CN117912524A - Nor Flash and erasing method and erasing system thereof - Google Patents

Abstract

The present disclosure provides a Nor Flash, an erasing method and an erasing system thereof, wherein the Nor Flash includes a plurality of initial memory cells and a first preset memory area which is not lost when power is turned off, the first preset memory area is used for storing identification information corresponding to the initial memory cells to be refreshed, and the erasing method includes: after receiving the erasing instruction, determining and controlling to execute the erasing operation on the first storage unit based on the erasing instruction, determining and controlling to execute the page refreshing operation on the second storage unit corresponding to the identification information based on the erasing instruction and the identification information in the first preset storage area, and updating the identification information in the first preset storage area to be the identification information corresponding to the next initial storage unit to be refreshed in sequence after the page refreshing operation is completed. The method and the device can ensure that all unselected pages have the opportunity to be refreshed under the condition that the erasing time standard is not exceeded, and adopt a power-off protection design when the pages are refreshed, so that the reliability and the service life of the nonvolatile memory are improved.

Description

Nor Flash and erasing method and erasing system thereof

Technical Field

The present disclosure relates to the field of nonvolatile memories, and in particular, to a Nor Flash (a nonvolatile memory), and an erasing method and an erasing system thereof.

Background

A memory array of a memory is composed of a plurality of WLs (word lines) (e.g., 256 word lines or 512 word lines or even 1024 word lines) and a plurality of BLs (bit lines) (e.g., 2048 bit lines or 4096 bit lines or even 8192 bit lines). For low cost memory products, it is a common practice to use a larger PB (Physical Bank) for reducing the size of the external X and Y direction decoding circuits. In addition, maximizing the ARRAY WELL (array wells) and ARRAY WELL sharing the X and Y direction decoder drive circuits to reduce the spacing between the wells can also further reduce the size of the physical memory array.

However, some types of nonvolatile memory (e.g., charge trapping memory-SONOS) require high FN (field emission characteristics, also known as Fowler-Nordheim tunneling) program and erase voltages to move charge into and out of an ONO (oxide-nitride-oxide) barrier. In a page mode storage array, programs and erases are typically performed on a selected page. The transfer of high program voltages through longer word lines and longer bit lines to page program a selected page can cause disturbances to the data in unselected page memory. Multiple program erase cycles for selected pages can result in more serious interference for unselected pages. In addition to program disturb bits, the data retention time of the charge trapping memory is reduced.

For the problem of program disturb bits, the prior art has adopted the approach of selecting one as a refresh address in the unselected erase areas by generating a random number each time an erase command is executed. This scheme cannot guarantee 100% that all unselected data has the opportunity to be effectively refreshed, and thus cannot avoid data loss due to interference. This is because refresh depends on the randomness of the random number generator, which is not easy to implement by hardware silicon chip design. In addition, the cost of testing silicon chip randomness is also relatively expensive.

Therefore, for a storage class product of a larger size PB applied to a frequent power-on/power-off scenario, a solution capable of solving the problem of program interference bits to improve the reliability and data retention time of the nonvolatile memory is urgently needed.

Disclosure of Invention

The technical problem to be solved by the present disclosure is to overcome the defect that in the prior art, when a nonvolatile memory is applied to frequently power-on/power-off scenes to perform page program erase, the unselected pages are interfered, so that the data stored in the unselected pages are unreliable, and the storage time of the memory data is shortened.

The technical problems are solved by the following technical scheme:

according to a first aspect of the present disclosure, there is provided an erasing method of a Nor Flash, where the Nor Flash includes a plurality of initial storage units and a first preset storage area that is not lost when power is turned off, each initial storage unit includes a plurality of pages, each initial storage unit has corresponding identification information, and the first preset storage area is used to store the identification information corresponding to the initial storage unit to be refreshed;

The erasing method comprises the following steps:

after each time an erasure instruction is received, determining a first storage unit to be erased in a plurality of initial storage units based on the erasure instruction, and controlling the first storage unit to be erased;

Determining the initial storage unit to be refreshed corresponding to the identification information as a second storage unit based on the erasing instruction and the identification information in the first preset storage area;

and executing page refreshing operation on the second memory unit, and after the page refreshing operation on the second memory unit is completed, updating the identification information in the first preset memory area to the identification information corresponding to the initial memory unit to be refreshed next in sequence.

Preferably, the Nor Flash further comprises a second preset storage area and a third preset storage area, wherein the second preset storage area and the third preset storage area are not lost when power is lost, and the third preset storage area is used for storing a page address and a backup identifier;

The step of performing a page refresh operation on the second memory cell includes:

acquiring a target page to be refreshed in the second memory unit;

Judging whether the current target page needs to carry out page refreshing operation or not;

If the current target page does not need to be subjected to page refreshing operation, judging whether the current target page is the last target page to be refreshed in the second storage unit, if not, acquiring the next target page to be refreshed in the second storage unit, and returning to the step of executing the step of judging whether the current target page needs to be subjected to page refreshing operation;

If the current target page needs to be subjected to page refreshing operation, writing corresponding initial storage data in the current target page into the second preset storage area, writing a page address corresponding to the current target page and a backup identifier into the third preset storage area, executing page refreshing operation on the current target page, judging whether the current target page is the last target page to be refreshed in the second storage unit after finishing the page refreshing operation on the current target page, if not, acquiring the next target page to be refreshed in the second storage unit, and returning to the step of executing the step of judging whether the current target page needs to be subjected to page refreshing operation.

Preferably, the step of acquiring the target page to be refreshed in the second memory cell includes:

Reading the backup identifier in the third preset storage area;

Judging whether backup data exists in the second preset storage area or not based on the backup identifier;

if not, taking the first target page in the second storage unit as the current target page;

If yes, the page address in the third preset storage area is read as the current target page.

Preferably, after determining that the page refreshing operation on the second memory cell is completed, before the updating the identification information in the first preset memory area to the identification information corresponding to the initial memory cell to be refreshed in sequence, the erasing method further includes:

and erasing the stored data in the second preset storage area and the third preset storage area.

Preferably, the step of determining whether the current target page needs to perform a page refresh operation includes:

Reading corresponding initial storage data in the current target page by adopting a preset acquisition mode to obtain first storage data, and writing the first storage data into a page buffer area;

reading the corresponding initial storage data in the current target page by adopting a preset edge bias condition to obtain second storage data;

Judging whether the first storage data is consistent with the second storage data or not;

if the target pages are consistent, determining that the current target pages do not need to be subjected to page refreshing operation;

if the target pages are inconsistent, determining that the current target pages need to be subjected to page refreshing operation.

Preferably, after the step of reading the page address in the third preset storage area as the current target page, before the step of determining whether the current target page needs to perform a page refresh operation, the erasing method further includes:

And reading the first storage data in the second preset storage area, and writing the current target page.

Preferably, the initial storage unit comprises a sector, a half block or a full block;

and/or the number of the groups of groups,

The identification information is the number or address of the initial storage unit.

Preferably, the Nor flash is an ETOX flash (Erasable Tunnel Oxide Flash ) or SONOS flash (silicon-oxide-nitride-oxide-silicon flash, charge trapping memory).

According to a second aspect of the present disclosure, an erasing system of a Nor Flash is provided, where the Nor Flash includes a plurality of initial memory units and a first preset memory area that is not lost when power is turned off, each initial memory unit includes a plurality of pages, each initial memory unit has corresponding identification information, and the first preset memory area is used to store the identification information corresponding to the initial memory unit to be refreshed;

The erasing system comprises an erasing module, a determining module and a page refreshing module;

The erasing module is used for determining a first storage unit to be erased in a plurality of initial storage units based on the erasing instruction after each time of receiving the erasing instruction, and controlling the first storage unit to be erased;

the determining module is configured to determine, based on the erase instruction and the identification information in the first preset storage area, that the initial storage unit to be refreshed corresponding to the identification information is a second storage unit;

the page refreshing module is used for executing page refreshing operation on the second storage unit, and updating the identification information in the first preset storage area to the identification information corresponding to the initial storage unit to be refreshed next in sequence after the page refreshing operation on the second storage unit is completed.

According to a third aspect of the present disclosure, there is provided a Nor Flash implemented using the method for erasing Nor Flash described in the first aspect of the present disclosure.

The positive progress effect of the present disclosure is: by adding the page refreshing operation flow in the erasing process and storing the identification information corresponding to the initial storage unit to be refreshed by utilizing the first preset storage area which is not lost when power is lost, all unselected pages can be ensured to have the opportunity to be refreshed under the condition that the erasing time standard is not exceeded, and the reliability and the service life of the nonvolatile memory can be effectively improved.

In addition, the second preset storage area and the third storage area which are not lost when power failure is utilized to realize power failure protection when the pages are refreshed, so that the situation that data stored in unselected pages are damaged due to power failure in the process of erasing operation is effectively avoided, and the reliability and the service life of the nonvolatile memory are further improved.

Drawings

FIG. 1 is a first flowchart of an erase method of Nor Flash in embodiment 1 of the present disclosure;

FIG. 2 is a second flowchart of an erase method of Nor Flash in embodiment 1 of the present disclosure;

FIG. 3 is a third flowchart of an erase method of Nor Flash in embodiment 1 of the present disclosure;

FIG. 4 is a fourth flowchart of an erase method of Nor Flash in embodiment 1 of the present disclosure;

FIG. 5 is a diagram of Nor Flash disturbed bits in embodiment 1 of the present disclosure;

fig. 6 is a block diagram of an erase system of a Nor Flash in embodiment 2 of the present disclosure.

Detailed Description

The present disclosure is further illustrated by way of examples below, but is not thereby limited to the scope of the examples described.

Example 1

In a specific embodiment of the present disclosure, an erasing method of a Nor Flash is provided, where the Nor Flash includes a plurality of initial storage units and a first preset storage area that is not lost when power is off, each initial storage unit includes a plurality of pages, each initial storage unit has corresponding identification information, and the first preset storage area is used for storing the identification information corresponding to the initial storage unit to be refreshed;

As shown in fig. 1, the erasing method includes:

s1, after each time an erasure instruction is received, determining a first storage unit to be erased in a plurality of initial storage units based on the erasure instruction, and controlling the first storage unit to be erased;

S2, determining an initial storage unit to be refreshed, which corresponds to the identification information, as a second storage unit based on the erasing instruction and the identification information in the first preset storage area;

S3, performing page refreshing operation on the second storage unit, and after the page refreshing operation on the second storage unit is completed, updating the identification information in the first preset storage area to the identification information corresponding to the next initial storage unit to be refreshed in sequence.

Specifically, the Nor Flash in this embodiment may be ETOX Flash or SONOS Flash, etc. The initial memory unit in the Nor Flash may be sector, half block or full block, and for example, a Nor Flash with a capacity of 256Mb generally includes 512 blocks, 16 sectors per block, and 8 pages per sector. Typically one page is 256Bytes, one sector is 4K Bytes, one half block is 32K Bytes, and one block is 64K Bytes. The erase (erase operation) of the Nor Flash is usually performed on a designated storage area, for example, sector erase, half-block erase, or block erase (full block erase).

In a specific embodiment, after receiving the erase instruction, step S1 may determine an initial storage unit of the to-be-erased according to the erase instruction, for example, the erase instruction is a sector erase, indicates that the sector10 (10 th sector) is to be subjected to the erase, and may determine that the first storage unit is the sector10, and control to execute the erase on the sector 10.

In order to ensure that all the unselected storage areas have the opportunity to be refreshed in the process of executing the erase, the identification information corresponding to the initial storage unit of the next to-be-refreshed is specifically stored in the first preset storage area which is not lost in power failure in a manner of sequentially and alternately refreshing the storage areas, so that the storage area for executing PAGE REFRESH (page refreshing operation) is determined according to the identification information of the first preset storage area in the process of executing the erase. For example, for a sector erase command, if the address of the erase is hexadecimal 0xFF0000, that is, 4080 th sector of the whole Nor Flash chip, the identification information may be stored as corresponding number 4080, or may be specific address 0xFF0000, so long as the storage area to be refreshed can be uniquely identified; for the Block erase command, if the address of the erase is hexadecimal 0xFF0000, that is, 255 th Block of the whole Nor Flash chip, the identification information may be stored as corresponding number 255, or may be specific address 0XFF0000.

Step S2 may determine an initial storage unit to be refreshed according to the erase instruction and the identification information in the first preset storage area, for example, the identification information in the first preset storage area is the number or the address of the sector14, and then determine that the second storage unit executing PAGE REFRESH is the sector14 according to the identification information.

Next, in the process of controlling the execution of the erase on the sector10, PAGE REFRESH is executed on the second storage unit through step S3, and after the completion of PAGE REFRESH on the second storage unit, the identification information in the first preset storage area is updated to the identification information corresponding to the initial storage unit to be refreshed next in turn. For example, after PAGE REFRESH for sector14 is completed, the identification information in the first preset storage area is updated to the number or address corresponding to sector15, so that PAGE REFRESH for sector15 is executed when an erase instruction is received next time, and so on, so that it can be ensured that all sectors have an opportunity to be effectively processed PAGE REFRESH. Because the power failure of the first preset storage area is not lost, even if the Nor Flash is abnormally powered off, the area which acquires the last refresh from the first preset storage area can be continuously and sequentially refreshed when the power-on is recovered, so that all areas of the Nor Flash are guaranteed to have the opportunity to be refreshed.

The method for updating the identification information in the first preset storage area may be a method of sequentially increasing based on the number or the address, or may be another method capable of sequentially polling, which is not limited in this embodiment.

It should be noted that, in some specific cases, for example, the erase instruction indicates that the erase is performed on the sector10, the identification information in the first preset storage area is the number or the address of the sector10, and at this time, PAGE REFRESH of the execution of the erase on the sector10 may be directly determined to be completed, the identification information in the first preset storage area may be updated to be the number or the address corresponding to the sector11, or the identification information in the first preset storage area may be directly updated to be the number or the address corresponding to the sector11, and then PAGE REFRESH of the sector11 may be executed in the execution of the erase on the sector10, which is not limited in this embodiment.

Of course, the initial storage unit may be a block, for example, the erase instruction indicates that the erase is performed on the block10, it may be determined that the first storage unit is the block10, the identification information in the first preset storage area is the number or the address of the block14, it may be determined that the second storage unit executing PAGE REFRESH is the block14 according to the identification information, and after PAGE REFRESH on the block14 is completed, the identification information in the first preset storage area is updated to the number or the address corresponding to the block 15. The initial storage unit may also be half-block, PAGE REFRESH as above.

In a specific implementation manner, numbers or addresses corresponding to the sector, the half-block and the block of the to-be-refreshed may be set in the first preset storage area, or three first preset storage areas may be set to store numbers or addresses corresponding to the sector, the half-block and the block of the to-be-refreshed, so as to determine corresponding erase areas according to different erase instructions, which is not limited in this embodiment.

According to the specific embodiment, the identification information corresponding to the initial storage units to be refreshed is stored in the first preset storage area which is not lost when power is lost, and after PAGE REFRESH is completed, the identification information corresponding to the first preset storage area is updated to be the identification information corresponding to the next initial storage units to be refreshed in sequence, so that the fact that all the initial storage units have the opportunity to be effectively subjected to PAGE REFRESH is ensured even if abnormal power failure occurs. Meanwhile, since refresh is generally faster than the erase, by performing refresh on another area having the same size as the erase area in the process of executing the erase, it is possible to ensure that PAGE REFRESH is performed without exceeding the erase time specification, so that refresh on the storage area is completed without perception by the user, and the user experience is improved while ensuring data reliability.

In a specific implementation of the disclosure, the Nor Flash further includes a second preset storage area and a third preset storage area, the second preset storage area and the third preset storage area not losing power down, and the third preset storage area is used for storing a page address (PAGE ADDRESS) and a backup identifier;

as shown in fig. 2, the process of performing the page refresh operation on the second memory cell in step S3 includes:

s31, acquiring a target page to be refreshed in a second memory cell;

S32, judging whether the current target page needs to be subjected to page refreshing operation or not; if yes, go to step S33, otherwise, go to step S36;

S33, writing the corresponding initial storage data in the current target page into a second preset storage area;

S34, writing a page address corresponding to the current target page and a backup identifier into a third preset storage area;

s35, executing page refreshing operation on the current target page, and entering step S36 after finishing the page refreshing operation on the current target page;

S36, judging whether the current target page is the last target page to be refreshed in the second memory unit, if not, entering a step S37, and if so, entering a step S38;

s37, acquiring a next target page to be refreshed in the second memory unit, and returning to the step S32;

s38, the page refreshing operation of the second memory cell is finished.

Specifically, in order to avoid the loss of stored data in the refresh area caused by sudden power failure in the refresh process, in this embodiment, a second preset storage area and a third preset storage area are provided, where the second preset storage area is used to store data stored in a page executing PAGE REFRESH, and the third preset storage area is used to store a page address and a backup identifier corresponding to the page executing PAGE REFRESH, and whether valid backup data is stored in the second preset storage area is determined by using the backup identifier. The size of the second preset storage area is at least one Page, in this embodiment, 256Bytes, and is used for storing the initial storage data to be REFRESH PAGE, and the size of the third preset storage area is determined according to the bit length corresponding to the number of Page addresses and the bit width of the backup identifier, and in this embodiment, the Page address is set to 24-bit, and the backup identifier of 1-bit is added.

Since the second storage unit includes a plurality of pages, when PAGE REFRESH of the second storage unit is executed sequentially according to the pages, it is necessary to detect whether each page in the second storage unit has an interfered bit, and if the second storage unit has the interfered bit, PAGE REFRESH is required to be performed on the page to ensure the reliability of the data stored by the page.

Therefore, the target page to be refreshed in the second storage unit may be obtained through step S31, and whether the current target page needs to be performed PAGE REFRESH is determined through step S32, for example, if the first page in the second storage unit is taken as the current target page, whether the first page has the interfered bits is determined, if the interfered bits exist, PAGE REFRESH is needed to ensure the reliability of the data, and if the interfered bits do not exist, it is indicated that the page is not interfered, and PAGE REFRESH is not needed.

When it is determined that the current target page has the disturbed bits, in order to avoid the loss of the stored data caused by sudden power-off in the process of performing PAGE REFRESH on the current target page, before performing PAGE REFRESH, the corresponding initial stored data in the current target page is written into the second preset storage area through step S33, after the writing operation is completed, the page address and the backup identifier corresponding to the current target page are written into the third preset storage area through step S34, so as to determine which page the data stored in the second preset storage area is the data of, and determine whether the backup data is stored in the second preset storage area through the backup identifier.

In this embodiment, whether backup data is stored in the second preset storage area is determined by the 1-bit backup identifier, so that whether the refresh operation of the last erase operation is not completed PAGE REFRESH can be effectively identified, if yes, it is not necessary to restart PAGE REFRESH from the first page of the to-be-refreshed storage area, but only by starting PAGE REFRESH from the page stored in the second preset storage area, which is not lost when power is lost, thereby improving the data processing speed.

After the backup of the initial storage data and the corresponding page address of the current target page is completed, the current target page may be executed PAGE REFRESH in step S35, and after PAGE REFRESH of the current target page is completed, step S36 is entered to determine whether the current target page is the last target page to be refreshed in the second storage unit, if not, step S37 is entered to continue to obtain the next target page to be refreshed in the second storage unit, and then step S32 is returned to perform the cycle; if yes, step S38 is performed, where it is determined that PAGE REFRESH to the second memory unit is completed, that is, the page refresh operation to the second memory unit for the current erase command is completed.

In this embodiment, the second preset storage area and the third preset storage area, which are not lost when power is lost, are set to store the initial storage data of the page to be refreshed and the corresponding page address respectively, so as to avoid the problem of data loss caused by sudden power failure in the PAGE REFRESH process, and ensure the reliability of PAGE REFRESH.

In a specific embodiment of the disclosure, as shown in fig. 3, step S31 includes:

S311, reading a backup identifier in a third preset storage area;

S312, whether valid backup data exist in a second preset storage area based on the backup identifier Fu Panduan; if not, go to step S313; if yes, go to step S314;

s313, taking the first target page in the second storage unit as a current target page;

S314, reading the page address in the third preset storage area as the current target page.

Specifically, since there may be a sudden power-off condition during execution PAGE REFRESH on the second storage unit, the partial page in the second storage unit is already executed PAGE REFRESH, for example, during execution PAGE REFRESH on sector14, when page3 is executed, because PAGE REFRESH is required by the interfered bits in page3, the data stored in page3 and the corresponding page address are backed up to the second preset storage area and the third preset storage area respectively, and when page5 is executed, the sudden power-off is performed, at this time, pages 0-4 have already completed PAGE REFRESH, and pages 5-7 have not yet been executed PAGE REFRESH.

When the power is on again, whether valid backup data exists in the second preset storage area can be directly determined according to the backup identifier, if yes, it is indicated that PAGE REFRESH is not finished due to the fact that sudden power failure exists in the process of executing PAGE REFRESH last time, at this time, execution PAGE REFRESH can be started from page3 which is stored in the third preset storage area, PAGE REFRESH is avoided from beginning to execute from the first page, therefore PAGE REFRESH efficiency is improved, unnecessary PAGE REFRESH operation is avoided, and reliability of Nor Flash is improved. If no valid backup data exists in the second preset storage area, it indicates that the previous execution PAGE REFRESH is not interrupted, and no initial storage unit for executing refresh is determined to be executed PAGE REFRESH according to the identification information, so that PAGE REFRESH needs to be executed on the initial storage unit from the beginning, i.e. the first page.

In the specific embodiment, whether the previous PAGE REFRESH is interrupted by abnormal power failure or the like can be quickly determined through the backup identifier, if the interrupted condition exists, the execution of PAGE REFRESH is continued in the place of the last interruption, and if the interrupted condition does not exist, PAGE REFRESH of each page is normally carried out from the beginning, so that the PAGE REFRESH efficiency and the device reliability are improved.

In a specific implementation manner of the present disclosure, after determining that the page refreshing operation on the second memory cell is completed, step S3 is further performed before updating the identification information in the first preset storage area to the identification information corresponding to the initial memory cell to be refreshed in sequence, where the erasing method further includes:

And erasing the stored data in the second preset storage area and the third preset storage area.

Specifically, after determining that PAGE REFRESH on the second storage unit is completed, the stored data in the second preset storage area and the third preset storage area needs to be subjected to erase to prepare for PAGE REFRESH of the initial storage unit to be refreshed next.

In this embodiment, after the completion of PAGE REFRESH on the second storage unit is determined, before updating the identification information in the first preset storage area to the identification information corresponding to the initial storage unit to be refreshed in the next sequence, the stored data in the second preset storage area and the third preset storage area are prepared for the subsequent PAGE REFRESH by the erase, and smooth execution of PAGE REFRESH is ensured, so that the efficiency of PAGE REFRESH is improved.

In a specific embodiment of the disclosure, as shown in fig. 4, step S32 includes:

S321, reading corresponding initial storage data in a current target page by adopting a preset acquisition mode to obtain first storage data, and writing the first storage data into a page buffer area;

S322, reading corresponding initial storage data in the current target page by adopting a preset edge bias condition to obtain second storage data;

s323, judging whether the first storage data is consistent with the second storage data; if so, the process proceeds to step S324, and if not, the process proceeds to step S325;

S324, determining that the current target page does not need to be subjected to page refreshing operation;

S325, determining that the current target page needs to be subjected to page refreshing operation.

In step S321, a preset acquiring manner (for example, read bias condition (reading bias condition, reading with normal voltage)) is adopted to read the corresponding initial storage data in the current target page, and write the initial storage data into a page buffer (page buffer), wherein the page buffer is a circuit originally carried by the norflash. As shown in fig. 5, the sample distribution diagram of testing three failed chips 1, 3 and 4 is obtained by reading the corresponding initial stored data in the current target page using read bias condition, and the corresponding 1 distribution (left part) and the corresponding 0 distribution (right part) can be obtained, where it can be obtained that part 0 is disturbed (circle part), i.e. is about to be disturbed to become 1.

In step S322, the preset edge bias condition is also referred to as a preset edge bias verification condition (margin bias verify condition), and the corresponding initial stored data in the current target page is read by using the preset edge bias condition to reserve a sufficient threshold margin.

In step S323, the data read in step S322 by using the preset edge bias condition is compared with the data in the page buffer, if the two data are consistent, it is indicated that the current target page does not have interfered bits, and step S324 is entered to determine that the current target page does not need PAGE REFRESH; if the two data are inconsistent, it indicates that the current target page has interfered bits, and the process goes to step S325 to determine that the current target page needs to be performed PAGE REFRESH.

According to the embodiment, the corresponding initial storage data in the current target page is read by adopting a preset acquisition mode and a preset edge bias condition to be compared so as to determine whether the current target page has interfered bits, if so, PAGE REFRESH is carried out on the current target page, the interfered bits are timely adjusted to be correct bits, errors of storage data caused by the interfered bits are avoided, and the reliability of the Nor Flash storage data is ensured.

In a specific embodiment of the present disclosure, after step S314, before step S32, the erasing method further includes:

and reading the first storage data in the second preset storage area, and writing the first storage data into the current target page.

Specifically, in the process of performing the page refresh operation, there may be a sudden power failure to cause data loss of the page, for example, after the stored data of the page is written into the page buffer and the second preset storage area in the process of performing PAGE REFRESH, an erase is executed on the page, but the situation that the sudden power failure occurs when the data of the page buffer is written back into the page is not yet reached, because the data is lost when the page buffer is powered down, thereby causing data loss. According to the scheme provided by the embodiment, the data is backed up to the second preset storage area which is not lost when power is lost in advance before refresh, when the power is on again, the current target page can be determined through the page address in the third preset storage area, the backed-up first storage data is written into the current target page through the second preset storage area, and whether the target page needs to be subjected to PAGE REFRESH or not is judged according to the written data, so that the data is not lost.

Before judging whether the current target page needs PAGE REFRESH, the embodiment writes the data backed up before the previous power failure into the current target page, so that the condition of loss of storage data caused by abnormal power failure is avoided, and the reliability of the Nor Flash storage data is further ensured.

In this embodiment, by adding a page refreshing operation flow in the erasing process and storing the identification information corresponding to the initial storage unit to be refreshed by using the first preset storage area which is not lost when power is turned off, it is ensured that all unselected pages have a chance to be refreshed under the condition that the erasing time specification is not exceeded, and the reliability and the service life of the nonvolatile memory can be effectively improved. And the second preset storage area and the third storage area which are not lost when power failure is utilized to realize power failure protection when the page is refreshed, so that the condition that data stored by the unselected page is damaged due to power failure in the erasing operation process is effectively avoided, and the reliability and the service life of the nonvolatile memory are further improved.

Example 2

In a specific embodiment of the present disclosure, an erasing system of a Nor Flash is provided, where the Nor Flash includes a plurality of initial storage units and a first preset storage area that is not lost when power is turned off, each initial storage unit includes a plurality of pages, each initial storage unit has corresponding identification information, and the first preset storage area is used for storing the identification information corresponding to the initial storage unit to be refreshed;

as shown in fig. 6, the erase system includes an erase module 100, a determination module 200, and a page refresh module 300;

The erasing module 100 is configured to determine a first storage unit to be erased in a plurality of initial storage units based on the erasing instruction after each time the erasing instruction is received, and control to perform an erasing operation on the first storage unit;

the determining module 200 is configured to determine, based on the erase instruction and the identification information in the first preset storage area, that an initial storage unit to be refreshed corresponding to the identification information is a second storage unit;

The page refreshing module 300 is configured to perform a page refreshing operation on the second memory unit, and update the identification information in the first preset storage area to the identification information corresponding to the next initial memory unit to be refreshed sequentially after the page refreshing operation on the second memory unit is completed.

Note that, for the erasing system of the Nor Flash in the present embodiment, it is based on the corresponding method embodiment 1, so the relevant points are only needed to see the part of the description of the method embodiment 1.

According to the method and the device for refreshing the non-volatile memory, the page refreshing operation flow is added in the erasing process, the identification information corresponding to the initial memory unit to be refreshed is stored by utilizing the first preset memory area which is not lost when power is lost, all unselected pages can be guaranteed to have the opportunity to be refreshed under the condition that the erasing time standard is not exceeded, and the reliability and the service life of the non-volatile memory can be effectively improved. And the second preset storage area and the third storage area which are not lost when power failure is utilized to realize power failure protection when the pages are refreshed, so that the condition that data stored by unselected pages are damaged due to power failure in the erasing operation process is effectively avoided, the reliability and the service life of the nonvolatile memory are further improved, and the overall product performance of the Nor Flash is improved.

Example 3

In a specific embodiment of the present disclosure, a Nor Flash is provided, which is implemented using the Nor Flash erase method of embodiment 1.

According to the method and the device for refreshing the non-volatile memory, the page refreshing operation flow is added in the erasing process, the identification information corresponding to the initial memory unit to be refreshed is stored by utilizing the first preset memory area which is not lost when power is lost, all unselected pages can be guaranteed to have the opportunity to be refreshed under the condition that the erasing time standard is not exceeded, and the reliability and the service life of the non-volatile memory can be effectively improved. And the second preset storage area and the third storage area which are not lost when power failure is utilized to realize power failure protection when the pages are refreshed, so that the condition that data stored by unselected pages are damaged due to power failure in the erasing operation process is effectively avoided, the reliability and the service life of the nonvolatile memory are further improved, and the overall product performance of the Nor Flash is improved.

While specific embodiments of the present disclosure have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and the scope of the disclosure is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the principles and spirit of the disclosure, but such changes and modifications fall within the scope of the disclosure.

Claims (10)

1. The erasing method of the Nor Flash is characterized in that the Nor Flash comprises a plurality of initial storage units and a first preset storage area which is not lost when power is lost, each initial storage unit comprises a plurality of pages, each initial storage unit is provided with corresponding identification information, and the first preset storage area is used for storing the identification information corresponding to the initial storage unit to be refreshed;

The erasing method comprises the following steps:

after each time an erasure instruction is received, determining a first storage unit to be erased in a plurality of initial storage units based on the erasure instruction, and controlling the first storage unit to be erased;

Determining the initial storage unit to be refreshed corresponding to the identification information as a second storage unit based on the erasing instruction and the identification information in the first preset storage area;

and executing page refreshing operation on the second memory unit, and after the page refreshing operation on the second memory unit is completed, updating the identification information in the first preset memory area to the identification information corresponding to the initial memory unit to be refreshed next in sequence.

2. The erase method of claim 1, wherein the Nor Flash further comprises a second preset storage area and a third preset storage area, the second preset storage area and the third preset storage area not lost when power is lost, the third preset storage area being used for storing a page address and a backup identifier;

The step of performing a page refresh operation on the second memory cell includes:

acquiring a target page to be refreshed in the second memory unit;

Judging whether the current target page needs to carry out page refreshing operation or not;

If the current target page does not need to be subjected to page refreshing operation, judging whether the current target page is the last target page to be refreshed in the second storage unit, if not, acquiring the next target page to be refreshed in the second storage unit, and returning to the step of executing the step of judging whether the current target page needs to be subjected to page refreshing operation;

If the current target page needs to be subjected to page refreshing operation, writing corresponding initial storage data in the current target page into the second preset storage area, writing a page address corresponding to the current target page and a backup identifier into the third preset storage area, executing page refreshing operation on the current target page, judging whether the current target page is the last target page to be refreshed in the second storage unit after finishing the page refreshing operation on the current target page, if not, acquiring the next target page to be refreshed in the second storage unit, and returning to the step of executing the step of judging whether the current target page needs to be subjected to page refreshing operation.

3. The erasing method as recited in claim 2, wherein the step of acquiring the target page to be refreshed in the second memory cell includes:

Reading the backup identifier in the third preset storage area;

Judging whether backup data exists in the second preset storage area or not based on the backup identifier;

if not, taking the first target page in the second storage unit as the current target page;

If yes, the page address in the third preset storage area is read as the current target page.

4. The erasing method according to claim 2, wherein after determining that the page refresh operation for the second memory cell is completed, before the updating of the identification information in the first preset memory area to the identification information corresponding to the initial memory cell to be refreshed next in turn, the erasing method further comprises:

and erasing the stored data in the second preset storage area and the third preset storage area.

5. The erasing method as set forth in claim 2, wherein the step of determining whether the current target page requires a page refresh operation comprises:

Reading corresponding initial storage data in the current target page by adopting a preset acquisition mode to obtain first storage data, and writing the first storage data into a page buffer area;

reading the corresponding initial storage data in the current target page by adopting a preset edge bias condition to obtain second storage data;

Judging whether the first storage data is consistent with the second storage data or not;

if the target pages are consistent, determining that the current target pages do not need to be subjected to page refreshing operation;

if the target pages are inconsistent, determining that the current target pages need to be subjected to page refreshing operation.

6. The erasing method as set forth in claim 3, wherein after said step of reading said page address in said third preset storage area as the current target page, said erasing method further includes, before said step of judging whether or not the current target page requires a page refresh operation:

And reading the first storage data in the second preset storage area, and writing the current target page.

7. The erase method of claim 1, wherein the initial storage unit includes a sector, a half block, or a full block;

and/or the number of the groups of groups,

The identification information is the number or address of the initial storage unit.

8. The erase method according to any one of claims 1 to 7, wherein the nors Flash is ETOX Flash or SONOS Flash.

9. The erasing system of the Nor Flash is characterized by comprising a plurality of initial storage units and a first preset storage area, wherein the first preset storage area is not lost when power is lost, each initial storage unit comprises a plurality of pages, each initial storage unit is provided with corresponding identification information, and the first preset storage area is used for storing the identification information corresponding to the initial storage unit to be refreshed;

The erasing system comprises an erasing module, a determining module and a page refreshing module;

The erasing module is used for determining a first storage unit to be erased in a plurality of initial storage units based on the erasing instruction after each time of receiving the erasing instruction, and controlling the first storage unit to be erased;

the determining module is configured to determine, based on the erase instruction and the identification information in the first preset storage area, that the initial storage unit to be refreshed corresponding to the identification information is a second storage unit;

the page refreshing module is used for executing page refreshing operation on the second storage unit, and updating the identification information in the first preset storage area to the identification information corresponding to the initial storage unit to be refreshed next in sequence after the page refreshing operation on the second storage unit is completed.

10. Nor Flash, characterized in that it is realized using the erasing method of Nor Flash according to any of claims 1 to 8.