JP2728949B2 - Control method of optical disk subsystem - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an optical disc subsystem control technique, and more particularly, to an effect obtained by applying it to a system configuration in which an optical disc drive is shared by a plurality of optical disc controllers. Regarding a certain technology.

[Conventional technology]

For example, an optical disk subsystem using an optical disk having a much higher information recording density than a magnetic disk or the like as a medium has been used as an external storage device in an information processing system.

By the way, generally, the reliability of an optical disk as a recording medium is still lower than that of a magnetic disk or the like, and the probability of occurrence of an error is high.

For this reason, in the process of recording data on the optical disk, immediately after the write operation to the desired area, a read-after-write process for reading and verifying the data from the area is performed, and the data write quality is poor. If enough unit recording area (block) is detected,
By writing the same data again to the replacement block, the reliability of the data is ensured.

In this case, it is necessary to clarify the correspondence between the defective block and the replacement block. However, in the case of an optical disk, it is difficult to record the position information (pointer) of the replacement block corresponding to the defective disk itself. There is a need to perform a process of retrieving pointer information of a replacement block and relieving a defective block when a defective block is detected during data reproduction.

If the search for the pointer of such a replacement block is actually performed by accessing the replacement block area, the processing time will be increased.
As in the technology disclosed in Japanese Patent No. 3321, measures such as maintaining a correspondence table between a defective block and a replacement block in a semiconductor memory inside the control device and speeding up the search for pointer information of the replacement block are taken. Have been.

[Problems to be solved by the invention]

However, in the case of the above-mentioned prior art, when an optical disk drive is occupied by one control device, there is a certain effect, but a case where the optical disk drive is shared by a plurality of control devices is considered. Absent. That is, even when the correspondence information between the defective block and the replacement block is updated by the writing process from a certain control device, the correspondence information in the memory of the other control device remains as it was before. However, the defective block is accessed without recognizing the correct correspondence between the defective block and the replacement block, and there is a problem that the repair operation of the defective block by the replacement block is not performed accurately.

If the replacement block area is always accessed every time a defective block is detected in order to avoid this, there is no point in holding the correspondence table between the defective block and the replacement block in the memory in the control device.

Accordingly, an object of the present invention is to provide a control method for an optical disk system capable of accurately and efficiently performing a repair process using a replacement block of a defective block without performing redundant access to a replacement block group by a plurality of optical disk control devices. Is to provide.

The above and other objects and novel features of the present invention are as follows.
It will be apparent from the description of this specification and the accompanying drawings.

[Means for solving the problem]

The outline of a typical invention disclosed in the present application is briefly described as follows.

That is, the control method of the optical disk subsystem according to the present invention includes a plurality of blocks each having a unique address.
An optical disc adapted to be used as a normal user block and a replacement block for relieving a writing defect in the user block, an optical disc drive for recording, reproducing, and erasing data on the optical disc;
An optical disk subsystem including a plurality of optical disk control devices for sharing and controlling the optical disk drive device, wherein a part of the optical disk drive device has first information indicating a correspondence between a defective user block and a replacement block. And storage means for storing second information indicating whether or not the first information has been updated, and each optical disk control device determines whether the first information is valid or invalid based on the second information. Thus, overlapping access to the replacement block group by a plurality of optical disk control devices for updating the first information is avoided.

[Action]

According to the control method of the optical disk subsystem of the present invention described above, for example, when an arbitrary optical disk control device accesses the optical disk drive, the first information is determined to be invalid by referring to the second information. In this case, the first information indicating the correspondence between the defective block and the replacement block is written into the storage means by directly accessing the replacement block area, and the first information is valid as the second information. Set again as shown.

Thus, the other optical disc control device can know that the first information is valid based on the second information, so that the other optical disc control device may not overlap the spare block area for the purpose of newly creating the first information. It is no longer necessary to perform a restricted access.

When the first information is changed by execution of the write process by an arbitrary optical disk control device, after completion of the write process, the first optical information is transmitted to another optical disk control device by means such as an interrupt process or a flag. By notifying that the information has changed, all the optical disk control devices can always access the optical disk of the optical disk drive using the correct first information.

As a result, it is possible to accurately and quickly perform the data write and read processing including the rescue processing using the replacement block of the defective block.

Embodiment 1 Hereinafter, an example of a control method of an optical disk subsystem according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an example of the configuration of an optical disk subsystem according to the present embodiment. FIGS. 2 and 3 are explanatory views showing an example of the main part of the optical disk subsystem, and FIGS. FIG. 8 is a flowchart showing an example of the control operation, and FIGS. 8 and 9 are explanatory diagrams showing an example of a format on the optical disc of the present embodiment.

First, an example of the configuration of the optical disk subsystem of the present embodiment will be described with reference to FIG.

An optical disk 5 as a storage medium is removably mounted on the optical disk drive device 3. Data is written, read, and erased from the optical disk 5 rotating at a predetermined speed via an optical head (not shown). The operation is performed.

As shown in FIG. 8, for example, the optical disk 5 has a plurality of tracks 0 to N arranged in a spiral shape, and each track has a predetermined number of sectors 0 to n-1 in the circumferential direction. It is divided into sectors. Recording, reproduction, erasure, and the like of data on the optical disk 5 are performed in units of individual sectors, and this unit is called a block.

In the case of this embodiment, as shown in FIG. 9, the majority of tracks M + 1 to N are allocated to the user block area 52 in which normal data is recorded, and the remaining tracks 0 to M is assigned to a replacement block area 51 to which a replacement block for repairing a defective block generated in a user block belonging to the user block area 52 belongs.

The optical disk drive 3 is connected to a higher-level processor 1 and a higher-level processor 1a such as a central processing unit and a channel of an electronic computer system via a plurality of optical disk controllers 2 and an optical disk controller 2a.
The optical disk drive 3 is shared by the host processors 1 and 1a.

The optical disk control devices 2 and 2a receive input / output commands issued individually from the host processing devices 1 and 1a, and control the operation of the optical disk drive device 3 so that the optical disk drive device 3 and a plurality of host processes Apparatus 1
Data is exchanged with and 1a.

Each of the optical disk control devices 2 and 2a is provided with, for example, a spare area management table 6 and a spare area management table 6a composed of a high-speed semiconductor memory or the like. For example, as shown in FIG. A bad block generated in the user block area 52 of the optical disk 5 mounted on the optical disk drive 3;
Information indicating a correspondence relationship with a replacement block in which data to be recorded in the defective block is written is held.

When a defective block is detected at the time of reading in the user block area 52, the replacement block management table 6, 6a is searched to find a replacement block corresponding to the defective block. Avoids a significant reduction in access speed.

In this case, a part of the optical disk drive 3 is provided with a memory 4 (storage means) composed of, for example, a semiconductor memory or the like which operates at high speed. For example, as shown in FIG. (First information) and a replacement area management table valid flag 41 (second information) indicating whether the information recorded in the replacement area management table 42 is valid / invalid.
) Is stored. The replacement area management table valid flag 41 indicates valid when the flag = 1, and invalid when the flag = 0.

Hereinafter, the operation of the control method of the optical disk subsystem in the present embodiment will be described with reference to the flowcharts shown in FIGS. 4 and 5.

First, a process of creating a spare area management table immediately after the optical disk 5 is loaded into the optical disk drive 3 will be described with reference to the flowchart of FIG.

When the optical disk 5 is loaded into the optical disk drive 3, the optical disk drive 3 invalidates the replacement area management table valid flag 41 of the memory 4 and sends a signal to the plurality of connected optical disk controllers 2 and 2a. It reports that the optical disk 5 has been loaded.

Next, it is assumed that the optical disk control device 2 first recognizes that the optical disk 5 has been loaded.

The optical disc control device 2 refers to the replacement area management table valid flag 41 of the memory 4 provided in the optical disc drive device 3 (step 111), checks validity / invalidity (step 112), and recognizes that the optical disk is invalid. After that, direct access to the replacement block area 51 is performed (step
113), the user block area 52 as shown in FIG.
In the optical disc control device 2, a spare area management table 6 in which address information for associating a defective block with a spare block in the above is recorded (step 11).
Four).

Thereafter, the same information as the spare area management table 6 is written in the spare area management table 42 of the memory 4 provided in the optical disk drive 3 (step 115), and the spare area management table valid flag 41 is made valid (step 11).
6).

On the other hand, another optical disk control device 2a that accesses the optical disk drive device 3 later than the optical disk control device 2
First, the spare area management table valid flag 41 is accessed in the memory 4 of the optical disc drive 3 (step
111), it is checked whether it is valid or invalid (step 112).

At this time, since the replacement area management table valid flag 41 has already been validated by the above-described processing by the other optical disc control device 2, the optical disc control device 2a
Reads the contents of the spare area management table 42 of the memory 4 of the optical disk drive 3 into its own spare area management table 6a (step 117).

Thereby, the optical disk control device 2a uses the optical disk 5
The spare area management table 6a can be created at a high speed without performing the direct access to the spare block area in duplicate.

Next, an example of processing when the replacement area management table 42 of the memory 4 of the optical disk drive 3 and the replacement area management tables 6 and 6a of the optical disk control apparatuses 2 and 2a are updated by writing data to the user block area Will be described with reference to the flowchart shown in FIG.

For example, consider a case where the host processor 1 instructs the optical disk control device 2 to write data in the user block area of the optical disk 5 of the optical disk drive 3.

First, the optical disk control device 2 that has received the data write command attempts to write to the specified user block (step 120). At this time, it is checked whether or not data writing has been successful by a read-after-write operation or the like (step 121), and if the writing has been successful, the writing operation ends.

On the other hand, if a defective block occurs during data writing, a new replacement block is assigned to the defective block, and data to be written to the defective block is written to the replacement block (step 122).

Next, the correspondence information between the newly generated defective block and the replacement block is added to the replacement area management table 6 of the optical disk control device 2 (step 123).

At this time, the correspondence information between the defective block and the replacement block is also written to the replacement area management table 42 in the memory 4 of the optical disk drive 3 (step 124), and the replacement area management of the memory 4 is performed for the other optical disk control devices 2a. It is instructed to notify that the table 42 has been updated by, for example, interrupt processing (step 125).

On the other hand, the other optical disk control device 2a notified of the update of the spare area management table 42 of the memory 4 by the interrupt processing from the optical disk drive 3 accesses the memory 4 of the optical disk drive 3, and And updates the contents of its own replacement area management table 6a.

As described above, according to the control method of the optical disk subsystem of the present embodiment, the optical disk drive 3 of the optical disk 5
At the time of loading, the spare area management table 42 and the spare area management table 6 (6a) can be created by one access to the spare block area 51 in any one optical disc control device 2 (2a). Therefore, there is no need to perform redundant access to the replacement block area 51 by the plurality of optical disk control devices 2 and 2a.

Also, even if the state of the correspondence between the defective block in the user block area 52 and the replacement block in the replacement block area 51 on the optical disk 5 changes every moment due to a write operation or the like by the arbitrary optical disk control device 2 (2a), The other optical disk control device 2a (2)
The information indicating the correspondence between the latest updated bad block and the replacement block is grasped by referring to the replacement area management table 42 in the memory 4 without performing the direct access to the replacement block area 51 of the memory 4 repeatedly. can do.

As a result, when a bad block is encountered at the position of a target track by the rotation speed of the optical disk 5 or the movement of an optical head (not shown) in the radial direction, that is, the optical disk drive 3 whose seek operation is relatively slow. The repair processing by the replacement block can be performed accurately and efficiently.

[Embodiment 2] FIG. 6 is a flowchart showing an example of a control method of an optical disk subsystem according to another embodiment of the present invention. FIG. 7 shows the contents of a memory 4 provided in the optical disk drive 3. It is explanatory drawing which shows an example of.

In the case of the first embodiment, the notification of the update of the spare area management table 42 of the memory 4 by the writing operation of the arbitrary optical disk control device 2 (2a) is interrupted from the optical disk drive device 3 to the optical disk control device 2a (2). Although the processing is performed by the processing, the second embodiment is different from the second embodiment in that the notification is made via an update flag 43 provided for each of the optical disk control devices 2 and 2a.

That is, when a defective block occurs in the data write processing by an arbitrary optical disk control device 2 (2a), the data write processing is performed by appropriately assigning the item blocks in the replacement block area, and the newly generated defective The information indicating the correspondence between the blocks and the replacement blocks is added to the replacement area management table 42 of the memory 4 of the optical disk drive 3, and the own replacement area management table 6
Update the content of (6a). At this time, in the case of the present embodiment, the bit corresponding to itself of the update flag 43 is turned off, and the other optical disc control device 2a
Turn on the bit corresponding to.

In this way, when another optical disk control device 2a accesses the optical disk drive device 3, first, as shown in FIG. 6, the update flag 43 in the memory 4 of the optical disk drive device 3 corresponds to itself. Referring to the bit to be turned on, it is checked whether it is on or off (step 130).

When it is determined that the switch is on, it is determined that the contents of the replacement area management table 6a held by itself do not match the current situation on the optical disk 5, and the replacement of the memory 4 of the optical disk drive 3 is performed. Area management table 42
And updates its own replacement area management table 6a with the latest information (step 131), and then turns off the bit corresponding to itself in the update flag 43 (step 132).

Thereafter, when the access is a read process, although not particularly shown, every time a bad block is encountered, a corresponding replacement block is found by referring to the contents of the replacement area management table 6a updated to the latest state. While performing the processing accurately.

On the other hand, if the access is a data write process, a user block write process is performed (step 13).
3) It is checked whether or not a bad block has occurred in the writing (step 134).

If a defective block has occurred, a vacant replacement block is allocated and data of the defective block is written to the replacement block (step
135), and updates the contents of its own replacement area management table 6a (step 136).

At the same time, the content of the spare area management table 42 in the memory 4 of the optical disc drive 3 is updated (step 137), and the other optical disc control device 2 which is accessed later after the content of the spare area management table 42 is updated.
To turn on the bit of the update flag 43 corresponding to the optical disc control device 2 (step 13).
8).

As described above, in the case of the second embodiment, by referring to the update flag 43 provided in the memory 4 of the optical disk drive 3, the replacement block area 51 of the optical disk 5 is controlled by the plurality of optical disk controllers 2 and 2 a. Each of the optical disk control devices 2 and 2a can recognize the information indicating the correspondence between the latest defective block and the replacement block without performing the redundant access, and write and read data using the replacement block as appropriate. Processing can be performed quickly and accurately.

Although the invention made by the inventor has been specifically described based on the embodiment, the present invention is not limited to the embodiment, and it is needless to say that various modifications can be made without departing from the gist of the invention. Absent.

For example, in each of the above-described embodiments, the spare area management table is provided in each of the optical disc control device and the optical disc drive. However, the present invention is not limited thereto, and the spare area management table may be provided only in the optical disc drive. Good.

Also, only the update information may be held inside the optical disk drive, not the replacement area management table itself.

〔The invention's effect〕

The effects obtained by typical aspects of the invention disclosed in the present application will be briefly described as follows.

That is, according to the control method of the optical disk subsystem according to the present invention, a plurality of blocks having a unique address are selectively used as a normal user block and a replacement block for relieving a writing failure in the user block. An optical disk subsystem including an optical disk, an optical disk drive for recording, reproducing, and erasing data on the optical disk, and a plurality of optical disk controllers for controlling the optical disk drive in a shared manner. A storage unit for storing first information indicating a correspondence between the defective user block and the replacement block and second information indicating whether or not the first information has been updated is provided in a part thereof. The optical disc control device determines whether the first information is valid or invalid based on the second information. This prevents duplicate access to the replacement block group by the plurality of optical disk control devices for updating the first information, so that, for example, an optical disk drive by an arbitrary optical disk control device When the first information is determined to be invalid by referring to the second information when accessing the replacement block, the direct access to the replacement block area is performed to indicate the correspondence between the defective block and the replacement block. By writing the first information into the storage means and resetting the second information so as to indicate that the first information is valid, the other optical disk control device can use the second information to execute the first information. Is effective, and there is no need to perform redundant access to the replacement block area for the purpose of newly creating the first information. That.

When the first information is changed by execution of the write process by an arbitrary optical disk control device, after completion of the write process, the first optical information is transmitted to another optical disk control device by means such as an interrupt process or a flag. By notifying that the information has changed, all the optical disk control devices can always access the optical disk of the optical disk drive using the correct first information.

Based on this result, it is possible to accurately and quickly perform data writing and reading processing including rescue processing by replacement blocks of defective blocks.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of the configuration of the optical disk subsystem of the present embodiment, FIG. 2 is an explanatory view showing an example of the main part, and FIG. FIG. 4, FIG. 4 is a flowchart showing an example of the control operation, FIG. 5 is a flowchart showing an example of the control operation, and FIG. 6 is a control of an optical disk subsystem according to another embodiment of the present invention. FIG. 7 is a flowchart showing an example of the system, FIG. 7 is an explanatory diagram showing an example of the contents of the storage means provided in the optical disk drive of the second embodiment, and FIG. FIG. 9 is an explanatory diagram showing an example of a format in the optical disc of the present embodiment. 1, 1a: Host processor, 2, 2a: Optical disk controller,
3 optical disk drive device 4 memory (storage means) 41 replacement area management table valid flag (second information) 42 replacement area management table (first information)
43 ... update flag, 5 ... optical disk, 6, 6a ... replacement area management table, 51 ... replacement block area, 52 ... user block area, 111-117 ... replacement area management table immediately after loading optical disk Steps indicating an example of a creation process, steps 120 to 125... Steps indicating an example of a user block write process, steps 130 to 138... Steps indicating an example of a user block write or read process.

Claims (1)

(57) [Claims] An optical disk in which a plurality of blocks each having a unique address are selectively used as a normal user block and a replacement block for relieving a writing defect in the user block, and recording / reproducing of data on / from the optical disk. An optical disk subsystem including an optical disk drive for erasing and a plurality of optical disk controllers for sharing and controlling the optical disk drive, wherein a part of the optical disk drive includes a defective user block and the user block. First information indicating the correspondence with the replacement block and second information indicating whether or not the first information has been updated
Storage means for storing the first information and the second information are determined by the validity / invalidity of the first information based on the second information. A plurality of the optical disk control devices to avoid redundant access to the replacement block group.