JP3641863B2 - Data recording apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present inventionData recording apparatus and methodIn particular, the management information for managing the data recorded in the data recording medium can be quickly identified as to whether or not the management information is correct.Data recording apparatus and methodAbout.
[0002]
[Prior art]
Recently, with the spread of computers, various data have been recorded and used on data recording media such as magnetic disks, magneto-optical disks, and IC memory cards.
[0003]
FIG. 15 shows a configuration example of a file system of MD (mini disk) (trademark) data which is a kind of magneto-optical disk. As shown in the figure, the MD data disk is divided into 2252 clusters, 83 areas of cluster 0 to cluster 82 are UTOC and alternate cluster areas, and cluster 83 to cluster 114 are volume management areas. (Volume Management Area (VMA)). The clusters 115 to 2251 are used as file extent areas (FEA) for recording data.
[0004]
Clusters 3 to 5 in the UTOC and the alternate cluster area are UTOC (User Table of Content) areas, and clusters 50 to 82 are alternate cluster areas. Other clusters are reserved.
[0005]
In the first cluster 83 of the volume management area (VMA), a volume descriptor (Volume Descriptor (VD)) is arranged in the first sector, and in the next three sectors, a volume space bitmap (VSB) is arranged. )) Is arranged, a management table (MT) is arranged in the following two sectors, and a directory record block (Directory Record Block (DRB)) is arranged in the following 26 sectors.
[0006]
One cluster is composed of 32 sectors, and one sector is 2048 bytes. Therefore, one cluster is 65536 bytes (64 kbytes).
[0007]
As shown in FIG. 16, the volume descriptor (VD) is the position of the volume space bitmap (VSB), management table (MT), directory record block (DRB), and file extent area (FEA) recorded on this disc. Represents.
[0008]
The volume space bitmap (VSB) has bitmap data for managing the free area of the file extent area (FEA). The management table (MT) manages the empty space of the directory record block (DRB). The directory record block (DRB) is an area for managing files and directories. One DRB is described in one sector.
[0009]
FIG. 17 schematically shows the format of the volume management area (VMA). As shown in the figure, the first sector of the cluster 83 has a volume descriptor (VD), the next three sectors have a volume space bitmap (VSB), and the next two sectors have a management table (MT). , Each is arranged. Then, directory record blocks (DRB) 6 to DRB 1023 are arranged in each sector of the cluster 83 and subsequent sectors and in each sector of the cluster 84 to cluster 114.
[0010]
FIG. 18 shows an example of processing in a conventional MD data recording / reproducing apparatus.
[0011]
First, in step S91, the volume descriptor (VD), volume space bitmap (VSB), and management table (MT) are read from the disk (MD data) and written to the RAM (not shown) of the data recording / reproducing apparatus. . Next, in step S92, the process waits until a recording, reproduction, or erasing command is input.
[0012]
When a command for recording, reproduction or erasure is input, the process proceeds to step S93, S94 or S95, respectively, and recording processing, reproduction processing or erasure processing corresponding to the command is executed. That is, data is recorded, reproduced, or deleted from the file extent area (FEA) of the disc.
[0013]
Next, in step S96, it is determined whether or not the operation has been instructed by inputting a power-off command or a command to eject the disc. If the termination is not instructed, the process returns to step S92 and the subsequent processing is repeatedly executed.
[0014]
If it is determined in step S96 that termination has been instructed, the process proceeds to step S97, and the contents of the volume descriptor (VD), volume space bitmap (VSB), and management table (MT) stored in the RAM are updated. If so, it is written to disk.
[0015]
In this way, when data is recorded in the file extent area (FEA) or the recorded data is deleted, the contents of the volume management area (VMA) are updated accordingly. Referring to the contents of the volume management area (VMA), any file recorded in the file extent area (FEA) can be freely accessed.
[0016]
However, if the contents of the volume management area (VMA) are all stored in the RAM in this way and the operation is terminated, the contents are finally written to the disk, and the capacity of the RAM must be increased. Not only is the cost high, but the time until the operation is actually ended after the end is instructed becomes longer, and the operability is deteriorated.
[0017]
Therefore, every time the contents of the volume management area (VMA) are changed, the contents may be recorded on the disc. However, doing so would reduce the processing speed during use.
[0018]
In order to solve this, the volume descriptor (VD), the volume space bitmap (VSB), and the management table (MT) are made resident in the RAM, and the directory record block (DRB) is frequently accessed on the RAM. When a new directory record block (DRB) is accessed, the old directory record block (DRB) is written on the disk, and the new directory record block (DRB) is fetched into the RAM. An (LRU) algorithm may be used.
[0019]
However, if this is done, information that has not yet been written to the disk will remain on the RAM, and more frequently used information may be resident in the RAM, resulting in not being written to the disk. Increases nature.
[0020]
As a result, a system error occurs when the data recording / reproducing device stops (system goes down) when the above-mentioned file system operation procedure is not completed due to device failure, power failure, operation error, etc. To do.
[0021]
For example, assuming that a system down occurs at a timing when a predetermined file A is registered in the directory record block (DRB) 32 and its contents data is written in the file extent area (FEA), a volume space bitmap (VSB) Has not yet been updated, the area in which the file A in the file extent area (FEA) is recorded will be regarded as an empty area during subsequent access. As a result, when a new file B is next recorded, the file B is overwritten in the area where the file A is recorded, and the file A is erased.
[0022]
Further, for example, in the directory record block (DRB) 6 of the parent directory, the subdirectory C is registered as the directory record block (DRB) 64 and the directory record block (DRB) 64 is not yet updated. When the system goes down, the subdirectory C does not actually exist. As a result, reading subdirectory C results in a system error.
[0023]
[Problems to be solved by the invention]
Thus, if there is an abnormality in the file management information of the disk, it becomes difficult to accurately hold the file (data). Therefore, it is checked whether or not there is an abnormality in the file management information of the disk, and if an abnormality is found, it is repaired.
[0024]
Inspecting whether there is an abnormality in the file management information of the disk is performed by, for example, inspecting the following items.
[0025]
(1) Whether or not subdirectories registered in each directory actually exist.
[0026]
(2) Whether a volume space bitmap (VSB) is in use for the recording area of each file registered in each directory.
[0027]
(3) Whether there is any other self-contradiction in file management information.
[0028]
These inspections require several minutes. Therefore, for example, this inspection can be performed when the power source of the data recording / reproducing apparatus is turned on or when a disk is loaded in the data recording / reproducing apparatus. However, in such a case, it takes too much time to actually use the data recording / reproducing apparatus, and the operability is impaired.
[0029]
Therefore, when an abnormality is recognized in the operation of the apparatus, it can be inspected. However, if this is done, anomalies will be discovered after important data is destroyed, and reliability will be impaired.
[0030]
The present invention has been made in view of such a situation, and makes it possible to detect whether or not the data management information on the recording medium is correct quickly and reliably.
[0031]
[Means for Solving the Problems]
  The data recording apparatus according to claim 1 is a first recording means for recording, on the recording medium, a first identification code representing a state before the data is rewritten before rewriting the data recorded on the recording medium. And rewriting means for rewriting data recorded on the recording medium after recording the first identification code, and rewriting the data on the first identification code recorded on the recording medium after rewriting data by the rewriting means. A second recording means for rewriting the second identification code representing the state after the recording, and a third identification code representing the state before the first identification code is recorded on the recording medium.On storage mediaThe third recording means for recording and the state after the first identification code is recorded after the first identification code is recorded on the recording medium by the first recording means. Fourth recording means for rewriting to a fourth identification code representingReproducing means for reproducing data from a recording medium;The first recording means records the first identification code on the recording medium when data rewriting to the recording medium is instructed and the third identification code is recorded.The reproducing means reproduces data from the recording medium without detecting whether or not the third identification code is recorded when the reproduction of the data recorded on the recording medium is instructed.It is characterized by that.
[0032]
  Claim6In the data recording method described in 1), before rewriting data to be recorded on the recording medium, a first recording step for recording on the recording medium a first identification code representing a state before the data is rewritten, A rewriting step of rewriting data recorded on the recording medium after recording of one identification code, and a state after rewriting the data of the first identification code recorded on the recording medium after rewriting of data. A second recording step for rewriting to a second identification code representing that, and a third identification code representing a state before the first identification code is recorded on the recording medium.On storage mediaA third recording step for recording, a fourth identification representing a state after the first identification code is recorded, after the first identification code is recorded on the recording medium. A fourth recording step for rewriting the identification code;A reproduction step of reproducing data from the recording medium;And the first recording step records the first identification code on the recording medium when the data rewriting to the recording medium is instructed and the third identification code is recorded.The reproduction step reproduces data from the recording medium without detecting whether or not the third identification code is recorded when the reproduction of the data recorded on the recording medium is instructed.It is characterized by that.
[0034]
  Data according to claim 1Recording deviceIn the first recording means, before rewriting the data recorded on the recording medium, the first recording code is recorded on the recording medium to indicate the state before the data is rewritten. After recording the identification code of 1, the data recorded on the recording medium is rewritten, and the second recording means replaces the data with the first identification code recorded on the recording medium after rewriting the data by the rewriting means. The third identification code is rewritten to the second identification code representing the state after the rewriting, and the third recording means represents the state before the first identification code is recorded on the recording medium. TheOn storage mediaThe fourth recording means records the third identification code after the first identification code is recorded on the recording medium by the first recording means in the state after the first identification code is recorded. Rewrite to the fourth identification code to indicate that there isThe reproduction means reproduces data from the recording medium. The first recording means records the first identification code on the recording medium when the data rewriting to the recording medium is instructed and the third identification code is recorded, and the reproducing means When the reproduction of the data recorded in is instructed, the data is reproduced from the recording medium without detecting whether or not the third identification code is recorded.
[0035]
  Claim6In the data recording method described in 1), before rewriting the data recorded on the recording medium, the first identification code indicating the state before the data is rewritten is recorded on the recording medium. After recording, the data recorded on the recording medium is rewritten, and after the data is rewritten, the first identification code recorded on the recording medium is changed to the second identification code indicating the state after the data is rewritten. And a third identification code indicating that the first identification code is in a state before being recorded on the recording medium.On storage mediaAfter the recording and the first identification code are recorded on the recording medium, the third identification code is rewritten to a fourth identification code indicating the state after the first identification code is recorded.The data is reproduced from the recording medium. In addition, when the data rewriting to the recording medium is instructed and the third identification code is recorded, the first identification code is recorded on the recording medium and the reproduction of the data recorded on the recording medium is instructed. At this time, data is reproduced from the recording medium without detecting whether or not the third identification code is recorded.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing a configuration example of a data recording / reproducing apparatus of the present invention. The data recording medium 1 is a recording medium made of, for example, a magnetic disk, a magneto-optical disk, an IC memory card, etc., and records data. The medium driving unit 2 records data on the data recording medium 1 and reproduces the data. For example, when the data recording medium 1 is a magneto-optical disk, a spindle motor that rotates the disk, The disk drive device includes an optical pickup that irradiates a magneto-optical disk with laser light, a servo circuit that performs various servo operations, a modulation / demodulation circuit that modulates a recording signal and demodulates a reproduction signal.
[0038]
The RAM 3 functions as a buffer when data is recorded / reproduced with respect to the data recording medium 1 and also as a work area for appropriately storing necessary data and programs when the CPU 5 executes various operations. . The nonvolatile memory 4 stores data that needs to be stored even after the power of the data recording / reproducing apparatus is turned off. The CPU 5 executes various processes according to programs stored in the ROM 6.
[0039]
The data input unit 7 is used to input various data and includes a keyboard, a digital interface, an A / D converter, and the like. The data output unit 8 is a part that outputs data, and is configured by, for example, a digital interface, a CRT display, a D / A converter, and the like.
[0040]
In the following embodiments, the data recording medium 1 is assumed to be MD data.
[0041]
FIG. 2 shows a format of MD data as the data recording medium 1. This format is basically the same as the format of the conventional MD data described with reference to FIG. 15, but in this embodiment, the volume descriptor (in the volume management area (VMA)) arranged in the cluster 83 ( An error detection byte (Fault Detect Byte (FDB)) is arranged in an unused byte of (VD). Other configurations are the same as those in FIG.
[0042]
The abnormality detection byte (FDB) is defined as normal if the value is 0, and abnormal if the value is 0x42. Here, 0x represents a hexadecimal number.
[0043]
This abnormality detection byte (FDB) is recorded as shown in the flowchart of FIG. That is, when the user operates the data input unit 7 to instruct data recording, the CPU 5 controls the medium driving unit 2 in step S1 (first recording means) to serve as the data recording medium 1. 0x42 (first identification code) is written in the abnormality detection byte (FDB) in the volume descriptor (VD) of the MD data.
[0044]
  Next, step S2 (RewriteThe CPU 5 temporarily stores the recording data input from the data input unit 7 in the RAM 3. Then, the data stored in the RAM 3 is read out, supplied to the data recording medium 1 via the medium driving unit 2, and recorded in the file extent area (FEA). As the data is recorded, the management information in the volume management area (VMA) is also updated.
[0045]
  And step S3 (the first2The CPU 5 rewrites the abnormality detection byte (FDB) in the disk (MD data) in which 0x42 is written in step S1 to 0 (second identification code).
[0046]
As described above, according to this embodiment, 0x42 is written to the abnormality detection byte (FDB) before writing data to the MD data, and the value is rewritten to 0 after the data writing is completed. When a system failure occurs during the rewriting process, the abnormality detection byte (FDB) of MD data remains 0x42.
[0047]
On the other hand, the contents of the disc are normal even if a system failure occurs before data writing or after rewriting is completed. At this time, the value of the abnormality detection byte (FDB) is zero.
[0048]
Therefore, when a disk is loaded in the data recording / reproducing apparatus or when the data recording / reproducing apparatus is turned on, the abnormality detection byte (FDB) of the MD data is read. If the value is 0x42, a repair program for repairing the contents of the disk is executed.
[0049]
However, according to the embodiment of FIG. 3, every time data on the disk is rewritten, processing for rewriting the abnormality detection byte (FDB) (processing of steps S1 and S3) has to be performed, and the processing speed decreases. Therefore, for example, processing can be performed as shown in the flowchart of FIG.
[0050]
In the process of FIG. 4, first, in step S11 (reproducing means), the CPU 5 reads the volume descriptor (VD), volume space bitmap (VSB), and management table (MT) from the data recording medium 1 (MD data). , It is stored in the RAM 3. Next, in step S12, the abnormality detection byte (FDB) in the volume descriptor (VD) just read is read to determine whether or not the value is 0x42.
[0051]
As will be described later, also in this embodiment, when a system down occurs during the data recording operation, the abnormality detection byte (FDB) is 0x42. Therefore, in this case, it is determined that the content of the data is not normal, and the process proceeds to step S13 (restoring means) to execute the repair program. Thereby, the abnormality in the data recording medium 1 is repaired. That is, the sub-directory registered in the directory actually exists, the volume space bitmap (VSB) is being used for the recording area of each file registered in each directory, and other management information Restoration is performed so that there is no self-contradiction.
[0052]
Since such repair has been performed, the process proceeds to step S14, and the value of the abnormality detection byte (FDB) in the volume descriptor (VD) on the RAM 3 is rewritten to 0. In step S15, the volume descriptor (VD), volume space bitmap (VSB), and management table (MT) stored in the RAM 3 are written in the data recording medium 1 (the contents of the MD data are updated). As a result, 0 is recorded as the value of the abnormality detection byte (FDB) in the volume descriptor (VD) of the MD data.
[0053]
Therefore, returning to step S11, the volume descriptor (VD), the volume space bitmap (VSB), and the management table (MT) are read from the MD data again and written to the RAM 3, and then the abnormality detection byte (FDB) written to the RAM 3 is read. The value of is 0. Therefore, in this case, NO is determined in step S12, and the process proceeds to step S16.
[0054]
In step S16, the value of the abnormality detection byte (FDB) stored in the RAM 3 is rewritten from 0 to 0x42. In step S17, the volume descriptor (VD), volume space bitmap (VSB), and management table (MT) stored in the RAM 3 are read and written to the MD data.
[0055]
The processing of FIG. 4 is performed when the data recording medium 1 is mounted on the data recording / reproducing apparatus, or when the data recording medium 1 is already mounted on the data recording / reproducing apparatus. Started when turned on. That is, it is executed when the use of the data recording / reproducing apparatus is started.
[0056]
Therefore, the data recording medium 1 is always in a normal state before the substantial use for the data recording medium 1 is started. Further, in this state, the value of the abnormality detection byte (FDB) of the data recording medium 1 is set to 0x42 in case the system goes down halfway thereafter.
[0057]
Next, in step S18, the CPU 5 stands by until a predetermined operation command is input from the data input unit 7. When the recording is instructed, the process proceeds to step S19 to execute the recording process and the reproduction is instructed. In step S20, the reproduction process is executed. When the deletion is instructed, the process advances to step S21 and the deletion process is executed.
[0058]
FIG. 5 shows details of the recording process. First, in step S111, the CPU 5 scans the volume space bitmap (VSB) stored in the RAM 3 and searches for the number of empty sectors necessary for recording data. In step S112, data is recorded in the empty sector searched in step S111.
[0059]
In the case of MD data, recording is performed in cluster units. Therefore, when data has already been recorded in another sector of the cluster to which the empty sector to which data is to be newly recorded belongs, the data in that sector is read and stored in the RAM 3. Then, the recording data input from the data input unit 7 is written in the empty sector of the cluster in the RAM 3. Then, after the data for one cluster is collected, the data for the one cluster is read from the RAM 3 and written to the cluster in the corresponding file extent area (FEA) of the MD data via the medium driving unit 2.
[0060]
In step S113, the CPU 5 sets the bit corresponding to the empty sector in which data is recorded in the volume space bitmap (VSB) stored in the RAM 3 to be used.
[0061]
In step S114, the directory record block (DRB) corresponding to the sector in which the data is recorded is read from the data recording medium 1 and stored in the RAM 3. In step S115, the file name of the file composed of the data recorded in step S112, the number of the first sector in which the data is recorded, and the number of sectors in which the data is recorded are stored in the directory record block (DRB) just read. Are recorded in the MD data.
[0062]
FIG. 6 shows details of the reproduction process. In the reproduction process, in step S121, the CPU 5 reads the directory record block (DRB) recorded on the data recording medium 1 into the RAM 3 and scans it, and searches for the file name to be reproduced input from the data input unit 7. To do. When the directory record block (DRB) having the target file name is searched, the process proceeds to step S122, and the start sector number and the number of sectors of the file are read from the directory record block (DRB). In step S123, the CPU 5 reproduces the same number of sectors as read from the start sector number read in step S122.
[0063]
The reproduction data is stored in the RAM 3 and then read out again and output to the data output unit 8.
[0064]
FIG. 7 shows the details of the erasure process. In the erasure process, in step S141, the directory record block (DRB) of the data recording medium 1 is read into the RAM and scanned, and a directory record block (DRB) having a file name to be erased is searched. When the directory record block (DRB) having the target file name is searched, the process proceeds to step S142, and the start sector number and the number of sectors of the directory record block (DRB) are read.
[0065]
Next, proceeding to step S143, the CPU 5 clears the corresponding bit on the volume space bitmap (VSB) of the number of sectors constituting the file from the sector of the start sector number read at step S142. This volume space bitmap (VSB) is stored in the RAM 3. In step S144, the description of the file in the directory record block (DRB) in the data recording medium 1 is deleted.
[0066]
Returning to FIG. 4, as described above, after the recording process, the reproduction process, or the erasing process is executed in steps S19 to S21, the process proceeds to step S22 to determine whether or not the end of the process is instructed. . If the end is not instructed by inputting the data recording medium 1 from the data input unit 7 or a command to turn off the power of the data recording / reproducing apparatus, the process returns to step S18, and the subsequent processing is performed. Run repeatedly.
[0067]
If it is determined that the end of the process has been commanded, the process proceeds to step S23, and the CPU 5 rewrites the abnormality detection byte (FDB) in the RAM 3 to zero. This abnormality detection byte (FDB) has been rewritten to 0x42 in step S16 at the start of processing. In step S24, the volume descriptor (VD), volume space bitmap (VSB), and management table (MT) stored in the RAM 3 are written in the data recording medium 1. Further, in step S25, in response to the end command, a process of turning off the power or ejecting the disc is executed.
[0068]
As described above, according to the embodiment of FIG. 4, the processing speed is only rewritten once each time the abnormality detection byte (FDB) is rewritten before and after the substantial use state of steps S18 to S22. The decrease in is suppressed.
[0069]
However, in the embodiment shown in FIG. 4, the abnormality detection byte (FDB) writing process is executed not only when data is written to the disk but also when data is simply reproduced. Therefore, when only the reproduction process that does not perform the data recording operation on the data recording medium 1 is performed, it is possible not to update the abnormality detection byte (FDB) of the data recording medium 1. . FIG. 8 shows an embodiment in this case.
[0070]
In FIG. 8, first, in step S41, the volume descriptor (VD), the volume space bitmap (VSB), and the management table (MT) are read from the data recording medium 1 and stored in the RAM 3. In step S42, it is determined whether or not the abnormality detection byte (FDB) in the read volume descriptor (VD) is 0x42. When the abnormality detection byte (FDB) is 0x42, the process proceeds to step S43, and the repair program is executed. After the restoration process is executed, in step S44, the abnormality detection byte (FDB) of the RAM 3 is rewritten to 0, and the volume descriptor (VD), volume space bitmap (VSB), and management table stored in the RAM 3 are stored. (MT) is written to the data recording medium 1 in step S45. The above process is the same as the process of steps S11 to S15 in FIG.
[0071]
  In step S42, when it is determined that the abnormality detection byte (FDB) read into the RAM 3 is not 0x42 (when it is determined to be 0),In step S46Then, the CPU 5 rewrites the value of the abnormality detection byte (FDB) in the RAM 3 from 0 to 0x42. Further, the inspection byte (FDS) (third identification code) stored in the RAM 3 (or the nonvolatile memory 4) is set to 0. This inspection byte (FDS) functions as an identification code indicating whether or not data has been written to the data recording medium 1. Here, the value 0 is initially set on the assumption that no data is written in the data recording medium 1.
[0072]
Next, it progresses to step S47 and waits until a predetermined instruction | command is input from the data input part 7. FIG.
[0073]
When the data recording is instructed, the process proceeds to step S48, and the CPU 5 determines whether or not the inspection byte (FDS) stored in the RAM 3 (or the nonvolatile memory 4) is zero. In the case where data has not been written to the data recording medium 1 yet, as described above, 0 is initially set in the inspection byte (FDS) in step S46. In this case, the process proceeds to step S49, and the volume descriptor (VD), volume space bitmap (VSB), and management table (MT) stored in the RAM 3 are written into the data recording medium 1. Therefore, the abnormality detection byte (FDB) of the data recording medium 1 is set to 0x42.
[0074]
In step S50, the CPU 5 rewrites the value of the check byte (FDS) stored in the RAM 3 to 1. Thereby, it is set that the recording process has been performed on the data recording medium 1 (performed in the subsequent step S51). In step S 51, the data input from the data input unit 7 and stored in the RAM 3 is recorded in the file extent area (FEA) of the data recording medium 1. The details of the recording process in step S51 are the same as those shown in FIG.
[0075]
If it is determined in step S48 that the inspection byte (FDS) is not 0 (is 1), the data writing process has been executed once or more for the data recording medium 1. In this case, since the abnormality detection byte (FDB) of the data recording medium 1 has already been rewritten to 0x42, the processing of steps S49 and S50 is skipped, and the processing proceeds to step S51 and the recording processing is immediately started.
[0076]
On the other hand, when data erasure is instructed in step S47, the data recording medium 1 is written in this case as well, so the same processing as in the recording is executed. That is, in this case, it is determined in step S53 whether or not the check byte (FDS) stored in the RAM 3 is 0. If it is 0, the process proceeds to step S54, and the volume descriptor stored in the RAM 3 is determined. (VD), volume space bitmap (VSB), and management table (MT) are written to the data recording medium 1. In step S55, the inspection byte (FDS) stored in the RAM 3 is set to 1. Thereafter, the process proceeds to step S56, and an erasing process is executed. The details of the erasing process are the same as those shown in FIG.
[0077]
If it is determined in step S53 that the inspection byte (FDS) is not 0 (1), the data recording medium 1 has already been subjected to data writing processing one or more times. Therefore, in this case, the abnormality detection byte (FDB) has already been rewritten to a value of 0x42. For this reason, the processes of steps S54 and 55 are skipped, and the erasure process of step S56 is immediately executed.
[0078]
Furthermore, when a reproduction command is input in step S47, the process proceeds to step S52, and reproduction processing is executed. The details of this reproduction process are the same as those shown in FIG.
[0079]
That is, when reproduction is instructed, unlike the case where recording or erasure is instructed, the process of updating the abnormality detection byte (FDB) of the data recording medium 1 is not performed.
[0080]
After step S51, S52 or S56, the process proceeds to step S57, where it is determined whether or not the end of the process has been commanded. If not, the process returns to step S47 and the subsequent processes are repeatedly executed.
[0081]
If it is determined that the end of the process has been commanded, the process proceeds to step S58, where it is determined whether or not the check byte (FDS) is 1. As described above, when data is recorded even once on the data recording medium 1, the inspection byte (FDS) is set to 1 in step S50 or S55, and in the data recording medium 1 in step S49 or S54. The anomaly detection byte (FDB) is rewritten to a value of 0x42. Therefore, in step S59, the abnormality detection byte (FDB) in the volume descriptor (VD) of the RAM 3 is rewritten to 0. In step S60, a process of writing the volume descriptor (VD), volume space bitmap (VSB), and management table (MT) stored in the RAM 3 into the data recording medium 1 is executed.
[0082]
Further, the process proceeds to step S61, and a process of turning off the power or ejecting the disk is executed in response to the termination command.
[0083]
If it is determined in step S58 that the inspection byte (FDS) is not 1 (0), the data recording medium 1 is subjected to a data writing process (recording or erasing process) even if a reproduction process is performed. Has never been done. Therefore, the abnormality detection byte (FDB) of the data recording medium 1 is kept at 0. Therefore, the processes in steps S59 and S60 are skipped, and the process in step S61 is immediately executed.
[0084]
As described above, according to this embodiment, extra writing (writing of an abnormality detection byte (FDB)) is not performed on a disk that has never been written.
[0085]
The embodiment of FIG. 8 has the following effects. That is, when the power is turned on or the disk is inserted, the volume descriptor (VD) must be read, and the efficiency reduction due to the inspection of the abnormality detection byte (FDB) does not occur.
[0086]
In addition, when writing to the disk occurs, the volume space bitmap (VSB) and the volume descriptor (VD) are changed anyway, so that even if recording / reproduction of the abnormality detection byte (FDB) is not performed, The volume descriptor (VD), volume space bitmap (VSB), and management table (MT) are written. Therefore, when the writing process is performed on the disk, even if the abnormality detection byte (FDB) is recorded on the disk, the efficiency does not decrease due to that.
[0087]
That is, when the abnormality detection byte (FDB) is 0, the volume descriptor (VD), volume space bitmap (VSB), and management table (MT) are written when data is first recorded (in step S49 or S54). Only writing is an extra process compared to the case where the abnormality detection byte (FDB) is not adopted. Therefore, even if the abnormality detection byte (FDB) is adopted, the efficiency reduction caused by it can be almost ignored.
[0088]
Next, details of the repair program execution processing (step S13 in FIG. 4 or step S43 in FIG. 8) will be further described.
[0089]
In the MD data, when the data input unit 7 instructs the CPU 5 to set the mirror mode, the CPU 5 normally sets the volume management area (VMA) formed in the cluster 83 to the cluster 114 as shown in FIG. As shown in FIG. 9, the volume management area (VMA) is formed in the cluster 83 to the cluster 146 by enlarging it twice. Then, substantially the same information is written twice in the volume management area (VMA).
[0090]
That is, as shown in FIG. 9, each cluster is divided into the first half and the second half, and the same information is recorded in the first half and the second half. For example, in the first half of the cluster 83, a volume descriptor (VD), a volume space bitmap (VSB), a management table (MT), and directory record blocks (DRB) 6 to DRB15 are recorded. In the second half of the cluster 83, the same data as the first half is recorded. Also in the cluster 84, the data of the directory and record blocks DRB16 to DRB31 are written twice in the first half and the second half, respectively. The same applies to the clusters 85 to 146.
[0091]
When such a mirror mode is set, the CPU 5 executes, for example, the process shown in FIG. 10 in the repair program execution process of step S13 of FIG. 4 or step S43 of FIG.
[0092]
As described above, this processing is performed when the abnormality detection flag FDB is determined to be 0x42 in step S12 of FIG. 4 or step S42 of FIG. (Destroyed data) is recorded.
[0093]
Therefore, first in step S71, the CPU 5 determines whether or not the first half of the cluster (for example, cluster 83) can be read. As shown in FIG. 11, if the data in the latter half of the first half and the second half of the cluster 83 is destroyed, the first half data (updated new data) can be read. In this case, the process proceeds to step S72, and the first half volume descriptor (VD) of the cluster 83 is read.
[0094]
Then, it is determined in step S73 whether or not the abnormality detection byte (FDB) in the read volume descriptor (VD) is zero. If the anomaly detection byte (FDB) is 0, the rewriting of another cluster has already been completed, so that it can be determined that the data is normal. Therefore, in this case, the process proceeds to step S46 in FIG. 8 (or step S16 in FIG. 4), and the same process as in the normal case is executed.
[0095]
On the other hand, when it is determined that the abnormality detection byte (FDB) in the volume descriptor (VD) in the first half of the cluster 83 is not 0 (0x42), another cluster may have been rewritten. . Therefore, in this case, the process proceeds to step S74, and the repair program process is executed.
[0096]
On the other hand, when it is determined in step S71 that the first half data of the cluster 83 is not readable, the process proceeds to step S75, and it is determined whether the second half data of the cluster 83 is readable. For example, as shown in FIG. 12, even if the first half data of the cluster 83 is destroyed, the second half data (old data that has not been updated) may not be destroyed. In this case, the process proceeds to step S76, and the latter half of the cluster 83 is read. In step S77, it is determined whether or not the abnormality detection byte (FDB) in the read volume descriptor (VD) is zero.
[0097]
When the abnormality detection byte (FDB) of the old volume descriptor (VD) is 0, the other clusters are normal because they have not been rewritten yet. Therefore, the process proceeds to step S46 in FIG. 8 (or step S16 in FIG. 4), and the subsequent processing is executed.
[0098]
If it is determined in step S77 that the abnormality detection flag FDB is not 0 (0x42), there is a possibility that another cluster has been rewritten. In this case, the process proceeds to step S74, and the repair program process is executed. .
[0099]
As shown in FIG. 13, when the central part of the cluster 83 is destroyed, both the first half and the second half of the cluster 83 are unreadable. In this case, since NO is determined in step S71 and step S75, the process proceeds to step S74, and the repair program process is executed.
[0100]
Further, when the system goes down during writing of any one of the clusters 84 to 146 other than the cluster 83, as shown in FIG. 14, the first half (FIG. 14 (a)) and the second half (FIG. 14A) In FIG. 14 (b)) or the center (FIG. 14 (c)), the data is destroyed. In this case, the same processing as in the cluster 83 can be performed.
[0101]
Whether or not the data is destroyed can be detected from the fact that there is no synchronization signal synchronized with the data at the time of reproduction or an error is detected by an error correction code.
[0102]
In the above embodiment, the abnormality detection byte is recorded on the data recording medium 1. However, when the data recording medium 1 cannot be removed from the data recording / reproducing apparatus, it is written in the nonvolatile memory 4. You can also
[0103]
Also, the abnormality detection byte (FDB) does not need to use all 1 byte, and may be 1 bit if it is only necessary to determine whether or not there is an abnormality. Conversely, more bits can be used when performing more diverse consistency checks, such as file management information consistency and file data consistency, as well as whether there is an error. . Further, in this case, in addition to the abnormality detection code, a file name to be changed can be recorded.
[0104]
In the above embodiments, the data recording medium 1 is MD data. However, the present invention is applicable not only to magneto-optical disks other than MD data, but also to other data recording media such as magnetic disks and IC memory cards. Is possible.
[0105]
【The invention's effect】
  As described above, the data recording apparatus according to claim 1 and the claim6According to the data recording method described in 1), after recording the first identification code, the data recorded on the recording medium is rewritten, and after rewriting the data, the first identification code recorded on the recording medium is changed to the second identification code. To the identification code ofRecording the third identification code on the storage medium;After the first identification code is recorded on the recording medium, the third identification code is rewritten to the fourth identification code., Play data from recording mediaThus, the consistency of the data management information can be instantaneously determined from the identification code.
[0106]
As a result, even if the consistency determination is performed every time the data recording / reproducing apparatus is activated or the data recording medium is replaced, it is possible to suppress a reduction in work efficiency. Further, since it is possible to prevent the data recording / reproducing process from being performed on the data recording medium in a state where consistency is not achieved, it is possible to dramatically improve operability and reliability. Become.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration example of a data recording / reproducing apparatus of the present invention.
FIG. 2 is a diagram for explaining the format of the data recording medium 1 of FIG. 1;
FIG. 3 is a flowchart showing a first processing example of the embodiment of FIG. 1;
FIG. 4 is a flowchart showing a second processing example of the embodiment of FIG. 1;
FIG. 5 is a flowchart illustrating details of the recording process in step S19 of FIG.
FIG. 6 is a flowchart illustrating details of the reproduction process in step S20 of FIG.
FIG. 7 is a flowchart for explaining details of an erasing process in step S21 of FIG.
FIG. 8 is a flowchart showing a third processing example of the embodiment of FIG. 1;
FIG. 9 is a diagram illustrating a format in a mirror mode.
FIG. 10 is a flowchart illustrating details of processing in step S43 of FIG. 8 in the mirror mode.
FIG. 11 is a diagram showing a state in which the latter half of the cluster 83 is destroyed.
FIG. 12 is a diagram showing a state in which the first half of the cluster 83 is destroyed.
FIG. 13 is a diagram showing a state in which the central portion of the cluster 83 is destroyed.
FIG. 14 is a diagram showing a state in which clusters other than the cluster 83 are destroyed.
FIG. 15 is a diagram showing a format of conventional MD data.
FIG. 16 is a diagram illustrating the configuration of a volume management area.
FIG. 17 is a diagram for explaining the arrangement of data in clusters 83 to 114;
FIG. 18 is a flowchart showing a processing example of a conventional data recording / reproducing apparatus.
[Explanation of symbols]
1 Data recording media
2 Medium drive unit
3 RAM
4 Nonvolatile memory
5 CPU
6 ROM
7 Data input section
8 Data output section

Claims (10)

A first recording means for recording on the recording medium a first identification code representing a state before the data is rewritten before rewriting the data recorded on the recording medium;
Rewriting means for rewriting data recorded on the recording medium after recording the first identification code;
After the rewriting of the data by the rewriting means, a second recording for rewriting the first identification code recorded on the recording medium with a second identification code indicating the state after the data is rewritten. Means,
Third recording means for recording on the storage medium a third identification code indicating that the first identification code is in a state before being recorded on the recording medium;
After the first identification code is recorded on the recording medium by the first recording means, the third identification code is a state after the first identification code is recorded. A fourth recording means for rewriting the identification code of 4,
Playback means for playing back data from the recording medium ,
The first recording means records the first identification code on the recording medium when data rewriting to the recording medium is instructed and the third identification code is recorded ,
The reproduction means reproduces data from the recording medium without detecting whether the third identification code is recorded or not when reproduction of data recorded on the recording medium is instructed. A characteristic data recording device. The reproducing means reproduces the first or second identification code from the recording medium ;
The data recording apparatus according to claim 1, further comprising: a restoration unit that performs a restoration process of the recording medium in correspondence with the reproduced first or second identification code. When the second recording means is instructed to end the operation of the data recording apparatus and the fourth identification code is recorded, the second recording means stores the first identification code recorded on the recording medium, The data recording apparatus according to claim 1, wherein the data recording apparatus is rewritten with a second identification code. The data recording apparatus according to claim 1, wherein the rewriting unit records data on the recording medium. The data recording apparatus according to claim 1, wherein the rewriting unit erases data recorded on the recording medium. A first recording step of recording on the recording medium a first identification code representing a state before the data is rewritten before rewriting the data recorded on the recording medium;
A rewriting step of rewriting data recorded on the recording medium after the recording of the first identification code;
A second recording step of rewriting the first identification code recorded on the recording medium after the rewriting of the data to a second identification code representing a state after the rewriting of the data;
A third recording step of recording on the storage medium a third identification code indicating that the first identification code is in a state before being recorded on the recording medium;
After the first identification code is recorded on the recording medium, the third identification code is rewritten to a fourth identification code indicating a state after the first identification code is recorded. 4 recording steps;
A reproducing step of reproducing data from the recording medium ,
In the first recording step, when the data rewriting to the recording medium is instructed and the third identification code is recorded, the first identification code is recorded on the recording medium ,
The reproduction step reproduces data from the recording medium without detecting whether the third identification code is recorded or not when reproduction of data recorded on the recording medium is instructed. A characteristic data recording method. In the reproducing step, the first or second identification code is reproduced from the recording medium ,
The data recording method according to claim 6 , further comprising: a repairing step of performing a repairing process of the recording medium in correspondence with the first or second identification code reproduced by the reproducing step. In the second recording step, when the operation end of the data recording method is instructed and the fourth identification code is recorded, the first identification code recorded on the recording medium is The data recording method according to claim 6 , wherein the second identification code is rewritten. 7. The data recording method according to claim 6 , wherein the rewriting step records data on the recording medium. The data recording method according to claim 6 , wherein the rewriting step erases data recorded on the recording medium.

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