JP2758752B2 - Common bus contention arbitration method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a common bus contention arbitration system, and more particularly to a priority determination system.

[0002]

2. Description of the Related Art Conventionally, this type of common bus contention arbitration system employs common bus use request devices 310 and 3 as shown in FIG.
In this system, the priority is determined based on only the common bus use requests 420 or 380 to 380 or the common bus use request 420 and the common bus use status of the common bus use request device, and the use permission is given.

[0003]

In the above-mentioned conventional common bus contention arbitration system, the common bus contention arbitration device gives a use permission only with use request information of the common bus use request device. When the common bus use requesting device is busy communicating with another common bus using device, the effective traffic amount of the common bus decreases. In addition, there is a disadvantage that it is difficult to disconnect when the partner common bus using device has a failure.

[0004] It is an object of the present invention to provide a common bus contention arbitration system for preventing a communication request generated without knowing a busy state or a failure of a partner device and improving the use efficiency of a common bus.

[0005]

According to the common bus contention arbitration system of the present invention, one common bus contention arbitration device and a plurality of common bus use devices are connected to a common bus, and the common bus contention arbitration device is a central processing unit. And an electronic switching system connected by a control bus, the common bus using device has a common bus use request transmitting circuit for adding a common bus use device information of a communication partner to a common bus use request, and the bus contention arbitration. The apparatus receives a common bus use request to which communication destination information is added, and extracts a request source information and a destination information, and stores a common bus use request receiving circuit, and stores the extracted request source information and the destination information. A common bus communication information holding circuit which measures the time until the common bus use permission given in response to the common bus use request is again given to the same partner common bus using device. A common bus use permission control circuit for fixedly limiting a time interval for giving the common bus use permission for each other by the measurement result and the other party information output by the bus communication information holding circuit and the common bus use permission information; To limit continuous and intensive communication requests to a specific common bus using device.

A control bus interface circuit for communicating with the central processing unit to the common bus contention arbitration unit, and a time period for granting the common bus use permission for each destination is controlled by the central processing unit. A common bus use permission time control circuit for limiting the time for each bus use device.

[0007]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is an internal block diagram of the common bus contention arbitration apparatus of FIG.

[0008] The block diagram of FIG. 1 is a common bus using device 310, 320-380 = 8 units for performing mutual data communication).
A central processing unit 100 for performing initial setting, change control, and the like,
It comprises a common bus contention arbitration device 200 for congestion arbitration of common bus use requests from the common bus use devices 310, 320, to 380, and a common bus 400, and a control bus 500. Competition arbitration device 2
00 and the common bus using devices 310 to 380 are the control bus 5
00 is connected. In addition, the common bus using device 31
0, 320 to 380 are connected by a common bus 400. The common bus 400 includes a data + control signal 410, a common bus use request signal 420, and a common bus use permission signal 430.
It consists of. The common bus use permission signal 430 of the common bus 400 is also connected to the common bus contention arbitration device 200.

[0009] Common bus using devices 310, 321, -38
0 is a common bus use request transmission circuit 311, 321, to 381 for adding destination information to the common bus use request, respectively.
As shown in FIG. 2, the common bus contention arbitration apparatus 200 has a common bus use request receiving circuit 210, and common bus communication information for extracting and storing request source information and other party information from the common bus use request receiving circuit 210. The holding circuit 220, the time measuring circuit 230 for measuring the time until the common bus use permission given in response to the common bus use request is given again to the same partner common bus using device, and the communication circuit with the central processing unit 100. The control bus interface circuit 260, the common bus use permission control circuit 250 for fixedly limiting the time for granting the common bus use permission for each destination, and the time for granting the common bus use permission for each destination is limited for each common bus use device. And a common bus use permission time control circuit 240.

Next, the function of each circuit and the common bus will be described with reference to FIGS. The common bus 400 is a bus for performing communication among the common bus using devices 310, 320, to 380, and the data + control signal 410 is data and control signals for communication. The common bus use request signal 4
Reference numeral 20 denotes each of the common bus using devices 310, 320, to 380.
Is a use request signal of the data + control signal 410 when communication is performed using the data + control signal 410, and is composed of 4 bits.
And is input to the common bus contention arbitration apparatus 200. FIG. 3 shows an example of the common bus use request signal 420. The common bus use permission signal 430 is time-divided and becomes effective only in one cycle, and the common bus use permission signal 430 is active for the corresponding common bus use device among the common bus use devices 310, 320, to 380. The data + control signal 410 can be used only during the period. FIG. 4 shows an example of the common bus use permission signal 430. (In FIGS. 4 and 5, the device numbers are temporarily A to H.)

The common bus use request transmission circuits 311, 321, and 381 of the common bus use devices 310 to 380 are connected to the common bus of the common bus use permission request signal 420. Active signal to common bus to common bus use request signal 420
Send the destination number. The common bus use request receiving circuit 210 of the common bus contention arbitration device 200 receives the common bus use request signal 420 transmitted from each of the common bus use devices 310, 320 to 380, and outputs the request source device number and the destination device number. Create information.

The common bus communication information holding circuit 220 receives and holds the information of the request source device number and the destination device number from the common bus use request receiving circuit 210, and shares the request source device number and the destination device number. It notifies the bus use permission time control circuit 240, the common bus use permission control circuit 250 and the control bus interface circuit 260 as necessary.

The time measurement circuit 230 includes a contention arbitration circuit 27
Based on the information of the common bus use permission signal 430 received by 0, the time until the common bus use permission is again given to the same partner common bus use device is measured. The time of each partner measured by the time measuring circuit 230 is notified to the common bus use permission time control circuit 240 and the common bus use permission control circuit 250 as necessary.

The common bus use permission control circuit 250 is based on the counterpart device number information from the common bus communication information holding circuit 220, the measured time from the time measurement circuit 230, and the common bus use permission information from the contention arbitration circuit 270. The contention arbitration circuit 270 is restricted so that communication to the same device does not occur within a predetermined time. The time limit is fixed systematically, and the change is performed by information from the control bus interface circuit 260.

The common bus use permission time control circuit 240
The function is the same as that of the common bus use permission control circuit 250, but operates so that the time limit can be changed for each common bus use device based on information from the control bus interface circuit 260. Based on the restriction control information, time restriction control is performed on the common bus use permission for each destination common bus using device. The control bus interface circuit 260 receives control information from the central processing unit 100 from the control bus 500. The control bus interface circuit 260 controls the common bus use permission time control circuit 240 and the common bus use permission control in the common bus contention arbitration device 200 according to the control information. Circuit 250
Initial setting, status change and reading.

The contention arbitration circuit 270 receives the common bus use request signal 420 received by the common bus use request reception circuit 210.
To the common bus. When a plurality of common bus use requests occur simultaneously, one of them is selected and the common bus use permission is given. Permission to use the common bus
The selection is made based on the same device permission restriction information from the common bus use permission control circuit 250 and the use permission restriction control information from the common bus use permission time control circuit 240. The same device permission restriction information from the common bus use permission control circuit 250 and the use permission restriction control information from the common bus use permission time control circuit 240 are used for the common bus use permission time control circuit 240.
The use permission restriction information from is given priority.

The result of the contention arbitration performed by the contention arbitration circuit 270 is notified to the time measurement circuit 230, the common bus use permission time control circuit 240, and the common bus use permission control circuit 250. Also, each of the common bus using devices 310, 320,
To 380 are notified by the common bus of the common bus use permission signal 430 of the common bus 400.

Next, the operation will be described. The common bus use devices 310, 320, to 380 use the common bus use request transmission circuits 311 and 32 when it is desired to use the common bus 400.
1 to 381, the other party's common bus use request signal 420 is transmitted to the common bus contention arbitration device 200 for notification. The common bus contention arbitration device 200 performs contention arbitration in the contention arbitration circuit 270 based on the common bus use request signal 420 received by the common bus use request reception circuit 210, and transmits the arbitration result to the common bus of the common bus use permission signal 430. It notifies each common bus using device 310-380.

Further, a plurality of common bus using devices 310, 3
When communication requests are concentrated on one common bus using device from 20 to 380, use permission for the common bus using device is restricted for a certain period of time, and communication to another common bus using device is prioritized. FIG. 5 shows an example of the operation. At a certain time, when a communication request for the common bus using device E is issued to both the common bus using device numbers C and G, and then a communication request for the common bus using device A is issued from the common bus using device number B, The common bus contention arbitration device 200 gives a common bus use permission to the used device number C. Since communication with the common bus using device number E is restricted in the common bus contention arbitrating device 200 for a certain period thereafter, at the time when the communication with the common bus using device number C ends,
The common bus contention arbitration device 200 gives the common bus use device number B a common bus use permission even though the common bus use device number G requests communication before B.

[0020]

As described above, according to the present invention, the common bus contention arbitration device recognizes the other device using the common bus, so that when the traffic is concentrated on a small number of devices using the common bus, the degree of concentration can be reduced. By restricting the use permission according to the request, it is possible to reduce the invalid traffic due to the busy of the other party, increase the effective traffic amount of the entire bus, and use the bus efficiently. Also, by obtaining the monitor information from the common bus contention arbitration device in the central processing unit, the traffic condition of the common bus can be recognized, and there is an effect that the congestion state and the failure can be found. Has the effect that the traffic on the bus can be manipulated. Further, when the communication using the common bus is impossible due to the failure of the partner common bus using apparatus, the common bus use permission is not given to the communication to the failed common bus using apparatus, so that the communication can be disconnected from the common bus. Can be used efficiently and fault tolerance is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a block diagram of the common bus contention arbitration device of FIG. 1;

FIG. 3 is a time chart illustrating an example of a common bus use request according to the present embodiment.

FIG. 4 is a time chart illustrating an example of a common bus use permission according to the present embodiment.

FIG. 5 is a time chart for explaining the operation of this embodiment.

FIG. 6 is a block diagram of a conventional example.

[Description of Signs] 100 Central Processing Unit 200 Common Bus Contention Arbitration Device 210 Common Bus Use Request Receiving Circuit 220 Common Bus Communication Information Holding Circuit 230 Time Measurement Circuit 240 Common Bus Use Permission Time Control Circuit 250 Common Bus Use Permission Control Circuit 260 Control Bus interface circuit 270 Competition arbitration circuit 310 to 380 Common bus use device 311 to 381 Common bus use request transmission circuit 400 Common bus 410 Data + control signal 420 Common bus use request signal 430 Common bus use permission signal 500 Control bus

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06F 13/362 G06F 13/372

Claims (2)

(57) [Claims] 1. A single common bus contention to the common bus arbitration device and a plurality of common bus devices are connected, in the common bus contention arbitrator electronic replacement scan Temu connected by a control bus a central processing unit, The common bus use device has a common bus use request transmission circuit for adding a common bus use device information of a communication partner to a common bus use request, and the bus contention arbitration device has the communication partner information added. A common bus use request receiving circuit that receives a common bus use request and extracts request source information and destination information, a common bus communication information holding circuit that stores the extracted request source information and destination information,
The time until the common bus use permission given in response to the common bus use request is again given to the same destination common bus using device is measured, and the measurement result and the destination information output by the bus communication information holding circuit are measured. And a common bus use permission control circuit for fixedly restricting a time interval at which the common bus use permission is given for each destination based on the common bus use permission information. A common bus contention arbitration method characterized by restricting communication requests that occur in a network. 2. A control bus interface circuit for communicating with the central processing unit to the common bus contention arbitration device, and a time period for granting the common bus use permission for each destination is controlled by the central processing unit. 2. A common bus contention arbitration system according to claim 1, further comprising a common bus use permission time control circuit for limiting time for each bus use device.