JP6015461B2 - Information recording medium, data read / write method, and data read / write program - Google Patents

Description

  The present invention includes a non-volatile memory having a storage area divided into a plurality of blocks, each block having a physical block number forming a physical address space, and the non-volatile memory according to a command The present invention relates to a technology of an IC card provided with a controller that reads and writes data with respect to the device.

  Currently popular IC cards operate using power supplied from an external terminal. Therefore, if an action to shut off the power supply such as pulling out the IC card from the external terminal during data writing is performed, the power necessary for the operation is not supplied, and the data stored in the non-volatile memory of the IC card It will be destroyed. Therefore, in the writing process, data integrity must be ensured by completing writing normally or returning to a state before writing. Further, an IC card used for electronic money or an ID card needs to be devised so as not to deteriorate the processing speed so as not to impair the convenience of the user.

  Patent Document 1 discloses an IC card and an information processing method thereof capable of executing processing efficiently and at high speed while ensuring data guarantee at the time of power interruption even when a large-capacity data block area is handled. Is disclosed. The non-volatile memory of the IC card disclosed in Patent Document 1 includes a data block area in which data required by the user is stored, and a spare in which data specified when reading / writing data from the reader / writer to the IC card is stored. It has a block area and an address management area in which address information for associating a logical memory space with a physical memory space in the nonvolatile memory of the IC card is stored. During the writing process, the address management area is updated so that the target data is written to the block in the spare block area instead of the block in the data block area to be written, and the block is replaced with the block to be written. It has become.

Japanese Patent No. 3920166

  By the way, in the technique of Patent Document 1, at the time of the writing process, the address management area is updated after the writing to the block of the spare block area is completed. However, the address management area manages the data block storage area (that is, manages the address information (table) that associates the logical memory space with the physical memory space), and manages the spare block area (that is, Therefore, a block (that is, 3 blocks) is updated three times in one writing process. For this reason, the write processing speed is reduced compared to a general data guarantee method (a method in which the write target area is temporarily saved and backed up in another area on the nonvolatile memory before executing the write process). There is a possibility.

  Accordingly, an object of the present invention is to provide an information recording medium, a data read / write method, and a data read / write program capable of improving the writing processing speed as compared with a general data guarantee method.

  In order to solve the above problems, the invention described in claim 1 has a storage area divided into a plurality of blocks including a data storage area block, a spare area block, and a spare area management block. An information recording medium comprising: a non-volatile memory to which a physical block number that forms a physical address space is assigned; and a controller that reads and writes data to and from the non-volatile memory in response to a command, the data storage area block The logical block number forming the data and logical address space is stored in, the initialized value is stored in the spare area block, and the physical block number of the spare area block is stored in the spare area management block The controller performs data write processing in response to the command First search means for searching for the spare area block with reference to the spare area management block, and second for searching for the data storage area block storing the logical block number calculated according to the command The spare area block searched by the search means and the first search means is stored in the spare area block as a new data storage area block and stored in the data storage area block searched by the second search means. A first writing means for writing update data corresponding to the data and the logical block number calculated in accordance with the command; and the physical block of the data storage area block searched by the second searching means The update by the first writing means with the number as the physical block number of a new spare area block Characterized in that it comprises a second writing means for writing after writing over data to the spare area management block.

  According to a second aspect of the present invention, in the information recording medium according to the first aspect, the data storage area block stores a usage counter indicating the number of times the data storage area block is used. The use means increments the use counter stored in the data storage area block searched by the second search means when the update data and the logical block number are written to the spare area block. A counter is written into the spare area block.

  According to a third aspect of the present invention, in the information recording medium according to the first or second aspect, the second writing unit includes the first of the plurality of spare area blocks retrieved by the first retrieval unit. The spare area block for which the update data has not been written by the writing means is used as the new spare area management block, the physical block number of the new spare area block, and the new data storage An area block and the physical block number of the spare area block that has not been used as the new spare area management block are written.

  According to a fourth aspect of the present invention, in the information recording medium according to any one of the first to third aspects, error check information is further stored in the spare area management block, and the controller If the spare area block searched by one search means is not unused, or if writing by the second writing means does not end normally, it is determined whether there are two or more spare area management blocks. When it is determined by the first determination means and the first determination means that there are two or more spare area management blocks, it is determined whether the error check information stored in the newest spare area management block is normal And when the error check information stored in the spare area management block is determined to be normal by the second determination unit and the second determination unit, While the spare area block corresponding to the physical block number stored in the area management block is initialized, the error determination information stored in the spare area management block is determined to be not normal by the second determination unit. In this case, an initialization means is provided for initializing the spare area block corresponding to the physical block number stored in the spare area management block other than the spare area management block.

  The invention according to claim 5 has a storage area divided into a plurality of blocks including a data storage area block, a spare area block, and a spare area management block, and a physical block forming a physical address space in each block A data read / write method performed by the controller in an information recording medium comprising: a non-volatile memory to which a number is assigned; and a controller for reading and writing data to and from the non-volatile memory in response to a command, the data storage area The block stores data and logical block numbers forming a logical address space, the spare area block stores initialized values, and the spare area management block stores the physical block number of the spare area block. The data read / write method is stored in the command. When a data write process is performed for the first time, a first search step for searching for the spare area block with reference to the spare area management block and the logical block number calculated according to the command are stored. A second search step for searching for the data storage area block; and the spare area block searched in the first search step is searched as a new data storage area block in the spare area block by the second search step. The first write step for writing the update data corresponding to the data stored in the data storage area block and the logical block number calculated in response to the command, and the second search step are used for retrieval. The physical block number of the data storage area block is changed to a new spare area block. Wherein as the physical block number, characterized in that it comprises a second writing step of writing the reserved area management block after the writing of the update data by the first writing step.

  The invention according to claim 6 has a storage area divided into a plurality of blocks including a data storage area block, a spare area block, and a spare area management block, and a physical block forming a physical address space in each block A data read / write program executed by the controller in an information recording medium, comprising: a non-volatile memory to which a number is assigned; and a controller that reads and writes data to and from the non-volatile memory in response to a command, the data storage A logical block number forming data and a logical address space is stored in the area block, an initialized value is stored in the spare area block, and the physical block number of the spare area block is stored in the spare area management block Is stored, and the command is sent to the controller. The first search means for searching for the spare area block with reference to the spare area management block when performing the data write process in response, the logical block number calculated according to the command is stored A second search means for searching for a data storage area block, and the spare area block searched by the first search means as a new data storage area block, the spare area block searched by the second search means Searched by the first writing means and the second searching means for writing the update data corresponding to the data stored in the data storage area block and the logical block number calculated in response to the command. The physical block number of the data storage area block is changed to the physical block of the new spare area block. No. As, characterized in that function as a second writing means for writing after writing of the update data by the first writing means to said spare area management block.

  According to the present invention, it is possible to realize writing in which data is guaranteed only by writing two blocks in one writing process, and the writing processing speed can be improved.

1 is a diagram illustrating a schematic configuration example of an IC card 1. FIG. (A) is a diagram showing a physical address space in the flash memory according to the present embodiment, and (B) is a diagram showing a logical address space in the flash memory according to the present embodiment. 4 is a flowchart showing a writing process executed by a CPU 11. 5 is a flowchart showing details of a spare area management block update process in step S8 shown in FIG. 3; It is a flowchart which shows the detail of the rollback process in step S11 shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  First, an IC card according to this embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram illustrating a schematic configuration example of the IC card 1. FIG. 2A is a diagram showing a physical address space in the flash memory according to this embodiment, and FIG. 2B is a diagram showing a logical address space in the flash memory according to this embodiment. The IC card 1 is used as a cash card, credit card, employee card or the like. Alternatively, the IC card 1 is incorporated into a smartphone, a mobile phone, or the like. In addition to the card, the IC card 1 may be an information recording medium such as an embedded device equipped with a non-volatile memory or a USB memory requiring data security.

  As shown in FIG. 1, an IC chip 1 a is mounted on the IC card 1. The IC chip 1a includes a CPU (Central Processing Unit) 11, a RAM (Random Access Memory) 12, a flash memory 13, and an I / O circuit 14. Note that an EEPROM (Electrically Erasable Programmable Read-Only Memory) may be used instead of the flash memory.

  The CPU 11 is a controller that executes various programs. For example, according to the data read / write program of the present invention incorporated in an operating system (OS), the CPU 11 executes predetermined command processing corresponding to the command received from the external terminal 2, and the RAM 12 and Data read / write processing to the flash memory 13 is performed. For example, the CPU 11 erases and reads / writes from / to the flash memory 13 in units of pages (the minimum unit for reading and writing, for example, 128 bytes, 256 bytes, or 512 bytes). The external terminal 2 includes a reader / writer for performing communication with or without contact with the IC card 1. Examples of the external terminal 2 include an ATM, a ticket gate, and an authentication gate. Alternatively, when the IC card 1 is mounted on a mobile terminal, the external terminal 2 corresponds to a control unit responsible for the function of the mobile terminal.

  The RAM 12 is a volatile memory that temporarily stores data. The flash memory 13 is a non-volatile memory that stores programs (including the data read / write program of the present invention) and data. In the flash memory 13, when the stored data is rewritten, a page-by-page erase process (0 → 1 or 1 → 0) and a 1-byte write process (1 → 0 or 0 → 1) occur. The flash memory 13 has a storage area divided into a plurality of blocks including a data storage area block, a spare area block, and a spare area management block. Each block has a physical address space (physical address space). ) To form a physical block number. A block is a series of one or more pages. The physical address space means a memory space accessible by a memory address. In the present embodiment, data security is achieved by classifying blocks into three types, and the write processing time and memory use efficiency are improved.

  In the example of FIG. 2A, the blocks having physical block numbers Nx “01”, “02”, and “04” are data storage area blocks, respectively. In addition, blocks having physical block numbers Nx “03”, “05”, “06”, and “7F” are spare area blocks, respectively. A block having the physical block number Nx “80” is a spare area management block. In the data storage area block, a logical block number Ny, a usage counter C, data D, and error check information P are stored (stored). The logical block number Ny is information for forming (constructing) a logical address space (logical address space) as shown in FIG. The usage counter C is a value indicating the number of times the data storage area block that stores the usage counter C is used, and is 1 each time the data storage area block is used by writing data D to the data storage area block. Incremented. The usage counter C can determine whether each block is new or old, and can manage the number of times the block is used. The data D is, for example, data output to the external terminal 2 based on the result of command processing by the CPU 11. An example of the data D is a value held in the IC chip 1a or a value obtained as a result of calculation in the IC chip 1a. For example, in the data storage area block in which the logical block number Ny “01” is stored, key data is stored as the data D, and in the data storage area block in which the logical block number Ny “02” is stored, the data The logical block number Ny is associated with the type of data D such that reward points (or dates) are stored as D. The error check information P is information for determining whether or not the value of data in the block in which the error check information P is stored is valid. Examples of the error check information P include CRC (Cyclic Redundancy Check, CRC) and checksum. On the other hand, an initialized value (for example, FFFF...) Is stored in the spare area block. The spare area management block stores a spare area management block identifier ID, a usage counter C, a physical block number Nx of the spare area block, and error check information P. The spare area management block identifier ID is identification information given to the spare area management block in order to identify the spare area management block. In the example of FIG. 2A, one spare area management block is shown. However, the number of spare area management blocks is not limited to one, and all physical block numbers of spare area blocks can be stored in one block. If this is not possible, a plurality of spare area management blocks are secured. The spare area block is managed by storing the physical block number Nx of the spare area block in the spare area management block.

  By the way, if a table for converting a physical block number to a logical block number is stored in the spare area management block, the possibility that the table extends over a plurality of pages increases. This results in a decrease in the writing processing speed in the flash memory 13 in which the erasing process in units of pages and the 1-byte writing process occur when data is rewritten. In this embodiment, although the spare area block is managed by the spare area management block, the table for converting the physical block number to the logical block number is not managed, so that the table can be prevented from extending over a plurality of pages. The writing processing speed can be improved.

  The I / O circuit 14 serves as an interface with the external terminal 2. The I / O circuit 14 is provided with eight terminals C1 to C8 defined by, for example, ISO / IEC7816. For example, the C1 terminal is a power supply terminal, the C2 terminal is a reset terminal, the C3 terminal is a clock terminal, the C5 terminal is a ground terminal, and the C7 terminal is a terminal that performs data communication with the external terminal 2.

  When the CPU 11 performs a data write process in response to a command from the external terminal 2, the CPU 11 searches for a spare area block by referring to the spare area management block by functioning as a first retrieval unit in the present invention. The data storage area block storing the logical block number Ny calculated in response to the command is searched by functioning as the second search means in the present invention. Here, the logical block number Ny is calculated from the write destination logical address specified by the command and the data size per block.

  Further, the CPU 11 functions as the first writing means in the present invention, so that the spare area block searched by the first searching means is used as a new data storage area block in the spare area block. The update data Dz corresponding to the data D stored in the data storage area block retrieved by the above and the logical block number Ny calculated according to the command are written. Further, when the CPU 11 writes the update data Dz and the logical block number Ny to the spare area block, the usage counter C is obtained by incrementing the usage counter stored in the data storage area block searched by the second search means. Are written into the spare area block. For example, the spare area block having the physical block number Nx “03” shown in FIG. 2A is searched by the first search means, and the data storage area block having the physical block number Nx “01” is searched by the second search means. Suppose that In this case, the update data Dz corresponding to the data D “33333333...” Stored in the data storage area block with the physical block number Nx “01” (for example, a value overwriting “33333333...”) Is the same. The logical block number Ny “03” stored in the data storage area block and the usage counter C “03” obtained by incrementing the usage counter C “02” stored in the data storage area block by one are the physical block number Nx. It is written in the spare area block of “03”. At this time, the error check information P is newly calculated based on the written value, and is written in the spare area block having the physical block number Nx “03”. The spare area block thus written becomes a new data storage area block.

  Further, the CPU 11 functions as the second writing means in the present invention, so that the physical block number Nx of the data storage area block searched by the second searching means is used as the physical block number Nx of the new spare area block. After the update data Dz is written, it is written in the spare area management block. That is, the data storage area block searched by the second search means becomes old and is therefore managed as a new spare area block. In this case, if a plurality of spare area blocks are searched by the first search means, the CPU 11 newly adds any spare area block in which the update data Dz is not written among the plurality of searched spare area blocks. And a physical block number Nx of the new spare area block (an old data storage area block) (in the example of FIG. 2A, “01”). The physical block numbers Nx (“05” and “06” in the example of FIG. 2A) of spare area blocks that are not used as new spare area management blocks are written. As a result, the data storage area block can be used efficiently. At this time, the spare area management block identifier ID “AA” stored in the original spare area management block and the usage counter C “13” obtained by incrementing the usage counter C “12” stored in the spare area management block are incremented by one. "And the newly calculated error check information P are written into a new spare area management block.

  Further, the CPU 11 executes a rollback process in order to restore the state before the writing process occurs or to complete the writing process when a power interruption occurs due to failure or pulling out of the writing. In this rollback process, the CPU 11 functions as the first determination means in the present invention, so that the spare area block retrieved by the first retrieval means is not unused, or the physical block number to the spare area management block If the Nx writing does not end normally, it is determined whether there are two or more spare area management blocks. The case where there are two or more spare area management blocks corresponds to, for example, a case where a power interruption occurs during writing to a new spare area management block or immediately after writing.

  When the CPU 11 determines that there are two or more spare area management blocks, the error check information P stored in the newest spare area management block is normal by functioning as the second determination means in the present invention. Determine if there is. When the CPU 11 determines that the error check information P stored in the spare area management block is normal, the CPU 11 functions as an initialization unit in the present invention, so that the physical block stored in the newest spare area management block The spare area block corresponding to the number Nx is initialized (for example, FFFF ... is written). In this case, since the information in the most recently created spare area management block can be estimated to be accurate, a spare area block is secured by initializing the spare area block indicated by this information. On the other hand, when it is determined that the error check information P stored in the spare area management block is not normal, the CPU 11 functions as an initializing unit in the present invention to thereby manage spare area management other than the newest spare area management block. The spare area block corresponding to the physical block number Nx stored in the block is initialized. In this case, since the information in the most recently created spare area management block can be estimated to be inaccurate, the spare area is initialized by initializing the spare area block indicated by the information in the old spare area management block that originally existed. Block is secured. By such a rollback process, data can be ensured even in the case where a power interruption occurs due to failure in writing or pulling out.

  Next, details of the writing process will be described with reference to FIGS. FIG. 3 is a flowchart showing the writing process executed by the CPU 11. FIG. 4 is a flowchart showing details of the update process of the spare area management block in step S8 shown in FIG. FIG. 5 is a flowchart showing details of the rollback process in step S11 shown in FIG.

  The process shown in FIG. 3 is started when the CPU 11 receives a write command from the external terminal 2 via the I / O circuit 14, for example. When the processing shown in FIG. 3 is started, the CPU 11 refers to the spare area management block to search for the spare area block, and stores the physical block number Nx (may be a physical address) of the searched spare area block in the RAM 12, for example. Store and hold (step S1). That is, the CPU 11 obtains a spare area management block by the spare area management block identifier ID, searches the physical address space, and holds the physical block number Nx of the spare area block in the found spare area management block.

  Next, the CPU 11 determines whether or not there is an unused spare area block based on the physical block number Nx held in step S1 (step S2). For example, if the spare area block assigned with the physical block number Nx held in step S1 is filled with an initialized value (for example, FFFF...), It is determined that there is an unused spare area block. Is done. If it is determined that there is an unused spare area block (step S2: YES), the process proceeds to step S3, and it is determined that there is no unused spare area block (that is, the searched spare area block is not unused). If it is determined (step S2: NO), the CPU 11 ends the writing as an abnormal end, and proceeds to the rollback process (step S11). Details of the rollback processing will be described later.

  In step S3, the CPU 11 calculates a logical block number Ny from the write destination logical address specified by the command. Next, the CPU 11 searches for the data storage area block storing the logical block number Ny calculated in step S3, and stores the physical block number Nx (may be a physical address) of the searched data storage area block in the RAM 12, for example. Store and hold (step S4). That is, the CPU 11 searches the physical address space for a data storage area block that matches the logical block number Ny, and holds the physical block number Nx of the found data storage area block.

  Next, the CPU 11 reads the data in the retrieved data storage area block (hereinafter referred to as “block data”, including the logical block number Ny, the usage counter C, the data D, and the error check information P) into the RAM 12. The write data is constructed based on the read block data and the data specified by the command (step S5). For example, on the RAM 12, the use counter C included in the read block data is incremented by 1, and the data D included in the block data is updated to the update data Dz with the data specified by the command. Then, the logical block number Ny included in the read block data, the counter C incremented by 1, the updated update data Dz, and error check information calculated based on these data, for example, by a CRC arithmetic expression Write data is constructed by P.

  Next, the CPU 11 writes the write data constructed in step S5 to the spare area block corresponding to the physical block number Nx held in step S1 (step S6). That is, the write data constructed in step S5 is written into the spare area block using the spare area block searched in step S1 as a new data storage area block.

  Next, the CPU 11 determines whether or not writing of all data designated by the command has been completed (step S7). If the CPU 11 determines that writing of all data has not been completed (step 7: NO), the CPU 11 returns to step S2 and performs the same processing as described above. On the other hand, when the CPU 11 determines that all data has been written (step 7: YES), the CPU 11 proceeds to step S8.

  In step S8, the CPU 11 executes the spare area management block update process to register the old data storage area block as a spare area block in the spare area management block and update the spare area management block. Details of the spare area management block update process will be described later.

  Next, the CPU 11 determines whether or not the update of the spare area management block has been normally completed (step S9). That is, it is determined whether or not the writing of the physical block number Nx to the spare area management block has been completed normally. If the CPU 11 determines that the update of the spare area management block has not ended normally (step 9: NO), the CPU 11 ends the writing as an abnormal end and proceeds to the rollback process (step S11). On the other hand, when the CPU 11 determines that the update of the spare area management block has been normally completed (step 9: YES), the CPU 11 proceeds to step S10.

  In step S10, the CPU 11 erases the used (old) data storage area block and the used spare area management block (that is, initializes data in the block), and ends the writing process. Note that the process of step S10 may be configured not to be performed in the writing process but to be performed, for example, when an IC card 1 reset command is issued.

  Next, in the update process of the spare area management block shown in FIG. 4, the CPU 11 first sets the spare area block to be used as the updated spare area management block in the physical block number Nx held in step S1, for example. (Step S81).

  Next, the CPU 11 determines whether or not there is an unused spare area block as in step S2 (step S82). If it is determined that there is an unused spare area block (step S82: YES), the process proceeds to step S83. If it is determined that there is no unused spare area block (step S82: NO), the CPU 11 The writing is terminated as an abnormal end.

  In step S83, the CPU 11 stores the physical block number Nx (which may be a physical address) of the unused spare area block determined in step S82 in, for example, the RAM 12 and holds it.

  Next, the CPU 11 refers to data in the spare area management block referred to in step S1 (hereinafter referred to as “management block data”, spare area management block identifier ID, use counter C, spare block physical block number Nx, and error. The inspection information P) is read into the RAM 12, and write data for the spare area management block is constructed (step S84). For example, the usage counter C included in the read management block data is incremented by 1 on the RAM 12. Furthermore, instead of deleting the physical block number Nx of the spare area block in which the update data Dz is written out of the physical block number Nx included in the read management block data on the RAM 12, the block is replaced in step S5. The physical block number Nx of the data storage area block (new spare area block) from which data has been read is stored. Thereby, the physical block number Nx of the spare area block in the RAM 12 is the physical block number Nx of the spare area block in which the update data Dz is not written among the physical block numbers Nx of the read spare area block, and step S5. The data is reconstructed with the physical block number Nx of the data storage area block from which the block data is read out. Based on these data, the spare area management block identifier ID included in the read block data, the counter C incremented by 1, the physical block number Nx of the reconstructed spare area block, for example, CRC calculation is performed. Write data for the spare area management block is constructed based on the error check information P calculated by the equation.

  Next, the CPU 11 writes the write data for the spare area management block constructed in step S84 into the spare area block corresponding to the physical block number Nx held in step S83 (step S85), and performs the processing shown in FIG. Return. That is, the write data for the spare area management block constructed in step S84 is written in the spare area block as the spare area management block searched in step S81 as a new spare area management block.

  Next, in the rollback process shown in FIG. 5, the CPU 11 first determines whether there are two or more spare area management blocks (step S111). When the CPU 11 determines that there are two or more spare area management blocks (step S111: YES), the CPU 11 proceeds to step S112, and when it is determined that two or more spare area management blocks do not exist (step S111: NO). The process proceeds to step S115.

  In step S112, the CPU 11 determines whether or not the error check information P stored in the newest spare area management block is normal. For example, if the error check information P stored in the newest spare area management block matches the error check information P calculated at this time, it is determined to be normal. When the CPU 11 determines that the error check information P stored in the spare area management block is normal (step S112: YES), the CPU 11 corresponds to the physical block number Nx stored in the newest spare area management block. The spare area block to be initialized is initialized (step S113), and the rollback process is terminated. On the other hand, when the CPU 11 determines that the error check information P stored in the spare area management block is not normal (step S112: NO), the old spare area management block (that is, spare area management other than the spare area management block most). The spare area block corresponding to the physical block number Nx stored in the block) is initialized (step S114), and the rollback process is terminated.

  On the other hand, in step S115, the CPU 11 determines whether or not the spare area block corresponding to the physical block number Nx stored in the spare area management block determined in step S111 is unused. When the CPU 11 determines that the spare area block corresponding to the physical block number Nx stored in the spare area management block is unused (that is, the initialized value is held) (step S115). : YES), the rollback process is terminated. On the other hand, when the CPU 11 determines that the spare area block corresponding to the physical block number Nx stored in the spare area management block is not unused (step S115: NO), the physical stored in the spare area management block. The spare area block corresponding to the block number Nx is initialized (step S116), and the rollback process is terminated.

  As described above, according to the above embodiment, the logical block number Ny is held in the data storage area block, and the logical block number Nx of the spare area block is held in the spare area management block. When performing a search, a spare area block is searched with reference to the spare area management block, and after writing the write data into the spare area block with the searched spare area block as a new data storage area block, the stale data Since the configuration is such that the physical block number Nx of the storage area block is written to the spare area management block as the physical block number Nx of the new spare area block, writing that guarantees data by only writing two blocks in one writing process is realized. Can improve the writing process speed. .

1 IC card 1a IC chip 11 CPU
12 RAM
13 Flash memory 14 I / O circuit

Claims (6)

A non-volatile memory having a storage area divided into a plurality of blocks including a data storage area block, a spare area block, and a spare area management block, and each block having a physical block number forming a physical address space And a controller that reads and writes data to and from the nonvolatile memory in response to a command, an information recording medium comprising:
The data storage area block stores data and logical block numbers forming a logical address space, the spare area block stores an initialized value, and the spare area management block stores the spare area block. The physical block number is stored,
The controller is
A first search means for searching for the spare area block with reference to the spare area management block when performing a data write process in response to the command;
Second search means for searching for the data storage area block storing the logical block number calculated in response to the command;
The spare area block searched by the first search means as the new data storage area block in the spare area block, and the data stored in the data storage area block searched by the second search means First writing means for writing corresponding update data and the logical block number calculated in response to the command;
Using the physical block number of the data storage area block retrieved by the second retrieval means as the physical block number of a new spare area block, the spare area management block after writing the update data by the first writing means Second writing means for writing to
An information recording medium comprising: In the data storage area block, a usage counter indicating the number of times the data storage area block is used is stored.
The first writing means sets the use counter stored in the data storage area block searched by the second searching means when writing the update data and the logical block number to the spare area block. 2. The information recording medium according to claim 1, wherein a use counter incremented by 1 is written in the spare area block.   The second writing means sets the spare area block in which the update data has not been written by the first writing means among the plurality of spare area blocks searched by the first searching means to the new spare area. In the spare area block as the management block, the physical block number of the new spare area block, the new data storage area block, and the new spare area block not used as the spare area management block The information recording medium according to claim 1, wherein a physical block number is written. Error information is further stored in the spare area management block,
The controller is
Whether or not there are two or more spare area management blocks if the spare area block retrieved by the first retrieval means is not unused, or if the writing by the second writing means does not end normally. First determination means for determining;
Second determination means for determining whether or not error check information stored in the newest spare area management block is normal when the first determination means determines that there are two or more spare area management blocks; ,
When it is determined by the second determination means that the error check information stored in the spare area management block is normal, the spare area corresponding to the physical block number stored most in the spare area management block While the block is initialized, the error determination information stored in the spare area management block is determined to be not normal by the second determination unit, and stored in the spare area management block other than the spare area management block. Initialization means for initializing the spare area block corresponding to the physical block number being
The information recording medium according to any one of claims 1 to 3, further comprising: A non-volatile memory having a storage area divided into a plurality of blocks including a data storage area block, a spare area block, and a spare area management block, and each block having a physical block number forming a physical address space A data read / write method performed by the controller in an information recording medium comprising: a controller that reads and writes data to and from the nonvolatile memory in response to a command;
The data storage area block stores data and logical block numbers forming a logical address space, the spare area block stores an initialized value, and the spare area management block stores the spare area block. The physical block number is stored,
The data read / write method is:
A first search step of searching for the spare area block with reference to the spare area management block when performing a data write process in response to the command;
A second search step of searching for the data storage area block storing the logical block number calculated in response to the command;
The spare area block searched in the first search step is used as the new data storage area block in the spare area block, and the data stored in the data storage area block searched in the second search step A first writing step of writing corresponding update data and the logical block number calculated in response to the command;
The spare area management block after writing the updated data in the first writing step, with the physical block number of the data storage area block searched in the second searching step as the physical block number of a new spare area block A second writing step for writing to
A method for reading and writing data, comprising: A non-volatile memory having a storage area divided into a plurality of blocks including a data storage area block, a spare area block, and a spare area management block, and each block having a physical block number forming a physical address space A data read / write program executed by the controller in an information recording medium comprising: a controller that reads and writes data to and from the nonvolatile memory in response to a command;
The data storage area block stores data and logical block numbers forming a logical address space, the spare area block stores an initialized value, and the spare area management block stores the spare area block. The physical block number is stored,
In the controller,
A first search means for searching for the spare area block with reference to the spare area management block when performing a data write process in response to the command;
Second search means for searching for the data storage area block storing the logical block number calculated in response to the command, and the spare area block searched by the first search means for newly storing the data Update data corresponding to the data stored in the data storage area block searched by the second search means in the spare area block as the area block, and the logical block number calculated in response to the command First writing means for writing, and
Using the physical block number of the data storage area block retrieved by the second retrieval means as the physical block number of a new spare area block, the spare area management block after writing the update data by the first writing means A data read / write program which functions as a second writing means for writing to the data.

Images