JPH06139718A - Synchronization error discrimination system for optical disk device - Google Patents

Abstract

PURPOSE:To prevent the generation of an error at the time of reading by discriminating the generation of a synchronous error in a corresponding sector at the time of reading by a synchronous error routine based on the value of the number of stored errors. CONSTITUTION:At the optical disk device provided with a CPU 21, a memory 25 for storing data error number and a synchronous error discrimination reference value memory 26, an unrecoverble error is generated when the specific sector of a recording medium is read, the number of data errors is counted each time a first reading and a retrial reading operation following this are carried out when the retrial reading operation is executed within a number of times set beforehand and it is stored in the data error number storing memory 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronization error determination system in an optical disk device for determining a synchronization error during data read and retry processing.

[0002]

2. Description of the Related Art An optical information recording / reproducing apparatus disclosed in Japanese Patent Laid-Open No. 63-298876 can be given as a synchronization error determining method in an optical disk apparatus of this type. In this "optical information recording / reproducing apparatus", the replacement process is performed when the number of error corrections of the data read from the disc exceeds a specific reference value.

In an optical disk device, when writing data into a specific sector of a recording medium at the time of a write operation, if the synchronization byte is not surely written, if the sector is read, the detection of the synchronization byte becomes unstable. . As a result, there are cases where normal reading can be performed even if the same sector is read, and cases where an error, that is, a synchronization byte cannot be accurately detected. If this cannot be detected, the data portion following the byte for synchronization cannot be read normally. In this case, data errors occur frequently, unrecovered errors that exceed the error correction allowable range occur, and the data in the sector cannot be read normally.

[0004]

As described above, in the above conventional example, when the synchronization byte is not surely written, the detection of the synchronization byte becomes unstable when the sector is read, and an error occurs. May occur and the sector data cannot be read normally.

The present invention solves the problems in the prior art as described above. As a first object of the present invention, whether or not a sector is apt to cause a synchronization error at the time of read based on the stored error number value. Therefore, it is possible to determine whether or not the error occurs at the time of reading, and to provide a synchronization error determination method in an optical disc device.

A second object of the present invention is to provide a synchronization error determination method in an optical disk device, which makes it possible to replace the determined sector as a defect so that replacement processing can be performed when necessary, and as a result, an error occurrence at the time of reading can be eliminated.

A third object of the present invention is to provide a synchronization error determination method in an optical disk device which can change the determination standard of the synchronization error for each recording medium, and consequently can eliminate the error occurrence at the time of reading.

[0008]

In order to achieve the above-mentioned object, the invention of claim 1 corresponding to the first object has at least a central processing unit, a data error number storage memory, and a synchronization error determination reference value memory. If there is an unrecoverable error when reading a specific sector of the recording medium in the synchronization error judgment method in the optical disc device during data read and retry processing in the provided optical disc device, within the preset number of times. In the retry read operation, the number of data errors in each of the first read and the retry read operation following this read is counted and stored in the data error number storage memory.

According to a second object of the present invention, which corresponds to the second object, the first read and the retry read operation following this read in the synchronous error judging method in the optical disk device at the time of judging the defective sector in the read and retry processing of the first invention. The number of data errors when an unrecovered error occurs is compared with the number of data errors when the data is normally read by the retry read operation after this data error occurs, and the difference is the preset value. When it exceeds the limit, the sector is regarded as a defective sector and the replacement process is automatically performed.

According to a third aspect of the present invention, which corresponds to the third object, the number of data errors when an error occurs and the data is normally read in the synchronous error determination method in the optical disk device at the time of determining the defective sector in the second aspect. A value that serves as a reference when the number of data errors at that time is compared is registered in the recording medium management table.

[0011]

According to the first aspect of the present invention having such a configuration, the number of data errors per read routine for a predetermined sector can be counted and stored when reading and writing data. It becomes possible to judge whether or not the sector is apt to cause a synchronization error at the time of reading based on the value of, and as a result, the error occurrence at the time of reading can be eliminated.

According to a second aspect of the present invention, at the time of sector determination, the values of the number of data errors per read routine according to the first aspect are compared to determine whether or not a synchronization error is likely to occur in the determined sector. As a result, it is possible to replace the judged sector as a defect when necessary, and as a result, it is possible to eliminate the error occurrence at the time of reading.

According to a third aspect of the present invention, the reference value for determining whether or not the sector in the second aspect is likely to cause a synchronization error is registered in the recording medium management table. Therefore, the synchronization error determination criterion for each recording medium is registered. You can change
As a result, it is possible to eliminate the error occurrence at the time of reading.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a synchronization error determination method in an optical disk device of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of a synchronization error determination system in an optical disk device of the present invention. In FIG. 1, a host device 10 and this host device 1
An optical disk device 12 that performs data processing with 0 and a disk device 14 that stores data processed by the optical disk device 12 are roughly configured.

The optical disk device 12 has a conventional CPU 2
1, ROM 22, RAM 23, data buffer 2
4 and. The optical disk device 12 further includes a data error number storage memory 25 for storing a data error number value, a sync error determination reference value memory 26 for storing a reference value at the time of determining a synchronization error, and a SCSI controller. 27, a disk control unit 28, and a bus line 29 connecting them.

Next, the operation of the configuration of this embodiment will be described. FIG. 2 is a flowchart showing a processing procedure in this operation. In FIG. 1 and FIG. 2, a storage medium (not shown) is attached to the disk device 14.

The CPU 21 of the optical disk device 12 reads the synchronization error determination reference value registered in advance in the management table of the storage medium. The read synchronization error determination reference value is temporarily stored in the synchronization error determination reference value memory 26 in the optical disk device 12 until the processing is completed.

When an unrecovered error occurs inside the optical disk device 12 during a read operation, the value of the number of data errors at that time is stored in the data error number storage memory 25 in the optical disk device 12 (step (S in the figure). 10)).

After that, a retry read operation is repeated until the data can be read normally. Alternatively, it is repeated until the preset number of retries reaches the maximum value "X" (steps 11 and 12). In this process, the value of the number of data errors for each time is stored in the data error number storage memory 25 in the optical disk device 12.

If the data is normally read during the retry read operation, the result of step 13 is Yes, the value of the data error number at that time and the maximum value "X" of the data error number storage memory 25 in the optical disk device 12 are set. When the difference is larger than the value in the synchronization error judgment reference value memory 26, this sector is regarded as a sector in which a synchronization error is likely to occur (steps 14 and 15). After this, a replacement process is automatically performed (step 16).

The reason why the sector is considered to be prone to a synchronization error is as follows. The synchronization error is an error in which the number of data errors becomes extremely larger than the error-correctable allowable range because the synchronization byte cannot be reliably read during the read operation of a specific sector. Therefore, the optical disk device 12 is internally processed as an unrecovered read error. The sector in which the synchronization error is likely to occur is a sector in which the synchronization byte is difficult to read at the time of reading.

In some cases, the value of the number of data errors is determined depending on whether the synchronization byte is read out normally in the sector or if the synchronization error causes an unrecovered error and the synchronization byte cannot be read out normally. Are extremely different. Therefore, there is an extreme difference between the value of the number of data errors when an unrecovered error occurs when retrieving a specific sector and the value of the number of data errors when the data is normally read (the synchronization error determination criterion in step 10). If there is a value, it can be determined that a synchronization error is likely to occur in this sector.

Therefore, if an unrecoverable error continues to occur even after retrying the maximum number of retries set in advance after step 16, the result is reported to the host (step 17).

The synchronization error determination reference value may be changed by the user by issuing a command from the host device. In this case, it becomes possible to effectively determine a synchronization error on a disc that is used frequently.

[0026]

As is apparent from the above description, according to the first aspect, the number of data errors per read routine for a predetermined sector can be counted and stored when reading and writing data. Therefore, it is possible to judge whether or not the sector is likely to cause a synchronization error at the time of reading based on the stored value of the number of errors, and as a result, it is possible to eliminate the error occurrence at the time of reading. According to a second aspect of the present invention, at the time of sector determination, the values of the number of data errors for each read routine of the first aspect are compared,
Since it is possible to determine whether or not a synchronization error is likely to occur in the determined sector, it is possible to replace the determined sector as a defect and perform replacement processing when necessary, and as a result, it is possible to eliminate the error occurrence during read. . Claim 3
Then, since the reference value for judging whether or not the sector in which the synchronization error is likely to occur is registered in the recording medium management table, the judgment standard for the synchronization error can be changed for each recording medium. As a result, there is an effect that an error occurrence at the time of reading can be eliminated.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration in an embodiment of a synchronization error determination method in an optical disc device of the present invention.

FIG. 2 is a flowchart showing a processing procedure in the operation of the embodiment.

[Explanation of symbols]

 10 host device 12 optical disk device 14 disk device 21 CPU 22 ROM 23 RAM 24 data buffer 25 data error number storage memory 26 synchronization error determination reference value memory 27 SCSI controller 28 bus line

Claims (3)

[Claims] 1. A synchronization error judgment method in an optical disk device at the time of data read and retry processing in an optical disk device including at least a central processing unit, a data error number storage memory, and a synchronization error judgment reference value memory, wherein a recording medium is provided. If an unrecovered error occurs during the reading of a specific sector, the number of data errors in the first read and the retry read operation following this read is counted during the retry read operation within the preset number of times. A method for determining a synchronization error in an optical disk device, wherein the data is stored in the memory for storing the number of data errors. 2. A synchronization error determination method in an optical disk device for determining a defective sector in the read and retry processing according to claim 1, wherein an unrecovered error occurs in a first read and a retry read operation following this read. The number of data errors is compared with the number of data errors when the data is read normally in the retry read operation after this data error occurs, and if the difference exceeds the preset value, the sector is defective. A synchronization error determination method in an optical disk device, which is characterized by automatically performing replacement processing by treating it as a sector. 3. The method of synchronizing error judgment in an optical disk device at the time of judging a defective sector according to claim 2, wherein the number of data errors when an error occurs and the number of data errors when reading data normally are compared. A synchronization error determination method in an optical disk device, characterized in that a reference value is registered in a recording medium management table.