JPH063937B2 - Data transfer method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a data transfer system for transferring information between a plurality of devices via a common device.

(Prior Art) Regarding the data transfer method in the communication control device, the Institute of Electronics and Communication Engineers Technical Report IN82-53, and Nikkei Electronics 1984.10.8, P131-158.
Have been introduced. The outline of the data transfer method published in Nikkei Electronics is explained below.

FIG. 2 shows a block diagram of a communication control device, 1 is a control unit, 2 is a shared memory, 3 is a communication control unit, 4 is a communication line,
Reference numeral 5 is a memory bus, and 6 is a control line, which transfers data received from the communication line 4 from the communication control unit 3 to the control unit 1 and also transfers data from the control unit 1 to the communication control unit 3 to communicate with the communication line. 4 is to be sent. The control unit 1 generates data to be sent to the communication line 4, processes data received from the communication line 4, and controls the communication control unit 3.
The shared memory 2 serves as a data buffer for transmitting / receiving data,
And a storage device having the data buffer and a data transfer control table performed between the control unit 1 and the communication control unit 3. The contents of the shared memory 2 and the memory in the communication control unit 3 are as shown in FIG. Shared memory 2
Is composed of a command address table 7, a status word table 12, a reception system command word table 8, a transmission system command word table 9, a reception data buffer 10 and a transmission data buffer 11.

When transmitting data, the control unit 1 sets the data to be transmitted to the transmission data buffer 11 of the shared memory 2,
The identification code of the data transmission command, the start address of the transmission data buffer, the transmission data length, etc. are set in the transmission system command word table 9, and the start address of the transmission system command word table 9 is set in the command address table 7. Next, the control unit 1 confirms via the control line 6 that the communication control unit 3 is not in a busy state, and activates transmission to the communication control unit 3 via the control line 6. When the communication control unit 3 receives a transmission activation from the control unit 1, it first reads the start address of the transmission system command word table 9 set in the command address table 7 of the shared memory 2, and the transmission system command word table is read by this start address. The head address of the transmission data buffer 11 set to 9 and transmission control information such as the transmission data length are read.
Next, according to the read start address of the transmission data buffer 11 and the transmission control information, the transmission data buffer 11
The transmission data is read out and transmitted to the communication line 4.

Further, when receiving data, the control unit 1 causes the command address table 7 of the shared memory 2 to store the start address of the receiving command word table 8 and the status word table 12.
Of the data reception command, the start address of the reception data buffer 10, the reception data buffer, etc. are set in the reception system command word table 8 and the transmission control unit 3 is activated for reception. When the communication control unit 3 receives data from the communication line 4 in this state, it reads the start address of the reception system command word table 8 from the command address table 7 of the shared memory 2 and receives from the reception system command word table 8 according to this start address. The transfer control information such as the start address of the data buffer 10 and the received data buffer length is read, and the received data is sequentially transferred to the designated area of the received data buffer 10 according to this transfer control information. When the transfer is completed, the head address of the status word table 12 is read from the command address table 7 of the shared memory 2, and the head data of the received data amount, the head address of the reception system command word table 8, etc. The reception state of the shared memory 2 is set and the shared memory 2 is displayed on the control unit 1. When the control unit 1 receives the reading indication of the shared memory 2, it reads the reception state from the status word table 12, reads the start address of the reception data buffer with the command address table 7 and the reception command word table 8, and then from this start address. The received data is read from the received data buffer 10 by the amount of received data designated by the status word table 12.

(Problems to be Solved by the Invention) However, the apparatus having the above-mentioned configuration has a drawback in that the shared memory 2 requires separate data buffers for the receiving system and the transmitting system, resulting in memory division loss.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the drawback that the memory amount increases due to division loss as a result of providing the above-described reception data buffer and transmission data buffer separately, and to provide a communication control device with excellent economical efficiency. To do.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a display line and a request line between the first device (communication control unit) and the second device (control unit). , Common device (common memory)
Is provided with one or a plurality of buffer memories and switching means for changing the connection of the information transfer line between the buffer memories and the first and second devices, and the first device and the second device.
In transferring data between the devices, any empty buffer is selected according to the status information of the plurality of buffer memories notified to each other via the display line, the data is stored in the selected buffer, and then the request line is used. After the read request is displayed to the transfer destination and the connection of the information transfer line (bus) is switched by the switching means, the first device or the second device receiving the read request transfers the data from the buffer. The data was read out and transferred.

(Operation) First, when transferring data from the first device (communication control unit) to the second device (control unit), first, an arbitrary empty buffer is created by the empty information of the buffer memory notified via the display line. The buffer selected by the switching unit of the common device is connected to the first device by a bus to store the data to be transferred. Next, after connecting the buffer selected by the switching means and the second device to the bus, a data read request is issued from the first device to the second device through the request line. The second device, which has received the read request, reads the data from the buffer and completes the data transfer.

On the contrary, when transferring data from the second device to the first device, similarly, after selecting an arbitrary empty buffer and storing the shared data in the buffer, a request for reading the data is issued by the request line. By receiving the request, the first device reads the data from the buffer, so that the buffer can be shared for transmission and reception between the plurality of devices, and the data transfer is performed.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of the present invention, in which 4 is a communication line, 21 is a communication control unit, 22 is a control unit, 25 is a shared memory, 26 and 27 are display lines, 1a, 1b is a demand line, 2
8 and 29 are buses, 30 is a control line, and the shared memory 25
Is further composed of a control line 23, a selector 24, and a plurality of buffers Ba to Bz. The communication control unit 21 is connected to the opposite communication device via the communication line 4, and the display line 2
6, 27 and request lines 1a, 1b are connected to the control unit 22, and further, a bus 28 and a control line 30 are connected to the shared memory 25. The plurality of buffers Ba to Bz of the shared memory 25 are for temporarily storing the data transferred between the communication control unit 21 and the control unit 22, and the selector 24 is the buffer Ba to Bz and the bus 28 or the bus 2.
The connection is switched between 9 and is connected by the connection circuit 23. Further, the display lines 26 and 27 are provided by the communication control unit 21 and the control unit 22 by the buffers Ba to Bz.
Each time data is transferred to or from any of the buffers, the empty or in-use state of the buffer is mutually displayed. Based on the display, the communication control unit 21 and the control unit 22 each have all the buffers Ba ... It manages the empty state of Bz.

First, the data received from the communication line 4 is transferred to the communication control unit 21.
From the case of transfer from the control unit 22 to the control unit 22 in FIG.
This will be described with reference to FIGS. Here, the flowchart shown in FIG. 4 shows the operation in the communication control unit 21,
The figure shows the operation of the controller 22. The communication control unit 21 selects one empty buffer from the buffers Ba to Bz of the shared memory 25 based on the empty buffer information displayed on the display line 27 (FIG. 5, ...), and the control circuit 23 via the control line 30. Send control information to. Selector 2 in control circuit 23
4 is operated to connect the selected one buffer to the bus 28, and the data transfer enable display is displayed on the communication control unit 21 by the control line 30 (FIG. 4,). Then, the communication control unit 2
1 transfers data to the selected buffer via the bus 28 (FIG. 4). After the data transfer is completed, the control line 30
An instruction to switch the buffer from the bus 28 to the bus 29 is given via the command line, and the control unit 22 is read and displayed by the request line 1a to the control unit 22 (FIG. 4,). The control unit 22 reads the data from the aforementioned buffer via the bus 29 according to the read display information from the communication control unit 21 (FIG. 5,). Upon completion of reading the data, the communication control unit 2 is displayed by the display line 27.
The empty display of the buffer is performed at 1, and the transfer of the received data from the communication control unit 21 to the control unit 22 ends. As a result, the communication control unit 21 can update its own empty buffer information.

Next, a case where transmission data is transferred from the control unit 22 to the communication control unit 21 will be described. First, the communication control unit 2
The control unit 22 selects one empty buffer from the plurality of buffers Ba to Bz of the shared memory 25 according to the empty buffer information managed by the control unit 22 itself based on the information of the display line 26 from 1 (the fifth buffer). ,,). Then control 22 to bus 29
The data is transferred to the selected buffer via (FIG. 5), and after the transfer is completed, the communication controller 2 is requested via the request line 16.
A read request for the data stored in the buffer is issued to 1. When the communication control unit 21 receives a read request for buffer-stored data from the control unit 22 (see FIG. 5,
), Selector 24 to control circuit 23 via control line 30
Is used to instruct connection switching from the bus 29 to the bus 28, and data in the buffer is read out via the bus 28. When the data reading is completed, the communication control unit 2
Reference numeral 1 sends control information to the control circuit 23 through the control line 30 to instruct control switching from the bus 28 to the bus 29, and a display line 26 displays an empty display of the buffer to the control unit. The transfer of the transmission data from 22 to the communication control unit 21 is completed.

As described above, the buffer of the shared memory 25 can share the reception data and the transmission data without distinction.

FIG. 6 is a block diagram of another embodiment of the present invention. 221 to 22n are control units, 1a1 to 1an and 1b1 to 1b.
n indicates request lines connected between the communication control unit 21 and the control units 221 to 22n. (Other symbols are the same as those in FIG. 1.) In this embodiment, the data received from the communication circuit line 4 is transmitted via the shared memory 25 to the plurality of control units 221 to 22.
The data is transferred to the communication line 4 from the control units 221 to 22n via the shared memory 25 while being transferred to the communication line 4. The case of the present embodiment is the same as the case shown in FIG. 1 except that there is a plurality of control units. That is, the data received from the communication line 4 is transferred to any empty buffer of the buffers Ba to Bz as in the case described with reference to FIG. 1, and the arbitrary control units 221 to 22n using the request lines 1a1 to 1an. The read request is sent to the control units 221 to 22n, and each of the control units 221 to 22n reads data from the buffer.
The communication control unit is notified of the empty information of the buffer via 7. On the contrary, the data from the control units 221 to 22n are also transferred in the same manner as in the case described with reference to FIG. The buses 28 and 29 can transfer both data and addresses, and can select any empty buffer from each of the control units 221 to 22n.

Although only the data transfer within the communication control device has been described in the above embodiments, the present invention can be similarly implemented in a system in which information is generally transferred between a plurality of devices via a common device.

(Effects of the Invention) As described in detail above, according to the present invention, the communication control unit of the communication control device and the control unit are provided with the empty buffer display function and the buffer read request function, and the shared memory is provided with the buffer bus. Since the connection switching function is provided, the buffer can be shared by the reception data and the transmission data, and the expensive memory can be efficiently used. Further, it is possible to provide a plurality of control units (for example, even if a plurality of CPUs are provided, data communication between the communication control unit and CPUs can be performed).
The number of buffers in the shared memory can be freely increased or decreased according to the amount of transferred data. Therefore, by using the present invention, it is possible to economically construct a data communication system that transfers information between a plurality of devices via a common device.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a block diagram of a conventional communication control device, and FIG. 3 is an explanatory diagram showing contents of a memory in a conventional shared memory 2 and a communication control unit 3. FIG. 4 is a flowchart showing the operation of the communication control unit 21 in the embodiment of the present invention, FIG. 5 is a flowchart showing the operation of the control unit 22 in the embodiment of the present invention, and FIG. 6 is another embodiment of the present invention. It is a block diagram which shows an example. 4 ... Communication line, 21 ... Communication control unit, 22, 221-2n
... Control unit, 23 ... Control circuit, 24 ... Selector, 25 ... Shared memory, 26, 27 ... Display line, 1a, 1a1-1a
n, 1b, 1b1 to 1bn ... Request line, 28, 29 ... Bus, 30 ... Control line.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Toru Furuhashi 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (56) References JP-A-58-105344 (JP, A) JP-A-SHO 56-65553 (JP, A) Actually opened 58-107646 (JP, U)

Claims (1)

[Claims] 1. A data transfer system for transferring information from one first device to one or more second devices via a common device, wherein the common device has one or more buffer memories and the buffers. Memory and the first
Switching means for switching the connection of the information transfer line between the second devices is provided, and a display line for displaying the state of the buffer used between the first device and the second device and data reading are requested. The request line is provided, and the first line
When the data is transferred between the second device and the second device, any empty buffer is selected by the status information of the buffer memory notified via the display line to store the data, and the switching means switches the information transfer line After changing the connection, a read request is displayed to the transfer destination by the request line, and the device that receives the read request reads the data from the buffer, so that the buffer is shared between transmission and reception among multiple devices. A data transfer method characterized in that data transfer is performed by enabling.