JP2768300B2 - Message communication method and method of automatic switching between storage type and immediate type - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and system for message communication between CPUs, such as a measurement control system and a communication device comprising a plurality of CPUs.

[0002]

2. Description of the Related Art In a message communication between CPUs, when a message is delivered to another CPU, the message is transmitted to the other CPU for each message.
An immediate communication method in which a message is issued by an interrupt and a message is individually transferred, and the message is stored in a buffer. The message is transferred to another CPU when the conditions for message transfer (storage buffer full, elapse of a fixed time, etc.) are met. There is a storage-type communication method in which a plurality of messages are delivered collectively by interrupting a request.

[0003] While the immediate communication system has a quick response,
As traffic increases, the overhead per message required for interrupt processing and message switching increases, and the number of messages that can be processed is limited, so that high throughput cannot be realized.

In the storage type communication system, since a plurality of messages are delivered to another CPU at a time, the overhead per message required for interrupts and message switching can be reduced and high throughput can be realized. The response is delayed because no message pickup interrupt is generated in the CPU.

As a specific well-known example, Japanese Patent Laid-Open Publication No. 61-61545, "Asynchronous Communication System of Microcomputer" aims to transmit data asynchronously and efficiently, and monitors the status of data stored in a buffer. When the input data is interrupted, when a predetermined specific code is detected, or when the buffer memory becomes full, the stored data is transmitted in a burst. Both the 4-32922 "interface control circuit" and the 4-4-25062 "inter-processor communication system" are based on a storage-type communication system, and aim to transmit data efficiently when specific conditions are satisfied.

[0006]

In an actual measurement control system or a communication device, a traffic amount is small in a normal operation, and a message is transmitted to a target CPU as quickly as possible when a state change or the like occurs partially. Therefore, the performance of the immediate communication system is required.

However, when an accident relating to the entire measurement control system occurs, a message may be generated at a time and concentrated on a specific CPU. In this case, if communication processing is performed for each message, overhead increases and the overall throughput decreases, so a function of storage-type communication is required.

In other words, the same measurement control system or communication device may require immediate communication or storage-type communication depending on the situation. There are difficulties in monitoring to meet specific conditions with complexity.

An object of the present invention is to monitor the traffic of a message, and when the amount of traffic is small and a change in state occurs partially, an immediate communication system is used, and messages related to the entire system are generated in a concentrated manner. In this case, it is an object of the present invention to provide a storage-type / immediate-type automatic switching message communication method and a method of automatically switching between the immediate-type communication and the storage-type communication in accordance with the traffic situation and improving communication efficiency.

[0010]

SUMMARY OF THE INVENTION According to the present invention, there is provided a message communication method for storing / immediately switching automatically counting message traffic defined by the number of messages processed within a predetermined time in a plurality of message communication methods between CPUs. And when the traffic is within a certain value, the response is switched to an immediate communication in which the response defined by the time required for one message to be transmitted to another CPU is fast, and when the traffic exceeds a certain value, And switching to storage-based communication having a high throughput defined by the total amount of data included in a message that can be processed within the communication.

[0011] Further, the storage type / immediate type automatic switching message communication system of the present invention is a message communication system between a plurality of CPUs, wherein means for counting message traffic defined by the number of messages processed within a predetermined time period, When the traffic is within a certain value, the response is switched to immediate communication in which a response defined by the time required for one message to be transmitted to another CPU is fast, and when the traffic exceeds a certain value, processing can be performed within a certain time. There is means for switching to storage-based communication having a high throughput defined by the total amount of data included in the message.

Further, according to the present invention, there is provided a storage type / immediate type automatic switching message communication system, wherein in a plurality of CPU message communication systems, a message counting unit for constantly monitoring the traffic of a message to be passed to a CPU; A processing determination / execution unit that automatically selects and executes an immediate communication system when the traffic volume is equal to or less than a certain value, and automatically selects and executes a storage communication system when the traffic volume exceeds a certain value. Having.

The message counting section has a message counter corresponding to a plurality of CPUs,
From the traffic monitoring results for U, the immediate communication system is automatically selected and executed when the traffic volume is below a certain value, and the storage communication system is automatically selected and executed when the traffic volume exceeds a certain value. It has a plurality of processing determination / executing units.

The message counting section has a periodic reset instructing section for periodically issuing a reset instruction signal, and an area for storing a counter value before resetting.

[0015]

According to the present invention, in a message communication between a plurality of CPUs, the traffic of a message within a certain time is counted, and when the traffic is within a certain value, the communication is switched to an immediate type communication with a quick response, and the traffic is fixed. When the value exceeds the value, the communication is automatically switched to the accumulation type communication having a high throughput, and the message communication according to the traffic situation is performed.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

The message generated by the transmitting CPU 1 is sent to the message counting section 2. After counting up the message counter 3 for each message that has arrived, the message counting unit 2 delivers the message to the processing determination unit 6. The cycle reset instructing unit 4 periodically instructs the message counting unit 2 to reset the counter. Upon receiving the counter reset instruction, the message counting unit 2 registers the value of the message counter 3 at that time in the pre-reset counter storage area 5, and resets the contents of the message counter 3 to zero.

The processing determining / executing unit 6 compares the value stored in the pre-reset counter storage area 4 (hereinafter referred to as Nt) with a predetermined limit value (hereinafter referred to as Li). Perform automatic switching.

When Nt ≦ Li, the number of processed messages per unit time is equal to or less than the limit value, so that immediate communication is performed. An interrupt for a message pick-up request is input to the receiving CPU 8 for each message. The receiving CPU 8 receives a message one by one every time an interrupt is received.

When Nt> Li, since the number of messages per unit time exceeds the limit value, the storage type communication is performed. A plurality of messages are accumulated in the accumulation buffer 7, and when a message delivery condition is satisfied, an interrupt for a message delivery request is input to the receiving CPU 8. Receiving CP
When U8 receives the interrupt, it receives a plurality of messages accumulated in the accumulation buffer 7 collectively.

Note that the CPU is a CP that can be realized independently.
Naturally, it means a terminal or device incorporating U and a CPU. In addition, it is natural that the communication speeds in the instant communication and the storage communication are arbitrarily selected depending on the implementation system.

[0022]

According to the present invention, when the number of messages to be processed per unit time exceeds a specific value, the mode is switched to the storage type.
Overhead such as receiving side interrupt processing per message is reduced, and the total throughput is improved.

When the number of messages per unit time is small, the mode is the immediate communication mode, and high-speed response communication between CPUs can be performed.

As described above, according to the present invention, the immediate communication having the high-speed response performance during normal traffic and the accumulation-type communication having the high throughput performance during high traffic are automatically and optimally selected according to the operation situation. A high-performance measurement control system and communication device.

[Brief description of the drawings]

FIG. 1 is a diagram showing a method and an apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmission side CPU 2 Message count part 3 Message counter 4 Period reset instruction part 5 Counter storage area before reset 6 Processing judgment and execution part 7 Accumulation buffer 8 Receiving side CPU

Claims (5)

(57) [Claims] 1. A method of communicating messages between a plurality of CPUs, the method comprising: counting traffic of a message defined by the number of messages processed within a predetermined time; and when the traffic is within a predetermined value, one message is replaced by another message. When the traffic exceeds a certain value, the response defined by the time required to reach the CPU is switched to the immediate type communication, and when the traffic exceeds a certain value, the throughput defined by the total amount of data included in the message that can be processed within the certain time is high. A method of communication for automatically switching between a storage type and an immediate type, comprising a step of switching to a storage type communication. 2. A method for counting message traffic defined by the number of messages processed within a certain period of time in a plurality of message communication systems between CPUs, wherein when said traffic is within a certain value, one message is replaced by another message. When the traffic exceeds a certain value, the response defined by the time required to reach the CPU is switched to the immediate type communication, and when the traffic exceeds a certain value, the throughput defined by the total amount of data included in the message that can be processed within the certain time is high. A storage-type / immediate-type automatic switching message communication method characterized by having means for switching to storage-type communication. 3. In a message communication method between a plurality of CPUs, a message counting unit that constantly monitors traffic of a message to be passed to a CPU; A storage type / immediate type automatic switching message, characterized by having a processing determination / execution unit for selecting / executing a communication method and automatically selecting / executing a storage type communication method when the traffic amount exceeds a certain value. Communication method. 4. The message counting unit has a message counter corresponding to a plurality of CPUs, and automatically selects an immediate communication system from a traffic monitoring result for each CPU when a traffic volume is equal to or less than a certain value.・
A storage-type / immediate-type automatic switching message communication method, comprising: a plurality of processing determining / executing units for executing and automatically selecting and executing a storage-type communication method when the traffic amount exceeds a certain value. 5. The storage type / immediate type automatic transmission according to claim 3, wherein said message counting unit has a periodic reset instruction unit for periodically issuing a reset instruction signal and an area for storing a counter value before reset. Switching message communication method.