Data rereading method, electronic equipment and storage medium

Abstract

The invention provides a data rereading method, electronic equipment and a storage medium. The method comprises the following steps: recording previous information of repeated rereading; estimating state wave information of each reading level based on the multiple pieces of rereading reference voltage and the multiple pieces of column height information which are reread for multiple times at each reading level; and based on the estimated state wave information, determining the next re-reading reference voltage of each reading level, and performing the next re-reading. According to the method, the number information of the difference data read during two adjacent times of re-reading is obtained according to the previous re-reading information, and the reading offset direction capable of reducing the error rate of the re-reading data can be determined according to the number information, so that the next re-reading reference voltage can be determined according to the reading offset direction and the re-reading reference voltage in the previous re-reading process; according to the method, the error rate of the next rereading can be reduced, namely, the success rate of data reading is improved, so that the time consumption of data reading is reduced.

Description

Technical Field

[0001] The disclosed embodiments of the present application relate to the field of radio frequency communication technology, and more particularly, to a data rereading method, an electronic device, and a storage medium. Background Art

[0002] Currently, mainstream NAND Flash generally uses 3D TLC / QLC. Relying on the high storage density of TLC / QLC, it can reduce costs compared to SLC / MLC. Therefore, most products will preferentially choose TLC / QLC NAND Flash. However, due to its high storage density, the influence of factors such as usage time and usage environment on it is more obvious, and the data reliability in NAND Flash faces more threats. To ensure data reliability, when data errors occur, a rereading list can be used for repeated read attempts, which is an important means in the data error correction and recovery process.

[0003] However, the current rereading process causes a large amount of latency, and each rereading is performed independently, without making full use of the relevant information generated during the previous rereading process.

[0004] Therefore, how to reduce the data reading time consumption has become an urgent problem to be solved. Summary of the Invention

[0005] According to an embodiment of the present application, the present invention proposes a data rereading method to reduce the data reading time consumption.

[0006] According to one aspect of the present application, an exemplary data rereading method applied to a memory is disclosed, including: recording information of multiple previous rereadings, where the information of the multiple previous rereadings includes multiple rereading reference voltages and multiple column height information for multiple rereadings of each read level of the same read page, and the column height information represents the number of difference data between the read data of two adjacent rereadings; estimating the state wave information of each read level based on the multiple rereading reference voltages and the multiple column height information for multiple rereadings of each read level; determining the next rereading reference voltage of each read level based on the estimated state wave information, and performing the next rereading.

[0007] According to a second aspect of the present application, an electronic device is provided, including a memory and a processor coupled to each other, and the processor is configured to execute program instructions stored in the memory to implement the data rereading method of the first aspect above.

[0008] According to a third aspect of the present application, a non-volatile computer-readable storage medium is provided, on which program instructions are stored, and when the program instructions are executed by a processor, the data rereading method of the first aspect above is implemented.

[0009] The above scheme obtains the number information of the difference data read in two adjacent rereads based on the information of the previous reread. The number information can be used to determine the reading offset direction that can reduce the error rate of the reread data. Therefore, the next reread reference voltage can be determined based on the reading offset direction and the reread reference voltage of the previous reread process. The next reread can reduce the error rate of the next reread, that is, improve the success rate of data reading, and then reduce the time consumption of data reading. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present application will be further described below in conjunction with the accompanying drawings and implementation methods, in which:

[0011] Figure 1 It is a schematic diagram of rereading after the threshold voltage shifts;

[0012] Figure 2 It is a flow chart of an embodiment of the data re-reading method of the present application;

[0013] Figure 3 It is a schematic diagram of reading using different reading gears within a reading page;

[0014] Figure 4 It is a schematic diagram showing that the intervals between different re-read reference voltages of the same read level at different gears are different;

[0015] Figure 5 It is a schematic diagram of the state wave fitting curve corresponding to a certain reading level;

[0016] Figure 6 It is a schematic diagram of the peaks that occurred during the curve fitting process;

[0017] Figure 7 is a flowchart of an embodiment of sub-step 1 of step S240;

[0018] Figure 8 It is a schematic diagram of the framework of an embodiment of the electronic device of the present application;

[0019] Figure 9 A schematic diagram of a framework of an embodiment of a non-volatile computer-readable storage medium of the present application. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the present application, the technical solution of the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods; it is obvious that the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0021] The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally also include steps or units not listed, or may optionally also include other steps or units inherent to these processes, methods, products or devices.

[0022] NAND flash memory is currently the storage medium of a mainstream large-capacity storage device. NAND flash memory consists of basic storage units composed of a type of MOS transistor similar to NMOS. The structure used to store charge is called a floating gate, which is composed of a semiconductor that enables unidirectional current conduction between the source and the drain. The outside of the floating gate is wrapped by a layer of silicon oxide film insulator, the purpose of which is to restrict the free diffusion of electrons. The select / control gate is located above it and is used to control the conduction current between the source and the drain. As a non-volatile memory, the charge in the floating gate of NAND flash memory can continue to be retained after power-off.

[0023] NAND flash memory realizes data storage by restricting the diffusion of electrons through an insulating oxide layer. However, during the life cycle of the flash memory, as the number of erase and write cycles experienced by the flash memory cells increases, the insulating oxide layer gradually degrades, resulting in easy charge loss and shortened data retention time. At the same time, in order to provide acceptable large-capacity storage devices, flash memory manufacturers have subsequently proposed MLC (Multi-Level Cell), TLC (Triple-Level Cell) and even QLC (Quad-Level Cell) on the basis of SLC (Single-Level Cell). This means that multiple bit information will be stored in a single storage unit and corresponds to multiple voltage states at the same time. The more bit information stored in each cell, the more complex the required control voltage, and at the same time, the smaller the threshold voltage range corresponding to each state.

[0024] In the data retention scenario, the charge stored in the NAND flash memory storage layer gradually leaks and diffuses before erasure. The longer the data retention time in the flash memory, the higher the reliability risk, the more serious the error situation, and the threshold voltage of the storage cell will shift towards the low voltage direction; in the read interference scenario, as the number of read operations gradually accumulates, the charge miswriting effect on the storage layer will gradually amplify, causing the threshold voltage distribution of the NAND flash memory to shift towards the high voltage direction.

[0025] Due to the threshold voltage shift, adjacent voltage state waves will overlap. When reading data using the original read reference voltage, bit misjudgment is likely to occur, that is, a read error occurs. Therefore, in order to read the correct data, read retry is required. Please refer to Figure 1 , Figure 1 is a schematic diagram of read retry after the threshold voltage shift; as Figure 1 shown, due to the threshold voltage shift, overlapping regions appear in the middle between the left and right adjacent state waves. The optimal read reference voltage is the voltage corresponding to the vicinity of the troughs of the two state waves; the dashed lines represent the read reference voltages (Vref) used for each read retry. Five read retries are performed respectively. The read reference voltage of the third (3rd) read retry is closest to the trough position, that is, the read reference voltage of the third read retry is in the optimal position. Therefore, the read reference voltage used for the third read retry is better than other read reference voltages. When performing read retry, a read retry list is usually used, and the read reference voltage is selected from the read retry list for read retry. However, the more read retry times, the longer the data read latency often means. The disclosed embodiments of the present application can minimize the number of read retries to reduce the data read latency.

[0026] According to one aspect of the present application, an exemplary data read retry method applied to a memory is disclosed. Please refer to Figure 2 , Figure 2 is a flowchart of an embodiment of the data read retry method of the present application; specifically, the data read retry method includes:

[0027] Step S220: Record the information of multiple previous read retries. Among them, the information of multiple previous read retries includes multiple read reference voltages and multiple column height information for multiple read retries of each read level of the same read page. The column height information represents the number information of the difference data between the read data of two adjacent read retries;

[0028] Step S240: Estimate the state wave information of each read level based on the multiple read reference voltages and multiple column height information for multiple read retries of each read level;

[0029] Step S260: Determine the next read reference voltage of each read level based on the estimated state wave information, and perform the next read retry.

[0030] In the above solution, according to the information of the previous read retry, the number information of the difference data read during two adjacent read retries is obtained. From this number information, the read offset direction that can reduce the read data error rate can be determined. Therefore, according to the read offset direction and the read reference voltage during the previous read retry process, the next read reference voltage can be determined, and the next read retry is performed, which can reduce the error rate of the next read retry, that is, improve the success rate of data reading, and further reduce the data read time consumption.

[0031] It should be noted that the "multiple times" mentioned in the disclosed embodiments of this application refers to two or more times, such as 2 times, 3 times, etc., and this application does not make any limitations in this regard.

[0032] In this application, taking TLC as an example, for TLC, one basic storage unit can respectively confine 8 different orders of magnitude of electrons in its charge trap to respectively store 8 different data, that is, 000 to 111; at the same time, corresponding to the basic storage unit in which 8 different orders of magnitude of electrons are respectively stored in the charge trap, it respectively has different threshold voltages, and 7 different read reference voltages are respectively required to read the data stored therein. The reading of data is usually carried out in units of reading a page. In TLC, a reading page includes 3 parts, namely: a low reading page, a middle reading page, and a high reading page; while in MLC, a reading page can include a low reading page and a high reading page. In some embodiments of this application, the low reading page and the high reading page respectively include two reading levels, and the middle reading page includes three reading levels. That is to say, for the low reading page or the high reading page, 2 different read reference voltages are used to read the data therein; for the middle reading page, 3 different read reference voltages are used to read the data therein. Of course, for the three parts of the reading page, other reading methods can also be adopted. For example, the low reading page includes 1 reading level, the middle reading page includes 2 reading levels, and the high reading page includes 4 reading levels, etc., and this application does not make any limitations in this regard. In this application, one reading level corresponds to one read reference voltage. In addition, the data rereading method of this application can not only be used for rereading TLC data, but also for rereading MLC, QLC, etc.

[0033] In some embodiments, the estimated state wave information includes an estimated adjustment offset direction pointing to the trough of the state wave; wherein, the memory stores a retry table, the retry table records multiple retry gears, each retry gear is respectively used to record a corresponding read reference voltage at each reading level of the same reading page, and the memory performs a rereading operation with the corresponding read reference voltage at each reading level corresponding to the selected retry gear.

[0034] For example, for TLC, a read retry level may have 7 different read retry reference voltages corresponding to the same read page, respectively corresponding to 7 different read levels. When the threshold voltage shifts, although the shifts of the state waves corresponding to different threshold voltages are different, an effective read retry level cannot ensure that each read retry reference voltage is in the optimal position (i.e., near the trough of the shifted state wave, specifically refer to Figure 1 ), however, for a relatively good read retry level, the read retry reference voltages corresponding to the read levels under the same read page (such as low read page, medium read page, high read page) will be closer to the trough position of the state wave compared to the read retry reference voltages of other levels. Please refer to Figure 3 , Figure 3 is a schematic diagram of reading using different read retry levels within a read page. As Figure 3 shown, taking the read of the low read page as an example, the state waves corresponding to two different read levels of the low read page are on the left and right sides respectively, and the dashed lines respectively represent the read retry reference voltages (Vref) corresponding to the read retry levels used for the first (1st) retry, second (2nd) retry, and third (3rd) retry; when reading using different read retry levels, the number information of the difference data between the read data obtained between different read retry levels is represented by the column height between different read retry reference voltages (i.e., Figure 3 the gray filled part in), the higher the column height, the more the number of difference data; it can be seen that the column height between the read retry reference voltages corresponding to the two read levels of the read retry level used for the third retry and other read retry reference voltages is the lowest, and thus it can be determined that the read retry level used for the third retry is better than other levels. Therefore, the direction in which the column height decreases, that is, the direction in which the read retry reference voltage becomes better, adjusting the read retry reference voltage in the direction in which the column height decreases (i.e., the direction pointing to the trough of the state wave) can improve the success rate of the next retry, thereby reducing the number of data retries and reducing the latency of data reading.

[0035] In some embodiments of the present application, the read retry reference voltages corresponding to different read levels within the same read page can be adjusted with the same change trend or with different change trends; for example, for the 2 read levels of the low read page, their read retry reference voltages can be increased and decreased respectively, or can be increased or decreased simultaneously, and the present application does not make any limitations in this regard.

[0036] In some embodiments of the present application, the information of multiple prior readbacks may include: storing the first data read from the read page during the current readback in the first buffer unit; storing the second data read from the read page during the previous readback in the second buffer unit; storing the difference data between the first data and the second data in the third buffer unit to count the number of difference data between the first data and the second data. In other words, the read data obtained from two readbacks can be stored in different buffer units respectively, and the difference between the two can be calculated to obtain the difference data between the first data and the second data.

[0037] For example, during the first readback, the second data obtained from the first readback can be stored in the first buffer unit. Since there is no read data from a prior readback at this time, no calculation is required. At the start of the second readback, or after the first readback ends, the second data stored in the first buffer unit is transferred to the second buffer unit, and the first data obtained from the second readback is stored in the first buffer unit. After the second readback ends, by calculating and comparing the number of difference data in the two buffer units, specifically, the data in the first buffer unit and the second buffer unit can be subjected to an exclusive OR operation, and the data obtained after the exclusive OR operation is stored in the third buffer unit. The number of logical values "1" in the third buffer unit is counted to obtain the number of difference data between the first data and the second data. Then, the first data obtained from the second readback is transferred to the first buffer unit. During the third readback, the read data obtained from the third readback is stored in the second buffer unit. By repeating the above steps, the number of difference data between two readbacks, that is, the column height information, can be obtained.

[0038] In some embodiments of the present application, based on multiple read reference voltages and multiple column height information obtained by performing multiple readbacks for each read level, estimating the state wave information of each read level may include:

[0039] Step S242: In response to the memory performing a level indication read between read levels, compare the multiple column height information obtained by performing multiple readbacks for each read level, and estimate the adjustment offset direction for the next readback, where the adjustment offset direction is towards the column height decreasing direction.

[0040] Since in TLC, a basic memory cell can store electrons of 8 different orders of magnitude in its charge trap, accordingly, 7 different rereference voltages are required to read the data stored therein. These 7 different rereference voltages correspond to 7 different read levels. It can be understood that the rereference voltages corresponding to different read levels may have different voltage levels. For example, for a certain read level, the corresponding rereference voltage is around 0.5V, while for another read level, the corresponding rereference voltage may be around 5mV. Therefore, under the condition that the rereference voltages corresponding to different read levels may have different voltage levels, the intervals between the different rereference voltages of different read gears are naturally different. If the different read levels are not distinguished, when the intervals between the rereference voltages corresponding to the same read level of different read gears are different, they cannot be converted to equal intervals for statistics. Therefore, in the case where the memory does not perform level indication reading between read levels, overall rough statistics are performed.

[0041] In some embodiments of the present application, based on multiple rereference voltages and multiple column height information for multiple rereads for each read level, estimating the state wave information of each read level may include:

[0042] Step S242: In response to the memory performing level indication reading between read levels, determine the rereference voltages corresponding to the reread gears for each read level for multiple rereads, and determine the interval between two adjacent rereference voltages of two consecutive rereads as the adjustment interval;

[0043] Step S244: Compare two adjacent adjustment intervals, and estimate the estimated column height information corresponding to the adjustment interval with a smaller value based on the column height information corresponding to the adjustment interval with a larger value and the two adjustment intervals;

[0044] Step S246: Compare the recorded column height information corresponding to the adjustment interval with a smaller value and the estimated column height information, and estimate the adjustment offset direction for the next reread.

[0045] Please refer to the foregoing embodiments. In the case of not performing level indication reading, in the case where the intervals between the different rereference voltages of the same read level of different gears are different, equal interval estimation cannot be performed; in the case of performing level indication reading, that is, after distinguishing different read levels, in the case where the intervals between the rereference voltages corresponding to the same read level between different gears are not equal. For example, for a certain read level, the rereference voltages of different gears are 5mV, 5.5mV, and 7mV respectively (the voltage data is only for illustrative purposes and does not constitute a limitation to the present application), the intervals between the rereference voltages at different gears are not equal, and equal interval estimation can be performed, that is, different voltage intervals can be converted to the same voltage interval.

[0046] A specific example of equal interval estimation is introduced below. Please refer to Figure 4 , Figure 4 which is a schematic diagram showing different intervals between different rereference voltages of the same read level at different gears; in Figure 4 , only one state wave corresponding to the read level is shown. Determine the rereference voltages corresponding to the reread gears for multiple rereads. For example, determine that the rereference voltages corresponding to the three reread gears are Vref1, Vref2, and Vref3 respectively; compare the intervals between adjacent rereference voltages as the adjustment intervals. For example, the adjustment interval between Vref1 and Vref2 is y1, and the adjustment interval between Vref2 and Vref3 is y2; since the two adjustment intervals are not equal and y2 is greater than y1, it is necessary to convert them to equal intervals. Obtain the column height information q corresponding to y2 2 , estimate the estimated column height information q corresponding to y1 after adjusting y1 to be equal to y2. The estimated column height information q can be calculated by the following formula: q = a t , where the base a can be configured according to the actual situation. By comparing the estimated column height information q and the recorded column height information q corresponding to y1 1 , predict the adjustment offset direction for the next reread. For example, when q is greater than q 1 , the next reread is adjusted in the direction of q 1 . In other embodiments, it is also possible to estimate the estimated column height information corresponding to the larger adjustment interval based on the column height information corresponding to the smaller adjustment interval and the two adjustment intervals. The present application does not limit this.

[0047] In some embodiments, based on the predicted state wave information, determine the next rereference voltage for each read level and perform the next reread, including:

[0048] Step S262: Based on the predicted adjustment offset direction, select the next reread reference gear from the multiple reread gears of each read level.

[0049] For example, please continue to refer to Figure 4 , assuming that the predicted adjustment offset direction is from Vref1 to Vref3, then the reread gear corresponding to Vref3 can be used as the next reread reference gear.

[0050] Step S264: Select the reread selection gear closest to the reference gear among the reread selection gears as the next reread gear, where the reread selection gear is other reread gears that conform to the adjustment offset direction relative to the reference gear.

[0051] For example, if the offset direction is adjusted from Vref1 to Vref3, i.e., the direction in which the voltage increases, the reread reference voltage of a reread page in a reread selection gear should be greater than the reread reference voltage of the corresponding reread page in the reference gear.

[0052] In some embodiments, step S264 may include: sequentially traversing the distances of all reread selection gears relative to the reference gear, and selecting the reread selection gear with the closest distance as the next reread gear, where the distance of any reread selection gear relative to the reference gear is the square root of the sum of the squares of the differences between the corresponding reread reference voltages of the corresponding reread selection gear at each read level and the reread reference voltage of the reference gear at the corresponding read level.

[0053] Specifically, taking the medium reread page with 3 read levels as an example, the reread reference voltages corresponding to the 3 read levels in the reference gear are respectively [x 1 , x 2 , x 3 , and the reread reference voltages corresponding to the 3 read levels in the reread selection gear are respectively [y i1 , y i2 , y i3 , where i is a positive integer used to distinguish different reread selection gears; then the distance D of the reread selection gear relative to the reference gear can be calculated by the following formula:

[0054]

[0055] Step S266: Perform the next reread based on the corresponding reread reference voltages at each read level of the next reread gear.

[0056] In some embodiments of the present application, the estimated state wave information may include an estimated state wave fitting curve. In this embodiment, in order to obtain the estimated state wave fitting curve, level indication reads need to be performed to distinguish different read levels, and then curve fitting is performed on the distribution of the column height information of the state waves corresponding to different read levels. Please refer to Figure 5 , Figure 5 which is a schematic diagram of the state wave fitting curve corresponding to a certain read level; after distinguishing different read levels, the state waves of a certain read level are read using five read gears respectively, i.e., the 5 reread reference voltages are respectively [v 1 , v 2 , v 3 , v 4 , v 5 , the column height information between the five reads is statistically analyzed, and the obtained column heights are respectively [d 1 , d 2 , d 3 , d 4; After obtaining the re-reading reference voltage and the corresponding column height information, curve fitting can be performed. For example, if quadratic function curve fitting is used, then , , , can be respectively substituted into the quadratic function expression y = ax 2 + bx + c to solve for a, b, and c. After obtaining the quadratic fitting curve, the vertex formula or derivative can be used to solve for the minimum point, and thus the re-reading reference voltage corresponding to the minimum column height can be obtained. The re-reading reference voltage corresponding to the minimum column height can be used as the re-reading reference voltage for the next re-reading to perform the next re-reading. It should be noted that the next re-reading reference voltage obtained by curve fitting is not necessarily the re-reading reference voltage in the re-reading list, that is, the next re-reading reference voltage can be a voltage other than the re-reading reference voltage recorded in the re-reading list. 2 + bx + c to solve for a, b, c. After obtaining the quadratic fitting curve, the vertex formula or derivative can be used to solve for the minimum point, and the re-reading reference voltage corresponding to the minimum column height can be obtained, and the re-reading reference voltage corresponding to the minimum column height can be used as the re-reading reference voltage for the next re-reading to perform the next re-reading.

[0057] It should be noted that when performing curve fitting, it is not limited to quadratic function curve fitting, and other various curve functions can also be used for fitting. The quadratic function curve fitting here is only an example. In addition, for the case where the intervals between the re-reading reference voltages of different reading gears are different, after equal interval estimation with reference to the foregoing embodiments, curve fitting can be performed, which will not be elaborated here.

[0058] When performing curve fitting using the column height information and the re-reading reference voltage as described above, an overshoot problem may occur. Please refer to Figure 6 , Figure 6 , which is a schematic diagram of overshoot occurring during the curve fitting process; in the figure, v1 to v7 are the re-reading reference voltages used for multiple readings respectively, and d1 to d6 are the column height information corresponding to multiple readings respectively. When performing quadratic curve fitting using the column height information and the re-reading reference voltage, a curve with a downward opening will be fitted at d1 to d2. At this time, the extreme point obtained by using the vertex formula or derivative is the highest point, rather than the lowest point located at the bottom of the state wave valley that is desired. Therefore, it is necessary to screen the column height information and perform curve fitting using the screened column height information.

[0059] In some embodiments, after obtaining the estimated state wave fitting curve, when the estimated state wave information includes the estimated state wave fitting curve, please refer to Figure 7 , Figure 7 , which is a schematic flowchart of an embodiment of sub-step 1 of step S240; the above-mentioned step S240 may include: Figure 6 , Figure 6 is a schematic diagram of overshoot occurring during the curve fitting process; in the figure, v1 to v7 are the re-reading reference voltages used for multiple readings respectively, and d1 to d6 are the column height information corresponding to multiple readings respectively. When performing quadratic curve fitting using the column height information and the re-reading reference voltage, a curve with a downward opening will be fitted at d1 to d2. At this time, the extreme point obtained by using the vertex formula or derivative is the highest point, rather than the lowest point located at the bottom of the state wave valley that is desired. Therefore, it is necessary to screen the column height information and perform curve fitting using the screened column height information.

[0060] So, after obtaining the estimated state wave fitting curve, in some embodiments, when the estimated state wave information includes the estimated state wave fitting curve, please refer to Figure 7 , Figure 7 , which is a schematic flowchart of an embodiment of sub-step 1 of step S240; the above-mentioned step S240 may include: Figure 7 , Figure 7 is a schematic flowchart of an embodiment of sub-step 1 of step S240; the above-mentioned step S240 may include:

[0061] Step S241: Based on the multiple column height information of multiple re-reading records for each reading level, determine the scene type.

[0062] Step S243: In response to the scene type conforming to the first type of scene, perform quadratic function curve fitting based on multiple rereading reference voltages and multiple column height information obtained by performing multiple rereadings for each reading level.

[0063] In some embodiments, the determination conditions for the scene type include: Condition a, the minimum column height information among the information of multiple previous rereadings is in a non-edge part; Condition b, the maximum column height information among the information of multiple previous rereadings is in a non-edge part.

[0064] The first type of scene includes a first sub-scene and a second sub-scene. Among them, if Condition a is satisfied and Condition b is not satisfied, it is determined as the first sub-scene, indicating that the trough of the state wave is in the middle part of the information of multiple previous rereadings; if Condition a is not satisfied and Condition b is not satisfied, it is determined as the second sub-scene, indicating that both the peak and trough of the state wave are not in the middle part of the information of multiple previous rereadings. Therefore, in the first type of scene, when performing curve fitting using the collected column height information, a curve opening downward will not be obtained. For example Figure 5 as shown, the minimum column height information is d 3 , which is in the non-edge part, and Condition a is satisfied; the maximum column height information is d 1 , which is in the edge part, and Condition b is not satisfied. Therefore, it belongs to the first sub-scene in the first type of scene. That is to say, in the first type of scene, the maximum column height information collected needs to be in the edge part of the fitting region (such as Figure 5 the d in 1 or d 4 the area where it is located), and the fitting region is Figure 5 the region between v 1 ~v 5 in

[0065] In the first type of scene, the collected column height information and multiple rereading reference voltages can be directly used for quadratic function curve fitting without screening, because no overshoot will occur at this time.

[0066] Step S245: In response to the scene type conforming to the second type of scene, screen the multiple rereading reference voltages and multiple column height information for each reading level, and perform quadratic function curve fitting based on the selected part of the multiple rereading reference voltages and multiple column height information.

[0066] The second type of scene includes a third sub-scene and a fourth sub-scene. Among them, if Condition a is not satisfied and Condition b is satisfied, it is determined as the third sub-scene, indicating that the peak of the state wave is in the middle part of the information of multiple previous rereadings; if Condition a is satisfied and Condition b is satisfied, it is determined as the fourth sub-scene, indicating that both the peak and trough of the state wave are in the middle part of the information of multiple previous rereadings. That is to say, in the second type of scene, the maximum column height information collected needs to be in the non-edge part of the fitting region. As Figure 6As shown, the minimum column height information is d5, which is in the non-edge part; the maximum column height information is d2, which is also in the non-edge part. Therefore, both condition a and condition b are satisfied, belonging to the fourth sub-scenario. In the second type of scenario, due to the occurrence of over-peaks, it is necessary to screen multiple re-read reference voltages and multiple column height information collected to prevent a downward-opening quadratic function curve from appearing after fitting, resulting in the inability to obtain the next re-read reference voltage.

[0067] In some embodiments, in response to the scenario type conforming to the second type of scenario, screening is performed on multiple re-read reference voltages and multiple column height information for each read level, and quadratic function curve fitting is performed based on the selected part of the multiple re-read reference voltages and multiple column height information, including:

[0068] Step S245a: Based on the multiple column height information in the information of multiple previous re-reads, select the position where the maximum column height information is located.

[0069] Step S245b: Based on the position where the maximum column height information is located, divide the multiple column height information in the information of multiple previous re-reads into two groups, and calculate the sum of the column height information in each group.

[0070] Step S245c: The group with the smaller sum of column height information is used as the selected part for quadratic function curve fitting.

[0071] As Figure 6 shown, in the second type of scenario, first determine the position of the maximum column height information. Based on the maximum column height information, divide the multiple column height information on both sides into two groups, that is, d 1 , d 2 is one group, and d 3 ~d 6 is one group. Calculate the sum of the column height information of the two groups, and use the group with the smaller sum of column height information as the fitting data for quadratic function curve fitting; specifically in Figure 6 , since the sum of d 3 ~d 6 is less than the sum of d 1 , d 2 , therefore, d 3 ~d 6 is used as the selected part and used as the fitting data to fit the quadratic function curve.

[0072] According to the second aspect of the present application, an electronic device is provided. Please refer to Figure 8 , Figure 8It is a schematic diagram of the framework of an embodiment of the electronic device of the present application; it includes a mutually coupled memory and a processor, and the processor is used to execute the program instructions stored in the memory to implement the above data rereading method. In a specific implementation scenario, the electronic device 80 may include, but is not limited to: a microcomputer, a server. In addition, the electronic device 80 may also include mobile devices such as a laptop computer, a tablet computer, etc., which are not limited here.

[0073] Specifically, the processor 82 is used to control itself and the memory 81 to implement the steps of any of the above embodiments of the training method of the image detection model, or to implement the steps in any of the above embodiments of the image detection method. The processor 82 may also be referred to as a CPU (Central Processing Unit, central processing unit). The processor 82 may be an integrated circuit chip with signal processing capabilities. The processor 82 may also be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. In addition, the processor 82 may be implemented jointly by integrated circuit chips.

[0074] Please refer to Figure 9 , Figure 9 It is a schematic diagram of the framework of an embodiment of the non-volatile computer-readable storage medium of the present application. The non-volatile computer-readable storage medium 90 stores program instructions 901 that can be run by the processor. When the program instructions 901 are executed by the processor, the steps in any of the above embodiments of the data rereading method are implemented.

[0075] In the above solution, according to the prior reread information, the number information of the differential data read during two adjacent rereads is obtained. From this number information, the read offset direction that can reduce the reread data error rate can be determined. Therefore, according to the read offset direction and the reread reference voltage in the prior reread process, the next reread reference voltage can be determined, and the next reread is performed, which can reduce the error rate of the next reread, that is, improve the success rate of data reading, and further reduce the data reading time consumption.

[0076] In some embodiments, the functions or modules included in the device provided by the embodiments of the present disclosure can be used to execute the methods described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments. For the sake of brevity, it will not be repeated here.

[0077] The descriptions of the various embodiments above tend to emphasize the differences between the various embodiments. Their similarities or resemblances can be referred to each other. For the sake of brevity, they will not be elaborated herein again.

[0078] In several embodiments provided in the present application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device implementation manners described above are merely illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there can be other division manners. For example, units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the couplings or direct couplings or communication connections shown or discussed with each other can be through some interfaces. The indirect couplings or communication connections of devices or units can be in electrical, mechanical or other forms.

[0079] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0080] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the methods in various embodiments of the present application. And the aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0081] Those skilled in the art will readily know that many modifications and variations can be made to the devices and methods while maintaining the teachings of the present application. Therefore, the above disclosure should be regarded as being limited only by the scope of the appended claims.

Claims

1. A data rereading method, applied to a memory, characterized in that, it includes: Recording information of multiple prior rereadings, wherein the information of the multiple prior rereadings includes multiple rereading reference voltages and multiple column height information for multiple rereadings of each read level of the same read page, and the column height information represents the number information of the difference data between the read data of two adjacent rereadings; Based on the multiple rereading reference voltages and multiple column height information for multiple rereadings of each read level, estimating the state wave information of each read level; Based on the estimated state wave information, determining the next rereading reference voltage of each read level and performing the next rereading.

2. The method according to claim 1, characterized in that, The estimated state wave information includes an estimated adjustment offset direction pointing to the trough of the state wave; wherein, the memory stores a rereading list, the rereading list records multiple rereading gears, each rereading gear is respectively used to record the rereading reference voltage under each read level of the same read page, and the memory performs a rereading operation with the rereading reference voltage under each read level corresponding to the selected rereading gear, and the information of the multiple prior rereadings is the information of multiple rereadings using multiple rereading gears in the rereading list.

3. The method according to claim 2, characterized in that, Based on the multiple rereading reference voltages and multiple column height information for multiple rereadings of each read level, estimating the state wave information of each read level includes: In response to the memory performing a level indication read between the read levels, comparing the multiple column height information for multiple rereadings of each read level, and estimating the adjustment offset direction of the next rereading, wherein the adjustment offset direction is towards the direction of column height decrease.

4. The method according to claim 2, characterized in that, Based on the multiple rereading reference voltages and multiple column height information for multiple rereadings of each read level, estimating the state wave information of each read level includes: In response to the memory performing a level indication read between the read levels, determining the rereading reference voltages corresponding to the rereading gears for multiple rereadings of each read level respectively, and determining the interval between two adjacent rereading reference voltages as the adjustment interval; Comparing two adjacent adjustment intervals, and estimating the estimated column height information corresponding to the adjustment interval with a smaller value based on the column height information corresponding to the adjustment interval with a larger value and the two adjustment intervals; Comparing the recorded column height information corresponding to the adjustment interval with a smaller value and the estimated column height information, and estimating the adjustment offset direction of the next rereading.

5. The method according to claim 2, characterized in that, Based on the estimated state wave information, determining the next rereading reference voltage of each read level and performing the next rereading includes: Based on the estimated adjustment offset direction, selecting the next rereading reference gear from the multiple rereading gears of each read level; Select the re-reading selection gear closest to the reference gear in the re-reading selection gears as the next re-reading gear, where the re-reading selection gear is another re-reading gear that conforms to the adjustment offset direction relative to the reference gear; Perform the next re-reading based on the corresponding re-reading reference voltages at each of the reading levels corresponding to the next re-reading gear.

6. The method according to claim 5, characterized in that selecting the re-reading selection gear closest to the reference gear in the re-reading selection gears as the next re-reading gear includes: Traverse the distances of all the re-reading selection gears relative to the reference gear in sequence, and select the re-reading selection gear with the closest distance as the next re-reading gear, where the distance of any re-reading selection gear relative to the reference gear is the square root of the sum of the squares of the differences between the corresponding re-reading reference voltages of the corresponding re-reading selection gear at each of the reading levels and the re-reading reference voltage of the reference gear at the corresponding reading level.

7. The method according to claim 1, characterized in that The estimated state wave information includes an estimated state wave fitting curve.

8. The method according to claim 7, characterized in that estimating the state wave information of each of the reading levels based on the multiple re-reading reference voltages and the multiple column height information obtained by performing multiple re-readings at each of the reading levels includes: judging the scene type based on the multiple column height information recorded by performing multiple re-readings at each of the reading levels; in response to the scene type conforming to the first type of scene, perform quadratic function curve fitting based on the multiple re-reading reference voltages and the multiple column height information recorded by performing multiple re-readings at each of the reading levels; in response to the scene type conforming to the second type of scene, screen the multiple re-reading reference voltages and the multiple column height information of each of the reading levels, and perform quadratic function curve fitting based on the selected part of the multiple re-reading reference voltages and the multiple column height information.

9. The method according to claim 8, characterized in that The judgment conditions of the scene type include: condition a, the smallest column height information in the previously recorded information of multiple re-readings is in the non-edge part; condition b, the largest column height information in the previously recorded information of multiple re-readings is in the non-edge part; The first type of scene includes a first sub-scene and a second sub-scene, where if condition a is satisfied and condition b is not satisfied, it is determined as the first sub-scene, indicating that the wave valley of the state wave is in the middle part of the previously recorded information of multiple re-readings; if condition a is not satisfied and condition b is not satisfied, it is determined as the second sub-scene, indicating that neither the wave peak nor the wave valley of the state wave is in the middle part of the previously recorded information of multiple re-readings; The second type of scenario includes a third sub-scenario and a fourth sub-scenario. Among them, if condition a does not hold and condition b holds, it is determined as the third sub-scenario, which represents that the peak of the state wave is in the middle part of the information read repeatedly multiple times before; if condition a holds and condition b holds, it is determined as the fourth sub-scenario, which represents that both the peak and the trough of the state wave are in the middle part of the information read repeatedly multiple times before.

10. The method according to claim 8, wherein, in response to the scenario type conforming to the second type of scenario, screening the multiple rereading reference voltages and the multiple column height information of each reading level, and performing quadratic function curve fitting based on the selected part of the multiple rereading reference voltages and the multiple column height information, including: selecting the position where the maximum column height information is located based on the multiple column height information in the information read repeatedly multiple times before; dividing the multiple column height information in the information read repeatedly multiple times before into two groups based on the position where the maximum column height information is located, and counting the sum of the column height information in each group; using the group with the smaller sum of the column height information as the selected part for quadratic function curve fitting.

11. The method according to claim 1, wherein, recording the information read repeatedly multiple times before includes: storing the first data read from the read page during the current rereading in the first buffer unit; storing the second data read from the read page during the previous rereading in the second buffer unit; storing the difference data between the first data and the second data in the third buffer unit to count the number of the difference data between the first data and the second data.

12. An electronic device, wherein, it includes a memory and a processor coupled to each other, and the processor is configured to execute program instructions stored in the memory to implement the data rereading method according to any one of claims 1 to 11.

13. A non-volatile computer-readable storage medium, on which program instructions are stored, wherein, the program instructions, when executed by a processor, implement the data rereading method according to any one of claims 1 to 11.

Images