TWI425514B - A nand flash memory and method for updating data in the nand flash memory - Google Patents

Description

NAND flash memory and data update management method thereof

The invention relates to a NAND flash memory and a data update management method thereof.

At present, embedded systems using flash memory as a storage medium are widely used. Flash memory is a kind of non-volatile memory. The mainstream flash memory on the market can be divided into NOR flash memory and NAND flash memory according to the process. . Both types have their own advantages. NAND flash memory has faster erasing speed, larger capacity and lower price, so it is increasingly used in mobile terminals.

Each block in the NAND flash memory can only be allowed to write data once. When the data of the block in the NAND flash memory needs to be updated, the original data needs to be cleared, and then the new data is written. . When the data in the block in the NAND flash memory is emptied and the new data is not completely written, if the NAND flash memory has an unexpected terminal, the embedded system in the NAND flash memory cannot be started normally.

In view of the above, it is necessary to provide a NAND flash memory and a data update management method thereof. Each storage area of the NAND flash memory includes two headers of the same format, and the two headers are respectively stored in two In different blocks, when it is necessary to update the data in one block, the updated data is stored in another block, and if more When the new operation is unexpectedly interrupted, the NAND flash memory can use the data in the unupdated block to start the embedded system, improving the performance of the NAND flash memory.

A NAND flash memory, the NAND flash memory comprising two storage areas, each storage area comprising two headers of the same format, the two headers being respectively stored in two different blocks in the same storage area Each block also stores a mapping file, and the NAND flash memory includes: a reading module for reading a smaller header number from each storage area of the NAND flash memory. a header module, configured to identify, according to the mapped status flag in the read header, a storage area in which each header is located as a primary storage area or a secondary storage area; and a determination module for determining NAND Whether there is a main storage area in the flash memory, when there is a main storage area in the NAND flash memory, it is judged whether to update the data of the main storage area in the NAND flash memory; the update module is used when needed When the data of the main storage area in the NAND flash memory is updated, the data of the main storage area in the NAND flash memory is updated; the startup module is used when the main storage area exists in the NAND flash memory, according to In the main storage area The mapping file starts the embedded system in the NAND flash memory; the determining module is further configured to determine whether there is a secondary storage area in the NAND flash memory when the main storage area does not exist in the NAND flash memory; The startup module is further configured to start an embedded system in the NAND flash memory according to a mapping file in the secondary storage area when a secondary storage area exists in the NAND flash memory; the prompt module is used when the NAND is fast When there is neither a main storage area nor a secondary storage area in the flash memory, the user is prompted to fail to start the embedded system in the NAND flash memory.

A NAND flash memory data update management method, the NAND flash memory includes two storage areas, each storage area includes two headers of the same format, and the two headers are respectively stored in the same storage area. In different blocks, each block is also stored a mapping file, the method comprising the steps of: (a) reading a header containing a smaller header number from each storage area of the NAND flash memory; (b) mapping according to the read header a status flag that identifies whether the storage area in which each header is located is a primary storage area or a secondary storage area; (c) determines whether a primary storage area exists in the NAND flash memory; (d) exists in the NAND flash memory In the main storage area, it is judged whether the data of the main storage area in the NAND flash memory is updated, and when the data of the main storage area in the NAND flash memory needs to be updated, the main storage area in the NAND flash memory is used. The data is updated, and the embedded system in the NAND flash memory is started according to the mapping file in the main storage area; (e) when there is no main storage area in the NAND flash memory, it is judged whether the NAND flash memory is in the memory There is a secondary storage area. When there is a secondary storage area in the NAND flash memory, the embedded system in the NAND flash memory is activated according to the mapping file in the secondary storage area; (f) when in the NAND flash memory There is neither a main storage area nor a deposit When the secondary storage area, the user is prompted NAND flash memory in an embedded system fails to start.

Compared with the prior art, the present invention provides a NAND flash memory and a data update management method thereof. Each storage area of the NAND flash memory includes two headers of the same format, and the two headers are respectively Stored in two different blocks. When the data in one block needs to be updated, the updated data is stored in another block. If the data is accidentally interrupted during the update operation, the NAND flash memory is stored. The embedded system can be activated by using the data in the unupdated block to improve the performance of the NAND flash memory.

1‧‧‧NAND flash memory

100‧‧‧Read module

101‧‧‧ Identification module

102‧‧‧Judgement module

103‧‧‧Update Module

104‧‧‧Starting module

105‧‧‧ prompt module

1 is an application environment diagram of a preferred embodiment of a data update management method in a NAND flash memory of the present invention.

Figure 2 is a schematic illustration of the header of Figure 1.

FIG. 3 is a functional block diagram of the NAND flash memory in FIG. 1.

4 is a flow chart of a preferred embodiment of a method for updating data in a NAND flash memory of the present invention.

FIG. 5 is a specific flowchart of step S10 in FIG.

FIG. 6 is a specific flowchart of step S14 in FIG.

FIG. 1 is an application environment diagram of a preferred embodiment of a data update management method in a NAND flash memory of the present invention. This method is applied to the NAND flash memory 1. In this embodiment, the NAND flash memory 1 includes a storage area A and a storage area B, and the storage area A and the storage area B can respectively store data.

The storage area A comprises two headers A1 and a header A2 of the same format, the header A1 is placed in the block A1 of the storage area A, and the header A2 is placed in the block A2 of the storage area A . The block A1 also stores a mapping file A1, and the block A2 also stores a mapping file A2.

The storage area B includes two headers B1 and a header B2 of the same format, the header B1 is placed in the block B1 of the storage area B, and the header B2 is placed in the block B2 of the storage area B. . The block B1 also stores a mapping file B1, and the block B2 also stores a mapping file B2.

As shown in FIG. 2, it is a schematic diagram of the header in FIG. The header includes a checksum, a map status flag, and a header number. The check and the correctness of the mapping file used to identify the check and the header and the block in which the header is located, for example, if the header A1 includes the checksum A1, the check and A1 are used to identify the header A1. And the correctness of the mapping file A1. The map file status flag is used to indicate that the map file status flag is stored in the block The mapping file is the primary mapping file or the secondary mapping file. The header number can be represented by an Arabic numeral, for example: 1, 2, 3. The data stored in the block containing the smaller header number in the same storage area is the latest data. For example, if the header A1 contains a header number of 1, and the header A2 contains a header number of 2, then In the storage area A, the header A1 is a header containing a smaller header number, and the data stored in the header A1 is the latest data.

As shown in FIG. 3, it is a functional module diagram of the NAND flash memory 1 shown in FIG. 1. The NAND flash memory includes a reading module 100, an identification module 101, a determination module 102, an update module 103, a startup module 104, and a prompt module 105. The module referred to in the present invention is a computer program segment for performing a specific function, and is more suitable for describing the execution process of the software in the computer than the program. Therefore, the following description of the software is described in the module.

The reading module 100 is configured to read a header containing a smaller header number from each storage area of the NAND flash memory 1. For example, in the storage area A, if the header A1 includes a header number of 1, and the header A2 includes a header number of 2, the read module 100 reads the header from the storage area A as a header. A1.

The identification module 101 is configured to identify, according to the mapped status flag in the read header, whether the storage area where each header is located is a primary storage area or a secondary storage area. When the mapping file indicated by the mapping status flag in the read header is the primary mapping file, the identification module 101 identifies that the storage area where the read header is located is the primary storage area; when the read header is The mapping file indicated by the mapping status flag in the middle is a secondary mapping file, and the identification module 101 identifies that the storage area in which the read header is located is a secondary storage area.

The determining module 102 is configured to determine whether a main storage area exists in the NAND flash memory 1.

The determining module 102 is configured to determine whether to update the data of the main storage area in the NAND flash memory 1 when the main storage area exists in the NAND flash memory 1. In the embodiment, when the NAND flash memory 1 is powered on or the data in the NAND flash memory 1 is upgraded, the determining module 102 determines to update the data in the NAND flash memory 1.

The update module 103 is configured to update data of a main storage area in the NAND flash memory 1. For example, in the NAND flash memory 1, if the storage area A is the main storage area, the update module 103 updates the data in the storage area A.

The startup module 104 is configured to start the system according to the mapping file in the main storage area when the main storage area exists in the NAND flash memory 1.

The determining module 102 is further configured to determine whether there is a secondary storage area in the NAND flash memory 1 when there is no main storage area in the NAND flash memory 1.

The startup module 104 is further configured to start the system according to the mapping file in the secondary storage area when the secondary storage area exists in the NAND flash memory 1.

The prompting module 105 is configured to prompt the user system to fail to start when there is neither a primary storage area nor a secondary storage area in the NAND flash memory 1.

As shown in FIG. 4, it is a flowchart of a preferred embodiment of a data update management method in the NAND flash memory of the present invention.

In step S10, the reading module 100 reads a header containing a smaller header number from each storage area of the NAND flash memory 1.

In step S11, the identification module 101 identifies, according to the mapped status flag in the read header, whether the storage area where each header is located is a primary storage area or a secondary storage area. When read The mapping file indicated by the mapping status flag in the taken header is the primary mapping file, and the identification module 101 identifies that the storage area in which the read header is located is the primary storage area; when the mapping in the read header is The mapping file indicated by the file status flag is a secondary mapping file, and the identification module 101 identifies that the storage area in which the read header is located is a secondary storage area.

In step S12, the determining module 102 determines whether the main storage area exists in the NAND flash memory 1.

In step S13, when the main storage area exists in the NAND flash memory 1, the determination module 102 determines whether to update the data of the main storage area in the NAND flash memory 1.

In step S14, the update module 103 updates the data of the main storage area in the NAND flash memory 1. For example, in the NAND flash memory 1, if the storage area A is the main storage area, the update module 103 updates the data in the storage area A.

In step S15, the startup module 104 starts the system according to the mapping file in the main storage area.

In step S16, when there is no main storage area in the NAND flash memory 1, the determination module 102 determines whether there is a secondary storage area in the NAND flash memory 1.

In step S17, when there is a secondary storage area in the NAND flash memory 1, the startup module 104 starts the system according to the mapping file in the secondary storage area.

In step S18, when neither the main storage area nor the secondary storage area exists in the NAND flash memory 1, the prompting module 105 prompts the user that the system startup fails.

As shown in FIG. 5, it is a specific flowchart of step S10 in FIG.

In step S100, the reading module 100 respectively reads the checksums in the two headers of the same storage area, for example, the check and A1 in the header A1 of the storage area A, and the check and A2 in the header A2. .

In step S101, the reading module 100 determines whether the two checksums read are correct.

In step S102, when the two checksums read are correct, the reading module 100 reads the header containing the smaller header number.

In step S103, when the two checks and the incomplete readings are correct, the reading module 100 determines whether one of the two checksums read is correct.

In step S104, when the two checksums read are correct, the reading module 100 reads the header containing the correct checksum.

In step S105, when the two checksums read are not correct, the reading module 100 reports that the storage area is an invalid storage area.

As shown in FIG. 6, it is a specific flowchart of step S13 in FIG.

In this embodiment, the update map status flag is taken as an example for description.

In step S130, the update module 103 respectively reads the checksums in the two headers of the same storage area, for example, the checksum A1 in the header A1 of the storage area A, and the checksum A2 in the header A2.

In step S131, the update module 103 determines whether the two checksums read are correct. In step S132, when the two checksums read are correct, the update module 103 clears the data of the block containing the larger header number. In step S133, the update module 103 reads the header number and the map file from the block containing the smaller header number. In step S134, the update module 103 updates the read header number to a new header number. The new header number is a header number obtained by decrementing the read header number according to a preset decrement rule, for example, if the preset decrement rule is decremented each time. 1. If the number of the header to be read is 5, the new header number is 4. In step S135, the update module 103 obtains a new checksum according to the map status flag to be updated, the new header number, and the read map file. In step S136, the update module 103 writes the new header and the read map file to the cleared block. The new header includes: a map status flag to be updated, a new header number, and a new checksum. In step S137, the update module 103 clears the data in the block containing the smaller header number.

In step S138, when both of the read and the incomplete readings are correct, the update module 103 determines whether one of the two checksums read is correct. In step S139, when the two checksums read are correct, the update module 103 clears the data of the block containing the error checksum. In step S140, the update module 103 reads the header serial number and the mapping file of the block from the block containing the correct checksum. In step S141, the update module 103 updates the read header number to a new header number. In step S142, the update module 103 obtains a new checksum according to the map status flag to be updated, the new header number, and the read map file. In step S143, the update module 103 writes the new header and the read map file to the cleared block. The new header includes: a map status flag to be updated, a new header number, and a new checksum. In step S144, the update module 103 clears the data in the block containing the correct checksum.

Step S145, when the two checksums that are read are all incorrect, the update module 103 reads the map file stored in the first block, where the first block refers to the first position in the storage area. Block. In step S146, the update module 103 sets the header number of the block to an initial preset value. In step S147, the update module 103 obtains a new checksum according to the map state flag to be updated, the set header number, and the read map file. In step S148, the update module 103 clears the data in the second block, and the second block refers to the second block in the storage area. Step S149, update Module 103 writes the new header and the read map file to the second block. In step S150, the update module 103 clears the data in the first block.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and equivalent modifications or variations made by those skilled in the art in light of the spirit of the present invention are It should be covered by the following patent application.

1‧‧‧NAND flash memory

100‧‧‧Read module

101‧‧‧ Identification module

102‧‧‧Judgement module

103‧‧‧Update Module

104‧‧‧Starting module

105‧‧‧ prompt module

Claims (8)

A NAND flash memory data update management method, the NAND flash memory includes two storage areas, wherein each storage area includes two headers of the same format, and the two headers are respectively stored in the same storage area Each of the two different blocks also stores a mapping file. The method includes the following steps: (a) reading a label containing a smaller header number from each storage area of the NAND flash memory. a header, wherein the step (a) further comprises: respectively reading a checksum in two headers of the same storage area; determining whether the two checksums read are correct; when the two checks are read When both are correct, the header containing the smaller header number is read; when the two checks and the incomplete readings are correct, it is judged whether one of the two checks read is correct; when the read is When both checks and one is correct, the header containing the correct checksum is read; when the two checks that are read are all incorrect, the storage area is returned as an invalid storage area; (b) according to the read Map status flag in the header, identifying each header Whether the storage area is a primary storage area or a secondary storage area; (c) determining whether there is a primary storage area in the NAND flash memory; (d) determining whether the NAND is fast when there is a main storage area in the NAND flash memory The data of the main storage area in the flash memory is updated. When the data of the main storage area in the NAND flash memory needs to be updated, the data of the main storage area in the NAND flash memory is updated, and according to the main storage area. The mapping file in the file starts the embedded system in the NAND flash memory; (e) when there is no main storage area in the NAND flash memory, it is judged whether there is a secondary storage area in the NAND flash memory, when the NAND flashes When there is a secondary storage area in the memory, according to The mapping file in the secondary storage area starts the embedded system in the NAND flash memory; (f) prompts the user NAND flash memory when there is neither the main storage area nor the secondary storage area in the NAND flash memory The embedded system in the body failed to start. The NAND flash memory data update management method of claim 1, wherein the step (b) specifically includes: when the mapped header status flag in the read header indicates that the mapping file is the primary Mapping a file, identifying a block in which the read header is located as a primary storage area; and when the mapped status flag in the read header indicates that the mapped file is a secondary mapped file, identifying the read header The block is the secondary storage area. The NAND flash memory data update management method according to the first aspect of the invention, wherein the step of updating the data of the main storage area in the NAND flash memory comprises: reading two of the main storage areas. Checking in the block; determining whether the two checks read are correct; when both checksums read are correct, clearing the data in the block containing the larger header number will be updated The data is written to the emptied block together with the unaltered data in the block containing the smaller header number; when the two checks and incomplete readings are correct, it is judged whether there is one of the two checks read. Correctly, when the two checksums read are correct, the data of the block containing the error checksum is emptied, and the updated data is written together with the unaltered data in the block containing the correct checksum. Block; when the two checks that are read are all incorrect, the data in the second block is cleared, and the second block refers to the second block in the storage area, and the updated data will be updated. And unchanged in the first block Write data to the empty block with the first block refers to the first sorting position in the block storage area. The NAND flash memory data update management method according to claim 3, wherein The new header number refers to a header number obtained by decrementing the read header number according to a preset decrement rule. A NAND flash memory, the NAND flash memory comprising two storage areas, each storage area comprising two headers of the same format, the two headers being respectively stored in two different blocks in the same storage area Each block also stores a mapping file, and the NAND flash memory includes: a reading module for reading a smaller header number from each storage area of the NAND flash memory. a header, wherein the read module reads a header containing a smaller header number when both of the read checks are correct; when the two checksums read are correct, Reads the header containing the correct checksum; returns the storage area as invalid when the two checks are not correct; the recognition module is used to map based on the header read The status flag identifies whether the storage area where each header is located is a primary storage area or a secondary storage area; the determination module is configured to determine whether a primary storage area exists in the NAND flash memory, and exists in the NAND flash memory. When judging the main storage area, determine whether it is the main NAND flash memory Update the data of the storage area; update the module to update the data of the main storage area in the NAND flash memory when the data of the main storage area in the NAND flash memory needs to be updated; the startup module When the main storage area exists in the NAND flash memory, the embedded system in the NAND flash memory is started according to the mapping file in the main storage area; the determining module is also used in the NAND flash memory. When there is no main storage area, it is judged whether there is a secondary storage area in the NAND flash memory; the startup module is further used when the secondary storage area exists in the NAND flash memory, according to the secondary storage area The mapping file starts the embedded system in the NAND flash memory; the prompting module is used to prompt the user to embed the NAND flash memory when there is neither the main storage area nor the secondary storage area in the NAND flash memory. The system failed to start. The NAND flash memory of claim 5, wherein the identification module is configured to: when the mapped file status flag in the read header indicates that the mapping file is a primary mapping file, the identification is read. The block in which the header is located is the primary storage area; when the mapped status flag in the read header indicates that the mapping file is a secondary mapping file, the block in which the read header is located is identified as a secondary storage. Area. The NAND flash memory of claim 5, wherein the update module is configured to clear a block containing a larger header number when both of the read checks are correct. Data, the updated data and the unaltered data in the block containing the smaller header number are written into the cleared block; when the two checks and incomplete readings are correct, the two read are judged. Check if there is a correct one. When the two checks read and one are correct, clear the data of the block containing the error check and the updated data together with the unchanged data in the block containing the correct checksum. Write the cleared block; when the two checksums read are not correct, the data in the second block is cleared, and the second block refers to the second block in the storage area. And updating the updated data together with the unchanging data in the first block, where the first block refers to the first ranked block in the storage area. The NAND flash memory according to claim 7, wherein the new header number refers to a header number obtained by decrementing the read header number according to a preset decrement rule.