JP3032321B2 - Access control method for optical disk device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an access control system for an optical disk device which can be connected to and controlled by an optical disk device without changing the access control function of a magnetic tape device of a host device. An optical disk device is receiving attention as a large-capacity partial storage device. On the other hand, as a large-capacity external storage device currently used, there is a magnetic tape storage device.

Therefore, if an optical disk device can be connected to a computer system having a control function of a magnetic tape storage device without changing the control function, the active use of the optical disk device will be promoted.

[0003]

2. Description of the Related Art In recent optical disk technology, there is a tendency to use an optical disk device as a large-capacity external storage device like a magnetic tape storage device. This is a method in which an optical disk device is apparently used as a magnetic tape storage device without changing upper-layer (CPU) software.

Although the optical disk device has been remarkably developed recently, it can be said that it is not yet versatile in comparison with a magnetic tape storage device because of its software compatibility. Therefore, if an optical disk device can be made compatible with a magnetic tape storage device having high versatility, the optical disk device will be a new type of optical disk device in the future because it is more compact and has a larger capacity than a magnetic tape device. it is conceivable that.

[0005]

However, in order to use an optical disk device as a magnetic tape storage device, data transfer at the time of writing or reading must be performed by variable length transfer like a magnetic tape storage device. In other words, the magnetic tape storage device has a transfer buffer but does not have a buffer for storing all data when transferring data sent from the host device to the drive via the controller. This is because the magnetic tape storage handles variable length data and the magnetic tape is not formatted.

On the other hand, an optical disk device handles fixed-length data, and an optical disk can be written only in formatted sectors. Therefore, in order to provide compatibility, it is necessary to convert variable-length data transferred from a higher-level device into fixed-length data that can be written to an optical disk. There is a problem that it is necessary to return to data and transfer it to the host device.

Further, in order to use an optical disk device as a magnetic tape storage device, a "readback word (READBACKWORD) command" which is a read command unique to a magnetic tape is used.
Must be executable. The read backward command is a command for reading the data by running the magnetic tape in the reverse direction with respect to the head, and transferring the data to the host device in the reverse order of writing.

However, since the optical disk drives the optical disk in a fixed direction and does not have a function of reading from the reverse direction, the controller must be provided with a data transfer function that is compatible with the read backward.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is intended to appropriately convert between variable-length data and fixed-length data for realizing compatibility with a magnetic tape device. It is another object of the present invention to provide an access control method for an optical disk device. Another object of the invention is to provide
It is an object of the present invention to provide an access control method of an optical disk device in which management information for each block is provided in a medium itself to easily perform block positioning at the time of reading.

Another object of the present invention is to provide an access control method for an optical disk apparatus which enables execution of a read backward command for reading and transferring medium data in a reverse direction.

[0011]

FIG. 1 is a diagram illustrating the principle of the present invention. First, the present invention is directed to an access control method of an optical disk device that performs data writing or reading in response to access control of a magnetic tape device by a host device 1.
In other words, the present invention is directed to an access control method of an optical disk device that can be used by connecting an optical disk device to a host device 1 having an access control function of a magnetic tape storage device without changing software.

According to the present invention, such an access control method for an optical disk device is, as shown in FIGS. 1A and 1B, at the time of writing, the data transferred from the host device 1 to the data transfer buffer 2. Management information creating means 3 for creating management information for one block including the number of sectors used on the disk medium and the number of padding data for filling the vacant portion of the last used sector based on the write data for the block is provided. The block management information, write data, and padding data are written in the medium sector constituting the designated block in the order of the data.

At the time of reading, the padding data is removed from the read data on the basis of the number of padding data in the management information of the block read from the head position of the sector group constituting the designated block by the reading means 5 and the host device 1
Transfer to

As described above, since the management information is written in each of the write sector groups corresponding to the data of one block, the reading means 5 can normally read the block management information of the first sector constituting the designated block. If the data cannot be read, the read data is transferred to the higher-level device using the sector management information of each succeeding sector so that destruction of the block management information on the disk medium can be dealt with. Further, in the present invention, as shown in FIG. 1C, the management information creating means 3 sends the data transfer buffer 2 from the host device 1 at the time of writing.
The block management information for each block including at least the block address, the number of data, and the number of sectors used is created based on the write data transferred to the storage unit. After collectively writing the block management information, the write data is written to the sector configuring the designated block.

[0015] Therefore reading means 5, when the lead, intends head sector with reference to a block address of the block management information read from the read knowing the number of used data and the number of sectors rows of the medium.

[0016]

According to the access control method of the optical disk device of the present invention having the above-described structure, the following effects can be obtained.
First, for the transfer of one block of write data from the host device 1, all data is transferred to the data transfer buffer 2.
In order to determine the variable-length data amount.

When the amount of variable-length data is known, the number of bytes per sector is determined based on the disk format. Therefore, the number of sectors necessary for writing all data including the number of bytes of management information is calculated. In this case, when all data is divided by the number of bytes for one sector, usually a remainder is generated, and therefore, an empty portion is generated in the last used sector. Therefore, the number of data filling the empty portion of the last used sector is calculated as the number of padding data, and the management data, write data, and padding data are written so as to fit exactly into the calculated sector.

On the other hand, at the time of reading, the number of padding data is known from the management information at the head position of the sector group of the read block, and the number of padding data is removed from the read data and transferred to the data transfer buffer 2. Transfer as long data. As a result, the host device 1 can appropriately access the optical disk device as a magnetic tape storage device, and compatibility with the magnetic tape storage device is established.

Further, by recording the sector-specific management information for each sector when recording on the disk medium, even if the management information relating to the entire first block is destroyed, a read access can be made based on the subsequent sector management information. Guarantee reliability. Note that a block and a sector are the same terms indicating the same one data unit, but a block is a term used in software for accessing a magnetic tape storage device.
On the other hand, a sector is a term used in hardware for accessing a disk medium.

Further, since blocks on a magnetic tape are variable-length data, when viewed from sectors of a fixed-length optical disk, one block is composed of one or more sectors. Next, random read access can be easily performed by collectively storing the block management information for each block in the first sector of the disk medium.

That is, since the block address, the number of data, and the number of sectors used for each block created at the time of writing are collectively written in the first sector of the optical disk, the data is read by referring to the block management information of the first sector. Knowing the number and the number of sectors used, the head can be easily positioned with respect to the medium. Further, when receiving a read backward command which is a unique command for the magnetic tape storage device, the read data of the designated block is stored in the buffer, and thereafter read in the reverse direction and transferred to the higher order device, whereby the higher order device is read. An optical disk device can be used as a magnetic tape storage device without changing the function.

[0022]

【Example】

[Processing of Padding Information] FIG. 2 is a block diagram showing an embodiment of the first embodiment of the present invention, which is generated in fixed-length data when converting variable-length data from a higher-level device into fixed-length data on an optical disk. It is characterized in that padding processing for filling a vacant portion is performed.

In FIG. 2, reference numeral 1 denotes a CP as a higher-level device.
U, and the CPU 1 is provided with an access control function (software) for the magnetic tape storage device. CPU1
Controller 10 and optical disk drive 20
Is connected. The transfer method between the controller 10 and the optical disk drive 20 is as follows.
In the case of the present invention, an interface capable of notifying the number of transfer blocks from the controller 10 to the optical disk drive 20 prior to data transfer is required. As such an interface, the most widely used SCSI can be used at present.

The controller 10 is provided with an MPU 11 for performing overall control of the disk. The MPU 11 receives and analyzes a command from the CPU 1 via the driver / receiver 12, and sends a control command to the lower optical disk drive 20 via the driver / receiver 13. The optical disk drive 20 controls the optical disk 2 in accordance with the control command received from the MPU 11 via the driver / receiver 21.
3, a seek operation for positioning the laser beam from the optical head 22 on the target track, a positioning operation for on-tracking the laser beam on the target track, writing or reading of data, and further erasing.

The controller 10 is provided with a data transfer buffer 2, and the buffer capacity is set to a capacity that satisfies the maximum transfer capacity of variable-length data from the CPU 1.
At present, the maximum number of data transfers to and from a magnetic tape storage device varies as 32 Kbytes or 64 Kbytes.
Prepare a buffer capacity larger than the maximum transfer number so as to satisfy the required maximum data transfer number.

The MPU 11 receives a system storage (CS) 14, an external register 15, and a counter unit 16. The counter unit 16 has a sector counter for counting the number of sectors on the optical disk 22, and data of write data for the optical disk. A data counter that counts the number of data, a padding counter that counts the number of padding data to be put in the empty area of the sector, and a block counter that counts the number of data blocks serving as recording units on the magnetic tape, that is, a block address. I have.

Further, the MPU 11 manages one block including the number of sectors used on the optical disk 23 and the number of padding data for filling the empty portion of the last used sector based on the write data transferred from the CPU 1 to the data transfer buffer 2 at the time of writing. A function as management information creating means for creating information; a function as writing means for writing data to the optical disc 23 in the order of management information, write data and padding data; and a sector group constituting a designated block at the time of reading. The function as a reading means for removing the padding data from the read data and transferring it to the CPU 1 based on the number of padding data in the management information read from the head position of the control information is realized by program control.

The write operation by the MPU 11 is performed by the CPU 1
When a write command is received, the transfer data from the CPU 1 is temporarily stored in the data transfer buffer 2, and the data length of the variable-length write data is grasped. Subsequently, the MPU 11 that has grasped the data length obtains the number of sectors used to write the variable-length write data using the number of sectors formatted on the optical disk 23.

Here, the MPU 11 provides a storage area for management information at the head of data to be written on the optical disk 23 in order to know the data length and padding information from the CPU 1. The storage area for this management information is, for example, 32 bytes. Of course, an appropriate bust number can be used as needed. Therefore, the actual data length to be written into the optical disk 23 is (management information) + (write data), and the number of sectors used and the number of padding data are obtained from this data length.

FIG. 3 shows a sector write state on the optical disk 23 when 3.5 Kbytes of write data has been transferred from the CPU 1, and a 32-byte storage area for storing head management information is secured. The number of sectors formatted on the optical disk 23 is 512 sectors and 1024 bytes per sector. Here, the management information on the 32-byte block stored in the first sector at the beginning is as follows: (1) block address (2) number of sectors used (3) number of data (4) number of padding data (5) sector of next block It consists of an address.

Here, the number of sectors used is calculated by calculating (management information + the number of data) / (the number of bytes in one sector), and if there is a remainder, it is increased by one. When the number of data is 3.5 Kbytes, the number of sectors used is 4 sectors.

Next, the number of padding data is calculated as (total number of used sectors data)-(management information + number of data). When the number of data is 3.5 Kbytes, (4 × 1024) − (32 + 3.5 × 1024) = 48
Calculated as 0 bytes.

When the management information including the calculation of the number of used sectors and the number of padding data is completed, the MPU 1
After notifying the optical disk drive 20 of the number of sectors used, 1 transfers the management information, data, and padding data (all 0s) in order, and writes the management information, data, and padding data on the optical disk 23 by the laser beam from the optical head 22. On the other hand, CPU1
When a read command is received, the MPU 11 notifies the optical disk drive 20 of the designated track, seeks to the target track, reads a group of sectors constituting a designated block determined by a block address of the designated track, and performs data transfer. To the transfer buffer 2.

Next, the number of padding data is known by referring to the leading management information in the read data of the designated block stored in the data transfer buffer 2. When transferring the read data stored in the data transfer buffer 2 to the CPU 1, only the true read data excluding the leading 32 bytes of management information and the last padding data is transferred.

FIG. 4 shows the M provided in the controller 10 of FIG.
9 is a flowchart showing a transfer operation to the optical disk drive 20 when the PU 11 writes. In FIG. 4, when write data is transmitted based on a write command from the CPU 1 and stored in the data transfer buffer 2, the MPU starts a data transfer operation to the optical disk drive 20.

In this data transfer operation, first, in step S1
Then, the number of write data, for example, 3.5 Kbytes, is confirmed from the data stored in the data transfer buffer 2. Next, in step S2, the number of sectors used 4 is calculated from the 3.5K bytes of data. In step S3, the number of padding data of 480 bytes for padding the last fourth sector with zero padding in consideration of 32 bytes of management information is calculated. Ask.

In step S4, it is determined that the sector address of the next block is the fifth sector.
The management information shown in FIG. 3 is created in step S5 based on the result of step S4. After creating the management information, the optical disk drive 20 is notified of the number of used sectors 4, and then in step S6, the transfer of the 32-byte management information and 922 bytes of data to the first sector is started, and the writing to the first sector is performed. .

Subsequently, in step S7, the second sector and the third sector
Data transfer of 1024 bytes to the sector is repeated. Next, in step S8, the transfer of the last 544 bytes of data and 480 bytes of padding data for the fourth sector is started, the fourth sector is written, and the transfer is waited for after the notification of the normal end from the optical disk drive 20. finish.

FIG. 5 shows an MPU provided in the controller of FIG.
11 is a flow chart showing a transfer operation at the time of reading by No. 11. In FIG. 5, the optical disk drive 2 receives a read command from the CPU 1 and receives an instruction from the MPU 11.
When the read data of the designated block is stored in the data transfer buffer 2 from 0, the data transfer operation to the CPU 1 is started.

First, in step S1, the designated block address of the read data stored in the data transfer buffer 2 is searched to refer to the management information at the head of the first sector. Knowing that this is the fourth sector, the number of padding data is obtained. Subsequently, in step S3, the first 3
The transfer of 3.5 Kbytes of data excluding the 2-byte management information and the 480-byte padding data of the fourth sector to the CPU 1 is started, and the transfer ends.

FIG. 6 is an explanatory diagram showing another embodiment of the data management information in FIG. 2. In this embodiment,
In addition to the management information relating to the block of the first sector, the head of each sector has management information unique to the sector, whereby it is possible to confirm what kind of information is in the sector and to perform more accurate data transfer. It is characterized by having done.

FIG. 6 exemplifies a case where the number of data is 3.5 Kbytes and 1024 bytes per sector, as in FIG. 3, and a 32-byte management information storage area is secured at the head of each sector. As the management information at the head of the first sector, in addition to the management information relating to the block in FIG. 3, (6) the number of data of this sector, and (7) the sector-specific management information that becomes the next sector address is added.

Also, the second sector and the third
For the sector, (1) a block address, (2) a sector number (the number of blocks), (3) a number of data, and (4) a sector-specific management information serving as a next sector address is stored.

Further, regarding the last fourth sector where padding is performed, (1) block address (2) sector number (number of blocks) (3) number of data (4) number of padding data (5) next block address Is stored.

When each sector has sector-specific management information as described above, accurate data transfer is enabled, and even if the management area of the block stored at the head of the first sector is destroyed, The data of the sector can be read from the management information of the management area unique to the sector that has not been destroyed. FIG. 7 is a flowchart showing the write data transfer operation using the data management information of FIG.
This is basically the same as FIG.

The difference is that the calculation of the number of padding data in step S3 is performed by adding a management area of 32 bytes for each sector. That is, assuming that the number of sectors used is four, the management area for all sectors is 4 sectors × 32 bytes = 128 bytes, and the number of padding is (4 × 1024) − (128 + 3.5 × 1024) = 3
84 bytes.

In steps S5 and S6, 992 bytes of data of each sector are obtained, and the next sector address is obtained. Further, in step S8, 32 bytes of management information and 992 bytes of data are transferred for the first to third sectors, and in the fourth sector of step S8, 32 bytes of management information, 608 bytes of data, and 384 bytes of padding data are further transferred. Will be transferred.

FIG. 8 is a flow chart showing the read data transfer operation when the management information of FIG. 6 is used, which is basically the same as that of FIG. 5, but is provided for each sector in step S3. The difference is that the management information is deleted and transferred.

[Access Control of Optical Disk Based on Block Management Information] FIG. 9 is a block diagram showing an embodiment showing a second embodiment of the present invention. In this embodiment, the first sector of the optical disk 23 is written on the optical disk. The block management information of all the blocks is collectively stored, and the head is easily positioned by referring to the block management information at the time of read access.

In FIG. 9, the controller 10 and the optical disk drive 20 are basically the same as those in the embodiment of FIG. 2, but a block management buffer 18 is provided in the controller 10. Further, the MPU 11 of the controller 10 creates management information for creating block management information of the optical disc 23 including at least a block address, the number of data, and the number of sectors used based on the write data transferred from the CPU to the data transfer buffer 2 at the time of writing. Function as a means, and an optical disk 23 having predetermined block management information.
Position, for example, a function as a writing means for writing write data to the sector of the designated block address after writing to the first sector, and further, at the time of reading, reading the block management information from the first sector of the optical disk 23 to read the block management buffer. The function as a reading means for reading by developing and referring to 18 and knowing the number of data and the number of sectors used of the block address to be read is realized by program control.

FIG. 10 shows an optical disk 2 according to the embodiment of FIG.
3 shows block management information of each block collectively stored in the first sector of No. 3. The first sector as the management area is
This is a system area that can be accessed only by the controller 10, and the user area that can be accessed by the CPU 1 from the first sector onward.

In this example, blocks 1, 2, 3,... And data are stored for each sector following the first sector as a system area. Note that, for convenience of explanation, a case where the data length of one block is 1024 bytes which matches one sector is shown, but one block is variable-length data having a maximum of 32 Kbytes or 64 Kbytes, for example. Will form a block.

The block management information of the first sector stores (1) block address, (2) number of data, and (3) number of sectors used for each block.

For this reason, the optical disk 2 is read from the block management information developed in the block management buffer 18 at the time of reading.
3, the number of data and the number of sectors in the designated block address can be recognized, the buffer 2 for data transfer can be secured, and preparation processing required for read access can be performed. Further, the number of transfer bytes is counted and read by comparing with the number of data. The controller 10 can recognize whether the data transfer has been performed normally.

FIG. 11 is a flowchart showing the transfer operation at the time of writing to the first block of the optical disk 23 by the MPU 11 of FIG. In FIG. 11, CPU 1
When the transfer of the write data to the data transfer buffer 2 is completed, the MPU 11
Starts the transfer operation for.

That is, when data transfer of the first block is started in step S1, block address data is created in step S2, the number of data is created in step S3, and the number of sectors used is obtained in step S4. In S5, the creation information of steps S2 to S3 is written as the block management information of the first block in the leading sector of the optical disc 23.

Subsequently, in step S6, the write data is written to the sector constituting the first block of the optical disk 23.
FIG. 12 is a flowchart showing a write operation for the second block. In FIG. 12, first, in step S1, the block management information of the first sector of the optical disk 23 is read and the block management buffer 18 in the controller 10 is read.
Expand to

Subsequently, the data transfer of the second block is started in step S2, block address data is created in step S3, and the number of data is created in step S4.
Further, in step S5, the number of sectors used is obtained, and in step S6
Then, the block management information of the second block obtained in steps S3 to S5 is added to the block management buffer 18.

Subsequently, in step S7, the block management information of the second block obtained in steps S3 to S5 is added to the block management information of the first sector of the optical disk 23. Addition of the block management information of the second block described above,
That is, when the update is completed, the data is written to the sector constituting the second block of the optical disc 23 in step S8. still,
The third and subsequent blocks are the same as those in FIG.

FIG. 13 is a flowchart showing the read operation of the embodiment of FIG. 13, first, in step S1, block management information is read from the head sector of the optical disk 23 and is expanded in the block management buffer 18 of the controller 10. Next, in step S2, it is confirmed which block is the data transfer by the read access, and the block address, the number of data, and the number of sectors used are recognized by referring to the designated block in the block management information.

Subsequently, in step S4, a control command is emitted to the optical disk drive 20 to seek the head, and the data of the designated block is read and transferred. FIGS. 14 and 15 are flowcharts showing a processing operation when the block management information is expanded from the optical disk 23 to the controller 10 when the optical disk 23 is loaded, and the storage (update) from the controller 10 to the optical disk 23 is performed when the optical disk 23 is unloaded. It is.

That is, in the read operation of FIG. 13, every time a block is read, the block management information is read from the first sector of the optical disk 23 and is developed in the block management buffer 18. However, in FIG. When the loading operation for inserting the optical disk 23 into the optical disk drive 20 is performed in step S2, the head sector is read out in step S2 and expanded in the block management buffer 18 of the controller 10,
In step S3, the process returns to the idle routine waiting for access.

In the write operation shown in FIGS. 11 and 12, update processing for adding newly created block management information to the block management buffer 18 and the first sector of the optical disk 23 is performed for each write operation. At the time of the write operation, only the update to the block management buffer 18 is performed. For the update to the optical disk 23, as shown in FIG. 15, if the instruction to send the optical disk is issued in step S1, that is, if the unload operation is instructed, the block management is performed in step S2. The block management information of the buffer 18 is transferred to the optical disk 2
After writing and updating the first sector of No. 3, an unload operation for sending the optical disk 23 to the outside is performed in step S 3, and an update process for returning to the idle routine is performed in step S 4.

By such processing, write access can be made more efficient by the amount that the block management information for the optical disk 23 need not be updated at the time of writing.

[Read Backward Processing] FIG. 16 is a block diagram showing an embodiment of the third embodiment of the present invention. This embodiment is adapted to cope with a read backward instruction which is an instruction unique to a magnetic tape storage device. It is characterized by the following.
That is, when a read back instruction is issued from the CPU 1 to the magnetic tape storage device, a block one block backward from the designated block is positioned relative to the head by tape running, and then the tape is moved in the reverse direction (tape start position). B
The data is read while traveling in the direction of OT) and transferred to the host CPU.

At this time, the data is transferred from the reverse direction without rearranging, and is rearranged in the forward direction by the I / O device portion of the CPU 1. However, the optical disc device is
The optical disk rotates in a certain direction, and cannot be read in the opposite direction like a magnetic tape. FIG.
In the embodiment of the present invention, when receiving a readback command by block designation from the CPU 1, the controller 10 reads the designated block as usual,
0, the designated block is read from the optical disk 23 and transferred to the data transfer buffer 18, and the data is read and transferred in reverse when transferred from the data transfer buffer 18 to the CPU 1. Enable to transfer the same data as read in the direction.

In FIG. 16, the controller 10 and the magnetic disk drive 20 are basically the same as those in the embodiment of FIG. 2, except that the counter 16 stores a block counter and A sector counter is provided, and a transfer counter 19 is provided with a transfer counter, a reverse transfer counter, and a byte counter in order to manage a read transfer from the data transfer buffer 2 to the CPU 1 in the reverse direction.

Further, in addition to the normal access control function, the MPU 11 receives read-back instructions from the CPU 1 for reading data from the optical disk 23 in the reverse direction and transferring the data from the optical disk 23, and transfers the read data of the designated block to the optical disk 23. From the data transfer buffer 2 and then read in the reverse direction and transfer it to the host device.

Next, referring to the flowchart of FIG.
A read operation in a state where the optical head 23 is positioned on a track of a block for performing readback will be described. First, the optical head 23 of the optical disc drive 20
Is on-track to an arbitrary track specified by the controller 10, and it is assumed that a read backward instruction has been issued to a block belonging to this track.

First, in step S1, it is confirmed that the track where the head is currently located is the same track as the track to be read. Subsequently, the process proceeds to step S2, where the designated block in the track where the head is currently positioned is read, and in step S3, the data is transferred to the data transfer buffer 2 of the controller 10 and stored in the read order.

In the transfer of read data from the optical disk drive 20 to the data transfer buffer 2, the counter is incremented by one in the reverse transfer counter and the byte counter every time one byte of data is transferred. When the data transfer to the data transfer buffer 2 is completed, the data is read from the reverse direction using the reverse transfer counter and the byte counter and transferred to the CPU 1 in step S4.

That is, data is transferred one byte at a time from the last address of the read data stored in the data transfer buffer 2 in the reverse direction, and the reverse transfer counter is decremented by -1 each time this one byte of data is transferred. . On the other hand, the transfer counter is incremented by +1 every time 1-byte data is transferred. After the transfer of all data is completed, the transfer counter and the byte counter counted up in step S3 are compared, and if they match, the number of transferred bytes is confirmed.

Therefore, the first data transferred from the optical disk drive 20 to the controller 10 is transferred to the CPU 1 so as to be the last data to be transferred. FIG.
Reference numeral 8 denotes a read operation in a state where the head is positioned on a different track from the block on which the readback is performed. First, in step S1, when it is confirmed that the track where the head is currently located is different from the track of the designated block, the process proceeds to step S2, where the track counter is changed to the value of the track to which the designated block belongs, and the head is sought.

For example, as shown in FIG.
Assuming that a read backward instruction designating the tenth block of the outer track is issued in a state where the eighth to thirty-fourth blocks are positioned on the inner track where they are stored,
The track counter is decremented by 1 to seek the head to the outer track. The transfer operation of the read data in steps S3 to S5 is the same as in FIG.

When the data transfer to the CPU 1 is completed, the track address is updated by -1 in step S6, and the block address is decremented by 1 in step S7 to prepare for the next read. Although FIG. 19 shows concentric tracks, the same applies to spiral tracks.

[0076]

As described above, according to the present invention, conversion of variable-length data into fixed-length data, transfer of read data corresponding to a read-backward instruction, and block management information enabling random access are performed. The access control based on the above makes it possible to use the optical disk device instead of the magnetic tape storage device without changing the software of the host device, and to achieve compatibility with a highly versatile magnetic tape storage device.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a configuration diagram of a first embodiment of the present invention.

FIG. 3 is an explanatory diagram of management information and padding data when one block of data is written on an optical disk according to the embodiment of FIG. 2;

FIG. 4 is a flowchart showing a write operation of FIG. 2;

FIG. 5 is a flowchart showing a read operation of FIG. 2;

FIG. 6 is an explanatory diagram of management information and padding data on an optical disc when management information is added for each sector in the embodiment of FIG. 2;

FIG. 7 is a flowchart showing a write operation involving creation of management information in FIG. 6;

FIG. 8 is a flowchart showing a read operation using the management information of FIG. 6;

FIG. 9 is a configuration diagram of an embodiment showing a second embodiment of the present invention.

FIG. 10 is an explanatory diagram of management information of the entire block written in the first sector of the optical disc in the embodiment of FIG. 9;

FIG. 11 is a flowchart showing a write operation of a first block in FIG. 9;

FIG. 12 is a flowchart showing a write operation of a second block in FIG. 9;

FIG. 13 is a flowchart showing the read operation of FIG. 9;

14 is a flowchart showing processing for expanding block management information in a memory in a controller when loading an optical disc in the embodiment of FIG. 9;

FIG. 15 is a flowchart showing processing for updating block management information when the optical disc is unloaded in the embodiment of FIG. 9;

FIG. 16 is a configuration diagram of an embodiment showing a third embodiment of the present invention.

FIG. 17 is a flowchart showing readback processing when the optical head is positioned on a track of a designated block in the embodiment of FIG. 16;

FIG. 18 is a flowchart showing readback processing when the optical head is located on a different track from the designated block in the embodiment of FIG. 16;

FIG. 19 is an explanatory diagram schematically showing a track state of an optical disc in the process of FIG. 18;

[Explanation of symbols]

 1: Upper device (CPU) 2: Buffer for data transfer 3: Management information creating means 4: Writing means 5: Reading means 10: Controller 11: MPU 12, 13, 21: Driver / receiver (DV / RV) 14: System storage (CS) 15: External register 16: Counter unit 18: Block management buffer 19: Transfer counter unit 20: Optical disk driver 22: Optical head 23: Optical disk

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G06F 3/06 301 G06F 3/06 303 G06F 3/08 G11B 7/00 G11B 20/12

Claims (2)

(57) [Claims] In an access control method for an optical disk device which performs data writing or reading in response to access control of a magnetic tape device by an upper device (1), a data transfer buffer (1) is written from the upper device (1) at the time of writing. A management information creating means (3) for creating management information of the block including the number of sectors used in the medium and the number of padding data to fill a vacant portion of the last used sector based on the write data of one block transferred in 2); Writing means (4) for writing data to the designated sector in the order of the management information, write data and padding data; and at the time of reading, based on the number of padding data in the management information read from the sector head position of the designated block. Reading means (5) for removing padding data from read data and transferring it to a higher-level device. Access control method for optical disk devices. 2. An access control method for an optical disk device which performs data writing or reading in response to access control of a magnetic tape device by a higher-level device (1). Management information creating means (3) for creating management information for each block including at least a block address, the number of data, and the number of sectors used based on the write data transferred in 2)
Writing means (4) for writing the write data to the sectors constituting the designated block after writing the block information in the predetermined medium sector; and, at the time of reading, the designated block from the block management information read from the medium. Reading means (5) for reading a medium by knowing a block address, the number of data and the number of sectors used; and an access control method for an optical disk device.