JP2000222344A - Communication controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the efficiency of data communicating operation by determining the transfer size of reception DMA on the basis of a reception speed when the kind of communication is decided as reception and setting the determined reception DMA transfer size. SOLUTION: The kind of communication is decided according to whether or not DCS 3-2 is received; when the DCS 3-2 is received, DCS 3-2 indicating a reception speed determined according to a receivable communication speed of DIS 3-1 and a transmittable communication speed of a transmission device is received and reception speed data of the DCS 3-2 is stored in a RAM. On the basis of the reception speed data, a data table stored in a ROM is referred to and the reception DMA transfer side is set as reception DMA transfer buffer size in DMAC(dynamic direct memory access controller) through a data bus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a communication control device, a control method, and a computer-readable storage medium capable of performing data communication by DMA (Direct Memory Access) transfer.

[0002]

2. Description of the Related Art First, a conventional example of this type of communication control apparatus will be described with reference to FIGS. In addition,
Since the basic configuration of the communication control device is the same as that shown in FIG. 1 described in the embodiment described later, in the following description of the operation, each component and reference numeral shown in FIG.
1-1, ROM1-2, RAM1-3, BUS1-4,
DMAC (DMA controller) 1-5, MODEM
(Modulator / demodulator) 1-6 and NCU (network controller) 1-7 will be partially explained.

FIG. 7 is a flowchart showing a control operation in a conventional communication control device, and FIG. 8 is an explanatory diagram showing a data table of a communication speed and a transfer size used in the conventional communication control device.

First, step 7-1 in FIG. 7 is a step for determining a communication speed. When the communication speed is determined in transmission or reception of communication, this value is stored in the RAM 1-3.

Next, in step 7-2, the RAM 1-3 storing the communication speed is read out, and the DMA transfer size corresponding to the communication speed is determined with reference to the data table shown in FIG. -3.

In step 7-3, the DMA
The data in the RAM1-3 in which the transfer size is stored is read, and a transfer buffer size is set in the DMAC1-5.

[0007] Thereafter, in step 7-4, step 7
After the completion of the DMA transfer set in -3, it is determined whether or not to continue the DMA transfer. Here, if the DMA transfer is performed continuously, the process returns to step 7-3, and if the DMA transfer is not performed, the process ends.

In such a conventional operation, the DMA
The transfer size is determined by referring to the same data table for both transmission and reception, and the transfer size for transmission only and the transfer size for reception only cannot be fixed.

[0009]

As described above, the conventional D
In a communication control device that performs MA transfer, the DMA transfer size cannot be set optimally because the DMA transfer size is determined by referring to the same data table for both transmission and reception.
There is a drawback that a delay occurs in confirming the end of the transfer, and the efficiency of the data communication operation is low.

Therefore, according to the present invention, the DMA transfer size can be freely set by transmission and reception, and D
It is an object of the present invention to provide a communication control device capable of performing communication by optimally setting an MA transfer size.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a communication control apparatus having a DMAC capable of performing data communication using DMA transfer, a transmission / reception determining means for determining whether the type of communication is transmission or reception, and a reception speed. , A transfer size determining unit for determining a DMA transfer size from the reception speed, and a setting unit for setting the transfer size in the DMAC.

When the type of communication is determined to be reception by the transmission / reception determination means, the transfer size of the reception DMA is determined by the reception transfer size determination means based on the reception speed determined by the reception speed determination means. And setting the receiving DMA transfer size by the setting means. Further, when the type of communication is determined to be transmission by the transmission / reception determination means, the determination is not made by the reception speed determination means and the reception transfer size determination means, and the transmission DMA size is always fixed by the setting means. It is characterized by doing.

Further, the present invention provides a communication control apparatus having a DMAC capable of performing data communication using DMA transfer, a transmission / reception determining means for determining whether the type of communication is transmission or reception, and a transmission / reception determining means for determining a transmission speed. It is characterized by comprising a speed determining means, a transmission transfer size determining means for determining a DMA transfer size from a transmission speed, and a setting means for setting the transfer size in the DMAC.

When the type of communication is determined to be transmission by the transmission / reception determining means, the transfer size of the transmission DMA is determined by the transmission transfer size determining means based on the transmission speed determined by the transmission speed determining means. And setting the transmission DMA transfer size by the setting means. Further, when the type of communication is determined to be received by the transmission / reception determining means, the determination is not performed by the transmission speed determining means and the transmission transfer size determining means, and the receiving DMA size is always fixed by the setting means. It is characterized by doing.

With the above configuration, the DMA transfer size can be fixedly or variably set depending on whether transmission or reception is performed, and the DMA size can be variably set depending on the communication speed.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing a schematic configuration of a communication control device according to one embodiment of the present invention.

In FIG. 1, a CPU 1-1 includes a ROM 1
The operation of the entire apparatus is performed based on programs and data stored in the ROM-2, etc. The ROM 1-2 corresponds to, for example, a data table as shown in FIG. 2 or flowcharts as shown in FIGS. The program (FIG. 6) to be executed is stored (preset).

The RAM 1-3 functions as data exchanged with the DMAC (Direct Memory Access Controller) 1-5 and as a work area for various programs, and the BUS 1-4 is used as a data area between the constituent elements. For sending and receiving.

The DMAC 1-5 controls the DMA transfer between the MODEM (modulator / demodulator) 1-6 and the RAM 1-3.

The MODEM 1-6 modulates the data received from the DMAC 1-5 as appropriate according to the recommendations of the ITU-T, and transmits the data to an NCU (network control unit) 1-7.
The data received from 1-7 is demodulated and transferred to the DMAC 1-5 according to the recommendations of ITU-T.

The NCU 1-7 sends data from the MODEM 1-6 to the line, and sends data from the line to the MOD.
EM1-6 receives the call and controls outgoing and incoming calls.

FIG. 2A is an explanatory diagram showing a data table for determining the reception transfer size from the reception speed according to the present embodiment.

In this data table, the size of the received DMA transfer with respect to the receiving speed is tabulated,
2 is stored. This table data is shown in FIG.
Are used in step 4-5 of the reception flowchart shown in FIG.

FIG. 2B is an explanatory diagram showing a data table for determining the transmission transfer size from the transmission speed according to the present embodiment.

In this data table, the size of the transmission DMA transfer with respect to the transmission speed is tabulated, and the ROM1-
2 is stored. This table data is shown in FIG.
Is used in step 5-5 of the transmission flowchart shown in FIG.

FIG. 3 is a diagram of ITU-T Recommendation T.30. FIG. 3 is an explanatory diagram showing an example of a facsimile communication procedure specified in 30.

In FIG. 3, DIS 3-1 is a signal indicating the receiving capability of the receiving device and the like, and includes the receivable communication speed of the receiving device as data.

The DCS 3-2 receives the DIS 3-1 and determines a communication-capable capability from the receiving capability of the receiving device and the transmitting capability of the transmitting device. Yes, and the transmission speed at which transmission is possible is included as data.

The TCF 3-3 is a signal for transmitting dummy data for confirming that there is no communication error at the communication speed indicated by the DCS 3-2. Also, CFR
3-4 is a signal indicating that the dummy data transmitted by the TCF 3-3 has no abnormality.

PIX3-5 is image data to be transmitted, and Q3-6 is a signal indicating that transmission of image data 3-5 has been completed. The MCF 3-7 stores the image data 3
-5 is a signal indicating that the signal has been successfully received. Finally, DCN3-8 is a signal indicating that communication is to be disconnected.

FIG. 4 is a flowchart showing an operation example in which the DMA size is made variable during reception and the DMA size is fixed during transmission. It should be noted that the program corresponding to such a flowchart is ROMROM1 as described above.
-2.

In FIG. 4, step 4-1 is performed by DCS
This is a step of determining the type of communication based on whether or not the DCS 3-2 has been received. When the DCS 3-2 has been received, it is determined that the communication has been received, and the process proceeds to step 4-4.
Is not received, it is determined that this communication is transmission, and the process proceeds to step 4-2.

Step 4-2 is a step of setting the transmission DMA buffer size in the DMAC 1-5. That is, in the transmission operation, the transmission DMA buffer size always sets a constant value regardless of the communication speed.

Next, in step 4-3, when the transmission DMA transfer is completed, it is determined whether or not there is another transmission DMA transfer. If there is a next transmission DMA transfer, the process returns to step 4-2, and the next transmission DM
If there is no A transfer, the process ends.

In step 4-4, DIS 3-1
The DCS 3-2 indicating the reception speed determined from the receivable communication speed and the transmission speed that the transmission device can transmit is received, and the reception speed data of the DCS 3-2 is stored in the RAM 1-3.

Next, in step 4-5, step 4-
4 based on the reception speed data stored in the RAM 1-3.
With reference to the data table shown in FIG. 2A stored in the ROM 1-2, the receiving DMA transfer size is determined.
It is stored in the RAM 1-3.

Next, in step 4-6, step 4-
In step 5, the size of the receive DMA transfer stored in the RAM 1-3 is set as the receive transfer buffer size in the DMAC 1-5 through the BUS 1-4.

Next, in step 4-7, step 4-
In response to the completion of the transfer of the reception buffer set in step 6, it is determined whether or not there is the next reception DMA transfer. If there is the next reception DMA transfer, the process proceeds to the setting process in step 4-6. If there is no next reception DMA transfer, the process ends.

As described above, it is possible to control the DMA such that the DMA size is variable at the time of reception and the DMA size is fixed at the time of transmission.

FIG. 5 is a flowchart showing an operation example in which the DMA size is made variable during transmission and the DMA size is fixed during reception. It should be noted that the program corresponding to such a flowchart is stored in the ROM 1-
2 is stored.

In FIG. 5, step 5-1 is performed by DCS
This is a step of determining the type of communication based on whether or not the DCS 3-2 has been received. When the DCS 3-2 has been received, it is determined that the communication is a reception, and the process proceeds to step 5-2.
If the communication is not received, it is determined that this communication is transmission, and the process proceeds to step 5-4.

Step 5-2 is a step of setting the receive DMA buffer size in the DMAC 1-5. That is, in the reception operation, the reception DMA buffer size always sets a constant value regardless of the communication speed.

Next, in step 5-3, when the reception DMA transfer is completed, it is a step for determining whether or not there is another reception DMA transfer. Then, the next reception DMA
If there is a transfer, return to step 5-2,
If there is no next reception DMA transfer, the process ends.

In step 5-4, DIS 3-1
The transmission rate determined from the receivable communication speed of the transmission device and the transmission speed that the transmission device can transmit is sent by DCS3-2,
The transmission speed data of S3-2 is stored in the RAM1-3.

Next, in step 5-5, step 5-
4, based on the transmission speed data stored in the RAM 1-3,
The transmission DMA transfer size is determined with reference to the data table shown in FIG.
It is stored in the RAM 1-3.

Next, in step 5-6, step 5-
In step 5, the transmission DMA transfer size stored in the RAM 1-3 is set as the transmission transfer buffer size in the DMAC 1-5 through the BUS 1-4.

Next, in step 5-7, step 5-
In response to the completion of the transfer of the transmission buffer set in step 6, it is determined whether or not there is the next transmission DMA transfer. If there is the next transmission DMA transfer, the process proceeds to the setting process in step 5-6. If there is no next transmission DMA transfer, the process ends.

As described above, it is possible to control the DMA such that the DMA size is variable during transmission and the DMA size is fixed during reception.

Next, FIG. 6A is an explanatory diagram showing where each step of the flowchart explained in FIG. 4 is located in the ROM 1-2.

In FIG. 6A, reference numeral 6-1 denotes an area storing a step of determining whether communication is transmission or reception in step 4-1. Step 6-4 is performed in step 4-4.
Is an area in which the step of determining the reception speed is stored.

In step 6-5, the reception D is determined in step 4-5.
6-4 is an area in which a step of setting the transfer buffer size in the DMAC 1-5 in steps 4-5 and 4-6 is stored. .

On the other hand, FIG. 6B is an explanatory diagram showing in which part of the ROM 1-2 each step of the flowchart explained in FIG. 5 is located.

In FIG. 6B, reference numeral 6-5 denotes an area storing a step of determining whether communication is transmission or reception in step 5-1. Step 6-6 is performed in step 5-4.
Is an area in which the step of determining the transmission speed is stored.

6-6 is the transmission D in step 5-5.
6-8 is an area storing a step of setting the transfer buffer size in the DMAC 1-5 in steps 5-2 and 5-6. .

Although the above embodiment has been described with respect to an example in which the steps of the control program are stored in the ROM 1-2 in advance, the storage medium to be stored may be a floppy disk, CD-ROM, hard disk, memory card, or the like. ,
A magneto-optical disk or the like can be used.

Further, a floppy disk, a hard disk, a memory card, or the like can be used as a recording medium in which both the storage area and the RAM can be rewritten.

Further, the system may be such that a program stored in an external storage medium is appropriately loaded into the apparatus and processed.

In the above embodiment, the DMA transfer size is determined from the communication speed by referring to the data table. However, the DMA transfer size may be determined by calculation instead of referring to such a data table. .

In the above embodiment, a facsimile apparatus has been described as an example of a communication control apparatus. However, other data communication apparatuses may be used instead of the facsimile apparatus.

[0060]

As described above, according to the present invention,
Communication performed using DMA transfer depends on transmission or reception.
The DMA transfer size can be appropriately used so as to be fixedly set or variably set according to the communication speed. The transfer end can be properly and promptly confirmed with the optimum DMA transfer size, which is efficient. There is an effect that a communication control device can be provided.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram showing a data table for determining a reception transfer size from a reception speed and a data table for determining a transmission transfer size from a transmission speed according to the embodiment;

[Fig. 3] ITU-T Recommendation T. FIG. 3 is an explanatory diagram showing an example of a facsimile communication procedure specified in 30.

FIG. 4 is a flowchart illustrating an operation example in which the DMA size is made variable during reception and the DMA size is fixed during transmission in the embodiment.

FIG. 5 is a flowchart illustrating an operation example in which the DMA size is made variable during transmission and the DMA size is fixed during reception in the embodiment.

FIG. 6 is an explanatory diagram showing in which part of the ROM1-2 each step of the flowchart described with reference to FIGS. 4 and 5 is located;

FIG. 7 is a flowchart showing a control operation of a conventional example.

FIG. 8 is an explanatory diagram showing a data table of a communication speed and a transfer size used in the conventional example.

[Explanation of symbols]

 1-1 CPU, 1-2 ROM, 1-3 RAM, 1-4 BUS, 1-5 DMAC, 1-6 MODEM, 1-7 NCU.

Claims (18)

[Claims] 1. A communication control apparatus having a DMAC capable of performing data communication using DMA transfer, comprising: a transmission / reception determining means for determining whether the type of communication is transmission or reception; and a reception speed determining means for determining a reception speed. A communication control device, comprising: a reception transfer size determination unit that determines a DMA transfer size from a reception speed; and a setting unit that sets the transfer size in the DMAC. 2. The communication control device according to claim 1, wherein, when the type of communication is determined to be reception by the transmission / reception determination unit, the reception transfer is performed based on the reception speed determined by the reception speed determination unit. DM received by size determination means
A communication control device, wherein a transfer size of A is determined, and the setting means sets the receive DMA transfer size. 3. The communication control device according to claim 1, wherein when the type of communication is determined to be transmission by the transmission / reception determination unit, the determination is not performed by the reception speed determination unit and the reception transfer size determination unit, Transmission D by the setting means
A communication control device wherein the MA size is always fixed. 4. A communication control device having a DMAC capable of performing data communication using DMA transfer, comprising: a transmission / reception determining means for determining whether the type of communication is transmission or reception; a transmission speed determining means for determining a transmission speed. A communication control device, comprising: a transmission transfer size determination unit that determines a DMA transfer size from a transmission speed; and a setting unit that sets the transfer size in the DMAC. 5. The communication control device according to claim 4, wherein when the type of communication is determined to be transmission by the transmission / reception determining unit, the transmission transfer is performed based on the transmission speed determined by the transmission speed determining unit. Send DM by size determination means
A communication control apparatus, wherein a transfer size of A is determined, and the setting means sets the transmission DMA transfer size. 6. The communication control device according to claim 4, wherein when the type of communication is determined to be reception by the transmission / reception determination unit, the transmission speed determination unit and the transmission transfer size determination unit do not perform determination. Received by the setting means
A communication control device wherein the MA size is always fixed. 7. A method for controlling a communication control device having a DMAC capable of performing data communication using DMA transfer, comprising: a transmission / reception determining step of determining whether the type of communication is transmission or reception; and a reception speed determining a reception speed. A control method for a communication control device, comprising: a determining step; a receiving transfer size determining step of determining a DMA transfer size from a receiving speed; and a setting step of setting the transfer size in the DMAC. 8. The control method of the communication control device according to claim 7, wherein when the type of communication is determined to be reception in the transmission / reception determination step, based on the reception speed determined in the reception speed determination step, The receiving DM is determined by the receiving transfer size determining step.
A method for controlling a communication control device, comprising: determining a transfer size of A; and setting the receive DMA transfer size in the setting step. 9. The control method of the communication control device according to claim 7, wherein when the type of communication is determined to be transmission in the transmission / reception determination step, the determination by the reception speed determination step and the reception transfer size determination step is performed. Not performed, transmission D by the setting process
A method for controlling a communication control device, characterized in that an MA size is always fixed. 10. A method for controlling a communication control device having a DMAC capable of performing data communication using DMA transfer, comprising: a transmission / reception determining step of determining whether the type of communication is transmission or reception; and a transmission speed determining a transmission speed. A control method for a communication control device, comprising: a determination step; a transmission transfer size determination step of determining a DMA transfer size from a transmission speed; and a setting step of setting the transfer size in the DMAC. 11. The control method for a communication control device according to claim 10, wherein when the type of communication is determined to be transmission in the transmission / reception determination step, based on the transmission rate determined in the transmission rate determination step, The transmission DM is determined by the transmission transfer size determination step.
A method for controlling a communication control apparatus, comprising: determining a transfer size of A; and setting the transmission DMA transfer size in the setting step. 12. The control method of the communication control device according to claim 10, wherein when the type of communication is determined to be reception in the transmission / reception determination step, the determination by the transmission speed determination step and the transmission transfer size determination step is performed. Not performed, receiving D
A method for controlling a communication control device, characterized in that an MA size is always fixed. 13. A computer-readable storage medium storing a control program for a communication control device having a DMAC capable of performing data communication using DMA transfer, wherein the control program determines whether the type of communication is transmission or reception. A transmission / reception determining step of determining a receiving rate; a receiving rate determining step of determining a receiving rate; a receiving transfer size determining step of determining a DMA transfer size from the receiving rate; and a setting step of setting the transfer size in the DMAC. A storage medium characterized by the above-mentioned. 14. The storage medium according to claim 13, wherein the control program, based on the reception speed determined in the reception speed determination step, when the type of communication is determined to be reception in the transmission / reception determination step. A storage medium that determines a transfer size of a reception DMA in the reception transfer size determination step and sets the reception DMA transfer size in the setting step. 15. The storage medium according to claim 13, wherein when the type of communication is determined to be transmission in the transmission / reception determination step, the determination is not performed by the reception speed determination step and the reception transfer size determination step, Transmission D by setting process
A method for controlling a communication control device, characterized in that an MA size is always fixed. 16. A computer-readable storage medium storing a control program for a communication control device having a DMAC capable of performing data communication using DMA transfer, wherein the control program determines whether the type of communication is transmission or reception. A transmission / reception determining step of determining the transmission rate; a transmission rate determining step of determining a transmission rate; a transmission transfer size determining step of determining a DMA transfer size from the transmission rate; and a setting step of setting the transfer size in the DMAC. A storage medium characterized by the above-mentioned. 17. The storage medium according to claim 16, wherein when the type of communication is determined to be transmission in the transmission / reception determination step, the transmission transfer size is determined based on the transmission rate determined in the transmission rate determination step. DM sent by the decision process
A storage medium for determining the transfer size of A and setting the transmission DMA transfer size in the setting step. 18. The storage medium according to claim 16, wherein when the type of communication is determined to be reception in the transmission / reception determination step, the determination is not performed by the transmission speed determination step and the transmission transfer size determination step. Receive D by setting process
A storage medium characterized in that the MA size is always fixed.