KR101596833B1 - Storage device based on a flash memory and user device including the same - Google Patents

Abstract

A user device according to the present invention comprises: a storage medium for storing data; And a controller for controlling the storage medium, wherein the controller can selectively perform an invalidation operation or a logging operation depending on whether a size of data to be deleted exceeds a reference size. The reference size is variable through firmware update.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a storage device based on flash memory and a user device including the storage device.

The present invention relates to a flash memory based storage device and a user device including the same.

The user device may be a memory card, a USB memory, a solid state drive (SSD), a hard disk drive (HDD), or the like, as well as a host such as a personal computer, a digital camera, a camcorder, Storage device. The user device may include a storage device within the host. The storage device may include volatile memory such as DRAM, SRAM and the like and nonvolatile memory such as EEPROM, FRAM, PRAM, MRAM, Flash Memory and the like.

Data stored in the storage device can be deleted by the user's command. In general, the delete operation is performed through the host's file system (e.g., FAT). The file system applies a delete command to the storage device. In addition, the file system can recover deleted data under certain conditions. The file system applies a recovery command to recover the data.

It is an object of the present invention to provide a storage device capable of improving the response speed to a host command and a user device including the storage device. It is another object of the present invention to provide a storage device capable of preventing exposure of security data and a user device including the same.

A user device according to the present invention comprises: a storage medium for storing data; And a controller for controlling the storage medium, wherein the controller can selectively perform an invalidation operation or a logging operation depending on whether a size of data to be deleted exceeds a reference size. The reference size is variable through firmware update.

In an embodiment, the user apparatus further includes a host that manages file data using a file system, and the controller can perform an invalidation operation using the file system information of the host. The storage medium may include an area for storing the file system information.

In another embodiment, the user device includes a host for providing an invalidate command; And a buffer memory for temporarily storing data to be stored in the storage medium, wherein the controller can invalidate data stored in the buffer memory in response to the invalidation command. The controller may include a mapping table for invalidating data stored in the buffer memory. The controller may update the mapping table in response to the invalidation command.

In another embodiment, the user apparatus further includes a host having a buffer memory for temporarily storing data to be stored in the storage medium, and the host can perform an invalidation operation for the buffer memory. The host may include a mapping table for invalidating data stored in the buffer memory.

In another embodiment, the controller may determine whether the write operation is related to metadata when a write operation is requested, and update the mapping information of the user data according to the determination result. When the writing operation is determined to be related to the partition metadata, the controller may update the mapping information so that user data corresponding to the partition metadata is invalidated.

As another example, the controller of the user device may delay the erase operation on the data to be erased. The controller may include an invalid delay queue for delaying an invalidation operation on data to be deleted. Data to be deleted may be sequentially registered in the invalidation delay queue and sequentially invalidated according to the first-in first-out method.

According to another aspect of the present invention, there is provided a user apparatus comprising: a storage medium for storing data; And a controller for controlling the storage medium. The controller can discriminate whether data to be deleted is data requiring security, and selectively perform an invalidation operation according to a determination result. Here, when the data to be deleted does not require security, the controller can selectively perform an invalidation operation or a logging operation depending on whether the size of data to be deleted exceeds a reference size. When the data to be deleted requires security, the controller can perform the invalidation operation without delay.

In an embodiment, the user apparatus further includes a host that manages file data using a file system, and the controller can perform an invalidation operation using the file system information of the host.

In another embodiment, the user device includes a host for providing an invalidate command; And a buffer memory for temporarily storing data to be stored in the storage medium, wherein the controller can invalidate data stored in the buffer memory in response to the invalidation command.

In another embodiment, the controller may determine whether the write operation is related to metadata when a write operation is requested, and update the mapping information of the user data according to the determination result.

In yet another embodiment, the controller may include an invalid delay queue for delaying invalidation operations on data to be deleted.

According to the present invention, a response speed to a host command can be improved, and another object of the present invention can prevent exposure of security data.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, in order to explain the technical mappings of the present invention to those skilled in the art. .

A user device includes a host and a storage device. The user device may comprise a processor, main memory, and storage medium in hardware. Here, the processor or the main memory may be included in the host, and the storage medium (e.g., flash memory, PRMA, etc.) may be included in the storage device. The user device may also be software, including a user application, an O / S, a file system, a Flash Translation Layer (FTL), and the like.

The file (s) created on the host are managed by the file system. According to the control of the host's processor (e.g., CPU), the file data is transferred to the storage device. The transferred data will be stored in a storage medium (e.g., flash memory, PRAM, etc.) of the storage device. On the other hand, the file data requested by the host will be transferred from the storage device to the main memory of the host.

If any files are deleted from the host, they will be treated as deleted files by the file system. The fact that the file has been deleted means that the metadata of the deleted file has been changed as the file system management data. Even if the file is deleted from the host (in other words, even if the metadata of the deleted file is changed by the file system), the storage device can not determine whether it is an invalid file or not.

For this reason, a merge operation or a garbage collection operation for an invalid file is performed, which means that the performance of the storage device is degraded. In addition, an invalid file is stored in the storage device as if it is valid data, which means that the effective storage space of the storage device is reduced.

The storage device according to the embodiment of the present invention or the user device including the storage device according to the embodiment of the present invention can reduce the merge operation and the garbage collection operation on the invalid data through the invalidation operation. According to the present invention, the operation performance of the storage device or the user device can be improved, and the storage space and service life of the storage device can be increased. Various embodiments of the user apparatus for performing the invalidation operation will be described below.

Ⅰ. Logging  A user device that performs an invalidation operation

FIG. 1 is a block diagram illustrating an exemplary user device that performs an invalidation operation using a logging scheme. Referring to FIG. Referring to FIG. 1, a user apparatus 1000 according to an embodiment of the present invention includes a host 1100 and a storage device 1200.

Host 1100 may be configured to control storage device 1200. Host 1100 includes portable electronic devices such as, for example, personal / portable computers, PDAs, PMPs, MP3 players, and the like. When the contents (e.g., files) of data stored in the storage device 1200 are deleted from the host 1100, the host 1100 processes the metadata related to the file of the deleted content, Invalidates the file.

The host 1100 notifies the storage device 1200 of the invalidation (or deletion) of the files as needed. This may be accomplished by the host 1100 sending a specific command to the storage device 1200. Hereinafter, such a specific command is referred to as an " invalidity command ". The invalidation command may include information (for example, address information) for specifying an area to be deleted. The invalidation command can be used with various names such as a file delete command, an invalidity command, an unwrite command, and a deletion command.

Processing of the metadata for the file to be deleted will be performed by the file system of the host 1100. For fast operation, the file system will delete only the file's metadata, not the contents of the file. As an example of a FAT file system in the file system, a special code can be used as the first character of a file name to point to a deleted file. For example, place the hexadecimal byte code 'E5h' in the first character of the file name. This is a special tag that tells you that this file has been deleted.

When an arbitrary file is deleted, the file system will place a special code in the first character of the file name of the deleted file. When the metadata of a file to be deleted by the file system is processed, the contents of the file to be deleted are processed as invalid data in the file system, but remain as valid data in the storage device 1200.

For this reason, the storage device 1200 will recognize the memory block containing the data of the deleted file as a valid block. Thus, operations such as merge operations or garbage collection operations are performed on memory blocks (including data of deleted files), and as a result, the performance of the storage device 1200 or the user device will deteriorate. In order to prevent this, the file system of the host 1100 will provide an invalidation command to the storage device 1200 so that the contents of the deleted file are substantially invalidated in the storage device 1200.

1, storage device 1200 will operate in response to control of host 1100. The storage device 1200 will retain the stored data even if the power is turned off. The storage device 1200 may be, for example, a solid-state drive (SSD). However, it will be appreciated that the storage device 1200 is not limited to SSDs.

The storage device 1200 may include an SSD controller 1220A and a storage medium 1240. The SSD controller 1220A will control the storage medium 1240 in response to a request from the host 1100. The SSD controller 1220A will be connected to the storage medium 1240 through a plurality of channels CH1 to CHn. The storage medium 1240 may be comprised of a plurality of non-volatile memory chips. A plurality of nonvolatile memory chips will be commonly connected to each of the channels CH1 to CHn.

The storage medium 1240 may be composed of, for example, a plurality of flash memory chips. However, storage medium 1240 may be comprised of other non-volatile memory chips (e.g., PRAM, FRAM, MRAM, etc.) instead of flash memory chips. Each of the flash memory chips that make up storage medium 1240 will store 1-bit data or M-bit data per cell (where M is an integer greater than or equal to 2).

According to the user apparatus 1000 according to the embodiment of the present invention, when the invalidation command is provided from the host 1100, the storage apparatus 1200 records / writes only the position of the area (or files) And notifies the host 1100 that the execution of the requested command is completed.

In other words, the storage device 1200 will not directly invalidate the area of the files to be deleted, but will only record / store the location of the area of the invalid files. This will be described in detail below. In this case, it is possible to process the request of the host 1100 in a short time. That is, the response time to the request of the host 1100 can be shortened. In addition, it is possible to improve the performance of the storage device 1200 or the user device 1000 through a quick response.

2 is a block diagram schematically illustrating the SSD controller shown in FIG. 2, the SSD controller 1220A will include a host interface 1222, a flash interface 1224, a processing unit 1226, and a buffer memory 1228. It will be appreciated that the components of the SSD controller 1220A are not limited to those described herein. For example, it will be appreciated that the SSD controller 1220A further includes an error correction block for detecting and correcting errors in the data stored in the storage medium 1240. [

 The host interface 1222 provides an interface with the host 1100 and the flash interface 1224 provides an interface with the storage medium 1240. The processing unit 1226 generally controls the operation of the SSD controller 1220A and the buffer memory 1228 may be used to temporarily store the data to be stored in or read from the storage medium 1240. In addition, the buffer memory 1228 will be used to store the above-described history (recording of the area to be deleted in accordance with the invalidation command).

In an exemplary embodiment, additional volatile / nonvolatile memory (or registers) may be used in place of the buffer memory 1228 to store the aforementioned history. However, it will be appreciated that the medium for recording the location of the area to be erased in accordance with the invalidation command is not limited to that disclosed herein.

3 is a block diagram illustrating another embodiment of the SSD controller shown in FIG. 3, the SSD controller 1220B will include a host interface 1222, a flash interface 1224, a plurality of processing units 1226_1 through 1226_N, and a buffer memory 1228. [ It will be appreciated that the components of the SSD controller 1220B are not limited to those described herein. For example, it will be appreciated that the SSD controller 1220B further includes an error correction block for detecting and correcting errors in the data stored in the storage medium 1240. [

The SSD controller 1220B can perform various operations through the plurality of processing units 1226_1 to 1226_N. After the SSD controller 1220B divides the various control operations, the SSD controller 1220B can assign control operations corresponding to the respective processing units. The performance of the SSD controller 1220B including the plurality of processing units 1226_1 to 1226_N can be improved even if the SSD controller 1220B is driven by the low frequency clock.

4 is a flowchart illustrating an operation of a user apparatus according to an embodiment of the present invention. Hereinafter, the operation of the user apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

Host 1100 may provide an invalidation command to storage device 1200 as needed. For example, the invalidate command may be used to delete files having invalid contents among the files stored in the storage device 1200. [

First, in step S 1100, an invalidation command is transmitted from the host 1100 to the storage device 1200. As mentioned above, the invalidation command will contain information (e.g., address information) that informs the area of files with invalid content.

In step S1110, the storage device 1200, that is, the SSD controller 1220, will determine whether or not the capacity of the area to be deleted exceeds the reference capacity in accordance with the invalidation command. If it is determined that the capacity of the area to be deleted exceeds the reference capacity, in step S1120, the SSD controller 1220 will record / store the location of the area to be deleted. This operation is called "logging ". After the position of the area to be deleted is recorded, in step S1130, the SSD controller 1220 notifies the host 1100 that the execution of the invalidation command is completed. Thereafter, the procedure will end.

In an embodiment, the SSD controller 1220A includes a buffer memory (e.g., DRAM), and information indicating the location of the area to be erased will be recorded in the buffer memory. The location of the area to be erased can be recorded using a bitmap structure indicating the area to be erased where each bit exceeds the reference capacity. However, it will be appreciated that the logging scheme is not limited to the manner in which the location of the area to be erased is recorded. For example, it is possible to record the address information of the area to be deleted.

The history in which the position of the area to be deleted is recorded may be stored in the storage medium 1240 at a given time or as needed. The history thus stored will be loaded into the SSD controller 1220 at power-on. On the other hand, the history in which the position of the area to be deleted is recorded can be managed using the buffer memory. If an idle time occurs, the SSD controller 1220 invalidates the area to be deleted using the history stored in the buffer memory or storage medium 1240. [

Here, the invalidation means that the data recorded in the area to be deleted is processed as invalid data. This invalidation may be done by managing a mapping table in which a mapping between the physical blocks of the storage medium 1240 and the logical blocks is recorded. For example, such invalidation can be done by mapping out the mapping information for the area to be deleted in the mapping table or marking the area to be deleted in the mapping table. However, it will be appreciated that the invalidation is not limited to what is disclosed herein.

The flash memory chips constituting the storage medium 1240 are managed by a Flash Translation Layer (FTL) executed by the SSD controller 1220. The management of the mapping table will be done, for example, by such an FTL. The invalidated area of the storage medium 1240, that is, the invalidated memory blocks, will be erased as needed.

In an embodiment, the reference capacity may be set to be hardware or software variable. For example, the reference capacity may be set to be variable through updating of the firmware (FTL) of the storage device 1200. Alternatively, the reference capacity may be set to be variable by the host 1100. In this case, setting the reference capacity by storing a specific value indicating a reference capacity in a register (used to store the reference capacity) of the host interface 1222 during the recognition procedure between the host 1100 and the storage device 1200 It will be possible. The area to be deleted represents a logical area, which will be converted by the FTL to the physical area of the storage medium 1240.

In the embodiment, the capacity of the area to be deleted may be limited according to the storage device 1200 in accordance with the invalidation command. In this case, the maximum capacity of the area to be deleted is recorded in the storage device 1200 via the invalidation command, and the host 1100 uses the information indicating the maximum capacity of the area to be deleted recorded in the storage device 1200, .

Returning to step S1110, if it is determined that the capacity of the area to be deleted does not exceed the reference capacity, the procedure will proceed to step S1140. In step S1140, the SSD controller 1220 will process the data recorded in the area to be deleted with invalid data immediately without recording the location of the area to be deleted. This invalidation can be done by mapping out the mapping information for the area to be deleted from the mapping table or by marking the area to be deleted in the mapping table, as mentioned above.

The SSD controller 1220 will notify the host 1100 that the execution of the invalidation command has been completed in step S1130 after processing the data written in the area to be deleted into invalid data. Thereafter, the procedure will end.

The storage device 1200 according to the embodiment of the present invention can transmit an invalidation command to the host 1100 at a given / limited time (for example, a command from the host 1100), regardless of the capacity of the area to be deleted through the above- The time taken for processing). It is also possible to prevent program and erase operations for the invalidated area from being performed unnecessarily.

The storage device 1200 may be implemented to perform background operations during extra time (difference between a given / limited time and a substantial command processing time) that occurs when the host 1100 processes instructions rapidly within a given / limited time. In this case, a response to the requested command will be made before a given / limited time has passed.

Even if the data stored in a particular area of the storage medium 1240 is invalidated by a request (e.g., an invalidation command) of the host 1100, the storage medium 1240 Is substantially maintained as it is due to the characteristics of the storage medium 1240 that does not support overwriting. This is because the physical area of the storage medium 1240 is not actually managed but only the mapping information is managed through the FTL.

The storage device 1200 may be used in a device requiring security (e.g., a printer). In this case, such data will remain in the storage device 1200 after the data requiring security is processed. This means that the security data may be exposed unintentionally. In the case of deleting data requiring security, in the user equipment according to the embodiment of the present invention, the host 1100 transmits a security invalidation command or an invalidation command including information informing the deletion of security data to the storage 1200 ). This will be described later in detail with reference to FIG.

5 is a flowchart illustrating an operation of a user apparatus according to another embodiment of the present invention. Hereinafter, the operation of the user apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

Host 1100 may provide an invalidation command to storage device 1200 as needed. The invalidation command can be classified according to general data and data requiring security (hereinafter referred to as security data). For example, the host 1100 may provide an invalidation command when requesting deletion of general data and a secure invalidity command to the storage device 1200 when requesting deletion of secure data. Alternatively, the host 1100 may provide an invalidation command to the storage device 1200, including information indicating deletion of general data or deletion of secure data.

First, in step S 1200, a command is transmitted from the host 1100 to the storage device 1200. For convenience of description, assume that an instruction to notify the area to be deleted is input. If such an instruction and another instruction are input, the corresponding operation will be performed. In step S1210, the storage device 1200, that is, the SSD controller 1220, will determine whether the input command is an invalidation command or a security invalidation command. As another example, the SSD controller 1220 will determine whether the particular bit (s) of the invalidation command entered indicates deletion of generic data or deletion of secure data.

If it is determined that the input command is an invalidation command, the procedure will proceed to S1220. In step S1220, the SSD controller 1220 determines whether or not the capacity of the area to be deleted exceeds the reference capacity in accordance with the invalidation command. If it is determined that the capacity of the area to be deleted exceeds the reference capacity, in step S1230, the SSD controller 1220 writes / stores the location of the area to be deleted in the buffer memory. After the location of the area to be deleted is recorded, the procedure will proceed to step S1250.

If it is determined that the capacity of the area to be deleted does not exceed the reference capacity, the procedure will proceed to step S1240. In step S1240, the SSD controller 1220 will immediately process the data recorded in the area to be deleted, without recording the location of the area to be deleted, as invalid data. This invalidation can be done by mapping out the mapping information for the area to be deleted from the mapping table or by marking the area to be deleted in the mapping table, as mentioned above.

After the data recorded in the area to be deleted is immediately processed as invalid data, the procedure will proceed to step S1250. In step S1250, the SSD controller 1220 will notify the host 1100 that the execution of the invalidation command has been completed. Thereafter, the procedure will end.

Returning to step S1210, if it is determined that the input command is a security invalidation command, the procedure will proceed to step S1260. In step S1260, the SSD controller 1220 will immediately process the data recorded in the area to be deleted as invalid data. In addition, the SSD controller 1220 will control the storage medium 1240 such that the memory block (s) of the storage medium 1240 corresponding to the area to be erased is substantially erased. That is, the security data stored in the storage medium 1240 will be erased (or erased / erased). Thereafter, in step S1250, the SSD controller 1220 notifies the host 1100 that the execution of the input command is completed. Thereafter, the procedure will end.

The storage device 1200 according to the embodiment of the present invention can transmit an invalidation command to the host 1100 at a given / limited time (for example, a command from the host 1100), regardless of the capacity of the area to be deleted through the above- The time taken for processing). It is also possible to prevent exposure of security data of the storage device 1200 by performing an erase operation on the storage medium 1240 without a delay / delay when an instruction to delete the secure data is input.

4 and 5, regardless of the capacity of the area to be deleted (or the capacity of the area to be deleted corresponds to the capacity of the reference capacity) in the storage device 1200 according to the embodiment of the present invention, The position of the area to be deleted may be written / stored in the buffer memory without determining whether the value is exceeded. In other words, the storage device 1200 can be configured to record the position of the area to be deleted in the buffer memory each time an invalidation command is input. The invalidation for the logged area will be done during the idle time.

In an embodiment, the invalidation described above may optionally involve an operation in which information indicating invalid blocks is written to the memory block (s) of the storage medium 1240 corresponding to the area to be erased. Alternatively, the invalidation described above may involve an operation in which information indicating an invalid block is written to the memory block (s) of the storage medium 1240 corresponding to the area to be erased.

Ⅱ. A user apparatus that performs an invalidation operation using file system information

6 is a block diagram illustrating an embodiment of a user device that performs an invalidation operation using file system information. The user device 2000 shown in FIG. 6 includes a host 2100 and a data storage device 2200.

From the viewpoint of the host 2100, the data storage device 2200 is recognized as a storage medium that is free to read, write, and erase operations as if it is a hard disk. The data storage device 2200 may include a flash memory 2210 and a controller 2220. Here, other non-volatile memory (e.g., PRAM, FRAM, MRAM, etc.) may be used in place of the flash memory 2210

The flash memory 2210 is made up of a large number of memory cells having a string structure. The set of such memory cells is called a cell array. The memory cell array of the flash memory 2210 is composed of a plurality of blocks (Blocks). Each block is composed of a plurality of pages. Each page is composed of a plurality of memory cells (Memory Cells) sharing one word line. The flash memory 2210 performs an erase operation on a block-by-block basis, and reads and writes are performed on a page-by-page basis.

As described above, the unit of the read / write operation and the erase operation unit of the flash memory 2210 are different. Further, the flash memory 2210 is not overwritten unlike other semiconductor memory devices. Therefore, the flash memory 2210 necessarily performs the erase operation before performing the write operation.

Due to these characteristics of the flash memory 2210, the data storage device 2200 needs a separate unit of read, write, and erase operations to use the flash memory 2210 as a hard disk. The Flash Translation Layer (FTL) is the system software developed for this purpose.

Referring to FIG. 6, the flash memory 2210 includes a FAT area 2211, a data area 2212, a log area 2213, and a meta area 2214. Here, the FAT area 2211 is a kind of file system area.

In the FAT area 2211, file system information (e.g., FAT information) is stored. The log blocks of the log area 2213 are respectively assigned to some of the data blocks of the data area 2212. That is, when data is to be written to the data block of the data area 2212, the data is not directly written to the data block but is stored in the corresponding log block of the log area 2213.

However, if a log block in the log area 2213 corresponding to the data block in the data area 2212 is not specified, or if there is no empty page in the log block in the log area 2213, 2100), the merge operation is performed. Through the merge operation, a valid page of the log block and a valid page of the data block are copied to the new data block or log block. When the merge operation is performed, the mapping information is changed, and the changed mapping information is stored in the meta area 2214.

The controller 2220 is configured to control the flash memory 2120 when there is an access request from the host 2100. 6, the controller 2220 includes a control logic 2221 and a work memory 2222. [ The work memory 2222 stores a flash conversion layer (FTL). The control logic 2221 causes the flash translation layer (FTL) stored in the work memory 2222 to operate when there is an access request from the host 2100.

7 is a conceptual diagram showing a method of merging a user apparatus shown in FIG. Referring to FIG. 7, the user device 200 performs an invalidation operation using file system information (for example, FAT information).

6, the valid pages 2511, 2513 of the log block 2510 and the valid page 2522 of the data block 2520 are copied to the new data block 2530. [ The first and third pages 2511 and 2513 of the log block 2510 are copied to the first and third pages 2531 and 2533 of the new data block 2530, respectively. And the second page 2522 of the data block 2520 is copied to the second page 2532 of the new data block 2530.

Here, the method of merging the data storage device according to the present invention refers to the FAT information 2540 to selectively copy the valid pages of the data block 2520 into the new data block 2530.

Referring to FIG. 7, the FAT information 2540 stored in the flash memory (see FIG. 6, 2210) stores information about whether or not the corresponding page of the data block 2520 is allocated. For example, since the first page 2521 of the data block 2520 is a page not used to store the file, it is indicated as NA (Not Allocation) in the FAT information 2540. The second page 2522 of the data block 2520 is a valid page storing the file and is therefore denoted by A indicating Allocate to the FAT information 2540. [ FAT information 2540 corresponding to the third and fifth pages 2523 and 2525 of the data block 2520 is indicated by NA.

And the fourth page 2524 of the data block 2520 is a valid page storing the file but is marked as D indicating delete because it is a page erased from the file system viewpoint. That is, the data stored in the fourth page 2524 of the data block 2520 is a page that is valid in the FTL view but is no longer valid in the file system view. Thus, if the fourth page 2524 of the data block 2520 has erased data in terms of the file system, the data of that page is not copied into the new data block 2530.

Therefore, the user apparatus 2000 according to the embodiment of the present invention performs the invalidation operation by preventing the merge operation of the data which is no longer valid by referring to the file system information (for example, FAT information). According to the user apparatus 2000 according to the present invention, it is possible to reduce the total merge operation time by not performing copying of pages that are not necessary from the viewpoint of the file system.

8 is a flowchart showing an invalidation operation of the user apparatus shown in FIG.

In step S2610, the physical page of the new data block (see FIG. 7, 2530) is converted into a logical page. In step S2620, the FTL reads the FAT information in the FAT area 2211 of the flash memory (see FIG. 6, 2210). In step S2630, it is determined whether the corresponding page of the data block is a valid page to be copied by referring to the FAT information. That is, it is determined whether the corresponding page of the FAT area is allocated to store the file. If the page is a page on which no file is stored or a page that has been deleted, the process proceeds to the next step S2650 without copying to a new data block.

In step S2640, if the corresponding page of the data block is a valid page in which the file is stored, the data block is copied to the new data block. In step S2650, steps S2630 to S2640 are repeated for the remaining pages of the data block. After all page copies of the data block are performed, page copying of the log block is performed and the merge operation is terminated.

As described above, the user apparatus 2000 according to the embodiment of the present invention refers to the file system information (for example, FAT information) in the process of copying data, It is possible to reduce the merge operation time. The part that takes the most time in the merge operation is a section for copying the page data of the data block. The present invention can reduce the time of the copy section by selectively copying the pages of the data block.

For example, if the number of valid pages in the log block is x, the number of pages in the data block is y, and the time required to copy one page is z, the total time required for the merge operation is (x + y) * z. In this case, if the number of deleted pages is i from the point of view of the file system, i * z time in the merge execution time is unnecessary time. Therefore, the merge execution time reduced by the user apparatus and the merging method according to the present invention becomes (i * z- (time for reading the FAT area)).

Meanwhile, the user apparatus 2000 shown in FIG. 6 can perform the invalidation operation using the above-described logging method. That is, the user device 2000 applies a logging method of recording the position of the area to be deleted when the size of the data to be deleted exceeds the reference size, and can immediately invalidate the data to be deleted if the size of the data to be deleted does not exceed the reference size. In addition, the user apparatus 2000 may perform the invalidation operation according to whether or not erasure of the erasure or security data with respect to the general data, as described with reference to FIG.

Ⅲ. A user device for invalidating data in a buffer memory

9 is a block diagram illustrating an example of a user device for invalidating data in a buffer memory. Referring to FIG. 9, the user device 3000 includes a host 3100 and a storage device 3200. The host 3100 and the storage device 3200 may be connected by a standardized interface such as a USB, SCSI, ESDI, SATA, PCI-express, or IDE interface.

The host 3100 includes a central processing unit (CPU) 3110 and a memory 3120. At least a portion of the memory 3120 includes the main memory of the host 3100. Alternatively, the memory 3120 may be configured as the main memory of the host 3100. [

An application program 3121 and a file system 3122 are provided in the memory 3120, respectively. The file system 3122 includes all file systems including a file allocation table (FAT) file system. However, the file system is not limited to those skilled in the art.

When all or part of the file data processed by the application program 3121 is deleted, the central processing unit 3110 can provide an invalidation command to the storage device 3200. [ Address information and data size information for designating deleted data together with the invalidation command may be transmitted to the storage device 3200. [

The FAT file system includes a master boot record (MBR), a partition boot record (PBR), primary and secondary file allocation tables (primary FAT), and a root directory can do. A file to be stored / stored in the storage device 3200 can be confirmed using two pieces of information. The information is the file name of the file and the path of the directory tree through which the file is stored to reach where it is stored.

Each entry in a directory has, for example, a 32-byte length and stores information such as file name, extension, file attribute byte, last modified date / time, file size, and connection to the startup cluster . Particularly, in the file name, one special code is used as the first character of the file name to indicate the deleted file.

For example, place the hexadecimal byte code E5h in the first character of the file name. This is a special tag, telling the system that this file has been deleted. When an arbitrary file is deleted, the central processing unit 3110 places a special code in the first character of the file name of the deleted file, and sets an invalidation command corresponding to the deleted file (or invalidation of the deleted file data Information) to the storage device 3200.

9, the storage device 3200 includes a storage medium 3220, a buffer memory 3240, and a controller 3260. When the invalidation information (for example, the invalidation command, the address information of the file data deleted at the upper level of the storage device, and the size information of the deleted data) is inputted from the outside, the storage device 3200 stores, (Indicating data already deleted at the upper level of the storage device) of the storage medium 3220 is written to the storage medium 3260. This will be described in detail later.

The storage medium 3220 is for storing data (including all kinds of storable data such as document data, image data, music data, and programs), and may be composed of a nonvolatile memory such as a magnetic disk or a flash memory . However, it will be apparent to those skilled in the art that the storage medium 3220 is not limited to what is disclosed herein.

The buffer memory 3240 is used for smooth data transfer between the host 3100 and the storage medium 3220 and may be a high-speed volatile memory such as DRAM or SRAM or an MRAM, a PRAM, a FRAM, a NAND flash memory, or a NOR Volatile memory such as a flash memory. By way of example, storage medium 3220 and buffer memory 3240 may be equally configured into a memory such as flash memory.

Buffer memory 3240 may operate as a write buffer. For example, the buffer memory 3240 may operate as a write buffer for temporarily storing data to be used for the storage medium 3220 at the request of the host 3100. [ In addition, the function of the write buffer can be selectively used. For example, as the case may be, the data transferred from the host 3100 may be transferred directly to the storage medium 3220 without passing through the write buffer, that is, the buffer memory 3240. This function of the storage device 3200 is called a write bypass function.

Alternatively, the buffer memory 3240 may operate as a read buffer. For example, the buffer memory 3240 may operate as a read buffer for temporarily storing data read from the storage medium 3220 at the request of the host 3100. [ Although only one buffer memory is shown in the figure, two or more buffer memories may be provided. In this case, each buffer memory can be used as a write buffer, a read buffer, or a buffer having both functions.

Controller 3260 is configured to control storage medium 3220 and buffer memory 3240. When a read command is input from the host 3100, the controller 3260 controls the storage medium 3220 such that the data stored in the storage medium 3220 is transferred to the host 3100. Alternatively, when a read command is input from the host 3100, the controller 3260 causes the storage medium 3220 and the buffer memory 3220 to move data stored in the storage medium 3220 to the host 3100 through the buffer memory 3240, (3240).

When a write command is input from the host 3100, the controller 3260 causes the data associated with the write command to be temporarily stored in the buffer memory 3240. All or a portion of the data temporarily stored in the buffer memory 3240 is written to the controller 3260 when there is insufficient free space in the buffer memory 3240 or when idle time (idle time of the controller 3260 that occurs when there is no request from the host) And is transferred to the storage medium 3220 under the control of the control unit 3220. [

In order to perform the above operation, the controller 3260 compares address mapping information between the storage medium 3220 and the buffer memory 3240 and information indicating whether the data stored in the buffer memory 3240 is valid information And a mapping table 3261 for storing write status information.

The write status information is updated according to the invalid information provided from the outside, which will be described later in detail. The controller 3260 controls the storage medium 3220 and the buffer memory 3240 so that all or a part of the data stored in the buffer memory 3240 is written to the storage medium 3220 according to the writing state information of the mapping table 3261 , Which will be described later in detail.

As can be seen from the above description, the storage device 3200 stores the mapping table 3261 when the free space of the buffer memory 3240 is insufficient or the idle time (idle time of the controller 3260 that occurs when there is no request from the host) And does not transfer all or a part of the data stored in the buffer memory 3240 to the storage medium 3220.

That is, the storage device 3200 receives invalid information indicating whether the data stored in the buffer memory 3240 is valid data or invalid data, from the outside (for example, a host) of the storage device 3200, And prevents invalid data in the buffer memory 3240 from being written to the storage medium 3220.

In other words, the storage device 3200 selectively tags the data stored in the buffer memory 3240 with a tag of valid / invalid information, thereby transferring data to the storage medium 3220. Accordingly, the write performance of the storage device 3200 is improved, the lifetime of the storage medium 3220 due to unnecessary write operation can be prevented, and power consumption due to unnecessary write operation can be reduced.

FIGS. 10 and 11 are views showing, by way of example, the mapping table of the controller 3260 shown in FIG. 10 and 11, the symbol "BBN" indicates the block number of the buffer memory 3240, the symbol "DCN" indicates the cluster number of the storage medium 3220, and the symbol "WSI" Indicates whether or not the data stored in the data area is valid data.

For convenience of explanation, it is assumed that the block size of the buffer memory 3240 is equal to the size of a cluster composed of a plurality of sectors. It will be apparent, however, to those skilled in the art that the allocation unit of the storage medium 3220 is not limited to what is disclosed herein. For example, it is apparent to those skilled in the art that the allocation unit of the storage medium 3220 can be designated as a sector of a magnetic disk or as a page, sector, or block of a flash memory. 10 and 11, the invalid data is indicated by 'X', and the valid data is indicated by 'V'.

As shown in FIG. 10, assume that data related to three files FILE1, FILE2, and FILE3 are stored in the buffer memory 3240 as valid data. Each piece of data may be data read from the storage medium 3220 and updated by the host 3100 and not yet stored in the storage medium 3220. Or data that is communicated at host 3100 and not yet stored in storage medium 3220.

The file data FILE1, FILE2 and FILE3 stored in the buffer memory 3240 are stored in the buffer memory 3240 under the control of the controller 3260 when the free space of the buffer memory 3240 is insufficient or when there is an idle time, Media 3220. < / RTI > The controller 3260 is configured to update the write status information of the stored file data FILE1, FILE2, and FILE3 according to the invalid information transmitted from the host 3100. [

For example, when invalid information indicating that the file data FILE2 has been deleted from the host 3100 as the upper level of the storage device 3200 is input from the host 3100, the controller 3260, as shown in FIG. 11, The write status information of the file data FILE2 is indicated by 'X' so as to indicate invalid data. In addition, the controller 3260 displays the write status information of the data written in the storage medium 3220 as 'X' to indicate the invalid data.

12 is a flowchart for explaining an operation for invalidating buffer memory data of the user apparatus shown in FIG. The invalidation operation of the user device 3000 shown in Fig. 9 is performed in S3100 of determining whether or not an invalidation instruction is issued from the outside of the storage device 3200 and a step S310 of temporarily storing the invalidation instruction in the buffer memory 3240 And S3120 of invalidating all or a part of the stored data. Thereafter, the invalidated data is not used in the storage medium 3220.

13 to 15 are diagrams for explaining the invalidation operation of the user apparatus shown in FIG. The controller 3260 of the storage device 3200 refers to the mapping table 3261 to reserve the free space of the buffer memory 3240 or to utilize the idle time, And transfers the stored data files to the storage medium 3220.

As shown in FIG. 13, assume that three file data (FILE1-FILE3) are stored in the buffer memory 3240 as valid data. The controller 3260 of the storage device 3200 refers to the writing state information WSI of the mapping table 3261 associated with the stored file data FILE1-FILE3 to determine whether the data is invalid data do.

FILE3 is displayed as valid data in the mapping table 3261 as shown in Fig. 13, the controller 3260 determines that the file data FILE1-FILE3 is stored in the storage medium 3261 according to the determined method, And controls the storage medium 3220 and the buffer memory 3240 to be moved to the corresponding space of the storage medium 3220.

If invalid information (including an invalidation command, address information of an invalid data file, and size information of invalid file data) is input from the outside of the storage device 3200 before data is transferred to the storage medium 3220 The controller 3260 of the storage device 3200 invalidates the file data (e.g., FILE2) associated with the invalidation information.

14, the writing state information WSI of the mapping table 3261 associated with the file data FILE2 is updated under the control of the controller 3260 to indicate invalid data. The controller 3260 of the storage device 3200 refers to the write status information WSI of the mapping table 3261 associated with the stored file data FILE1-FILE3 to determine which data files are invalid data .

14, only the file data FILE1 and FILE3 are displayed as valid data in the mapping table 3261, the controller 3260 determines that the file data FILE1 and FILE3 are stored in the storage medium 3220 and the buffer memory 3240 so as to be transferred to the corresponding space of the storage medium 3220 and the buffer memory 3240. That is, the controller 3260 prevents the file data FILE2 from being transferred to the corresponding space of the storage medium 220. [ The space of the buffer memory 3240 processed with invalid file data can be used for a write / read operation to be performed subsequently.

As another example, suppose that only one file data FILE1 is stored in the buffer memory 3240, as shown in Fig. If the invalidation command is input from the outside of the storage device 3200 before the data transfer operation to the storage medium 3220, the controller 3260 of the storage device 3200 invalidates the data FILE1 associated with the invalidation command .

15, the writing state information WSI of the mapping table 3261 associated with the data FILE1 is updated under the control of the controller 3260 to indicate invalid data. The controller 3260 of the storage device 3200 refers to the writing state information WSI of the mapping table 3261 associated with the stored data FILE1 to determine whether the stored data is invalid data do.

As shown in Fig. 15, since there is no data displayed as valid data in the mapping table 3261, no transfer operation occurs in the storage device 3200. [ In particular, invalid data transfer operations in the idle state can be prevented. The space of the buffer memory 3240 processed with invalid data can be used for a write operation to be performed later.

Note that even if the data represented by the invalid data is written to the storage medium 3220, the file associated with the invalid data, which is the data stored in the storage medium 3220, is not affected. In addition, the invalidated data can be selectively transferred to the storage medium 3220 under the control of the controller 3260. [ For example, even if the data in the buffer memory 3240 is invalidated in accordance with the invalidation command, the controller 3260 can be configured to perform the data transfer operation selectively invalidated.

The storage device 3200 shown in FIG. 9 refers to a mapping table including write state information (WSI) indicating whether or not data stored in the buffer memory 3240 is invalid data, And controls the operation of transferring the stored data to the storage medium 3220. [ As described above, the writing state information of the data is provided from the outside of the storage device 3200, and the data is data generated and transmitted outside the storage device 3200. [

Alternatively, the data may be new data that has been read from storage medium 3220 and changed outside storage device 3200. Such a storage device 3200 may be applied to user devices as well as devices that want to store data (e.g., MP3 players based on hard disks or flash memory, portable electronic devices, or the like) Are obvious to those who have acquired common knowledge in the field.

16 is a block diagram illustrating another embodiment of a user device for invalidating data in a buffer memory. Referring to FIG. 16, a user device 4000 includes a host 4100 and an external storage device 4200.

Host 4100 includes a processing unit 4110, a memory 4120, and a buffer memory 4130. The processing unit 4100 may include a central processing unit (CPU), a microprocessor, and the like. Preferably, the processing unit 4110 will be implemented as a central processing unit. The processing unit 4110 will be configured to control the overall operation of the host 4100.

The host 4100 will be configured to perform the role of the controller 3260 described in FIG. For example, the processing unit 4110 may be configured to prevent the data in the buffer memory 4130 from being written to the external storage device 4200 in accordance with the mapping table 4124 in the memory 4120. This will be described in detail later.

16, at least a portion of the memory 4120 includes the main memory of the host 4100. [ Alternatively, the memory 4120 constitutes the main memory of the host 4100. An application program 4121 and a file system 4122 are provided in the memory 4120, respectively. The file system 4122 includes all file systems including the FAT file system. However, the file system is not limited to those skilled in the art.

In the memory 4120, a device driver 4123 and a mapping table 4124 will be further provided. The device driver 4123 is used for the control and the interface of the external storage device 4200. The processing unit 4110 will control the interface with the external storage device 4200 using the device driver 4123.

In addition, the processing unit 4110 will be configured to manage the address mapping between the external storage device 4200 and the buffer memory 4130 using the device driver 4123. The mapping table 4124 stored in the memory 4120 includes interface information with the external storage device 4200, address mapping information between the external storage device 4200 and the buffer memory 4130, and data stored in the buffer memory 4130 It will be used to store write status information indicating whether or not it is valid information.

The write status information will be updated by the processing unit 4110. For example, when all of the data of a file processed by an application program 4121 is deleted, or when a part of a file processed by an application program 4121 is deleted, the processing unit 4110 reads the device driver 4123, The writing state information of the mapping table 4124 is updated.

The processing unit 4110 is configured to store the buffer memory 4130 and the external storage device 4200 such that all or a part of the data stored in the buffer memory 4130 is written to the external storage device 4200 in accordance with the writing state information of the mapping table 4124. [ ). Therefore, it is possible to prevent the data in the buffer memory 4130 corresponding to the already deleted data from being written to the external storage device 4200. [

The buffer memory 4130 is used for smooth data transfer between the user device 4100 and the external storage device 4200 and may be a high-speed volatile memory such as a DRAM or SRAM or an MRAM, a PRAM, a FRAM, a NAND flash memory, Or a non-volatile memory such as a NOR flash memory. Preferably, the buffer memory 4130 will be implemented as a NAND flash memory.

Buffer memory 4130 may be used as a write buffer. For example, the buffer memory 4130 may be used as a write buffer for temporarily storing data to be used in the external storage device 4200 at the request of the processing unit 4110. [ In addition, the function of the write buffer can be selectively used. For example, in some cases, the data processed by the processing unit 4110 may be transferred directly to the external storage device 4200 without passing through the write buffer, i.e., the buffer memory 4130. [

Buffer memory 4130 may be used as a read buffer. For example, the buffer memory 4130 may be used as a read buffer for temporarily storing data read from the external storage device 4200 at the request of the processing unit 4110. [ Although only one buffer memory is shown in the figure, two or more buffer memories may be provided. In this case, each buffer memory can be used as a write buffer, a read buffer, or a buffer having both functions.

16, the external storage device 4200 is for storing data (including document data, image data, music data, and all types of storable data such as programs), and may be a magnetic disk or a flash memory And a nonvolatile semiconductor memory such as a nonvolatile semiconductor memory.

The external storage device 4200 will not be provided with a buffer memory. This is because the buffer memory of the host 4100 is used as a cache memory which is a write buffer / read buffer. In this case, the buffer memory 4130 and the external storage device 4200 will function as a hybrid hard disk (HHD).

16, the processing unit 4110 is configured to control the external storage device 4200 and the buffer memory 4130. The processing unit 4110 controls the external storage device 4200 using the device driver 4123 so that the data stored in the external storage device 4200 is moved to the host 4100 as needed. Alternatively, the processing unit 4110 may use the device driver 4123 to transfer data stored in the external storage device 4200 to the host 4100 through the buffer memory 4130, And controls the buffer memory 4130.

The processing unit 4110 causes the data to be stored in the external storage device 4200 to be temporarily stored in the buffer memory 4130. All or a portion of the data temporarily stored in the buffer memory 4130 is read out from the external storage device 4110 under the control of the processing unit 4110 when the free space of the buffer memory 4130 is insufficient or when the idle time of the processing unit 4110 occurs, (4200).

In order to perform the above operation, as described above, the processing unit 4110 determines whether the address mapping information between the external storage device 4200 and the buffer memory 4130 and whether the data stored in the buffer memory 4130 is valid information And a mapping table 4124 for storing the write status information indicating whether or not the write status information is stored.

The host 4100 and external storage device 4200 may be connected by standardized interfaces such as ATA, SATA, USB, SCSI, ESDI, PCE-express, or IDE interfaces. However, it is apparent to those skilled in the art that the interface scheme for connecting the host 4100 and the external storage device 4200 is not limited thereto.

As can be appreciated from the above description, the user device 4000 in accordance with the embodiment of the present invention is able to write (or write) the mapping table 4124 when there is insufficient free space in the buffer memory 4130 or when idle time of the processing unit 4110 occurs. All or a part of the data stored in the buffer memory 4130 is not transferred to the external storage device 4200 with reference to the status information.

That is, the user apparatus 4000 according to the embodiment of the present invention can determine whether the data stored in the buffer memory 4130 is valid data or invalid data, based on the writing state information of the mapping table 4124, Which prevents invalid data from being stored in the external storage device 4200.

In other words, the user device 4000 according to the embodiment of the present invention selectively controls the data transfer operation to the external storage device 4200 by attaching the tag of valid / invalid information to the data stored in the buffer memory 4130 . The operation of transferring the data stored in the buffer memory 4130 to the external storage device 4200 is the same as that described in Figs. 10 to 15. Therefore, the writing performance of the user device 4000 is improved, and the life of the external storage device 4200 due to the unnecessary write operation can be prevented from being shortened. In addition, battery life can be extended by reducing power consumption due to unnecessary write operations.

In some embodiments, the buffer memory 4130 may be implemented in the host 4100 in an on-board type. Alternatively, the buffer memory 4130 may be coupled to the host 4100 via a PCI bus or a PCI-E bus. However, it should be apparent to those skilled in the art that the connection method of the buffer memory 4130 is not limited to those disclosed herein. It will be apparent to those skilled in the art, for example, that all possible interfaces of a desktop computer and a notebook computer can be used.

When the buffer memory 4130 is implemented as a nonvolatile memory such as a NAND flash memory or a NOR flash memory, the buffer memory 4130 can be variously used. For example, the buffer memory 4130 may be used as a boot-up memory for storing a boot code used at boot time. This means that the buffer memory 3240 shown in Fig. 9 can also be used as the boot-up memory. In addition, important software may be stored in the buffer memory 4130 to improve system performance.

Meanwhile, the user device 3000 or 4000 shown in FIG. 9 or 16 can perform the invalidation operation using the above-described logging method. That is, when the size of the data to be deleted stored in the buffer memory exceeds the reference size, the user device (3000 or 4000) applies a logging method of recording the location of the area to be deleted. It can be immediately invalidated. In addition, the user device 3000 or 4000 may perform the invalidation operation depending on whether deletion is made to the erasure or security data for the general data, as described in FIG.

IV. A user device that performs an invalidation operation using an invalidation command

17 is a block diagram exemplarily showing a user apparatus that performs an invalidation operation using a file delete command. 17, the user device 5000 includes a host 5200 and a storage device 5205 that are connected via an interface 5210).

Interface 5210 may be a standard interface such as ATA, SATA, PATA, USB, SCSI, ESDI, IEEE 1394, IDE, PCI-express and / or card interface. Host 5200 includes a processor 5215 that communicates with memory 5220 via an address / data bus 5225.

Illustratively, the processor 5215 may be a commercially available or custom processor. The memory 5220 is one or more generic memory devices containing software and data for operating the user device 5000. The memory 5220 may include devices such as cache, ROM, PROM, EPROM, EEPROM, PRAM, flash memory, SRAM, and DRAM.

As shown in FIG. 17, memory 5220 includes five or more software and / or data categories. The software and / or data category may be an operating system (OS) 5228, an application 5230, a file system 5235, a memory manager 5240, and an input / output driver 5245.

The operating system 5228 controls the operation of the host 5200. More specifically, operating system 5228 may control software and / or hardware resources of host 5200 and may control program execution by processor 5215. Application 5230 represents various application programs running on host 5200.

File system 5235 stores or organizes computer files and / or data in a storage area, such as memory 5220 and / or storage device 5205. The file system 5235 is used in accordance with the particular operating system 5228 running on the host 5200. Memory manager 5240 controls memory access operations performed in memory 5220 and / or memory access operations performed on external devices such as storage device 5205. [ The input / output driver 5245 carries out information transfer between another device such as the storage device 5205, a computer system, or a network (e.g., the Internet) and the host 5200.

According to various embodiments of the present invention, host 5200 may be a personal digital assistant (PDA), a computer, a digital audio player, a digital camera, and a mobile terminal.

The storage device 5205 includes a controller 5250 that communicates with the memory 5255 via an address / data bus 5260. The memory 5255 may be various types of memory in which an erase operation is performed before a write operation. Illustratively, the storage device 5205 according to the present invention may be a memory card device, an SSD device, an ATA bus device, a SATA bus device, a multimedia card device, an SD device, a memory stick device, a hard disk drive device, May be a universal serial bus flash device.

The controller 5250 includes a processor 5265 that communicates with the local memory 5270 via an address / data bus 5275. Illustratively, processor 5265 may be a commercially available or custom microprocessor.

Local memory 5270 may be one or more conventional memory devices including software and data for operating storage device 5205 in accordance with the present invention. Local memory 5270 may include cache, ROM, PROM, EPROM, EEPROM, PRAM, flash memory, SRAM, and DRAM.

As shown in FIG. 17, local memory 5270 includes three or more software and / or data categories. The software and / or data category may be an operating system 5278, a Flash Transition Layer (FTL) module 5280, and a table 5285. The operating system 5278 controls the general operation of the storage device 5205. More specifically, the operating system 5278 may control software and / or hardware resources of the storage device 5205 and may control program execution by the processor 5265. On the other hand, according to an embodiment of the invention, local memory 5270 may not include operating system 5278.

The flash translation layer module 5280 may be used in a flash memory device. As described above, the flash chip is erased on a block-by-block basis. A typical flash memory device can perform approximately 100,000 erase operations per block. In order to prevent some blocks of the flash memory from being worn faster than other blocks, the flash memory device distributes the erase cycles throughout the memory. This is called wear management. For wear management, the flash translation layer module 5280 interfaces between the file / data storage location of the memory 5255 and the file system 5235. Thus, the file system 5235 does not need to maintain a track of the actual storage location of the file / data in the memory 5255.

Table 5285 may be maintained by flash translation layer module 5280 and may be used to associate the physical address of the memory allocation unit of memory 5255 with an index that indicates whether the memory allocation unit contains invalid data.

18 is a diagram illustrating a data structure according to the present invention that associates memory allocation units in storage device 5205 with an indicator that indicates whether memory allocation units contain valid or invalid data. In Fig. 18, the memory allocation unit is a page, and the block is shown as including four pages.

17 and 18, table 5285 associates the physical addresses of the pages of flash memory 5255 with the logical addresses used by file system 5235. Table 5285 also includes a column that indicates whether a particular page of flash memory 5255 contains invalid data or valid data.

In the embodiment shown in FIG. 18, the block of pages containing logical addresses 0-3 contains invalid data and may be erased. Table 5285 can be used to initiate an erase operation when all pages in the block contain invalid data.

In the conventional example, when a second write operation is attempted to the logical page address (0), it can be determined whether the logical page address (0) contains invalid data. However, it is unclear whether the logical page addresses 1-3 also contain invalid data. Therefore, in order to perform a write operation to the logical page address (0), the entire block including the logical page addresses (0-3) must be erased, so that the data in the logical page addresses (1-3) It should be copied. If the logical page address 1-3 contains invalid data, such a copy operation may not be required.

To reduce unnecessary copying operations as described above, table 5285 may provide an indicator that indicates pages that contain invalid data. In FIG. 18, although the data structure according to the present invention is shown as being in the form of a table, it will be understood that the data structure according to the present invention can be variously implemented with other types of data structures.

The computer program code for performing the operations of the user apparatus described with reference to Fig. 17 can be written in a high level programming language such as JAVA, C, and / or C ++. In addition, the computer program code for performing the operations according to the embodiments of the present invention may be written in an interpreted language. To improve operational performance and / or memory usage, some modules or routines may be written in assembly language or micro-code. The functionality of some or all of the program modules may be implemented as discrete hardware components, one or more application specific integrated circuits (ASICs), or a programmed digital signal processor or microcontroller.

In the following, the present invention is described with reference to a flow diagram, a flow diagram, and / or a block diagram illustrating a method, system, apparatus, and / or computer program product in accordance with an embodiment of the present invention. The flow, flow diagram, and / or block diagram of the message illustrates general operations for operating a data processing system including an external data storage device. Each of the diagrams of the message flow, flowchart and / or block diagram, and combinations thereof, may be implemented by computer program instructions and / or hardware operations. The computer program instructions may be provided to a processor of a general purpose computer, a special purpose computer, or other programmable data processing apparatus. The computer program instructions may be executed by a computer or a programmable data processing mechanism to provide a means for implementing the functions described in the flow, flowchart and / or block diagram of the message.

The computer program instructions may be stored in a computer usable or computer readable memory and may cause a computer or other programmable data processing apparatus to operate in a particular manner. That is, the instructions that are stored in a computer-usable or computer-readable memory may provide instructions that implement the functions described in the flow, flowchart, and / or block diagram of the message.

Computer program instructions may be loaded into a computer or other programmable data processing apparatus to cause a series of operating steps to be performed in a computer or other programmable apparatus to provide a computer-implemented process. That is, the instructions performed on the computer or other programmable mechanism provide operational steps for implementing the functions described in the flow, flowchart and / or block diagram of the message.

Figs. 19 to 23 are flowcharts for explaining the operations of the user apparatus shown in Fig. 19, in step S5400, the host 5200 delivers an invalidity command for one or more files to the external storage 5205. [ The external storage device includes a memory device, such as a flash memory device, in which an erase operation is performed before a write operation.

According to the embodiment of the present invention shown in Fig. 20, in step S5500, an invalidation operation is detected in the host 5200. Fig. For example, the detection operation can be performed by detecting that the metadata associated with the file system is updated with the deletion code for the deleted file. When the invalidation operation is detected in the host 5200, the invalidation command is transmitted to the external storage device 5205 in step S5505. The invalidate command may indicate the logical address associated with the deleted file and the data to be invalidated.

21, in step S5600, when an invalidation command is received from the host 5200, the invalidation operation is started in the external storage device 5205. [ The invalidate command may indicate the logical address of one or more files and the invalidated data. In step S5605, depending on the logical address and the data to be invalidated, the storage device 5205 identifies whether one or more memory allocation units in the memory 5255 contain invalid data.

Referring to FIG. 22, in step S5700, the flash transform layer module 5280 maintains a data structure such as the table 5285 shown in FIG. The data structure associates the logical address and the physical address of the memory allocation units of memory 5255. The data structure may also include an indicator indicating whether the various memory allocation units contain invalid data. In step S5705, if the physical address of the memory allocation unit is identified as being associated with the invalidated file, the flash translation layer module 5280 updates the data structure to indicate that the identified memory allocation unit contains invalid data do.

Since various memory operations are performed in the storage device, a garbage collection operation is required in order to acquire more usable and adjacent memory blocks. In accordance with an embodiment of the present invention, the flash translation layer module 5280 is operable until the operating system 5228 of the host 5200 or the operating system 5278 of the storage device 5205 performs periodic garbage collection operations Without waiting, the table 5285 can be used to determine the timing to collect memory units containing invalid data.

23, in step S5800, the flash conversion layer module 5280 determines whether each of the read / write operation units is an invalid data field, and determines whether the erase operation unit (for example, a block of the flash memory device) (For example, a page of the flash memory device) contained in the read-write operation unit contains invalid data.

In step S5805, if all of the read / write operation units in the erase operation unit are determined to contain invalid data, an erase operation of the erase operation unit can be performed. In this way, when the erase operation unit is erased, the actual physical file data can be erased. That is, performing the physical erase on the file in the storage device according to the present invention is performed faster than waiting for the physical erase to be performed due to the duplicate file write operation performed in the storage device. Thus, it can be applied to applications containing personal or sensitive data.

The flowcharts of FIGS. 19-23 illustrate embodiments of a method, system, and computer program product architecture, functionality, and operation for operating a user device including an external storage device in accordance with the present invention. In this regard, each block represents a module, a segment, or a portion of a code. A module, segment, or portion of code includes one or more executable instructions for implementing a particular logical function. The order of the functions performed in the blocks may be different from that shown in Figs. For example, two blocks shown in succession may be performed in the same or opposite order depending on the function.

Meanwhile, the user apparatus 5000 shown in FIG. 17 can perform the invalidation operation using the above-mentioned logging method. That is, the user device 5000 applies a logging method of recording the position of the area to be deleted when the size of the data to be deleted exceeds the reference size, and can immediately invalidate the data to be deleted if the size of the data to be deleted does not exceed the reference size. In addition, the user device 5000 may perform the invalidation operation according to whether or not erasure is performed on the erroneous or secure data with respect to the general data, as described with reference to FIG.

Ⅴ. A user device that performs its own invalidation operation

24 is a block diagram illustrating a storage device that performs self-invalidation operations without host intervention; In Fig. 24, as an example of a storage device, a solid state drive (SSD) will be described. Referring to FIG. 24, the SSD 6000 includes an SSD controller 6200 and a nonvolatile storage medium 6400. The SSD controller 6200 includes first and second interfaces 6210 and 6230, a controller 6220, and a memory 6240.

The first interface 6210 functions as a data input / output interface with the host. The first interface 6210 includes, but is not limited to, a Universal Serial Bus (USB) interface, an ATA interface, a SATA interface, a SCSI interface, and PCI-express.

The second interface 6230 functions as a data input / output interface with the nonvolatile storage medium 6400. In particular, the second interface 6230 is used to send / receive various commands, addresses, and data to and from the non-volatile storage medium 6400. A variety of different structures and configurations of the second interface 6230 are possible, and a detailed description thereof is omitted here for the sake of brevity.

The controller 6220 and the memory 6240 are connected between the first and second interfaces 6210 and 6230 and both control and control the flow of data between the host (not shown) and the non-volatile storage medium 6400. [ . The memory 6240 includes, for example, a DRAM, an SRAM, and the like. Controller 6220 includes, for example, a central processing unit (CPU), a direct memory access (DMA) controller, and an error correction control (ECC) engine.

Continuing with reference to FIG. 24, the non-volatile storage medium 6400 of this embodiment may include a high speed nonvolatile memory 6410 and a low speed nonvolatile memory 6420. However, the above-described embodiments are not limited to structures having dual-speed memories. That is, the non-volatile storage medium 6400 may be composed of a single type of memory operating at a single speed. The high speed nonvolatile memory 6410 is operable at a relatively high speed (e.g., a random write speed) as compared to the low speed nonvolatile memory 6420.

In an embodiment, high speed nonvolatile memory 6410 is a single-level cell (SLC) flash memory, and low speed nonvolatile memory 6420 may be a multi-level cell (MLC) flash memory. However, the present invention is not limited to this. For example, high speed nonvolatile memory 6410 may be a phase change random access memory (PRAM) or an MLC flash memory that stores one bit per cell. The high-speed nonvolatile memory 6410 and the low-speed nonvolatile memory 6420 may be composed of the same kind of memory. Where the operating speed differs depending on the fine-grain mapping to the high-speed nonvolatile memory 6410 and the coarse-grain mapping to the low-speed nonvolatile memory 6420. [

In general, high speed nonvolatile memory 6410 is used to store frequently accessed (written) data such as metadata, and low speed nonvolatile memory 6420 is used to store relatively less accessed .

That is, the data write frequency in the high-speed nonvolatile memory 6410 is statistically higher than the data write frequency in the low-speed nonvolatile memory 6420. [ Also, depending on the nature of each stored data, the storage capability of low-speed nonvolatile memory 6420 is typically higher than that of high-speed nonvolatile memory 6410. [ However, in other words, the above-described embodiments herein are not limited to the use of two or more memories operating at different rates.

25 shows an example of logically partitioning the storage area of the non-volatile storage medium 6400. Fig. Referring to FIG. 25, the first sector of the solid state drive includes a master boot record (MBR), and the remaining sectors are divided into a plurality of partitions. In addition, each of the partitions typically includes a boot record at the end of the logic.

FIG. 26 shows a well-known 512 byte example of the MBR shown in FIG. In general, the MBR is used, for example, to maintain a primary partition table of a solid state drive (SSD). It is also used for bootstrapping operations to perform the code instructions present in the MBR after the user device's bi-directional transmission. The MBR is also used to uniquely identify individual storage media.

FIG. 27 shows an example of the layout of a single 16-byte partition record of the MBR shown in FIG. In the example of the IBM Partition Table standard, four of the partition records shown in FIG. 27 include a partition table of the MBR.

28 is a table showing partition types and corresponding ID values. At this point, the operating system (OS) can create multiple partitions from the more detailed primary partitions. These partitions are referred to as "extended partitions". Each partition created on an extended partition is called a so-called logical partition, and each logical partition can be modified to the same or different file system.

The MBR technology described above is one of several standards in an increasingly advanced industry. For example, the Extensible Firmware Interface (EFI) standard is an alternative technology for the PC bias standard. On the other hand, the PC bias uses the MBR technique described above, and the EFI standard uses the GUID partition table (GPT) as the standard for the layout of the partition table in a logically partitioned solid state drive. The present invention is not limited to any particular partition standard.

The data contained in the MBR (or GUID) partition table of FIG. 26 is an example of " storage-level " metadata. For example, metadata associated with logical storage areas of a solid state drive (SSD). This is in contrast to "file system level" metadata, which is the metadata associated with the file system of the user device (or computer system). Examples of file systems include a file allocation table (FAT), a new technology file system (NTFS), second and third extended file systems ext2 and ext3.

That is, when the user deletes the file from the non-volatile storage medium 6400, the file system operating in the system processes the invalidation command. At this time, the file of the nonvolatile storage medium 6400 is deleted from the user's point of view. In practice, however, the file system does not change the file data in physical memory, but instead regards it as "invalid." The host includes an application program for communicating with the file system. The flash translation layer (FTL) tracks and maintains the physical location of the memory units of the non-volatile storage medium 6400 associated with each of the files. Thus, the file system can only refer to logical memory units.

Embodiments of the present invention, which will be described in more detail below, are controlled to at least partially monitor the updated metadata to retrieve locations of invalid data stored in a solid state drive (SSD).

The monitored metadata may be storage level metadata or file system level metadata. For example, in the case of storage level metadata, the metadata will be included in the partition table, and the invalid data is retrieved according to the changes in the metadata of the partition table.

In one embodiment, it is detected that the partition metadata of the solid state drive (SSD) has changed, and if so, the partition metadata is analyzed to retrieve the location of the invalid data stored in the solid state drive (SSD) . This analysis includes determining if the file system type of the partition has changed, and invalidating the data corresponding to the changed file system type. Alternatively or additionally, the analysis includes determining if the partition has changed and invalidating the data corresponding to the changed partition.

Reference is made to Figs. 29 and 30 for a method of invalidating a deleted data area of a solid state drive (SSD) according to an embodiment of the present invention.

In general, this embodiment relates to the monitoring of metadata contained in the same partition table as the standard table of the primary partitions of the MBR in the BIOS system. In steps S6510 and S6520 of FIG. 29, the MBR address area is monitored to determine if the MBR address is accessed. Examples of MBR, primary partitions, and partition records are shown in FIG.

If it is determined that the MBR address has been accessed, it is checked in step S6530 whether the partition table has been changed. For example, the partition table will change when the partition is partitioned. In this case, all data in the partitioned partition is invalidated.

In the case of Yes determination in step S6530, the start position of the partition and the type of the file system (partition type) are configured in step S6540. Then, in step S6550, the metadata is analyzed according to the file system type, and the deleted data area is invalidated.

A method of invalidating a deleted data area of a solid state drive (SSD) according to an embodiment of the present invention will be described with reference to FIG. 31 and FIG.

In general, this embodiment relates to the monitoring of metadata contained in a file allocation table (FAT). In particular, by checking the cluster association (or lack thereof), it is determined whether the data associated with the cluster is deleted data.

In general, the file system to be used to store files in a flash-based solid state drive (SSD) has a memory allocation unit defined to account for the smallest logical amount of disk space that can be allocated to hold the file. For example, an MS-DOS file system known as a file allocation table (FAT) calls this memory allocation unit a cluster.

In the method of FIG. 31, the file entry is initially checked at steps S6610 and S6620, and it is determined whether the file entry is [00 00 00 00]. If the determination in step S6620 is YES, then the matched clusters are not connected and the data thereof is invalidated in step S6630.

Reference is made to Figs. 33 and 34 for a method of invalidating a deleted data area of a solid state drive (SSD) according to an embodiment of the present invention.

In general, this embodiment relates to the monitoring of metadata contained in the New Technology File System (NTFS). Initially, in step S6710, the start of the master file table (hereinafter, MFT) from the NTFS boot record is checked. In this example, the bitmap that is the sixth entry of the MFT is retrieved in step S6720, and then the bitmap table is checked in step S6730. In step S6740, it is determined whether the deleted data exists in the bitmap table, and if the answer is Yes, the matched data area is invalidated.

By invalidating the data and data areas as described above, merge operations within the solid state drive (SSD) are possible without copying invalid data. In addition, for example, garbage collection operations can be made more efficient.

35 is a block diagram of a user device 6800 in accordance with an embodiment of the present invention. User device 6800 includes a bus system 6810 and a read only memory (ROM) 688 that stores software (e.g., BIOS) that is coupled to bus system 6810 and used to initialize user device 6800. [ .

User device 6800 also includes a random access memory 6830, a central processing unit 6840 and a solid state drive (SSD) system 6850 that function as a working memory, Lt; / RTI > Solid state drive (SSD) system 6850 includes a solid state drive (SSD) and a controller (e.g., see FIG. 24). 35, the solid state drive (SSD) system 6850 includes a master boot record, and is logically divided into a plurality of partitions.

Meanwhile, the storage device 6000 shown in FIG. 24 can perform the self-invalidation operation using the above-described logging method. That is, the storage device 6000 applies a logging method of recording the location of the area to be deleted when the size of the data to be deleted exceeds the reference size, and can immediately invalidate the data to be deleted if the size of the data to be deleted does not exceed the reference size. In addition, the storage device 6000 may perform the invalidation operation according to whether deletion of the general data or erasure of the secure data as described in FIG.

VI. Recover  The user device performing the operation

In the case of a hard disk that is directly under the control of the file system, the deleted data can be recovered by the recovery command of the file system, except when overwritten. However, in the case of flash memory devices, erase operations are performed through both the file system and the flash translation layer. Therefore, even if data can be recovered at the file system level, data recovery at the flash conversion layer level may not be possible. As a result, a method of recovering data in a semiconductor memory device using a conversion layer such as a flash memory device may be a problem.

36 is a block diagram showing a software structure of a user apparatus that performs a recovery operation. 36, the software architecture 7100 of the user device has a software hierarchy in the following order: application 7110, file system 7120, flash translation layer 7130, and flash memory 7140.

The file system 7120 receives commands from the application 7110. Instructions from application 7110 include a data store instruction, a data read instruction, a data move instruction, a data delete instruction, and a data recovery instruction. The file system 7120 passes the logical address of the data to be processed to the flash translation layer 7130.

The flash conversion layer 7130 receives a logical address from the file system 7120. [ The flash conversion layer 7130 converts the logical address into a physical address. The flash translation layer 7130 refers to an address mapping table for address translation. The address mapping table includes a plurality of mapping data. Each mapping data defines a correspondence relationship between a logical address and a physical address. The physical address is provided to the flash memory 7140.

The flash memory 7110 is divided into a meta data area and a user data area. In the user data area, user data such as text, video, and audio are stored. The metadata area stores information on user data. For example, location information of user data is stored in the metadata area. Accordingly, the file system 7120 can identify the storage location of the user data by referring to the metadata area.

In an embodiment in accordance with the present invention, the flash translation layer 7130 comprises a queue 7132. The queue is a kind of buffer that processes data in a first-in first-out (FIFO) manner. That is, the input data is output first. The flash conversion layer 7130 has a separate queue 7132 to prevent data from being lost by a merge or erase operation. This will be described in detail with reference to the drawings to be described later.

37 is a block diagram showing a hardware structure of a user apparatus that performs a recovery operation. 37, a user device 7200 includes a host 7280, a memory controller 7270, and flash memory devices 7210-7260. The flash memory devices 7210 to 7260 include a memory cell array 7210, a page buffer 7220, a row selection circuit 7230, a column selection circuit 7240, a data input / output circuit 7250, and a control logic 7260 .

The memory cell array 7210 is composed of a plurality of memory cells. The memory cell array 7210 is divided into a user data area 7211 and a meta data area 7212. In the user data area 7211, user data such as text, audio, and video are stored. In the metadata area 7212, meta data relating to user data is stored. For example, metadata stores location information of user data. Although not shown in the figure, the memory cell array 7210 will consist of memory cells arranged in a matrix of rows (or word lines) and columns (or bit lines). The memory cells may be arranged to have a NAND structure or have a NOR structure.

The page buffer circuit 7220 operates as a sense amplifier or as a write driver. In a read operation, the page buffer circuit 7220 reads data from the memory cell array 7210. [ In the program operation, the page buffer circuit 7220 drives the bit lines to the power supply voltage or the ground voltage, respectively, according to the data input through the column selection circuit 7240.

The row selection circuit 7230 is connected to the memory cell array 7210 via a word line. The row selection circuit 7230 is controlled by the control logic 7260. The row selection circuit 7230 drives the selected row and the unselected rows with corresponding word line voltages, respectively, in response to a row address. For example, during a program operation, the row selection circuit 7230 drives the selected row to the program voltage Vpgm and the unselected rows to the pass voltage Vpass, respectively. In a read operation, the row selection circuit 7230 drives the selected row to the read voltage (Vread) and the unselected rows to the pass voltage (Vpass), respectively.

Column select circuit 7240 reads data latched into page buffer circuit 7220 in response to a column address applied from a column address generating circuit (not shown in the figure) .

The data input / output buffer 7250 transfers the data input from the memory controller 7270 to the column selection circuit 7240. Alternatively, the data input / output buffer 7250 transfers the data input from the column selection circuit 7240 to the memory controller 7270.

The control logic 7260 is configured to control the overall operation of the flash memory device. For example, the control logic 7260 is configured to control a program, a read operation, an erase operation, and the like of the flash memory device.

The memory controller 7270 includes a mapping table 7271 and a queue 7272. The flash conversion layer 7130 shown in FIG. 35 is performed in the form of firmware on the memory controller 7270. The mapping table 7271 stores the correspondence between logical addresses and physical addresses. The mapping table 7271 is used by the flash translation layer 7130 to convert a logical address input from the host 7280 into a physical address. The flash translation layer 7130 passes the physical address to the flash memory device.

The queue 7272 is a kind of buffer that stores data in a first-in first-out (FIFO) manner. That is, the data first input to the queue 7132 is output first. The size of the queue 7132 can be changed as needed. In the present invention, the queue 7132 is provided to delay the invalidation of the mapping data and to prevent the data from being lost by the merge and erase operations.

A user device 7200 in accordance with an embodiment of the present invention may recover deleted data. Hereinafter, a data recovery method according to the present invention will be described in detail with reference to the drawings.

38 is a flowchart for showing a data erasing operation. Referring to FIG. 38, the data deletion operation is divided into three steps (S7110 to S7130).

In step S 7110, an invalidity command is input from the application 7110. The application 7110 is executed on the host 7280 in Fig.

In step S7120, the file system 7120 deletes the meta data of the data to be deleted in response to the invalidation command. The file system 7120 is performed on the host 7280 in Fig. File system 7120 may be included in an operating system.

In step S7130, the flash conversion layer 7130 invalidates the mapping table corresponding to the data to be deleted. Hereinafter, how metadata is deleted and how mapping data corresponding to data to be deleted are invalidated will be described in detail with reference to the drawings.

FIG. 39 is a conceptual diagram for explaining a method in which metadata is deleted when data is deleted. FIG. FIG. 39 (a) shows the state before the metadata is deleted, and FIG. 39 (b) shows the state after the metadata is deleted.

39 (a), user data named "Movie.avi" and "Music.mp3" are stored in a user data area. In the meta data area, metadata corresponding to each user data is stored. Each metadata will contain information about the storage location of corresponding user data. Accordingly, the file system 7120 can access the user data by referring to the metadata.

When an instruction to delete user data named "Movie.avi" is input from the application 7110, the file system 7120 deletes only the metadata corresponding to the user data. The file system 7120 does not delete the user data. 39 (b), it can be seen that only metadata has been deleted. Therefore, the file system 7120 recognizes that the user data named "Movie.avi" is deleted. That is, even after deletion, the user data exists in the user data area. In this case, only the corresponding relationship between the metadata and the user data is destroyed. Therefore, when restoration of data is required, user data can be normally accessed by restoring the deleted metadata.

FIG. 40 is a block diagram showing how mapping data corresponding to data to be deleted is invalidated in a data delete operation. FIG. 40 (a) shows a mapping table before data deletion, and FIG. 40 (b) shows a mapping table after data deletion.

In the embodiment, it is assumed that physical sector 1 to physical sector 10 (PSN 1 to PSN 10) correspond to data to be erased. In other words, the data to be deleted is stored in physical sector 1 to physical sector 10 (PSN 1 to PSN 10). Referring to FIG. 40 (a), the flash conversion layer 7130 associates a logical sector number with a physical sector number by referring to a mapping table 7131. For example, logical sector 1 (LSN 1) corresponds to physical sector 1 (PSN 1). The mapping table stores the validity of the physical sector. For example, the physical sectors 1 to 10 (PSN 1 to PSN 10) are designated as valid.

When a data invalidation command is input from the file system 7120, the flash conversion layer 7130 invalidates the mapping data corresponding to the data to be deleted. Referring to FIG. 40 (b), it can be seen that the physical sectors 1 to 10 (PSN 1 to PSN 10) are invalidated. Accordingly, the flash conversion layer 7130 can not convert the logical sector 1 to the logical sector 10 (LSN 1 to LSN 10) into physical sectors 1 to 10 (PSN 1 to PSN 10). This also means that the flash conversion layer can allocate physical sector 1 to physical sector 10 for storage of other data.

Since only the physical sector is invalidated by the erasing operation, the data stored in the physical sector is not actually erased. After all, there is data even after deletion. Therefore, when data recovery is required, validation of the invalidated physical sector can normally restore the data.

As described above, when deleting data, deletion of metadata by the file system 7120 and invalidation of mapping data by the flash conversion layer 7130 are simultaneously performed. As a result, the deletion operation is performed through deletion of the meta data and invalidation of the mapping data, instead of actually erasing the user data. Therefore, it is possible to restore the user data by restoring the meta data and validating the mapping data.

However, as the number of invalid physical sectors increases, the capacity of the flash memory device decreases. Thus, the flash memory device gathers internally valid physical sectors to increase the storage capacity, stores them in another physical sector, and erases invalid physical sectors. This is called a merge operation. In addition, data stored in the physical sector can be lost by an erase command from the outside.

41 is a conceptual diagram for explaining a merge operation. FIG. 41 (a) shows the mapping table before merging, and FIG. 41 (b) shows the mapping table after merging. 41 (a), it is assumed that the first and third physical sectors of the first block (Block 1) and the seventh and eighth physical sectors of the second block (Block 2) are invalidated by the erase operation . The invalidated blocks are subject to merge operations.

41 (b), only the valid sectors of the first block (Block 1) and the second block (Block 2) are stored in the third block (Block 3) by the merge operation and the first blocks (Block 1) And the second block (Block 2) are erased. When the physical sector is erased by the merge operation, existing data is permanently lost. The erased blocks may be allocated by the flash translation layer 7130 for storage of other data.

However, the merge operation is performed irrespective of the file system 7120. In order to improve the performance of the system, the merge operation can be performed while there is no command from the file system 7120 (background time). Thus, the invalidated sectors are at risk of being erased by the merge operation at any time. Therefore, in order to recover the data stored in the physical sector, the merge operation for the physical sector must be suppressed.

The user equipment 7200 according to an embodiment of the present invention delays invalidation of the mapping data. Alternatively, user equipment 7200 prevents invalid physical sectors from being merged and erased. Thus, the data stored in the physical sector can be recovered.

In the present invention, an invalid delay queue is used to delay the invalidation of the mapping data. The invalidation queue is sequentially registered with invalid physical sectors. When the invalidation delay queue becomes full, the registration of the physical sector registered first in accordance with the first-in first-out (FIFO) method is canceled. The unregistered physical sector is invalidated. The data stored in the physical sector can be restored by delaying the invalidation of the mapping data as described above. The size of the invalidation delay queue can be changed. For example, if the size of the invalid delay queue is large, invalidation of the mapping data will be delayed for a long time. Conversely, if the size of the invalid delay queue is small, the invalidation of the mapping data will be delayed for a short time.

42 is a conceptual diagram for explaining a method of operating the invalidation delay queue. Referring to FIG. 42, it is assumed that physical sectors 1, 3, 7, and 8 (PSN 1, 3, 7, 8) are invalidated in order by a data erasing operation. In the embodiment of the present invention, the physical sectors 1, 3, 7, 8 (PSN 1, 3, 7, 8) are not immediately invalidated by the deletion operation but are registered in the invalidation delay queue. To be more specific, first physical sector 1 (PSN 1) is registered in the invalidation delay queue. At this time, the data stored in the physical sector 1 (PSN 1) is not stored in the invalidation delay queue, but only the position of the physical sector 1 is stored. Physical sectors 3, 7 and 8 (PSN 3, 7, 8) are sequentially registered in the invalidation delay queue in the same manner.

The flash conversion layer 7130 does not invalidate the physical sector registered in the invalidation delay queue. Therefore, the physical sectors 1, 3, 7, 8 (PSN 1, 3, 7, 8) remain valid. If the invalidation delay queue is full, the registration of the physical sector PSN 1 registered first in accordance with the first-in first-out (FIFO) method is canceled. The physical sector whose registration is canceled from the invalidation delay queue is invalidated. The invalidated physical sector is subjected to merge and erase operations.

FIG. 43 is a flowchart for explaining a data recovery method using the invalidation delay queue of FIG. 42; FIG. Referring to FIG. 43, the data recovery method according to the present invention is divided into four steps (S7210 to S7240).

In step S7210, the application 7110 applies a data recovery command to the file system 7120. [ The file system 7120 passes the data recovery command to the flash translation layer 7130. In step S7220, the flash conversion layer 7130 determines whether the mapping data corresponding to the data to be restored in the invalidation delay queue is registered. When the mapping data corresponding to the data to be restored is registered in the invalidation delay queue, the step S7230 is performed, and if not, the data restoration is terminated. In step S7230, the flash conversion layer 7130 releases the registration of the mapping data corresponding to the data to be restored from the invalidation delay queue. In step S7240, the file system 7120 restores the metadata of the data to be recovered.

By restoring the metadata corresponding to the deleted data through the above-described method, it is possible to reliably restore the data. The order of updating the metadata recovery and invalidation delay queues can be changed. For example, the invalid delay queue may be updated after the metadata is recovered first.

In the above embodiment, invalidation delay of the mapping data is delayed by using the invalidation delay queue. However, in the case of a physical sector that has already been invalidated, the data stored in the physical sector can be protected by preventing the merge and erase operations from being performed.

In another embodiment of the present invention, a merge / erase protection queue is used to prevent merging and erasing operations on invalidated physical sectors. Invalid physical sectors registered in the merge / erase prevention queue are not merged and erased. Thus, the data stored in the physical sector can be retained. The size of the merge / erase prevention queue may be changed. For example, if the size of the merge / erase prevention queue is large, the merging and erasing operations of invalidated physical sectors will be prevented for a long time. Conversely, if the size of the merge / erase prevention queue is small, the merging and erasing operations of invalidated physical sectors will be prevented for a short time.

44 is a conceptual diagram showing a method of operating the merge / erase prevention queue. Referring to FIG. 44, it is assumed that physical sectors 1, 3, 7, and 8 (PSN 1, 3, 7, 8) are invalidated in order by a data erasing operation. In the embodiment of the present invention, the physical sectors 1, 3, 7, 8 (PSN 1, 3, 7, 8) are invalidated by the erase operation and then sequentially registered in the merge / erase prevention queue. To be more specific, first invalid physical sector 1 (PSN 1) is registered in the merge / erase prevention queue. At this time, data stored in the physical sector 1 (PSN 1) is not stored in the merge / erase prevention queue, but only the position of the physical sector 1 (PSN 1) is stored. Physical sectors 3, 7, 8 (PSN 3, 7, 8) are sequentially registered in the merge / erase prevention queue in the same manner.

The flash conversion layer 7130 excludes the physical sectors registered in the merge / erase prevention queue from the objects of the merge and erase operations. Thus, data stored in physical sectors 1, 3, 7, 8 are not merged and erased. If the merging / erasing prevention queue is full, the registration of the firstly registered physical sector is canceled according to the first-in first-out (FIFO) scheme. The physical sector whose registration is canceled from the invalidation delay queue is subjected to merge and erase operations.

45 is a flowchart for explaining a data recovery method using the merge / erase prevention queue of FIG. 44. FIG. Referring to FIG. 45, the data recovery method according to the present invention is divided into five steps.

In step S7310, a data recovery command is input from the application 7110 to the file system 7120. [ The file system 7120 passes the data recovery command to the flash translation layer 7130. In step S7320, the flash conversion layer 7130 determines whether the mapping data corresponding to the data to be restored in the merge / erase prevention queue is registered. If the mapping data corresponding to the data to be restored is registered in the merge / erase prevention queue, step S7330 is performed. If not, the data restoration is terminated.

In step S7330, the flash conversion layer 7130 validates the mapping data corresponding to the data to be restored through the mapping table. In step S7340, the flash conversion layer releases the registration of the mapping data corresponding to the data to be restored from the merge / erase prevention queue. In step S7350, the file system 7120 recovers the deleted metadata of the data to be recovered. The data is prevented from being lost by preventing the merging and erasing operations of the invalidated physical sectors through the above-described method. As a result, stable recovery of data becomes possible.

In another embodiment of the present invention, an invalid delay queue and a merge / erase prevention queue are used together. First, the invalidation delay of the mapping data is delayed through the invalidation delay queue. And then registering the invalid physical sector in the merge / erase prevention queue to prevent the merging and erasing operations on the invalid physical sector.

46 is a conceptual diagram for explaining an operation method when the invalidation delay queue and the merge / delete prevention queue are used at the same time. FIG. 46A shows a case where only an invalid delay queue is used, and FIG. 46B shows a case where an invalid delay queue and a merge / delete prevention queue are used together.

In the embodiment of the present invention, the invalidation is delayed by registering the mapping data corresponding to the data to be deleted in the invalidation delay queue. When the invalidation delay queue is full, the registration of the first registered physical sector is released according to the first-in first-out (FIFO) scheme. The mapping data released from the invalidation delay queue is registered in the merge / erase prevention queue. The mapping data registered in the merge / erase prevention queue is not subject to merge / erase. Therefore, the data stored in the physical sector is not lost by the merge and erase for a certain period of time.

Referring to FIG. 46 (a), it is assumed that the physical sectors 1, 2, 4, and 5 (PSN 1, 2, 4, 5) are sequentially invalidated. In an embodiment according to the present invention, the physical sectors are registered in the invalidation delay queue before being invalidated. The physical sectors registered in the invalidation delay queue are not invalidated. At this time, the merge / erase prevention queue is not used.

46 (b) shows a case where the physical sector 7 (PSN 7) is registered in the invalidation delay queue. When the invalidation delay queue becomes full, the registration of the physical sector 1 (PSN 1) first registered in accordance with the first-in first-out method is canceled. Physical sector 1 (PSN 1) that has been unregistered from the invalidation delay queue is invalidated. The invalid physical sector 1 (PSN 1) is registered in the merge / erase prevention queue. The physical sectors registered in the merge / erase prevention queue are excluded from the merge and erase operations.

47 is a flowchart for explaining a data recovery method using both the invalid delay queue and the merge / erase prevention queue of FIG. Referring to FIG. 47, the data recovery method according to the present invention is divided into seven steps.

In step S7410, a data recovery command is input from the application 7110 to the file system 7120. [ The file system 7120 passes the data recovery command to the flash translation layer 7130. In step S7420, the flash conversion layer 7130 determines whether the mapping data corresponding to the data to be restored in the invalidation delay queue is registered. If the mapping data corresponding to the data to be restored is registered in the invalidation delay queue, step S7430 is performed, and if not, step S7440 is performed.

In step S7430, the flash conversion layer 7130 releases the registration of the mapping data corresponding to the data to be restored in the invalidation delay queue. In step S7440, it is determined whether or not the mapping data corresponding to the data to be restored in the merge / erase prevention queue is registered. If the mapping data corresponding to the data to be restored is registered in the merge / erase prevention queue, the step S7450 is performed. If not, the data restoration is terminated.

In step S7450, the flash translation layer 7130 validates the invalid sector through the mapping table. In step S7460, the flash conversion layer 7130 releases the registration of the mapping data corresponding to the data to be restored in the merge / erase prevention queue. In step S7470, the file system 7120 restores the deleted metadata of the data to be recovered.

By the above-described method, the invalidation of the block corresponding to the deleted data is delayed, and the data is prevented from being lost by preventing the merging and erasing operation of the physical sector corresponding to the invalidated data. As a result, stable recovery of data becomes possible.

48 is a simplified block diagram illustrating a user device 7300 including a semiconductor memory device in accordance with an embodiment of the present invention. 48, a user device 7300 according to the present invention includes a semiconductor memory device 7310 comprising a nonvolatile memory device 7311 and a memory controller 7312, a central processing unit 7310 electrically connected to the system bus 7350, A device 7330, a user interface 7340, and a power supply 7320.

The nonvolatile memory device 7311 is provided with a user interface 7340 or the data processed by the central processing unit 7330 is stored through the memory controller 7312. [ The semiconductor memory device 7310 may be configured as a solid state drive (SSD), and the solid state drive supports recovery of erased data. SSD (solid state drive) products, which are expected to replace hard disk drives (HDDs) in recent years, are receiving attention in the next generation memory market. SSDs are faster than mechanical moving hard disk drives, are more resistant to external shocks, and have lower power consumption.

Although it is not shown in the drawing, the application device chipset, the camera image processor (CIS), the mobile DRAM, and the like can be further provided in the user device according to the present invention. It is clear to those who have learned.

The storage device according to the present invention can be implemented using various types of packages. For example, the flash memory and / or the controller may be implemented as a package on package (PoP), ball grid arrays (BGAs), chip scale packages (CSPs), plastic leaded chip carriers (PLCC), plastic dual in- Die in Wafer Form, Chip On Board (COB), Ceramic Dual In-Line Package (CERDIP), Plastic Metric Quad Flat Pack (MQFP), Thin Quad Flatpack (TQFP), Small Outline (SOIC), Shrink (SSOP), Thin Small Outline (TSOP), Thin Quad Flatpack (TQFP), System In Package (SIP), Multi Chip Package (MCP), Wafer-level Fabricated Package (WSP), and the like.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention. For example, the scope of the present invention is not limited to flash memory devices. The present invention can be applied to all storage devices in which address translation by the translation layer is used. Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by the claims equivalent to the claims of the present invention as well as the claims of the following.

FIG. 1 is a block diagram illustrating an exemplary user device that performs an invalidation operation using a logging scheme. Referring to FIG.

2 is a block diagram schematically illustrating the SSD controller shown in FIG.

3 is a block diagram illustrating another embodiment of the SSD controller shown in FIG.

4 is a flowchart illustrating an operation of a user apparatus according to an embodiment of the present invention.

5 is a flowchart illustrating an operation of a user apparatus according to another embodiment of the present invention.

6 is a block diagram illustrating an embodiment of a user device that performs an invalidation operation using file system information.

7 is a conceptual diagram showing a method of merging a user apparatus shown in FIG.

8 is a flowchart showing an invalidation operation of the user apparatus shown in FIG.

9 is a block diagram illustrating an example of a user device for invalidating data in a buffer memory.

FIGS. 10 and 11 are views showing, by way of example, the mapping table of the controller 3260 shown in FIG.

12 is a flowchart for explaining an operation for invalidating buffer memory data of the user apparatus shown in FIG.

13 to 15 are diagrams for explaining the invalidation operation of the user apparatus shown in FIG.

16 is a block diagram illustrating another embodiment of a user device for invalidating data in a buffer memory.

17 is a block diagram exemplarily showing a user apparatus that performs an invalidation operation using a file delete command.

18 is a diagram illustrating a data structure according to the present invention that associates memory allocation units of a storage device with an index that indicates whether memory allocation units contain valid or invalid data.

Figs. 19 to 23 are flowcharts for explaining the operations of the user apparatus shown in Fig. .

24 is a block diagram illustrating a storage device that performs self-invalidation operations without host intervention;

25 shows an example of logically dividing the storage area of the non-volatile storage medium.

FIG. 26 shows a well-known 512 byte example of the MBR shown in FIG.

FIG. 27 shows an example of the layout of a single 16-byte partition record of the MBR shown in FIG.

28 is a table showing partition types and corresponding ID values.

29-34 illustrate a method for invalidating a deleted data region of a solid state drive (SSD) in accordance with an embodiment of the present invention.

35 is a block diagram of a user device in accordance with an embodiment of the present invention.

36 is a block diagram showing a software structure of a user apparatus that performs a recovery operation.

37 is a block diagram showing a hardware structure of a user apparatus that performs a recovery operation.

38 is a flowchart for showing a data erasing operation.

FIG. 39 is a conceptual diagram for explaining a method in which metadata is deleted when data is deleted. FIG. FIG. 39 (a) shows the state before the metadata is deleted, and FIG. 39 (b) shows the state after the metadata is deleted.

FIG. 40 is a block diagram showing how mapping data corresponding to data to be deleted is invalidated in a data delete operation. FIG. 40 (a) shows a mapping table before data deletion, and FIG. 40 (b) shows a mapping table after data deletion.

41 is a conceptual diagram for explaining a merge operation. FIG. 41 (a) shows the mapping table before merging, and FIG. 41 (b) shows the mapping table after merging.

42 is a conceptual diagram for explaining a method of operating the invalidation delay queue.

FIG. 43 is a flowchart for explaining a data recovery method using the invalidation delay queue of FIG. 42; FIG.

44 is a conceptual diagram showing a method of operating the merge / erase prevention queue.

45 is a flowchart for explaining a data recovery method using the merge / erase prevention queue of FIG. 44. FIG.

46 is a conceptual diagram for explaining an operation method when the invalidation delay queue and the merge / delete prevention queue are used at the same time. FIG. 46A shows a case where only an invalid delay queue is used, and FIG. 46B shows a case where an invalid delay queue and a merge / delete prevention queue are used together.

47 is a flowchart for explaining a data recovery method using both the invalid delay queue and the merge / erase prevention queue of FIG.

48 is a block diagram schematically illustrating a user device including a semiconductor memory device according to an embodiment of the present invention.

Claims (22)

A storage medium for storing data; And And a controller for controlling the storage medium, Wherein the controller selectively performs an invalidation operation or a logging operation depending on whether the size of data to be deleted exceeds a reference size. The method according to claim 1, Wherein the reference size is variable through firmware update. The method according to claim 1, Wherein the controller performs an invalidation operation without delay if the data to be deleted requires security. The method according to claim 1, Wherein the controller performs an invalidation operation using the file system information. delete The method according to claim 1, Further comprising a buffer memory for temporarily storing data to be stored in the storage medium, Wherein the controller invalidates data stored in the buffer memory in response to an invalidation command. The method according to claim 6, Wherein the controller includes a mapping table for invalidating data stored in the buffer memory. 8. The method of claim 7, And the controller updates the mapping table in response to the invalidation command. A controller for selectively performing an invalidation operation or a logging operation depending on whether or not the size of invalid data exceeds a reference size; A host interface for receiving an invalidation command for notifying the stored area of the invalid data; And And a buffer memory for temporarily storing data received from the host interface, Wherein the controller executes the logging operation to store the position of the invalid data in the buffer memory in response to the invalidation command and executes the invalid data invalidation operation for the idle time. 10. The method of claim 9, And the controller invalidates the invalid data with respect to the position of the invalid data. 10. The method of claim 9, Wherein the controller transmits via the host interface that the execution of the invalidation command is completed in response to the invalidation command. delete delete delete delete delete delete delete delete delete delete delete

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