JP2000076181A - Data transfer method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transfer a large amount of input data at a high speed by transferring the data directly from a transmission-side data transfer means to a transfer- destination recording medium through a data transfer line which is already connected. SOLUTION: The transmission-side data transfer means 5 is equipped with a data file converting means 1 and a SCSI control part 2. The SCSI control part 2 connects to the transfer destination by occupying the SCSI bus to the transfer destination in response to a command 4 from the data file converting means 1 and transfers a generated command 4 and inputted data to the SCSI control part 2 at the transfer destination. The inputted data is stored directly on the recording medium at the transfer destination under the control of the SCSI control part 2 at the transfer destination. Consequently, a large amount of data can be transferred at a high speed without using any buffer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transfer method, and more particularly to a data transfer method for transferring a large amount of data at a high speed.

[0002]

2. Description of the Related Art Conventionally, various proposals have been made for a method of transferring a large amount of data at a high speed. Through all of these proposals, a buffer memory is provided in a transmission side data transfer means, and data to be transmitted is stored. After being temporarily written into the buffer memory by the transmission-side data transfer means, the data is read from the buffer memory and transferred to the transfer destination. A typical example of such a conventional method is disclosed in Japanese Patent Application Laid-Open No. 4-124.
The invention disclosed in Japanese Patent No. 721 (hereinafter, referred to as prior art) will be described.

As shown in FIG. 4, a transmitting apparatus 40 of the prior art includes a data input unit 41, a buffer 42, a file output unit 43, and a SCSI (Small Computer System Interface).
ace) The control unit 44 is provided. Since the SCSI controller 44 is well known as a controller used for this type of data transfer, a general description is omitted. SCSI is generally provided as an interface at the transfer destination, and a data transmission path from the SCSI control unit 44 on the transmission side to the SCSI at the transfer destination is referred to as a SCSI bus, and is managed by the SCSI control unit 44. The data to be transferred is the data input means 4 of FIG.
1 is written to the buffer 42. Buffer 42
When the amount of data written to the storage unit reaches a preset data amount unit (block), the data block is transferred as a file to the transfer destination storage medium via the file output unit 43 and the SCSI control unit 44.

FIG. 5 is a flowchart showing the operation of the transmitting apparatus 40 shown in FIG. At the time of system initialization in step 500 of FIG. 5, the count value of a data counter (not shown) is reset to 0, and waits for data input. The data input is written into the buffer 42 by the data input means 41,
Each time a predetermined amount of data is written, the data count value is incremented by one (step 504). Until the data count value reaches the predetermined value (one block) (step 505: NO), the data input buffer 42
Writing to the buffer 42 continues, but when the data written to the buffer 42 reaches one block (step 505: Y
ES), the writing to the buffer 44 is temporarily stopped, and the process proceeds to step 506 to start the data transfer by the file output means 43.

At the start of data transfer, the file output means 43 sets a write command to the SCSI control unit 44 (step 506), resets the count value of the data count (step 507), and
3 reads the data from the buffer 42 and transfers the data to the data transfer destination via the SCSI bus via the SCSI control unit 44. Each time a predetermined amount of data is read from the buffer 42, the value of the data count is incremented by one (step 509). Until the value of the data count reaches the predetermined value (one block) (step 51).
0: NO) Reading from the buffer 42 is continued, but when the data read from the buffer 42 reaches one block (YES in step 510), the reading from the buffer 42 is temporarily stopped, and the process proceeds to step 511 to transfer. Check if the data transfer is complete,
If not completed, the process returns to step 500, and the writing of input data to the buffer 42 is restarted. However, the input data is checked in step 502 and the EOF (End Of
File), that is, if the data indicates the end of the file, the flow proceeds to step 506, and the transfer of data from the buffer 42 is started.

[0006]

SUMMARY OF THE INVENTION The first of the prior art methods
The problem is that a large buffer is required. That is, as shown in FIG.
In step 506, data is written to the buffer 42.
In steps 510 to 510, a cycle of reading data from the buffer 42 is repeated to transfer a desired amount of data. Therefore, if the capacity of the buffer 42 is small, the number of repetition cycles increases, and data transfer is interrupted during writing to the buffer 42. However, there is a problem that the transfer data is interrupted each time. If possible, it is desirable to provide a buffer having a capacity larger than the amount of data to be transferred at one time, but this requires a buffer having a large capacity.

A second problem is that processing time other than data transfer becomes long. This is because writing and reading processing to and from the buffer 42 for temporarily storing data is required for each data. The third problem is SCSI
The point is that the bus is released before the data transfer is completed.
That is, the occupation of the SCSI bus is permitted by the arbitration of the SCSI control unit 44, but the occupation is permitted during steps 506 to 510 in FIG. 5 and is released during steps 500 to 505 in FIG. I have to do it. When the same data is transferred to a plurality of connection destinations in parallel, the S
After releasing the CSI bus, the SC for the next transfer destination
Since the occupation of the SI bus must be requested, the SCS
It takes time from the request for occupation of the I bus to the permission for occupation.

Therefore, various proposals have been made for the purpose of solving the problems in the above-mentioned prior art documents. For example, “SCSI” disclosed in JP-A-6-314251 is disclosed.
In the invention entitled "Data transfer device", the first S
A CSI interface and a second SCSI interface for output are provided so that the occupation of the SCSI bus on the output side is not affected by the status of the SCSI bus on the input side. Further, a buffer interposed between the first SCSI interface and the second SCSI interface has a write port and a read port so that reading can be performed simultaneously during writing. However, no proposal has been made to omit a buffer for temporarily storing data to be transferred, and there is still a problem in this point.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a data transfer method capable of transferring a large amount of data at high speed without using a buffer.

[0010]

According to the present invention, prior to the start of data transfer, a write command stipulated for SCSI is set, so that the SCSI controller of the data transfer means on the transmission side is set. A data transmission path from occupying the SCSI bus to the SCSI controller at the transfer destination, reaching the SCSI controller at the transfer destination via the occupied SCSI bus, and reaching the recording medium controlled by the SCSI controller at the transfer destination The connection is completed, and the output data is transmitted through the data transmission path to which the connection has been completed, so that the data transfer means on the transmission side does not need a buffer.

That is, according to the method of the present invention, prior to the start of data transfer, a write command is set from the data file conversion means in the data transfer means on the transmission side to the SCSI control unit in the data transfer means on the transmission side. A write command setting request step for requesting a write command, setting a write command in the SCSI controller in response to the write command setting request, occupying the SCSI bus with the transfer destination, and writing the write command via the occupied SCSI bus. Destination SCS
Sent to the I control unit, and the SCSI in the data transfer means on the transmission side
A connection path completion step for completing the connection of the data transfer path to the storage medium under the control of the SCSI control section via the SCSI bus occupied by the control section and the SCSI control section of the transfer destination; A data count step of outputting data to the data transfer path connected in the connection path completion step and counting a unit of data output data;
When the data count value counted in this data count step reaches the set value set in the write command,
A write command resetting step of temporarily terminating the write command, requesting a new write command setting, and continuing to output data to the data transfer path while maintaining the data transfer path connected in the connection completion step; If the EOF data indicating the end of the file is received from the data input before the data count value counted in the data count step reaches the set value set in the write command, after outputting the EOF data, the data count is performed. A SCSI bus releasing step of outputting meaningless data until the value reaches the value set by the write command, and releasing the SCSI bus when the data count value reaches the value set by the write command. I do.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. A data transfer unit 5 on the transmission side includes a data file conversion unit 1 and a SCSI control unit 2, and the data file conversion unit 1 counts input data 3. To create a SCSI command 4 and SC data together with the input data 3.
An SI command 4 is output to the SCSI control unit 2. The transfer destination (not shown) of the data transfer system is the SC of the transmitting apparatus.
A SCSI controller similar to the SI controller 2 is provided, and a recording medium capable of storing input data under the control of the controller is provided.

The SCSI controller 2 of the data transfer means 5 on the transmission side occupies the SCSI bus between the data transfer means 1 and the transfer destination in response to the command 4 from the data / file conversion means 1, and connects to the transfer destination. The created command and the input data are transferred to the destination SCSI control unit, and the input data is stored in the destination storage medium under the control of the destination SCSI control unit. The operation of the data / file conversion means 1 and the operation of the SCSI control unit 2 are operated under program control of a processor (not shown).

FIG. 2 is a flowchart showing the operation of the data transfer means 5 on the transmitting side in FIG. Hereinafter, FIGS. 1 and 2
The operation of the data transfer means 5 on the transmission side will be described with reference to FIG. In the initialization step of step 100 in FIG. 2, the data count, which is the count value of a data counter (not shown), is reset to 0, and waits for input 3 of data to be transferred. At the head of the data to be transferred, a file open (file open) command is included, so that the input of this command is waited for (step 101). When a file open command is received, the data / file conversion means 1
Sets a write command in the SCSI controller 2. The format of the write command is SCSI write command (see reference numeral 35 in FIG. 3).
Is used. The write command is composed of 6 words of 8 bits as shown in FIG. In this case, the word of "transfer data length" on the fifth line is "00000" which means the maximum value.
000 ". With this setting, the SCSI control unit 2 occupies the SCSI bus with the transfer destination, and
Connects to SI control unit and transfers write command.

A write command is set in the SCSI control unit 2 on the transmission side, and the transfer destination SC is transmitted via the SCSI bus.
When the setting is also made in the SI control unit, the data file conversion means 1 on the transmission side waits for data input (step 103).
If there is data input, unless this is EOF (End Of File), which means the end of the file (step 104:
NO), the data is output as it is to the recording medium via the transfer destination SCSI controller (step 105), and the data count is incremented for each output of one data (step 106). Until the data count value reaches the set value (step 107: NO), steps 103 to 1
Repeat step 07. When the data count reaches the set value (step 107: YES), the data count is reset to 0 (step 108), the process returns to step 102, and the write command is set again, and steps 103 to 1 are performed.
Repeat step 07.

When the recording medium controlled by the SCSI controller at the transfer destination is a hard disk having a capacity of 2 Gbytes, the data of one block is 512 bytes, and the fifth line of the write command (35 in FIG. 3) “transfer data If all bits of “Length” are set to logical “0”, this means 256 blocks, so that data of 512 Byte × 256 ≒ 128 KByte has been transferred by the time step 107 becomes YES. If there is data to be left, the write command is set again in step 102 and the
The data transfer is repeated while occupying the SI bus. If the data to be transferred is EOF during the data transfer (step 104: YES), the process proceeds to step 109, in which meaningless data is transferred following the EOF data, and when the data count reaches the set value (step 11).
1: YES), end the data transfer, and release the SCSI bus.

FIG. 3 is a schematic diagram showing each phase of the SCSI bus in the operation steps shown in FIG.
The input to the SI bus is input from the data transfer means 5 on the transmission side. In the initial state, the SCSI bus is in the bus free state 30, and the first data input 3 contains a file open command (step 101 in FIG. 2: Y).
ES), the data file converter 1 sets a write command to the SCSI controller 2 (step 10).
2). A write command conforming to the SCSI specification is made up of 6 words of 1 word and 8 bits as indicated by reference numeral 35 in FIG.

The SCSI controller 2 sets a write command, occupies the SCSI bus reaching the transfer destination, and
First, a write command is transmitted through the CSI bus (phase 31). Write command is transfer destination SC
It is set in the SI control unit (not shown). Thereafter, the data transfer means 5 on the transmission side waits for data input while occupying the SCSI bus (step 103 in FIG. 2, phase 32 in FIG. 3), and executes data output if there is data input (step 105 in FIG. 2). If the data input 3 is a file close command (EOF) during the data output, the process proceeds to step 109 in FIG. 2 to transfer the meaningless data (indicated by NULL in FIG. 3). Has reached the set value (step 111: YES), terminates the data transfer and releases the SCSI bus (phase 3)
4).

As described above, the set value of the data count is set in the "transfer data length" word in the fifth row of the write command (reference numeral 35 in FIG. 3). Is set as the set value of 256 blocks. Even if the data count exceeds the set value (Step 1
07: YES), if the EOF does not occur, the write command is once terminated, and then the write command is set again (step 102). In this case, the set value is 25 for convenience.
Make 5

Although the present invention has been described with reference to the preferred embodiment, the present invention has various embodiments other than the above-described embodiment. For example, in the embodiment shown in FIG. 2, the write command is set in response to the input of the file open command (steps 101 and 102).
A write command setting command may be inserted in a program for controlling the data / file converter 1. During execution of steps 103, 104, 105 and 106 in FIG. 2, data to be input from the data input 3 and to be transmitted to the SCSI bus via the SCSI control unit 2 program-controls the data / file conversion means 1. It can be stored in a register in a microprocessor (not shown).

FIG. 6 is a block diagram showing another embodiment of the present invention, which is configured by adding a data input unit 6 to the data transfer means 5 on the transmitting side shown in FIG. In the apparatus shown in FIG. 1, it is assumed that data is input from a data source such as a host computer. However, by adding the data input unit 6, restrictions on the data source can be removed. The data input unit 6 has, for example, a protocol for transmitting and receiving wireless data and wired data, thereby enabling input by program control.

Although a hard disk has been described above as an example of a storage medium controlled by the SCSI controller at the transfer destination and capable of storing files, it goes without saying that any storage medium may be used.

The SCSI of the transmission-side data transfer means 5
The control unit 2 is used to select the SCSI control unit of the transfer destination.
8 bits of an SCSI code connected in parallel to the same SCSI bus
An arbitrary SCSI controller can be selected from the controllers, and data can be transferred to a recording medium under the control of the selected SCSI controller.

[0024]

As described above, according to the present invention, it is possible to omit the buffer memory in the data transfer means on the transmitting side, and to omit this buffer and to save the data on the data transfer path which has been connected in advance. , The data can be directly transferred from the data transfer means on the transmission side to the recording medium of the transfer destination, so that a large amount of input data can be transferred at high speed. Further, since the SCSI bus is occupied and the connected data transfer path is maintained until the transfer of all data is completed, a large amount of data can be transferred at high speed. There is.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the apparatus of FIG.

FIG. 3 is a schematic diagram showing each phase of a SCSI bus accompanying the operation shown in FIG. 2;

FIG. 4 is a block diagram showing a conventional method.

FIG. 5 is a flowchart showing the operation of the apparatus of FIG.

FIG. 6 is a block diagram showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Data file conversion means 2 SCSI control part 3 Data input 4 SCSI setting (command, data) 5 Data transfer means on transmission side 6 Data input part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuichi Iwashima 3-16-8 Shin-Yokohama, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture F-term in Nippon Electric Mobile Communication Co., Ltd. 5B061 AA04 BB02 FF01 FF04 GG01 RR05

Claims (9)

[Claims] 1. Prior to the start of data transfer, a data file conversion means in a data transfer means on a transmission side sends a SCSI (Small Computer) in a data transfer means on the transmission side.
Write command (write) to the system interface control unit
command) for requesting the setting of the write command.
Set a write command in the control unit, and
Occupies the SCSI bus, sends the write command to the SCSI controller of the transfer destination via the occupied SCSI bus, and sends the write command to the SCSI controller in the data transfer means on the transmission side. A connection path completion step for completing the connection of the data transfer path to the storage medium under the control of the SCSI control section via the SCSI control section, and the data completed in the connection path completion step for each unit of data input. A data counting step of outputting data to the transfer path and counting a unit of data that has been data output, and when the data count value counted in the data counting step reaches a set value set in the write command, the write command is Once completed, a new write command setting request was made, and connection was completed in the connection path completion step. A write command resetting step of continuing data output to the data transfer path while maintaining the data transfer path, and setting the data within the data count value counted in the data count step not reaching the set value set in the write command. When EOF data indicating the end of the file is received from the input, after outputting this EOF data, meaningless data is output until the data count value reaches the value set by the write command. A SCSI bus releasing step of releasing the SCSI bus when a data count value reaches a value set by the write command. 2. The data transfer method according to claim 1, wherein said write command setting request step is started by inputting data instructing to open a file from said data input. Method. 3. The data transfer method according to claim 1, wherein said write command setting request step is incorporated in a control program for controlling an operation of said data / file conversion means. 4. The data transfer method according to claim 1, wherein the data count set value set by the write command is a settable maximum numerical value. 5. The data transfer method according to claim 4, wherein a maximum value is set to a fixed value for a transfer data length of the write command. 6. The data transfer method according to claim 1, wherein the recording medium under the control of the SCSI controller at the transfer destination is a hard disk, and the data of one unit is 51.
A data transfer method characterized by being 2 bytes. 7. The data transfer method according to claim 1, wherein the SCSI control unit in the data transfer unit on the transmission side is any one of a plurality of SCSI control units of a transfer destination connected in parallel to the same SCSI bus. A data transfer method, wherein one of the above is selected by its ID (identification code). 8. The data transfer method according to claim 1, wherein the data to be transferred as one unit of data output from the data input to the data transfer path connected in the connection completion step is the transmission side data transfer. In the data transfer method, the data is temporarily stored in a register of a processor that controls the data / file conversion means. 9. The data transfer method according to claim 1, wherein the data transfer means on the transmitting side has a data input unit provided with a protocol for transmitting and receiving wireless data and a protocol for transmitting and receiving wired data, and directly transfers these data. A data transfer method characterized in that data transfer is possible.