JPH01205364A - Bus repeater - Google Patents

Abstract

PURPOSE:To control the switching of intermediate bus without using a communicating means between other systems by holding an instruction until other repeating device comes to a disconnected state when other bus repeater is in a connected state. CONSTITUTION:A connect instruction from a CPU is transmitted to a bus repeater control circuit 104 through a basic bus interface control circuit 101. The circuit 104 checks the connection state of the bus repeater of other system through a bus repeater interface control circuit 106. If the bus repeater of other system is in the disconnected state, the circuit 104 controls a connection/ disconnection circuit 105 so as to connect logically an expanding bus 108 to the bus repeater 100. If the bus repeater of other system is in the connected state, the circuit 104 holds the connect instruction as it is, and when the bus repeater of other system goes to the disconnected state on account of some reason, it controls the circuit 105 so as to connect logically the bus 108 to the repeater 100.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a bus relay device for a data processing system, and particularly to a bus relay device for a data processing system that physically shares an expansion bus provided by a bus relay device for another data processing system. , relates to a bus relay device having a function of constructing an intermediate bus of a multiplexed system.

2. Description of the Related Art Conventionally, in this type of bus relay device, even if the disconnection status of other bus relay devices on the intermediate bus is checked, this is only done at the moment when a connection command is executed from the central processing unit. was.

Problems to be Solved by the Invention Therefore, in the multiplexing system using the conventional bus relay device described above, if the expansion bus cannot be connected because the bus relay device of another system is in the connected state when the connection command is executed, In this case, the central processing unit must constantly monitor the bus relay device and check that the other system's bus relay device is disconnected, or the status of the other system's data processing system must be monitored by other communication means. did not become.

The present invention has been made to solve the above-mentioned problems inherent in the conventional technology, and therefore, an object of the present invention is to immediately execute intermediate bus switching control without using communication means between other systems. The object of the present invention is to provide a new bus relay device that makes it possible to do this.

Means for Solving the Problems In order to achieve the above object, a bus relay device according to the present invention includes a basic bus interface control circuit that controls an interface with a basic bus, and a data transfer communication circuit between the basic bus and an expansion bus. A bus transfer control circuit that controls the expansion bus, a connection disconnection circuit that controls the logical connection and disconnection of the expansion bus, and a bus relay device interface circuit that controls the interface with other bus relay devices on the expansion bus. and an interrupt circuit for generating an interrupt to the central processing unit when the central processing unit performs an interrupt, and controls the bus relay device interface circuit according to a connection command from the central processing unit to check the status of other bus relay devices, If another bus relay device is in a disconnected state, the connection disconnection circuit is controlled to connect the expansion bus, and if another bus relay device is in a connected state, the connection command is held until it becomes a disconnected state. It has a function of controlling the connection/disconnection circuit to connect the expansion bus when the connection state is reached, and also notifying the central processing unit of the connection state by means of an interrupt.

Embodiment Next, a preferred embodiment of the present invention will be specifically described with reference to the drawings.6 FIG. 1 is a block diagram showing an embodiment of a bus relay device according to the present invention.

Referring to FIG. 1, the bus relay device 100 is a basic bus 1
07 and an expansion bus 108. The basic bus interface control circuit 101 is a circuit that controls the interface with the basic bus 107, and the expansion bus interface control circuit 103 is a circuit that controls the interface with the expansion bus 108. When transmitting bus transfer between the basic bus 107 and the expansion bus 108 via the bus relay device 100, the basic bus interface control circuit 101 and the expansion bus interface control circuit 103 control the bus transfer between the basic bus 107 and the expansion bus 108. The bus transfer control circuit 102 controls data transmission from the basic bus 107 to the expansion bus 108 or from the expansion bus 108 to the basic bus 107.

The connection disconnection circuit 105 controls the expansion bus interface control circuit 103 to logically connect or disconnect the expansion bus 108 to the bus intermediary device 100.

The bus relay device interface circuit 106 is connected to the bus relay device interface circuits of other bus relay devices, and is used for transmitting information such as the connection status of the bus relay devices.

A connection command from the central processing unit on the basic bus 107 is transmitted to the bus relay device control circuit 104 via the basic bus interface control circuit 101. After receiving the connection command, the bus relay device control circuit 104 checks the connection state of the bus relay device of another system via the bus relay device interface control circuit 106.

If the bus relay device of another system is in a disconnected state, the bus relay device control circuit 104 controls the connection disconnection circuit 105 to logically connect the expansion bus 108 to the bus relay device 100, and It becomes possible to transmit bus transfer between the expansion bus 108 and the expansion bus 108. Further, the interrupt circuit 109 generates an interrupt to notify the central processing unit that the expansion bus 108 has been connected.

If the bus relay device of another system is in the connected state, the bus relay device control circuit 104 holds the connection command as is,
When the bus relay device of another system is disconnected for some reason, the connection disconnection circuit 105 is controlled to logically connect the expansion bus 108 to the bus relay device 100, and the connection between the basic bus 107 and the expansion bus 108 is Bus transfer becomes possible. Furthermore, an interrupt circuit 109 generates an interrupt to notify the central processing unit that the expansion bus 108 has been connected.

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

The basic bus 200.201 is the basic bus 107 in FIG.
Further, the intermediate buses 202 correspond to the expansion lotuses 108, respectively.

The bus relay devices 230 and 231 are similar to the bus relay device 100 described in FIG.

Referring to FIG. 2, central processing unit 210. Basic bus 2
00, the storage device 211 and the bus skewer device 230 are one system device, and the central processing unit 220. The basic bus 201, storage device 221, and bus relay device 231 are two-system devices. The input/output control device 240 and the intermediate bus 202 can be used from either the 1st system or the 2nd system, but not at the same time.

Now, in response to a connection command from the central processing unit 210, the intermediate bus 202 is connected to the basic bus 211 via the HAS relay device 230.
The input/output control device 240 is assumed to be under the control of the central processing unit 210.

At this time, even if the central processing unit 220 issues a connection command to the bus relay device 231, the connection operation is not performed and the connection command is held in the bus relay device 231. Central processing unit 2
If a system stall occurs for some reason in the 1-system devices including 10, the bus relay device 230 becomes disconnected, and the intermediate bus 202 and input/output control device 240
Separated from system control.

When the bus relay bag M231 detects that the bus relay device 230 is in the disconnected state, the bus relay bag M231 transfers the intermediate bus 202 to the basic bus 2.
01, and together with the central processing unit 22.
0 is logically notified that the intermediate bus 202 is connected. Central processing unit 220 begins controlling input/output controller 240 on intermediate bus 202 .

As described in detail, the multiplexing system using the bus relay device of the present invention has the effect of quickly controlling switching of intermediate buses without using communication means between other systems. It will be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a bus relay device according to the present invention, and FIG. 2 is a block diagram showing an example of a duplex data processing system using the bus relay device according to the present invention. 100, , bus relay ¥4 100, 101. , ,
Basic bus interface circuit, 102. , , Bus transfer control circuit, 103, , , Expansion bus interface circuit, 104. , . Bus relay device control circuit, +05. , , Connection disconnection circuit, 106, , Bus relay device interface circuit, 1o7°, , J, I, Main bus, +08. , ,
Expansion bus, 109. , ,interrupt circuit, 200,20
1. , ,Basic bus, 202. , . Intermediate bus, 210.220. , , central processing unit, 2
11°221, , storage device, 2 pieces 10.231.
, , bus relay device, 240. , , Input/Output Control Device Patent Applicant 11 Tree 1 wo Ki Co., Ltd. Representative Patent Attorney Yutabe Kumagai 202: Intermediate Bus 2+0,220: Central Processing Unit 2+1,221: Storage Device 211.2]1: No(S) Central a device 240:
Iride sword at+i shi J2 diagram

Claims (1)

[Claims] In a data processing system in which a central processing unit, a storage device, and an input/output control device are connected to each other by a common input/output bus, a bus relay device that logically extends the common input/output bus, and is a basic common input/output bus. a basic bus interface circuit that controls the interface with the expansion bus; an expansion bus interface circuit that controls the interface with the expansion bus; a bus transfer control circuit that controls transmission of data transfer between the basic bus and the expansion bus; a connection disconnection circuit that controls logical connection disconnection with the expansion bus; a bus relay device interface circuit that controls an interface that exchanges information with other bus relay devices on the expansion bus; and when the expansion bus is successfully connected; and an interrupt circuit for generating an interrupt to the central processing unit, and the connection status of other bus relay devices is determined via the bus relay device interface circuit in response to a connection command from the central processing unit on the basic bus. If the other bus relay device is in the disconnected state, the connection disconnection circuit is controlled to connect the expansion bus, and if the other bus relay device is in the connected state, the expansion bus is connected until the other bus relay device is in the disconnected state. A bus relay device having a function of holding the command, controlling the connection disconnection circuit to connect the expansion bus when a disconnection state occurs, and simultaneously notifying a central processing unit by an interrupt.