JP2005086642A - Communication apparatus and transfer rate switching method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically switch the setting of a data transfer rate to an appropriate one according to the operating state of an apparatus and the state of communication environment, and to perform processing by always transmitting/receiving data without delay. <P>SOLUTION: At the time of establishment of connection between apparatuses, when it is discriminated that connection with a destination apparatus (broadband router) 23 is not established based on an input waveform of a signal transmitted from a destination by connection decision and a setting switching block detchg, connection between the apparatuses is established by sequentially switching the data transfer rate from a high data transfer rate to a low data transfer rate and when the connection between the apparatuses is established, subsequent communication is performed by using the data transfer rate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a communication apparatus that performs communication by being connected to a network such as a WAN or a LAN, and a transfer rate switching method used in the communication apparatus.

  2. Description of the Related Art So-called network devices are being provided that allow various contents such as audio data such as music, still image data, and moving image data to be downloaded from a content server on the Internet and used. As network devices, in addition to personal computers, so-called AV devices used at home, such as television receivers and hard disk recorders having a communication function, have been provided.

  The network device as described above is connected to a target network via a so-called network connection device such as a router or a hub. Network devices and devices such as routers and hubs can be connected based on LAN standards such as Ethernet (registered trademark).

  In recent years, in a LAN standard such as Ethernet (registered trademark), for example, a data transfer rate (transmission path speed) such as 10BASE-T is 10 Mbps, and a data transfer rate such as 100BASE-TX is 100 Mbps. Are also being offered. That is, a standard with a higher data transfer rate has been provided.

  Before the advent of the standard with a data transfer rate of 100 Mbps, the data transfer rate used in the network device should have been fixed at 10 Mbps. However, the router or hub to which the network device is connected has a data transfer rate of 100 Mbps. If the device itself is also capable of handling a data transfer rate of 100 Mbps, it would be desirable to be able to process data at a higher speed of 100 Mbps instead of 10 Mbps.

  In such a case, it is conceivable that the user (user) of the network device manually switches the data transfer speed setting of the network device. However, for users who are unfamiliar with network devices, switching the data transfer rate setting is troublesome, and it may be inconvenient because it takes time to change the setting and makes it inconvenient.

  Therefore, in Patent Document 1 described later, attention is paid to the fact that the Manchester coding system is used in the 10BASE-T standard, and other coding systems are used in 100BASE-TX instead of the Manchester coding system. When the data transfer rate is set to 10 Mbps, the violation of Manchester code is detected and accumulated, and when this exceeds a certain value, it is determined that the data transfer rate is not 10 Mbps but 100 Mbps. Thus, a technique for automatically changing the data transfer rate setting from 10 Mbps to 100 Mbps is disclosed.

  With the technology described in Patent Document 1, when the data transfer rate of a network device that has been often used at a data transfer rate of 10 Mbps can be changed to 100 Mbps, the user's hand is automatically detected. The data transfer speed can be automatically switched from 10 Mbps to 100 Mbps without bothering.

In addition, said patent document 1 is as follows.
JP 2002-44182 A

  By the way, the technique disclosed in the above-mentioned Patent Document 1 basically changes the setting of the data transfer rate only once according to the actual data transfer rate used between connected devices. This makes it possible to satisfactorily perform subsequent communication using a high data transfer rate without bothering hands.

  In other words, the technology disclosed in Patent Document 1 can be used as a basic function for a conventionally available 10 Mbps data transfer rate, but for a newly available 100 Mbps data transfer rate. In other words, it is intended to be compatible as an extended function so that the data transfer speed setting can be automatically changed from a low speed to a high speed.

  However, considering the actual use of network devices, changing the data transfer rate setting is not possible even before the connection between devices is established (when establishing a connection between devices). Even after it is established and communication is actually possible, there is a need to do this. In addition to changing from a low data transfer rate to a high data transfer rate, it may be necessary to change the setting from a high data transfer rate to a low data transfer rate.

  First, consider the data transfer rate when establishing a connection between devices. For example, when connecting devices that can handle data transfer speeds of 10 Mbps and 100 Mbps, the necessary data is sent and received between the connected devices at the start of communication to check the communication conditions. Many devices that perform auto-negotiation (negotiation at the start of communication) to make communication conditions such as a data transfer rate appropriate are also provided.

  However, due to the quality of the router, hub, or connection cable, or because of external noise or signal attenuation, the signal waveform from the router or hub becomes a violation of the standard. It can be considered that the auto-negotiation itself may be impossible. If the data transfer speed is fast, the clock becomes faster, so it is more susceptible to noise and attenuation. In order to avoid such a situation, at present, the user should try to connect by adjusting the data transfer speed through trial and error of the setting of the network device, or the router, hub or connection cable. Can only be changed to high accuracy and reliability.

  However, it is not practical to require the user to change the setting of the data transfer rate by manual operation or to determine the optimum setting value of the data transfer rate. In other words, general users who use so-called information appliances (generally referred to as network devices here) such as hard disk recorders with communication functions have network knowledge and adjust the data transfer speed to an appropriate one. I can't expect to do it. In addition, changing the router, hub, or connection cable to a high-precision one places an economical load on the user.

  Next, consider the data transfer rate after the connection between the devices is established. For example, even when 100 Mbps is set as the data transfer rate by auto-negotiation at the start of communication, if communication errors due to external noise or signal attenuation occur frequently, communication retries increase and data reception is completed. It takes a long time to complete normal communication.

  In this case, it is conceivable that the user manually changes the data transfer speed setting of the network device to 10 Mbps, and switches the data transfer speed to 10 Mbps by turning on the power again and connecting / disconnecting the cable. However, if the error frequency is to some extent, it is considered that the total time until the completion of data reception may be shorter if the previous 100 Mbps connection is used even if a loss time due to retry is included. In other words, if the user does not accurately recognize the occurrence of the communication error, it is impossible to properly determine whether or not it is necessary to change the data transfer rate setting. For example, I would like to avoid user manual operations as much as possible.

  Even when 10 Mbps is set as the data transfer rate, it may be considered that communication can be performed at high speed and satisfactorily by actually using 100 Mbps as the data transfer rate. For example, at the start of communication, the car that generated noise stopped nearby, so communication could not be performed satisfactorily at 100 Mbps, but the car that generated noise ran away, This is the case where the communication environment is improved and communication can be sufficiently performed even at a data transfer rate of 100 Mbps.

  For this reason, when establishing a connection between devices, or after establishing a connection between devices and becoming ready for communication, the user is made aware of it depending on the state of each and the communication environment. Therefore, it is desired to be able to always send and receive data without delay by enabling the data transfer rate setting to be changed to an appropriate one.

  In view of the above, a device that automatically switches the data transfer rate setting to an appropriate one according to the operating state of the device and the communication environment, and always sends and receives data without delay, It aims to provide a method.

In order to solve the above problem, a communication device according to claim 1 is provided.
One of a plurality of data transfer rates can be selected and used, and at the start of communication, communication conditions are confirmed by negotiating with the counterpart device, and between devices. A communication device having an automatic connection mode for establishing a connection,
Automatic connection means for establishing a connection between devices in the automatic connection mode;
Based on a signal supplied from the counterpart device, a determination means for determining whether or not a connection has been established with the counterpart device;
When it is determined that the connection cannot be established by the determining means, the automatic connection mode is turned off and the data transfer speed is switched from a high data transfer speed to a low data transfer speed in order to establish a connection between devices. Transfer speed switching means to
Each time the data transfer rate is switched by the transfer rate switching means, it is determined whether or not a connection between devices has been established, and communication is performed using the data transfer rate when it is determined that a connection between devices has been established. And a transfer rate control means for controlling the communication device.

  According to the communication device of the first aspect of the invention, at the start of communication, the automatic connection means negotiates with the counterpart device by communication, confirms the communication conditions, and communicates between the devices. A connection between devices is established by using an automatic connection mode for establishing a connection by so-called auto-negotiation for establishing a connection.

  In this case, when it is determined that the connection with the partner device cannot be established based on the signal transmitted from the partner, the determination unit uses the transfer rate switching unit instead of the automatic connection mode. By switching from high data transfer rate to low data transfer rate sequentially, connection between devices is established, and by using the data transfer rate at which connection between devices can be established by the transfer rate control means, Subsequent communication is performed.

  As a result, when the connection between devices cannot be established, the data transfer speed can be set so that the connection between devices can be established by switching the data transfer speed from a high speed to a low speed. Is done. Also, by always changing the data transfer rate from high to low, there is no point in selecting a low data transfer rate without meaning, and the data transfer rate available at that time is not selected. The fastest one can be selected and used.

The communication device of the invention according to claim 2
A setting connection mode that allows one of a plurality of data transfer rates to be selected and used, and establishes connection between devices at a predetermined data transfer rate at the start of communication. A communication device having
A setting connection means for establishing a connection between devices using a data transfer speed that is not a maximum speed as the predetermined data transfer speed according to the setting connection mode;
Based on a signal supplied from the counterpart device, a determination means for determining whether or not a connection has been established with the counterpart device;
If the determination means determines that the connection between the devices has been established, the data transfer rate is sequentially switched from a higher data transfer rate to a lower data transfer rate to establish a connection between the devices. Transfer speed switching means;
Each time the data transfer rate is switched by the transfer rate switching means, it is determined whether or not a connection between devices has been established, and communication is performed using the data transfer rate when it is determined that a connection between devices has been established. And a transfer rate control means for controlling as described above.

  According to the communication apparatus of the second aspect of the present invention, the setting connection mode in which the connection between devices is established by the setting connection means at the start of communication using a predetermined data transfer rate. Is used to establish a connection between devices.

  In this case, when it is determined that the connection with the counterpart device can be established based on the signal transmitted from the counterpart, the transfer speed switching means switches from the high data transfer rate to the low speed. By sequentially switching to the data transfer rate, the connection between the devices is established, and the subsequent communication is performed by the transfer rate control means using the data transfer rate at which the connection between the devices has been established. .

  This ensures that the connection between devices is established at the fastest data transfer rate according to the current communication environment while ensuring that communication using a preset data transfer rate can be performed at the start of communication. To be able to communicate. Even in this case, the data transfer speed is always changed from a high speed to a low speed so that a low-speed data transfer speed can be selected without any meaning. The fastest data transfer speed can be selected and used.

Further, the communication device of the invention according to claim 3 is
A setting connection mode in which one of a plurality of data transfer rates can be selected and used, and a connection between devices is established at a predetermined data transfer rate at the start of communication; A communication device having an automatic connection mode in which a communication condition is confirmed by negotiating with a counterpart device and a connection between the devices is established,
A setting connection means for establishing a connection between devices using a data transfer speed that is not a maximum speed as the predetermined data transfer speed according to the setting connection mode;
First, when the connection between the devices is established by the setting connection means, based on a signal supplied from the counterpart device, it is determined whether or not the connection with the counterpart device is established. Discriminating means, and
When it is determined that the connection between devices can be established by the first determining means, automatic connection means for establishing a connection between devices in the automatic connection mode;
Secondly, after establishing the connection between the devices by the automatic connection means, it is determined whether or not the connection with the counterpart device can be established based on a signal supplied from the counterpart device. Discrimination means;
If it is determined by the second determining means that the connection between the devices cannot be established, the automatic connection mode is turned off, and the data transfer rate is sequentially changed from a higher data transfer rate to a lower data transfer rate. Transfer speed switching means for establishing a connection between devices by switching,
Each time the data transfer rate is switched by the transfer rate switching means, it is determined whether or not a connection between devices has been established, and communication is performed using the data transfer rate when it is determined that a connection between devices has been established. And a transfer rate control means for controlling as described above.

  According to the communication device of the third aspect of the present invention, the setting connection mode for establishing a connection between devices using a predetermined data transfer rate at the start of communication, and the start of communication At times, the connection is established by so-called auto-negotiation, in which the automatic connection means negotiates with the counterpart device by communication, confirms the communication conditions, and establishes the connection between the devices. The automatic connection mode can be used. First, the connection between the devices is established by the setting connection means.

  In this case, when it is determined by the first determination means that the connection with the counterpart device has been established based on the signal transmitted from the counterpart, the connection between the devices is established by the automatic connection means. If the second determination means determines that the connection between the devices cannot be established, the transfer speed switching means replaces the high-speed data transfer rate with the low-speed data transfer instead of the automatic connection mode. By sequentially switching to the rate, the connection between the devices is established, and the subsequent communication is performed by the transfer rate control means using the data transfer rate at which the connection between the devices has been established.

  As a result, at the start of communication, while ensuring that communication using a preset data transfer rate can be performed, an addition is given to the device by automatic connection means using the automatic connection mode that is a function of the device. The connection between devices can be established quickly and using a faster data transfer speed. If the connection cannot be established, the connection between devices is established at the fastest data transfer speed according to the current communication environment. To be able to communicate.

  Even in this case, the data transfer speed is always changed from a high speed to a low speed so that a low-speed data transfer speed can be selected without any meaning. The fastest data transfer speed can be selected and used.

The communication device of the invention according to claim 4
A communication device adapted to select and use one of a plurality of data transfer rates,
A detecting means for detecting a communication error frequency when communication is performed using a data transfer speed other than at least the minimum data transfer speed;
When the error frequency detected by the detection means is equal to or higher than a predetermined value, the low-speed direction change is performed so that the communication is continued by changing to a data transfer speed lower than the current data transfer speed. And means.

  According to the communication device of the fourth aspect of the present invention, when the error frequency detected by the detecting means is equal to or higher than a predetermined value, it is determined that normal communication cannot be performed and the low speed direction change is performed. By means, the communication is continued by changing to a data transfer rate lower than that at present.

  As a result, after the connection between devices is established, even if the communication environment deteriorates and proper communication cannot be performed at the current data transfer speed, the data transfer speed lower than the current speed can be reduced. By using it and continuing the communication, the communication can be continued without being interrupted.

A communication device according to a fifth aspect of the present invention is the communication device according to the fourth aspect,
High-speed direction change means for controlling to continue communication by changing to a data transfer speed higher than the present at a predetermined timing after changing the data transfer speed to a low data transfer speed by the low-speed direction change means A communication apparatus comprising:

  According to the communication device of the fifth aspect of the present invention, when the data transfer speed is changed to a low speed by the low speed direction changing means, for example, a predetermined time has elapsed after the current data transfer speed is set. Later, after a certain period of time has elapsed since the start of data supply, or immediately before downloading a predetermined amount of data, the high-speed direction changing means at a predetermined timing uses a higher data transfer rate than the current data transfer rate. The communication is continued.

  As a result, even after the communication environment has deteriorated and the data transfer speed has been switched to a low speed, if the high data transfer speed can be used, the communication is continued by switching to a high data transfer speed. To be able to. In this case as well, when the error frequency exceeds a predetermined value, switching to a low data transfer speed can be performed by the detection means and the low speed direction changing means. It is possible to prepare an environment in which data can be sent and received and processed.

The communication device of the invention according to claim 6
A communication device adapted to select and use one of a plurality of data transfer rates,
If communication is performed using a data transfer rate other than at least the maximum data transfer rate, change to a data transfer rate that is faster than the current data transfer rate and continue communication at a determined timing. High-speed direction changing means to control,
A detecting means for detecting a communication error frequency when communication is performed using a data transfer speed other than at least the minimum data transfer speed;
When the error frequency detected by the detection means is equal to or higher than a predetermined value, the low-speed direction change is performed so that the communication is continued by changing to a data transfer speed lower than the current data transfer speed. And means.

  According to the communication device of the sixth aspect of the present invention, for example, after a predetermined time has elapsed since the current data transfer rate was set, after a predetermined time has elapsed since the start of data supply, or a predetermined amount of data is stored. At a predetermined timing such as immediately before downloading, the high-speed direction changing means changes the data transfer speed to be higher than the current data transfer speed. Then, when the error frequency is detected by the detecting means and becomes equal to or higher than a predetermined value, the low-speed direction changing means is changed to a data transfer speed lower than the current data transfer speed.

  As a result, when the communication environment is improved, communication is automatically performed using a high data transfer rate. When the communication environment deteriorates, the low data transfer rate is automatically set. Communication is performed using. As a result, it is possible to perform data transmission and reception and processing by properly performing communication without delay at all times.

  According to the present invention, it is possible to reduce inconveniences such as “cannot connect to the network” and “cannot connect to home router or hub” from network device users. In addition, it is possible to reduce a burden of a user or a manufacturer's service person looking for setting of the data transfer speed of the network device by operating while looking at the screen. In addition, by automating the change of the data transfer rate when establishing a connection between devices, it is possible to provide a good network environment without causing the user to notice any problems. In addition, the data transfer speed at the time of connection setting can be made as high as possible.

  In addition, even after the connection between devices is established, even if the communication environment deteriorates and good communication is not possible, the data transfer speed used is automatically optimized and data is always transmitted without delay. Sending and receiving can be processed without problems.

  Hereinafter, an embodiment of an apparatus and a method according to the present invention will be described with reference to the drawings. In the following description, an example in which an Ethernet (registered trademark) cable is connected to an AV device equipped with Linux (registered trademark) as an OS will be described.

  In addition, an AV device and a broadband router to which the AV device described below is connected can selectively use at least 10 Mbps and 100 Mbps as a data transfer rate.

  In addition, an AV device and a broadband router to which the AV device described below is connected communicate with each other when the connection is established with a device that is connected through an Ethernet (registered trademark) cable and performs communication. It is equipped with an auto-negotiation function that establishes a connection (link) between devices reliably by confirming various communication conditions and selecting an appropriate one by negotiating with each other. .

[1. Switching the data transfer rate when establishing a connection between devices]
[1-1. When the default setting is “Auto negotiation ON”
First, referring to FIG. 1, as an example of the default setting, an AV device that establishes a connection between devices by first performing auto-negotiation when the power is turned on or a LAN cable is connected. A description will now be given of setting switching of the data transfer rate performed when establishing a connection between devices.

  In FIG. 1, reference numeral 10 denotes an AV device to which the present invention is applied, and reference numeral 20 denotes an external network to which the AV device 10 is connected. The AV device 10 includes a connector jack 11 for Ethernet (registered trademark), an access controller 12, and a microcomputer 13 for system control as hardware related to the present invention. In this case, a LAN cable 22 for connecting the AV device 10 to the network 20 is connected to the connector jack 11 as will be described later.

  The access controller 12 is connected between the connector jack 11 and the microcomputer 13 and executes protocol processing necessary for Ethernet (registered trademark) connection under the control of a device driver described later. Further, the access controller 12 is controlled by a microcomputer 13 to be described later, detects a bit string sent from the network 20, and when the bit string can be obtained or cannot be obtained, this is replaced with hardware. It has functions such as notifying the microcomputer 13 by interruption, and converting various commands and data to be transmitted to the network 20 into a transmission format and transmitting them.

  In addition, as such an access controller 12, there is an IC “DP83815” of National Semiconductor Corporation (USA), and a signal related to a protocol and a signal related to a connection state and a hardware interrupt are assigned to separate external pins. ing.

  The microcomputer 13 includes a kernel kernel, a network device driver ntwrk, a connection determination and setting switching block detchg, and a DHCP client daemon dhcpclt as part of software executed by the microcomputer 13.

  In this case, the kernel kernel is, for example, Linux (registered trademark) Kernel 2.4. The network device driver ntwrk is for enabling data access to the network 20 by controlling the access controller 12. In addition, the network device driver ntwrk controls the access controller 12 at the time of turning on the power to check various communication conditions with the broadband router 23 to which the AV device 10 is connected. It is possible to perform auto-negotiation that automatically establishes various communication conditions such as transfer speed and establishes a connection (link) between devices.

  Furthermore, the connection determination and setting switching block detchg accepts a signal supplied from the broadband router 23 through the access controller 12, and whether or not the connection between the devices can be established based on the accepted signal (input waveform of the accepted signal). And a process for switching (changing) the data transfer rate setting when it is determined that the connection of the device cannot be established. The DHCP client daemon dhcpclt is for realizing the DHCP protocol.

  On the other hand, the network 20 is configured as follows in the example shown in FIG. That is, the connector plug 21 corresponding to the connector jack 11 is connected to the LAN cable 22, and the LAN cable 22 is further connected to the broadband router 23. Although not shown, the broadband router 23 has an Ethernet (registered trademark) port and an ADSL modem port. The broadband router 23 is connected to the ISP 25 via the telephone line 24 by the ADSL method, and further connected to the DHCP server 27 via the Internet 26.

  In such a configuration, when the AV equipment 10 is turned on while the connector plug 21 is connected to the connector jack 11, the microcomputer 13 is activated, and first the network device driver ntwrk is started. The access controller 12 is controlled to perform auto-negotiation with the broadband router 23.

  Then, the connection determination and setting switching block detchg determines whether or not the connection between the devices is established. If it is determined that the connection cannot be established, the access controller 12 is controlled through the network device driver ntwrk to perform auto-negotiation. Is set to OFF, and the data transfer speed is changed to a low speed to establish a connection between devices. If it is determined by the connection determination and setting switching block detchg that the connection between the devices, that is, the connection with the broadband router 23 has been established, the connection determination and setting switching block detchg displays this as a DHCP client daemon dhcpclt. To request an IP address.

  When the DHCP client daemon dhcpclt receives a request for acquiring an IP address, it requests the network device driver ntwrk to acquire an IP address through the kernel kernel. The network device driver ntwrk sets an IP address acquisition command to the access controller 12.

  The access controller 12 requests the DHCP server 27 to assign an IP address through the line of jack 11 → plug 21 → LAN cable 22 → broadband router 23 → phone line 24 → ISP 25 → Internet 26. The DHCP server 27 gives the IP address assigned to the AV device 10 to the access controller 12 in the reverse flow.

  The kernel kernel takes in the IP address given to the access controller 12 through the network device driver ntwrk. In this way, when the AV device 10 is powered on, the AV device 10 establishes a connection with the broadband router 23, receives an IP address assignment, and the AV device 10 can use the network 20.

  Although the description has been given here assuming that the DHCP server 27 provides an IP address in response to a request, the present invention is not limited to this. As shown in FIG. 1, when the broadband router 23 has the DHCP server function 231, the broadband router 23 uses its own DHCP server function 231 in response to a request from the AV device 10. It is also possible to assign an IP address to the AV device 10. Also, by enabling the router device to switch whether or not to use its own DHCP server function, the user selects whether the router assigns an IP address or an external device such as a DHCP server. It is also possible to do so.

  The connection determination and setting switching block detchg of the AV device 10 of this embodiment can establish a connection with the broadband router 23 based on the waveform of the signal supplied from the broadband router 23 received through the access controller 12. It is possible to determine whether or not.

  FIG. 2 and FIG. 3 are diagrams for explaining processing in the case of determining whether or not the connection between devices performed in the connection determination and setting switching block detchg has been established. 2 and 3, a waveform f1 is an input waveform of a signal supplied to the AV device 10, and a waveform f2 is a waveform obtained by inverting the phase of the waveform f1. A waveform f3 indicated by a dotted line is a differential waveform obtained by taking the difference between the waveform f1 and the waveform f2, and can express the fluctuation of the input waveform f1 more greatly.

  According to the Ethernet (registered trademark) standard, the rising waveform of the differential waveform f3 is within a predetermined range indicated by symbols TH1 and TH2 in FIGS. 2 and 3 within a certain period from the start of the rising. If it is not within the range, it is considered a violation and normal communication cannot be performed. In the case of the differential waveform f3 in FIG. 2, since there is no noise mixed in the input waveform, it falls within a predetermined range indicated by symbols TH1 and TH2 in a period of seven small scales from the start of the change. It can be confirmed that it is in place.

  However, as shown in FIG. 3, in the case where some noise is mixed in before the original signal rise, the differential waveform f3 rises at a timing faster than the original rise. To change. In this case, the rising waveform of the first wave of the differential waveform f3 is within the predetermined range indicated by the symbols TH1 and TH2 from the start of the change only in four small scales in FIG. .

  In this way, whether the connection between the devices can be established by checking whether the waveform of the rising portion of the input signal waveform is within a predetermined range (whether the input waveform is in violation of the standard). Can be determined. When establishing a connection between devices, it is unlikely that an initial communication error will occur. Therefore, it is quicker and more accurate than detecting a communication error and confirming whether or not a connection could be made according to its frequency. It is possible to determine whether or not a connection between devices can be established.

  In the connection determination and setting switching block detchg of this embodiment, the input signal is shown in FIG. 3 within a certain period from the time of turning on the power, or within a certain period from the start time of a predetermined program such as the start time of auto negotiation. If the waveform at the rising edge does not fall within the predetermined range as shown in, the auto-negotiation function is turned off, the data transfer rate is changed, and the process for establishing the connection between devices is executed. ing.

  FIG. 4 is a flowchart for explaining the connection switching of the AV device 10 shown in FIG. 1 and the data transfer rate setting switching process performed in the setting switching block detchg. As described above, the processing shown in FIG. 4 is performed within a certain period from the time of power-on, or within a certain period from the start of a predetermined program such as the start time of auto-negotiation. This is a process executed by the connection determination / setting switching block detchg when the waveform of the rising portion does not fall within a predetermined range as shown.

  In this case, the connection determination / setting switching block detchg executed by the microcomputer 13 controls the access controller 12 to turn off the auto-negotiation and is set in a register (not shown) of the access controller 12. An attempt is made to establish a connection between devices by fixing the data transfer rate at 100 Mbps (step S1).

  Then, as described with reference to FIGS. 2 and 3, the connection determination and setting switching block detchg confirms the waveform of the input signal and determines whether or not the connection has been established (step S2). If it is determined in step S2 that the connection has been established, the communication process is continued with the data transfer rate being 100 Mbps, that is, the data transfer rate setting in the register of the access controller 12 is kept at 100 Mbps, The process of FIG. 4 is terminated.

  On the other hand, if it is determined in step S2 that the connection could not be established, the microcomputer 13 controls the access controller 12 to turn off the auto-negotiation and store it in a register (not shown) of the access controller 12. An attempt is made to establish a connection between devices by fixing the set data transfer rate to 10 Mbps (step S3).

  As in step S2, the connection determination and setting switching block detchg confirms the waveform of the input signal as described with reference to FIGS. 2 and 3, and determines whether or not the connection has been established. (Step S4). If it is determined in step S3 that the connection has been established, the communication process is continued while the data transfer rate is 10 Mbps, that is, the data transfer rate setting of the register of the access controller 12 is kept at 10 Mbps, The process of FIG. 4 is terminated.

  If it is determined in step S3 that the connection cannot be established, in this example, the value of the register of the access controller 12 is set so that auto-negotiation, which is the default setting, is turned on. Is returned (step S5), and the processing shown in FIG.

  Thus, in the case of this example, in the AV device 10 in which the default setting is to establish a connection between devices by performing auto-negotiation, the connection between devices is performed even if auto-negotiation is performed. If it is not possible to establish a connection, turn off auto negotiation and fix the data transfer rate to 100 Mbps to establish a connection between devices. If this is not possible, turn off auto negotiation. The data transfer rate is fixed at 10 Mbps, and the connection between the devices is established.

  By doing so, an attempt is made to ensure a situation in which communication is performed at the highest possible data transfer rate (in this case, 100 Mbps), and a connection between devices cannot be established at a high data transfer rate. The data transfer rate is low (in this example, 10 Mbps) so that the connection between the devices can be established. In other words, the goal is to provide a communication environment that uses as fast a data transfer rate as possible, but if a connection cannot be established at a high data transfer rate, use a low data transfer rate to ensure reliable communication between devices. To establish a connection.

  In the case of this example, if the connection between devices cannot be established even at a data transfer rate of 10 Mbps, the auto-negotiation is performed over time to restore the connection between devices by returning to the default setting. It is easy to redo the process so that it is established.

[1-2. When the default setting is “Auto negotiation OFF (off), data transfer rate fixed at 10 Mbps”]
Next, referring to FIG. 5, as a default setting, when power is turned on or when a LAN cable is connected, auto-negotiation is set to OFF and the data transfer rate is set to 10 Mbps. The case of an AV device that establishes the above will be described. In other words, the AV device in this example can reliably establish the connection between the devices by setting the data transfer rate to 10 Mbps first, and when the establishment of the connection can be confirmed at 10 Mbps, the higher-speed data can be obtained. It tries to switch to the transfer rate.

  In FIG. 5, reference numeral 30 denotes the AV device, and reference numeral 20 denotes an external network to which the AV device 30 is connected. The basic configuration of the AV device 30 has the same configuration as that of the AV device 10 shown in FIG. 1. However, as shown below, the function of the network device driver ntwrk is different and the hot plug script hotplug, And it has a hook program hooker.

  That is, the AV device 10 includes a connector jack 11 for Ethernet (registered trademark), an access controller 12, and a microcomputer 13 for system control as hardware related to the present invention. In this case, a LAN cable 22 for connecting the AV device 10 to the network 20 is connected to the connector jack 11 as will be described later. The connector jack 11 and the access controller 12 are configured in the same manner as the AV device 10 shown in FIG. 1 and have the same functions.

  The microcomputer 13 includes a kernel kernel, a network device driver ntwrk, a hot plug script hotplug, and a DHCP client daemon dhcpclt as part of software executed by the microcomputer 13.

  In this case, the kernel kernel is, for example, Linux (registered trademark) Kernel 2.4, similarly to the AV device 10 shown in FIG. The network device driver ntwrk is for enabling data access to the network 20 by controlling the access controller 12. Furthermore, the network device driver ntwrk has a function of performing a process of switching (changing) the setting of the link detection block lnkdet and the data transfer rate for detecting whether the access controller 12 is signalally linked to the network 20. It also includes a setting switching / determination block chgdet that realizes a function of determining whether or not a connection between devices has been established.

  The function realized by the setting switching / determination block chgdet provided in the network device driver ntwrk is basically realized in the same manner as the connection determination and setting switching block detchg of the AV device 10 shown in FIG. Is. However, when the connection determination and setting switching block detchg of the AV device 10 shown in FIG. 1 detects that the connection between the devices cannot be established, the data transfer speed is switched to establish the connection between the devices. In contrast to this, the setting switching / determination block chgdet of the AV device 30 shown in FIG. 5 operates when a connection between devices can be established at a low data transfer rate, as will be described later. First, the data transfer speed is changed to a high speed so as to determine whether or not the connection between the devices has been established.

  The hot plug script hotplug is called based on the detection result of the link detection block lnkdet. At the time of calling, the hot plug script hotplug receives an environment variable having predetermined information from the network device driver ntwrk. Further, the hook program hooker is one of a plurality of hook programs, and is executed by a calling code described at the end of the hot plug script hotplug. The DHCP client daemon dhcpclt is for realizing the DHCP protocol.

  In FIG. 5, the network 20 is configured similarly to the network 20 described with reference to FIG. 1.

  In such a configuration, as described above, the AV device 30 according to this embodiment can establish connection between devices as reliably as possible by setting auto-negotiation OFF (off) and a data transfer rate of 10 Mbps as default settings. I am doing so.

  That is, in the AV device 30 of this example, when the connector plug 21 is inserted into the connector jack 11, a bit string is obtained at the receiving side contact of the connector jack 11, and this is detected by the access controller 12. When the access controller 12 detects the bit string, it issues a hardware interrupt to the microcomputer 13 and notifies the microcomputer 13 that the LAN cable 22 is connected.

  In the microcomputer 13, when an interruption is made by the access controller 12, the network device driver ntwrk controls the access controller 12 to connect the devices (link) to the broadband router 23 with the data transfer rate fixed at 10 Mbps. ) And the link detection block lnkdet is started up to detect whether or not the link with the network 20 is established. When the link is established, the setting switching / determination block chgdet is operated to The transfer rate is changed to a faster one.

  In this example, the setting switching / determination block chgdet first attempts to switch to a higher data transfer rate by executing auto-negotiation. This is because auto-negotiation is provided in the AV device 30 as a basic function, and therefore there is a high possibility that the load on the AV device is small and the time required to establish a connection between the devices is short.

  If the connection between devices cannot be established by auto-negotiation, the setting switching / determination block chgdet turns off auto-negotiation and fixes the data transfer rate to 100 Mbps so as to establish a connection between the devices. To. If the connection between devices cannot be established when the data transfer rate is set to 100 Mbps, the auto-negotiation is turned off, the data transfer rate is returned to 10 Mbps, the connection between devices is established, and communication can be performed. I am doing so.

  In other words, the setting switching / determination block chgdet function establishes a connection between devices, and the link detection block lnkdet function detects whether a link has been established and confirms that the link has been established. When you call the hotplug script hotplug. At this time, an environment variable having predetermined information is sent from the network device driver netwrk to the hot plug script hotplug.

  When the hot plug script hotplug is called by the link detection block lnkdet, the corresponding hook program hooker is called from a plurality of hook programs according to the information of the environment variable sent along with the call.

  When this is called by the hot plug script hotplug, the hook program hooker prepares the kernel kernel to use the network 20, and then requests the DHCP client daemon dhcpclt to obtain an IP address.

  When the DHCP client daemon dhcpclt receives a request from the hook program hooker, it requests the network device driver ntwrk to obtain an IP address through the kernel kernel. The network device driver ntwrk sets an IP address acquisition command to the access controller 12.

  The access controller 12 requests the DHCP server 27 to assign an IP address through the line of jack 11 → plug 21 → LAN cable 22 → broadband router 23 → phone line 24 → ISP 25 → Internet 26.

  The DHCP server 27 gives the IP address assigned to the AV device 10 to the access controller 12 in the reverse flow. The kernel kernel takes in the IP address given to the access controller 12 through the network device driver ntwrk. Thus, when the LAN cable 22 is connected to the AV device 10, an IP address is assigned to the AV device 10, and the AV device 10 can use the network 20.

  When the connection of the LAN cable 22 is terminated, the processing by the access controller 12, the link detection block lnkdet, the hot plug script hotplug, and the hook program hooker is executed in the same manner, and the kernel kernel is set to be disconnected. The use of the network 20 is not permitted.

  FIG. 6 is a flowchart for explaining data transfer rate setting switching processing performed in the setting switching / determination block chgdet of the AV apparatus 30 shown in FIG. The process shown in FIG. 6 is a process executed by the setting switching / determination block chgdet when a link detection interrupt occurs when establishing a connection between devices as described above.

  In this case, the setting switching / determination block chgdet executed by the microcomputer 13 controls the access controller 12 to switch to auto-negotiation ON (on) and attempt to establish a connection between the devices (step) S11).

  In this example, the setting switching / determination block chgdet uses the detection output from the link detection block lnkdet and the internal timer interrupt to determine whether or not the connection with the broadband router 23 has been established. (Step S12). Specifically, the connection between devices is established when a link detection interrupt occurs prior to the expiration of a predetermined time after starting the process of establishing the connection between devices by auto-negotiation. Judging that it was done.

  When it is determined in step S12 that the connection has been established, the high-speed data transfer speed is normally selected. Therefore, the communication process is continued, that is, the data transfer of the register of the access controller 12 is performed. The processing in FIG. 6 is terminated without changing the speed setting.

  On the other hand, if it is determined in step S2 that the connection cannot be established, the microcomputer 13 controls the access controller 12 to turn off the auto-negotiation before returning the data transfer rate to 10 Mbps. At the same time, the data transfer rate set in a register (not shown) of the access controller 12 is fixed to 100 Mbps, and an attempt is made to establish a connection between the devices (step S13).

  Then, as in step S12, the setting switching / determination block chgdet uses the detection output from the link detection block lnkdet and the internal timer interrupt to determine whether or not a connection has been established with the broadband router 23. (Step S14). If it is determined in step S14 that the connection has been established, the communication process is continued with the data transfer rate being 100 Mbps, that is, the data transfer rate setting in the register of the access controller 12 is kept at 100 Mbps, The process of FIG. 6 is terminated.

  If it is determined in step S14 that the connection could not be established, in this example, the auto-negotiation which is the default setting is OFF and the data transfer rate is fixed to 10 Mbps. (Step S15), the connection between the devices is established, and the processing shown in FIG. 6 ends.

  As described above, the AV device 30 shown in FIG. 5 establishes a connection between devices by setting the data transfer rate to 10 Mbps. When the connection is established, the data transfer rate is automatically increased to a higher one. After the change, the actual communication can be started.

  In the AV device 30 shown in FIG. 5, the data transfer rate change processing at the time of establishment of the connection between devices is a connection between other devices when 10 Mbps (10BASE-T) is used. It is assumed that it can be established. At present, most of the products are compatible with 10BASE-T, and it can be said that most of the products can establish a connection at a fixed 10 Mbps.

  Also, 10BASE-T is technically mature compared to 100BASE-TX, the quality of products in the market is stable, and since the clock is low speed, there is an electrical margin and noise resistance performance. It is advantageous. From the above, even if it is assumed that it is always connected to other devices at 10 Mbps, there is no inconvenience such as the inability to establish a connection between devices, and even in the worst case, the data transfer rate As a result, 10 Mbps can be used.

  In the case of the AV device 10 shown in FIG. 1, as described above, the setting switching process of the data transfer rate is started when it is found that auto-negotiation is not possible. In order to automatically detect when auto-negotiation is not possible, start the time measurement from the power-on of the device or the start of some software, and trigger a time-out without link detection. The processing shown in FIG. 4 can be started.

  In addition, the AV device 30 shown in FIG. 5 turns off auto-negotiation from the beginning, and defaults to the 10 Mbps fixed mode setting that seems to be connected at the lowest data transfer speed (link detection is possible). Therefore, the link detection hardware interrupt is used as the start trigger of the flow.

  In the AV device 10 shown in FIG. 1, as described above, even if a cable is inserted in the middle to join the network, the user can perform operations such as restarting the power supply of the AV device or starting some software. You cannot start the flow without getting it. However, in the case of the AV device shown in FIG. 15, the hardware link detection interrupt is used as a trigger for starting the data transfer rate switching process. The hardware link detection interrupt is activated not only when a cable is inserted but also when the power is turned on. The AV device 30 can establish a connection between the devices more reliably than the AV device 10 because it sometimes occurs.

  However, the AV device 10 shown in FIG. 1 is a mechanism effective in hardware that cannot realize the mechanism like the AV device 30 shown in FIG. For example, when it is desired to make the configuration as simple as possible from the viewpoint of cost, microcomputer performance, etc., the configuration shown in FIG. 1 is used. It is conceivable to adopt the configuration as shown.

  Here, 1-1. When the default setting is “auto negotiation ON”, 1-2. The case where the default setting is “auto-negotiation OFF (off) and data transfer rate fixed at 10 Mbps” has been described. However, even when the default setting is “auto-negotiation OFF (off) and data transfer rate fixed at 100 Mbps”, the same processing as in FIG. 4 or FIG. A connection can be established and communication can be performed.

  Further, even in a communication device that does not have an auto-negotiation function, the processing shown in FIG. 4 is performed when connection between devices cannot be made after connection between devices at a predetermined data transfer rate. Or when the predetermined transfer rate is not 100 Mbps and connection between devices is established, the processing except for the processing in steps S11 and S12 of the processing shown in FIG. 6 is performed. Of course, connection between devices may be performed.

[2. About switching the data transfer rate after establishing a connection between devices]
As described with reference to FIG. 1 to FIG. 6, even when establishing a connection between devices, the data transfer rate is as high as possible and the connection between the devices is established. It may be necessary to switch the transfer speed setting.

  For example, when establishing a connection between devices, it was possible to use a high data transfer rate, but when the communication environment deteriorates, such as noise being mixed. If the data transfer rate is low, the communication situation may be improved and good data transmission / reception may be possible.

  Conversely, when establishing a connection between devices, a low data transfer rate was used, but if the communication environment was improved thereafter, the data transfer rate could be changed to a higher one. In some cases, the communication status is improved and good data can be transmitted and received.

  Therefore, in this example, after the connection between devices is established, if it is set to use a high data transfer rate, communication errors are accumulated, and this exceeds a certain value. In such a case, the data transfer rate setting is changed to use a low data transfer rate.

  In addition, after the connection between devices is established, if it is set to use a low data transfer rate, a predetermined time e.g. after a predetermined time has elapsed from the low data transfer rate setting When the communication is continuously performed for a predetermined time or when the data download starts, the setting is changed to a high data transfer rate.

  If the accumulated value of communication errors does not exceed a predetermined value, communication is performed at a high data transfer rate, and if the accumulated value of communication errors exceeds a predetermined value, The setting is changed to use a low data transfer rate.

  FIG. 7 is a block diagram for explaining the AV apparatus of this example. As shown in FIG. 7, also in this example, the network 20 has the same configuration as that shown in FIGS. For this reason, in the network 20 shown in FIG. 7, the same reference numerals are assigned to the same components as those in the network 20 shown in FIGS. 1 and 5, and the description thereof is omitted.

  The AV device in this example is configured in substantially the same manner as the AV device 10 shown in FIG. 1 or the AV device 30 shown in FIG. 5, but in the network device driver ntwrk realized by the microcomputer 13. An error detection and speed control block errcnt is provided. Therefore, the configuration of the network device driver ntwrk on the rear side is the same as that of the AV device 10 shown in FIG. 1 or the AV device 30 shown in FIG.

  Further, a register 121 is shown in the access controller 12 shown in FIG. The register 121 is originally provided in the access controller 12, and various information such as a communication state and a communication error state is set according to the situation. For example, various pieces of information such as information indicating the data transfer rate to be used, whether or not a communication error has occurred, and a cumulative value of communication errors are stored. The information set in the register 121 is erased or updated as necessary or at a predetermined timing so that the latest information is held.

  FIG. 8 is a diagram for explaining the use of the register value of the register 121. For example, as shown in FIG. 8A, the presence / absence of a communication error is indicated by the 13th BitBitName in the range where C0h of the register 121 (the letter h indicates that C0 is a hexadecimal number) and the Tag in the range indicated by PHYSTS. If 1-bit data whose ReceiveErrorLatch is “1”, it can be known that a communication error has been detected, and if it is “0”, no communication error has been detected.

  Further, as shown in FIG. 8B, the accumulated value of the communication error is from the 0th bit of the range in which the Tag of the D4h (character h indicates that D4 is a hexadecimal number) stage of the register 121 is indicated by RECR. It can be known from data of 8 bits whose BitName up to the 7th bit is RXERCNT.

  Then, it is possible to determine whether or not to switch the high-speed data transfer rate to the low-speed data transfer rate by using the presence or absence of the error shown in FIG. 8A. In addition, the error shown in FIG. It is also possible to determine whether or not to switch a high data transfer rate to a low data transfer rate using the accumulated value.

  First, a process for determining whether or not to switch a high data transfer rate to a low data transfer rate using the information indicating the presence or absence of an error shown in FIG. 8A will be described. FIG. 9 shows whether or not the high-speed data transfer speed is switched to the low-speed data transfer speed based on the information indicating the presence / absence of the communication error stored in the predetermined position of the register 121 as described with reference to FIG. 8A. It is a flowchart for demonstrating the process made to judge.

  The processing shown in FIG. 9 is executed by the error detection and speed control block errcnt of the network device driver ntwrk when the network controller 12 detects that some operation has occurred. First, the error detection and speed control block errcnt determines whether or not data has been received, for example, by checking information in the register 121 (step S21).

  If it is determined in step S21 that the data has been received, as shown in FIG. 8A, the 13th bit information of the C0 stage of the register 121 is checked to determine whether a communication error has occurred. (Step S22). If it is determined in step S22 that a communication error has occurred, in this case, the error detection and speed control block errcnt determines whether the connected device is an auto-negotiation-compatible device (step S23). The determination in step S23 can be made based on, for example, a flag (AnegAutoMax100) set in the register 121.

  When it is determined in step S23 that the connection destination device is an auto-negotiation-compatible device, the error detection and speed control block errcnt increments the value of the error number counter held by itself by the register 121. Based on the predetermined value, it is determined whether or not the selected data transfer rate is 100 Mbps (step S24).

  If it is determined in step S24 that the data transfer rate is 100 Mbps, the error detection and speed control block errcnt determines whether or not the value of the error number counter held by itself exceeds a predetermined allowable number of errors. Is determined (step S25). When it is determined in step S25 that the number of errors exceeds the allowable value, the error detection and speed control block errcnt switches the data transfer rate setting of the register 121 to 10 Mbps and restarts (restarts) the auto negotiation. (Step S26).

  After the process of step S26 and in the determination process of step S21 described above, when it is determined that no data is received, when it is determined that no error is detected in the determination process of step S22, step S23 In the determination process, it is determined that the connected device is not an auto-negotiation-compatible device, the determination process in step S24 determines that the data transfer rate is not 100 Mbps, and the determination process in step S25 determines the number of errors. 9 is terminated, the process shown in FIG. 9 is terminated.

  In this case, in step S23, it is determined whether or not the connected device is compatible with auto-negotiation when the connected device is not an auto-negotiation-compatible device (when the device is not compatible with auto-negotiation). This is because the connection itself is lost when the device (AV device 10 or 30) switches the data transfer rate without permission.

  Then, when data is received by the processing shown in FIG. 9, it is accumulated while reliably detecting whether or not a communication error has occurred, and normal communication cannot be performed at a high data transfer rate. It is possible to detect quickly, switch to a low data transfer rate, and perform communication without delay.

  Note that the data transfer rate may be switched to 10 Mbps when it is confirmed that an error has occurred even once without accumulating the number of errors. That is, the error number increment process in step S23 in FIG. 9 may be omitted, and the process in step S25 may be omitted.

  Next, processing for determining whether or not to switch a high data transfer rate to a low data transfer rate using the information indicating the error accumulation value shown in FIG. 8B will be described. FIG. 10 shows whether or not to switch the high-speed data transfer rate to the low-speed data transfer rate based on the information indicating the accumulated error value stored in the predetermined position of the register 121 as described with reference to FIG. 8B. It is a flowchart for demonstrating the process made to judge.

  The processing shown in FIG. 10 is executed by the error detection and speed control block errcnt of the network device driver ntwrk when, for example, an interrupt (timer interrupt) is generated by a timer that measures a predetermined time interval. The

  First, in this example, the error detection and speed control block errcnt determines whether or not the connection destination device is an auto-negotiation compatible device (step S31). The determination in step S31 can be made based on, for example, a flag (AnegAutoMax100) set in the register 121.

  If it is determined in step S31 that the connection destination device is an auto-negotiation-compatible device, the error detection and speed control block errcnt selects the data transfer selected based on a predetermined value in the register 121. It is determined whether the speed is 100 Mbps (step S32).

  If it is determined in step S32 that the data transfer rate is 100 Mbps, the error detection and speed control block errcnt refers to the accumulated value of the communication error updated in the register 121 as described with reference to FIG. 8B. It is determined whether or not this exceeds a predetermined allowable number of errors (step S33). When it is determined in step S33 that the accumulated error value has exceeded the allowable value, the error detection and speed control block errcnt switches the data transfer rate setting of the register 121 to 10 Mbps and restarts (restarts) auto-negotiation. (Step S34).

  After the process of step S34 and in the determination process of step S31 described above, when it is determined that the connection destination device is not compatible with auto-negotiation, it is determined that the data transfer rate is not 100 Mbps in the determination process of step S32. If it is determined in step S33 that the accumulated error value does not exceed the allowable value, the processing shown in FIG. 10 is terminated.

  In this case, in step S31, it is determined whether or not the connection destination device is compatible with auto-negotiation, as in the determination process of step S23 shown in FIG. This is because the connection itself is lost if the device (AV device 10 or 30) on this side switches the data transfer rate without permission (if it is a device that does not support auto-negotiation).

  In the case of FIG. 10, the load of the microcomputer 13 can be reduced by using the communication error accumulation function provided in the access controller 12, and normal communication can be performed at a high data transfer rate. It is possible to quickly detect a case where there is no data and switch to a low data transfer rate to perform communication without delay.

  As described above, by performing the processing of FIG. 9 or FIG. 10, when a high data transfer rate (in this example, 100 Mbps) is used, the accumulated value of the communication error is set in advance. When a predetermined value (for example, 10 times or more in 5 seconds) is exceeded, it is determined that communication cannot be properly performed using a high data transfer rate, and a low data transfer rate (in this example) Is switched to 10 Mbps).

  The data switching can be completed in a very short time, and the data transfer speed can be switched without interrupting the communication process. In addition, the data transfer speed can be switched without bothering the user. When the data transfer rate is 100 Mbps, even if normal communication cannot be performed due to the influence of noise, for example, the data transfer rate is reduced to 10 Mbps, so that it is affected by noise. Rather, data can be sent and received properly.

  In addition, the data transfer rate can be made appropriate in accordance with the actual occurrence status of communication errors and the predetermined error tolerance. That is, even if the data transfer rate is changed, various settings and procedures are not performed more than necessary.

  In addition, when a low data transfer rate is set when establishing a connection between devices, as described above, for example, at a predetermined timing such as after a lapse of a certain time from the setting, the network device driver The ntwrk function automatically changes the setting to use a high data transfer rate.

  Then, as described with reference to FIG. 9 or FIG. 10, by performing processing when a high data transfer rate is used, not only at the time of establishing a connection between devices, but also after that Even during the communication period, the data transfer rate can be appropriately switched. Moreover, it is possible to perform both the switching process (changing) from a high data transfer rate to a low data transfer rate and the switching (changing) from a low data transfer rate to a high data transfer rate. I have to.

[Others]
In the above-described embodiment, two types of data transmission rates of 10 Mbps and 100 Mbps have been described as examples. However, the present invention is not limited to this. The present invention can be applied even when a plurality of data transfer speeds that can be selected are three or more.

  For example, when it is possible to use three or more different data transfer rates and autonegotiation is performed as a default setting, when connection between devices cannot be established by autonegotiation, FIG. As shown in the above, switch from the fastest data transfer rate to a slower data transfer rate to establish a connection between devices, and communicate using the data transfer rate at which the connection was established You can do it.

  In addition, when three or more different data transfer rates can be used, and the default setting is to connect devices at a predetermined data transfer rate other than the maximum data transfer rate, When the connection between the devices can be established at a predetermined data transfer rate, first, the connection between the devices is established by auto-negotiation as in the process shown in FIG. If the connection between the devices cannot be established, switch from the fastest data transfer rate to a slower data transfer rate to establish a connection between devices, and communicate using the data transfer rate at which the connection was established You can do that.

  In this case, in the case of a communication device that does not have an auto-negotiation function, the connection between devices is switched from the highest data transfer rate to a lower data transfer rate, except for the establishment of device connection by auto-negotiation. The communication may be performed using the data transfer rate at which the connection is established.

  In addition, after establishing a connection between devices, if communication errors occur frequently, switch to a lower data transfer rate, if no communication error occurs, switch to a higher data transfer rate, Communication processing may be performed. In addition, after switching to a slower data transfer rate, a predetermined timing, for example, a certain time after the current data transfer rate is set, a certain time after the start of data supply, or a predetermined time Switch to a higher data transfer rate at a predetermined timing, such as immediately before downloading a fixed amount of data, and if the error frequency does not exceed the predetermined value, continue communication at the higher data transfer rate after the switch. Thus, when the error frequency becomes higher than a predetermined value, the data transfer speed may be switched to a lower speed.

  In the above-described embodiment, the connection determination and setting switching block detchg realizes a determination unit, a first determination unit, a second determination unit, a transfer rate switching unit, and a transfer rate control unit, and a network device driver. ntwrk and the access controller 12 realize setting connection means and automatic connection means.

  Further, the error detection and speed control block errdet implements detection means, low speed direction changing means, and high speed direction changing means.

  In the above-described embodiment, the case where the present invention is applied to an AV apparatus having a communication function has been described as an example. However, the present invention is not limited to this. For example, the present invention can be applied to various network devices having a personal computer and a communication function.

  In the above-described embodiment, the OS used in the AV device is described as being used in Linux (registered trademark) images, but is not limited to this, and is not limited to non-event driven other than Linux (registered trademark). The present invention can also be applied to network devices using a system OS or an event-driven OS.

[List of abbreviations used in this specification]
WAN: Wide Area Network
LAN: Local Area Network
ADSL: Asymmetric Digital Subscriber Line
AV: Audio and Visual
CPU: Central Processing Unit
DHCP: Dynamic Host Configuration Protocol
IC: Integrated Circuit
IP: Internet Protocol
ISP: Internet Service Provider
OS: Operating System

1 is a block diagram for connecting an AV device to which the present invention is applied and a network to which the AV device is connected. FIG. It is a figure for demonstrating the process in the case of determining whether the connection between apparatuses has been established. It is a figure for demonstrating the process in the case of determining whether the connection between apparatuses has been established. 3 is a flowchart for explaining a data transfer rate setting switching process executed in the AV device shown in FIG. 1. It is a block diagram for demonstrating the other example of AV apparatus with which this invention was applied. 6 is a flowchart for explaining a data transfer rate setting switching process executed in the AV device shown in FIG. 5. It is a block diagram for demonstrating the other example of AV apparatus with which this invention was applied. 4 is a diagram for explaining an example of data held in a register of the access controller 12. FIG. 6 is a flowchart for explaining processing for determining whether to switch a high data transfer rate to a low data transfer rate based on information indicating the presence or absence of a communication error stored in a predetermined position of a register. is there. 6 is a flowchart for explaining processing for determining whether or not to switch a high-speed data transfer rate to a low-speed data transfer rate based on information indicating an accumulated error value stored in a predetermined position of a register. .

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 30 ... AV apparatus, 11 ... Connector jack, 12 ... Access controller, 13 ... Microcomputer, 20 ... Network, dhcpclt ... DHCP client daemon, kernel ... Kernel, ntwrk ... Network device driver, detchg ... Connection judgment and setting switching block , Hooker ... hook program, hotplug ... hot plug script, lnkdet ... link detection block, chgdet ... setting switching / determination block, 121 ... register, error detection and speed control block

Claims (12)

One of a plurality of data transfer rates can be selected and used, and at the start of communication, communication conditions are confirmed by negotiating with the counterpart device, and between devices. A communication device having an automatic connection mode for establishing a connection,
Automatic connection means for establishing a connection between devices in the automatic connection mode;
Based on a signal supplied from the counterpart device, a determination means for determining whether or not a connection has been established with the counterpart device;
When it is determined by the determining means that a connection cannot be established, the automatic connection mode is turned off, and the data transfer speed is sequentially switched from a high data transfer speed to a low data transfer speed to connect devices. A transfer speed switching means to be established;
Each time the data transfer rate is switched by the transfer rate switching means, it is determined whether or not a connection between devices has been established, and communication is performed using the data transfer rate when it is determined that a connection between devices has been established. And a transfer rate control means for controlling the communication device. A setting connection mode that allows one of a plurality of data transfer rates to be selected and used, and establishes connection between devices at a predetermined data transfer rate at the start of communication. A communication device having
A setting connection means for establishing a connection between devices using a data transfer speed that is not a maximum speed as the predetermined data transfer speed according to the setting connection mode;
Based on a signal supplied from the counterpart device, a determination means for determining whether or not a connection has been established with the counterpart device;
If the determination means determines that the connection between the devices has been established, the data transfer rate is sequentially switched from a higher data transfer rate to a lower data transfer rate to establish a connection between the devices. Transfer speed switching means;
Each time the data transfer rate is switched by the transfer rate switching means, it is determined whether or not a connection between devices has been established, and communication is performed using the data transfer rate when it is determined that a connection between devices has been established. And a transfer rate control means for controlling the communication device. A setting connection mode in which one of a plurality of data transfer rates can be selected and used, and a connection between devices is established at a predetermined data transfer rate at the start of communication; A communication device having an automatic connection mode in which a communication condition is confirmed by negotiating with a counterpart device and a connection between the devices is established,
A setting connection means for establishing a connection between devices using a data transfer speed that is not a maximum speed as the predetermined data transfer speed according to the setting connection mode;
First, when the connection between the devices is established by the setting connection means, based on a signal supplied from the counterpart device, it is determined whether or not the connection with the counterpart device is established. Discriminating means, and
When it is determined that the connection between devices can be established by the first determining means, automatic connection means for establishing a connection between devices in the automatic connection mode;
Secondly, after establishing the connection between the devices by the automatic connection means, it is determined whether or not the connection with the counterpart device can be established based on a signal supplied from the counterpart device. Discrimination means;
When it is determined by the second determination means that the connection between the devices cannot be established, the automatic connection mode is turned off, and the data transfer rate is sequentially changed from a higher data transfer rate to a lower data transfer rate. Transfer speed switching means for establishing a connection between devices by switching to
Each time the data transfer rate is switched by the transfer rate switching means, it is determined whether or not a connection between devices has been established, and communication is performed using the data transfer rate when it is determined that a connection between devices has been established. And a transfer rate control means for controlling the communication device. A communication device adapted to select and use one of a plurality of data transfer rates,
A detecting means for detecting a communication error frequency when communication is performed using a data transfer speed other than at least the minimum data transfer speed;
When the error frequency detected by the detection means is equal to or higher than a predetermined value, the low-speed direction change is performed so that the communication is continued by changing to a data transfer speed lower than the current data transfer speed. And a communication device. The communication device according to claim 4,
High-speed direction change means for controlling to continue communication by changing to a data transfer speed higher than the present at a predetermined timing after changing the data transfer speed to a low data transfer speed by the low-speed direction change means A communication apparatus comprising: A communication device adapted to select and use one of a plurality of data transfer rates,
If communication is performed using a data transfer rate other than at least the maximum data transfer rate, change to a data transfer rate that is faster than the current data transfer rate and continue communication at a determined timing. High-speed direction changing means to control,
A detecting means for detecting a communication error frequency when communication is performed using a data transfer speed other than at least the minimum data transfer speed;
When the error frequency detected by the detection means is equal to or higher than a predetermined value, the low-speed direction change is performed so that the communication is continued by changing to a data transfer speed lower than the current data transfer speed. And a communication device. One of a plurality of data transfer rates can be selected and used, and at the start of communication, communication conditions are confirmed by negotiating with the counterpart device, and between devices. A transfer rate switching method in a communication device having an automatic connection mode for establishing a connection,
An automatic connection step for establishing a connection between devices in the automatic connection mode;
A determination step of determining whether or not a connection has been established with the counterpart device based on a signal supplied from the counterpart device;
In the determination step, when it is determined that a connection cannot be established, the automatic connection mode is turned off, and the data transfer rate is sequentially switched from a high data transfer rate to a low data transfer rate to connect devices. A transfer rate switching step to be established;
In the transfer rate switching step, each time the data transfer rate is switched, it is determined whether or not a connection between devices has been established, and communication is performed using the data transfer rate when it is determined that a connection between devices has been established. And a transfer rate control step for controlling the transfer rate to be performed. A setting connection mode that allows one of a plurality of data transfer rates to be selected and used, and establishes connection between devices at a predetermined data transfer rate at the start of communication. A transfer speed switching method in a communication device having:
A setting connection step for establishing a connection between devices using a data transfer speed that is not the highest speed as the predetermined data transfer speed by the setting connection mode;
A determination step of determining whether or not a connection has been established with the counterpart device based on a signal supplied from the counterpart device;
In the determination step, when it is determined that the connection between the devices has been established, the data transfer rate is sequentially switched from the higher data transfer rate to the lower data transfer rate to establish the connection between the devices. A transfer speed switching step;
In the transfer rate switching step, each time the data transfer rate is switched, it is determined whether or not a connection between devices has been established, and communication is performed using the data transfer rate when it is determined that a connection between devices has been established. And a transfer rate control step for controlling the transfer rate to be performed. A setting connection mode in which one of a plurality of data transfer rates can be selected and used, and a connection between devices is established at a predetermined data transfer rate at the start of communication; A transfer speed switching method in a communication device having an automatic connection mode in which communication conditions are confirmed by negotiating with a counterpart device and a connection between the devices is established,
A setting connection step for establishing a connection between devices using a data transfer speed that is not the highest speed as the predetermined data transfer speed according to the setting connection mode;
In the setting connection step, when establishing a connection between the devices, based on a signal supplied from the counterpart device, it is determined whether or not the connection with the counterpart device has been established. 1 discrimination step;
In the first determination step, if it is determined that a connection between devices has been established, an automatic connection step for establishing a connection between devices in the automatic connection mode;
In the automatic connection step, after establishing the connection between the devices, it is determined whether or not the connection with the counterpart device can be established based on a signal supplied from the counterpart device. Determining step,
If it is determined in the second determining step that the connection between the devices cannot be established, the automatic connection mode is turned off, and the data transfer rate is sequentially changed from a higher data transfer rate to a lower data transfer rate. A transfer rate switching step to establish a connection between devices by switching to
In the transfer rate switching step, each time the data transfer rate is switched, it is determined whether or not a connection between devices has been established, and communication is performed using the data transfer rate when it is determined that a connection between devices has been established. A transfer rate control step for controlling the transfer rate to be performed. A transfer rate switching method during communication processing of a communication device that can select and use one of a plurality of data transfer rates,
A detection step for detecting a communication error frequency when communication is performed using at least a data transfer rate other than the minimum data transfer rate;
When the error frequency detected in the detection step is equal to or higher than a predetermined value, the low speed direction change is performed so that the communication is continued by changing to a data transfer speed lower than the current data transfer speed. And a transfer rate switching method characterized by comprising: The transfer rate switching method according to claim 10,
A high-speed direction changing step for controlling to continue communication by changing to a data transfer speed higher than the present at a predetermined timing after changing the data transfer speed to a low data transfer speed in the low-speed direction changing step. A transfer rate switching method characterized by comprising: A transfer rate switching method during communication processing of a communication device that can select and use one of a plurality of data transfer rates,
If communication is performed using a data transfer rate other than at least the maximum data transfer rate, change to a data transfer rate that is faster than the current data transfer rate and continue communication at a determined timing. A high-speed direction change step to control,
A detection step for detecting a communication error frequency when communication is performed using at least a data transfer rate other than the minimum data transfer rate;
When the error frequency detected in the detection step is equal to or higher than a predetermined value, the low speed direction change is performed so that the communication is continued by changing to a data transfer speed lower than the current data transfer speed. And a transfer rate switching method characterized by comprising:

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