JP2005123739A - COMMUNICATION SYSTEM, TERMINAL DEVICE, COMMUNICATION SYSTEM CONTROL METHOD, RECORDING MEDIUM, AND PROGRAM - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication system capable of transferring data at a high speed with a simple connection procedure and warranting certainty of data transfer. <P>SOLUTION: A command to establish an asynchronous connection between units is extended to add a field for designating a sub unit plug in the unit to the extended field so that the single command can carry out the asynchronous connection between the units and a connection between the sub unit plug in the unit and a port provided in the unit or execute their interruptions at the same time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a communication system, a terminal device, a communication system control method, a recording medium, and a program, and in particular, can communicate with a plurality of electronic devices via a data communication bus capable of communicating by mixing control signals and data. Therefore, it is suitable for use in a communication system that performs data communication between devices.

  Among peripheral devices of personal computers (hereinafter referred to as “PCs”), hard disks and printers are frequently used, and digital interfaces (hereinafter referred to as “digital I / Fs”) that are typical general-purpose interfaces for small computers. Data communication is performed by connecting to a PC using a SCSI (Small Computer System Interface) or the like. An image recording / reproducing apparatus such as a digital camera or a digital video camera is also one of peripheral devices capable of data communication with a PC. In recent years, images (still images and moving images) taken by the image recording / reproducing apparatus are used. Has been developed to capture and store images on a hard disk, store them on a hard disk, or edit them using a PC, and then print them in color on a printer. doing.

  As described above, when the captured image data is output from the PC to a printer or hard disk, data communication is performed via the digital I / F such as the SCSI, so that the amount of data is as large as the image data. In order to send information, a digital I / F having a high transfer data rate and versatility is required. As a response to such a demand, there is a data communication bus (hereinafter referred to as “1394 serial bus”) compliant with the IEEE 1394 standard.

The outline of the 1394 serial bus will be described below.
With the advent of home digital VTRs and DVDs, real-time data such as video data and audio data is required, and data with a large amount of information is transferred in real time and taken into a PC or transferred to other digital devices. To do this, a digital I / F capable of high-speed data transfer is required. One of the digital I / F standards developed from such a viewpoint is the IEEE 1394-1995 standard (High Performance Serial Bus).

  The connection method between the devices in the 1394 serial bus is such that the daisy chain method and the node branching method can be mixed, and each device can be connected with a high degree of freedom. Each device has a unique node ID and recognizes each other, thereby forming one network in a range connected via the 1394 serial bus. By simply connecting each device sequentially with a single 1394 serial bus cable, each device plays a role of relay and constitutes a single network as a whole.

  In addition, the so-called hot-swap function that allows the cable to be plugged and unplugged while the device is turned on, or the so-called plug-and-plug function that automatically recognizes the device and connection status when the 1394 serial bus cable is connected to the device Has a play function.

  The 1394 serial bus has a layer structure as a whole. In the 1394 serial bus, the most hardware-like is a 1394 serial bus cable, and there is a connector port to which the connector of the cable is connected. In the upper layer, there are a physical layer and a link layer as hardware. Furthermore, there are a transaction layer and an application layer, usually configured as software.

  The connection cable of the 1394 serial bus is provided with a power supply line in addition to two pairs of twisted pair signal lines. As a result, it is possible to supply power to a device that does not have a power supply or a device whose power supply voltage has dropped due to a failure or the like. The voltage of the power supply flowing in the power supply line is specified as 8 to 40 V, and the current is specified as the maximum current DC1.5A.

  The hardware part in the 1394 serial bus is a substantial interface chip (IC or the like) part, the physical layer of the hardware part performs encoding, connector-related control, etc., and the link layer is a packet transfer or cycle. Control time etc. Further, the transaction layer of the firmware unit manages data to be transferred (transaction), and issues instructions such as read and write. The serial bus management is a part that manages the connection status and node ID of each connected device, and manages node control and network configuration.

  Further, the data transfer rate is defined as 100/200/400 Mbps, and when the data transfer rate is different between devices, the device having the higher transfer rate supports the lower transfer rate and is compatible. The data transfer mode includes an asynchronous transfer mode for transferring asynchronous data such as control signals (control data), and an isochronous transfer mode for transferring isochronous data such as real-time video data and audio data. Asynchronous data and isochronous data are mixed in each cycle with priority given to isochronous data transfer following transfer of a cycle start packet (CSP) indicating the start of each cycle (usually 125 μs for one cycle). It can be transferred.

  As described above, in the 1394 serial bus, each connected device (node) is given a node ID and recognized as a network configuration. Here, for example, it is assumed that the network configuration has changed due to increase / decrease of the number of nodes due to the insertion / extraction of a cable, the power ON / OFF operation, etc., and the network configuration needs to be newly recognized. At this time, the node detecting the change transmits a bus reset signal on the 1394 serial bus and enters an operation mode for recognizing a new network configuration. The method for detecting a change in the network configuration is performed by detecting a change in the bias voltage on the 1394 port board.

  The physical layer of each node receives the bus reset signal transmitted from one node via the 1394 serial bus, and simultaneously transmits the generation of the bus reset to the link layer and transmits the bus reset signal to the other nodes. Eventually, after all nodes detect the bus reset signal, the bus reset is activated.

The bus reset is activated not only by the above-described hardware detection such as cable insertion / extraction or communication abnormality but also by directly issuing a command to the physical layer by host control from the protocol. When the bus reset is activated, the data transfer via the 1394 serial bus is suspended and the data transfer during the bus reset is awaited. Then, after the bus reset is completed, data transfer is resumed under a new network configuration. The above is the bus reset sequence.
IEEE Std 1394-1995, IEEE Standard for a High Performance Serial Bus, Institute of Electrical and Electronics Engineers, Inc.

  Here, in the above-described conventional example, a recorded or stored file and attribute data of the file can be transferred at high speed using isochronous data. However, in the case of this isochronous transfer, the reliability of data transfer is not guaranteed. In addition, asynchronous transfer using asynchronous data that guarantees the reliability of data transfer has a problem that a mechanism for transferring recorded or stored files and attribute data of files is not defined. It was.

  The present applicant has proposed a method for solving the above-described problems. In the above method, the connection procedure between a plurality of functional blocks inside the device and the input / output port of the device, and between the devices are proposed. It was necessary to provide a separate connection procedure, and the connection procedure was complicated. In the above method, exclusive control is not possible with respect to the connection between a plurality of functional blocks inside the device and the input / output port of the device and the connection between the devices.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a communication system capable of high-speed data transfer and guaranteeing the reliability of data transfer with a simple connection procedure. . It is another object of the present invention to allow exclusive control by connection between a plurality of functional blocks inside a device and an input / output port of the device, and connection between devices.

  The communication system of the present invention is a communication system in which a transmission node that transmits data and a reception node that receives data transmitted from the transmission node are connected via a serial bus capable of transmitting and receiving serial data. A control means for outputting arbitrary control data, and the transmission node has a transmission means for transmitting data via the serial bus, and an output means capable of outputting data to the transmission means. A functional operation unit having a predetermined function that can be controlled by control data from the control unit, and a communication path control unit that controls a connection state between the transmission unit and the output unit. Control data for controlling a connection state between the transmission unit and the output unit that can be transmitted using a control command is included.

  Another feature of the communication system according to the present invention is that a transmission node that transmits data and a reception node that receives data transmitted from the transmission node are connected via a serial bus capable of transmitting and receiving serial data. The communication system includes control means for outputting arbitrary control data, and the receiving node receives the data received by the receiving means and receiving means for receiving the data via the serial bus. A function operating means having a predetermined function that can be controlled by control data from the control means, and a communication path control means for controlling a connection state between the receiving means and the input means. The control data is control data for controlling the connection state between the receiving means and the input means that can be transmitted using a single control command. And wherein the Mukoto.

  Another aspect of the communication system of the present invention is that a control node that transmits arbitrary control data, and a transmission node that receives the control data and a reception node via a serial bus for transmitting and receiving serial data. In the connected communication system, the transmission node can be controlled by a part of the control data, and has n functions (n is a natural number) each having a predetermined function including output means for outputting data. ) And a transmission means for transmitting data by asynchronous transfer via the serial bus, and the receiving node receives the data by asynchronous transfer via the serial bus. Comprising a receiving means, wherein the control node performs a single data transmission between the output means and the sending means. It said control data including data to ensure the data transmission path and transmits to the transmission node.

  Another aspect of the communication system of the present invention is that a control node that transmits arbitrary control data, and a transmission node that receives the control data and a reception node via a serial bus for transmitting and receiving serial data. In the connected communication system, the transmission node includes transmission means for transmitting data by asynchronous transfer via the serial bus, and the reception node can be controlled by a part of the control data. In addition, m function operation means (m is a natural number) each having a predetermined function each having an input means for inputting data, and reception for receiving the data by asynchronous transfer via the serial bus Means for controlling the input means and the receiving means by a single data transmission. It said control data including data to ensure the data reception path and transmits to the receiving node.

  Another aspect of the communication system of the present invention is that a control node that transmits arbitrary control data, and a transmission node that receives the control data and a reception node via a serial bus for transmitting and receiving serial data. A connected communication system, wherein the transmission node includes recording means for recording data, and transmission means for transmitting data recorded in the recording means by asynchronous transfer via the serial bus. The receiving node includes receiving means for receiving data transmitted from the transmitting node, and the control data is logically transmitted between the recording means and the transmitting means by a single data transmission. Including control data for making a simple connection.

  Another aspect of the communication system of the present invention is that a control node that transmits arbitrary control data, and a transmission node that receives the control data and a reception node via a serial bus for transmitting and receiving serial data. The transmission node includes a file system and provides the file system to the reception node by asynchronous transfer via the serial bus. The control data is a single data It includes control data for performing a logical connection with the file system by transmission.

  A terminal device of the present invention is a terminal device connected to a receiving node that receives data via a serial bus capable of transmitting and receiving serial data, and a transmission means for transmitting data via the serial bus The transmission means has an output means capable of outputting data, and a function operation means having a predetermined function that can be controlled based on control data, and a connection state between the transmission means and the output means is a single And a communication path control means that can be controlled based on the control data transmitted using the control command.

  Another feature of the terminal device according to the present invention is a terminal device connected to a transmission node for transmitting data via a serial bus capable of transmitting and receiving serial data, wherein the data is transmitted via the serial bus. Receiving means for receiving; input means capable of inputting data received by the receiving means; functional operation means having a predetermined function that can be controlled based on control data; and the receiving means and the input means And a communication path control means capable of controlling the connection state based on control data transmitted using a single control command.

  The communication system control method of the present invention is a communication system in which a transmission node that transmits data and a reception node that receives data transmitted from the transmission node are connected via a serial bus capable of transmitting and receiving serial data. And a transmission means for outputting data from a functional operation means having a predetermined function provided in the transmission node, and a transmission means for transmitting data to the outside via the serial bus. The connection state is controlled based on control data transmitted using a single control command.

  Another aspect of the control method of the communication system of the present invention is that a transmission node that transmits data and a reception node that receives data transmitted from the transmission node via a serial bus capable of transmitting and receiving serial data. And a communication system connected to the receiving node, wherein the receiving node has an input means for inputting data to a functional operation means having a predetermined function, and receives data from the outside via the serial bus. The connection state with the receiving means for performing the control is controlled based on the control data transmitted using a single control command.

  The program of the present invention includes an output means for outputting data from a functional operation means having a predetermined function, which is provided in a transmission node connected to a reception node that receives data via a serial bus capable of transmitting and receiving serial data. , Causing a computer to execute control of a connection state with a transmission means for transmitting data to the outside via the serial bus based on control data transmitted using a single control command .

  Another feature of the program of the present invention is that data is transmitted to a functional operation means having a predetermined function provided in a receiving node connected to a transmitting node that transmits data via a serial bus capable of transmitting and receiving serial data. Control of the connection state between the input means for inputting and the receiving means for receiving data from the outside via the serial bus is performed on the computer based on the control data transmitted using a single control command. It is made to perform.

  The computer-readable recording medium of the present invention outputs data from a functional operation unit having a predetermined function provided in a transmission node connected to a reception node that receives data via a serial bus capable of transmitting and receiving serial data. Control of the connection state between the output means for transmitting and the transmitting means for transmitting data to the outside via the serial bus based on the control data transmitted using a single control command The program for recording is recorded.

  Another feature of the computer-readable recording medium of the present invention is that the reception node connected to the transmission node that transmits data via a serial bus capable of transmitting and receiving serial data has a predetermined function. Control data transmitted using a single control command to control the connection state between the input means for inputting data to the operating means and the receiving means for receiving data from the outside via the serial bus. Based on the above, a program for causing a computer to execute is recorded.

  According to the present invention, since the control data including the control data for controlling the connection inside the node is transmitted by a single data transmission, the connection between devices and the connection within the device can be performed by a single data transmission. It is possible to realize a communication system that can be controlled at the same time and can perform high-speed data transfer with a simple connection procedure and can guarantee the certainty of data transfer.

  In addition, since the control data for performing exclusive control regarding the connection between devices and the connection within the device is transmitted by a single data transmission, both the connection between the devices and the control within the device are controlled. Therefore, exclusive control can be performed efficiently.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration example of a communication system according to an embodiment of the present invention, and also shows an electrical connection configuration of each functional block. In FIG. 1, reference numeral 100 denotes a printer, and reference numeral 200 denotes an electronic still camera, which are connected so as to be communicable via an IEEE 1394 serial bus cable (hereinafter also referred to as “1394 cable”) 10.

  The configuration of each device will be described. The printer 100 includes a communication unit 101, a communication auxiliary unit 102, an image processing unit 103, a removable recording unit 104, a display unit 105, a control unit 106, an operation unit 107, a memory 108, and a print output unit 109. A control bus 110 for performing control and a data bus 111 for transmitting data are connected.

  The communication unit 101 is for communicating with an external device (for example, the electronic still camera 200) or the like via the 1394 cable 10 by a communication method compliant with the IEEE 1394 standard. The communication auxiliary unit 102 is for converting information in the printer 100 into a communication method compliant with the IEEE 1394 standard.

  The image processing unit 103 performs image processing on the data so that the data sent to the printer 100 via the 1394 cable 10 and the data recorded in the removable recording unit 104 can be printed out. The detachable recording unit 104 is not limited to the printer 100 and can be connected to another device to record and read data. The display unit 105 is operated when the user operates the printer 100. Present information to assist.

  The control unit 106 controls the entire printer 100. The operation unit 107 is for the user to actually operate the printer 100, and the memory 108 temporarily records the data subjected to image processing for print output by the image processing unit 103, and prints the data. The output unit 109 prints out the data subjected to image processing.

  The electronic still camera 200 includes a communication unit 201, a communication auxiliary unit 202, an image processing unit 203, a removable recording unit 204, a display unit 205, a control unit 206, an operation unit 207, a memory 208, and an imaging unit 209. Are connected by a control bus 210 for performing control and a data bus 211 for transmitting data.

  The communication unit 201 is for communicating with an external device (for example, the printer 100) or the like via the 1394 cable 10 by a communication method compliant with the IEEE 1394 standard. The communication auxiliary unit 202 is for converting information inside the electronic still camera 200 into a communication method compliant with the IEEE 1394 standard.

  The image processing unit 203 performs image processing on the data obtained by the imaging unit 209 so that the data can be recognized as an image. The detachable recording unit 204 is not limited to the electronic still camera 200, and can be connected to another device to record and read data. The display unit 205 is operated by the user to operate the electronic still camera 200. Information to assist the operation when presenting.

  The control unit 206 controls the entire electronic still camera 200. The operation unit 207 is for a user to actually operate the electronic still camera 200, and the memory 208 is for temporarily recording data subjected to image processing. The imaging unit 209 is for capturing a subject image and obtaining it as an electrical signal.

  Next, the operation of each device when image data is transferred from the electronic still camera 200 to the printer 100 via the 1394 serial bus and printed out by the printer 100 will be described.

  When the user performs an operation for prompting shooting with the operation unit 207 while confirming the subject image on the display unit 205 with the electronic still camera 200, the control unit 206 controls the imaging unit 209 to capture the subject image. Image data obtained by the imaging unit 209 is temporarily recorded in the memory 208 via the data bus 211. Further, the image data recorded in the memory 208 is subjected to image processing in the image processing unit 203 and then recorded as a file in the removable recording unit 204 via the data bus 211.

  The image related to the image data recorded in the detachable recording unit 204 can be displayed on the display unit 205 when the user performs a reproduction operation with the operation unit 207, or the detachable recording unit from the electronic still camera 200 can be displayed. It is also possible to reproduce (display) by disconnecting 204 and connecting it to a PC or the like.

  The image data recorded in the detachable recording unit 204 can be transmitted to the printer 100 via the 1394 serial bus via the communication unit 201 and printed out. In this case, the electronic still camera 200 must perform communication using a communication method compliant with the IEEE 1394 standard in order to guarantee data transmission. In this embodiment, data transfer is performed using the AV / C Compatible Asynchronous Serial Bus Connections standard (1394 Trade Association) and the AV / C Commands for Management of Asynchronous Serial Bus Connections standard (1394 Trade Association). Hereinafter, the above two transfer methods (standards) are collectively referred to as “Asynchronous Connection”. The communication unit 201 has means for performing the asynchronous connection, and data transfer is thereby guaranteed.

  Image data of an image to be transferred to the printer 100 and printed is selected from the image data recorded in the removable recording unit 204 displayed on the display unit 205 of the electronic still camera 200 using the operation unit 207. The selected image data is transmitted to the printer 100 via the 1394 serial bus, but before transmitting the image data, a command for controlling the printer 100 is transmitted from the electronic still camera 200 to the printer 100.

  The transmitted command is transferred to the control unit 106 via the communication unit 101 of the printer 100, and the control unit 106 controls the printer 100 to wait for data reception. Thereafter, the selected image data is transmitted to the printer 100 by the asynchronous connection via the communication unit 201 of the electronic still camera 200. When the printer 100 waiting for data reception receives the image data transmitted from the electronic still camera 200, it temporarily records it in the memory 108 via the data bus 111. The image data recorded in the memory 108 is subjected to image processing for print output by the image processing unit 103 and output by the print output unit 109.

The above description is a push model in which image data is transmitted from the electronic still camera 200 to the printer 100 for printing.
Hereinafter, an operation when the printer 100 selects an image recorded in the electronic still camera 200 and acquires and prints the image via the 1394 serial bus will be described.

  The communication auxiliary unit 202 of the electronic still camera 200 reads file information related to image data recorded as a file in the removable recording unit 204 and performs mapping to a predetermined file system. The file system expressed by the communication auxiliary unit 202 can be referred to from an external device via the 1394 serial bus. That is, each device connected via the 1394 serial bus has the same communication on the 1394 serial bus even if the recording method of the recording medium in each device is different by mounting the communication auxiliary unit 202 in each device. Can be handled as a file system.

  FIG. 2 is a diagram showing a configuration example of the file system in the present embodiment. In FIG. 2, blocks having the same functions as those shown in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  An image photographed by the electronic still camera 200 is recorded in the recording format A2-1 in the detachable recording unit 204 shown in FIG. The communication auxiliary unit 202 converts the file information recorded in the recording format A2-1 into an information form (file format) in a predetermined format as shown in FIG. 2, and file information obtained by the conversion 2-5 is temporarily recorded in the internal memory 2-6.

  Then, a predetermined operation is performed on the operation unit 107 of the printer 100, and a command for acquiring file information included in the electronic still camera 200 is transmitted from the printer 100 to the electronic still camera 200. Thereby, the printer 100 can acquire the file information 2-5 held in the internal memory 2-6 of the communication auxiliary unit 202 via the 1394 serial bus. Even if the file information is recorded in the removable recording unit 204 of the electronic still camera 200 in the recording format B2-2, the recording format C2-3, or the recording format D2-4 different from the recording format A2-1. The printer 100 can recognize the file information 2-5 having the same file format.

  The file information acquired as described above is displayed on the display unit 105 of the printer 100, and the user selects an image to be printed using the operation unit 107. In response to the selection, the printer 100 transmits a command for acquiring image data of the selected image to the electronic still camera 200. At the same time, the printer 100 enters a data reception waiting state in order to receive and print image data via the 1394 serial bus.

  When the electronic still camera 200 receives a command requesting acquisition of the image data, the electronic still camera 200 transmits the image data to the printer 100 through an asynchronous connection. When the printer 100 receives image data from the electronic still camera 200, the printer 100 temporarily records the image data in the memory 108, performs image processing for print output by the image processing unit 103, and then prints the print output unit 109. To output.

  Next, means for accessing a file recorded on a recording device (recording medium) such as the removable recording units 104 and 204 shown in FIG. 1 will be described.

<Data structure of file system>
The recording device according to the present embodiment uses a file path (file_path) when accessing a specified file. The file path is variable length data, for example, a full path name from the root directory. In the above file path, for example, the character “/” (“5C ₁₆ ”) (subscript “16” indicates a hexadecimal notation as a directory delimiter. The same applies to the following. ) And a NULL (“00 ₁₆ ”) character as a terminator.

The data length of the file path is indicated by a file path length (file_path_length), and the file path length does not include the length of the last NULL character.
The file path data and the file path length data are used in a file access command set described later.

  A device (hereinafter referred to as “controller”) that acquires file information from a recording device in the present embodiment requests a file list from the recording device in order to acquire file information. The file list is transferred from the recording device to the controller as a response to a command requesting the file list. Here, the file list includes a plurality of directory entries and information on files or directories held by the directory entries. Further, the directory entry of the file list is, for example, 20 bytes in size and has a data structure as shown in FIG.

  FIG. 3 is a diagram showing an example of the data structure of the directory entry in the present embodiment. Each field of the directory entry shown in FIG. 3 has a data structure similar to, for example, a data structure known as a DOS (disk operating system) -FAT (file allocation table) system. However, the directory entry shown in FIG. 3 does not hold the current directory and parent directory information as in the DOS-FAT system.

In FIG. 3, the first 11 bytes (address offset values “00 ₁₆ ” to “0A ₁₆ ”) are a name field 301 and an extension field 302, which indicate the name of the file. The two fields 301 and 302 can form, for example, a file name of 8 characters and an extension of 3 characters in the DOS-FAT system described above. When the name or extension of the file held in the recording device is smaller than the two field lengths, for example, padding bytes are padded. The value of the padding byte is “20 ₁₆ ”, for example.

The next 1-byte field (address offset value “0B ₁₆ ”) is an attribute (attribute_byte) field 303, which indicates file attribute information. The attribute field 303 includes a bit field as shown in FIG.

  FIG. 4 is a diagram showing a configuration of the attribute field 303, and a directory bit 401 indicates whether or not the directory entry is a subdirectory. For example, when the directory bit 401 is set to “1”, the directory entry is a subdirectory. A read-only (read_only) bit 402 indicates whether or not only a file in the directory entry can be read and cannot be written / erased. For example, when the read-only bit 402 is set to “1”, the file is read-only. In FIG. 4, a plurality of ignored bits are ignored by the controller regardless of the value written by the recording device.

Returning to FIG. 3, the update time (modification_time) field 304 (address offset value “0C ₁₆ ”, “0D ₁₆ ”) and the update date (modification_date) field 305 (address offset value “0E ₁₆ ”, “0F ₁₆ ”) Indicates the latest update date and time of the file. A file size (file_size) field 306 (address offset values “10 ₁₆ ” to “13 ₁₆ ”) indicates a file length (in bytes).

  In the present embodiment, it is possible to handle a plurality of recording media and so-called partitions that are divided into a plurality of portions on the recording media. The recording medium is referred to as “physical volume”, for example, and the partition is referred to as “logical volume”, for example.

  In the present embodiment, the physical volume is designated by physical volume number (physical_volume_number) data, and the logical volume is designated by logical volume number (logical_volume_number) data. The controller can designate a specific area on the recording device by the physical volume number and the logical volume number. The physical volume number and the logical volume number are used in a file access command set described later.

The physical volume number data takes a value from “00 ₁₆ ” to “FE ₁₆ ”, for example, and the first physical volume number takes a value “00 ₁₆ ”. The value “FF ₁₆ ” is special, for example, and the physical volume number value has a different meaning depending on the file access command set described later.

The logical volume number data takes a value of “00 ₁₆ ” to “FE ₁₆ ”, for example, and the first logical volume number takes a value of “00 ₁₆ ”. The value “FF ₁₆ ” is special, for example, and the logical volume number value has a different meaning depending on a file access command set described later.

In the present embodiment, the case where the values of the physical volume number and the logical volume number are “FF ₁₆ ” is an exception, but it may be configured to take a value from “00 ₁₆ ” to “FF ₁₆ ”. .

  In the recording device of the present embodiment, the media count (media_generation_count) is used to notify the exchange of the recording medium, and when the recording medium is inserted into the recording device, the value of the media count is increased by “1”. . When the recording device supports a plurality of physical volumes, each recording volume has a unique media count.

  When the recording device is initialized by turning on the power or the like, the media count is initialized. Note that the initial value of the media count is a value unique to the recording device, and may be, for example, zero or a random number. Also, if the recording device can store the media count value in flash memory or other non-volatile memory when the power is turned off, etc., the media / memory stored as the initial value at the next initialization A count value may be used. In the present embodiment, the media count is 1-byte data, and the media count value is held when a bus reset occurs.

  When the controller detects that the recording medium is inserted into the recording device and the value of the media count is increased, the controller reacquires the file list described above. In the recording device according to the present embodiment, since the media count value does not increase when the recording medium is removed, it is not necessary to acquire a new file list by removing the recording medium, and an unnecessary transaction is generated. There is no.

<File access command set>
Next, commands related to the file system of this embodiment will be described. In the present embodiment, various commands relating to files such as file attribute acquisition and file transfer can be performed by using commands.
The command relating to the file system of the present embodiment uses, for example, FCP (Function Control Protocol) defined in the IEEE 1394 standard.

Hereinafter, FCP will be described with reference to FIG.
FIG. 5 is a conceptual diagram for explaining FCP. FCP is designed based on the IEEE 1394 standard to control devices connected via a 1394 serial bus, and various command sets and command transactions are available on the FCP. In FCP, when transmitting a command and a response, an IEEE1394 standard asynchronous packet is used.

  In FCP, a node that controls other node (s) is called a “controller”, and a controlled node is called a “target”. In FIG. 5, 500 operates as a controller and 510 operates as a target.

  In FCP, an FCP frame sent from the controller to the target is called a “command frame”, and an FCP frame sent from the target to the controller is called a “response frame”. A register prepared to receive the command frame is referred to as a “command register”, and a register prepared to receive the response frame is referred to as a “response register”. In FIG. 5, 501 and 502 are command registers and response registers on the controller 500, and 511 and 512 are command registers and response registers on the target 510.

FIG. 6 shows the data structure of an asynchronous packet transmitted using an FCP frame.
In FIG. 6, 601 is a destination ID field, 602 is a transaction label (tl) field, 603 is a retry code (rt) field, 604 is a transaction code (tcode) field, 605 is a priority (pri) field, and 606 is Source ID field, 607 is a destination offset field, 608 is a data length field, 609 is an extended transaction code field, 610 is a header CRC (header_CRC) field, 611 is a data field (FCP frame), and 612 is a data CRC (data_CRC) It is a field. The asynchronous packet is, for example, a data packet in units of 4 bytes (32 bits, hereinafter referred to as “quad red”).

  In the asynchronous packet shown in FIG. 6, the first 16-bit field is a destination ID field 601 indicating the node ID of the receiving side (transmission destination). The next 6-bit field is a transaction label field 602, which is a tag unique to each transaction. The next 2-bit field is a retry code field 603, which specifies whether or not the packet tries to retry.

The next 4-bit field is the transaction code field 604, which specifies the format of the packet and the type of transaction that must be performed. In the present embodiment, for example, the value of this field is “0001 ₂ ” (the subscript “2” indicates binary notation, and the same applies to the following). Use request transaction.

The next 4-bit field is a priority field 605, which specifies the priority order. Since an asynchronous packet is used in this embodiment, the value of this field is “0000 ₂ ”, for example.

  The next 16-bit field is a source ID field 606, which indicates the node ID of the transmission side (transmission source). The next 48-bit field is the destination offset field 607, and the lower 48 bits of the receiving node address of the packet are specified by this field.

The next 16-bit field is a data length field 608, which indicates the length of a data field 611 described later in bytes. The next 16-bit field is an extended transaction code field 609. In the data block write request transaction used in this embodiment, this value is, for example, “0000 ₁₆ ”.

  The next 32-bit field is a header CRC field 610, which is used to detect an error in the packet header (from the above-described destination ID field 601 to extended transaction code field 609).

The next variable length field is a data field 611, which is filled with a command frame and a response frame used in CTS (Command / Transaction Set) described later. The data field 611 is referred to as “payload”. In the present embodiment, a value of “0” is filled in bits that are less than a multiple of a quadlet in the data field 611. That is, when the data length stored in the data length field 608 is indicated in units of bytes (8 bits), if the value of the data length field 608 is not a multiple of “4”, the data field is a quadlet. It is filled with data of “00 ₁₆ ” until it satisfies

  The last 32-bit field is a data CRC field 612, which is used for error detection of the data field 611 in the same manner as the header CRC field 610 described above.

  In FCP, a data field 611 that is a payload of a data block write request (“Write request for data block packet”) is called an “FCP frame”, and a command frame is written to a command register on the target and a response is made. The frame is written into a response register on the controller. Here, the command register and the response register are separated from each other, and the destination offset address of these registers is defined by the FCP as shown in FIG.

In this embodiment, as the destination offset address, "FFFF F000 0B00 _16", and "FFFF F000 0D00 _16" only write transactions containing (Write transaction) is allowed.

  CTS is one component of an FCP frame that specifies a command set, a structure of a command field and a response field, and a transaction rule used when sending a command and a response.

FIG. 8 shows the data structure of an FCP frame used in CTS.
In FIG. 8, reference numeral 801 denotes a CTS field. The CTS field 801 is a 4-bit field, and an example of encoding of the CTS field 801 is shown in FIG. In this embodiment, for example, “0000 ₂ ” is used as the value of the CTS field 801.

FIG. 10 is a diagram illustrating a data structure of the command frame and the response frame in the present embodiment.
10A shows the data structure of the command frame. In FIG. 10A, 1001 is a command type (ctype) field, 1002 is a subunit type (subunit_type) field, and 1003 is a subunit ID (subunit_ID). A field 1004 is an opcode. In FIG. 10A, (n + 1) (n is an integer) operands (operand [0], operand [1],..., Operand [n]) follow each byte after the operation code 1004.

A command type field 1001 consisting of 4 bits indicates a command type.
FIG. 11 is a diagram illustrating an example of the relationship between the value of the command type field 1001 and the command type.

As shown in FIG. 11, the command frame whose value in the command type field 1001 is “0000 ₂ ” (command type is “CONTROL”) is used by the controller to control the target. The control content is specified by an operation code and an operand described later. A command frame whose value in the command type field 1001 is “0001 ₂ ” (command type is “STATUS”) is used by the controller to inquire about the current state of the target. The state is specified by an opcode or operand described later.

Further, the command frame whose value in the command type field 1001 is “0011 ₂ ” (command type is “NOTIFY”) is used by the controller to notify the target that the state of the target has changed. Specifying a state by an opcode or operand described later is the same as the “STATUS” command described above.

Furthermore, a command frame with the same opcode is mounted on the target in the command frame with the command type field 1001 value of “0010 ₂ ” or “0100 ₂ ” (command type is “SPECIFIC INQUIRY” or “GENERAL INQUIRY”). It is used to check whether or not Here, in the case of the “SPECIFIC INQUIRY” command, the operation code and all the operands must be specified. In the case of the “GENERAL INQUIRY” command, only the operation code is specified. This is the difference between the “SPECIFIC INQUIRY” command and the “GENERAL INQUIRY” command.

  A 5-bit subunit type field 1002 and a 3-bit subunit ID field 1003 identify a subunit to which a command frame is sent. Subunits are defined in the AV / C Digital Interface Command Set General Specification (March 1998, 1394 Trade Association) standard (hereinafter referred to as “AV / C command set standard”), etc., and the AV unit (hereinafter simply referred to as “AV / C command set standard”). It is also a virtual entry that is uniquely identified among the "units" and provides a consistent set of functions. The above units are similarly defined in the AV / C command set standard. The AV unit indicates an electronic device having a node connected to the 1394 serial bus.

  According to the AV / C command set standard, a unit can have a plurality of subunits. Therefore, the subunit type field 1002 and the subunit ID field 1003 indicate addresses for identifying subunits in units connected to the 1394 interface. An example of the relationship between the value of the subunit type field 1002 and the subunit type is shown in FIG.

The subunit type field 1002 and the subunit ID field 1003 are collectively referred to as “subunit address” or “AV / C address”. If the value of the subunit type field 1002 is “11111 ₂ ” and the value of the subunit ID field 1003 is “0112”, the subunit address indicates the unit.

In this embodiment, when a command frame is transmitted to the printer 100, for example, a value “00010 ₂ ” is specified in the subunit type field 1002 and a value “000 ₂ ” is specified in the subunit ID field 1003. In this embodiment, when a command frame is transmitted to the camera subunit of the electronic still camera 200, for example, a value of “00111 ₂ ” is stored in the subunit type field 1002 and “000 ₂ ” is stored in the subunit ID field 1003. Specify the value of.

Furthermore, in the present embodiment, the communication auxiliary unit 202 that forms the file system of the electronic still camera 200 operates as a camera storage subunit in FIG. Therefore, when a command frame is transmitted to the subunit, for example, a value of “01011 ₂ ” is designated in the subunit type field 1002 and a value of “000 ₂ ” is designated in the subunit ID field 1003.

  The operation code 1004 defines a control content and a state returned by a response frame described later. The number and meaning of operands following the opcode 1004 differ depending on the command type, subunit type, or opcode described above.

FIG. 10B shows the data structure of the response frame. In FIG. 10B, fields having the same functions as those shown in FIG. 10A are denoted by the same reference numerals, and redundant description is omitted. In FIG. 10B, reference numeral 1005 denotes a response field indicating the response type.
FIG. 13 is a diagram illustrating an example of the relationship between the value of the response field 1005 and the response type.

  In this embodiment, the target subunit generates an appropriate response frame and returns it to the controller for the command frame sent from the controller configured by the command type, subunit address, opcode, and operand. It has become. The response frame includes a response type, a subunit address, an operation code, and an operand corresponding to the received command frame.

  Next, commands of the camera / storage / subunit in this embodiment will be described. FIG. 14 is a diagram illustrating an example of a relationship between a command of the camera / storage subunit and an operation code value of the camera / storage subunit.

  When the command of the camera / storage / subunit is issued as a command frame from the controller and returned to the controller as a response frame, a common header area (hereinafter referred to as “common frame header”). .) FIG. 15 shows a format of a common frame header in a control command (hereinafter also simply referred to as “command”). In FIG. 15, the format of the common frame header in the command frame is shown as an example.

  In FIG. 15, the opcode value shown in FIG. 14 is input to the opcode. In addition, the same value as the value of the operation code of the command frame is input to the operation code in the response frame.

The 0th operand (operand [0]) is a 1-byte subfunction field, and specifies the operation mode of the control command. FIG. 16 shows the relationship between the operation mode of the control command and the subfunction field value. If the camera storage sub-unit receives a command frame with an invalid subfunction field value, it returns a response frame with a response value of “NOT IMPLEMENTED” (response field value is “1000 ₂ ”) . Also, the same value as the value of the 0th operand of the command frame is input to the 0th operand of the response frame.

The first operand (operand [1]) is a 1-byte field, and a fixed value “FF ₁₆ ” is input. A result code is input to the first operand in the response frame and returned. An example of the encoding of the result code is shown in FIG. Here, when the camera storage subunit returns a “REJECTED” response frame (response field value is “1010 ₂ ”) for a plurality of reasons, the data with the smallest value shown in FIG. As the first operand. Also, when the camera / storage subunit returns an “INTERIM” response frame (response field value is “1111 ₂ ”), “FF ₁₆ ” that is the same as the fixed value issued by the controller is input as the result code. .

The second operand (operand [2]) is a physical volume number field that specifies a physical volume. The third operand (operand [3]) is a logical volume number field that specifies a logical volume. Further, as described above, when the controller indicates that these fields are not used, the value “FF ₁₆ ” is input.

  Here, when the value of the physical volume number field or the logical volume number field in the command frame is invalid, the camera storage subunit returns a “REJECTED” response frame or a “NOT IMPLEMENTED” response frame. At this time, in the present embodiment, for example, the following operation is performed.

• If there is no recording medium with the physical volume number (physical volume number field value) specified in the command frame, the camera storage subunit will have the value “no media” (A0 ₁₆ ) as the result code. Returns the “REJECTED” response frame input in the 1 operand.

• If the logical volume number (logical volume number field value) specified in the command frame does not exist in the physical volume, the camera storage subunit will return the value of “invalid volume number” (91 ₁₆ ) as the result code. Returns a “REJECTED” response frame with the first operand input.

• If a physical volume number that does not exist in the camera / storage / subunit is specified in the command frame, the camera / storage / subunit returns a “NOT IMPLEMENTED” response frame.

The fourth operand (operand [4]) is a media count field, which is used to notify the exchange of the recording media. When the controller issues a command frame other than the media information (“MEDIA INFO”) command frame and the volume information (“VOLUME INFO”) command frame shown in FIG. 14, the media count held by the controller is displayed. A value is set in the media count field. When the controller issues a media information command frame or a volume information command frame, a value “FF ₁₆ ” is set in the media count field.

In response to a command frame other than the media information command frame, the camera storage subunit returns a response frame in which the media count value held by itself is set as the fourth operand. At this time, if the received command frame is a command frame other than the media information command frame and the volume information command frame, the camera / storage sub-unit stores the media count value held by itself and the command frame. Compare with the media count value. As a result, if the media count value is different, the camera storage sub-unit will send a “REJECTED” response frame with the result code “invalid generation count” (90 ₁₆ ) entered in the first operand. return.

  Also, typically, before the controller first sends any control command frame to the camera storage subunit, the controller issues a volume information command frame to obtain the current media count value.

FIG. 18 is a diagram showing the format of a file list command (FILE LIST control command) frame.
In the file list command frame, the first 6-byte field is the common frame header described above.

The fifth operand (operand [5]) is a file type (file_type) field, and specifies the file type of the directory entry to be acquired. The definition of the file type field value is shown in FIG. When the file type field value is “00 ₁₆ ” (file type “any”), the returned directory entry includes an arbitrary file or directory. When the file type field value is “01 ₁₆ ” (file type “still image”), the returned directory entry includes only still image files.

The lower 2 bits of the sixth operand (operand [6]) are an attribute field that specifies the type of directory entry to be acquired. The definition of the attribute field is shown in FIG.
When the lower bit (“bit0”) of the attribute field is set to “1”, the camera storage subunit returns a directory entry including the subdirectory. On the other hand, when the lower bit of the attribute field is cleared to “0”, the camera storage subunit does not return the directory entry including the subdirectory.

When the upper bit (“bit1”) of the attribute field is set to “1”, the camera storage subunit returns a directory entry including a file. On the other hand, when the upper bit of the attribute field is cleared to “0”, the camera storage subunit does not return the directory entry including the file.
Further, when both bits of the attribute field are set to “1”, the camera storage subunit returns a directory entry including a file and a subdirectory.

  The seventh and eighth operands (operand [7] and operand [8]) constitute a start number (start_number) field, and the start number field specifies the start position of the directory entry to be acquired. The start number field value starts from “0”, and a paging parameter to be described later is designated by the start number field value.

  The most significant bit (MSB) of the ninth operand (operand [9]) is an end of list (“eol”) bit. The end of list bit in the response frame indicates whether or not the last directory entry in the response frame is the last directory entry in the directory specified in the command frame.

  Specifically, when the end of list bit value of the response frame is cleared to “0”, the last directory entry in the response frame is the last directory of the directory specified in the command frame. Indicates that it is not an entry. On the other hand, when the value of the end of list bit of the response frame is set to “1”, the last directory entry in the response frame is the last directory entry of the directory specified in the command frame. Indicates.

  The controller clears the end-of-list bit to “0” and issues a command frame.

  The lower 5 bits of the ninth operand are the number of entries (number_of_entries) field. The command frame specifies the number of directory entries to be acquired, and the response frame indicates the number of directory entries actually included in the response frame. The entry number field value in the command frame may not match the entry number field value in the response frame as a response, but the entry number field value in the response frame corresponds to the entry in the command frame. Guaranteed to be less than a few field values.

  A paging mechanism is provided based on the values of the start number field, end of list bit, and number of entries field. Here, paging is a mechanism in which data is exchanged by a plurality of commands and response transactions because there is a limit to the data length that can be returned at once by the response frame from the camera / storage subunit.

FIG. 21 is a flowchart showing the paging operation. FIG. 21 shows an example of a paging operation at the time of file list acquisition in the controller.
In FIG. 21, when the paging operation in the present embodiment is started in step step 1, the controller initializes the value of the start number in step step 2 (for example, “0” is set to the value of the start number). input).

  In the next step step 3, the controller initializes the value of the number of entries. Here, as the initial value of the number of entries, a sufficiently large value is input according to the maximum number of bytes of the command frame and the response frame. For example, when the maximum number of bytes of the command frame and the response frame is 256 bytes, “128” or the like is input as the initial value of the number of entries.

  Next, the controller transmits a file list command frame in step 4 and receives a response frame from the camera / storage / subunit in step 5. The controller analyzes the values of the start number field, end of list bit, and entry number field in the response frame, respectively, and determines the subsequent operation.

  First, at step 6, the end of list bit is checked. When the value of the end-of-list bit is “0”, since the directory entry has not reached the end as described above, the process proceeds to the next step step 7 in order to obtain more directory entries. In step step 7, the value of the start number field and the value of the number of entries field in the response frame are added to generate a new start number value.

  In the next step step 8, the value of the entry number field extracted from the response frame is input to the entry number field in the command frame. As described above, the value of the entry number field in the response frame is guaranteed to be equal to or less than the value of the entry number field in the corresponding command frame, and in step step 3 above, the number of entries field in the command frame is guaranteed. Since a sufficiently large value is input to the value of, there is a high probability that the value input in the entry number field in step step 8 is the maximum number of entries that can be returned in the response frame.

Steps 4 to 8 form a loop, and steps 4 to 8 are executed until all directory entries are acquired. On the other hand, when the value of the end-of-list bit is “1” in step 6, the directory entry has reached the end, so the process proceeds to step 9 and the directory entry acquisition operation is terminated.
With the above-described paging operation, the controller can efficiently acquire a directory entry for the focused directory.

Referring back to FIG. 18, the tenth and eleventh operands (operand [10] and operand [11]) are reserved fields, and any value set in the field can be stored in the camera storage subunit. It will be ignored. For example, the controller sets a value of “FF ₁₆ ” in the field and transmits a command frame.

  The twelfth operand (operand [12]) is a request path length (request_path_length) field, and indicates the byte length of the subsequent request path (request_path) field. The thirteenth operand (operand [13]) and thereafter are variable-length request path fields, which specify a desired directory or file path name. The request path length and the request path correspond to the above-described file path length and file path, respectively.

  In a response frame as a response to the above-described file list command frame, a file list (file_list) field is set in the above-described request path field area. The file list field is a variable-length field and holds the directory entry described above. The file list field can include a plurality of directory entries, and the number of directory entries included in the file list field is indicated by the entry number field in the response frame described above. Also, as shown in FIG. 3, the size of each directory entry is 20 bytes.

FIG. 22 is a diagram showing a format of a media information command (MEDIA INFO control command) frame. The media information command is used to acquire information on a recording medium in the camera storage subunit.
In the media information command frame, the first 6-byte field is the above-described common frame header, and a fixed value “FF ₁₆ ” is designated in the physical volume number field, logical volume number field, and media count field.

FIG. 23 is a diagram showing the format of a response frame for the media information command frame, and the first 6-byte field is a response portion for the common frame header.
The fifth operand (operand [5]) is a physical volume number (number_of_physical_volume) field, and the number of recording media in the camera storage subunit, that is, the number of physical volumes is input. Even when the recording medium is detachable and no recording medium is inserted, the recording medium is added to the number of physical volumes.

After the sixth operand (operand [6]) is a logical volume number (number_of_logical_volume) field, and the number of logical volumes for each physical volume is input. The total number of logical volume fields differs depending on the value of the physical volume field. When the physical volume field is n (n is a natural number), the 0th logical volume field (number_of_logical_volume [0] ) To (n−1) th volume number field (number_of_logical_volume [n−1]), there are n logical volume number fields. When the recording medium is detachable and no recording medium is inserted, a value of “00 ₁₆ ” is input to the logical volume number field associated with the recording medium.

  FIG. 24 is a diagram illustrating a format of a file reception command (RECEIVE FILE control command) frame. The file reception command is used to record a file received from a subunit destination plug on a recording medium in the camera storage subunit.

In the file reception command frame, the first 6-byte field is the common frame header described above, and the volume of the received file to be recorded is specified in the physical volume number field and the logical volume number field. The controller can set the value of “FF ₁₆ ” (“any available volume”) in this field to record files to any recordable physical and logical volume selected by the camera storage subunit. it can. Then, the camera storage subunit sets the physical volume number and the logical volume number selected at the time of recording in the physical volume number field and the logical volume number field, respectively, and returns a response frame.

If the controller sets a value of “FF ₁₆ ” in the physical volume number field of the command frame, the camera storage sub-unit ignores the media count field in the command frame and selects the selected physical volume. Returns a response frame with the media count value set in the media count field.

Four bytes of the fifth to eighth operands (operand [5] to operand [8]) are a reception size (receive_size) field, and designate the number of bytes of a file to be recorded. If the controller cannot determine the number of bytes of the file to record in advance, the controller sets the value of zero (“00 00 00 00 ₁₆ ”) in the receive size field and records the file in the camera storage subunit. Can be made.

  The ninth operand (operand [9]) is a destination plug (destination_plug) field, and designates a subunit / destination plug for inputting file data. In general, prior to issuing a file reception command frame, the controller and the subunit / destination plug of the camera / storage / subunit and the unit plug (unit plug) or the subunit / subunit of another subunit within the same unit Establish a connection with the source plug.

Here, if the subunit / destination plug specified by the controller in the destination plug field has already been used, the camera / storage / subunit will return “busy” (“80 ₁₆ ”) as the result code. Returns a “REJECTED” response frame with the value entered in the first operand.

  The tenth operand (operand [10]) is a reception mode (receive_mode) field, and a file having the same file path name as the file path name specified in the file path field after the thirteenth operand (operand [13]). Specifies what happens when an already exists. An example of encoding of the reception mode field is shown in FIG.

  The eleventh operand (operand [11]) is a file type field that specifies the type of the received file. An example of encoding of the file type field is shown in FIG.

  In the response frame as a response to the file reception command frame, for example, the same value as the command frame is input and returned in the reception size field, the destination plug field, the reception mode field, and the file type field.

  The twelfth operand (operand [12]) is a file path length field, and the thirteenth and subsequent operands are variable length file path fields, which correspond to the file path length and file path described above. The file path name of the result recorded as described above is set in the file path field and is returned to the controller by a response frame. When a “REJECTED” response frame is returned for the file reception command frame, a zero value is set in the file path field.

FIG. 27 is a diagram showing a format of a file transmission command (SEND FILE control command) frame. The file transmission command frame is used as a transmission trigger for file data.
In the file transmission command frame, the first 6-byte area is the above-described common frame header. A fixed value “FF ₁₆ ” is set for the fifth to eighth operands (operand [5] to operand [8]).

  The ninth operand (operand [9]) is a source plug (source_plug) field, which specifies a subunit / source plug used for transmission of file data. In general, prior to issuing a file transmission command frame, the controller performs a unit / source plug of a camera / storage / subunit and a unit / destination plug of a unit plug or another subunit in the same unit. Establish a connection.

Here, when the camera / storage subunit receives the file transmission command frame, if the subunit / source plug specified in the source plug field of the command frame is already used, the camera / storage / subunit The unit returns a “REJECTED” response frame in which the value “busy” (“80 ₁₆ ”) is input to the first operand as a result code.

If the unit plug connected to the subunit / source plug specified by the file transmission command or the subunit / destination plug of another subunit in the same unit cannot receive the specified file, the camera The storage subunit returns a “REJECTED” response frame in which the value of “invalid file type” (“A6 ₁₆ ”) is input to the first operand as a result code.

  Similar to the file reception command frame described above, the twelfth operand (operand [12]) is a file path length field, and the thirteenth operand (operand [13]) and subsequent are variable length file path fields. Corresponds to path length and file path. The file path name of the result recorded as described above is set in the file path field and is returned to the controller by a response frame. When a “REJECTED” response frame is returned for the file transmission command frame, a zero value is set in the file path field.

  FIG. 28 is a diagram showing the format of a volume information command (VOLUME INFO control command) frame, and FIG. 29 is a diagram showing the format of a response frame for the volume information command frame. The volume information command is used to acquire information on a specified volume.

  In the volume information command frame shown in FIG. 28, the first 6-byte field is the common frame header described above, and the physical volume and logical volume from which information is acquired are displayed in the physical volume number field and the logical volume number field. Specify each.

As the fourth operand (operand [4]), a fixed value “FF ₁₆ ” is set in the volume information command frame, and a media count value is set in the response frame.

The fifth operand (operand [5]) is set to a fixed value “FF ₁₆ ” in the volume information command frame, and is an attributes field in the response frame. In the attribute field, an attribute indicating the state of the designated volume is bit-assigned.

  The format of the attribute field is shown in FIG. In FIG. 30, the 6-bit field from the most significant bit is a reserved bit, and the value specified in this area is ignored by the camera storage subunit. The second bit (“bit1”) from the least significant bit is a write prohibition instruction (write_protected) bit, and is set to “1” when the specified volume is write protected. The least significant bit (“bit0”) is a read-only instruction (read_only_media) bit, and is set to “1” when the designated volume is read-only.

In the volume information command frame, the ninth to sixteenth operands (operand [9] to operand [16]) and the seventeenth to twenty-fourth operands (operand [17] to operand [24]) have a fixed value “FF”. FF FF FF FF FF FF FF ₁₆ ”is set.
In the response frame for the volume information command frame, the ninth to sixteenth operands (operand [9] to operand [16]) are maximum capacity (maximum_capacity) fields, and the maximum capacity of the specified volume is set in bytes. Is done. The 17th to 24th operands (operand [17] to operand [24]) are free capacity (free_space) fields, and the current free capacity of the specified volume is set in bytes.

<File transfer>
Next, a standard communication procedure between the controller and the camera storage subunit will be described. FIG. 31 is a diagram showing an overview of a command issuance procedure between the controller and the camera storage subunit.

  First, the controller issues a media information command to the camera storage subunit to obtain information on the number of recording media volumes that the camera storage subunit has (S11). The controller selects one volume after obtaining the information on the number of volumes by the media information command.

  The controller issues a volume information command before accessing the selected volume, and acquires the current media count value from the camera storage subunit (S12). The value acquired by the volume information command is set in the media count field when the command frame of each command for accessing the volume selected by the controller is issued.

  Thereafter, the controller issues a file list command to acquire a file list from the camera / storage / subunit (S13). After acquiring the file list, the controller issues a file transmission command or a file reception command to start file transfer between the controller and the camera / storage subunit (S14).

Next, a file (data) transfer procedure from the camera storage subunit will be described. The controller that has acquired the file list by the communication procedure shown in FIG. 31 issues a file transmission command to make a data transmission request.
At this time, prior to the issuance of the file transmission command, the controller, for example, the above-described asynchronous device between the subunit / source plug of the camera / storage / subunit and the destination (receiving side) device. Connection is established by connection (Asynchronous Connection). The destination may be a controller or another device.

  FIG. 32 is a diagram showing an example of a command flow when transferring a file from the camera storage subunit, and the vertical direction (T-axis direction) shows a conceptual time passage.

  In FIG. 32, for example, a connection is established by an asynchronous connection between the controller and the camera storage subunit (S21). Next, the controller issues a file transmission command to the camera storage subunit (S22), and starts data transfer from the camera storage subunit (S23). In the present embodiment, the controller can issue a plurality of file transmission commands and generate a plurality of transactions while the connection is established as shown in FIG. 32 (S24, S25). ). When the data transfer ends, the controller disconnects the connection established in step S21 (S26).

  Next, a procedure for causing the camera storage subunit to receive a file will be described. FIG. 33 is a diagram showing an example of a command flow when a file is received by the camera storage sub-unit, and the vertical direction (T-axis direction) shows a conceptual time passage as in FIG. . The controller that has acquired the information on the volume by the communication procedure shown in FIG. 31 issues a file reception command to make a file data reception request.

  At this time, prior to issuing the file reception command, the controller establishes a connection by an asynchronous connection between the subunit / destination plug of the camera / storage / subunit and the source which is the transmission source device. Establish (S31). The source may be a controller or another device. For example, in FIG. 33, a connection is established using the controller as a source.

  Next, the controller issues a file reception command to the camera storage subunit (S32), and causes the camera storage subunit to start receiving file data (S33). As shown in FIG. 33, while the connection is established, the controller can issue a plurality of file reception commands to receive a plurality of files (S34, S35). When the file data transfer ends, the controller disconnects the connection established in step S31 (S36).

  In the file transfer procedure described above, a connection has been established, but file data has been sent / received even though a command that triggers file transfer from the controller, for example, a file transmission command or a file reception command has not been issued. In this case, the camera storage subunit discards the file data.

As described above, the connection between the producer node (hereinafter referred to as “producer”) that is the data transmission side and the consumer node (hereinafter referred to as “consumer”) that is the data reception side is managed. When a controller node (hereinafter referred to as “controller”) controls a producer and a consumer, the controller issues a command according to the following procedure.
1) The controller issues a command to establish a connection to consumers and producers.
2) The controller issues a trigger command (for example, a file reception command) to the consumer.
3) After receiving the response from the consumer, the controller issues a trigger command (for example, a file transmission command) to the producer.

<Asynchronous Connection>
As described above, in the file system according to the present embodiment, file data transfer and file attribute data transfer are performed by an asynchronous connection. As shown in FIG. 34, for example, a communication system that transmits and receives data through an asynchronous connection includes a producer 3401 that is a data transmission side, a consumer 3402 that is a data reception side, and a controller 3403 that manages the connection between the producer and the consumer. Composed. In FIG. 34, the producer 3401, the consumer 3402, and the controller 3403 are shown as different nodes, but the producer 3401 may have the function of the controller 3403 without providing the controller 3403. 3402 may have the function of the controller 3403.

  The producer 3401 and the consumer 3402 each have an asynchronous plug register for transmitting and receiving data. The asynchronous plug register is configured as shown in FIG. 35, and includes one asynchronous input port register (iAPR) and a plurality of asynchronous output port registers (oAPR) (FIG. 35). In the example shown in FIG. 5, the first to fourteenth asynchronous output port registers (oAPR [1] to oAPR [14]) are configured. One asynchronous input port register and a plurality of asynchronous output port registers are respectively assigned to the address space of the IEEE1394 interface.

  Here, a node having only a function as a producer includes only an asynchronous output port register, and a node having only a function as a consumer includes an asynchronous input port register and a segment buffer for receiving data. A node having both functions of a producer and a consumer includes an asynchronous input port register, an asynchronous output port register, and a segment buffer.

  Here, when a producer can transmit data to a plurality of consumers with one connection, the producer has a plurality of asynchronous output port registers according to the data transmission capability, and the data is transmitted to only one consumer. If transmission is not possible, it is sufficient to provide only one asynchronous output port register.

  A node capable of simultaneously forming a plurality of connections includes a plurality of asynchronous plug registers shown in FIG. Thus, some nodes may have a plurality of asynchronous plugs, and each asynchronous plug is identified by a plug ID (plug_id).

  For example, it is assumed that the producer 3401 writes image data or the like in a segment buffer included in the consumer 3402 by a write transaction. At this time, the data to be written is called a frame, and when the size of the frame is larger than the size of the segment buffer, the writing is performed in a plurality of sessions. Data written in one session is called a segment.

  The controller 3403 transmits information such as the node ID of the consumer 3402, the plug address of the consumer 3402 used for the connection, and the plug number to the producer 3401. Similarly, the controller 3403 transmits information such as the node ID of the producer 3401, the plug address of the producer 3401 used for the connection, and the plug number to the consumer 3402. The producer 3401 and the consumer 3402 that have received the information from the controller 3403 start data communication based on the received information, and the data is transmitted from the producer 3401 to the consumer 3402.

  The communication from the controller 3403 to the producer 3401 or the consumer 3402 and the data communication between the producer 3401 and the consumer 3402 are performed using an asynchronous transaction. The packet format used for this asynchronous transaction is the same as the data structure shown in FIG.

  The format of the command frame used for the asynchronous connection is configured as shown in FIG. 36, for example. Note that the command frame transmitted from the controller 3403 to the producer 3401 or the consumer 3402 and the response frame transmitted from the producer 3401 or the consumer 3402 to the controller 3403 have the same format.

An opcode 3601 indicates the type of command, and a code value “26 ₁₆ ” indicating that it is a command frame of an asynchronous connection is set.
The subfunction field 3602 designates an operation (such as securing a plug resource, setting / releasing a connection) performed by a producer or a consumer according to the command. FIG. 37 shows the encoding of the subfunction field.

In the following description, an asynchronous connection command (ASYNCHRONOUS CONNECTION control command) frame is called based on a subfunction field. For example, when the value of the sub-function field of the asynchronous connection command frame is “E1 ₁₆ ” (EX_ALLOCATE), it is referred to as an “EX_ALLOCATE” command frame.

  The status field 3603 is a field that represents the status of the command execution result. Data is set in the response frame, and the status is notified to the controller.

A plug ID (plug_id) field 3604 designates a plug number used for connection. An example of the encoding of the plug ID field is shown in FIG. In FIG. 38, the value “BF ₁₆ ” is special, and the controller establishes a connection using a plug ID that is not currently used for a device that supports an asynchronous connection such as a camera, storage, or subunit. Used to direct.

  The plug offset (plug_offset) field 3605 is a 42-bit field, and the head address of the plug (address corresponding to the asynchronous input port register shown in FIG. 35) is set.

A port ID (port_id) field 3606 indicates which port in the plug is selected. An example of encoding of the port ID field is shown in FIG. In FIG. 39, the consumer port (Consumer Port [0]) corresponds to the asynchronous input port register (iAPR) shown in FIG. 35, and the first to fourteenth production supports (Producer Port [1] to Producer Port [14] ]) Correspond to the first to fourteenth asynchronous output ports (oAPR [1] to oAPR [14]) shown in FIG. Also, the value “0F ₁₆ ” is special, so that the controller establishes a connection with a production support that is not currently used for devices that support asynchronous connections, such as cameras, storages, and subunits. Used to indicate.

Therefore, the offset address of the port register used for the connection is calculated by the following equation (1), for example.
(Offset address) = (plug_offset) << 6 | (port_id) << 2 (1)
Here, in the above formula (1), “<<” indicates a left bit shift operation, and “|” indicates a bitwise logical OR operation (the same applies to the following).

A port bits (port_bits) field 3607 indicates the capability of the selected port. An example of the encoding of the port bit field is shown in FIG. In FIG. 40, “X” indicates a bit (Don't Care) that is not considered.
A connected node ID (connected_node_id) field 3608 indicates a partner node (hereinafter referred to as “connected node”) for setting a connection. The controller sets the node ID of the connected producer to the consumer and notifies it with a command frame, and sets the node ID of the connected consumer to the producer and notifies it with a command frame.

A connected plug offset (connected_plug_offset) field 3609 indicates an address of a plug included in the connection node.
A connection port ID (connected_port_ID) field 3610 indicates a port number of a connection node used for connection.

Therefore, the offset address of the port register of the connection node is calculated by the following equation (2).
(Offset address)
= (Connected_plug_offset) << 6 | (connected_port_id) << 2 (2)

The connected port bits (connected_port_bits) field 3611 indicates the port capability of the connection node.
A connected plug ID (connected_plug_id) field 3612 indicates the plug number of the connection node used for the connection.

  The exclusive control (ex: exclusive) bit 3613 is a bit that specifies that the controller excludes other controllers with respect to control of both the internal connection and the connection from the unit to the other unit.

  Specifically, the target node that received the asynchronous connection command frame in which the exclusive control bit 3613 is set to “1” (the node that receives the command frame from the controller) is issued thereafter, and the received asynchronous connection command frame is received. And whether the node ID of the controller that issued the received asynchronous connection command frame matches the node ID of the controller that issued the asynchronous connection command frame with the exclusive control bit 3613 set to “1” is detected. To do. As a result, if the node IDs do not match, the target node returns a “REJECTED” response frame in response to the received command frame.

Also, the asynchronous connection command frame in which the exclusive control bit 3613 is set to “1” is accepted by the target node in the following case.
-When the specified plug is a consumer plug-When the specified producer plug is not used In the above case, the target node "ACCEPTED" to the controller that issued the asynchronous connection command frame. Returns a response frame.

A connection count (connection_count) field 3614 indicates how many producer supports the consumer's port is connected to.
A write interval (write_interval) field 3615 indicates a minimum transaction interval when the producer performs a write transaction on the segment buffer of the consumer.

A retry count (retry_count) field 3616 indicates the value of the number of retries (reexecution) required when the serial bus transaction fails. The value of the retry count field is set in the response frame from the consumer.
A subunit type (subunit_type) field 3617 and a subunit ID (subunit_id) field 3618 specify a subunit to be a source or a destination. The definitions of the subunit type field 3617 and the subunit ID field 3618 are the same as those of the subunit address described above.
A subunit plug (subunit_plug) field 3619 designates a subunit plug number which is an input / output plug for exchanging data.

Next, a connection establishment procedure in the above-described asynchronous connection will be described. FIG. 41 is a diagram showing a connection establishment procedure in the asynchronous connection.
In FIG. 41, 4100 is a producer, 4101 is a first subunit of the producer 4100, 4102 is a source plug, 4103 is a producer support, 4110 is a controller, 4120 is a consumer, 4121 is a consumer 4120 is a second subunit, Reference numeral 4122 denotes a destination plug, and 4123 denotes a consumer port.

  As shown in FIG. 41, in the present embodiment, the controller 4110 first issues an “EX_ALLOCATE” command (EX_ALLOCATE control command) frame to the consumer 4120 (1a). At this time, in the example shown in FIG. 41, the internal connection between the destination plug 4122 and the consumer port 4123 of the second subunit 4121 in the consumer 4120 is established.

  The internal connection between the destination plug 4122 and the consumer port 4123 is from the first “EX_ALLOCATE” command frame to the time when an “EX_ATTACH” command (EX_ATTACH control command) frame, which will be described later, is issued. Is locked exclusively to prevent changes.

  As shown in FIG. 37 above, the “EX_ALLOCATE” command frame includes a consumer port acquisition request, a subunit / destination plug acquisition request, and a connection between the consumer port and the subunit / destination plug in an asynchronous connection. Make a request. The consumer 4120 returns the subunit plug ID and the address of the consumer port to the controller 4110 as an “EX_ALLOCATE” response frame for the “EX_ALLOCATE” command frame (1b).

  Next, the controller 4110 issues an “EX_ALLOCATE_ATTACH” command (EX_ALLOCATE_ATTACH control command) frame to the producer 4100 (2a), a subunit / source plug acquisition request, a producer support acquisition request, and a subunit / source plug. And connection request with producer support.

  As a result, an internal connection between the source plug 4102 and the producer support 4103 of the first subunit 4101 in the producer 4100 is established. The producer 4100 returns an “EX_ALLOCATE_ATTACH” response frame to the “EX_ALLOCATE_ATTACH” command frame to the controller 4110 (2b).

  Further, the controller 4110 issues an “EX_ATTACH” command (EX_ATTACH control command) frame to the consumer 4120 (3a), and makes a connection request between the production support 4103 and the consumer port 4123. The consumer 4120 returns an “EX_ATTACH” response frame to the “EX_ATTACH” command frame to the controller 4110 (3b).

  The consumer 4120 updates the asynchronous output port register in the producer 4100 to indicate that the preparation for reception has been completed (4). Note that the producer support 4103 remains in an inactive state (inactive state) until the consumer 4120 updates the asynchronous output port register in the producer 4100.

  By operating according to the connection establishment procedure as described above, an asynchronous connection is established between the first subunit 4101 and the second subunit 4121 in this embodiment.

  Next, a connection disconnection procedure in the above-described asynchronous connection will be described. FIG. 42 is a diagram showing a connection disconnection procedure in the asynchronous connection. In FIG. 42, blocks having the same functions as those shown in FIG. 41 are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 42, first, the controller 4110 issues an “EX_DETACH” command (EX_DETACH control command) frame to the consumer 4120 (1a ′), and the connection disconnection procedure is started. The “EX_DETACH” command frame decreases the connection count value.

  When the connection count value notified in the “EX_DETACH” response frame (1b ′) returned to the controller 4110 by the consumer 4120 as a response to the “EX_DETACH” command frame is zero, the consumer 4120 goes through the connection disconnection procedure without delay. Indicates that it has entered.

  On the other hand, when the connection count value notified in the “EX_DETACH” response frame is not zero, it indicates that the consumer 4120 still has at least one connection. When the connection count value is not zero, the controller 4110 does not issue an “EX_DETACH_RELEASE” command (EX_DETACH_RELEASE control command) frame described later.

  As described above, when the connection count value notified in the “EX_DETACH” response frame is zero, the destination plug 4122 and the consumer port 4123 of the second subunit 4121 in the consumer 4120 are in an inactive state. It remains. In this inactive state, the consumer port 4123 accepts register update from the producer 4100 and writing to the segment buffer.

  Next, the controller 4110 issues an “EX_DETACH_RELEASE” command frame to the producer 4100 (2a ′), and the connection between the source plug 4102 and the producer support 4103 of the first subunit 4101 in the producer 4100 is disconnected. The Further, the producer 4100 returns an “EX_DETACH_RELEASE” response frame to the “EX_DETACH_RELEASE” command frame to the controller 4110 (2b ′).

  Finally, the controller 4110 issues an “EX_RELEASE” command (EX_RELEASE control command) frame to the consumer 4120 (3a ′), and the internal connection in the consumer 4120 is disconnected. The consumer 4120 returns an “EX_RELEASE” response frame to the “EX_RELEASE” command frame to the controller 4110 (3b ′).

  By operating according to the disconnection procedure as described above, in this embodiment, the asynchronous connection between the first subunit 4101 and the second subunit 4121 is disconnected.

  As described above, according to the present embodiment, in addition to the existing command for establishing the connection by the asynchronous connection, the subunit plug (subunit / source plug, subunit destination) in the unit (producer or consumer) is also provided. Expand the field for specifying the (Nation plug). As a result, asynchronous connections between units, and connections between subunit plugs within the units and the ports provided in the units can be connected or disconnected simultaneously with a single command. It is possible to realize a communication system capable of performing reliable data transfer and ensuring the reliability of data transfer.

  In addition, by providing an exclusive control bit in the asynchronous connection, other controllers are excluded for controlling both the connection within the unit and the connection from the unit to another unit according to the value of the exclusive control bit. Therefore, exclusive control can be performed efficiently.

In the above-described asynchronous connection command, the same opcode value (“26 ₁₆ ”) as that of the AV / C Commands for Management of Asynchronous Serial Bus Connection standard is used, but any other value may be used.

[Other Embodiments]
The present invention can be applied to an apparatus including a single device, and can also be applied to a system including a plurality of devices such as a host computer, an interface device, a reader, and a printer.
Also, a software program for realizing the functions of the above-described embodiment for a computer in an apparatus or a system connected to the various devices so that the various devices are operated to realize the functions of the above-described embodiments. What was implemented by supplying the code and operating the various devices according to a program stored in the computer (CPU or MPU) of the system or apparatus is also included in the scope of the present invention.

  In this case, the program code of the software itself realizes the functions of the above-described embodiments, and the program code itself and means for supplying the program code to the computer, for example, the program code is stored. The recording medium constitutes the present invention. As a recording medium for storing the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM (program ROM, EPROM, EEPROM, etc.), etc. are used. Can do.

  Further, by executing the program code supplied by the computer, not only the functions of the above-described embodiments are realized, but also the OS (operating system) or other application software in which the program code is running on the computer, etc. It goes without saying that the program code is also included in the embodiment of the present invention even when the functions of the above-described embodiment are realized in cooperation with the embodiment.

  Further, after the supplied program code is stored in the memory provided in the function expansion board of the computer or the function expansion unit connected to the computer, the CPU provided in the function expansion board or function expansion unit based on the instruction of the program code Needless to say, the present invention includes a case where the functions of the above-described embodiment are realized by performing part or all of the actual processing.

It is a block diagram which shows one structural example of the communication system by embodiment of this invention. It is a figure which shows the structural example of a file system. It is a figure which shows an example of the data structure of a directory entry. It is a figure which shows the structure of an attribute field. It is a conceptual diagram for demonstrating FCP. It is a figure which shows the data structure of an asynchronous packet. It is a figure which shows the destination offset address of a command register and a response register. It is a figure which shows the data structure of a FCP frame. It is a figure which shows an example of the encoding of a CTS field. It is a figure which shows the data structure of a command frame and a response frame. It is a figure which shows an example of the relationship between the value of a command type field, and a command type. It is a figure which shows an example of the relationship between the value of a subunit type field, and the type of subunit. It is a figure which shows an example of the relationship between the value of a response field, and a response type. It is a figure which shows an example of the relationship between the command of a camera storage subunit, and the opcode value of a camera storage subunit. It is a figure which shows the format of a common frame header. It is a figure which shows the relationship between the operation mode of a control command, and a subfunction field value. It is a figure which shows an example of encoding of a result code. It is a figure which shows the format of a file list command frame. It is a figure which shows the definition of a file type field value. It is a figure which shows the definition of an attribute field. It is a flowchart which shows paging operation | movement. It is a figure which shows the format of a media information command frame. It is a figure which shows the format of the response frame with respect to a media information command frame. It is a figure which shows the format of a file reception command frame. It is a figure which shows an example of an encoding of a reception mode field. It is a figure which shows an example of encoding of a file type field. It is a figure which shows the format of a file transmission command frame. It is a figure which shows the format of a volume information command frame. It is a figure which shows the format of the response frame with respect to a volume information command frame. It is a figure which shows the format of an attribute field. It is a figure which shows the outline | summary of the issuing procedure of the command between a controller and a camera storage subunit. It is a figure which shows an example of the command flow at the time of transferring a file from a camera storage subunit. It is a figure which shows an example of the command flow at the time of making a camera storage subunit receive a file. It is a figure which shows the structural example of the communication system which transmits / receives data by an asynchronous connection. It is a figure which shows the structural example of an asynchronous plug register. It is a figure which shows the format of the command frame used for an asynchronous connection. It is a figure which shows an example of encoding of a subfunction field. It is a figure which shows an example of encoding of a plug ID field. It is a figure which shows an example of encoding of a port ID field. It is a figure which shows an example of encoding of a port bit field. It is a figure which shows the connection establishment procedure in an asynchronous connection. It is a figure which shows the connection cutting | disconnection procedure in an asynchronous connection.

Explanation of symbols

10 Cable 100 Printer 101, 201 Communication unit 102, 202 Communication auxiliary unit 103, 203 Image processing unit 104, 204 Removable recording unit 105, 205 Display unit 106, 206 Control unit 107, 207 Operation unit 108, 208 Memory 109 Print output Unit 110, 210 Control bus 111, 211 Data bus 200 Electronic still camera 209 Imaging unit

Claims (35)

A communication system in which a transmission node that transmits data and a reception node that receives data transmitted from the transmission node are connected via a serial bus capable of transmitting and receiving serial data,
Comprising control means for outputting arbitrary control data;
The transmission node includes a transmission means for transmitting data via the serial bus;
A function operation means having a predetermined function capable of being controlled by control data from the control means, and having an output means capable of outputting data to the transmission means;
Communication path control means for controlling the connection state between the transmission means and the output means,
The communication data, wherein the control data includes control data for controlling a connection state between the transmission means and the output means that can be transmitted using a single control command.   2. The communication system according to claim 1, wherein the control data includes data for identifying the transmission unit and data for identifying the output unit.   The communication system according to claim 1, wherein the control data further includes data for performing exclusive control by controlling a connection state between the transmission unit and the output unit. The functional operation means is a recording means for recording data,
The communication system according to claim 1, wherein the transmission unit is capable of transmitting data recorded in the recording unit.   The communication system according to claim 4, wherein the recording means records file data and file attribute data. A communication system in which a transmission node that transmits data and a reception node that receives data transmitted from the transmission node are connected via a serial bus capable of transmitting and receiving serial data,
Comprising control means for outputting arbitrary control data;
The receiving node includes receiving means for receiving data via the serial bus;
A function operating unit having an input unit capable of inputting data received by the receiving unit and having a predetermined function that can be controlled by control data from the control unit;
Communication path control means for controlling a connection state between the receiving means and the input means,
The communication system, wherein the control data includes control data for controlling a connection state between the receiving means and the input means that can be transmitted using a single control command.   The communication system according to claim 6, wherein the control data includes data for identifying the receiving means and data for identifying the input means.   8. The communication system according to claim 6, wherein the control data further includes data for performing exclusive control by controlling a connection state between the receiving unit and the input unit.   9. The serial bus according to claim 1, wherein the serial bus is a serial bus conforming to the IEEE 1394 standard, and data transmission / reception between the transmission node and the reception node is performed by asynchronous transfer. The communication system according to item. A communication system in which a control node that transmits arbitrary control data, a transmission node that receives the control data, and a reception node are connected via a serial bus for transmitting and receiving serial data,
The transmission node is controllable by a part of the control data, and has n (n is a natural number) function operation means each having a predetermined function each having an output means for outputting data,
Transmission means for transmitting data by asynchronous transfer via the serial bus,
The receiving node comprises receiving means for receiving the data by asynchronous transfer via the serial bus;
The control node transmits the control data including data for securing a data transmission path between the output unit and the transmission unit to the transmission node by a single data transmission. .   The said control node transmits the said control data containing the data for performing the exclusive control regarding the ensuring of the data transmission path between the said output means and the said transmission means to the said transmission node, It is characterized by the above-mentioned. The communication system described. A communication system in which a control node that transmits arbitrary control data, a transmission node that receives the control data, and a reception node are connected via a serial bus for transmitting and receiving serial data,
The transmission node includes transmission means for transmitting data by asynchronous transfer via the serial bus,
The receiving node is controllable by a part of the control data and has m (m is a natural number) functional operation means having a predetermined function each having an input means for inputting data;
Receiving means for receiving the data by asynchronous transfer via the serial bus,
The control node transmits the control data including data for securing a data reception path between the input unit and the reception unit to the reception node by a single data transmission. .   13. The control node according to claim 12, wherein the control node transmits the control data including data for performing exclusive control related to securing a data reception path between the input unit and the reception unit to the reception node. The communication system described. A communication system in which a control node that transmits arbitrary control data, a transmission node that receives the control data, and a reception node are connected via a serial bus for transmitting and receiving serial data,
The transmission node includes a recording means for recording data;
Transmission means for transmitting the data recorded in the recording means by asynchronous transfer via the serial bus,
The receiving node comprises receiving means for receiving data transmitted from the transmitting node,
The communication system, wherein the control data includes control data for performing a logical connection between the recording means and the transmission means by a single data transmission.   15. The communication system according to claim 14, wherein the recording unit records file data and file attribute data.   16. The communication system according to claim 14, wherein the control data includes control data for performing exclusive control by connection control between the recording unit, the transmission unit, and the reception node. A communication system in which a control node that transmits arbitrary control data, a transmission node that receives the control data, and a reception node are connected via a serial bus for transmitting and receiving serial data,
The transmission node includes a file system, and provides the file system to the reception node by asynchronous transfer via the serial bus.
The communication system, wherein the control data includes control data for logical connection with the file system by a single data transmission.   The communication system according to claim 17, wherein the control data includes control data for performing exclusive control in connection control between the file system and the receiving node.   The communication system according to any one of claims 10 to 18, wherein the control node and the receiving node are the same node. A terminal device connected to a receiving node for receiving data via a serial bus capable of transmitting and receiving serial data,
A transmission means for transmitting data via the serial bus;
A function operating means having an output means capable of outputting data to the transmission means and having a predetermined function which can be controlled based on the control data;
A terminal device comprising: a communication path control unit capable of controlling a connection state between the transmission unit and the output unit based on control data transmitted using a single control command.   21. The control data transmitted using the single control command includes data for performing exclusive control by controlling a connection state between the transmission unit and the output unit. Terminal equipment. A terminal device connected to a transmission node that transmits data via a serial bus capable of transmitting and receiving serial data,
Receiving means for receiving data via the serial bus;
A function operating means having an input means capable of inputting data received by the receiving means and having a predetermined function that can be controlled based on the control data;
A terminal device comprising: a communication path control unit capable of controlling a connection state between the receiving unit and the input unit based on control data transmitted using a single control command.   23. The control data transmitted using the single control command includes data for performing exclusive control by controlling a connection state between the receiving unit and the input unit. Terminal equipment. A control method of a communication system in which a transmission node that transmits data and a reception node that receives data transmitted from the transmission node are connected via a serial bus capable of transmitting and receiving serial data,
The connection state of the output means for outputting data from the functional operation means having a predetermined function provided in the transmission node and the transmission means for transmitting the data to the outside via the serial bus is a single state. A control method for a communication system, characterized in that control is performed based on control data transmitted using a control command.   25. The communication system according to claim 24, wherein exclusive control is performed based on control data transmitted using the single control command in controlling the connection state between the transmission unit and the output unit. Control method. A control method of a communication system in which a transmission node that transmits data and a reception node that receives data transmitted from the transmission node are connected via a serial bus capable of transmitting and receiving serial data,
The connection state between the input means for inputting data to the function operation means having a predetermined function and the reception means for receiving data from the outside via the serial bus is provided in the reception node. A control method for a communication system, characterized in that control is performed based on control data transmitted using a control command.   27. The communication system according to claim 26, wherein exclusive control is performed based on control data transmitted using the single control command in controlling the connection state between the receiving unit and the input unit. Control method.   Output means for outputting data from a functional operation means having a predetermined function, provided in a transmission node connected to a reception node that receives data via a serial bus capable of transmitting and receiving serial data, and via the serial bus A program for causing a computer to execute control of a connection state with a transmission means for transmitting data to the outside based on control data transmitted using a single control command.   29. The program according to claim 28, further causing a computer to execute exclusive control of a connection state between the transmission unit and the output unit based on control data transmitted using the single control command.   A receiving node connected to a transmitting node that transmits data via a serial bus capable of transmitting and receiving serial data, an input means for inputting data to a functional operation means having a predetermined function, and via the serial bus A program for causing a computer to execute control of a connection state with a receiving means for receiving data from the outside based on control data transmitted using a single control command.   31. The program according to claim 30, which causes a computer to execute exclusive control of a connection state between the receiving unit and the input unit based on control data transmitted using the single control command.   Output means for outputting data from a functional operation means having a predetermined function, provided in a transmission node connected to a reception node that receives data via a serial bus capable of transmitting and receiving serial data, and via the serial bus A program for causing a computer to execute control of a connection state with a transmission means for transmitting data to the outside based on control data transmitted using a single control command is recorded. Computer-readable recording medium.   A program for causing a computer to execute exclusive control of a connection state between the transmission unit and the output unit is further recorded based on control data transmitted using the single control command. Item 33. The computer-readable recording medium according to Item 32.   A receiving node connected to a transmitting node that transmits data via a serial bus capable of transmitting and receiving serial data, an input means for inputting data to a functional operation means having a predetermined function, and via the serial bus And recording a program for causing a computer to execute control of a connection state with a receiving means for receiving data from the outside based on control data transmitted using a single control command. Computer-readable recording medium.   A program for causing a computer to execute exclusive control of a connection state between the receiving unit and the input unit is further recorded based on control data transmitted using the single control command. Item 35. The computer-readable recording medium according to Item 34.

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