JPH07121476A - Target device - Google Patents

Abstract

PURPOSE:To provide a target device which is capable of improving data transfer processing efficiency. CONSTITUTION:Parameter groups are made into groups and are held so that the numbers may be designated corresponding to each parameter in the memory 33 within a target device 3. A main control part 32 accesses to the contents of the memory 33 by a parameter unit based on a READBUFFER command/ WRITEBUFFER command including the number information (page numbers and offset values) of the desired parameter from an initiator device 2 to be inputted through an SCSI bus 1 and a command control part 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an initiator device and an S
The present invention relates to a target device connected via an interface such as CSI, and particularly to a target device in which a value of a parameter is read or written by an initiator device.

[0002]

2. Description of the Related Art Conventionally, SCSI (Small Computer Syste) has been used as an input / output interface around a small computer.
m Interface = small computer system interface) is known. In recent years,
SCSI-2 (ANSI (American National Standards Institute) X3T 9.2 / 86-
10) is defined. Documents of the Japanese version of this SCSI-2 include "Small Computer System Interface (SCSI-2), technical data, Japan Business Opportunity Association, published July 20, 1992. This SC
According to the definition of SI-2, a conventional magnetic disk device, optical disk device,
In addition to the printer device, a communication device such as a facsimile device adapter can be adopted. Then, a computer system conforming to the SCSI-2 standard is realized.

The initiator and the target are SC
A system disclosed in Japanese Patent Laid-Open No. 5-1369285 is known as a system configured by being connected via an SI bus. In this publication, a host computer having a SCSI initiator function and a communication adapter having a data communication function and a SCSI target function via a communication line are connected to a SCSI bus, and the host computer communicates with each other. When receiving data from the adapter, periodically execute a SCSI command to check whether there is data to communicate with the communication adapter, and if there is data, execute a SCSI command to check the data length and then receive the data. A bidirectional data communication is performed by executing a SCSI command to execute.

In SCSI-2 described above, an initiator can generally read (read) or write (write) parameters in a target. Specifically, in the command phase, the initiator sends a read or write command to the target using a mode sense (MODE SENSE) command or a mode select (MODE SELECT) command. Then, in the data phase, the data is transferred from the initiator to the target at the time of writing, while the data is transferred from the target to the initiator at the time of reading.

SCSI-which enables such data transfer
In No. 2, data (parameters) transferred in the data phase is transferred in units called pages, but the number of pages (that is, data) that the user can freely use is limited to 30. Has been done.

[0006]

As described above, in the conventional parameter read / write method using the MODE SENSE command / MODE SELECT command in the above SCSI, the number of data (parameters) transferred in the data phase is used. Is limited to 30, so
When the number of parameters on the target side exceeds 30 and is very large, it is necessary to block a predetermined number of parameters and perform data transfer in block units.

The above problems will be described with reference to specific examples.
Here, it is assumed that the number of parameters is 3000. In this case, since the number of data that the user can freely use is 30, it is necessary to block 3000/30 = 100 data as one page unit into 30 pages. FIG. 6 shows how this block is created. In FIG. 6, P
0, P1, ..., P29 indicate pages, respectively, and 0 to 99 on the page P0 indicate the number of parameters (here, 100).

In FIG. 6, when reading the parameters of the shaded area of page P0, the initiator uses the MODE SENSE command and the MODE SELECT command including reading of the entire page P0 in the command phase. Send a read command to the target. After that, the data phase is entered. Then, since the entire page P0 from the target is transferred to the initiator in the data phase, the initiator can read the parameters in the hatched area from within the transferred page P0.

On the other hand, when it is desired to rewrite the parameters of the hatched area of the page P0, the initiator includes a statement that the entire page P0 is written in the command phase.
Send a write command to the target using MODESENSE and MODE SELECT commands. Then, the initiator shifts to the data phase and transfers the page P0 having the new content to the target. As a result, in the target, the page P0 before the change is the transferred page P0.
Updated to 0.

As described above, conventionally, it was impossible to read / write in units of parameters, and it was necessary to read / write in units of pages having 100 parameters. For this reason, even if it is desired to access one parameter, the data must be transferred in page units, which requires a large amount of transfer time, resulting in poor data transfer processing efficiency.

An object of the present invention is to provide a target device capable of improving the data transfer processing efficiency.

[0012]

According to the present invention, a target device (FIG. 1) which is connected to an initiator device (2 in FIG. 1) via a predetermined interface (1 in FIG. 1) and whose parameter value is rewritten by the initiator device (FIG. 1), 3), storage means (33 in FIG. 1) for holding a parameter group so that addresses can be designated corresponding to the respective parameters, and desired parameters from the initiator device input via the predetermined interface. When the read buffer command or the write buffer command including the address information is received, the storage means is provided with access means (32 in FIG. 1) for accessing the parameter corresponding to the address information.

[0013]

According to the present invention, a parameter group is stored in the storage means so that addresses can be designated corresponding to the respective parameters, and the access means stores the desired parameter from the initiator device input through the predetermined interface. When the read buffer command or the write buffer command including the address information is received, the storage unit is accessed for the parameter corresponding to the address information. Therefore,
Even if there are a plurality of parameters, the parameters corresponding to the address information can be accessed in parameter units.

[0014]

Embodiments of the present invention will be described in detail below with reference to FIGS.

FIG. 1 is a block diagram showing an embodiment of a computer system having a target device according to the present invention. In the figure, an initiator device 2 and a target device 3 are connected to a SCSI bus 1.

In the initiator device 2, the main controller 2
Reference numeral 1 gives an instruction to read or write a parameter (hereinafter referred to as read / write) to the read / write processing unit 22. The read / write processing unit 22 creates a read buffer (READ BUFFER) command or a write buffer (WRITE BUFFER) command (hereinafter referred to as a READ BUFFER command / WRITE BUFFER command) according to a preset format (for details of this, see below). Will be described later),
It is passed to the command control unit 23. In the command control unit 23,
According to each phase of SCSI, the target device 3 and S
Data is transmitted and received via the CSI bus 1.

The READ BUFFER command / WRITE BUFFER command is originally used for testing the reliability of the target memory via the SCSI bus.
These commands are also MODE SENSE command and MODE SEL
Like the ECT command, it was previously used to access page units.

In the target device 3, the command control unit 31 transmits / receives data via the initiator device 2 and the SCSI bus 1 according to each phase of SCSI. The main control unit 32 accesses the memory 33 based on the READ BUFFER command / WRITE BUFFER command received from the command control unit 31 and notifies the command control unit 31 of the access result. The memory 33 holds a parameter group so that addresses can be designated corresponding to the respective parameters (the details will be described later).

Correspondence between the constituent elements of the invention shown in claim 1 and the constituent elements shown in FIG. 1 will be described below. The initiator device corresponds to the initiator device 2, the target device corresponds to the target device 3,
The predetermined interface corresponds to the SCSI bus 1, the storage means corresponds to the memory 33, and the access means corresponds to the main control unit 33.

FIG. 2 shows a holding format of the parameter group held in the memory 33. Here, the case where the same parameter group as the conventional parameter group shown in FIG. 6 is stored will be described. In the example shown in FIG. 2, the memory 33
A group number area 210, which is a level representing a group unit, and a parameter area 220, which is a level representing a parameter unit included in a group, are formed in the area. In the group area 210, reference numerals 0, 1, 2, ..., 29
Indicates a group number, and in the area corresponding to group 0 in the parameter area 220, codes 0, 1, 2,
..., 99 are offset values. Similarly, in the areas corresponding to groups 2, ..., 29, 0, 1,
Offset values of 2, ..., 99 are associated. Parameters are stored in the area corresponding to each offset value. That is, in the example shown in FIG. 2, 100-unit parameters are grouped into 30 groups. Of course, when grouping, it is not necessary to make the number of parameters in each group the same.

By specifying the group number and the offset value, it is possible to perform read / write access of specific parameters. For example, to perform read / write access to the shaded area shown in FIG. 2, by designating group 0 as the group number and “1” as the offset value, the area corresponding to the offset value is designated. You can access the parameters.

The memory 33 in the target device 3 is set as a logical unit defined in SCSI-2 (that is, logical unit = physical or virtual peripheral device addressable via the target), and this logical unit is used. The unit is given a logical unit number uniquely determined in the target device 3 and defined in the above SCSI-2 (that is, a logical unit number = a 3-bit identifier coded to distinguish logical units). It

FIG. 3 shows the SCSI-2 READ BUFFER.
The format of the command / WRITE BUFFER command is shown. The format shown in FIG. 3 is SCSI-2.
It is similar to the content defined in. In this embodiment, the buffer ID is assigned to the group number designation (0 to 29 in this example), and the buffer offset is designated to the offset value for each group (0 to 9 in this example).
9). As the operation code, "3Ch" is used for reading and "3Ch" for writing.
Bh ”is designated. As the logical unit number, the logical unit number indicating the logical unit corresponding to the memory 33 in the target device 3 is designated.

Next, the READ BUFFER command /
Parameter read / write processing using the WRITE BUFFER command will be described with reference to FIGS. 4 and 5.
4 shows a sequence diagram of the parameter read processing operation, and FIG. 5 shows a sequence diagram of the parameter write processing operation.

First, the read process will be described. Here, the processing for reading the parameters of the shaded area shown in FIG. 2 will be described.

In the initiator device 2, the main controller 2
1 instructs the read / write processing unit 22 to read the parameters in the shaded area, the read / write processing unit 22 uses the READ BUFFER command of the format shown in FIG. 3 as shown in FIG. , The operation code is “3Ch”, the logical unit number is “logical unit number indicating the logical unit corresponding to the memory 33”, the mode is “vendor mode”, and the buffer ID is “parameter group number (group number in this example). The value of 0 indicating 0 is set to the buffer offset, and the offset value for each group (in this example, the value of 1 indicating offset value 1) is set (S410).

By setting the vendor mode as the mode, the command contents can be arbitrarily used. That is, the contents of the buffer ID and the buffer offset are not bound by the above SCSI-2 specifications.

READ BUF in which each value is set as described above
Since the FER command is passed to the command control unit 23, the command control unit 23 transfers the passed READ BUFFER command to the target device 3 in accordance with the command phase (S420). After that, the command control unit 23 shifts to the data phase and waits for reception of parameters from the target device 3.

On the other hand, in the target device 3, the command control section 31 reads the READ B from the initiator device 2 input via the SCSI bus 1 in the command phase.
The UFFER command is received (S430) and passed to the main controller 32. The main controller 32 retrieves the corresponding parameter from the data stored in the memory 33 based on the buffer ID and the buffer offset in the received READ BUFFER command (S440). In this case, since the group number = 0 and the offset value = 1, the parameters in the shaded area in the example shown in FIG. 2 are searched. The parameters retrieved in this way are passed from the main controller 32 to the command controller 31. Then, the command control 31 shifts to the data phase and transfers the parameter passed from the main control unit 32 to the initiator device 2 (S450).

Then, in the initiator device 2, the command control unit 23 which is in transition to the data phase,
The parameters received from the target device 3 via the SCSI bus 1 are received (S460). This parameter is input through the read / write processing unit 22 to the main control unit 21 which is the processing request destination.

After that, the initiator device 2 and the target device 3 follow the phase defined by SCSI.

Next, the write processing will be described. Here, a process for writing the parameters of the shaded area shown in FIG. 2 will be described.

In the initiator device 2, the main controller 2
When 1 instructs the read / write processing unit 22 to write (rewrite) the parameters in the shaded area, as shown in FIG. 5, the read / write processing unit 22
In the WRITE BUFFER command of the format shown in FIG. 3, each value is set to the operation code, the logical unit number, the mode, the buffer ID and the buffer offset, as in the case of the above read (S510). In this case, the operation code is set to "3Bh", and other than that, the same contents as the contents set in the case of the above read are set.

WRITE BU in which each value is set as described above
Since the FFER command is delivered to the command control unit 23, the command control unit 23 sends the delivered WRITE BUFFER command to the target device 3 in accordance with the command phase (S520). After that, the command control unit 23 shifts to the data phase and transmits the parameter value to be written to the target device 3 (S530).

On the other hand, in the target device 3, the command control unit 31 receives the WRITE BUFFER command input from the initiator device 2 through the SCSI bus 1 (S540) and passes it to the main control unit 32. After that, the process proceeds to the data phase, the parameter value from the initiator device 2 input through the SCSI bus 1 is received (S550), and the parameter value is passed to the main control unit 32.

The main controller 32 retrieves the corresponding parameter from the data stored in the memory 33 based on the buffer ID and the buffer offset in the WRITE BUFFER command received from the command controller 31 (S560), The retrieved parameter is changed (rewritten) to the value of the parameter received from the command control unit 31 (S570).

After that, the initiator device 2 and the target device 3 follow the phase defined by SCSI.

In the above-mentioned embodiment, the parameter group is held in a holding format as shown in FIG. 2, so-called a two-dimensional array, but the present invention is not limited to this, and the following may be performed. good. That is, the group 0, the group 1, ..., The group 29 may be set as independent areas, and as described above, the desired parameter may be designated by designating the group number and the offset value. In other words, it means that there is a hierarchy at the level of group and the lower level of the parameters included in the group.

As described above, according to the present embodiment, the parameter group is grouped in the memory 33 in the target device 3 and held so that addresses can be designated corresponding to the respective parameters, and the main controller 32 is a READ BUFFER command / WRIT which includes address information (page number and offset value) of a desired parameter from the initiator device 2 which is input via the SCSI bus 1 and the command control unit 31.
Since the parameter stored in the memory 33 is accessed based on the E BUFFER command, it can be freely used by the user as defined in the conventional case of using the MODE SENSE command / MODE SELECT command. The number of data (parameters) that can be set by the READ BUFFER command / WRITE BUFFER command can be accessed without being restricted by the number of data (that is, 30).

Therefore, the read / write access unit of the parameter can be set as the parameter unit.
The data transfer time can be shortened.

[0041]

As described in detail above, according to the present invention, a group of parameters is held in the storage means so that addresses can be designated corresponding to the respective parameters, and the access means inputs it through a predetermined interface. When a read buffer command or a write buffer command including address information of a desired parameter is received from the initiated initiator device,
Since the parameter corresponding to the address information is accessed to the storage means, it is possible to access in parameter units.

Moreover, even if the access is to one of a plurality of parameters, and in the conventional case where the access must be made for each block unit having a predetermined number of parameters, the present invention is applicable. According to this, it is possible to access the corresponding parameter in units of parameters, so that data can be transferred in units of parameters and the data transfer time can be shortened as compared with the related art.

From the above, there is an advantage that it is possible to provide a target device which improves the data transfer processing efficiency.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a computer system having a target device according to the present invention.

FIG. 2 is a diagram for explaining a holding format for holding a parameter group.

FIG. 3 is a diagram showing an example of a format of a READ BUFFER command and a WRITE BUFFER command.

FIG. 4 is a sequence diagram showing a parameter read processing operation using a READ BUFFER command.

FIG. 5 is a sequence diagram showing a parameter write processing operation using a WRITE BUFFER command.

FIG. 6 is a diagram for explaining a conventional parameter read / write operation.

[Explanation of symbols]

1 ... SCSI bus, 2 ... Initiator device, 3 ... Target device, 21, 32 ... Main control unit, 22 ... Reader / write processing unit, 23, 31 ... Command control unit, 33 ... Memory.

Claims (1)

[Claims] 1. In a target device, which is connected to an initiator device through a predetermined interface and the value of a parameter is rewritten by the initiator device, a storage means for holding a parameter group so that an address can be designated corresponding to each parameter. When a read buffer command or a write buffer command including address information of a desired parameter is received from the initiator device that is input via the predetermined interface, the parameter corresponding to the address information is accessed to the storage unit. And a target access device for controlling the target device.