JPH02144750A - Input/output device for unit record system - Google Patents

Abstract

PURPOSE:To realize a switch means which can be easily operated by providing a switch control means that can secure the connection for only one of plural input/output controllers via an exclusive interface. CONSTITUTION:A CONO signal requesting the connection to a system 0 is outputted after confirming the inactive state of a BSYO signal. An E/F is set with the output of the CONO signal and X is outputted to a switch control circuit SWC 100. Receiving the X, the SWC 100 gives the control output to a switch SW 101 which performs the actual line switching actions. As a result, an input/output control unit IOCB of the system 0 is connected to an input/ output unit IOU 7. Thus the unit IOU 7 is available to the processing of a system 0. Under such conditions, the BSYO and 1 signals are produced with an OR secured between the X and Y outputs and a DBSY signal showing whether the process of the unit IOU itself is through or not. Thus it is possible to inform the unit IOCB of the system 1 of a fact that the connection is impossible with the unit IOU 7.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an input/output device having a function of exclusively switching and connecting a plurality of input/output devices, and particularly to a switching control method for the function.

ijC Conventional technology Conventionally, this type of input/output device has a configuration as shown in FIG.
B) Signals a and b of 44 and 54, respectively, are connected to a switching unit (SWU) 46, which
6 connects either the input/output control unit 44 or 54 to the input/output control unit (IOjJ) 47, and this switching control is performed by connecting the other input/output control units (IOCΔ) 43 and 53 and these Switching is performed by providing in the switching unit 46 a circuit equivalent to the interface circuit included in the input/output control units 43 and 53.

Next, the prior art will be explained in detail with reference to FIG. Does Figure 4 precede the present invention? FIG. 2 is a block diagram for explaining the IE technology.

In the figure, 41 and 51 are memory unit l-(MEM) 42
Execution units (EPUs), 44 and 54, which perform various data processing using programs expanded in , a and 52;
is an input/output control unit (IOCB) that is connected one-to-one with the normal input/output bag z<l01)) +1!5 and controls the input/output device 45, and 43 and 53 are switching units (S
Wt, l) An input/output control unit (IOc) having a general-purpose interface function for controlling 46 switching operations.
A) is shown respectively. Input/output control units 1 to 44 and 5
The four data/control signals a and b are switched by the switching unit 46 by the control outputs C and d from the input/output control units 43 and 53, and are output to the input/output unit h (+00
) 47, and the input/output crab unit 47 operates according to operation instructions from the input/output control unit 44 or 54 on the connected side.

Problems to be Solved by the Invention The conventional unit record type input/output devices described above often use a general-purpose interface such as R5232C for switching control, which increases the amount of additional hardware and complicates control. It has the disadvantage of becoming.

The present invention has been made in consideration of the above-mentioned conventional situation,
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to eliminate the above-mentioned drawbacks inherent in the conventional technology and to provide a new unit record type input/output device having switching means that is easy to operate and control.

Means for Solving the Problems In order to achieve the above object, a unit record type input/output device according to the present invention includes an input/output control device that operates according to instructions from a central processing unit in an information processing system, and an input/output control device that operates according to instructions from a central processing unit in an information processing system. In relation to a unit record type input/output device connected to the device, the input/output device has means for connecting π of the plurality of input/output devices, and only one of the plurality of input/output control devices The switching control means can be connected to the input/output device exclusively through a simple interface, and the switching control means can perform simple switching using three signals for connection instruction/disconnection instruction/connection status confirmation. Works with the interface.

Embodiment Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings.

The present invention does not use the input/output control units (IOCA) 43 and 53 having general-purpose interfaces as shown in FIG. 4, but by adding a simple interface circuit in the switching unit (SWU) 46. , the switching unit 46 can be easily controlled.

FIG. 1 is a block diagram showing an embodiment of a portion related to switching control of the present invention.

Referring to FIG. 1, input/output control units 4a, 14a
The I/F section in the switching control circuit 8 is an interface circuit according to the switching control method of the present invention. Details of this interface circuit will be explained with reference to FIGS. 2 and 3.

In Fig. 2, first, the O system input/output control unit 1-10
c When connecting B to the input/output crab unit (IOU) 7, the signal BSYO indicating that the input/output control unit IOCB on the 1st system side is connected to the input/output crab unit (+01) 7 and is in use must not be active. After confirming this, it outputs a CON O signal requesting connection to the 0 system.

This output sets the flip-flop F/F and causes the switching control circuit (SWC) 100 to
is output, and the switching control circuit (SWC) 10 receives it.
0 provides a control output to a switch (SW) 101 that actually switches lines. This operation connects the 0-system input/output control unit IOCB and the input/output crab unit (IOU) 7, so that the input/output crab unit (IOU) 7 can be used for the 0-system processing. At this time, in order to notify the input/output control unit IOCB of system 1 that the input/output unit (IOU) 7 cannot be connected, BSY O and B
SY l 1g has X and Y output and input/output crab unit IO
It is created by ORing with DBSY, which indicates whether U's own processing has been completed, and is designed to avoid that the state of the input/output crab unit IOU is not inoperable when notifying the other system of permission to use switching. There is.

As described in detail, according to the present invention, an easy-to-operate switching means can be provided by implementing a part that was conventionally complicated and required a lot of additional hardware with a simple interface circuit. is obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a circuit block diagram showing the switching control interface in this embodiment, and FIG. 3 is a supplementary explanation of FIG. 2. FIG. 4 is a block diagram for explaining the prior art related to the present invention. 4a, L4a, 44.54・I/O control unit B, 5
a, 45... Input/output device, 6a, 46... Switching unit, 7.47... Input/output crab unit, 8.100... Switching control circuit, 9.101... Switching device, 41.51...
Execution unit, 42.52... Main memory unit, 43
．． 53... Input/output control unit A, a, b, c, d...
・Data/control line, 11, lla... switching control line, X
, Y...Busy control line. Patent applicant: NEC Co., Ltd. Agent: Patent attorney Yutabe Kumagai BSY Figure No.

Claims (1)

[Claims] In the relationship between an input/output control device that operates according to instructions from a central processing unit in an information processing system and a unit record type input/output device connected to the input/output control device, there are multiple input/output devices in the input/output device. It is characterized by having a means for connecting a control device, and a switching control means that allows only one of the plurality of input/output control devices to be exclusively connected to the input/output device using a simple interface. Unit record input/output device.