TWI448891B - Data storage device and flash memory control method - Google Patents

Description

Data storage device and flash memory control method

The invention relates to a data storage device and a flash memory control method.

Today's data storage devices often use flash memory (eg, non-flash memory/NAND flash) as the storage medium.

With the development of process technology, the capacity of flash memory has increased significantly; the management information of data storage space - for example, the logical-physical address mapping table - is also becoming larger and more difficult to manage.

In addition, in addition to the logical-physical address mapping table, there may be other forms of maintenance on the flash memory, the accuracy of which depends on whether the data storage device can operate normally.

The invention discloses a data storage device and a flash memory control method.

A data storage device implemented in accordance with an embodiment includes a flash memory and a controller. The flash memory provides a data storage space, a valid page count table, a logical-physical address mapping, and an invalid block identification table. The controller configures the data storage space to store the data indicated by the host end, and establishes in the flash memory, and maintains the valid page count table, the logical-physical address mapping, and the invalid block identification table, According to the management of the data storage space. The controller is correcting the valid page count The logical-physical address mapping is updated after the table. In addition, the controller establishes the invalid block identification table according to the valid page count table.

Another embodiment discloses a flash memory control method, including the steps of: configuring a data storage space of a flash memory to store data indicated by the host; establishing and maintaining an effective memory in the flash memory; a page count table, a logical-physical address mapping, and an invalid block labeling table, wherein the updating of the logical-physical address mapping is arranged after the valid page count table is corrected, and the invalid block marking table is valid according to the The page count table is established; and the data storage space is managed according to the valid page count table, the logical-physical address map, and the invalid block label table.

The above described objects, features, and advantages of the invention will be apparent from the description and appended claims appended claims

FIG. 1 illustrates a data storage device 100 that can be manipulated by host terminal 102.

The data storage device 100 includes a flash memory (eg, NAND flash NAND Flash) 104, a controller 106, and a random access memory 108. The flash memory 104 provides a data storage space 110, a valid page count table ValidPageCnt, a logical-physical address mapping H2F, an invalid block flag table InvalidBLKRecord, an event record EventRecord, and a re-use table information SafeLink. The controller 106 executes a firmware (provided by the read-only memory in the controller 106), and is configured to configure the data storage space 110 to store the data indicated by the host 102, and is established and maintained in the flash memory 104. The above valid page count The table ValidPageCnt, the above-described logical-physical address mapping H2F, the invalid block flag table InvalidBLKRecord, the event record EventRecord, and the re-use table information SafeLink are used to manage the data storage space 110. In addition, under the control of the controller 106 executing the firmware, the random access memory 108 can record a physical-logical address mapping table F2H for the reference use of the logical-physical address mapping H2F, and more Record a table dynamic state RunTimeLink and a table temporary backup SafeLinkRam. The table dynamic state RunTimeLink records the valid page count table ValidPageCnt, the logical-physical address map H2F, and the invalid block flag table InvalidBLKRecord (or records the dependent status of the tables). The contents of the table dynamic state RunTimeLink can be copied to the table temporary backup SafeLinkRam every time the valid page count table ValidPageCnt, logical-physical address mapping H2F, and invalid block flag table InvalidBLKRecord are updated. The re-use form information SafeLink can be copied from the form to temporarily store SafeLinkRam. The event record EventRecord records the memory configuration behavior that occurs after the above backup action to record the information that the SafeLink form information SafeLink has not backed up.

The logical-physical address mapping H2F provides a group index GroupIndex and a complex array logical-physical address mapping table Group1_H2F, Group2_H2F...GroupN_H2F according to the group division.

Each unit in the group index GroupIndex corresponds to a group, and points to a logical-physical address mapping table of the corresponding group. As shown in the figure, the first unit of the group index GroupIndex corresponds to a first group, and points to a logical-physical address mapping table Group1_H2F; the second unit of the group index GroupIndex corresponds to a second group, which points to a logical-physical address mapping. Table Group2_H2F; same The rule N, the Nth unit of the group index GroupIndex corresponds to an Nth group, and points to the logical-physical address mapping table GroupN_H2F.

The logical-physical address mapping table Group1_H2F, Group2_H2F...GroupN_H2F is a grouping indicating the mapping of the host-side address (from the host-side 102) to the data storage space 110. For example, the logical-physical address mapping table Group1_H2F indicates the mapping of the host-side address of the first group (for example, the host-end address of the first range) to the data storage space 110; the logical-physical address mapping table Group2_H2F Marking the mapping of the host-side address of the second group (for example, the host-side address of the second range) to the data storage space 110; similarly, the logical-physical address mapping table GroupN_H2F indicates the host side of the N-th group The mapping of the address (eg, the host side address of the Nth range) to the data storage space 110.

Figure 2A illustrates the structure of a flash memory. The flash memory 200 includes a plurality of blocks BLK1, BLK2, ... BLKK. Each block includes a plurality of pages - for example, block BLK1 includes pages P1, P2, ... PM. FIG. 2B illustrates the correspondence between the host page Hpage defined by the host side and the physical page of the flash memory (ie, the "page" defined in FIG. 2A) PhysicalPage. The size of the host page Hpage and the physical page PhysicalPage can be equal (for example, the same 16KB). A host page Hpage needs to be configured with a physical page PhysicalPage.

Based on the 2A and 2B technologies, each unit of the complex array logical-physical address mapping table Group1_H2F, Group2_H2F...GroupN_H2F shown in FIG. 1 may correspond to a host page, and may be labeled with a block label and a page label. Which one of the blocks in the data storage space 110 is stored in the corresponding host page. Group index GroupIndex The bit may also include a block label and a page label indicating which page of the block the logical-physical address mapping table of the group corresponding to the unit is stored in. In addition, the physical-logical address mapping table F2H in the random access memory 108 can be used to instantly update the mapping of a flash memory page to a host page - indicating which "host page" the "physical page" maps to.

Based on the definitions of FIG. 2A and FIG. 2B, FIG. 3 illustrates a group index and an operation mode of a complex array logical-physical address mapping table divided according to groups.

As shown in the figure, the host page Hpage1 defined on the host side is stored in the flash memory block NF_BLK_1, page PageA, and the host page Hpage2 is stored in the flash memory block NF_BLK_2, page PageB, and the host page Hpage3. It is stored in the flash memory block NF_BLK_3, page PageC. In the embodiment, the host pages Hpage1, Hpage2 and Hpage3 are classified into a first group, and the page PageD of the configuration block NF_BLK_4 stores a logical-physical address mapping table Group1, wherein: the first unit points to the block NF_BLK_1, Page PageA indicates the data storage space of the host page Hpage1; the second unit points to the block NF_BLK_2, page PageB to indicate the data storage space of the host page Hpage2; the third unit points to the block NF_BLK_3, page PageC to indicate the data storage of the host page Hpage3 space.

In addition, the page PageE of the embodiment configuration block NF_BLK_5 stores a group index GroupIndex. As shown in the figure, the first unit of the group index GroupIndex corresponds to the first group, and points to the block NF_BLK_4 and the page PageD, indicating the logical-physical address mapping table Group1. As for the group index, other units of the GroupIndex can correspond to other Group. For example, the second unit of the group index GroupIndex corresponds to a second group, pointing to the block NF_BLK_6, page PageF, indicating a logical-physical address mapping table Group2; the logical-physical address mapping table Group2 provides a plurality of indicators, pointing The data storage location of the plurality of host pages of the second group (including, pointing to the block NF_BLK_8, page PageH and PageI, respectively, to indicate the data storage spaces of the host pages Hpage4 and Hpage5, and pointing to the block NF_BLK_9, page PageJ, Indicate the data storage space of the host page Hpage6). The third unit of the group index GroupIndex corresponds to a third group, pointing to the block NF_BLK_7, page PageG, indicating a logical-physical address mapping table Group3; the logical-physical address mapping table Group3 provides a plurality of indicators, pointing to the third The data storage location of the plurality of host pages of the group (including, pointing to the block NF_BLK_10, page PageK, PageL, and PageM, respectively, to indicate the data storage spaces of the host pages Hpage7, Hpage8, and Hpage9). Specifically, according to the management rule, the host page data of the same group may be distributed in multiple blocks (such as three host pages Hpage1, Hpage2, Hpage3 data dispersed in three blocks NF_BLK_1, NF_BLK_2 and NF_BLK_3, Or three host pages Hpage4, Hpage5 and Hpage5 data stored by two blocks NF_BLK_8 and NF_BLK_9, or the host page data of the same group can be concentrated in a single block (such as three concentrated in a single block NF_BLK_10) Host page Hpage7, Hpage8, Hpage9 data).

Referring to the embodiment shown in FIG. 3, if the host side instructs to read the host page Hpage1, the controller of the data storage device can analyze the host page Hpage1, and learn that the host page Hpage belongs to a first group. The controller can query the group index GroupIndex to find out the unit corresponding to the first group, according to the The middle indicator finds the logical-physical address mapping table Group1. The controller can learn that the host page Hpage1 data is stored in the page PageA of the block NF_BLK_1 according to the unit of the corresponding host page Hpage1 in the logical-physical address mapping table Group1. In this way, the read operation of the host page Hpage1 can be realized. The technology establishes a mapping relationship between logical addresses and physical addresses by using indicators of more than two levels.

The logical-physical address mapping H2F technology described is advantageous for managing large-capacity flash memory. Figure 4 illustrates the correction technique for this logical-physical address mapping H2F.

Referring to FIG. 4, the previous data Hpage_Old of a target host page is stored in an original page Page1, which is indicated by an indicator provided by a unit of the logical-physical address mapping table Group_Old. The logical-physical address mapping table Group_Old is indicated by an indicator provided by a unit in the group index GoupIndexOld.

Regarding the data update of the target host page, the technical new configuration update page Page2 stores the updated material HPage_New of the target host page, and the original page Page1 is marked as invalid. In addition, the technology newly configures a logical-physical address mapping table update page Group_New, and stores the modified logical-physical address mapping table (again labeled Group_New). The indicator provided by one unit of the logical-physical address mapping table Group_New points to the update page Page2, and the logical-physical address mapping table Group_Old is marked as invalid. In addition, the technology newly configures a group index update page GroupIndexNew, and stores the updated group index (again labeled GroupIndexNew). Group index GroupIndexNew One of the indicators provided by the unit points to the logical-physical address mapping table Group_New, group The group index GroupIndexOld is then marked as invalid. In summary, the logical-physical address mapping H2F can implement the target host page to the physical page by newly configuring two pages of space (filling in the corrected group index GroupIndexNew and the logical-physical address mapping table Group_New). Map correction, the program is quite simple, suitable for large-capacity flash memory.

In an embodiment, after the update page Page 2 is configured to the target host page, the mapping relationship may be first recorded in the physical-logical address mapping table F2H of the random access memory (the first icon number 108) for filling in. The data is used when referring to the HPage_New to the flash memory. In addition, it can also be used when establishing the logical-physical address mapping H2F.

In one embodiment, the technology copies the data HPage_Old of the original page Page1 previously mapped by the target host page to the random access memory 108 for data update, and then stores the data according to the physical-logical address mapping table F2H. To the update page Page2. The logical-physical address mapping table Group_Old may also be copied to the random access memory 108 for data update, and then stored to the flash memory as Group_New. The group index GroupIndexOld may also be copied to the random access memory 108 for data update, and then stored to the flash memory as GroupIndexNew.

Figure 5 illustrates the data update process of a target host page in a flow chart. In step S502, an update page (corresponding to the update page Page 2 of FIG. 4) is configured in the flash memory to update the data of a target host page. Step S504 corrects the physical-logical address mapping table F2H stored in the random access memory (corresponding to the reference numeral 108 of FIG. 1) to record the updated page Page2 to map the target host page. Step S506: copying the data HPage_Old of an original page (corresponding to the original page Page1 of FIG. 4) previously mapped by the target host page to the random The access memory 108 is updated to the material HPage_New, and then stored to the update page Page2 according to the physical-logical address mapping table F2H. Step S508, in the flash memory, configure a logical-physical address mapping table update page (corresponding to Group_New of FIG. 4) for the group to which the target host page belongs, with one unit pointing to the update page Page2. Step S510 configures a group index update page (corresponding to GroupIndexNew of FIG. 4) in the flash memory, and one of the units points to the logical-physical address mapping table update page Group_New.

Step S508 may include copying the old logical-physical address mapping table (corresponding to FIG. 4 Group_Old) to the random access memory 108 for data update, and then storing the data to the logical-physical address mapping table update page Group_New. Step S510 may include copying the old group index GroupIndexOld to the random access memory 108 for data update, and then storing the data to the group index update page GroupIndexNew.

The above maintenance about the logical-physical address mapping table H2F can be performed in a firmware manner, and is implemented by the controller 106.

The establishment and maintenance of other forms and records (as shown in Figure 1, ValidPageCnt, InvalidBLKRecord, EventRecord, or SafeLink) are discussed below. In the following discussion, the logical-physical address mapping H2F does not limit the multi-level form described above. Anyone who can mark a logical-physical mapping relationship can be used to implement a logical-physical address mapping H2F. The valid page count table ValidPageCnt is the number of valid pages for each block. The invalid block flag table InvalidBLKRecord can be obtained based on the valid page count table ValidPageCnt, and the block with the valid page number of 0 can be marked as an invalid block.

Figure 6 illustrates a table maintenance procedure in a flow chart. Step S602 monitors whether a flash memory satisfies a table update condition. One embodiment is to determine that the flash memory satisfies the table update condition when the block is filled (no more idle pages); or the table update condition can be set to other forms. The memory configuration that occurs during the monitoring process can be recorded in the event record EventRecord. If the table update condition is satisfied, the flow proceeds to step S604, and the EventRecord is mapped to the logical-physical address mapping H2F based on the event to update the valid page count table ValidPageCnt. After the valid page count table ValidPageCnt is updated, the process proceeds to step S606 to update the logical-physical address mapping H2F. This step can also record the content of the EventRecord based on the event. The update of the invalid block flag table InvalidBLKRecord is also designed after the valid page count table ValidPageCnt is updated - executed by step S608. In step S610, the updated valid page count table ValidPageCnt, logical-physical address mapping H2F, and invalid block identification table InvalidBLKRecord are backed up in the flash memory 104 to be used as the re-use table information SafeLink (available randomly) Access table memory dynamic state RunTimeLink and table temporary backup SafeLinkRam design). In this way, each round of the table update has the backup form information SafeLink for backup, and the memory configuration that occurs until the next backup is recorded by the event record EventRecord. The management information of the data storage space 110 is not lost at any point in time when an unexpected interruption (e.g., power outage) occurs.

Figure 7 illustrates a re-powering process. Step S702: initially updating the valid page count table ValidPageCnt, logical-physical address mapping H2F, and invalid block label according to the content backed up by the resume information table SafeLink. Showcase InvalidBLKRecord. Step S704 is to restart the form maintenance program from step S604 of Fig. 6. As described in step S604, the event record EventRecord that is not backed up by the re-use form information SafeLink can be used to update the valid page count table ValidPageCnt in more detail than the logical-physical address mapping H2F, and the subsequent step S60 can also be performed. The logical-physical address mapping H2F is updated in more detail based on the event record EventRecord. As a result, the unintended interrupt does not destroy the maintenance of the valid page count table ValidPageCnt, the logical-physical address map H2F, and the invalid block flag table InvalidBLKRecord.

In another embodiment, the unintended interrupt is detected by the sequence number comparison method; the embodiment-alignment FIG. 6 - the step S610 may be omitted, but the update of the valid page count table ValidPageCnt is completed in step S604. The SN (configurable in the management space of the valid page count table ValidPageCnt, as shown in FIG. 1) counts the update of the valid page count table ValidPageCnt, and completes the update of the invalid block flag table InvalidBLKRecord with the sequence number SN in step S608. '(Configurable in the management space of the invalid block flag table InvalidBLKRecord, as shown in FIG. 1) Count the update of the invalid block flag table InvalidBLKRecord. Figure 8 illustrates a re-powering process. Step S802 compares the sequence numbers SN and SN'. If the serial number SN leads the serial number SN', the flow proceeds to step S804, and it is determined that the valid page count table ValidPageCnt has already been confirmed, so the table maintenance program is restarted from the update of the logical-physical address mapping H2F (the event record can be recorded based on the event). If the sequence number SN is equal to the sequence number SN', the flow proceeds to step S806, and the update of the valid page count table ValidPageCnt can be restarted (the EventRecord can be recorded based on the event to map the logical-physical address mapping H2F) Form maintenance program. This type of implementation does not require the use of SafeLink backup technology for re-use of the form information.

The programs described in the above FIGS. 6 to 8 can also be implemented by the controller 106 in a firmware manner.

In addition, although the present invention has been described above by way of a preferred embodiment, it is not intended to limit the invention, and any modifications and refinements may be made without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧ data storage device

102‧‧‧Host side

104‧‧‧Flash memory

106‧‧‧ Controller

108‧‧‧ Random access memory

110‧‧‧data storage space

200‧‧‧flash memory

BLK1, BLK2...BLKK‧‧‧ Block

EventRecord‧‧‧Event Record

F2H‧‧‧Physical-Logical Address Mapping Table

Group1...Group3, Group1_H2F...GroupN_H2F‧‧‧Logical-Physical Address Mapping Table

GroupIndex‧‧‧Group Index

GroupIndexOld‧‧‧ group index before correction

GroupIndexNew‧‧‧corrected group index/group index update page

GroupOld‧‧‧ corresponds to the group to which the target host page belongs, and is the logical-physical address mapping table before the correction.

GroupNew‧‧‧ corresponds to the group to which the target host page belongs, and is the modified logical-physical address mapping table/logical-physical address mapping table update page.

H2F‧‧‧Logical-Physical Address Mapping Table

HPage, Hpage1...Hpage9‧‧‧Host page

HPage_Old, Hpage_New‧‧‧ Target host page correction before and after data

InvalidBLKRecord‧‧‧ Invalid Block Marking Table

NF_BLK_1...NF_BLK_10‧‧‧ Block

P1, P2...PM‧‧‧ pages

Page1‧‧‧ original page

Page 2‧‧‧Update Page

PageA...PageM‧‧‧Page

PhysicalPage‧‧‧Physical Page

RunTimeLink‧‧‧Table Dynamic Status

S502...S510, S602...S610, S702...S704, S802...S806‧‧‧ steps

SafeLink‧‧‧Re-use form information

SafeLinkRam‧‧‧ form temporary backup

SN, SN’‧‧‧ serial number

ValidPageCnt‧‧‧Valid Page Count Table

1 is a diagram of a data storage device 100 implemented according to an embodiment; FIG. 2A illustrates a flash memory structure; FIG. 2B illustrates a "host page" defined by a host side and a "physical page" of a flash memory. Corresponding relationship; Figure 3 illustrates a group index and the operation mode of the complex array logical-physical address mapping table according to the group; FIG. 4 illustrates the correction technique of the logical-physical address mapping H2F; 5 is a flow chart illustrating a data update process of a target host page; FIG. 6 illustrates a form maintenance program in a flowchart; FIG. 7 illustrates a power-up process; and FIG. 8 illustrates another power-up process.

S602‧‧‧ Judgment step, meet the table update conditions?

Step S604‧‧, update ValidPageCnt

Step S606‧‧‧, update H2F

Step S608‧‧, update InvalidBLKRecord

S610‧‧‧ steps to back up the forms to SafeLink

Claims (14)

A data storage device includes: a flash memory, a data storage space, a valid page count table, a logical-physical address mapping, and an invalid block labeling table; and a controller configured to configure the data storage space Storing the data indicated by the host, and establishing, maintaining the valid page count table, the logical-physical address mapping, and the invalid block identification table in the flash memory to manage the data storage space; The controller updates the logical-physical address mapping after correcting the valid page count table, and the controller establishes the invalid block identification table according to the valid page count table. The data storage device of claim 1, wherein the controller further establishes an event record in the flash memory, and records the valid page count table, the logical-physical address mapping, and the invalid block identifier. The memory configuration behavior that occurred after the last round of updates. The data storage device of claim 2, wherein the controller maps the logical-physical address based on the event record to update the valid page count table. The data storage device of claim 3, wherein the controller applies the valid page to the information of the valid page count table, the logical-physical address mapping, and the invalid block identification table after each round of updating. The counter table, the logical-physical address mapping, and the invalid block labeling table are used to generate a re-use form information in the flash memory backup, and the controller is first updated according to the re-use form information when the power is restored. Valid page count table, logical-physical address mapping, and invalid block flag table, based on the above events The record updates the valid page count table for the logical-physical address mapping and continues to maintain the valid page count table, logical-physical address mapping, and invalid block flag table. The data storage device of claim 3, wherein the controller updates the invalid block identification table after updating the logical-physical address mapping. The data storage device of claim 5, wherein the controller further updates the valid page count table by a first serial number after updating the valid page count table, and updates the invalid block identifier. The update of the invalid block identification table is counted by a second serial number, and the controller detects an unexpected interruption by comparing the first and the second serial number. The data storage device of claim 6, wherein, in the case of power-on, the controller determines that the valid page count table has been confirmed under the condition that the first serial number leads the second serial number, and then records according to the event The logical-physical address mapping is updated, and the above-mentioned valid page count table, logical-physical address mapping, and invalid block identification table are maintained. A flash memory control method includes: configuring a data storage space of a flash memory to store data indicated by a host end; establishing, in the flash memory, and maintaining a valid page count table, a logic - a physical address mapping and an invalid block identification table, the update of the logical-physical address mapping is arranged after the valid page count table is corrected, and the invalid block identification table is established according to the valid page count table; The data storage space is managed according to the valid page count table, the logical-physical address mapping, and the invalid block identification table. For example, the flash memory control method described in claim 8 further establishes an event record in the flash memory, and records the valid page count table, the logical-physical address mapping, and the invalid block identification table. The memory configuration behavior that occurs after a round of updates. The flash memory control method according to claim 9 is characterized in that the logical-physical address mapping is compared based on the event record to update the valid page count table. The flash memory control method according to claim 10, wherein the valid page count table is updated after each round of information of the valid page count table, the logical-physical address map, and the invalid block label table. The logical-physical address mapping and the invalid block marking table are backed up in the flash memory to display a form information for re-charging, and the valid page counting table and logic are first updated according to the information of the re-use form when the power is restored. a physical address mapping, and an invalid block labeling table, and updating the valid page count table based on the event-recording ratio to the logical-physical address mapping, and continuing to map the valid page count table and the logical-physical address And maintain with the invalid block labeling table. The flash memory control method according to claim 10, wherein the invalid block identification table is updated after updating the logical-physical address mapping. The flash memory control method of claim 12, after updating the valid page count table, counting the update of the valid page count table by a first serial number, and after updating the invalid block identification table The update of the invalid block identification table is counted by a second serial number, and the unintended interruption is detected by comparing the first and the second serial numbers. The flash memory controller as described in claim 13 a method, wherein if the first serial number leads the second serial number upon power-on, it is determined that the valid page count table has been confirmed, and then the logical-physical address mapping is updated according to the event record, and the valid page count table is continued , logical-physical address mapping, and invalid block identification table maintenance.