JPH05334045A - Bus controller - Google Patents

Abstract

PURPOSE:To provide the bus controller which improves the use efficiency of a bus at the time of data transfer between an input/output controller and a peripheral device. CONSTITUTION:This bus controller consists of plural transfer data processing means 1 and 2 which process the data from an input/output controller 10 to output it to peripheral devices 11 and 12 and process the data from peripheral devices 11 and 12 to output it to the input/output controller 10 and a data control part 3 which manages bus occupation flags indicating respective data transfer states of transfer data processing means 1 an 2 and controls the timing of data transfer from transfer data processing means 1 and 2 based on these bus occupation flags.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bus controller,
In particular, it relates to a bus controller for data transfer between an input / output controller and peripheral devices.

[0002]

2. Description of the Related Art A conventional bus controller, which controls data transfer between an input / output controller and a plurality of peripheral devices, occupies the bus when a transfer data is received from the input / output controller and sends the data to a designated peripheral device. The bus was released when all the data was transferred. Further, when the transfer data is received from a certain peripheral device, the bus is similarly occupied, and the bus is released when all the data is transferred to the input / output control device.

That is, for example, as shown in FIG. 3, the second peripheral device 12 is in a standby state while data is being transferred between the input / output control device and the first peripheral device 11. Then, the input / output control device and the first peripheral device 11
When the data transfer between them is completed, the data transfer is started between the input / output control device and the second peripheral device 12, and the first peripheral device 11 is in the standby state during the data transfer.

[0004]

However, in the above-mentioned conventional example, when data is being transferred between the input / output control device and a peripheral device, the bus is not used until the data transfer is completed even if the bus is not actually used. However, there is an inconvenience that the data transfer with other peripheral devices cannot be performed until the previous data transfer is completed and the bus is released.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bus controller capable of improving the disadvantages of the conventional example and improving the utilization efficiency of the bus particularly in the data transfer between the input / output controller and the peripheral device. To do.

[0006]

Therefore, in the present invention, a plurality of transfer data for processing data from the input / output control device and outputting it to the peripheral device and for processing data from the peripheral device and outputting it to the input / output control device. And a data control unit for managing a bus occupation flag indicating a data transfer state of each of the transfer data processing means and controlling a data transfer timing from each transfer data processing means based on the bus occupation flag. Is adopted.
This is intended to achieve the above-mentioned object.

[0007]

[Action]

(1) When data is transferred from the input / output control device to the peripheral device: When the input / output control device outputs the data, the data control unit selects a transfer data processing means that is not in operation and sends the data. The transfer data processing means that has received the data processes the sent data.

When the data control section confirms that the bus occupation flag is not set in the other transfer data processing means, it sets the bus occupation flag in the transfer data processing means and the data processed by the transfer data processing means. To output to the peripheral device. When the data transfer from the transfer data processing means is completed, the bus occupation flag of the transfer data processing means is lowered.

(2) When data is transferred from the peripheral device to the input / output control device: When the peripheral device outputs data, the data control unit selects the transfer data processing means that is not in operation and sends the data. The transfer data processing means that has received the data processes the sent data.

When the data control section confirms that the bus occupation flag is not set in the other transfer data processing means, it sets the bus occupation flag in the transfer data processing means and the data processed by the transfer data processing means. To output to the I / O controller. When the data transfer from the transfer data processing means is completed, the bus occupation flag of the transfer data processing means is lowered.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the embodiment shown in FIG. 1, the data sent from the input / output control device 10 is compressed and output to the first peripheral device 11 or the second peripheral device 12, and the first peripheral device 11 or the second peripheral device is also used. The compressed data sent from the device 12 is expanded and the input / output control device 10
To the first transfer data processing means 1 and the second transfer data processing means 2 and the bus occupancy flag indicating the data transfer state of each of the transfer data processing means 1 and 2, and based on the bus occupancy flag. It comprises a data control unit 3 for controlling the data transfer timing from each of the transfer data processing means 1 and 2.

Here, the first transfer data processing means 1 and the second transfer data processing means 2 have the same configuration and perform the same operation.

The first transfer data processing means 1 is a first buffer 1 for storing transfer data with the input / output control device 10 and the first peripheral device 11 or the second peripheral device 12.
A and the data from the input / output control device 10 stored in the first buffer 1A are compressed and the data from the first peripheral device 11 or the second peripheral device 12 stored in the first buffer 1A It comprises a first data compression / decompression means 1B for decompressing data, and a first compression / decompression control section 1C for controlling the first data compression / decompression means 1B.

The second transfer data processing means 2 stores the transfer data with the input / output control device 10 and the first peripheral device 11 or the second peripheral device 12 in the second buffer 2.
A and the data from the input / output control device 10 stored in the second buffer 2A are compressed, and the data from the first peripheral device 11 or the second peripheral device 12 stored in the second buffer 2A is compressed. It comprises a second data compression / decompression means 2B for decompressing data and a second compression / decompression control section 2C for controlling the second data compression / decompression means 2B.

The data control section 3 sets the first busy flag 1D when the transfer data is sent to the first transfer data processing means 1, and the data compressed / expanded by the first data compression / expansion means 1B. Is transferred to the first buffer 1A
Is empty, the first busy flag 1D is lowered. That is, when the first busy flag 1D is set, the first
The transfer data processing means 1 indicates that it cannot accept new data. Similarly, the data control unit 3 sets the second busy flag 2D when the transfer data is sent to the second transfer data processing unit 2, and the data compressed / decompressed by the second data compression / decompression unit 2B. Is transferred and the second buffer 2A becomes empty, the second busy flag 2D is lowered. That is, when the second busy flag 2D is set, it means that the second transfer data processing means 2 cannot accept new data.

Further, the data control unit 3 stores the data from the peripheral device when the data is expanded and stored in the first buffer 1A, or the data from the input / output control device 10 is compressed and stored in the first buffer 1A. When the data is transferred, the first bus occupation flag 1E is set, and when the data is transferred and the first buffer 1A becomes empty, the first bus occupation flag 1E is lowered. That is, when the first bus occupation flag 1E is set, it means that the first transfer data processing means 1 is transferring data.

Similarly, when the data from the peripheral device is expanded and stored in the second buffer 2A, the data control unit 3 compresses the data from the input / output control device 10 and the second buffer 2A. The second bus occupancy flag 2E is set when it is stored in, and the second bus occupancy flag 2E is lowered when the data is transferred and the second buffer 2A becomes empty. That is, when the second bus occupation flag 2E is set, it means that the second transfer data processing means 2 is transferring data.

Next, the operation of this embodiment will be described. (1) When data is transferred from the input / output control device 10 to the first peripheral device 11 and the second peripheral device 12: Here, the first data and the third data are transferred to the first peripheral device 11.
First, the case of transferring the second data to the second peripheral device 12 will be described.

.. The input / output control device 10 outputs the first data.

[0020]. When confirming that the first busy flag 1D is not set, the data control unit 3 determines that the first transfer data processing means 1 is not in operation, selects the first transfer data processing means 1, and selects the first transfer data processing means 1. The first data is sent to the buffer 1A.

Here, the data control unit 3 sets the first busy flag 1D.

Subsequently, the input / output control device 10 outputs the second data. The data control unit 3 determines that the first transfer data processing unit 1 is in operation because the first busy flag 1D is set, and selects the second transfer data processing unit 2 to select the second transfer data processing unit 2. The second data is sent to the buffer 2A.

Here, the data control unit 3 sets the second busy flag 2D.

[0024]. The first data compression / decompression means 1B is
Under the control of the first compression / expansion control unit 1E, the first data stored in the first buffer 1A is compressed and stored again in the first buffer 1A.

Here, the data control unit 3 sets the first bus occupation flag 1E.

.. When confirming that the second bus occupancy flag 2E is not set, the data control unit 3 determines that the bus is released, and transfers the first data stored in the first buffer 1A via the bus. Transfer to the first peripheral device 11.

When the data transfer is completed, the data control unit 3
Lowers the first busy flag 1D and the first bus occupation flag 1E.

At this time, at the same time, the second data compression / decompression means 2B follows the control of the second compression / decompression control unit 2E.
The second data stored in the second buffer 2A is compressed and stored again in the second buffer 2A.

Then, the data control unit 3 sets the second bus occupation flag 2E.

Subsequently, the input / output control device 10 outputs the third data. Since the first busy flag 1D is not set in the data control unit 3, the first transfer data processing unit 1
Is determined not to be operating, and the first transfer data processing means 1
To send the third data to the first expanded data buffer 1A.

Here, the data control unit 3 sets the first busy flag 1D.

.. When confirming that the first bus occupation flag 1E is not set, the data control unit 3 determines that the bus is released, and transfers the second data stored in the second buffer 2A via the bus. Transfer to the second peripheral device 12.

When the data transfer is completed, the data control unit 3
Is the second busy flag 2D and the second bus occupation flag 2
Lower E.

The first data compression / decompression means 1B is the first
Of the first buffer 1 under the control of the compression / decompression control unit 1E of
The third data stored in A is compressed and stored again in the first buffer 1A.

Here, the data control unit 3 sets the first bus occupation flag 1E.

.. When confirming that the second bus occupation flag 2E is not set, the data control unit 3 determines that the bus is released, and transfers the third data stored in the first buffer 1A via the bus. Transfer to the first peripheral device 11.

When the data transfer is completed, the data control unit 3
Is the first busy flag 1D and the first bus occupation flag 1
Lower E.

That is, as shown in FIG. 2, first the first
While the second transfer data processing means 1 is in compression processing, the second transfer data processing means 2 is on standby, but when the first transfer data processing means 1 is in transfer, the second transfer data processing means 2 is in compression processing. Will be inside. Then, when the first transfer data processing means 1 is in compression processing, the second transfer data processing means 2 is in transfer. Furthermore, when the first transfer data processing means 1 is in the middle of transfer, the second transfer data processing means 2 is in the standby state. In this way, in each transfer data processing means, transfer data compression and transfer are alternately performed.

(2) When data is transferred from the first peripheral device 11 and the second peripheral device 12 to the input / output control device 10: Here, the first data and the third data are the first peripheral device. 11 from the second data to the second peripheral device 12
The case of output from will be described.

.. The first peripheral device 11 outputs the first data.

.. When confirming that the first busy flag 1D is not set, the data control unit 3 determines that the first transfer data processing means 1 is not in operation, selects the first transfer data processing means 1, and selects the first transfer data processing means 1. The first data is stored in the buffer 1A.

Here, the data control unit 3 sets the first busy flag 1D.

Subsequently, the second peripheral device 12 outputs the second data. The data control unit 3 determines that the first transfer data processing unit 1 is in operation because the first busy flag 1D is set, and selects the second transfer data processing unit 2 to select the second transfer data processing unit 2. The second data is stored in the buffer 2A.

Here, the data control unit 3 sets the second busy flag 2D.

.. The first data compression / decompression means 1D is
Under the control of the first compression / expansion controller 1E, the first data stored in the first buffer 1A is expanded and stored again in the first buffer 1A.

Here, the data control unit 3 sets the first bus occupation flag 1E.

.. When confirming that the second bus occupation flag 2E is not set, the data control unit 3 transfers the first data stored in the first buffer 1A to the input / output control device 10.

When the data transfer is completed, the data control unit 3
Is the first busy flag 1D and the first bus occupation flag 1
Lower E.

At this time, at the same time, the second data compression / expansion means 2D follows the control of the second compression / expansion control unit 2E.
The second data stored in the second buffer 2A is expanded and stored again in the second buffer 2A.

Then, the data control unit 3 sets the second bus occupation flag 2E.

Subsequently, the first peripheral device 11 outputs the third data to the bus. The data control unit 3 determines that the first transfer data processing unit 1 is not in operation because the first busy flag 1D is not set, and selects the first transfer data processing unit 1 to store it in the first buffer 1A. The third data is stored.

Here, the data control unit 3 sets the first busy flag 1D.

.. When confirming that the first bus occupation flag 1E is not set, the data control unit 3 transfers the second data stored in the second expanded data buffer 2A to the input / output control device 10.

When the data transfer is completed, the data control unit 3
Is the second busy flag 2D and the second bus occupation flag 2
Lower E.

The first data compression / decompression means 1D is the first
Of the first buffer 1 under the control of the compression / decompression control unit 1E of
The third data stored in A is expanded and stored again in the first buffer 1A.

Here, the data control unit 3 sets the first bus occupation flag 1E.

.. When confirming that the second bus occupation flag 2E is not set, the data control unit 3 transfers the third data stored in the first buffer 1A to the input / output control device 10.

When the data transfer is completed, the data control unit 3
Is the first busy flag 1D and the first bus occupation flag 1
Lower E.

It is also possible to alternately perform data transfer from the input / output control device to the peripheral device and data transfer from the peripheral device to the input / output control device.

In this embodiment, the case where the number of peripheral devices is two has been described, but the present invention is not limited to this.

Further, in the present embodiment, the processing contents in the transfer data processing means are described as data compression and data expansion, but the present invention is not limited to this.

[0062]

Since the present invention is constructed and functions as described above, according to the present invention, data can be transferred between the input / output control device and a plurality of peripheral devices by utilizing the free time of the bus. It is possible to provide an unprecedented excellent bus control device capable of improving the use efficiency of the bus.

[Brief description of drawings]

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

FIG. 2 is a timing chart for explaining the operation of FIG.

FIG. 3 is a timing chart for explaining the operation of the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st transfer data processing means 1A 1st buffer 1B 1st data compression / decompression means 1C 1st compression / decompression control section 1D 1st busy flag 1E 1st bus occupation flag 2 2nd transfer data processing means 2A 2nd expansion data buffer 2B 2nd data compression / expansion means 2C 2nd compression expansion control unit 2D 2nd busy flag 2E 2nd bus occupation flag 3 Data control unit 10 Input / output control device 11 1st peripheral Device 12 Second peripheral device

Claims (2)

[Claims] 1. A bus controller for controlling data transfer between an input / output control device and a plurality of peripheral devices, processing data from the input / output control device and outputting the processed data to the peripheral device, and data from the peripheral device. And a bus occupancy flag indicating a data transfer state of each of the transfer data processing units and managing each of the transfer data processes based on the bus occupancy flag. A bus control device comprising: a data control unit for controlling a data transfer timing from the means. 2. The transfer data processing means processes a buffer for storing transfer data of the input / output control device and each of the peripheral devices, and processes the data from the input / output control device stored in the buffer. 2. A data compression / decompression unit for processing data stored in the buffer from the peripheral device, and a compression / decompression control unit for controlling the data compression / decompression unit. Bus control device as described.