JP2011154572A - Electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic device, which allows an application program to efficiently write or read data without regard to a bad block. <P>SOLUTION: The electronic device includes: a nonvolatile memory 44b; a plurality of access control parts 45a each of which accesses a predetermined block of the nonvolatile memory 44b; a volatile memory 44a which stores an address pair constituted by associating the head address of a defective block with the head address of a normal block to be alternated for the defective block; and an access execution part 45b which obtains, if a predetermined block of the nonvolatile memory 44b is a defective block in access of any one of the plurality of access control parts 45a thereto with a specified predetermined address, the address of the normal block to be alternated for this block in reference to the address pair, and executes the access to a block to which the obtained address is assigned. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electronic apparatus having a plurality of memories.

  2. Description of the Related Art In recent years, for example, electronic devices such as mobile phones often use flash memory that manages data in a storage unit called an addressed block as a storage medium for storing data.

  Here, Patent Document 1 describes a technique for providing a control unit that can handle any type of flash memory (for example, a NAND flash memory).

JP 2008-158991 A

  By the way, in the flash memory, for example, a block called a bad block (bad block) in which data cannot be normally written or read due to a hardware defect or the like may occur. Blocks that have become bad blocks can no longer be correctly accessed (reading, writing, and erasing data).

  Therefore, when an application program or the like accesses a flash memory having a bad block, data must be written or read while avoiding the bad block, so that the processing by the application program becomes complicated. It was.

  The present invention provides an electronic device that allows an application program or the like to efficiently write and read data without being aware of a bad block even when accessing a nonvolatile memory having a bad block. For one purpose.

  In order to solve the above problems, an electronic device according to the present invention is composed of a plurality of blocks defined by a predetermined capacity, and a data storage unit to which a unique address is assigned to each block, and respective controls In accordance with a method, a plurality of access control units that access a predetermined block of the data storage unit by designating an address, and when there is a defective block in the data storage unit, A predetermined address is specified by any one of the plurality of access control units and an address storage unit that stores an address pair configured by associating with a leading address of a normal block that substitutes for the defective block, and the data When a given block in the storage unit is accessed and that block is a bad block Above with reference to address pair to obtain the address of the normal block to replace the corresponding defective block, it comprises an obtained access execution unit for accessing the access control unit in the block to which the address is assigned.

  In the electronic device, the access execution unit is configured to execute the predetermined access when a predetermined address is specified by any of the plurality of access control units and a predetermined block of the data storage unit is accessed. It is preferable to determine that the predetermined block is a bad block on the condition that no access is made within a predetermined time after the access control unit is accessed with respect to the block and the access control unit is accessed. .

  Further, in the electronic device, the data storage unit stores the data block area composed of the plurality of blocks and the data stored in the defective block when the block of the data block area becomes a defective block. It is preferable that the non-volatile memory is constituted by a spare block area constituted by a plurality of spare blocks to be stored instead.

  According to the present invention, even when a nonvolatile memory having a bad block is accessed, an application program or the like can efficiently write and read data without being aware of the bad block.

1 is an external perspective view of a mobile phone device. It is a functional block diagram which shows the function of a mobile telephone apparatus. It is a figure with which it uses for description about the contrast in the case where the access execution part is not provided in the mobile telephone apparatus, and the case where it is provided. It is a figure with which it uses for description about the positioning of the access execution part in the whole system. It is a figure which shows the structure of an address table typically. It is a figure with which it uses for description about the operation | movement by which data is copied from a non-volatile memory to a volatile memory at the time of starting. It is a flowchart with which it uses for description about the flow of a process at the time of reading and writing data with respect to a non-volatile memory.

  Embodiments of the present invention will be described below. FIG. 1 is an external perspective view of a mobile phone device 1 which is an example of an electronic apparatus according to the present invention. 1 shows a form of a so-called foldable mobile phone device, the form of the mobile phone device according to the present invention is not particularly limited to this. For example, a sliding type in which one casing is slid in one direction from a state in which both casings are overlapped, or a rotary type in which one casing is rotated around an axis along the overlapping direction ( Turn type), or a type (straight type) in which the operation unit and the display unit are arranged in one housing and does not have a connecting unit.

The mobile phone device 1 includes an operation unit side body 2 and a display unit side body 3. The operation unit side body unit 2 includes an operation unit 11 and a microphone 12 to which a voice uttered by a user of the mobile phone device 1 is input on the surface unit 10. The operation unit 11 includes a function setting operation key 13 for operating various functions such as various settings, a telephone book function, a mail function, and the like, and an input operation key 14 for inputting a telephone number and characters such as mail. The operation key 15 includes a determination operation key 15 for performing determination and scrolling in various operations.
Further, the display unit side body unit 3 includes an LCD (Liquid Crystal Display) display unit 21 for displaying various types of information on the surface unit 20 and a speaker 22 for outputting the voice of the other party of the call. ing.

  Further, the upper end of the operation unit side body 2 and the lower end of the display unit side body 3 are connected via a hinge mechanism 4. In addition, the cellular phone device 1 relatively rotates the operation unit side body 2 and the display unit side body 3 connected via the hinge mechanism 4, thereby The display unit side body 3 can be opened (opened) with each other, or the operation unit side 2 and the display unit 3 can be folded (folded).

  FIG. 2 is a functional block diagram showing functions of the mobile phone device 1. As shown in FIG. 2, the cellular phone device 1 includes an operation unit 11, a microphone 12, a main antenna 40, an RF circuit unit 41, an LCD control unit 42, an audio processing unit 43, a memory 44, and a control. The unit 45 is provided in the operation unit side body 2, and the LCD display unit 21, the speaker 22, and the LCD driver 23 are provided in the display unit side body 3.

  The main antenna 40 communicates with a base station or the like in a first use frequency band (for example, 800 MHz), and can support a second use frequency band (for example, 1.5 GHz) for GPS communication. It is. In the present embodiment, the first frequency band used is 800 MHz, but other frequency bands may be used. Further, the main antenna 40 may be separately provided with an antenna that communicates with an external device in the first use frequency band and can correspond to the second use frequency band for GPS communication.

  The RF circuit unit 41 demodulates the signal received by the main antenna 40 and supplies the processed signal to the control unit 45. Then, the signal supplied from the control unit 45 is modulated and transmitted to an external device (base station) via the main antenna 40. On the other hand, the control unit 45 is notified of the strength of the signal received by the main antenna 40.

The LCD control unit 42 performs predetermined image processing under the control of the control unit 45, and outputs the processed image data to the LCD driver 23. The LCD driver 23 stores the image data supplied from the LCD control unit 42 in the frame memory and outputs it to the LCD display unit 21 or the sub LCD display unit 30 at a predetermined timing.
The sound processing unit 43 performs predetermined sound processing on the signal supplied from the RF circuit unit 41 under the control of the control unit 45, and outputs the processed signal to the speaker 22. The speaker 22 outputs the signal supplied from the sound processing unit 43 to the outside.

  In addition, the audio processing unit 43 processes the signal input from the microphone 12 according to the control of the control unit 45 and outputs the processed signal to the RF circuit unit 41. The RF circuit unit 41 performs a predetermined process on the signal supplied from the sound processing unit 43 and outputs the processed signal to the main antenna 40.

The memory 44 includes a volatile memory 44a (for example, an SDRAM (Synchronous DRAM)) and a nonvolatile memory 44b (a data storage unit) (for example, a NAND flash memory or a NOR flash memory). It consists of Further, the volatile memory 44 a has a function as a working memory used for arithmetic processing by the control unit 45. The nonvolatile memory 44b stores a plurality of applications and various tables necessary for the applications. Various applications are stored in the nonvolatile memory 44b. Here, the various applications include, for example, an application for viewing terrestrial digital broadcasting (hereinafter referred to as a one-segment application) A1, and a mail application for creating, transmitting, and receiving mail (hereinafter referred to as a mail application) A2. And a maintenance application (hereinafter referred to as a maintenance application) A3 used for a running change or the like.
The control unit 45 controls the entire mobile phone device 1 and is configured using a central processing unit (CPU) or the like.

  Here, the structure of the nonvolatile memory 44b will be described. In the nonvolatile memory 44b, the writing of the memory cell may not be completed in a specified time due to the consumption of the insulating part of the floating gate. Since such a block results in an error even if the program is executed, it needs to be excluded from the subsequent memory management target as a bad block (bad block). In addition, when a bad block occurs, valid data may still be stored in the block. In this case, after valid data is moved to a normal block, the bad block is excluded from the memory management target.

  It should be noted that since the NOR flash memory has higher data durability reliability than the NAND flash memory, it seems that no countermeasures against the bad block need be taken. However, a NOR type flash memory may become unusable due to an accident. Therefore, in the present embodiment, a countermeasure against a bad block is considered even for a NOR flash memory.

  The application stored in the nonvolatile memory 44b also performs processing on bad blocks. In the cellular phone device 1 according to the present embodiment, even if a bad block occurs in the nonvolatile memory 44b, it is possible to reduce the processing load on the bad block of each application and solve the problem due to the occurrence of the bad block. It has a function.

  Here, a specific configuration and operation for exerting the above-described functions will be described in detail. As shown in FIG. 2, the cellular phone device 1 includes an address storage unit 51, a data storage unit 52, an access control unit 45a, and an access execution unit 45b. In the present embodiment, it is assumed that the address storage unit 51 and the data storage unit 52 are integrally configured as a nonvolatile memory 44b.

  The non-volatile memory 44b is managed in units of blocks defined by a predetermined capacity, and each block is assigned a unique address, and a data block area including a plurality of blocks into which data is written, and the data block When a block in the area becomes a defective block, it is composed of a spare block area composed of a plurality of spare blocks that store data stored in the defective block instead.

  The access control unit 45a has a function of accessing a predetermined block of the nonvolatile memory 44b by designating an address. In the present embodiment, the access control unit 45a is a concept in which a plurality of access control units having different control methods are grouped. For example, the access control unit 45a includes a file system 100 that can be used after an OS (operation system) is completely started, and a downloader 101 that can be used even if the OS is not fully started. It is assumed that it is configured by

  The volatile memory 44a (address storage unit) is configured such that when a defective block exists in the nonvolatile memory 44b, the leading address of the defective block is associated with the leading address of a normal block that replaces the defective block. Address pair (address table) AT is stored.

  The access execution unit 45b is a defective block when a predetermined address is designated by any of the plurality of access control units 45a and a predetermined block of the nonvolatile memory 44b is accessed. In this case, the address of the normal block that substitutes the block is obtained by referring to the address table AT, and the access control unit 45a is accessed to the block to which the obtained address is attached.

  Here, the concept of the access execution unit 45b will be described. The access execution unit 45b realizes a bad block management system that allows the client C (a concept corresponding to various applications such as the one-segment application A1) to access the nonvolatile memory 44b without being aware of the bad block. .

When the client C directly accesses the nonvolatile memory 44b, the client C needs to execute the process for the bad block of the nonvolatile memory 44b (see FIG. 3A).
The cellular phone device 1 according to the present embodiment is configured such that the access execution unit 45b is interposed between the client C and the nonvolatile memory 44b. When the block corresponding to the address instructed by the client C is a bad block, the access execution unit 45b appropriately performs address conversion so as to access the alternative block. Therefore, since the client C apparently recognizes that it is always accessing a normal block (good block), it is not necessary to execute processing for the bad block by itself (see FIG. 3B).
In this manner, the cellular phone device 1 can realize access to the nonvolatile memory 44b without making the client C aware of bad blocks.

  Further, when the configuration of the cellular phone device 1 is expressed as a physical layer L1, a driver layer L2, a service layer L3, and an application layer L4, the access execution unit 45b includes the service layer L3 and the driver layer as shown in FIG. This corresponds to the intermediate position of L2.

  For example, the one-segment application A1 belonging to the application layer L4 activated by a predetermined operation uses the main antenna 40 belonging to the physical layer L1 via the protocol 103 belonging to the service layer L3 and the RF driver 201 belonging to the driver layer L2. And receive terrestrial digital broadcasting. Also, the one-segment application A1 displays the tuned channel display image on the LCD display unit 21 belonging to the physical layer L1 via the drawing service unit 102 belonging to the service layer L3 and the LCD driver 23 belonging to the driver layer L2. Further, the one-segment application A1 passes through the file system 100 belonging to the service layer L3, the access execution unit 45b, and the memory driver 200 belonging to the driver layer L2 to a predetermined block of the nonvolatile memory 44b belonging to the physical layer L1. Save image data.

  In addition, the maintenance application A2 belonging to the application layer L4 passes through the file system 100 or downloader 101 belonging to the service layer L3, the access execution unit 45b, and the memory driver 200 belonging to the driver layer L2 in accordance with the OS activation state. The maintenance data is stored in a predetermined block of the nonvolatile memory 44b belonging to the physical layer L1. The maintenance application A2 uses the file system 100 or the downloader 101 belonging to the service layer L3 according to the OS activation state.

  The mail application A3 belonging to the application layer L4 activated by a predetermined operation uses the main antenna 40 belonging to the physical layer L1 via the protocol 103 belonging to the service layer L3 and the RF driver 201 belonging to the driver layer L2. Send and receive emails. Further, the mail application A3 displays the text of the mail on the LCD display unit 21 belonging to the physical layer L1 via the drawing service unit 102 belonging to the service layer L3 and the LCD driver 23 belonging to the driver layer L2. The mail application A3 sends a mail to a predetermined block of the nonvolatile memory 44b belonging to the physical layer L1 via the file system 100 belonging to the service layer L3, the access execution unit 45b, and the memory driver 200 belonging to the driver layer L2. Save.

  Further, the access execution unit 45b accesses the access control unit 45a to the normal block by referring to the address table AT stored in the nonvolatile memory 44b via the memory driver 200 belonging to the driver layer L2. Let Here, for example, as shown in FIG. 5, the address table AT is configured by associating a save source address (bad block address) and a save destination address (reserve block address). In the present embodiment, the address table AT is described as being stored in the nonvolatile memory 44b, but the storage location is not limited to this.

  Further, as shown in FIG. 6, the access execution unit 45b stores a program stored in a predetermined block of the nonvolatile memory 44b in the program area of the volatile memory 44a when the power is supplied and the OS is started. The function is demonstrated by being read and expanded. Similarly, as shown in FIG. 6, the address table AT stored in a predetermined block of the nonvolatile memory 44b is stored in the working area of the volatile memory 44a when power is supplied and the OS is started. Copied.

  Further, the access execution unit 45b, when a predetermined address is specified by any of the plurality of access control units 45a and a predetermined block of the nonvolatile memory 44b is accessed, the predetermined block is accessed. The access control unit 45a is accessed, and the predetermined block is determined to be a bad block on the condition that there is no response within a predetermined time.

  Here, when the nonvolatile memory 44b is composed of a NAND flash memory, each block detects a data error, and a spare for correcting the detected data error (ECC, Error Check and Correct). An area exists. Therefore, the access execution unit 45b performs ECC on the accessed block, finds an error in the data, and cannot correct the error (for example, when there is an error of 2 bits or more), A block can be determined as a bad block.

  On the other hand, when the nonvolatile memory 44b is configured by a NOR flash memory, unlike the NAND flash memory, there is no spare area for ECC. Therefore, the access execution unit 45b executes access to a predetermined block of the NOR flash memory, and when there is no response within a predetermined time, that is, when a time-out occurs, the accessed block is a bad block. Judge.

  With this configuration, the cellular phone device 1 can perform bad block determination regardless of whether the nonvolatile memory 44b is configured by a NAND flash memory or a NOR flash memory. it can.

  In the mobile phone device 1, the access execution unit 45b determines whether the block relating to the address instructed by the client C is a bad block. If the block is a bad block, the mobile phone device 1 refers to the address table AT. The address of the normal block to be replaced is acquired, and the block with the acquired address is accessed.

  Therefore, the cellular phone device 1 can efficiently write and read data to and from the nonvolatile memory 44b without the application as the client C being aware of the bad block.

  Next, processing for reading data from and writing data to the nonvolatile memory 44b will be described with reference to the flowchart shown in FIG.

  In step ST1, the control unit 45 performs an exclusive process (exclusive lock). This process is executed only when the OS is activated.

  In step ST2, the control unit 45 receives a request to access a specific address from the activated OS or program. When receiving the request, the control unit 45 confirms (checks) whether or not a specific address (block address) is stored in the address table AT.

  In step ST3, the control unit 45 confirms whether or not the address table AT exists in the working area of the volatile memory 44a in the process of step ST2. The case where the address table AT does not exist in the working area of the volatile memory 44a is, for example, the case where the address table AT is broken due to an accident. If the address table AT does not exist (No), the process ends abnormally, and the process proceeds to step ST11. If the address table AT exists (Yes), the process proceeds to step ST4.

  In step ST4, the control unit 45 accesses the address requested to be accessed in page units by referring to the address table AT.

  In step ST5, the control unit 45 confirms (checks) whether or not the correct data has been accessed based on the address requested to be accessed in the process of step ST4. If the correct data can be accessed (Yes), the process proceeds to step ST12. If the correct data cannot be accessed (No), the process proceeds to step ST6.

  Here, “when the correct data is accessed” means that the address requested to access points to the page address on the bad block, and the address table AT stores the address pair of the save destination address and the save source address. If you are. In this case, since the control unit 45 can correctly access the spare block corresponding to the bad block, the control unit 45 ends the process assuming that the data requested to be accessed normally can be accessed, and proceeds to step ST12.

  If the block in which the page indicated by the page address requested to access is a normal block that is not a bad block, the control unit 45 accesses the correct data without performing address conversion by the address table AT. Therefore, as in the case of “when correct data can be accessed”, the processing is terminated assuming that the data requested to be normally accessed can be accessed, and the process proceeds to step ST12.

  In addition, the case where “correct data could not be accessed” refers to cases other than the two patterns described above, that is, if access is performed assuming that the page address is a normal block, the accessed block is a bad block. This is the case. In other words, “when the correct data could not be accessed” refers to a case where a new bad block has occurred when accessed.

  In step ST6, the control unit 45 confirms whether or not the accessed page is the first page of the bad block. If the accessed page is the first page of the bad block (Yes), the process proceeds to step ST7. If the accessed page is not the first page of the bad block (No), the process proceeds to step ST8.

  In step ST7, the control unit 45 secures a new spare block. Then, the control unit 45 creates an address pair using the reserved spare block address and bad block address as the save destination address and save source address, respectively, and stores them in the address table AT.

  In step ST8, the control unit 45 secures a new spare block. Then, the control unit 45 copies the data in the bad block to the reserved spare block. Then, the control unit 45 creates an address pair using the reserved spare block address and bad block address as the save destination address and save source address, respectively, and stores them in the address table AT.

  Here, “when the accessed page is not the first page of the bad block” in the process of step ST6 means that some data has already been written in the bad block. Therefore, if only the address of the bad block is extracted and added to the address table AT as in the step ST7, the data already written in the bad block cannot be used.

  Therefore, when the accessed page is not the first page of the bad block, the control unit 45 secures a new spare block and copies the data in the bad block to the reserved spare block. An address pair is created with the address of the spare block and the address of the bad block as the save destination address and the save source address, respectively, and stored in the address table AT.

In step ST9, the control unit 45 confirms whether or not the process of step ST7 or the process of step ST8 has succeeded (normally ended). If the process has not ended normally (No), the process proceeds to step ST11 as in the case where “the address table AT does not exist (No)” in the process of step ST3, and if the process has ended normally (Yes) ) Go to step ST10.
Note that a series of processes from the case where correct data cannot be accessed through the process of step ST5 to the process of step S10 described later is a process when a new bad block is found.

  In step ST10, the control unit 45 determines whether or not the newly secured spare block is a bad block. If the newly secured spare block is a bad block (Yes), the process returns to step ST2, and if the newly secured spare block is not a bad block (No), that is, the spare block to which the bad block is saved is If it is a normal block, the process proceeds to step ST12.

  Here, if the newly secured spare block is a bad block (Yes), the control unit 45 newly creates a spare block that is the save destination of the spare block (that is, a spare block for the spare block). There must be. Therefore, when the spare block newly secured by the process of step ST10 is a bad block (Yes), the control unit 45 returns to step ST2 to secure the spare block for the spare block or add to the address table AT. Etc. Note that the operation of securing a spare block for this spare block is not repeated indefinitely, but a maximum value (for example, 42 times) may be set according to specifications.

  In step ST11, the control unit 45 determines that the address table AT does not exist in the process of step ST3, or determines that the process has not ended normally in the process of step ST9. Will end abnormally, and an error code will be set and the process will end.

  In step ST12, the control part 45 cancels | releases the said exclusive lock, when the exclusive lock was performed by the process of step ST1.

Here, the main effects exhibited by the mobile phone device 1 are listed below.
1. In the cellular phone device 1, it is possible to make the bad block of the nonvolatile memory 44 b (NAND flash memory or the like) not be conscious of the host system (application layer L 4) in a pseudo manner. This eliminates the need for the upper system (application layer L4) to assume that every bad block exists in one area every time the area is divided.
2. In the conventional mobile phone device, since the file system belonging to the service layer L3 directly accesses the nonvolatile memory, it is necessary to include a corresponding driver. However, the mobile phone device 1 according to the present embodiment includes an access execution unit. The file system itself belonging to the service layer L3 does not directly access the nonvolatile memory 44b. Therefore, in the mobile phone device 1, a file system belonging to the service layer L3 can be freely designed.
3. The cellular phone device 1 enables writing to a single memory of a file system in a ROM writer, which has been realized with a NOR flash memory, also with respect to a NAND flash memory.

1 Mobile phone device 44 Memory 44a Volatile memory 44b Non-volatile memory 45 Control unit 45a Access control unit 45b Access execution unit 51 Address storage unit 52 Data storage unit

Claims (3)

A data storage unit composed of a plurality of blocks defined by a predetermined capacity, to which a unique address is attached;
According to each control method, a plurality of access control units that access a predetermined block of the data storage unit by designating an address;
When there is a defective block in the data storage unit, an address storage unit that stores an address pair configured by associating a leading address of the defective block with a leading address of a normal block that replaces the defective block;
When a predetermined address is designated by any of the plurality of access control units and a predetermined block of the data storage unit is accessed, if the block is a bad block, the address pair is An electronic apparatus comprising an access execution unit that refers to obtain an address of a normal block that substitutes for the defective block, and causes the access control unit to access the block to which the obtained address is attached. The electronic device according to claim 1,
The access execution unit is configured to access the predetermined block when a predetermined address is specified by any of the plurality of access control units and a predetermined block of the data storage unit is accessed. An electronic device that accesses an access control unit and determines that the predetermined block is a bad block on condition that no response is received within a predetermined time after the access control unit is accessed. The electronic device according to claim 1,
The data storage unit stores a data block area composed of the plurality of blocks and data stored in the defective block instead of the data block area when the block in the data block area becomes a defective block. An electronic device which is a non-volatile memory composed of a spare block area composed of spare blocks.

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