JP3456234B2 - Target device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field 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 more particularly, to a target device in which parameter values are read or written by an initiator device. 2. Description of the Related Art Conventionally, SCSI (Small Computer System) has been used as an input / output interface around a small computer.
m Interface = small computer system interface). In recent years,
SCSI-2 (ANSI (American Standards Association) X3T 9.2 / 86-
10) is defined. The literature of the Japanese version of SCSI-2 is "Small Computer System Interface (SCSI-2), Technical Data, Japan Business Opportunities Association, published on July 20, 1992."
According to the definition of SI-2, as a target of the SISC device, a conventional magnetic disk device, an optical disk device,
In addition to the printer device, it is possible to employ a communication device such as a facsimile device adapter. Then, a computer system based on the SCSI-2 protocol is realized. Note that the initiator and the target are SC
As a system connected via an SI bus, a system described in Japanese Patent Application Laid-Open No. Hei 5-1369285 is known. In this publication, a host computer having a SCSI initiator function and a communication adapter having a data communication function via a communication line and a SCSI target function are connected to a SCSI bus. When receiving data from the adapter, the communication adapter periodically executes a SCSI command to check whether there is data to communicate, and if there is data, executes a SCSI command to check the data length, and then receives data. By executing the SCSI command, bi-directional data communication is performed. [0004] In the above-described SCSI-2, 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. Thereafter, the process proceeds to the data phase, in which data is transferred from the initiator to the target in the case of writing, while data is transferred from the target to the initiator in the case of reading. [0005] SCSI-capable of such data transfer
In 2, the data (parameters) transferred in the data phase are transferred in units called pages, but the number of pages (ie, data) that can be freely used by the user is limited to 30. Have been. [0006] As described above, in the conventional parameter read / write method using the MODE SENSE command / MODE SELECT command in the SCSI, data (parameters) transferred in the data phase is used. ) Is limited to 30.
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 to 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 can be freely used by the user is 30, 3000/30 = 100 data must be divided into 30 pages in units of one page. FIG. 6 shows this block. In FIG.
0, P1,..., P29 each indicate a page, and 0 to 99 in the page P0 indicate the number of parameters (here, 100). In FIG. 6, when reading parameters in a shaded area of page P0, the initiator uses a MODE SENSE command and a MODE SELECT command including a command to read the entire page P0 in a command phase. Sends a read command to the target. Then, it moves to the data phase. Then, since the entire page P0 from the target is transferred to the initiator in the data phase, the initiator can read the parameters of the area indicated by the diagonal lines from the transferred page P0. On the other hand, when it is desired to rewrite the parameters of the area of the page P0 indicated by the diagonal lines, the initiator includes writing the entire page P0 in the command phase.
Send a write command to the target using the MODESENSE and MODE SELECT commands. Then, the initiator shifts to the data phase and transfers the page P0 of the new content to the target. As a result, in the target, the page P0 before the change is
Updated to 0. As described above, conventionally, reading / writing cannot be performed in units of parameters, and reading / writing must be performed 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, so that a long transfer time is required and the data transfer processing efficiency is poor. An object of the present invention is to provide a target device that can improve the efficiency of data transfer processing. In order to achieve the above object, the present invention is connected to an initiator device (2 in FIG. 1) via a predetermined interface (1 in FIG. 1), and is controlled by the initiator device. In a target device (3 in FIG. 1) that reads or writes values of grouped parameter groups in units of groups, group information for specifying a group to which a parameter belongs, and a parameter for specifying the position of the parameter in the group Storage means (3 in FIG. 1) for storing information and information in association with the parameter.
And 3) receiving buffer commands including group information and parameter information corresponding to desired parameters from the initiator device input via the predetermined interface, based on the received group information and parameter information. And an access means (32 in FIG. 1) for reading or writing a desired parameter stored in the memory. According to the present invention, a parameter group is held in the storage means so as to be able to specify an address corresponding to each parameter, and the access means is provided with a desired parameter from the initiator device input via a predetermined interface. When a read buffer command or a write buffer command including the address information of the parameter is received, the storage unit is accessed for the parameter corresponding to the address information. Therefore,
Even when there are a plurality of parameters, the parameters corresponding to the address information can be accessed in parameter units. An embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a block diagram showing one embodiment of a computer system having a target device according to the present invention. In FIG. 1, an initiator device 2 and a target device 3 are connected to a SCSI bus 1. In the initiator device 2, the main control unit 2
Numeral 1 gives a read / write (hereinafter, read / write) instruction of a parameter 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) in accordance with a preset format (for details of this, refer to FIG. Will be described later),
It is passed to the command control unit 23. In the command control unit 23,
The target device 3 and the S
Data is transmitted and received via the CSI bus 1. The READ BUFFER command / WRITE BUFFER command is originally used to test 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 has been used to access pages in the past. In the target device 3, the command control unit 31 sends and receives data to and from the initiator device 2 and the SCSI bus 1 in accordance with each SCSI phase. 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 an address can be designated corresponding to each parameter (the details will be described later). Here, the correspondence between the constituent elements of the invention described in claim 1 and the constituent elements shown in FIG. 1 will be described. 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 a parameter group held in the memory 33. Here, a 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.
In addition, a group number area 210 which is a level indicating a group unit and a parameter area 220 which is a level indicating a parameter unit included in the group are formed. In the group area 210, reference numerals 0, 1, 2,.
Indicates a group number. In an area corresponding to group 0 in the parameter area 220, reference numerals 0, 1, 2,.
.., 99 indicate offset values. Similarly, in the areas corresponding to groups 2,.
2,..., 99 are associated with each other. A parameter is stored in an area corresponding to each offset value. That is, in the example shown in FIG. 2, the parameters in units of 100 are grouped into 30 groups. Of course, when grouping, it is not necessary to make the number of parameters of each group the same. By specifying a group number and an offset value, read / write access of a specific parameter can be performed. For example, when it is desired to execute read / write access to the shaded area shown in FIG. 2, by specifying group 0 as the group number and “1” as the offset value, the area corresponding to the offset value is designated. You can access parameters. The memory 33 in the target device 3 is set as a logical unit defined by the SCSI-2 (that is, a logical unit = a physical or virtual peripheral device addressable via a target). Each unit is uniquely assigned in the target device 3 and given a logical unit number defined in the SCSI-2 (that is, a logical unit number = a 3-bit identifier coded to distinguish the logical unit). You. FIG. 3 shows the READ BUFFER of the SCSI-2.
The format of the command / WRITE BUFFER command is shown. The format shown in FIG.
It is the same as the content defined in In this embodiment, a buffer ID is assigned to a group number designation (0 to 29 in this example), and a buffer offset is designated for each group by an offset value (0 to 9 in this example).
9). Note that the operation code is “3Ch” for read, and “3Ch” for write.
Bh "is specified. Further, a logical unit number indicating a logical unit corresponding to the memory 33 in the target device 3 is specified as the logical unit number. Next, the READ BUFFER command /
The parameter read / write processing using the WRITE BUFFER command will be described with reference to FIGS.
FIG. 4 is a sequence diagram of a parameter read processing operation, and FIG. 5 is a sequence diagram of a parameter write processing operation. First, the read processing will be described. Here, the processing in the case of reading the parameters of the shaded area shown in FIG. 2 will be described. In the initiator device 2, the main control unit 2
1 instructs the read / write processing unit 22 to read the parameters in the hatched area, as shown in FIG. 4, the read / write processing unit 22 executes the READ BUFFER command in the format 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 (in this example, group A value of 0 indicating 0 is set, and an offset value of each group (a value of 1 indicating an offset value of 1 in this example) is set as the buffer offset (S410) Note that the bender mode is set as the mode. As a result, the command contents can be arbitrarily used, that is, the buffer ID and the buffer off. The contents of the set are not bound by the above SCSI-2 rules [0028] The 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 according to the command phase (S420). After that, the command control unit 23 shifts to the data phase and waits for reception of a parameter 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.
Upon receiving the UFFER command (S430), the command is passed to the main control unit 32. The main control unit 32 searches the data stored in the memory 33 for a corresponding parameter 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, in the example shown in FIG. 2, the parameters in the shaded area are searched. The parameters searched in this way are passed from the main control unit 32 to the command control unit 31. Then, the command control 31 shifts to the data phase and transfers the parameters passed from the main control unit 32 to the initiator device 2 (S450). In the initiator device 2, the command control unit 23 that has shifted to the data phase is
The parameters received from the target device 3 via the SCSI bus 1 are received (S460). These parameters are input via the read / write processing unit 22 to the main control unit 21 to which the processing is requested. Thereafter, the initiator device 2 and the target device 3 follow the phases defined by the SCSI. Next, the write process will be described. Here, a description will be given of a process for writing the parameters of the shaded area shown in FIG. In the initiator device 2, the main control unit 2
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-mentioned read (S510). In this case, "3Bh" is set in the operation code, and otherwise, the same contents as those set in the case of the above read are set. As described above, the WRITE BU in which each value is set
Since the FFER command is passed to the command control unit 23, the command control unit 23 transmits the passed WRITE BUFFER command to the target device 3 according to the command phase (S520). Thereafter, 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 from the initiator device 2 input through the SCSI bus 1 (S540) and passes it to the main control unit 32. After that, the process proceeds to the data phase, receives the parameter value from the initiator device 2 input through the SCSI bus 1 (S550), and passes it to the main control unit 32. The main control unit 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 control unit 31 (S560). The searched parameter is changed (rewritten) to the value of the parameter received from the command control unit 31 (S570). Thereafter, the initiator device 2 and the target device 3 follow the phase defined by the SCSI. In the above-described embodiment, the parameter groups are stored in a storage format as shown in FIG. 2, that is, in a two-dimensional array. However, the present invention is not limited to this. good. That is, the group 0, the group 1,..., And the group 29 may be independent areas, and the desired parameter may be specified by specifying the group number and the offset value as described above. In other words, hierarchies into a group and a lower level of parameters included in the group. As described above, according to the present embodiment, the parameters are grouped in the memory 33 in the target device 3 and held so that addresses can be designated corresponding to the respective parameters. A READ BUFFER command / WRIT 32 includes address information (page number and offset value) of a desired parameter from the initiator device 2 input via the SCSI bus 1 and the command control unit 31.
Since the parameters stored in the memory 33 are accessed based on the E BUFFER command, the user can freely use the parameters defined when the MODE SENSE command / MODE SELECT command is used, as in the related art. The data (parameters) of the number that can be set by the READ BUFFER command / WRITE BUFFER command can be accessed without being limited by the appropriate number of data (that is, 30). Therefore, the parameter read / write access unit can be set to the parameter unit.
Data transfer time can be reduced. As described in detail above, according to the present invention, a parameter group is held in a storage means so as to be able to designate an address corresponding to each parameter, and an access means is provided with a predetermined interface. When a read buffer command or a write buffer command including address information of a desired parameter is received from the initiator device input through
Since the parameter corresponding to the address information is accessed to the storage means, the parameter can be accessed in parameter units. Further, even if the access is to one of a plurality of parameters and the access must be made in units of blocks having a predetermined number of parameters in the related art, the present invention is not limited to this. According to this, access to the corresponding parameter can be performed in parameter units, so that data can be transferred in parameter units as compared with the related art, and the data transfer time can be reduced. As described above, there is an advantage that a target device capable of improving the data transfer processing efficiency can be provided.

BRIEF DESCRIPTION OF THE 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 view 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 and write operation. [Description of Signs] 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.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G06F 13/42 310 G06F 3/06 301 WPI (DIALOG)

Claims (1)

(57) [Claim 1] In a target device which is connected to an initiator device via a predetermined interface and reads or writes a value of a parameter group grouped by the initiator device in a group unit, Storage means for storing group information for specifying a group to which a parameter belongs, and parameter information for specifying the position of the parameter in the group in association with the parameter; and from the initiator device input via the predetermined interface. When the buffer command including the group information and the parameter information corresponding to the desired parameter is received, an access for reading or writing the desired parameter stored in the storage means is performed based on the received group information and the parameter information. Target apparatus characterized by and means.