JP2005301885A - Access method to data recording medium, information processor, and access program to data storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress capacity of a conversion table from a logical address to a physical address stored in a main storage area of an information processing means as much as possible. <P>SOLUTION: In accessing each storage position of the unit data based on the translation table information from a logical address d5 corresponding to each unit data stored in a flash memory to a physical address d6 which corresponds to the storage position (block) of the unit data in the storage area of the flash memory, the translation table having a physical address d6" in which a redundant bit and a bit string of default length at lower side are omitted, is stored in the main storage area, the access is carried out to the range of a block expressed with the physical address d" in which a part to be obtained by applying the specified logical address to the translation table is omitted, logical addresses stored in a flash memory corresponding to respective blocks are acquired, and the access is carried out to the block where the acquired above logical address matches the specified logical address. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  Each storage position of the unit data based on conversion table information from a logical address corresponding to each unit data stored in the data storage medium to a physical address corresponding to the storage position of the unit data in the storage area of the data storage medium The present invention relates to an access method for accessing a data storage medium, an information processing apparatus embodying the method, and an access program for the data storage medium.

In recent years, non-volatile data storage media such as flash memory, which can electrically erase and write stored data and retain data storage without external power supply, have been used for audio playback / recording devices, video cameras, A device that is mounted on various devices such as a digital camera and can record (write) and read (access) various data files such as voice, image, and text has become widespread.
In a data storage medium such as a flash memory, the number of repetitions of data writing and erasing at each physical storage position has a lifetime. For this reason, every time the data is updated, the physical storage position is sequentially changed so that the writing of data to a part of the storage positions is not concentrated.
However, it is not possible to manage physical addresses, which are physical location information on a data storage medium that changes from time to time, using a higher-level program such as an application program executed by a built-in microcomputer (hereinafter referred to as a microcomputer). It is cumbersome and the processing burden is heavy. For this reason, a logical address is assigned to each unit data stored in the data storage medium, and a conversion table from logical address to physical address (hereinafter referred to as logical / physical conversion table) The data is expanded in a main storage area secured in a storage means such as a RAM. As a result, by specifying a logical address for the unit data to be accessed by a higher-order program, the logical address is applied to the logical / physical conversion table by a lower-order program such as an OS (operation system). This makes it possible to access data stored at the physical address obtained.
In recent years, the capacity of data storage media such as flash memories has increased in various devices, and the data size of the logical / physical conversion table developed in the main storage area of the information processing means tends to increase.
On the other hand, efficient use of the main storage area of information processing means such as a microcomputer is required due to demands for power saving, downsizing, and cost reduction of devices.
Conventionally, for example, Patent Document 1 discloses a technique for storing the logical / physical conversion table in a data storage medium in order to suppress the consumption capacity of the main storage area by the logical / physical conversion table.
JP 2000-47932 A

However, in the technique disclosed in Patent Document 1, since the logical / physical conversion table is stored in a data storage medium itself such as a flash memory having a relatively low access speed, the storage area of the data storage medium is consumed. There was a problem that the data access speed was slow.
Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a data storage that minimizes the capacity of a conversion table from a logical address to a physical address stored in the main storage area of the information processing means. An object is to provide a method for accessing a medium, an information processing apparatus embodying the method, and a program for accessing a data storage medium.

In order to achieve the above object, according to a first aspect of the present invention, the information processing means corresponds to the storage location of the unit data in the storage area of the data storage medium from the logical address corresponding to each unit data stored in the data storage medium. In the access method to the data storage medium for accessing each storage location of the unit data based on the conversion table information to the physical address to be converted, the conversion table information having the physical address compressed or partially omitted Based on the compressed or partly omitted physical address obtained by applying the specified logical address to the conversion table information, and the compression conversion table recording step to be stored in the main storage area of the information processing means And a first access step for accessing a storage location of the unit data on the data storage medium. Be Te is constituted as a method of accessing a data storage medium characterized.
Thereby, the capacity of the conversion table (corresponding to the logical / physical conversion table) developed in the main storage area of the information processing means such as a microcomputer can be suppressed. Further, since the conversion table is expanded in the main storage area, the access speed of the data storage medium is not restricted when referring to the conversion table.

More specifically, for example, the compression conversion table recording step stores the conversion table information having the physical address in which redundant bits in each physical address are omitted in the main storage area. One access step may access the storage location of the data storage medium corresponding to the physical address from which the redundant bit is omitted.
As a result, the capacity of the conversion table developed in the main storage area is reduced by the redundant bits.
The compression conversion table recording step stores the conversion table information having the physical address in which a bit string of a predetermined length is omitted from the lowest side in each of the physical addresses in the main storage area, The first access step corresponds to each storage position of the unit data in the data storage medium by accessing a range of storage positions of the data storage medium represented by the physical address in which the bit string is omitted. It is conceivable that the stored logical address is acquired and the unit data storage location where the specified logical address matches is accessed.
As a result, the capacity of the conversion table developed in the main storage area can be suppressed by the omitted bit string. However, in this case, the physical address from which the lower bit string is omitted points to a range of a plurality of consecutive storage positions, and it is necessary to search for a position corresponding to the specified logical address from the range. Therefore, the access speed is sacrificed accordingly. This is effective when priority is given to the suppression of the consumption capacity of the main storage area.
Of course, it goes without saying that it is more effective to omit the redundant bits at the same time.
In addition, for example, in the compression conversion table recording step, the conversion table having a plurality of post-compression physical address sets obtained by the compression by a lossless compression method for each set of one or a plurality of the physical addresses is obtained. And storing in the main storage area, wherein the first access step expands one post-compression physical address set corresponding to the designated logical address, and the physical before compression obtained by the expansion. An access to the storage location of the data storage medium corresponding to one of the addresses is also conceivable.
As a result, the capacity of the conversion table developed in the main storage area can be reduced by the amount compressed by the lossless compression method capable of complete data restoration. In addition, since only one of the plurality of post-compression physical address data sets is expanded at the time of data expansion, an increase in consumption of the main storage area at the time of data expansion can be minimized.

In the second invention, the information processing means converts a logical address corresponding to each unit data stored in the data storage medium to a physical address corresponding to the storage position of the unit data in the storage area of the data storage medium. In the method of accessing a data storage medium for accessing each storage location of the unit data based on the conversion table information, the conversion table information only for the logical address of the unit data included in the data file designated as an access target Corresponding to the physical address obtained by applying the logical address of each of the unit data included in the data file to the conversion table information. Accessing the storage location of the data storage medium And second access step, is constituted as a method of accessing a data storage medium characterized by comprising a.
As a result, since the minimum conversion table necessary for accessing the designated data file is only expanded in the main storage area, the consumption capacity of the main storage area can be suppressed.

  Further, the present invention relates to an information processing apparatus provided with means for executing each step in the method for accessing and accessing the first and second data storage media, or processing corresponding to each step is performed by a computer. It may be understood as an access program to a data storage medium to be executed.

According to the first aspect, the conversion table information from the logical address corresponding to each unit data stored in the data storage medium to the physical address corresponding to the storage position of the unit data in the storage area of the data storage medium When accessing each storage position of the unit data based on the above, the conversion table information having the physical address compressed or partially omitted is stored in the main storage area, and the specified logical address is converted into the conversion address. Since the storage location of the unit data of the data storage medium is accessed based on the compressed or partially omitted physical address obtained by applying to the table information, the conversion expanded in the main storage area The capacity of the table can be reduced.
According to the second invention, the conversion table from the logical address corresponding to each unit data stored in the data storage medium to the physical address corresponding to the storage position of the unit data in the storage area of the data storage medium In accessing each storage location of the unit data based on the information, the conversion table information is stored in the main storage area only for the logical address of the unit data included in the data file designated as an access target, Access to the storage location of the data storage medium corresponding to the physical address obtained by applying the logical address of each of the unit data included in the data file to the conversion table information. The minimum conversion table required for data is displayed in the main storage area. Since only the consumption can be suppressed capacity of the main storage area.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.
FIG. 1 is a block diagram showing a schematic configuration of a recording / playback apparatus X as an example of the information processing prime minister according to the embodiment of the present invention. FIG. 2 is a diagram showing a processing hierarchy of a file system in the recording / playback apparatus X. FIG. 3 is a diagram schematically showing an example of the data structure in the storage area of the flash memory accessed by the recording / reproducing apparatus X. FIG. 4 is a diagram for explaining the correspondence between logical addresses and physical addresses. Is a schematic diagram showing an example of a logical / physical conversion table created in a conventional information processing apparatus, and FIG. 6 shows an example of a logical / physical conversion table between the conventional case and the case according to the first embodiment of the present invention. FIG. 7 is a schematic diagram showing an example of a logical / physical conversion table in the second embodiment of the present invention.

First, the configuration of a recording / reproducing apparatus X, which is an example of an information processing apparatus according to an embodiment of the present invention, will be described using the block diagram of FIG.
The recording / playback device X inputs sound into a microphone and stores it in a data storage medium as digital sound data, and also includes digital sound data, digital image data (still image), digital video stored in the data storage medium It is an apparatus having a playback function for playing back data (moving images).
As shown in FIG. 1, the recording / playback apparatus X converts a digital signal processor (DSP) 102 that performs various types of processing of an audio digital signal, a microphone 103, and an audio signal input from the microphone 103 into a digital signal. The display comprising the A / D converter 104, the speaker 105, the D / A converter 106 for converting the audio digital signal into an analog audio signal, the display driver unit 107 for controlling the display unit 108, and the liquid crystal panel. A control unit 108, a microcomputer 109 (microcomputer) that controls each device included in the recording / playback apparatus X, an operation unit 110 including operation buttons, and a memory attachment / detachment interface 120.
The memory attachment / detachment interface 120 is an interface for attaching / detaching the flash memory 1 which is a digital data storage medium to / from the recording / reproducing apparatus X. As the flash memory 1, for example, a memory element such as SmartMedia ^™ (registered trademark of Toshiba Corporation) or compact flash (registered trademark of SanDisk Corporation) is used. The flash memory 1 has a signal terminal connected to an external pin of the microcomputer 109 via the memory attachment / detachment interface 120, and data read / write (access) to the flash memory 1 is performed by the microcomputer 109.
The microcomputer 109 includes, in addition to a processor (not shown), a ROM 111 that stores a program executed by the processor, and the program is expanded when the program is executed, and is required when the program is executed. And a RAM 112 that provides a main storage area in which various data are temporarily stored.

When execution of a recording process is designated from the operation unit 110, the analog audio signal collected by the microphone 103 is converted into a digital signal by the A / D converter 104, and further, the DSP 102 It is converted into audio digital data of a predetermined format such as PCM, ADPCM, or MP3 by various encoding processes, and stored (recorded) in the flash memory 1 by the microcomputer 109.
On the other hand, when execution of audio reproduction processing is designated from the operation unit 110, a data file of designated digital audio data is read from the flash memory 1 by the microcomputer 109, and this is decoded by the DSP 102. Is converted into digital time-series audio data, further converted into an analog audio signal by the D / A converter 106 and output from the speaker 105 as audio.
In addition, when execution of a still image, moving image, or text (character string) playback process is designated from the operation unit 110, designated digital image (or video, text) data is sent from the microcomputer 109 to the microcomputer 109. The image (or video, text) is read from the flash memory 1 and displayed on the display unit 108 via the display driver 107.
The configuration of the recording / playback apparatus X shown in FIG. 1 is just an example of the information processing apparatus according to the embodiment of the present invention.

FIG. 2 shows a processing hierarchy of a file system for accessing a data file (digital audio data, digital image data, digital video data, text data, etc.) stored in the flash memory 1 in the microcomputer 109.
As shown in FIG. 2, the file system (data access program) for data access to the flash memory 1 executed by the microcomputer 109 has a hierarchical structure, and the flash memory access layers P1, It has a physical address management layer P2, a logical address management layer P3, a file management processing layer P4, and an application processing layer P5.
The flash memory access layer P1 is a layer that performs processing corresponding to a physical standard and protocol related to access to the flash memory 1.
The physical address management layer P2 is a layer that performs various processes related to management of physical addresses corresponding to the storage positions of each unit data stored in the storage area of the flash memory 1 (data storage medium).
The logical address management layer P3 is a layer that performs various processes related to management of logical addresses that are identification information of unit data stored in the storage area of the flash memory 1 (data storage medium).
The file management processing layer P4 performs various processes related to the management of the data file, such as the management of the correspondence between the data file composed of the plurality of unit data and the logical address of each of the unit data included in the data file. This is a layer to be performed and corresponds to a so-called FAT (File Allocation Table) file system.
The application processing layer P5 is a layer that performs processing related to an interface with another application program.
The various application programs send and receive data and commands related to the access processing to the flash memory 1 to the application processing layer P5, thereby controlling the access processing to the flash memory 1 with detailed specifications (necessary for the flash memory 1). Can be executed without being aware of detailed processing.

FIG. 3 schematically shows an example of the data structure in the storage area of the flash memory 1 accessed by the recording / reproducing apparatus X.
The example shown in FIG. 3 is an example in which the flash memory 1 is the 32 MByte smart media (registered trademark of Toshiba Corporation). In this case, the storage area of the flash memory 1 is divided into unit storage areas called blocks d1, and this block d1 becomes a basic access unit. The physical addresses from 0 to 1023 are allocated to all the blocks d1 according to the physical arrangement order. Further, when the physical address has a storage area exceeding 1023, zone numbers (represented as ZONE 0 and ZONE 1 in the figure) for further identifying the set of the blocks d1 (physical addresses 0 to 1023) are allocated. It is. Thus, when there are a plurality of zones, the information obtained by combining the zone number and the physical address represents a substantial physical address.
Each of the blocks d1 includes 32 pages d2. Each page d2 includes a data area d3 (512 bytes) in which data is written and erased by the microcomputer 109 and a redundant area d4 (16 bytes). ). Depending on the capacity of the flash memory 1, there are 16 pages d2 and 256 bytes of data area d3.
In the redundant area d4, in addition to status information (not shown) of the block d1, a logical address d5 corresponding to data (unit data) stored in each of the data areas d3 of the block d1 to which the page d2 belongs is stored. (2 bytes) is stored. Here, although the redundant area d4 exists for each page d2, the same logical address d5 is assigned to each redundant area d4 of all the pages d2 (PAGE 0 to PAGE 31) belonging to one block d1. Stored.

As described above, in the data storage medium such as the flash memory 1, since the number of repetitions of data writing and erasing in each block d1 which is each physical storage position has a lifetime, some of the blocks d1 Each time the data is updated, the block d1 for storing the data is changed so that access to the data is not concentrated.
FIG. 4 is a diagram for explaining the correspondence between the logical address and the physical address. Here, FIG. 4A shows a state before data update in a certain storage area of the flash memory 1, and FIG. 4B shows a state after data update in the same storage area. Further, in the figure, the portion indicated as “used block” represents the block d1 in which valid data that can be accessed is stored, and the portion indicated as “unused block” stores valid data that can be accessed. It represents the block d1 that is not.
For example, in a storage area of the flash memory 1, the physical address d6 of each block d1 and the logical address d5 of the data stored in the block d1 corresponding to the physical address d6 are shown in FIG. It is assumed that there is a correspondence shown in FIG. In this state, when the data stored in the block whose physical address d5 is “105” (the data whose logical address d5 is “102”) is updated (including deletion), the updated data is the original data. Is stored in an unused block (the physical address d5 is “107”) different from the first block. At this time, the logical address d5 corresponding to the physical address d6 “107” of the block in which the updated data is stored is updated to “102” which is the logical address d5 of the data. Further, the block in which the physical address d6 is “105” in which the data before update is stored is an unused block, and the logical address d5 corresponding to the block is updated from the original “102”. The data is updated to “104” originally set in the block storing the data. That is, the logical address d5 is replaced.
By such block swap processing, the data recording / updating frequency of each block is leveled so that access to some of the blocks d1 is not concentrated. As a result, the lifetime of the flash memory 1 with a limited number of rewrites can be extended.

Further, by storing the correspondence relationship between the logical address d5 and the physical address d6 in the RAM 112 as the logical / physical conversion table, the logical address is transferred from the file management processing layer P4 side. By simply designating d5, the designated logical address d5 is applied to the logical / physical conversion table, and the data stored in the obtained physical address d6 can be accessed.
The recording / reproducing apparatus X uses the microcomputer 109 (information processing means) from the logical address d5 corresponding to each block d1 unit data (unit data) stored in the flash memory 1 (data storage medium). , Based on the logical / physical conversion table (information thereof) which is a conversion table to the physical address d6 corresponding to the block d1 (storage position of the unit data) in the storage area of the flash memory 1. Access each one.
Here, each time new data written to the block d1 is generated, the process of allocating a new logical address d5 and the process of managing the association between the logical address d5 and the physical address d6 are performed by the logical address. This is performed by the management layer P3.
Note that, for reasons such as simplification of the replacement process of the logical address d5, the swap process of the block d1 is performed within the same zone.
In the conventional information processing apparatus, after the power is turned on, the microcomputer 109 acquires the logical addresses d5 for all the blocks d1 of the flash memory 1, and the physical addresses d6 for all the logical addresses d5. The logical / physical conversion table for conversion into the main memory area in the RAM 112 has been expanded.
FIG. 5 is a schematic diagram showing an example of the logical / physical conversion table created in the conventional information processing apparatus.
As shown in FIG. 5, the logical / physical conversion table in which the physical address d6 (2 bytes) is associated with all the logical addresses d5 (2 bytes) is created in the main storage area.
The data size of such a conventional logical / physical conversion table is 4 KBytes in the flash memory 1 having a capacity of 32 MBytes and 16 KBytes in the flash memory 1 having a capacity of 128 MBytes. In a small-sized (portable) information processing apparatus in which demands for power saving, downsizing, and low cost are strict and the capacity of the RAM 112 is large, it is desired to reduce the size of the logical / physical conversion table.

<First Embodiment>
On the other hand, in the recording / reproducing apparatus X according to the embodiment of the present invention, the logical / physical conversion table, that is, each unit data stored in the flash memory 1 (data storage medium) (stored for each block d1). A conversion table (conversion table information) from the logical address d5 corresponding to the data) to the physical address d6 corresponding to the block d1 (storage position of the unit data) in the storage area of the flash memory 1. When storing in the main storage area in the RAM 112, the 2-byte physical address d6 set in the conversion table is stored in a compressed state or partially omitted (the compression conversion table recording step). Example).
Then, when the logical address d5 is specified, the microcomputer 109 applies the specified logical address d5 to the logical / physical conversion table, and the compressed or partially omitted physical Based on the address, the block d1 (unit data storage position of the data storage medium) is accessed (corresponding to the first access step).
In the following, a description will be given of each embodiment when the physical address d6 is partially omitted and when compression is performed.

<First embodiment: Example 1 in which a part of a physical address is omitted (omission of redundant bits)>
As described above, the designation of the physical address d6 is designated as 2-byte (= 16 bits) address information.
Here, the physical address d6 only needs to be uniquely numbered in each of the blocks d1. For example, in the flash memory 1 having a capacity of 128 MByte, 0 to 1023 in the flash memory 1 having a capacity of 256 MByte, 0 to 2046. It is sufficient if the numbering can be done. That is, 10 bits and 11 bits are sufficient, and 6 bits and 5 bits are redundant bits.
Therefore, in the first embodiment, the logical / physical conversion table having the physical address from which redundant bits in each of the physical addresses d6 are omitted by the processing of the physical address management layer P2 executed by the microcomputer 109 is stored in the RAM 11. In the main storage area.
FIG. 6 is a schematic diagram showing an example of a logical / physical conversion table between the conventional case and the case according to the first embodiment of the present invention. The example of FIG. 6 is an example when the capacity of the flash memory 1 is 128 MByte.
Here, FIG. 6A shows the storage contents of the physical address d6 in the conventional logical / physical conversion table, and FIG. 6B shows the storage contents of the physical address d6 from which redundant bits are omitted. Represent. FIG. 6C shows the stored contents of the logical address d6 in which some lower-order bit strings are omitted in addition to omitting redundant bits. FIG. 6C will be described later.
As shown in FIG. 6B, in this embodiment, the logical address d6 ′ from which the redundant upper 6 bits of the physical address d6 originally expressed by 2 bytes (= 16 bits) are omitted is used as the logical address d6 ′. A logical / physical conversion table is set and stored in the main storage area (an example of the compression conversion table recording step).
As a result, the storage area of the physical address d6 in the logical / physical conversion table can be reduced to about 10 KBytes while the main storage area in the RAM 112 has been consumed about 16 KBytes. Become.
When the flash memory 1 is accessed, the physical address d6 ′, which is partially omitted, is processed by the processing of the layers P1 to P3 below the logical address management layer P3 executed by the microcomputer 109. The block d1 (storage position of the data storage medium) is accessed (an example of the first access step).
More specifically, the logical address d5 of each unit data (data stored for each block d1) included in the data file to be accessed is obtained from the file management processing layer P4 executed by the microcomputer 109. When specified, the logical address d5 is applied to the logical / physical conversion table (information) by the processing of the layers P1 to P3 below the logical address management layer P3, and the redundant bit obtained thereby is The block d1 (the storage position of the unit data in the flash memory 1 (data storage medium)) corresponding to the omitted physical address d6 ′ is accessed (an example of the first access step).
As a result, the block d1 corresponding to the designated logical address can be accessed.

<First embodiment: Example 2 of omitting part of physical address (omission of lower bit string)>
Next, an embodiment in which the consumption capacity of the main storage area is further suppressed by further omitting a part of the physical address d6 will be described.
In the example shown in FIG. 6B, only the redundant bit of the physical address d6 is omitted.
In the present embodiment, the logical / physical conversion table (information) in which the physical address d6 ″ in which the bit string corresponding to the predetermined length is omitted from the least significant side in each of the physical addresses d6 ′ is further stored in the RAM 112. In the main storage area (an example of the compression conversion table recording step).
In FIG. 6C, for each physical address 6 ′ after omitting redundant bits, a bit string of 6 bits (predetermined length) from the least significant side is omitted, that is, 6 bits to the right (lower side). (D) represents the shifted physical address d6 ″ (= 4 bits).
As a result, the storage area of the physical address d6 in the logical / physical conversion table can be reduced to about 4 KBytes while the main storage area in the RAM 112 has been consumed about 16 KBytes. Become.
However, in this case, the physical address d6 ″ from which the lower bit string is omitted indicates the range of the plurality of consecutive blocks d1.
For example, when the physical address d6 ″ after the lower bit string is omitted is “0xA”, the original physical address d6 corresponding to this indicates the range of “0x280” to “0x2BF”.
Therefore, when accessing the flash memory 1, first, the range of the block d1 (storage position of the data storage medium) represented by the physical address d6 ″ with the lower-order bit string omitted is accessed. The logical address d5 stored in the flash memory 1 (data storage medium) corresponding to each block d1 (unit data storage position) is set in the redundant area d4 in FIG. Acquired and accesses the block d1 (unit data storage location) where this matches the logical address d5 designated from the file management processing layer P4 side (an example of the first access step). Processing is also realized by processing of the layers P1 to P3 below the logical address management layer P3 executed by the microcomputer 109. It is.
As described above, if the lower bit string of the physical address d6 is omitted, it is necessary to search the block d1 corresponding to the specified logical address d5 from the plurality of blocks d1, and the access speed is sacrificed accordingly. However, this is effective when priority is given to the suppression of the consumption capacity of the main storage area in the RAM 112.

<First Embodiment: Example of Compression of Physical Address>
Next, an embodiment in which the consumption capacity of the main storage area is further suppressed by compressing the physical address d6 will be described.
The example shown in FIGS. 6B and 6C is an example in which a part of the physical address d6 is omitted. However, as a program executed by the microcomputer 109, data compression and decompression by a lossless compression method is performed. An embodiment is also possible in which a compression / decompression program for performing the above is prepared and the consumed capacity of the main storage area is further reduced by compressing the physical address d6.
Specifically, all the physical addresses d6 are divided into one or a plurality of physical addresses as a plurality of physical address sets, and each physical address set is compressed by the lossless compression method by the compression / decompression program, The logical / physical conversion table in which a plurality of post-compression physical address sets obtained by compression is set is stored in the main storage area in the RAM 112 (an example of the compression conversion table recording step).
As a result, the capacity of the logical / physical conversion table stored in the main storage area in the RAM 112 is suppressed by the amount compressed by the lossless compression method capable of complete data restoration.
When accessing the flash memory 1, first, each unit data (stored for each block d1) included in the data file to be accessed is accessed from the file management processing layer P4 executed by the microcomputer 109. When the logical address d5 of the data) is designated, the one set of physical addresses after compression corresponding to the designated logical address d5 is decompressed by the compression / decompression program. Further, one physical address d5 corresponding to the specified logical address d5 is selected from the uncompressed physical addresses d5 obtained by the decompression process, and the block d1 (data) corresponding to the physical address d5 is selected. A storage location of the storage medium) (an example of the first access step). This access processing is also realized by processing of the layers P1 to P3 below the logical address management layer P3 executed by the microcomputer 109.
As a result, the block d1 corresponding to the designated logical address can be accessed.

Second Embodiment
In the above-described embodiment (first embodiment), the logical / physical conversion table having the physical address that is compressed or partially omitted is stored in the main storage area. Another embodiment (second embodiment) for reducing the consumption capacity of the storage area is also conceivable.
The size of the data files stored in the flash memory 1 is limited to a certain upper limit size, etc., so that the size of each data file is relatively small, and the number of data files used simultaneously is 1 or relatively Consider the case of a small number.
For example, in an application for playing back a movie, if a data file and the next data file are played back continuously, if it has a structure that can be played back without interruption due to data buffering, it will be a large data file. Can be stored in the flash memory 1 as a small-sized data file divided into a plurality of pieces, and if they are opened and used one by one, continuous reproduction is possible.
When such a data file is opened and played back, designated data according to file management information (so-called FAT information) in which the correspondence between the data file name and the logical address d5 of the data included in the data file is set. The reproduction is performed by obtaining the logical address d5 from the file name and accessing the physical address d6 corresponding to the logical address d5. Here, the file management information is managed by the file management processing layer P4 and stored (recorded) in a predetermined management information storage area in the flash memory 1.
In the application described above, it is sufficient to hold only the logical / physical conversion table related to the logical address d5 of data included in the designated data file in the main storage area in the RAM 112.

Therefore, in the second embodiment, the microcomputer 109 executes processing by the layers P1 to P3 below the logical address management layer P3, so that a data file (audio digital data or video digital data) designated as an access target is obtained. The logical / physical conversion table is stored in the RAM 112 in the microcomputer 109 (an example of information processing means) only for the logical address d5 of each piece of data (unit data) in the block d1 unit included in the file). Store in the main storage area (an example of the file unit conversion table recording step).
As a result, since the minimum logical / physical conversion table necessary for accessing the designated data file is only expanded in the main storage area, the consumption capacity of the main storage area can be suppressed.
Here, the data file is designated as an access target from the application processing layer P5 side to the file management processing layer P4. Further, the logical address d5 of the block d1 unit data included in the data file designated by the file management processing layer P4 is stored in the file management information in the flash memory 1 by the file management processing layer P4. It is read from the storage area.

When accessing the flash memory 1, the logical address d5 of each of the unit data (data stored for each block d1) included in the designated data file is stored in the logical / physical conversion table. And the block d1 (storage position of the data storage medium) corresponding to the physical address d6 obtained thereby is accessed (an example of the second access step).
FIG. 7 is a schematic diagram showing an example of the logical / physical conversion table in the case where data files are created in this way (second embodiment). In this example, the size of the data file designated as the access target is 32 MByte (upper limit).
As a result, in the case of the flash memory 1 having a capacity of 128 MBytes, the memory area of the physical address d6 in the logical / physical conversion table that has been consumed 16 Kbytes, regardless of the capacity of the flash memory 1 The maximum consumption is 4 KBytes.

  The present invention can be used for an access method from an information processing means to a data storage medium.

The block diagram showing the schematic structure of the recording / reproducing apparatus X which is an example of the information processing prime minister concerning embodiment of this invention. The figure showing the processing hierarchy of the file system in the recording / reproducing apparatus X. The figure which represented typically an example of the data structure in the storage area of the flash memory which the recording / reproducing apparatus X accesses. The figure for demonstrating the correspondence of a logical address and a physical address. The schematic diagram showing an example of the logical / physical conversion table produced in the conventional information processing apparatus. FIG. 6 is a schematic diagram illustrating an example of a logical / physical conversion table between a conventional case and a case according to the first embodiment of the present invention. The schematic diagram showing an example of the logical / physical conversion table in 2nd Embodiment of this invention.

Explanation of symbols

X ... Recording / playback device (information processing device)
1. Flash memory (data storage medium)
102 ... DSP (Digital Signal Processor)
DESCRIPTION OF SYMBOLS 103 ... Microphone 104 ... A / D converter 105 ... Speaker 106 ... D / A converter 107 ... Display driver 108 ... Display part 109 ... Microcomputer (information processing means)
110 ... operation unit 111 ... ROM
112 ... RAM (main storage area)
120... Memory attach / detach interface d1... Block (flash memory access unit)
d5 ... logical address d6, d6 ', d6 "... physical address

Claims (9)

The unit based on conversion table information from the logical address corresponding to each unit data stored in the data storage medium to the physical address corresponding to the storage location of the unit data in the storage area of the data storage medium by the information processing means In a method of accessing a data storage medium for accessing each data storage location,
A compression conversion table recording step for storing the conversion table information having the compressed or partially omitted physical address in a main storage area of the information processing means;
Accessing a storage location of the unit data of the data storage medium based on the compressed or partially omitted physical address obtained by applying the designated logical address to the conversion table information; Access process,
A method for accessing a data storage medium, comprising: The compression translation table recording step stores the translation table information having the physical address in which redundant bits in each physical address are omitted in the main storage area;
2. The method for accessing a data storage medium according to claim 1, wherein the first access step accesses a storage position of the data storage medium corresponding to the physical address from which the redundant bit is omitted. The compression conversion table recording step stores the conversion table information having the physical address in which a bit string of a predetermined length is omitted from the lowest side in each of the physical addresses in the main storage area;
The first access step corresponds to each storage position of the unit data in the data storage medium by accessing a range of storage positions of the data storage medium represented by the physical address in which the bit string is omitted. 3. The data storage medium according to claim 1, wherein the stored logical address is acquired and the storage position of the unit data in which the specified logical address matches is accessed. how to access. The compression conversion table recording step compresses one or a plurality of sets of the physical addresses by a lossless compression method, and stores the conversion table having a plurality of post-compression physical address sets obtained by the compression in the main storage area. To remember,
The data storage medium corresponding to one of the uncompressed physical addresses obtained by the first access step by expanding one set of the compressed physical addresses corresponding to the specified logical address 2. The method of accessing a data storage medium according to claim 1, wherein the storage location is accessed. The unit based on conversion table information from the logical address corresponding to each unit data stored in the data storage medium to the physical address corresponding to the storage location of the unit data in the storage area of the data storage medium by the information processing means In a method of accessing a data storage medium for accessing each data storage location,
A file unit conversion table recording step for storing the conversion table information in the main storage area of the information processing means only for the logical address of the unit data included in the data file designated as an access target;
A second access step of accessing a storage location of the data storage medium corresponding to the physical address obtained by applying the logical address of each of the unit data included in the data file to the conversion table information;
A method for accessing a data storage medium, comprising: Each storage position of the unit data based on conversion table information from a logical address corresponding to each unit data stored in the data storage medium to a physical address corresponding to the storage position of the unit data in the storage area of the data storage medium In an information processing device that accesses
Compression conversion table recording means for storing the conversion table information having the compressed or partially omitted physical address in a main storage area of the information processing means;
Physical address generation means for generating the physical address after decompression or without omission from the compressed or partially omitted physical address obtained by applying the designated logical address to the conversion table information;
First access means for accessing a storage location of the data storage medium corresponding to the physical address after decompression or without omission;
An information processing apparatus comprising: Each storage position of the unit data based on conversion table information from a logical address corresponding to each unit data stored in the data storage medium to a physical address corresponding to the storage position of the unit data in the storage area of the data storage medium In a method of accessing a data storage medium that accesses
File unit conversion table recording means for storing the conversion table information in the main storage area of the information processing means only for the logical address of the unit data included in the data file designated as an access target;
Second access means for accessing a storage location of the data storage medium corresponding to the physical address obtained by applying the logical address of each of the unit data included in the data file to the conversion table information;
An information processing apparatus comprising: Each storage position of the unit data based on conversion table information from a logical address corresponding to each unit data stored in the data storage medium to a physical address corresponding to the storage position of the unit data in the storage area of the data storage medium In a program for accessing a data storage medium for causing a computer to execute processing for accessing
A compression conversion table recording process for storing the conversion table information having the compressed or partially omitted physical address in the main storage area of the information processing means;
Physical address generation processing for generating the physical address after being decompressed or not omitted from the compressed or partially omitted physical address obtained by applying the designated logical address to the conversion table information;
A first access process for accessing a storage location of the data storage medium corresponding to the physical address after decompression or not omitted;
A program for accessing a data storage medium for causing a computer to execute. Each storage position of the unit data based on conversion table information from a logical address corresponding to each unit data stored in the data storage medium to a physical address corresponding to the storage position of the unit data in the storage area of the data storage medium In a program for accessing a data storage medium for causing a computer to execute processing for accessing
A file unit conversion table recording process for storing the conversion table information in the main storage area of the computer only for the logical address of the unit data included in the data file designated as the access target;
A second access process for accessing a storage location of the data storage medium corresponding to the physical address obtained by applying the logical address of each of the unit data included in the data file to the conversion table information;
A program for accessing a data storage medium for causing a computer to execute.

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