JPH11355319A - Data communication system, method and device and digital interface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely and continuously transfer the object data which require no real time performance by making at least one of a source node, a destination node and a controller discontinue the transfer of data. SOLUTION: A digital video recorder having 1394 interfaces is used as a source node 302 to secure a transfer function of the object data 308, and a printer having a function to receive the data 308 from the node 302 is used as a destination node 304. Meanwhile, a computer having 1394 interfaces is used as a controller 200, and one or more connections are set between the node 302 and one or more nodes 304 for management of the controller 200. These connections are set by the controller 200 when a transfer request is received for the data 308. When the connections are set, the data 308 are transferred between the nodes 302 and 304 with no control of the controller 200. Thus, the load of the controller 200 is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication system, a data communication method, a data communication device, and a digital interface, and more particularly to a network for performing high-speed communication by mixing information data (including image data) and command data. It relates to a communication protocol applicable to the network.

[0002]

2. Description of the Related Art Conventionally, personal computers (hereinafter, referred to as personal computers).
Among the peripheral devices of the personal computer (PC), hard disk drives and printers were the most frequently used. These peripheral devices are provided by a dedicated input / output interface or SCSI (sm
all computer system inter
face) and a general-purpose digital interface such as an interface.

On the other hand, in recent years, digital cameras, digital video cameras, and other AV (Audio / Visual)
Devices are also attracting attention as one of the peripheral devices of PCs.
These AV (Audio / Visual) devices are also connected to a PC via a dedicated interface.

FIG. 11 is a diagram showing a conventional communication system composed of a PC and AV equipment. In FIG. 11, 101 is an AV device (digital camera), 102 is a PC, and 103 is a printer.

In the digital camera 101, 104
Is a memory for compressing and recording the captured image, 105 is a decoding unit for expanding and decoding the compressed image data recorded in the memory 104, 106 is an image processing unit, 107 is a D / A converter, and 108 is an EVF A display unit 109 is a dedicated digital I / O unit for connecting the digital camera 101 and the PC 102.

In the PC 102, 110 is the PC 102
A digital I / O unit for connecting the camera to the digital camera 101; 111, an operation unit including a keyboard and a mouse; 112, a decoding unit for expanding and decoding compressed image data; 113, a display; 115 is a memory such as a RAM, 116 is an MPU, 11
7 is a PCI bus, 118 is a PC 102 and a printer 103
Is a SCSI interface for connecting

In the printer 103, 119 is a SCSI interface for connecting the printer 103 and the PC 102, 120 is a memory, 121 is a printer head, 12
Reference numeral 2 denotes a printer controller for controlling the operation of the printer 103, and reference numeral 123 denotes a driver.

In a conventional communication system, a digital interface (digital I / O unit 109) of the digital camera 101 and a digital interface (SCSI interface 11) of the printer 103 are provided.
0) and was not compatible with them.

For this reason, when the digital camera 101 wants to communicate, for example, a still image to the printer 103, the digital camera 101 must be connected via a PC. Also, with the conventional dedicated interface or SCSI interface, especially when handling large amounts of data such as still images and moving images of AV equipment, the data transfer rate is low, the communication cable is thick for parallel communication, and connection is possible. There have been many problems such as a small number and types of peripheral devices, limitations on connection methods, and inability to perform real-time data transfer.

As one of the next-generation high-speed, high-performance digital interfaces that solves such problems, I.
EEE (The Institute of Elec)
tritical and Electronics En
giners, Inc. ) The 1394-1995 standard is known.

A digital interface (hereinafter, 1394 interface) conforming to the IEEE 1394-1995 standard has the following features. (1) High data transfer rate, (2) Real-time data transfer method (that is, Isoc
asynchronous transfer method) and Asynchronous
Supports transfer method. (3) A highly flexible connection configuration (topology) can be constructed. (4) Supports plug-and-play function and hot-swap function.

[0012]

SUMMARY OF THE INVENTION However, the IEEE
The E1394-1995 standard defines the physical and electrical configuration of the connector, the two most basic data transfer methods, and the like. However, what kind of data is used in what data format, The communication protocol based on which transmission / reception is not defined.

[0013] Also, according to the IEEE 1394-1995 standard,
In the sochronous transfer method, since a response to an outgoing packet is not specified, each isochronous transfer method
It is not guaranteed that the ous packet has been received.

Therefore, when it is desired to reliably transfer a plurality of continuous data, or when it is necessary to surely transfer one file data by dividing it into a plurality of data, Isoch is used.
The roonous transfer method could not be used,

[0015] Also, according to the IEEE 1394-1995 standard,
In the sochronous transfer method, the total number of communications is limited to 64 even if there is a vacancy in the transfer band. For this reason, if you want to perform many communications with a small transfer band,
The Isochronous transfer method could not be used,

According to the IEEE 1394-1995 standard, when a bus reset occurs in response to ON / OFF of a power supply of a node, connection / disconnection of a node, and the like, data transfer must be interrupted.

However, according to the IEEE 1394-1995 standard, when data transfer is interrupted due to a bus reset or an error during transmission, it is impossible to know what data has been lost. Further, in order to recover the transfer once interrupted, it was necessary to take a very complicated communication procedure.

Here, the bus reset is a function for automatically recognizing a new topology and setting an address (node ID) assigned to each node. With this function, the IEEE1394-1995 standard uses plugs
An AND play function and a hot-swap function can be provided.

Also, in a communication system conforming to the IEEE 1394-1995 standard, object data (for example, still image data, graphics data, text data, etc.) that does not require real-time but requires a relatively large amount of data for which reliability is required. A communication protocol for dividing data, file data, program data, and the like into one or more segment data and continuously transferring the data has not been specifically proposed.

In a communication system conforming to the IEEE 1394-1995 standard, a communication protocol for realizing data communication between a plurality of devices using a communication system for asynchronously broadcasting data has not been proposed. ,

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a technique for continuously and reliably transferring object data that does not require real-time processing in a data communication system, a data communication method, a data communication device, and a digital interface. It is intended to provide. Further, another object of the present invention is to provide a data communication system, a data communication method, a data communication device, and a digital interface for transmitting data continuously transferred between a source node and one or more destination nodes in a complicated manner. It is an object of the present invention to provide a technique that can be reliably stopped by a simple procedure without executing a complicated communication procedure. Another object of the present invention is to solve the inconvenience of the conventional communication system, to transfer data at high speed and easily, and to ensure that data can be transferred. . Another object of the present invention is to enable simultaneous multi-field communication when the communication band is not used much. Another object of the present invention is to make it possible to easily detect data lost due to interruption of data transfer and to reliably and easily recover from the interruption of data transfer. The purpose is to:

[0022]

A data communication system according to the present invention comprises a source node for transferring data comprising one or more segments using at least one asynchronous communication, and a data communication system for transferring data transferred from the source node. And at least one destination node for receiving, and a controller for setting a logical connection relationship between the source node and the one or more destination nodes, wherein the source node, the destination node, At least one of the controllers stops transferring the data. According to another feature of the data communication system of the present invention, a source node that transfers data including one or more segments using at least one broadcast communication based on a logical connection relationship; One or more destination nodes receiving the data transferred from the source node and the source node or the one or more destination nodes stop transferring the data based on a logical connection relationship. It is characterized by. Another feature of the data communication system of the present invention is that communication is performed using a logical connection relationship set between a transmitting device that transmits information data and a receiving device that receives the information data. A logical connection relationship in which the transmitting device or the receiving device opens the logical connection relationship. Another feature of the data communication system of the present invention is a data communication system using a communication system for continuously and asynchronously transmitting a plurality of communication packets, wherein a response from a device receiving the information is provided. Has not passed the specified period,
A logical connection relationship for stopping transmission of the information. Other features of the data communication system of the present invention include:

The data communication method according to the present invention includes a step of transferring data comprising one or more segments to one or more destination nodes using at least one broadcast communication based on a logical connection relationship;
Receiving the data transferred from the source node based on the logical connection relationship; and stopping the transfer of the data by the source node or the one or more destination nodes. And Another feature of the data communication method of the present invention is that communication is performed using a logical connection relationship between a transmitting device that transmits information data and a receiving device that receives the information data. A data communication method applicable to a data communication system, wherein the logical connection relationship is opened to the transmitting device or the receiving device. Another feature of the data communication method of the present invention is a data communication method using a communication method for continuously and asynchronously transmitting a plurality of communication packets, wherein a response from a device receiving the information is provided. Is a logical connection relationship in which transmission of the information is stopped when a predetermined period has not elapsed. Another feature of the data communication method of the present invention is a data communication method applicable to a data communication system constituted by a plurality of devices, wherein communication of a plurality of different devices is performed by a plurality of different ID information. Is determined by
A logical connection relationship that terminates the communication by not responding to the communication. Further, other features of the data communication method of the present invention, a transmitting device that transmits information data, a receiving device that receives the information data,
A data communication method applicable to a data communication system including a management device that manages communication of the information data, wherein the transmission is performed so as to set a logical connection relationship between the transmission device and the reception device. A logical connection relationship that controls any of the transmission device, the reception device, and the management device so as to release the logical connection relationship after controlling the device, the reception device, and the management device. Another feature of the data communication method of the present invention is a data communication method using a communication method for continuously and asynchronously transmitting a plurality of communication packets, wherein information transmitted by the communication method is used. A logical connection relationship in which the information is stored in the same area of the memory space of the plurality of devices and the information is retransmitted according to a waiting time for a response to the reception of the information.

[0024] The data communication apparatus of the present invention comprises means for packetizing data comprising one or more segments into at least one communication packet, and a logical connection relationship established between one or more destination nodes. And means for asynchronously transferring the communication packet using the method described above, wherein the asynchronous transfer of the at least one communication packet can be stopped.

[0025] The digital interface of the present invention comprises: means for receiving at least one communication packet asynchronously transferred using a logical connection relationship established with a source node; Means for writing to a common memory space with another device, wherein the asynchronous transfer of the at least one communication packet can be stopped. Another feature of the digital interface of the present invention is that a logical connection is established between the source node and one or more destination nodes, and the logical connection is identified. A connection ID for notifying the connection ID to the source node and the one or more destination nodes and stopping the data transfer based on the logical connection.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a data communication system, a data communication method, a data communication device and a digital interface according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating an example of a configuration of a data communication system according to the present embodiment. As shown in FIG. 1, the data communication system of this embodiment includes a computer 10, a camera-type digital video recorder 28, and a printer 60.

First, the configuration of the computer 10 will be described. An arithmetic processing unit (MPU) 12 controls the operation of the computer 10. 14 is IEEE1394-
This is a 1394 interface having a function based on the 1995 standard and a function related to a communication protocol defined in the present embodiment. Reference numeral 16 denotes an operation unit including a keyboard, a mouse, and the like. A decoder 18 decodes compression-coded digital data (moving image data, still image data, audio data, and the like).

Reference numeral 20 denotes a display unit (display) including a display device such as a CRT display or a liquid crystal panel.
Reference numeral 22 denotes a hard disk (HD) for recording various digital data (moving image data, still image data, audio data, graphics data, text data, program data, and the like). 24 is an internal memory. Reference numeral 26 denotes an internal bus, such as a PCI bus, for connecting each processing unit inside the computer 10 to each other.

Next, the configuration of a camera-type digital video recorder (hereinafter referred to as DVCR) 28 will be described. An imaging unit (opt) 30 converts an optical image of a subject into an electric signal and converts the electric signal into an electric signal. 32 is an analog-digital (A / D) converter. An image processing unit 34 converts a digitized moving image or still image into digital image data of a predetermined format.

Reference numeral 36 denotes a compression / decompression processing unit, which has a function of decoding compression-encoded digital data (moving image data, still image data, audio data, etc.), and encodes digital image data with high efficiency (for example, , MPEG or D
Reference numeral 38 denotes a memory for temporarily storing highly efficient encoded digital image data, which has a function of performing orthogonal transformation in a predetermined image unit, quantizing, and performing variable-length encoding as in the V system.

Reference numeral 40 denotes a memory for temporarily storing digital image data that has not been encoded with high efficiency. 42 is a data selector. 44 is IEEE1394-19
This is a 1394 interface having a function conforming to the N.95 standard and a function related to a communication protocol defined in this embodiment. Reference numerals 46 and 48 denote memory control units for controlling writing and reading of the memory 38 and the memory 40.
Reference numeral 50 denotes a control unit (system controller) that controls the operation of the DVCR 28, and includes a microcomputer.

An operation unit 52 includes a remote controller, an operation panel, and the like. Reference numeral 54 denotes an electronic viewfinder (EVF). 56 is a D / A converter. 58 is a magnetic tape,
Various types of digital data (moving image data, moving image data, etc.)
Record and reproduce still image data, audio data, etc.).

Next, the configuration of the printer 60 will be described. Reference numeral 62 denotes a 1394 interface having a function based on the IEEE 1394-1995 standard and a function related to a communication protocol defined in the present embodiment. 64
Is a data selector. An operation unit 66 includes operation buttons, a touch panel, and the like. A printer controller 68 controls the operation of the printer 60.

Reference numeral 70 denotes a decoder. 72 is an internal memory. An image processing unit 74 processes text data, graphics data, and the like outside the still image data received via the 1394 interface. 76 is a driver. Reference numeral 78 denotes a printer head.

As shown in FIG. 1, a computer 10, D
Each communication device (hereinafter, referred to as a node) of the VCR 28 and the printer 60 includes 1394 interfaces 14, 44,
(Hereinafter, a network configured by a 1394 interface is connected to a 139 interface).
4 serial bus).

Each node transmits and receives various types of object data (for example, moving image data, still image data, audio data, graphics data, text data, program data, etc.) and commands by defining a predetermined communication protocol. Remote operation by data becomes possible. In the present embodiment, a communication protocol using the Asynchronous transfer method is defined.

Next, the operation of each node constituting the communication system of this embodiment will be described with reference to FIG. First,
The function and operation of each processing unit constituting the computer 10 will be described.
For example, a controller that controls transmission and reception of image data between the DVCR 28 and the printer 60, or a DV
It operates as a controller for remotely controlling the CR 28 and the printer 60.

The MPU 12 executes software recorded on the hard disk 22 and moves various data to the internal memory 24. Also, MPU12
Performs the arbitration operation of each processing unit connected by the internal bus 26, and the like.

The 1394 interface 14 is a 1394 interface.
While receiving the image data transferred on the serial bus, the image data recorded on the hard disk 22 or the internal memory 24 can be transmitted on the 1394 serial bus.

The 1394 interface 14 is
It is also possible to transmit command data for remotely controlling another node on the 94 serial bus. Furthermore, 1
The 394 interface 14 also has a function of transferring a signal transferred via the 1394 serial bus to another node.

The user selects desired software via the operation unit 16 and causes the MPU 12 to execute the software recorded on the hard disk 22. Here, information on the software is presented to the user by the display unit 20. The decoder 18 decodes the image data received from the 1394 serial bus based on the software. The decoded image data is
The information is presented to the user by the display unit 20.

Next, the function and operation of each processing unit constituting the DVCR 28 will be described. In this embodiment, DVC
The R28 operates as an image transmission device (source node) for asynchronously transferring image data based on the communication protocol of the present embodiment, for example.

The imaging section 30 converts the optical image of the subject into an electric signal k comprising a luminance signal (Y) and a color difference signal (C),
The electric signal is supplied to the A / D converter 60. A / D converter 32 digitizes the electric signal.

The image processing section 34 performs predetermined image processing on the digitized luminance signal and color difference signal, and multiplexes them. The compression / expansion processing unit 36 compresses the data amount of the digitized luminance signal and color difference signal. Here, the compression / expansion processing unit 36 may process the luminance signal and the chrominance signal in parallel using independent compression processing circuits, or may process them in a time-division manner using a common compression processing circuit. You may.

The compression / decompression processing section 36 performs shuffling processing on the compressed image data in order to make the transmission path error-resistant. This makes it possible to convert a continuous code error (ie, a burst error) into a discrete error (ie, a random error) that can be easily corrected or interpolated.

Here, when it is desired to equalize the deviation of the information amount due to the density of the image within the screen, if this processing step is brought before the compression processing, it is difficult to use variable length coding such as run length. convenient.

The compression / expansion processing section 36 adds data identification information (ID) for restoring shuffling to the compressed image data. The compression / decompression processing unit 36 adds an error correction code (ECC) to the compressed image data in order to reduce errors during recording and reproduction.

The image data compressed by the compression / expansion processing section 36 is supplied to the memory 38 and the recording / reproducing section 58. The recording / reproducing unit 58 records the compressed image data to which the ID and the ECC are added on a recording medium such as a magnetic tape. Here, the compressed image data is recorded in an independent recording area different from the audio data.

On the other hand, from the image processing section 34 to the D / A converter 5
6 is subjected to D / A conversion. EV
F54 displays the analog image signal supplied from the D / A converter 56.

The image data processed by the image processing section 34 is also supplied to the memory 40. Here, memory 4
0 stores uncompressed image data. The data selector 42 selects the memory 38 or the memory 40 based on a user's instruction, and supplies compressed image data or uncompressed image data to the 1394 interface 44.

The data selector 42 stores the image data supplied from the 1394 interface 44 in the memory 38.
Alternatively, it is supplied to the memory 40. The 1394 interface 44 converts the compressed image data or the non-compressed image data into Asyn based on the communication protocol of the embodiment described later.
Transfer to chronous.

Further, the 1394 interface 44
A control command for controlling the DVCR 28 is received via the 94 serial bus. The received control command is supplied to the control unit 50 via the data selector 42. The 1394 interface 44 returns a response to the control command.

Next, the function and operation of each processing unit constituting the printer 60 will be described. In the present embodiment, the printer 60 operates as an image receiving device (destination node) that receives and prints image data transferred asynchronously based on the communication protocol of the present embodiment, for example.

The 1394 interface 62 is a 1394 interface.
Asynchronously transferred image data and control commands are received via a serial bus. 139
The four interface 62 transmits a response to the control command.

The received image data is supplied to the decoder 70 via the data selector 64. Decoder 7
0 decodes the image data and outputs the result to the image processing unit 74. The image processing unit 74 temporarily stores the decoded image data in the memory 72.

The image processing section 74 converts the image data temporarily stored in the memory 72 into print data.
It is supplied to the printer head 78. The printer head 78 executes printing based on the control of the printer controller 68.

On the other hand, the received control command is input to the printer controller 68 via the data selector 64. The printer controller 68 performs various controls related to printing based on the control data. For example,
The paper feed by the driver 76, the position of the printer head 78, and the like are controlled.

Next, referring to FIG. 8, the 13941 of this embodiment will be described.
The configuration of the interfaces 14, 44, 62 will be described in detail. The 1394 interface is functionally composed of a plurality of layers (layers). In FIG. 8, 1
The 394 interface is IEEE 1394-1995
It is connected to a 1394 interface of another node via a communication cable 801 conforming to the standard.

The 1394 interface has one or more communication ports 802, and each communication port 802 is connected to a physical layer 803 included in a hardware unit.

In FIG. 8, the hardware section includes a physical layer 803 and a link layer 804. The physical layer 803 includes a physical / electrical interface with other nodes, detection of bus reset and associated processing, encoding / decoding of input / output signals,
Arbitrates the right to use the bus. Also, link layer 804
Performs generation of communication packets, transmission and reception of various communication packets, control of a cycle timer, and the like. Further, the link layer 804 includes an Asynchronous b described later.
Provides a function of generating, transmitting, and receiving a loadcast packet.

In FIG. 8, the firmware section
It includes a transaction layer 805 and a serial bus management 806. The transaction layer 805 manages the asynchronous transfer method, and performs various transactions (read, write,
Lock). Transaction layer 8
05 is an Asynchronous broa described later.
Provides a dcast transaction function.

Serial bus management 806
Provides functions for controlling its own node, managing its own connection state, managing its own ID information, and managing resources of the serial bus network based on the IEEE1212 CSR standard described later.

The hardware section and the firmware section shown in FIG. 8 substantially constitute a 1394 interface, and their basic configuration is based on IEEE1394-1.
An application layer 807 defined by the 995 standard and included in the software section differs depending on the application software used, and controls what object data is transferred and how.

The communication protocol of this embodiment described later is 1
The extension of the functions of the hardware section and the firmware section constituting the 394 interface provides a new transfer procedure to the software section.

Next, the basic configuration of the communication protocol specified in this embodiment will be described with reference to FIG. In FIG. 2, 300 is a controller, 302 is a source
A node 304, n (n ≧ 1) destination nodes; 306, a subunit (subunit) of the source node; 308, still image data, graphics data, text data, file data,
Object data such as program data (objectc
t).

310 is the destination node 30
4 is a first memory space inside, and has a predetermined destination offset (destination_o).
ffset # 0). 312 is the source
This is a first connection indicating a logical connection relationship (ie, connection) between the node 302 and the destination node 304. Here, the destination offset is an address that commonly specifies the memory space of the n destination nodes 304.

314 is the destination node 30
4 is an n-th memory space inside a predetermined destination offset (destination_o).
ffset # n). 316 is the source
This is an n-th connection indicating a logical connection relationship (that is, connection) between the node 302 and the destination node 304.

In this embodiment, each node stores the first memory space 310 to the n-th memory space 314 in the IEEE.
1212 CSR (Control and Stat)
usRegister Architecture) (or ISO / IEC13213: 1994)
Is managed by a 64-bit address space conforming to. The IEEE 1212 CSR standard is a standard that specifies control, management, and address allocation for a serial bus.

FIG. 6 is a diagram for explaining the address space of each node. FIG. 6A shows a logical memory space represented by a 64-bit address.
FIG. 6B shows a part of the address space shown in FIG. 6A. For example, the upper 16 bits are FFFF ₁₆ in the address space.

The first memory space 310 to the n-th memory space shown in FIG.
Memory space 314 uses a part of the memory space shown in FIG. Each of the memory spaces 310 to 314 is specified by a destination offset indicating the lower 48 bits of the address.

In FIG. 6B, for example, 00000
00000000 _{16 to} 000000003 FF ₁₆ are reserved areas, and the area where the object data 308 is actually written has the lower 48 bits of the address as FF.
FFF0000400 ₁₆ or later to become the region.

In FIG. 2, a source node 302 is a node having a function of transferring object data 308 according to a communication protocol described later, and a destination node 304 is a source node 302.
Is a node having a function of receiving the object data 308 transferred from.

The controller 300 sets a logical connection relationship (ie, connection) between the source node 302 and one or more destination nodes 304 in accordance with a communication protocol described later, and sets the logical connection relationship. This is a node that has the function of managing.

Here, the controller 300, the source node 302, and the destination node 304 may function as independent and separate nodes. or,
Controller 300 and source node 302 may function at one and the same node.

Also, controller 300 and destination node 304 may function in one and the same node. In this case, the controller 300 and the source node 302 or the destination node 30
4 is unnecessary, and the communication procedure is simplified.

In this embodiment, the controller 300, the source node 302, and the destination node 304
Will function in independent and separate nodes. For example, 1394 interface 1
4 having a controller 300
Function as The DVCR 28 having the 1394 interface 44 is connected to the source node 302.1394.
The printer 60 including the interface 62 functions as the destination node 304.

In this embodiment, as shown in FIG. 2, one or more connections can be established between the source node 302 and one or more destination nodes 304. These connections are set by one or more controllers 300 based on a communication protocol to be described later, when there is a transfer request for certain object data.

In the present embodiment, one or more destination offsets that can be used in one connection can be set. The value of the destination offset may be a preset value or a value variably set by the controller 300 or the source node 302. Note that the relationship between the connection and the destination offset is set based on a communication protocol described later.

When a plurality of destination offsets are set for one connection, a plurality of forms of data communication can be simultaneously realized by one connection. For example, by assigning different destination offsets for each form of data communication,
One-to-one, one-to-one, and N-to-N data communications can be simultaneously realized by one connection.

In this embodiment, the controller 30
The computer 10 that is 0 may operate as the destination node 304. In this case, a connection is established between one source node 302 and two destination nodes 304, and object data 308 is transferred.

In this embodiment, the computer 10
Has been described as operating as the controller 300, but the computer 10 does not necessarily need to be the controller 300. The DVCR 28 or the printer 60 may operate as the controller 300.

Next, a basic transfer procedure of the communication protocol defined in this embodiment will be described. FIG.
FIG. 4A is a sequence chart showing a procedure up to transfer of one object data. FIG.
(B) is a sequence chart showing a transfer procedure when a bus reset or a transmission error occurs during transfer of one object decoder.

In the communication protocol of this embodiment, after the controller 300 sets the above connection, one object data is transferred to one or more rAsynchrono.
The transfer is performed by “usbroadcast transaction”. Asynchronous broad
The detailed communication procedure of the cast transaction will be described with reference to FIG.

Also, Asynchronous broa
Packets used in dcast transaction (hereinafter, “asynchronous bro”)
adcast packet) is shown in FIG.
This will be described with reference to FIG. In addition, the above-mentioned Asynchronou
s broadcastcast transaction and A
synchronous broadcast pac
The “ket” is a completely new communication procedure and packet format defined in the communication protocol of the present embodiment.

A basic transfer procedure based on the communication protocol of the present embodiment will be described below with reference to FIGS. Here, FIG. 3A is a sequence chart illustrating a case where data communication is performed with one destination node 304 by one connection.

FIG. 4 is a sequence chart for explaining a case where data communication is performed with three destination nodes 304 by one connection. The controller 300 sets a connection ID for identifying a logical connection relationship (connection) between the source node 302 and one or more destinations 304.

The controller 300 notifies each node of the connection ID and sets one connection (401 in FIG. 3A and 401, 402 in FIG. 4). After the notification of the connection ID, the controller 300 instructs the source node 302 to start the transfer of the object data 308 (see FIG. 3A and 40 in FIG. 4).
3).

After receiving the instruction to start the transfer, the source node 302 sends one or more destination nodes 3
04 and negotiate with Asynchron
ous broadcast transaction
(FIG. 3A and 404 and 40 in FIG. 4).
5).

After completing the initialization, the source node 302
Is Asynchronous broadcast
Transaction is executed, and object data 308 composed of one or more segment data is sequentially broadcast (FIGS. 3A and 406 to 40 in FIG. 4).
9).

Here, a transfer model of object data in this embodiment will be described with reference to FIG. In FIG. 7, the object data is, for example, still image data having a data size of 128 Kbytes.

The source node 302 stores the object data 308 in accordance with the receiving capability of each destination node 3041 recognized in the initial setting, for example, by 5 bytes.
00 segment data (1 segment data is 25
6 bytes).

Here, the data size of one segment data is variably set by the source node 302 according to the size of the internal buffer of each destination node 304. FIG. 7 shows a case where an internal buffer having the same data size as the object data 308 is secured.

Further, the source node 302 stores one or more segment data in at least one
onous broadcast cast transacti
Transfer using on.

[0094] In FIG. 7, one segment data is stored in one Asynchronous broadcast.
Transfer using transaction.

After all segment data has been transferred, the source node 302
4 is terminated (FIG. 3A, 41 in FIG. 4).
0, 411).

Next, the operation of the controller 300 will be described in detail with reference to FIGS. The controller 300 includes a source node 302 and one or more destination nodes 304 selected by a user.
In response to this, a packet for setting a connection (hereinafter, a connection setting packet) is sent to Asynchron.
ous transfer (401 in FIG. 3A, 401, 40 in FIG. 4)
2).

The payload of this packet includes a source
A connection ID for identifying a connection between the node 302 and the destination node 304 is stored. Here, the connection between the source node 302 and one or more destination nodes 304 is based on the connection ID already set for the source node 302 and each destination node 3.
The setting is made by the controller 300 on the basis of the connection ID already set for the server 04.

Next, the controller 300 sends a transmission command packet (trans) to the source node 302.
action command packet) as
ynchronous transfer (FIG. 3A, 4 in FIG. 4).
03). The source node 302 that has received the transmission command packet performs an initial setting using the connection ID notified from the controller 300, and performs Asynchronization.
nousbroadcast transactio
n (FIGS. 3A and 404 to 409 in FIG. 4).

This Asynchronous broa
By dcast transaction, the source
The node 302 can sequentially transfer object data 308 including one or more segment data. In the communication protocol of the present embodiment, the controller 300 provides a function of managing connection and non-connection of a connection.

Accordingly, the transfer of the object data 308 after the connection is set is performed by the source node 302.
Is executed by negotiation between the destination node 304 and the destination node 304.

A series of Asynchronous bro
After the adcast transaction ends,
The source node 302 has an Asynchronous broadcast p indicating the segment end.
packet (hereinafter, segment end pack)
et) (FIG. 3 (a), 4 in FIG. 4).
10).

The controller 300 controls the source node 3
After receiving the segment endpacket from No. 02, the connection is released and the data transfer ends (411 in FIG. 3A, 411 in FIG. 4).

Here, segment end pac
Since the "ket" is broadcast, the contents of the packet can be detected at the destination node 304. Therefore, the destination node 304 itself, instead of the controller 300, may be configured to release the connection with the source node 302.

Next, the operation of the tooth node 302 will be described in detail with reference to FIGS. Source node 302 that has received a connection setting packet and a transmission command packet from controller 300
Is an Asynchronous b for requesting each destination node 304 to transfer data.
loadcast packet (hereinafter, sendre
quest packet) (FIG. 3 (a),
404 in FIG. 4).

Here, the sendrequest pac
ket stores the object data 308 in the Asynchr
onous broadcast cast transacti
This is a request packet for obtaining necessary initial information before executing on. In this packet, the connection ID specified by the controller 300 is written.

The destination node 304 determines that s
Asynchronous br indicating that it is a response corresponding to endrequest packet
oadcast packet (hereinafter, ackresp)
once packet) (FIG. 3A, 405 in FIG. 4). Here, ackrespo
send request for the ns packet
The same connection ID as the packet is stored.

Therefore, the source node 302 confirms the connection ID of the received packet to determine which connection the ack repos transmitted through.
nse packet can be identified.

Here, ack response pa
The ticket stores the size of an internal buffer that can be secured by each destination node 304 and an offset address that specifies a predetermined memory space.

Ack response packet
, The source node 302 sets a destination offset that specifies the memory space of each destination node 304 in common, and
onous broadcast cast transacti
Start on.

Here, the destination offset is the ack r of each destination node 304.
This is set using the offset address included in the responsepacket. In this embodiment, Asy
nchronous broadcast trans
destination used in the action
Set the offset to the ack response packe
Although the setting is performed using the offset address included in t, the present invention is not limited to this.

For example, the controller 300 may have a function of managing the destination offset used by each connection, and may be configured to set the destination offset together with the connection ID. In this case, the destination offset corresponding to each connection is notified from the controller 300 to the source node 302.

Next, the source node 302
synchronous broadcast pac
ket is written in the memory space indicated by the above-mentioned destination offset (FIG. 3A, 4 in FIG. 4).
06).

This packet stores the connection ID and the sequence number of the segment data.
First Asynchronous Broadcast
After sending the packet, the source node 302
Waits for a response packet from the destination node 304. A response packet storing the connection ID and the sequence number is transmitted from the destination node 304 to the Asynchron.
It is sent in the format of ous broadcastcast packet.

After receiving this response packet, the source node 302 increments the sequence number and sets the Async including the next segment data.
Then, the broadcast packet is transferred (407 in FIG. 3A and FIG. 4).

By repeating this procedure, the source node 3
02 is Asynchronous broadca
The st transaction is performed (FIG. 3A, 408 to 409 in FIG. 4). Destination node 3
The maximum time for waiting for a response from the server 04 is predetermined, and if a response does not return after the time, the same data is retransmitted using the same sequence number.

When a response packet requesting retransmission is transferred from the destination node 304, the source node 302 can broadcast the data of the designated sequence number again.

[0117] All of the object data 308
nchronous broadcast trans
After the action, the source node 302
4 and the data transfer is completed (41 in FIG. 3A and FIG. 4).
0, 411).

Here, as described above, the source node 302 divides the object data 308 into one or more segment data as necessary (Segmentation
n). The above-mentioned response packet is obtained by associating each segment data with Asynchronous broadca.
This will occur with the case of st transaction. In this embodiment, the transfer of one segment data is performed by one Asynchronous broadcast.
This is performed by ast transaction. The destination node 304 has a buffer having a capacity indicated by the buffer size described above.

In the embodiment described above, Asynchronous broadcast of one segment data is performed.
Although it is defined that a response packet is always transmitted in accordance with the transaction, the present invention is not limited to this. After the data buffer of the destination node 304 is filled with a plurality of continuous segment data, the destination node 304 may transmit the response packet.

Next, the operation of the destination node 304 will be described in detail with reference to FIGS. The destination node 304, which has received the connection setting packet from the controller 300,
Send request from source node 302
Wait for packet (FIG. 3A, 40 in FIG. 4)
4).

Send request packet
The destination node 304 that has received the packet confirms the connection ID written in the packet and the connection ID notified from the controller, and determines whether or not this packet is a packet from the source node 302.

Send r from source node 302
After receiving the request packet, each destination node 304 writes the connection ID, the size of the internal buffer that can be secured, and the offset address that specifies the predetermined memory space.
Broadcast the pose packet (405 in FIG. 3A and FIG. 4).

As transferred from source node 302
ynchronous broadcast pack
After writing et into the memory space, the destination node 304 checks the connection ID of the packet.

The connection ID included in the packet
Broadcasts a response packet storing the connection ID and the sequence number included in the packet (406 in FIG. 3A and 406 to 409 in FIG. 4).

In this case, the segment data included in the received packet is stored in the internal buffer. Here, if the connection ID included in the received packet is different from its own connection ID, the destination node 304 discards the received packet.

Also, destination node 304
When detecting a mismatch in the sequence number of a received packet, it can also send a response packet indicating a retransmission request. In that case, the destination node 304 notifies the source node 302 of the sequence number requesting retransmission.

All Asynchronous bros
When you finish the adcast transaction,
Segment end p from source node 302
The packet is broadcast. Upon receiving this packet, the destination node 304 ends the data transfer process (FIG. 3A, 41 in FIG. 4).
0).

After receiving the segment end packet, the destination node 304
A response packet indicating that the end-end packet has been normally received is broadcast (411 in FIG. 3A and FIG. 4).

As described above, the communication system of the present embodiment can solve the inconvenience of the conventional communication system. Further, even in data transfer that does not require real-time properties, data can be transferred easily and at high speed.

In this embodiment, after the controller 300 sets the connection, the transfer processing of the object data is not controlled by the controller 300 and the source node 300 and each of the destination nodes 30 are controlled.
4 is executed. Thus, it is possible to reduce the load on the controller 300 and provide a simple communication protocol that does not take complicated communication procedures.

In this embodiment, the destination
The node 304 is connected to each Asynchronous bro
It is configured to always return a response to adcast transaction. This makes it possible to provide a communication protocol that can reliably transfer data that does not require real-time properties.

In order to realize more reliable data transfer, when data transfer is interrupted due to a bus reset or some kind of transmission error, it is necessary to restart the data transfer promptly without losing data. .

Hereinafter, the restart procedure defined by the communication protocol of this embodiment will be described with reference to FIG. For example, Asynchronous of sequence number i
When a bus reset occurs after receiving the broadcast packet, each node suspends the transfer processing and executes initialization of the bus, recognition of the connection configuration, setting of the node ID, and the like in accordance with the procedure defined by the IEEE 1394-1995 standard. (420 and 421 in FIG. 3B).

After the rebuilding of the bus is completed, each destination node 304 issues a restart request packet (resease) storing the connection ID and the sequence number i.
ndrequest packet) (422 in FIG. 3B).

Asynchronous broadc
If restart of ast transacticm is possible,
The source node 302 receives the received resend re
Check the connection ID of the questpacket,
Ack response storing this connection ID
Broadcast the se packet (Fig. 3
(423 of (b)).

Thereafter, the source node 302 sequentially broadcasts the segment data subsequent to the sequence number requested by the received request request packet, that is, the segment data starting with the sequence number (i + 1) (4 in FIG. 3B).
24).

By the above procedure, the controller 300,
Source node 302, destination node 3
04, even if the data transfer is interrupted without considering each node ID,
And it can be reliably restarted. Further, as described above, the present embodiment has an effect that the control procedure of the controller 300 can be simplified even when the data transfer is interrupted.

Next, Asynchronous broadcast specified in this embodiment with reference to FIG.
The configuration of the packet will be described. Asynchr
The onroadcast packet is, for example, 1 Quadlet (4 bytes = 32 bits)
s) is a data packet.

First, the packet header (packet)
The configuration of the (header) 521 will be described. In FIG. 5, a field 501 (16 bits) has a destination
nation_ID, and indicates the node ID of the destination (ie, destination node 304). In the communication protocol of the present embodiment, the Asynchronous broadcast tr of the object data 308
In order to realize the action, the value of this field is set to the broadcast ID (that is, “FFFF ₁₆ ”).
And

A field 502 (6 bits) indicates a transaction label (tl) field, and is a tag unique to each transaction. Field 503
(2 bits) indicates a retry (rt) code, and specifies whether the packet attempts a retry.

The field 504 (4 bits) indicates a transaction code (tcode). tcode
Specifies the format of the packet and the type of transaction that must be performed.

In this embodiment, the value of this field is set to, for example, “0001 ₂ ”, and the process of writing the data block 522 of this packet into the memory space indicated by the destination_offset field 507 (ie,
Write transaction).

A field 505 (4 bits) indicates a priority (pri) and specifies a priority. In this embodiment, the value of this field is “0000 ₂ ”. The field 506 (16 bits) is a source
e_ID, indicating the sender (ie, source node 30).
2) indicates the node ID.

The field 507 (48 bits) contains d
This indicates the destination_offset, and commonly specifies the lower 48 bits of the address space of each destination node 304. Where desti
As the nation_offset, the same value may be set for all connections, or a different value may be set for each connection. However, it is better to set different values for Asynchronous br from multiple connections.
The efficiency is high because the oadcast packets can be processed in parallel.

The hood 508 (16 bits) is obtained by
data_length indicates the length of a data field described later in bytes. Field 509 (16
bits) indicates extended_tcode.
In the present embodiment, the value of this field is “0000 ₂ ”.

Field 510 (32 bits) contains h
field 501, which indicates the header_CRC.
509 are stored. Next, a data block 522 is provided.
Will be described. In the present embodiment, the data block 522 includes header information (package).
t information 523 and a data field 524.

[0147] Header information 523 includes
Logical connection relationship between each node (that is, connection)
Is stored.
The data field 524 is a variable length field and stores the above-described segment data. here,
If the segment data stored in the data field 524 is not a multiple of quadred, “0” is filled in the portion less than quadred.

The field 511 (16 bits) contains c
connection_ID indicates the connection ID of the present embodiment. The 1394 interface of this embodiment identifies a connection set between the source node 302 and one or more destination nodes 304 based on the connection ID stored in this field. In the present embodiment, it is possible to establish 2 ¹⁶ × (the number of nodes) connections. This allows
A plurality of connections can be set until the total amount of communication bandwidth used by each connection reaches the capacity of the transmission path.

The field 512 (8 bits) contains pr
otocol_type, and indicates a communication procedure (that is, a type of communication protocol) based on the header information 523. When indicating the communication protocol of the present embodiment, the value of this field is, for example, “01 ₁₆ ”.

The field 513 (8 bits) contains co
Control_flags indicates predetermined control data for controlling the communication procedure of the communication protocol of the present embodiment. In this embodiment, the most significant bit of this field is set to, for example, a retransmission request (resend requests).
t) Set a flag. Therefore, when the value of the most significant bit of this field is “1”, it indicates that a retransmission request based on the communication protocol of this embodiment has occurred.

The field 514 (16 bits) contains s
Indicates a sequence_number, and sets a continuous value (ie, sequence number) for a packet transferred based on a specific connection ID (connection ID specified in the field 511).

According to the sequence number, the destination node 304 sequentially transmits the Asynchron.
ous broadcast transaction
The continuity of the segment data to be performed can be monitored. If a mismatch occurs, the destination node 304 can also request a retransmission based on this sequence number. Field 515 (16 bits)
Indicates reconfirmation_number.

In this embodiment, this field is significant only when the value of the retransmission request flag is 1. For example, when the value of the above-mentioned retransmission request flag is “1”, the sequence number of the packet for which retransmission is requested is set in this field.

Field 516 (16 bits) contains b
Indicates buffer_size. In this field, the buffer size of the destination node 304 is set.

Field 517 (48 bits) contains o
Indicates ffset address. In this field, the lower 48 bits of the address space of the destination node 304 are stored. This allows
One of the first memory space 310 to the n-th memory space 314 shown in FIG. 2 is designated.

The field 518 (32 bits) contains d
Indicates the data_CRC, and stores an error detection code for the fields 511 to 517 (including the header information 523 and the data field 524), like the header_CRC. ,

Next, a communication procedure defined in the communication protocol of this embodiment will be described in detail with reference to FIGS. In this embodiment, in particular, the source node 302
A series of asynchronous broadcasts between the server and the destination node 304
A procedure for terminating the transaction during the transfer period will be described.

FIG. 9 is a diagram showing an example in which the transfer processing is simply stopped at the source node 302 and the destination node 304. In FIG. 9, for simplicity of description, the Asynchron between one source node 302 and one destination node 304 is described.
ous broadcast transaction
Will be described, but the same processing can be performed with the N destination nodes 304.

In FIG. 9, the destination node 304 can cause the source node 302 to stop data transfer by not sending the above-mentioned response packet.

In FIG. 9, the destination node 3
04 is, for example, the n-th Asynchronous b
FIG. 9 shows a case where a response packet is not transmitted for a loadcast transaction (FIG. 9).
901).

In this case, if the response packet does not return from the destination node 304 within a predetermined time (response time-out 901), the source node 302
synchronous broadcast pac
The segment data having the same sequence number as that of “ket” is automatically retransmitted (903 in FIG. 9).

If a response packet has not been received even after repeating the above procedure a predetermined number of times (904 in FIG. 9), the source node 302 stops the data transfer by the destination node 304 halfway. Then, the abort packet is broadcast (905 in FIG. 9). Here, the abort packet is a series of Asynchronous br between the source node 302 and the destination node 304.
This is a packet for stopping the oadcasttransaction.

With this abort packet, the controller 300 and the destination node 304 are made aware of the end of the transfer geography, and the source node 200
Ends the data transfer. At this time, the controller 30
0 disconnects the connection corresponding to this abort packet.

According to such a procedure, according to the communication protocol of this embodiment, the data transfer can be easily stopped without requiring the destination node 304 to perform special processing, and the connection to the controller 300 is disconnected. Can be done.

Further, as shown in FIG.
00, any one of the source node 302 and the destination node 304 requests the stop of the transfer processing.
By broadcasting an ort packet,
A series of Asynchronous Broadcast
It is also possible to configure such that the transaction is terminated halfway.

FIG. 10A shows an example in which the source node 302 sends a stop request. FIG.
FIG. 11B is a diagram illustrating an example in which the destination node 304 sends a stop request.

FIG. 10C shows the controller 300.
FIG. 9 is a diagram showing an example of sending a stop request. In FIG. 10, for simplicity of description, one source node 3
02 and one destination node 304 Asynchronous broadcastcast tr
A description will be given of an action. However, the same processing can be performed with N destination nodes 304.

Asynchronous broadc
A node that wants to end the ast transaction halfway broadcasts an abort packet during a data transfer period. The source that received the packet
Node 302 or destination node 304
Stop the data transfer in accordance with a predetermined procedure, respectively, and the controller 300 disconnects the connection.

In FIG. 10A, for example, the n-th Asy
nchronous broadcasttransa
After the end of the action, the source node 302
rt packet is broadcast (FIG. 1)
0 of 1001).

Also, in FIG. 10B, for example, the n-th A
Synchronous Broadcast Tra
It shows a case where the destination node 302 broadcasts an abort packet after the end of nsaction (1002 in FIG. 10). In FIG. 10C, for example, the n-th Asynchronous bro
A case where the controller 300 broadcasts an abort packet after the end of the adcast transaction (1003 in FIG. 10).

According to such a procedure, the controller 30
0, the source node 302, and the destination node 304 can reliably stop data transfer by a simple procedure and disconnect the connection.

As described above, in the above embodiment,
IE is a logical connection that does not depend on the physical connection mode.
It can be built in a bus type network such as the EE1394-1995 standard.

In this embodiment, IEEE1394-1
In a communication system conforming to the 995 standard, real-time properties are not required, but object data (for example, still image data, graphics data, text data, file data, program data, etc.) that requires a relatively large amount of data but requires reliability. ) Can be provided into a completely new communication protocol that divides the data into one or more segment data and continuously transfers them.

In this embodiment, IEEE1394-1 is used.
In a communication system conforming to the 995 standard, it is also possible to provide a completely new communication protocol for realizing data communication between a plurality of devices by using a communication method for asynchronously broadcasting data.

In this embodiment, IEEE1394-1 is used.
A plurality of continuous data can be reliably transferred without using the Isochronous transfer method of the 995 standard. Also, one object data can be divided into a plurality of data and transferred reliably.

Further, in this embodiment, by managing communication between a plurality of devices by two connections, it is possible to simultaneously perform a large number of communications that do not use much communication bandwidth. Also, in this embodiment, even when data transfer is interrupted due to a bus reset or an error during transmission, it is possible to know which segment of data has been lost, and to resume transfer without taking a very complicated communication procedure. can do.

(Other Embodiments) The augmentation protocol described in each of the above embodiments and various processing operations necessary for realizing it can be realized by software. For example, a storage medium storing a program code for realizing the functions of the above-described embodiments may be used as a control unit (for example, the MPU 12, the system controller 50, and the printer controller 68 of FIG. ).

Then, the control unit reads out the program code stored in the storage medium, and controls the operation of the communication system or the apparatus itself so as to realize the function of each embodiment according to the program code. Even so, the above-described embodiment can be realized.

Further, a storage medium storing a program code for realizing the functions of the above-described embodiments is supplied to 1394 interfaces 14, 44, 62 provided in each device, and the 1394 interfaces 14, 44, 62 A control unit for controlling the operation (for example, serial bus management 806 in FIG. 8) is configured to control the processing operation so as to realize the function of each embodiment according to the program code stored in the recording medium. You may.

In this case, the program code itself read from the above-described storage medium realizes the functions of each embodiment, and the program code itself and means for supplying the program code to the control unit (for example, , The storage medium itself) constitutes the present invention. As a storage medium for storing such a program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk,
CD-ROM, magnetic tape, nonvolatile memory card,
A ROM or the like can be used.

The program code read from the storage medium described above is stored in the OS running on the control unit.
It goes without saying that the present invention includes a case where the functions of the respective embodiments are realized in cooperation with an (operating system) or various application software.

Further, after storing the program code read from the storage medium in the memory provided in the function expansion unit connected to the control unit, the control unit provided in the function expansion unit stores the program code in the memory. Perform some or all of the actual processing according to the stored program code,
It goes without saying that a case where the functions of the respective embodiments are realized by the processing is also included in the present invention.

The present invention can be embodied in various other forms without departing from the spirit or main characteristics. For example, in the present embodiment, IEEE1394-19
Although the communication protocol applicable to the network conforming to the 95 standard has been described, the present invention is not limited to this.

The communication protocol of this embodiment is IEEE1
The present invention can also be applied to a serial bus network such as the 394-1995 standard or a network that can virtually configure a bus network. Therefore, each of the above-described embodiments is merely an example in all aspects, and should not be construed as limiting.

The scope of the present invention is defined by the appended claims, and is not limited by the specification. Furthermore, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

[0186]

According to the present invention, as described above, according to the present invention, a logical connection relationship independent of a physical connection form can be constructed in a bus type network such as the IEEE1394-1995 standard. .

According to another feature of the present invention, the IEEE
In a communication system conforming to the E1394-1995 standard, real-time properties are not required, but object data having a relatively large data amount requiring reliability, such as still image data, graphics data, text data, file data, Program data etc.
It is possible to provide a completely new communication protocol in which the data is divided into the segment data and transferred continuously.

According to another feature of the present invention, I
In a communication system conforming to the IEEE 1394-1995 standard, a completely new communication protocol for realizing data communication between a plurality of devices using a communication method of asynchronously broadcasting data can be provided.

Also, according to another feature of the present invention, I
Isochronou of the IEEE 1394-1995 standard
A plurality of continuous data can be reliably transferred without using the s transfer method. Also, one object data can be divided into a plurality of data and transferred reliably.

Further, according to another feature of the present invention, by managing communication between a plurality of devices by using two connections, it is possible to simultaneously perform a large number of communication using a small communication band.

Further, even when data transfer is interrupted due to a bus reset or transmission error, it is possible to know which segment of data has been lost, and to restart the transfer without taking a very complicated communication procedure. Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a communication system according to an embodiment;

FIG. 2 is a conceptual diagram illustrating a basic configuration of a communication protocol according to the embodiment.

FIG. 3 is a sequence chart illustrating a basic communication procedure of a communication protocol according to the embodiment.

FIG. 4 is a sequence chart illustrating a basic communication procedure of a communication protocol according to the present embodiment.

FIG. 5 shows an Asynchronous bro of this embodiment.
It is a figure which shows the structure of an adcast packet.

FIG. 6 is a diagram illustrating an address space of each node.

FIG. 7 is a diagram illustrating a transfer model of object data.

FIG. 8 is a diagram illustrating a configuration of a 1394 interface according to the present embodiment.

FIG. 9 is a sequence chart for explaining in detail a communication procedure of a communication protocol in the embodiment.

FIG. 10 is a sequence chart for explaining in detail a communication procedure of a communication protocol in the embodiment.

FIG. 11 is a diagram illustrating a conventional system.

[Explanation of symbols]

 Reference Signs List 10 computer 12 arithmetic processing unit (MPU) 14 1394 interface 16 operation unit 18 decoder 20 display unit (display) 22 hard disk (HD) 24 internal memory 26 internal bus 28 camera digital video recorder 30 imaging unit (opt) 32 analog-digital (A / D) converter 34 Image processing unit 36 Compression / decompression processing unit 38 Memory 40 Memory 42 Data selector 44 Interface 50 Control unit (system controller) 52 Operation unit 54 Electronic viewfinder (EVF) 56 D / A converter 58 Recording / playback unit 60 Printer 62 1394 interface 64 Data selector 66 Operation unit 68 Printer controller 70 Decoder 72 Internal memory 74 Image processing unit 76 Driver 78 Printer head

Continuation of front page (72) Inventor Mitsuo Niida Canon Inc. 3- 30-2 Shimomaruko, Ota-ku, Tokyo

Claims (67)

[Claims] 1. The method of claim 1, wherein at least one asynchronous communication is used.
A source node for transferring data comprising one or more segments, one or more destination nodes for receiving the data transferred from the source node, and between the source node and the one or more destination nodes. A data communication system, comprising: a controller that sets a logical connection relationship, wherein at least one of the source node, the destination node, and the controller stops transferring the data. 2. The data processing method according to claim 1, wherein the source node transfers the data based on a logical connection relationship with the one or more destination nodes.
A data communication system according to claim 1. 3. The at least one source node,
3. The data communication system according to claim 1, wherein the asynchronous communication is performed continuously. 4. The system of claim 1, wherein the one or more destination nodes receive the data based on a logical connection relationship with the source node.
The data communication system according to any one of claims 1 to 3. 5. The data according to claim 1, wherein the one or more destination nodes return a response to the data transferred using the asynchronous communication. Communications system. 6. The data communication system according to claim 5, wherein the destination node stops transferring the data by not returning the response. 7. The at least one of the source node, the destination node, and the controller,
6. The system according to claim 1, wherein the stop of the data transfer is notified to another node using the logical connection relationship.
The data communication system according to claim 1. 8. The controller as claimed in claim 1, wherein the controller is configured to establish a connection between the source node and the one or more destination nodes.
The data communication system according to any one of claims 1 to 7, wherein one or more logical connection relationships can be set. 9. The data communication system according to claim 1, wherein the controller releases the logical connection after the transfer of the data is stopped. 10. The logical connection relationship is released by the controller or the destination node after the transfer of the data.
The data communication system according to claim 1. 11. The data communication system according to claim 1, wherein initialization required for transferring the data is performed between the source node and the one or more destination nodes. The data communication system according to claim 1. 12. The data communication system according to claim 11, wherein the controller can set a part of initial information set in the initial setting. 13. The data communication system according to claim 11, wherein the one or more destination nodes notify the source node of initial information required for the initial setting. 14. The data communication system according to claim 11, wherein said source node performs said initial setting using initial information notified from said one or more destination nodes. 15. The initialization according to claim 11, wherein at least one of a destination address and a size of a reception buffer for commonly specifying a memory space of the one or more destination nodes is set. A data communication system according to claim 1. 16. The data communication system according to claim 1, wherein the source node broadcasts the data using the asynchronous communication. 17. The data processing method according to claim 1, wherein the source node writes the data in a common memory space of the one or more destination nodes using the asynchronous communication. A data communication system according to item 9. 18. The data according to claim 1, wherein the one or more destination nodes store the data in a common memory space of each destination node. Communications system. 19. The method according to claim 19, wherein the asynchronous transfer is based on IEEE 1394.
The data communication system according to any one of claims 1 to 18, wherein the data communication system conforms to an Asynchronous transfer method of -1995 standard. 20. The data communication system according to claim 1, wherein the data communication system is a bus network. 21. The data communication system according to claim 21, wherein
The data communication system according to any one of claims 1 to 20, wherein the network is based on a 1394-1995 standard. 22. The data processing system according to claim 1, wherein the data comprising one or more segments is at least one of still image data, graphic data, text data, file data, and program data. 2. The data communication system according to claim 1. 23. Establishing a logical connection relationship between a source node and one or more destination nodes; and transmitting data comprising one or more segments using at least one asynchronous communication. Transferring to the one or more destination nodes, receiving the data transferred using the asynchronous communication using the logical connection relationship, at least one of the source node, the destination node, and the controller Stopping the transfer of the data by one of the steps. 24. A source node for transferring data consisting of one or more segments using at least one broadcast communication based on a logical connection relationship, and A data communication system, comprising: one or more destination nodes for receiving the transferred data, wherein the source node or the one or more destination nodes stop transferring the data. 25. transferring the data comprising one or more segments to one or more destination nodes using at least one broadcast communication based on the logical connection relationship; Receiving the data transferred from the source node, and stopping the transfer of the data by the source node or the one or more destination nodes based on the data communication method. 26. A communication system comprising: means for packetizing data comprising one or more segments into at least one communication packet; and a logical connection established between one or more destination nodes. Means for asynchronously transferring packets, wherein the asynchronous transfer of the at least one communication packet can be stopped. 27. Packetizing data consisting of one or more segments into at least one communication packet, and using the logical connection relationship established with one or more destination nodes. A data communication method, comprising: performing a step of asynchronously transferring a packet; and a step of stopping the asynchronous transfer of the at least one communication packet. 28. A means for receiving at least one communication packet asynchronously transferred using a logical connection relationship established with a source node, and sharing data included in the communication packet with another device. Means for writing to the memory space of claim 1, wherein the asynchronous transfer of the at least one communication packet can be stopped. 29. A step of receiving at least one communication packet asynchronously transferred using a logical connection relationship established with a source node, and sharing data included in the communication packet with another device. A data communication method, and a step of stopping the asynchronous transfer of the at least one communication packet. 30. A means for setting a logical connection relationship between a source node and one or more destination nodes, and a connection I for identifying the logical connection relationship.
Means for notifying D to the source node and the one or more destination nodes and suspending data transfer based on the logical connection relationship. 31. A step of establishing a logical connection between a source node and one or more destination nodes; and a connection I for identifying said logical connection.
A data communication method, comprising: notifying the source node and the one or more destination nodes of D, and stopping the data transfer based on the logical connection relationship. 32. A communication system comprising: means for packetizing data comprising one or more segments into at least one communication packet; and a logical connection established between at least one destination node. Means for asynchronously transferring packets, wherein the asynchronous transfer of the at least one communication packet can be stopped. 33. A means for receiving at least one communication packet asynchronously transferred using a logical connection relationship established with a source node, and sharing data included in the communication packet with another device. Means for writing to said memory space, wherein the asynchronous transfer of said at least one communication packet can be stopped. 34. A means for setting a logical connection between a source node and one or more destination nodes, and a connection I for identifying the logical connection.
Means for notifying D to the source node and the one or more destination nodes, and stopping data transfer based on the logical connection relationship. 35. A data communication system for performing communication using a logical connection relationship set between a transmitting device for transmitting information data and a receiving device for receiving the information data, the data communication system comprising: A data communication system characterized in that the transmitting device or the receiving device opens a simple connection relationship. 36. The data communication system includes a management device having a function of managing the logical connection relationship,
The data communication system according to claim 35, wherein the management device logically connects the transmitting device and the receiving device. 37. The data communication system according to claim 36, wherein the management device notifies the transmitting device and the receiving device of information for identifying the logical connection relationship. 38. The data communication system according to claim 35, wherein the transmission of the information data is interrupted when the logical connection relationship is released. 39. The logical device according to claim 35, wherein the logical connection relationship is released when the receiving device does not transmit data indicating that the information data has been received. A data communication system according to claim 1. 40. The logical connection according to claim 35, wherein the logical connection is released by the transmitting device or the receiving device requesting release of the logical connection. 2. The data communication system according to claim 1. 41. The data communication system according to claim 35, wherein said information data is broadcast. 42. The information data is based on IEEE1394
The data communication system according to any one of claims 35 to 41, wherein the data is transferred using an Asynchronous transfer method conforming to a standard. 43. The information processing apparatus according to claim 35, wherein the information data is transmitted using a communication packet including information for identifying the logical connection relationship. Data communication system. 44. The data communication system according to claim 36, wherein said management device can set one or more logical connection relationships between a pair of transmitting device and receiving device. 45. The management device includes one transmission device and one transmission device.
37. The data communication system according to claim 36, wherein one or more logical connection relationships can be set between one or more receiving devices. 46. The management device includes a plurality of transmission devices and one
37. The data communication system according to claim 36, wherein one or more logical connection relationships can be set between two receiving devices. 47. The data communication system according to claim 36, wherein the management device can set one or more logical connection relationships between a plurality of transmitting devices and a plurality of receiving devices. 48. The data communication system according to claim 35, wherein said logical connection relationship specifies a predetermined memory space of said receiving device. 49. The data communication system according to claim 48, wherein a different area is designated in said memory space for each of said logical connection relationships. 50. The logical device according to claim 36, wherein the logical connection is released by the management device requesting release of the logical connection. Data communication system. 51. In response to the connection request from the transmitting device, the receiving device transmits a reception buffer size, an offset address specifying a predetermined memory space, a sequential number indicating a data start pointer, and information indicating preparation completion. 36. The method according to claim 35, further comprising returning a matching packet.
50. The data communication system according to any one of 50. 52. The data communication system according to claim 35, wherein said receiving device is provided with a bit indicating that data has been received normally. 53. The transmission device according to claim 34, wherein the transmission device measures a response from the reception device for a predetermined period, and retransmits the information data according to the period.
The data communication system according to claim 1. 54. The transmission device according to claim 53, wherein the transmission device releases the logical connection between the transmission device and the reception device after repeating the retransmission of the information data a predetermined number of times. Data communication system. 55. A data communication system using a communication system for continuously and asynchronously transmitting a plurality of communication packets, wherein when a response from a device receiving the information has not passed for a predetermined period of time, A data communication system wherein transmission of information is stopped. 56. The data communication system according to claim 55, wherein said communication system broadcasts said communication packet. 57. A data communication system constituted by a plurality of devices, wherein a communication between a plurality of different devices is identified by a plurality of different ID information, and the communication is terminated by not responding to the communication. A data communication system, comprising: 58. The data communication system according to claim 57, wherein said ID information includes a logical connection relationship between said plurality of different devices. 59. A data communication device connectable to a communication system constituted by a plurality of devices, comprising: a logical connection between a transmitting device for transmitting information data and an information device for receiving the information data. A data communication device comprising: communication means for performing communication using a relationship; and control means for controlling not to transmit a response to reception of the information data in order to release the logical connection relationship. . 60. A data communication device connectable to a communication system constituted by a plurality of devices, comprising: a logical connection between a transmitting device for transmitting information data and an information device for receiving the information data. Communication means for performing communication using the relationship, and control means for controlling the logical connection relation to be released in accordance with a waiting time for a response to the reception of the information data. apparatus. 61. A data communication system comprising a transmitting device for transmitting information data, a receiving device for receiving the information data, and a management device for managing communication of the information data. The receiving device and the management device are
After setting a logical connection relationship between the transmission device and the reception device, any one of the transmission device, the reception device, and the management device releases the logical connection relationship. Data communication system. 62. A data communication system using a communication system for continuously and asynchronously transmitting a plurality of communication packets, wherein information transmitted by the communication system is stored in the same area of a memory space of the plurality of devices. And a retransmission of the information according to a waiting time for a response to the reception of the information. 63. A data communication method applicable to a data communication system for performing communication by using a logical connection relationship between a transmitting device for transmitting information data and a receiving device for receiving the information data. And releasing the logical connection relationship to the transmitting device or the receiving device. 64. A data communication method using a communication method for continuously and asynchronously transmitting a plurality of communication packets, wherein a response from a device receiving the information has not passed for a predetermined period of time. A data communication method characterized by stopping transmission of data. 65. A data communication method applicable to a data communication system constituted by a plurality of devices, wherein a communication between a plurality of different devices is determined by a plurality of different ID information, and a response to the communication is not performed. A data communication method characterized by terminating the communication. 66. A data communication method applicable to a data communication system including a transmitting device for transmitting information data, a receiving device for receiving the information data, and a management device for managing communication of the information data. Controlling the transmitting device, the receiving device, and the management device so as to set a logical connection relationship between the transmitting device and the receiving device, and then releasing the logical connection relationship. And controlling one of the transmitting device, the receiving device, and the management device. 67. A data communication method using a communication system for continuously and asynchronously transmitting a plurality of communication packets, wherein information transmitted by the communication system is stored in the same area of a memory space of the plurality of devices. And retransmitting the information according to a waiting time for a response to the reception of the information.