JP4506350B2 - Controller equipment connected to the IEEE1394 serial bus - Google Patents

Description

  The present invention relates to a device connected to an IEEE1394 serial bus (hereinafter abbreviated as a bus), and more particularly to a technique for determining the highest data transfer rate that can be realized between each connected device on the bus.

  Conventionally, according to the IEEE1394.1995 standard, a transmission-side connected device on the bus uses a speed map stored in a bus manager register on the bus when transferring data to a connected device on the bus. Reads the information on the maximum data transfer rate of the physical layer when transferring data to the connected device on the receiving side, and determines the data transfer rate to the connected device on the receiving side based on the information on the maximum data transfer rate of the physical layer. It was decided.

  However, the maximum transfer rate of the link layer related to the connection device on the transmission side or the reception side may be slower than the maximum transfer rate of the physical layer read from the speed map. Packets received at the physical layer are lost at the link layer. Therefore, in the field of this type of connected equipment, when a bus reset occurs, the bus manager reads the maximum transfer speed of the link layer from the configuration ROM of the other connected equipment, and the maximum transfer speed of this link layer is the physical layer. In a case where the maximum transfer rate is slower than the maximum transfer rate, the maximum transfer rate stored in the speed map is corrected according to the content of the maximum transfer rate of the link layer (for example, Patent Document 1). reference).

  In addition, in the field of this type of connected device, the maximum communication speed of the physical layer of the own device is set so that all connected devices do not need to store a table for determining the communication speed with other devices. When the lowest communication speed of the physical layer of all connected devices is the lowest, do not create a table for determining the communication speed with other devices, A device that performs communication is known (for example, see Patent Document 2).

However, in IEEE1394a.2000, which is a new standard related to IEEE1394, the bus manager does not store the speed map in the unit register. Therefore, when the bus manager on the bus is a connected device that conforms to the IEEE1394a.2000 standard, the invention based on the existence of the speed map disclosed in Patent Document 1 cannot be implemented. Further, in the invention disclosed in Patent Document 2, since only the maximum communication speed of the physical layer of each connected device is considered, the maximum transfer rate of the link layer of each connected device is slower than the maximum transfer rate of the physical layer. In addition, it is impossible to determine the optimum transfer rate between the connected devices, and it is impossible to solve the problem that the packet received by the receiving-side connected device at the physical layer is lost at the link layer.
Japanese Patent Laid-Open No. 10-290237 (page 1-5, FIG. 1-6) JP 2000-259542 A (page 1-5, FIGS. 1-4)

  The present invention has been made to solve the above-described problem. When the bus manager on the bus is a connection device compliant with the IEEE1394a.2000 standard, the maximum transfer rate of the link layer of each connection device is Even if the transfer rate is slower than the maximum transfer rate of the physical layer, it is possible to determine the optimum transfer rate between each connected device, so that the packet received by the receiving connected device at the physical layer is lost at the link layer. It is an object of the present invention to provide a connection device to an IEEE1394 serial bus that can prevent this from happening.

  In order to achieve the above object, the invention of claim 1 is a transfer rate determination database which is connected to other connected devices via an IEEE1394 serial bus and stores information on the maximum transfer rate between the connected devices on the bus. Transfer rate determination database creation means for creating a transfer rate, a transfer rate determination database created by the transfer rate determination database creation means, a configuration ROM storing information on the performance of the own device, and a register specific to each device In the connection device to the IEEE1394 serial bus that has a memory that stores unit registers, etc., whether the bus manager is an old type connection device that only complies with IEEE1394.1995 from the memory in the bus manager on the bus , An old and new tie that reads information on whether it is a new type of connected device compliant with IEEE1394a.2000 Group information reading means, new link layer transfer speed reading means for reading link layer maximum transfer speed information stored in the link_spd field in the configuration ROM of other connected devices on the bus, and in the bus manager on the bus A topology map reading means for reading topology map data including information on the connection state of each connected device on the bus and information on the maximum transfer speed of the physical layer from the memory of When the type of bus manager read by the old and new type information reading means is a new type, information on the maximum transfer speed of the physical layer for each connected device in the topology map read by the topology map reading means and the new link layer transfer speed Read by reading means New transfer rate determination database creation means for creating a transfer rate determination database based on the link layer maximum transfer rate information for each connected device, and the type of bus manager read by the old and new type information reading means An old transfer rate determination database that creates a transfer rate determination database based on information on the maximum transfer rate of the physical layer for each connected device in the topology map read by the topology map reading means when the is an old type The new transfer rate determination database creation unit is an old type connection device that only complies with IEEE1394.1995 when determining the transfer rate between the connection devices. In the link_spd field of the corresponding connected device read by the new link layer transfer rate reading means When 0 is set, it is considered that the maximum transfer rate of the link layer of the connected device is 100 Mbps. When each connected device is a new type of connected device compliant with IEEE1394a.2000, the link of the connected device Assuming that the maximum transfer rate of the layer is the transfer rate corresponding to the value set in the link_spd field, the maximum transfer rate of the physical layer of each connected device is compared with the maximum transfer rate of the link layer. The maximum transfer rate of each of the connected devices is the actual maximum transfer rate of the connected device, the actual maximum transfer rate of the connected device on the data transmission side, the actual maximum transfer rate of the connected device on the data receiving side, and the connected device that relays the data Compared to the maximum transfer rate of the physical layer, the lowest transfer rate among these is transferred between the connected device on the sending side and the connected device on the receiving side. The feed speed is set.

  In the above configuration, when the type of bus manager read by the old and new type information reading means is a new type, information on the maximum transfer rate of the physical layer regarding each connected device in the topology map read by the topology map reading means, Based on the link layer maximum transfer rate information regarding each connected device read by the new link layer transfer rate reading unit, a new transfer rate determination database creation unit creates a transfer rate determination database. The new transfer rate determination database creation means compares the maximum transfer rate of the physical layer with the maximum transfer rate of the link layer when determining the transfer rate between the connected devices. The maximum transfer speed is set to the actual maximum transfer speed of each connected device. As a result, when the bus manager on the bus is a new type of connection device that supports the IEEE1394a.2000 standard, even if the maximum transfer rate of the link layer of each connection device is slower than the maximum transfer rate of the physical layer, Determine the maximum transfer rate that can be achieved between each connected device based on the data in the transfer rate determination database that considers both the maximum transfer rate of the physical layer and the maximum transfer rate of the link layer of each connected device. Can do. Therefore, it is possible to prevent the packet received by the receiving side connected device at the physical layer from being lost at the link layer.

  The new transfer rate determination database creation means determines whether the transfer rate between the connected devices is an old type of connected device that conforms only to IEEE1394.1995, and the new link layer transfer rate. When the link_spd field of the corresponding connected device read by the reading means is set to 0, it is considered that the maximum transfer rate of the link layer of the connected device is 100 Mbps, and each connected device is a new device that conforms to IEEE1394a.2000. When it is a type of connected device, the maximum transfer rate of the link layer of the connected device is regarded as the transfer rate corresponding to the value set in the link_spd field. This makes it possible to determine the new transfer speed even if the connected devices on the bus contain both old-type connected devices that comply only with IEEE1394.1995 and new-type connected devices that comply with IEEE1394a.2000. Based on the data in the database created by the database creation means, it is possible to determine the highest transfer rate that can be achieved between the connected devices.

  Furthermore, the new transfer rate determination database creation means compares the maximum transfer rate of the physical layer of each connected device with the maximum transfer rate of the link layer when determining the transfer rate between the connected devices. The maximum transfer rate of the other device is the actual maximum transfer rate of each connected device, the actual maximum transfer rate for the connected device on the data transmission side, the actual maximum transfer rate for the connected device on the data receiving side, and the connected device that relays data The highest transfer rate of the physical layer is compared, and the lowest transfer rate among these is set as the transfer rate between the connection device on the transmission side and the connection device on the reception side. As a result, when the maximum transfer rate of the physical layer in the connection device that relays data is higher than the maximum transfer rate of the link layer, the data transfer rate from the connection device on the transmission side to the connection device on the reception side is Therefore, it is possible to prevent a decrease in the transfer rate caused by relaying data from being minimized.

Further, the invention of claim 2 is a transfer rate for creating a transfer rate determination database which is connected to other connected devices via an IEEE1394 serial bus and stores information on the maximum transfer rate between each connected device on the bus. Judgment database creation means, transfer speed judgment database created by transfer speed judgment database creation means, configuration ROM storing information on performance of own device, unit register which is a register unique to each device, etc. Connected to an IEEE1394 serial bus with a memory that stores the memory , the bus manager is an old type of connection device that conforms only to IEEE1394.1995, or the IEEE1394a.2000 Old and new type information reading means for reading information on whether it is a compliant new type of connected device, A new link layer transfer rate reading means for reading the link layer maximum transfer rate information stored in the link_spd field in the configuration ROM of the other connected devices on the bus, and the memory in the bus manager on the bus. And a topology map reading means for reading topology map data including information on the connection state of each connected device and information on the maximum transfer speed of the physical layer, and the transfer speed determination database creating means is a new and old type information reading means. When the type of the read bus manager is a new type, information on the maximum transfer rate of the physical layer regarding each connected device in the topology map read by the topology map reading unit and each read by the new link layer transfer rate reading unit Connected devices Based on the maximum transfer rate of the information of the link layer that a new transmission speed determination database creation means for creating a database for determining the transfer rate, the type of the bus manager read by old type information reading means is a older Sometimes, it comprises an old transfer rate determination database creation unit that creates a transfer rate determination database based on information on the maximum transfer rate of the physical layer for each connected device in the topology map read by the topology map reading unit The new transfer rate determination database creation means determines the transfer rate between each connected device, and if each connected device is a new type of connected device compliant with IEEE1394a.2000, the link layer of the connected device is used. Is the maximum transfer rate corresponding to the value set in the link_spd field As if there were, by comparing the maximum transfer rate of the maximum transfer rate and the link layer of the physical layer of each connected device, the lower data transfer rates up to a substantially maximum transfer speed of each connection device, the data transmission side Compare the real maximum transfer rate for the connected device with the real maximum transfer rate for the connected device on the data receiving side and the maximum transfer rate of the physical layer for the connected device that relays data. Is the transfer rate between the transmitting-side connected device and the receiving-side connected device.

  According to the first aspect of the present invention, when the bus manager type is a new type of connection device corresponding to the IEEE1394a.2000 standard, the maximum transfer rate of the physical layer and the maximum transfer rate of the link layer of each connection device are In comparison, the lower maximum transfer rate is set to the actual maximum transfer rate of each connected device. As a result, when the bus manager on the bus is a new type of connection device that supports the IEEE1394a.2000 standard, even if the maximum transfer rate of the link layer of each connection device is slower than the maximum transfer rate of the physical layer, Determine the maximum transfer rate that can be achieved between each connected device based on the data in the transfer rate determination database that considers both the maximum transfer rate of the physical layer and the maximum transfer rate of the link layer of each connected device. Can do. Therefore, it is possible to prevent the packet received by the receiving side connected device at the physical layer from being lost at the link layer.

  Also, when determining the transfer rate between each connected device, each connected device is an old type connected device that complies only with IEEE1394.1995, and the corresponding connected device read by the new link layer transfer rate reading means. When the link_spd field is set to 0, the maximum transfer rate of the link layer of the connected device is regarded as 100 Mbps. This makes it possible to determine the new transfer speed even if the connected devices on the bus contain both old-type connected devices that comply only with IEEE1394.1995 and new-type connected devices that comply with IEEE1394a.2000. Based on the data in the database created by the database creation means, it is possible to determine the highest transfer rate that can be achieved between the connected devices.

  Furthermore, when determining the transfer rate between each connected device, the maximum transfer rate of the physical layer of each connected device is compared with the maximum transfer rate of the link layer, and the lower maximum transfer rate is determined for each connected device. Compared to the actual maximum transfer rate for the connected device on the data transmission side, the actual maximum transfer rate for the connected device on the data receiving side, and the maximum transfer rate of the physical layer for the connected device that relays data. Then, the lowest transfer speed among these is set as the transfer speed between the connection device on the transmission side and the connection device on the reception side. As a result, when the maximum transfer rate of the physical layer in the connection device that relays data is higher than the maximum transfer rate of the link layer, the data transfer rate from the connection device on the transmission side to the connection device on the reception side is Therefore, it is possible to prevent a decrease in the transfer rate caused by relaying data from being minimized.

  The best mode for carrying out the present invention will be described with reference to the drawings. The embodiments described below do not cover the present invention, and the present invention is not limited to the following modes. The connection device (connection device to the IEEE1394 serial bus) according to the present embodiment is a bus manager connected to another connection device via the IEEE1394 serial bus.

  FIG. 1 shows an electrical block configuration of the bus manager according to the present embodiment and other connected devices on the IEEE1394 serial bus. The bus manager 1 is connected to a data transmission side connection device 3 (hereinafter abbreviated as a transmission side device) and a data reception side connection device 4 (hereinafter abbreviated as a reception side device) via an IEEE1394 serial bus 9. ing.

  The bus manager 1 has a CPU 11 and a memory 12 for storing various data. The CPU 11 not only controls the entire apparatus, but also functions as an application layer on the IEEE1394 protocol. The memory 12 also includes a transfer rate determination database (transfer rate determination DB) 13 that stores information on the maximum transfer rate between each connected device on the bus, and a program for creating the transfer rate determination DB 13 ( Transfer speed determination DB creation PG) 14, a register space 15 in which various information related to the bus manager 1 itself and other connected devices on the bus 9 are stored. The transfer rate determination DB creation PG 14 and the CPU 11 correspond to the transfer rate determination database creation unit, the new transfer rate determination database creation unit, and the old transfer rate determination database creation unit in claim 1. Further, as in the present embodiment, when the bus manager 1 itself is a device having the transfer speed determination DB 13 (hereinafter referred to as a transfer speed information providing device), the CPU 11 reads the old and new type information reading means in the claims and It also functions as a topology map reading means.

  The bus manager 1 also includes a LINK 16 that provides a link layer level service on the IEEE1394 protocol, a PHY 17 that provides a physical layer level service, and an IEEE1394 port 18 for connecting a cable of the bus 9. ing. These LINK 16, PHY 17 and IEEE1394 port 18 correspond to the new link layer transfer rate reading means in claim 1.

  Similarly to the bus manager 1, the transmission side device 3 and the reception side device 4 have CPUs 31 and 41, memories 32 and 42, LINKs 36 and 46, PHYs 37 and 47, and IEEE1394 ports 38 and 48. The memory spaces 32 and 42 contain register spaces 35 and 45, respectively. However, unlike the bus manager 1, the transfer speed determination DB 13 and the transfer speed determination DB creation PG 14 are not stored in the memories 32 and 42.

  Next, contents of data stored in the register space 15 in the bus manager 1 will be described with reference to FIG. The register space 15 includes a CSR (Control and Status Registers) core 51 used for controlling the own device and other connected devices, a serial bus dependent register 52 that is a register for managing the bus 9, and information on the performance of the own device. And the like, and a unit register 54 which is a register unique to each device.

  The serial bus dependency register 52 stores BUS_MANAGER_ID 55 that stores the physical ID of the bus manager 1. The bus_info_block 56 in the configuration ROM 53 stores link_spd 57 that is information on the maximum transfer rate of the link layer of the own device.

  The unit register 54 stores a TOPOLOGY_MAP (topology map) 60 including information on the connection status of each connected device on the bus 9 and information on the maximum transfer rate of the physical layer. The TOPOLOGY_MAP 60 is created by the CPU 11 when the bus is reset. FIG. 2 shows a data structure in the register space 15 in the case where the bus manager 1 is a new type of connected device corresponding to the IEEE1394a.2000 standard. When the bus manager 1 is an old type connection device that only complies with IEEE1394.1995, the link_spd 57 is not stored in the bus_info_block 56 in the configuration ROM 53, and the highest transfer of the physical layer between the connection devices in the unit register 54 SPEED_MAP (speed map) that is speed information is stored.

  Similarly to the register space 15 in the bus manager 1, the register spaces 35 and 45 in the transmission side device 3 and the reception side device 4 are also a CSR core 51, a serial bus dependent register 52, a configuration ROM 53, and a unit. The configuration ROM 53 stores a link_spd 57 similar to the above.

  Next, the contents of information stored in the TOPOLOGY_MAP 60 in FIG. 2 will be described with reference to FIG. The TOPOLOGY_MAP 60 includes node_count76, which is information on the number of nodes on the bus 9, self_id_count77, which is information on the number of self ID packets stored in the TOPOLOGY_MAP 60, and self ID packets (self_id_packet [0] to self_id_packet [self_id_count- 1]) and the like.

  Next, the contents of the self ID packet included in the self ID packet table 78 in FIG. 3 will be described with reference to FIGS. 4 to 6 by taking the case of IEEE1394a.2000 as an example. As shown in FIG. 4, the first type self ID packet 79 (hereinafter referred to as a first self ID packet) 79 is a Phy_ID 80 indicating the physical ID of a node (hereinafter referred to as a transmission source node) that has transmitted the packet. , Sp81, which is information on the maximum transfer rate of the physical layer related to the transmission source node, p0 information 82-p2 information 84 indicating the state of each port of p0-p2, and whether a packet having the same physical ID follows. Additional packet presence / absence information m85 and the like are stored. When the p0 information 82 to the p2 information 84 are “11”, this indicates that “the corresponding node is operating and connected to the child port”, and when the information is “10”, “the corresponding node is operating. Connected to the parent port ". Further, “01” indicates that “the corresponding node is not operating”, and “00” indicates that “the corresponding port does not exist”.

  As shown in FIG. 5, a second type self ID packet (hereinafter referred to as a second self ID packet) 86 includes Phy_ID 80 indicating the physical ID of the transmission source node and p3 indicating the state of each port of p3 to p10. Information 87 to p10 information 94, additional packet presence / absence information m85 indicating whether or not a packet having the same physical ID follows is stored. Further, as shown in FIG. 6, a third type self ID packet (hereinafter referred to as a third self ID packet) 95 indicates the state of each port of Phy_ID 80 and p11 to p15 indicating the physical ID of the transmission source node. P11 information 87 to p15 information 100 shown in FIG.

  Next, a process for creating the transfer rate determination DB 13 shown in FIG. 1 will be described with reference to the flowchart of FIG. When the bus reset process is completed, the bus manager 1 shown in FIG. 1 reads the old and new type types from the memory 12 (S1). When the type type of the bus manager 1 is “new” (YES in S2), new type processing is performed (S3), and when it is not “new” (NO in S2), old type processing is performed (S4). Here, the type classification “new” indicates that the connected device is a new type compliant with IEEE1394a.2000, and the type classification is not “new” (type classification is “old”). Indicates that it is an old type connection device that only complies with.

  Next, an outline of the new type process shown in S3 of FIG. 7 will be described with reference to the flowchart of FIG. When entering the new type process, the bus manager 1 reads the data of the TOPOLOGY_MAP (topology map) 60 from the unit register 54 (S11). Next, the data in link_spd 57 is read from the configuration ROM 53 of each connected device on the bus 9 (S12). Then, the bus manager 1 receives information on the maximum transfer rate of the physical layer of each connected device (sp81 in FIG. 4) included in the data in the TOPOLOGY_MAP 60 read in the process of S11 and each read in the process of S12. Based on the link layer maximum transfer rate information (link_spd 57) related to the connected device, the transfer rate determination DB 13 (see FIG. 1) is created when the bus manager 1 is a new type (S13).

  Next, details of the new transfer rate determination DB creation processing shown in S13 of FIG. 8 will be described with reference to FIGS. 10 to 12 in addition to the flowchart of FIG. FIG. 10 shows an example of the configuration of a device connected to the bus 9, and FIG. 11 compares the information on the maximum transfer rate of the link layer of each device with the information on the maximum transfer rate of the physical layer. The state of determining the maximum transfer speed is shown. FIG. 12 shows the contents of the transfer rate determination DB 13 in the case of the device configuration shown in FIG. In the following description, the word “device” is used as a word having the same meaning as that of the connected device. As shown in FIG. 10, when the device connected to the IEEE1394 serial bus cable 101 (hereinafter abbreviated as “cable”) is only a new type device, the configuration ROM 53 of each device A, B, C, D is used. A value corresponding to the maximum transfer rate of the link layer of each device A, B, C, D is set in link_spd 57. The values set in link_spd 57 are “010”, “001”, and “000”, respectively, when the maximum transfer rate of the link layer is 400 Mbps, 200 Mbps, and 100 Mbps.

  As shown in FIG. 9, when entering the new transfer rate determination DB creation process, the bus manager 1 reads information on the maximum transfer rate of the physical layer of each device read in the process of S11 in FIG. The actual maximum transfer rate of each device is determined by comparing the information of the maximum transfer rate of the link layer related to each device read in the process of S12 in the middle (S21). Specifically, as shown in FIG. 11, the maximum transfer rate of the link layer and the maximum transfer rate of the physical layer for each device A, B, C, and D are compared, and the lower transfer rate is set for each device. A substantial maximum transfer speed of A, B, C, and D (hereinafter referred to as a substantial maximum transfer speed). Then, the bus manager 1 determines the transfer rate between the devices directly connected via the cable 101 as the actual maximum transfer rate related to the data transmission side device and the actual maximum transfer rate related to the data reception side device. In comparison, the lower transfer rate is set as the transfer rate between the corresponding devices in the transfer rate determination DB 13 (S22). For example, regarding the transfer rate between the device A and the device B shown in FIG. 10, the actual maximum transfer rate (the highest transfer rate after determination) relating to the device A shown in FIG. Compared with the maximum transfer rate of 200 Mbps, as shown in FIG. 12, the lower transfer rate of 200 Mbps is set as the transfer rate between the devices AB in the transfer rate determination DB 13.

  On the other hand, the bus manager 1 relates to the transfer rate between devices indirectly connected via other devices, the maximum transfer rate related to the device on the data transmission side, and the device on the data reception side. The actual maximum transfer rate is compared with the maximum transfer rate of the physical layer related to the device that relays data, and the lowest transfer rate among these is set as the transfer rate between the corresponding devices in the transfer rate determination DB 13. (S23). For example, regarding the transfer rate between the device B and the device D shown in FIG. 10, the actual maximum transfer rate (the maximum transfer rate after the determination) relating to the device B shown in FIG. The maximum transfer rate of 100 Mbps and the physical layer maximum transfer rate of 400 Mbps for the device C that relays data are compared, and as shown in FIG. 12, the lowest transfer rate of 100 Mbps is obtained. The transfer speed between the devices BD in the transfer speed determination DB 13 is used. In addition, in the processing of S23, the reason why the physical layer maximum transfer rate is used as the maximum transfer rate for the device that relays data is that the link layer of the device that relays data is data only regardless of the data transfer. This is because it is involved in forwarding. Therefore, for example, for the transfer rate between the device A and the device C shown in FIG. 10, the bus manager 1 has a maximum physical layer transfer rate of 400 Mbps related to the device B that relays data, and the actual transfer rate of the device A. The maximum transfer rate of 400 Mbps is compared with the actual maximum transfer rate of 400 Mbps for device C, and as shown in FIG. 12, the lowest transfer rate of 400 Mbps is determined as the transfer rate determination DB 13. The transfer speed between devices AC in the network. The bus manager 1 determines the transfer speed between devices in the transfer speed determination DB 13 shown in FIG. 12 by repeating the processing shown in S21 to S23.

  Next, referring to FIG. 13 and FIG. 14, among the devices on the bus 9, there are a mixture of an old type device compliant only with IEEE1394.1995 and a new type device compliant with IEEE1394a.2000. A process of creating the transfer rate determination DB 13 in this case will be described. In the following description, a process of creating the transfer rate determination DB 13 when the device corresponding to the bus manager 1 on the bus 9 is a new type device compliant with IEEE1394a.2000 will be described. A value corresponding to the maximum transfer rate of the link layer of the device is not set in link_spd57 (see FIG. 2) of the old type device compliant with only IEEE1394.1995, and a fixed value “000” is set. Has been. When “000” is set in the link_spd 57 of each device, the bus manager 1 regards the maximum transfer rate of the link layer for the corresponding device as 100 Mbps regardless of whether or not each device is a new type. . Accordingly, as shown in FIG. 13, even when the old type devices B and D and the new type devices A and C are mixed in each device on the bus 9, as shown in FIG. It is possible to create a transfer speed determination DB 13 that stores the transfer speed between devices, and to determine the highest transfer speed that can be achieved between the devices based on the data of the transfer speed determination DB 13.

  Next, with reference to FIG. 16 in addition to the flowchart of FIG. 15, the old type process shown in S4 of FIG. 7 will be described. Upon entering this process, the bus manager 1 creates a SPEED_MAP (speed map) based on the data stored in the topology map 60 in the unit register 54 (S31). The speed map data shown in FIG. 16 is speed map data in the case of a device configuration similar to the device configuration shown in FIG. This speed map corresponds to a transfer speed determination database when the type of the bus manager 1 is an old type. The bus manager 1 may create a speed map by directly using a self ID packet acquired from another connected device at the time of bus reset. Also, unlike the present embodiment, when the transmission side device is a transfer rate information providing device, if the bus manager is an old type, the transmission side device uses the speed map read from the bus manager as it is. Create a DB for determination.

  Next, a method for a device other than the transfer rate information providing device to acquire information on the maximum transfer rate from the transfer rate information providing device will be described with reference to the flowcharts of FIGS. In the following description, a case will be described in which the bus manager 1 shown in FIG. 1 is a transfer rate information providing device and a new type of connection device compliant with IEEE1394a.2000. In such a case, the transmission side device 3 and the reception side device 4 that do not have information on the maximum transfer speed between the connected devices are each a new type device that conforms to IEEE1394a.2000. Programs having contents as shown in FIG. 17 are stored in the memories 32 and 42 (see FIG. 1). According to this program, for example, when the transmission side device 3 transmits data to the reception side device 4, the transmission side device 3 transmits the unit register 54 in the register space 15 of the bus manager 1 (transfer rate information providing device). The contents of OxEFFC to OxFFFC are inquired by a read block packet (S41), and information on the maximum transfer rate between the transmission side device 3 and the reception side device 4 is acquired from the bus manager 1 (S42).

  On the other hand, when the transmission side device 3 and the reception side device 4 are old-type connection devices compliant with only IEEE1394.1995, the transmission side device 3 and the reception side device 4 are stored in the respective memories 32 and 42 (see FIG. 1). 18 stores a program having the contents shown in FIG. According to this program, for example, when the transmission side device 3 transmits data to the reception side device 4, the transmission side device 3 reads the contents of the speed map stored in the unit register 54 of the bus manager 1 in the read block. An inquiry is made with a packet (S51), and transfer rate information is acquired (S52).

  When the bus manager 1 is a transfer rate information providing device and a new type of connection device compliant with IEEE1394a.2000, the bus manager 1 stores the diagram in the memory 12 (see FIG. 1). A program having the contents as shown in FIG. 19 is stored. According to this program, the bus manager 1 makes an inquiry about the contents of OxEFFC to OxFFFC of the unit register 54 of its own unit with a read block packet from a new-type transmitting device 3 or receiving device 4 compliant with IEEE1394a.2000. When received (YES in S61), instead of returning the values of OxEFFC to OxFFFC of the unit register 54 of the own device, the information of the transfer rate determination DB 13 is returned to the transmitting device 3 or the receiving device 4 (S62). ). In addition, the bus manager 1 inquires about the contents of the speed map stored in the unit register 54 of its own device with a read block packet from the old-type transmission side device 3 or reception side device 4 that complies only with IEEE1394.1995. When received (YES in S63), instead of returning the value of the speed map to the transmission side device 3 or the reception side device 4, the information of the transfer speed determination DB 13 is returned (S64).

  As described above, the bus manager 1 holds the program having the contents as shown in FIG. 19, and the transmission side device 3 and the reception side device 4 have the contents as shown in FIG. 17 or FIG. By doing so, the connected devices other than the transfer rate information providing device on the bus 9, that is, the transmitting side device 3 and the receiving side device 4, send information on the maximum transfer rate between these devices to the bus manager 1 (transfer rate). It can be obtained from the information providing device).

  As described above, according to the bus manager 1 according to the present embodiment, when the type of the bus manager 1 is a new type of connection device corresponding to the IEEE1394a.2000 standard, each connection device included in the data in the TOPOLOGY_MAP 60. By comparing the maximum transfer rate information of the physical layer and the link layer maximum transfer rate information included in link_spd57, the lower maximum transfer rate is set to the actual maximum transfer rate of each connected device. . As a result, the bus manager 1 on the bus 9 is connected to the IEEE1394a. Even if the maximum transfer rate of the link layer of each connected device is slower than the maximum transfer rate of the physical layer when it is a new type of connected device that supports the 2000 standard, the maximum transfer rate of the physical layer of each connected device Based on the data in the transfer rate determination DB 13 that considers both the maximum transfer rates of the link layer, it is possible to determine the highest transfer rate that can be realized between the connected devices. Therefore, it is possible to prevent the packet received by the receiving side device 4 at the physical layer from being lost at the link layer.

  Further, when determining the transfer rate between the connected devices stored in the transfer rate determination DB 13, the maximum transfer rate of the physical layer and the maximum transfer rate of the link layer of each connected device are compared. Is the actual maximum transfer rate of each connected device, the actual maximum transfer rate for the data transmission side device 3, the actual maximum transfer rate for the data reception side device 4, and the physical layer for the connection device that relays the data And the lowest transfer speed among them is set as the transfer speed between the transmission side device 3 and the reception side device 4. As a result, when the maximum transfer rate of the physical layer in the connected device that relays data is higher than the maximum transfer rate of the link layer, the data transfer rate from the transmission side device 3 to the reception side device 4 is relayed. Therefore, it is possible to prevent a decrease in the transfer rate caused by relaying data, since it is possible to prevent a decrease in accordance with the maximum transfer rate of the link layer of the connected device.

  In addition, this invention is not restricted to the said embodiment, Various deformation | transformation are possible. For example, in this embodiment, the new type of bus manager 1 acquires information on the maximum transfer rate of the physical layer of each connected device by reading the topology map data after the bus reset. Information on the maximum transfer rate of the physical layer related to each connected device may be acquired from the self-ID packet received from each connected device. In the above embodiment, the bus manager 1 is a transfer rate information providing device. However, a connected device corresponding to the transmission side device 3 in the above embodiment may be a transfer rate information providing device. In this case, the LINK, PHY and IEEE1394 ports of the transmission side device become the old and new type information reading means and the topology map reading means in claim 1.

The figure which shows the electrical block structure of the controller apparatus which concerns on the best embodiment of this invention, and the other connection apparatus on a bus | bath. The figure which shows the content of the register space in FIG. The figure which shows the content of TOPOLOGY_MAP in FIG. The figure which shows the content of the 1st self ID packet contained in the self ID packet table in FIG. The figure which shows the content of the 2nd self ID packet contained in the self ID packet table in FIG. The figure which shows the content of the 3rd self ID packet contained in the self ID packet table in FIG. 3 is a flowchart of transfer rate determination DB creation processing in FIG. 1. The flowchart of the new type process in FIG. Flowchart of new transfer rate determination DB creation processing in FIG. The figure which shows the structural example of the device connected to a bus | bath. Explanatory drawing of the method of determining the practical maximum transfer rate of each device shown by the said structural example. FIG. 11 is a diagram showing the contents of a transfer rate determination DB in the case of the device configuration shown in FIG. 10. The figure which shows the example of a structure of a device when an old type device and a new type device coexist. The figure which shows the content of DB for transfer rate determination in the case of the device structure shown by FIG. The flowchart of the old type process in FIG. The figure which shows the content of SPEED_MAP in the case of the device structure similar to the device structure shown by FIG. The flowchart of the process of the program which acquires the maximum transfer rate information from the transfer rate information provision apparatus stored in the new type connection apparatus. The flowchart of the process of the program which acquires the maximum transfer rate information from the transfer rate information provision apparatus stored in the old type connection apparatus. The flowchart of the process of the program which returns the information of DB for transfer speed determination to the other connection apparatus stored in the transfer speed information provision apparatus.

Explanation of symbols

1 Bus manager (device connected to IEEE1394 serial bus)
9 IEEE1394 serial bus 11 CPU (new and old type information reading means, topology map reading means, transfer speed determination database creation means, new transfer speed determination database creation means, old transfer speed determination database creation means)
12 Memory 13 Transfer rate judgment DB (Transfer speed judgment database)
16 LINK (new link layer transfer rate reading means)
17 PHY (new link layer transfer rate reading means)
18 IEEE1394 port (new link layer transfer rate reading means)
53 Configuration ROM
54 Unit register 57 link_spd
60 TOPOLOGY_MAP (topology map)

Claims (2)

Connected to other connected devices via IEEE1394 serial bus,
A transfer rate determination database creating means for creating a transfer rate determination database storing information on the maximum transfer rate between each connected device on the bus;
A transfer rate determination database created by the transfer rate determination database creation means, a configuration ROM storing information relating to the performance of the device itself, and a memory storing unit registers that are unique to each device. In the equipment connected to the IEEE1394 serial bus provided,
The old and new type that reads information from the memory in the bus manager on the bus whether the bus manager is an old type connection device that only conforms to IEEE1394.1995 or a new type connection device that conforms to IEEE1394a.2000 Information reading means;
New link layer transfer rate reading means for reading information on the maximum transfer rate of the link layer stored in the link_spd field in the configuration ROM of another connected device on the bus;
Topology map reading means for reading, from the memory in the bus manager on the bus, topology map data including information on the connection state of each connected device on the bus and information on the maximum transfer rate of the physical layer;
The transfer rate determination database creation means includes:
When the type of the bus manager read by the new and old type information reading means is a new type, information on the maximum transfer rate of the physical layer regarding each connected device in the topology map read by the topology map reading means, and the new link A new transfer rate determination database creating unit that creates the transfer rate determination database based on the link layer maximum transfer rate information regarding each connected device read by the layer transfer rate reading unit;
When the type of the bus manager read by the new and old type information reading means is an old type, based on the information on the maximum transfer rate of the physical layer regarding each connected device in the topology map read by the topology map reading means, It consists of an old transfer rate determination database creation means for creating a transfer rate determination database,
The new transfer rate determination database creation means, when determining the transfer rate between the connected devices,
When each of the connected devices is an old type of connected device compliant only with IEEE1394.1995, and the link_spd field of the corresponding connected device read by the new link layer transfer rate reading means is set to 0, When the maximum transfer rate of the link layer of the connected device is regarded as 100 Mbps, and each of the connected devices is a new type of connected device compliant with IEEE1394a.2000, the maximum transfer rate of the link layer of the connected device is displayed in the link_spd field. Assuming that the transfer rate corresponds to the set value,
Comparing the maximum transfer rate of the physical layer of each connected device and the maximum transfer rate of the link layer, the lower maximum transfer rate is set as the actual maximum transfer rate of each connected device,
Compare the actual maximum transfer rate for the connected device on the data sending side, the actual maximum transfer rate for the connected device on the data receiving side, and the maximum transfer rate of the physical layer for the connected device that relays data. The IEEE1394 serial bus connection device is characterized in that the lowest transfer rate is the transfer rate between the transmission-side connection device and the reception-side connection device. Connected to other connected devices via IEEE1394 serial bus,
A transfer rate determination database creating means for creating a transfer rate determination database storing information on the maximum transfer rate between each connected device on the bus;
A transfer rate determination database created by the transfer rate determination database creation means, a configuration ROM storing information relating to the performance of the device itself, and a memory storing unit registers that are unique to each device. In the equipment connected to the IEEE1394 serial bus provided ,
The old and new type that reads information from the memory in the bus manager on the bus whether the bus manager is an old type connection device that only conforms to IEEE1394.1995 or a new type connection device that conforms to IEEE1394a.2000 Information reading means;
New link layer transfer rate reading means for reading information on the maximum transfer rate of the link layer stored in the link_spd field in the configuration ROM of another connected device on the bus;
Topology map reading means for reading, from the memory in the bus manager on the bus, topology map data including information on the connection state of each connected device on the bus and information on the maximum transfer rate of the physical layer;
The transfer rate determination database creation means includes:
When the type of the bus manager read by the new and old type information reading means is a new type, information on the maximum transfer rate of the physical layer regarding each connected device in the topology map read by the topology map reading means, and the new link A new transfer rate determination database creating unit that creates the transfer rate determination database based on the link layer maximum transfer rate information regarding each connected device read by the layer transfer rate reading unit ;
When the type of the bus manager read by the new and old type information reading means is an old type, based on the information on the maximum transfer rate of the physical layer regarding each connected device in the topology map read by the topology map reading means, It consists of an old transfer rate determination database creation means for creating a transfer rate determination database,
The new transfer rate determination database creation means, when determining the transfer rate between the connected devices,
When each connected device is a new type of connected device compliant with IEEE1394a.2000, the maximum transfer rate of the link layer of the connected device is regarded as a transfer rate corresponding to the value set in the link_spd field,
Comparing the maximum transfer rate of the physical layer of each connected device and the maximum transfer rate of the link layer, the lower maximum transfer rate is set as the actual maximum transfer rate of each connected device,
Compare the real maximum transfer rate for the connected device on the data sending side, the real maximum transfer rate for the connected device on the data receiving side, and the maximum transfer rate of the physical layer for the connected device that relays data. The IEEE1394 serial bus connection device is characterized in that the lowest transfer rate is the transfer rate between the transmission-side connection device and the reception-side connection device.

Images