JPS63245544A - Input/output controller - Google Patents

Abstract

PURPOSE:To perform the input/output control of each of plural input/output devices by controlling the competition for an internal system but to an arbitrary bus control part and controlling the competition for an external system bus to an arbitrary bus control part. CONSTITUTION:An input/output device control part 31a controls the interface between an input/output device 37a and an external device, and an input/output device control part 31b controls the interface between an input/output device 37b and the external device. A bus control part 32a controls the interface between the internal system bus consisting of an address bus A, a data bus D, and a control bus C and the control part 31a, and a bus control part 32b controls the interface between said internal system bus and the control part 31b. A bus competition control circuit 35 controls the competition for the internal system bus, and a bus competition control circuit 36 controls the competition for an external system bus 38. Thus, input/output control of plural input/output devices is performed with one board.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an input/output control device that controls input/output between an external device and an input/output device. It relates to an input/output control device connected to an external system bus.

(Prior Art) In this type of input/output control device, as shown in FIG. It is connected to the external system bus 14.

In this case, the input/output control device t13a is the input/output control device t13a.

13b, 13C... each represent one substrate (hereinafter referred to as
It is configured to control input/output between a large number of input/output devices 15a, 15b, 15c, etc. and external devices such as the central processing unit 11 and memory@112. .

FIG. 3 is a block diagram showing the circuit configuration of a conventional input/output control device. In other words, the conventional input/output control system is
An input/output device control unit 21 that controls the interface between the input/output bag [26 and external device ff (not shown)], an internal system bus (address) connected to this input/output device control unit 21, A bus control unit 22 that controls the interface between buses A, data bus D, and control bus C), an address bus driver/receiver circuit (hereinafter referred to as D/R) 23, and a data bus driver/receiver circuit (hereinafter referred to as (referred to as D/R) 24, a bus contention control circuit 2 that performs bus contention for the external system bus 27;
5, and is configured to control input/output to and from an external device with respect to one input/output device 26.

In the input/output control device having such a configuration, for example, data sent from the input/output device 26 to a storage bag (not shown) is transferred to the external system bus 27 via the input/output device system t1021. In this case, the input/output device control 021 sets the address of the storage device in an address counter (not shown) in the bus controller 22, sets the number of bytes to be transferred in a byte counter (not shown), and then transfers the register(
(not shown).

When data is set in the bus control section 22 in this manner, the bus control section 22 outputs a transfer request signal to the bus contention control circuit 25. Upon receiving this transfer request signal, the bus contention control circuit 25 contends for the bus with other devices connected to the system bus 27 using a bus contention method such as a fixed priority method or a round-robin method. As a result, if the system bus 27 is successfully contested, a transfer permission signal is output to the bus control section 22. This transfer permission signal causes the bus control unit 22 to
The R circuit 23 and the D/R circuit 24 are set to the drive state, and one data bus D is connected to the internal system bus (address bus).
1 control bus C).

In this case, when the specified number of bytes of data transfer is completed, the bus contention control circuit 25
to release.

In this way, conventional input/output control devices have a configuration in which one boat has one input/output control a function, and therefore the number of input/output devices subject to input/output control is limited to one. It was getting worse. However, in recent years, due to technological advances, the number of input/output devices to be controlled has increased, and for this reason, conventional input/output control devices that control one input/output device with a single board cannot handle the increase in the number of input/output devices. At the same time, the number of input/output control devices had to be increased, which was a serious problem.

(Problems to be Solved by the Invention) As described above, the conventional method requires as many input/output control devices as there are input/output devices, which is very problematic.

The present invention has been made in view of the above points, and an object of the present invention is to provide an input/output control device that is capable of controlling input/output of each of a plurality of input/output IAWs on a single board.

[Structure of the invention] (Means and actions for solving the problem) That is,
An input/output control device according to the present invention is an input/output control device that is connected to an external system bus of an external device and performs input/output between the input/output device and the external device. a plurality of input/output device control sections that control respective interfaces of the above, and a plurality of bus control sections that control respective interfaces between internal system buses connected to the plurality of input/output device control sections and the control section, respectively; It is characterized in that it is configured to perform bus contention control for the internal system bus for any bus control unit among the plurality of bus control units, and also perform bus contention control for the external system bus for any of the bus control units. With such a configuration, input/output control of each of a plurality of input/output devices can be performed using a single board.

(Embodiment) Hereinafter, an input/output control device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the circuit configuration of an input/output control device according to an embodiment. That is, this input/output control II device includes two input/output device control sections 31a and 31b, and a bus control section 32 for each of the input/output device control sections 31a and 31b.
a and bus control unit 32b1 address bus driver/
A receiver circuit (hereinafter referred to as a D/R circuit) 33, a data bus driver/receiver circuit (hereinafter referred to as a D/R circuit) 34, a bus contention control circuit 35, and a bus contention control circuit 3G are provided. Two input/output bags @37a
The input/output device 137b is configured to control input/output between each of the input/output devices 137b and an external device (not shown).

The input/output device control unit 31a controls the interface between the input/output device 37a and external devices. Input/output device control unit 31
b controls the interface between the input/output bag @37b and external devices. The bus control section 32a has an address counter, a byte counter, and a transfer register (not shown), and controls an interface between an internal system bus consisting of an address bus A1, a data bus D1, and a control bus C and the input/output device control section 34a. The bus control section 32b controls the interface between the internal system bus and the input/output device control section 3Ib.

The D/R circuit 33 switches between driving and receiving address data. The D/R circuit 34 switches between driving and receiving data. Bus contention control circuit 3
5 performs bus contention control for the internal system bus. The bus contention control circuit 36 performs bus contention control for the external system bus 38.

The operation of the input/output control device configured as described above will be explained below. That is, the input/output device control section 31a
In accordance with the data transferred from the input/output device 137a, the address counter, byte counter,
Set transfer register. When the data is set in the bus control section 32a, the bus control section 32a outputs a transfer request signal to the bus contention control circuit 35. On the other hand, the input/output device control section 31b sets the address counter, byte counter, and transfer register in the bus control section 32b according to the data transferred from the input/output device 37b. When data is set in the bus control unit 32b, the bus control unit 32b
b outputs a transfer request signal to the bus contention control circuit 35.

In this way, the bus control section 32a and the bus control section 3
When a transfer request signal is outputted from each bus 2b, the bus contention control circuit 35 performs bus contention control for the internal system bus based on a bus contention method such as a priority method or a round tropin method.

In other words, the right to use the internal system bus is granted to the bus control unit 32.
A selection is made as to whether to give the signal to the bus controller 32b or the bus controller 32b. When this selection is determined, the bus contention control circuit 35 outputs a transfer request signal to the bus contention control circuit 3G.

By inputting this transfer request signal, the bus contention control circuit 36 performs bus contention control for the external system bus based on a bus contention method such as a priority method or a round tropin method. That is, it is determined whether or not the own device is granted the right to use the external system bus with other devices connected to the external system 38. When the right to use the external system bus 38 has been granted to the device itself, the bus contention control circuit 36 outputs a transfer permission signal to the bus contention control circuit 35.

By inputting this transfer permission signal, the bus contention control circuit 35 outputs a transfer permission signal to the selected bus control unit 32a or 32b, and also outputs a transfer permission signal to the selected bus control unit 32a or 32b.
/R circuit 33 and D/R circuit 34 are set to the drive state. As a result, the selected bus control unit 32a
Alternatively, data transfer is performed via the internal system bus by the bus control unit 32b. When this data transfer is completed, the selected bus control section 32a or bus control section 32b outputs a bus release signal to the bus contention control circuit 35, and the internal system bus is released.

At the same time, the bus contention control circuit 35 outputs a bus release signal to the bus contention control circuit 36, and the external system bus 3
8 is released.

As described above, the input/output control device of this embodiment is configured to control input/output between the two input/output devices and the external 81I unit H by hierarchically contending for the bus. Even if you use the same back panel and board of the same size as conventional ones, it is possible to control two input/output devices with one board.

Furthermore, the bus contention methods for the external system bus and the external system bus do not need to be the same; for example, even if the contention method for the external system bus is system-specific, the internal system You can freely choose the bus competition method. Therefore, by selecting a bus contention method suitable for each input/output device control section, efficient bus use is possible.

Note that this embodiment includes two input/output device control units, and
Although the present invention is configured to perform input/output control of one input/output device, the present invention is not limited to this, and input/output control of a plurality of input/output devices is possible as long as the area of the board allows.

[Effects of the Invention] As described above, according to the present invention, there are a plurality of input/output device control units that control each interface between a plurality of input/output devices and an external device, and a plurality of input/output device control units and the same control unit. A plurality of bus control units are provided that control respective interfaces between internal system buses connected to the plurality of buses 1l.
Since the configuration is configured to perform bus contention control for the internal system bus for any bus control unit in the IIWJ unit and also perform bus contention control for the external system bus for any bus control unit, a single board can handle multiple inputs and outputs. It becomes possible to control the input and output of each device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the circuit configuration of an input/output control device according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the input/output control device connected to an external system bus through a back panel, and FIG. FIG. 3 is a block diagram showing the circuit configuration of a conventional input/output control device. 31a, 31b... input/output device control unit, 32a,
32b - Bus control unit, 33... D/R circuit, 3
4...D/R circuit, 35...Bus contention control circuit, 3
6... Bus contention control circuit, 37a, 37b... Input/output device, 38... System bus, A... Address bus, D... Data bus, C... Control bus.

Claims (1)

[Scope of Claims] An input/output control device that is connected to an external system bus of an external device and controls input/output between an input/output device and the external device, which controls each interface between a plurality of input/output devices and the external device. a plurality of input/output device control units; a plurality of bus control units that control interfaces between the plurality of input/output device control units and internal system buses connected to each of the control units; internal system bus contention control means for controlling the bus contention for the internal system bus with respect to any bus control unit of the system; and external system bus contention control means for controlling the bus contention for the external system bus for the arbitrary bus control unit. An input/output control device characterized by: