JPH0528081A - Data input/output system for computer - Google Patents

Abstract

PURPOSE:To increase the data input/output rate-between an electronic computer and an external device. CONSTITUTION:An input/output driver 6 is provided with a data length discriminating means 9 which discriminates relations between the data length of input/ output data and a prescribed bit length and an input/output path switching means 10 which switches two paths, namely, the direct path from a CPU 4 and the path passing an input/output channel 7. Data is inputted/ outputted through the input/output channel 7 to increase the input/output speed in the case of input/output of the large data volume, and data is directly inputted/ outputted from the CPU 4 to increase the data input/output speed without command communication between the CPU 4 and the input/output channel 7 in the case of input/output of short data, and these paths are automatically selected to effectively input and output data especially in the case of mixture of data different in bit length.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data input / output system in a computer such as a mini computer which has a relatively large number of input / output to / from external devices.

[0002]

2. Description of the Related Art FIG. 1 is a schematic block diagram showing a data input / output system of a conventional computer. In the figure, 1 is a computer, 2 is a magnetic disk device, an external device such as a display, and 3 is a user's request. An application program created by 4 is a CPU that is hardware that executes various processes in the computer 1, 5 is a data storage device in the computer 1, and 6 is an input / output of data in the data storage device 5 of the CPU 4. I / O driver, which is software that performs processing
7 receives a channel command from CPU 4 and then CP
An input / output channel for inputting / outputting data independently of U4, and 8 is an input / output control device which is hardware.

Next, the operation will be described. When the application program 3 inputs / outputs data to / from the external device 2, generally, unless otherwise specified, the input / output driver 6 is used to input / output data via the input / output channel 7. That is, high-speed data input / output processing by the input / output channel 7 is performed according to the channel command from the CPU 4.

On the other hand, the input / output control device 8 directly from the CPU 4
When data is transferred to the CPU 4, the application program 3 issues a data transfer instruction to the CPU 4 each time data is input or output.

[0005]

As described above, according to the conventional data input / output method, when the data input / output via the input / output channel 7 using the input / output driver 6 is selected by the application program 3, the input / output is performed. Regardless of the data length, all data is transferred via the input / output channel 7, and when direct data transfer from the CPU 4 is selected, the input / output processing by the CPU 4 is executed for all data input / output.

However, when inputting / outputting a large amount of data to / from the same external device 2, data transfer via the input / output channel 7 is performed at high speed and is efficient, but when inputting / outputting a small amount of data, the data is transferred. CPU4 compared to the transfer time
Channel commands due to are time consuming and inefficient,
Direct data transfer from the CPU 4 is inefficient because it takes time to input and output a large amount of data. Therefore, especially when a large amount of data input / output and a small amount of data input / output coexist, the data transfer becomes inefficient, and these data transfer paths are switched according to the input / output data length to efficiently input / output the data. However, there is a problem that the application program 3 becomes very complicated.

The present invention has been made to solve the above problems, and is efficient even when a large amount of data input / output and a small amount of data input / output are mixed without complicating the application program. The purpose is to obtain a computer data input / output system that can transfer data to and from the computer.

[0008]

According to the data input / output method of a computer according to the present invention, a data length judging means for judging the size of the input / output data length with a predetermined bit length and a judgment result of this means are provided. , An input / output path switching means for switching between a direct path from the CPU and a path via the input / output channel.

[0009]

According to the present invention, the data length determining means and the input / output path switching means in the input / output driver cause the path through the input / output channel when inputting / outputting a large amount of data and the CPU when inputting / outputting a small amount of data. The direct route from is automatically selected.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention. In the figure, 1 is a computer, 2 is an external device, 3 is an application program, 4 is a CPU, 5 is a data storage device,
Reference numeral 6 is an input / output driver, 7 is an input / output channel, and 8 is an input / output control device, which are the same as those of the conventional example shown in FIG. 9 is executed as one function of the input / output driver 6,
A data length determination means 10 for determining the size of the input / output data length with respect to a predetermined bit length, a direct path from the CPU 4 and a path via the input / output channel 7 according to the determination result of the data length determination means 9. It is an input / output path switching means for switching between the two paths.

Next, the operation will be described. When the application program 3 gives an instruction to output data to the external device 2, the data length determination means 9 of the input / output driver 6 outputs the data from the data storage device 5 to the CPU.
The bit length of the data after 4 is compared with a predetermined bit length determined by an experiment in advance, and if it is longer than the predetermined bit length, the input / output path switching means 10 selects a path through the input / output channel 7. This data is transferred to the input / output controller 8 via the input / output channel 7. When the data length determining means 9 determines that the data to be output is shorter than the predetermined bit length, the input / output path switching means 10 switches to a direct path not through the input / output channel 7 and the data is directly input / output controller. 8 is transferred.

When inputting from the external device 2, the bit length of the input data from the input / output control device 8 is the data length determining means 9
Is compared with a predetermined bit length, and the CP is directly connected to the path through the input / output channel 7 according to the size of the predetermined bit length.
It is switched to the route to U4.

[0013]

As described above, according to the present invention, the data length determining means for determining the size of the input / output data length with the predetermined bit length and the direct result from the CPU according to the determination result of this means. Since the input / output path switching means for switching between two paths, that is, the path and the path via the input / output channel, is provided, the CPU and the input / output channel can be used when inputting / outputting a short amount of data without reducing the transfer rate when inputting / outputting a large amount of data. There is an effect that a data input / output method can be obtained in which high speed data transfer is possible without the need for receiving and receiving commands between and, and high speed data transfer is possible when data of large and small bit lengths are mixed as in the CAD field.

[Brief description of drawings]

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

FIG. 2 is a schematic configuration diagram showing a data input / output system of a conventional computer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 computer 2 external device 4 CPU 6 input / output driver 7 input / output channel 8 input / output control device 9 data length determination means 10 input / output path switching means

Claims (1)

Claim: What is claimed is: 1. A data input / output method for a computer having a function of inputting / outputting data via two paths, a direct path from a CPU to an external device and a path via an input / output channel. Data of a computer comprising a data length judging means for judging the size of the output data length with respect to a predetermined bit length and an input / output path switching means for switching the above two paths in accordance with the judgment result of this means. Input / output method.