TWI656475B - Electronic system with data storage device - Google Patents

Abstract

The present invention provides an electronic system. The electronic system runs a host for operating a data storage device provided in the electronic system. The data storage device includes a flash memory and a controller. The flash memory includes a plurality of blocks, and the block includes a current block and a temporary block. The controller writes the first data corresponding to one of the first logical addresses into the current block, and determines whether the temporary block has the second data corresponding to one of the first logical addresses, where the temporary block has When corresponding to the second data of the first logical address, the controller further writes a first temporary block table into the temporary block.

Description

Electronic system with data storage device

The present invention relates to a data storage device, and more particularly to a data storage device for recovering data status from a self-power failure event.

Flash memory is a popular non-volatile data storage device that is electrically erased and programmed. For example, NAND FLASH, which is not a gate type, is often used as a memory card, a universal flash memory device, a solid state drive (SSD), and an embedded flash. Memory module (eMMC)...etc.

A flash memory (eg, NAND FLASH) storage array includes a plurality of blocks, wherein a floating gate transistor can be used to form a flash memory. A floating gate in a floating gate transistor that captures charge to store data. In addition, the conversion relationship between the physical page in the flash memory and the logical page specified by the host device requires a table to record. When an unexpected power outage event occurs, the table stored in random memory is lost. How to effectively reconstruct lost tables is an important issue.

The data storage device and the data maintenance method provided by the invention can independently store the system data in the temporary block, and the data of the same logical address is separated by the temporary block table as the valid data.

An embodiment provides an electronic system including a host And a data storage device controlled by the host.

The invention provides a data storage device comprising a flash memory and a controller. The flash memory includes a plurality of blocks, and the block includes a current block and a temporary block. The controller writes the first data corresponding to one of the first logical addresses into the current block, and determines whether the temporary block has the second data corresponding to one of the first logical addresses, where the temporary block has When corresponding to the second data of the first logical address, the controller further writes a first temporary block table into the temporary block.

In an embodiment, the first data is data indicated by one of the host write commands, or the first data is cold data in the temporary block. The first temporary block table records information about all pages in the temporary block.

In another embodiment, the controller releases the relationship between the second data and the logical address in a current temporary block table stored in a random access memory to update the current temporary block table. The controller uses the updated current temporary block table as the first temporary block table to write to one of the pages of the temporary block, wherein the specific page does not have the user profile.

In still another embodiment, each block includes a plurality of pages arranged in a first order. The controller is configured to determine, according to a second temporary block table stored in the Xth page in the temporary block, after the data storage device recovers from a power-off event, that the temporary block has the same logical address as the current block. The data is valid, and the Xth page is the last page written in the temporary block before the power-off event, and X is a positive integer. In addition, each page in the temporary block is used to store system data whose length is less than a predetermined length, and other materials except the system data are written into the current block, and each page is It has a user data space and a spare space. After the data storage device recovers from the power-off event, the controller uses a search program to obtain the Xth page, wherein in the search process, the controller starts from the first page in the temporary block, according to the first The spare space of a predetermined number of pages in the temporary block is sequentially read until the read spare space does not have valid data. After reading the spare space without valid data, the controller starts from the next page of the page corresponding to the spare space that does not have valid data, and reads the temporary block one by one according to a second order. The spare space of the page until the read spare space has valid data, wherein the controller reads the page to which the spare space having the valid data belongs according to the second order is a first blank page, and the second order is first The order is reversed. The controller further reads the user data space in the first blank page, and determines whether the user data space in the first blank page has valid data, so as to confirm that the first blank page is the first one in the temporary block. The page of the user data, wherein when the user data space in the first blank page has valid data, the controller further reads the user data space of the page in the temporary block one by one according to the first order from the first blank page. Until the read user data space does not have valid data, the page in which the user data space does not have valid data replaces the original first blank page to become the new first blank page. The controller further starts from the previous page of the first blank page or the previous page of the new first blank page, reads the user data space of the page in the temporary block one by one according to the second order, and judges that the read is performed. Whether the user space of the page has valid data, wherein the page corresponding to the user data space with valid data is read in reverse order, which is the last page in the temporary block with valid data, and is the Xth page.

The present invention further provides a data maintenance method, which is suitable for a data storage device having a flash memory, wherein the flash memory includes a plurality of blocks, and the block includes a current block and a temporary block. The data maintenance method includes: writing a first data corresponding to one of the first logical addresses to the current block; determining whether the temporary block has the second data corresponding to one of the first logical addresses; and when the temporary area When the block has the second data corresponding to the first logical address, a first temporary block table is written into the temporary block.

In one embodiment, the relationship between the second data and the logical address is released in one of the current temporary block tables stored in a random access memory to update the current temporary block table. The step of writing the first temporary block table into the temporary block further includes using the updated current temporary block table as the first temporary block table to write one of the pages of the temporary block, wherein the specific page The page does not have user data.

In another embodiment, each block includes a plurality of pages arranged in a first order. The data maintenance method further comprises: after the data storage device recovers from a power-off event, determining that the temporary block has the same logic as the current block according to a second temporary block table stored in the Xth page in the temporary block. The information of the address is the valid data, wherein the Xth page is the last page written in the temporary block before the power-off event, and X is a positive integer, and the Xth page is in the temporary block. The last page written before the power down event, and X is a positive integer. Each page in the temporary block is used to store system data having a length less than a predetermined length, and other data except the system data is written into the current block. In addition, each page has a user data space and a spare space, and the data maintenance method further includes self-powering in the data storage device. After the event is replied, use a search program to get the Xth page.

The searching program includes: starting from the first page in the temporary block, reading the spare space of the predetermined number of pages in the temporary block according to the first sequence until the read spare space does not have valid data; After reading the spare space without valid data, the backup space of the page in the temporary block is read one by one according to a second sequence starting from the next page of the page corresponding to the spare space that does not have valid data. Until the read spare space has valid data, wherein the page to which the spare space having the valid data belongs according to the second order belongs to a first blank page, and the second order is opposite to the first order; The blank page begins to read the user data space of the page in the temporary block one by one in the first order until the read user data space does not have valid data, and the user data space does not have valid data. The first blank page becomes the new first blank page; and the previous page from the first blank page or the new first blank Starting from the previous page of the page, the user data space of the page in the temporary block is read one by one according to the second order, and it is determined whether the user space of the read page has valid data, wherein the reverse reading is effective. The page corresponding to the user data space of the data is the last page in the temporary block with valid data, and is the Xth page.

100‧‧‧Electronic system

120‧‧‧Host

140‧‧‧Data storage device

160‧‧‧ Controller

162‧‧‧ arithmetic unit

164‧‧‧Permanent memory

166‧‧‧ random access memory

180‧‧‧Flash memory

P1~PN‧‧‧ page

B0~BN‧‧‧ Block

DAA1~DAAN‧‧‧ User Data Space

SPA1~SPAN‧‧‧ spare space

D1‧‧‧ first order

D2‧‧‧ second order

DA1~DA12‧‧‧Information

TP1~TP12‧‧‧ Temporary Block Table

SP1~SP12‧‧‧Backup data

S600~S604, S700~S702, S800~S806‧‧‧ steps

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram of one embodiment of an electronic system provided by the present invention.

Figure 2 is a block diagram of one embodiment of a flash memory provided by the present invention.

Figure 3 is a schematic illustration of one embodiment of a temporary block provided by the present invention.

Figure 4 is a schematic illustration of another embodiment of a temporary block provided by the present invention.

Figure 5 is a schematic diagram of another embodiment of a temporary block provided by the present invention.

Figure 6 is a flow chart of an embodiment of a data maintenance method provided by the present invention.

Figure 7 is a flow chart of another embodiment of a data maintenance method provided by the present invention.

Figure 8 is a flow diagram of one embodiment of a search procedure provided by the present invention.

The apparatus and method of use of various embodiments of the present invention are discussed in detail below. However, it is to be noted that many of the possible inventive concepts provided by the present invention can be implemented in various specific ranges. These specific examples are only intended to illustrate the apparatus and methods of use of the present invention, but are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram of one embodiment of an electronic system provided by the present invention. The electronic system 100 includes a host 120 and a data storage device 140. The data storage device 140 includes a flash memory 180 and a controller 160, and is operable according to commands issued by the host 120. The controller 160 includes an arithmetic unit 162, a permanent memory (e.g., read only memory ROM) 164, and a random access memory (RAM) 166. The permanent memory 164 and the stored code and data constitute a firmware, which is executed by the operation unit 162 to make the controller 160 base. The flash memory 180 is controlled by the firmware. Random access memory (RAM) 166 is used to load code and parameters to provide controller 160 to act upon the loaded code and parameters. The flash memory 180 includes a plurality of blocks, each of which includes a plurality of pages P1 to PN arranged in a first order D1, wherein each page P1 PN has a user data space DAA1~DAAN and a spare space ( Spare Area) SPA1~SPAN, as shown in Figure 2. It is worth noting that the flash memory 180 is erased in the smallest unit of the block, and the page is written in the smallest unit. In addition, the spare space SPA1~SPAN may be in front of or behind the corresponding page, and the present invention is not limited thereto. In other embodiments, the spare space SPA1~SPAN may also be located at the front end or the back end of the block B0~BN. It should be noted that in an embodiment, the spare space of each page having valid data includes the data of the page in which it is located, such as the corresponding logical address, data status, and the like.

In an embodiment, the controller 160 selects a usable block from the blocks B0 B BN of the flash memory 180 as a current block, and establishes an entity transfer in the random access memory 166. The logical correspondence table records the correspondence between the physical address of the page of the current block and the logical address of the page of the data. When the current block has been filled with the user data (when the new data cannot be written again), the controller 160 sorts the entity-to-logical correspondence table into a data link relationship table stored in the flash memory 180, and The current block is defined as a data parent block, and a usable block is selected from the blocks B0 to BN of the flash memory 180 as a new current block, and is established in the random access memory 166. The new entity-to-logic correspondence table records the correspondence between the physical address of the page of the new current block and the logical address of the page of the data.

However, in the user data written to the flash memory 180, Some types of data are repeatedly written to the same logical address, causing data previously in the same logical address to be invalidated. When the data parent block in the blocks B0~BN has too much invalid data, the controller 160 frequently performs the sorting work to release the available memory space. However, frequent finishing efforts can degrade the performance of the data storage device 140.

In view of this, in an embodiment, since the system data is usually repeatedly written to the same logical address, the controller 160 stores the system data in another block (temporary block). In addition, the controller 160 also creates a temporary block table in the random access memory 166 to record the correspondence between the physical address of the page of the temporary block and the logical address of the page of the data. It is worth noting that the temporary block table records information about all pages in the temporary block. In other words, all page address correspondences in the temporary block are recorded in the temporary block table.

In this embodiment, the flash memory 180 has a temporary block and a current block, wherein the temporary block is used to store system data, and the current block is used to store data other than system data. In other words, the user data space in each page in the temporary block is used to store system data whose length is less than a predetermined length, and other data except the system data is written into the user data space in the current block. It should be noted that the system data refers to the data written by the host 120 or the data storage device 140 to the flash memory 180 for operational requirements, and the system data also belongs to the user data. In one embodiment, the system data is less than a predetermined length. For example, in an embodiment, the length of the system data is less than 12K bytes, but the invention is not limited thereto. In other embodiments, the predetermined length may also be 9K bytes, 10K bytes, and 11K bits. Group, 13K bytes, 14K bytes, and so on. It should be noted that in this embodiment, the length of the system data is less than the length of the user data space in one page. In an embodiment, the size of the user data spaces DDA0~DDAN in each page P0~PN is 16K bytes, but the invention is not limited thereto. In addition, the controller 160 can determine whether the data to be written belongs to the system data according to the length of the data and the logical address corresponding to the data.

In some embodiments, the current block and the data in the temporary block will have duplicate logical addresses. For example, when the temporary block is filled, the controller 160 moves the data in the temporary block to the current block. In other words, the controller 160 invalidates the data in the temporary block and writes the data into the current block. It should be noted that, in an embodiment, the controller 160 moves the cold data in the temporary block to the current block, wherein the cold data is less (or least) read or updated in the temporary block. data. After the controller 160 writes the cold data to one of the pages of the current block, the controller 160 then modifies the current temporary block table in the random access memory 166 to release the page and logical address of the original stored cold data. Mapping relationship. In other words, the controller 160 invalidates the cold data in the temporary block and writes the cold data into the current block, wherein the cold data in the current block is valid data (latest data). However, although the mapping relationship between the logical address and the page storing the cold data is erased in the temporary block table, the cold data and its corresponding logical address are stored in the original page of the temporary block. In addition, the cold data and its corresponding logical address are also stored in one of the current blocks. In other words, the controller 160 needs to determine the data in the current block and the temporary block as valid data by randomly accessing the current temporary block table in the memory 166. In another embodiment, when the host The logical address of the data indicated by the write command of 120 is the same as the logical address of the data stored in any page in the temporary block, and when the data indicated by the write command is not the system data, the controller 160 writes the data. After entering the current block, the data in the temporary block will be invalid. In detail, after the controller 160 writes the data to one of the pages of the current block, the controller 160 then modifies the current temporary block table in the random access memory 166 to release the page and the duplicate of the original stored data. The logical address mapping relationship is such that the page corresponding to the logical address only has the latest data written in the current block as valid data. Similarly, although the mapping relationship between the logical address and the page of the original stored data is invalidated in the temporary block table, the invalidated data and its corresponding logical address are still stored in the temporary block. In the page. In addition, the new data and its corresponding logical address are also stored in one of the current blocks. Therefore, the controller 160 also needs to determine whether the data in the current block and the temporary block is valid data by using the current temporary block table in the random access memory 166.

When a power down event occurs, the entity-to-logical correspondence table and the temporary block table stored in the random access memory 166 are lost due to power loss. Therefore, after a power-off event occurs and the data storage device 140 resumes power, the controller 160 needs to sequentially read the temporary block and the page in the current block to re-establish a physical-to-logical correspondence in the random access memory 166. Table and temporary block table. However, the above method requires a long time to read a pair of all temporary blocks and pages in the current block, and requires a specific algorithm to discriminate the writing order of the data or the old and new.

In view of this, in an embodiment, since the length of the system data is smaller than the user data spaces DDA1 D DDAN, the controller 160 is in the temporary area. When the page in the block is written, the current temporary block table is also written into the page to back up the current temporary block table. In addition, when the controller 160 writes the first data corresponding to one of the first logical addresses to the current block, it is determined whether the temporary block has the second data corresponding to one of the first logical addresses. When there is a second material in the temporary block that also corresponds to the first logical address, the controller 160 also writes the latest temporary block table into the temporary block. In detail, in an embodiment, after the first data is written into the current block, the controller 160 releases the second data and logic in the current temporary block table stored in a random access memory 166. The relationship of the addresses to update the current temporary block table. Next, the controller 160 writes the updated current temporary block table to one of the specific pages in one of the temporary blocks. It is worth noting that the specific page written to the first temporary block table is any one of the blank pages in the temporary block, and the specific page is not written to other user data. For example, a particular page is the next page of the last page written in the temporary block. In addition, as described above, the first data may be the data indicated by the write command for one of the hosts 120, or the first data is the cold data in the temporary block.

Therefore, when the data storage device 140 recovers from the power-off event, the controller 160 can directly read the last page written in the temporary block before the power-off event occurs, and obtain the latest temporary block table, and The latest temporary block table is used to determine which data has the same logical address in the temporary block and the current block as valid data.

In detail, when the data storage device 140 replies from a power-off event, the controller 160 executes a seek program to obtain the X-th page in the temporary block, wherein the X-th page is in the temporary block and is powered off. The last one before the event was written Enter the page, and X is a positive integer. Next, the controller 160 loads one of the second temporary block tables stored in the Xth page into the random access memory 166 as the current temporary block table. In other words, the controller 160 may determine, according to the second temporary block table stored in the Xth page in the temporary block, which of the data having the same logical address in the current block and the current block is valid data.

In a search procedure of an embodiment, the controller 160 starts from the first page in the temporary block and reads the spare space of a predetermined number of pages in the temporary block according to the first sequence D1 until the read is performed. The spare space does not have valid data. After reading the spare space that does not have valid data, the controller 160 starts from the next page of the page corresponding to the spare space that does not have the valid data, and reads the temporary area one by one according to a second sequence D2. The spare space of the page in the block until the read spare space has valid data, wherein the controller 160 reads the page to which the spare space having the valid data belongs according to the second sequence D2 as a first blank page, and The second order D2 is opposite to the first order D1. After obtaining the first blank page, the controller 160 further reads the user data space in the first blank page, and determines whether the user data space in the first blank page has valid data to confirm that the first blank page is The first page in the temporary block that does not have user data. When the user data space in the first blank page has valid data, the controller 160 further reads the user data space of the page in the temporary block one by one according to the first sequence D1 from the first blank page until the read The user data space does not have valid data, and the page that reads the user data space without valid data replaces the original first blank page to become the new first blank page. Finally, the controller 160 is from the previous page of the first blank page or the previous page of the new first blank page. Starting from the beginning, the user data space of the page in the temporary block is read one by one according to the second sequence D2, and it is determined whether the user space of the read page has valid data to obtain the last write in the temporary block. The page, in which the page corresponding to the user data space with valid data is read in reverse order, is the last page in the temporary block with valid data (the Xth page).

Figure 3 is a schematic illustration of one embodiment of a temporary block provided by the present invention. In the present embodiment, the temporary block B2 has 17 pages P1 to P17 arranged in the first order D1, and the third figure shows the state of the pages P1 to P17 in the temporary block B2 after the power-off event occurs. In detail, the user data spaces DAA1 to DAA12 in the first to the twelfth pages P1 to P12 in the temporary block B2 have been written into the valid data (user data DA1 to DA12 and temporary block tables TP1 to TP12). ), and the backup spaces SP1 to SP12 in the first to the twelfth pages P1 to P12 have also been written into the valid data (backup data SP1 to SP12).

In the search procedure, the controller 160 first reads from the first page P1 in the temporary block B2, and reads the spare space of a predetermined number of pages in the temporary block according to the first sequence D1 until the read is read. Space does not have valid data. In the present embodiment, the predetermined number is 3, but the present invention is not limited thereto. In other words, the controller 160 first reads the spare space SPA1 of the first page P1 in the temporary block B2. Since the spare space SPA1 already has the valid data SP1, the controller 160 continues to read the spare space SPA5 of the fifth page P5 of the three pages spaced from the first page P1 in accordance with the direction of the first sequence D1. Since the spare space SPA5 already has the valid data SP5, the controller 160 continues to read the spare space SPA14 of the 14th page P14 of the 3 pages spaced from the fifth page P5 in accordance with the direction of the first sequence D1. Since the spare space SPA14 of page P14 does not have valid data, Therefore, the controller 160 stops reading the spare space of the predetermined number of pages in the temporary block B2 in accordance with the first sequence D1. After obtaining the page P14 of the spare space SPA14 without valid data, the controller 160 further reads from the 14th page P14, and reads the spare space of the page in the temporary block B2 one by one according to the second sequence D2 until the read Take the spare space with valid data. In other words, the controller 160 then reads the backup space SPA13 of the thirteenth page P13 before the 14th page P14 in accordance with the direction of the second sequence D2. Since the spare space SPA13 does not have valid material, the controller 160 continues to read the backup space SPA12 of the 12th page P12 before the 13th page P13 in the direction of the second sequence D2. Since the backup space SPA12 has the valid data SP12, the controller 160 stops reading the spare space of the page in the temporary block B2 one by one in accordance with the second order D2. It is worth noting that, so far, the controller 160 assumes that the 12th page P12 is the first blank page (first blank page) in the temporary block B2. Next, the controller 160 further reads the user data space DDA12 in the 12th page P12 (first blank page), and determines whether the user data space DDA12 in the 12th page P12 has valid data to confirm the 12th. The page P12 is the first page in the temporary block B2 that does not have user data. In this embodiment, since the user data space DDA12 of the 12th page P12 has the valid data DA12 and TP12. Therefore, the controller 160 determines that the 12th page P12 is not the first page in the temporary block B2 that does not have user data. Then, the controller 160 reads the user data space of the page in the temporary block B2 one by one according to the first sequence D1 from the next page of the 12th page P12 until the read user data space is not valid. Information up to now. In other words, the controller 160 first reads the user profile space DDA13 of the thirteenth page P13. User data The space DDA 13 does not have valid material, so the controller 160 replaces the original first blank page (page 12 P12) with the 13th page P13 as the new first blank page. In other words, the controller 160 confirms that the thirteenth page P13 is the page of the first blank in the temporary block B2. Finally, the controller 160 begins looking for the last page written in the temporary block B2. In other words, the controller 160 starts from one page (the 12th page P12) on the 13th page P13, and reads the user data space of the page in the temporary block B2 one by one according to the second sequence D2. In this embodiment, the user profile space DAA12 of the 12th page P12 has valid data DA12 and TP12. Therefore, the controller 160 obtains that the last page written in the temporary block B2 is the 12th page P12, and the 12th page P12 is the Xth page.

When the controller 160 determines that the 12th page P12 can be successfully read, the controller 160 loads the temporary block table TP12 stored in the 12th page P12 into the random access memory 166 as the current temporary. Block table. When the controller 160 successfully reads the 12th page P12 by using more than two read voltages, the controller 160 repeatedly writes the data DA12 and TP12 into the 12th page P12 to stabilize the 12th. The information in page P12. In addition, after the temporary block table TP12 is loaded into the random access memory 166 as the current temporary block table, the controller 160 is further configured to update the current temporary block table according to the current temporary block status, and the updated block table will be updated. The current temporary block table is written to the thirteenth page P13 in the temporary block B2.

When the controller 160 determines that the 12th page P12 cannot be successfully read, the controller 160 reads the 11th page P11 in the temporary block B2, and stores the temporary block table stored in the 11th page P11. The TP 11 is loaded into the random access memory 166 as the current temporary block table. In addition, the controller 160 is further used A new block (e.g., block B5) is selected to replace the original temporary block B2. In detail, when the 12th page P12 cannot be successfully read, the controller 160 discards the temporary block B2, selects the block B5 as a new temporary block, and sets the first block 11 of the temporary block B2. The data DA1~DA11 and TP1~TP11 stored in the pages P1~P11 are written in the temporary block B5.

Figure 4 is a schematic illustration of one embodiment of a temporary block provided by the present invention. In the present embodiment, the temporary block B2 has 17 pages P1 to P17 arranged in the first order D1, and FIG. 4 shows the state of the pages P1 to P17 in the temporary block B2 after the power-off event occurs. In detail, the user data spaces DAA1 to DAA11 in the first to eleventh pages P1 to P11 in the temporary block B2 have been written into the valid data (user data DA1 to DA11 and temporary block tables TP1 to TP11). ), and the backup spaces SP1 to SP12 in the first to the twelfth pages P1 to P12 have also been written into the valid data (backup data SP1 to SP12).

In the search procedure, the controller 160 first reads from the first page P1 in the temporary block B2, and reads the spare space of a predetermined number of pages in the temporary block according to the first sequence D1 until the read is read. Space does not have valid data. In the present embodiment, the predetermined number is 3, but the present invention is not limited thereto. In other words, the controller 160 first reads the spare space SPA1 of the first page P1 in the temporary block B2. Since the spare space SPA1 already has the valid data SP1, the controller 160 continues to read the spare space SPA5 of the fifth page P5 of the three pages spaced from the first page P1 in accordance with the direction of the first sequence D1. Since the spare space SPA5 already has the valid data SP5, the controller 160 continues to read the spare space SPA9 of the ninth page P9 of the three pages spaced from the fifth page P5 in accordance with the direction of the first sequence D1. Since the spare space SPA9 already has a valid data SP9, the controller 160 continues to read the spare space SPA14 of the 14th page P14 of the 3 pages spaced from the ninth page P9 in accordance with the direction of the first sequence D1. Since the spare space SPA14 of the page P14 does not have valid data, the controller 160 stops reading the spare space of the predetermined number of pages in the temporary block B2 in accordance with the first order D1. After obtaining the page P14 of the spare space SPA14 without valid data, the controller 160 further reads from the 14th page P14, and reads the spare space of the page in the temporary block B2 one by one according to the second sequence D2 until the read Take the spare space with valid data. In other words, the controller 160 then reads the backup space SPA13 of the thirteenth page P13 before the 14th page P14 in accordance with the direction of the second sequence D2. Since the spare space SPA13 does not have valid material, the controller 160 continues to read the backup space SPA12 of the 12th page P12 before the 13th page P13 in the direction of the second sequence D2. Since the backup space SPA12 has the valid data SP12, the controller 160 stops reading the spare space of the page in the temporary block B2 one by one in accordance with the second order D2. It is worth noting that, so far, the controller 160 assumes that the 12th page P12 is the first blank page (first blank page) in the temporary block B2. Next, the controller 160 further reads the user data space DDA12 in the 12th page P12 (first blank page), and determines whether the user data space DDA12 in the 12th page P12 has valid data to confirm the 12th. The page P12 is the first page in the temporary block B2 that does not have user data. In this embodiment, since the user data space DDA12 of the 12th page P12 does not have valid data. Therefore, the controller 160 determines that the 12th page P12 is the first page in the temporary block B2 that does not have user data. Finally, the controller 160 begins looking for the last page written in the temporary block B2. In other words, the controller 160 is one page above the 12th page P12 (11th page P11) Initially, the user data space of the page in the temporary block B2 is read one by one according to the second sequence D2. In this embodiment, the user profile space DAA11 of the eleventh page P11 has valid data DA11 and TP11. Therefore, the controller 160 obtains that the last page written in the temporary block B2 is the eleventh page P11, and the eleventh page P11 is the Xth page.

When the controller 160 determines that the eleventh page P11 can be successfully read, the controller 160 loads the temporary block table TP11 stored in the eleventh page P11 into the random access memory 166 as the current temporary. Block table. When the controller 160 successfully reads the eleventh page P11 by using more than two read voltages, the controller 160 repeatedly writes the data DA11 and TP11 into the eleventh page P11 to stabilize the eleventh. The information in page P11. In addition, after the temporary block table TP11 is loaded into the random access memory 166 as the current temporary block table, the controller 160 is further configured to update the current temporary block table according to the current temporary block status, and after updating The current temporary block table is written in the user profile space DAA12 of the 12th page P12 in the temporary block B2, and the backup data SP12 of the 12th page P12 is updated.

When the controller 160 determines that the eleventh page P11 cannot be successfully read, the controller 160 reads the tenth page P10 in the temporary block B2, and stores the temporary block table stored in the tenth page P10. The TP 10 is loaded into the random access memory 166 as the current temporary block table. In addition, the controller 160 is further configured to select a new block (for example, block B5) instead of the original temporary block B2. In detail, when the 11th page P11 cannot be successfully read, the controller 160 discards the temporary block B2, selects the block B5 as a new temporary block, and sets the first block 10 of the temporary block B2. The data DA1~DA10 stored in pages P1~P10 are And TP1~TP10 are written in the temporary block B5.

Figure 5 is a schematic diagram of an embodiment of a temporary block provided by the present invention. In the present embodiment, the temporary block B2 has 17 pages P1 to P17 arranged in the first order D1, and FIG. 5 shows the state of the pages P1 to P17 in the temporary block B2 after the power-off event occurs. In detail, the user data spaces DAA1 to DAA12 in the first to the twelfth pages P1 to P12 in the temporary block B2 have been written into the valid data (user data DA1 to DA12 and temporary block tables TP1 to TP12). ), and the backup spaces SP1 to SP11 in the first to eleventh pages P1 to P11 have also been written into the valid data (backup data SP1 to SP11).

In the search procedure, the controller 160 first reads from the first page P1 in the temporary block B2, and reads the spare space of a predetermined number of pages in the temporary block according to the first sequence D1 until the read is read. Space does not have valid data. In the present embodiment, the predetermined number is 3, but the present invention is not limited thereto. In other words, the controller 160 first reads the spare space SPA1 of the first page P1 in the temporary block B2. Since the spare space SPA1 already has the valid data SP1, the controller 160 continues to read the spare space SPA5 of the fifth page P5 of the three pages spaced from the first page P1 in accordance with the direction of the first sequence D1. Since the spare space SPA5 already has the valid data SP5, the controller 160 continues to read the spare space SPA9 of the ninth page P9 of the three pages spaced from the fifth page P5 in accordance with the direction of the first sequence D1. Since the spare space SPA9 already has the valid data SP9, the controller 160 continues to read the spare space SPA14 of the 14th page P14 of the 3 pages spaced apart from the ninth page P9 in accordance with the direction of the first sequence D1. Since the spare space SPA14 of the page P14 does not have valid data, the controller 160 stops reading the spare space of the predetermined number of pages in the temporary block B2 in accordance with the first order D1. in After obtaining the page P14 of the spare space SPA14 without valid data, the controller 160 further reads the spare space of the page in the temporary block B2 one by one according to the second sequence D2 until the read. The spare space has valid data. In other words, the controller 160 then reads the backup space SPA13 of the thirteenth page P13 before the 14th page P14 in accordance with the direction of the second sequence D2. Since the spare space SPA13 does not have valid material, the controller 160 continues to read the backup space SPA12 of the 12th page P12 before the 13th page P13 in the direction of the second sequence D2. Since the backup space SPA12 does not have the valid data SP12, the controller 160 continues to read the backup space SPA11 of the eleventh page P11 before the twelfth page P12 in the direction of the second sequence D2. Since the backup space SPA11 has the valid data SP11, the controller 160 stops reading the spare space of the page in the temporary block B2 one by one in accordance with the second order D2. It is worth noting that, so far, the controller 160 assumes that the eleventh page P11 is the first blank page (first blank page) in the temporary block B2. Next, the controller 160 further reads the user data space DDA11 in the eleventh page P11 (first blank page), and determines whether the user data space DDA11 in the eleventh page P11 has valid data to confirm the 11th. The page P11 is the first page in the temporary block B1 that does not have user data. In the present embodiment, since the user data space DDA11 of the eleventh page P11 has valid data DA11 and TP11. Therefore, the controller 160 determines that the eleventh page P11 is not the first page in the temporary block B2 that does not have user data. Then, the controller 160 reads the user data space of the page in the temporary block B2 one by one according to the first sequence D1 from the next page of the eleventh page P11 until the read user data space does not have valid. Information up to now. In other words, the controller 160 first reads Take the user data space DDA12 of the 12th page P12. Since the user data space DDA12 has the valid data DA12 and TP12, the controller 160 continues to read the user data space DDA13 of the thirteenth page P13. Since the user data space DDA13 does not have valid data, the controller 160 will be the 13th. The page P13 replaces the original first blank page (page 11 P11) to become the new first blank page. In other words, the controller 160 confirms that the thirteenth page P13 is the page of the first blank in the temporary block B2. Finally, the controller 160 begins looking for the last page written in the temporary block B2. In other words, the controller 160 starts from one page (the 12th page P12) on the 13th page P13, and reads the user data space of the page in the temporary block B2 one by one according to the second sequence D2. In this embodiment, the user profile space DAA12 of the 12th page P12 has valid data DA12 and TP12. Therefore, the controller 160 obtains that the last page written in the temporary block B2 is the 12th page P12, and the 12th page P12 is the Xth page.

Figure 6 is a flow chart of an embodiment of a data maintenance method provided by the present invention. The data maintenance method is applied to the data storage device 140 shown in FIG. 1 for writing data into the current block. The flow begins in step S600.

In step S600, the controller 160 writes the first data corresponding to one of the first logical addresses to the current block.

Next, in step S602, the controller 160 determines whether there is a second material in the temporary block that also corresponds to one of the first logical addresses. When the temporary block has the second material corresponding to the first logical address, the flow proceeds to step S604; otherwise, the flow ends at step S600.

In step S604, the controller 160 writes the latest temporary block table into the temporary block. In detail, in an embodiment, the controller 160 is storing In the current temporary block table in the random access memory 166, the relationship between the second data and the logical address is released to update the current temporary block table. Next, the controller 160 writes the updated current temporary block table to one of the specific pages in one of the temporary blocks. It is worth noting that the specific page written to the first temporary block table is any one of the blank pages in the temporary block, and the specific page is not written to other user data. For example, a particular page is the next page of the last page written in the temporary block. In an embodiment, when the logical address of the first material is repeatedly displayed in the temporary block, the first data may be the data indicated by the command written by one of the hosts 120, or the first data is a temporary block. The cold information in the middle. The flow ends in step S604.

Figure 7 is a flow chart of another embodiment of a data maintenance method provided by the present invention. The data maintenance method is applicable to the data storage device 140 shown in FIG. 1 for reconstructing the data state after a power failure event occurs in the data storage device 140 and the data storage device 140 recovers power. The flow begins in step S700.

In step S700, after the data storage device 140 generates a power-off event and the data storage device 140 resumes power, the controller 160 executes a seek program to obtain the X-th page in the temporary block, wherein the X-th page is temporary The last page written in the block before the power down event, and X is a positive integer.

Next, in step S702, the controller 160 loads one of the second temporary block tables stored in the Xth page into the random access memory 166 as the current temporary block table. It should be noted that the controller 160 may determine, according to the second temporary block table stored in the Xth page in the temporary block, which data has the same logical address in the current block as the valid data. The flow ends in step S702.

Figure 8 is a flow diagram of one embodiment of a search procedure provided by the present invention. The search program is applied to the data storage device 140 shown in FIG. 1 and the step S700 in FIG. 7 to find the last page to be written after the data storage device 140 recovers from the power-off event. The flow begins in step S800.

In step S800, the controller 160 starts from the first page in the temporary block, and reads the spare space of a predetermined number of pages in the temporary block according to the first sequence D1 until the read spare space is not read. Have valid data so far.

Next, in step S802, the controller 160 starts from the next page of the page corresponding to the spare space that does not have the valid data, and reads the spare space of the page in the temporary block one by one according to a second sequence D2. Until the read spare space has valid data, wherein the controller 160 reads the page to which the spare space having the valid data belongs according to the direction of the second sequence D2 is the first blank page assumed by the current controller 160, and The second sequence D2 is opposite to the first sequence D1.

Next, in step S804, the controller 160 starts the first blank page of the hypothesis, and reads the user data space of the page in the temporary block one by one according to the first sequence D1, so as to find that the first one of the temporary blocks does not have User profile page.

Next, the controller 160 starts from the previous page of the first page in the temporary block that does not have the user profile, and reads the user data space of the page in the temporary block one by one according to the second sequence D2, and judges that the read is performed. Whether the user space of the page has valid data to obtain the last written page in the temporary block, wherein the user data space with valid data is read in reverse order The corresponding page is the last page in the temporary block with valid data (Xth page).

The data storage device and the data maintenance method provided by the invention can independently store the system data in the temporary block, and the data of the same logical address is separated by the temporary block table as the valid data.

The method of the invention, or a particular type or portion thereof, may exist in the form of a code. The code can be stored in a physical medium such as a floppy disk, a CD, a hard disk, or any other machine readable (such as computer readable) storage medium, or is not limited to an external form of computer program product, wherein When the code is loaded and executed by a machine, such as a computer, the machine becomes a device for participating in the present invention. The code can also be transmitted via some transmission medium, such as a wire or cable, fiber optics, or any transmission type, where the machine becomes part of the program when it is received, loaded, and executed by a machine, such as a computer. Invented device. When implemented in a general purpose processing unit, the code combination processing unit provides a unique means of operation similar to application specific logic.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent. In addition, any of the objects or advantages or features of the present invention are not required to be achieved by any embodiment or application of the invention. In addition, the abstract sections and headings are only used to assist in the search of patent documents and are not intended to limit the scope of the invention.

Claims (12)

An electronic system comprising: a host; and a data storage device, operating according to a command issued by the host, comprising a flash memory and a controller, wherein: the flash memory comprises a plurality of blocks, and the The equal block includes a current block and a temporary block; the controller determines whether the temporary block has the same when writing the first data corresponding to one of the first logical addresses to the current block Corresponding to the second data of the first logical address; and the controller determines that the temporary data block has the second data corresponding to the first logical address, and further includes a first temporary block table Write to this temporary block. According to the electronic system of claim 1, wherein the first data is data indicated by one of the host write commands, or the first data is cold data in the temporary block. The electronic system of claim 1, wherein each of the blocks comprises a plurality of pages in which information of all of the pages in the temporary block is recorded. The electronic system of claim 1, wherein the controller is stored in a current temporary block table in a random access memory, and the relationship between the second data and the logical address is released to update the Currently the temporary block table. According to the electronic system of claim 4, wherein the controller system will be more The current current temporary block table is used as the first temporary block table to write to a specific page of the temporary block. An electronic system according to item 5 of the patent application, wherein the specific page does not have user data. The electronic system of claim 1, wherein each of the blocks comprises a plurality of pages arranged in a first order, wherein the controller is configured to: after the data storage device recovers from a power outage event, A second temporary block table stored in the Xth page of the temporary block determines whether the temporary block and the current logical block having the same logical address in the current block are valid data, wherein the Xth page Is the last page written in the temporary block before the power-down event, and X is a positive integer. An electronic system according to claim 7 wherein each of the pages in the temporary block is for storing system data having a length less than a predetermined length, and other materials other than the system data are written Currently in the block. According to the electronic system of claim 8, wherein each of the pages has a user data space and a spare space, and the controller is used to use the data storage device after the power failure event is restored. Searching for a program to obtain the Xth page, wherein in the finding program, the controller starts from the first page in the temporary block, and reads a predetermined number of intervals in the temporary block according to the first sequence The spare space of the pages until the spare space read does not have valid data. According to the electronic system of claim 9, wherein the controller reads from the spare space that does not have valid data, The next start of the page corresponding to the spare space of the valid data, and the spare spaces of the pages in the temporary block are read one by one according to a second sequence until the read spare space has valid data So far, the controller reads, according to the second sequence, the page to which the spare space having valid data belongs is a first blank page, and the second sequence is opposite to the first order. The electronic system of claim 10, wherein the controller further reads the user data space in the first blank page, and determines whether the user data space in the first blank page has valid data. To confirm that the first blank page is the first page in the temporary block that does not have user data, wherein when the user data space in the first blank page has valid data, the controller is further from the first a blank page begins to read the user data spaces of the pages in the temporary block one by one according to the first sequence until the read user data space does not have valid data, wherein the user data The page that does not have valid material in space replaces the original blank page to become the new first blank page. The electronic system of claim 11, wherein the controller further reads the temporary one by one according to the second page of the first blank page or the previous page of the new first blank page. The user data spaces of the pages in the block, and determining whether the user space of the page read has valid data, wherein the user data space with valid data is read in reverse order The page is the last page in the temporary block with valid data, and is the Xth page.