JP2577614B2 - Information recording / reproducing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an information recording / reproducing method for recording / reproducing predetermined information on / from an optical card based on a command from a host computer via SCSI.

[Background Art] SCSI (Small Computer System Interface) is an interface that connects a small computer manufactured by Sugart Co. of the United States and its peripheral device SASI (Small Computer System Interface).
ace) was standardized by ANSI (American National Standards Institute) X3.131-1986, and was rewritten. It handles 8-bit parallel signals, has a data transmission rate of 1.5 Mbytes / sec, and has a multi-tax system that controls up to seven simultaneously. You can do it.

The range of the interface rules defined by the ANSI is the following five points.

(1) Types of interface signals and their definitions, signal transfer timings (2) Protocols that define the operation sequence as an interface, definitions of each phase, etc. (3) Physical interface conditions such as cable specifications and connector specifications, transmission systems (4) Command system for executing various controls and data transfer of peripheral devices, command format and function of each command (5) Status byte format for informing the host computer of the command execution result, and This is the structure of sense data that informs an abnormal state in the process.

The command system in the above (4) is as follows.

SCSI commands are divided into eight types of groups.
The first byte of the CDB is an operation code. The upper 3 bits of the operation code specify a group code, and the lower 5 bits specify a command code (code indicating a command type) for each group.

The length of the CDB is defined as follows for each group.

(1) Group 0: 6 bytes (2) Group 1: 10 bytes (3) Groups 2 to 4: Reserved (4) Group 5: 12 bytes (5) Group 6 to 7: Vendor unique The CDBs of groups 6 and 7 are commands that can be uniquely defined by SCSI devices.

In each command, the logical block address is such that fixed-length data blocks are continuously arranged on the logical unit.

FIG. 8 is a diagram showing a configuration example of a logical block in a hard disk device.

In FIG. 8, the data block of cylinder = 0 and sector = 0 is set to logical block address = 0, and the sector,
Each time the track and cylinder are increased by one, the logical block address is increased by one.

The advantage of logical block addressing is that the initiator (host computer) accesses the data by designating the logical block address of the first data block and the number of processing blocks, so there is no need to be aware of the physical structure. is there. Therefore, when the above-mentioned logical block addressing is used, when devices having different numbers of cylinders, tracks, and sectors are connected to each other,
It can be operated with the same software.

In SCSI, a logical unit number (hereinafter referred to as "LU
N ") to physical devices,
Also, it may be provided to a virtual device.

FIG. 9 is a diagram showing a general example of a SCSI system configuration.

As a logical unit, usually, a physical device such as a hard disk is often used as shown in FIG.

By the way, the above SCSI usually has eight logical units of 0 to 7, and can use the extended message to have 2048 logical units.

On the other hand, an optical card has thousands of tracks, and its information capacity is several megabytes. For this reason, when an optical card is used, the area of the optical card is used in accordance with the type of information, such as using the area A for the image information and the area B for the document information, depending on the application. When managed, the required information can be searched at high speed when reproducing it. Therefore,
In order to search at high speed, area division is necessary as described above.

[Problems to be Solved by the Invention] In the optical card, when the track number is not preformatted, random writing cannot be performed, and only sequential writing is possible, the following problems are raised. Can be

The command is usually 6 bytes or more. FIG. 10 shows an example of a write command of group 0, and FIG. 11 shows an example of an extended write command of group 1. As shown in FIG. 10 and FIG. 11, writing is performed by designating a LUN 100 and a logical block address 101 and a transfer length 102, respectively.

However, the track number is not preformatted, and write-once sequential writing is generally performed on an optical card. However, the last track (hereinafter referred to as “EOT”) in which the logical block address 101 in the write command has already been recorded. ), The processing method is not clear.

That is, when information is recorded ignoring the contents indicated by the logical block address 101, the recording operation is always performed, but the logical block address 101 included in the read command in the reproducing operation is the actual recorded address. It is usually impossible to match with

Also, in the above method, if the logical address at the time of recording / reproducing is to be matched, the control software becomes complicated, and when the optical card is ejected from the information recording / reproducing device and reloaded, the control becomes impossible. There's a problem.

On the other hand, if the transfer length 102 during the write command is large,
When data to be written is transferred after a write command from the host computer via the host adapter, the transfer time is proportional to the transfer length 102. However,
If the transfer block address 102 is not EOT + 1, there is a problem that the transfer time is wasted.

Further, when the execution of the command is abnormally terminated, the optical card transmits the sense data 120 indicating the termination status of the command.
(Shown in Fig. 12). The first byte of the sense data 120 includes an error class for identifying the format.
When the error class 121 = 7, it indicates that the sense data 120 is in the extended format. At this time, the sense data 120 indicates that an error has occurred at the specified address, but there is a problem that the relationship with the EOT cannot be known.

A problem similar to the above-described problem in writing also occurs in reading.

That is, in the optical card, the track number is not preformatted, and the sequential write and the EOT
If random reading is possible within the range, there is the following problem.

First, it is assumed that the command is usually 6 bytes or more, the read command of group 0 is the same as the write command shown in FIG. 10, and the extended read command of group 1 is
It is assumed that this is the same as the write command shown in FIG. Both read commands specify a LUN 100, specify a logical block address 101 and a transfer length 102, and perform a read operation. However, the track number is not pre-formatted, and random read is generally used in an optical card.
When 1 indicates a track equal to or more than the last track already recorded, there is a problem that the processing method is not clear.

If the transfer length 102 during the write command is large, the host computer reads the track to be read after the read command via the host adapter,
When read and the data is transferred, the transfer time is proportional to the transfer length 102. However, logical block address 1
If 02 is greater than or equal to EOT, there is a problem that the seek operation time is wasted time.

Then, when the execution of the command ends abnormally, the optical card sends the sense data 120 (first
2). The first byte of the sense data 120 includes an error class for identifying the format. When the error class 121 = 7, it indicates that the sense data 120 is in the extended format. At this time, in the sense data 120,
You can see that an error occurred at the specified address, but EO
There is a problem that the relationship with T cannot be known.

The present invention provides an information recording / reproducing method capable of eliminating a waste of execution time and quickly executing a command when recording or reproducing predetermined information on an optical card based on a command from a host computer via SCSI. The purpose is to do so.

[Means for Solving the Problems] According to the present invention, write data is received only when the logical block address in the write command is EOT + 1, and otherwise, a check condition is returned. In addition, information indicating that access has been made by means other than EOT + 1 and EOT number information are added to the section.

In addition, the present invention performs a read operation only when the logical block address in the read command is equal to or higher than EOT, returns a check condition otherwise, and sets the vendor unique portion in the extended sense data 120 to include the EOT or higher. And EOT number information.

[Operation] The present invention receives write data only when the logical block address in the write command is ETO + 1, returns a check condition otherwise, and adds a check condition to the vendor unique portion in the extended sense data 120, except for EOT + 1. Since information indicating that access has been made and EOT number information are added, waste of execution time can be eliminated, and commands can be executed quickly.

In addition, the present invention performs a read operation only when the logical block address in the read command is equal to or higher than EOT, returns a check condition otherwise, and sets the vendor unique portion in the extended sense data 120 to include the EOT or higher. Since the information indicating that the access has been made and the EOT number information are added, waste of execution time can be eliminated, and the command can be executed quickly.

Embodiment First, the basic configuration of an optical card and the configuration of an optical head will be described. The same members are given the same numbers.

FIG. 3 is a plan view showing an example of an optical card used in the present invention.

FIG. 4 is an enlarged view of a portion indicated by A in FIG.

The optical card 1 has a linear tracking track 5 (5
−0, 5-1, 5-2,...) Are arranged at equal intervals. The data recording unit 4 (4-0, 4-1, 4-4) for recording information between adjacent tracking tracks.
2,...) Are provided. That is, the optical card 1
Has a data recording section 4 in all of the space between one tracking track and an adjacent tracking track.

As shown in FIG. 4, a G mark 7 is provided between the tracking tracks 5-1 and 5-2. This G
The mark 7 is a mark for determining a reference track, and is arranged at a predetermined location on the optical card 1 by preformatting. On the extension of the data recording unit 4 where the G mark 7 exists, a medium type pattern 8 as an auxiliary data unit
Are preformatted or recorded with light spots. The medium type pattern 8 indicates the identification of the optical card 1 and records information such as a variable tone method, a data capacity per track, and the total number of tracks.

FIG. 5 is an explanatory diagram relating to a configuration of an optical head unit of the information recording / reproducing apparatus.

FIG. 6 is an explanatory diagram showing a light beam applied to the optical card 1. FIG.

 FIG. 7 is an explanatory diagram showing a configuration of the photodetector.

A light beam generated by a light source 27 such as a semiconductor laser is collimated by a collimator lens 28 and divided into 30 beams by a diffraction grating 30. These light beams are imaged by the objective lens 26 on the tracking tracks 5-1 and 5-2 of the optical card 1 and the data recording section 4-1 as shown in FIG. 5, for example, and the beam spots S1, S2, Form S3. Here, the optical card 1 is moved in the direction of arrow R shown in FIG. 5 by driving means (not shown), and the optical card 1 is scanned by the beam spots S1 to S3 in the direction in which the tracking track extends.

The reflected light from the beam spots S1, S2 and S3 is
Again, is reflected by the beam splitter 20, and is projected by the condenser lens system 21 to the photodetectors 22, 23, and 24, respectively. The condenser lens system 21 is an astigmatism system, and performs autofocus by a known astigmatism method. These photodetectors 22 to 24 are arranged in the arrangement shown in FIG. 7, and the photodetector 23 is divided into four parts A, B, C and D.

The prism 29 shown in FIG. 5 is a prism that converts the cross-sectional distribution of the collimated light beam emitted from the semiconductor laser from an ellipse to a circle.

 Next, an operation of recording information on the optical card 1 will be described.

For example, when information is recorded in the data recording unit 4-1,
First, the beam spots S1, S2, and S3 are irradiated on the tracking track 5-1, the data recording unit 4-1, and the tracking track 5-2, respectively. These beam spots are
By moving the optical card 1, scanning is performed in the direction of arrow F shown in FIG. The reflected light from beam spot S1 is a photodetector
22 and the reflected light from beam spot S3 is a photodetector
24, and a tracking signal is detected by a so-called three-beam method.

That is, when the beam spots S1 and S3 deviate from the tracking tracks 5-1 and 5-2, the photodetectors 22 and 24 are shifted.
The tracking signal is obtained by comparing the signals from the light receiving surfaces (tracking tracks 5-1 and 5-2). On the basis of this tracking signal, tracking means (not shown in FIG.
The beam splits S1, S2, S3 are moved in a direction perpendicular to the scanning direction (D shown in FIG.
Direction), and automatic tracking (AT) is performed.

Then, along the tracking tracks 5-1 and 5-2, the data recording unit 4-1 is formed by the beam split S2.
The recording pit 31 is recorded accurately.

 Next, a write operation in the present invention will be described.

FIG. 1A is a flowchart showing the operation of the control program during the recording operation in the present invention.

First, when a write command is received (S1), a logical address is checked (S2). Here, for the sake of simplicity, a description of checking the LUN 100 and the transfer length 102 will be omitted.

Considering the check of the logical block address 101 taking the case of one sector per track as an example, the logical block address 101 and “EOT + 1” in the command may be checked. "EOT + 1" is the logical block address 1 in the command
If different from 01, error information is set in the extended sense data 120 (S3).

FIG. 1 (2) is a flowchart more specifically showing the operation (S3) of setting error information in the extended sense data.

In the above case, since the logical address is larger than “EOT + 1” (S31), 6 bytes from 0 byte of the extended sense data 120
An error class 121, an error code 122, a segment number 123, an information byte 124, and the like according to the SCSI standard are set up to the byte. Further, the additional sense data length 125 of the seventh byte indicates information indicating, for example, 3 bytes (for example, a code of 03h). Next, a coat indicating that a reading operation exceeding “EOT + 1” was performed (for example, 20
h) is written to the 8th byte (S32).

On the other hand, if the logical block address 101 is equal to or less than "EOT + 1" (S31), a code (for example, 21h) indicating that writing has been completed is stored (S33).

Next, the EOT number is stored from the 9th byte to the 10th byte (S34). In this case, the MSB may be set at the ninth byte or the MSB may be set at the tenth byte.

Although the EOT number is handled as a number that can be accommodated in 2 bytes here, it is sufficient to secure the number of bytes that can store the maximum number of the logical block addresses 101.
The additional sense data length 125 at the byte may be changed.

 The same applies to the case where the EOT number is handled in ASCII.

When the setting of the extended sense data 120 is completed, a check condition status is returned to the host computer (S4).

The computer receives the check condition status, knows the abnormal termination of the command, issues a request sense data command to find the cause of the error, receives the extended sense data 120 from the optical card 1, and knows the cause of the error.

On the other hand, in FIG. 1 (1), the logical address is "EOT
If it is equal to “+1” (S2), write data is received (S2).
5) Writing is performed (S6), and a good status is transmitted to the host computer (S7).

FIG. 2 (1) is a flowchart showing the operation of the control program at the time of the reproducing operation in the present invention.

First, when a read command is received (S1a), a logical address is checked (S2a). Here, for the sake of simplicity, a description of checking the LUN 100 and the transfer length 102 will be omitted.

Considering the check of the logical block address 101 taking the case of one sector per track as an example, the logical block address 101 in the command and "EOT" may be checked.
If “EOT” is smaller than the logical block address 101 in the command, error information is set in the extended sense data 120 (S3a).

FIG. 2 (2) is a flowchart more specifically showing the operation (S3a) of setting error information in the extended sense data.

In the above case, since the logical address is larger than “EOT + 1” (S31), 6 bytes from 0 byte of the extended sense data 120
An error class 121, an error code 122, a segment number 123, an information byte 124, and the like according to the SCSI standard are set up to the byte. Further, the additional sense data length 125 of the seventh byte indicates information indicating, for example, 3 bytes (for example, a code of 03h). Next, a code (for example, 20) indicating that a reading operation exceeding "EOT" was performed.
h) is written to the 8th byte (S32).

Next, the EOT number is stored from the 9th byte to the 10th byte (S34). In this case, the MSB may be set at the ninth byte or the MSB may be set at the tenth byte.

Although the EOT number is treated as a number that can be accommodated in 2 bytes here, it is sufficient to secure the number of bytes that can store the maximum number of the logical block addresses 101.
The additional sense data length 125 at the byte may be changed.

 The same applies to the case where the EOT number is handled in ASCII.

When the setting of the extended sense data 120 is completed, a check condition status is returned to the host computer (S4a).

The computer receives the check condition status, knows the abnormal termination of the command, issues a request sense data command to find the cause of the error, receives the extended sense data 120 from the optical card 1, and knows the cause of the error.

On the other hand, in FIG. 2A, the logical address is "EO".
If it is equal to "T" (S2a), read (S5a), transmit read data (S6a), and transmit a good status to the host computer (S7a).

[Effects of the Invention] According to the present invention, when recording or reproducing predetermined information on or from an optical card based on a command from a host computer via SCSI, waste of execution time can be eliminated and commands can be executed quickly. It has the effect of.

Further, according to the present invention, since the EOT information is added to the vendor unique portion of the extended sense data, the EOT number can be known by the request sense data command, and the host computer that issues the write command or the read command can read the EOT number. Has the effect of reducing the burden of software production.

[Brief description of the drawings]

FIG. 1A is a flowchart showing the operation of the control program during the recording operation in the present invention. FIG. 1 (2) is a flowchart showing the operation of the extended sense data set shown in FIG. 1 (1). FIG. 2 (1) is a flowchart showing the operation of the control program at the time of the reproducing operation in the present invention. FIG. 2 (2) is a flowchart showing the operation of the extended sense data set shown in FIG. 2 (1). FIG. 3 is a schematic plan view showing an example of the optical card. FIG. 4 is a partially enlarged view of a portion A in FIG. FIG. 5 is an explanatory diagram relating to a configuration of an optical head unit of the information recording / reproducing apparatus. FIG. 6 is an explanatory view showing a light beam irradiated on the optical card. FIG. 7 is an explanatory diagram of an operation of the information recording / reproducing apparatus recording on an optical card. FIG. 8 is a diagram showing a configuration example of a logical block in a hard disk device. FIG. 9 is a configuration diagram of a general SCSI system. FIG. 10 is a diagram showing a configuration of a write command or a read command. FIG. 11 is a diagram showing a configuration of an extended write command or an extended read command. FIG. 12 is a diagram showing a configuration of extended sense data. 1, optical card, 4, 4-1 and 4-2, data recording section, 5, 5-0 to 5-2, tracking track, 1
0, 11 ... command block, 100, 110 ... logical unit number, 101, 111 ... logical block address, 102, 112
…… Transfer data length, 120 …… Extended sense data, 121 ……
Error class, 122: Error code, 123: Segment number, 124: Information byte, 125: Additional write data length.

Claims (6)

(57) [Claims] 1. A system for recording and reproducing predetermined information on an optical card based on a command from a host computer via SCSI, wherein a track number in the optical card is not added in advance to a track in the optical card. When a command indicating that information is to be recorded via the SCSI is transmitted, the next track after the last track of the already recorded track is recorded only when the logical block address to be recorded in the command indicates the track. An error information request command from the host computer while returning a check command, storing error information in the device controller, and providing an error information request command from the host computer. 2. The information recording / reproducing method according to claim 1, wherein the error information to be stored includes information indicating that access has been made beyond the last track, and a number of the last track. method. 3. The method according to claim 1, wherein the error information to be stored is 8 bits of extended sense data.
An information recording / reproducing method characterized by being stored after a byte. 4. A system for recording and reproducing predetermined information on an optical card based on a command from a host computer via SCSI, wherein a track number in the optical card is not assigned in advance, When a command indicating that information is to be reproduced via the SCSI is transmitted, the tracks within the last track of the already recorded tracks are reproduced only when the logical block address to be reproduced in the command indicates. Otherwise, a check command is returned, error information is stored in the device controller, and an error information request command from the host computer is prepared. 5. The information according to claim 4, wherein the error information to be stored includes information indicating that reproduction is attempted beyond the last track, and the number of the last track. Recording and playback method. 6. The method according to claim 4, wherein the error information to be stored is an extended type sense data of 8 bits.
An information recording / reproducing method characterized by being stored after a byte.