JPH05108536A - Input/output controller - Google Patents

Abstract

PURPOSE:To uniformly execute the mounting check of an input/output device and to prevent the throughput of a central processing unit from being lowered with the mounting check. CONSTITUTION:A mounting check monitor start part 2 periodically starts monitor commands for respective input/output buses 10 and 11 and executes the mounting checks of the input/output devices. Then, the recognition numbers of the input/output devices connected to the respective buses 10 and 11 are acquired. Recognition number registers 3 and 4 receive the recognition numbers of the input 7 output devices acquired by the monitor start part 2 from the monitor start part 2 and hold those numbers, and in this case, however, the register 3 holds the latest recognition number acquired by the monitor start part 2. Then, the old recognition number register 4 holds the last time recognition number acquired by the monitor start part 2. An update detection circuit 5 compares the recognition numbers held in the registers 3 and 4 and when those numbers are different, a prescribed signal is outputted to show the state. At such a time, an interruption generating circuit 6 transmits an interruption signal to a microprocessor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input / output control device which constitutes a computer system.

[0002]

2. Description of the Related Art An example of a conventional microprocessor system is shown in FIG. This system is a central processing unit (CP
U) 201, a memory device (MEM) 202, and an input / output control device 204. The central processing unit 201 and the memory device 202 are connected to the bus 209, and the input / output control device 204 connects the bus 209 to the bus interface (BIF). ) 203 and the channel bus 210. Input / output control devices 204 are connected to input / output buses 5 and 6, and input / output devices (input / output devices 207 and 208) are connected to the respective buses.

In such a system, the central processing unit 201 periodically executes a predetermined monitor command based on the host software stored in the memory device 202, and which input / output device is connected to the input / output buses 205 and 206. It is checked whether it is connected or not, that is, the mounting check of the input / output device.
Then, the mounting table managed by the software is updated according to the result of the mounting check. In the case of a system in which the mounting check is not performed periodically, the INS command / OUS command is executed, and the mounting table is updated based on the result.

[0004]

However, in such a conventional microprocessor system, since the above-mentioned command for mounting check is different for each input / output bus 205, 206, the mounting check is executed in a unified manner. There is a drawback in that the higher-level software becomes complicated because it cannot be done.

Further, since the central processing unit 201 periodically checks the mounting, there is a drawback that its processing capacity is lowered.

The object of the present invention is to eliminate such drawbacks, and it is not necessary to check the mounting of the input / output device for each input / output bus by the upper-level software, and the processing capability of the central processing unit is lowered due to the mounting check. It is to provide an input / output control device capable of avoiding the above.

[0007]

According to the present invention, there is provided an input / output control device which constitutes a computer system and controls a plurality of input / output devices through a plurality of input / output buses. Mounting check means for periodically checking the output device and acquiring its identification number, register means for holding the latest recognition number and the previous recognition number acquired by this mounting check means, and this register means When the latest recognition number and the previous recognition number are different, a device update notifying means for notifying the central processing unit constituting the computer system of the difference is provided.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows an example of an input / output control device according to the present invention. The input / output control device 100 is connected to a microprocessor (not shown) through a channel bus 16 and a bus interface (not shown). Further, input / output buses 10 and 11 are connected to the input / output control device 100, and input / output devices 14 and 1 are connected to these buses, respectively.
5 and input / output devices 12 and 13 are connected.

The mounting check monitor activation unit 2 of the input / output control device 100 periodically activates a monitor command for each of the input / output buses 10 and 11 to check the mounting of the input / output device. Then, the identification numbers of the input / output devices connected to the buses 10 and 11 are acquired. The identification number register 3 is for holding the latest identification number acquired by the monitor starting unit 2, and the old identification number register 4 is for holding the previous identification number acquired by the monitor starting unit 2. ..

The update detection circuit 5 compares the identification numbers held by the registers 3 and 4, and if they are different, outputs a predetermined signal indicating this. The interrupt generation circuit 6 is
When the above predetermined signal is received from the update detection circuit 5,
Send an interrupt signal to the microprocessor.

The channel controller 1 is an input / output controller 100.
The input / output devices have their original functions and are connected to the input / output buses 10 and 11 through the input / output bus interface units 8 and 9 and to the channel bus 16 through the channel interface unit 7.

Next, the operation will be described. The mounting check monitor activation unit 2 periodically activates a monitor command for each of the input / output buses 10 and 11 to check the mounting of the input / output device. Then, the identification numbers of the input / output devices connected to the buses 10 and 11 are acquired. The identification number registers 3 and 4 receive and hold the identification number of the input / output device acquired by the monitor starting unit 2 from the monitor starting unit 2, and the register 3 holds the latest identification number acquired by the monitor starting unit 2. The old identification number register 4 holds the previous identification number acquired by the monitor starting unit 2.

Then, the update detection circuit 5 includes the registers 3 and 3.
4 compares the identification numbers held by them, and if they are different, it means that the I / O devices connected to the I / O buses 10 and 11 have been changed, and a predetermined signal indicating that is output. To do. When the interrupt generation circuit 6 receives the signal, it sends an interrupt signal to the microprocessor to notify the mounted input / output device that a change has occurred.

[0014]

As described above, according to the present invention, in an input / output control device that configures a computer system and controls a plurality of input / output devices through a plurality of input / output buses, the input / output connected to the input / output bus. Mounting check means for periodically checking the device and acquiring its recognition number, register means for holding the latest recognition number and the previous recognition number acquired by this mounting check means, and the latest checking means held by this register means If the identification number and the previous identification number are different,
An apparatus update notifying unit for notifying the central processing unit of the computer system of this is provided.

Therefore, in the input / output control device of the present invention, the central processing unit does not need to execute different monitor commands for each input / output bus to check the mounting of the input / output devices, and the mounting check can be performed in a unified manner. The higher-level software does not become complicated as in the past.
Further, when the device update notifying means notifies the central processing unit of the result of the mounting check by an interrupt, the central processing unit does not need to periodically perform the mounting check, and the processing capacity decreases due to the mounting check. Can be avoided.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of an input / output control device according to the present invention.

FIG. 2 is a block diagram showing an example of a conventional computer system.

[Explanation of symbols]

 1 channel control unit 2 mounting check monitor starting unit 3 old identification number register 4 identification number register 5 update detection circuit 6 interrupt generation circuit 7 channel interface unit 8, 9 I / O bus interface unit 10, 11 I / O bus 12 to 15 input Output device 16 channel bus 100 I / O controller

Claims (3)

[Claims] 1. An input / output control device that constitutes a computer system and controls a plurality of input / output devices through a plurality of input / output buses, wherein the input / output devices connected to the input / output bus are periodically checked, Mounting check means for acquiring the recognition number, register means for holding the latest recognition number acquired by the mounting check means and the previous recognition number, and the latest recognition number held by the register means and the An input / output control device comprising: a device update notifying means for notifying the central processing unit constituting the computer system of the difference from the previous identification number. 2. The device update notifying means notifies the central processing unit by interruption that the latest recognition number held by the register means is different from the previous recognition number. 1. The input / output control device according to 1. 3. The input / output control device according to claim 1, wherein the computer system is a microprocessor system.