WO2015185002A1

WO2015185002A1 - Method and device for writing data

Info

Publication number: WO2015185002A1
Application number: PCT/CN2015/080779
Authority: WO
Inventors: 石亮; 沙行勉; 朱冠宇; 赵俊峰
Original assignee: 华为技术有限公司
Priority date: 2014-06-06
Filing date: 2015-06-04
Publication date: 2015-12-10
Also published as: CN105242871A; CN105242871B

Abstract

A method and device for writing data, for use in solving the problem that a major conflict is found between the flash memory lifespan of an SSD and use performance of the SSD. The method for writing data comprises: an SSD controller determines a write speed and a data retention duration on the basis of a current average of programming/erasing (P/E) cycles executed with respect to each flash memory chip of the flash memory of an SSD and of correlations of a predetermined range of P/E cycles respectively to write speeds and data retention durations (S401); the SSD controller executes write operations other than refresh operations with respect to the flash memory of the SSD on the basis of the determined write speed, and executes the refresh operations with respect to written data in the flash memory on the basis of the determined data retention duration and of the determined write speed, where the refresh operations are rewriting of data that have been stored in the flash memory for a duration exceeding the data retention duration from the location last written to another location in the flash memory (S402).

Description

Data writing method and device

Technical field

The present invention relates to the field of computer technologies, and in particular, to a data writing method and apparatus.

Background technique

Solid State Disk (SSD) is a commonly used data carrier in the storage field. Due to its high performance, low latency, low power consumption, and strong environmental adaptability, the cost is also decreasing, so the application is becoming more and more popular.

SSDs can use flash memory as a storage medium. In general, people often use the speed of writing to SSD flash (that is, write speed) to measure the performance of SSD. The higher the write speed, the better the performance of the SSD is usually indicated. The write speed is proportional to the programming voltage at which the write operation is performed. The higher the write speed, the larger the programming voltage. The programming voltage here is the charging voltage step used when programming each memory cell (ie, writing data). The storage unit is divided into a single level unit (SLC) and a multi-level unit (MLC). The size of each SLC is 1 bit, and the size of each MLC is 2 bits. As shown in Fig. 1(a) and Fig. 1(b), threshold voltages (V for each MLC data (11, 10, 01, and 00, respectively) at the program voltages ΔVpp1 and ΔVpp2 (ΔVpp1 < ΔVpp2), respectively. _th) distribution of FIG. It can be seen from the figure that the larger the programming voltage is, the larger the distribution range of the threshold voltage corresponding to the stored data is, and the smaller the interval between the threshold voltages of different stored data is. If electrons are lost in the memory cell, the threshold voltage will change, as shown in Figure 2, which is a schematic diagram of the threshold voltage change caused by electron loss; in this case, the interval between threshold voltages of different stored data is smaller. The easier it is to cause errors in stored data.

For an SSD, the total number of Program/Erase (P/E) times that can be performed for each flash block in the flash memory can be used to measure the lifetime of the SSD flash. The one-time P/E operation refers to performing an erase operation on the stored data of the entire flash block in units of flash blocks after performing at least one write operation on the flash block in units of pages. P/E operation will cause wear and tear on the flash memory of the SSD. The insulation of the bad flash memory causes electron loss. Therefore, the more P/E operations performed on a flash block, the more error-prone the data stored in the flash block is. The SSD controller can use the Error Correcting Code (ECC) to correct the read stored data. However, if the degree of error in the stored data exceeds the error correction range of the ECC, the ECC cannot perform the stored data. Error correction means the end of SSD flash life.

In order to improve the performance of SSD, people generally set the write speed to be large. It can be seen from the above analysis that the larger the write speed, the smaller the interval between threshold voltages of different memory cells, and the greater the probability and error degree of storing data errors. Especially in the later life of SSD flash memory, since more than one P/E operation has been performed, the electron loss rate becomes very fast. If a large write speed is still used at this time, it is easy to cause storage data errors and store data. Once the error level exceeds the ECC's error correction range, it will lead to the end of SSD flash life.

In summary, there is a big contradiction between the flash memory life of SSD and the performance of SSD: if a large write speed is used in order to improve the performance of SSD, it is easy to cause a large degree of error in the storage data at the end of the life of the SSD flash memory. The life of SSD flash memory; if you use a small write speed to extend the life of SSD flash, it reduces the performance of SSD.

Summary of the invention

The embodiment of the invention provides a data writing method and device, which are used to solve the problem that there is a large contradiction between the flash memory life of the SSD and the performance of the SSD.

In a first aspect, a data writing method is provided, including:

The SSD controller corresponds to the average of the program/erase P/E times currently performed for each flash block in the flash memory of the SSD, and the preset P/E number range respectively, corresponding to the write speed and the data storage duration. Relationship, determine the write speed and data retention time;

The SSD controller performs a write operation other than the refresh operation on the flash memory of the SSD according to the determined write speed, and

Performing on the data written to the flash memory according to the determined data save duration and the determined write speed a refresh operation; the refresh operation is to rewrite data in the flash memory whose storage time exceeds the data storage duration from the last written location to another location in the flash memory.

With reference to the first aspect, in a first possible implementation manner, the SSD controller performs a write operation other than a refresh operation on the flash memory of the SSD, including:

After receiving the write request sent by the host, the SSD controller performs a write operation on the flash memory of the SSD according to the write request; or

The SSD controller writes valid data in the flash block containing the invalid data into the blank flash page after determining that the ratio of the number of blank flash blocks in the flash memory in the flash memory is lower than a set threshold.

With reference to the first aspect, or the first possible implementation manner of the first aspect, in a second possible implementation manner, the SSD controller performs an average of P/ performed on each flash block in the flash memory. The E times, and the preset P/E number range respectively correspond to the writing speed and the data saving duration, and determine the writing speed and the data saving duration, including:

Determining, by the SSD controller, a write speed and a data retention duration corresponding to each data attribute according to a current P/E number of times performed on each flash block in the flash memory and a correspondence table corresponding to each data attribute. Wherein, the corresponding relationship table records a correspondence between a preset P/E number of times range and a writing speed and a data saving duration; the data attribute includes hot data and cold data, and the access frequency of the hot data is greater than The frequency of access to the cold data;

The SSD controller performs a write operation other than the refresh operation on the flash memory of the SSD according to the determined write speed, including: the SSD controller needs to write to the flash memory according to the write operation other than the refresh operation Data attribute of the data, selecting a write speed from the determined write speed corresponding to each data attribute, and performing a write operation other than the refresh operation on the flash memory of the SSD according to the selected write speed;

The SSD controller performs a refresh operation on the data written in the flash memory according to the determined data save duration and the determined write speed, including: the SSD controller determines from the data attribute of the data written in the flash memory Select the data to save in the data retention time corresponding to each data attribute. The duration, according to the selected data save duration and the write speed corresponding to the cold data, performs a refresh operation on the data written to the flash memory.

With reference to the second possible implementation manner of the first aspect, in a third possible implementation manner, the SSD controller performs the write operation except the refresh operation on the flash memory of the SSD according to the selected write speed ,include:

The SSD controller writes data to the flash memory in units of pages according to the selected write speed; for each page of the write data, the out-of-band OOB information of the page is recorded in the page, the OOB information The page number including the page, the page number of the previous page adjacent to the page in the write order, the page number of the next page adjacent to the page in the write order, and the data written on the page Time; and

After writing data to any page in the flash memory, updating the expiration time queue information corresponding to the data attribute maintained by the SSD controller according to the data attribute of the written data; the expiration time queue information includes The page number of the page in which the data with the data attribute is written and not updated, the page number of the page on which the data was first written, and the page number of the page on which the data was last written;

The SSD controller performs a refresh operation on the data written in the flash memory according to the selected data save duration and the write speed corresponding to the cold data, including:

For any data attribute, the SSD controller is based on a preset refresh period, according to the page number of the page of the earliest written data or the last write data in the expiration time queue information corresponding to the data attribute. The page number of the page, the OOB information of the page in which the data is written in the flash memory, and the selected data storage duration, and the page that needs to perform the refresh operation is determined;

The SSD controller performs a refresh operation on the determined page that needs to perform the refresh operation according to the write speed corresponding to the cold data, records the OOB information of the refreshed page, and updates the invalidation time queue information corresponding to the cold data.

With reference to the first aspect, or the first possible implementation manner of the first aspect, in a fourth possible implementation, the SSD controller performs a refresh operation on the flash memory of the SSD according to the determined write speed Write operations, including:

The SSD controller writes data to the flash memory in units of pages according to the determined write speed; For each page of the write data, the out-of-band OOB information of the page is recorded in the page, the OOB information including the page number of the page, and the page number of the previous page adjacent to the page in the write order The page number of the next page adjacent to the page in the write order and the time at which the data was written on the page;

Updating the expiration time queue information maintained by the SSD controller after writing data to any page in the flash memory; the expiration time queue information includes a page that was previously written and not updated, and the oldest data is written The page number of one page and the page number of the page on which the data was last written;

The SSD controller performs a refresh operation on the data written in the flash memory according to the determined data storage duration and the determined write speed, including:

The SSD controller is based on a preset refresh period, according to the page number of the page of the earliest written data in the expiration time queue information or the page number of the page of the last write data, writing in the flash memory The OOB information of the page into which the data is entered and the determined duration of the data retention, and the page that needs to perform the refresh operation;

The SSD controller performs a refresh operation on the determined page that needs to perform a refresh operation according to the determined write speed, records OOB information of the refreshed page, and updates the invalidation time queue information.

With reference to the third or fourth possible implementation manner of the first aspect, in a fifth possible implementation manner, the SSD controller is configured according to a page number of a page of the earliest written data in the expiration time queue information. The page number of the page on which the data was last written, the OOB information of the page in which the data is written in the flash memory, and the length of the data storage period, and the page that needs to perform the refresh operation, including:

The SSD controller searches for, in the flash memory, OOB information corresponding to a page of the earliest written data according to a page number of a page of the earliest written data;

Determining, by the SSD controller, whether to perform a refresh operation on a page of the earliest written data according to a time, a data saving duration, and a current time of the data written in the page included in the found OOB information;

If it is determined that it is not necessary to perform a refresh operation on the page of the earliest written data, the refresh operation of the current cycle is ended;

If it is determined that a refresh operation needs to be performed on one page of the earliest written data, the following steps are repeatedly performed until it is determined that a page that does not need to perform a refresh operation is determined or until it is determined that a page of the most recently written data needs to be executed Refresh operation:

Taking the currently determined page that needs to perform the refresh operation as the current page, and searching for the page in the flash memory according to the page number of the next page adjacent to the current page in the write order included in the OOB information of the current page. OOB information on the next page, and

Based on the found time of the data written in the next page included in the OOB information of the next page, the data storage duration and the current time, it is determined whether a refresh operation needs to be performed on the subsequent page.

With reference to the third or fourth possible implementation manner of the first aspect, in a sixth possible implementation manner, the SSD controller is configured according to a page number of a page of the earliest written data in the expiration time queue information or The page number of the page on which the data was last written, the OOB information of the page in which the data is written in the flash memory, and the length of the data storage period, and the page that needs to perform the refresh operation, including:

The SSD controller searches for, in the flash memory, OOB information corresponding to a page of the most recently written data according to a page number of a page of the most recently written data;

Determining, by the SSD controller, whether to perform a refresh operation on a page of the most recently written data according to a time, a data storage duration, and a current time of the data written in the page included in the found OOB information;

If it is determined that a refresh operation needs to be performed on a page of the most recently written data, it is determined that a refresh operation needs to be performed on all unupdated pages before the one page of the most recent write data in the write order;

If it is determined that it is not necessary to perform a refresh operation on the page of the most recently written data, the following steps are repeatedly performed until it is determined that the page requiring the refresh operation needs to be performed, and it is determined that the refresh operation needs to be performed in the determined write order. A refresh operation is performed on all pages before the page, or until it is determined that a refresh operation is not required on the page of the earliest written data:

Taking the currently determined page that does not need to perform the refresh operation as the current page, according to the page number of the previous page included in the OOB information of the current page and adjacent to the current page in the writing order, check in the flash memory Find the OOB information for the previous page, and

Whether the refresh operation of the previous page needs to be performed is determined according to the found time of the data written in the previous page included in the OOB information of the previous page, the data storage duration, and the current time.

In a second aspect, a data writing apparatus is provided, including:

a determining module for respectively performing a program/erase P/E count performed on each flash block in the flash memory of the solid state hard disk SSD, and a preset P/E number range corresponding to the write speed and the data storage duration respectively Relationship, determine the write speed and data retention time;

An execution module, configured to perform a write operation other than the refresh operation on the flash memory of the SSD according to the write speed determined by the determining module, and

Performing a refresh operation on the data written in the flash memory according to the determined data save duration and the determined write speed; the refresh operation is to write the data stored in the flash memory longer than the data save duration from the last write The location is rewritten to other locations in the flash memory.

In conjunction with the second aspect, in a first possible implementation, the execution module is specifically configured to:

After receiving the write request sent by the host, performing a write operation on the flash memory of the SSD according to the write request; or

After determining that the amount of blank flash blocks in the flash memory is below the set threshold in the flash memory, valid data in the flash block containing the invalid data is written into the blank flash page.

With reference to the second aspect, or the first possible implementation manner of the second aspect, in a second possible implementation manner, the determining module is specifically configured to:

Determining a write speed and a data retention duration corresponding to each data attribute according to a current P/E number of times performed on each flash block in the flash memory and a correspondence table corresponding to each data attribute; wherein Corresponding relationship between the preset P/E number range and the writing speed and the data saving duration is recorded in the correspondence table; the data attribute includes hot data and cold data, and the access frequency of the hot data is greater than the access of the cold data. frequency;

The execution module is specifically configured to perform the write operation according to the following steps: data attributes of data to be written into the flash memory according to the write operation except the refresh operation, from each determined data attribute In the corresponding write speed, the write speed is selected, and the write operation other than the refresh operation is performed on the flash memory of the SSD according to the selected write speed;

The execution module is specifically configured to perform the refresh operation according to the following steps: according to the data attribute of the data written in the flash memory, select a data storage duration from the determined data storage duration corresponding to each data attribute, according to the selected The data storage duration and the write speed corresponding to the cold data perform a refresh operation on the data written to the flash memory.

With reference to the second possible implementation of the second aspect, in a third possible implementation, the execution module is specifically configured to perform the write operation according to the following steps:

Writing data to the flash memory in units of pages according to the selected write speed; for each page of the write data, the out-of-band OOB information of the page is recorded in the page, the OOB information including the page of the page Number, the page number of the previous page adjacent to the page in the write order, the page number of the next page adjacent to the page in the write order, and the time at which the data is written on the page;

The execution module is specifically configured to perform the refresh operation according to the following steps:

For any data attribute, based on the preset refresh period, the page number of the page of the earliest written data or the page number of the page of the most recent write data in the expiration time queue information corresponding to the data attribute, The OOB information of the page in which the data is written in the flash memory and the selected data storage duration determine the page on which the refresh operation needs to be performed;

And performing a refresh operation on the determined page that needs to perform the refresh operation according to the write speed corresponding to the cold data, recording the OOB information of the refreshed page, and updating the invalidation time queue information corresponding to the cold data.

In conjunction with the second aspect, or the first possible implementation of the second aspect, in a fourth possible implementation, the execution module is specifically configured to perform the write operation according to the following steps:

Writing data to the flash memory in units of pages according to the determined write speed; for each page of the write data, the out-of-band OOB information of the page is recorded in the page, the OOB information including the page of the page Number, the page number of the previous page adjacent to the page in the write order, the page number of the next page adjacent to the page in the write order, and the time at which the data is written on the page;

Determining, according to the preset refresh period, a page number of a page of the earliest written data in the expiration time queue information or a page number of a page of the last write data, a page of the data written in the flash memory The OOB information and the determined data storage duration determine the page on which the refresh operation needs to be performed;

And performing a refresh operation on the determined page that needs to perform the refresh operation according to the determined write speed, recording the OOB information of the refreshed page, and updating the invalidation time queue information.

In conjunction with the third or fourth possible implementation of the second aspect, in a fifth possible implementation, the execution module is specifically configured to:

Searching, in the flash memory, OOB information corresponding to a page of the earliest written data according to a page number of a page of the earliest written data;

Determining whether it is necessary to perform a refresh operation on a page of the earliest written data according to the time when the data is written on the page, the data saving duration, and the current time included in the found OOB information;

The currently determined page that needs to perform the refresh operation is used as the current page, and is searched in the flash memory according to the page number of the next page adjacent to the current page in the write order included in the OOB information of the current page. Find the OOB information for the next page, and

In conjunction with the third or fourth possible implementation of the second aspect, in a sixth possible implementation, the executing module is specifically configured to: according to a page number of a page of the most recently written data, Searching, in the flash memory, OOB information corresponding to a page of the most recently written data;

Determining whether it is necessary to perform a refresh operation on a page of the most recently written data according to the time when the data is written on the page, the data storage duration, and the current time included in the found OOB information;

Taking the currently determined page that does not need to perform the refresh operation as the current page, searching in the flash memory according to the page number of the previous page adjacent to the current page in the writing order included in the OOB information of the current page. The OOB information of the previous page, and

In a third aspect, a data writing apparatus is provided, the apparatus comprising a processor, a memory and a bus, the memory storing execution instructions, and when the apparatus is in operation, the processor communicates with the memory via a bus, Executing the execution instruction by the processor causes the apparatus to perform the following method:

According to the current program/erase P/E times performed on each flash block in the flash memory of the solid state drive SSD, and the preset P/E number range respectively corresponding to the write speed and the data storage duration, Determine the write speed and data retention time;

Performing a write operation other than the refresh operation on the flash memory of the SSD according to the determined write speed, and

With reference to the third aspect, in a first possible implementation manner, in the method performed by the processor, performing a write operation other than a refresh operation on the flash memory of the SSD includes:

With reference to the first aspect, or the first possible implementation manner of the first aspect, in the second possible implementation manner, in the method performed by the processor, according to the current flash memory in the flash memory The average number of P/E times performed by the block and the corresponding P/E times range are respectively related to the write speed and the data storage duration, and the write speed and data retention duration are determined, including:

Performing a write operation other than the refresh operation on the flash memory of the SSD according to the determined write speed, including: data attributes of data to be written into the flash memory according to the write operation other than the refresh operation, from each determined Among the write speeds corresponding to the data attributes, the write speed is selected, and the write operation other than the refresh operation is performed on the flash memory of the SSD according to the selected write speed;

Performing a refresh operation on the data written in the flash memory according to the determined data save duration and the determined write speed, including: determining each type of data from the data attribute of the data written in the flash memory In the data storage duration corresponding to the sex, the data storage duration is selected, and the refresh operation is performed on the data written in the flash memory according to the selected data storage duration and the write speed corresponding to the cold data.

With reference to the second possible implementation of the first aspect, in a third possible implementation, the method performed by the processor performs the performing on the flash memory of the SSD according to the selected write speed. Write operations outside the refresh operation, including:

The refresh operation is performed on the data written in the flash memory according to the selected data save duration and the write speed corresponding to the cold data, including:

With reference to the first aspect, or the first possible implementation manner of the first aspect, in a fourth possible implementation, the method performed by the processor, according to the determined write speed, to the SSD Flash performs write operations other than refresh operations, including:

Writing data to the flash memory in units of pages according to the determined write speed; for writing data Each page, the out-of-band OOB information of the page is recorded in the page, the OOB information including the page number of the page, the page number of the previous page adjacent to the page in the writing order, and the page The page number of the next page adjacent in the write order and the time at which the data is written on the page;

Performing a refresh operation on the data written to the flash memory according to the determined data save duration and the determined write speed, including:

With reference to the third or fourth possible implementation manner of the first aspect, in a fifth possible implementation manner, in the method performed by the processor, according to the earliest written data in the expiration time queue information The page number of one page and the page number of the page on which the data was last written, the OOB information of the page in which the data is written in the flash memory, and the data storage duration determine the page on which the refresh operation needs to be performed, including:

With reference to the third or fourth possible implementation manner of the third aspect, in the sixth possible implementation manner, in the method performed by the processor, according to the earliest written data in the expiration time queue information The page number of one page or the page number of the page on which the data was last written, the OOB information of the page in which the data is written in the flash memory, and the length of the data storage period, and the page that needs to perform the refresh operation, including:

Searching, in the flash memory, OOB information corresponding to a page of the most recently written data according to a page number of a page of the most recently written data;

DRAWINGS

FIG. 1(a) is a schematic diagram showing a threshold voltage distribution corresponding to each MLC data at a program voltage ΔVpp1;

1(b) is a schematic diagram showing a threshold voltage distribution corresponding to each MLC data at a program voltage ΔVpp2;

2 is a schematic diagram showing changes in threshold voltage caused by electron loss;

3 is a schematic structural view of an SSD;

4 is a flowchart of a data writing method according to Embodiment 1 of the present invention;

FIG. 5 is a flowchart of a data writing method according to Embodiment 2 of the present invention;

Figure 6 (a) is a correspondence diagram at the beginning of the life of the SSD flash memory;

Figure 6 (b) is a corresponding relationship diagram in the middle of the life of the SSD flash memory;

Figure 6 (c) is a correspondence diagram at the end of the life of the SSD flash memory;

FIG. 7 is a flowchart of a data writing method according to Embodiment 3 of the present invention;

8 is a schematic diagram of recording OOB information of a page for each page of data written in a flash block;

9 is a flowchart of a data writing method according to Embodiment 4 of the present invention;

10 is a schematic structural diagram of a data writing apparatus according to Embodiment 5 of the present invention;

FIG. 11 is a schematic structural diagram of a data writing apparatus according to Embodiment 6 of the present invention.

detailed description

As shown in FIG. 3, it is a schematic structural diagram of an SSD. The SSD is mainly composed of a host logical interface 31, an SSD controller 32, and a flash chip 33. The SSD controller 32 performs data interaction with the host 34 through the host logical interface 31. After the host 34 sends a data read/write request to the SSD controller 32, the SSD controller 32 reads and writes the flash chip 33 according to the data read and write request. operating. The embodiment of the invention mainly improves the write operation of the SSD controller to the SSD flash memory in the SSD.

In the embodiment of the present invention, the SSD controller is flat according to each flash block in the flash memory of the current SSD. The P/E times that are executed, and the preset P/E times range are respectively related to the write speed and the data storage duration, and the write speed and the data storage duration are determined. With the embodiment of the present invention, different write speeds and data retention durations can be used in different life stages of the SSD flash memory to meet the requirements for the performance and life of the SSD at different stages. The data retention time here is the time base for the refresh operation. The refresh operation is to rewrite the data stored in the flash memory for more than the data storage duration from the last written position to other locations in the flash memory, which can further reduce the error rate and error degree of the stored data, and prolong the operation. The life of the SSD flash memory.

The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

As shown in FIG. 4, a flowchart of a data writing method provided by Embodiment 1 of the present invention includes the following steps:

S401: The SSD controller determines the write speed according to the average P/E times of each flash block currently executed in the flash memory of the SSD, and the preset P/E number range respectively, corresponding to the write speed and the data storage duration. Data retention time;

In this step, the SSD controller may perform a P/E operation on the flash memory in total or the most recent time after performing a P/E operation on each flash block in the flash memory of the SSD. The average number of P/Es performed on each flash block in the flash at a time determines the average number of P/Es currently performed on each flash block in the flash.

In a specific implementation, the correspondence between the different P/E frequency ranges and the write speed and the data storage duration is set in advance, and the P/E number of times of the P/E times that are currently performed on each flash block in the flash memory is determined. After the change occurs, the current write speed and the data storage duration are updated according to the correspondence between the preset P/E frequency range and the write speed and the data storage duration. Since the number of P/Es that have been executed is small in the early life of the SSD flash memory, the damage of the flash insulation layer is small, the electron loss rate in the memory cell is slow, and the stored data is not prone to errors, so in the SSD flash memory At the beginning of life, a larger write speed can be used to improve the performance of the SSD. At the same time, a longer data storage duration can be used to reduce the number of refresh operations, thereby saving SSD system overhead and improving the performance of the SSD. Correspondingly, at the end of the life of the SSD flash, the number of P/Es that have been executed is high, and the flash memory The insulation layer is damaged to a large extent, the electron loss rate in the memory unit is fast, and the storage data is prone to error. Therefore, a small write speed can be used later in the life of the SSD flash memory to extend the service life of the SSD flash memory; The short data storage duration is used to shorten the time for performing the refresh operation, and to avoid the end of the life of the SSD flash memory due to the error of the stored data exceeding the ECC check range.

S402: The SSD controller performs a write operation other than the refresh operation on the flash memory of the SSD according to the determined write speed, and performs execution on the data written in the flash memory according to the determined data save duration and the determined write speed. a refresh operation; the refresh operation is to rewrite data in the flash memory whose storage time exceeds the data storage duration from the last written location to another location in the flash memory.

In this step, the SSD controller performs a write operation other than the refresh operation according to the write speed of the current stage determined in step S401, and determines the data save duration and the write speed in conjunction with step S401 to perform a refresh operation. Here, the write operation other than the refresh operation, that is, any other write operation performed on the flash memory other than the refresh operation. For example, the specific two types of write operations can be included:

The SSD controller writes valid data in the flash block containing invalid data to the blank flash page after determining that the amount of blank flash blocks in the flash memory is lower than the set threshold in the flash memory.

The first of the above two write operations is that the SSD controller performs a write operation on the flash memory according to a write request sent by the host. The second is the process by which the SSD controller performs Garbage Collection (GC). The amount of blank flash blocks in the SSD flash memory in the flash memory is lower than the set threshold, which will seriously affect the write performance of the SSD. Therefore, it is necessary to perform an erase operation on the flash block containing invalid data in time. Here, when the data in the flash memory is modified, the data before the modification is not deleted, but the flash page including the data before the modification is marked as an invalid data page, and the modified data is written into the blank flash page. In order to perform an erase operation on a flash block containing invalid data in time, it is first necessary to move the valid data in the flash block to another location, and then perform an erase operation on the flash block containing only invalid data, which is the process of executing the GC. .

With the above embodiment, different write speeds and data retention durations can be used in different life stages of the SSD flash memory. For example, in the early life of the SSD flash memory, a larger write speed and a longer data retention duration can be used to improve the SSD. Performance; a small write speed and a short data retention time can be used later in the life of the SSD flash to extend the life of the SSD flash. It can be seen that the embodiment of the present invention can better improve the contradiction between the service life of the SSD flash memory and the performance of the SSD.

The data stored in the flash memory of the SSD can be divided into two types, one is hot data with a relatively high frequency of access, and the other is cold data with a small frequency of access. In a specific implementation, the two types of data can be treated differently, that is, different write speeds and data retention durations are used for different types of data in the same life stage of the SSD flash memory. For example, because cold data is not frequently accessed, at the end of the life of the SSD flash, compared to hot data, cold data can be used with relatively slow write speeds and relatively long data retention times. Thus, although the writing speed for cold data is slow, the threshold voltage interval between the storage units of the cold data can be made larger, so that even with a longer data storage time, the cold data is not prone to error. Since cold data is not frequently accessed, slower write speeds for cold data have less impact on the overall write performance of the SSD, and do not substantially affect user experience. This embodiment will be described in detail in the following second embodiment.

As shown in FIG. 5, a flowchart of a data writing method provided by Embodiment 2 of the present invention includes the following steps:

S501: The SSD controller determines, according to the current P/E times that are performed on each flash block in the flash memory, and the corresponding relationship table corresponding to each data attribute, determining a write speed and a data storage duration corresponding to each data attribute. Wherein, the corresponding relationship table records a correspondence between a preset P/E number of times range and a writing speed and a data saving duration; the data attribute includes hot data and cold data, and the access frequency of the hot data is greater than The frequency of access to the cold data.

In this step, different correspondence tables are set for the hot data and the cold data, respectively, and the correspondence table may be stored in a read-only memory (ROM) of the SSD controller. In the specific implementation, as the number of P/E times increases, the writing speed for cold data and hot data can be gradually reduced. As shown in FIG. 6(a), it is a correspondence diagram at the beginning of the life of the SSD flash memory. At the beginning of the life of the SSD flash memory, since the number of P/Es that have been executed is small, a large write speed and a long data retention time can be set for both hot data and cold data to improve the performance of the SSD. As shown in FIG. 6(b), it is a correspondence diagram in the middle of the life of the SSD flash memory, in which the solid line corresponds to the hot data and the broken line corresponds to the cold data. In the middle of the life of SSD flash, different correspondences can be set for hot data and cold data. Since cold data is accessed less frequently, cold data can be used with relatively slower write speeds and relatively longer data retention times than hot data. Although the cold data corresponds to a slower write speed, the threshold voltage interval between the cold data storage units can be made larger, so that cold data is not prone to errors even with a long data retention time. Moreover, since cold data is not frequently accessed, the slower write speed corresponding to cold data has less impact on the overall write performance of the SSD. At the beginning of the life of the SSD flash memory, the write speed and data retention time corresponding to the hot data can be reduced. However, due to the high frequency of access to the hot data, relatively fast write speeds and relatively short data save times can be used for hot data compared to cold data. As shown in FIG. 6(c), it is a correspondence diagram at the end of the life of the SSD flash memory, in which the solid line corresponds to the hot data and the broken line corresponds to the cold data. At the end of the life of SSD flash, the life of SSD flash is called a key consideration. In the middle of the life of the SSD flash memory, the write speed corresponding to the cold data and the hot data is further reduced, and the data retention time of the hot data can be further reduced. Table 1 and Table 2 below show the correspondence table between the hot data and the cold data in the second embodiment of the present invention. In this table, the size of the write voltage is used to identify the size of the write speed. It should be noted that the corresponding relationship table is only one of the specific implementation manners of the embodiment of the present invention. In a specific implementation, the corresponding relationship in the table may be changed according to actual needs.

Table I

Table II

S502: the SSD controller selects a write speed according to a data attribute of data to be written into the flash memory according to the write operation except the refresh operation, and selects a write speed from the determined write speed corresponding to each data attribute. The flash memory of the SSD performs the write operation.

In this step, the data attributes of different types of data can be set in advance. For example, the root directory of the file can be set to hot data because it needs to be accessed frequently. For some video files, it can be set as cold data. Here, the data attribute of the data is not fixed. After the data is written to the flash memory, the SSD controller can adjust the data attribute according to the accessed frequency of the data.

S503: The SSD controller selects a data storage duration from the determined data storage duration corresponding to each data attribute determined according to the data attribute of the data written in the flash memory, and saves the duration according to the selected data and the corresponding data of the cold data. Speed, performs a refresh operation on the data written to the flash memory.

In this step, if the hot data written in the flash memory is not updated after the set data is saved for a long time, the data attribute of the hot data can be changed to cold data, and the write speed corresponding to the cold data is used. Refresh the data. Therefore, in this step, whether it is hot data or cold data, when refresh is required, it is refreshed as cold data.

When the refresh operation is performed, the flash block can be used as the minimum refresh unit. However, since the time of writing each page of the flash block is inconsistent, if the data is refreshed according to the data written at the earliest time, many unnecessary data will be refreshed. If the data is refreshed according to the data that is written the latest, it may cause other data that was written earlier to be incorrectly updated due to not being refreshed in time. Therefore, in the following Embodiment 3 of the present invention, in order to improve the timeliness of performing data refreshing and avoiding refreshing operations on unnecessary data, the page is used as the minimum refresh unit.

As shown in FIG. 7, a flowchart of a data writing method provided by Embodiment 3 of the present invention includes:

S701: The SSD controller performs an average of the P/E times performed on each flash block in the flash memory of the SSD, and the preset P/E times range respectively corresponding to the write speed and the data storage duration. System, determine the write speed and data retention time.

For the implementation of this step, refer to the description of Embodiment 1, and where it is repeated, it will not be described again.

S702: the SSD controller writes data to the flash memory in units of pages according to the determined write speed; and records out-of-band (OOB) information of the page in the page for each page of the write data, The OOB information includes a page number of the page, a page number of a previous page adjacent to the page in the writing order, a page number of a subsequent page adjacent to the page in the writing order, and a page number on the page The time the data was written.

As shown in FIG. 8, a schematic diagram of OOB information of the page is recorded for each page in which data is written in the flash block. Through the OOB information of any page of data, not only the page number of the page can be determined, but also the page number of the previous page of the page and the page number of the next page of the page, the previous page and the next page here A page is a page that is adjacent to the page in the write order.

S703: The SSD controller updates the expiration time queue information maintained by the SSD controller after writing data to any page in the flash memory; the invalidation time queue information includes the previously written data and is not updated, the earliest The page number of the page on which the data is written and the page number of the page on which the data was last written.

In this step, the expiration time queue information can be stored in the ROM of the SSD controller. Each time the SSD controller performs a write operation, the data written by the write operation is added to the expiration time queue. Here, adding the written data to the expiration time queue is actually recording the written page as described in step S702. OOB information. After the written data is added to the dead time queue, the dead time queue information is updated. In the expiration time queue information, only the page header of the queue head of the expiration time queue and the page number of the tail of the queue are recorded, wherein the page of the queue header may be a page of the earliest written data, and the page at the end of the queue may be the The page on which data was last written, or the page of the queue header may be one page of the most recently written data, and the page at the end of the queue may be one page of the earliest written data. Combining the page number of the queue header or the tail of the queue, and the OOB information of each page recorded (including the page number of the page, the page number of the previous page and the next page of the page), the expiration time can be found in turn. Every page in the queue.

S704: The SSD controller is based on a preset refresh period, according to the page number of the page of the earliest written data in the expiration time queue information and the page number of the page of the last write data, the flash memory. The OOB information of the page in which the data is written and the duration of the data storage, determining that a refresh needs to be performed a page of operation; performing a refresh operation on the determined page that needs to perform a refresh operation according to the determined write speed, recording the OOB information of the refreshed page, and updating the invalidation time queue information.

According to the description of the above steps, the page number of the page in which the data is first written or the page number of the page on which the data was last written and the OOB information of the page in which the data is written in the flash memory may be sequentially determined according to the failure time queue information. Find each page in the expiration time queue. In combination with the data storage duration, it is sequentially determined whether each page found needs to be refreshed, and after determining that it needs to be refreshed, it is refreshed according to the determined write speed, because the refresh actually rewrites the data of the page to other The position of the page, therefore, the OOB information of the refreshed page needs to be re-recorded, and the dead time queue information is updated.

When determining a page that needs to perform a refresh operation, a page of the earliest written data or a page of the last written data may be selected from the above-mentioned dead time queue information as a start page to start judgment, according to the selected start page. Differently, the following two embodiments are specifically provided in this embodiment.

The first type: starting with a page of the earliest written data as a starting page;

Specifically, the SSD controller searches for, in the flash memory, OOB information corresponding to one page of the earliest written data according to a page number of a page of the earliest written data;

Taking the currently determined page that needs to perform the refresh operation as the current page, and searching for the page in the flash memory according to the page number of the next page adjacent to the current page in the write order included in the OOB information of the current page. The OOB information of the next page, and according to the found time of the data written in the next page included in the OOB information of the next page, the data storage duration and the current time, whether it is necessary to One page performs a refresh operation.

For example, the expiration time queue information records the page number 2 of one page of the earliest written data and the page number 6 of the page of the most recently written data. Find the page with page number 2 based on the OOB information for each page in the flash. After finding the page with the page number 2, according to the time when the data is written on the page recorded in the OOB information of the page, the data storage duration, and the current time, the time and current time of writing the data on the page are determined. Whether the time interval between times exceeds the data retention time. If it is exceeded, it is determined that a refresh operation needs to be performed on the page number 2, otherwise, the current refresh operation is ended. If it is determined that a refresh operation is required for the page number 2, a refresh operation is performed on the page number 2, and the next page of the page is recorded according to the OOB information of the page number 2 Page number 4, find the page number 4 in the flash memory. After finding the page with page number 4, according to the time when the data is written on the page recorded in the OOB information of the page, the data storage duration, and the current time, the time and current time of writing the data on the page are determined. Whether the time interval between times exceeds the data retention time. If it is exceeded, it is determined that a refresh operation needs to be performed on the page number 4, otherwise, the current refresh operation is ended. If it is determined that a refresh operation is required on the page number 4, the page operation is performed on the page number 4, and the next page of the page recorded in the OOB information of the page having the page number 4 is Page number 6, find the page number 6 in the flash memory. After finding the page with page number 6, according to the time of writing data on the page recorded in the OOB information of the page, the data storage duration, and the current time, determining the time and current time of writing data on the page Whether the time interval between times exceeds the data retention time. If it is exceeded, it is determined that a refresh operation needs to be performed on the page number 6; otherwise, the current refresh operation is ended. If it is determined that a refresh operation is required for the page number 6 of the page, the page operation is performed on the page number 6 and since page number 6 is the page number of the page of the most recent write data, Need to end the current refresh operation.

The second type: starting with the page of the last written data as the starting page;

Specifically, the SSD controller determines, according to the page number of the page of the earliest written data in the expiration time queue information or the page number of the page on which the data was last written, the OOB of the page in which the data is written in the flash memory. The information and the length of time the data is saved determine the pages that need to perform the refresh operation, including:

If it is determined that a refresh operation needs to be performed on a page of the most recently written data, it is determined that a refresh operation is required to be performed on all pages before the page of the most recent write data in the write order;

If it is determined that it is not necessary to perform a refresh operation on the page of the most recently written data, the following steps are repeatedly performed until it is determined that the page requiring the refresh operation needs to be performed, and it is determined that the refresh operation needs to be performed in the determined write order. All unupdated pages before the page are refreshed, or until it is determined that a refresh operation is not required on the page of the earliest written data:

Taking the currently determined page that does not need to perform the refresh operation as the current page, searching in the flash memory according to the page number of the previous page adjacent to the current page in the writing order included in the OOB information of the current page. The OOB information of the previous page, and according to the found time of the data written in the previous page included in the OOB information of the previous page, the data storage duration and the current time, it is determined whether the previous one needs to be The page performs a refresh operation.

For example, the expiration time queue information records the page number 2 of one page of the earliest written data and the page number 6 of the page of the most recently written data. Find the page number 6 based on the OOB information for each page in the flash. After finding the page with page number 6, according to the time of writing data on the page recorded in the OOB information of the page, the data storage duration, and the current time, determining the time and current time of writing data on the page Whether the time interval between times exceeds the data retention time. If it is exceeded, it is determined that a refresh operation is required for the page numbered 6 and all unupdated pages whose write order precedes the page number. Here, it is determined that the previous page of the page number 6 is the page with the page number 4 according to the OOB information of the page number 6 of the page, and the page number is determined according to the OOB information of the page whose page number is 4. The previous page of the page is a page with page number 2, that is, one page of the earliest data to be written. Then, in this embodiment, it is necessary to sequentially refresh the pages of

page numbers

6, 4, and 2. If it is determined that the page number is The time interval between the time when the page write data of 6 and the current time does not exceed the data storage time length, and the page number 4 of the previous page of the page recorded in the OOB information of the page whose page number is 6 is Look for pages with page number 4 in flash memory. After finding the page with page number 4, according to the time when the data is written on the page recorded in the OOB information of the page, the data storage duration, and the current time, the time and current time of writing the data on the page are determined. Whether the time interval between times exceeds the data retention time. If it is exceeded, it is determined that the page needs to be refreshed for the page numbered 4 and the previous page of the page number 4 (page number 2). Otherwise, according to the page number 2 of the previous page of the page recorded in the OOB information of the page number 4, the page number 2 is found in the flash memory, and after the page number 2 is found, according to the page number The time at which the data is written on the page recorded in the OOB information of the page, the length of the data being saved, and the current time, determining whether the time interval between the time when the page is written with the current time and the current time exceeds the data saving The duration, if exceeded, determines that a refresh operation needs to be performed on the page with page number 2, otherwise, it is determined that the page with the page number 2 is not required, that is, the page of the earliest written data performs a refresh operation.

With the second embodiment and the third embodiment described above, the following fourth embodiment is proposed. In the fourth embodiment, different data attributes correspond to different correspondence tables, and when data refresh is performed, the page is used as the minimum refresh unit. The details of the specific implementations of the above embodiments are not described again.

As shown in FIG. 9, a flowchart of a data writing method provided by Embodiment 4 of the present invention includes:

S901: The SSD controller determines to write according to the P/E times that are currently performed on each flash block in the flash memory of the SSD, and the preset P/E number range respectively, and the correspondence between the write speed and the data storage duration. Speed and data retention time.

S902: the SSD controller writes data to the flash memory in units of pages according to the selected write speed; for each page of the write data, records the out-of-band OOB information of the page in the page, The OOB information includes the page number of the page, the page number of the previous page adjacent to the page in the write order, the page number of the next page adjacent to the page in the write order, and the page number written on the page The time of the data.

S903: After writing data to any page in the flash memory, the SSD controller updates the invalidation time queue letter corresponding to the data attribute maintained by the SSD controller according to the data attribute of the written data. The expiration time queue information includes a page number of a page of the earliest data to be written and a page number of a page of which data was last written, in a page that was previously written with data of the data attribute and not updated.

S904: For any data attribute, the SSD controller is based on a preset refresh period, according to the page number of the earliest written data in the expiration time queue information corresponding to the data attribute or the last write data. The page number of one page, the OOB information of the page in which the data is written in the flash memory, and the selected data storage duration, determine a page that needs to perform a refresh operation; perform a refresh on the determined need according to the write speed corresponding to the cold data The operated page performs a refresh operation, records the OOB information of the refreshed page, and updates the invalidation time queue information corresponding to the cold data.

Specifically, for any data attribute, the SSD controller searches for, in the flash memory, OOB information corresponding to a page of the earliest written data according to a page number of a page of the earliest written data;

Determining, by the SSD controller, whether to perform a refresh operation on a page of the earliest written data according to the time of writing data on the page included in the found OOB information, the selected data saving duration, and the current time;

Taking the currently determined page that needs to perform the refresh operation as the current page, and searching for the page in the flash memory according to the page number of the next page adjacent to the current page in the write order included in the OOB information of the current page. The OOB information of the next page, and according to the found time of the data written in the next page included in the OOB information of the next page, the selected data storage duration and the current time, whether it is necessary to The next page performs a refresh operation.

Specifically, for any one of the data attributes, the SSD controller is based on a preset refresh period, according to the page number of the page of the most recent write data in the expiration time queue information corresponding to the data attribute, the flash memory. The OOB information of the page in which the data is written and the length of time the selected data is saved, and the page that needs to perform the refresh operation, including:

For any data attribute, the SSD controller searches for the OOB information corresponding to the page of the most recently written data in the flash memory according to the page number of the page of the most recently written data;

Determining, by the SSD controller, whether to perform a refresh operation on a page of the most recently written data according to the time of writing data on the page, the selected data storage duration, and the current time included in the found OOB information;

Whether the refresh operation of the previous page needs to be performed is determined according to the time of writing the data on the previous page, the selected data save duration, and the current time included in the found OOB information of the previous page.

Based on the same inventive concept, the embodiment of the present invention further provides a data writing device corresponding to the data writing method. Since the principle of solving the problem is similar to the data writing method of the embodiment of the present invention, the implementation of the device is implemented. See the implementation of the method, and the repetition will not be repeated.

FIG. 10 is a schematic structural diagram of a data writing apparatus according to Embodiment 5 of the present invention, including:

The determining module 101 is configured to perform an average of the program/erase P/E times performed on each flash block in the flash memory of the solid state hard disk SSD, and the preset P/E number of times range respectively with the writing speed and the data saving duration Corresponding relationship, determining the writing speed and the data storage duration;

The executing module 102 is configured to perform a write operation other than the refresh operation on the flash memory of the SSD according to the write speed determined by the determining module 101, and

Optionally, the execution module 102 is specifically configured to:

Optionally, the determining module 101 is specifically configured to:

The execution module 102 is specifically configured to perform the write operation according to the following steps: the data attribute of the data that needs to be written into the flash memory according to the write operation other than the refresh operation, and the corresponding write from each determined data attribute In the speed, the write speed is selected, and the write operation other than the refresh operation is performed on the flash memory of the SSD according to the selected write speed;

The execution module 102 is specifically configured to perform the refresh operation according to the following steps: according to the data attribute of the data written in the flash memory, select a data storage duration from the determined data storage duration corresponding to each data attribute, according to the selection Data save duration and write speed corresponding to cold data, write to Perform a refresh operation on the data in the flash memory.

Optionally, the execution module 102 is specifically configured to perform the write operation according to the following steps:

The execution module 102 is specifically configured to perform the refresh operation according to the following steps:

Optionally, the execution module 102 is specifically configured to:

Optionally, the executing module 102 is specifically configured to: in the flash memory, search for OOB information corresponding to a page of the most recently written data according to a page number of a page of the most recently written data;

FIG. 11 is a schematic structural diagram of a data writing apparatus 110 according to Embodiment 6 of the present invention. The apparatus includes a processor 111, a memory 112, and a bus 113. The memory 112 stores execution instructions. When the apparatus is running, The processor 111 communicates with the memory 112 via a bus 113, and the processor 111 executes the execution instructions such that the apparatus performs the following method:

The write speed is determined according to the current program/erase P/E times performed on each flash block in the flash memory of the solid state drive SSD, and the preset P/E number range respectively corresponding to the write speed and the data save duration. And the length of time the data is saved;

Optionally, in the method performed by the processor 111, performing a write operation other than the refresh operation on the flash memory of the SSD includes:

After receiving the write request sent by the host, executing the flash memory of the SSD according to the write request Write operation; or,

Optionally, in the method performed by the processor 111, according to the current P/E times performed on each flash block in the flash memory, and the preset P/E times range and the write speed respectively The correspondence between data retention durations, determining the write speed and data retention duration, including:

Performing a refresh operation on the data written in the flash memory according to the determined data save duration and the determined write speed, including: saving the data duration corresponding to each of the determined data attributes according to the data attribute of the data written in the flash memory In the middle, the data storage duration is selected, and a refresh operation is performed on the data written in the flash memory according to the selected data storage duration and the write speed corresponding to the cold data.

Optionally, in the method performed by the processor 111, performing a write operation other than the refresh operation on the flash memory of the SSD according to the selected write speed, including:

After writing data to any page in the flash memory, updating according to the data attribute of the written data The expiration time queue information corresponding to the data attribute maintained by the SSD controller; the failure time queue information includes a page number of the page of the first written data and the most recent page that was previously written to the data having the data attribute and not updated. The page number of a page at which data is written at a time;

Optionally, in the method performed by the processor 111, performing a write operation other than the refresh operation on the flash memory of the SSD according to the determined write speed, including:

After writing data to any page in the flash memory, updating the expiration time queue information maintained by the SSD controller; the dead time queue information includes one of the pages that were previously written and not updated, and the first one of which is written The page number of the page and the page number of the page on which the data was last written;

Optionally, in the method performed by the processor 111, according to the page number of the page of the earliest written data in the expiration time queue information and the page number of the page of the last written data, the flash memory The OOB information of the page in which the data is written and the length of time the data is saved, and the page that needs to perform the refresh operation, including:

Optionally, in the method performed by the processor 111, according to a page number of a page of the earliest written data in the expiration time queue information or a page number of a page of the last write data, the flash memory The OOB information of the page in which the data is written and the length of time the data is saved, and the page that needs to perform the refresh operation, including:

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, the invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) including computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of a method, apparatus (system), and computer program product according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Implemented in flowchart one Means of a process or a plurality of processes and/or block diagrams of a function specified in a block or blocks.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

While the preferred embodiment of the invention has been described, it will be understood that Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and the modifications and

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

Claims

A data writing method, comprising:

The SSD controller corresponds to the average of the program/erase P/E times currently performed for each flash block in the flash memory of the SSD, and the preset P/E number range respectively, corresponding to the write speed and the data storage duration. Relationship, determine the write speed and data retention time;

The SSD controller performs a write operation other than the refresh operation on the flash memory of the SSD according to the determined write speed, and

Performing a refresh operation on the data written in the flash memory according to the determined data save duration and the determined write speed; the refresh operation is to write the data stored in the flash memory longer than the data save duration from the last write The location is rewritten to other locations in the flash memory.
The method of claim 1, wherein the SSD controller performs a write operation other than a refresh operation on the flash memory of the SSD, including:

After receiving the write request sent by the host, the SSD controller performs a write operation on the flash memory of the SSD according to the write request; or

The SSD controller writes valid data in the flash block containing the invalid data into the blank flash page after determining that the ratio of the number of blank flash blocks in the flash memory in the flash memory is lower than a set threshold.
The method according to claim 1 or 2, wherein the SSD controller separately performs an average of P/E times performed on each of the flash blocks in the flash memory, and a preset P/E number of times respectively Determine the write speed and data retention duration, as well as the write speed and data retention duration, including:

Determining, by the SSD controller, a write speed and a data retention duration corresponding to each data attribute according to a current P/E number of times performed on each flash block in the flash memory and a correspondence table corresponding to each data attribute. Wherein, the corresponding relationship table records a correspondence between a preset P/E number of times range and a writing speed and a data saving duration; the data attribute includes hot data and cold data, and the access frequency of the hot data is greater than The frequency of access to the cold data;

The SSD controller performs a write operation other than the refresh operation on the flash memory of the SSD according to the determined write speed, including: the SSD controller needs to write to the flash memory according to the write operation other than the refresh operation Data attribute of the data, selecting a write speed from the determined write speed corresponding to each data attribute, and performing a write operation other than the refresh operation on the flash memory of the SSD according to the selected write speed;

The SSD controller performs a refresh operation on the data written in the flash memory according to the determined data save duration and the determined write speed, including: the SSD controller determines from the data attribute of the data written in the flash memory In the data storage duration corresponding to each data attribute, the data storage duration is selected, and the refresh operation is performed on the data written in the flash memory according to the selected data storage duration and the write speed corresponding to the cold data.
The method of claim 3, wherein the SSD controller performs the write operation other than the refresh operation on the flash memory of the SSD according to the selected write speed, including:

The SSD controller writes data to the flash memory in units of pages according to the selected write speed; for each page of the write data, the out-of-band OOB information of the page is recorded in the page, the OOB information The page number including the page, the page number of the previous page adjacent to the page in the write order, the page number of the next page adjacent to the page in the write order, and the data written on the page Time; and

After writing data to any page in the flash memory, updating the expiration time queue information corresponding to the data attribute maintained by the SSD controller according to the data attribute of the written data; the expiration time queue information includes The page number of the page in which the data with the data attribute is written and not updated, the page number of the page on which the data was first written, and the page number of the page on which the data was last written;

The SSD controller performs a refresh operation on the data written in the flash memory according to the selected data save duration and the write speed corresponding to the cold data, including:

For any data attribute, the SSD controller is based on a preset refresh period, according to the page number of the page of the earliest written data or the last write data in the expiration time queue information corresponding to the data attribute. The page number of the page, the OOB information of the page in which the data is written in the flash memory, and the selected data storage duration, and the page that needs to perform the refresh operation is determined;

The SSD controller performs a refresh operation on the determined page that needs to perform the refresh operation according to the write speed corresponding to the cold data, records the OOB information of the refreshed page, and updates the invalidation time queue information corresponding to the cold data.
The method according to claim 1 or 2, wherein the SSD controller performs a write operation other than the refresh operation on the flash memory of the SSD according to the determined write speed, including:

The SSD controller writes data to the flash memory in units of pages according to the determined write speed; for each page of the write data, the out-of-band OOB information of the page is recorded in the page, the OOB information The page number including the page, the page number of the previous page adjacent to the page in the write order, the page number of the next page adjacent to the page in the write order, and the data written on the page Time; and

Updating the expiration time queue information maintained by the SSD controller after writing data to any page in the flash memory; the expiration time queue information includes a page that was previously written and not updated, and the oldest data is written The page number of one page and the page number of the page on which the data was last written;

The SSD controller performs a refresh operation on the data written in the flash memory according to the determined data storage duration and the determined write speed, including:

The SSD controller is based on a preset refresh period, according to the page number of the page of the earliest written data in the expiration time queue information or the page number of the page of the last write data, writing in the flash memory The OOB information of the page into which the data is entered and the determined duration of the data retention, and the page that needs to perform the refresh operation;

The SSD controller performs a refresh operation on the determined page that needs to perform a refresh operation according to the determined write speed, records OOB information of the refreshed page, and updates the invalidation time queue information.
The method according to claim 4 or 5, wherein said SSD controller determines a page number of a page of said earliest written data and a page number of a page of which data was last written based on the expiration time queue information The OOB information of the page in which the data is written in the flash memory and the length of the data storage period, and the page that needs to perform the refresh operation, including:

The SSD controller checks in the flash memory according to a page number of a page of the earliest written data Finding OOB information corresponding to a page of the earliest written data;

Determining, by the SSD controller, whether to perform a refresh operation on a page of the earliest written data according to a time, a data saving duration, and a current time of the data written in the page included in the found OOB information;

If it is determined that it is not necessary to perform a refresh operation on the page of the earliest written data, the refresh operation of the current cycle is ended;

If it is determined that a refresh operation needs to be performed on one page of the earliest written data, the following steps are repeatedly performed until it is determined that a page that does not need to perform a refresh operation is determined or until it is determined that a page of the most recently written data needs to be executed Refresh operation:

Taking the currently determined page that needs to perform the refresh operation as the current page, and searching for the page in the flash memory according to the page number of the next page adjacent to the current page in the write order included in the OOB information of the current page. OOB information on the next page, and

Based on the found time of the data written in the next page included in the OOB information of the next page, the data storage duration and the current time, it is determined whether a refresh operation needs to be performed on the subsequent page.
The method according to claim 4 or 5, wherein said SSD controller determines a page number of a page of said earliest written data or a page number of a page of which data was last written based on the expiration time queue information The OOB information of the page in which the data is written in the flash memory and the length of the data storage period, and the page that needs to perform the refresh operation, including:

The SSD controller searches for, in the flash memory, OOB information corresponding to a page of the most recently written data according to a page number of a page of the most recently written data;

Determining, by the SSD controller, whether to perform a refresh operation on a page of the most recently written data according to a time, a data storage duration, and a current time of the data written in the page included in the found OOB information;

If it is determined that a refresh operation needs to be performed on a page of the most recently written data, it is determined that a refresh operation needs to be performed on all unupdated pages before the one page of the most recent write data in the write order;

If it is determined that it is not necessary to perform a refresh operation on the page of the most recently written data, the following steps are repeatedly performed until it is determined that the page requiring the refresh operation needs to be performed, and it is determined that the refresh operation needs to be performed in the determined write order. A refresh operation is performed on all pages before the page, or until it is determined that a refresh operation is not required on the page of the earliest written data:

Taking the currently determined page that does not need to perform the refresh operation as the current page, searching in the flash memory according to the page number of the previous page adjacent to the current page in the writing order included in the OOB information of the current page. The OOB information of the previous page, and

Whether the refresh operation of the previous page needs to be performed is determined according to the found time of the data written in the previous page included in the OOB information of the previous page, the data storage duration, and the current time.
A data writing device, comprising:

a determining module for respectively performing a program/erase P/E count performed on each flash block in the flash memory of the solid state hard disk SSD, and a preset P/E number range corresponding to the write speed and the data storage duration respectively Relationship, determine the write speed and data retention time;

An execution module, configured to perform a write operation other than the refresh operation on the flash memory of the SSD according to the write speed determined by the determining module, and

Performing a refresh operation on the data written in the flash memory according to the determined data save duration and the determined write speed; the refresh operation is to write the data stored in the flash memory longer than the data save duration from the last write The location is rewritten to other locations in the flash memory.
The apparatus according to claim 8, wherein the execution module is specifically configured to:

After receiving the write request sent by the host, performing a write operation on the flash memory of the SSD according to the write request; or

After determining that the amount of blank flash blocks in the flash memory is below the set threshold in the flash memory, valid data in the flash block containing the invalid data is written into the blank flash page.
The device according to claim 8 or 9, wherein the determining module is specifically configured to:

Determining a write speed and a data retention duration corresponding to each data attribute according to a current P/E number of times performed on each flash block in the flash memory and a correspondence table corresponding to each data attribute; The corresponding relationship table records a correspondence between a preset P/E number range and a write speed and a data storage duration; the data attribute includes hot data and cold data, and the access frequency of the hot data is greater than the The frequency of access to cold data;

The execution module is specifically configured to perform the write operation according to the following steps: a data attribute of data to be written into the flash memory according to the write operation except the refresh operation, and a write speed corresponding to each determined data attribute Selecting a write speed and performing a write operation other than the refresh operation on the flash memory of the SSD according to the selected write speed;

The execution module is specifically configured to perform the refresh operation according to the following steps: according to the data attribute of the data written in the flash memory, select a data storage duration from the determined data storage duration corresponding to each data attribute, according to the selected The data storage duration and the write speed corresponding to the cold data perform a refresh operation on the data written to the flash memory.
The apparatus according to claim 10, wherein the execution module is specifically configured to perform the write operation according to the following steps:

Writing data to the flash memory in units of pages according to the selected write speed; for each page of the write data, the out-of-band OOB information of the page is recorded in the page, the OOB information including the page of the page Number, the page number of the previous page adjacent to the page in the write order, the page number of the next page adjacent to the page in the write order, and the time at which the data is written on the page;

After writing data to any page in the flash memory, updating the expiration time queue information corresponding to the data attribute maintained by the SSD controller according to the data attribute of the written data; the expiration time queue information includes The page number of the page in which the data with the data attribute is written and not updated, the page number of the page on which the data was first written, and the page number of the page on which the data was last written;

The execution module is specifically configured to perform the refresh operation according to the following steps:

For any data attribute, based on the preset refresh period, the page number of the page of the earliest written data or the page number of the page of the most recent write data in the expiration time queue information corresponding to the data attribute, The OOB information of the page in which the data is written in the flash memory and the selected data storage duration determine the page on which the refresh operation needs to be performed;

And performing a refresh operation on the determined page that needs to perform the refresh operation according to the write speed corresponding to the cold data, recording the OOB information of the refreshed page, and updating the invalidation time queue information corresponding to the cold data.
The apparatus according to claim 8 or 9, wherein the execution module is specifically configured to perform the write operation according to the following steps:

Writing data to the flash memory in units of pages according to the determined write speed; for each page of the write data, the out-of-band OOB information of the page is recorded in the page, the OOB information including the page of the page Number, the page number of the previous page adjacent to the page in the write order, the page number of the next page adjacent to the page in the write order, and the time at which the data is written on the page;

Updating the expiration time queue information maintained by the SSD controller after writing data to any page in the flash memory; the expiration time queue information includes a page that was previously written and not updated, and the oldest data is written The page number of one page and the page number of the page on which the data was last written;

The execution module is specifically configured to perform the refresh operation according to the following steps:

Determining, according to the preset refresh period, a page number of a page of the earliest written data in the expiration time queue information or a page number of a page of the last write data, a page of the data written in the flash memory The OOB information and the determined data storage duration determine the page on which the refresh operation needs to be performed;

And performing a refresh operation on the determined page that needs to perform the refresh operation according to the determined write speed, recording the OOB information of the refreshed page, and updating the invalidation time queue information.
The device according to claim 11 or 12, wherein the execution module is specifically configured to:

Searching, in the flash memory, OOB information corresponding to a page of the earliest written data according to a page number of a page of the earliest written data;

Determining whether it is necessary to perform a refresh operation on a page of the earliest written data according to the time when the data is written on the page, the data saving duration, and the current time included in the found OOB information;

If it is determined that it is not necessary to perform a refresh operation on the page of the earliest written data, the refresh operation of the current cycle is ended;

If it is determined that a refresh operation needs to be performed on one page of the earliest written data, the following steps are repeatedly performed until it is determined that a page that does not need to perform a refresh operation is determined or until it is determined that a page of the most recently written data needs to be executed Refresh operation:

Taking the currently determined page that needs to perform the refresh operation as the current page, and searching for the page in the flash memory according to the page number of the next page adjacent to the current page in the write order included in the OOB information of the current page. OOB information on the next page, and

Based on the found time of the data written in the next page included in the OOB information of the next page, the data storage duration and the current time, it is determined whether a refresh operation needs to be performed on the subsequent page.
The apparatus according to claim 11 or 12, wherein the execution module is configured to: search for the most recent write in the flash memory according to a page number of a page of the most recently written data OOB information of a page into the data;

Determining whether it is necessary to perform a refresh operation on a page of the most recently written data according to the time when the data is written on the page, the data storage duration, and the current time included in the found OOB information;

If it is determined that a refresh operation needs to be performed on a page of the most recently written data, it is determined that a refresh operation needs to be performed on all unupdated pages before the one page of the most recent write data in the write order;

If it is determined that it is not necessary to perform a refresh operation on the page of the most recently written data, the following steps are repeatedly performed until it is determined that the page requiring the refresh operation needs to be performed, and it is determined that the refresh operation needs to be performed in the determined write order. A refresh operation is performed on all pages before the page, or until it is determined that a refresh operation is not required on the page of the earliest written data:

Taking the currently determined page that does not need to perform the refresh operation as the current page, searching in the flash memory according to the page number of the previous page adjacent to the current page in the writing order included in the OOB information of the current page. The OOB information of the previous page, and

Whether the refresh operation of the previous page needs to be performed is determined according to the found time of the data written in the previous page included in the OOB information of the previous page, the data storage duration, and the current time.
A data writing device, comprising: a processor, a memory and a bus, wherein the memory stores execution instructions, and when the device is running, the processor communicates with the memory through a bus, Executing the execution instruction by the processor causes the apparatus to perform the following method:

The write speed is determined according to the current program/erase P/E times performed on each flash block in the flash memory of the solid state drive SSD, and the preset P/E number range respectively corresponding to the write speed and the data save duration. And the length of time the data is saved;

Performing a write operation other than the refresh operation on the flash memory of the SSD according to the determined write speed, and

Performing a refresh operation on the data written in the flash memory according to the determined data save duration and the determined write speed; the refresh operation is to write the data stored in the flash memory longer than the data save duration from the last write The location is rewritten to other locations in the flash memory.
The device according to claim 15, wherein in the method executed by the processor, performing a write operation other than a refresh operation on the flash memory of the SSD includes:

After receiving the write request sent by the host, performing a write operation on the flash memory of the SSD according to the write request; or

After determining that the amount of blank flash blocks in the flash memory is below the set threshold in the flash memory, valid data in the flash block containing the invalid data is written into the blank flash page.
The apparatus according to claim 15 or 16, wherein said method executed by said processor is based on a current average of P/E times performed on each of said flash blocks in said flash memory, and a preset The correspondence between the P/E frequency range and the writing speed and the data saving duration respectively determines the writing speed and the data saving duration, including:

Determining a write speed and a data retention duration corresponding to each data attribute according to a current P/E number of times performed on each flash block in the flash memory and a correspondence table corresponding to each data attribute; wherein Corresponding relationship between the preset P/E number range and the writing speed and the data saving duration is recorded in the correspondence table; the data attribute includes hot data and cold data, and the access frequency of the hot data is greater than the access of the cold data. frequency;

Performing a write operation other than the refresh operation on the flash memory of the SSD according to the determined write speed, the package Including: according to the data attribute of the data that needs to be written into the flash memory by the write operation other than the refresh operation, selecting the write speed from the determined write speed corresponding to each data attribute, and according to the selected write speed, The flash memory of the SSD performs the write operation except the refresh operation;

Performing a refresh operation on the data written in the flash memory according to the determined data save duration and the determined write speed, including: saving the data duration corresponding to each of the determined data attributes according to the data attribute of the data written in the flash memory In the middle, the data storage duration is selected, and a refresh operation is performed on the data written in the flash memory according to the selected data storage duration and the write speed corresponding to the cold data.
The device according to claim 17, wherein in the method executed by the processor, performing a write operation other than the refresh operation on the flash memory of the SSD according to the selected write speed comprises:

Writing data to the flash memory in units of pages according to the selected write speed; for each page of the write data, the out-of-band OOB information of the page is recorded in the page, the OOB information including the page of the page Number, the page number of the previous page adjacent to the page in the write order, the page number of the next page adjacent to the page in the write order, and the time at which the data is written on the page;

After writing data to any page in the flash memory, updating the expiration time queue information corresponding to the data attribute maintained by the SSD controller according to the data attribute of the written data; the expiration time queue information includes The page number of the page in which the data with the data attribute is written and not updated, the page number of the page on which the data was first written, and the page number of the page on which the data was last written;

The refresh operation is performed on the data written in the flash memory according to the selected data save duration and the write speed corresponding to the cold data, including:

For any data attribute, based on the preset refresh period, the page number of the page of the earliest written data or the page number of the page of the most recent write data in the expiration time queue information corresponding to the data attribute, The OOB information of the page in which the data is written in the flash memory and the selected data storage duration determine the page on which the refresh operation needs to be performed;

Performing a refresh operation on the determined page that needs to perform the refresh operation according to the write speed corresponding to the cold data, recording the OOB information of the refreshed page, and updating the invalidation time queue corresponding to the cold data. information.
The device according to claim 15 or 16, wherein in the method executed by the processor, performing a write operation other than the refresh operation on the flash memory of the SSD according to the determined write speed comprises:

Writing data to the flash memory in units of pages according to the determined write speed; for each page of the write data, the out-of-band OOB information of the page is recorded in the page, the OOB information including the page of the page Number, the page number of the previous page adjacent to the page in the write order, the page number of the next page adjacent to the page in the write order, and the time at which the data is written on the page;

After writing data to any page in the flash memory, updating the expiration time queue information maintained by the SSD controller; the dead time queue information includes one of the pages that were previously written and not updated, and the first one of which is written The page number of the page and the page number of the page on which the data was last written;

Performing a refresh operation on the data written to the flash memory according to the determined data save duration and the determined write speed, including:

Determining, according to the preset refresh period, a page number of a page of the earliest written data in the expiration time queue information or a page number of a page of the last write data, a page of the data written in the flash memory The OOB information and the determined data storage duration determine the page on which the refresh operation needs to be performed;

And performing a refresh operation on the determined page that needs to perform the refresh operation according to the determined write speed, recording the OOB information of the refreshed page, and updating the invalidation time queue information.
The apparatus according to claim 18 or 19, wherein in said method executed by said processor, the page number of the page of the earliest written data and the most recent write data are based on the expiration time queue information. The page number of one page, the OOB information of the page in which the data is written in the flash memory, and the length of the data storage period, and the page that needs to perform the refresh operation, including:

Searching, in the flash memory, OOB information corresponding to a page of the earliest written data according to a page number of a page of the earliest written data;

Determining whether it is necessary to perform a refresh operation on a page of the earliest written data according to the time when the data is written on the page, the data storage duration, and the current time included in the found OOB information;

If it is determined that it is not necessary to perform a refresh operation on the page of the earliest written data, the refresh operation of the current cycle is ended;

If it is determined that a refresh operation needs to be performed on one page of the earliest written data, the following steps are repeatedly performed until it is determined that a page that does not need to perform a refresh operation is determined or until it is determined that a page of the most recently written data needs to be executed Refresh operation:

Taking the currently determined page that needs to perform the refresh operation as the current page, and searching for the page in the flash memory according to the page number of the next page adjacent to the current page in the write order included in the OOB information of the current page. OOB information on the next page, and

Based on the found time of the data written in the next page included in the OOB information of the next page, the data storage duration and the current time, it is determined whether a refresh operation needs to be performed on the subsequent page.
The apparatus according to claim 18 or 19, wherein in said method executed by said processor, the page number of the page of the earliest written data in the expired time queue information or the most recent write data is used. The page number of one page, the OOB information of the page in which the data is written in the flash memory, and the length of the data storage period, and the page that needs to perform the refresh operation, including:

Searching, in the flash memory, OOB information corresponding to a page of the most recently written data according to a page number of a page of the most recently written data;

Determining whether it is necessary to perform a refresh operation on a page of the most recently written data according to the time when the data is written on the page, the data storage duration, and the current time included in the found OOB information;

If it is determined that a refresh operation needs to be performed on a page of the most recently written data, it is determined that a refresh operation needs to be performed on all unupdated pages before the one page of the most recent write data in the write order;

If it is determined that it is not necessary to perform a refresh operation on the page of the most recently written data, the following steps are repeatedly performed until it is determined that the page requiring the refresh operation needs to be performed, and it is determined that the refresh operation needs to be performed in the determined write order. A refresh operation is performed on all pages before the page, or until it is determined that a refresh operation is not required on the page of the earliest written data:

Taking the currently determined page that does not need to perform the refresh operation as the current page, searching in the flash memory according to the page number of the previous page adjacent to the current page in the writing order included in the OOB information of the current page. The OOB information of the previous page, and according to the found time of the data written in the previous page included in the OOB information of the previous page, the data storage duration and the current time, it is determined whether the previous one needs to be The page performs a refresh operation.