source block is selected due to the fact that the number of idle blocks should be less than a critical number, or if errors are found to be corrected, or preventive measures are taken. Move, or meet the average loss. The non-volatile memory control method as described in item 10 of the patent application scope further includes: after all the valid data of the first source block is moved to the active block, before the end of the active block is written The first source block is released as an idle block.

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