JPH11145995A - Data transmission system using bus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure resource acquisition and to provide a data transfer method in the case of connecting plural base of different resource acquisition methods. SOLUTION: If a PC(personal computer) 1, a camera 2 and a video telephone 4 are USB(universal serial bus) equipment, while a satellite broadcasting receiver 5 and a recorder 6 are IEEE1394 equipment, an adapter 3 functions as a mediation between USB and IEEE1394. The PC 1 performs the role of a host of data transfer with the USB. When an instruction is given from a user at the time of requesting isochronous transfer to the USB equipment after initialization of the IEEE1394, the PC 1 issues a request to an isochronous resource manager and acquires isochronous transfer to start with. Then, pipe connection to the USB is requested to the adapter 3, and when it succeeds, the isochronous transfer is started. The adapter 3 receives the data on an IEEE1394 bus and transfer the received data to the host 1, or the host 1 receives image data from the camera 2 and sends them to the adapter 3, which sends them to the IEEE1394.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transfer method for a serial bus, and more particularly, to a data transfer method between IEEE1394 and USB.

[0002]

2. Description of the Related Art In recent years, personal computers (hereinafter, referred to as PCs), PC peripheral devices such as printers and scanners, digital video disks (hereinafter, referred to as DVDs), digital video cameras (hereinafter, referred to as DV cameras), and the like are interconnected. IEEE1394 (IEEE Standby)
ard for a High Performance Serial Bus) and USB (Univ
ersal Serial Bus) is gaining attention.

Meanwhile, the maximum transfer speed of IEEE1394 is 400 megabits per second (Mbps), while that of USB is relatively low at 12 megabits per second (Mbps). Also US
B allows only a star topology centering on a host (usually a PC is the host) and is used as an interface for connecting low-speed PC peripherals such as a keyboard, mouse, and telephone. In contrast,
IEEE1394 can be used as an interface for applications that handle large-capacity data such as images, as well as the low-speed devices described above. Therefore, it seems that whether to equip USB or IEEE1394 depends on the device.

[0004] However, there is a demand for transferring data of a device equipped only with USB to a device equipped only with IEEE1394. It is conceivable to equip both, but of course, there is a problem of cost increase.

[0005] IEEE1394 and USB maintain the order of data flowing on the bus by managing bus resources such as transfer bandwidth and transfer channel.
An example of a bus resource management method is proposed in Japanese Patent Application Laid-Open No. 7-38579.

[0006]

The problem to be solved by the present invention is disclosed in Japanese Patent Application Laid-Open No.
In the conventional management method described in Japanese Patent Publication No. 79, one of the connection nodes manages the bus resources collectively, and is the same method adopted in the IEEE1394 standard. On the other hand, in USB, a host (usually a PC) manages bus resources collectively (USB Specification Versi
on1.0).

Therefore, according to the above-mentioned prior art, data from a device equipped with only IEEE1394 is transferred to a device equipped with only USB, or a device equipped with only USB is transferred to a device equipped with only IEEE1394. In such a case, the difference between these bus resource management methods becomes a problem.

An object of the present invention is to provide a data transmission system which solves such a problem and which enables a bus resource management method to transfer data between different buses.

[0009]

To achieve the above object, the present invention provides a first bus and a second bus which manage resources on a bus by one bus resource management device on the bus. In the data transmission method between the connected devices, when a resource request of the first bus is received from a device on the second bus, the first bus resource management device sends the first bus resource management device to the first bus resource management device. For the bus resource acquisition request of the bus.

The first bus and the second bus are connected by USB, IEEE1
A different type, such as 394, allows the bus resource management device to exchange data between devices on the first bus and devices on the second bus.

Here, the bus resource management device is an IEEE13
94 USB-1 having packet decoding means, USB control means, IEEE1394 resource acquisition control means, USB pipe establishment control means, USB packet decoding means, and IEEE1394 control means
Configure the 394 adapter.

An IEEE 1394 packet transmitted to this adapter via the IEEE 1394 bus is transmitted via the IEEE 1394 control means.
The packet is decoded by the IEEE1394 packet decoding unit. If the packet indicates a USB resource request, it instructs the USB pipe establishment control means to establish a pipe between the USB and IEEE1394 adapters. The USB pipe establishment means requests the host to establish a new pipe via the USB control means. If the pipe is successfully established, the fact is communicated to the USB packet decoding means via the USB control means. The USB packet decryption means informs the IEEE 1394 node which issued the USB resource acquisition request via the IEEE 1394 control means whether the pipe has been successfully established.

On the other hand, when the USB packet received via the USB control means indicates an IEEE 1394 resource request, the IEEE 1394 resource acquisition control means is notified to the IEEE 1394 resource acquisition control means.
Instructs to acquire resources (Isochronous bandwidth, channel number). The IEEE 1394 resource acquisition control unit transmits the Isoc on the IEEE 1394 bus through the IEEE 1394 control unit.
Request resource acquisition from the hronous resource manager node. If the acquisition is successful, the IE
Via EE1394 control means and IEEE1394 packet decoding means
Informed to USB control means. The USB control means informs the USB host whether or not the IEEE1394 resource acquisition has succeeded.

With the above operations, resources can be obtained between IEEE1394 and USB, and data can be transferred between them.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of a bus data transmission system according to the present invention, wherein 1 is a PC,
2 is a digital still camera, 3 is a USB-1394 adapter, 4
Is a videophone, 5 is a digital satellite broadcast receiver (hereinafter, I
RD), 6 is a digital video cassette recorder (hereinafter referred to as DVCR), 7 to 9 are USB cables, 1
Reference numerals 0 and 11 are IEEE1394 cables.

In FIG. 1, a PC 1, a digital still camera 2 and a video phone 4 are devices equipped with USB only (ie, USB devices), and the IRD 5 and DVCR 6 are IEEE 139 devices.
A device equipped with only 4 (ie, an IEEE1394 device).
The USB-1394 adapter 3 serves as a bridge between USB and IEEE1394. In USB, data is always exchanged via a host, but here, the PC 1 plays the role of the host. Hereinafter, the PC 1 will be described as a host.

Next, from the USB device in this embodiment, the IEEE1
Isochro to 394 devices and from IEEE1394 devices to USB devices
The nous resource acquisition method will be described. The configuration is performed independently on the USB side and the 1394 side.

In USB, an address of a connected device is allocated by the host 1. In one device, 1
To 16 endpoints can be set. In FIG. 1, it is assumed that the address and endpoint of the USB device are set as shown in Table 1 below.

[0019]

[Table 1]

Regarding the view of Table 1, for example, the videophone 4 is assigned an address 2 by the host 1, and data is transferred from the videophone 4 to the host 1 by the endpoint 1. It is assumed that endpoint 0 (default) is naturally set in each device.

On the other hand, in IEEE1394, a physical ID is assigned to each IEEE1394 device instead of an address. In FIG. 1, it is assumed that the physical IDs of the IEEE1394 devices are assigned as shown in Table 2 below.

[0022]

[Table 2]

The USB-1394 adapter 3 is a feature of the present embodiment.
It is also recognized as one device from the four sides.

This embodiment performs two operations (these operations are referred to as operation A-1 and operation A-2, respectively).
These operations will be described with reference to FIGS.

In the operation A-1, an image of the digital still camera 2 on the USB bus 7 is transferred by the IEEE
There is an operation for recording on DVCR6 on E1394 bus,
The operation A-2 is performed on the DVCR 6 on the IEEE1394 buses 10 and 11.
This is an operation of transferring the image data of (1) to the videophone 4 on the USB bus 9 by the isochronous transfer method.

In IEEE1394, before starting the isochronous transfer, a request must be issued to the only isochronous resource manager existing on the bus to acquire the bandwidth and the channel. With USB, when a USB device is connected to the bus, it must declare the resources to be used to the host 1 and acquire a pipe.

In the following description, when establishing a USB pipe, it is described that a pipe establishment request can be issued to the host 1. In an actual USB, the pipe establishment process is performed only when a device is connected. It is supposed to be. Therefore, when a new pipe is established, a process for temporarily disconnecting the device from the bus and reconnecting the device is performed.

(1) Operation A-1: FIG. 2 is a flowchart showing the operation of the host 1 when the USB device transmits data on the IEEE1394 bus in an isochronous manner.
Is a flowchart showing the operation of the USB-1394 adapter 3 at that time.

In FIG. 2, in the initial state, as described above, both the IEEE1394 and the USB are independently configured (step 201), and the settings are as shown in Tables 1 and 2 above. .

The user instructs the PC 1 to “control the digital still camera 2 and convert the image data to the isochronous
The data is transferred to the host 1 according to the transfer method.
(Step 202). Therefore, the host 1 first refers to the USB isochronous resource managed by itself, and establishes a pipe for transmitting image data between the digital still camera 2 (source device) and the host 1 (step 20).
3) Further, a pipe for transferring this image data to the USB-1394 adapter 3 is newly established between the USB-1394 adapter 3 and the USB-1394 adapter 3 (step 204) (the endpoint at this time is set to 2).

The digital still camera 2 and the host 1
Step 203 is not required if a pipe for image transfer has already been established between. In the first embodiment, a pipe has already been established as shown in Table 1 (address 1, end point 1).

The host 1 further transmits an IEEE 1394 isochronous resource (bandwidth 8M) to the USB-1394 adapter 3.
bps, channel number 1) Issue an acquisition request instruction (step 205). Upon receiving this command, the USB-1394 adapter 3 requests the isochronous resource manager on the IEEE1394 bus to acquire the isochronous resource, and when the acquisition is successful, notifies the host 1 of the success of the acquisition of the IEEE1394 resource (returns a response). ). IEEE1394Isochron
Upon confirming the success of the ous resource acquisition, the USB host 1 sends an image data transmission command to the digital still camera 2, and transmits the received image data to the USB-1394 adapter 3 (step 206). USB-1394 adapter 3 is the IE
Image data is transmitted to EE1394Isochronous channel 1. I
The DVCR 6 on the EEE1394 bus can record image data by listening to (receiving) the isochronous channel 1.

FIG. 3 shows the USB-1394 in the above operation A-1.
6 is a flowchart illustrating an operation of the adapter 3.

In the figure, the USB-1394 adapter 3 is an IEEE
Since it has both 1394 and USB functions, it is configured as shown in Tables 1 and 2 above (Step 301). When an IEEE 1394 resource acquisition request is received from the host 1 (step 302), Isoc on the IEEE 1394 bus is
A resource acquisition request is issued to a hronous resource manager (hereinafter, IRM) (step 303). If the resource acquisition is successful, the host 1 (resource acquisition request issuing source) is notified of the fact (304), and data reception is started (step 305). The received data is
Talk (transmit) to channel 1 according to the acquired resources (step 306).

(2) Regarding operation A-2: FIG.
94 is a flowchart showing an IEEE 1394 node (DVCR 6 in this operation) when the device transmits data on the USB bus in an isochronous manner. FIG. 5 shows the USB-1394 adapter 3 at that time.
6 is a flowchart showing the operation of the embodiment.

In FIG. 4, in the initial state, as described above, the IEEE 1394 and the USB are independently configured (step 401), and the USB and the IEEE 1394 are configured.
Are set as shown in Tables 1 and 2, respectively.

First, the DVCR 6 is connected to the Isochr of the IEEE1394 bus.
onous resource (bandwidth 5Mbps, channel number 2)
Are obtained (steps 402 and 403). When the acquisition of the IEEE1394 resource is successful, a request is issued to the USB-1394 adapter 3 (step 404), and the acquisition of the isochronous resource of the USB bus is performed. When confirming that the USB resource has been successfully acquired, the DVCR 6 transmits the image data to the channel 2 (step 405).

USB-1394 adapter 3 by host 1 or the like
Listens to channel 2 and sends the received data to host 1.
By controlling the host 1 to transmit to the
The image data transmitted by the CR 6 can be received.
Further, when the host 1 transmits the received image data to the videophone 4, the image of the DVCR 6 can be displayed or transferred to a telephone line.

FIG. 5 shows the USB-1394 in the above operation A-2.
6 is a flowchart illustrating an operation of the adapter 3.

In the same figure, the USB-1394 adapter 3 is an IEEE
Since it has both 1394 and USB functions, it is configured as shown in Tables 1 and 2 (step 501). When a USB resource acquisition request is received from the DVCR 6 (IEEE1394 node) (step 502), a resource acquisition (pipe establishment) request between the host 1 and the USB-1394 adapter 3 is issued to the host 1 (step 503). US
The B-1394 adapter 3 requests, for example, the host 1 as the end point 3 to establish a pipe. When the pipe is established, USB isochronous resources have been acquired. Further, a request for establishing a pipe between the host 1 and the videophone 4 is issued to the host 1 (step 50).
4). If the resource acquisition succeeds, the DVCR 6 (resource acquisition request issuing source) is notified of the fact (step 505), and starts listening (receiving) of channel 2 on the 1394 bus (step 506). The received data is transmitted to the host 1 (Step 507). The host 1 transmits the received image data to the video phone 4.

As described above, by using the USB-1394 adapter 3, mutual resources can be obtained between the USB-1394.

FIG. 6 is a block diagram showing another embodiment of a bus data transmission system according to the present invention.
This is a 1394 host adapter, and parts corresponding to those in FIG.

This embodiment differs from the embodiment shown in FIG. 1 in that, as shown in FIG. 6, a USB-1394 host adapter 12 having a host function in the USB-1394 adapter 3 in FIG. 1 is used. Is a point. Thus, there is no need to connect the PC 1 serving as a host as shown in FIG. Also,
Management of USB resources etc. is performed by the USB-1394 host adapter 12
Since it is performed by itself, the procedure for communicating with the host can be omitted. Here, the digital still camera 2 and the video phone 4 are devices equipped with only USB (USB devices),
5 and DVCR6 are devices equipped with only IEEE1394 (IEEE139
4 devices).

In this embodiment, the operation B-1 and the operation B
-2. Here, the operation B-1 is the US
The operation B-2 is a case where the image of the digital still camera 2 on the B bus is recorded on the DVCR 6 on the IEEE1394 bus.
This is a case where image data of the DVCR 6 on the IEEE1394 bus is transferred to the videophone 4 on the USB bus. Hereinafter, these will be described with reference to FIGS.

(1) Operation B-1: FIG. 7 is a flowchart showing the operation of the USB-1394 host adapter 12 when the USB device transmits data on the IEEE1394 bus in an isochronous manner.

In the figure, in the first state, the IEEE1394
The USB and the USB are independently configured (step 701), and the settings are as shown in Tables 1 and 2. In this case, the host in the “direction” column of Table 1 is the USB-1394 host adapter 12, and the adapter at address 3 is ignored.

The user instructs the USB-1394 host adapter 12 to "control the digital still camera 2 to transfer the image data to the USB-1394 host adapter 12 by the isochronous transfer method, and to transmit this to the IEEE1394 bus. (Step 702). US
The B-1394 host adapter 12 first refers to the USB isochronous resource managed by itself, and connects the digital still camera 2 (source device) with the USB-1394 host adapter 12.
A pipe for transmitting the image data is set up between them (step 703).

The digital still camera 2 and the USB-1394
When a pipe for image transfer has already been established with the host adapter 12, step 703 is not necessary. In the embodiment shown in FIG. 6, a pipe has already been established (address 1, endpoint 1) as shown in Table 1.

The USB-1394 host adapter 12 further includes
A command to acquire an isochronous resource (bandwidth 8 Mbps, channel number 1) is issued to the IRD 5 of IEEE1394 (step 704). If the resource acquisition is successful, an image data transmission command is sent to the digital still camera 2 to start receiving image data from the digital still camera 2 (step 705). The received image data is sent to the previously acquired IEEE 1394 Isochronous channel 1 (step 706). DVCR6 on IEEE1394 bus
Can listen to (receive) the isochronous channel 1 to record image data.

(2) Operation B-2: The method of acquiring the USB bus resources from the IEEE1394 node is exactly the same as that of the operation A-2 in the embodiment shown in FIG. 1 (FIG. 4). Therefore, the description is omitted. In addition, IEEE13
Isoc with a bandwidth of 5Mbps and channel number 2 on 94 bus
Assume that hronous resources have been acquired.

FIG. 8 is a flowchart showing the operation of the USB-1394 host adapter 12.

In the figure, a USB-1394 host adapter 1
2 has both the functions of IEEE1394 and USB, so it is configured as shown in Tables 1 and 2 (Step 801). In this case, the host in the “direction” column of Table 1 is the USB-1394 host adapter 12.
And ignore the adapter at address 3.

When a USB resource acquisition request is received from the DVCR 6 (IEEE1394 node) (step 802), first,
USB device (in this case, videophone 4) and USB-1
394 A resource acquisition (pipe establishment) process with the host adapter 12 is performed (step 803). For example, the USB-1394 host adapter 12 establishes a pipe as the endpoint 3. When the pipe is established, USB Isochro
This means that nous resources have been acquired. If the resource acquisition is successful, the DVCR 6 (resource acquisition request issuer) is notified of that (step 804), and the listening (reception) of channel 2 on IEEE1394 is started (step 8).
05). The received data is transmitted to the videophone 4.

As described above, the USB-1394 having the host function
Through the USB-1394 host adapter 12, mutual resource acquisition between USB and IEEE1394 becomes possible without requesting the host for resources each time.

FIG. 9 is a block diagram showing a specific example of the USB-1394 adapter 3 shown in FIG. 1, 13 is a USB control unit, 14 is a USB packet decoding unit, 15 is an IEEE1394 resource acquisition control unit, and 16 is an IEEE1394. Control unit, 17 is IEEE1394
A packet decoding unit 18 is a pipe establishment control unit.

In the figure, a USB control unit 13 controls a USB packet configuration and other USB functions. The USB packet decryption unit 14 decrypts a USB packet, issues a command to the IEEE1394 resource acquisition control unit 15,
Transfer the data to 6. IEEE1394 packet decoding unit 17
Decrypts the IEEE1394 packet sent from the IEEE1394 control unit 16, issues an instruction to the pipe establishment control unit 18, and transfers data to the USB control unit 13.

First, the IEEE1394 of the USB-1394 adapter 3
The operation on the side will be described.

The USB-1394 adapter 3 exists as one node as an IEEE1394 bus (the physical ID of the node is assumed to be 1). Therefore, all data transmitted on the IEEE1394 bus can be monitored. Asynchrono
In the case of the us transfer method, normally, only data transmitted to its own node is taken out. However, IEEE1394 also provides a snoop mode in which all data can be monitored.

FIG. 10 is a diagram showing a specific example of an IEEE 1394 packet transmitted with the physical ID = 1. 1001 is a header field specified by the IEEE 1394 standard including the physical ID, and 1002 is for controlling the USB-1394 adapter. An adapter control field 1003 is a data field for storing data such as an image. Note that some packets do not have the data field 1003 depending on the contents of the adapter control field 1002.

In FIG. 9, upon receiving the data having the packet structure shown in FIG. 10, the IEEE1394 control unit 16 removes the IEEE1394 header field 1001 from the packet structure and replaces the adapter control field 1002 and the data field 1003 with the IEEE1394 packet decoding unit 17. Send to The IEEE 1394 packet decoding unit 17 decodes the adapter control field 1002.

FIG. 11 shows an adapter control field 1002.
FIG. 4 is a diagram showing a specific example of the bit arrangement of FIG.

In the figure, the first 4 bits are the USB-1394
Command bits 1101 for controlling the adapter 3, and the remaining 4 bits indicate a USB endpoint number 1102. Command bit 1101
Is a two-bit data indicator bit 11 that indicates whether the data field 1003 (FIG. 10) follows or not.
03 and 2-bit transfer bit 1104 indicating the transfer method
Consists of

The following Tables 3 (a) and 3 (b) show the contents of the data indicator bit 1103 and the transfer bit 1104.

[0064]

[Table 3]

In Table 3, for example, as shown in FIG.
If it is 00001, the endpoint 0001
(1 in decimal number) indicates a bulk transfer pipe establishment request, and if it is 00100010, the data field 1003 is set in the endpoint 0010 (2 in decimal number).
(FIG. 10) indicates that isochronous transfer data is transferred.

In FIG. 9, the IEEE1394 packet decoding unit 1
In step 7, the adapter control data as described above is decoded, and a pipe establishment instruction is sent to the pipe establishment control unit 18 and the instruction and data are sent to the USB control unit 13 in response to the decoding. The USB control unit 13 forms a USB packet and transfers it to the host 1 (FIG. 1) according to an instruction from the IEEE1394 packet decoding unit 17 and the pipe establishment control unit 18.

Next, the operation of the USB-1394 adapter 3 on the USB side will be described.

FIG. 12 shows a specific example of a USB data packet sent to the USB-1394 adapter 3.
Reference numeral 201 denotes an adapter control field for controlling the USB-1394 adapter 3, and 1202 denotes a data field for storing data such as an image.

It should be noted that some packets do not have the data field 1202 depending on the contents of the adapter control field 1201. In addition, these adapter control fields 12
01 and the data field 1202 are a USB data field.

In FIG. 9, the USB control unit 13 having received the data having the packet structure shown in FIG. 12 sends it to the USB packet decoding unit 14. In the USB packet decryption unit 14,
The adapter control field 1201 is decoded.

FIG. 13 shows this adapter control field 12.
It is a figure which shows one specific example of the bit arrangement of 01, and has an 8-bit structure here.

In the figure, the first 4 bits are command bits 1301 for controlling the USB-1394 adapter, and the remaining 4 bits indicate the IEEE 1394 isochronous channel, bandwidth or physical ID 1202. Command bit 1301 is data field 1
202 (FIG. 12) is followed or not followed by a 2-bit data indicator bit 1303 and a transfer scheme 2
It consists of a transfer bit 1304 of bits.

Tables 4 (a) and 4 (b) show the contents of the data indicator bit 1303 and the transfer bit 1304, respectively.

[0074]

[Table 4]

In Tables 4 (a) and 4 (b), for example, when the bit string of the command bit 1301 is 10010001, the isochronous channel 0001 (10
This indicates an IEEE1394Isochronous resource acquisition request of 1) in radix.
IEEE1394 for the bandwidth of 1010 (10 in decimal)
Indicates an Isochronous resource acquisition request. Also, 0000
If it is 0001, it indicates that the data placed in the data field 602 is to be transferred to physical ID = 0001 (1 in decimal).

The header of IEEE 1394 includes the type of transaction, data length, other codes, and the like. To supply such information from the USB side, the size of the adapter control field 1201 must be increased (here, 8 Bit).

In FIG. 9, the USB packet decoding unit 14 decodes the adapter control data as described above and sends an IEEE1394Isochronous resource acquisition command to the resource acquisition control unit 15 in response to the adapter control data. Send data. The IEEE1394 control unit 16 composes an IEEE1394 packet and transfers it to the IEEE1394 bus according to an instruction from the USB packet decoding unit 14 and the resource acquisition control unit 15.

By using the USB-1394 adapter 3 as described above, data can be transferred from USB to IEEE1394 and from IEEE1394 to USB.

Here, the IEEE1394 node from the USB side and
An embodiment of a method for recognizing a USB node from an IEEE1394 node will be described with reference to FIG.

It is assumed that the physical ID and the like are as shown in Tables 1 and 2. For example, digital still camera 2
If the user wants to send data to the IRD 5, the host 1 is requested to send a command such as "send data to the endpoint 2 of the USB-1394 adapter 3" to the USB-1394 adapter 3.

Table 5 shows a specific example of a conversion table between the end point and the physical ID of the USB-1394 adapter 3 in this case.

[0082]

[Table 5]

In Table 5, since the end point 2 is assigned to the physical ID = 1, the USB-1394 adapter 3 sends the data to the physical ID = 1 on the IEEE1394 bus, that is, the IRD. As shown in FIG. 6, when the USB-1394 host adapter 12 also functions as a host, a procedure for requesting the host is not required.

As described above, by using the USB-1394 adapter, data can be transferred from USB to IEEE1394 and from IEEE1394 to USB.

[0085]

As described above, according to the present invention,
By using an adapter which is a device for connecting a plurality of different types of buses, data transfer between the plurality of buses having different bus resource acquisition methods becomes possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a bus data transmission system according to the present invention.

FIG. 2 is a flowchart showing a specific example of the operation of the USB-1394 adapter in FIG.

FIG. 3 is a flowchart showing another specific example of the operation of the USB-1394 adapter in FIG. 1;

FIG. 4 is a flowchart showing an IEEE1394 node when the IEEE1394 device in FIG. 1 transmits data on the USB bus in an isochronous manner.

FIG. 5 is a flowchart showing the operation of the USB-1394 adapter in FIG. 1 when the IEEE1394 device shown in FIG. 4 operates.

FIG. 6 is a block diagram showing another embodiment of a bus data transmission method according to the present invention.

FIG. 7 is a flowchart showing a specific example of the operation of the USB-1394 host adapter in FIG. 6;

8 is a flowchart showing another specific example of the operation of the USB-1394 host adapter in FIG.

FIG. 9 is a block diagram showing a specific example of a USB-1394 adapter in FIG.

FIG. 10 is a diagram showing a specific example of an IEEE1394 packet transmitted as Physical ID = 1 in FIG. 1;

FIG. 11 is a diagram illustrating a specific example of a bit arrangement of an adapter control field of the IEEE1394 packet illustrated in FIG. 10;

FIG. 12 shows a US sent to the USB-1394 adapter in FIG.
FIG. 4 is a diagram illustrating a specific example of a B data packet.

13 is a diagram illustrating a specific example of a bit arrangement of an adapter control field of the USB data packet illustrated in FIG. 12;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Personal computer 2 Digital still camera 3 USB-1394 adapter 4 Videophone 5 Digital satellite broadcast receiver 6 Digital video cassette recorder 7-9 USB cable 10,11 IEEE1394 cable 12 USB-1394 host adapter 13 USB control unit 14 USB packet decoding Unit 15 IEEE1394 resource acquisition control unit 16 IEEE1394 control unit 17 IEEE1394 packet decoding unit 18 Pipe establishment control unit

Claims (24)

[Claims] 1. A data transmission system between a device connected to a first bus and a device connected to a second bus, wherein resources on the bus are managed by one bus resource management device on the bus. When a resource request for the first bus is received from a device on the bus, processing for a bus resource acquisition request for the first bus is performed on a bus resource management device for the first bus. The data transmission method of the bus. 2. The bus according to claim 1, wherein information used by said bus resource management device when acquiring bus resources can be transmitted to another connected device on said second bus. Data transmission method. 3. The system according to claim 2, wherein the information used for acquiring the transmitted bus resources is received, and a request for acquiring a bus resource of the first bus is issued using the received information. The data transmission method of the bus. 4. The device according to claim 1, wherein a response to the bus resource acquisition request of the first bus is received from the bus resource management device, and the response is transmitted to another connection device on the second bus. A bus data transmission method, characterized in that: 5. The bus data transmission method according to claim 1, wherein the first bus is a USB. 6. The information processing system according to claim 5, wherein the information used at the time of acquiring the bus resources is an endpoint,
A bus data transmission method comprising at least one of a transfer method and a bandwidth. 7. The data transmission method of a bus according to claim 1, wherein the first bus is IEEE1394. 8. The bus data transmission method according to claim 7, wherein the information used when acquiring the bus resources includes at least one of a bandwidth and a channel number. 9. A data transmission system connected to both a first bus and a second bus for managing resources on the bus by one device on the bus, wherein: A bus data transmission method having a function of performing bus resource management on the first bus by itself when a resource request for the first bus is received from one device. 10. The bus data according to claim 9, wherein information used when said bus resource management device acquires bus resources is transmitted to another connection device on said second bus. Transmission method. 11. The bus resource management device according to claim 10, further comprising: receiving the transmitted information used for acquiring the bus resources, and performing the bus resource acquisition processing of the first bus in accordance with the information. A bus data transmission method, characterized in that: 12. The bus data transmission method according to claim 9, wherein whether or not bus resource acquisition is successful is transmitted to another connected device. 13. The bus data transmission method according to claim 9, 10, 11 or 12, wherein the first bus is USB or IEEE1394. 14. The method according to claim 13, wherein the information used when acquiring the bus resources is an endpoint,
A bus data transmission method comprising at least one of a transfer method, a bandwidth, and a channel number. 15. A data transmission system in which a first bus and a second bus having at least two transfer methods are connected via an electronic device, wherein the first bus is connected to the first bus from an electronic device on the second bus. When transferring data to an electronic device on the bus, the device has a transfer method selecting means for selecting a transfer method when propagating on the first bus, and transmitting the selected transfer method to another connected device. Characteristic bus data transmission method. 16. The first bus and the second bus according to claim 15, wherein the first bus and the second bus receive the selective transfer method, and transfer data on the first bus according to the received selective transfer method. A bus data transmission system that connects to 17. A data transmission system in which a first bus and a second bus to which desired information data is added and data is transferred are connected via an electronic device. When transferring data to an electronic device on the first bus, transmitting the additional information data required when propagating on the first bus to another connected device. Bus data transmission method on the bus. 18. The method according to claim 17, wherein the additional information data is received, and data is transferred onto the first bus using the received additional information data. A data transmission method of a bus connecting the second bus and the second bus. 19. The data transmission method of a bus according to claim 15, wherein the first bus is IEEE1394. 20. The bus data transmission method according to claim 15, wherein the first bus is a USB. 21. A device is connected via a device to a first bus of a system for identifying devices on the bus by numbers and to a second bus of a system having a plurality of information input / output points in one device. A system in which one of the information input / output points in the device is virtually connected to the information input / output point in the device on the second bus; When data from a device to another information input / output point in the device is received, the other information input / output point can be assigned to the device identification number of the first bus, and the device has the assigned device identification number. A data transmission method for a bus, wherein the reception data is transmitted to a device on the first bus. 22. The bus data transmission method according to claim 21, wherein the first bus is USB or IEEE1394. 23. The bus data transmission method according to claim 21, wherein the number for identifying a device on the bus is an address or a physical ID. 24. The bus data transmission method according to claim 21, wherein the plurality of information input / output points in the one device are addresses or endpoints.