JP2003218874A - Creating method for information on communication rate among electron equipment, acquiring method therefor and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acquiring method for information on communication rate among electron equipment capable of using efficiently a band eliminating useless communication by creating a rate map in a short time. <P>SOLUTION: The acquiring method comprises a step of acquiring information on a maximum communication rate of each electronic equipment from self identifier information transmitted from the electronic equipment at the bus reset time (step 204), a step of acquiring information on a maximum intercommunication rate among master nodes and self nodes by selecting a less rate in comparison with the maximum communication rate of the master nodes and the maximum communication rate of the self nodes (step 205), and a step of determining information of a maximum intercommunication rate among higher order nodes and self nodes by selecting less rate in comparison with the information the maximum intercommunication rates among higher order nodes than self nodes and information on maximum intercommunication rate of the self nodes (step 206). The method repeats these steps and creates a map of a maximum communication rate. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for creating communication speed information between electronic devices, a method for acquiring communication speed information between electronic devices, and a recording medium, and more particularly to a method for creating communication speed information between electronic devices connected to an IEEE 1394 serial bus. And a method for acquiring communication speed information between electronic devices, and a recording medium recording a program for implementing these methods.

[0002]

2. Description of the Related Art In 1995, the IEEE (Institute of Electrical and Electronics Engineers) adopted IEEE 1394 as a standard specification for a high-speed serial interface. This IEEE
The 1394 system provides multimedia information such as moving images, still images, voice and character data to a computer, a peripheral device, a general AV such as a digital video camera.
It is a protocol for high-speed serial communication between devices. In the market in recent years, many compatible products corresponding to the IEEE 1394 standard have appeared. Moreover, the corresponding speed has been increased. For example, most of the early digital video cameras were compatible with a communication speed of 100 Mbps only, but recently, 100 Mbps
Almost no products that are compatible with s are shipped, and most of the products are compatible with communication speeds of 200 Mbps and 400 Mbps. Furthermore, IEEE
When the E1394b standard is supported, the speed is further increased to 80
It is expected that products compatible with 0 Mbps will also appear in the market.

As described above, when the corresponding communication speed is different between products, the IEEE 1394 system has a problem that the transfer speed must be different for each product. Thus, in the IEEE1394 system,
Since it is necessary to transfer data at different speeds between connected products, the "speed map" was standardized as a means of knowing the speed between devices (nodes) in IEEE1394, but it is excluded in the IEEE1394-2000 standard. Was done. Instead, it can be solved by reading the "speed" field that exists in each device.
However, the bus configuration changes each time a "bus reset" occurs due to the removal and insertion of the IEEE 1394 cable, and the "speed" field must be read each time.

Even at "bus reset", I
Very large numbers of packets are sent and received within the EEE 1394 system and the bandwidth is very crowded. At this time, if packets are transmitted and received in order to know the corresponding speed, the bandwidth becomes more and more crowded. As the number of devices (nodes) increases, bandwidth congestion becomes more severe. Also, if the device does not have a "speed map", it does not know the communication speed. Therefore, if the "Acknowledge" signal notifying that the data has been received is first sent at the maximum speed, the transmission speed will be reduced and the transmission will be corrected. However, there is a possibility that the processing will not be completed within the expected time in some cases.

[0005]

As described above, according to the conventional method of acquiring communication speed information, packet transmission / reception is delayed by connecting / disconnecting the IEEE 1394 cable when the number of connection of devices is increased / decreased. There was a problem of being late. The present invention solves this problem relatively easily and creates a speed map in a short time, thereby eliminating wasteful communication and efficiently using a band. It is possible to create communication speed information between electronic devices. It is an object to realize a method, an acquisition method, and a recording medium that records a program that realizes these methods.

[0006]

In order to achieve the above object, the present invention is a system in which a plurality of electronic devices constituting a node on the system are connected by a bus and the electronic devices communicate with each other. In the communication speed information creating method, the first step of obtaining maximum communication speed information for each of the electronic devices from the self-identifier information sent by the electronic device at the time of bus reset and writing the maximum communication speed map, and the electronic device The maximum communication speed of the parent node, which is a directly connected higher-level electronic device, and the maximum communication speed of the self node are compared, and the slower one is selected, and the maximum communication is set as the maximum mutual communication speed information between the parent node and the self node. The second process described in the speed map is compared with the maximum mutual communication speed information between the node higher than the own node and the parent node and the maximum communication speed of the own node, and the slower one is selected. And a third step described in the maximum communication speed map as maximum mutual communication speed information between the upper node and the own node, and repeating these steps, the maximum communication of all electronic devices on the system. The maximum communication speed map in which the speed information and the maximum mutual communication speed information between all the electronic devices on the system are written is created as a communication speed information list.
As a result, it is possible to realize a communication speed information creation method capable of efficiently creating the maximum communication speed map in a short time.

Further, in a communication speed information acquisition method in a system in which a plurality of electronic devices are connected by a bus and communication is performed between the electronic devices, the self-identifier information transmitted from the electronic device at the time of bus reset A first process of obtaining maximum communication speed information for each electronic device and writing it in a maximum communication speed map, a maximum communication speed of a parent node that is a higher-level electronic device to which the electronic device is directly connected, and a maximum of its own node The second step of comparing the communication speeds and selecting the slower one and describing it in the maximum communication speed map as the maximum mutual communication speed information between the parent node and the own node, and between the node higher than the own node and the parent node The maximum mutual communication speed information is compared with the maximum mutual communication speed information of the own node, and the slower one is selected, and the maximum mutual communication speed information as the maximum mutual communication speed information between the upper node and the own node is selected. By repeating the third process described in the map and these processes, the maximum communication speed information of all the electronic devices on the system and the maximum mutual communication speed information of all the electronic devices on the system are obtained. The fourth step of creating the described maximum communication speed map, and determining the communication speed based on the maximum communication speed map. As a result, the maximum communication speed map can be efficiently created in a short time, the communication speed information can be acquired in a short time by using the obtained maximum communication speed map, and the communication congestion at the time of bus reset is eased. It is possible to realize a communication speed information acquisition method capable of performing the communication speed information acquisition.

Furthermore, in a recording medium in which a program for creating communication speed information is recorded in a system in which a plurality of electronic devices forming nodes on the system are connected by a bus and the electronic devices communicate with each other, A first step of obtaining maximum communication speed information for each electronic device from self-identifier information sent by the electronic device at the time of bus reset and writing the maximum communication speed information in a maximum communication speed map, and a higher-order electronic device to which the electronic device is directly connected The maximum communication speed of the parent node and the maximum communication speed of the self node are compared, and the slower one is selected, and the maximum mutual communication speed information between the parent node and the self node is described in the maximum communication speed map. The process, comparing the maximum mutual communication speed information between the parent node and the node higher than the own node and the maximum communication speed of the own node, select the slower one And a third step described in the maximum communication speed map as maximum mutual communication speed information between the node and the own node, and repeating these steps, the maximum communication speed information of all electronic devices on the system. And a program for creating the maximum communication speed map that describes the maximum mutual communication speed information between all electronic devices on the system. As a result, it is possible to realize a recording medium recording a program capable of efficiently creating the maximum communication speed map in a short time.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method of creating communication speed information according to the present invention will be described in detail with reference to the accompanying drawings.

The communication speed information creating method of the present invention aims to efficiently create a "speed map". FIG. 1 shows a configuration example of a bus network of IEEE 1394 equipment used for explaining the present invention. In FIG. 1, reference numerals 101 to 107 denote devices forming an IEEE 1394 node, reference numerals 111 to 125 denote IEEE 1394 ports, and reference numerals 130 to 136 denote IEEE 1394 cables. Each node 101-107 has its own IE
IEEE over the IEEE 1394 ports 111-125
They are connected by 1394 cables 130 to 136. Each of the nodes 101 to 107 has a physical (PHY) layer and a link (LINK) layer, and the corresponding speed is determined for each layer. Each node 101 to 1 in FIG.
The number written on the bottom of the box of 07 shows the corresponding speed, S100 is 100 Mbps, S200 is 200 Mbps.
ps and S400 indicate that 400 Mbps is the maximum corresponding speed of each layer.

IEEE 1394 ports 111-125
Is a parent port (Parent Port) on the signal input side and a child port (Chil) on the signal output side depending on the bus configuration.
d Port), non-connected port (Non Connected)
There are three possible types. In FIG. 1, ports 113, 11
6, 118, 119, 122, 125 are parent ports, and ports 111, 112, 114, 115, 120,
121 corresponds to the child port. Then the remaining port 1
The ports 17, 123, and 124 are not connected. Hereinafter, description will be made along this configuration.

FIG. 2 is a flow chart of the process for creating the "speed map". First, when starting at step 200, initialization processing is started at step 201, and a memory area for storing speed information and parent node information as shown in FIG. 3 is secured. Then, in step 202, each IEEE1394
The process shifts to a subroutine of a process (getSpdMapInfo) for collecting the maximum compatible speed (PHY speed) information of the physical layer of the node and the parent node information.

FIG. 4 shows a flowchart of this getSpdMapInfo process. In this flowchart, step 4
When the routine is entered at 00, the "PH" of the node called this time (first, "node 6" which is the root) is called at step 401.
The “Y speed” is obtained from the physical ID field (phy id) of the self ID packet (Self-Id) transmitted by the physical layer of each node when the “bus reset” occurs. Then, the obtained “PHY speed” ( 400 Mbps) is shown in FIG.
5 is shown in the memory area of pd [6] ". FIG. 5 shows the result recorded in this way. The column 501 in FIG. 5 corresponds to the recording result in this case. In the notation of FIG.
The speed "100 Mbps is represented by (0), 200 Mbps is represented by (1), and 400 Mbps is represented by (2) ().
The numbers in are actually recorded. Here 400 Mbp
(2) corresponding to s is recorded.

Next, in step 402 of FIG. 4, the process branches from the physical ID field of the self ID packet according to the number of child ports. In this example, since "node 6" has a child port, "node 5" which is one of the child ports
In step 403, a recursive call is made to obtain the data of. Then step 4 similar to the previous one
In the processing of 01, (1) corresponding to 200 Mbps is stored in the memory area of "spd [5]" of FIG. 3 as in the column of 502 of FIG. After that, since the child port also exists in "node 5", the branching process corresponding to step 402 in FIG. 4 is performed again, "node 4" which is one of the child ports is called, and step 403 is executed. A considerable recursive call is made.

In this way, after (2) corresponding to 400 Mbps is stored in the memory area of "spd [4]" of FIG. 3 corresponding to the column 503 of FIG. 5, a child port is provided in "node 4". Since it does not exist, in step 405 of FIG. 4, the node returns its own node number (node 4) as the return value and returns to step 404 of “node 5”, and the parent of the current node (node 4), which is the return value, is returned. The port (node 5) is acquired as the current port, and “parent_no” in FIG. 3 is acquired.
In the memory area of de [4] ", describe (5) as in the column of 504 in Fig. 5. By sequentially repeating such processing, 505 and subsequent figures in Fig. 5 are sequentially filled in and performed. 5
The storage of all data of is completed.

After that, when the restart function of the getSpdMapInfo process of FIG. 4 is completed, the process returns to FIG. 2 and the creation of the "speed map" is started from the "node 6" which is the "root node". FIG. 6 is a format diagram of the “speed map” in the IEEE 1394 standard, and FIG. 7 is a simplified view of the “speed map” created this time. In the format diagram of Fig. 6, the data length, CRC (Cyclic Rerundancy)
Check) code, the version number of this map since the last power reset, etc., and the maximum value (speed code) of the communication speed that can be sent between the nodes is sequentially described in the order of speed code numbers.

In step 203 of FIG. 2, since it is the "node 6" and the search of all the nodes is not completed yet, first, in step 204, the own "PHY speed" is written in the "speed map". . In FIG. 7, it corresponds to 701. Since there is no parent node in “node 6”, FIG.
Steps 205 and 206 of step 203 are completed, and step 203
Then, the same search is performed for "node 5". First, in step 204, the “PHY speed” of “node 5” is written in the “speed map”. In FIG. 7, it corresponds to 702. Next, in step 205 of FIG. 2, the “PHY speed” of the parent node “node 6” and the “PH speed” of the self “node 5”.
"Y speed" is compared. Then, the slower one (1) is set as the communicable speed of "node 5" and "node 6". In Fig. 7, 703A and 703B have this (1).
The value of is filled in.

Similarly, for the "node 4", the steps 204 and 205 of FIG. 2 are performed, and the "PHY speed" of the "node 4" is set to 704 of FIG. 7 and the "node 4".
705A and 705 to enable communication between "node 5" and
Write to B. Further, in step 206 of FIG. 2, the communicable speed (703A or 703B in FIG. 7) between the parent node (node 5) of itself and the node “node 6” which is larger than itself and the “PHY” of “node 4”. "Node 4" and "node 6", which is the slower than "speed"
The communication-enabled speed is set to and the data is written in 706A and 706B in FIG. Thereafter, by performing the same processing from "node 3" to "node 0", the "speed map" of FIG. 7 can be sequentially filled from 707 to 728A and 728B.

By the way, each of the nodes 101 to 107 has a physical (PHY) layer for controlling physical layers such as encoding and decoding of buses and data, and a link (LINK) layer having functions for generating and detecting error correction codes and packets. And the corresponding speed is determined for each layer. In this case, there is no problem if the maximum communication speed of the link layer is faster than or equal to the maximum communication speed of the physical layer, but if the maximum communication speed of the link layer is slower than the maximum communication speed of the physical layer, then within the node There is a risk of losing received packets. In order to prevent this, in a node whose maximum communication speed of the link layer is slower than the maximum communication speed of the physical layer, the maximum communication speed of the node is delayed according to that of the link layer. However, there is no problem with communication relaying this node because the link layer is not involved. In the configuration example of the bus network of FIG. 1, the “node 6” corresponds to a node whose maximum communication speed of the link layer is slower than the maximum communication speed of the physical layer. Therefore, in the “speed map” of FIG. 7, 701 and 712A and 712B are replaced with 801 and 812A and 812 of FIG.
Modify as in 2B to make the final "speed map".

The method of creating the communication speed information of the present invention has been described above. The acquisition of the communication speed information for determining the communication speed by referring to the "speed map" which is the communication speed information list thus created The present invention also covers methods and recording media storing programs for implementing these methods.

According to the present invention as described above, by creating the "speed map" in a short time, it is possible to devote time to other "bus reset" processing. IEEE1
Excludes the "speed map" from the 394-2000 standard,
It can be dealt with by reading the speed field of each IEEE 1394 device, but during the "bus reset" period, many packets are transmitted and received on the IEEE 1394 bus, and the bandwidth is very crowded. .
In such a situation, by creating a "speed map" instead of transmitting a packet to know the corresponding speed, it becomes possible to reduce bandwidth congestion at the "bus reset". Further, it is possible to reduce the load on the band in the normal time. This reduces wasteful communication and enables efficient use of bandwidth, and in the future IEEE
The effect of the present invention becomes even more pronounced when the number of products supporting 1394 increases and many devices are connected to the IEEE 1394 bus. Further, even when a next-generation bus having a configuration such as the IEEE 1394 bus appears, the present invention can improve the band efficiency.

[0022]

As described above, the invention of claim 1 of the present invention is a system in which a plurality of electronic devices constituting a node on the system are connected by a bus and the electronic devices communicate with each other. In the communication speed information creation method of 1), the electronic device is directly connected to the first step of obtaining maximum communication speed information for each electronic device from the self-identifier information sent by the electronic device at the time of bus reset and writing the maximum communication speed information in the maximum communication speed map. The maximum communication speed of the parent node, which is the higher-level electronic device, is compared with the maximum communication speed of the self node, and the slower one is selected and described in the maximum communication speed map as the maximum mutual communication speed information between the parent node and the self node. In the second process, the maximum mutual communication speed information between the node higher than the own node and the parent node, and the maximum communication speed of the own node are compared, and the slower one is selected and the higher node and the own node The third process of describing in the maximum communication speed map as large mutual communication speed information, and repeating these processes, the maximum communication speed information of all electronic devices in the system and all electronic devices in the system. A maximum communication speed map describing maximum mutual communication speed information between each other is created. As a result, the maximum communication speed map can be efficiently created in a short time and provided to the system.

According to a second aspect of the present invention, when the electronic device has a first means for processing a physical layer and a second means for processing a hierarchy higher than the physical layer, each electronic device is The maximum communication speed map is once created by using the maximum communication speed information of 1 as the maximum communication speed of the first means, and the maximum communication speed of the second means is slower than the maximum communication speed of the first means. The maximum communication speed information of the node of this electronic device and the maximum mutual communication speed information between this node and other nodes may be corrected with the maximum communication speed of the second means as an upper limit. Characterize. As a result, even if the maximum communication speed of the link layer is slower than that of the physical layer and has the physical layer and the link layer, it is possible to create the maximum communication speed map that enables correct communication without packet loss. .

According to a third aspect of the present invention, the bus is IEEE
It is characterized by being an E1394 serial bus. This allows the invention to be deployed on an IEEE 1394 system.

The invention of claim 4 of the present invention is characterized in that the communication speed is determined based on the maximum communication speed map realized in claim 1. As a result, the maximum communication speed map can be efficiently created in a short time, the communication speed information can be acquired in a short time by using the obtained maximum communication speed map, and the communication congestion at the time of bus reset can be eased. it can.

The invention of claim 5 of the present invention is characterized in that a recording medium recording a program for creating the maximum communication speed map of claim 1 is created. As a result, it is possible to realize a recording medium recording a program for efficiently creating the maximum communication speed map in a short time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a bus network of an IEEE 1394 device.

FIG. 2 is a flowchart of a process for creating a velocity map according to the present invention.

FIG. 3 is a diagram showing a memory area in which speed information and parent node information are stored.

FIG. 4 is a processing flowchart for collecting the maximum corresponding speed information and parent node information of the physical layer of the present invention.

5 is a diagram showing a recording result in the memory area of FIG.

FIG. 6 is a format diagram of a speed map in the IEEE1394 standard.

FIG. 7 is a diagram of a velocity map created this time along the example of FIG. 1.

FIG. 8 is a diagram of a final velocity map obtained by modifying FIG. 7;

[Explanation of symbols]

101-107 ... IEEE 1394 node, 111-1
25 ... IEEE 1394 port, 130 to 136 ... IE
EE1394 cable.

Claims (5)

[Claims] 1. A method for creating communication speed information in a system in which a plurality of electronic devices constituting a node on a system are connected by a bus and the electronic devices communicate with each other, wherein the electronic devices are A first step of obtaining maximum communication speed information for each of the electronic devices from the transmitted self-identifier information and writing the maximum communication speed map, and maximum communication of a parent node that is a higher-level electronic device to which the electronic device is directly connected A second step of comparing the speed and the maximum communication speed of the own node and selecting the slower one, and writing it in the maximum communication speed map as the maximum mutual communication speed information between the parent node and the own node; Maximum communication speed information between the node and the parent node and the maximum communication speed of the own node are compared, and the slower one is selected, and the maximum mutual communication speed between the upper node and the own node is selected. A third process described in the maximum communication speed map as information, and by repeating these processes, the maximum communication speed information of all the electronic devices on the system and the mutual communication between all the electronic devices on the system. The maximum communication speed map that describes the maximum mutual communication speed information is created and used as a communication speed information list. 2. When the electronic device has first means for processing a physical layer and second means for processing a layer higher than the physical layer, the maximum communication speed information for each electronic device is set. The maximum communication speed map is created once as the maximum communication speed of the first means, and for the electronic device in which the maximum communication speed of the second means is slower than the maximum communication speed of the first means, The maximum communication speed information of the node of the electronic device and the maximum mutual communication speed information between this node and another node may be corrected with the maximum communication speed of the second means as an upper limit. The communication speed information creating method between electronic devices according to claim 1. 3. The method for creating communication speed information between electronic devices according to claim 1, wherein the bus is an IEEE 1394 serial bus. 4. A communication speed information acquisition method in a system in which a plurality of electronic devices are connected by a bus and communication is performed between the electronic devices, wherein the self-identifier information transmitted from the electronic device at the time of bus reset The first process of obtaining maximum communication speed information for each electronic device and writing it in the maximum communication speed map, the maximum communication speed of the parent node that is the higher-level electronic device to which the electronic device is directly connected, and the maximum of the own node A second step of comparing the communication speeds and selecting the slower one and describing it in the maximum communication speed map as the maximum mutual communication speed information between the parent node and the own node, and between a node higher than the own node and the parent node The maximum mutual communication speed information is compared with the maximum mutual communication speed information of the own node, and the slower one is selected to obtain the maximum mutual communication speed information as the maximum mutual communication speed information between the upper node and the own node. And the maximum communication speed information of all electronic devices on the system and the maximum mutual communication speed information between all electronic devices on the system. And a fourth step of creating the maximum communication speed map described above, wherein the communication speed is determined based on the maximum communication speed map. 5. A recording medium in which a program for creating communication speed information is recorded in a system in which a plurality of electronic devices forming a node on the system are connected by a bus and the electronic devices communicate with each other. A first step of obtaining maximum communication speed information for each of the electronic devices from self-identifier information sent by the electronic device at the time of resetting and writing the maximum communication speed map, and a higher-order electronic device to which the electronic device is directly connected A second process in which the maximum communication speed of a certain parent node is compared with the maximum communication speed of the own node, and the slower one is selected and described in the maximum communication speed map as maximum mutual communication speed information between the parent node and the own node. The maximum mutual communication speed information between the parent node and the node higher than the own node and the maximum communication speed of the own node are compared, and the slower one is selected and the upper node and the own node are selected. A third process described in the maximum communication speed map as maximum mutual communication speed information between nodes, and repeating these processes, the maximum communication speed information of all electronic devices in the system and the maximum communication speed information in the system. A recording medium having recorded therein a program for creating the maximum communication speed map in which the maximum mutual communication speed information between all the electronic devices is recorded.