JPS63155249A - Inter-equipment communication system - Google Patents

Abstract

PURPOSE:To improve the use efficiency of a common bus by reporting the acceptance state of commands from a transmission-side equipment from a reception-side equipment to the transmission-side equipment and releasing the common bus temporarily. CONSTITUTION:Plural equipment 1-1-1-n consisting of processors, etc., are connected through the common bus 2. The transmission-side equipment obtains the right to use the common bus 2 and sends a command to the reception-side equipment together with the numbers of the reception-side equipment and transmission-side equipment. When the reception-side equipment discriminates the reception-side equipment number and discriminates the command address to the reception-side equipment, it reports the reception state of the command to the transmisstion-side equipment and then releases the common bus 2 temporarily.

Description

[Detailed Description of the Invention] [Summary] When a sending device sends a command to a receiving device via a common bus, the sending device number is added together with the receiving device number, and the receiving device sends the command. By immediately notifying the sending device of the receiving status, even if communication according to the command is not completed between the sending device and the receiving device, the common bus can be temporarily released and communication between other devices can be performed. This allows a common bus to be used for communication.

[Industrial application field]

The present invention relates to an inter-device communication system in which a plurality of devices such as processors are connected by a common bus, and communication is performed between arbitrary devices via the common bus.

In a multiprocessor system, multiple processors are connected via a common bus, and only the processor that has acquired the right to use the common bus specifies the receiving processor via the common bus and communicates with it. be able to.

In this case, it is desired to be able to use the common bus effectively.

(Prior Art) In a conventional system in which devices such as a plurality of processors are connected via a common bus, for example, as shown in FIG. Then, a bus competition circuit or the like performs competition processing for requests to use the common bus, and permission to use the common bus is granted. The sending device A, which has been given usage permission, sends out a command consisting of, for example, receiving device number RDN+order.

The receiving device B specified by the receiving device number RDN in this command takes in the command, and in the case of a write command, data is sent from the sending device A as shown by the dotted line, and the receiving device B receives the data. Then, a reception notification is transmitted from the reception side device B to the transmission side device A as shown by the dotted line, and with this reception notification, communication between the devices is completed and the common bus is released. In the case of a read-related command, the receiving device B collects the data and sends it to the transmitting device A, and upon receiving the data, the transmitting device A releases the common bus as a completion of inter-device communication.

Common bus contention processing is generally handled by a bus contention circuit, which includes a configuration in which permission to use the common bus is granted via an individual control line to a device that has requested use of the common bus, and a system that uses a bus contention circuit. In this configuration, devices are connected in series, and permission signals for use of a common bus are transferred in sequence, and the closer the device is connected to the bus contention circuit, the higher the priority is given to the device, giving permission to use it. Are known. Also, a system in which one processor serves as a main processor and processes requests for use of a common bus from other processors;
Alternatively, systems are known in which the function of the main processor is sequentially delegated.

[Problem that the invention seeks to solve]

When sending device A sends a read-related command to receiving device B, and sending device A reads data from receiving device B, receiving device B, which has received the read-related command, collects data according to the command. Edit the data,
It will be sent to the sending device A. Therefore, it takes some time, and even during that time, the common bus is occupied, so communication between other devices has to wait until the communication between devices is completed. was there.

An object of the present invention is to improve the efficiency of use of a common bus that connects a plurality of devices, thereby improving the conventional drawbacks.

[Means for solving problems]

The device-to-device communication method of the present invention shortens the wasted time occupied by a common bus to allow communication between devices.
This will be explained with reference to FIG. FIG. 1 is a block diagram of an embodiment of the present invention, in which a plurality of devices 1-1 to 1-n including processors etc. are connected via a common bus 2, and a bus contention circuit 3 provides access to the common bus 2. A system in which competition processing is performed and a common memory 4 is connected to a common bus 2 is shown. In addition, when communicating between devices, the sending device adds the sending device number to the command and sends the command, and after receiving the command, the receiving device immediately reports the command reception status to the sending device. When sending data from the receiving device to the sending device using read-related commands, the command should include the following information: Based on the added transmitting device number, data is transmitted from the receiving device to the transmitting device via the common bus 2.

[Effect]

The receiving device that receives the command with the receiving device number and the sending device number notifies the sending device of the command acceptance state, and the sending device receives the notification and releases the common bus. In the case of a read-related command, the receiving device memorizes the sending-side device number, and when the data corresponding to the read-related command is collected, it can call the other device using the stored sending-side device number. Specify the data and send it. Therefore, in the case of a read-related command, the common bus is temporarily released by notifying the reception of the command, and the common bus can be used for communication between other devices until data based on the command is transmitted.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention.
1 to 1-n are connected to the common bus 2 via drivers and receivers (not shown), and are also connected to the bus competition circuit 3 via control lines. Each device requests the bus contention circuit 3 to use the common bus 2 via the control line, and permission to use the common bus 2 is granted via the control line through contention processing. When a device that has been granted permission to use this common bus 2 sends a command, as shown in Figure 2,
A command in a format consisting of a receiving device number RDN, a sending device number SDN, and an order is formed and sent to the common bus 2.

In addition, each device 1-1 to l-n has the function of sending and receiving data, and when sending a command, the receiving device number RDN, which is the partner device number, and the sending device number SDN, which is the own device number.
and an order as shown in FIG. 2; means for receiving and identifying the receiving device number RDN in the command; and receiving and holding the transmitting device number SDN in the command until communication is completed. and means for immediately notifying the sending device of the command reception status upon command reception, and these means can be easily realized by a program-controlled processor equipped with registers, comparison means, etc. be able to.

FIG. 3 is an explanatory diagram of the operation of the embodiment of the present invention, and shows a case where a sender device A sends a read command to a receiver device B, and the sender device A requests the use of the common bus 2 due to bus conflict. Send to circuit 3.

In response to this usage request, the bus competition circuit 3 performs competition processing based on the time relationship or priority order with usage requests from other devices, and grants permission to use the common bus 2 to the usage requesting device.

The sending device A, which has been given permission to use the common bus 2, sends out a command consisting of a receiving device number RDN, a sending device number SDN, and an order, as shown in FIG. When receiving device B identifies the receiving device number RDN and determines that the command is addressed to its own device, it takes in this command and immediately issues a command indicating whether or not it can respond to this command. The reception status is notified to the sending device A. Also, the sending device number SDN in the command is held in a register or the like.

When the sending device A receives the notification of the command acceptance state from the receiving device B, the sending device A releases the common bus 2. Therefore,
Although communication according to a read-related command is not completed, the common bus 2 is temporarily released so that it can be used for communication between other devices.

The receiving device B analyzes the read command, collects and edits the data, and when the data is ready to be sent, sends a request to use the common bus 2 to the bus contention circuit 3. Send. When permission to use it is granted from the bus contention circuit 3 to the receiving device B,
The receiving device B forms a data transmission destination based on the transmitting device number S DN previously received and held in a register or the like, and sends the data via the common bus 2.

The sending device A receives this data and, if there is no error, notifies the receiving device B of completion of reception, and the receiving device B releases the common lotus 2 accordingly.

On the other hand, in the case of a write command, data can be received following the command, so the receiving device B analyzes the command, captures the received data, and sends a command reception status notification containing the result to the sending device. Send to A.

When the sending device A receives the command acceptance status notification from the receiving unit WB, it releases the common bus 2 and ends the communication.

Note that the competition processing for the common bus 2 can be performed by various conventional competition processes other than the bus competition circuit 3, as described above.

〔Effect of the invention〕

As explained above, in the present invention, a plurality of devices 1-1 to 1-n including processors etc. are connected via the common bus 2, and the sending device acquires the right to use the common bus 2 and receives data. The receiving device number and the sending device number are added to the command sent to the side device, and the receiving device identifies the receiving device number and identifies the command addressed to its own device, and then checks the reception status of this command. A notification is sent to the sending device, thereby temporarily releasing the common bus 2. Therefore, even if it takes a long time to collect data from the receiving device using a read command, it is possible to temporarily release the common bus 2 and use the common bus for communication between other devices. improves usage efficiency.

Also, the sending device number included in the command is received and retained, and when sending data for read commands,
Since the data transmission destination can be formed based on this sending device number, even after the common bus 2 is released,
The data can be sent to the sending device that has requested to read the data. Therefore, the common bus 2 can be used effectively and a system with high processing capacity can be constructed.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is an explanatory diagram of a command format of an embodiment of the invention, Fig. 3 is an explanatory diagram of operation of an embodiment of the invention, and Fig. 4 is a conventional device. FIG. 1-1 to 1-n are devices, 2 is a common bus, 3 is a bus contention circuit, and 4 is a common memory.

Claims (1)

[Claims] A system in which a plurality of devices (1-1) to (1-n) are connected via a common bus (2) and communication is performed between the devices via the common bus (2). The sending device obtains the right to use the common bus (2) and sends a command to the receiving device with the sending device number added to the command, and the receiving device adds the sending device number to the command to the receiving device. Identifying that the command is addressed to the own device by the receiving device number, and notifying the sending device of the reception status of the command, and upon the notification, the sending device temporarily releases the common bus (2). , when the receiving device transmits return data corresponding to the command to the transmitting device, it acquires the right to use the common bus (2) and transmits the data according to the received and held transmitting device number. An inter-device communication method characterized by transmitting data to a sending device.