JPH02257357A - Multiplexed system - Google Patents

Abstract

PURPOSE:To enable the close coupling among personal computers by providing an arbitrating circuit which arbitrates a processing request sent from a personal computer to a common bus and a common resource which is connected to the common bus. CONSTITUTION:The respective personal computers 1-1 to 1-N are provided with coupling parts 2-1 to 2-N to obtain system constitution provided with a common-use memory circuit 4, an input/output circuit 5, a distributing circuit 6, the arbitrating circuit 7, and an abnormality detection processing circuit 8. Consequently, the multiplexed system wherein the respective personal computers 1-1 to 1-N are coupled closely can be constituted, and the inexpensive personal computers 1-1 to 1-N which are rich in software property are utilized to structure the system which has the same performance with a large-sized computer system at low cost.

Description

TECHNICAL FIELD The present invention relates to multiplexing systems, and more particularly to multiplexing systems for tightly coupling a plurality of personal computers.

Prior Art Conventionally, there has been no peripheral device for tightly coupling personal computers, and for similar purposes and purposes, a multiplexing system using a surrounding local area network (hereinafter abbreviated as LAN) has generally been used. There is.

In the above-mentioned conventional multiplexing system using a LAN, the multiplexing system is realized by mutual communication between personal computers using a communication line as a medium. As a result, there was no true shared memory or shared input/output devices needed for multiplexed systems. In addition, the access speed is low because it is performed via one or two pairs of communication paths, and the connection form is loosely coupled.

This will be explained using FIG. 3. FIG. 3 shows the configuration of a simple duplex system using a LAN. The figure shows a case where a dual system is configured by an A-system personal computer 9 and a B-system personal computer 11. If one of them fails, the other is controlled to continue processing, thereby improving reliability.

In this case, the data necessary to continue processing is stored in the memories 10.
Must exist on 12. The exchange of data is L
This is realized by mutual communication between personal computers via an AN, which has the disadvantage that there is a time lag and the contents of both memories 10 and 12 do not necessarily match. Furthermore, there was also the drawback that time was lost in mutual communication. For this reason, coupling between computers via LAN is generally classified as loose coupling.

OBJECTS OF THE INVENTION An object of the present invention is to provide a multiplexing system that allows tight coupling between personal computers.

Structure of the Invention A multiplexing system according to the present invention includes: a plurality of personal computers, a common bus to which these personal computers are connected, and an arbitration circuit that arbitrates processing requests sent from the personal computers to the common bus. and a common resource connected to the common bus and commonly accessed by the personal computer.

Example Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of a multiplexing system according to the present invention. In the figure, a multiplex system according to an embodiment of the present invention includes a plurality of personal computers 1-1 to 1-N, coupling circuits 2-1 to 2-N composed of connectors, cables, interfaces, etc., and a system bus. 3, a shared memory circuit 4, a shared input/output circuit 5, a distribution circuit 6 that distributes interrupt messages, an arbitration circuit 7 that arbitrates each request according to priority, and monitors various errors. It is configured to include an abnormality processing circuit 8 that performs recovery processing.

The personal computer l-1-1-N has a coupling circuit 2-
1 to 2-H are connected to the system bus 3.

The system bus 3 includes a shared memory circuit 4 and an input/output circuit 5.
, and a distribution circuit 6 are connected thereto. Also, system bus 3
is monitored and managed by the arbitration circuit 7 and the abnormality processing circuit 8.

In such a configuration, each personal computer 1-1
Requests for access to the shared memory circuit 4 and input/output circuit 5 sent from ~1-N and mutual interrupt message requests between personal computers are arbitrated by the arbitration circuit 7, and one of the requests with a higher priority is selected. system bus 3
is permitted to be used.

A personal computer that is permitted to use the system bus 3 uses the memory circuit 4 when the processing request is to read/write shared data, the input/output circuit 5 when the processing request is for input/output of the shared data 110, and the input/output circuit 5 when the processing request is for reading/writing shared data. For oscillation/termination processing, the distribution circuit 6 can be accessed respectively.

Therefore, in terms of time, common resources such as the memory circuit 4, input/output circuit 5, distribution circuit 6, etc. are always allocated to one personal computer at high speed.

In addition, an abnormality in the system bus 3 may occur, for example, if each personal computer exceeds the usage time of the system bus 3,
Monitoring and recovery processing for the occurrence of parity errors etc. are performed by the abnormality processing circuit 8.

In this way, it becomes possible for each part/nullcomputer to utilize the common resource at high speed and with high reliability.

Further explanation will be given with reference to FIG. FIG. 2 is a schematic diagram showing a system configuration when the multiplex system in FIG. 1 is set to N-6, and parts equivalent to those in FIG. 1 are designated by the same reference numerals.

Since it is N-6, there are six personal computers and the same number of coupling circuits. An interface portion of each coupling circuit, a memory circuit 4, an input/output circuit 5, a distribution circuit 6,
The arbitration circuit 7 and the abnormality processing circuit 8 are housed in one housing 14. Note that the input/output circuit 5 includes a printer (not shown),
It is assumed that a plotter, various reading devices, etc. are connected.

In other words, by configuring a multiplex system as shown in the figure, each personal computer can be tightly coupled and each common resource can be accessed at high speed.

DETAILED DESCRIPTION OF THE INVENTION As described in detail, the present invention has a system configuration that includes a connection section with each personal computer, a shared memory circuit, an input/output circuit, a distribution circuit, an arbitration circuit, and an abnormality detection processing circuit. It is possible to configure a tightly coupled multiplex system of personal computers, and has abundant software assets in the industrial field, where expensive control computers and minicomputers have traditionally been used due to high reliability and limited processing power. This has the effect of making it possible to construct a system with performance equivalent to a large computer system at a low cost by utilizing a large and inexpensive personal computer.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a multiplexing system according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of a multiplexing system according to an embodiment of the present invention.
FIG. 3 is a block diagram of a conventional multiplexing system using a LAN. Explanation of symbols of main parts 1-1 to 1-N...Personal computer 2
-1~2-N...Coupling circuit 3...System bus 4...Memory circuit 5...Input/output circuit 6...Distribution Circuit 7... Arbitration circuit 8... Abnormality processing circuit

Claims (1)

[Claims] (1) A plurality of personal computers, a common bus to which these personal computers are connected, an arbitration circuit that arbitrates processing requests from the personal computers sent to the common bus, and an arbitration circuit connected to the common bus, 1. A multiplex system comprising: a common resource commonly accessed by personal computers;