CN100533409C - Memory controller, nonvolatile memory, nonvolatile memory system, and nonvolatile memory address management method - Google Patents
Memory controller, nonvolatile memory, nonvolatile memory system, and nonvolatile memory address management method Download PDFInfo
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Abstract
For address management of a nonvolatile memory, the whole logical address space is divided into logical address ranges (0 to 15), and the physical address space is divided into physical areas (segments (0 to 15)). The logical address ranges are respectively associated with the physical areas (segments) to manage the addresses. The sizes of the logical address ranges are equalized. The size of the physical area (segment (0)) corresponding to the logical address range (0) in which data of high rewrite frequency such as an FAT is expected to be stored is larger than those of the other physical areas, and the logical address ranges and the physical areas are allocated. Alternatively, the sizes of the physical areas are equalized, and the size of the logical address range (0) is set as a smaller one than those of the other logical address ranges. With this, the actual rewrite frequencies of the physical areas (segments) are equal to one another, and consequently the life of the nonvolatile memory can be prolonged.
Description
Technical field
The address management method that the present invention relates to be used to control the Memory Controller of the nonvolatile memory such as flash memories and be used for this nonvolatile memory.The invention still further relates to non-volatile memory device, and to the Nonvolatile memory system that writes from this nonvolatile memory with reading of data.
Background technology
To comprising rewritable nonvolatile memory, the demand that mainly is the non-volatile memory device of semiconductor memory card increases day by day, and these non-volatile memory devices are as being provided with the external record equipment that personal computer (PC) is the real time record device use of representative for the non real-time pen recorder of representative with the digital camera.Various types of semiconductor memory cards are arranged at present, and a kind of in these semiconductor memory cards is SD (secure digital (trade mark)) storage card.
This SD storage card comprises the flash memories and the Memory Controller that is used to control flash memories as nonvolatile memory.Memory Controller response from the access device such as PC, be used to the order reading and write, control from read and write to flash memories.
Consider that this SD card is loaded onto the situation of the access device such as PC, make the SD card be considered to the dish that can move with respect to access device, and by being used for the file system management to the FAT of its access data.Utilize the FAT system,, typically use file allocation table (FAT) in the process of recording unit log file or data, by bunch the basis on read and write data.
The flash memories of the main storing memory of conduct comprises a plurality of physical blocks as erase unit in semiconductor memory card, and each physical block comprises the page or leaf as writing unit.Adopt the semiconductor memory card of this flash memories to exist the particular problem that can be restricted to the number of times that writes data wherein.Though this has been made improvement by the new memory technology, with regard to reliability of data storage, using under the situation of semiconductor memory card as External memory equipment, this semiconductor memory card is perfect not enough.Therefore, in this semiconductor memory card, exist the management data reliability, and the needs that read and write reliability of data.
Usually, in semiconductor memory card, prepare replace block, replace the bad piece that causes the read/write mistake, so that improve reliability with replace block.In addition, for the rewriting that prevents data concentrates on certain specific physical block, adopted the address management method such as consuming balanced (wear leveling).Consume equilibrium and be convert logical address in the flash memories physical address by the access device appointment so-called logic to the physical address translations technology, and utilize address administration table to realize usually.
As a kind of consumption equalization methods, what adopt traditionally is the decentralized address management method.The decentralized address management method is a kind of when initialization, the status indication of pre-stored logical address and corresponding blocks in as the directorial area of the page or leaf of the unit of writing, read the information of pre-stored, and according to calculated address admin table among the RAM of the information that reads in Memory Controller.
Yet, have at non-volatile memory device under the situation of high capacity storage space, when initialization, above-mentioned consumption equalization methods need read the directorial area in the whole storage space the extremely long time period.This may specification violation, for example, makes initialization time surpass the upper limit in the standard of initialization time of the non-volatile memory device that is exceeded by this way.In addition, even do not have at non-volatile memory device under the situation of specific specifications, above-mentioned consumption equalization methods has caused the shortcoming that increases the stand-by period, but till non-volatile memory device becomes access, even this does not have specification violation.In addition, need the RAM of interim memory address admin table to have great capacity, cause the problem that increases cost thus.
In order to overcome the problems referred to above, the memory device of describing in the patent documentation 1 (* *) has adopted the combination of (1) sectional management method and these two kinds of technology of (2) concentrated address management method.
To be a kind of handle be divided into a plurality of ranges of logical addresses (zone) by the whole logical address space of address device management to the sectional management method, and manage the method for these a plurality of ranges of logical addresses explicitly with a plurality of physical areas (segmentation) that generate in flash memories by physically dividing flash memories.
On the other hand, the concentrated address management method be a kind of in flash memories pre-stored address admin table itself, response is from each time write command of access device, read the address administration table among the RAM, upgrade the address administration table among the RAM, and after data write end, it is rewritten to the method for flash memories.
* patent documentation 1:JP-A-2003-323352
Summary of the invention
The problem to be solved in the present invention
In traditional non-volatile memory device, as shown in figure 17, physical space is divided into the segmentation (physical areas) with identical size.Because each segmentation in the physical areas has identical size, data can be rewritten same number to each segmentation.On the other hand, logical space also is divided into onesize.
The frequent degree height that the frequent degree that file allocation table (FAT) is rewritten is rewritten than other data.In addition, this document allocation table is written to the Head Section (for example, the ranges of logical addresses among Figure 17 0) of address realm.
Have the data rewritten more continually, FAT for example, situation under, with than other ranges of logical addresses (ranges of logical addresses 1 to 15) more continually access comprise the ranges of logical addresses (ranges of logical addresses 0) of these data.Therefore, the segmentation (segmentation 0) corresponding with address realm 0 earlier reaches than other segmentation (segmentation) and can rewrite the life-span, causes when segmentation 0 reaches its life-span, even also have spendable memory block, the problem that non-volatile memory device also becomes and can not use.
Make the present invention in view of above-mentioned traditional problem, the object of the present invention is to provide the technology of the non-volatile memory device that can realize improving its life-span.
The technological means of dealing with problems
Memory Controller according to the present invention order that to be a kind of basis provide from the external access device and logical address to the controller that writes from nonvolatile memory with reading of data.Described Memory Controller comprises: the read/write controller, be used for control from read and write data to described nonvolatile memory; And address management section, be used for whole logical address space is divided into a plurality of ranges of logical addresses, each ranges of logical addresses is carried out address administration, the memory block of described nonvolatile memory physically is divided into a plurality of physical areas, makes described ranges of logical addresses and described physical areas manage described ranges of logical addresses and described physical areas explicitly; Wherein said address management section comprises: the district distributes part, be used for determining the distribution of described ranges of logical addresses and described physical areas, make that the ranges of logical addresses size of at least one ranges of logical addresses is different with the ratio of physical areas size with the ranges of logical addresses size of other ranges of logical addresses with the ratio of physical areas size.
The district distributes the part can be so that the big or small identical mode assign logical addresses scope of each ranges of logical addresses, so that the mode that varies in size of the size of at least one physical areas and other physical areas is distributed physical areas.In this case, can be provided with and store than the size of other physical areas greatly by the ranges of logical addresses corresponding physical district of the data of more frequent rewriting size.
As an alternative, district's distribution part can be so that the big or small identical mode of each physical areas be distributed physical areas, so that the mode assign logical addresses scope that varies in size of the size of at least one ranges of logical addresses and other ranges of logical addresses.In this case, can be provided with and store by the ranges of logical addresses of the data of more frequent rewriting slight greatly than other ranges of logical addresses.
By the data of more frequent rewriting can be the management information that is used for the file of management such as file allocation table (FAT).
Non-volatile memory device according to the present invention comprise nonvolatile memory and above-described to the Memory Controller that writes from nonvolatile memory with reading of data.
Non-volatile memory device according to the present invention comprises above-mentioned non-volatile memory device, comes the memory storage of this non-volatile memory device of access by appointment logical address wherein.
Nonvolatile memory does not provide a kind of according to address management method of the present invention, described nonvolatile memory comprises a plurality of physical blocks, and be applicable to according to the order that provides from access device and logical address to write and reading of data from nonvolatile memory.Described method comprises step: whole logical address space is divided into a plurality of ranges of logical addresses, each ranges of logical addresses is carried out address administration; The memory block of described nonvolatile memory physically is divided into a plurality of physical areas, makes described ranges of logical addresses and described physical areas manage described ranges of logical addresses and described physical areas explicitly; Determine the distribution of described ranges of logical addresses and described physical areas, make that the ranges of logical addresses size of at least one ranges of logical addresses is different with the ratio of physical areas size with the ranges of logical addresses size of other ranges of logical addresses with the ratio of physical areas size.
Technique effect of the present invention
According to the present invention, ranges of logical addresses and segmentation are distributed, make the ratio of ranges of logical addresses and segmentation at ranges of logical addresses with higher rewrite frequencies with different at the ratio of other ranges of logical addresses.Rewrite frequencies that like this can balanced each segmentation, thus life-span of non-volatile memory device prolonged.
Description of drawings
Fig. 1 is the block scheme of expression according to the configuration of the whole Nonvolatile memory system of first embodiment of the invention.
Fig. 2 is the synoptic diagram of expression according to the Storage Mapping figure of corresponding relation between the logical address space of first embodiment of the invention and the physical address space.
Fig. 3 represents according in the non-volatile memory device of the present invention the synoptic diagram of the physical block in the nonvolatile memory.
Fig. 4 represents according to first embodiment of the invention the synoptic diagram of the physical areas admin table in non-volatile memory device.
Fig. 5 represents according to first embodiment of the invention the synoptic diagram of the logical address translation table in non-volatile memory device.
Fig. 6 represents according to first embodiment of the invention the synoptic diagram of the Storage Mapping figure of the district's allocation table in non-volatile memory device.
Fig. 7 is that expression is according to first embodiment of the invention, at the synoptic diagram of the address format of the logic sector sequence number LSN (logical sector address) of non-volatile memory device and the corresponding relation between the physical sector sequence number PSN (physical sector address).
Fig. 8 represents according to first embodiment of the invention, is distributed the processing flow chart that partly carries out by the district in the non-volatile memory device.
Fig. 9 be expression according to first embodiment of the invention, the processing flow chart that partly carries out by the address translation in the non-volatile memory device.
Figure 10 is the block scheme of expression according to the configuration of the whole Nonvolatile memory system of second embodiment of the invention.
Figure 11 is the synoptic diagram of expression according to the Storage Mapping figure of corresponding relation between the logical address space of second embodiment of the invention and the physical address space.
Figure 12 represents according to second embodiment of the invention the synoptic diagram of the physical areas admin table in non-volatile memory device.
Figure 13 represents according to second embodiment of the invention the synoptic diagram of the logical address translation table in non-volatile memory device.
Figure 14 represents according to second embodiment of the invention the synoptic diagram of the Storage Mapping figure of the district's allocation table in non-volatile memory device.
Figure 15 represents according to second embodiment of the invention, is distributed the processing flow chart that partly carries out by the district in the non-volatile memory device.
Figure 16 be expression according to second embodiment of the invention, the processing flow chart that partly carries out by the address translation in the non-volatile memory device.
Figure 17 is the synoptic diagram of expression according to the Storage Mapping figure of corresponding relation between the logical address space of traditional embodiment and the physical address space.
＜reference number 〉
200: access device
201: host interface
202: buffer memory
203：CPU
204：RAM
205：ROM
206,206b: the district distributes part
207,207b: district's allocation table
208,208b: address translation part
209,209b: physical areas admin table
210,210b: logical address translation table
211: the read/write controller
215,215b: address management section
220: Memory Controller
230: nonvolatile memory
240,240b: Nonvolatile memory system
Embodiment
Below with reference to the Nonvolatile memory system of accompanying drawing description according to embodiment of the present invention.
First embodiment
1.1 system configuration
Fig. 1 is the synoptic diagram of expression according to the configuration of the Nonvolatile memory system of first embodiment of the invention.Nonvolatile memory system comprises access device 200 and is write and from the non-volatile memory devices 240 of its reading of data to it by access device 200.
The district distributes part 206 to comprise district's allocation table 207, and address translation part 208 comprises physical areas admin table 209 and logical address translation table 210.
The district distributes part 206 that the ranges of logical addresses in the logical address space is associated with segmentation in the physical address space.Ranges of logical addresses and segmentation are described below.
Fig. 2 shows the Storage Mapping figure of appointment according to corresponding relation between the logical address space of first embodiment and the physical address space.Logical address space be by access device 200 write with reading of data in the address space of appointment, physical address space is the space of the physical address of the nonvolatile memory 230 such as flash memories.In the present embodiment, logical address space is divided into 16 scopes, and as ranges of logical addresses 1 to 15, and physical address space is divided into 16 segmentations, as segmentation 0 to 15.Each segmentation comprises a plurality of physical blocks, and the size of the physical block that each is single is the 16k byte.In same figure, the sum of the physical block that comprises among PBtn (S) the indication segmentation S.Physical block opens start sequence number among PBsn (S) the indication segmentation S.S is the integer in 0 to 15 scope.The district distributes part 206 that range of physical addresses shown in Figure 2 is associated with segmentation.
Return Fig. 1, the district that address translation part 208 distributes part 206 to carry out according to the district distributes the definite address such as data write destination-address (will write the data place) of processing.Read/write controller 211 to write and reading of data from physical address by 208 appointments of address translation part.
District's allocation table 207 can be stored in the non-volatile ram (not shown) that is incorporated in district's distribution part 206, also can be stored in the nonvolatile memory 230, and can read in non-volatile ram when non-volatile memory device 240 initialization.For convenience of description, present embodiment is based on the prerequisite of district's allocation table 207 of storing in the non-volatile ram.
One group of physical areas admin table 209 of storage and logical address translation table 210 in each segmentation in nonvolatile memory 230, single group physical areas admin table 209 and logical address translation table 210 are provided, are used to manage the address in the corresponding single split scope.Hereinafter, all groups of physical areas admin table 209 and logical address translation table 210 are referred to as " address administration table ".
Fig. 3 is the configuration schematic diagram of physical block in the nonvolatile memory 230.The single physical piece comprises 32 pages, and every page is made of the data field of 512 bytes and the directorial area of 16 bytes.Can store the data of 16k byte (512 bytes * 32 page) in the single physical piece.Under the situation that writes single bunch (corresponding to single logical block), data are write 0 to 31 page district in the single physical piece in order.In the directorial area of page or leaf 0, store the Decentralization information of relevant physical block.Decentralization information comprises the bulk state by the logical block sequence number of access device 200 appointments and indication physics bulk state.When nonvolatile memory 240 initialization, each physical block that comprises from nonvolatile memory 230 district corresponding with fragment sequence number S reads Decentralization information, generates and store the address administration table at segmentation S then in the zone of segmentation S.
Fig. 4 is the synoptic diagram of expression physical areas admin table 209.In Fig. 4, the address of each of physical areas admin table 209 is corresponding to the physical block sequence number PBN (S) among the segmentation S in the nonvolatile memory 230.Physical areas admin table 209 is stored " effectively " at each physical block, engineering noise, the information of relevant its state (bulk state) such as " bad " conduct.More particularly, binary value " 00 " indication is as the active block that is written into the piece of valid data.Binary value " 11 " indication is from its obliterated data or write data, but these data are unnecessary invalid block.Binary value " 10 " indication conduct is because the bad piece that the entity mistake of memory cell value etc. cause piece to use.Binary value " 01 " indication physical block memory address admin table.As mentioned above, there are four kinds of states of indication.
Fig. 5 shows the synoptic diagram of logical address translation table 210.In Fig. 5, the every address of logical address translation table 210 is corresponding to the logical block sequence number LBN (S) among the segmentation S.In the address area, storage and logical block sequence number LBN (S) corresponding physical piece sequence number PBN (S).
Fig. 6 shows the memory map of district's allocation table 207.The district every address in the address area, stores the total PBtn (S) of the physical block among each segmentation S of the physical block start sequence number PBsn (S) of each corresponding segments S and correspondence corresponding to fragment sequence number S in the allocation table 207.In other words, district's allocation table 207 comprises the part of the start sequence number PBsn (S) that stores physical block and the part of storing the total PBtn (S) of physical block.The former is corresponding to the start address of each segmentation, and the latter indicates the sum of the physical block that constitutes each segmentation.
Fig. 7 shows the address format of corresponding relation between indication logic sector sequence number LSN (logical sector address) and the physical sector sequence number PSN (physical sector address).Page number in the corresponding physical block of the bit 0 to 4 of logic sector sequence number LSN (LSN[4:0]) (PSN[4:0]).Bit 20 to the 5 counterlogic piece sequence number LBN of logic sector sequence number LSN.Logical block sequence number LBN corresponding bunch number.The district distributes part 206 to carry out the allocation process of going shown in Fig. 6 according to logical block sequence number LBN.
1.2 operation
The operation of the non-volatile memory device 240 with above-mentioned configuration is described below.
1.2.1 basic operation
When using non-volatile memory device 240 for the first time after shipment, the non-bad piece of all in the nonvolatile memory 230 all is in erase status.Yet, in each segmentation, in the single physical piece of the final address of each segmentation, stored the address administration table that respectively provides for the address of managing in each segmentation.At this moment, in physical region admin table 209, comprise the address administration table physical block of physical areas admin table 209 at storage, promptly at the physical block of final address, status indication is set to " 01 ", and the status indication that is provided with at bad physical block is set to " 10 ".Though the system region of physical presence storing system information, this does not relate to notion of the present invention, in the description of this omission to it.
After nonvolatile memory 240 energisings, CPU203 carries out initialization process according to program stored among the ROM205, and enters the state of wait from the orders such as reading, write of access device 200.
After this, access device 200 produces the order that writes desirable ranges of logical addresses.So-called content-data such as view data (hereinafter referred is " data ") can be write all ranges of logical addresses, and FAT can only be written into ranges of logical addresses 0.When writing data or FAT, read address stored admin table in the segmentation the nonvolatile memory corresponding 230 with writing the destination ranges of logical addresses from single physical piece in this segmentation final address.According to the address administration table that reads, produce physical areas admin table 209 and logical address translation table 210, then they are stored among the RAM in the address translation part 208.
In the process that writes data or FAT, determine to write the destination physical block according to physical areas admin table 209 and logical address translation table 210, and data or FAT are write physical block.After writing data or FAT so far, physical areas admin table 209 and logical address translation table 210 that address translation part 208 is upgraded among the RAM, and they are overwritten in the nonvolatile memory 230.Because it is balanced that the physical block of memory address admin table also is subjected to consuming, when writing data or FAT, change the physical block that rewrites address administration table to it, the back will be described this.
In this case, for convenience of description, write based on following prerequisite.
＜write prerequisite 〉
(1) non-volatile memory device has the 2MB/ writing speed of second.
(2) during 1 second data write, FAT was written into once.
(3) write and single bunch of (16k byte) corresponding data at single write command.
(4) FAT is with FAT1 and dualization of FAT2, the capacity that respectively has the 16k byte, and therefore, the total volume of FAT is the 32k byte.Write FAT at single write command corresponding to the 32k byte.
(5) size of physical block is 16k byte (referring to Fig. 3).
(6) incidence of bad piece is 2% in the nonvolatile memory 230, and the incidence of bad piece also is 2% in each segmentation.
(7) be stored in together in physical region admin table 209 (about 1k byte) and the single physical piece of logical address translation table 210 (about 8k byte) in associated fragment.These tables that are stored together are called as " address administration table ".
(8) the individual address admin table is stored in the nonvolatile memory 230 in the single physical piece in each segmentation.For each access of access device 200, read the address administration table among the RAM in the address translation part 208, generate physical areas admin table 209 and logical address translation table 210 then.Write after data or the FAT, upgrade physical areas admin table 209 and logical address translation table 210 among the RAM, in the physical block different, they are rewritten as the address administration table of renewal then with above-mentioned physical block.
1.2.2 consider to rewrite frequent degree
Compare with traditional non-volatile memory device, under situation about writing, consider the frequent degree that each segmentation in non-volatile memory device rewrites according to first embodiment of the invention according to above-mentioned predetermined condition.
＜traditional non-volatile memory device 〉
As shown in figure 19, traditional non-volatile memory device comprises the segmentation with identical size, therefore, to whole logical space, be in the zone of about 1GB byte, under the situation of overwriting data, to the frequency ratio of segmentation 0 overwriting data of storage FAT to the frequency height of other segmentation overwriting data.
More particularly, at first, if rewrite whole logical space, promptly approximately in the zone of 1GB byte, all data of storage, the quantity that is rewritten the physical block in each segmentations of data is 3968, with constitute corresponding ranges of logical addresses bunch quantity equal.According to precondition (1) and equation (1), rewriteeing the required time period is 512 seconds.
The 1[GB byte]/2[MB/ second]=512[second] (1)
According to precondition (2), (4) and (5), FAT during 512 seconds (32 byte) is rewritten 512 times.Because FAT only is assigned to segmentation 0, in the rewriting period of FAT, according to following equation (2), the quantity of physical block is 1024 in the segmentation 0 of its rewriting FAT.
(the 32[k byte]/the 16[k byte]) * 512[time]=1024 (2)
Because segmentation 1 to 15 includes only data,, it is 0.97 time to the frequency of each physical block overwriting data according to equation (3).
Inferior 3968/4096=0.97 (3)
On the other hand, because segmentation 0 comprises data and FAT, according to equation (4), the frequency of each physical block overwriting data or FAT is 1.22 times in segmentation 0.In this case, "-2 " of equation (4) left-hand side are corresponding to deducting 2 bunches at FAT1 and FAT2.
(3968-2+1024)/4096 ≌ 1.22 times (4)
Verified from equation (3) and (4), the frequency ratio that rewrites to segmentation 0 causes segmentation 0 to reach the assurance number of times (for example, 100,000 times) of rewriting earlier to the frequency height that other segmentation rewrites.The life-span that this means this conventional non-volatile memory device equals the speed that segmentation 0 reaches the assurance number of times of rewriting.
＜according to the non-volatile memory device of first embodiment of the invention 〉
In non-volatile memory device 240 according to first embodiment of the invention, regulatory region distributes, the segmentation 0 that feasible quilt rewrites more continually comprises the physical block of bigger quantity than other segmentation, so that on average each segmentation reaches and rewrites the speed that guarantees number of times, with life-saving.
In other words, in the non-volatile memory device 240 according to present embodiment, as shown in Figure 2, the size of the segmentation 0 that is rewritten more continually is bigger than the size of other segmentation 1 to 15.The calculating of fragment size is according to the occurrence rate of bad piece in the nonvolatile memory 230, framework of Memory Controller etc. and changing.In the present embodiment, each ranges of logical addresses is determined as follows.The key concept of determining is as far as possible little based on the size of the segmentation 1 to 15 of setting except that segmentation 0, and is maximum as far as possible with the size of guaranteeing segmentation 0.
More particularly, at first, determine the quantity of segmentation 1 to 15 physical block in each according to equation (5).In equation (5), coefficient 0.02 is that " 1 " of left-hand side is corresponding to the single physical piece of memory address admin table corresponding to the coefficient of bad piece incidence in the nonvolatile memory 230 (for example, 2%).
{(3968+1)/(1-0.02)}＝4050 (5)
In other words, consider the incidence of bad piece, the size of each in the segmentation 1 to 15 is set to required minimal size.
Next, determine the quantity of physical block in the segmentation 0 according to equation (6).
65536-(4050 * 15 segmentation)=4786 (6)
In this case, " 65536 " are the sums of physical block in the nonvolatile memory 230.In the present embodiment, in order to make explanation for simplicity, there is not to consider district not directly related with the present invention such as system region.
In view of the above, according to following equation, the frequency of each the physical block overwriting data in segmentation 1 to 15 is 0.98.
According to following equation, the frequency of each the physical block overwriting data in segmentation 0 is 1.04.
(3968-2+1024)/4786 ≌ 1.04 times (8)
Aforementioned calculation result shows, according to present embodiment, compared with prior art, can obviously reduce the rewrite frequencies to segmentation 0, in addition, compared with prior art, has also reduced the difference in the rewrite frequencies between segmentation 0 and other segmentation 1 to 15.Therefore, in the present embodiment, can balanced rewrite frequencies, thus the serviceable life of improving nonvolatile memory 230.
Determine the physical boundary of each segmentation according to equation (5) and (6), relevant therewith information stores is in the district distributes non-volatile ram in the part 206, as district's allocation table 207 as shown in Figure 6.Can when initialization, will distinguish allocation table 207 and be stored in any physical block in the nonvolatile memory 230, and can from its physical block, read district's allocation table to RAM.Can in the subregion of district's distribution part 206 and RAM204, provide RAM.
1.2.3 the processing that address management section carries out
Describe below at access device 200 and produce under the situation of the order that rewrites a cluster data processing that address management section 215 (district distributes part 206 and address translation part 208) carries out.
If Memory Controller 220 receives the write command from access device 200, CPU203 is sent to address management section 215 with this control.Logical block sequence number LBN (S) in district's distribution part 206 reference area allocation tables, 207 definite segmentation S in the address management section 215 and the segmentation corresponding with the logical address of access device 200 appointments.More particularly, the district distributes part 206 to handle according to process flow diagram shown in Figure 8.
At first, the logic sector sequence number LSN (S11) that the district distributes part 206 to receive from access device 200 is based on the logic sector sequence number LSN that receives, according to equation (9) computational logic piece sequence number LBN (S12).In equation (7), "〉〉 " be to indicate the operational symbol of skew to the right.Logic sector sequence number LSN is offset 5 permissions to the right and determines logical block sequence number LBN according to bit format shown in Figure 7.
LBN＝LSN>>5 (9)
Next, according to equation (10) and (11), fragment sequence number S and logical block sequence number LBN (S) from logical block sequence number LBN calculating segmentation.In equation (10), " int () " is the operational symbol of round numbers.In addition, in equation (11), " % " is the operational symbol of getting remainder.
S＝int(LBN/3968) (10)
LBN(S)＝LBN％3968 (11)
By coming with reference to getting allocation table 207, can determine the physical block start sequence number PBsn (S) of corresponding segments and the total PBtn of physical block (S) (S14) according to the fragment sequence number S that determines from equation (10).At last, the fragment sequence number S in this segmentation, logical block sequence number LBN (S), and physical block start sequence number PBsn (S) and physical block sum PBtn (S) is sent to address translation part 208, and finish this process.
After this, address translation part 208 is according to the definite physical address to its overwriting data of process flow diagram shown in Figure 9.
At first, address translation part 208 distributes part 206 to receive fragment sequence number S from the district, logical block sequence number LBN (S), and physical block start sequence number PBsn (S) and physical block sum PBtn (S) are (S21).Address translation part 208 reads address administration table from the zone of the nonvolatile memory corresponding with fragment sequence number S 230, and generates physical areas admin table 209 and logical address translation table 210 (S22) from the address administration table that reads.
Then, the bit of the position of PBN (S) in the physical areas admin table 209 is changed into " effectively " (S24), " PBN (S) " write the position (S25) of LBN in the logical address translation table 210 (S).
After this, in process, determine to write destination physical block sequence number PBN (S26) according to equation (12) with data write non-volatile memory 230.Then, determine based on this sector according to equation (13), i.e. the physical address of physical sector sequence number PSN (S27).In equation (13), " | " be presentation logic and operational symbol, the bit-order of bit 0 to 4 among the logic sector sequence number LSN in " LSN[4:0] " presentation graphs 7.
PBN＝PBsn(S)+PBN(S) (12)
PSN＝(PBN<<5)|LSN[4:0] (13)
After wiping the data that write in the physical block of destination, the data that transmit from access device 200 are write the page or leaf 0 wiped the physical block in order to page or leaf 31 (S28).The data that are written into can be FAT.
1.3 conclusion
As mentioned above, in the present embodiment, address management section 25 is so that the size equalization of ranges of logical addresses and the distribution of being determined ranges of logical addresses and segmentation by the size of the segmentation 0 of overwriting data more continually than other segmentation 1 to 15 big mode is set.Allow segmentation 0 to comprise the physical block of bigger quantity like this, thereby make the frequency equilibrium of the frequency of each piece overwriting data in segmentation 0 and each piece overwriting data in other segmentation than segmentation 1 to 15.Can make like this to the frequent degree of each segmentation overwriting data consistent, thereby prolong life-span of nonvolatile memory 230.In addition, nonvolatile memory 230 is divided into a plurality of segmentations, and address administration is carried out in each segmentation, can reduce the scale of address administration table.Can cause the reduction of non-volatile memory device cost so again.
Second embodiment
Be the configuration of non-volatile memory device according to the difference of the non-volatile systems of present embodiment and first embodiment.The configuration of other parts with the operation with first embodiment in identical.Only describe below in the present embodiment with first embodiment in different configuration and operations.
In non-volatile memory device according to present embodiment, so that comprising the mode that the quantity of logical block is lacked than the logical block quantity that comprises in other ranges of logical addresses, the logical address area corresponding with the segmentation that is rewritten more continually determine that the district distributes, so that each segmentation reaches and rewrites the speed that guarantees number of times in the average range of physical addresses, with life-saving.
2.1 system configuration
Figure 10 is the synoptic diagram of expression according to the configuration of the Nonvolatile memory system of second embodiment of the invention.
Non-volatile memory device 240b with have basic similarly configuration according to the non-volatile memory device 240 of first embodiment, be to distinguish the configuration that distributes part 206b and address translation part 208b with the difference of first embodiment.
Figure 11 is the memory map of expression according to the logical address space and the corresponding relation between the physical address space of present embodiment.Logical space is divided into 16 scopes, and promptly ranges of logical addresses 0 to 15.Physical space is divided into 16 segmentations, i.e. segmentation 0 to 15.Be one to one between ranges of logical addresses and the segmentation.Each segmentation comprises a plurality of physical blocks, and each independent physical block has the size of 16k byte.In same width of cloth figure, the total quantity of logical block among LBtn (S) the indication ranges of logical addresses S.In addition, the start sequence number of logical block among LBsn (S) the indication ranges of logical addresses S.S is that scope is 0 to 15 integer.
As shown in figure 11, in the present embodiment, the size of the ranges of logical addresses (ranges of logical addresses 0) corresponding with the quilt segmentation of more frequent rewriting is 51,453, and 125M byte, the size of other ranges of logical addresses are 62,703, the 125M byte.As mentioned above, littler to be provided with than the size of other ranges of logical addresses by the size of the ranges of logical addresses of the segmentation correspondence of more frequent rewriting, make the mode of uniform size of each segmentation come regulatory region to distribute.As mentioned above, make this segmentation with by the ratio of the size of the ranges of logical addresses of the segmentation of more frequent rewriting with different, so that on average each segmentation reaches and rewrites the speed that guarantees number of times, with life-saving with the ratio of the size of the ranges of logical addresses of other segmentation.
Figure 12 is the synoptic diagram of expression according to the physical areas admin table 209b of second embodiment.In Figure 12, the physical block sequence number PBN (S) in every address of physical areas admin table 209b and the nonvolatile memory 230 in the segmentation is corresponding.Storage " effectively ", engineering noise, " bad " etc. are as the state (bulk state) of each physical block.That describes in the value of the status indication of indicator dog state and first embodiment has an identical meanings.
Figure 13 is the synoptic diagram of expression according to the logical address translation table 210b of second embodiment.In Figure 13, address every among the logical address translation table 210b is corresponding to the logical block sequence number LBN (S) in the segmentation.Position in the address stores and the physical block sequence number PBN (S) with logical block corresponding physical piece of logical block sequence number LBN (S).
Figure 14 is the Storage Mapping figure according to the district allocation table 207b of present embodiment.Address every among the district allocation table 207b is corresponding with fragment sequence number S, in these addresses, stores logical block start sequence number LBsn (S) and the logical block sum LBtn (S) of segmentation S.Logical block start sequence number LBsn (S) is corresponding to the start address of the ranges of logical addresses corresponding with segmentation S, and logical block sum LBtn (S) indicates the sum of the logical block that comprises in the ranges of logical addresses corresponding with this segmentation S.
Corresponding relation between logic sector sequence number LSN (logical sector address) and the physical sector sequence number PSN (physical sector address) with describe according to first embodiment shown in Figure 7 identical.
2.2 operation
According to the class of operation of the basic operation of the Nonvolatile memory system of present embodiment and first embodiment seemingly.
2.2.1 consider the frequent degree of rewriting
Consider the frequent degree of rewriting in the present embodiment now.Use with at the identical precondition of describing in first embodiment that writes.
In non-volatile memory device 240b according to present embodiment, as shown in figure 11, the size that each segmentation is set is equal to each other, be provided with by the size of the corresponding ranges of logical addresses 0 of the segmentation 0 of more frequent rewriting slight greatly than other ranges of logical addresses 1 to 15.
The framework of the incidence of bad piece and Memory Controller in the basis nonvolatile memory 230 of ranges of logical addresses and changing in the present embodiment, determines that each ranges of logical addresses is as follows.The key concept of determining is as far as possible little based on the size of the ranges of logical addresses 1 to 15 of setting except that ranges of logical addresses 0, so that the size of ranges of logical addresses 0 is provided with lessly.
More particularly, in the present embodiment, at first, determine the quantity of ranges of logical addresses 1 to 15 logical block in each according to equation (14).In equation (14), coefficient 0.02 is corresponding to the coefficient of bad piece incidence in the nonvolatile memory 230 (for example, 2%), as " 1 " of second of the left-hand side single physical piece corresponding to the memory address admin table.
Next, determine the quantity of logical block in the ranges of logical addresses 0 according to equation (15).
63488-(4013 * 15 segmentations)=3293 (15)
In this case, " 63488 " are the sums of logical block in the nonvolatile memory 230.In the present embodiment, simplify in order to make explanation, description does not directly relate to the zone such as system region of the present invention.By determining the scope of ranges of logical addresses 0, the size of ranges of logical addresses 0 can be arranged to the size of maximum possible.
Therefore, according to following equation, the frequency that each physical block in segmentation 1 to 15 rewrites is 0.98.
According to following equation, the frequency that the physical block in segmentation 0 rewrites is 1.05.
Aforementioned calculation result shows, according to present embodiment, compared with prior art, has obviously reduced the rewrite frequencies at segmentation 0, in addition, compared with prior art, has reduced the difference in the rewrite frequencies between segmentation 0 and other segmentation 1 to 15.Therefore, in the present embodiment, can balanced rewrite frequencies, thus life-span of nonvolatile memory 230 prolonged.
Determine the logical boundary of each segmentation from equation (14) and (15), distribute storage in the non-volatile ram among the part 206b to be used for determining the information on this border in the district, as district allocation table 207b as shown in Figure 14.District allocation table 207b can be stored in any physical block in the nonvolatile memory 230, when initialization, it can be read among the RAM.Can in the regional area of district distribution part 206b or RAM204, provide RAM.
2.2.2 the processing of address management section
Describe below at access device 200 and produce under the situation of the order that rewrites a cluster data processing that address management section 215b (district distributes part 206b and address translation part 208b) carries out.
If Memory Controller 220b receives the write command from access device 200, CPU203 is sent to address management section 215b with this control.District among the address management section 215b distributes part 206b reference area allocation table 207b, determine segmentation S and with by the logical block sequence number LBN (S) in the corresponding segmentation of the logical address of access device 200 appointments.More particularly, the district distributes part 206b to handle according to process flow diagram shown in Figure 15.
In Figure 15, the district distributes the logic sector sequence number LSN (S41) of part 206b reception from access device 200, based on the logic sector sequence number LSN that receives, according to equation (18) computational logic piece sequence number LBN (S42).By equation (18), logic sector sequence number LSN is offset 5 permissions to the right and determines logical block sequence number LBN according to bit format shown in Figure 7.
LBN＝LSN>>5 (18)
Next, calculate fragment sequence number S in the segmentation and logical block sequence number LBN (S) (S43) according to logical block sequence number LBN.In addition, the minimum value that satisfies the S of equation (19) is a number of fragments, determines logical block sequence number LBN (S) according to equation (20).
LBN-LBsn(S)<LBtn(S) (19)
LBN(S)＝LBN-LBsn(S) (20)
At last, fragment sequence number S and logical block sequence number LBN (S) are sent to address translation part 208 (S44), and finish this processing.
After this, determine according to process flow diagram shown in Figure 16 will be to the physical address of its overwriting data for address translation part 208b.
In Figure 16, at first, the logical block sequence number LBN (S) of address translation part 208b from district's distribution part 206b reception fragment sequence number S and segmentation S (S51).Address translation part 208b reads address administration table from the zone of the nonvolatile memory corresponding with fragment sequence number S 230, and generates physical areas admin table 209b and logical address translation table 210b (S52) from the address administration table that reads.
Address translation part 208b is the search invalid piece in physical areas admin table 209b, and definite PBN (S) is as writing the destination.In this case, the hunting zone from 0 to 4095.Then, address translation part 208b changes into " effectively " to the bit of the position of physical block sequence number PBN (S) among the physical areas admin table 209b (S54), and physical block sequence number " PBN (S) " is write the position (S55) of logical block sequence number LBN (S) among the logical address translation table 210b.
After this, in the process with data write non-volatile memory 230, address translation part 208b determines to write destination physical block sequence number PBN (S56) according to equation (21), then, determine based on this sector according to equation (22), i.e. the physical address of physical sector sequence number PSN (S57).
PBN＝4096×S+PBN(S) (21)
PSN＝(PBN<<5)|LSN[4:0] (22)
After wiping the data that write in the physical block of destination, the data that transmit from access device 200 are write page or leaf 0 physical block of wiping in order to page or leaf 31 (S58).The data that are written into can be FAT.
2.3 conclusion
As mentioned above, in the present embodiment, address management section 215 is so that ranges of logical addresses big or small identical and size that the ranges of logical addresses 0 that is rewritten more continually is set are determined the distribution of ranges of logical addresses and segmentation than other ranges of logical addresses 1 to 15 little mode.Can reduce the quantity that writes the logical address of data to the segmentation 0 corresponding like this, reduce frequency, thereby balanced frequency to each segmentation overwriting data prolongs life-span of nonvolatile memory 230 to segmentation 0 overwriting data with ranges of logical addresses 0.In addition, nonvolatile memory 230 is divided into a plurality of segmentations, and address administration is carried out in each segmentation, can reduce the scale of address administration table.
In other words, according to first and second embodiments, determine the distribution of ranges of logical addresses and segmentation, make the ratio of this segmentation and the size of the ranges of logical addresses of the ranges of logical addresses of being carried out data rewrite more continually with different with the ratio of the size of the ranges of logical addresses of other ranges of logical addresses, like this can balanced frequency to each segmentation overwriting data, thus life-span of non-volatile memory device prolonged.
In addition, according to first and second embodiments, so that in logical space and the physical space any one is divided into equal fixed size, and another mode that is divided into variable-size is divided logical space and physical space, so that prolong the life-span of non-volatile memory device.Yet,, still can correctly determine area size, so that identical effect is provided even two spatial division are become variable size.
In addition, if except that ranges of logical addresses 0, also have certain ranges of logical addresses that is rewritten more continually, ratio and other ranges of logical addresses of this segmentation and the size of the ranges of logical addresses of described certain ranges of logical addresses can be set, and the ratio difference of the size of ranges of logical addresses 0.
In addition, if the bad piece incidence in certain segmentation is than the bad piece incidence height of other segmentation, there are differences between the quantity of spendable physical block, the situation of overwriting data is similar more continually with above-mentioned quilt, may cause having only described certain segmentation early to reach the problem that can rewrite the life-span.The method identical with second embodiment can be proposed like this.In other words, the size that the ranges of logical addresses corresponding with the higher segmentation of bad piece incidence can be set is slighter greatly than other ranges of logical addresses, to regulate the frequency to each segmentation overwriting data.So on average each segmentation reaches and rewrites the speed that guarantees number of times, prolongs the life-span of non-volatile memory device thus.
Though described the present invention at specific implementations of the present invention, various changes are revised with other use apparent to those skilled in the art.Therefore, the invention is not restricted to this specific announcement, but be defined by the following claims.In addition, the application relates to Japanese patent application No.2005-219958 (submission on July 29th, 2005) and Japanese patent application No.2005-331060 (submission on November 6th, 2005), and the content that is incorporated herein this patented claim as a reference.
Industrial applicibility
Can prolong employing nonvolatile memory (flash memory according to non-volatile memory device of the present invention Device) etc. the life-span of storage card etc., and can be applied to for such as personal computer rest image The portable AV device of data recording/reproducing device and moving picture recording/transcriber and so on, and all The recording medium that uses such as the portable communication appts of portable phone and so on.
Claims (8)
1. the order and the logical address that provide according to from the external access device is provided for Memory Controller, to write and reading of data from nonvolatile memory, described Memory Controller comprises:
The read/write controller, be used for control from read and write data to described nonvolatile memory; With
Address management section, be used for whole logical address space is divided into a plurality of ranges of logical addresses, each ranges of logical addresses is carried out address administration, the memory block of described nonvolatile memory physically is divided into a plurality of physical areas, makes described ranges of logical addresses and described physical areas manage described ranges of logical addresses and described physical areas explicitly;
Wherein said address management section comprises: the district distributes part, be used for determining the distribution of described ranges of logical addresses and described physical areas, make that the ranges of logical addresses size of at least one ranges of logical addresses is different with the ratio of its corresponding physical district size with the ranges of logical addresses size of other ranges of logical addresses with the ratio of its corresponding physical district size
Described district distribute part so that the big or small identical mode of each ranges of logical addresses distribute described ranges of logical addresses and so that the mode that varies in size of the size of at least one physical areas and other physical areas distribute described physical areas and
It is bigger than the size of other physical areas that described district distributes part to be provided with the size in the ranges of logical addresses corresponding physical district that stores the data that rewritten more continually.
2. Memory Controller according to claim 1, wherein the data that rewritten more continually are the management information that is used for management document.
3. Memory Controller according to claim 2, wherein said management information is file allocation table.
4. non-volatile memory device comprises:
Nonvolatile memory; With
Memory Controller according to claim 1, be used for to write and reading of data from described nonvolatile memory.
5. Nonvolatile memory system comprises:
Non-volatile memory device according to claim 4; With
Access device is used for by specifying logical address wherein to come the access non-volatile memory device.
6. address management method that is used for nonvolatile memory, described nonvolatile memory comprises a plurality of physical blocks, and be used for according to the order and the logical address that provide from access device, to write and reading of data from described nonvolatile memory, described method comprises step:
Whole logical address space is divided into a plurality of ranges of logical addresses, each ranges of logical addresses is carried out address administration;
The memory block of described nonvolatile memory physically is divided into a plurality of physical areas, makes described ranges of logical addresses and described physical areas manage described ranges of logical addresses and described physical areas explicitly;
Determine the distribution of described ranges of logical addresses and described physical areas, make that the ranges of logical addresses size of at least one ranges of logical addresses is different with the ratio of its corresponding physical district size with the ranges of logical addresses size of other ranges of logical addresses with the ratio of its corresponding physical district size
So that the big or small identical mode of each ranges of logical addresses distribute described ranges of logical addresses and so that the mode that varies in size of the size of at least one physical areas and other physical areas distribute described physical areas and
Setting is bigger than the size of other physical areas with the size in the ranges of logical addresses corresponding physical district that stores the data that rewritten more continually.
7. address management method according to claim 6, wherein the data that rewritten more continually are the management information that is used for management document.
8. address management method according to claim 7, wherein said management information is file allocation table.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005219958 | 2005-07-29 | ||
| JP219958/2005 | 2005-07-29 | ||
| JP331060/2005 | 2005-11-16 |
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| CN100533409C true CN100533409C (en) | 2009-08-26 |
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| CN101625660B (en) * | 2009-08-04 | 2013-12-18 | 威盛电子股份有限公司 | Data storage device and data storage method |
| CN101639692B (en) * | 2009-08-31 | 2011-11-16 | 杭州华三通信技术有限公司 | Method, equipment and system for controlling a plurality of programmable logical components |
| US9218881B2 (en) * | 2012-10-23 | 2015-12-22 | Sandisk Technologies Inc. | Flash memory blocks with extended data retention |
| US10489064B2 (en) * | 2016-10-03 | 2019-11-26 | Cypress Semiconductor Corporation | Systems, methods, and devices for user configurable wear leveling of non-volatile memory |
| US10565115B2 (en) | 2017-03-30 | 2020-02-18 | Western Digital Technologies, Inc. | Calculating the optimal number of LBNS to prefetch per CPU |
| KR102698994B1 (en) * | 2018-12-03 | 2024-08-27 | 에스케이하이닉스 주식회사 | Storage device and operating method thereof |
| EP3792800A1 (en) * | 2019-09-12 | 2021-03-17 | Nxp B.V. | Managing equally sized virtual memory regions and physical memory regions in an electronic device |
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