JPS5997254A - Reception data transfer method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION 0) Technical Field of the Invention The present invention relates to the length of received data in a communication control device and the transfer method of that data, and in particular, the present invention relates to the length of received data in a communication control device and the transfer method of the data, and in particular, to A communication control method that does not have a delimiter to indicate the received data buffer and the host cannot determine the effective data length just by checking the received data buffer .

(b) Prior art and problems Conventionally, as a method for notifying the length of data received from a line as data from a communication control device to a host data processing device,
Broadly divided: ■ Storing the data length at the beginning of the buffer where the received data is stored or a specific area ■ Storing the data length in the area indicated by the READ command next to the area where the received data is stored - There are two methods, but in the former, the data length, which is known only after the reception processing of all received data of each block is completed, must be stored at the beginning of the data or in a specific area, and communication This requires an operation such as returning the transfer address to the start address or a specific address indicated by the command in the control device, which has the disadvantage that the processing for this becomes complicated. On the other hand, the latter method has the disadvantage that two READ commands are required to receive one data, which places a burden on the network controller and channel.

e9 OBJECTS OF THE INVENTION The present invention aims to solve the above-mentioned drawbacks of the conventional system, reduce infraction between a host data processing device and a communication control device, and simplify the processing of the communication control device.

B) Structure of the Invention In order to achieve the above object, the present invention provides a communication control bag which operates based on commands from a host data processing device, and which transmits information corresponding to the data length of a data block received from a line. A reception block data length holding means is provided for holding each received data block, and each time a data block is received until a data block including transmission delimiter information is detected, the reception block data length holding means stores the received data length. After storing the corresponding information and receiving the data block including the transmission delimiter υ information, the host data processes the information corresponding to the data length of a series of data blocks including the data length l of the data block. It is characterized in that it is configured to notify the device.

Embodiment of the Invention Fig. 1 is a block diagram of a data communication system according to an embodiment of the present invention. , 5 is a terminal.

FIG. 2 is a diagram illustrating an example of a series of received data blocks received from reminiscence, where block≠3 is the last transmitted block.

FIG. 3 is a diagram showing an example of a command group prepared by the host data processing device.

FIG. 4 is a diagram showing an example of a map of data stored in a buffer of the host data processing device as a result of performing reception processing on the received data shown in FIG. 2 using the command group shown in FIG. 3;

FIG. 5 is a block diagram of the communication control device 2 shown in FIG.
2 is an interface control unit, 13 is a command processing unit, 1
4 is a data transfer control unit, and 15 is a reception block data length holding buffer.

FIG. 6 is a diagram showing the operational flow of the embodiment.

The operation of the embodiment will be explained below.

Upon receiving the command≠1 from the host data processing device 1, the command processing section 13 of the communication control device 2 activates the data transfer control section 14 to execute data reception processing. The data transfer control unit 14 stores the received data block number 1 from the line in a buffer within the host data processing device 1.
Here, the data length of the received data block +1 is stored in the block≠1 corresponding area of the received block data length holding buffer 15.

When the processing of received data block +1 is completed, the command
The command processing unit 13 activates the data transfer control unit 14 in the same manner as described above to execute data reception processing.

The data transfer control unit 14 receives the received data block ≠ 2 from the line based on the command 2, stores the received data block 2 in a buffer in the host data processing device 1, and stores the received data block 2 in a buffer in the host data processing device 1. Receive the data length of block ÷ 2 Block data length holding buffer 1
Store it in the Blocker 2 corresponding territory of 5.

When the processing of received data blocker 2 is completed, the command ÷ 3
is received, and reception processing of received data block +3 is performed in the same manner as above. Here, the storage operation in the buffer in the host data processing device 1 and the data length of the received data block are stored in the received block data length holding area fi1.
The operation of storing the corresponding area mound 5 is the same as the above-mentioned block-#1 and block-+p transmission, but block number 3 is a block that indicates the end of a series of data block transmissions and includes transmission delimiter information. Therefore, the data transfer control unit 14 detects the transmission delimiter information and sets it in a register or memory area (not shown) as a "transmission" reception memo J.

It is to be noted that whether or not the series of purges has ended is determined, for example, by determining the P/F bit in the control field (C field).

After that, in the processing of the received command ÷ 4, the above "transmission delimiter reception memo" has been deleted, so
The data transfer control unit 14 transfers the data lengths of the received plotters 41 to 3 held in the received block data length holding buffer 15 to the host data processing device 11. Accordingly, the buffer area on the memory of the host data processing device 1 is set as shown in FIG.

Finally, the data transfer control unit 14 performs the above-mentioned [transmission delimiter reception (
If the "if memo" is reset, the operation corresponding to the drawing command ≠ 41 is completed.

(F) Effects of the Invention According to the present invention, execution of a normal READ command (regarding
Since address subtraction processing is not necessary, it can be performed even with devices connected to channels such as channels that can only transfer data in ascending order of addresses, and the READ command for transferring data and data length can be performed. The data and data length can be notified to the host with almost no increase (the number of transmission blocks + 1 is enough). In addition, this reduces the number of interactions between the communication food preparation device and the host, making it possible to avoid load concentration and constructing an efficient system.

It is obvious that a similar effect can be obtained if it corresponds to lζ.

Furthermore, when transferring the data length, it is also possible to transfer additional information other than the data length.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a data communication system according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of a receiving cheetah block, FIG. 3 is a diagram showing an example of a command group, and FIG. 4 is a diagram showing a host data processing device. In FIG. 5, 2 is a communication control device, 13 is a command processing section, 14 is a data transfer control section, and 15 is a reception block data length holding buffer. child 4 u 5th m yr figure

Claims (1)

[Claims] In a communication control device that operates based on instructions from a host data processing device, the data length of a data block received from a line (receive block data length holding means for holding the corresponding information for each received data block) is provided. , each time a data block is received until a data block including transmission delimiter information is detected, the received block data length holding means stores information corresponding to the received data length, and stores the data block including the transmission delimiter information. A received data transfer method characterized by being configured to notify a host data processing device of information corresponding to the data length of a series of data blocks, including information corresponding to the data length of the data block. .