JPH01239662A - Bus repeater - Google Patents

Abstract

PURPOSE:To perform a connection operation by a system on the other side even when the system on one side is connected to an intermediate bus by attaching a function to perform logical connection to an extension bus by outputting interface control and data transfer control between a basic bus and the extension bus and a compulsory connection request to the bus repeater of the system on the other side. CONSTITUTION:A compulsory connection command from a CPU on the basic bus 107 is transmitted to a bus repeater control circuit 104 via a basic interface 101. The control circuit 104 receiving the compulsory connection request checks the connection state of another bus repeater via a bus relay interface 106, and outputs the compulsory connection request when another repeater is set at a connection state. After that, after the release of the extension bus 108 is confirmed, the extension bus 108 is connected by a connection interruption circuit 105.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a NonoS relay device for a data processing system, and in particular to an extension provided by a NonoS relay device for another data processing system. share the physical space.

The present invention relates to a bus relay device having a function of constructing an intermediate node of a multiplex system.

[Conventional technology]

Conventionally, in this type of bus relay device, when one bus relay device on an expansion node is connecting an expansion bus, other bus relay devices cannot perform the connection operation.

[Problem to be solved by the invention]

Therefore, in the multiplex system using the conventional bus relay device described above, the system to which the expansion bus is connected stalls for some reason, and the expansion bus must be used by another system. When a situation occurs, if the expansion bus is still connected to the stalled system, other systems will be unable to use the expansion bus.

[Means to solve the problem]

A bus relay device according to the present invention is used in a data processing system in which a central processing unit and a storage device are connected to a basic bus, and an input/output control device is connected to an expansion bus. A bus relay device that logically extends the basic bus by connecting it to the expansion bus, the basic bus interface circuit controlling the interface of the basic bus, and the expansion bus controlling the interface with the expansion bus. an interface circuit; and a bus transfer control circuit that controls transmission of data transfer between the basic bus and the expansion bus.

a bus relay device interface circuit for exchanging information with a bus relay device of another system on the expansion bus and sending a forced connection request to the bus relay device of the other system; and a connection circuit that logically connects the.

〔Example〕 Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a bus relay device according to an embodiment of the present invention.

The bus relay device 100 includes a basic bus 107 and an expansion bus 10.
8. Basic bus interface circuit 1
01 is a circuit that controls the interface with the basic bus 107, and the expansion bus interface circuit 103 is a circuit that controls the interface with the expansion bus 108. The basic bus 107 and the expansion bus 1 are connected via the bus relay device 100.
08, the basic bus interface circuit 101 and the expansion bus interface circuit 103 control the bus transfer on the basic bus 107 and the expansion bus 108, and the bus transfer control circuit 102 controls the bus transfer on the basic bus 107 and the expansion bus 108. From the basic bus 107 to the expansion bus 108 or from the expansion bus 108
Controls data transfer from to the basic bus 107.

The connection disconnection circuit 1o5 is the expansion bus interface circuit 10.
3 to logically connect or disconnect the expansion bus 108 to the bus relay device 100 using a method described later.

The bus relay device interface circuit 106 is connected to a bus relay device interface circuit of another bus relay device,
As will be described later, it is used to transmit information such as read disconnection information of the bus relay device and to transmit a forced connection request.

A forced connection command from a central processing unit (not shown) on the basic bus 107 is transmitted to the bus relay device control circuit 104 via the basic bus interface circuit 101. The bus relay device control circuit 104 that has received the forced connection request checks the connection status of other bus relay devices via the bus relay device interface circuit 106, and if the other bus relay device is in the connected state, A forced connection request is output via the bus relay device interface circuit 106. after that.

After confirming that the expansion bus 108 has been released.

The expansion bus 108 is connected by the connection/disconnection circuit 105 .

FIG. 2 is an example of a duplex system using the bus relay device of the present invention.

Central processing unit 210. Basic bus 200. Storage device 220
# and the bus relay device 230 are set as 1-system devices, and the central processing unit 211. Basic bus 2o1. Storage device 221. And the bus relay device 231 is assumed to be a 2-system device. The input/output control device 240 and the intermediate bus (expansion bus) 2o2 can be used from either the 1st system or the 2nd system, but not at the same time.

Now, the intermediate bus 202 receives a connection command from the central processing unit 210 and connects to the basic bus 202 via the bus relay device 230.
It is assumed that the input/output control device 240 is logically connected to the central processing unit 2100 and is under the control of the central processing unit 2100. At this time,
Even if the central processing unit 211 issues two normal connection commands to the bus relay device 231, no connection operation is performed. If a system stall occurs in the 1-system device including the central processing unit 210 for some reason, the intermediate bus 202 remains connected to the bus relay device 230.

With normal connection commands, it is not possible to connect the intermediate bus from the 2nd system. In this case, the central processing unit 211 issues a forced connection command to the bus relay device 231. The bus relay device 231 that received the forced connection command outputs a forced connection request to the bus relay device 230, and the bus relay device 231 outputs a forced connection request to the bus relay device 230.
0 connects the intermediate bus 202 after releasing it.

〔Effect of the invention〕

As explained above, in a multiplex system incorporating the bus relay device of the present invention, even if one system stalls with an intermediate bus (expansion bus) connected, the other system will not be able to use the intermediate bus. You can continue.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a bus relay device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of a duplex data processing system using the bus relay device of the present invention. 100... Bus relay device, 101... Basic bus interface circuit, IO2... Bus transfer control circuit. 103... Expansion bus interface circuit, 104...
- Bus relay device control circuit, 105... connection disconnection circuit. 106... Bus relay device interface circuit, 107
...Basic bus, 108...Expansion bus, 109...
Interrupt circuit, 200, 201...Basic bus, 2o2.
・Intermediate lotus + 2106211 ``” central processing unit el
p 220 t221...Storage device, 230, 23
1... Bus relay device, 240... Input/output control device. 11be

Claims (1)

[Claims] 1. The central processing unit and storage device are connected to the basic bus,
A bus relay device for logically extending the basic bus by connecting the basic bus to the expansion bus in a data processing system in which an input/output control device is connected to an expansion bus, the bus relay device controlling an interface of the basic bus. a basic bus interface circuit, an expansion bus interface circuit that controls an interface with the expansion bus, a bus transfer control circuit that controls transmission of data transfer between the basic bus and the expansion bus, and another system on the expansion bus. a bus relay device interface circuit for exchanging information with the bus relay device of the other system and sending a forced connection request to the bus relay device of the other system; and a connection for logically connecting the expansion bus in accordance with the forced connection request. A bus relay device comprising a circuit.