JPS59151223A - Block division dma transfer system between computer and terminal equipment - Google Patents

Abstract

PURPOSE:To reduce the capacity of a used memory, by dividing information data to plural blocks to transfer data. CONSTITUTION:In case of direct memory access DMA transfer from an electronic computer 1 to a terminal equipment 2, the computer 1 sets divided information data (1) 6 to a block division memory 4 and requests the transfer to a DMA control part 3. Then, the equipment 2 is started after a DMA control part 7 sets data (1) 6 to a receiving memory buffer 5, and the equipment executes the processing of data (1) 6 in the buffer 5 simultaneously with outputting of a busy signal to the computer 1. After the processing, the equipment 2 releases the busy signal to make it possible to receive next divided information data (2) 6. Next, the computer 1 requests the transfer to the control part 3 after setting data (2) 6 to the memory 4. This sequency is repeated to transfer all of required data 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combiner system, and more particularly to a block division DMA transfer method between a computer and a terminal device, which is applied to connection with a plurality of terminal devices.

Conventionally, when combining a converter and a terminal device using the DMA transfer method, all necessary information was created on the combiner side,
A common method was to transfer data all at once to a terminal device. However, with this method, if there is a large amount of necessary information created on the computer side, the terminal device side also needs a memory buffer that can receive all of this information, resulting in an increase in memory capacity.

Furthermore, if there are a large number of terminal devices on the combiner side, and information transferability is required to the terminal devices at the same time, an information storage memory buffer will be required for each terminal device, resulting in an increase in memory capacity. In particular, terminal devices such as graphic display devices that require a large amount of information to be transferred have the disadvantage that a large amount of memory is required for the computer and the terminal equipment, leading to an increase in costs.

The purpose of the present invention is to overcome the above drawbacks by changing the DMA transfer method between a computer and a terminal device to a block division method rather than a batch transfer method, thereby making it possible to reduce the amount of memory required for terminal equipment. The purpose is to provide the following:

In the present invention, information data for which DMA transfer is performed from the computer side is divided into a plurality of blocks, and a block end code is added to the final data of each block. Transfer to the device; Also, the terminal device side must also prepare a reception memory buffer for this one block. (・By taking the above method, it is possible to reduce the amount of memory used for both versions. .

In the present invention, if the information data divided into blocks is sequentially transferred from the computer side to the terminal device, the blocks that have been transferred can be used for other purposes and can be used as the next block of information data. That is, a large amount of information data can be transferred using a small amount of memory cyclically.

Next, the present invention will be explained in detail with reference to the drawings of an embodiment of the present invention. Referring to the drawings, the embodiment of the present invention will be explained in detail with reference to the drawings of an embodiment of the present invention. DMA transfer of terminal device 5DMA-control P,!! 3, 7
and information data 6, and a receiving memory buffer 5 on the terminal device side. When performing DMA transfer from the computer 1 to the terminal device 2, the combination 1 sets the division information data (1) 6 in the block division memory 4 and requests the DMA control unit 3 to transfer the data. After setting the divided information data (1) 6 to the receiving memory buffer 5, the terminal device 2 DMA control unit 7 is activated, and simultaneously outputs the heavy signal to the computer 1 and processes the divided information data (1) 6 in the receiving memory buffer 5. conduct. After the processing is completed, the terminal device 2 cancels the busy signal and sends the next divided information data (2
)6 can be received.

When the busy signal is released, the computer 1 makes a request to transfer the next division information data (2) 6 to the block division 1 memory 4 and the D bi A control unit 3. Execute the process described above for Nakushu Soei 2.

By repeating the above sequence once, all the necessary early morning data 6 can be transferred.

As described above, it is possible to transfer all the information data 6 with only one block divided memory 4, and it is possible to reduce the amount of memory used. In addition, the terminal device 2
However, it is sufficient to prepare a receiving memory buffer with the same capacity as the block divided memory 4, and it is also possible to reduce the amount of memory used. This method is particularly effective in a combiner system in which there are many terminal devices that perform DMA transfer.

As described above, the present invention has the effect of reducing memory usage in computers and terminal equipment by adopting a block division transfer method in place of the conventional batch DMA transfer method.

[Brief explanation of the drawing]

The drawing is a schematic diagram showing an embodiment of the present invention. In the diagram (・te, 1...computer, 2...
...Edge device, 3,7...DMA control unit, 4...
...Block division memory, 5...Receiving memory buffer, 6...Information data.

Claims (1)

[Claims] In a system that connects a converter and a number of terminal devices using a DMA transfer method, a block division DMA transfer method between a computer and a terminal device is patented in which information data is divided into multiple blocks and sent.