WO2006046425A1 - 不揮発性記憶装置及び不揮発性記憶システム - Google Patents
不揮発性記憶装置及び不揮発性記憶システム Download PDFInfo
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- WO2006046425A1 WO2006046425A1 PCT/JP2005/019040 JP2005019040W WO2006046425A1 WO 2006046425 A1 WO2006046425 A1 WO 2006046425A1 JP 2005019040 W JP2005019040 W JP 2005019040W WO 2006046425 A1 WO2006046425 A1 WO 2006046425A1
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C16/00—Erasable programmable read-only memories
- G11C16/02—Erasable programmable read-only memories electrically programmable
- G11C16/06—Auxiliary circuits, e.g. for writing into memory
- G11C16/34—Determination of programming status, e.g. threshold voltage, overprogramming or underprogramming, retention
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C11/00—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor
- G11C11/56—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
- G11C11/5621—Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency using charge storage in a floating gate
- G11C11/5628—Programming or writing circuits; Data input circuits
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C2211/00—Indexing scheme relating to digital stores characterized by the use of particular electric or magnetic storage elements; Storage elements therefor
- G11C2211/56—Indexing scheme relating to G11C11/56 and sub-groups for features not covered by these groups
- G11C2211/564—Miscellaneous aspects
- G11C2211/5641—Multilevel memory having cells with different number of storage levels
Definitions
- Nonvolatile storage device and nonvolatile storage system are nonvolatile storage devices and nonvolatile storage system
- the present invention relates to a nonvolatile memory device using a nonvolatile semiconductor memory element capable of recording multi-value data.
- recording media for recording digital data such as music content and video data
- a magnetic disk, an optical disk, and a magneto-optical disk Such as a magnetic disk, an optical disk, and a magneto-optical disk.
- Semiconductor memory cards which are one of these recording media, use non-volatile semiconductor memory such as flash memory as storage elements and can be downsized, so small portable devices such as digital still cameras and mobile phone terminals can be used. It is spreading rapidly in the center.
- flash memory multi-value flash memory
- flash memory capable of storing data of multiple bits in one memory cell. According to this, not only can the recording density be increased and the recording capacity can be increased, but also the number of memory cells in the same recording capacity can be reduced, and the cost can be reduced.
- a recording method of the multilevel flash memory will be described.
- a nonvolatile semiconductor memory such as a flash memory stores data by injecting electrons into a floating gate (or trap gate) of a memory cell to change a threshold voltage of the memory cell.
- the threshold voltage of the memory cell increases when electrons are present in the floating gate and decreases when electrons are not present in the floating gate.
- FIG. 12 is a diagram showing a threshold voltage distribution of memory cells in a four-value flash memory.
- the threshold voltage of the memory cell is distributed in the displacement force of the regions LO, Ll, L2, and L3 according to the programmed data.
- the areas LO, Ll, L2, and L3i correspond to 2-bit data “11”, “10”, “00”, and “01”, respectively.
- each memory cell has a threshold voltage equal to the verification voltage V. Until V (W1, VV2, VV3) is exceeded. For example, when logic “10” is written in a memory cell, the program operation is repeated until the threshold voltage of the memory cell exceeds the verification voltage W1.
- the threshold voltage of each memory cell is set to one of the regions LO to L3
- Data is read by comparing the threshold voltage of the memory cell with reference voltages VR (VR1, VR2, VR3).
- the threshold voltage of the memory cell is lower than the reference voltage VR1, the data held in the memory cell is determined to be ⁇ 11 ⁇ .
- the threshold voltage of the memory cell is between the reference voltages VR1 and VR2, it is determined that the data held in the memory cell is “10”.
- the threshold voltage of the memory cell is between the reference voltages VR2 and VR3
- the data held in the memory cell is determined to be ⁇ 00 ⁇ .
- the threshold voltage of the memory cell is higher than the reference voltage VR3, it is determined that the data held in the memory cell is ⁇ 01 ⁇ .
- the erase operation of the memory cell is performed by setting the control gate of the memory cell to be erased to the ground potential, supplying a high voltage to the well region of the memory cell, and releasing the electrons accumulated in the floating gate. Done.
- a plurality of reference voltages VR (VR1 to VR3) are set between threshold voltage regions LO to L3, respectively.
- the read margin is the interval between the threshold voltage distribution edge and the reference voltage. Therefore, if the write characteristics of the memory cell change due to fluctuations in the semiconductor manufacturing process and the distribution 10 to 13 shifts, the read margin may be insufficient, causing malfunction.
- Patent Document 1 As a method for avoiding such an error during reading, there is a method disclosed in Patent Document 1.
- a program voltage generation circuit generates a plurality of program voltages in order to change the threshold voltage of each memory cell in accordance with the logic of write data.
- a plurality of reference values corresponding to a plurality of reference voltages for determining the threshold voltage of the memory cell are stored in the storage unit. At least one of the reference values stored in the storage unit can be rewritten.
- Reference voltage generation The circuit generates a reference voltage according to the reference value stored in the storage unit when reading data from the memory cell.
- the reference value for generating the reference voltage can be rewritten, the reference value can be changed according to the characteristics of the memory cell evaluated in advance. That is, the reference voltage can be changed after the semiconductor memory is manufactured. As described above, since the reference voltage can be changed according to the characteristics of the memory cell that changes due to variations in the manufacturing process, the data read margin from the memory cell can be improved, and the manufacturing yield can be improved.
- Patent Document 1 Japanese Patent Laid-Open No. 2003-263897
- the recording density can be increased by using the multilevel memory cell.
- the recording density is higher than that when the binary memory cell is used. If the read margin is too small! / ⁇ , the problem cannot be solved.
- the present invention has been made to solve the above-mentioned problems, and the object of the present invention is to ensure a large capacity equivalent to that in the case of using a multilevel memory cell and to achieve high reliability of 1 inch.
- An object of the present invention is to provide a non-volatile storage device and an access device thereof.
- the nonvolatile memory device of the present invention has the following configuration.
- a nonvolatile storage device is a nonvolatile storage device in which data can be written and read by an access device, and has a plurality of memory cells, and each memory cell has M threshold voltages (M> 3). And a non-volatile multi-level memory capable of storing multi-level data, and a memory controller for controlling data writing and reading with respect to the non-volatile multi-level memory.
- the memory controller uses the first control method that uses only N (N NM) threshold voltage distributions among the threshold voltage distributions of the memory cells of the nonvolatile multilevel memory, and all threshold voltages.
- a second control method using the distribution.
- the memory controller writes data in the first control method for data that cannot be accessed by the access device, and the data V can be accessed by the first control method. Let's write the data with.
- the memory controller may switch the control method by judging the type of data to be accessed. At that time, the memory controller determines whether the area where the data is recorded is a predetermined address area, and determines the type of data based on the determination result.
- the nonvolatile multi-level memory has a control method that uses only a part of the settable threshold voltage distributions among the settable threshold voltage distributions, so that the reference voltage margin at the time of reading is reduced. It can be enlarged and the reliability at the time of reading can be improved. It is also possible to switch between the first control method that uses only part of the settable threshold voltage distribution and the second control method that uses all of the settable threshold voltage distribution. Therefore, it is possible to improve the reliability at the time of reading while suppressing the reduction of the capacity of the nonvolatile memory device. In other words, high reliability equivalent to that when using binary memory cells can be realized as needed while securing a large capacity equivalent to that when using multilevel memory cells.
- FIG. 1 is a block diagram showing a configuration of a nonvolatile memory system according to Embodiment 1 of the present invention.
- FIG. 2 is a diagram showing a distribution of threshold voltage and cell number of data in a management data storage area in a nonvolatile memory device.
- FIG. 3 is a diagram showing the distribution of the threshold voltage of the data and the number of cells in the normal data storage area in the nonvolatile memory device.
- FIG. 4 is a block diagram showing a configuration of a nonvolatile memory system according to Embodiment 2 of the present invention.
- FIG. 6 A diagram showing the structure of a FAT area determination table.
- FIG. 8 is a diagram showing a memory cell array configuration of nonvolatile memory
- FIG. 9 A diagram showing an internal configuration of a physical block in the nonvolatile memory.
- FIG. 10A A diagram showing a configuration of a non-volatile memory in which physical pages are managed in a page group.
- FIG. 10B A diagram showing another configuration example of the non-volatile memory regarding a method of allocating memory cells to a physical page.
- Figure 11 Diagram showing the configuration of the shared cell table
- FIG. 12 is a diagram showing the distribution of the threshold voltage and the number of cells in a conventional nonvolatile memory device.
- FIG. 1 shows a configuration example of a memory system including a nonvolatile memory device and an access device that accesses the nonvolatile memory device according to the present invention.
- the memory system includes a nonvolatile storage device 3 that is a semiconductor memory card, and an access device 6 that is a host device that writes data to and reads data from the nonvolatile storage device 3.
- the nonvolatile storage device 3 includes a memory controller 4 and a nonvolatile memory 5.
- the memory controller 4 includes a host interface unit 41 that exchanges commands and data with the access device 6, and a read Z write control unit 42 that controls the nonvolatile memory 5.
- the non-volatile memory 5 is composed of an AND type flash memory.
- the nonvolatile memory 5 includes memory cells capable of recording quaternary data using a threshold distribution.
- Non-volatile The memory 5 includes a plurality of physical blocks having a predetermined size, which is a minimum unit for erasing data. Each physical block includes a plurality of pages of a predetermined size, which is the minimum unit for data writing.
- the non-volatile memory 5 has a two-page configuration (first page and second page). Details of the two-page configuration will be described later.
- the nonvolatile memory 5 includes a management data storage area 51 and a data storage area 52.
- the data storage area 52 is data that can be accessed by the user (hereinafter referred to as “normal data”), that is, the logical address is designated from the access device 6 and is written to or read from the nonvolatile memory 5. Data that can be done is recorded. File system information also exists in this area. In addition, a part of address management information that cannot be accessed by the user and a data valid flag are also present in this area 52.
- the management data storage area 51 stores information that cannot be accessed directly by the user, that is, information that cannot be accessed from the access device 6 by specifying a logical address.
- Information that cannot be directly accessed by the user includes a part of address management information, a data valid flag, and system information. Some of these pieces of information can be accessed by issuing a predetermined access command from the access device 6.
- the ratio of the file system information, address management information, data valid flag, and system information in the present embodiment to the total memory capacity is about 5%. In addition, it is not limited to this form of implementation, but in general, it is likely to be less than 5%.
- file system information Details of the file system information, address management information, data valid flag, and system information will be described below.
- the file system used in this embodiment is FAT16.
- file system information is written in a format compliant with the FAT16 standard.
- the file system information includes usable capacity and related information of each cluster which is a file system management unit. If file system information becomes inaccessible, data cannot be written or read. However, by formatting the file system, the information before formatting is discarded. New data can be written and read.
- the address management information includes logical / physical conversion data and bad block information.
- Logical conversion The data is used for logical address access from the access device 6 for the purpose of wear leveling, that is, the write and read are evenly distributed without concentrating on specific flash memory cells (physical addresses).
- the physical address information corresponding to the logical address is recorded.
- the address management information exists in both the data storage area 52 and the management data storage area 51.
- the address management information cannot be read, the physical address where the actual data is recorded cannot be specified, and the data cannot be read. In addition, there is a possibility that data is written illegally to a physical address that is in use. As described above, if the address management information cannot be accessed correctly, it cannot be used as a memory card, and the memory card cannot be recovered at the user level such as reformatting the file system, that is, a fatal state.
- the data validity flag is an identification flag indicating the validity of data. If data can be written without error, a flag is created and only the data with the valid flag written is treated as valid data. Also, if an error occurs during writing or if writing is interrupted due to a power failure, the flag is not created and it is treated as invalid data. In other words, if this information is read out in error, data that has no meaning is read out. Thus, if the data valid flag is illegally recognized, it cannot be used as a memory card and cannot be recovered at the memory card user level such as reformatting the file system, that is, a fatal state.
- the system information includes system information (storage capacity, standard version, performance, etc.) defined by the nonvolatile storage device 3 (semiconductor memory card) standard (for example, SD memory card standard) and the manufacturer (manufacturer).
- -Fatachiya 1 Includes unique system information. Since the access device 6 accesses the nonvolatile storage device 3 based on the system information, if a read error occurs, the nonvolatile storage device 3 itself cannot be used. In other words, if the system information cannot be read correctly, it cannot be restored at the memory card user level, such as reformatting the file system, that is, a fatal state.
- the file system information, address management information, data valid flag, and system information are the most important data when using the nonvolatile storage device 3, and particularly high reliability is required. It is said. In the present invention, especially for such information, writing is performed in such a way as to increase reliability during reading.
- the nonvolatile memory 5 is a four-value flash memory and has four threshold voltage distributions.
- the recording method (threshold voltage setting method) to the memory cell is varied depending on the type of data.
- data that requires relatively high reliability such as file system information, address management information, data validity flags, and system information
- a method for obtaining high reliability at the time of reading To record data to nonvolatile memory 5.
- the data to be recorded is converted so that it can be recorded using only two of the four threshold voltage distributions in the memory cell, and the data is written.
- a mode in which data is written and read using only two (partial) threshold voltage distributions is referred to as a “binary mode”.
- FIG. 2 shows the threshold voltage distribution of the memory cells in the quaternary flash memory when data is written and read in the binary mode.
- the binary mode is used when data that requires relatively high reliability such as file system information, address management information, data valid flags, and system information is written and read.
- the threshold voltage of each memory cell is distributed in one of the regions LO, Ll, L2, and L3 depending on the programmed data. Regions LO, Ll, L2, and L3 correspond to “11”, “10”, “00”, and “01” of 2-bit data, respectively.
- the threshold voltage distribution at the time of programming is basically set only in the region LO and the region L3.
- the threshold voltage of the memory cell is compared with each reference voltage VR1, VR2, VR3, VR4. If the threshold voltage at the time of reading is distributed in the region L1 due to an abnormal voltage setting at the time of writing, etc., it is treated as being distributed in the region LO. Treat as distributed.
- the reference voltage for determining the region LO is the voltage VR1.
- the data distributed in the region L1 is handled in the same way as the case where it is distributed in the region LO. Is effectively expanded to the voltage VR2, and the margin for reading data is expanded. Therefore, the reliability at the time of reading is improved in the same way as when using a binary flash memory.
- the reference voltage for the determination can be effectively expanded from the voltage VR3 to the voltage VR2, and the data reliability is increased.
- FIG. 3 is a diagram showing the threshold voltage distribution of the memory cells of the four-value flash memory when data is written and read in the multi-value mode.
- the multi-value mode is used when reading and writing normal data stored in the data storage area 52.
- the basic operation is the same as described in the background technology.
- a multi-value memory that can record four values is used.
- L value L> 4
- the two voltage distributions used need not be the lowest voltage distribution and the highest voltage distribution. In this case, there is no need to increase the threshold voltage up to the highest voltage, and as a result, the setting time of the threshold voltage can be shortened.
- At least two adjacent voltage distributions may be treated as the same voltage distribution, thereby making it possible to increase the read margin. In this case, it is not necessary to increase the threshold voltage to the highest voltage, and as a result, there is an effect that the setting time of the threshold voltage can be shortened.
- the number of threshold voltage distributions used for writing information that requires relatively high reliability is not limited to two. In other words, if the memory cell of the non-volatile memory 5 can be recorded with M value (M> 2), M threshold voltage distribution is used for relatively low and reliable enough information. Information that requires relatively high reliability may be written using only N (N NM) threshold voltage distributions. In other words, for information that requires relatively high reliability, only a part of the total available threshold voltage distribution may be used.
- Embodiment 1 the memory system shown in Embodiment 1 will be described in more detail.
- Figure 4 shows a more detailed configuration of the memory system.
- the memory controller 4 covers the host interface unit 41 and the read Z write control unit 42, and further temporarily stores the read data or write data with the data type determination unit 43 that determines the type of data. Buffer 48 to be stored. Further, the memory controller 4 has a FAT area determination table 44, a shared cell table 45, and a binary Z4 value management table 46 as information necessary for control.
- the FAT area determination table 44 manages information indicating an area for storing file system information (hereinafter referred to as “FAT area”).
- the shared cell table 45 manages information indicating whether the physical page is used in the binary mode or the multi-value mode in the page configuration of the nonvolatile memory.
- the binary Z4 management table 46 manages information on the logical address area used in the binary mode.
- FIG. 5 is a logical address map of the nonvolatile memory 5.
- the logical address is managed in 512B units called sectors, and there is a master boot record in the sector of logical address 0. Thereafter, the unused area, partition boot record, FAT1, FAT2, root directory, user in ascending order of logical address They are arranged in the order of the areas.
- This configuration is a logical map when the storage (storage device) is configured using the FAT file system that is used not only for memory cards but also for general hard disks.
- the master boot record In the master boot record, information related to the entire capacity of the nonvolatile memory 5 and address position information of the partition boot record are stored.
- the partition boot record stores information on the location and capacity of FAT1, FAT2, root directory, and user area, and information on what parameters should be used to control the nonvolatile memory 5.
- the master boot record and partition boot record are areas that can be rewritten when the nonvolatile memory 5 is formatted, but cannot be rewritten when normal data is written.
- FAT1 is occupied by individual file and directory entries located in the user area Are stored as chain information in units called clusters.
- FAT2 is the multiplexed information of FAT1.
- the root directory entry stores information on files and directory entries existing in the uppermost layer that can be stored in the nonvolatile memory 5 in a tree structure.
- the access device 6 manages FAT1, FAT2, and root directory entries using logical addresses in units of sectors.
- a file to be written in the nonvolatile memory 5 and directory entry data representing a tree structure of the file and the directory entry are written.
- files and directory entries are written in units of clusters consisting of multiple sectors.
- 32 sectors (16KB) are treated as one cluster, and the first cluster in the user area is cluster 2.
- the access device 6 manages user area data in units of clusters, it writes data in units of clusters (16 KB). However, management is performed using the cluster V, but when issuing commands to the non-volatile memory 5, it is converted to the sector logical address and issued.
- FIG. 6 is a diagram showing the configuration of the FAT area determination table 44.
- the FAT area determination table 44 manages information indicating an area for storing file system information. Specifically, the FAT area determination table 44 manages the location where the master boot record, partition boot record, FAT1, FAT2, and root directory are stored with the logical address of the sector. The area for storing each piece of file system information varies depending on the capacity of the nonvolatile memory 5. Therefore, the FAT area determination table 44 stores sector address numbers for each data type for each capacity of the nonvolatile memory. The FAT area determination table 44 is used to determine which type of data address the “read address” or “write address” transmitted from the access device 6 corresponds to.
- FIG. 7 is a diagram showing the configuration of the binary Z4 value management table 46.
- Binary Z4 value management table 46 manages logical addresses recorded in binary mode. By referring to the binary Z4 value management table 46, it can be determined whether or not the data of a certain logical address has been recorded in the binary mode.
- FIG. 8 is a diagram showing a memory cell array configuration of the nonvolatile memory 5.
- Non-volatile memory 5 It consists of multiple physical blocks PB0 to PB1023.
- a physical block is a unit for erasing data, and the size of one physical block is (256K + 8K) bytes. Therefore, the capacity of the entire nonvolatile memory 5 is (256M + 8M) bytes.
- FIG. 9 is a diagram showing an internal configuration of a physical block in the nonvolatile memory 5.
- a physical block consists of multiple physical pages PP0 to PP127.
- a physical page is composed of a 2K byte data area for writing data and a 64 byte management area for writing management information, and has a total size of (2K + 64) bytes.
- a physical page is a unit for writing data.
- the physical page constitutes a page group every two pages. Specifically, two pages are managed in order from the top as one page group, and in each group V, the first page is the first page, and the second page is the second page.
- the physical page PPO and the physical page PP1 are managed as one page group, which becomes the first page and the second page, respectively.
- physical page PP2 and physical page PP3 are managed as one page group, which becomes the first page and the second page, respectively.
- One memory cell of the nonvolatile memory 5 is shared by two types of physical pages (first page and second page) constituting the page group.
- first page and second page constituting the page group.
- the upper and lower bits held in one memory cell belong to different physical pages (first page, second page).
- FIG. 10A shows a configuration of the nonvolatile memory 5 in which physical pages are managed in the page group as described above.
- the area surrounded by the thick solid line corresponds to one memory cell.
- a memory cell can store four values, that is, two bits of information.
- a physical page PPO and a physical page PP1, a physical page PP2 and a physical page PP3,... Constitute a page group.
- Each bit on the first page corresponds to the lower bit of each memory cell
- each bit on the second page corresponds to the upper bit of each memory cell.
- bit DO of physical page PPO corresponds to the lower bit of memory cell C1
- bit DO of physical page PP1 corresponds to the upper bit of memory cell C1.
- the shared cell table 45 manages information indicating whether each physical page is the first page or the second page. From the shared cell table 45 in FIG. 11, it can be seen that the physical pages PP1, PP3, PP5,...
- the threshold voltage distribution of the erased memory cell is the distribution 10 in FIGS. Therefore, the data held in the lower bit of the memory cell corresponding to the first page is “1”, and the data held in the upper bit of the memory cell corresponding to the second page is also “1”.
- a write command is transmitted from the access device 6 to the nonvolatile memory device 3.
- the nonvolatile memory device 3 receives a write address (logical address) and write data together with a write command via the host interface unit 41.
- the received write data is temporarily stored in the buffer 48.
- the data type determination unit 43 refers to the FAT area determination table 44 and determines whether or not the received write address is included in the FAT area. At that time, the data type determination unit 43 determines the FAT area from the FAT area determination table 44 according to the capacity of the nonvolatile memory 5.
- the read Z write control unit 42 writes data to the nonvolatile memory 5 in the binary mode according to the determination result of the data type determination unit 43.
- the read Z write control unit 42 refers to the shared cell table 45 to search for a physical page with page information “1”, and writes the data to the searched physical page. If the searched physical page is already used, the next physical page with page information “1” is searched.
- the binary / quaternary management table 46 is updated for the logical address at that time. Setting of the threshold voltage distribution in the binary mode is as described in the first embodiment.
- the data type determination unit 43 determines whether the size of the write data is less than a predetermined size. If the size of the write data is smaller than the predetermined size as a result of the determination, the read Z write control unit 43 writes data to the nonvolatile memory 5 in the binary mode.
- the predetermined size is set equal to the data size of one cluster. If the data size is smaller than one cluster size, the data is considered to be special data, and it can be determined that it is not normal data! /.
- the read Z write control unit 42 is nonvolatile. Write data in memory 5 in multi-value mode. The setting of the threshold voltage distribution in the multi-value mode is as described in the first embodiment.
- a data read operation from the nonvolatile memory device 3 will be described.
- a read command is transmitted from the access device 6 to the nonvolatile memory device 3.
- the nonvolatile memory device 3 receives a read address (logical address) together with a read command via the host interface unit 41.
- the read Z write control unit 42 refers to the FAT area determination table 44 and determines whether or not the received read address is included in the FAT area. If the read address is included in the FAT area, it is determined that the data is written in the binary mode and the data is read in the binary mode. In binary mode, data is read from only the first page in the page group corresponding to the read address.
- the binary Z4 value management table 46 is referred to, and the data at the read logical address is recorded in either the binary mode or the multi-value mode. Judging. In binary mode, read data from the first page only. When the recording mode at the read address is the multi-value mode, data is read in the multi-value mode. In the multi-value mode, data is read from both the first page and the second page as necessary.
- the type of write data is determined, and data of a type that requires relatively high reliability, such as file system information, is recorded in binary, user data, etc. Even if the data is relatively low and reliable, it is recorded in four values for each type of data. Thereby, in particular, a read margin without separately providing a voltage generation circuit or the like can be increased. Therefore, it is possible to improve the reliability at the time of reading while suppressing the reduction of the capacity of the nonvolatile memory device without increasing the circuit scale and the manufacturing cost.
- system information such as system information and address management information for nonvolatile storage devices For data that is indispensable and important for operation, the reliability of the nonvolatile memory device at the time of recording Z reading can be increased.
- FIG. 10A In the configuration example of the nonvolatile memory shown in FIG. 10A, two physical pages are managed as a page group, and memory cells are shared within the page group.
- the configuration of the nonvolatile memory is as shown in FIG. 10B. But you can. Even in such a configuration, writing in two or four values can be realized.
- memory cells are not shared between physical pages.
- one memory cell forms a continuous storage area between adjacent memory cells as an area for storing 2 bits. That is, 4 memory cells are used to store 1 byte of data.
- either the upper bit or the lower bit of the memory cell is used. That is, either a sequence of bits DO, D2, D4,... Or a sequence of bits Dl, D3, D5,. That is, one memory cell forms a continuous storage area between adjacent memory cells as an area for storing one bit. For this reason, in the binary mode, 8 memory cells are required to store 1 byte of data.
- the shared cell table 45 does not require force.
- information indicating whether the bit in the memory cell in which valid data is recorded is the upper bit or the lower bit is separately provided. It is necessary to remember.
- the read margin can be increased as in the case of the binary value while using the multi-level flash memory, and the reliability at the time of reading is increased. Can be improved. In particular, it is possible to improve the reliability at the time of reading by judging the type of data and recording only a part of the threshold voltage values that can be set for data of relatively high importance. . In addition, since data of relatively low importance is recorded as a multi-value memory cell using all threshold voltages as usual, the recording density, that is, the recording capacity is not reduced. In addition, there is no need to provide a separate voltage generation circuit, etc., increasing the circuit scale and manufacturing cost. Can be suppressed.
- the present invention can be applied to an information recording medium that is used in electronic devices such as digital AV equipment, mobile phone terminals, personal computers, and the like and that requires large capacity and high reliability.
- the present invention is suitable for a non-volatile memory device that requires low cost because a multi-level flash memory capable of increasing the recording density can be used.
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Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2008084316A (ja) * | 2006-09-27 | 2008-04-10 | Samsung Electronics Co Ltd | 異種セルタイプを支援する不揮発性メモリのためのマッピング情報管理装置および方法 |
JP2009104729A (ja) * | 2007-10-24 | 2009-05-14 | Toshiba Corp | 不揮発性半導体記憶装置 |
JP2010518546A (ja) * | 2007-02-16 | 2010-05-27 | モサイド・テクノロジーズ・インコーポレーテッド | ダイナミックマルチモード動作を有する不揮発性メモリ |
JP2011504277A (ja) * | 2007-11-21 | 2011-02-03 | マイクロン テクノロジー, インク. | Mビットメモリセル用のm+nビットプログラミングおよびm+lビット読出し |
KR20110095299A (ko) * | 2008-11-17 | 2011-08-24 | 기제케 운트 데브리엔트 게엠베하 | 휴대용 데이터 캐리어의 메모리에 데이터를 시큐어하게 저장하는 방법 |
JP2012109012A (ja) * | 2006-08-05 | 2012-06-07 | Benhov Gmbh Llc | 固体記憶素子及び方法 |
JP5223869B2 (ja) * | 2008-01-16 | 2013-06-26 | 富士通株式会社 | 半導体記憶装置、制御装置、制御方法 |
JP2013196673A (ja) * | 2012-03-23 | 2013-09-30 | Toshiba Corp | メモリシステム |
Families Citing this family (2)
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JP2014175031A (ja) * | 2013-03-08 | 2014-09-22 | Toshiba Corp | 半導体記憶装置 |
JP2018160303A (ja) | 2017-03-23 | 2018-10-11 | 東芝メモリ株式会社 | 半導体記憶装置 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0652691A (ja) * | 1992-07-30 | 1994-02-25 | Toshiba Corp | 半導体ディスク装置 |
JP2000173281A (ja) * | 1998-12-04 | 2000-06-23 | Sony Corp | 半導体記憶装置 |
JP2001210082A (ja) * | 2000-01-24 | 2001-08-03 | Mitsubishi Electric Corp | 不揮発性半導体記憶装置およびデータ記憶システム |
-
2004
- 2004-10-29 JP JP2004315451A patent/JP2008020937A/ja active Pending
-
2005
- 2005-10-17 WO PCT/JP2005/019040 patent/WO2006046425A1/ja not_active Application Discontinuation
- 2005-10-24 TW TW094137150A patent/TW200629292A/zh unknown
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0652691A (ja) * | 1992-07-30 | 1994-02-25 | Toshiba Corp | 半導体ディスク装置 |
JP2000173281A (ja) * | 1998-12-04 | 2000-06-23 | Sony Corp | 半導体記憶装置 |
JP2001210082A (ja) * | 2000-01-24 | 2001-08-03 | Mitsubishi Electric Corp | 不揮発性半導体記憶装置およびデータ記憶システム |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2012109012A (ja) * | 2006-08-05 | 2012-06-07 | Benhov Gmbh Llc | 固体記憶素子及び方法 |
JP2008084316A (ja) * | 2006-09-27 | 2008-04-10 | Samsung Electronics Co Ltd | 異種セルタイプを支援する不揮発性メモリのためのマッピング情報管理装置および方法 |
US8391064B2 (en) | 2007-02-16 | 2013-03-05 | Mosaid Technologies Incorporated | Non-volatile memory with dynamic multi-mode operation |
JP2010518546A (ja) * | 2007-02-16 | 2010-05-27 | モサイド・テクノロジーズ・インコーポレーテッド | ダイナミックマルチモード動作を有する不揮発性メモリ |
US8767461B2 (en) | 2007-02-16 | 2014-07-01 | Conversant Intellectual Property Management Inc. | Non-volatile memory with dynamic multi-mode operation |
US8553457B2 (en) | 2007-02-16 | 2013-10-08 | Mosaid Technologies Incorporated | Non-volatile memory with dynamic multi-mode operation |
JP2009104729A (ja) * | 2007-10-24 | 2009-05-14 | Toshiba Corp | 不揮発性半導体記憶装置 |
JP2011504277A (ja) * | 2007-11-21 | 2011-02-03 | マイクロン テクノロジー, インク. | Mビットメモリセル用のm+nビットプログラミングおよびm+lビット読出し |
JP5223869B2 (ja) * | 2008-01-16 | 2013-06-26 | 富士通株式会社 | 半導体記憶装置、制御装置、制御方法 |
JP2012508917A (ja) * | 2008-11-17 | 2012-04-12 | ギーゼッケ ウント デフリエント ゲーエムベーハー | 携帯型データキャリアのメモリにデータを安全に格納する方法 |
KR20110095299A (ko) * | 2008-11-17 | 2011-08-24 | 기제케 운트 데브리엔트 게엠베하 | 휴대용 데이터 캐리어의 메모리에 데이터를 시큐어하게 저장하는 방법 |
US8838925B2 (en) | 2008-11-17 | 2014-09-16 | Giesecke & Devrient Gmbh | Method for securely storing data in a memory of a portable data carrier |
KR101590214B1 (ko) | 2008-11-17 | 2016-01-29 | 기제케 운트 데브리엔트 게엠베하 | 휴대용 데이터 캐리어의 메모리에 데이터를 시큐어하게 저장하는 방법 |
JP2013196673A (ja) * | 2012-03-23 | 2013-09-30 | Toshiba Corp | メモリシステム |
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