JPH01199257A - Data transfer controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data transfer control device that controls data transfer of a plurality of external storage devices connected to a microcomputer.

[Conventional technology]

FIG. 2 is a configuration diagram of a conventional data transfer control device. In the figure, 1 is a microcomputer, 2 is a magnetic disk device as an external storage device, 3 is a magnetic tape device as an external storage device, and 11 is a central processing unit. (CPU), 12
is the main storage device, 13 is the CPU II and magnetic disk device 2
14 is a magnetic tape interface that provides an interface between the CPU 1 and the magnetic tape device 3; 15 is a general-purpose interface for outputting signals to the outside; It is a port.

Here, the CPU 1 has a register IIA inside, and the main memory 12 is composed of a read-only ROM 12A and a RAM 12B that can be freely read and written.

Next, the operation will be explained.

Main storage device 12 consisting of ROM 12A and RAM 12B
When the CPU 11 transfers data in the magnetic tape device 3 to the magnetic disk device 2 according to a program stored in the magnetic tape device 3, the CPU 1 reads the data from the magnetic tape device 3 via the magnetic tape interface 14 and stores it in the register IIA.

Furthermore, the data stored in this register IIA is transferred to RAM1.
2B and stores this data in the RAM 12B.

When all the transfer data is stored in the RAM 12B, the CPU 11 transfers the data to the RAM 12B.
The transfer data is read from 2B and output to the magnetic disk device 2 via 13.

Reading from RAM12B like this, register IIA
A series of operations such as storage in the RAM 12B and writing to the magnetic disk device 2 are sequentially performed, and all the transfer data stored in the RAM 12B is stored in the magnetic disk device 2.

When data is transferred from the magnetic disk device 2 to the magnetic tape device 3, the data is also transferred in the reverse order to the above.

[Problem to be Solved by the Invention] Since the conventional data transfer control device is configured as described above, it is not necessary to always use an expensive CPU and memory even when transferring data during data buffering or restoration. Furthermore, in most computer systems, computer services must be stopped during that time, which poses problems such as a reduction in the utilization efficiency of the computer system.

This invention was made in order to solve the above-mentioned problems, and its purpose is to provide a data transfer device that can transfer data without using a CPU or memory to construct a highly efficient computer system. do.

[Means to solve the problem]

The data transfer control device according to the present invention includes a data transfer device 4 that directly transfers data between the external storage devices 2 and 3, and interposes the data transfer device 4 between the external storage devices 2 and 3, and the data transfer device 4 transfers data. While the central processing unit 1
1 is characterized in that it is provided with access prohibition means 43 for prohibiting access to the external storage device 2.3.

[Effect]

In this invention, the data transfer device 4 is the external storage device 2.
．． Data transfer between the three is performed independently of the central processing unit 11.

While the data transfer device 4 is transferring data, the access prohibiting means 43 prohibits the central processing unit 11 from accessing the external storage device 2.3 to which data is being transferred.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Note that the same components as those in the prior art are given the same numbers and their explanations are omitted.

FIG. 1 is a block diagram of a data transfer control device showing an embodiment of the present invention. In the figure, 4 is the magnetic tough ace 14
It is a data transfer device that intervenes via.

This data transfer device 4 is connected to a port 15.

Further, the data transfer device 4 includes a flag generating means 41 that sets a flag while the data transfer device 4 is transferring data, and the CPU 11 accesses the magnetic disk device 2 and the magnetic tape device 3 in the RAM. In this case, the access control means 42 is provided to control whether or not to prohibit access based on the flag. This flag generating means 41
and access control means 42 constitute access prohibition means 43.

Next, the operation will be explained.

When the CPU II outputs a predetermined signal to the data transfer device 4 via the port 15 or when the transfer start switch attached to the data transfer device 4 is pressed down, the data transfer device 4 transfers data from the magnetic disk device 2 to the magnetic tape. to the device 3 or from the magnetic tape device 3 to the magnetic disk device 2
Start transferring data to.

At this time, the access prohibiting means 43 prohibits the CPU 1 from accessing the magnetic tape device 3 and the magnetic disk device 2.

This access is prohibited, for example, as follows.

First, prior to data transfer, the flag generating means 41 in the data transfer device 4 sets a flag.

When the CPU 1 accesses the magnetic disk device 2 or the magnetic tape device 3, it first refers to the flag of the flag generating means 41 via the port 15 and determines whether access is possible.

The operation of the CPUI 1 is controlled by the access control means 4 in the RAM 12B. When the data transfer by the data transfer device 4 is completed, the flag generating means 41 resets the set flag.

In this case, the data transfer device 4 outputs a signal to that effect to the CPUI 1 via the port 15 at the start and end of data transfer, and the CPU 1
A flag may be set in a register in 1 or at a predetermined address in RAM 12B.

Further, if the end of the tape in the magnetic tape device 3 is detected during data transfer, this is notified to the CPU II and a message code is displayed on the display section of the data transfer device 4. Furthermore, if an error occurs during reading or writing to the magnetic disk device 2 or magnetic tape device 3, the error is notified to the CPU 11 and a message code is displayed on the data transfer device 4.

In the above embodiment, a magnetic disk device and a magnetic tape device are described as objects of data transfer, and the same effects as in the above embodiment are achieved.

〔Effect of the invention〕

As described above, according to the present invention, simple data transfer is configured so that the central processing unit is not directly used, so data can be backed up and restored at high speed, and the system has external storage devices such as multiple magnetic disk devices. If so, they can be performed simultaneously, resulting in a highly efficient computer system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a data transfer control device showing an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional data transfer control device. DESCRIPTION OF SYMBOLS 1... Microcomputer, 2... Magnetic disk device, 3... Magnetic tape device, 4... Data transfer device, 11... Central processing unit (CPU), 12... Main storage device, 41... Flag generation means, 42... Access control means, 43... Access prohibition means. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa (and 2 others) Figure 1

Claims (1)

[Scope of Claims] A data transfer control device comprising a microcomputer having a central processing unit and a main memory device connected to a plurality of external storage devices, wherein the data transfer device directly transfers data between the external storage devices. An access prohibiting means is provided between the external storage devices and prohibits access by the central processing unit to the external storage device while the data transfer device is transferring data. Data transfer control device.